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HYGIENE 
 
 AND 
 
 PUBLIC HEALTH 
 
 VOL. I. 
 
A TEEATISE 
 
 ON 
 
 HYGIENE MD PUBLIC HEALTH 
 
 EDITED BY 
 
 THOMAS STEVENSON, M.D., F.E.C.P. Lond. 
 
 LECTUBEE ON CHEMISTBY AND ON MEDICAL JUBISPETJDENCE 
 
 AT guy's hospital 
 
 OFFICIAL ANALYST TO THE HOME OFFICE 
 
 AND 
 
 SHIELEY F. MUEPHY 
 
 MEDICAL OFFICER OF HEALTH OF THE ADMINISTEATIVE COUNTY OF LONDON 
 
 VOL. I. 
 
 PHILADELPHIA 
 
 P. BLAKISTON, SON, & CO. 
 
 1012 WALNUT STKEET 
 1892 
 
PEEFACB 
 
 It is now some years since the late Professor De Chaumont proposed to 
 the pubHshers of this work the issue of a treatise on Hygiene and Public 
 Health which should contain essays by various authors especially 
 qualified to discuss the several subjects which come within its scope. 
 
 The wisdom of adopting this course has been increasingly demon- 
 strated as time has given opportunity for knowledge to grow ; for in 
 some degree these subjects have become specialised, and as a result 
 exceptional knowledge and experience of each are required for their 
 proper treatment. 
 
 The Editors, in superintending the preparation of these volumes, 
 have been fortunate in obtaining the co-operation of writers whose 
 names are the best guarantee of the value of their contributions. 
 
 The work has been divided into different sections, each of which 
 is independent of the others ; but, inasmuch as numerous authors 
 have been employed in its elaboration, and one subject is often related 
 to another, it has not always been found possible, without destroying 
 the completeness of an article, to avoid dealing in it with matters also 
 treated by another writer. In a few minor instances the views upon 
 the same subject by different authors have not always been fully in 
 accord. 
 
 It has, however, been thought that it would be better in a work 
 consisting of articles to each of which the author's name is appended, 
 to allow of some freedom in this respect, rather than to endeavour to 
 bring occasionally divergent views into harmony, especially when the 
 data to hand do not afford grounds for complete judgment. 
 
 The several articles consequently do not necessarily represent the 
 views of the Editors ; each author is separately responsible for those 
 he expresses, the work of the Editors being more particularly directed 
 to ensuring a convenient arrangement of the subjects. 
 
 In the selection of subjects the Editors have been mainly guided 
 by the requirements of the Medical Officer of Health at the present 
 time, after a lapse of more than forty years since this office was created. 
 The earliest conceptions of the Medical Officer of Health showed that 
 he was expected to be no mere empiricist. So long ago as the year 
 1848 an instructional minute of the General Board of Health required 
 
vi HYGIENE 
 
 that he should make himself familiar with the natural and acquired 
 featui'es of the place to which he was appointed ; with the levels, inclina- 
 tions, soil, wells, and water springs of the district; with its meteorological 
 peculiarities ; with the distribution of its buildings and open spaces, 
 and of its burial-grounds ; with its drainage ; with its industries ; 
 with the house accommodation of the poorer classes and their oppor- 
 tunities for personal cleanliness ; and with the regulations in force for 
 lodging-houses- and slaughtering-places, for the cleansing of the place, 
 and for the removal of domestic refuse. He was also to obtain infor- 
 mation as to disease prevalence, and as to the extent of its dependence 
 upon removable causes. 
 
 It was held that for the proper performance of his duties he was to 
 be skilled in pathology, because this science implied an exact study of 
 the causes of disease in their relations to the living body. A know- 
 ledge of vital statistics was held to be necessary for the purpose of 
 enabling proper comparison to be made which would give evidence of 
 the effect of various conditions on the population. He was to be skilled 
 in chemistry and the use of the microscope for the purpose of judging 
 of the impurities of air, earth, and food, and his chemistry was to 
 help him in the application of deodorising and disinfecting agents. 
 And natural philosophy was to aid him in its relation to ventilation 
 and atmospheric changes, and with reference also to manufacturing 
 processes alleged to be hurtful to health. 
 
 The experience of the time which has elapsed since this minute was 
 issued bears witness to the wisdom of its authors. The subject-matter 
 which now comes within the province of the Medical Officer of Health 
 is mainly an amplification of that of which the minute gives account. 
 
 With the ' more exact study of the causes of disease ' has grown 
 the science of preventive medicine, of which the basis is a knowledge 
 of the natural history of disease. The investigation of the causes of 
 disease has now for a number of years been prosecuted in the labora- 
 tory as well as in the field by many capable observers both in this 
 country and abroad. 
 
 In this way there has already been established the intimate rela- 
 tion of micro-organisms to communicable maladies, and certainly for 
 each of certain diseases it has been definitely shown that a particulate 
 organism is the cause. Again, it has been learnt that other animals 
 than man may serve as the hosts of these organisms, and hence, in 
 seeking for the source of disease of this sort in the human subject, the 
 inquirer is led to study disease in the lower animals. Man in his 
 domestication of animals, and in his use of their flesh and products 
 as his food, is exposed to invasion by diseases from which they and he 
 alike can suffer. 
 
 Coincident with efforts to become acquainted with the ultimate 
 cause of communicable diseases, the study of the natural history of 
 these maladies has been diligently pursued. Fresh facts have been 
 learnt concerning their beginnings and the methods of their dissemina- 
 
PREFACE vii 
 
 tion, of the effects upon their prevalence of the aggregation of children 
 in schools, of the advantages and disadvantages attendant upon the 
 isolation of persons suffering from them in hospitals, and concerning 
 a variety of other circumstances respecting them which, for the pur- 
 poses of their prevention, it is important should be known. 
 
 The part played by earth, air, and water in connection with disease 
 in man is now better understood, and particularly as a result of the 
 work of the last few years. The general notions that filth pla.yed an 
 active part as a producer of disease are being replaced by a more pre- 
 cise knowledge of the particular maladies that are encouraged thereby, 
 and of the circumstances under which filth can itself conserve and 
 foster the specific entities which are the essential causes of certain of 
 these affections. Moreover, the physical conditions which give oppor- 
 tunity for these influences to exert a destructive power are becoming 
 more accurately determined, and hence the work of the health authority 
 is ripening into the application of definite knowledge for the preserva- 
 tion of the community. 
 
 The ability of populations to protect themselves from preventable 
 disease is necessarily in some degree dependent upon economic con- 
 siderations. Earlier efforts have been inevitably tentative, and as a 
 result there exists a not unnatural desire on the part of representative 
 bodies to postpone taking a costly procedure until the course which may 
 be best adopted is well defined. Nevertheless, as the result of the efforts 
 of more enterprising communities, there is accumulation of valuable 
 experience in reference to such questions as methods of conservancy, 
 water supply, the arrangements of streets and houses, which are ready 
 to be utilised by the Health Ofi&cer in advising the authority he serves. 
 
 Although the lessons learned by the investigator are not always 
 immediately applicable for the day by day administration of the Sanitary 
 Authority, nevertheless they provide a basis for further inquiry by 
 those employed in the public service, and indicate the points which 
 they should observe in their examination of the phenomena which 
 are constantly before them. And beyond all question the results 
 hitherto gained give ample guarantee of the value, and mdeed of the 
 necessity, of the acquisition of knowledge for guiding communities in 
 their control of individual action. 
 
 The coincidence of the enforcement of the public health law and 
 the reduction of the general death-rate, as demonstrated by the valuable 
 records of the statistical department of the State, suffices for the 
 encouragement of sanitary authorities in perseverance in the duties 
 which devolve upon them, and indeed demand from them the removal 
 of conditions which have been found to be in a special sense habitually 
 related to the causation of particular diseases. 
 
 As the public mind has become possessed by the consideration that 
 disease is largely preventable, the claim tends to be more fully recog- 
 nised that the community should possess the right to regulate the 
 action of the individual in the interest of the loublic health. In 
 
viii HYGIENE 
 
 earlier years such a claim was regarded with some distrust and even 
 with dissatisfaction ; at the present time, however, the attitude of the 
 public towards health administration is very different, and successive 
 Parliaments have conferred on sanitary authorities additional powers 
 for the control of .conditions prejudicial to health, even to the extent 
 of placing under exceptional circumstances a limitation on personal 
 liberty. The English Law of Public Health has, moreover, become 
 the basis of colonial and foreign legislation, and is necessarily subject- 
 matter with which the Health Officer must make himself intimately 
 acquainted. 
 
 It has been the desire of the Editors that the several papers which 
 these volumes contain should present for the use of readers a fair 
 account of the knowledge, so far as obtainable, of the subjects of which 
 they treat. These subjects are in the main those which are usually 
 dealt with in similar works, but in the selection of authors it has been 
 thought well not to limit the choice to members of the medical profes- 
 sion. Thus, while air has been treated by the physician, warming and 
 ventilation have been entrusted to the physicist ; again, climate has 
 been discussed by the physician, and meteorology has been allotted to 
 the meteorologist ; and again, the article on the dwelling has been con- 
 tributed by members of the architectural profession, while the surgeon 
 has undertaken the discussion of hospital hygiene. In addition to 
 the subjects heretofore contained in works on Hygiene, it has been 
 thought desirable to give equal prominence to some others which have 
 become now of not less concern to the Health Officer. Systematic 
 Physical Education, which has long been neglected in this country, 
 is now receiving more attention, and the need for its recognition as 
 part of every educational system is generally accepted, and hence a 
 section has been devoted to its discussion. A separate section has 
 also been devoted to the discussion of EngHsh Sanitary Law. The 
 pathology and etiology of infectious diseases have necessarily, in view 
 of the immense advance lately gained in these subjects, appeared to 
 deserve an especial place in a work which gives account of preventable 
 disease. Accordingly, in order to make this section self-contained, 
 and to obviate the necessity of the reader seeking elsewhere explana- 
 tion of the matter he is studying, it has been considered necessary 
 that it should give some account of bacteriology and the methods of 
 examination of micro-organisms. Further, with a view to making the 
 account of this class of malady fairly complete, a section has been 
 added on the Natural History and Prevention of Infectious Diseases. 
 
CONTENTS 
 
 OF 
 
 THE FIEST VOLUME 
 
 AIE . ....... J. Lane Hotter 
 
 WAEMING AND VENTILATION . . . W. N. Shaio . 
 
 METEOROLOGY ' . .G.J. Syinons 
 
 INFLUENCE OF CLIMATE ON HEALTH . C. Theodore Williams 
 
 WATER Thomas Stevenson . 
 
 THE INFLUENCE OF SOIL ON HEALTH . S. Monckton Copevian 
 
 FOOD Sidney H. C. Martin 
 
 THE INSPECTION OF MEAT . . . . E. W. Hope . 
 
 CLOTHING . ■ Geo. Vivian Poore . 
 
 PHYSICAL EDUCATION . . . . . Frederick Treves . 
 
 BATHS ; . . . W. Hale White 
 
 THE DWELLING 
 
 HOSPITAL HYGIENE 
 
 THE DISPOSAL OF REFUSE . 
 
 OFFENSIVE AND NOXIOUS BUSINESSES . Thomas Whiteside Hime 
 
 SLAUGHTER-HOUSES E. W. Hope . 
 
 P. Gordon Smith and Keith] 
 D. Young ... J 
 
 H. G. Hoivse .... 
 
 lorfield and Louis'] 
 ■kes ... J 
 
 W. H. Corfield and Louis' 
 C. Park, 
 
 VAdT. 
 1 
 
 31 
 149 
 
 185 
 223 
 307 
 391 
 493 
 507 
 537 
 615 
 
 r,49 
 
 777 
 805 
 897 
 975 
 
 INDEX 
 
 993 
 
 VOL. I. 
 
PLATES IN VOL. I 
 
 PLATE 
 
 I. LOCAL CIRCULATION OF AIE IN A HOUSE 
 
 . To face ^^ 113 
 
 II. CHAET SHOWING THE AMOUNT OF CAEBONIC ACID AT 
 VAEIOUS DEPTHS IN THE SOIL OF MUNICH AND 
 CALCUTTA. (Lewis and Cunningham) .... 
 
 320 
 
 HI. CHART SHOWING THE RANGE OF ATMOSPHERIC TEM- 
 PERATURE AS COMPARED WITH THE TEMPERATURE 
 OF THE SOIL AT VARIOUS DEPTHS. (Fodoe) . 
 
 322 
 
 IV. MAP OF THE SOUTH-EAST OF ENGLAND (Kent, Surbey,n^ 
 AND Sussex) 
 
 Between pages 
 360 and 361,, 
 
 V. MAP SHOWING THE REGISTRATION DISTRICTS OF f^'^^ ^^ f^^^- 
 KENT, SURREY, AND SUSSEX j 
 
 VI. MICROSCOPIC APPEARANCES OF CHIEF FIBRES USED 
 
 FOR CLOTHING .... . ... To face p. 514 
 
 VII. PLAN OF THE CITY HOSPITAL FOR INFECTIOUS 
 
 DISEASES, NEWCASTLE-ON-TYNE „ 750 
 
 VIII. PLAN SHOWING RELATIVE POSITIONS OF LAIRAGE, 
 SLAUGHTER-HOUSES, COOLING-ROOMS, AND MEAT 
 MARKET ... 
 
 987 
 
 IX. PLAN OF PUBLIC ABATTOIRS AND CATTLE MARKET, 
 SWANSEA 
 
 98& 
 
CONTEIBUTOES 
 
 TO 
 
 THE FIKST VOLUME 
 
 COPEMAN, S. MONCKTON, M.A., M.D. Cantab., D.P.H., Medical Inspector of the Local 
 Government Board. (Soil) 
 
 COEFIELD, W. H., M.A., M.D. Oxon., F.E.C.P., Professor of Hygiene and Public Health, 
 University College, London; Medical Officer of Health, St, George's, Hanover 
 Sgtuire. (The Disposal of Ebjuse) 
 
 HIME, THOS. WHITESIDE, M.A., M.D., late Medical Officer of Health, Bradford. 
 (Offensive and Noxious Businesses) 
 
 HOPE, E. W., M.D., D.Sc, Assistant Medical Officer of Health; Lecturer mi Public 
 Health, University College, Liverpool. (The Inspection of Meat : Slaughtek- 
 
 HOUSES) * 
 
 HOWSE, H. G., M.S. Lond., F.E.C.S., Surgeon to, and Lecturer on Surgery at, Guy's 
 Hospital. (Hospital Hygiene) 
 
 MAETIN, SIDNEY H. C, M.D. Lond., F.E.C.P., Assistant Physician to University 
 College Hospital, London. (Food) 
 
 NOTTEE, J. LANE, M.A., M.D., D.P.H., Professor of Military Hygiene, Army Medical 
 School, Netley. (Aie) 
 
 PAEKES, LOUIS C, M.D. Lond., D.P.H., Assistant Professor of Hygienic and Public 
 Health, University College, London ; Lecturer on Public Health at St. George's 
 Hospital ; Medical Officer of Health for Chelsea. (The Disposal of Eefuse) 
 
 POOEE, GEO. VIVIAN, M.D. Lond., F.E.C.P., Physician to University College Hospital ; 
 Professor of Forensic Medicine and of Clinical Medicine, University College, 
 London. (Clothing) 
 
 SHAW, W. N., M.A., F.E.S., Lecturer on Physics in the University of Cambridge. 
 (Wabming and Ventilation) 
 
 SMITH, P. GOEDON, F.E.I.B.A., Architect to the Local Government Board. (The 
 Dwelling) 
 
xii HYGIENE 
 
 STEVENSON, THOMAS, M.D. Lond., F.B.C.P., Lecturer on Chemistnj and on Medical 
 Jurisprudc7ice at Guy's Hospital ; Official Analyst to the Home Office. (Watek) 
 
 SYMONS, G. J., F.E.S., Secretary of the Royal Meteorological Society. (Meteorology) 
 
 TREVES, FREDERICK, F.R.C.S., Surgeon to, and Lecturer on Surgery at, the London 
 Hospital. (Physical Education) 
 
 WHITE, W. HALE, M.D, Lond., F.R.C.P., Physician to, and Lecturer on Materia 
 Medica at, Gmfs Hospital. (Baths) 
 
 WILLIAMS, C. THEODORE, M.A., M.D. Oxon., F.R.C.P., Physician to the Consumption 
 Hospital, Brompton. (Influence of Climate on Health) 
 
 YOUNG, KEITH, D., F.R.I.B.A., Architect to the Middlesex ami London Fever Hospitals. 
 (The Dwelling) 
 
AIE 
 
 BY 
 
 J. LA.NE NOTTEE, M.A., M.D. 
 
 PEOFESSOB OF MILITAEY HTGIENE AT THE AEMT MEDICAL SCHOOL, NETLEY 
 
 VOL. I. 
 
AlK 
 
 Air is a mixture of oxygen and nitrogen with minute traces of other gases : 
 in that collected near the surface of the earth, mineral substances are always 
 present, together with a variable amount of dead and living organised 
 matter. 
 
 Statistics prove that impure air is one of the most important of the 
 causes of death which are always present. Density of population favours 
 the spread of organic impurity in the atmosphere, consequent on dirt, over- 
 crowding, and poverty, and this unfortunately is the normal condition of 
 populous and manufacturing towns. The same has been observed with 
 respect to animals, the health of the animals being in direct proportion to 
 the purity of the air they breathe. 
 
 The following is the composition of average air : — 
 
 ComjMsition of Atmospheric Air. 
 
 Oxygen 
 
 Nitrogen 
 
 Carbon dioxide 
 
 Watery vapour 
 
 Ammonia . 
 
 Organic matter, dead or living, 
 
 unorganised . 
 Ozone 
 
 Salts of sodium 
 Other mineral substances . 
 
 . 209-6 per 1000 volumes. 
 . 790-0 
 ■ 0-4 
 
 . varies with temperature. 
 . trace, 
 organised or\ 
 
 variable. 
 
 The gases which make up atmospheric air do not exist in chemical com- 
 bination, but form a mechanical mixture. This is proved by the fact that 
 they are not found in the air in the proportion of their combining weights, nor 
 in any multiple of these, the oxygen being the active agent required in all 
 the processes of oxidation (i.e. combustion) ; the nitrogen a passive agent, 
 taldng no part in the processes of respiration and serving the purpose of 
 an innocuous diluting agent. 
 
 The air we breathe in large open spaces is liable to very little change in 
 the proportion of its chief constituents ; this is due to the diffusion of 
 gases, to the influence of air-currents, and to the reciprocal action of animals 
 and plants upon it, and recent observations have shown only slight differences 
 in its composition in different parts of the earth. 
 
 The amount of oxygen in pure mountain air is 209"8 per 1000 volumes, 
 while in the air of towns ^ it may fall as low as 208'7 ; it is said to be slightly 
 higher in wet weather or immediately after rain than in dry, foggy weather. 
 
 The amount of carbon dioxide in normal air ranges from 0*2 to 0*o per 
 1000 volumes. Schlagintweit states that it slightly increases up to 11,000 
 feet in height and then decreases ; but this is denied by Tronchet,^ who 
 declares that the COg diminishes in amount above 3300 feet. 
 
 * Air and Bain. By R. Angus Smith. 
 
 ^ Arnould, Nouveaux Eliments d'IIygii7ie, p. 
 
 286. 
 
 b2 
 
4 HYGIENE 
 
 Levy gives, as a mean of his observations at Montsouris, 0'208 per lOOQ 
 volumes. In the Dundee experiments Carnelley, Haldane, and Anderson ^ 
 found an average of 0"390 and a range of 0*220 to 0*560, the mean during 
 the day-time being 0-380, and during the night-time 0-410, in open spaces ; 
 in close spaces at night the mean was 0'4:20. In the suburbs the mean was 
 only 0-280, vd\h a range of 0-180 to 0-350, and in the outskirts of Perth a 
 mean of 0-310, with a range of 0-290 to 0-350. 
 
 The amount of watery vapour in air varies with the temperature ; the 
 higher the temperature the more water can be vaporised ; the difference in 
 the amount being often as great as from 1 to 12 grains in a cubic foot of 
 air. It is the most variable constituent of the atmosphere, but forms on an 
 average from 60 to 75 per cent, of the amount necessary for complete 
 saturation. 
 
 Ozone. — The nature and action of ozone are not yet quite understood. It 
 is now generally admitted by chemists to be an allotropic form of oxygen 
 and a compound molecule made up of three molecules (OgO) of oxygen, 
 while antozone is peroxide of hydrogen (Odling). 
 
 There is no satisfactory method of testing for ozone ; the reaction Avith 
 ozone paper is imperfect, but certain results have been recorded which are 
 fairly trustworthy. The ozone reaction is absent in impure air, in the interior 
 of large towns, near decaying substances, and in crowded dwellings ; there 
 is more reaction in the suburbs of towns than in the centre, more on the tops 
 of mountains than in plains, more near the sea shore than on flat inland 
 surfaces. Ozone is a powerful oxidising agent, oxidising substances which 
 oxygen will not attack ; the quantity contained in the atmosphere is very 
 small, probably rarely exceeding, if even reaching, one part in 10,000. 
 
 Ammonia is always present in the air, in minute traces, either free or 
 combined : the proportion present is at its minimum in winter, increases in 
 the spring, and is highest in summer. Plant life derives its nitrogen in 
 part from this source. 
 
 Organic matter, which ought to be considered as an impurity, is hardly 
 ever absent. 
 
 IMPUEITIES IN AIR 
 
 A variety of substances are continually passing from the surface of the 
 earth into the atmosphere in the condition of gases, vapours, and solid par- 
 ticles ; these would accumulate and render the air irrespirable if their effects 
 were not counteracted by the forces of nature which are continually at work 
 in one form or another. Diffusion, dilution by wind, oxidation, and the fall 
 of rain are the chief purifying agents, while the processes going on in the 
 vegetable world diminish the amount of carbon dioxide evolved and keep it 
 within certain limits : gases diffuse and are rapidly diluted and dispersed by 
 winds so as to be rendered innocuous. It is only in the air of enclosed 
 spaces, when the natural processes of purification are arrested, that any great 
 deviation from the normal standard occurs. 
 
 SUSPENDED MATTEES IN THE AIR 
 
 An immense number of substances pass into the air and may be sus- 
 pended in the atmosphere. The nature of the suspended matters depends 
 chiefly on the locality and other varying conditions. Air of elevated sparsely 
 inhabited places is almost free from suspended matters, while in low-lying 
 and thickly populated districts they are very abundant, and Pasteur has 
 ' Philosophical Transactions Royal Society, No. 178 (1887). 
 
AIB 5 
 
 shown the immense difference in this respect between the air of glaciers and 
 that of inhabited regions at a slightly lower level. 
 
 The suspended matters in the externoi air are partly mineral, partly 
 organic. 
 
 The mineral matters consist largely of silica, peroxide of iron, chalk, clay, 
 soot, chloride of sodium, &c. These are most present in the air in dry 
 weather, rain not only preventing such particles being lifted by the wind, but 
 also washing all suspended matters out of the air and so purifying it. 
 
 The organic suspended matters consist principally of grains of pollen, 
 algse, fragments of hair, wood, straw, stable manure, debris of insects, &c. 
 In Southern Europe and Africa diatoms may be seen, but they are seldom 
 found in this country. Ehrenberg gives the microscopic examination of 
 seventy showers : in addition to particles of sand and oxide of iron he dis- 
 covered very many different living forms, chiefly rhizopods, tardigrades, and 
 anguillulse. In larger towns, especially where manufacturing works exist, 
 the air is often loaded with soot and dust of organic origin, which floats in 
 considerable quantities near the surface of the ground. In an analysis of street 
 dust made by Mr. Tichborne ^ in Dublin he showed that the organic matter 
 present varied from 45*2 per cent, in the air of the street to 29*7 per cent, at 
 the top of Nelson's Pillar (134 feet high) ; the organic matter was chiefly 
 finely ground stable manure : it acted as a ferment and reduced nitrate of 
 potassium to nitrite. In de Chaumont's experiments at St. Mary's Hospital, 
 Paddington, and University College Hospital, the suspended matter collected 
 from the external air included the following substances : epidermis of hay, 
 fragments of pine wood, linen and cotton fibre, epithelium from the mucous 
 surfaces, feathers, charred vegetable particles, and mineral matter. When 
 the air is motionless these suspended matters, as a rule, subside, though some 
 are so light as to float in rarefied air, and Tyndall has shown that if burnt a 
 little bluish mist arises from the combustion, indicating that those consumed 
 are, from their destructible nature, of organic origin. 
 
 The presence of bacteria in external air has recently been the subject 
 of close investigation. They flourish whenever they meet with sufficient 
 moisture, nutritive material, and a suitable temperature (above 60° Fahr.) ; 
 they appear to pass into air from colonies lying on the surface of the earth 
 which are broken up and afterwards scattered by wind. Once passing into the 
 air they float about in the atmospheric currents ; a few adhere to the grosser 
 particles of dust and fall in quiescent air, while others are not deposited even 
 in air which is at rest. Their numbers depend on local conditions, as when 
 there is nutriment for a plentiful development on the surface of the earth and 
 where the superficial colonies are broken up ; this is partly the reason that 
 bacteria are not found in high mountains, over desert plains, or on the sea. 
 This is well shown by the following examples given by Miquel : — 
 
 jMicrobes per cubic 
 metre of air 
 High Mountains ..... 1 
 
 Mid-Atlantic Ocean ..... 6 
 
 Hotel Dieu (Paris) ..... 79,000 
 
 It is not known how far bacteria can be carried by wind, but as dust 
 ■can be conveyed to an almost indefinite distance (as shown by the eruption of 
 Krakatoa, which is supposed to have scattered fine dust over the greater por- 
 tion of the globe) it is not unnatural to presume that bacteria also may be 
 carried over considerable areas. Fischer, however, states that he found no 
 :microbes beyond 120 miles from land. 
 
 ' Chemical News, 1871. 
 
6 HYGIENE 
 
 Of the physical conditions of the air which influence the number of 
 bacteria, dry winds and, in towns especially, drought lasting for some time, 
 favour their increase ; during this latter period many varieties of bacteria, 
 and even pathogenic bacteria, pass into the air. The amount of aqueous 
 vapour present also influences the number of bacteria, as the condensation of 
 vapour leads to the sinking of the particles of dust to which the bacteria 
 adhere, while rain washes the air and brings back to the earth the greater 
 number of these organisms. In external air the pathogenic bacteria form 
 only an infinitesimal part compared with the saprophytes, and all recent 
 experience goes to show that the danger from the entrance of pathogenic 
 bacteria fi-om external air into wounds is extremely small, and that this is 
 occasioned far more frequently by other causes. 
 
 Miquel in his experiments found the air of Montsouris to contain on an 
 average (mean of six years' observations) 450 microbes per cubic metre of air, 
 but these were chiefly in the form of spores. In the streets of Paris the 
 average number to a cubic metre of air was 900. 
 
 In the Dundee experiments Carnelley, Haldane, and Anderson found the 
 average number of organisms to be less than one per litre, in the proportion 
 of three bacteria to one mould. 
 
 The present evidence goes to prove that in the open air the dilution of 
 bacteria is so great, and the number of pathogenic bacteria so very small, 
 that no danger is to be apprehended from them unless they originate from 
 local soiTrces of impurity. 
 
 DISEASES PKODTJCED BY IMPUEITIES IN AIE 
 
 For many years attention has been directed to the great amount of 
 respiratory disease caused by dust inhaled into the lungs by those who 
 worked at certain trades, and a large number of facts relating to this sub- 
 ject have been collected : acute pneumonia, bronchitis, and non-tubercular 
 phthisis are produced, the severity of these diseases depending chiefly on. 
 the amount of dust and on its physical conditions with regard to angularity, 
 roughness, or smoothness of its particles. 
 
 The suspended matter in the air may be of animal, vegetable, or mineral 
 origin, but it is the latter chiefly that gives rise to the most severe results, as 
 is seen in the case of miners of all kinds. Dr. Ogle^ has shown the excessive 
 mortality produced among Cornish miners from phthisis and other respi- 
 ratory diseases. The ' comparative mortality figure ' in 1880 — 82 was 1889, 
 that of all males in England and Wales being 1000, and Cornish males 887 ; 
 from phthisis and other respiratory diseases the comparative mortality 
 amongst Cornish miners was 1148, while amongst coal miners generally 
 throughout England and Wales these diseases gave only 328. It would 
 appear that this excessive mortality is due to some condition peculiar to 
 tin mining (which is almost exclusively carried on in Cornwall), where the 
 dust disengaged is more irritant and ventilation less perfect than in other 
 mines. Owing to improvements in the system of ventilation adopted in 
 mines (especially those in South Staffordshire and South Wales) during the 
 last few years, there has been a great decrease in lung affections, although 
 chronic bronchitis, asthmatical breathing, and vicarious emphysema still pre- 
 vail. The workers in lead mines suffer from lead poisoning and bronchitis,. 
 due to inhalation of dust, and at Reeth, in Yorkshire, where one-half the male 
 
 ' Forty-fifth Beport of the Eegistrar-Gencral. 
 
AIB 7 
 
 population work in lead mines, the deatlis from respiratory diseases are 
 double those of the agricultural population. In copper mines the dust of 
 copper ore is credited with producing severe gastric and intestinal irritation, 
 characteristic of copper poisoning. Among this class of workmen there is a 
 peculiar browning of the skin, wasting, dyspnaja, cough, and coloured expec- 
 toration. The manufacture of pottery, in which a large quantity of mineral 
 dust is thrown into the air, is productive of much disease: the clay used con- 
 sists of disintegrated granite mixed with powdered flint, while in some cases 
 felspar is added. The clouds of dust given off in the various processes are ex- 
 ceedingly irritating to the lung structure, even more so than in coal mining ; 
 partial condensation of the lung substance, due to the slow inflammatory 
 action caused by the inhalation of these irritating particles, follows, and 
 produces the condition known as * potter's lung.' Emphysema is common, 
 its general features being that those affected resemble asthmatical subjects ; 
 the disease is frequently complicated with phthisis. 
 
 Steel grinders suffer most severely from the entrance of particles of dust 
 into their lungs, but the further development of the process of wet grinding 
 has of late years somewhat lessened this evil, and improved ventilation by 
 means of fans has also effected a considerable diminution in the numbers 
 • attacked and in the mortality. In the needle trade, which is altogether dry 
 grinding, extraction tubes are attached to each grindstone, and the greater 
 part of the dust is collected and drawn from the workman ; notwithstanding 
 this, lung affections are extremely prevalent, while the mortality from tuber- 
 cular phthisis and scrofula is excessive. 
 
 The inhalation of dust of vegetable origin produces much the same train 
 of symptoms. In the sorting, scutching, and carding of cotton the intro- 
 duction of closed machinery has done much to mitigate the evils arising in 
 the process of manufacture. In the spinning and sizing of cotton much dust 
 is given off. In flax factories a very irritant dust is produced, known among 
 the workers as ' pounce ' ; those exposed to it suffer from severe dyspnoea, 
 paroxysmal in character, and the dust inhaled is exceedingly difficult to get 
 rid of by expectoration ; it produces a whole train of nervous symptoms. 
 Women suffer most severely, as they form the majority of employes in the 
 mills. The dust arising from the manufacture of silk is less irritating ; it 
 is difficult to say whether, apart from other conditions present, the amount 
 of dust is as destructive as in other trades. 
 
 In the manufacture of ' shoddy ' a large quantity of irritant dust escapes 
 from the machines, producing a febrile condition characterised by headache, 
 sickness, difficulty of breathing, cough, and expectoration. Stonecutters 
 suffer severely from the inhalation of stony particles, which set up slow 
 inflammation in the lungs ; those working on hard and flinty stones are most 
 affected. It is said that men cannot continue working at this class of stone for 
 more than eight years, although during the first three or four years they 
 suffer very little from it. The makers of Portland cement inhale a consider- 
 able quantity of finely ground cement, when transferring it into sacks ; it 
 prevents their continuing at the same work for a number of days in succes- 
 sion ; they frequently expectorate little masses of cement. 
 
 Electroplate and Britannia metal workers suffer from the large quantity 
 of dust evolved in the polishing and cleaning with lime, and from minute 
 particles of the metal which become detached. Workers of mother-of-pearl 
 and ivory also suffer to a considerable extent, the fine dust gi^^ing rise to lung 
 irritation, cough, and hsemoptysis. 
 
 The mortality among workers in certain dust-producing trades from 
 phthisis and respiratory disease, as compared with the mortality in England 
 
8 HYGIENE 
 
 and Wales generally, is shown in the following table, deaths from all causes 
 in males being taken as 1000 : — 
 
 Comparative Mortality. 
 
 
 Phthisis. 
 
 Eespiratory Diseases. 
 
 All males (England and Wales) 
 
 . 220 
 
 182 
 
 Earthenware manufacturers . 
 
 . 473 
 
 645 
 
 File makers 
 
 . 433 
 
 350 
 
 Miners, Cornwall 
 
 . 690 
 
 458 
 
 Painters 
 
 . 461 
 
 166 
 
 The makers of matches formerly suffered from necrosis of the lower jaw, 
 if there was any exposed part on which the fumes of phosphorus could act. 
 The substitution of red or amorphous phosphorus has obviated this danger, 
 as this does not vaporise, and is therefore harmless. 
 
 In some trades the fumes of metals as well as particles of metallic dust 
 pass into the air. Plumbers inhale volatilised oxide of lead, which rises 
 during the process of casting, and also from the fumes produced in burning 
 off old paint ; formerly a large mortality followed the grinding of white lead, 
 but since the moist process has been substituted less harm results. 
 
 Brassfounders are subject to bronchitis and asthma, and also ' brass- 
 founder's ague,' which is said to be produced by the fumes of zinc oxide ; the 
 symptoms are febrile, attended with nervous depression, which obhges them 
 to cease work for a few days. Coppersmiths are occasionally affected in the 
 same way, from inhaling the fumes of the partly volatilised metal. In the 
 manufacture of tobacco some dust is given off, which produces for a short time, 
 in those newly employed, at the work, nausea, giddniess, and irritation to the 
 eyes, but they soon become inured to their work. 
 
 Workers in mercury are subject to mercurialism, and formerly salivation 
 and palsy were common, but this has greatly diminished since electricity 
 has rendered gilding with the aid of mercury obsolete, and the manufac- 
 ture of mirrors from nitrate of silver has practically abolished mercurial 
 affections. 
 
 Arsenic in the form of Scheele's or emerald green is the cause of great 
 suffermg to workmen employed in the making of artificial flowers or wall 
 papers, as well as those who occupy rooms so papered. Such persons 
 suffer from painful rashes, sore eyes, sickness of stomach, and generally the 
 symptoms of arsenical poisoning. 
 
 Gas makers frequently suffer from the noxious effluvia given off by the 
 refuse lime used in the making and purifying of gas. 
 
 In addition to inorganic substances and metals there are organised and 
 living bodies which are suspended in the air, such as pollen of flowers, algse, 
 fungi, and bacteria. Hay fever is produced in susceptible persons by the 
 pollen of flowers (especially Anthoxanthum odoraktm) ; the spores of fungi 
 are known to cause diseases of the skin in man, and they may certainly be 
 regarded as the medium by which such diseases as tinea and favus are 
 spread. 
 
 Dr. Salisbury,^ of Newark, Ohio (U.S.A.), has demonstrated his ability to 
 produce a disease indistinguishable from measles by inoculations of the fungi 
 from mouldy straw, but his experiments have not been confirmed. Measles 
 is also said to have been produced by the fungi growing on linseed meal.^ 
 Hallier, of Jena, also favours the view that fungi spores are the cause of 
 specific diseases. That bacteria of various kinds produce disease appears 
 
 * American Journal of Medical Sciences. 
 
 * Dublin Journal of Medical Science, vol. xxxv. 1863, p. 60, 
 
AIB 9 
 
 now to be finally settled and accepted. Many have been cultivated in pure 
 cultures, their life-history studied, and particular species identified, and the 
 disease produced by inoculation. As examples may be mentioned B. 
 anthracis in woolsorter's disease, B. tuberculosis in phthisis, B. leproi in 
 leprosy, and B. Obermeieri in relapsing fever. 
 
 Certain diseases appear to be more associated with impure air than 
 others ; whether the contagia are capable of growth and multiplication in 
 the air is, uncertain, but that they can retain their vitality for a long time 
 there can be no doubt : the poisons of scarlet fever, smallpox, and enteric 
 fever retain their powers of infection for weeks, and are capable of exciting 
 disease in any person susceptible to their influence. The specilic poisons of 
 various diseases differ in the way in which they are destroyed or rendered 
 innocuous by dilution ; the poison of typhus fever is very volatile, rapidly 
 diffuses, and is perhaps oxidised and got rid of by free ventilation ; so that an 
 interval of a few feet gives under such circumstances sufficient protection, 
 while exactly opposite conditions appear to be the case with the poisons of 
 smallpox and scarlet fever. The poisons of cholera and diphtheria also are 
 believed to be borne some distance by wind, and malaria has been known to 
 be conveyed thus for several hundred yards without its infective power being 
 lessened. 
 
 GASEOUS MATTEES IN THE AIE 
 
 Carbon dioxide. — Normal air contains from 3 to 6 parts of carbon dioxide 
 in 10,000 ; the amount increases during the night and diminishes after sunrise : 
 it is less over large tracts of water than over land, and is more abundant 
 in crowded cities than in the open country. The addition of 10 to 15 per 
 cent, of CO2 to air would render it poisonous, although larger quantities are 
 said to have been inhaled without injury. Dr. Taylor states that in mines 
 in Cornwall where the air contains not more than 2 per cent, the miners 
 suffer considerably, but other circumstances than the CO2 have here to be 
 taken into account. In Dr. Angus Smith's experiments one per cent, of this 
 gas in air from which the organic matter of respiration had been elimi- 
 nated produced slowness of the heart's action with quickening of the respira- 
 tions ; it is, however, uncertain what would be the effects produced by 
 breathing continuously an atmosphere containing 1 or 1*5 per cent, of this 
 gas ; when it reaches this amount organic matters and possibly other gases 
 are present and the quantity of oxygen is also lessened. 
 
 Carbon monoxide. — The poisonous action of carbon monoxide renders a 
 very small quantity of this gas dangerous. Experiments tend to show that 
 when it is absorbed by the blood it combines with the hsemoglobin ; it appears 
 to act as a pure narcotic poison. 
 
 The large quantity of CO (as much as 34 per cent.) in ' water gas ' renders 
 its employment dangerous as an illuminant, the gas being inodorous and 
 unirritating ; poisonous effects are produced if it is inhaled. To avoid this 
 risk it has been suggested to ' odorise ' it, and mercaptan and pyridine have 
 been employed for that purpose. 
 
 Boburite, a mixture of dinitrobenzene, chloronitrobenzene, and am- 
 monium nitrate, has been lately used as an explosive in mines. The fumes 
 resulting from the use of this compound give rise to blueness of the lips, 
 headache, some dyspnoea and loss of muscular power, drowsiness, and 
 ■ occasionally vertigo followed by vomiting; carbon monoxide is produced by 
 .its explosion.^ 
 
 ' British Medical Jourjial, June 15, 1889. 
 
10 HYGIENE 
 
 Sichcrlieit explosive causes somewhat similar symptoms, and especially 
 marked cyanosis, in those employed in its manviiaeture. 
 
 Hydroijcn sulphide. — The eii'ects produced by the inhalation of this gas 
 vary according to the degree of its dilution. If present in somewhat large 
 quantities, nausea, headache, irregular action of the heart, and even convulsions 
 follow, but in dilute doses it produces only low febrile symptoms resembling 
 typhoid fever. The bad effects caused by the inhalation of this gas are 
 mostly to be traced to the opening of old drams and cesspits. Dr. Letheby 
 considers one per cent, in the air would be destructive to human life. Hirt has 
 no doubt that the inhalation of small quantities of this gas produces chronic 
 poisoning in those exposed to the fumes. 
 
 Disulpliide of carbon. — The extensive use of carbon disulphide in india- 
 rubber manufactories produces chronic poisoning, due to the vapours given 
 off. The symptoms are headache, giddiness, and excitement of the nervous 
 system, and these may be followed by insanity. The vapour is exceedingly 
 offensive, nauseous, and very inflammable. 
 
 Ht/drocJiIoric acid vapours when inhaled are extremely irritating to the 
 lungs, causing bronchitis, pneumonia, and ulceration of the trachea. This 
 and other acids are used in some of the processes for the making of steel ; 
 unless protected, the eyes also suffer. 
 
 Ammoniacal vapours are given out in some manufactures ; but they have 
 not been noticed to have any injurious effect on the health of operatives, 
 except occasionally producing inflammation of the conjunctiva. 
 
 Organic effluvia. — Effluvia are produced in nearly all the trades in which 
 animal products are concerned, such as in tanning, leather dressing, glue 
 making, soap works, slaughter-houses, gut scraping ; there are also the 
 effluvia arising from stables, cow-sheds, pig-styes, &c. ; although there is no 
 evidence to show that persons actually employed in these trades suffer in 
 health, there is a well-grounded belief that the general health of those living 
 in the immediate neighbourhood is lowered, and that diseases in their case 
 are apt to assume a more severe type. Some of those exposed to these 
 emanations suffer at first from loss of appetite, nausea, vomiting, and 
 diarrhoea, while residents in the vicinity appear more frequently affected than 
 those actually employed in the trade. 
 
 Excessive humidity. — Excessive moisture, which is nearly always asso- 
 ciated with high temperature, is found in weaving sheds and also in certain 
 branches of the silk trade. Steam is injected into the sheds in order ta 
 communicate the necessary amount of humidity without which the warp, 
 which is sized with china clay, could not be woven ; in consequence the 
 weavers work in damp clothes and fill their lungs with moisture ; they are 
 very liable to bronchitis, due to chill on leaving the overheated factory, and 
 lung diseases cause a large mortality among them. Hat makers, who work 
 imder somewhat similar conditions, suffer in the same way. 
 
 Effect of air rendered impure by respiration. — Air rendered impure by 
 respiration may cause heaviness, headache, and nausea, the poisonous agent 
 present being the organic matter : there is also generally a deficiency of 
 oxygen. When the air is rendered very impure it is rapidly fatal, as in the 
 cases of the Black Hole at Calcutta and of the steamer 'Londonderry.' 
 This vessel left Sligo for Liverpool, and stormy weather coming on the captain, 
 forced 200 steerage passengers into their cabin, which measured 18 feet by 
 
 11 feet and 7 feet high. The hatches were battened down and covered with 
 tarpaulin : when the cabin was opened seventy-two persons were found dead 
 and several expiring. Persons whose occupation obliges them to continuously 
 breathe a vitiated atmosphere become pale and anaemic, and suffer from loss- 
 
AIB 11 
 
 of appetite, headache, &c. Such persons are more prone to phtliisis and 
 diseases of the respiratory organs than those whoso occupation admits of 
 their passing their time in well-ventilated rooms or in the open air. Sedentary 
 habits, want of exercise, improper food, added to the influence of impure air, 
 are extremely productive of phthisis ; but it has been clearly shown that 
 breathing air rendered impure by respiration is more potent than any other 
 condition which predisposes to this disease. A good example of this may be 
 found in the army, especially in foreign stations, where an increase of the 
 cubic space allowed to each man and the means adopted to remove foul air 
 have caused a notable decline in the cases of phthisis, and the only circum- 
 stance which has brought about this change at these places is the condition 
 of the air. The same results are seen on service in the field, where the rudest 
 shelter is better than overcrowded barracks. In the Afghan War pneumonia 
 was very prevalent and fatal in the overcrowded barracks, while there was 
 not a single case among those in tents ; distributing the men in tents had 
 the effect of at once stopping the disease. 
 
 Air rendered impure by exhalations from the sick is well known to be 
 injurious. In military hospitals hospital gangrene and erysipelas were 
 among the most prevalent diseases in former wars ; now they are almost 
 unknown, and the occurrence of a case is considered evidence of neglect. 
 The organic emanations being greater from the sick than from those in health 
 and the metamorphosis of tissue more active, pure air is essentially necessary 
 to facilitate recovery. 
 
 The effect of breathing air into which the products of gas combustion 
 have passed is to be seen in workmen who are obliged from the darkness of 
 their shops to burn gas during a large part of the day. Bronchial affections 
 are common, and in proportion to the amount of contamination of the air 
 they suffer from headache, drowsiness, and oppression. Another example 
 of the injurious effects produced by gas may be inferred from the fact 
 that in the Savings Bank Department in Queen Victoria Street, where 1200 
 persons are employed, the introduction of the electric light in place of gas has 
 so far reduced the absences from illness that the extra labour gained has 
 paid for the electric light. 
 
 Air polluted by sewage emanations, whether arising from sewers, drains^ 
 or cesspits, is capable of causing vomiting, diarrhoea, and great prostration. 
 When inhaled largely diluted it produces headache and a general low state 
 of health ; children appear to be more susceptible to its influence than grown- 
 up people ; they become languid and may suffer from diarrhoea and sore 
 throat. The special diseases that have been more particularly noticed in 
 connection with sewer air are enteric fever, diarrhoea, and diphtheria. As 
 regards enteric fever there is doubtless a distinct causal connection between 
 the inhalation of sewer air and the occurrence of the disease. The persistent 
 attacks of enteric fever, which formerly occurred at Eastney Barracks, were 
 due to sewer air being forced back by the tide, no traps or ventilating open- 
 ings being supplied ; since this was remedied and ventilation carried out no 
 case of fever has occurred. 
 
 On the other hand enteric fever does not appear to be more common 
 among sewer men than others, and those workmen employed on sewage 
 works do not furnish an unusual number of cases. 
 
 If we admit the extreme danger which arises from the inhalation of sewer 
 air, knowing that the specific cause lies in the intestinal discharges which 
 naturally pass into the sewers, every procurable means should be adopted to 
 prevent the entrance of sewer gas into houses, although the subject presents 
 difficulties which cannot always be explained. 
 
12 HYGIENE 
 
 With regard to diarrhoea a worse type generally prevails in badly drained 
 than in well-drained districts : this disease, though intimately associated 
 with soil temperature, is favoured by sewer emanations. In London a heavy 
 fall of rain has checked its spread — possibly by seahng traps which a 
 previous drought had caused to become dry, and thus preventing sewer gas 
 from escaping. 
 
 The spread of diphtheria has been ascribed to the pollution of air by 
 emanations from sewers, and certainly there is a close connection between 
 the sanitary condition of a district and the occurrence of this disease ; the in- 
 habitants of houses into which sewer gas enters are especial sufferers. Refer- 
 ence may be made to outbreaks recently recorded by the late Mr. Spear, of the 
 Local Government Board. There is no evidence to prove that the emanations 
 from well-managed sewage farms are injurious to health. Dr. Carpenter has 
 shown that the sewage farm at Beddington can be carried on without risk to 
 persons in the vicinity, and where exhalations have been said to produce 
 disease the fault has been with the improper treatment of the sewage and 
 not with the principle. 
 
 The fouling of streams and rivers does not furnish such clear evidence ; 
 though the cases recorded among residents in houses on the quays in Dublin 
 or in the worst districts in Lancashire show no great excess of disease, there 
 is nevertheless considerable proof that inhalation of offensive odours is often 
 productive of diarrhoea. Probably the results much depend on the dilution 
 of the sewage matter. When very dilute there appears to be little danger 
 from evaporation. 
 
 The air of graveyards contains an excess of CO2, and when they are densely 
 crowded, and deep burial is not insisted on, there are also found foetid organic 
 vapours, sulphuretted hydrogen, and ammonium sulphide, which increase the 
 sickness and mortality among those living in the immediate vicinity ; any 
 disease occurring in such a situation assumes a virulent and unfavourable type. 
 But under modern regulations there appears to be no danger from this cause. 
 Care must be taken, however, that no contamination reaches the water supply, 
 especially that used for drinking purposes. In India it is well known that 
 cholera assumes a more severe and fatal type in stations where barracks are 
 built in close proximity to the sites of old burial-grounds. A remarkable 
 case occurred in Yorkshire ^ a few years ago, in connection with a churchyard, 
 where a number of persons who died from scarlet fever had been buried thirty 
 years previously. A part of the churchyard was closed, but was afterwards 
 iacluded in the garden of the Rector, who had it dug up, whereupon scarlet 
 fever broke out in his family and spread to the neighbouring houses. 
 Gravediggers appear to suffer no injurious effects from their calling ; no 
 excess of mortality among them is recorded. 
 
 The elHuvia arising from decomposing carcases produce diarrhoea, dysen- 
 tery, and a low febrile condition ; this has been especially noticed in military 
 campaigns, where it is often impossible to bury horses that have died or been 
 killed in action. In well-managed knackeries the men do not appear to 
 suffer, although it is said that glanders and malignant pustule have been 
 caught in this way. 
 
 The air of brickfields, especially those in which the bricks are burnt in a 
 quadrangular pile and not in kilns, is very offensive ; sulphuretted hydrogen, 
 <3arbon dioxide, carbon monoxide, and foetid organic vapours with thick smoke 
 are given off, particularly when house refuse is used in the manufacture. 
 The emanations are acid and destroy vegetation ; when inhaled they are 
 very irritant. In burning cement the same disagreeable effects are produced, 
 
 • Sanitary Journal, December 17, 1888. 
 
AIB 
 
 13 
 
 the gases given off being chiefly CO2 and SH^, also volatile cyanides in some 
 instances, which are very poisonous. 
 
 The air of marshes has given rise to malarial fevers, the specific poison 
 being rapidly carried by the v^ind to a considerable distance ; it is more 
 intense near the ground than a few feet above it, and is easily stopped by 
 mechanical barriers. This disease is now seldom seen in England, but is 
 very prevalent in the tropics during the rainy season. 
 
 ON WHAT BASES AKE WE TO CALCULATE THE AMOUNT OF FRESH 
 
 AIR REQUIRED? 
 
 In order to calculate the amount of fresh air required to maintain an in- 
 habited room or enclosed space in a well-ventilated condition, it is necessary 
 (1) to know the nature and amount of the impurities that are added to the 
 air by reason of the presence of human beings ; (2) to have some means of 
 determining the presence of such impurities, and, if present, their amount ; 
 (3) to fix on some standard of ventilation, or limit in the amount of impurities 
 which must not be exceeded in an air-space, if such space is to be kept in a 
 proper and wholesome condition. 
 
 It will be convenient to consider, first of all, the case of ordinary dwell- 
 ings occupied by healthy persons, and, subsequently, certain special condi- 
 tions, as those of schools, factories, and hospitals. 
 
 1. The impurities present in an air-space that are due to the fact of its 
 being inhabited fall under the three heads of (A) those that are derived 
 from the inhabitants themselves ; (B) those that are produced by the arti- 
 ficial lighting or heating of the chamber ; and (C) those derived from the 
 walls, furniture, &c. of the room. 
 
 A. The first category may further be considered under the two divisions 
 of the impurities due to (1) the breath and (2) the perspiration. 
 
 (1) Impurities due to the Breath 
 
 The changes that take place in air that has been respired are the 
 following : {a) the temperature is raised ; (&) consequently the volume is in- 
 creased, but if the inspired and expired air be measured at the same tempera- 
 ture and pressure there is a diminution in volume ; (c) there is an increase 
 in the watery vapour ; {d) also an increase in the carbon dioxide ; {e) nitrogen 
 and (J) ammonia ; [g) the oxygen is diminished ; {h) there is an addition to 
 the air of hydrogen ; {i) marsh gas ; and {h) organic matter. Of these several 
 alterations in the composition of the air the increase in the carbon dioxide 
 and watery vapour, and the addition of organic matter, are the most important 
 from a hygienic point of view. 
 
 The composition of expired air by volume may be stated as — 
 
 
 Per cent. 
 
 
 Oxygen 
 
 . 16-033 
 
 Hydrogen . . trace 
 
 Nitrogen 
 
 . 79-557 
 
 Methyl hydride (CH^) trace 
 
 Carbon dioxide (COo) . 
 
 . 4-380 
 
 Aqueous vaiDour. . nearly to 
 
 Ammonia (NH3) . 
 
 traces 
 
 saturation 
 
 (i) Carbon Dioxide 
 
 The amount of CO2 exhaled in respiration has been investigated by 
 
 numerous observers, the quantity estimated varying from 31 '5 grammes 
 
 (Ranke) to 37'5 grammes (Vierordt), equalling 0'56 to 0*67 cubic foot, 
 
 every hour. There are very many influences at work to cause varia- 
 
14 
 
 HYGIENE 
 
 tion, and the methods of estimation and apparatus required are delicate 
 and complicated ; the determination, therefore, is a matter of some difficulty. 
 The observations of Petteukofer may be taken as being exceedingly accurate 
 and trustworthy. He found that a man aged twenty-eight years, weighing 
 132 lb., evolved hourly in complete repose during the night 0*56 cubic foot, in 
 gentle exertion during the dayO"78 cubic foot, in hard work during the day 1*52 
 ■cubic foot. These figures give in round numbers respectively— 
 
 In complete repose during the night . -004 cubic foot C0._. per lb. of body-weight 
 In gentle exertion during the day . "000 „ „ 
 
 In hard work during the day . . •012 ,, „ 
 
 Taking now the average weight of adult males as 150 lb., of adult females 
 as 100 lb., and of children as 75 lb., and again using round numbers, these 
 figures give the following data : — 
 
 Average hourly Excretion of CO., by Lungs, in cubic feet 
 
 ^-•ePose I^I-^Jf 
 
 In hard work 
 
 Adult males . 
 Adult females 
 Children 
 
 •6 
 •4 
 •3 
 
 •90 
 •60 
 
 •45 
 
 1^8 
 1-2 
 0-9 
 
 The influences that modify the excretion of CO.2 are chiefly the following : 
 (1) Age. — The amount is increased up to about thirty years ; it remains station- 
 ary from thirty to forty-five ; after forty-five years it diminishes. (2) Sex. — 
 After eight years males give off considerably more than females (according to 
 Andral and Gavarret this increase is about one-third). (3) Development. — 
 More CO2 is given off by the vigorous and robust than by the slender, this 
 increase being more proportionate to the muscular development than to mere 
 size and weight of the body. (4) Sleep. — Less CO2 is evolved during sleep than 
 when lying awake and at rest. (5) Food and fasting. — Abstinence diminishes, 
 and the taking of food increases, the evolution of CO2, the amount of increase 
 varying with the nature of the food. (6) Muscular exertion greatly increases 
 the CO2 given off. (7) The temperature of the surrounding air, (8) the time 
 of day, and (9) the season of year all exercise an influence, the excretion 
 being increased by cold, about the middle of the day, and in the spring ; and 
 decreased by heat, about midnight, and in the autumn. 
 
 It is evidently, therefore, a matter of great difficulty to determine the 
 amount of carbon dioxide habitually given off by an average population, on 
 account of these numerous sources of modification ; and any attempt at 
 stating a normal or standard amount must be accepted as admitting of varia- 
 tion within very wide limits. In. repose ' for- a mixed community a general 
 average of -6 cubic foot per hour may be adopted ' (Parkes and de Chaumont) ; 
 and it should be borne in mind that (1) for muscular adult males a higher 
 figure, -7 or -72, should be taken ; and (2) that children, although evolving 
 a less amount absolutely than adults, give off relatively, in proportion to 
 their body-weight, nearly twice as much. 
 
 (ii) Aqiieous Vapour 
 
 Whatever be the hygrometric state of the atmosphere, the expired air is 
 nearly saturated with moisture. The absolute amount thus added to the 
 atmosphere varies with (1) the temperature of the expired air and (2) the 
 quantity of watery vapour already existing in the air before it was respired. 
 The temperature of expired air varies only within narrow limits ; it is usually 
 
AIB 15 
 
 higher than that of the surrounding atmosphere, but may he lower ; it ia 
 sh'ghtly below the blood temperature, being about 93° F. to 97° F. According 
 to Pettenkofer and Voit, at a temperature of 59° F., and the relative humidity 
 of the air being 75 per cent, of saturation, an adult gives to the air 10- 19 oz. 
 (286 grammes) of watery vapour in twenty-four hours. Other observers 
 estimate the amount as from 200 to 300 grammes f about 7 to 11 oz.j ; according 
 to Valentin it is as much as 640 grammes (22'5 oz.) 
 
 (iii) Organic Matter 
 
 The nature of the organic matter given off by the lungs has not been pre- 
 cisely determined : it is odorous and putrescible ; it decolorises solution of 
 permanganate of potash, and is therefore oxidisable ; it also yields ammonia, 
 and is therefore nitrogenous. It is doubtless of a mixed composition, mole- 
 cular rather than gaseous ; and, in addition to substances derived from the 
 lungs, the breath contains particles of epithelium and fatty mattei's from the 
 mouth and pharynx, and in some cases organic effluvia from the stomach. 
 
 Neither has the amount of this complex organic matter been exactly 
 estimated. Carnelley, Haldane, and Anderson made some careful experiments 
 (too few, however, to warrant a general deduction), in which the excess of 
 oxidisable matter in the expired air over that present in the room was found 
 to vary from 1*7 to 13*6, giving an average for one observer of 7*6 and for 
 another 8*3, These figures are volumes of oxygen required to oxidise the 
 oxidisable matter per million volumes of air. The amount is, therefore, by 
 no means constant, and the range of variation is so wide that the averages 
 are not of much value. 
 
 (2) Imjmrities due to Perspiration 
 
 The matters derived from the cutaneous secretion are both organic and 
 inorganic : the chief are water, sodium chloride, and other inorganic salts in 
 small quantity, various fatty acids, neutral salts, and ammonia (urea) ; in 
 addition particles of epidermis constantly become detached and float off into 
 the surrounding atmosphere. The quantity of perspiration thus given off is 
 large, but very variable : about 2 lb. (or 900 grammes) of fluid during the 
 twenty-four hours (Seguin) may be taken as an average, containing 1*8 per 
 cent, of solids, of which 1*2 per cent, are organic substances. 
 
 B. Impueities due to Combustion 
 
 (1) The products of the combustion of coal are carbon, carbon dioxide 
 and monoxide, sulphur, sulphur dioxide and sulphuric acid, ammonium 
 compounds, and water. "Wood gives rise to carbon dioxide, carbon monoxide, 
 and water. As these substances commonly pass out into the outer air, they 
 do not require further mention in this place. 
 
 (2) The substances resulting from the combustion of coal gas, oil, and 
 candles are usually diffused more or less through dwelling rooms, although 
 they can, and should, be carried off by suitable means, and the air thereby 
 freed from a very considerable amount of impurity. The chief products of the 
 combustion of average coal gas are nitrogen (67 per cent.), water (16 per 
 cent.), carbon dioxide (7 per cent.), carbon monoxide, if the combustion be 
 imperfect (5 or 6 per cent.), sulphurous acid, and ammonia. One cubic foot 
 of gas will unite with from about 1 to If cubic foot of oxygen, according 
 to its quality, requiring, therefore, from about 5 to 8 cubic feet of air, and 
 producing on an average about 2 cubic feet of carbon dioxide. An ordinary 
 gas burner burns between 3 and 5 feet per hour. 
 
16 HYGIENE 
 
 An ordinary oil lamp burns about 150 grains of oil hourly, consuming 
 the oxygen of rather more than 3 cubic feet of air, and producing a little 
 more than half a cubic foot of carbon dioxide ; 1 lb. of oil requires about 150 
 cubic feet of air for complete combustion. 
 
 A candle burning 320 grains per hour produces about -4 cubic foot of 
 carbon dioxide in that time (Erismann). 
 
 C. lairUEITIES DEEIVED FROM THE WaLLS, FlOORS, &C. 
 
 In addition to the matters already mentioned, the air of inhabited places 
 contains sohd particles, not derivable from either of the sources that have 
 just been considered. Under the name of dtist may be included mineral 
 particles, vegetable and animal d&bris, and dead matter blown in from the 
 outside, or derived from the surfaces of floors, walls, furniture, &c. In ordi- 
 nary dwellings this dust is, unless in extreme amount, hygienically of little 
 consequence. But either attached to these inert particles or floating freely 
 are great numbers of living micro-organisms, which, though as a rule harm- 
 less to the healthy inmate, may under certain circumstances possess the 
 greatest significance. Carnelley, Haldane, and Anderson have shown that 
 the micro-organisms do not come, to any large extent, from the persons pre- 
 sent in the room, neither from the lungs nor from the skin ; they must there- 
 fore come from the room itself. They are found in greatest number in houses 
 that are old, overcrowded, and dirty. When the air is at rest they rapidly 
 fall to the ground, being again dispersed throughout the room when the air is 
 disturbed, particularly when much dust is raised. These minute organisms 
 belong to the groups of moulds [Hypliomycetes), yeasts (Saccharoimjcetes), 
 and bacteria {Schizomycetes), the latter being much the most numerous. 
 
 2. From the above brief summary it is seen that the air of inhabited 
 rooms or confined spaces is rendered impure by the addition to it of solid, 
 liquid, and gaseous matters, both inorganic and organic, dead and living, 
 some derived from the occupants, some from the means used for warming 
 and hghting, some from the rooms themselves. The question has now to be 
 considered, How can the presence of these impurities be detected and their 
 amount estimated ? 
 
 The means at our disposal to attain these objects are (1) the use of the 
 senses ; (2) physical and (3) chemical methods, and (4) examination by the 
 microscope, with which may be included cultivation methods for the detec- 
 tion and enumeration of micro-organisms. 
 
 The sense of smell detects an excess of organic matter in an air-space, as 
 evidenced by the closeness or offensive odour of the air ; hygrometers, or the 
 wet and dry bulb thermometer, show the amount of watery vapour present. 
 The carbon dioxide can be readily estimated by shaking up known quantities 
 of lime or baryta water and air and comparing the alkalinity of the liquid 
 before and after the operation. The number of micro-organisms present and 
 their nature can be estimated by aspirating a known quantity of air through a 
 suitable apparatus, and preparing cultivations in nutrient gelatine. 
 
 These and other methods are described subsequently in the section on the 
 Examination of Air. 
 
 It is universally agreed that the organic matter given off by the lungs 
 and skin is the most noxious of all the impurities present in the air of an 
 inhabited space, but, unfortunately, the means for the exact determination 
 of its amount are both imperfect and difficult of application. On the other 
 hand the estimation of the amount of carbon dioxide can be accomplished 
 
AIB 17 
 
 with great ease and very fair accuracy. Frora the numerous experiments in 
 barracks and hospitals conducted by several observers it appears that the 
 oxidisable matter present in air (probably organic), as shown by the amount 
 of potassium permanganate deoxidised, is generally in proportion to the 
 amount of carbon dioxide present due to respiration. The late Dr. de 
 Chaumont, from a large series of observations, proved that the amount of 
 organic impurity present, as shown by the sense of smell carefully employed, 
 increased pari passu with the carbon dioxide of respiration, and he deduced 
 certain general rules from this coincident increase. Carnelley, Haldane, and 
 Anderson do not appear to have found so close a connection between the 
 organic matter and the carbon dioxide, and none at all between the carbon 
 dioxide and the number of micro-organisms. For the present, however, de 
 Chaumont's researches give ample justification for the belief that a com- 
 parative estimate of the organic purity or impurity of an air-space can be 
 safely made from a determination of the amount of CO2 present, making 
 allowance for the quantity of CO2 in the external air.^ 
 
 3. From what has been said in the preceding paragraphs it may be 
 stated : (1) that the chief impurity in an inhabited air-space is the organic 
 matter evolved in respiration and perspiration ; (2) that the amount of this 
 present may be estimated relatively by determining the amount of carbon 
 dioxide present ; (3) that the amount of carbon dioxide evolved by individuals 
 can be calculated, not exactly, but with a considerable degree of accuracy ; 
 therefore (4) the condition of the air-space of known size tenanted by any 
 number of individuals can be calculated, as regards the quantity of CO 2, 
 at the end of one or more hours ; and therefore relatively its condition 
 as regards organic impurity ; and (5) if a standard amount of CO2 be fixed 
 on, a limit which should not be exceeded, we may ascertain by calculation 
 the quantity of fresh air that must be supplied in order to restrain the CO2 
 within these bounds, and therefore relatively prevent the organic impurity 
 from exceeding a safe and wholesome limit. 
 
 This standard, or limit, has been fixed by Eoth and Lex, and by de 
 Chaumont, as 0*6 per 1000 volumes ; by Pettenkofer and by Carnelley, 
 Haldane and Anderson, as 1 per 1000 volumes ; by all observers the amount 
 present normally in the atmosphere has been taken as 0*4 ; therefore the 
 excess over this natural quantity should not be more than 0'2 or 0'6 per 1000 
 volumes respectively. Morin and Eanke advocated the supply of fresh air 
 in such proportions that the excess of COg due to impurity from respiration 
 should not exceed 0*33 per 1000 volumes. 
 
 The observations of de Chaumont have been generally accepted, and for 
 the reasons already stated they may be received with confidence. He took 
 as the standard ' the point at which there is no sensible difference between 
 the air of an inhabited space and the external air,' as determined by the 
 sense of smell. This standard may not be easy to attain in every case, but 
 it is better to have a high standard at any rate to aim at. As perfect purity 
 of air in a confined space is out of the question, one must be content with 
 something short of this, but as a theoretical standard the condition should 
 be such that no unpleasant smell or closeness should be appreciable. The 
 temperature and the relative degree of humidity have an influence on the 
 readiness with which smell of organic impurity is perceived ; they also them- 
 
 ' A reference to de Chaumont's papers in the Proceedings of the Royal Society for 
 1875, No. 158, and 1876, No. 171, will show the extreme care taken in drawing conclusiona 
 from the different series of observations, and a mathematical proof of the close approsima- 
 tion to truth of these conclusions. 
 
 VOL. I. C 
 
18 HYGIENE 
 
 selves give indications as to the efficienc}^ of ventilation or the reverse. From 
 de Chaumont's observations, 63° F. and 73 per cent, of humidity may be 
 taken approximately as standards. 
 
 Carnelley, Haldane, and Anderson, as just mentioned, have fixed on a 
 lower standard of purity, that is, they propose a higher Hmit of COo, viz. 
 0*6 volume per 1000 above that in the external air. They also propose 
 2 volumes per million of oxygen required for oxidation as a standard for the 
 ' organic matter ' (or rather the ' total oxidisable matter.' See Analysis of 
 Am, p. 23). .The number of micro-organisms present should not exceed 
 20 per litre, and the ratio of bacteria to moulds should not exceed 30 to 1. 
 
 Some such standards being agreed upon, it becomes now a matter for 
 calculation to ascertain the quantity of fresh air that must be supplied in 
 order to maintain a space in a well-ventilated condition. 
 
 HOW MUCH FEESH AIE IS EEQUHIED TO EEEP AN INHABITED 
 AIR-SPACE HEALTHY? 
 
 1. If e = amount of CO2 exhaled per head per hour in cubic feet, 
 
 r = admissible Hmit of CO.,, due to respiratory impurity, stated 
 
 per cubic foot, 
 d = delivery of fresh air required in cubic feet per head per hour, 
 
 then — = d. 
 
 r 
 
 Taking '6 cubic foot as the average amount of CO2 exhaled in repose, 
 and '2 per 1000 as the limit of respiratory impurity, that is "0002 cubic foot^ 
 
 = 3000 = delivery of fresh air required per head per hour. 
 
 In this formula if r be ratio per 1000 instead of per cubic foot, then d 
 will be in thousands of cubic feet, thus : 
 
 •A 
 
 — = 3 thousand cubic feet. 
 'A 
 
 2. If r = admissible limit of respiratory impurity, 
 
 Ti = respiratory impurity, stated in ratio per 1000 of CO2, exist- 
 ing in 
 c := air-space, 
 
 d = dehvery of fresh air required in cubic feet, 
 then (n-r)xc^^. 
 
 r 
 
 that is, as the admissible limit : excess of existing over admissible ratio 
 : : amount of air-space : amount of fresh air required. Thus, if there be one 
 person in a cubic space of 1000 feet, at the end of one hour the CO2 exlialed 
 
 wiU be -6 cubic foot = -6 per 1000 : then ("6 - -2) x 1000 ^ ^OOO 
 
 'A 
 
 = cubic feet of fresh air required during the first hour. 
 
 Again, if there be three muscular adult males, averaging 12 stone in 
 
 weight, in a space of 2000 cubic feet, and the CO2 evolved = 3 X'7 = 2*1 
 
 2'1 
 cubic feet, which in a space of 2000 cubic feet = -^ = 1'05 per 1000 = r; 
 
 j^^^ (l:55-:2)xJO0O^g50Oeubicfeet 
 
 — 2838 cubic feet per head required during the first hour. 
 
AIB 
 
 19 
 
 After the first hour the size of the cubic space is of little consequence in 
 most cases, the amount of fresh air required from without depending on the 
 amount of CO2 exhaled. In the example just given 2833 cubic feet per 
 head were required during the first hour ; after this, whether the cubic 
 
 space be 200 feet or 2000 feet, the delivery of fresh air must be — = ^ 
 
 = 3*5 thousands = 3500 cubic feet every hour. 
 
 3. In formula (l)if ri, the observed ratio of impurity, be substituted for 
 r, from the condition of the air shown thereby may be calculated the amount 
 of fresh air supplied and utilised : 
 
 — = d = amount of fresh air that has been' supplied and utilised. 
 
 Thus, if the CO2 due to respiratory impurity be found to be 1*05 per 
 1000, the CO2 exhaled being -7 cubic foot per head, 
 
 •7 • • 
 
 then — -- = -6 = '6 thousands = 666 cubic feet per head per hour supplied. 
 1*05 
 
 4. To calculate the probable condition of an air-space to which a known 
 quantity of air has been supplied : 
 
 e 
 
 Let e = -6,d = 3000 ; then ^ - = -0002 cubic foot CO2 per cubic foot of 
 
 air = '2 per 1000 (or this maybe stated as _= •2). 
 
 o 
 
 Again, let e = '7, d = 1200 ; then 
 
 1200 
 
 = 00058 = -58 per 1000 CO2. 
 
 5. If the figures on page 14 be taken as fairly representing the average 
 weights of adults, male and female, and children, and (in round numbers) 
 the quantities of CO2 excreted hourly, the amount of fresh air required will 
 be as follows : 
 
 Amount of Air required hourly, in cubic feet. 
 
 - 
 
 In repose 
 
 In gentle 
 exertion 
 
 In hard work 
 
 Adult males . 
 Adult females 
 Children 
 
 3000 
 2000 
 1500 
 
 4500 
 3000 
 2250 
 
 9000 
 6000 
 4500 
 
 For muscular adults weighing over 12 stone — as, for instance, navvies— 
 a larger amount would be required, about 3600 cubic feet in repose, with a 
 proportionate increase, under the circumstances of light and hard work. 
 
 6. Amount required for lights.— -Fov each cubic foot of gas burnt 
 Wolpert has calculated that 1800 cubic feet of air should be suppKed, 
 whereby the ratio of CO2 due to combustion would be kept down to about 
 I'l per 1000, and the sulphur dioxide and other combustion-products safely 
 diluted. Each ordinary gas burner would require from 5400 to 9000 cubic 
 feet of air per hour. Oil lamps and candles do not generally require a 
 special supply of air, not because the CO2 evolved by their combustion is 
 less, for equal illuminating powers, than by that of gas, but because so much 
 more gas is generally burnt, giving more light and heat, and causing much 
 greater deterioration of the air of the room. 
 
 c2 
 
20 HYGIENE 
 
 HOW MUCH INITIAL CUBIC SPACE OUGHT TO BE PEOVIDED FOR 
 
 EACH INMATE? 
 
 The amount of fresh air required per head having been agreed upon, 
 according to the foregoing considerations, the answer to the question of how 
 much cubic space is needed will depend on the ease with which the air in 
 the air-space can be renewed. The larger the room the less frequently 
 need the contained air be displaced by fresh air from outside ; the smaller 
 the room the more often must this change take place, and the greater difficulty 
 is experienced in doing this effectually without causing draught. In an 
 air-space containing 1000 cubic feet per head the air needs only to be 
 changed three times in an hour to provide the necessary 3000 cubic feet ; 
 but if the space is not more than 500 cubic feet, obviously six changes 
 per hour are required to supply the same quantity of fresh air. With the 
 best mechanical means of ventilation even this can be effected without per- 
 ceptible draught, as in Pettenkofer's experimental room at Munich, where 
 2640 cubic feet are drawn hourly by a steam engine through a space of 424 
 cubic feet. But in temperate climates and under ordinary circumstances 
 three changes per hour are all that can be borne ; more frequent change 
 than this produces cold currents of air and draughts. Therefore, for sleep- 
 ing apartments generally, 1000 cubic feet per head should be allowed ; in 
 the case of children and old people so large a space is not necessary — 
 probably 500 to 600 cubic feet would be sufficient. These dimensions are 
 higher than are usually allowed, but, as Dr. Parkes says, ' after all, the ques- 
 tion is, not what is likely to be done, but what ought to be done ; and 
 it is an encouraging fact that in most things in this world when a right 
 course is recognised it is somehow or other eventually followed.' 
 
 AMOUNT OF FEESH AIE AND CUBIC SPACE EEQUIRED IN 
 HOSPITALS, SCHOOLS, &c. 
 
 Hospitals. — It would naturally be expected that a greater quantity of 
 fresh air would be required to keep the air of a sick-chamber in a good 
 condition than the air of a similar room occupied by the healthy. Dr. de 
 Chaumont's observations point to the conclusion that about one-fourth 
 more fresh air should be suppUed, as the smell of organic matter was quite 
 distinct in hospitals when the CO 2 due to respiratory impurity was 0'166 per 
 1000, as against 0*208 per 1000 in rooms occupied by healthy persons ; 
 therefore the hourly supply should be 4000 cubic feet. 
 
 The cubic space should be increased in at least the same proportion, 
 viz. from 1000 to 1250 or 1300 feet. The impurities derived from the 
 bodies of the sick ought to be removed as quickly as possible, and being to 
 a large extent particulate, and therefore not removable by diffusion, there is 
 all the greater need for a large dilution with fresh air and exposure to its 
 oxidising and purifying effects ; this can only be done efficiently with ample 
 cubic space, as draughts have especially to be avoided in the case of sick- 
 rooms. For purposes of convenience of nursing and attendance a floor- 
 space of 100 or 120 square feet is considered desirable in hospitals ; with a 
 height of 12 or 18 feet this would give from 1200 to 1500 cubic feet. 
 These measurements are applicable to ordinary cases of sickness ; in certain 
 cases where there are offensive discharges, and in cases of infectious disease, 
 especially typhus fever, and in pyaemia, a much larger amount of fresh air must 
 
AIB 21 
 
 be supplied — 5000 or GOOO or more cubic feet hourly — indeed, treatment in 
 what is practically the open air often has the best results. 
 
 Schools. — The amount of fresh air required for children has been already 
 stated, p. 19 ; of course this requires modification according to age. The 
 cubic space provided by the London School Board is 130 cubic feet per 
 head, being 10 square feet of floor-space and 13 feet of height. The 
 Education Department of the Privy Council endeavour to secure at least 
 80 cubic feet and 8 square feet for each unit of average attendance in public 
 elementary schools in England. Carnelley, Haldane, and Anderson found 
 an average of 160 to 170 cubic feet per head in the Board schools of Dundee. 
 In France the allowance is from 120 to 140 cubic feet per head. All these 
 dimensions seem smaller than would theoretically be deemed advisable : 
 with 200 cubic feet per head the air would require changing six times per 
 hour to keep the CO2 due to respiratory impurity down to 0-25 per 1000 vols. 
 
 f^ = r, : = -00025 GOo per cubic foot.^ 
 
 W 6 X 200 ^ ^ J 
 
 The headaches and other symptoms ascribed to over-pressure in Board 
 schools may often really be attributable to the breathing of a foul atmosphere 
 for many hours in succession. In the Dundee schools, however, that were 
 ventilated by mechanical means, the above observers found a fairly good 
 condition to exist, in spite of the small cubic space ; the CO2, however, was 
 high (judged by the standard adopted in this article), averaging -89 per 
 1000 vols, above that in the outside air. The standard proposed by 
 Messrs. Carnelley, Haldane, and Anderson for schools is 0*9 vol. CO2 per 
 1000 above outside air, 2 vols, of oxygen per 1,000,000, and 20 micro- 
 organisms per litre. 
 
 Factories. — The special circumstances resulting from the different kinds 
 of operations carried on in different factories will modify the general rules 
 that have been laid down ; in a great many cases special impurities are 
 added to the air, which require removal by special means in order ta 
 maintain a wholesome condition of the air-space. 
 
 MEASUEEMENT OP CUBIC SPACE 
 
 The measurement of the amount of cubic air-space in any room or in- 
 habited place may be conveniently carried oiit as follows : — 
 
 1. If the room be square or oblong, with a flat ceiling, the cubic space 
 will be simply the three dimensions of length, breadth, and height multiplied 
 into each other. If the room be circular, or of irregular form, with a curved 
 ceiling or with irregular projections, the rules for the measurement of 
 circles &c. must be used. Irregularly shaped places, if rectilinear, can be 
 divided into triangles and then measured ; or, if bounded by curved lines, 
 they can be divided up into segments of circles &c. 
 
 2. The room having been measured, all recesses, such as doorways, 
 window-recesses, &c., should be added in. 
 
 3. All projections, such as cupboards, solid pieces of furniture, &c., should 
 be deducted. 
 
 4. Deduction must be made for the cubic space occupied by the inmates ; 
 an average amount of space so occupied by adults is 3 cubic feet; an 
 approximate rule is weight in stones -^ 4 = cubic feet occupied. 
 
 6. In the case of bedrooms deduction must be made for bedding 
 and bed furniture, which may occupy on an average about 10 cubic feet for 
 each person. 
 
22 HYGIENE 
 
 It is more conveBient to make the measurements in feet and decimals of 
 a foot than in feet and inches. 
 
 Mules for Superficial Measurement. 
 Area of circle . . = vrr^ = 3-1416 x square of radius. 
 
 „ = , — = square of circumference x •0796. 
 
 4- 
 
 Circumference of circle = tt 2 r = 31416 x diameter, 
 
 C 
 Diameter of circle . = _ = circimiference x •3183. 
 
 Area of ellipse . . =!L ^= 3-1416 x ^ long diameter x | short 
 
 diameter. 
 Area of square . . = square any one of the sides, or, multiply one side 
 
 into another. 
 Area of rectangle . . = multiply together two sides perpendicular to each 
 
 other. 
 Area of a triangle . = base x h height, or height x ^ base. 
 To find area of any rectilineal figure : divide into triangles and take the sum 
 
 of their areas. 
 
 Area of segment of circles (f x chord x height) + £H^^_2l^£^. 
 
 2 X chord 
 
 Bules for Cubical Measurement. 
 
 Cube or solid rectangle = length x breadth x height. 
 Solid triangle . . = section area of triangle x height. 
 Cylinder . . . = section of area of base x height. 
 Cone or pyramid . = area of base x ^ height. 
 Dome . . . . = area of base x f height. 
 
 A *2 
 
 Sphere , , . = or, diameter cubed x •5236. 
 
 o 
 
 Nearly every inhabited space can be divided up into figures which can 
 be measured according to the above short rules. For instance, a bell tent 
 is a cone resting on a short cylinder ; a hall with a semicircular roof is a 
 half cylinder resting on a rectangle, or if with a segmental roof it must be 
 measured as a solid segment of a circle. 
 
 EXAMINATION OF AIR 
 
 For hygienic purposes we can obtain much information by considering 
 the subject in the following general order : — 
 
 1. By the senses. 
 
 2. Chemical examination of the constituents of air. 
 
 3. Microscopic examination of the suspended matters in air. 
 
 4. A study of the micro-organisms obtained by cultivation from air. 
 
 Examination by the Senses 
 
 It is now generally admitted that it is the organic matter in air, either 
 suspended or in the form of vapour, that is the impurity we have chiefly to 
 deal with in inhabited air-spaces, and that it is this which gives the peculiar 
 foetid smell so disagreeable on entering an ill-ventilated air-space. It seems 
 also certain that these organic products are in some way closely connected 
 with the humidity. 
 
AIB 23 
 
 Though the nature of this organic matter varies to some extent, but one 
 fact remains clear — we must dilute the air in the air-space with x)ure air 
 until the amount present, as judged by the sense of smell, does not differ 
 sensibly from the external air. Fortunately we have not to depend on this 
 test alone, for observations show that the amount of organic impurity in- 
 creases pari passu with the carbon dioxide evolved by the persons &c. inhabit- 
 ing the air-space. Dr. de Chaumont, who was the first to formulate a definite 
 rule, adopted as a standard the point at which there is no sensible differ- 
 ence between the air of an inhabited space and the external air as determined 
 by the sense of smell. This he reduced to four orders or classes as follows : 
 
 1. ' Fresh,' or not differing sensibly from the outer air. 
 
 2. ' Eather close,' indicating the point at which organic matter becomes 
 perceptible. 
 
 3. ' Close,' indicating the point at which organic matter becomes decidedly 
 disagreeable. 
 
 4. ' Very close,' organic matter offensive and oppressive, indicating the 
 point at which the differentiation by the senses is reached. 
 
 From the analyses of the different classes and the data these gave the 
 following conditions of ventilation were arrived at : — 
 
 1. ' Fresh ' : Temperature about 63° F. Aqueous vapour shall not exceed 
 4*7 grains per cubic foot. Carbon dioxide shall not exceed the amount in 
 the outer air by more than 0*2 per 1000 volumes. Ventilation here is good. 
 
 2. ' Eather close ' : Vapour in a cubic foot of air exceeds 4*7 grains. 
 Carbon dioxide in excess over outer air, ratio reaching 0*4 per 1000 volumes. 
 Ventilation here ceases to be good. 
 
 3. ' Close ' : Vapour exceeds 4*7 grains per cubic foot. Carbon dioxide 
 in excess over outer air to the amount of 0"67 per 1000 volumes. Ventilation 
 here begins to be decidedly bad. 
 
 4. ' Very close ' : Vapour reaches 5°1 grains per cubic foot. Carbon 
 dioxide in excess over the amount in the outer air beyond 0"9 per 1000 
 volumes. 
 
 Chemical Analysis 
 
 This should include the following points : — 
 
 1. The amount of COg. This is taken as a measure of all impurities, 
 
 2. The amountofoxidisable substances, as judged by the amount of oxygen 
 absorbed from a standard solution of potassium permanganate. 
 
 3. The amount of free ammonia. 
 
 4. The amount of albuminoid ammonia. 
 
 5. The amount of nitrous and nitric acids. 
 
 6. The presence of sulphuretted hydrogen or any of its compounds. 
 
 7. The presence or absence of ozone. 
 
 8. The amount of watery vapour. 
 
 1. Estimation of Carbon Dioxide 
 
 For its determination the following method, introduced by Pettenkofer, 
 is the one usually adopted on account of its simplicity and practical utility. 
 A glass jar or vessel capable of holding about one gallon is taken, and its 
 capacity accurately measured ; this is best done by filling the jar with water 
 and measuring the contents by means of a litre or pint measure. Dr. Angus 
 Smith recommends extracting the air from the bottle by a bellows, while 
 Mr. Wynter Blyth would fill the jar by the same means. In the latter 
 method there is always great danger of introducing impurities. Perhaps the 
 best plan is to fill the jar with clean water and empty it in that part of the 
 
24 HYGIENE 
 
 air-space it is desired to examine, taking care to allow it to drain well. When 
 this is done 60 c.c. of caustic lime or baryta water are put into the jar and 
 the mouth closed with an mdia-rubber cap. The vessel is then slightly tilted, 
 first on one side, then on the other, so as to allow the lime or baryta water 
 to run over the sides, and to thus facilitate its exposure to the air. 
 
 If lime water is used, the vessel and its contents should be allowed to 
 stand for six or eight hours ; but if baryta water has been selected, a much 
 shorter time is sufficient — less than an hour. 
 
 The CO2 is absorbed by the lime or baryta water, and the causticity of 
 these substances is lessened in proportion. The loss of strength of the lime 
 Avater therefore measures the amount of carbon dioxide present. Freshly 
 prepared lime water is perhaps the most convenient, and the indications 
 given with it are sufficiently accurate for all purposes. 
 
 The causticity of the lime water is determined by means of a solution of 
 crystalline oxalic acid, which is made as follows : — 
 
 Lime. Oxalic acid. 
 56 : 126 :: 1 : x = 2-25. 
 K therefore 2*25 grammes of oxalic acid are dissolved in 1 litre of distilled 
 water, we have 
 
 1 c.c. = 2"25 milligrammes of oxalic acid. 
 
 1 c.c. neutralises 1 milligramme of CaO, forming oxalate of lime. 
 
 Take 30 c.c. of freshly prepared lime water and exactly neutralise with 
 the standard oxalic acid solution. Several * indicators ' may be used for 
 determining the exact point of neutralisation, but good tin-meric paper is 
 generally the one most available ; a solution of phenol-phthalein gives very 
 exact indications ; when the point of neutralisation is reached the pink 
 colour is discharged. The milligrammes of lime in the 30 c.c. are equal to 
 the number of c.c. of the oxalic acid solution used, and this is usually between 
 30 c.c. and 40 c.c. 
 
 After the lime water in the jar has absorbed the CO2, 30 c.c. of the solu- 
 tion are taken out and tested with the standard oxaUc acid solution as before ; 
 the difference shows the milligrammes of lime which have united with the 
 CO2. The milligrammes of lime must be converted into CO2 by calculation 
 of the proportion between their molecular weights, then the CO2 converted 
 into cubic centimetres by calculation of the proportion between weight and 
 volume. 
 
 In measuring the total capacity of the jar 60 c.c. must be deducted, this 
 being the space occupied by the hme water put in. State the capacity in 
 litres and decimals ; divide the c.c. of CO2 obtained by the corrected capacity 
 of the jar ; the result is the c.c. of COg in a litre or per 1000 volumes 
 of air. 
 
 Example. — 
 
 The first alkalinity of the lime water was for 30 c.c. 39"0 
 
 After exposure in the jar 33*0 
 
 Difference = milligrammes of lime .... 6*0 
 
 Multiply by factor ....... '795 
 
 4-770=totaI c.c.'g 
 of CO2 in jar 
 Capacity of jar ...... =4385 
 
 Deduct 60 c.c. for space occupied by Hme water 60 
 
 Net capacity . ^4325 c.c. or 
 
 4-325 litres. 
 Then 4-770h-4-325 = 1'103 of CO. per litre or volumes per 1000. 
 
AIR 25 
 
 The factor '795 is obtained as follows. The milligrammes of CO2 are ob- 
 tained by calculating from the ratio of the equivalents of lime and carbon 
 dioxide. 
 
 CaO CO2 Mgm of CaO Mgm of CO, 
 
 66 : 44 :: a : x; 
 
 44 
 
 therefore x=a x --. 
 
 06 
 
 As 1 c.c. of CO2 at 32° F. weighs 1-9767 milligramme, the ratio between 
 
 volume and weight is =-506. 
 
 "" 1-9767 
 
 Therefore a: X'506=c.c. of CO^,. As GO c.c. of lime water were put into 
 
 the jar and only 30 c.c. taken, the result must be multiplied by 2. Therefore 
 
 we have ^^ x-506 x2=-795. 
 56 
 
 Corrections for temperature must be made if this deviates materially from 
 82° F., this being the temperature at which all gases are measured. If the 
 temperature of the air-space we propose to examine be above this, the air 
 is expanded, and we shall be operating on a smaller quantity by weight than 
 at the standard temperature. If, on the contrary, it is below 32° F., we 
 have a larger quantity of air to deal with, and an addition or subtraction must 
 be made accordingly. This correction may be stated as 1 per cent, for every 
 5° F. above 32° F.; the factor -795 is only true for the temperature at 32° F. 
 For each degree of temperature there is an increase or diminution of "002 in 
 the volume of air, i.e. "2 per cent, or 2 per 1000 ; for example, 1 htre of air 
 at 32° F. = 1000 c.c. This will expand at 33° F. to 1002 c.c, and will con- 
 tract at 31° F. to 998 c.c. ; so that if we are working at a higher tempera- 
 ture we are taking up less air by weight in our jar, and if at lower 
 temperatures more air. If, therefore, the temperature is 5° F. above 32° F. 
 add 1 per cent., if below subtract 1 per cent, from the amount found. For 
 example, if the CO2 per 1000 volumes = -6433 at a temperature of 55° F., 
 then 55° - 32° = 23° /. 23 x '2 = 4-6 per cent, to be added ; that is, 100 
 volumes become 104-6 volumes when raised from 32° F. to 55° F., or 1 
 volume becomes 1-046. 
 
 Then : 1 : 1-046 : : -6433 : x, 
 
 or, 1-046 X -6433 = -6728 volume per 1000. 
 
 The correction for degrees Centigrade is -3665 per cent, for each degree. 
 Correction for pressure is also necessary when the experiment is made 
 much above sea-level, or when the barometer reads below the standard height 
 taken, as -^ inch of pressure causes a difference of -26 per cent. The stan- 
 dard height of the barometer for which all observations are corrected is 
 taken at 29-92 inches, or 760 mm. ; for example, if the experiment is made 
 when the barometer reads 29 inches, then 
 
 29 : 29-92 :: observed CO2 : corrected CO2 ; 
 
 or if the barometer reads 31 inches, 
 
 31 : 29-92 :: observed CO2 : corrected CO2. 
 
 Although this method for determining the CO2 in air does not give quite 
 accurate results, it is the most convenient for ordinary use, and sufficiently 
 accurate for all practical purposes. 
 
 Dr. Angus Smith has proposed a very simple process for determining ap- 
 proximately the amount of CO2 in any air-space. It is found that a certain 
 amount of carbon dioxide is required to cause a given volume of Kme water 
 to become turbid. Half an ounce of perfectly clear lime water when shaken. 
 
26 
 
 HYGIENE 
 
 with the air contained in a bottle of 20-63 oz. capacity does not become turbid 
 if the air in the bottle contains only 0-3 per 1000 of COo, but if 0-4 per 1000 be 
 present a white precipitate is produced. A bottle of 15*16 oz. capacity 
 does not render half an ounce of lime water turbid when the air contains 
 0-4 per 1000 of CO.,. 
 
 Taking this point of ' no precipitation ' (temperatm-e of the air at 32° F. 
 and pressure 29-92 inches) with half an ounce of hme water, which should 
 be satm-ated and clear, as the test point, and varying the bulk of the air 
 shaken with it, Dr. Smith arranged his process which gives results sufficiently 
 close for ordinary purposes. In the foUowuig table are given the results 
 of the determinations of the volume of air contauiing different percentages of 
 carbon dioxide, that half an ounce of lime water contaimng -0195 gramme 
 of lime will bear agitation with and give no turbidity. In the table 
 allowance is made for the space occupied by the half-ounce of lime water. 
 
 Size of 
 
 Size of bottle 
 
 Volume of air 
 
 Carbon 
 
 Size of 
 
 Size of bottle 
 
 Volume of air 
 
 Carbon 
 
 bottle in 
 
 in cubic 
 
 in cubic 
 
 dioxide in the 
 
 bottle in 
 
 in cubic 
 
 in cubic 
 
 dioxide in the 
 
 ounces 
 
 centimetres 
 
 centimetres 
 
 ail per cent. 
 
 ounces 
 
 centimetres 
 
 centimetres 
 
 air per cent. 
 
 20-63 
 
 684 
 
 671 
 
 -03 
 
 6-00 
 
 170 
 
 156 
 
 •11 
 
 15-60 
 
 443 
 
 428 
 
 •04 
 
 5-53 
 
 157 
 
 143 
 
 •12 
 
 12-58 
 
 356 
 
 342 
 
 •05 
 
 6-15 
 
 146 
 
 132 
 
 -13 
 
 10-57 
 
 299 
 
 285 
 
 •06 
 
 4-82 
 
 137 
 
 123 
 
 •14 
 
 9-13 
 
 259 
 
 245 
 
 •07 
 
 4-53 
 
 128 
 
 114 
 
 •15 
 
 8-05 
 
 228 
 
 214 
 
 •08 
 
 ' 3-52 
 
 100 
 
 86 
 
 •20 
 
 7-21 
 
 204 
 
 190 
 
 •09 
 
 292 
 
 83 
 
 69 
 
 •25 
 
 6-54 
 
 185 
 
 171 
 
 -10 
 
 i 2-51 
 
 1 
 
 71 
 
 57 
 
 •30 
 
 It is necessary that white glass-stoppered bottles should be used, and 
 of the best description. The lime water should be deHvered into the bottles 
 as rapidly as possible by means of a glass pipette measuring the exact 
 quantity. 
 
 2. Estimation ofOxidisable Substances in the Air. 
 
 To determine these a definite quantity of air is drawn through a solution 
 of permanganate of potassium of known strength, and the amount of unde- 
 composed permanganate observed by means of the standard solution of 
 oxalic acid, or part of the water through which the air has been drawn may 
 be used for the purposes of examination and the oxidisable matter in it be 
 determined by Tidy's process (see article on Water Analysis). This latter 
 process includes two determinations : viz. one finding the oxygen absorbed 
 in fifteen minutes and the other the amount taken up in three hours. The 
 experiments are carried on at a temperature of 80° F. 
 
 Carnelley and Mackie have proposed a modification of the permanganate 
 process, for which are claimed the advantages of rapidity and simplicity of 
 execution, as well as a higher probability that the organic matter is fully 
 absorbed. The solution used is of the N strength, of which 1 c.c. = -008 mgr. 
 of oxygen=-0056 c.c. of oxygen at 0° C. and 760 mm. It is usually kept of 
 
 strength and diluted as required, about 50 c.c. of dilute sulphuric acid (1 to 6) 
 
 10 
 
 N 
 
 being added to each litre of the weak solution. 
 
 The air is collected in large well-stoppered jars of about 3*5 litres capacity. 
 Before use the jars are drained and the contained air extracted by pumping 
 with a small bellows and allowing the air to be examined to flow in : 50 c.c. of 
 the standard permanganate are next run into the jar, which is then tightly 
 stoppered and well shaken up for at least five minutes ; 25 c.c. of the per- 
 manganate are afterwards withdrawn by a pipette and placed in a glass 
 
AIB 27 
 
 cylinder for comparison. Both are next diluted up to about 150 c.c. with 
 distilled water and allowed to stand for ten minutes, after which the tints in 
 the two cylinders are compared. Standard solution is then run in from 
 a burette until the tints in both cylinders are of the same intensity ; usually 
 from |- to 6 c.c. are required. 
 
 The amount of solution added from the burette is a measure of the bleach- 
 ing effected by the known volume of air in half the permanganate employed. 
 This multiplied by 2 gives the total bleaching. 
 
 Example. — 25 c.c. of solution from a 3*5 litre jar in which 50 c.c. had been 
 used required 3 c.c. of the permanganate to bring it up to the standard, or 
 the whole 50 c.c. would have required 3x2 = 6 c.c. This represents the 
 number of c.c. of standard permanganate bleached by 3500 — 50=3450 c.c. of 
 
 air; consequently •——^=1"74 c.c. is the bleaching effected by 1 litre of air. 
 
 But 1 c.c. of standard permanganate solution="0056 c.c. of oxygen ; therefore 
 1-74 X '0056= '0097 c.c. of oxygen is required to oxidise the organic matter in 
 a litre of air, or 9*7 volumes of oxygen to oxidise the organic matter in 
 1,000,000 volumes of air. 
 
 3. Examinatio7i of the Free and of the Albuminoid Ammonia. 
 
 The estimation of the nitrogenous matter in the air is of importance, as 
 it is mostly derived from the dead and Uving matter existuig in the air, and 
 is useful for comparison with results obtained from pure air. The most 
 convenient plan is to draw the air through a series of wash bottles, each con- 
 taining 100 c.c. of pure distilled water, by means of an aspirator of known 
 capacity, so that the volume of air passing through may be measured ; five 
 bottles are generally used, and these are connected by indiarubber tubing. 
 "When a given quantity of air has passed through, the water in the several 
 bottles is mixed together, and the free and albuminoid ammonia determined. 
 The results are calculated in milligrammes per cubic metre. 
 
 The object of these processes is to get a measure of the nitrogenous 
 matter present ; both give useful information, but they are not always 
 applicable, as it is difficult to complete such an analysis on the spot and the 
 amount of apparatus required renders several consecutive determinations in 
 a series of rooms impossible. 
 
 4. Nitrous and Nitric Acids. 
 
 A part of the water through which the air has filtered may be used for 
 the determination of these acids. To estimate the quantity of nitrous acid 
 present Griess's method may be employed. 
 
 For the determination of the nitric acid the aluminium process (Schulze's 
 modified by Wanklyn and Chapman) is perhaps the simplest. 
 
 In these processes for the estimation of the organic matter in air the 
 quantity drawn through the water must be accurately measured by a pro- 
 perly arranged aspirator, and the results calculated as milligrammes per 
 cubic metre of air. 
 
 The presence or absence of sulpMiretted hydrogen may be determined 
 qualitatively by means of acetate of lead papers and ammonium sulphide by 
 paper dipped in nitro-prusside of sodium. 
 
 Ozone is detected by its action upon potassic iodide. Strips of paper 
 saturated with a solution containing starch and iodide of potassium, dried 
 and exposed to the air for a definite period, are supposed to indicate the 
 amount of ozone present. Ozone causes a blue tint, the depth of which is 
 taken as showing the amount according: to a standard scale of tints. 
 
28 HYGIENE 
 
 This is not a very reliable test, as nitrous acid and peroxide of hydrogen 
 give the same reaction ; hght, humidity, and temperature also vary the reac- 
 tion. 
 
 The hygrometric condition of the air is ascertained in various ways ; by 
 Daniell's hygrometer or Regnault's, which is somewhat similar in principle, 
 or by Dines' hygrometer (see article on Meteorology). In the army the wet 
 and dry bulb thermometers are used, and the relative humidity corresponding 
 to all ordinary readings of the wet and dry bulb thermometers are taken from 
 Glaisher's Tables. 
 
 Examination of Micro-organisms in Air. 
 
 In addition to the suspended matters found in air, already referred to, 
 micro-organisms are also present. The points of importance to note with 
 regard to them have reference to their number, growth, mode of development, 
 and cultivation in nutrient media. If air is drawn through Hesse's tubes, 
 or if plates covered with sterihsed nutrient gelatine are exposed to the air, 
 the aerial organisms are deposited on the surface of the gelatine, and cultiva- 
 tion gives rise to a colony which has a characteristic appearance. From 
 these colonies further cultivations may be made in tubes by inoculation, and 
 the process repeated as long as it may be deemed desirable. 
 
 Hesse has shown that when a room is left quiet the micro-organisms 
 settle dowTi and leave the air comparatively free from them. In the case of 
 dwelling-rooms, generally, micro-organisms decrease as cubic space increases. 
 One very important point has been already noticed, the relation of bacteria 
 to moulds in various kinds of air ; the purer the air becomes, the more 
 readily, as a general rule, do the bacteria and moulds become equal. The ex- 
 planation is that the moulds come mostly from the external air. When 
 the air of a room becomes very impure, the bacteria increase, while the 
 moulds remain unaffected. 
 
 It was also found that the stirring up of dust altered the ratio. The 
 moulds were little affected while the bacteria increased : the reverse is the 
 case when quiet is established, as the particles to which the bacteria are 
 attached settle more rapidly than the moulds ; this is due to the relative 
 lightness of the moulds. 
 
 The cultivation of bacteria in solid nutrient gelatine or in agar-agar, after 
 the manner of Koch, is the method generally adopted in air analyses, subject 
 to various modifications. Hesse adopts the following plan. A glass tube of 
 0'7 metre (28 inches) in length and "035 metre (nearly 1^ inches) in diameter 
 is carefully sterilised ; into this some nutrient gelatine is introduced in a 
 liquefied state and spread out over the whole of the inner surface of the tube 
 by turning it about on its own axis. One end of the tube is closed by an 
 indiarubber cap, with a small glass tube passing through its centre ; the 
 other end is furnished with two indiarubber caps, the inner one being 
 perforated ; all the portions of the apparatus have been previously sterilised. 
 The liquefied gelatine quickly solidifies and forms a thin layer over the 
 inside of the tube. The apparatus is set working by removing the outer 
 indiarubber cap, and aspirating a known quantity of air through the tube at 
 a slow rate (1 litre in three minutes). The germs present in the air sink down 
 and subsequently develop in the nutrient gelatine. 
 
 Dr. Percy Frankland recommends aspirating the air through a small 
 glass tube in which are two plugs of sterihsed glass-wool. When the air 
 is aspirated through this tube, the glass-wool retains the germs, and these 
 plugs are afterwards introduced into a flask containing melted nutrient 
 
AIB 29 
 
 gelatine and well shaken up. The gelatme solidifies on the sides of the flask, 
 and the colonies can be examined by means of a lens through the glass. 
 Powdered sugar may be used in place of the glass-wool, but this latter mixes 
 so intimately with the gelatine that it is found not to interfere in any way 
 with the growth or perception of the colonies. The gelatine may also be 
 poured on glass plates in the ordinary way, instead of being allowed to sohdify 
 within the flask, and if further cultivations are carried on this is by far the 
 most convenient plan. 
 
 Dr. Greenleaf Tucker, of Boston, U.S.A., prefers using granulated sugar in 
 a very narrow tube. 
 
 Dr. Petri employs calcined sand as a filter in grains of "25 to -5 milli- 
 metre in size ; there are two such filters, each 3 centimetres in length, kept 
 in position by small wire caps. After the air has been drawn through the 
 sand is poured on to a glass plate, over which liquefied gelatine is then run, 
 and development takes place as in ordinary plate cultivations. It is impossible 
 to say at present which of these methods is the best. 
 
 The method of cultivation adopted at Netley is that introduced by E. 
 Koch : this consists of cultivation in sohd nutrient gelatine.^ Glass-wool 
 carefully removed from the tubes by a platinum needle, which has been pre- 
 viously heated to redness, is introduced into a test tube containing Hquefied 
 nutrient gelatine. This is then poured into one of Petri's small dishes (which 
 has been sterilised) and in a few minutes becomes solid. The micro- 
 organisms adhering to the glass-wool, if any, being fixed in a solid medium 
 will grow in the places where they have been fixed, and in this way colonies 
 of bacteria are developed, which can be differentiated from one another by 
 various peculiarities of growth. 
 
 The enumeration of the colonies that grow on gelatine plates has been carried 
 out by Miquel, by Koch, by isher, and by Percy Frankland, as well as many 
 other observers. The numbers are generally stated as per cubic metre of 
 air, each colony resulting from, and therefore indicating the presence of so 
 many separate forms. It has been shown, however, that the micro-organisms 
 vary enormously in number according to locality, temperature, season of the 
 year, and even time of day. One point that appears to be demonstrated is that 
 the smaller the number of organisms present the purer is the air supply ; the 
 numbers diminish rapidly with elevation above the ground level, and after rain. 
 
 Dr. A. M. Davies,^ who has devoted much time to this subject, advocates 
 a systematic description of the naked- eye characters of the different kinds of 
 colonies as being likely to afford valuable indications, and has suggested that 
 they should be described under the following heads. The distinction between 
 Cocci and Bacilli should be noted : then — 
 
 A. Those that Uquefy gelatine : 
 
 Their colour, presence or absence of a deposit and its colour, presence or 
 absence of areola round the hquefied part &c. 
 
 B. Those that do not liquefy the gelatine : 
 
 I. Colour, Generally whitish or yellowish ; it may be milky or translucent 
 (colour absent) ; pale, bright or deep yellow, &c. 
 
 II. Form. Circular, nearly circular, oval or more or less irregular, 
 branching, &c. 
 
 "' Prepared by extracting half a kilogramme (about 1 lb.) of beef, finely chopped up, with 
 one litre (1| pint) of water, with the addition of 10 grammes peptonum siccum, 5 
 grammes of common salt, and 100 grammes of gelatine, rendered very slightly alkaUne 
 with carbonate of sodium, filtered and sterilised by successive boilings. A perfectly clean 
 and transparent medium should result, solid at ordinary temperatures. This is kept in 
 test tubes, about one quarter full, closed with sterilised cotton-wool. 
 
 - Army Medical De^artme7it Beports, vol. xxx. p. 348. 
 
30 HYGIENE 
 
 III. Disposition. The colonies may be raised above tlie surface of the 
 gelatine, or they may be flat, or excavated in its substance, or cup-shaped. 
 
 IV. Surface. This may be either moist or dry, shining or dull, or waxy- 
 looking, &c. 
 
 V. Peculiarities. Such as granular appearance, hard or soft, &c. 
 
 If to this be added a description of the character of the growth in different 
 media and on potato, as well as the microscopic examination of the organisms, 
 we have all the information, short of inoculation experiments into living 
 animals, at present at our disposal from which to draw conclusions. It 
 certainly appears advisable to supplement any chemical examination of 
 an air-space by an investigation of the characters of the micro-organisms 
 present, in the hope that as our knowledge increases in this branch of 
 scientific research we may obtaui in this direction that mformation which, 
 in many cases, chemical analysis seems incapable of furnishing. 
 
WARMING AND VENTILATION 
 
 BY 
 
 W. N. SHAW, F.E.S. 
 
 LECTURER ON EXPERIMENTAL PHYSICS IN THE UNIVERSITY OF CAMBRIDGE 
 
33 
 
 INTEODUCTION 
 
 1. The closely related subjects of warming and ventilation may be re- 
 garded mainly as special technical departments of the sciences of heat, 
 hydraulics, and pneumatics. In dealing with problems relating to the 
 warming of buildings we have primarily to consider the production and 
 distribution of heat, and with problems in ventilation we are primarily con- 
 cerned with the mechanical processes involved in the motion of air. But the 
 continuous production of heat requires, as a rule, a continuous supply, of air, 
 which may be used for the purposes of ventilation ; in fact, heat is one of the 
 most important agents in ventilation, and the distribution of heat is frequently 
 dependent upon the distribution of heated air or heated water. Moreover, 
 the air which is supplied for ventilation often requires to be warmed. It is 
 not therefore practicable to consider the two subjects separately, but, with the 
 view of arranging the facts with which we have to deal, in some sort of order, 
 we shall first consider some of the most important points in the production 
 and measurement of heat and the effects produced by heat upon the physical 
 properties of air and other bodies, and then call attention to some of the 
 fundamental phenomena observed in the motion of air and other fluids before 
 proceeding to the discussion of actual problems in warming or ventilation, 
 or both combined. 
 
 2. Production and Mecosurement of Heat. — Heat for the purposes of warm- 
 ing is mainly due to combustion, which is a name given to the chemical action 
 which occurs when the oxygen of the air combines with such substances as 
 wood, coal, oil, or coal gas. Such substances are known as fuels, of which 
 there are many kinds, solid, liquid, or gaseous. The principal constituents 
 of fuels are the solid element carbon and the gaseous element hydrogen, and 
 the various chemical combinations of those two elements. Under certain 
 conditions the fuel unites with the oxygen of the air, the carbon becoming 
 oxidised to form the heavy gas known as carbonic acid, while the hydrogen 
 also becomes oxidised and forms water ; the oxidation is attended with the 
 evolution of a large quantity of heat. Thus every pound of carbon in burning 
 forms 3'7 lbs. of carbonic acid gas and gives out enough heat to raise the 
 temperature of 87 lbs. of water from 62° F. to the boiling point (212° F.), 
 while every pound of hydrogen (190 cu. ft.) produces 9 lbs. of water, and in 
 doing so gives out heat enough to raise 417 lbs. of water through the range 
 of temperature from 62° F. to the boiling point. As carbon and hydrogen 
 form the main constituents of fuel, carbonic acid gas and water are the 
 principal products of combustion, and these must be continually got rid of, 
 and air continually supplied to furnish a continuous supply of oxygen, if the 
 combustion is to be maintained. At the high temperature produced by the 
 combustion, the water is produced as vapour and passes away with the car- 
 bonic acid gas ; it may be diffused through the air, or part of it may be 
 condensed if the products of combustion be sufficiently cooled before they 
 are allowed to diffuse into the outside air. 
 
 There is another method of producing heat artificially which, though not 
 used practically, is of very great scientific importance, and is here referred to 
 
 VOL. I. D 
 
34 HYGIENE 
 
 especially on account of its connexion -with the converse process, the 
 artificial production of cold, or, to speak more correctly, the artificial 
 abstraction of heat from bodies which are themselves cold in comparison 
 with those suiTOunding them. The method in question is the production of 
 heat by friction. It is a familiar process which needs no description, but 
 what is important to our subject is that the amount of heat which can be 
 produced by the process is numerically related in a perfectly definite manner 
 to the friction which produces it and the distance through which the rubbing 
 surfaces are made to slide. If we consider a large flat mass lying on a 
 horizontal table, and dragged along the table by a weight hanging from a 
 string passing over a pulley at the end of the table, and if we suppose that 
 the weight required to keep the sliding motion just going is, say, 100 lbs., 
 then, by experiments differing in detail, but not in principle, from the ima- 
 ginary one here described, it has been shown that for every foot which the 
 100 lbs. falls a certain quantity of heat is produced by the friction and divided 
 between the table and the mass upon it. The amount of heat so produced 
 does not seem large when compared with the amount of heat produced in 
 combustion ; for the numerical experiments show that the 100 lbs. would 
 have to fall through 7'72 feet in order to produce heat enough to raise the 
 temperature of a pound of water one degree Fahrenheit, or through 1158 
 feet to raise a pound of water from 62° F. to the boiling point ; a pound of coal 
 would have to fall under similar circumstances through upwards of 2000 
 miles to produce the same amount of heat by friction as would be produced 
 by its combustion. The falling weight is said to lose energy in falling, and 
 the heat produced between the table and its moving load is the equivalent 
 and representative of the energy so lost. The energy of bodies may take 
 many forms ; that of a raised weight is one form only ; an equal amount 
 might have been furnished by stopping a mass moving with a sufficient 
 velocity or by allowing a compressed spring of suitable dimensions to resume 
 its natural shape. 
 
 Thus heat must be considered as one of the many forms of energy and 
 may therefore be measured as energy is measured. The most common way 
 of measuring a given amount of energy is to estimate how much ' work ' it 
 could do. If, for instance, it could be shown that the energy in question 
 would Hft a 10 lb. weight through a vertical height of 50 feet, or, what is 
 precisely equivalent, a 20 lb. weight through a height of 25 feet, the amomit 
 of the energy would be 10 x 50, or 20 x 25, i.e. 500 foot-pounds. In like 
 manner we may express every quantity of heat as so many foot-pounds. This 
 would be the most scientific way of expressing quantities of heat, but it is for 
 several reasons not practicable to employ the actual conversion of heat into 
 work to furnish a working method of measmdng heat. It is a well-kno^^1l 
 fact that if we were to set about measuring the heat produced by the burning 
 of, say, a pound of coal by finding out what work it could be made to do in 
 lifting weights with any engine or apparatus at our disposal, at least nine- 
 tenths of the heat would escape without recording itself as work, though the 
 total reconversion of the remaining one-tenth into heat could be easily 
 managed. "While, therefore, we should not lose sight of the fact that heat and 
 work, or energy, are, in one sense, equivalent terms, and that when work is 
 done by heat a certain definite amount of heat necessarily disappears, and vice 
 versa, yet we require some more directly applicable way of measuring heat 
 than by finding its theoretical work-equivalent. The practical method, as 
 hinted in the numerical examples given above, is to find the number of pounds 
 of water that can be raised in temperature fi'om 32° to 33° F. by the amount of 
 heat to be measured. We shall call the amount of heat necessary to raise 
 
WARMING AND VENTILATION 35 
 
 one pound of water through that range of temperature the lb. F. unit of heat, 
 or British thermal unit. As the result of many experiments it has been 
 shown that the amount of heat necessary to raise the temperature of 1 lb. 
 of water through any degree of the scale of temperature between 32° F. and 
 212° F. is, though not strictly, yet for all practical purposes, equal to the lb. F. 
 unit ; moreover it is not difficult to secure that all the heat developed, say, 
 by the burning of 1 lb. of coal shall be devoted to raising the temperature of 
 a weighed quantity of water, and hence we may express that heat in lb. F. 
 units by the numerical product of tlie number of pounds of water heated 
 and the number of Fahrenheit degrees through which its temperature is 
 raised. V 
 
 By a process similar in general principle to that here indicated, the 
 quantities of heat produced by the combustion of known weights of different 
 fuels have been measured. The quantities produced in the combustion of 
 one pound of the commoner fuels are given in a table on p. 122, and the same 
 table gives an estimate of the amount of heat that can be bought for a penny 
 in each case. The quantity of heat produced by the combustion of a fuel 
 of which the percentage composition is known can in general be approximately 
 calculated from the amounts produced in the burning of the several con- 
 stituents ; as these are mainly carbon and hydrogen, the most important data 
 required for the calculations are that the heat of combustion of one pound 
 of carbon is 13,000 lb. F. units, and that of one pound of hydrogen 62,500 
 such units. 
 
 3. Latent Heat. — As a general rule the communication of a quantity of 
 heat to a substance raises its temperature, but sometimes the effect of the 
 transference is to change the state of the substance without altering its 
 temperature. Thus every pound of ice, when it melts, absorbs 143 lb. F. 
 units of heat without any rise of temperature being produced, and the boiling 
 away of a pound of water into steam in the air is only secured by trans- 
 ferring to the water 966 lb. F. units of heat, although the temperature of the 
 steam will be the same as that of the water from which it is produced. The 
 heat is then said to be rendered latent, and the amount of heat rendered 
 ' latent ' in the fusion or evaporation of 1 lb, of any substance will be called 
 the latent heat of fusion or evaporation, respectively, of the substance. Water 
 evaporates at all temperatures from surfaces exposed to the air unless the 
 air is already saturated with water vapour : this evaporation takes place 
 at the sacrifice of the latent heat, 966 lb. F. units,^ for each pound evaporated, 
 which if not drawn from a special supply must be furnished by reducing the 
 temperature of the water itself and the bodies in contact with it. On the 
 other hand, a cold substance in very moist air causes a condensation of the 
 water vapour and liberates the corresponding amount of latent heat. 
 
 ' Other practical units adopted for the measurement of quantities of heat are as 
 follows : — 
 
 The ' calorie ' is the amount of heat required to raise the temperature of 1 kilogramme 
 of water from 0° C. to 1° C. 
 
 The 'therm,' suggested by a committee of the British Association (B. A. Report 1888, 
 p. 56), is the amount of heat required to raise the temperature of 1 gramme of water from 
 0° C. to 1° C. 
 
 4200 Joules = 1 calorie = 1000 therms = 3-968 lb. F. units. 
 772 foot-pounds = 1 lb. F. unit = -252 calorie = 252 therms. 
 
 2 The latent heat of evaporation of water varies slightly with the temperatme. It may 
 be approximately expressed by the relation L = 1092 - 0-7 (T - 32°) = 966 - 07 (T - 212°), 
 L being the latent heat and T the temperature Fahrenheit. (Eankine, Steam Engine, 
 § 214.) 
 
 d2 
 
iJ6 HYGIENE 
 
 4, Specific Heat. — The amounts of lieat which can be stoi-ed in equal 
 weights of different substances by raising their temperatures through the 
 same range are very different. The number of lb. F. units of heat required 
 to raise the temperature of 1 lb. of a substance through 1° F. is called its 
 specific heat. We give here a table of the specific heats of some substances 
 by which it will be easy to compare the efficiency of different substances for 
 the storage of heat. 
 
 Table I. — Specific Heaxs 
 
 Number of lb. F. units 
 required to raiso tlie 
 temperature of 1 lb. 
 Substance through 1° F. 
 
 Water 1 
 
 Ice -504 
 
 Steam (ai constant pressure) -480 
 
 „ (at constant volume) -STO 
 
 Copper -0951 
 
 Iron -114 
 
 Brass -0939 
 
 Fire brick -i 
 
 Coal and Coke about -2 
 
 Wood . . J 
 
 Air (when the volume is kept constant) . . . 0-169 
 „ (allowed to expand freely) 0-238 
 
 From this table it appears that, weight for weight, water will absorb much 
 more heat for the same rise of temperature than any of the other substances, 
 and when the latent heat of evaporation is added we find that by carrying 
 1 lb. of steam at 212° F. into a room, and there cooling it to water at 60°, 
 we should have transferred 1118 lb. F. units of heat, whereas, if 1 lb. of air 
 were similarly dealt with, the heat got out of it would have been a very much 
 smaller amount, namely, 36 lb. F. units. If water at 212° F. had been used, 
 instead of steam at the same or slightly higher temperature, 152 units would 
 have been developed, or about four times as much as for the same toeight of air. 
 "When it is remembered that in carrying heat from place to place by carrying 
 heated bodies, the loss of heat during the carriage is greater the higher the 
 temperature to which the heated bodies are raised (if the exposed surfaces 
 are the same), the comparative economy secured by using water instead of 
 air for the purpose will be sufficiently obvious ; and yet more so when we con- 
 sider that the volume occupied by equal weights of air and water at 212° F. 
 is in the ratio of about 1000 to 1, and the air will therefore expose nearly 
 100 times as great a surface for the same weight. 
 
 5. Distribution of Heat. — If a number or ' system ' of bodies at different 
 temperatures be left to themselves, the distribution of temperature will 
 gradually become uniform by the passage of heat from the hotter to the 
 colder parts of the system. The process of distribution of the heat in any 
 special case would ]probably be a very complicated one, but it may be analysed 
 as follows : — 
 
 i. Distribution by Conduction. — The hot portions will communicate 
 heat to the cooler layers in contact with them, and these in their turn will 
 pass on heat to the still cooler layers adjacent, taking more heat from the 
 hotter. In this way a slope of temperature will be established from the 
 hottest to the coldest portions, and the rate of transmission of the heat will 
 depend on the steepness of this slope of temperature. The process of dis- 
 tribution in this manner is known as conduction of heat. As the tempera- 
 tures of the different portions become more nearly equal, the slope of 
 temperature becomes less, and the How of heat consequently slower. With 
 
WARMING AND VENTILATION 
 
 y,7 
 
 the same slope of temperature equally thick layers of different substances 
 allow widely different quantities of heat to flow through them in equal times. 
 Good conductors are such as allow a rapid flow of heat through them, and 
 conspicuous amongst all substances in this respect are the metals, particu- 
 larly copper. Bad conductors, on the other hand, under similar circum- 
 stances, allow only a comparatively slow flow of heat through them. A 
 perfect non-conductor Avould entirely prevent the flow, but no such substance 
 is known to exist. If it were not for its fluid mobility, air would be a very 
 good heat insulator, and air prevented from moving about by some substance 
 such as cotton wool or swan's-down is very efficient for preventing the 
 escape of heat from hot bodies. Wood, glass, and asbestos are also very 
 useful, as are, too, indiarubber, wool, felt, fossil meal (Kieselguhr), slag- wool, 
 glass-wool, paper. The loss of heat from steam boilers is now generally 
 considerably diminished by coating them with a thick layer of some badly 
 conducting composition. 
 
 In order to compare the properties of various substances with regard to 
 their power of conducting heat we give here a table of conductivities or con- 
 ducting powers. The numbers in the second column show the amount of 
 heat in lb. F. units which would pass per hour through an area of one square 
 foot of a layer of the substance one inch thick if the two surfaces of the layer 
 differed in temperature by 1° F. Except for copper and iron the data are 
 very uncertain. On this subject authorities differ very widely. See Everett's 
 ' Units and Physical Constants,' §§ 126-141 ; and Sir W. Thomson, art. 
 ' Heat,' § 75, Encycl. Brit. (9th ed.) The amount of heat, H, flowing per hour 
 through an area, A square feet, of a slab I inches thick of a substance whose 
 conducting power is K when the difference of temperature is t° F. may be 
 
 calculated by the formula H = K -y-. 
 
 Such a formula may often be usefully employed to calculate the loss of 
 heat through walls or windows with a view to determining the quantity of 
 heat that must be supplied to balance such losses, and so keep up the internal 
 temperature of a building. See Box's Heat, p. 212. 
 
 Conducting power 
 in lb. P. units. (K) 
 
 Substance 
 
 Conducting power 
 in lb. P. units. (K) 
 
 . 3225 
 
 Water . 
 
 . 5-82 
 
 
 477-4 
 
 Air . . 
 
 . . -16 
 
 
 113? 
 
 Wool . 
 
 •32 
 
 
 16? 
 
 Fossil meal . 
 
 ? 
 
 
 4-3 
 
 Glass . 
 
 . 6-6 
 
 
 5-1 
 
 Eider-down . 
 
 . -31 
 
 
 3-79 
 
 Slag-wool 
 
 . -314 
 
 es) 
 
 1-70 
 
 Asbestos fibre 
 
 ? 
 
 Table II. — Conducting Powers 
 
 Substance 
 Copper 
 Iron 
 Lead 
 Slate 
 Brick 
 Firebrick 
 Asphalt 
 Oak (across the fibres) 
 
 ii. Distribution hy Badiation. — When a hot and a cold body are separated 
 only by certain substances which may be called transparent for heat, the 
 heat passes directly (in all probability in the form of waves similar to waves 
 of light) from the hot to the cold body, only a very small fraction being 
 spent in heating the intervening medium. The form of energy which the 
 heat assumes on its passage through a medium in this manner is called 
 ' radiation.' 
 
 All bodies surrounded by transparent media are always radiating heat 
 which may be absorbed or transmitted or reflected by the bodies upon which 
 it falls, precisely in the same way as light. 
 
 Indeed, physically speaking, light is but the name given to a special form 
 
38 HYGIENE 
 
 of heat-radiation which the construction of our eyes enables us to see. If it 
 falls upon an opaque body some is reflected, and by that we see the body, 
 but some is absorbed and raises the temperature of the body. Of the energy 
 that comes from a glowing body only a small part is visible, the greater part 
 bemg only appreciable by its raising the temperature of the body by which it 
 is absorbed. All bodies surrounded by transparent substances radiate heat 
 at all temperatures, the amount of heat radiated per second depending upon 
 the temperature in some way which is not yet fully understood. It depends, 
 however, also on the nature of the body and of its surface. A polished 
 metallic surface radiates very little heat as compared with a dull surface, the 
 amount of radiation from polished metal being about one-fifth of that from 
 lampblack, white lead, or any other dull surface at the same temperature. 
 
 The power of a body to absorb radiation is the same as its power of 
 radiating at the same temperature ; so if two bodies radiate heat, each to the 
 other, the transfer of heat depends on the difference of the amount radiated 
 by the two, and this will be affected by [a) the nature and surface of the 
 radiating body ; (&) the nature and surface of the absorbing body ; (c) the 
 difference of temperature between the two. Speaking generally, we may 
 say that good radiators are good absorbers ; good reflectors are bad radiators ; 
 transparent bodies are bad radiators. 
 
 The most familiar and important instance of the transfer of heat by radia- 
 tion is furnished by the sun, whose rays supply us with heat that has passed, 
 as the motion of extremely minute waves, through tbe ninety millions of 
 miles of transparent space that separate the sun from the earth, and through 
 the earth's transparent atmosphere, passing on its way through strata of air 
 that must be colder than the coldest mountain-tops. The radiation produces 
 no sense of warmth until it is converted into heat in the bodies upon which 
 the rays fall ; and from what has been said above it will be clear that a body 
 in the sun's rays may be quite cool if it be transparent, and if opaque its 
 temperature will rise, least if it have a highly polished surface and most il 
 the surface be dull, particularly so if it be dull black. It is a common enough 
 observation that the temperature of a thermometer which has its bulb coated 
 Avith lampblack and enclosed in an exlaausted glass vessel will rise on ex- 
 posure to the sun's rays to a point not far short of the boiling point of water. 
 
 Of the radiation which falls upon a polished surface nearly all is reflected 
 like light from a mirror : from a polished surface of silver 97 per cent, is so 
 reflected ; from a polished steel surface 83 per cent. If the surface is coated 
 with lampblack nearly the whole is absorbed and applied to raising the 
 temperature of the lampblack and the substances in contact with it ; but if 
 the surface be dull white a great part is diffusely reflected, that is, the radia- 
 tion is dispersed in all directions in the transparent medium, as though the 
 white surface were itself rendered very hot by the radiation. In this way 
 even a snow-field by diffuse reflection of the sun's rays may produce the 
 same effect as if the snow itself were at a very high temperature. If the 
 surface upon which the radiation falls is in any degree transparent, the radia- 
 tion is partly transmitted, partly reflected from the polished transparent 
 surface, partly diffusely reflected and the remainder absorbed. 
 
 Different substances exhibit remarkable differences in transparency to 
 radiation. Air if dry is extremely transparent, but, according to Tyndall, the 
 water vapour though invisible causes considerable opacity, so that moist air 
 becomes itself heated when heat is radiated through it. Of other transparent 
 substances, glass is the only one which is of great interest to us, and its pro- 
 perties in regard to radiation are exceptional. A plate with a thickness of 
 "37 inch absorbs half the energy of radiation which falls upon it. transmitting 
 
WABMING AND VENTILATION 39 
 
 the other half ; but the half which is absorbed consists almost entirely of 
 energy in an invisible form, or dark heat, as it is called ; so that the apparent 
 effect of glass in shutting out light is very small indeed, though a thick plate 
 is very effective in screening the heat of the sun or fire. 
 
 iii. Distribution by Convection. — The processes of distribution of heat by 
 conduction and radiation are frequently rendered much more rapid by the 
 motion of the liquids and gases set up by inequalities of temperature. If air 
 is in contact with a hot surface, it becomes itself heated by conduction, and 
 therefore specifically lighter than the surrounding cooler portions ; the heated 
 air accordingly rises, being pushed upwards by the sinking of the colder air. 
 A steep slope of temperature may thus be maintained and the flow of heat from 
 the hot body greatly accelerated. This process also takes place when one part 
 of a liquid ^ is warmed ; but as any liquid is specifically so much heavier than 
 air the distribution by convection is not so easily observed in liquids as in 
 gases ; but it always exists in fluids of both kinds as long as the hotter por- 
 tion of the fluid is specifically lighter than the cooler portion above it. 
 
 The convection currents in any closed space, as, for instance, an ordinary 
 room, are in consequence enormously complicated. At every part of the room 
 where the air is being heated or cooled, no matter how slightly, unless the 
 heating is at the ceiling and the cooling at the floor, convection currents are 
 produced. If there is a fire in the room, some of the heat of the fire passes 
 across the room by radiation in direct lines to the walls, floor, and furniture 
 without directly heating the air to any considerable extent. The surfaces 
 upon which it falls absorb part of the heat, communicate heat to the air by 
 conduction in consequence, and cause upward convection currents ; other parts 
 of the heat are reflected either metallically, as by a polished surface, or 
 diffusely, as by a dull white surface, to other parts of the room, and cause 
 upward currents as before. On the other hand, the windows are probably 
 colder than the internal air in contact with them, and downward convection 
 
 ■ currents are the result. The sun's rays passing through windows and being 
 absorbed by the patch of floor or wall upon which they fall cause upward 
 convection currents. Every person in the room causes convection currents 
 by the heat conducted to the air in contact with his skin or clothes. It is 
 easy to get a wind-vane sufficiently sensitive to show the convection current 
 due to the heat of the hand. The air, therefore, of a room with a fire in it 
 on a cold day is in a most complicated state of turmoil, as an examination of 
 the motes in a sunbeam or the beam of an electric lamp will show. 
 
 ■ Convection currents produced by fires in shafts and chimneys are the agents 
 depended upon very largely for causing the change of air which constitutes 
 ventilation in mines and elsewhere, and success in ventilation depends 
 mainly upon an accurate knowledge of the convection currents produced by 
 all the sources of heat concerned, whether expressly employed for the 
 purposes of ventilation or not. 
 
 The convection currents produced by the human body in an atmosphere 
 colder than itself, while they carry off a good deal of heat, are incidentally of 
 great advantage, as they provide the body with a supply of fresh air. In 
 climates where the temperature of the surrounding air is so nearly that of 
 the body (98° F.) that this natural replacement of air does not take place, an 
 artificial commotion is necessary, and is usually made by means of fans worked 
 by hand. 
 
 Illustrations of the great complexity of the convection currents in a room 
 may easily be obtained by observing the rapidity and the uniformity of the 
 > distribution of odours arising from Hquids with strong smell, or from tobacco 
 ' Except water for the range of temperature between 32° F. and 39° P. 
 
40 HYGIENE 
 
 smoke. The distribution of the smell is accomplished almost entirely by 
 convection, the direct efi'ect of diflusion being small in the time required for 
 the approximately iiniform distribution by convection. 
 
 Hardly less important to our subject is the convection of heat in liquids 
 on which the distribution of heat by hot water pipes depends, and the 
 comparative uniformity of distribution of temperature in large masses of 
 water is to be referred mainly to the same cause. The principles of the 
 action of convection in. liquids and in gases are quite identical, the differences 
 in detail arising from the relatively greater mass of the liquid. The processes 
 of convection of heat by water may therefore be very profitably used to 
 furnish analogues in ventilation problems. 
 
 0. From what has been already said, it will be seen that rapidity or slow- 
 ness of fall of temperature, or rate of cooling, of a hot body surrounded by 
 cooler ones depends upon a number of conditions which must be regarded in 
 designing heating apparatus for special circumstances. In order that a 
 body may cool as rapidly as possible, its specific heat should be small, it 
 should be a good conductor, and surrounded by cold air with freedom of 
 motion, and its surface should be such as to produce the greatest possible 
 radiation of heat. An iron room, painted dead black, on a cold clear night, 
 would probably offer the most instructive example of rapidity of cooling, and 
 conversely, in the sun's rays it would become most rapidly heated. When 
 we desire to provide for the health and comfort of the inmates of a building,, 
 rapid changes of temperature are generallyto be avoided, if possible, andaroom 
 with thick walls of brick (whose specific heat is high) surrounded by a second 
 wall with an air-space between, and painted white outside, with all windows 
 double glazed, and a thick thatched roof or double roof, would satisfy the 
 conditions required for maintaining an equable temperature, and would form a 
 striking contrast to the case of the iron room previously described. On a small 
 scale, the insulation of heat is carried to very great perfection in a Norwegian 
 cooking stove, which consists of a wooden box cased inside with thick layers 
 of felt and having a close fitted felted lid. The hot meats are kept in tins 
 which fit closely to the felt, so that there is no air circulation. The tem- 
 perature may be so kept up by the heat insulation that the process of cooking 
 can go on for some considerable time. Thus a can of water at 185° F. 
 placed in a Norwegian stove required twenty-nine hours for its temperature 
 to fall to 104° F., the air outside the box being at 68° F. ; whereas the tem- 
 perature of the same can exposed in a room fell through the same range in . 
 seven hours, even though the outside air was slightly warmer. It thus 
 appears that the loss of heat may, to a considerable extent, be prevented by 
 suitable arrangements. 
 
 The economy of fuel by the prevention of loss of heat from houses is 
 a department of our subject which has not received sufficient attention from 
 architects and builders, or owners. There are, indeed, some causes of loss 
 of heat which it is not desirable to reduce beyond certain limits. A great 
 part of the heat of an open fire passes up the chimney with the products of 
 combustion, but a considerable part of this is effective in producing the 
 necessary ventilation, and is not, therefore, to be regarded as wasted, and 
 the fireplaces can be so arranged that the waste from this cause is as small 
 as is consistent with the adequate efficiency of the chimney for the purposes 
 of ventilation. On the other hand, the heat lost by conduction through 
 outside walls and window-panes is merely wasted, and has to be made up by 
 an increase in the quantity of fuel consumed, if the rooms are to be kept 
 sufficiently warmed. And, further, permanently damp walls are a continual 
 cause of expense in fuel, for they imply a continual evaporation of water ■ 
 
WABMING AND VENTILATION 41 
 
 from their surface, and every pound of Avater so evaporated from the walls of 
 a room means, with an ordinary grate, the burning of an extra pound of 
 coal. This is also sheer waste of heat, and is now prevented in the bettor- 
 class houses by interposing an efficient damp-course, which prevents the water 
 passing upward from the ground ; but it generally goes on uninterruptedly 
 in smaller houses, although the increase in the initial outlay need not be 
 large, and the economy of fuel is of real importance to the tenants. 
 
 The loss by conduction through the walls and windows is not so cheaply 
 remedied. Double outside walls with an air-space between them and double 
 glazed windows would, no doubt, involve greater expense than would be 
 made up for by the economy of fuel that would result from their use, and 
 they are therefore only introduced where an equable temperature is of more 
 importance than economy in building. But more might be done than at 
 present in placing the chimney flues of houses so that more of the heat that 
 passes through their sides would be utilised in warming parts of the house 
 instead of the external air. Wooden shutters closed at night would help to 
 prevent the wasteful loss of heat by conduction through the glass panes. 
 There is, no doubt, a general prejudice against such insulation of heat, as 
 we have been used for so long to rely upon the crevices of the vdndows for 
 the supply of fresh air for ventilation ; and the ventilation is even then so 
 inadequate that we have acquired the habit of ventilating a room when it is 
 not being used in order that the insufficiency of ventilation when in use may 
 not become unendurable, and we are unwilling to interfere with our small 
 air supply. But the loss of heat by conduction in no way helps the ventila- 
 tion, and might be prevented with a thoroughly good conscience if inde- 
 pendent inlets were provided for the purposes of ventilation. 
 
 PHYSICAL PEOPEETIES OF AIR 
 
 7. The object of ventilation maybe stated in general terms to be the con- 
 tinuous replacement of the vitiated air in a nearly closed space by ' fresh ' air. 
 It is generally considered sufficient to draw the supply of air from any position 
 external to the building to be ventilated. But air is a mixture of gases, and 
 may contain many gaseous compounds as impurity ; on the other hand, the 
 mixing of air in open places, even m towns, is so rapid that there is no very 
 great difference in the composition of the air drawn from different locahties, 
 unless there is some special local source of contamination that alters the 
 character of the supply ; thus a more definite meaning is attributable to the 
 terms * air ' and ' fresh air ' than would at first seem likely. 
 
 Fresh air we may take to be a mixture of gases containing 20*96 per 
 cent, by volume of oxygen and 79 per cent, of nitrogen, with -04 per cent, (by 
 volume) of carbonic acid gas, besides a quantity of aqueous vapour which 
 varies in temperate climates between 0*5 grain and 20 grains per cubic foot 
 of air, according to circumstances, small traces of ozone, and gaseous 
 impurities of extremely minute amount. Any specimen of air contains also 
 a very large number of solid particles mechanically suspended, the actual 
 number in a cubic inch varying with the locality and the state of the 
 weather. 
 
 8. The weight of a cubic foot of air rendered perfectly dry by artificial 
 means varies with the barometric pressure and with the temperature. 
 When the pressure is equivalent to that of 30 inches of mercury, and the 
 temperature is 32° F., the weight of a cubic foot, or density, of dry air is 
 666'9 grains ; enough of such air to fill a room of 1000 cubic feet capacity 
 
42 HYGIENE 
 
 would consequently weigli 81 lbs., or nearly two-thirds of a hundredweight, 
 so that the weights to be moved in ventilation are not inconsiderable. 
 
 So long as the temperature remains the same the density is proportional 
 to the pressure, so that a fall of the barometer amounting to one inch 
 diminishes the density of the air by about one-thirtieth part. This change of 
 barometric pressure may arise from ordinary meteorological changes or in 
 consequence of the air being raised to a height of 900 feet above the ground 
 level. We may express the law relating to the variation of the density of 
 air with the pressure, considering a specific mass of air, by saying that the 
 volume of the mass of air is inversely proportional to the pressure. 
 
 When the pressure is kept constant and the temperature changes, the 
 density likewise changes, but always so that the density is inversely pro- 
 portional to the number of Fahrenheit degrees in the temperature with 459 
 added ; thus, increasing the temperature from the freezing point (82° F.) to 
 the boiling point (212° F.), while the pressure remains at 30 inches, will 
 change the density from 566-9 grains per cubic foot to A , where 
 
 ^='^^^^459-^212' 
 and in a similar manner the density of dry air at any other temperature 
 may be calculated. Considering, again, a specific mass of air, the effect of a 
 rise of temperatm-e may be expressed by saying that the volume of the air 
 will be increased by ^^i-fth part of the volume at 32° F. for every Fahrenheit 
 degree rise of temperature. 
 
 Combinuig these two effects of pressure and temperature, the density, A , 
 of dry air at any temperature, t° F., and any pressure, B inches, is given by 
 the formula 
 
 A = 566-9 X ^^ ^ f^l + f ^ grains per cubic foot . . . ' (1) 
 30 459 + t 
 
 9. Dynamical Cooling of Air. — One important case of variation of the 
 density and temperature of air under special conditions requires consideration ; 
 it may be set forth in the following way. Suppose that a room had been 
 hermetically closed when the barometer was at 30 in., and after it had fallen 
 to 29 in. a window was suddenly opened ; the air in the room would imme- 
 diately expand, part being forced out of the opening. This expansion would 
 be unaccompanied by any supply of heat, and the pushing of the external air 
 aside by the internal air escaping represents the performance of a considerable 
 amount of mechanical work. This work must be derived from some source, 
 and it would, in this case, be obtained by the conversion of some of the 
 heat contained in the expanding air into work, and would, therefore, be 
 necessarily accompanied by a diminution of temperature of the air. The 
 fall of temperature produced in this way is easily observed, and is known as 
 dynamical cooling of the air ; it would amount to nearly 5° F. in the instance 
 mentioned. The conversion of heat into work occurs whether the expansion 
 is rapid or slow, but in ordinary slow expansion the communication of heat 
 from surrounding bodies would be rapid enough to prevent the thermometer 
 falling any considerable extent. Compression of air produces a corresponding 
 heating effect. Whenever, therefore, expansion or compression of air takes 
 place suddenly, we cannot calculate the density by the formula (1), because 
 we do not know the change of temperature produced. It may, however, be 
 shown that, under the circumstances defined, the relation between the initial 
 and final pressures, and the initial and final densities, is expressed by the 
 equation 
 
WABMING AND VENTILATION 
 
 43 
 
 whereas, if the air had been supplied with heat rapidly enough to compensate 
 
 for the dynamical cooling, and so keep the temperature constant, the relation 
 
 would have been 
 
 £==.^ 
 p A'' 
 
 When the sudden change of pressure is given, the change of density 
 
 can be determined, and by aid of equation (1) the temperature of the 
 
 suddenly expanded air found. To exhibit more clearly the effect of dynamical 
 
 cooling the following table has been compiled. It shows the density and 
 
 temperature of air, of which the pressure has been reduced to 30 in. from 
 
 the number of inches in the first column without allowing any heat to be 
 
 communicated to it during the expansion. 
 
 Table III.— DyNAMicvii Cooling of Aie by Eeduction of Pkessuke 
 [Air originally at 60° F. Final pressure 30 inches.] 
 
 Initial pressure 
 
 
 
 Initial pressure 
 
 
 
 of the air in 
 
 Density after 
 
 Temperature 
 
 of the air in 
 
 Density after 
 
 Temperature 
 
 inches of 
 
 expansion 
 
 after expansion 
 
 Inches of 
 
 expansion 
 
 after expansion 
 
 mercury. 
 
 
 
 mercury. 
 
 
 
 
 Grs. per cu. ft. 
 
 
 
 Grrs. per cu. ft. 
 
 
 30 
 
 536-3 
 
 60-0 
 
 60 
 
 654-8 
 
 - 33-9 
 
 31 
 
 541-4 
 
 55-1 
 
 70 
 
 684-5 
 
 - 52-4 
 
 32 
 
 546-3 
 
 50-4 
 
 80 
 
 711-4 
 
 - 67-7 
 
 38 
 
 551-2 
 
 45-9 
 
 90 
 
 735-9 
 
 - 80-8 
 
 34 
 
 556-0 
 
 41-6 
 
 100 
 
 758-6 
 
 - 92-1 
 
 35 
 
 560-6 
 
 37-5 
 
 200 
 
 926-2 
 
 - 158-5 
 
 40 
 
 582-6 
 
 18-7 
 
 300 
 
 1040-9 
 
 -191-6 
 
 50 
 
 • 621-3 
 
 -11-0 
 
 
 
 
 Thus it will be seen that if a jet of air at 60° F. were blown into a room 
 by a pressure behind the jet of 6^ inches of mercury above the barometric 
 pressure of 30 inches, so that the pressure of the air of the jet after it had 
 issued into the room was reduced to 30 inches, the temperature of the air 
 would be 32° F. if we neglect the heat developed by the friction of the air at 
 the nozzle. In any actual case a great deal of heat would be developed by the 
 friction ; indeed, so great a fraction of the w^ork equivalent to the heat con- 
 verted would be reconverted into heat by friction at a small nozzle, that the 
 cooling effect might be difficult to observe ; but the result of the calculation 
 is sufficient to show that it is quite possible to get a flow of cool air, even 
 in the hottest climates, if the air be expanded by the motion of a piston in a 
 cylinder before it passes into the room. 
 
 We have supposed that the air is practically protected from heating 
 during expansion by the rapidity of the change of volume, but it is clear that 
 if the expansion takes place in an enclosure whose sides are very bad con- 
 ductors of heat, the amount of heat gained by conduction will be compara- 
 tively small, even if the expansion be slow. Thus it is possible, by means of 
 suitable arrangements of expansion cylinders, to furnish a supply of air 
 cooled by expansion to a temperature considerably below that of sm-rounding 
 bodies. If the air be compressed instead of being rarefied, a correspond- 
 ing rise of temperature is produced. The practical appHcation of this 
 principle of dynamical cooling to the refrigeration of ships and other pur- 
 poses will be considered in a subsequent section. The theory of it is 
 given in a paper by the late J. P. Joule in the ' Philosophical Magazine,' May 
 1845, p. 375, ' On Changes of Temperature produced by the Earefaction and 
 Condensation of Air ' ; and the suggestion of the method as applicable to prac- 
 tical problems of refrigeration or heating will be found in a paper by Sir W. 
 
44 HYGIENE 
 
 Thomson (' Glasgow Philosophical Society Proceedings,' vol. iii. Dec. 1852), 
 or still earlier, though in less practicable form, by Professor Piazzi Smyth 
 (' Report of the British Association,' 1850). 
 
 10. Water Vcqioiir.^ln the description of the effect of changes of physical 
 state upon the density of air no reference has been made to the composition 
 of the air, nor has any such reference been necessary, for the behaviour of 
 all gases and mixtures of gases, in respect of change of physical state, follows 
 the same laws, unless the conditions become such that some of the gas con- 
 denses to a liquid, or approaches very nearly to the state verging upon 
 condensation.' The only constituent of the atmosphere for which such a 
 state is likely to be reached is the water vapour, and it is on this account 
 that the amount of water vapour in the air is liable to such very wide variation. 
 We shall subsequently consider the evaporation and condensation of water 
 in detail and at present only draw attention to the effect produced upon the 
 density of air by the presence of the water vapour. It is easy to calculate 
 this effect when the pressure of vapour in the air has been measured (see 
 below, § 12). Regarding the weight of the cubic foot of moist air as made up 
 of dry air at the pressure B — e, and w^ater vapour at the pressure e, we get 
 for the weight of dry air per cubic foot from formula (1) 
 
 ^ ' I^t ^^"^'^ ^''^''''- 
 
 The weight of water vapour may be takentobefths the weight of the same 
 
 volume of dry air at the same temperature and pressure ; the moisture in the 
 
 5 e 491 
 
 cubic foot will therefore be - . ^ . -r—^ 566'9 grains, and hence the 
 
 8 B 459 ^ i " 
 
 total weight per cubic foot, or the density A, is given by the formula 
 
 A = — ^^•'''^ . — 56C"9 grains per cubic feet. 
 
 oO 459 + t 
 
 Moist air is therefore somewhat lighter than dry air at the same temperature 
 and pressure. 
 
 11. Effect ofhii'puTity. — The effect of the carbonic acid gas in the air upon 
 the density of the mixture is hardly appreciable. The density of CO.2 is one 
 and a half times that of air (1*529), so that replacing one volume in one 
 thousand of air by carbonic acid gas is equivalent to including in the space 
 matter which will increase the weight by -^J^-^jth part. This would have been 
 equally well secured if, instead of changing air for COo, the air had been 
 compressed, so as to increase the density by ao^oxr^^^ part, or if the temperature 
 had been allowed to fall sufficiently to produce the same change of density. 
 Thus replacing one volume per thousand of air by carbonic acid gas affects the 
 density in the same way as increasing the pressure by "015 inch or diminishing 
 the temperature by 0-24'^ F. 
 
 The particles mechanically suspended in the air increase the density by 
 the weight of the particles suspended in a cubic foot : this is a very variable 
 amount ; in mines, according to Angus Smith, it may be estimated to reach 
 3 grains. The attention of scientific men has recently been turned to these 
 dust particles with such interesting and important results that a special 
 chapter will be devoted to its consideration. 
 
 Among all the striking properties of the atmosphere which we breathe in 
 the open air, perhaps the most conspicuous is the uniformity of its density, 
 under standard couditioiis, in all parts of the globe and at all altitudes, 
 arising from the uniformity of its composition, as already alluded to. As all 
 the changes of composition, the production of carbonic acid by animal life 
 and combustion, and the absorption of carbon and elimination of oxygen by 
 
WABMING AND VENTILATION 45 
 
 plants, take place at the surface, and in very different amounts in different 
 parts of the globe, the uniformity of composition is very remarkable. . The 
 thorough mixing of the gases is due to the process known as diffusion, whereby 
 the particles of each of two gases in contact gradually permeate the space 
 open to both, and in a certain time distribute themselves over the whole 
 space, each as if the other were absent. The process of diffusion is itself a 
 slow one, but it depends on the area of surface of contact of the gases. This 
 surface of contact is immensely extended by the mechanical stirring up of 
 the gases by convection currents, and, as we have already seen, convection 
 currents are practically ubiquitous agents with gases of identical nature 
 throughout ; the difference of density of the gases offers another cause of 
 currents, so that the mixing of the gases becomes a very rapid process, and 
 a very short time is sufficient for the uniform diffusion of one gas over a 
 room, unless there is some arrangement which especially favours separation. 
 Escaping coal gas, for instance, can be detected all over a closed room, 
 though if allowed to escape in large quantity its specific lightness often 
 results in the formation of a layer of much stronger gas -mixture at the 
 ceiling. 
 
 ON WATEE VAPOUR IN THE AIR 
 
 12. We have already stated that the amount of moisture contained in a 
 gaseous form in the atmosphere is very variable. The cause of the variation 
 lies in the fact that conditions frequently occur under which the vapour con- 
 denses to water, and, on the other hand, in the absence of these conditions, 
 evaporation takes place from every exposed water surface or substance 
 moistened with water. The phenomena of condensation of vapour and 
 evaporation of water are exhibited in nature on a very large scale in the 
 formation of rain, fog, and mist, and in the disappearance of precipitated 
 moisture, respectively. The consideration of these phenomena belongs to 
 meteorology, to which the reader may be referred for a description of instru- 
 ments for determining the amount of moisture in the air (p. 164). But the 
 conditions of evaporation ajid condensation are of considerable importance to 
 ventilation and warming, for, in order to ensure comfort to the occupants, 
 the air supplied to a room must not be too dry nor yet too moist. 
 
 A given cubic space of air can contain only a certain amount of vapour, 
 dependent upon the temperature of the space and upon no other condition ; 
 the presence of air or other gases in the space, though it retards the evapora- 
 tion of water into it, does not influence the ultimate amount of vapour. The 
 evaporation will go on with extreme rapidity if there is very little air pressure 
 in the space — more slowly if the pressure is considerable — until the pressure 
 of the water vapour itself reaches a certain limiting value called the satura- 
 tion pressure, which depends upon the temperature. The relation between 
 the saturation pressure and the temperature is most concisely expressed by a 
 curve, the vertical height of a point of which shows the pressure corre- 
 sponding to the temperature expressed by the horizontal distance from a 
 zero line. Such a curve is shown by the thick line of fig. 1. The pressure 
 is given in hundredths of an inch of mercury and the temperature in Fahren- 
 heit degrees. 
 
 Air which contains moisture at its maximum, or saturation pressm-e, is 
 said to be saturated, and its temperature is said to be at the dew-point. 
 Any fall of temperature or slow diminution of volume determines the 
 deposition of moisture. Most frequently the saturation point is passed in 
 consequence of a gradual fall of temperature, arising from the conduction of 
 
46 
 
 HYGIENE 
 
 heat away from the air by the soUd bodies in contact with it ; in that case 
 the condensed moisture is deposited upon the cold surfaces, and the air may 
 not even be saturated far from the cold surface. The condensation of an 
 ounce of water vapour imphes that 08 lb. F. units of heat have been with- 
 drawn from it in order to dispose of the latent heat of the vapour, besides 
 the amount necessary to cool the air to the saturation point ; so that the 
 deposit of an ounce of water upon a window is direct evidence of the passage 
 of 08 lb. F. units of heat at least through the window glass. This is 
 sufficient to reduce the temperature of 375 cubic feet of air through 10° F. 
 so that the deposit of moisture may be used as a tell-tale for any large 
 abstraction of heat by conduction. 
 
 A deposit of moisture is sometimes formed upon a wall which is so much 
 
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 TEMPERATURE IN DEGREES FAHRENHEIT 
 
 Fig. 1. 
 
 cooler than the air in contact with it that the air is reduced in temperature 
 below the dew-point. This phenomenon may arise from two separate 
 causes : first, the replacement of the air by warmer and moister air without 
 any change of temperature occurring in the wall, as when in a sudden 
 change of weather from frost to thaw a warm moist wind replaces the cold 
 air in contact with the outsides of the walls of buildings rendered cold by 
 the previous frost. If the walls are porous the deposit may be absorbed and 
 unperceived. but if they are impervious to moisture, being, for instance, 
 cemented or painted, the beads of damp are very striking, and in this case 
 it is a very common error to suppose that the damp comes out of the walls 
 
WABMING AND VENTILATION 47 
 
 instead of being deposited upon them from the air. The second cause 
 referred to operates when the walls of a space are cooled, the internal 
 air remaining unchanged. Instances of this can be tolerably frequently 
 observed in the case of railway carriage windows, which, getting colder at 
 night or on passing through a cold district, show a deposit of moisture on 
 the inside. It is interesting, in many cases, to trace the cause of the 
 deposit of moisture which may be observed, and to decide, for instance, 
 whether the dampness observable on a house-wall is due to a deposit from 
 the inside air, in consequence of the difference of temperature between the 
 wall and the air inside, or to the moisture rising as water from the ground 
 or passing through the wall from some water supply outside the room. 
 
 If air is suddenly cooled dynamically, the moisture is not in the first 
 instance deposited upon the solid substances in contact with the air, but on 
 the small solid particles, or dust, floating in the air ; these particles loaded 
 with their deposit of moisture form a mist which gradually settles upon the 
 ground as rain, or upon the sides of the vessel if the experiment be made 
 upon a small scale. 
 
 Mr. John Aitken has found that solid nuclei furnished by dust in the air 
 are essential to the condensation of vapour in the form of fog, and if no such 
 nuclei be present it is impossible to get the cloud which forms so easily in 
 moist dusty air when suddenly rarefied. Solid surfaces also differ very con- 
 siderably in their power of causing a deposition of moisture, so that it may be 
 difficult to test very accurately whether air is truly saturated or not. If we 
 regard air as saturated when any very small rarefaction would cause a 
 deposit on the dust nuclei, then certain substances condense the moisture 
 out of air which is not thoroughly saturated. The chemical substances 
 strong sulphuric acid and phosphoric anhydride remove practically every 
 trace of moisture from the air in contact with them ; calcium chloride and 
 caustic lime also absorb moisture freely from the air, and may be used to dry 
 it if particularly dry air be required ; but these cases must be regarded as 
 instances of chemical actions between the absorbing substances and the 
 moisture. Other substances become damp — possibly on account of fine pores 
 in their surfaces — in air which is not nearly saturated. Wood, whalebone, 
 catgut, are all in their way hygroscopic, and so is hair of any sort when 
 freed from grease. In consequence, a woollen blanket thoroughly dried will 
 condense several pounds of water in its pores in a damp cellar, and a 
 sudden change in the weather from cold to warm will often cause woollen, 
 linen, and cotton materials, especially woollen ones, to become remarkably 
 damp, through the absorption of moisture from moist but not saturated air. 
 
 A large quantity of moisture is introduced into the air of rooms by the 
 respiration of human beings and by the burning of gas. Unless the moisture 
 is removed by taking away the heated air, it becomes deposited upon the 
 walls or windows as the room cools down through the night. This leads us 
 to remark upon methods of drying a room, for which it is often supposed to 
 be sufficient to light the gas in it, leaving it shut up. As a matter of fact, 
 but small effect can be produced in this way unless ventilation is provided to 
 carry away the heated air loaded with the moisture, for unless the moisture 
 is actually carried out of the room in some such way, it is simply evaporated 
 by the heat, condensed again upon the windows and walls, and re-evaporated 
 the next day, only to be recondensed in the following night. 
 
 Air which is not saturated continually takes up moisture from any sm-face 
 of water in contact with it, so that a current of dry air passing over a moist 
 siu'face is a very effective desiccator. The rate at which the evaporation 
 takes place depends upon the amount of moisture already in the air, or 
 
48 HYGIENE 
 
 rather upon the ratio of the amount it contains to the amount it would 
 -contain if saturated. This ratio is sometimes called the fractional humidity 
 of the au", and is generally estimated by finding the actual pressure of the 
 water vapour in the air and comparing it with the saturation pressure. 
 From the curve of saturation pressm'e it will be seen that a given fractional 
 humidity will correspond to widely different quantities of moisture in the air 
 according to the temperature. The thin-line curve of fig. 1 (p. 46) is the curve 
 of vapour pressure corresponding to the fractional humidity of the air, '5 ; that 
 is, the vertical height of a point on the thin-hne cm've indicates the pressure 
 of vapour in the air, at the temperature corresponding to the horizontal 
 distance of the point from the zero line, when the air contains half the 
 possible amount of moisture at that temperature. Thus air may be rendered 
 effectively dry without altering the amount of moisture in a cubic foot of it 
 by simply raising its temperature, or it may be rendered effectively damp 
 without adding any water to it by simply cooling it. 
 
 Hence arise the differences in the dampness of the same air under various 
 conditions. The external air is sometimes saturated, but it is very seldom 
 in England that the humidity falls below the fractional value "5. The 
 average humidity in England may be taken at "75. In inland tropical 
 countries, however, it is frequently much drier than in an insular climate like 
 that of the British Isles. 
 
 A wet surface exposed to a current of dry air suffers considerable loss of 
 heat in consequence of the evaporation ; thus a body wrapped in wet muslin 
 Avill have its temperature reduced from 60° F. to 40° F. if it be exposed to a 
 continuous current of air, itself at 60° F., when the fractional humidity of 
 the air is "24. It follows that damp substances exposed to a ventilation current 
 of very dry air may suffer considerable depression of temperature and cause 
 chills to persons exposed to it. The rapid evaporation, too, from the skin 
 produced by a current of dry air is sometimes injurious, so that ventilation by 
 artificially warmed air is unsatisfactory unless provision is also made for 
 moistening the air to a suitable state of humidity. The humidity should not 
 be less than 60 per cent. 
 
 The moistening can only be secured at the expense of the heat necessary 
 to produce the evaporation, and ought to be carried out with due regard for 
 the fact that if the room into which the warmed and moistened air is carried 
 is surrounded by cold walls and windows, the whole arrangement is very 
 similar in principle to a still, and may result in pernicious deposits of water 
 on the walls. This consideration leads us to point out one of the advantages 
 of supplying part, at any rate, of the artificial heat of a room by radiation 
 which primarily warms the walls and tends to keep them hotter than the 
 air, and so prevent any deposit of moisture upon them. 
 
 ON DUST AND SMOKE 
 
 13. The recent investigations of several scientific men, particularly Mr. 
 John Aitken,^ F.E.S., and Dr. 0. J. Lodge, ^ F.E.S., into the phenomena ex- 
 hibited by the dust particles carried in the atmosphere, have brought to light 
 and explained some very important facts. As bacterial germs must be included 
 in the category of solid particles conveyed by the air, these recent additions to 
 our knowledge are of great interest to those concerned in securing the purity 
 of the air we breathe. 
 
 ' On the Formation of small clear Spaces in Dusty Air, Trans. B.S.E. xxxii. 1884, 
 p. 239. - Nature, xxxi. 265. 
 
WABMING AND VENTILATION 49 
 
 It is unnecessary here to specify exactly the nature of the solid particles 
 that may be found in air. Fragments of all kinds of substances, animal, vege- 
 table, and mineral, may be exhibited. The nature and character of the sohd 
 impurities carried by the air will be found fully discussed in the article Am. 
 
 Ait ken has recently described a method of actually counting the number 
 of dust particles in a cubic centimetre of air. He iirst dilutes the dusty air 
 with air altogether free from particles, and when a suitable stage of dilution 
 has been reached he loads the remaining particles, contained in 1 c.c, with 
 condensed water vapour, and thus causes their rapid precipitation upon a 
 measured surface, and then counts the number deposited by means of a 
 magnifying glass. An account of the result of experiments upon a series of 
 different specimens of air is given in a recent volume of Nature (xli. p. 394), 
 from which it appears that the number of particles in a cubic inch of ' fresh ' 
 air may vary from two thousand in open country to over three millions in 
 cities, and in gas-heated rooms the number may be ten times as great. 
 
 The method of determining the number of bacteria in air is dealt with in 
 the article Air, p. 28. 
 
 The suspended dust particles are constantly falling through the air in 
 consequence of the action of gravity, but the rate of fall is very slow, the 
 motion being retarded by the friction they meet with. It is, however, quite 
 appreciable and can be made visible by suitable apparatus and illumination. 
 The dust is maintained in suspension in the air by the currents due to wind 
 or to convection. If the air is still for a long enough period, the dust 
 gradually settles upon all horizontal surfaces, and the air becomes tolerably 
 free from it. A considerable part of the dust of air may indeed be removed 
 by simply allowing the air to flow slowly over a horizontal surface ; if the 
 motion is rapid, eddies are produced by the friction of the air against the 
 sides of the channel, and the dust is carried forward and is not allowed to 
 settle. Moreover, if the horizontal surface is wet, the deposit of dust does not 
 take place so freely. The explanation of this phenomenon is probably to be 
 found in the fact that the water is constantly evaporating. The molecules 
 of water are shot out from the surface, and so cause a continuous bombard- 
 ment of the air next to it ; in the process of diffusion the molecules are 
 gradually driven further away from the surface. These molecules are inde- 
 finitely smaller than the dust particles, and in the bombardment the dust 
 particles get hammered by the rising water molecules, and are thus driven 
 away from the surface and not allowed to fall. The molecules of the air are 
 themselves in rapid motion, so that the dust particles receive blows from every 
 quarter ; but those from the direction of the evaporating water surface pre- 
 dominate, and so the dust is kept at a distance. 
 
 In a precisely similar way the dust will be kept off a hot surface exposed 
 to dusty air, which is cooler ; only in this case the molecules by which the 
 dust particles are bombarded will all be of the same kind. Those, however, 
 which touch the hot surface rebound with greater velocity than they strike, 
 and so there is a rain of molecules leaving the wall with greater average 
 velocity than that of the molecules of the cooler gas near. Again, the impacts 
 are heavier and the dust is kept off. 
 
 Just the reverse effect is produced if the surface is cold and the air 
 warmer ; then the predominant effect of the general bombardment drives the 
 particles towards the wall and a deposit of the dust takes place. 
 
 When a surface is both moist and warm the repelling action is still 
 more effective, since both causes combine ; and to this, as pointed out by 
 Aitken, is probably due our comparative immunity from diseases that might be 
 contracted from the passage of particle -laden air through the bronchial tubes. 
 
 VOL. I. E 
 
50 
 
 HYGIENE 
 
 The most conspicuous illustration of the phenomena here described la 
 furnished by the deposit of soot in a chimney, the sides of which are coolei- 
 than the sooty air passing up the chimney. But on a smaller scale the 
 same phenomenon is exhibited wherever warm dusty air passes over a cooler 
 surface. The subjoined sketch (fig. 2) shows a deposit of soot or dust accumu- 
 lated on a wall, in eighteen months, over a pair of vertical hot-water pipes which 
 rise from the floor of the room and pass through the wall. It furnishes a very 
 fair measure of the ca'oss-section of the convection current of hot air which is 
 the result of the heating effect of the pipe, and every hot-water pipe near a 
 wall tells a similar tale. A similar deposit can always be observed round the 
 outlet ventilators for warm air, where the dust can often be seen sticking to 
 the edges of the opening like iron filings to a magnet. 
 
 If a cold surface be held above the smoky flame of a lamp, a deposit of 
 
 Fig. 2. 
 
 soot is at once produced, but if the surface be previously heated no deposit 
 takes place. 
 
 The thickness of the dust deposit will depend upon the difference of 
 temperature between the air and the surface, and if there are inequalities in the 
 temperature difference at different parts of the surface the difference in the dust 
 deposit will show it. It is probably on this account that the pattern of the 
 joists above a ceiling is gradually outlined upon the ceilmg by a smoke or dust 
 deposit, for those parts of the ceiling which are backed by joists conduct the 
 heat of the room away less rapidly than the intermediate portions. 
 
 These dust deposits, which are incidental to water-pipe and hot-air 
 systems of warming, could only be avoided either by securing that the walls 
 are made warmer than the air by means of radiation from open fires or by 
 
WARMING AND VENTILATION 51 
 
 introducing the air free from dust. It is not possible to arrange matters so 
 that either plan shall be perfectly feasible, but attention to either or both points 
 may help to reduce the amount of the deposit. The deposits are, liowever, 
 not without their advantages. Considering the nature of the dust particles, it 
 is sometimes better to have them nailed to the v/all than floating about in 
 the air, however unsightly the result may be, for when once fixed to the wall 
 they are not easily dislodged, and they are out of harm's way. Undoubtedly 
 the best way would be not to allow such particles to enter the room with the 
 air supplied for ventilation. A complete air-filter is furnished for small 
 quantities by a plug of cotton-wool moistened with glycerine ; but this plan 
 is not applicable where very large quantities of air are required, though large 
 cotton-wool filters are sometimes used. In the mechanical system of venti- 
 lation adopted in the chemical laboratory of University College, Dundee, ^ the 
 air is filtered by being passed through jute cloth (light Hessian) stretched on 
 frames 17 feet long by 4 feet wide. In this case the presence of the screen 
 actually increased the delivery of air by nearly ten per cent., probably by 
 preventing eddies. The screens collected 2^ ^^s. of dirt in seven weeks. They 
 last about a year, and the cost is about Id. per yard. 
 
 A filter of any sort is more effective if it is colder than the air passing 
 through it ; so that it would be well to interpose the filter in such a position 
 that the air passes through it after being warmed. 
 
 A large chamber into which the warmed air is delivered before being 
 supplied to the rooms would act as a partial filter, from the fact that its walls 
 would be cooler than the air. Indeed, if the air is passed along a narrow 
 annular passage between two coaxal metal tubes, one of which is kept hot 
 and the other cold, the air may be entirely purified from dust ; ^ but this plan 
 has only been tested on the scale of laboratory experiment. 
 
 In order to take out some of the dust from air introduced by Tobin tubes, 
 a small chamber is sometimes formed at the bottom of the tube, and, the motioxi 
 of the air in the chamber being comparatively slow, part of the dust falls upon 
 the bottom. A layer of water has been recommended in addition ; but this 
 can hardly assist the deposit, for reasons stated above. 
 
 It is perhaps hardly necessary to point out that all conduits for air, 
 especially for artificially warmed air, are liable to accumulations of dust, 
 although the air which passes through them may not be drawn from an 
 especially dusty supply. It is well that the dust should be thus de- 
 posited in the conduits instead of passing into the rooms ; but at the same 
 time it should be remembered that the conduits are liable to become fouled 
 thereby, and to prove a source of serious danger to health unless they are 
 periodically and properly cleaned, and provision should therefore always be 
 made for getting at the conduits for this purpose. Neglect of this precaution 
 sometimes discredits systems for supplying warm air which are otherwise 
 free from objection. 
 
 Another method of depositing the dust-particles consists in electrifying 
 them by discharging electricity into the dusty air from a sharp point con- 
 nected with an electrical machine. The particles then form aggregations 
 and fall. This effect of electrifying dusty air was described by Aitken, but 
 more fully discussed by Lodge. The former has suggested that the effect of 
 thundery weather in turning milk sour, and the like, may be due to the un- 
 usual amount of deposit of bacteria in consequence of the electrification ; 
 while the latter has discussed the possible application of the method on a 
 large practical scale to the clearing of the atmosphere from fog, dust, or smoke. 
 
 ' Carnelley's Bejport on the Heating and Ventilation of Sclwols, p. 31. 
 - Aitken, I.e. 
 
 e2 
 
62 
 
 HYGIENE 
 
 ON THE MOTION OF AIK. GENERAL THEORY OF VENTILATION 
 
 14. The process of continuous ventilation consists in the admission of a 
 quantity of air to a room, or other nearly closed space, through ducts of 
 various forms and sizes, comprised in the general term ' inlet,' and the simul- 
 taneous removal of a similar quantity of air by other ducts, which are 
 generally termed ' outlets ' or ' exits.' The inlets may be, in any particular case, 
 open doors or windows, special tubes provided for the purpose, or merely the 
 crevices which always exist, as the doors and windows cannot be made to fit 
 perfectly air-tight in their frames. To give a complete account of the motion 
 of the air and its causes is impossible, for it would practically be the solution 
 of a most complicated problem in the motion of gases, as a brief consideration 
 of a simple case will show. Let us take a most elementary system, which 
 may be diagramatically represented, as in fig. 3. The space to be ventilated 
 is represented by the oblong A ; it is provided with a single inlet tube, I, and 
 a single outlet, 0. The cause of the motion of the air may be as simple as 
 possible, namely, a continuous suction at 0, or a blowing in of air at I ; and 
 we will suppose that either of these causes corresponds to a difference of 
 pressure, between the external aperture of I and the external aperture of 0, 
 
 which is constantly maintained by some 
 suction or blast apparatus. In conse- 
 quence of this difference of pressure, air 
 flows along the inlet to A, and an equal 
 quantity flows out of A by the outlet. 
 Now, for a given difference of pressure, 
 say that due to one-tenth of an inch of 
 water, the amount of air which passes 
 through the system depends upon the 
 area of section, the length and shape of 
 the inlet, and the nature of its internal 
 surface, and upon the corresponding pro- 
 perties of the outlet tube ; and it is, more- 
 over, affected by any changes of tem- 
 perature which the air may experience in passing through the system. The 
 effects of these modifying circumstances upon the flow of air, which may be 
 roughly classified as being effects of friction and of temperature, are at best 
 only very inaccurately known, so that the calculation of the amount of flow 
 for any special case is only an approximation ; and this is only part of the 
 problem. A complete knowledge of the ventilation of a room refers not 
 only to the amount of air supplied and simultaneously withdrawn, but also to 
 the path which the incoming air takes when it enters the room. It is a matter 
 of the greatest consequence whether the fresh air supplied proceeds directly 
 to the outlet or takes a more devious course. We ought, therefore, to be 
 able in some way to specify the path which the air takes after it enters the room 
 until it is finally disposed of by passing out at the exit ; or we might aim 
 at stating the direction in which the air is moving at any point of the room. 
 But the air of any inhabited room is generally, from causes previously 
 mentioned, in a state of absolutely indescribable turmoil, and the precise 
 motion defies calculation. Even if we could perform the necessary calculation 
 under perfectly permanent conditions, we should have solved an ideal problem 
 and not a real one ; for the conditions may be said to be practically never 
 permanent. All this refers to the simple system we have imagined, and 
 every actual system is more or less compHcated by the multiplicity of inlets 
 
 Fio. 3. 
 
WABMING AND VENTILATION 53 
 
 and exits, and causes of flow. We cannot, therefore, undertake the complete 
 numerical solution of the general problems of ventilation ; but we shall be 
 able to show that certain of the phenomena — for instance, the motion of air 
 through tubes and apertures — do lend themselves to numerical calculation, 
 and the general character of others of them, as the distribution of air-currents 
 in a room, can be inferred from observation of special cases ; so that really 
 useful information may be obtained from a consideration of the effects which 
 are likely to be produced under given conditions. 
 
 We shall first suppose our questions limited to cases of what is termed 
 * steady ' motion, which may be explained as follows : If we commence 
 drawing air out of a room by suction at one end of the ventilation system, 
 successive portions of the air are set in motion — some of the air of the 
 room is drawn out, the pressure in the room is reduced, and air begins to be 
 drawn in through the inlet. If the suction is maintained perfectly constant 
 for some time, a continuous steady flow is established ; that is, as much air 
 comes in through the inlet as is drawn through the outlet ; the pressure in 
 the interior is kept diminished, but always by the same amount ; and the 
 amount of air in the room does not alter any further ; and the same is true of 
 any portion of the space in the inlet or outlet tubes — it always contains the 
 same amount of air, neither more nor less. An observer, if he could see the 
 motion of the air across a transverse section of one of the tubes, would see 
 it constantly flowing at the same rate ; in other words, the velocity of the 
 motion of a portion of the air depends upon its position only, and does not 
 vary from time to time. Since the quantity of air in the space which is 
 contained between any two parallel sections of the system is thus invariable, 
 it follows that the amount which crosses the one section to enter the space 
 is the same as the amount which crosses the other section leaving the space. 
 We shall refer to this statement as the Law of Continuity of Flow. It must 
 be remembered that it is the quantity of air which flows equally across every 
 transverse section when the motion is steady, and that the quantity flowing 
 is measured by the toeight of air which passes the section per second or per 
 minute, as the case may be. The volume which is occupied by a quantity 
 of air when it leaves the outlet of the system may be very materially different 
 from the volume which an equal quantity actually occupies before entering 
 the inlet, because it may be at a different pressure and different temperature. 
 So that, strictly speaking, the volume of air which crosses any section of a 
 ventilation system is not, by the law of continuity of flow, equal to the 
 volume which crosses any other parallel section, in consequence of the 
 compressibility and expansibility of the air. If we were dealing with a liquid 
 instead of a gas, the changes of volume which can be produced by changes 
 of pressure and temperature within the range of ordinary observation in a 
 mass of liquid like water are so extremely slight, that there would be no 
 practical error in regarding the volume of the liquid which crosses any section 
 as being the same throughout the system ; and, indeed, even when we are 
 dealing with air, there are many cases in which the variations of volume 
 which take place are comparatively slight, for the differences of pressure and 
 temperature which produce them are not large ; so that if we altogether 
 disregard the alteration of volume, and consider the volume of air which 
 traverses successive sections to be equal, instead of the weight of air, we shall 
 probably be within the limit of error which is imposed by inaccm-acies 
 of measurement. As the quantity of air which crosses any section of a steady 
 ventilation- system is always the same at every part of the system, it is a 
 most important element in the specification of the action of the system ; we 
 shall frequently refer to it as the ' flow.' Strictly speaking, it ought to be 
 
54 HYGIENE 
 
 measiired by the weight passing any section ; but as the variations in density 
 of the air along the circulation are slight, we shall generally suppose the 
 flow measured by the volume which passes any section. 
 
 To take a specific example. Suppose that we have a room provided with 
 a chimney and a fireplace in Avhich is a gas-jet instead of afire ; and suppose 
 the opening of the fireplace cloped by a well-fitting screen with a single 
 circular opening in it ; and suppose, further, that we measure, by means of an 
 apparatus to be described later (p. 105), the volume of air which flows through 
 this opening, to be 24 cubic feet per minute, the temperature being 62° F., the 
 barometric pressure being at the same time 30 inches : then, referring to 
 equation 1, p. 42, we find that the u'cight of air which passes per minute 
 through this aperture, i.e. the weight of 24 cubic feet at G2° F. and 80 inches, 
 is 12,840 grains ; and by the principle of continuity of flow, provided the 
 motion be steady, the same w' eight of air passes out of the top of the chimney 
 and the same weight enters the room by the chinks in the windows and door. 
 But the volume is not the same, for the entering air will have the temperature 
 of the outside — 42° F., suppose ; so that the volume of outside air which enters 
 
 will be diminished to — — — — ~'- x 24, i.e. about 23 cubic feet : and if we 
 459 + 02 
 
 suppose the temperature of the air issuing from the chimney to be 150° F., 
 
 the 12,840 grains when they pass out of the chimney will occupy a volume 
 
 — '—— — ^ X 24 cubic feet, i.e. about 28 cubic feet. We have left pressure 
 451> + 62 ^ • 
 
 differences out of account, though there is a difterence of pressure on the 
 
 whole of about ^Vptl^ of an inch in the case mentioned. As this is less than 
 
 r, ,}( ^ ^ th part of the whole pressure of the atmosphere, the variations on this 
 
 account of the volume of the air delivered at different parts of its route are 
 
 so small that they may safely be disregarded. 
 
 We have laid down the condition that the motion is steady ; if experiment 
 were made upon the actual instance given above, it would in all probability 
 be found that the wind blowing across the top of the chimney, or directly 
 upon the windows, seriously interfered with the steadiness of the motion. 
 In fact, in some actual measurements, the flow through the same aperture in 
 four successive minutes was 24*5, 24'1, 22*9, 25*1 cubic feet respectively. In 
 such a case we have to infer what the flow would be under steady condi- 
 tions, by taking the mean of a number of consecutive observations, or 
 prolonging one observation over a long period. The effect of unsteadiness 
 due to the wind is less, the greater the flow produced by permanent artificial 
 causes ; or, in other Avords, the observations of artificially maintained ventila- 
 tion currents are more definite and trustworthy the greater the velocity. 
 This should be borne m mind in considering observations of the flow in 
 ventilation channels. When the artificial current is weak and the wind at 
 all strong or gusty, no observations of any value can be obtained. 
 
 The law of continuity of flow may be regarded as the first fundamental 
 principle in the theory of ventilation, and needs only to be stated for its 
 importance to be allowed. It accomits for many of the most easily observed 
 phenomena of ventilation ; the disagreeable draught which a fire produces 
 in a room is one of the most familiar instances of its application. At the 
 same time it ia one of the principles most frequently disregarded, for, of the 
 number of houses built, only a very small fraction exhibit any evidence of 
 proAision for air to enter in a satisfactory manner to replace that which must 
 necessarily be removed by the chimneys and other outlets. 
 
 For the purpose of numerical calculation the law of continuity can only 
 be applied to those sections of a system where the motion is steady. The 
 
WABMING AND VENTILATION 55 
 
 steady state is gemerally well established in the ducts by which the air enters 
 or leaves the ventilated space ; but in the space itself local causes interfere 
 with the steadiness of the motion of the air, and may cause the velocity of 
 flow at any point to change from time to time in a manner which cannot be 
 accurately calculated numerically. We must therefore analyse the general 
 problem into two parts and treat them separately. The first part deals with 
 the steady flow through the ducts, and this we will denominate the ' general 
 circulation ' in the system ; the laws which regulate it will be stated and ex- 
 emplified. The second part deals, on the other hand, with the motion of the 
 air in the ventilated space, which is generally irregular ; about this part we 
 can only give the results of observations upon special examples, which will, 
 however, enable us to form a rough estimate of the approximate distribution 
 of flow in a room under specified conditions, and from which some principles 
 of general application can be derived. The irregularity of the motion of the 
 air in the room does not, however, interfere with the general application of 
 the law of continuity, which enables us to say that the total quantity of air 
 entering by the inlets is equal to that which passes in the same time through 
 the outlets. 
 
 General Circulation 
 
 15. In order to form a definite conception of the laws which govern the flow 
 of air through ducts, we shall first consider their application to a very simple 
 case, and then show how the theory may be extended to more complicated 
 cases. This method of treatment has been suggested by a very instructive 
 work by M. Murgue on ' The Theories and Practice of Centrifugal Ventilating 
 Machines,' translated by A. L. Steavenson. The simple but most typical 
 case of flow of air, which forms the starting-point of the theory, is that in 
 which air is driven through an aperture in a thin plate, when a steady dif- 
 ference of pressure is maintained betAveen the two sides of the plate. We 
 shall not now stop to consider the way in which the pressure-difference can 
 be maintained ; to that part of the subject we shall devote a special section 
 subsequently. We may picture to ourselves two very large spaces — two rooms, 
 for example, A and B, fig. 4. — with 
 a small aperture a in a thin sheet 
 of metal separating them. The pres- 
 sure in A is to be maintained at the 
 steady value, say P lbs. per square 
 foot, and the pressure in B at j; lbs. 
 per square foot. We must, however. Fig. 4. 
 
 make clear what is here meant by 
 
 the pressure of the air. The motion of air through the orifice will affect the 
 pressure of the air in its neighbourhood ; if we carry an instrument for measur- 
 ing pressure (for instance, an aneroid barometer made sufficiently delicate to 
 indicate the very minute changes of pressure that occur in such cases) from 
 any remote corner of A towards the orifice, the pressure will remain, practically 
 speaking, constant, until a position quite near to the orifice is reached ; then 
 the pressure will show signs of diminution, and it will continue to diminish 
 until the orifice is passed, and even after that for a very short distance, until 
 we arrive at the position of most rapid motion ; after that the pressure will 
 gradually increase to a uniform value in the space B at any considerable 
 distance from the orifice. We may call those parts where the air has any 
 considerable motion the * rapids ' ; and when we speak of the pressure of the air 
 in the space A or B, it must be understood that the measure is not taken 
 within the rapids. Some idea of the extent of the rapids may be obtained 
 
 
 
 .-\\ 
 
 
 
 
 A 
 
 >:^:| 
 
 A-~ 
 
 B 
 
•56 HYGIENE 
 
 from a consideration of the special cases of the flow of air in the neighbour- 
 hood of inlets and outlets which will be described hereafter (§ 30). 
 
 In consequence of the steady difference of pressure, equivalent to (P — ^j) 
 lbs. per square foot, a steady motion is mamtained through the orifice. At 
 the orifice itself, the air is converging from all directions, so that the ' vein ' 
 of flowing air contracts after passing the orifice until the position of maximum 
 velocity is reached. The vein afterwards spreads out again as the velocity 
 diminishes, and has therefore a section of minimum area at the part at which 
 its velocity is greatest ; and there, moreover, the direction of the motion of 
 each portion of the air, as it passes, is perpendicular to the plane of the orifice. 
 The general character of the vein of air may be to a certain extent inferred 
 from the analogous case of the motion of water through an opening in a 
 plane plate, or from the flow of a river through the arch of a bridge ; the 
 eddies that are formed in the debatable region between flowing stream 
 and dead water have their counterpart in the eddies which are set up in the 
 air beyond the orifice. 
 
 There are also other phenomena which the motion of the air exhibits. 
 When air expands on change of pressure the temperature is reduced, so the 
 air in the rapids will be cooled. The differences of pressure which occur in 
 ordinary cases of ventilation are, however, extremely small, and some of the 
 heat is returned to the air by the friction at the orifice and in the space B. 
 In those cases in which a greater difference of pressure is required, as in 
 mines, the flow takes place, not through an orifice in a thin plate, but through 
 long shafts, and the temperature is really determined by the shaft in which 
 it flows ; hence we may disregard the changes of temperature that occur in 
 consequence of the expansion. 
 
 16. Let us now consider more closely, but still in quite general terms, the 
 conditions that are necessary in order to maintain the steady flow through 
 the orifice. The air will not go through it of its own accord ; it requires some 
 agent to drive it — to maintain, in fact, the difference of pressure. There are 
 several practical ways of doing it : blowing with suitably arranged bellows 
 into the space A would be one way ; using an engine to drive a fan blast 
 another ; maintaining a fire to heat air in a chimney in communication with 
 B, a third ; but all these involve the use of working agents — the worker of the 
 bellows, the engine, or the fire as the case may be. To drive a pound of air 
 through the orifice every second requires the expenditure during each second 
 of a certain amount of work, which may be measured in foot-pounds, or the 
 number of pounds weight which the same amount of work would hft through 
 a foot. We shall give a special name to the amount of work, measured in 
 foot-pounds, which must be spent in driving one pound of air through the 
 orifice : it will be called the Head, corresponding to the flow. We shall subse- 
 quently calculate the head for a number of special cases of circulation, but 
 for the present we shall content ourselves with specifying that when we say 
 that the head for a flow through an orifice is one-tenth of a foot-pound per 
 pound, we mean simply that every pound of air which passes through the 
 orifice uses up in doing so one-tenth of a foot-pound of work. We shall 
 generally denote the head in foot-pounds by the symbol lb-' 
 
 ' In order to give a more definite idea of the meaning of the term ' head,' we may 
 Tefer to the analogous case of the tlow of water through an orifice when the water is at 
 different levels on the two sides. In that case the ' head ' (or work done in foot-i30unds 
 jier iDound of water flowing through) is equal to the difference of level, h, of the water on 
 the two sides of the orifice. Similarly, in the case of air the head represents the height to 
 •which air would have to be piled on the one side of the orifice in order that the difference 
 of weight of the columns on the two sides might produce the same result as the head, 
 
WARMING AND VENTILATION 57 
 
 We can consider how the work is spent as the air passes through the orifice, 
 including in the time of the passage of a portion of air the whole time from 
 the instant at which the portion becomes involved in the rapids to the instant 
 when it reaches the most contracted part of the vein. Its velocity becomes 
 gradually accelerated from its initial value, which is practically zero, to the 
 maximum value, which we may take to be v. It is a well-known dynamical 
 principle that to generate a velocity of -y-feet per second in a mass of 1 lb. 
 
 requires — or — - — - foot-pounds of work ; hence each pound of air 
 2(/ 2x32-2 
 
 requires for the production of the velocity — — — ^ foot-pounds of work, 
 
 which is subsequently frittered away to heat by the friction in the second 
 space B and lost for all practical purposes. If this were the only way of 
 spending the work, we should have the simple relation between the head *It), 
 and the maximum velocity v. 
 
 But the calculation, of which the equation just written expresses the result, 
 proceeded on the assumption that the head was devoted entirely to the increase 
 of velocity of the air. This would leave out of account the work which is lost in 
 friction at the orifice ; so that the equation as it stands is not directly applicable. 
 It is fortunately unnecessary for us to attempt to correct it by estimatmg 
 separately the effect upon the flow which is produced by the convergence of 
 the vein, the friction and the eddies which it causes, and the other phenomena 
 which occur in the rapids. Experiments have shown that the resultant 
 effect can be represented with sufficient accuracy for practical purposes by 
 supposing them to produce a constriction of the area, over which the maxi- 
 mum velocity v may be supposed to be uniform. Thus, what really takes 
 place when a difference of pressure is maintained on the two sides of an 
 orifice is, that air flow^s through the orifice a in convergent directions and 
 meets with frictional resistance ; the flow in the general circulation can, 
 Jiowever, be calculated on the supposition that it is equivalent to a flow which 
 passes perpendicularly through a narrower orifice over which the velocity is 
 uniform, and equal to the maximum velocity which the head would produce 
 if there were no friction. The velocity can thus be calculated by the formula 
 given above. The experiments further show that the area of the contracted 
 orifice always bears the same ratio to the actual orifice for different heads, so 
 that the contracted orifice can always be calculated from the actual area, a, 
 ■of the given orifice by multiplying by a fraction, Tc, which is called the co- 
 efficient of contraction. Thus the area of the contracted orifice is ha. We 
 may now state the resultant effect of the action of a head, lb ; it produces a 
 flow which is represented by a uniform velocity, v, of the air perpendicularly 
 across an area Tea, where a is the area of the orifice, and h the coefficient of 
 contraction, the velocity at the contracted area being related to the head lb. 
 
 by the equation lb = ^ — ; 
 
 2 X 32-2* 
 
 supposing that the air did not vary in density and could have a free surface like water. 
 It follows from this that the difference of pressure on the two sides is that due to a column of 
 air of uniform density whose height is numerically equal to the head, or is equal to that of 
 
 a column of water whose height is h feet, whereZi = i?^ , A being the density of the air 
 
 A 
 
 aear the orifice, and A' the density of water. The ratio — is the specific gravity of air 
 referred to water, and may be taken as being approximately equal to 1/800. 
 
58 HYGIENE 
 
 We can further calculate what volume of air passes, for it is equivalent to 
 the volume delivered at velocity v through the contracted area ka. If areas 
 are measured in square feet, and velocities in feet per second, the flow will 
 evidently be hav cubic feet per second. Let us call the volume dehvered in 
 cubic feet per second V ; then 
 
 and we get for the relation between the volume V delivered at the contracted 
 area and the head If) which causes the flow, 
 
 113 = \ _. 
 
 Pa^x 2x32-2 
 
 The volume delivered across any other section may be calculated in 
 accordance with the law of continuity of flow ; but if we neglect the differ- 
 ences of density of the air at different sections, as we generally may do with- 
 out appreciable error, we may assume that the vohmie delivered is the same 
 across any section ; though, as already pointed out, it is really the weight of 
 air which passes any section which is the same throughout. 
 
 The flow through the orifice may as a rule be easily found experimentally 
 by means of an air-meter (see p. 105), which when properly used gives the 
 mean velocity perpendicu.lar to the area. The corrected reading of this 
 instrument gives the value Y ja for any opening through wloich the air flows, 
 and, a being measurable, the value of V becomes a quantity which is capable 
 of fairly accurate experimental determination. It is, in fact, the measurement 
 in relation to ventilation which is most easily carried out in practice, and 
 hence the equation connecting 1b and V is of very great importance. We 
 may regard it as the statement of the second fundamental principle of venti- 
 lation, the law of relation between head and flow for an orifice in a thin plate. 
 
 The constant h is not very accurately known, but it does not differ much 
 from "65, whatever be the shape of the orifice.^ In what follows, except where 
 otherwise specified, we shall take its value at '65, and the law of relation, 
 between head and flow through an orifice in a thin plate becomes — 
 
 1h= I = _!_. 
 
 2 X 32-2 X (•65)2a2 ^Ta^ 
 
 We may transpose the equation to the following : 
 
 1b_ 1 
 
 V^ 27a2 
 
 and we notice that the right-hand side of the equation is a numerical constant 
 for an orifice of given area ; so that we may enunciate the second fundamental 
 law as follows : — The ratio of the head to the square of the flow is a constant 
 which is inversely proportional to the square of the area of the orifice ; this 
 constant we may if we please call the resistance of the orifice, and ex- 
 press the statement thus : — The head is equal to the product of the resist- 
 ance of the orifice and the square of the flow, or the flow is equal to the 
 square root of the head divided by the resistance of the orifice, and we may 
 write the equation finally : 
 
 when E is the resistance and V the flow. If the head is expressed in foot- 
 pounds per pound of air and the flow in cubic feet per second, E will be equal 
 
 to — — when a is the area of the orifice in square feet. Those who are 
 
 27a^ 
 familiar with ordinary dynamics may prefer the resistance of the orifice 
 expressed in more general terms, so that the condition of referring the head 
 ' See Peclet, TraiU de la Chaleur, i. 154. 
 
WARMING AND VENTILATION 59 
 
 and flow to particular units need not be imposed. We therefore write for R 
 its equivalent value, Iji^Agk-a^), where g is the gravitational acceleration of any- 
 falling body, a the area of the orifice, and k the coefficient of contraction. 
 
 In concluding this section we may give a definition of the resistance of 
 an orifice in the technical sense in which we shall use the term. It is the 
 factor by which the square of the numerical value of the flow through the 
 orifice must be multiplied in order to give the value of the head which pro- 
 duces the flow. 
 
 One of the direct results which follow from this equation is, that we are 
 enabled to calculate the head between the two sides of a thin plate by 
 observing the flow through a measured orifice. For instance, in some 
 observations upon the draught of air the average velocity of the air passing 
 through a circular opening three inches in diameter in a sheet of millboard 
 was found by means of an air-meter to be 8 feet per second. The area of 
 the orifice was -049 square foot, and the flow consequently "392 cubic foot 
 Ijer second. The resistance of the orifice may be calculated out to be 15"6 ; 
 whence it follows that the head required to maintain the flow through the 
 orifice is 15-6 x (-392)2, j g_ 2-4 foot-pounds per pound of air traversing the 
 orifice. Prom the considerations given in the footnote on p. 54 we see that 
 this head would imply a diflerence of pressure on the two sides of the orifice 
 which corresponds to a difference of level of "036 of an inch of water. 
 
 Extension of the theory to ducts of any length and form 
 
 17. We have hitherto only considered the motion of air through an aperture 
 in a thin plate ; but the theory may be very easily extended to any duct what- 
 ever. For if we consider the flow of air along a duct, we have losses of head 
 due to friction against the sides of the channel, to sudden bends, or to changes 
 of diameter, besides the loss due to friction on entering the duct, and possibly 
 to the contraction of the vein where the air emerges. All these account for, or 
 use up, part of the head, and the remainder alone is available for producing the 
 velocity which constitutes the flow. But, as will be seen shortly, everyone of 
 these items of expenditure of head is proportional to the square of the flow, 
 
 so that instead of equating the head to a single term -—^V^, we must equate 
 
 A la 
 
 it to the sum of a number of terms representing severally the expenditure 
 
 of head on friction, bends, changes of diameter, and finally velocity of 
 
 emergence. Each one of the terms will, however, contain V^ as a factor ; so 
 
 that the equation takes the form — 
 
 1b=(a + Z) + c-ffZ+ .... )\\ . . . (2) 
 
 where the factors a, b, c, . . . refer to the losses of head due to the several 
 causes specified. The separate terms may be calculated separately if we have 
 complete information as to the shape, size, and nature of the surface of the 
 duct ; but even if we cannot calculate them, we can see that the factors 
 a, b, c, . . . might at any rate all be added together and the sum of them 
 called E, and we get the equation in the form 
 
 1I3=RV^ (2*) 
 
 which is identical in form with that for the motion through the aperture in 
 a thin plate; only in this case we cannot calculate the value of R, or at least 
 not so easily as for the use of a thin plate aperture. But we can still speak 
 of R as the resistance of the duct, and, as in the case of a thin plate aperture, 
 it is independent of the flow ; and, moreover, we can see that different ducts 
 may have the same resistance, and may therefore be regarded as equivalent. 
 
60 HYGIENE 
 
 Of two equivalent ducts, one may be an orifice in a thin plate the area of "wbich 
 can be calculated, as we have seen, fi'om the resistance. Hence we may repre- 
 sent the resistance of a duct as the resistance of the orifice in a thin plate to 
 which it is equivalent, and if we can measure the resistance of a duct we can 
 calculate the area of the ' equivalent orifice ' in a thin plate, and in this way 
 specify the properties of the duct in regard to the transmission of air. If, for 
 instance, from any cause the resistance of a duct be increased, as by increasing 
 its length, or by a deposit of soot on its surface, we may at once represent the 
 increase by a corresponding diminution in the area of its equivalent orifice. 
 
 The definition of the resistance of a duct is identical with that for a simple 
 aperture, namely, the ratio of the head to the square of the flow. If these 
 two quantities can be measured, the resistance can be at once calculated and 
 the area of the equivalent orifice determined. We shall shortly describe 
 methods of measuring the resistance without directly determining the head, 
 and shall thus be enabled to find from such measurements the orifice to which, 
 say, a chimney is equivalent, and to compare different chimneys in respect of 
 then- resistance or equivalent orifices, and this without even so much as 
 knowing what the area, shape, or state of the chimney may be. 
 
 The idea of expressing the ' conducting power,' if we may so term it, 
 of a duct by means of the equivalent area in a thin plate is, so far as we 
 know, due to M. Murgue. It evidently enables us to render remarkably 
 precise a large mass of information that was before hazy and vague. We 
 may sum up by restating our second general laio of ventilation in terms 
 appHcable to any duct whatever, as follows. The ratio of the head to the 
 square of the flow is a constant called the resistance of the duct, which 
 depends on the size, shape, and surface of the duct, but is independent of 
 the flow, and for the purposes of transmission of air the duct is equivalent to 
 the orifice in a thin plate which has the same resistance as the duct, the 
 area of the equivalent orifice a being connected with the resistance K by the 
 1 
 
 relation K 
 
 27^2 
 
 Third and Fourth Latvs of Ventilation. Application of the first tioo Funda- 
 mental Laws of Ventilation to the Indirect Determination of the Besist- 
 ance of a Duct and of the Head producing the Floio in a given Duct. 
 
 18. We have already seen that one of the characteristic properties of a 
 duct of any shape and length is its resistance to the flow of air through it. It 
 is of great importance to the accurate study of any actual system of ventilation 
 that the resistances or equivalent orifices of its air-ducts should be known. 
 The resistance of any duct may be calculated approximately, in a manner 
 that win subsequently be described, from the measured dimensions of the 
 duct and from its shape, assuming certain experimental results as to the 
 coefficient of air-friction, and the effect of bends and other singularities 
 upon the flow of air. The calculation is, however, elaborate and tedious, and 
 in the end not very satisfactory, except, as already indicated, for the case of 
 an aperture in a thui plate, when the calculation is sufficiently simple and 
 accurate, the resistance of a thin plate aperture of area, a, being, as already 
 
 explained, ^^. 
 
 Now it is possible when a flow of air passes through a combination of 
 ducts to infer, ixom. observations of the flow merely, the relations between 
 the resistances of the several ducts ; and thus, if one of these ducts be itself 
 
WABMING AND VENTILATION 61 
 
 an aperture in a thin plate, and its resistance therefore known, the resistance 
 of the others can be calculated, without any direct measurement of their 
 dimensions. This method has been employed by M. Murgue in the work 
 already referred to for the particular case of the ventilation of mines by 
 fans ; but it seems capable of very considerable extension and very wide 
 application. 
 
 19. We shall now give three examples of it. I. As a j&rst instance we will 
 take M. Murgue's case in which we have a space, S, communicating with the 
 external air by two ducts, i and o (fig. 5), one of which, i, is a thin plate 
 aperture, and the other duct, o, of unknown 
 dimensions and resistance. We shall further 
 suppose that the area of i can be altered, as, 
 for example, by sliding shutters, indicated in 
 the figure, and can at any time be measured, 
 and thus its resistance calculated. To fix 
 ideas, S may be regarded as a fairly ample 
 fireplace, o the chimney, and i an opening in 
 a screen in front of the fireplace ; the windows 
 of the room may be supposed open. We shall 
 also assume that the flow through the two 
 ducts is maintained by a constant ^ head, H). 
 Now, referring to the phenomena described in 
 the case of the motion of air through an 
 aperture in a thin plate (p. 55), it will be Fig. 5. 
 
 noticed that air began to take part in the flow 
 
 through the aperture as soon as it got in the rapids, and we must have a 
 similar understanding with regard to the flow through the duct ; that is to 
 say, if we are to be able to apply the second law of ventilation to the motion 
 through 0, the space S must be so large that the air is practically at rest, or 
 only moving very slowly in the part between the rapids of influx at i and 
 the rapids of efflux at 0. If this condition be not satisfied the resistance of 
 the ducts will not be independent of the flow. From the want of experimental 
 data, we are unable to give the precise relation of the dimensions required 
 for any given flow. Assuming, however, that S is sufficiently large, it is 
 evident that the second law of ventilation may be appHed to the two ducts i 
 and separately. 
 
 Thus let O be the resistance of 0, 1b 1 the head between S and the top of 
 0, and V the consequent flow. 
 
 Then 1bi=f^V2 . . . p. 59, by eq. 2*. 
 
 Similarly, let A be the resistance of i, and 1b2 the head for flow through it. 
 Then 11)2 = A V^ "" 
 
 for by the first law of ventilation the flow through both ducts is the same. 
 Moreover, from the fact that the head for a duct is the work done upon 
 one pound of air flowing through it, it follows that the sum of the heads for 
 the two ducts is the whole head for the system, or 
 
 1bi+lb2 = lb 
 
 From which ^ we get ^ 
 
 lb = (A + n) V« (3) 
 
 * This would be the case with a ventilating-fan, and approximately so with a fire- 
 draught, but not strictly so in that and some other cases. If, however, the alteration of 
 head can be calculated, this does not affect the principle of the method under consideration. 
 
 - Or, in words, the sum of the resistances of two separate ducts is the resistance of the 
 whole, regarded as a single duct. 
 
62 HYGIENE 
 
 But further, suppose that the area of I is altered hy sliding the shutters 
 so that its resistance becomes A' and the flow through the system V'. 
 
 Then, since lb remains the same, we get another equation similar to (3), 
 
 t) = (A' + fi) V'2 ; 
 whence (A + fi) V^ = (A' + O) V'^ 
 
 But V and V can be measured by the air-meter described below, and 
 hence may be regarded as known quantities, and so are the resistances A and 
 A' ; and consequently we can calculate the value of O, for it is 
 
 A' y''' - A Y^ 
 equal to — ■ y2 _ y/2 — 
 
 It is also evident that when fi has been thus determined, the head lb and 
 the partial heads Ibi and flDa can likewise be calculated, and thus all the 
 elements of the system of ventilation deduced, from observations of the 
 measurement of flow and the area of the adjustable aperture in the thin 
 plate denoted by i in the figure. The resistance of the duct o being thus 
 determined, the area of its equivalent orifice is easily deduced by the equa- 
 tion of p. 58. 
 
 As an example of the calculation of the resistance and equivalent orifice 
 of a chimney by this method, we may quote from some observations made 
 upon a chimney in the Cavendish Laboratory, Cambridge. The chimney has no 
 firegrate, but gas was burned in it to produce a head ; the front was covered 
 by a wooden screen, and the openings denoted by i were represented by circular 
 areas cut in millboard. Two of the observations were as follows : 
 Area of i -098 sq. ft. Flow -842 cub. ft. per sec. 
 „ i' -294 sq. ft. Flow 1-G2 cub. ft. per sec. 
 
 From which we obtain 
 
 resistance of chimney = '88 
 equivalent orifice = "205 sq. ft. 
 
 The actual area of section of the chimney at the lowest part is "875 
 sq. ft., so that the friction of air against the sides, and bends in the chimney 
 reduce the effective area to about one quarter of the measured cross-section. 
 From the same results we get — 
 
 The total head •lb=6'6 foot-pounds per pound of air, which is approxi- 
 mately equivalent to a pressure of 
 I one-tenth of an inch of water ; and 
 
 ^ the partial heads 1b i and 1b2 can be 
 
 similarly determined. 
 
 II. The next example of the 
 application of this method is but a 
 slight modification of the former, 
 and is represented by fig. 6. In 
 this we have three ducts, represented 
 by 0, i, and a respectively, of which 
 
 .> -s ^ 1 the adjustable opening i separates 
 
 Y the space previously denoted by S 
 
 into two parts, Si and S2, and the 
 duct a may be taken to represent 
 the chinks of windows and doors 
 in the absence of a special inlet. If now each of these spaces be sufficiently 
 large for the interference of the respective ' rapids ' to be disregarded, we 
 may again treat each duct separately, and, regarding the total head fl? as 
 
 s, \ s 
 
 Fig. 6. 
 
WABMING AND VENTILATION 
 
 63 
 
 D 
 
 constant, and made up of the three partial heads 1b i, lb;., lbs, the resistance 
 of the ducts being i2, I, and A, we have — 
 
 1bi=iiV,2 
 
 1b2=rV,^ 
 
 1b3=AV,'^ 
 
 V, being the measured flow expressed in cubic feet per second. From these 
 three equations we get 
 
 1bi+1b2 + 1b3=1b=(^ + I + A)V,'^ . . . (4) 
 
 or the equivalent resistance of the whole system is again the sum of the 
 resistance of its three parts. By altering the adjustable opening to i' we get 
 another equation-^ 
 
 1b=(^+I' + A) V2^ (5) 
 
 where Vo is the flow observed in the second case. 
 
 These two equations enable us to find, not^ and A separately, but il + A. 
 N«w if A represents the resistance of the chinks 
 &c. by which the air finds its way to the chimney 
 when the window and doors are shut, A may 
 be abolished altogether by setting the window 
 wide open, and il determined as in the first ex- 
 ample; then, having found ii and i2+ A, we can 
 determine A, the resistance of the chinks. 
 
 III. The third example of the indirect method 
 of determining the resistance of ducts is repre- 
 sented in fig. 7, and illustrates the case of what 
 may be called parallel orifices. In this case three 
 ducts, 0, i, a, all open directly into the space S. 
 
 We have drawn the duct a horizontal in 
 order to indicate that no head is produced by 
 it, as might be the case if it were vertical and 
 there were any temperature differences. We may 
 accordingly assume that the head is the same for the two ducts i and a, and, 
 supposing that the whole head 1b is made up of the partial heads Ibi and 
 Ibs) and that O, A, and I represent resistances, we get the following equations : 
 
 lbi=iiVi2 
 
 1b2=I^i'=A^;2' 
 
 where Vi and V2 are the parts of the whole flow Vi passing through i and a 
 respectively. 
 
 But by our first general law 
 
 hence \/l^4 7! + ix } = ^^ 
 
 s 
 
 Pig 7, 
 
 or 
 
 1b2 = 
 
 T )> Vi^ . 
 
 Whence we ffet 
 
 
 («) 
 
 (7) 
 
6-1 HYGIENE 
 
 Equation (7) represents the relation between H), fl, I, A, and V, of which I 
 and V, are known. If the area of i be altered, a fresh equation is obtained, 
 and so by determining the flow corresponding to three separate values of the 
 area i, we obtain three equations from which we can determine the resistance 
 of the ducts A and 12 and the total and partial heads. 
 
 This example illustrates a practical method of determining the resistance 
 of the chinks in doors and windows by providing an additional adjustable 
 and measurable aperture. It is, however, liable to serious disturbance from 
 the effects of wind. 
 
 It should be noticed that equation (6) is an example of a general law, 
 easily proved on the same line of reasoning, viz. : — 
 
 LA W 3. That when two or more ducts are parallel and themselves produce 
 no head, their effect is the same as that of a single duct whose equiva- 
 lent orifice is equal to the sum of the equivalent orifices of the separate 
 ducts. 
 
 We have already seen in the two previous examples instances of the ap- 
 plication of the law holding in the case of the ducts through which air flows 
 successively, or ducts ' in series,' as they may be called for the sake of clear- 
 ness. We repeat it here as — 
 
 LA W 4. The resistance of any number of ducts in series is the sum of the 
 resistances of the separate ducts, provision being taken for the non-interference 
 of their rapids. 
 
 In a subsequent chapter we shall endeavour to show how these four laws 
 can be applied to the explanation of some important problems in ven- 
 tilation. 
 
 Calculation of the Resistance of an Air -duct from its Shape and 
 
 Dimensions 
 
 20. In the previous section we have shown how the resistance of an air- 
 duct can be determined indirectly by a method which practically compares the 
 resistance of the duct with that of a measured aperture in a thin plate ; 
 we now proceed to consider the calculation of the resistance, by means of 
 tabulated data, from the specification of the shape and dimensions of the duct, 
 and the nature of the materials of which it is constructed. As the basis of 
 calculation we take the results of experiments upon the flow of air through 
 ducts of measured size and shape, principally derived from Peclet's ' Traite de 
 la Chaleur,' vol. i. 
 
 The practical difference between the two methods amounts to this — that 
 in order to employ the former the duct must have been actually constructed, 
 whereas for the latter we require only the architect's specification of the 
 work for it ; and therefore it follows that, while the former method is the 
 one most easily applicable, and probably most accurate, for the purpose of 
 criticising a system of ventilation already in existence, and in correcting the 
 data employed in and checking the results predicted by the latter method, 
 this latter must be solely relied upon in designing a system of ventilation 
 to satisfy certain specified requirements. We have already seen that we can 
 express the motive force which propels or draws the air along a duct by 
 specifying the head, that is, the amount of work which is required to be 
 done upon each pound of air during its passage ; and we have also remarked 
 that, in the case of any duct, part only of this work is spent in producing the 
 velocity with which the air traverses the duct, and the rest is wasted in 
 friction in various ways, and we have represented the relation between the 
 head lb, and the flow V, by an equation (p. 59) 1[3=(a.-t-&-f c-f-fZ + ...) V,- 
 when the factors a, b, c, ... refer to the waste of head by friction in the 
 
WARMING AND VENTILATION 
 
 65 
 
 various ways. We now wish to justify this equation and to express the 
 various losses of head in terms of the dimensions of the duct.^ 
 
 In order to fix our ideas as to the elements which have to be considered in 
 the problem, let us represent by A B C D E F (fig. 8) the duct employed 
 to convey air from the space R to the space ; and let us suppose that, under 
 the action of a head lb, V cubic feet of air enter the duct at A every second. 
 If we can neglect changes in the density of the air, the flow as measured in 
 cubic feet across every transverse section will be the same. 
 
 Let us examine a little more closely the motion of the air in the various 
 sections of the duct, so that we may appreciate the various causes of waste of 
 energy. As the air prepares to leave the space E, rapids are formed about 
 the opening A, and the lines of motion oi the air converge and cause a con- 
 traction of the effective orifice. A short distance withm the tube A B, the 
 jet of air reaches its minimum section, and the motion is parallel to the sides 
 of the tube. From this section the jet gradually expands until it fills the whole 
 tube at the section x. 
 
 From the orifice A to the section x the jet of moving air occupies only a 
 portion of the cross-section of the duct ; the rest is occupied by air which is 
 
 Fig. 8. 
 
 maintained in a continual state of whirling or eddying motion by the friction 
 with the undefined boundary of the moving jet. The friction of the eddies pro- 
 duces heat, and here we have, therefore, the first portion of energy wasted, viz. 
 that which is converted into heat in the rapids and eddies about the orifice A. 
 
 From X to near B, the motion of the air is parallel to the sides of the 
 duct, and here there is loss, due to the friction of the air against the sides. 
 Work is again spent in the friction and converted into heat. For the sake 
 of clearness we distinguish this loss as loss by air-friction, although it may 
 not be really different in its nature from the loss in the rapids ; it depends, 
 however, on the nature of the surface and on the length and internal girth 
 of a straight duct. It is, moreover, distinct, in the sense that it is quite un- 
 avoidable, for we cannot have a duct without sides, whereas we can avoid 
 abrupt changes of shape and abrupt bends. 
 
 The air is now supposed to have reached the rectangular bend B where 
 it has to change the direction of its motion ; but its inertia causes it to 
 impinge upon the further side of the portion B C, and another contraction 
 of the jet takes place, leaving a portion of the area occupied by eddies, and 
 likewise the part in the angle at B. After the contraction, which takes place 
 
 ' For full details of this part of the subject see Peclet, Traite de la Chaleiir, vol. i. 
 1878 ; or Morin, Etudes sur la Ventilation, vol. i. chap. iv. 1863. 
 
 VOL. I. F 
 
eS HYGIENE 
 
 just after passing the angle, the jet again spreads out and fills the tube 
 at some section y. Again we have a loss of energy in the friction of the 
 eddies, which we may call the loss of energy due to a rectangular bend in 
 the duct. From the section y the motion is again parallel to the sides of 
 the duct, and the air passes on, losing energy only by friction, imtil the curved 
 bend C is reached, on the further side of which we have another contraction 
 of the jet and fui'ther loss in eddies. We need not continue the minute 
 description of the motion ; there will be losses of energy in eddies at D 
 when the area of the duct is suddenly increased at E, when the area is 
 suddenly diminished, and eddies are also produced at the orifice of emergence 
 F, between the issuing jet and the surrounding air. Finally, the air issues 
 from the orifice at F with a velocity which can be calculated from the flow 
 and the area. The work which is required for all these operations is 
 derived from the agent (engine or furnace chimney) which maintains the 
 head. Hence we may suppose work done in maintaining the head as dis- 
 tributed into the following items : — 
 
 a. Work spent in friction of eddies at orifice of entry. 
 
 b. ,, ,, ,, a rectangular bend. 
 
 c. „ ,, „ a curved bend. 
 
 d. „ „ „ a sudden enlargement. 
 
 e. „ „ „ a sudden contraction. 
 
 f. „ ,, ,, at orifice of exit. 
 
 g. „ ,, against the sides of the duct when the section 
 
 is uniform. 
 h. „ generation of the velocity of the air at the orifice 
 
 of exit. 
 
 If we can express the work spent in each one of these items corresponding 
 to the flow of 1 lb. of air thiough the duct, we may take the head as numeri- 
 cally equal to the sum of the separate items. 
 
 It must of course be understood that the duct we have described, although 
 it contains a number of points of interest, is still, comparatively speaking, 
 regular in form, and is only an approximate representation of a real duct. 
 
 Let us now consider the magnitudes of the difi'erent items — 
 [a) Loss of head at orifice of entry 
 
 This, for unit weight of air passing, can be expressed by slightly altering 
 
 1 /I \ V^ 
 
 a formula^ of M. Peclet (op. cit. vol. i. p. 154), as - — -— - ( — ^ — 1 ) — 
 ^ -^ ^ 2 X 32*2 \m^ J a^' 
 
 where V is the flow in cubic feet per second,^ a the area of the section, and 
 
 m is the coefficient of contraction of the orifice wbich has the value '728 
 
 when the duct is as drawn in the figure. The coefficient depends on the form 
 
 of the orifice. By making the entrance into the duct trumpet- shaped, the 
 
 loss under this head can be entirely avoided.'* 
 
 ' We have expressed the losses throughout in terms of the square of the flow. 
 M. Peclet expresses them in terms of a quantity jj, which is related to the air-velocityt;, by 
 the equation v = 'J'lg-p. 
 
 - To avoid complexity, we shall assume the air to remain of the same density through- 
 out the duct. If this assumption be not admissible, the losses under the different heads 
 should be expressed in terms of the locight W of air flowing per second ; the formula in this 
 
 case becomes ^— ~ 1^ — > ^ being the density of the air at the section referred 
 
 2 X 32-2 \m- / -A- 
 
 to. Corresponding changes would be required in each successive item. 
 
 3 For the effect of different-shaped mouthpieces, see Peclet, vol. i. chap. iv. 
 
WABMING AND VENTILATION 
 
 07 
 
 (b), (c) Losses at bends 
 
 For bends made by the junction of two straight tubes, Peclet {op. cit. vol. i. 
 
 1 V^ 
 
 p. 209) gives the formula - — — — - sin^i.— - when i is the angle between 
 
 2Xo2'2 a^ 
 
 The formula ^ 
 
 2x32-2 
 the two consecutive portions of the duct as indicated in fig. 9. 
 is applicable to angles between 20° and 90°. For still larger angles, the proper 
 value of the loss of head is uncertain ; for smaller angles, the bend may bo 
 
 a> - : > 
 
 Fig. 9. 
 
 V ii* 
 
 Fig. 10. 
 
 Fig. 11. 
 
 Fig. 12. 
 
 For such Peclet saya 
 X -.- is satisfactorily 
 
 more accurately treated as if it were a curved bend. 
 
 i° 1 
 
 that the formula for the loss of head — --- x - — — - 
 
 180° 2 X 32-2 
 
 confirmed by experiment, i° being the angle through which the duct is bent 
 
 from the continuation of its original direction, as shown in fig. 10. Comparing 
 
 the formulae for angular and curved bends, it appears that for the same flow 
 
 the loss of head for a curved bend of 180°, as in fig. 11, is only one half of 
 
 that for the same flow with two rectangular bends, as in fig. 12, producing 
 
 the same effect in respect of change of direction. 
 
 {d) Loss of head at a sudden enlargement 
 Thisis not easily expressed. Peclet (op. ci^. vol. i. chap, vii.) gives the formula 
 
 1)4 \ Y2 
 
 for cylindrical ducts (— B + 1 - .^--^ ) _ — — -„, where Di is the diameter 
 
 of the larger part, D that of the smaller part, and B is a quantity which 
 likewise depends on the ratio of the diameters and has a maximum value '47 
 when the ratio of the diameters is '6 : 1. 
 
 (e) Loss of head at a sudden contraction 
 
 This is the same as the loss which takes place at the entrance of a duct 
 provided with a cylindrical mouthpiece of greater area than that of the duct. 
 
 <?>2 ;2x32-2xa2' 
 
 ' See Parkes's Hygiene, p. 191, according to which the velocity in a bent pipe is to 
 
 that in a straight pipe as 1 : 1 + sin^9 between 0° and 90°, or 1 — : 1 between 0° and 
 
 180°. 
 
 f2 
 
 The loss may be represented by 
 
 being the area 
 
68 
 
 HYGIENE 
 
 of the narrowed portion, where </> is a contraction-coefficient varying between 
 •83 and unity as the ratio of the diameters changes fi'om -1 to 1. 
 
 (/) Loss of head at the orifice of discharge 
 When the duct terminates by a straight portion as m the figure (fig. 8), 
 there is practically no appreciable contraction of the orifice, but the flow for a 
 given head is affected by the mouthpiece with which the tube terminates. The 
 effect of different orifices is discussed by Peclet, op. cit. vol. i. p. 184. (i.) When 
 the duct is terminated by a cylindrical tube, of diameter narrower than that 
 
 of the duct, we have a loss of head ( -= —1 1 
 
 of the narrow tube, and (p is a coefficient of contraction similar to that given 
 above under [e). (ii.) When the duct is terminated by a converging conical 
 orifice, the loss of head is represented by the same formula, a being the area 
 of the narrow end of the cone. The following table gives the value of 
 
 <p and -s — 1 for different angles of the cone. 
 
 V2 , 
 
 where 
 
 '2x32-2«2 
 
 the 
 
 area 
 
 
 
 Table 
 
 IV. 
 
 
 
 Angles 
 
 Values of 
 
 Angles 
 
 Values of | 
 
 
 1 , 
 
 -' 
 
 1 ^ 
 
 
 <!> 
 
 - -1 
 
 
 -#> 
 
 r~ 
 
 0° 
 
 1-00 
 
 0-00 
 
 100 
 
 0-80 
 
 0-56 
 
 10 
 
 0-97 
 
 0-06 
 
 120 
 
 0-75 
 
 0-78 
 
 20 
 
 0-93 
 
 0-16 
 
 140 
 
 0-73 
 
 0-88 
 
 30 
 
 0-89 
 
 0-26 
 
 150 
 
 71 
 
 0-98 
 
 40 
 
 0-86 
 
 0-35 
 
 160 
 
 0-69 
 
 1-10 
 
 60 
 
 0-83 
 
 0-45 
 
 170 
 
 0-67 
 
 1-23 
 
 80 
 
 0-82 
 
 0-49 
 
 180 
 
 0-65 
 
 1-366 
 
 (iii.) When the duct ends in a divergent cone or a trumpet -shaped orifice, 
 the flow is somewhat improved, provided the angle of the cone is less than 
 50°. The maximum effect is produced when the angle of the cone is 7°. 
 Details as to the numerical values are given in Peclet, op. cit. vol. i. p. 187. 
 
 (iv.) When the orifice is covered by a grating, we have a mouthpiece whose 
 area is equal to the sum of the areas of the spaces of the grating, and 
 whose coefficient of contraction lies between the coefficient for an aperture 
 in a thin plate -65 and the coefficient for a cylindrical mouthpiece '83. 
 The effective area of a grating can be considerably increased by bevelling the 
 gratmg on the side from which the air flows. 
 
 {cj) Loss of head due to friction against the sides of a shaft 
 of uniform section 
 
 If we suppose a straight shaft made up of successive short tubes or rings, 
 Ei,Pki2,E3, E4, fig. 13, each one foot in length, the effect of the frictional 
 
 7 
 
 Fio. 1£ 
 
 resistance offered by the sides of the shaft to the flow of air along it may be 
 represented as a force acting upon the air contained in each ring and propor- 
 tional in magnitude to the area of contact, i.e. the length of the ring e, multiplied 
 
WABMING AND VENTILATION 69 
 
 by the perimeter abed, or girth, of the internal section of the shaft. For 
 a shaft of circular section, radius r, the perimeter is 27rr ; for a rectangular 
 tube, 2 (a + b). The force also depends upon the velocity of motion of the 
 air in a manner which is at present somewhat obscure. If the flow is very 
 slow, the resistance is approximately proportional to the velocity ; but, if the 
 velocity exceeds six inches per second, the relation between the force of re- 
 sistance and the velocity is more nearly represented by the assumption that 
 the frictional resistance varies as the square of the velocity. The resistance 
 may also be assumed to be proportional to the density of the moving air. 
 The force in lbs. weight acting upon a ring at which the velocity of motion 
 is V will therefore be 
 
 & 
 where S is the perimeter of the section of the shaft, 
 
 A the density of the moving air, 
 g the acceleration of gravity, 32"2 feet per second, 
 jS a constant which must be experimentally determined ; 
 
 it depends upon the nature of the surface of the shaft, being very largely 
 increased if the surface is roughened. 
 
 The work done by this force in one second is Fv foot-pounds, and this 
 corresponds to the passage of W lbs. of air ; hence the work lost in friction 
 on the passage of one pound of air through the ring, or loss of head for each 
 ring, is 
 
 Fv _ l3Sv^A V _ PSv'^Av _ /3S^^ 
 W ^ *W gvAA gk ' 
 
 where A is the area of section of the tube. 
 
 The differences of pressure which are used to produce ventilation currents 
 are so small that we may without sensible error disregard the differences 
 ■of density caused by the alteration of pressure. If we do so, the velocity 
 in a uniform shaft will be the same throughout, and hence the work 
 lost by friction will be the same for each ring ; hence if L be the length 
 of the pipe (i.e. the number of 1-foot rings) the total loss of head due to 
 friction is 
 
 __ — I i^ '^ foot-pounds per pound of air delivered. 
 
 A ^" 
 The relation •— is sometimes called the ' hydraulic mean radius ' of the 
 
 D 
 
 shaft. Denoting this by m, we have 
 
 /3Lv2 
 
 y =J 
 
 mg 
 
 The value of the coefficient /3 is of vital importance to any problem of 
 designing ventilation shafts ; but it has not yet been fully investigated. 
 Some experiments byM. Arson (see 'Encycl. Brit.' vol. xii. p. 491) tend to show 
 that for cast-iron pipes /B is not constant, but depends on the velocity of the 
 air, and the diameter of the pipe [the constant 4 there employed is related 
 to the /3 used by Morin by the equation 2/3 = C] , and for diameters between 
 1-64 feet and -164 feet varies between -00242 and -00606 for a velocity of 
 100 feet per second. M. Poncelet,^ discussing the researches of MM. 
 -Girard and D'Aubisson, assigns the value -0032 to /3. But the value of /3 
 is liable to be very greatly increased by roughness of the surface of the shaft. 
 Thus in brick shafts the projections of mortar and deposits of soot very 
 
 • Morin, Etudes sur la Ventilation, i. 181, 1863. 
 
70 HYGIENE 
 
 largely increase tlie coefficient, and in "wooden shafts the roughness of the- 
 wood and deposits of dust are similarly effective. General Morin concludes, 
 therefore, that until experiments furnish more accurate values for /?, it must 
 not be assumed to be less than "01 for a chimney-shaft. Peclet, on the other 
 hand, assigns the value "003 for the coefficient of friction. The loss of 
 
 head by fi-iction is therefore represented by the formula or' — -— — 
 
 m g m K^ g, 
 
 where V is the flow in feet per second and A the area of the section of the 
 
 duct in which the friction is produced. 
 
 (h) Finally, we have to deal with the amount of work spent in producing 
 
 the velocity of the gas. We know that the work required to produce, in a 
 
 W v^ 
 weight W, a velocity of v feet per second is — . — foot-pounds. Now if 
 
 we take that section of the orifice of exit at which the motion is parallel to 
 the sides of the duct — i.e. the end section of the duct, if, as in the figure, there 
 is no contraction, but if there be contraction, then the contracted area of 
 orifice — and if we represent tliis area by A, then if V be the flow through 
 
 this orifice in cubic feet per second, the velocity of the air issuing is — feet 
 
 A. 
 
 per second, and every pound which issues has this velocity. Hence the work 
 
 1 V^ 
 
 spent in giving the requisite velocity v to every pound is — •^-^,orthehead 
 
 AG A. 
 
 1 v^ 
 
 spent in producing velocity is -5- 'r^j where A is the final area of the 
 
 orifice. 
 
 "We have now expressed each of the items of expenditure of head in terms 
 of the square of the flow, and, referring to equation (2) of p. 59, it will be 
 found that the different terms a, b, c, d . . . are all accounted for under 
 the divisions of the section headed by the same letters respectively. In 
 order, therefore, to calculate the resistance of any given duct from its shape 
 and dimensions, we have to substitute in equation (2) the proper values for 
 a,b,c . . . as indicated under the corresponding headings, and add them 
 together in order to obtain the resistance required. 
 
 In order to form an opinion of the relative magnitude of the different 
 items representing the distribution of the energy of the head, let us introduce 
 numerical values for a shaft of circular section 100 feet long and 1 foot in 
 diameter, supposing that it has one rectangular bend and one curved bend 
 of 90° ; we will assume the coefficient of friction to be "01. 
 
 Taking the items in order : 
 
 1 / 1 12 ^\ V2 
 
 = -b X 
 
 1 / 1 "1 2 \ Y2 
 (a) Loss at orifice of entry : — — ( -^-z,\ — 1 1 o ="6 . . 
 
 (0) 
 
 No sudden changes of section. 
 
 1 V^ V- 
 
 {d) Loss at rectangular bend : -- — 
 
 64"4 
 
 a)^"e-G) 
 
 V 
 
 (e) Loss at curved bend : . — . = -o x 
 
 64-4 2 ^y ,,.,^^ 
 
 (/) Loss at exit. (None) 
 
WABMING AND VENTILATION 71 
 
 ition : - 01 x 1 00 JV^ _ Y 
 
 (Hydraulic mean radius I) i. x. 32-2 * /ttN^ — « >^ (54.4 
 
 G) '"'(jy 
 
 (^) Loss by friction : _ ^^ - 01 x 1 00 JV^ _ V^ 
 
 1 V^ V^ 
 (h) Expenditure in velocity : — — ■ . „ = — -- 
 
 Adding these together get : 
 
 fad e g h\ ya 
 IE) = l,-6 + 1 + -5 + 8 + 1; ; 
 
 11-1 X 4^2_ 
 
 «*•*© 
 
 lG-1 X TT^ 
 
 From which we see that the friction of the duct is by far the most im- 
 portant item. The resistance comes out to be -28, and the equivalent orifice 
 is therefore : 
 
 A / = 'ST square foot. 
 
 V 27 X -28 
 
 If the end of the shaft be covered with a grating, the bars and frame of which 
 occupy one-half of the area of the duct, we must include an additional term. 
 
 (under the heading/), whose magnitude is f—-l\ -—^ ^ ^j-^g^e 
 
 ^ ^ 64-4 X (^ j 
 
 Y2 
 
 <p is about '75, so that the term comes out 3 2 > ^^^ is of the same order 
 
 ''■'id 
 
 of importance as the loss by friction throughout the whole tube. 
 
 Summary of Causes available to produce Motion of Air for the pibrposes of 
 Ventilation. Calculation of Head in different Cases 
 
 21. In the preceding section we have seen that the motive power of any 
 ventilating apparatus may be numerically represented by the head produced. 
 When the head is known the calculation of the horse-power required to 
 maintain a circulation of specified amount is simple, for we have already 
 seen that the head If) is the work done in driving one pound of air through 
 the shaft ; and hence, if the apparatus is delivering W lbs. per second, the 
 work done per second is lb W foot-pounds, and, taking the conventional value 
 of a horse-power at 33,000 foot-pounds per minute, or 550 foot-pounds per 
 second, we get for the power required to maintain the ventilation If) W/550 
 horse-power. It may be more convenient to express the power in terms of 
 the volume of air delivered ; this will, of course, be different for air at 
 different temperatures and pressures, and may, therefore, be different at 
 different sections of the flow ; but if A be the density of the air at any section 
 in pounds weight per cubic foot, at which the volume delivered is ascertained, 
 and V the volume in cubic feet delivered there per second, we have W = V A , 
 and hence the horse-power required is 1b V A /550. 
 
 If R be the total resistance of the ducts which convey the air to and from 
 the room, we have from p. 59, lb = R V^. 
 
 To take a numerical instance : 3,000 ctchic feet of air per hour being the 
 
72 HYGIENE 
 
 amount required for efficient ventilation, for each person in a room, calculate 
 the Iwrse-poioer required to supply air, for 100 persons, assuming that the 
 whole head for the cir epilation is equivalent to that due to the pressure of one- 
 tenth of an inch of water. 
 
 a' 
 The head II) corresponding to the assigned pressure is — foot-pounds 
 
 120 A 
 
 per pound, p. 57, where A' is the density of water in pounds per cubic foot, 
 
 and A the density of air (remembering that for the purpose of calculation 
 
 all lengths must be expressed in feet and volumes in cubic feet), and the 
 
 flow is 300,000 cubic feet per hour, or 83-3 cubic feet per second ; the 
 
 required horse-power is, therefore, ^' "^ ^'^''^ ^ ^ , or, 62-3 x 83-3 . 
 
 ^ ^ ' 120 A X 550 120 X 550 ' 
 
 •078 H.P. 
 
 The total resistance of the ducts necessary to supply the air, with the 
 
 A / 1 
 
 given head, will be U)/ V-, which gives, — — x ■, — -- 
 ^ _ . 120a (83-3)2- 
 
 Taking the ratio of the densities of au' and water at 1 / 800, the numerical 
 
 value of the resistance becomes — — x , or -00096. 
 
 120 (83"3) 
 
 Assuming, further, that the resistance of inlets and outlets is the same, we 
 
 get the resistance of each -00048, from which we calculate the area a of the 
 
 equivalent orifice of the inlets or outlets respectively to be (by the formula of 
 
 p. 58): 
 
 / 1 1000 1000 f, ,, , • i 1 V 
 
 ^ = ttJ =^ — ^TT^ 7^== -v^.- = 9 sq, tt. (approximately). 
 
 ^ 27 X -00048 3x12xn/io 111 i v i'i J/ 
 
 This example shows how large the areas of inlets and outlets must be to 
 secure adequate ventilation on the usual basis of the amount of fresh air 
 required, unless the head is so great as to produce very strong currents. 
 For, if we suppose that the frictional resistance of each duct were such as 
 to reduce its equivalent orifice to half the apparent orifice, a very moderate 
 estimate, the total area of inlet orifices would be 18 square feet, and would 
 require 9 ducts, each 2 feet x 1 foot in section, and the velocity of entry 
 would then be about 4 feet per second. Such a flow is denominated in the 
 table on p. 74 ' a gentle wind.' 
 
 All apparatus for producing ventilation currents may be regarded as 
 apparatus for producing a head. We shall, therefore, now proceed to consider 
 the diflerent ways in which the head can be produced, and, as far as possible, 
 estimate numerically the head produced under given conditions. We shall 
 include the natural agents of ventilation with the artificial apparatus, in 
 order to obtain a general view of the causes which serve to produce ventila- 
 tion. We defined ventilation as the continuous replacement of air ; but, in 
 order to include a case of change of air in nearly closed spaces, such as wells, 
 closed cesspools, and such-like, we shall strain the definition and include in 
 this survey all causes of change of air, whether continuous or intermittent. 
 We shall group these causes under the following headings : 
 
 (a) Variation of harometric pressure and of temperature. Intermittent 
 ventilation of enclosures. 
 
 (h) Direct impact of wind upon an opening. 
 
 (c) Wind blowing across the orifice of a duct. Ventilation by steam- 
 jets. 
 
 (d) Head produced by ventilating -fans. 
 
 (e) Head proditced by bloioing engines. 
 
 (/) Head produced by hot air or smoke in flues. 
 
 Before going further, it may be well to remark that, as far as the motion 
 
WABMING AND VENTILATION 73 
 
 of the air in ducts is concerned, it is immaterial whether the head is produced 
 by diminishing the pressure at the exit end of the system or increasing the 
 pressure at the inlet end ; but the difference between the two cases is of 
 practical, if not of theoretical, importance. Methods of ventilation found c 1 on 
 the former plan have been called ' vacuum ' methods ; whereas those founded 
 on the latter have been called ' plenum ' methods. The practical distinction 
 is that in the 'vacuum ' methods (1) the crevices and chinks of a system act 
 as inlets, and (2) fresh air can be introduced directly from the outside ; whereas 
 in ' plenum ' methods, the crevices act as outlets, and the air must pass 
 through the machine used to compress it. There is thus a balance of advan- 
 tages of the two methods, which will be more fully discussed in a later 
 section. In the sections which immediately follow we shall not further dis- 
 tinguish between them. 
 
 (a) Variations of harometric pressure and temperature. Intermittent 
 ventilation of an enclosure 
 
 22. Air being an expansive fluid, it must be kept in any space, which may 
 for ordinary purposes be regarded as closed, by the pressure of the external 
 air upon the small openings or crevices, balancing the internal pressure, and 
 any alteration in the internal or external pressure upsetting this balance 
 causes a flow^ of air through the crevices. The balance of internal and 
 external pressure is upset by every variation of the external barometric 
 pressure or of the internal temperature. An estimate of the amount of 
 change of air produced by oscillations of pressure and temperature is very 
 easily made. A fall of pressure of 1 inch causes the abstraction of 57 cubic 
 inches of air from every cubic foot of the nearly closed space, and a rise of 
 internal temperature of V F. causes the expulsion of 3^ cubic inches. 
 Changes of air are thus effected in wells, cupboards, cases, cellars, cesspools, 
 and other places, even when they have no apparent openings. And similar 
 causes produce an expulsion of air from all soils which are porous and 
 contain a quantity of air dependent on the barometric pressure. As the air 
 which is derived from such sources may very frequently be contaminated, this 
 effect of barometric change ought not to be overlooked. It is more particu- 
 larly referred to in Sir Douglas Galton's ' Healthy Dwellings.' One of the 
 most striking of the effects attributable to this cause is the development of 
 firedamp in mines during periods of low barometric pressure, to which many 
 colliery explosions have been due. On a small scale similar developments of 
 pernicious gases may occur in every house ; and we therefore mention this 
 instance of natural ventilation with the view merely of suggesting avoidance 
 of its effects by the provision of a suitable arrangement for the artificial 
 ventilation of all such enclosures as are likely to furnish a supply of dele • 
 terious air. 
 
 {b) Wind hlotuing directly upon an opening 
 
 23. If a space has one opening which is exposed directly to the force of wind, 
 the pressure at that opening will be increased by an amount which depends 
 on the velocity of the wind, and is, indeed, approximately proportional to the 
 square of the velocity. The experiments which justify this assumption have 
 been made upon comparatively small surfaces exposed to the action of wind ; so 
 that in applying it to the case of the pressure at, for instance, an open window 
 we may perhaps be pushing the application further than is justified. But, 
 in any case, the distribution of pressure upon the irregular surface presented 
 to the wind by an ordinary house is probably so irregular that any calculation 
 of flow from the wind must necessarily be extremely rough. It may be 
 
74 
 
 HYGIENE 
 
 useful, liowever, to put the value of the pressure in numbers, as we maj 
 obtain thereby at least a rough estimate of the efficiency of the wind as a 
 ventilating agent in comparison with others. The figures in the following 
 table of the relation between the velocity of the wind and the pressure upon 
 a surface at right angles to its direction are given in Spon's ' Dictionary of 
 Engineering ' as taken from the Edinburgh Encyclopasdia. 
 
 Table V. 
 
 
 
 
 
 Equivalent 
 
 Head in 
 
 
 Telocity of 
 
 Velocity in 
 
 Pressure in 
 
 height of a 
 
 foot-pounds 
 
 Character of the wind 
 
 wind in miles 
 
 feet per 
 
 lbs. weight 
 
 column of 
 
 per pound of 
 
 
 per hour 
 
 second 
 
 per sq. foot 
 
 water in 
 inches 
 
 air trans- 
 mitted 
 
 Hardly perceiDtible . 
 
 1 
 
 1-47 
 
 •005 
 
 -0009519 
 
 ■0635 
 
 Just perceptible 
 
 •2 
 
 2-93 
 
 •020 
 
 •003806 
 
 •254 
 
 Gentle winds . . •] 
 
 3 
 
 4-40 
 
 •044 
 
 -008373 
 
 •558 
 
 4 
 
 5-87 
 
 •079 
 
 -01332 
 
 •888 
 
 5 
 
 7-33 
 
 •123 
 
 •023 
 
 1-53 
 
 Pleasant brisk gale . 
 
 10 
 
 14-67 
 
 •492 
 
 •092 
 
 6-13 
 
 Brisk gale .... 
 
 l.j 
 
 22-00 
 
 1-107 
 
 -21 
 
 14-0 
 
 Very brisk .... 
 
 20 
 
 29-33 
 
 1-968 
 
 -368 
 
 24-5 
 
 
 25 
 
 36-67 
 
 3075 
 
 -585 
 
 39^0 
 
 High -wind . . 
 
 30 
 
 44-00 
 
 4-429 
 
 -84 
 
 56^0 
 
 
 35 
 
 51-34 
 
 6-027 
 
 1-146 
 
 76^4 
 
 Very high .... 
 
 40 
 
 58-67 
 
 7-873 
 
 1-5 
 
 100 
 
 By way of illustration we may remark that according to the table the 
 head required for the example of p. 72 could have been supplied by wind 
 impinging fully on the end of the shaft with a velocity of about 7 miles 
 per hour. 
 
 We have been proceeding so far on the assumption that the wind affects 
 one end only of the ventilation system. Every space to be ventilated has, 
 however, at least two openings. A room with an open window, for instance, 
 must have other openings if the air is to pass through the room. The other 
 openings which correspond to the exit orifice of the shaft of the problem on 
 p. 72 we have assumed to be entirely free from the action of the wind. In 
 practice this will hardly be the case, and what we have really to deal with is 
 no doubt a very complicated result, namely the difference of action of the 
 wind upon the two ends of the ventilation system. If by any fortuitous, 
 combination of circumstances the effect of the wind were the same on both 
 ends, or, what comes to the same thing, if there were only one opening, the 
 effect would be merely a corresponding compression of the air in the interior, 
 provided we could leave out of account the differences of pressure at different 
 parts of the aperture, which, however, would really cause very large replace- 
 ment of air. It will, however, be instructive to consider what volume of air 
 would be introduced by a sudden change of pressure due to wind. Let us 
 take, for instance, the pressure due to 10 miles per hour, viz., approximately, 
 y'^jth inch of water. This would force through the opening, to bring the pres- 
 sure in the interior up to the external pressure, only one 4000th part of the 
 amount of air in the mterior space. It would appear, therefore, that the 
 smoking of chimneys in gusty weather could hardly be attributed to the action 
 of the wind in producing increased pressure at the chimney-top, but may be 
 due, in part at least, to the effect of the wind at the other end of the ventila- 
 tion system of which the top of the chimney is the one end. In the com- 
 plexity of air-currents that must be produced by the impact of the wind upon 
 a house, the variability of the direction and magnitude of the wind-head is. 
 not by any means surprising. 
 
WARMING AND VENTILATION 
 
 75 
 
 (c) Wind hloiving across an aperture 
 
 24. If, instead of being set at right angles to the direction of the wind, 
 the aperture is so placed that the wind can pass over it without entering the 
 duct, the effect of the wind is to diminish the air-pressure at the orifice, and 
 so produce a current in a direction opposite to that which is set up when 
 the wind impinges directly. This effect of air in motion is an instance 
 of a hydrodynamical result of considerable interest and importance, and in 
 some cases its experimental application appears at first sight paradoxical. 
 If, for example, a tube be provided with a cup-shaped mouthpiece, and a 
 wooden ball be placed in the cup of such a size that the ring of contact is 
 well within the cup, then, when a rapid current of air is driven through the 
 tube and escapes between the ball and the cup, the air-pressure in the space 
 between the ball and cup is so much diminished that the ball will hang 
 suspended from the tube as long as a sufficiently strong blast is maintained.' 
 We may illustrate the same principle in a manner which shows its applica- 
 tion to ventilation by the experiment described below. 
 
 Thus, when a current of air is driven into a room by means of a fan, as 
 
 Fig. 14. 
 
 represented in fig. 14, it might be supposed that the pressure of air in the 
 middle of the current, near the nozzle, is greater than elsewhere in the room. 
 The precise opposite is, however, the case ; the air-pressure in the current is 
 less than elsewhere, and least where the velocity is greatest. This may be 
 experimentally verified by introducing into the current one end of a tube 
 A, the other end of which dips into water which is screened from the direct 
 action of the air-current. The general plan of the experiment is represented 
 in fig. 14. The passage of the air across the mouth of the vertical tube causes 
 the water to rise slightly in the lower part of the tube, showing that the 
 pressure in the current is less than that of the air of the room. The rise 
 of liquid is exaggerated in the figure ; it is of course proportional to the 
 difference of pressure (P — p) betAveen the air in the bottle B and the 
 interior of the current. 
 
 In some rough experiments, the velocity of the air across an open tube was 
 
 ' This form of the well-known hydrodynamical paradox has recently been brought out 
 by an American firm as a scientific toy. 
 
76 
 
 BYGIENE 
 
 I 
 
 measured by means of the air-meter (p. 105), and the diminution of pressure 
 produced was determined by finding the height to which the water rose in 
 the tube, inchning the tube considerably in order to make the reading more 
 sensitive. Observations were taken with four different velocities — viz. 8-7, 
 10-8, 13"3, and 17*8 feet per second respectively. The results show a 
 dimmution of pressure at the orifice proportional to the square of the velocity 
 of the air ; and if the relation between the head H) so produced and the 
 velocity v be represented by the equation 1b = ^ v'-, the mean value of the 
 constant k deduced from the experiments is -0155. Theoretically, when the 
 velocity of air at any point in a jet is v, the head or difference of pressure, 
 expressed as the height of a column of air, between the point and a point of 
 the jet where the motion has practically ceased, is given by the formula 
 
 •jf) = ^ = '^1= -0155 v^, provided we neglect changes of density of the 
 
 2g 64*4 
 air ; so that it appears from the above experiments that the head actually 
 produced at the end of the narrow tube there used corresponds precisely 
 with the theoretical head calculated in the manner explamed above. 
 
 There seems no reason for supposing that the effect produced by wind 
 
 blowing across an orifice 
 is anything else than the 
 difference of pressure cor- 
 responding to that in the 
 interior of the jet ; and 
 it may, therefore, be 
 assumed to be the same, 
 however the orifice may 
 be placed with regard to 
 the air-current, provided 
 that it is not exposed to 
 the direct impact of the 
 air. Thus leaving out of 
 account changes in the 
 current produced by the 
 building from which the 
 duct leads, and assuming 
 that the inlet of the duct 
 is entirely protected from 
 the wind, we may repre- 
 sent (in feet) the head 1) 
 produced as '01 55^^^ where 
 V is the velocity of the 
 wind in feet per second. So 
 that, for instance, wind at 
 the rate of 15 miles an 
 hour will produce a head 
 equivalent to the pressure 
 of the eighth of an inch 
 of water. 
 
 The production of a 
 head for ventilation by 
 the motion of air over the 
 mouth of a tube is the 
 object of many extraction ventilators and cowls. A primary cause of un- 
 certainty in their action when fixed to buildings is the variability in the direc- 
 
WABMING AND VENTILATION 
 
 77 
 
 tion of wind- currents under the influence of the surfaces of the building itself. 
 Many forms of cowl have been designed to render the ventilators serviceable for 
 any direction of wind, of which there are two characteristic types — viz. those 
 with fixed vanes and those with a rotating cowl. Of the former type Boyle's 
 ventilator (fig. 15) may be regarded as a specimen ; the vanes are fixed as 
 represented in fig. 16, so that, from whatever direction the wind may come, the 
 
 Fig. 16. 
 
 Fig. 17. 
 
 motion of the air is always tangential to the opening of the shaft ; the latter 
 type may be represented by Banner's cowl (fig. 17), which sets by means of a 
 wihd-vane so that the shaft-opening which is carried round by the wind- vane 
 always faces away from the wind. In all forms of cowl the head is very 
 variable, and may be very small, and is liable to be completely over-weighted 
 by some other head. In such a case the motion of the air is reversed, and 
 the ventilator acts as an inlet (see below, p. 101). 
 
 In order to produce a current of air along a tube, a steam -jet is sometimes 
 directed along it. Thus at the Lower Moor Colliery, Oldham, ' an apparatus 
 consisting of 72 vertical pipes, 5 feet long and 7 inches in diameter, was 
 fitted to an iron frame at the top of the upcast shaft. Into each was 
 inserted a steam-pipe having a nozzle of T;\ths inch in diameter, supplied 
 with steam at 38 lbs. pressure. This rough apparatus exhausts 16,000 
 cubic feet a minute.' The forced draught of a locomotive furnace is another 
 instance of the same kind of action. The head in these cases is due to the 
 high velocity vidth which the steam issues from the nozzle, producing a con- 
 siderable lowering of pressure in the neighbourhood of the orifice. An 
 arrangement of this kind was at one time employed for the ventilation of the 
 House of Lords, but has been abandoned. The method depends upon the 
 same principle as the production of head by wind across an aperture, but we 
 are unable to give any simple plan of calculating the head produced in any 
 specified case. 
 
 (d) Head produced by Ventilating Fans 
 
 25. In order to produce a head for the ventilation of mines and large 
 buildings, a centrifugal fan is now not infrequently used. A fan-wheel is 
 formed by a number of vanes attached to an axle. When the wheel is 
 
78 
 
 HYGIENE 
 
 rotated air is carried along by the vanes in their motion ; as the particles of 
 air slip along the surface of the fan towards the tips of the vanes their 
 velocity is accelerated and they finally leave the fan-wheel with a taxigential 
 velocity closely approximating to the velocity of the tips of the vanes. Ihe 
 general result of the rotation of the fan is a motion of air from the axis to the 
 outside edge of the wheel, and a diminution of pressure near the axis is the 
 result. If the wheel revolves in the open air, the air leaves the wheel 
 tangentially at all points of the periphery, but by enclosing the fan-wheel 
 in a circular cover with openings at the axle and a tubular aperture at the 
 periphery, the' delivery of air may be made to take place along the tube, and 
 the effect of the fan is thereby considerably increased. The axis of the 
 
 wheel is placed excentrically with 
 reference to the circle which forms 
 the general outline of the cover, so 
 that the clearance between the re- 
 volving vanes and the cover gradu- 
 ally increases up to the tube of dis- 
 charge, and by this arrangement 
 part of the kinetic energy of the 
 rapid motion of the air is devoted to 
 increasing the head instead of bemg 
 wasted in producing eddies in the 
 surrounding space. Arranged in this 
 way, the fan draws air from the 
 apertures round the axle and throws 
 it out by the delivery tube. Accord- 
 ing to M. Murgue ' the most effective 
 type of fan is M. Guibal's (fig. 18), 
 the peculiarities of the most modern 
 form of which are : (1) the size of the delivery aperture can be adjusted by a 
 sliding door ; (2) the aperture is provided with a trumpet-shaped mouthpiece, 
 so that the air delivered is kept confined until its velocity is relatively small, 
 when it passes into the atmosphere ; and (3j the vanes are so shaped that 
 they are at right angles to the periphery at their tips, but tangential to the 
 circular aperture at the axle, so that the air slides on to the vanes without 
 loss of energy in eddies. The theory which M. Murgue sets forth for venti- 
 lating fans enables one to see how the efficiency of machines of different 
 types may be compared. On his view, the effective head h which a ventilating 
 fan produces diminishes as the volume of air drawn through it increases, 
 that is, as the area of the apertures is increased. The limiting value which 
 the head would reach if the areas were reduced to zero (when the fan 
 was simply mamtaining a difference of pressure between the axle and the 
 delivery tube without any air being allowed to flow through) is 1b ; the differ- 
 ence 1b - /z-, or ho, is the head required to maintain the flow through the 
 machine itself or loss of head in the machine. 
 
 According to M. Murgue, in a perfectly designed fan, working in a cover 
 by which the whole of the kinetic energy of the motion of the air on leaving 
 the vanes is collected and devoted to increasing the head, the total head 
 developed by the fan is ^c^/g, where w is the velocity of the motion of the tips 
 of the vanes — i.e. w r — where oj is the angular velocity of rotation of the fan 
 wheel, and r is the radius of the vane. But in consequence of the imper- 
 fection of the fan the head developed cannot be taken as being the full 
 
 ' Theories and Practice of Centrifugal Ventilating Macliines, translated by A. L. 
 Steavenson. 
 
WABMING AND VENTILATION 79 
 
 u"^ 
 
 theoretical value, but may be put equal to K - where K is a factor less than 
 
 unity depending on the arrangement of the fan. In a fan without cover K 
 cannot exceed -5. The value of K is one important element in the specifica^ 
 tion of the efficiency of a fan, and can only be determined indirectly by 
 experiments, as we shall show. 
 
 We have already seen that the flow of air through a mine, or a ventilating- 
 shaft, or a machine, can be represented by the flow of air through an orifice in 
 a thin plate if the area of the orifice be properly chosen. Thus, if the ventilat- 
 ing shaft be equivalent to an orifice, area a, in a thin plate, and Jl be the head 
 required to maintain a flow of air at the rate of V cubic feet per second, we 
 have 
 
 Y = -65as/2gh 
 
 '65 being the coefficient of contraction on 1 I 
 
 passing through the orifice. Now if we I I 
 
 represent the motion of air through a o «- < — 
 
 ventilating-shaft as a flow through an 1 1 
 
 equivalent orifice, a (fig. 19), and the I j 
 
 motion through the fan as flow through ^^°- ^^■ 
 
 an equivalent orifice, o, we get, if Jiq is the head required for the second 
 
 orifice, 
 
 V = -65 s/2gho 
 
 The value of /z-o, the loss of head on passing through the fan, is the second 
 important element in the determination of the efficiency of a fan. When we 
 look into the matter further we shall see that the value of h^ depends also upon 
 the flow of air ; and this, as we have already seen, depends on the resistance 
 offered to the motion of the air through the mine or shaft, and hence upon 
 the area of the orifice a, in a thin plate, which offers the same resistance to 
 the motion. In order, therefore, to test the efficiency of a fan, we must be 
 able to observe its effect when applied to draw air through different equivalent 
 orifices. We may secure this by making the fan draw air, not through an 
 actual mine or ventilation system, but into a chamber through an orifice the 
 size of which can be adjusted to any required magnitude, each different size 
 of orifice representing a different system. We are able to observe (i.) the velocity 
 of air delivered by the fan, and hence the rate of flow, V ; (ii.) the area of the 
 equivalent orifice a ; (iii.) the effective head h (the difference of pressure in 
 lbs. weight per square foot between the air in the chamber and outside divided 
 by the density of air) ; (iv.) the velocity of the tips of the vanes, u. Con- 
 necting these quantities, we have the following equations : — 
 
 whence 
 
 v = 
 
 •65a s/2gh 
 
 h = 
 
 •65 s/2ghQ 
 h + ho 
 
 9 
 
 V = -65 
 
 
 From observations of the magnitudes enumerated above the value of o 
 can be found for the machine, and thence the value of K determined, as 
 
80 
 
 HYGIENE 
 
 likewise the values of ho and h for the different values of the equivalent 
 orifice a. ^^'Llen these have been determined, the values of h and V can be 
 represented on a diagram by curves, of whicli the ordinates are h and V re- 
 spectively and abscissiB a, !Such curves are called characteristic curves for the 
 fan, as suggested by the Commission on Ventilation of the district of Gard. 
 M. Murgue adds a table of the value of K (sometimes determined only to a 
 rough approximation), deduced from the published observations upon fans of 
 various descriptions. The values vary between -1 for some machines without 
 cover to "7 for machines of the improved Guibal type. The best machines, 
 therefore, produce a head three-quarters of the maximum possible. 
 
 26. Another method of producing by mechanical means a head for ventila- 
 tion is the rotation of a wheel with inclined vanes, by which the air is 
 made to pass transversely through the wheel parallel to the axis of rotation. 
 The action in this case is the direct converse of the action of a windmill, 
 and practically amounts to driving the windmill in order to produce a wind. 
 These machines during a revolution cut off a portion of the air from the 
 one side of the wheel and transfer it through the wheel, the relative motion 
 being, roughly speaking, similar to that produced by the action of a screw. In 
 some forms the vanes are helicoidal, when the analogy is still closer. M. 
 Murgue discusses the theory of these machines in the work already quoted, 
 and classifies them as woi'king by direct impulsion. The formulae arrived at 
 are identical in form with those given for centrifugal machines. For those 
 discussed by M. Murgue the coefficient K varies between -05 and "2, so that 
 they are much less efficient in producing head than the centrifugal machines ; 
 but for ventilations requiring a large supply of air at no considerable head 
 they may be as effective. 
 
 The form which has been frequently applied to the ventilation of buildings 
 is Blackman's air propeller^ a sketch of which is given in fig. 20. According 
 
 to the statement of the company supply 
 ing it, it gives about 12,000 cubic feet per 
 minute per horse-power for the largest size, 
 and about 6,000 cubic feet per minute per 
 horse-power for the smaller sizes ; but we 
 may presume that in this case the only 
 resistance that is contemplated is that 
 offered by the machine itself, and the 
 amount of air supplied through the ducts 
 of any ventilation system will depend upon 
 the resistance of the ducts as well as that 
 of the machine, just as in the case of the 
 centrifugal fan ; and the essential charac- 
 teristics of the fan can only be determined 
 by the experimental method indicated 
 above. 
 
 in the matter of ventilation by fans is 
 the question of the mechanical efficiency of the apparatus. The power used 
 in discharging V cubic feet of air per second from a head If) is 1b V A foot- 
 pounds per second, where A is the density of the air supplied. In calculating 
 the mechanical efficiency of fans and other ventilating machines, M. Murgue 
 substitutes for 1[5 the theoretical head of the machine and not the effec- 
 tive head h, thereby including in the useful work of the machine that spent 
 in forcing the air through the machine itself. Comparing on this assumption 
 different ventilating-machines, he obtains the foUowmg results for the ratio 
 of useful work done to work supplied to the machine. 
 
 Fig. 20. 
 
 An important consideration 
 
WABMING AND VENTILATION 
 
 81 
 
 Mean mechanical eflSciency of ventilation by direct impulsion ' . , . . -260 
 ,, „ ,, „ centrifugal force, without cover . . -278 
 
 „ „ „ „ with cover and chimney . . . -467 
 
 (e) Head produced by blowing machines 
 27. A number of machines have been designed and used for supplying an 
 air-blast to furnaces, and for ventilation, the principle of which is widely dif- 
 ferent from that of the machines which have hitherto been discussed. The 
 simplest type may be represented as an air-pump or bellows driven by the 
 piston of a steam-cylinder. The air-pump is simply a barrel with two valves, 
 one opening outwards, the other inwards, with a piston sliding in the barrel. 
 As the piston moves backwards and forwards the valves alternately open and 
 shut, and the air is drawn in at one valve and forced out at the other. The 
 barrel of the air-pump may be made as large as we please — provided we have 
 power to drive it — and by arranging it like the cylinder of a steam-engine a 
 delivery of air may be secured both by the back and forward stroke ; and with 
 several pumps on the same crank, each delivering into an air-chamber from 
 which outlets proceed for the distribution of the air, a steady flow through the 
 ventilation system may be obtained. Drawings and particulars of various 
 blowing machines are given in the supplement to Spon's ' Dictionary of Engin- 
 eering ' (art. Blowing -machine), and a form specially designed for ventilation 
 by Cunningham is mentioned in the article * Ventilation ' in the ' Encyclo- 
 paedia Britannica.' One source of loss of energy in the working of these 
 machines lies in the fact that the motion of the piston has to be reversed with 
 every stroke, and however light the piston may be made its mass is large com- 
 pared with the mass of air to be moved. The loss Inay be reduced by special 
 design of the machine which drives the piston, but cannot be entirely obviated, 
 so that for the purposes of producing a current of air a rotary piston seems 
 much more suitable. Boots' 
 blower, fig, 21, is a machine 
 which is worked by rotating 
 pistons. Two pistons, each 
 shaped like a figure of 8, are 
 worked on parallel axles in a 
 box with two openings ; the 
 box is formed of two half cy- 
 linders separated by two flat 
 portions, and in these two flat 
 portions the holes for entry 
 and delivery are made. As the 
 pistons rotate the air is driven 
 through the apparatus, Cun- 
 ningham has also modified 
 this machine for ventilation. 
 In all machines of the 
 air-pump or rotary piston 
 type it is evident that a de- 
 finite volume of air is trans- 
 mitted at each stroke. When 
 this volume is known — and it 
 may be calculated from the 
 dimensions of the machine— the volume V of air transmitted per second is 
 known from the speed of revolution, and whatever head is needed to drive that 
 
 VOL, I. 
 
 See above, p. 80. 
 
82 HYGIENE 
 
 volume will be supplied fi-om tlie source of power which drives the fan. A 
 machine of this description can therefore be tested by replacing the ventilation 
 system by an orifice in the air-chamber whose area is known, and calculating 
 the bead required from the formula, 
 
 *=-'^°''-v/^"' 
 
 and measuring V for a given speed of rotation. 
 
 The work done per second is V 1l3 A, and if we measure the power required 
 to drive the machine we get the efficiency, as the ratio of the effective work 
 per second to the whole power required to drive the fan. 
 
 (/) Head produced in hot-air and smoke flues 
 28. In the case of a vertical hot-air flue we can calculate the head in the 
 following manner. The hot air rises because its density is less than the density 
 of the air surrounding the flue. Let us suppose the density of the air in the 
 flue to be uniform throughout the flue and equal to A' lbs. per cubic foot, and 
 the density of the air surrounding the flue to be Hkewise uniform and equal 
 to A lbs. per cubic foot. Then every cubic foot of volume of air in the flue 
 will be acted upon by a force equal to the weight of ( A — A') lbs., and hence 
 the total force on the air in the flue is (A — A') A H pounds weight, where 
 A is the area of the flue and H its height. If the air is passing up the flue 
 at velocity v feet per second (A — A'), A Hv foot-pounds of work per second 
 will be done by the force. But this corresponds to the delivery oi Av A' 
 pounds of air ; hence the head, or work- equivalent of the flue per pound of air, 
 • A — A'tt 
 
 is ; — H. 
 
 A' 
 
 We notice about this expression that the head depends merely upon the 
 density of the air inside and outside, and upon the vertical height of the flue. 
 Though we made use of the area of the flue in the calculation, it has disap- 
 peared from the result, and we may rightly conclude that, provided the density 
 of the air is the same throughout, the head will not depend upon the area, 
 shape, or size of the flue, but merely upon the difference of level of the open- 
 ing at the top and bottom. There may be any number of bends and con- 
 strictions and horizontal portions : these affect the resistance ; they do not 
 affect the head, except possibly indirectly, by altering the distribution of tem- 
 perature and thereby the density of the air. 
 
 The difference of density is produced by raising the temperature of the 
 air in the flue above that of the outside air either by supplying heat to the 
 air as it passes into the flue at the bottom, as in an ordmary chimney, or by 
 supplying heat to the air of the space to be ventilated and letting the air so 
 heated pass into the flue, as in the case of an ordinary ventilation flue un- 
 provided with any special supply of heat. 
 
 As the temperature of the air in the flue is much more easUy measured 
 than the density, we will express the head in terms of the temperature. We 
 have already (§ 8) explained how the density may be calculated from the 
 temperature. If T be the temperature of the air in the flue, and t that 
 
 of the external air, in Fahrenheit degrees, — =-rz^T — fhj 
 
 A 459 -fT 
 
 whence we find the head, 
 
 *=J9"> W 
 
 The head is therefore proportional to the difference of temperature of the in- 
 ternal and external air, and the flow will be upwards if the internal temperature 
 is greater than the external, but downwards if the reverse is the case. For the 
 
WABMING AND VENTILATION 83 
 
 purposes of accurate calculation the external temperature should be measured, 
 but for very rough computation we shall not be far wrong if we assume the 
 external temperature to be always at 41° F. and the head of a hot-air flue to 
 be therefore 5-oirth part of the product of the difference of internal and external 
 temperatures, and the difference of level of the top and bottom openings. 
 
 It follows from this calculation that any variation in the temperature of 
 the air contained in a chimney will cause a change in the ventilation head ; 
 now the temperature in the chimney will fall if the flow of cold air into it be 
 increased by diminishing the resistance of the inlet ducts. The head is 
 therefore, strictly speaking, not independent of the flow, although it may be 
 assumed to be so if the change is a very small fraction of the whole flow ; 
 thus if a large block of buildings be ventilated by one very large chimney-stack 
 the head might be assumed to have remained constant, although the resistance 
 of the entry inlets of one room had been doubled. If the shaft is long, a 
 small change in the flow will not affect the temperature very much at first, 
 for heat will be communicated from the hot sides of the chimney ; but ulti- 
 mately a permanent change in the flow will correspond to a permanent change 
 in the temperature and therefore in the head. We have been of course tacitly 
 assuming that the supply of heat has been constant ; such a condition would 
 hardly be realised with a coal fire at the foot of a chimney, but it would be so 
 if the heat were furnished by the combustion of a number of gas jets with a 
 constant supply of gas. In such a case we might be able to express the 
 head in terms of the heat-supply and the flow, which can be done as follows. 
 Let © be the amount of heat supplied per second, and let the flow of cold air 
 to the chimney be V cubic feet per second; the weight of air warmed per second 
 will be V A . It is warmed at practically constant pressure, so that the specific 
 heat is '238, and the heat used per second is '238 (T — ^)V A =0, 
 
 from which we get (by equation 8, p. 80) 
 
 a. 
 or ID 
 
 or 1bV= 
 
 238(459 -fi)V A 
 ©H 
 
 •238(459 + A* 
 
 Thus the head is inversely proportional to the flow. 
 
 Let us apply this equation to calculate roughly the head due to combus- 
 tion in a special case. 
 
 To find the Head of Air toitJi an Open Gas Fire burning 20 Cubic Feet 
 
 of Gas per hour 
 
 1 lb. of gas produces 18000 lb. F. units. 
 
 The density of coal gas is -0418 lb. per cubic foot. 
 
 The weight of gas burned is therefore equal to ^^— ^^ =-00023 lb. per 
 
 second. 
 
 T may be taken as 41° F. ; and assuming all the heat to go up the 
 chimney we have 
 
 -p^^TT ;00023xl8000_ 
 "" •238x500xVA 
 
 =^x-035. 
 
 o2 
 
84 
 
 HYGIENE 
 
 In order to determine the head we require to know the weight of air 
 passing per second, which must be determined by observation of the velocity 
 of transmission, but if the area a of the orifice to which the chimney is equi- 
 valent be known, and likewise the equivalent area a' for the inlets, we get (see 
 p.Gl) 
 
 1l3=2-35 t + 
 
 a 
 
 V2 
 
 and. if W be the weight of air delivered W=V A. 
 ^Yhence we get 
 
 j_ 2RA^g -0036 
 
 ^V3= 
 
 / 1 J^>^ 2-35 
 
 =•00050 
 
 H 
 
 -„+- 
 
 Hence for a given quantity of gas burned per hour the weight of air carried 
 up the chimney varies as the cube root of the height of the chimney, and as 
 the cube root of the square of area of the equivalent orifice if the air be allowed 
 free access to the base of the shaft, i.e. if «' may be regarded as indefinitely 
 great. This equation may be used to determine the smallest value of «', or 
 the area of the inlets, that is consistent wdth the delivery of a given weight of 
 
 Table VI. — Production of Head of given Numekical Value bx Vapjous Agents. 
 
 Head or equivalent 
 
 pressvire 
 
 Conditions necessary to produce the Head 
 
 
 
 -f. ~t: -^ 
 
 . ^ 
 
 
 
 
 
 
 O c^ 
 
 SS 
 
 
 la 
 .si 
 
 
 1P 
 
 <4-l cj 3 
 
 
 Velocity of tips 
 
 Velocity of 
 periphery of 
 
 0-2 a 
 
 42 «» 
 
 .2 '^■ 
 
 2.2 
 
 2^ 
 
 go 
 
 U Pi 
 
 <u bo 
 n'.'S 
 
 ■2 "2 ^ 
 
 •" o " 
 
 "2 ^a 
 
 o a o 
 
 ^o§ 
 
 o c-y 
 
 of vanes of 
 
 centrifugal fans, 
 
 §25 
 
 wheel of direct 
 
 impulsion fans, 
 
 §26 
 
 
 a o 
 >- o 
 
 II 
 
 u 
 
 f^ & 
 
 tua 
 
 ■3 2 » 
 
 >a 
 
 
 
 
 
 k ^ ^ 
 
 ^ ■* 
 
 
 fk 
 
 
 W ft-s 
 
 (>g 
 
 p. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Worst 
 
 Best 
 
 Worst 
 
 Best 
 
 
 
 
 •01 
 
 •052 
 
 •670 
 
 5-71 
 
 6-57 
 
 14-7 
 
 5-55 
 
 20-8 
 
 10-4 
 
 •00152 
 
 49-4 
 
 
 •02 
 
 •104 
 
 1-34 
 
 8-10 
 
 9-29 
 
 20-8 
 
 7-85 
 
 29-4 
 
 14-7 
 
 •00302 
 
 57-7 
 
 
 •03 
 
 •156 
 
 2-01 
 
 9-78 
 
 11^4 
 
 25-4 
 
 9-62 
 
 36-0 
 
 18-0 
 
 •00454 
 
 63^1 
 
 
 •04 
 
 •208 
 
 2-68 
 
 11-4 
 
 13-1 
 
 29-4 
 
 11-1 
 
 41-5 
 
 21-0 
 
 •00606 
 
 74-5 
 
 
 •05 
 
 •259 
 
 3-35 
 
 12-5 
 
 14-7 
 
 32-8 
 
 12-4 
 
 46-4 
 
 23-2 
 
 •00757 
 
 82-9 
 
 
 •06 
 
 •311 
 
 402 
 
 13-7 
 
 16-5 
 
 36-1 
 
 13-6 
 
 50-9 
 
 25-4 
 
 •00909 
 
 91-3 
 
 
 •07 
 
 •363 
 
 4-69 
 
 14-8 
 
 17-5 
 
 38-9 
 
 14-7 
 
 551 
 
 27-5 
 
 •0106 
 
 99-6 
 
 
 •08 
 
 •405 
 
 5-36 
 
 15-6 
 
 18-5 
 
 41-5 
 
 15-7 
 
 58-8 
 
 29-4 
 
 •0121 
 
 108-0 
 
 
 •09 
 
 •467 
 
 6-03 
 
 16-7 
 
 19-9 
 
 44-1 
 
 16-6 
 
 62-3 
 
 31-2 
 
 •0136 
 
 116 
 
 
 •1 
 
 •519 
 
 6-70 
 
 17-6 
 
 20-7 
 
 46-4 
 
 17-5 
 
 65-7 
 
 32-8 
 
 •0152 
 
 124 
 
 
 •2 
 
 1-04 
 
 13-4 
 
 24-8 
 
 29-4 
 
 65-7 
 
 24-8 
 
 91-8 
 
 46-4 
 
 •0302 
 
 208 
 
 
 •3 
 
 1-56 
 
 20-1 
 
 30'2 
 
 36-0 
 
 80-5 
 
 30-4 
 
 114 
 
 56-9 
 
 •0454 
 
 292 
 
 ^ 
 
 •4 
 
 2-08 
 
 26-8 
 
 34-8 
 
 41-5 
 
 92-9 
 
 35-1 
 
 131 
 
 65-7 
 
 •0606 
 
 376 
 
 a 
 
 •5 
 
 2-59 
 
 33-5 
 
 38-8 
 
 46-4 
 
 104 
 
 39-3 
 
 147 
 
 73-4 
 
 •0757 
 
 460 
 
 .^ 
 
 •6 
 
 311 
 
 40-2 
 
 42-4 
 
 50-9 
 
 114 
 
 43-0 
 
 161 
 
 80-5 
 
 •0909 
 
 544 
 
 a 
 
 •7 
 
 3-63 
 
 46-9 
 
 45-8 
 
 54-9 
 
 123 
 
 46-4 
 
 175 
 
 86-9 
 
 •106 
 
 627 
 
 3 
 
 •8 
 
 4-05 
 
 53-6 
 
 48-3 
 
 58-6 
 
 134 
 
 49-7 
 
 186 
 
 92-9 
 
 •121 
 
 711 
 
 a 
 1— ( 
 
 •9 
 
 4-67 
 
 60-3 
 
 51-8 
 
 63-5 
 
 139 
 
 52-7 
 
 197 
 
 98-5 
 
 •136 
 
 795' 
 
 1 
 
 1 
 
 519 
 
 67 
 
 54-5 
 
 65-6 
 
 147 
 
 55-5 
 
 208 
 
 104 
 
 •152 
 
 879 
 
 1 
 
 2 
 
 10-4 
 
 134 
 
 76-6 
 
 92-9 
 
 208 
 
 78-7 
 
 290 
 
 147 
 
 •302 
 
 1720 
 
 
 3 
 
 15^6 
 
 201 
 
 93-4 
 
 113-8 
 
 254 
 
 96-2 
 
 360 
 
 180 
 
 •454 
 
 2550 
 
 
 4 
 
 20-8 
 
 268 
 
 109 
 
 131-4 
 
 294 
 
 111 
 
 415 
 
 208 
 
 •606 
 
 3350 
 
 
 5 
 
 25-9 
 
 335 
 
 120 
 
 147 
 
 328 
 
 124 
 
 464 
 
 232 
 
 •757 
 
 4230 
 
 
 6 
 
 31^1 
 
 402 
 
 131 
 
 165 
 
 361 
 
 136 
 
 509 
 
 254 
 
 •909 
 
 5070 
 
 
 7 
 
 36-3 
 
 469 
 
 142 
 
 175 
 
 389 
 
 147 
 
 551 
 
 275 
 
 1-06 
 
 5900 
 
 
 8 
 
 40-5 
 
 536 
 
 150 
 
 185 
 
 415 
 
 157 
 
 587 
 
 294 
 
 1-21 
 
 6700 
 
 
 9 
 
 46-7 
 
 603 
 
 160 
 
 190 
 
 441 
 
 166 
 
 623 
 
 312 
 
 1-36 
 
 7600 
 
 
 10 
 
 51^9 
 
 670 
 
 169 
 
 208 
 
 464 
 
 175 
 
 656 
 
 328 
 
 1-52 
 
 8400 
 
 
 ' Neglecting work wasted in the engine itself. - External air assumed to be at 41° F. 
 ' Beyond this point the numbers have no practical value for a 40-foot shaft. 
 
WABMING AND VENTILATION 85 
 
 air per second through a shaft of known height in which a given quantity of 
 gas is burning. 
 
 Having now given an account of the various means by Avhich a head can 
 be produced, we give on the preceding page a comparative table of the nume- 
 rical results produced by the different agents. "We shall so frequently employ 
 both * foot-pounds per pound ' and equivalent water-pressure to express the 
 head that we have thought well to include in the preceding table the numerical 
 expression of head in both manners, assuming that the air delivered is 
 half saturated and at 50° F. and 30 inches of mercury. 
 
 Local Cieculation 
 
 29. We have now completed our discussion of the general circulation of air 
 in a ventilation system, and have confined our attention to the motion in the 
 ■ducts, where the general direction of the motion across the whole section of 
 the duct is along the sides ; we have now to consider the motion of the air in 
 the space which the ducts are intended to ventilate. In that space the air 
 which enters by the inlets makes its way by a more or less devious course to 
 the outlets ; if our knowledge were complete we ought to be able to predict 
 the exact path which the air would take through the room from the inlet to the 
 outlet, although it might be extremely involved and complicated ; but, as we 
 have already said, in all ordinary cases the air of a room is thrown by local 
 sources of heat and other causes of motion into a state of really inde- 
 scribable turmoil, and taken in detail the motion is unsteady and incalculable. 
 All that we can do by way of calculation is to lay down some general principles 
 which govern the circulation of air in the ventilated space, or local circulation, 
 as we have called it. Experimentally we can do on a small scale what is 
 habitually done on a large scale by meteorologists, and determine at any 
 instant the direction and force of the wind at any particular point of the 
 room, and, just as they do, we can lay down upon a chart an arrow which, by 
 the way it points, shows the direction of motion of the air, and, by some 
 convention as to the character of the arrows, indicate the force. But here 
 we meet with a considerable difficulty both in the matter of experimental 
 :determination and of diagrammatic representation too. Meteorologists, as a 
 .rule, deal only with the horizontal motion and effect of wind, whereas with 
 Tis the vertical motion is at least as important as the horizontal, so that we 
 ought to be able to set our arrow in any direction whatever, and we really 
 want a solid model for the purposes of representation. 
 
 "We must, however, be content with a very incomplete and partial inves- 
 tigation of the local circulation, and represent the motion in horizontal or 
 vertical sections. It will be seen that if we could have a sufficient number 
 of direction -arrows arranged, the one to follow the other, we should be able 
 to start from the outlet and ultimately arrive at the inlet, and, assuming 
 that the motion in any particular part of the room has remained the same 
 throughout the course of the investigation, we should be able to construct 
 a curved line from the inlet to the outlet, which would indicate the direction 
 ■of motion of the air at any point of its length. Such a line would be called 
 ,a ' stream-line,' and a complete set of stream-lines would give a complete 
 account of the motion of the air from inlets to outlets, provided that the 
 motion were steady. At the inlet itself the stream-lines would evidently 
 join on to the lines of flow of the air in the duct. 
 
 But when an air current enters a room there is a gradual interchange of 
 individual particles between the air in the stream and the adjacent air : this 
 results in an obliteration of the stream-lines near the boundary. The effect 
 
86 
 
 HYGIENE 
 
 is considerably increased by the friction between the moving air and the 
 neighbouring air, which gives rise to a series of eddies, so that the motion of 
 the air often camiot be traced as a continuous stream for any great distance 
 from the inlet. Stream-lines are still further obliterated by the cross currents, 
 due to local causes, such as the convection produced by sources of heat in 
 the room. These, as we have said (§ 14), are often very numerous, and 
 often varyingj and hence we cannot hope to trace the complete path of the 
 entering air. There are, however, some cases in which the conditions are 
 favourable to the permanence of the currents, over a comparatively long 
 path, and steady motion, with stream-lines of permanent shape, establishes 
 itself in certain parts of the room. For such cases, if the air of the currents 
 is cold, and passes across the occupants of a room, the effect is well knoA\ai 
 as a draught. A good, steady draught is a sufficient indication of steady 
 stream-lines of cold air in tlie region. 
 
 30. Well-established stream-lines of hot air are also frequently formed in 
 vertical columns and across ceilings, but as they are generally out of the 
 reach of persons occupying the rooms, or are not so markedly unpleasant as 
 cold currents, they are less generally noticed. 
 
 ^ Fllt pe:r Mrw: 
 "9 
 
 132" 
 
 Pig. 22, 
 
 _M3 TE'ET PER MMUTt 
 
 fEET 
 
 Fig. 23 
 
 Stream-lines can, moreover, generally be traced in the immediate neigh- 
 bourhood of inlets and outlets. In speaking of air-ducts we have given the 
 name of rapids to that part of the jet, either issuing or emergent, where the 
 motion is very considerable. We can, therefore, trace the stream-lines for 
 the rapids, and the main use of this tracing will be to indicate the limits of 
 the rapids. 
 
 In order that the reader may form for himself an accurate idea of the 
 extent of the rapids formed by a current of air issuing mto a room as it 
 spreads out from the orifice under the influence merely of its own motion, 
 we have made two diagrams drawn to scale (figs. 22, 23), from measurements 
 upon actual currents generated by a ' Cyclops ' rotary fan in a large room, 
 showing the boundary line on each side of a horizontal section of the current 
 and the velocity of air at the core. The currents were delivered through a 
 short straight cardboard tube about fourteen niches long. It will be noticed 
 that the current with the higher velocity has a wider angle of spread at the 
 nozzle, and the velocity m the core falls off more rapidly in the stronger than 
 with the slower running current. The general shape of the stream-lmes in 
 
WARMING AND VENTILATION 
 
 87 
 
 the rapids can easily be inferred from the direction of motion at the orifice 
 and the extent of the rapids. 
 
 The energy of the motion of the issuing air is more dissipated in eddies 
 
 SCALE /9 
 
 Fig. 24. 
 
 if the velocity of entry be greater, as the diagrams indicate, thus a rapid 
 current of air will cause more complete mixing with the air in the room than 
 the slow delivery of the same quantity of air through a larger opening ; but, 
 
 Fig. 25. 
 
 on the other hand, the greater velocity means a much more definite current 
 for a short distance, and hence may cause unendurable draughts, whereas 
 the slow delivery may cause more widely extended draughts, which though 
 unpleasant are not classed as unendurable. 
 
 We have reproduced, also, three diagrams of inlets (figs. 24, 25, and 26), 
 
88 
 
 HYGIENE 
 
 and one of an outlet (fig. 27), by General Morin (Etudes, ii. pp. 184-188), 
 representing, in vertical section, the extent of the rapids for two orifices of 
 entry, and one orifice of exit respectively. In figs. 21 and 27 the orifice 
 represented is the same, a rectangular opening eleven feet by three inches. 
 The velocity of entry in fig. 24 is about six feet per second, and in fig. 27 
 the velocity of exit about 7*5 feet per second. The observed dimensions of 
 the stream are figured on the dra\Yings in millimetres. The dotted line of 
 boundary of fig. 24 shows the observed extent of the vertical section of the 
 entering stream, within which the velocity is sufficiently great to affect an 
 air-meter, that is, not less than 5'5 inches per second. The full line indicates 
 the same boundary with the irregularities of observation smoothed out. The 
 
 SC/lLt 1^s 
 Fig. 26. 
 
 SCALE /9 
 Fig. 27. 
 
 boundary Hne in fig. 27 similarly indicates the limit beyond which the air- 
 meter ceases to show a current. 
 
 Figs. 25 and 26 represent vertical sections of streams of air issuing from 
 a rectangular opening four feet wide by three inches high. The boundaries 
 of the stream were determined by the use of a candle flame. Fig. 25 repre- 
 sents two streams, the wider issuing at the rate of 3'3 feet per second, the 
 narrower at two feet per second. The dimensions of the former are figured 
 on the drawing in millimetres. Fig. 26 represents the vertical section of a 
 stream issuing from the same orifice as the preceding at the rate of 2*4 feet 
 per second. The issuing air in all these cases was cold. Compared with 
 the streams represented in figs. 22 and 23, the widening out at a short dis- 
 
WABMING AND VENTILATION 
 
 89 
 
 tanee from the orifice is very marked, and is to be attributed to the orifice 
 being long and narrow instead of being cyhndrical. 
 
 31. We shall attempt to give in figs. 28, 29, and 30 some actual examples 
 of stream-lines drawn, or rather inferred, from observations of the vertical 
 motion of air, so as to give the reader a general idea of what the motion of 
 air would be in any special case of ventilation that he may have to deal 
 with. In general character, the problem is the same as the determination 
 of the flow of water in corresponding cases ; and the reader may, perhaps, 
 be helped to reahse the actual state of the motion of the air in any special 
 case if he will consider what the distribution of currents would be if water 
 were the fluid he were dealing with instead of air. The permanence of slow 
 currents of water through water can be shown experimentally if the flowing 
 water be slightly coloured, and there is little doubt that analogous cases of 
 the flow of air through air could be exhibited if the flowing air could be as 
 easily identified as coloured water. An obstacle in the way of a current of 
 air promotes the formation of eddies and consequent mixing, especially if 
 the flow is rapid ; if the flow is slow, however, a steady current may establish 
 itself round the obstacle. 
 
 In order that the effects of the flow may be freed from disturbance on 
 account of its difi"erent density the entering air must be at the same tem- 
 perature as that into which 
 it flows. This is, however, 
 seldom practicable, and we 
 must deal with cases of 
 flow into relatively warmer 
 or colder air. In such 
 cases a horizontal current 
 will be deflected down- 
 wards or upwards, as the 
 case may be. A current 
 of warm air directed ver- 
 tically upward will extend 
 further, and a correspond- 
 ing current of cold air will 
 be less extensive, and, vice 
 versa, when the direction 
 of the current is vertically 
 downward. An orifice for 
 the admission of cold air 
 in the ceiling of a room 
 shghtly warmer than the 
 entering air affords a very good instance of permanent stream-hnes continuing 
 to the table or floor underneath the opening. In a large hall or church, a 
 lantern tower with large area of windows may produce near the floor below 
 it, on a cold day, a descending current which very clearly exemplifies the 
 steadiness of flow for a considerable vertical distance ; the effect produced on 
 those sitting below is that of a cold down-draught, not attributable to open 
 windows, but to the cooling effect of the windows on the air of the tower. 
 A similar effect may frequently be observed at the sides of churches with 
 clerestory windows. A row of hot-water pipes along the central passage of 
 the church produces an oppositely directed current of warm air ; the circu- 
 lation is completed by a cold air current along the floor and an opposite 
 current along the ceiling. The course of the currents is represented by arrows 
 in fig. 28. The result of such an arrangement will therefore be that a larse 
 
 Fig. 28. 
 
90 
 
 HYGIENE 
 
 pai-t of the beat of the pipes will pass through the glass of the windows with- 
 out producing any effect in raising the general temperature of the building. 
 
 In the case figured the currents are not due to the introduction of fresh 
 air from outside, but to the circulation established in the interior of the 
 building. In introducing fresh cold air it is extremely difficult, if not 
 impossible, to prevent cold currents in the lower parts of the building. 
 With the object of avoiding such currents the incoming fresh air is directed 
 upwards either by a Tobin tube (see fig. 29) or a JSherringham inlet, or, more 
 simply, by leaving an open space between the upper and lower sashes of the 
 windows ; but if these expedients be primarily successful in mixing the 
 incoming fresh air with some of the warmer air of the room we still get a 
 
 64° 
 
 
 f ^ 
 
 
 
 
 /'r ^' 
 
 
 
 t 
 
 
 
 / <r^ 
 
 
 
 ,' r 
 
 - t 
 
 
 
 
 
 
 \ 54° 
 
 
 
 
 >.^ 
 
 
 \\ 
 
 o 
 
 36-5 
 
 \ ^^.^ 
 
 
 
 A 
 
 — j 55° '^ 
 
 
 ; \ 
 
 s 
 
 
 
 
 
 
 
 ' I 
 
 
 
 S-- 
 
 
 
 /? 
 
 59° 
 
 SCALE XoTLtolfaot 
 
 Fig. 29. 
 
 SCALL %C7lM)1pOt' 
 Fig. 30. 
 
 reservoir of air near the ceiling (round the opening) considerably colder than 
 the air of the rest of the room, and the next stage of the problem may be 
 stated thus : Certain outlets have to be supplied and the air has to be moved 
 from the cold regions (near the inlets) to the outlets ; what will be the dis- 
 tribution on the floor ? The best answer that can be given is that the 
 colder air will make a very short journey to the floor, and will then move 
 along the floor towards the outlets if they are near the floor ; if, however, 
 they are near the ceiling, a layer of cold air will lie on the floor until part 
 of it is warmed sufficiently to rise to the outlets. 
 
 Warm air delivered into a room will behave in just the opposite way : 
 if it is directed upwards it will make its way direct to the ceiling ; if directed 
 
WABMING AND VENTILATION 91 
 
 downwards, the flow in that direction will soon be stopped, and a reservoir 
 of air formed, warmer than the rest, and from this warm reservoir air will 
 rise to the ceiling and there form a warm layer. 
 
 In order to illustrate the motion of the air in these two typical cases 
 I have investigated experimentally, by apparatus described in a subsequent 
 chapter, the flow of air from two Tobin tubes, one delivering cold air and the 
 other warm air, and plotted the distribution of flow for the two cases in 
 figs. 29 and 30. The figures are, of course, only rough approximations, but 
 they are drawn to scale so as to give an idea as to how far the motion 
 extends in the two cases. The boundary of the stream of air is represented 
 by a dotted line, and the direction of flow by arrows ; the velocity in the 
 tube is indicated, as well as the temperatures in the tube, the stream, and 
 the air of the room. 
 
 APPLICATION OP THE FOREGOING PEINCIPLES TO SPECIAL CASES 
 
 32. In discussing the principles of ventilation we have analysed the process 
 into ' General Circiilation ' (§§ 15-28), and ' Local Circulation ' (§§ 29-31), 
 and have considered separately the effect of different characteristic conditions. 
 The application of the principles will be made clearer if we take some 
 specific instances. We will arrange them in order of simplicity. 
 
 1. Closed Room with Heating Apparatus 
 
 33. Let us first suppose that we have a room which, during its occupation, 
 has no opening except unintentional crevices, and which is warmed by a gas 
 stove without chimney, or by hot- water pipes along the floor on one side. 
 It is provided with windows which we suppose to be shut. From the point 
 of view of ventilation such a room, of course, borders on the impossible, but 
 there can be few people who have not had to spend some hours, at any rate, 
 in rooms of which the above is a fairly accurate description. 
 
 Here we have to deal with local circulation only. General circulation does 
 not exist to any large extent ; enough fresh air comes in at some of the 
 crevices, supplying the place of air that leaves by the others, to keep a gas 
 fire burning continuously. If it is cold the fresh air forms a layer on the 
 floor and devotes itself almost exclusively to the combustion of the gas. 
 The local circulation is fairly simple ; the stove or hot-water pipes cause an 
 upward current, the window a downward current, and so there exists a 
 fairly active circulation between the stove, or water-pipes, and the windows. 
 The persons in the room also cause upward currents, so that the air is kept 
 fairly well mixed. Here our description of the circulation ceases ; the 
 length of time that such a room is endurable depends first upon its size and 
 secondly upon the powers of endurance of the individuals. The gas stove is 
 an aggravation of the defect ; the hot-water pipes, especially in a large hall, 
 help to keep the room habitable somewhat longer than if they were not 
 present by promoting the local circulation. 
 
 2. EooM WITH Single Opening 
 
 34. The unsatisfactory character of the air of the preceding example leads 
 us naturally to the second, which we may represent by a room with an open 
 window. It will materially aid the correct appreciation of this case if we 
 consider the liquid analogue of it. Imagine a glass box filled with oil and 
 
92 
 
 HYGIENE 
 
 immersed in a large tank of water, and imagine further an opening to be 
 made in the side of the box of oil. The oil being lighter than the surrounding 
 water, the water would flow in at the lower part of the opening and drive 
 the oil out at the upper part of it ; after passing into the box the water 
 would settle down to the bottom and form a layer there. The replacement 
 of oil by water would go on until the part of the box below the level of the 
 top of the opening was filled with water ; then the circulation would cease. 
 
 The oil cannot mix with water, so that the analogy is not quite strict. A 
 more accurate representation would be secured by using water in a solution 
 of salt, but in this case, as in the case of hot and cold air, the mixing which 
 takes place between the inflowing air and the surrounding air is not suf- 
 ficiently extensive to destroy the analogy. 
 
 In a room with a single vertical aperture on one side we have, there- 
 fore, a ' general circulation,' air entering by the lower part of the aperture 
 and issuing by the upper part. The ' local circulation ' depends very largely 
 
 li 
 
 t 
 
 Fig. 31. 
 
 upon the position of the water pipes, but if they are at some considerable 
 distance from the positions vertically under the opening, a cold shower of 
 air and a cold current along the floor are inevitable, together with a warm 
 ascending current from the hot pipes, ultimately reaching to the opening. 
 The action of the wind in this case affects the velocity of ingress, and 
 therefore the position at which the cold air shower is most keenly felt. The 
 common outcry in such a case for having the windows opened ' on the other 
 side of the room ' is merely emlence of the intensity of the cold shower, 
 which is really unavoidable by any such expedient. If the hot pipes are 
 immediately under the windows the state of affairs may be improved by the 
 mixing of currents ; but cold air is very persistent in finding the floor level. 
 
 The calculation of the effect of a single opening, as that described, can be 
 arrived at by considering the course of the air from its entry to its exit, and 
 regarding the part in motion as separated from that, comparatively speaking, 
 at rest by imaginary partitions. 
 
 We may roughly indicate the boundary of the flow by the dotted line in 
 fig. 31, A B being the orifice, and S the point of division into inlet and outlet. 
 If the line X Y be a line dividing the upcast part from the downcast, X Y may 
 be treated as the section of a chimney flue for which S B is the inlet orifice, 
 and A S the outlet orifice ; the head will be due to the difference of density of 
 
or 
 
 WABMING AND VENTILATION 93 
 
 the air in the portion S B to X Y, and the portion X Y to A S respectively ; if 
 we can assume the air of these two portions to have mean temperature t and 
 
 T respectively, the head lb (p. 82) will be roughly — - (T — t) H, where H 
 
 is the height of the window opening above the floor. The resistance to the 
 
 flow will arise from the window-opening merely ; at other parts of the flow the 
 
 resistance will be very small. Suppose A to be the area of the opening and 
 
 A 
 that the inflow area and outflow areas are equal, each being equal to — . 
 
 Then taking these areas as being thin plate orifices the resistance of each will 
 
 ^e E = 27AV4=-7A2 approximately. 
 
 The total resistance will therefore be -— p^, 
 
 7A^ 
 
 and the flow will be 
 
 /lb = / (T-^) h^Tta ^ 
 V E V 500 * 2 
 
 =A^ / (-*- ~t)ii- cubic feet per second, 
 V 140 
 
 / (i t) ti QTj^\yiQ fggi; pgj, square foot of opening. 
 
 Example. — The temperature of a roomis 70° F., the external temperature 
 20° F. ; a window 14 feet above the floor is opened so as to give an aperture 
 Sft. 6 in. wide x 2ft. high : find the amount of air that will flow in per second. 
 
 We shall here assume the temperature of the upcast to be 70° and that 
 of the downcast 20°. Such a distribution is only a rough approximation to 
 the actual state of things after the window has been opened some time. 
 
 By the above calculation the flow is 
 
 7 X A / ^ = 15'6 cubic feet per second. 
 V 140 
 
 The velocity at entry will be about five feet per second, and elsewhere it 
 will be inversely proportional to the section of the moving stream. 
 
 35. When the aperture is in the ceiling instead of the side the problem is 
 very similar, but there being no top or bottom division of such an aperture, 
 an interesting modification is produced that may also be illustrated by the 
 liquid analogue. A heavy fluid on the top of a light one, as when a bottle 
 of water without a cork is immersed in a larger vessel of salt solution, or, to 
 take a commoner example, when a bottle of water is inverted, and the cork 
 withdrawn, is really in unstable equilibrium ; and, as a rule, the fluids of 
 different densities begin to change places. But the character of the motion 
 is different according to the size of the orifice ; if this be large the hghter 
 fluid runs up one side, and the heavier down the other ; if it is very small 
 indeed no flow takes place at all ; for apertures of intermediate size we get 
 the intermittent flow that is a familiar phenomenon observed whenever a 
 bottle of water with a narrow neck is inverted. This interesting case 
 arises because the two fluids cannot divide the channel between them. 
 Similar phenomena are exhibited with air. If a candle is burned in a bell- 
 jar, the only aperture of which is a long narrow tube, the air which comes 
 out in consequence of the expansion by heat prevents the outside air from 
 entering, although it is heavier than the internal air beneath it, and the 
 candle ultimately becomes extinguished for want of oxygen. If, however, 
 the aperture is sufficiently wide a circulation results, and between these 
 
94 HYGIENE 
 
 limits we have the intermittent draught and back draught that a wide 
 chimney exhibits when there is not a sufficient supply of air inlets in the 
 room. If, however, the aperture be divided into two parallel parts by a 
 vertical partition, when once the cold air has gone down one side and the 
 warm air up the other the flow is stable and continuous.^ 
 
 The local circulation for a double aperture in the ceiling acting as inlet 
 and outlet is not sufficiently dissimilar from that of an aperture in the side 
 for us to devote more space to it. 
 
 The efl'ect of such an arrangement can be calculated in a manner very 
 similar to the case of the aperture in the side. Taldng the mean tempera- 
 ture of the whole height H of the downcast (which must be measured from 
 the outside of the ventilator to the floor of the room) as being t, and the 
 mean temperature of the whole upcast as T, we have the head 
 
 The resistance R would be due solely to the channel through the ceiling, 
 and can be calculated by the rules of § 20 ; from these two the flow can be 
 
 determined. 
 
 Example. — A room, the temperature of the air of which is 70° F., is 
 jjrovicled with a vertical ventilating shaft from the ceiling to the external air. 
 The length of the shaft is 5 feet, and it is divided by a partition into tioo 
 parallel tubes, the area of each of which is 1 foot x finches ; find the floio 
 through the shafts if the external temperature be 20° F. The height of the 
 room is 15 feet. 
 
 Taldng the temperature of the whole downcast at 20° F. , and of the whole 
 upcast at 70° F., the height from floor to top of ventilator being 20 feet, we 
 have, as m the previous example, the head 
 
 113= J- X 50 X 20 = 2 feet of air. 
 '•^ 500 
 
 In order to calculate the resistance, we may consider each comparatively 
 short wide tube as a cylindrical mouthpiece, which has a coefficient of con- 
 traction -8. The resistance of each will therefore be (§ 20 {a) and {h)) : 
 
 B 
 
 = JL X . /^ , ^ = -0431. 
 64-4 -64 X 9 
 
 The resistance of the whole circulation will therefore be -086 ; from which 
 
 we eet the flow = . /_^, or about 5 cubic feet per second. The velocity 
 
 ^ V -086 
 
 of influx is about 6 feet per second. 
 
 3. Room with two Sepakatb Openings 
 
 36. The next stage in the development of a complete ventilation system 
 is a room with two separate openings, one of which acts as an exit flue and 
 the other as an inlet. This is the typical case referred to above (p. 62), and 
 we need not consider further the general theory of the circulation. It is, 
 
 1 This principle is exemplified in Watson's ventilator and Muir's ventilator. 
 
WABMING AND VENTILATION 95 
 
 however, a case of such very frequent occurrence, every room witli an open 
 iire and no special mlet being substantially an example of it, that we are 
 led by its importance to consider some of the details. Let us consider first 
 of all the case of a room with an open fireplace, and an inlet whose equivalent 
 orifice is i ; let the equivalent orifice of the chimney be o ; then if lb be the 
 head in feet of air, we have the flow 
 
 "^ — /^j '^-r— = / z. -^~ cubic feet per second. 
 
 Let us first examine the effect upon the flow of a change of size of the 
 inlet orifice. It is evident that the maximum value of the flow whicli is 
 attained when i is extremely large, as, for instance, when the room v/indows 
 are wide open, is ^^ 27 If) o^, and if the inlet be narrowed the flow will be 
 gradually decreased until it ceases altogether, when there is no inlet orifice, i.e. 
 when i is zero. Now we have already seen that a single flue may act as inlet 
 and outlet simultaneously, the cold air coming down one side and the hot 
 going up the other. Hence as the inlet orifice is gradually narrowed we 
 approach this condition. If the inlet orifice be not actually zero, but only 
 very small, there may still be a tendency for this double action of the flue to 
 establish itself, in which case the chimney will ' smoke,' a phenomenon 
 sometimes experienced with chimneys with straight flues, when the access of 
 air to the room is not sufficient. Let us extend the reasoning further, and 
 inquire into the conditions under which this kind of ' smoking ' is likely to 
 take place. We suppose a small inlet, say the crevices of doors and windows, 
 with an equivalent orifice i ; then there are two alternatives which the air may 
 choose in order to replace the lighter warm air by the heavier cold air : (1) the 
 chimney behaves as an outlet only, the whole air supply coming through 
 the crevices ; the flow in this case is 
 
 ^27 lb. 
 
 (2) the chimney acts as both inlet and outlet, air coming also through the 
 chinks. In the second case, if Ave suppose half the shaft to be occupied with 
 cold air coming down and the other half with warm air, the air coming down 
 the shaft may be regarded as traversing a tube of half the area of the 
 chimney : the equivalent orifice of entry for this duct will be o/2, and, by 
 
 law 4 (p. 64), the whole orifice of inflow will be i + ^, and the inlet resist- 
 ance 1 
 
 (^+1)- 
 
 27 
 
 the outlet resistance, that of the other half of the shaft, 
 
 the total resistance will therefore be 
 
 1 1 
 
 + 
 
 27fi+|y 27 Q) 
 
06 HYGIENE 
 
 The head may be assumed to be the same in both cases, and hence the flow 
 on the second alternative will be 
 
 Xow we have to decide which of these two alternatives the air will choose. 
 "We may assume that that alternative will be chosen which offers the least 
 resistance, and this will be the second one if 
 
 1 ._J_ 1 1 
 
 ''' ' — 2 is less than _ -|- - . 
 
 (^-ir G) 
 
 I' 0' 
 
 It can be shown that the condition is that i should be less than o/2. 
 Hence we find that the chimney will ' smoke ' if the total area of the inlet 
 orifice is less than half the equivalent orifice of the chimney. This result 
 is of considerable interest, but it cannot be pressed with great numerical 
 accuracy on account of the numerous assumptions made in the course of the 
 reasoning ; but it is sufficient to show in a striking manner the importance 
 of providing sufficient inlet area. Further, it may explain a well-known 
 empuical principle advocated by some architects, namely, that to prevent 
 smoking, a chimney should not be straight but bent. It is easy to see that 
 at the bends the up and down currents would mix, and the division of the 
 shaft between the two could hardly under any circumstances be established, 
 and, therefore, this particular cause of smoking could not be active in a 
 chimney with a bent shaft. 
 
 In the equations we have used hitherto we have neglected the change in 
 the density of air when it is heated ; we have, in fact, assumed the flow in 
 cubic feet per second to be the same at the inlet and the outlet. If, however, 
 the difference of density is too great to be neglected, we may correct the 
 equations as follows. Dividing the total head into partial heads h^ and /i^ , we 
 have for the flow V through the outlet in cubic feet per second 
 
 h 
 1 
 
 27o2 
 
 and for the flow through the inlet, V^ = .2, ^ 
 
 27T2 
 
 But if A is the density of the cold air, and A' that of the warm air, V^A^ 
 
 __ Y'2_\/2^ 
 
 " «J M 27i2 27o2 A'2 
 
 =Y^\Jl. 4. 1_ {l + a(T-32)]2 
 1 27^2 "^ 27o2 {1 + a(iJ- 32)2) 
 
 where T is the temperature of the air in the shaft, t the external temperature, 
 and a the coefficient of expansion of air, i.e. 1/491. 
 
 Hence 1b -^M ^ + U + « (T - 32))2 ) 
 
 Hence 113 - ^^ 1^^+ ^^ (1 + a(«- 32)}2r 
 
WABMING AND VENTILATION 97 
 
 and 1I3 = ^^J_- (T-OH . . . (§28.) 
 
 This somewhat complicated calculation can easily be pursued, by those 
 who have some acquantaince with mathematical methods, to show that the 
 flow does not increase indefinitely with the temperature T of the air in the 
 flue. It reaches a maximum at a temperature which is given by the equation 
 
 T -t= (459 + Oa/i+- 
 
 So that if the inlet orifice is very great compared with the outlet, the 
 maximum is reached at a temperature 523 + 2, {t - 32) ; otherwise the 
 temperature of maximum flow will be much higher ; indeed, practically, 
 the inlet orifice is very small, the flow increases with the temperature up to 
 the limits of temperature ordinarily attainable. 
 
 37. Two special points about the construction of chimneys require our at- 
 tention. First it is usual, in register grates especially, to make the communi- 
 cation between the fire-place and the chimney somewhat smaller in area than 
 the chimney shaft ; this narrowed area is called the throat of the chimney. 
 It affects the resistance by requiring the velocity of the air to be increased in 
 order to get the same flow through the narrower passage, and is therefore an 
 artificial contraction of the orifice, and its effect may be represented by a 
 suitable coefficient of contraction. If, as is generally the case, the sides of 
 the throat are coved, then, roughly speaking, no coefficient of hydrodynamical 
 contraction will be required for the throat itself, regarded as an aperture, so 
 that the effect of the throat becomes the same as if it were an orifice with a 
 coefficient of contraction equal to the ratio of the measured area of the throat 
 to the measured area of the shaft. Let f be this ratio, then the resistance due 
 to the throat is 
 
 t-4 \f J A2' 
 
 64 
 
 where A is the area of the shaft. 
 
 Secondly, it is usual to provide the orifice of a chimney flue with a chimney- 
 pot. The result is, generally speaking, a narrowing of the orifice of discharge, 
 and this is, from the scientific point of view, the object of the addition. While 
 the area of the shaft of the chimney should be decided from the consideration 
 of the greatest possible flow of air, and should therefore be of considerable size, 
 the area of the orifice of discharge is determined with a view of securing a 
 sufficient velocity of discharge to give adequate stability to the draught. 
 General Morin assigns 5 feet per second as the proper velocity in the chimney 
 and 10 feet per second as the most suitable velocity of discharge. The best 
 form of chimney-pot is one in the form of a truncated cone with in-curving 
 sides, for in that case the orifice has no coefficient of hydrodynamical con- 
 traction per se. The effect of such a chimney-pot is to produce an arti- 
 ficial contraction from the area of the shaft to the area of the orifice, and the 
 effect is the same as if a mouthpiece were adjusted which had coefficient of 
 
 contraction -r , where a is the area of the orifice and A that of the shaft ; the 
 
 A. 
 
 resistance added by such an addition to the shaft is therefore 
 
 W AV 
 
 VOL. I. 
 
98 HYGIENE 
 
 Adopting General Morin's figures for the velocities, a would be one-half of A 
 
 3 1 
 
 and the resistance of a chimuej^-pot would be — — - x -^„, where A is the area 
 
 •' ^ G4-4 A- 
 
 of the shaft. 
 
 Example. — Find theflotu of air through a room with an open fire, and find 
 
 tlie amount of coal that must he biiriied to maintain it, having given thefolloiv- 
 
 ing particulars. Outlet : — A chimney of circular section 9 inches in diameter 
 
 with two bends of 45° each, the first at a height of 10 feet from the floor, the 
 
 second at a height of 11 feet, the remaining vertical portion of the flue being 
 
 ^5 feet. The chimney is provided with a trumpet-shaped cap with the orifice 
 
 G inches in diameter. The throat of the chimney is a semicircular area, 9 inches 
 
 in diameter, '2. feet from the ground. Inlet: — A Tobin tithe Qx9 inches, the 
 
 inside vertical length being 5 feet, and the loioer part horizontal and 2 feet 
 
 long, covered by a grating of tvhich half the area is occiipied by the bars. 
 
 Temperature of air in the flue 182° F. Temperature of external air 32° F. 
 
 Head. — If we neglect the small loss of head due to the fact of the cold 
 
 air having to be forced up the 5 feet of Tobin tube (which -will depend on the 
 
 difference of temperatm-e of the external air and the air of the room) the head 
 
 lb will be==^ X 40 feet of air, since the total vertical height above the throat 
 491 
 
 is 40 feet. 
 
 The resistance of the outlet will be made up as follows : — 
 
 Resistance due to the throat (assuming that the sides leading to it are coved 
 
 BO as to give a coefficient of contraction equal to unity), 
 
 ''■''mi 
 
 = -3G0. 
 
 Resistance due to friction (hydrauhc mean radius '19 foot), 
 
 '01x43 1^ 
 
 •19 X 32-2 • f /4-5N 
 
 Resistance due to bends. 
 
 64-4 2 ' /4-5\2 ] 2 
 
 Resistance due to cap, 
 
 1 / 1 
 
 64-4 
 
 '0'}^ {<'m 
 
 = -323. 
 
 Coefficient of head spent in producing velocity, 
 
 1 X , }. . .. . =-. -403. 
 g4. ■ 
 
 " {m 
 
 Total resistance of outlet, Ri = 1-405. 
 
 Besistance of inlet : — 
 
 Resistance of grating (coefficient of contraction "GS), 
 
 M(-A4r'(b'^' 
 
 3\^^=-07O. 
 
WABMING AND VENTILATION 99 
 
 Eesistance due to friction (hydraulic mean radius 0"15 ft.), 
 •01x7 ,. 1 
 
 •15x32-2 
 
 (14) 
 
 •103. 
 
 Eesistance due to one rectangular bend, 
 
 g^x7r^.=-"0- 
 
 Total resistance of inlet, E2 =^283 
 
 Flo"W= A / . ^ ^ =2-69 cubic feet per second. 
 V E1+E2 
 
 The amount of coal required to be burned for this circulation can be 
 determined from the flow, with the knowledge of the amount of heat 
 developed by the combustion of 1 lb. of coal (p. 122), the density and specific 
 heat of air, and the given rise of temperature. 
 
 38. It remains for us to consider the local circulation in such a room as 
 here discussed. If the inlets all supply cold air the distribution of the air on 
 entering may be inferred from fig. 29 (p. 90) . It results in the formation of a layer 
 of cold air on the floor, moving with appreciable velocity towards the fireplace 
 and causing a cold draught to the feet. This will be the case in a large room, 
 even if the air is directed into the room, by Tobin tubes or otherwise, with a 
 vertical motion ; in a small room the greater part may be occupied by the 
 descending shower indicated in fig. 29, and the cold layer may not have space 
 to form. This effect might be modified to a certain extent by having a large 
 number of narrow Tobin tubes made of metal, instead of a single one made 
 of wood, as the air would in the former case issue from the tubes more 
 nearly at the temperature of the room, whereas with a good thick wooden 
 case the air is kept as nearly as may be at the external temperature until it 
 is actually in the room. 
 
 There will be rapids at each inlet orifice and in the immediate neighbourhood 
 of the grate, but their effect is not very conspicuous unless the air is very cold. 
 The general type of local circulation for a room with an open fire and 
 cold air inlets will therefore be rapids at entry and exit and a cold layer from 
 one to two feet thick on the floor moving towards the fire. It is, however,, 
 interfered with by local causes, the most important of which are the surfaces 
 considerably heated by direct radiation from the fire.^ In particular, the floor 
 immediately in front of the fire gets warmed in this way and helps to warm 
 the air passing over it, and if the radiation is sufficiently intense and the flow 
 restricted, a column of ascending air is formed in front of the grate and the 
 fire is fed by the cold air from the sides coming round the rising column. A 
 fender which screens the hearth-rug from the direct radiation of the fire keeps 
 the rising column within its own area, where it may often be easily detected. 
 If the entering air is warmed to a temperature the same as that of the 
 room it wiU mix more completely with the air of the room, and the formation 
 of a current along the floor will be avoided. If its temperature exceeds that 
 of the air of the room, a layer of warm air will be formed at the ceihng, and 
 will of course ultimately fill the room unless it escapes by ventilators in the 
 ceiling. It becomes mixed with the respired air rising from the occupants of 
 the room, so that adequate ventilation with warmed air requires the full 
 supply specified in section 52). 
 
 39. An interesting case of local circulation occurs when a room with an open 
 
 ' See the distribution of the temperature in the figure, p. 110. 
 
100 
 
 HYGIENE 
 
 fire and cold air inlets, or no special inlets, is also lighted by a number of gas 
 jets on the same level. As shown later, p. 115, the intense heat of the bm-ning 
 gas causes a local circulation which does not practically extend below the 
 plane of the burners ; we then get the room divided into three almost inde- 
 pendent zones, a torrid zone from the ceiling to somewhat above the level of 
 the gas jets, mainly occupied by very foul air, especially in the upper part ; 
 a frigid zone extending from the floor to about one foot in height occupied 
 by the fresh entering air on its way to the fire : between these two is a 
 temperate zone of air without any special circulation. Diffusion and special 
 local causes produce a certain amount of intermingling of the air of these 
 three zones, and in particular the boundary between the torrid and the tem- 
 perate zones is very ill-defined, the temperature rising gradually towards the 
 
 Fig. 32. 
 
 ceiling where it is very high ; but the separation is fairly complete, and thus 
 the effect of burning a number of gas jets as described is practically to reduce 
 the height of the ceiling of the room. The state of the air in the temperate 
 zone is not generally regarded as unendurable, but the occupants would be 
 much better supplied if they could breathe at a lower level than is usually 
 the practice. An ideal diagram of the stream lines of the local circulation 
 in this case is given in fig. 32. 
 
 A diagram showing a special instance of local circulation in a room with 
 an open fire is given later, p. 110. 
 
 4. KOOM WITH ONE OuTLET AND SEVERAL InLETS 
 
 40. We have already indicated the treatment of this case. If the inlets are 
 direct from the open air, or cold air inlets, they are equivalent to a single 
 inlet with an equivalent orifice equal to the sum of the equivalent orifices of 
 the separate inlets. If they are hot air inlets, there may be some appreciable 
 head due to the inlet itself which must be allowed for. Thus if the outlet 
 head would produce a partial head h^ for one inlet duct, and the duct itself, 
 reckoned separately, produces a head H' the actual effective head for that 
 duct would be h^ + H', and the flow must be calculated accordingly. 
 
 5. EooM WITH TWO Outlets and one Inlet 
 
 41. This is a case of very frequent occurrence, being realised whenever a 
 separate ventilator is provided with special flue to take away heated air in a 
 
WABMING AND VENTILATION 101 
 
 room which has an open fire. One of the most frequent plienomena exhibited is 
 that the ventilating shaft acts as an inlet and lets in cold air instead of removing 
 warm air. The reason for this back draught we shall endeavour to explain. 
 Suppose 1b the total head due to the chimney ; it may be divided into two 
 partial heads, h^ for the chimney regarded as a duct, and h.2 for the flow 
 through the inlet. Let Ej be the resistance of the chimney, R2 that of the 
 inlet duct. Let H' be the separate head for the ventilating flue, depending 
 on the difference between the temperature of the air in it (and in the room) 
 and that of the outside air ; then the effective head for that shaft is II' — h.^, 
 since the flow for the two heads separately would be in opposite directions. 
 Thence if H' = /ij, the head becomes zero, and the flow through the venti- 
 lator ceases, and at that instant the ventilator does not affect the circula- 
 tion through the room which would be produced by the chimney alone. 
 We can therefore calculate hc^ as though the ventilator were closed. But 
 since h2 = R2 V^, and hy = ElV^ and 1b — ^^-i + /i2» 
 
 we have =--rr — "^^ft. 
 
 ID El + Ea' 
 
 And the condition for cessation of flow is, therefore, 
 
 W ^ Bj, H' ^ E., 
 
 lb El +E2' "" tf-H' e; 
 
 Now the head H' =-— 7^ (T' — t) W, where T' is the temperature of 
 
 459 + t 
 
 the air in the ventilating flue and H' its height from the room floor to the 
 external orifice, and a similar relation holds for the head for the chimney, 
 so we get the following result : — The ventilator ceases to draw air from the 
 room as soon as the inlet orifice is so narrowed that the ratio of the resist- 
 ance of the inlet to that of the chimney-flue is equal to, or greater than^ 
 •the ratio of (T' - t) W to {T - t) H - (T' - t) H'. Supposing that the 
 chimney and ventilating flues are of equal height, the ratio becomes 
 T' — ^ : T — T'. That is, for the ventilator to act, the excess of temperature 
 of the air in the flue, above that of the outside air, must bear a greater ratio 
 to the excess of temperature in the chimney over that of the air in the flue 
 than the ratio of the resistance of the inlet to that of the chimney. If 
 « and a' be the equivalent orifices of the chimney and inlet respectively 
 
 _i = " 
 
 E2 a 
 
 whence we get : — the condition for action of the ventilator is a^a must be 
 greater than ^ / ± ±_. 
 
 Thus it appears that with a given chimney the action of the ventilator 
 depends upon the area of the orifice of inlet, and if we take as an instance a 
 chimney whose equivalent orifice is 30 square inches with the temperature 
 of the air in its flue 250° F, and that of the air in the room and ventilating 
 flue 70° F., the outside air being at 50° F. the ventilator will cease to act 
 
 if the inlet orifice is less than a / ~ x 30 square inches, i.e. 90 
 
 V <U — 50 
 
 square inches. 
 
 This area of inlet is seldom realised in practice, and therefore it is not 
 surprising that under ordinary circumstances a ventilator nearly always 
 declines to act as intended. 
 
 We have found the condition that the head for ventilation in the flue is 
 
102 
 
 HYGIENE 
 
 exactly balanced by the partial bead produced by the chimney ; but such 
 balancing can be only instantaneous, lor the equilibrium is unstable. If the 
 cold outside air penetrates a little way down tlie Hue, the head for outward 
 flow is reduced in consequence, and cannot any longer sustain the pull 
 of the partial head, so the cold air flows further down, and the head is 
 thereby still further diminished, and so the ventilator immediately acts as 
 an inlet instead of a balanced outlet, and here an interesting point becomes 
 clear. In order to resuscitate the outflow when the inlet is enlarged to a 
 sufidcient size to maintain it, if it were once established, we require a head in 
 the flue ; but this cannot arise until the flue is filled with warm air, and 
 this will not naturally occur, as it now acts as an inlet. It may occur 
 fortuitously by the action of a gust of wind across the top of the flue ; other- 
 wise it can only be restarted by increasing the inlet to such a size that the 
 partial head produced by the chimney is so reduced that the head due to the 
 warm air in the room is sufflcient to overcome the flow down the ventilator 
 and start a fresh flow upward. 
 
 G. KooM WITH TWO Inlets and two Outlets 
 
 42. We shall consider only the special case, when the two o^itlets have 
 equal heads, and we shall investigate the conditions under which the flow 
 through one inlet shall be adequate to supply the one outlet, while the 
 second outlet is fed entirely by the second inlet, so that the complex venti- 
 lation system may be divided into two separate simple systems. One of its 
 practical apphcations is as follows. Suppose two adjoining rooms (fig. 33 ) with 
 a door between them have each an open fire, and neither of them is pro- 
 
 IR, 
 
 / 
 
 u 
 
 R' 
 
 Fig. 33. 
 
 vided with any special inlet. Suppose that the height, and the temperature 
 of air in each chimney are the same, will there be any flow of air between the 
 rooms, and if so in which direction ? 
 
 If the rooms communicate by a large opening like that left by an open 
 door, there may be local circulation between the two. This we are not con- 
 sidering, and therefore we shall suppose that the area of communication is 
 
WARMING AND VENTILATION 103 
 
 very small, by means, for instance, of a narrow tube. We may represent 
 the arrangement by fig. 33, in which T represents the tube. If there is no 
 flow through this tube the two systems will be independent, and can be 
 treated as if the tube were actually closed. On this assumption the head 
 1b for the one circulation may be regarded as divided into two partial 
 heads, h^ and h^, for the outflow duct and inflow duct respectively. Let the 
 resistances of these ducts be E, and K2 respectively ; then we have 
 
 h, = EiV2, h, = K2V2 ; 
 
 . K _ B2 
 • * lb E, + Eg* 
 
 If 1b', ^^'^2, E/, Eg' be corresponding quantities for the second circulation, 
 we have in precisely the same way, 
 
 lb' E/ + E/* 
 
 Now 7i2 is the head for inflow or difference of pressure between the one 
 room and the outside air, and h^' is the difference of pressure between the 
 other room and the outside air ; hence if these two are equal the pressure will 
 be the same throughout the two rooms, and no cross flow will take place. The 
 condition of no cross flow is therefore h.2 = h^', and if /z-g be greater than Ag' 
 iihe flow will be in the direction from the second room to the first. Since 
 we supposed the temperature in the two chimneys to be the same we have 
 lb = lb'. Hence the condition is 
 
 Ea _ ^ E./ 
 El + E2 E/ + E2' 
 
 E, E/ 
 
 ■or — -= — -. 
 
 E2 E2' 
 
 In words : — There wiU be no flow between the rooms, or the two circulations 
 will be independent, if the ratios of the resistance of inlet and outlet be the 
 same for the two circulations ; and if the ratio of inlet to outlet be greater 
 for the one circulation than the other, there will be a flow from the circula- 
 tion with the greater ratio to that with the less ratio. 
 
 This condition has been tested experimentally on a smaU scale and found 
 to apply with very great accuracy.^ 
 
 We have assumed the head for each of the two circulations to be the 
 same ; it is evident that a condition can be obtained in like manner if that 
 is not the case ; but it leads to somewhat more complicated expressions. The 
 reasoning shows very clearly the precautions that must be taken to isolate 
 . any circulation without actually completely separating the rooms, or at any 
 rate to secure that, if two circulations interfere, the air shall pass between the 
 two in a given direction. Take, for instance, the following case. One room 
 •of a house is occupied by an infectious fever patient, and it is desirable to 
 •adopt precautions to prevent the air of the patient's room passing into the 
 house. The provisions to be aimed at are first, an outlet duct with a head 
 for ventilation in the room itself; an open fireplace and chimney will, 
 •of course, suffice, and the higher the temperature of the air in the chimney 
 the better ; secondly, the ratio of the equivalent orifice of inlet to that of 
 the chimney must be at any rate not greater than the corresponding ratio 
 for the adjoining spaces ; in the absence of special measurements make the 
 inlet openings in the infected space small, and the inlet openings for the 
 rest of the house as large as possible. 
 
 ' Shaw, Proc. Boy. Soc. March 1800. 
 
Wi HYGIENE 
 
 EXPERIMENTAL INVESTIGATION OF THE ACTION OF A VENTILATION 
 SYSTEM. INSTRUMENTS FOR DETECTING AND MEASURING CURRENTS 
 OF AIR 
 
 43. In considering tlie practical applications of the principles which have 
 been laid down in the preceding pages it will be at once evident that 
 successful veAtilation must satisfy two fundamental conditions. For the 
 sake of clearness we will continue to regard the ventilation system as 
 represented by a single chamber to be supplied with air, and therefore pro- 
 vided with inlets and outlets. The two fundamental conditions are : (1) 
 That sufficient air should be made to flow through the system ; (2) that on 
 passing into the chamber it should be so distributed as to replace foul air 
 and not to cause cold draughts. We wish now to deal with the methods of 
 determining in what way, and to what extent, a particular ventilation system 
 is faulty with respect to these two fundamental conditions. Unsuccessful 
 ventilation is of course generally detected by anyone who has the misfortune 
 to be exposed to it, without any special directions for finding it out. But it 
 is important to be able to decide whether the want of success is due to want 
 of air or misdirection of air, and in the latter case to find out where the air 
 is going to, whether, in fact, the fault lies in the ' general circulation ' or 
 in the ' local circulation.' The two conditions which have been laid down 
 may most conveniently be treated separately. We shall first mention the 
 apparatus by Avhicli an examination of the system should be made. 
 
 Examination of the General Cikculation 
 
 44. The question whether the air-supply is sufficient is capable of being 
 tolerably accurately answered, provided that the outlets or the inlets can all 
 be identified and measured with sufficient accuracy. It must, of course, be 
 remembered that if special inlets are provided the air will not necessarily 
 pass through them exclusively. A difference of head determines a flow of 
 air through every orifice, great or small, whether intended for the admission 
 of air or not. For the same difference of head, the flow is proportional to 
 the area in a thin plane wall which would be equivalent to the orifice. If 
 an alternative opening is provided which is very ample, the head for a 
 casual orifice, or crevice, may be very much reduced, but it will not be 
 absolutely zero, so that there Avill always be some flow through the 
 crevice. We shall suppose, however, that the doors and windows are 
 sufficiently well fitted to prevent any considerable flow through the joints if 
 the room be provided with special inlets. In that case we can measure the 
 circulation by measuring the area of each inlet and the mean velocity of the 
 air passing through it. The area of the shaft can be calculated from a 
 scale plan of its section. If the opening is covered by a grating it is better 
 to adapt a continuation of the shaft in zinc or cardboard. The velocity may 
 be measured by an anemometer, or air-meter ; the pattern most frequently 
 used is a light wheel with inclined vanes and furnished with counting gear 
 and dials. The instrument is represented in fig. 34, and is made by Casella 
 and other instrument-makers. The instrument records directly the velocity 
 of the air in feet per minute by an observation of the graduations jDassed over 
 by the needle in the same period, but a correction must be added to each 
 observation representing the minimum velocity which will move the vanes. 
 The correction amounts to about 30 feet per minute, or G inches a second;. 
 
WABMING AND VENTILATION 
 
 10.': 
 
 it is determined by the instrument-maker before the instrument is sent out. 
 It could be verified by carrying the instrument along for a known distance 
 in still atmosphere or by mounting the instrument at the end of a long arm 
 attached to a revolving table, measuring the circumference of the circle so 
 described, and comparing it with the result given by the anemometer after 
 a complete revolution. 
 
 In order to determine the mean velocity for the inlet, care must be taken 
 to observe the velocity at a number of different points — some near the edge 
 others near the middle — and take the mean of the measurements, or to keep 
 the anemometer moving slowly across the aperture during an observation. 
 
 Having determined the mean velocity and the area, the product gives the 
 circulation in cubic feet per minute. The weight delivered per second can 
 easily be calculated if required. "When the delivery for each inlet has been 
 measured the total delivery for the whole circulation is obtained by adding. 
 
 If there are no special inlets the determination of the circulation must 
 be obtained from measurements of the flow through the outlets, provided 
 these are sufficiently definite. In order to determine the flow of air up a 
 chimney the front of the fireplace should be covered Avith a case in which an 
 aperture of known area 
 is cut and fitted with a 
 tube. But it must be 
 remembered that, unless 
 the area of the aperture 
 is very large compared 
 with the equivalent ori- 
 fice of the chimney, the 
 introduction of the case 
 with aperture will affect 
 the flow by affecting the 
 total resistance. 
 
 Thus, either the 
 amount of air which 
 enters, or, what must be 
 the same, the amount of 
 air which leaves, can be 
 experimentally determined. If both can be measured the determination of the 
 one, of course, checks that of the other. We next require to know the tem- 
 perature of the air as it enters ; any ordinary thermometer may be used 
 for this ]purpose, but it must be used with discretion, for the reading of the 
 thermometer depends not only on the temperature of the air in which it is 
 placed, but also on the radiation it receives from hot bodies near ; moreover, 
 the temperature of the entering air may not be the same at every part of the 
 orifice. The determination of the temperature of the air with the highest 
 accuracy is a very difficult matter, but for the ordinary purposes of an investi- 
 gation of the ventilation circulation in a system, it is sufficient if the thermo- 
 meter be simply exposed in the air of the delivery shaft screened from direct 
 radiation, secured from contact with the sides of the shaft, and left until 
 no change of reading occurs during an interval of a few miniites. The thermo- 
 meter should be of course read tn situ, and not brought away from the point 
 at which the temperature is required until the reading is taken. 
 
 It remains only to consider whether the air is satisfactory as to quality. 
 In order to test this point a determination of the composition of the air must 
 be made, or, at any rate, the amount of impurity must be determined. For 
 information on this point the reader is referred to the article Am. 
 
106 
 
 HYGIENE 
 
 The amount of moisture in the air is an important element ; it can be 
 determined by any one of the hA'grometric methods referred to in the article 
 Meteorology. It is liable to vary considerably in different parts of the 
 circulation. 
 
 Fig. 35. 
 
 Direct Measurement op Head or Pressure Differences 
 
 45. Another element which can sometimes be measured directly is the 
 difference of pressure of air between the two ends of a duct, and from the 
 pressure difference, the head in feet can be easily deduced. The usual m- 
 
 struments for measuring the 
 pressure of air are not, as a rule, 
 sufficiently sensitive for the pur- 
 poses of ventilation-measure- 
 ment, as the pressure differences 
 are very minute. In some cases, 
 however, where the head re- 
 quired is large, as, for example, 
 in the ventilation of mines, a 
 syphon water-gauge — a U tube 
 containing water in the bend and 
 having one hmb connected by 
 tubes with one end of the ventila- 
 tion system and the other limb 
 open to the other end — will serve 
 to give the pressure in inches of 
 water by reading the difference 
 of level of the water in the two 
 limbs. 
 
 An aneroid barometer read- 
 ing to one-thousandth of an inch 
 can also be obtained, and this 
 may be used for observations in 
 examining the ventilation of a 
 house ; but with such an instru- 
 ment, indicating as it does the 
 pressure of the air where it is 
 placed, a double observation is 
 necessary to get the pressure 
 difference for the tAVO ends of a 
 duct. 
 
 There are numerous devices 
 which have been adopted for 
 increasing the accuracy of the 
 reading of the syphon water-gauge. In one modification the one limb of the 
 gauge is expanded into a large square box, while the other is a vertical glass 
 tube in which the rise or fall of the water can be measured by the distance 
 through which a sharp needle-point originally set at the surface of the water, 
 forming the end of a micrometer screw, has to be moved in order that it shall 
 again be at the water- surface. The adjustment of the point can be identified 
 with very great precision, because the image of any object formed by reflection 
 at the water surface is distorted as soon as contact takes place with the point. 
 A figure of such an instrument taken from Peclet's ' Traite de la Chaleur,' 
 vol. i. § 523, is reproduced in fig. 35. 
 
 Fig. 36. 
 
WABMING AND VENTILATION 
 
 107 
 
 The identification of the position of the surface is still easier if the needle- 
 point be below the surface and brought up to it by the motion of a screw, 
 the most minute elevation of the point above the surface being readily 
 perceived. In this case the reading can still be made by a micrometer screw 
 if the needle is bent into a hook form so that the point turns upwards. A 
 modification which dispenses with the necessity for a screw has been de- 
 signed by Mr. H. Darwin, of the Cambridge Scientific Instrument Co., and 
 a model constructed and tested by the writer of this article. In this in- 
 strument (fig. 36) the needle is fixed to the bottom of a water or oil vessel 
 and the measurement is carried out by observing how much water must be 
 added or removed in order to bring the point of the needle to the surface 
 again after it has been protruded or withdrawn by the alteration of level duo 
 to the difference of pressure. The amount of water which would be required 
 for this purpose is determined by finding the extent to which a plunger, a 
 uniform and graduated glass rod, must be pushed down or withdrawn from a 
 small well formed by a vertical tube communicating with the water vessel. 
 From some tests of the instrument made for the Author by Mr. A. Schneider, 
 of Emmanuel College, it appears that the instrument will give readings to 
 within one-three-thousandth of an inch. 
 
 Another modification of the syphon gauge which increases the sensitiveness 
 
 Fig. 37. 
 
 ■consists in using a wide vessel for one limb of the gauge and for the other 
 a long inclined straight tube. As the dift"erence of pressure corresponds to a 
 difference of vertical height of the two water surfaces, the water has to traverse 
 a greater length of inclined tube than of a vertical tube in order to produce 
 the same difference of level ; indeed, the length of tube traversed by the liquid 
 in an inclined tube is equal to the vertical difference multiplied by 1/sin i, 
 where i is the inclination of the tube to the horizontal. The area of the 
 ■surface of the water in the other limb must be very great in order that the 
 ■elevation or depression may practically take efi^ect solely in the inclined tube. 
 A form of this apparatus used by M. Peclet, and described by him in his treatise, 
 vol. i. § 524, is represented in fig. 37. 
 
 Many other arrangements for the measurement of small differences of 
 pressure have been designed, some of which are described by Peclet, vol. i. 
 chap. xi. 
 
 Examination of the Local Cikculation of Air 
 
 46. While it is in many cases comparatively easy to determine the total 
 amount of air supplied to a room, the testing of the second condition laid 
 •down above as being requisite for successful ventilation is by no means easy. 
 We have no satisfactory means of tracing the course of the air from its 
 
108 HYGIEXE 
 
 entrance to its exit, and determining its state as to temperature, moisture, 
 and impurity as it flows. The motion of the air is not, strictly speaking, 
 steady in an occupied room, for the velocity and state of the air vary from 
 time to time. The representation, by means of a diagram, of the circulation 
 in a room is almost as difficult as its determination. Any sectional plan can 
 only satisfactorily represent the flow in that section, and the flow in one 
 plane section cannot afl'ord an adequate indication of the whole circulation 
 in the room. It is probable that the difficulties which are referred to above 
 are responsible for the diagrams employed in illustration of the principles of 
 ventilation being frequently, more strictly speaking, finger-posts to show where 
 the air is intended to go than actual tracks of the air. Much interesting 
 information is, however, always to be obtained even from the little that can 
 be learnt of the direction and magnitude of the motion of air in different parts 
 of a room. There are many ways in which information can be got, though none 
 of them are completely satisfactory. The air from dift'erent points can be 
 analysed and its temperature can be ascertained, though there are not easy 
 observations in a room of any considerable size and height. Further than 
 that, accurate numerical measurements are not really practicable. A 
 very light wind vane, consisting of a wire with a paper tail, balanced on a 
 needle-point standing in a glass cup, is extremely sensitive to horizontal 
 motion, and indicates by its oscillations whether there is vertical motion too. 
 For observations of vertical motion, a piece of cork, carrying four inclined mica 
 wings, surrounding the end of an inverted thin glass test tube, can be supported 
 by a needle-point and move with so little friction that it will easily show the 
 air current rising from the hand placed several feet under it, and by the- 
 rapidity of its rotation indicates satisfactorily, though roughly, the vertical 
 velocity of the air which passes it. By having a sufficiently large number of 
 such vanes and mica- spinners placed at different heights and different 
 positions in a room, a very good idea can be formed of the course of the air 
 currents, which, however, it is very difficult to adequately represent on 
 paper. There are various ways in which the currents may be made more 
 or less visible by loading them with smoke or fumes which are carried 
 along with the current. Smouldering cotton velvet is recommended as being 
 useful in this way ; the Commissioners of 1857 ' placed ammonia in a dish 
 in the path, of the current and loaded the air passing it with hydrochloric 
 acid vapour. Some other fuming chemical compounds, as stannic chloride,, 
 might be used, but all these are liable to change the current to a certain extent,, 
 and without exceptional illumination the flow is not visible for a long dis- 
 tance. Balloons, silk fibre, and down are also sometimes employed, and 
 when used discreetly may afford valuable observations ; but none of them 
 seem quite so trustworthy as the wind vanes and mica-spinners mentioned 
 above. 
 
 The most sensitive method of detecting the motion of air for some- 
 purposes is by means of the sense of smell ; the path of air through the 
 difl'erent rooms of a house can be easily traced by burning a little incense or 
 a pastille (which can be bought at any chemist's) near an inlet. In this case 
 we have, of course, auxiliary information as to the path by which smell 
 comes into a room if at all, viz. through crevices or openings which can, as a 
 rule, be identified. It cannot be used with much effect in a large room, as 
 the path of currents could only be traced by the observer moving about, and 
 this moving would entirely destroy the steadiness of the currents and spoil 
 the observation. The sensation of a cold current, especially as perceived by 
 
 ' Report of Farliaincntarij Comviission on War/iiiiig and Ventilation of DivellingSy 
 1857 
 
WABMING AND VENTILATION 
 
 109 
 
 a moistened finger, may also be used to furnish information as to the direction 
 of flow in any accessible position. 
 
 47. It will be gathered from the above that the information which can be 
 obtained as to the local circulation of air through a room is not at all com- 
 plete, and is difficult of representation ; but with one or other of the apparatus 
 mentioned, and by taking advantage of casual indications (such as the deposit 
 of dust on walls, which is a good indication of the course of warm air), an 
 observer may make himself tolerably well acquainted with the course of 
 
 currents through the room. We reproduce diagrams (figs. 38-41 and Plate I.), 
 representing the results of experiments of this kind, which will serve to indicate 
 the general features that may be expected in any case. The first two diagrams 
 refer to the circulation of air and the distribution of temperature in a room 
 with an open fire, which were very fully investigated by the Commissioners on 
 Warming and Ventilation of Dwellings, 1857. The diagrams are taken from 
 their report. The first (fig. 38) shows the direction of flow along the ceiling 
 by the direction of deflexion of silk fibres attached to the ceiling, while the 
 amount of the deflexion is indicated by numbers written against the lines 
 
110 
 
 HYGIENE 
 
 1 
 
 representing the fibres as seen in plan ; the second (fig. 39) shows the flow 
 in a vertical section through the middle of the room by representing the 
 deflexion of silk fibres and also by some lines of flow ; the temperature in 
 various positions is also indicated. Fig. 40 represents the circulation in a. 
 lecture-room in Cambridge heated by hot-water pipes under the tiers of seats, 
 and ventilated through open woodwork in the ceiling into a wooden channel, 
 
 extending round three sides of the room, and communicating with a chimney 
 at the corner marked F. In this room no special inlets are provided, some air 
 comes in at A from the lobby, and passes over the hot-water pipes ; the rest 
 of the fresh air required comes in by the joints in the windows ; the doors 
 in this particular instance generally act as outlets in consequence of the 
 suction from other parts of the buildmg. 
 
 In the diagram (fig. 40) the full arrows show the flow in the plane of the 
 section, while the dotted arrows indicate currents near the wall. The strong 
 
WABMING AND VENTILATION 
 
 111 
 
 upward current of warm air at the back of the room is very clearly shown in 
 the room itself by a deposit on the walls and ceihng. 
 
 The most obvious conclusion to be drawn from the diagram is that the 
 air which enters from the chamber containing the pipes passes directly to the 
 extract flue (the velocity of exit is at the jrate of 300 cubic feet per minute) 
 without affecting the main body of the air in the room, which remains 
 practically unventilated and unwarmed. The circulation is very much 
 restricted for want of sufficient inlets. There are trap-doors in the ceihng 
 at C above the table, communicating with an airy lumber-room, and the 
 opening of one of these determines a shower of cold air falling directly upon 
 the table. The doors of the lecture-room then become energetic outlets. 
 
 The next diagram (fig. 41) shows the circulation on a stone well-stair- 
 case in the same building ; the doorways represented communicate with 
 corridors and rooms having large window area. There is a coil of pipes on 
 the ground floor. The diagram shows a hot ascending current of air passing 
 
 ViHTiLAnoH Flue 
 
 
 1 1 1 
 
 \ 
 
 t 
 
 \ 
 
 E 
 
 E 
 
 ^ 
 
 fe 
 
 E. 
 
 - Scatt.rFtlT - 
 
 E. 
 
 Fig. 40. 
 
 up the well of the staircase, and a sort of river of cold air flowing down the 
 steps and turning the corners, part of it finally passing down into the 
 basement. This is really part of a general circulation of air between the 
 hot-water coils and the windows of the whole building, and the circulation 
 can be easily traced, the hot air passing at the tops of the doorways, the cold 
 air at the bottoms. In this case also no special inlets are provided, so that 
 the circulation is mainly internal. 
 
 The circulation on a staircase of any house is generally instructive, and 
 a cold descending current from the chimneys and windows of the cold upper 
 rooms can frequently be shown to be active simultaneously vnth. a hot 
 ascending current, generally from the kitchen, and the two currents escape 
 mutual destruction, either by one going spirally round the other, as on the 
 staircase, fig. 41, or by the hot one passing over the cold one. It is this 
 complication of currents that accounts for the thorough diffusion of smells 
 in a house. I have found when experimenting with pastilles upon the 
 
112 
 
 HYGIENE 
 
 Fig. 41. 
 
WABMING AND VENTILATION 113 
 
 circulation in a house (Plate I.) that when a pastille was being burned on 
 the upper floor a layer of air twelve inches thick, flowing downstairs, was 
 charged with the smell, whereas at the height of five feet the smell of 
 cooking was going upstairs. I have attempted to represent the distribution 
 of currents on this staircase by a diagram (Plate I.), where a full arrow denotes 
 rising warm air and a dotted arrow descending cold air. The only means of 
 protecting one's self against such inconveniences, if they be regarded as such, 
 is to provide a competent inlet for every outlet head, and to provide an efficient 
 outlet head for every room where air is likely to be fouled, or charged with 
 disagreeable odours. 
 
 48. The examples represented in these diagrams, with those given in figs. 
 28, 29, and 30, § 31, are sufficient to indicate the two main difficulties of 
 ventilation Avhich arise from the magnitude of the space to be ventilated. They 
 may be called respectively internal circulation, the production of currents on 
 account of local differences of temperature by which warm air is carried away 
 from where it is wanted and replaced by cold air causing draughts ; and selec- 
 tive circulation — the name we propose to apply to the passage of air from an 
 inlet more or less directly to an outlet without replacing as fully as possible the 
 foul air of the room it is designed to ventilate. The objects, then, of an in- 
 vestigation into the ventilation of any room may be conveniently referred to 
 under the headings : sufficiency of supply, internal circulation, and selective 
 circulation. 
 
 The defects which may be included mider the second and third headings 
 are especially liable to be serious in large rooms, particularly when there are 
 local sources of heat and cold. In theatres they are often disagreeably 
 prominent, and the elaborate arrangements of M. Morin and others are 
 designed to obviate them. 
 
 Effect of Adjoining Eooms 
 
 49. It will be well here to call special attention to a matter which has been 
 frequently alluded to, namely, that the process of ventilation is a circulation 
 of air through a channel which must have two ends, each end being in the 
 open air. The investigation of the ventilation of any system is therefore 
 not complete until the two sections of communication of the circulation with, 
 the open air have been identified. 
 
 In investigating the circulation of any room, starting from the outlet 
 and going backwards to the inlet, we must retrace the course of the air until 
 we arrive at the ultimate inlet. This will often be found in adjoining rooms 
 or in closets communicating directly or indirectly with the room in question. 
 In respect of sanitary matters this is a very important consideration, and 
 constitutes a valid objection to the general principle of ventilation by suction. 
 Let us consider, for example, the circulation in a house in winter, in which 
 a number of rooms have fires, each of which causes a head, drawing air, 
 we will suppose, from the central hall or lobby (see Plate I.). Then 
 there will be, in consequence, a head between the central lobby and the 
 external air which will determine a flow of air through every orifice, great and 
 small, in proportion to its equivalent area, unless there is a countervailing 
 head. It follows that all closets, cupboards, rooms, &c., which have an 
 opening to the external air, unless provided with separate flues in which 
 a head is maintained, will contribute to the supply of air to the central lobby 
 from which the rooms, at any rate partially, draw their air. It is needless 
 to say that the air may be rendered quite impure and unfit for use on its way 
 to the lobby and the room that receives it. Experiments can easily be made on 
 this point by loading the air in the places where there are inlets with incense 
 vol, I. J. 
 
114 HYGIENE 
 
 or some strongly smelling vapour, as that of oil of peppermint, or even tobacco- 
 smoke. I have given one instance, and there are probably many in which 
 experiments of this kind have shown that the supply of air for the fires of 
 most of the living rooms Avas mainly drawn from the w.c, which had been 
 provided with two openings to secure its ample ventilation. In the absence 
 of special inlets both these openings were acting as inlets for the house, and 
 the current of cold air could be easily traced under the door of the closet 
 and along the floors of the lobby, under the doors of the living rooms to the 
 fires ; when it got near the fireplace it was warmed and rose, and so the 
 odour gradually permeated the whole room. 
 
 The effect of adjoining rooms with apparatus for separate heads for 
 circulation is frequently very conspicuous. In one instance that has come 
 under my notice a lobby is heated by a ventilating gas-stove with one 
 flue for the supply of fresh air and another for carrying away the products 
 of combustion. In the adjoining room is an open tire. If the gas-stove is 
 lighted when the fire is burning, although the door between the two be shut, 
 no upward current is established in the outlet of the stove ; it continues to act 
 as an inlet for the next room ; the products of combustion come straight out 
 into the lobby and gradually pass into the adjoining room, where they are 
 readily perceived, and this continues for an indefinite period unless free 
 communication be made between the lobby and the external air by opening 
 the door, when the products of combustion pass up the flue, and there 
 establish a head sufficient to overcome the suction of the next room, and 
 thereafter the desired circulation persists though the outer door be shut.^ 
 
 Aetificial Lighting and its Effect on Ventilation 
 
 50. We have already noticed that every local source of heat produces con- 
 vection currents in its neighbourhood. Of such local sources artificial lights 
 are the most effective. The disturbance which they produce in the air 
 depends of course upon the amount of heat which the glowing substance 
 communicates to the air surrounding it, and consequently an incandescent 
 electric lamp is distinguished among aU artificial lights by the smallness of 
 the interference with the ordinary course of the air which is caused when the 
 light is used. It is further distinguished by the fact that being inclosed in 
 a glass envelope the glowing filament produces no effect upon the air except 
 the small amount of heating ; it requires no oxygen for the maintenance of 
 the light, and therefore does not use up the air of the room, whereas other 
 artificial lights use the oxygen of the air and produce carbon dioxide gas. 
 The following table shows the comparative effect of different sources of 
 artificial light in respect of the heat which they produce, and the heat pro- 
 duced by a human being is likewise included for the sake of comparison : — 
 
 Table VII 
 
 Source of heat 
 
 Heat developed per hour 
 
 Cubic feet of carhou 
 dioxide gas per hour 
 
 Incandescent lamp (16 candle-power) 
 Average human being 
 
 Candle 
 
 Average gas jet (4 cu. ft. per hour) 
 
 200 lb. F. units 
 
 284 
 
 291 
 
 2784 
 
 
 •6 
 
 •45 
 8 
 
 It follows at once that a number of gas jets produce as much heat as a 
 coal fire, and hence when burned in a room may entirely change the course 
 
 ' For the explanation of this effect see above, § 41. 
 
WABMING AND VENTILATION 115 
 
 of the currents of air, while at the same time they dehver a large amount of 
 carbon dioxide gas, sulphur dioxide gas, and other impurities, so that, accord- 
 ing to Wolpert, for every cubic foot of gas burned 1800 additional cubic 
 feet of fresh air should be introduced. It is therefore clear that a system 
 of ventilation designed for a room in the daytime, when no artificial light is 
 used, ought not to be expected to be successful when a number of gas jets are 
 burning in the room. 
 
 If a considerable volume of gas be burned in a room that is unprovided 
 with special exit tubes for the burnt gas, an internal circulation is set up by 
 each gas jet ; the circulation does not, however, extend below the level of the 
 burners, so that assuming for a moment that the burners are on the same 
 level the air in the room is divided into two portions by the horizontal plane 
 of the burners (see § 39), and as the combustion proceeds the air of the upper 
 part is rapidly converted into a thick layer of heated foul air, which no human 
 being could endure for any length of time, and the lower section is com- 
 paratively uninfluenced. This description is somewhat exaggerated, for the 
 local circulation produced by the fire, if there is one, and by other sources 
 of heat, and the process of difi'usion, cause the products of combustion of the 
 gas to be gradually disseminated, but the mixture is by no means complete 
 in ordinary cases. In order to remove the vitiated air the outlets must be 
 placed as near to the ceiling as possible ; if they are flues they form suction 
 outlets, which require a corrresponding flow of air to the room.^ Un- 
 doubtedly the most satisfactory arrangement is to provide special outlets 
 to carry awa}'' the products of combustion directly from the burners, but that 
 does not alter the effect on the ventilation in respect of the greater total 
 circulation of air required, if other causes, which are used when there is no 
 gas, are still active when the room is lighted ; so that the problem of 
 ventilating a room for daylight and gas light is really a double one, and it 
 may not be possible to provide a satisfactory solution of both parts of it by 
 jneans of a single arrangement. 
 
 Summer and Winter Ventilation 
 
 51. Somewhat similar remarks apply to the ventilation of buildings in 
 summer. In an ordinary house in winter the chimneys are the warmest parts, 
 and hence, even when no fire is burning, there is always a certain amount 
 of head due to he higher temperature, although the motion of the air may 
 be reversed in consequence of a more powerful head in an adjoining room. 
 But in the daytime in summer the chimneys are frequently the coldest 
 portions of the house, whereas the sun acting on the external walls produces 
 a head causing, with open windows, a circulation downward through the 
 chimneys and through the window^ upwards outside the house. This effect 
 is very frequently perceptible by the smell of soot that occurs on very hot 
 days, so that the winter arrangement for ventilation entirely breaks down 
 unless some special device is adopted. The obvious plan in this case is to 
 restore the upward head in the chimneys of those rooms that require 
 ventilation during the day, by gas jets in the chimneys or some other means, 
 -or to stop up the chimneys of those rooms and trust to open windows alone 
 for any ventilation that is necessary. The amount of gas that is required 
 -to be burned for the purpose of producing a head in a shaft is given on p. 84. 
 
 * For the condition that such apparatus should act as desired see § 41. 
 
 I 2 
 
116 HYGIENE 
 
 Summary of Conditions to be Satisfied to secure Efficient 
 
 Ventilation 
 
 1. Quantity of Air Required 
 
 52. The estimates of the quantity of air to be supphed are based upon the 
 following assumptions : — i. That the air of a room must not be permitted to 
 contain more than two volumes of carbon dioxide gas per 10,000 in excess of 
 that contained in the outside air. ii. That the carbon dioxide generated by 
 respiration or combustion is diffused uniformly throughout the room, as like- 
 v\dse is the air which enters, so that the volume to be supplied is that required 
 to dilute the impurity, the average production of CO., per head of average 
 population being -Q cubic foot per hour. On these assumptions the quantity 
 of air to be supplied per hour for a room in continuous occupation is 3000' 
 cubic feet per average occupant, or more particularly : 
 
 9800 cubic feet per hour for each adult male in hard work. 
 4750 ,, ,, ,, ,, ,, in light work. 
 
 3600 ,, ,, ,, healthy adult male during repose. 
 
 3000 ,, ,, „ ,, ,, female ,, 
 
 2000 „ ,, „ healthy child during repose. 
 
 In hospitals the supply should exceed the above estimate by one-fourth 
 in ordinary cases, and in special cases it should be doubled. 
 
 On the same assumptions, in churches, lecture-rooms, and theatres, which 
 are only used for a limited time, and are initially filled with fresh air, respira- 
 tion can go on for some time before the whole of the air contained reaches 
 the limit of respirable impurity, so that the quantity of air necessary during 
 the first hour is less than that for succeeding hours ; the amount depends in 
 this case upon the initial allowance of cubic space per person. For an 
 average audience requiring 8000 cubic feet per hour each, for continuous 
 occupation Dr. de Chaumont calculates the following table of the relation 
 between the quantity of air required in the first hour and the initial cubic 
 space : — 
 
 Number of cubic feet 
 Cubic space in cubic of air necessary for 
 
 feet per person ventilation during first 
 
 hour of occupation ' 
 
 100 2900 
 
 200 2800 
 
 500 2500 
 
 1000 2000 
 
 Every cubic foot of gas burned per hour requires 1800 cubic feet of fresh 
 air to be supphed if the products of combustion mix with the air of the room. 
 One candle burning requires about 150 cubic feet of air per hour, and an 
 oil lamp requires as much as a gas jet in respect of dilution of the CO2, but 
 frequently no allowance is made for candles or lamps. The reason for this 
 is not apparent unless it be that the products of combustion of candles and 
 lamps are (under favourable circumstances) without smell or taste ; whereas 
 a burning gas jet produces effects which indicate, without special analysis, 
 that the limit of respirable impurity has been exceeded. 
 
 ' When the air is drawn by a very wide chimney, 60 feet high, with the temperature of 
 the air in it 212° F., and the outside air at 32° F., this estimate requires a clear orifice of 
 about 7 square inches per person. This is almost impracticable, and consequently an 
 endeavour should always be made to take advantage of the local circulation to have the 
 occupants in the parts of the room where the air is fresher than elsewhere. 
 
WABMING AND VENTILATION 117 
 
 2. The Quality of Air Beq^oired 
 
 53. Purity. — It is essential that the air should be drawn from a pure 
 source, and if necessary further purified before admission to tlie rooms. To 
 secure purity it should be drawn from vertical openings, preferably in a north 
 wall, from some considerable height above the ground, free from local con- 
 tamination. The openings may be protected by louvres. The most serious 
 impurities of outside air lie in the dust which often contains the gsrms of 
 disease. This may be partially removed by filtering through canvas or by 
 other means suggested in § 13. 
 
 54. Temperature. — The temperature of the air which enters a room re- 
 quires regulation according to special circumstances, and for this purpose the 
 entering air should be warmed, and provision should be made for mixing cold 
 fresh air with the warm before entry into the room in a proportion adjustable 
 by a register- door, or valve. 
 
 The temperatures which should be maintained in various buildings are 
 given by Morin ' as follows : — 
 
 Schools . . . . • . . . . 15° C. 59° F. 
 
 Hospitals 16°-18° 61°-64°-5 
 
 Accident wards 12° 54° 
 
 Shops, barracks, prisons .... 15° 59° 
 
 Theatres, assembly-rooms, lecture-rooms . 19°-20° 66°-68'^ 
 
 But it must be remembered that no temperature will suit all persons ; a 
 room that seems intolerably hot to a person freshly entering after a brisk 
 walk on a cold day may seem inadequately warmed to those who have been 
 •engaged in it for some hours in sedentary occupation. 
 
 55. In some instances the warming of buildings is carried out entirely by 
 liot air ; in such cases the entering air must be at a temperature above the mean 
 temperature to allow for losses of heat through windows and walls. Such a 
 plan does not seem the most desirable. Hot air warming is often said to be 
 dirty. The hot air moving over cold surfaces produces dust deposits, though 
 this may be an advantage, as it is a means— not a very satisfactory one — of 
 getting rid of the dust from the air ; but there are advantages in heating the 
 walls and furniture by means of direct radiation and not by hot air contact, for 
 this promotes circulation of air, even in remote corners, and prevents loss of 
 heat from persons by radiation ; so that it would seem advisable where such 
 a plan is feasible to allow the air to enter at a temperature of a degree or so 
 helow that of the room and make up the necessary supply of heat by open 
 fires or hot- water pipes. There are incidental advantages m this method, as 
 it reduces the local circulation which depends on the differences of tempera- 
 ture of air in different parts of the room. 
 
 The introduction of fresh air direct from the outside without warming it 
 at all is altogether impracticable if draughts are objected to. 
 
 The details of different arrangements for warming air will be considered 
 later. They may be classified as air-stoves, and batteries of hot water, or 
 steam pipes. It is uneconomical to carry heated air any long distance, as the 
 amount of heat conveyed per cubic foot of air raised to a given temperature 
 is so small and so easily lost in transit. On this account Morin considers 
 their availabihty limited to a horizontal range of 12 to 14 metres (40 to 45 
 feet), measured horizontally from the heating apparatus ; it is preferable 
 in a large block of buildings to carry the heat by means of water pipes and 
 form local batteries of pipes whereby to heat the air immediately before it is 
 
 > Manuel de Cliauff. &c. p. 186. 
 
118 HYGIENE 
 
 brought into use than to have a stove m the basement and distribute the- 
 heat by distributing the air supphed by the stove. 
 
 56. Vitiation of Air by Heating Apparatus. — In -^-arming the air care 
 must be taken to secure that it is not at the same time vitiated. It is a matter 
 of common experience that if air is heated by being passed over a red-hot iron 
 pipe it becomes ' burnt ' and extremely disagreeable. 
 
 General Morin ^ has investigated the cause of the vitiation produced by 
 iron, especially cast iron, when raised to a dull red heat. He shows that 
 there is produced in the air an appreciable quantity of carbonic oxide — a 
 highly poisonous gas — which results when coal is burned with insufficient 
 oxygen, or when carbon dioxide gas is passed over red-hot coal or coke. It is 
 to this gas that the poisonous action of charcoal braziers and coke fires is 
 due. The presence of the carbonic oxide may be due to four independent 
 causes, which may act concurrently, viz, : — 
 
 1. The permeabihty of the iron for this gas at high temperatures. 
 If any carbonic oxide is formed in the stove some of it will pass out through 
 the red-hot iron to the external air. 
 
 2. The dh-ect action of the oxygen of the air upon the carbon of the 
 cast iron. 
 
 3. The decomposition of the carbon dioxide gas of the atmosphere by the 
 red-hot metal. 
 
 4. The incomplete combustion of organic dust floating in the air. 
 
 The production of carbonic oxide does not take place unless the iron is 
 red hot. The air supplied for ventilation should therefore never pass over 
 red-hot iron ; all iron parts of a stove that are liable to become heated to 
 redness should be lined with fire-brick or other refractory substance. 
 
 In such a case, evidently, no ventilation might be better than supplying 
 the place of moderately foul air by air rendered poisonous by the presence of 
 carbonic oxide, which is deleterious if breathed for a considerable time, even 
 if in minute proportion. 
 
 Moreover, air passing over highly heated surfaces frequently acquires 
 disagreeable properties which may be caused by the action of the heat upon 
 the dust of the air, or that deposited upon the heating surfaces. These 
 should therefore be so placed that they can be inspected and regularly 
 cleaned. 
 
 57. Humiditij. — When the external temperature is low, the air supplied 
 will require to be moistened as well as warmed. The average humidity of 
 air in these islands is about 75 per cent., so that the pressure of water 
 vapour in the room must be about three-quarters of the saturation pressure 
 indicated on the diagram on p. 46, or the pressure indicated by a point half- 
 way between the corresponding points of the two curves there plotted. The 
 diagram will also show what is the maximum possible vapour pressure in 
 the external air at this temperature, and thus the necessity for moistening 
 can be estimated. Part of the necessary moisture will be supplied by the 
 actual respiration itself, but more may be, required which may be provided 
 by injecting clean steam or water spray, or simply by exposing a w^ater 
 surface to the air. 
 
 3. Positions of Inlet and Extract Flues 
 
 58. The fundamental condition to be satisfied is that the air which leaves 
 the room by the extract flues should be, in as far as there is any difl'erence, 
 the impure portion, as contrasted with the pure entering air. 
 
 The differences of detail which the problems in ventilation present mak& 
 * Mimoires de VAcadimie des Sciences, vol. xxxviii. See Manuel, &c. p. 113. 
 
WABMING AND VENTILATION 11& 
 
 it difficult to formulate any precise rules as to where tlie air should enter 
 or leave the room in order that this condition should be satisfied, and 
 authorities differ, to a certain extent, on the point. The main object of 
 ventilation would be secured if the air which has been once respired were dis- 
 placed in such a way that it cannot be again passed into the lungs, but is 
 directly carried to the outlets. We cannot, however, treat each occupant of 
 a room like a gas jet, and provide him with a separate exit pipe. The next 
 best thing seems, at first sight at any rate, to get the exit pipes as near to 
 the source of contamination as possible, so that the respired air may be 
 forthwith removed. This plan is adopted with obnoxious gases produced on 
 the table of a chemical lecture-room. An opening in the table provided 
 with a strong down draught removes nearly all the offensive vapour in a 
 very satisfactory manner, and some similar plan may be adopted with the 
 auditory. The expired air is driven out through the nostrils and mouth 
 with very considerable velocity, producing eddies and rapid mixture with the 
 surrounding air, so that the upward force acting on the impure mixture due 
 to the increase of its temperature is very small. The direction of projection 
 of the air for a person sitting or standing (with the head in a natural 
 position or inclined downwards as in writing) is downwards, so that by each 
 act of expiration a person projects into the room a quantity of used air 
 which mixes with the air of the room somewhat beneath his mouth, and 
 this mixed volume, if left in still atmosphere, begins to rise but very slowly, 
 and a very slight downward current is sufficient to carry it further downward. 
 A number of persons sitting or standing together will produce a layer of 
 impure mixture, and a general downward movement of very small velocity 
 produced artificially will be sufficient to carry the layer of mixture below the 
 heads of the persons, in spite of the upward effect produced by the natural 
 heat of the bodies ; so that in the case of a number of persons on the same 
 level the most direct plan of carrying away the impure air is to establish 
 a general downward current by means of outlets in or near to the floor. 
 The total area of these outlets must be so great that there is no down- 
 ward motion of the air perceptible as a draught in their neighbourhood. 
 Similar considerations apply when the audience is arranged on tiers of seats, 
 as in an amphitheatre. The position of outlets thus indicated is suitable 
 for the cases of lecture-halls, concert-rooms (of not more than two floors), 
 schools, churches, and chapels. The openings into the extract flue may be 
 made under the seats either on the floor or in the risers of the seats at the 
 back, and advantage should be taken of the erection of desks, book-rests, 
 &c., to avoid the inconvenience of the openings being so near the feet as to 
 cause a sensation of draught. Moreover, the openings must be very numerous 
 and well distributed, and so proportioned in size that each one acts equally. 
 The entry of fresh air should be so arranged as to prevent local circula- 
 tion and selective circulation, and to be sufficiently far away from the 
 persons to avoid direct draughts. The most potent cause of local circulation 
 in cold weather in churches and large halls is the large area of windoAv 
 space, and it would be well to fix the position of the warm air uilets with 
 special reference to this point. It would probably be completely obviated 
 by arranging a hot-air inlet a short distance under each window, and this 
 position for inlets would seem in most cases to satisfy the conditions 
 specified. In that case the descending cold air would have to be reckoned — 
 partly at any rate — instead of fresh cold air taken from outside to mix with 
 the warm air supplied. The cooling effect of windows can of course be 
 reduced, as indicated on p. 41, by double glazing. If, by that means or 
 some other, the windows may be left out of account — a circumstance of very 
 
120 HYGIENE 
 
 rare occurrence — the position of the inlets may be dictated by consideration 
 merely of avoiding draughts and selective circulation. The outlets being at 
 the floor level, the inlets should be well above the heads of the audience, 
 and, if slightly colder than the air of the building, the incoming air should 
 be directed upwards, if warmer, horizontally or slightly downwards. 
 
 For dining halls the case is somewhat dift'erent. The heat of the dishes 
 and frequently of caudles on the tables makes a much more intense local 
 circulation, and exit orifices in the ceiling should be provided to meet the 
 case. These may be in addition to or instead of the floor outlets already 
 suggested. In considering the supply of fresh air, the space over each table 
 must now be regarded as an upcast shaft of impure air which must be 
 allowed to travel directly to the upper ventilators ; the inlets may be therefore 
 high up, in such positions as to avoid these rising columns of air, and in 
 the ventilation system for this case we must make use of the local circulation 
 and not simply trust to the motion of parallel horizontal layers of air. 
 
 The lighting of a room by gas requires special treatment. The gas 
 produces local circulation, and if a separate extract flue is provided it is 
 generally in a j)osition most unfavourable for general ventilation ; the whole 
 air of a large hall must be very impure before a central chandelier is 
 eflective in removing impurity. Under low galleries the beneficial effect of 
 a gas jet with separate flue is more direct provided that the inlets are so 
 placed that selective circulation is avoided. Under the circumstances it is 
 better to make the ventilation independent of the lighting arrangements, 
 and to enclose the gas lights, as is done on the Wenliam gas-light system 
 and other regenerative gas burners, so that only as much air is supplied to 
 the gas as is required for the combustion : this may be drawn either from 
 the room or separately from the outside. 
 
 In theatres the problem becomes unusually comphcated in consequence 
 of the great intensity of the local circulations from the lighting and the 
 proximity of many corridors and rooms, and the necessary smallness of the 
 allowance of cubic space per head of the audience. 
 
 The arrangement proposed by Morin^ includes a series of outlets in the 
 galleries, the boxes, and the floor of the pit, and along the front of the stage, 
 and inlets delivering into the area, between the joists of the floor of every tier, 
 with special outlet for the gas chandelier. 
 
 The position of inlets for hospital wards requires also special consideration. 
 General Morin (' Manuel,' p. ii48) recommends them to be placed at the head 
 of the beds at the floor level, but in the side walls, allowing at least one for 
 every two beds in ordinary wards and one for every bed in wards requiring 
 special ventilation. But De Chaumont (Parkes' ' Hygieiie,' p. 186), on the 
 ground that the breathed air rises rapidly, not only on account of its tem- 
 l^erature but from the direction of projection, recommends that the point of 
 discharge for patients in bed should be above, and the fresh warm air supplied 
 from under the beds. In a plan said to be successful in America the outlets 
 are under the beds and fresh air is supplied at the bed head to each patient. 
 It remains probably still a matter of opinion which of these plans should be 
 adopted. The reasojs Avhich we have given for placing the outlet at a low 
 level in the case of a lecture-room or haU are not strictly applicable to 
 hospital wards, as the beds form obstacles to the downward flow, and each 
 patient might cause a local circulation that would interfere with the satis- 
 factory working of the plan. Possibly outlets at middle height and inlets 
 both at the top and bottom would satisfactorily solve the problem. 
 
 ' See the diagrams for the Theatre Lyrique and Theatre de la Gait6, Etudes, vol. i. 
 lilates siv. xv. 
 
WABMING AND VENTILATION 
 
 121 
 
 A 
 
 4. Provision of a Suitable Head for Extracts and Inlets. Correct 
 Numerical Proportion hettveen Areas of respective Inlets or Outlets. 
 
 59. Three types of plan may be considered : 
 
 1. Injection of air by a blower from a central air chamber, leaving the 
 .air to find its way out of the outlets by the secondary head, due to increase 
 of pressure in the system. 
 
 2. Suction by a single main shaft. The outlets in this case govern the head 
 for circulation of the different rooms, and the air finds its way through the inlets. 
 
 3. Separate heads for the different outlets which act as upcast shafts, 
 the head being due to the difference of temperature of the air in the flues and 
 the external air. 
 
 Any particular case then may be a combination of two or more of these 
 
 three types. The comparative advantages of the different methods will be 
 
 treated later. What we now wish to point out is that in any case one of the 
 
 conditions of success is that the head for any orifice, inlet or outlet, must be 
 
 satisfactorily provided,^ 
 
 and the areas of inlets 
 
 and outlets must not 
 
 be taken at haphazard, 
 
 and there must be a 
 
 proper numerical pro- 
 portion between the 
 
 •equivalent areas of the 
 
 different orifices, the 
 
 rules for the calculation 
 
 of which are given 
 
 above, § 20. If we 
 
 liave a main channel, A 
 
 (fig. 42), with branch 
 
 ■channels, Aj, A2, A3; 
 
 A4, the resistances of 
 
 the channels must be arranged by adjusting the equivalent areas of the orifices. 
 
 o,, 02, 03, 04, so that there is the same head for the flow required, between 
 the rooms into which the orifices lead and the point A ; otherwise one of the 
 
 <3hannels will ' draw ' more actively than the others. The area of the channel 
 A must also be increased when a new channel joins it, so that the velocity 
 of motion of the air may be kept nearly uniform throughout its length, and, 
 further, when the ventilation is by a number of separate heads, the heads 
 must be equahsed, or at least sufficiently nearly so to prevent one over- 
 powering the others. 
 
 The areas of inlets and outlets must also be suitably related to each 
 other. The area of one or other of the two is decided by calculation of 
 the head required to produce the given circulation in the most economical 
 manner. In calculating the head, taking for example the case of ventilation 
 by an open fire, account must be taken of the loss in consequence of the 
 friction of the inlets, and thence it follows that the greater the area of the 
 inlets the better, so that the exact equality of area of the two is not a 
 thing to be striven after for its own sake. What we mean by suitably pro- 
 portioning them is that the inlets should be sufficiently large to secure that 
 
 ' It seems hardly necessary to state that no efficient ventilation can be secured by any 
 number of orifices unless there is an adequate head, but a recent experience in a room 
 ^ith an open chimney (without fire) and open window leads one to reflect on the improve- 
 ment that might have resulted if a head had been established by putting a paraffin lamp 
 in the fireplace. 
 
 Fig. 42, 
 
122 
 
 HYGIENE 
 
 the velocity shall not be too great. According to Morin (' ]\Iannel,' p. 193),. 
 the velocity of efflux should be about three feet a second, and the velocity 
 of hiflux two feet a second for inlets pointed downwards, and not more than 
 three feet a second if pointed upwards or horizontally at a height of twenty 
 feet above the heads of the occupants. If this rule be followed the inlet area 
 must be capable of being one and a half times as great as the outlet. 
 
 5. Completeness of Gircidatlon 
 GO. In determining the plan of ventilation of a room the whole building 
 must be treated as one system, and the plan of circulation drawn out for the 
 whole. It is not sufficient to have a system which is only in working 
 order for a room so long as all the doors are shut, if one of the conditions 
 of the use of the room be that the doors sliall be frequently open. This 
 condition is especially peremptory in the case of domestic houses, and it 
 practically amounts to requiring every outlet to be supplied with an adequate 
 inlet, so that there shall be no head between different rooms. The ideal 
 arrangement for a large building would be to combine the ' plenum ' and 
 ' vacuum ' methods in such a way that there should be no head between the 
 interior of any one of the rooms and the outside of the building. 
 
 APPAEATUS FOE, WAEMING AND FOE COOLING 
 
 61. Hitherto we have been deahng mainly with the principles of ventila- 
 tion and have assumed that the difficulties in the way were only those whicb 
 arose from the unalterable properties of air and other materials that we had to 
 deal with. We have supposed heat to be distributed wherever it Avas required 
 and in whatever quantity. We have in fact disregarded the important practical 
 details of the apparatus that must be used for the distribution of air or heat, 
 and questions of expense or economy have not been dealt with. We now 
 proceed, however, to consider more closely the practical side of the matter. 
 We will deal first with the production and distribution of heat, although com- 
 plete separation between warming and ventilating cannot be accomphshed. 
 
 62. Artificial heat is produced, as we have seen already (p. 35), almost 
 entirely by combustion. Different kinds of fuel differ considerably in the 
 amount of heat which is developed by the combustion of a given quantity, and 
 the prices of different fuels are also widely different. We give accordingly a 
 table (after Morin) of the heat in lb. F. units developed by the combustion of 
 1 lb. of different kinds of fuel, and the number of lb. F. units of heat produced 
 by the combustion of the amount in each case which can be bought for one 
 penny at ordinary prices. It is of course a rough table, as the prices vary 
 considerably m different localities. 
 
 Table VIII. 
 
 Fuel 
 
 No. of lb. F. units of heat 
 produced by the combus- 
 tion of 1 lb. of fuel 
 
 -□ . , f , No. of lb. F. units 
 Price of fuel for one penny 
 
 Coal. 
 Coke. 
 Ppat (dry) 
 Dry wood . 
 Petroleum 
 Coal gas . 
 
 14,000 
 12,600 
 
 9,000 
 
 7,200 
 21,000 
 675 (per cu. ft.) 
 
 20s. ]-er ton 
 
 13s. 4fZ. par ton 
 
 Id. per 5 lb.' 
 
 25s. per ton 
 
 10^. per gallon 
 
 3s. per 1,000 cu. ft. 
 
 131,000 
 176,000 
 45,000 
 54,000 
 17,220 
 18,800 
 
 This table shows the total quantity of heat that is generated by the com- 
 plete combustion of the fuel. Thus when a gas jet or petroleum lamp is burned 
 in a room the table gives us the amount of heat supplied, all of which helps 
 to warm the room in some part or other. The other fuels are now, however,. 
 
 • Cambridge price. 
 
WASHING AND VENTILATION 123 
 
 always burned in stoves, with chimneys for carrying away the products of 
 combustion, and every pound of fuel requires for its combustion a definite 
 quantity of oxygen whicli must be provided by a constant supply of air to 
 the stove. The oxygen that maintains the combustion takes with it into the 
 fire the nitrogen and other constituents of the air, and these constituents 
 which take no part in the combustion have to be removed with the carbon 
 dioxide gas and water vapour which are the immediate products of the cliemical 
 action. The amounts of heat given in the table are calculated on the sup- 
 position that the inert gases and products of combustion leave the apparatus 
 in which they are burned at the temperature at which they entered it, so 
 that they carry away none of the heat which the combustion has produced. 
 But this supposition cannot be realised in practical Avorking ; some heat is re- 
 quired to keep the air in the exit flue at a sufficiently high temperature to 
 maintain steadily the requisite supply of air to the fire, so that, so far as the 
 heating of the room or building is concerned, some heat must always be lost. 
 With an open fire about nine-tenths of the heat of combustion disappear, 
 being carried away partly by the heated products of combustion, partly by 
 heated air which passes up the chimney without taking part in the combus- 
 tion, and partly by conduction through the walls, as the fire is in general 
 placed against the wall of the room, 
 
 63. To save some of the large margin of 90 per cent, of practically wasted 
 fuel has been the object of very many inventions. We cannot attempt to 
 enumerate them,i i^^^ -^g j^g^y classify them according to the direction in 
 whicli they seek to limit the loss of heat. If we consider the action of an 
 open fire it is evident that there are two ways in which heat passes into the 
 room : (i) by radiation from the heated surfaces ; (ii) by conduction to the 
 sides of the grate, and thence by convection of the air in contact with it. 
 Now with an ordinary grate the larger part of the heat which gets to the 
 air by the second way is immediately carried up the chimney by the rapids 
 of inflow of air to the chimney. It is, indeed, only the heated surface above 
 the stove-opening which helps in any way (except by radiation, which for 
 the parts heated by conduction is very small) to warm the room. The 
 effect of an open fire must therefore be referred to radiation alone. Now 
 the radiation varies very rapidly with the temperature of the radiating 
 surface. The precise law is not accurately known, but is not ill-represented 
 by assuming the quantity of heat radiated to be proportional to the fourth 
 power of the temperature of the radiating surface, measured from 459° below 
 the Fahrenheit zero. The result of this is that lowering the temperature 
 of a surface 15° from 1000° F., or 1*5 per cent., will diminish the radiation 
 by 6 per cent. Or, to give another example, suppose we had a red-hot ball 
 at 1000° F., and brought into contact with it a second cold ball, and imagine 
 that the heat of the 
 one was instantane- 
 ously distributed be- 
 tween the two, so 
 that we had two 
 balls at 500° F. con- 
 taining the same 
 quantity of heat be- 
 tween them as the ^ 
 
 one had originally ; Fip. 43, 
 
 the radiation from 
 
 the huo together would be -| of that from the one ball originally. Thus, if 
 
 ' An abstract of patents for grates &c. compiled by Mr. J. Glaisher is included in the 
 'Beport of the Commission on Warming and Ventilation of DiccUings, 1857. 
 
IM 
 
 HYGIENE 
 
 VI.BMiiaMir.aai. 
 
 without altering the total supply of heat we could so concentrate it that the 
 temperature of the radiating surfaces was raised from 500 to 1000, the 
 heating efi'ect upon the room would be more than doubled. 
 
 (a) The first 
 typical improve- 
 ment in stoves 
 will therefore be 
 the provision for 
 increasing the 
 radiation from 
 the burning fuel. 
 Count Eumford 
 long ago gave 
 rules by which the 
 shape of the stove 
 should be regu- 
 lated, viz. that 
 the covings should 
 beinclinedat 135° 
 to the back of the 
 grate, and the 
 ' register ' door at 
 the mouth of the 
 flue inclined at the 
 same angle. In 
 this way some of 
 the heat radiated 
 from the fuel is 
 reflected into the 
 room and thus saved. The rela- 
 tive dimensions of the grate 
 are given in fig. 43. The 
 material of which the stove is 
 made is also of importance. We 
 have seen that it is advisable in 
 order to promote radiation to limit 
 the conduction, or insulate the 
 heat, as much as possible. Refer- 
 ring to the table on p. 37 it will 
 be seen that the stove should on 
 this account be made of firebrick 
 as far as possible, and the amount 
 of metal reduced to a minimum. 
 This point has not hitherto been 
 much attended to by inventors, 
 but the recent fireplaces of Messrs. 
 Doulton (fig. 44) are constructed 
 entirely of fireclay or pottery with 
 the exception of a bar of iron in 
 the front. Grates are, moreover, 
 frequently made by simply fixing 
 bars in brickwork, the sides of 
 the brickwork being inclined to 
 the back at nearly the angle suggested by Eumford, and their efficiency with 
 a bright fire is very well recognised by common experience. Further im- 
 
 FiG 44. 
 
 Fio 
 
WABMING AND VENTILATION 
 
 125 
 
 provement is secured by making 
 the back of the grate of firebrick 
 sloping forward to the throat of 
 the chimney. 
 
 G4. [h) The second type of im- 
 provement in open grates is that 
 in which part of the heat which 
 passes to the sides of the grate 
 and the flue is brought into the 
 room by surrounding the stove by 
 an air space with two openings 
 which communicate, one with the 
 external air, and the other with 
 the room. With these stoves the 
 air which enters the room to re- 
 place that drawn by the chimney 
 is warmed by the waste heat of 
 the fire, and the communication 
 established with the outside air 
 affords a satisfactory inlet for ven- 
 tilation purposes. Sir D. Galton 
 introduced such ventilating stoves 
 into the soldiers' rooms in bar- 
 racks, and there are many kinds 
 now in the market. The Doulton 
 stove, above mentioned, can be 
 provided with an inlet for air 
 warmed by passing over the 
 heated surfaces round the fire. 
 This delivers the air to the upper 
 part of the room. Boyd's Hygi- 
 astic grate (figs. 45-47) is con- 
 structed on this same principle, 
 but delivers the air through an 
 opening just above the fire under 
 the mantel-shelf. By these de- 
 vices about one-fourth of the waste 
 heat can be utilised. 
 
 It is important that the air 
 which enters by these ventilating 
 stoves should not pass over any 
 iron surface which is heated to a 
 red heat for the reason given 
 above, p. 118. 
 
 65. (c) The third typical modi- 
 fication of open grates refers to the 
 economy of loss of heat by limit- 
 ing the amount of air carried up 
 the chimney without having taken 
 part in the combustion. In order 
 to reduce the loss from this cause 
 attention must be paid to the 
 shape and size of the chimney, 
 for the head will be determined. 
 
126 
 
 HYGIENE 
 
 by the temperature of the air in the chimney, and the quantity of air which 
 traverses it for a given head will depend upon the resistance of the shaft or 
 upon the area of the equivalent orifice. The relation is given in § 17. The 
 loss of heat can be restricted by narrowing the chimney and its orifices, but 
 the removal of a certain quantity of air is desirable for the purpose of ventila- 
 tion, and if the chimney-area is too much restricted, it will not carry away suffi- 
 cient, so that the proper proportions of the chimney and its openings are to be 
 determined with a view to the efliciency of the fire as a ventilating and warming 
 apparatus combined. With this in view ]iIorin ' recommends that the tempera- 
 ture of the air in the chimney should be maintained at about 45° F. above the 
 external air, and the velocity of the smoke issuing from the chimney should 
 be about 10 feet per second, in order to secure stability in the draught, and 
 that the chimney should be capped with a cone-shaped top — the area of the 
 orifice of discharge to be one-half of that of the chimney (see p. 98). The 
 chimney requires narrowing at the throat only if it is wider than necessary ; 
 in that case there is a danger of local circulation in the chimney itself, and 
 consequent smoking, which is prevented by the increased velocity in the 
 narrowed throat. The following table gives the dimensions of the chimney 
 flues necessary for rooms of different sizes according to Morin : — 
 
 Table IX. 
 Relative Size of Cliimney Flues for different Rooms 
 
 Cubic capacity of 
 room in cubic feet 
 
 Volii me of air to be removed 
 
 Area of section of 
 
 Diameter of section of 
 
 by the chimney per hour 
 in cubic feet 
 
 rectangular chimney flue 
 in square feet " 
 
 cyliudl-ical chimney flue 
 in feet - 
 
 3,500 
 
 17,500 
 
 •99 
 
 •88 
 
 4,200 
 
 21,000 
 
 1^19 
 
 •98 
 
 5,300 
 
 26,500 
 
 1-48 
 
 1^08 
 
 6,350 
 
 31,750 
 
 1-78 
 
 1^21 
 
 7,750 
 
 38,750 
 
 2^17 
 
 1-31 
 
 9,200 
 
 46,000 
 
 2-57 
 
 1-44 
 
 10,600 
 
 53,000 
 
 2-97 
 
 1-54 
 
 When ventilating grates are used General Morin recommends the fol- 
 lowing proportions, ' Manuel,' p. 58. 
 
 Table X. 
 Tahle of Dimensions for Ventilating Grates (Morin) 
 
 Cubic capacity of room 
 in cubic feet 
 
 Vohime of air to be 1 Area of section of 
 supphed per hour in cubic 1 smoke flue in square 
 feet 1 feef-' 
 
 Area of section of flue for 
 
 the passage of fresh air in 
 
 square feet 
 
 3,500 
 4,200 
 6,300 
 6,350 
 7,750 
 9,200 
 10,600 
 
 17,500 
 21,000 
 26,500 
 31,750 
 38,750 
 46,000 
 53,000 
 
 •54 
 •66 
 •81 
 •97 
 
 1-2 
 
 1-4 
 
 1-6 
 
 1-5 
 1-8 
 2^3 
 2-7 
 3-3 
 3-9 
 4-6 
 
 Close Stoves 
 
 66. If the fire is not required to assist materially in ventilation as well as 
 in warming, very great economy can be secured in the consumption of fuel by 
 inclosing the fire in a chamber so that the heat may be communicated to the 
 walls of the chamber, and thence by conduction and convection to the air of 
 
 ManiLel de Chauff. 
 
 With a chimney-pot of half the area of the shaft. 
 
WABMING AND VENTILATION 
 
 127 
 
 the room to be heated. The air supplied to the fire is Hmitod to that taking 
 part in the combustion by closing the front of the stove, except that part 
 which actually holds the fire, so that any air which passes in may be com- 
 pelled to pass over the fuel ; the stove stands out in the room and the pro- 
 ducts of combustion are led away to a flue by a narrow chimney of any required 
 length. Such stoves are made of wrought iron, cast iron, or earthenware, 
 and nearly all the heat which is produced by the combustion is used in 
 warming the air surrounding the stove. The rapid distribution of heat is 
 assisted in Sylvester's stove, which is of iron, by attaching to it a number of 
 parallel iron plates. 
 
 Close stoves are sometimes surrounded with an outer envelope of iron or 
 earthenware, and the heat of the stove is then used to warm the air in the 
 space between the two chambers, and the air so heated is distributed as 
 required. The arrangement is then known as a cockle stove. Large stoves 
 on this plan are often used on the Continent for distributing warm air, and 
 are known as caloriferes. The air is in many cases merely taken from the 
 chamber in which the stove is placed, and is liable to be very impure, but a 
 connexion may be made directly with the external air, in which case fresh 
 
 Table XI. 
 
 Name of apparatus 
 
 Duty 
 
 Eemarks I 
 
 Ordinary grates . 
 
 0-10 to 0-12 
 
 Eemove air but do not provide for the j 
 introduction of fresh air. Warming 
 healthy. 
 
 Ventilating grates . 
 
 0-33 to 0-35 
 
 Eemove air and introduce fresh air 
 moderately warmed. Warming 
 
 Stoves : 
 
 
 healthy. 
 
 Earthenware for wood stove 
 
 •87 
 
 \ 
 
 Gurney : 
 
 
 Cast iron with i coal 
 flanges . ^eoke 
 
 •90 
 
 
 •85 
 
 
 Wrought iron{^^^f^ ; 
 
 •90 
 
 •87 
 
 
 Cast iron, with downward 
 
 
 y Do not remove enough air for healthy 
 warming. 
 
 draught — c ,ke 
 
 •94 
 
 E6n6 Duvoir : 
 
 
 
 Cast iron— coal 
 
 ■86 
 
 
 Compagnie d'Eclairage au 
 
 
 
 gaz, without ventilation . 
 
 •96 
 
 
 Fireclay .... 
 Mean 
 
 •93 
 
 / 
 
 •89 
 
 Cast iron — Compagnie 
 
 
 
 d'Eclairage au gaz, with 
 
 
 
 ventilation 
 
 •85 
 
 Eeplace enough air for four or five 
 
 Caloriferes, with fhori- 
 circulation flues - zontal . 
 for smoke . [, vertical 
 
 
 persons. 
 Carmot produce directly sufficient re- 
 
 •63 
 
 moval of vitiated air, and supply 
 
 •80 
 
 generally air too much heated, but 
 
 
 
 could easily be modified to give air 
 
 
 
 at 90°-120° F. Warming unhealthy 
 
 .With nume- 
 
 
 when not combined with ventila- 
 
 
 rous coils of 
 
 
 tion. 
 
 
 large area 
 
 
 
 
 compared with 
 
 
 
 Hot - water J the boiler 
 
 •65 to -75 
 
 \ 
 
 apparatus S When all the 
 
 
 
 i pipes &c. are 
 
 
 Suitable for establishing a regular 
 
 1 contained in 
 
 
 system of ventilation. 
 
 ! the rooms to 
 
 
 
 * be heated 
 
 •85 to ^95 
 
 ' 
 
128 HYGIENE 
 
 air is supplied ; but if the stoves are of iron the air is very frequently ' burnt ' 
 by passing over the red-hot iron surfaces, and the supply of fresh air by a 
 stove of this form is therefore not satisfactory. 
 
 Moreover, according to Hood,' some of the close stoves are liable to 
 develop explosive mixtures of gases and thereby originate fires. Fires have 
 also arisen from the overheating of the flues, so that close stoves require to 
 be worked with very great caution. 
 
 Table XI. of the preceding page gives a collective view of the efficiency 
 or duty of the different kinds of stove investigated by General Morin and 
 is taken froni his ' Manuel,' p. 169. The numbers in the second column 
 indicate the fraction of the total heat of combustion that is applied to 
 warming. 
 
 Gas Fiees and Gas Stoves 
 
 67. For general convenience there can be no question that the most suit- 
 able fuel is coal-gas. It can be ignited at any moment, the amount of heat 
 pioduced can be adjusted to the amount required, it produces no dusty 
 ashes, and can be very easily accommodated in any position. These ad- 
 vantages are enormous and will no doubt be more appreciated as the con- 
 struction of gas fires is improved. Against them have to be set the dis- 
 advantages of the high cost of the heat derived from gas — about eight times 
 that of the same quantity from coal — and the want of a cheerful appearance. 
 Its efficiency as a ventilating extract flue is the same as that of a coal fire 
 producing the same amount of heat. The cost of gas compared with that 
 of coal is probably not yet at its lowest level, and may be expected to be 
 lower when the producers feel the competition of the electric light. The 
 objection to gas fires on the score of appearance can probably be con- 
 siderably reduced by improvement in the designs of the apparatus. And 
 from the circumstance that the appearance of a coal fire is due to red- 
 hot surfaces and the flames of crude coal gas it seems that, with a com- 
 bustible that will supply any required amount of heat and any required 
 amount of light, some arrangement will be possible that is satisfactory, 
 unless it be the very capriciousness of a coal fire that constitutes its main 
 attraction. 
 
 In many gas stoves the necessity for keeping the radiation at a maximum 
 by having only highly heated surfaces exposed to the room is not sufficiently 
 recognised. They consist of a large mass of asbestos nodules heated through- 
 out by the gas, giving a large body of heated matter with its exterior surface, 
 from which the radiation mainly proceeds, comparatively cool. In such a 
 case a larger fraction of the heat goes up the chimney than with a coal fire 
 in good condition, and the contact of thick iron bars of an ordinary grate 
 with the heated asbestos helps to depress the efficiency for radiation for the 
 reason pointed out above (§ 63.) Gas fires should therefore be arranged 
 so as to concentrate the heat upon as small a surface as possible, thus 
 raising the temperature of the surface to the highest possible point. Some 
 of the more recent gas stoves embody this principle, as the flame plays upon 
 shreds of asbestos projecting from a fireclay back. Wright's stove is an 
 example of this. It is arranged so that the heated products of combustion 
 also pass over a series of tubes communicating with the outside air, and thus 
 provides for a supply of warmed fresh air. The same arrangement is also 
 provided in some of Fletcher's recent stoves, one of which is represented in 
 fig. 48. George's Calorigen is another example. 
 
 ' On Warming Bidldings by Hot Watej- &c. p. 306. 
 
WABMING AND VENTILATION 
 
 129 
 
 'With gas stoves as with coal stoves economy of heat is secured by arranging 
 the apparatus so that it stands out in the room, and still further by limiting 
 the size of the chimney flue and combustion area ; but this economy is at the 
 sacrifice of efficiency as a ventilating apparatus. 
 As a general rule all gas stoves should be provided 
 with an outlet flue for the escape of the products 
 of combustion, which include, besides water vapour, 
 carbon dioxide gas and a certain amount of sul- 
 phur dioxide gas due to the combustion of the 
 carbon bisulphide which occurs as an impurity 
 in coal gas. Of these products of combustion the 
 last two seriously vitiate the air of the room, and 
 the sulphur dioxide renders the air not only un- 
 healthy, but perceptibly unpleasant by the sulphur- 
 ous taste. The effect upon plants is very marked 
 and very destructive, and traces of it can readily 
 be found in leather bookbindings, which are 
 rapidly destroyed, and brass work, which is rapidly 
 blackened. Stoves have therefore been designed by 
 which the most deleterious product is absorbed by 
 water, or by the iron or zinc lining of tubes through 
 which the products of combustion are led. The 
 temperature of the burned gases is very much 
 reduced by the same arrangement, so that a large 
 part of the water vapour is condensed. Such 
 stoves are therefore used for warming rooms with 
 
 out being provided with an exit flue, and the whole of the heat produced is 
 retained in the room. It must, however, be borne in mind that the carbon 
 dioxide produced by the combustion is not removed, so that the room should 
 be well ventilated, otherwise it rapidly becomes unwholesome. In fact, such 
 stoves are really only suitable for warming passages, lobbies, and other places 
 where there is a considerable casual renewal of air, and persons do not remain 
 for any length of time. 
 
 Some years ago Sir W. Siemens described in ' Nature ' an arrangement for 
 using coke ignited by gas in an ordinary grate in an exceptionally economical 
 manner. Such a plan, which is intermediate between a coal fire and a gas 
 fire, has considerable advantages. 
 
 Atmospheric Burners 
 
 68. The gas which is burned in stoves is now usually supphed through what 
 we know as atmospheric burners, which may be either horizontal or vertical, 
 the principle of which, the same as that of the ordinary Bunsen burner of 
 the laboratory, is exhibited in fig. 49. The gas passes from the supply pipe 
 
 i'lG. 48 
 
 C 
 
 A 
 
 Fig. 49. 
 
 through a nozzle into a small chamber provided mth perforations a, a, 
 behind the nozzle, through which air passes ; the air and gas mix in the 
 comparatively wide tube A, from which the jets of gas pass by orifices o, 
 
 VOL. I. K 
 
130 HYGIENE 
 
 and are there ignited. If the supply of air is sufficient a flame which ia 
 iion-luminous, or shows faintly blue, is produced ; it gives rise to no smoke, 
 and is much hotter than the ordinary illuminating flame of a gas jet in con- 
 sequence of the more complete combustion of the gas, but it is liable to one 
 serious drawback. If the supply of gas be too small the tube A becomes 
 filled with an inflammable mixture of gas and air, which ignites, and the gas 
 burns thenceforward at the nozzle n, producing an intolerable and easily re- 
 cognised odour of half-burned gas, due to the hydi-ocarbons produced by the 
 incomplete combustion. The gas will still burn at the orifice o, but with a 
 languid, feebly luminous, and smoky flame, instead of the brisk blue non- 
 luminous flame of the Bunsen burner in good condition. This ' burning 
 down ' always occurs if the gas supply is turned too low down, so that gas 
 flreswith atmospheric burners cannot be turned down to an unlimited extent. 
 A reduction of the heat is generally better provided for by limiting the 
 number of jets rather than the volume of any one jet. The ' burning down ' 
 iilso occurs if the pressure of the gas supply is too small or if the orifices be too 
 large ; the instability which accompanies this case is easily recognised by the 
 roaring of the jets and the very marked cone of blue luminosity in the in- 
 terior of the jet close to the orifice. When the flame is thus unstable the 
 burning down occurs when the gas is exposed to a sudden draught. Any 
 noticeable smell of half-burned gas from a gas fire should at once be met by 
 an examination of the state of the jet. In order to set it right if it be burn- 
 ing at the nozzle the gas must be turned off completely and re-ignited at the 
 proper opening. 
 
 Atmospheric burners are now made with devices for preventing the 
 * lighting-back.' One of the devices is to cover the openings at wlaich the 
 gas burns with wire gauze. 
 
 69. The volume of air drawn out of a room by a chimney is, according to 
 Morin, 3200 to 4000 cubic feet per pound of coal burned with a chimney of 
 average height (50 to 55 feet), and the volume required for combustion is IGO 
 to 200 cubic feet. If gas is used for ventilation the relation between the 
 amount of gas burned and the volume of air removed is given in the following 
 table, taken from Morin, p. 198 : — 
 
 Table XII. 
 Volume of gas Volume of air 
 
 consumed per hour passing up the flue 
 
 in cubic feet per cubic foot of gas biu'iied 
 
 71 1900 cu. ft. 
 
 14-1 1400 „ 
 
 28-2 700 „ 
 
 35-3 600 „ 
 
 42-3 500 „ 
 
 49-3 450 „ 
 
 The gas was burned in a chimney about a foot wide. The table shows 
 that the distribution of heat over a wide area is more effective for ventilation, 
 and hence, for example, it would be better to double the area of section of a 
 ■chimney and have two separate gas jets, than to combine the two jets into 
 one, and so double the consumption of gas in the same chimney. 
 
 70. When it is proposed to warm a building by means of hot air provision 
 must be made for maintaining a sufiicient flow. The heated air naturally 
 rises and may itself maintain the flow, if the room to be warmed be above the 
 hot-water pipes or hot-air stove, and be provided with extract flues into which 
 the warmed air ultimately passes. The supply of warm air can be more 
 easily controlled if the extract flues are furnished with an independent supply 
 
WABMING AND VENTILATION 131 
 
 of heat, as by means of gas jets burning in them, or by using as extract flues 
 the chimneys of open fireplaces with small fires not themselves sufficient for 
 the satisfactory heating of the room. In such cases the total supply of air to 
 the room is governed by the draught of the extract flues, and warmed air, or 
 cold, can be supplied by suitable arrangements as occasion may require. If 
 we take the case of an ordinary house we may regard each fire as requiring 
 about 15,000 cubic feet per hour, usually supplied through casual oriiices 
 direct from the outside air, but, if a special fresh air inlet be furnished, ter- 
 minating in a case of water pipes in the hall, the air supply to the fires will 
 be drawn in great part from this inlet, and the whole house will in this way 
 be continuously supplied with moderately warmed air. It need not be sup- 
 posed that the heat thus communicated to the entering air passes directly 
 into the rooms where the fires are ; on the contrary, the heated air causes a 
 very vigorous local circulation up and down stairs and makes an extensive 
 tour of the house before reaching the chimney by which it escapes again to 
 the outside. I have found a fresh-air inlet such as here described delivering 
 22,000 cubic feet of air per hour into a house to feed fires in three rooms. 
 It need scarcely be remarked that in warming by hot air the object aimed at 
 should be to supply a large quantity of moderately warmed air and not a 
 small quantity at a comparatively high temperature. Some systems of hot- 
 air warming are very defective from this point of view. Instead of providing 
 •active extract shafts, the air may be driven over the heating coils by means 
 of a fan if satisfactory arrangements can be made for driving it. 
 
 On the Distribution of Heat 
 
 71. "We have been considering in the preceding paragraphs the various 
 ways of producing heat and the economy of production ; the next question 
 to be considered is the method of carrying the heat from one central furnace 
 to rooms more or less distant from the furnace. The different plans which 
 have been tried may be enumerated as distribution by circulation of hot air, 
 ^ater at low pressure, water at high pressure, and steam, respectively. 
 
 Distribution by Hot Air 
 
 72. This system is frequently employed with caloriferes or cockle stoves. 
 Tubes are carried from the air chamber surrounding the furnace ; the 
 ■circulation is maintained by the head, due to the difference between the tem- 
 perature of the air in the delivery flues and tbat of the air as it enters the 
 supply inlet of the stove. It follows that the furnace must be at the bottom of 
 the system for the supply of hot air. The laws which govern the circulation 
 •of air in the flues have been given (§§ 14-21). The amount of heat which a 
 given quantity of air carries is very small, so that it must be raised to a very 
 high temperature if any considerable distance has to be traversed, and the 
 loss in transit is very large ; it is therefore only a suitable method for local dis- 
 tribution.^ The heat for a large hall or series of rooms, for example, should be 
 carried by water to a battery of hot-water pipes in a hot-air chamber near the 
 rooms, and the distribution of the heat from the battery of pipes effected by air 
 passing from the hot-air chamber through comparatively short channels to 
 the inlets of the rooms. Care must be exercised in forming the channels to 
 be used for hot air, as they are liable to warp and crack in consequence of 
 the drying effect. 
 
 » See p. 117. 
 
 k2 
 
132 
 
 HYGIENE 
 
 Distribution by Water at Low Pressiire 
 
 73. This method is one which is very frequently employed for distributing^ 
 heat in large buildings. The distribution is effected by the circulation of 
 water in metal pipes — generally cast iron — one part of the circulation system 
 being a boiler which is kept at a high temperature by a furnace. Represent- 
 ing the circulation diagrammatically (fig. 50), we may regard it as consisting of 
 two vertical tubes HB, H'L connected at the top by a horizontal tube HH'. 
 The bottom end, L, of the vertical tube H'L is connected with the bottom 
 of a boiler at L', and from the top of the boiler a tube, BH, passes. At the 
 highest point of the circulation is an air- vent, A, open to the atmosphere, so 
 that the pressure at any point of the circulation exceeds the atmospheric 
 pressure only by the pressure due to a column of water whose height i& 
 equal to the vertical distance between the point A and the point at which 
 the pressure is required. Thus the pressure in the boiler will increase 
 by '43 lb. per square inch for every foot of vertical height of the circulation 
 
 ^r 
 
 Q' 
 
 Fig. 50. 
 
 above the boiler. If we take the extreme case of a cu-culation 100 feet high 
 the pressure in the boiler will exceed the atmospheric pressure by 43 lb. per 
 square inch. Now the temperature of water cannot exceed a certain point, 
 depending on the pressure, without producing steam ; the temperature for a 
 pressure of 43 lb. in excess of the atmospheric pressure is 290° F., or only 
 78° above the ordinary boihng-point. If the temperature in the boiler 
 exceeded this, when it was supplying a circulation 100 feet high, steam would 
 be formed, which would pass up the vertical pipe and condense with con- 
 siderable noise and tumult in the cooler water until it had heated the whole 
 upper part of the circulation sufficiently for it to escape as steam at A. 
 This formation of steam in hot-water pipes is not allowable, so that the 
 furnace must not be stoked so as to heat the water in the boiler to that 
 temperature. And hence the highest temperatures possible in a circulation 
 open to the air at one point, is 212° at the top, and increasing (not, 
 however, proportionately to the depth) until at a depth of 100 feet below the 
 
WABMING AND VENTILATION 133 
 
 top it may possibly reach 290° F. As 100 feet would be a very exceptional 
 height, we may say that the temperature of water in low-pressure circulation 
 will not generally exceed 212°. This is the characteristic which distinguishes 
 it from the high-pressure water system. 
 
 It is essential that the circuit of water should be complete ; an accumula- 
 tion of air in the pipe entirely stops the flow, so that a vent for air must bo 
 provided at the top, and wherever air would naturally be imprisoned when the 
 pipes are filled with water from the top. Water, on being heated, disengages 
 a very large quantity of dissolved air, so that these air- vents will always be 
 required to be open from time to time when the pipes have been filled with 
 fresh water after being emptied. It is moreover necessary to provide for the 
 •expansion of the water, so that it is usual to place at the top of the system of 
 pipes a small cistern, C, into which the water driven out by the expansion 
 -can pass without causing an overflow ; and the same cistern may be employed 
 to fill the pipes and automatically replace the water lost by leakage if it 
 be provided with a water supply and ball-tap. Of the two pipes connected 
 with the boiler, BH is called the flow-pipe and LL' the return-pipe. 
 
 74. The calculation of the flow of water in the circulation is very similar 
 to that of air already considered. The head is due to difference of density of 
 hot and cold water, and may be calculated as follows. Consider the two portions 
 of the two vertical tubes contained between two horizontal planes, Ac, h'c', 
 •one foot apart ; let p be the density of water between h and hJ, p' that be- 
 tween c and c' ; the pressure due to the height hh' is {hh')p lb. weight per 
 square foot, and that due to cc' is (cc')p' lb. weight per square foot, and the 
 difference of pressure for that foot of the vertical height of the circulation is 
 
 {ccy - {hh')p, 
 
 and the work done by the difference of pressure for the passage of V cubic 
 ■feet 
 
 ■ Y{icc')p'-{hh')p}. 
 
 The head is therefore { [cc') p' — (hh') p }po, where pq is the standard density 
 at the freezing-point. But p' = po (1 — «^') and p= p^ (1 — at), where a is 
 the coefficient of expansion of water.^ Hence the head for one foot = a{t — t') 
 (since cd and hh' are each equal to one foot), or the head per foot per unit differ- 
 •ence of temperature is equal to a. 
 
 Hence, to find the head for any circulation, we may divide the circulation 
 into foot sections by parallel horizontal planes one foot apart. Measure the 
 temperature at each section of the flow and return-pipes, and the head of 
 the whole circulation is the sum of the differences of temperature of cor- 
 responding sections multiplied by the coefficient of expansion of water. If 
 the total sum of the differences of temperature comes out negative it shows 
 that the circulation is in the opposite direction. 
 
 The temperature at different points of the circulation may be approximately 
 determined by placing a thermometer on the pipe and wrapping it round 
 with a good thickness of cloth or felt. 
 
 1 For the sake of simplicity -we have assumed that the coeflficient of expansion of 
 water is the same at all temperatures. This is not really the case. In fact, -water 
 contracts slightly when it is heated for the range of temperature between 32° P. and 
 .39° F., and on further heating it expands, at first very slightly and then to a gradually 
 increasing extent, until the expansion of a cubic foot for the ten degrees below the boiling- 
 point is -0042 cu. ft. The temperatures in the flow and return pipes of a hot-water 
 circulation will not be far outside the limits of 92° F. and 212° F., and the mean coefficient 
 of expansion for this range is -000318, which may be taken as the numerical value of o in 
 'the expressions in the text. 
 
134 
 
 HYGIENE 
 
 The head depends upon the vertical height, so that an incHned pipe with 
 a gentle slope or a coil of horizontal pipes is only e£fective to the extent of 
 its vertical height. 
 
 If the horizontal planes cut the pipes in more than two points, as in 
 fig. 51, at A,, 7io, h^, h^, the head may be calculated as before, separately for 
 the two portions A, and ho, and /13 and /14 respectively, so that the head due 
 to the section represented will be, if ti, t.y, t-^, t^ be the corresponding 
 
 temperatures, 
 
 {t\ — ^2 + *3 — ^.i) «. 
 
 A, I, h, from which it will be seen that the 
 
 introduction of a depression such as 
 that represented in the figure re- 
 duces the head by the sum of the 
 products (^2 — ^3) « for each vertical 
 foot of height of the depression 
 introduced. 
 
 The calculation of the head in 
 this manner will make it easy to 
 see from a diagram of the proposed 
 position of water-pipes whether 
 there will be a flow, and in what 
 direction, and will suggest the most 
 jijQ 51 advantageous way of arranging the 
 
 pipes so as to produce the maximmn 
 head. Thus, in carrying a circulation below the boiler, as shown in fig. 52, 
 it will be seen that the head due to the part of the circuit above the hori- 
 zontal line, lih', is opposed by that due to the rest of the circuit, so that if 
 the fall of temperature were simply proportional to the length of the pipe 
 traversed the circulation in the circuit represented would be reversed. But 
 if it be arranged so that there is a considerable loss of heat from HH' and 
 
 consequent fall of temperature 
 '"* between H and H', and if the 
 heat required be taken from 
 coils on the part of the circu- 
 lation represented by HL, and 
 as little as possible from the 
 part leading from L back to 
 the boiler (indeed, Uie pipes 
 may be so arranged that part 
 of the heat lost from h'Jj 
 warms L'A, by passing L7i 
 through the heating coil on 
 H'L), the circulation may be 
 established, though carrying 
 Fig. 52. pipes below the boiler is not 
 
 always a successful arrange- 
 ment ; -and in order to secure a flow it may be necessary to waste a good deal 
 of the heat in cooling the part represented by HH'. 
 
 Wherever there is a head, great or small, there will be a flow of some 
 sort, provided there is a continuous channel filled with water from the 
 boiler, and back again. The magnitude of the flow as measured, say, in 
 cubic feet of water per minute depends, just as in the case of air, not only 
 upon the head, but upon the resistance of the complete chamiel. The 
 
WABMING AND VENTILATION 135> 
 
 resistance could be calculated by laws similar to those we have explained 
 for air, but the calculation for any hot-water system would be exceedingly 
 elaborate and complicated, so that hot-water engineers work empirically^ 
 from established successes to any new arrangement required. 
 
 75. Difficulties sometimes arise when a number of circulations have 
 to be maintained by the same boiler, for if the circulations supply pipes on 
 different levels the head for each circulation will be different, and the object 
 desired is that the flow shall be the same for each ; but this can be adjusted 
 by means of a valve upon each separate circulation by which the circulation 
 with a greater head can be ' throttled ' — that is, have its resistance artificially 
 increased. The plan is, however, not without its disadvantages, for it of 
 course implies reducing all the flows to that in the circulation with the 
 worst head. It is therefore desirable, if it be seen that the head for any 
 circulation will be small, to make its resistance comparatively small also, so^ 
 that the other circulations need not be throttled. 
 
 High-Pressure Water System 
 
 76. We have seen that if one part of a circulation have free access to the 
 air the temperature of the water cannot rise much beyond the boiling-point 
 at ordinary pressure, viz. 212° F. But if the water be completely inclosed the 
 temperature can be raised to a very much higher figure, and the pressure 
 exerted upon the pipes is more than proportionately high. Thus the pressure 
 of steam, or the pressure required to prevent steam forming at 212° F., is 
 14| lb. per square inch, at 300° F. it is 67 lb. per square inch, and at 400° F, 
 250 lb. per square inch. 
 
 A system of heating by water pipes has been designed and worked by 
 Messrs. Perkins in which the pipes are of wrought iron and sufficiently 
 strong (internal diameter f inch, external IfV inch) to withstand the pressure 
 corresponding to very high temperatures. 
 
 A sufficient length of these narrow iron pipes connected by an ingenious 
 device is formed into a complete circuit ; part of the circuit is coiled into a 
 hollow coil and exposed to the heat of a furnace. At the top of the circu- 
 lation is a series of tubes of larger diameter, called expansion tubes, half 
 filled only with the water, the other half with air, and therefore allowing for 
 the expansion of the water. ' When the pipes have been filled with water the 
 openings at the top are closed by screw plugs, so that the whole system forms 
 a closed vessel with a small quantity of air at the top, which does not, 
 however, extend so far as to impede the circulation of the water. The water 
 circulates with very great rapidity in spite of the narrowness of the bore, and 
 when the apparatus is in full working the temperature of the pipes reaches, as 
 a rule, 300° F. 
 
 The temperature is regulated by fixing the proportion of length of pipe in 
 the furnace to the length outside ; it is usually one-tenth. If the space to 
 be warmed is too large to be heated properly by a single flow and return, 
 the pipe is carried back to the furnace and a second coil made, and then the 
 pipe proceeds again to another part of the building and returns to be con- 
 nected with the end of the first circulation. This may be repeated several 
 times, so that the pipe may start from the furnace and return to it again, 
 start again, and come back, four or five times before the circuit is complete. 
 In general, a circulation with one coil only in the furnace consists of 1500 
 feet, 150 feet being exposed to the fire ; if a second 1500 feet are required the 
 circuit includes another 150 feet in the fire, and so on. Thus the same water 
 passes through the whole length of pipe, however great it may be, but, 
 generally, not more than 7500 feet are heated by a single furnace. 
 
136 HYGIENE 
 
 The water in the pipes wastes to a certain extent, although the whole is 
 closed lip, so that the plugs at the top are periodically taken out and a httle 
 water added. 
 
 The high temperatiire of the pipes, though useful and desirable from the 
 fact that the distribution of heat takes place to a greater extent by radiation 
 than is the case with low-pressure systems, requires that the system should 
 be introduced with proper precautions. The insurance companies require 
 the pipes to be at least one inch from the woodwork, and this is no doubt 
 generally desirable and should be provided for. Should a pipe for any reason 
 become stopped, the pressure reaches an uncontrollable magnitude, but the 
 weakest part is that in the fire, so that it bursts there, and the fissure is said 
 to be so small that the water issues as a jet of steam without douig any 
 serious damage. 
 
 Distribution of Heat by Steam Pipes 
 
 77. There are many plans for keeping a series of pipes hot by the circula- 
 tion of steam, and they differ in the form of the pipes and the pressure of the 
 steam employed. If the system is well arranged the heat is developed by 
 the condensation of the steam, and no steam leaves the pipes but only the 
 condensed water, which may be returned to the boiler by suitable apparatus. 
 The condensation of the steam causes a rattling noise in the pipes which is 
 sometimes disagreeable. The pressure of steam in the pipes is in any case 
 limited by the safety-valves of the boiler, but when low-pressure steam is 
 reqmred from a high-pressure boiler a reducing valve may be introduced. 
 For further information the reader may be referred to a paper ' On the 
 American Practice of Warming Buildings by Steam,' by the late Eobert 
 Briggs ( ' Proc. Inst. C.E.' vol. Ixxi. 1882-3, p. 95, with the discussion 
 thereupon). 
 
 Amount of Heating Sueface Eequered for Waeming Buildings 
 
 78. The calculation of the amount of hot-water piping of given external 
 diameter that may be necessary for the adequate warming of a building 
 depends upon a large number of elements. Provision must be made for the 
 loss of heat by conduction through the walls and windows, as well as for 
 that carried away by the air in the process of ventilation. Both these are 
 variable quantities depending upon the state of the weather ; moreover, in 
 calculating the former, the nature and thickness of the walls and the area of 
 window surface must be known, and for the latter more heat will be required, 
 if for any reason the ventilation flow is more active, and less if the ventilation 
 is restricted. AVe have not space to indicate the details of the calculation in 
 special cases. An additional disturbance of the calculation is introduced if a 
 room is occupied by a large number of persons or if artificial light is employed. 
 It must be assumed that the amount of heat available shall be sufficient to 
 raise the temperatm^e to the highest point required in the coldest weather 
 likely to be experienced, and with the fullest ventilation which the cir- 
 cumstances require. The supply can then be restricted by a valve on the 
 apparatus if the conditions are such that a reduction of temperature is 
 desirable. 
 
 In order to enable the reader to determine approximately the length of 
 low-pressure water pipe required, we give a table from Hood's ' Warming of 
 Buildings,' p. 119, showing the length of 4-inch pipe at 200° F. necessary 
 to warm given quantities of air. If the diameter of pipe is increased in any 
 ratio the length required will be reduced in the same ratio. Thus 200 feet 
 
 of 4-inch pipe can be replaced by - x 200 feet of 3-inch pipe and so on. 
 
 o 
 
WABMING AND VENTILATION 
 
 137 
 
 ' The quantity of air to be warmed per minute in habitable rooms and n 
 pubHc buildings must be from three and a half to five cubic feet for each 
 person the room contains, and one and a quarter cubic foot for each square 
 foot of glass.' 
 
 If the high-pressure system is employed, the necessary area of surface is 
 very much reduced inconsequence of the higher temperature which is reached. 
 
 Table XIII 
 
 ■SJioioing the Length in Feet of Pipe, 4 Inches in Diameter, which will heat 1000 Cubic 
 Feet of Air per Minute any required number of Degrees, the Temperature of the 
 Pipe being 200° Fahr. (Hood.) 
 
 Temperature of 
 
 
 Temperature at which the room is re 
 
 quired to be kept 
 
 
 
 external air, 
 
 Fahrenheit's 
 
 scale 
 
 
 
 
 
 
 
 
 
 
 
 45° 
 
 50° 
 
 55° 
 
 60° 
 
 65° 
 
 70° 
 
 75° 
 
 80° 
 
 85° 
 
 90° 
 
 10° 
 
 126 
 
 150 
 
 174 
 
 200 
 
 229 
 
 259 
 
 292 
 
 328 
 
 367 
 
 409 
 
 12° 
 
 119 
 
 142 
 
 166 
 
 192 
 
 220 
 
 251 
 
 283 
 
 318 
 
 357 
 
 399 
 
 14° 
 
 112 
 
 135 
 
 159 
 
 184 
 
 212 
 
 242 
 
 274 
 
 309 
 
 347 
 
 388 
 
 16° 
 
 105 
 
 127 
 
 151 
 
 176 
 
 204 
 
 233 
 
 265 
 
 300 
 
 337 
 
 378 
 
 18° 
 
 98 
 
 120 
 
 143 
 
 168 
 
 195 
 
 225 
 
 256 
 
 290 
 
 328 
 
 368 
 
 20° 
 
 91 
 
 112 
 
 135 
 
 160 
 
 187 
 
 216 
 
 247 
 
 281 
 
 318 
 
 358 
 
 22° 
 
 83 
 
 105 
 
 128 
 
 152 
 
 179 
 
 207 
 
 238 
 
 271 
 
 308 
 
 347 
 
 24° 
 
 76 
 
 97 
 
 120 
 
 144 
 
 170 
 
 199 
 
 229 
 
 262 
 
 298 
 
 337 
 
 26° 
 
 69 
 
 90 
 
 112 
 
 136 
 
 162 
 
 190 
 
 220 
 
 253 
 
 288 
 
 327 
 
 28° 
 
 61 
 
 82 
 
 104 
 
 128 
 
 154 
 
 181 
 
 211 
 
 243 
 
 279 
 
 317 
 
 30° 
 
 54 
 
 75 
 
 97 
 
 120 
 
 145 
 
 173 
 
 202 
 
 234 
 
 269 
 
 307 
 
 Freezing) ggo 
 point i 3^o 
 
 47 
 
 67 
 
 89 
 
 112 
 
 137 
 
 164 
 
 193 
 
 225 
 
 259 
 
 296 
 
 40 
 
 60 
 
 81 
 
 104 
 
 129 
 
 155 
 
 184 
 
 215 
 
 249 
 
 286 
 
 36° 
 
 32 
 
 52 
 
 73 
 
 96 
 
 120 
 
 147 
 
 175 
 
 206 
 
 239 
 
 276 
 
 38° 
 
 25 
 
 45 
 
 66 
 
 88 
 
 112 
 
 138 
 
 166 
 
 196 
 
 230 
 
 266 
 
 40° 
 
 18 
 
 37 
 
 58 
 
 80 
 
 104 
 
 129 
 
 157 
 
 187 
 
 220 
 
 255 
 
 42° 
 
 10 
 
 30 
 
 50 
 
 72 
 
 95 
 
 121 
 
 148 
 
 178 
 
 210 
 
 245 
 
 44° 
 
 3 
 
 22 
 
 42 
 
 64 
 
 87 
 
 112 
 
 139 
 
 168 
 
 200 
 
 235 
 
 46° 
 
 
 15 
 
 34 
 
 56 
 
 79 
 
 103 
 
 130 
 
 159 
 
 190 
 
 225 
 
 48° 
 
 
 
 7 
 
 27 
 
 48 
 
 70 
 
 95 
 
 121 
 
 150 
 
 181 
 
 214 
 
 50° 
 
 
 
 
 
 19 
 
 40 
 
 62 
 
 86 
 
 112 
 
 140 
 
 171 
 
 204 
 
 52° 
 
 — 
 
 — 
 
 11 
 
 32 
 
 54 
 
 77 
 
 103 
 
 131 
 
 161 
 
 194 
 
 To ascertain by the above table the length of pipe which will heat 1000 cubic feet of 
 air per minute, find, in the first column, the temperature corresponding to that of the 
 external air, and at the top of one of the other columns find the temperature at which 
 the room is to be maintained ; then, in this latter column, and on the line which 
 corresponds with the external temperature, the required number of feet of pipe will be 
 found. 
 
 We quote also from the same work (§ 111) some empirical rules, giving 
 the length of 4-inch pipe required for rooms of different sizes and character. 
 We have omitted the footnotes which apply to certain special cases. 
 
 ' Churches and large Public Booms 
 *■ To heat these when they have an average number of doors and windows, 
 and only moderate ventilation, divide the cubic measurement of the building 
 by 200, and the quotient will be the number of feet in length of pipe four 
 inches diameter that will be required to produce a temperature of about 55° 
 in very cold weather. This is equivalent to allowing five feet of i-inch 
 pipe for every thousand cubic feet of space which the building contains. If 
 the apparatus is so contrived that the warming of the air is effected before it 
 actually circulates in the room, and that the same portions of air are not 
 returned to be heated a second time, but fresh portions of external air are 
 brought successively in contact with the heating apparatus, it will reqmre 
 from 50 to 70 per cent, more pipe to produce the same effect ; but the air 
 will, of course, be more pure and fresh. 
 
138 HYGIENE 
 
 ' Dwelling-rooms 
 
 * These will generally require about twelve feet of 4-incli pipe to every 
 thousand cubic feet of space contained in them to give a temperature of 
 about G5°" To raise the temperature to 70° will require about fourteen feet 
 of 4-inch pipe. 
 
 'Halls, shojis, tuaiting-roovis, &c. will require about ten feet of 4-incli 
 pipe to every thousand cubic feet of space to raise the temperature to about 
 55°. For a temperature of 60° about twelve feet of 4-inch pipe will be 
 required. 
 
 ' ScJiools and lecture-rooms, i^equiring a temperature of 55° to 58°, will 
 require from six to seven feet of 4-inch pipe to every thousand cubic feet of 
 space. 
 
 ' Drying-rooms, or closets for drying wet linen and other substances,, 
 require from 150 to 200 feet of 4-inch pipe to every thousand cubic feet 
 of space to raise the temperature to 1'20° when empty, or about 80° when 
 the room is filled with wet linen. 
 
 * Drying-rooms for curing bacon, or for drying paper, or leather, or damp 
 hides, will require twenty feet of 4-inch pipe to every thousand cubic feet 
 of space to give a temperature of about 70°. 
 
 ' Greenliouses and conservatories requiring a temperature of about 55° 
 in the coldest weather must have thirty-five feet of 4-inch pipe for each: 
 thousand cubic feet of space they contain.' 
 
 Waeming Apparatus in Eelation to Ventilation 
 
 79. Heat may be used in two ways in a ventilation system : first, to- 
 produce a head in an outlet flue for the extraction of air, and secondly to 
 warm the air of the rooms or that supplied to the inlets. We have sufficiently 
 dealt with the first application of heat. As to the second, we merely wish 
 now to reiaiark upon the effect of the warming apparatus upon the state of 
 the air. We have akeady (§ 5G) pointed out a danger in the case of iron. 
 stoves, and the remarks in Table XI. § 6G indicate the healthiness or other- 
 wise of the systems of warming there referred to. 
 
 The air which is warmed by passing over heating surfaces of any kind is 
 dried in consequence, and this effect, being dependent only upon the extent 
 to which the temperature is raised, is the same whatever system of warming 
 be adopted, and can only be counteracted by furnishing the air with an 
 additional supply of moisture. The hot- water systems and steam-heating 
 systems should not of themselves deteriorate the air which they warm, but 
 the pipes which carry the Avater or steam are generally put in out-of-the- 
 way places, which are very liable to become receptacles for dirt of one sort 
 or another. A considerable accumulation is likely to take place during the 
 summer months when the apparatus is not in use, and when the pipes are 
 heated for the winter the dust becomes subjected to a process of distillation,, 
 and the air is consequently fouled. The pipes should therefore be laid in 
 such a manner that they can be periodically and properly cleaned. The 
 injurious action upon the air depends, other things being equal, upon the 
 temperature, so that the high-pressure system is likely to cause greater 
 annoyance in this respect than the low-pressure pipes ; but if the pipes are 
 properly cleaned there seems no reason to anticipate the fouling of the air by 
 either system. 
 
 What is here said about hot-water pipes apphes to a modified extent to 
 all channels for the supply of fresh air. They are always liable to be fouled,. 
 
WABMING AND VENTILATION 139' 
 
 and require cleaning, and if the openings are covered with gauze or gratings 
 the deposit of dirt tliere may seriously interfere with the supply of air, both 
 as regards its quantity and its quality. 
 
 Aetificial Coolino 
 
 80. A corollary to the general problem of maintaining the air of an in- 
 habited room at the temperature most suitable for its occupants is the con- 
 sideration of the means of reducing the temperature in summer if the weatlier 
 should render such a reduction desirable. In an early section (§ 6) we con- 
 sidered the means of preventing the communication of heat between a room 
 and the external air, but the only special precautions in general use to prevent 
 a too high temperature in summer are to shut the windows and cover them 
 with outside blinds, or louvre shutters, to prevent the direct radiation of the- 
 sun from penetrating to the room, and to whitewash the roofs, in order that 
 the heat of the sun's rays may be dissipated by the diffuse radiation from 
 the white surface. The effect of the first precaution is most easily apparent ; 
 what the effect of the second may be it is difficult to estimate, except in a 
 most general way. 
 
 Another method of keeping a room cool in summer is to supply it with 
 air which passes through an underground channel ; but such a method is not 
 often adopted, and the air is likely to be fouled, even to the extent of having 
 a mouldy smell, unless special precautions are taken to keep the channel dry 
 and clean. 
 
 If the outside air is dry, it can be cooled considerably on its passage inta 
 a room by being made to pass over wet surfaces of linen &c. or by the injec- 
 tion of water spray. The cooling in this case arises from the evaporation of 
 water into the comparatively dry air, and the water so evaporated is carried 
 by the passing air into the room to be cooled. The air is thus nearly 
 saturated by the cooling process, and the moistening may easily be carried 
 further than is generally desirable. But on this point it must be remembered 
 that any cooling of air necessarily causes it to approach the saturation point 
 (see p. 45) unless moisture is abstracted when the cooling is effected. 
 
 81. Of late years there has been a great development of machines for the 
 artificial production of ice or the supply of cold air. Such machines may 
 be arranged in three classes :— 
 
 (1) Machines in ivliicli the cooling is produced by the evaporation of a volatile 
 liquid in one vessel, the vapour formed being absorbed by water or some 
 other liquid in another vessel connected with the first 
 
 Carre's ammonia machine is one of the best known examples of tliis 
 method. A solution of ammonia gas in water is first placed in a vessel, which 
 we may call a boiler, and the boiler is connected with a second vessel, a con- 
 denser. The boiler is first heated to about 250° F. and the condenser 
 meanwhile cooled by immersion in a water tank ; the ammonia is driven 
 off from its solution and the pressure reaches so high a point that the 
 ammonia gas condenses to a liquid in the condenser, giving out a large 
 quantity of heat in so doing to the water of the tank. The apparatus is then 
 removed from the furnace and the tank ; the boiler is next immersed in 
 water, and the condenser is surrounded by the water to be frozen. The 
 cooled water in the boiler reabsorbs the ammonia vapour and reduces the 
 pressure, and thus determines the evaporation of the ammonia liquid and a 
 consequent large reduction of temperature in that liquid and the vessel which 
 
140 HYGIENE 
 
 surrounds it. By repeating the process successive quantities of heat are 
 removed from the vessel surrounding the condensed ammonia. With a 
 large apparatus of this kind, arranged for continuous instead of intermittent 
 cooling, ice is said to be producible at the very low rate of twopence per 
 hundredweight. (Peclet, * Traite de la Chaleur,' tome iii. p. 149.) 
 
 Another of Carre's apparatus in which heat is absorbed by the rapid 
 evaporation of water at low pressure, the vapour being absorbed by sulphuric 
 acid, is also an example of this type of machine. 
 
 (2) Machines in tvhich cold is produced by the expenditure of mechanical 
 work in the evaporation of a liquid 
 
 We have already seen that water evaporates at all temperatures ; the 
 amount of evaporation depends upon the pressure to which the surface is 
 exposed. The same is true of other liquids, and advantage is taken of this 
 in the production of cold or abstraction of heat. The rate of evaporation is 
 very slow if there is any considerable pressure of air on the surface of the 
 liquid, so that the first step in the manipulation of an apparatus of this 
 kind is to pump out the air. If we suppose the air removed, we may con- 
 sider two vessels which are, so to speak, in communication through an air- 
 pump, that is to say, as the pump is worked any air or vapour in the one 
 vessel will be gradually pumped out and dehvered to the other. The result 
 is that if a volatile liquid be contained in each of the vessels the vapour will 
 be pumped from the one vessel to the other, and, in consequence, continuous 
 evaporation will take place in the one vessel and continuous condensation 
 in the other. This imphes a continuous absorption of heat for the forma- 
 tion of vapour in the one vessel and a continuous development of heat 
 by condensation in the other. Thus by keeping the pump working heat 
 passes from the cold evaporating liquid and its surroundings to the 
 hotter condensing liquid and its surromidings. By adding some arrange- 
 ment for the transference of the hquid back to the evaporating vessel the 
 process may go on continuously. Such an apparatus can therefore be used 
 either as a cooling apparatus or as a warming apparatus, whichever may be 
 desired. 
 
 If heating is wanted, the cold vessel should be surrounded with an ample 
 supply of water to keep up its temperature ; if cooling is desired, the heat 
 developed by the condensation may be thrown away by allowing it to pass 
 into the outside air or a tank of water. This is one instance already alluded 
 to of the employment of mechanical work (viz. that required to work the 
 pump) for the purpose of heating or cooling. But an important and inter- 
 esting point in connexion with it is that the heating effect is greater than 
 the mechanical equivalent of the power employed to drive the pump. In 
 fact, neglecting losses, the heat which is given to the condensing vessel is 
 greater than the amount equivalent to the work done in pumping, by the 
 amount drawn from the evaporating vessel. An ideal arrangement, as sug- 
 gested by Sir Wilham Thomson, would be to make use of both the heating 
 and cooling effects of such an arrangement ; suppose, for mstance, that an 
 arrangement of tliis kind were used for warming a house in winter, then it 
 might at the same time be producing ice, which could be stored in a suitable 
 ice-house for use in summer, and we should thus be able, in a sense, to 
 equalise the distribution of summer and winter temperature inside the house 
 by locaHsing the loss of heat in winter, and storing it, so to speak, in the 
 ice. 
 
 But we are not aware that this ideal arrangement for using both ends of 
 a mechanical heating and cooling apparatus has ever been put into practice. 
 
WABMING AND VENTILATION 141 
 
 The one end of it, the cold producer with methylic ether as the evaporating 
 Hquid, has, however, found appKcation on a commercial scale. It is one of 
 the methods used in the cooling of ships employed for the carriage of meat. 
 By the cooling apparatus the meat is kept in a current of dry air very near 
 the freezing-point, and is thus kept fresh during long voyages. An apparatus 
 by MM. E. Pictet et Cie., with sulphurous acid as the evaporating liquid, 
 was used to cool glycerine to such an extent as to freeze the surface of 
 water of an artificial ice skating rink. The price assigned to the production 
 of ice on a large scale by this apparatus is fourpence per hundredweight. 
 
 (3) Machines in which cold is produced by the expansion of air 
 
 The dynamical coohng of air has already been referred to and accounted 
 for. The considerable fall of temperature corresponding to the expansion 
 of air from considerable pressures to the atmospheric pressure shown in the 
 table of page 43 shows that if this expansion could be arranged on a large 
 scale cooling could be effectively carried on. The air must not, however, be 
 allowed simply to blow out through a fine nozzle, for in that case the fall of 
 temperature would be greatly reduced in consequence of friction at the nozzle. 
 It is, in fact, desirable to pass the compressed air through an engine, and let 
 it do some such work as pumping water, or driving a knife machine, a 
 shoe-blacking machine, or an electric-lighting dynamo,^ in order that the 
 greatest effect may be produced. As we have to start with uncompressed 
 air it would be necessary for the installation of a cooling apparatus on this 
 plan to provide for the compression of the air by a second engine ; the com- 
 pression would heat the air, and the heat so generated is a waste product of 
 the cooling apparatus, but might be employed in heating buildings while ice 
 was being produced by the expansion ; and we should thus get an arrange- 
 ment similar to that indicated for the evaporation machines in which the 
 whole plant would consist of a compressing engine, delivering hot compressed 
 air which may be cooled and then passed into an expansion engine, which 
 delivers the air cooled to an extent depending on the difference of its pressure 
 in the compressed and uncompressed states. But the supply of compressed 
 air at ordinary temperatures to houses and workshops is now becoming a 
 commercial matter in some large towns, just as the supply of gas or 
 electricity has become ; and in that case the householder requires only an 
 engine providing for the expansion of the air and performing the useful work 
 indicated above, in order to get ice-cold air, and so produce ice itself if it is 
 wished. A most interesting account of the way in which such a system of 
 distribution of compressed air is employed in Paris (Popp's system) is given 
 by Professor A. B. W. Kennedy in the * British Association Report for 1889/ 
 p. 448, and ' Engmeering,' Sept. 13, 1889. 
 
 COMBINATIONS OF APPAEATUS FOE HOUSES AND 
 LARGE BUILDINGS 
 
 81. It now remains for us to consider the combinations of apparatus that 
 have been employed to provide for the efficient warming and ventilation of 
 large rooms and buildings. The plans which have been adopted in different 
 cases are extremely numerous and varied, and the accounts of the per- 
 formances of the different apparatus are not easily compared. Sometimes 
 
 ' In a paper in La Lumi&re Electrigue, tome xi. 1884, p. 421, Prof. Lippmann calls 
 special attention to the thermal economy of such an arrangement. 
 
142 HYGIENE 
 
 the ventilation depends entirely upon the draft of a large chimney-stack, 
 the different rooms or parts of a large hall heing connected with the stack by 
 separate ducts ; in others the large chimney is replaced by a fan ; and either 
 of these plans may be supplemented by open fires or separate ventilating 
 Hues, or the propulsion or plenum method may be employed as a substitute 
 or an addition to the other forms of apparatus. The published descriptions 
 or statistical information as to the action of the systems in actual use are 
 seldom so arranged as to enable the reader to form a very precise opinion 
 of the merits of the particular j)lan adopted. In warming and ventilation, 
 perhaps more tlian any other subject, success or failure depends upon 
 small details that may be passed over in description, and slight changes that 
 seem at first sight unimportant may entirely change the aspect of the 
 question, particularly when economy is an important element for considera- 
 tion ; for instance, a system which can be applied successfully to a high 
 building of several stories may prove to be a failure when introduced into a 
 building of the same cubic content distributed over a wide area in a single 
 story. 
 
 How unsatisfactory the comparison may be in the question of coat may 
 be gathered from the following extract from the very valuable report of 
 Professor Carnelley upon the cost and efficiency of the heating and ventila- 
 tion of schools.^ He says (p. 45) : ' In Nottingham (open fires) they burn 
 nearly five times as much coal per head as in Dundee, and although coal is 
 not much more than one-half the price, yet it costs them nearly three times 
 as much per head of accommodation. The most extravagant " open fire" 
 school in Dundee only burns one-half as much coal per head as the most 
 careful " open fire " school in Nottingham. One open fire school in Dundee 
 burns only 23 lb. per head, while one of the open fire schools in Leeds burns 
 as much as 2391b. per head! One of the "large hot pipe" schools in 
 Dundee bm-ns only 341b. of coal per head, while one of the "large hot 
 pipe " schools in Nottingham burns 417 lb. per head. Either, then, they are 
 inordinately extravagant in such towns as Leeds, Sheffield, Nottingham, &c. 
 and are roasting the children, or we in Dundee are freezing them for the 
 benefit of the ratepayers. It is to be noted that the same thing occurs, no 
 matter what system of natural heating and ventilation is adopted. The 
 result, therefore, cannot be due to any superior efficiency of our heating 
 arrangements in Dundee.' 
 
 82. The report from which the above extract is quoted is a very complete 
 arrangement of the results of an investigation of the ventilation and warming 
 of 323 schools, of which 150 were personally visited. We give a few of the 
 important conclusions from the summary on pp. 43-48. 
 
 First Cost of System of Warming and Ventilation 
 
 Per heurl of Per school of 
 
 accommodation lOOU pupils 
 
 s. £ 
 
 ( Open fires 4 200 
 
 Natural ventilation < Small hot-water pipes (higti pressure) 8 400 
 
 I Large hot-water pipes (low pressure) . 10 600 
 ,_ , . , ,. rAs applied to schools suitably de- 
 
 iation'' ' \ '^Sned 17 850 
 
 LAs applied to ordinary schools . . 20 1000 
 
 ' Presented to the School Board of Dundee. Published by Winter, Duncan, & Co., 
 Dundee. 
 
WABMING AND VENTILATION 
 
 143 
 
 Total Annual Cost 
 
 - 
 
 Cost per head of 
 accommodatioii 
 
 Cost for 
 
 a school to accommodate 1000 
 children 
 
 Interest on 
 tlrst cost 
 
 Annual 
 cost 
 
 Total 
 annual cost 
 
 Interest on 
 first cost 
 
 Annual cost 
 
 Total 
 annual cost 
 
 Ordinary systems 
 Mechanical system . 
 
 Difference . 
 
 d. 
 
 H 
 
 8 
 
 d. 
 
 '2 
 
 d. 
 
 6 
 
 15| 
 
 £ 
 14 
 34 
 
 £ s. d. 
 11 9 2 
 31 5 
 
 £ s. d. 
 25 9 2 
 65 5 
 
 5 
 
 A3. 
 
 *4 
 
 9^ 
 
 20 
 
 19 15 10 
 
 39 5 10 
 
 Efficiency &c. 
 (a) Badiation v. Conduction.-mth those systems, in which the rooms are heated by 
 TadaionratheJthan by conduction, the air is much more highly charged with micro- 
 orglntms "han with those systems in which the rooms are heated more by conduction 
 
 "^^M^^r Grates v. Ordinary Grates.-Ks regards open fires, 'Manchester 
 .rate ' ^ are much more effective in keeping the air of the rooms pure than ordinary grates. 
 ^ c Meclanical.. Ordinary S.si.^s.-Mechanical ventilation .s undoubted^^^^^^^^ 
 effect ve in maintaining the purity and temperature of the air m schools than any of the 
 ofdtaly methods usually adopted, and is hence more conducive to health and comfort 
 
 i^Gas Engines and Water Engines.-G^s engines are much cheaper and more effective 
 
 -than water engines for driving the fans. ^e • 4. 
 
 Te) PolTo/ Gas Engine reguired.-K two horse-power gas engme is arnply sufficient 
 
 ior drivinga 4 ft. Blackman or Aland fan (even one horse-power would probably be 
 
 sufficient)f while a one horse-power [engine] is sufficient for six of Cunmngham s fans. 
 
 ( f ) Bloiving in v. Expanding the ^ir.-The former is preferable. 
 
 L)i;S!s/a/is.-One large fresh-air inlet shaft is much better than several small 
 ■ones, and the entrance to the shaft should be as free as possible. 
 
 (h) Air FiZiers.— Recommended. (See p. 51.) . .^ -di i ^„„ 
 
 (i) Blackman's v. Cimninqham^s Fans.-\Nhen properly arranged, a 4 "• Blackman 
 fan appears to be more effective and costs less both in fuel and in annual cost than the 
 te or sS Cunningham's fans usually employed to do the same work. Cunmngharn s 
 tnsarriioweverrmore independent of the weather than either Blackman's or Aland's 
 
 ^'""(i) Time reguvred to Change the Air of a School by Mechanical F.niiZaiion -By 
 mechanical ventilation the whole of the air in a school may be easily changed m less than 
 Steen minutes, and when the system is well arranged m less than ten mmutes. 
 
 The Statistics upon which these conclusions are based are given in the 
 iextand tables of the report. Some of the data must be modified when 
 ■specially large or small schools are referred to. We qiTote also from the 
 same report (p. 41) the following tabular statement of the advantages and 
 ■disadvantages of the several systems :— 
 
 Open Fires 
 
 Advantages : 
 
 1. More cheerful. 
 
 2 First cost much less than hot pipe systems. 
 
 3' Keeps air fresher than hot pipes, owing to draught up chimney. 
 
 4 So far as the Dundee schools are concerned, the temperature m the open fiie 
 
 schools was higher than in those heated by hot pipes. 
 5. The rooms of these schools will probably need painting less frequently than those 
 
 heated by other systems. 
 Disadvantages : 
 
 2. SS;^:.^— cost than stoves, or steam-pipes, or large hot-water pipes. 
 
 > A form of ventilating open grate (see p. 124) delivering fresh air above the mantel- 
 shelf. 
 
144 HYGIENE 
 
 3. Unequal distribution of heat. 
 
 4. Air more highly charged with micro-organisma. 
 
 Stoves 
 Advantages : 
 
 1. Smallest first cost. 
 
 2. Least annual cost. 
 
 3. Probably more effective heaters than open fires. 
 Disadvantages : 
 
 1. Greater labour in service. 
 
 2. Require more attention than open fires. 
 
 3. More liable to smoke than open fires. 
 
 4. More liable to get out of repair than open fires. 
 
 5. Not so cheerful as open fires. 
 
 Hot Pipes 
 Advantages : 
 
 1. Less labour in service than either open fires or stoves. 
 
 2. The class is not disturbed as in the case of the mending open fires and stoves. 
 
 3. More equal distribution of heat. 
 
 4. Air less charged with micro-organisms than when open fires are used. 
 
 5. On the whole the annual cost is probably slightly less than with open fires, but 
 
 more than with stoves. 
 Disadvantages : 
 
 1. Not so cheerful as open fires. 
 
 2. First cost much more than in the case of open fires or stoves. 
 
 3. Air not so fresh as with open fires. 
 On hot-pipe scJwols. 
 
 1. Small high-pressure pipes are cheaper in first cost than large low-pressure pipes. 
 
 2. Li those schools examined the air was better in rooms heated by small high- 
 
 pressure pipes than in those heated by large low-pressure pipes. 
 
 3. It takes longer to get up the heat with large than with small pipes. 
 
 4. Small pipes are less obtrusive in the rooms. 
 
 MechanicaIi Ventilation 
 Advantages : 
 
 1. Much greater purity as regards all the constituents. 
 
 2. Efficiency of ventilation much more independent of the weather ; whereas with 
 
 other systems the ventilation is worst when most needed. 
 
 3. The schools are warmer. 
 
 4. More equal distribution of heat and of fresh air. 
 
 5. Very effective in diminishing the number of micro-organisms, not only at the 
 
 time the mechanical ventilation is in operation, but also for a long time after 
 it has been stopped. 
 
 6. Eeduces draughts to a minimum. 
 
 In fact, the mechanical system heats and ventilates far better in every 
 respect than any other system, and is therefore far more conducive to health, 
 and comfort, and to success in teaching and learning. 
 Disadvantages : 
 
 1. Greater first cost. 
 
 2. Greater annual cost (except in the case of very large schools). 
 
 3. Though in a town where several schools were heated and ventilated mechanically 
 
 there would not need to be more than an ordinary caretaker in each of such 
 schools, yet one of these should be a man who had some knowledge of gas 
 engines &c. so that he could attend to any repairs which might be necessary. 
 Such a man would require a somewhat higher wage than an ordinary caretaker. 
 This, however, would amount to very little if distributed over a number of 
 schools. 
 
 We are unable to present such statistical information in a condensed form 
 for other kinds of builduigs, and we do not think that much valuable infor- 
 mation can be derived from a general account of the ventilation and warming 
 of any particular building without the details upon which its success or 
 failure depends. We therefore think it best to give here references to published 
 
WABMING AND VENTILATION 145 
 
 accounts of systems in actual use, so that the reader may be enabled to 
 master the details for a similar case to the one with which he has to deal. 
 
 There is probably material enough existing in a published form for the 
 compilation of a fairly complete report on the ventilation of Barracks and 
 Military Hospitals. The information is to be found in the ' General Report 
 of the Commission on the Means of Improving the Sanitary Condition of 
 Barracks and Hospitals,' printed in the Parliamentary Papers for 1801, with 
 its Appendix, issued in 1863 ; and in the ' Report of the Commission on 
 Barracks and Hospital Improvement and on the Ventilation of Cavalry 
 Stables ' (1866) ; and further in the ' Report of the Commission on the 
 Warming and Ventilation of Dwellings ' (1857); and in Special Reports 
 by F. de Chaumont, General Massy, and others, published in the ' Annual 
 Reports of the Army Medical Department,' vols. vi. to x. 
 
 The ventilation of Workhouses and Prisons has also received consider- 
 able attention and is referred to in many Government publications ; the best 
 linown of these is the ' Report of the Commission on the Cubic Space of 
 Metropohtan Workhouses' (1867). An account of the arrangements at 
 Pentonville Prison is given in the ' Prisons Report for 1847.' 
 
 Examples of the ventilation of Prisons, Courthouses, and other build- 
 ings, illustrated by clear diagrams, are given in R. Ritchie's * Treatise on 
 Ventilation ' (1862). Descriptions are to be found in various books and 
 periodicals of arrangements for warming and ventilation of all degrees of 
 complexity, from the rudimentary system of Gurney's stoves in the crypt of 
 St. Paul's Cathedral — which suffices for that building (' Mechanic's Maga- 
 iiine,' vol. Ixix. 1858, p. 443), to the most elaborate and complicated schemes. 
 
 Taking some of the different departments in order : — The ventilation of 
 Dwelling-houses is the subject of a Parliamentary Report already referred 
 to. One of its recommendations is that in ordinary living-rooms ventilation 
 should be provided for independently of the supply of air for the fire. 
 Messrs. Drysdale and Hayward have, in their book on ' Health and Comfort 
 in Housebuilding ' (1872), given plans which they have found successful 
 for supplying houses with suitably warmed air, and using the heat of the 
 kitchen chimney as the agent for the general ventilation of the house. 
 Arrangements are also described and figured in a book by Dr. Griscom, of 
 New York (see also Spon's ' Dictionary of Engineering,' art. Ventilation). 
 
 An account of the ventilation of the Lecture Theatre of the Conservatoire 
 des Arts et Metiers, by General Morin, is to be found in the ' Proceedings of 
 the Institute of Mechanical Engineers ' (1867). In this the fresh air is brought 
 in at the ceiling and the foul air withdrawn through perforations in the 
 risers of the seats. The elaborate arrangements for the ventilation of the 
 Theatre Lyrique are given in the same paper. General Morin also gives 
 descriptions of the ventilation systems of many other buildings in the works 
 of his already referred to in this article. 
 
 The ventilation of the Houses of Parliament has formed the subject of 
 many inquiries and experiments ; it has been treated in upwards of twenty 
 reports to Parliament.^ The original scheme proposed by Dr. D. B. Reid,- 
 combining mechanical ventilation and heat -suction, seems to have proved 
 unsatisfactory, partly in consequence of the interference with the original 
 design, on account of misunderstandings with the architect. Subsequently, 
 
 ' 1832, 1835, 1887, 1841 (four reports), 1843, 1846, 1847, 1848, 1852, 1854 (four reports), 
 1866, 1884, 1886 (three reports). The subject is still under discussion (see Times, July 25, 
 1891). 
 
 ^ Report of the Committee on the Ventilation of the Houses ofParliament, 1835 ; also Pr. 
 Raid's Illustrations of the Theory and Practice of Ventilation, 1844. 
 
 VOL. I. Ii 
 
UG HYGIENE 
 
 Sir G. Guniey introduced the system of ventilation by steam jets ; but in 
 1866, according to Dr. Percy, whose report, printed for the House of Commons- 
 (1866), gives a full description of the arrangements then and practically now 
 in use, mechanical propulsion had been entirely abandoned, and the ventila- 
 tion depends upon heat-suction alone, the air introduced bemg warmed by 
 Gurney's ' Steam Batteries.' The suction seems, indeed, to have proved more 
 than sufficient, for in 1884 the House was invaded by sewer gas from a main 
 sewer passing under the building. An interesting account of the earher 
 history of tnis elaborate series of experiments in ventilation is given iu 
 Ritchie's book already referred to. 
 
 In St. George's Hall, Liverpool, Dr. Eeid seems to have been able to> 
 carry out successfully his own ideas for a system of ventilation by mechani- 
 cal means. A brief account of the arrangement is given in the * Journal of 
 the Society of Arts,' vol. ii. 1853-4, p. 757, and vol. iii. 1855, p. 379. 
 
 The ventilation of South Kensington Museum is dealt with in the Report 
 of the Commission on that building (1869). 
 
 One of the most recent accounts of an attempt to carry out an elaborate 
 system of ventilation and warming is given by Mr. W. W. Phipson, the 
 engineer, in a paper in the ' Proceedings of the Institute of Civil Engineers,' 
 vol. Iv. 1879, p. 124, ' On the Heatmg and Ventilating Apparatus of Glasgow 
 University :' — 
 
 In the year 1864, when the building of the new University of Glasgow was determined 
 upon, a sub-committee of the professors, amongst whom were Sir William Thomson, Dr. 
 Allen Thomson, Professor H. Blackburn, and the late Dr. W. J. M. Eankine, considered the 
 general principles which should form the basis of the operation to secure for the new build- 
 ing the most efficient system of ventilation and warming. After a lengthened investigation 
 they came to the following conclusions : — • 
 
 1. That the foul air should be removed through outlets as near as possible to the 
 place where it is produced, e.g. passages under desks or seats. 
 
 2. That the total area of the orifices of such outlets should be about | square 
 foot per sitting, or 28 square inches. 
 
 3. That the total area of the orifices of the inlets for fresh air should be about double 
 the area of those of the outlets for foul air, or about § square foot per sitting. 
 
 4. That the inlets for fresh air should be at a high level and distributed round the cir- 
 cumference of the rooms. 
 
 5. That fresh air should be supplied both hot and cold, and each classroom be pro- 
 vided with means for mixing it. 
 
 6. That the total supply of air to the classrooms should be ^o cubic foot per 
 sitting per second. 
 
 7. That the sectional area of the channels or conduits for carrying away foul air should 
 be 55 square foot per sitting. 
 
 8. That the final outlets of the foul air should be so placed that none of it should return 
 to the buildiiig. 
 
 9. That the fresh air should be drawn from some place where the air is always pure. 
 
 10. That the fresh air should be forced in by one or any required number of suitable 
 machines. 
 
 11. That the foul-air conduits should lead to chimneys in suitable positions provided 
 with furnaces capable of being hghted, the area of the furnace grate being -^^ square foot 
 per sitting. 
 
 12. That the hot part of the fresh air should be heated by hot-water tubes, and that 
 the most efficient position for such tubes was in the vertical passages in which the current 
 of air ascends. 
 
 In working out these suggestions it was found that the allowance of i^ 
 cubic foot of fresh air per sitting per second for classrooms . . . was too 
 much, and that the vertical air-shafts necessary to supply this large volume 
 of air assumed such proportions that the walls would not admit of their con- 
 struction.' It was therefore altered, but still the total volume passing through 
 the apparatus was to be 1,800,000 cubic feet per hour. It appears also that 
 
WARMING AND VENTILATION 147 
 
 suggestion 5 — about supplying cold fresh air as well as warm, with pro- 
 vision for mixing — was also abandoned. 
 
 In this paper and the discussions following it, which occupied two evenings, 
 a good deal of light is thrown upon the whole question. Incidentally 
 accounts are given of the ventilation of the Free Trade Hall and Boyal 
 Exchange, Manchester, by Mr. Constantine. 
 
 An abstract of the account of the arrangements for the Vienna Opera House, 
 from the Proceedings of the ' Soci6t6 des Ingenieurs-civils,' 1880, p. 431, is 
 given in the 'Proc. Inst. C.E.' vol. Ixiv. p. 450, and also of those of the 
 Bourse in Berlin, ibid. vol. Ixxi. p. 522. In this connexion we may also 
 refer to a paper by the late Eobert Briggs, ' On the Ventilation of Halls of 
 Audience,' * Trans. Amer. Soc. G.E.' vol. x. 1881, p. 53. 
 
 For the description of the ventilation of Hospitals the reader maybe 
 referred to the article on Ventilation in Spon's ' Dictionary of Engineering.' 
 General Morin gives an account of the ventilation of Guy's Hospital (built by 
 Rhode Hawkins) and of other hospitals in vol. i. of his ' Etudes sur la Venti- 
 lation,' p. 34, and of the Hopital Lariboisiere, in the same volume, p. 356, with 
 full detail, and an investigation cf the action. The system is based on the 
 injection of air by fans. Dr. Arnott ventilated the hospital at York by pumps 
 of his own design, worked by water power (see Arnott, ' On the Smokeless 
 Fireplace ' &e. or Ritchie's ' Treatise on Ventilation '). 
 
 On the general principles of the ventilation of hospitals, there is a useful 
 article in ' Fraser's Magazine ' for November 1875. 
 
 Other departments of the subject are of a more technical nature. The 
 ventilation of ships has received a good deal of attention, since Dr. Arnott 
 made a report to the General Board of Health on the subject, which is con- 
 tained in their reports on Quarantine, 1849-54. The modern development of 
 this department for the cooling of ships &c. by mechanically cooled air is 
 fully treated in a paper by J. J. Coleman on Air-refrigerating Machinery 
 ('Proc. Inst. C.E.' vol. Ixviii. p. 146) and the discussion upon it. 
 
 For information as to the ventilation of mines and tunnels, the technical 
 journals must be referred to. For the former the ventilating fan seems to be 
 coming more into use, and very large machinery is being employed for the 
 purpose. Mechanical ventilators are now made to deliver 100,000 to 250,000 
 cubic feet of air per minute ; the Guibal fan is made up to 50 feet in diameter, 
 the Waddell fan up to 45 ft., while the quicker moving Schiele fan reaches 
 15 ft. This subject is considered in the work of M. Murgue, to which reference 
 has already been made,^ and is also discussed in the ' Proceedings of Inst, of 
 Mech, Eng.' 1875, p. 317, by W. Daniel. 
 
 It appears from the ' Proceedings of the Institution of Civil Engineers ' that 
 the ventilation of underground railways sometimes receives a certain amount 
 of attention. Exceptional cases of ventilation occasionally require treatment, 
 which is noticed from time to time (see, for example, ' Electrician,' Feb. 22, 
 1889, p. 452). 
 
 The ventilation of sewers is a special department (see ' Annual Reports, 
 Metropolitan Board of Works,' 1866-68-73). 
 
 A number of contrivances have been devised for the ventilation of railway 
 carriages without draughts, but so far their success does not seem to be 
 sufficiently conspicuous for their general adoption. 
 
 A general summary of the special points to be considered in the ventila- 
 tion of buildings of special character is given by General Morin, ' Manuel,' 
 § 163 et seq. 
 
 ' See also Ee;ports on the Ventilation of Mines, Parliamentary Beports, 1850 ; Proc. 
 Inst. Mech. Eng. 1877, p. 92 ; Proc. Inst. C.E. xliv. p. 18, Ixii. p. 396, xci. p. 541. 
 
 L 2 
 
148 HYGIENE 
 
 Taking all the points into consideration, it will be seen that although 
 great progress has been made of late years towards the satisfactory solution 
 of the problem of combined warming and ventilation, especially by the 
 development of the mechanical system, we are still unable to regard the 
 question as definitely settled. The most important point is that the pre- 
 scribed amount of air for adequate ventilation (p. 11 G) is greater than can be 
 supplied without very great extension of systems hitherto adopted. For 
 crowded rooms m particular the areas of inlets and outlets would require to 
 be enormous, and the maintenance of the flow would necessitate very exten- 
 sive machinery. But, provided that those interested are willing to pay the 
 price, the difficulties could no doubt be overcome. It is to be remarked that 
 at present very little is accurately known, and very little account is taken 
 of the local circulation of air in a large room, and so no advantage is con- 
 sciously taken of this circulation in the provisions for ventilation. It would 
 seem to be possible by a more accurate study of the distribution of the 
 currents of air in a large room to remove the fouler portion of it more directly, 
 and thus prevent its mixing with the purer portion, and so to reduce the 
 amoiuit of fresh air necessary. 
 
 Hitherto attention has been directed to this branch of the subject, mainly 
 with the important object of avoiding draughts, and some measure of success 
 lias been attained; but when the necessary conditions for securing that object 
 have been formulated and clearly understood, the next step may well be to 
 direct the air supply with a view to its economy in comparison with its useful 
 efi'ect. 
 
 The economy of cost of heating, as well as the efficiency of ventilation, 
 also depends largely upon this element, and for securing the same object 
 more accurate knowledge of the magnitude of the air currents in ducts and 
 the resistances of the ducts would render valuable aid, so that we look to the 
 numerical expression of the details of circulations, both general and local, to 
 provide the means of further progress. 
 
METEOROLOGY 
 
 BY 
 
 G. J. SYMONS, F.E.S. 
 
 SECRETARY ROYAL METEOROLOGICAL SOCIETY 
 
INTEODUCTOEY 
 
 Thirty years ago it would perhaps have been well to commence this section 
 by demonstrating the relation between Meteorology and Public Health, but 
 the necessity has rapidly diminished until now one sentence, just as a 
 reminder, is all that can be required. 
 
 I have said thirty years, but might almost as well have said ninety, for 
 as far back as 1796 Dr. William Heberden, F.E.S., submitted a paper to the 
 Eoyal Society, ' Of the Influence of Cold on the Health of the Inhabitants of 
 London,' and hterature of that class has gradually increased until it fills 
 many shelves. One cannot take up the Eeports of the Eegistrar-Generals, of 
 the Army Medical Department, or of the majority of the Medical Officers of 
 Health, and of the Superintendents of our County Lunatic Asylums, without 
 •coming upon masses of meteorological data. Medical men, like Acland, 
 Ballard, Mitchell, Moffat, Scoresby-Jackson, Shapter, Tripe, and scores of 
 'Others, have discussed the relation of the two subjects. It is not for me to 
 follow in their path, or review their work, but to explain as clearly as possible 
 the construction and use of the various instruments employed by meteorolo- 
 gists, what are the good and the bad features of each, how they are to be 
 placed, when they are to be read, how the observations are to be entered, and 
 .how they shotild be worked up and presented to the public. 
 
 ATMOSPHEEIC PEESSUEE 
 
 It is not very easy to explain why it is an almost invariable rule that 
 when the numerous branches of meteorology have to be treated of, the baro- 
 .meter takes precedence over the thermometer. It is beyond the province of 
 "this section to consider the effect of varia.tions of atmospheric pressure upon 
 the human frame ; ^ we have here to consider (1) how atmospheric pressure is 
 measured, (2) what are the variations in its amount. Barometers may be 
 roughly divided into two groups, those in which the pressure of the atmo- 
 sphere is indicated by the length of the column of fluid (be it water, glycerine, 
 or mercury) which it will support, or by the pressure which it exerts on the 
 sides of a box which has been nearly exhausted of air, and then hermetically 
 sealed. It is unnecessary here to deal with so elementary a matter as the 
 principle of the barometer, but in explaming how to transport, erect, and read 
 a thoroughly good mercurial barometer, most of the essential features will be 
 incidentally mentioned. Nor is it necessary to spend time in specifying the 
 faults of old patterns — a wheel barometer may be ornamental in a hall, may 
 even sometimes induce one to take an umbrella, but is absolutely useless as 
 a scientific instrument. For absolute accuracy there are two excellent pat- 
 terns represented in figs. 53 and 54. Fig. 53 represents a standard barometer 
 >of the type introduced at the beginning of this century by a Frenchman, M. 
 Fortin. The enlarged sketch, fig. 55, illustrates the special merit of this 
 .pattern. A moment's consideration wiU convince anyone that with a verti- 
 
 ' Eeference to La Pression Barom6triqi.ie, by Paul Bert (Paris, 1858), may, however, be 
 ■permitted. 
 
152 
 
 HYGIENE 
 
 cal tube and a cistern of mercury at the bottom, a fall of the barometric? 
 column must produce a rise in the cistern, and vice versa. If then the scale 
 of inches on the upper part of the instrument be laid off from a zero at any 
 fixed point in the cistern, the barometer will read wrongly at every point but 
 
 one ; its motions will always be too 
 small in the ratio which the area of the 
 cistern bears to the area of the tube. 
 In the Fortin barometer this error is 
 removed by laying off the scale from 
 the extremity of the ivory point, above 
 A, fig. 55, and by, at each observation, 
 so turning the screw at B that the mer- 
 cury in the cistern is exactly in contact 
 with that extremity of the ivory point. 
 The other way of re- 
 moving the difficulty 
 is that shown in fig. 
 54, the so-called Kew 
 pattern barometer, in 
 which the cistern is 
 closed (except as re- 
 gards a wooden air 
 inlet) and, its area 
 having been accu- 
 rately determined, 
 the inches on the 
 scale are not real 
 inches, but inches 
 of pressure, i.e. true 
 inches so shortened 
 as to compensate for 
 the rise of the mer- 
 cury in the cistern. 
 It may be well to 
 point out the merits 
 and demerits of each 
 of these patterns. 
 The Fortin is the 
 more difficult to make, and is therefore 
 the more costly of the two, and the 
 adjustment of the mercury to the ivory 
 point requires care ; on the other hand, 
 .it has two, if not more, great advan- 
 tages ; (1) the mercury can be screwed 
 up so as to entirely fill the tube, and it 
 then travels with less risk than if the 
 tube be not full ; (2) as long as the tube 
 is not broken, and does not contain air, 
 
 Fig. 53. 
 
 Fig. 54. 
 
 and there is mercury enough to fill the 
 cistern up to the ivory point, the reading must be correct. The Kew pattern 
 is lower in price and easier to observe, it is not so sensitive as a Fortin, 
 because it is necessary to contract the tube, and if mercury escapes from the 
 inner cistern the observer may continue to record the readings unconscious 
 that they have thereby become worthless. 
 
METEOBOLOGY 15a 
 
 As regards the transport of barometers there is always great difficulty. 
 The Fortin barometers should be so screwed up that the mercury rests steadily 
 against the top of the tube, but this screwing up must not be done recklessly 
 or the top of the tube may be knocked out by the mercury (for being a nearly 
 perfect vacuum the mercury hits it like a pneumatic hammer), or the mercury 
 may be squeezed through the pores of the leather bag, or even the bag itself 
 burst. After being well screwed up, the barometer should be turned cistern 
 uppermost, and if possible carried to its destination in that position. If this 
 cannot be done it must be arranged to travel quite flat, and if practicable trans- 
 versely to the direction of motion — e.g. in a gig, a barometer will travel 
 better lying in the direction of the axle, than in that of the shafts. A broken 
 barometer is not worth much more than a third of a sound one, hence it is 
 true economy to spend a little extra for additional packing. The Kew 
 pattern barometers are said to travel best lying flat. 
 
 On receipt of a barometer, the first thing is to select a good position. It 
 should be one on which the sun rarely shines, and yet which has a good light, 
 indoors, and where it is not likely to be interfered with. The Bl-inch line 
 should be at the level of the observer's eye ; if the barometer be a Fortin, 
 this should be rather higher, e.g. by using a stool, than for a Kew pattern, 
 because with the Fortin it is also necessary that the observer see comfortably 
 the ivory point in the cistern. On opening the case, the barometer itself will 
 be found packed separately from the board on which it is to be suspended ; 
 this board should be firmly fixed in position, and then the barometer should 
 be hung on it. Before actually fixing the barometer, it will be well to turn 
 it cistern downwards, and slightly unscrew the cistern so as to let the mer- 
 cury down an inch or two, then incline the barometer gently so that the 
 mercury may run up to the top of the tube. It ought to elicit a sharp me- 
 tallic click, but it may give only a dull thud ; if on two or three trials it always 
 gives a dull sound, it is because air has got into the tube and forms a cushion 
 at the top. It is usually not difficult to remove the air in the following 
 manner. Screw the mercury up until it is within about half an inch of the top 
 of the tube, turn the barometer gently cistern uppermost, and tap the top of 
 it on a thick rug, or on the toe of a boot for five minutes, then screw the 
 mercury as tight as can be done without exerting strength enough to force 
 any mercury through the wash-leather bag, turn the barometer cistern down- 
 wards, release the mercury and try whether the tap is not then clear and 
 sharp. In all probability it will be, for the air has been gradually tapped 
 out of the tube ; if it is not gone, the process must be repeated either for a 
 longer time, or with somewhat stronger taps. 
 
 At the bottom of the board will be found a ring with three adjusting^ 
 screws. These should be nearly withdrawn, the barometer left free to assume 
 a vertical position in the ring, and then the screws gradually turned in mitil 
 they press upon it. Care must be taken that the screws are not turned after 
 they are in contact with the barometer, or their pressure will prevent its 
 remaining perpendicular, and then it will read too high. 
 
 Assuming the barometer free from air, and duly suspended, the next thing 
 is to read it. In the Fortin pattern the first matter to attend to is the 
 cistern : the mercury must be let down until its level just touches the tip of 
 the ivory point ; the best plan is to lower it rather too far, and then raise it 
 slowly till it just touches. 
 
 Now we have to deal with the reading — by no means a comphcated 
 matter, but perhaps the most so of anything that a meteorological observer 
 has to do. The first process is very easy : the observer has only to turn the 
 screw of the vernier until he produces the state of things represented in 
 
154 
 
 HYGIENE 
 
 fig. 5G — i.e. his eye, the front of the vernier, the summit of the mercurial 
 column, and the back of the vernier all in one straight line. The second 
 stage is to some persons a puzzle. The principle of the vernier- — or nonius, 
 as it used to be called — is the very simple one that if you put side by side 
 two scales, on one of which a given length is divided into ten parts, and on 
 
 the other into nine, the top and bottom lines 
 will coincide, but the intermediate ones will each 
 be one-tenth higher than those on the first scale ; 
 and so small excesses can be easily measured. 
 Fig. 57 gives the vernier of a Fortin barometer 
 in two positions : in A we see that the mercury 
 
 1^ is slightly above 29-6 ; this can be seen from 
 the fixed scale ; the line with the arrowhead is 
 29^ — i.e. 29'5 ; each of the long lines on the 
 scale is '1, and the short ones '05 ; the mercury 
 is not only above 29'5 but above 29'55 (the first 
 short line above 29/^), and it is above the long 
 line, and therefore above 29"G — it remains to 
 see how much. In using the vernier the first thing is to decide which line 
 on the movable scale is level with one on the fixed one ; evidently it is the 
 third line above the figure 1 on the movable scale. We have only to read 
 that and add it to the 29"6 and all is finished. Now the first rule is that 
 
 the figures on the movable scale are 
 hundredths of an inch ; therefore if the 
 line marked 1 had been level with a line 
 on the fixed scale one hundredth woiild 
 have had to be added to 29'6 — i.e. 
 
 29-60 
 •01 
 
 29-61 
 
 would have been the reading ; but the 
 line which cuts is three higher, and as 
 each of these unnumbered lines repre- 
 sents y-j^ths, we have -002 x 3 = -006 
 above the "01 — i.e. -016 to add to the 
 29-6, and so it comes out 29-616. To 
 make the matter quite clear, example 
 B is given. Here the mercury is above 
 29 inches, and shghtly above 29-05 (the 
 first short line) ; looking up the vernier 
 we see that the line which cuts is the 
 fourth, then -002 x 4 = -008, which, 
 added to 29-05, makes 29-058 inches. 
 
 Assuming that the observer has 
 thoroughly mastered the vernier, and 
 the mode of setting it to the top of the 
 column, we may now say a few words as 
 to the routine of taking a reading with 
 a Fortin: (1) read the attached thermometer to the nearest whole degree, 
 and enter it ; (2) lower the mercury in the cistern until it is quite clear of the 
 ivory point, and then raise it gently until it just touches it ; (3) bring the 
 vernier to its true position ; (4) read off and enter the reading ; (5) it is well, 
 but not indispensable, to lower the mercury in the cistern, so that it does 
 
 29.61G. 
 
 29-058. 
 
 Fig. 57. 
 
METEOBOLOGY 
 
 155 
 
 not remain in, or liable to, contact with the ivory point, as oxidation of the 
 surface is hastened by such contact. 
 
 With a Kew pattern barometer the routine is the same except that (2) 
 and (5) have not to be done. 
 
 There are three corrections which have to be applied to barometric 
 readings ; (1) index error, in which the effect of capillarity is now usually 
 included; (2) temperature ; (3) altitude. 
 
 Index error is usually very small, and is generally the same at all parts 
 of the barometric scale. It is determined at the central observatory in each 
 country and its amount entered on the certificate sent with the barometer. 
 
 TemperaUire. — If two barometers are in two adjoining rooms at the 
 same level, but the one room is warm and the other cold, the barometers 
 will differ, because in the warmer room the mercury has dilated and has 
 therefore become of less specific gravity, so that in the warm room the 
 barometer Avill read the higher. And the matter is further complicated by the 
 fact that the inches on the brass scale also vary in length according to tem- 
 perature, and are of their proper length only at 62° F. We do not employ 
 barometers to tell us temperature but pressure, therefore it has long been 
 agreed throughout all nations that barometer readings shall be reduced to 
 what they would have been had both the mercury and the brass scale been 
 at 32° F. 
 
 For barometers made (as all good ones are) with brass scales the cor- 
 rections are as under : — 
 
 Temp. 
 
 27 inches 
 
 28 inclies 
 
 29 inches 
 
 30 inches 
 
 31 inches 
 
 30 
 
 -■004 
 
 -•004 
 
 -•004 
 
 - ^004 
 
 -•004 
 
 40 
 
 -•028 
 
 -•029 
 
 -•030 
 
 -•031 
 
 -•032 
 
 50 
 
 -•052 
 
 -•054 
 
 -•056 
 
 -•058 
 
 -•060 
 
 60 
 
 -076 
 
 -•079 
 
 -•082 
 
 -■085 
 
 -•087 
 
 70 
 
 -•100 
 
 -•104 
 
 -•108 
 
 -•111 
 
 -•115 
 
 80 
 
 -•124 
 
 -•129 
 
 -•133 
 
 -•138 
 
 -•143 
 
 90 
 
 -•148 
 
 -•153 
 
 -•159 
 
 -•164 
 
 -•170 
 
 100 
 
 -•172 
 
 -•178 
 
 -•184 
 
 -•191 
 
 -•197 
 
 Detailed tables giving the values for each degree F. and for each half- 
 inch of the barometer will be found in Guyot, Hazen, Marriott, Scott, and 
 several other works. 
 
 ANEEOIDS 
 
 Aneroids should never be relied upon for fixed stations ; they are extremely 
 useful instruments, and for some purposes invaluable ; but after working 
 well for periods, which may be a week, or may be twenty years, they will 
 occasionally go hopelessly wrong. Checked, however, from time to time 
 against a mercurial standard, an aneroid is, as a measurer of altitude, in- 
 valuable. The principle of the aneroid is very simple. Suppose two saucers 
 made of corrugated iron, turned face to face, and soldered round the rim, 
 and that by a small tube the air was exhausted from the interior, and the 
 tube then closed, it is evident that the two sides of this corrugated flat box 
 would be forced together by the pressure of the atmosphere, and that the 
 compression would be equal to the equilibrium between the strength of the 
 box and the pressure of the atmosphere ; therefore, the greater the atmo- 
 spheric pressure, the closer will the sides be squeezed together. This motion 
 is, by suitable levers, made to turn the hand on the face of the aneroid. An 
 aneroid should always be read in one position, not sometimes hanging on a 
 nail and sometimes lying on a table. 
 
156 
 
 HYGIENE 
 
 EECOEDING BAEOMETER 
 
 There are many modes whereby barometers have been so arranged as to 
 produce automatically a pencil, ink, or photographic record of the changes 
 in the pressure of the atmosphere Most of these are too elaborate and 
 costly for employment except in observatories, and therefore do not need 
 mention here. But one very cheap and ingenious pattern has been brought 
 out recently by MM. Richaid Freres of Paris, to which a few lines may be 
 devoted. Power is obtained from s series of aneroid vacuum boxes, the motion 
 of which is multiplied by a long lever. The end of this lever carries a very 
 small triangular box (the pen) filled with ink, which presses lightly against 
 the paper-covered cylinder. Once a week a clock contained in this cylinder 
 is wound up, and a new sheet of paper put on the cylinder, the pen on 
 the extremity of the lever is provided with fresh ink (glycerine and a little 
 aniline ink), and then, as the cylinder is rotated by the clock contained within 
 
 Fig. 58. 
 
 it, and the lever is higher or lower as the barometer is higher or lower, a 
 very clear continuous ink record is produced. In fig. 58 the pen is at 7 p.m. 
 on a Wednesday and the pressure is 768 milhmetres or 30-28 inches. Papers 
 can be had ruled to either metrical or English scale. 
 
 As has already been pointed out, aneroids such as this cannot be reHed 
 upon as certain to give absolute accuracy, but checked from time to time 
 against a mercurial standard they are most useful, and the diagrams are very 
 interesting. 
 
 MEASUEEMENT OF HEIGHTS 
 
 It would be beyond our hmits to give elaborate rules and formulae for the 
 barometric measurement of altitudes, but it may be convenient to give 
 sufficient simple ones to enable any one to form (e.g.) a rough idea as to 
 whether a spring in one valley could be utilised in another. It is imma- 
 terial whether an aneroid or a mercurial barometer be used ; in either case 
 the barometer should be read three times. Suppose that it is required to 
 
METEOBOLOGY 
 
 157 
 
 know the height of A above B. Eead the barometer at A, take it to B, read 
 it there, go back to A and read it the third time. Suppose the readings 
 to be 
 
 in. in. 
 
 A (1st time) 30-10 B 20-90 
 A (2nd time) 30-14 
 Then take the mean at A=30-12 
 „ reading at B=29-90 
 
 Difference '22 inch. 
 
 The simplest rule is, move the 
 decimal two places to the right and 
 multiply the difference by 9, thus : 
 •22 
 9 
 
 198= difference in feet. 
 
 23 
 
 S* 23 
 
 24 
 
 iS! 25 
 
 2G 
 
 27 
 
 28 
 
 29 
 
 ■ 30 
 
 A closer approach to the truth g 26 
 
 can be obtained with great ease ^ 27 
 
 by means of the annexed diagram,^ | 
 
 and attending to the following 28 
 
 rules — (1) Find the mean pressure ^9 
 at the two stations ; in the above 
 
 example 80:^+25:5?=80-01. (2) » 
 
 ^ 31 
 
 Find (or estimate) the mean tem- 
 perature ; suppose it to be 70°. (3) 
 Look in the diagram where the line 
 for 30 inches crosses that for 70°, 
 and read off the slanting value for 
 
 that point ; it will be seen to be the dotted line for 9^ or 9*5 that'll the multi- 
 plier to be used, and so we get 
 
 •22 
 
 9-5 
 
 30° 40° 50° 60° 70° 80° 
 Mean Temperature. 
 Fig. 59. 
 
 110 
 
 198 
 
 209-0, or 209 ft. instead of 198 ft. as by 
 the simpler rule. 
 
 Eeference to the diagram will show that 9 would have been absolutely 
 right at a temperature of 45°, and that the multiplier rises with the tem- 
 perature. 
 
 EEDUCTION OF BAKOMETER TO SEA-LEVEL 
 
 For sanitary purposes we advise that this be never done ; it is obviously 
 of no medical or sanitary importance to a resident at Buxton to know what 
 the pressure of the barometer would be if he dug a well 1,000 feet deep and 
 went to the bottom of it. Eeduction to sea-level is a necessity to the 
 meteorologist, but not to the climatologist or the student of liygiene. If 
 either of them wishes to apply the correction accurately, he can consult 
 Guyot's, Marriott's, or Scott's tables; if he wishes to know it approximately, 
 he can for small elevations add one-tenth of an inch for each hundred feet. 
 
 » From Pocket Meteorological Tables. By G. J. Symoiis. 
 
158 HYGIENE 
 
 DAILY EANGE OF THE BAROMETER 
 
 In most parts of tlie world the barometer has daily a double tide, rising 
 to maxima about 10 a.m. and 10 p.m. and falling to minima about 4 a.bi. and 
 4 P.M., but the amount of these fluctuations is small, and I am not aware that 
 it has ever been suggested that they in any way affect public or individual 
 health. 
 
 EXTREMES OF PRESSURE 
 
 At the level of the sea the average pressure may be put at 30 inches, and 
 the variations at from 27 inches as the minimum to 31 inches as the maximum. 
 When I mention that in his memorable Wolverhampton ascent Mr. Glaisher 
 went so high that the pressure fell to less than 8 inches, and that in the 
 caisson for the great Forth Bridge the men worked in a chamber so far under 
 water that the barometer stood at 72 inches, it will be seen how great is the 
 range which the human frame can sustain and how insignificant as compared 
 with it are the atmospheric fluctuations of 4 inches — 4 against 04. 
 
 TEMPERATURE 
 
 A few prefatory remarks on thermometers in general will probably not 
 be superfluous, as few persons know the reasons for the very different patterns 
 of thermometer, or how to select that best adapted for the object which they 
 have in view. It is very difficult to compress within any reasonable limit 
 all that ought to be said upon the subject, and therefore my remarks must of 
 necessity be somewhat curt. Thermometers may be classified as Ordinary,. 
 Registering, and Recording. 
 
 Ordinary Thermometers 
 
 In early days these consisted of glass tubes filled with alcohol or mercury^ 
 tied with wire to slabs of wood or of ivory, on which the divisions were marked ; 
 the bulbs were large and the glass was often very thick. Alcohol (and other 
 liquids) proving inferior to mercury, the latter is now in good instruments 
 alone employed (except, as will be noted presently, under the head of register- 
 ing thermometers) ; the bulbs are thin and much smaller, because opticians 
 have learned how to make the bore of the tubes oval, and to mount them 
 with the broad side of the tube foremost. This gives an appearance of breadth 
 to the column, and therefore makes it easily seen, while the smallness of the 
 bore enables the size of the bulb to be reduced, and the smaller the bulb the 
 more sensitive the thermometer. If a large bulb be indispensable it is best 
 made as a cylinder, not as a sphere, because a cylinder exposes more surface, 
 and therefore takes up the temperature more rapidly. Another great improve- 
 ment, which we believe was due to Messrs. Negretti and Zambra of London,. 
 is the working into the tube of a layer of opal glass. This (which is called 
 enamelling) white background throws up the thread of mercury, and has done 
 more than anything else to enable thermometers to be made with small, and 
 therefore, very sensitive bulbs. Again, now, all good thermometers have the 
 scale etched on the tube, which (1) lasts as long as the thermometer itself,, 
 instead of perishing as did the old wood and ivory ones ; (2) which cannot 
 slip about as did the old frames ; (3) which avoids parallax by bringing the 
 division as close as possible to the mercurial column. For ordinary house or 
 
METEOROLOGY 159 
 
 hospital use, glass or porcelain slabs to carry and protect the thermometer 
 are the cleanest and most permanent ; glass is better than porcelain because 
 sometimes moisture penetrates the glaze of the latter, and, freeziugunderneath, 
 splits off flakes of the porcelain, disfiguring, if not ruining, the instrument. 
 This evil seems, however, to be decreasing, owing probably to improved 
 manufacture. There is a notable difference between British and Continental 
 makers as regards the mounting of thermometers, and probably (as is fre- 
 quently the case) something between the extremes is best. Continental 
 makers of high-class thermometers seem to consider that the tube should 
 have no mounting whatever ; they form a loop in the glass of the end of the 
 stem and consider the instrument complete. An English maker, on the 
 contrary, nearly buries his tube in a wood, glass, or zinc mounting. Each 
 has a good feature, and each a bad one. The Continental plan leaves the 
 thermometer free to assume the temperature of air, or of any body in which 
 it is immersed, but it leaves the tube very fragile. The English plan protects 
 the tube from breakage, but not infrequently so surrounds the bulb as to cause 
 it to show a temperature intermediate between that of the slab to which it is 
 attached and that of the air or other surrounding medium. 
 
 Thermometers can now be had of almost any degree of minuteness or 
 delicacy which can be imagined. I have seen some with their tiny bulbs 
 inside the green shoots of growing plants ; others with cylindrical bulbs 
 coiled flat like a snake, with the scale rising perpendicularly from the centre, 
 the coiled bulb not so large as a shilling, being for taking local temperatures, 
 and the scale, perhaps 1\ inch long, for reading them off. And the accuracy 
 of thermometers is now very remarkable, pro\dded that nothing unreasonable 
 be expected of the makers. Some persons imagine that an accurate thermo- 
 meter can be made of any required pattern as quickly as a coat. This is 
 impossible, and a thermometer made in a liurry generally proves a bad one. 
 Until within a very few years any mercurial thermometer on which the 
 divisions were etched within a year of the bulb being blown and filled, was 
 sure to become from a quarter to half a degree too high within the following 
 six months, wherefore the best makers kept large stocks of filled, but un- 
 graduated tubes, and rarely put the divisions on until they were two or three 
 years old. Some years since Mr. Denton, a skilled thermometer maker, 
 discovered that, by a process of slow annealing in hot oil, this change could 
 be effected in weeks instead of years, and now, if the matter be insisted upon, 
 and a reasonable price paid, thermometers can be bought which have what 
 is called a constant zero — i.e. which will not read higher by age. Now it 
 will be seen why thermometers should not be made hurriedly, and that if a 
 purchaser insists upon one being made and delivered within a week, the 
 maker will probably so divide it that it shall read 0-2° or 0*3° too low when 
 supplied, because he knows that eventually it will rise not only so as to become 
 correct, but possibly 0*2° or 0"3° too high. 
 
 The only ordinary thermometer required for climatological purposes is 
 the one mounted along with another to form an hygrometer. I shall, there- 
 fore defer its description until I write upon hygrometry. 
 
 Kegisteeing Thbemometees 
 
 There are two terms often confused and misused by amateurs — self-regis- 
 tering and self-recording ; the word ' self ' being in both cases redundant and 
 misleading. The proper application is registering to anything which moves 
 an index which can be subsequently examined : a gas meter is a self- 
 registering apparatus ; on the contrary, any instrument which by pen, pencil. 
 
ICO 
 
 HYGIENE 
 
 photography, or otherwise makes a continuous trace upon paper, &c., pro- 
 duces a record and is recording. 
 
 It would be quite out of place to describe any patterns of registering 
 thermometer, except those in general use ; this will exclude probably a 
 hundred patterns, and leave scarcely half a dozen — the survival of the fittest. 
 The oldest, invented about 1780 by James Six of Canterbury (not Col- 
 chester, as is often stated), is not now used for climatological purposes, but 
 is very popular as a window thermometer, and is convenient as a check on 
 the warming of public buildings, hospital wards, &c. ; it is also much used 
 for taking the temperature of the sea, and can do so even under several 
 miles of water, and when the pressure is two or more tons to the square inch. 
 Fig. 60 represents the instrument as fitted for a window. The bulb of the 
 thermometer is the long cyhnder in the middle, which, as well as the upper 
 part of the ' cold ' tube, is filled with alcohol ; below this the tube is filled 
 with mercury, Avhich passes round the bend at the bottom and part way up 
 the ' heat ' tube. Above this the space in that tube is also 
 filled with alcohol, except that in the upper part of the chamber 
 at the top there is confined some air which was sealed in at 
 so low a temperature that at any ordinary temperature it exerts 
 a pressure upon the alcohol in the ' heat ' tube, and then, 
 through the mercury, upon the alcohol in the ' cold ' tube. 
 The effect, or supposed effect, of this is to keep the two liquids 
 in their place, and to prevent air bubbles escaping from the 
 alcohol and deranging the instrument. These are its drawbacks, 
 and they make it a very bad traveller. A Six's thermometer, 
 if well made and once safely in position, is the handiest self- 
 registering thermometer in use, but it should be moved as little 
 as possible and always carried vertically. The difficulty arising 
 from motion will soon become evident. The indexes consist 
 of three parts (and are not always made of the same shape 
 or materials) : (a) the steel needle ; this is essential but it 
 is sometimes bare, sometimes enclosed in a little glass tube ; 
 (&) knobs of glass at each end of the index, the lower one to 
 be driven up by the mercury ; (c) springs to hold the index 
 in position and prevent its falling; these are sometimes 
 bristles, sometimes bent threads of glass. The action of the 
 thermometer is simple and very ingenious. Suppose that the 
 instrument has just been read ; to set it ready for the next 
 observation take a horse- shoe magnet and place it successively 
 at the side of each needle and draw the indexes gently down 
 until they rest upon the mercury ; the lower knob of each 
 will then read alike and will show the temperature at that 
 instant. Having done so, suppose that the temperature rises, the alcohol in 
 the bulb will expand, it will pass the index in the ' cold ' leg, and push down 
 the mercury, but that will compel the mercury to rise in the ' heat ' leg, and 
 to drive up the index in it until the temperature ceases to rise, when the 
 index will be left behind and the maximum temperature will be registered 
 by the position of the bottom of that index. Just the reverse will happen 
 on a fall of temperature, for then the spirit in the bulb will contract, the 
 pressure in the chamber at the top of the ' heat ' leg will force the mercury 
 down in it and up in the ' cold ' one, and it will push that index upwards as 
 long as the temperature continues to fall. It is obvious from the above that 
 the temperature scales must read downwards in the ' cold ' and upwards in 
 the ' heat ' leg, and that in each leg the bottom of the index shows respec- 
 
 MtPtlll / 
 AZAVGRA / 
 
 jantan. /; 
 
 
 i %l 
 
 p 
 
 "- 'SU^ 
 
 
 
 ^ 
 
 — : a : 
 
 hio 
 
 20 -[ ::; 
 
 
 30['^' : 
 
 \m 
 
 '^f H 1 : 
 
 :•— 
 
 m \ |: 
 
 !90 
 
 1 -~ • ' ■ 
 
 1— 
 
 50^*-!: 
 
 m 
 
 ^m^ 
 
 ;70 
 
 — : : ■ 
 
 -^ 
 
 a 
 
 ISO 
 
 son : 
 
 ;50 
 
 ^-i 
 
 40 
 
 ' 100 ; 1 
 
 1 
 
 — ; ■ 
 
 S{\ 
 
 no; 
 
 iif 
 
 — ; ; 
 
 :10 
 
 
 - 
 
 Fig. 
 
METEOROLOGY 
 
 161 
 
 iively the lowest and the highest temperature reached since the instrument 
 was last set. It is evident that a thermometer of this kind placed inside a 
 fixed, locked, wire cage gives evidence of the variations in temperature 
 between two consecutive visits of the superior officer. 
 
 Before leaving this pattern it is necessary to mention one peculiar error 
 to which this thermometer is liable. Sometimes alcohol will ooze round by 
 the side of the mercury, and so pass from the ' cold ' to the ' heat ' leg. This 
 is doubly bad {a) because, inasmuch as the scales run in opposite directions, 
 it can only be detected by comparison with another thermometer, and {h) 
 because no one but an optician can rectify the evil. 
 
 EUTHEEFOED'S MINIMUM 
 
 All the world over this very simple pattern of thermometer holds the 
 iirst place as a minimum thermometer ; not that it is perfect — it has several 
 faults, but because no other has been able to displace it. It was invented 
 nearly a century since and described in 1794 in the ' Ed. Phil. Trans.' 
 Its action, as will be seen from fig. 61, is very simple. The bulb and part of 
 the stem are filled with alcohol in which a glass index is placed : when 
 ihe temperature falls, the cohesion of the end of the alcohol is sufficient 
 to draw the index back with it towards the bulb ; but when the tem- 
 perature rises again, the alcohol passes the index and leaves the extremity 
 -furthest from the bulb at the lowest temperature reached. The end of the 
 
 Fig. 61. 
 
 column furthest from the bulb should always agree within about half a 
 degree with that of an accurate mercurial thermometer hung by its side. 
 I make this reservation as to 0°-5 because spirit thermometers, being slug- 
 gish, differ from mercurial ones when rapid changes are in progress. This 
 thermometer does not require a magnet to set it ; its usual position is nearly 
 horizontal ; if anything, the bulb end slightly lower than the other. To set 
 it, unhang it and raise the bulb, the index will then of its own weight slide 
 down to the end of the column. Two faults occur with this thermometer : 
 sometimes, but rarely, bubbles of air appear in the column and fix the index ; 
 more frequently error arises from the distillation of some of the alcohol, and 
 its condensation at the top of the tube. This is generally visible without 
 difficulty, but is not obvious, because if the alcohol in the stem be, as is 
 usual, coloured, that which condenses at the top is frequently quite colour- 
 less. At one time opticians freqviently buried this portion of the tube under 
 the mounting, but that practice has fortunately been abandoned. Both these 
 faults are usually easily cured by the observers themselves, and both by the 
 same process. Hold the thermometer firmly near the bulb, and bulb down- 
 wards ; then swing it rapidly with the right hand, taking care, of course, to 
 hit nothing ; the centrifugal force will usually cause a broken column to 
 unite, and will throw any alcohol from the top of the tube. After so swing- 
 ing the thermometer, it should be stood bulb downwards for an hour so as to 
 drain, and it will be well afterwards to compare it with a mercurial one to 
 see that all is correct. The index will very probably be thrown into the 
 
 VOL. I. M 
 
162 HYGIENE 
 
 bulb by this swinging, but a very little gentle coaxing will bring it out again.. 
 Sometimes, if the tube be very fine and the amount of condensed spirit very 
 small, it has not momentum enough to move from the top ; it can then be 
 displaced only by evaporation, and a match or a small spirit lamp should be 
 applied to the tube where the condensed spirit is lodged. Of course care 
 must be taken not to apply heat so suddenly as to crack the tube. 
 
 PHILLIPS'S MAXIMUM THERMOMETER 
 
 This thermometer, invented by Professor J. Phillips, F.R.S., as early as 
 1832, and described by him in the ' Eeport of the British Association ' for 
 that year, was remarkably slow in becoming known. How it was, and why 
 it was, that twenty years after its invention the Royal Observatory was still 
 employing the very bad maximum invented by Rutherford, is one of the 
 facts which it is difficult to explain. It was probably partly Professor 
 Phillips's w^ell-known modesty, and partly that no optician had a pecuniary 
 interest in pushing it. Possibly the very slight use made of the invention 
 in this country led to its being unknown to, or ignored by, M. Walferdin,. 
 who described an identical arrangement to the Academic des Sciences, 
 April 24, 1854, as his own. To the same cause must probably be attributed 
 the following curiously incorrect statement by M. Eenou : ^ — ' Depuis 
 quelques annees les Anglais ont adopte ce thermometre qu'ils appellent 
 
 Fig. 62. 
 
 thermometre h maximum de Phillips, mais h tort, I'invention appartient 
 bien positivement a M. Walferdin.' Reference to the ' British Association 
 Report ' settles the question of priority by twenty-two years in favour of 
 Phillips, though very likely the invention by M. Walferdin was genuine. 
 On the Continent this pattern is generally described not by either name but 
 as 'thermometre a bulle d'air.' Its construction is shown by fig. 62 ; it is 
 very simple and easily understood. In the manufacture a very small bubble 
 of air is introduced into the tube, separatmg 10° or 15° at the extremity 
 from the remainder of the column. In the pattern represented by fig. 62, 
 and which is that used for meteorological purposes, this detached portion 
 ■will be seen to be many degrees away from the top of the column, but that 
 is merely for the convenience of illustrating the principle. Assume that the 
 thermometer is found as per fig. 62, it then shows that since the instrument 
 was last set, the temperature had at some time reached 70°'8. To set the 
 thermometer it should be taken off the hooks and the bulb end lowered 
 until the detached portion runs back and nearly joins the top of the column 
 (with some thermometers even a slight shake may be necessary), then re- 
 hang it nearly horizontal, bulb end slightly lowest ; it will then show the 
 existing temperature, and when any increase occurs the detached portion 
 will be pushed along, its extremity furthest from the bulb marking the 
 highest temperature reached ; if the temperature fall, this detached portion 
 is left behind and thus registers the maximum. 
 
 ' Armimire Soe. Met. dc France, t. xxiv. p. 61. 
 
METEOBOLOGY 
 
 16S 
 
 If the index-column be short, this form of thermometer can be used in 
 any position, vertical or horizontal, bulb up or bulb down, and I have 
 myself used it in a well 1,000 feet deep, where it had to bear the jolts of 
 raising and lowering by a windlass ; the only difference is, that with such a 
 short index a sharp swing is necessary to reset it. 
 
 As thermometers on this principle can be made with extremely fine 
 bores it has been very largely adopted for clinical thermometers ; in fact, it 
 was used in the very first made for Dr. Aitken by Mr. Casella, and since 
 that time probably 100,000 have been made upon that model. 
 
 NEGKETTI AND ZAMBEA'S MAXIMUM 
 
 While Phillips's maximum was lying dormant, if not forgotten, the 
 Great Exhibition of 1851 was opened, and the jury who had to deal with 
 meteorological instruments, having nothing before them except specimens of 
 Six's and of Rutherford's thermometers, and, strangely enough, apparently 
 not knowing of Phillips's maximum, pointed out that a trustworthy maximum 
 was much wanted. Messrs. Negretti and Zambra were determined to meet 
 this want, and in little more than a year brought out their excellent patent 
 maximum which is shown in fig. 63. Like Phillips's, it is (for meteorological 
 purposes) used in a nearly horizontal position — the bulb slightly lower than 
 the top. Its construction is as follows : — First an ordinary thermometer 
 
 Fig. 63. 
 
 tube (rather large) is prepared ; then a thread of glass about one-fourth of 
 an inch long is dropped down to near the bulb end, and the stem at that 
 point and the contained fibre are heated to softness and slightly bent. This 
 fixes the fibre and forms an obstruction in the tube, which tube is sub- 
 sequently filled with mercury as an ordinary thermometer. When in use, if 
 the temperature rises, the mercury in the bulb expands and forces its way 
 past the obstruction ; but if the temperature falls, the molecular attraction of 
 the mercury is insufficient to induce the column to pass the obstruction, and 
 therefore the full length remains in the tube, and the 
 extremity shows the highest temperature reached. The 
 thermometer is reset by lowering the bulb end and, if 
 necessary, giving the thermometer a swing, bulb down- 
 wards. 
 
 IMMISCH'S THEEMOMETEES 
 
 These are extremely small, accurate, and handy 
 thermometers which, as fig. 64 shows, are quite unlike 
 an ordinary thermometer. They owe their indication 
 to the expansion of a liquid in a small tube, bent 
 nearly to a circle, which tends to straighten with in- „ 
 
 crease of heat ; this motion is, by very fine mechanism, 
 
 made to cause the hand to travel over the dial. It is quite usual for these 
 little thermometers to be true to less than 0°*1 F. Some are graduated for 
 
 u2 
 
164 
 
 HYGIENE 
 
 ordinary use, some for the limited range required for clinical purposes. ]\rr. 
 Immisch has recently added an arrangement which makes them virtually 
 registering. 
 
 RICHARD'S RECORDING THERMORIETER 
 
 Until lately the cost of recording thermometers was so great {101. or 801.) 
 as to prevent their adoption at any but richly endowed observatories ; but 
 within the last few years MM. Eichard Freres of Paris have perfected the 
 pattern shown in fig. 65, and sell them at so low a price as to render the 
 instrument generally accessible ; it therefore claims a few words here. The 
 bulb, like Immisch's, is a curved, flattened tube filled with a hquid, but as it 
 has more work to do it is enormously larger. The changes in the curvature 
 of the tube cause the long lever to rise with increase of temperature and to 
 fall with decrease. This marks on a cylinder on exactly the same system 
 as the barograph already described. When duly wound up and started it 
 
 I 
 
 Fig, 
 
 can be locked up and left untouched until the corresponding hour in the 
 following week, when a record, true, probably, to 0°-5 F., will be found for 
 every instant during the week. As the curvature of the tube or the strength 
 of the spring \nl\ sometimes alter, the reading of an accurate mercurial 
 thermjDmeter should be noted when a new sheet is put on, so that, if neces- 
 sary, the position of the lever may be adjusted to correspond with it. 
 
 HYGROMETRY 
 
 This branch of meteorology is not in a satisfactory state. Quite two 
 hundred forms of hygrometer have been devised, but, except in rare cases 
 and for experimental purposes, only two survive, viz. the dry and wet bulb 
 (sometimes erroneously called Mason's) hygrometer, and Saussure's hair hygro- 
 meter. The dry and wet bulb is almost the only form used in the British 
 Isles and in our Colonies, and it is the more usual on the Continent, but as 
 frosts are more intense at Continental stations than at British ones, and the 
 
METEOBOLOQY 
 
 165 
 
 wet bulb thermometer requires great care and attention in time of frost, it is 
 usual on the Continent to have also a Saussure hair hygrometer and to fall 
 back upon it in frosty weather. 
 
 Dry and Wet Bulb 
 
 The general form of the dry and wet bulb hygrometer is shown in fig. 66. 
 It is an easy instrument to read, and, provided that it be supplied with rain 
 or distilled water and with clean muslin and wick, requires no attention 
 except in frosty weather ; then it has to be visited about half an hour before 
 the regular time of observation, and the muslin brushed over with a camel- 
 hair brush dipped in cold water ; this will freeze before the time of the 
 regular observation, and the reading of the ice-covered bulb will give as 
 correct an indication of the numidity of the air as does the bulb when wet. 
 
 Perhaps some very elementary remarks upon the use of this instrument 
 may be excused, for, common as it is, there 
 are many who do not know the principle 
 upon which it is based, nor,. e.g., what is 
 the temperature of evaporation, or what 
 its relation to the temperature of the dew 
 point. It would be out of place to give 
 here a treatise on hygrometry ; we give 
 only some fragments. 
 
 The dry and wet bulb thermometer in- 
 dicate the amount of moisture present in 
 the air by the difference between the read- 
 ing of the two thermometers : the dry bulb 
 gives the temperature of the air, the wet 
 bulb gives a temperature lower than that of 
 the air, in proportion to the rapidity with 
 which the water is removed from the wet 
 bulb by evaporation. To take a homely 
 illustration, when one's head is too hot, 
 one applies eau de Cologne, because the 
 rapid evaporation of the spirit will quickly 
 cool the skin ; so does the water cool the 
 wet bulb thermometer. Moreover, the drier 
 the air, the faster does the evaporation pro- 
 ceed, and, therefore, the greater the cooling ; 
 
 hence, roughly, the greater the depression of the wet bulb below the dry, the 
 drier the air — we have said roughly, because the value of a depression of 
 (say) 6° is much greater at low than at high temperatures. 
 
 For anything like intelligent use of a dry and wet bulb thermometer a 
 set of tables is indispensable ; those generally used in this country were com- 
 piled many years since by Mr. J. Glaisher, F.E.S., but analogous ones have 
 since been prepared in many countries. 
 
 It remains for us to point out the meaning of the term ' dew-point 
 temperature : ' it is that temperature at which the air will deposit the moisture 
 contained in it. This can be ascertained directly by Dines's hygrometer (see 
 p. 166) or by calculation from the reading of the dry and wet bulb thermo- 
 meter. Very roughly it may be said to be about as much below the wet 
 bulb reading as the wet bulb itself is below the dry. 
 
 In a perfectly saturated atmosphere the two thermometers should read 
 alike. Sometimes the wet bulb wiU read a few tenths higher than the dry 
 
166 
 
 HYGIENE 
 
 bulb ; this not infrequently leads hasty persons to the conclusion that one of 
 the thermometers must be wong. This does not follow : first, because 
 when the air is saturated the dry bulb is almost always coated with a thin 
 film of water, is, in fact, a better wet bulb than the one covered with mushn ; 
 and, secondly, because the proper wet bulb is by its covering of muslin pro- 
 tected from radiation, and so kept slightly warmer than the air. 
 
 The depression of the wet bulb below the dry 
 bulb, which, as just explained, in a wet fog is 
 nil, may, in rare cases, even in England, exceed 
 20° ; but the average difference ranges from 1° or 
 2° in winter to G^ or 8° in summer. 
 
 Saussuee's Hygkometeb 
 
 One form of Saussure's hygrometer is shown in 
 ^ fig. 67. It is not an independent instrument, but 
 
 ^^_ has to be set to correspond with the value as 
 1^ computed from a dry and wet bulb thermometer. 
 
 It depends upon the fact that a human hair elon- 
 gates by moisture and contracts by dryness. A 
 hair (a) is therefore (after proper treatment as to 
 grease, &c.) fastened at one end (&), while the other 
 has a slight weight id) attached to keep it 
 stretched, and is fastened to a lever so that its 
 movements may be magnified and easily read upon 
 the scale. The total motive power of the hair 
 Fic g7 being very small, the friction of the axle becomes a 
 
 serious element, and I have seen a form of the 
 instrument in which there was no friction. The hair was fixed at its upper 
 extremity, the tension was provided by a small weight tied to the bottom of 
 the hair, which hung in the centre of a pierced tube, the lower part of which 
 was of ground glass with divisions etched upon it ; the reading was by a 
 microscope so arranged that it and the bottom of the weight could be brought 
 
 exactly opposite the scale and the 
 length then read off. 
 
 DiNEs's Hygrometer 
 
 This is the simplest form of 
 condensation hygrometer, of which 
 the earlier types were the hygro- 
 meters of Daniell, Eegnault, Al- 
 luard, and others. Dines's is dis- 
 tinguished from all the others in 
 that it only requires ether when 
 the dew point is at or below 32° ; 
 at all higher temperatures cold 
 water is alone required. One form 
 of it, which well illustrates its 
 prmciple, is shown in perspective and section in fig. 68. The vessel A is 
 filled with cold water (ice being added if required), which passes over the 
 thermometer bulb, and at the same time against the under surface of the 
 very thin sheet of glass at E. The observer watches for the deposition of 
 dew on the glass, and the thermometer at that instant gives, without any 
 calculation, the dew-point temperature. 
 
 Fig. '68. 
 
METEOROLOGY 
 
 107 
 
 RAINFALL 
 
 This subject has on account of its great engineering importance received 
 much attention, and there are now few countries in the world without special 
 organisations for its registration. As the 
 natural result thereof, considerable ap- 
 proach has been made towards uniformity 
 in the pattern of rain gauge and in the 
 mode of registration. It used (fifty years 
 since) to be not unusual to put rain 
 gauges on roofs (I suppose that they 
 might be the nearer to where the rain 
 came from), but long before that it had 
 been shown (but forgotten) that gauges 
 on elevated buildings collect much less 
 than those near the ground.^ In the 
 British Isles, in India, Ceylon, Canada, 
 and in nearly all our Colonies, the gauges 
 are one foot above ground. On the con- 
 tinent of Europe, in Algeria, Java, and 
 Sumatra, they are generally from three 
 to five feet above the ground, and there- 
 fore record about three per cent, less 
 than they would do if at one foot. In 
 the United States, owing to the Signal 
 Office stations being mostly in the heart of cities, a great many of the rain 
 gauges are understood to be on house tops. No satisfactory discussion of 
 American rainfall can be based on such observations. 
 
 The pattern of gauge generally used in this country is shown in fig. 69 ; 
 this represents one five inches in diameter, but there are also many eight- 
 inch ones at work, and those established in France by the Association 
 JFrancaise of about eight and a half inches diameter are very similar in pattern. 
 The vertical portion of the funnel, i.e. that above the cone, is known as a 
 Snowdon rim (from having in England been adopted first for gauges intended 
 for use near Snowdon), and is intended to secure the accurate ineasurement 
 of slight falls of snow. Having entered the funnel, the rain passes down 
 through a tube, made long and narrow to check evaporation, into the bottle, 
 where it remains until measurement. If the fall be exceptionally great, or 
 if a sudden frost sets in, freezes the water, and cracks the bottle, the record 
 is not spoiled, for the water is saved by the can, and may be measured almost 
 as well as if nothing had happened. The measuring jar is di^dded propor- 
 tionally to the area of the gauge, the diameter of which should always be an 
 exact dimension, 5*00 inches or 8*00 inches, as it is then easy, if the original 
 measuring jar is broken, to obtain a new one precisely adapted to the fimnel. 
 The principle of graduation is so obvious as scarcely to need mention. Take 
 a 5-inch gauge ; if the diameter be 5 inches the area is 19'64 inches, therefore 
 a rainfall of an inch, i.e. 1 inch deep over the whole of a parish or town, 
 would in this rain gauge deposit 19"64 cubic inches, or 4958 grains of water. 
 It is found in practice most convenient to make the jar hold half an inch. 
 Therefore 2479 grains are poured in and the jar is marked wath a hne repre- 
 senting 0'50 inch or \ inch ; subdivisions are similarly marked, and so finally 
 
 ' This deficiency has been proved to be due to the wind blowing the rain over, and out 
 
 of, the funnels of gauges in exposed positions. 
 
168 HYGIENE 
 
 the jar lias fifty di\dsions, one for eacb i-J-ytli of an inch, and is figured at 
 •10, '20, -30, •10, and "50. As regards the general manner of observing and 
 recording rainfall, it seems best to reprint in extenso the rules drawn up for 
 the use of British observers. 
 
 Suggestions for Securing Uniformity of Practice among Eaixfall Observers 
 
 1. Site. — A rain gauge should not be set on a roof, a slope, or a terrace, but on a level 
 piece of ground, at a distance from shrubs, trees, walls, and buildings— at the very least 
 as many feet from tlieir base as they are in height. Tall-growing flowers, vegetables, and 
 bushes must be kept away from the gauge. If a thoroughly clear site cannot be obtained,, 
 shelter is most endurable from NW., N., and E., less so from S., S.E., andW., and not at 
 all from S.W. orUE. 
 
 2. Old Gauges. — Old-established gauges should not be moved, nor their registration 
 discontinued until, at least, two years after a new one has been in operation, otherwise 
 the continuity of the register will be irreparably destroyed. Both the old and the new 
 ones must be registered at the same time, and the results recorded for comparison. 
 
 3. Level and Fixing. — The funnel of a rain gauge must be set quite level, and so 
 firmly fixed that it will remain so in spite of any gale of wind or ordinary circumstance.. 
 Its correctness in this respect should be tested from time to time. 
 
 4. Height. — The funnels of gauges newly placed should be 1 ft. above grass. Information, 
 respecting height above sea-level may be obtained from the Editor of ' British Eainfall.' 
 
 5. Rnst. — If the funnel of a japanned gauge becomes so oxidised as to retain the rain 
 in its pores, or threatens to become rusty, it should have a coat of gas tar, or japan black, 
 or a fresh funnel of zinc or copper should be provided. 
 
 (3. Float Gauges. — If the measuring rod is detached from the float, it should never be 
 left in the gauge. If it is attached to the float, it should be pegged or tied down, and only 
 allowed to rise to its proper position at the time of reading. To allow for the weight of 
 the float and rod, these gauges are generally so constructed as to show only when a 
 small amount of water is left in them. Care must always be taken to set the rod to the 
 zero or 0. 
 
 7. Can and Bottle Gauges. — The measuring glass should always be held upright, or 
 l^laced on a level slab ; the reading is to be taken midway between the two apparent 
 surfaces of the water. 
 
 8. Tivie of Reading. — 9 a.m. daily ; if taken only monthly, then 9 a.m. on the 1st. 
 
 9. Date of Entry. — The amount measured at 9 a.m. on any day is to be set against the 
 previous one ; because the amount registered at 9 a.m. of, say, the 17th contains the fall 
 during 15 hours of the 16th, and only 9 hours of the 17tli. 
 
 10. Mode of Entry. — If less than one-tenth (-10) has fallen, the cypher must aliuays 
 be prefixed ; thus, if the measure is full up to the seventh line, it must be entered as •07,. 
 that is, no inches, no tenths, and seven hundredths. There must always be two figures 
 to the right of the decimal point. Even in the case of one-tenth of an inch (usually 
 written -1) a cypher must be added, making it •lO. Neglect of this rule causes much 
 inconvenience. All columns should be cast tivice — once up and once down, so as to avoid 
 the same error being made twice. Never copy a total, always cast the column afresh. 
 When there is no rain, a line should be drawn rather than cyphers inserted. 
 
 11. Caution. — The amount should always be written down before the water is thrown 
 away. 
 
 12. Small Quantities. — The unit of measurement being -01, observers whose gauges 
 are sufiiciently delicate to show less than that, are, if the amount is under -005, to throw 
 it away ; if it is '005 to -010 inclusive, they are to enter it as •01. 
 
 13. Absence. — Every observer should train some one as an assistant ; but where thiS' 
 is not possible, instructions should be given that the gauge be emptied at 9 a.m. on the 
 1st of the month, and the water bottled, labelled, and tightly corked, to await the observer's 
 return. 
 
 14. Heavy Rains. — When very heavy rains occur, it is desirable to measure imme- 
 diately on their termination, and it will be found a safe plan after measuring to return the 
 water to the gauge, so that the morning registration will not be interfered with. Of course 
 if there is the slightest doubt as to the gauge holding all that falls, it must be emptied,, 
 the amount being previously wi-itten down and added to the subsequent measurement. 
 
 15. Snow. — In snow three methods may be adopted — it is well to try them all. 
 (1) Melt what is caught in the funnel by adding to the snow a previously ascertained 
 quantity of warm water, and then, deducting this quantity from the total measurement, 
 enter the residue as rain. (2) Select a place where the snow has not drifted, invert the- 
 
METEOBOLOGY IGO 
 
 funnel, and, turning it round, lift and melt what is enclosed. (3) Measure with a rule the 
 average depth of snow, and take one-twelfth as the e(iuivalent of water. This being a 
 very rough method, is not to be adopted if it can be avoided. Some observers use in 
 snowy weather a cylinder of the same diameter as the rain gauge, and of considerable 
 depth. If the wind is rough, all the snow is blown out of a flat-funnelled rain gauge. 
 Snowdon pattern gauges are much the best. 
 
 16. Overflow. — Not a year passes in which some gauges are not allowed to overflow ; it 
 is therefore necessary to call attention to the fact that there does not seem to be any part 
 of the British Isles where 4 inches may not fall in 24 hours. It is not desirable to purchase 
 any gauge of which the capacity is less than 6 inches. 
 
 17. Second Gauges. — It is desirable that observers should have two gauges, and that 
 one of them should be capable of holding 8 inches of rain. One of the gauges should be 
 registered daily, the other weekly or monthly as preferred, but always on the 1st of each 
 month. By this means a thorough check is kept on accidental errors in the entries, which 
 is not the case if both are read daily. Observers having two gauges and recording both 
 daily, should keep the records distinct, and forward a copy of each. Never take a mean 
 of two. 
 
 18. Deiu and Fog. — Small amounts of water are at times deposited in rain gauges by 
 fog and dew ; they should be added to the amount of rainfall, because (1) they ' tend to 
 water the earth and nourish the streams ; ' and not for that reason only, but (2) because 
 in many cases the rain gauges can only be visited monthly, and it would then obviously 
 be impossible to separate the yield of snow, rain, &c. ; therefore, for the sake of uniformity, 
 all must be taken together, and as, except by watching all night, it is never possible to be 
 certain that small amounts are wholly dew, it is best to count all entries of "01 in or 
 upwards as days with rain. 
 
 19. Dotibtful Entries. — Whenever there is the least doubt respecting the accuracy of 
 any observation, the entry should be marked with a ?, and the reason stated for its being 
 placed there. 
 
 20. Breakage. — The Editor has no desire to supply rain gauges or glasses, or in any 
 way to undertake, or interfere with, that which is the business of opticians ; but the 
 continuity and permanent accuracy of the records of his correspondents is to him of such 
 importance, that he deems it advisable to announce that any assistance in his power is 
 always at their service. 
 
 21. Leakage.- Ohseryers should test their gauges occasionally to see that the amount 
 collected is neither increased nor decreased by leakage. 
 
 THEEMOMETEE SCREENS 
 
 During the last lialf century it has been increasingly recognised that it 
 is useless to have accurate thermometers, and to aim at comparing climates, 
 unless the thermometers are placed under similar conditions at the two or 
 more localities which it is desired to compare. The first, in order of date, 
 of the special screens designed for this purpose was erected about 1841 at 
 the Eoyal Observatory, Greenwich ; it is generally known as 
 
 Glaisher's Stand 
 
 It consists of one horizontal, one vertical, and two sloping boards. It is 
 made so that it can be turned round, and thus the face on which the thermo- 
 meters hang kept away from the sun, and with three thicknesses of wood 
 and two layers of air between the sun's rays and the thermometers. This 
 pattern is, in order to secure continuity of record, still retained at Greenwich 
 and at some other stations. It was formerly general at the stations of the 
 British Meteorological Society and at those established by the Eoyal 
 Engineers, but is now rare, as, though a great advance upon anything up- 
 to the date of its construction, it is found to have the following disad- 
 vantages, {a) It does not prevent rain and snow falling on the ther- 
 mometers, (b) the turning two or three times a day is troublesome, and if 
 forgotten the thermometers may be exposed to the direct rays of the suji, 
 
170 
 
 HYGIENE 
 
 (c) the thermometers are warmed by radiation from the ground and neigh- 
 bouring objects, unless surrounded by quite a large space of grass. 
 
 Stevenson's Screen 
 
 I cannot trace the precise history of this pattern. In an address to the 
 Meteorological Society of Scotland, delivered January 14, 1857, by Dr. Stark, 
 F.R.S.E., the secretary, there is the following paragraph : — • 
 
 The Committee have had long and earnest discussions relative to the mode of exposing 
 the instruments to the weather. It is quite apparent that, if we wish comparable results, 
 the instruments must be similarly exposed ; and the Committee have, meanwhile, recom- 
 mended that the instruments should be exposed in a box, with double open lonvre-boarded 
 sides, 1^ inch being between the sides, with a sloping roof to carry off the rain, and 
 raised 4 feet from the ground. To suit instruments of all sizes it is convenient to have 
 the inner box about 18 inches in internal width by 14 inches in depth and 8 inches in 
 breadth ; and it may either be fixed in an open spot over grass, or, if a low window with a 
 northern exposure can be had, it may be fixed in front of it, and the side next the window 
 may be made single, and to open downwards, so that, when opened, the door would rest on 
 the window sill. 
 
 It is a pity that this description was not accompanied by an engraving ; 
 and it is to be noted that Mr. Thomas Stevenson, C.E., who eventually 
 brought out the Stevenson Screen, was a member of the committee in 
 whose name Dr. Stark was speaking. 
 
 Three years later (March 29, 1860) the Council state that boxes have 
 been erected at most of the Society's stations, but that they are not uniform, 
 
 that there is considerable difference of opinion 
 as to the best form, that experiments were to be 
 instituted by the secretary to ascertain the best 
 pattern, and that the Council hoped to publish 
 the results in the next report. I cannot trace 
 auy record of these experiments, or of their 
 result. In fact, the subject seems to have slum- 
 bered until June 1864, when in a paper in the 
 Journal of the Scottish Meteorological Society 
 Mr. Stevenson gave a description and sketch of 
 the stand almost precisely as it is still made. 
 Fig. 70 gives a representation of it, which leaves 
 only one point needing mention — namely, that 
 the Venetians are double, falling both inside and 
 outside, and with half an inch between them at 
 their highest points. They are on one frame cut 
 herring-bone-wise, which not only saves cost, but 
 also bulk, and the hollow between the two sets 
 causes nearly all rain to drop through instead of 
 running up one slope and down the other, and 
 being thence blown on to the thermometers. 
 This is not a perfect stand suitable for all cli- 
 mates ; no such stand has been devised, but the 
 Stevenson certainly seems well adapted for this country, and is rapidly sup- 
 planting all others. 
 
 MoNTSouKis Theemometee Stand 
 
 Fig. 71 represents the pattern of stand generally used in France. The 
 southern sun is shut off by the double roof A, morning and evening sun by 
 the wings B C. As already stated, thermometers in France are not mounted 
 
METEOROLOGY 
 
 111 
 
 on slabs as in England, but the maximum and minimum can be seen hanging 
 at a and h, while other instruments are placed at d and e. It will be noticed 
 that the stand is approached by several steps, rendered necessary by the fact 
 that in that country the ther- 
 mometers are usually 8 or 9 
 feet above the ground, instead 
 of 4 feet as in England. 
 
 I have dealt rather fully 
 with the previous instruments 
 because they are the funda- 
 mental ones for all climatic 
 work, and the very fact that 
 I have done so will enable me 
 to dispose of some of the 
 other instruments very briefly. 
 
 SUNSHINE 
 
 Although means of re- 
 cording approximately the 
 duration of sunshine were 
 devised more than thirty 
 years since, the instrument 
 has only lately been brought 
 into a compact and handy 
 form, therefore the general 
 use of sunshine recorders is 
 
 much more recent. At present (owing chiefly, it is stated, to the cost of procur- 
 ing and grinding good glass spheres) sunshine recorders are rather expensive. 
 
 but, partly perhaps from their novelty, their adoption is becoming fi-equent. 
 There are many patterns ; one available for the tropics, or indeed for any 
 
172 
 
 HYGIENE 
 
 latitude, is shown in fig. 72, p. 171. The principle is very simple ; whenever 
 the sun shines brightly, its rays, focussed by the sphere, fall on a strip of 
 cardboard and burn a hole ; as the world turns round, if the sun continue to 
 shine, the hole is elongated and becomes a slit, which if no clouds intervene 
 will continue till nearly sunset. The length charred is theiefore a distinct 
 measure of the duration of sunshine. 
 
 Another arrangement for obtaining analogous records, is by placing sensi- 
 tised photographic paper in the box shown in fig. 73. The sun shines in 
 through a tiny hole, and while shining acts on the paper, the photographic 
 trace on wliich is fixed by wasliing in clean water, and the record can then 
 be read off.^ 
 
 To distinguish between the two methods it has been proposed to call the 
 photographic one swnligJit records, and the burnt ones snushine records. 
 
 SOLAE EaDIATION 
 
 To determine the heating power of the sun's rays appears at first sight 
 
 Fig. 73. 
 extremely easy ; put a maximum thermometer in the sunshine and you have 
 it at once. Oh no, very far from it. If your thermometer be clean and 
 bright, the mercury in it will act as a spherical mirror, and instead of absorb- 
 ing the sun's heat rays will reflect them. Then make the bulb of blaok 
 glass ; still the vitreous surface will act as a partial reflector. Then coat it 
 with lampblack; still two evils— (a) the first shower will wash it off; 
 (b) unless part of the stem be blackened as well as the bulb, the cold stem 
 will chill the bulb. Blacken both thermometer and part of stem, and put it 
 inside a glass jacket, pump out as much air as you can, and having done so 
 seal the tube hermetically. Those are the reasons for, and the stages by 
 which the black bulb in fig. 75 was arrived at. But we are still far from 
 obtaining the true heat of the sun's rays. Putting the thermometer into the 
 vacuum jacket not only protects it from rain but largely from another very 
 important influence — wind. Evidently the reading of a naked black bulb 
 thermometer is intermediate between that produced by the sun and that of 
 
 ' Fig. 74 represents a form of this intended for any latitude. 
 
METEOBOLOGY 
 
 173 
 
 the air in contact with it ; the stronger the wind the more rapidly will fresh 
 particles of air impinge upon the thermometer bulb and the lower will it 
 read. Even the jacket does not wholly abolish this evil, because tlie wind 
 cools the glass jacket, and the jacket and the bulb interchange heat by radia- 
 tion, and therefore part of the influence of wind remains. Then there is 
 another difficulty. Suppose that on two consecutive 
 days the black bulb in vacuo read 128°, but that 
 the temperature of the air on the first day was 
 70°, on the second 80° ; one sees at once that 
 the sun's rays must have been more powerful on 
 the first day than on the second, because on the 
 first they raised the black bulb 68° above the air 
 temperature, and on the second only 48°. At 
 present the best plan is to have two thermometers 
 as nearly identical as possible, except that the bulb 
 and part of the stem of one is coated with lamp- 
 black, and the other is left bright ; both are in 
 vacuum jackets, both on one post, pointed in the 
 same direction (preferably to S.E.) and both four 
 feet above grass, and to consider as the amount of 
 solar radiation the excess (in degrees) of the black 
 bulls above the bright bulb thermometer. 
 
 Tereestrial Eadiation 
 
 Everybody does not know, what is however 
 quite true, that, as a rule, a grass plot is consider- Fig. 75. 
 
 ably colder than a flower bed or a gravel walk, and 
 
 that all are considerably colder than the air three or four feet above them. 
 This cooling is due to the rapidity with which (when there are no clouds) 
 grass radiates heat into space. The amount of terrestrial radiation is therefore 
 
 Fig. 76. 
 
 nearly proportional to the absence of cloud. It is determined by placing 
 Casella's modification of Eutherford's minimum thermometer (fig. 76) on a 
 grass plot, and noting the difference between its reading and that of the 
 minimum in the Stevenson screen. 
 
 Earth Temperature 
 
 The broad general features of earth temperature are, that at depths 
 of a few inches the temperature does not differ very widely from that of 
 the air, but as the depth increases the amphtude of the daily and seasonal 
 changes decreases, and the latter also suffer retardation, so that at two 
 or three feet the minimum, instead of occurring in the beginning of 
 January, falls late in February, and the maximum, instead of July 16, falls 
 late in August, and the maximum is so much lov/er and the minimum so 
 much higher that the range there is less than half what it is at the surface. 
 
174 
 
 HYGIENE 
 
 -v-H" 
 
 At ten feet the retardation amounts to nearly three months, and the range is 
 reduced to about 8°-0, and at 25 feet the range is only about 3°, and the 
 minimum is retarded until June and the maximum till December, so that 
 probably at about 35 feet, where the range is reduced to 1°, the maximum 
 occurs at the date of greatest winter cold and the minimum at that of 
 maximum summer heat. 
 
 The observation of earth temperature was formerly difficult and the ther- 
 mometers themselves were extremely delicate and costly, as the old plan was to 
 have a long and fine bore tube with a large bulb, and 
 bury all but the upper portion in a pit, leaving the 
 scale at the top visible, so that the thermometer could 
 be read. Anyone can realise the difficulty and danger 
 of breakage attending the construction, transport, 
 and fixing of a thermometer 25 feet long, with a 
 heavy bulb at the end of it. The modern plan (fig. 
 77) is to close the bottom of a piece of stout iron tube, 
 to drive it or bary it in the ground to the desired 
 depth, and to lower into it, by a cham, a slow-action 
 thermometer (i.e. one with a large bulb and coated 
 with non-conducting material so that its indications 
 will not change while being raised), which is hauled 
 up by the chain whenever a reading has to be taken. 
 In short ones, like fig. 77, the thermometer is let 
 into a stick attached to the covering cap. Another 
 immense advantage of the new plan is that the ther- 
 mometer can be verified whenever desired. The old 
 thermometers, once placed, could not be raised, and 
 their errors were never known. 
 
 WIND 
 
 DiBECTION 
 
 As regards direction it is questionable whether 
 for sanitary and hygienic purposes any apparatus is 
 needed ; there is no vane so sensitive and true as 
 the smoke from a chimney, and when an observer has once fixed accurately 
 the precise position of his meridian, nothing else is required but care and 
 common sense. 
 
 It may be well to mention the very easiest way of finding the meridian, 
 at any place where true local time is known. The sun is due south at noon 
 or within a minute thereof during the following periods : 
 
 April 11th to 18th. 
 
 June 9th to 18th. 
 
 August 28th to September 3rd. 
 
 December 22nd to 25th. 
 
 If, therefore, a pole be erected vertically as tested by a plumb line, the 
 shadow from it will fall true N.W. at 9 a.m., N. at noon, and N.E. at 3 p.m. 
 The (in all other respects) very advantageous spread of uniform time, e.g. 
 Greenwich time, throughout England and Wales, and Paris time through- 
 out France, has led to local time being lost sight of. It can always be 
 obtained from uniform time by correcting for longitude as in the following 
 case. 
 
 Fig. 77. 
 
METEOBOLOGY 
 
 175 
 
 What is the local time at Bath when it is 9 a.m. Greenwich time ? 
 Eeference to any map will show that Bath is 2° 20' W. of Greenwich. 
 Degrees and seconds of longitude multiphed by 4 give minutes and seconds 
 of time. 
 
 Then 2° 20' 
 
 4 
 
 9m. 20s. ; 
 and as Bath is W. of Greenwich, local time there is earlier than at Green - 
 • wich, therefore at Bath 9.0 Greenwich time corresponds to 8h. 50m. 40s. 
 local' time. In other words, on the dates above set out, the sun at Bath is 
 due south at Oh. 9m. 20s. Greenwich time. 
 
 It may be thought that it is easier to lay down the true cardmal pomts 
 by the Pole star, which can be seen any starlight night, and which is never 
 very far away from true N., but I do not think so. Others may say why not 
 do it by a compass, allowing for variation. If the observer is sure that he 
 knows the variation, if he duly allows for it and does not apply it 
 with the wrong sign, well and 
 good; but these hints are not 
 written for experts (had they 
 been, I should have suggested 
 the method of equal altitudes), 
 but merely to point out to be- 
 ginners the path which contains 
 the fewest pitfalls. 
 
 The motion of clouds is by 
 no means to be ignored, but it 
 will be found that only the very 
 lowest can be taken as indicating 
 surface wind. The motion of 
 high clouds is, however, inter- 
 esting, and at times indicates 
 that to which the surface wind 
 will gradually shift. 
 
 FoKCE OK Velocity of Wind 
 
 This is a rather difficult sub- 
 ject, and one at present in a state 
 of confusion. It is generally 
 stated that what is known as 
 the Eobinson's cup anemometer 
 was first made known in 1850 
 by a paper published in the 
 
 Trans.Boy.Irish Acad, in 1855; but this is not correct, as the Report of 
 the British Association, 1846, part 2, p. Ill, shows that (1) the original 
 suggestion was not Robinson's, but Edgeworth's ; and (2) that the instru- 
 ment was at work in 1846, four years before the above paper was written. 
 That, however, is merely the correction of a little bit of false history. 
 
 Eobinson's anemometers, being those by far most generally used, claim a 
 few words of description and comment. Fig. 78 shows the simplest form. 
 From whatever direction the wind may blow it will meet the hollow face of 
 two cups and the rounded face of two others ; it will exert more force upon 
 the former than upon the latter, and therefore it will cause the whole four to 
 rotate ; and the stronger the wind the faster will be the rotation. On the 
 
17G HYGIENE 
 
 shaft which carries these four arms there is au endless screw which works 
 in teeth cut in the circumference of the dials, and so (by arrangements, into 
 the detail of which I need not enter) the hands indicate on the dial the number 
 of miles of wind which have passed since the previous reading. The funda- 
 mental principle upon which these instruments are graduated, is that the 
 cups move with one-third of the velocity of the wind — i.e. that if the centres 
 of the cups are 1*12 feet apart each revolution would correspond to 3*52 feet 
 of motion, and (if the factor be really 3) to 10-56 feet of wind, then 
 (10-50 X 500=5280 ft.=l mile) 500 rotations would indicate the passage of 
 one mile of wind. 
 
 I said that this subject is in a state of confusion ; it is so for this reason, 
 that it has been proved that the factor is not 3, but something between 
 2 and 3, probably about 2^. This may appear a small matter, but it is 
 not; its effect is that all wind velocities are reported greater than they 
 really are — a wind of 50 miles an hour is called one of 60 miles an hour, 
 and so on. Besides this fundamental error there are others, such as the 
 retardation due to friction, which varies with the velocity ; at very low 
 velocities, two or three miles an hour, the friction is so nearly equal to the 
 wind force that many anemometers stand still ; but, on the other hand, 
 when the wind gets to, say, fifty miles an hour and the cups have to make 
 seven complete rotations in each second of time, friction becomes relatively 
 unimportant. And it is not merely legitimate friction from which ane- 
 mometers suffer. I have seen the anemometer on an observatory (where 
 there was no lack of money) coated with a sticky compound of soot and oil 
 quite half an inch thick — that was not fair play. I have photographs of the 
 anemometers at several mountain observatories quite unrecognisable under 
 their mantle of hoar frost. Evidently the indications of instruments in such 
 circumstances are not worth the paper upon which they are recorded — still 
 less are they worth reducing and publishing. 
 
 Another great difficulty with anemometers is that of finding a suitable 
 position for them. No one can be found to approve the existing practice of 
 meteorologists with respect to anemometry, and yet hardly any one has the 
 courage to insist on a new departure. Almost universally in this country 
 and on the Continent the anemometer is mounted on the highest part of the 
 observatory, with no regard to what height it may be above the ground, nor 
 to the shape of the building. Now it is well known and obvious that air 
 currents are retarded by friction, and that therefore the greater the height 
 above the ground the greater the freedom with which the wind moves, and 
 therefore the greater its velocity. And it is equally obvious that if a wind 
 current meets a building, it cannot go through it, and must therefore pass it 
 either laterally or over the top ; hence it is that the wind at some feet above 
 the top of the building is generally greater than that of the true air current 
 at that level. 
 
 The foregoing remarks, while probably useful historically, are also designed 
 to act as warnings to those who may think that if they go to a good optician 
 for a Eobinson's anemometer and then fix it in position, they will ex neces- 
 sitate have an accurate record of the velocity of the wind. Besides the false 
 factor (I believe no one has yet abandoned the 3 to 1), they must see that it 
 is in a thoroughly open position, not less than ten feet above ground, with 
 no buildings near it, and that it is kept scrupulously clean and frequently 
 suppHed with fresh oil. 
 
 Occasionally the wind's force is reported in lbs. per square foot : tliis is 
 sometimes obtained from a pressure anemometer (of which the best known 
 is Osier's) and sometimes computed from the recorded velocity on the assump- 
 
Beaufort Scale 
 
 Description 
 
 
 
 Calm 
 
 1 
 
 Light air 
 
 2 
 
 Light breeze 
 
 3 
 
 Gentle breeze 
 
 4 
 
 Moderate breeze 
 
 5 
 
 Fresh breeze 
 
 6 
 
 Strong breeze 
 
 7 
 
 Moderate gale 
 
 8 • 
 
 Fresh gale 
 
 9 
 
 Strong gale 
 
 10 
 
 Whole gale 
 
 11 
 
 Storm 
 
 12 
 
 Hurricane 
 
 METEOEOLOGY 177 
 
 tion that the square root of 200 times the pressure m pounds equals the 
 velocity in miles per hour — i.e. 
 
 \/200P = V, or conversely, V^ x '005 = P. 
 
 But this factor of 200 is as doubtful as that of 3 for the ratio of Robinson's 
 cups. 
 
 There are many tables given for roughly estimating the force of the wind, 
 but they differ greatly. I think that the following, given by Mr. R. H. Scott, 
 F.R.S., in his Instructions, is the best, but possibly the velocities may be 
 considered too great when the 3 is finally replaced by 2-5 or whatever is the 
 best value. The 90 miles might then come down to 75. 
 
 Velocity in miles per hour 
 3 
 8 
 13 
 18 
 23 
 28 
 34 
 40 
 48 
 56 
 65 
 75 
 90 
 
 AMOUNT OF CLOUD 
 
 It has not yet become the practice to record this except by estimation, 
 but it is surprising with what accuracy these estimates are made. As a rule 
 observers ignore from the horizon up to about 20"^, and confine their estimate 
 to the zenith and 70° from it towards the horizon. This space is supposed 
 to be divided into 10 parts ; if there is not a trace of cloud, the amount is ; 
 if there are equal amounts of blue sky and of cloud, 5 ; if entirely overcast, 
 10. It is not so easy to determine the amount after dark, but an observer 
 soon learns the constellations, and uses the absent stars as evidence of present 
 cloud. 
 
 FOEMS OF CLOUD 
 
 This is one of the branches of meteorology in a transitional state. At 
 the beginning of this century Luke Howard, F.R.S., who has been well 
 called the Father of English meteorology, wrote an essay upon the subject, 
 proposed a nomenclature and submitted a series of descriptions of clouds, 
 which, in spite of the enormous advances in other branches of meteorology, 
 still hold the first rank. Even photography has not yet helped very much, 
 because it of course has the difficulty of producing similar effects by white 
 clouds and their blue background. Much has been, and is being, done, 
 especially in Sweden, France, and England, and various alterations of 
 Howard's classification have been suggested, but not one of the new pro- 
 posals has met with general adoption, and therefore I quote only Howard's, 
 and in his own words. 
 
 CiBEUs {mares' tails — the loftiest cloud; Mr. Glaisher, F.R.S., when 
 five or six miles high, in Coxwell's balloon, saw cirri far above him). — Parallel, 
 flexuous, or diverging fibres, extensible by increase in any or in all direc- 
 tions. 
 
 VOL. I. N 
 
178 HYGIENE 
 
 CiKRO-cuMULus {mackcvol shj). — Small, well-defined roundish masses 
 in close horizontal arrangement or contact. 
 
 CiEEO-STKATUs. — Horizontal or slightly inclined masses, attenuated 
 towards a part or the whole of their circumference, hent downward or undu- 
 lated ; separate or in groups consisting of small clouds havmg these characters. 
 
 The foregoing are the clouds chiefly prevalent at great heights ; the 
 following are usually lower. 
 
 Steatus (ground-fog). — A widely extended continuous horizontal sheet, 
 increasing from below upward. 
 
 Cumulus (mountain-like clouds, often toith a silver lining). Convex or 
 conical heaps; increasing upward from a horizontal base. 
 
 CuMULO-STEATus. — The cirro-stratus blended with the cumulus, and 
 either appearing intermixed with the heaps of the latter, or superadding a 
 wide-spread structure to its base. 
 
 Nimbus. — The rain cloud. A cloud or system of clouds from which rain 
 is falling. It is a horizontal sheet, above which the cirrus spreads, while the 
 cumulus enters it laterally and from beneath. 
 
 MISCELLANEOUS PHENOMENA 
 
 Under this head I purpose giving merely a few hints respecting pheno- 
 mena, which mostly can be observed without instruments, or at any rate 
 without those usually regarded as meteorological ones. 
 
 Snow. — In sharp frost the patterns of snow crystals are frequently of 
 exquisite beauty. The best way to see them is to expose slabs of coloured 
 glass ; when these become cold, and the air is below 32°, crystals will remain 
 unchanged for hours, and if care be taken not to breathe upon them, they 
 can be examined and drawn with perfect ease. Directly the temperature 
 rises all their beauty vanishes. Their size varies, but is generally from ;i^th 
 to T^ths of an inch in diameter. 
 
 Hail. — This varies much ; probably according to the conditions of its 
 formation ; sometimes it is so soft as to resemble a soft snowball ; sometimes 
 it is very hard crystalline ice ; sometimes the stones are formed of alternate 
 layers of clear and opaque ice. When the hail is very soft, it is frequently 
 pyramidal in shape, and not infrequently radial (like iron pyrites) in its 
 texture and cauliflower-like at its base, giving in short the idea of a ball 
 which had split up into segments. There was a wonderful fall of this kind 
 in and near London at 3.15 p.m., March 8, 1857. Mr. Glaisher observed and 
 photographed some of the stones at Greenwich, and I examined those which 
 fell near Buckingham Palace ; at these widely- separated places the fall was 
 very similar, the stones (only happily they were very soft) being about one 
 inch long and | inch in diameter at their base. Howard reports a some- 
 what similar fall, but of stones or rather snow pyramids of little more than 
 half the above dimensions. Pyramidal soft hail is common, but I have never 
 seen or heard of any case like that of 1857. When exceptional hailstorms 
 occur, prompt attention should be given to weighing accurately some of the 
 largest stones that can be found. Accurate weight is the most essential 
 feature, next to that shape and size, then structure, whether clear or opaque, 
 number of alternate layers, &c. Then evidence should be collected illus- 
 trative of the force of fall ; this is partly afforded by the greatest thickness 
 of glass broken, by the indentation of zmc or corrugated iron roofing, by 
 damage to plants, poultry, &c. It used to be stated that hail never fell at 
 night ; this is not now asserted, but it is so much more rare by night than by 
 day that nocturnal hail-falls should always be fully reported. 
 
METEOBOLOGY 17^ 
 
 Thunderstorms.— Full instructions upon observing thunderstorms and 
 lightning having been issued by the Koyal Meteorological Society, it is not 
 necessary to dwell at length upon the subject. Briefly it comes to this— 
 note the time of first thunder, most thunder, and last thunder, and similarly 
 of hghtning— notice the shortest time interval, i.e. the interval between 
 seeing the hghtning and hearing the thunder belonging to that flash— roughly, 
 each five seconds' interval corresponds to a distance of a mile. If any object 
 is struck, collect as full details as practicable. As regards human beings 
 killed by hghtning there is much to be learned, for the marks on, and 
 changes in, the body vary immensely— whether they depend on the intensity 
 of the shock, on the state of the skin as to perspiration (I believe that not 
 infrequently vapour saves a man's life— it acts as a conductor— is so electri- 
 fied that it strips the man of his clothes, but it keeps the charge outside his 
 body, and so saves his life). This question of perspiration is very important, 
 because at present there is no evidence whether the vapour is converted into 
 high-pressure steam by heat, or whether the water particles are repelled by 
 becoming similarly electrified. I think that the latter is the more probable, 
 but the observed fact is that persons whose feet are hot generally have their 
 boots burst open and flung from their feet, while they personally suffer Httle 
 hurt. Evidence as to the thickest piece of metal fused by hghtning is very 
 much wanted. 
 
 Ozone. — Thirty years ago no meteorological station was considered to be 
 properly equipped without a box of ozone test papers — strips of foolscap paper 
 dipped in iodide of potassium and starch. During the cholera epidemics of 
 1849 and 1854, great attention was given to the subject, and I personally 
 think that it is a pity that the observations were given up. It is true that the 
 papers were not uniform, that distinguished chemists scorned the plan, and 
 that Dr. Fox wrote a large and handsome book which killed the old method, 
 but did not, I believe, induce a single observer to adopt the new one which 
 he recommended. I do not for a moment enter the lists with either Dr. Fox 
 or any other chemist ; very possibly the discoloration of the test papers was 
 not due to ozone at all. I admit all that, but I will report very briefly what I 
 did in 1856 or 1857, and leave it to the reader to say whether or not it is pro- 
 bable that perseverance in the direction then commenced might not have 
 been rewarded by progress in sanitary work. I cut up a set of ozone papers 
 so that portions of one small strip were simultaneously exposed at several 
 stations, two in the heart of London and Westminster respectively, and the 
 other four or five were exposed in the suburbs. A month's papers were sent 
 out at once all ready dated ; at the end of the month all came back to me. 
 Except from smoke, there was not a single day on which the papers exposed 
 in town were discoloured. The suburban ones varied, but according to a 
 regular law the papers in the S.W. suburbs showed ozone, or rather I would 
 say discoloration, with wind from S.W., but when the wind was N. or E. and 
 had to pass over the metropolis there was no discoloration ; and so all round. 
 Winds from the country coloured the papers, wind which had passed over the 
 metropolis never did. 
 
 Fog. — This is one of the meteorological phenomena hitherto neglected ; 
 it is entered in the registers, and sometimes the word dense is added, but that 
 is all. It seems to me imperative that there should be some scale of intensity 
 adopted for fog, just as there is for amount of cloud. Six years since, I 
 wrote a strong plea for the establishment of fog gauges,^ and suggested the 
 erection of a slab painted as per. fig. 79, p. 180, No. 1 to be :^ inch broad and 
 the higher numbers, \, 1, 2, and 4 inches respectively, the scale to be 20 ft. 
 
 ' Symons's Meteorological Magazine, xvii. 17. 
 
 n2 
 
1 2 
 
 5 
 
 4 
 
 5 
 
 1 
 
 1 
 
 1 
 
 ■ 
 
 NU 
 
 
 
 ^/^ 
 
 180 HYGIENE 
 
 from the observer, and the amount of fog recorded to be that of the thinnest 
 line which could be seen. I do not suggest that the plan is perfect, but 
 regret that no better has been proposed, and that to my knowledge only one 
 
 observer has adopted it. 
 We shall certainly not 
 learn anything satisfac- 
 torily respecting fog dis- 
 tribution until some such 
 scheme is adopted. 
 
 Optical Phenomena. 
 — There is much for the 
 meteorologist to do under 
 this head, but as no one 
 could at present prove the relation between, say, aurora and public health, it, 
 and such other subjects as haloes, coronas, luminous meteors, the three 
 varieties of the rainbow, &c., must pass without notice here, the reader being 
 referred to the short list of useful books at the end of this article if he 
 desires to pursue the subject. 
 
 Verification of Instruments 
 
 It is always best to insist upon instruments being accompanied by a 
 certificate of verification, the cost of which (except for barometers) rarely 
 exceeds half-a-crown. 
 
 OBSEEVATION HOUES 
 
 These vary in different countries ; in the British Isles the hours are almost 
 without exception 9 a.m. and 9 p.m. at the first and second order stations, 
 and 9 a.m. alone at the climatological and rainfall stations. As regards tem- 
 perature, it is a curious fact that any homonymous hours such as 3 a.m. and 
 3 p.Bi., 4 A.M. and 4 p.m., 5 a.m. and 5 p.m., give an average which does not 
 differ widely from the mean of the whole twenty-four hours, and the same 
 is nearly true of the mean of the maximum and minimum temperatures in a 
 Stevenson screen. On the Continent, where people rise earlier, 7 a.m. is very 
 usually the time of the first observation, followed by another about 1 p.m. and 
 a third about 8 p.m., but there is much less uniformity than there is in the 
 British Isles. 
 
 Making the Observations 
 
 Many hints upon this subject have already been given ; it only remains to 
 add a few general ones. In the first place never ' cook ' an observation ; it is 
 much better to leave a blank, and to give in the margin any information 
 from which you think that you could 'cook' the missing record. The 
 ' cooking,' if it has to be done at all, can be done best at the central office, 
 where other records are available for comparison. 
 
 When reading thermometers look quite horizontally at them, otherwise you 
 will read them too high or too low. Take care that you can look comfortably 
 at all parts of the scale of your dry and wet bulb instruments ; if they are at 
 all too high, provide a stool or step. Observations not made comfortably are 
 rarely made well. 
 
 Be punctual ; do not imagine that five minutes after time is of no conse- 
 quence, or you will let the five grow to ten and the ten to fifteen, and then 
 your unpunctuality will cause more harm than the index error of your 
 instruments. 
 
METEOROLOGY 181 
 
 Always train at least one other person to observe ; otherwise, if you are 
 absent or ill, your record will be interrupted, and broken records are of 
 little use. 
 
 The Entry of the Observations 
 
 This differs so much according to circumstances, that few general rules 
 can be laid down. There is, however, one often neglected, but which ex- 
 perience shows to be necessary ; it is that the observations should never be 
 taken on a scrap of paper, an envelope, or a slate, i.e. never on anything 
 which is not to be preserved. If observations are worth making, they are 
 worth preserving ; and, however much an observer may intend to faithfully 
 ■copy the figures into his permanent register, he may lose the scrap of paper, 
 smudge the slate, or make a mistake in copying. Memorandum-books are 
 so cheap that there can be no reason why the original entries should not be 
 neatly entered in pencil in readiness for copying in ink, and then in any 
 doubtful case the original pencil entry can be produced. 
 
 The forms of record employed by different societies, institutions, and 
 countries differ so considerably, but are all of them so clearly arranged, that 
 no further explanation seems needed than that on the forms themselves. 
 
 The Publication of Observations 
 
 This also is a subject upon which there is little to say, because it depends 
 so much on the object with which the publication is to be made. I, however, 
 offer one suggestion, viz. that in many tables too much prominence is given 
 to hygrometric calculations of doubtful value, and too little to daily and 
 monthly ranges of temperature. I by no means advise the exclusion of the 
 dew-point temperature, or the amount of humidity ; but, knowing that the 
 foundation (the theory of the wet-bulb thermometer) is doubtful, I think that 
 space can be employed to greater advantage than by devoting columns to 
 * elastic force of vapour,' ' weight of vapour in a cubic foot of air,' ' additional 
 weight of vapour required to saturate a cubic foot of air,' and ' weight in grains 
 of a cubic foot of air.' 
 
 Lastly, I would urge that, wherever possible, values should be given not 
 only in figures but represented by curves and diagrams. 
 
 SOME USEFUL BOOKS UPON METEOROLOGY 
 
 (I purposely make this heading as vague as possible because every list of 
 the kind must necessarily be imperfect. Where a subject has a literature of 
 many thousand volumes, no two persons would pick out the same fifty as 
 the best ; nay more, the same person would probably not twice select the 
 same fifty. It would have been both more easy and more pleasant to make 
 it longer, but anything beyond a very short list would be quite out of place. 
 The title is given in English for all those works of which English translations 
 exist. Where translations are known, the language in which they can also be 
 obtained is indicated by a prefixed letter. F= French ; G= German ; S= 
 Swedish). 
 
 Instructions and Tables 
 
 Abercromby, Hon, E. : Instructions for observing Clouds (with photographs). London, 
 
 1888. 
 Blanford.H. F., FJl.S. : Instructions to Meteorological Observers in India. Calcutta, 
 
 1876. 
 
182 HYGIENE 
 
 Denza, F. : Istruzioni per le osservazioni meteorologiche e per 1' altimetria baroma- 
 
 trica (2 parts). Torino, 1883. 
 Glaisher, J., F.E.S. : Hygrometrical Tables. 6th ed. Loudon. 
 Guyot, A. : Tables, Meteorological and Physical. 4th ed. Washington, 1884. 
 Hann, J. : Jelinek's Anleitung zur Ausfiihrung met. Beob. New edition in two parts- 
 
 Wien, 1884. 
 Hazen, H.A. : Handbook of Meteorological Tables. Washington, 1888. 
 Jelinek, C. : Anleitung zur Anstellung meteorologischer Beobachtungen. 3rd ed- 
 
 Wien, 1876. 
 Kingston, G. T. : Instructions to Observers connected with the Meteorological Service 
 
 of the Dominion of Canada. Toronto, 1878. 
 Marriott, W. : Hints to Meteorological Observers. 2nd ed. London, 1887. 
 Mascart, E. : Instructions Met^orologiquea. 2nd ed, Paris, 1881. 
 Poey, A. : Comment on observe les Nuages. 3rd ed. Paris, 1879. 
 Scott, R. H., F.E.S. : Instructions in the use of Meteorological Instruments. London,. 
 
 1875. 
 Symons, G. J., F.E.S. : Pocket Meteorological Tables. Short and simple rules for 
 
 accurately determining altitudes barometrically, with sundry useful tables. 4th ed. 
 
 London, 1890. 
 
 General Treatises 
 
 Abbe, C. : Treatise on Meteorological Apparatus and Methods. (This forms Part II. 
 
 of the Eeport of the Chief Signal Officer U.S.A. for 1887.) Washington, 1888. 
 Abercromby, Hon. E. Weather. London, 1887. 
 
 „ ,, Principles of Forecasting by means of Weather Charts.. 
 
 London, 1885. 
 Bebber, W. J. van : Handbuch der ausiibenden Witterungskunde. Stuttgart, 1885. 
 S. Buchan, A : Handy Book of Meteorology. 2nd ed. Edinburgh, 1868. 
 „ Introductory Text Book of Meteorology. Edinburgh, 1871. 
 
 Capron, J. E. : Auroras, their Characters and Spectra. London, 1879. 
 Daniell, J. F., F.E.S. : Elements of Meteorology. 2 vols. London, 1845. 
 G. Dove, H. W. : Law of Storms. 2nd ed. : translated by E. H. Scott. London, 1862. 
 Drew, J. : Practical Meteorology. 2nd ed. London, 1860. 
 
 F. FitzEoy, Admiral, F.E.S. : The Weather Book. London, 1863. 
 
 G. Foissac, P. : De I'lnfluence des Climats sur I'Homme. Paris, 1867. 
 Fox, C. B., M.D. : Ozone. London, 1873. 
 
 GuiUemin, A. : La M6teorologie. Paris, 1885. 
 
 Hann, J. : Handbuch der Klimatologie. Stuttgart, 1883. 
 
 Herschel, Sir J. F. W., F.E.S. : Meteorology. 2nd ed. London, 1862. 
 
 Kaemtz, L. F. : Lehrbuch der Meteorologie. (3 vols.) Halle, 1831. 
 F.G. „ ,, Complete Course of Meteorology. (Translated by C. V. Walker,. 
 
 F.E.S.) London, 1845. 
 
 Lemstrom, S. : L'Aurore Bor^ale. Paris, 1886. 
 
 Mascart, E. : La Meteorologie appliqu6e a la Provision du Temps. Paris, 1881. 
 G. Modern Meteorology — Six Lectures by Mann, Laughton, Strachan, Ley, Symons, and 
 
 Scott. London, 1879. 
 F. Mohn, H. : Grundziige der Meteorologie. 2nd ed. Berlin, 1879. 
 
 Schmid, E. E. : Lehrbuch der Meteorologie. Leipzig, 1860. 
 F. Scott, E. H., F.E.S. : Elementary Meteorology. 4th ed. London, 1887. 
 
 „ Weather Charts and Storm Warnings. 3rd ed. London, 1887. 
 
 Sprung, A. : Lehrbuch der Meteorologie. Hamburg, 1885. 
 
 Thomson, D. P. : Introduction to Meteorology. London, 1849, 
 
 Umlauft, F. : Das Luftmeer. Wien, 1891. 
 
METEOBOLOGY 183 
 
 Periodicals 
 
 American Meteorological Journal. (Monthly.) Ann Arbor, U.S.A., 1884-91, 
 Annuaire de la Soci6t6 M6t6orologique de France. (Monthly.) Paris, 1849-91. 
 Annuaire de I'Observatoire de Montsouris. (Annually.) Paris, 1872-91. 
 Annuaire de I'Observatoire Eoyal de Bruxelles. (Annually.) Bruxelles, 18.3.3-91 
 BoUettino mensuale dell' Osservatorio Centrale del E. Coll. Carlo Alberto in Moncalieri 
 
 (Monthly.) Torino, 1880-91. 
 Ciel et Terre. (Fortnightly.) Bruxelles, 1881-91. 
 Das Wetter. (Monthly.) Magdeburg, 1884-91. 
 
 Journal of the Scottish Meteorological Society. (Originally quarterly, now annually. 
 
 Edinburgh, 1863-91. 
 Quarterly Journal of the Eoyal Meteorological Society. London, 1872-91. 
 Symons, G. J. : British Eainfall. (Annually.) London, 1861-91. 
 Symons's Monthly Meteorological Magazine. London, 1866-91. 
 Wild, H. : Eepertorium fur Meteorologie. (Variable.) St. Petersburg, 1870-90. 
 Zeitschrift fiir Meteorologie. (Monthly.) Wien, 1866-91. 
 
INFLUENCE OF CLIMATE ON HEALTH 
 
 BY 
 
 C. THEODOEE WILLIAMS, 
 
 M.A., M.D. (OxoN.), F.E.C.P. 
 
CLIMATE 
 
 The influence of climate on health is a very important subject, and often 
 constitutes a difficult problem for governments and sanitary authorities to 
 solve in regard to colonisation, to sites of towns, and to the disposition of 
 troops. It is well known that thousands of lives have been sacrificed to 
 ignorance, on the part of those in authority, of the climatic peculiarities of 
 the regions to which settlers or troops have been sent, while on the other 
 hand military surgeons possessed of climatic information have been able by 
 due precautions to preserve armies in comparative health and vigour, even 
 under the strain of fatigue and privation, and in pernicious climes. 
 
 The connection of race and climate is an exceedingly intimate one, and 
 we can hardly doubt that many of the divisions of the human family owe 
 their principal characteristics to the influence of different climates acting 
 through successive generations ; for instance, in the Caucasian variety we 
 see the influence of climate well exemplified in the contrast between the 
 natives of Europe and of India ; in the Mongolian variety, between the 
 Chinese and the Esquimaux ; or again in the difference between the negroes 
 of various parts of Africa, and lastly we may even detect some trace of this 
 influence if we compare Englishmen with their cousins in our colonies, and 
 in the United States of America, 
 
 The influence of climate on the individual depends largely on whether he 
 be native or imported from another region, and while in some localities 
 emigration, as in Australia, is attended with no evil results, and the emigrat- 
 ing race even gains in numbers and strength, in other cases it is not so, and 
 the emigrant race dwindles and disappears under the new conditions. 
 
 In our great dependency India, which has been ruled so long and so 
 judiciously by Great Britain, it is stated that the pure race, if not inter- 
 mingled with the native, does not last beyond the third generation, and there 
 are other tropical climates, such as those of the West Coast of Africa and the 
 West Indies, that appear to have a particularly deleterious and fatal effect 
 on the Anglo-Saxon race, and have earned the name of the White Man's 
 Grave. In these regions the natives and especially negroes survive, and 
 sometimes flourish, but it is a mistake to conclude that they are miinfluenced 
 by the climate which is so fatal to Europeans ; as a matter of fact they do suffer, 
 but in other ways. At the Cape of Good Hope Hottentot soldiers suffered from 
 pulmonarydisorders more than white soldiers. At Sierra Leone black regiments 
 furnished a larger quota of chest disease than white ones in the ratio of 6*4 : 4-9 
 per 1,000 ^ (Boudin). In Jamaica too the Army j\Iedical Eeport for 1859 states 
 that while not a single white soldier was admitted for tuberculous disease, the 
 deaths from phthisis among the negro troops stood at 8*67 per 1,000 of the 
 whole strength. Negroes seem to be especially prone to phthisis, and when, 
 transplanted to a temperate climate, to develope it rapidly, for the Army 
 Medical Eeports also show that negro troops when moved from Sierra Leone 
 to Gibraltar, a healthy station for white troops, developed a phthisis mor- 
 tality of 43 per 1,000 in place of 6*4 at Sierra Leone. 
 
 * Walshe, Diseases of Lungs. 4th edition. 
 
188 HYGIENE 
 
 In temperate climates the Anglo-Saxon flourislies and spreads in all 
 directions, as the vast and increasing populations of North America and 
 Australia testify. 
 
 It was truly remarked by the late Professor Parkes that much of the 
 mortality of Europeans in tropical climates was due, not to the climate alone, 
 but to the climate phis certain other agencies, such as impure water, improper 
 food, bad drainage, and various kinds of excess, and that, if these causes be 
 removed, the mortality of Europeans, or lather of European troops, in the 
 tropics does not differ so greatly from the mortality of troops at home. 
 
 The wonderful improvement in the health of troops in India and tropical 
 countries has doubtless been due to a more complete enforcement of military 
 hygiene. However, after making fair deduction for the effect of errors of 
 life, there remains a certain proportion of disease, by no means a small one, 
 occurring among persons of well-regulated life, which can only be attributed 
 to the effects of chmate. Before entering more fully on this subject, we will 
 consider the various elements of climate and the influence that each indi- 
 vidually exercises on the human body ; and then we shall be in a better posi- 
 tion to determine the exact part that climate plays in the causation of disease. 
 
 Climate is derived from the Greek KXt/xa (kAiVw, I bend), a slope, signifying 
 the curvature of the earth from the equator to the pole, and indicating' 
 various qualities of the atmosphere which surrounds us, such as its density, 
 its temperature and sunlight, its moisture and rainfall, its winds and elec- 
 tricity, and all the factors which more or less influence the human frame. 
 
 TEMPEKATUEE 
 
 The human body appears capable of enduring great extremes of tempera- 
 ture, and of maintaining its standard of 98° to 99° F. under the most oppo- 
 site climatic conditions. 
 
 It has been shown that inhabitants of temperate climates like Great 
 Britain can endure both extremes of cold and heat without danger if they 
 adopt certain precautions, and provided the atmosphere be still and dry. 
 
 The degree of cold which Arctic voyagers have sustained without injury is 
 very astonishing. Captain Parry noted the thermometer as low as — 55° F. 
 or 87° below the freezing point, Sir John Franklin at — 58° F. or 90° below 
 the fi-eezing point, and Sir George Back at — 70° F. or 102° below the 
 freezing point. 
 
 Sir John Eichardson ^ states that in his last Arctic expedition he was 
 accustomed to go from his sitting-room at a temperature of 50° F. to his 
 magnetic observatory at a short distance from it, without feeling it necessary 
 even to put on a great coat, though the temperature of the external air was 
 — 50°, and the difference between the two atmospheres 100° F. He attributed 
 this absence from chilling influence to the dryness and stillness of the air. 
 The writer, when visiting the Engadine in the winter, has often exposed 
 himself to night air, when the thermometer was — 4° F., without catching 
 cold, and both at Davos and St. Moritz it is the custom for pulmonary invalids 
 to sleep with open windows all through the winter, apparently with impunity 
 and even benefit, though in the winter the night minimum is sometimes 
 below — 11° F. This would be impossible if there were much wind. 
 
 If the exposure to cold be prolonged, and the circulation and thermogenic 
 powers cannot be maintained, the blood-vessels, and specially the smaller 
 arteries and capillaries, become contracted, and no longer permit the passage 
 
 ' Carpenter's Human Physiology. 4tli edition, p. 431. 
 
INFLUENCE OF CLIMATE ON HEALTH 189 
 
 of blood-corpuscles, and thus all physiological and chemical changes are 
 arrested. Various parts, especially the extremities, become starved, and hence 
 death of these parts takes place by frost-bite and gangrene, which show them- 
 selves generally in the toes and fingers. Prolonged exposure to extreme cold 
 gives rise to an overpowering sense of lassitude and languor, the sensibiHty 
 becomes lowered, the individual loses power of reaction and sinks to sleep, 
 often to rise no more, as is sometimes witnessed in long journeys through 
 the snow, the form of death being generally coma. In other cases the brain 
 becomes excited and the patient manifests delirium, incoherence and thick- 
 ness of speech, the symptoms resembling those of intoxication. Death may 
 occur from syncope or asphyxia, though this is less frequent than by coma. 
 
 The influence of heat on the human body, whether it be solar or arti- 
 ficial, does not, as a rule, cause any great rise in the body temperature, pro- 
 vided perspiration be free and abundant, which in old residents in the tropics 
 is generally the case. The balancing power of the human economy over its 
 temperature, through its secretions, is very wonderful, for Blagden and For- 
 dyce bore a temperature of 260° F. in an oven with only the small rise of 
 2^° F., as long as the air was dry and the perspiration free ; but if the air 
 became moist and evaporation was hindered, the temperature of the body rose 
 8°F. 
 
 The effects of the direct sun's rays will be considered later, but various 
 interesting experiments have been made on the effect of heat in shade. Dr. 
 Becher determined his own temperature in a very useful way during a voyage 
 from the Cape to India, and found that the body heat increased in the pro- 
 portion '05° F. for every increase of 1° F. in the air. Eattray, in his own 
 case, found a decided increase varying from -2° to 1°*2 F.,the maximum being 
 generally attained in the afternoon. 
 
 The effects of the direct sun's rays on the human body are, when not too 
 powerful, highly beneficial, and as we can see in the vegetable kingdom the 
 etiolated plant craning its long slender stalk, and spreading its leaves to 
 catch the welcome sunshine, and, when this is reached, exchanging for 
 transparent stems and absence of colour sturdy growth and an abundance of 
 chlorophyll, so we witness the power of the sun's rays in the contrast between 
 the pallid faces and complexions of dwellers in large cities, and the brown 
 tint and ruddy hue and vigorous appearance of the native of the country or 
 seaside. Though the intimate chemical and physiological effects of sunshine 
 on the human economy may be as yet unknown to us, we recognise its 
 healthful influence in promoting cell changes, in quickening caj)illary circu- 
 lation, in stimulating gland secretion, and fostering growth and develop- 
 ment. How different to the sensations is the atmosphere of a room where 
 the sun never shines to that of one with a southern exposure, where the 
 mote-laden sunbeams radiate into every corner and remove the dank chill 
 feeling so generally present in sunless chambers, about which the old Italian 
 proverb is only too true, that ' where the sun does not enter, the physician, 
 will.' Well has Mrs. Hemans said : 
 
 Thou art no loiterer in monarcli's hall, 
 
 A gift thou art, and a joy to all. 
 
 A bearer of hope by land and sea, 
 
 Sunbeam, what gift hath the world like thee ? 
 
 The effect of heat on the lungs is to diminish the number of respirations, 
 as Eattray showed in persons passing from a cold to a hot chmate ; there was 
 a reduction from 16'5 respirations (in England) to 13'74, and even to 12*74 
 in the tropics, accompanied, however, by a sHght spirometric increase, not 
 
190 HYGIENE 
 
 enough, however, to compensate for the diminished number of respirations, 
 and so the respiratory function is considerably reduced, the reduction 
 amoimting to at least 18-43 per cent., or, as Dr. Parkes ' puts it, ' If 10 
 omicesof carbon are expired in the temperate zone, only 8-157 ounces would 
 be expired in the tropics.' 
 
 There is also a diminution in the water exhaled. The observations of Parkes 
 and of Francis that the lungs of Europeans in India are hghter after death 
 than the European standard, confirm the explajiation given by Kattray of 
 the slight spirometric increase, compared with the lessened number of inspi- 
 rations, viz. that in the tropics there is a larger proportion of air and a 
 lessened one of blood in the lungs. Observations show that the heart's 
 action is not perceptibly quickened in the tropics, and that the pulse is not 
 faster than m temperate regions. The digestive powers are lessened, and the 
 craving for animal food diminished, and there is ample evidence of the liver 
 being first congested, and then undergoing various indurative changes con- 
 sequent on active or passive congestion of an organ. The skin is stimulated 
 to largely increased action, and there is an increase of excretion estimated at 
 24 per cent. The urine is diminished in quantity and the amount of urea 
 lessened, possibly from less animal food being consumed. The nervous 
 system is depressed, and specially so if great humidity be combined with 
 great heat. Great heat is well borne by the system if the body temperature 
 is kept down by abundant perspiration, and if the hot season be not of long 
 duration, but protracted residence in a region of great heat appears to exer- 
 cise a depressing influence, lessening the nervous activity and impairing the 
 great functions of digestion and respiration and sanguification, and the 
 power of forming new and healthy tissue. The tint of the skin and con- 
 junctivae in Europeans long resident in the tropics, and their appearance of 
 premature age, all go to confirm this conclusion. 
 
 HUMIDITY 
 
 There are few climatic factors which influence our sensations more 
 strongly than humidity. After several hot days, or after a long succession 
 of east winds, a fall of rain is followed by a pleasant refreshing condition of 
 the atmosphere, which we all appreciate. On the other hand, excessive 
 atmospheric humidity prevents free evaporation from the skin though it 
 often materially assists expectoration, and is therefore useful in many cases 
 of bronchitis. The effect of rain on the circulation may be illustrated by the 
 following : A consumptive male patient of mine was trekking in the Kala 
 Hari Desert in the Cape Colony and apparently flourishing in the open-air life. 
 The climate was exceedingly dry, a difference of 25° P. between the wet and 
 dry bulb being recorded. Heavy rain afterwards fell, the satm-ation point 
 was reached, and the patient immediately had a severe attack of haemoptysis. 
 The presence of a large amount of moisture in the air, while it promotes 
 expectoration, rather favours the continuance of coryza and catarrh. The 
 combination of moisture and heat, as is seen in the scirocco wind, is felt 
 oppressive by most people, but it is doubtful if the combination of cold and 
 moisture be not more harmful. 
 
 ' From the experiments of Lehmann on pigeons and rabbits it appears 
 that more carbonic acid is exhaled from the lungs in a very moist than in a 
 very dry atmosphere. 
 
 ' The spread of certain diseases is supposed to be intimately related to 
 humidity of air. Malarious diseases, it is said, never attain their fuUest 
 
 ' Practical Hygiene. 4th edition, p. 402. 
 
INFLUENCE OF CLIMATE ON HEALTH 191 
 
 epidemic spread unless the humidity approaches saturation. Plague and 
 small-pox are both checked by a very dry atmosphere. The cessation of 
 bubo plague in Upper Egypt, after St. John's Day, has been considered to 
 be more owing to the dryness than to the heat of the air. 
 
 ' In the dry Harmattan wind, on the West Coast of Africa, small-pox can- 
 not be inoculated ; and it is well known with what difficulty cow-pox is kept 
 up in very dry seasons in India. Yellow fever, on the other hand, seems 
 independent of moisture, or will, at any rate, prevail m a dry air.' ^ 
 
 EAINFALL 
 
 The precipitation of atmospheric moisture in the form of rain may, if not 
 excessive, exercise a beneficial influence on health, as, besides reducing the 
 amount of moisture in the atmosphere, it sweeps away various impurities 
 arising from the presence of man and animals, which would otherwise 
 accumulate, and thus rainfall considerably promotes the health of the com- 
 munity. The amount of rainfall differs in different localities enormously, 
 from almost nothing in the Sahara Desert to 493 inches at Cherraponji ^ 
 in Assam, and its precipitation seems to be determined, according to Mr. 
 Scott, in one of three ways : — 
 
 First, by the ascent of a current of damp air which, losing heat in 
 ascending, is unable to hold as much moisture in suspension as formerly. 
 
 Second, the contact of warm and damp air with the colder surface of the 
 ground, as in the case of the western coasts of Great Britain and Ireland in 
 winter, where the land is colder than the sea surface. 
 
 Third, the mixture of hot and cold masses of air, of which the influence 
 in promoting rainfall is not very considerable. 
 
 Examples of the first are to be seen where a Avarm moist wind is diverted 
 upwards by an intervening mountain range ; the current is rapidly cooled 
 in ascending and deposits its moisture in the form of rain. This is still 
 more marked if the wind comes from seaward, and in this way the S.E, 
 trade becomes a rain-bringer to the mountains of Eastern Brazil and the 
 eastern slopes of the Andes. 
 
 Owing to the prevalence of easterly winds in low latitudes, the lee sides 
 of tropical mountain ranges are often, according to Wojeikof, better wooded 
 and watered than the western, whereas in the temperate zone the reverse is 
 the case, and it is the western slopes of mountain ranges which are the best 
 clothed with vegetation and verdure. 
 
 Where trade winds blow, there is little or no rain unless they blow on to 
 a mountainous coast, and with the periodic shifting of the trade wind areas 
 the dry areas shift likewise, but the descent of the trade wind brings abundant 
 rain, and when the sun is lowest— i.e. in winter. This season of winter 
 rain occurs in the sub-tropical region, extending from latitudes 30° to 40° in 
 both hemispheres, embracing countries bordering the Mediterranean, with 
 Asia Minor and the western part of Persia and Oregon and CaHfornia in 
 North America, as well as in the southern hemisphere, the Cape Colony, 
 South- West AustraHa, and the northern island of New Zealand. Exceptions 
 to this rule are certain districts where summer rains prevail instead of 
 winter— as the Eastern States of the Union, the Argentine Piepublic, China, 
 and Natal, which benefit largely in an agricultural point of view from rain- 
 fall when most needed, whereas the other countries are liable to summer 
 
 1 Parkes's Practical Hygiene. 
 
 2 Eliot, in the Quarterly Joimial of the Meteorological Society, 1882, states 40 inches 
 fell in one day at this place. 
 
192 HYGIENE 
 
 drouglits. North of the sub-tropical region is the region of rain at all 
 seasons, to which Great Britain and Ireland belong, the rainfall depending 
 on the somewhat irregular succession of barometrical depressions and anti- 
 cyclones which are constantly mo%'hig over the earth's surface in the. tem- 
 perate zone. The rule about this region is that the western coasts of the 
 continents have autumn rains gradually passing into summer rains as we 
 advance into the interior of the country. According to Dr. Haian, in Europe 
 the Alps divide the region of summer rains from that of the autumn rains of 
 Southern Europe. In North-West France 24 per cent, of the annual fall 
 occurs in summer, and in Central Prussia 38 per cent. In these islands the 
 wettest month on the west coast is January, and the second wettest is 
 October, but the difierence between the months is by no means great, and 
 the London monthly rainfall, as calculated by Mr. Scott and Mr. Dines 
 from observations of sixty years, gives October as the wettest month, but 
 shows the difference between this and February, the driest one, to be only 
 2-74 inches against 1'50 inches. The annual rainfall in different parts of 
 Great Britain varies greatly, being on the east coast 18 to 23 inches, but on 
 the west from 30 to 130 inches ; the largest amount of rainfall in one day regis- 
 tered in Great Britain was 5 inches, which fell in Monmouthshire in twenty- 
 four hours on July 14, 1875. 
 
 The regions of the globe where most rain falls are certain districts in the 
 equatorial regions of calms, and localities where damp winds meet the moun- 
 tain ranges and are thus diverted upwards ; on the leeward side of these 
 ranges there is usually a dry tract. Examples of localities with large rainfalls 
 are the Khasia Hills in Assam, with Cherraponji ; the Western Ghauts, with 
 Mahabuleshwur, the Western coasts of the British Isles, of Norway and 
 North-West America or Southern Chili, and of New Zealand with Hokitika. 
 
 On the other hand, the driest regions in the world are those stretching 
 eastward from the Great Sahara Desert through Arabia to Persia ; the 
 Great Salt Lake region in North America ; the interior of Australia and the 
 Desert of Gobi in Chinese Tartary, and the rainless tract of Peru and Chili 
 between the Andes and the sea. These two last owe their dryness to their 
 being leeward of mountains which have caused the precipitation of any 
 moisture contained in winds passing over them. 
 
 Elevation has been sliOAvn to exercise some influence over rainfall, and 
 the amount of rain collected increases with the height above the sea, but it 
 has been demonstrated that in India the maximum fall occurs at an eleva- 
 tion of about 4,000 feet, being the level at which the south-west monsoon 
 is cooled just below its dew point. Mahabuleshwur and Cherraponji are about 
 that level ; above, the air appears too cold to contain much vapour. 
 
 Hann finds that in the Austrian Alps and in parts of Central Europe, 
 the maximum of rainfall in winter occurs at an elevation of 3,000 to 4,000 
 feet, but that in summer this level is above the highest peaks. 
 
 In the British Isles there appears to be no rule of increase of rainfall 
 with elevation : and on the western coasts, especially the Lake District and 
 that of Glencoe in Scotland, which appear to be the wettest regions, more 
 eeems to depend on the trend of the valleys or on their confluence, than on 
 their elevation. 
 
 BAROMETBIC PEESSURE 
 
 The ordinary varieties of barometric pressure at the sea-level have not 
 been shown to mfluence health considerably, except when combined with 
 other meteorological elements such as those of temperature and moisture, 
 
INFLUENCE OF CLIMATE ON HEALTH 193 
 
 but when the barometric pressure is lessened to the extent of several inches. 
 as in balloon voyages, or in mountain ascents, or when it is largely increased 
 as in descents in diving-bells, or pneumatic tubes in use for the construction 
 of piers and bridges, such change exercises considerable influence on the 
 circulatory and respiratory system of man. 
 
 Diminution of barometric pressure is accompanied by decrease of mois- 
 ture and by increased power of the sun's rays from the greater diathermancy 
 of the atmosphere — i.e. the increased facility by which the sun's rays are 
 transmitted through attenuated air. According to Dr. Denison this causes 
 an increased difference between the sun and shade temperatures of 1° F. for 
 every rise of 235 feet, and consequently the extremes of temperature are 
 much greater than at sea-level, and the atmosphere is drier and more 
 aseptic, being shown, in some instances, to be devoid of germs. The great 
 heat on mountain sides covered with snow when the sun shines is explained 
 by the before-mentioned diathermancy. 
 
 Let us now first consider the effect of diminished barometric pressure 
 due to rarefaction of the atmosphere as we ascend mountains. The baro- 
 meter which stands at 30 inches at sea-level with appropriate corrections 
 gives at 5,000 feet a reading of 25 inches and one of 20'5 at 10,000 feet, thus 
 showing a fall of 5 and of 9'5 inches respectively, and these are the degrees 
 of diminution of pressure which are made use of for purposes of medical 
 treatment. 
 
 Nevertheless in the Andes people live and flourish at far greater heights. 
 La Paz, the capital of Bolivia, a city of from 70,000 to 80,000 inhabitants, 
 is situated 13,500 feet above sea-level, showing that man is capable of sus- 
 taining without injury considerable diminution of barometric pressure. 
 
 The effect of extreme and sudden diminution of pressure was seen during 
 Glaisher and Coxwell's balloon ascent, when the reduction to 9| inches pres- 
 sure showed an elevation of 29,000 feet, when Mr. Glaisher lost consciousness 
 though the balloon mounted yet higher, and Mr. Coxwell believed he noted a 
 reading of only 7 inches before the descent commenced, which would indicate 
 a height of 37,000 feet ! However, we cannot tell for certain whether Mr. 
 Glaisher's loss of consciousness was due to the cold or to the altitude, but 
 probably from the presence of lividity it was due to the latter. Li M. 
 Tissandier's ascent with MM. Sivel and Croce-Spinelli in the ' Zenith ' from 
 Paris in 1875, a height of 8,600 metres (28,155 feet) was reached too rapidly, 
 followed by a descent between 6,000 and 7,000 feet, and then a second ascent ta 
 nearly the same height, the result being that all the observers were overcome 
 and lost all power of movement and consciousness, and two died apparently 
 from want of oxygen, presenting cyanosed countenances, with eyes sunk, and 
 mouths open and full of clotted blood, M. Tissandier reaching the ground in 
 an almost unconscious condition. He graphically describes the gradual loss 
 of power in the higher regions, which precluded his using the oxygen inhala- 
 tions with which he was furnished. The fatal results were attributed not to 
 the altitude but to the rapidity of the ascent, before the lungs could accustom 
 themselves to the altitude — to the long exposure at a great height, and to 
 the inabnity of the aeronauts to inhale the oxygen gas from sheer loss of 
 power, precluding them even grasping the tubes of the inhalers. 
 
 The physiological effects of diminished barometric pressure indicate that 
 for elevations not exceeding 6,000 feet the pulse-rate for natives does not 
 differ from the normal standard, and for strangers there is at first quickening 
 of the normal rate and a diminution at a later date, due to a more powerful 
 cardiac impulse and a stronger vascular system. 
 
 With regard to higher altitudes than 6,000 ft., the evidence on the whole 
 VOL. I. o 
 
104 HYGIENE 
 
 points to a decided increase in the pulse-rate, for Zapater at Janja in the 
 Andes (10,000 feet) and Kellet at Landour in the Himalayas (7,000 feet) 
 found the natives with increased pulse-rate. Denison, of Denver in the 
 Eocky Mountains, lays down a law that the pulse increases 2 per cent, for 
 every 1,000 feet ascended. The influence of diminished barometric pressure 
 on the respiration is more marked. The first effect is an increase in the 
 number of respirations, and visitors to high altitudes often complain of short- 
 ness of breath, but after some weeks' residence the lungs becoming expanded 
 and the thorax widened, the vital capacity, as shown by the spirometer, 
 increases, and the respiration rate diminishes and returns to the normal 
 standard or even becomes slower, the respirations being deeper. This would 
 apply to dwellers at moderate altitudes, say under G,000 feet above sea-level, 
 but in natives of higher altitudes the respiration rate has been noted to be 
 higher than normal. 
 
 The tanning of ihe skin, so marked in high-lying places, is undoubtedly 
 due to the greater power of the solar rays from the increased diathermancy. 
 Another well-marked effect of diminished barometric pressure is the soroche, 
 •or puna, or mal des montagnes, which attacks people generally at an altitude 
 of 12,000 feet, and upwards, and appears principally to affect the nervous 
 system. It prevails most markedly in the Andes, and affects human beings 
 and animals on ascending from the sea coast to the higher levels, the bulls 
 for the bull fights being included. 
 
 Eeviewing the relation of diminished barometric pressure to health, we 
 cannot say that it is injurious, but rather the reverse. The attenuation of 
 the atmosphere and the consequent diminution in the amount of oxygen 
 contained necessitates deeper and fuller, and at first more frequent inspira- 
 tions, and consequently we get a larger development of the inspiratory organs, 
 and, as an effect, a more vigorous heart and vascular system. Hence the 
 broad and deep thorax, with accompanying well-developed muscles of the 
 mountain races, such as is seen in the Indians of the Andes, in the guides of 
 ihe Alps, and other mountaineers, who are renowned for their vigour and their 
 great power of endurance during long marches and expeditions. It is stated 
 that the Indians of the Andes can walk 50 miles a day, ascending mountains 
 ■en route. 
 
 Increased Barometeic Pressure 
 
 Our knowledge of the effects of increased barometric pressure on human 
 Tseings is derived, not from the bottom of mines, where there is undoubtedly 
 increase of barometric pressure, but of too slight a degree to cause any 
 distinct influence, but rather from the results of the compressed air used 
 in diving-bells, diving apparatus, and the caissons or tubes employed in the 
 building of piers, for in these latter men have worked for hours at a time 
 ;at a pressure of 2^ to 4^ atmospheres, and, when proper precautions were 
 observed, apparently without harm. 
 
 The symptoms noticed in descending in diving-bells to a depth of 30 feet 
 "were pains in the ears, noises and even deafness, a sensation of tightness as 
 if the head were bound round with iron, these symptoms being more 
 marked if the descent was rapid. At this depth there was no change in the 
 pulse or respiration. 
 
 In pneumatic tubes air is pumped in to the extent of 3 or 4 atmospheres, 
 and workmen are thus enabled to remain at work on the foundations of bridges 
 or piers below the level of the water for several consecutive hours. When 
 precautions in entering and leaving the tubes were duly taken, no marked 
 symptoms were noted, but when this was not so, ill effects were observed. 
 
INFLUENCE OF CLIMATE ON HEALTH 195 
 
 In some works at Douchy, out of 64 workmen, 32 suffered more or less, of 
 •whom two died. On the other hand one, an asthmatic, improved in breathing, 
 :and another, a chloro-anajmic individual, gained colour. Out of 22 workmen 
 who commenced labour at 4:-15 atmospheres, one had slight haemoptysis, eight 
 experienced muscular pains in different parts of the body, some lasting 
 several days, and one, a man of 40, of robust appearance, who descended the 
 tube only once, died immediately after leaving the tube, the pressure having 
 loeen reduced to the normal in twenty minutes. 
 
 In this case a post-mortem examination showed general cutaneous 
 emphysema, congestion of lungs of specially dark tint, the liver, spleen, and 
 kidneys engorged, and the heart containing dark and fluid blood ; nothing 
 abnormal was noted in the brain or meninges. 
 
 Compressed air is employed also in the apparatus by which divers carry 
 ■on operations at depths of 54 metres and less, and it must be remembered 
 that the conditions are not quite the same as in the pneumatic tubes, owing 
 to the additional pressure of the water on the bodies of these men, which at 
 that depth equals 6 atmospheres. Accidents seem more common, and deaths 
 are far from rare. It was calculated that among the sponge divers of the 
 •Grecian Archipelago the mortality was 10 per cent., and this does not include 
 the minor accidents. They appear to suffer in much the same way as those 
 who work in pneumatic tubes, only more severely ; prickings, muscular pains, 
 .and pains in the parts are complained of, the prickings {les puces) never taking 
 place where there is much perspiration, and the muscular pains being most 
 marked in the muscles chiefly used by the divers. One diver had epistaxis at 
 the bottom of the sea, which was repeated on a second descent and accom- 
 panied by severe pains in the head. The serious accidents consist of paralysis 
 of different kinds, and invariably occur after the diver has left the water. The 
 general form is paraplegia, including paralysis of the bladder and of the 
 sphincter ani. In some cases, the loss of power extends to the upper extre- 
 mities and is accompanied by loss of sensation over the whole body. Some of 
 the deaths occur immediately after leaving the water, and appear to resemble 
 those which took place in the works at Douchy. A post-mortem examination 
 after one of the deaths from paralysis showed extravasation of blood between 
 the spinal dura mater and the arachnoid, and the greater part of the spinal 
 cord itself was in a condition of softenmg. 
 
 M. Bucquoy made observations on the circulation of workers in compressed 
 air-tubes, and from a large number of instances concluded that in the first 
 increase of pressure in the tube the pulse rises about 20 beats, and that some 
 increase is maintained during the whole stay, the rate falling at the end of an 
 hour to 7 above the normal ; and M. Gal's observations on the pulse of the 
 Greek divers exactly corresponds with this, for he found, as a rule, an increase 
 of from 70 to 90 beats. M. Bucquoy also found that the respiratory rate in- 
 creased temporarily, but that such increase lasted only about 15 hours after 
 returning to ordinary conditions. We must bear in mind that both in pneu- 
 matic tubes and in diving the workmen are engaged in arduous labour, 
 natiTrally involving, even at ordinary levels, an increase in the pulse and re- 
 spiration rate. 
 
 On reviewing the accidents related, it would appear that they were much 
 more due to the reduction of the high pressures, than to the high pressures 
 themselves. Very few unfavorable symptoms appear to have been noted during 
 high pressure in the tubes, and it is marvellous how well high pressures were 
 borne ; but most of the accidents occurred either during rapid reduction of 
 pressure, or subsequent to quitting the tubes. In many instances, pressure of 
 4-45 atmospheres was reduced in three to four minutes to the normal, a pro- 
 
 o2 
 
196 HYGIENE 
 
 ceediug which has been proved by experience to be fraught with danger. The 
 symptoms seem principally to be due to lesions of the nervous system, com- 
 mencing vnth. dyspnoea, quickening of the pulse, muscular pains of more or less 
 intensity, and gradually increasing in severity ; then come the different forms 
 of paralysis, including loss of sight and hearing, paraplegia, stupor, loss of con- 
 sciousness, coma, and death. The divers appear to suffer more intensely than 
 the workmen m compressed air-tubes ; but among these also' the accidents 
 were almost invariably due to rapid diminution of pressure. 
 
 When, however, air at lower pressure is made use of, as when healthy in- 
 dividuals are submitted to the action of a compressed air bath of 10 lbs. to 
 the square inch pressure, the results are different, great care being taken to 
 increase or reduce pressure gradually. For this reason a compressed air bath 
 is arranged to last two hours. During the first half-hour pressure is gradually 
 increased, then maintained at the full for an hour, and the last half-hour it is 
 slowly diminished to the normal. The first sensations are noises in the ears, 
 a sensation in the pharynx, reheved by swallowing saliva or fluid, and some- 
 times pain in the membrana tympani, all these sensations disappearing quickly 
 on the increase, but returning on the reduction of pressure, and depending 
 on the differences in the density of the air on either side of the membrana 
 tympani. The special senses of taste, smell, hearing, are said to be deadened, 
 the voice becomes shriller, and whistling is impossible. The respiration 
 becomes slower, deeper, and more easy, and the thorax increases in circum- 
 ference, apparently from greater lung capacity. While the respirations fall in 
 number from sixteen or eighteen to four or five a minute, and, as might be 
 anticipated, the relation of inspiration to expiration is changed, and the latter 
 becomes of longer duration tlian the former. The pulse becomes slower and 
 smaller in volume, but of increased arterial tension (shown by sphygmographic 
 tracings), the capillaries are smaller, the veins less full of blood. The amount 
 of decrease in the pulse varies from four to twenty beats a minute. All 
 experiments go to show that compressed air exercises an intropulsive influence 
 affecting naturally those surfaces most exposed to it, such as the skin and 
 lungs ; the blood is thus driven into the organs protected from air pressure, 
 such as the brain, the heart, liver, spleen, and kidneys. The retardation of 
 the pulse is assigned by some to diminished heart's action, owing to the great 
 obstacles the circulation meets with in the superficial vessels. The tempe- 
 rature is slightly raised in the mouth "and rectum, but not in the axilla, the 
 urine is increased in amount, and there is more urea excreted by the kidneys, 
 and more carbonic acid from the lungs. 
 
 Muscular power is increased, and this was found to be the case both in 
 the compressed air bath and in the air at high pressure in the pneumatic 
 tubes. 
 
 WINDS 
 
 There is no question that the great aerial movements which prevail under 
 the name of winds play a very important part in the purifying of the atmo- 
 sphere, and in preventing that stagnation of air which is favourable to 
 bacterial growth and multiplication. They thus are important agents in the 
 promotion of health, for, as the appearance of a great epidemic has been 
 observed to be connected with a very calm state of the atmosphere, so the 
 springing up of a strong wind has often been the signal of its decUne and. 
 disappearance. So con^dnced were the ancient Greeks of the beneficial 
 influence of wind to combat disease, that at Girgenti (Agrigentum), in Sicily, 
 the traveller is shown the artificial opening which Empedocles made in the 
 
INFLUENCE OF CLIMATE ON HEALTH 197 
 
 rock to admit the Tramontana, or north wind, and thus to dispel the malaria 
 arising from the plain below the city. 
 
 We have permanent winds, like the N.E. and S.E. trades, blowing 
 towards the equator from the poles to replace the ascending heated air of the 
 tropics, and owing their direction to the earth's rotation, and we have 
 periodical and variable winds due to local causes not always in action. 
 
 The permanent winds, like the trades and anti-trades, vary their area of 
 prevalence with the season of the year, but there are other winds which are, 
 strictly speaking, seasonal ; as, for instance, the N.E. and S.W. monsoons, 
 which prevail in India and China during certain times of the year, and 
 have been fitly named by Blanford the winter and summer monsoons 
 respectively. The N.E. monsoon corresponds to the N.E. trade, and would 
 be constant, were it not for the special distribution of land and water in the 
 eastern hemisphere. According to Fayrer,' the monsoons are caused in the 
 following manner : ' About the commencement of April, when the whole 
 surface of the continent of India becomes hotter than the sea, the rarefied 
 air rises, and is replaced by the comparatively cooler currents, laden with 
 moisture taken up by evaporation from the Indian Ocean extending from 
 Africa to Malacca. This is the S.W. monsoon, which, rising to higher regions, 
 or being intercepted by the mountain ranges, condenses its moisture in rain 
 on the Western Ghats and on the coast of Aracan. Following a north- 
 eastern course it loses its influence and its rain as it approaches the northern 
 limit of the continent. About October the winds are variable, and there is 
 a reversal of the current, which begins to blow southward, for the most part, 
 as a dry current, till on the Coromandel coast it brings moisture from the 
 Bay of Bengal, which falls as rain on the coast of the Carnatic and Eastern 
 ■Ghats, while some parts of India receive a certain amount of rain with each 
 monsoon.' 
 
 The S.W. monsoon is accompanied by low barometric pressure and heavy 
 rains. 
 
 It would appear, according to Mr. Scott, that in Western Europe the most 
 frequent wind in winter is the S.W., while both in Eastern Asia and Eastern 
 South America it is the N.W. ; but these latter regions differ in this respect, 
 that though W. winds come next to N.W. in both cases, in Asia the S.W. 
 comes far behind, while in Eastern North America it blows as frequently 
 as the west winds. Also, looking at the amount of rise and fall of tempera- 
 ture caused by the prevalence of each wind, compared with the mean 
 temperature, we find the S.W., the most frequent wind in Western Europe, 
 is the warmest in Central Europe, raising the temperature 5°'6 F., while 
 the N.E., the coldest wind in Central Europe, lowering the temperature 7° 
 F., is in the west the least frequent but one of the eight winds ; whereas, on 
 the eastern coasts of Asia and America the most frequent wind— N.W. — 
 lowers the temperature as much as 4°-5 F., while the S. wind, which raises 
 the temperature more than 10° F., is the rarest of all. 
 
 In Great Britain, according to Mr. Glaisher's Greenvrich tables, by far 
 the most prevalent wind for aU seasons of the year is the S.W., and next, the 
 W., these two prevaihng three times more frequently than the N.E., and six 
 times more so than the E. wind ; though probably the latter, from the sensa- 
 tions it gives rise to, makes its prevalence more felt. The N.E. is the rarest 
 wind, and next in rarity come the S.E., the E., and the N., separated by no 
 great intervals. As we know well, the W. and S.W. winds in this hemisphere 
 are the result of the equatorial current and Gulf Stream, and are warm and 
 ;bring rain, whereas the N.E. and E. winds, blowing from the vast continents^, 
 * Rainfall and Climate in India. 
 
198 HYGIENE 
 
 of Europe and Asia, and only moistened by passing the narrow strip of the 
 North Sea, are dry and cold. 
 
 Allusion must be made to the ordinary land and sea breeze, which is ex- 
 plained by Mr. Blanford ^ on the principles of general atmospheric circulation. 
 He holds that ' when the air over the land is expanded, and raised more or- 
 less hke a bhster, the upper strata slide oft" towards the cooler sea and pro- 
 duce an increment of pressure at some distance from the land. The air 
 begins to flow from the region of increased pressure towards that where the 
 air is rarefied, and the pressure is in defect ; and so we have a sea breeze- 
 setting in from the offing ; not a wind drawn in by suction and working its 
 way backwards, as would be the case if the particles nearest the heated spot 
 moved first. At night the action is reversed ; the air over the land is cooled 
 by radiation and contracts ; the isobaric surfaces slope towards the land, and 
 the air above slides down from the sea, sinking over the land and pushing 
 its way out as the land breeze.' 
 
 The valley wind (Thalwind) in the Alps and other mountain ranges, 
 which blows up valleys in the morning, is caused by the air of the valley and. 
 lower regions being heated after sunrise and ascending the mountain sides ; 
 after sunset this is replaced by a wind blowing down the valley, due to the 
 fall of temperature in the valley air from radiation, causing contraction of 
 the lower stratum, and consequently a partial vacuum, which the downward 
 current from the mountains descends to supply. 
 
 There are, however, certain local winds of great influence on the health 
 of the countries in which they prevail, which deserve notice. 
 
 The Khamseen wind is a hot, dry blast from the desert, laden with sand 
 particles, which blows in Egypt for fifty days in the spring. The Harmattan 
 is another withering desert wind, blowing over the Saliara towards the 
 Guinea Coast, and whose influence is felt in the Cape Verde Islands. 
 
 The Simoom is regarded more as a species of whirlwind ; it prevails in, 
 Arabia, and sometimes buries whole caravans in sand. 
 
 The Mediterranean basin and its shores, from their greater warmth in: 
 winter and spring, are liable to the prevalence of winds of great power, which 
 blow principally from the north. These are currents of cool air from an 
 upper stratum rushing in to supply the partial vacuum caused by the heated 
 air ascending from the warm area. 
 
 The principal are the Bise, or Bora, or N.E. wind, and the Mistral, or 
 Maestro, a N.W. wind. It may be stated with regard to the Mediterranean 
 region generally, that its winds present this marked difference from those of 
 Great Britain and Ireland, that whereas, in the latter, the westerly winds 
 are moist and the easterly are dry winds, in the South of France the reverse 
 is the case, and the easterly winds are the moist ones, as E., N.E., and S.E.. 
 (Scirocco), while the westerly, such as the W., and N.W. are remarkably 
 dry winds. 
 
 The N.E. wind is a cold blast, coming generally from some portion of the 
 Alps and their subsidiary ranges, and is most prevalent at the end of the 
 Adriatic under the name of the Bora. At Nice the same wind is called the 
 Bise, and is cold, coming straight from the Maritime Alps. 
 
 The N.W., or Mistral, is the most powerful wind in the South of France. 
 It appears in the Ehone Valley, first to the east of the Cevennes Eange, and 
 sweeps down the valley, carrying destruction to crops, and penetrating to all 
 spots on the Eiviera unprotected by mountain ranges, and making itself 
 much felt at Marseilles and Toulon. 
 
 It blows over the passes in the Maritime Alps, oversetting carts,, 
 • Indian Meteorologist's Vade Mecum. 
 
INFLUENCE OF CLIMATE ON HEALTH V3'J 
 
 carriages, and heavy diligences en route ; and lashing the dark blue waters 
 of the Mediterranean into foam and billows, causing storms in the Gulf of 
 Lyons. With all this it is not a cold wind, but a dry one, and the barren- 
 ness of the mountains of Provence is attributed to its influence. During 
 its prevalence it is not rare for the wet and dry bulb thermometer to indicate 
 a difference of 10° between the bulbs, and it is always a harbinger of fine 
 weather. The first effect of this wind on visitors is agreeable, from its cool- 
 ness, but from its dryness it soon causes unpleasant sensations in the nose 
 and mouth, and often pains in the limbs. In consumptives its appearance 
 has been sometimes followed by an attack of haemoptysis. 
 
 The S.E., or Scirocco, is a wind of the very opposite kind to the mistral, as 
 it is warm, and in Italy and the South of France moist, and generally preludes 
 rain, though in Syria it is regarded as a dry wind. It is supposed to arise 
 in the Sahara Desert, and to gather moisture in crossing the Mediterranean, 
 and certainly its character in the different countries over which it blows 
 would support this, as in Malta and Sicily it is hot and very relaxing, while 
 in Corsica it is less so, but when it reaches the Genoese Eiviera it has lost 
 some of its languor-giving qualities, and is very moist, but not very warm. 
 
 ATMOSPHEEIC ELECTEICITY. 
 
 Though midoubtedly the electrical condition of the atmosphere exercises 
 considerable influence on the human frame, it is difficult to measure its effects 
 accurately, and to separate this influence from that of other meteorological 
 factors. The crackling of hair, and its tendency to stand on end after 
 combing, during frosty weather, is an example of electric discharge from the 
 human body, and sparks have been seen to issue under certain circumstances. 
 
 The illumination of the head of the * parvus lulus ' mentioned in the 
 first book of Virgil's ' ^neid ' has been assigned to atmospheric electricity. 
 
 According to Quetelet's observations at Brussels,' the diurnal march of 
 electricity exhibits two maxima, viz. at 8 a.m. and 9 p.m. in summer, and 
 at 10 A.M. and 6 p.m. in winter, the day minimum being 3 p.m. in summer, 
 and 1 P.M. in winter, and the variations in electricity precede by about an hour 
 those of the barometric range. The maxima occur at the periods of most 
 rapid change of temperature, and the day minimum corresponds with the 
 period of maximum temperature and minimum humidity. It appears that 
 the electrical phenomena in Brussels at any rate are thirteen times more 
 active in January than in July. This coincidence of the electric maximum 
 with the periods of most rapid change of temperature may afford some ex- 
 planation of the extraordinary degree to which some individuals are affected 
 by change of weather, but what would be most interesting to know, is the 
 extent to which the prevalence of certain winds influence the amount of 
 electricity. ' It is generally stated that the potential of the ak is positive, but 
 there are exceptions, possibly depending on the prevailing wind. Clouds are 
 electrified, either positively or negatively, and of course the sign of the 
 electricity recorded close to the ground will be affected accordingly.' 
 
 It is not uncommon for persons standing on the top of a mountain or 
 cliff, during a thunderstorm, to become the conductors of electricity passing 
 from the earth to the cloud, and vice versa. The writer once experienced 
 this at the summit of the Piz d'Arzinol in the Val d'Herens in Switzerland, 
 where a thundercloud enveloped himself and his two companions, and all 
 three felt a distinct buzzing m their hair, like that of insects, which ceased 
 
 ' Scott, Elementary Meteorology. 
 
'iOO HYGIENE 
 
 immediately when a descent was made from the summit. Mr, F. C. Smith 
 and his friends noted on the top of the Piz Languard a crackhng sound, and 
 on raising their alpenstocks points upwards felt the electrical currents 
 passing through their bodies, and heard the crackling as these passed into 
 the sticks. They also experienced the sensation strongly in their temples 
 and their finger ends. Far more serious than these phenomena are the 
 accidents from lightning which occur frequently and are occasionally fatal. 
 
 Accordmg to M. Boudin ^ and others, the principal lesions are loss of 
 consciousness combined with paralysis, more commonly affecting the lower 
 limbs than the upper, burns, skin eruptions, often eczema or urticaria, loss of 
 hair in various parts of the body, wounds, haemorrhage from the mouth, 
 nose, or ears, loss of sight, smell, hearing, and taste, though exaltation of 
 these senses has been known to occur. 
 
 If the individual struck does not die immediately from the efi:ects, he may 
 be expected to recover. The lightning generally, as might be anticipated, 
 takes the line of any metal about the person. It is generally the watch- 
 chain or watch which is shivered or melted, and next it is attracted by the 
 nails in the boots, thus reaching the earth. A most interesting case of 
 lightning injury was shown at the Clinical Society ^ by Sir James Paget from 
 the practice of Dr. Wilks of Ashford, where a labourer, when struck by 
 lightning, had his clothes stripped off him by the current, leaving him stark 
 naked, and severely burnt in various parts of his body. The clothing in 
 contact with metal, such as the watch or watch chain and nails in boots, 
 was completely charred. The fact of the clothing being wet, and therefore a 
 good conductor, doubtless in this case led to more extensive burning than 
 otherwise, and conduced to the freedom of the man from nerve lesions. 
 
 It was found that where flannels touched the skin, the burns were super- 
 ficial, but where the cotton trousers came into contact with it, the burns were 
 uniformly deeper. 
 
 Classification of Climates 
 
 Having considered the elements of climate in relation to health, we can 
 now deal with the influence of the different kinds of climate on human life. 
 
 First we must adopt some form of classification of the various climates 
 of the globe, and indicate as far as we can their geographical limits, giving 
 such description of their chief features as may be necessary by way of 
 explanation. 
 
 It is impossible to classify all climates according to latitude alone, for 
 various influences, such as warm sea currents and mountain ranges, consider- 
 ably modify the effects of latitude ; nor again can we take isothermal lines 
 as our sole basis of division, for these vary with the season and the month, 
 and the isothermal lines of January difi'er from those of July. Then again the 
 relation of a region to the sea coast is most important, as in a tropical country 
 bordering the sea the great heat is tempered by saline breezes night and 
 morning, thus rendering it tolerable to human existence, while in the interior 
 the heat may be extreme, as at Marsak in Fezzan, where an air temperature 
 of 130° F. was registered, and at Cooper's Creek in Australia, where Burke 
 and Wills died, and where after their death a thermometer graduated up to 
 127° F. left in the fork of a tree was found to have burst by the expansion of 
 the mercury,^ but on the coast the temperature is lowered. 
 
 The change of temperature is of course a most important feature of 
 
 ' Holmes's System cf Surgery, p. 398. ^ Clinical Societi/s Transactions, xiii. p. 32. 
 
 ^ Scott, Elementary Meteorology, p. 341. 
 
INFLUENCE OF CLIMATE ON HEALTH 201 
 
 climate, and the regions of greatest annual range are situated witliin the 
 areas of the northern hemisphere. Near Jakutck in Siberia we find a 
 small district with the enormous range of 100° F., Jakutck having a tem- 
 perature of 65° F. in its warmest and — 44°-9 F. in its coldest month. ]Jr. 
 Supan^ has established several laws as to the distribution of the annual range 
 of temperature, among which are the following : — ■ 
 
 1. The range increases from the equator towards the poles, and from the 
 coast towards the interior of the continent. 
 
 2. The regions of extreme range in the northern hemisphere coincide 
 approximately with the districts of lowest temperature in winter, and the 
 range curves resemble in their course the isotherms of January. 
 
 8. The range is greater in the northern than in the southern hemi- 
 sphere. 
 
 4. Li the middle and higher latitudes of both hemispheres, with the 
 exception of Greenland and Patagonia, the western coasts have a less range 
 than the eastern. This is mainly attributable to the general prevalence of 
 westerly winds with the moisture they bring with them, and to the set of 
 warm ocean currents on these shores. 
 
 5. In the interior of continents, the range in mountainous districts dimi- 
 nishes with the height above the sea. This appears to be due to the cold air 
 in calm weather sinking to the lowest level of the valley, and also that moun- 
 tain sides are less liable to the visitations of fogs than the vales below. 
 
 The effect of warm ocean currents on the temperature of certain regions 
 is best seen in the influence of the equatorial currents in the Atlantic, Pacific, 
 and Indian Oceans. These currents, flowing from east to west, are the result of 
 the east trade winds, producing a general movement of the surface water from 
 ■east to west along the equator. In the Pacific Ocean this equatorial current 
 flows till it meets the coast of New Guinea, when it divides and is deflected 
 into two streams, one flowing southwards and striking the coast of Australia, 
 and the other northwards, becoming the Euro Siwo current, or the Great 
 Black Stream of the Japanese seas, which flows outside the Philippines, Loo 
 ■Choo Islands, and Japan, and returning eastwards to North America, washes 
 the southern coast of Alaska Promontory, the northern side being bathed by 
 the cool current coming out of Behring's Straits. The efi'ect, according to Von 
 Baer, is that humming-birds are met with on the southern shore, while the 
 northern one is frequented by walruses. The freedom from ice enjoyed by 
 the harbour of Sitka and the coasts of British Columbia, while the shores of 
 Asia in corresponding latitudes are fast bound in it, is due to the presence of 
 this warm current,^ which passing down the American coast eventually rejoins 
 the equatorial drift current. In the Indian Ocean the water is embayed on 
 the northern side, but the main portion of this part of the equatorial current 
 passes to the south of the line and divides opposite to the Island of Mada- 
 gascar, flowing on either side of it, the inner stream forming the warm 
 Agulhas current, which washes the eastern coast of the Cape of Good Hope. 
 The most important, however, is the x\tlantic equatorial current, which, 
 flowing eastwards, divides off Cape Eoque, one portion turning southward 
 along the coast of Brazil and slightly deflecting the isotherms of that 
 region, and the other and larger portion, following the north-east coast of 
 South America, combines with the westerly current of the north-east trade, 
 enters the Caribbean Sea and reaches the Gulf of Mexico, whence it issues 
 through the Straits of Florida as the Gulf Stream, a majestic current upwards 
 of 80 miles broad and 2,200 feet deep, with an average velocity of four miles 
 an hour and a temperature of 86° F. It follows the line of the American 
 
 ' Scott, 0}}. cit. 
 
202 
 
 IIYGIEXE 
 
 coast to Cape Cod, abutting on the cold Labrador current, T^■hich is 30° F.. 
 colder, and then, taking an easterly direction, spreads over the North Atlantic 
 at a somewhat diminished velocity, and in the meridian of the Azores bifur- 
 cates into two streams, one flowing to the right along the coast of Portugal, 
 towards the Cape Verdes, and the other moving onwards to Northern 
 Europe, skirting the coasts of France, Great Britain and Ireland, and Scan- 
 dhiavia ; then rounding the North Cape, it passes the White Sea and Sea of 
 Kara along the western shores of Nova Zembla and Spitsbergen, and it is 
 stated that its influence can be traced into Behring's Straits. The current 
 moves slowly off the British coast, according to Mr. Scott not more than 
 an inch or so per second, but that, aided by the westerly winds which it 
 probably originated, it does move, is proved by the drift-wood and tropical 
 products from the Gulf of Florida which are washed upon our shores, and 
 even on the shores of Spitzbergen. 
 
 A glance at any map of the isothennal lines for January (see woodcut) 
 
 ISOTHERMS OF NORTH ATLANTIC. [WINTER] 
 105 90 7y 60 ±5 30 15 IS 
 
 ■will show the enormous warming influence of this current, for the isotherm 
 of 41° F. runs through the American coast near Philadelphia (latitude 40°) and 
 slants in a north-easterly direction between Iceland and the Faroe Islands 
 (lat. 62°). The isotherm of 45^°F. starts from the American coast at about 
 latitude 38°, and runs to the north of Scotland and Ireland, and far up into 
 Norway beyond latitude 60°, the warm current thus causing a diversion of the 
 temperature lines towards the north of upwards of 20° of latitude. It is in 
 consequence of this warming influence that Great Britain and Ireland escape 
 the long and severe winter of Labrador, and enjoy their comparatively mild 
 climate, a climate marked by great equability, especially on the coast line, 
 but, as the heating source is a moist one, by a large rainfall. 
 
 Another considerable modification of the effect on climate of latitude is 
 altitude ; for, as Herschel says, in ascending a mountain from sea-level to the 
 limit of perpetual snow, we pass through the same series of climates, as far 
 as the temperature is concerned, that we should by travelling to the polar 
 
INFLUENCE OF CLIMATE ON HEALTH 203 
 
 regions of the globe, and we thus see cities lilve Quito in South America, iu 
 proximity to the equator, but at an elevation of 10,000 feet, enjoying all the 
 year round a cUmate of perpetual spring ; and, again, the mountain sanitaria 
 of Madras, at elevations varying from 5,000 to 7,000 feet, though situated 
 within the tropics, afford a safe retreat for Europeans m the hot season, with 
 a mean temperature varying from 50° F. to 70° F. and with a moderate rainfall. 
 
 The presence of mountain ranges exercises great influence first on the 
 rainfall, and secondly on the shelter from winds. , i, i 
 
 Districts placed to the lee side of great mountain ranges are often sheltered 
 from any powerful wind which may prevail, as is the case with the town ot 
 Pau in the Pyrenees, which, lymg immediately at the foot of the great 
 Pyrenean range, is sheltered from southerly blasts, while the slanting hills ot 
 Les Landes to the north protect it so effectually that the winds from the 
 north pass over the town, striking the Pyrenees on the other side. Wmd is 
 almost unknown at Pau ; the leaves of the trees hardly move, and ram otten 
 falls vertically to the soil. 
 
 Accepting the principle of latitude with these modifications therefore, we 
 would roughly class climates as follows, somewhat after the method ot 
 
 Dr. Henry Bennet. > 
 
 1 Warm Climates : Equatorial ; Trojncal ; Szibtropical.—ClimB.te ot 
 regions lying between the equator and 35° latitude N. and S. Characterised 
 by high temperature, with (as a rule) heavy rainfall, and dry and ramy 
 
 2 Temperate CZmafes.— Climates at regions lying between 35° and 50° 
 latitude, with four well-marked seasons— a preponderance of rainfall m 
 autumn and winter— having a mean temperature from 50° F. to 60 1? . 
 and considerable extremes. 
 
 3 Cold Climates.— Clim&ies of regions lying between 50 and the poles, 
 marked by gradual reduction of temperature as the pole is approached, the 
 greatest cold being 10° from it. The season there consists of a long winter 
 of ten months and of a few weeks of summer. Eainfall small and generally 
 in form of snow. Aurora borealis frequent. 
 
 4 Marine C/imates.— Characterised by the presence of the marine in- 
 fluence— i.e. coasts, islands, peninsulas washed by the ocean or salt seas, 
 and owmg their freedom from extremes to warm currents and the equahsmg 
 influence of the ocean. Such is the climate of Great Britain, Ireland, of 
 Norway, and of many islands. We also include in this division the climate 
 
 experienced in sea voyages. 
 
 5. Mountain CZmates. -Characterised by diminished barometric pressure, 
 increased diathermancy, and by extremes of temperature. 
 
 Warm Climates, extending fbom the Equatoe to 35° Latitude, 
 
 I.E. 12^° BEYOND THE TrOPICS 
 
 This division comprises the greater part of Africa and its islands. South 
 Asia, embracing India and China, Polynesia, including all Austraha except 
 Victoria, North America south of California, and South America north 
 of Uruguay, with the West Indies. _ 
 
 It can be subdivided into equatorial, tropical, and subtropical groups, and 
 in the equatorial the mean annual temperature is from 80° F. to 84° F., the 
 mmimum being 54° F. and the maximum 118° F. The mean temperature 
 decreases slowly as we recede from the equator, the decrease not amounting 
 to more than 2° F. for the first 10° lat. The difference of temperatm-e durmg 
 the day is shght, but there is a fall at night from radiation. There is regular. 
 
204 HYGIENE 
 
 but slight, diurnal barometric variation, the rainfall is about forty inches, 
 and it is evidently this which tempers and reduces the otherwise extreme 
 heat, as it is not found that the highest temperatures or the highest mean 
 annual temperatures have been recorded at the equator, but at or near the 
 tropics. 
 
 The line of perpetual snow is also higher at the tropics than at the equator. 
 The hottest known regions of the Avoiid are on the banks of the Senegal, the 
 Tehama or coastline of Arabia, and the deserts in the interior of Australia, 
 and yet none of these are situated on the equator, though all within the 
 tropics. 
 
 These facts are explained partly by the unequal progress of the sun after 
 the equmox, and partly by the prevalence of rain at the equator, attributed 
 to the meeting of the north and south trade winds in the upper atmosphere, 
 and consequent precipitation of moisture. This is said to be most marked 
 in the region of calms (equatorial) in the Atlantic and Pacific Oceans, where 
 the rainfall is generally heavy. 
 
 In India, according to Blanford and Fayrer, the tropical rainfall depends 
 on the physical features of the country and the monsoon winds. There is a 
 district of low rainfall, chiefly consisting of low hot plains, where the amount 
 does not exceed fifteen inches and sinks in one part to two inches ; and there 
 are regions where the south-west monsoon strikes mountain ranges like the 
 Khasia Hills and the Western Ghauts, where it rises to 493 and 253 inches 
 respectively. 
 
 Prevalent Diseases 
 
 In hot climates, the organs most liable to disease are naturally those 
 -which, owing to the special conditions, are overworked. The lungs and 
 heart are but little taxed, and, according to Parkes, are considerably hghter 
 after death than in temperate or cold climates, showing dwindling of structure, 
 probably from partial lack of function, while the hver, spleen, and intestines 
 are all more or less the seat of increased function, and hence are liable to 
 become diseased. The skin, which is often stimulated to increased secretion 
 in tropical countries, is continually bathed in perspiration, and sometimes 
 becomes in new arrivals in the tropics the subject of lichen tropicus, an 
 affection characterised by great local hyperaemia and swelling of the 
 papillae. 
 
 The effect of great heat on the system generally, and on the brain in par- 
 ticular, is shown in sunstroke, but its influence on particular organs is 
 more difficult to define, because it is usually combined with other causes of 
 disease, such as malaria, the drinking of impure water, and the consump- 
 tion of improper food and various forms of excess. 
 
 "Whilst a great many diseases are assigned to the influence of warm 
 climates, some are wrongly so attributed, but we think that we may fairly 
 ascribe to this cause the following, which appear to have their birthplace 
 within the tropics, even though they may spread at a later date to more 
 temperate regions. Such are sunstroke, yellow fever, dengue, cholera, liver 
 abscess, dysentery, and various kinds of intermittent fever. 
 
 Sunstroke. — The exact amount of influence that the sun's rays exercise in 
 the causation of sunstroke is not ahvays easy to determine, because in many 
 cases there are other conditions present, such as a hot close atmosphere, or the 
 body overheated by exercise and unrelieved by perspiration ; but it is curious 
 to note the rarity of sunstroke in mid-ocean, even in the tropics, and at high 
 altitudes, and yet in both of these situations the solar rays are exceedingly 
 powerful, though the temperature of the atmosphere in either case is never 
 ■excessive. The great heat of the sun's rays at high altitudes depends 
 
INFLUENCE OF CLIMATE ON HEALTH 
 
 205 
 
 probably on the rarefaction of the atmosphere, to which is due the unequal 
 diffusion of the heat and great difference between sunshine and shade 
 temperatures. In the Alps this is more marked in winter, when the ground 
 is covered with snow, and the sun's rays are largely reflected from the surface. 
 The following table of observations on the solar radiation tliermometer 
 (black bulb in vacuo) shows the mean maxima for the four winter months at 
 Greenwich, Cannes, and Davos during the years 1878-9, and indicates the 
 sun-power at a high altitude to be even greater than on the sunny shore of 
 the Mediterranean : — ■ 
 
 Greenwich. 
 
 November, 1878 
 December, 1878 
 January, 1879 
 February, 1879 
 
 79°'9 
 61-0 
 63-8 
 81-4 
 
 Cannes 
 
 122°0 
 105-0 
 1190 
 1210 
 
 Davos 
 
 157°-0 
 147-0 
 141-0 
 lCG-5 
 
 The contrast between sunshine and shade at high altitudes is best 
 exemplified by the following experiment, which was made at Davos. 
 
 InDecember 1878 the writer was sitting with a friend after luncheon, about 
 2 P.M., in the verandah of one of the hotels, sipping coffee. The sun was 
 shining brightly and they felt quite warm, though snow lay all around them. 
 He placed his cup of coffee in the shade, and moved away to assist his friend, 
 who was trying to hght his cigar by concentrating the sun's rays on it with a 
 burning glass. He succeeded in doing so, and the writer returned to his 
 coffee, to find it frozen ! 
 
 Sunstroke, or Insolatio, is generally the result of exposure to solar or arti- 
 ficial heat, and occurs chiefly in tropical countries, but occasionally in 
 temperate climes. Sir Joseph Fayrer ^ states that the most frequent cases 
 are those coming on in houses, barracks, and tents, by night or in the day 
 away from the solar rays, and the subjects of sunstroke are more likely to 
 be those debilitated by disordered health, by dissipation, and by over-fatigue, 
 than those of vigorous constitution, or who have undergone acclimatisation. 
 Hindoo natives on their bare heads and necks endure an amount of sunshine 
 which would be fatal to a European ; but if the temperature rise above a 
 certain standard all succumb, the natives of India suffering like others, and 
 dying from the effects of loo-mama, or ' hot wind stroke.' 
 
 Fayrer gives three varieties of sunstroke. 
 
 I. Showing itself in exhaustion, and failure of the heart's action in 
 
 syncope. 
 
 II. A condition of shock, in which the nerve-centres, and especially the 
 respiratory, are affected, causing rapid failure of the respiration and circulation. 
 
 III. Intense pyrexia due to vasomotor paralysis, and to the nerve-centres 
 being over- stimulated and then exhausted by the action of heat on the body 
 generally. 
 
 From the first form recovery is frequent, but the second or asph^-xial 
 form, sunstroke proper, is more serious, and is generally due to the direct 
 action of the sun's rays on the head and spine. The brain and nerve-centres, 
 especially the respiratory nerve-centre, are overwhelmed by the sudden elevation 
 of temperature, and respiration and circulation fail, the failure of the latter 
 being due to the inhibitory influence of the vagus ; the heart after death 
 being found contracted. The symptoms of this form are generally those of 
 violent injury to the nerve-centres, unconsciousness and cold skin, feeble 
 pulse, and death from rapid failure of respiration and circulation. 
 * Quain's Dictionary of Medicine. Article ' Sunstroke.' 
 
206 HYGIENE 
 
 The third form, the so-called ' heat fever,' is an intense state of feverish- 
 ness, the effect of heat on the nerve-centres, and through them on the 
 vasomotor system, resulting in the raising of the body temperature, generally 
 by heat, solar or artificial, as it may occur independently of the direct solar 
 rays. This form comes as frequently at night or in the shade as by day, 
 especially in persons exhausted by fatigue, dissipation, or overcrowding in an 
 impure atmosphere. 
 
 According to Fayrer, from whose admirable article most of this descrip- 
 tion is taken, the body temperature rises to 108° F., 110° F., or even 
 higher, the brain, medulla, and cord, the nerve-centres generally, and especially 
 the respiratory, suffer from over-stimulation, followed by exhaustion : respira- 
 tion and circulation fail, there is dyspnoea of a hurried gasping kind, great 
 restlessness, thirst, fever, freqiient micturition and pungent heat of skin, 
 which is sometimes dry, sometimes moist. The pulse varies, being some- 
 times full and laboured, sometimes quick and jerking, the face, head, and neck 
 are congested to lividity ; the pupils, at first contracted, may dilate before 
 death. Delirious convulsions (often epileptiform), coma, relaxation of the 
 sphincters, suppression of urine, prelude the fatal termination, but not in- 
 frequently partial recovery takes place, to be followed later by relapse and 
 death. The mortality of sunstroke is about 45 to 50 per cent., but, of those 
 "who recover, many are permanently injured, either in brain power, or in the 
 general health, and we find as a result impairment of memory, nervous irri- 
 tability, headache, and even epilepsy, partial paraplegia, partial or complete 
 blindness, and extreme intolerance of heat, and especially of the sun's rays. 
 
 In fatal cases of sunstroke, the lungs and the pulmonary system are 
 often deeply congested, the heart is firmly contracted from coagulation of 
 myosin, the venous system is gorged, and the body marked by petechias. 
 The blood is more fluid than usual, acid in reaction, the globules have less 
 tendency than usual to form rouleaux, and are deficient in oxygen. The 
 body for some time after death retains a high temperature, and the viscera 
 when first opened feel pungently hot, and the incisions drip dark blood. 
 
 The brain and membranes are intensely congested, and sometimes there 
 are serous effusions into the ventricles, and sometimes haemorrhage into the 
 brain substance ; but the cause of death is generally asphyxia, but apoplexy 
 and the most important changes are found in connection with the thoracic 
 viscera. 
 
 Yellow fever may be said to be limited to subtropical and tropical countries, 
 as it is only found between 32° 70' north, and 22° 5' south latitude. It 
 prevails in the West Indies, the Gulf of Mexico, extending to the southern 
 of the United States of America, and in South America, as far south as Eio 
 Janeiro. It has at times also crossed the Atlantic and prevailed on the West 
 Coast of Africa, between Cape Verd 14° 54' N. latitude, and Cape Coast Castle, 
 5° 7' N. latitude, and has extended to the ports of Western Europe ; cases 
 have also been seen in the Northern States of America. Its relation to 
 climate is singularly distinct. It requires, for its existence and diffusion, a 
 temperature of not less than 70° F., and it is increased by moisture, and thus 
 it can only prevail during hot and moist seasons. Nevertheless, it is 
 extinguished by a heavy rainfall, by cold winds, or by frost or snow. As a rule 
 it is confined to the sea-level, and only rarely, if ever, is found at any height, 
 though it has on one occasion been known to invade towns at considerable 
 elevation in the Andes. It chiefly infests seaports, and for the most part 
 the worst and most crowded quarters, and it spreads almost entirely by 
 infection, and generally attacks strangers coming from northern climates in 
 preference to natives. Acclimatisation gives immunity for one region, which- 
 
INFLUENCE OF CLIMATE ON HEALTH 207 
 
 Tiowever, may be lost by a change of residence to another country. Negroes 
 .and Chmese seem exempt from this disease. 
 
 Prevaihng as yellow fever does in tropical comitries and almost solely in 
 ■crowded cities on the seaside or the banks of rivers, it is probably due to a 
 poison generated or fostered by local pestilential conditions, and in many 
 districts improved sanitation has reduced, and may still further reduce, its : 
 prevalence. 
 
 Dengue is another disease confined to the tropics, and prevails between 
 37° 47' N. and 23° 28' S. latitude, in summer and early autumn. It has 
 appeared as an epidemic in the West Indies and Central America, but it occurs 
 principally in India, China, and Egypt. It is an infectious fever characterised 
 by severe continuous arthritic and muscular pains, debility and prostration, 
 an initial and terminal rubeoloid or scarlet rash, pyrexia rising to 103° F. or 
 «ven 105° F., but speedily declining, though subject to remissions or relapses ; 
 pain and swelhng of joints and glands, and orchitis, and visceral complica- 
 tions, such as diarrhoea and dysentery, and boils are also common symptoms. 
 
 Its period of incubation is five to six days, and the duration of the com- 
 ]plaint, when free from sequelae, about eight days ; but it is sometimes pro- 
 longed to weeks, and like influenza, which it is said to resemble, it often leaves 
 the patient in a very weak and shattered condition. 
 
 Dengue has appeared occasionally m a more severe form than the above, 
 ■with symptoms of hyperpyrexia, coma, cyanosis, and oedema, of the lungs 
 '(Charles), but as a rule it is not a fatal disease. It never occurs in England, and 
 from its appearing as an epidemic and spreading over large tracts of country 
 without any apparent reason, its development has been assigned to some 
 unknown cosmic and atmospheric conditions (Fayrer). 
 
 Asiatic cholera, though its epidemics are diffused over nearly the whole 
 globe, tropical, temperate, and cold countries being visited in succession, has 
 its home in India, where it is endemic, in a region which has been described 
 by Bryden as bounded on the east by the 91st or 92nd parallel of longitude, 
 on the v/est by the 81st parallel, on the north by the latitude of 27° N., and 
 on the south by the shores of the Bay of Bengal (including the delta of the 
 Oanges and the territory at the mouths of the Mahamuddy). This region 
 ■extends from the mountainous districts of the Brahmapootra to the hill 
 regions of Eajmahal and Cuttack, and on its northern border along the Terai 
 from Lower Assam to the district of Purnea. Of this region the delta of 
 the Ganges with a very high annual temperature is assigned as the focus of 
 cholera, and the cholera mortality of the Presidency of Bengal is the greatest 
 in India, the eastern portion of the district being most frequently attacked. 
 -Cholera becomes virulent and spreads from this centre often to other parts 
 ■of India and eventually to other countries of Asia, to Africa, and to Europe 
 and America, North and South ; apparently choosing the great lines of 
 human intercourse for its channel of diffusion ; but, what we as climatolo- 
 gists are most concerned with, choosing the warm and rainy seasons for its 
 march, and rapidly disappearing on the approach of cold weather. The 
 •disease generally travels westwards and somewhat slowly, but it has been 
 proved to be conveyed by both sea and land-routes. The infective material 
 has been proved to be principally contained in the alvine excretions, which, 
 becoming mixed with the water-supply of a city or town, may rapidly poison 
 a whole community, the smallest quantity of the infective material impart- 
 ing to enormous volumes of water the power of propagating cholera (Simon). 
 The disease may also be communicated directly by cholera patients in 
 crowded and badly ventilated rooms, as well as from their soiled hnen. 
 
 Seaports are generally attacked by cholera, and a saline atmosphere affords 
 
208 HYGIENE 
 
 no protection ; but, on the otlier hand, it is ascertained that a certain altitude 
 above sea-level has often been shown to confer immunity, and in India it 
 is the practice to remove troops to hill stations when the disease breaks out. 
 
 Switzerland was exempt during most of the great epidemics, and both m 
 England and France it was found that more or less elevated districts sufiered 
 far less than low-lying ones. 
 
 The diffusion ot cholera appears to follow the course of rivers, and Hirsch 
 holds this to be due to the more copious saturation of the ground, coupled 
 W'ith the retention of organic matters undergoing decomposition, and he 
 remarks that one of the best proofs of this is, that the amount of sickness 
 diminishes in proportion as the disease in its progress travels further from 
 the margin of the river basin. 
 
 Dysentery, Diarrhoea, and Tropical Abscess of the Liver. — These diseases 
 have been placed together in the same category as apparently due to similar 
 causes, and forming in many patients various links in the same chain of 
 pathological events. How far they are due to tropical climates alone, or to 
 the mfluence of malaria or to impure drinking water, is not always clear, for 
 in many instances all these factors are at work together, and unquestionably 
 a good supply of drinking water has lowered the death-rate from diarrhoea 
 and dysentery in many tropical countries, as much as a reduction in the 
 quantity of alcohol consumed by English troops has diminished the number 
 of cases of hepatitis and liver abscess. 
 
 The connection of malaria with dysentery has always been strongly held 
 by some Indian surgeons, who are able to point to the fact of both diseases 
 diminishing and often disappearing under the efficient draining of swampy 
 districts ; but the opinion gains daily that though dysentery may be due in 
 some cases to malaria or to any poison congesting the portal system and the 
 spleen and the liver, the greater part of dysentery arises from other causes, 
 such as impure water, bad drainage, and especially the accumulation of 
 dysenteric stools, and improper food. Hirsch, too, considers that it is 
 neither ' in high temperatures, nor in an extreme range of the thermometer 
 inducing chills, that we have to look for the endemic factor of dysentery and 
 diarrhcea,' though he admits ' that extreme fluctuations of the temperature 
 (iji so far as they induce chill) are among the most inviting opportunities for 
 the malady to start.' 
 
 Nevertheless, whilst admitting that dysentery may occur in any country 
 or clime under special circumstances of bad water, food, and drainage, as has 
 been repeatedly demonstrated in outbreaks during campaigns, we cannot 
 disguise the fact that it is far more common in tropical climates than in 
 temperate, and we must accept heat, though not necessarily moisture, as an 
 element, though not as an absolutely essential one, of its causation. 
 
 Abscess of the liver, though known in temperate and cold climates, where 
 it is a rare, and, for the most part, a secondary disease, is tolerably common in 
 the tropics, and especially in India, where it forms a conspicuous feature in 
 the disease statistics of both the European and native troops, and is partly 
 due to the extreme heat to which they are exposed, and partly to alcoholic 
 excesses. 
 
 Malaria. — This poison is found in operation not only in tropical, but in 
 temperate climates, though not in cold ones, but as it is far more common 
 and reaches its greatest point of concentration and virulence in tropical 
 climes, we have selected the division of warm cHmates for its consideration, 
 alluding in passing to its manifestations in temperate climates. Though 
 some advance has been made by recent investigations in our knowledge of 
 the intimate nature of malaria, it cannot be said that full explanation has 
 
INFLUENCE OF CLIMATE ON HEALTH 209 
 
 yet been given of the variety of conditions of soil and atmosphere under 
 which it prevails, the conditions being often of an almost opposite character, 
 as, for instance, in India it is found in the water-logged marshy ground of 
 the Terai, and also in the sandy dry soil of the Deccan. The presence of 
 water, and especially of salt water in large amount in a marsh, appears to 
 reduce the malarious influence, but the drying up of a marsh, or of a river 
 bed, or the subsidence of a flood, is generally the signal for an outbreak of 
 intermittent fever. 
 
 According to Dr. W. Maclean, the remittent fever which devastated the 
 British army in the Peninsular War, when encamped on the sunburnt plains 
 of Ciudad Eodrigo, may be explained by these plains having been the scene 
 of floods, which had recently dried up under the scorching sun of a Spanish 
 summer. Fayrer considers that subsoil water or damp is the most essential 
 condition of malaria, and especially if the subsoil be impregnated by a 
 certain amount of stagnant moisture, and that this is probably present in 
 many of the localities in which the appearance of malaria is so difficult of 
 explanation. 
 
 According to him, malaria is at its worst in India in the drying-up season 
 after the rains, but during the rains it is less severe. The turning up, or 
 excavation of new soil, generally increases the danger, but the cultivation, 
 draining, and cropping of the same soil generally diminishes or abolishes it. 
 
 Parkes gives as examples of soils with the largest organic emanations, 
 and therefore most likely to be the source of the malaria — 
 
 1. AUuvial soils, old estuaries, and deltas. 
 
 2. Sands, if there be impermeable clay, or marly subsoil, and old water- 
 courses. 
 
 3. The lower parts of chalk, if there be a subsoil of gault or clay. 
 
 4. Weathered granite trap rocks, if vegetable matter has become inter- 
 mixed. 
 
 5. Eich vegetable soils at the foot of hills. 
 
 Klebs and Tommasi-Crudeli discovered in the air and soil of the Eoman 
 Campagna a microscopic fungus, consisting of numerous moveable shining 
 spores of a longish oval shape. This ' bacillus malarige,' as it has been 
 called, is capable of artificial cultivation in suitable media, and when injected 
 into dogs produces well-marked symptoms of intermittent fever, and their 
 spleens are shown to enlarge. The bacillus malarise has been detected in 
 the blood of human patients, during the period of invasion of the fever, but 
 during the acme it disappears, and spores only can be discovered. It has 
 also been found in the spleen of human subjects, and in the marrow of the 
 bones of the animals inoculated. The conditions of growth of this bacillus 
 are heat and moisture. The proof of malaria residing in the soil is shown 
 by the fact that shutting off the soil by paving, as has been done in Eome, 
 abolishes the malaria, and even when the sun's rays are intercepted by fog 
 or cloadthe fever is lessened. 
 
 Apart from other elements, heat seems in all climes to be the deter- 
 mining cause of malarious fever, whether remittent or intermittent, as the 
 cases of ague occurring in England, in Essex and Lincolnshire, are developed 
 during the summer and autumn, and on the shores of the Mediterranean 
 tracts of land which would be exempt from malaria in this country become 
 teeming with miasm under the influence of the powerful southern sun. 
 This is the case of the deltas of rivers in the south of France and Italy, and 
 the embouchures of streams in Corsica and Sardinia. In some places, as at 
 the mouth of the Var, the embanking of the river has, by raising the river 
 bed, developed malaria among the dwellers on either side. 
 
 VOL. I. p 
 
210 HYGIENE 
 
 On the west coast of Corsica, the streams discharge into the sea by rochy 
 chatinels, the greater part of the coast being of that character, and there 
 only exist small deltas at their mouths, but these imder the solar inlluence 
 produce malaria in the summer, which is wafted by the westerly winds up 
 the mountain valleys for a considerable distance. It is held by many 
 authorities that the summer isotherm of 58° F. to 60° F. limits the occur- 
 rence of intermittent fever, and that regions where the mean summer 
 temperature does not reach this iigure are exempt from malaria, a conclu- 
 sion abundantly proved by evidence ; and Ilirsch remarks that confirmation 
 of this is notably found in the fact that the extent and intensity of the 
 disease in malarious foci at the different seasons of the year are in direct 
 proportion to the height of the respective temperatures, and also in the fact 
 that the great epidemics and pandemics have been immediately preceded by 
 hot years, or have coincided Avith them. 
 
 The effect of malarious poison on the human system is as conspicuous 
 as its action is msidious. First we get the nervous system attacked with 
 neuralgic migraine, or some other form of nerve storm ; then comes asthma, 
 another neurosis so commonly associated with malaria. And later the 
 morbid changes in the spleen and liver, and in time those degenerative 
 changes in the tissues which give to the patient the appearance of malarious 
 cachexia. As the poison increases in intensity, and the climate becomes 
 hotter, we get fever, at first intermittent, quartan, tertian, and quotidian, 
 and further south we find the remittent form so common in the tropics. 
 
 Fayrer teaches ua that natives of India are attacked quite as much as 
 Europeans by malarious fever, and even that dogs, and horses, and cattle are 
 affected. The mortality of British troops in Bengal from fever is less than 
 3 per 1,000, but that of the natives is nearly 25 per 1,000, and the difference 
 is attributed to the natives being poorly fed and badly housed. 
 
 We will now close our account of warm climates and their influence on 
 health, having indicated the principal, though by no means all, the diseases 
 which are assigned to them, with the conclusion that for Europeans who 
 have gone through the ordeal of such complaints, and survived them, change 
 of chmate, and especially a return to their own temperate climate, is the best 
 means of restoring health. 
 
 The climate of the desert forms an important sub-group of warm climates, 
 and, as it is a good example of the combination of warmth and dryness, it 
 merits a few words of special description. As an instance may be cited the 
 tract commencing Avith the Great Sahara and extending eastwards through 
 Arabia to Persia, and therefore including the Egyptian desert ; other examples 
 are the desert of Gobi in Chinese Tartary, the Kalahari in South Africa, the 
 Great Salt Lake district in North America, and the vast deserts in the interior 
 of Austraha. 
 
 Let us take Egypt as a type of the desert chmate, including its principal 
 features. 
 
 First, its dryness. The rainfall at Cairo is 1-22 inches, occurring in 
 occasional showers lasting 15 to 80 minutes, seldom longer. At Thebes rain 
 is exceedingly rare, and in the province of Esneh it is almost unknown. The 
 number of days on which rain falls at Cairo varies from 12 to 15, and is less 
 in Upper Egypt, but the state of the atmosphere is best shown by the hygro- 
 meter, as on the Nile the difference between the wet and dry bulbs sometimes 
 amounts to 24° F. and the annual relative humidity percentage is 68*46. 
 
 The best proof of the dryness of the desert atmosphere is to be seen in the 
 state of the mummies, which there remain unchanged for centuries, though 
 their removal to a moister atmosphere, such as that of Alexandria, causes 
 their immediate decomposition. 
 
INFLUENCE OF CLIMATE ON HEALTH 211 
 
 Second, its purity. Prince Zagiell " has shown that while atmospheric 
 air contains as a rule 4 parts of carbonic acid in 10,000 parts, the air of the 
 desert contains no trace of this gas. Moreover, putrefaction appears checked, 
 and meat, when exposed to the open air, becomes, after three weeks, dry and 
 completely mummified, without any sign of decomposition. Zagiell has also 
 noted that vegetable fermentation does not take place, and ripe fruits when 
 left on the trees dry up without becoming rotten. This aseptic quality of 
 the air is further demonstrated by the rapid healing of wounds and ulcerations 
 to which the surgeons bear testimony, and also by the fact that phthisis 
 appears to be unknown among the tribes of the desert, though cases are 
 to be found in Cairo, where the evil influences of a great city prevail. 
 
 Third, the difference between night and day temperatures due to the 
 effect of radiation. This has been noted by Dr. Marcet ^ even in winter to 
 amount to between 17° and 18° F. There appears to be two seasons, one 
 comparatively hot, and one comparatively cool, but in both the effects of 
 radiation show themselves. The winter, consisting of November, December, 
 January, and February, gives a mean of 58°"3 F., the summer average being 
 76°'l F. The maximum of five years' observations at theKhedivial Observatory 
 in a suburb of Cairo was 111° F.,^ occurring July 13, 1888, and on a night 
 of January, 1887, the minimum of 35° F. was reached. 
 
 Prince Zagiell's observations, taken every two hours in the twenty-four, 
 show the maximum to be attained between 2 and 3 p.m., and to vary in winter 
 between 79°'2 F. and 83°"7 F., while the minimum is reached between 3 and 
 4 a.m., and varies from 38°"7 F. to 39°"9F., a range of 45 degrees. Snow 
 is quite unknown, though ice has been noticed at night on extremely rare 
 occasions. 
 
 In Middle and Upper Egypt, during summer, the sand becomes so 
 intensely heated during the daytime, that although the radiation is great at 
 night, the air remains warm from the direct action of the emitted heat, and 
 this is especially the case with reference to the layer of atmosphere over the 
 soil.* During that season in Middle Egypt the temperature rises by day from 
 96°-5 F. to 104° F. and falls regularly at night from 86° F. to 72°-5 F., while 
 in Upper Egypt the temperature in the daytime ranges from 95° F. to 113° F. 
 and falls at night from 90°-5 F. to 65°-7 F. 
 
 The winds which generally prevail in Egypt are from the north, and 
 enable the dahabeahs and other sailing vessels to ascend the Nile against its 
 strong current. These winds are cool and refreshing ; but there is one, the 
 Khamseen, which possesses the very opposite qualities, and is very pernicious 
 to animal and vegetable life. 
 
 The Khamseen blows from the south or south-east, the more easterly 
 variety being the most disagreeable.'^ It generally lasts three days, but may 
 extend to seven. This wind is of rare occurrence, the number of days being 
 only from four to twenty in the year. The sky is clouded by fine sand held 
 in suspension and rendering the atmosphere grey in colour and obscuring the 
 sun's rays, so that the appearance is like that of a London fog. But the air 
 is hot and dry, and when the wind veers round to the north a fall of some- 
 times 30° F. takes place. The Khamseen shrivels up roses and other flowers, 
 and will even warp and crack unseasoned wood. The effect on human 
 beings is to cause listlessness and languor, not only in Europeans, but in 
 
 ' See Marcet, Southern and Siuiss Health Besorts, p. 207. 
 - Qiiarterly Journal of Meteorological Science, October 1885. 
 5 F. M. Sandwith, Egypt as a Winter Resort, p. 24. 
 ■• Marcet, Southern and Swiss Health Besorts, p. 207. 
 ' Sandwith, Egypt as a Health Besort. 
 
 P 2 
 
212 HYGIENE 
 
 the natives, ^vllo are seen lying about unfit for tlieir work. It has not been 
 proved to be harmful, but rather the reverse, to phthisical and bronchitic 
 patients, but the rapid fall of temperature which succeeds has to be carefully 
 guarded against. 
 
 The climate of the desert, as will bo seen, is warm and very dry and 
 aseptic, and as such has proved of great benefit in the treatment of phthisis 
 and scrofula. 
 
 The writer's statistics show that out of 20 consumptives who spent 2G 
 winters in Egypt, no less than G5 per cent, improved, 25 per cent, remained 
 stationary, while only 10 per cent, deteriorated. Dry pleurisy, bronchitis, and 
 spasmodic asthma, especially if combined with emphysema, benefit largely 
 by a winter in Egypt, and chronic rheumatism is wonderfully alleviated. 
 
 Ophthalmia and other eye afl'ections prevail largely in this country, and 
 are in part attributed to the climate and soil. A large class of nerve affec- 
 tions are greatly benefited by a winter's residence in Egypt, and specially 
 by life in a dahabeah. 
 
 The climates of Algeria and Morocco deserve a passing notice, because, 
 though in close proximity to the Great Sahara Desert, they differ greatly 
 from the climate of the Egyptian desert ; and, again, though they form the 
 southern shore of the Mediterranean, their meteorology presents a great 
 contrast to that of the northern shore. 
 
 The French province of Algeria is a strip of country about 1,200 miles 
 from east to west, and 200 miles from north to south, extending into the 
 Great Sahara Desert, being situate between 32° and 37° north latitude. 
 
 The mountain ranges of the Great, Middle, and Lesser Atlas traverse 
 the province from east to west, and form three chains more or less parallel 
 to each other. The Lesser Atlas skirts the Mediterranean at a distance 
 varying from 1 to 15 miles, and is separated from the Middle Atlas by the 
 fertile valley of the Chelifi', and the Middle Atlas is again divided from the 
 chain of the Great Atlas by the Algerian desert, an elevated plain contain- 
 ing salt water lakes, with an altitude of several thousand feet. Beyond the 
 Great Atlas lies the Sahara Desert, which, according to Dr. Bennet, is the 
 key to the Algerian climate, and converts, what would be a dry, into a moist 
 clime. 
 
 The atmosphere which overlies this immense rainless tract of desert, 
 becommg heated both in winter and summer, must rise into the higher 
 strata, and thus form a vacuum, which the cooler and heavier air of the 
 Mediterranean basin rushes down to fill. The latter is sucked in over the 
 summits of the Atlas ranges, consequently in Algeria the regular winds are, 
 and must be, either north-east or north-west winds, and south winds can, 
 and only do, blow exceptionally. 
 
 These northerly winds, coming from the Mediterranean Sea or the Atlantic 
 Ocean, are moist winds, and when they come into contact with the Atlas 
 mountains are at once cooled and deposit their moisture in copious and 
 frequent rain over the entire Algerian or Atlas region, and extend into the 
 desert itself, 250 miles from the sea. Consequently the rainfall at Algiers 
 is heavy, about 32 inches, distributed over 87 days, occurring chiefly in 
 winter. The year is divided into two seasons, the hot and the rainy, the 
 former extending from April to November, and the latter from November 
 to April, the largest rainfall and the greatest number of rainy days occurring 
 in November, December, and January. In the summer the rain often falls 
 for several months, and occasionally seasons of drought have occurred even 
 in winter. Such dry seasons are generally accompanied by a plague of 
 locusts, which invade Algeria from the desert, penetrating the Atlas through 
 
 i 
 
INFLUENCE OF CLIMATE ON HEALTH 213 
 
 the passes and roads constructed by man, and devastating the fertile valleys 
 of the Chehff and destroying whole crops of cereals. 
 
 The rainfall of Algeria increases on proceeding eastward. Of the three 
 provinces into which the country is divided, Oran, the most westerly, has the 
 least rainfall. Constantine, the easternmost, has the greatest ; while in Algiers, 
 ■the central one, the rainfall is double that of Oran, and about half that of 
 Constantine. This has been accounted for by the distribution of forests, 
 "which are extensive in the province of Constantine, less so in that of Algiers, 
 and have all but disappeared in Oran. 
 
 Most of the winds, as has been stated, are northerly and westerly, but the 
 Scirocco or S.E. wind, here a blast from the desert, occasionally prevails, and 
 is injurious to man and destructive to vegetation. It occurs for the most part 
 between June and October, and is accompanied by great heat. The mean 
 annual temperature of Algiers is G2° F. (Scoresby- Jackson), the temperature 
 ■of the three winter months being 56° F. (Pietra Santa), and that of the rainy 
 season 62° F. The difference between winter and spring mean temperature 
 is small. It will be seen that the climate differs from the climate of Egypt, 
 being far moister and, rather cooler, and with regard to the first feature, it 
 presents a contrast to its neighbour, the south-eastern corner of Spain, 
 which is often arid and burnt up from drought, as if the rainfall of this 
 region had been diverted to Algeria in the manner described by Dr. Bennet. 
 
 The climate of Algeria is milder and moister than that of the Eiviera, and 
 ■occupies an intermediate place between the latter and that of Tangiers in 
 Morocco, where the equalising influence of the Atlantic is more felt in mode- 
 rating extremes ; but the great advantage which Algeria possesses over Egypt 
 and the Eiviera lies in the number and variety of sanitaria it offers to invalids. 
 Algiers with its suburbs offers them shelter and saline breezes, while Blidah, 
 Milianeh, and Medeah are excellent mountain stations, and the desert air and 
 cHmate can be tried at Biskra in the Sahara, now connected to Algiers by 
 railway. 
 
 In Algeria we can witness, too, the life of the nomad Arabs, who dwell in 
 tents and move their houses and flocks according to the season, preferring 
 the plains in winter and the mountains in summer. Among this race phthisis 
 ^nd scrofula are unknown ; but when a number of them were imprisoned by 
 the French Government, fifty per cent, died of phthisis. 
 
 The Algerian climate has been found of great value in the treatment of 
 ^consumption, and the writer has recorded some remarkable cases of arrest 
 under its influence. 
 
 Tempeeate Climates, compeising the Eegions between 
 35° AND 50° Latitude 
 
 This division includes Central and Southern Europe with its islands, the 
 part of Asia between the Mediterranean, Black Sea, and Japan, a great part of 
 North America and South America, south of Uruguay, besides the Colony 
 •of Victoria in Austraha, New Zealand and Tasmania, and numerous isles. 
 
 The mean temperature varies from 50° F. to 60° F., a figure made up of 
 -considerable extremes. The rainfall also varies in amount, being dependent 
 on the proximity to the sea or mountain ranges. The four seasons are well 
 marked, but the length of each varies considerably accordingly to latitude. 
 This group of chmates must be regarded as by no means uniform in its 
 features, the climate of each region approximating in meteorology to either 
 the warm or cold groups between which it is placed, according to the nearness 
 of either. The vast inland tracts of Central Asia and British North America 
 
214 HYGIENE 
 
 possess a very difierent climate from the Genoese Riviera and the Atlantic 
 coast of the Spanish Peninsula, 
 
 The inland climates of Central Europe, Asia, and North America are 
 characterised hy extremes of temperature, as is shown in the Canadian 
 winter and summer, and hy dryness ; whereas in the countries fringing the 
 sea like the Atlantic portions of France, and Spain, and Portugal, these 
 extremes are greatly reduced, and the rainfall is larger. 
 
 The temperate climates are inhahited by the most vigorous races physicallj'' 
 and intellectually, and would seem to have been in all ages specially favour- 
 able to the growth and development of human vigour and intellect, as shown 
 by the example of Greece and Rome. 
 
 Among the varieties of temperate climates is to be named that of the 
 shores of the Mediterranean Sea, as, owing to the shelter from northerly 
 winds afforded by the mountain ranges to the north of it, and the equalising 
 influence of this warm body of water, which is neither cooled by glacier 
 streams nor polar currents, and which undergoes considerable heating from 
 its latitude, the north shore, and especially the Genoese Riviera, enjoys a 
 very favourable climate, in which both extremes are considerably tempered. 
 This is most marked in the different islands of the Mediterranean, such 
 as, among others, Malta, Sicily, Sardinia, Corsica, Crete, Cyprus, and the 
 Balearic Isles. The summers are someAvhat hot, but the extremes are 
 considerably modified by this inland sea. 
 
 The winter climate of the Riviera is warmer than that of the British 
 Isles, by at least 3° F. It is dry and stimulating, with an average rainfall 
 of thirty-one inches,^ and the average number of rainy days is sixty-five. 
 The winter and spring months are comparatively dry, and the principal rain- 
 fall is in September, October, and November. It exercises a highly beneficial 
 efiect on many forms of chronic disease, chiefly by its stimulating influence,, 
 and in the treatment of phthisis has been proved to be of the greatest utility,. 
 
 The statistics of the hospitals of this region show that chronic degenera- 
 tive disease is rare, while acute disease is common, and it is possible that 
 this is the key to ihe successful treatment of chronic disease in this region, 
 for it is found that Avhereas cases of chronic bronchitis, phthisis, rheumatism,, 
 and kidney disease, improve steadily under the stimulating influence, various 
 kmds of inflammations, such as gastritis and enteritis, and afi'ections of the 
 nervous system, especially hysteria and insomnia, are rendered worse instead 
 of better. Pyrexia is generally augmented, and typhoid fever is reported to- 
 run a more protracted course than in the North of Eiuope. 
 
 Prevalent Diseases 
 
 These are for the most part the ordinary diseases described in European 
 and American text-books of medicine, and it will be unnecessary to 
 recapitulate them, unless there be any which can be fairly attributed to the 
 influence of climate. 
 
 Rheumatism, both acute and chronic pneumonia, croupous and catarrhal, 
 and various affections of the air-passages and lungs, prevail largely in 
 temperate climates, and may be fairly attributed to the vicissitudes of the 
 weather, especially during the winter months, as during the summer there 
 is marked diminution in the mortality from these causes. On the other hand, 
 hay fever, a disease limited to temperate climates, prevails only in summer, 
 owing to the presence in the air of the pollen of various flowering plants, 
 which enter and irritate the nasal passages, the conjunctivae of the eyes, and 
 the larynx, pharynx, and lungs, the active symptoms disappearing on the^ 
 
 1 Symons, Quarterly Journal of the Boyal Meteorological Society, Jannaiy 1890. 
 
INFLUENCE OF CLIMATE ON HEALTH <2,\rj 
 
 removal of the sufferer to the seaside, or at the close of the pollen season. 
 This troublesome, though not dangerous complaint, prevails in Europe and 
 North America during the summer months, and disappears in autumn. 
 
 The large group of exanthemata, and other fevers that prevail in tempe- 
 rate climates, are due to the action of organisms, and therefore cannot be 
 attributed to climate, except in a secondary sense, as fostering their growth. 
 In the same way such diseases as goitre and cretinism are attributable to local 
 causes, these being the special conformation of valleys, peculiarities of soil, or 
 certain mineral salts present in drinking water, or again individual predis- 
 position. These diseases cannot be assigned to general climatic influences, 
 more especially as they are found to prevail under such opposite conditions 
 of temperature as the Soudan in Africa and British North America, and also 
 both in dry and in moist climates. 
 
 Many diseases, like leprosy and pellagra, have been referred to peculiarities 
 of diet, which has been proved in the case of pellagra in Italy, but is not yet 
 substantiated with regard to leprosy ; but this latter disease, prevailing as 
 it does under the most varying conditions of climate, must be considered 
 entirely independent of this factor. 
 
 Pulmonary consumption cannot be said to be the special production of 
 severe climate, though doubtless immunity from the disease has been shown 
 to exist under various and indeed opposite climatic conditions. 
 
 Cold Climates 
 
 This division embraces a large area, from 50" N. latitude to the poles, a 
 great portion of which is ocean, or else, as is the case with the southern 
 pole, unknown regions. The habitable portions are in the northern hemi- 
 sphere and include the North of Scotland, Denmark, Sweden and Norway, 
 Iceland, Finland and Lapland, Northern Eussia, with Spitzbergen and 
 Nova Zembla, Siberia and Kamschatka, and in America, part of British 
 North America and Greenland. This group has been subdivided into a 
 cold region, with a mean temperature between 50° and 32° F., and a glacial 
 region with a mean below the freezing point. 
 
 The temperature falls rapidly between latitudes 55° and 75°, and the fall 
 amounts to 22° F. to 27° F., the coldest region being not at the pole, but about 
 10° from it north of Behring's Straits, the mean temperature there ranging 
 between 17° F. and 19° F. 
 
 As is well known, in the more northerly portion the sun never rises above 
 the horizon for several months in the winter, when the sky is illuminated by 
 the aurora borealis, and in the summer for several months the sun never 
 sets. During this season, June and July, the temperature rapidly rises to 
 55° F., to 60° F., to 80° F., or even 90°' F., and rapid development of the 
 vegetation and growth takes place, but at the end of July fogs and 
 rain appear and are soon succeeded by snow and frost, and the long winter 
 again recommences, during which there is scarcely any diurnal variation 
 of temperature. The winds seem chiefly N.E. and S.W., and their rapid 
 changes give rise to tempests. The rainfall, generally in the form of 
 snow, only amounts to a few inches. This description does not apply to the 
 whole of the cold region, but to the northern part of it, whereas the portion 
 abutting on the temperate zone partakes of that climate. The inhabitants 
 of cold regions are, as a rule, a vigorous race, possibly from the severe 
 battle of life they must fight to maintain existence, and their diseases may 
 be generally traced to either defects in their dietary or their overcrowding 
 in small and ill-ventilated huts. Scurvy and scrofula are the principal 
 diseases, the former arising from a deficient supply of vegetables and fruit, 
 
216 
 
 HYGIENE 
 
 and the latter from the overcrowding and want of a proper supply of food 
 generally. Ophthalmia and amaurosis are also reported to be present, 
 from the reflection of light from the snow in the polar regions. As 
 physicians, we have little to do with this class of climates, but we must not 
 forget that dry cold, which is the feature of this group, has a bracing efifect 
 on the human system, unproves the appetite, promotes the performance of 
 a large amount of muscular work, and, as it is fatal to all germs, is a good 
 antiseptic. 
 
 Makine Climates 
 
 are characterised chiefly by marine mfluence, and especially by the presence 
 of warm sea currents, the regions included being capes, islands, peninsulas, 
 and promontories washed by the ocean or salt seas, which by their warmth 
 and equalising influence raise the mean temperature of the adjacent regions, 
 and at the same time temper the extremes. The source of heat being a 
 moist one, the humidity and rainfall are increased, and add a certain soft- 
 
 40° 39' 
 
 ness to the atmosphere. Such is the climate of Great Britain and Ireland, 
 the coasts of Norway and Iceland, which all, from their relation to the 
 equatorial current and Gulf Stream, enjoy a far milder, though moister, 
 climate than they would experience if situated at the same latitude in the 
 centre of Asia or of North America. 
 
 The British chmate may be taken as the type of this class, as it certainly 
 
INFLUENCE OF CLIMATE ON HEALTH 2l7 
 
 owes its mild atmosphere to the sea encompassing our islands, and to the 
 warm equatorial current and the winds generated by it. This is shown in 
 several remarkable ways. First, the winter temperatures of the towns on 
 the south coast are higher than inland places at no great distance from them 
 (Tripe). Second, the mean winter temperature of these stations decreases 
 towards the east of the British Channel, the mean winter temperature of 
 Hastings being 6° F. less than that of Torquay. Third, the effect on the 
 winter isothermal lines of Great Britain (see woodcut). In August the 
 isotherms (dotted lines) very much follow the lines of latitude, the east coast 
 of England being slightly warmer than the western coasts of England and 
 Ireland, but in January the isotherms (continuous black lines) become almost 
 vertical, the isotherm of 39° F. running through Shetland and the islands 
 off the west coast of Scotland to Hastings, while that of 40° F. passes 
 through the Isle of Man, Llandudno, and Portsmouth. The isotherm of 
 43° F. runs through the extreme south-west of Ireland, through Devonshire 
 and the Channel Islands. Thus the power of the sun being weakened in 
 winter, the influence of the equatorial current is more sharply shown, and 
 we see what a valuable warming agent it proves to us in winter. Fourth, in 
 the increase in the rainfall. This is much greater on the western coasts 
 of England and Scotland, which are strongly under the influence of the 
 equatorial current, than on the east coast, which is less so. The rainfall of 
 the west coast varies from 60 to 80 inches, and that of the east coast is 20 
 inches, and on the east coast the extremes of temperature are also more 
 marked. The characteristics of the British climate are absence of extremes, 
 great humidity, and great variability and absence of sunshine. The result 
 is to be seen in a vigorous race, liable to various diseases arising partly from 
 vicissitudes of climate themselves, and partly from confinement within doors 
 which these, to some extent, render necessary. The good complexions of 
 the British, and especially of the women, are due to the protection from 
 sunburning which the moist vaporous atmosphere affords. 
 
 The principal diseases due to chmate are those affecting the lungs and 
 air-passages — such as asthma, bronchitis, pharyngitis, laryngitis, pleurisy, 
 pneumonia and phthisis, rheumatism and its sequelae, and various forms of 
 kidney disease ; the greater part of which may be attributed to the dampness 
 of the climate and the constant changes in the weather. 
 
 Eheumatism and bronchitis prevail most in the winter months, and, 
 according to Scoresby-Jackson, a low mean temperature during the winter 
 months gives rise to an increase in the death-rate from phthisis and 
 bronchitis, and this relationship is more clearly to be observed if the low 
 temperature be sustained for some months without intermission. 
 
 Phthisis prevails all the year round in England, and it has been demon- 
 strated to bear a distinct relationship to dampness and impermeability of soil, 
 its connection with particular districts depending apparently more on this 
 feature than on the meteorology, though the great variability of this latter 
 exercises some influence. 
 
 In the last forty years the death-rate from phthisis in the United Kiag- 
 dom has diminished to half, principally from the more efficient soil drainage 
 and the various measures enforced by the Legislature to improve the health 
 of the working classes. 
 
 Nevertheless, the fact of the great prevalence in Great Britain and Ire- 
 land, and its rarity in many dry countries, points to some favouring influence 
 to the development of phthisis in the climate of this part of the world which 
 must be partly ascribed to its elements of damp and frequent change. With 
 
218 HYGIENE 
 
 reference to the treatment of phthisis, the writer's statistics ' of 243 patients 
 treated at the various health resorts on the south coast showed conclusively 
 that the more easterly the station the greater the amount of local and general 
 improvement to be derived, and that, for instance, Hastings gave far better 
 results than Torquay or Penzance, and that Bournemouth and Ventnor 
 occupied a position intermediate between these in improvement of patients. 
 
 Sea Voyages 
 
 The subject of the climate of the sea falls naturally under the heading 
 of Marine Climate, and we here propose briefly to consider the question of 
 sea voyages in their relation to health. Eattray's - important observations on 
 the crews of various ships of the Koyal Navy during voyages in different 
 climates, show that life at sea is by no means an unmixed blessing, and that 
 the tropics should be avoided by the natives of colder and temperate 
 climates, especially by the young, as also by weakly patients or those sujBfer- 
 ing from chronic disease. Eattray also shows that healthy adults should 
 not remain too long in tropical climates, and should leave them at once 
 if strength and flesh begin to fail ; and that the avoidance of other weaken- 
 ing influences, such as a faulty diet, over-fatigue, and impure air, which are 
 not uncommon cojicomitants of a seaman's life in the tropics, is absolutely 
 necessary to preserve health. The most striking result of Eattray's obser- 
 vations was the loss of weight by able-bodied seamen under the combina- 
 tion of the tropics and salt diet, which occurred in 81*55 per cent., each 
 losing, on an average, 4 lbs. When muscular exertion was added, the 
 percentage of losers exceeded 91 per cent., who, in 104 days, lost, on an 
 average, 7 lbs., the ship boys not losing so much as the men. Eattray also 
 comments on the wonderful improvement always noted when the crews 
 reached temperate climates, so that he sums up with the conclusion that, to 
 preserve health, a tropical climate should be frequently changed for the more 
 temperate ones of the higher altitudes or latitudes. 
 
 Eattray's careful observations on the crews show that in the tropics the 
 mine decreases from 69^ per cent, to 42 per cent., and that the perspiration 
 increases from 8^ per cent, to 30 per cent. There was a diminution of 4^ 
 per cent, in the fluid exhaled by the lungs, and a slight increase in that 
 secreted from the bowels. The kidneys appeared to be the principal elimi- 
 nators of surplus water, both in the tropics and in temperate climates, but the 
 skin was most worked in the tropics and the lungs in the temperate climes. 
 
 It is evident, then, that for sea voyages to be profitable, a long sojourn 
 in the tropics must be avoided ; and this has greater bearing on invalids 
 than on healthy people. The writer's^ statistics of a number of consump- 
 tives who took sea voyages to the Cape and Australia were very favourable, 
 but it should be stated that by far the larger proportion of these patients 
 (72 per cent) were in the stage of lung tuberculisation, and but few had 
 cavities. In 28 per cent, both lungs were affected ; 89 per cent, of these 
 patients improved ; 5^ per cent, remained stationary, and 5.V per cent, 
 deteriorated. Most of these patients undertook the voyage to Australia 
 round the Cape of Good Hope in clipper ships, not steamers, and returned 
 either by the same route or by Cape Horn. Some years ago, being anxious 
 to ascertain the exact climatic conditions of voyages, with the help of his 
 friend, Captain Toynbee, of the Meteorological Office, the writer consulted 
 
 ' Lettsonian Lectures. " Proceedings of Royal Society, 1869-72. 
 
 ' Influence of Climate on Consumption, p. 99. 
 
INFLUENCE OF CLIMATE ON HEALTH 219 
 
 the logs of the various sailmg vessels bound to Australia or New Zealand, at 
 different times of the year, and extracted such portions of their meteorology 
 as seemed hkely to prove useful to invalids. 
 
 When a ship leaves England in October, the temperature ranges from 
 52° F. to 58° F. for the first five days. Off the Azores it rises to 00° F., and 
 on passing the Canaries it reaches 70° F. On the vessel crossing the 
 equator the maximum 80° F. is attained, but this is greatly tempered by 
 breezes, as a rule. Afterwards the temperature gradually falls, and in 39 S. 
 latitude 70° F. is the average, and this sinks to 00° F. on reaching the Cape 
 of Good Hope. 
 
 After rounding the Cape, the temperature, owing to the mixture of the 
 warm Agulhas current, with cold currents from the Antarctic Circle, becomes 
 uncertain, and varies from 49°-5 F. to 00° F., the currents overlapping each 
 other and causing much variation of temperature in the superincumbent at- 
 mosphere. The vessel reaches 45° S. latitude and steers eastwards, the ther- 
 mometer ranging between 40° F. and 50° F., owing to the nearness of the 
 Antarctic Circle. When 70 E. longitude is attained, the temperature remains 
 steadily above 50° F., and rises to 06° F. on approaching the continent 
 of Australia. Throughout the voyage the temperature may be said to vary 
 between 40° F. and 80° F. The number of rainy days is about twenty. The 
 atmosphere is a moist one ; the hygrometer gives an average of 2° F. to 5° F. 
 difference between the bulbs, which, considering the high temperature of some 
 portion of the route, shows considerable humidity. The voyage, when com- 
 menced in May and ended in August, does not differ very much in temperature 
 from that commenced in October. The temperature of the equator, then, is 
 85° F., but the other records are much the same, only the traveller has the 
 disadvantage of landing in Australia in mid-winter. The return voyage from 
 Australia or New Zealand to England is seldom by the Cape of Good Hope, 
 but usually round Cape Horn, and consequently the vessel's course is further 
 southward, and approaches more closely to the Antarctic Circle. It is here 
 that low temperatures are met with, and the thermometer, which was 
 55° F. off New Zealand (Welhngton) in April, fell to below 40° F., and for 
 28 days the temperature ranged between a few degrees below 40° F. and a 
 few degrees above it, with a south wind from the Antarctic regions. How- 
 ever, in 40° S. latitude, a rise to 50° F. takes place, and off Monte Video it is 
 70° F. and 80° F. at the equator, and England is reached the middle of July. 
 
 The Australian or New Zealand voyage occupies about three months in 
 a clipper, or from 37 to 45 days in a steamer, the former being preferable 
 for health purposes. According to Dr. Maclaren, the first influence of the 
 outward voyage on the invalid is a sedative one, but on approaching the 
 Cape, the cooling atmosphere and the fresh breezes exercise a tonic eft^ect, 
 and improvement of appetite and gain of weight take place. A shortened 
 edition of this voyage is the one to the Cape of Good Hope, occupying about 
 three weeks in a steamer ; it is a good method of escaping part of the 
 British winter, as, with a halt at Cape Town or Wynberg, it occupies about 
 two months. 
 
 Other winter voyages which can be recommended are those to the West 
 Indies by the Eoyal Mail Steam Packet Company's steamers, which touch at 
 most of the islands and several of the ports of Central America, the trip 
 occupying from six weeks to four months, spent mostly in mild regions ; but 
 it is doubtful whether Eattray's objections to long sojourns in the tropics do 
 not apply here, and this voyage would not be advisable for the young. 
 
 Another salutary trip is the Brazihan voyage, where the vessel touches 
 at Lisbon, Teneriffe, Pernambuco, Bahia, Eio de Janeiro, Monte Video and 
 
220 HYGIENE 
 
 Buenos Ayres, and occupies two to three months. Here temperate climes 
 are intermingled with the tropics much to the traveller's benefit. 
 
 Far different in its meteorology and in its results on invalids is the voyage 
 to India and China, through the Suez Canal and Eed Sea, for here we get' 
 sudden transitions from extremes of temperature, which are most pernicious. 
 The increased heat in the Suez Canal and the still greater rise in the Red 
 Sea, where the thermometer often marks 98° F., combined with great dry- 
 ness, the wet and dry bulbs showing a difference varying from 8° to 12° F., 
 acts most injuriously on the appetite and strength and Hesh of patients, and 
 the temperature of the climate of the Indian Ocean (79° to 81° F.) is too 
 high to promote health. On the return voyage, too, the passing from the 
 hot atmosphere of the Eed Sea into the cooler ]\Iediterranean climate, 
 especially if the Tramontana be blowing, checks perspiration and often 
 induces temporary albuminuria.' The writer has, moreover, known more 
 than one consumptive perish in the Eed Sea from the overpowering influence 
 of heat, inducing diarrhoea ; and the depressing effect on constitutions 
 already weakened by disease is most disastrous. 
 
 Sea voyages, if the right season and route be chosen, are productive of 
 much good, as they are a means of supplying patients with abundant fresh 
 air without fatigue, and the atmosphere is rich in ozone and free from dust 
 and germs. As long as the weather is fine and the invalid lives, and even 
 sleeps, on deck, all is well, but when bad weather confines him to his cabin, 
 a very different state of affairs prevails, for he may be doomed to imprison- 
 ment in what in his own house he would designate a cupboard, and which, 
 when the portholes are closed, as during storms, often proves a very ill-venti- 
 lated one. Also the lack of proper exercise, except walking the deck, and 
 occasionally the chance of running short of provisions, are serious drawbacks. 
 
 Sea voyages have proved most useful in checking the tendency to haemor- 
 rhage, in promoting sleep, and are, therefore, very beneficial where the brain 
 and nervous system have been overworked, and in checking chronic discharges, 
 such as from fistula, strumous abscesses, and old ulcers, and in assisting 
 antiseptic treatment. The appetite is greatly stimulated on board ship, and, 
 as a rule, the larder is well supplied, and consequently food is consumed in 
 abundance, and large gain of weight, often amounting to one or two stone, 
 follows. Sometimes too great indulgence is given to the appetite, and this 
 excess, combined with want of exercise, promotes biliousness and dyspepsia, 
 which are by no means rare on board ship. Often another bad practice 
 springs up on board — viz. drinking, in most cases pursued through want of 
 occupation, and this often ruins the prospects of an otherwise promising 
 patient. 
 
 Mountain Climates 
 
 This division is characterised by diminished barometric pressure, increased 
 diathermancy, and by great extremes of temperature. So many of the lead- 
 ing features of these climates have been alluded to already, that it will not 
 be necessary to treat of them as fully as has been done in the case of the 
 other four groups, but we must say a word on some of their striking qualities. 
 In addition to being distinguished by rarefaction and diathermancy of atmo- 
 sphere, they are strongly aseptic, and this is shown by the long period that 
 meat keeps in the mountains before undergoing decomposition. They are 
 
 ' An intelligent surgeon in the service of the Peninsular and Oriental Company informed 
 me that, on testing the urine of the healthy passengers after entering the Mediterranean 
 from the Canal, he found albumen in all. 
 
INFLUENCE OF CLIMATE ON HEALTH 221 
 
 also very dry, especially during the winter months, though this is partly due 
 to air at a low temperature being incapable of holding moisture in suspension. 
 Absorption of atmospheric oxygen by the blood takes place more readily, 
 while, at the same time, the carbonic acid formed within the body passes out- 
 ward through the pulmonary tissue into the air, which is inhaled with a 
 greater degree of facility than at lower altitudes (Marcet). 
 
 One of the greatest arguments in favour of mountain climates is the well- 
 known immunity from the greater number of diseases mountaineers enjoy, 
 and the general vigour of body that they possess. When we contrast them 
 with lowlanders, the comparison is almost always in favour of the former, 
 who are generally taller, with broader and deeper chests, and greater powers 
 of endurance, especially in marching and walking ; these characteristics 
 are present in mountain races over the whole globe, be they the natives of 
 the Himalayas, the Indians of the Andes, the chamois hunters of the Tyrol, 
 the guides of Switzerland or the Highlanders of Scotland. The immunity 
 from phthisis, which has been so strongly insisted on by Kuchenmeister and 
 others, has not been found to be so complete as he has set forth, nor is there 
 any fixed immunity altitude for each degree of latitude, as he would infer, 
 and experience has shown that unhealthy modes of life, insufficient food, ill- 
 ventilated dwellings, and pernicious habits will produce phthisis at any altitude 
 or in any latitude, but that, if these are avoided, undoubtedly an altitude of 
 5,000 to 6,000 feet above sea-level will exercise a decidedly protective in- 
 fluence against phthisis, even in those predisposed to that disease. The only 
 diseases which the mountain climates can be said to produce are the so-called 
 ' mal des montagnes,' already described, and a form of dry pleurisy, known 
 in the Alps as Alpenstick ; but while they largely benefit phthisis and other 
 strumous affections, they are injurious and consequently contra-indicated 
 in the following : (1) emphysema ; (2) chronic bronchitis and bronchiectasis ; 
 
 (3) diseases of the heart and great vessels, of the kidneys, and of the liver ; 
 
 (4) diseases of the brain and spinal cord, and all states of hyper-sensibility 
 of the nervous system ; (5) the catarrhal and laryngeal varieties oi phthisis, 
 as well as erethric phthisis, when there is great irritabihty of the nervous 
 system, and all cases of advanced disease of any kind. 
 
 On the other hand, the benefit of moimtain climates is immense in the 
 following : (1) cases of strong hereditary predisposition in which phthisis is 
 either threatened or is in a state of early development; (2) imperfect 
 thoracic or pulmonary development ; (3) hemorrhagic phthisis ; (4) chronic 
 tubercular phthisis in its various stages, provided the lung-surface be not too 
 largely involved to admit of proper aeration at high altitudes, and there be 
 no pyrexia ; (5) chronic pleurisy, where the lung does not expand after the 
 removal or absorption of the fluid, and chronic pneumonia, without bronchi- 
 ectasis, that does not resolve ; (6) anemia ; (7) and spasmodic asthma with- 
 out any considerable amount of emphysema. 
 
 Another point to bear in mind is, that no patient should attempt high 
 altitude climates who cannot take exercise, and abundant exercise, and 
 therefore the aged and very feeble are clearly debarred. 
 
 Though among the mountain ranges of the globe we have plenty of choice 
 of elevation, the number of stations suitable in the way of height, shelter, 
 latitude, and accommodation is limited, and they are the following : 
 
 1. The Alpine, varying in height from 4,771 feet to 6,000 feet, with a 
 winter mean temperature of about 28' 1° F., great extremes of climate, and 
 fifty-two rainy or snowy days ; the principal stations being St. Moritz 
 (6,090 feet), Davos (5,200 feet), Maloja (5,941 feet), Wiesen (4,770 feet), and 
 Andermatt (4,738 feet), in Switzerland. The winter climate is very cold, 
 
222 HYGIENE 
 
 dry, and calm, but the sun's rays are most powerful, as sllO^\1lby the tamiing 
 of the skiu. 
 
 2. The Rocliy Mountains sanitaria of North America, varying in altitude 
 from 5,200 to 9,000 feet, the climate resembling that of the Alpine resorts, 
 but warmer, drier, and with less snow, but more dust. The stations in 
 Colorado are Denver (5,200 feet), Colorado Springs (0,000 feet), Manitou 
 Springs (6,370 feet) Poncha Springs (9,000 feet), Waggon Wheel Gap 
 (9,000 feet), Elkhorn (7,500 feet). Palmer Lake (7,2R8 feet), Yellowstone 
 National Park (0,000 feet), and Santa Fe (7,013 feet), Silver City (5,890 feet), 
 and Mesilla Valley (4,000 to 7,000 feet), in New ]\Iexico. 
 
 3. The sanitaria of the Andes, of altitudes varying from 8,000 to 13,500 
 feet, and owing to more southern latitude enjoying warmer and more equable 
 climates than the above and in many cases a mean temperature of 00'' F. at all 
 seasons : Santa Fe di Bogota (9,000 feet), in New Granada ; Quito (10,000 
 feet), Equador ; Jauja (18,000 feet), Tarma (10,028 feet), and Huancayo 
 (10,718 feet), in Peru ; La Paz (18,500 feet), in Bolivia. Chmate generally 
 dry, warm, and bracing, except at La Paz, where the winter is cold. 
 
 4. Himalaya and other mountain stations, of altitudes varying from 3,000 
 feet to 8,000 feet. Himalayan 4,000 feet to 8,000 feet. Eainfall 70 to 132 
 inches. Mean temperature 00° to 70° F. Darjeehng, Simla, Landour, and 
 Nynee Tal, Nilghiri sanitaria, with an altitude of from 5,000 to 7,000 feet, 
 mean temperature from 54° to 70° F., and rainfall from 50 to 60 inches. 
 The climate is cool, but subject to considerable extremes, and damp owing to 
 the excessive rainfall. 
 
 5. The South African Highlands of Cape Colony, Orange Free State, and 
 Transvaal, containing various stations of altitudes from 4,000 to 6,000 feet. 
 Taking Bloemfontein as a type, the climate is warm, with seldom any extreme 
 of cold even in winter, and delicate persons sleep in the open all the year 
 round, except during the rainy season and a few days of winter. The average 
 minimum is 55° F., the average maximum for the six hot months 82° F., 
 the humidity 55 per cent., the rainfall seventeen inches, and the number of 
 rainy days seventy. Li the Karoo districts of the Cape we have as suitable 
 stations for invalids Aliwal North (4,848 feet), Turkestan (4,280 feet), 
 Dordrecht (5,200 feet), and Burghersdorft (4,650 feet) ; in the Orange Free 
 State, Bloemfontein (4,540 feet) ; and in the Transvaal, Pretoria (4,007 feet), 
 and Johannesburg (5,000 feet). In South Africa it is not only the splendid 
 chmate which benefits the visitors, but the mode of life pursued by most 
 of them : i.e. living on the trek in a waggon, shooting their food-supply by 
 day, and sleeping in the open at night. 
 
 Though these groups vary considerably in climate as regards temperature 
 and moisture, they all agree in the reduction of the barometric pressure, and 
 this is the essential feature of the whole series, and the use of them in the 
 treatment of different forms of chronic disease has produced most astonishing 
 and beneficial results, which will probably increase as the number of high 
 altitude sanitaria are multiplied. In the treatment of consumption, the writer 
 has shoAvn from his statistics that out of 141 cases of phthisis thus treated 
 74-82 per cent, improved, and among these arrest of the disease took place 
 in 44 per cent., and deterioration in only 21^ per cent. 
 
 The statistics of Dr. Hermann Weber and Dr. Denison (of Colorado) 
 confirm this conclusion. 
 
WATER 
 
 BY 
 
 THOMAS STEVENSON, M.D., and F.R.C.P. (Loxd.) 
 
WATEE 
 
 Water is one of the prime necessaries of life, and ranlcs next to air in the 
 influence which it exercises upon the processes of animal life. Some 
 physicians would, indeed, contend that morbific influences are more often 
 conveyed through the instrumentality of water than by the atmosphere. An 
 adequate knowledge of the properties of water in its various physical states 
 of solid, liquid, and vapour, and especially of its solvent action on gases and 
 on saline bodies, is all-important to the health officer ; to whom also the 
 impurities present in natural water-supplies are matters of the greatest prac- 
 tical interest. Our existing knowledge of the eflects of these impurities 
 upon human beings is considerable, though still very imperfect ; but the 
 means at our disposal for detecting, quantitatively estimating, and appraising 
 at their proper value such impurities, in spite of the numerous and extended 
 published researches of chemists and biologists, are comparatively limited. 
 Yet when we contrast the knowledge which we possess, in this respect, of 
 water with that of the atmosphere and the soil, it may safely be asserted that 
 we have as complete information respecting the composition and properties 
 of the constituents of our domestic water-supplies as we have of the air we 
 breathe, and of the soil on which we dwell. We may soon expect, moreover, 
 to be in the possession of fuller knowledge of the bacteriology of water- 
 supplies — a branch of science inseparably associated with the bacteriology of 
 the atmosphere and the soil. From the study of the minute organisms 
 habitually and occasionally present in air, water, and soil, it may be expected 
 that great advances in sanitary science will accrue. 
 
 To the chemist, water, long believed to be an element or simple substance, 
 is now known to be a compound of oxygen and hydrogen, in the proportions 
 of eight parts by weight of oxygen to one part of hydrogen. Below 0° C. 
 (32° F.) it forms a sohd body (ice) ; above 100° C. (212° F.), under the ordi- 
 nary barometric pressure of 30 inches, or 760 millimetres nearly, it exists as 
 a gas (steam) ; whilst at all intermediate temperatures it forms the liquid, 
 water, ^ar excellence. During its passage from the hquid to the sohd state — 
 i.e. during the act of freezing, at 32° F. — water suddenly expands to the extent 
 of 8^ per cent, of its hquid volume, so that ice at its melting point is specifi- 
 cally lighter than water at the same temperature (water at its freezing 
 point), floats upon it, and has the specific gravity 0'9168 when compared with 
 water at the same temperature. Water in freezing gives off a large amount 
 of heat, which is again absorbed or becomes ' latent ' during the subsequent 
 liquefaction of ice ; and these absorptions and emissions of heat durmg thaw- 
 ing and freezing play a great part in tempering the severities of climate, and 
 in preventing the otherwise sudden destructive changes in the temperature of 
 the atmosphere which would otherwise ensue. 
 
 Another important physical property of water is its anomalous expansion 
 
 whilst undergoing changes of temperature. Water whilst passing from its 
 
 freezing to its boiling temperature at first contracts until the temperature 
 
 of 4°C. (39°*2 Fahr.) is reached; and this is the temperatm'e at which the 
 
 VOL. I. Q 
 
226 HYGIENE 
 
 liquid attains its maximum density. Above 4° C, it expands with rise of 
 temperature until its boiling point is reached. The important bearing of this 
 anomalous expansion is, that when a mass of water — e.g. that in a pond — is 
 cooled by radiation at its surface, the cooler surface water becomes denser 
 than the warmer water beneath, and hence sinks until the whole mass of water 
 is cooled down to 4° C. (39°-2 Fahr.) nadiation still going on, the surface 
 water now cooled below 4°, no longer sinks, but being specifically lighter 
 than the warmer water beneath remains on the surface, till, the freezing 
 point being attained, the liquid freezes, and the solid crust of ice formed in 
 a measure protects the water beneath from the influence of cooling currents 
 of air. This fi-eezing of deep masses of water at the surface, and the main- 
 tenance of the subjacent water in winter at a temperature approxunating 
 lo 39° Fahr., serves to maintain the processes of animal life in the aquatic 
 organisms met with in ponds, lakes, and reservoirs of water generally. 
 
 The disintegrating action of water upon rocks and soils is largely due to 
 the irresistible expansive force exerted by water during its solidification ; for 
 in this process, as has been already stated, water expands by about one 
 twelfth of its bulk, and the ice formed is practically incompressible. Hence 
 the hardest rocks are rent asunder by freezing water. A familiar instance 
 of the force exerted by water during its solidification is seen in the bursting 
 durmg a frost of the leaden pipes ordinarily used for the distribution of 
 domestic water-supplies. Thick leaden pipes may be thus ruptured when 
 the freezing water lies stagnant withm them ; and when a thaw sets in, the- 
 plug of ice which has filled in and closed the rent during the frost, liquefies, 
 and the resulting leakage at once reveals what has happened. 
 
 Water boils at a temperature varying with the atmospheric pressure. 
 When tliis is normal, i.e. equal to the pressure of a column of mercury of 30 
 inches, or nearly 760 millimetres in height, the boiling point is 100° C. or 
 212° Fahr. On the tops of mountains where the pressure is less than 30 
 inches of mercury the boihng point is lowered ; and conversely at the bottom 
 of deep mines the boiling point is appreciably higher than 100° 0. 
 
 At all temperatures above its boiling point water forms a transparent, colour- 
 less, invisible gas. In passing from the liquid to the gaseous state, it absorbs 
 a large amount of heat without becoming hotter (latent heat of vaporisation) ; 
 and it is this absorption of heat which causes the coohng effect of the evapor- 
 ation of surface water to exert an important influence in meteorology and in 
 the modification of climate. The great specific heat of water as compared 
 with other liquids — i.e. the relatively large amount of heat required to change 
 its temperature — has also a most beneficent effect in preventing sudden 
 changes of temperature. 
 
 Water evaporates at all temperatures, and the evaporation of solid water 
 in the form of ice and snow is an obvious and famihar phenomenon. The 
 tension of water- vapour, or its tendency to evaporate at any given tempera- 
 ture is treated of elsewhere (see Meteoeologt, p. 164). The relative satura- 
 tion of air with aqueous vapour is termed ' humidity ' of the atmosphere, and 
 bears no direct relation to the quantity of aqueous vapour therein. 
 
 The atmosphere forms a vast storehouse or reservoir for water, where it 
 for the most part exists in the form of invisible gas or vapour ; and a never 
 ceasing silent process of distillation is going on around us. This process^ 
 effected by the heat of the sun's rays, is unceasingly providing the surface of 
 our globe with fresh and pure water, which again is as constantly becoming 
 polluted by its passage over and through organically polluted soils. It is 
 commonly stated that the atmosphere contains a variable amount of aqueous 
 vapour ' dissolved ' in it ; but it would perhaps be more correct to say that the 
 
WATEB 227 
 
 atmosphere is a variable mixture of the gases, oxygen, nitrogen, carbon dioxide, 
 and water. When such a gaseous mixture is cooled, its capacity to retain 
 water in the gaseous state is diminished, and droplets of liquid water are 
 deposited on cold solid bodies in the form of dew. In other words, the 
 vapour-tension of water rises with increase of temperature. 
 
 In the British Isles the amount of aqueous vapour in the atmosphere ranges 
 from two grains per cubic foot of air in winter to twelve grains in summer, or 
 from one third per cent, to two per cent, by weight. Our atmosphere is 
 therefore, as has been already stated, a huge storehouse into which pure gaseous 
 water evaporates under the heating influence of the sun's rays, to be again 
 precipitated as rain, hail, or snow ; and thus in the vast laboratory of nature 
 there is provision for a constant supply of pure water. Were it not for this 
 unceasing process of distillation, our water-supplies would speedily become 
 so highly charged with impurities as to become unfitted for the maintenance 
 of animal life. 
 
 Water is the most universal known solvent. It dissolves, or retains, all 
 the known gases ; and it also dissolves or takes up all known solid bodies, 
 except perhaps the' diamond and some of the noble metals. Even the most 
 refractory minerals — commonly termed ' insoluble ' — gradually yield to the 
 solvent action of water, an action often greatly aided by the gases dissolved 
 in all natural waters. Thus, for example, sulphate of barium or heavy spar, 
 one of the most insoluble known chemical substances, dissolves in water to the 
 extent of one part in four hundred thousand parts by weight, or one sixth of 
 a grain per gallon. It is in this way that rain-water becomes charged with the 
 gaseous constituents of the atmosphere, viz. oxygen, nitrogen, and carbon 
 dioxide gases ; and to a less extent with ammonium nitrate and other so- 
 called sohd impurities. Thus also water in flowing over and percolating 
 through the soil takes up from this, or dissolves, additional quantities of car- 
 bonic acid, since the soil is always richer in this gas than the air above it : 
 also the more or less soluble mineral constituents of the soil — notably the 
 carbonates of calcium and magnesium, sulphates, chloride of sodium, and 
 other saline matters. Thus, again, streams and rivers are the silent conduits 
 by which the solid crust of the earth, partly dissolved and partly in a state of 
 mechanical suspension, is carried seawards and there deposited in the form of 
 new rocks, or retained in solution. 
 
 Absolutely pure water, in the chemical sense of the term, is a substance 
 of extreme rarity, and has only been obtained by repeated distillations of 
 fairly pure water in vessels constructed of silver. Water, when retained in 
 contact with surfaces of porcelain or glass, quickly takes up small quantities 
 of solid impurities owing to its solvent action upon the silicates of which such 
 vessels are constructed. 
 
 In the following pages we shall have to treat of water, not in its che- 
 mically pure, but in its natural state ; and in speaking of a pure water, the 
 sanitarian means a water practically free from noxious gases, from injurious 
 organic matters, from injurious metallic constituents, and containing no 
 excess of mineral ingredients, albeit charged with moderate quantities of 
 ordinary innocent saline matters, and well aerated. We shall consider the 
 sources of our water-supplies ; the collection, storage, and distribution of 
 water ; its impurities, their influence on health, and their removal ; the 
 quantity of water requisite for domestic and other purposes ; the means at 
 our disposal for determining its purity or impurity ; and the constituents 
 generally present in water. The permissible limits of the various constituents 
 and impurities of potable water-supplies will also have to be stated, so far 
 as existing knowledge permits us to do so . 
 
 q2 
 
228 HYGIENE 
 
 SOURCES OF WATER-SUPPLY 
 
 The sources of water-supply are very varied ; but they may be classified 
 as follows, each clasi of water having its own special characteristics. All 
 waters are, however, as has been already stated, idtimately derived from that 
 vast mass of naturally distilled water which descends through the atmo- 
 sphere in the forms of mist, dew, rain, hail, and snow. In addition there is 
 water artificially distilled, as on ship-board and in tropical regions, ap- 
 proximating in its characters more to rain-water than to any other natural 
 water, 
 
 I. Bain-%oater, which, after being collected on the roofs of buildings and 
 other more or less flat surfaces, is stored in appropriate receptacles. This 
 when collected, with due care, on clean surfaces in country districts, is in one 
 sense the purest natural water. That collected in and near towns and 
 factories is generally too impure to be fit for drinking purposes. 
 
 II. Upland water, or surface water, which having fallen on a sparsely 
 populated and but little cultivated soil is collected in ponds, lakes, or 
 artificial reservoirs, and stored for use. Such waters, as a rule, contain 
 very little dissolved saline matter ; though they may contain a good deal 
 of dissolved peaty matter, rendering them brown in colour and bitter in 
 taste. 
 
 III. Spring and ivell-zvaters. Here the rain-water has percolated to a 
 greater or less depth into the soil and subsoil, and is by the pressure or ' head ' 
 of superjacent water in the soil forced to the surface through holes and fissures 
 (spring- water) or into holes sunk into the earth (well-water). Spring and well- 
 waters belong practically to the same class. They vary very greatly in their 
 composition, according to the nature of the subsoil whence they are derived. 
 Springs and deep wells usually afford hard, sparkling waters ; whilst shallow 
 wells commonly afford bad and organically impure waters. 
 
 IV. Bivers are fed by surface water, waters from land drainage, and by 
 the overflow of springs : hence they vary greatly in composition and purity. 
 Often they are largely contaminated by sewage. As a rule they furnish 
 waters less hard and saHne than the average of spring waters feeding them, 
 part of the chalk of the springs having been deposited on exposure to the 
 air, by loss of carbonic acid. When a river is large, its water generally has 
 a pretty uniform composition, except during times of flood. This is well 
 sho"ttm in the water of the Thames at the intake of the London water com- 
 panies. This water does not materially vary in the amount and proportions 
 of its various saline constituents at different seasons of the year. But it 
 must be admitted that the Thames is more largely derived from springs 
 discharging into the bed of the river than is the case with the majority 
 of British rivers. 
 
 RAIN-WATER 
 
 Eain-water varies in composition according as it is collected in the country 
 or in towns, but is never pure water. It invariably contains, besides the 
 gases of the atmosphere, nitrate and nitrite of ammonium, solid amorphous 
 and crystalline particles in suspension, and minute organisms. That of 
 towns contains the acids generated by the combustion of coal, and notably 
 sulphuric and hydrochloric acids. The aggregate amount of these two acids, 
 in the free state, may reach as much as seven grains per gallon or ten parts 
 per 100,000. Eain-water collected near the sea, and even many miles inland, 
 contains small quantities of the salts present in sea-water. Even the rain- 
 
WATEB 229' 
 
 water collected in Florence was found by Beclii to contain 0*28 grain per 
 gallon, or 0-4 part per 100,000, of solid matter, about half of which was 
 organic and half inorganic, the chief portion of the latter being sulphate of 
 calcium and choride of sodium. (' Deutsch. Chem. Ges. Ber.' viii. p. 103.) 
 Bechi also determined the amount of ammonia and of nitric acid in the rain- 
 water falling respectively in Florence, and at Vallombrosa in the Apennines, 
 more than 8,000 feet above the sea-level. At Vallombrosa the ammonia 
 was, on the average, 0-03G grain per gallon, or 0*51 part per million ; whilst 
 in Florence there was 0'078 grain, or I'll part per million. In Vallombrosa 
 the nitric acid was 0*041 grain per gallon, or 0"58 part per million, and in 
 Florence 0'083 grain per gallon or 1-18 part per million. Lawes and 
 Gilbert found the average aggregate amount of combined nitrogen in country 
 rain-water, as ammonia, nitrates, and nitrites, to be nearly 0*07 grain per 
 gallon, or one part per million. 
 
 Eain-vpater dissolves at the ordinary temperature of our country about 
 20 c.c, per litre, or 5*5 c.i. per gallon, of the atmospheric gases, of which 
 about 7 c.c. per litre, or nearly 2 c.i. per gallon, is oxygen ; 12*5 c.c. per litre, 
 or 8*5 c.i. per gallon, is nitrogen ; and 0'5 c.c. per litre, or 0*14 c.i. per gallon, 
 is carbon dioxide gas. But rain-water is rarely, if ever, fully saturated with 
 oxygen, this gas being in part appropriated by the organic matters present 
 in the water ; so that the oxygen rarely exceeds 1"75 c.i. per gallon or 6*3 
 c.c. per litre. 
 
 The following may be taken as the average composition of rain-water 
 collected in inland districts remote from towns : — 
 
 Grains Parts 
 
 per gall. per 100,000 
 
 Saline constituents 2-1 3"0 
 
 Combined nitrogen 0"07 O'l 
 
 The Eiver Pollution Commissioners in their sixth report, issued in 1874, 
 give the following as the gaseous constituents of rain-water : — 
 
 c.i. per gall. C.c. per litre 
 
 Nitrogen 3-63 lB-08 
 
 Oxygen 1-77 6-37 
 
 Carbonic acid 0^35 1-28 
 
 Total gases . . . 5-75 20-73 
 
 When rain-water has to be collected from buildings and stored for drink- 
 ing purposes, special precautions must be taken to ensure its cleanliness and 
 freedom from metallic compounds and from organic impurities. For this 
 purpose it should never be collected from surfaces of lead, and even roofs 
 covered with sheet zinc or galvanised iron commmiicate some zinc to the 
 water collected on them. Eoofs covered with slate afford the best collect- 
 ing surfaces for rain-water. The first water collected after dry weather is 
 always dirty, polluted with the excrement of birds, and contains vegetable 
 spores. 
 
 Mr. Charles Gay Eoberts has designed a very ingenious and effective sepa- 
 rator (figs. 82 and 83) (p. 280) for automatically getting rid of the first and 
 dirty rain-water falling after drought. 
 
 A vertical separator is used where a single stack pipe carries the water 
 from the roof to the tank. 
 
 In figs. 82 and 83, the front of the vertical separator has been removed to 
 show the interior. Fig. 82 shows it in the position that it retains when 
 running foul water into the waste pipe during the first part of a shower, while 
 the roof is yet dirty. Fig. 83 represents it when it has canted and has 
 begun to run pure water into the storage tank, after the roof has become 
 
230 
 
 HYGIENE 
 
 clean. The change of position is effected by the gradual accumulation of a 
 small portion of the water in the chamber J of the canter ; when the water 
 reaches a certain height, it makes the left side heavier than the right, and 
 the canter turns a little on the pivot m that supports it, so that the water is 
 delivered two inches further to the right than it was before ; and whereas it 
 at first ran through n into the waste pipe, it now runs through o into the 
 storage tank. 
 
 In figs. 82 and 83, A A are strainers removable for washing, b is a remov- 
 able slide, with two small holes to regulate the fiow of sufficient water to work 
 the canter, c is a sluice to be adjusted to the area of the roof, d is the outlet 
 
 FOUL 
 
 Fk;. 82. — Section of vertical separator 
 iini^ure water passing to waste. 
 
 FOUL. 
 
 FiG. 83. — Section of vertical separator: 
 pure water passing to storage. 
 
 for surplus water. In moderately heavy rain the main volume of the water 
 flows through this spout d into the deli-s^ry pipe e, rumiing round the right 
 hand of the canter ; a small proportion only passes through the strainer and 
 out of the small holes b into the funnel f that terminates in the small 
 hole G. 
 
 In a very slight rain the whole of the water passes through the strainers 
 and the hole at b into f, and when it is not enough to effectually wash the 
 roof it all escapes through g without making the canter move. When there 
 is more rain than can pass through the hole G, it rises in f and L, and a small 
 quantity runs over the side of the funnel, slowly filling the chamber j. When 
 J is filled to a certain height, it overbalances the canter and makes the water 
 rmi to storage through o, as shown in fig. 83. This change in position causes 
 
WATER 231 
 
 the water from b to run into t, and cease to run into f. As the water sinks 
 in F it also sinks in l, causing the siphon k to act and empty the chamber j. 
 Meanwhile some of the water from t will have been running through the 
 pipe V into the little chamber w, and the weight of this water will prevent 
 the canter recanting until the water ceases to run from the roof. 
 
 As soon as w is empty, the canter rights itself, ready for the next rainfall, 
 the right-hand side of the canter being heavier than the left when it is empty. 
 By means of the joint action of the sluice c and the holes at B and g, the 
 flow of water in the working part of the separator is so regulated that the 
 ■chamber j is filled to the canting point as soon as a certain quantity of rain 
 has fallen. 
 
 One of the chief defects of a rain-water supply is its scantiness and uncer- 
 tainty. A rainfall of 25 inches per annum is equal to 2,523 tons per acre, or 
 665,380 gallons yearly ; and even if this were all collected and stored without 
 loss, it would suffice for 62 persons only, each person being allowed 25 gallons 
 per diem. During times of drought, when evaporation is usually great, it is 
 manifest that a rain-water supply must be deficient, except where only a small 
 number of persons has to be supplied. 
 
 In Venice, where there is a considerable rainfall, where ordinary wells are 
 impossible, and where there are neither roads, nor horses or other draught 
 animals, and where all the circumstances are apparently favourable, the 
 water-supply for drinking purposes was until recently derived from rainfall. 
 The water was collected from all available gathering areas and discharged 
 into underground tanks filled with sand. The water was thus filtered during 
 its passage through the sand, into which tubes or little wells with impervious 
 sides are sunk, and reach nearly to the bottom of the sand. The water was 
 pumped through the tubes in a clear condition. This system is one of down- 
 ward filtration of a simple, and it is said of effective character. 
 
 If rain-water is to be used for drinking purposes, it should always after 
 collection be filtered through sand and charcoal, or other equivalent material, 
 so as to remove suspended matters, before storage ; and should then be kept 
 for some time in carefully covered and well-aired tanks or cisterns, lined with 
 slate or other impervious non-metallic material. A good plan is to pass the 
 water from a Eoberts' separator through a conduit sufficiently wide to con- 
 siderably diminish the velocity of the current, and over a catch-pit which 
 will retain the grosser suspended particles. The conduit should then make 
 a considerable dip, so as to deliver the water at the bottom of the filter, though 
 it should pass in an upward direction to an effluent pipe conveying the filtered 
 water into a covered slate-lined tank. The filter may consist of successive 
 layers of coarse sand ; charcoal, magnetic carbide, or other equivalent puri- 
 fying material ; coarse gravel ; and sand. 
 
 "When iron tanks and pipes are used for the storage and distribution of 
 xain-water, the metal becomes rapidly corroded ; and no useful purpose appears 
 to be served by coating the iron with zinc (galvanising) ; for the zinc is quickly 
 removed, and the water becomes turbid with zinc compounds, and even 
 contains this metal in solution. This zinc-caused turbidity persists until all 
 the coating of zinc has been removed. 
 
 The following approximately correct rules are useful as to rainfaU, and 
 yield of rain water : — 
 
 The rainfall in the wettest year is double that of the driest year. 
 
 The fall in the wettest year is one-third more than the average rainfall. 
 
 The fall in the driest year is one-third less than the average rainfaU. 
 
2^2 HYGIENE 
 
 Upland Waters 
 
 Many of the largo nortlievn manufacturing towns of tliis country, such as 
 Glasgow, Liverpool. ^Manchester, Leeds, Sheffield, and Keighley, are supplied 
 with upland water. Glasgow is supplied from a natural reservoir — IjocIi 
 Katrine. The new Liverpool supply is derived from a gathering ground in 
 Wales, artificial reservoirs being formed for its storage. The usual method of 
 obtaining such a supply is to impound the water flowing off from the surface 
 of a large, barren, uninhabited area of land, where commonly the rainfall is 
 high, and the amount of water that percolates through the soil small as 
 compared with that which flows oft' the surface. The water is collected 
 into streamlets, w^hich combine to form one large brook at the bottom of a 
 valley. A dam is built across this at a convenient spot, and the water is 
 headed back into the reservoir thus formed. Loch Katrine is a similar 
 natural reservoir or lake, and Lake Thirlmere, from which Manchester is to 
 receive its new water-supply, is also a similar lake, which is to be increased 
 in capacity, and its level raised fifty feet, by a dam built across one end of it. 
 The natural outlet of Lake Thirlmere is to the north, but the water for 
 ]\Ianchester is to be obtained by tapping the southern end of the lake, and 
 drawing oft' the necessary quantity of water by means of a tunnel through 
 Kirkdale Pass. In dry seasons the reservoirs will not be full. In flood- 
 time the excess of water flows over a weir at a fixed height into a ' bye wash ' 
 or side channel, and thence into the main stream. 
 
 The probable yield of a gathering ground is a very important considera- 
 tion, and the estimation of the available yield of water from a given area is 
 by no means a matter of easy solution. Mr. Bateman's views as to the 
 quantity of rainfall available for water-supply are set out in the ' Report of 
 the Eoyal Commission on Water-Supply (1809).' Where the average rainfall 
 in a mountainous district is 75 inches, he estimates that 80 per cent, of that 
 amount, or GO inches, may be taken as the average fall of two or three con- 
 secutive dry years. In such rainy districts the loss from evaporation and 
 absorption averages from 9 to 16 inches, and he adopts 12 inches as the 
 mean for North Wales. This 12 inches deducted from the 60 inches above 
 leaves 48 inches, or 64 per cent, of the total average rainfall,_ as the net 
 available rainfall Avlien the total average rainfall is 75 inches. But for 
 greater security, Mr. Bateman diminishes again the last result by 25 per cent, 
 and takes 36 inches as the estimated available proportion of the rainfall of 
 75 inches — i.e. 48 per cent, (or practically one-half), on which to base his 
 calculations. In the old Manchester waterworks, wdth an estimated rainfall 
 of a little more than half 75 inches, he states that he collected 32 inches 
 of rainfall. 
 
 Other eminent authorities think Mr. Bateman's estimate of the pro- 
 portion of available supply too high. Mr. Thomas Hawksley says it is- 
 kno^vn to be impossible, by any system of reservoirs that can be constructed, 
 to deal with more than the average of three consecutive years of minimum 
 fall. The minimum year has about one-third less than the general 
 average rainfall ; and in the three consecutive driest years the average 
 fall is almost precisely one-sixth less. Thus, with an average rainfall of 45 
 inches, he would deduct one -sixth, leaving 37^ inches as the average quantity 
 of the three minimum years, and in a district partly lowland and partly 
 highland, as, e.g., in North Wales, he would deduct 13 J, inches from the above 
 37h inches for loss by evaporation, &c., leaving 24 inches only as the net 
 available rainfall, where 45 inches is the average annual fall — or about 55 
 
WATER 235 
 
 per cent, of the whole rainfall (op. cii.). The experience of recent years has 
 shoAvn that even this estimate of Mr. Ilawksley's of net available rainfall may 
 sometimes be excessive. 
 
 Sir Eobert Rawlinson [op. cit.) considers that a deduction of one-third 
 should be made from the average to arrive at the minimum rainfall of any 
 one year. Mr. J. Gr. Symons, taking the true mean rainfall of a wet district 
 (the Lake District) as 77 inches, infers that the mean of three dry years 
 would be 80 per cent, of this amount, or 61^ inches ; but in the driest years 
 he would take only something like GG to G8 per cent. — say two-thirds — of the 
 average as the true dry season rainfall. 
 
 In this connection it may be remarked that the proportion of evaporation 
 to rainfall is very variable, and that the data afforded by observation in one 
 country or locality are inapplicable to another dissimilar district, or to a 
 country with a widely different climate. Hence the recorded results of 
 observations made are widely discrepant and irreconcilable. Formerly it was 
 held by French hydraulic engineers that evaporation always exceeds rainfall 
 (Geikie's ' Text Book of Geology,' p. 3G0), but it has been since shown 
 that, except in unusually dry years, rainfall invariably exceeds evaporation. 
 At Lea Bridge, near London, the average recorded rainfall of ten years was 
 25*5 inches, and the evaporation from the surface was 21 inches per annum 
 (Symons's * Brit. Eainfall for 18G9,' p. 162). The discharge of rivers, as 
 compared with rainfall, varies, of course, to a still greater extent than the 
 proportion of evaporation to rainfall. In the Thames basin, and in most of 
 the river basins of Great Britain, it is said that from one-fourth to one-third 
 of the rainfall is discharged by rivers. The Seine at Paris is stated to carry 
 down one-third of the rainfall of its basin, and the Mississippi is also stated 
 to discharge one-fourth of the rainfall of its collecting area, whilst the Mis- 
 souri discharges only one-sixth of the rainfall of its basin. But some 
 American rivers are computed to discharge nine -tenths of the rainfall of their 
 respective basins. 
 
 Mr. Symons has deduced from meteorological returns the general result 
 that in any given district the wettest year of a series will have in the British 
 Isles a rainfall nearly half as much again as the mean ; that the driest year 
 will have one-third less fall than the mean, and that the driest three consecu- 
 tive years will each have one-fifth less than the mean rauifall of a long series- 
 of years. Now let R.m. be the mean average rainfall, then we have : 
 
 Eainfall in the wettest year ..... 1"5 E.m. 
 
 ,, ,, driest ,, f R.m. 
 
 Mean of the driest three consecutive years . . 0-8 E.m. 
 
 Thus, if Q = daily quantity in gallons for all purposes required to be 
 supplied from the reservoir, then, E being inches of rainfall evaporated, 
 Q = 62 A (0-8 E.m. - E).' 
 
 Which gives the relation between the area of the gathering ground (A), and 
 the quantity it will supply (Q), and by substituting 150 Q for Q in wet, and 
 200 Q for Q in dry districts, we arrive at the storage capacity of the reser- 
 voirs required (' Pole on Water-Supply,' p. 24). 
 
 Characteristics of Upland Surface Waters 
 Upland surface waters may be derived from either igneous or metamorphic 
 rocks ; but the analyses made for the Eiyers Pollution Commissioners (6th 
 
 ' Mr. Pole's factor is 62-15. According to the new deteiinination (recently legalised^ 
 of the weight of a cubic inch of water at 62° F. (252-286 grains) the factor should be 61-89.. 
 I have adopted 62 as sufficiently exact. [T. S.] 
 
234 HYGIENE 
 
 Eep. 1869) show that the upland surface waters from the exposed Metamor- 
 phic, Cambrian, Sihirian, and Devonian rocks in Great Britain do not differ 
 materially in composition — except, perhaps, as to their minuter mineral 
 constituents — from those derived from the harder igneous rocks. Their 
 total solid constituents were found to range from about 1 to 9 grains per 
 gallon, the average amount being 3'5 grains. They are pure, soft waters, 
 not infrequently destitute of chalk ; and they sometimes contain free acid or 
 acid salts. Organic substances are present in small quantity, and are chiefly 
 of vegetable origin. These waters are, however, often peaty, bitter, and 
 highly coloured ; and peaty waters are prone to cause temporary diarrhoea 
 Avhen drunk by persons unaccustomed to their use. They also dissolve lead 
 freely. 
 
 The upland surface waters from the Yoredale and Millstone Grits and the 
 non-calcareous portions of the Coal Measures contain rather more saline con- 
 stituents than the above-named waters ; these varying from about 3 to 10 or 
 11 grains per gallon, according to the analyses made for the Eivers Pollution 
 Commissioners ; the average being, however, little more than six grains per 
 gallon. Those from the Lower London Tertiaries and Bagshot beds are 
 still more saline ; whilst those from the calcareous portions of the Silurian 
 and Devonian rocks contain from 8'5 to 10 grains per gallon of saline solids. 
 Those from the calcareous portions of the Mountain Limestone contain from 
 8'o to 16 grains per gallon of solid matter, and are of moderate hardness. 
 The surface waters from the calcareous portions of the Coal Measures may 
 contain as much as 38 grains per gallon of saline matter, with an average 
 of about 16 grains, according to the Eivers Pollution Commissioners (op. cit.), 
 and their hardness may be considerable. The upland surface waters from 
 the Lias, New Eed Sandstone, Conglomerate Sandstone, Magnesian Lime- 
 stone, and Oolite formations approximate in composition to those from the 
 Mountain Limestone. 
 
 The surface waters from cultivated land, when this is not calcareous, do 
 not appear to contain much more solid matter than those from upland uncul- 
 tivated soils, according to the Eivers Pollution Commissioners, who give the 
 average amounts as 4*5 and 6'5 grains per gallon respectively. It is chiefly 
 the organic impurity which, as might be expected, is increased by the culti- 
 vation and manuring of the soil. Where, however, the soil under cultiva- 
 tion is calcareous, the saline constituents of the surface water rarely fall below 
 14 grains, and may rise to nearly 80 grains per gallon. 
 
 The land drainage from a highly manured soil usually yields an im- 
 pure water. The carbonic acid formed during the decomposition of organic 
 matters, whether animal or vegetable, greatly increases the solvent action 
 of these waters upon calcareous matter. 
 
 Water stored in large lakes is, as a rule, potable, safe, and little liable 
 to serious pollution from animal matters ; but that from very small lakes 
 and ponds is often more largely contaminated, since the proportion of 
 sewage and drainage from manured land is great in proportion to the volume 
 of the effluent water. A vexed question relates to the decomposing 
 vegetable matter and the organisms of pond life both of animal and vegetable 
 nature, usually present. The minute vegetable organisms — often invisible 
 to the eye — present in such waters often render it difficult to store such 
 waters without offence ; and under these circumstances such waters cannot 
 be considered to furnish satisfactory supplies. These waters are generally 
 satisfactory when carefully filtered ; but they are apt to clog the filters, 
 which require careful management and frequent renewal of the filtering 
 medium. 
 
WATER 235 
 
 It has been stated that water abounding in certain forms of algfe has 
 proved fatal to the animals which drank of it. 
 
 It may be useful to summarise what has been stated as to upland surface 
 waters from various geological formations and soils as follows : 
 
 The Kivers Pollution Commissioners, 1868 {op. ciL), ascertained that 
 waters from the various geological formations of the British Islands had the 
 following composition : — 
 
 1. Upland Surface Waters from Igneous i^oc/bs.— SoUds 1-1 to 8*9 grains 
 per gallon ; average 3-6 grains. Hardness 0°-6 to 4°-l ; average l°-5. 
 
 2. Upland Surface Waters from Metamorphic, Cambrian, Silurian, and 
 Devonian i?oc/ts.— Solids 1-5 to 8*7 grains per gallon; average 3-6 grains. 
 Hardness 0°-3 to 4°-8 ; average l°-8. 
 
 3. Upland Surface Waters from the Yoredale and Millstone Grits, and 
 the Non-Calcareous portion of the Coal Meastires. — Solids 3-2 to 10*5 grains 
 per gallon ; average 6-1 grains. Hardness 0°-6 to 6°-3 ; average 3°-3. 
 
 4. Upland Surface Water from Lower London Tertiaries and Bagshot 
 Beds. — Sohds 4-1 to 9-2 grains per gallon ; average 5*9 grains. Hardness 
 l°-8 to 3°-9 ; average 2°-7. 
 
 5. Upland Surface Water from the Calcareous portions of Silurian and 
 Devonian Eoc^s.— Solids 8-6 to 10-1 grains ; average 9-6 grains. Hardness 
 5°-2 to 6°-7 ; average 6°. 
 
 6. Upland Surface Water from Mountain Limestotie. — Solids 8*7 to 16*4 
 grains per gallon ; average 11-9 grains. Hardness 6°-9 to 10°-2 ; average 8°-9. 
 
 7. Upland Surface Waters from, the Calcareous portion of the Coal 
 Measures. — Solids 7"1 to 54-1 grains per gallon ; average 16 grains. Hardness 
 4°'3 to 17°-5 ; average 8°-6. 
 
 8. Upland Surface Waters from the Lias, New Bed Sandstone, Conglo- 
 merate Sandstone, and Magnesian Limestone. — Solids 7*8 to 18"4 grains per 
 gallon ; average 13-2 grains. Hardness 4°-2 to 17°'4 ; average 9°-9. 
 
 9. Upland Surface Waterfront, Oolites. — Solids 12-2 grains per gallon; 
 hardness 8°'7 — in the one sample analysed. 
 
 10. Surface Waters from Cultivated Land in Non- Calcareous Districts.^ 
 Solids 3'7 to 12-7 grains per gallon ; average 6*7 grains. Hardness 1°'5 to 
 7°-l ; average 3°-4. 
 
 11. Surface Waters from Cultivated Land in Calcareous Districts. — 
 Solids 9"3 to 77'3 grains per gallon ; average 20*7 grains. The solids rarely 
 fell below 14 grains per gallon. Hardness 5°*5 to 47°'l ; average 14°"4. The 
 hardness rarely fell below 14°. 
 
 Spring Watebs 
 
 Springs yield water-supplies of a varied character. They may be classi- 
 fied under three heads : land springs, main springs, and intermittent springs 
 or bournes. 
 
 Land springs are springs of water formed by the percolation of water 
 through superficial porous soils, such as sand, gravel, or alluvial earth, over- 
 lying impervious strata, such as clay. Where the two strata —the impervious 
 and the pervious — crop out to the surface, or when the line of junction of 
 the two strata is tapped, aland spring appears. Such springs are frequently 
 met with in the carrying out of drainage and sewerage works, and during the 
 sinking of wells. Their yield of water is uncertain and precarious, depend- 
 ing upon the extent of available porous collecting area, which may be small. 
 They are, however, frequently replenished by the percolation from heavy 
 summer showers which do not affect deeper springs and wells ; but they 
 
230 HYGIENE 
 
 are also affected by season, the yield of water increasing durinp: the winter 
 months, October to March, and decreasing during the summer months, 
 April to September. 
 
 In adopting a land spring as a som-ce of water-supply for a house, the 
 yield of water at one particular period of the year — especially the yield in 
 the spring — cannot be relied on as to quantity. The autumn yield is a 
 safer guide to the abundance of the available supply. It is always safest to 
 gauge the spring several times during the year, and more especially during 
 the summer and autumn seasons. 
 
 Main springs are those deep-seated springs whose source is the main 
 water percolating through great thiclmesses of porous rock overlying an 
 impervious stratum ; and frequently the collecting area is remote from the 
 spring itself. These springs are chiefly met with in regular geological 
 formations, such as the chalk and green sand. When the stored-up water 
 is confined by an overlying stratum of impervious material, we have the 
 conditions requisite for the formation of an artesian well. On boring 
 through such an upper impervious stratum of rock till the water-bearing 
 stratum is penetrated, the head or pressure of water in the water-bearing 
 layers of rock may force the water up the bore-hole to a considerable height. 
 The latent spring is, in fact, tapped and made available for use. Good examples 
 
 ^^^^^^^ BOURNE 
 
 RIVER 
 
 Pig. 84. 
 
 of artesian wells are met with in the Thames Valley, and furnish excellent 
 water-supplies. On the banks of the river Wandle, near Merton in Surrey, 
 the water in such wells riges to the level of a few feet above the surface of 
 the soil, and by means of inverted J -shaped pipes is discharged in such a 
 manner as turn water-wheels. 
 
 Intermittent springs, or ' bournes,' as they are technically termed, were 
 formerly supposed to be formed by natural syphons, emptying from time to 
 time underground reservoirs of water ; but no such syphon emptying an 
 underground reservoir has ever, in fact, been discovered ; and all the 
 phenomena connected with these springs can be satisfactorily accounted for 
 on simpler principles. Such springs are usually found irear the chalk, as 
 e.q. near Croydon, and at Assendon. 
 
 In fig. 81 the dotted line represents the level of the underground water 
 in the neighbourhood of a valley traversed by a river and bounded on one 
 side by hills. This line of level rises from the river to the hills, in which 
 the water will stand at a much higher level than at the river ; this being 
 invariably the case with underground water. In winter the declivity of the 
 underground water-level will be much steeper than in summer. The 
 appearance and disappearance of the bourne will depend upon whether the 
 water-level at the spot marked ' Bourne ' comes to the level of the surface, or 
 
WATEB 237 
 
 remains beneath the hnpervious strata. Bournes nearly invariably make 
 their appearance in winter, when the level of the under j,f round water is 
 highest, and disappear in summer, when this is lowest. In 1870 there was, 
 however, a remarkable exception to this uniformity, for in that year the 
 Assenton Spring broke out in June. In 1879 the spring rains were excessive, 
 and percolation into the deeper strata of rock, which in summer is usually 
 nil, took place to large extent ; and thus the appearance of the spring in the 
 unusual month of June is readily explained. Spring- and well-waters may bo 
 classed together ; and it is among these waters that the widest differences, as 
 to the quality and quantity of their saline constituents, is encountered. 
 Waters drawn from shallow surface wells may exhibit all the characteristics 
 of surface waters from the same locality ; or, more commonly, they are 
 charged with the washings of, and percolations of surface water through, a 
 shallow soil loaded with animal and vegetable organic impurities. Waters 
 from deep springs and wells, on the other hand, are usually of practically 
 uniform temperature, whatever be the variations in the temperature of the 
 atmosphere, and when from similar soils show but little variation m their 
 saline and other constituents. With respect to their saline constituents, 
 there is the utmost variation in their composition ; and these waters may 
 vary from a fairly soft, palatable Avater, to that of a saline, chalybeate, 
 arsenical, or purgative fluid. Their freedom from organic contamination is 
 usually almost complete ; and hence, if their salinity be not too great, and if 
 they are free from more than mere traces of potent medicinal substances, 
 such waters are agreeable refreshing beverages, and are well adapted for 
 drinking purposes and for town water-supplies. Deep weU-waters, indeed, 
 yield the best water-supplies, and those to which the fewest exceptions can 
 be taken, save on the score of hardness or the cost involved in pumping. 
 The water-supply, on the contrary, from shalloAv wells is, as a rule, bad, 
 and always dangerous if the well be in the proximity of dwelling-houses, 
 middens, privies, ashpits, stables, and the like sources of contamination ; 
 for the purity of such waters is at any moment liable to be impaired by the 
 sudden irruption of organic filth and the soakage of liquids. The writer 
 has found the shallow wells of London to yield water containing as much 
 as 200 and even 300 grains per gallon of solids — hard, abounding in 
 sulphate of calcium — and yet withal clear, sparkling, and pleasant to the 
 taste. A memorable instance of an outbreak of Asiatic cholera followmg 
 the use of such a water is recorded in the classical instance of the Golden 
 Square pump, by Dr. Snow. This case will be again adverted to. 
 
 When shallow wells are sunk into an alluvial, gravelly soil, in the 
 immediate proximity of a river, they may become contaminated with filth 
 carried laterally to great distances, owing to the ' set ' of the ground-water 
 in a particular direction, generally towards the bed of a river. Such under- 
 ground streams are by no means uncommon, and, when pure, form uniform 
 and excellent supplies, such as those which have furnished water to Dresden. 
 
 Under other conditions, shallow wells should, if possible, be avoided as 
 sources of water-supply. They are very prone to be contaminated with 
 organic filth, derived from the soakage of sewage and slop-water into a porous 
 soil. It was formerly supposed that a well drains an area extending over 
 a distance in radius twice the depth of the well. No general rule can, 
 however, be laid down, and often the distance is much greater than this. 
 Such wells can never be considered safe, unless they are sunk through an 
 impervious bed of soil into a porous stratum beneath, and are well cemented 
 down to the clayey stratum. Wells which do not conform to this rule are 
 too abundant in most rural districts, and are fertile sources of mischief. 
 
238 HYGIENE 
 
 Aroimd a well, tlie surface of the ground- water in the soil will be found to 
 lake the form of a hollow inverted cone, with its apex at the level of the 
 ■water in the well, the base of the cone merging imperceptibly in the general 
 level of the adjacent ground-water. When the well is pumped, the apex of 
 the cone will be depressed, and its area will be extended — the cone becom- 
 ing flattened out. The drainage area of the well will thus be increased, and 
 if there be any cesspool, pervious sewer, or leaky drain within the area of the 
 cone, the polluting liquids will be drawn into the well by suction. Hence 
 the great danger attendant on the use of shallow wells, and all wells sunk 
 into pervious soils only. 
 
 Some years a<,^o the town of Croydon in Surrey was visited by an' 
 epidemic of typhoid fever, which was traced to the water derived from deep 
 wells. Mr. Baldwin Latham made observations which showed that when 
 the pumps were worked the level of the ground-water was lowered, and 
 sewage was sucked out of the seAvers, passing, as he alleged, into the wells 
 supplying Croydon. 
 
 Wells in proximity to the sea generally afford a saline and somewhat 
 brackish water, containing excess of magnesium and sodium salts, without 
 doubt derived from the presence of the salts of sea-water. Even when the 
 wells are sunk to a considerable depth below the level of the sea, it must not 
 be supposed that there is any appreciable direct percolation of sea-water into 
 them, for it will be found that the ' set ' of the underground water around the 
 well is towards the sea. It is more probable that the advent of sea-salts is due 
 to liquid diffusion, the salts diffusing backwards into the w^ell. If it were 
 otherwise, the water in the wells would be more than brackish, and would be 
 salt water. That sea-salts will find their way into wells situated at a great 
 distance from the sea or a tidal river, is shown by the observation of the 
 late Dr. de Cliaumont, who found in a place near the Humble Eiver in 
 Hampshire, that the tide affected the water at a distance of 2,240 feet, or 
 nearly half a mile ; the well itself being 83 feet deep, and 140 feet above 
 mean water-level. (' Lect. on State Med. 1875,' p. 91.) 
 
 Driven Wells or Tube Wells. — These are also termed Abyssinian wells, 
 in consequence of their having been used during the Abyssinian war to 
 supply water to the British troops. They are very serviceable in country 
 districts where the shallow surface wells afford polluted supplies, and where 
 a better and purer water can be obtained by penetrating through an imper- 
 vious clay into the more porous water-bearing strata beneath. Their con- 
 struction is very simple. An iron pipe, 1^ to 2 inches in diameter, is furnished 
 at its lower end with a hard steel point, above which the pipe is pierced with 
 holes to admit of the inflow of water. The pipe is driven perpendicularly 
 into the soil by means of a mallet or falling weight ; a second length is 
 attached by means of a joint or coupling, and the lengthened pipe is again 
 driven into the ground. The addition of successive lengths of pipe is con- 
 tinued until water is reached. Finally a small pump is attached to the 
 uppermost length of pipe, and the well is complete. 
 
 Leakage of sewage into tube-wells is much less likely to occur than 
 into ordinary shallow wells. Nevertheless, when the pump is vigorously 
 worked, sewage may be drawn into the tube from a considerable distance. 
 Of course, tube-wells are not adopted for any but limited supplies of water. 
 
 Besides imderground springs on the continent of Europe, and also in 
 America, it is not uncommon to obtain supplies of drinking water from 
 underground tanks, tunnels, and galleries sunk parallel to the bed of a 
 river, and in the proximity of this. The theory of these constructions 
 was that water would percolate or filter from the bed of the river into 
 
WATER 239 
 
 the reservoir constructed for its reception. This supposed percolation can, 
 however, occur but rarely ; and nearly invariably it is the underground 
 water, intercepted in its passage to the river, that furnishes the water for 
 use. Should the underground water be not intercepted it gradually finds its 
 way to the river, into and not out of which percolation almost invariably 
 takes place. It is well known, for instance, that the river Thames is in 
 this way largely fed by springs of such ground-water at various points in 
 its course. 
 
 That the above is the true explanation of the source of water-supply where 
 such underground tanks are constructed is proved by the experience of Toulouse, 
 where the supply of water was largely increased by removing such a tank to 
 a greater distance from the river Garonne, and intercepting the ground- 
 water at a higher level ; for, as is elsewhere stated, the level of the ground- 
 water invariably rises as we recede from a river. The experience of Dresden 
 is also significant, and to the same effect. The relative temperatures of the 
 river, the ground- water generally, and the water in the tanks in summer — 
 and, further, the hardness of the water in wells near the river^ — all support the 
 same view as to origin. Lastly, it is known that by pumping from a well 
 near the banks of a river, as e.g. the Elbe, the level of the ground-water 
 is depressed over a wide area. It is manifest, too, that were the water of 
 a river to percolate outwards through its bed, this would soon be so silted 
 up by the finely divided suspended particles in the water as to put a speedy 
 stop to the percolation. On the other hand, the groimd- water having no such 
 suspended particles, when filtering from a coarser into a more finely divided 
 stratum, will not clog the pores of the river bed, but rather will tend to keep 
 these open. It is remarkable that the underground tanks and galleries 
 referred to, though constructed on a false theory, have been so successful as 
 they have generally proved to be. 
 
 Occasionally the flow of underground water through fissures in the chalk 
 is utilised, and made to furnish an abundant water-supply, which may be of 
 considerable organic purity, as, for example, at Brighton, where the necessary 
 works were devised by Mr. Easton. This is done in the following manner. 
 At Brighton, and other places on the sea-coast, little streams of water may 
 be seen flowing seawards from the higher part of the foreshore. These are 
 commonly but erroneously supposed to be formed by sea- water which has 
 been dammed back into the porous strata at high-water. But when tested 
 these streamlets are found to be composed of fresh water. Further exami- 
 nation shows that where the coast is formed of pervious strata, as, for 
 example, cbalk, the level of the underground water forms a curve, beginning 
 at a point between high and low-water level, and rising as the sea is receded 
 from. The head or pressure of the underground water is always forcing, or 
 tending to force, the underground water out of the rock at the point where 
 the level of this comes out on the foreshore, whence at low water the issuing 
 water becomes visible. In winter the water-level in the soil forms a steeper 
 declivity than in summer, when the underground water stands at a lower 
 level in the subsoil. By sinking galleries into the chalk behind Brighton, 
 and parallel with the line of sea-coast, down to a level with the low or summer 
 level of the underground water, the riUs of this constantly passuig seawards 
 through the fissures in the chalk rock are tapped, and utilised for water-supply. 
 
 In adopting such a source of water as has been described, great care is 
 previously necessary to ascertain that the water is uncontaminated, since 
 fissures in the chalk are liable to serve as conduits for sewage from great 
 distances ; and it is these chalk fissures which often render a water-supply 
 drawn direct from the chalk a polluted or suspicious one. 
 
240 HYGIENE 
 
 The water derived from deep artesian wells in the British Isles is usually 
 of excellent quality, and remarkably free from oi'ganic matter. Exceptionally 
 such wells yield a brackish water. In England, artesian wells are often of 
 great depth, being sunk through the chalk and into the lower greensand 
 formation where this is covered by the gault. But artesian wells are not 
 always or necessarily sunk in the above-named geological strata. What is 
 required for their formation is that a well be sunk through an upper imper- 
 vious stratum into a subjacent pervious and water-bearing stratum, in which 
 the water is confined under such ahead or pressure that when tapped it rises 
 in the well-tube or bore-hole to a considerable height, or even to the surface. 
 Unfortunately the water from artesian wells is often saline, and is the water 
 holding in solution the salts of saline beds of remote geological formation, 
 probably from lakes and inland seas. But when not unduly saline, these 
 waters are of excellent quality, clear, colourless, of uniform temperature 
 throughout the year, and pleasant to the taste. These are, however, some- 
 times rather hard ; but those in and about London are decidedly alkaline 
 from the presence of several grains of bicarbonate of sodium in each gallon 
 of water, and are hence somewhat soft. Some deep weU-waters are warm, 
 as, e.g. those of Bath ; and then are unfitted for ordinary drinking purposes. 
 Others, again, have a slight odour of sulphuretted hydrogen, speedily lost on 
 free exposure to the air. These feebly sulphuretted waters may be trouble- 
 some when stored in cisterns, in consequence of the readiness with which 
 they become filled with filamentous vegetable growths. 
 
 Sometimes water is obtained from wells and borings made direct into the 
 solid chalk, which is not usually a water-bearing rock. In such cases a bore- 
 hole is driven into a fissure or fault in the rock, such fissures being common 
 in the chalk, and acting when filled with water as underground streams. 
 "Where the fissures have one general direction, an adit or channel may be 
 made at right angles to their course — as at Brighton, where, as has been already 
 stated, the water is systematically abstracted to form the town water-supply. 
 
 The proposals that have been made in the instances of London and other 
 large cities to substitute a supply from deep wells for a river-supply have 
 generally been viewed with doubt by the majority of engineering authorities. 
 Deep wells may yield a tolerably constant and copious supply of water, if not 
 unduly taxed ; but it by no means follows that were a much larger supply 
 attempted to be obtained from these strata, which yield a moderate supply, the 
 yield would be commensurate with anticipations. The quantity of water 
 present in strata at any one time is limited ; and the experience derived from 
 the artesian wells in a London district is that the level of the deep water, and 
 hence its head or pressure, is steadily falling year by year, and that the 
 underground supply from such wells is by no means an unlimited one. At 
 Guy's Hospital, the artesian well formerly yielded a supply adequate to the 
 needs of the institution ; whereas now it affords only one half of the requisite 
 quantity, and the well is pumped on alternate days, and not every day as 
 formerly. 
 
 Exceptionally, an artesian well may furnish a polluted water-supply : 
 and some have furnished mimistakable evidence of the sources of their 
 impurities in the shape of dead fish, marsh plants, roots, seeds, &c. It is 
 supposed that in some of these cases these materials have been conveyed 
 in subterranean conduits from great distances. 
 
 Generally, it may be said that spring waters, if not of a thermal, medicinal, 
 .aperient, or chalybeate character from the too great or unusual nature of their 
 constituents, furnish pure and excellent supplies of water. Indeed, the 
 German Public Health Association some years ago arrived at the conclusion 
 
WATER 241 
 
 that spring waters alone — either those coming naturally to the surface, or ob- 
 tained from wells— are the only admissible sources of water-supply. This 
 too sweeping resolution was, however, subsequently rescinded. Nevertheless, 
 it shows what a high value German hygienists very properly attach to springs 
 as sources of the very best water-supply. 
 
 The advantages of spring waters have been thus summarised by the 
 Rivers Pollution Commissioners :— 'That preference should always be given 
 to spring and deep-well water for purely domestic purposes, over even upland 
 surface water, not only on account of the much greater intrinsic chemical 
 purity and palatability of these waters, but also because their physical pro- 
 perties render them peculiarly valuable for domestic supply. They are 
 almost invariably clear, colourless, transparent, and brilliant, qualities which 
 add greatly to their acceptability as beverages : whilst their uniformity of 
 temperature throughout the year renders them cool and refreshing in summer, 
 and prevents them from freezing readily in winter. Such waters are of 
 inestimable value to communities, and their conservation and utilisation are 
 worthy of the greatest efforts of those who have the pubhc health under 
 their charge.' 
 
 The Eivers Pollution Commissioners, 1868, analysed a large number of 
 well waters from shallow wells with the following results : — 
 
 1. Waters from shallow wells in or tcpon Silurian Bocks and Gneiss. — 
 Solids 2-4 to 70-1 grains per gallon ; average 16-7 grains. Hardness 2°-4 to 
 29°'l ; average 7°-6. 
 
 2. Waters from shallow wells on Devojiian Bocks. — Solids 8"5 to 73'6 
 grains ; average 27*5 grains. Hardness 3°*5 to 39° ; average 14°-6. 
 
 3. Waters frofii shalloio ivells on the Yoredale and Millstone Grits. — 
 Solids 4*1 to 93-5 grains per gallon ; average 35-1 grains. Hardness 2° to 
 63° ; average 22°'l. 
 
 4. Waters from shalloio tvells on the Goal Measiires. — Solids 6*6 to 154*6 
 grains per gallon ; average 48 grains. Hardness 2°-4 to 98°-6 ; average 24°-4. 
 
 5. Waters from shalloiv tvells in or on Mountain Limestone and Mag- 
 nesian Limestone. — Solids 32*1 to 76*2 grains per gallon ; average 50*4 
 grains. Hardness 28°-5 to 62° ; average 40°*9. 
 
 6. Water from shallow wells in or on Neiv Bed Sandstone. — Sohds 14-4 
 to 168*1 grains per gallon ; average 71*1 grains. Hardness 12° to 89° ; 
 average 34°*5. 
 
 7. Water from shalloiv wells in or upon the Lias. — Solids 26 to 214*8' 
 grains per gallon ; average 77*8 grains. Hardness 1°*9 to 81°*8 ; average 
 35°*8. 
 
 8. Waters from shallow wells in or on the Oolite. — Solids 21*7 to 188*7 
 grains per gallon; average 64 grains. Hardness 16° *1 to 55°*2 ; average 
 82°-4. 
 
 9. Waters from shallow wells in or on the Upper and Lower Greensand 
 and Wealden Beds. — Solids 7*4 to 266*8 grains ; average 50 grains. 
 Hardness 2°*7 to 56°*4 ; average 19°*7. 
 
 10. Waters from shallow wells in or on the Chalk. — Solids 22*7 to 111*4 
 grains per gallon ; average 55*6 grains. Hardness 16°*7 to 50° ; average 30°*5. 
 
 11. Waters from shallow wells in Gravel on the London C/a?/.— Sohds 
 22*3 to 277*5 grains per gallon ; average 71*2 grains. Hardness 10° to 
 133°*7 ; average 35°*6. 
 
 12. Waters from shallow wells in Bagshot Beds. — Solids 16*2 to 200*8 
 grains per gallon ; average 82*2 grains. Hardness 9°*2 to 92°*2 ; average 
 38°*5. 
 
 13. Water from shallow ivells in Fluvio-Marine Series. — Sohds 5*7 to 
 
 VOL. I. K 
 
242 HYGIENE 
 
 ■JtG-3 grains per gallon ; average 19-1 grains. Hardness 3°-2 to 25°-5 ; 
 average 10°'8. 
 
 14. Waters from shallow wells in AlUivium and Gravel. — Solids 20 
 to 224-5 grains per gallon ; average 69-6 grains. Hardness o°'2 to 10G°-7 ; 
 average 83°*3. 
 
 ElVER-WATER 
 
 Eiver-water varies greatly in quality, and also as to its organic purity. 
 Some rivers yield water of unimpeachable quality : whilst others, as e.g. the 
 Irwell at Manchester, afford only a filthy, disgusting liquid. The saline 
 constituents of river- water vary according to the kinds of soil through which 
 the tributary streams flow, the springs or ground-water which find then- 
 outlet in the bed of the river, and the nature of the soil through which the 
 river itself flows. Generally, it may be stated that a river- water is less hard 
 and saline than the water of its tributary streams in the lower part of its 
 ■course ; but it may be much harder and more saline than the waters of the 
 upper tributaries, if these flow from a country abounding in igneous rocks. 
 The chalk held in solution by carbonic acid in the contributory springs 
 becomes in part thrown out of solution by the escape of carbonic acid on 
 exposure to the atmosphere during flow in the river, and this tends to 
 diminish the hardness of the water. 
 
 The liability to contamination of the water of rivers in agricultural, and 
 still more in manufactuiiug districts, is a great drawback to the use of such 
 waters as sources of domestic supply. Fortunately, the self-purifying action 
 going on in rivers is very great, and there is the compensating advantage 
 that in large rivers of considerable length the supply, as in the case of the 
 Thames, is fairly constant and abundant ; and it must be admitted that 
 river- waters, even after a few miles' flow and efficient filtration, so as to 
 remove all suspended matters, sometimes form a fairly safe source of supply ; 
 and in proof of this the supply of London with drinking water taken from the 
 Thames above the tidal lock at Teddington may be adduced as a signal 
 instance. Before the chief water-supply of the metropolis was by statute 
 compelled to be taken exclusively from the river above the unpolluted 
 reaches, cholera and perhaps other diseases were produced among the 
 inhabitants of London by the drinking of polluted river- water ; but since 
 about 18G6, when the change was effected, no appreciable amount of disease 
 has ever been proved to have been caused in the metropolis of England by 
 means of the filtered water as delivered to the consumers. This, coupled 
 with the fact that no source of supply so abundant, sure, and uniform exists 
 Avithin a reasonable distance of the metropolis, has hitherto effectually stood 
 in the way of the adoption of any other water-supply for London. 
 
 What has just been said must not be taken to indicate that the pollution 
 ■of a river-water by filth is of no consequence, provided there be a good flow 
 of a few miles before the intake of a drinking water-supply is reached. The 
 writer merely wishes to indicate that the danger attending the use of river- 
 water which has been antecedently polluted has been exaggerated. The 
 late Professor Rolleston expressed an opinion that the introduction of 
 -cholera germs into the Thames at Oxford might result in an outbreak of 
 that disease in London, but these anticipations have not been reahsed. Dr. 
 Frankland has also stated that ' there is no river in the United Kingdom 
 long enough to purify its waters spontaneously if they have once become 
 contaminated with sewage (' Applied Chemistry,' p. 552), a statement to 
 which few would venture to subscribe in the present day. The truth 
 appears to be that rivers are able to get rid of their sewage pollution 
 
WATEB 243 
 
 hy the combined agencies of oxidation, growth of vegetation, and the 
 activities of organisms such as bacteria and the lower forms of vegetable 
 growth ; and there is practical but not absolute safety if the polluting 
 material be not introduced in excessive proportion, and the river have a free 
 flow of several miles, especially over a rocky bed and weirs, so as to subject 
 the water to agitation and consequent abundant aeration. The late Dr. 
 Letheby and Dr. Tidy have been the strongest supporters of this hypothesis, 
 which has also received the support of Dr. Odling. Nevertheless, it must be 
 admitted that the experience of 1806 with respect to cholera — the last 
 visitation of that disease — is insufficient to enable a satisfactory conclusion 
 to be drawn, affirmatively or negatively ; and more recent experience appears 
 to show that a flow of several miles in a river is insufficient to destroy the 
 activity of the poison of typhoid fever. 
 
 Some rivers afford a highly polluted and dangerous water, though 
 directly they may receive no great quantity of sewage, or even none what- 
 ever. These rivers are derived from a peaty soil, or from ground-water and 
 springs in a highly porous polluted soil. A signal example is the river 
 Blackwater in Surrey, which comes from the Bagshot Sands, a sandy porous 
 soil, the springs in which are highly impure. It is stated that the Upper 
 Bagshot Sand yields a pure water, whilst the Middle Bagshot Sand yields a 
 highly polluted water-supply. 
 
 Eiver-waters in mining and manufacturing districts may become specifi- 
 cally polluted, so as to render them entirely unfit to serve as sources of 
 water-supply. The Fifth Eeport of the Elvers Pollution Commissioners deals 
 fully with these sources of pollution, in mining districts arising from 
 collieries and coal-washing — iron, copper, lead, tin, arsenic, manganese, and 
 baryta mines ; from china-clay works, and from metal manufactures. Their 
 First and Third Eeports treat of pollution by manufacturing refuse. The 
 Commissioners (Sixth Eeport, p. 418), while admitting that the drainage- 
 water from arable lands is preferable to that from polluted shallow wells, 
 apparently were of opinion that river-water is inadmissible as a somxe of 
 town supplies, a conclusion which the writer considers far too sweeping. 
 
 QUANTITY OF WATEE FOE DOMESTIC AND OTHER SUPPLIES 
 
 The amount of water needed for domestic and other uses is a matter of 
 important consideration to Medical Officers of Health. In making ar- 
 rangements for a town supply, he will of course have the aid of the engi- 
 neer to guide him as to the quantity of water available from a given source ; 
 but in rural districts he may have no such assistance. In all cases his 
 advice will be sought as to the requirements for domestic use, both as regards 
 quality and quantity. The adequacy of storage reservoirs is also a matter 
 to which he cannot be indifferent, though advice as to the sufficiency of these 
 to supply the needs of a community during long periods of drought should 
 be obtained from the meteorologist and engineer. 
 
 Different estimates have been put forth as to the minimum quantity of 
 water required for domestic purposes, and these vary greatly, and must 
 necessarily vary according to the habits of the community to be dealt with ; 
 the social class to which the majority of them belong ; the general or partial 
 use of water-closets ; and the proportion of the population using household 
 baths. A water-supply that would be ample for a population mostly com- 
 posed of agricultural labourers would be quite inadequate for the ordinary 
 
244 HYGIENE 
 
 needs of a wealtljy or even a middle-class town community. Happily, sani- 
 tary authorities are becoming alive to the necessity of increasing their water- 
 supplies, and such supplies as would a few years ago have been deemed 
 ample, are now admitted to be insuilicient for the maintenance of health and 
 comfort. Yet it must be admitted that greater economy in the use of water 
 is frequently called for, and that enormous quantities of water under our 
 present systems of distribution in towns are simply wasted. The supply 
 should, nevertheless, be liberal, and not niggardly, lest health be imperilled ; 
 and it is better to err on the side of excess than to run the risk of want of 
 water and its consequences — impaired health, and disease. On the average 
 of a community, about one-fourth of a gallon per head per day is the quantity 
 of water necessary for drinking purposes. But this is only a small fraction 
 of that required for domestic use. Dr. Parkes measured the water actually 
 used in several houses, and gave the following as the amount used by a man 
 of the middle class, who, he, says, might be taken as a fair type of a cleanly 
 man belonging to a fairly clean household : 
 
 Gallons daily 
 per one person 
 
 Cooking 0-75 
 
 Fluids as drink (water, tea, coffee) 0*33 
 
 Ablution, including a daily sponge bath, which took 2\ to 3 gallons . . 5"0 
 
 Share of utensil and house washing ........ 3'0 
 
 Share of clothes (laundry) washing, estimated ...... 3"0 
 
 Total 12-08 
 
 This quantity is, perhaps, not quite adequate for the needs of the 
 average person in most towns or villages, and it is generally thought that a 
 minimum supply of 12 gallons per head per day is not excessive where no 
 baths are used. A good bath requires 50 gallons of water ; and if general 
 baths are used once a week, 5 or 6 gallons per head should be added to the 
 daily consumption (Parkes). Where water-closets are used, an additional 
 allowance of 6 gallons per head per day should be further added ; and 2 or 
 3 gallons should be allowed for waste. Thus we arrive at the following 
 figures, stating the quantity of water required per head per day for purely 
 domestic purposes : 
 
 Gallons 
 
 Drinking and cooking 1 
 
 Ablutions and general weekly baths 7 
 
 Washing and laundry 6 
 
 Water-closets ......... 6 
 
 Flushing and waste 5 
 
 Total 25 
 
 A further quantity must be allowed for manufacturing towns and for trade 
 purposes, flusliing of sewers, street watering, and the washing of horses and 
 other domestic animals. An allowance of 35 gallons is not too much for 
 a town supply. London has a supply of about 40 gallons, and Glasgow of 
 50 gallons per head per diem, and these are thought by many sanitarians to 
 be too little. 
 
 Dr. Pole, a high autliority on all matters relating to water-supply, 
 states, nevertheless (' On Water-Supply,' pp. 13, 14), that the quantity actually 
 required for domestic consumption, including a fair allowance for household 
 purposes, for water-closets, and for ordinary ablutions, is probably not more 
 than about 10 gallons per head per day. But, in addition to domestic con- 
 sumption, supplies have to be provided for gardens and stables, manufactur- 
 ing and trade purposes of many kinds, baths and wash-houses, public fountains, 
 
WATER 245 
 
 ■watering streets, flushing sewers, and extinguisliing fires ; and he says that 
 the quantity for these purposes will vary from 5 to 10 or more gallons per 
 head per day. It is usual, he states, to estimate the normal consumption of 
 a town at 25 gallons per head per day, and he thinks that this quantity will 
 be, or, at all events, ought to be, a sufficient supply for all purposes. Sani- 
 tarians will, perhaps, not be inclined to agree with him, and may consider 
 25 gallons per head per day a sparse supply. With little waste there is no 
 doubt that 25 gallons is a better supply than .85 gallons with no adequate 
 care to prevent avoidable waste. Further, as the above eminent engineering 
 authority insists, water is not only a very expensive thing to provide, and its 
 excessive use not only wastes money, but does positive mischief by increasing 
 the difficulty of carrying it away. There is certainly balance to be struck 
 between the evils of a too abundant, i.e. wasteful, and a too sparing supply 
 of water ; but of the two evils the sanitarian will undoubtedly consider the 
 too abundant supply the least. The advantages to a community of an at all 
 times ample supply of water are incalculable ; whilst the inconveniences of 
 Sb too abundant supply — if such be possible — are remediable, and by com- 
 parison small. 
 
 In hospitals and infirmaries an abundant supply of water is a prime 
 necessity, and a copious extra supply should be stored in tanks in case of 
 fire. In a large London hospital (Guy's), the daily quantity used is 45 
 gallons per patient, or 35 gallons per head, including resident staff. This 
 includes laundry water, and that used in the Medical School and Laboratories. 
 But provision should be made for a larger supply than this in case of need. 
 In towns, where possible, the supply for large establishments is economised 
 when supplied by meter. It is a regrettable fact that no efficient water-meter 
 has as yet been generally introduced for the registration of small supplies ; if 
 it were otherwise, there is little doubt that great waste of water would be 
 avoided, and that smaller supplies would suffice, if every householder had 
 his water supplied by meter. 
 
 The following miscellaneous data relative to the quantity of water 
 xequisite for water-supplies are useful : 
 
 Waste-preventers of w.c.'s require f to 2 gallons for each flush of the 
 •closet ; even one flush of 2 gallons is usually insufficient to keep the pan 
 clean. 
 
 A horse drinks 6 to 10 gallons, a cow 6 to 8 gallons, a sheep or pig ^ to 
 1 gallon daily (Parkes). Where horses and carriages are kept, at least 16 
 gallons per horse per day should be allowed for all purposes. 
 
 In non-manufacturing towns 5 gallons per head per day should be allowed 
 for trade purposes ; and in manufacturing towns double that amount, viz. 
 10 gallons. 
 
 On the strictly constant system of supply, with due supervision so as to 
 prevent waste, 15 gallons per head per day may suffice for a non-manufactur- 
 ing town, or not much more than half that required under the wasteful 
 intermittent system. 
 
 INSUFFICIENT WATEE-SUPPLY 
 
 The immediate effect on the human body of an insufficiency of drinking 
 -water is very manifest in the form of excessive thirst, and an irresistible 
 craving for fluids ; and if no other means of gratifying this craving is at hand, 
 the most filthy and disgusting liquids will be eagerly drunk. There is, indeed, 
 
24G HYGIENE 
 
 no need of the body so imperative as that for drink. But tLis condition is 
 not one that often comes under the notice of the sanitarian : rather it is the 
 less immediate results of an insufficient water-supply that he has to deal with 
 and combat, such as want of personal cleanliness, dirty clothing, defective 
 cooking, filthy habitations, accumulations of excreta, iincleansed streets, 
 courts, and alleys, choked drains, and unflushed sewers. The result of 
 these defects is well recognised in the general lowering of the health of the 
 community, the prevalence of typhus and occasionally of typhoid fevers, skin 
 diseases, ophthalmia, and pcn'liaps many other diseases. Other, and generally 
 alcoholic, fluids will be drunk, and thus the degradation of a people having a 
 deficient water-supply ^N-ill be aggravated. The results are far-reaching. 
 Some half-century ago deficient water-supplies were more common than in 
 the present day, and the First and Second Reports of the Health of Towns 
 Commission for 1844-5 contain abundant evidence of this. 
 
 It is difficult to ascertain how far the health of a town suffers from a 
 temporary scarcity of water during a water-famine ; but inferentially we 
 should expect the efiects to be considerable. Generally, however, in the 
 ' water-famines ' of our British towns, the term water-famine is a very relative 
 one ; and the supply of water in such times of scarcity of the fluid would not 
 very many years ago have been considered sufficient for domestic use. 
 
 STOEAGE 
 
 The storage of water may be considered under two heads — 
 
 A. Storage of public water-supplies. 
 
 B. Storage in and about dwelling-houses, &c. 
 
 A. Storage of Public Water-Supplies 
 
 The amount of storage required for the water-supply of a town necessarily 
 varies, not only with the numbers of the community to be supplied, but also 
 according to their habits, and the industrial occupations carried on ; and in 
 manufacturing towns the amount of water required for industrial purposes 
 may exceed that required for domestic use. Whatever be the required daily 
 supply, the storage capacity of the reservoirs in rainy districts should equal 
 150 days' dry weather supply (Pole) ; and in dry districts 200 days' supply. 
 These estimates apply to the British Isles only ; and in drier countries a much 
 larger storage must be provided. Dr. Pole (' Water Supply,' p. 21) has 
 given some simple and useful formulae for calculating the collecting area 
 requisite, where the rainfall is known, and the loss from evaporation fairly 
 established. 
 
 If R = the mean rainfall in a given year, in inches, 
 E = the estimated loss by evaporation, &c., in inches, 
 A = the area of gathering ground in acres, 
 
 then 
 and 
 
 Gallons of water per day = 62 A (R — E) ' 
 
 Cubic feet of water per year = 3630 A (R — Ej 
 
 Mr. Hawksley's formula for calculating the number of days' storage 
 requisite is to divide 1000 by the square root of the annual rainfall in inches.. 
 
 ' See note, p. 233. 
 
WATER 247 
 
 1000 1000 
 
 Thus, with a rainfall of 36 inches, the clay's storage required is 
 
 n/3G 6 
 
 = 167 days ; and with a rainfall of 64 inches is _--=—-— = 125 days. 
 
 V 64 8 
 
 In rural districts, where the wells supply a too scanty or a polluted water, 
 it is often advantageous to combine a group of villages, introduce water from 
 one source, and thus economise cost. It is a misfortune that in England 
 there is no officer corresponding to the Public Engineer for water-supply who 
 in at least one Continental kingdom (Wlirtemberg) advises local authorities 
 gratuitously on questions of water-supply, and who, having an intimate 
 knowledge of the whole water-supply of the kingdom, is able to give invalu- 
 able information and advice, and whose duty it is to see that economy of cost 
 is exercised. In all schemes for the furnishing of water to villages— and 
 much more when districts or towns have to be supplied — it is important to 
 have regard to the natural water-sheds, the available percentages of rainfall. 
 and the quantity of the movements of the ground-water ; and these data can 
 only be furnished by a technically skilled officer, whose knowledge extends 
 much beyond the requirements of one particular district. 
 
 All storage reservoirs should be well protected from contamination by 
 cattle, and by excreta of human beings. They should be kept free from 
 weeds, some of which may communicate an unpleasant taste to the water ; 
 and all dead and decaying vegetable matter is more or less injurious. When 
 in the neighbourhood of towns and factories, the reservoirs should be covered, 
 so as far as possible, to exclude contamination by solid particles floating in the 
 atmosphere. The strength and stability of reservoirs are matters foreign to 
 the scope of this article. 
 
 But in all cases before a public supply is stored in covered reservoirs the 
 water should be subjected to a process of clarification, which may sometimes 
 be effected by simple subsidence. This process needs in the great majority 
 of cases, however, to be supplemented by filtration, and occasionally by a 
 softening process, of which the Porter- Clark process is the best. These 
 matters will be again touched upon hereafter. 
 
 B. Storage of Water in and about Habitations 
 
 The storage of Avater in and about a dwelling-house is a necessary evil. In 
 rural districts, where the supply is from wells, such storage in tanks and 
 cisterns is often indispensable. Such tanks and cisterns should be of slate 
 by preference, or, failing this, of iron or galvanised iron. The zinc of gal- 
 vanised iron is, however, apt to become detached, or even dissolved if the 
 water is soft. A non-corrodible cement may be used for coating the interiors 
 of iron cisterns. Zinc cisterns have all the disadvantages of galvanised iron, 
 and are deficient in strength, so that they are not easily cleaned out without 
 damage being done to the cistern. Leaden cisterns are permissible only 
 when it has been ascertained that the water to be stored exerts practically no 
 solvent action on lead. Cisterns should not be larger than is necessary ; their 
 contents should, if possible, be renewed daily, and at all events frequently. 
 They should be covered and protected from all sources of contamination ; they 
 should have no direct communication wdth any cesspool, drain, sink, pri\y, 
 or water-closet. All storage reservoirs for water should be thoroughly 
 cleansed at least once every three months. 
 
 For towns the question of the relative values of the constant and inter- 
 mittent systems of supply is most important ; but the preponderance of opinion 
 is undoubtedly in favour of the constant syst<em as best securing economy of 
 
248 HYGIENE 
 
 water, purity, palatability and coolness, and personal and domestic cleanliness. 
 In a no distant future an intermittent supply will, it may be hoped, be 
 regarded as an anomaly. 
 
 DISTRIBUTION 
 
 Water, in whatever manner it has been stored, has pjenerally to be dis- 
 tributed to houses by means of closed conduits or pipes ; and usually the 
 ' head ' or pressure requisite for its distribution is obtained by gravitation, 
 although a preliminary pumping into special storage reservoirs may be 
 requisite, where the usual storage reservoir is situated at too low an eleva- 
 tion to secure the pressure necessary to raise the water to the level of the 
 highest houses in the district to be supplied. Wherever possible, this 
 pumping should be avoided on account of its cost. Pipes used for conveying 
 the water fi-om the reservoirs to streets are called mains, and are nowadays 
 mostly constructed of cast iron, which is sometimes lined with cement or 
 some kind of varnish-hke material, such as Angus Smith's bituminous 
 varnish, in order to protect the pipes from corrosion. From the street 
 mains the water is conveyed into the houses by means of subsidiary and 
 smaller pipes, termed supply-pipes, which are usually of lead. Lead is the 
 most convenient and useful, though by no means the safest metal for the 
 construction of these pipes, and generally for distributing water through 
 houses ; and in the end it is perhaps cheapest. All the efforts made to bring 
 about the substitution of other materials for lead in distributing pipes have 
 met with only very partial success. The strength and flexibiUty of leaden 
 pipes, the ease with which they may be bent and adapted to recesses, 
 and soldered together, with their small liability to leakage, are invaluable, 
 and go far to counterbalance its liability to corrosion in the vast majority 
 of cases. They are, however, liable to corrosion and consequent contamina- 
 tion of the water by the poisonous metal lead. This action of water upon 
 lead will be again adverted to, and discussed in detail. 
 
 The only kind of pipe that has entered into serious competition with the 
 leaden pipe is the iron pipe ; although a variety of materials have been 
 used, such as tin, lead lined with tin, tinned copper, galvanised iron, earth- 
 enware, gutta-percha, bituminised paper, &c. All these have, however, 
 proved to be more or less failures. Leaden pipes lined with tin would at 
 first sight appear to be the most promising substitute for lead, since they 
 combine in a high degree the flexibility and adaptability of this metal, and, as 
 has been supposed, with freedom from corrosion of tin. Their safety as 
 regards protection of the lead from the influence of water is nevertheless 
 illusory, and they are costly. The tin is hable to crack when the pipe is bent, 
 and thus the lead becomes exposed, and being in contact with the less cor- 
 rodible metal tin, and both in contact with a saline Uquid, a galvanic couple is 
 established ; and the more oxidisable metal (lead) undergoes solution. Thus 
 the contact with tin actually hastens the corrosion of the lead. The joints 
 also, when made with lead solder, are also liable to corrosion, and the pro- 
 tective influence is thus illusory. Finally, though less corrodible than lead, 
 tin is acted upon by ordinary natural waters ; and pipes of block tin, when 
 used for the conveyance of water, have been found deeply pitted from corrosion. 
 But it is generally thought that tin- contaminated water is less harmful than 
 that which contains lead, though accurate observation as to this is wanting. 
 On the whole, when iron pipes can be used, they are the safest from a 
 sanitary point of view. The hning of them with zinc (galvanising) is not 
 often of much use, as the zinc coating is generally rather quickly removed 
 by soft waters. 
 
WATER 249 
 
 DOUBLE SUPrLT 
 
 It is sometimes difficult to obtain an adequate supply of water sufficiently 
 pure to meet the needs of a community for all puiposes ; and under such 
 adverse circumstances it has been proposed to have a double supply, one of 
 pure water for drinking and cooking, &c., and another, less pure, for closets, 
 ■drains, and sewers. So long as the impure supply is under control, and in 
 limited to public and trade purposes, no objections can be raised, except on 
 the score of the cost of distributing a double supply. But for household use 
 a double supply must be deprecated. In a house the supply which is most 
 copious and easily accessible will generally be used by preference, except the 
 impure supply be foul to the senses. Common household experience shows 
 that servants, even of the better class, will, when two taps are side by side, 
 draw water from that which delivers water most freely (generally that from 
 a cistern, where one tap delivers from the main and the other from a cistern). 
 In this respect the majority of people cannot be trusted to make a choice. 
 A double supply for household use ought not to be adopted, except for very 
 cogent reasons. 
 
 PKEVENTION OF WASTE 
 
 There has been much difference of opinion as to the respective amounts 
 of waste attending the adoption of the two opposing systems of public water- 
 supply, the intermittent and the constant systems. It has been urged as an 
 objection to the general adoption of the constant system of supply, that 
 where an unlimited supply of water is at all times obtainable there will be 
 .an undue use of water, a large portion of the water taken being allow^ed to 
 run to waste. Experience under the intermittent system of supply has, 
 singularly enough, furnished fallacious argum^ents for this contention. 
 Experience under the constant system has belied the above unfounded 
 conclusion. It is not found, with a constant supply, that it is altogether 
 impossible to limit the consumption — or rather consumption plus waste — 
 to a reasonable amount. On the contrary, with good regulations, vigilant 
 inspection of cisterns, waste-pipes, and taps, waste is brought within reason- 
 .able limits, and the undue use of water may be limited in other direc- 
 tions. To large water-consumers the supply may be by meter ; but it has 
 not hitherto been found possible to supply water by meter in all cases. 
 The small meters sometimes used do not act well, and, in fact, they are said 
 to allow the liquid to pass through them unregistered. The same cannot be 
 ;said of large meters. At all events. Water Companies, charging rates, appear 
 to have an invincible repugnance to supplying water on any but a very large 
 scale by meter. For towns the preponderance of opinion is undoubtedly in 
 favour of the constant system, as best securing economy of water, purity, 
 palatability, coolness, and personal and domestic cleanliness. A prejudice 
 was created against the constant system by the absurd regulations attempted 
 to be introduced so as to prevent waste, such as the dehvery of water through 
 minutely constricted pipes so that the water would issue only in a dribble. 
 Such regulations are impracticable, and dangerous in case of fire ; and 
 with proper supervision it is found that the substitution of a constant 
 for an intermittent system has actually resulted in the saving of water. 
 Indeed, in the present day, the relative values of the two systems can hardly 
 be a matter of dispute ; and no householder who has experienced the comfort 
 and benefits of a constant supply would willingly have a reversion to the 
 
2.:0 HYGIENE 
 
 intermittent system. Even for villages — and oftcner for groups of villages — 
 a constant supply is nowadays frequently laid on, to the great comfort and 
 advantages of rural populations. 
 
 The recent experience of London — now in part having a constant 
 supply — is altogether in favour of the constant system, and shows that with 
 moderate inspection no midue waste or cost is incurred. Moreover, meters 
 have been devised which enable the water companies to ascertain, in case of 
 need, in what particular districts waste or consumption is going on, and 
 thus to arrive at a loiowledge as to where more supervision is required. Nor 
 need this supervision and inspection be unduly inquisitorial. The experience 
 of the town of Blackburn is, in this respect, instructive. 
 
 In the New World the intermittent system has never been largely intro- 
 duced. But it nmst be admitted that the figures given by the Boston 
 (U.S.) Water Board (Buck's ' Hygiene,' vol. i. p. 212) of the several 
 supplies in 1879 of water to eighteen cities of the United States show that 
 the town supplies in the States are larger than in England. The supplies 
 there stated range from 22 to 100 imperial gallons per head per day, with an 
 average of 50 gallons, or about 50 per cent., more than is supplied to London. 
 lUit the strict comparison of places, widely differing in climate and the habits 
 of the peoples inhabiting them, cannot in fairness be insisted on. 
 
 CLARIFICATION OF DEIXKING WATER 
 
 Spring-waters and well-waters are usually sufficiently clear and free from 
 deposit to need no adventitious aid to render them acceptable to the eye,, 
 and palatable. Indeed, such waters, when clear, are best delivered direct to 
 the consumers, so as to avoid contamination by exposure and manipulation. 
 It is otherwise with waters collected from large gathering areas, and with 
 river-waters. These both commonly contain so much suspended matter, 
 and are so much discoloured, as to necessitate a preliminary treatment in order 
 to render them clear, pellucid, colourless, and free from objectionable deposits. 
 Hard waters, especially those from springs, and less often river-waters, may 
 also be improved in appearance and better fitted for domestic and manufac- 
 turing purposes, by being deprived of a portion of their mineral constituents 
 before distribution to the consumers. This is best done by the Porter-Clark 
 process. 
 
 Claeification by Subsidence 
 
 The grosser sohd particles suspended in upland surface waters, and in 
 those taken from rivers and lakes during times of flood, are often readily, 
 expeditiously, and cheaply got rid of by simply allowing the water to come 
 to rest in storage reservoirs for a variable period ; but finely divided clayey 
 matter is not thus easily removed, and may remain suspended in the water 
 for days, or even weeks. A signal instance of the self-clarification of a 
 turbid river is seen in the case of the water of the river Khone during its 
 passage through the Lake of Geneva, which acts as a huge subsidence reser- 
 voir in which the highly turbid water comes to comparative rest. Thus the 
 water is allowed to deposit the solid suspended matters with which it is con- 
 taminated on its entrance into the lake (see p. 263, _posi). 
 
 In the waterworks of all large towns, when the water is taken from 
 upland collecting grounds or from streams — natural, or, failing these,, 
 artificial reservoirs, are made use of, so as to at least partially clarify the 
 water before it is subjected to subsequent filtration. When discoloured 
 
WATER 251" 
 
 peaty upland waters are stored in this manner, much of the brown discolora- 
 tion is got rid of, and it is said that the deeper the reservoirs the more 
 effectually is the colour removed. Thus, in Loch Katrine, the lake which 
 supplies Glasgow with water, the brown peaty water discharged into the lake 
 from its contributory streams loses most of its colour, and is delivered in 
 Glasgow in a practically colourless state. It has been supposed that the 
 loss of colour thus undergone on storage is due to the oxidation which peaty 
 matter undergoes under the influence of light — oxidation being much more 
 active under the influence of light than in the dark. But it is more probaljle 
 that, although oxidation is undeniable, much of the peaty matter in water is^ 
 not truly dissolved, but is in a minute state of subdivision which enables it 
 to remain suspended, and that these fine suspended particles subside on 
 standing. The fact that deep reservoirs, which are less readily aerated with 
 oxygen than shallow ones, are more efi'ective than the latter in removing 
 peaty discoloration is against the oxidation theory. It is known that 
 during the bleaching of a peaty water by natural processes, a brown deposit 
 subsides ; but whether this is the actual discolouring agent in the water or- 
 an oxidation product thereof, is undetermined. 
 
 Deep lakes and artificial reservoirs have the great advantage over 
 shallow ones of preserving the water at a more uniform temperature, neither- 
 too warm in summer nor too low in winter as to permit of freezing. 
 
 Clarification and limited purification of water by subsidence appear to 
 have been known to and practised by the Eomans; indeed the piscinae 
 which have been described by archaeologists as filtering places, appear to- 
 have been subsidence tanks of special and ingenious construction ; and we 
 learn that they were not always successful, but that turbid water was 
 delivered in the Imperial City during times of flood. 
 
 At St. Petersburg the waters of the river Neva are clarified, and ren- 
 dered purer, by a special process, the water being caused to fall in successive 
 cascades each of a couple of feet, on to wire gauze. The gauze soon 
 becomes covered with a black scum, although the water before this treatment 
 is apparently clear. The water of the Neva is a marsh-land water ; and the 
 scum is supposed to be formed by the combined effects of ' flocculation ' and 
 oxidation of the organic constituents of the river-water (' Proc. Inst. Civ.. 
 Engineers,' xxvii. p. 46). 
 
 FILTRATION 
 
 The clarification of a town water-supply is usually supplemented by 
 filtration ; and its purification is also to a certain extent effected by the same 
 means. We shall consider filtration on a large scale as carried out with 
 large supplies, and domestic filtration, i.e. the local filtration of relatively 
 small quantities of water in habitations. 
 
 On a large scale, water, after treatment in subsidence reservoirs, is nearly 
 always, in this country at least, filtered through sand and gravel. No great 
 success has attended the attempts to substitute other materials for these, or 
 as a supplement to sand and gravel. It must not be supposed that sand acts- 
 solely as a mechanical strainer ; for it is also an agent in achie-ving the 
 oxidation of organic matter, either by the air contained within its pores, or- 
 more probably by the condensation of oxygen on its surface ; for all finely- 
 divided solid substances have this power of condensing oxygen. In this 
 condensed state, oxygen is well kno-wn to be peculiarly active in bringing^ 
 about oxidation. Of this power charcoal in a minute state of di-vision is & 
 striking instance. Vegetable charcoal has the power, when ignited and 
 
252 HYGIENE 
 
 plunged into oxygen, or even into air, of absorbing several hundred times its 
 volume of the gas, and then becomes an intense oxygenant. 
 
 As ordinarily constructed, a filter-bed may be regarded as a (J -shaped 
 tube, with a long and a short limb, the longer limb, some ten feet in length, 
 being represented by the bed of filtering material plus the superposed unfil- 
 tered water. The filtered water (effluent water) collects in what may be re- 
 garded as the shorter limb of the tube. The water is forced downwards 
 through the filtering material by a head or pressure of water represented by 
 the difference in level of the water in the two limbs of the apparatus. The 
 filtering medium may consist of a stratum of fine clean sand, two feet in depth, 
 followed by eighteen inches of screened gravel of various sizes, the finest being 
 at the top and the coarsest at the bottom ; and below this there may be 
 thirty inches of broken stones of two sizes, the smallest size at the top. 
 Thus the water in its passage downwards meets successively with filtering 
 material of progressively increasing size as to its particles and the magnitude 
 of the interspaces. The topmost layer of fine sand is the real filtering 
 medium. 
 
 The New Eiver Company's filter-beds are constructed, from below up- 
 Avards, of six inches of bricks, followed by a similar thickness of gravel, and 
 on the top of this a layer of sand thirty inches deep ; and the water is usually 
 allowed to stand to a depth of five feet on the top of the filter-beds. The 
 water percolates downwards at about the rate of six inches per hour ; or half 
 a cubic foot, equal to 'd}j gallons, passes through each square foot of surface per 
 hour, or 14: gallons per diem, equivalent to 180,000 gallons nearly per acre per 
 hour. This rate is thought by some authorities to be excessive, and they 
 would put the maximum permissible rate at 60,000 to 100,000 gallons per 
 acre per hour, or from three to four and a half inches of downward progres- 
 sion per hour. 
 
 As has been already stated, it is the uppermost layer of sand which is the 
 effective purifying material ; and this layer in contact with the main body of 
 water to be filtered soon becomes foul and clogged, so that the filter-bed has 
 to be run dry and its upper surface scraped pretty frequently, when a fresh sur- 
 face being exposed the filter is again set in action. Thus the filter-beds are 
 worked intermittently, some of the beds being always undergoing renovation. 
 After a certain quantity of the sand has in this way been removed by succes- 
 sive scrapings, fresh sand must be placed on the filter. 
 
 Such filters as have been described, are effectual in removing all suspended 
 matters from the water, if this be not forced through the filter-beds too 
 rapidly by excess of pressure. The rate will vary according to the character 
 of the water to be operated on. It is obvious that a slightly turbid Avater may 
 be filtered with safety at a much greater rate than a highly turbid water. 
 Filtering beds vary in size from half an acre, or even less, up to four acres. 
 The depth of water over the filtering material may be four or five feet ; but 
 the actual head or pressure of water — the difference of level between the 
 height of the water in the two limbs of the U-^ube — must be made to vary : 
 when the filter is clean a foot or less of head or pressure will suffice ; but as 
 the filter becomes clogged by use, a greater pressure must be used, else the 
 water will not pass through the filter with sufficient rapidity. It must 
 be borne in mind that the slower the filtration the more effective will it be 
 in purifying the water. The aim of the engineer is of course to filter just so 
 much water per hour as is consistent with the desired degree of purity. The 
 rule is that each vertical inch of water passing represents half a gallon nearly 
 per square foot of surface, or 22,700 gallons per acre per hour, approxi- 
 jmately — the requisite supply for about UOO people. 
 
WATEE 25a 
 
 In variable climates deep filter-beds are best, so as in winter to Lave a 
 large body of water so as to avoid freezing ; and tlie edge of the water must 
 be kept free from ice, in order to obviate the outward thrust of this if it 
 forms, else the masonry of the walls of the filter-beds would be endangered. 
 Deep filter-beds have the additional advantage of keeping the water cool in 
 summer ; but they have also the disadvantage of greater liability to stagna- 
 tion than those which are shallower. 
 
 The filtered water should be stored in covered reservoirs, so as to avoid 
 contammation with dust ; and reservoirs near towns are usually required by 
 statute to be effectively covered. It is desirable also to distribute the water 
 from the reservoirs through closed pipes rather than through open conduits. 
 
 Filtration through sand alone undoubtedly does more than simply remove 
 suspended matters and living organisms : organic matters are oxidised, and 
 the water is thus much improved not only in appearance but also as to its 
 purity. Attempts have been made to further purify waters by using filter- 
 beds charged with charcoal, spongy iron, partially oxidised scrap iron, &c. ; 
 but all these have in this country been abandoned in practice. They are too 
 costly, and require too frequent renewal to admit of their profitable adoption ; 
 and moreover if a fairly pure v/ater- supply be adopted (and none other should 
 be used) the use of any better filtering material than clean, well-washed sand 
 is not called for. The attempted purification for drinking purposes of organi- 
 cally polluted water ought to be deprecated. An essentially bad water cannot 
 be turned into a good water by any practically available process of simple 
 filtration. 
 
 The Porter-Clark process is an admirable one for removing excess of 
 temporary hardness, and the carbonate of calcium deposited in the process 
 carries down with it organic matters, so that the filtered water is fairly soft, 
 clear, and of a fine blue tint when viewed in thick layers. 
 
 Household Filtbation 
 
 Under the head of household filters may be placed the innumerable filters 
 which have been introduced for filtering water immediately before its use in 
 houses, factories, and like establishments. 
 
 Where water, efficiently filtered on a large scale, is distributed direct from 
 the storage reservoirs on the constant system, the writer is of opinion that it 
 is as a rule best to draw the water direct from the main supply-pipe, and to 
 use it without further filtration. But where the water is supplied on the 
 intermittent system, and is consequently stored in household cisterns, it is 
 often desirable to filter it before use. Also in times of epidemics it is desir- 
 able for safety to boil drinking water and filter it before use. More often than 
 not, perhaps, a drinking water is rendered less pure by ordinary filtration ; 
 and nearly always household filters are placed inmost undesirable situations, 
 such as near sinks, in pantries, near kitchens, &c. i.e. in impure atmospheres. 
 Under these conditions the water is apt to absorb gases and vapours which give 
 it an unpleasant flavour ; and this is more particularly the case when the 
 water is boiled. Boiling water when cooled in an impure atmosphere very 
 quickly absorbs gases and vapours ; and thus it is notorious that water which 
 has been boiled is not only very often vapid but positively nauseous in flavour. 
 
 Notwithstanding these disparaging remarks as to domestic filtration, it 
 must be admitted that there are circumstances under which a water must be 
 filtered in order to render it wholesome. Marshy water, taken by the soldier 
 on the march from doubtful or obviously impure sources, and soft peaty 
 waters which have passed through leaden pipes, must be filtered. 
 
254 HYGIENE 
 
 The varieties of filtering media whicli have been vised are innumerable ; 
 but it may be stated generally that these display the skill of the inventor 
 and patentee to excess, and that most of them are of comparatively httle use 
 with regard to real effective purification. 
 
 Fresh burnt animal charcoal is perhaps the best of all filtering media, 
 and filters chiefly constructed of this material should always be used for 
 lead-polluted water-supplies. The experience of Mr. A. H. Allen with the 
 Shefiield waters is to the effect that no other substance is nearly so efficacious 
 as animal charcoal for removing lead from water. In jMaignen's ' Filtre 
 Eapide,' animal charcoal and asbestos cloth are used. Vegetable charcoal is 
 far less efficacious than animal charcoal as a purifying agent. Seaiveed 
 charcoal is said to be superior to ordinary vegetable charcoal in this respect. 
 The great defect of all forms of charcoal filters is that they speedily become 
 inefficacious, and the charcoal must be frequently renewed or re-burnt, else 
 the fouled charcoal will, as Dr. Franklaud has shown, actually increase the 
 amount of organic impurity in the water. Block-carbon filters (moulded 
 • carbon blocks) do httle more than remove gross suspended particles, are 
 )nostly useless, and should not be used except when no better filter can be found, 
 as by the soldier on the march, to whom a small suction filter is invaluable. 
 Sponge is now not often used. It merely removes suspended particles, 
 and soon clogs and becomes foul. Sponge filters require constant attention, 
 and frequent cleaning and renewal. Asbestos is a much better material, and 
 •can easily be re-burnt. It acts only mechanically. 
 
 Porous stone, pumice, and ground slag (Chamois Filter) act merely as 
 mechanical filtering media ; and filters constructed of these materials are 
 not very serviceable. 
 
 Spongy iron (Bischoff's filter), magnetic carbide, silicated carbon, and car- 
 bonised ironstone are useful filtering materials, which act mechanically as 
 strainers, as oxidisers by surface condensation of oxygen, and also perhaps by 
 electrolytic action. 
 
 Carferal or carbolite (Creuse's Service Filter) is an efficacious filtering 
 medium. It appears to be made from clay with some iron and carbon. Its 
 preparation is somewhat of a secret. Creuse's filter is a good simple one, 
 and easily cleaned. 
 
 The Chamberland-Pasteur Filter is perhaps the best of all domestic 
 filters. Its construction is very simple, for it merely consists of a tube of 
 fine unglazed biscuit porcelain, which may be screwed on to the service 
 tap, when the pressure of the water will force the fluid through the pores 
 of the porcelain, and a fairly rapid rate of filtration results. It is most 
 efficacious m removing even the finest suspended particles, for even the 
 bacilh of anthrax are by it effectually removed from water. This filter acts 
 purely mechanically. It appears to be inefficacious for the removal of lead 
 from waters. The surface of the porcelain tube in a short time becomes 
 covered with a slimy coating, even when an apparently clean water is filtered. 
 This coating is, however, readily and quickly removed by removing the tube 
 .and brushing it, or by washing it with hydrocliloric acid. 
 
 QUALITY OF WATEE 
 
 In their Sixth Eeport the Elvers Pollution Commissioners, 1868, remarked 
 that in respect of wholesomeness and general fitness for drinking and cooking 
 their researches led them to the following classification of waters in the 
 -order of their excellence, and founded upon their respective sources : 
 
"Wholesome . 
 
 .-2. 
 3. 
 
 Suspicious . 
 
 (5. 
 
 Dangerous . 
 
 J6. 
 17. 
 
 WATER 255 
 
 Spring- water \ Very 
 
 Deep well-water I palatable. 
 
 Upland surface water . . . .\ Moderately 
 
 Stored rain-water j palatable. 
 
 Surface water from cultivated land . . , 
 Eiver-water to which sew;i'j;G gains access. [- Palatable. 
 Shallow well-water . . . . .j 
 
 And they urged that preference should always be given to spring and deep 
 "well-water for purely domestic purposes, over even upland surface water, not 
 only on account of the much greater intrinsic purity and palatability of 
 these waters, but also because their physical qualities render them peculiarly 
 valuable for domestic supply, since they are almost invariably clear, colourless, 
 transparent, and brilliant ; qualities which add greatly to their acceptability as 
 beverages, whilst their uniformity of temperature throughout the year renders 
 them cool and refreshing in summer, and prevents them from freezing readily 
 in winter. Their inestimable value to communities in these respects is, 
 however, in some degree neutralised, as regards temperature, when they have 
 to be stored, and too often the qaantities available are inadequate to supply the 
 needs of large communities, and too costly. Hence we find that for large towns 
 ■upland surface water-supplies are now being largely adopted ; as witness 
 Glasgow from Loch Katrine, Manchester from Lake Thirlmere, and Liver- 
 pool from Lake Vyrnwy. Often, too, it is desirable, and more especially 
 in the case of a manufacturing population, to have not only an organically 
 pure, and a palatable, but also a soft water-supply ; and here the advantage 
 of an upland surface water becomes manifest, as appears from the following 
 classification, according to the Eivers Pollution Commissioners, of natural 
 waters, in the order, of their softness : 
 
 1. Eain- water. 
 
 2. Upland surface water. 
 
 8. Surface water from cultivated land. 
 
 4. Polluted river-water. 
 
 6. Spring-water. 
 
 6. Deep well-water. 
 
 7. Shallow well-water. 
 
 The geological strata through which a spring or deep well-water has per- 
 colated will greatly influence its palatability. "Whilst surface waters are 
 often vapid and tasteless from a deficiency of carbon dioxide, or have a 
 peaty bitter flavour, in percolating through deep rocky strata organic 
 matters are oxidised, and such waters are often highly charged with carbon 
 dioxide gas, which renders them brisk and palatable. The waters drawn from 
 deep artesian wells in the Thames basin are often deficient in oxygen and 
 faintly opalescent. Some also contain traces of sulphuretted hydrogen, and 
 need exposure to the air to render them palatable ; whilst others, again, when 
 stored, become impregnated with confervoid growths. The spring waters of 
 the magnesian limestone formation are not only excessively hard, but con- 
 tain such a proportion of magnesian salts as, in the opinion of most sanitary 
 authorities, renders them unfit for drinking purposes. A pure magnesian 
 water may, nevertheless, it is thought by many sanitarians, form a good 
 water for domestic use. The experiences of Sunderland and of Bristol are 
 not unfavourable to the use for drinking purposes of magnesian waters. 
 
 The deep well-waters of some of the beds of the New Eed Sandstone are 
 rich in sulphate of calcium, as well as in chalk, and, though palatable, are 
 excessively hard. 
 
256 HYGIENE 
 
 Of far more importance tlian its salinity and hardness is the freedom of 
 a drinking-water from contaminating injurious metals, such as lead, copper, 
 and chromium. Salts of barium, which in excess are i)oisonous, and in small 
 quantities medicinal, are found in some mineral waters — e.g. those of Har- 
 rogate. The influence of barium compounds in minute quantities is but 
 little known, and of but little interest to the sanitarian. 
 
 Copper compounds are injurious when habitually ingested, and hence 
 waters containing this metal ought to be rejected. 
 
 Chromium salts, especially chromates, act as virulent poisons even when 
 taken in small quantities. These compounds are but rarely met with in 
 waters, and exclusively in mining districts. 
 
 Chalybeate waters — those containing iron salts — are nauseous, stain 
 linen, and are unfitted for drinking and washing purposes. All natural waters, 
 perhaps, contain some small trace of iron compounds, but not sufficient to 
 communicate a perceptible flavour to the water. Chalybeate waters should, 
 if better water is procurable, be rejected as unfitted for domestic supplies. 
 
 Of vastly more importance is the contamination of waters by lead. Though 
 the corrosive action of certain w^aters upon lead has long been known, and 
 its influence recognised, and although many experimental researches have 
 been instituted with the view of elucidating this action, our knowledge of the 
 matter is still confessedly incomplete. Pure water, deprived of gases, has 
 little or no action on lead ; when, however, tlic water contains oxygen the 
 lead is rapidly corroded and dissolved ; the solvent action being hastened, if 
 not even started, by the presence of traces of carbonic or other acid. The 
 lead dissolved appears to be in the form of a hydrate (hydrated oxide of lead). 
 On exposure to air, the dissolved lead is soon thrown down in the foi'm of 
 the almost insoluble hydrocarbonate (basic carbonate of lead, or white lead). 
 The deposit is very finely divided and has very little coherence, and hence 
 when the deposit forms on the surface of the metal — as, for instance, when 
 there is simultaneous oxidation and precipitation of the lead on the surface 
 of a leaden pipe — the hydrocarbonate does not protect the metal beneath 
 from the further corroding action of the aerated water. Hence pure rain- 
 water and distilled Avater corrode lead with great rapidity. If a few grains 
 per gallon of sulphate of calcium be introduced into such a water, an 
 adherent and coherent thin grey film of a lead compound quickly forms on 
 the surface of the metal, and the water subsequently takes up a quite incon- 
 siderable amount of lead ; and thus the metal is preserved from further cor- 
 rosion. Other earthy salts have a similar effect. Some saline bodies, such as 
 nitrate of ammonium — a constituent of ordinary rain-water — increase the 
 solvent action of water upon lead. Carbonic acid diminishes the corrosive 
 action of waters on lead, probably by forming the insoluble hydrocarbonate ; 
 but an excess of carbonic acid, under increased pressure, increases the solvent 
 action of the water ( Muir). Hence aerated water ( ' soda water ' ) is exceedingly 
 liable to become contaminated with lead. 
 
 It has been asserted that carbonate of lead, like the carbonates of calcium 
 and magnesium, is more soluble in excess of carbonic acid than in water, and 
 that a bicarbonate of lead is formed when lead is present in solution in a 
 water containing excess of carbonic acid, and experimental proof of this 
 action has been furnished. 
 
 Among the many substances that have been credited with increasing the 
 solvent action of Avater upon lead are — carbonic acid ; free mineral acids ; 
 carbon acids, the product of the decay of vegetable matters, and especially 
 peat ; organic matters ; nitrates and nitrites ; and chlorides — a sufficiently 
 extended hst. Among the substances which have been stated, on the other 
 
WATER 257 
 
 hand, to retard corrosion and solution are carbonic acid, carbonate of calcium, 
 sulphate of calcium, phosphates, and silica, or rather dissolved silicic acid 
 (Odling, Crookes, and Tidy). Dr. Tidy asserts that waters which contain less 
 than half a grain per gallon of dissolved silica act freely upon lead, whilst 
 those which contain more than half a grain of silica per gallon do not — except, 
 perhaps, under exceptional circumstances — dissolve lead to any appreciable 
 or injurious degree ; and he, together with Drs. Odling and Crookes, have 
 proposed to artificially impregnate waters with silica when they contain such 
 a deficient quantity as to render them operative. They advise that such 
 deficiently silicated waters should be run over broken flints, or a mixture of 
 flints and chalk, or limestone, and it has been asserted that the flints are 
 obviously dissolved during the process. In opposition to this, the writer, 
 Dr. Dupr6, and Mr. A. H. Allen, have found that the soft waters (e.g. those 
 of Sheffield), which act freely and injuriously on lead are, in many instances 
 at least acid in reaction ; and that the acidity may be due to the presence 
 of fixed organic and inorganic acids, or both. The organic acids are due to 
 the oxidation of peat. The inorganic acid may be sulphuric, arising from 
 the influx of a ferruginous water containing a ferrous salt. On exposure the 
 ferrous salt oxidises and splits up into an insoluble basic ferric salt, and free 
 sulphuric acid or an acid sulphate. Such waters, when run over a weir or 
 along a conduit, composed of broken soft limestone or chalk, have their 
 acidity neutralised ; they take up a small quantity of carbonate of calcium, 
 and acquire additional hardness, corresponding to the excess of chalk dis- 
 solved beyond that consumed in neutralising the free acid. This extra hard- 
 ness may amount to a degree or two per gallon. The soap-destroying power 
 of the salts of calcium, formed by the action of the fixed acids, is not greater 
 than that of the free acids neutralised. 
 
 It must be admitted that the whole subject of the action of waters upon 
 lead, and its prevention, stands in need of further elucidation and research ; 
 and although we may in some particular instances be able to account for 
 the action of water upon this metal, the same explanation entirely fails in 
 other cases. Thus the writer of this article has found that whilst the 
 addition of an alkaline sihcate of sodium to distilled water will prevent the 
 corrosion of lead by the water, the same addition in other cases, under other 
 conditions, may fail as a preventive. Again, it is not only soft waters 
 exclusively that act on lead, for many hard waters will have the same effect. 
 Neither the silica theory, nor the acid theory, of the action of waters upon 
 lead, accounts for the whole facts known ; and of two apparently similar 
 waters as to constituents, one will act vigorously upon lead, whilst the other 
 may have little or no effect in dissolving the metal. 
 
 Mr. W. H. Power, having regard to the observed influence of acidity on 
 the solvent actions of soft moorland waters on lead, offers the suggestion that 
 the ' inscrutable behaviour ' of these waters in regard to plumbo-solvent 
 ability may be related to the agency, direct or indirect, of low forms of 
 organic life. This suggestion, no doubt, has as its basis the circumstance 
 that certain bacteria have been found experimentally to produce acid changes 
 in the culture media in which they have been grown ; but the results hitherto 
 obtained with the Sheffield plumbo-solvent waters are mostly negative 
 (Eeports of the Medical Officer of the Local Government Board for 1887 and 
 1888, pp. 280 and 453 respectively). 
 
 The experience of Sheffield, Keighley, and other English towns has been 
 
 repeated at Dessau in Germany. The water-supply of this town was free 
 
 from lead before distribution, yet 92 cases of lead-poisoning occurred within 
 
 a short time, and it was then found that the water took up lead from the 
 
 VOL. I. s 
 
258 HYGIENE 
 
 house-pipes ; and the water first drawn after standing in these was found 
 to contain 0-3 grain of lead per gallon. It was also found that when tin 
 was introduced into the pipes, the solvent action of the water on the lead 
 was increased. It was finally concluded that the mischief was due to the want 
 of hardness in the water itself, which was only equal to 3° to 3"-4 of Clark's 
 scale. By increasing the hardness to 0° or 7°-2, by the use of powdered 
 limestone, the mischief was remedied. It is stated that this result was due, 
 not to the increase of hardness, but to the removal of carbonic acid, the 
 absence of which rendered the water incapable of acting on lead. 
 
 The processes for preventing access of lead to the stomach through the 
 xuedium of drinking water may be divided into three groups, namely : (1) 
 processes for preventing the water from dissolving lead ; as an example of 
 such treatment, we may mention the addition of lime to the water, whereby 
 free acids are neutrahsed, and their solveut action upon lead avoided; (2) 
 processes for avoiding contact of the water with lead ; for example, by using 
 slate or galvanised iron cisterns, and glass-lined or tin-lined pipes; and 
 (3) processes for removing lead from the water after it has been dissolved 
 thereby ; as examples of which filtration through compressed carbon, sand, 
 .&c. may be instanced. Mr. Eaton estimated the cost of treating the 
 Sheffield water so as to avoid any solvent action upon lead at 20,000Z., with 
 an annual expenditure of 350Z. to maintain efficiency. The Sheffield water 
 contains free acid, and limestone has been found a preventive. Clearly it is 
 more satisfactory to strike the evil at its root by treating the water in such 
 a way before it gains access to the poisonous metal as to prevent it from 
 being contaminated thereby, than to trust to measures for preventing contact 
 ivith the metal, or for removing it after it has been dissolved in the water. 
 
 EFFECTS OF HAEDNESS OF WATEE USED FOE DEINKIXG AND 
 OTHEE DOMESTIC PUEPOSES. 
 
 Very different opinions are held as to the injurious or non-injurious 
 effects of the use of hard waters for domestic supphes. Up to some fifty 
 years ago scarcely a suspicion appears to have been entertained that such 
 waters might injure health, however unpleasant their use might be for 
 detergent purposes. The researches of the late Dr. Clark, of Aberdeen, on 
 the hardness of water, its estimation, and above all, the introduction of his 
 now widely-known process for softening waters, drew attention to the 
 subject ; so that in 1850 the General Board of Health arrived at the sweep- 
 ing conclusion that whilst ' Thames water (of about 14° of hardness) taken 
 up beyond the influence of the metropolitan drainage, and filtered, may be 
 used without injury to the public health and may be employed temporarily 
 until other sources can be laid under contribution ; we advise that Thames 
 water and other water of like quality as to hardness, be as early as practicable 
 abandoned ' (quoted in ' Eeport : Eoyal Commission on AVater-supply,' p. xxiv. 
 1869) ; and, ' that the presence of lime and other mineral matter deteriorates 
 the wholesomeness and value of the water for the purpose of drinking' 
 {ibid. p. Ixiii.). This Eeport was, however, not endorsed by the subsequent 
 Scientific Commission of 1851, consisting of the three eminent chemists, 
 Graham, Miller, and Hofmann, appointed to consider it; and they went so far 
 as to enunciate an opposite view. They said (p. Ixiii.) : ' It may be safely 
 asserted that no sufficient grounds exist for believing that the mineral 
 contents of the waters supplied to London are injurious to health. No 
 reasonable doubt, indeed, can be entertained of their salubrity. The shallow 
 
WATER 259 
 
 well waters of London vary from 32° to 80° of hardness, yet these waters 
 have never been pronounced unwholesome (i.e. on account of their mineral 
 constituents. — Ed.). . . . The only observations, from which an interference 
 of Hme in water, in deranging the processes of digestion and assimilation in 
 susceptible constitutions, has been conjecturally inferred, have been made 
 upon waters containing much sulphate of Hme and magnesia.' 
 
 Dr. Letheby considered a moderately hard water best for drinking 
 purposes, and for the general supply of cities. Mr. Thomas Ilawksley, the 
 engineer, states from his vast personal experience, that there are quite as 
 many fine-raced people Hving in hard-water districts as there are living in 
 soft-water districts ; and that quite 80 per cent, of the whole surface of the 
 ^lobe yields hard water. Sir John Simon, Dr. Miller, Dr. Frankland, Dr. 
 Odling, and Sir Benjamin Brodie, have all expressed their opinions that 
 hard waters — up to 20° of hardness at least — are not injurious to health. 
 Dr. Edward Parkes was of opinion that a hardness of over 10° or 12° might 
 be injurious. 
 
 There is no doubt that medical opinion has undergone some change as 
 to the alleged unwholesomeness of hard waters ; and it is now generally 
 accepted that excessively hard waters are injurious to the digestive processes, 
 though proof of this is difficult ; and the conclusion has been doubted. 
 Ooitre and glandular swellings, as well as the prevalence of urinary calculi 
 in certain districts, are associated with the use of hard waters. All are 
 agreed that where the hardness of a water is due to the presence of carbonate 
 of calcium, and to a lesser degree of carbonate of magnesium, i.e. when the 
 hardness is temporary or removable, little harm ensues ; but that when the 
 hardness is permanent, and due to the presence of the sulphates, nitrates, and 
 chlorides of calcium and magnesium, tlie dietetic value of a water is greatly 
 impaired. How far this opinion is based upon a solid basis of facts is at 
 least uncertain. The waters of the valley of the Eiver Trent, and very 
 many of those derived from wells and springs in the New Eed Sandstone 
 formation, are intensely seleniferous, i.e. abound in sulphate of calcium, and 
 yet are not generally considered harmful. Some of our town supplies, as 
 e.g. those of Bristol and Sunderland, are very hard, the water supplied to 
 Sunderland containing magnesia and sulphates, the equivalent of 14 grains 
 anhydrous and 28 grains crystallised sulphate of magnesium per gallon; 
 yet the Medical Officer of Health has not been able to trace any inconve- 
 nience to health, much less disease, to its use, and it is believed to be a 
 good wholesome water, though having a hardness of 25°. 
 
 As has already been stated, goitre and cretinism have been attributed to 
 the habitual drinking of excessively hard water. Eminent medical autho- 
 rities have, however, dissented from this conclusion ; very hard waters are, 
 it is true, found as a rule in districts where goitre prevails ; but the water- 
 supply is only one among many conditions shared by such localities in 
 common ; and it is alleged that of the inhabitants of two sides of a valley 
 with practically identical water-supplies as to hardness, those on one side of 
 the valley will suffer from goitre, whilst those on the other side will be 
 exempt from the disease. 
 
 For most culinary purposes a hard water is objectionable, and the presence 
 of calcium salts is said to harden the fibre of meat during boiling. Sulphate 
 of calcium, too, when boiled with leguminous seeds, is asserted to form hard 
 indigestible compounds with the legumin which they contain. But the evidence 
 as to this is not very conclusive. Generally a chalky water is quickly and 
 greatly softened by boiling, or by heating it simply to the boiling point ; the 
 carbonate of calcium held in solution by excess of carbonic acid being pre- 
 
 s2 
 
260 HYGIENE 
 
 cipitated in consequence of the escape of carbon dioxide gas at the boiling, 
 temperature. The Chemical Commission of 1851 (' Quart. Jour. Chem. Soc' 
 vol. iv. p. 388, 1852) found that the water supplied by the New Eiver Company 
 to London, having a total hardness of 14° to 15° and a permanent hardness 
 of about 2°, when drawn on six different occasions from the fixed boiler of 
 a kitchen range, had a hardness of 5°-4, 4°'9, 4°-l, 4°-l, 4°-9, and 5°-8 ; the 
 average being 4°*8, or one-third of the original amount. In tea-making, hard 
 water is thought by connoisseurs to yield a more delicate infusion than soft 
 water, and is hence preferred. A soft water, on the other hand, yields with tea 
 a darker and bitter infusion, and is hence more esteemed for the purpose by 
 the lower orders, who desiderate ' strength ' of tea. The chief difference in 
 this respect between a hard and a soft water is that when a hard water is 
 used a longer time is required for the infusion of the tea. 
 
 For washing and for manufacturing purposes a soft is undoubtedly pre- 
 ferable to a hard water, except in brewing. The relative values of waters 
 for washing purposes is a much more important consideration for a health 
 officer than their utihties for the purposes of the manufacturer. Never- 
 theless, in towns, the latter cannot, for economic reasons, be altogether 
 disregarded. The Chemical Commission of 1851 {ojJ. cit.) stated (and the 
 statement holds good in the present day) that the softer the water the better 
 is it adapted for washing with soap ; the earthy salts present causing a 
 definite and calculable loss of soap, which may be taken as amounting, with 
 every gallon of water used in washing, to 10 grains of soap for each degree 
 of hardness of water. But such data are not alone sufficient for calculating 
 the saving of soap effected by the use of a soft in preference to a hard water ; 
 for soap is used in washing not merely in quantity sufficient to soften the 
 water, but in excess to act as a detergent. The data to determine the pro- 
 blem how great is the proportion of soap lost in softening, compared with 
 the proportion profitably used for washing, are not easily obtained. It has, 
 however, been ascertained that in the washing of woollens 2 oz. of soap 
 per gallon is required ; and in the soaping of dyed goods— a process analogous 
 to common washmg — 0*45 oz. only per gallon. "With boiled Thames water 
 of 5° of hardness, these quantities would be increased to 2'11 and 0'5G oz. ; 
 or the quantities of soap required with a soft water are increased by 6 
 and 25 per cent, respectively. When cold water of 16° of hardness is used, 
 the quantities of soap consumed in washing will be 0'32 oz. per gallon in 
 excess of that used with soft water. 
 
 When soda is used in addition to soap, as in ordinary laundry work, the 
 loss of soap is much less, since the soda (carbonate of sodium) precipitates 
 the calcium salts in a form which prevents the destruction of soap. 
 
 The money loss involved in the use of hard water has been much exag- 
 gerated. The difference between the use of water of 2° and one of 14° of 
 hardness is about 128 grains of yellow soap per gallon, or 1^ oz. per 6 
 gallons, 6 gallons being the ordinary consumption of water per head per day 
 for washing purposes ; it being assumed that the water is used cold. The 
 money value of this amount of soap is O-OAd. ; whilst the cost of softening 
 35 gallons of water — the daily supply per head in towns — by the Porter- 
 Clark process is 0-012d. only. The difference is equal to rather more than 
 lO^d. per head per annum. 
 
 The case against the use of hard water was ably put by the Chemical 
 Commission of 1881 {op. cit.), who stated that it is in the more careful 
 washing for the upper and middle classes that the advantages of soft water 
 become fuUy sensible ; for when a hard water is heated the carbonate of 
 calcium is precipitated on the linen, carrying down with it the colouring 
 
WATER 261 
 
 matter of the dirty water, and producing stains which there is the greatest 
 difficulty in afterwards removing from the Hnen, The colouring matter 
 from the water is thus indeed fixed upon the cloth by the precipitated calcium 
 salt with the tenacity of a mordant. The evil of the hardness of the water 
 is also aggravated by the flood tinge of chalky river waters. The Commis- 
 sioners further stated that the saving of soap by the use of soft water is 
 most obvious in the washing of the person ; and for baths soft water is 
 undoubtedly most agreeable and beneficial. Its superior efficiency to hard 
 water in washing floors and walls is calculated also to promote greater 
 cleanliness in the dwellings of all classes, both within doors and externally ; 
 whilst in the occasional domestic washing of linen, the smaller preparation 
 necessary for washing in soft as compared with hard water, the saving of 
 soap, and the more easy and agreeable nature of the operation, make a supply 
 of soft water in a high degree desirable. The saving of labour is also con- 
 siderable, and tends to promote cleanliness. 
 
 At a later date the Eoyal Commission on Water Supply, 1869 (' Eeport,' 
 p. Ixxi.) thus fairly summarised the arguments for and against hard and 
 soft waters as public supplies for London :— 
 
 ' There is no doubt that the evidence is conclusive and cogent as to the 
 great advantage of soft water over hard for washing, and, with some few 
 ■exceptions, for general manufacturing purposes ; and if we were treating of 
 the supply of a town like those in the manufacturing districts of England, 
 where large quantities are required for these purposes, the objection to the 
 present supply (to London) would assume a more serious aspect. But the 
 amount of manufacturing industry in the metropolis, of a kind to demand a 
 large supply of soft water, is exceedingly small in proportion to the popula- 
 tion, and it must be recollected that the softening influence of boiling largely 
 diminishes the evil. To these exceptional cases, also, the softening process 
 of Dr. Clark would be easily applicable. 
 
 ' There is no doubt, also, that in personal ablutions and washing generally 
 the use of soft water is more pleasant and economical, but we think the 
 latter advantage has been much over-estimated. The soap is usually applied 
 out of the water, and therefore it is with the small quantity of water adherent 
 to the object washed that we have to deal, and not with the total quantity 
 used for rinsing to remove the soap. It is certain, however, that when a 
 soft water or rain-water can be obtained for these purposes it will always be 
 preferred. 
 
 ' On the whole we cannot see that the advantages of soft water .... 
 are of sufficient importance to justify going to a great distance to obtain it, 
 in place of the ample supply near at hand.' 
 
 To this the writer would add that the greater danger of lead contami- 
 nation, often introduced by the adoption of a soft and slightly acid water- 
 supply, may far outweigh, from a hygienic point of view, the disadvantages 
 resulting from the use of a water of moderate hardness. 
 
 There is another aspect of the question of soft verstis hard water which, 
 all-important to the manufacturer, is not without an important bearing upon 
 domestic supplies for a highly civilised and luxurious people. When a chalky 
 water is boiled, we have said that carbon dioxide is expelled and carbonates 
 of calcium and of magnesium are thrown down. Sulphate of calcium, how- 
 ■ever, remains in solution if the water be boiled under ordinary atmospheric 
 pressure ; hence the deposit, or ' fur,' which in household boilers is mostly 
 •composed of carbonate of calcium, and is soft, pulverulent, and for the most 
 part easily detached. But sulphate of calcium has its maximum solu- 
 bility at 95° F., at which temperature a gallon of water is capable of retaining 
 
262 HYGIENE 
 
 in solution 178 grains of sulphate of calcium. But as the water becomes 
 more saline by evaporation, the sulphate of calcium becomes less soluble. The 
 same result ensues if the water be heated under pressure much above 212° F. 
 (100° C.) Sulphate of calcium is quite insoluble in a boiling solution of salt 
 (brine) of sp. gr, 1-033, and in boilmg water at a temperature of 284°- 
 302° F. (140°-150° C.) Hence the difiiculties involved in the distillation of 
 sea-water, in the use of sea-water in marine boilers, and in the use of water 
 containing sulphate of calcium in boilers under pressure. Under these 
 cu'cunistances the hard furs which form on heating the water consist chiefly 
 of sulphate of calcium. 
 
 The Rivers' Pollution Commissioners, in their sixth report, thus classify 
 water according to their softness : 1. Rain-water ; 2. Upland Surface water; 
 3. Surface water from cultivated land ; 4. River-water ; 5. Spring-water ; 
 6. Deep well-water ; 7. Shallow well-water. 
 
 The following, according to the Commissioners, are the chief British for- 
 mations which yield, as a rule, soft waters : Ligneous; 2. Metamorphic ; 
 3. Cambrian ; 4. Silurian (non-calcareous) ; 5. Devonian (non-calcareous) ; 0. 
 Millstone Grit ; 7. Non-calcareous of the Coal-measures ; 8. Lower Greensand ; 
 9. London and Oxford Clay ; 10. Bagshot Beds ; 11. Non-calcareous gravel. 
 
 On the other hand, the following geological formations almost invariably 
 yield hard Avaters : 1. Calcareous Silurian ; 2. Calcareous Devonian ; 3. 
 Mountain limestone ; 4. Calcareous rocks of the Coal-measures ; 5. New- 
 Red Sandstone ; 6. Conglomerate Sandstone ; 7. Lias ; 8. Oolites ; 9. 
 Upper Greensand ; 10. Chalk. 
 
 POLLUTION OF WATER BY ORGANIC MATTERS 
 
 The pollution of water-supplies by solid and liquid refuse, such as sewage,, 
 slop- water, &c., is all-important from the health point of view. The facts, 
 so far as they are known, relative to the pollution of water-supphes by 
 soakage of filth are as follows : Sewage, when deposited on the surface of 
 an ordinary cultivated soil, percolates slowly or quickly into the subsoil, 
 according to the less or greater porosity of the soil. Whilst percolating it 
 becomes nitrified, through the agency of organisms which have recently been 
 identified (' Trans. Roy. Soc' 1890, p. 107). According to Mr. Warrington this 
 nitrif}'ing action is chiefly exercised m the more superficial layers of the soil,, 
 the action practically ceasing at 18 inches below the surface. If the 
 organic matter is in excess, or if the soil be persistently swamped with 
 sewage, nitrification ceases. The nitrifying process renders the nitrogenous- 
 matters harmless and fitted for the needs of growing plants, which absorb 
 and utilise the nitrates. When sewage is discharged in excessive quantities 
 on the surface of a porous soil, it quickly percolates through this until it 
 meets with an impervious stratum which arrests its downward course. A 
 shallow or surface well sunk into the porous soil will draw no water 
 until it reaches the stratum of underground water. Into this the liquid 
 soaking from leaky sewers, drains, and cesspits will find its way more 
 readily than the surface water. When water is pumped from such a well 
 the level of the water in this is depressed, and so also is the level of the 
 underground water in its neighbourhood, and assumes the form of a hollow 
 inverted cone, so that any soakage through the soil of liquid filth, or from a 
 drain or cesspool, -will inevitably be drawn by the afflux of fluid, according to 
 the laws of hydrostatics, towards the bottom of the cone — i.e. towards the- 
 well. The distance through which the hollow inverted cone will extend or 
 
WATER 2G3 
 
 make itself felt will vary according to the greater or less porosity of the soil, 
 and may extend to from 15 to 160 times the depth of the cone. In other 
 words, if the level of the water in a shallow well be reduced by pumping, 
 say 2 feet, water will be aspirated into the well from a distance of 
 15 X 2 =: 30 feet as a minimum, to IGO x 2 = 320 feet as a maximum. 
 The set or current of the underground water in the neighbourhood of a 
 pumped well must, indeed, always be towards the well ; and it is by the 
 suction exerted on cesspools situated in proximity to wells that they are 
 emptied when these are pumped. Hence, in one sense, the more a well is 
 pumped the greater its liability to contamination from neighbouring sources 
 of pollution. The action of wells in use may sometimes greatly divert the 
 course of underground water, which but for the action of wells would 
 always be towards a lower level and towards a stream. The course of under- 
 ground water is, indeed, precisely like that of surface water — towards the 
 lowest available level ; only the slope or declivity of underground is less 
 steep than that of surface water, in consequence of the greater retarding 
 influence of friction in its passage through the subsoil. 
 
 For the reasons just now assigned, a surface well can never be safe, hoAV- 
 ever well its sides are cased and made impervious, if there is any pollution 
 of the soil within the distance to which the inverted cone already described 
 extends. Contaminated water will be drawn into the bottom of the well. 
 The only real protection is to sink the well through the first impervious 
 layer of soil, and to cement the sides throughout to a point below the 
 impervious stratum, so as to draw water from the deeper strata, and to 
 protect this water from the more superficial polluted surface water. This 
 plan is too commonly not adopted because an abundance of water is reached 
 before the first impervious stratum of soil is reached, and at a small depth. 
 It is not infrequently found, also, that when the impervious stratum is- 
 penetrated the water, previously abundant, is lost ; and then the only plan 
 is to carry the well downwards till at a greater depth water is again found. 
 If such a supply is reached it may be expected, if not too salme, to be 
 abundant, little liable to seasonable variations as to quantity, quality, and 
 temperature, and organically pure. Very deep well-waters are, nevertheless, 
 often deficient in aeration, or rather oxygenation, as is well seen in the deep 
 artesian well-waters in and around London, these being sometimes almost 
 destitute of dissolved oxygen. 
 
 SELF-PUEIFICATION OF WATEE 
 
 The so-called self-purification of water is, strictly speaking, a misnomer, 
 for in all instances where self-purification occurs the purification is efl'ected 
 by some other agency, except perhaps in one case — that of the purification 
 of a water by subsidence, or the separation of solid suspended particles by 
 simply allowing the water to come to rest. But in even this case the 
 separation of solid particles achieves a further result, for dissolved organic 
 matters are in some way carried down ^^nth the deposited mud. A striking 
 instance is the purification of the waters of the river Ehone during their 
 passage through the Lake of Geneva. The turbid and organically polluted 
 water enters the head of the lake, having much the appearance of road- 
 washings, and the clarified and purified water is seen to issue from the lake 
 at Geneva as a beautifully pellucid and magnificently blue stream (see p. 250, 
 ante). 
 
 Waters are also said to be purified by dilution. It is doubtful whether 
 
264 HYGIENE 
 
 this purification ever takes place, except in so far as an impure water, by 
 admixture with a purer water also well aerated, is furnished with the oxygen 
 necessary for the destruction of impurities ; nor must it be forgotten that when 
 a relatively small quantity of a polluted liquid is mixed with a large quantity 
 of water of moderate purity, the added impurity may not increase the im- 
 purity of the latter to such an extent as to render its assured detection 
 possible to the chemist. 
 
 Dr. Franliland and the Eivers' Pollution Commissioners, in their 
 celebrated ' Sixth Eeport,' have thrown doubts on the self-purifying power of 
 streams through the agency of free atmospheric and dissolved oxygen ; but 
 this position has been successfully contested by Odhng, Letheby, Tidy, and 
 others ; and Dr. Frankland himself has apparently seen his way to modify 
 his previous views as to the oxidising power of dissolved oxygen. 
 
 It is probable that the salts of iron always present in natural waters in 
 very minute quantity act in some measure as carriers of oxygen. Putrescent 
 seAvage reduces these salts to the lower stage of oxidation of ferrous salts — 
 e.g. ferrous sulphide ; and these, under the influence of dissolved oxygen, 
 become converted into ferric or more highly oxygenated salts, which again 
 give up their oxygen to organic matter, and are agam reduced to the state 
 of ferrous salts. However this may be, the writer is convinced that free 
 oxygen is capable of effecting the rapid purification of streams, notwith- 
 standing the adverse laboratory experiments of Dr. Frankland. Some 
 think that iodine compounds, also rarely entirely absent from terrestrial 
 waters, act as carriers of oxygen, by their alternate oxidation into iodates 
 and reduction to the state of iodides. 
 
 Ordinary free oxygen, and, still less, atmospheric air, oxidise putrescible 
 organic matters when in dilute solution only slowly in laboratory experi- 
 ments. Under natural conditions, where water is exposed to an enormous 
 and practically unlimited volume of atmospheric air, the result is apparently 
 different ; and it is probable that atmospheric ozone and peroxide of hydrogen 
 may have much to do with the effective oxidation of the nitrogenous organic 
 substance present in the polluted waters of rivers. These oxidising agents 
 can have, however, little or nothing to do with the oxidation of organic 
 matters in the soil, and in the water percolating into the subsoil. Here a 
 different agency comes into play. 
 
 The changes which nitrogenous organic matters undergo during their 
 downward passage through the soil are, notwithstanding the extended 
 investigations bestowed upon them by Lawes, Gilbert, Warrington, and 
 others, only imperfectly understood. Under the ordinary conditions of 
 cultivation, nitrogenous manures — animal excreta in fact — I'apidly disappear 
 as such, their nitrogen being converted, first into ammonia, and then into 
 nitrates. Nitrification depends upon the presence of an organism, and takes 
 place chiefly in the superficial layers of the soil, and does not extend, as a 
 rule, much below 18 inches below the surface. In a cultivated soil most 
 of the nitrates are absorbed and utilised by growing crops, so that but little 
 nitrate flows away in solution in the subsoil water. It is not known that 
 the water drawn from the subsoil beneath such manured soils is injuriously 
 contaminated, though it is likely that Avhere the soil is excessively manured 
 the water may be unwholesome. It might, therefore, be anticipated, d i^riori, 
 that water taken from greater depths, such as that from shallow wells, would 
 be still less likely to contain injurious impurities. But abundant experience 
 teaches us that the water of shallow wells is peculiarly liable to contain 
 disease-producing impurities, except in those cases where the water supply 
 is protected by an impervious layer of soil, such as clay. Again, wells sunk 
 
WATEB 2G5 
 
 to no great depth in a gravelly soil frequently yield an organically polluted 
 water. These differences may be reconciled on the supposition that a well 
 draws polluting liquids rapidly through the superficial and nitrifying layer 
 of surface soil, so that the organic matters pass through large pores and 
 fissures in the soil, and thus escape the agency of those organisms which 
 would otherwise convert the nitrogenous matter into harmless nitrates. This 
 supposition receives confirmation from the well-established fact that the water 
 of shallow wells abounding in nitrates, though usually not decidedly harmful 
 to drink, occasionally gives rise to outbreaks of disease, and that these out- 
 breaks are usually accompanied by a diminution of the nitrates habitually 
 present in the water, and a corresponding rise in the organic nitrogen and 
 albuminoid ammonia. 
 
 The enormous extent of purification of streams effected by aquatic 
 animal and vegetable life has been too little appreciated. Where fresh 
 sewage flows from a sewer into a stream the mouth of the sewer becomes 
 the feeding-place of numerous small coarse-feeding fishes, which greedily 
 devour and convert into food for larger fishes the scraps of muscular fibre 
 and other d&hris which would otherwise decompose and pollute the stream. 
 Minute particles of solid organic matter may, and probably do, serve as the 
 food of minuter forms of aquatic animal life, and thus indirectly serve as food 
 for fish. The mud banks of the Thames estuary are the habitat of the finest 
 flat-fish, eels, and molluscs which serve the London market. But putrid 
 sewage-polluted streams are shunned by aquatic animals, and it is known 
 that stinking streams do not readily undergo self-purification — as witness 
 the Thames ; though here the saltness of the water below London Bridge 
 may cause the water to have a preservative effect on the molecules of un- 
 decomposed and decomposing sewage. To what extent subsidence, oxida- 
 tion, and the presence of animal life are respectively potent in bringing 
 about the purification of our rivers is at present quite unknown. 
 
 Nor must the beneficent effects of growing green plants be ignored. 
 Such plants, even those of a low type, are capable under the influence of 
 sunlight of effecting vast changes in the character of a water. The cleaning 
 out of tanks and ponds, so as to free them from weeds, has been known to 
 render the water of such reservoirs more impure, by depriving them of a 
 most active agent of purification. The oxygen given off by growing green 
 chlorophylliferous plants is probably like other forms of nascent or atomic 
 •oxygen, peculiarly active as an oxidiser ; and this furnishing of nascent oxygen 
 maybe one of the most valuable agents for effecting the oxidation of dissolved 
 and minutely divided solid forms of organic matter. 
 
 Lastly, vegetable matter deposited in the bed of a stream undergoes a 
 fermentative change, and one of the products of this change is marsh-gas, so 
 abundantly liberated on stirring the bed of any muddy ditch. This, then, is 
 another mode by which organic matter may be converted into harmless in- 
 organic forms of matter. 
 
 Nitrification — effected by an organism — is not a very active process in 
 running water, and it is a mode of changing organic into inorganic matter, 
 more effectively going on in soils than in rivers and other water-courses. 
 
 The probably enormous changes brought about by schizomycetes (bacilli, 
 bacteria, &c.) must also not be forgotten. 
 
 Altogether, then, the natural purifying agencies ordinarily going on in 
 streams are in the aggregate enormous, and generally effective. 
 
 Dr. Tidy, who is one of the strongest defendants of the potability of river 
 water, even after the influx of sewage, after a review of all the facts, thus 
 summarises his conclusions : 
 
2Gr. HYGIENE 
 
 1. That -svLen sewage is discharged into running water, provided the 
 piimary dikition of the sewage with pure water be sufficient, after the run 
 of a few miles, the precise distance of travel being dependent on several 
 conditions, the removal of the whole of the organic impurity will be effected. 
 
 2. That, whatever be the actual cause of certain diseases, i.e. whether 
 germs or chemical poisons, the materies morhi which finds its way into the 
 river at the sewage outfall is destroyed, together with the organic impurity, 
 after a certain flow. 
 
 These conclusions were formulated before the bacteriology of specific 
 diseases was developed ; but observation appears to show that a How of 20 
 miles in a river is not sufficient to destroy the germs of typhoid fever. 
 Dr. Barry, m a recent report to the Local Government lioard, expresses his 
 opinion that a flow of 40 miles at least is necessary after an irruption of 
 sewage in order to render the river-water a desirable supply for drinking 
 purposes. He bases his opinion on an outbreak of typhoid fever following 
 an irruption of lilth into the river Tees. 
 
 EFFECTS OF IMPURE ^yATER 
 
 No one in the present day doubts that epidemics may spread by means 
 of diinking-water, and the surmises of physiologists that this is brought 
 about by specific living germs or spores have within the last few years been 
 confirmed by the actual discovery of the bacilli or bacteria which are 
 the active factors in propagating certain forms of disease. But whether 
 the germs of disease present in drinking-water are the actual direct agents 
 in communicating disease, or whether the chemical products of the active 
 changes involved in the life-history of these germs are the intermediate fac- 
 tors, is not yet altogether determined. There is evidence, however, tending 
 to shoAV that it is in some cases the actual germs or living organisms in water 
 which propagate disease ; for waters specifically infected with dejecta, con- 
 taining minute traces only of organic matter, are capable of spreading a 
 disease. It is highly probalble that when a water receives typhoid or cholera 
 germs, these do not multiply in the water, but gradually perish, having no 
 appropriate nidus in which they may develop ; but that if the water still 
 containing any such living germs be drunk, a sufficiency of these may be 
 taken into the hmnan body to set up active disease, provided the body be in 
 a fit state for the germs to midergo development. The well-known fact that 
 when typhoid and cholera dejecta are very largely diluted with water they 
 become incapable of spreading these diseases points apparently to the oppo- 
 site conclusion ; but it may be that the usual non-spreading of cholera and 
 typhoid epidemics where the dejecta have been enormously diluted is to be 
 explained by the few germs received by any one individual on drinking the 
 excrement-polluted water. The experiments of Chauveau (' Comp. Eendus,' 
 18G8, pp. 289, 317, and 359 ; ' 12th Eep. of Med. Off. of Privy Council, 1869 ') 
 have shown clearly that it is the solid particulate matter of vaccine and 
 small-pox virus, &c., and not the soluble components thereof, which is con- 
 cerned in the propagation of these diseases by inoculation. Brieger's more 
 recent researches, and those of Dr. Sidney Martin (' 19tli Eep. Med. Officer 
 Loc. Gov. Bd.' p. 235) show, on the other hand, that bacteria may produce 
 specifically toxic chemical compounds. 
 
WATER ^m 
 
 Cholera 
 
 That cholera is a disease which, in this country at all events, is or has 
 been largely propagated by means of excrement-polluted water-supplies, is 
 abundantly evident. The experience of London as to cholera is most instruc- 
 tive, and as strikingly put in the ' 0th Eeport of the Rivers Pollution Commis- 
 sioners.' Epidemics of cholera have prevailed in London in the years 1832, 
 1849, 1854, and 1866. In 1832 a considerable part of London was supplied 
 with water from the rivers Thames and Lea, and the remainder from shallow 
 wells. But at that time the river water could not have been nearly so 
 polluted as subsequently, in consequence of the absence of sewers and the 
 comparative smallness of the population. The death-rate from cholera in 1882 
 was 3"14 per 1000 of the population. In 1849 the water was drawn from 
 similar sources, except that more water relatively was drawn from the river 
 than from wells. But meantime sewers had been constructed and water- 
 closets were in general use. Hence the river supply of water must neces- 
 sarily have been much more impure than on the occasion of the cholera 
 visitation of 1832, and the mortality from this disease rose to 6"18 per 1000. 
 In the epidemic of 1854 the mortality was 4*29 per 1000. In 1866 the main 
 drainage scheme of the metropolis had been carried out, and the sewage was 
 discharged into the Thames miles below London Bridge. In this epidemic 
 the mortality fell to 1"8 per 1000. In the cholera epidemic of 1849 in 
 London, it was observed that the population supplied with water from the 
 Thames suffered more and more from cholera according as the water was 
 abstracted from the river at successively lower points. Thus of those sup- 
 plied with water taken from the river at Kew, 0*8 per 1000 died of cholera ; 
 those supplied with water drawn at Hammersmith, lower down the river, 
 perished to the extent of 1*7 per 1000 ; in the west of London, the water 
 being taken at Chelsea, 4*7 per 1000 died ; whilst of those supplied with 
 water abstracted between Battersea and Waterloo Bridge, i.e. in the metro- 
 polis, no less than 16"3 per 1000 died of cholera alone. When cholera next 
 visited London, in 1854, the Southwark Water Company still continued to 
 draw its supply from the river at Battersea, close to one of the sewers ; and 
 the river was presumptively filthier than in 1849. In Bermondsey, which 
 was supplied with water by the above company, the deaths from cholera in 
 1854 were greater by 13 per cent, than in 1849 — a difference more than 
 corresponding to the increased population. But in the interval of five years 
 the Lambeth Water Company had removed their intake to a point above the 
 tidal lock at Teddington ; and it was found on comparing the houses in the 
 same district supplied by the two companies — the pipes of the two companies 
 often interlacing in the same street — that in the houses supplied from the 
 river within the metropolitan area the deaths from cholera were 57'1 per 
 1000 houses, whilst in those supplied from the Thames above London and 
 the tidal influence the deaths w^ere only 11-3 per 1000 houses. Well might 
 Sir John Simon term this a ' gigantic crucial experiment performed on half 
 a million of people ' (Eoyal Commission on Water Supply, 1869 ; ' Min. of 
 Evid.' p. 143). 
 
 Perhaps a still more striking experiment was made in the east of London, 
 in the cholera outbreak of 1866, by the East London Water Company, which, 
 in the language of the Rivers Pollution Commissioners (' Sixth Rep.' p. 145) 
 distributed ' unfiltered water excessively polluted with sewage,' and which, in 
 the opinion of Mr. Netten Radcliffe, was specifically contaminated with the 
 excrement of the first two patients who died in that year of cholera in the 
 
2G8 HYGIENE 
 
 east districts of London. Now the district of the East London Company, 
 supphed with water from this Old Ford reservoir, was the portion of their 
 district which was the sole area of intense cholera in London in 1866. Again 
 to quote Sir John Simon's words, ' The area of intense cholera in 1866 was 
 almost exactly the area of this particular water-supply, nearly, if not abso- 
 lutely, filling it and scarcely, if at all, reaching beyond it ' {ibid. p. 144). 
 
 It is not contended that water is the sole agent concerned in the distribu- 
 tion of cholera contagion, but it is certainly one of the chief media for extend- 
 ing the disease. 
 
 Perhaps the most instructive and striking instance of the spread of cholera 
 through the medium of polluted water is recorded as having occurred in 1854 
 around Golden Square, Soho, by means of the Broad Street pump. This 
 district, in which a formidable outbreak of cholera occurred, had a population 
 in 1851 of 42,272, and was not a low-class district. During August 1854 
 cholera was prevalent in the locality, but not to a serious extent ; but on 
 September 1 the disease broke out with fearful \dolence, and continued till 
 the morning of the 5th, when it began to abate. One of the chief features of 
 this memorable outbreak was its suddenness, and the large number of indi- 
 viduals simultaneously attacked in different parts of the district. The total 
 number of deaths fi'om cholera in September recorded in this limited area 
 was 609, or 14*2 per 1000 of the population. This district contained a public 
 pump — the Broad Street pump ; and this pump was the centre of the infected 
 district, for, starting thence, a person walking at a moderate pace in any 
 direction would have gone beyond the limits of the infected area within three 
 minutes. A special examination showed that the water of the well was con- 
 taminated by filtration from a cesspool during the time of the cholera out- 
 break. Though the water of the well was grossly impure, it was in great 
 repute through the neighbourhood for drinking purposes, and was much liked, 
 being cool, sparkling with carbon dioxide gas, and keeping well, in consequence 
 of the large quantity of saline matter it contained. But on exposure to the 
 air for a few hours it lost its freshness, and became offensive in a few days. 
 Dr. Snow was able to show that not only was the outbreak, properly so called, 
 principally confined to near about the pump, but that 61 out of 73 persons 
 who died during the first two days had been accustomed to drink the pump- 
 water ; that in the workhouse, where the well-water was not used, the deaths 
 from cholera were only one-tenth of the ratio prevalent in the neighbourhood ; 
 that no less than 9 per cent, of the people in a factory Avhere the water was 
 ■drunk daily died ; and that 70 men employed in a brewery in Broad Street, 
 and who never drank the water, all escaped cholera. Livestigation of numerous 
 individual cases entirely confirmed the conclusion that the Broad Street pump 
 water was mainly instrumental in propagating the outbreak of disease. 
 
 In further confirmation of the view that water is a fertile agent in spread- 
 ing the disease, the instance may be adduced of the outbreak of cholera on 
 board a steam-vessel in 1866 recorded by Parkes (' 9th Eep. of the Med. Officers 
 of thePri^'y Covmcil for 1866,' p. 244) ; the case of Utrecht (' Med. Times and 
 Gaz.' 1869, I. p. 626) ; and the striking coincidences in Scotland between the 
 abatement of cholera and the introduction of a fresh and pure water-supply. 
 (' Trans, of the Pioyal Scottish Soc. of Art,' vol. vii. 1867, p. 341, quoted by 
 Parkes). 
 
 It must be admitted that this statistical evidence is inconclusive, and that 
 it has been severely criticised by eminent authorities. It is, however, in 
 accord with other data, and cannot be ignored. When supplemented by the 
 data derived from the investigation of individual circumstances of outbreaks 
 of cholera, its significance becomes manifest. 
 
WATER 269 
 
 In Germany the connection between cholera and contaminated water- 
 supply has not obtained general acceptance ; and the great authority of 
 Pettenkofer could find no evidence from the experience of Munich in favour 
 of the theory (' Zeitschr. f. Biol.' Bd. I, p. 353). Giinther, too, asserted that in 
 1865 no connection could be traced in Saxony between impure drinking-water 
 and cholera (' Cholera in Sachsen im Jahre 18G5,' p. 125, quoted by Parkes). 
 But the subsequent experiences of Eichter (' Arch. d. Heilk.' 1867, p. 472), and 
 Dinger {ibid. 1867, p. 84), and others, have tended to establish such a connec- 
 tion. In India many observers have denied the causal connection of water 
 and cholera ; and the late Dr. J. M. Cunningham, once a firm believer in the 
 connection, subsequently renounced the theory of the water-carriage of cholera. 
 It cannot, therefore, be asserted that the theory is fully established to the 
 satisfaction of all competent observers. It may be that the conditions of the 
 dissemination of cholera may be different in India from those which obtain 
 in the cooler climate of England ; but this is hardly supposable to be the case 
 when England and Germany are compared. 
 
 Typhoid Fever 
 
 This endemic fever kills some five or six thousand people annually in 
 England and Wales out of a population of twenty-six millions, or 0-2 per 1000. 
 The poison of typhoid indubitably exists in the bowel evacuations of those 
 suffering from the disease, and hence is very frequently introduced into 
 drinking-water, which, as is now well known, thus becomes a chief, but by 
 no means the sole, agent in the distribution of typhoid. Moreover, it is now 
 pretty generally accepted that the germ of typhoid is a bacillus {Bacillus 
 typhosus, E. Corth), or rod-shaped schizomycete. It is stated that inoculation 
 experiments made with this bacillus have been successful (Eenkel u. Simonds ' 
 ' Die ^tiol. bed. des Typhus bacillus '). But long before this discovery was 
 announced the connection between typhoid and water-supply had been one 
 of the best established conclusions of scientific medicine ; and the discovery 
 of the active bacillus of typhoid seemed from a public -health point of view 
 merely to support the definite conclusions arrived at by statistical and indi- 
 vidual inquiries into the causation of the disease. 
 
 The proofs of this assertion lie elsewhere. In 1854 typhoid fever, then the 
 scourge of Millbank Prison, which drew its water from the polluted Thames, 
 was practically extinguished by the cessation of the old supply and the 
 adoption of a water-supply from the deep artesian well in Trafalgar Square 
 ('Lancet,' 1872, 1, p. 787). 
 
 In 1867 a severe outbreak of typhoid fever at TerHng, in Essex, was investi- 
 gated by Dr. Thorne by order of the Privy Council. One-third of the inhabi- 
 tants of Terling were attacked by the disease, and the death-rate was 45 per 
 1000 of the population. Three weeks after the appearance of the first (and 
 perhaps imported) case, the disease broke out with alarming virulence, and no 
 class of persons was exempt. The epidemic was preceded by a drought, and was 
 coincident with a rise of water in the village wells consequent on heavy 
 rainfall ; and these wells were much exposed to pollution by excremental 
 filth. Indeed, in summer, to use the expression of a resident, they were 
 ' nothing better than stinking pools.' There was, moreover, ample proof of 
 the connection between the rise of water in the wells and the attack of th& 
 disease. 
 
 This Terling outbreak was a signal instance of the immunity from typhoid 
 often seen in a population habitually drinking a filthy water, so long as this 
 contains no specific contaminating material. The introduction of the 
 
270 HYGIENE 
 
 specifically polluted filth from typhoid stools at once determined, however, 
 a virulent epidemic of typhoid fever (' 10th Report of the Med. Off. of Privy 
 Council,' 1867, p. 41). 
 
 Other instances may be adduced in confirmation of the teachings of the 
 Terling outbreak. 
 
 The most striking instance illustrative of the occasional persistency of 
 the typhoid, and other similar poisons, when they are diffused in water, and 
 then exposed to oxidising influences, occurred at the village of Lausen, near 
 Bale, in Switzerland, and was investigated by Dr. A. Hiigler, of Bale (' Deut. 
 Vierteljahrsschrift f. offentl. Gesundhcitspficge,' Bd. VI. S. 154 ; and ' 6th 
 Report of the Rivers Pollution Commissioners,' p. 463). In this previously 
 healthy village, which had never been known to be visited by an epidemic of 
 typhoid fever, and in which not even a single sporadic case of the disease had 
 been observed for many years, an epidemic broke out in August 1872, which 
 attacked almost simultaneously a large proportion of the inhabitants. Some 
 miles soutli of Lausen, and separated from it by the mountain ridge of the 
 Stockhalden, hes the small parallel valley of the Flirlerthal. In this valley 
 lived a farmer, in a solitary farmhouse, Avho was attacked on June 10 by 
 typhoid fever, just after his return from a long journey. A girl was attacked 
 in the same house on July 10 ; and in August the farmer's wife and son sickened 
 of the same disease. There was no communication, so far as could be ascer- 
 tained, between the farmhouse and the village of Lausen. On August 7, ten 
 of the villagers in Lausen were attacked by typhoid, and within the next nine 
 days the number of cases had risen to 57, out of a population of 780 living 
 in 90 houses. Within the first four weeks of the epidemic the number of 
 cases rose to 100, and at the close of the epidemic, at the end of the following 
 October, 130 persons — or 17 per cent, of the inhabitants — were attacked ; 
 besides 14 children infected in the village during their holidays, and who 
 sickened with typhoid after their return to schools in other places. 
 
 Except in six houses, which were supplied with water from their own 
 wells, the cases were pretty evenly distributed throughout the entire village, 
 and the above six houses were exempt from typhoid. This remarkable fact 
 threw suspicion upon the pubHc water-supply, which came from a spring at 
 the foot of the Stockhalden ridge, which is probably an old moraine of the 
 glacial epoch, and such a source might reasonably be regarded as above 
 suspicion of pollution. Observations upon a brook in the Flirlerthal Valley 
 and of the spring at Lausen showed, however, that there was a direct com- 
 munication between the two. Among the observations it was noted that when- 
 ever the meadows — below a hole spontaneously formed ten years before by 
 the giving way of the soil a little below the farmhouse — were irrigated with 
 water from the Fiirler brook, the volume of the Lausen spring became greatly 
 increased within a few hours. This irrigation had been carried on during 
 the summer, from the middle to the end of July, the brook being polluted by 
 the typhoid dejecta of the farmhouse patients. It was in direct communi- 
 cation with the closets and dungheaps of the infected house ; all the chamber 
 slops were emptied into it, and the dirty linen of the patients was washed 
 therein. It was observed, also, that the water supplied to Lausen was at first 
 turbid, acquired an unpleasant taste, and increased in volume. Three weeks 
 or so after the commencement of the irrigation the epidemic began in Lausen. 
 But Dr. Hagler did not rest satisfied with this evidence, and made the follow- 
 ing experimental demonstration of the correctness of the assumption that 
 the epidemic was due to the pollution of the Lausen water-supply by the 
 dejecta of the typhoid patients in Flirlerthal. The above-mentioned hole in 
 the Fiirler valley was opened, and the brook led into it ; three hours later the 
 
WATEB 271 
 
 fountains of Lausen gave out double their previous delivery of water. A 
 solution of 18 cwt. of common salt in water was now poured into the hole, 
 and soon the Lausen water was found to react more strongly for chlorides 
 than before ; the chlorine reaction went on increasing, and the proportion of 
 ealine matter in the fountains had increased threefold. All doubt as to the 
 passage of water from the fever-stricken Fiirlerthal to Lausen being thus 
 removed, the question as to whether the water found its way through natural 
 fissures, or percolated through porous strata, was attempted to be solved by 
 carefully and uniformly diffusing 2^ tons of flour through water, which was 
 then thrown into the hole. But neither an increase in the amount of solid 
 constituents nor any turbidity of the Lausen water was observed to result 
 from the addition. It appears to the writer, however, that this experiment, 
 in the face of the previously observed turbidity of the fountains whilst irriga- 
 tion was going on in the Fiirler valley, is not conclusive against the possi- 
 bility of the water finding its way from Fiirlerthal to Lausen by natural con- 
 duits. Two things this interesting epidemic does, nevertheless, prove beyond 
 doubt : first, that animal excreta do not, when taken in drinking-water, pro- 
 duce typhoid ; and next, that typhoid excreta may, when introduced into a 
 water-supply, induce typhoid in a distant community, when the water in its 
 passage is not freely exposed to the atmosphere. 
 
 It is perhaps unnecessary to introduce further instances in illustration 
 of the two important facts that typhoid fever may be spread by the use of 
 contaminated drinking-water, and that in places where typhoid fever has 
 been habitually prevalent, the disease may be practically eliminated by the 
 introduction of a pure water-supply. 
 
 DiAEEHCEA 
 
 That diarrhoea may result from the drinking of impure water, no sani- 
 tarian will doubt; The diarrhoea thus produced may be of a varied character, 
 and be due to a variety of causes. 
 
 1. Sulphuretted hydrogen in a water may cause diarrhoea. In the 
 Mexican war of 1861-2, such a form of diarrhoea was produced by the drink- 
 ing of water abounding in alkaline sulphides (Poncet). Medicinal sulphu- 
 retted waters (e.g. those of Harrogate) are well-known purgatives. Other 
 foetid gases in water (e.g. sewer gases) may produce a similar result. 
 
 2. Suspended matters, animal (ftecal), vegetable, and mineral, may cause 
 diarrhoea. Some of these — e.g. clay, mica, &c. — may act as simple mechanical 
 irritants, whilst suspended animal and vegetable substances may act speci- 
 fically upon the intestinal tract. 
 
 3. Dissolved Nitrogenous Organic Matter. — An excess of this, if of 
 animal origin, may provoke diarrhoea. That derived from cemeteries is gene- 
 rally supposed to do this in a marked manner. The writer's experience is, 
 however, that such dissolved matters are not generally more prone to do this 
 than other animal substances. 
 
 Dissolved vegetable matters appear to have no marked effect, except in 
 the case of peaty and marshy waters. Mr. Wanklyn, nevertheless, has 
 drawn attention to the circumstances of Leek Workhouse, where, for several 
 years, there was a general tendency to diarrhoea, which was not accounted 
 for until the water was examined and shown to be loaded with vegetable 
 matter ; and he also instances the case wherein a well on Biddulph Moor, 
 in the same district of Staffordshire, yielded on analysis only O-o grain of 
 chlorine per gallon — showing absence of any appreciable sewage contami- 
 nation — but yielded a rather considerable quantity of albuminoid ammonia 
 
272 HYGIENE 
 
 (0-14 part per million, or 0-0098 grain per gallon). Persons -who were in the 
 habit of drinking this water suffered fii-om diarrhoea (• Water Analysis,' 
 p. 49). 
 
 4. Dissolved Mineral Matters. — These, even when of the most simple 
 and innocuous character, when in excess may have a purgative effect, as is 
 seen in the case of many purgative medicinal waters. Sulphate of magnesium 
 and sulphate of calcium are most notable as producing this effect. The 
 illness produced may be of a specific character, as in the case of contamination 
 by lead (q.v., p. 250) or by chromium. 
 
 Dysentery 
 
 Impure water is credited with being a fertile source of dysentery. The 
 connection of this disease with the use of impure water has been recognised 
 for nearly a century. Cornuel records an outbreak of the disease at Guada- 
 loupe in 1847, caused by the use of impure water ; and the Walcheren fever, 
 in 1809, was associated by Da\ds (' On the Walcheren Fever'), ^dth the 
 drinking of impure brackish water. Chevers in India, Champouillon in 
 France, and McGrigor in the Spanish Peninsula, have each observed outbreaks 
 of dysentery from the same now well-recognised cause. Generally, it may be 
 stated that those forms of water-pollution— gaseous, soluble, and suspended 
 matters — which produce diarrhoea may, under other circumstances, produce 
 dysentery. 
 
 Affections op Mucous Membeanes 
 
 The effects of impurities in drinking-water are not limited to the in- 
 testinal tract, and may affect other portions of the alimentary and other 
 mucous membranes. Gastro-intestinal catarrh is, perhaps, not an in- 
 frequent result of the use of impure water. 
 
 Influence of Earthy and Metallic Impurities 
 
 These have already been sufficiently treated of under various headings 
 (see Lead, p. 256, Chromium, p. 256, and Magnesium Salts, supra). 
 
 Yellow Fever 
 
 It is most uncertain whether this disease is propagated by means of 
 ■water, the evidence as to this being conflicting. 
 
 Malaria from Water 
 
 Simple peaty water is not generally decidedly unwholesome, though it 
 not seldom produces temporary diarrhoea when drunk by those unaccustomed 
 to its use. Marsh-water has, however, from early times been considered 
 unwholesome and a provocative of disease. Hippocrates refers to the 
 popular notion in his time, that those who drink the water of marshes get 
 hard and enlarged spleens. The inhabitants of marshy tracts of country 
 are pretty generally agreed that these waters may produce fevers. Dr. 
 E. Parkes states that on inquiring in the malarious plains of Troy during 
 the year 1854, he was informed by the villagers that those who drank marsh- 
 waters had ague at all seasons, whilst those who drank pure water only got 
 ague during the late summer and autumn ; and he adds from his Eastern 
 experience that the same belief prevails in South India. Mr. Bettington, of 
 the Madras Civil Service, stated that it was notorious that marsh-water 
 
WATEB 273 
 
 produces fever and affections of the spleen ; and he instanced a notoriously 
 unhealthy village in which by simply digging a well the inhabitants were 
 freed from these maladies. 
 
 Indeed, medical literature, and especially the annals of the Indian and 
 British military services, abound in striking instances apparently pointing 
 the connection between marsh-water and aguish attacks as cause and 
 effect. 
 
 Nevertheless there are anomalies and apparent exceptions to this con- 
 nection, well deserving of more rigorous investigation than they have 
 hitherto received. Thus it is asserted that the water of the celebrated 
 Dismal Swamp of the North American Continent — a typically marshy water 
 — is not injurious to health, but is held in high estimation for use on board 
 ships. This instance is, however, inconclusive, since it is a notorious fact 
 that water charged with organic impurities, more especially of vegetable 
 origin, when stored undergoes a kind of fermentation which materially 
 alters its character, and may as the result render a highly impure water 
 palatable and wholesome. 
 
 The evidence as to the unwholesomeness of marsh water is to the writer's 
 mind conclusive. 
 
 GOITEE 
 
 That impure drinking-water is the cause of goitre has been a prevailing 
 opinion among physicians since early times ; and it is even stated that by 
 drinking certain waters French and Italian soldiers can produce that 
 disease, and so claim exemption from conscription. The evidence in 
 favour of goitre being caused by the use of certain kinds of drinking- 
 water is undoubtedly very strong, and probably well founded ; but the 
 nature of the substance which produces goitre is unknown. The absence 
 of iodine, and the presence of an excess of magnesium salts, also ex- 
 cessive hardness, have all been credited as exciting causes ; and yet each 
 one of these alleged causatives has been found absent in the waters drunk 
 by those living in goitrous districts. Thus iodine has been found present, 
 and Dr. J. B. Wilson found that at Bhagsoo, Dharmsala, India, where goitre 
 prevails, all the waters of the district are soft, non-calcareous, and 
 destitute of magnesian compounds (Aitkin's ' Science and Practice of 
 Medicine '). Usually, however, goitre prevails mostly in calcareous soils, 
 and especially where the water-supply is drawn from the magnesian lime- 
 stone formation. Nevertheless, goitre does not appear to be a prevalent 
 disease in Sunderland or in Bristol, towns which have water-supphes which 
 are hard, calcareous, and exceptionally rich in magnesium salts. 
 
 Evidently, the whole subject of the relation of goitre to water-supply 
 needs reinvestigation. A large mass of information on the subject is given 
 by Saint-Lager (' Sur les Causes du Cretinisme et du Goitre end<Jmique '). 
 
 Pabasitic Diseases 
 
 Impure Water, containing the ova of entozoa, &c., is a fertile source of 
 parasitic disease in warm climates, and perhaps to a much less extent in 
 the temperate climate of Great Britain, where, it must be admitted, water- 
 supplies are much less prone to contain the ova of entozoa, in consequence 
 of the less filthy habits of our people than in Poland, Eussia, and other 
 temperate climates. 
 
 The following is a list of the infecting organisms which have been alleged 
 to have been found in drinking-water : 
 
 VOL. I. T 
 
274 HYGIENE 
 
 1. Tania lata {Bothriocephalus lakts). 
 
 2. Distoma hepatlcum (fluke). 
 
 3. Ascaris lumbricoides (round worm). 
 
 4. Filiaria Dracunculus (Guinea-Avorm). 
 6. Filiaria sanguinis hominis. 
 
 6. Oxyuris vermicularis. 
 
 7. Dochviius duodenalis [Strongylns duodcnalis ; Sderostoma duodcnaU ; 
 Anchylostovmnn duodenale). 
 
 8. Billharzia hcematohia. 
 
 9. Sanguisuga medicinalis (the speckled leech), S. officinalis (the green 
 leech), and other species of leech. 
 
 WATER ANALYSIS 
 The Collection of Samples of ^YATER 
 
 The proper collection of samples of water for analysis is all -important 
 as regards the method of taking the samples, the cleanliness of the vessels 
 employed, and the quantities requisite. The quantity of water required for 
 an analysis will vary according to the kind of analysis which it is desired to 
 make. A full analysis of all the constituents is rarely required. Usually 
 half a gallon suffices for the purposes of an ordinary analysis for sanitary 
 purposes. 
 
 A glass-stoppered hottle of the kind known as the * Winchester Quart ' 
 is the best hottle to be used for the purposes of collecting and storing the 
 sample. These bottles hold rather more than half a gallon. A clean new 
 well-rinsed cork may be substituted for a stopper, if one be not at hand. 
 The bottle should be well cleansed, and rinsed with clean tap-water. It is 
 always undesirable to use an opaque vessel, such as a stoneware jug, for the 
 collection of samples of water, as their cleanliness and freedom from con- 
 taminating material can never be ensured. 
 
 Before filling the clean bottle with the sample, it should be rinsed three or 
 four times with the water to be collected before filling it with the actual 
 sample. Care should be taken to ensure the fairness of this, by pumping 
 to such an extent as to previously empty the barrel of a pump ; by careful 
 dipping in a stream ; and by avoiding disturbing the sand or mud at the 
 bottom of a well, spring, or rivulet. In rivers the sample should be taken 
 from mid-stream, avoiding the outlets of sewers and the inlets of tributary 
 streams. The vessel in which the sample is collected should be filled to 
 within half an inch of the cork or stopper, which should then be tied down 
 with tape or string, a seal being placed upon the knot, and another upon 
 the top of the stopper or cork so as to fix the string. No sealing-wax or 
 luting should be placed around the aperture of the bottle. 
 
 A ' tie-on ' luggage label, with description of the sample and the date, 
 should be affixed to the neck of the vessel, and secured by a seal. The use 
 of adhesive labels is attended with risk ; they are easily detached when 
 wetted, and an ignorant person may replace a label on a wrong bottle. 
 Moreover, the purposive transposition of labels by interested persons has 
 been known to occur. 
 
 For special purposes, and where a mineral analysis is required, a larger 
 quantity of water may be necessary — a gallon or more. 
 
 In collecting samples of water for bacteriological examination, flasks of 
 three or four ounces' capacity maybe employed. These are cleansed, plugged 
 
WATEB '^75 
 
 with cotton-wool, and then sterihsed. The plug is removed by means of 
 the fingers or sterihsed forceps when the sample is collected, taking care 
 not to touch the interior of the neck of the flask with the fingers. About 
 an ounce of the water is introduced by means of a sterilised pipette, and the 
 plug replaced ; the top of the flask may then be secured by means of a 
 caoutchouc cap which has been kept in a 1 in 1000 solution of corrosive 
 sublimate. The flasks are transported with difficulty, since the sample 
 should at no time be allowed to touch the plug. A glass bulb with a slender 
 neck forms a better receptacle when the sample has to be transported to a 
 distance ; the bulb being hermetically sealed, as recommended by Magnin 
 and Sterberg (' Bacteria,' p. 175). 
 
 In the case of spring and well waters, the nature of the soil, subsoil, and 
 geological characters of the locality should be carefully noted. 
 
 The analysis should be made at the earhest possible opportunity. If 
 delayed, ammonia may decrease, or nitrates may in part disappear, odour may 
 be lost, and deposit may take place owing to escape of carbonic acid gas or 
 absorption of oxygen, or from both causes. 
 
 Gases 
 
 A determination of the nature of these is not frequently necessary, and a 
 quantitative determination of each of them is seldom of much service for the 
 purposes of sanitation. If required, special precautions are necessary, and 
 some of the operations must be conducted at the spring or well, as the case 
 may be. The presence of any special odorous gas such as sulphuretted 
 hydrogen may be noted. 
 
 Pkbliminaby Examination 
 
 Colour and Appearance. — This is best observed in a clear glass tube, 
 two feet long and two inches in diameter, closed at one end by a plate of thin 
 colourless glass, cemented on to the tube with an uncoloured cement. By 
 placing the tube on a piece of white printed paper, such as the page of a 
 book, the colour of the water, its transparency or turbidity, and other points 
 connected with its appearance, may be readily noticed. By only half-filling 
 the tube, so that the lower half contains water and the upper half air, and 
 placing the tube in a good light, and backed by a piece of white paper, further 
 information as to the tint of the water will be obtained. 
 
 Odour. — Some waters exhale special odours even in the cold, such, e.g. 
 as sulphuretted waters. When no odour can be thus perceived, put 100 c.c. 
 of the sample into a clean wide-mouthed stoppered bottle holding 200 c.c, and 
 raise the temperature to about 100° Fahr. (38° C). Shake vigorously, remove 
 the stopper, and immediately apply the nose to the botttle. Some polluted 
 waters when thus treated give off distinct and easily recognisable odours. 
 
 Turbidity. — If a water be turbid, the nature of the turbidity should be 
 ascertained ; and if considerable, its quantity should be determined. For the 
 former purpose about 200 c.c. of the water may be placed in a tall conical 
 glass, and the deposit allowed to subside, the vessel being kept carefuUy 
 covered so as to avoid access of dust. A small quantity of the deposit may 
 then be removed by a pipette and subjected to microscopical examination. The 
 supernatant water may then be siphoned off and the residue treated with 
 hydrochloric acid so as to ascertain whether it is chalky matter or insoluble 
 clay, sand, or earth. 
 
 In order to determine the amount of suspended matter, a definite volume 
 of the water — say a litre — is filtered through a tared Swedish paper filter 
 
 i2 
 
276 HYGIENE 
 
 the residue dried at 130° C. (100° C. Frankland) and weiglied. On deducting 
 the tare of the filter, and multiplying by the necessary factor to reduce the 
 quantity to 'grains per gallon,' or 'parts per 100,000' if desired, the 'total 
 suspended matter ' is obtained. 
 
 By incinerating the filter with the deposit, moistening -^th solution of 
 carbonate of ammonium, and drying at a heat below dull redness (or at. 
 180° C), deducting the weight of a similar filter-ash, the ' mineral suspended 
 matter ' is obtamed. The difference between the total and the mineral sus- 
 pended matter is the ' organic suspended matter.' 
 
 MiCEOSCOPiCAL Examination of Deposits 
 
 This important operation should never be omitted in the analysis of a 
 water, as by its means very valuable information will frequently be obtained, 
 both of a positive and of a negative character : positive when organisms of 
 definite character are found pointing to organic pollution ; and negative 
 when a turbidity or deposit objectionable to the eye is ascertained to be due 
 to inert mineral matter removable by a simple process of filtration. 
 
 When a water is highly tm'bid, a sufficient quantity of deposit may readily 
 be obtained for microscopical examination, but it is otherwise when the 
 amount of tm-bidity is slight ; and this is most commonly the case with an 
 ordinary drinking-water. In such cases the method recommended by Dr. 
 Macdonald may be employed. (' Microscop. Exam, of Drinking Water,' p. 1.) 
 A tall glass vessel holding half a litre or a litre is filled with the sample, and 
 a circular disc of glass resting upon a horizontal loop at the end of a long 
 wire is let down to the bottom of the glass, and the whole apparatus is 
 covered and set aside for twenty-four hours, or longer if necessary. At the 
 end of this time the water is syphoned off, only leaving a thin stratum over the 
 glass disc, which is gently raised, and laid on a sheet of blotting-paper so as 
 to dry its under-surface, when it may at once be transferred to the stage of 
 the microscope after covering the deposit with a large thin covering-glass. 
 Instead of a disc of glass, an ordinary microscope shde may be employed ; 
 but its form is not convenient for immersion. Generally, however, it suffices 
 to allow the sample to deposit in a large stoppered collecting-bottle, such as 
 a Winchester quart. The water is then in greater part syphoned off into 
 another bottle, and the remainder with the deposit is poured into a conical 
 glass, which is covered and set aside. The deposit can then be easily 
 removed by a pipette in sufficient quantity to be transferred to a slide, and 
 submitted to microscopical examination. A :|th or ^th inch objective will 
 usuaUy suffice for the examination, and many organisms are better seen when 
 a lower power is used. It must be remembered that this examination does 
 not supersede a bacteriological examination (see p. 296). 
 
 The objects thus seen are very varied : angular, crystalline, and rounded 
 mineral particles ; the pollen of flowers ; epidermic and deeper tissues 
 of plants ; fibres of linen, cotton, silk, and wood ; vegetable living or dead 
 organisms, from the minute bacterium to strings and filaments of confervoid 
 plants ; diatoms ; animal fibres and organisms of varied type and conforma- 
 tion ; ova of animals, &c. For a full description of these we must refer to> 
 other works, and especially to the one already referred to : ' A Guide to the 
 Microscopical Examination of Drinking Water,' by Dr. J. D. Macdonald. 
 2nd ed. 1883. 
 
 Under certain conditions the microscopical exammation of water may 
 afford valuable negative, if not positive, results. Thus, for example, it may 
 be important to ascertain whether a water contains cholera-evacuations. In 
 
WATEE 277 
 
 this case plate cultivations may be made, and if the characteristic Asiatic 
 cholera spirillum be obtained and distinguished from other comma-shaped 
 bacilli, its presence will indicate that the water contains cholera- evacuations, 
 whatever be the view held as to the causation or non-causation of cholera by 
 that spirillum, which is at all events pretty generally accepted as being an 
 accompaniment of true cholera. 
 
 The microzyme test as hitherto usually employed is valueless, viz. the 
 test of adding a few drops of the sample of water to a small quantity of 
 Pasteur's nourishing fluid previously boiled in a sterilised tube. The subse- 
 quent milkiness developed in the liquid only proves that the water contains 
 micro-organisms or their spores, and these are present even in ice and 
 in ordinary potable waters : hence no results of real value are obtainable in 
 this way. 
 
 Taste 
 
 The taste and palatability of a water is important to be noted. It is not 
 advisable, however, to taste a water when there is reason to apprehend that 
 it is specifically polluted. 
 
 The taste of a water depends much upon the quantity and quality of its 
 saline constituents ; and still more on the gaseous constituents. Imperfectly 
 oxidised organic impurities, such as sewage, may confer special odours on a 
 "water. 
 
 Acidity, Neutbality, or Alkalinity 
 
 Most waters react faintly alkaline to dehcate neutral tint litmus-papers. 
 Eain- waters and peaty waters are generally slightly acid in reaction. 
 
 If it be desired to determine the extent of acidity of a water, this may 
 be done by placing half a litre in a flask provided with a reflux condenser, 
 and boihng the water vigorously for fifteen minutes or so, to expel carbon di- 
 oxide. The acidity is then determined by running in decinormal soda solution 
 from a burette, using phenol-phthalein as an indicator. Some analysts 
 prefer to use methyl-orange to determine the point of neutrality. By operat- 
 ing on two separate half-litres, using the two indicators respectively, a dis- 
 tinction may be made between mineral and organic acids. 
 
 Total Solids ok Saline Constituents 
 
 A platinum basin capable of holding 350 cubic centimetres is cleaned, 
 rinsed with distilled water, dried in an air-oven at 130° C, cooled in an exsic- 
 cator over sulphuric acid, quickly weighed, and the tare of the dish noted. 
 250 c.c. of the water under examination are pipetted into the basin, and 
 evaporated to dryness. This is best done entirely on the water-bath, but may 
 be partially effected over a naked flame. In all cases the completion of the 
 evaporation must bo effected on the water-bath. The dish with its contents 
 when dry is transferred to an air-oven heated to 130°, 150°, or 180° C, till it 
 practically ceases to lose weight, or for a definite period, say half an hom-. 
 Various analysts have recommended each of the above-named temperatures ; 
 but the temperature of 130° C. is the one most commonly adopted. At this 
 temperature hydrated sulphate of calcium readily gives up three-fourths of 
 its water, and undergoes no further loss below 200° C. — an inadmissible tem- 
 perature for drying a water residue. This last temperature is, moreover, 
 requisite for the complete dehydration of chloride of calcium. But whatever 
 be the temperature employed, it is well to note it in the analytical report, so 
 that the results may be compared with those of other analysts. The dish 
 
278 HYGIENE 
 
 and contents are again cooled in the exsiccator, and rapidly weighed. The 
 dijfterence between the new weight thus obtained and the original weight of 
 the dish is, of course, the weight of the sohds in 250 c.c, of the water, which, 
 multiplied by 280 and by 400 respectively, gives the solids in grains per gallon 
 and in parts per 100,000 respectively. 
 
 Dr. Frankland recommends the evaporation of 500 c.c. of the sample, 
 with special precautions, and the drying of the evaporated residue in the 
 water-oven at approximately 100° C. for three hours, in order to obtain the 
 total solids (' Water Analysis,' p. 17). Mr. Wanklyn, on the other hand, uses 
 70 c.c. only, and dries for ten minutes only in the water-oven. His published 
 analyses by this method, which he says are ' very concordant,' show weigh- 
 ings made apparently to the extraordinary minuteness of 0*01 milligramme. 
 70 c.c. is too small a quantity to use when anything nearer than a rough 
 approximation to total solids is desired. 
 
 Loss on Ignition (also sometimes termed ' organic matter and water of 
 hydration '). — This determination is obtained with the greatest accuracy by 
 placing the platinum basin with its solid contents resting on a clay triangle 
 inside a larger dish, over which is suspended at a short distance a plate 
 of platinum, and gently heating the outer dish by means of an argand burner. 
 The outer dish may ordinarily be dispensed with, care being taken to avoid 
 a heat exceeding that of dull redness, otherwise alkaline chlorides may be 
 volatilised. The heat must be continued till all sooty particles are dissipated. 
 The evolution of ruddy fumes, indicating the presence of nitrates or nitrites, 
 is noted, and also the production of special odours, such as those of burning 
 nitrogenous organic matter. In this way valuable information may be 
 obtained. With care, no loss occurs from the decomposition of carbonates ; 
 but it is always advisable to moisten the incinerated residue with a solution 
 of carbonate of ammonium, dry, and again very gently incinerate, so as to 
 insure the full carbonation of the residue ; and when the water abounds in 
 nitrates this treatment with carbonate of ammonium is indispensable. When 
 cold, the weight of the dish and its contents deducted from the similar 
 weight of the dish plus the total solids gives the loss on incineration, which 
 is then calculated into parts per 100,000, or grains per gallon if desired, by 
 multiplying by 400 or by 280 respectively. It is customary to disparage the 
 value of this determination, but it is one which an experienced analyst will 
 never omit ; and by observing the manner in which the incmeration progresses, 
 the gases and vapours given off, &c., much valuable information may be 
 gained as to the kind of organic matter present in the water. 
 
 When the water contains considerable quantities of nitrates, a correction 
 is necessary owing to the substitution of the radical CO2 for the radical N2O5 
 in the nitrates ; CaO. NgOg, for example, having the molecular weight 164, 
 becomes CaO. CO2, having the molecular weight 100. The rule is to deduct 
 from the experimental loss on ignition 2-29 for each unit of ' nitrogen as 
 nitrates and nitrites ' present, or 0'59 for each unit of nitric acid, N2O5. In 
 the case of many magnesian waters, the loss on ignition is increased 
 by the loss of hydrochloric acid during evaporation, aqueous chloride 
 of magnesium being converted on evaporation into magnesia, with loss of 
 hydrochloric acid. 
 
 Chloeine 
 
 This is best titrated by means of a standard solution of nitrate of silver, 
 each 1 c.c. of which will precipitate O'OOl gramme of combined chlorine. 
 The solution is prepared by dissolving 4*79 grammes of recrystalhsed nitrate 
 of silver in distilled water, and making up with additional water to the^ 
 
WATER 270 
 
 volume of a litre. Its exact strength is determined from time to time by 
 setting it against a standard solution of chloride of sodium, containing 1"648 
 gramme of ignited (not fused) clean rock-salt crystals, in a litre of distilled 
 water. Or pure chloride of sodium may be prepared by precipitating 
 a saturated solution of common salt by passing a current of hydrochloric 
 acid gas into it, and then collecting, rinsing with distilled water, and drying 
 at 300° C. the crystals which have been thrown down from the solution. 
 
 In performing the analysis, 50 c.c. of the water is pipetted into a white 
 porcelain dish, and one or two drops of a half- saturated solution of neutral 
 yellow chromate of potassium added. The chromate solution when acidu- 
 lated with nitric acid must remain perfectly clear when a drop of the solution 
 of nitrate of silver is added to it, proving the absence of chlorides. If now 
 the standard solution of nitrate of silver be run from a burette into the 
 water to be analysed, and to which the chromate has been added, a red pre- 
 cipitate of chromate of silver will be formed around the inflowing solution, 
 but will quickly disappear on stirring the liquid in the dish, the red chromate 
 of silver being decomposed, and white chloride of silver formed, so long as 
 any chloride remains in solution. But when the chlorine is all converted 
 into chloride of silver, the slightest excess of the standard solution instantly 
 strikes a red colour, due to the permanent precipitation of chromate of 
 silver. Hence the chromate acts as an indicator, and when the slightest 
 tinge of red colour is visible on stirring the Uquid, the reaction is terminated, 
 and the quantity of standard solution that has been added is read off. The 
 number of cubic centimetres added multiplied by 1*4 gives the grains of 
 chlorine per gallon, and by 2 the parts of chlorine per 100,000. The quan- 
 tity of chlorine multiplied by 1*648 gives the amount of chloride of sodium 
 which is equivalent to the combined chlorine present. 
 
 It is well to discharge the colour of the liquid in the dish on the comple- 
 tion of the titrations by adding a few drops of a solution of chloride of sodium,, 
 and repeating the titration in another dish on a fresh quantity of the water. 
 When the two dishes are viewed side by side, any shade of difference in the 
 colour of the solutions will be easily perceptible. 
 
 Some analysts prefer to use a decinormal silver solution (17 grammes of 
 nitrate of silver per litre) and operate on a large volume, say 250 c.c, of the 
 water. Each 1 c.c. of this solution precipitates '00355 gramme of chlorine ; 
 hence if 250 c.c. of water be used for titration, the number of cubic centimetres 
 of silver solution multiplied by 0*994 gives the grains of chlorine per gallon, 
 or by 1*42 the parts of chlorine per 100,000 of water. 
 
 Dr. Frankland uses a solution of half the strength here recommended, 
 using 50 c.c. of the water for titration. Each 1 c.c. of his nitrate of silver 
 solution = 0*0005 gramme chlorine (' Water Analysis,' p. 20). 
 
 NiTEATES 
 
 1. Indigo Process. — A standard solution of indigo is prepared by dissolv- 
 ing commercial indigo -carmine in water containing 5 per cent, by volume of 
 sulphuric acid, and boiling for some time so as to sterilise the solution. It 
 is then standardised against a very dilute solution of nitrate of potassium, 
 which may be conveniently made of such a strength that 1 c.c. = •0001 
 gramme NoO^, or a solution containing 0*187 gramme nitrate of potassium 
 in a litre of water. In diluting the indigo solution to the proper strength, 
 distilled water containmg 5 per cent, by volume of sulphuric acid should be 
 used. When thus prepared the solution keeps well. The process is conducted 
 as follows : 
 
280 HYGIUNE 
 
 20 c.c. of the water (or to standardise the indigo, 10 c.c. of nitrate of 
 potassium solution and 10 c.c. distilled water) are measured into a beaker 
 of about 100 c.c. capacity, standing in a small flat porcelain dish ; 1 c.c. of 
 standard indigo solution is run in from a burette, and then 21 c.c. of strong 
 sulphuric acid (free from oxides of nitrogen and of sp. gr, l'8-4) are cautiously 
 poured in, so as not to mix with the liquid in the beaker. As soon as the blue 
 colour of the indigo begins to fade, the mixtm-e is stirred, when the tempe- 
 rature rises to 120°-130° C. The indigo solution is then rapidly run in 
 from the burette till a permanent blue colour remains. The volume of 
 indigo solution required is noted : say 10 c.c. A fresh 20 c.c. of water is 
 taken, 10 c.c. of indigo solution added, and a volume of sulphuric acid equal 
 to the whole (30 c.c.) cautiously added, and the mixture stirred as soon as 
 decoloration commences. 
 
 The process is repeated until, in the final experiment, the volume of in- 
 digo solution added to the 20 c.c. water in the beaker, on mixing Avith a 
 volume of sulphuric acid equal to the bulk of water plus indigo solution, 
 leaves a faint blue tint after stirring. In each experiment the bulk of acid 
 used must equal the volume of liquid to which it is added, in order to attain 
 the proper temperature on mixing. The number of c.c. of indigo solution 
 used multiplied by 0-5 gives parts per 100,000, or by 0-35, grains per gallon 
 of N2O5. 
 
 In cold weather it is advisable to slightly warm the mixture of indigo 
 solution and water before adding the acid. 
 
 Should a water require more than about 10 c.c. indigo solution for 20 c.c. 
 water, the sample should be appropriately diluted. For very small quantities 
 of nitrates a dilute solution of indigo may be used — -^th or y o^h the strength 
 of the above solution — the operation bemg conducted in the manner already 
 described. 
 
 2. Phenol- Sulphuric Acid Method. — This method is simple in its applica- 
 tion, and yields good results. Phenol- sulphuric acid is prepared by melting 
 absolute phenol, and pouring two parts, by measure, of the liquefied phenol 
 into five volumes of pure concentrated sulphuric acid free from nitrates, when 
 the whole is digested for eight hours in a water-bath kept boiling. The 
 mixture is then allowed to cool, and to each two volumes of the liquid is 
 added one and a half volumes of distilled water, and half volume of pure 
 strong hydrochloric acid solution. The light brown solution thus obtained is 
 ready for use. The following is a good mode of procedure (' Chem. News,' 
 1890, vol. 61, p. 15). 
 
 10 c.c. of the water under examination and 10 c.c. of a standard solu- 
 tion of nitrate potassium (0'7215 gramme per litre) are pipetted into two 
 small beakers, and placed near the edge of a hot plate. When nearly 
 evaporated, they are removed to the top of the water-oven and left there till they 
 are evaporated to complete dryness. As this operation usually takes about an 
 hour and a half, it is better, when time is an object, to evaporate to dryness 
 in a platinum dish over steam. The residue in each case is then treated 
 Avith 1 c.c. of the phenol-sulphuric acid, and the beakers are placed on the 
 top of the water-oven. If the water under examination contains a large 
 quantity of nitrates, the liquid speedily assumes a red colour, which in a 
 good water will not appear for about ten minutes. After standing for fifteen 
 minutes the beakers are removed, the contents of each washed out successively 
 into a 100-c.c. measuring-glass, a slight excess (about 20 c.c.) of ammonia 
 solution (sp. gr. 0*96) added, the 100 c.c. made up by the addition of water, 
 and the yellow liquid transferred to a Nessler glass (6 in. x 1^ in.). The 
 more strongly coloured liquid is then partly transferred to the measuring- 
 
WATEB 281 
 
 glass again, and the tints compared a second time. In this way the tints 
 ■are adjusted, and, when as far as possible matched, the liquid that has 
 been partially removed is made up to the 100 c.c. mark with water, and, 
 after well mixing, finally compared. If not of exactly the same tint, a new 
 liquid can at once be made up, probably of exactly the same tint, as the first 
 experiment gives very nearly the number of c.c. of the one equivalent to 
 the 100 c.c. of the other. Each 1 c.c. of the nitrate solution used = 0-0001 
 gramme N. 
 
 In the case of very good waters, 20, 50, or more c.c. should be evaporated 
 to a small bulk, rinsed into a small beaker, and evaporated to dryness, and 
 treated as above — only 5 c.c. of the standard nitrate of potassium (= 0*5 N 
 in 100,000) being taken. In the case of very bad waters, 10 c.c. should be 
 pipetted into a 100 c.c. measuring-flask, and made up to the mark with 
 distilled water, then 10 c.c. of the well-mixed liquid (= 1 c.c. original water) 
 withdrawn, and treated as above. 
 
 3. Aluminium Process. — This is the process recommended by Mr. Wanklyn. 
 It is thus performed : Caustic soda is prepared free from nitrates by dissolving 
 metallic sodium in water, 2 grammes of the metal being used for each 100 
 c.c. distilled water, which is then boiled to expel ammonia. A definite volume, 
 say 50 c.c. or 100 c.c, of the water to be examined is mixed with its own 
 volume of this soda solution, and a piece of aluminium-foil, more than the 
 liquid will dissolve, is placed in the mixture and allowed to remain for several 
 hours. The hquid is then distilled, and in the distillate the ammonia 
 formed by reduction of the nitrates is titrated by means of Nessler's solution. 
 Each unit of ammonia found corresponds to 0-8235 unit of ' nitrogen as 
 nitrates,' or to 3'176 units of N2O5. If 100 c.c. of water were employed, by 
 anultiplying the results obtained by 700 the number of grains per gallon is 
 obtained ; or by moving the decimal three places to the right, we get parts 
 per 100,000. 
 
 In using the process Dr. Frankland advises the use of a 10 per cent, 
 solution of soda, made free from nitrates by dissolving 4 inches square of 
 aluminium-foil in it, and boiling off one-third of the liquid. In the actual 
 performance of the analysis 100 c.c. of the water are treated with 10 c.c. of 
 the above soda solution, evaporated to one-fourth, and then treated with 
 2 inches square of aluminium-foil for six hours before distilling off the 
 ammonia (' Water Analysis,' p. 30). 
 
 4. The Zinc-Copper Couple Method. — This method, devised by Dr. 
 Gladstone and Mr. Tribe, depends upon the electrolytic reduction of nitrates 
 io ammonia by means of a couple of the two metals copper and zinc, 
 which is prepared as follows : A mixture of 2 grains of finely divided reduced 
 •copper with 18 grains of coarse zinc filings is introduced into a 2 oz. flask 
 fitted with a cork, through which passes a tube drawn out to a capillary 
 -opening. The flask is heated over a burner till the zinc begins to soften, 
 shaking gently all the time to ensure thorough mixture of the two metals, 
 and to prevent any part being overheated. The mass, when the operation 
 is finished, should consist of greyish-black grains, without metallic lustre. 
 If the mass has a brassy tint, or if the zinc filings retain their form, the 
 product must be rejected. As soon as the desired result is obtained, the 
 flask is removed from the flame, continuing the agitation for a few seconds 
 to prevent fusion. The point of the capillary tube is then sealed, and the 
 flask allowed to cool. 
 
 In performing the analysis 250 c.c. of the water may be evaporated over 
 .a naked flame to about the volume of 25 c.c, a fragment of quicklime about 
 .the size of a hemp seed added, and the evaporation renewed till the bulk is 
 
282 HYGIENE 
 
 reduced to 6 or 7 cc The whole is then rinsed into an 8 oz. distilhng-flask, 
 and the requisite amount of zinc-copper couple added. The flask is closed with 
 a cork, and attached to a small Liebig's condenser, and the water nearly all 
 distilled off. Hot distilled water is added at intervals, and the distillation 
 renewed till 100 cc. of distillate is obtained. This after appropriate dilution 
 of a fraction, say 5 cc, made up to 50 cc, is then nesslerised. 
 
 5. FranklancV s Process. — Dr. Frankland estimates the total amount of 
 nitrogen present in the form of nitrates and nitrites by a method — that of 
 Crum — based upon the reduction of the acids of these salts by means of 
 mercury. A litre, or even half a litre, of the water is evaporated to a small 
 bulk, sulphate of silver is added to precipitate chlorides, and the mixture is 
 filtered. When the water contains nitrites, these are converted into nitrates 
 before the evaporation by means of permanganate of potassium. The filtered 
 liquid is evaporated to a bulk of 2 or 3 cc, and transferred to a glass tube 
 open at one end, and furnished with a stopcock and fmuiel-shaped mouth at 
 the other end. The tube is filled with mercury, the stopcock being closed, 
 inverted in the mercury trough, so that the funnel-shaped mouth is upwards, 
 and the Avater residue is introduced into the funnel and run into the tube, 
 the vessel in which the residue is contained being rinsed Avith Avater, and 
 then 3 or 4 cc of strong sulphuric acid (free from nitro-compounds) are 
 introduced into the fmmel and tube. Care must be taken to avoid the 
 introduction of air into the tube, which is noAV closed, Avhilst in the trough, 
 by means of the thumb. The tube is now removed from the trough and 
 vigorously shaken by a semi-rotary motion, so as to keep an unbroken 
 column of at least an inch of mercury below the acid liquid. The pressure 
 exerted by the liberated nitric oxide is, as far as possible, resisted by the 
 opposing pressure of the thumb. At the end of five minutes the reaction is 
 completed, the gas is transferred under mercury to a suitable eudiometer, 
 and its volume measured. 
 
 Nitrites 
 
 These are best determined by meta-phenylene diamine, the hydrochlorate 
 of AA^liich may noAV be purchased in a state of suificient purity for the analysis. 
 1 gramme of the salt is dissolved in 200 cc. of water acidulated Avith sul- 
 phuric acid. The other solutions required are — dilute sulphuric acid (1 vol. 
 acid to 2 vol. water), and a solution of nitrite of potassium. This solution is 
 prepared by dissohing 0*405 gramme recrystallised nitrite of silver in hot 
 water, precipitating Avith a slight excess of chloride of potassium, cooling, 
 and making up Avith distilled Avater to a litre ; allowing the chloride of silver 
 to settle and decanting. For use, 100 cc of the clear liquid is diluted with 
 distilled Avater to a litre. Each 1 cc of the diluted solution is the equivalent 
 of O'Ol milligramme of N2O.;. 
 
 To estimate the nitrites 1 cc of each of the first two solutions is added 
 to 100 cc of the Avater placed in a nesslerising cylinder, Avhen, if nitrites h& 
 present, a yellowish-red colour is produced. This must not be deeper than 
 a just clearly recognisable tint : if deeper than this, a smaller quantity of the 
 water than 100 cc must be taken and diluted with distilled Avater to this 
 volume. The tint is compared Avith that given by a definite quantity of the 
 standard solution of nitrite made up to 100 cc and treated AA'ith 1 cc 
 each of the meta-phenylene diamine solution and the dilute sulphuric acid. 
 Supposing 100 cc of the Avater gives the same tint as 9 cc of the standard 
 nitrite solution in 100 cc of hquid: then O'Ol x 9=0-09 milhgramme N^Og 
 in the 100 cc and 0-09 x •7=0-063 grain N,0:j per gallon. The N0O3 xO-37 
 =N : thus the above water contained 0-003 x 0-37=0-023 grain N as NoOg. 
 
WATEE 283 
 
 per gallon. This test is not readily applicable when the water is coloured, 
 as, e.g., with peaty matter. 
 
 Dr. Thresh has recently devised a method of determining the quantity of 
 nitrites in water by means of iodide of potassium in an atmosphere of coal 
 gas, and titrating the hberated iodine by means of thiosulphate (hyposulphite) 
 of sodium and starch. The apparatus used is the one which he has devised 
 for the estimation of free oxygen in waters. According to Dr. Thresh, the 
 results obtained are accurate (' Jour. Chem. Soc' vol. 57, 1890, Trans, p. 185). 
 
 Ammonia 
 See * The Albuminoid Ammonia Process,' p. 285. 
 
 Oeganic Matter 
 
 This is the most important constituent to be determined from a sanitary 
 point of view, and the one as to which the most serious discrepancies of 
 opinion have existed. There are three chief methods of estimating organic 
 matter in water, or rather of estimating the relative quantities in different 
 waters ; for few will claim that any known method will estimate the absolute 
 quantity of organic matter present. These methods are the combustion pro- 
 cess, commonly known as Frankland's, and its modifications ; the albuminoid 
 ammonia process, devised by Mr. Wanklyn ; and Forchammer's permanganate 
 process. Eecently, a new method, that of Kjeldahl, has been introduced. 
 These methods will now be described. 
 
 Frankland's Process. — Dr. Frankland claims for his process that it is the 
 only one which determines with anything like precision the total quantity of 
 organic carbon and organic nitrogen present in a water, i.e. the carbon in 
 forms other than that of carbonates, and the nitrogen in other forms than 
 those of ammonia, nitrites, or nitrates ; and hence that it affords a measure 
 of the carbon and nitrogen present in the organic compounds present, and 
 so, indirectly, of the absolute quantity of organic matter in a water. In this 
 process the organic carbon is oxidised and obtained as carbon dioxide, and the 
 organic nitrogen is hberated in the free gaseous state and measured. It is 
 further claimed that the proportion of organic carbon to organic nitrogen 
 enables the analyst to judge as to whether the organic matter is of vegetable 
 or animal origin, since animal matters as a rule are richer in nitrogen than 
 vegetable matters. But every one of these claims has been vehemently con- 
 tested. 
 
 In the first place, although it is indubitable that when stable carbon 
 compounds, such as quinine and sugar, are added to a water, the carbon 
 in the latter and the carbon and nitrogen in the former can be deter- 
 mined by the Frankland combustion process with a reasonable amount of 
 accuracy, it is by no means certain that the minute quantities of carbon and 
 nitrogen present in sewage can be determined with anything like the same 
 amount of precision ; and it is possible that, during the necessary evaporation 
 to dryness of a large volume of water, unstable and readily decomposable 
 bodies may undergo decomposition, and be lost so far as analysis is concerned. 
 This criticism has never been satisfactorily refuted ; and altJaough in a great 
 majority of instances it may have no value, it is probable that in some in- 
 stances it may have greatf orce. As to the value of the assertion that a 
 higher proportion of nitrogen to carbon is found in animal as compared with 
 vegetable matter, the whole validity of the comparison based on the ratios 
 of these two elements present rests upon the assumption that the absolute 
 
284 HYGIENE 
 
 amounts of carbon and nitrogen are both determined ; and, as has been ah-eady 
 intimated, this has not been proved. It is remarkable, too, that in sea-water 
 the ratio of organic nitrogen to organic carbon is very high indeed — an asserted 
 characteristic of animal, and assuredly of deleterious, organic matter. Yet it 
 can scarcely be supposed that the organic matter in sea-water is chiefly or 
 entirely noxious animal matter, any more than the organic matter in river- 
 water unpolluted with sewage. Yet the Frankland process would per se lead 
 us to suppose that sea-water is dangerously polluted with animal matter. 
 Frankland's organic-combustion process is one which requires great care and 
 exactitude in its execution. It cannot be entrusted to the hands of any but 
 those accustomed to its working, and skilled in minute gas analysis. Hence 
 it is seldom employed by the Medical Officer of Health. For a full description 
 of its operations we must refer our readers to the description of its author, 
 Dr. Frankland (' Journ. Chem, Soc' vol. 21, p. 77 ; ' Sixth Eeport of Elvers 
 Pollution Commissioners,' p. 501, and ' Water-Analysis : ' London, 1890). 
 The outlines of the process are as follows. 
 
 A Htre of the water is mixed with 30 c.c. of a freshly saturated solution of 
 sulphurous acid, and boiled for a few minutes. Such a solution of sulphur- 
 ous acid can be readily and rapidly prepared by passing the gas from a 
 syphon of liquefied sulphur dioxide into distilled water ; and these syphons 
 are now articles of commerce. By the above treatment the carbonates are 
 decomposed and carbonic acid expeUed. When the water contains httle or 
 no carbonate, 0*2 gramme of sulphite of sodium are added before evapora- 
 tion, to ensure the saturation of any sulphuric acid formed during the 
 evaporation to dryness. A few drops of a solution of ferric chloride are also 
 added before evaporation ; and thus the whole of the nitrogen existing as 
 nitrates and nitrites is expelled. 
 
 The dry residue is mixed with a few grammes of chromate of lead, and 
 the mixture is transferred to a combustion tube sealed at one end. The 
 remainder of the tube is then charged with cupric oxide and copper turnings 
 in the manner usually followed in making an organic combustion. The open 
 end of the tube is then drawn out in the blowpipe flame, and connected with 
 a Sprengel's mercury pump by means of a piece of caoutchouc tubing, and 
 the connection immersed in a vessel of water. The front part of the tube is 
 then heated, and the pump worked for five or ten minutes until a good 
 vacuum is obtained. An inverted glass tube, filled with mercury, is now 
 placed over the dehvery end of the tube of the pump to coUect the gaseous 
 products, and the combustion is made in the ordhiary manner, an hour 
 being usually taken for the operation, when it will be found that unless much 
 organic matter is present in the water no gas will have passed into the 
 collecting-tube ; and the pump has to be again worked for five or ten minutes 
 to transfer the gas into the collecting-tube. The quantities of carbonic acid 
 and nitrogen gases are then respectively determined in the gaseous mixture 
 by the ordinary process of gas analysis. The quantities of gases thus ob- 
 tained represent the organic carbon and organic nitrogen and the nitrogen 
 of ammonia present in a litre of water. The ammonia is separately deter- 
 mined (see p. 286), and the corresponding quantity of nitrogen deducted from 
 tbe total combined nitrogen. 
 
 For correction for errors of manipulation and apparatus we must refer 
 our readers to the original paper ; and, indeed, no unskilled analyst, nor any- 
 one unaccustomed to the necessary manipulations and the sources of error, 
 should undertake to perform an analysis by the Frankland combustion 
 process— an operation at all times requiring gi*eat delicacy of manipulation. 
 
 Dupre and Hake (' Journ. Chem. Soc' 1879, p. 159) have simphfied the 
 
WATER 285 
 
 combustion process, without sacrificing its delicacy and accuracy. An appro- 
 priate quantity of the water to be analysed is evaporated to dryness after 
 acidification with phosphoric acid, and the residue transferred to a platinum 
 boat and then placed in a combustion tube 24 inches in length, prepared as 
 follows : — The tube is filled for half its length with granulated cupric oxide, 
 which is kept in position by an asbestos plug. The tube is then drawn out 
 and bent downwards in front to an angle of 120°, and is then attached to a 
 Pettenkofer's absorption tube charged with baryta-water, the other being 
 attached by means of a flexible tube to a reservoir of oxygen gas. The tube 
 is heated to redness, whilst a stream of oxygen is passed through it until the 
 issuing gas ceases to render the baryta-water turbid. The posterior end of 
 the tube is now opened and the platinum boat containing the water residue 
 is quickly inserted. Another Pettenkofer's tub© charged with a 2 per cent, 
 solution of subacetate of lead is changed for the baryta-water tube ; and the 
 combustion is then made in a stream of oxygen. Finally, the turbidity pro- 
 duced by the carbon dioxide evolved is compared with that produced in the 
 subacetate of lead solution by a known and comparable quantity of carbon 
 dioxide in a modified Mill's colorimeter. For details we refer to the original 
 paper. 
 
 KjeldahVs Method.' — This has been recently used for the determination of 
 the total combined nitrogen, except nitrates, in natural waters (Drown and 
 Martin, ' Chemical News,' 1889, vol. 59, p. 272). It is employed as 
 follows : 500 c.c. of the water are placed in a round-bottomed flask of about 
 30 oz. or 900 c.c. capacity attached to a condenser, and 200 c.c. are dis- 
 tilled and nesslerised for ammonia, as in the albuminoid ammonia process. 
 To the remaining 300 c.c. of water in the flask, after coohng, 10 c.c. of 
 nitrogen-free sulphuric acid are added, and the whole gently agitated so that 
 the acid may mix with the water. The flask is then placed at an inclination 
 on wire gauze on an appropriate support, and the hquid is boiled down till 
 the oily residue is colourless or pale yellow in tint. The flask is removed 
 from the flame, and a very little powdered permanganate of potassium is 
 added till the green colour of the Hquid shows that an excess of permanganate 
 has been added. Should the Uquid become purple and not green, the water 
 has not been all driven off. After cooling, 200 c.c. of ammonia-free distilled 
 water are added, the neck of the flask being washed free from acid by the 
 process, and then 100 c.c. of a solution prepared by dissolving 200 grammes 
 of good caustic soda in 1250 c.c. of distilled water, adding 2 grammes of per- 
 manganate of potassium to oxidise organic matter, and boihng down to a 
 litre. After the addition of this solution, the flask is immediately connected 
 with the condenser, shaken, and the distillation slowly commenced till 
 50 c.c. have distilled over and been condensed in very dilute hydrochloric 
 acid, after which the liquid in the flask may be vigoroiTsly boiled until 
 150 c.c. or 175 c.c. have been altogether collected. The distillate is made 
 up to 250 c.c. with ammonia-free water, and 50 c.c. of this are nesslerised. 
 It may be necessary to dilute still further before nesslerising. It is not found 
 that with the extreme dilution of natural waters the determination of organic 
 nitrogen is vitiated by the presence of nitrates and nitrites. 
 
 The Albuminoid Ammonia Process. — This process was devised by Mr. 
 Wanklyn and the late Mr. E. T. Chapman. It is the process most generally 
 used in the analysis of water for sanitary purposes ; and though it does not 
 determine the total amount of organic matter or nitrogenous organic impurity 
 present, it affords perhaps as accurate a comparative estimate of the organic 
 contamination of a water as any other chemical method. Eeagents 
 required : — 
 
286 HYGIENE 
 
 1. Nessler's reagent, prepared by dissolving 35 grammes of ioclide of 
 potassium and 13 grammes of mercmic chloride in 800 c.c. of boiling 
 distilled water, and then adding a cold saturated solution of mercu.ric 
 chloride imtil a permanent red precipitate begins to form ; l(iO grammes of 
 sohd caustic potash are added, and, Avhen dissolved, the whole is made up 
 ■with distilled water to the volume of a litre. A httle more solution of 
 mercuric chloride is then added to make the solution more sensitive, and it 
 is then allowed to settle. It should have, when clear, a slight yellow 
 colour ; if not, it is less sensitive, and requires a further addition of mercuric 
 chloride. The reagent is best kept in a large carefully-stoppered bottle, and 
 a httle of the solution is transferred from time to time to a small reagent 
 bottle as required. 
 
 2. Ammonia. — 3*15 grammes of chloride of ammonium are dissolved in a 
 litre of distilled water, and from this a weaker solution is prepared by making 
 up 10 c.c. of the solution to a litre with distilled Avater. Each 1 c.c. of the 
 weaker solution = t-o o^^^ milligramme NHg. 
 
 8. Alkalised Permanganate of Potassium. — Eight grammes of perman- 
 ganate of potassium are dissolved in a htre of water ; 200 grammes of stick 
 potash are added, and the whole is boiled briskly for half an hour or 
 more, tiU about one-fom*th of the solution is evaporated. The solution is 
 then made up to a litre with ammonia-free distilled water. Or the above 
 quantities of permanganate and caustic potash are dissolved in 1250 c.c. of 
 distilled water and the solution boiled down rapidly to 1000 c.c. 
 
 4. Ammonia-free Water. — This is prepared by distilhng good tap-water, 
 ■\Aith the addition of a httle freshly ignited sodium carbonate, taking care to 
 reject the first portions of the distillate, and not to distil too low. Or, as 
 recommended by the Society of Public Analysts, tlie purest distilled water 
 obtainable to which one jpart per 1000 of freshly ignited pure sodium car- 
 bonate has been added is boiled briskly until at least one-fourth has been 
 evaporated ; 100 c.c. of this water must, when tested, not contain so much 
 as -5~J-7j-th milligramme of NHg. 
 
 The apparatus required are, a stoppered retort holding about 1200 c.c, 
 fitted to a Liebig's condenser, with Bunsen's burner and retort-clamp, several 
 glass cyhnders marked at 50 c.c, a half-litre measuring flask, a 50 c.c. glass 
 measm-e, a funnel by which to fill the retort, a pipette to dehver 2 c.c, and 
 a graduated stoppered burette or pipette graduated to ^^o^h or -^th cubic 
 centimetre. The appropriate apparatus can be readily purchased of the 
 instrument makers in a state of readiness for use. A sink and abundant 
 supply of condensing water is indispensable. In well-appointed laboratories 
 the retort is kept mounted and ready for use. 
 
 The operation is conducted as follows : After having cleaned the retort by 
 rinsing it with strong sulphuric acid and then with water, it is mounted, and 
 good tap-water is distilled from it tiU the distillate comes over free from 
 ammonia ; and the retort is then emptied by means of a syphon. Half a 
 litre of the Avater to be analysed is then introduced through the funnel, 
 and if the water be not alkaline about half a gramme of freshly ignited 
 sodium carbonate is added, and a few pieces of freshly ignited pumice. 
 The retort is then heated and kept boilmg by the naked flame of a 
 Bunsen's burner. Successive 50 ccs. of distiUate are collected in the 
 cyhnders and ' nesslerised ' in the manner to be presently described. The 
 distillation is stopped when no more ammonia comes over. (Mr. Wanklyn 
 prefers to nesslerise the first 50 c.c, Avhich he states always contains three- 
 fourths of the whole ammonia, and then he distils a further 150 c.c, which 
 he rejects.) The ammonia thus obtained is termed ' sahne ammonia,' or by 
 
WATER 287 
 
 some ' free ammonia.' It represents the ready-formed ammonia, or its salts, 
 present in the water. 50 c.c. of the alkahsed permanganate of potassimn 
 are now introduced into the retort and the distillation recommenced. A bold 
 application of the gas flame to the naked retort is the best means of avoiding 
 the bumping which often occurs, especially when the water is a bad one. 
 Successive 50 c.cs. of distillate are collected in the cylinders and nesslerised, 
 and the distillation is continued till no more ammonia is evolved. In the 
 case of peaty waters an addition of ammonia-free water, and repeated distilla- 
 tion, may be necessary. When the distillation is completed it is best to leave 
 the retort unemptied, and when a fresh analysis has to be made the retort is 
 washed out in situ with tap-water and some of this distilled in the apparatus, 
 which is thus most readily rendered free from ammonia. The ammonia 
 liberated by the alkalised permanganate is termed ' organic ammonia ' or 
 * albuminoid ammonia.' It is the measure of the nitrogenous organic matter 
 present in the water, which is broken up and made to yield ammonia by the 
 alkalised permanganate. To nesslerise ammonia — saline or organic— to a 
 50 c.c. cylinder of distillate, 2 c.c. of Nessler's solution are added by means 
 of the pipette, and the mixture stirred. The depth of yellow-brown colour is 
 judged of by the eye, and, the requisite amount of ammonia being guessed, a 
 like quantity is run into another cylinder from the burette containing the 
 standard ammonia solution, and the solution diluted till it measures 50 
 CO., when 2 c.c. of Nessler's solution is added. The two cyhnders are 
 compared, and if the depth of tint is not the same, another cyhnder is pre- 
 pared containing less or more ammonia, as the case may be, till a standard 
 cylinder and the cylinder of distillate agree in tint. With a practised operator 
 the requisite tint is speedily obtained. Should the Nessler's solution give 
 a precipitate with the distillate, it is requisite to repeat the distillation, 
 and take smaller quantities of the distillate — 10 c.c. or 20 c.c, and dilute to 
 50 c.c. before nesslerising. Each 1 c.c. of standard ammonia solution con- 
 taining rhs^^ milligramme of NH3 will, of course, represent that quantity 
 in the 500 c.c. of water taken, or '02 part per million, or 0-0014 grain 
 per gallon. Thus, e.g. — 500 c.c. of water yielded successive distillates of 
 50 CO., which, when nesslerised, gave a tint equal to 1*5 c.c, 0-5 c.c, and 0*0 
 ■c.c of standard ammonia, and of albuminoid ammonia equal to 3 c.c, 2 c.c, 
 1 c.c, 0-5 c.c, and 0-0 c.c. standard ammonia solution. Then we have : — 
 
 Saline, NH^. — 1-5 -|--5 = 2 x 2=4 — 100th milhgramme per litre NH3, 
 or '04 part per million ; and -04 x '07 = '0028 grain per gallon. 
 
 Albuminoid, NH^.—S + 2 + 1 + 0-5 = 6-5 x 2 = 13 - 100th milh- 
 gramme per litre, or 0-13 per million ; and -13 x "07 = "0091 grain per gallon. 
 
 The advantages of the albuminoid ammonia process are, the rapidity with 
 which it is carried out, the simplicity of the apparatus required, and, what its 
 defenders assert, the greater certainty of its results when compared with 
 those obtained by any other process. It is not j)retended that the nitrogen 
 yielded in the form of albuminoid ammonia is all that contained in the 
 water operated on ; Mr. Wanklyn, indeed, asserts that the nitrogen obtained 
 is a definite fraction of that contained in many organic bodies, but even this 
 can scarcely be asserted of the unknown forms of nitrogenous organic matter 
 contained in waters. Its detractors aver, on the other hand, that the 
 albuminoid ammonia yielded is uncertain in its amount, and is no definite 
 guide to the organic nitrogen present in a water ; and that it is misleading. 
 Probably the truth is, that neither is the albuminoid ammonia a certain 
 index to the quality of a water, nor an altogether unreliable one. Generally, 
 it is fairly reliable, and no more can be asserted with assuredness of any 
 other process for determining the pollution of a water. 
 
288 HYGIENE 
 
 The behaviour of peaty waters when submitted to the albuminoid 
 ammonia process is pecuhar. They yield a relatively large quantity of 
 albuminoid ammonia, which is evolved slowly and somewhat persistently. 
 This peculiarity is so well known that it can scarcely mislead any skilled 
 analyst accustomed to use the process. Badly polluted waters, on the other 
 hand, generally yielded their high proportion of albuminoid ammonia 
 promptly and sharply. 
 
 The Permanganate Process for Determination of Oxygen required to 
 Oxidise Organic Matter. — This process is carried out in various ways. The 
 following is the method as advised by Dr. Tidy, who has specially investigated 
 the process (' Jour, of Chem. Soc. Trans.,' vol. xxxv., 1879, p. 46). 
 
 The following solutions are required (for the quantities given by Dr. 
 Tidy in grains and septems are substituted grammes and cubic centimetres) : 
 
 1. Dilute sulphuric acid : 1 part of pure sulphuric acid with 3 parts of 
 distilled water. 
 
 2. Solution of permanganate of potassium : 0'28G gramme per litre ; 
 10 c.c. = '714 milligramme of available oxygen. 
 
 3. Solution of iodide of potassium, free from iodate : 1 part in 10 parts 
 of water. 
 
 4. Thiosulphate of sodium (hyposulphite) : 0*77 gramme in a litre of 
 distilled water. 
 
 5. Starch solution, carefully prepared : about 1^ gramme in 100 c.c. of 
 water. 
 
 Two similar pint-glass flasks are very carefully cleaned, and in each is 
 placed 250 c.c. of the water to be analysed, 10 c.c. of dilute sulphuric acid, 
 and 10 c.c. of the permanganate solution, noting the time of adding the per- 
 manganate. If before the end of three hours the colour of the permanganate 
 has disappeared, a second or even a third addition of 10 c.c. of perman- 
 ganate must be made, so as to maintain the red colour of the liquid in the 
 flask. At the same time as the above experiments are made, two similar 
 quantities of distilled water are treated in a precisely similar manner. At 
 the end of one hour, and at the end of three hours, one of each of the flasks 
 containing distilled water and the water under examination respectively 
 is treated with two drops of the iodide of potassium solution, and then 
 titrated with the thiosulphate solution. The other two flasks — one of dis- 
 tilled water, and the other of the sample water — are allowed to remain till 
 the reaction with the permanganate has gone on for three hours, and 
 then two drops of the iodide solution are added, and the titration with thio- 
 sulphate (' hypo ') completed. 
 
 The value of the thiosulphate solution must be very frequently deter- 
 mined, as the salt decomposes in solution. A blank experiment with 
 distilled water is made by putting 250 c.c. of distilled water iato a flask, with 
 10 c.c. of dilute sulphuric acid and 10 c.c. of the permanganate solution. 
 Two drops of the iodide of potassium solution are added, and then the 
 thiosulphate solution is run in from a burette until the yellow colour of free 
 iodine has nearly disappeared. A few drops of the starch solution are now 
 added, and the addition of thiosulphate continued till the blue colour just 
 disappears ; and the amount of the thiosulphate used is noted. In operating 
 upon the water under analysis, the same process of titrating with thiosulphate 
 is followed after one and three hours' action of the permanganate. 
 
 The calculation of the results is as follows : 
 
 Let X = no. of c.cs. of thiosulphate used hi the distilled water. 
 
 Y = no. of c.cs. of thiosulphate used in the water under examination. 
 
 Then if 10 c.c. of the permanganate solution were used, 
 
WATER 289 
 
 X — Y X 0-2 _ gj,g^-j^g Qf oxygen required to oxidise organic matter in one 
 
 A. 
 gallon of the water. 
 
 If 20 c.c. of permanganate were used, 2X must be substituted for X in 
 the above equation ; if 30 c.c. substitute 3X, and so on, in making the 
 calculation. 
 
 The method recommended by the Society of Public Analysts ('The 
 Analyst,' vol. vi., 1881, p. 126) of carrying out the operation is somewhat 
 different, and is performed thus : — ^ 
 
 Two separate determinations are made— the amount oi oxygen absorbed 
 during fifteen minutes, and that absorbed during four hours ; both being 
 made at a temperature of 80° F. (26° -7 C). These are made in 12 oz. 
 stoppered bottles. Put 250 c.c. of the water into each of two of the bottles ; 
 stopper and immerse in a water-bath until the temperature reaches SO'-' F. Now 
 add to the water 10 c.c. of dilute sulphuric acid (1-3), and 10 c.c. of a solution 
 of permanganate of potassium (0-395 gramme per htre). Fifteen minutes after 
 the addition of the permanganate, one of the bottles is removed from the 
 bath, 2 or 3 drops of a solution of iodide of potassium. (1 in 10) added, and 
 the liberated iodine titrated by means of a solution of thiosulphate (1 gramme 
 in 1 litre of water), the end of the reaction being determined by a solution of 
 starch (1 in 600), as in Dr. Tidy's process. At the end of four hours the 
 other bottle of water is titrated in the same manner. But if before the 
 expiration of four hours the pink colour of the solution should grow very 
 pale, a further addition of a measured quantity of the permanganate solution 
 must be made, so as to keep up a decided pink or red colour. The thio- 
 sulphate solution must be titrated with 250 c.c. of good distilled water from 
 time to time, into which is placed 10 c.c. of the permanganate solution, and 
 then a few drops of the iodide of potassium solution. The quantity used 
 will represent the quantity of thiosulphate solution equivalent to 0*00395 
 gramme permanganate, or -001 of available oxygen. The calculation is 
 this. 
 
 Let a = number of c.cs. thiosulphate required in blank experiment to = 10 
 c.c. permanganate. 
 b = number of c c. thiosulphate used in titration of the watei. 
 
 ~ 7, y .OQ 
 
 Then - — - - = grains of oxygen per gallon required to oxidise organic 
 
 a 
 matter. 
 
 Recently Mr. Blair has proposed a novel method of estimating the amount 
 of organic matter in drinking water ; but his process has not as yet been 
 much adopted (' The Organic Analysis of Potable Waters,' by J. A. Blair, 
 M.B., 1890). 
 
 Lead and Copper. — An examination for these injurious metals may be 
 readily and expeditiously made ; and if one of these metals only be present, 
 as is usually the case, by calorimetric methods. 
 
 100 c.c. of the water is placed in a nesslerising cylinder, and a drop of 
 solution of sulphide of ammonium is stirred in, when a dark colouration or 
 precipitate will indicate the presence of iron, lead, or copper. If it be due 
 to iron, the colour will be discharged by the subsequent addition of a drop 
 or two of strong hydrochloric acid, which will not, however, discharge the 
 colour if lead or copper be present. 
 
 Copper may be distinguished from lead by placing 100 c.c. of the water 
 
 in a similar cylinder, acidifying with a drop or two of acetic acid and a drop 
 
 of a solution of ferrocyanide of potassium, when, if copper be present, the 
 
 liquid will acquire a faint red tint. By comparing the depth of tint with 
 
 VOL. I. u 
 
-290 HYGIENE 
 
 distilled water similarly treated, and to -wliich a standard solution of sulphate 
 of copper has been added, the quantity of copper may be estimated. A 
 convenient solution for this purpose is an aqueous solution of crystallised 
 sulphate of copper, 5-6 grammes to the Utre : 1 c.c. of this solution contains 
 1-43 milhgramme of copper ; and hence, working with 100 c.c. of water, 
 each O'l c.c. copper solution added to the water corresponds to 0*1 grain 
 copper per gallon. 
 
 The presence of lead may be confirmed by placing some of the water in a 
 tall glass cylinder and sprinkling on its surface a few fragments of powdered 
 potassium bichromate, when, if lead be present, a cloud of yellow lead chro- 
 mate will fall in streaks to the bottom of the cylinder. The quantity of 
 lead may be determined by treating 100 c.c. of the water in a cylinder as 
 in the titration of copper, adding a drop of hydrochloric acid and 2 c.c. of 
 good sulphuretted hydrogen water. The depth of brown or black colour 
 produced is then compared with that produced by the same quantity of the 
 same reagents, added to 100 c.c. distilled water in a similar cylinder. The 
 standard lead solution employed should contain 2-62 grammes crystallised 
 lead acetate, and a few drops of acetic acid in a litre of distilled water. 
 Each 1 c.c. contains 1"43 milhgramme of lead ; and when 100 c.c. of water 
 are operated on, each O'l c.c. corresponds to 0*1 grain of lead per gallon. 
 
 Hardness. — For hygienic purposes it is always desirable to estimate the 
 hardness of a water, i.e. its soap-destroying capacity ; and although it is 
 undoubted that the hardness of a water, as determined by experiment, is not 
 always a safe guide to the quantity of lime and magnesia salts present — ■ 
 these being the chief soap-destroying constituents of ordinary waters — an 
 estimate of the so-called hardness of a water by Clark's soap test ought 
 never to be omitted. 
 
 A hard water is one which requires much soap in order to yield a 
 permanent lather, and is usually rich in lime and magnesia salts ; a soft 
 water is, conversely, one usually poor in the salts of the alkaline earths, and 
 readily yields a lather with a small quantity of soap. Again, the hardness 
 of a water is distinguished as total hardness or the hardness of the natural 
 water ; ^jer7?za«eTOi hardness, or that which remains after boiling, and 
 chiefly due to the presence of those salts of calcium and magnesium — 
 such as the sulphates, chlorides, and nitrates — which are not thrown down 
 on boiling ; and temporary hardness, obtained by subtracting the perma- 
 nent from the total hardness, and attributable to the carbonates of calcium 
 and magnesium present. These definitions are, nevertheless, not strictly 
 accurate ; for hardness may be due to the presence of ferruginous salts, and 
 permanent hardness may be due, in the absence of temporary hardness, to 
 the existence of free mineral or vegetable acids in the water ; for acids destroy 
 soap equally with lime compounds. It is hence best to consider hardness 
 strictly and solely as soap-destroying power, to whatever cause this be assign- 
 able. 
 
 Dr. Clark, of Aberdeen, first proposed a method of determining hardness 
 experimentally, in substitution of the method of computing the hardness 
 from the amounts of lime and magnesia found by analysis, and his method, 
 or a modification of it, is now universally adopted (' On the Examination 
 of Water for Towns for its Hardness,' by G. T. Clark, 1847). 
 
 "When a solution of soap — best in dilute alcohol — is added to distilled 
 water, and the whole is agitated, a faint opalescence appears, and at first no 
 lather forms ; but the addition of a very small further quantity of the soap 
 solution results in the formation of a permanent lather on agitation. But if 
 an ordinary hard water be treated in the same manner, the opalescence 
 
WATEB 291 
 
 iDecomcs a marked turbidity or distinct precipitate, and much more soap 
 solution has to be added to procure a permanent lather, which appearance 
 indicates the presence of a slight excess of soap — conferring viscosity to the 
 liquid — beyond the amount necessary to decompose the lime and magnesia 
 salts, and other soap-destroying compounds present ; nor does the test 
 directly distinguish between one soap-destroying compound and another. 
 
 It is customary to express the hardness in ' degrees ; ' and each degree 
 of Clark's scale indicates one grain of calcium carbonate per gallon of water, 
 or the equivalent of one grain of chalk in soap -destroying power. Thus, 
 e.g., one degree of hardness may be due to one grain of calcium carbonate, 
 I'll grain of calcium chloride, or 1*36 grain of calcium sulphate, &c., 
 each of these calcium compounds containing in the above quantities re- 
 spectively 0*4 grain of calcium. In France each degree of hardness indi- 
 cates one part by weight of calcium carbonate, or its equivalent, per 
 100,000 parts of water; whilst in Germany a degree of hardness indicates 
 one part of lime (CaO), or its equivalent, per 100,000 parts of water. Hence 
 ihe various values of degrees of hardness are : — English 1° = German 0°"8 = 
 French 1°*4 nearly. Many analysts who give the results of their analyses in 
 parts per 100,000 use the French scale of hardness. 
 
 The requisites for the determination of hardness : — 
 
 1. A standard solution of calcium sulphate is obtained by grinding in 
 a mortar 0-1965 gramme of crystallised selenite, CaS04 2H2O, with a 
 sufficiency of distilled water to dissolve it, and making up to the volume of a 
 litre. Or 0"2985 gramme barium nitrate may be dissolved in distilled 
 water and made up to a litre. Either of these solutions contains the 
 equivalent, in calcium or barium salts, of 8 grains calcium carbonate per 
 gallon. 
 
 2. A stoppered narrow-mouthed bottle holding 200 c.c, or, as preferred 
 by some, one holding 100 c.c. 
 
 3. A burette on stand divided into cubic centimetres and tenths of a 
 cubic centimetre. 
 
 4. The standard soap solution. A potash soap is best for the desired 
 purpose, prepared thus : 15 parts of the lead plaster of the British Pharma- 
 copoeia (lead oleate) are warmed on a water-bath with 4 parts of potassium 
 carbonate and rubbed in a mortar to a uniform consistence ; then digested 
 with ordinary rectified methylated spirit, allowed to deposit, and diluted with 
 ^ater in the proportion of three volumes of water to every five volumes of 
 rectified spirit employed ; in other words, the alcohol is reduced to about 
 proof strength, and any subsequent dilution is made with spirit of proof 
 strength. The solution is then filtered. 
 
 Very commonly the soap solution is prepared by dissolving ordinary good 
 undried Castile soap in the proportion of 14 grammes to the litre of a mixture 
 of methylated rectified spirit and distilled water in equal volumes ; and there 
 is no objection to this when no minute degree of accuracy is demanded. In 
 any case it is well to prepare a stock bottle of strong soap solution, and to 
 dilute some of the clear liquid from time to time with alcohol of proof strength 
 and standardise it in the following manner occasionally, as soap solutions are 
 apt to deposit in winter, or when long kept, and thus to lose strength. 
 
 The standardising of the soap solution is effected by taking 50 c.c. of 
 the standard calcium (or barium) solution, placing it in the bottle and 
 running in the soap solution from a burette till a thick fine uniform white 
 froth is produced on vigorously shaking the bottle, and should remain for five 
 minutes when the bottle is placed on its side. If less than 9 c.c. of the soap 
 solution are required, the requisite quantity of dilute alcohol is added to reduce 
 
 u2 
 
292 HYGIENE 
 
 it to the required strength, i.e. so that 9 c.c. of the soap is exactly sufl6cienfc 
 to give a permanent lather -with 50 c.c. of the standard calcium solution 
 of 8*0° of hardness. For example, 50 c.c. of the standard calcium gave a 
 lather persisting for five minutes with G c.c. of a soap solution ; then each 
 litre of this soap solution must be diluted till it measures |?ths of a litre, or 
 1500 c.c. The solution after this adjustment must be again titrated, and if 
 50 c.c. of the standard water requires more or less than the requisite 9 c.c, 
 a little more dilute alcohol, or a little strong solution of soap must be added 
 till the requisite strength is obtained. 
 
 The estimation of hardness is effected by pipetting 50 c.c. of the water 
 into the stoppered bottle, and running in the standard soap solution fi'om 
 the burette, at first rapidly, and then very slowly, with repeated shaking till 
 a fine uniform creamy lather is obtained, which persists for five minutes, 
 ■when the bottle is allowed to rest on its side. An approximation to the 
 quantity of soap required being thus obtained, the titration is repeated with 
 greater care, adding the soap at first in quantities of 1 c.c. at a time, and 
 towards the end of the reaction drop by drop till the desired lather is 
 obtained. The carbonic acid liberated on agitation should from time to time 
 be removed by blowing air into the bottle by a pair of bellows. 
 
 Should more than 9 c.c. of soap be required, it is always well — and m 
 the case of magnesian waters indispensable — to dilute the water under 
 examination with its own bulk, twice its own bulk, &c., of distilled water till 
 not more than 9 c.c. is requirod by 50 c.c. of the diluted water. 
 
 The proportion between the soap used and the actual degree of hardness 
 of a water is not constant, and, according to the accurate observations of 
 Faiszt and Knausz, the degree of hardness corresponding to each 1 c.c. of 
 soap solution used mcreases constantly with the amount of soap used. 
 According to Wanklyn, distilled water requires 1 c.c. of soap solution to 
 produce a lather ; and he deducts 1 c.c. from the number of cubic centi- 
 metres of soap solution, and the remainder gives the hardness in degrees. 
 The later experiments of Clark, confirmed by those of Faiszt and Knausz, 
 give 0*5 c.c. approximately, as the amount of soap required by 50 c.c. of 
 distilled water. The follo"ttang table expresses Clark's latest results, and is 
 sufficiently accurate : 
 
 c.c. of soap Degrees of 
 
 solution used. hardness (Clark). 
 
 0-45 0° 
 
 1-45 1° 
 
 2-70 2° 
 
 3-85 3° 
 
 4-95 4° 
 
 6-00 5° 
 
 After which deduct 1 c.c. from the number of c.cs. used, and the re- 
 mainder is the hardness in degrees. 
 
 In this way, the total hardness having been determined, 250 c.c. of the 
 water is kept boiling over a naked flame for half an hour or an hour, the 
 evaporated water being nearly replaced from time to time by distilled water. 
 The water is quickly filtered into a dry 250 c.c. flask, the filter quickly washed 
 with boiling distilled water, and the whole adjusted to 250 c.cs. when cold. 
 60 c.c. of the boiled water is then titrated anew with soap solution, and in 
 this way the permanent hardness is obtained. The difference between total 
 and permanent gives the teviporary hardness. 
 
 It must not be forgotten that if the water be diluted the necessary cor- 
 rection for dilution must be made. 
 
WATEB 293 
 
 The following are useful data as to hardness : 
 
 1 degree (1°) Clark's scale = 1-4 degree (l°-4) on the centesimal scale 
 
 (parts per 100,000). 
 1 degree (1°) Clark's scale = 0-8 degree (0°-8) on the German scale. 
 1 grain CaCOg = I'll gr. CaClg = 1-38 gr. CaS04 = 0-56 gr. CaO 
 
 = 0-84 gr. Mg CO3 = 0-4 gr. Mg in soap-destroying power. 
 1 grain per gallon CaCOg = 1-43 milligramme per litre. 
 Distilled water requires approximately as much soap to yield a lather as 
 0-7 grain per gallon CaCOg, or 1 part CaCOg in 100,000 parts of water. 
 This is the excess of soap beyond that required to precipitate the calcareous 
 salts of the water required to produce a lather on agitation of the water with 
 the soap. 
 
 Iron. — It is not often necessary for sanitary purposes to determine the 
 quantity of iron present in a drinking water. Generally it is sufficient to 
 ascertain that a water is not chalybeate by the sense of taste, and by ascer- 
 taining that it does not assume a purple or inky hue on the addition of 
 a few drops of tincture of galls to half a pint of the sample. But when it 
 is desired to ascertain the amount of iron present, this can be most con- 
 veniently done by making use of a process devised by Carnelley (' Mem. Man- 
 chester Lit. and Phil. Soc' 1874-5, p. 346). 1 c.c. of dilute sulphuric acid is 
 added to a measured volume of the water, to which a dilute solution of per- 
 manganate of potassium is added until a permanent pink tint is imparted to 
 the liquid ; and the volume is then made up to a litre by the addition of 
 distilled water. The quantity of the water under examination requisite to 
 make up the litre is judged of approximately by previous quahtative tests for 
 iron. 50 or 100 c.c. of the Htre of hquid thus obtained are placed in a 
 cylinder, 5 c.c. of dilute nitric acid are added, and then a couple of drops 
 of a solution of potassium ferrocyanide. The depth of blue colour (Prussian 
 blue) produced is. then compared with that produced under like conditions 
 in a similar cylinder by a standard solution of iron when mixed with the 
 same quantities of the dilute nitric acid and ferrocyanide solutions. The 
 iron (ferric salt) solution is prepared by dissolving 0-7 gramme of pure 
 crystallised ferrous ammonium sulphate in water, acidulating with 1 c.c. of 
 dilute sulphuric acid, oxidising by the addition of a solution of potassium 
 permanganate till a barely visible permanent rose tint is produced, and 
 diluting with distilled water to a litre. 1 c.c. of this solution = 0-1 milli- 
 gramme of iron. 
 
 For example : 600 c.c. of a water was oxidised with permanganate and 
 made up to 1 litre. Of this 50 c.c. gave as much blue colour with ferro- 
 cyanide as 0*5 c.c. of the standard iron solution in 50 c.c. of distilled water. 
 Then O'S x O'l x 20 = 1 milligramme is the quantity of iron in 500 c.c. of 
 the water under examination ; and 1 x '2 = 0-2 is the iron per 100,000 
 parts ; and 1 x 0-14 = 0-14 is the grains of iron per gallon. 
 
 In operating upon chalybeate waters greater dilution is necessary ; but 
 the results are sufficiently accurate for all ordinary purposes. 
 
 Silica. — A litre of the water is acidified with hydrochloric acid, and eva- 
 porated to dryness in a platinum dish, the residue digested with strong 
 hydrochloric acid in a warm place, water added to the separated silica, which 
 is filtered off, well washed, dried, ignited, and weighed. 
 
 Manganese. — This metal is rarely present in waters in apj)reciable quan- 
 tity, though its presence was formerly not at all uncommon in the acid waters 
 contaminated by the discharge from bleach-works. Manganese may be de- 
 tected by concentrating the water, precipitating with ammonia and a few drops 
 
294 HYGIENE 
 
 of a solution of peroxide of hydrogen, and collecting the precipitate of ferric^ 
 aluminic, and manganic oxides on a filter. The washed and dried precipitate 
 ■with the filter is fused with caustic soda and a fragment of potassium 
 nitrate in a silver dish, when the manganese is converted into a manga- 
 nate. On treating the residue with water faintly acidulated with sulphuric 
 acid, a rose-red or purple solution of permanganic acid is obtained, which 
 when examined by the spectroscope exhibits fine dark characteristic absorp- 
 tion bands, and is decolourised by the addition of a drop or two of ammonium 
 oxalate solution. 
 
 A quantitative determination of the manganese is seldom or never re- 
 quired in the hygienic analysis of a water. 
 
 Chromium. — Compounds of chromium (chromic salts and chromates) may 
 be detected by evaporating a litre or two of the water to dryness, and fusing 
 the dry residue wath sodium carbonate and a fragment of potassium nitrate 
 in a silver dish. The residue is extracted with water, filtered, and the. 
 filtrate neutralised with nitric acid and evaporated twice to dryness in a por- 
 celain dish, in order to get rid of free nitric acid. The neutral residue dis- 
 solved in water will, if chromium be present, yield a yellow precipitate 
 insoluble in acetic acid when solution of lead acetate is added, and will also 
 yield a red precipitate of silver chromate if excess of silver nitrate solution 
 be added. 
 
 A water containing chromium compounds should be unhesitatingly re- 
 jected as a drinking-water, these compounds being highly irritant and toxic, 
 even in minute quantities. 
 
 Dissolved Oxygen. — Dr. Thresh (' Proc. Chem. Soc' 1890, p. 1) has devised 
 the simplest method of estimating the dissolved oxygen gas in water. 
 
 The solutions required for the process are : (1) a solution containing 
 0*5 gramme sodium nitrite and 20 grammes potassium iodide in 100 c.c, 
 distilled water ; (2) an aqueous solution containing 7*75 grammes sodium 
 thiosulphate (hyposulphite) to the litre. 1 c.c. of this corresponds to 0*25 
 milligramme of oxygen ; (3) clear starch solution ; (4) dilute sulphuric 
 acid (1 : 3). The apparatus used consists of a wide-mouthed bottle of 
 500 c.c. capacity, provided with a caoutchouc stopper through which four 
 holes are bored. Through one passes the neck of a cylindrical ' separator ' 
 funnel of known capacity, and through the second a tube drawn out to a fine 
 point, which is connected by a short length of flexible tubing with the 
 thiosulphate burette, while inlet and exit tubes for coal-gas are passed 
 through the third and fourth holes, the exit tube having attached to it a 
 sufficient length of caoutchouc tubing to permit of connection being esta- 
 bhshed between the bottle and the separator when the stopper of the latter 
 is withdrawn. 
 
 The separator is filled with the water to be examined, and 1 c.c. of the 
 nitrite-iodide, and 1 c.c. of the acid solution are added. If the pipette be 
 held vertically, with its end just below the surface of the water, the solutions 
 flow in a sharply defined column to the lower part of the separator ; so that 
 a very small quantity, if any, is lost in the water which overflows when the 
 stopper is inserted. The apparatus is inverted several times, and then a 
 quick current of coal-gas is passed through the bottle, the escaping gas being, 
 ignited. After fifteen minutes the flame is extinguished ; a cork is attached 
 in place of the jet, and is inserted in place of the stopper of the separator ; 
 and the w^ater is then allowed to flow into the bottle. The exit tube having 
 been disconnected from the funnel and the gas lighted, thiosulphate is run 
 in imtil the colour of the iodine is nearly destroyed ; about 1 c.c. of starch 
 solution is then added from the separator, and the titration is completed.. 
 
WATER 295 
 
 The effect of the nitrite, dilute acid, and starch solutions is determined by 
 removing the separator and adding 5 c.c. of each in succession and then 
 titrating. An allowance is made for the oxygen dissolved in it, on the 
 assumption that as much oxygen is dissolved in it as in distilled water at the 
 same temperature. At the temperature of 59° F. (15" G.) distilled water 
 dissolves 7 milligrammes of oxygen per litre. 
 
 DETEEMINATION OP THE ACTION OF A WATER UPON LEAD 
 
 This important determination, where the adoption of a new water-supply 
 is under consideration, is one beset with difficulties ; and the results ob- 
 tained are, as a rule, by no means satisfactory or conclusive. 
 
 A method commonly adopted is to immerse fresh-scraped clean plates of 
 lead, 6x2 inches in size, in a known volume, say 500 c.c. (or, better, 1 pint 
 = 568 c.c.) of the water in a loosely stoppered bottle capable of holding 
 double this quantity of liquid. After twenty-four hours the strips of lead are 
 removed and any corrosion or deposit is noted. After filtration the water is 
 examined for the lead in the usual manner (see p. 256). 
 
 A better and more satisfactory plan is to take a 36-inch length of fresh 
 well-cleaned lead pipe, of ^ inch bore, closed by means of a cork provided 
 with a pinch-cock below, and by a cork above. The tube is rinsed with the 
 water and then filled with it, corked, and placed in an early horizontal posi- 
 tion, the pinch-cock being at the lowest end of the tube. After a definite 
 period, say 12, 18, or 24 hours, the water is run out of the tube, and replaced 
 by a fresh quantity, which is again withdrawn at the end of any desired period. 
 The successive quantities of water are measured, and the lead present deter- 
 mined as before. In this way the action of the water upon lead (either fresh 
 pipe or after some use) may be determined. The volume of water held 
 by a pipe of ^ inch bore, and 36 inches in length, is one-fifth of a pint ap- 
 proximately, or 116 CO. 
 
 Standard Solutions, fob, Analysis 
 
 The following are the strengths of the standard solutions recommended. 
 
 1. Nitrate of Silver. — 4-79 grammes recrystallised silver nitrate per htre 
 of water. 1 c.c. precipitates 1 milligramme of chlorine. 
 
 2. Indigo Solution of such strength that 1 c.c.= ^Lth milligramme N2O5 
 =1 c.c. of a solution of 0*187 gramme KNO3 per litre of water. 
 
 8. Plienol-sulphuric Acid. — 2 volumes melted absolute phenol, 5 vol. 
 pure oil of vitriol, about 5 vol. distilled water, and 1\ vol. strong solution of 
 HCl (see p. 279). 
 
 Potassium nitrate for use with the above, 0*7215 gramme per litre of 
 water. 
 
 4. Metaphenylene-diamine Hydro -chlorate. — 1 gramme in 200 c.c. dis- 
 tilled water, acidulated with sulphuric acid. 
 
 Silver nitrite for use with this, 0-405 gramme AgNOa precipitated with 
 KCl and made np to a litre. This is dilated 10 times for use, when each 
 1 c.c. = xsT)^^ milligramme N^Og. 
 
 5. Nessler's Solution. — 35 grammes potassium iodide, 13 grammes 
 mercuric chloride, and 160 grammes caustic potash to a litre. If not sensi- 
 tive, add more of a solution of mercuric chloride. 
 
 6. Chloride of Ammonium. — 3-15 grammes ammonium chloride to a 
 litre of water. Each 1 c.c. = 1 milligramme NH3. 
 
296 HYGIENE 
 
 A solution prepared by diluting the above 100 times ; each 1 c.c. rio^^ 
 milligramme KHy. 
 
 7. Alkalised Potassium Permanganate. — 8 grammes potassium perman- 
 ganate and 200 grammes stick caustic potash in 1250 c.c. distilled water. 
 Boil down to 1 htre. 
 
 8. Potassium Permanganate for oxygen process, 0-28G gramme per litre 
 of water. 
 
 9. Sodium Hyposulphite. — 0*77 gramme sodium thiosulphate (' hypo ') 
 in a litre of water. 
 
 10. Lead Acetate. — 2*62 grammes in a litre of water. 
 
 11. Copper Sulphate. — 5"6 grammes to a litre of water. 
 
 12. Calcium Sulphate (for hardness). — 0"1905 gramme selenite in a 
 litre of water (=8° hardness, Clark's scale). It is used for ' setting ' soap 
 solution. 
 
 13. Ferrous Ammonium Sulphate. — 0-7 gramme of the crystallised double 
 salt in a htre of water. Each 1 c.c.=-yV niilligramme iron. 
 
 14. Soap Solution. — 9 c.c. give a permanent lather with 50 c.c of a solu- 
 tion of calcium sulphate (CaS04-2H20) containing 0-1965 gramme in a Htre 
 of distilled water. 
 
 BACTEEIOLOGICAL EXAMINATION. 
 
 Many, if not most, waters contain bacteria, as Avas shown by Dr. Burdon 
 Sanderson (' Twelfth Eeport of Medical Officer of Privy Council,' 1870, p. 229); 
 and there are several methods used for the bacteriological examination of 
 water. These methods have not, however, come into general use, because 
 no means are knoAATi which enable the microscopist and analyst to dis- 
 criminate between pathogenic, zymogenic, and presumably inert bacteria by 
 mere inspection. The bacteria of unwholesome water hquefy gelatine 
 cultivation-media more readily than those from wholesome waters ; but this 
 summary embraces most that is known of the subject of the significance of 
 bacteria in di'inking-water. Some chemists attach importance to the 
 number of colonies of organisms which may be developed in a cultivation- 
 area by moculation with the water ; but it cannot be said that it is certainly 
 known that there is any definite relation between the number of organisms 
 a,nd the miwholesomeness of the water. To Koch is due the merit of having 
 introduced exact methods of discriminating between various kinds of 
 bacteria. 
 
 Dr. Angus Smith's method is a good one for recognising that micro- 
 organisms are present in water, though less useful in determining their 
 characters. It consists in introducing, by means of a capillary sterilised 
 pipette, drops of the fluid into gelatine or gelatine-broth in test tubes 
 plugged A\ith sterilised cotton-wool, and heated to 35°-40° C. (95°-104° F.). 
 The tubes are then shaken so as to distribute the uioculated liquid through 
 the gelatine, which is then allowed to cool and set. After a few days the 
 colonies of organisms that liquefy gelatine may be recognised as clusters 
 disseminated through the gelatine (which they liquefy). The size of the 
 clusters, their appearance and groupings, are then noted. Dr. Percy Frank- 
 land ('Proceedings of Koyal Society,* vol. xxxviii., 1885, p. 379) and Dr. 
 Warden, of Calcutta (' Chemical News,' vol. lii., 1885, pp. 52, QQ, 73, 89, 
 and 101) have pubHshed valuable methods of determining the relative 
 numbers of micro-organisms present in waters, by means of plate cultiva- 
 tions. This may be done by adding a measured small quantity of the 
 
WATEB 297 
 
 water to be examined to a definite quantity of liquefied sterilised nutrient 
 gelatine, in a sterilised test tube. The mixture is well shaken and poured 
 into a glass plate, placed beneath a bell glass in a moist chamber, and kept 
 at a temperature of 70°-72° F. (21°-22° C). After a few days the number 
 •of colonies, their shape, size, colour, and other characters, may be noted. 
 
 Dr. Klein (' Micro-organisms and Disease,' 3rd ed., p. 49) recommends 
 the following method for the examination of any sample of water for micro- 
 organisms. The water is allowed to stand for a few hours, till most of the 
 particulate matter has subsided, and then a little of the fluid and sediment 
 is withdrawn by means of a long capillary pipette. Some of the fluid and 
 sediment thus removed is used for microscopic examination whilst fresh ; 
 whilst another portion is prepared after the "Weigert-Koch method, by 
 spreading out the fluid on a cover-glass in a thin layer, drying it, fixing by 
 passing three times through a flame, staining with a suitable aniline dye, 
 such as methyl-blue, magenta, or gentian-violet ; washing successively with 
 water, alcohol, and distilled water ; drying, and then mounting the preparation 
 in Canada balsam dissolved in benzene or xylol. Test tubes containing 
 sterilised cultivation material — such as agar-mixture, gelatine, or Pasteur's 
 fluid, are also inoculated with the fluid in the pipette, by piercing the plug 
 of cotton-wool with this. The test tubes are then placed in the incubator 
 for a day or two, and then a portion is withdrawn by means of a capillary 
 pipette, and used for microscopic examination in order to ascertain what 
 kinds of organisms are present ; for the unaided eye generally suffices after 
 ;a day or two's incubation to ascertain whether organisms are present or not. 
 New cultivations may also be made from the first cultivation. 
 
 The following method of plate cultivation is recommended on good 
 authority (' Crookshank's Manual of Bacteriology,' 2ud ed., pp. 72 and 367). 
 A shallow glass dish is placed on a tripod stand, filled with water, covered 
 with a glass plate, and the level carefully adjusted by means of a spirit- 
 level, which is then removed, and replaced by a piece of filter-paper the size 
 of the glass plates to be used, and then covered with a bell-glass. The 
 glass plates are put into an iron case and steriKsed in a hot-air steriliser 
 heated to 150° C. (302° F.), where they are kept for an hour or two. The 
 -water in the dish is now cooled by means of crushed ice ; a sterilised plate 
 is removed from the box by means of sterilised forceps, held between the 
 finger and thumb by opposite edges, and rapidly transferred to the filter-paper 
 on the glass plate. The vessel containing sterilised gelatine is warmed in a 
 vessel of water heated to 30° C. (86° F.), inoculated with the sample by 
 means of a sterilised pipette, and well mixed by shaking, avoiding the 
 formation of air-bubbles ; the bell-glass is raised, and the gelatine is poured 
 on to the plate, the plug being previously removed, and the gelatine is 
 quickly spread over the plate by means of a sterilised glass rod to ^dthin 
 ialf an inch of the border of the plate. The bell-glass is replaced, and the 
 gelatine allowed to set. When quite set, the plate is transferred to the 
 "damp chamber. 
 
 In two or three days the cultivation may be examined, and the colonies 
 •counted ; and for this purpose a glass plate ruled into square centimetres, 
 .arranged on a frame so that it may be placed over the plate containing the 
 •cultivation, may be requisite, so that the number of colonies beneath one 
 square, and the number of liquefying colonies also, may be counted. In- 
 dividual organisms may then be examined by means of cover-glass prepara- 
 tions, and by further inoculations of nutrient gelatine and other media. 
 
 Dr. Dupre (' Eeport of the Medical Officer,' iii 14th Eeport, 1884, p. 304; 
 1.5th Eeport, 1885, p. 309 ; and 17th Eeport, 1887, p. 272, of the Local 
 
298 HYGIENE 
 
 Government Board), lias investigated the changes effected in the aeration of 
 waters by the Hfe processes of particular micro-organisms mider different con- 
 ditions of temperature, light, and nutrient material ; but all that can at pre- 
 sent be said is, that some organisms cause the disappearance of oxygen under 
 the influence of organic matter in the light, others only in the dark. 
 
 Dr. W. K. Smith in the preliminary report on the Differentiation and 
 Identification of Micro-Organisms found in Water-supplies (' Eeport of the 
 Medical Officer, 17th Eeport, 1887,' p. 2G8) has investigated the micro-organisms 
 in the water supplied by two of the London Water Companies. His method 
 was to make gelatine plate cultivations at 20° C. (G8° F.), and agar plate 
 cultures at 30° C (8G° F.) ; and with the organisms thus developed mice were 
 inoculated ; but in no case was any noteworthy result obtained. He did not 
 detect any disease-producing organism, but colonies of microphytes of multi- 
 farious character, such q.s Bacilhis fl^iorescens liqiiescens, Staplycocciis flaviis 
 liqucscens, Bacillus erythrosporus, and others whose identity with knowa 
 organisms was not established. But, whatever method be adopted, the 
 information afforded is at present of very limited value, for (1) all the orgaji- 
 isms introduced into the culture medium may not be capable of propagation 
 in this latter ; (2) each colony may possibly be the produce of one or more 
 individual organisms, but this is not likely ; (3) accidental contamination of 
 a water after coliecdon may readily occur. 
 
 CnAEACTEEISTICS OF GOOD DEINKING-^yATEE 
 
 In their celebrated ' Sixth Eeport,' the Elvers' Pollution Commissioners 
 made the following weighty remarks : — 
 
 ' In respect of wholesomeness, palatability, and general fitness for drinking 
 and cooking, our researches lead us to the following classification of waters 
 in the order of their excellence, and founded upon their respective sources. 
 
 [1. Spring water \ Very 
 
 J 2. 
 
 ' Wholesome . J 2. Deep-well water j palatable. 
 
 I 3. Upland surface water . . • ' | Moderately 
 
 • Suspicious . J ^- ^^^^^^ ^'^^'^ ^'^*^^' • ; • • • ^ palatable. 
 
 I 5. Surface water from cultivated land . | 
 
 [ G. Eiver water to which sewage gains ( p„]„|„uig > 
 
 'Dangerous . - access 
 
 ( 7. Shallow- well water . . . . j 
 
 And they urge that preference should always be given to spring and deep 
 well water for purely domestic purposes, over even upland surface water, not 
 only on account of the much greater intrinsic chemical purity and palatability 
 of these waters, but also because their physical qualities render them 
 peculiarly valuable for domestic supply, since they are almost invariably 
 clear, colourless, transparent and brilliant — qualities which add greatly to 
 their acceptability as beverages ; whilst their uniformity of temperature 
 throughout the year renders them cool and refreshing in summer, and 
 prevents them from freezing readily in winter. Their inestimable value to 
 communities in these respects are, however, in some degree neutralised as 
 regards temperature when they have to be stored ; and too often the 
 quantities available are inadequate to supply the needs of large communities 
 and too costly. Hence, we find that for large towns, upland surface water- 
 supphes are now being largely adopted; as witness Glasgow from Loch. 
 
WATEB 299- 
 
 Katrine, Manchester from Lake Thirlmere, and Liverpool from Lake Vyrnwy. 
 Often, too, it is desirable, and more especially in the case of a manufacturing 
 community, to have not only an organically pure and a palatable, but also a 
 soft water supply ; and here the advantage of an upland surface water 
 becomes manifest. 
 
 The geological strata through which a spring or deep well water has 
 percolated will greatly influence its palatability. Whilst surface waters are 
 often vapid and tasteless, or have a peaty bitter flavour, in percolating 
 through deep rocky strata, oi^ganic matter is oxidised ; and such waters are 
 often highly charged with carbonic acid gas, which renders them brisk and 
 palatable. The waters drawn from the deep artesian wells in the Thames 
 basin are often deficient in oxygen, and faintly opalescent. Some, too, con- 
 tain traces of sulphuretted hydrogen, and require exposure to the air to 
 render them palatable ; whilst others, again, when stored become filled with 
 confervoid growths. The spring waters of the magnesian limestone forma- 
 tion are not only excessively hard, but contain such a proportion of mag- 
 nesian salts as, in the opinion of most authorities, render them unfit for 
 drinking purposes. A pure magnesian water may nevertheless, it is thought 
 by many, form a good water for domestic use. The experience of Sunderland 
 and Bristol is not unfavourable to the use of magnesian waters. The deep 
 well waters of some of the beds of the New Eed Sandstone are rich in gypsum 
 as well as in chalk, and, though palatable, are excessively hard. 
 
 Various arbitrary standards have been laid down defining the amounts 
 of organic matter, as measured by one or other of its elementary constituents, 
 permissible in drmking-water. All are more or less unsatisfactory ; for it is 
 the kind rather than the amount of organic matter that renders this injurious. 
 All recent advances in medicine point to the presence of organised organic 
 matter, or possibly definite chemical bodies the products of changes evoked 
 by organisms, as the potent factors in producing those diseases referrible to 
 the use of polluted water. Hence, standards having reference to the quality 
 rather than the quantity of organic matter present in waters are desirable ; 
 but no such satisfactory standards have been hitherto devised. There are, 
 however, the three modes of detecting, or rather gauging, the quantity of 
 organic matter present in a water already described ; and these, by the aid of 
 other data often available, enable the practitioner in public health to arrive 
 at a satisfactory conclusion as to the potability or the probable noxious 
 character of a water. These methods are, the organic combustion process 
 of Dr. Frankland, the Wanklyn process, and the permanganate process 
 respectively, and are commonly known by the names of those chemists ; and 
 the permanganate is often referred to as Dr. Tidy's process, he having 
 improved upon the older permanganate processes previously used. The 
 assessment of the values to be attached to each of the determinations of a 
 water analysis, and to the whole determinations collectively, is a subject on 
 which the greatest diversity of opinion has existed among chemists, and 
 which still exists to some extent. It is chiefly over the determinations of 
 organic matter, and the determinations, such as the amount of oxygen 
 absorbed from permanganate, which serve as indices to the amount of 
 organic matter, though not directly serving as measurers of this, that the- 
 battle of water-analysis has raged most furiously ; but most, perhaps, of all 
 as to relative values of the figures obtained by the Frankland combustion 
 and the Wanklyn albuminoid ammonia processes. The writer of this article 
 is of opinion that a water must be judged — so far as it can be judged by 
 analysis alone — by the whole results of the analyses, and not by one con- 
 stituent, be it organic nitrogen or albuminoid ammonia, alone. But he- 
 
300 HYGIENE 
 
 deprecates, nevertheless, the attempt made by the late Mr. Wigner and by 
 other members of the Society of PubHc Analysts (' Analyst,' 1881, vol. vi., 
 p. Ill) to attach a numerical value to the amount of each one of the impor- 
 tant constituents, such as total solids, hardness, chlorine, ammonia, &c., 
 and then to assess the impurity of a water by a summation of those numbers, 
 e.g. saying that the impurity of a water is 20, 10, 17, &c., as the case may 
 be. The values attaching to the determinations of the several constituents 
 of a water will now be briefly discussed ; but it will be well first to set out 
 the opinions of some leading authorities as to the deductions to be drawn 
 from analytical analyses of waters. 
 
 Dr. Franlvland thiis classifies waters according to their organic purity 
 ('Water Analysis,' p. 80) :— 
 
 Upland Sukface Wateb 
 
 Class I. Wafer of great organic purity, containing a proportion of 
 organic elements (organic carbon and organic nitrogen) not exceeding 0*2 
 part in 100,000 parts of water. 
 
 Class 11. Water of mcdiitm purity, conizhmng fi-om 0*2 to 0*4 part of 
 organic elements in 100,000. 
 
 Class III. Water of doubtful purity, containing from 0*4 to 0*6 part of 
 organic elements in 100,000. 
 
 Class IV. Impure ivater, containing more than O'G part of organic 
 elements in 100,000. 
 
 Watek othek than Upland Surface 
 
 Class I. Water of great organic purity, containing a proportion of 
 organic elements not exceeding O'l part in 100,000. 
 
 Class II. Water of medium purity, containing from 0*1 to 0*2 part of 
 organic elements in 100,000. 
 
 Class III. Water of doubtful purity, containing from 0*2 to 0*4 part of 
 organic elements in 100,000. 
 
 Class IV. Impure ivater, containing upwards of 0'4 part of organic 
 elements in 100,000. 
 
 Dr. Frankland thus further classifies waters {ibid., p. 97) : — 
 
 1. Beasojiably safe waters. — Water, although it exhibits previous sewage 
 or animal contamuiation, may be regarded as reasonably safe when it is 
 derived either from deep wells (say 100 feet deep) or from deep-seated 
 springs, provided that surface water be carefully excluded from the weU or 
 spring, and that the proportion of previous (sewage) contamination do not 
 exceed 10,000 parts in 100,000 parts of water (i.e. the inorganic nitrogen 
 does not exceed 0-968 part per 100,000, or 0-678 grain per gallon, — T.S.). 
 
 Suspicious, or doubtfiol water is (1) shallow-well, river, or flowing 
 water which exhibits any proportion, however small, of previous sewage or 
 animal contamination ; and, 2nd, deep-well or spring water containing from 
 10,000 to 20,000 parts of previous (sewage) contamination in 100,000 parts 
 of water (i.e. 0-968 to 1*92 part inorganic nitrogen per 100,000, or 0-678 to 
 1-344 grain per gallon). 
 
 Dangerous water is (1) shallow-well, river, or flowing water which ex- 
 hibits more than 20,000 parts of previous animal contamination in 100,000 ; 
 (2) shallow well, river, or flowing water containing less than 20,000 parts 
 of previous (sewage) contamination in 100,000 parts, but which is known, 
 from an actual inspection of the well, river, or stream, to receive sewage, 
 
WATER 301 
 
 either discharged into it directly, or mingliBg with it as surface drainage ; 
 (3) as the risk attending the use of all previously contaminated water 
 increases in direct proportion to the amount of such contamination, the 
 water of deep wells or deep-seated springs exhibiting more than 20,000 
 parts of previous contamination in 100,000 must be regarded as dangerous. 
 Eiver or running water should only be placed in the second class pro- 
 visionally, pending an inspection of the banks of the river and tributaries, 
 which inspection will obviously transfer it either to the class of reasonably 
 safe water if the previous contamination be derived exclusively from spring 
 water, or to the class of dangerous water if any part of the previous con- 
 tamination be traced to the direct admission of sewage or excrementitious 
 matters. 
 
 Dr. Tidy thus formulates his own conclusion as to the respective merits 
 of the various processes for the determination of organic matter in water 
 (' Journal of Chemical Society,' vol. xxxv., 1879, p. 96) : — 
 
 1. As regards the ammonia process, an absolute or nearly absolute 
 freedom from albuminoid ammonia is for the most part an indication of 
 organic purity. Nevertheless, many waters which are very impure give a 
 trace only of albuminoid ammonia, whilst some which are very pure give 
 large quantities of albuminoid ammonia. Its results, therefore, are marked 
 by singular inconstancy. 
 
 2. That the ammonia process allows of no sufficiently large scale where- 
 by the finer grades of purity or impurity can be recognised and classified. 
 The errors arising from many causes — such as, amongst others, the ammonia 
 present in the permanganate solution itself, the difference in time required 
 by different organic bodies for their complete destruction, the chances of the 
 organic nitrogen becommg oxidised, the constant multiplication of errors 
 of observation resulting from collecting several distillates in which the 
 ammonia is to be severally determined, and which errors are again doubled 
 in order to convert results into parts per million — form an array of difficulties 
 likely to lead to serious errors, seeing that the range (viz., from 0-05 to 0*1 
 part per million) between waters of extraordinary organic purity and dirty 
 waters is comparatively small. 
 
 3. That, as regards the combustion process, the necessity for evaporating 
 the water to dryness constitutes a difficulty, the chances being that some of 
 the organic matter, and possibly that subtle form of organic matter specially 
 active in producing disease — the very organic matter, in fact, the detection 
 of which the sanitarian expects from the chemist — may be either mechanically 
 carried off, or volatilised, or oxidised, or even destroyed under the peculiar 
 conditions of the evaporation. 
 
 4. That, barring this objection, the estimation of the organic carbon in 
 the water residue is trustworthy, repeated experiments with the same water 
 yielding constant results. 
 
 5. That the estimation of the organic nitrogen is by no means so con- 
 stant, the possibility of the nitrate not being completely reduced, especially 
 when present in quantity ; of impurities in the sulphurous acid solution ; of 
 occluded nitrogen in the metallic copper ; and, lastly, the necessary error of 
 experiment, constituting a series of difficulties which must somewhat impair 
 the nitrogen determination. 
 
 6. Under such circumstances, the process can scarcely be considered to 
 yield absolutely trustworthy evidence (unless the organic nitrogen be beyond 
 a certain quantity) on which to found an opinion as to the probable source of 
 the organic matter in the water. 
 
 7. As regards the oxygen process, he claims for it that it is conducted on 
 
302 HYGIENE 
 
 the original -water and without the application of heat. Hence we avoid the 
 evils both of gain and of loss arising from, and incident to, the evaporation 
 of the water to dryness at high temperatures. Moreover, the analysis can 
 be conducted ^\ith the smallest possible amount of handling, or of pouring 
 the water fi-om vessel to vessel. 
 
 8. That the process gives results of great constancy and of extreme 
 delicacy. They admit, moreover, of a very wide scale in their classifica- 
 tion. 
 
 9. That the oxygen process allows us to draw a sharp distinction between 
 the putrescent or readily oxidisable organic matter, which is the more likely, 
 to use Dr. Frankland's term, to be ' pernicious,' and the non-putrescent or 
 less readily oxidisable matter, which is probably harmless so far as its action 
 on the human body is concerned. 
 
 10. That the general inorganic constituents of the water have no action 
 on potassic permanganate. 
 
 11. The inorganic constituents most likely to be present in a water that 
 would interfere with the estimation of the organic matter by potassic 
 permanganate are nitrites, metallic protoxides (especially ferrous salts), and 
 sulphuretted hydrogen, all of which are certain to be detected in the course 
 of a proper and complete water analysis, and corrections made accordingly. 
 
 12. That in the oxygen process the only modifying circumstances are 
 those which would render the oxygen required by the water excessive, and 
 that therefore, although we might be led to report unfavourably on a harm- 
 less water, the results obtained would never lead us to report favourably on 
 a bad water. 
 
 13. That whilst he does not consider that the oxygen process can be 
 employed with scientific precision as a direct quantitative test of the total 
 organic impurity of a water, nevertheless the results afforded by it indicate 
 with sufiicient precision the comparative quantity present Ukely to be injurious 
 to health. 
 
 14. That the results obtained by the ox3'gen process must at all times be 
 controlled by the natural history, as weD as by the general, chemical, and 
 physical examination of the water. 
 
 15. That, so far as the three processes — viz. the combustion process, the 
 ammonia process, and the oxygen process — are concerned, the oxygen and 
 the combustion processes give closely concordant results, whilst the results 
 yielded by the ammonia process are often at direct variance with both. 
 
 After a full consideration of the respective merits of the Forchammer, 
 or oxygen, and the combustion processes, Dr. Frankland (' Water Analysis,' 
 p. 57) gives the following scale of classification of drinking-waters, suggested 
 by Dr. Tidy and himself : — 
 
 Upland Surface Water 
 
 Class I. — "Water of great organic purity, absorbing from permanganate of 
 potash not more than 0*1 part of oxygen per 100,000 parts of water, or 0'07 
 grain per gallon. 
 
 Class II. — "Water of medium purity, absorbing from 0*1 to 0'3 part of 
 oxygen per 100,000 parts of water, or 0-07 to 0'21 grain per gallon. 
 
 Class III. — "Water of doubtful purity, absorbing from 0-3 to 0-4 part per 
 100,000, or 0-21 to 0-28 grain per gallon. 
 
 Class IV. — Impure water, absorbing more than 0*4 part per 100,000, or 
 0'28 grain per gallon. 
 
WATEB 303 
 
 Water other than Upland Surface 
 
 Class I. — Water of great organic purity, absorbing from permanganate 
 of potash not more than 0"05 part of oxygen per 100,000 parts of water, or 
 0-035 grain per gallon. 
 
 Class II. — Water of medium purity, absorbing from 0*05 to 0'15 part of 
 oxygen per 100,000, or 0'035 to O'l grain per gallon. 
 
 Class III. — Water of doubtful purity, absorbing from 0'15 to 0'2 part of 
 oxygen per 100,000, or 0"1 to 0'15 grain per gallon. 
 
 Class IV. — Impure water, absorbing more than 0'2 part of oxygen per 
 100,000, or 0'15 grain per gallon. 
 
 Mr. Wanklyn's standards of organic purity are as follows (' Water 
 Analysis,' p. 68) : — 
 
 Glass I, — Water of extraordinary organic purity, yielding from -00 up to 
 •05 part of albuminoid ammonia per million. This class comprises the 
 most carefully prepared distilled water and highly filtered waters, both 
 natural (i.e. deep spring waters) and artificial (i.e. such water as has passed 
 through a ' sihcated carbon filter' in good working order). Occasionally a 
 river-water in its unfiltered condition falls into this class. Water of this 
 class cannot be objected to organically. 
 
 Class II. comprehends the general drinking-waters in this country. It 
 gives from 0*05 to 0*10 part of albuminoid ammonia per milhon. Any 
 water falling fairly into this class is safe organically. 
 
 Class III. comprehends the dirty waters, and is characterised by yielding 
 more than O'lO part of albuminoid ammonia per million. 
 
 The writer is of opinion that no water should be judged by the quantity of 
 any one or two constituents which it may contain, but that the composition of 
 a water as a whole should be taken into consideration in passing judgment 
 upon its presumable safety when used as a drinking-water, and its admis- 
 sibihty as a source of domestic supply. To rely upon organic carbon, or 
 albuminoid ammonia, or ammonia, or oxygen (from permanganate) con- 
 sumed, may lead to the rejection of a good, or to the adoption of a bad 
 water. It may, therefore, be advisable to offer some observations upon the 
 various constituents of waters. 
 
 Gases. — Waters vary considerably in the proportions of their gaseous 
 constituents. When freely exposed to the air, a good water which is not 
 consuming oxygen by means of the organic matter, nitrites, or ferrous salts 
 which it contains ought to contain about If cubic inches of oxygen per 
 gallon ; and, to be palatable, to contain a fair proportion of carbonic acid 
 gas in solution, so as to be brisk and not vapid in flavour. 
 
 Odour. — There should be none ; but the presence of a trace of sulphuretted 
 hydrogen odour when freshly drawn from a deep source is not prohibitory of 
 its use. 
 
 Taste. — This should, of course, be agreeable, and not distinctive of any 
 special substance, subject to the qualification just given. 
 
 Turbidity. — There should be none ; or, if any, this should be due to 
 vegetable or mineral matters, and easily removable. 
 
 Colour. — There should be none ; but a slight peaty colouration is no bar 
 to the use of the water. 
 
 Keeping -Powers. — A good drinking-water, when kept in a bottle loosely 
 plugged with sterihsed cotton-wool, should not become putrid, nor deposit 
 anything beyond an inconsiderable amount of chalky matter. 
 
304 HYGIENE 
 
 Total Solids. — The amount of solids iii a good drinking-water is a very- 
 variable amonnt, and depends a good deal on tlie geological stratum of the 
 district. Dr. E. Parkes was of opinion that a good potable water should 
 not contain more than 35 grains per gallon of solids, or 50 per 100,000. 
 As a matter of fact these may range from 4 per gallon, or 6 per 100,000, 
 to 50 or 60 grains per gallon or 80 per 100,000 ; and no doubt even these 
 last figures may exceptionally be exceeded. Some of the best artesian 
 well-waters in London contain over 50 grains per gallon of solids, much of 
 which is common salt ; and the highly valued table-waters imported from 
 the Continent contain nearly 100 grains per gallon of mineral constituents, 
 or 140 per 100,000. It is, indeed, rather the quality than the quantity of 
 mineral matter present which is to be regarded in judging of the suitability 
 of a water for domestic use. As a rule, however, those waters which con- 
 tain least mmeral matter are deemed most suitable for domestic supplies, 
 though there is high authority for thinking that a certain amount of chalk 
 in a water is beneficial. In one respect this is an advantage, for such 
 waters, being slightly alkaline, act but little on lead ; whereas the soft waters 
 containing little solid matter are often acid, and act freely upon leaden pipes 
 and cisterns. 
 
 Loss on Ignition. — The loss which the dry solid matter obtained by 
 evaporation of the water under examination undergoes when ignited is 
 nowadays but little regarded. When coupled with the manner in which 
 the solids behave during the burning process, this determination is, however, 
 a valuable one. The blackening, the odour, and the character as regards 
 colour and acidity of the fumes evolved should by no means be neglected, 
 for in this way the experienced analyst will obtain valuable information. 
 The actual amount of loss — correction being made for the substitution of 
 the N2O5 radical of nitrates by the CO2 radical of carbonates during ignition 
 — is also an index of quality, provided chlorides and sulphates are not very 
 abundant. When these are present, the loss is increased by the loss of water 
 of hydration of these salts not expelled at the temperature at which the 
 water residue was dried in the oven. In an undoubtedly good water the 
 loss on ignition is small — 1 or 2 grains perhaps per gallon — and the residue 
 during ignition, though it may assume a shade of brown or grey, never 
 really blackens or evolves the odour of burnt feathers. 
 
 Hardness. — The use of a water of more than 20 degrees of hardness 
 (Clark's scale) is undesirable ; and an ordinary good water ought not to 
 have more than 15 degrees of hardness. The use of a water of 25 degrees 
 of hardness is, however, permissible when no softer water is available. The 
 permanent hardness of a good water should not exceed 5 degrees. 
 
 Nitrates. — The nitrogen as nitrates should, in no case, exceed 1 grain 
 per gallon ( = 3-86 grains N2O5) ; 0-7 gram N ( = 2-7 grains N2O5) per gallon 
 is a safer Hmit. 
 
 Nitrites.- — ^These should be absent. 
 
 Ghlorijie. — If the chlorine exceeds 1*5 grain per gallon, its source should 
 be inquired into ; and if there be also much ammonia, and especially 
 albuminoid ammonia, or organic carbon present, or if the water consumes 
 much oxygen in the permanganate process, sewage contamination may be 
 apprehended. The deep artesian well waters of the London basin contain 
 much chlorine and ammonia, and are wholesome ; but they yield little 
 organic carbon and albuminoid ammonia, and they consume little oxygen 
 (from permanganate). 
 
 Organic Matter. — The loss on ignition should not exceed 2 or 3 grains 
 per gallon of water, and the fumes evolved during ignition should have no 
 
WATER 305 
 
 animal odour. The evolution of ruddy acid vapours indicates excess of 
 nitrates. Albuminoid ammonia should not exceed 0*01 grain per gallon 
 (0"15 per million) except in the case of peaty waters, when the albuminoid 
 ammonia is evolved slowly. Ammonia (so-called ' free ' ammonia) ought 
 not to exceed 0*002 grain per gallon, except in the case of an artesian well- 
 water. If the oxygen consumed in the permanganate process exceeds 0*2 
 grain, or at most 0"25 grain per gallon, the purity of the water is open to 
 grave suspicion. Organic carbon should not exceed 0-3 grain per gallon, 
 nor organic nitrogen exceed 0-03 grain per gallon ; and whenever the ratio 
 of organic C to N is less than 5 to 1, the water is open to suspicion. 
 
 Only one or two of the determinations — organic carbon plus organic 
 nitrogen, albuminoid ammonia, oxygen consumed — are usually employed in 
 conjunction with the other analytical data in judging of the quality of a 
 water-supply. Koch is of opinion that a normal water is one which contains 
 less than 300 germs in each cubic centimetre. Plugge and Kroskauer would 
 not permit more than 50 to 150 germs at the most, and the Swiss Society of 
 Analytical Chemists fixed the latter figure as their maximum. A. Pfeiffer 
 condemns a water when the germs reach 1000 per cubic centimetre (Ferd. 
 Fischer, * Zeitsch. f. Angew. Chemie,' 1889, No. 18). These conclusions are 
 widely diverse, and no account is taken of the kinds of germ met with. 
 It is obvious that until we have some means of distinguishing between 
 innocent, and perhaps beneficent, germs and those which are disease- 
 producing, the mere counting of germs is a valueless operation. 
 
 Injurious Metals. — The water should yield no colouration, or only the 
 faintest tint of colour, on the addition of tincture of galls (absence of excess 
 of iron), and it should not darken on the addition of a drop of sulphide of 
 ammonium followed by a drop or two of strong hydrochloric acid (absence of 
 lead and copper). 
 
 BIBLIOGEAPHY 
 
 Eeports of the Eivers Pollution Commission (1869), 1 to 10. 
 
 Eeport of the Eoyal Commission on Water Supply, 1869. 
 
 A Manual of Practical Hygiene. By E. A. Parkes. Edited by J. Lane Hotter. 
 
 8th ed. 1891. 
 Experimental Eesearches. By E. Frankland. 1877. Chapters on Drinking Water, 
 
 pp. 551-683. 
 Water Analysis for Sanitary Purposes. By E. Frankland. 2nd ed. 1890. 
 Water Analysis. By J. A. Wanklyn and E. T. Chapman. 7th ed. 1889. 
 The Organic Analysis of Potable Waters. By J. A. Blair. 1890. 
 Potable Waters. By C. Ekin. 1880. 
 
 VOL. I. 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 BY 
 
 S. MONCKTOJSr COPEMAN, M.A., M.D.Cantab., D.P.H. 
 
 ASSISTANT LECTtJREB ON PHYSIOLOGY AT ST. THOlLiS'S HOSPITAL 
 LATE SCHOLAR, EXHIBITI03SrER, AND PRIZEMAN OF CORPUS CHRISTI COLLEGE, CAMBRIDGE 
 
 x2 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 Fbom the times of Herodotus and Hippocrates to the present day, evidence 
 has been gradually accumulating as to the influence exerted by the nature of 
 the soil on the prevalence of certain diseases, more particularly malaria, to 
 which must now be added cholera, diarrhoea, typhoid or enteric fever, phthisis, 
 and many others which will be treated of in detail later on. 
 
 By the term soil is understood such portion of the earth's crust as has 
 been formed by the gradual disintegration through many ages of the rocks of 
 which the globe is mainly constituted. The composition of the soil therefore 
 varies considerably in different localities, but in comparing one with another 
 it is well to bear in mind the many other factors, in addition to the compo- 
 sition and condition of the soil, which from time to time may come into play. 
 
 A subdivision into surface soil and subsoil is generally recognised, and is 
 useful for practical purposes, seeing that the upper portion of the soil or 
 ' mould ' differs very materially from the subsoil in composition. The latter 
 consists for the most part of inorganic materials, while the former may 
 contain in addition large quantities of organic matter, both animal and vege- 
 table in origin, the role of which is a most important one, since it is in great 
 measure to these constituents, and the manner in which they are affected by 
 varying degrees of moisture, temperature, and aeration, that the effect pro- 
 duced on the health of the community is due. 
 
 Above the rock which will be found at the lowermost portion of a section 
 perpendicular to the surface of the earth, we find then the subsoil, which 
 results from the breaking up of the rock under the influence of various 
 agencies, such as the percolation of water containing various gases and other 
 substances in solution, or from the irresistible onslaught of the roots of trees 
 which, forcing their way gradually downwards, spht it asunder. The subsoil 
 is thus continually eatmg its way into the rock beneath, to compensate for 
 which, influences are as continually at work causing an imperceptible removal 
 of material from the surface of the soil. Above the subsoil again we find a 
 layer penetrated in all directions by the rootlets of the vegetation on the sur- 
 face, indicating a still further stage in the decay of the remains of the primi- 
 tive rock. This layer forms the true soil ; the subsoil being an intermediate 
 band where the progress of decomposition has not advanced so far. 
 
 If there is so intimate a connection between the soil at the surface and 
 the rock underneath, we can readily understand that soils should vary from 
 one district to another according to the nature of the underlying rocks. 
 Denudation of clays will produce clayey soil, sandstones sandy soil, or where 
 these two kinds of rock occur together, they may give rise to sandy clay or 
 loam. Hence, knowing what the underlying rock is, we may usually infer what 
 must be the character of the overlying soil, or from the nature of the soil, we 
 may form an opinion respecting the quality of the rock that hes below (GeiMe). 
 The soil of every locality, then, ought to be merely the decayed upper surface 
 of the rocks underneath, mingled with the remains of animal and vegetable 
 matter, were it not for the action of rain and other forces in removing material 
 to a greater or less distance from its source, by which in some instances a good 
 soil is laid down upon rocks which of themselves would only produce a poor one. 
 
310 
 
 HYGIENE 
 
 Since soils are formed more or less directly from the decomposition of 
 rocks, it will be advisable to mention shortly the manner of origin of these 
 rocks, and also their chemical composition. 
 
 The various rock-formations have been di%^ded under two principal heads 
 according to their mode of origin : the igneous and sedimentary rocks. The 
 first class, which includes only a few of the rocks with which we are now ac- 
 quainted, is believed to have been derived from the gradual coohng down of 
 the outer surface of the molten mass of wliich the globe at first consisted, 
 whence their name. Although the proportion of igneous rocks cropping up 
 above the surface in Great Britain is so small (even in North Wales, where 
 they are found to the greatest extent), still they are none the less of importance, 
 seeing that to their decomposition the origin of the later rocks is due. Of 
 the igneous rocks the most important is granite, which may exist in many 
 different forms, and after this the trap rocks, including the greensands and 
 basalt, which are looked upon by some as essentially the primary rocks from 
 the considerable resemblance which they show in chemical composition to 
 volcanic lava. 
 
 Granite of various kinds consists mainly of quartz, feldspar, and mica in 
 various proportions, although any one of these three constituents may be 
 absent, or replaced by some other substance. Thus a rock in which horn- 
 blende replaces mica is known as syenite, while, if both these substances are 
 present, it is termed syenitic granite. Gneiss, again, contains the usual ele- 
 ments of granite, but the crystals of quartz and feldspar are broken and in- 
 distinct. The trap rocks consist mainly of feldspar and hornblende (or augite, 
 which contains less sihca than hornblende), and the general composition 
 of the minerals composing the igneous rocks may be shown as follows : — 
 
 Analyses of Minerals {Lloyd) 
 
 
 
 Hornblende Mica 
 
 Feldspar 
 
 
 Without 
 Alumina 
 
 Witli 
 Alumina 
 
 Potash 
 
 Potash 
 Orthoclase 
 
 Soda 
 Albite 
 
 SocTa .... 
 
 Alumina 
 Manganese oxide 
 Calcium oxide (lime) . 
 Magnesium oxide 
 Potash 
 Ferrous oxide 
 Ferric oxide 
 Silica .... 
 Loss on ignition . 
 
 
 15-06 
 23-92 
 
 2-41 
 
 54-71 
 3-33 
 
 3-14 
 6-31 
 1-13 
 
 9-68 
 3-62 
 2-65 
 
 21-72 
 6-62 
 
 42-27 
 -48 
 
 4-10 
 36-23 
 
 •50 
 
 •37 
 
 6-20 
 
 1-34 
 
 44-60 
 
 5-26 
 
 17-50 
 
 1-25 
 
 12-00 
 
 1-75 
 66-75 
 
 11-47 
 19-43 
 
 •20 
 69-00 
 
 
 
 99-43 
 
 97-62 
 
 98-60 98^25 
 
 100^10 
 
 Quartz is not mentioned in the table, as it consists of almost pure silica 
 alone. Mica, hornblende, and feldspar, on the other hand, are of a much 
 more complicated nature, the main difference between hornblende and feld- 
 spar being seen in the large amount of lime and magnesia present in the 
 former, while in the latter there is much potash or soda, but practically no lime. 
 
 ' Thus the igneous rocks consist mainly of four elements : quartz, feldspar, 
 hornblende, and mica. From the decomposition of these rocks, and re-forma- 
 tion of the decomposed parts, the aqueous rocks have been formed.' The 
 terms aqueous or sedimentary are therefore used, because it appears that these 
 rocks must have resulted from the gradual solution and disintegration by 
 rain of the older igneous rocks, the fine particles of which, held in suspen- 
 sion in the water of streams, lakes, and seas, have thus been carried to lower 
 
THE INFLUENCE OF SOIL ON HEALTH 311 
 
 levels and then again gradually deposited, the resulting deposits constantly 
 increasing and forming accumulations of greater or less thickness, and 
 becoming arranged in layers or strata from the separation of the particles 
 of various size and shape. From this cause arise the differences in the 
 mechanical and chemical composition of the various sedimentary rocks, which 
 from the fact that they have either been formed by deposition in water in 
 the manner described, or by precipitation of matter held in sokition by the 
 water, all resemble one another in forming more or less distinct layers. 
 For this reason the term stratified has been applied to thorn ; the relative 
 time of their formation having given rise to the geological terms of primary, 
 secondary, and tertiary, by which the three main groups are distinguished. 
 
 These principal divisions of stratified rocks include about eighteen distinct 
 strata, on each of which a special name has been bestowed. The more impor- 
 tant of these are : — 
 
 The old red sandstone. 
 
 The new red sandstone (sandstone and marl). 
 
 The greensand formation (sandstone, clay, and sand). 
 
 /Lias. 
 Oxford. 
 The claystone formations -^ Kimmeridge. 
 
 Wealden. 
 
 VLondon. 
 
 (Mountain limestone. 
 The limestone formations < Magnesian ,, 
 
 [Oohtic „ (Bath stone). 
 
 The chalk formation. 
 
 From these various rocks the overlying soil has been for the most part 
 formed partly by the process of 'weathering,' but also in large part by the 
 action of both animal and vegetable life. As the plants on the surface die, 
 their remains gradually rot, as do those of others that succeed them, so that 
 by the gradual accumulation of the debris of successive generations, the sur- 
 face soil becomes more or less black, and is found to consist largely of organic 
 matter of vegetable origin. The animal world, too, is not unrepresented, 
 since not only those creatures which naturally live in the earth in such 
 enormous numbers, such as various insects and earth-worms, contribute their 
 quota after death to the constituents of the soil, but larger animals as well 
 which fell when dead upon the surface of the earth, or were purposely buried 
 beneath it, and thus in either case become in time incorporated with it. The 
 excrement of the animal world also is constantly being added to the soil, and 
 thus also gradually comes to form an integral part of it. In this way from 
 both plants and animals there is furnished to the soil that organic matter on 
 which its fertility so much depends, a fact the results of which have long been 
 known to agriculturists, who recognise the greater fertility of the upper 
 stratum of the soil, which differs in this respect from that immediately below it. 
 
 It might be supposed that the gradual formation of a covering of soil and 
 subsoil, particularly where there is in addition an overlying abundant vegetable 
 growth, would in course of time, by the protection it affords, come to prevent 
 any further decomposition and disintegration of the rock beneath ; although 
 this may be so to a certain extent, the process never ceases altogether. If it 
 were so, plants after a time would cease to grow from want of the necessary 
 inorganic constituents of the soil, and either the tract of country would be- 
 come a waste, or at most only the humbler forms of vegetable life would per- 
 sist. The continued growth of similar kinds of plants shows, however, that 
 
312 HYGIENE 
 
 they are able in some way or other to coutinue obtaining their necessary 
 nutriment from the soil, this in tmii depending on the decomposition of fresh 
 portions of the underlyhig rock. This is in fact due to the actual growth and 
 decay of the vegetation itself, since rain falling on the surface and gradually 
 percolating through the soil absorbs certain vegetable acids, the true nature 
 of which is still somewhat obscm'e, but which, when present to a considerable 
 extent, bestow on it a power of gradually eating into the substance of rocks 
 over which it flows. In the case of water issuing from extensive beds of peat, 
 for instance, the amount of these organic acids in solution would be suflicient to 
 produce an appreciable effect on the stones or rocks with which it came in con- 
 tact, limestone rock being particularly liable to corrosion from such a cause. 
 
 In addition, rain, as it percolates through the soil, carries down with it a 
 certain amount of oxygen and carbonic acid which it has dissolved from the 
 atmosphere, while more carbonic acid, which is always present to a certain ex- 
 tent m the soil itself, is dissolved by the water in its downward passage. Con- 
 stituents of the underlying rock are thus dissolved which would not be acted 
 upon by water alone. Limestone is particularly hable to be affected in this 
 manner, for though only a part of the rock may become dissolved, the re- 
 mainder will tend as the rock becomes exposed to become split up into frag- 
 ments by the subsequent action of frost. Carbonic acid also acts on iron, 
 which it dissolves in considerable quantity, and it causes the decomposition 
 of feldspar by combining with the potash and soda present in this mineral. 
 Oxygen also acts on all rocks which, like hornblende, contain salts of iron, 
 the green ferrous compounds being converted into red ferric oxide, and thus 
 disintegration is also brought about. 
 
 The conjoined action of water and gases upon the rocks, which is termed 
 ' weathering,' is of necessity exceedingly slow, but when extended over periods 
 measured by centuries, it will be understood that enormous results may be 
 produced by the continuous disintegration which goes on. "Water, however,, 
 does not only act by virtue of the substances dissolved in it, but has a distinct 
 mechanical action as well. Thus we find that not only the primary rocks, 
 but those of a sedimentary nature also, are frequently more or less fissured, 
 and if the crevices exist in certain directions they will become more or less 
 filled with water after a time. If now a frost ensues, the expansion of the 
 water which occurs, as it becomes transformed into ice, will exert an immense 
 force which will not only tend to increase the extent of the fissure, but may 
 even spht off, not only fragments, but also considerable portions of the rock. 
 Naturally the results of this action will be more obvious in temperate 
 chmes, where there will be alternate frost and moderate heat in winter and 
 summer respectively, while in tropical countries, where frost is unknown, or 
 in the arctic regions, where it is perennial, the results of such will be com- 
 paratively shght. 
 
 Flowing water and the movements of glaciers have also both exerted 
 considerable influence in this direction ; fragments of rock becoming broken 
 off, and these continually rolling against one another are gradually broken 
 up into smaller pieces, the surface of the land thus becoming gradually 
 transformed. Much of the material thus broken up by the influence of water 
 or ice may be transported for a considerable distance and then again deposited,, 
 the soil thus formed being termed alluvial when deposited from water, and 
 drift when the result of glacial action. 
 
 Of the former class, the soils formed at the mouth of large rivers such as 
 the Nile are examples, while in England typical soils of this character are 
 found in the Fens of Cambridgeshire and Lincolnshire. On the other hand, 
 drift action has considerably modified the soil in many parts of Great Britain, 
 
THE INFLUENCE OF SOIL ON HEALTH 313 
 
 and for the most part improved it, since ' where slopes descend and are 
 covered more or less with old ico-drifts and moraine matter, the soil is deep 
 and the ground is fertile. The re-arrangement of the ice-borne d&hris has 
 served to cover large tracts of country with a happy mixture of materials, 
 such as clay mixed with pebbles, sand, and lime.' 
 
 There is, moreover, a constant transposition of soil going on, not only 
 from the washing away of the surface by rain or its removal by wind in the 
 form of dust, these being most noticeable where slopes are steepest or when 
 the weather is driest respectively, but from the substitution of new surface- 
 soil due to the upraising of a certain amount of material from deeper layers. 
 This is in part brought about by the labours of rabbits, moles, and other 
 animals in throwing out soil from their burrows, while in tropical countries 
 the termite or ' white ant ' carries an enormous amount of fine earth up into 
 the open air, forming hills in this manner which may rise to a height of as 
 much as sixty feet. The most enormous amount of work in this direction, 
 however, is performed, slowly it is true, but none the less surely, by earth- 
 worms. They disintegrate the soil, riddle it with burrows, and so admit air 
 to its deeper recesses, and in their castings bring up to the surface an almost 
 incredible amount of fine soil in the course of a year. Darwin has shoAvn 
 that in some places the quantity of earth raised to the surface may reach to 
 as much as ten tons to an acre. Thus inequalities tend to become levelled, 
 while stones and other material of an inorganic or organic nature are gradually 
 buried. The organic and excremental matter thus buried becomes to a large 
 extent the prey of various saprophytic fungi, which abound in the soil and 
 find in it a pabulum well suited to their needs. In earth they flourish 
 to a greater extent even than in the atmosphere, as might be expected, seeing 
 that the amount of food-material is so abundant, while for the same reason 
 they will be more abundant near the surface than at some distance 
 beneath it. 
 
 BACTEEIA AND THEIR INFLUENCE ON SOIL' 
 
 According to Fliigge, enormous rtumbers of bacteria have always been 
 found in the soil by various observers. Infusions made from manured field 
 and garden earth, even though diluted one hundred times, still contain 
 thousands of bacteria in every drop, and the ordinary soil of streets and courts 
 also shows the presence of large numbers. Bacilli are present in much the 
 largest numbers, but in the most superficial layers and in moist ground there 
 are also numerous forms of micrococci. 
 
 Through the agency of these bacteria, organic substances which reach the 
 soil, and which are for the most part retained in the superficial layers, 
 undergo gradual change, which for the most part is in the direction of oxida- 
 tion and occasionally in that of reduction or putrefaction. That such change 
 is brought about by the vital activity of micro-organisms is evident from 
 the fact that if the soil be sterilised, as by the action of heat, no such meta- 
 morphosis takes place in the chemical nature of its constituents. One such 
 property of great importance possessed by soil in virtue of the presence of some 
 one or more of these lowly organisms is that of nitrification, as was shown long 
 ago by Frankland, who found that the effluent from sandy soil over which 
 London sewage had been passed was clear, and contained the representatives 
 of the organic matter of the sewage .in the form of nitrates and nitrites. 
 Experimenting in a similar manner, Fodor found that when a fluid contain- 
 ing a considerable quantity of ammonia— a large excess of organic material with 
 1 Bacteria will be more fully dealt with in a paper by Dr. Klein. 
 
314 HYGIENE 
 
 a trace only of nitrites and nitrates— was poured over a certain amount of 
 earth, consisting of a mixture of humus and sand, he recovered in the 
 filtrate the faintest indication of ammonia only, about one-fortieth of the 
 organic matter, and nearly fifty times the amount of nitrates and nitrites. 
 He found, however, in addition, that if the sewage were poured too contmu- 
 ously on to the soil, the constituents accumulated in great part in the super- 
 ficial layers, and failed to undergo a similar conversion. 
 
 Schltising and Muntz showed in 1878 that the process of nitrification 
 •was dependent upon the presence of certain micro-organisms— that it was in 
 fact a fermentation change, but they did not succeed in isolating any one 
 form specially concerned. This has apparently been done quite recently by 
 Percy and Grace Frankland, who, by using a dilution method, have separated 
 what they term a bacillo-coccus, which is capable of inducing nitrification in 
 ammoniacal solutions inoculated with it. Warrington, however, in a recent 
 paper read before the Chemical Society, states that the nitrification performed 
 by soil appears to be the work of two organisms, one of which oxidises 
 ammonia to nitrite, while the other oxidises nitrite to nitrate. The first 
 organism is easily separated from the second by successive cultivations in 
 solution of ammonium carbonate. The second is (probably) separated as 
 easily from the first by successive cultivations in solution of potassium nitrite 
 containing monosodium carbonate. 
 
 It has been shown conclusively by Fliigge, Koch, and others, that the 
 various micro-organisms found in soil are much more numerous in the 
 superficial layers than at a greater depth. Indeed, at any distance from the 
 surface they are practically absent unless the soil has been deeply trenched, 
 as in preliminary drainage operations, or unless liquid filth from sewers and 
 cesspools lias been carried off beneath the soil. This is accounted for by 
 the fact that the soil is capable of retaining even such small bodies as 
 bacteria, when filtration of water or sewage is slowly carried on through its 
 interstices, although if the filtration be more rapidly effected such bodies will 
 be carried to a greater depth. ' Numerous filtration experiments, on a large 
 and small scale, have shown most distinctly that a layer of earth, half to one 
 metre in thickness, is an excellent filter for bacteria, and hence the purifi- 
 cation of fluids from bacteria must be still more complete in cultivated and 
 especially in clay soil, and where the fluid moves with extreme slowness. 
 Further, it has been repeatedly shown that wells which were protected against 
 contamination with bacteria from the surface an i, from the sides of the well 
 furnish a "SNater almost entirely free from bacteria ; that further, wells of 
 water containing bacteria become the purer the more water is pumped out, 
 and the more ground-water comes in from the deeper layers of the soil.' 
 
 That soil is capable of thus acting as a microbic filter can be shown by 
 the follo-fting experiment. A flask A (fig. 85), half filled with some nutrient 
 solution such as thin gelatine solution or peptone broth, is closed with a 
 tightly-fitting cork, through which passes a glass tube B of fairly wide calibre, 
 and somewhat constricted towards its lower end, which reaches down be- 
 neath the surface of the solution in the flask. Another tube C simply opens 
 into the interior just below the cork, in such a manner that its external 
 orifice is at right angles to the other tube B. C is now plugged with cotton- 
 wool, and B is filled with dry powdered earth, which is packed fairly tightly, 
 and the whole apparatus is then sterilised by heat. If now decomposing 
 mine be poured into the upper end of B, it will slowly filter through into the 
 flask, as vnW be seen from the heightened level of the contained fluid, but 
 no decomposition will be found to occur in the gelatine solution since the 
 bacteria will be retained in B. To show now that more rapid filtration 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 315 
 
 will carry them through into A, air is blown through the tube C, so as to 
 drive the nutrient solution in A into B, say as high as D. On stopping 
 the injection of air, the fluid will again rapidly rise in A, and putrefaction 
 will shortly set in. 
 
 That the oxidation of organic substances in soil, as evidenced by the 
 conversion of organic carbon into carbon dioxide and of nitrogen into nitric 
 acid, is effected by the vital activity of micro-organisms is indicated by the 
 following observations of Fodor : — 
 
 1. It is checked or stopped altogether by aspirating chlorine through the 
 soil. 
 
 2. It is favoured by a moderately high temperature thus 
 
 After the soil has been kept at 18° C. for three days, amount of CO, 
 
 volumes of air aspirated through soil 
 After being warmed to 60°-65° C. . 
 
 65°-95° C. . 
 
 95°-105° C. 
 
 105°-115° C. 
 
 115°-125° C. 
 
 in 1,000 
 
 = 1-05 
 
 = 2-30 
 
 = 2-40 
 
 = 1-00 
 
 = 0-58 
 
 = 0-15 
 
 So that the amount of carbon dioxide increases when the soil is heated to from 
 65°-75°C., remains stationary afterwards until the temperature reaches 95°C., 
 then decreases quickly and markedly. It does not disappear wholly even 
 when 137° C. is reached. 
 
 3. Schlosing and Muiitz,in the course 
 of their investigations on the influence 
 of organisms in the process of nitrifica- 
 tion in soil, found that the rapidity of 
 the changes going on was considerably 
 diminished when chloroform vapour was 
 forced through the soil ; proof of this 
 fact being seen in a decrease of nitrates 
 and nitrites in the effluent accompanied 
 by a correspondingly large increase in 
 the ammonia. 
 
 4. Nitrification, like other processes 
 of a similar nature in the soil, is much 
 less active than usual or may cease 
 altogether when the soil has been 
 thoroughly heated. Similarly Falk 
 found that thymol, naphthylamine, 
 nicotine, and other substances passed 
 undecomposed through soil which had 
 "been exposed to considerable heat, while 
 they wholly disappeared when added to 
 soil which had not been heated. 
 
 5. Different forms of bacteria, espe- 
 cially bacilli, occur in almost all samples 
 of earth. As the result of experiment 
 it would appear that oxidation is due 
 
 to the vital activity of micro-bacteria, while desmo-baeteria play a similar part 
 in putrefaction, since they are able to thrive in the absence of air. Moreover, 
 the bacteria concerned in nitrification are killed by exposure to a temperature 
 of between 90° and 100° C, which suffices to kill micro-bacteria, but not the 
 desmo-bacteria. Thus the fact that the formation of carbonic acid in soil 
 is greatly reduced at 100° C, though not wholly stopped by a considerably 
 
 Fig. 85. 
 
316 HYGIENE 
 
 higher temperature, may be explained by supposing that at the former point 
 the micro-bacteria, the chief producers of CO >, are killed, while the desmo- 
 bacteria, being capable of resisting even a higher temperature, survive and 
 ultimately regain their activity. 
 
 The temperature of the soil, and the amount of moisture contained in it, 
 are both important factors in determining the extent of changes going on as 
 the result of the presence of micro-organisms. Thus it has already been seen 
 that the amount of COo produced in soil containing abundance of organic 
 substances increases up to a temperature of about 60° C, v\rhile it is almost 
 entirely arrested, at a temperature of 100° C. or more. The amount of mois- 
 ture most favourable to the production of COo is reached when water is pre- 
 sent to the extent of about 4 per cent., although the surface maj be entirely 
 covered with water, as Schlosing showed in his experiments on nitrification, 
 without such changes becoming entirely arrested. Should the soil, however, 
 be perfectly dry, decomposition does not take place. 
 
 Ventilation of the soil is another important factor. Thus Fleck buried 
 rabbits in gravel, sand, and clay respectively, and found that decomposition 
 proceeded more rapidly in sand and gravel, which allowed freer access of air, 
 than in the more impermeable clay. Fodor states that if air be drawn 
 through a tube charged with earth rich in organic matter, the carbon dioxide 
 obtained increases in the same ratio as the velocity with which the air is 
 drawn through the tube, while Soyka also found that the nitrifying power of 
 soil increased when air was passed constantly through it. This effect, how- 
 ever, is not due to an increased supply of oxygen, since Schlosing, on aspira- 
 ting soil with air containing different proportions of this gas, found that when 
 more oxygen was supplied the production of carbon dioxide actually diminished, 
 while on the other hand a considerable amount of carbon dioxide was produced 
 when the aspirated air contained oxygen to the extent of only 1 per cent. 
 The suggestion has been made that aspiration may act in the manner de- 
 scribed, by removing products inimical to the organisms, in the sense that 
 alcohol is inimical to the life processes of the yeast-fungus, that substances 
 resulting fi'om putrefaction, such as phenol, indol, and skatol, restrain the 
 growth of putrefactive organisms, or that the products of digestion retard the 
 further action of digestive ferments. 
 
 The kind of decomposition that goes on in a given soil varies according 
 as air reaches the contained organic substances in small or large amount. 
 It varies, in fact, with ventilation of the soil and therefore with its permea- 
 bility to air, so that every natural i)henomenon wliicli alters the ventilation 
 of the soil will also modify the processes going on m it, sometimes favouring 
 oxidation, at other times putrefaction. Thus rising ground- water, by stopping 
 up the pores of the soil, will conduce to putrefaction, as will also freezing of 
 the upper layer of the soil, which destroys its permeability and thus favours 
 putrefaction in the deeper and warmer portions. Supersaturation with or- 
 ganic substances has a similar effect, and hence the soil of cities is prone to 
 undergo putrefaction rather than oxidation, both by reason of its greater de- 
 gree of pollution and of the obstruction offered by pavements and buildings 
 to due ventilation. That want of air is among the conditions for putrefaction 
 is indicated by an experiment of Frankland's in which, when an extra amount 
 of sewage was allowed to pass on to a certain field used for irrigation pur- 
 poses, the effluent, which before had contained considerable amounts of 
 nitrates and nitrites, now showed in their place undecomposed organic matter, 
 ammonia, and certain faintly- smelling gases. 
 
 ' The question whether among the bacteria which are found in the soil 
 some may not be hurtful to mankind is of great interest and importance. 
 
THE INFLUENCE OF SOIL ON HEALTH 317 
 
 If disease-causing organisms find a nidus in the soil, may they not multiply 
 or at least continue to live, and then prove a danger to health ? There 
 can be no doubt that pathogenic organisms do exist in the soil, but their 
 power for harm would seem to be practically very small indeed ; and to 
 regard the soil as dangerous because some pathogenic orgaaisms may lurk in 
 it would be as rational as it would be to eschew vegetable food because of 
 the occasional dangers of hemlock, aconite, or the deadly nightshade. It 
 seems to be a fact that the great doctrine of the " survival of the fittest " holds 
 good for microbes in the soil, as for all other organised bodies everywhere ; 
 and that organisms which flourish in the human body, languish and cease to 
 multiply in the soil, where the conditions are unsuited for their multiplication 
 or even for their survival. They get overgrown by saprophytic microbes, 
 and even if they do not die, the risk of their finding their way into the ground 
 water is practically nil, for we have seen that humus is the best of filters.' 
 (Vivian Poore.) 
 
 Although doubtless the great majority of bacterial forms inhabiting the 
 upper layers of the soil are simple saprophytes, organisms capable of inducmg 
 certain specific diseases are not unfrequently encountered. Among these 
 may be mentioned the bacillus of tetanus (Nicolaier and Eosenbach), of 
 anthrax (Frank), of mahgnant oedema (Koch and Gaffky), and of typhoid 
 fever (Eberth and Gaifky). The bacillus of malaria described by Klebs and 
 Tommasi-Crudeli should, perhaps, be included, although its pathogenic 
 significance is not now generally accepted. In like manner, the microbe 
 which Professor Domingos Freire, of Brazil, discovered in a burial-ground 
 near Eio Janeiro, and which he believed to be the cause of yellow fever, is 
 now stated on independent evidence to have no relation to that disease. 
 Sherrington has isolated a pneumococcus from laboratory dust which is 
 fatal to mice when inoculated subcutaneously, but whether it has any patho- 
 genic importance in relation to human beings is at present unknown. ^ 
 
 Cholera bacilli have not hitherto been found in the soil, but Frankel has 
 shown experimentally that they can grow and multiply there at various 
 depths. At a distance of about four feet from the surface their development 
 was constant and progressive throughout the year. Diarrhoea, again, is a 
 disease as to which, as the result of Ballard's researches, there is every reason 
 to suspect that a definite micro-organism is necessary for its appearance, and, 
 moreover, that such microbe has its normal habitat in the soil, although it 
 has not as yet been isolated. 
 
 GEOUND AIR 
 
 All soils contain a certain amount of air, the actual percentage depending 
 on the looseness or othervidse with which the constituent particles are packed 
 together. Many rocks, particularly the softer varieties, also contain air, only 
 the very densest forms being practically free from it. 
 
 This air, which may exist in loose sands to the extent of about 50 per 
 cent., or even more, consists in great part of carbon dioxide, while oxygen is 
 usually present in smaller quantity than in atmospheric air. This was 
 first pointed out by Boussingault and Levy, who in 1852 analysed air which 
 
 * This was a bacillus found in the dust of an upper room in the Hygienic Institute, 
 Kloster Strasse, Berlin, in March 1887. White mice inoculated with a fraction of a 
 drop of the pure cultures died invariably, generally in about forty-eight hours. Eats 
 inoculated with it generally, but not always, succumbed. Of ten guinea-pigs inoculated, 
 one only died. The bacillus in many respects resembled Friedlander's pneumococcus, 
 a point of distinction between them was, however, the more perfect anterobiosis of the 
 pneumococcus. Spores were not detected. 
 
318 HYGIENE 
 
 they had aspirated from the soil at a distance of 1^ feet from the surface, 
 with the result that its composition was found to be — 
 
 Oxygen 10-35 per cent, of volume 
 
 Carbon dioxide 9-74 „ ,, 
 
 Nitrogen 79-91 „ 
 
 Pettenkofer, next investigating the subject, confirmed the presence in the 
 ground air of an amount of carbon dioxide in excess of that in atmospheric 
 air, the amount increasing with the depth from which the air was drawn, 
 and being influenced, moreover, by the season of the year — the greatest 
 quantity at a given depth being found in autumn, and the least in spring. 
 He stated his opmion that this COo was due to the decomposition of organic 
 substances under the influence of atmospheric air, which had found an 
 entrance to the soil, and considered that the CO.2 of well-waters, and possibly 
 that contained in the atmosphere, were in part derived from it. 
 
 Fleck, in Dresden, and Fodor, in Buda-Pesth, independently arrived at 
 somewhat similar conclusions, and the former observer suggested that the 
 amount of carbon dioxide might afford an approximate means of estimating 
 the degree of pollution of the soil. This hypothesis, however, is contraverted 
 by Fodor and Eoller, who found that although the CO.3 was doubtless pro- 
 duced by the decomposition of organic substances, it did not afford so much 
 an index of the pollution as of the permeability of the soil ; a very polluted 
 soil, if at the same time very permeable, containing even a smaller amount 
 of CO2 than a soil less polluted if also less permeable. Lems and Cunning- 
 ham found that the COo in the ground air in the soil of a field near Calcutta 
 which they examined, increased with the rainfall and decreased with dry 
 weather, the amount also being greatest in the lower strata examined. In 
 point of fact, it appears certain that the ground air consists for the most part 
 of atmospheric air, which has penetrated into the pores of the earth, some 
 of the oxygen of such air having become converted into carbon dioxide. 
 Boussingault and Levy, however, found that a certam specimen of ground 
 air contained only 20*09 volumes per cent, of carbon dioxide + oxygen, and 
 they supposed, therefore, that a small part of the oxygen had united with 
 hydrogen obtained from organic substances in the soil to form water. 
 
 The oxygen of the air, then, on passing into the soil, enters into chemical 
 combination with carbon derived from various animal and vegetable sources, 
 and thus becomes replaced in some measure by an equal volume of CO2. 
 There must, however, be other influences also at work, since this statement 
 is not invariably borne out, the percentage amount of oxygen and COg 
 together in the ground air being sometimes slightly higher and sometimes 
 lower than in the atmosphere, a possible explanation of which may be found 
 in the union of a certain portion of the oxygen with hydrogen to form water, 
 and with nitrogenous organic bodies to form nitrates. On the other hand, 
 the CO.2 which is formed may unite to some extent with the water in the 
 soil, and also with alkalies, such as ammonia, and the basic earthy salts to 
 form bicarbonates. 
 
 The suggestion has been made that the soil may, perhaps, absorb and 
 condense gases after the manner of spongy platinum, and Eoller cites some 
 experiments which would appear to support this view, as on driving air 
 through garden soil he found rather less CO2 in the issuing than in the in- 
 going soil, whereas with dry sand the air passed through unchanged. Fodor 
 explains this by inferring that although air passed through moist and polluted 
 soil which had first been heated and then cooled does lose some of its CO2, 
 the loss is due to the water in the soil, which, losing its CO2 when heated, 
 takes it up again from the air passed through the soil. 
 
THE INFLUENCE OF SOIL ON HEALTH 319 
 
 The carbon dioxide in the ground air may be greater in amount than 
 would correspond to the oxygen absorbed from the atmosphere. In such a 
 case the excess of CO2 is due to the vital action of putrefactive organisms, 
 which may not only use the oxygen of the atmosphere, but also are capable 
 of abstracting the oxygen of organic substances and also that of tlie nitrates 
 in the soil. Thus, if a flask containing water with organic substances in 
 solution, such as Cohn's fluid, after a short exposure to the air, be her- 
 metically sealed up at the neck and then set aside for some days in a warm 
 place, it will be found that if, after such a lapse of time, the gases in the 
 flask be collected, their volume may be from 35 to 40 per cent, above the 
 volume of the air in the flask before it was sealed up, the contained gases 
 consisting of carbon dioxide and nitrogen in about equal parts, while oxygen 
 will be conspicuous by its absence. In this connection it may be noted that, 
 as stated above, even inorganic substances are reduced in the process of 
 putrefaction, nitrates, according to Pasteur and Cohn, becoming converted 
 into nitrites, and even into ammonia. Thus Schlosing, on drawing air 
 containing different amounts of oxygen through earth containing putrefactive 
 organisms, invariably found that carbonic acid was formed, while the amount 
 of nitric acid in the soil was decreased. 
 
 Here we find an explanation of the fact that an increased amount of gas 
 is found in the lower layers of the earth, particularly in autumn, when these 
 layers are warmest, and when, therefore, the vitality of organisms concerned 
 in decomposition processes would be most favoured. This was particularly 
 noticed by Nicholas, who found an increase of gas in the air of his artificial 
 earth in summer, and a decrease in winter ; the volume of oxygen + carbon 
 dioxide in this earth at a depth of fourteen inches having been in one series 
 of experiments as follows : — 
 
 On June 21 26-2 per cent. 
 
 On July 26 26-7 
 
 On October 16 21-6 
 
 On November 10 19-7 „ 
 
 Not only, then, does oxidation take place in the soil, but putrefaction also, 
 as is seen from the fact that a relative increase in the amount of oxygen and 
 carbon dioxide may temporarily occur. The more polluted the soil, and the 
 more impermeable to air — whether originally so, as when it is largely com- 
 posed of clay, or whether rendered so artificially by the pores of the upper 
 layers becoming sealed up by rain — the more will putrefaction go on ; whereas 
 under opposite conditions oxidation alone will take place, putrefactive changes 
 being wholly in abeyance. The presence of ammonia in the ground air indi- 
 cates that putrefaction is going on in it, and since usually about four times 
 as much ammonia can be obtained from the soil at a depth of four metres 
 as at about a quarter of that depth, it would appear that putrefaction occurs 
 more especially in the deeper layers, where there is practically no free oxygen, 
 but where anaerobic bacteria are known to thrive. There is, therefore, a 
 greater tendency to putrefactive changes in the soil near the ground water 
 than in the more superficial layers. (Fodor.) 
 
 The nitrogenous organic substances in the soil become in course of time 
 converted into nitrates, which are washed into the deeper layers by the rain, 
 becoming there reduced under the influence of bacteria into ammonia. This 
 unites with carbonic acid there present, and may again pass up to the super- 
 ficial layers, in solution in rising ground water, where it is seized upon by 
 plants. For this reason it will be seen that, although ammonia may be found 
 in the soil, an estimation of the actual amount present cannot be taken as 
 an index of the activity of putrefactive changes which are going on. 
 
320 HYGIENE 
 
 The nitrogen present in soil is equal to that -wliicli would normally be 
 present in the amount of atmospheric air which had penetrated the earth. 
 There has, however, been considerable discussion as to whether any of it 
 becomes absorbed or not, Deherain maintaining that a portion of it does 
 thus disappear, while, on the other hand, Boussingault, Schlosing, and others 
 state that it is impossible to iind evidence of such absorption. Occasionally 
 sulphuretted hydrogen is found in ground air, particularly if the soil be moist ; 
 it appears to be derived from the sulphates present in the hard water Avith 
 wliich the soil is charged. Marsh gas or carburetted hydrogen also may 
 occm' as a result of the decomposition of certain organic substances ; it may be 
 obtained from putrid mud, and, as in the case of carbonic acid and ammonia, is 
 found in greater amounts in the deeper layers. This increase of it at the greater 
 depths is mainly due to greater difficulty of ventilation ; indeed this factor may 
 be even more important tlian the pollution of the soil, as an instance of which 
 may be quoted Fodor's observation that at one place he found much more 
 carbonic acid at four metres than at a depth of two metres only, although 
 the organic carbon and organic nitrogen were in greater amount at the former 
 point. As a rule, however, the relative amounts of carbon dioxide in samples 
 of ground air taken from soils which have practically the same degree of 
 permeability indicate the relative extent of impurity of these soils ; when, 
 however, the permeabihty varies, the rule does not, of course, apply. 
 
 The actual amount of carbon dioxide in soils varies, according to Boussin- 
 gault's experiments, from 2*4 per 1,000 volumes to 9-74 in soils which have 
 been recently manured. In alluvial ground Nichols found from 1*49 to 2'26 
 volumes per 1,000 in air, drawn from a depth of from 3f to 5^ feet. Fodor 
 gives as the results of thirteen observations at a depth of one metre, from 8*99 
 to 10'39, and at a depth of four metres (from eleven observations) from 26*31 to 
 54-45 CO2, while Pettenkofer and Fleck have found it rise as high as 80 per 
 1,000 volumes in gravelly soils at depths of from five to thirteen feet. 
 
 Annual and Seasonal Vaeiations op CO2 in Ground Aik 
 
 It might reasonably be expected that in spring more CO2 might be found 
 for a short time in the superficial layers than m those lower down, owing 
 to the fact that these upper layers become somewhat suddenly warmed. As 
 a matter of fact, both Pettenkofer and Fodor have found that such is the 
 case, the ground air in spring having for a longer or shorter period more 
 CO2 at a depth of one metre than the air obtained from a depth of two metres. 
 In autumn, on the contrary, the CO2 in the superficial layers sinks rapidly, 
 and curves representing the respective amounts in superficial and deep layers 
 become most widely separated. 
 
 By taking the average of a large number of observations, it appears that 
 the amount of CO2 in the soil rises in a uniform manner till the height of 
 summer, and then sinks as the temperature subsides, and with the exception 
 mentioned above, the variations at different depths show a certain degree of 
 parallelism. (Plate II.) Owing, however, to the alternation of warming and 
 cooling of the soil, the CO2 maxima and minima do not occur quite simulta- 
 neously in all the layers although the greater amount is always found at the 
 greater depth, as is shown in the following table compiled by Fodor at Buda- 
 Pesth, as the average of a large number of observations extendiag over a period 
 of three years. 
 
 The variations in the amount of COo in the soil ia different years and at 
 different seasons depends on the amount of decomposition which is going on ; 
 this in turn undergoing fluctuations according to the amount of the rainfall 
 
t, Tre$-.tise on Hygiene J PI. 11. 
 
 VoLl, 
 
 The- Soil oriy Ujs Ilelaiwru to Doseouse^. 
 
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THE INFLUENCE OF SOIL ON HEALTH 
 
 521 
 
 and the prevailing temperature, the effect of the latter being very marked. Of 
 course this concurrence is most marked in the superficial layers in which the 
 variation is largest, and in which the soil is most polluted, and in which con- 
 sequently the increase of warmth can effect the largest relative CO.^ produc- 
 tion. In the deeper layers the CO2, as also the temperature, usually reaches 
 its maximum amount about a week later than in the superficial layers. 
 
 
 Amounts of CO^ in the ground 
 
 
 Amounts of 00^ in the ground 
 
 
 air as the mean of observations 
 
 
 air as the mean of observations 
 
 ~ 
 
 for three years 
 
 
 for three years 
 
 1 metre 
 
 2 metres 
 
 4 metres 
 
 1 metre 
 
 2 metres 
 
 4 metres 
 
 January- 
 
 6-5 
 
 12-6 
 
 25-0 
 
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 15-8 
 
 228 
 
 359 
 
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 6-8 
 
 12-2 
 
 24-8 
 
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 12-8 
 
 20-7 
 
 32-6 
 
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 70 
 
 11-8 
 
 24-7 
 
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 10-9 
 
 19-3 
 
 31-4 
 
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 9-9 
 
 14-9 
 
 25-2 
 
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 15-0 
 
 29-4 
 
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 11-5 
 
 16-1 
 
 27-2 
 
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 8-4 
 
 13-8 
 
 26-5 
 
 June . 
 
 14-5 
 
 21-5 
 
 29-2 
 
 December . 
 
 8-1 
 
 12-6 
 
 25-8 
 
 Rainfall has also a marked effect upon the amount of CO2 in the soil, an 
 increase of rainfall being quickly attended by an increase of CO2, while in dry 
 weather the amount of CO2 becomes reduced. Such an increase after rain is 
 due to the blocking up of the pores of the superficial layers and a consequent 
 accumulation of CO2 in the deeper portions of the soil, and is almost 
 immediately followed by a fall, the CO2 being absorbed by the wetted soil. 
 This general coincidence between a period of rainfall and a period of eleva- 
 tion in amount of carbonic acid is, however, much closer and more marked 
 in reference to the carbonic acid in the upper than to that in the lower layers 
 of soil, for, as Lewis and Cunningham found in the course of their investiga- 
 tions at Calcutta, the amount of carbonic acid in the latter continues high 
 long after the cessation of the rains, and shows no immediate rise corre- 
 sponding with their commencement in the following season. 
 
 Daily variations also occur to a certain extent, but they do not follow any 
 very definite rule. They depend not so much on variations in decomposition 
 processes as on wind, rain, and changes of atmospheric pressure. Wind, 
 according to Pettenkofer and Fodor, sucks out the air from the soil, and so 
 reduces the carbonic acid in it ; the latter observer having found a decided 
 decrease in its amount on 77 out of 111 very windy days. Under certain 
 conditions, however, an opposite result may become apparent from the action 
 of the wind forcing air into strata opposed to its path. Lewis and Cunning- 
 ham found, however, that the velocity of the wind did not appear to exert 
 any very distinct influence on the amount of carbonic acid in the soil as a 
 rule, although, after an extreme and continued elevation of the wind during 
 a couple of months, they found a sudden depression in the amount of carbonic 
 acid in the upper layer of the soil in one locality, while there was no corre- 
 sponding depression in the upper layer of the soil of a second station which 
 happened to be much more shaded than the first. After a long continuance 
 of still weather, they also noted a marked elevation in amount of carbonic 
 acid at both places, probably due to the diminished ventilation of the soil 
 which preceded it. 
 
 Changes in atmospheric press2ire do not exert any very great influence on 
 the amount of carbonic acid, although it would appear that on days on which 
 the barometric pressure is very much below that on preceding days, the 
 mean amount of carbonic acid in the soil at a depth of about three feet from 
 the surface will be found to have risen, the probable explanation being that 
 owing to the ground air escaping on the days of lozu pressure the ground air 
 
 VOL. I. T 
 
^322 HYGIENE 
 
 from the deeper layers, which is more heavily charged with CO2, rises into the 
 more superficial layers. "With an increase of atmospheric pressure, on the 
 other hand, the carbonic acid shows no marked tendency either to an increase 
 or decrease in amount. 
 
 CUKKENTS OF GeOUND AiR 
 
 From what has already been stated with regard to the fluctuations in the 
 amount of carbon dioxide hi the soil, it will be evident that the subterranean 
 atmosphere which exists in the soil is in continual movement. This is 
 mainly due to variations in the temperature of the eai'th and of the atmo- 
 sphere which do not usually occur simultaneously, the variations of earth 
 temperature for the most part following on similar variations in the tempera- 
 ture of the air, it being extremely rare for both eartb and air to show the 
 same temperatui-e, at any rate for more than a very short time (Plate III.). 
 Either the soil or the air will be the colder or the warmer, and consequently 
 the ground air is continually moving, either passing from the deeper to the 
 more superficial portions of the soil, or vice versd. Naturally the greatest 
 range of movement will occur when the soil and air are most difi'erent in 
 temperature. In autumn and winter the soil is the warmer, and therefore the 
 air present in it escapes into the atmosphere, the colder atmospheric air 
 entering into the pores of the soil — this effect being more marked the drier the 
 soil. For the same reason the ground air will pass up to places where the 
 surface is elevated, being displaced by the atmospheric air which will enter 
 the soil in low-lying situations. 
 
 In spring and summer, on the contrary, the ground air is colder and 
 denser than the atmosphere, hence it will tend to pass down into the deeper 
 layers of the soil. On a cool day following on a hot one the ground air 
 escapes into the atmosphere, while on warm days it remains stagnant in the 
 soil. At night, too, the warmer ground air will escape into the atmosphere. 
 Beneath buildings, such movements of the ground air may be very active, 
 particularly in the case of houses that are artificially warmed, the air which 
 then passes up from below being often drawn from considerable depths, so 
 that, in the case of houses which have been built upon ' made soils ' especially, 
 much unhealthiness may result from the aspiration of foul air from the 
 impure soil beneath, unless the precaution be taken of covering the site with 
 an impermeable layer of asphalte or concrete, or if necessary by raising the 
 house from the surface of the ground on arches. Similarly, lealdng cesspools 
 and drains may contaminate the soil, the air from which, passing up into 
 houses, may most injuriously affect the health of the inhabitants. 
 
 Kain sinking into the soil will drive the ground air to a deeper level, and 
 at the same time will cause it to escape at places where the earth has not 
 been wetted. Variations of level of the ground water also will necessarily 
 cause corresponding movements of the ground air which lies above it, the 
 latter being slowly expelled from the surface of the earth as the ground 
 water rises and occupies the spaces between the particles of the soil ; air 
 being again, sucked in as the ground water falls. Other factors concerned, 
 such as alterations of barometric pressure and the action of wind, have aheady 
 been considered in connection with variations in the amount of carbon dioxide 
 in the soil. 
 
 The air which fills the soil to a depth of from five to ten metres (15 
 to 30 feet) and makes up almost one-third of its volume, can, even if it move 
 but slowly, rise therefrom in the course of a single night so as to constitute, 
 with its contained moist foul gases, a considerable portion of the atmosphere 
 of our dwellings, courts, and streets. 
 
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THE INFLUENCE OF SOIL ON HEALTH 323 
 
 Estimation of Amount of Am in Soil 
 In order to estimate the amount of air contained in loose soils, Pettenkofer 
 ■advises the following procedure : — A sample of the soil to be examined is 
 dried at a temperature of 100° C. (212° F.) and then powdered, care being 
 taken to crush it as little as possible. Two burettes, connected together at their 
 lower extremities with an india-rubber tube provided with a clamp, are supported 
 side by side on an appropriate stand ; into one is put a portion of the dried and 
 powdered soil, while the other is filled with distilled water. The first burette 
 should now be gently tapped to expel the air as much as possible from the inter- 
 stices of the soil, and the clamp opened, when the water from the second burette 
 will gradually rise up through the soil until it appears as a thin film above the 
 surface. As soon as this occurs, the clamp is again closed and the amount 
 of water which has left the second burette is to be read off. The percentage 
 amount of air in the soil is obtained as follows : — 
 
 Cubic centimetres of water used x 100 _ ^centage of air. 
 Cubic centimetres oi dry soil 
 
 so that if 25 c.c. of soil were placed in the burette and 7 c.e. of water were 
 
 7 X 100 
 
 used to displace the air in the soil, then — — = percentage of air. 
 
 25 
 
 If a piece of rock is to be examined instead of loose soil, an estimation 
 can be made in a somewhat similar manner, provided the rock is fairly porous, 
 by determining the amount of water which it will absorb. This can be fairly 
 accurately gauged by first weighing the rock in the dry state {x), then weigh- 
 ing it in water {y), and finally removing it from the water, and again weighing 
 it while saturated with moisture [z). The calculation will then be as follows : — 
 
 (z-x) 100 . t ■ 
 
 i '- = percentage oi air. 
 
 x—y 
 
 Estimation of Amount of Caebon Dioxide in Geound Aie 
 For this purpose Lewis and Cunningham, who investigated the amount of 
 carbonic acid in the soil at depths of 3 and 6 feet respectively, proceeded in 
 the following manner. Two leaden tubes were procured, at one end of each 
 of which a hollow perforated bulb was soldered. A pit was dug in the soil 
 at a spot where it was perfectly free from surface pollution and where it had 
 probably not been disturbed for many years. One of these tubes was passed 
 through the bottom of an ordinary flower-pot, inverted and perforated in 
 numerous places. Below and surrounding this pot fragments of earthenware 
 were arranged so as to keep the earth from plugging the orifices in the bul- 
 bous extremity of the leaden tube. The pit was now filled up to within three 
 feet of the surface and the other tube introduced and similarly protected from 
 being plagged by the fine soil ; the earth was then heaped up and well beaten 
 down, until it reached the level of the surface. Observations were not made 
 until a considerable period had elapsed, so as to allow the soil to regain its 
 ordinary condition. 
 
 Attached to the aspirator — intervening between it and the pipe leading 
 into the soil — were the usual appliances for estimating the amount of carbon 
 dioxide by the baryta process, which is fully explained in another section. 
 Briefly described, the method consists in causing the air under examination 
 to pass through a flask containing a solution of baryta of known alkahnity, 
 and subsequently ascertaining, by means of a solution of oxalic acid, how 
 much of the alkalinity has disappeared after the passage through it of the air 
 containing carbonic acid — turmeric paper being employed in preference to 
 litmus for ascertaining the precise stage at which the solution becomes neutral. 
 
 y2 
 
824 HYGIENE 
 
 WATER IN THE SOIL 
 Soil Moisture 
 
 To Pettenkofer is due the credit of having been the first to dh-ect attention^ 
 by his important investigations, to the subject of the soil water in its relation 
 to disease. In this connection it is necessary to distmguish between the 
 amount of water mixed with air which is present in the interstices of the soil, 
 known as moisture, and the continuous subterranean lake or sheet of water 
 found in most soils at varying depths from the surface, known as ground water. 
 Pettenkofer defines this ground water as that condition in which all inter- 
 stices are filled with water, so that, except in so far as its particles are sepa- 
 rated by solid portions of soil, there is a continuity of water. 
 
 The amount oi moisture in the soil depends on its power of absorbing and 
 retaming water, on the nature of the subsoil, the configuration of the ground, 
 and the amount of water supplied by the rainfall or derived from the ground 
 water below. It would appear that wetting of the soil, when due to a rise 
 of ground water, will conduce to active putrefaction in the deep layers, while, 
 the superficial layers remaining permeable, the products of decomposition can 
 readily make their way to the surface of the earth, whereas when the wetting 
 of the soil is due to the rainfall the conditions will be different. 
 
 The nature of the soil will influence considerably the amount of moisture 
 which it will take up, although there is no soil which is not capable of ab- 
 sorbmg a certain amount. Some porous soils, such as loose sands and 
 gravels, sandstones, and chalk, are capable of taking up very large quantities ; 
 a loose sand being said to be capable of holding as much as two gallons of 
 water in a cubic foot, while ordinary sandstone may hold one gallon. Dried 
 quartz sand has been shown by Pfaff to have the power of retaining about 
 20 per cent, of water, although under natural conditions the amount absorbed 
 would doubtless not be so great. Humus may take up as much as from 40 
 to GO per cent, and retain it strongly, while chalk will take up about 15 per 
 cent., and moderately loose clay 20 per cent. Even the most impermeable 
 rocks, such as the granites, the metamorphic rocks, dense clays and hard 
 limestones, will contain a certain amount of water varying in the case of 
 the driest granites from ^ per cent, to 4 per cent., or an average of about 
 three gallons in a cubic yard, between which and the amount capable of 
 being taken up by the most permeable soils all gradations are found. 
 
 Although the soil moisture is in great part regulated by the rainfall, the 
 amount actually absorbed will depend on a variety of circumstances, such as 
 the amount of evaporation, which will naturally be greater in summer than 
 in winter, the rapidity of the rainfall— a large amount often running off along 
 the surface of the ground if the downfall be severe at any one time — and the 
 configuration of the land. In the loosest sands more than 90 per cent, of 
 the total rainfall may penetrate the soil, while in the case of the chalk it has 
 been calculated at 42 per cent, and with sandstone at 25 per cent, on the 
 average, the remamder either evaporating or draining away along the surface. 
 As has been said, the ground water also influences the soil-moisture by its 
 variations in rise and fall, by evaporation through the upper stratum of the 
 soil, and by capillary attraction, so that the surface soil is in these various 
 ways kept more or less damp in all parts of the world. According to Fodor, 
 the curve of moisture in the more superficial layers of the soil runs closely 
 parallel with the curve representing the amount of rainfall. The curve of 
 moisture in the deeper layers, on the other hand, runs closely parallel with 
 
THE INFLUENCE OF SOIL ON HEALTH 325 
 
 the curve representing the varying levels of the ground water, both attaining 
 their maximum in summer and early autumn. 
 
 For determining the amount of moisture in soil, a boring is taken and 
 weighed ; it is then dried at a temperature of 110° C. and weighed again, when 
 the difference of the two observations will represent the amount sought to be 
 ascertained, which may conveniently be expressed as a percentage. The amount 
 of moisture which it is capable of taking up may be determined by placing 
 the previously dried soil under a bell -jar, the contained air being saturated 
 with moisture. 
 
 In a series of observations on the amount of moisture held by soil at varying 
 depths, Fodor found that not only did the amount decrease with the depth 
 from the surface, but that the amount varied a great deal at all depths in similar 
 kinds of soil, even when examined at the same time. He considers that these 
 differences are due to the amount of organic substances in the soil, such 
 organic substances having the effect of raising the capacity of the soil for 
 absorbing water ; this theory being borne out by the fact that the amount of 
 moisture in the soil varies directly as the amount of organic substances present. 
 The amount of moisture falls off rapidly as deeper layers are penetrated, and 
 this appears to correspond also with the varying amount of organic substances 
 in the soil, the amount of which diminishes rapidly as we get further from 
 the surface. 
 
 The amount of moisture not only varies from year to year, but from season 
 to season, and even from month to month, the amount generally increasing 
 in spring, reaching its maximum in May, and then sinking during the summer 
 till late in the autumn. Here again differences are noted according to the 
 depth, the soil at from three to six feet from the surface being most moist in 
 spring, the amount gradually diminishing towards autumn ; while at a depth 
 of from nine to twelve feet the soil is most moist in summer and least so in 
 autumn.^ 
 
 At still shorter intervals of time the variations in the amount of moisture 
 may be very large. At from three to six feet in depth the amount of moisture 
 usually remains constant, since, in fact, the soil at these depths is generally 
 saturated. Below these levels the sinking rain-water will probably first 
 saturate the soil, and then running off again, will in turn leave it relatively 
 dry. It is, however, the variations in the layers down to about six feet below 
 the surface especially that are of most interest practically, since these upper 
 layers will naturally be the most polluted, and because, therefore, processes 
 which influence health probably go on in them to a much greater extent than 
 in the layers below. The minimum moisture found at Buda-Pesth at one 
 yard from the surface was 5'9 per cent, or 59 grammes of water per 1,000 
 grammes of soil, while at four yards it was 3"2 per cent. ; but since decom- 
 position continues when there is only 2 per cent, of moisture present, and 
 is very active when the amoimt reaches 4 per cent., it is obvious that, as 
 far as moisture is concerned, oxidation and putrefaction are particularly 
 favoured at the former level, while they are less so at greater depths. 
 
 Ground or Subsoil Water 
 
 A continuous sheet of water, termed ground water, is found below the 
 surface of the soil, at depths which vary very considerably in different locahties, 
 as occasionally it may reach to within a few inches of the surface, while in 
 other cases it may only be met with at a hundred or more feet below it. This 
 difference in level will depend on the permeability of the soil, on the nature and 
 inclination of the strata below the surface, whether loose or compact, and on 
 
 ' These statements refer more particularly to Buda-Pesth, where Fodor's experiments 
 were carried out. 
 
326 HYGIENE 
 
 the ease or the reverse with which the water can flow away to some outlet iix 
 sprmgs, rivers, or the sea. The water is in constant movement in its en- 
 deavour to reach such outlets, and the variations in the level of the ground 
 water caused by such flow is best studied by taking measurements of the level 
 of water in wells, as has been done in a most exhaustive manner by Petten- 
 kofer, Fodor, Baldwin Latham, and others, who have insisted strongly on the 
 importance of such variation of level of the ground water as constituting a 
 weighty factor in the etiology of certain diseases, such as cholera and enteric 
 fever. 
 
 Fodor found that at Buda-Pesth such variations were regulated over the 
 greater part of the city by the varying level of the Danube, the greatest 
 fluctuations being found in the wells nearest the river ; while, on the other 
 hand, the greater the distance from the Danube the smaller were the varia- 
 tions of the water level, until at the outer limits of the city they almost 
 entirely disappeared. 
 
 Although the level of the ground water is thus constantly changmg, the 
 difl'erence between its highest and lowest levels is usually not more than a 
 few feet, while in some instances the range of movement may be only a few 
 inches either way. At Munich a difference of ten feet has been noticed, and 
 in India it is often much more than this, a range of i'Z^ ft. having been re- 
 corded. Fodor noted seasonal variations of the ground-water level which^ 
 however, agreed very closely with variations in the level of the Danube ; the 
 ground water and that of the river rising and falling, and reaching their 
 maximum and minimum at the same time. 
 
 The rise was noticeable at the beguming of July and continued through 
 August, the highest level in each of three years occurring about the middle 
 of smmner, and the lowest at the end of winter and beginning of spring ; so 
 that the interesting fact was brought out that the ground water is highest 
 when the rainfall is smallest. This was particularly noticeable in May 1887, 
 when, after an exceptionally heavy rainfall, no marked influence on the varia- 
 tion of level of the ground water in any one of the wells could be detected : the 
 reason being that the extent of the subsoil water at Buda-Pesth is affected to a 
 much greater extent by variations in the level of the river than by merely local 
 rainfall. It must not, however, be supposed that the rainfall never affects 
 the ground water, as in some instances it undoubtedly does so ; but even then 
 the effect may not be visible until some considerable time afterwards, extend- 
 ing to weeks or even months. On the other hand, in low-lyuig situations, 
 such as in plains at the foot of hills, the level may be raised by rainfalls 
 occurring at far distant spots. The level will also be raised by any obstruc- 
 tion at the outfall, such as may be caused by the silting up of a watercourse, 
 or the backward pressure of the sea, and, on the other hand, it will be lowered 
 by any removal of obstruction, such as may be secured by sldlful drainage. 
 The immense distance at which pressure may be exerted on the subsoil water 
 is shown by the fact that the Danube at Buda-Pesth was found by Fodor to in- 
 fluence the level of the water ha a well at a distance of 2,700 feet from that river. 
 De Chaumont also instances a place on the Hamble Eiver in Hampshire, where 
 the tide was found to affect the water of a well at a distance of 2,240 feet, the 
 well itself being 83 feet deep and 140 feet above mean water level. Similarly, 
 the water of a well was affected by the pressure of the water of the Rhine 
 at a distance of 1,670 feet. 
 
 The ground water is constantly moving in a horizontal direction, usually 
 flowing towards the nearest watercourse or the sea ; the rate of movement 
 depending on the inclination of underlying impervious strata, and the ease, 
 or the reverse, with which it can eventually escape, so that it varies greatly 
 
THE INFLUENCE OF SOIL ON HEALTH 327 
 
 in different places. Its rate of movement is also influenced by the roots of 
 trees, as when trees are removed it runs away much more rapidly. As the 
 mean of a large number of measurements as to the time when a rise in the 
 Danube was followed by a rise of water in the wells at Buda-Pesth, Fodor 
 found that the mean rate of movement of the ground water was 53 metres, 
 or 174 feet, in twenty-four hours, with a maximum of 66 metres, or 215 feet, in 
 the same length of time. In Munich, Pettenkofer reckons the rate of flow as 
 fifteen feet daily, while high water in the Elbe is stated to move the adjacent 
 ground water at the rate of seven or eight feet daily. 
 
 The height to which the ground water extends is measured by noting the 
 level of water in wells in the locality in which the investigation is to be 
 carried out. For this purpose, Pettenkofer recommends that a rod or rope, 
 to which a number of small cups are fixed at equal distances, should be 
 lowered into the well. On drawing them up again, the highest one which 
 contains water will obviously denote fairly accurately the height at which 
 water stands in that particular well, and if the length of rod which has been 
 lowered is noted, the distance from the surface to the water level will be 
 found. To arrive at any correct estimate of the true ground- water level, a 
 large number of experiments must be carried out simultaneously in the wells 
 over a considerable area, so as to obviate sources of error arising from local 
 conditions. To be of any real use, such observations should be made as 
 frequently as possible ; those from which Fodor derives his conclusions 
 having been made every week in a large number of adjoining places, the series 
 extending over a period of several years. 
 
 Another method, given by Pettenkofer for the determination of the level 
 of well water, consists in tlie use of a large float, suspended by a chain passing 
 over a pulley, which is connected with a counter-balance, having an indicator 
 attached to it, which marks the height on a fixed scale which has been pre- 
 viously experimentally graduated for the length of the chain. 
 
 THE TEMPEEATUEE OF THE SOIL 
 
 Different soils vary very considerably in the extent to which they are 
 capable of absorbing heat, this depending mainly on the looseness or density 
 of the particles and on the colour of the soil ; but, in most places, variations 
 of temperature dependent on that of the atmosphere may be found to extend 
 in this chmate to a depth of about sixty feet, and even deeper in other por- 
 tions of the globe. These variations of temperature at all depths do not, 
 however, follow directly on similar fluctuations in the atmospheric tempera- 
 ture, such changes being delayed longer and longer in the lower layers of the 
 soil, so that it is only at the surface that there is any immediate correspon- 
 dence between the temperatures of air and soil. This point is well brought 
 out by Fodor, who found that the warming and cooling of the deeper layers 
 was much slower than the warming and cooling of the atmosphere, or of 
 the superficial layers of the soil ; his observations at Buda-Pesth giving 
 the following results : — 
 
 The average maximum temperature at a de]Dth of ^ to 1 metre was found in August. 
 ,, „ „ „ 2 metres was found in September 
 
 (and August). 
 „ „ „ „ 4 metres was found in October (and 
 
 September). 
 The average minimum temperature at a depth of ^ to 1 metre was generally in Feb- 
 ruary and January. 
 „ „ „ „ 2 metres was found in April; in 
 
 some cases in March. 
 
328 HYGIENE 
 
 He also found that the greatest range of temperature was noted 
 in the superficial layers ; at half a metre below the surface there was a 
 variation of even 20° C. below the monthly means of one and the same 
 year, but at a depth of four metres there was a variation of 5?,-° only, and 
 in some places of hardly more than 8°. The temperature at this depth 
 was very uniform, rising and falling very slowly, seldom varying as much 
 as half a degree in the com-se of ten days. It changed most rapidly 
 in the spring, and when it reached either its maximum or minimum it 
 usually remained constant for ten, twenty, or even more days, rising to the 
 maximum and falling to the minimum at an average rate of from ^'„-° to 
 1-,)° C. every ten days. In the upper layers, however, the variations occur 
 more rapidly. At a depth of two metres there may be a change of 2^° C. 
 in ten days, while the variations are still greater at a depth of one metre or 
 less. 
 
 Different soils vary considerably in the rapidity with which they are in- 
 fluenced by the atmospheric temperature ; that is, they difter in the rate at 
 which a rise or fall of temperature takes place in them. The temperature 
 of the surface soil will depend greatly on whether the sun shines directly on 
 it, as in this case a higher temperature will be recorded than that of the 
 atmosphere above, and in this way the atmosphere just above the surface may 
 receive much of its heat from the soil. When, on the other hand, the sun's 
 rays no longer fall on the soil, it readily loses heat, and may, at night, possess 
 a lower temperature than that of the air. When this takes place, the moisture 
 contained in the air condenses upon the surface in the form of dew. 
 
 The soil temperature below the surface follows even great variations of 
 air temperature but sloAvly, for after a succession of warm or cold days, it 
 needs two or three days for the temperature, at a depth of half a metre, to 
 begin to accommodate itself to that of the atmosphere. Indeed, a change of 
 Ixom twelve to fourteen, or even more, degrees in the atmospheric tempera- 
 ture from one day to the next may not be followed by a change of even 
 1° G. in the temperature of the soil half a metre below the surface. At a 
 depth of one metre the changes are still smaller, while at two or four metres' 
 depth the increasing or decreasing soil temperature moves almost in a straight 
 line, although the record of the air temperature may show a zigzag curve. 
 
 These statements receive confirmation from the observations of Lewis 
 and Cunningham at Calcutta, who found that fluctuations in temperature in 
 the upper layers of the soil follow those of the atmosphere very regularly, 
 except during the recurrence of rain, when this correspondence was not con- 
 stant. Their observations were taken at depths of three feet and six feet 
 respectively. The fluctuations in the temperature of the lower layer were 
 much less marked and sudden than in the more superficial, the line of eleva- 
 tion and depression following a long gentle curve. They found also that the 
 maxima of temperature in the two layers approached more closely than the 
 minima, a point in which the relations of temperature corresponded with 
 those of carbonic acid. During cold weather the temperature of the lower 
 layers considerably exceeded that of the upper one, while this in turn was 
 higher than that of the atmosphere, these relations being exactly reversed 
 in hot weather, when the temperature of the upper layer was the highest, 
 that of the deeper layer of the soil the lowest. 
 
 Different geological formations vary very much in their power of absorbing 
 and conducting heat, and the radiating power of the soil, which is not neces- 
 sarily equal to its power of absorption, will depend somewhat on the colour 
 of the soil and also on the kind and thickness of the vegetation. 
 
 That the temperature of the soil should depend to a certain extent on its 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 329 
 
 colour, follows from the well-known fact that dark substances possess the 
 greatest power of absorbing heat rays, as may be shown by the oft-quoted 
 experiment of placing two pieces of paper, the one white and the other 
 black, on the surface of snow when the sun is shining on it, when it will be 
 found that the snow melts more rapidly under the black paper than beneath 
 the white piece. 
 
 In like manner, the darker the soil, the more rapidly does it absorb beat 
 from the sun, very light-coloured soils, such as those containing much chalk, 
 heating but very slowly. Seeing that the colour of the darkest soils is for 
 the most part due to the products of decomposition of organic substances, it 
 follows that the warmest soils will be those which are richest in humus. 
 This result will also be increased to a certain degree where decomposition pro- 
 cesses are going on in the soil because of the heat thus produced, while also, 
 since on a warmer soil vegetation will be more luxuriant and growth proceed 
 at a greater rate than elsewhere, an additional appreciable amount of heat 
 will result, small though it may be ; it having been proved by numerous 
 observers that the growth of plants is always accompanied by a rise of tem- 
 perature, which, again, is related to the rapidity of their vital processes. 
 
 The following table, condensed by Lloyd from a much fuller one com- 
 piled by Liebenberg, of Halle, shows both the rapidity with which heat is 
 gained by various kinds of soil and also the rate at which it penetrates 
 
 beneath the surface : — 
 
 Gain of Heat by Soils 
 
 
 Original 
 temp. 
 
 After 
 
 1 hour 
 
 After 1 hour 
 
 After 2 hours 
 
 
 
 
 
 
 
 
 
 
 2 cm. 
 
 5 cm. 
 
 2 cm. 
 
 5 cm. 
 
 2 cm. 
 
 5 cm. 
 
 Lime sand 
 
 21° C. 
 
 29° C. 
 
 27-5° C. 
 
 32° C. 
 
 31-5° C. 
 
 36-5° C. 
 
 37° C. 
 
 Tertiary clay . 
 
 21 
 
 300 
 
 27-5 
 
 33-0 
 
 30-0 
 
 36-3 
 
 35-0 
 
 Tertiary sand . 
 
 21 
 
 30-0 
 
 28-0 
 
 33-5 
 
 32-5 
 
 37-5 
 
 36-5 
 
 Marl . 
 
 21 
 
 31-0 
 
 28-5 
 
 34-5 
 
 32-5 
 
 39-0 
 
 37-5 
 
 Meadow loam . 
 
 21 
 
 32-0 
 
 27-5 
 
 37-0 
 
 36-0 
 
 40-5 
 
 38-5 
 
 Eich loam 
 
 21 
 
 32-5 
 
 29-0 
 
 36-0 
 
 34-0 
 
 41-5 
 
 39-5 
 
 Basalt soil 
 
 21 
 
 33-0 
 
 28-5 
 
 35-0 
 
 33-0 
 
 42-0 
 
 38-0 
 
 Water 
 
 21 
 
 26-0 
 
 26-0 
 
 29-5 
 
 29-5 
 
 31-0 
 
 31-0 
 
 This table shows not only that sand becomes warmed throughout more 
 rapidly than clay, but also, as stated above, that the richer a soil is in organic 
 matter, the greater the power it possesses of absorbing heat. It further shows 
 that the temperature of water increases but slowly, which probably accounts 
 tor the fact that soils containing much water are colder than those which are 
 comparatively dry ; and indeed it has been established by observation that the 
 damper the soil, the slower it is to become warm, which accounts for the 
 •differing behaviour, as shown in the table, between sandy soils, which are dry 
 and warm, and clay, which retains a large amount of moisture. Not only do 
 clay soils warm slowly, but they also rapidly lose their heat, whereas sandy 
 soils on the contrary retain their warmth for a considerably longer time. 
 The results of some experiments by Liebenberg are shown in the following 
 table : — ■ 
 
 Loss of Heat by Soils 
 
 Nature of soil 
 
 Original temp. 
 
 After 4 hour 
 
 After 1 hour 
 
 After 2 hours 
 
 Coarse sand 
 
 41-25° C. 
 
 29-75° C. 
 
 24-25° C. 
 
 19-75° C. 
 
 Fine sand 
 
 41-75 
 
 28-25 
 
 23-25 
 
 18-75 
 
 Marls 
 
 40-00 
 
 27-50 
 
 23-00 
 
 18-50 
 
 Loams 
 
 40-00 
 
 27-00 
 
 22-00 
 
 18-00 
 
 Clay . . ■ . 
 
 89-50 
 
 26-00 
 
 21-50 
 
 18-00 
 
830 EYGIEXE 
 
 The following table by Schilbler shows the results of his observations on 
 
 the power possessed by various soils of retaining heat, a power dependent 
 
 partly on the physical properties and partly on the chemical composition of 
 
 the soil : — 
 
 Power of retaining Heat, 100 beiyig assumed as the Standard 
 
 Sand, with some limestone . . 100 
 
 Pure sand , 95'6 
 
 Light clay 76-9 
 
 Gypsum , . . . . . 72-2 
 
 Heavy clay ..... 71'1 
 
 Clayey earth C8'4 
 
 Pure clay 06*7 
 
 Fine chalk 61-8 
 
 Humus 49 
 
 Usually radiation takes place more rapidly than absorption, particularly 
 where herbage is abundant, so that soils cool more rapidly than they heat. 
 Jourdanet cites a remarkable instance of this which was noticed in some of 
 the marshes in Mexico, which cool so rapidly at night that the evolution of 
 malaria is prevented, the marsh consequently not being dangerous at night. 
 On one occasion when the air temperature at a height of sixteen feet from 
 the ground was 58° F., that of the marsh at the ground level was only 32° F. 
 The effect of herbage on both the radiating and absorbing power of the soil 
 is often very great, a difference of as much as 30° F. having been recorded in 
 a tropical climate between the temperature of a naked rock and an adjoining 
 one which was covered with grass. 
 
 The effect of soil temperature on disease was first described by Delbruck, 
 who called attention to its importance in connection with an epidemic of 
 cholera at Halle in 1867 which appeared to be associated with a maximum 
 soil temperature combined with a certain degree of soil moisture. It doubt- 
 less also influences the spread of malaria, while recently Ballard has demon- 
 strated its important relations with the occurrence of summer diarrhoea, 
 Pfeiffer, Kiichenmeister, Fleck, and Fodor have also investigated this subject. 
 
 Estimation of Soil Tempebatuke 
 
 The method by which their observations on the temperature of the 
 soil was carried out is thus described by Lewis and Cunningham. A 
 shallow shaft or well of sufficient capacity to allow of easy entrance was 
 sunk in the soil to a depth of slightly over six feet, and was lined with bricks 
 and mortar. An opening was left in the floor to allow of di'ainage of any sur- 
 face water which might obtain entrance, and two openings were left in the 
 brickwork of one side of the shaft at depths of three and six feet respectively 
 leading into wide tubes of perforated zinc, which penetrated the soil hori- 
 zontally from the outer surface of the brickwork and terminated in open 
 extremities in the earth. These tubes were of sufficient diameter to allow of 
 a narrow board, carrying the thermometers, being pushed into them. The- 
 thermometer board had a wooden plug and handle which fitted into the 
 mouth of the tube, whilst the opening in the brickwork was closed by an 
 accurately adjusted wooden cover, and further secured by being coated 
 externally with moist clay. 
 
 A thick wooden lid, covered with a layer of turf, closed the mouth of the 
 shaft, and the entrance of rain or access of sun to the cover was prevented 
 by a thatch roof about five feet from the ground. 
 
 Observations were made at the same hour every day, and the thermo- 
 meters immediately returned to their places in the perforated zinc tubes let 
 into the earth, care being taken, before returning them, to raise the temperature 
 of the minimum, and to depress that of the maximum instrument considerably 
 above and below the temperature of the soil. 
 
. THE INFLUENCE OF SOIL ON HEALTH 331 
 
 Fodor advises that the thermometers should be placed in a two-inch tin 
 tube, the interval between the thermometer and the casing being filled in 
 with fine sand. 
 
 DISEASES ATTRIBUTED TO CONDITIONS OP THE SOIL 
 
 The permeability of the soil, its composition and that of the ground air, 
 the amount of heat and moisture present, and the variations in level of the 
 subsoil water, have been found by numerous observers to bear important re- 
 lations to many of the diseases which afflict mankind, while the lower animals 
 are also, though perhaps in less degree, liable to suffer from like causes. 
 
 Coincident with the disappearance of oxygen from the ground atmosphere 
 an equivalent amount of carbon dioxide is produced, which when the pressure 
 of the air above ground is increased, or when the temperature is lowered, 
 penetrates the soil. This drives out before it the ground air, which may thus 
 enter the cellars and basements of houses, from which it will probably ascend, 
 through the influence of convection currents, to the upper stories. A similar 
 effect has been shown to occur in consequence of heavy rains, the water 
 filHng up the interstices of the soil near the surface, and so forcing down the 
 gases in the soil, which will then escape at places where the ground is dry, as 
 under buildings, this effect being the more likely to happen the greater the 
 porosity of the soil. 
 
 Many basement dwellings extend from three to ten feet below the surface 
 of the ground, and seeing that at a depth of thirteen feet (four metres) the 
 amount of oxygen present in the air entering them from below may be from 
 one-third to one-half of the normal percentage, the carbon dioxide is in- 
 creased inversely as the amount of oxygen present. Accordingly, it is evident 
 that the danger incurred by the inhabitants of such dwellings may be very 
 much the reverse of imaginary, particularly if the soil be much polluted with 
 organic matter. This will be the more rea.dily appreciated when we remember 
 that the soil, and so the ground air also, teems with micro-organisms of 
 various kinds, some of a pathogenic nature. These, when the soil is dry, 
 being carried in various directions by the currents of ground air, and finding 
 exit at the surface, may affect the atmosphere of the immediate or of con- 
 tiguous localities, or may be carried to considerable distances from the spot 
 where they originated. If, on the other hand, such diffusion is prevented by 
 the effects of the pressure or temperature of the air above, or by a blocking 
 of the upper layer of the soil by water, they will tend to be carried directly 
 into buildings along vdth the impure ground air. 
 
 In spring and early summer, however, the ground being cooler than the 
 air above, the ground air, being in consequence denser and heavier, is not so 
 easily displaced as at other seasons of the year. In autumn, on the contrary, 
 the ground air is displaced with greater ease, and so is more likely to be forced 
 out from the interstices of the soil into the atmosphere above. These facts 
 would afford an explanation of the comparatively slight prevalence, in spring 
 and early summer, and greater prevalence in autumn, of certain epidemic 
 infectious diseases which may be thought to depend on movements of the 
 ground air. Similar conditions may, perhaps, explain also the greater Likeli- 
 hood of infection at night, which is believed to occur in connection with such 
 diseases as malaria and yellow fever (Eohe). 
 
 The level of the ground water and the amount of moisture in the soil 
 above it, have been shown to have a considerable influence on the extent of the 
 putrefactive processes going on in the soil, and these in towns will influence- 
 
332 HYGIENE 
 
 the composition of air and drinldng water, and so directly or indirectly the 
 health of the population of the district. Thus dampness of the surface will 
 cause a cold soil and a misty air, and as a result, perhaps, encourage such 
 diseases as paroxysmal fevers, rheumatism, neuralgia, and various lung 
 affections. On the other hand, certain dry and apparently pure soils, which 
 would usually he considered healthy, are apt to cause malaria, the reason 
 for which is not very evident ; it may, however, be explicable *in the manner 
 already suggested, that the porosity of the soil allows the transference of 
 contaminated air from considerable distances. 
 
 In several of the diseases held to be related to telluric conditions, recent 
 researches have shown that definite micro-organisms are invariably found 
 in the blood or tissues of affected persons or animals, although the exact rdle 
 played by such microphytic forms in the causation of disease has not been 
 in most instances at all certainly determined. It is, therefore, highly desir- 
 able, not only that the life history of these bacteria should be studied in the 
 body of their host, but also that diligent search should be made for them 
 among the numerous micro-organisms which are always to be foimd in ordinary 
 surface soil, so that the relations of environment to their destruction or special 
 multiplication at any given time and place may be as nearly as possible 
 determined. Some observers have thought that under certain circumstances 
 bacteria ordinarily harmless may take on pathogenic properties, and although 
 the weight of evidence may be against this, it seems hardly possible, on any 
 other assumption, to explain the sudden appearance of a given disease in 
 absence of all apparent relation to pre-existing disease of like sort, or to ex- 
 plain the various types presented by one and the same disease in different 
 epidemics. As Buchanan says, 'Looking to the prodigious part that bacterial 
 life plays in the economy of nature, it is hardly too much to expect that 
 morbific bacteria may come hereafter to be known, not merely as producing 
 disease under certain conditions, but as having, under other conditions, many 
 other functions in that economy.' ' Whether, and if so where, and under 
 what conditions, the bacilli found in tubercle, for instance, exist elsewhere 
 in some harmless state, and by what change of conditions they can become 
 morbific, are problems of the highest importance.' We know that under 
 conditions of artificial cultivation, which have been carefully studied of late, it 
 is possible to so reduce the virulence of many pathogenic bacteria that ulti- 
 mately their injection into the living body is practically without appreciable 
 effect, and fails even in conferring immunity against the subsequent action 
 of more potent cultures ; is it then beyond the region of possibility that such 
 organisms under certain other conditions may once more regain their original 
 pathogenic properties after a temporary stage of suspended function, in a 
 reverse manner to that in which these properties were originally lost ; that 
 such changes should be capable of occurring in the interstices of the soil as 
 well as in the culture-tube of the bacteriologist ? 
 
 Investigations on these Hnes promise not only information as to the pro- 
 duction of disease, but knowledge also of methods of preventing disease, which 
 is the primary aim of sanitary science. Much has already been done, but 
 much still remains to be done before what we think we know can be con- 
 sidered to possess firm basis of fact. In the following pages are given the 
 results of research up to the present time on the relation to soil-conditions 
 of certain diseases ; but unfortunately the subject is still to a considerable 
 extent veiled in obscurity, so that, even as regards not a few diseases in which 
 such connection would appear most indisputable, we are as far as ever from 
 a knowledge of hoAV best to combat the malign influences that confront us. 
 
THE INFLUENCE OF SOIL ON HEALTH 333 
 
 Typhoid ok Enteeic Fever 
 
 Althougli until comparatively recent years thia disease was confounded 
 with typhus, we have evidence that it has asserted its presence in more or 
 less virulent forms for at least the last two hundred years, Baglivi and 
 Lancisi having described cases, apparently of this disease, which occurred at 
 Eome at the end of the seventeenth century, but which, however, they 
 believed to be a form of ague. It is also of interest that Dr. Norman Moore 
 has proved from the memoranda of Dr. Mayerne, physician to James I., that 
 the disease of which Henry, Prince of Wales, died in 1612 was enteric fever. 
 
 The chief credit, at any rate in this country, in demonstrating the differ- 
 ences between typhoid and typhus fevers is undoubtedly due to Dr. A. P. 
 Stewart, who, as the result of his observations, came to the conclusion that 
 the differences between the two diseases were ' so marked as to defy miscon- 
 ception, and to enable the observer to form with the utmost precision the 
 diagnosis of the nature of the disease and the lesions to be revealed by dis- 
 section ' (1840). Strother, however, in 1729, first gave a description of the 
 anatomical characters of the disease, which, he says, is a ' symptomatical 
 fever arising from an inflammation, or an ulcer, fixed on some of the 
 bowels.' The fact of this disease affecting specially the bowels obviously gives 
 special opportunity for fouling tbe earth, and so for the passing on of the 
 disease to other persons. 
 
 In certain placestyphoid appears to be endemic, but elsewhere its prevalence 
 has been proved for the most part to be largely due to the movements and inter- 
 course of human beings, numerous instances having been placed on record in 
 which outbreaks occurring in localities previously entirely free from the disease 
 have been traced to the arrival of a patient already suffering from enteric 
 fever, opportunity having been thus afforded for specific contamination of 
 the soil. Murchison and others have, indeed, affirmed the disease to be capable 
 of arising de novo when surrounding conditions were favourable thereto, sup- 
 porting their view with numbers of cases in which the most exhaustive inquiry 
 had failed to elicit any trace of a pre-existent human case. This theory, how- 
 ever, finds little acceptance at the present day, and later writers have attempted 
 to explain Murchison's cases on the supposition that the bacillus which is 
 believed to be the exciting cause of the disease is a vegetable parasite having 
 an existence independent of the human subject, capable of completing its life- 
 cycle, and of reproducing itself, if not in some other animal body, in the earth 
 or atmosphere. If this be so, one may thus account not only for those cases 
 occurring in this country which it has been impossible to trace to infection from 
 one person to another, but also for the fact that travellers have been stricken 
 down with this disease in tropical countries believed to be entirely uninhabited. 
 
 For the most part, however, typhoid undoubtedly spreads indirectly 
 through the stools from one or more specific cases of the disease, infecting 
 drains, sewers, cesspools, or the soil itself, by which means the drinking 
 water, air, or food become contaminated, and thus secure propagation of the 
 malady in various directions ; the water, of course, usually becoming infected 
 from having passed through already polluted earth. By the admixture of 
 such water with milk, or from dairy utensils having been washed out with it, 
 we have other means by which the disease may secure further victims. 
 
 For the system to be affected with typhoid, the essential cause of the 
 malady must doubtless gain access to the alimentary canal, a possible way 
 being that the dust of dried excreta may be carried in the air to the mouth, 
 and then swallowed with the sahva ; but the more frequent channel is 
 
334 HYGIENE 
 
 undoubtedly by the ingestion of di-iuk and food. So great a mass of evidence 
 has been collected on this point that the fact has well-nigh been lost sight 
 of that in many cases the diinking water, for instance, is only the vehicle, the 
 soil itself being the situation not only from which the poison is immediately 
 derived, but one in which it is capable of lying dormant for an indefinite 
 period. A case which illustrates this point is related by Von Giett. A man 
 who had acquired enteric fever elsewhere brought it to a village. His eva- 
 cuations were buried in a dung-heap. Some weeks later five persons engaged 
 in removing some of the dung were attacked by the disease ; their discharges 
 were sunk deep in the heap. At the end of nine months it was completely 
 cleared out by two workmen, one of whom fell ill of enteric fever and died. 
 
 Murchison also states that he has seen single cases of enteric fever 
 arising in the same house again and again at intervals of a year or longer. 
 In such a ease it is obviously unnecessary to suppose that on each occasion 
 the specific poison had been brought afresh to the place, itbemg much more 
 hkely that the germs of the disease had been present during the whole 
 period, and had from time to time been roused to increased activity by the 
 changing influence of their environment. Several instances also have been 
 recorded in which boys who had watched the clearing-out of the soil 
 around old and imperfect drains had shortly afterwards been smitten down 
 with the disease. 
 
 In many country villages typhoid has been known to break out every 
 autumn, although no sanitary defect could be discovered. In such cases it 
 is probable that a large area of the soil is polluted, and thus, particularly 
 where the water-supply is derived from surface-wells, it is impossible to 
 secure immunity from the disease unless an entirely different source of 
 water for drinking purposes be provided. 
 
 An instance of an outbreak of enteric fever, traced to the contammation 
 of milk with such a water-supply, is seen in Dr. Ballard's report of his inves- 
 tigations at Armley, near Leeds, in the summer of 1872. He found that aU 
 the early cases, with one exception, had been supplied with milk from the 
 same dairy, which had been mixed with water obtained from a pump on the 
 premises. He found, moreover, that about a month before the epidemic 
 appeared the dairyman had himself been ill with typhoid fever, and that his 
 excreta had been deposited in a privy, the drainage from which escaped into 
 the soil. From thence faecal matter had apparently been washed by heavy 
 rains occurring at the time, into the well from which the pump was fed ; 
 this supposition being borne out by the fact that at the bottom of the well a 
 layer of filthy mud was found from which bubbles of gas escaped when it 
 Avas disturbed, while from the sides of the well next the privy a similar black 
 material was found to be oozing. 
 
 The prevalence of typhoid fever is markedly affected by seasonal and cli- 
 matic influences, the greater number of cases in this country occurring in the 
 autumn, and being, in particular locaHties, especially large when the preceding 
 summer has been hot and dry, while, on the other hand, if the summer has 
 been damp and cold, the disease will not attain so high a point. The statistics 
 of the London Fever Hospital for the years 1848-1870 inclusive show that 
 the number of admissions was greatest each year from August to November, 
 while it w is least in April and May. Buchan and Mitchell, dealing with 
 enteric fever deaths, state that, taking the average of a large number of years, 
 the maximum point is reached in the last week in October, while the disease 
 does not fall below its average until the last week in February, attaining its 
 absolute minimum from the middle of May to the end of June. 
 
 Observations made on this subject in Berlin and Basle also show a 
 
THE INFLUENCE OF SOIL ON HEALTH 335 
 
 similar relation between intense summer heat and excessive prevalence of 
 typhoid, the maximum amount of fever in these places also occurring two or 
 three months later than the maximum temperature, while at Munich the re- 
 tardation is more marked, the greatest number of deaths occurring in 
 February. Fodor shows that at Buda-Pesth the number of deaths usually 
 rises in winter and spring, the severest epidemic that has visited that place — 
 that of 1864-65 — having reached its maximum in January, and from these 
 facts he argues that, since the typhoid curve shows no relation to those of 
 •either temperature or of CO2 production, the prevalence of the disease is not 
 dependent on putrefactive processes going on in the superficial layers of the 
 soil. These results are arrived at by comparing the death curve with the 
 condition of soil at the time of infection, or at a period of from four to five 
 weeks previous to the termination of the disease, thus allowing for (1) incu- 
 bation about two weeks, though it is often much shorter — Zehndes, for 
 instance, stating that in pregnancy it may only be from twenty-four to forty- 
 eight hours ; and for (2) period of illness preceding death, which Murchison 
 found, as an average of 112 cases, to be as nearly as possible 27| days. 
 
 Although no pronounced relation could be found between the death rate 
 and the temperature or putrefactive activity of the soil, Fodor has demon- 
 strated an apparent close connection between the typhoid curve and one 
 representing variations in the level of the Danube, both these curves, almost 
 without exception, rising and falling together. Thus at the begining of 1872, 
 both of these curves rose simultaneously, attained their acme in the middle of 
 the year, and then both fell off in a like manner. In this connection it must 
 be remembered that the level of the Danube exerts a very regular influence 
 ■on the ground-water level throughout the greater part of the town, and thus 
 it would appear that in Buda-Pesth typhoid is most commonly related to a 
 rising level of the water in the soil. In Munich, where Buhl applied the 
 observations of Pettenkofer on cholera to the incidence of typhoid, and in 
 Berlin, on the other hand, the reverse phenomenon has been recorded, the 
 disease in both places increasing as the ground water falls. This latter state 
 of things has been referred to a more active decomposition of organic material 
 in the more superficial and polluted layers of the soil, following on the abstrac- 
 tion of a certain amount of water from the earth, and possibly this explana- 
 tion may be correct as regards Berlin, where outbreaks most commonly occur 
 in autumn. In Buda-Pesth, however, as already stated, the disease is usually 
 more prevalent in winter and spring, and seeing that there is often so close 
 a connection of epidemic enteric fever with variations in level of the ground 
 water, we may perhaps infer that it is there influenced to a certain extent by 
 processes going on in the deeper layers of the soil, those layers indeed in 
 which the rise or fall of the ground water is felt. 
 
 Liebermeister and Buchanan, with considerable reason, have supposed 
 that soil-water observations simply illustrate the commimication of the disease 
 by means of drinking water ; the water of surface wells being generally more 
 impure when the level of the soil water is persistently low, when also there 
 will be more likelihood of noxious matter accumulating in the stagnant water 
 in the soil. 
 
 Eainfall, and the consequent wetting of the superficial layers of the soil, 
 has obviously no influence in regulating the spread of typhoid, since the 
 disease may prevail to an equal extent whether the surface of the earth is dry 
 or the reverse, and this even when the wettmg of the upper stratum is 
 markedly related to the amount of the rainfall. 
 
 Seeing, then, that at Buda-Pesth at any rate, and perhaps at Munich, there 
 is proof of a close relation between the extent to which typhoid prevails, and 
 
336 HYGIENE 
 
 the variations in level of the ground water, but to no other meteorological 
 state, it would be well to compare the conditions in Buda-Pesth with those 
 in other cities in which this subject has been investigated, the following 
 points being those which appear specially worthy of note : — 
 
 1. That the groimd water in that town hes for the most part near to the 
 surface, especially in those parts which have suli'ered most fi'om typhoid. 
 
 2. That the variations of level are very small, and that they are regulated 
 by the level of the Danube. 
 
 3. That the horizontal movement of the ground water is very slow ; and, 
 
 4. That, in consequence of this movement being particularly slow, the 
 water stagnates in the polluted soil in those parts of the town which suffer 
 most severely when the Danube rises. 
 
 At present, however, but little is certainly known as to the influence of 
 telluric conditions on the prevalence of this disease, and further research is 
 needed before any dogmatic statement can be made ; but notwithstanding 
 the obscurity which still hangs over this subject — an obscurity increased by 
 the fact that Buhl's law, or the converse proposition as enunciated by Fodor, 
 is, as it seems, applicable to certain places only, having no relevancy for 
 others — no one can deny the importance of the soil as the breeding place of 
 the typhoid poison. No doubt, as Hirsch says, tj'phoid may develop under 
 circumstances where any influence of the soil is not only highly improbable 
 but even excluded as an etiological factor altogether, as in epidemics in 
 rooms. But those cases are by no means in contradiction of the theory ; 
 they serve rather to corroborate it, inasmuch as the same conditions that 
 cause or assist the typhoid poison to ripen or acquire potency in the soil may 
 be met with also outside the soil. As Lindwurm very justly says, ' What 
 the soil is on a large scale, the same on a small scale are also the floors 
 of rooms, the walls of houses, the drains of privies and the like. Just as it 
 matures at some depth in the ground, so also may the typhoid germ obtain 
 the necessary conditions for its growth in a seam or cleft in the flooring of a 
 room, or in the loosened mortar and sand between stones and slabs.' 
 
 The Typhoid Bacillus 
 
 To Eberth, Gaffli-y, Klebs, and Koch we owe the discovery of a specific 
 microbe which is at the present time believed to be the essential cause of 
 typhoid fever. Prior to the publication of their researches, Eecklinghausen, 
 Klein, Browicz, Fischel, and other observers had described colonies of micro- 
 cocci which they had found in the mucous membrane of the intestine, in the 
 kidneys, the spleen, and even in the muscular tissue of the heart, but the 
 presence of these cocci was probably merely accidental and had no relation to 
 the occurrence of the disease. 
 
 There is great difficulty in obtaining the specific bacillus from typhoid 
 stools, because of the large number of other micro-organisms which are 
 present, and which in the course of their growth liquefy the gelatine. 
 Chantenesse and Widel, however, have shown that if trichloride of iodine 
 be added to the gelatine in which the cultivation is made, the growth of the 
 ordinary putrefactive organisms is aborted while the typhoid bacillus is un- 
 affected. A similar result may be obtained by keeping the growth at a 
 temperature of about 45° C, at which the typhoid bacillus alone is capable 
 of existing, or by adding to the culture medium a small quantity of carbolic 
 acid. 
 
 By adopting one or other of these methods, the presence of the typhoid 
 bacillus has been detected in water known to have caused an outbreak of 
 
THE INFLUENCE OF SOIL ON HEALTH 337 
 
 fever even when chemical analysis failed to indicate any serious organic 
 contamination. In an epidemic investigated by Bonner, he was unable to 
 find the bacillus in the water of a well supposed to have caused the outbreak, 
 but found it abundantly in the soil in the neighbourhood of the well. 
 
 Inoculation experiments with the bacillus on animals have not up to the 
 present met with much success. 
 
 ' The prophylactic measures against the spread of typhoid fever comprise 
 isolation of the sick, prompt disinfection and careful disposal of the dis- 
 charges, and cleanliness in the widest sense. The water and food supplies 
 must be carefully guarded against contamination with the poison, and all 
 decomposing animal matter and excreta must be removed from the immediate 
 vicinity of dwellings. The requisites for prevention may be summed up as 
 pure air, pure water, uncontaminated food, and a clean soil.' 
 
 DiPHTHEEIA 
 
 Although not long since mainly prevalent in rural districts, diphtheria 
 is a disease which of late years has unfortunately become exceedingly pre- 
 valent in towns as well, London now showing a greater rate of mortality 
 from this disease than any other district in England and Wales. It was not 
 until 1855 that it came at all prominently into notice, in which year, and 
 those immediately following, numerous outbreaks occurred in various parts of 
 England, since when, to quote Dr. Thorne Thome's words, it has been an 
 almost continuous and, generally speaking, an increasing cause of death 
 amongst us. This is strikingly shown by the fact that within the last twenty 
 years the total annual number of deaths from diphtheria in England and 
 Wales has more than doubled, while in London it has more than trebled in 
 the same length of time. It is of course possible, however, that the previous 
 excessive prevalence in rural districts may be only masked at the present 
 time by some cause common to large centres of population, such as personal 
 contagion. 
 
 In 1859 the Medical Department of the Privy Council undertook a some- 
 what extensive inquiry into the subject, as the result of which it appeared 
 that the disease prevailed for the most part, although not entirely, in damp 
 and marshy situations and on cold wet clay soils. Dr. Greenhow also reported 
 that associated with it he had found a marked prevalence of certain diseases 
 affecting the nasal and buccal mucous membranes of certain of the domestic 
 animals, such as cattle and horses, although he did not succeed in tracing 
 any definite connection between such affections and the disease in human 
 beings. In these observations he paved the way for the recent discoveries of 
 Eoux and Yersin, Klebs, Loffler, and Klein, by whom it has been determined 
 that there is an intimate relationship between human diphtheria and a some- 
 what similar disease affecting certain of the lower animals, particularly cats. 
 
 The possibility of such a mode of infection may perhaps account for the 
 fact that it has often appeared impossible to trace any cause to which an out- 
 break could be attributed. Dr. Airy, who in 1880 undertook an inquiry for 
 the Local Government Board, was particularly struck with this point, and 
 he, in this connection, recalls the opinion of Prof. Burdon Sanderson, who 
 in 1859 reported that * the circumstances were permanently such as to shut 
 out even the possibility of personal communication.' Dr. Airy further re- 
 ported that the disease was more prevalent on clayey than on sandy soils, 
 that its incidence was greatest on persons liable to throat affections, and 
 further that the only view which appeared consonant with all the facts 
 which he had gathered together, was that which attributed the affection to 
 VOL. I. z 
 
338 HYGIENE 
 
 a living organism capable of infecting milk and air and of being transmitted 
 by wind currents. 
 
 This view of the carriage of diphtheria infection by milk has received 
 support from several investigations on the subject, notably in one conducted 
 by Mr. Power during an epidemic of diphtheria in North London in 1878, 
 in which it appeared probable that the cow herself might have been con- 
 cerned in the infection of the milk. A like difficulty in referring the outbreak 
 to a human source is seen in a report by the same gentleman concerning 
 an outbreak about ten years later at York Town and Camberley, although 
 its relation to disease of the cows belonging to the dairy farm from which the 
 milk was obtained seemed almost as indefinite. A similar possible source 
 of infection is suggested in reference to an outbreak investigated by Mr. 
 Power at Hendon in 1883, Dr. Buchanan saying in his report for that year 
 that ' at Hendon it was difficult to refuse this explanation of the facts, 
 since the milk at the very time it was operative for harm . . . exhibited a 
 peculiar ropiness and unpleasant taste which caused some of its habitual 
 consumers to return it to the dairy ; and for these phenomena, no condition 
 about the dairy or its utensils could be regarded as responsible.' 
 
 Prior to this, however, Dr. Thursfield, in a series of papers contributed to 
 the Lancet in 1878, had expressed his opinion that diphtheria, essentially a 
 disease of rural districts, otherwise the most healthy as indicated by the 
 fever death-rate, was intimately connected as regards local conditions with 
 structural dampness of habitation. This statement, at the time, being con- 
 trary to accepted ideas, was severely challenged by those who maintained that 
 typhoid fever and diphtheria alike were the result of exposure to filth 
 accumulation, and that the explanation of the special incidence of diphtheria 
 upon rural districts, which was at that time apparent, was due to the fact that 
 the towns had relatively made more sanitary progress than the country dis- 
 tricts. Dr. Simpson, in reporting on an epidemic at Shaftesbury in 1885, 
 refers especially to an outbreak in three successive Novembers in an old 
 dilapidated house standing on a water-logged soil, where the walls of the 
 ground and upper floors were found to be wet and covered with moulds, and 
 the woodwork rotten. 
 
 That structural dampness of dwellings is a most important factor in the 
 development of diphtheria is now generally admitted, such a condition being 
 most favourable for the incidence and severity of the affection and the per- 
 sistent vitality of the germ of the disease. As Dr. Thursfield has pointed out, 
 this dampness of houses may depend on the subsoil water being so close to the 
 surface that the cellar always contains more or less water, or upon the house 
 being built upon a retentive clay without the precaution having been taken of 
 providing a damp-proof substratum, but even more frequently, upon the house 
 being deeply embedded at the back or slightly all around. The material of 
 which a house is built may also be conducive to a similar result, a porous 
 absorbent stone retentive of moisture being very favourable to the incidence 
 of the disease. Trees surrounding and shutting in the house will naturally 
 Aggravate the liability to the deposition and retention of moisture, provided 
 that the materials of which it is built are of a nature favourable to such 
 conditions. 
 
 Although dampness of site is undoubtedly a factor in the production of 
 outbreaks of diphtheria, particularly if such dampness be due to persistent 
 leakage from imperfect sewers or cesspools, it does not appear that there is 
 any direct relation between the occurrence of an epidemic and a rise or fall 
 of subsoil water, provided that the structure and atmosphere of the houses 
 are not affected. Many districts, which although usually dry are liable to 
 
THE INFLUENCE OF SOIL ON IlEALTU 339 
 
 •occasional floods, are remarkably free from the disease, so that it appears that 
 a persistent impregnation of the soil witli moisture is of more importance 
 than fluctuations in the height of the grou.nd water, particularly if these have 
 any considerable range. 
 
 It should be stated that Bruhl and Johr claim to have proved that an 
 increase of mortality from this disease is closely connected with prevalent 
 atmospheric conditions, the maximum mortality being in those places where 
 there is throughout the year less equability of temperature and humidity of 
 'the air. Where these conditions are more equable, or where the air is warm 
 and dry, the mortality is lowest. These statements are perhaps not so much 
 ,at variance with the view already advocated as might appear at first sight, since 
 the less or greater humidity of the lower strata of the atmosphere depends in 
 great measure on the dryness or the reverse of the upper layers of the soil. 
 
 That the specific poison of diphtheria consists of a living organism is now 
 pretty generally recognised, although there is some doubt as to its identity. 
 Klebs first pointed out that there is uniformly present in diphtheritic mem- 
 branes a bacillus possessing definite morphological characters which he be- 
 lieved to be peculiar to this disease. In addition, there are always present a 
 great variety of micro-organisms, chiefly micrococci, which have no particular 
 significance. Loffler confirmed the frequent presence in diphtheria of this 
 bacillus, and succeeded in isolating and growing it in suitable media, parti- 
 cularly on serum or in agar beef broth. He stated, however, that it was not 
 possible to find it in a number of cases that he examined, but Klein has uni- 
 formly found it in all recent cases examined by him ; moreover, Klein has 
 isolated the bacillus in cultures and produced therewith diphtheritic disease 
 in lower animals. 
 
 Eoux and Yersin, recently working at the Pasteur Institute, adopt the 
 Klebs-Loftier bacillus as the essential cause of diphtheria, stating not only 
 that they have been able to transmit the disease to pigeons and rabbits by 
 inoculations of this baciUus, but that the nutrient fluid in which it had been 
 grown, after being passed through a filter of unglazed porcelain, when injected 
 into the subcutaneous tissues of various animals (the required quantity de- 
 pending on the age of the culture), produced either a rapidly fatal result or 
 a less acute illness with subsequent paralytic symptoms. These investigators 
 found, moreover, that a growth of the baciUus may, if protected from air and 
 light, be kept for an almost indefinite time and still produce characteristic 
 symptoms in animals inoculated with it, but that, exposed to air and light, 
 it speedily loses its virulence. These facts would appear to warrant the sup- 
 position that the bacilli may exist, for an indefinite period, dormant in soil, 
 particularly that beneath dwelling-houses, where, protected from light and 
 excess of oxygen, and supplied with a necessary amount of heat, they would 
 regain their full energy as soon as their environment became more favom'able. 
 If the pathogenic nature of the Klebs-Loflier bacillus be admitted, it will be 
 obvious that such a state of affairs may have an important bearing in connec- 
 tion with outbreaks of diphtheria where there has been no evidence of im- 
 portation of the disease from without, but where there is a history of a previous 
 outbreak in the same house, perhaps after a long interval of years. 
 
 Cholera 
 The first and most obvious characteristic of this disease is its preference 
 for particular localities ; the conditions which determine its local settlement 
 being, as was shown by Sir John Simon in his Fifth Annual Report (1853), 
 certain demonstrable physical peculiarities which consist in the conjunction 
 of dampness with organic decomposition. 
 
 z2 
 
340 
 
 HYGIENE 
 
 Thus cholera is known to attack with the greatest virulence places of low 
 elevation, especially those which are thickly populated, and which have to 
 contend not only with their local impurity, but also "with impurities carried 
 into them by the drainage of ground water from places situated at a higher 
 level. A low level in itself, however, is not sufficient, unless it be combined 
 with a certain density of population, and it would appear that a comparatively 
 high temperature, both of air and soil, is a necessary factor for the epidemic 
 extension of the disease. Dr. Macnamara states that cholera is more rife in 
 low' alluvial soils, and that it advances from east to west, or exactly in the 
 direction fi'om the least to the greater recorded falls of rain, and, as a conse- 
 quence, just in time-relation wath the lowness of the ground water, which 
 will be first loAvest in eastern districts and last lowest in western districts. 
 
 Cholera, which has been kno"s^ai to be endemic in certain parts of India 
 since 1817, first appeared in England in 1831-32. A second great visitation 
 occurred in 1848-49, when the number of fatal attacks amounted to 53,293, in 
 addition to a great increase in the death-rate from diarrhoea. Even at this 
 time the fact became fully recognised that the spread of the epidemic was largely 
 influenced by filth-conditions afl'ecting air, soil, and water. In 1853 and 
 1854 the disease again appeared in London, the greatest number of deaths m 
 both years being recorded in the summer and autumn months. In these 
 epidemics the water-supply appeared to be the main factor in the propagation 
 of the disease, a point which will be found fully treated of in another section ; 
 but, as Dr. Greenhow pointed out in reporting to the General Board of 
 Health, polluted water was by no means the only cause of cholera spread, 
 the mortality having also ' generally borne a direct ratio to the amount of 
 atmospheric contamination ; ' soil conditions also playing an important part. 
 
 In 1865, an outbreak involving some sixty persons occurred in Southamp- 
 ton, whither the disease appeared to have been brought by steam vessels 
 from the East, where the Mecca pilgrims had been decimated by the disease 
 in the previous year. Again the epidemic first definitely appeared here in the 
 months of September and November, although isolated cases had been re- 
 corded as early as the middle of July. Other seaports w^ere aflected almost 
 simultaneously, and the disease gradually spread, causing eventually the 
 death of 14,378 individuals in England as a whole, of which London 
 accounted for nearly one-third. 
 
 In each of these epidemics the number of deaths had gradually decreased,, 
 although the total population had largely increased, and since 1866 cholera 
 has never succeeded in obtaining a firm footing in this country ; ' a result 
 which is no doubt due to the steady removal from amongst the people of 
 those insanitary conditions which are essential to its epidemic spread, and 
 to the increasing security afibrded by those measures of imperial and local 
 sanitary administration, by which it is sought to diminish sickness and 
 mortality from all preventable diseases ' (Thorne Thorne). 
 
 The incidence of cholera mortality in England during the epidemics of 
 1849, 1854, and 1866 is shown in the following table : — 
 
 Clwlera Mortality 
 
 Date 
 
 i 
 
 England and Wales 
 
 Louduu 
 
 Total deaths 
 
 Deaths per 10,000 
 living 
 
 Total deaths 
 
 Deaths per 10,000 
 living 
 
 1849 
 1854 
 1866 
 
 53,293 
 20,097 
 14,378 
 
 30 
 11 
 
 7 
 
 13,565 
 
 10,684 
 
 5,548 
 
 51 
 43 
 
 18 
 
THE INFLUENCE OF SOIL ON HEALTH 341 
 
 In this country the theory that cholera is mainly spread by means of the 
 'drinking-water has received much support, many instances in which this 
 had undoubtedly taken place having been recorded by Dr. Snow and other 
 observers ; but it must be remembered that dissemination may come about 
 in other ways : ' excrement-sodden earth, excrement-reeking air, excrement- 
 'tainted water ; these are for us the causes of cholera.' 
 
 In Germany, however, Pettenkofer and other observers have maintained 
 that the diffusion of cholera is mainly due to movements of the soil water, 
 the fundamental proposition being that cholera never prevails epidemically 
 where the soil is impermeable to water, or where the level of the ground 
 water is not liable to fluctuations. According to Pettenkofer the condition 
 of soil with which cholera is most apt to prevail is that which occurs when 
 the ground water, after having attained a higher level than usual, com- 
 mences again to fall. It is conceivable that an outbreak might be caused in 
 this way by noxious organic material being washed into wells to which it 
 •could not ordinarily gain access ; or again, it might be due to micro- 
 organisms present in the upper layers of the soil, which had been awakened 
 into activity by the combined influence of heat and moisture, becoming 
 diffused into the atmosphere when the superficial stratum of the earth again 
 became comparatively dry. 
 
 As these views have apparently met with but little acceptance in Eng- 
 land, it may be worth while to mention a curious fact quoted by Fagge in 
 connection with the East London epidemic of 1866, which appears to be 
 ■strongly in favour of Pettenkofer 's theory. In a school at Limehouse were 
 four hundred pauper children, not one of whom was attacked with cholera 
 •or with diarrhoea. Now, the house had its sole water-supply from the Old 
 Ford reservoirs, by which it had been thought the disease was spread, and 
 the children at all times made free use of the water. A special investigation 
 of the soil beneath this school brought to light the fact that it stood upon a 
 thick layer of fine brick-earth, and not of gravel, as appeared to be the case 
 with the streets immediately adjacent. 
 
 It should, of course, be remembered that Pettenkofer admits the neces- 
 sity for the presence of a specific germ, which, however, is only able to 
 assert itself in a virulent manner when its environment is suitable, so that 
 the state of the soil is really a predisposing cause. Nageli, a supporter of 
 Pettenkofer, further suggests that the soil gives off certain microzymes 
 which must be present in the body of everyone who is to afford favourable 
 conditions for the development of another set of microzymes derived from a 
 pre-existing case of cholera, which would, however, probably be too few to be 
 able to overcome the resistance of the living tissues, unless these latter had 
 £rst been weakened by the previous invasion of organisms peculiar to the soil. 
 
 The researches of Lewis and Cunningham at Calcutta seem to prove that 
 in that place the ground-water level, and, in a less marked degree, the rain- 
 fall, bear an inverse relation to the prevalence of the disease. When the 
 latter is at a maximum the water level is at a minimum, and when the 
 water level is at a maximum the prevalence of cholera is at a minimum. 
 There is, however, no correspondence as between one year and another or 
 •one month and another ; or, in other words, the absolute height of the sub- 
 soil water is hy itself of no significance for the amount of sickness. Still, 
 they call attention to the fact that the two years— 1871 and 1872— in their 
 eight years' period, which had the minimum number of cholera cases, were 
 •distinguished by the remarkably high level of the subsoil water. 
 
 Hirsch makes a great point of the statement that it is always an essential 
 circumstance that the soil be saturated with moisture, but only to that degree 
 
342 HYGIENE 
 
 at which it is still pervious to air, and that the organic matters accumulateJ 
 in it should undergo decomposition; under the influence of somewhat high 
 temperatures. Consequently the question is not as to the extent of the stra- 
 tum of soil saturated with moisture and permeable to air, or, in other words, 
 a question of the higher or lower level of the subsoil water, but it is a ques- 
 tion whether such a stratum exists at all, and that is, in his opinion, the gist 
 of the much quoted and much misunderstood doctrine of Pettenkofer as 
 to the significance of the height and fluctuations of the subsoil water in the 
 production and diffusion of cholera. 
 
 This conception of the part played by variations in the amount of water 
 m the soil is indeed upheld by Pettenkofer himself, who, writing in 1B70, 
 says : ' In my view, the level of the subsoil water reveals nothing more than 
 this, viz., the limits of a certain degree of humidity in a porous stratum of 
 soil, or the limits within which the pores are kept constantly full of water 
 and all the air driven out of them. Between that degree of humidity and 
 absolute dryness of the porous stratum, there are all those gradations when 
 the pores are filled in part with air and in part with water in varying propor- 
 tions, which we include altogether under the terms " moist " or " wet." The 
 point at which the pores are completely closed by water, is one that may be 
 observed with ease and certainty, and I have therefore chosen the level of 
 the subsoil water merely as an easily seen gauge and index of certain states^ 
 of humidity in the stratum of porous and permeable soil which overlies the 
 subsoil water, an index, viz., of the fluctuations in the state of humidity 
 ^^ithin a given period, and of the time that any one degree has lasted. 
 Whether that index is a few feet nearer to or farther from the surface does 
 not affect the value of its revelations. For the importance of the index lies 
 in this : that it declares the changes in the humidity of the overlying strata, 
 by means of the natural effects of those changes. The fluctuations in the 
 level of the subsoil water have a meaning for aetiology only because they 
 are traced back to those primary influences by which air and water are made 
 to share in varying proportion the possession of the pores of an impregnated 
 soil. Beyond that, they have no significance ; . . . looked at by itself and 
 for its own sake, the condition of the subsoil water has as little significance 
 as the hands and dial of a watch dissociated in thought from the works to 
 which they belong.' 
 
 Lewis and Cmmingham found no such close relation as that between 
 the cholera-curve and the curve of the subsoil water level, in connec- 
 tion with either conditions of soil temperature or amomit of carbonic acid, 
 although, in so far as soil moisture appears to determine the amount of car- 
 bonic acid in the soil, there was a general coincidence in regard to the latter 
 also. The relations between rainfall and prevalence of cholera, were not so 
 strongly marked as those between the latter and the water level ; and it even 
 appeared as though the inverse relation between conditions of water level 
 and prevalence of cholera were in some degree more distinct than the direct 
 one between the water level and the rainfall. 
 
 In another place Dr. Cunningham further says : ' One point seems 
 worthy of remark, and that is, that there is no evidence of the existence of 
 any common condition affecting local sources of water supply, and simul- 
 taneously affecting the prevalence of cholera and bowel complaints.' And 
 again : ' If the concurrence of a low water level and high prevalence of cholera 
 in Calcutta be more than a mere coincidence — if any causal relation exist 
 between the two phenomena — it cannot be a direct simple one depending on 
 the mere mass of water in the soil,' which, however, bears out Pettenkofer's. 
 contention. 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 343 
 
 Dr. Macnamara and others have asserted that not only is rain connected 
 with the development and dissemination of cholera poison, but that in India 
 no widespread epidemic can occur unless during or after rain. On the 
 other hand, there can be no doubt that the opposite effect is not infrequent, 
 particularly if the rainfall be excessive, prevalence of the disease being pre- 
 vented by destruction of the micro-organisms, partly as the direct result of 
 the amount of water in the soil, and partly from their being carried further 
 from the surface where they are no longer among surroundings favourable 
 to their continued existence. This fact is well shown in the following table 
 compiled by Dr. Macpherson : — 
 
 Table showing Deaths from Cliolera in Calcutta for Twenty -six Years 
 
 Month 
 
 Cholera. Total 
 
 Eainfall 
 
 Average 
 
 Range of 
 
 
 number of deaths 
 
 temperature 
 
 temperature 
 
 
 
 Inches 
 
 Fahr. 
 
 Fahr. 
 
 January . 
 
 7,150 
 
 0-21 
 
 63-4° 
 
 17-9° 
 
 February . 
 
 
 9,346 
 
 0-42 
 
 74-2 
 
 17-3 
 
 March 
 
 
 14,710 
 
 1-13 
 
 82-9 
 
 16-3 
 
 April 
 
 
 19,382 
 
 2-40 
 
 86-6 
 
 14-7 
 
 May 
 
 
 13,335 
 
 4-29 
 
 89-0 
 
 13-3 
 
 June 
 
 
 6,325 
 
 10-10 
 
 86-2 
 
 9-0 
 
 July 
 
 
 3,979 
 
 13-90 
 
 84-0 
 
 6-4 
 
 August , 
 
 
 3,440 
 
 14-40 
 
 82-6 
 
 5-2 
 
 September 
 
 
 3,985 
 
 10-40 
 
 83-8 
 
 6-6 
 
 October . 
 
 
 6,211 
 
 4-72 
 
 81-1 
 
 8-8 
 
 November 
 
 
 8,323 
 
 0-90 
 
 75-4 
 
 14-2 
 
 December 
 
 
 8,159 
 
 0-13 
 
 66-9 
 
 16-4 
 
 Similarly Fodor has shown at Buda-Pesth that, although a certain amount 
 of moisture of the soil is necessary for the appearance of an epidemic of cholera, 
 yet its spread is immediately checked if there be a considerable fall of rain. 
 Thus, in 1866, not only was the rainfall above the average, but the level of 
 the Danube rose unusually high, and, as a consequence, cholera, which had 
 been prevalent, fell off, notwithstanding that the atmospheric temperature 
 was high. Later on the rainfall diminished, the Danube fell rapidly, and 
 cholera once more asserted itself. In 1878 also, the disease increased in 
 July coincidently with a slight rainfall, reaching its highest point for the 
 year in the following month. In the previous year cholera had not been 
 present, due apparently to the fact that there had been an exceptionally 
 heavy rainfall during the summer and autumn. 
 
 At Buda-Pesth the epidemic zone, as it is termed by Fodor, coincides with 
 those parts of the town which lie lowest, there being, according to this ob- 
 server, an unmistakable connection between the height of the ground level 
 and cholera prevalence. He shows, however, that there are certain streets 
 which have been severely visited at various times, although situated in the 
 higher parts of the town ; but the anomaly is apparently due to their being 
 on the border of high ground, below which the surface sinks down suddenly. 
 Pettenkofer observed the same fact in the cholera epidemic of 1854 ; houses 
 similarly situated suffering as severely as those on a much lower level. Cordes 
 also states that in each of the eleven cholera epidemics which occurred at 
 Quebec between the years 1832 and 1866, the disease was especially prevalent 
 in the same parts of the town, viz. — four different areas which were sunk 
 below the general level ; and also that when the disease was introduced into 
 the higher parts of the town it did not spread. 
 
 A similar observation is recorded by Gilnther with regard to an epidemic 
 of cholera which occurred at Dresden in 1873, when a single street was 
 
344 HYGIENE 
 
 particularly affected, more tlian half of the inhabitants of twenty-two houses 
 invaded within a short time of one another having died. In this instance 
 the soil was found to be very polluted at the time of the epidemic, and the 
 drain connected with these houses had apparently been blocked for a con- 
 siderable time. 
 
 With regard further to the vexed question as to whether cholera is most 
 predisposed to by certain conditions of water or soil, although it can be 
 readily vmderstcol that the disease may result from the ingestion of water 
 containing the evacuations of cholera patients, it may also be supposed that 
 the use of impure water of any kind may aid the production of the disease, 
 although it cannot absolutely produce it. In this way we may, perhaps, 
 reconcile the conflicting theories, since, as has been showai previously, when 
 the ground water commences to fall after an unusually high rise, it would 
 naturally be preceded by a fall in the wells and other sources of drinking 
 water, and thus the drainage of the upper foul layers of the soil would be 
 carried by the ebbing tide of ground water into such outlets ; and so the 
 water supplied to a neighbouring population would become dangerously con- 
 taminated, and the more so the fouler the surface layers of the soil. The 
 facts which will be found quoted in another section on the influence of the 
 Lambeth water during the epidemic of 1854 seem to support this view, and 
 we have further evidence in favour of it derived from the investigation of 
 later outbreaks in Germany. The water may act in this way : either by caus- 
 ing a constant tendency to diarrhoea, a disease wiiich is for the most part 
 exceedingly prevalent, both antecedent to, and concomitantly with, cholera 
 epidemics, or by carrying into the alimentary canal organic matter of an 
 injurious nature. This either affords a fitting pabulum for the materies morbi 
 of cholera when brought into contact with it, or else may undergo special 
 chemical changes under the influence of small doses of the cholera microbe 
 as may convert it into a still more virulent poison ; or, again, by lowering 
 the normal powers of resistance of the body, may render it an easier prey, 
 not only to cholera, but to disease in many other forms as well. 
 
 Tlic ' Comma ' Bacillus 
 
 The researches of Koch, when working on the German Cholera Commis- 
 sion, have rendered it highly probable that a particular micro-organism, termed 
 the ' comma bacillus,' is always associated with Asiatic cholera. He has 
 found it not only in the alvine discharges of patients sufi'ering from the 
 disease, but also in the soil and in the water-tanks of infected districts. 
 Nearly fifty years previously Pacini had described ' vibrios ' as being present 
 in the intestinal discharges of cholera patients, but whether these bodies were 
 identical with Koch's bacillus is uncertain. 
 
 The specific micro-organisms called ' comma bacilli,' on account of their 
 shape, are to be found during the acute stage of cholera in the rice-water 
 discharge from the intestines, and consist of little curved rods of about the 
 thickness of a tubercle bacillus, but only half its length. They are actively 
 motile, and multiply by fission, often producing during the process S-shaped 
 or spiral forms from the progeny of an individual bacillus remaining m 
 contact with one another. 
 
 As to this bacillus, Macleod and Milles describe the following charac- 
 teristic points : ' It grows in and liquefies slightly alkaline gelatine ; more 
 slowly in neutral, scarcely at all in slightly, and not at all in markedly acid 
 gelatine. On a gelatine plate cultivation the individual colonies are round, 
 and lie in a funnel-shaped cavity ; when viewed with transmitted hght and 
 magnified, they look like ground glass, and the edge of the colony is finely 
 
THE INFLUENCE OF SOIL ON HEALTH 345 
 
 notclied. In a gelatine tube a funnel-shaped cavity forms at the top of the 
 puncture made by the inoculating wire, and lying in this cavity there is what 
 looks like an inverted air-bubble with its top on a level with tlie surface of 
 the jelly and open to the air ; along the puncture the gelatine lif^uefies, and 
 in this may be seen with the naked eye the whitish mass of colonies, par- 
 ticularly at the lowest part ; in from three to four weeks liquefaction spreads 
 to the whole mass, the bacilli falling to the bottom as a greyish-white sediment, 
 having a faint orange tint in certain lights, and if undisturbed a perfectly trans- 
 parent liquid separates a whitish scum on the top from the sediment below.' 
 Like most other pathogenic organisms, it grows best at about the body tem- 
 perature, any considerable range below or above this inhibiting the growth, 
 although the bacillus is not destroyed if the temperature be reduced to the 
 freezing point. It is aerobic, as if air be excluded growth ceases ; while it is 
 killed altogether by drying, as apparently spore formation does not take place. 
 
 Klein, however, on repeating Koch's experiments, has been unable to 
 confirm them, and consequently denies the pathogenic importance of the 
 comma bacillus. It has been shown that a similar organism is to be found 
 under normal circumstances in the mouth, and Klein believes its presence 
 dn the intestine to be merely accidental, the large numbers which he allows 
 are always to be found in cholera dejecta being due, in his opinion, to the 
 state of the alimentary canal being favourable to their multiplication. 
 
 Great stress has also been laid on the ease with which the vitality of the 
 comma bacillus is destroyed, as affording an argument against the likelihood 
 of its being the medium of infection. Not only are they killed by drying, 
 but also by the addition of small quantities of acid, so that they may be given 
 hy the mouth in the case of the guinea-pig without the animal being affected, 
 as the acidity of its gastric juice is sufficient to destroy them. In order to 
 obviate such an event when experimenting on the possibility of producing 
 the disease in the guinea-pig, Koch injected soda solution into the stomach, 
 and thus in some instances enabled the bacilli to reach the duodenum unin- 
 jured by the secretion of the stomach. Weak disinfectants and the presence 
 of putrefactive organisms are also inimical to the comma bacillus, Cun- 
 ningham having shown, for instance, that if a portion of a cultivation of 
 commas was inoculated into water or soil, the length of time during which 
 they could still be recognised in the living state depended directly on the 
 amount of pollution of the medium into which they were sown. Thus in 
 one series of experiments, when water polluted witli excreta was used, it 
 was found that all the bacilli had disappeared in a period varying from four 
 to nine days, while if the water had previously been sterilised by boiling, they 
 were found as late as the twenty-fifth day. Kitasato has apparently estab- 
 lished the same fact with regard to the action on the bacilli of the micro- 
 organisms present in f^ces. 
 
 From these experiments it would appear that cholera dejecta, when buried 
 in the soil or thrown into water, would be Hkely to be rendered innocuous 
 "within a comparatively short time, but in this connection an instance of in- 
 fection by water described by Macnamara is worthy of attention. He states 
 that ' a small quantity of the dejecta of a cholera patient was known to have 
 been washed into a vessel containing water ; the mixture, after being exposed 
 to the heat of the sun for one day, was swallowed by nineteen men on the 
 following morning ; within three days five of these were affected with cholera.' 
 
 Nicati and Eietsch have also shown that cholera bacilli are capable of 
 existing for as long as eighty-one days in the water at the port of Marseilles, 
 so that it is possible there may have been some source of fallacy in Cunning- 
 ham's experiments. 
 
346 HYGIENE 
 
 Moreover, tlicse observers found that a disease very similar to, if not 
 identical with cholera, could be induced in guinea-pigs by the injection of 
 comma bacilli into the small intestine. Koch, as has been said, improved on 
 these experiments by giving the culture by the mouth, mixed in sufficient of 
 an alkaline solution to prevent the destructive action of the gastric juice, and 
 at the same time inhibiting peristalsis by the use of tincture of opium. * Ex- 
 periments were made on thirty-five guinea-pigs ; of these, thirty died of cholera. 
 The symptoms during life and the appearances after death were identical 
 ■with those found in guinea-pigs which had received duodenal injections.' 
 
 The results thus obtained by Koch have been fully confirmed by MacleocE 
 and Milles, who come to the conclusions that the comma bacillus is invariably 
 present in cases of Asiatic cholera, although there is no evidence to show 
 that it is a normal inhabitant of the human alimentary canal ; that when 
 introduced into the small intestine of the guinea-pig in the manner and with 
 the precautions already mentioned, the organism multiplies in the alimentary 
 canal, and that associated with such growth changes are found similar 
 to those which are known to occur in Asiatic cholera when the human being 
 is attacked. 
 
 From a review of all the evidence brought forward by the supporters and 
 antagonists of Koch's views respectively, it may fairly be stated that the- 
 balance of scientific opinion is distinctly in favour of the pathogenic nature 
 of the comma bacillus. Finkler and Prior, indeed, have described another 
 bacillus found by them in cases of cholera nostras, which, however, is not 
 only readily distinguished from Koch's bacillus by the manner of its growth 
 in various nutrient media, but which is probably never present in cases of 
 true cholera. 
 
 In the light of what has been stated with regard to the aetiology of the 
 disease, the prophylactic measures to be taken against the invasion of cholera 
 obviously comprise such as will prevent its admission into a community, or 
 hinder its spread if it be introduced from without ; it being also of great 
 importance to reduce if possible the individual susceptibility to attack. 
 
 In this country confidence is no longer placed in a system of quaran- 
 tine for the prevention of cholera, scientists being now for the most part of 
 opinion that it is not only easier, but far more effective, to provide against the 
 development of cholera by such improvements in general sanitation as will 
 render it difficult for the disease to obtain a footing. Pettenkofer has well 
 expressed the contrast between the efficiency of quarantine and local sanita- 
 tion as safeguards against cholera in comparing an epidemic to the explosion 
 of a powder magazine. The powder represents the local conditions pre- 
 disposing to an outbreak, while the virus of cholera is the spark which can 
 evade the strictest quarantine. * It is vdser, therefore, to seek out and 
 remove the powder than to run after and try to extinguish each individual 
 spark before it drops upon a mass of powder, and, igniting it, causes an 
 explosion which blows us into the air with our extinguishers in our hands,' 
 
 It is specially necessary to guard against pollution of the soil, since such 
 a state of things means in all probability contamination also of water and of 
 air, all of which conditions will certainly encourage the incursions of the dis- 
 ease. Moreover, since it has been definitely proved that the discharges from 
 the stomach and intestines contain the active agents for propagation of the 
 disease, and that at the same time the bacilli are more easily destroyed when 
 first carried out of the body, the immediate disinfection of all such discharges 
 must be carried out by some efficient substance, such as corrosive sublimate 
 or carbolic acid, which Koch has shown is capable of killing the comma 
 bacilli when diluted to the extent of one part in fifty with water. 
 
THE INFLUENCE OF SOIL ON HEALTH 847 
 
 MALAIilA 
 
 In spite of the wide distribution of malarial fevers, of their disastj'ous 
 effects upon the population of countries in which they prevail, and of the 
 vast extent of the literature of the subject, we are unfortunately almost as far 
 as ever from an exact understanding of the precise conditions necessary for 
 their existence or production. There is, however, a general consensus of 
 opinion that malaria most abounds in jungle, swamps, and virgin forests, 
 the disease showing an evident relation to low land, abundant water, and 
 hot moist climates, and North has called attention to the fact that if a 
 physical map of Italy be compared with the map of Signor Torelli showing 
 the local distribution of malaria, such relation of the disease to water 
 temperature and altitude of the land becomes well-nigh a certainty. In 
 the province of Eome the disease is found to be generally most severe on 
 low-lying ground in valleys and in marshy districts ; there, curiously enougli, 
 the distribution of the population is the reverse of that which usually obtains, 
 for whereas in most civilised countries the population is densest m the plains 
 and much more sparse on the mountains, in the province of Eome exactly 
 the opposite state of things holds good, the mountain population being nearly 
 2| times as numerous per square kilometre as the dwellers in the plains. 
 It was this curious reversal of the general rule that caused North to carefully 
 investigate the matter with the object of determining, if possible, whether 
 it was malaria which in the first instance compelled the inhabitants of 
 the plains to take refuge on the hills, or, on the other hand, whether having 
 been driven thither from political causes, malaria had stepped in subsequent 
 to the abandonment of the plains, and in either case where and when such 
 causes first came into operation. He comes to the conclusion that the 
 Campagna was abandoned from causes purely political, Nature being then 
 allowed her own way in a country where the unceasing toil of man is required 
 to keep her under control. In even the later days of the Roman Empire, 
 places now absolutely uninhabitable were not only inhabited, but held in 
 high esteem by the Romans as health resorts, so much so that the whole 
 coast-line of the province was covered with their villas and country houses, 
 of which the ruins still exist, and which Pliny states to have been maintained 
 in a state of magnificence incompatible with the presence of such an enemy 
 to health as malaria. There is some evidence, however, that the Pontine 
 district was not all that could be desired even in those times, Seneca advising 
 a friend to avoid the neighbourhood of Ardea as not being very healthy. 
 The invasions of the Goths swept away these villas, with the gardens, the 
 sacred groves, and the high cultivation that surrounded them, the population 
 being driven to secure places in the hills. In the seventh and eighth centuries 
 widespread outbreaks of fever occurred, and serious attempts were made by 
 various Popes, with, however, but slight success, to recolonise and cultivate 
 the desolate country. There can be no doubt but that the reckless destruction 
 of trees, which has gone on steadily ever since it was begun by the Goths, has 
 played a most important part in altering the local conditions and local climate 
 of the country ; and in comparatively recent times the destruction of timber 
 in the mountains has caused the streams which rise in them to become 
 uncontrollable and destructive, converting large areas of low land into bog 
 and swamp, and rendering cultivation difficult and unprofitable. 
 
 A moist soil, particularly if uncultivated, is then an important factor in 
 the causation of malaria, particularly when associated with it there is a high 
 soil temperature (about 65° Fahr.) and impurity of ground air and of soil,-. 
 
MS HYGIENE 
 
 the latter being usually of vegetable origin. The rise or fall of ground water, 
 by causing variations in the amoimt of moisture present, evidently plays an 
 important part in producing or controlling periodical outbreaks of paroxysmal 
 fevers in countries which are liable to malaria. The development of malaria 
 may be coincident with either a rise or a fall of the subsoil water, although 
 Fodor found that, with an increased height of the ground water, malaria 
 died away, while as the soil became drier it again put in an appearance. 
 Thus, in 1887, at Buda-Pesth the soil was driest in the summer and 
 autumn, and it was just at this period of the year that the malaria curve 
 rose highest, a great increase of malaria following on the sinking of the 
 moisture curve relating to a depth of one metre below the surface. After- 
 wards the amount of moisture increased till the middle of September, and 
 malaria fell off from the middle of September to the middle of October, 
 Fodor considering that the difference in time was accounted for by the 
 incubation period of the disease. 
 
 Rainfall, on the other hand, appears to bear a direct relationship to the 
 disease, the malaria curve generally falling during the fall of rain, while during 
 dry weather the curve at once commences to rise. If, however, the malaria 
 curve be compared with the changes going on in the deeper parts of the soil, 
 such as the range of moisture or the fluctuations in the amount of carbon 
 dioxide (and so with fluctuations in the amount of putrefaction going on in the 
 soil), no such connection can be traced. While, however, on the other hand, 
 there is an evident relation between the extent of malarious disease and the 
 amount of moisture in the upper layers of the soil and that of the rainfall, 
 the influence is drawn that the malarial miasma is produced in the most 
 superficial layers of the earth and is independent of decomposition changes 
 in the deeper portions of the soil, thus contrasting markedly with certain other 
 diseases. 
 
 The temperature of the atmosphere also exerts a considerable influence 
 on the prevalence of malaria, which has been carefully worked out by Fodor, 
 who found that a continuance of high temperature for a few days, at any 
 time of the year, was regularly followed in about a fortnight or three weeks 
 by an increase in the number of cases of malaria. A low temperature, how- 
 ever, may not always check the spread of malaria, when other favouring 
 causes are present. The rise of the malaria curve did not immediately follow 
 the rise of summer heat, a certain degree of warmth being apparently needed 
 for the ripening of the germ ; but curiously enough Fodor found that in 
 spring a relatively small amount of warmth sufficed to bring about an in- 
 crease of malaria, his experience on this point being, moreover, supported by 
 other observers. Laboratory experiments also appeared to prove that winter 
 frost, or winter rest, must have some special influence which disposes the 
 germ to develop promptly with a rise of temperature in spring, while later 
 in the year it needs more warmth, and a more prolonged period of such 
 warmth. 
 
 The escape of the miasm of malaria into the air is probably not so much 
 due to the effect of currents of atmospheric air aspirating the soil as to the 
 movements of the ground air caused by differences of density. Thus the 
 ground air tends to rise into the atmosphere more particularly towards the 
 evenmg by reason of its rarity as compared with that of the air above, and it 
 is in the evening and at night in summer and autumn, when the atmosphere 
 is generally polluted with ground air, that malarial infection most often occurs, 
 while by day, when there might be supposed to be more exposure to malarial 
 emanations, infection rarely occurs. Hence also the germ cannot be present 
 in the dust at the surface of the earth, but rather contained by the gi'ound air 
 
THE INFLUENCE OF SOIL ON HEALTH 349 
 
 below the surface. Confirmation of this is found in the fact that in malarious 
 regions the digging up of the soil has frequently caused an epidemic of 
 malaria among those employed in the work of excavation. 
 
 Obstructions to the outflow of the ground water in malarious soils, as 
 occurred during the construction of the Ganges and the Jumna Canals, in 
 which the outflow of a large tract of country was impeded, have often been 
 followed by widespread malarial epidemics. Both in India and in the United 
 States it has also been noticed that obstruction to the natural drainage caused 
 by the blocking of watercourses by mills and dams has been, at any rate in 
 part, the cause of severe and fatal outbreaks of the disease. A rapid rise in 
 the ground-water level may follow on an exceptional rainfall, particularly if 
 the outfall, though sufficient in comparatively dry weather, is inadequate for 
 carrying ofl' an amount of water much in excess of the usual amount. Such 
 an instance occurred at Kurrachee, in Scinde, where the ground is flat and 
 there is no subsoil drainage, but where, as the rainfall is usually small, and 
 the ground dries fast, an epidemic of malaria is an event almost unknown. 
 An unprecedented fall of rain in 1869 was, however, followed by so widespread 
 an outbreak, that the regiment which was stationed there at the time had 
 to be embarked for Madras, as every man had been attacked, although fortu- 
 nately the disease had not been present in a very fatal form. 
 
 Conversely the lowering of the subsoil water due to an increased outflow, 
 the result of extensive drainage operations, has in many places brought about 
 a remarkable reduction of malarial disease. This has been especially notice- 
 able in England, in the counties of Norfolk and Lincolnshire, which within 
 comparatively recent times were noted haunts of malaria, but where, at the 
 present day, owing to the reclaiming by systematic drainage of large areas of 
 marshy country, the disease has practically disappeared. 
 
 Pettenkofer relates a case which is of interest as showing the effect of 
 subsoil drainage on a form of fever alUed to malaria occurring among horses 
 in the royal stables at Munich. Although the sanitary arrangements m 
 each of the two stables appeared to be equally good, and the food, accommo- 
 dation, and attendance in each were apparently similar, horses sufi'ered much 
 more severely in one than in the other. The disease was not infectious, as 
 horses removed from the unhealthy stable did not communicate the disease 
 to those in the more healthy one. After careful investigation, the only cir- 
 cumstance that could be found to account for the difference between the two 
 places was that whereas in the case of the healthy stable the ground water 
 was met with at a depth of between 5 and 6 feet, at the site of the unhealthy 
 stable it rose to within 2^ feet of the surface. Deep drainage was then re- 
 sorted to in the latter situation, and, the level of the ground water having 
 been reduced to the same point as at the healthy site, the disease disap- 
 peared. 
 
 Malarious Soils 
 
 The soil in districts in which malarial fevers are prevalent is usually 
 more or less marshy, or, at any rate, is in the vicinity of extensive marshes, 
 although there are occasional exceptions to this rule. In addition to being- 
 saturated with moisture, such soils also contain a large amount of decaying 
 vegetable matter, and the air above may hold large amounts of carbonic acid, 
 marsh gas (light carburetted hydrogen), sulphuretted hydrogen, and watery 
 vapour, while suspended in it may be found debris of vegetable and animal 
 organic substances, diatoms, infusorise, alg^, and various micro-organisms. 
 These, which are all in the first instance derived from the soil, doubtless in- 
 clude the particular agent to which the propagation of the disease is due^ 
 
.350 HYGIEXE 
 
 but it is quite possible that other of the constituents of air or soil may, by 
 their effect on the system, predispose to the attack of the malarial organism. 
 Thus it has been supposed that the sulphuretted hydrogen which is evolved 
 in great quantities from marshes in certain districts, may give rise to symptoms 
 ■of ana-mia and prostration, -which not unfrequently accompany malarial 
 poisoning. As to the exact chemical conditions of soil which favour the 
 production of malaria, but little is at present known, as exact chemical 
 estimations have not been systematically carried out, but there can be little 
 doubt that the inorganic constituents of the soil have little or nothing to do 
 Avith the problem-, since in difl'erent parts of the world malaria is found to 
 prevail on soils which range from the most impervious forms, such as even 
 granite, to the loosest forms of sand. 
 
 The large amount of vegetable matter found in some malarial soils, 
 amounting to about 30 per cent, in the case of the Tuscan Maremma, and 
 possibly even more in other districts, gives rise, during putrefaction, to various 
 organic acids, named humic, ulmic, crenic, and apocrenic, of the exact 
 chemical constitution of which there is at present but little known, and it 
 may be that these may exert a deleterious influence on health, either by 
 being carried by air or water. In some cases the process of decomposition 
 of the vegetable forms is one which' extends over an almost unlimited time, 
 plants having been found still undestroyed in marshy districts where the 
 same conditions have prevailed for centuries. 
 
 The influence of vegetable decomposition in helping to give rise to attacks 
 of ague is well seen in an instance quoted by Friedel. He mentions that in 
 the Marine Hospital at Swinemiinde, near Stettin, patients who were placed 
 in a certain convalescent ward invariably contracted a bad attack of tertian 
 ague after a residence there of two or three days. No cases occurred in any of 
 the other wards, and the curious incidence of the disease leading to a thorough 
 investigation, it was found that outside the windows of the affected ward 
 was a large rain-water cask full of rotten leaves and brushwood. Water had 
 overflowed from the cask and formed a large stagnant pool alongside the ward 
 into which effluvia had freely found their way, particularly when in the hot 
 weather all doors and windows were kept open at night. This state of aflairs 
 having been attended to, the ward in course of time lost its evil reputation. 
 It is not, of course, suggested that vegetable effluvium is of itself sufficient to 
 cause an attack of malaria, but evidently there were present in this instance 
 circumstances which would be exceptionally favourable for the development 
 of the particular organism immediately concerned. 
 
 On the other hand, ague of a most virulent form has been met with in 
 districts which appeared to be perfectly dry and arid, thus showing that the 
 presence of decomposing vegetable matters is not essential. Thus, according to 
 Hirsch, the tableland of Castile, the plain of the Araxes, and the lofty plateaux 
 of Northern India and Persia are all highly malarial, and even in Italy 
 careful inquiry has apparently proved that some malarial districts are in con- 
 siderable i^art devoid of water and sterile. We have it also on the authority 
 of Dr. William Ferguson, nearly a century ago, that he had observed in- 
 stances in which British troops were attacked with the disease while encamped 
 upon dry sandy soils, both in Holland and in Spain. Friedel and Maclean 
 have laid stress on the development of malaria in Hong Kong and other 
 places situated on hard rock {granitic and metamorphic), particularly where 
 these have become weathered and disintegrated, but in such districts it is 
 quite possible that it is not dependent so much on the actual disintegra- 
 tion of the granite as upon the abundant cryptogamic vegetation which is 
 found in the soil filling up the clefts in the rock. In many instances also in 
 
THE INFLUENCE OF SOIL ON HEALTH 351 
 
 Avhicli malaria lias shown itself in places where the soil was apparently free 
 from moisture, water may have been present, even in considerable quantity 
 in the lower layers of the soil, especially where a substratum of clay or other 
 impermeable material existed, the soil being only saturated up to a certain 
 level. 
 
 Although malarious diseases are doubtless most prevalent in the neigh- 
 bourhood of marshes, these may exist even over considerable areas without 
 paludal fevers making their appearance. This is notably the case in countries 
 like Ireland, which are widely covered with peat bogs, but where malaria is not 
 at all abundant. Moreover, marshes which are regularly overflowed by salt 
 water do not breed the disease, notwithstanding that their surface is exposed 
 for a large part of each day. Even in marshes not exposed to the action of 
 the sea, investigations have shown that malaria is often not developed during 
 the wet part of the year, when the ground is entirely flooded with water, but 
 rather during those seasons at which large parts of it are exposed to the air 
 and so become more or less dry. On the other hand, in Italy it has been 
 noticed that occasionally the overflowing of fresh -water marshes by the sea 
 has caused a considerable development of malaria, but obviously the condi- 
 tions are different to those which obtain in the case of a daily flushing by the 
 tide. 
 
 Many alluvial soils, particularly those which have been recently formed, 
 give out malaria, even though they may not be marshy. This may be due 
 to the fact that they contain more organic matter, which would be especially 
 likely to be the case where they occur in the vicinity of streams, as along the 
 estuaries and deltas of rivers which are for the most part only occasionally 
 ■covered with water. In all such situations, hoAvever, the malarial poison is 
 strictly localised, the interposition of a belt of trees or of a sheet of water 
 being sufficient to protect the inhabitants of neighbouring districts from 
 its influence. Thus, when English troops occupied Walcheren and other 
 parts of Holland, it was several times noticed that only those soldiers who 
 disembarked were attacked by ague, those who remained on board ship, even 
 when in narrow channels, escaping. 
 
 Certain sandy soils, especially when impregnated with a large proportion 
 of iron, have been reputed to be extremely malarious, but the influence of 
 the iron in this connection is more than doubtful, the supposed effect having 
 more probably to be sought in the presence of organic matters, which are 
 often found in large amount, as in the sandy soil of the Laudes, in south- 
 west France. 
 
 The Bacillus and Plasmodium Malarics 
 
 From the evidence that has been brought forward, it appears certain that 
 there is a very close relation between certain soil conditions and the occur- 
 rence of malarial disease, and consequently numerous observers have sought 
 for the presence in malarious soils of some organism which might possess 
 the power of transmitting the disease. Klebs and Tommasi-Crudeh, while 
 engaged on such a series of experiments, found in the soil of the Roman 
 Campagna a distinctive bacillus which they beheve to be the specific cause 
 of malaria. The bacillus, which varies considerably in size, up to the diameter 
 of a red corpuscle of the blood, grows in artificial cultures into twisted 
 threads ; inoculated into rabbits it is stated to produce a febrile disorder ana- 
 logous to malarial fever, while threads and spores may be found in abundance 
 in the spleen and marrow. Marchiafava has described bacilh with end- 
 spores as occurring in the blood of patients suffermg from malaria. 
 
352 HYGIENE 
 
 The latter observer, however, in connection with CelH, has more recently 
 found that pecuhar amoeboid bodies (plasmodia), occasionally showing motile 
 filaments, and often containing granules and black pigment masses, are 
 constantly to be found in the blood in cases of malaria, either free or enclosed 
 within the red corpuscles. These organisms are probably allied to the flagel- 
 lated protozoa. 
 
 Although general interest in this subject was perhaps first roused by the 
 publications of Marchiafava and Celli, who gave the name Plasmodmm 
 vialarice to the organism they found in the blood, it had been previously 
 described by Laveran in Algiers in papers communicated by him to the Paris 
 Academy of ^Medicine in 1881 and 1882, his researches being finally embodied 
 in a large work which he published on the malarial fevers. He found as 
 characteristic elements in the blood of persons attacked with malaria, (1) 
 crescentic pigmented bodies, (2) pigmented bodies in the interior of red cor- 
 puscles, which underwent changes in form, described as amosboid, and (3) a 
 pigmented flagellate organism. He looked upon all these forms as phases in 
 the development of an infusorial organism which he regarded as the germ of 
 the disease. These observations have subsequently been for the most part 
 confirmed by Kichards, Councilman, and Osier. 
 
 Mosso, however, has sought to prove that these bodies resolve themselves 
 into degenerative types of the red blood-corpuscles, in which he is su )ported 
 by Tommasi-Crudeli, who regards the forms in question as the result rather 
 than the cause of malarial disease, and who, moreover, still maintains the 
 pathogenic nature of the bacillus discovered by Klebs and himself. Von 
 Taksch states that he has many times examined the blood of patients 
 suflering from intermittent fever, without ever finding such bodies as those 
 described by Marchiafava, Celli, and others ; but against such merely negative 
 results may be placed the experience of Osier, who examined seventy cases 
 of this disease, in not one of whom did he fail to find the plasmodium. It 
 would appear from his researches, hoAvever, that the organisms concerned 
 assume a greater variety of forms than was previously supposed, which may 
 possibly account for them having been overlooked in some instances. 
 
 Yet another organism has been described by Sakharoff as being present 
 in the blood of malarial patients. This parasite, which may attain enormous 
 proportions, as large as twenty corpuscles together or even larger, consists of a 
 mass of extremely fine protoplasm containing numerous dark roundish sharp - 
 coloured motile granules and a greyish nucleus about the size of two blood- 
 corpuscles. The hgematozoon is capable of transformation into a number 
 of bright homogeneous clear bodies, which are formed by the separating off 
 of protoplasmic processes. In course of time some of them penetrate into 
 the red corpuscles, increase in size, develop pigment granules, and gradually 
 pass into the adult form mentioned above ; while other bodies having a 
 smaller size coalesce to form threads closely resembling the spirochetre of 
 relapsing fever, differing only from the latter in their being somewhat thicker, 
 and in their performing comparatively slower, wave-like movements. The 
 intracorpuscular form he beheves to be identical with Laveran's malarial 
 parasite. 
 
 It will be seen from so many contradictory statements that the question 
 as to what is the specific cause of intermittent fever is not yet satisfactorily 
 solved. Even supposing that these amoeboid forms are invariably present, the 
 question arises. Are they pathogenic or are they merely associated with the 
 disease, which in some way furnishes conditions favourable to their growth ? 
 As evidence of their pathogenic nature may be urged the constancy of their 
 presence, their absence from other healthy individuals in malarial regions^ 
 
THE INFLUENCE OF SOIL ON HEALTH 353 
 
 their destructive influence on the blood-corpuscles, and their abundance in 
 many of the graver forms of the disease. 80 far the presence of these bodies 
 has not been demonstrated hx soil, nor have they yet been cultivated outside 
 the human system, but by inoculation and the intravenous injection of 
 malarial blood containing them, Marchiafava and Celli have succeeded in 
 communicating the disease to other individuals ; but in regions where malaria 
 is prevalent such experiments cannot but be looked upon with suspicion. It 
 should, however, be remembered that h^ematozoa are not uncommon in 
 animals, and as in the rat do not appear to interfere seriously with the health 
 of their host. Under these circumstances the association of a specific form 
 with a definite disease in an animal makes it all the more probable that the 
 species is pathogenic (Osier). 
 
 Golgi has, moreover, recently attempted to prove that the paroxysms of 
 intermittent fevers bear a direct relation to the development of generations 
 of parasites, and that the different developmental periods of different broods 
 are the conditions determining the varying periodicities of the recognised 
 varieties of malaria. He claims that the experienced observer can distinguish 
 by biological and morphological characteristics those organisms which have 
 a life-cycle corresponding with the periodicity of tertian ague from those in 
 which the cycle corresponds with the quartan variety of malarial fever. The 
 endoglobular amoeboid bodies found in tertian fever show much more active 
 movements than those of the quartan form, in which latter these amoeboid 
 changes can only be distinctly observed in the first stage of their development, 
 and never very readily, it being usually necessary to warm the preparation in 
 order to excite them. In quartan fever the affected corpuscles are stated to 
 become shrunken, but to retain their colour in great degree up to the latest 
 phase in their destruction ; while in tertian fever, on the other hand, the 
 parasite which completes its developmental cycle in two days, as opposed to 
 three days in the quartan form, decolourises in an energetic and rapid 
 manner the red blood-corpuscles, which, however, retain their regular outline, 
 appearing in some ca,ses even larger than normal. Finally, the author 
 relates a case, the obscure clinical features of which were explained by his 
 discovery in the blood of the organisms peculiar to both quartan and tertian 
 fever, those of the former variety being most numerous. 
 
 Should further research confirm these observations, there can no longer 
 be any doubt that these parasitic organisms play a most important part in 
 the astiology of malarial fevers, and seeing that, even at the present time, such 
 connection appears, to say the least, more than probable, it is highly desirable 
 that attention should be turned to the more thorough understanding of the 
 Ufe-history of the Plasmodium malaricB and particularly to the question as 
 to whether, under certain conditions, it is capable of living and perhaps of 
 multiplying in the soil of districts favourable to the development of the disease, 
 and also to those circumstances which either encourage or are inimical to its 
 development in the body. Pending more exact knowledge, however, in this 
 drection, there remain other factors in the causation of malaria which must 
 not be lost sight of, as by due attention to them much may be done in pre- 
 venting the appearance or diminishing the virulence of the disease. 
 
 Among such preventive measures must be mentioned thorough and deep 
 drainage, by which the subsoil water is permanently lowered and stagnant 
 sheets of water caused to disappear. The nature of the soil also should be 
 inquired into, and if found to contain much organic matter houses built upon 
 it should be protected by a layer of concrete underneath, to prevent the 
 upward passage of the ground air ; while even greater security in this direction 
 may be obtained by raising buildings off the ground on a series of arches. 
 
 VOL. I. A A 
 
354 HYGIENE 
 
 Malarial efflu\-ium being most dangerous at niglit, jt is well also that the 
 sleeping rooms should be placed at the upper part of houses, as it does not 
 appear to rise beyond a certain height from the ground. Seeing that the 
 presence of much vegetable debris either in the soil or upon it, especially 
 when accompanied by a certain amount of moisture and a warm temperature, 
 tends to favour the development of the malarial agent, it is of importance to 
 remove all masses of decaying vegetation and at the same time prevent 
 putrefactive changes of the soil by providing an outlet for the Avater, either 
 as already suggested by efficient drainage, or by the planting of trees, which 
 by means of their leaves throw off enormous quantities of water in the course 
 of the day. This is specially the case with the Eiicahjptus globulus, which 
 is supposed to be capable of absorbing and evaporating eleven times the 
 rainfall over the area it covers. Next m value from this point of view comes 
 the oak ; so that it is highly desirable that one or the other of these trees 
 should be planted freely in malarious districts. Where this has been already 
 done, considerable effect in the direction of rendering the locality more healthy 
 has been observed, as wh.ai moisture is removed from the soil the malarial 
 organism no longer finds its surroundings favourable for development. Sun- 
 flower plants have a similar effect, but of course in less degree. Occasionally 
 great benefit has been derived from covering the ground with grass, which 
 hinders the ascent of the miasma and at the same time causes the evaporation 
 of a considerable amount of soil moisture. 
 
 Although trees are valuable both by aiding removal of Avater from the 
 soil and also apparently from opposing a barrier to the progress of malaria, 
 the same cannot be said of thick undergrowths of brushwood, which only 
 hinder a proper circulation of air, and at the same time favour extensive 
 decomposition. A remarkable instance of this is seen in the case of a large 
 area of maccliia which lay between the town of Cisterna and the Pontine 
 Marshes. In 1714 it was proposed to cut it down, but this was successfully 
 opposed by Lancisi, the Papal sanitary adviser at the time, on the ground that 
 a barrier or filter was thus opposed to the malarial emanations from the Pontine 
 Marshes. Cisterna at that time was extremely unhealthy, and had a rapidly 
 diminishing population ; but when, about one hundred years after, these woods 
 were cut down, the health of the place at once commenced to improve, and 
 the population increased by rapid strides. 
 
 There is at present little or no evidence to prove that malaria can be 
 caused by drinking-water alone, since, as North has well shown, * the healthiest 
 parts of the city of Eome are supplied by water admittedly the best in the 
 world, and which rises — to take the Acqua di Trevi or Acqua Vergine as an 
 example — on unenclosed land, in springs which bubble up and cover the 
 surface in a locality so unhealthy that to pass several nights there in August 
 might involve risk to life, and certainly to health. There seems to be but 
 little doubt that a supply of good drinking-water is of importance in malarious 
 localities, but it has yet to be shown that in exchanging pond and ditch 
 water for that of springs the inhabitants cease to take a poison into their 
 bodies. The evidence points rather to the fact that by so doing they raise 
 their general health, ai , \ so become less liable to the disease. At all events, 
 proof that the malarial infection can be conveyed by water is wanting, though 
 very largely credited by the natives of countries where the disease prevails.' 
 At the same time, sur ace water particularly should be looked upon with 
 suspicion for drinking purposes, and if only shallow wells are available for 
 the necessary supply, it is well that it should be boiled before being taken 
 into the system. 
 
 Finally, we posses? n quinine a drug which exhibits a remarkable pro- 
 
THE INFLUENCE OF SOIL ON HEALTH 355 
 
 perty in enabling the body to withstand malarial attacks, and it is therefore 
 only prudent to make constant use of it if residence in or passage through 
 countries where the disease is prevalent be unavoidable. 
 
 Eheumatism and Neuralgia 
 
 It is probably only in so far as the climate of a locality may be affected 
 by peculiarities of the soil, such as elevation, configuration, the kind of rock, 
 and the physical characters, that we have to take this factor into account in 
 the aetiology of rheumatism. Thus it is well known that the disease evinces 
 a preference for open basins and plateaux exposed to the wind, for damp 
 and deeply cleft valleys, and for sea-coasts or the shores of great rivers. 
 
 Dampness of soil may, however, predispose to this disease, from the fact 
 that it renders it cold ; and this will be the more likely to be the case at low 
 elevations, and where there is an impermeable subsoil such as clay ; but no 
 sweeping assertion can be made on this point, as the necessary data for the 
 institution of the comparative frequency of the disease on different kinds of 
 soil are unfortunately wanting. 
 
 Neuralgia, like rheumatism, is doubtless most often the outcome of a con- 
 stitutional state dependent on influences from without, and ultimately trace- 
 able to the circumstances of the locality or of the season, including climate, 
 weather, and soil ; but our knowledge of the geographical distribution of 
 the neuralgias is too defective to let us decide with certainty how far influ- 
 ences of the latter kind may determine the prevalence of the malady at 
 various parts of the world (Hirsch). It is noteworthy, however, that Valleia 
 has shown that neuralgias of the rheumatic kind are, along with other 
 rheumatic disorders, commonest within the temperate zone in the cold and 
 wet seasons of the year, while in tropical countries they reach their maximum 
 when the rains begin, and again when they cease. Foltz, Lidell, and Gib- 
 son have also called attention to the fact that those states of soil which are 
 favourable to malaria may also predispose to neuralgia, while Hirsch states 
 that Egypt and New Caledonia, which are remarkable for their relative or 
 absolute immunity from malarial fevers and for the steadiness of their climate 
 and weather, are strikingly free from this disease. 
 
 Phthisis 
 
 Tuberculosis, or phthisis, is a micro-parasitic and possibly infectious dis- 
 ease, which has been proved to have an intimate relation to dampness of 
 soil. It causes an average of 50,000 deaths annually in England at the 
 present time, or more nearly 70,000 per annum, if there be included with it 
 deaths registered as occurring from tabes mesenterica, tubercular meningitis, 
 and ' other forms of tubercular disease and scrofula.' 
 
 In presenting his report for 1858 to the President of the General Board 
 of Health, Mr. Simon, referring to a report by Dr. Greenhow on the pre- 
 vention of pulmonary phthisis, stated that ' pulmonary affections, including 
 phthisis, cause very nearly a quarter of the annual mortahty of England. 
 Every 100,000 of our population yields on an average 552 annual victims to 
 this deadly class of disorder.' He also expressed the opinion that pulmonary 
 phthisis then killed, as now, on an average more than 50,000 persons 
 annually in this country ; so that, although the total population has enor- 
 mously increased since that time, the number of deaths has remained 
 stationary. This improvement is shown in another and better manner by 
 comparing mortality statistics in relation to death-rate per unit of popula- 
 tion, as in the following table extracted from the Kegistrar-General's Forty- 
 
 aa2 
 
356 
 
 HYGIEXE 
 
 fifth Annual Eeport, ^'liicli shows the annual mortality per million from 
 ' phthisis ' at all ages, and at certain typical ages in both sexes the last three 
 decennia : — 
 
 Phthisis Ml England and Wales 
 
 Tears 
 
 All ages 
 
 15— 
 
 20- 
 
 25 — 
 
 35- 
 
 1851-60 
 1861-70 
 1871-80 
 
 2,679 
 2,475 
 2,116 
 
 2,961 
 2,651 
 2,036 
 
 4,181 
 3,928 
 3.117 
 
 4,317 
 4,243 
 3,619 
 
 4,091 
 4,026 
 3,745 
 
 As a result of his investigation Dr. Greenhow showed, among other 
 things, that ' in proportion as the male and female populations are severally 
 attracted to indoor branches of industry, in such proportion, other things 
 being equal, their respective death-rates are increased,' the evil eflect of cer- 
 tain industries, of faulty ventilation, and of overcrowding being also shown 
 to exert a considerable influence in inducing the disease. Notwithstanding 
 such deleterious influences, however, the decrease in the phthisis death-rate 
 has been fairly continuous, so that some other factor must have come into 
 play within comparatively recent years. 
 
 It was, hoAvever, reserved for Dr. Buchanan to bring to light a most 
 important and unexpected factor in the aetiology of this disease, which goes 
 far to explain the reduction in the death-rate spoken of above. In 1865-66 
 he undertook an inquiry, the object of which was to ascertain what had been 
 the results obtained by local authorities, who by means of such works as 
 water supply and sewerage had attempted to improve the sanitary condition 
 of the districts mider their control. One main purpose of the inquiry was ' that 
 the then Central Public Health Authority should fulfil one of the principal 
 duties expected of it by making new local experiences conducive to general 
 enlightenment ; ' and this object was, in one important respect, attained in 
 a direction which is best shown in the resume of the subject given by Mr. 
 Simon in his Annual Eeport for 1866. He there says : ' These columns,' 
 referring to Dr. Buchanan's report, ' appear to indicate a partial dependence 
 of pulmonary phthisis on some of the unwholesome conditions which have 
 been removed. And when detailed examination is made of the cases which 
 give that indication, and they are compared with the different class where 
 phthisis has not lessened its amount, the novel and most important conclu- 
 sion suggests itself that the drying of soil which has in most cases accom- 
 panied the laying of main sewers in the improved towns has led to the 
 diminution, more or less considerable, of phthisis. The facts which are yet 
 in evidence seem most strongly to support this conclusion, which, should it 
 be substantiated, will constitute a very valuable discovery evolved by Dr. 
 Buchanan from the inquiries here reported on. ... It will be seen that the 
 reduction of phthisis where certam works have been executed is far too large 
 and far too general to be regarded as an accidental coincidence. The re- 
 duction, namely, on the death-rates by phthisis in the first fifteen towns in 
 Dr. Buchanan's table are as follows : Salisbury, 49 per cent, of its previous 
 rate ; Ely, 47 per cent. ; Eugby, 43 ; Banbury, 41 ; Worthing, 36 ; Maccles- 
 field, 31 ; Leicester, 32 ; Newport, 32 ; Cheltenham, 26 ; Bristol, 22 ; Dover, 
 20 ; Warwick, 19 ; Croydon, 17 ; Cardiff, 17 ; Merthyr, 11. And the fact 
 that in some of these cases the diminished fatality of phthisis is by far the 
 largest amendment, if not the only one, which has taken place in the local 
 health becomes extremely interesting and significant when the circumstance 
 is remembered that works of sewerage, by which the drying of the soil is 
 
TEE INFLUENCE OF SOIL ON HEALTH 357 
 
 effected, must always of necessity precede, an4 do indeed sometimes precede 
 by years, the accomplishment of other objects (house-drainage, abolition of 
 cesspools, and so forth) on which the cessation of various other diseases is 
 dependent. Thus, as regards the two largest populations concerned in this 
 question — those of Bristol and Leicester — no doubt the comparative smallness 
 of effect hitherto produced on the general and diarrhooal death-rates of these 
 towns may (so far as it is not fallacious) be referred to the shortness of time 
 for which finished constructions have been at work for the detailed dispol- 
 lution of houses and their dependencies ; but a reduction already of a sixth 
 in the phthisis mortality of Bristol and a reduction of a fourth in the phthisis 
 mortality of Leicester are apparently connected with the fact that in both 
 towns main sewerage on a large scale, with more or less drying of soil, has 
 •existed in comparison for many years. And Eugby, which, long as it has 
 been at work, has not yet succeeded in getting rid of endemic diarrhoea and 
 typhoid fever, shows at least this result of its main drainage works, that its 
 phthisis mortality has fallen 43 per cent.' 
 
 In his report for the following year, 1867, Mr. Simon adds : ' The above 
 facts, though not enough in themselves to prove as certain the very important 
 setiological relation which they suggested, were at least amply sufficient to 
 show that a very promising line of inquiry had been opened.' In consequence 
 of the vast importance of the subject, Dr. Buchanan had continued his inves- 
 tigation, and given the results at which he had arrived in a report, presenting 
 an elaborate examination of the distribution of phthisis, as compared with 
 variations of soil, in the three south-eastern counties of England, beyond the 
 limits of the metropolis, which apparently confirmed beyond all question the 
 conclusion previously suggested, that dampness of soil is an important cause 
 of phthisis to the population living upon the soil. 
 
 The reason for the counties of Surrey, Kent, and Essex being the only 
 ■ones included in the investigation was that the Geological Survey of England, 
 although at that time advancing to completeness in its records of the great 
 formations of the country, had mapped the minute surface geology in these 
 counties only. It was evident that surface peculiarities would require to be 
 ' taken into account quite as much as the great divisions of the geologist ; that 
 brick earth, drift gravel, river alluvium, and the like, have an importance in 
 themselves quite apart from the character of the larger formations over which 
 they lie.' 
 
 The three south-eastern counties, therefore, formed the only area where 
 the survey then afforded materials for profitable detailed examination of the 
 soil as affecting the health of residents upon it. 
 
 The inquiry was carried out by, first, ascertaining the true phthisis-rate 
 ■of the population, and in the second place noting the numbers of the popula- 
 tion in each district that were found ' living upon various kinds of soil and 
 under various topographical conditions.' The results of these two separate 
 lines of investigation were then brought together and statistically com- 
 pared. 
 
 The results of the inquiry are shown in the following general conclusions 
 with which Dr. Buchanan summarised his report : — 
 
 1. Within the counties of Surrey, Kent, and Sussex there is, broadly 
 speaking, less phthisis among populations living on pervious soils than among 
 populations living on impervious soils. 
 
 2. Within the same counties there is less phthisis among populations 
 living on high-lying pervious soils than among populations hving on low- 
 lying pervious soils. 
 
 3. Within the same counties there is less phthisis among populations 
 
858 HYGIENE 
 
 living on sloping imperious soils than among populations living on flat im- 
 pervious soils. 
 
 4. The connection between soil and phthisis has been established in this 
 
 inquiry : 
 
 (a) By the existence of general agreement in phthisis mortality between 
 districts that have common geological and topographical features of a nature 
 to aiiect the water-holding quality of the soil. 
 
 {b) By the existence of a general disagreement between districts that 
 are differently circumstanced in regard of such features. 
 
 (c) By the discovery of pretty regular concomitancy in the fluctuation of 
 the two conditions — from much phthisis with much wetness of soil to httlo 
 phthisis with little wetness of soil. 
 
 (d) By the observation that phthisis has been greatly reduced in towns 
 where the water of the soil has been artificially removed, and that it has not 
 been reduced in other towns where the soil has not been dried. 
 
 5. The whole of the foregoing conclusions combine into one, which may 
 now be affirmed generally, and not only of particular districts, that wetness of 
 soil is a cause of phthisis. . . . 
 
 6. No other circumstance can be detected, after careful consideration of 
 the materials collected, that coincides on any large scale with the greater or 
 less prevalence of phthisis, except the one condition of soil. 
 
 Dr. Buchanan had not long completed his investigations, when it became 
 known in England that Dr. Bowditch, of Boston, U.S., had been working on 
 similar lines in America for some time previously, and that he had arrived 
 at identical conclusions. In an address dehvered at the annual meeting of 
 the Massachusetts Medical Society in 18G2, and afterwards pubhshed, he drew 
 attention, and not for the first time, to the remarkable inequality with which 
 he found phthisis to be distributed in the States, and to the connection of 
 this inequality with differences of moisture of soil, and he submitted the two 
 following propositions as containing the essential results of a very extended 
 inquiry : — 
 
 ' First : A residence in or near a damp soil, whether that dampness be 
 inherent in the soil itself or caused by percolation from adjacent ponds, 
 rivers, meadows, marshes, or springy soils, is one of the principal causes of 
 consumption in Massachusetts, probably in New England, and possibly in 
 other portions of the globe. 
 
 ' Second : Consumption can be checked in its career, and possibly — nay 
 probably — prevented in some instances by attention to this law.' 
 
 He not only proved apparently ' that dampness of the soil of any township 
 or locality is intimately connected, and probably as cause and effect, with the 
 prevalence of consumption in that township or locality,' but even also adduced 
 particular instances as tending to prove that ' some houses may become foci 
 of consumption when others, but slightly removed from them but on a drier 
 soil, almost wholly escape.' 
 
 Although, therefore, the priority of discovermg a connection between soil- 
 dampness and the phthisis rate is midoubtedly due to Dr. Bowditch, the 
 investigations of Dr. Buchanan are none the less valuable, he having quite 
 independently, and probably upon more complete data, established the preva- 
 lence of a similar relation in this country ; and, indeed, the researches of both 
 observers obtain additional weight from the fact that they were arrived at 
 almost simultaneously, each observer being entirely unbiassed by the other. 
 
 It is also worthy of note, as affording still further support to the results 
 thus obtained both in England and America, that the Eegistrar-General for 
 Scotland m his Seventh Annual Report, adverting to Dr. Bowditch's work^ 
 
THE INFLUENCE OF SOIL ON HEALTH 359 
 
 stated that, in liis opinion, the phthisis mortahty statistics in Scotland 
 furnished evidence to the same general effect : among the principal towns, 
 Leith and Edinburgh, the most Ire.e from consumption, having also the driest 
 sites, while, on the other hand, Glasgow and Greenock, the most ravaged by 
 this disease, were, beyond all comparison, situated on the dampest sites. The 
 remarkable freedom from consumption of the Capo of Good Hope and South 
 Africa generally, as also of Egypt, as compared with the comparatively high 
 mortality from it in the moist climate of Great Britain, is a fact which also 
 points in the same direction. It has been shown, moreover, in America, by 
 Dr. Andrews, that cases of phthisis are most abundant near the sea, and 
 diminish with increasing distance from it, so that while in Central North 
 America the proportion of deaths from consumption to deaths from all causes 
 is least, the ratio gradually rises as we pass towards either the Atlantic or 
 Pacific Ocean, the numbers being, however, greater on the eastern than on 
 the western coast, while on the northern sea-boards there is a similar increase 
 over districts situated more towards the south. 
 
 Hence we may fairly consider the proposition affirming a close relation 
 between tubercular disease and moisture of locality to be of practically uni- 
 versal application. 
 
 A certain amount of opposition has, however, been offered to these views, 
 notably, by Dr. Charles Kelly, who, in his Eeport for 1879, on the Combined 
 Sanitary District of West Sussex, has thrown doubt on these conclusions, 
 basing his statements on certain data collected within that rural area. He 
 there states that, although the phthisis death-rate had been distinctly low- 
 ered during immediately preceding years, there had been no contemporary 
 improvements in the system of drainage of the soil to account for the altera- 
 tion. Dr. Thorne Thorne, on the other hand, has indicated that the large 
 amount of agricultural drainage which had then already been effected through- 
 out the kingdom had been of a sort to produce a similar result in rural 
 districts to that brought about by sanitary drainage in towns, and he at the 
 same time calls attention to the fact that Dr. Kelly offers no explanation of 
 the striking and definite relation shown by Dr. Buchanan to have existed 
 between the amount of diminution of phthisis death-rate and the extent and 
 permanence of the lowering of subsoil water. In the same report Dr. Kelly 
 states his belief that a number of changes, social as well as sanitary, includ- 
 ing among them the improved state of the cottages, the rise of wages leading- 
 to the children being better clothed and fed, the increase in railway com- 
 munication, which tends to diminish intermarriage and to cause more in- 
 terchange of population, have all had their share in the undoubted improve- 
 ment which has taken place. 
 
 In a later report (1887) Dr. Kelly again returns to the subject, and gives 
 a series of comparison tables for the ten years 1876-86 relating to the com- 
 bined district of West Sussex. He first classifies the different soils into three 
 classes : — 
 
 1. The pervious soils, which include the upper and lower green sands, the 
 chalk, and the lower Tunbridge Wells sands. 
 
 2. The retentive soils, which include the Weald clay, the clayey beds of 
 the lower green sand, and the gault. 
 
 3. The vioderately pervious soils, including a long strip of nearly level 
 land between the South Downs and the sea, where the chalk is covered 
 for a depth of fifteen to fifty feet with loam and brick earth. The surface 
 of this soil rises gently from the sea towards the Downs, so that, although 
 in some parts the clays are retentive, yet the slope towards the sea enables 
 surface water to flow away readily, except in some of the low-lying brooklands. 
 
3G0 
 
 HYGIENE 
 
 This classification is followed by a table showing the various death-rates 
 on these different soils : — 
 
 Nature of soil 
 
 Population 
 
 1876-86 
 Death-rate per 1,000,000 living at all ages from 
 
 
 Phthisis 
 
 Lung diseases 
 
 All causes 
 
 Pervious . 
 Moderately pervious 
 Ketentive . 
 
 West Sussex . 
 
 33,820 
 29,640 
 23,530 
 
 86,990 
 
 1,514 
 1,467 
 1,542 
 
 1,506 
 
 2,131 
 1,892 
 2,583 
 
 2,172 
 
 14,852 
 14,463 
 14,942 
 
 14,741 
 
 These figures appear to show that the mortality from lung diseases varies 
 considerably, being much higher or retentive than on porous soils, while 
 the mortahty from what is now registered as phthisis and from all causes is 
 very nearly the same on each variety of soil. 
 
 It should, however, be remembered that in this West Sussex district, as 
 indeed thi-oughout EDgland, there has been a great reduction in the phthisis 
 mortality since Dr. Buchanan's inquiry into the subject for the decade 
 1851-60. Moreover, the assumption runs through all Dr. Kelly's arguments 
 that the relative wetness of soil in the six registration districts with which he 
 is concerned remams in later times as it was in 1851-60. What his statistics 
 may be taken to show is that, all the varieties of soil being now equally 
 healthy, the cause of the phthisis deaths which still occur has to be sought for 
 in some other direction. 
 
 Not a particle of evidence is adduced on this point, nor is the operation 
 of sanitary measures upon the soil in the several districts even spoken of. 
 In his Sixth Annual Keport (1879), indeed, it is stated that there has been 
 * no change whatever in the drainage ' of these rural districts, but this state- 
 ment is too bald to be of much import. The assumption, too, pervades 
 his argument that soil wetness is the cause of phthisis, whereas all that has 
 ever been claimed for it in this connection is that it is a cause. 
 
 The relations of phthisis to season and temperature are somewhat obscure, 
 as might be expected, seeing that the duration of the disease may extend over 
 not only months, but years. Buchan and Mitchell, however, have shown 
 that mortality from tabes shows a definite relation to the temperature, the 
 maximum extending, like that of summer diarrhoea, from the middle of July 
 to the middle of September, while the absolute minimum is foimd by them 
 to last from the end of December to the beginning of February. 
 
 According to these observers, also, a curve of the seasonal relations of 
 phthisis mortality shows that ' the absolute minimum occurs in the last week 
 of September, after which it begins steadily to rise ; in the middle of November 
 it rises still more rapidly ; during the last three weeks of December it falls 
 a Httle ; rises again in the beginning of the year, and remains steady until 
 the second week of March, when it rises to the annual maximum during 
 March, April, and May. From the middle of July to the middle of November 
 it is below the average. This is one of the most constant curves in its main 
 features from year to year.' 
 
 The Bacillus Tuberculosis 
 To Koch is undoubtedly due the honour of having discovered the micro- 
 parasite which is pathognomonic of the disease under consideration. Prior 
 to the pubhcation of his researches, indeed, numerous observers had described 
 various micrococci and other organisms which they had found in tuberculous 
 material, but their significance has not been confirmed by subsequent re- 
 search. 
 
p. 
 
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THE INFLUENCE OF SOIL ON HEALTH 361 
 
 According to Koch, the tubercle bacilli appear in the form of rods, the 
 length of which is usually equal to that of half a red blood-corpuscle, although 
 this may vary somewhat with the method of staining employed. They are 
 very thin and rounded at the ends. They may be straight, but more com- 
 monly are shghtly curved, and as they often occur in pairs, the double curve 
 seen in such a case may suggest the notion of the commencement of a spiral ; 
 these appearances, together with their size, being sufficient to differentiate 
 them from other bacilli which most nearly resemble them. 
 
 "When first the tubercle bacillus was discovered, it was thought the 
 invasion of the tissues by the micro-organism was the cause of the develop- 
 ment of phthisis, but of late the opinion has been gradually gaining ground 
 that the bacillus, the spores of which must be abundantly present in the air 
 (and possibly in the soil}, particularly in certainly localities, merely finds a 
 fitting nidus in tissues of a lessened power of resistance, whether this be 
 acquired or be due to hereditary taint. The multifarious forms in which 
 tuberculosis presents itself, both in man and in the lower animals, would 
 certainly appear to support this view, which, if it be confirmed by subsequent 
 observations, will necessitate further research in other directions to eluci- 
 date the true fetiology of the disease. Seeing, however, that the bacilli may 
 almost invariably be found not only in affected tissues, but also in the sputum 
 in cases of tuberculosis of the lungs, their detection will always form a point 
 of considerable diagnostic importance, so much so indeed, that to use Koch's 
 own words, ' A doctor who shall neglect to diagnose phthisis in its earliest 
 stage by all methods at his command, especially by examining the sputum, 
 will be guilty of the most serious neglect of his patient.' 
 
 In the light of our present knowledge of the subject, the efforts of 
 preventive medicine must be directed in the first place to the removal of 
 those conditions which appear to bring about a tendency to phthisis, such as 
 dampness of soil and of dwellings, overcrowding, and possibly the con- 
 sumption of the milk of diseased cows and of tuberculous meat. 
 
 At the same time, contamination of the soil and air by the sputum of 
 tuberculous patients should receive due attention, this bemg effected as far 
 as possible by its reception on paper or rags, which should be immediately 
 burned, or into spittoons containing some powerful disinfectant. The 
 removal of soil-dampness is of course only to be carried out by means of effi- 
 cient drainage operations, this being a problem for the engineer rather than 
 the medical officer of health. 
 
 The maps are copied from those appended to Dr. Buchanan's report on the distribu- 
 tion of phthisis as affected by dampness of soil, contained in the Tenth Eeport of the 
 Medical Officer of the Privy Council (1867). (Plates IV. and V.) 
 
 Plate IV. shows the broad geological features of the district investigated ; the distribu- 
 tion of the main formations, of the broader tracts of alluvium, and of the more important 
 surface coverings of gravel and the like being exhibited in a very exact and reliable way. 
 From its scale, however, many points cannot be demonstrated upon it, thus (1) narrow 
 tracts of alluvium along streams are not shown ; (2) brick-earth is not separated from 
 gravel ; (3) the divisions of the Bagshot beds are not given — they are of small moment ; 
 
 (4) the divisions of the Lower Greensand are not shown, and, what is more important, 
 
 (5) the divisions of the Hastings beds into sands and clay is not made ; these divisions 
 ^re made in nature by no long and well-defined boundaries, but by very irregular and 
 multitudinous lines which could not be exhibited on this small map ; (6) faults are not 
 marked, and (7) of the formations that are shown, very small detached patches are, from 
 the necessity of the case, omitted. 
 
 Plate V. shows the registration districts of Kent, Surrey, and Sussex, numbered in the 
 order of their phthisis death-rate, as shown in the table appended, which is copied from 
 Dr. Buchanan's report. Of these the statistics relating to those numbered 1, 2, 8, 14, 23, 
 27, 31 and 41 are unreliable, for various reasons, such as the number of invalid visitors 
 or the migratory nature of the population. 
 
3G2 
 
 HYGIENE 
 
 Registration Districts in the Order of their Proper Mortality from Cojiszcmption, 
 
 {See Ma2)s) 
 
 1. Sheppey 
 
 2. Hastings 
 
 3. Dartfoid 
 
 4. Epsom 
 
 5. Milton 
 
 6. Godstone 
 
 7. North Aylesford 
 
 8. Thanet 
 
 9. Dover 
 
 10. Bromley 
 
 11. StejTiinR 
 
 12. Chertsey 
 
 13. Croydon 
 
 14. Hoo 
 
 15. Cranbrook 
 
 16. Eichmond 
 
 17. Kingston 
 
 18. Elham 
 
 19. Blean 
 
 20. Bridge 
 
 21. Gravesend 
 
 22. East Grinstead 
 
 23. Tunbridge 
 
 24. Eeigate 
 
 25. Eastbourne 
 20. Farnham 
 
 27. Med way 
 
 28. Hambledon 
 
 29. Battle 
 
 30. Canterbury 
 
 31. Eomney Marsh 
 
 32. Hollingbourne 
 
 33. Mailing 
 
 34. East Ashford 
 
 35. Sevenoaks 
 
 36. Guildford 
 
 37. Farnborough 
 
 38. Eastry 
 
 39. Faversham 
 
 40. Eye 
 
 41. Brighton 
 
 42. Maidstone 
 
 43. Cucktield 
 
 44. Dorking 
 
 45. Uckfield 
 
 46. Hailsham 
 
 47. Ticehurst 
 
 48. Worthing 
 
 49. West Ashford 
 
 50. Lewes 
 
 51. Tenterden 
 
 52. Horsham 
 
 53. Westhampnett 
 
 54. Midhurst 
 
 55. Thakeham 
 
 56. Petworth 
 
 57. Westbourne 
 
 58. Chichester 
 
 DiAEEHCEA 
 
 In late summer and early autumn diarrhoea is a disease which is very apt 
 to prevail epidemically, rural districts with a scattered population being, how- 
 ever, less alt'ected than large densely populated towns. As a fatal disease it is 
 conlined almost entirely to children under five years of age, of whom thousands 
 are swept away annually by what Fodor truly terms ' the infants' destroying 
 angel ; ' but it is a mistake to suppose that adults are not affected, since of 
 24,157 attacks recorded in Leicester during the last four years (1885-1889) 
 16,506 were among persons over ten years of age. 
 
 The subject was carefully investigated in 1859 by Dr. Greenhow, who 
 arrived at the conclusion that in those places where it prevailed most 
 severely, a local cause could usually be traced, consisting either of a tainting 
 of the air with the products of decomposition of organic matters, particularly 
 of human excrement, or of a contamination of the water-supply. These results, 
 however, have not been by any means corroborated in subsequent inquiries ; 
 other conditions, such as temperature of the air and of the soil and the 
 amount of rainfall, having gradually come to be considered of more impor- 
 tance. Organic contamination of both soil and water may, it has been found, 
 exist to a considerable extent without the necessary supervention of summer 
 diarrhoea, provided that other circumstances are unfavourable. 
 
 The seasonal curve of diarrhoea shows that the mortality usually begins 
 to increase about the middle of June, rising rapidly to a maximum at the end of 
 July or beginning of August, and falling somewhat less rapidly during August. 
 September, and October. Atmospheric heat is by no means an essential 
 factor in the production of this disease, however, since it is never, even in its 
 fatal forms, really absent from the population at any period of the year, being 
 met with in winter as well as summer, although not nearly to the same extent. 
 The disproportionate mortality during the summer is principally owing to the 
 disproportionate rate of attacks among a population, the fatality of a given 
 number of attacks in the one and the other season being not more diverse 
 than 3 : 1 in the summer as compared with the winter. In the second place 
 the epidemic development of the malady does not always correspond with the 
 commencement of summer atmospheric temperature, especially when the 
 latter is exceptionally early. Moreover, as Fodor has shown as the result of 
 his observations at Buda-Pesth, there may be no apparent connection between 
 the air temperature and the curve of diarrhoea, since, while in the summer 
 of 1863, which was very warm, the number of cases was small, in the follow- 
 
THE INFLUENCE OF SOIL ON HEALTH 3G3 
 
 ing year, which was much cooler, the disease was very widespread. He 
 states also the disease usually asserts itself on a sudden, but only after a 
 certain degree of warmth has continued for a longer or shorter period, ' as 
 if,' he adds, ' the virus in the soil had first to ripen,' Turner also, in the 
 ' Medical Times and Gazette ' for 1879, endeavoured to show that a tempera- 
 ture of over 60° F. must last at least three weeks before diarrhoea becomes 
 excessive. Again, the percentage of deaths from this disease is not only 
 much higher in towns than it is in villages, but in some cities and in certain 
 parts of cities the disease is much more prevalent, although there is no 
 difference of temperature to account for it. Diarrhoeal epidemicity, therefore, 
 and the atmospheric temperature by no means invariably correspond, although 
 not unfrequently the highest point of prevalence of the disease may occur at 
 about the time when the highest summer temperature is reached, or a little 
 later. There is an even more remarkable lack of correspondence between 
 the decline of the two things, for although the prevalence of diarrhoea lessens 
 with the falling temperature in October and September, it does not do so 
 proportionately to the fall in the air temperature, the extent to which it is 
 present among the population being considerably greater than it would be 
 with a similar temperature in the earlier months of the year. 
 
 In the same way it is not possible to trace any direct connection between 
 a tendency to putrefactive changes in articles of food and drink, such as 
 might, in certain cases, be expected to occur with a high temperature, and 
 the prevalence of diarrhoea. Milk particularly is very liable to undergo de- 
 composition in warm weather, and it has been thought that its extensive use 
 as a food for young children, especially those only recently weaned, might 
 account in great measure for the special incidence of the disease during the 
 first few years of life, but this view is obviously no longer tenable, except in 
 so far as that such a condition of things might predispose the system to 
 suffer more severely when attacked. 
 
 Dr. Ballard has recently pointed out that there is, on the other hand, a 
 very considerable correspondence between the prevalence of diarrhoea epi- 
 demics and the temperature of the earth at a distance of four feet from the 
 surface. In a diarrhoea town, no matter what the temperature of the atmo- 
 sphere may have been in the latter part of the spring quarter, in May or 
 June, or even in July, the epidemicity does not become markedly manifest 
 until the thermometer, four feet below the surface, shows a temperature of 
 about 56° F. (13° C). He shows that when this temperature is reached, and 
 so long as it is maintained, the epidemic prevalence continues there, and 
 commonly reaches its acme about the same time as the four-feet earth 
 temperature. An exception is occasionally seen to this, the prevalence of 
 the disease commencing to decline before the four-feet earth temperature has 
 reached its highest point. This is noticeable when the earth temperature 
 has remained for some time at about 56° F., such sustained high tempera- 
 ture of the earth appearing capable of exhausting the potency for e'sdl of the 
 soil factor of the disease, whatever it may be, before the extreme elevation 
 has been reached. The decline of an epidemic again shows little or no rela- 
 tion to that of the air temperature, but often a very close connection with 
 the extremely gradual and slower fall of the four-feet soil temperature, so 
 that, although the atmospheric temperature may be much lower in autumn 
 than in summer, the prevalence of diarrhoea may be more marked. It 
 requires a continuance of a fairly high air temperature for a considerable 
 period before the soil temperature, at a depth of four feet, reaches 56° F., 
 and until this point is reached, the cause of the disease appears to be dormant ; 
 but once that temperature in the soil is touched in a diarrhoea toTSTi, an epi- 
 
364 
 
 HYGIENE 
 
 demic arises more or less explosively, declining later in a mucli more 
 leisurely manner, so that the different relation of air temperature to the 
 prevalence of diarrhoea in the spring, and in the later months of the year, 
 is still more marked than if the summer and autumn months be compared. 
 
 Dr. Tomldns, of Leicester, who for several years has recorded the tempera- 
 ture of the earth at one foot and four feet levels during the warm months, 
 shows very conclusively that it is not till the temperature of the earth , at a 
 depth of one foot, has reached about 00° F. (15°-53 C), and stands at some 
 4° F. less than this at four feet, that diarrhoea begins to prevail to any marked 
 extent. He, however, regards the temperature at a depth of one foot as the 
 most significant. 
 
 Reviewing in 188G-88 statistics of diarrhoea and infant mortality in the 
 city of Buffalo, Snow found that thirty-one per cent, of the deaths under 
 one year of age were caused by acute intestinal disease. He found that 
 there w^as no constant relation betw^een a high average atmospheric tempera- 
 ture and the largest number of fatal cases, but that, on the other hand, 
 greatest diarrhoea mortality occurred always in the month in which the 
 minimum atmospheric temperature attained its highest average range, and 
 this altogether independent of the circumstance that such month was not 
 necessarily that of maximum highest mean average temperature. And this 
 fact would appear not out of harmony with the results of Ballard's researches. 
 The following table gi\^ng the number of deaths in Buffalo for July and 
 August for each of three years, with the mean average temperature and the 
 average minimum temperature, illustrates the fact upon which Dr. Snow 
 insists : — 
 
 Table of Temperatures at Buffalo for July aiid August 1886, 1887, and 1888. 
 
 
 Diarrhoea. 
 
 Jlean average 
 
 temperature of 
 
 Average minimum night tem- 
 
 
 Deaths 
 
 atmosphere for each month 
 
 peratm-e for each month 
 
 1886, July 
 
 144 
 
 69-4° F. 
 
 20-77° C. 
 
 60-3° F. 
 
 15-72° C. 
 
 „ August . 
 
 141 
 
 67-2 
 
 19-55 
 
 60-3 
 
 15-72 
 
 1887, July 
 
 265 
 
 08-4 
 
 20-22 
 
 67-5 
 
 19-72 
 
 „ August . 
 
 168 
 
 74-6 
 
 23-66 
 
 64-2 
 
 17-88 
 
 1 1888, July 
 
 189 
 
 67-4 
 
 19-66 
 
 59-6 
 
 15-33 
 
 j „ August . 
 
 212 
 
 67-4 
 
 19-66 
 
 64-0 
 
 17-77 
 
 A study of meteorological conditions during two of these years seemed to 
 show that cholera infantum is much more prevalent in a dry than in a wet 
 season, this possibly being in turn due to the fact that in a dry season the 
 temperature of the soil would be likely, other things being equal, to reach a 
 higher point than in the opposite case. This same fact has been insisted on 
 by Fodor, who states, as the result of his experience, that an exceptional rain- 
 fall occurring in the midst of even the most violent epidemic will be followed, 
 after from eight to ten days, by a large reduction in the death-rate, but that on 
 cessation of the rain the disease may assert itself afresh. The results of Power's 
 investigations at Leicester are also in harmony with this statement. 
 
 Lithe table compiled by Dawson Williams (p. 365), the two years 1887 and 
 1888 are chosen for comparison, because 1887 was exceptionally warm and 
 dry, while 1888 was unusually cold and wet. The table shows also that the 
 endemic prevalence of fatal diarrhoea in London may occur with a lower air 
 temperature than 60° F. 
 
 A certain amount of moisture of the soil, however, is favourable to the 
 prevalence of diarrhoea, and as warmth is also a necessary factor, it is highly 
 probable that it is to microphytic processes going on in the upper layers of 
 the soil that the epidemic spread of the disease is due. This would afford an 
 explanation of the fact that summer diarrhoea is, especially, a disease of cities 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 365 
 
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3G6 HYGIENE 
 
 having a polluted soil, although the organic matter present need not necessarily 
 be of a faecal or excremental nature. Diarrhceal mortality is apt to be high 
 where dAvelliugs are built upon made ground, upon the refuse of towns or market 
 gardens, or where the soil is fouled by the escape of sewage from imperfect 
 drains, sewers, or cesspits, or by soakage from midden-heaps. It is therefore 
 to be found most prevalent in those parts of towns where the soil is most 
 polluted, as in Leicester, which has the unenviable notoriety of the highest 
 diarrheal mortality of any of the large towns of En^dand, those parts in 
 which the soil is ' made ' accounting for the larger proportion of the fatal cases. 
 
 The association of high diarrhctal epidemicity with certain geological 
 characters of the soil is another important point for the elucidation of wbich 
 Ave are mainly indebted to the researches of Dr. Ballard. The one condition 
 which he finds gives an almost, if not entirely, absolute exemption from the 
 disease, is foundation of the dwellings of a locality on hard and impervious rock. 
 In such a locality, the disease may indeed spread if introduced from without, 
 but with this exception, the disease is so rare that no serious or fatal case 
 may occur, as in some parts of Devon and Cornwall, during a long series of 
 years. On the other hand, the looser and more pervious the soil, the more 
 distmctly is it found, other conditions being equal, to be conducive to a pre- 
 valence of diarrhoea among those who live in such a district, sand, gravel, and 
 marl being those soils which are most favourable to a high diarrhceal mortahty ; 
 while in the case of gravel, the smaller its particles — the nearer it approaches 
 to sand in fineness, or conversely the more its stony element predominates — 
 the greater its likeness to rock in coarseness, the more or less obvious will 
 its relation to the prevalance of diarrhoea appear. 
 
 Stagnation of air, whether induced by geographical situation, to the 
 arrangement of streets, or to the construction of houses, as when crowded 
 together on a small area, or built back to back so as to hinder or altogether 
 prevent efficient ventilation, has an important influence on the progress of 
 the malady during a period of epidemic prevalence, acting in all probability 
 through the retention in such locality of the organisms given off by the soil 
 under circumstances which have been previously mentioned. High winds, 
 on the contrary, by ventilating the soil and removing the strata of stagnant 
 air immediately above it, will check the disease while they continue, and in 
 locahties where free circulation of air is permitted and where dwelhngs are 
 well ventilated, an epidemic never gains so firm a footing ; the explanation of 
 this fact being that such conditions are in the one case favourable and in the 
 other unfavourable to the dissemination of the soil products which, as far as 
 our present knowledge leads us, must be considered the essential cause of the 
 disease. 
 
 Dr. Klein, in the course of an extensive microscopical investigation, has 
 failed to find anything in the tissues, blood, or excreta of a number of diarrhoea 
 cases to indicate that any definite microbe is concerned in the production of the 
 disease ; but Dr. Ballard, arguing from the fact that in certain groups of cases 
 in which it is apparently communicated from person to person by means of 
 the exhalations from the stools, believes that in the excretions of such cases a 
 specific micro-organism will yet be found. The conclusions at which he has 
 arrived as the result of his researches may best be given in his OAvn words : — 
 
 ' That the essential cause of diarrhoea resides ordinarily in the superficial 
 layers of the earth, where it is intimately associated with the life processes 
 of some micro-organism, not yet detected, captui'ed, or isolated. 
 
 ' That the vital manifestations of such organism are dependent, among 
 other things, perhaps principally, upon conditions of season, and on the 
 presence of dead organic matter, which is its pabulum. 
 
THE INFLUENCE OF SOIL ON HEALTH 307 
 
 'That, on occasion, such micro-organism is capable of getting abroad 
 from its primary habitat, the earth, and having become air-borne, obtains 
 opportunity for fastening on non-hving organic material, and of using such 
 organic material both as nidus and pabulum in undergoing various phases of 
 its life-history. 
 
 ' That in food, inside of, as well as outside of the human body, such 
 micro-organism finds, especially at certain seasons, nidus and pabulum con- 
 venient for its development, multiplication, or evolution. 
 
 ' That from food, as also from the contained organic matter of parti- 
 cular soils, such micro-organisms can manufacture by the chemical changes 
 wrought therein, through certain of their life-processes, a substance which is 
 a virulent chemical poison (probably ptomaine). 
 
 ' That this chemical substance is, in the human body, the material cause 
 of epidemic diarrhoea.' 
 
 In connection with the fact that rising currents of ground-air may carry 
 bacteria out of the soil into the atmosphere above, it is worthy of note, per- 
 haps, that observations have been recorded by Dr. Tomldns on bacteria in the 
 air in diarrhoeal districts in Leicester. His experiments were directed to 
 ascertain the relative number of germs present in the atmosphere in different 
 parts of the town, and particularly in those portions most affected, both be- 
 fore and during an epidemic. While diarrhoea was prevalent he found from 
 two to three times as many microbes in the air as before or after this period, 
 while in the particular region specially affected there were fourfold as many 
 as in other districts where the disease did not prevail. None of the bac- 
 teria, however, have been isolated or worked out, and the mere presence 
 of germs in quantity is no positive proof of their causative agency, so that 
 these experiments cannot be regarded as creating anything more than a pre- 
 sumption in favour of the influence of pathogenic organisms in this disease, 
 more particularly as no simultaneous bacteriological examination of the soil 
 was carried out. 
 
 Dysenteey 
 
 Many writers have considered that both dysentery and malaria are due 
 to a similar cause, for the reason that these diseases appear equally to prevail 
 in almost all situations, such as the vicinity of the swamps and sluggish 
 rivers of tropical and sub-tropical countries, which are the breeding-ground 
 of intermittent fevers. 
 
 The two diseases indeed may occur together in the same patient and at 
 the same time, and Dr. Aitken has stated that if a boat's crew be sent ashore 
 in a tropical climate, and exposed to paludal miasmata, the probabilities are 
 that of the men returning on board some will be seized with dysentery and 
 some with intermittent fever. It is also a well-established fact that where, 
 both in Great Britain and other countries, the tendency to attacks of malaria 
 has been diminished by improved drainage, and the conversion of marshes 
 into cultivated land, there also dysentery has gradually diminished to an 
 equal extent. There are, however, places in which dysentery occurs even in 
 an epidemic form, but which never under any circumstances yield ague, 
 while also all aguish districts are not necessarily dysenteric. Moreover, 
 the two diseases never graduate the one into the other, so that although it 
 is possible that the real cause of dysentery is some poison alhed to that 
 which produces malaria, the two need not be identical. 
 
 Dysentery, although still common in some parts of the world, has not 
 occurred epidemically in London since 1762, but isolated cases are still to be 
 met with which have been imported into this country from districts on the 
 
368 EYGIEXE 
 
 Mediterranean coast line, from India, Africa, Central America, and elsewhere. 
 Until within recent years, however, small outbreaks of the disease were of 
 constant occurrence in Millbank Prison. These were investigated by Dr. 
 Baly, and subsequently by Dr. Maclean, both of whom believed them to be 
 related to emanations from the soil on which the prison stands, consequent 
 on the decomposition of organic matter. It is more probable, however, that 
 the water supply rather than the ground air was at fault, since when in 1854 
 the direct supply of water fi'om the river Thames was exchanged for that 
 obtained from the artesian well in Trafalgar 8quare, dysentery suddenly 
 declined, and from that time has been unknowTi. 
 
 That soil laden with products of decomposing sewage and the like may, 
 however, be an important factor in the genesis of the disease is amply proved 
 by an interesting account given by Fagge of a series of epidemics which 
 occurred in the Cumberland and Westmorland Asylum during the years 
 1804, 18G5, and 1808. For a long time no cause for the production of the 
 disease could be traced, although it had been thought possible that it might 
 be connected with the fact that the sewage of the asylum, after being thrown 
 into a large tank, was distributed over a field about three hundred yards 
 distant. On hot and sultry evenings an offensive smell was often noticed, 
 and Dr. Clouston, the medical superintendent, then had the sewage carried 
 away to a distance tlu'ough a covered drain, with the result that no fresh 
 cases of dysentery occurred. An investigation was then made as to the exact 
 meteorological conditions which had existed during the prevalence of the 
 epidemic, and it was found that within a week before the day on which each 
 patient fell ill there had always been either hot sultry evenings, with no wind 
 in the night, or northerly winds which blew from the direction of the field 
 which was being irrigated. Male and female patients, too, were attacked at 
 different times, according as the exact direction of the wind was such as to 
 carry the sewage emanations either to one or the other of the parts of the 
 building which the two sexes severally occupied. 
 
 In the following year five cases of dysentery all occurred within a week 
 after the sewage had again been allowed to flow over the field during a calm 
 night, when the direction of the wind happened to be towards the asylum. 
 From this time the disease entirely disappeared for more than two years, but 
 on another attempt being made to get rid of the sewage by irrigation, although 
 special precautions were taken, and another field chosen, six patients con- 
 tracted dysentery within a couple of months of the commencement of the 
 experiment. All the cases occurred in that part of the asylum nearest the 
 field, and towards which the wind had been blowing continuously for eight 
 days before the outbreak occurred. The subsoil of the land surrounding the 
 asylum was a stiff' clay which was impermeable to water, and which con- 
 sequently was quite unfit for irrigation purposes, the sewage simply stagnating 
 thereon for an indefinite length of time. 
 
 Season has apparently some influence on the prevalence of dysentery, as 
 both in tropical and temperate chmates it is more apt to appear in autumn 
 than at other times of the year. The temperature of the atmosphere, or per- 
 haps of the soil, is also a factor which must be taken into consideration, as it 
 has not unfrequently been observed that the disease has occurred to a greater 
 extent in years which were exceptionally hot. 
 
 Whether any micro-organism be concerned in the production of dysentery 
 is not at present known ; but some observers maintain that it is certainly 
 contagious. The researches of Hornan and Hertwig in Norway would seem 
 to prove that the disease may be conveyed by healthy persons from infected 
 places to other spots where the disease had not before appeared, and, arguing- 
 
THE INFLUENCE OF SOIL ON HEALTH 369 
 
 from the analogy of cholera and enteric fever, it appears quite possible that 
 there may be present some organism which is capable of multiplication in 
 the body, and which reaches the outer world in the alvine evacuations. 
 
 Lead-Poisoning 
 
 This disease, or rather a form of it which has been very prevalent of late 
 years in some parts of England, must, in the light of recent researches, be 
 included in the list of those which are predisposed to by certain conditions of 
 the soil, although at first sight the relation may not appear obvious. In 
 Yorkshire particularly, lead-poisoning has always been more or less prevalent 
 owing to the trades carried on there, the file-cutters being specially liable 
 to suffer from this disease, but after eliminating all cases of lead-poisoning 
 arising from trade, a large number still remain for which the only cause 
 appears to be the taking of lead into the system through the medium of the 
 drinking water ; this supposition being confirmed by chemical examination of 
 the water which has been found to contain varying but often large quanti- 
 ties of lead. 
 
 The poisonous nature of the water in the affected areas is due to its 
 capacity for taking up lead from the pipes by means of which the water is 
 distributed. Such water is obtained from high gathering grounds on the 
 moors, and is very soft and otherwise of excellent quality, and although the 
 amount of albuminoid ammonia is usually somewhat high, in the absence of 
 chlorides and nitrates this must obviously be of vegetable origin, the peat 
 which is so plentiful at the gathering grounds occasionally also giving the 
 water a brownish tint. Where a town or district has a low-level supply also, 
 it is found that this has no such solvent action on lead ; the only reason for 
 this difference being found apparently in an acid reaction of the high-level 
 water, that obtained from the low-level gathering grounds, on the other hand, 
 being neutral or faintly alkaline. 
 
 As to the nature of the acid which is present there is considerable diver- 
 gence of opinion, since its small amount makes an accurate determination, 
 a matter of great difficulty. It appears, moreover, that the acid which is 
 found in the water obtained from the service pipes is not in some cases the 
 same as that to which the acid reaction of the water at the gathering grounds 
 is due, some chemical decomposition apparently taking place during its pas- 
 sage through the reservoirs and mains. The amount present, therefore, is 
 generally expressed in terms of sulphuric acid, which by some observers is 
 believed to be that which is always present in the water. It has been 
 suggested that such free sulphuric acid might be derived from the oxidation 
 of iron pyrites in the shale which usually underhes the beds of peat ; but even 
 though it may be present in the water of the moorlands, it by no means 
 follows that the acid will be the same when the water reaches the lead service 
 pipes, since, meeting with salts, it may have decomposed these with the 
 formation of sulphates, other acids being set free. 
 
 That this is often so can be shown by neutrahsing the water, evaporating 
 to dryness, and igniting the residue, when a carbonate is formed, thus proving 
 that the acid now present is of an organic nature. It is also non-volatile, 
 since usually none appears to be lost on concentration of the water. An 
 obvious source from which such acid might be derived, is the peat of the 
 moors, since it has been known for some time that the decomposition of peat 
 and other vegetable substances gives rise to the formation of several bodies 
 which have been described under the names of crenic, apocrenic, ulmic, 
 and humic acids. Unfortunately, however, the hterature of the subject is 
 
 VOL. I. B B 
 
370 HYGIENE 
 
 extremely scanty, and there is considerable doubt wlietber any of tliese acids 
 have ever been prepared in an absolutely pure state. In support of the 
 opinion that it is to the presence of one or more of these bodies that the 
 reaction of the water is due, it may be mentioned that where the peat is most 
 abundant the acid reaction and the amount of organic matter evidently of 
 vegetable origin are most noticeable. 
 
 As suggested by Mr. Power in his memorandum on lead-poisoning from 
 certain public water-supplies, contained in the Report of the IMedical Officer 
 to the Local Government Board for 1887, it is possible, however, that yet 
 another factor has to be considered. He believes that the action of the water 
 on lead might be due to the growth of micro-organisms in the water, basing 
 this opinion on the facts : (1) that the action on lead presents marked 
 seasonal variations, being most intense in the autumn, particularly in 
 September, October, and November ; (2) that instances are found where the 
 ability to act on lead has been newly acquired by a water-supply, so suddenly 
 and in such a manner that a great quantity of lead-poisoning is produced, 
 without any known change in the sources of water-supply, among the 
 inhabitants of a town that had previously been unacquainted with the disease; 
 and (3) finally that the introduction of some comparatively small portion of 
 a plumbo-solvent water into the total water-supply of a town has appeared 
 to confer upon the whole of such supply the power of dissolving lead from 
 the domestic service pipes of the town. 
 
 The growth of bacteria is naturally favoured by warmth, so that the 
 fermentation processes would be most active in the hottest part of the year, 
 when also a somewhat lessened rainfall and greater evaporation would tend 
 to the relative as well as absolute increase in the amount of the products 
 of the life-processes of the micro-organisms in the water, and, as has been 
 stated, it is apparently in the few months immediately following the latter 
 part of the summer that the effects of the increased action of the water on 
 lead are most prone to manifest themselves. 
 
 If this be so, it does not necessarily disprove the truth of the acid theory, 
 as it is quite possible that the organic substances which yield the acid 
 detected in the water may, at any rate in part, be the result of the presence 
 of bacteria, while some may, on the other hand, be directly derived from the 
 peaty soil. It is hardly necessary to add that the presence of so large an 
 amount of organic matter in the water, as is shown by analysis, would form 
 a most favourable pabulum for the development of micro-organisms, especially 
 when exposed to light and air in the uncovered reservoirs. In this connec- 
 tion it is worthy of note that in a number of places visited for the purpose 
 of investigating this subject, the sudden increase in the amount of lead- 
 poisoning, which first appeared in 1888, followed the dry year 1887, when in 
 Sheffield, for instance, the rainfall for the twelve months was the lowest that 
 had been recorded for fifty years. The result of this drought was that when 
 afterwards rain first fell in any quantity a considerable amount of storm- 
 water which would usually have Ijeen diverted into other channels was allowed 
 to pass mto the reservoirs, into which it would be likely to carry countless 
 numbers of bacteria and their spores, which would usually be more or less 
 perfectly removed by filtration through the soil, and these would rapidly 
 multiply in the comparatively stagnant water. 
 
 Dr. W. E. Smith has conducted a series of biological experiments on 
 behalf of the Local Government Board for the purpose of determining, if 
 possible, whether in waters which have been proved to possess considerable 
 plumbo-solvent power, microphytes are to be found which are capable of 
 working, by their life processes, acid changes in artificial culture media. So 
 
THE INFLUENCE OF SOIL ON HEALTH 371 
 
 far as these experiments have gone, although they are not yet numerous, 
 nor, according to Dr. Buchanan, at all conclusive, their results appear to be 
 affirmative, since the growth of some micro-organisms obtained from waters 
 of this class is accompanied by a distinctly acid reaction in the media in 
 which they have been grown. Further observations are, however, needed 
 before the matter can be considered to have been placed on a sufficiently 
 satisfactory basis to give definite indications as to the treatment necessary 
 for obviating a source of grave danger to a considerable section of the com- 
 munity, and Dr. Buchanan has pointed out that such researches should be 
 primarily pursued by local investigations into the environments of the various 
 water sources, and into the conditions affecting the distribution of such water, 
 observing always the conditions of time and place surrounding the waters 
 that have the power of acting on lead, and comparing them with the con- 
 ditions that environ the waters which do not show that power. Meanwhile, 
 seeing that it is apparently to the presence of free acid of some kind or other 
 that the action of these plumbo- solvent waters is due, the logical proceeding 
 is obviously to neutralise the acid, either with carbonate of sodium, with lime, 
 or with carbonate of calcium in the form of chalk or limestone. That such 
 treatment, when properly applied, is an efficient agent in preventing the 
 solvent action of water on lead has been proved in Dessau, which is, Hke 
 many of the towns of Yorkshire and Derbyshire, supplied with soft water. 
 This water, which showed an acid reaction to which its lead-dissolving power 
 appeared to be due, has become quite inoperative in this respect since a 
 method of neutralising the acid has been successfully carried out, and it 
 would appear that a similar line of treatment has been equally efficacious in 
 certain districts in this country. (See also Water, ante, p. 256). 
 
 Tetanus 
 
 It is usual to recognise a traumatic and an idiopathic form of this disease, 
 but the results of modern research all tend to support the view advanced by 
 Verneuil that tetanus is never of spontaneous origin, but always arises from 
 traumatic infection. The active agent in the causation of the disease would 
 seem to be a micro-parasite first discovered by Nieolaier in garden-earth and 
 subsequently by Eosenbach in human beings suffering from tetanus. Nieolaier, 
 experimenting on mice, guinea-pigs, and rabbits, found that when soil from 
 fields, gardens, or roads was introduced subcutaneouslyin these animals, clonic 
 spasms of the parts nearest the point of inoculation were produced, and that 
 this was followed in about twenty-four hours by general tetanus. Eosenbach 
 induced similar effects in guinea-pigs and rabbits by implanting beneath the 
 skin small pieces of tissue obtained from the neighbourhood of the wounded 
 part in a man dying of tetanus. The disease was not only produced in the 
 animals first experimented on, but by inoculation of material from the neigh- 
 bourhood of the wound from case to case it was propagated through a long 
 series of other animals. In each case the bacillus could be found in the tissues 
 near the point of inoculation, but not in the blood or any of the internal 
 organs. It is an interesting point that in cases of tetanus in the human 
 being also, the bacillus has never been demonstrated in the blood, or tissues 
 other than those at the site of the lesion ; and, moreover, inoculations with 
 tetanic blood alone have never given anything but negative results, while when 
 pus or lymph from the neighbourhood of the wound was used, positive results 
 have for the most part been obtamed. It would appear, therefore, that the 
 bacillus produces a ptomaine which, when absorbed into the blood, gives rise 
 to the characteristic symptoms of the disease. This idea is, of course, strongly 
 supported by the fact that the bacillus is only found ia the neighbourhood 
 
 BB 2 
 
372 HYGIENE 
 
 of the wound, and Brieger states that he has separated from an impure' 
 culture of the baciUus a body to which he has given the name of tetaniney 
 because it produced tetanus in animals even when injected in minute quantity, 
 by virtue of its extremely poisonous eflect on the nerve-centres. He suc- 
 ceeded, moreover, in obtaining a similar ptomaine from the amputated arm 
 of a tetanic patient, and he believes that his experiments prove that the 
 disease is due to a species of septic intoxication. 
 
 The question of the identity of traumatic and so-called spontaneous tetanus 
 is a most interesting one, and would seem to be strongly supported by ex- 
 periments carried out by Lampiasi, who, starting from a case of spontaneous 
 tetanus, obtained a virus, which after the lapse of two years was still capable 
 of inducing tetanus in a virulent form. Earth also is capable of retaining its 
 infective property unimpaired for a considerable length of time, specimens 
 which had been kept in a laboratory for between three and four years having 
 caused t}^ical tetanic attacks when inoculated into animals. This point is 
 demonstrated by Dr. Peyraud in an account of some experiments carried out 
 with soil taken from a covered-in enclosure in which wine was stored, and which 
 had not in any way been cultivated since the store was erected. With this 
 soil he obtained positive results in all his experiments, and five out of every 
 six of the animals inoculated died. 
 
 Kitasato was the first to obtain pure cultures of the bacillus of tetanus. 
 A patient having succumbed to the disease, he first inoculated pus from the 
 wound into rabbits, and having obtained positive results, he proceeded as 
 follows : — Some of the pus was inoculated into solidified blood serum and 
 agar-agar, to which had been added two per cent, of grape-sugar. These 
 cultures were kept at a temperature of 37° C. for twenty-four hours, when they 
 were found to contain a number of micro-organisms, including the bacillus of 
 tetanus, in small numbers, while on the following day the number had in- 
 creased considerably. The tubes were then exposed to a temperature ot 
 80° C. for about an hour in a water-bath in order to kill any other microbes 
 present, and the contents inoculated into mice in which characteristic tetanus 
 was induced. The spores remaining in the tubes were cultivated on plates, 
 and also in closed vessels containing hydrogen, which were kept at a tempe- 
 rature of 20° C. A week later the plates were sterile, while colonies were 
 visible in the hydrogen tubes, showing that the bacillus is ana3robic. 
 
 The cultivations have a repulsive and penetrating odour, due to gas which 
 is evolved during growth. They retain their virulence through successive 
 generations, especially when mixed with sterilised earth. 
 
 The spores of the bacillus are very tenacious of life, although active growth 
 is suspended below a temperature of 18° C. ; they are able to withstand a 
 temperature of 80° C. for from half an hour to an hour, but a moist heat of 
 100° C. destroys them in about five minutes. Ten hours' immersion in a five 
 per cent, solution of carbolic acid does not impair their virulence, but they 
 are killed in fifteen hours ; a solution of corrosive sublimate (1 in 1,000) kills 
 them in about thirty minutes, particularly if it be acidified. 
 
 The bacillus has the form of a slender rod, which, when actively growing 
 usually presents a swollen and bulged extremity, due to the presence of a large 
 terminal spore. The bacillus, which is motile, seems occasionally to multiply 
 by fission, formmg short chains. Staining reagents for the most part stain 
 the rods, but leave the spores untouched. 
 
 When inoculated into solid nutrient media, growth commences below the 
 surface, and as it increases and the bacilli gradually penetrate the mass of 
 nutrient material, a fine feathery appearance is produced which is quite 
 typical. 
 
THE INFLUENCE OF SOIL ON HEALTH 373 
 
 The telluric origin of tetanus has recently been investigated by Bassano 
 in a series of experiments carried on at Marseilles. Six specimens of earth 
 were obtained from dry localities which had not been contaminated with 
 putrefactive or organic material for a long time, and used for the inoculation 
 of twelve cobayes, but no results followed. Ten specimens of earth were 
 then taken from cultivated land, meadows, or roads, and, each being inocu- 
 lated upon two animals gave positive results. The inoculations were in each 
 case made in the right flank at the level of the hind limb. Four of the 
 animals died of septicaemia ; the other sixteen all presented similar morbid 
 phenomena as follows : — Eigidity of the limb adjacent to the seat of inocula- 
 tion was observed two days after the inoculation, the limb becoming forcibly 
 extended as this rigidity increased. By the third day the opposite limb was 
 likewise extended, and the animal assumed and preserved the dorsal decubi- 
 iiTS ; then appeared trismus, and in the majority of cases extreme dyspnoea, 
 which increased until death closed the scene, the fatal termination being 
 not unfrequently preceded by violent convulsions. This gradual implication 
 of successive parts of the body following on symptoms commencing in the 
 neighbourhood of the inoculated spot is very typical, and throws light upon 
 the action of the bacilli. As evidence that the resulting tetanus is really 
 due to inoculation of a specimen of earth or a culture of the organism at 
 the particular spot, the experience of other observers also is of considerable 
 interest. Thus Lockwood states that a few hours (usually less than twenty- 
 four) after the root of a mouse's tail has been inoculated with an appreciable 
 quantity of pure culture, the tail becomes rigid, and either bent to one side or 
 in a corkscrew fashion ; the hind legs are next seized with spasms, and some- 
 times with tremors. The spasm becomes so intense that first one and then 
 the other leg is extended, with the sole of the foot turned upwards ; then the 
 muscles of the trunk, of the fore-limbs, and of the neck and head become 
 tetanic in definite order, those nearest the point of inoculation first, and 
 afterwards those at a distance ; and in about twenty-four hours the animal 
 is dead. If the neck or fore-limbs be inoculated, instead of the root of the 
 tail, the tetanus begins in them. The period of inoculation varies, being 
 about twenty-four hours in the mouse, five days in rabbits, and from about 
 four to sixteen days in the human subject. 
 
 Verneuil has expressed the opinion, to which he still firmly adheres, that 
 "tetanus is of equine origin. He accepts as proven that the disease is a pro- 
 duct of a special micro-organism, and formulates, among others, the following 
 conclusions : ' It is probable that several domestic animals are able to infect 
 man, but satisfactory demonstration has been hitherto given only for soli- 
 peds. A wounded man can contract tetanus from the majority of neigh- 
 bouring objects which may touch his wound, but observation and experience 
 show that far the most dangerous objects are the horse with his immediate 
 surroundings, then cultivated earth and some of its products ; hence arises 
 conflict between the equinist and the tellurist. Accord would be easy if, in 
 accepting the deductions, one would subordinate the one to the other, and 
 recognise that if earth is able to induce tetanus it does so because it is soiled 
 by the tetanised horse.' He further argues that the disease is never spon- 
 taneous, but is always due to infection. His views have received great 
 support in France, so much so that we find cases recorded because no contact 
 with horses could be discovered. Other observers admit the power of culti- 
 vated soil to give rise to tetanus, but do not believe that this is due to horse- 
 manure rather than to that of any other animal, as the ox or sheep, and 
 they strongly oppose the equine origin of tetanus, not because such may not 
 be its origin, but because they consider that this has not yet been proved to 
 be the case. 
 
374 HYGIENE 
 
 The microbe of tetanus, like the vibrio of gangrenous septicaemia, may 
 be innocuous in, and pass unchanged through, the ahmentary canal of an 
 herbivorous animal, and Sarmani, in Italy, has apparently discovered that 
 such may be the case, not only in herbivorous but also in carnivorous 
 animals, the micro-organism stiU keeping its infective power. Hence 
 manure may become a potent source of tetanus dissemination. On the 
 other hand, horses are imknown in the New Hebrides, yet tetanus is very 
 common, but this, of course, is only negative e\idence. In the case of two 
 patients mentioned by Eichelot afi'ected with tetanus after ovariotomy, the 
 disease appeared shortly after manure had been spread in the hospital court, 
 thus suggesting also that air may be a vehicle for the transfer of virulent 
 germs. Terillon also reports a case in which tetanus developed fi'om a 
 wound caused by a horse-shoe soiled with manure. 
 
 There cannot now be any reasonable doubt that the tetanus-producing 
 bacillus is very widely distributed in the superficial layers of various kinds 
 of soil, on the foul surface of streets, and in the dust of dwellings. Thus 
 Bonone observed that out of seventy persons injm-ed by the faUing of a 
 church during an earthquake, seven were attacked by tetanus. Animals 
 inoculated with the dust of the church died of tetanus, although those 
 inoculated with the dust of another church did not. Again, he observed 
 that at the storming of the church in Bajaido, out of a similar number of 
 injured persons nine died of tetanus, and in three he recognised the specific 
 bacillus. He then experimented with dust taken fi-om the ruins, and found 
 that this, when inoculated into animals, produced the disease in them, the 
 bacillus bemg also found in pus taken from the inoculated part. 
 
 Although it appears probable that tetanus is usually induced by direct 
 inoculation with soil or other material containing Eosenbach's bacillus, 
 the possibility of communicating the disease from one human being to 
 another must be kept in mind, a case having been recorded where the 
 accoucheur, being in attendance on a case of trismus, transmitted the 
 disease to a woman in labour. A striking instance of apparent indirect 
 transmission from one animal to another is related by Langer, in which all 
 the horses castrated by the same ecraseur died of tetanus, while after boihng 
 the instrument in oil no others died or were afi'ected from its use. Such 
 cases, however, are rarely seen, and many observers deny the possibility of 
 direct contagion altogether. 
 
 The infiuence of predisposition cannot be denied, and doubtless plays a 
 principal part in the development of tetanus. Thus the negro race in par- 
 ticular, and those inhabiting hot chmates generally, are believed to be more 
 susceptible to the disease than dwellers in more temperate chmates, and what 
 is stiU more interestiug is the observation that the natives of hot chmates are 
 far more liable to be attacked than Europeans resident there. In the 
 American Civil War 3-1 per cent, of the cases occurred amongst the negro 
 troops, who fm-nished only 2*7 per cent, of the total number of wounds. 
 Tetanus is specially apt to occur in feeble and debilitated individuals, 
 although the robust are by no means exempt, and it is most hkely to occur,, 
 particularly in the case of wounds received on the field of battle, after sudden 
 changes of weather, such as alternations from heat to cold, especially if 
 associated with moistm-e of soil or air. Thus, in certaiu tropical climates, 
 as in some of the West India Islands and amongst the marshes of Cayenne, 
 it occurs with pecuhar frequency, the most trifling scratches or punctures 
 bemg followed by the disease. Macleod states that, after some of the Indian 
 battles when the woimded lay exposed to cold nights after very hot days, 
 tetanus was of very frequent occurrence. From these observations it seems 
 
THE INFLUENCE OF SOIL ON HEALTH d75 
 
 probable that the soil plays a double part in the aetiology of the disease ; since 
 it not only harbours the organism which is necessary for its production, 
 but may also in certain instances directly predispose to the attacks of the 
 bacillus by means of the amount of moisture it contains, or the amount of 
 heat it is capable of absorbing and of radiating. 
 
 The relation of tetanus to soil is of such interest and importance that it 
 may be well to add a brief record of some cases observed by Eiselberg which 
 he had the opportunity of investigating thoroughly. The first is that of a 
 woman in whom tetanus occurred after a compound fracture, the wound 
 having been much contaminated with dirt. Like other observers, he found 
 that neither cultures made from the blood nor inoculations of blood into 
 animals produced any effect. He found, however, the typical bacillus in pus 
 from the wound, and succeeded in transmitting the disease to animals by 
 inoculations, both of the pus itself and of cultivations obtained from it, l>ut 
 lie was unable to find bacilli in either blood or tissues. His second case 
 was a very mild one, occurring in a man who had injured his finger, the 
 wound being contaminated with dirt. Inoculation experiments, however, 
 gave no results. In the third and fourth cases he was again successful in 
 carrying on the disease through various animals — in the one, starting inocu- 
 lations after the death of the patient from small pieces of skin removed from 
 the edges of the wound, and in the other with earth from a cellar in which 
 the injury was received. His fifth and sixth cases v/ere both due to tetanus 
 following on the running of splinters of wood into the hand, and in each 
 instance the splinter, or portions of it, caused an attack of the disease in 
 rabbits, when inserted beneath the skin, the bacillus being recognised m 
 the secretion from the wounds thus caused. 
 
 In this connection it is interesting to note that the last four cases of tetanus 
 that have been under treatment in the Norfolk and Norwich Hospital were 
 all due to wounds caused by agricultural implements, such as a pitchfork and 
 a scythe. Inoculation experiments, however, were of course out of the 
 question, and unfortunately no search for the specific bacillus was made. 
 
 Anthbax 
 
 Malignant pustule or anthrax is a specific disease which is communi- 
 cable to man, directly or indirectly from the lower animals ; the herbivora 
 being specially susceptible to it. It would appear that direct contagion from 
 living animals affected with anthrax seldom or never happens, although 
 butchers, slaughterers, and veterinary surgeons occasionally become infected 
 in this way. 
 
 Under the name of woolsorters' disease, a form of anthrax has prevailed 
 at Bradford and other places for many years, which is due to the handling 
 and sorting of wool and hair obtained chiefly from Asia Minor, where anthrax 
 disease is rampant. This method of communication, however, will not now 
 be discussed, as a full account will be found in another section. 
 
 Anthrax appears to be specially prevalent in certain countries among 
 animals pastured upon damp soils containing much humus, as, for instance, 
 upon peat bogs, and near the borders of lakes and rivers that have overflowed ; 
 the hottest months of the year, particularly August and September, being 
 those during which it is most frequent. Bollinger has suggested that damp- 
 ness of soil may affect the prevalence of anthrax by affording conditions 
 favourable for the growth and multiphcation, apart from a living host, of the 
 bacillus which is the cause of the disease. The bacilh, however, only exist 
 in the soil when derived from a previous case of anthrax, either from the 
 
376 BYGIENE 
 
 excreta or discharges of a diseased animal, or from the dead bodies of those 
 which have succumbed, and which have been carelessly buried or left to decay- 
 on the surface. Pasteur indeed is of opinion that when carcases of animals 
 which have died from anthrax are buried, the development of bacilli into 
 spores can take place ui the soil, and that these spores may in turn be 
 swallowed by earth-worms and be carried to the surface and deposited in their 
 castmgs. In this way animals pastured on such soil would be hable to become 
 infected. Koch and others strongly combat this view, and seeing that spores are 
 only produced in presence of oxygen, it is quite probable that then* formation 
 would not take place, provided the animal be buried without being opened ; 
 but where this has been done for the purpose of investigating the cause of 
 death, it would appear that the amount of oxygen in the pores of the soil 
 may be sufficient to enable sporulation to come about. Schmidt Muhlheim 
 has recently brought forward some experiments which bear somewhat on 
 this point, as well as on the question of the anthrax bacillus producing spores 
 in the meat of animals afflicted with this affection at the time they were 
 slaughtered. He inoculated guinea-pigs with anthrax, and as soon as death 
 took place they were skinned, and then the hmbs were remove and placed 
 in the incubator at a temperature of 39° C. The surface of the flesh was 
 soon covered wdth a whitish film, which was found to consist exclusively of 
 anthrax bacilh, in many of which commencing spore-formation was apparent. 
 This vigorous growth did not, however, extend beneath the surface, as within 
 the tissues there did not appear to be more bacilli than were found in portions 
 of flesh which had not been placed in the incubator. 
 
 The immediate burial of the carcases of animals dying from anthrax has 
 indeed been recommended as a preventive measure against further extension 
 of the disease ; since, if the skin be intact and the interment be performed 
 at a sufficient distance beneath the surface, the spores which are more re- 
 sistant do not put in an appearance, while the bacilli themselves apparently 
 are destroyed after a varying period by putrefactive organisms, which being 
 anaerobic are capable of flourishing in absence of oxygen. But even supposing 
 that Pasteur's theory cannot be looked upon as proved, it is evident that the 
 soil may readily become infected from the discharges of moribund animals. 
 The bacilh find sufficient pabulum in decaying animal and vegetable matter 
 on the surface, and having free access of oxygen, spores are formed in them 
 in abundance, by which in turn the herbage becomes contaminated. In the 
 event of the meadows becoming flooded the spores may thus become carried 
 over the adjoining land, and may even gain access to the drinking water, 
 instances of infection of human beings having apparently been traced to such 
 a som'ce. 
 
 The Bacillus Anthracis 
 
 The specific organism of this disease is perhaps the one among those of 
 a pathogenic nature, the morphological and biological characters of which 
 have been most completely worked out. For this very reason, however, the 
 subject will be found to be presented in so detailed a manner in the bacterio- 
 logical section of this work that only the merest sketch will be attempted 
 in this place. The bacillus was first discovered by PoUender in 1849, but 
 Davaine was the first to maintain that this organism was the essential cause 
 of anthrax in its various forms. The bacilh consist of straight, slightly bent, 
 or curved rods, of comparatively large size, with square extremities ; they 
 often cohere by their ends, this being specially noticeable when they are 
 cultivated artificially. Under these circumstances they may grow into long 
 filaments in the interior of which bright granules appear. 
 
 These granules are spores, the appearance of which is of considerable 
 
THE INFLUENCE OF SOIL ON HEALTH 377 
 
 importance, seeing that they are much more resistant than the rods them- 
 selves, being able to withstand desiccation and a considerable amount of heat, 
 while under favourable circumstances they are capable of again giving rise 
 to the bacillary form. Spores only form when there is free access of air, 
 but multiplication of the bacilli also takes place by a process of fission. 
 
 The possibility of attenuating the infecting power of pathogenic organisms 
 was first established in the case of anthrax, it being found that these bacilli, 
 which thrive best in an alkaline medium, become weakened when cultivated 
 for about twenty days in a neutral nutrient fluid kept at a temperature 
 somewhat higher than that of the body. Animals inoculated with such a 
 culture pass, as Pasteur has shown, through a mild form of the disease, 
 which protects against a second attack, more complete immunity being 
 ■obtained by the subsequent inoculation of a more virulent material. The 
 protection thus afforded appears, however, to last for a certain time only, 
 when further treatment in a similar manner becomes necessary. 
 
 Klein has also shown that the virulence of the bacillus may be lowered 
 by passing it through certain animals. Thus cattle and sheep may be 
 protected for a time by inoculating them with the blood of mice which have 
 been inoculated and killed with a virulent cultivation. On the other hand, 
 .a bacillus thus attenuated may once more be made to regain its virulence 
 for sheep by first passing it through the system of a guinea-pig. 
 
 Hankin has recently announced a new method of creating immunity 
 against anthrax by means of an albumose isolated from bouillon anthrax 
 cultures, where it is formed as the result of the vital activity of the bacilh. 
 This albumose is obtained by filtering the nutrient fluid through a Chamber- 
 land filter of unglazed porcelain to remove the micro-organisms and treating 
 with absolute alcohol. He thus precipitates the albumose as a powder, which 
 is redissolved for use. 
 
 By inoculation with this chemical material rabbits and guinea-pigs have 
 loeen enabled to resist the action of virulent anthrax cultivations. More 
 powerful still is an alkaloid which Sidney Martin has obtained, also from the 
 mitrient material in which the bacilli have been grown, and it would appear 
 more than likely that Koch's ' tuberculin ' derived from cultivations of 
 "tubercle bacilli is in reality a solution of a somewhat similar substance. If 
 "this be so, it is not impossible that in the near future we may possess the 
 power of preventing the incursions of numerous diseases, to which not only 
 the lower animals but man also is liable, by means of a system of pro- 
 jective vaccinations of one and another chemical substance. 
 
 Canceb 
 
 There appears to be no doubt that the number of deaths from cancer, using 
 this term as a general designation for all malignant new growths, is gradually 
 increasing in number in this country year by year. The Eeport of the 
 Eegistrar-General for 1889 shows that there were 18,654 deaths from this 
 •cause in that year, a number which is in the proportion of 643 to each million 
 persons living, and which shows a further increase upon the ever-growing 
 rates previously recorded. Some of this increase is most certainly to be 
 attributed to increased accuracy in statement of cause of death, and to the 
 system introduced some years back of writing for further information in cases 
 where some vague cause, such as ' tumour,' has been given in the original 
 ■death-certificate ; a system which added, for instance, in the year under 
 -consideration no less than 421 deaths under the heading of cancer. Never- 
 :theless, in face of the constant and great growth of mortality under this 
 
378 HYGIENE 
 
 heading, and the expressed behef of medical practitioners specially engaged 
 in dealing with this class of diseases, that they are really becoming more and 
 more common, it seems scarcely possible to maintain the optimistic view 
 that the whole of the apparent increase can be explained as mere matter of 
 registration ; and it must be admitted, as at any rate highly probable, that a 
 real increase is taking place in the death-rate from these malignant affections. 
 
 Whether an inherited tendency, as distinct from influence of locality, 
 have anything to do with the causation of neoplastic growths or not is a 
 very difficult question ; but it needs to be pointed out that neither a con- 
 siderable proportion of cases with a family history of similar disease, nor 
 even a considerable proportion of cases with a history of such affliction 
 among the direct progenitors, is of itself sufficient evidence of inheritance.. 
 For seeing that one out of twenty- one males and one out of twelve women 
 who reach the age of thirty-five die eventually of malignant disease, it followa 
 by the law of iDrobabilities that, on an average, in one of three cases either a. 
 parent or a grandparent will have died of such an affection. Supposing such 
 parents and grandparents to have died after tliirty-five years of age, and the 
 proportion will be still higher if the circle of relatives be extended so as to 
 include not only these direct progenitors, but collateral relatives, such as 
 uncles and aunts. Seeing, however, that such a tendency if it exist would 
 not, as a rule, manifest itself till after the usual age of marriage and partu- 
 rition, it foUows that the tendency would be likely to spread wider and wider 
 among the population, there being no opportunity, as may occur in tubercular 
 phthisis, of weeding out by early death from the candidates for matrimony 
 those who are most seriously liable to this disease. 
 
 With regard to the part played by telluric and topograpliical conditions 
 in the aetiology of cancer, Haviland states as his opmion that m countries 
 having a high mortality from this disease the tributaries of rivers flow from 
 soft, marshy, and easily disintegrated rocks into sheltered valleys through 
 which the main rivers flow. During times of heavy rainfall these rains in- 
 variably flood the adjacent districts, and generally have their water coloured 
 by alluvial matter in suspension. He further cites the Thames Valley as a 
 typical cancer district in all these respects. From the statistics brought 
 forward it would appear that, as is also the case with phthisis, cancer does 
 not thrive on a high and dry soil ; but this statement must be received with 
 caution in connection with the fact that, although extensive drainage opera- 
 tions have been carried out in recent years, the death-rate from cancer does 
 not show any corresponding decrease. 
 
 Such generalisations are, however, opposed by the fact that in Norway 
 cancer occurs mostly in the mountainous districts and at considerable eleva- 
 tions, to some extent, no doubt, along the shores of the fjords, but least of 
 all, as Hirsch has shown, on the open coast. Again, in Mexico the high table- 
 land is more subject to cancer than the low plains. Obviously, therefore, 
 Haviland's conclusions, even if true for the United Kingdom, are by no means 
 universally applicable. 
 
 Calculus 
 
 In considering the connection of calculous disease with soil, it is im- 
 portant in the first place to see how the incidence of the disease is affected 
 by geographical distribution, and then to ascertain, if possible, whether any 
 common soil-condition can be found in those districts in which calculus is 
 most prevalent. 
 
 The geographical distribution of calculus, or stone in the bladder, is a 
 subject which has perhaps been better worked out than in the case of any^ 
 
THE INFLUENCE OF SOIL ON HEALTH 
 
 STQ' 
 
 other disease. In all parts of the world calculous diseases are known, but 
 in certain jDortions of the globe they are much more common than in others. 
 This is notably the case in India, hardly any part of which is exempt, although 
 the northernmost districts, particularly the North- West Provinces, are those 
 which suffer most severely in this respect. Curiously enough, it is apparently 
 only of recent years that the malady has become so prevalent in India, since 
 Scott, writing in 1816, asserted that that country had the reputation of 
 enjoying a special exemption from calculus. 
 
 In this country the evidence derived from hospital statistics, from death- 
 registration and other sources, points to a special prevalence of the disease 
 in the eastern and southern counties, while of these it is most common in 
 Norfolk. The following table compiled by Cadge, of Norwich, from the death- 
 returns for the five years 18G7-71, giving the proportion of inhabitants in 
 the several counties for each death from stone during that period, shows this 
 fact very clearly : — 
 
 Deaths from Urinary Calculus in English Counties during Five, Years 
 
 Eastern Counties . 
 
 1 in 63,475 pop. 
 
 Southern MidLands 
 
 1 in 86,367 pop 
 
 Norfolk . 
 
 „ 42,744 „ 
 
 Hunts . 
 
 ,, 59,137 „ 
 
 Suffolk . 
 
 . „ 67,081 „ 
 
 Bucks . 
 
 „ 61,335 „ 
 
 London . 
 
 „ 70,099 „ 
 
 Herts 
 
 „ 68,250 „ 
 
 Wales and Monmouth 
 
 „ 77,202 „ 
 
 Camb. . 
 
 „ 69,845 „ 
 
 Yorkshire 
 
 » 77,520 „ 
 
 Northampton . 
 
 „ 82,-525 „ 
 
 West Eiding . 
 
 „ 61,405 „ 
 
 Western Midlands. 
 
 „ 128,216 „ 
 
 N. and E. Eiding 
 
 
 Warwick 
 
 „ 65,670 „ 
 
 and York . 
 
 • ,, 71,475 „ 
 
 Shropshire 
 
 „ 66,750 „ 
 
 South-Eastern Counties 
 
 „ 83,978 „ 
 
 Worcester 
 
 . „ 73,100 „ 
 
 Kent 
 
 „ 60,585 „ 
 
 Stafford . 
 
 . „ 76,965 „ 
 
 Sussex 
 
 . „ 61,139 „ 
 
 Northern Counties 
 
 „ 191,875 „ 
 
 Berks 
 
 „ 93,470 „ 
 
 South- Western Counties 
 
 , „ 203,985 „ 
 
 Northern Midlands . 
 
 „ 85,959 „ 
 
 North- Western Countie 
 
 3 „ 209,681 „ 
 
 Leicestershire . 
 
 „ 64,115 „ 
 
 
 
 It is probable, however, that the local incidence of the disease in Norfolk 
 is even greater than v/ould appear from these statistics, since death returns 
 have only a limited value in deciding this question, it being obvious that, 
 where calculus is of frequent occurrence, operators will acquire more skill in 
 its treatment, and consequently the number of deaths from operation or from 
 non-relief of the condition will be relatively fewer. It should also be borne 
 in mind that death statistics may be open to grave fallacy from errors of 
 diagnosis made in referring death to this particular cause. 
 
 In Scotland the malady is for the most part somewhat more frequent 
 than in England, and this appears to be still more the case if mortahty 
 statistics be taken for purposes of comparison. Cadge, however, has shown 
 that this can in part be accounted for by the facts that not only are many 
 less cases admitted into hospital in Scotland than in England, but also that 
 the proportion operated on is much fewer than in this country, so that in this 
 way the mortality from calculus is increased. 
 
 Curiously enough, Ireland, on the contrary, enjoys an almost complete 
 immunity from the disease, and has done so for a lengthy period, as is shown, 
 from the earliest authentic statistics on the subject. Thus Yelloly, writing 
 in 1845, states that, although he had inquired very thoroughly into the sub- 
 ject, he found that not a single case of operation for stone had occurred fi'om 
 first to last in the hospitals supplying the three and a half millions of people 
 in Antrim, Armagh, Londonderry, Donegal, Fermanagh, Tyrone, Carlo w,. 
 Kildare, Kilkenny, Longford, Louth, Wicklow, Clare, Kerry, Galway, Eos- 
 common, Tipperary, and Mayo, and that no case had come to the knowledge 
 
380 HYGIENE 
 
 of practitioners among the poorer classes of the people in those counties. 
 For the whole of the rest of the country the result of his investigations 
 showed that the average number of operations was about six every year. 
 
 Other European countries enjoying a like immunity are Switzerland, 
 Greece, and in the more northern districts of Norway, Sweden, and Denmark, 
 Holland, on the other hand, has held the unenviable notoriety of supplying 
 the largest number of cases of calculous disease in this part of the world. 
 This fact comes out prominently in the surgical writings of the seventeenth 
 and eighteenth centuries ; and although the prevalence of the malady has 
 decreased somewhat of recent years, Janssens states that it is still relatively 
 common in Belgium. 
 
 Many of the earlier writers on this subject, from a comparison of those 
 parts of Europe and England where the disease manifests itself to the 
 largest extent, arrived at the conclusion that chmatic influences likely to 
 affect the soil, more particularly cold and damp, were of great ^etiological 
 importance in the production of the malady, Crosse, in his treatise on the 
 formation of the urinary calculus, laying special stress on the cold and wet 
 chmate of Norfolk as accounting for the gi'eat frequency of stone in that 
 comity. The results of later investigations, however, do not support this 
 theory. Thus Cadge shows that there are many parts of the North of 
 Scotland as well as of Ireland where the climatic influences are the same, 
 and yet there is none of the disease, and that in Norfolk itself stone is more 
 frequent in inland parishes than in places on the coast which are least 
 favourably situated as regards climate. In this connection it is also worthy 
 of note that in many places where stone is endemic the areas affected are 
 often very definitely bounded, so that the malady may be extremely rare in 
 closely adjoinmg districts, although the conditions as regards climate are 
 identical. 
 
 Again certain countries which have a decidedly wet and cold climate, such 
 as Norway and Sweden, are practically exempt from the disease; while, on the 
 other hand, it has been shown that Italy and Spain, for instance, and many 
 parts of Southern Asia are eminently liable to calculus. 
 
 Another hypothesis which has received a considerable amount of support 
 attributes the excessive prevalence of calculous diseases in certain districts 
 to the hardness of the water which is used for drinking purposes by the 
 inhabitants. Seeing that this will depend in turn on the nature of the soil 
 from which the water is obtained, many observers have come to the conclusion 
 that stone is more common on certain geological formations, and particularly 
 where chalk is found in abundance. This theory, which has received the 
 support of Sexton and others, who do not, however, believe that the water- 
 supply has any causative influence on the disease, would certainly appear 
 to be worthy of attention, although of late so many exceptions to the rule 
 have come to light that it cannot now be considered to be of more than 
 lunited application. 
 
 The arguments both for and against this view are so well summarised by 
 Hirsch that it may be well to quote his own words : ' When we survey the 
 distribution-area of the disease, we certainly discover an imposing array of 
 facts that can be used in support of that doctrine, such as the prevalence of 
 the disease on the calcareous and dolomite soil in the basins of the Don and 
 Volga in Kussia (to which Becketow has lately called attention), on the 
 chalk soil of the eastern counties of England, and on the Jurassic limestone 
 of the Swabian Alp in Wiirtemberg, beyond the limits of which, as on the 
 Keuper of the Necker VaUey, or on the Muschel Kalk (Triassic formation) of 
 Franconia, the Spessart, and the Khon, calculus is very unusual; further, in 
 
THE INFLUENCE OF SOIL ON HEALTH 381 
 
 some parts of Italy with a soil of limestone, such as the provinces of Brescia 
 and Cremona, on the chalk and limestone of Syria, or the Jurassic limestone 
 of Montreal, in a part of Maine with the same formation, and in Lexington, 
 Ky., which stands on more recent hmestone. But this geographical agree- 
 ment of a number of centres of calculus, very striking though it be, loses no 
 small part of its significance when we go further afield. We have to take 
 into account, on the one hand, that the disease is indigenous to an equal 
 extent on other kinds of soil, such as the basaltic trap formations in several 
 parts of the Deccan, the basaltic and volcanic tufa in Mauritius and Reunion, 
 the alluvium-covered granite of Canton, the transition rocks of North Wales, 
 the carboniferous limestone of Yorkshire, the Zechstein of Altenberg, the 
 red sandstone and variegated sandstone of the Eajestan States and other 
 parts of Hindostan, the Keuper and Muschel Kalk of the plateau of Lorraine, 
 and the clay soil of Reval and Ostend. On the other hand, we have to bear 
 in mind that large territories belonging to the more recent limestone, chalk, 
 or Jurassic formations are almost entirely exempt from the malady ; such 
 as the limestone coast-margin of Barbadoes and other West India Islands, 
 the Jurassic formation of the whole of Western Switzerland and other parts- 
 of that country, and many parts of England.' 
 
 It is difficult also to see why, if there be some such common cause pre- 
 disposing to the occurrence of stone in the bladder, the composition of the 
 concretion should not in all cases be the same. No doubt, when once a stone 
 has formed it may increase in size by the deposition of phosphatic layers, due 
 to an ammoniacal state of the urine resulting from cystitis, particularly in 
 elderly persons, who may not be able to thoroughly evacuate the bladder. 
 Apart from this, however, we find that the composition of the nucleus varies 
 in different parts of the world, even when the conditions of soil are the same. 
 Thus Vandyke Carter states that the proportion of calculi with a uric acid 
 or urate of ammonium nucleus in England is 72 per cent., while in India 
 it is only 56 ; an oxalate of calcium nucleus, on the other hand, being more 
 than twice as frequent in India as in England, a similar preponderance 
 having also been found in Wiirtemberg and Moscow. It is possible that 
 oxalate may in some eases develop from uratic calcuh, but it is impossible 
 to account for the frequency of their occurrence in certain localities m this 
 way. Many suggestions have been brought forward, ascribing the differ- 
 ences to peculiarity of race, of constitution of diet, with exposure to prevalent 
 easterly winds, and the like, but probably but little weight can be attached to 
 any of these supposed factors, the exact setiology of calculous disease having 
 yet to be worked out. 
 
 ElCKETS 
 
 Many are the attempts that have been made to define a cause for this 
 disease. Among those which have from time to time been suggested are 
 prolonged suckling or, on the other hand, prematiu'e weaning ; the effect of 
 indigestible and insufficient food or of a deficiency in it of Hme and of phos- 
 phoric acid. Experimental evidence has been invoked in support of these 
 various theories, but the results have not been such as to give definite 
 support to any one of them. All authorities are agreed that the morbid 
 process is fundamentally a disorder of nutrition, a cause for which must 
 probably be sought for either in an hereditary taint or in the manner of 
 bringing up, defective or improper food, if it bear any import, acting, however, 
 only indirectly by producing general weakness. 
 
 A noteworthy point to which attention has not perhaps been sufficiently 
 directed comes out when we examine into the geographical distribution 
 
882 HYGIENE 
 
 of the disease. Tliis is that, while in temperate regions it is moderately 
 common, tropical and subtropical countries are almost free from it, particu- 
 larly in its severer forms. There is, in fact, abundant evidence that, both in 
 amount and severity of type, the disease stands in a definite relation to 
 climate, and that, as Hirsch has stated, countries with a cold and wet climate, 
 subject to frequent changes in weather, such as Holland, many parts of 
 England, the North German plain, the mountainous regions of Central and 
 Southern Germany, and the plains and mountainous districts of Northern 
 Italy, if they are not the exclusive seat of rickets, are at all events its head- 
 quarters. It wQuld appear, moreover, that of the districts mentioned the 
 disease is more prevalent wherever the character of the climate is specially 
 dependent on the nature of the soil ; as, for instance, in the neighbourhood of 
 marshy plains or in valleys which are deep and damp and liable to frequent 
 floods. 
 
 Oppenheim, indeed, arguing from this preference exhibited by the disease 
 for wet and marshy districts, and fi-om the fact that enlargement of the spleen 
 is not unfrequently found in rickety children, has been led to the conclusion 
 that the disease is in some way related to a malarial taint. There is, however, 
 little or nothing to be found in support of this \dew, and, indeed, it would 
 appear that in some instances at any rate rickets is least common just in 
 those very districts where malaria is worst. 
 
 On the other hand, rickets is of rare occurrence at elevated sites, particu- 
 larly where the soil is also dry, even though at the same time the hygienic 
 conditions among which the population live may be the reverse of favourable. 
 From a consideration of these observations it would appear, then, that a line 
 of treatment which might be expected to be attended with beneficial results 
 would consist in the removal of children subject to this disease to a warmer 
 and drier climate for a time. Unfortunately in the majority of cases, such a 
 complete change is usually impossible, and recourse must therefore be had 
 to care in feedmg, combined with warm clothing, exercise in the open air, 
 and medical treatment of a more or less empirical kind. 
 
 GOITEE AND CbETINISM 
 
 Although these diseases, and more particularly goitre, occur in widely 
 different portions of the globe, it is a remarkable fact that in each locality 
 when they are endemic the incidence is mainly on a small circumscribed tract 
 of country, the surrounding districts being often completely free. There is, 
 then, an mtimate relation of these diseases to locality, and probably there- 
 fore to the natm-e of the soil or the soil contents, Klebs having shown that 
 atmospheric influences, such as the amount of sunlight, air, and so on, play 
 but a subordinate part in the matter, as if otherwise these affections would 
 not be so limited to particular spots as is invariably the case. 
 
 It is, moreover, a well-recognised fact that healthy persons coming into 
 goitrous districts from places where the disease is unknown not unfrequently 
 contract the malady, sometimes after a very short stay only ; while, on the 
 other hand, removal from goitrous centres has been found to have an influ- 
 ence for good, either in preventing the occurrence or in arresting the further 
 development of the disease. A further not unimportant point is found in the 
 occurrence of goitre among domestic animals, such as horses, mules, goats, 
 sheep, pigs, cats, and dogs ; a fact Avhich was Imown to Pliny, and which has 
 been amply substantiated by niimerous observers since his day. 
 
 What are the precise conditions of soil common to all the various centres 
 of goitre and cretinism, and which are concerned in the production of these 
 
THE INFLUENCE OF SOIL ON HEALTH 383 
 
 nearly related diseases, is, however, an exceedingly difficult question. Certain 
 it is, at any rate, that the degree of elevation, or the configuration of the 
 .ground, has no influence as an setiological factor, seeing that, although per- 
 haps mountainous districts are more frequently affected than lower lying 
 tracts of country, and that in coast regions goitre is apparently unknown, 
 nothing further can be definitely stated in this respect which can be shown 
 to be of universal application with regard to the various situations in which 
 goitre is known to occur. The same remarks will apply to the theory first 
 propounded by Saussure, and which has received a certain amount of support, 
 namely, that the spots of greatest intensity are to be found in deep dark valleys, 
 where soil and air alike are damp, since innumerable instances could be ad- 
 duced of wide tracts of level country which suffer to quite a similar extent, 
 even where the soil is of the driest. A wet or marshy soil will be likely 
 to be prejudicial to the health of those living upon it, and, therefore, it is 
 likely that a change for the better in this respect may become apparent after 
 the effectual drying of the soil by subsoil drainage and the like. In this 
 manner, no doubt, may be explained the decrease in the amount of goitrous 
 disease which has occurred of late in certain situations which formerly were 
 more subject to it than at present, the improved hygienic conditions by im- 
 proving the health of the population having rendered them less liable to 
 the incursions of the disease. 
 
 We are thus brought back to the conclusion that there must be some 
 connection between the geological and mineralogical character of the soil 
 and the endemic occurrence of these affections, but the discrepancies of opinion 
 between the various observers who have investigated the subject afford but 
 little ground for the foundation of anything like a dogmatic assertion on the 
 subject. As a matter of fact, it would appear that sufficient care has not 
 been bestowed on the determination of the true geological conditions of the 
 particular localities under consideration, especially as it would be necessary 
 to investigate not only the characters of the upper layer of the soil, but of 
 the subjacent strata also, since not only may they be very different from the 
 surface soil above, but they may influence, to a much greater extent, the 
 composition both of the air and water of the district. 
 
 A view that has much to be said in its favour, and which, down to the 
 present day, has been accepted by many observers, is that which supposes 
 that the use of water containing certain mineral constituents in considerable 
 quantity plays the chief part in the genesis of goitre. Thus in many parts 
 of the world, so-called ' goitre springs ' are to be found which have the popu- 
 lar reputation of causing the appearance of the disease in those who drink 
 of them ; and so firmly rooted is the belief that there are numerous records 
 of malingering, especially soldiers desirous of escaping active service, having 
 taken the water with the hope of inducing an attack. 
 
 As to the exact nature of the ingredients of the water which would appear 
 to possess this power for ill, there is great diversity of opinion, but seeing 
 that the nature of the water must in time depend on that of the soil from 
 which it springs, or over which it flows, it might be supposed that careful 
 examination of the constituents of the soil in affected areas might enable us 
 to decide the point ; unfortunately up to the present no such successful 
 result has been obtained. Many suspected goitre springs contain a large 
 amount of carbonate of calcium or gypsum dissolved in the water, and thus 
 the idea arose that endemic centres of goitre were to be sought for in places 
 where there was a limestone soil. On attempting to put this theory to the 
 proof accurate examination of the soil has undoubtedly furnished a consider- 
 able amount of corroborative evidence on the point. Thus McClelland, who 
 
884 
 
 HYGIENE 
 
 instituted a most thorough iuqiiiry into the subject in the provinces of Ku- 
 maon, on the slope of the Himalaya, records the result as follows : — 
 
 ' In ninety- one villages situated on granite and gneiss, hornblende slate 
 and mica slate, clay slate, green sandstone, granitine, and silicious sandstone, 
 having an aggregate population of 5,383, there were twenty-nine goitrous 
 jjersons and no cretins ; whereas in thirty-five villages, on Alpine limestone 
 (i.e. Jurassic limestone and Zechstein), having an aggregate population of 
 1,1 GO— 390 cases of goitre were found and thirty-four of cretinism.' These 
 statistics have received support from Billiet and others, who asserted that in 
 numerous instances in which adjoining districts were found to show a strik- 
 ing difference in the extent to which goitre was prevalent the state of the 
 soil was obviously the determining factor in the one direction or the other, 
 seeing that apparently an affected district might, in all other respects, be under 
 absolutely similar conditions to an adjacent spot where the disease was un- 
 known. 
 
 A more extended series of observations soon showed, however, that this 
 theory required modification, and the balance of opinion veered round to the 
 hypothesis, originally put forward by Zambroin in 1825, and later brought into 
 notice independently by Grange, that the question did not depend on the 
 presence of limestone itself so much as on the amount of magnesium salts 
 combined with it, goitre being found to the maximum extent in persons living 
 on a soil of magnesian limestone or dolomite. ' However various the ele- 
 vation, the configuration, and the formations ' of the regions investigated 
 ' might be, an unvarying factor in them all was the presence of magnesia in 
 the rock, whether it occurred in the form of magnesia containing silicates (as 
 particularly in gneiss and granite and hornblende rocks) or in the form of 
 dolomite ; and it was the absence, or the somewhat scanty or infrequent 
 occurrence, of magnesia in the younger Jurassic rocks, in the chalk, and on 
 the Tertiary formations that explained the immunity of localities in the soil 
 of which these predominated.' 
 
 Striking as is the manner in which this theory, so ably developed by 
 Grange, fits in with the results of observation in various parts of the world 
 most widely separated from one another, such as Central Europe, Oudh, and 
 Brazil, it is evident that it cannot be considered as by any means of 
 universal application. Thus Thomson and others have called attention to 
 the fact that, although in New Zealand large masses of magnesian limestone 
 lie exposed in the Northern Island, where live by far the greater part of the 
 native population, goitre is a disease entirely unknown among them. 
 
 Yet another theory, apparently, however, more untenable than the older 
 ones it challenges, is due to Saint Lager, who, as the result of a most com- 
 prehensive study of the geological characters of the soil in all parts of the 
 world, as far as they could be ascertained, came to the conclusion that the 
 results of former observers as to the importance of the presence of magnesia 
 was capable of explanation in another manner. According to his view, goitre 
 or cretinism is prevalent in those districts only where there is an amount 
 of metal-yielding rock to be found, the undoubted connection traced by 
 others between the extent of the disease and the amount of magnesia in the 
 soil being due, in his opinion, to the fact that limestone rock frequently con- 
 tains sulphide of iron. Iron, however, is not the only metal producing this 
 result, as the presence of copper pyrites might, he believed, produce a similar 
 effect. 
 
 From what has already been stated it will be seen how various are the 
 different theories that have been brought forward to account for the special 
 prevalence of goitrous diseases in certain localities, but at the same time it 
 
THE INFLUENCE OF SOIL ON HEALTH 385 
 
 is noteworthy that without exception they all agree in referring such ende- 
 micity to conditions of the soil, although at this point agreement ceases, so 
 that the problem must be looked upon as one which still awaits solution. 
 It appears certain, however, that whether or not the presence of magnesium 
 salts in the soil in any way predisposes to diseases of this kind, it is 
 extremely unlikely that the result is brought about through the medium of 
 drinking water which has been rendered hard by an abnormal quantity of 
 such salts. 
 
 ^ EXAMINATION OF SOIL 
 Physical and Chemical Examination of Soil 
 
 From one point of view the soil may be considered as a mass of particles 
 of matter having certain physical properties which will depend on the 
 relative size of the particles of which it is composed, on the density with 
 which they are packed together, on their power of absorbing and retaining 
 water, and on the friability of the mass. 
 
 Surface or subsoil can be mechanically analysed either by removing a 
 block of a certain size, for instance a cube of about six inches, or by taking 
 a known weight (100 grammes), which after being dried and broken up by 
 the hands is passed through a series of sieves. In this way the stones may 
 be separated according to their various sizes by the sieves of larger and 
 smaller mesh until fine particles only are left. These again may be 
 separated still further by mixing thoroughly with water, and then when the 
 coarser particles have subsided, pouring off the supernatant fluid containing 
 suspended matter, which consists, for the most part, of silicate of aluminium. 
 This part of the process is more accurately carried out by the use of Noebel's 
 apparatus, which subdivides the finer matter into four or more grades. 
 
 Such a mechanical analysis is, however, of comparatively little importance, 
 except in so much as it makes a distinction between the silica which exists 
 as sand and that which is present as clay ; a distinction which is not shown 
 in an ordinary chemical analysis, in which both kinds of silica would be 
 classed together. Should the soil consist almost entirely of clay, it will dry 
 into a hard mass, which it may be extremely difficult to break up with the 
 hands alone ; if, however, it constitutes what is called loam, though still 
 drying into lumps, it will break up more readily than true clay owing to an 
 admixture of sand or lime. If this latter substance be present in considerable 
 amount, the term calcareous will be applied to the soil. The presence of 
 lime in the soil is easily detected by adding a few drops of hydrochloric acid, 
 which by disengaging carbonic acid gas from the carbonate, the form in 
 which lime usually occurs, causes effervescence. The extent and duration 
 of this give an approximate idea as to the amount of lime present. 
 
 By such a simple examination of soil a considerable amount of information 
 may be obtained which is of importance from a hygienic standpoint, but 
 when possible this should be supplemented by a more extended chemical 
 examination. The various constituents of the soil may obviously be some- 
 what numerous, but of these a certain number are extremely rare, and for 
 most purposes it suffices if a determination of the following substances be 
 made— viz. silica, alumina, Mme, magnesia, chlorine, sulphuric and nitric 
 acids, carbon and nitrogen. Of these, the two latter exist for the most part 
 in combination in the organic constituents, although, as has been mentioned 
 carbonic acid is also present m the free state in the interstices of the soil. 
 
 Certain of these constituents or compounds of them are not soluble in 
 
 VOL. 1. CO 
 
38G HYGIENE 
 
 water, although they are capable of being taken up by plants. Such is the 
 case, to a considerable extent, with phosphoric acid in the soil. The fact has 
 been demonstrated that when the roots of plants come in contact with a stone 
 slight indentations Avill be produced which have evidently been eaten away 
 during the growth of the roots. This is accomplished by means of the 
 extremely thin membranes of the root-hair being permeated by an acid juice 
 which coming in contact with the surfaces of the particles of soil renders 
 soluble the molecules of nutrient materials adhering there ; it thus becomes 
 possible for these substances to penetrate into the root-hairs according to the 
 laws of diffusion, and thence to pass over into the stream of sap to be carried 
 finally to the organs of assimilation. Sachs has shown experhnentally that 
 roots which become closely applied to the pohshed surfaces of marble plates 
 corrode them so that after a time a corrosion figure of the roots is obtained 
 on the marble surface. Consequently it is usual in agricultural chemistry 
 to estimate the composition of such portions of the soil as are soluble in 
 water and in hydrochloric acid respectively, the former portion being regarded 
 as that which is capable of immediate utilisation by plants, while the latter 
 insoluble portion is looked upon as a reserve fund which may be utilised in 
 the future. 
 
 In order to estimate the amount of organic matter in the soil a known 
 quantity is weighed after careful drying, heated to redness, and then 
 reweighed, the loss of weight representing the organic matter which was 
 present. A possible fallacy must, however, be borne in mind in conductmg 
 this process, particularly when a clay soil is being examined, seeing that in 
 such a case a considerable amount of the loss of weight which occurs on 
 heating will be due, not to organic matter, but to water of combination, which 
 is not driven off unless the temperature be raised above that of boiling water. 
 
 Owing to this fact the amount of organic matter present in clay soils has 
 been supposed to be as much as from 10 to 12 per cent., which is obviously 
 erroneous. 
 
 The portion which remains after the organic constituents have been 
 dissipated by the effect of heat consists of the inorganic or mineral consti- 
 tuents. 
 
 The substances soluble in water consist for the most part of chlorides, 
 sulphates, and nitrates, while the greater part of the magnesia, lime, alumina, 
 and iron are insoluble. It is important to determine the extent to which the 
 constituents of a given soil are thus soluble, so as to obtain an indication as to 
 whether drinking water obtained from such a soil is liable to be injuriously 
 affected. For this purpose 10 grammes are to be thoroughly shaken with 
 distilled water. Filter ; evaporate the filtrate, weigh, and incinerate. The 
 loss of weight after incineration will indicate organic matter, together with 
 varying amounts of water of combination and of ammonia ; Way having 
 shown that the absorbent property of clay particularly enables a soil to retain 
 such an amount of ammonia in the soil as to exert a very important purify- 
 ing influence upon water impregnated with organic and other substances, 
 which find their way slowly through the soil. Dissolve the residue again 
 in water and examine for chlorine, sulphuric acid, lime, alumina, iron, and 
 nitric acid. (A description of the necessary methods will be found in the 
 section on Wateb.) 
 
 To the portion insoluble in water add pure hydrochloric acid after pre- 
 vious evaporation. Or, more accurately, (1) take 40 grammes of a fresh 
 portion of the soil and to it add 30 c.c. of hydrochloric acid and heat, noting 
 whether effervescence takes place. Add 100 c.c. of distilled water and 
 digest for about twelve hours. Filter ; dry and weigh the residue. 
 
THE INFLUENCE OF SOIL ON HEALTH 387 
 
 (2) To the acid solution add ammonia, which will precipitate oxide of iron 
 and alumina. Filter ; dry and weigh the precipitate. 
 
 (3) To the filtrate add ammonium oxalate. Filter ; dry ; wash and burn 
 the calcium oxalate and weigh the calcium carbonate produced. 
 
 (4) To the filtrate from (3) add sodium phosphate. Collect the precipitate ; 
 dry and weigh. Every 100 parts represents seventy-nine parts of magnesium 
 carbonate. 
 
 (5) The residue remaining after treatment with hydrochloric acid consists 
 of clay, quartz, and silicates of aluminium, iron calcium, and magnesium. 
 Fuse with three times its weight of sodium carbonate and then heat with 
 dilute hydrochloric acid. Iron, lime, alumina, and magnesia will enter into 
 solution, silica remaining undissolved. Filter ; dry and weigh the insoluble 
 residue. 
 
 (6) Evaporate the filtrate from (5) to dryness. Moisten the residue with 
 a concentrated solution of ammonium nitrate and heat on the water-bath 
 until the evolution of ammonia ceases. Add hot water, filter, wash the 
 alumina and ferric oxide ; dry, ignite and weigh. ^ The mixed oxides should 
 now be heated in a porcelain boat for about half an hour, while a stream of 
 dry hydrogen or coal gas is passed over them. To the mixture of alumina 
 and reduced iron add a 2^ per cent, solution of nitric acid in distilled water ; 
 warm, filter, precipitate the ferric oxide by ammonia, wash, dry and weigh it. 
 By deducting the weight of ferric oxide from that of the mixed oxides the 
 quantity of alumina is obtained. 
 
 The iron may also be estimated by heating the mixture of alumina and 
 ferric oxide with dilute sulphuric acid, filtering, reducing with a small piece 
 of zinc, and titrating with a standard solution of potassium permanganate. 
 
 This method of estimating Fe depends on the fact that KMn04, added 
 to a solution of a ferrous salt, oxidises it to the ferric state. 
 
 The reaction is : 
 
 10FeS04-f 2KMn04 + 8H2SO4 = 5Fe2(S04)3 4- K2SO4 -f 2MnS04 -f 8H2O 
 
 The ferrous solution, prepared as above directed, is made up to bulk 
 with cold distilled water in a 250 c.c. flask, and 50 c.c. of this solution are 
 transferred to a beaker containing 200 c.c. of air-free water standing on 
 a sheet of white paper. Now run in the standard permanganate from a 
 Mohr's burette, provided with a glass stopper, little by little, and with constant 
 stirring : as the KMn04 falls into the solution of ferrous salt a pink blush 
 is formed, but disappears on stirring as long as there is any ferrous salt un- 
 oxidised to ferric. As soon as all is converted into ferric, the pink coloura- 
 tion is permanent, and this is the end of the reaction. Eead off the number 
 of c.c. needed to effect this, and repeat with two more successive quantities of 
 50 c.c. of the ferrous solution, and take the mean of the three results as a 
 basis for calculation. The permanganate solution requires standardising 
 from time to time ; the method of doing this and the preparation and 
 standardisation of the permanganate solution in the first instance are well 
 given in Thorpe's ' Quantitative Analysis,' p. 148. 
 
 Calculation : 
 
 Let X = number of c.c. KMn04 used, 
 
 y = weight of Fe in grammes oxidised by 1 c.c. KMn04 ; 
 
 • • -^y ^ >) J) »> V ^ >j 
 
 i.e. xy = „ ,, in grammes in 50 c.c. solution ; 
 
 /. 5xy= Fe in 250 c.c. or in mixture of Fe and Al from (6). 
 
 1 For the total aluminium and iron the results of (2) should be added to the residue 
 thus obtained. 
 
 c c 2 
 
)88 
 
 HYGIENE 
 
 Appended are some complete analyses of surface soils which give a fair 
 idea of the mamieriu which they ditier from one another iu composition : — 
 
 Complete Analyses of Soils (Lloyd) 
 
 
 
 
 
 
 
 No.V. 18 
 
 — 
 
 No. I. 
 
 No.IL 
 
 No. in. 
 
 No. IV. 
 
 No. V. 
 
 to 27 in. 
 deep 
 
 ♦Organic matter and water 
 
 
 
 
 
 1 
 
 
 of combination . 
 
 5^033 
 
 6^844 
 
 4^200 
 
 8^858 
 
 3-450 
 
 1-550 
 
 Oxide of iron 
 
 5-200 
 
 5-312 
 
 3-659 
 
 6-350 
 
 4-001 
 
 3-201 
 
 Alumina .... 
 
 3-400 
 
 4-560 
 
 4-100 
 
 8-430 
 
 •649 
 
 •449 
 
 Lime ..... 
 
 1-360 
 
 3-312 
 
 •670 
 
 •484 
 
 •431 
 
 •151 
 
 Magnesia .... 
 
 •400 
 
 •432 
 
 •266 
 
 •466 
 
 •225 
 
 -201 
 
 Potassium oxide . 
 
 •3G5 
 
 •468 
 
 •320 
 
 •333 
 
 •282 
 
 •253 
 
 Sodium oxide 
 
 •r2i 
 
 •179 
 
 •031 
 
 •092 
 
 •069 
 
 •023 
 
 Phosphoric acid . 
 
 •141 
 
 •204 
 
 •141 
 
 •217 
 
 •217 
 
 •141 
 
 Carbonic acid 
 
 •875 
 
 1-640 
 
 •380 
 
 — 
 
 — 
 
 — 
 
 Sulphuric acid 
 
 •060 
 
 •109 
 
 •061 
 
 •137 
 
 •130 
 
 •089 
 
 Nitric acid . . . • 
 
 •001 
 
 •001 
 
 •001 
 
 •002 
 
 •008 
 
 •002 
 
 Chlorine .... 
 
 •005 
 
 •Oil 
 
 -002 
 
 •005 
 
 •007 
 
 -004 
 
 flnsoluble silicates and sand 
 
 88^066 
 
 77-401 
 
 86-232 
 
 79-733 
 
 90^675 
 
 93-925 
 
 
 100-027 
 
 99-973 
 
 100-063 
 
 100-107 
 
 100^144 
 
 99-989 
 
 f Consisting of oxide of iron . 
 
 1-827 
 
 1-625 
 
 •763 
 
 1-594 
 
 I 1-995 
 
 2-723 
 
 Alumina .... 
 
 6-188 
 
 4-489 
 
 6-607 
 
 1^897 
 
 
 Lime .... 
 
 •511 
 
 •774 
 
 •638 
 
 •558 
 
 •553 
 
 •732 
 
 Magnesia .... 
 
 •388 
 
 •332 
 
 •167 
 
 •223 
 
 •126 
 
 •181 
 
 Potash .... 
 
 •424 
 
 •578 
 
 •182 
 
 •358 
 
 •399 
 
 •197 
 
 Soda 
 
 •920 
 
 •534 
 
 •304 
 
 1-012 
 
 1^242 
 
 •779 
 
 Silica . . . . 
 
 72^848 
 
 69-273 
 
 77-626 
 
 74-091 
 
 86-360 
 
 89-363 
 
 
 83^106 
 
 77-545 
 
 86-287 
 
 79-738 
 
 90-675 
 
 93-925 
 
 ^Containing nitrogen 
 
 •170 
 
 •107 
 
 •141 
 
 •254 
 
 •101 
 
 •050 
 
 In the first three specimens of soil which were analysed by Dr. Voelcker 
 there was a considerable amount of clay, they being what are termed ' stiff ' 
 soils, while No. IV. is a loamy soil from Bedfordshire, and No. V. a light 
 sandy or gravelly soil. The sixth table shows an analysis of the subsoil 
 lying beneath No. V., and it is obvious that it contains far less soluble con- 
 stituents than the surface layer above. 
 
 Bacteeiological Examination of Soil 
 
 The number of bacteria which may be found in mould or surface soil is 
 usually very large, although pathogenic organisms are comparatively rare, 
 except perhaps in the filth-laden soil of crowded and insanitary districts. 
 Certain forms, indeed, are distinctly beneficial, since by their hfe processes 
 oxidation (nitrification) of nitrogenous organic matters in the soil is brought 
 about, while other forms, as agents of putrefaction and fermentation, play a 
 very important part in the economy of nature. 
 
 It will be obvious, therefore, that the mere presence of even considerable ' 
 numbers of micro-organisms in a sample of earth does not of necessity show 
 that there is danger to health in building on or even in obtaining water from 
 the locality from which it is taken, and therefore the mere enumeration of 
 the number of colonies which can be grown on a nutrient medium from a 
 given weight of earth is a very fallacious test. 
 
 In addition, the various colonies must be isolated and sown on media of 
 various kinds, and methods of staining, and even of experimental inoculation, 
 
THE INFLUENCE OF SOIL ON HEALTH 389 
 
 would require to be carried out before it can be definitely asserted that any- 
 thing of a pathogenic nature is present or not. It is, of course, impossible 
 that such an examination can in every case be carried out in its entirety, and 
 therefore we are thrown back on the use of the ordinary microzyme test, the 
 only use of which is in enabling us to judge of the approximate number of 
 micro-organisms present, and not in forming an opinion as to whether the 
 soil is of such a nature as would be likely to harbour organisms of a dangerous 
 nature. 
 
 For the purpose of obtaining a cultivation of the micro-organisms in soil 
 there are various modes of procedure. Either the ground air aspirated from 
 diiierent depths (as in the method used by Lewis and Cunningham for the 
 estimation of the carbonic acid) may be drawn over the surface of nutrient 
 gelatine, or samples of the soil itself may be examined. This, which is the 
 simpler method, is carried out as follows : — 
 
 A sample of earth is first dried, then finely powdered and shaken up in a 
 test tube of sterilised water, a drop of this being afterwards transferred to 
 another tube of peptone-broth or gelatine. Again a small quantity of the 
 earth may be sprinkled directly over the surface of nutrient gelatine prepared 
 for a plate cultivation. The best method of all, however, probably consists 
 in taking a carefully weighed amount of dried and pulverised earth and 
 adding it to a test tube of gelatine, which has been previously rendered fluid 
 by heat. By shaking it is distributed as evenly as possible through the 
 medium, which is then poured out over the surface of a carefully levelled 
 glass plate, on which it gradually sets into a solid film. If the plate has 
 been previously divided up into squares by carefully ruled lines cut on the 
 luider surface of the glass, it is very easy to count the number of colonies 
 which develop in a given area, and so by counting the squares to calculate 
 the number of bacteria that were originally present in the given sample of earth. 
 These colonies become noticeable after a few days' growth, when the various 
 species, owing to the difference in their mode of growth, will form clusters 
 varying in size, aspect, and arrangement. As Klein has shown, however, 
 it must be borne in mind that the number of colonies is no absolute index of 
 the number of bacteria in the soil for the following reasons : (a) not every 
 colony that makes its appearance on the plate cultivation — even granted that 
 it is due to the growth of a single species, which is not invariably the case — 
 owes its origin to one single individual, since, for instance, micrococci, 
 bacteria, and bacilli may occur in the original sample as zooglea and chains, 
 and these cannot by any amount of shaking be broken up into single 
 elements ; {h) not all bacteria introduced into the gelatine come up as colonies, 
 since not all of them are capable of growing in the gelatine, and not ah. of 
 them can thrive at the temperature at which the gelatine remains solid ; (c) 
 the liquefaction of the gelatine by some of the colonies and not by others does 
 not necessarily indicate different species, since this depends sometimes on 
 the nature of the nutrient gelatine, and to the fact whether the growth takes 
 place in the depth or on the surface ; [d) accidental contamination with 
 organisms of the air during the preparation of the plate cultivation cannot 
 be prevented, and if the air happens to contain a good many organisms, 
 as would be likely to be the case in an ordinary laboratory, for instance, 
 the total number of colonies appearing in the plate cultivation may 
 exceed the number of bacteria present in the sample of earth which was 
 being tested. 
 
 There are certain pathogenic organisms which have so typical a mode of 
 growth, as is the case with the anthrax bacillus, which has been proved by 
 Pasteur to be capable of existing in the soil, that their presence or absence 
 
390 HYGIENE 
 
 may be detected by simple examination of the cultivation, but, as stated 
 above, this -svill usually not be the case. 
 
 In a similar manner to that already described, the dust which settles from 
 the air in houses and hospitals or other pubhc buildings may be distributed 
 over the surface or in the substance of nutrient gelatine, and thus the micro- 
 organisms which develop may be studied both as regards their morphological 
 and biological characteristics. 
 
FOOD 
 
 BY 
 
 SIDNEY MARTIN, M.D., F.R.C.P. 
 
 ASSISTANT PHYSICIAN TO UNIVERSITY COLLEGE HOSPITAL 
 
FOOD 
 
 By food we mean the substances taken into the body which are utilised in 
 maintaining the functional activity of the organism. By means of food 
 during adolescence, growth is maintained, and in adult life the body-weight 
 remains at a healthy level, or increases in particular conditions, the tem- 
 perature is maintained, and muscular effort is made possible. The importance 
 of the scientific study of food and of dietetics from a hygienic standpoint 
 cannot therefore be overestimated. The definition just given would neces- 
 sarily include under the heading Food the oxygen taken into the body by 
 means of the lungs ; and, strictly speaking, oxygen is a food, and one of 
 the most important. The taking in of oxygen is, however, unlike that of 
 food, in the main an involuntary act ; so that the term 'food' is limited 
 to substances taken by the mouth into the digestive tract, where, for the 
 most part, they undergo changes preparatory to entering the tissues of the 
 organism — preparatory to assimilation, as the process is termed. 
 
 The Proximate Pbinciples op Food, ok Foodstuffs 
 
 are the substances which constitute food. They may be classified as 
 follows : — 
 
 [1. Nitrogenous, as proteids or albuminoids. 
 I. Organic \ i{a) Fats. 
 
 (2. Non-nitrogenous \{h) Carbohydrates. 
 [(c) Vegetable acids. 
 II. Inorganic (1- Mineral salts. 
 
 .2. Water. 
 III. Food- accessories, such as tea, coffee, alcohol, creatin, &e. 
 
 The first two classes of foodstuffs are essential to life ; but in the food 
 of man there is a third class of what may be called ' food-accessories,' 
 which hold an important position in dietetics. They are flavouring 
 agents, stimulants, &c., and are well expressed by their German name, 
 * Genussmittel.' 
 
 Nitrogenous Foodstuffs 
 
 The greater part of the solid constituents of the tissues of the body (with 
 the exception of bone) consists of abuminous or proteid substances ; the 
 liquids of the body also contain them in solution, not only the blood and the 
 lymph, but also the interstitial liquid of the tissues, which is really a form of 
 lymph. A certain amount of nitrogen in the form of urea (30 to iO 
 grammes or 500 grains daily), and of uric acid (0-5 gramme or 7 to 10 
 grains daily), with a few other nitrogenous bodies in small amount, is daily 
 excreted in the urine. These nitrogenous bodies are formed fi-om the 
 destruction (oxidation) of the proteids of the body ; the nitrogen they contain 
 is a loss to the body, and to repair this loss a daily intake of nitrogenous 
 food is necessary. By this means the nitrogen-equilibrium of the body is 
 
394 HYGIENE 
 
 maintained — that is, the relation between the intake and output of nitrogen. 
 The equihbrium is, however, not perfect, since the sum of the nitrogen 
 passed in the urine and fa?ces is less than that taken into the system. The 
 only form of nitrogen which the body can assimilate is that of proteid or 
 albuminous substances. The plant builds up its proteids from the nitrates 
 and ammonia of the soil, but the animal cannot do this : it utilises the 
 proteids originally synthetised by the plant. 
 
 Proteids are composed of carbon, hydrogen, nitrogen, and oxygen ; they 
 all contain sulphur, and some contain phosphorus. Their chemical con- 
 stitution (and so their molecular weight) is unlmown ; but although there 
 are individual differences of composition, especially between animal and 
 vegetable proteids, their average percentage composition may be stated as 
 follows (Hoppe-Seyler) : — 
 
 H N C S 
 
 From . . 20-9 6-9 15-2 51-5 0-3 
 
 To . . . 23-5 7-3 17-0 54-5 20 
 
 Thus more than half of a given weight of proteid bodies is composed of 
 carbon, while they contain about 16 per cent, of nitrogen. The proteids 
 taken in as food are derived both from animals and plants ; and, as far as 
 is at present known, there is no difference in nutritive value between the 
 proteids from these two sources. Considered as food, they may be divided 
 into two groups : one, true proteids, the members of which are of equal 
 nutritive value, and are capable of sustaining the N-equilibrium of the 
 body ; the other, albuminoids, which are not equal in nutritive value to the 
 first group, and are not capable of performing completely the functions of 
 proteid food. 
 
 This second group contains substances obtained only from animals — such 
 as gelatin [ossein^), cliondrin, and keratin. Gelatin, the only important member 
 of this group, contains a larger percentage of nitrogen than the ordinary 
 proteids — viz. from 17'8 to 18'8 per cent. ; it differs also in some chemical 
 reactions, and does not, like most proteids, yield tyrosin on decomposition. 
 
 The first group of proteid foods are the most important ; they may be 
 divided into — 
 
 1. Globulins. — The myosin of muscle, the globulin of the serum of the 
 blood, those contained in the white and yolk of eggs, are examples from the 
 animal kingdom, while from the vegetable kingdom are the globulins con- 
 tained in the seeds of Leguminosse and of the cereals. 
 
 2. Albumins. — The albumin of the serum, and egg-albumin. 
 
 3. Insoluble Proteids.'^ — The fibrin of the blood and the gluten of wheat. 
 These three classes have one common characteristic, they are coagulated 
 
 by heat ; when coagulated, as in the process of cooking, they are insoluble 
 in water and dilute acids or alkalies, but are readily digested and rendered 
 soluble by the gastric and pancreatic juices (pepsin or trypsin). 
 
 4. Albumoses. — These are closely related to peptones, and are foimd in 
 the cereals, and are taken as food in wheaten flour, rye, rice, and barley. 
 They are probably widely distributed in the vegetable kingdom, and are 
 formed by pepsin from the ordinary proteids of foods (Classes 1 to 3). 
 These animal albumoses are often administered in partially digested foods to 
 invalids : they are the precursors oi peptones, which also belong to this class 
 of proteids. 
 
 5. A fifth class of food-proteids includes the casein of milk, and tbe legu* 
 
 • There is practically no difference between ossein and gelatin (Schiitzenberger). 
 ' That is, those insoluble in water and in saline solutions at ordinary temperatures. 
 
FOOD 895 
 
 min ^ and conglutin of peas, beans, &c, (Leguminosse). Classes 4 and 5 have 
 the common characteristic of not being precipitated, and thus not coagu- 
 lated, by boiling their solutions. The albumoses and peptones do not require 
 so complete a digestion as the casein of milk. 
 
 As an appendix to Class 5 may be mentioned syntonin or acid albumin, 
 which exists in some foods (e.g. meat) and alkali albumin : these are formed 
 by the action of dilute acids and alkalies on ordinary proteids, and are not 
 precipitated from solution by boiling. 
 
 Non-nit7'ogenous Organic Foodstuffs 
 
 These are fats and carbohydrates. 
 
 Fats. — In the majority of diets used by different nations, fat is an added 
 constituent. It is absorbed by the body chiefly in the form of neutral fat, 
 but also in the form of fatty acids and of their compounds, alkaline soaps. 
 The neutral fat taken as food always contains free fatty acids in greater or 
 less proportion, and in some foods {e.g. cheese) the fatty acids are in large 
 proportion. 
 
 Fats are compounds of the triatomic alcohol glycerine, C3H5 (0H)3, and 
 fatty acids. These fatty acids belong to two series : 1, monobasic acids, of 
 the general formula CnH2i,._iO(OH), such as palmitic acid, C16H32O2, and 
 stearic acid, C18H36O2. The fats formed are called palmitin and stearin, 
 both solid compounds. 2. x\cids of the acrylic acid series, with the general 
 formula CnH2n-30(OH), such as oleic acid, C18H34O2. Olein is a liquid 
 fat. 
 
 All fats contain carbon, hydrogen, and oxygen, and differ from carbo- 
 hydrates in the fact that the oxygen is proportionately less than will form 
 water (HgO) with the hydrogen contained in the molecule. In food there is 
 a mixture of neutral fats with free fatty acids ; the solid fats are generally 
 mixed with olein. (For fats present in different foods, see separate accounts 
 of articles of diet.) 
 
 Carbohydrates are derived chiefly from vegetable foods, and are mostly 
 taken as food in the form of starch. They all contain carbon, hydrogen, and 
 oxygen, the hydrogen and oxygen being in the proportion to form water. 
 
 1. The group of glucoses (C6Hi206)n consists of three forms; (a) grape- 
 sugar (dextrose, glucose), {b) galactose, a product of milk-sugar, and (c) 
 IcBVulose (invert-sugar), which is contained in the juices of plants and in 
 honey ; {d) inosite, isomeric with grape-sugar, and found in muscle and 
 some other animal foods, and in beans and the juice of the grape. 
 
 2. A second group differs from the first group in containing one molecule 
 of water less than the double molecule of glucose; thus 2(C6Hi206)— HjQ 
 = C12H22O11. To this group belong {a) milk-sugar or lactose, occurring in 
 milk ; (&) maltose, which is the end-product of the digestion of starch in the 
 digestive tract ; (c) saccharose or cane-sugar, occurring in many plants, as 
 the sugar-cane and the beet. 
 
 3. A third group contains bodies with the formula (CeHjoOg)!!, and are 
 related to members of the second group by considering them as containing 
 one molecule less of water. Thus milk-sugar, C12H22O11 — H2O = starch, 
 2(C6Hio0.5). To this group belong [a) glycogen (' animal starch '), found in 
 certain articles of diet, such as liver and molluscs ; {b ) dextrine, associated 
 with starch in many foods and formed from starch m the digestive tract ; 
 
 ' It is probable that legumin and conglutin are not really ' vegetable caseins,' but are 
 artificial products, the alkali used in their extraction transforming the globulin present 
 (Vines). The proteids of vegetable foods require complete reinvestigation. 
 
396 HYGIENE 
 
 (c) amylum or starch, found in vegetable cells ; {d) cellulose. This last, 
 although of no great value as food to man, is of value to herbivorous animals. 
 The presence, however, of indigestible cellulose in the food of man has an 
 effect, as will be pointed out, on the complete digestion and absorption of 
 digestible foods. 
 
 Vegetable Acids 
 
 These are grouped together, although they belong to different chemical 
 groups, because they perform the same physiological function : their salts 
 are converted into carbonates in the body, and thus preserve the alkalinity of 
 the blood, tissues, and secretions (e.g. pancreatic juice). 
 
 Acetic acid, C2H.,02, and lactic acid (oxypropionic acid), CgHi^Oa, belong 
 to this group : they are related to fatty acids, but in their function as food 
 differ greatly from fatty acids. 
 
 The other acids belonging to this group are also allied to the fatty 
 acid series : oxalic acid, H0C2O4 ; tartaric acid, C4HQO6 (dioxysuccinic acid) ; 
 citric acid, CqH.^O'j ; malic acid, CiHgO^ (oxysuccinic acid). This group 
 differs from the first in the fact that they have an excess of oxygen in their 
 composition — more than will form water with the H they contain. 
 
 The most important of these vegetable acids are tartaric and citric acids. 
 
 Inorganic Foodstuffs 
 
 The salts taken in as food which are of importance to the organism are 
 sodium chloride, potassium chloride, the phosphates of calcium and mag- 
 nesium, and iron compounds. Sulphates are of minor importance. The 
 carbonates of sodium (NagCOg and NaHCOg) are of great importance in the 
 organism : they are, however, chiefly derived from the vegetable acids taken 
 with the food (see p. lOO.) 
 
 The Change of Foodstuffs in the Body — theik Nutkitive 
 
 Functions 
 
 Nitrogenous foodstuffs are necessary to animal life : they are the only form 
 in which nitrogen can be assimilated by the organism so as to act as nutri- 
 ment to the tissues. When taken into the digestive tract, both animal and 
 vegetable proteids (Classes 1-3) become transformed by the pepsin-hydro- 
 chloric acid of the gastric juice into syntonin, albumoses, and peptones ; 
 by the trypsin of the pancreatic juice into peptones and an intermediate 
 body, while part of the peptone is further split up into two nitrogenous 
 bodies, leucin and tyrosin. These crystalline bodies cannot replace proteids 
 in a diet. They are amido-acids, and like other bodies of their class, except 
 asparagin, they cause a decomposition of proteid in the body if they are 
 given in the food as part of the proteid.^ 
 
 Gelatine is also transformed into albumoses in the stomach and small 
 intestine ; keratin is not digested in the stomach but only by the pancreatic 
 juice in the small intestine. The digested products of these bodies differ in 
 chemical reactions from those of Classes 1-3. The difference of nutritive 
 value is greater than that of their chemical reactions. 
 
 Some of the native proteids taken in as food may be absorbed as such 
 (Briicke), but most physiologists are agreed that proteids are absorbed from 
 
 ' See P. BaUmann, Inaug. Dissert. Miinster, 1885. Quoted by Konig, Nahrungs- 
 mittellehre, Bd. i. p. 121, 3rd edit. 
 
FOOD 307 
 
 the digestive tract in the form of albumoscs and peptones, and, according to 
 the researches of Hofmeister,^ von Ott,^ Popoff,^ and Brinck, they are 
 transformed by the mucous membrane of the stomach and intestine into 
 serum-albumin. Albumoses and peptones thus form an important constituent 
 of the artificial foods for invalids ; they do not, however, possess the same 
 nutritive value as the ordinary proteids of food. The well-known experi- 
 ments of Plosz and Maly tend to show that they are equal in nutritive 
 value to albumin and other proteids : they fed a dog, for example, on pep- 
 tone, fat, and carbohydrate for a period of eighteen days, and found that at the 
 end of that time it had gained considerably in weight. According to Voit, 
 however, rats in whose diet peptones are substituted for the ordinary pro- 
 teids of food succumb after a period of seven months. It is possible that 
 when a large quantity of peptone is given, much of it is split up by the 
 pancreatic juice into leucin and tyrosin, and is thus lost as food to the 
 organism. 
 
 We may take the fact as certain that the nitrogenous foods absorbed 
 from the digestive tract become, sooner or later, transformed into one of 
 the proteids of blood ; they can in this form be utilised by the tissues. We 
 know also that the end-products of the changes they undergo in the body 
 are nitrogenous excretive matters, urea and uric acid. Some considerations in 
 relation to the metabolism of proteids in the body are, therefore, of extreme 
 importance from a dietetic point of view : these will now be reviewed. The 
 cells which compose the animal body are formed of 'protoplasm,' whether 
 metamorphosed into the nerve-cell, the muscle-fibre, or the chief structures 
 of other tissues. Prom one point of view protoplasm may be considered 
 as ' living ' proteid, since after its death the greater part of it consists of the 
 proteids or nitrogenous substances which are taken in as food. Two con- 
 siderations are of importance with regard to the life of the cellular elements 
 of the body. (1) In order that they may continue to exist, they must be 
 supplied with nitrogenous food in the form of proteids. (2) By their means 
 the physiological processes of the animal body are carried on. When the body 
 is deprived of nitrogenous food, the tissues do not at once cease their activity, 
 for they have a store of nitrogenous food on which they can draw. This 
 store exists partly in the blood, the so-called ' circulating proteid,' and partly 
 in the tissues themselves : when this is exhausted, the tissues then begin 
 to waste from the insufficiency of nitrogenous food. 
 
 Practically speaking, the nutrition of the nitrogenous tissues means the 
 nutrition of the body. Thus the physiological activity of glands, of muscles, 
 of the nerve-cells, of the connective-tissues, of the spermatozoa, and of the 
 ovum depends on the food supplied to and assimilated by them. As regards 
 glands, their secretion is, in the case of the digestive glands, rich in proteid 
 substances which are closely associated with the active agents of the secretion, 
 the ferments. In the connective tissue, also, the fat is stored up by means 
 of the cells it contains ; it is not simply located in the tissues ; its storing up 
 is due to the assimilating activity of the cell, developed in one particular 
 direction, viz. that of taking in fat. The liver-cells, moreover, take up most 
 of the carbohydrates digested in the intestine, and this assimilation is due 
 to the activity of the living nitrogenous cell. Therefore all the physiological 
 processes of the body occur by means of its nitrogenous cell-elements, and 
 the food we eat to nourish the tissues of the body must be taken up by the 
 
 ' Arch. f. exper. Path. Bde. xix. and xs. 1885. 
 * Dubois-Eeymond's Archiv. 1883. 
 » Zeits.f. Biologic. 1889. 
 
898 HYGIENE 
 
 cell-elements before it produces its effect. The process of oxidation is also 
 closely associated \\dtb the activity of the cell-elements of the tissue, so that, 
 as Pettenkofer and Voit have shown, ' the nitrogenous substances composing 
 the textures of the body determine the absorption of oxygen,' and it is not 
 that the ' absorption of oxygen determines the changes in the tissues ; ' 
 oxidation in the body, moreover, is not proportional to the amount of oxygen 
 inspired, as Lavoisier and Liebig thought, but to the necessity of the tissues 
 for oxygen. 
 
 The proper and regulated supply of nitrogenous food to the organism is, 
 as is evident from what has just been said, of prime importance. But in the 
 matter of food, it is difficult, if not impossible, to point out that one food- 
 stuff is more important than another, difficult where a deficiency of any par- 
 ticular foodstuff' is detrimental to healthy existence. Nitrogenous food, for 
 example, is essential to life, but so are salts and water, and so, again, are 
 fats and carbohydrates. And although the rdle played by the individual 
 foodstuff' may be pointed out, the effect of the mixture of foodstuffs is the 
 chief physiological factor in considermg food. The results of feeding ex- 
 periments (in animals) have shown that the proteids taken as food are, to 
 some extent, the source of the fat of the body and of the glycogen found in 
 the Hver and muscles ; so that, besides being essential to the life of the 
 nitrogenous tissues, they have a nutritive relation to the other two classes 
 of organic foodstuffs, fats and carbohydrates. The relation of proteids to 
 inorganic foodstuff's will be discussed under the head of the latter. 
 
 Proteid-sparing Foods 
 From what has been said, it is evident that an excess of proteid food 
 would throw an excess of work on the nitrogenous tissues. Thus it is found 
 that the decomposition of proteid in the body varies with the amount taken 
 as food ; the excretion of urea is greatest with animal diet and less with a 
 diet of vegetable food poor in proteid.^ To preserve health, the proteid taken 
 must equal that destroyed. No constant figure can be given, however, of the 
 amount of proteid taken as food, for with every individual there is a maxi- 
 mum and a minimum of intake. It is evidently of advantage to the organism 
 if the amount of proteid taken in as food can be dimhiished by admixture 
 with other foodstuffs, without, at the same time, affecting the organism 
 injuriously, because the diminution of proteid food takes work off the tissues 
 and the digestive organs. Such foodstuffs wliich in a diet allow the proteid 
 food to be diminished in quantity are called proteid-sparing foods. The 
 chief of these are gelatine, fats, and carbohydrates. .Gelatine has not the 
 same nutritive value as myosin of flesh, &c. ; it cannot completely replace 
 such proteids in a diet. But it has a certain value, for on a diet containing 
 two parts of ordinary proteid to one of gelatiae, an animal can maintain 
 health ; a fact of both physiological and practical importance. In a dog, for 
 example, as Voit has shown, N-equilibrium is established on a diet in which 
 the nitrogenous food consisted of 400 grammes proteid and 200 grammes 
 gelatine. Gelatine is easily digested in the stomach, but is rapidly oxidised 
 in the body into urea, the excess of which in the system causes diuresis. 
 Chondrin and keratin are far behind gelatme in nutritive value ; and as 
 they form only a fractional proportion of food they possess no great practical 
 value. Weiske and others have shown that asparagin (amido-succinamic 
 acid) is a proteid-sparing body in herbivora ; in carnivora this action is not 
 certain.^ 
 
 ' See Lehmann, Journ. f. p-aht. Chemie, Bd. ii. 1850, p. 447. 
 * Cf. Konig, op. cit. p. 110. 
 
FOOD 899 
 
 Large quantities of animal food (meat) may be taken : Eanlce took as 
 much as 2000 grammes (4-^- lb.), and Eubner, 1400 grammes (3 lb.), in a 
 day. This is of no advantage ; it throws great work on the tissues, and, 
 moreover, such a diet cannot be maintained for any length of time. Experi- 
 ments are not wanting, both in animals and in man, to show that the addition 
 of fat to a diet of proteid is of advantage. In a dog, for example, which has 
 a diet of 1200 grammes of flesh daily, more proteid will be destroyed in 
 the body than is taken as food, while an equilibrium between intake 
 and destruction of proteid is obtained if the diet consist of 500 to GOO 
 grammes of meat and 200 grammes of fat (Eubner). The addition of fat has 
 here acted as a proteid-sparing food. Carbohydrates act in a similar manner. 
 No definite proof is forthcoming, whether such substances as coca 
 (cocaine) and Kola nut (caffeine), &c., are proteid-sparing materials : such 
 experiments as have been performed tend to show that these substances 
 may diminish the intake of food, but are eventually detrimental to the 
 organism, owing to the effect of their active principles on the central nervous 
 system. They may, however, have some use in hard work, such as in forced 
 marches and efforts of endurance. 
 
 Fats. — The use of fats in the organism is that they are sources of energy 
 and of heat to the body. In the majority of diets of the nations of the world 
 fat finds a place, and in some cases (that of the Esquimaux) it is greatly 
 increased in the dietary. In hard work, too, an excess of fat is taken. What- 
 ever the mixture of fats taken in as food, the body-fat always has the same 
 composition : this fact agrees with the conclusion that the deposition and 
 metabohsm of fat in the body is due to cell- activity, and that the fat in part 
 comes from the proteid and from the carbohydrate food. 
 
 Carbohydrates not only act as proteid-sparing foods, but they are also 
 fat-sparing. They diminish the consumption of fat by being a source of 
 energy in the body, and thus when present in a diet in which but little 
 fat is present, they diminish the oxidation of fat in the body. They are also 
 a source of fat, as has been abundantly proved by the experiments of Lawes 
 and Gilbert, and others. Carbohydrates, however, differ from fats in that the 
 amount ingested is proportional to the quantity of carbonic acid (COg) excreted : 
 there is no such relation with fats. For oxidation, carbohydrates require 
 only sufficient oxygen to unite with their carbon, since the hydrogen and 
 oxygen are in the proportion to form water ; but fats require oxygen to 
 oxidise their hydrogen as well as their carbon. The question whether fats 
 and carbohydrates can replace each other completely in a dietary is not as 
 yet definitely answered. Practically, however, it is in part settled by a con- 
 sideration of the diets used by civilised nations : in all of these, both fats 
 and carbohydrates find a place. The first question, therefore, as to whether 
 it is possible to maintain health on a diet of proteids, fats, salts, and water, 
 and on one of proteids, carbohydrates, salts, and water, is one of greater 
 physiological than of practical import. It is, however, an important point 
 to discover in what proportion fats and carbohydrates are mutually inter- 
 changeable in a dietary. Carbohydrates are cheaper than fats, and thus 
 form a large part of the diet of the poor ; and this is a practical aspect of the 
 question. Life and a certain degree of health can be maintained on a diet 
 of proteids, fats, salts, and water, and fat seems essential in the dietary of man. 
 If an excess of fat, however, be present in the diet, it is not digested, but 
 passes away with the faeces and favours decomposition in the digestive 
 organs, which are thus put out of order. An excess of carbohydrates, on the 
 other hand, owing to the large bulk of food taken, also deranges the digestion 
 (see under Digestibility of Food, p. 419). The conclusion, therefore, seema 
 
400 HYGIENE 
 
 to be in favour of an admixture of fats and carbohydrates in the diet. As, 
 however, these foodstuffs perform similar functions in the body, they can be 
 expressed in dietetic terms of each other (see Nutritive Value of Food- 
 stuffs, p. 401), 
 
 Inorganic Constituents of Food 
 
 These play an important part in the dietary. Without them, indeed, 
 life is no longer possible. 
 
 Water is necessary for the proper carrying on of all the chemical and 
 mechanical functions of the body, for producing a medium for the solution of 
 the digestive juices, for aiding the absorption of the products of digestion, for 
 tlie excretion of substances from the body, and for the dispersion of heat 
 from the lungs and skin. The water in the body is chieliy derived from that 
 taken in as food, but a portion is obtained by the oxidation of the hydrogen 
 in tissues, about 29G grammes daily. A want of water tends rapidly to 
 death. 
 
 Sodium chloride (NaCl) is essential to life ; its complete withdrawal from 
 the food leads to dissolution. Since it exists in very small proportion in 
 vegetable foods, it is a necessity to vegetable feeders. In the making of 
 bread, for example, the sodium chloride added supplies the deficiency of 
 sodium and chloride which exists in flour. With animal feeders the use 
 of common salt is not so peremptory, since the fluid which bathes muscular 
 tissue hke other animal fluids contains a sufficient quantity. The uses of 
 chlorides in the organism are very important ; they keep in solution the 
 globuhns of the blood and other fluids ; they are closely associated with 
 the proteids of the tissues, although the utility of this association is at 
 present unknown ; they are the source of the hydrochloric acid of the gastric 
 juice, so that a deficiency of chlorides in the food leads to digestive dis- 
 turbances, the hydrochloric acid in the stomach diminishing while the 
 sodium chloride of the blood is not affected to any great extent.^ Albumin- 
 uria is a secondary result of ' chlorine-hunger.' 
 
 Phosphates are also essential to hfe, especially to the growing organism ; 
 and where development is taking place, there are ahvays present phosphates, 
 sulphur, and calcium. Young animals, as Kemmerich has shown, when fed 
 with food poor in potassium phosphate, soon die, the muscles being chiefly 
 affected. ^ In the body, phosphates are united with alkalies, sodium, potas- 
 sium, calcium, and macjnesittm. 
 
 The sodium salts are in the form of normal sodium phosphate (Na3P04) 
 and di-sodium phosphate (Na2HP04), while the potassium is salt in the 
 form of di-potassium phosphate only (K2HPO4). Phosphates, like chlorides, 
 are peculiarly associated with proteids, although the utility of this association 
 is not understood. The phosphates of calcium and magnesium have special 
 functions to perform, since they constitute the chief solid parts of bone. 
 They are of great importance, therefore, to the growing organism. When 
 the food is deficient in calcium, and to a less extent of magnesium, the bones 
 of growing animals are badly developed, and may become rickety .^ There 
 is apparently some relation between the ingestion of calcium salts and of 
 sodium chloride, for the former may be abundant in the food, and yet be for 
 the most part excreted in the faeces combined with fatty acids. This non- 
 absorption of calcium, so important a body to the child, may be due, as 
 
 ' Forster, Zeits. f. Biologic, Bd. ix. 1873, p. 342. 
 2 Pflliger's Archiv, Bd. ii. 1869, p. 85. 
 
 ^ Eoloff, Arch. f. wisscn^chaftl. u. inaht. Thicrhcilk. Bd. v. p. 152 ; Dusart, De V Inani- 
 tion min&raU. Paris, 1874. 
 
FOOD 401 
 
 Forster lias pointed out, to the diminution of the hydrochloric acid in the 
 gastric juice, owing to a deficiency of chlorides in the food : it is through 
 the acid gastric juice that calcium salts are absorbed. 
 
 The carbonates present in the body are derived from two sources : a small 
 quantity is taken in with the food, but the greater part is derived from the 
 vegetable acids of the food — acetic, tartaric, citric, malic, and lactic — which 
 are changed into carbonates in the system. Some of these acids (lactic, for 
 example) are probably derived in part from the splitting up of carbohydrates 
 in the body ; so that m this indirect way carbohydrates may aid in maintain- 
 ing the alkalinity of the blood and animal fluids — both the interstitial fluids 
 of the tissues and the alkaline secretions, such as that of the salivary glands 
 and of the pancreas. Besides this important function, carbonates in the 
 form of carbonate of calcium form an integral part of bony tissue. 
 
 Sulphates exist in only small quantity in the body : they are not of such 
 importance as the salts already considered, although organic sulphur (such 
 as exists in proteids) is essential to growth. A small quantity of sulphates 
 is taken in with the food and a little is formed in the body by the oxidation 
 of albuminous substances containing sulphur. 
 
 Iron is essential to health and to life : it forms an important part of the 
 haemoglobin of the red corpuscles. It is contained in many foods, especially 
 animal. 
 
 Nutritive Value of Foodstuffs 
 
 In the preceding section a short account has been given of the part 
 played by the different foodstuffs in the body. It is now necessary to discuss 
 their nutritive value. It is evident that the nutritive value of the salts and 
 water of food is easily determined, since they do not undergo the great 
 chemical change that proteids, fats, and carbohydrates do in the organism.. 
 Their nutritive value, therefore, may be expressed in terms of the quantity 
 ingested, with the requisite proportion of the different saline constituents. 
 But with proteids, fats, and carbohydrates the case is different : the changes 
 they undergo in the body are complicated, and the functions they perform 
 are numerous, and at present incompletely understood, so that it is impossible 
 to so express their nutritive value accurately. An approximate estimate, 
 however, is not without its importance. All the processes of the body are 
 attended with the manifestations of energy, this being in two forms, 
 mechanical labour and heat. The process going on in all the cells of the 
 body are thus manifestations of energy. The contraction of muscles, the 
 beat of the heart, and the metabolism of cells develop energy in their occur- 
 rence. With regard to mechanical labour, the amount of energy expended 
 by the body may be calculated ; a good day's work, for example, would be 
 equal to about 150,000 metre-kilogrammes.^ With heat, however, it is 
 different. The amount formed in, the body has not yet been accurately 
 measured, in spite of numerous experiments. A useful proportion to recol- 
 lect, however, between the amount of mechanical labour and heat expended 
 by an adult in a fair day's work is one- sixth or one-fifth mechanical labour 
 to five-sixths or four-fifths heat. Food is the means by which this loss of 
 energy to the body is made good. The foodstuffs possess a certam amount 
 of potential energy which may be expressed either in terms of heat or of 
 
 ' The amount of energy required to raise 1 kilogramme 1 metre high is taken as the 
 unit of force : on the English scale, the unit is a foot-pound. 
 
 The amount of heat required to raise 1 gramme of water 1 degree Centigrade is the 
 unit of heat, or 1 calorie. 
 
 VOL. I. D D 
 
402 
 
 HYGIENE 
 
 mechanical labour. This potential energy is different in each particular kind 
 of foodstufifs, not only in the classes of proteids, fats, and carbohydrates, but 
 also in the individual members of each of these classes. The potential energy 
 of any foodstuff is calculated by estimating the amount of heat used on the 
 complete combustion of a certain weight of the substance ; and this heat can 
 be expressed in foot-poimds or metre-ldlogranimes by calculating how much 
 work the heat can do. 
 
 By this means the following calculations have been made : — 
 
 Substance — one gramme (ili-ied) 
 
 Give rise to gr.-degrees ' 
 
 Metre-kilogrammes 
 
 Casein 
 
 5,855 
 
 2,488 
 
 Peptone 
 
 4,87& 
 
 2,072 
 
 Ox-tlesh 
 
 5,724 (5.103)- 
 
 2,432 (2,161) « 
 
 Gelatine 
 
 5,493 
 
 2,334 
 
 Gluten 
 
 6,141 
 
 2,610 
 
 Legumir 
 
 5,573 
 
 2,368 
 
 Ox-fat 
 
 9,686 (9,009)- 
 
 4,116 (3,841)2 
 
 Palmitin 
 
 8,883 
 
 3,775 
 
 Stearin 
 
 9,036 
 
 3,840 
 
 Olein 
 
 8,958 
 
 8,807 
 
 Butter 
 
 7,264 2 
 
 3,077 * 
 
 Starch 
 
 4,479 
 
 1,903 
 
 Arrowroot 
 
 3,912 2 
 
 1,657 * 
 
 Dextrose 
 
 3,989 
 
 1,674 
 
 Maltose 
 
 4,163 
 
 1,769 
 
 Cow's milk ...... 
 
 5,733 
 
 2,436 
 
 Human milk 
 
 4,837 
 
 2,055 
 
 Potatoes 
 
 4,234 
 
 1,799 
 
 VV beaten bread 
 
 4,351 
 
 1,849 
 
 Eice 
 
 4,806 
 
 2,042 
 
 Peas 
 
 4,889 
 
 2,077 
 
 Alcohol 
 
 6,980 
 
 2,966 
 
 Liebig's extract of muscle 
 
 4,400 
 
 1,870 
 
 Urea 
 
 2,537 (2,206)- 
 
 1,078 (934)2 
 
 These are figures for the complete oxidation of the foodstuffs, but in the 
 body it is only the fats and carbohydrates which are completely oxidised ; the 
 proteids get no farther than the stage of urea. In expressing, therefore, the 
 available potential energy of food proteids, the potential energy of urea 
 (2,537 calories) must be subtracted. One gramme of dry proteid gives rise to 
 about ^ gramme urea ; therefore, according to Frankland's figures, the 
 available potential energy of one gramme of proteid is as follows : — 
 
 
 Gr.-deg. 
 
 Met.-kilo. 
 
 1 gramme of dried ox-flesh 
 
 . 5,103 
 
 2,161 
 
 77ltnUS 
 
 
 
 ^ gramme urea 
 
 . 735 
 
 311 
 
 Available potential energy of proteid . 
 
 . 4,368 
 
 1,850 
 
 Danilewsky gives the available energy of one gramme of albumen as 
 5,100 calories (5,945 minus one-third of 2,537). 
 
 From what has been said, it is evident that foodstuffs may be expressed 
 in equivalents in terms of energy ; to foods which when burnt yield the same 
 number of calories the term isodynaviic has been applied. From the point 
 of view of energy we may say, therefore, that so much proteid is isodynamic 
 with so much fat or carbohydrate. Eubner has calculated that 100 grammes 
 
 ' One gramme-degree, or calorie, is equivalent to 0-425 kilogramme-metre ; or, better 
 expressed, one kilogramme-degree is equivalent to 425 kilogramme-metres. 
 
 - Frankland, Fhii. Mag. xxxii. p. 182. The other figures are from Danilewsky. 
 F. Stohmann and others give somewhat different figures. See Journ.f.praktische Cheniie, 
 N.F. Bd. xxxi. p. 273 ; Bd. xxxii. pp. 93, 407, 420. 
 
FOOD 403 
 
 of animal albumin = 52 grammes of fat = 114 grammes of starch = 129 
 grammes of dextrose. Also that 100 parts of fat are isodynamic with 232 
 parts of starch, 234 parts of cane-sugar, and 250 parts of dry dextrose, 
 making a mean of 250 parts of carbohydrate. ^ 
 
 From a dietetic point of view, however, it is not so much a question of the 
 energy developed by the burning of the foodstuffs outside the body, but of the 
 amount of their potential energy which is available during combustion in the 
 organism. Theoretically, the potential energy ought to be equal to the 
 energy developed by them in the body ; and this was Liebig's notion when 
 he stated that 100 grammes were equivalent to 240 grammes of carbohydrates 
 (Rubner says 250 grammes). But owing to the varying digestibility and 
 absorption of foodstuffs, and probably to many metabolic conditions in the 
 body with which we are at present imperfectly acquainted, only a portion of 
 the potential energy of foodstuffs is actually available to the organism. 
 Eubner has stated that in man the available heat units for 1 gramme of 
 albumin are 4,100 ; 1 gramme of fat, 9,300 ; and 1 gramme of carbohydrate, 
 4,100. These figures differ considerably from the total potential energy of 
 the foodstuffs. By another method, Pettenkofer and Voit have come to the 
 conclusion that 100 grammes of fat is equivalent to 170 or 180 grammes of 
 carbohydrates a dietary ; a conclusion which may be taken as more correct 
 than deductions from mere calculations of potential energy. 
 
 This question of potential energy of foodstuffs is therefore merely an indi- 
 cation of their nutritive value in a particular direction. To say, for example, 
 that so much fat is isodynamic in the body with so much carbohydrate does 
 not mean that it is of no consequence to the health of the organism whether 
 the non-nitrogenous foodstuffs of the diet be given in the form of fat or of 
 carbohydrate. As we have seen, not only physiological considerations, but 
 the custom of communities, have decided that health is best maintained when 
 carbohydrates and fats form part of the diet. 
 
 Other points must be considered in dealing with the nutritive value of 
 foods and foodstuffs : the chief of these are their digestibility, associated 
 closely with the changes produced by cooking and the preparation of food and 
 with the bulk of food taken ; the interaction of the foodstuffs and the effect 
 of adventitious substances in food ; the effect on food of food-accessories. 
 These subjects will be discussed afterwards. 
 
 Another question arises in considering the nutritive value of foods, and 
 that is whether individual members of the classes of proteids, fats, and carbo- 
 hydrates do not differ from each other in nutritive value. There is not much 
 known on this point. We have seen that among proteids, the members of 
 the sub-class of albuminoids (gelatine, &c.), have not the same nutritive value 
 as ordinary proteids ; but it is usually considered that the animal proteids 
 (myosin, egg-albumin, &c.) have the same nutritive value as the vegetable 
 proteids (gluten, legumin, &c.) This has been confirmed by the carefully 
 conducted experiments of Dr. Rutgers on himself.^ There are, however, 
 undoubtedly individual differences in nutritive value in proteids, which 
 further research will perhaps elucidate ; but these differences are perhaps 
 not great, and it may be concluded that man has chosen the three best pro- 
 teids for his food in the myosin of meat, the casein of milk, and the gluten 
 of bread. 
 
 The differences in nutritive value of fats seem to depend almost solely 
 on their digestibility (see p. 420). 
 
 ' Zeits. /. Biol. 1883, p. 312. Quoted by Konig. 
 = Zeits. filr Biol. Bd. xxiv. 1887, p. 351. 
 
 D D 2 
 
404 HYGIENE 
 
 The differences in carbohydrate foods cannot at present be correctly 
 estimated. There is very httle evidence to show that starch, dextrose, 
 maltose, and cane-sugar differ in nutritive value. Lawes and Gilbert, how- 
 ever, consider that cane-sugar is rather more fattening than starch.^ 
 
 The question as to the most advantageous form in which to take proteids, 
 fats, and carbohydrates is not simply one of the nutritive value of mixed 
 foods — such as meat, bread, potatoes, &c. — it is a question of digestibility, bulk 
 of food, &c. ; so that the discussion of this point is best taken under the con- 
 sideration of diet. 
 
 Diet and Dietaries 
 
 To preserve health, a diet containing proteids, fats, and carbohydrates, 
 with salts and water, is necessary. It has been pointed out that proteids, salts, 
 and water are essential to life ; and it has been shortly discussed to what 
 extent fats and carbohydrates are mutually interchangeable in a dietary. 
 Whatever may be the physiological import of the interchangeability of fats 
 and carbohydrates, the question is practically settled by the consideration 
 that both in the diets of nations and in the standard diets calculated from labo- 
 rious research it has been found advantageous to include both fats and carbo- 
 hydrates. For practical purposes, therefore (and diet is essentially a practical 
 question), we cannot consider the two classes of non-nitrogenous organic 
 foodstuff's as completely interchangeable, notwithstanding, as has been pre- 
 viously pointed out, the fact that their physiological roles are very similar. 
 
 Under the heading Diet we have to consider the quantity of foodstuffs 
 requisite to preserve health. This quantity is, however, not fixed ; each indi- 
 vidual differs in the amount of food required to support health, and in each 
 individual there is a minimum and maximum of the daily ingesta, beyond 
 the bounds of which health is not maintained. Diet is also affected by 
 several conditions. To some extent sex influences it : age greatly affects the 
 daily ingestion of food ; the dietary of childhood (the period of growth), that 
 of adult hfe (the period of vigour), and that of old age (the period of decay 
 or of inactivity) differing in important particulars. Work has great influ- 
 ence on diet ; climate and the temperature of the air have only a slight effect. 
 
 The standard diets which have been compiled from the results of experi- 
 ments vary to some extent in the quantity of foodstuffs contained in them, 
 so that they can only be considered as approximate. The methods by which 
 they have been obtained may be briefly stated. A healthy individual is 
 selected, and the exact quantity of foodstuffs is estimated by experiment, 
 requisite to preserve an equilibrium between the amount of carbon and 
 nitrogen taken into the body and that discharged from it. This method has, 
 however, to be corrected by two other methods — 1, estimating the amount of 
 foodstuffs present in the daily food used by communities of men, that used in 
 famihes, by labourers of a class, and in ships ; 2, by weighing the amount of 
 daily food uniformly used by a single healthy individual, and then estimating 
 the quantity of combustible foodstuffs. 
 
 By experiments of this kind, the diets of subsistence, during rest and 
 during tvork, have been calculated. The diet of subsistence is of physiological 
 interest only, because it is calculated only in proportion to the internal 
 needs of the organism. But such absolute rest is not possible in health ; so 
 that on a subsistence diet a man would waste. The diet of rest implies 
 very little exercise : that of work varies with the amount of work done. 
 
 In the following tables the foodstuffs are reckoned in grammes as water- 
 free, the daily amount of water requisite being placed under a separate 
 
 ' Brit. Assoc. Be])ort, 1854. 
 
FOOD 
 
 W. 
 
 Iisading, and the calculation is for a man of average weight, 68 kilogrammes, 
 or 150 pounds. 
 
 - 
 
 Subsistence diet 
 (Smith and Play fair)' 
 
 Average diet of rest 
 (weight of man, 60-70 kg.) 
 
 Proteid 
 
 Fat 
 
 Carbohydrate. 
 
 Salts 
 
 Total 
 
 Grammes 
 
 06 
 
 24 
 
 330 
 
 14 
 
 Oz. avoir. 
 
 2-32 
 
 0-84 
 
 11-5 
 
 0-5 
 
 Grammes 
 
 100 
 
 50 
 
 400 
 
 Oz. avoir. 
 
 3-52 
 
 1-76 
 
 14-08 
 
 434 
 
 15-16 
 
 — 
 
 — 
 
 The diet of rest, however, varies like other diets. Thus Pettenkofer and 
 Toit ^ found that in a strong workman, during rest, the diet contains 137 
 grammes of proteid, 72 of fat, and 352 of carbohydrate. He gave, moreover, 
 to a resting soldier a diet containing 86"3 grammes of proteid, 108*9 grammes 
 of fat, and 331-4 grammes of carbohydrate, and found that he lost 10 grammes 
 of proteid daily from the body. 
 
 Diet for a Man iveighing 150 lb. during Work 
 
 - 
 
 Medium work 
 
 Severe work 
 
 Very laborious 
 work 
 
 Molescliott 
 
 Pettenkofer 
 and Voit 
 
 Eanke 
 
 llolescliott 
 
 Smith & Play- 
 fair (average) 
 
 Proteid . 
 
 Fat . . . 
 
 Carbohydrate 
 
 Salts . 
 
 Total dry food . 
 
 Gr. 
 130 
 
 84 
 404 
 
 30 
 
 Oz. av. 
 4-59 
 2-96 
 
 14-26 
 1-06 
 
 Gr. 
 137 
 117 
 352 
 
 30 
 
 Oz. av. 
 4-83 
 4-12 
 
 12-40 
 1-06 
 
 Gr. 
 100 
 100 
 240 
 25 
 
 Oz. av. 
 3-52 
 3-52 
 8-46 
 0-89 
 
 Gr. 
 140 
 
 90 
 434 
 
 32 
 
 Oz. av. 
 4-94 
 3-17 
 
 15-31 
 1-13 
 
 Gr. 
 184 
 
 71 
 570 
 
 40 
 
 Oz. av. 
 6-50 
 2-85 
 
 20-10 
 1-40 
 
 648 
 
 22-87 
 
 636 
 
 22-41 
 
 465 
 
 16-39 
 
 696 
 
 24-55 
 
 865 
 
 30-85 
 
 Of these diets, that of Moleschott's for medium work has been taken as 
 the average diet for the adult man. Eanke's diet, which is superior in that 
 it contains more fat, was calculated from experiments on an individual whose 
 body- weight was 74 kilogrammes (163 pounds). 
 
 Relation of Total Water-free Food in Daily Diet to Body-weight 
 
 - 
 
 Subsistence 
 diet 
 
 Medium work 
 
 Very 
 
 laborious 
 
 work 
 
 Moleschott 
 
 Eanke 
 
 Proportion per kilo, of body-weight . 
 Proportion of total body-weight . 
 
 6-4 
 
 1^6 
 
 9-5 
 
 1 
 
 105 
 
 6-3 
 
 Grammes 
 
 12-7 
 
 1 
 
 78 
 
 From this table it will be seen that Eanke's diet for medium work is 
 actually less than Playfair's subsistence diet, and differs greatly from 
 Moleschott's. Eanke's results may be taken as true for the particular indi- 
 vidual experimented upon, but Moleschott's is a better average diet. 
 
 Amount of Garhon and Nitrogen in Diets. — The carbon and nitrogen of 
 the foodstuffs are the chief elements which undergo metabohsm in the body ; 
 and from one point of view the food ingested may be looked upon as so much 
 carbon, nitrogen, hydrogen, and salts. 
 
 > See E. Smith, Ann. Report to Privy Council, 1863 and 1864 ; also Playlair, 
 Edinburgh Med. PJiilosopMcal Journal, 1854. 
 2 Zeits. f. Biol. Bd. ii. 1866, p. 488. 
 
406 
 
 HYGIENE 
 
 The following table shows the quantity of carbon, nitrogen, &c., in 100 
 grammes of each dried foodstuff : 
 
 100 grammes of dried foodstuff contain of 
 
 Carbon 
 
 Nitrogen 
 
 Hydrogen 
 
 Sulphur 
 
 Proteid (average) 
 
 Fat 
 
 Carbohydrates : 
 
 Starch 
 
 Cane-sugar 
 
 Lactose 
 
 Glucose 
 
 530 
 
 76-5 
 
 411 
 42-1 
 42- 1 
 400 
 
 16-1 
 
 7-1 
 10-9 
 
 115 
 
 Converting Moleschott's diet into terms of carbon, nitrogen, &c., we 
 obtain the followLna: ficfures : — 
 
 Nitrogen . 
 
 20-9 grammes 
 
 or 321 grains 
 
 Carbon 
 
 . 307-0 
 
 4,737 „ 
 
 Hydrogen 
 
 . 11-6 
 
 179 „ 
 
 Sulphur . 
 
 1-8 
 
 28 „ 
 
 Salts 
 
 . 30-0 
 
 464 „ 
 
 Eoughly speaking, therefore, the average diet ouglit to contain in the- 
 form of foodstuffs 20 grammes of nitrogen and 300 grammes of carbon. 
 
 Salts and Water of the Diet. — -The loss of water from the lungs and skin, 
 and in the urme and fteces, is continuous, but varies during rest, during work, 
 and with changes of external temperature. Pettenkofer and Voit ' give the 
 following figures for rest and work : — 
 
 Daily Loss of Water from Body in Grammes 
 
 - 
 
 During rest 
 
 During work 
 
 By urine 
 
 By faeces 
 
 By skin and lungs 
 
 Total .... 
 
 Grammes 
 1,200 
 110 
 930 
 
 Grammes 
 1,150 
 80 
 1,730 
 
 2,240 
 
 2,960 
 
 Part of the water lost is replaced by the combustion of hydrogen in the 
 body : this is equal to 296 grammes daily ; the remainder is made up by the 
 water taken in with the food, which varies from 2,700 to 2,800 grammes daily 
 (70 to 80 ounces). 
 
 The total amount of salts needed daily has been already given, viz. 30 
 grammes. These salts consist of chlorides and phosphates united with 
 sodium, potassium, calcium, and magnesium. Iron is taken in the food 
 united with complex organic compounds. 
 
 The chief salts taken in as food are sodium chloride, potassium, calcium, 
 and magnesium phosphates ; the first chiefly from animal foods or added to 
 the food, the latter chiefly from vegetable food ; milk, however, contains a 
 sufficient proportion, not only of sodium chloride, but of potassium and 
 calcium phosphates and iron. Owing to the deficiency of sodium chloride 
 in vegetable food, it is a necessity which is added to the food of those who 
 feed chiefly on carbohydrates and plant proteids ; the animal feeder, on the 
 other hand, gets a sufficiency of sodium chloride in his food ; and when 
 added to animal food, sodium chloride is more of a condiment than a food. 
 More sodium chloride is necessary to vegetable feeders, because in man. 
 
 ' Zeits. f. Biol. Bd. ii. 1866, p. 459. 
 
FOOD 
 
 407 
 
 potassium salts increase the excretion of sodium cliloride in the urine. In 
 vegetable food there is twice or three times the amount of potassium salts 
 that exists in animal food (see sections on separate foodstuffs). 
 
 Influence of Constitution and Work on Diet. — It has been stated that there 
 are great individual differences in the diets, due chiefly to the different physio- 
 logical conditions of men and to the different surrounding conditions. The 
 chief difference between the diets of men, however, is duo to the amount of 
 mechanical labour they perform. The greater the work done, the larger 
 the amount of food necessary, and in the diet (see table) the proteids and 
 fats are chiefly increased. Although work does not increase the excretion of 
 nitrogen, as has been shown by the experiments of Fick and Wislicenus and 
 others, yet by work the living nitrogenous muscle is made physiologically 
 active : this leads to partially using up the muscle substance, which has 
 to be replaced by the taking in of nitrogenous food. Moreover, the increase 
 of proteids in the diet is necessary for the hypertrophy of the muscles which 
 occurs during prolonged efforts. 
 
 The influence of sex on diet rests chiefly on the greater manual work that 
 men do ; the woman's diet being | to -^ that of the man's. An increased 
 amount of food is taken by the woman during lactation, and probably during 
 gestation also. 
 
 Climate influences diet to some extent. Thus in cold countries the fat 
 of the diet is increased. Great stress has been laid on the fact that some 
 of the nationalities in India subsist chiefly on carbohydrate food and do 
 great work on it. Carbohydrates, however, do not form a large part of the 
 diet if animal food can be procured ; so that its extensive use is due more to 
 economical necessities than to its being advantageous. 
 
 Influence of Age. — Diet varies in childhood and in old age from that which 
 we have discussed as essential to health in adult life. During childhood, 
 from birth to puberty, the organism is growing, tissues are developing, 
 especially the nervous, muscular, and bony tissues ; food has to be supplied 
 for the growth of these tissues, as well as to maintain the nitrogen- 
 equilibrium of the body. In old age less food is required than in adult 
 life, owing to the diminished metabolism of the body and the cessation of 
 mechanical labour. In old age there is diminished excretion of carbonic acid. 
 
 Childhood. — During the first six months of life, the child grows rapidly. 
 According to Vierordt, during this time it gains from 120 to 300 grammes (4*5 
 to 10"5 ounces) per week ; during the second six months the gain is less, 
 being 100 to 200 grammes weekly ; while during the second year it is 50 to 100 
 grammes a week.^ The rapidity of gain of weight then diminishes up to 
 puberty. . 
 
 The following table ^ shows the minimum daily need of foodstuffs at 
 different ages : — 
 
 Coudition 
 
 WeigM in grammes 
 
 Proteid 
 
 Pat 
 
 Carbohydrates 
 
 Child up to Ih year (average) 
 ,, from 6-15 years (average) . 
 
 Man (moderate work) 
 
 Woman (moderate work) .... 
 
 Old man 
 
 Old woman 
 
 20-36 
 70-80 
 118 
 
 92 
 100 
 
 80 
 
 30-45 
 37-50 
 
 56 
 
 44 
 
 68 
 
 60 
 
 60-90 
 250-400 
 500 
 400 
 350 
 260 
 
 Physiologie des Xindesalters. Tubingen, 1877. 
 
 Konig, Procent.-Zusammensetzung der menschl. Nahrungs-Mittel, &c. Berlin, 1888. 
 
408 
 
 HYGIENE 
 
 The carbohydrate and fat in the diet of the child is proportional to the 
 carbonic acid excreted. Of mineral foods, besides sodium chloride calcium 
 and magnesium salts and phosphates are most essential to the child. About 
 5 per cent, of the food is undigested in children. 
 
 The diet of children varies with rapidity of growth, and also in different 
 individuals. The daily minimum necessary for growing children is as 
 follows : — 
 
 Of proteid . . 2-3 to 3-0 grammes pur kilogramme of body-weight ; 
 
 Of fat . . 2-1 to 2-6 
 
 Of carbohydrate 9-5 to 12-3 „ 
 
 Meat, milk (milk products), bread, and flour make up the diet of children, 
 peas, potatoes, and other vegetables being adjuncts only. One litre of milk 
 (35 ounces) contains half the proteids required by the child daily — i.e. about 
 38 grammes (see p. 429). Up to the fourth year of age milk forms practically 
 half the diet of the child ; from that age to the eleventh year it forms about 
 one-third (Camerer). From the fourth year, also, the vegetable food is in- 
 creased in the diet. 
 
 A complete daily diet for children of six to seventeen years is as follows : ^ 
 
 Article of food 
 
 Weight in 
 
 Proteids 
 
 Fat 
 
 Carbohydi-ates 
 
 Meat (raw) 
 
 Bread .... 
 Potatoes .... 
 Fat (butter and lard) 
 
 Milk 
 
 Flour (for soup) 
 Vegetables (various) . 
 
 Total . 
 
 Grammes 
 170 
 300 
 180 
 15 
 250 
 100 
 180 
 
 Oz. avoir. 
 
 6-0 
 10-5 
 6-3 
 0-5 
 8-8 
 3-5 
 6-3 
 
 Grammes 
 300 
 19-5 
 3-0 
 
 8-5 
 
 100 
 
 7-0 
 
 Granmies 
 17-0 
 1-0 
 0-3 
 140 
 90 
 10 
 10 
 
 Grammes 
 
 150 
 36 
 
 12 
 
 74 
 
 9 
 
 1,195 
 
 41-9 
 
 78-0 
 
 43-3 
 
 281 
 
 To such a diet must be added food-accessories, such as coffee, tea, chocolate, 
 and flavouring materials. 
 
 The diet of old age, which is given on p. 407, is important for considera- 
 tion in public institutions, almshouses, &c., where the aged poor are eared for. 
 The figures given above represent the minimum diet ; but in many institutions 
 less food is taken. Thus Forster found in an almshouse that each man re- 
 ceived daily 91*5 grammes of proteid, 45'2 grammesof fat, and 331 "6 grammes 
 of carbohydrates, part of the food consisting of 171 grammes of meat (without 
 bone) and 282 grammes of bread ; each woman received 79*1 grammes of 
 proteids, 48*6 grammes of fat, and 265"1 grammes of carbohydrates, partly 
 contained in 94 grammes of meat (without bone) and 259 grammes of bread, 
 with cheese. 
 
 The Proportion of Nitrogenous to Non-nitrogenous Foodstuffs in a Diet. — 
 The amount of proteid daily necessary for the organism is a more or less 
 constant quantity ; as we have seen, a certain minimum must be ingested to 
 feed the nitrogenous tissues, to maintain the N-equilibrium, and to carry out 
 the other functions of proteid food which have been already indicated. As 
 we have seen, also, the functions performed by the non -nitrogenous organic 
 foodstuffs— fats and carbohydrates — in the organism are more or less similar, 
 though there are reasons why both forms should be included in a diet. We 
 have now to consider the proportion between the nitrogenous and non- 
 nitrogenous foodstuffs in different diets, and also between fats and carbo- 
 ' Konig, Zusammensetzimtj der menschl. Nahrungs-Mittel, Bd. i. 1889, p. 149. 
 
FOOD 
 
 409 
 
 hydrates ; in other words, with regard to the latter question, what proportion 
 between fats and carbohydrates is the most advantageous in a diet. 
 
 From numerous experiments, it has been concluded that the proportion 
 between the nitrogenous and non-nitrogenous organic foodstuffs in a diet 
 ought to be as 1 to 3'5 or 4*5 ; this is the average. Thus, in Moleschott's diet, 
 the proteids (130 grammes) are to the non-nitrogenous (fats, 84 grammes 
 + carbohydrates 404) as 130 : 488, or 1 : 3-9. And this relation is preserved, 
 not only in the diets of adults in moderate work, but in the diet of laborious 
 work, in that of childhood, and in that of old age. 
 
 Taking Pettenkofer and Voit's conclusion that 100 grammes of fat is iso- 
 dynamic with 175 grammes of carbohydrate (p. 403), we may express the non- 
 nitrogenous organic foodstuffs of a diet in terms either of fat or of carbohydrate. 
 Thus, taking Moleschott's diet, containing 84 grammes of fat and 404 grammes 
 of carbohydrate daily, the non -nitrogenous foodstuffs would be expressed — 
 
 a. In the form of Fat 
 
 84 grammes of fat 
 
 404 grammes of carbohydrate, equal to (175 = 100) , 
 
 fc. In the form of Carbohydrate 
 84 grammes of fat, equal to (100 = 175) . 
 404 grammes of carbohydrate . r . • 
 
 84 
 231 
 
 315 grammes 
 
 147 
 404 
 
 551 grammes 
 
 In one case, therefore, the non-nitrogenous foodstuffs would be taken in 
 the form of 315 grammes fat ; in the other of 561 grammes carbohydrate. 
 We shall see reasons why neither of these modes of taking non-nitrogenous 
 food is advantageous. In the following table' the proportion of fat to 
 carbohydrates is given for diets under different conditions. 
 
 Fat in the diet of is as 1 to 
 
 
 Child at breast .... 
 
 1-4 
 
 carbohydrate 
 
 Child five months old . 
 
 1-4 
 
 
 Workman's child 
 
 5-6 
 
 
 Adult (in easy circumstances) 
 
 3-4 
 
 
 Adult workman .... 
 
 5-0 
 
 
 Old man 
 
 51 
 
 
 Old woman 
 
 5-3 
 
 
 Nursing woman .... 
 
 2-4 
 
 
 According to Voit,^ the proportion of fat to carbohydrates in the daily diet 
 ought not to be less than 1 to 9, which would mean 56 grammes of fat and 
 500 grammes of carbohydrates. Increase of carbohydrate above this amount 
 is disadvantageous to the organism. We have seen that fat is increased in 
 the diet when laborious work is performed, and in very cold cUmates, its 
 great potential energy being of service to the organism.^ Carbohydrates are 
 increased in a diet out of the standard proportion to fat in the food of the 
 poor, because they are cheaper, the chief part of the fat of food being derived 
 from animal food, which is dearer than vegetable. As wages improve, how- 
 ever, the carbohydrates are diminished and more animal food and fat are taken. 
 
 For the effects of an excess of fat and of carbohydrates on digestion, see 
 Digestibility of Food (p. 420). 
 
 1 Forster, art. ' Ernahrung,' Ziemssen's Handbuch, p. 137. 
 
 * Quoted by Forster, loc. cit. 
 
 * Potential energy of one gramme of fat = 9,070 calories (Frankland) ; of one gramme of 
 grape-sugar, 3,939 calories (Von Eeichenberg). 
 
410 HYGIENE 
 
 Construction of Diets with Articles of Food 
 The particular dietary of a race is the result of ancient traditional rules, 
 
 purely empirical ; these rules naturally alter with the varying surrounding 
 
 conditions and modes of life of the people. It would be out of place here to 
 
 deal with the various diets of different races ; only the diet of civihsed peoples 
 
 will be discussed. 
 
 The construction of a dietary and the examination of a given diet are of 
 
 importance, not so much to the well-to-do, but to soldiers, sailors, and other 
 
 collections of indi\-iduals who are fed en masse. 
 
 It will be well to recapitulate the several points to which attention must 
 
 be directed in regard to food : — 
 
 1. The necessary daily quantity of foodstuffs has already been discussed. 
 It varies with childhood, adult hfe, and old age, and with the amount of 
 mechanical labour performed. The last point is important, and it necessitates 
 an increase in the organic constituents of the diet. 
 
 2. Even though the daily necessary amount of foodstuffs may be ingested 
 the body may suffer, and this is due to several causes : — 
 
 (a) Conditions of digestibility ; the food being rendered indigestible by 
 being taken in too great bulk, or by containing a large amount of cellulose, 
 or by being too acid, or by being badly cooked. 
 
 (b) The flavouring may be deficient or of too uniform a character. In 
 large institutions the condition of the inmates is materially improved in 
 some cases by attending to this point. 
 
 (c) If one food is continued for too long a time, it is finally refused or not 
 eaten with relish. 
 
 No mere calculation, therefore, of the amount of foodstuffs can gauge the 
 efficacy of a particular diet. The other conditions just mentioned must be 
 also considered. 
 
 Milk has been considered by some as the type of a perfect food. It 
 contains 4 per cent, (by weight) of proteid, in the form chiefly of casein, 
 but also as albumin in very small quantity ; ' 3'7 per cent, of fat (butter) ; 
 4-8 per cent, of carbohydrates in the form of lactose ; and 0"7 per cent, of 
 salts, with 8G-8 per cent, of water. The proportion between the proteids and 
 the non-nitrogenous organic foodstuff is as 1 to 2-125, and the proportion of 
 fat to carbohydrates is as 1 to 1*4. In cow's milk, therefore, the proportion 
 of nitrogenous to non-nitrogenous foodstuffs does not reach the normal, 
 which is 1 to 3-5 or 4-5. Cow's milk is therefore not a perfect food for man. 
 In human milk, however, which contains less proteids than cow's milk, but 
 more carbohydrates, this ratio is as 1 to 4. Human milk is therefore more 
 suited to the child than cow's milk, and the latter is brought up to the 
 standard of human milk by removing some of the casein, by diluting with 
 water and adding carbohydrates, such as sugar (see Milk, p. 428). 
 
 The salts of milk consist mainly of sodium chloride, and potassium and 
 calcium phosphates. Calcium phosphate, which is so important to the child, 
 is taken in greater quantity (four to five times) in the day than is stored up. 
 During the lactating period about 5*5 grammes of calcium phosphate is stored 
 up each week, which is equivalent to an increase of weight of one kilo- 
 gramme in the first year (Forster). Although milk is both scientifically and 
 practically the proper food for children (cow's milk to a less extent than 
 human milk), for adults it is not so suitable, chiefly because the great quantity 
 of water taken with the food is prejudicial to the healthy digestion of adults. 
 
 ' What has been described as ' lacto-protein ' and ' other proteids ' are probably not 
 normally present in milk ; they are due to decomposit on of the casein and albumin. 
 
FOOD 
 
 411 
 
 o o 
 
 tig 
 
 o hi) 
 P* o 
 
 In adults the diet 
 is mainly composed 
 of meat of varying 
 degrees of fatness, 
 butter, bread, and ^ ^ 
 potatoes ; these must 
 be considered as the chief 
 articles of diet, although in 
 some countries rice and 
 maize take the place of 
 bread and potatoes as 
 carbohydrate food. 
 
 The annexed diagram, 
 taken from Konig, shows 
 the proportion of food- 
 stuffs in these articles of 
 diet : — 
 
 A glance at the dia- 
 gram will show that in 
 none of the articles of diet, 
 with the exception of milk, 
 is the proportion between 
 the nitrogenous and non- 
 nitrogenous foodstuffs as 
 1 to 3-5-4-5. In beef the 
 proportion is about 4 to 1 ; 
 in eggs, about 1 to 1 ; in 
 bread, 1 to 8 ; m potatoes, 
 1 to 10 ; in peas, 1 to 2-3. 
 In peas, therefore, the pro- 
 portion approaches the 
 normal. A single food 
 is, therefore, on these 
 grounds alone, not of the 
 composition requisite to 
 supply the daily need of 
 foodstuffs. If beef, e.g., 
 formed the sole article of 
 diet, an excessive quantity 
 would have to be taken 
 to procure the daily need 
 of non-nitrogenous food. 
 In the same way, if 
 vegetable food (with the 
 exception of peas and 
 beans) formed the chief 
 article of diet, a very large 
 quantity would be neces- 
 sary to obtain the requisite 
 amount of proteid. 
 
 This is shown in the 
 following table, in which, 
 Moleschott's diet being 
 taken as the standard, the 
 
 1^ 
 
 ■ 
 
 ^^:;> 
 
 m 
 1 
 
 iۤ 
 
 g 
 
 
 m 
 
 
 i 
 
 i 
 
 
 ^ufi 
 
 V) 
 
 N 
 
 < 
 111 
 
 < 
 
 0. 
 
 Z 
 
 n -s 
 
 5 -3 
 
 iu S 
 
 b 
 
412 
 
 HYGIENE 
 
 quantities of foods are given containing the daily need of the different food- 
 stuffs : — 
 
 MolescJioWs Daily Diet : Protcids 130 grammes (4-59 oz.). Fats 84 grammes (2-96 oz.), 
 Carbohydrates 404 grammes (14-26 02.) 
 
 
 
 
 To obtniu 
 
 Food 
 
 
 
 
 
 
 130 gi-ammes proteids 
 
 84 prammes fat 
 
 404 grammes 
 
 
 
 
 aru rt'iiuisite 
 
 carbohydrates 
 
 
 Gr. 
 
 Oz. avoir. 
 
 Cr. 
 
 Oz. avoir. 
 
 Gr. 
 
 Oz. avoir. 
 
 Of beef 
 
 604 
 
 21-3 
 
 1,527 
 
 53-8 
 
 — 
 
 . — 
 
 Of eggs. 
 
 
 
 946 
 
 33-3 
 
 700 
 
 24-6 
 
 . — 
 
 — 
 
 Of milk 
 
 
 
 3,250 
 
 5pt.l4oz. 
 
 2,270 
 
 4 pts. 
 
 — 
 
 — 
 
 Of cheese 
 
 
 
 388 
 
 13-3 
 
 345 
 
 120 
 
 . — 
 
 — 
 
 Of fat of meat 
 
 
 
 1,487 
 
 52-3 
 
 112 
 
 3-9 
 
 — 
 
 — 
 
 Of butter . 
 
 
 
 
 
 — 
 
 95 
 
 3-3 
 
 — 
 
 — 
 
 Of lard . 
 
 
 
 
 
 — 
 
 84 
 
 2-96 
 
 — 
 
 — 
 
 Of peas 
 
 
 
 565 
 
 20-0 
 
 — 
 
 — 
 
 777 
 
 27-4 
 
 Of maize 
 
 
 
 1,300 
 
 45-8 
 
 1,254 
 
 44-2 
 
 626 
 
 22-0 
 
 Of rice . 
 
 
 
 1,625 
 
 57-3 
 
 — 
 
 — 
 
 521 
 
 18-3 
 
 Of wheaten bread (fine) 
 
 
 1,857 
 
 65-5 
 
 — 
 
 — 
 
 732 
 
 25-8 
 
 Of potatoes . 
 
 
 0,500 
 
 229-2 
 
 — 
 
 — 
 
 1.951 
 
 65-9 
 
 The nutritive value of the food articles will be discussed under the head- 
 ing of each. It is necessary, however, here to point out the most advan- 
 tageous way in which these food articles can be combined in a diet. For 
 this purpose we may divide articles of food into animal and vegetable, the 
 animal foods supplying the chief part of the proteids and the fat almost 
 exclusively, the vegetable supplying the carbohydrates and a small part of 
 the proteids, while the salts come from both classes of food, some vegetables 
 (the succulent especially) being taken chiefly for the salts they contain. 
 
 In translating the elements of a diet into terms of food articles, it is 
 essential to remember (1) the effects on the food of cooking in the way of 
 gain or loss (especially of salts), and of physical and chemical changes in the 
 foodstuffs (see p. 421) ; (2) also that in children about 5 per cent, of the food 
 consumed is undigested, and in adults about 10 per cent. 
 
 Supposing a simple diet, Moleschott's figures can be expressed approxi- 
 mately in the following table : — 
 
 Article of food 
 
 Weight in 
 gi-ammes 
 
 Weight 
 in oz. 
 
 Proteids 
 
 Fat 
 
 Carbo- 
 hydrates 
 
 Salts 
 
 Water 
 
 Meat . 
 Butter . 
 Milk . 
 Bread . 
 Cabbage 
 Potatoes 
 Sugar . 
 
 
 385 
 70 
 
 500 
 
 225 
 
 250 
 
 70 
 
 13-5 
 2-4 
 
 17-6 
 7-9 
 
 8-8 
 2-4 
 
 82-8 
 2-3 
 
 35-0 
 4-5 
 5-0 
 
 21-0 
 62-0 
 
 2-5 
 
 276-0 
 11-25 
 51-75 
 67-4 
 
 3-85 
 1-89 
 
 5-6 
 2-25 
 2-5 
 3-5 
 
 279-0 
 4-0 
 
 180-0 
 202-25 
 170-0 
 2-0 
 
 Total . 
 
 
 1,500 
 
 52-6 
 
 129-6 
 
 85-5 
 
 406-4 
 
 20-59 
 
 837-25 
 
 The total weight of food then would be about 1,500 grammes, to which 
 must be added 150 grammes in calculating a diet, as 10 per cent, is undigested, 
 making the total 1,650 grammes. 
 
 In this calculated diet, milk and fliour may be with advantage used : 
 500 cc. of milk and 200 cc. of flour would replace 20 grammes of the butter, 
 120 grammes of the potatoes, and 220 grammes of the bread. 
 
 A diet with an excess of vegetable food or consisting solely of vegetable 
 food produces copious soft fteces, containing a large quantity of water; 
 
FOOD 
 
 413 
 
 animal food produces scanty and tenacious faeces. Comparing a mixed diet 
 with a vegetable diet, Schiister found that the fsBces in the latter were (when 
 dried) more than double that in the former, while a large amount of proteid 
 of the vegetable diet was unabsorbed (quoted by Forster). Thus : 
 
 - 
 
 Proteids 
 In food 1 Absorbed 
 
 In dried 
 faeces 
 
 Prisoner, vegetable diet 
 
 Experimental prisoner on mixed diet of bread, vegetables, 
 milk, and meat ...,..., 
 
 104 
 
 87 
 
 78 
 70 
 
 70 
 30 
 
 This would agree with the fact that a large admixture of indigestible 
 matter (cellulose) with the food diminishes the absorption of the digestible 
 foodstuffs — a point to be considered more fully afterwards (see Bread). 
 
 Another result of the excessive or exclusive ingestion of some forms of 
 vegetable food is the amount of gas formed in the intestines, as well as the 
 large amount of undigested matter. ' 
 
 The poor classes use in their diet a larger proportion of carbohydrates 
 than the well-to-do, the excess of carbohydrates taking the place of part of 
 the fat, which is more expensive. With the labourers inLombardy, Bavaria, 
 and Saxony the carbohydrates vary from 800 to 1,200 grammes in the daily 
 diet, while the proteids are from 140 to 180 grammes.^ An ordinary labourer 
 will, however, use much less carbohydrates (450 grammes), while the better 
 classes use still less (325 grammes). 
 
 Forster ® gives the following comparison between part of the daily food 
 of a young doctor and a workman : — 
 
 
 Fresh 
 meat 
 
 Bread 
 
 Beer 
 
 Pro 
 In form of 
 meat 
 
 teids 
 In form of 
 bread 
 
 Carbo- 
 hydrates in 
 bread 
 
 Carbo- 
 
 hydi-ates in 
 
 beer 
 
 Workman 
 Young doctor 
 
 G-r. 
 161 
 385 
 
 Or. 
 412 
 150 
 
 Co. 
 1,500 
 1,625 
 
 Gr. 
 
 35-5 
 
 84-8 
 
 Gr. 
 44-3 
 24-8 
 
 Gr. 
 287-3 
 
 86-4 
 
 Gr. 
 78-0 
 84-5 
 
 That is, the workman takes 27 per cent, of his proteids in the form of 
 meat, the young doctor 65 per cent. 
 
 The diet of the doctor was richer in fat, and the proportion of fat to 
 carbohydrates in his diet was that of 1 : 3*5 in the workman, on the other 
 hand 1 : 5-8. 
 
 The total daily amount of food in the two diets may be thus compared : 
 
 - 
 
 Proteids 
 
 Fat 
 
 Carbohydrates 
 
 Water 
 
 Proportion of nitrogen 
 ous to non-nitrogenous 
 
 Workman 
 Yomig doctor . 
 
 132 
 131 
 
 81 
 95 
 
 458 
 332 
 
 2,916 
 2,975 
 
 1 : 5-0 
 1 :4-3 
 
 Special Diets 
 
 The study and correct understanding of diet are important to those able 
 to command every variety of food, but they are of vital importance to com- 
 munities and bodies of individuals which are supported by the State or in 
 
 * See Kutgers, Zeits. f. Biologic, Bd. xxiv. 1887, p. 351. 
 
 ^ Quoted by Forster, op. cit. p. 125. 
 
 ' Op. cit. Also Zeits. f. Biologic, 1873, p. 351. 
 
114 
 
 HYGIENE 
 
 public institutions. The diet of tlie soldier and the sailor in peace and war, 
 of the working classes, of prisoners, of those in almshouses, workhouses, 
 and schools, and, lastly, the diet of patients in hospitals, have in this respect 
 to be considered. The diet of the sick is a special subject, and will not be 
 treated here : it is a part of medical treatment. 
 
 In considering the diet of such communities of individuals as have been 
 enumerated, not only must the food contain the proper proportion of food- 
 stufi's, such as we have been considering, but the food must be obtainable at 
 a certain price, the object being to provide the most nutritious food at the 
 lowest possible cost. And it is evident that in the case of soldiers, sailors, 
 and the working classes, who are called upon either continuously or at 
 intervals to perform hard work, the question of the energy obtainable by 
 the body from the food supphed is of prime importance. In such classes of 
 men, too, the question of stimulants has to be considered — stimulants to the 
 nervous system, such as tea, coffee, beef-tea, and alcoholic drinks. This last 
 subject will be dealt with under Food-accessoeies ; at present we are only 
 concerned with the daily amount of food required to preserve the health of 
 communities of men. 
 
 Soldiers' and Sailors' Bations 
 
 According to Parkes ^ the usual food of the soldier may be expressed as 
 follows : — 
 
 Articles 
 
 Daily quan- 
 tity in oz. av. 
 
 Water 
 
 Proteids 
 
 Fats 
 
 Carbo- 
 hydrates 
 
 Salts 
 
 Total water 
 per food 
 
 Meat 
 
 Bread . 
 
 Potatoes 
 
 Other vegetables 
 
 Milk . 
 
 Sugar . 
 
 Salt 
 
 Coffee . 
 
 Tea 
 
 
 12 (1 bone) 
 240 
 160 
 80 
 3-25 
 1-33 
 0-25 
 0-33 
 0-16 
 
 7-20 
 9-60 
 11-84 
 7-28 
 004 
 
 1-44 
 1-92 
 0-32 
 0-14 
 0-13 
 
 0-81 
 0-36 
 002 
 0-04 
 012 
 
 11-81 
 3-36 
 0-46 
 0-16 
 1-29 
 
 0-15 
 0-31 
 0-02 
 0-06 
 002 
 
 0-25 
 
 2-40 
 14-40 
 3-72 
 0-70 
 0-43 
 1-29 
 0-25 
 
 Total 
 
 
 65-32 
 
 37-78 
 
 3-95 
 
 1-35 
 
 17-08 
 
 0-81 
 
 23-19 
 
 This dietary contains 276 grains of nitrogen and 4,588 grains of carbon. 
 It consists of 112 grammes of proteid, 38*3 grammes of fat, 485 grammes 
 of carbohydrates, and 23 grammes of salts ; and the proportion of nitro- 
 genous to non-nitrogenous foodstuffs is as 1 : 4*6. 
 
 The diet is, however, deficient in proteids, and especially in fat, the pro- 
 portion of fat to carbohydrate being 1 : 12. This is too small a proportion 
 (see p. 409) ; so that the diet would be much improved by adding butter or 
 cheese to it. A larger quantity of proteids would also be obtained by substi- 
 tuting peas and beans for the less nutritious vegetables, such as cabbage 
 (returned in the table as ' other vegetables '). Vinegar is also with advantage 
 added to the food. 
 
 The mean of the observations of Voit, Artmann, Hildesheim, and Play- 
 fair of the soldier's daily diet during peace is 114 grammes of proteids, 45 
 grammes of fat, and 486 grammes of carbohydrates ; a diet closely resembling 
 that of the English soldier. In war the diet would be 138 grammes of pro- 
 teids, 72 grammes of fat, and 497 grammes of carbohydrates ; proportion of 
 
 Pract. Hygiene, p. 516. 
 
FOOD 
 
 415 
 
 nitrogenous to unnitrogenous foodstuffs being 1 : 4'9 (mean of Hildeslieim, 
 Artmann, and Playfair's calculations).^ 
 
 When there is hard work to be done, as in the field or in forced marches, 
 it is advantageous to increase the fat of the diet, and to increase the food- 
 accessories. The increase of fat enables more work to be done, and the 
 food-accessories (tea, coffee, beef-tea, &c.) act serviceably as stimulants to 
 the nervous system. 
 
 In the Franco-Prussian war (1870-71) the German soldier had daily : ^ 
 
 - 
 
 Protciil 
 
 Fat 
 
 Carbohydrate 
 
 Bread, 750 grammes 
 
 Meat, 500 grammes 
 
 Bacon fat, 250 grammes 
 
 1 litre of beer .... 
 
 Total . . . 
 
 48 
 100 
 
 11 
 
 5 
 
 4 
 
 15 
 
 190 
 
 345 
 
 55 
 
 164 
 
 209 
 
 400 
 
 Each man had also 30 grammes of coffee and 60 grammes of tobacco. 
 Such a diet, rich in fat, is only for the most strenuous exertion. 
 
 Diet of the Working Glasses 
 
 The working classes have to arrange their diet according to the wages 
 they earn, and there is but little doubt that teaching them how to obtain 
 the most nutritious food at the cheapest possible price is one of the great 
 aims of hygiene. A proper dietary for the working classes would mean the 
 improved health of the larger portion of the community, since deficient food 
 itself causes disease and exposes an individual to the dangers of infectious 
 diseases. 
 
 In the dietary of the working classes in all parts of Europe there is a 
 deficiency of proteid and of fat and an excess of carbohydrates. The 
 deficiency of proteid in the diet is due to the fact that but little animal food 
 is eaten ; fat is deficient from the same cause. 
 
 Voit gives in the diet of a workman and workwoman with moderate work 
 the following minimum as the daily need (see also p. 407). 
 
 — 1 Total proteid 
 
 Digestible proteid 
 
 Fat 
 
 Carbohydrate 
 
 Man . , 
 "Woman . 
 
 Grammes 
 
 118 
 
 94 
 
 Grammes 
 
 106 
 
 84 
 
 Grammes 
 54 
 49 
 
 Grammes 
 500 
 400 
 
 The woman's diet may be reckoned as from three-quarters to four-fifths 
 of the man's. 
 
 The actual diets used by the various classes of working men and women 
 differ considerably from Voit's figures ; as seen in the following table, taken 
 from C. A. Meinert,^ the daily food taken is greatly deficient in proteids and 
 fats, a point which has been already mentioned. Although in tliis table the 
 diets investigated are those of the working class in Germany, almost precisely 
 similar results are obtained from the diet of the Enghsh working class. 
 
 ' Konig, Zusavimensetz. der menschlich. Nalirungs- u. Genussmittel, 1889, ii. 156. 
 also C. A. Meinert, Armee- u. Volks-Erncihrung, Berlin, 1880, i. 286. 
 - Konig, op. cit. p. 160. 
 * Op. cit. ii. 171-260. 
 
 Sea 
 
416 
 
 HYGIENE 
 
 
 Total amt. 
 
 Total 
 
 Digestible 
 
 
 Carbo- 
 
 
 
 
 of food 
 
 protcid 
 
 proteid 
 
 
 hydrate 
 
 
 Kind of food 
 
 
 Grammes 
 
 Gr. 
 
 Grammes 
 
 Gr. 
 
 Gramnip;; 
 
 rence 
 
 
 Poor woikman . 
 
 — 
 
 86-0 
 
 — 
 
 130 
 
 GlO-0 
 
 — 
 
 Potatoes 
 
 Uerlin workman, ob- 
 
 
 
 
 
 
 
 
 taining foodchiefh' 
 
 
 
 
 
 
 
 
 from People's Kit- 
 
 
 
 
 
 
 
 
 chens . 
 
 — 
 
 — 
 
 C80 
 
 37-0 
 
 2900 
 
 — 
 
 Chiefly vege- 
 
 Seamstress or book- 
 
 
 
 
 
 
 
 table food 
 
 binder (female) 
 
 846 
 
 OO'O 
 
 47-4 
 
 51-4 
 
 229-2 
 
 41- 
 
 Little meat 
 
 Painter iii Leipzig . 
 
 1,199 
 
 86-7 
 
 73-3 
 
 68-6 
 
 366-2 
 
 5} 
 
 Mixed food 
 
 Cabinet-maker .• 
 
 1,281 
 
 70-5 
 
 60-5 
 
 57-2 
 
 465-8 
 
 5,V 
 
 »» 
 
 All these diets are those of poor workpeople. 
 
 The question as to the means by which the poor and the working clasa 
 can obtain the best food at the lowest price is an important one, but too wide 
 to deal with fully here. 0. A. Meinert has treated the subject in a pamphlet 
 entitled ' ^Yie niihrt man sich gut und billig ? ' ' Some of his conclusions 
 may be given here. A family is reckoned as consisting of a man, wife, and two 
 children of ten to twelve years of age, all of whom together consume the food 
 of three men. In families earning 15s. 6d. to 21s. a week 60 per cent, of the 
 income may be spent on food — that is, from 9s. Gd. to 12s. 6d. a week. In 
 those earning 29s. a week half may be spent on food — that is, 14s. Gd. weekly. 
 For the table showing how the working man can obtain the best food for this 
 money Meinert's pamphlet must be consulted.- He reckons that the two 
 poorer families can obtain 100 grammes of proteid, 50 grammes of fat, and 
 500 grammes of carbohydrate daily ; while the family better off can obtain 
 120 grammes of proteid, 70 grammes of fat, and 500 grammes of carbohy- 
 drate — a diet more closely resembling the normal than the first. In the first 
 diet the proportion of nitrogenous to non-nitrogenous foodstuff is as 1 : 5-5, 
 of fat to carbohydrate as 1 : 10 ; in the second diet the proportions are as 
 1 : 4*7 and 1 : 7. Fat in a cheap form, such as is now sold as ' margarine,' 
 is a very important addition to the working man's diet. 
 
 Diet in Prisons and Workhouses 
 
 A proper diet in prisons is one of the great preventives of a large mor- 
 tality. Besides the evil effects of bad housing, prisoners are especially liable 
 to diseases arising from food. The occurrence of scurvy has by some been 
 ascribed to the deficiency of animal fat in the food.^ This is perhaps 
 doubtful ; but what the diet of prisoners lacks chiefly is animal proteid and 
 fat. The diet is chiefly vegetable, and this may lead to all the trouble 
 which an almost exclusively vegetable (carbohydrate) diet causes. The un- 
 palatable mode of preparation of the food is also a great drawback in the food 
 of prisoners. 
 
 In Prussian prisons since 1872, 210 grammes (about 7oz.) of meat are 
 given weekly; in Belgian, 400 grammes (about 14 oz.) ; in Pentonville, 117 
 grammes (4 oz.) are given daily ; and in Portland, with hard labour, 175- 
 grammes (6 oz.) is the daily allowance."* 
 
 The average amount of foodstuffs present in the different food articles 
 
 ' Berlin, 1882. E. S. Mittler u. Sohn. 
 
 ^ Abstracted also in Konig, op. cit. i. 165. For England, the amount capable of being 
 spent on food is proportionately less, since the rent is greater on the average than in 
 Germany. 
 
 » Eonig, O]o. cit. p. 171. * Ihid. p. 171. 
 
FOOD 
 
 417 
 
 used may be calculated from Richter's results : ' 108 grammes of proteid, 26 
 grammes of fat, and 551 grammes of carbohydrate ; a diet far behind the 
 minimum diet of a workman with moderate work, which is 118 grammes of 
 proteid, 56 grammes of fat, and 500 grammes of carbohydrate (Voit). 
 
 The diet in orphan asylums and other institutions, where the young are 
 cared for, and that in almshouses, where there are the aged poor, must be 
 regulated on the data given on p. 408.'^ 
 
 Arrangement of the Daily Food in Meals 
 
 But little can be said on this subject here. Although as a rule it is a 
 matter of custom, the meals being taken at the times most convenient to the 
 different classes of society, yet there are a few general considerations which 
 are important. Food is usually taken three or four times daily, the largest 
 meal being taken midday or in the evening. About one-half of the tt)tal 
 
 - 
 
 In 100 parts 
 
 Water 
 
 Proteids 
 
 Fats 
 
 Carbo- 
 hydrates 
 
 Salts 
 
 Cellulose 
 
 Beef, witli little fat (beef 
 
 
 
 
 
 
 
 steak) .... 
 
 76-5 
 
 21-0 
 
 1-5 
 
 — 
 
 1-0 
 
 — 
 
 Beef (medium fat) 
 
 72-5 
 
 21-0 
 
 5-5 
 
 — 
 
 1-0 
 
 — 
 
 Beef (very fat) 
 
 55-5 
 
 170 
 
 26-5 
 
 — 
 
 1-0 
 
 — 
 
 Cooked meat (roast or boiled) 
 
 54-0 
 
 27-6 
 
 15-45 
 
 — 
 
 2-95 
 
 — 
 
 Salt beef (Girardin) 
 
 49-1 
 
 29-6 
 
 0-2 
 
 — 
 
 21-1 
 
 — 
 
 Salt pork (Girardin) 
 
 44-1 
 
 26-1 
 
 7-0 
 
 — 
 
 22-8 
 
 — 
 
 Fat pork (Letheby) 
 
 390 
 
 9-8 
 
 48-9 
 
 — 
 
 2-3 
 
 — 
 
 Dried bacon (Letheby) . 
 
 150 
 
 8-8 
 
 73-3 
 
 — 
 
 2-9 
 
 — 
 
 White fish (Letheby) . 
 
 78-0 
 
 18-1 
 
 2-9 
 
 — 
 
 1-0 
 
 — 
 
 Poultry (Letheby) 
 
 74-0 
 
 21-0 
 
 3-8 
 
 — 
 
 1-2 
 
 — 
 
 Egg (deducting 10 per cent. 
 
 
 
 
 
 
 
 for shell) . . . 
 
 74-5 
 
 12-5 
 
 12-0 
 
 — 
 
 1-0 
 
 — 
 
 Human milk 
 
 87-0 
 
 2-5 
 
 40 
 
 6-0 
 
 0-5 
 
 — 
 
 Cow's milk (sp. gr. 1029 
 
 
 
 
 
 
 
 and over) .... 
 
 87-5 
 
 3-4 
 
 3-6 
 
 4-8 
 
 0-7 
 
 — 1 
 
 Skimmed milk (Letheby) 
 
 88-0 
 
 4-0 
 
 1-8 
 
 5-4 
 
 0-8 
 
 — 
 
 Cream (Letheby) . 
 
 660 
 
 2-7 
 
 26-7 
 
 2-8 
 
 1-8 
 
 — 
 
 Cheese . . . . 
 
 36-8 
 
 33-5 
 
 24-3 
 
 — 
 
 5-4 
 
 — 
 
 Butter 
 
 60 
 
 3-3 
 
 88-0 
 
 — 
 
 2-7 (avera 
 
 ge) — 
 
 Bread (fine white wheaten) . 
 
 36-0 
 
 7-0 
 
 0-5 
 
 55-2 
 
 1-0 
 
 
 Whole-meal bread (Church) 
 
 43-4 
 
 10-4 
 
 0-3 
 
 42-7 
 
 1-5 
 
 1-7 
 
 Wheat flour (average) . 
 
 12-81 
 
 12-06 
 
 1-36 
 
 71-83 
 
 0-96 
 
 0-98 
 
 Whole meal (Atwater) . 
 
 13-0 
 
 11-7 
 
 1-7 
 
 69-9 
 
 1-8 
 
 1-9 
 
 Barley meal .... 
 
 14-83 
 
 11-38 
 
 1-53 
 
 71-22 
 
 0-59 
 
 0-45 
 
 Pearl barley (Church) . 
 
 14-7 
 
 7-3 
 
 1-1 
 
 75-8 
 
 1-0 
 
 — 
 
 Eye (average composition) . 
 
 13-71 
 
 11-57 
 
 2-08 
 
 69-61 
 
 1-44 
 
 1-59 
 
 Eice 
 
 13-0 
 
 8-0 
 
 1-0 
 
 76-5 
 
 1-0 
 
 0-5 
 
 Oatmeal (Letheby) 
 
 150 
 
 12-6 
 
 5-6 
 
 63-0 
 
 3-0 
 
 — 
 
 Maize 
 
 14-21 
 
 9-65 
 
 3-8 
 
 69-55 
 
 1-33 
 
 1-46 
 
 Macarpni . . . . 
 
 13-07 
 
 9-02 
 
 0-3 
 
 76-77 
 
 0-84 
 
 — 
 
 Millet (Konig), cellulose ex- 
 
 
 
 
 
 
 
 cluded . . . . 
 
 12-3 
 
 11-3 
 
 3-6 
 
 67-3 
 
 2-3 
 
 — 
 
 Arrowroot . . . . 
 
 15-4 
 
 0-8 
 
 — 
 
 83-3 
 
 0-27 
 
 — 
 
 Pea flour (dry) 
 
 11-41 
 
 25-2 
 
 201 
 
 57-17 
 
 2-89 
 
 1-32 
 
 Potatoes . . . . 
 
 74-98 
 
 2-08 
 
 0-15 
 
 21-01 
 
 1-09 
 
 0-69 
 
 Carrots (cellulose excluded) . 
 
 85-0 
 
 1-6 
 
 0-25 
 
 8-4 
 
 1-0 
 
 — 
 
 Cabbage . . . . 
 
 91-0 
 
 1-8 
 
 0-5 
 
 5-8 
 
 0-7 
 
 — 
 
 Cane sugar .... 
 
 3-0 
 
 — 
 
 — 
 
 96-5 
 
 0-5 
 
 — 
 
 > Konig, p. 171. For further information see TJeber Massenernahrung, by Baer, Jeserich, 
 and C. A. Meinert, Berlin, 1885. ' Untersuch. der Kost in einigen offentlichen Anstalten.' 
 By C. Voit. Miinchen, 1877. 
 
 2 The food supplied in soup-kitchens and other places for the working classes ia 
 treated in C. Voit's work already quoted. 
 
 VOL. I. E E 
 
418 
 
 HYGIENE 
 
 daily food is taken at the chief meal, and about one-third at the next largest 
 meal, which is supper or luncheon or breakfast according to custom. For 
 further details, see Fiirster's paper in the Zcitschrift fiir Biologie (1873, 
 p. 881). 
 
 The taking of a large meal late in the evening leads to digestive distur- 
 bances, since during sleep the process of digestion is practically in abeyance, 
 and the presence of food in the stomach leads to bacterial fermentation. 
 Physiologically speaking, the proper times for the man who is busy all day 
 to have his chief meals are at breakfast and at dinner early in the evening ; 
 and custom has settled it so. To the working man, however, it is more 
 convenient to have the largest meal in the middle of the day ; this is, owing 
 to his hard work, a necessity to him. 
 
 The table on page 41G shows the proportion of organic and inorganic food- 
 stuffs in many articles of diet.' 
 
 From this table the amount of foodstuff' present in a diet can be estimated, 
 so as to test the efficacy of a given dietary. Allowance must be made for 
 cooking and for digestibility, as has been previously explained. 
 
 Digestibility of Food 
 
 No mere calculation of the amount of nitrogen and carbon or the amount 
 of organic foodstuff's in the diet can determine the nutritive value of a diet. 
 To be of use to the organism the organic foodstuff's must undergo a process 
 of digestion before they are absorbed. With the changes (chiefly patholo- 
 gical) Avhich the digestive juices may undergo and thus aft'ect the absorption 
 of food we are not here concerned. But the mixed food itself may be of such 
 a nature as to interfere with its proper assimilation. There are three points 
 which have to be considered xmder this head. 
 
 1. The digestibility of the different organic foodstuffs obtained from the 
 animal and vegetable worlds. 
 
 2. The bulk and chemical reaction of the food taken ; and the admixture 
 of indigestible matter. 
 
 3. The effect of cooking on the food. 
 
 1. The digestibility of the organic foodstuffs — proteids,fats, carbohydrates. 
 
 The proteids obtained from the animal kingdom are more completely 
 digestible than those obtained from the vegetable ; so animal fat is also more 
 digestible than vegetable. This is shown in the following table, constructed 
 fi'om results obtained by Eubner: — 
 
 Digestibility of Foodstuffs {percentage digested) 
 
 — Meat 
 
 Eggs 
 
 ■Wilk 
 
 Cheese 
 
 Bice 
 
 Potatoes 
 
 Peas 
 
 Wliite 
 bread 
 
 Black 
 bread 
 
 Carrots 
 
 Proteid 
 
 Fat 
 
 Carbohydrates 
 
 97-5 
 80-0 
 
 97 
 95 
 
 92 
 95 
 
 97 
 95 
 
 80 
 99 
 
 75-0 
 92-5 
 
 80 
 95 
 
 78 
 99 
 
 68 
 88 
 
 79-5 
 82-0 
 
 From this table it is seen that the proteids of meat, eggs, milk, and 
 cheese are far more digestible than those of rice, potatoes, peas, white 
 bread, &c. 
 
 The carbohydrates of rice and white bread are the most digestible ; while 
 the fat of milk is more digestible than that of meat. 
 
 There is a difference, too, in the digestibility of the different kinds of flesh. 
 Using artificial gastric juice, Chittenden and Cummins^ have found that fish 
 
 ' Compiled from Parkes and Konig. See also separate sections on food articles. 
 * Avicrican Chem. Journal, No. 6, p. 5. 
 
FOOD 
 
 419 
 
 is more difficult to digest than meat, white flesh more digestible than dark, 
 raw beef more digestible than smoked (as 100 : 95), while the presence of fat 
 increases the difficulty of digestion. Taking the digestibility of ox-fiesh as 
 the standard, 100, veal would be 95, mutton 92, lamb 88, poultry (fowl) 
 84-86, while fish would be about 90 (although there are great individual 
 differences). These results have been obtained by artificial digestion with 
 gastric juice. They are not so valuable as the results of Beaumont's and of 
 Eichet's experiments, which were performed on cases of gastric fistulse in 
 man. Beaumont, moreover, showed that artificial digestion with gastric 
 juice was much longer in duration than digestion in the stomach. In the 
 following table Beaumont's and Eichet's results are given ; they are impor- 
 tant from a dietetic point of view, for although many of the substances 
 
 Table of the Digestibilily of Articles 
 
 of Diet in the Stomach ' 
 
 
 
 Length of time in stomach till digested, 
 
 
 
 absorbed, or discharged 
 
 Food 
 
 Preparation 
 
 
 Beaumont 
 
 Eichet 
 
 Schnapps .... 
 
 
 
 — 
 
 30-40 min. 
 
 Milk 
 
 — 
 
 — ■ 
 
 30 min., 1 hr. 
 
 Bice ..... 
 
 Boiled 
 
 Ihr. 
 
 — 
 
 Peas, with bacon fat . 
 
 — 
 
 — 
 
 1-2 hr. 30 min. 
 
 Baked potatoes . 
 
 — 
 
 — 
 
 1 h., 2 h. 15 m., 2-30-3 h. 
 
 Eggs, whipped . 
 
 Baw 
 
 1 hr. 30 min. 
 
 — 
 
 Barley soup 
 
 Boiled 
 
 1 hr. 30 min. 
 
 — 
 
 Salmon trout . . . 
 
 Boiled 
 
 1 hr. 30 min. 
 
 — 
 
 Flesh 
 
 — 
 
 — 
 
 1 h. 30 m., 2 h. 30 m., 
 4h., 5h. 30 m. 
 
 Sago ..... 
 
 Boiled 
 
 1 hr. 45 min. 
 
 — 
 
 Spinach .... 
 
 — 
 
 — 
 
 1 hr. 45 min., 2 hr., 4 hr. 
 
 Tapioca .... 
 
 Boiled 
 
 2hr. 
 
 — 
 
 Barley. .... 
 
 Boiled 
 
 2hr. 
 
 — 
 
 Milk 
 
 Boiled 
 
 2hr. 
 
 — 
 
 Fresh eggs .... 
 
 Baw 
 
 2hr. 
 
 — 
 
 Cabbage, with vinegar 
 
 Baw 
 
 2 hr. 
 
 — 
 
 Soup, with fat and Joread . 
 
 Boiled 
 
 — 
 
 2hr. 
 
 Bice, with fat . 
 
 — 
 
 — 
 
 2h.,2h.45m.,3h.,3h.l5m. 
 
 Milk 
 
 Unboiled 
 
 2 hr. 15 min. 
 
 — 
 
 Fresh eggs .... 
 
 Boasted 
 
 2 hr. 15 min. 
 
 — 
 
 Ox-liver .... 
 
 Baw 
 
 2 hr. 15 min. 
 
 — 
 
 Gelatine .... 
 
 Boiled 
 
 
 
 Lamb 
 
 Broiled 
 
 
 
 Hash — meat and vegetables 
 Beans ..... 
 
 Warmed 
 Boiled 
 
 >-2hr. oOmin. 
 
 — 
 
 Potatoes .... 
 
 Boiled or roasted 1 1 
 
 
 Cabbage .... 
 
 Boiled 
 
 1 
 
 
 Macaroni and fat 
 
 Boiled 
 
 — 12 hr. 30 min.. 3hr. 45 min.! 
 
 Eggs 
 
 Soft boiled 
 
 \ 
 
 
 Beef steak .... 
 
 — 
 
 
 
 "White bread 
 
 Baked 
 
 
 
 Ham . . . 
 
 Boiled 
 
 I ghi. 
 
 _ 
 
 Lean beef .... 
 
 Boasted 
 
 
 
 Fish 
 
 Boiled 
 
 
 
 Mutton .... 
 
 Broiled or boiled 
 
 ^ 
 
 
 ,, .... 
 
 Boasted 
 
 3 hr. 15 min. 
 
 _- 
 
 Pork 
 
 Boasted 
 
 \ 
 
 
 Poultry .... 
 Veai 
 
 Boasted 
 Boasted 
 
 ■ 4hr. 
 
 — 
 
 Brown bread 
 
 Baked 
 
 
 
 Pork 
 
 Salted 
 
 } 5hr. 
 
 
 Eggs 
 
 Hard boiled 
 
 
 * Beaumont, Experiments and Observations on the Gastric Juice and the Physiology 
 of Digestion, Edin. 1838 (reprint). Bichet, Die Stic Gastrique dies VHomme et les 
 Aniviaux, Paris, 1878. 
 
 £ £ 2 
 
420 HYGIENE 
 
 experimented with contain foodstuffs, such as carbohydrates and fats, which 
 are not digested in the stomach, yet the length of time the food remains in' 
 that organ is important, for the longer it remains after a certain time the 
 less is it acted upon, and the more likely is it to undergo fermentation, and 
 thus to cause digestive disturbances. 
 
 From this table the following conclusions may be drawn : — 
 
 (1) That the flesh of animals remains from two and a half hours to five 
 hours in the stomach, the most digestible being lamb, then, in order, beef 
 steak, lean meat, mutton, veal and pork, while fish is equal to mutton in 
 digestibility. • 
 
 (2) That starchy foods, as rice, barley, and tapioca, do not remain more 
 than two hours in the stomach, while beans, peas, and potatoes remain for 
 two and a half hom-s, white bread for three hours, and brown bread for four 
 hours. 
 
 (3) Eichet's results, however, show that, even for the same substance in 
 the same subject, there are varying times in which it remains in the stomach : 
 thus, baked potatoes remained sometimes one hour, sometimes two and a half- 
 hours, or even three hours. 
 
 The figures quoted, therefore, only give broad differences of digestibility 
 between foods ; digestions differ almost as much as individuals. 
 
 The effect of cooking on meat is, that the more tough the process makes 
 the meat, the more indigestible it is. Honigsberg, comparing the amount of 
 peptone formed by artificial gastric juice from boiled beef and roasted beef, 
 found that in the digested material the proportion of peptone to other nitro- 
 genous substance in boiled meat was as 1 : 2*75, while in roasted beef it 
 was 1 : 1*03 ; from roasted meat, therefore, more peptone is formed than 
 from boiled, raw meat being intermediate in digestibility ' (see Effect of 
 Cooking). 
 
 2. Btdk and Beaction of Food. — The division of the daily food into meals 
 has been previously discussed. If too large an amount of the daily food be 
 taken at one meal, the result is not advantageous to the organism. The 
 excess of food throws extra work on the stomach, and continued will end 
 in imperfect digestion and assimilation, with the liability of fermentation of 
 the ingesta, butyric, lactic, acetic, and other fatty acids being formed in 
 excess. This fermentation is especially hable to occur when an excess of 
 vegetable (carbohydrate) food is taken. Not only do the carbohydrates 
 readily spht up under the action of bacteria into the different fatty acids, but 
 most vegetable food contains the so-called vegetable acids, acetic, tartaric, 
 citric, &c., either free or in the form of salts, and these simply add fuel to the 
 fire in the stomach. Fats, also, both when neutral and when containing fatty 
 acids, may aid in increasing the acidity of the stomach's contents (due to 
 organic acids), and thus diminish the absorption of foods taken into the 
 digestive tract. Even if this fermentation does not occur, in some cases the 
 food ingested is imperfectly assimilated owing to its admixture with indi- 
 gestible matter — e.g. cellulose. This result, therefore, occurs when vegetable 
 food is chiefly taken. Thus, with a diet of meat alone, no muscle fibres are 
 found in the faeces, but they are observed when food containing much cellu- 
 lose is taken with the meat.- With brown bread, also, S. Meyer found that 
 20 per cent, (dried) was passed out of the body, while with white bread only 
 6 per cent.^ Kubner has also shown that with the daily use of 960 grammes 
 
 > Wiener vied. Blatter, 1882, p. 582. 
 
 '^ Forster, art. ' Ernahrung,' Zierassen's Handhiichder Hygiene, 1882. 
 
 • Zeits. fur Biologic, vol. vii. 1871. 
 
FOOD 421 
 
 '(33'8 oz.) of peas 15 per cent, is passed out in the feces ; but with GOO 
 grammes (21 oz.) only 10 per cent, is lost.^ 
 
 Fats when taken in as food are acted upon by the bile and pancreatic juice 
 in the small intestines ; for the most part they are emulsified and absorbed 
 by the mucous membrane direct (probably by means of the epithelial cells 
 and the leucocytes), but they are also in part split up into fatty acids and 
 glycerine, the acids uniting with the alkalies present to form soaps which are 
 absorbed. An excess of fat in the diet is passed off in the faeces, and may 
 lead to great digestive disturbance by being split up into fatty acids by means 
 of bacteria. Nothing very definite can be stated as to what is an excess of 
 fat in a diet ; what is excess for one individual is readily digested by another, 
 the labourer eats an amount of bacon fat which would nauseate and disturb 
 'the digestion of another person not doing so much work. 
 
 Bertha's experiments (quoted by Parkes) show that 30 grammes of 
 animal oil added to the ordinary diet were absorbed ; but with increasing 
 quantities less was absorbed, and if 60 grammes were continued in the 
 <daily diet for some time, 50 grammes passed away by the intestine. 
 
 Animal fats are more digestible than vegetable, and it is from animal 
 food and products that the fats of a diet are derived. 
 
 The reaction of food is also an important point. As a rule it is slightly 
 .alkaline, and this stimulates the flow of the gastric juice. If too alkaline, it 
 will tend to neutraUse the acid in the stomach, and thus to Innder digestion. 
 The usual mistake is, however, that the food is too acid. The excess of 
 acidity is usually due to the vegetable acids, vinegar, lactic, tartaric, or citric 
 acid. The excess of these acids, especially when a large amount of carbo- 
 hydrates exists in the food, tends to diminish digestion and absorption of the 
 food, and will if persisted in lead to dyspepsia. 
 
 There are other considerations with regard to the digestion of food which 
 may be briefly summed up. Sleep diminishes digestion, and, therefore, 
 food ought not to be taken just before going to sleep. Food taken too often 
 also tends to diminish the activity of the digestive juices, and gives no rest 
 to the ahmentary tract. According to Eanke, laborious ivorh diminishes 
 digestion ; but Forster considers that it has no great influence on it. The 
 eflect of work on digestion probably, however, differs in the labouring man 
 -and in the well-to-do. 
 
 3. Preparation and Cooking op Food 
 
 Civilised man requires the majority of articles of food to be prepared and 
 to be cooked. And the higher the civilisation, the more is the food elaborated 
 :in its preparation, and the more complicated the process of cooking. 
 
 1. Preparation of Food 
 
 This is necessary with those foods which contain a large proportion of 
 indigestible matter. Thus the grain of the wheat, containing internally the 
 starch and proteid food, is separated from its covering, which, although rich 
 in salts, contains much indigestible cellulose. The starch and proteid are also 
 subjected to a process of grinding, and finally are manufactured into bread, 
 which may be considered as a partially digested food (see sub-section Bread). 
 The removal of the grain-covering and the grinding of the grain-contents and 
 the making of bread are all processes which enable the digestive organs 
 1)0 obtain the greatest amount of nutriment from the wheat-graio, a gain 
 * Zeits. fur Biologic, vol. xvi., 1880. 
 
422 HYGIENE 
 
 which more than compensates for the loss of salts contained in the grain- 
 covering. 
 
 Other cereals are also prepared and made into flours with the object of 
 removing most of the cellulose. The rougher parts, too, of ordinary vege- 
 tables are also removed for a similar reason. Animal foods do not require 
 so much preparation as vegetable— the removal of tendon from meat is the 
 chief point to be attended to. 
 
 2. Effect of Cooking 
 
 The general effect of cooking is to increase the digestibility of food. This 
 is more marked in the case of vegetable food than in that of animal. The 
 cooking also of animal food especially develops ' flavours ' in the food; which 
 is an important point, since tasteless food cannot for long be eaten. Flavour- 
 ing agents are thus often added to increase the savouriness of food (see Food- 
 Accessories). Another result of cooking food is the advantage of taking food 
 hot ; cold food has to be raised to the internal temperature of the body, and 
 thus when food is hot less heat is abstracted from the surrounding parts. 
 
 Cooking is also a prophylactic measure. The temperature to which well- 
 cooked food is exposed is sufficient to destroy the numerous parasites which 
 may be present in meat, such as the cysticerci of tapeworms, and other worms, 
 and to some extent to destroy any bacteria present. A much higher and more 
 prolonged temperature is necessary to completely destroy the micro-organ- 
 isms present in food, as the presence of numerous bacteria in the digestive 
 tract testifies. 
 
 Vegetables, such as peas, beans, &c., take up during the process of cooking 
 a large percentage of water (see Table, p. 423). They lose a certain proportion 
 of salts, which escapes, if they are boiled in much water. They are best 
 cooked, therefore, with a minimum of water, some fat and salt being added 
 dming the process. The chief effect on the organic foodstuffs in the cooking 
 of vegetable food is that part of the proteids (the globulins and albumins) is 
 coagulated by the heat to which they are subjected, the remainder of 
 the proteids ('legumiu,' albumose) being imaffected by the heat, while the 
 starch undergoes a complete change. Whether the coagulated proteids are 
 more digestible than the uncoagulated is not at present certain ; the heating, 
 however, certainly renders them less liable to be decomposed by the bacteria 
 constantly found in the digestive tract. The starch-grain is in the uncooked 
 state hard and not readily affected by the digestive juices. This is chiefly 
 due to the fact that the grain is composed of starch (granulose) and a Httle 
 erythrogranulose, which are both enclosed in cellulose coverings. The 
 efi'ect of moist heat is to burst the coats of cellulose, so that the grain swells 
 and the starch is practically set free. By boiling, the starch is converted 
 partly into so-called ' soluble ' starch, which, although of the same chemical 
 composition as natural starch, is more readily acted upon by the ferments of 
 the saliva and pancreatic juice. The process of the manufacture of bread 
 must be considered as a partial artificial digestion, since some of the starch 
 of the flour is transformed into dextrine and maltose, the gluten being: 
 semi-coagulated. 
 
 Animal food is as well digested artificially in the fresh state as when 
 cooked. But cooking is necessary, as it diminishes the time of mastication 
 and increases the savouriness of the food. Unlike vegetable food, animal 
 food loses instead of gains weight during cooking. The loss is chiefly water, 
 but is also due to some fat, salts, and extractives. The following table showa- 
 the proportional loss or gain in both kinds of food : — 
 
FOOD 
 
 423 
 
 Table showing Amount of Water in Foods before and after Cooking (Furster) 
 
 Fresh Foods 
 
 Beef (Wolff) 
 
 Percentage 
 75 
 
 Veal (Wolff ) 78 
 
 Wheaten flour 12-14 
 
 Peas li 
 
 Potatoes 
 Cabbage 
 
 75 
 
 87 
 
 Cooked 
 
 rernentage 
 . 55-69 
 . 56-63 
 . 60-64 
 . 36-40 
 
 Boiled .... 
 Boast .... 
 Boast .... 
 Bread .... 
 
 Mashed peas 68-78 
 
 Pea-soup 90 
 
 Mashed potatoes .... 78 
 
 Potato soup 91 
 
 85-90 
 
 As regards other a,nimal foods, mutton loses in weight rather more than 
 beef during cooking (Letheby). 
 
 Loss in Percentage of Weiglit in Meat during Cooking 
 
 - 
 
 Boiling 
 
 Baking 
 
 Boasting 
 
 Beef ..... 
 Mutton 
 
 20 
 
 20 
 
 29 
 31 
 
 31 
 35 
 
 In all forms of cooking large pieces of meat, the first object is to rapidly 
 coagulate the external parts, so that during cooking the juice of the meat 
 should be retained as far as possible. After the coagulation of the external 
 parts, the process of cooking ought to be conducted at a low temperature, 
 not exceeding 160° F. (about 71° C.) Thus, in boiling, the meat ought to be 
 steeped for five minutes in boiling water ; in roasting, the joint must be 
 exposed quite close to the fire at first till the outer parts are hard, when it 
 can be removed farther off. The reason why meat should be cooked at a 
 temperature not exceeding 70° C. is that most of the proteid matter of the 
 meat coagulates between 65° and 75° C. ; the object is to leave some of the 
 proteid in a semi-coagulated state ; but by increasing the heat over 70° C. 
 up to the boiling-point (100° C.) the proteid matters are not only completely 
 solidified, but become, from their hardness, indigestible. Over-heating is, 
 therefore, to be avoided ; and the slower the cooking, the better the result. 
 In meat the chief proteid is the myosin of the muscle fibre ; there is also 
 the serum of the blood in the blood-vessels and the fibrin of the clot with the 
 hemoglobin. The myosin is soft just after death, but coagulates soon after- 
 wards, sarcolactic acid being developed as well. This coagulation is called 
 rigor mortis. After a time rigor mortis passes off and the myosin becomes 
 softer again ; the meat is then ready for cooking. In hunted and over- 
 driven animals, rigor mortis is early in appearing. 
 
 In between the muscle fibres is connective tissue, the collagen of which, 
 during cooking, yields gelatine. The dissolved gelatine partly escapes with 
 the melted fat out of the meat, and the muscle fibres are thus loosened, 
 and rendered more easy to chew. There is also a great loss of salts — more 
 in boiling than in roasting meat. 
 
 To sum up the changes that occur during the cooking of animal food : 
 there is a gradual and not complete coagulation of the proteid constituents 
 of the food, the formation of gelatine chiefiy from the connective tissues, 
 causing partial disintegration of the tissue, and finally a loss of salts. 
 
 Soups and broths are best considered as food-accessories, and their effect 
 will be considered under that head. Simple soups contain some of the salts 
 of meat (potassium and phosphates) with added sodium chloride, and the 
 
424 HYGIENE 
 
 extractives of meat, together with the aromatic products (sometimes called 
 osmazome). The chief proteid they contain is gelatine derived from the 
 connective tissue of the meat. The aromatic products differ as to whether the 
 broth is made from beef, mutton, chicken, &c. Broths often have vegetables 
 added to them, potatoes, carrots, &c. 
 
 For the action of soups and broths see Food-accessokies (p. 477). 
 
 The Diseases caused by Food 
 
 In the preceding pages the data on which food must be taken have been 
 given. It has been shown that not only must there be a certain amount of 
 foodstuff's present in the food, but the food must be in a digestible form and 
 must be properly cooked. If these points are not attended to in a dietary, 
 the food ingested does not perform its functions ; it does not support the 
 nitrogen equihbrium, nor does it supply sufficient material for the energy 
 required by the body. The evils that may arise from indigestible food have 
 already been discussed (Digestibility op Food, p. 420), as well as those 
 arising from bad cooking. There remain for consideration the bad effects 
 which arise from an excess of food, from a diminution of it, or from diseases 
 communicated by it. This last point will be left for discussion after each 
 separate article of food has been treated. 
 
 Effect of an Excess of Food 
 
 The effect of over-feeding is more often noticed in the well-to-do than in 
 the poorer classes. In many cases it is simply a habit, but one which leads 
 to serious consequences. A very large excess of food, as we have seen, throws 
 great work on the digestive system, so that the digestive juices cease to 
 secrete and the peristalsis of the stomach and intestines fails to propel the 
 food along. The result of this is a putrefying and fermenting mass in the 
 intestines, which may be large in amomit and may necessitate removal by 
 artificial means ; or it may be discharged by setting up diarrhoea. Although 
 not commonly of such a severe type, the symptoms of an excess of food are 
 often present in large eaters. Excess of food, therefore, primarily causes 
 mdigestio7i, with diminished absorption. But more food than necessary may 
 be absorbed, so that the body gains weight considerably, as Voit has shown, 
 the gain being chiefly in the form of fat. An excess of proteid food (chiefly 
 of animal food) throws, as we have seen, great work on the nitrogenous 
 tissues, so that disorders of the hver and muscles follow ; it is considered, too, 
 as one of the factors in the production of gout. And if proteids are taken in 
 excess while the fat and carbohydrate of the diet are in small proportion, the 
 body loses in weight, and this loss is chiefly fat. For although it has been 
 clearly demonstrated that proteids are to some extent a som'ce of fat in the 
 body, they cannot replace the fat in the food ; so that when a diet is greatly 
 deficient in fat and carbohydrate, the body draws on its own store of fat, 
 which then gradually disappears. These facts are the explanation of the 
 Banting cure of obesity. The amount of stored-up fat which is destroyed 
 depends, therefore, on the quantity of fat in the food and that in the body. 
 
 Other facts are important in the consideration of the effect of an excess of 
 proteid food in the body. These are that the decomposition of proteid in the 
 body is proportional to the intake, even if large quantities be taken ; in other 
 words, the excretion of urea augments with the increase of proteid in the 
 food. As a corollary of this, it may be stated that the amount of proteid 
 taken in the body is proportional to the oxygen absorbed in the lungs ; for if 
 
FOOD 425 
 
 there is aiii excess of proteid, there must be an excess of oxygen (above the 
 normal) to oxidise it.^ 
 
 An excess of fats and starches in the dietary tends to produce corpulence 
 and dyspepsia. As we have seen, both the fat of the food and the carbo- 
 hydrates lead to the deposition of fat in the body. The excess of fat and 
 starch also partly passes away in the faeces, or after absorption some of the 
 starch may pass away in the urine as dextrose. 
 
 But little is known of the effect on the body of an excess of mineral food. 
 Two points may, however, be mentioned. An excess of potassium salts in the 
 food withdraws sodium and chlorine from the tissues and causes an increased 
 excretion of sodium chloride. This occurs when vegetable food forms the 
 chief part of a diet, since such food contains a large quantity of potassium 
 phosphates. The necessity of sodium chloride for vegetable feeders is thus 
 •explained.^ 
 
 An excess of water in the food is not stored up in the body, but is excreted 
 by the urine. The excess over the normal does not simply filter through the 
 body, but it has an effect on the tissues. Thus it tends to produce oxidation 
 of the proteid of the body, and a great excess may even lead to hypertrophy 
 of the heart and fatty degeneration (Buhl, quoted by Forster). 
 
 Sodium chloride in excess increases the metamorphosis of proteids in the 
 body.^ 
 
 Effect of Diminution of Food 
 
 The complete withdrawal of food, or an insufficient supply of it, leads to 
 ■the phenomena of starvation, with symptoms more or less intense. The 
 -complete withdrawal of food leads to rapid wasting of the body, dryness of 
 the mucous membranes, weak action of the heart and of the respiratory 
 system, and on the part of the nervous system to restlessness and delirium, 
 ending in coma. A vigorous adult dies when he loses two-fifths of his body- 
 weight ; the young succumb sooner,* More important, however, from the 
 point of view of hygiene, than the effect of complete withdrawal of food is the 
 effect of an insufficient supply. In public institutions, prisons, workhouses, 
 orphan asylums, &c., and in the army and navy, where there is a prescribed 
 diet, it is evident that an inadequate supply of food may be fraught with 
 disastrous consequences to large bodies of individuals ; and especially is this 
 so with the young, for inadequate nourishment during the growing period 
 leaves its stamp on the organism for Hfe. A general diminution of all the 
 foodstuffs in a dietary, if continued for some time, leads to a general weaken- 
 ing of the body, and so exposes the individual to greater danger from the 
 effects of specific fevers and disorders and from the effects of cold; and 
 especially is this so if work has to be done on an insufficient diet, for in 
 this case work is added to the balance against the individual. 
 
 In the previous pages it has been pointed out in what respects the diets 
 of communities living together are deficient. Proteids and fats, especially 
 •the latter, are the two chief foodstuffs deficient in their dietaries ; and by 
 an increase of the fats of the diet, the health of the communities is undoubt- 
 edly greatly improved. It has even been considered that the occurrence of 
 scurvy in prisoners may be connected with a deficiency of animal fat in the 
 
 * Some of the absorbed proteid may not be oxidised, and thus pass out of the body in 
 ;the urine ; excess of proteid food is thus considered one of the causes of functiotial 
 .albuminuria. 
 
 2 See Bunge, Zeits. f. Biol. Bd. ix. 1873, p. 104 ; ibid. Bd. x. 1874, p. 111. 
 ^ Voit, Einfluss des Eochsalzes u.s.w. auf d. Stoffwechsel. Miinchen, 1860. 
 
 * For fuller details see works on physiology. 
 
420 HYGIENE 
 
 diet.' The most that can be said of this, however, is that it may be a part 
 of the history of scurvy. 
 
 The eflects of a diminution of proteids have ah-eady been considered, as 
 well as that of a diminution of fats and carbohydrates in the diet ; we may 
 repeat that a diminution of nitrogenous food leads to increased oxidation of 
 the body proteids, i.e. to a loss from the body, in order that the nitrogea 
 equihbrium may be maintained. Fats and carbohydrates are, as has been 
 shown, eminently proteid- sparing foods ; therefore the diminution of them in 
 the diet leads either to increased ingestion of proteids in the food or to an 
 increased destruction of proteids in the body. 
 
 With regard to mineral foods , the effect of this diminution in the diet has 
 been already for the most part discussed in treating of the necessity of the 
 earthy phosphates for the growing organism, and that of sodium chloride to 
 vegetable feeders. The salts of the body exist in two forms, the body-salts 
 or those united with the tissues, and the floating salts or those dissolved in 
 the fluids (Forster). These bear a certain proportion to each other ; and if 
 the floating salts are not replaced by the salts of the food, the body- salts are 
 more or less withdrawn from the tissues. In scurvy, for example, there is. 
 a diminution of potassium salts in the body ; and this is considered one of 
 the factors of the disease. Forster (quoting Felix) says that there may also 
 be excessive excretion of potassium salts in the urine when salt-junk is eaten. 
 Ammonium chloride (and probably sodium chloride) increases the excretion 
 of potassium salts : hence the effect of salt-junk may possibly be explained. 
 On the other hand, the beneficial effect of lime-juice in scurvy has led 
 some to consider that there is a connection between the disease and the 
 ingestion of vegetable acids (citric, tartaric, &c.), although it has been shown 
 that these acids of themselves have no curative powers in scurvy. 
 
 Diminution in the amount of wate7' leads to storage of water in the body, 
 especially in the muscles, and this, like an excessive ingestion of water, 
 leads to the destruction of body-proteid. The tissues in this watery condi- 
 tion are deficient in activity, and this condition may, according to Forster, be- 
 connected with the predisposition of the lower classes to infectious diseases, 
 and in general with a diminished resistance against disease. Scurvy is 
 specially considered after Lemon-juice (p. 474). 
 
 ABTICLES OF FOOD 
 Anibial Foods 
 
 Articles of diet derived from the various parts of animals are important 
 in several ways. First, they are pre-eminently proteid foods. In them, 
 speaking generally, the proteids exist in large proportion ; are, as a rule, easily 
 digested ; and are not mixed with substances (such as cellulose) which inter- 
 fere with digestion. 
 
 Second, most of the fat taken as food is derived from animal products. 
 The fat forms part of the various kinds of edible flesh, of milk, and is sepa- 
 rated as butter, suet, lard, &c. These fats are more easily digested and more 
 readily assimilated than vegetable fats. 
 
 Third, animal foods are one of the sources of sodium chloride, which ia 
 necessary for existence. Thus, although the solid tissues themselves con- 
 tain an excess of phosphates and of potassium over chlorides and sodium,. 
 yet in the liquids which bathe the solid tissues, e.g. the liquid round the- 
 muse alar fibres or the liquid part of the blood in the muscle, and in fact iiL 
 
 ' Konig, op. cit. Bd. i. p. 171. 
 
FOOD 
 
 427 
 
 all animal liquids, this relation is reversed. The fact has already been referred 
 to, that with vegetable feeders common salt is a necessity which has to be added 
 to the food, whereas with animal feeders it is not so imperatively called for. 
 
 Fourth, a great distinction between certain vegetable foods and animal 
 foods is that the latter do not possess to any degree an antiscorbutic power. 
 It is true that in the ' Eira ' Arctic Expedition, fresh meat (walrus) was found 
 to prevent an outbreak of scurvy in the men ; but, as a rule, it may be said 
 that fresh meat is not to any extent antiscorbutic. 
 
 It may agam be pointed out that cooking is all- important for animal foods, 
 not only to render the food more digestible, but also to destroy parasites 
 (see Cooking of Food, p. 421) ; and this remark applies to the boiling of 
 milk as well as to the cooking of the solid animal foods. 
 
 Milk (and to some extent liver) is the only animal food which may be 
 considered a carbohydrate food. 
 
 MILK AND MILK-PRODUCTS 
 
 The chief forms of milk and milk-products may be arranged as follows : — 
 
 1. Milk from the cow, buffalo, ass, goat, and mare ; human milk. 
 
 2. Milfc-products. 
 
 Unaltered from natural milk : — 
 
 a. Skimmed milk, including various forms. 
 h. Cream. 
 
 c. Butter. 
 
 d. Condensed milks. 
 
 Altered from natural milk by decomposition or fermentation : — 
 
 e. Cheese. 
 
 /. Koumiss and Kephir. 
 
 3. Prepared milk-foods for infants and invalids. 
 
 Composition of diffebent Milks 
 
 All forms of milk are emulsions of fat containing proteids, carbohj'drates, 
 and salts in solution in water. In the following table (summarised from 
 Konig) the average composition of milks is given in percentages, i.e. in 
 100 cubic centimetres is contained the dried weight of foodstuffs in grammes 
 stated. 
 
 Composition of Milks in 100 parts (average of many analyses) 
 
 - 
 
 Sp. gr. 
 
 Total 
 solids 
 
 Pro 
 Casein 
 
 ;eid 
 Albumin 
 
 Fat 
 
 Lactose 
 
 Salts 
 
 Water 
 
 Proportion 
 of nit. to 
 non-nit. as 
 
 Mare's . 
 Ass's 
 Human . 
 Cow's . 
 Goat's . 
 Buffalo's 
 
 1035 
 1023-1035 
 1027 
 103ii 
 1032 
 1032 
 
 9-22 
 10-36 
 12-59 
 12-83 
 14-29 
 18-59 
 
 1-24 
 
 0-75 
 
 1-21 
 1-64 
 3-78 
 3-69 
 4-78 
 7-47 
 
 5-67 
 5-99 
 6-21 
 4-88 
 4-46 
 4-15 
 
 0-35 
 0-51 
 0-31 
 0-71 
 0-76 
 0-87 
 
 90-78 
 89-64 
 87-41 
 87-17 
 85-71 
 81-41 
 
 1 : 3-4 
 1 :3-4 
 1:4-4 
 1 :2-5 
 1:2-0 
 1:1-9 
 
 1-99 
 0-67 1 1-55 
 
 2-22 
 1-03 1 1-26 
 
 2-29 
 3-02 1 0-53 
 
 3-55 
 3-20 1 1-09 
 
 4-29 
 5-85 1 0-25 
 
 6-10 
 
428 HYGIENE 
 
 The kinds of milk important from the point of view as food to man are 
 human milk and cow's. They differ in the following particulars : as regards 
 the proteids, human milk differs from cow's in havini^ less casein but more 
 albumin ; the fat is about the same in both kinds, there is more sugar in 
 human than in cow's milk, but less salts. 
 
 The salts of milk are composed of all the constituents necessary to the 
 growing organism : calcium, sodium, potassium, chlorides, phosphates, and 
 iron. As in most foods, the potassium and phosphates are in excess. The 
 calcium phosphate present aids in the solution of the casein. Besides the 
 mineral salts, there are organic compounds, such as urea, creatin, sarkin, 
 ttc, which are included under the term extractives. 
 
 Percentage of Salts in the Ash of Human Milh.^ 
 
 NaCl 10-73 
 
 KCl 26-33 
 
 KHO 21-44 
 
 Ca 18-78 
 
 Mg 0-87 
 
 V.O, 19-0 
 
 Fe.,P.,0=, 0-21 
 
 HoSO^ 2-64 
 
 Silica Trace 
 
 Variations in the Composition of Cow's Milk 
 
 1. Time after Calving. — The first milk, or colostrum, varies greatly from 
 that subsequently secreted. It contains, like the colostrum of human milk, a 
 large quantity of serum-albumin, a larger quantity than normal of casein ; 
 while the lactose is diminished. The mean of many analyses given by Konig 
 is 74-67 percent, of water ; 4-04 of casein, 13-6 of albumin ; 3*59 of fat, 2-67 
 of lactose, and 1*67 per cent, of salts. 
 
 After the colostrum, the milk varies shghtly in quaHty, being at first 
 mixed with the colostrum. 
 
 Up to the second month after delivery, the casein and fat are increased. 
 From the tenth to the twenty-fourth month the casein diminishes, while the 
 fat becomes less from the fifth to the sixth month, and the tenth to the 
 eleventh. The sugar is diminished during the first month, but increases from 
 the eighth to the tenth month. The salts increase up to the fifth month, after 
 "which they steadily diminish.^ 
 
 2. The Race of the Goto. — Some milks are rich in fat, others in casein. 
 
 3. The Kind of Feeding. — Fodder rich in carbohydrates, such as beet, 
 carrot, &c., causes an increase of the amount of sugar in the milk. An in- 
 crease of proteids in the diet causes an increase of the casein, while the fat is 
 not much influenced. 
 
 The age of the cow and the number of pregnancies also affect the compo- 
 sition of the milk. 
 
 Milk as an Abticle of Diet 
 
 Milk is the chief diet for children up to the age of eighteen months or two 
 years : its value has already been partly pointed out (p. 410). It is almost 
 completely digested in the iatestiaes : when exclusively used for adults, it 
 
 * The composition of the ash of cow's milk is similar. 
 * Landois and Stirling's Physiology, 3rd ed. p. 347. 
 
FOOD 
 
 42? 
 
 leads to constipation. When digested either by pepsin or the pancreatic juice, 
 milk clots, the casein being precipitated in large curds. This is the first 
 stage of digestion ; the curds are then changed into albumoses and peptones hy 
 the ferments, a bitter substance being formed which makes the peptonised 
 milk unpleasant to the taste. 
 
 For infants, human milk contains the nitrogenous and the non-nitro- 
 genous organic foodstuffs in the right proportion, viz. 1 : 4*4 ; and so does 
 mare's or ass's milk. But in cow's milk the proportion is 1 : 2*5, and 
 therefore cow's milk is not a perfect food by itself. If the non-nitrogenous 
 organic foodstuffs are increased, as by adding sugar or arrowroot to the milk,, 
 it then becomes a very important food. Such additions are made for young 
 children and in the dietary of adults. 
 
 As cow's milk has often to be substituted for human milk in the rearing 
 of children, it is important in many instances to artificially bring the compo- 
 sition of the milk to that of human milk. This is done in the following 
 manner : the cream is separated from a pint of milk, and the casein of one- 
 half of the skimmed milk coagulated with a small quantity of rennet and 
 strained off. To this whey the cream which has been removed and the 
 rest of the skimmed milk is added. The composition of this artificial 
 human milk varies : it contains on the average a little over 2 per cent, of 
 proteid, 4*5 per cent, of fat, 5 per cent, of lactose, and 0'6 per cent, of salts. 
 Li feeding infants, the cow's milk has to be diluted ; for, containing much, 
 casein, this forms large clots in the stomach, which cause indigestion. 
 Dilution diminishes the size of the clots of casein, and in many instances 
 this is suflficient ; lime-water or barley-water added is also beneficial in some 
 cases. After dilution, the addition of sugar to the cow's milk is necessary to 
 bring it nearer to the standard of human milk. Spiegelberg ^ says that during 
 the first three or four weeks of life two parts of water must be added to 
 one part of milk ; after the third and fourth months, more milk may be 
 given, till from the fifth and sixth months the child may have undiluted, 
 milk. The milk has often to be more diluted than this. To each litre of 
 diluted milk thirty grammes of milk-sugar must be added. 
 
 Percentage Composition of diluted Milk and added Lactose 
 
 - 
 
 Proteid 
 
 Fat 
 
 Sugar 
 
 Salts 
 
 Water 
 
 Proportion 
 of nit. to 
 non-nit. as 
 
 Cow's milk with equal parts of water . 
 Cow's milk with two parts of water 
 
 1-77 
 1-18 
 
 1-85 
 1-23 
 
 5-44 
 4-68 
 
 0-35 
 0-23 
 
 92-73 
 90-59 
 
 1 :4 
 
 1 :4-8 
 
 During the first half-year a child weighing 5 to 6 kilogrammes consumes 
 1 to 2 litres of mother's milk daily, i.e. in a litre nearly 30 grammes of 
 proteid, 39 grammes of fat, 62 grammes of sugar, and 3 grammes of 
 salts. To obtain a similar amount of foodstuffs, it would require to take daily 
 3 litres of milk diluted with 2 parts of water ; it would, however, be then receiv- 
 ing nearly 140 grammes of lactose. 
 
 Ass's milk is nearest in composition to human milk, and is sometimes used 
 as a substitute : its chief deficiency is in the amount of fat. Mare's milk 
 contains less proteids and fat than ass's milk ; while goat's milk and buffalo's 
 are very rich in fat, the former having a pecuUar smell. 
 
 ^ Midwifery, New Syd. Soc.'s Trans, vol. i. 1887, p. 829. 
 
430 HYGIENE 
 
 One litre of cow's milk (35 ounces) contains — 
 
 35-0 grammes of proteid 
 36-9 „ fat 
 
 48-8 „ lactose 
 
 7"1 „ Baits 
 
 and 871'7 „ water 
 
 Sucli a quantity, then, contains half the daily quantity of proteids, and 
 more than half the daily quantity of fat necessary for a child from six to 
 fifteen years of age. 
 
 An adult would require 5 Htres (ahout 9 pints) of milk daily to obtain the 
 requisite amount of proteids, 180 grammes ; and then he would be taking 180 
 grammes of fat, and only 240 grammes of carbohydrates. Milk, being easily 
 digested, is a useful article of diet in certain cases of mal-assimilation of food 
 or in old age. 
 
 Diseases Caused by Milk and Milk-peoducts 
 
 1. Milk after standing for some time becomes sour and coagulates. This 
 effect is due to the bacillus acidi lactici, so named because lactic acid is the 
 chief product of its activity, carbonic acid being at the same time formed. 
 Such milk is a fruitful source of digestive trouble in infants, and is unfit for 
 food. It leads to vomiting, flatulence, and diarrhoea. To sour milk are 
 to be ascribed many of the cases of infantile diarrhoea. 
 
 Blue milk is not common. The colouration is due to the growth in the 
 milk of the bacillus cyanogemis, which is itself colourless, but imparts a 
 blue colour to the milk, intensified if the lactic acid fermentation also 
 occurs. The blue colour was at one time ascribed to the eating of cer- 
 tain meadow-plants. Blue milk causes irritation of the stomach and in- 
 testines, producing diarrhoea. 
 
 Many micro-organisms produce coagulation of milk, e.g. the bacillus 
 butyricus of butyric acid fermentation. Other fungi turn the milk bluish 
 black or green. Yelloio milk is due to bacterium synxantlium, which 
 makes the milk first acid, then strongly alkaline. Bed milk is due to micro- 
 coccus inodigiosus ; the change was formerly ascribed to disease of the cow. 
 Both the colouring matters of yellow and red milks are related to anihne. 
 Milk may also become stringy or ropy, due to the action of bacteria. 
 
 2. Besides these visible changes in the milk, occurring after the milk 
 has been drawn, there are others which are present in the milk when 
 drawn. 
 
 a. Many substances are excreted in the milk when given to the mother 
 or taken in loith the fodder of the animal. Iodides, arsenic, antimony, 
 mercury, carbohc and sahcylic acids, rhubarb, and opium may thus be present 
 in the milk and affect the child. Castor oil also when taken by the mother 
 acts, as is well known, as an aperient to the child. 
 
 Turnips, diseased potatoes, and other plants in the fodder of the cow may 
 impart an unpleasant aroma to the milk without altering its efficacy as an 
 article of diet. But some other kinds of fodder produce poisonous milk, 
 owing to the excretion of poisonous substances. For example, the milk of 
 goats which have eaten colchicum or Euphorbiaceous plants produces 
 poisonous symptoms, including diarrhoea. The milk from cows feeding on 
 wort is injurious.^ The Ii7t7(s toxicodendron olso i^roduces poisonous milk; 
 children partaking of it suffering from weakness, vomiting, and constipation. 
 
 ' Forster, op. cit. p. 159. 
 
FOOD 
 
 431 
 
 The plant also causes ' trembles ' in the cows. The poison is destroyed by 
 boiling the milk. 
 
 h. The milk 7nay he affected by the diseased condition of the cow. The 
 mammary gland of the animal may be affected with disease ; it may be 
 
 Fig. 87. Human milk with colostrum 
 corpuscles {a). (Carpenter.) 
 
 Fig. 88. — Milk iu foot-and-mouth disease, 
 showing clustered milk corpuscles and 
 Isacteria (early stage).'- 
 
 Fig. 89. — Milk in foot-and-mouth disease (late stage).'- 
 1 & 3. Granular corpuscles. 2. Milk corpuscles. 4 & 5. Bacteria. 
 
 acutely inflamed (acute mastitis) or chronically (interstitial mastitis), or it 
 may be tubercular. Pus may then be present in the milk as well as tubercle 
 bacilli. The analysis by Flirstenberg of milk from a cow with interstitial 
 hyperasmia of the mammary gland shows a varying composition. In one 
 
 ' Figs. 88 and 89 are taken from tlie Lancet, vol. ii. 1869, p. 590. 
 
432 
 
 HYGIENE 
 
 animal the milk contained 5-78 per cent, of proteid, with only a trace of fat 
 and lactose ; in another the proteid was still higher— 8-89 per cent., while 
 the fat and salts were increased and the lactose helow normal ; in a third the 
 composition of the milk was within the normal limits. In acute mastitis 
 the casein, fat, and sugar were found diminished, while the albumin was 
 greatly increased— 5-3 per cent. (Fiirstcnbcrg, quoted hy Konig).^ 
 
 In foot-and-month disease {eczema epizootica) the milk varies in com- 
 position greatly, and under the microscope pus and blood corpuscles are 
 often seen (figs. 88 and 89). The following analyses (quoted by Konig) show 
 this : — 
 
 Composition of Milk in Foot-and-Month Disease 
 
 - 
 
 Water 
 
 Casein 
 
 Albumin 
 
 Fat 
 
 Lactose 
 
 Salts 
 
 Acute stage . 
 
 87-70 
 
 3-90 
 
 3-90 
 
 3-81 
 
 - „', ^ Lassainne 
 
 During convalescence . 
 
 90-60 
 
 2-85 
 
 2-30 
 
 3-02 
 
 
 On '2nd daj' of disease . 
 
 79-90 
 
 — i 14-38 
 
 5-01 
 
 — 
 
 0-711 
 
 0-21 I Wynter Blyth 
 
 On 4tli day of disease . 
 
 83-85 
 
 3-47 
 
 7-80 
 
 4-67 
 
 On lith day of disease . 
 
 83-88 
 
 — 1 11-48 
 
 3-9(5 
 
 — 
 
 0-G8 1 
 
 The composition of the milk, therefore, varies greatly ; the chief point in 
 Wynter Blyth's analyses is the great excretion of serum-albumin in the milk. 
 The milk from cows suffering from foot-and-mouth disease may, according 
 to some, cause disease in the human being, and especially in the case where the 
 udder of these cows is in an aphthous condition. ^ The symptoms are 
 limited to the mouth, and consist in aphthous ulceration, with hyper^emia 
 and the formation of a membrane, and swollen tongue (Parkes). The milk 
 is fatal to calves and to young pigs.- 
 
 Tuberculosis in cows {Perlsucht) affects the milk, and may lead to the 
 same disease in man. A distinction must be drawn between the milk from 
 cows with tubercular udders and that from animals with general tuberculosis 
 only, since, according to Bang, tubercle bacilli are rare m milk unless the 
 udder is tuberculous. Animals can be given tuberculosis by feeding them 
 with milk from tubercular cows (Bollinger). Boiling the milk is a preventive 
 measure, as the tubercle bacilli are destroyed by heat. The composition of 
 the milk varies from the normal. If the glands are themselves tubercular 
 the secretion is strongly alkaline. The mean of three analyses by Storch ^ of 
 milk taken at different times from the same cow is 87'52 per cent, of water, 
 5-58 per cent, of proteid, 4-29 of fat, 1-65 of lactose, and 0-96 of salts. 
 Lehmann, however, found in the milk of a tubercular cow only a small pro- 
 portion of casein and fat, and Forster * in another case found a large quantity 
 of proteid and fat, but only 1-06 per cent, of lactose — a result more closely 
 resembhng Storch's analysis. 
 
 The milk from cows suffering from cattle-2)lague {Binderpcst) is altered in 
 composition. According to Monier's analyses it contains a large proportion 
 of casein (8"2 to 10-12 per cent.), a trace of albumin (0-49 to 0-85 per cent.), 
 a large proportion of salts (1*12 to 1"59), while in the late stages of the dis- 
 ease there is a great diminution in the amount of fat and sugar. 
 
 Power and Klein have described a disease of cows which leads them to 
 think that scarlet fever may be transmitted by the milk to man. The 
 organisms found in scarlet fever and in the cow disease (at Hendon) were 
 described as identical.^ 
 
 » Forster, loc. cit. * Lancet, vol. ii. 1869, p. 590. 
 
 3 Quoted by Konig, op, cit. p. 332. * Op. cit. p. 161. 
 
 * For the controversy on this subject see the medical journals, 1888-9. 
 
FOOD 
 
 433 
 
 3. After being drawn the milk may be infected, and it is in this -way that 
 milk has been supposed to be the vehicle for the poisons of typhoid fever 
 and diphtheria and many cases of scarlet fever. Cases of these diseases 
 have been present near the dairy, and the milk has become infected either 
 directly or by the use of water impregnated with the poison. 
 
 One of the best prophylactics against diseases arising from the use of milk 
 is boiling the milk ; this ought always to be done in summer and winter. 
 
 Peeseevation op Milk 
 
 Cow's milk may be preserved by boiling, and tightly corking the vessel. 
 The preservation is, however, only temporary. Antiseptics may be added 
 after boiling, such as salicylic acid, boric acid, boroglyceride, sulphurous 
 acid. Of these the most innocuous are boric acid and boroglyceride. 
 
 The best forms of preserved milks are the concentrated forms — the con- 
 densed milks, with or without the addition of sugar, and the dried milk. 
 
 In condensed milk without the addition of sugar the preparation is sold 
 in tins, and the milk does not keep for very long after the tin is opened. 
 The sweetened condensed milks keep for a month or longer after opening. 
 
 Scherff's preserved milk is condensed to one-half or one-third of the 
 original bulk. 
 
 Percentage. Composition (average) of Condensed Milks ' 
 
 - 
 
 AVater 
 
 Proteid 
 
 Fat 
 
 Lactose 
 
 Cane- 
 sugar 
 
 Salts 
 
 Proportion of 
 
 nitrogenous to 
 
 non-nitrogenous 
 
 food-stuffs as 
 
 Condensed milk with added 
 
 cane-sugar 
 Do. without added sugar 
 Scherff's condensed milk 
 
 25-61 
 
 59-00 
 
 72-87 
 
 11-79 
 
 11-92 
 
 8-20 
 
 10-35 
 
 12-42 
 
 6-62 
 
 13-84 
 15-48 
 10-63 
 
 36-22 
 
 2-19 
 2-18 
 1-68 
 
 1 :5-2 
 1 :2-3 
 1 :2-l 
 
 Some preparations of condensed milk contain more sugar than the aver- 
 age given above. 
 
 Sweetened condensed milk is much used as an infant food, especially 
 among the lower classes. For very young children it is diluted to the 
 strength of one teaspoonful to four or five tablespoonfuls of water. Accord- 
 ing to J. Forster a child of four to five months of age ought to have daily 
 214 grammes of condensed milk, i.e. 7| ounces. This would (on an average) 
 contain as the daily food 21-3 grammes of proteid, 18"4 grammes of fat, and 
 98"2 grammes of carbohydrate, with about 5 grammes of salts. The pro- 
 portion of nitrogenous to non-nitrogenous foodstuffs is in this diet 1 to 5 "4, 
 which is a great deal too high. The amount of sugar is excessive and the 
 fat deficient. 
 
 Average Composition'^ (percentage) 
 
 - 
 
 Water 
 
 Alcohol 
 
 Lactic 
 acid 
 
 Carbonic 
 acid 
 
 Lactose 
 
 Proteid 
 
 Pat 
 
 Salts 
 
 Glycerine 
 
 Koumiss from 
 
 mare's milk . 90-44 
 Koumiss from 
 
 cow's mdlk . 89-20 
 K^phir . . 91-21 
 
 1-91 
 
 1-14 
 0-75 
 
 0-91 
 
 0-55 
 1-02 
 
 0-857 
 0-86 
 
 .1-77 
 
 4-09 
 2-4 
 
 2-24 
 
 2-66 
 3-49 
 
 1-46 
 
 1-83 
 1-44 
 
 0-22 
 
 0-43 
 0-68 
 
 0-16 
 
 Other preparations of milk are koumiss and kephir. These were both 
 originally prepared from mare's milk, by a peculiar process of bacterial fer- 
 mentation, in the Caucasus ; koumiss is, however, now made from cow's 
 
 > Konig, op. cit. 
 VOL. I. 
 
 2 From Konig, opi. cit. 
 F P 
 
434 EYGIENE 
 
 luilk as well. They both contain free carbonic acid and lactic acid, with 
 some alcohol. In kepliir the casein is partially changed into albumose and 
 peptone. Both preparations are used as food in phthisis and in cases of 
 vomiting. 
 
 Examination of Milk. Adultebations 
 
 Milk is so largely used as an article of diet, and so important a food not 
 only to the young but to adults, that a regular and good milk-supply to large 
 towns is largely mixed up with the well-being of the inhabitants. 
 
 Although the milk from different cows varies in composition, yet the ad- 
 mixture of the milk given by a herd averages the composition mthin certain 
 limits. In investigating the milk-supply from any particular locality it is 
 important to determine the number of cows in a herd, the age and race, the 
 kind of fodder, the health, and the time of milking. 
 
 A single cow will give on the average 9 to 14 litres of milk in the twenty- 
 four hours ; but the quantity may be less (in poorly-fed cows) or more (soon 
 after parturition). If the cow gives less than eight litres a day it is best not 
 to use the milk for consumption. Milk also ought not to be consumed until the 
 expiration of a fortnight after calving. The necessary regulations regarding 
 the animals on a dairy farm come under several headings. The fodder is 
 important. All those substances that impart a bad taste to the milk ought 
 to be withheld : such as brewers' wort, turnips, and decomposed food. 
 Carrots up to a certain quantity are allowable ; but the chief food ought to 
 be rape-seed cake, bran, corn, hay, and grass. A regular inspection of the 
 animals is necessary, to see the quantity of milk given by each cow, and to 
 investigate the health of the animals. The milk of sick and weakly animals 
 must be excluded, as well as that from animals with diseased udders — mas- 
 titis or tuberculosis. Strict cleanliness in the milking is necessary, and the 
 mixed milk of the herd is, with advantage, strained to remove gross impuri- 
 ties, or passed through two gravel filters of different coarseness, as is directed 
 by the Copenhagen Milk Supply Company. 
 
 Microscopical Examination. — Pure milk under the microscope shows a 
 great quantity of highly refractive oil globules floating in a clear hquid. 
 These oil globules are large, medium-sized, and minute ; they vary in diameter 
 between 0'017 millunetre and 0*01 millimetre. In old milk they are not so 
 well defined as in fresh milk.^ Colostrum (the first milk after delivery) has a 
 very different appearance under the microscope (fig. 87). It contains very 
 large oil-globules, some epithelial scales, granular matter, and, most cha- 
 racteristic of all, granular corpuscles, the largest of which are about 0-05 
 millimetre in diameter. Good milk may contain some of these corpuscles, but 
 they ought to be very few in number. The fat globules of milk are not dis- 
 solved by ether alone, but are completely soluble if milk is shaken up with 
 ether and potash. 
 
 Diseased milk sometimes shows abnormal constituents. Pus corpuscles 
 may be seen in abundance ; also red corpuscles. Bacteria may be seen with- 
 out the aid of staining ; but if the appearances are doubtful, they may be 
 stained for fifteen minutes with a 2 per cent, watery solution of methylene blue 
 after drying a drop of milk carefully on a cover-slip, wasliing off the excess 
 of colouring matter under the tap, and examining under the microscope after 
 mounting on a slide with a drop of water. If necessary the fat may be 
 removed from the dried specimen before staining by washing it with ether. 
 
 * Hilger, op. cit. 
 
FOOD 435 
 
 To decide the kind of bacteria present, cultivations must be made. Staining 
 in this way is also the best method for showing pus corpuscles. For 
 tubercle bacilli the cover-glass is prepared in the same way, and stained for 
 five minutes in warmed carbohc-fuchsin solution (Ziehl's solution] ; de- 
 colourised in 25 per cent, sulphuric acid, washed in water, stained with 
 methylene blue, washed again, dried, and mounted in Canada balsam. 
 Several preparations must be made. 
 
 Variations in the Composition of Milk 
 
 Specific gravity 1028-1034 
 
 Water 85-88 per cent. 
 
 Casein &c. (albumin, 0"05-4-5) . . . 2*5-5 „ 
 
 Fat 2-7-6 
 
 Lactose 3-5-6 „ 
 
 Salts 0-5-0-75 „ 
 
 Total solids 9-2-17-75 „ 
 
 On the average, however, the total solids should not be below 12 per cent. 
 
 Beaction of Milk. — Milk is normally alkahne (shghtly). London milk is 
 usually, however, slightly acid ; this is due either to change in the milk in 
 the milk ducts or after it has been drawn. Strong acidity means lactic or 
 butyric acid, the presence of which may be demonstrated by shaking the 
 milk with ether, which dissolves them ; the casein is usually coagulated in 
 such milks. Strong alkalinity may mean added sodium bicarbonate or 
 diseased milk. 
 
 Adulterations of Milk 
 
 1. Water may be added to the milk. 
 
 2. A common adulteration is removing part of the cream and adding 
 water to brmg the specific gravity up to the normal ; or removing the cream 
 from the evening milk and adding the morning milk. 
 
 3. Sodium bicarbonate, borax, boric acid, and salicyhc acid are added 
 to preserve. 
 
 4. Starch, flour, gum, dextrine may be added. 
 
 1. An excess of water may sometimes be detected by taking the specific 
 gravity. This is done by means of a lactometer (an accurate hydrometer), 
 and must be done at 15° 0. ; or, if at other temperatures, the result must be 
 corrected for 15° C. 
 
 In good milk the specific gravity is from . . . 1028-1034 
 In creamed milk the specific gravity is from . . 1033-1037 
 In half-creamed milk the specific gravity is from . 1031-1034 
 
 This method, however, has to be supplemented by the following methods 
 and by estimating the total sohds. 
 
 To estimate the total solids, take 10 grammes (weighed) of milk, add two 
 drops of acetic acid and 2 c.c. of alcohol, and evaporate to dryness in a water- 
 bath, afterwards keeping for some time at 105° C. The total sohds ought 
 not to be below 12 per cent. 
 
 2. The detection of deficiency in cream is the most important point in 
 the examination of milk. 
 
 The cream may be estimated in a cylindrical vessel, graduated in 100 
 parts (creamometer). Fresh milk is poured into the vessel up to the gradua- 
 tion, and kept for twenty-four hours at a temperature of 10°-15° C. The 
 cream floats on the top, and ought to measure 10-15 volumes per cent. In 
 half-creamed milk the amount is 5-6 volumes. The cream may be removed, 
 
 ff2 
 
436 
 
 HYGIENE 
 
 and the specific gravity of the underlying watery liquid (containing salts, 
 lactose, and casein) may be taken. The specific gravity ought to be 
 2-5°-3'5° higher than that of the whole milk. If less than 2-5° higher it 
 shows admixture of water (Hilger). 
 
 Fat in good milk ought not to be less than 3 per cent., and in creamed 
 milk not less than 1 per cent. 
 
 The amount of fat may be determined in the following manner : 
 Ten grammes (weighed) of milk are mixed with 20 grammes of burnt 
 gypsum, and evaporated to di-yness in a water-bath. The fat in the residue 
 is extracted by ether, and the ethereal solution after removal is evaporated, 
 and the residue dried at 105° C. and weighed. 
 
 3. Sugar is estimated by titrating with Fehling's solution ; 10 c.c. of 
 this solution is decomposed by O'OGTt) gramme lactose. 
 
 4. In the detection of starch, &c., 50 c.c. of milk is diluted with 200 c.c. 
 of water, heated, and alcohol is added to coagulate the proteid. The mixture 
 is then filtered, and the filtrate evaporated to half its bulk (or less). In this 
 filtrate great alkalinity usually means sodium bicarbonate. 
 
 Starch is shown by the blue colour with iodine ; and if starch is absent, 
 dextrine is indicated by the red colour with iodine. Gum is precipitated from 
 the filtrate by alcohol. Salicylic acid is shown by the violet colour on the 
 addition of perchloride of iron. 
 
 The serum-albumin may be estimated in the whey after clotting a mea- 
 sured portion of the milk by rennet, A measured quantity of the filtered 
 whey is precipitated by excess of alcohol, the precipitate collected, washed 
 with ether and alcohol, dried and weighed. 
 
 Milk Products : — Skimmed Milks ; Cream ; Butter 
 
 The cream may be removed from the milk by allowing the milk to stand, 
 or by the centrifugal machine. The liquid remaining is skimmed milk, and 
 is a useful article of food. The composition of these products is shown in 
 the following table : — 
 
 
 Composition in 
 
 LOO parts 
 
 
 
 
 - 
 
 Water 
 
 Proteids 
 
 Fat 
 
 Lactose 
 
 Salts 
 
 Lactic acid 
 
 Cream .... 
 
 Centrifugalised milk ' 
 SVimmed milk . 
 Buttermilk 
 Butter (English) 
 
 68-82 
 
 90-60 
 
 90-12 
 
 90-6 
 
 13-33 
 
 3-76 
 
 3-06 
 
 4-03 
 
 3-8 
 
 1-06 
 
 22-66 
 0-31 
 1-09 
 1-2 
 
 84-40 
 
 0-59-5-52 
 5-29 
 4-04 
 3-4 
 
 0-53 
 0-74 
 0-72 
 
 1-21 
 
 0-32 
 
 Cream varies in composition. 
 
 Specific gravity 1004-1025 
 
 Fat from 18-70 per cent. 
 
 Water „ 20-76 
 
 It is adulterated with albumin, starch, and sometimes other insoluble 
 substances. The methods of examination are the same as those for milk. 
 
 Cream may be utiHsed for feeding the child when the casein of milk 
 disagrees. According to Kehrer and Biedert (quoted by Spiegelberg 3), 125 c.c. 
 
 ' The composition of skimmed milk is closely similar to that of centrifugalised milk. 
 * Konig, quoted by Forster. Buttermilk varies greatly in composition : it often con- 
 tains much less fat (0-5 per cent.) and more lactic acid than in the analyses given. 
 s Op. at. p. 331. 
 
FOOD 437 
 
 of cream must be mixed with 375 c.c. of boiled water in which 15 
 grammes of milk-sugar have been dissolved. The proportion in English 
 measure is, cream one ounce, water three ounces, milk-sugar one drachm. 
 The mixture contains 1 per cent, of casein, about 6\ per cent, of fat, and about 
 4 per cent, of sugar ; if necessary, the amount of fat can be reduced. An 
 eighth of a litre (4^ ounces) is to be given every two hours. 
 
 Buttermilk and skim milk are useful articles of diet ; they may be thick- 
 ened with carbohydrate (starchy) food, and are serviceable in the dieting of 
 children and of dyspeptics. 
 
 An alkaloid, tyrotoxicon, may be present in decomposed cream and cause 
 serious symptoms of poisoning (Vaughan). 
 
 Butter 
 
 Butter, the fat of milk, is one of the most important articles of diet, being 
 ;an easily assimilated form of neutral fat. The well-to-do take a large part 
 of their fat in this way. It consists chiefly of neutral fats, mixed with water 
 and a small proportion of casein and salts (see above). These fats are the 
 glycerides of oleic, palmitic, and stearic acids, with smaller quantities of the 
 glycerides of myristic and butyric acids, and of the higher fatty acids, such as 
 caproic, caprylic, &c. When rancid it contains free fatty acids with the decom- 
 position products of glycerine (acrolein, &c.) and is apt to cause or to aggravate 
 the symptoms of acid dyspepsia. The average amount taken daily is about 
 :28 grammes (one ounce), which contains about 24 grammes of neutral fat, or 
 about two-fifths of the daily allowance of fat for an average man in moderate 
 work. 
 
 Variations in Composition. — The water in fresh butter is from 6 to 30 
 per cent., the fat 70 to 95 per cent., and the casein, lactose, and salts (which 
 may be reckoned together) from 0'9 to 6 per cent. 
 
 The greatest amount of water ought to be 12 per cent. ; quantities above 
 ithis represent water added to give weight. The casein, lactose, and salts 
 ought not to be more than 2 per cent., and the fat must be at least 86 per 
 ■cent. 
 
 In fresh butter the added chloride of sodium should not be more than 
 0*5 to 2 per cent. Strongly salted butter contains about 8 per cent, of added 
 salt, and 16 per cent, of water. Salt is almost absent from French butter, 
 ,and boric acid is added as a preservative. 
 
 Adulterations of Butter. — Butter is generally coloured by such substances 
 as saffron, curcuma, annatto, &c. No deleterious effect can, however, be 
 ascribed to these additions. 
 
 Insoluble substances may be added to give weight, such as potato- starch, 
 chalk, gypsum, and sometimes alum and free alkalies. 
 
 Foreign fats are the most important addition : tallow, lard, artificial 
 butter, palm oil, cocoa-nut oil, and rapeseed oil. 
 
 Method of Examination of Butter. — The smell and taste of butter are 
 characteristic. On saponifying with alkalies it gives the characteristic smeU 
 of the compound ether of butyric acid, which is not perceived if the product 
 saponified is artificial butter.^ , 
 
 The amount of water present in butter may be estimated by drying the 
 butter at 110° C, and weighing before and after. A very small quantity of 
 -water is suspicious of foreign fat (Angell, quoted by Parkes). 
 
 The amount of fat is estimated by dissolving it in ether, evaporating the 
 ether solution, drying and weighing. After dissolving the fat in ether, the 
 
 ' A. Hilger, Ziemssen's Handbuch der Hygiene, Th. 1, Abth. 1, 1882, p. 237. 
 
438 HYGIENE 
 
 residue consists of casein, lactose, and salts. The casein is estimated by wash- 
 ing the residue, drying, and weighing ; it ought not to be more than I'OG per 
 cent. 
 
 The added chloride of sodium is estimated by titrating with the standard 
 solution of silver nitrate, after solution of the fat in ether. 
 
 Detection of gross impurities in butter : starch, gypsum, sulphate of 
 barium, &c. 
 
 Hilger recommends the following method. To from five to ten grammes 
 of butter add twice the volume of water with a little alcohol, and keep the 
 mixture at the. melting pouit of the butter for a short time. The fat sepa- 
 rates from the watery substratum and may be removed. The watery layer 
 may contain in solution the added colouring matter, borax, free alkali, alum, 
 and sodium chloride, and traces of salicylic acid. The insoluble impurities 
 sink to the bottom, and may consist of starch, barium sulphate, chalk, &c. 
 The microscope detects the starch grains, as does a solution of iodine, and 
 chemical tests detect the other insoluble impurities. 
 
 Detection of the Admixture of Foreign i^a^s. —Foreign fats, chiefly animal, 
 such as beef and mutton fat and lard, are the most important adulterations- 
 of butter. 
 
 There are several methods for the detection of these impurities. 
 
 1. SjJeciflc gravity (Bell's method). 
 
 The fat is first melted at 100° F., and the specific gravity estimated by 
 weighing in a specific-gravity bottle. 
 
 The specific gravity of butter ought never to be below 910 ; as a rule it is 
 between 911 and 913 ; if adulterated butter, it is 902-904 ; if artificial butter, 
 it is 859 ; and if lard, beef fat, and mutton fat, it is 8G0-8G2. 
 
 2. Determination of the melting point of the fat. 
 
 The fat is first separated from the other constituents of the butter, and 
 the melting point determined by gradually heating the fat in a water-bath. 
 The following table of melting points is given by Hilger : — 
 
 Melting point 
 
 Butter (dehydrated) 30-8°-35°C. 
 
 Butter fat 32-5°-36'" 
 
 Lard , . 41°-42° 
 
 Beef fat 42°-44° 
 
 Mutton fat 47°-51° 
 
 Artificial butter 28°-31° 
 
 Palm oil 30°-44° 
 
 Cocoa fat 28°-35° 
 
 Parkes attached great importance to the determination of the melting 
 point, and variations from the average are sure indications of admixture of 
 foreign fats, especially beef fat and lard.^ 
 
 3. The microscope may indicate foreign fats by discovering crystals of 
 margaric and stearic acids. Pure butter shows only oil globules. The 
 microscopic tests require to be supplemented by the other tests mentioned,, 
 and by the following : — 
 
 4. Determination of the fixed {insoluble) fatty acids (Hehner).^ 
 
 This method is based on the fact that the fixed fatty acids obtainable 
 from butter differ in amount from those obtainable from other animal fats. 
 
 ' See Parkes's Pract. Hygiene, Tth ed., p. 307, where a useful table is given of the- 
 temperatures of fusion and solidification of different fats. 
 ■' Chem. News, 1877. 
 
FOOD 43a 
 
 From butter, 86'5-88 per cent, of fixed fatty acids is obtainable ; from other 
 animal fats, 95-28-95-8. 
 
 To 5 grammes of butter fat 50 c.c. of alcohol containing 2 grammes of 
 caustic potash (KHO) is added, by which the fat is saponified. The soaps 
 are dissolved in 150 to 200 c.c. of water and decomposed with hydric chloride. 
 The separated fatty acids are filtered and washed with two litres of boiling 
 water, and dried at 95° to 98°C. ; they are then weighed. 
 
 If the fixed fatty acids are over 90 per cent., there is admixture of foreign 
 fat in the butter. ^ 
 
 Artificial Butter — Margarine 
 
 Oleo-margarine was first manufactured by a process discovered by M6ge- 
 Mouries.^ Several products have since that time been sold under the name 
 of hutterine ; all such products are now by law (1887) directed to be called 
 margarine. Oleo-margarine is chiefly made from beef fat, from which most 
 of the stearin is removed ; the product is mixed with milk, and colouring and 
 flavouring compounds. Other ' margarines ' are made from beef fat, olive 
 oil, and milk, and others from tallow, lard, rapeseed oil, and palm oil.^ 
 
 They have not the characteristic smell of butter either when fresh or 
 when saponified. The fixed fatty acids obtainable from them are from 92 to 
 95 per cent. The average melting point is 28° C. to 31° C, and the average 
 composition is 8 to 15 per cent, of water, 80 to 92*5 per cent, of fat, and 5 to 
 6 per cent, of casein, colouring matter, and salts. 
 
 As an an article of food, margarine supplies to the poorer clases a cheaper 
 fat than butter, and, although not so assimilable, it is yet of great nutritive 
 value. 
 
 Cheese 
 
 Cheese is an important product of milk. It is made from milk simply, or 
 milk to which cream is added, or from milk with the cream for the most part 
 removed. Different kinds of cheese thus vary in composition, chiefly, how- 
 ever, in the amount of fat they contain. They all contain casein, fat, lactose, 
 salts (with in some cases added sodium chloride), and water ; but the organic 
 foodstuffs have during the ripening of cheese undergone decomposition, 
 chiefly the fat and casein, and to some extent the lactose ; so that cheese 
 contains free fatty acids, butyric, lactic, and some of the higher fatty acids. 
 Considered as a food, the smaller amount of free acids the cheese contains,, 
 the better is it. It also contains leucin, tyrosin, and ammonium salts. 
 They react either alkaline or acid to test paper. As an article of diet cheese 
 is very useful, since it contains a large quantity of proteid or fat in a con- 
 centrated form. But this concentration is from the point of view of digesti- 
 bihty a great drawback, since the harder the cheese is, the more difficult of 
 digestion is it, and remaining a long time in the stomach it sets up and 
 aggravates the symptoms of fermentative or acid dyspepsia. Some people, 
 too, even with healthy digestions, cannot eat cheese ; and this, taken with the 
 general indigestibility of the substance, makes the nutritive value of cheese 
 much smaller than would appear from its composition, and from experiments 
 with artificial digestion.* 
 
 Composition of Cheese. — This varies according to the milk from which 
 
 ' For Eeichart's method, whicli is an estimation (in terms of alkalinity) of the volatile 
 fatty acids obtainable from butter, see Zeits. Anal. Chem. 1879, p. 68, or Hilger, op. cit. 
 
 2 See Boudet, Bapp. fait au Conseil d'HygUne, etc., autoris. la Vente de la Margarine 
 Mourids. Paris, 1872. 
 
 ^ Cf. Hilger, op. cit. 
 
 * For an account of these see Konig, op. cit. p. 382. 
 
440 
 
 HYGIENE 
 
 the cheese is made, and according to the length of time during which the 
 cheese 'ripens.' 
 
 Cream cheese is made from cream or cream and milk. In it, therefore, 
 the fat is in greater proportion than the casein. 
 
 ' Fatty cheese ' is made from milk simply. 
 
 ' Half-fatty cheese ' is made from equal parts of skimmed milk (evening 
 milk allowed to stand twelve hours) and of morning milli. In it the fat is 
 about equal to the casein. 
 
 ' Lean cheese ' ^ is made from skimmed milk or partially skimmed milk. 
 The fat in it is much less than the casein. 
 
 Percentage Compo. 
 
 ^itioii of Cheeses 
 
 
 
 - 
 
 Water 
 
 Casein 
 
 Pat 
 
 Lactose, 
 &c. 
 
 Salts 
 
 Sodium 
 chloride.adJed 
 
 1. Cream cheese .... 
 
 2. Fatty cheese (such as Stilton, ^ 
 Cheddar, Gloucester, Gorgonzola, 
 Roquefort) ..... 
 
 3. Half -fatty cheese (Gruy^re, 
 Dutch) 
 
 4. Lean cheese (such as Parmesan) 
 
 30-66 
 
 380 
 
 39-79 
 31-80 
 
 2-84 
 
 25-35 
 
 29-67 
 41-19 
 
 62-99 
 
 30-25 
 
 23-92 
 19-52 
 
 2-03 
 
 1-43 
 1-79 
 
 ri8 
 
 1-15 
 
 4-97 
 
 4-73 
 6-31 
 
 2-37 
 1-97 
 
 Compared to medium fat beef, a fatty cheese contains 1*2 time more 
 proteid and 5*6 times more fat. 
 
 Bad Effects of Cheese. — Besides the effect on digestion above mentioned, 
 cheese, when it has become sour, may cause diarrhoea. The ptomaine, 
 tyrotoxicon, may also be developed and cause symptoms of poisoning. 
 
 Adulterations. — Starch is the commonest addition to give weight. It is 
 detected by the blue colour given with iodine. The fat may also be 
 removed with ether, so that the residue is easily examined microscopically 
 for starch grains and coarse additions. 
 
 Small quantities of copper, zinc, and lead may be found in the ash. 
 Arsenious acid may be found in the rind. 
 
 Cheese often becomes green and red, owing to the development of fungi ; 
 and an acarus (cheese-mite) commonly is found in old cheese. When 
 mouldy, cheese contains in large quantity the products of decomposition by 
 bacteria. 
 
 EGGS 
 
 Hens' eggs are the usual form in which eggs are eaten as food, but ducks' 
 eggs are also used, and on the sea-coast the eggs of sea-fowl. 
 
 Cmjqyositioii. — Hens' eggs vary greatly in size and in weight. Thus 
 small eggs weigh between 45 and 50 grammes, the medium-sized between 
 55 and 60 gi'ammes, and the large ones 70 grammes or over (Forster). The 
 average weight is about 58 grammes (two ounces). 
 
 The shell forms 10 per cent, of the weight ; it is relatively greater in the 
 smaller eggs than in the larger. The egg itself consists of two parts — the 
 white and the yolk in the proportion of 67 to 33. The white contains chiefly 
 albumin (egg-albumin), with a trace of fat and a small proportion of salts ; 
 the yolk contains a globulin (vitelHn) and a large quantity of fat and a larger 
 proportion of salts than the white. 
 
 ' The German terms ' Fettkase,' ' Halbfetterkase," Magerkase,' have been literally 
 translated to express these different kinds of cheese. 
 
 ^ Stilton is sometimes considered as a cream cheese, but in composition it belongs to 
 Class 2. 
 
FOOD 
 
 411 
 
 
 Composition c 
 
 )/ the Hell's 
 
 Egg (Konig) 
 
 
 - 
 
 Water 
 
 Proteid 
 
 Pat 
 
 Free extractions 
 
 Salts 
 
 Whole egg (less shell) . 
 White of egg . 
 Yolk of egg . 
 
 73-67 
 
 85-5 
 
 51-03 
 
 12-55 
 
 12-87 
 16-12 
 
 12-11 
 
 0-25 
 
 31-3'J 
 
 0-55 
 
 0-77 
 0-48 
 
 1-12 
 0-61 
 1-01 
 
 The yolk of ducks' eggs contains more fat than that of hens' eggs. The 
 fatty bodies of the yolk consist of the neutral fats — palmitin and olein, 
 cholesterin and lecithin. A small quantity of grape-sugar is also found, and 
 the most important mineral constituent present in the yolk is iron united 
 with an organic body. Potassium and phosphates are in excess in the salts 
 over sodium and chlorides. In the white, the sodium and chlorides are in 
 excess. 
 
 Ptomaines have been found in eggs (Gautier) and albumoses, but only 
 in very small quantities ; the presence of both these classes of bodies is to be 
 ascribed to incipient decomposition. 
 
 Digestibility of Eggs 
 
 According toEubner, with an egg diet most of the proteids are absorbed, 
 only about 3 per cent, of nitrogen being found in the faces (equal to about 
 20 per cent, proteid), while the fat is not so well absorbed, about 5 per cent, 
 appearing in the fasces. Eggs disagree with some people, and when in- 
 cipient decomposition is established ought not to be eaten. 
 
 Preservation of Eggs 
 Eggs are preserved by excluding air from entering through the shell. 
 This may be done by covering the shell with oil or gum, or with insoluble 
 lime compounds. Good eggs sink in a 10 per cent, solution of common 
 salt : bad ones float. 
 
 FLESH 
 
 The muscular tissue of various animals — chiefly herbivorous — and of fish 
 and of birds, forms one of the chief foods of adult man. Not only, however, is 
 the muscular tissue utilised, but also some of the internal organs, and some 
 invertebrate animals are also eaten. These will all be considered under the 
 heading of Flesh. 
 
 Meat 
 
 The flesh of many animals is eaten by man in different parts of the 
 world : but that chiefly used is obtained from the ox (beef), the calf (veal), 
 the sheep (mutton), the pig (pork), and the goat. The flesh of wild animals 
 (deer, &c.) is also eaten, but it is in civilised countries a luxury, and does not 
 enter into the dietary of the majority. 
 
 Composition 
 
 Flesh in the form of meat is a food containing many substances. It is 
 chiefly utihsed as a proteid, a fatty, or a saline food, the carbohydrate con- 
 stituents being in very small quantity. The chief proteid is myosin, which 
 exists in the muscle-fibre itself, and constitutes the greater part of the amoimt 
 ■of nitrogenous element mentioned in the table. It is a globuhn, soluble only 
 in saline solutions, and in dilute acids and alkalies, and is coagulated by a 
 lieat below 100° C. These properties show why it is not present in solution 
 in ordinary beef-tea. Myosin itself is the result of coagulation of the hving 
 muscle which occurs on its death — that is, on the onset of rigor mortis. The 
 
442 
 
 HYGIENE 
 
 meat is in this state hard. "When the rigor mortis passes off the meat be- 
 comes tender and is fit for cooking. 
 
 Other proteids present in meat are a small quantity of alkali- albumin,' 
 serum-albumin, and globulin derived from the blood ; gelatin formed in the 
 process of cooking from the connective tissue surrounding the fibres, the 
 vessels, and nerves, and a small quantity of elastin. The next most important 
 dietetic constituent of meat is the fat. This exists attached to the muscles 
 (part of the subcutaneous fat), but in well-fed and in fattened animals it is found 
 in the connective tissue between the muscle fibres ; meat may thus be spoken 
 of as fat, medium fat, and lean, and these three kinds have necessarily a 
 different dietetic value in considering a given dietary. The amount of fat in 
 the meat varies in diflerent kinds of beef, in mutton, and especially in pork, 
 which is thus rendered indigestible. The fiesh of young animals (calf and 
 lamb) is lean meat. 
 
 The fat itself solidifies after death and is composed of stearin, palmitin, 
 and olein in different proportions, the more solid fats containing an excess of 
 stearin (see p. 395). 
 
 The saline constituents of meat consist mainly of potassium and phos- 
 phoric acid; magnesium is in greater abundance than calcium. Sodium and 
 chlorine are in less quantity. This follows the general rule that the hquids 
 of the body contain sodium and chlorine in excess of potassium and phosphate, 
 while in the solid parts of the tissues the reverse holds good. In 1,000 parts 
 of the ash, there are 4-654 parts of KgO, 0-770 of Na,0, 0-086 of CaO, 0-412 
 of MgO, 0-057 of FeoOg, 4-644 of Podj, 0-672 of CI, and a trace of SO2. 
 
 Glycogen is the chief carbohydrate in meat ; it forms usually only 0-5 per 
 cent. After death it is mostly changed into grape-sugar. Inosit (muscle 
 sugar) is isomeric with grape-sugar ; it occurs in very small quantity. 
 The so-called extractives of meat are important, since they constitute 
 the stimulating principles of beef-tea and other broths. These are mostly 
 nitrogenous crystalline bodies derived from the proteid metabolism of the 
 muscle ; creatine and creatinine are the chief, but taurin, sarkine, xanthine^ 
 carnine, urea, and uric acid also occur to a less extent. 
 
 Sarcolactic acid is a product of the activity of muscles ; it is formed to 
 a great extent during rigor mortis. 
 
 - 
 
 Water 
 
 Nitrogenous 
 substances 
 
 Fat 
 
 N.-free 
 extractives 
 
 Ash 
 
 Proportion of 
 nit. to non- 
 nit, foodstuffs 
 
 Beef (very fat) 
 
 53-05 
 
 16-75 
 
 29-28 
 
 
 
 0-92 
 
 
 
 „ (medium fat) 
 
 72-03 
 
 20-96 
 
 5-41 
 
 0-46 
 
 1-14 
 
 1 : 0-28 
 
 ,, (lean) .... 
 
 76-37 
 
 20-71 
 
 1-74 
 
 — 
 
 1-18 
 
 — 
 
 Veal (fat) .... 
 
 72-31 
 
 18-88 
 
 7-41 
 
 0-07 
 
 1-33 
 
 — 
 
 ., (lean) .... 
 
 78-84 
 
 19-86 
 
 0-82 
 
 — 
 
 0-50 
 
 1 : 0-04 
 
 Mutton (very fat) . 
 
 53-31 
 
 16-62 
 
 28-61 
 
 0-54 
 
 0-93 
 
 — 
 
 „ (medium fat) . 
 
 75-99 
 
 17-11 
 
 5-77 
 
 — 
 
 1-33 
 
 1 : 0-33 
 
 Pork (fat) .... 
 
 47-40 
 
 14-54 
 
 37-34 
 
 — 
 
 0-72 
 
 1 : 2-57 
 
 (lean) .... 
 
 72-57 
 
 20-25 
 
 6-81 
 
 — 
 
 1-10 
 
 1 : 0-33 
 
 Horseflesh .... 
 
 74-27 
 
 21-71 
 
 2-55 
 
 0-46 
 
 1-01 
 
 1 : 014 
 
 Internal organa : 
 
 
 
 
 
 
 
 Tongue and heart 
 
 G5-66 
 
 19-61 
 
 13-75 
 
 0-10 
 
 0-88 
 
 1:0-7 
 
 Kidney''^ .... 
 
 76-58 
 
 16-64 
 
 5-56 
 
 0-10 
 
 1-12 
 
 1 : 0-34 
 
 Liver .... 
 
 71-39 
 
 19-7-2 
 
 5-55 
 
 1-69 
 
 1-65 
 
 1 : 0-36 
 
 The preceding table gives the percentage composition of different kinds of 
 meats (Konig). 
 
 ' This alkali-albumin is formed from the globulin of muscle when the tissue i» 
 alkaline. - Average of ox, sheep, and pig's kidney. 
 
FOOD 
 
 443 
 
 Meat is chiefly a proteid and fatty food. It is not to be deduced that the 
 amount of nitrogenous substances given in the above table is completely 
 available for assimilation. In other words, the 21 per cent, of nitrogenous 
 substances in beef does not consist solely of myosin and serum albumin, 
 which are of great nutritive value, but also of gelatin and elastin, the nutri- 
 tive values of which are not equal to that of myosin ; and of the nitrogenous 
 extractives, which are stimulants and are not proteid foods. Parkes gives the 
 total proteids of beef and mutton as 17 per cent., of which 13 per cent, are 
 useful, i.e. assimilable by the organism. Rubner, however, found that only 
 2"5 per cent, of the nitrogen taken in as proteid of meat was passed out in 
 the faeces. This reckons the percentage of proteids in meat as 20-90, of 
 which, therefore, 18"46 per cent, are available for the organism — a higher 
 reckoning than that given by Parkes. These experiments were done with 
 good meat. Meat as sold, however, contains gristle and bone, and Parkes's 
 figures may be taken as accurate for the proteid value of meat inclusive of 
 gristle but exclusive of bone. 
 
 Bone forms about 20-25 per cent, of the meat as sold. It is relatively 
 more in young animals ; in veal, for example, it forms as much as 30 per cent. 
 and over (Forster). Fattened and well-fed animals also possess relatively less 
 bone than the badly nourished. A well-nourished lamb has 5|- per cent, of 
 bone, a similar animal poorly fed over 8 per cent, of the weight during life 
 (Weiske). This proportion of bone is thus important, as the meat (inclusive 
 of bone) obtainable from differently nourished animals varies. 
 
 In thin oxen . 
 In medium-fed 
 In well-fed 
 In fattened pigs 
 
 53-60 per cent, of the life-weight is meat with bone 
 
 55-65 
 
 60-70 
 
 80-85 1 „ 
 
 A full-grown sheep weighs 60-90 lb. or more, and yields 60 per cent, of 
 available food ; a full-grown pig weighs 100-180 lb. or more, and yields 
 75-80 per cent, of available food. 
 
 The amount of fat in meat varies with the feeding of the animals. In a 
 fat ox it forms about one-third of the flesh, in a fattened pig about one-half 
 (Lawes and Gilbert). In thin and badly nourished animals, on the other 
 hand, the amount of fat may be reduced to 1*3 per cent of the meat, or even 
 lower (Siegert). 
 
 The fat of animals when separated varies slightly in composition in the 
 different animals. 
 
 Composition of Animal Fats (percentage) 
 
 - 
 
 Water 
 
 Membrane 
 
 Fat 
 
 Proteid 
 
 Salts 
 
 Mutton and beef suet 
 Pig's fat . 
 
 Lard ..... 
 Beef tallow 
 
 10-22 
 6-44 
 0-70 
 1-33 
 
 1-40 
 1-35 
 
 88-38 
 92-21 
 99-04 
 98-15 
 
 0-26 
 0-44 
 
 Traces 
 0-08 
 
 Artificial butter (margarine) is made from animal fats (see p. 439). 
 
 Variations in the Composition of Meat 
 These have been partly discussed above. The amount of bone varies, 
 but the greatest difference between meat from different animals is in the 
 amount of fat present. The flesh of young animals and of fish contains 
 more gelatin (when cooked) and less proteid than that of adult animals. 
 
 ' Forster, op. cit. p. 165. 
 
iU 
 
 HYGIENE 
 
 Digcstih'ilihj of Meat — CooMng 
 Both the preparation and the digestihiUty of meat have ah-eady been dig. 
 cussed (p. 422) ; also the preparation of soups, broths, &c. 
 
 Fish 
 
 Many varieties of fish are eaten as food ; both fresh and in the dried or 
 * cured ' state. As food, however, fish may be considered as divided into two 
 classes, the fatty and the non-fatty. Of the fatty, the salmon, herring, 
 and mackerel may be quoted as examples ; and of the non-fatty, the cod. 
 
 Percentage Composition of the Flesh of Fish 
 
 - 
 
 Water Protcid 
 
 Fat 
 
 Salts 
 
 Snilium 
 chloride 
 
 Proportion of 
 nit. to non- 
 nit. foodstufEs 
 
 Fat Fish : 
 
 Salmon (Salmo salar) 
 Herring {Clupea harencjns) 
 Mackerel (Scomber scombrtts) 
 
 Lean Fish : 
 
 Cod (Gadiis morrhua, var. 0. cala- 
 rias) ...... 
 
 Cured Fish : 
 Dried cod (unsalted) 
 
 „ (salted) .... 
 
 64-29 
 74-64 
 71-20 
 
 82-20 
 
 16-16 
 13-20 
 
 21-60 
 14-65 
 19-36 
 
 16-23 
 
 81-54 
 73-72 
 
 12-72 
 9-03 
 
 8-OB 
 
 0-33 
 
 0-74 
 3-37 
 
 1-39 
 
 1-78 
 1-36 
 
 1-36 
 
 1-56 
 9-92 
 
 4-74 
 
 1 : 0-59 
 1 : 0-61 
 1 : 0-41 
 
 1 : 0-02 
 
 Fish are preserved by smoking and salting. 
 
 Diseases Caused by Meat 
 
 Meat forming such a large proportion of the diet of man, it is evident that 
 a proper inspection of the meat sold with the view of the rejection of not only 
 unwholesome meat, but also of doubtful kinds, is extremely important to 
 the health of the community. (See article on Meat Inspection.) 
 
 1. Meat may undergo changes (putrefaction) after being prepared for the 
 market. It seems doubtful whether meat, healthy when prepared, can com- 
 municate acute infective diseases, after being exposed to contagion; but meat, 
 especially pork and ham, has been shown to be affected by micro-organisms, 
 which produce a specific diarrhoeal disease in man (p. 445). 
 
 2. It may also be affected by drugs which have been administered to the 
 animal, or by the peculiarity of its fodder. 
 
 3. It may be affected by disease of the cow ; and the proper investigation 
 of these kinds of diseased meat is of the highest importance. 
 
 1. Putrefactive Changes of Meat. — Healthybeef has a marbled appearance, 
 is of reddish colour, firm consistence, and gives a reddish juice on allowing it 
 to stand some time. The fat is firm, whitish yellow in colour, and does not 
 show any haemorrhagic spots. 
 
 In putrefaction the meat becomes of a less firm consistence, paler in colour, 
 and finally emits an offensive odour. The colour finally changes to a greenish 
 yellow, and parts of the meat are easily torn or become diffluent ; a knife 
 thrust into such meat smells offensively on being withdrawn ; the marrow 
 soon decomposes and becomes diffluent and offensive. The changes awe due 
 to the action of putrefactive bacteria, feeding on the proteid bodies which are 
 broken up with the production of, in many cases, crystalline products — the 
 eo-called cadaveric alkaloids or ptomaines.' 
 
 ' L. Brieger, ' JJeber Ptomaine,'' parts i. and ii. 1885 ; part iii. 1886. 
 
FOOD 445 
 
 From meat (beef and horseflesh) which has been allowed to decompose 
 in water at the temperature of the blood for five to six days, Brieger has 
 separated several alkaloids, neuridine, neurine, choline, and, most important of 
 all, an alkaloid apparently identical with muscarine, the active principle of 
 A.manita muscaria (Schmiedeberg and Koppe). This alkaloid produces the 
 following symptoms in animals : first, a great increase in the secretions — 
 salivation, nasal discharge, lachrymation, sweating, and diarrha3a — the respi- 
 ration is also quickened, becoming finally dyspnoeic, and with a large dose 
 asphyxial clonic spasms may be noticed. The cardiac beat is accelerated, the 
 blood-pressure sinks, and the heart finally stops in diastole. Similar 'muscarine- 
 like ' symptoms are produced by neurine and choline, although large doses 
 require to be administered. From decomposing horseflesh Brieger separated 
 a poison acting like curare — viz. paralysing the ends of the motor nerves. 
 From decomposing fish, Brieger has separated several alkaloids — trimethyl- 
 amine, methylamine, diethylamine, neuridine, cadaverine, putrescine. 
 Cadaverine and putrescine do not appear very poisonous unless injected into 
 the circulation, in which case they produce ' haemorrhages and ulcerations ' 
 very similar to those occurring in cholera. ^ They do not, however, cause 
 muscular cramps. There are probably other poisons in decomposing flesh, 
 not yet separated. It is important to notice that Brieger found the poisonous 
 effects of neurine, choline, and of muscarine (from decomposed meat) neutral- 
 ised by the administration of atropine. 
 
 The flesh of some animals which is not decomposed may be poisonous : 
 the common mussel, the sea-water mussel {Mytilus edulis] and some Crustacea 
 are sometimes poisonous. No definite poison has been separated from such 
 animals, with the exception of the sea-water mussel. In the outbreak of 
 mussel-poisoning occurring at Wilhelmshaven in Germany, the mussels were 
 found to contain a poisonous alkaloid — mytilotoxine — which produced the 
 symptoms of poisoning noticed in the persons who were affected. 
 
 The symptoms in man produced by the consumption of decomposed flesh are 
 chiefly confined to the gastro-intestinal tract, as shown in nausea, vomiting, 
 abdominal pain, and diarrhoea, sometimes choleraic in character. With these 
 signs, there is prostration and sometimes a rash on the skin of an urticarial 
 or erythematous character. Symptoms, however, may be altogther absent. 
 
 In a fatal outbreak of diarrhoea occcuring at Welbeck in 1880, Dr. Ballard 
 showed that the eating of ham was the cause, and (with Dr. Klein) demon- 
 strated that the disease was due to a specific bacillus. This micro-organism 
 also appeared to account for a similar outbreak of diarrhoea at Nottingham in 
 1881, which was also investigated by Dr. Ballard.^ 
 
 2. The peculiarity of the fodder may impart a disagreeable smell to the 
 meat, but actual poisonous properties transmitted from the fodder to the 
 flesh is more often observed in birds feeding on certain berries. Beef may 
 become poisonous by the cattle feeding on poisonous plants, delirium and the 
 symptoms of narcotic poisoning being observed when the meat is eaten by man. 
 
 Similarly the meat of cattle which have been dosed with arsenic and an- 
 timony previous to slaughtering may cause poisonous symptoms — vomiting, 
 diarrhoea, &c., when eaten, owing to the presence of the metal in the meat. 
 
 8. The most important question in regard to the deleteriousness of meat 
 is how far it is affected by disease of the animal. It is still doubtful to what 
 
 1 See Brieger, op. cit. Udranszky and Baumann, Zeits. f. Physiol. Chemie, xiii. 562. 
 For further information on ptomaines see Selmi, Sulla Ptomaine, &c. Bologna, 3 878 ; 
 ihid. 1882. Guareschi et Mosso, Les Ptomames, Turin, 1883. Gautier, Sur Us AlcaMdes 
 d6riv6s de la destniction bacterienne, &c. Paris, 1886. 
 
 * See Report of Medical Officer of Local Government Board, 1880. 
 
446 HYGIENE 
 
 extent the diseases of the animals used by civihsed man affect the meat so as to 
 render it unfit for consumption. Some facts are, however, definite, and will 
 now be discussed. 
 
 Disease of the animal may affect the meat in two ways : — 
 
 1. The meat may be infected with the young of worms. 
 
 2. It may be altered in composition by the general or local disease of the 
 animal, so as either to diminish the nutritive value of the meat or to render 
 it actually injurious. 
 
 Parasites {Animal) 
 
 a. The j^ig is infested with two parasites which are of importance to 
 man ; both these have their habitat in the flesh (pork) : the one, Cysticercus 
 celluloses, gives rise to the common tape-worm {Tcenia solium) in man, the 
 other, Trichina sinralis, gives rise to a disease in man, trichiniasis, which is 
 often fatal. 
 
 Cysticercus cellulosce maybe detected during life by examining the under 
 surface of the tongue ; if necessary, one of the vesicles may be removed for 
 microscopic examination. The parasite renders the flesh ' measly,' i.e. the 
 
 meat has scattered through its 
 substance small, round, whitish 
 yellow bodies. 
 
 A microscopical examina- 
 tion ought, however, to be 
 made. By digesting the meat 
 with pepsin and hydrochloric 
 acid for some hours at 40° C, 
 the bladders fill to the bottom 
 of the vessel, and may then 
 readily be examined (Schmidt 
 Fig. 90. Fig. 91. — Mulheim). The bladders 
 
 Cysticercus cellulosm, with head retracted (fig. 90), yary in size, and are COmpOSed 
 and extruded (fig. 91). (Leuckart.) ,. -xi t • n 7 j 
 
 of a sac. With liquid contents, 
 in which float calcareous and other particles. At one part the sac is pro- 
 longed into a head, which is crowned with booklets. These booklets are 
 diagnostic of cysticercus, and are not readily dissolved by hquor potassas. 
 The pork may therefore be heated for a few minutes with the caustic solu- 
 tion, when the bladders and numerous booklets will be set free if the 
 treatment be continued. 
 
 Cysticerci are killed by a temperature of 57°-60° C. (Lewis), and as the 
 temperature of well-cooked meat is about 65° C. such meat containing 
 cysticerci would be harmless if eaten. But no dependence can be placed on 
 the meat being so well done ; therefore, pork containing cysticerci ought 
 always to be condemned as food. Neither salting nor the ordinary smoking 
 kills the cysticerci. 
 
 Trichiniasis is a serious result of eating diseased pork when imperfectly 
 cooked, and after being made into sausages. The disease is rare in England, 
 but common in Germany. 
 
 Trichinised pork shows small white specks between the bundles of muscle 
 fibres ; these are the encapsuled worm (figs. 92 and 93). When eaten, the eggs 
 which are freed in the alimentary canal develop, and the embryos pass through 
 the walls of the gut, and migrate to the muscles and other parts. During 
 this migration they produce trichiniasis, which first appears some time after 
 the ingestion of the meat. Diarrhoea and loss of appetite are often noticed 
 first. Then there is a fever, with severe muscular pains and contractions. 
 
FOOD 
 
 447 
 
 weakness, and even coma. Death may occur within a few weeks. The early 
 symptoms sometimes resemble those of typhoid fever. 
 
 Trichinas, when free, are killed by a temperature of 63°-70° C, the 
 albumen becoming coagulated. Ordinary smoking does not destroy them, 
 nor does decomposition ; hot 
 smoking is fatal (Leuckart). 
 Trichinised fish is unfit for 
 food. 
 
 h. The cysticercus of beef 
 gives rise to Tcenia meclio- 
 canellata in man, a tape-worm 
 without hooklets, and with four 
 pigmented suckers. 
 
 c. In mutton, Cobbold de- 
 scribed a cysticercus which was 
 the young of Tce,nia tenella ; 
 very little is known about it. 
 The cysticercus has a double 
 crown of hooklets. 
 
 Flukes are common para- 
 sites in the liver of sheep ; they 
 are probably rendered com- 
 pletely innocuous by cooking. 
 
 Echinococcus disease aflects sheep and cattle in Iceland : it gives rise to 
 hydatid disease in man, the original infection coming from the adult worm 
 {Tcenia echinococcus), which is found in the dog. 
 
 The flesh of domestic animals (beef, mutton, pork) may contain oval 
 bodies from 3-^ to ^ inch in length, which are called Psorospermia or Eainey's 
 corpuscles. They are probably innocuous to man, but in pigs and sheep may 
 produce symptoms of illness. 
 
 Pig. 92. 
 
 Fig. 93. 
 
 Trichina spiralis in muscle fibre (Leuckart). 
 
 Meat of Diseased Animals 
 
 There is very little accurate knowledge as to the deleterious or non-dele- 
 terious character of the meat of animals affected with general diseases. In 
 some cases such meat has produced serious symptoms ; in other cases it is 
 harmless. The symptoms are chiefly those previously described or caused by 
 decomposed meat — viz. sickness and diarrhcea with prostration, and in some 
 cases fever. The poisons in the meat which prodiice these symptoms are not 
 known, and until further investigation has been made, it is impossible to say 
 whether they are alkaloidal, or whether they are produced from a trans- 
 formation (non-alkaloidal) of the proteids of the msat. 
 
 In many cases of disease the meat is pale and moist, and is altered in 
 consistency. It may also be tasteless. 
 
 The meat of cattle suffering from epidemic pleuro-pneumonia is considered 
 by some harmless, and a large quantity of such meat goes into consumption ; 
 that of those suffering from foot-and-mouth disease is also probably harmless. 
 Cattle plague is considered in Belgium to affect the meat dangerously ; cases, 
 however, where no harm has resulted from the consumption of such meat 
 are recorded. Small-pox in sheep injuriously affects the meat, which ought 
 not to be consumed. 
 
 Doubt exists as to the value of the meat of animals suffering from anthrax 
 and erysipelas carbunculosum. The organism in anthrax [Bacillus anthracis) 
 is rendered innocuous by exposure to a temperature of 55° C. (Toussaint). 
 
448 
 
 HYGIENE 
 
 T\\Q bacilli would therefore be destroyed in tlie cooking, and this result would 
 explain the harmless consumption of the meat in many cases. Infection 
 might, however, be produced by handling the uncooked meat if there were an 
 abrasion of the skin. Black-quarter (symptomatic anthrax, erysipelas carbun- 
 culosum) may cause the meat to be poisonous (Gamgee). 
 
 The question whether tuberculosis can be transmitted to man by meat is 
 an important one, which is not yet decided. It may safely be said, however, 
 that meat which contains tubercles in any stage, and in which tubercle bacilli 
 are found, ought to be condemned as unfit for human food ; and in London and 
 three towns in the British Isles lately (1889) this has been the magisterial 
 decision. Tubercles, however, are not commonly found in meat. The only 
 doubtful question is whether cows affected with tuberculosis (Perlsncht), but 
 in the meat of which there are no tubercle or tubercle bacilli, ought to be 
 allowed for human food — i.e. in cases where the disease is limited to the 
 internal organs. Such meat is often quite normal in appearance. At present 
 the question cannot be considered as settled. 
 
 Peesebvation of Meat — Peepabations 
 
 A common mode of preserving meat is by freezing, and in a frozen state it is 
 imported in large quantities from America and Australasia. Other modes are 
 drying, and in some cases powdering (forming the so-called ' meat powders '),, 
 and also smoking, during which process the meat becomes j)artly dried. 
 
 The chief defect of the preparations of beef, mutton, and veal is that they 
 are unsavoury, and do not cook well, and cannot for a long time be partaken of 
 with advantage. Such preparations are of chief use for soldiers and sailors 
 in time of war. 
 
 Many extracts of meat are now sold, some of which act as stimulants 
 (such as Liebig's Extract), and others are useful, both as stimulants and as 
 nitrogenous foods. The latter may be described as nitrogenous beef-teas. 
 
 In time of war, the mixtures of meat with vegetables, in the form of 
 sausages or concentrated soups, have been found of great use ; but owing 
 to want of the natural flavouring of the meat, the food soon causes loss of 
 appetite for it. Such preparations are those of mutton and rice, veal and 
 rice, smoked mutton and beans, German pea-sausage (Erbsivurst) made of 
 pea-flour and fat pork, with many others, chiefly Russian preparations.^ 
 
 The following table gives the composition of some of these preparations 
 of meats : — 
 
 Freparations of Meat, with and without added Vegetables (percentage Composition) 
 
 Carne pura (American dried beef, powdered) 
 Hassall's flour of meat (mixed with 8 per cent. 
 
 arrowroot, 8^ per cent, sugar, and 3 per cent. 
 
 salts and pepper, &c.) 
 
 Tinned meat ....... 
 
 German pea-sausage (Erhszuursi) (average) . 
 Ham (Westphalian) 
 
 Water 
 
 Proteids 
 
 Pat 
 
 N.-free 
 extrac- 
 tives 
 
 Ash 
 
 10-99 
 
 69-50 
 
 5-84 
 
 0-42 
 
 13-25 
 
 12-70 
 
 55-80 
 
 6-5.3 
 
 28-li 
 
 57-00 
 29-04 
 15-46 
 24-74 
 
 11-00 
 11-54 
 
 37-94 
 36-45 
 
 15-50 
 
 31-38 
 0-16 
 
 3-80 
 
 3-62 
 
 8-69 
 
 10-54 
 
 Many preparations (chiefly of beef) are now made by partially digesting the 
 meat, and drying more or less completely. The preparation is in some cases 
 mixed with carbohydrates. It will suffice to mention a few of these articles : 
 they are chiefly used for invalids. Darby's Fluid Meat, a liquid preparation, 
 
 ' Bee Konig, op. cit. i. 232 and 242. 
 
FOOD 449 
 
 contains 30"70 per cent, of peptone. It has an agreeable odour and aroma. 
 Carnrick's Beef Peptonoids is a dried powdered mixture of digested beef and 
 gluten and concentrated milk. It contains 56*62 per cent, of albumose (pro- 
 pepton), 7*11 per cent, of peptone,' with 5*5 per cent, of salts. Kemmerich's 
 Fleischpepton contains 14-56 per cent, of albumose and 32-57 per cent, of 
 peptone, while Koch's somewhat similar preparation contains 15"95 per cent, 
 of albumose and 18*83 per cent, of peptone. 
 
 Beef -tea is usually made from the skin or breast of beef, but the best kind 
 is made from beefsteak. In its preparation, the beef must be freed from 
 tendon and any excess of fat, and cut into small pieces. It is then covered 
 with cold water, salt added, and placed on the hob for two to three hours ; hot 
 water is added, and the mixture allowed to heat gently from one to one and a 
 half hours, the temperature never being raised to the boiling point. By this 
 means most of the salts and extractives are dissolved out of the meat, together 
 with some gelatine and fat. 
 
 Beef- tea is not a proteid food, since it contains only a trace of other proteid 
 besides gelatine ; most of the myosin is coagulated during the preparation, 
 and in order to utilise this myosin as food, it is best to take the ' dregs ' of 
 the beef-tea as well as the Uquid. Beef-tea is a salty food, containing the 
 sodium chloride from the blood and the interstitial liquid of the muscle, and 
 the potassium and phosphates from the muscle fibre itself (see p. 442). It is 
 also a stimulant to the nervous system, and a restorative of muscular energy. 
 These effects are ascribed to the extractives, and chiefly to creatine, which is 
 in larger amount than the other extractives. The mineral salts, however, may 
 participate in this stimulant effect. Soups made without the addition of 
 vegetables have a composition and action similar to that of beef- tea ; if bones 
 are used in their preparation, they contain more gelatine and salts than ordi- 
 nary beef-tea. 
 
 Liehig's Extract of Meat (Extractum Carnis) is prepared by freeing the 
 meat from fat and tendon, and applying a moderate heat ; the juice exuding is 
 the extract. Sufficient heat is not employed to change the collagen into 
 gelatine, so that the extract consists almost solely of salts and extractives, 
 creatin, and the other nitrogenous non-proteid bodies present in muscle. 
 Liebig's Extract is thus not a proteid food, but is a salty food, and a powerful 
 stimulant Uke beef-tea. It is a useful agent to restore mental or bodily activity. 
 
 Extractum Carnis is also made by pressure alone, without the appUcation of 
 heat. Many other preparations are in the market, concentrated forms of beef- 
 tea. They do not keep like Liebig's Extract, but they are more pleasant to take. 
 
 VEGETABLE FOODS 
 
 Articles of diet derived from the various parts of plants, seed, stem, root, 
 leaves, &c., have three chief functions to perform. First, they are the chief 
 source (in fact the only practical source) of the carbohydrate food of the 
 animal ; for although, as we have seen, glycogen is a constituent of meat and 
 of liver, it is in too small quantity to supply the needs of the economy : 
 therefore it is necessary to consume vegetable starches and sugars. Secondly, 
 they supply a large amount of salts to the body — phosphates, calcium, 
 magnesium, potassium, and iron, while sodium and chlorides are present in 
 deficient quantity, as has already been pomted out. Owing to the amount 
 of water they take up during cooking, they also supply a large quantity of 
 
 ' The analysis was performed before the recent researches of Kiihne and Chittenden on 
 albumoses; hence most of this peptone must be considered as albumose. The same 
 remark applies to other analyses of ' peptone ' preparations. 
 
 VOL. I. QQ 
 
450 HYGIENE 
 
 ■water to the organism. Uncooked fruits also perform this fmiction. Thirdly, 
 they are antiscorbutic. This action in this respect varies in the different 
 vegetable foods, and it is not known what particular constituent or con- 
 stituents possess the effect of preventing and of curing scurvy. This anti- 
 scorbutic action is of great importance in considering vegetable foods. 
 
 Stress has been laid under the iirst heading to the fact that vegetable 
 food is the chief source of the carbohydrate ingested. To a less extent they 
 are the source of proteid food. As we shall see, the Leguminosae are rich in 
 proteids, but, as has already been pointed out, the mixture of proteids, carbo- 
 hydrates, cellulose, and salts, present in the leguminous foods does not form 
 a combination in which the proteids are most easily assimilable by the 
 organism. The proteids of the cereals, and especially of wheaten flour when 
 made into bread, are not to be forgotten as of great importance. 
 
 Vegetable fats are of secondary importance as food. Most of the vegetable 
 foods contain but little fat, and this is not so digestible as animal fat. The 
 fatty vegetable foods (chiefly varieties of oats) are not in general use as foods 
 among civilised races. Olive oil (with its common adulteration, cotton-seed 
 oil) does not form an important constituent of dietaries. The fat of diets 
 is usually derived from animals — butter, &c. 
 
 Preparation of Vegetable Food.— The seeds of the cereals, and of some of 
 the Leguminoste after removing the outer coats, are ground into flours. The 
 advantages of this mode of preparation are plain. It removes a large quantity 
 of cellulose, which is not only indigestible, but prevents the complete digestion 
 and absorption of the foodstuffs, and it renders the food-article more easily 
 cooked and digested, owing to the fine division and the ease with which the 
 starch grains are acted upon by boiling water (see pp. 418 et seq.iov cooking and 
 digestibility of vegetable foods). During the process of milling there is a slight 
 loss in the percentage of proteid, and a greater loss of salts with a corre- 
 sponduig increase in the percentage of carbohydrates (see tables following). 
 In the case of wheaten flour, the better the milling, the less cellulose there 
 is present, and the less salts, while the whiteness of the flour increases, 
 although the colour to some extent depends on the natural colour of tlie 
 varieties of wheat. 
 
 Wheaten flour undergoes a further preparation into bread ; rye flour is 
 also made into bread ; millet and buckwheat yield an inferior kind of ' bread.' 
 
 General Composition of Vegetable Foods ; Characters of the Foodstuffs 
 
 1. Proteids. — The characters of the vegetable proteids have already been 
 partly discussed. The researches of Vines, the author, and others of late 
 years have tended to show that in the seeds of plants the two chief proteids 
 present are of the nature of a globulin and of albumoses. The legumin and 
 conglutin of leguminous seeds, Vines considers, are artificial products of the 
 action on the globulin of the dilute potash solution used in extracting. This 
 point is, however, not quite settled. Some of the vegetable proteids exist in 
 a crystalline form ; a crystalline form of vegetable vitellin has been described 
 by Maschka,^ Weyl, Schmiedeberg,^ and others. The aleurone grains found 
 in the cells of plants consist partly of crystalline proteids (Vines). It 
 may be pointed out again here that the nutritive value of the proteids of 
 leguminous seeds is probably equal to that of animal proteids (in meat, eggs, 
 &c.), as the experiments of Eutgers (previously quoted) and others have 
 
 ' Journ. prakt. Chem. Bd. Ixxiv. p. 43G. 
 
 - Zeit. fiir physiol. Chcmic, Bd. i. p. 205. See also Jcncrn. prakt. Chem. Bd. cxxxi. 
 pp. 105, 481. 
 
FOOD 451 
 
 shown ; but that the admixture with other foodstuffs and with cellulose found 
 in the seeds renders them less serviceable as proteid foods than meat from 
 animals. 
 
 The most important vegetable proteid is the gluten of wheat, owing to 
 the fact that bread is a universal article of diet and a necessity of ordinary 
 hfe. Gluten is not present in wheaten flour, but is formed from the globulin 
 and albumose present by the action of water.' It is composed of gluten 
 fibrin, derived from the globulin, and of insoluble albumose, derived^ from 
 the soluble form in the flour. This insoluble albumose probably corresponds 
 to Eitthausen's gluten-casein : the occurrence of this observer's gliadin and 
 mucedin was not confirmed by the author. Some of the reactions of gluten 
 are important from a dietetic point of view. Boiling water, for exa'rnple, 
 coagulates the gluten-fibrin and dissolves out part of the albumose ; while 
 uncoagulated gluten is completely soluble in dilute acids and alkalies, 
 although with some difficulty. This solubility, with its ready digestibihty 
 by pepsin-hydrochloric acid and by pancreatic juice, renders gluten a valuable 
 proteid food. Eye flour yields a gluten with water, but to a less extent than 
 wheaten flour, and it cannot be obtained readily by washing, like wheat-gluten. 
 
 2. Fats. — The fats of the vegetable foods in ordinary use are quite unim- 
 portant from a nutritive point of view, being present in small, and even 
 minute quantity. 
 
 3. Carbohydrates.— ^ioxckes, dextrines (gums), and sugars are found in 
 vegetable foods. In the seeds of cereals and Leguminosse the starch is the 
 <3hief carbohydrate, although dextrines and sugars are also present. In some 
 vegetable foods, sugar in the form of cane-sugar (sugar-cane, beet) or in the 
 form of glucose (various ripe fruits) is the only carbohydrate present in 
 quantity. Dextrine is usually present in small quantity with the starch (see 
 special section). The starches vary greatly in physical characteristics, in 
 the size, form, and structure of the starch grain. 
 
 Commercial Starches.— The average percentage composition of the starches 
 found in commerce is 16-04 of water, 1-18 of proteid, 0-06 of fat, 82-13 of 
 carbohydrate, 0-13 of cellulose, and 0-86 of salts. Of such an average com- 
 position are arrowroot, tapioca, sago, potato starch, and maize starch. 
 
 Arroioroot is obtained from different sources. The West Indian is obtained 
 from Maranta arundinacea, and is white and granulated in lumps. Forms 
 of arrowroot are also obtained from Curcuma, Jatropha Manihot (Eio 
 arrowroot, yielding tapioca), the arum (Portland sago), and Canna edulis 
 (Tous-les-mois). All these preparations of starch readily form a clear jelly 
 on cooling after heating with water. 
 
 The chief adulteration of true arrowroot (Maranta and Tous-les-mois) is 
 with potato, sago, and tapioca. 
 
 Tapioca is made from the pith of Jatropha Manihot (the cassava). It is 
 adulterated with potato starch, and sago. 
 
 Sago is obtained from the uaterior of the sago-palm {Sagus farinifera). 
 The commercial varieties are ' common ' or ' pearl.' The starch is soluble in 
 cold and hot water. 
 
 Potato starch is the usual adulteration. 
 
 Identification of the Starches by the Microscope 
 
 Adulterations of the starches by other varieties is detected best by the 
 microscope. Owing to the characteristic form of the starch granules in such 
 
 ' Weyl and Bischoff, Ber. d. deutscJi. Chem. Gesellsch. Bd. xiii. 1880, p. 367 ; Sidney 
 Martm, Brit. Med. Journal, II. 1886. 
 
 gg2 
 
452 
 
 HYGIENE 
 
 varieties, the adulteration of the pure starches just discussed or of the dif- 
 ferent flours may be detected. Wheaten flour, being the most important, is 
 the flour usually adulterated. 
 
 The structure of the starch grain has already been described (p. 422). 
 Each grain is laminated to a greater or less extent, and has a point round 
 which the laminfe are ranged ; this point, which is variously shaped, is the 
 hilum. The lamination, the position of the hilum, the shape of the grain, 
 the character of the contour, and the size all serve in the identification of 
 the varieties. 
 
 Starch grains may be divided into two groups: (1) a group in which 
 the contour is even, containing potato starch, most of the varieties of arrow- 
 root, beau, pea, wheat, barley, and rye starch ; (2) a group in which the con- 
 tour is facetted either partially, as in sago and tapioca, or completely, as in 
 rice, maize, and oats. 
 
 1. Starch Grains with even Contour. — (a) Potato starch may be taken 
 as the type. The largest grains average 0-0G52 millimetre in the longest 
 diameter ; the smaller grains 0'024; millimetre.' The grains are pyriform 
 in shape, with an eccentric hilum (at the small end of the grain), and the 
 lamination is well marked (see fig. O-l).- 
 
 (b) Bermuda Arroivroot. — Large grains, 0*044 millimetre ; medium-sized 
 grains, 0*02 millimetre ; and smallest grains, 0*012 millimetre in the longest 
 diameter. 
 
 Fig. 94. — Potato starch. 
 
 Fig. 95. — Bermuda arrowroot Fig. 96. — St. Vincent arrowroot 
 starch. starch. 
 
 The grains are ovoid, with the hilum at the larger end, the hilum being 
 a dot, a slit, or crucial (see fig. 95). The lamination is well marked. The 
 grain is frequently beaked. 
 
 St. Vincent Arroioroot. — Large grains, 0"04o6 millimetre ; medium-sized, 
 0'028 ; and smallest, 0"012. The grains have the same character as those of 
 Bermuda arrowroot, and it is almost impossible to distinguish them (see 
 fig. 96). 
 
 Tous-les-Mois arroivroot has grains like potato starch, but they are 
 much larger. The hilum at the smaller end of the grain distinguishes tous- 
 les-mois from Bermuda and St. Vincent arrowroot. 
 
 Curcuma arroivroot has large oblong grains, well laminated ; the hilum 
 is at the smaller end of the grain. 
 
 (c) The grains of beans and 2y^tts are oval or reniform, with a longitudinal 
 hilum, which is irregvilar in bean starch, but more regular in pea starch. 
 Lamination is indistinct. 
 
 Pea-starch grains {Pisum sativum), largest grains, 0*044 millimetre in 
 longest diameter ; medium-sized grains, 0'028 millimetre ; and smallest, 0*01 
 millimetre (fig. 97). 
 
 ' These measurements are the average of 5 to 10 grains ; they give a good idea of the 
 difference of size of grains in the different starches. The measurements are in all cases of 
 the longest diameter. 
 
 - All the figures are drawn under the magnifying power of Hartnack, Oc. 7, Obj. .3. 
 
FOOD 
 
 453 
 
 Bean-starch grains (haricot bean, Phaseohis vulgaris). Average longest 
 ■diameter, 0*044 millimetre (fig. 98). 
 
 (d) The starch grains of loheat and barley cannot be distinguished under 
 the microscope ; barley, however, contains many medium-sized grains, while 
 wheat contains only large and very small grains (see figs. 99 and 100). 
 
 Pig. 97.— Pea starch. 
 
 Fig. 98. — Bean starch {Phaseolus 
 vulgaris). 
 
 The grains are round and oval, Avith a central hilum, slit-like, and some- 
 times star-shaped in the wheat (see fig. 100). Lamination is very faint. 
 
 Wheat Starch Grains. — Lai-gest, 0-032 millimetre in longest diameter ; 
 smallest, 0-004 to 0-008 millimetre. 
 
 
 Pig. 100.— Wheat starch. 
 
 Pig. 99.— Barley starch. 
 
 Pig. 101. — Rye starch. 
 a, crushed grain. 
 
 0-02 
 
 Barley Starch Grains. — Largest, 0-03 millimetre ; medium-sized, 
 smallest, 0-004 to 0-008 millimetre in longest diameter. 
 
 The starch grains of rye are very similar to those of wheat and barley ; 
 the contour is, however, spherical, and the hilum frequently star-shaped (see 
 fig. 101), especially in the largest grains. The smallest grains are 0-004 
 millimetre in diameter. The medium-sized are 0-02 milhmetre, and the 
 largest, 0*04 miUimetre in diameter. The presence of these large grains with 
 
 Pig. 102.— Sago starch. 
 
 Pig. 103. — Tapioca starch. 
 
 star-shaped hilus distmguishes rye from barley ; the presence of numerous 
 medium-sized grains and of many grains with star-shaped hilus distinguishes 
 rye from wheat. 
 
 2. Starch Grains ivith a facetted Contotor.— In sago and tapioca, the grains 
 are partially facetted (see figs. 102 and 103). The grains of sago are large, the 
 
454 
 
 HYGIENE 
 
 hilmn often cavernous, and there is a liollow in the centre of the grain. 
 Lamination is imperfect and irregular, bize of largest grains, 0'059 milli- 
 metre ; medium -sized, 0-082 millimetre in the longest diameter. 
 
 Tapioca is only to be distinguished from sago by the size of the starch 
 grains ; these are about one-third the size of the largest grains of sago, i.e. 
 about 0-022 millimetre in the longest diameter (fig. 108). 
 
 The starch grains of maize, oats, and rice are completely facetted, and are 
 readily distinguished under the microscope. The points they have in common 
 are that they are completely facetted, and that lamination is very indistinct 
 or absent. In maize the facets are the most perfect, the grain being like a 
 disc or half a tetrahedron ; the hilum is distinct, stellate, sometimes a 
 mere dot, sometimes cavernous (see fig. 104). The diameter of the grains 
 averages 0-028 millimetre. 
 
 In rice (fig. 105) and oats the grains are very small, in the former 0*006 
 milhmetro in diameter, in the latter twice the size, viz. 0-012 millimetre. 
 
 Fig. 104. — Maize starch 
 (Indian com). 
 
 Fig. 105. — Eice starch. 
 
 Fig. 100.— Oat starch. 
 
 Apart from the size, oat- starch grains are readily distinguished from rice by 
 their aggregation into spherical clumps (see fig. 106). They are both dis- 
 tinguished from maize by the size of the grain, and by the fact that in very 
 few grains of oat and rice starch can a hilum be seen. 
 
 Sugars. — The two chief varieties of sugar found in commerce are cane- 
 sugar from the sugar-cane {Saccharum officinarum), and beet-sugar from 
 Beta vulgaris. 
 
 White cane-sugar contains, in 100 parts, 98-38 parts of saccharose, 1-78 
 of dextrose, 0-85 of proteid, 0-30 of gum and vegetable acids, O'Ql of ex- 
 tractives, 0-76 of salts, and 2-16 of water. 
 
 Beet-sugar contains, in 100 parts, 94-42 parts of saccharose, 0-21 of invert- 
 sugar, 3-44 of various substances, and 1-93 of water. 
 
 The colour of brown sugar is due to invert-sugar, of which there is 4-5 
 per cent, present. Brown sugar also contains more water than white ; on 
 the average 4-6 per cent, is present, but as much as 10 per cent, may be 
 found in coarse brown sugar. 
 
 Honey dijffers from ordinary sugar in containing more invert-sugar 
 (dextrose and lasvulose) than saccharose. The composition varies greatly, 
 but on an average, in 100 parts, there are 72-88 parts of invert-sugar 
 (consisting of 38-65 lacculose and 84-48 dextrose), 1-76 of saccharose, 0-22 
 of dextrine, 0-71 of wax, 0-76 of proteid, 2-82 of non-saccharine sub- 
 stances, 0-25 of ash, 0-028 of phosphoric acid, and 20-60 parts of water. The 
 total invert-sugar may be as low as 64-10 per cent., and as high as 79-37 
 per cent. Lsevulose is, however, always in greater proportion than 
 dextrose. 
 
 Honey is adulterated with cane-sugar, with sugar made from starch, and 
 with inert matter. . 
 
 Salts. — These will be considered under the special headings of foods. 
 As has already been pointed out, potassium and phosphates are in excess 
 
FOOD 4^5 
 
 over sodium and chlorides, showing the necessity of common salt to vege- 
 table feeders. Iron is an important constituent of the salts of vegetable 
 foods ; in white wheat, for example, phosphate of iron forms 0-3 1 per cent, 
 of the ash, while in the Peruvian quinoa seeds it is present in the proportion 
 of 0*75 of the whole seed (quoted by Parkes ^). 
 
 A rough but useful classification of vegetable foods may be made accord- 
 ing as the organic foodstuffs or the inorganic are the chief constituents 
 present. 
 
 1. In one class, for example, there are the food grains, including the 
 cereals, in which the proteids are present in the proportion of about 10 per 
 cent., while the carbohydrates are from 65 to 70 per cent. These foods are 
 chiefly carbohydrate foods, to a less extent proteid foods. Edible chestnuts 
 also belong to this class. 
 
 2. In another class the seeds of Leguminosae are included. In these the 
 proteids are from 20 to 25 per cent, (sometimes over 30 per cent, in Soja 
 beans), while the carbohydrates are from 46 to 69 per cent. This class then 
 includes vegetable products which are eminently proteid, as loell as carbo- 
 hydrate foods. 
 
 3. A third class contains members, such as the potato, in which the pro- 
 teid is insignificant in quantity, Avhile the carbohydrates are fairly abundant 
 (20 per cent.) To this class would pre-eminently belong the commercial pre- 
 parations of starch, such as arrowroot, tapioca, and sago. 
 
 4. Some vegetables, as the beet and ripe fruits, are also carbohydrate 
 foods ; but they have a more important function than this to perform, viz. 
 that of supplying vegetable acids and salts to the organism. In this way 
 foods, such as cabbage, turnips, carrots, &c., act as antiscorbutics. 
 
 CLASS I. THE CEREALS 
 
 The cereals belong to the first class of vegetable foods, those which are 
 chiefly serviceable as yielding carbohydrates, while to a less extent they are 
 proteid foods. 
 
 To the cereals belong wheat, barley, oats, rice, rye, maize, and millet. 
 Buckwheat may also be included. By far the most important of these is 
 wheat, as yielding bread, but in some countries other cereals are also of 
 great importance — in Scotland oats, in India rice and millet, and in the 
 Spanish- speaking countries of America maize-cakes take the place of bread, 
 which is almost unknown. 
 
 The preparation which these grains undergo and the effect it has on the 
 percentage composition have already been discussed (p. 450). This effect is 
 evident by referring to the tables following. Bread is made chiefly from 
 wheaten flour, but inferior kinds are also made from rye, millet, and buck- 
 wheat. 
 
 Wheat {Triticum vulgare et sp. var.) 
 
 The wheat grain is surrounded by four coats, the outermost of which is 
 cuticular and hairy ; the next coat is composed of rounded cells ; the third 
 coat is almost hyaline ; and the internal coat is also very thin. The second 
 coat is the only conspicuous one. Within the innermost coat is the wheat 
 
 ' Hygiene, p. 286. 
 
456 
 
 HYGIENE 
 
 grain proper, which contains the starch, fat, proteid, and salts of the flour. 
 In the process of miUing the coats are removed as far as possible, being 
 separated as bran ; in the so-called wholemeal the whole grain is milled. 
 
 Percentage Composition of Cereal Grains and of Flours 
 
 
 
 
 
 Carbo- 
 
 
 
 Proportion of 
 
 
 
 Water 
 
 Proteid 
 
 Fat 
 
 Cellulose 
 
 Ash 
 
 nit. to non- 
 
 
 
 
 
 hydrates 
 
 
 
 nit, foolstufl'p 
 
 1. Wheat : 
 
 
 
 
 
 
 
 
 Grain (average of 948 
 
 
 
 
 
 
 
 
 analyses of all countries) 
 
 13-37 
 
 12-04 
 
 1-85 
 
 68-65 
 
 2-31 
 
 1-78 
 
 — 
 
 Flour, fine 
 
 13-37 
 
 10-21 
 
 0-94 
 
 74-71 
 
 0-29 
 
 0-48 
 
 1 :7-4 
 
 „ coarse . 
 
 12-81 
 
 12-06 
 
 1-36 
 
 71-83' 
 
 0-98 
 
 0-96 
 
 1 : 5-98 
 
 „ wholemeal (At- 
 
 
 
 
 
 
 
 
 water) 
 
 13-00 
 
 11-70 
 
 1-70 
 
 69-90 
 
 1-90 
 
 1-80 
 
 1 :6-l 
 
 2. Barley: 
 
 
 
 
 
 
 
 
 Grain (shelled, average) . 
 
 14-05 
 
 9-66 
 
 1-93 
 
 66-99 
 
 4-95 
 
 2-42 
 
 — 
 
 Flour .... 
 
 14-83 
 
 11-38 
 
 1-53 
 
 71-22- 
 
 0-45 
 
 0-59 
 
 1 : 6-4 
 
 3. Oats: 
 
 
 
 
 
 
 
 
 Grain (shelleil) 
 
 12-11 
 
 10-66 
 
 4-99 
 
 58-37 
 
 10-58 
 
 3-29 
 
 — 
 
 Meal (line) 
 
 9-65 
 
 13-44 
 
 5-92 
 
 67-01^ 
 
 1-86 
 
 2-12 
 
 1 :5-4 
 
 4. Eice: 
 
 
 
 
 
 
 
 
 Shelled .... 
 
 12-58 
 
 6-73 
 
 0-88 
 
 78-48' 
 
 0-51 
 
 0-82 
 
 1 : 11-8 
 
 5. Hte : 
 
 
 
 
 
 
 
 
 Grain (shelled, average) 
 
 13-37 
 
 10-81 
 
 1-77 
 
 70-21 
 
 1-78 
 
 2-06 
 
 — 
 
 „ German 
 
 13-37 
 
 11-52 
 
 1-84 
 
 68-88 
 
 2-45 
 
 l-'.)4 
 
 — 
 
 Flour .... 
 
 13-71 
 
 11-57 
 
 2-08 
 
 69-61^ 
 
 1-59 
 
 1-44 
 
 1 : 6-2 
 
 6. Maize (Indian corn) : 
 
 
 
 
 
 
 
 
 Grain (average) 
 
 13-35 
 
 9-45 
 
 4-29 
 
 69-33 
 
 2-29 
 
 1-29 
 
 — 
 
 Meal .... 
 
 14-21 
 
 9-65 
 
 3-80 
 
 69-55 
 
 1-46 
 
 1-33 
 
 1 :7-6 
 
 (For Millet and Buckwheat see p. 468.) 
 
 Wheateii flour, as just stated, is of two kinds, the one ordinarily used 
 being white, the other, wholemeal, being of a dark colour, owing to the ad- 
 mixture of bran. 
 
 In the market there are several varieties, according to the completeness 
 of the milling — separation of the coats and grinding of the grain. The most 
 highly milled flours are the whitest, and contain least bran and least cellu- 
 lose ; as has been pointed out, they lose in the process some proteid and 
 some salts, but this loss is more than compensated for by the fineness of the 
 bread prepared from it. The chief flours in the market are in the order of 
 their excellence (fineness and whiteness), Vienna whites, best whites, best 
 households, second households, and other flours inferior in quality. There 
 are also brown meal and whole meal. 
 
 We have already stated that the two proteids present in flour are a 
 globulin and an albumose, and that gluten is formed from these by the action 
 of water. All the globulin and albumose is not transformed into gluten — 
 some remains dissolved in the water with which the flour is washed." For 
 the proportion of gluten see p. 4G1. 
 
 The amount of gluten obtainable is a test of the quality of the flour as 
 regards proteid and its capacity for making bread. In bad wheat (due to 
 bad seasons, &c.) very little gluten may be obtainable from the flour, the 
 
 ' The carbohydrates are composed of starch 66-28 per cent., dextrine 4-00 per cent., and 
 BUgar 1-86 per cent. 
 
 ' Composed of starch 61-59 per cent., dextrine 6-52, and sugar 3-11 per cent. 
 
 ^ Starch 59-39 per cent., dextrine 3-08 per cent., sugar 2-26 per cent. 
 
 * A small proportion of dextrine and a trace of sugar (Pillitz). 
 
 ' Starch 58-61 per cent., dextrine 7-16 per cent., sugar 3-80 per cent. 
 
 •^ This is often erroneously referred to as ' albumen ' in works on food, and gluten is 
 6poken of as a constituent of flour. 
 
FOOD 
 
 457 
 
 proteids being in the form of ' soluble albuminoids,' as they are often called, 
 and thus remain dissolved in the water used in washing the flour without 
 yielding gluten. The better the flour the less the ' soluble albuminoids ' 
 yielded by water (see Examination of Flouk, p. 4G1). Why they should not 
 form gluten is not known, any more than why barley, which, according to my 
 researches, contains proteids of the same character as wheat, should not yield 
 gluten at all. Some wheats (called hard) yield much gluten ; from such 
 macaroni is made. Soft wheats contain less gluten than the hard, and more 
 starch. The starch presents the characters previously mentioned (p. 453). 
 Some dextrine and sugar are also present (Table, p. 456). The salts consist 
 chiefly of phosphates and potassium and magnesium. 
 
 Percentage Composition of Wheat-grain Ash • 
 
 Lawes and Gilbert Way and Ogston 
 
 Phosphoric acid . 
 Phosphate of iron 
 Potash . 
 Soda . 
 Magnesia 
 Lime . 
 Sulphuric acid 
 Carbonic acid 
 Chlorine 
 Silica, &c. . 
 
 Total 
 
 49-68 
 
 45-01 
 
 2-36 
 
 0-82 
 
 29-35 
 
 31-44 
 
 1-12 
 
 2-71 
 
 10-70 
 
 12-36 
 
 3-40 
 
 3-52 
 
 
 
 0-34 
 
 
 
 0-02 
 
 0-13 
 
 0-13 
 
 2-47 
 
 3-67 
 
 99-21 
 
 100-02 
 
 Wheat as a Food. — In fine flour the proportion of nitrogenous to non- 
 nitrogenous organic foodstuffs is as 1 to 7-4 ; the proteids are therefore 
 deficient. Wheat is therefore chiefly a carbohydrate food, although the pro- 
 teid constituents are very nutritious. When made into bread it is a food 
 which may be eaten for any length of time, since it never cloys ; but, as seen 
 from what has been said, it is deficient in two foodstuff's — fat and common 
 salt. The addition of salt to the bread (in the making) and the eating with 
 butter are two empirical discoveries of mankind which have a very rational 
 basis. ' Brown. ' bread is made from white flour (often not of the best) mixed 
 with varying proportions of bran. It is far below white bread as a food, 
 owing to the admixture of coarse bran and its aperient action. 
 
 Of late years it has been proposed to include the whole of the wheaten 
 grain in the making of bread, wholemeal yielding Avholemeal bread. The 
 advantages claimed for this process are that the bread is thereby rendered 
 more nutritious ; there are more proteid foodstuffs and more salts in the 
 bread. The exact gain depends, of course, on the quahty of the wheat 
 originally used. If we take bran as forming 16 parts of the grain, we have 
 an addition of, on the average, 0-7 per cent, of proteid, and 0"16 per cent, of 
 salts. The disadvantages of wholemeal bread are first its dark colour, and 
 the fact that the gain in proteid and salts is accompanied by an admixture 
 of cellulose. This indigestible cellulose, whether the flour is finely milled 
 or not, is not only an irritant to the intestines (as shown by its stimulating 
 peristalsis), and especially so in disease of the alimentary tract, but it 
 also diminishes the absorption of the digestible foodstuffs ; a fact which has 
 already been insisted upon. These effects of cellulose more than counter- 
 balance the gain in proteid and salts. Salts in abundance are obtained from 
 
 ' Quoted by Dr. C. Graham, ' Chemistry of Bread-making,' lecture at the Health 
 Exhibition, 1884. 
 
458 HYGIENE 
 
 many foods besides flour, and bread is not, as has been stated, a pre-eminently 
 proteid food. It seems wiser, tberefore, to adhere to the tradition of centuries., 
 and finely mill the grain so as to obtain white flour and white bread. 
 
 Preparations of Wheaten Flour 
 Of the preparations of flour, bread is the most important : of less import- 
 ance are biscuits, macaroni, and vermicelli. 
 
 1. Bread 
 
 The best bread is made from white wheaten flour. In times of famine or 
 war other starchy foods are added to the flour, to make up the weight of the 
 loaf ; these starchy foods are rice, barley, oats, rye, maize, millet, peas, and 
 buckwheat. Under ordinary conditions, these additions are regarded as 
 adulterations, under which heading they will be considered (p. 4G1). 
 
 The processes for making bread are various. The first process, the origin 
 of which is hidden in prehistoric times, consisted in simply mixing the flour 
 with water, and baking. This process is still used in Spain, in India (making 
 ' chupatty ' ), and in Austraha ( making ' damper ') ; leaven was then discovered, 
 and is now used in some countries in the North of Europe. Leaven is dough, 
 with or without an admixture of salt and boiled potatoes, allowed to stand 
 exposed to the air, until decomposition commences. This decomposition is 
 produced by a ferment action on the starch, whereby alcohol and carbonic acid 
 gas are formed. The leaven acts the part of the ferment (presently to be 
 described) in the ordinary making of bread. The modern process of bread- 
 making consists in the use of yeast as a ferment. 
 
 (a) Bread-making by Means of Yeast. — The London system is a long 
 process with three stages : ' — 
 
 1. The preparation of the 'ferment.' 
 
 2. The preparation of the ' sponge.' 
 
 3. The preparation of the ' dough.' 
 
 One sack of flour Aveiglis 280 lb., and 94 to 9G quartern (4 lb.) loaves may 
 be obtained from it ; in other words, 280 lb. of flour yield o7G to 384 lb. of 
 bread. The following remarks apply to a sack of flour. 
 
 1. The ' ferment ' is made with 8 to 12 lb. of the best potatoes, cleaned, cut 
 up, boiled, and made into a thin paste ; the temperature of the mixture is 
 then reduced by cold water to about 30° C. (86° F.) To it 2 lb. of flour are 
 added and one quart of brewer's yeast. The process which takes place in 
 this mixture of potato starch, flour, and yeast is that the yeast decomposes the 
 proteids of the flour and the starch of the potato, forming maltose, dextrine, 
 and peptone-like bodies. The process is continued for five hours. The yeast 
 becomes very active with the sugar and proteid food. 
 
 2. The ' sponge ' is made by mixing one-fouitli or one -third of the total 
 quantity of flour into the ' ferment,' the water present being about 30 
 quarts. Three pounds (48 oz.) of salt are then added. With the best flours 
 the salt is not necessary. If too much be used, fermentation is checked. The 
 chemical process going on in the sponge stage is one of active fermentation ; 
 in about five hours the sponge breaks, owing to the development of carbonic 
 acid, i.e. the fermentation has gone a step further than the first stage ; from 
 the maltose and dextrine carbonic acid and alcohol are formed. The sponge 
 is allowed to break a second time. 
 
 8. The remainder of the flour of the sack (three-fourths or two-thirds) 
 
 ' See lecture, ' Chemistry of Bread-making,' by Dr. Charles Graham, previously quoted,, 
 to which lecture I am indebted for the facts stated. 
 
FOOD 4u9' 
 
 with the remainder of the water (60 quarts to the sack) are now mixed with 
 the sponge and the dough is formed. It rises in an hour, and is placed in an 
 oven at 400 to 450° F. (204° to 282° C.) for an hour and a half. The tempe- 
 rature of the dough itself is not much over 100° C. The chemical processes in 
 the dough stage are not very active ; the high temperature stops the fermen- 
 tation. But it is during this stage that the bread becomes well aerated, and 
 that the aroma and flavour of the loaf are developed. Both these are very 
 important points, and are useful in aiding digestion. The fine aroma and the 
 * nutty ' taste of good bread increase the appetite for food, and moreover do not 
 lead to distaste of the food. The aeration allows the bread to be better heated 
 in the internal parts, so that the loaf is not too sodden, and thus rendered 
 indigestible. 
 
 {h) Bread Aerated by Chemical Mea^is {non-fermented Bread). — In on& 
 method, sodium bicarbonate and hydrochloric acid are mixed with the dough ; 
 the carbonic acid formed expands in the oven, and the bread is aerated. 
 
 In another. Dr. Dauglish's system, the water to be mixed with the flour 
 is supersaturated with carbonic acid gas, and mixed with the flour under 
 pressure. The carbonic acid expanding with the heat of the oven aerates the 
 bread. This form of bread is Hkedby some, but is somewhat tasteless to others. 
 
 Baking powders consist of tartaric acid and sodium bica^rbonate in different 
 proportions. Church gives as the percentage of these substances in two 
 powders the following : in one, 12-8 per cent, tartaric acid and 11-9 per cent, 
 sodium bicarbonate, with nearly 60 per cent, of rice flour, a httle wheat 
 and rye flour, and a trace of common salt ; in the other, 27*6 per cent, of 
 tartaric acid, 31*6 percent, of sodium bicarbonate, with some potato flour.^ 
 
 Unfermented bread, i.e. bread aerated with carbonic acid, is supposed to 
 have the advantage of not containing alcohol, acetic acid, and other bodies, the 
 product of the action of the yeast. It certainly does not contain these ; but 
 the advantage is a doubtful one, since the yeast begins the digestion of some 
 of the starch, changing it into maltose and dextrine, and also of some of the 
 proteids, since peptone-like bodies ^ are produced by it. 
 
 Chemical Composition of Bread. — From what has been said about the 
 making of bread, it will be seen that bread differs in composition from flour. It 
 is a preparation of flour, indeed, in which the proteids and (to a greater extent) 
 the starch are in part digested ; probably albumoses are in greater abundance, 
 and maltose and dextrine, than in the flour. The crust forms not less than 
 30 per cent, of the loaf. Being the part most exposed to heat, it contains 
 less water than the crumb and more dextrine, owing to the action of the heat 
 into transforming the starch into dextrine. According to Van Bibra, the 
 proteids in the crust of bread form about 9"22 per cent., in the crumb 9-86 
 per cent, (see Table, p. 460) . Even the best bread is shghtly acid. Parkes gives 
 the acidity of two samples of good fresh bread as 0-054 and 0*055 per cent, 
 respectively, reckoned as glacial acetic acid. The acidity of good bread may be 
 somewhat higher, but when the acidity reaches 0*18 per cent, the bread 
 ought to be condemned as sour.^ 
 
 Advantages of Bread as a Food. — These advantages are easily summed 
 up. The development of an aroma and of a pleasant taste during ihe making 
 of yeast bread is a great aid to its consumption. In addition to this the 
 bread is finely divided by the aerating process which it undergoes ; digestion 
 is thus aided. Part of the proteids and starch is also digested, so that, as 
 
 ' Food, by A. H. Church, M.A., p. 76. 
 
 2 These are probably albumoses, although the exact nature of these bodies has not yet 
 been investigated. 
 
 » Hygiene, pp. 717, 718. 
 
4G0 
 
 HYGIENE 
 
 lias been already pointed out several times, yeast bread may be considered as a 
 partially digested flour, and from this point of Yievf it must be regarded as 
 superior in a dietary to the non-fermented forms of bread. This is a point 
 often lost sight of in considering the difterent forms of bread. It is true 
 that cooked starch is very readily digested by the healthy organism, but a 
 partial pre-digestion must be considered an aid to the economy, especially 
 when the complicated feeding of modern life is taken into account. 
 
 Table showing Percentage Composition of Bread 
 
 
 
 - 
 
 Water 
 
 Proteid 
 
 Fat 
 
 starch 
 
 and 
 dextrine 
 
 Sugar 
 
 Cellulose 
 
 Salts 
 
 Troportion of 
 nit. to non-nit. 
 foodstufifs as 
 
 Fine white bread 
 Coarse bread . 
 
 35-59 
 40-45 
 
 7-06 
 6-15 
 
 S-00 
 
 10-40' 
 7-18 
 
 10-90 
 
 0-46 
 0-44 
 
 1-50 
 
 0-30 
 
 9-28 
 
 1-CO 
 
 52-56 
 49-04 
 
 4-02 
 
 2-08 
 
 0-32 
 0-62 
 
 1-70 
 0-16 
 
 1-20 
 
 1-09 
 1-22 
 
 1-30 
 
 1-50 
 0-85 
 
 1-10 
 
 1 :7-5 
 
 1 : 8-4 
 
 1 : 6-3 
 1 :4-7 
 
 1 :7 
 
 quality (Parkes) . 
 Wholemeal bread 
 
 (Church) 
 Biscuits (English) . 
 Navy biscuits 
 
 (Church) 
 
 40-00 
 
 43-40 
 7-45 
 
 10-20 
 
 49 
 
 42 
 58-08 
 
 75-00 
 
 2 
 
 7 
 17-02 
 
 The disadvantages of tread as a food are those of flour ; it has too Httle 
 salt (sodium chloride) and too httle fat. Salt, as we have noticed, is added in 
 the making of bread, beuig present to the amount of about half an ounce in 
 each quartern (4 lb.) The deficiency of fat is made up by eating butter and 
 fat bacon with bread ; a custom originating in experience and ratified by 
 science. 
 
 Preservation of Bread. — After baking, the bread begins to lose water by 
 evaporation. In quartern loaves (with crust on two sides) there is less than 
 6 per cent, loss in 24 hours ; the loss is greater if there is less crust. Stale 
 bread is rendered palatable by moistening and placing in the oven. 
 
 For transport the bread is partially dried, the water being reduced to 12 
 to 14 per cent. (Von Bibra), and softened with Avater before using.^ 
 
 Plain biscuits are a mixture of flour and water well baked. Fancy biscuits 
 contain butter, eggs, milk, and flavouring agents. 
 
 Owing to the prolonged baking, biscuits contain more dextrine than bread, 
 and do not, hke bread, contain the products of the action of yeast on the pro- 
 teids and the carbohydrates. 
 
 The composition of plain biscuit is given in the table above. It differs from 
 bread in containing a much smaller quantity of water and a larger proportion 
 of organic foodstuffs — proteids and carbohydrates. Weight for weight, it is 
 therefore more nutritious than bread, and being easily transported is useful 
 as a substitute for bread when this cannot be obtained. It is apt, however, 
 to be tired of. 
 
 Macaroni is a preparation of flour. It is made from the ' hard ' wheats of 
 France and Italy. The large quantity of gluten present in these hard wheats 
 allows the manufacture of the macaroni as found in commerce. 
 
 In composition it contains 13-07 per cent, of water, 9'02 of proteids, 
 0-30 of fat, 76-77 of carbohydrates, and 0-84 of salts. Maca.roni varies slightly 
 in composition. It is a valuable food, not much appreciated in this country. 
 
 Vermicelli closely resembles macaroni in its nutritive properties. 
 
 ' Composed of 9-1 per cent, proteids and 1-3 nitrogenous non-proteid substances (?). 
 ' For the French preparations of bread, see Parkes's Hygiene, p. 280. 
 
FOOD 4G1 
 
 Examination of Flour. — Adulteeations 
 
 Examination of Flour. — Flour is white with a faint yellow tinge, soft to 
 the touch, very slightly coherent, and not gritty. It possesses a faint cha- 
 racteristic smell ; when mouldy, or commencing to change, it smells musty 
 or sour. Nearly all flours are slightly acid to test paper when moistened \ 
 strong acidity indicates that the starch is beginning to change, forming vege- 
 table acids. 
 
 The quality of flour may thus partly be judged by its appearance, but a 
 further examination is necessary in cases of doubt. The amount of water has 
 to be estimated, the amount of gluten, and the kind of bread the flour makes. 
 
 Amount of Water. — The water should not be over 15 per cent. The 
 usual amount is about 13 per cent. (p. 456), but it may be as low as 10 and 
 as high as 18 per cent. An excess of water tends to decomposition of the 
 flour. 
 
 The amount of water is estimated by taking one gramme of flour and 
 drying in a weighed dish at 100° C. for two or three hours. The flour 
 and dish must be weighed after coohng and the weight of the dish sub- 
 tracted. The loss of weight in the flour multiplied by 100 gives the percent- 
 age of water. 
 
 Amount of Gluten. — A weighed quantity of the flour, say 100 grammes, is 
 taken, thoroughly mixed into a thick paste with lukewarm water, then put 
 into a muslin bag, and washed in a stream of running water till all the starch 
 is washed away. The gluten (with some starch) is then removed from the 
 muslin and again washed in water until it gives no starch reaction (blue 
 colour) with iodine. The gluten is then spread out and dried at 100° C. 
 The weight ought to be 8 to 12 per cent, of the flour. The gluten obtained 
 is not, however, pure proteid ; it contains some fat and sometimes bran. It 
 is often sufiicient to weigh the moist gluten ; if this weight be divided by 2*9 
 it gives the weight of the dried gluten. ^ 
 
 The gluten may be separated from the flour in a dish, without using the 
 muslin, but the muslin hastens the process. 
 
 The amount of gluten is a test of the bread-making quahty of the flour. 
 There are, however, other ways of testing this. The gluten is in one method 
 separated from the flour, put into atube and then into the baking oven. Accord- 
 ing to the amount of expansion of the gluten, so is the bread-making quality 
 of the flour judged.^ Another method suggested by Dr. Charles Graham is 
 the following : — To one ounce of flour four ounces of water are added, and the 
 mixture allowed to stand at the temperature of 26°'5 to 29°"5 C. for two hours. 
 It is then filtered, and one ounce of the last clear portions of filtrate is 
 mixed with one ounce of methylated spirit. A precipitate occurs, consisting 
 of maltose, dextrine, and soluble proteids, and the amount of this precipitate 
 is a sign of the amount of soluble matter produced during the sponge stage 
 of bread making. This method is really an indirect way of estimating the 
 amount of gluten in the flour.^ 
 
 These methods are well supplemented, or even replaced, by making a test 
 loaf of bread from the flour which is being investigated. This bread can 
 then be examined by the methods soon to be discussed. 
 
 For examination of the ash see p. 462. 
 
 ' Parkes, op. cit. p. 716. 
 
 2 This process is used by a French baker, and is quoted by Dr. C. Graham in hia 
 lecture. 
 
 ' Graham, op. cit. p. 18. 
 
462 
 
 HYGIENE 
 
 I 1 ! ) j r-^ i 1 , : 1 
 
 Pig. 107. — Puccinia : hyphse and spores (Parkes). 
 
 Parasites and Adulterations of Flour 
 
 Parasites, both vegetable and animal, occur in flour and are to be detected 
 by microscopical examination. 
 
 The commonest vegetable parasite is a fungus, Puccinia, of two or more 
 species. These are recognised by the tubules or hyphffi, on which are placed 
 the spherical sporangia, containing numerous spores. One species of Puc- 
 cinia causes the svmt or caries : 
 it makes the bread bluish in 
 colour and may produce diar- 
 rhoea. 
 
 Bacteria are also found in 
 decomposing flour. 
 
 A mite (Acarus farina) is 
 also found in flour which is 
 beginning to decompose. It 
 has a rounded body with six or 
 eight legs, and a pointed head 
 supported by protruding man- 
 dibles. The eggs are oval. 
 The weevil [Calandra gran- 
 aria) is much larger than the flour mite, and is readily recognised with the 
 naked eye : it is about five millimetres long and the body is narrow, and has 
 three pairs of legs attached.^ 
 
 The adulterations of flour fall into two classes, the mineral and the organic. 
 The mineral are sand, clay, plaster of Paris, magnesium or calcium car- 
 bonate, and alum. 
 
 For the ready detection of large quantities of mineral substances, the 
 following method is useful : 5 grammes of flour are shaken with 30 to 40 
 cubic centimetres of chloroform, the mineral substances sink to the bottom 
 of the tube, while the lighter starch and proteids float. An examination of 
 the ash is, however, necessary. When incinerated to white ash, the residue 
 ought not to be more than 2 per cent, of the flour. If the ash is more than 
 this, effervescence with acid (hydric chloride) shows added carbonates of the 
 heavy metals, which must be tested for. A large amount of sulphates in the 
 ash means plaster of Paris (calcium sulphate). Clay is shown by its insolu- 
 bility m acids and in water. Lead is readily detected by heating in the 
 blowpipe, when a bead is formed, or by dissolving the ash in acid and testing 
 for the metal. 
 
 The organic adulterations are the starch-containing flours from the other 
 cereals, from LeguminosaB, and from a few other plants. Flour is thus found 
 mixed Avith — 
 
 Barley Buckwheat 
 
 Maize Millet 
 
 Oats Melampyrum 
 
 Rye Lohum 
 
 Potato Agrostemma (corncockle) j- rare admixtures. 
 
 Peas and beans Rhinanthus 
 
 Eice Ergot 
 
 The addition of barley, oats, rye, maize, and the other cereals to wheaten 
 flour does not make it harmful ; but it lowers the value of the bread made 
 
 ' For an account of the moth {Ephcstia clutclla) -which is sometimes found in flour 
 see Parkes's Hygiene, p. 277. 
 
FOOD 4(J3 
 
 from it. The addition of buckwheat, Melampyrum, of Agrostemma, of Rhin- 
 anthus, and of ergot, causes the bread made from such flours to be coloured, 
 while the bread containing Lolium and ergot is poisonous, Lolium does not 
 colour the bread. 
 
 The detection of the additions to flour rests almost solely on the cha- 
 racters of the starch grain peculiar to each plant. For these characters (see 
 pp. 451-454). But there are other facts which aid, viz. the structure of the 
 envelopes of the grains, which differ in each plant, and part of which is always 
 present even in the best milled grains. 
 
 The addition of potato, of peas and beans, of oats, of maize, and of 
 rice, is readily detected by the characters of the starch grains alone. With 
 peas and beans, too, a large amount of cellulose is present, which is detected 
 under the microscope after adding liquor potassae to dissolve the starch. 
 The detection of barley is, however, much more difficult. The starch grains 
 closely resemble those of wheat in size and shape. The envelopes of the 
 barley grain also closely resemble those of Vt^heat, but they are distinguished 
 by their greater delicacy in structure. 
 
 Rye starch grains resemble those of wheat, but the rayed hilum distin- 
 guishes them. The rayed hilum is also seen, it must be remembered, in the 
 starch grains of old wheat, but they are not nearly so numerous as in rye flour. 
 
 Buckwheat is detected by the small round starch grains and by the struc- 
 ture of the coatings, and especially the large cellulose spaces containing the 
 starch grains. It is an adulteration of wheat from the Baltic. Millet is 
 found as an adulteration of wheats from Asia and Africa. 
 
 Flour adulterated with Melampyrum is not altered in colour, but the bread 
 made with it has a smoky- violet tint, 
 
 Agrostemma (corncockle) gives bread a greenish colour, while Rhinanthus 
 imparts a bluish-black colour to the bread. The admixture of MelampyruQi, 
 Agrostemma, or Rhinanthus does not cause poisonous symptoms, 
 
 Lolium temulentum (darnel), however, makes the bread poisonous. 
 The symptoms produced are to some extent gastro-intestinal, but are chiefly 
 referable to the nervous system. Thus there is a sensation of heat in the 
 throat, vomiting, headache, giddiness, staggering, tremulous gait, impaired 
 vision, and symptoms of collapse. Convulsions, hallucinations, dehrium, and 
 paralysis may also be observed, 
 
 Lolium may be detected by the following tests. An alcoholic extract is of 
 a greenish colour and disagreeable taste. The alcohoHc extract of wheaten 
 flour is yellowish, and has not a disagreeable taste. 
 
 Vogel says that the following reaction is given with flour adulterated with 
 Agrostemma, Lolium, beans, or ergot. If to two grammes of the flour 10 cubic 
 centimetres of 70 per cent, alcohol are added, and then 5 per cent, hydric 
 chloride, an orange yellow colour is obtained.' Ergot of rye is occasionally 
 mixed with wheaten flour, but not in this country. It is of most importance 
 in connection with rye bread, which is so commonly used on the Continent 
 (see p. 466). 
 
 Examination of Bread 
 
 The crust of bread should be yellowish brown, firm, and not aerated. 
 The crumb of bread is porous and elastic. There should be no sour smell. 
 
 Potato-flour makes bread soft, while barley flour makes it dry. 
 
 -iwo-zm^ o/ wafer is important to estimate. It varies from 30 to 40 per 
 cent. In bad bread it is 50 per cent. 
 
 ' On this and other points in detail, see A. E. Vogel, Naliru'ngs- und Genuss-Mittcl 
 aus dem Pflanzenreiche, Vienna, 1872 ; Die Vntenucliungcn des Mehles, 1880. 
 
464 HYGIENE 
 
 The acidify of bread has ah-eady been discussed (p. 459). 
 The ash of bread ought never to be over 3 per cent. Potatoes render the 
 ash alkaline, due to sodium carbonate. 
 
 Alum is added to bread to improve the colour and to stop fermentation. 
 Ordinaiy bread may contain a small quantity— about 0005 per cent. — of phos- 
 phate of aluminium (AVanklyn). This amount must, therefore, be deducted 
 from the alum found in the bread examined, the result giving the amount of 
 the salt added. The alum present in alumed bread varies— 12 grains m a 
 quartern loaf, or even 41-6 grains. 
 
 Copper sulphate is readily detected by testing a watery extract of bread 
 -with potassium ferrocyanide : a brown colouration or precipitate is the 
 result. 
 
 The microscopical examination of bread is important. It may show 
 fungi, with their mycelium and spores (Penicillium) , or bacteria in decom- 
 posing bread. 
 
 The deleterious ei'fects of bad bread are due partly to its indigestibility 
 and partly to the poisons contained in it. 
 
 Bread containing too much water, sodden bread, is indigestible, causing 
 a sense of weight in the stomach, &c. Acid bread also disagrees. Acidity 
 is due chiefly to the fatty acids, and these cause acidity and increase this 
 symptom if already present. Acid bread may also lead to diarrhoea. The 
 symptoms produced by decomposing bread are those of decomposing food 
 generally, referable to the gastro-intestinal tract. The presence of fungi 
 (not bacteria) is also said to lead to diarrhoea ; their presence shows that the 
 bread is beginning to decompose, and it is not known whether they are of 
 themselves harmful or whether the bacteria present in such bread are the 
 real poisonous agents.^ 
 
 Alumed bread causes dyspeptic symptoms, with constipation, probably 
 only when there is a large amount of alum present in the bread. Alum is 
 added to inferior flours, and it is a question how far these flours themselves 
 are really responsible for the symptoms. There is no doubt that alum does 
 constipate, and not only that it is itself no food, but that it combines with 
 some of the phosphates of the bread forming insoluble aluminium phosphate. 
 Its use is therefore rightly declared illegal. 
 
 It is not known whether the small amount of sttlphate of copper some- 
 times present in bread causes harmful symptoms. 
 
 Lead p)oisoning is, however, rarely a consequence of the eating of bread. 
 It has occurred where the holes in the millstones have been repaired with 
 the molten metal, and where old wood which had been painted has been used 
 for heating the baking oven.'^ 
 
 The symptoms produced by bread containing Lolium temulentum have 
 already been described. For those caused by ergotised bread see p. 4G7. 
 
 Baeley [Hordeum vulgare) 
 
 The barley of commerce exists in two forms — the pot barley, which is 
 simply the husked grain , and the pearl barley, which is the cleaned grain, 
 somewhat polished by the process of cleaning. Its grain is also ground 
 into flour, and is called prepared barley. It is liable to adulteration. 
 
 As a Food. — Barley is very nutritious. In percentage composition it 
 closely resembles wheaten grain. There is, however, a great difierence in the 
 
 ' Aspergillus glaucus seems to poison horses, causing paralysis. See Parkes, op. cit. 
 p. 291. 
 
 == See Alforcl, Sanitary Eccord, 1877. 
 
FOOD 4G5 
 
 character of the proteids present. These do not, hke those of wheaten flour, 
 form gluten on the addition of water ; they exist solely in the form of what some 
 agricultural chemists call ' soluble albuminoids.' According to Eitthausen, they 
 consist of gluten-casein, gluten-fibrin, mucedin, and albumen.^ According to 
 my own researches, they consist of globulin, albumose, and albumen. Eitt- 
 hausen alone is responsible for the body named mucedin, which is supposed 
 to be vegetable mucin. 
 
 This chemical difference between the proteids of wheat and barley very 
 probably also means a nutritive difference ; but it is almost impossible to 
 speak definitely on this point. It is, however, evident that the great advan- 
 tage of wheaten flour as a food is that it can be made into bread, which, as 
 we have previously insisted upon, is not only a very palatable, but a digestible 
 and a partially digested food. 
 
 A weak solution of barley starch is added to milk in infant feeding to 
 diminish the size of the curds found in. the stomach. As far as is known, the 
 disadvantages of barley as a food rest almost solely in its insipidness ; it is, 
 like other vegetable food, liable to cause digestive disturbance if too freely 
 partaken of. 
 
 Oats {Avena sativa) 
 
 Oatmeal is a valuable food, as is evidenced by its extensive use among 
 the Scotch peasantry, with whom, indeed, it was at one time the chief 
 food. 
 
 The advantage of oatmeal as a food depends on the fact that it can be 
 taken for long periods without distaste, and that the proteid constituents are 
 in large amount, the carbohydrate in fair proportion (less, however, than in 
 wheat or barley), while there is a relatively large amount of fat present. 
 This last foodstuff distinguishes oatmeal greatly from wheaten flour or barley. 
 The proteids present are called gliadin and gluten-casein (avenin). They 
 differ, like those barley, from the proteids of wheat in not forming gluten on 
 the addition of water. On referring to the analysis of oatmeal on p. 456, it 
 will be seen that the proportion of the proteids to the non-nitrogenous organic 
 foodstuffs in it (1 : 5*4) more nearly approaches the normal relation in a dietary 
 (1 : 3^ or 4) than that in barley or wheat. It is therefore more suitable 
 to constitute a large part of the dietary than either of these cereals, if it were 
 not for certain drawbacks to its use. One of these is that oatmeal contains 
 a large quantity of cellulose, which is apt to irritate the intestines, and at any 
 rate interfere with the complete digestion and absorption of the foodstuffs. 
 The coarse oatmeals contain more cellulose than the fine preparations, and 
 are thus more liable to cause intestinal irritation. Oatmeal requires salt. 
 The pericarp of oats contains an alkaloidal principle, which is a stimulant to 
 the muscles ; it causes excitement in horses.^ This alkaloid may perhaps 
 account for some of the beneficial effects of the use of oatmeal in those who 
 do hard manual labour, as well as in the hardy fighters of the Highlands. 
 
 Oatmeal is adulterated with barley, the admixture being readily detected 
 by attention to the size and shape of the starch grains (see p. 454). Eice 
 and maize may also be found in the meal ; the starch grains are characteristic 
 in both. The husks of wheat and barley may also be added. 
 
 * For Eitthausen' s laborious researches on the composition of cereals, &c., see his Die 
 Eiiveisskorper der Getreidearten, &c., 1872. Since Kitthausen's work the nomenclature 
 of the proteids has altered, and the researches of recent years render a re -examination of 
 the proteids of plants necessary. 
 
 ^ See Brunton's Pharmacology, 3rd ed. p. 1056. 
 
 VOL. I. H H 
 
466 
 
 HYGIENE 
 
 EiCE {Orijza satlva) 
 
 The grains are busked, the cuticle removed by machiner)', the dust brushed 
 off, and the surface of the grain poHshed to a greater or less extent. Many 
 varieties exist in commerce, the better class of which, Java, Japan, Carolina, 
 Patna, are well polished, while the inferior varieties, Eangoon, &c., are not 
 so well cleaned. These inferior varieties vary in colour, being reddish some- 
 times, contrasting greatly with the yellowish-white colour of the better 
 varieties. Eice, therefore, ought to be well cleaned, with a certain polish on 
 the surface, free from dust and with the grains whole and not broken. Un- 
 cleaned or partially cleaned rice is in use among the peasantry in India and 
 Burmah. 
 
 As a food, rice must be considered almost solely as a starchy food. The 
 percentage of proteids is small (p. 45G), while that of the carbohydrates is 
 very large — over 78 per cent. The salts are also greatly deficient. When 
 rice is taken, therefore, salt has to be added to supply the deficiency of 
 mineral foodstufis, meat or peas and beans to supply the deficiency of pro- 
 teid, and animal fat (butter, &c.) to supply the fat necessary. Taken in such 
 a mixture, rice is a valuable food ; when taken alone, it has to be consumed 
 in too large quantities to supply the amount of proteid necessary for the 
 body. 
 
 The cooking of rice is important ; it should never be boiled, but steamed so 
 that none of the proteid is lost. 
 
 Eye [Secale cereale) 
 
 Eye is a more important food in the northern countries of Europe than 
 in our own country. It is extensively grown abroad, where it is made into 
 bread — Schwarzbrod, Pumpernickel, &c. — and is the bread of the poorer classes. 
 In this country rye grain is chiefly used for malting. Eye is a very nutri- 
 tious grain : in percentage composition it closely resembles wheat (see p. 456). 
 The proteids present ^ form a kind of gluten on the addition of water, but 
 not to so great an extent as in wheat, nor can the gluten be so readily 
 separated. 
 
 The bread made from rye is dark in colour, heavy, and very acid; it retains 
 its moisture a long time. 
 
 
 Percentage Composition oj 
 
 " Bye Bread 
 
 
 
 
 - 
 
 Water 
 
 Proteid 
 
 Fat 
 
 Sugar 
 
 starch 
 
 Cellulose 
 
 Salts 
 
 German rye-bread 
 Pumpernickel- .... 
 
 42-27 
 43-42 
 
 6-11 
 
 7-59 
 
 0-43 
 1-51 
 
 2-31 
 3-25 
 
 46-94 
 41-87 
 
 0-49 
 0-94 
 
 1-46 
 1-42 
 
 The percentage composition does not, therefore, differ greatly from that of 
 wheaten bread (see p. 4G0). The great drawbacks to rye bread are, however, 
 that it is heavy and acid, and thus indigestible and liable to cause diarrhoea. 
 It has a peculiar odoiu' and taste, and one not pleasant to those accustomed 
 to wheaten bread. A better bread is made by mixing wheaten flour with rye 
 in the proportion of two to one. 
 
 ' These proteids, according to my analysis, are globulin and albumose — the same, 
 therefore, that occur in wheaten flour. Eitthausen calls them vegetable fibrin, casein, 
 and albumen {op. cit.) 
 
 2 The blackbread of Northern Germany, made from the whole of the rye grain. 
 
FOOD 467 
 
 As regards the digestibility of rye bread compared with white brea,d, G. 
 Meyer ' has shown that with white bread a large proportion of the proteids 
 and salts is absorbed than with Pumpernickel or with Munich rye bread, 
 and that this latter form of rye bread is more digestible than the North 
 German commodity. There can be no question, therefore, of the superiority 
 of wheaten bread. 
 
 Eye grain is subject to a disease caused by a fungus, the Claviceps pur- 
 purea. The growth of this fungus causes the grain to enlarge and become 
 black, producing what is known as ergot of rye. The ergot gets mixed with 
 the healthy rye grain, and its presence in the bread leads to a varying train 
 of symptoms called ergotism. This disease, which is practically unknown in 
 this country, is more common in those countries where rye bread is a staple 
 food, but it is getting less common now owing to the greater care in the 
 selection and the milling of the grain. 
 
 Ergotism occurs in epidemics, and is partly due to the ergot and partly 
 to the deterioration (weight for weight) of the food by the presence of the 
 fungus. The symptoms begin with loss of appetite, vomiting, and diarrhoea, 
 and then assume one or two forms. In one form, gangrene of an extremity 
 is the chief symptom ; this is no doubt rightly ascribed to the contraction of 
 the arterioles, caused by ergot cutting off the blood supply to the part. In 
 the other form the symptoms are referable to the nervous system. There is 
 giddiness with loss of sensation in the extremities and abnormal sensations 
 in the skin. There may also be convulsions, and definite alterations of the 
 posterolateral columns of the spinal cord have been found. 
 
 Ergot may be detected in the flour by the microscope by which the 
 mycelium and spores of the fungus will be seen. The following chemical 
 tests have been suggested. To 10 grammes of flour, 15 grammes of ether are 
 added and 20 drops of dilute sulphuric acid (1 in 5) ; the mixture is shaken, 
 and on adding 5 drops of a saturated solution of sodium bicarbonate a 
 violet colour is developed (Hoffman and Wolff). By another method a paste of 
 the flour is made with an alkali, and dilute nitric acid added to excess ; the 
 2nixture when neutralised gives a violet red colour (Laneau). 
 
 Maize (Zea mats, Indian Corn, and Corn) 
 
 This is an important food in some countries — those of Southern Europe 
 and of America — but it is not much used in this country. In Italy it is 
 called polenta. The percentage composition of the maize flour (p. 456) shows 
 it to be a very nutritious food ; and indeed in some parts maize cakes take 
 the place of bread as the staple vegetable food. Made into cakes, it is of 
 course not to be compared to bread either for palatableness or digestibility ; 
 but people are said soon to get accustomed to its use. It is best taken as 
 porridge, made either from corn flour, oswego, or from the ground whole- 
 maize. In the preparation of corn flour, not only is the cellulose removed, 
 but a large quantity of the proteids ; so that, although more digestible than 
 whole maize, it contains a smaller percentage of proteid foodstuffs. 
 
 Like oats, maize contains a large quantity of fat. Some of its proteids 
 have been described under the name of Ze'in, but what this body really is, is 
 not at present known. 
 
 The deleterious effects of maize depend partly on imperfect cooking, thus 
 causing indigestion, and partly on putrefactive decomposition. 
 
 Putrefied maize is said to contain at least two poisonous principles (pro- 
 bably alkaloidal in action). One of these produces muscular spasms, the other 
 
 ' Quoted by Konig, op. cit. See also the original paper in Zeits. f. Biologic. 1871, p. 1. 
 
 B H 2 
 
468 
 
 HYGIENE 
 
 has a narcotic action. The proportion in which the two substances rela- 
 tively exist in the decomposed maize appears to vary. 
 
 A disease of maize, whether due to the fungus Sporisorium ma'icUs 
 (Verdet) or the so-called Bacterium maidis, seems to be one of the factors in 
 the production of 'pellagra, a malady occurring in Lombardy. There may be 
 other factors, such as impoverished food ; for not only do some of the symp- 
 toms (such as serous effusions, &c.) resemble those of scurvy, but the main 
 treatment of the disease is one of a generous diet of fresh animal and vegetable 
 food.. Among the many symptoms of pellagra, the erythematous affection of 
 the skin, fj.'om which the disease derives its name, seems to be the least im- 
 portant. There are gastro-intestinal symptoms, such as nausea, diarrhoea, 
 heat of epigastrum, and a voracious appetite, but the chief s}Tnptoms are 
 nervous. The subjects of pellagra suffer chiefly from melancholia, with stupor 
 and suicidal tendencies, arising in some cases from the intolerable burning- 
 sensation of the skin. Fainting is common, muscular spasms and contracture 
 are also noticed ; some cases, indeed, closely resemble spastic paralysis,, 
 showing an affection of the lateral columns of the spinal cord. The nervous 
 affections in pellagra are therefore as important as those observed in cases of 
 ergotism.^ 
 
 Millet and Buckwheat 
 
 Millet is a food largely used in hot countries, Italy and the Iberian Penin- 
 sula in Europe, in Africa, and in parts of Asia (India, China, &c.) It is 
 obtained from different plants : thus the common millet is prepared from 
 Panicum miliaceum ; the Indian or small millet (Guinea- corn, Dharra) from 
 Sorghum vulgar e ; Italian millet is from Setaria italica ; ^ German millet 
 from Setaria gcrinanica ; spiked millet fi'om Pencillaria sjncata ; and golden- 
 coloured millet from Sorghum saccharatum. 
 
 The chemical composition of the seeds of these different grasses is very 
 similar. The salts consist, like other cereals, largely of phosphates, but also 
 contain silica. 
 
 Percentage Composition of Millet and Biickivheat {shelled) 
 
 - 
 
 Water 
 
 Proteid 
 
 Pat 
 
 Carbo- 
 hydrate 
 
 Cellulose 
 
 Salts 
 
 Proportion of 
 nit. to non-nit. 
 foodstuffs as 
 
 Pa7iimiminiliacewn {comm.on 
 
 
 
 
 
 
 
 
 millet) .... 
 
 11-79 
 
 10-51 
 
 4-26 
 
 68-16 
 
 2-48 
 
 2-80 
 
 • 1 : 6-89 
 
 Sorghum vzilgare (small mil- 
 
 
 
 
 
 
 
 
 let) 
 
 11-46 
 
 8-96 
 
 3-79 
 
 70-25 
 
 3-59 
 
 1-95 
 
 1 : 8-20 
 
 Setaria italica (Italian millet) 
 
 12-04 
 
 7-40 
 
 3-87 
 
 74-21 
 
 1-37 
 
 1-11 ■' 
 
 1 : lo-sa 
 
 Sorgluim saccharatum (golden- 
 
 
 
 
 
 
 
 
 coloured millet) . 
 
 15-17 
 
 9-26 
 
 3-36 
 
 67-99 
 
 2-51 
 
 1-71 
 
 1 : 7-70 
 
 Polygonum faqopynim (buck- 
 
 
 
 
 
 
 
 
 wheat) .... 
 
 12-68 
 
 10-18 
 
 1-90 
 
 71-73 
 
 1-65 
 
 1-80 
 
 1 : 7-10 
 
 From this composition, millets are evidently a nutritious food ; millet 
 bread can be made, and is a substitute for wheaten bread. 
 
 Buckwheat (nat. ord. Polygonacete) is less nutritious as a food than its 
 composition would indicate ; this is eminently the case if the seed is not 
 shelled, as the coating contains a large amount of cellulose. If the whole 
 seed be crushed, and used, cellulose is found to be present to the extent of 
 
 ' See Tuczek, Deutsche med. Wochcnschr. 1888, No. 12, for the nervous symptoms, and 
 Neusser, Wien. med. Wochenschr. 1887, No. 5. 
 ^ Panicum italicum. 
 ^ From the analysis of 0. Kellner, quoted by Konig, op. cit. 
 
FOOD 409 
 
 14*32 per cent,, while in the shelled seed it forms 1-G5 per cent, of the 
 food. 
 
 Baggy is obtained from Eleusine corocana. It is used largely in some 
 parts of India, and is said to be very nutritious. 
 
 Chestnuts [Gastanea vesca) 
 
 Belonging to the same class of foods that have just been considered is 
 the edible chestnut. The amount of proteids and carbohydrates present 
 closely resembles that present in the cereals. Thus there are 10-76 per cent, 
 of proteids, 2*90 per cent, of fat, 73*04 per cent, of carbohydrate (almost solely 
 starch), 2'99 of cellulose, 2*97 of salts, and 7'34 of water in the shelled seed. 
 Chestnuts are therefore chiefly a carbohydrate food ; to a secondary extent, 
 also a proteid food. In some parts of the Continent (Germany and Spain) 
 they form a staple food of the population, replacing bread. 
 
 CLASS II 
 
 The second class, into which we have divided vegetable foods, include 
 those which contain a large percentage of proteid and of carbohydrate ; so 
 that they are both proteid and carbohydrate foods. To this class belong the 
 seeds of the Leguminosse, which are used as food, and a Peruvian food — 
 white quinoa, obtained from the Ghcnopodium guinoa. As a subdivision of 
 this class will be considered certain vegetable products, which, besides con- 
 taining a large amount of proteid, contain a large amount of fat with a vary- 
 ing amount of carbohydrate. These vegetable foods may be described as oily 
 seeds ; such as linseed, the walnut, the ground-nut, &c. They are not of 
 much importance in this or other civilised countries as food, but it is well to 
 bear in mind their nutritive importance in times of scarcity of the staple 
 foods. 
 
 1, With regard to the seed of the Lcgtiminosce, it must be remembered 
 fthat they are used as food in two states, fresh and dried, and that the per- 
 centage chemical composition differs in the two conditions owing to the 
 large amount of water present in the fresh seeds. 
 
 All these seeds, too, possess an aroma which is intensified during cooking ; 
 the older and drier the seed the greater the aroma up to a certain point. 
 
 The character of the proteids present have not been much investigated. 
 These bodies are described as legumin and conglutin (see p. 450), and are 
 ■sometimes called vegetable caseins. But it is probable (see Vines, already 
 •quoted) that the greater part of the legumin and conglutin is derived during 
 ■extraction from the globulin and albumose present in the seed. 
 
 There is a large amount of cellulose present in the dried seeds, a circum- 
 stance which leads to diminished digestion and absorption. In the salts 
 present, the phosphates and potassium and calcium predominate, as in other 
 vegetable foods, over the chlorides and sodium. Most of these seeds, as other 
 vegetable foods, contain a small percentage of iron, combined probably with 
 an organic body. White quinoa is particularly rich in iron (see p. 455). The 
 ■digestibility of the seeds of leguminous plants is an important point. M. 
 Eubner in a series of experiments found that from about 21 to 30 per cent, of 
 the nitrogen of peas was passed out undigested in the faeces, as compared with 
 13 to 14 per cent, of the nitrogen of white bread, and about 17 per cent, of 
 blackbread. Eutgers' experiments showing the unsuitability of leguminous 
 seeds, as replacing animal proteids, have already been described. The mode 
 ■of preparation of the dried leguminous seeds is all-important from a diges- 
 
470 
 
 HYGIENE 
 
 tive point of view. Striimpell,' for example, found that when ground into 
 meal and mixed with milk, butter, and eggs as in the ordinary mode of 
 cooking, the seeds of Leguminosae were more completely digested than when 
 cooked whole and by themselves. This, of course, means, that in the first 
 case the food was more finely divided and the digestible foodstuffs removed 
 more completely from their indigestible (cellulose) covering. These remarks 
 do not apply to the fresh seeds — such as peas — which are rendered quite soft 
 and succulent by cooking. 
 
 The disadvantages of these seeds as food are, that they are liable to cause 
 indigestion if partaken of in too large a quantity — leadnig to acidity, flatu- 
 lence, and diarrhcea. They lack, too, fat and sodium chloride ; these ought to 
 be added in the cooking. 
 
 Percentage ComiMsition of Seeds of Legtwiinosoi, dc. 
 
 
 
 
 
 
 
 Proportion of. 
 
 
 
 Water 
 
 Protcid 
 
 Pat 
 
 liydrate 
 
 Cellulose 
 
 Salts 
 
 uit. to non-nit. 
 
 
 
 
 
 
 
 foodstuffs as 
 
 1. Peas {Pisztin sativuvi) : 
 
 
 
 
 
 
 
 
 Green .... 
 
 78-44 
 
 6-35 
 
 0-53 
 
 12-00 
 
 1-87 
 
 0-81 
 
 1 : 2 
 
 Dried (average) 
 
 13-92 
 
 23-15 
 
 1-89 
 
 52-68 
 
 5-68 
 
 2-68 
 
 — 
 
 Pea flour 
 
 11-41 
 
 25-20 
 
 2-01 
 
 57-17 
 
 1-32 
 
 2-89 
 
 1 :2-3 
 
 2. Beans (Vicia faba) . 
 
 13-49 
 
 25-31 
 
 1-68 
 
 48-33 
 
 8-06 
 
 3-13 
 
 — 
 
 Bean flour 
 
 10-29 
 
 23-19 
 
 213 
 
 59-37 
 
 1-67 
 
 3-35 
 
 1 : 2-6 
 
 3. Haricot beans (Phaseolus 
 
 
 
 
 
 
 
 
 vulgaris) 
 
 11-24 
 
 23-66 
 
 1-96 
 
 55-60 
 
 3-88 
 
 3-66 
 
 1 : 2-4 
 
 Fresh French beans 
 
 88-75 
 
 2-72 
 
 0-14 
 
 6-60^ 
 
 1-18 
 
 0-61 
 
 1 : 2-4 
 
 4. Lentil beans {ErviLin lens) 
 
 12-33 
 
 25-94 
 
 1-93 
 
 52-84 
 
 3-92 
 
 3-04 
 
 — 
 
 Flour .... 
 
 10-73 
 
 25-46 
 
 1-83 
 
 57-35 
 
 2-01 
 
 2-62 
 
 1:2-3 
 
 5. Soja beans (yellow) {Soja 
 
 
 
 
 
 
 
 
 hispida, var. tumida) 
 
 9-89 
 
 33-41 
 
 17-68 
 
 29-31 
 
 4-67 
 
 5-10 
 
 1 : 1-4 
 
 6. Yellow lupin seeds - {Lu- 
 
 
 
 
 
 
 
 
 l)inus luteiis) . 
 
 13-98 
 
 38-25 = 
 
 4-38 
 
 25-46 
 
 14-12 
 
 3-81 
 
 — 
 
 7. Lathyrus sativus 
 
 12-74 
 
 24-08 
 
 2-38 
 
 51-38 
 
 6-60 
 
 2-82 
 
 — 
 
 8. White Quinoa^ (Cheuopo- 
 
 
 
 
 
 
 
 
 dium Quinoa) . 
 
 16-01 
 
 19-18 
 
 4-81 
 
 47-78 
 
 7-99 
 
 4-23 
 
 1 : 2-7 
 
 There is a great difference between the composition of fresh peas and 
 dried : roughly, 1 part of dried peas by weight equals 4 parts of green in 
 proteid and carbohydrate. 
 
 Soja beans, from the large amount of fat they contain, approximate in 
 composition to the oily seeds presently to be considered. 
 
 Percentage Composition of Oily Seeds 
 
 
 
 1 
 
 
 
 Proportion of 
 
 
 
 Water Proteid 
 
 Cellulose 
 
 Ash 
 
 nit. to non-nit. 
 
 
 
 
 
 
 foodstuffs as 
 
 1. Linseed {Limim ^lsita- 
 
 
 
 
 
 
 
 
 tissimmn) 
 
 9-23 
 
 22-57 
 
 33-64 
 
 23-23 
 
 7-05 
 
 4-28 
 
 1 :2-5 
 
 2. Walnut {Juglans regia) 
 
 7-18 
 
 15-77 
 
 57-43 
 
 13-03 
 
 4-59 
 
 2-00 
 
 1 : 4-4 
 
 3. Hazel nut {Corylus avel- 
 
 
 
 
 
 
 
 
 lana) .... 
 
 7-11 
 
 17-41 
 
 62-60 
 
 7-22 
 
 3-17 
 
 2-49 
 
 1 :4-0 
 
 4. Sweet almond (Amygdalus 
 
 
 
 
 
 
 
 
 communis) 
 
 6-02 
 
 23-49 
 
 53-02 
 
 7-84 
 
 6-51 
 
 3-12 
 
 1 : 2-6 
 
 5. Pea- or ground-nut {Arachis 
 
 
 
 
 
 
 
 
 hypogcca) (shelled) . 
 
 6-95 
 
 27-65 
 
 45-80 
 
 16-75 
 
 2-25 
 
 2-64 
 
 1 : 2-2 
 
 1 Centralb.f. die. vied. Wissensch. 1876, p. 47. 
 
 2 The composition of blue and garden lupin seeds is very similar. 
 
 ^ Minus 2-25 per cent, for nitrogenous non-proteid bodies, leaving the proteid 36 per 
 cent. ■* Analysed by Voelcker, 1857. * 1"16 sugar. 
 
FOOD 
 
 471 
 
 The character of the oily seeds has already been described. They are not 
 much used as food, and are usually eaten in this country only in small 
 quantities. In some countries, however, peanuts form almost one of the 
 staple foods. 
 
 From their close texture these seeds are indigestible ; and they do not 
 cook well. 
 
 CLASS III 
 
 To this class belong vegetable foods which are chiefly used as yielding 
 carbohydrates. The commercial starches and sugars (sago, arrowroot, &c.) 
 belong to this class. They have already been considered (p. 451.) 
 
 The next important member of this class is the potato ; of very subsidiary 
 importance as food are beetroot and Jerusalem artichoke. Many fruits 
 yield a large quantity of carbohydrates (sugars), but they cannot be con- 
 sidered as carbohydrate foods of prime importance. 
 
 The potato is the tuber of /So Zamtm tuberosum, and is an absolute necessity 
 as a food to the poor peasantry of some countries — as Ireland. Its cultiva- 
 tion free from disease, to which it is very subject, is of great economic impor- 
 tance to these people, as the loss of the potato crop means starvation to 
 them. 
 
 In chemical composition, potatoes show a small proportion of proteids and 
 a large proportion (for a fresh food) of starch, while the salts consist, as in 
 other vegetable foods, of an excess of phosphates and potassium over sodium 
 chlorides. 
 
 The juice of the potato is acid, due to the vegetable acids (especially 
 citrates), partly free and partly in combination with the alkali metals 
 (potassium, sodium, calcium). 
 
 As a food, potatoes yield carbohydrates and act as an antiscorbutic. 
 
 Percentage Composition 
 
 - 
 
 Water 
 
 Proteid 
 
 Fat 
 
 Carbo- 
 hydrate 
 
 Cellulose 
 
 Ash 
 
 Proportion of 
 nit. to non-nit. 
 foodstuffs as 
 
 Potatoes .... 
 Beet {Beta vulgaris) 
 ■Jerusalem artichoke {Lolimn 
 tuberosum) .... 
 
 74-98 
 82-25 
 
 79-24 
 
 2-08 
 1-27 
 
 1-76 
 
 0-15 
 0-12 
 
 0-14 
 
 21-01 
 14-40 
 
 16-29 
 
 0-69 
 1-14 
 
 1-49 
 
 1-09 
 0-82 
 
 1-08 
 
 1 : 10-0 
 1 : 11-4 
 
 1: 9-3 
 
 Potatoes are boiled or roasted in their skins so that none of the salts is 
 lost ; they may also be steamed. 
 
 Examination of Potatoes. — The quality of the potato is judged by its specific 
 gravity and by the absence of the fungus, Phytophora infestans, which causes 
 ' potato murrain.' 
 
 Parkes ^ gives the following table of the quality of potatoes as tested by 
 their specific gravity : — 
 
 Below 1068 
 Between 1068-1082 
 Between 1082-1105 
 Above 1105 
 Above 1110 
 
 The quality is very bad 
 ,, inferior 
 
 „ rather poor 
 
 ,, good 
 
 ,, best 
 
 Parkes also gives the following ready, if somewhat rough, method of taking 
 the specific gravity, by means of an ordinary urinometer : — 
 
 ' Op. cit. p. 300. 
 
472 
 
 HYGIENE 
 
 Take a sufficient quantity of water, and dissolve in it h oz. to 1 oz, of 
 salt, and take the specific gravity ; then add another h oz. or 1 oz. and 
 take the specific gravity again. The operation is repeated until the amount 
 of salt added is found, with which the specific gravity will be definitely 
 increased. Then salt enough may be added to bring the specific gravity up 
 to the desired amount, i.e. the specific gravity of the potato. 
 
 The fungus is detected by the microscope. Partly diseased potatoes may 
 be utilised, either by obtaining the starch from them by washing or by cutting 
 in thin slices and drying in hot-air chambers: they will then keep. 
 
 Potatoes may be preserved by peeling, slicing, and placing in molasses or 
 drying and granulating. 
 
 CLASS IV 
 
 This class of vegetable foods contains articles of diet which supply water, 
 vegetable acids, and salts to the organisms. It may be divided into two 
 groups, succulent vegetables and fruits. 
 
 To all succulent vegetables common salt is added in the cooking, and to 
 the majority butter is a valuable addition. Besides the nutritive value of 
 vegetables, there is another use and not an unimportant one ; they give relish 
 to the food, and thus act like the other food-accessories, shortly to be discussed. 
 Of these the different varieties of salads may be mentioned : lettuce, endive, 
 mustard and cress, primrose, and dandelion, with onions and celery, &c., which 
 possess pungent aromatic principles. 
 
 Of the ordinary vegetables used it will be sufficient to give the composition 
 of turnips, carrots, cabbage, spinach, and cauliflower ; the other vegetables 
 are closely similar in composition. 
 
 Percentage Composition of Vegetables 
 
 - 
 
 Water 
 
 Proteid 
 
 Fat 
 
 Carbohydrate 
 
 Cellulose 
 
 Salts 
 
 1. Turnips (Brassicaraparajpifera) 
 
 90-78 
 
 1-18 
 
 0-22 
 
 5-89 
 
 1-13 
 
 0-80 
 
 2. Carrots {Dcnicus carota) 
 
 86-79 
 
 1-23 
 
 0-30 
 
 9-17 
 
 1-49 
 
 1-02 
 
 3. White cabbage (Brassica oler- 
 
 
 
 
 
 
 
 acea) 
 
 80-97 
 
 1-89 
 
 0-20 
 
 4-87 ' 
 
 1-84 
 
 1-23 
 
 4. Spinach {Spinacia oleracea) 
 
 88-47 
 
 3-49 
 
 0-58 
 
 4-44 - 
 
 0-93 
 
 209 
 
 5. CauHflower {Brassica oleracea 
 
 
 
 
 
 
 
 botrijtis) ..... 
 
 90-89 
 
 2-48 
 
 0-34 
 
 4-56^ 
 
 0-91 
 
 0-83 
 
 The absence of fresh vegetables in a diet leads to the production of 
 scurvy. The dried vegetables sold are antiscorbutic ; they are serviceable 
 for making soups, hashes, &c. 
 
 Little need here be said of the composition of fruits. They are rich 
 in water, vegetable acids, and salts, and are eminently antiscorbutic (espe- 
 cially the lemon). Some contain large quantities of sugar (the banana, e.g.) ; 
 others are rich in oil (the mature cocoa-nut). But, except for their anti- 
 scorbutic properties and their pleasant taste, they are quite subsidiary as 
 articles of diet. 
 
 Lemon-juice, Lime-juice, Vinegar 
 
 1. Lemoii-pdce is one of the most important antiscorbutics, and its use 
 in the Navy and mercantile marine has practically eradicated scurvy from 
 among sailors. 
 
 ' Consisting of 2-29 per cent, sugar and 2-58 per cent, other carbohydrates. 
 ^ 0-10 per cent, sugar, 4-34 per cent, other carbohydrates. 
 • 1-21 i^er cent, sugar, 3-34 per cent, starch, &c. 
 
FOOD 
 
 ^73 
 
 Both lemon- and lime-juice contain a large proportion of citric acid, 
 with some malic acid, sugar, and proteid. The citric acid is the important 
 constituent. 
 
 Percentage Comjoosition of Lemon- and Lime-juice. 
 
 Total 
 solids 
 
 Lemon-juice, fron Citrus limonwn 
 Lime-juice, from Citrus limctta 
 
 ' 8-597 
 9-222 
 
 Consisting of 
 Citric acid , Ash 
 
 0-822 
 7-201 
 
 0-259 
 0-419 
 
 Sulpliurio 
 acid 
 
 0-002 
 0002 
 
 Sp. feT-. 
 
 10H2 
 1035 
 
 To half a pint of lemon-juice one ounce of brandy is added as a preserva- 
 tive. When administered it is diluted and mixed with sugar. The daily 
 quantity to be taken as an antiscorbutic (when fresh vegetables are unpro- 
 curable) is one ounce. 
 
 Adulterations. — Both lemon- and lime-juice areliableto decomposition and 
 to adulteration. The juice ought to be clear, with an acid but not bitter 
 taste, and the aroma of the fruit. 
 
 Lemon-juice is manufactured : a solution of citric acid in water flavoured 
 with essence of lemon is made. 
 
 The juice is watered ; the specific gravity and the acidity (as tested by 
 standard alkaline solution) detect this adulteration. 
 
 Sulphuric acid is the most important adulteration. It may be present up 
 to 0"434 or even 0-825 per cent. (Hassall). It is detected by acidulating with 
 hydric chloride and adding barium chloride, when the insoluble barium 
 sulphate is thrown down. 
 
 Hydrochloric acid and nitric acid are sometimes added. 
 
 Tartaric acid is detected by adding acetate of potassium ; on standing, 
 the acid potassium tartrate will be precipitated in crystals. 
 
 2. Vinegar comes under the same heading as lemon -juice, although it is 
 not so powerful an antiscorbutic. 
 
 Vinegar is of two kinds— wine vinegar and malt vinegar. The chief varia- 
 tion in composition is the amount of acetic acid (reckoned as glacial acetic 
 acid) the different vinegars contain. The percentage of acetic acid ought not 
 to be below 3 per cent. ; in the best vinegars it may be as high as 6 per cent. 
 A small quantity of sulphuric acid is added to English vinegar. 
 
 Percentage Composition of Vinegar 
 
 - 
 
 Sp. Gr. 
 
 Alooliol 
 
 Extract 
 
 Acetic 
 acid 
 
 Tartaric 
 acid 
 
 Tartar 
 
 G-lycerine 
 
 Ash 
 
 Ordinary vinegar . 
 Wine vinegar 
 
 1016-1019 
 1015-1022 
 
 trace 
 1-05 
 
 0-430 
 1-066 
 
 4-02 
 
 5-77 
 
 0-149 
 
 0-124 
 
 0-211 
 
 0-113 
 0-184 
 
 Vinegar is diluted with water ; the specific gravity (which is lowered) and 
 the degree of acidity detect this. 
 
 Sulphuric acid in excess is detected by barium chloride and hydrochloric 
 acid. Copper, common salt, and lead may be detected by the appropriate 
 chemical tests. 
 
 The use of vinegar is that, like other vegetable acids (citric, &c.), it tends 
 to maintain the alkalinity of the blood and the liquids that bathe the tissues. 
 
 The acetic acid is converted into carbonate in the body. In doses of from 
 half to one ounce daily, vinegar is an antiscorbutic. It may be mixed with 
 the food and even taken as a drink when much diluted. 
 
474 HYGIENE 
 
 ScuEVY {Scorhuhis) 
 
 Scurvy is an important disease in connection with food. It has been 
 several times referred to. Many different theories have been brought forward 
 to explain the pathology of the disease, but none of these can be considered 
 quite satisfactory. In scurvy there is a profound change in the blood, the 
 result of which is seen in effusion of blood (ecchymoses) in various parts and 
 in fibrinous exudation in the muscles and gums, and in a condition of anaemia 
 of all the tissues. There seems no doubt that this change in the blood is 
 the chief pathological factor in the disease. Speaking from a chemical 
 point of view, a change in the blood may be brought about either by an 
 altered nutrition of the tissues or of a particular tissue, or by an alteration 
 in the quantity and quality of the food absorbed into the blood-stream. 
 There is much evidence to show that the change of the blood in scurvy is 
 due to the quantity and especially to the quality of food eaten. Thus we 
 have the strong evidence of scurvy present in sailors (at a period, now happily 
 past), who for long periods were fed both insufficiently and with a diet chiefly 
 consisting of salt pork and biscuit. Here the deficiency in the diet was that 
 of fresh vegetables, to the absence of which scurvy has been ascribed. It is 
 known that on a diet of meat and fat alone scurvy may appear, and cereals 
 and the seeds of Leguminosc^ have no antiscorbutic power. The food 
 principle in vegetables to which are ascribed antiscorbutic property are 
 the vegetable acids — citric, tartaric, acetic, malic, lactic — and there is some 
 reason for this. According to Busk and Garrod, the deficiency of potash 
 in the system is the basis of scurvy : potassium salts (except those of vegetable 
 acids) are, however, not antiscorbutic. 
 
 Ealfe states that the alkaline salts of the blood in scurvy are absolutely 
 decreased. Now the chief source of alkalinity in the body are the vegetable 
 acids just mentioned, for they are changed into carbonate in the system and 
 combine in this state with potassium and sodium, thus forming alkaline salts. 
 Add to tliis the fact that articles of diet containing these acids or their salts 
 are the best antiscorbutics, and we are almost driven to the conclusion that 
 it is the absence of those important principles in the food which is the 
 main cause of scurvy, especially as this absence means, as a rule, a general 
 deficiency of the diet. This idea is not against the fact that fresh meat may 
 also be antiscorbutic, because fresh meat contains a fair quantity of sarco- 
 lactic acid. 
 
 The following may be mentioned as antiscorbutics : — Fresh vegetables, such 
 as potatoes, cabbage, cauliflower ; fresh fruit ; lemon-juice ; dried vegetables, 
 although these are not so useful as fresh ; vinegar ; and the alkaline salts of 
 the vegetable acids, these, however, not being nearly so useful as good lemon- 
 or hme-juice. 
 
 FOOD-ACCESSORIES 
 
 Almost as important to civilised man as the foodstuffs which are necessary 
 for existence are substances which enable the food to be taken with relish ; 
 such substances may appropriately be called food-accessories. These in 
 many instances contain aromatic bodies, to which their action is due. The 
 smell of well-cooked meat is decidedly appetising ; the absence of aroma in 
 badly cooked or over- cooked meat certainly diminishes its consumption. 
 Many other substances act as relishing agents through the aromatic bodies 
 contained in them, the effect in the brain through the special senses affecting 
 the digestive organs. On the other hand, some of these food-accessories have 
 
FOOD 475 
 
 a special action on the central nervous system, a stimulant or a sedative 
 effect, which is in some cases their chief action. Such food-accessories are 
 alcohohc beverages, tea, coffee, &c. A third action, which may be ascribed 
 to food-accessories, is that of affecting the secretion of the digestive juices, 
 and of acting directly on the chemical processes of digestion. 
 
 It is not surprising that, with increase of civilisation and its attendant 
 high development of the special senses and the central nervous system, 
 special stimulants of these parts of the nervous system should be in common 
 use. But it is a remarkable fact that the use of food-accessories having such 
 effects as have been described is universal in the world, in savage as well 
 as in civilised nations. The civilised man has the advantage over the savage 
 in the refinement of his food-accessory stimulants, but not in the quantity 
 of them he utilises. 
 
 We may, from what has been said, usefully divide food-accessories into 
 aromatic principles (which affect the digestive system through the central 
 nervous system), into those which directly affect the central nervous system 
 after being absorbed, and into those which directly affect the digestive system. 
 The aromatic principles are often associated with substances which have one 
 or other of the two last actions. 
 
 As examples of the aromatic principles, we may cite the aroma of cooked 
 meat, especially roasted meat, an aroma due to an imisolated principle, 
 sometimes called osmazome. The aroma differs in each variety of meat ; 
 that of beef is different from that of mutton, of goat's flesh, of pork, &c. ; the 
 cooked blood, too, has a different aroma in each animal. This actual aroma 
 is most marked in animal foods ; with ordinary vegetable foods, as a rule, it 
 is less marked. The taste of well-made bread (the ' nutty ' flavour) is a 
 well-marked characteristic of it, and is no doubt not only due to an aromatic 
 principle, or aromatic principles, but also to the mixture of dextrine, 
 starch, &c., with sugar and the acids which have been described as the pro- 
 ducts of the activity of yeast. Most of the other cereals have little aroma, 
 and flavouring agents are usually added to them, the commonest being- 
 butter and common salt. The leguminous seeds have, as a rule, a well- 
 defined aroma. Some other vegetable products are used almost solely as 
 food-accessories, such as onions, spices, &c. These, however, have probably 
 another and more important action, viz. that of directly stimulating the flow 
 of the digestive juices ; a subject to be considered later. 
 
 To the second class of food-accessories which we have made belong the^ 
 most important articles of diet under this heading, viz. those which have an. 
 effect on the central nervous system ; such as all alcoholic beverages, tea, 
 coffee, cocoa, &c., and beef-tea to a less degree. They all have, however, 
 properties which would entitle them to be placed under all three classes of 
 food-accessories. For not only do they act on the central nervous system,, 
 but they often possess a delicate aroma, and they have, as we shall see, a. 
 powerful effect on the digestive juices and the chemical processes of digestion. 
 But there seems little doubt that the object for which they are taken by 
 mankind is that of affecting the central nervous system. 
 
 This they do in two ways : small doses stimulate, large doses depress ; 
 medium doses may be said to act as a sedative. In the alcoholic beverages; 
 these effects are due to the alcohol present in them ; in tea, coffee, cocoa, &c., 
 they are due to the active principles caffeine and theobromine. Both alcoholic 
 beverages and tea, and its congeners, have other effects besides those due- 
 to their respective active principles. These effects are, however, best consi- 
 dered under another heading. 
 
476 HYGIENE 
 
 It is difficult to give physiological reasons for the custom of taking cere- 
 bral stimulants and sedatives as food-accessories. If it is not simply a 
 question of morals, as some consider it is, one explanation may be given. Man, 
 both in the savage and in the civilised state, is accustomed to eat large meals, 
 which tend to diminish the activity of the central nervous system, and thus to 
 diminish the digestion of the ingested food. Cerebral stimulants may by 
 keeping up the activity of the central nervous system aid in the prolonged 
 digestion of a large meal. It is not simply that alcoholic stimulants, to take 
 an example, in moderate doses increase the How of the digestive juice, and 
 thus aid digestion, because a slight excess of the ordinary alcoholic drinks, 
 as we shall see, actually retards the chemical processes of digestion. The 
 explanation given seems, according to our present knowledge, the only likely 
 one, though evidently it is not complete. 
 
 The third class of food-accessories is an important one. The natural 
 aroma of foods is, as Ave have said, appetising ; this appetising action, which 
 may aft'ect the brain through the special senses of the eye or nose, is asso- 
 ciated with a How of the salivary secretion, and a corresponding flow of gastric 
 juice. The food-accessories we are now considering have a similar stimulat- 
 ing action on the digestive juices when they are ingested. Small doses of 
 alcohol, for example, increase the flow of gastric juice, and thus act as a dis- 
 tinct aid to digestion. Small quantities of soups and beef-tea probably act 
 in the same way, and although there is no very definite knowledge on the 
 subject, spices, hot flavouring agents and onions, &c., are considered to have 
 , a similar action. Schiff, indeed, affirms that it is necessary that certain 
 substances (peptogens) should be absorbed before the gastric juice can be 
 secreted ; among such substances are dextrine and peptones. This, however, 
 is doubtful. 
 
 Not only, however, have this class a stimulating effect on the salivary and 
 gastric secretions, but they stimulate in many cases the muscular movements 
 of the stomach. Alcohol and spices probably have this action. On the 
 other hand, they have by many experiments been shown to have a powerful 
 retarding effect on the chemical processes of digestion. 
 
 The experiments, the results of which will presently be detailed, were all 
 performed outside the body ; they were artificial digestions. A great dis- 
 tinction must be drawn between digestive experiments outside the body and 
 the actual processes occu.rring in the stomach, which is the organ that now 
 concerns us, inasmuch as it is the receptacle of the food. For the stomach 
 is an organ in which not only the chemical process of digestion is progressing, 
 but the products of digestion (peptones, &c.), the salts, and the diffusible 
 bodies taken in with the food (such as alcohol, tea, &c.), are constantly being 
 absorbed. When we speak, therefore, of a certain percentage of a substance 
 hindering digestion in a test tube, it is not accurate to apply the results ob- 
 tained directly to the phenomena of digestion in the stomach. But although 
 this is so, yet valuable dietetic deductions may be drawn from the results of 
 experiments on artificial digestion. Sir "William Roberts, W. Fraser, Bikfalvi, 
 and others have made experiments in this direction, and the conclusions arrived 
 at have been closely similar. On the digestion of starch by the saliva, Eoberts 
 found that the distilled spirits, coffee, and cocoa had practically no effect 
 when these substances were used in quantities which would be considered as 
 dietetic doses. On the other hand, tea and wines of all kinds had a powerful 
 retarding effect on the digestion of starch — an effect, in the case of tea, not 
 due to the volatile oil, or the theine (caffeine), but probably due to the taimin. 
 In the cases of wines, the effect was probably due to the acidity of the wines ; 
 sahvary digestion is not active, as is well known, in a distinctly acid medium. 
 
FOOD in 
 
 The effect of food-accessories on gastric digestion is much more important 
 than that on salivary or pancreatic digestion. Salivary digestion is of minor 
 importance in man, whereas the preparation and digestion of the food in the 
 stomach are of vast importance. If gastric digestion is too much delayed, 
 there is a liability to the occurrence of various forms of bacterial fermenta- 
 tion (the butyric acid fermentation, &c.), which lead to gastric disturbance 
 and malassimilation of the food. 
 
 Eoberts ^ and others have shown that in artificial gastric digestion 
 proof spirit ^ has no appreciable effect unless it is present to the extent of 10 
 per cent, of the mixture. Twenty per cent, of proof spirit added to the digest- 
 ing mixture causes a well-marked retardation of the fermentative process, 
 while if 50 per cent, be added the activity of the ferment is paralysed. Proof 
 spirit, brandy, whisky, and gin (the distilled spirits) affect gastric digestion 
 only in proportion to the amount of alcohol they contain. If we inquire 
 what dose of these ardent spirits is requisite to retard digestion in the stomach, 
 we find that a much larger quantity is necessary to do this than is ordinarily 
 taken. Thus, taking the average mass of food in the stomach as about two 
 pounds, a dose of two ounces of average brandy would be equivalent to only 
 5 per cent, of proof spirit in the mixture— a proportion which does not appre- 
 ciably affect the chemical process of digestion. It is also to be remembered 
 that even this quantity of brandy does not represent 5 per cent, of proof 
 spirit for any length of time in the stomach, for the diffusible alcohol is 
 constantly being absorbed ; larger doses of brandy than two ounces would 
 therefore probably not affect the process of fermentation. We may therefore 
 conclude that as food-accessories the ardent spirits (brandy, whisky, gin) 
 have a twofold action ; they stimulate the secretion of gastric juice when 
 taken in small quantities, they retard gastric digestion when taken in intoxi- 
 cating doses, dietetic doses having no effect in this direction. 
 
 The effect of wines, malt liquors, tea, coffee, &c., and beef-tea, and whey 
 is quite different from that of the ardent spirits. To some extent, when 
 taken in small doses, they act as stimulants to the secretion of gastric juice, 
 but they all have a well-marked retarding effect on the chemical process of 
 gastric digestion. In the case of wine and malt liquors, this retarding effect 
 is not proportional to the amount of alcohol contained in them ; there is 
 something else present which is more retarding than alcohol. Of the wines, 
 sherry and port wine have the most retarding effect. Thus 20 per cent, of the 
 sherry which was used (equal to 8 per cent, of proof spirit) added to the diges- 
 tive mixture trebled the time of normal digestion. A proportion of 40 per cent. 
 (16 per cent, proof spirit) completely stopped digestion. These results differ 
 from those described as due to alcohol pure and simple. As Eoberts points 
 out, the use of half a pint of sherry at dinner would make a mixture in the 
 stomach containing 25 per cent, of the wine ; a proportion which, as we have 
 just seen, markedly retards the process of digestion. Such a habit, therefore, 
 can only be deleterious. 
 
 Hock, claret, and champagne (containing from 10 to 12 per cent, of 
 alcohol) have a less retarding effect than port or sherry ; and champagne 
 has a less effect than the first two wines mentioned. Twenty to 40 per 
 cent, of the wines in the digestive mixture hinders digestion ; an effect out 
 of proportion to the alcohol they contain, which would only be present in 
 the proportion of 2 to 4 per cent. The effect of malt Hquors on peptic 
 
 ' Dietetics and Dyspepsia, London, 1885. 
 
 2 Proof spirit contains by weight 49-3 per cent, of absolute alcohol and 57-09 per cent. 
 by volume ; a 10 per cent, mixture may therefore be considered as containing approxi- 
 mately 5 per cent, of absolute alcohol. 
 
478 HYGIENE 
 
 digestion is more marked than that of these light wines, but is, as in their 
 case, out of proportion to the alcohol they contain. Ten per cent of ' light 
 English table beer ' and of lager beer added to the digestive mixture did not 
 delay digestion ; but a retarding effect was noticed when 20, 40, and GO 
 per cent, of these liquors were added. These percentages represent only 
 about 1, 2, and 3 per cent, of alcohol. Beer is often drunk in large 
 quantities at meals, and Eoberts considers that it must often be present 
 in the stomach contents in the proportion of 50, GO, or even 80 per 
 cent. Such proportions would distinctly retard the chemical process of 
 digestion. 
 
 Tea, coffee, and cocoa all retard gastric digestion, and cafe noir (to the 
 extent of 10 per cent.) was very powerful in this respect. Beef-tea retards, 
 whey to a less extent. 
 
 The retarding effect on digestion of the food-accessories is ascribed by 
 Sir William Eoberts to the presence in the liquids of the salts of organic acids 
 and of neutral inorganic salts — speaking more particularly to lactates and sar- 
 colactates (in beef-tea) and to the chlorides of potassium and sodium. When 
 salts of the organic acids (lactates, butyrates, &c.) are taken into the stomach, 
 they are decomposed by the hydrochloric acid of the gastric juice, by which, 
 therefore, the organic acids are set free. Gastric digestion is most active in 
 the presence of free hydrochloric acid, and although the presence of a small 
 proportion of free organic acids in the stomach contents does not stop diges- 
 tion, it tends to hinder the activity of the pepsin. The development of these 
 acids probably explains the retarding effect of beef-tea and whey on digestion, 
 since hyperacidulation by means of hydrochloric acid brings the activity of the 
 digestion almost up to the normal in the presence of these food-accessories. 
 Hyperacidity of the digestive mixture does not counteract the retarding effect 
 of light wines and of Burton ale on digestion ; and with port or sherry it 
 actually aggravates the retardation. The retarding effect on digestion of 
 wines and malt Hquors is not, therefore, due to organic acids, but probably 
 in part to the neutral inorganic salts present. The question, hoAvever, is not 
 settled. 
 
 It is interesting to note that Eoberts found effervescent water to be a slight 
 stimulant to the chemical processes of gastric digestion ; a result expHcable 
 on the consideration of the evolution of bubbles of carbonic acid gas agitating 
 the digesting mixture. 
 
 On pancreatic digestion the effect of food-accessories is interesting. 
 Eoberts found that the retarding effect of wines, beer, and tea on the pan- 
 creatic digestion of starch was due to the acidity of these beverages ; if the 
 acidity were neutralised, as it is normally in the duodenum, they had no 
 retarding effect. 
 
 The effect of the food-accessories on the pancreatic digestion of proteids 
 was found to be practically nil. Tea and coffee had no appreciable effect, 
 and the digestion of milk was only slightly interfered with by 10 per cent, 
 of proof spirit. A large percentage of alcohol is probably never present in 
 the duodenal contents, since it is so readily absorbed from the stomach. 
 
 The general action of the food-accessories which has just been discussed 
 is accompanied by special actions of individual food-accessories which are 
 more appropriately discussed under each separate heading. It may be well 
 here to discuss certain conclusions from the facts concerning the general 
 action of food-accessories which have just been discussed. 
 
 1. As to the aroma of food and the use of so-called condiments. Those 
 who can easily procure a sufficiency of food can also produce a variety, and 
 there is evidence to show that a variation in the articles of diet used, although 
 
FOOD 479 
 
 one may be as nutritious as the other, is of great service in preserving health. 
 The lower animals, and probably the lower races of mankind, can subsist 
 on monotonous food ; but civilised man seems to require variety. This 
 variety includes variation in the different aromatic principles present in foods, 
 variations in the mode of cooking, and variations in the condiments, spices, 
 pepper, vinegar, &c., added to the food in the cooking. Such facts are im- 
 portant to bear in mind in connection with public institutions and bodies 
 of men where all are supplied with the same kind of food, and where economy 
 has to be considered. 
 
 Monotony of food, the bad cooking of food, or the non-addition of condi- 
 ments (which are very cheap) may lead to disgust and refusal of food or to 
 disordered digestion. As examples of the difference in this respect between 
 foods of similar composition may be cited bread and biscuits : good bread is 
 never tired of during one's lifetime ; good biscuits if eaten for any length of 
 time are refused at last. So with well-cooked fresh meat and the over-cooked 
 tinned meat ; the first is greatly superior to the latter as an article of diet. 
 
 2. We shall have to discuss the possible useful action of those food-acces- 
 sories which act on the central nervous system under the separate headings 
 of alcoholic beverages, tea, &c. One possible explanation of their utility has 
 already been brought forward (p. 476). 
 
 3. With regard to the retarding effect on digestion of many of the food- 
 accessories, it has been suggested by Sir William Eoberts that, anomalous 
 as it may seem, the retardation may be in many instances of actual benefit 
 to the absorption of food. Thus in the case where large meals are eaten, with 
 which these digestion-retarding food-accessories (soup, beer, wines) are often 
 taken in fairly large quantities, the retardation of digestion may be of benefit 
 in allowing the food to be more completely digested and absorbed. The 
 length of time food remains in the stomach varies according to the quantity 
 and kind of food, and whether the meal taken has consisted of one article of 
 diet or is a mixed meal. Tliis has been already discussed (p. 419). Leube,* 
 experimenting on healthy persons, found that after an average meat meal 
 the stomach was not completely empty under seven hours. This, however, 
 is against what we know from the experiments of Beaumont and Richet. 
 Leube's estimate is too high. It is, moreover, probable that the time of 
 digestion of a particular meal (or rather the time in which it is expelled 
 from the stomach) varies not only in each person, but in different bodily 
 conditions of the same person. No exact statement on this point can thus 
 be made. But from such a consideration it is likely that the retarding 
 effect on digestion of food-accessories may be reduced to a minimum (e.g. in 
 persons of very vigorous digestion) by the great rapidity of natural digestion, 
 by increased rapidity of absorption, and by the activity of the muscular walls 
 of the stomach. The results of experiments in test tubes on the retarding 
 effect of food-accessories must not be too rigidly applied to particular indi- 
 viduals. These experiments show what might have taken place in certain, 
 perhaps abnormal, conditions, which are perhaps more interesting to the 
 physician than to the student of Public Health. 
 
 I. CONDIBIEKTS 
 
 Many food-accessories may be grouped together as ' condiments,' since 
 they are added to food as flavouring agents. These are such as mustard, 
 pepper, onions and vegetables allied to them, pimento, cloves, cinnamon, 
 nutmeg, caraway, cardamoms. Vinegar and common salt are also con- 
 
 ' Deutsche Archiv f. hlin. Med. Bel. xxxiii. 1883. 
 
480 HYGIENE 
 
 diments. The former has akeady been considered (p. 478), and the uses of 
 common salt have been frequently discussed. 
 
 Tiie condiments now under consideration — pimento, cloves, cinnamon, 
 &c. — owe their action as food-accessories to the aromatic oils they contain. 
 Oil of mustard and piperin, the active principle (resin) of pepper, have an 
 action similar to the aromatic oils. This action is manifold. The active 
 principles are first antiscj^tic (oil of mustard is powerful in this respect), so 
 that they serve the useful purpose when taken with a large mixed meal of 
 tending to prevent acid fermentation in the digestive tract. They are also 
 stimulants of tlie secretion of the ditjestive juices ; they certainly stimulate 
 salivary secretion, and thus reflexly (also probably directly) the secretion of 
 gastric juice. Thirdly, they stimulate peristaltic action. Taken in quantity 
 and by themselves, some of them (such as cloves and pimento) act as stimu- 
 lants to the nervous system ; but this is not an action associated, as a rule, 
 with their rule as food-accessories. 
 
 Fcppcr. — Black pepper is obtained from Piper nigrum ; white pepper is the 
 same decorticated. Both occur in commerce as ' seeds ' and in powder, and 
 the latter is liable to adulteration. In black pepper, free of water and of 
 sand, the amount of piperin and fixed oil is about 7"87 per cent., and the 
 amount of carbohydrate transformable into sugar is 49'33 per cent., not less. 
 This quantity of carbohydrate may be taken as a test of the purity of the 
 pepper. In white pepper, fixed oil and piperin is 8*24 per cent., and carbo- 
 hydrates are 64-95 per cent., of which 4(5-72 per cent, are starch. 
 
 Pepper is adulterated with olive stones, spent ginger, palm-nut powder, 
 rape seeds, and mustard husks.^ 
 
 Mustard is the seed of the Sinapis alba and Sinapis nigra. It is sold in 
 powder, which is liable to adulteration, being mixed with different kinds of 
 starchy flours (such as wheaten flour, barley flour, and linseed). These 
 adulterations are detected by the microscope (see pp. 451-454). Turmeric 
 is also added. 
 
 Pure mustard contains 0-66 per cent, of volatile oil, 35-42 per cent, of 
 fixed oil, and 13-95 per cent, of carbohydrates. The carbohydrates in 
 adulterated mustard are as high as 67 per cent, sometimes, the fixed oils in 
 such specimens being below 7 per cent.' 
 
 2. FOOD-ACCESSOEIES TaKEN AS LIQUIDS 
 
 The food-accessories taken in a liquid form may be divided into two 
 groups : (1) the liquids containing alcohol ; beer, wine, &c. ; (2) the liquids 
 containing the active principles caffeine or theobromine ; such as tea, cofiee, 
 Paraguay tea, cocoa. 
 
 1. Alcoholic Beverages 
 
 These owe their action as food-accessories chiefly to the ethylic alcohol 
 they contain ; and the effect of the difl'erent kinds of alcoholic drinks is, 
 broadly speaking, proportional to the amount of alcohol present, but not 
 completely so, since the majority of alcoholic drinks owe part of their efi'ect 
 to the action of aromatic substances and certain other principles, which will 
 be discussed afterwards. Although, therefore, the amount of alcohol jjresent 
 is important, yet the presence of these other principles must be considered 
 also in deciding the utility or non-utility of any given alcoholic drink. 
 
 The use of alcohol to mankind dates from time immemorial ; it is so 
 readily produced from sugars and starches by fermentation that its early dis- 
 
 ' See Konig, op. cit. Bd. i. pp. 731-735. Also Hassall's Food and its Adulterations. 
 2 See Konig, op. cit. Bd. i. p. 739. 
 
FOOD 
 
 481 
 
 ■covery by the human race is not to be wondered at. Its use, too, in tlie 
 world is so widespread that the manufacture of alcohoHc drinks has become 
 an important industry in civilised countries, and the tax on its production 
 an important addition to the revenue of these countries. It would be out of 
 place here to inquire whether this extended use of so powerful an agent is 
 ■of benefit to the social well-being of the community. The introduction of 
 alcoholic beverages into savage or semi-savage communities leads rapidly to 
 the extinction of the aborigines, and to the abuse of alcohol must be as- 
 cribed a large proportion of crime and immorality. A great mortality 
 attends the class of inebriates when they are attacked by infectious disease 
 .and by pneumonia or when they meet with severe accidents. The question, 
 however, for consideration here is the physiological effect of alcohohc 
 beverages, and what value they may possess in civilised communities. 
 
 Classification and Composition of Alcoholic Beverages. — For the sake of 
 convenience, and also according to the amount of alcohol they contain, 
 alcoholic drinks may be divided into (1) beers, (2) light wines (red, and white), 
 (3) sweet wines (champagne, port, sherry, &c.), and (4) spirits (brandy, 
 whisky, &c.). 
 
 1. Percentage Composition of Beers 
 
 - 
 
 Sp.gr. 
 
 Water 
 
 CO, 
 
 Alcohol. 
 
 Wt. per 
 
 cent. 
 
 Ex- 
 tract 
 
 Proteid 
 
 Sugar 
 
 Dex- 
 trine 
 
 Acid 
 (lactic) 
 
 Salts 
 
 Phos- 
 phoric 
 acid 
 
 Lager beer . 
 Bock beer . 
 Ale . 
 Porter 
 
 1-0162 
 1-0213 
 1-0141 
 1-0191 
 
 90-08 
 
 87-87 
 89-42 
 88-49 
 
 0-196 
 0-234 
 0-201 
 0-215 
 
 3-93 
 
 4-69 
 4-73 
 4-70 
 
 5-79 
 7-21 
 5-65 
 6-59 
 
 0-71 
 0-73 
 0-61 
 0-65 
 
 0-88 
 1-81 
 1-07 
 2-62 
 
 3-73 
 3-97 
 1-81 
 3-08 
 
 0-151 
 0-165 
 0-278 
 0-281 
 
 0-228 
 0-263 
 0-310 
 0-363 
 
 0-777 
 0-089 
 0-086 
 0-093 
 
 The sugar and dextrine in beer render it liable to fermentation, during 
 which free acids (acetic, &c.) are formed. The salts of beer consist of 
 chlorides and phosphates of potassium and sodium and of calcium. Besides 
 the alcohol, the most important principle present in beer is derived from the 
 hops used, especially the lupulin (see Physiological Action of Bbee, p. 486). 
 
 2. The light wines, and the sparkling, differ slightly in the amount cf 
 
 Percentage Composition of Light Wines 
 
 (Bed and White) 
 
 
 
 - 
 
 ho 
 P. 
 
 m 
 
 "o o 
 
 1 
 
 
 CD 
 
 a 
 1 
 
 s 
 
 ba 
 o 
 
 § « g 
 
 HI 
 
 
 
 w 
 
 W 
 
 o 
 
 W 
 M 
 
 Moselle .... 
 
 0-9964 
 
 7-99 
 
 2-24 
 
 0-790-72 
 
 0-031 
 
 
 
 0-175 0-036 
 
 0-0260-0681 
 
 Rhine wine 
 
 
 
 
 
 
 
 1 1 1 
 
 White 
 
 1-0005 
 
 8-00 
 
 2-60'0-8ll0-85 
 
 0-048 
 
 
 
 0-230 0-04610-020,0-0851 
 
 Eed . 
 
 0-9966 
 
 10-08 
 
 3-04 0-52 
 
 — 
 
 — 
 
 0-158 
 
 0-249 
 
 
 
 — 
 
 — 
 
 Prench wine 
 
 
 
 
 
 
 
 
 
 
 
 Eed . 
 
 0-9982 
 
 7-80 
 
 2-56 0-57'0-73;0-043 
 
 0-180 
 
 0-248 0-030[0-033 0-106 
 
 White 
 
 0-9963 
 
 10-31 
 
 3-03i0-66 0-97 
 
 — 
 
 — 
 
 0-250 0-032 0-038,0-098 
 
 Lower Austrian wine 
 
 
 
 
 
 
 
 
 
 White 
 
 0-9949 
 
 7-93 
 
 2-13 
 
 0-67 0-68 0-022 
 
 — 
 
 0-189 0-034 
 
 0-039'0-081 
 
 Eed . 
 
 0-9958 
 
 8-49 
 
 2-54 
 
 0-62 0-81 0-026 
 
 0-110 
 
 0-241 0-037 
 
 0-033 0-101 
 
 Hungarian wine 
 
 
 
 
 
 
 
 
 Eed . 
 
 0-9952 
 
 9-02 
 
 2-54 
 
 0-67 0-79 0-034 
 
 0-150 
 
 0-215 0-038 
 
 0-0240-091 
 
 White 
 
 0-9955 
 
 8-00 
 
 2-33,0-69 0-77 0-027 
 
 — 
 
 0-204 0-034 
 
 0-025 0-075 
 
 Italian wine . 
 
 
 
 10-63 
 
 3-44 0-52 1-45 0-013 
 
 
 
 0-2900-032 
 
 0-0190-115 
 
 Spanish wine 
 
 
 
 
 
 
 
 
 Eed. 
 
 — 
 
 12-31 
 
 3-53 0-49 1-09 
 
 — 
 
 0-220 
 
 0-610 0-027 0-221|0-242 
 
 Australian wine contains from 13 to 14 per cent, of alcohol by weight, 16 to 17 per 
 cent, by volume. 
 
 VOL. I. II 
 
482 
 
 HYGIENE 
 
 ethylic alcohol they contain, but much more in the quantity of ethers and 
 aromatic substances present. Red and white wines are obtained from 
 France, Germany, Austria, Hungary, Italy, and Spain, and also from Aus- 
 tralia. The best sparkling wines (champagnes) are from France. 
 
 3. Although champagnes differ from port and sherry in their effect, yet 
 they are best classed under the same heading as sweet wines, owing to the 
 amount of sugar they contain. 
 
 Percentage Composition of Sweet Wines 
 
 . 
 
 02 
 
 
 
 13 
 § 
 
 1 
 
 5 
 
 H 
 
 tlO 
 
 00, 
 
 Mineral 
 
 salts 
 
 pT h" 
 
 o 
 
 Champagnes 
 
 : ' i 
 
 
 I- j 
 
 Veuve Cliquot . 
 
 1-0565 10-20 19-75 0-60 1-13 
 
 0-25 
 
 17-52 0-514 0-12 0-016 0022 — 
 
 Koderer (carte 
 
 1 1 1 
 
 
 { 
 
 blanche) 
 
 1-0572 9-50 '20-24 0-70 0-97 
 
 0-26 
 
 18-50 1-514 0-12'o-012 0-017 — 
 
 Monopole . 
 
 1-0280 8-21 10-15 0-57 0-23 
 
 — 
 
 8-45 0-897 0-13 0-016 0-025 0-059 
 
 
 
 1 1 
 
 Nitrogen 
 
 1 1 1 
 
 Port wine 
 
 1-0081 16-69 
 
 8-05 0-40 0-43 
 
 0-027 
 
 5-82 — 0-23 0-0310-023 0-102 
 
 Sherry . 
 
 0-9932 17-45 
 
 3-98 0-45 0-52 
 
 0-027 
 
 2-12 — 0-38 0-0310-128 0-206 
 
 Madeira 
 
 1-0003 15-40 
 
 5-52 0-43 0-74 
 
 0-020 
 
 3-23 — 0-35 0-060 0-075 0-149 
 
 Marsala 
 
 1-0022 15-85 
 
 1 
 
 5-27 0-49 0-51 
 
 1 ! 
 
 0-037 
 
 3-53 — 0-38,0-029 0-1140-142 
 
 1 1 1 
 
 There are other constituents of these wines which are important, but 
 cannot be expressed in a table of percentage composition. These are 
 chiefly the ' compound ethers,' which give the 'bouquet ' to wine, although 
 this is also partly due to other aromatic bodies present. The compound 
 ethers are numerous, and consist mostly of oenanthic ether, but citric, malic, 
 tartaric, acetic ethers, and the ethers of higher members of the fatty acid 
 series are also present. The bouquet of wine is a permanent quality, as long 
 as the wine remains sound ; it is, however, developed by keeping for a 
 greater or less length of time. 
 
 The colouring matters of wine are, to a greater or less extent, deposited 
 on keeping, the wine thus becoming lighter in colour. All wines are acid, 
 and this acidity is due to free tartaric acid, and to the acid tartarate of 
 potassium (tartar) ; but other vegetable acids are also present. Tannin, 
 derived from the stalks and skins of the grape, is also present, rendering new 
 wine astringent ; it is deposited on keeping the wine, entering into combina- 
 tion with some of the organic bodies present. 
 
 On keeping wines, therefore, the chief chemical changes that occur are 
 the deposition of some tannin and colouring matter, the loss of a Uttle alcohol 
 and volatile acid. 
 
 4, Spirits contain the largest quantity of alcohol of all alcoholic beverages. 
 They are made by distilling fermented grapes (brandy), fermented molasses 
 (rum), fermented malt or malt and grain and other materials (whisky). The 
 greater part of the whisky is distilled in ' pot-stills,' in which the fire is 
 directly applied to the still containing the fermented liquid. ' Patent ' or 
 * silent ' spirits, which are largely used for blending potable spirits and for 
 fortifying wines, are made by exposing a subdi\'ided stream of the fermented 
 liquid to steam. 
 
 According to Bence Jones and Hassall (quoted by Parkes '), gin contains 
 from 49 to 60 per cent, of alcohol, with an acidity of 0-2 grain tartaric acid 
 per ounce, and 1 per cent, of sugar. It is usually made by adding juniper 
 
 ' 0^). cit. p. 319. As sold, however, gin may be 35 per cent, under proof, containing 
 usually about 30 per cent, of alcohol. 
 
FOOD 
 
 483 
 
 and other flavouring and sweetening agentss to patent spirits. The specific 
 gravity of brandy is 0-929 to 0-934 ; of gin, 0-980 to 0-944 ; of whisky, 0-915 
 to 0-920 ; and of rum 0-874 to 0-926. 
 
 Percentage Composition of Spirits 
 In 100 cubic centimetres are grammes — 
 
 - 
 
 Wuter 
 
 Alcoliol [ Extract 
 
 Acid= acetic 
 
 Salts 
 
 Common brandy 
 Cognac .... 
 Whisky' .... 
 Kum .... 
 
 (34-90 
 55-60 
 47-80 
 36-50 
 
 35-1 
 43-9 
 52-2 
 61-4 
 
 0-385 
 0-036 
 1-975 
 
 0-067 
 0-027 
 
 0-024 
 0-060 
 
 The basis of spirits is ethylic alcohol mixed with water ; but they also 
 contain alcohols higher in the series than ethylic (classed together as 
 * fusel-oil ' ), compound ethers, and empyreumatic bodies produced during the 
 process of distillation. The varying proportions of these ' bye-products ' 
 give spirits their individual characters, such as taste and aroma. In ' patent ' 
 spirits the chief higher alcohol present is propylic ; in spirits made from 
 molasses and from malt and grain, amylic and butylic alcohols are the chief 
 alcohols present. The aroma of brandy is due to compound ethers, cenanthic, 
 butyric, &c., and that of rum to butyric ether. One of the chief empyreu- 
 matic bodies in ' pot-still ' whiskies is furfurol, which is present to the 
 amount of 0-005 per cent. 
 
 When spirits are kept for several years they become ' mellowed.' The 
 change is usually considered to consist in a diminution of the higher alcohols 
 and the ethers ; but J. Bell has shown that in spirits kept in bond for six 
 years there is practically no change in the proportion of higher alcohols 
 and ethers present, and that the ' mellowing ' appears to be due to the em- 
 pyreumatic bodies, including furfurol, diminishing in quantity and altering in 
 quality so that they become less harmful.^ 
 
 The Physiological Action of Alcohol and of Alcoholic Beverages 
 
 The physiological action of alcohol, that is, of pure ethylic alcohol, is not 
 precisely the same as that of the alcoholic beverages which are in ordinary 
 use. These contain other bodies besides alcohol, which possess a physiological 
 action of their own, and one v/hich is not always masked by the presence of 
 ethylic alcohol. It will be well, therefore, to consider the action of alcohol first. 
 
 1. Physiological Action of Alcohol. — A great distinction must be drawn 
 between the effect of alcohol taken in dietetic doses, and the effect when 
 taken in excess. Although this is no doubt true, it is, however, difficult to 
 lay down any general rules as to what excess of alcohol really means. It 
 does not mean simply that alcohol is taken until it produces intoxication : 
 that is undoubtedly excess. But there are many individuals in whom a 
 moderate amount of alcohol, habitiially taken, produces severe pathological 
 effects. It may be said that these are weakly, although apparently healthy, in- 
 dividuals, and that this is a question more of medicine than of normal dietetics. 
 It is, however, a fact of great importance to bear in mind in discussing the 
 question of alcohol, that what is a dietetic dose for one individual may pro- 
 duce in another serious effects, if the habit is persisted in. 
 
 ' Whisky is usually under this strength, and as sold may be 14 to 30 under proof. 
 ^ Eeport on British and Foreign Spirits by a Committee of the House of Commons, 
 1891. 
 
 Ii2 
 
484 HYGIENE 
 
 The experiments of Austie, of Parkes and Count Wollowacz showed that 
 wdth strong, healthy men, ' accustomed to alcohol in moderation,' the amount 
 of alcohol which could be taken daily without doing harm was between one 
 and two ounces. If more than this quantity of alcohol were taken in the 
 day, alcohol was detected in the urine ; a sure sign that too much had been 
 taken. It is not quite accurate, however, to apply these results generally. 
 As has been noted already, owing to the idiosyncrasy of alcohol, one ounce 
 of absolute alcohol daily to some individuals would be a poison, the effect of 
 which would be aggravated if the amount of alcohol were translated into 
 terms of beer, claret, or other wines. The dietetic dose which might be 
 taken without harm by the majority of town livers is probably under one 
 ounce. Parkes' and Wollowicz' experiments were performed, it must be 
 recollected, on ' two powerful, healthy men accustomed to take alcohol.' 
 
 When taken into the stomach, dietetic doses of alcohol increase the 
 vascularity of that organ, producing a sensation of warmth, and also augment 
 the secretion of gastric juice. At the same time the appetite is excited. This 
 is no doubt the explanation of the taking of alcohol before meals ; a custom, 
 however, strongly to be deprecated, since the form of alcohol usually taken is 
 concentrated and liable to produce indigestion. The effect of alcohol on the 
 chemical process of digestion has already been discussed. Koberts, Bikfalvi, 
 and others have concluded that even when alcohol is present in the digestive 
 mixture to the extent of 10 per cent, it has no appreciable effect on the 
 fermentative changes occurring. It is otherwise, however, with alcoholic 
 beverages— beer, wine, &c. (p. 475 et seq.). 
 
 When taken for some length of time in excess, alcohol causes a great dis- 
 turbance of the digestive system. It causes loss of appetite, with a sense of 
 craving for alcoholic drinks, and a long train of dyspeptic symptoms. Morning 
 nausea and vomiting also appear, due to the fact that in most cases the 
 alcohol is largely taken in the evening, and the stomach remains partly full 
 during the hours of sleep. The prolonged use of alcohol also causes the 
 bowels to act two, three, or four times a day, and this is a common symptom 
 in habitual topers. To the effect of alcohol must be ascribed some cases of 
 severe gastric catarrh and the degeneration of the secretory glands of the 
 stomach observed by Wilson Fox. After being absorbed into the blood, 
 alcohol, according to Schmiedeberg,^ forms a compomad with h^emoglobm, 
 which more readily gives off' oxygen than haemoglobin itself. The result of 
 this is that alcohol lessens oxidation in the blood and the tissues. Most of 
 the alcohol taken is oxidised in the body, the products being excreted in the 
 urine. In dietetic doses, some of the alcohol may be detected in the expired 
 air, but it can be detected in the urine only when the dose is excessive. The 
 presence of alcohol in the urine is, therefore, to some extent, a chemical test 
 of an excess of alcohol having been taken. 
 
 Alcohol stimulates the heart, producing increased force and rapidity of the 
 cardiac beat. It thus tends to increase the blood-pressure by acting on the 
 heart, and to increase the flow of blood from the arteries into the veins. 
 The effect on the blood-pressure is, however, partly counteracted by a coin- 
 cident dilatation of the blood-vessels of the skin, which thus becomes flushed, 
 and tends to produce more sensible perspiration. 
 
 It is a question whether alcohol sensibly lowers the temperature of health, 
 and authorities are not agreed on this point. There is no doubt that in some 
 cases of fever alcohol does lower the temperature, especially in children ; and 
 in health it may be considered to tend to lower the body-temperature in two 
 ways, as Dr. Lauder Brunton points out, first, when given in medium doses, 
 ' Quoted by Brunton, Pharmacology, 3rd ed. p. 767. 
 
FOOD 485 
 
 by dilating the cutaneous vessels, whereby more blood comes to the surface 
 of the body, and thus more heat is lost by radiation and by means of the in- 
 creased perspiration ; second, when given in large doses, by lessening the 
 processes of oxidation in the body. But, although it is doubtful whether 
 alcohol lowers the temperature of health, there is no doubt whatever that it 
 tends to lower the natural resistance of the body against cold. When an 
 individual is exposed to intense cold for a long period, as in the Arctic 
 regions, he may derive some temporary comfort and sensation of warmth from 
 the taking of alcohol ; but his power of resistance to the intense cold is lessened, 
 and instances have been recorded where death has occurred under such con- 
 ditions during sleep. 
 
 The physiological effects of alcohol which have been considered are quite 
 subsidiary to its effect on the central nervous system, as there is no doubt that 
 it is for this effect on the brain that alcoholic beverages are so universally 
 taken by mankind. The first effect that alcohol has on the brain is that of a 
 stimulant, and it probably acts as such in two ways, namely, by the increasing 
 the circulation of blood through the brain, which is thus roused to greater 
 vigour, and by directly stimulating the nerve-cells of the nerve-centres. This 
 stimulant effect is observed chiefly after medium or dietetic doses, and its result 
 is seen in many individuals by an increase of mental and bodily activity, and 
 of acuteness of perception by the special senses. This beneficial physio- 
 logical effect is, however, soon replaced by poisonous symptoms if the dietetic 
 doses are too often repeated, or a large quantity of alcohol is taken at once. 
 For alcohol then becomes a depressant and paralyser of the central nervous 
 system, and symptoms of intoxication appear. This depressant effect is, as 
 Brunton points out, one of progressive paralysis. The higher centres of the 
 brain are first affected, then the lower. The perceptive centres are paralysed, 
 so that correct judgment is no longer possible, while the emotions are uncon- 
 trolled and thrown out of working gear, fits of boisterous hilarity and of 
 emotional depression being common symptoms. Speech becomes disordered, 
 and symptoms of inco-ordination, due probably to an effect on the cerebellum, 
 appear. The respiratory centre in the medulla then becomes affected, and 
 at this stage there is coma with stertorous breathing, while the action of 
 the heart still continues, even after respiration has stopped. 
 
 There can be no question that alcohol taken in sufficient quantities tc 
 depress the higher centres of the brain- does an infinite amount of harm. 
 The only question regarding the use of alcohol is whether when taken in 
 quantities sufficient to produce its stimulant effect on the brain it is beneficial 
 or not. 
 
 The serious symptoms and pathological changes produced by the use of 
 alcohol in excess may be summarised as follows : — 
 
 It delays digestion, causes catarrh and degeneration of the stomach, and 
 produces morning vomiting, looseness of the bowels ; symptoms referable to 
 the alimentary tract. It also causes congestion of the liver, audits prolonged 
 use ends in fatty degeneration or fibrosis (cirrhosis) of that organ, with its 
 attendant serious results. It seems doubtful whether alcohol can of itself 
 produce a fibroid condition of the kidneys. 
 
 Acute alcoholic poisoning produces coma and a peculiar form of delirium 
 with hallucinations terrible to the patient (delirium tremens), while to chronic 
 alcoholic poisoning may be ascribed a particular palsy, chiefly affecting the 
 extremities and caused by a peripheral neuritis. 
 
 The abuse of alcohol also lessens the resistive power to disease, especially 
 acute disease ; and such individuals die rapidly when affected with pneu- 
 monia and other acute affections. 
 
486 
 
 HYGIENE 
 
 2. Physiological Action of Alcoholic Beverages. — The physiological effect 
 of beer, N^nes, spirits, &c., partly depends on the amount of alcohol they con- 
 tain, and partly on other ingredients which have a physiological action of 
 their own. 
 
 It is not always possible to say what these ingredients are chemically ; 
 but there are some facts which are known and which are important. The 
 retarding effect of beers and wines on the chemical processes of digestion 
 has already been considered at length, and the cause, as far as is known, of 
 this retarding effect. It is now necessary to consider the other effect of 
 these alcoholic beverages, as such. 
 
 Many alcoholic drinks, especially potent spirits, owe their deleterious 
 effect to what may vaguely be described as ' impurities.' Some of these 
 impurities consist of alcohols higher in the series than ethylic (see p. 488). 
 Dujardin-Beaumetz and Audige have fomid experimentally that such alco- 
 holic drinks, with impurities, are more poisonous when given to animals than 
 the pm-ified spirits. The following table ' of the results of these observers 
 shows these results. Bad brandy, it will be seen, is more poisonous than 
 absolute alcohol in the proportion of 5'8 to 7"75. The smaller the poisonous 
 dose, the more deleterious the alcoholic beverage will be when drunk. 
 
 Poisonous Actiofi of Different Kinds of Alcoholic Prrparations 
 
 
 Average poisonous do?e per kilogramme of body- | 
 
 End of alcohol 
 
 weight of the dog, necessary 
 death in 24-36 hours 
 
 to produce 
 
 
 Spirits and brandies 
 
 Crude 
 
 Rectified 
 
 Grammes 
 
 Grammes 
 
 Grammes 
 
 Ethylic alcohol ..... 
 
 7-75 
 
 — 
 
 — 
 
 Spirit of wine of Montpellier 
 
 7-50 
 
 — 
 
 — 
 
 „ „ from pears . 
 
 7-35 
 
 — 
 
 — 
 
 „ „ from cider and from 
 
 
 
 
 '• marc of grapes .... 
 
 7-30 
 
 — 
 
 — 
 
 SiDirit from grain .... 
 
 — 
 
 6-96 
 
 7-25 
 
 ,, molasses and beetroot 
 
 — 
 
 6-90 
 
 7-15 
 
 Brandy from a public-house (ordinary 
 
 
 
 
 quahty) 
 
 7-00 
 
 — 
 
 — 
 
 Brandy from a public-house (inferior 
 
 
 
 
 _ ciuality) 
 
 5-30 
 
 — 
 
 — 
 
 Spirit from potatoes .... 
 
 — 
 
 6-85 
 
 710 
 
 „ „ (said to have been 
 
 
 
 
 ten times rectified) 
 
 — 
 
 — 
 
 7-35 
 
 Some of the undoubtedly deleterious effects of crude spirits must be as- 
 cribed to the presence of furfurol and other empyreumatic bodies, which 
 diminish and alter on keeping the spirit. These substances tend to derange 
 digestion and appear to have a profound effect on the nervous system. 
 
 Beer has an action of its own, probably dependent on the active prin- 
 ciple (lupulin) of the hops used in its manufacture. Lupulin is a depressant 
 to the nervous system. To many individuals, beer in small doses acts as a 
 soporific, and in excess it has a well-marked depressant action. This depres- 
 sion is probably due to the lupulin, and not to the potassium salts, as con- 
 sidered by Eanke. Taken for prolonged periods, beer, even in dietetic doses, 
 seems to lead to the deposition of fat in the body, and it probably produces 
 
 ' Taken from Brunton's Pharmacology, 3rd ed. p. 771. See original paper of Dujardin- 
 Beaumetz and Audige in Comptes Bendus, vol. Ixxxi. pp. 192-194. 
 
FOOD 487 
 
 ihis result by lessening oxidation and tissue metabolism in the body.^ Taken 
 in excess for long periods, beer is a ' gout-producer,' and one of the most 
 potent dietetic agents in the causation of that disease. 
 
 In wines, both light and sweet, the constituents, besides alcohol, 
 which are of importance are the vegetable acids and the compound ethers. 
 Beer also contains vegetable acids and their salts, and spirits contain com- 
 pound ethers ; while in all these are mineral salts, which are of service in 
 the economy. In beer and the sweet wines there is also a certain amount 
 of carbohydrate foodstuffs in the form of sugar and dextrine. According to the 
 amount of carbohydrate present, these alcoholic beverages, therefore, supply 
 valuable food to the organisms ; but not in an admixture, it must be re- 
 membered, in which it is necessary, or convenient, for the organism to assimi- 
 late it. 
 
 The vegetable acids, however, especially in Hght wines, undoubtedly play 
 an important role; since they make the wines antiscorbutic. The compound 
 ethers, besides aiding in giving the bouquet to wines and spirits, act on the 
 central nervous system as sedatives, and when taken in excess, as depress- 
 ants. An effect has been ascribed to them of stimulating the secretion of 
 pancreatic juice, and in this way wines and spirits containing them would be 
 of aid in digestion. It is true that Claude Bernard showed that sulphuric 
 ether acted in this way ; but no facts are as yet forthcoming to show that 
 the compound ethers present in alcoholic beverages possess this beneficial 
 .action. 
 
 The Dietetic Use of Alcohol 
 
 Alcohol, it is often said, is no necessity to the healthy individual. But 
 no hard-and-fast rule can be laid down on the subject. We have to take 
 into consideration the surrounding physical conditions of the individual, the 
 poverty or ease, the hard mental or bodily labour, all of which conditions 
 may surround healthy individuals. We have also to take into consideration 
 the colossal fact of the almost universal use of alcohol among nations, more 
 perhaps among civilised than among savage races. 
 
 To some individuals, alcohol in every shape or form is a poison, not 
 necessarily producing intoxication, but causing in course of time bodily 
 degeneration, with an increase of fatty and fibroid tissue in different parts 
 • of the body. 
 
 It has already been pointed out what effects alcoholic beverages taken in 
 dietetic doses have on the chemical processes of digestion and on the nervous 
 system ; effects which may not only not be deleterious, but be of service in the 
 conditions of life under which we live. Thus even the retardation of diges- 
 tion may be of benefit in aiding the complete assimilation of a large meal ; 
 and the stimulant action on the nervous system may restore the nervous 
 system to a healthy condition. This last action, indeed, may, in many cases, 
 be considered more as a question of therapeutics than of dietetics ; for the 
 condition of nervous system produced by over-work, in which alcohol in 
 small doses with meals is often beneficial, is a pathological and not a physio- 
 logical one. 
 
 There is no cogent evidence to show that alcohol is of service in increasing 
 bodily activity. The evidence adduced by competent observers is distinctly 
 against the use of spirits by soldiers in time of war. And when bodily exer- 
 tion has to be combined with judgment in directing one's action, alcohol, by 
 
 ' The amount of carbohydrates present in beer does not account for the deposition 
 of fat. 
 
488 HYGIENE 
 
 blunting the judgment, may do great harm. There is no doubt, however^ 
 that alcohol is of ser\'ice in conditions where there is deficiency of food ; for 
 it enables, for a short period it is true, bodily vigour to be maintained on an. 
 insufficient diet. 
 
 11. Beverages containing Alkaloids 
 
 Tea, cofifee, Paraguay tea, guarana, and cocoa come under this head. The 
 first four have as their active principle the alkaloid theine or caffeine ; cocoa 
 contains theobromine, and the effect of these beverages in their dietetic use 
 is chiefly due to these alkaloidal principles. 
 
 Caffeine or theine is chemically trimethylxanthine or methyltheobro- 
 mine, C8H,oN40o. Theine, the alkaloid from tea, is considered as identical 
 with caffeine, and is commercially sold as caffeine. It is not, however, accord- 
 ing to May, quite identical with caffeine in its physiological action. Caffeine 
 exists in coffee beans in about 0'5 to 1'24 per cent., in tea from 2 to 4 per cent., 
 and in guarana about 5 per cent., and in Paraguay tea in from 0'48 to 1"85 
 per cent. 
 
 In its physiological action, it plays the o'ole of a cerebral stimulant,, 
 exciting (but not necessarily over-exciting) the brain to continued activity 
 and stimulating muscular activity. Both coffee and tea have these physio- 
 logical effects. Caffeine, moreover, stimulates respiration and increases the- 
 blood-pressure ; but in its further effects (as from an overdose) it makes the 
 pulse more frequent and in some cases intermittent. Caff'eme is also a 
 diuretic. Both tea and coffee may also have this action on the pulse and 
 urine. The good effects of tea and coffee are evident from what has been 
 said ; they stimulate the brain and restore muscular activity. 
 
 Their evil effects are partly seen in symptoms of disorder of the digestive 
 tract and partly in those of a disordered nervous system. Thus tea and 
 coffee indulged in to excess produce dyspepsia, chiefly of the acid form. 
 Their effect in delaying the chemical processes of digestion has already been 
 discussed (p. 474 et seq.). The disordered digestion arising from the abuse of tea 
 and coffee has been ascribed to the tannin present in the infusion. There is,, 
 however, no e\ddence of this. It is not the tannin that delays the digestion,, 
 as Roberts has shown; and most of the symptoms of tea and coffee abuse 
 are those of delay of digestion, i.e. of food remaining undigested in the 
 stomach. Caffeine is itself a gastro-intestinal irritant, and coffee in some 
 individuals produces diarrhoea. It is not, however, clear what constituent 
 of tea and coffee is the active agent in producing dyspepsia. 
 
 On the side of the nervous system coffee and tea may lead to sleeplessness 
 and restlessness ; in some people such symptoms are noticed even if the 
 beverages are not taken to excess. Tea, moreover, may produce muscular 
 tremor. 
 
 Some eff'ect must be ascribed to the aromatic principles present in tea and 
 coffee ; these no doubt greatly add to their consumption or have the same 
 physiological effect as the aromatic principles already discussed (p. 474). 
 
 Theohromine, the active principle of cocoa, is closely related to caffeine ; 
 it is dimethylxanthine, C7H8N4O2. Only traces of caffeine are found in 
 cocoa. 
 
 The physiological action of theobromine is chiefly exerted on the muscular 
 system ; it is a greater restorer of muscular activity. Its effect on the nervous 
 system is not well defined. 
 
 Cocoa in infusion has but Httle physiological action, owing to the small 
 amount of theobromine present. In its raw state, cocoa is largely composed, 
 of fat and to a less extent of carbohydrates ; and even in the ' prepared ' 
 
FOOD 480 
 
 cocoas, fat is present in large amount. Cocoa must therefore be considered 
 as a fatty food, and thus differs markedly from tea and coffee. 
 
 Tea 
 
 Tea consists of the dried leaves of Camellia thea. It is grown in China^ 
 India, and Ceylon, and from these countries the European supply is derived. 
 It is also grown in Japan, the tea produced being green in colour. Black tea 
 is the form usually employed in Europe, the use of green tea having greatly 
 diminished. Green tea contains more theine, ethereal oil, and tannin than 
 black tea. 
 
 The tea as sold consists of the dried leaves, which are curled ; they may 
 be uncurled by placing in hot water and unrolling, and then placing on a 
 slip of glass. The shape is ovate and pointed, with serrated margin almost 
 to the stalks. The length varies somewhat. In all teas stalks will be found. 
 
 The venation of the leaves is characteristic. The large veins do not reach 
 the border of the leaf, but turn in towards the mid-rib. 
 
 Composition of Tea. — The average percentage composition of black tea is 
 9*51 of water, 3*58 to 4*70 of theine, 24*50 of nitrogenous substances, 0'68 
 of ethereal oil, 6"39 of fat, wax, chlorophyll, and resin, 6"44 of gum, 
 dextrine, &c., 15"65 of tannin, 16"02 of pectin, 11-58 of cellulose, and 5*65 
 of ash (Geissler). 
 
 "Wynter Blyth gives, as the average composition of black tea, 6'44 per 
 cent, of water, 1'43 of theine, 35-61 of ' extract,' 6-75 of gum, dextrine, &c., 
 and 6-72 of salts, of which 3-29 are soluble, 0*70 consists of silica, and 1-44 
 of potassium. The salts of tea consist, besides those of silicon and potassium, 
 of sodium, magnesium, iron, and manganese, combined with phosphoric acid, 
 chlorine, and carbonic acid. 
 
 Infusio7i of Tea. — All the constituents of tea are not soluble in hot 
 water ; but most of the soluble substances are dissolved in the infusion as 
 made. In 100 parts of tea (air-dried), 33"64 parts are soluble in water, con- 
 sisting of 12-38 parts of nitrogenous substances (including theine), 17*61 
 parts of nitrogen-free substances, 3-65 parts of salts, of which 2-10 parts 
 consist of potassium salts. ^ 
 
 Tea infused, as it ought to be, for the period of three minutes only, does 
 not contain so large a proportion of soluble matter. 
 
 Adulterations and Examination of Tea. — Good tea consists mostly of 
 whole leaves of the characteristic structure previously described. Other 
 leaves containing tannin are mixed with tea as adulterations ; such as the 
 willow, oak, sloe, hawthorn, elder, beech, and (in China) the Camellia 
 sasanqua and Chloranthus inconspicuus. None of these, except the sloe, 
 willowfand the Camellia sasanqua and Chloranthus could be mistaken for tea 
 leaves. The sloe is distinguished by its obovate shape as contrasted with the 
 ovate, acute tea leaf ; the willow leaf is characterised by its irregular serration.^ 
 
 Tea is sometimes mixed with insoluble matter, such as catechu, sand, and 
 magnetic oxide of iron. The last two fall to the bottom of an infusion and 
 are readily detected. 
 
 In the examination of tea, an infusion ought to be made to judge of the 
 aroma and astringency. The aroma is slight in old or adulterated tea. 
 
 The total soluble matters are estimated by infusing a weighed quantity with 
 a large excess of distilled water, and evaporated to dryness on a water-bath, 
 
 1 This large proportion of potassium salts in the infusion may account for part of 
 the depression following the abuse of tea. 
 
 * For further information on these points see Hassall, op. cit. 
 
490 HYGIENE 
 
 The ash ouglit not to be above 8 per cent, in air- dried tea : it is usually 
 about o"5 to 6 per cent. 
 
 Tlie amount of tannin may be estimated by infusing a weighed quantity 
 of tea and precipitating the tannin with gelatine : 100 parts of the dried 
 precipitate is equal to 40 parts of tannin.^ 
 
 Coffee 
 
 Coffee is obtained from the seeds of Caff'ca arabica, obtained from various 
 parts of the tropics. The principal varieties are Mocha, Ceylon, and West 
 Indian, all differing somewhat in flavour. 
 
 The compositon of mn-oasted coffee beans is 11-23 per cent, of water, 
 12'07 per cent, of nitrogenous substances, 1'21 per cent, of caffeine, 12-27 per 
 cent, of fat, 8-55 per cent, of sugar and dextrine, 33-79 per cent, of tannin and 
 other nitrogen-free bodies, ^ 18-17 per cent, of cellulose, and 3-92 per cent, of 
 salts, which consist chiefly of potassium and phosphates. This is the average 
 composition. In some specimens of cofl'ee, the percentage of cafl'eine is higher, 
 and that of cellulose may be from 27-5 to 34-4 percent. 
 
 In the roasting of coffee, the caffeine is not destroyed, but dissociated from 
 its combination with the tannin : the sugar and dextrine are changed into 
 caramel, while some of the cellulose is charred, and gases of combustion are 
 given off" and water evaporated. At the same time the aroma is developed. 
 The average composition of roasted coffee is 1*15 per cent, of water, 13-98 per 
 cent, of nitrogenous substances, 1-24 per cent, of caffeine, 14-48 per cent, of 
 fat, 0-66 per cent, of sugar, 45-09 per cent, of other nitrogen-free bodies, 19-89 
 per cent, of cellulose and 4*75 per cent, of salts. 
 
 Infusion of Boasted Coffee. — For the making of good coffee (an art 
 practically unknown in this country) the berries must be ff'eshly roasted and 
 gi'ound. The percolator used must be warmed, and one large teaspoonful 
 of the ground coffee for each breakfast-cupful placed in it. 
 
 A sufficiency of boiling water must then be added and allowed to flow 
 through ; and after it has flowed through, it must be returned to the per- 
 colator again ; twice is, as a rule, sufiicient to obtain a good infusion. 
 Boiling the infusion destroys the aroma. One hundred parts of coffee yield 
 to boiling water 25-50 parts of soluble matter, consisting of 3-12 parts of 
 nitrogenous substances, 5-18 parts of oil, 13-14 parts of non-nitrogenous sub- 
 stances, and 4-06 parts of salts. 
 
 The physiological action of coffee and of its active principle, caffeine, 
 has already been discussed (p. 488). 
 
 Adulterations of Coffee. — The ground coffee is adulterated with chicory 
 and with several starch -containing grains, the cereals, beans, maize, and 
 potatoes, and with sugar. 
 
 The composition of chicory varies greatly from that of coffee. In 100 
 parts, there are in roasted chicory 13-16 parts of water, 6-63 of nitrogenous 
 substances, 2-74 parts of fat, 17-89 parts of sugar, 41-42 parts of other non- 
 nitrogenous bodies, 12-07 parts of cellulose, and 6-19 parts of salts. The 
 large amount of sugar in roasted chicory as compared with that in roasted 
 coffee (17-89 per cent, in the former and 0-66 per cent, in the latter) is a 
 point of distinction, as well as the larger proportion of salts (6*19 and 4*75 
 per cent.) 
 
 Chicory may also be distinguished by the fact that the roasted beri'y sinks 
 
 ' For the process for the separation of theine see Eichter's Organic Chemistry, p. 349 
 English translation, 1886. 
 
 - The proportion of tannin is about 5 per cent. 
 
FOOD 491 
 
 in water, while the freslily roasted coffee berry floats, and by the microscopical 
 examination which shows in chicory the dotted ducts.^ The presence of any 
 of the varieties of starch is shown by the blue colour given to a dilute infusion 
 with solution of iodine and by a microscopical examination. 
 
 Acorns and parsnip roots are sometimes used to adulterate ground coffee. 
 
 Paraguay Tea — Guarana 
 
 Paraguay tea {mate) is obtained by roasting the leaves of Ilex para- 
 guayensis and exposing them to the action of the sun. It is used in 
 Paraguay and other parts of South America. It contains 3-87 per cent, 
 of proteids, 0-48 per cent, of theine (1*48, according to Byasson), 2 to 
 4-5 per cent, of fat, resin, and chlorophyll, 2-38 per cent, of sugar, 4-1 per 
 cent, of tannin, and 3'92 per cent, of salts : 24 per cent, of the solids is 
 soluble in water. 
 
 In infusion, it has an action similar to other caffeine-containing beverages, 
 but is more apt, it is said, to cause digestive disturbance. 
 
 Guarana is obtained by roasting the seeds of Patdlinia sorbilis. It con- 
 tains a large proportion of caffeine, 5 per cent. It has been used in migraine 
 with some success. 
 
 Cocoa 
 
 Cocoa is prepared from the seeds of the Theohroma cacao. Cocoa beans 
 consist of 7'11 per cent, of water, 0*45 per cent of theobromine, 51'78 per 
 cent, of fat, 8"33 per cent, of starch, and 3*60 per cent, of salts. When charred 
 and burnt, some of the starch becomes changed into dextrine and sugar. The 
 beans then have the following composition : 5'58 per cent, of water, 14*13 
 per cent, of nitrogenous substances, 1'55 per cent, of theobromine, 60'09 per 
 cent, of fat, 8"77 per cent, of starch, 13"91 per cent, of other nitrogen-free 
 bodies, 3*93 per cent, of cellulose, and 3*45 per cent, of salts. 
 
 The cocoa found in commerce is ' prepared : ' a part of the fat is removed, 
 and in most cases starch and sugar are added. An average composition of 
 such preparations is the following : — 6*35 per cent, of water, 21'50 per cent, of 
 nitrogenous substances, chiefly proteid,, 1*82 per cent, of theobromine, 27'34 
 per cent., of fat, 2'53 per cent, of sugar, 15'17 per cent, of starch, 16*48 per 
 cent, of the non-nitrogenous bodies, 6*44 per cent, of cellulose, and 5'19 
 per cent, of salts. 
 
 Cocoa is, therefore, a fatty and a proteid food, and to some extent a carbo- 
 hydrate food also. It has but little stimulant action, but the small amount 
 of theobromine present no doubt acts as a restorer of muscular activity. The 
 cocoa of commerce is largely adulterated with the different starches of the 
 cereals, potato, arrowroot, &c., the presence of which is readily detected by 
 the microscope. Sugar is also added. Mineral adulterations are detected by 
 chemical tests. 
 
 ^ Fox further information on this point see Hassall, op. cit. 
 
THE mSPECTION OE MEAT 
 
 BY 
 
 E. W. HOPE, M.D., D.Sc. 
 
 .ASSISTAin; MEDICAl OFFICER OF HEALTH 
 IBCT-UBBK ON PUBLIC HEALTH, UNIVERSITY COLLESB, LIVERPOOI. 
 
THE INSPECTION OF MEAT 
 
 The Legislature imposes important duties and powers upon the duly ap- 
 pointed officials of sanitary authorities in respect to the examination of 
 meat. The Acts in which these duties and powers are defined are sections 
 116, 117, 118, and 119 of the Public Health Act and the Sale of Pood and 
 Drugs Act. In the great majority of instances action is taken under the 
 first-named Act, but occasions sometimes arise when it becomes necessary to 
 proceed under the latter Act : for example, in the fraudulent substitution of 
 the flesh of one animal for that of another.^ Section 6 of the Sale of Food 
 and Drugs Act provides that ' no person shall sell to the prejudice of the 
 purchaser any article of food which is not of the nature, substance, and 
 quality demanded by such purchaser, under a penalty not exceeding twenty 
 pounds.' lit is important to bear in mind that in proceeding under this Act 
 all its requirements must be carefully observed : the article must hQ purchased 
 by the officer or his agent, and must be submitted to the analyst,^ whose 
 certificate specifying the result of the analysis must be produced in court ; 
 moreover, the person purchasing the article must, on the completion of the 
 purchase, forthwith notify to the seller his intention to have the article 
 analysed by the public analyst, and offer to divide it into three parts to be 
 then and there separated and sealed up, one to be delivered to the seller (if 
 he so wish), one to be given to the analyst, and one to be retained for future 
 comparison. A person refusing to sell any article to any officer is liable to a 
 penalty of 101. 
 
 The ordinary procedure under the above-named sections of the Public 
 Health Act is different from the foregoing. Section 116 of this Act directs 
 that * any medical officer of health or inspector of nuisances may at all reason- 
 able times inspect and examine any animal, carcase, meat, &c., exposed for 
 sale or deposited in any place for the purpose of sale, or of preparation for 
 sale, and intended for the food of man, the proof that the same was not ex- 
 posed or deposited for any such purpose, or was not intended for the food of 
 man, resting with the party charged ; and if any such animal, carcase, meat, 
 &c., appears to such medical officer or inspector to be diseased, or unsound, 
 or unwholesome, or unfit for the food of man, he may seize and carry away 
 the same himself or by an assistant, in order to have the same dealt with by 
 a justice.' It is not necessary for the officer to give notice to the owner of 
 the goods seized, but it is customary to do so if the owner can be found. 
 
 Section 117 says that ' if it appears to the justice that any animal, car- 
 case, meat, &c., so seized is diseased, or unsound, or unwholesome, or unfit 
 for the food of man, he shall condemn the same, and order it to be destroyed 
 or so disposed of as to prevent it from being exposed for sale or used for the 
 food of man ; and the person to whom the same belongs or did belong at the 
 
 * An importer of large quantities of tinned meat was recently convicted and fined at 
 the Liverpool Police Court for selling tins labelled ' Superior Eoast Mutton,' vrhich con- 
 tained beef with mutton fat poured over it ; the difference in price per 2-lb. tin between 
 the beef and mutton was threepence. 
 
 '^ Omission to do this has resulted in the dismissal of a summons. 
 
496 HYGIENE 
 
 ■time of exposure for sale, or in wliose possession or on whose premises the 
 same was found, shall be liable to a penalty not exceeding 201. for each 
 j)iece, or at the discretion of the justice, without the infliction of a fine, to 
 imprisonment for a term of not more than three months.' 
 
 It is a question whether it is a necessary requirement that the justice 
 should liimself inspect the article ; in some places this is done, but in others 
 the justice does not himself inspect, but adjudicates upon these cases as he 
 does upon others, viz., upon the evidence brought before him. The late 
 Mr. Eaffles, stipendiary magistrate of the City of Liverpool, whose experience 
 was probably unique, would never inspect meat, declining, as he said, to act 
 both as judge and witness. Another sound reason why the fitness or unfit- 
 ness of meat for food should be decided upon the evidence of those practically 
 acquainted with the details of the question, rather than by the personal 
 inspection of the justice, is the admitted necessity of special knowledge to 
 enable a correct opinion to be arrived at in the matter. 
 
 By section 118 of the same Act a penalty is imposed for hindering or 
 obstructing an officer, and section 119 empowers a justice to grant a warrant 
 to an officer to enter any premises, to search the same, and to seize any 
 article therein which he may deem unsound, unwholesome, or unfit for the 
 food of man, in order that it may be dealt with in the manner described. 
 
 Characteristics of Sound Meat. — Good meat is firm and elastic to the 
 touch, not pitting or crackling on pressure ; juicy, but not wet ; the fat, when 
 sufficient time has elapsed for the carcase to cool and set, is firm, the suet 
 hard — containing no jelly or watery juice — is free from blood stains, and in 
 colour varies from creamy white to deep yellow ; the pleura and peritoneum 
 are free from adhesions or staining. The flesh should be that of a well- 
 nourished animal — not attenuated ; the colour should be uniform, without 
 brown or discoloured patches. Good beef is of a bright colour, marbled with 
 fat ; the flesh of the calf is always paler and less firm to the touch ; mutton 
 is a dullish red, firm, the fat hard, usually white, but a marked yellowness is 
 consistent with wholesome meat. The flesh of the pig is pale, and less firm 
 to the touch ; the fat also is soft ; the carcase should be plump, the skin 
 smooth, not setting in folds or wrinkles. In all cases, special attention 
 should be paid to the connective tissue about the flanks and shoulders and 
 diaphragm, and below the fat of the kidneys ; wetness, oedema, tubercle, or 
 other evidences of disease may be found here ; the thoracic and abdominal 
 parietes should be examined for evidence of stripping, staining, or other 
 abnormal condition ; the odour of the carcase should be sweet, and a skewer 
 plunged into the flesh should have no unpleasant smell on withdrawal. 
 
 The age of animals is important. Young animals are recognised by the 
 condition of the bones and their cartilages ; with advancing age, ossifica- 
 tion becomes more complete, the bones are firmer and more compact, while 
 the cartilage diminishes. Newly-born, or still-born calves have a watery 
 appearance of flesh ; the fat is tallowy, and the hoofs are yellow, readily in- 
 dented with the nail, and show that the animal has not walked on them. 
 In old animals the proportion of fat to lean lessens ; bull-beef is firmer and 
 coarser than ox-beef, darker in colour and less juicy ; in the heifer the udder 
 is not fully developed, and contains much fatty tissue ; in the old cow which 
 has had several calves it is loose, spongy, and brownish in colour ; the fat 
 of the old cow is deficient, and the flesh coarser in texture and darker than 
 that of the heifer, whilst the bones are completely ossified. 
 
 Wherever possible, the viscera should be examined, and a knowledge of 
 human pathological processes will always stand the medical officer in good stead ; 
 when examining carcases the general features of sound meat must be carefully 
 
THE INSPECTION OF MEAT 497 
 
 borne in mind, and due weight given to the aggregate deviations from thenormal 
 standard. It may be laid down as a broad general rule, that in all chronic 
 toasting diseases there is emaciation, often to an extreme degree; the flesh 
 is pallid in appearance and, together with the connective tissue, may bo infil- 
 trated with serum ; the fat and visceral connective tissue are also wet and 
 flabby, and the fat will not set ; occasionally the pleura is found to have 
 been stripped off from the ribs to remove evidence of pulmonary disease. 
 In aciite inflammatory diseases the affected organ will present the ordinary 
 signs of inflammation, but if the animal be slaughtered at an early stage ot 
 the disease, and is properly bled and dressed, the flesh is usually normal and 
 sound ; if, however, the animal has not been killed until when moribund, or 
 if the disease has made progress, the carcase will be found to be red and 
 congested from imperfect bleeding ; it will not set properly, and the flesh will 
 be dark, dry, and sticky, and frequently giving off an unwholesome odour of 
 drugs which can be best detected by plunging a skewer deeply into the flesh 
 and observing the smell. 
 
 The appearance of the carcase is dependent to a considerable extent upon 
 the manner in which it is dressed ; a butcher who is a good hand at his trade, 
 and who is clean, careful and prompt in killing and dressing cattle, will 
 secure a better wholesale price than an indifferent man. In all cases the 
 dressing should be completely finished before the carcase sets ; on no account 
 should the intestines remain in longer than is necessary. In dressing cattle, 
 when the animal has been bled, the hide is partially removed from the 
 abdomen and hind quarters, and the animal is then hauled up by the hind 
 limbs and disembowelled; the hide is then carefully removed from the 
 carcase, so as to leave the fat on the back as smooth as possible. The carcase 
 is then spht with saw and cleaver, the divided brisket being bent back on 
 either side and secured with hooks over the flat ribs, in order that when set 
 the part shall be thicker and more convenient for sale. Care is taken to 
 keep the meat clean, in order to lessen or prevent the necessity for washing. 
 
 In dressing sheep, the skin is partially removed immediately the animal 
 is bled ; the carcase is then suspended by the hind extremities, disembowelled, 
 and the skin entirely removed ; a stick, the extremities of which are fixed in 
 the abdominal walls, is passed across the back of the animal, so as to expose 
 the inside of the sheep. The fore-limbs are not allowed to set in the drooping 
 position they naturally assume, but are fastened up with skewers so as to set 
 in the thickened and contracted shape most convenient for sale, and which 
 is familiar to everyone. 
 
 Lambs are treated in the same manner, but in the early part of the 
 season the skin is not entirely removed, in order that the flesh may not 
 become dry ; the feet also are left on. In dressing lambs, a piece of omental 
 fat is spread out on each hind quarter, and a piece of mesenteric fat, carefully 
 removed from the intestines, is sold with each fore-quarter. 
 
 Calves are dressed in a similar fashion to lambs. Pigs, after being bled, 
 are scalded, scraped, and disembowelled in the manner already referred to ; 
 they set with a smooth and plump surface. 
 
 All ill-dressed carcases should attract attention, since diseased animals, or 
 those killed when moribund, are frequently dressed hurriedly and by unskilled 
 hands, and present a slovenly appearance. At the same time, it must, be 
 mentioned that in some parts of the kingdom cattle are always ill-dressed, 
 frequently packed whilst warm, and despatched to market ; these are not 
 attractive in appearance, but may be perfectly sound. 
 
 Befrigerated Meat is imported into this country in immense quantities, 
 and usually in prime condition, and it keeps well on exposure. Beef is im- 
 
 VOL. I. K K 
 
498 HYGIENE 
 
 ported in quarters, wrapped in muslin cloths ; the fat is sometimes stained 
 with the meat juice, which gives it a dullish red appearance ; carcases of 
 sheep are imported entire, usually wrapped in muslin cloths. When com- 
 mencing,' to thaw, both beef and mutton become wet on the surface, and if 
 again placed in the refrigerator, and afterwards again thawed, present a wet 
 and unsightly appearance which must not be confounded with oedema, since 
 the flesh is sweet and good, notwithstanding its appearance. 
 
 Some important conditions affecting the flesh of animals used for food 
 have to be considered. Among parasitic diseases, the most important 
 afi'ecting the sheep is occasioned by the presence in the liver of the Distoma 
 hepaticum, coiiimonly known as the fluke. The parasite in question is 
 somewhat sole-shaped, about i uicli to 1 inch in length, and is found in the 
 bile-ducts in very varying numbers. A few of these creatures may be met 
 with in otherwise perfectly sound sheep, and exercise no prejudicial effect 
 whatever upon the flesh, but as their numbers increase, important structural 
 changes take place from pressure and obstruction to the flow of bile ; jaundice 
 and dropsical swellings set in, together with diarrhoea and falling oil' of the 
 hair ; emaciation is rapid, and so extreme, as to give rise to the common name 
 of the ' rot ' which butchers aj)ply to the disease. The aflected liver should 
 in all cases be destroyed, and the carcase should be condemned if it be 
 deteriorated. The disease is met with in all parts of the country, but more 
 especially in damp and wet localities, and during the long-continued preva- 
 lence of wet weather ; the eggs and the embryo are developed in. water, and 
 hence wet seasons are conducive to the spread of the disease. 
 
 Canurus cerebralis, the cystic form of the Tcenia ccenurus of the dog, is 
 met with in the brain of the sheep and ox, producing the disease known as 
 ' turnsick,' ' sturdy,' or ' gid.' In the early stages no material effect is pro- 
 duced upon the flesh, but with the advance of cerebral symptoms the animal 
 emaciates, the flesh deteriorates, and becomes ultimately in-nutritious and 
 valueless as an article of food. In all cases the parasite should be de- 
 stroyed. 
 
 The Strongylus filaria are liable to be met with in the lungs of the sheep, 
 and ultimately produce wasting of the tissues. 
 
 Parasitic animal organisms, by which the human being may be attacked, 
 are of great importance. Two of these may reach him through the medium 
 of the flesh of the pig. 
 
 The Tceniadoi pass through two distinct phages in two different hosts : the 
 encysted state of the Tcsnia solium of man constitutes the Cysticercus celluloses 
 which commonly affects the pig, in which it gives rise to the disease known 
 as ' measles.' The ' measly ' pork contains the cysticerci in greater or less 
 abundance, lodged chiefly in the muscular tissues, voluntary or involuntary, 
 also in the liver, brain, connective tissues, and serous membranes ; they are 
 not met with in the fat. The parasite in this stage consists of the scolex 
 and its cystic surrounding ; the cyst averages the size of a pea, and is em- 
 bedded between the muscular fibres, from which it can be readily removed 
 and the crown of booklets demonstrated. The parasite is difficult or impos- 
 sible to detect during the life of the animal, but the cysts are readily visible 
 as soon as the animal is killed and opened ; calcareous degeneration of the 
 cysts sometimes takes place, a condition which is readily noticeable. In every 
 case of this affection, the carcase of the animal should be condemned and 
 destroyed ; it is both prudent and desirable to treat hams and bacon in which 
 the condition may be found in a similar manner, notwithstanding that the 
 processes of curing and cooking may destroy the parasite. 
 
 Trichina spiralis is a still more formidable parasite, and gives rise to the 
 
THE INSPECTION OF MEAT 490 
 
 disease known as trichinosis. The parasite attacks other animals besides the 
 pig, but the occurrence of trichinosis in man is usually due to the consump- 
 tion of the flesh of an infected pig, commonly, it is believed, in an imperfectly 
 cooked state. The trichina are small thread-like worms, coiled in minute 
 ovoid cysts within the muscular fibres : each cyst contains one immature 
 trichina, which is liberated when the capsule is dissolved by the processes of 
 digestion ; the liber&ted trichinre develop rapidly : the female is amazingly 
 prolific, ova are formed and impregnated, and the young find their way into 
 all parts of the body of the host. They are found in the greatest extent in 
 the voluntary muscles, but have also been met with in the fat ; the diaphragm 
 and inter-costal muscles are said to be favourite sites. 
 
 Careful examination is necessary for the detection of the trichinas : close 
 inspection reveals a speckled appearance, but thin sections of the pork should 
 be immersed for a few minutes in liquor potassse, until the muscle becomes 
 translucent, washed, and afterwards examined with a lens or low power of 
 the microscope, when the coiled-up worm will be seen ; the cysts are occa- 
 sionally gritty from the presence of carbonate of calcium. 
 
 All the flesh of an infected animal should be destroyed. 
 
 Dr. Carsten describes as follows the energetic measures adopted in the 
 Netherlands in connection with an outbreak of trichinosis, and which resulted 
 in the complete extinction of the disease : — ' A Eoyal decree was issued pro- 
 hibiting the removal of pigs and pig manure from an infected district, and a 
 special veterinary inspector was stationed temporarily in the neighbourhood 
 as supervisor ; the local authorities instituted a strict search for trichinae, 
 ordering that all pork before consumption be submitted for inspection to a 
 competent committee appointed for that purpose ; that all pig-yards be over- 
 hauled, and that wherever any trace of trichinae be found, the infected swine, 
 and all vermin found in the neighbourhood thereof be killed, and, together 
 with the offal, consumed by fire.' * These measures proved quite effectual. 
 
 Tuberctdosis. — Cattle, pigs, poultry, and rarely sheep, are all liable to be 
 affected with tubercle, but it is in cattle, and more especially milk-cows, that 
 tuberculosis is met with. The flesh of the tuberculous animal is affected in 
 varying degrees, and much diversity of opinion exists as to the stage at which 
 the flesh should be condemned. Opinion is practically unanimous that in 
 advanced stages of tuberculosis the consumption of the flesh should be pro- 
 hibited, not that every observer is prepared to state that its consumption 
 would give rise to specific inoculation, but on the general grounds that the 
 flesh is so deteriorated as to possess no longer the nature, quality, and pro- 
 perties of wholesome nutritious meat. Thus far the position is a simple one, 
 and any practical butcher can recognise when the disease has advanced so 
 far as to prejudice the quality of the meat. 
 
 Tuberculosis is known by various names, such as * grapes,' ' wasting,' 
 ' pearls,' and the like, the first term being perhaps the commonest, from the 
 fancied grape-like arrangement of the nodular tuberculous masses frequently 
 found adhering to the chest-walls. The most common seats of the disease 
 are the lungs, pleurae, and other serous membranes ; the liver, lymphatic, and 
 other glands are often affected, sometimes the marrow and the nervous 
 system, and it is also alleged that bacilli have been found in the flesh. The 
 extent of the local lesions varies widely ; they may be limited to a single 
 nodule, or almost the entire organs mentioned may be invaded, their tissues 
 destroyed by caseous or calcareous masses or by liquefying pultaceous matter. 
 Grape-like aggregations of various sizes attached to serous membranes are 
 
 ' Communicated to the Seventh International Congress of Hygiene and Demography. 
 
 kk2 
 
iOO HYGIENE 
 
 ■extremely common, and the condition left by stripping them away with the 
 costal plem'ie with a view to conceal the appearances of disease, should at 
 once attract attention and lead to a close examination. 
 
 The various conditions are all forms of one and the same process, and 
 caused by a microbe which, growing in the tissues, gives rise to the tubercles, 
 and which, by reason of its being thrown otf from the diseased animal in 
 quantity, renders the malady a contagious one. The temperature which is 
 most favourable to the growth of the microbe is that of the ordinary body- 
 heat of a warm-blooded animal, say 98° to 100° Fahr. A temperature of or 
 below 32° Fahr. appears to kill it, as does also continued exposure above 108° 
 Fahr. These are points of considerable practical moment, as suggestive of 
 the probable effects of cooking or of refrigeration upon the bacillus. It is 
 regarded as established that the infectious discharges of a tubercular animal 
 remain actively virulent in this climate for a long time after they have been 
 cast from the body, and stalls and sheds may thus become a source of danger 
 unless thoroughly cleansed. Inhalation appears to be the usual way in which 
 the microbe enters the body, a circumstance which would be anticipated from 
 the frequency with which the lungs are the seat of the disease ; on introduction 
 into the blood, the disease may spread so rapidly as to constitute acute or 
 general tuberculosis, or, on the other hand, it may be limited for a consider- 
 able time to the point of entry and neighbouring lymphatic glands, which 
 local lesions are frequently the only ones detectable, producing during life no 
 symptom whatever, the animal being slaughtered in prime condition. 
 
 As the malady progresses, emaciation and weakness become marked, milk 
 diminishes and is poor in quality ; when the animal is slaughtered the 
 extensive signs of the disease already described are met with, the flesh is 
 soft, skinny, and dropsical, the fat wet and flabby, the carcase, in short, pre- 
 senting every sign of unsound meat. 
 
 A very important and much discussed question is : At what stage is the 
 flesh of a tubercular animal unfit for human consumption ? Some observers 
 contend that the whole carcase should be destroyed if the merest trace of 
 tubercle is discovered, even though the carcase may be otherwise in prime 
 condition. The general practice, however, in this country is to condemn any 
 carcase in which the disease is extensive, or has progressed so far as to cause 
 deterioration of the flesh. In Prussia, where very great care is taken in 
 inspecting meat, the law is to this effect : — ' The condition of the flesh of a 
 tubercular animal is to be regarded as dangerous to health when the meat 
 contains tubercular nodules, or the tubercular animal has begun to show 
 emaciation ; while, on the other hand, the meat is to be regarded as fit for 
 food when the masses of the tubercle only occur in an organ, and in general 
 the beast is well nourished.' The French decree says : ' The flesh of tuber- 
 culous animals shall be excluded from consumption (1) if the lesions are 
 generahsed, that is to say, not confined ; (2) if the lesions, although locahsed, 
 have invaded the greater part of an organ, or constitute an eruption on the 
 walls of the chest or the abdominal cavity.' 
 
 That the tubercle bacillus may be introduced into the body by swallow- 
 ing is shown by the fact that tubercular secretions, mucus, saliva, portions 
 of tubercles from diseased tissues, and cultures of the bacilli have been 
 swallowed by various animals, and some of these animals have subsequently 
 developed the disease. It will be noted that in all of those cases the presence 
 of the bacilli was demonstrable in the tissues swallowed — the most diseased 
 parts were, in fact, carefully selected for the experiments. There is obviously 
 a vast difference between eating masses of tuberculous matter, and eating 
 the properly cooked flesh of an animal which is sound except for the presence 
 
TEE INSPECTION OF MEAT 501 
 
 of, say, a nodule in the lung. In the report of the inquiry of the Depart- 
 mental Commission appointed by the Privy Council in 1888 to inquire into 
 the subject of tuberculosis, no case of tuberculosis in man from eating the 
 flesh of tubercular animals was stated, although witnesses were fully inter- 
 rogated upon this point. Professor Bang, of Copenhagen, thinks that experi- 
 ments show that the muscular tissue is so unfavourable a nidus for the 
 tubercle bacilli that they do not multiply in it. He is of opinion that the 
 seizure of the meat of every tuberculous animal is too severe a measure, and 
 where the lesion is localised he does not consider that the consumption of 
 the meat is attended with danger. 
 
 Foot mid Mouth Disease is common amongst cattle, sheep, and pigs. It 
 is characterised by rise of temperature as a premonitory symptom, the animal 
 showing by sucking its lips and the movements of its tongue that the mouth 
 is the seat of suffering ; saliva flows freely from the mouth. On examina- 
 tion, vesicles, or their bases ulcerated from maceration in saliva, are found 
 on the tongue and on the mucous membrane of the mouth. The animal does 
 not refuse food, but frequently drops it instead of swallowing it, feeding 
 being evidently attended with pain. In most instances the feet are also 
 affected, blisters forming around the hoofs ultimately drying into scabs ; 
 vesicles also frequently form upon the udders of milk cows, more especially 
 about the teats, which dry after a time into scabs. The disease is very 
 infectious, but as a rule so mild in its course as to interfere but slightly if 
 at all with the condition of the flesh of animals affected by it. Occasionally 
 in chronic cases, or when the infected animals have been exposed to wet 
 or neglect, the conditions may be aggravated, the eruption extending into 
 the alimentary canal, and the flesh becomes proportionately deteriorated, 
 sometimes to an extent which renders it unfit for food. Under ordinary 
 circumstances the flesh cannot be distinguished from that of perfectly 
 healthy animals, and there is no reason why it should not be passed 
 for food ; the affected parts, however, the head, feet, and udder, should be 
 destroyed. 
 
 Pleuro-pneumonia, that is, contagious pleuro-pneumonia of cattle, is a 
 disease of great importance. The commencement of an attack is very 
 insidious, and great difficulty may be experienced in determining the nature 
 of the illness at the outset. The temperature soon rises to 104° or 105° Fahr., 
 and the animal refuses food ; a short dry cough develops, and the breath- 
 ing becomes laboured and painful. Percussion on the side of the chest may 
 reveal dulness, and pressure may cause the animal to shrink. In milk cows 
 the secretion of milk is lessened or stopped. Post mortem the signs of 
 inflammation of the lungs and pleura are met with ; the pleural surfaces of the 
 lungs and thorax are thickened and roughened with deposited lymph ; the 
 lungs in the early stage exhibit commencing solidification, and later, marked 
 hepatisation, the organ being to a more or less extent solid, and necessarily 
 greatly increased in weight ; pleuritic effusion is common. The extent to 
 which the carcase is prejudiced in respect to its fitness for human food, will 
 depend upon the degree to which the disease has advanced before the animal 
 is slaughtered. In the early stages nothing can be detected in the carcase 
 to indicate that the animal had serious and acute illness ; the flesh is perfectly 
 normal in colour, smell, and consistence, and is firm and well-set ; but with 
 the advance of the disease, in addition to wasting, the flesh is dark and dis- 
 coloured, imperfectly bled and badly set, moist, and the connective tissue 
 sometimes infiltrated with serum. It is a general practice, from which there 
 is no reason to depart, to allow carcases of animals affected with pleuro- 
 pneumonia to pass into the market, provided they present no signs of disease, 
 
502 HYGIENE 
 
 nor departure from normal conditions ; but when the disease has advanced, 
 and the consequences already alluded to are present, the carcase should be 
 condemned. 
 
 The legislature provides stringent regulations for the suppression of 
 pleuro-pneumonia ; immediate notification to the local authority of the 
 existence of the disease is required, and all infected animals, as well as all 
 others which have been in contact with those infected, are slaughtered, and 
 compensation is paid to the owners in these cases. The infected places 
 must be subsequently cleansed and disinfected as prescribed, and the premises 
 are not to be declared free from infection for fifty-six days from the date of 
 the cessation therein of the disease. 
 
 Anthrax and Anthracic Diseases. — Anthrax occurs in cattle, sheep, horses, 
 and sometimes in pigs ; the disease is rapidly fatal, especially so in cattle, the 
 first sign of an outbreak of anthrax or splenic fever being often the discovery 
 of a dead animal, which but a few hours previously had been in apparent 
 health. The disease is readily inoculable into other animals, inoculative 
 contagion being a common means of its transmission. Anthrax is of im- 
 portance both on account of the devastation sometimes caused by it amongst 
 animals which furnish food for man, and not less on account of the serious 
 consequences which it produces in the human subject. The Bacilhis 
 avthracis, found mainly in the blood and spleen of infected animals, is 
 rod-shaped, multiplying by division, and when artificially cultivated, growing 
 into long homogeneous-looking filaments, straight or twisted, in which spores 
 ultimately make their appearance. These spores become free, and when 
 artificially cultivated, or injected into the blood of a rodent, germinate into the 
 characteristic bacilli. In the human subject anthrax occurs amongst those 
 engaged in handling raw hides, and also as ' woolsorters' disease ; ' the usual 
 mode of infection in these cases is by inhalation of spores adhering to the 
 wool of animals dead of anthrax, or by their inoculation into abrasions upon 
 those handling hides. In all cases, in animals as in man, the blood-vessels 
 of all organs contain the bacilli, and extravasations of blood are frequent in 
 many parts of the body ; the liver, kidneys, and spleen are congested, the 
 spleen being much enlarged, soft, dark in colour, and sometimes found to be 
 ruptured; this condition of the spleen gives rise to the names 'splenic fever' 
 and ' splenic apoplexy ; ' the lymphatic and mesenteric glands are also en- 
 larged and softened. In the earliest stage of disease, the fiesh may not present 
 marked change, but the local lesions rapidly develop, the odour of the tlesh 
 is of a peculiar unwholesome kind, and decomposition sets in rapidly. The 
 flesh should be destroyed. Immediate notice of the existence of this disease 
 must be given to the local authority, whose duty it is to ensure that measures, 
 including cleansing and disinfection, be taken to pi-event its spread, and who 
 must order the disposal of the mfected carcases by burial or destruction. 
 ' Black-quarter,' ' black-leg,' or ' quarter-ill ' is an anthracoid disease w^hich 
 is characterised by hiemorrhagic effusion into the subcutaneous or inter- 
 muscular tissues of one or both of the anterior or posterior extremities. The 
 disease is not uncommon amongst cattle, is very infectious, and usually ends 
 fatally the second or third day after infection. The extravasations, as also 
 the abdominal and thoracic viscera, contain characteristic bacilli. The flesh 
 of an infected animal should not be consumed even if slaughtered in the 
 earliest stage of illness ; if the disease has made any progress the carcase 
 must obviously be destroyed ; decomposition is rapid. 
 
 ' Braxy ' is a term applied to a variety of conditions, some of which are 
 allied to splenic apoplexy in the sheep, others result from various chronic 
 illnesses and the mal-nutrition caused thereby. ' Wet braxy ' appears to 
 
THE INSPECTION OF MEAT 503 
 
 include various dropsical conditions irrespective of the cause which gives 
 rise to them ; under the term ' red braxy ' appear to be included a variety of 
 inflammatory and parturient conditions varying greatly in importance and 
 resulting generally in discolouration of the flesh. Errors in dieting influence 
 the colour of the flesh, occasionally giving it a dark or bile-stained appear- 
 ance ; but this condition may usually be distinguished from more serious 
 inflammatory or septicsemic conditions by the degree, and by the condition 
 of the carcase after time has been allowed for setting, and also by the absence 
 or presence of local lesions, which must be carefully looked for. Under no 
 circumstances should the flesh of an animal infected with anthrax or septi- 
 caemia be allowed to pass into the market, and it is almost unnecessary to 
 say that the carcases of animals dead or killed when dying of parturient or 
 other inflammatory diseases should also be excluded ; the discoloured, stained, 
 unbled carcase, probably in an incipient stage of decomposition, stands self- 
 condemned, and needs no expert knowledge to condemn it. 
 
 ' Joint-ill' or *■ joint felon ' are names applied to acute rheumatism with 
 exudation into the joints, and also to a septic condition in very young 
 animals, arising from septic inflammation of the navel, which gives rise to 
 serous or purulent accumulations in the joints, and to the formation of 
 abscesses in the neighbourhood of the aftected joints ; the carcases of animals 
 so affected are totally unfit for human food. 
 
 Swine i^et'er, called also 'hog cholera,' 'typhoid fever of swine,' 'purples,' 
 ' soldier,' &c., is a very fatal disease amongst swine, and one which in the 
 later, if not in all stages renders the flesh of the affected animal unfit for 
 consumption. The disease is readily communicable, and once it obtains a 
 hold amongst a herd of swine the spread is rapid and the losses consequently 
 great. Hence the stringency of the Privy Council Orders in requiring a 
 notification of every outbreak of the disease to be made forthwith to the 
 appropriate authority, and empowering the local authority to treat the 
 place as an infected place, and to cause any affected swine to be slaughtered 
 and also any swine which may have been in the same sty or shed, or in 
 contact with the affected animals.^ 
 
 Unfortunately, in the early period of its development, the disease during 
 life is very difficult of detection, the animal perhaps feeding less readily, and 
 being less vigorous than usual, but in no other way showing any important 
 departure from the healthy state. In the varying modes of its development 
 and progress it shows an analogy with typhoid fever in man. Sooner or 
 later, however, more marked constitutional symptoms arise ; refusal of food ; 
 rise of temperature to about 105° Fahr. ; unsteady gait ; partial paralysis of 
 one or both hind quarters ; diarrhoea, the evacuations being frequently mixed 
 with blood ; red patches or blotches appear on the skin, and frequently 
 vesicles which dry up, forming a crust. In some instances extravasated 
 patches appear. It must be noted that swine are very prone to redness of 
 the skin, which therefore must not be looked upon as pathognomonic ; ex- 
 posure, over-driving, and certain articles of food, may all induce a superficial 
 redness more or less marked. 
 
 Posi-morte77iexamination shows inflammationand ulcerations of the alimen- 
 tary canal, most commonly in the large intestine ; the ulcers bear a resem- 
 blance to those of the human intestine in typhoid fever ; occasionally a 
 diphtheritic deposit covers considerable tracts of the mucous membrane of 
 the intestine. Patches of congestion or consolidation are nearly always 
 
 ' The local authorities are empowered to pay compensation for animals so slaughtered 
 to the extent of half the value (not exceeding forty shillings) of a diseased pig, and fuU 
 value (not to exceed 41!.) for a healthy pig. 
 
C04 HYGIENE 
 
 found in the lungs, and tlie liver, lymphatics, and other parts are frequently- 
 congested or present infiltrations of blood. With regard to the carcase, it 
 must be noted that the redness of the skin, when it exists in this disease, is 
 apparent after scalding and scrapmg ; the redness extends through the 
 subcutaneous fat down to the flesh. As the disease advances, the flesh 
 becomes emaciated to varying degrees, pale, flaccid, dropsical, and of a 
 peculiar and unwholesome odour. 
 
 Flesh from Animals which have Died, or wJiich have been Damaged or 
 Killed hij Accident. — The carcases of animals which have been drowned or 
 smothered, or which have been found dead from other causes, are dark and 
 discoloured by reason of not having been bled; the thoracic, and more 
 especially the abdominal walls, are stained from contact with viscera, the 
 odour is ofl'ensive, and discolouration from incipient decomposition, which 
 rapidly advances, adds to the unsightliness of the carcase. Most meat of this 
 class must always be condemned. Fractures, wounds, and bruising, the 
 frequent result fi'om animals being trampled on by others, owing to improper 
 penning in transit, may cause injuries so extensive as to necessitate imme- 
 diate slaughter ; in these cases, if the animal be properly bled and dressed, the 
 undamaged portions are normal in condition and may be passed, the damaged 
 parts only being condemned. Cceteris paribus, in these animals, as in those 
 which have been in ill-health from any cause, decomposition of the flesh 
 appears to set in earlier than in the flesh of animals slaughtered in prime 
 condition. It is also said that, during warm weather. Transatlantic cattle 
 slaughtered at depots in this country present signs of decomposition in the 
 neighbourhood of the thigh and shoulder soon after slaughter ; this is 
 attributed to the fatigue and constant movement during the long journey. 
 
 Parturient Animals. — Carcases of animals which, owing to abnormal con- 
 ditions, have been slaughtered immediately before, during, or after parturition, 
 are not necessarily to be condemned. If the labour have been prolonged, 
 the animal exhausted, and bruising and evidences of extravasation or inflam- 
 mation about the pelvic outlet, haunch, and thighs be present, the flesh else- 
 where being pale or livid, wet, and ill-set, the seizure should be made. If,, 
 however, the casualty be one such as hfemorrhage or mal-presentation, and 
 the animal be slaughtered and promptly bled and dressed, the flesh may 
 present no abnormal characteristic and be perfectly fit for consumption. 
 
 In Milk-fever the stage of the illness will influence the condition of the 
 flesh ; it should not be passed if the usual signs of deterioration are present. 
 
 Blown Veal and Lamb. — The practice — and a very disgusting one it is — 
 exists among some low-class butchers of blowing up, with the breath, the 
 connective tissue of veal and lamb, and thereby giving an appearance of 
 plumpness to poor meat : the fraud is completed by taking melted fat into 
 the mouth and blowing it over the freshly dressed carcase. The practice is 
 an ofi'ence against ordinary bye-laws, and may be recognised by the emphy- 
 sematous condition of the meat which has been subjected to it. 
 
 Consequences of the Ingestion of Unsound Meat. — It has already been 
 pointed out that specifically harmful consequences do not necessarily follow 
 from the ingestion of in-nutritious flesh. Meat from emaciated and worn-out 
 animals is condemned on the sufficient grounds that it is in-nutritious, and 
 in consequence has not the qualities which the consumer requires. But in 
 regard to the consumption of flesh which is decomposing, or which is taken 
 from animals which have suffered from inflammatory disease, or certain para- 
 sitic diseases, the consequences are very difi'erent, and few medical men have 
 not from time to time had abundance of evidence to show this ; moreover, 
 cooking cannot be relied on to prevent this mischief. Unsound meat is 
 
THE INSPECTION OF MEAT 50.'> 
 
 liable to give rise to symptoms of gastro-intestinal disturbance, diarrhcea, 
 vomiting, colic, followed by more serious symptoms of septic poisoning, 
 prostration, pyrexia, and failure of the heart's action ; many such cases, some 
 resulting fatally, have been recorded. Pies of beef or pork, sausages, and the 
 like have also given rise to these conditions. Dr. Ballard quotes a number 
 of cases in which mischievous or fatal results have followed the ingestion of 
 animal food ; out of fourteen such instances, pig-meat of one kind or another 
 occasioned the illness in no less than nine, veal in one, beef in one, the kind of 
 meat not specified in two, tinned salmon in one. An explanation is suggested 
 of this special liability of pig-meat to produce these specific maladies : of all 
 adult flesh meats ordinarily eaten, pork, under the process of cooking, fur- 
 nishes the largest proportion of gelatin ; young meats, such as veal, are also 
 largely productive of gelatin, and gelatin is a favourite nutriment of morbific 
 bacilli. As a result of his investigations Dr. Ballard considers that ' in in- 
 fected food capable of producing disease on being eaten, we find one or both 
 of two things — a living microscopic organism and an organic chemical poison 
 of greater or less virulence. Of these two things, that which is immediately 
 operative in the production of the morbid phenomena is the chemical 
 poison which is apparently of a basic nature and a product of the processes of 
 bacterial life.' 
 
 ' Specifically different bacteria, capable of producing this chemical poison, 
 may through its agency give rise in the human system and in animals to 
 clinical phenomena and pathological changes in the organs which are so 
 similar that at present they cannot be distinguished.' 
 
 ' Given the bacterium and favourable environment, the bacterium may 
 grow, multiply, and produce its own special chemical poison from the material 
 which affords it nourishment either outside the body or within it.' 
 
 The presence or absence of an incubation period prior to the manifes- 
 tation of toxic symptoms is explained by Dr. Ballard as evidence of the 
 symptoms being due either to the operation within the body of the bacterium 
 itself, or of their being due to the operation of the chemical poison already 
 prepared in the food. Where merely the bacterium is introduced, time 
 is required for its growth and for the formation of its poisonous chemical 
 product ; when the chemical poison already prepared outside the body is 
 introduced, its operation is more speedy. 
 
 Not only is thorough cooking of importance in all cases, but equally so is 
 the observance of absolute cleanliness in every stage of the preparation of the 
 food for the table. 
 
 It must not be forgotten that thorough practical training is requisite 
 before the inspection of meat can be satisfactorily undertaken. A medical 
 man, or a veterinary surgeon, will necessarily have as a basis an acquaintance 
 with pathological processes, and any practical butcher must necessarily have 
 acquired experience of a useful kind. The routine work of meat inspection 
 is in many towns relegated to an ordinary sanitary inspector, who is instructed 
 to refer in matters of doubt to the medical officer of health. In many 
 instances this inspector has had no special training whatever, and conse- 
 quently the value of his services is small. The custom in vogue in Liverpool 
 for many years past is to select the meat inspectors with great care ; they 
 are men physically fit, of unquestionable character, and with practical ex- 
 perience as butchers acquired in the public abattoirs, and are reqmred to give 
 proof of a thorough acquaintance with meat of all classes before undertaking 
 the duties of inspector. Men of this class must, of course, receive an ade- 
 quate wage ; the work discharged by them is of great importance, and the 
 employment of untrained and incompetent men can only result in harm. 
 
CLOTHING 
 
 BY 
 
 CtEOEGE VIVIAN POOEE, M.D., F.E.C.P. 
 
 PHYSICIAN TO UNIVERSITY COLLEGE HOSPITAL 
 
CLOTHING 
 
 Olothing is used for the protection and adornment of the body ; and 
 although the latter object may be looked upon as subsidiary and unimportant, 
 it cannot be neglected while human nature is what it is. 
 
 Clothing protects the body against cold and heat, wind and rain, and to 
 a certain extent against knocks and bruises which are common enough in 
 the daily life of most of us, but especially of the working classes. Civilised 
 man, who is obliged to wear artificial clothing from his cradle upwards, is in 
 this respect at a disadvantage when compared with the lower animals, whose 
 natural clothing of fur, or wool, or hair, or feathers, is provided for them. 
 
 The power which man has, however, of changing his clothing and adapt- 
 ing it to differences of season and climate enables him to dwell in any part 
 of the world, and his conmiand of clothing thus gives him, so to say, an 
 extraordinary power of acclimatisation. 
 
 While the uses of clothing are undoubted, it has certain inseparable 
 drawbacks, the chief of which is the weight which it obliges us to carry ; 
 and this fact, as well as the form of our garments, must to a certain extent 
 hamper the free movement of the body, and in some degree interfere with 
 its development. It is during infancy and early life that attention to the 
 hygiene of clothing is of most importance. Clothing, again, harbours dirt, 
 and dirt is a great cause of disease, so that unless we pay constant attention 
 to the cleansing of our clothes, skin diseases, parasitic and otherwise, are 
 sure to result. 
 
 A treatise on clothing must necessarily be adapted to the climate and 
 habits of the people for whom it is written, and in what follows the needs of 
 English people, inhabiting a temperate though most variable and fickle 
 climate, will be mainly held in view. 
 
 In dealing with the subject of clothing, we shall first of all pass in review 
 the various materials which are chiefly used for the manufacture of clothes. 
 
 We shall next deal with the principles which should guide us in the 
 selection of clothing, and finally we shall discuss the details of clothing, and 
 endeavour to show how the principles previously discussed may be best 
 apphed to the clothing of the different regions of the body. 
 
 The materials used for clothing are mainly derived from the animal and 
 vegetable kingdoms, minerals being employed only to a very limited extent 
 for the production of the various accessories of clothing. 
 
 The materials derived from the vegetable kingdom are cotton, linen, flax, 
 hemp, straw, jute, coir, rhea, and some other fibres of less common use, and 
 also gutta-percha and india-rubber. 
 
 From the animal kingdom we derive furs, skins, leather, feathers, silk, 
 and wool. 
 
 The inorganic bodies employed in the manufacture of clothing are iron, 
 steel, and brass ; glass for buttons, &c. ; the precious metals, especially for 
 the decoration of military uniforms ; and, to a very limited extent, asbestos. 
 
 Wool is a modification of hair, and is furnished by the sheep, alpaca, 
 
510 HYGIENE 
 
 Angora goat (mohair), the Cashmere goat, camel, and other animals. Fibres 
 of wool (see Plate VI. d) have upon their sm-face imbricated scales which 
 all run in one direction, so that a fibre is easily pulled through the fingers 
 from root to point, but not so easily in the opposite direction. ^ These 
 imbrications cause woollen fibres to adhere tightly, and make it diflicult to 
 miravel closely woven woollen textiles. ' Under the influence of moisture 
 and pressure, tangled masses of wool thoroughly interlock and mat together 
 by the mutual clutching of the serrations of the fibres, and it is thus that 
 the shrinking and thickening of woollen textures under washing is accounted 
 for, and the capacity of the cloth for felting or fidling is due to this condition 
 of the fibre ' (Paton). The serrations are most numerous, acute, pointed, 
 and distinct in fine merino wools, as many as 2,800 per inch being counted 
 in specimens of the finest Saxony wools. In the Leicester wool of England 
 the serrations are less pronounced, and number only about 1,800 to the inch, 
 so that the fibre is smoother and less waved. In some inferior wools the 
 serrations are not so many as 500 to the inch. A similar difference exists 
 in the fineness of the fibre, which varies from -j;^^ inch in Saxony wool to 
 ■2 j-5- in coarse Algerian wools. 
 
 By various manufacturing processes wool assumes very different aspects : 
 cloth, flannel, blanket, worsted fabrics, linitted fabrics, are familiar examples. 
 Felt is made without spinning or weaving, simply by the cohesion of the 
 imbricated fibres. 
 
 ' Shoddy ' is made from woollen rags, which are first torn asunder by a 
 machine called a ' devil,' and then re-spun and re-woven, with a certain ad- 
 mixture of fresh wool. Shoddy has not the wearing properties of new wool, 
 but is useful for Hnings, rugs, wraps, druggets, blankets, &c. 
 
 Wool, according to Parkes, is soluble in a strong solution of liquor potassae 
 or liquor sod£e, while vegetable fibres are not attacked. It is little altered by 
 lying in sulphuric acid, it is thiged yellow by nitric and picric acids, and is 
 scarcely acted upon by an ammoniacal solution of cupric hydrate (cupram- 
 monia) or by a hot concentrated solution of zinc chloride, which dissolves silk. 
 Wool is more porous and more hygroscopic than vegetable fabrics, and 
 is a shghtly less perfect conductor of heat. While it absorbs moisture 
 readily, it gives it off slowly, so that far less cold is produced by the evaporation 
 from a woollen garment than from one made of vegetable fibre. It conserves 
 the heat of the body, and protects it from the heat of the sun, the latter 
 property being at its height if the garment be white. 
 
 Silk (see Plate VI. c), is a fibre produced by the Bomhyx Mori or mulberry 
 silk moth. According to Chinese tradition, the introduction of the silk in- 
 dustry was due to an empress who lived more than 2,000 years B.C. It was 
 not until the alter days of the Eoman empire that silk fabrics were employed 
 in Europe, and for a long period it remained the rarest and costliest of the 
 textiles. The silk glands, one on each side of the body, of the silkworm 
 open on the under hp of the larva by a common orifice. The secretion of 
 the gland is a sticky fluid which hardens on exposure to the air. 
 
 Each cocoon furnishes on an average about 500 yards of reliable silk. 
 According to Mr. James Paton, silk fibre consists of a centre or core of 
 fibroin, with a covering of sericin or silk albumen, and a little waxy and 
 colouring matter. Fibroin is analogous to horn and hair, and its composition 
 is represented by the formula CisH.^gN.rjOg. It is insoluble in water, alcohol, 
 and ether, but dissolves freely in concentrated alkaline solutions, mineral 
 acids, strong acetic acid, and ammonical solution of cupric hydrate. Sericin, 
 the gummy covering of the fibre, dissolves readily in hot soapy solutions and 
 in hot water. Silk is very hygroscopic, taking up as much as 30 per cent. 
 
CLOTHING 611 
 
 of water without feeling damp. It is a perfect non-conductor of electricity. 
 ' Silk is readily distinguished from wool and other animal fibres by the 
 action of an alkaline solution of oxide of lead, which darkens wool owing 
 to the presence of sulphur, but docs not affect silk. Silk dissolves freely in 
 common nitric acid, which wool does not. From vegetable fibres silk is 
 readily distinguished by the bright yellow colour given by picric acid. Micro- 
 scopically also the fibres are distinguishable. Manufactured silk is of two 
 kinds, reeled silk and spun silk, the latter being made from the waste and 
 spoiled cocoons by a process of carding and spinning. The gloss of the best 
 silk is produced by a process of scouring by means of which the external 
 albuminous coating is removed and the raw silk loses some 25 per cent, of 
 its weight. Mr. Paton (art. Silk, ' Encyclopaedia Brit.' 9th ed.) states that 
 in order to obviate this loss it has been the practice to dye dark-coloured 
 silks without scouring them, such silks being known as ' souples.' Silk 
 absorbs certain metallic salts with readiness, and more readily before than 
 after scouring. ' Up to 1857 the utmost the dyer could add was " weight for 
 weight," but an accidental discovery in that year put dyers into the way of 
 using tin salts in " weighting," with the result that they can now add 40 oz. 
 per pound to scoured silks, 120 oz. to " souples," and as much as 150 oz. to spun 
 silks, and yet call these compounds " silk." Not only so, but the use of tin 
 salts, especially stannic chloride (SnCl4), enables dyers to weight all colours 
 the same as black.' In his ' Eeport on English Silk Industry ' to the Eoyal 
 Commission on Technical Instruction (1885), Mr. Thomas Wardle, of Leek, 
 says : — ' Theproto- and per-salts of iron as weU as the proto- and per-salts of 
 tin, including also a large variety of tannin, sumac, divi-divi, chestnut, valonia, 
 the acacias from which are obtained cutch and gambier, &c., are no longer 
 used solely as mordants or tinctorial matters, but mainly to serve the object 
 of converting the silk into a greatly expanded fibre, consisting of a con- 
 glomeration of more or less of these substances. Sugar is also largely em- 
 ployed to weight silk.' 
 
 When, therefore, we speak of ' silk ' as an article employed in the manu- 
 facture of clothing, the word is used in a conventional sense only, since from 
 the foregoing it appears that a silk garment may contain as little as 10 per 
 cent, of true silk. 
 
 Fiir. — The warmest variety of clothing is undoubtedly fur, which has 
 been used from time immemorial by northern nations. Fur is furnished by 
 certain animals inhabiting cold countries, which have in addition to their 
 long ' overhair ' a dense hairy covering which is called fur. A skin with the 
 fur attached forms the best conceivable protection against cold and wind. 
 Furs are not only prized as affording a maximum of protection to the body, 
 but they are also in great demand for personal adornment. Ermine, chin- 
 chilla, bear, seal, and marten (Eussian sable) are amongst the most valued 
 for the latter purpose, and fetch very high prices, although for the true 
 purposes of clothing they are in no way superior to many of the commoner and 
 cheaper varieties of fur. (For microscopic appearance of Rabbit fur see Plate 
 VI. H.) 
 
 Fur is also used for making felt, the hair being removed from the skin and 
 by a process of compression, combined with heat and moisture, welded into a 
 compact and cohesive felt owing to the entanglement of the hair by means of 
 the microscopic imbrications on its exterior. The felts used for clothing 
 (mainly head-coverings) are made largely from hare skins and rabbit skins. 
 Coarser felts used for carpets, &c., are mostly made from cow hair. Felt is 
 a fabric of great antiquity, and it is considered probable that a knowledge 
 of felting wool preceded a knowledge of spinning and weaving. 
 
512 HYGIENE 
 
 Leather is the form in wliich tlie skins of animals are generally used for 
 the purposes of clothing. By tanning and alHed processes skins are made 
 tough, to some extent impermeable, supple, and not liable to putrefy. The 
 skins of many animals are used, but those of oxen are most important, the 
 skins of horses, goats, sheep, and other animals taking a secondary place. 
 Skins are prepared by tanning, tawing, or shamoying. 
 
 Tanning consists in steeping the skin in infusions of oak bark or other 
 bodies containing tannic acid. By this process the gelatin of the hide forms 
 an insoluble compound with the tannic acid, and this insoluble compound is 
 the basis of leather. Oak bark imparts firmness and sohdity to leather, and 
 the high quality of English sole leather is said to be due to the superiority 
 of the EngUsh oak for tanning purposes. Mimosa bark, hemlock bark (the 
 bark of the Abies canadensis), catechu, and other bodies are also largely used 
 for tanning. 
 
 To make the best quality of sole leather nearly a year is necessary, and 
 although many modern inventions have been used for shortening the process 
 the results in no case have been entirely satisfactory, and there now seems 
 to be no doubt that a slowly operating process produces the best leather. 
 
 Lighter leathers, which are used for the uppers of boots, are finished by 
 the currier, who removes inequaUties from the hides, impregnates them with 
 grease, 'grains' the surface, and finally coats them with oil, lamp-black, and 
 tallow. 
 
 The process of taiving is that of impregnating skins with mineral 
 astringents, such as alum, and it is apphed to many light leathers, such as 
 to kid uppers of boots. Eecently this process has been applied to heavier 
 leathers, bichromate of potash being the chemical employed. It is said 
 that by this process light skins can be prepared in less than a week, ox and 
 buffalo hides in a fortnight, and the thickest hides, such as walrus, in a month. 
 The process is both quick and cheap, but an experienced bootmaker has in- 
 formed the writer that skins prepared in this way are not fitted for high-class 
 goods, as the leather is apt to become stiff and harsh; and this same 
 practical authority is of opinion that nothing can replace time in the pre- 
 paration of good leather. 
 
 Shamoying is employed for light skins only, and consists in impregnating 
 the skin with fish oil, which undergoes a process of oxidation within the 
 pores of the skin, the result being the well-known shamoy (chamois) leather, 
 which is not unfrequently used for under-garments. 
 
 The chemical basis of vegetable fibre used for textile purposes is cellulose, 
 to which chemists have assigned the empirical formula of CeHjoOg, and the 
 percentage composition of which is (according to F. Schulze) 
 
 C 44-0 
 
 H 6-4 
 
 49-6 
 
 Nearly all cellulose contains a certain proportion of mineral constituents 
 (from 0*1 to 0"2 per cent.), so that when vegetable textiles are burnt, the 
 ash retains the original form of the fabric. There is also from 7 to 9 per 
 cent, of hygroscopic moisture, the mean variation of which, according to the 
 state of the atmosphere, amounts to about 1 per cent. 
 
 Cellulose is httle acted upon by most solvents. The best solvent for 
 cellulose is cuprammonia. According to j\Ir. C. F. Cross, the writer on 
 ' Cellulose ' in Watts's ' Dictionary of Chemistry,' the best method of effect- 
 ing this solution is to place the material with some copper turnings in a tube 
 which is narrowed below and pro^^ded with a stopcock. Strong ammonia 
 
CLOTHING 513 
 
 is poured upon the contents of the tuhe, and after standing for some minutes 
 is drawn off and returned to the tube ; the operation is several times re- 
 peated, until the solution of the substance is effected. ' The property of 
 cellulose of being dissolved by cuprammonia receives an important technical 
 apphcation. A sheet of paper left for a short time in contact with the 
 cuprammonia, so that the constituent fibres are superficially attacked, and 
 then passed between rollers and dried, becomes impervious to water, and its 
 cohesion is not affected at the boiling heat.' 
 
 The reagent which is chiefly used for the detection of cellulose, a reagent 
 which is applicable to microscopic work, is a mixture of zinc chloride, and 
 iodine thus prepared. Zinc is dissolved to saturation in hydrochloric acid, 
 and the solution evaporated to the sp. gr. 2*0 ; to ninety parts of this solution 
 are added six parts of potassium iodide in ten parts of water, and in this solu- 
 tion iodine is dissolved to saturation. By this reagent cellulose is coloured 
 uistantly a deep blue or violet. 
 
 Cotton, which is by far the most important of all vegetable fibres used 
 for textile purposes, is the downy hair attached to the seeds of plants belong- 
 ing to the genus Gossypium of the natural order MalvaceaB. Cotton garments 
 were in use among the inhabitants of China and India at a date prior to the 
 Christian era, and the Mexicans and Peruvians were found to possess cotton 
 textiles in the sixteenth century. 
 
 It was not till 1770 that the planters of the Southern States of America 
 turned their attention to cotton, and it is said that the first bales of American 
 cotton came to Liverpool shortly before that date, and remained many 
 months unsold. 
 
 The fruit of the cotton tree consists of a capsule containing from three 
 to five valves, and as many divisions, holding a number of seeds. These 
 seeds are each surrounded by a flock of cotton, which becomes swollen when 
 the seed reaches maturity and the valves consequently open. The cotton 
 and the seeds are pulled off, and after drying in the sun are separated from 
 each other by the process of ' ginning.' 
 
 The quality of the cotton is judged by the length of its fibres, which vary 
 from half an inch to an inch in length. Cotton filaments when fully ripe, but 
 not dried, exhibit under the microscope a membranous, hollow, cylindrical 
 tube, closed at both ends. When dried it becomes flattened and twisted, and 
 assumes a ribbon-like shape, rather thicker at the edges than in the middle. 
 (See Plate VI. b.) 
 
 Cotton consists mainly of cellulose, but there is also in cotton yarn, 
 according to Dr. Schunk, about "3 per cent, of organic matter, consisting of 
 (1) cotton wax, (2) margaric acid, (3) a colouring matter easily soluble in 
 alcohol, (4) a colouring matter soluble with difficulty in alcohol, (5) pectic 
 acid, (6) albuminous matter. 
 
 In the course of manufacture cotton goods are subjected to a great 
 variety of processes. After the weaving comes the bleaching, and then the 
 * finishing ' of goods for the market. Among the finishing processes are 
 mangling, starching, damping, ' beetling ' — which is, in fact, hammering by 
 machinery — and calendering, which consists of pohshing by means of a 
 machine which has been evolved from the mangle. 
 
 On the subject of ' starching ' Mr. J. Paton, whose valuable articles in the 
 ' Encyclopaedia Britannica ' we have frequent occasion to quote, says : — ' It is 
 in this stage that so much is done by some bleachers to give cloth a factitious 
 appearance of weight and bulk by filling up the interstices between the 
 fibres with compounds which have no other object than to please or deceive 
 the eye, and some of which have a decidedly deleterious influence on the 
 
 VOL. I. L Ii 
 
514 HYGIENE 
 
 tissues they are intended to improve in appearance. A gi-eat variety of 
 mixtures, both cheap and nasty, are used by some finishers in place of 
 starch with a view to produce weight and appearance ; but, naturally, as 
 little information as possible on this point is permitted to leak out to the 
 public' 
 
 Pure starch is alone used by reputable bleachers, but why even this is 
 necessary it is not quite clear to one who is only a purchaser and not a 
 manufacturer of calicoes. The same writer, in his article on calico printing, 
 has some instructive remarks concerning the use of aniline colours, which he 
 says ' now constitute the largest and most important section of steam-fixed 
 dyeing materials.' ... ' The process of fixing these colours now generally 
 adopted is known as the arsenite of alumina process. In this process the 
 dye is dissolved in water or acetic acid, carefully filtered through a fine cloth 
 and mixed with acetate of alumina, a thickener, and arsenious acid dissolved 
 in glycerine. This mixture is printed on the cloth, which is then introduced 
 into the steaming chest. In the steaming, acetic acid is liberated and arsenite 
 of alumina formed, which with the aniline colour is precipitated in the fibres 
 as a brilliant insoluble lake.' 
 
 From this it appears that aniline colours in respect of their toxic poten- 
 tialities may be in no respect superior to those in which compounds of arsenic 
 have avowedly been used. 
 
 Flax has been from the earliest periods of the world's history one of the 
 most important of the textile fibres. There is evidence that it was in use 
 by the Swiss lake dwellers, and, coming down to historic times, there is no 
 doubt that it was extensively employed for clothing by the Egyptians. This 
 fibre is obtained from the stalks of Linum usitatisswnLm and other varieties 
 of the flax plant. The plants when approaching ripeness are pulled up by 
 the roots and the seed capsules or ' bolls ' are separated, the processes being 
 technically known as ' pulling and rippling.' The rippled stalks are then 
 tied in bundles and, being steeped in water, are exposed on the grass to the 
 dew, and undergo a process of putrefactive fermentation technically known as 
 ' retting,' or ' rotting,' whereby the gummy and other matters are separated 
 from the fibres. Finally the fibre is prepared for the market by being beaten 
 and combed in the process known as ' scutching.' The plants yield about 
 6 per cent, of marketable fibre. 
 
 Hugo Miiller gives the composition of best Belgian flax as follows : — 
 
 Ash 0-70 
 
 Water 8-65 
 
 Extractive ......... 3'65 
 
 Fat and wax ......... 2-39 
 
 Cellulose 82-57 
 
 Intercellular substance and pectose bodies . . . 2-74 
 
 Total . 100-70 
 Microscopically the flax fibre is seen to be marked at regular intervals by 
 transverse striae, which indicate the divisions of the cells of which the fibre 
 is composed. According to Wiesner, the width of the fibre varies from -012 
 to '025 millimetre, and the length of the individual cells varies from two to 
 four milhmetres, while the fibre as a whole ranges in length from 20 to 
 140 centimetres. (See Plate VI. a.) 
 
 Mr. James Paton, in his article on linen in the ' Encyclopaedia Britannica,' 
 says that linen is much smoother and more lustrous than cotton cloth ; and, 
 presenting a less ' woolly ' surface, it does not soil so readily, nor absorb, nor 
 retain moisture so freely, as the more spongy cotton ; and it is at once a cool, 
 clean, and healthful material for bed-sheeting and clothing. Bleached linen, 
 
[ Tr e sLti s e on Hy § xe n e .] 
 Vol.1. 
 
 PI. VI 
 
 
 i 
 
 
 
 
 
 
 S 
 
 ^j^js 
 
 fc^ 
 
 r:^, 
 
 ■^ 
 
 IP. B.Weils del. 
 
 IVfest^Newiaaji iiop. 
 
CLOTHING 515 
 
 starched and dressed, possesses that unequalled purity, gloss, and smoothness 
 which make it alone the material suitable for shirt fronts, collars, and wrist- 
 bands ; and the gossamer delicacy, yet strength, of the thread it may be spun 
 into fits it for the fine lace-making to which it is devoted. Flax is a heavier 
 material than cotton, but weight for weight it is much stronger, single yarn 
 having proportionate strength in the ratio of 3 to 1"83, double yarn 3 to 2-20, 
 and cloth 3 to 2-13. 
 
 Bhea is a fibre obtained from one or more species of Bohmeria, plants 
 resembling nettles, and of the same natural order (Urticacete), growing in 
 India, China, and elsewhere in tropical and sub- tropical districts. As far as 
 the writer is aware, it has not been used for clothing, but it is likely that 
 modern and improved methods of preparation may render it available for 
 that purpose, and therefore it is included in this article. 
 
 Jwfe is a fibre obtained from Corc/iorws capsularis and Corchorus olitorius 
 plants, of the natural order Tiliacese, which are grown for manufacturing 
 purposes, mainly in Bengal. Jute fibre is brittle and very hygroscopic (see 
 Plate YI. g). It is used mainly for coarse textiles, such as sacking, mats, &c. 
 In India it is used to a limited extent for the manufacture of clothing, and in 
 ■this country it is said to be employed for the adulteration of other textiles, 
 such as silk, and also in the manufacture of false hair. 
 
 Hemp, the fibre obtained from Cannabis sativa, is mentioned by Herodotus 
 .as being used by the Scythians for the manufacture of their garments (see 
 Plate VI. b). 
 
 Coir is a coarse fibre obtained from the outer husk of the cocoa-nut. It is 
 ;much used for mats, ropes, and coarse work, but its use for clothing is ex- 
 tremely limited (see Plate VI. f). 
 
 India-rubber, or caoutchouc, is an article of clothing of great and growing 
 importance, although of comparatively modern introduction. It is elastic 
 .and absolutely impermeable to water. The former property is of service in 
 various accessories of clothing, such as the ' side-springs ' of boots, while the 
 latter is made use of in the manufacture of the great bulk of waterproof 
 ■clothing. The first use of india-rubber for waterproofing clothes seems to 
 have been made by the Spaniards in Mexico in the beginning of the sixteenth 
 century, but its extensive use dates only from the beginning of the present 
 century. Caoutchouc is obtained from the milky juice of several plants 
 growing in Asia, Africa, and South America. Among the plants which yield 
 caoutchouc are the Hevea braziliensis and the Manihot Glaziovii, two 
 Euphorbiaceous trees growing in South America, and the Ficus elastica, an 
 East Indian plant growing in Assam and elsewhere in the Himalayan dis- 
 trict. The plants named, however, are only three out of several which yield 
 this valuable product. Caoutchouc has its elasticity impaired and destroyed 
 fey a freezing temperature, and it undergoes a contraction at temperatures 
 a little above blood heat, while at still higher temperatures it softens and 
 melts. Caoutchouc is a complex body ; it is porous and absorbs water (i.e. 
 in its raw state) when submitted to prolonged soaking. Among its pecuhar 
 properties is the one that freshly cut surfaces unite firmly — a fact of which 
 the chemist and the manufacturer make abundant use. Among the solvents 
 of caoutchouc are benzene, carbon disulphide, petroleum, ether, and chloroform. 
 Most fatty substances destroy caoutchouc, making it first soft and then hard 
 and brittle, and to this fact is due the frequent damage done to water-pillows, 
 &c., in hospitals. ' Vulcanisation ' is effected by steeping the caoutchouc in 
 melted sulphur, maintained at a temperature of 140° C, and by other methods. 
 Macintosh cloth is made by spreading on layer after layer of caoutchouc paste 
 in solution on a cotton or silk textile, but into the details of manufacture it 
 
 n,2 
 
51G HYGIENE 
 
 is not our province to enter. For most of the above facts the ^^Titer is in- 
 debted to an article by Messrs. Holmes and Bolas in the ' Encyclopaedia 
 Britannica ' (9th edition). 
 
 Gutta-percha is of secondai-y importance as an article of clothing, as its 
 use in this direction is almost limited to the occasional manufacture of boot 
 soles. This material, like india-rubber, is furnished by the lacticiferous vessels 
 of certain trees, and the distribution of these trees is almost limited to the 
 Malay Peninsula, and to about six degrees north and south of the Equator. 
 Seeing that the trees in order to produce gutta-percha have to be felled, and 
 that the artificial cultivation of the tree is not practised, there is some reason 
 to fear that this article may become scarce. 
 
 Inorganic bodies are of very limited use for clothing, now that plate and 
 chain armour are no longer worn. The metals are, however, much used for 
 the indispensable accessories such as hooks-and-eyes, buttons, nails and tacks. 
 Metal springs are perhaps too much used in the manufacture of women's corsets. 
 
 Asbestos is occasionally used for making fire-proof gloves, and it is said 
 that quite fine textiles may be made of it, and that the ancients used to wrap 
 their dead in asbestos cloth. It cannot fairly be regarded as an article used 
 for clothing. The same may be said of ' spun glass,' which may still be seen 
 occasionally decorating the head of a State coachman. Mineral and other 
 matters are abundantly used as adulterants for fabrics, in order to give weight 
 and a fictitious amount of substance, and there is reason to think that this is 
 much practised in the production of corduroy, moleskin, and similar heavy 
 materials worn by the labouring classes. In the Parkes Museum is a piece 
 of Manchester ' goods,' which after drying at 212° F. weighed 608 grains. 
 After washing and again drying this fabric weighed 387 grains, showing that 
 221 grains, or more than 36 per cent, of soluble and other material remov- 
 able by washing, was contained in it. 
 
 The remarks which we have incidentally made while discussing the 
 fabrics seriatim will have shown that the pm-chaser is very liable to be 
 deceived as to quality. At the Army Clothing Factory in Pimlico, every 
 precaution is taken to prevent fraud on the part of manufacturers. 
 
 When fabrics arrive in the bale or piece they are first of all weighed and 
 measured by a machine which performs both operations simultaneously and 
 with great rapidity. In this way assurance is obtained that length and 
 weight bear a proper proportion to each other, and that the fabric, whatever 
 it may be, is of the desired stoutness. 
 
 The next process is called ' perching.' The fabric is unfolded, and pass- 
 ing over a roller near the ceiling descends towards the floor. This is done in 
 front of a large window, so that the ' right side ' of the fabric has a strong 
 light upon it. Two scrutineers stand in front of the descendmg fabric, 
 between it and the window, while a third stands behind the fabric and 
 watches it by the transmitted light of the window. In this way flaws and 
 blemishes are at once detected, and for every such flaw or blemish deductions 
 are made from the contract price. Next the tearing strain is tested by a 
 machine, which records the number of pounds of tension which causes the 
 fabric to tear, the tearing strain being fixed by contract. The next step is to 
 ascertain that no fibre has been used in the manufacture other than the one 
 contracted for, and this is done by a systematic chemical analysis and micro- 
 scopic examination. Finally, the dyes used are chemically examined. In this 
 way all forms of deception are guarded against. 
 
 A thoroughly experienced eye is a tolerably safe guide for testing fabrics. 
 Such an eye will usually detect any mixture of fibres, and will be able to judge 
 of the quality and fineness of the weaving. It is said that good materials 
 
CLOTHING 517 
 
 'have always a firm, strong selvage, and careful housewives generally look to 
 this point. A good test is to rub the fabric briskly between the hands and 
 against the light. A heavily sized and starched fabric will emit a cloud of 
 dust under this test, and this cloud shows that it is very nearly worthless. 
 Such fabrics appear far more translucent after such rubbing than they did 
 before, and it will generally be found that these sized articles tear very readily, 
 and after their first washing their real flimsiness is abundantly apparent. 
 
 If large quantities of a material are going to be used, it would always be 
 wise to obtain a sample and thoroughly examine and wash it before pur- 
 chasing. In this way its genuineness and the ' fastness ' of the colours may 
 be very fairly judged of. If a few fibres be teazed out and examined by the 
 microscope, one may obtain almost absolute knowledge as to the composition 
 of the fabric. 
 
 A great deal has been written of late years as to the best material for 
 ■ clothing, and there are not wanting those who urge that the 'natural 
 clothing ' of animals is the ' natural ' and only proper clothing for the first 
 of all animals — man. An assertion of this kind seems to us to be in some 
 degree similar to the old dogma that ' animal heat ' was different from other 
 kinds of heat ; a plausible theory which the hatching of eggs in incubators by 
 means of artificial heat has done much to explode. 
 
 There can be no doubt that wool and furred skins are of great and un- 
 doubted value as articles of clothing, and that they will be eagerly sought 
 in the future as they have been in the past. To assert, however, that these 
 are the only proper articles from which to manufacture clothing must tend 
 to deprive the public unnecessarily of the numerous vegetable fibres, which 
 if properly manufactured are scarcely inferior for many purposes to garments 
 made of wool. 
 
 The great value set upon wool as an article of clothing is attributable to 
 the alleged fact that it has far less conducting power for heat than either 
 cotton or linen. Thus Parkes (' Practical Hygiene,' 5th edition) quotes the 
 experiments of Coulier and Hammond on the conducting power of different 
 materials. 'In both cases a polished metallic vessel was filled with hot 
 water of a known temperature, a delicate thermometer inserted, and the 
 vessel was hung in an empty room ; the time required for cooling to a given 
 point when the vessel was uncovered and covered by different fabrics was 
 noted by the observer at a distance with a magnifying glass.' Coulier's 
 experiments gave the following results : — 
 
 Time required for Cooling from 122° F. to 104° F. 
 
 Vessel uncovered 18' 12" 
 
 Vessel covered with cotton shirting 11' 30" 
 
 „ linings 11' 15" 
 
 hemp „ 11' 25" 
 
 „ blue woollen cloth for uniforms . . 14' 45" 
 
 red „ „ . . . 14' 50" 
 
 ,, blue ,, great-coats . . 15' 5" 
 
 It scarcely needs an experiment to show that a material used for a great- 
 coat is a worse conductor of heat than a piece of thin shirting or lining, and 
 that is all that the above experiment seems to us to show. 
 
 To test the thermal conductivity of different substances is a most difficult 
 matter, and the experiments need to be conducted with a degree of precision 
 and delicacy which can scarcely be overestimated. Whether a great-coat or 
 a shirt conducts the better is not the question, and can never be a serious 
 .question. What we have to determine is the difference, if any, between the 
 
518 HYGIENE 
 
 thermal conductivities of equal fibres of ^vool, cotton, liemp, or linen under' 
 exactly equal conditions. The table of ' Thermal Conductivities ' given by 
 Su" ^^'illiam Thomson in his article ' Heat ' in the ' Encyclopiedia Britannica ' 
 (9th edition) seems to show that the difference between different fibres 
 used for clothing is scarcely appreciable. 
 
 Copper, according to this table, is the best conductor, its conductivity 
 being represented by the number 'Ol. Iron is nearly six times less than 
 copper, its conductivity being represented by the number '16. 
 
 The numbers given for the clothing materials are so small that they may 
 be regarded as practically non-conductors. They are : — 
 
 Wool (carded) of all densities -000122 
 
 Calico (new) of all densities "OOOISO 
 
 Hempen cloth (new) ........ -000144 
 
 Air -000049 
 
 Water -002 
 
 Cork -000029 
 
 Eider-down -000108 
 
 Air is one of the worst conductors of heat, and it is highly probable that 
 the power of different clothing materials in keeping the body warm depends- 
 more upon the amount of air entangled, so to say, in the fabric than upon 
 the material used in the construction of the fabric. That different materials 
 are habitually woven in different ways is well known, and the fact that one 
 material is ' warmer ' than another is often due to the fact that it lends itsell 
 by its nature to a particular mode of manufacture. Woollen materials are 
 always more porous than linen fabrics, and it is mainly to this fact that the 
 one is ' warmer ' than the other. Anything which keeps the same layer of 
 ah' in constant contact with the body is warm, and when the atmosphere,, 
 though cold, is perfectly still, a thin flannel garment, or even a few layers of 
 the thinnest gauze, is sufficient to keep the body warm. Anyone who has 
 wrapped a newspaper round his legs in default of a railway rug has con- 
 vinced himself of this fact. 
 
 Nothing chills the body more than wind, and it is when we get wind and. 
 cold combined that thick clothing becomes necessary. In some of the high 
 Alpine valleys, where the sun is powerful and there is an absence of wind,, 
 it is surprising to see how comparatively lightly the inhabitants are clad,. 
 notwithstanding that the thermometer in the shade is down to zero. When,, 
 however, the wind gets up, warm thick clothing and furs become necessary. 
 To resist wind, clothing must be thick, or the layers of thin clothing must 
 be multiplied. Wind not only tends to renew the air hi contact with the 
 body, but it also quickens evaporation from the surface of the clothes, which 
 evaporation is in itself a great cause of the chilling of the body. The best 
 garments for resisting cold and wind are skins, with the woolly side nearest 
 the skin. Next to skins come thick shaggy woollen clothes, such as the Scotch 
 tweeds and Irish friezes, and the thick great-coats made of ' shoddy ' which 
 are worn by our poorer classes. After these come closely woven cloths. 
 Impermeable materials are amongst the warmest known, because they are 
 absolutely wind-proof, but they allow moisture to collect on the surface of 
 the body, and as the material is, from its absolute want of porosity, a com- 
 paratively good conductor of heat, and as the accumulated perspiration is 
 also a good conductor, the body is very liable to get chilled if they be worn 
 continuously. ' Macintosh ' clothing is of undoubted and great value for 
 certain purposes, especially for coachmen, with whom the exposure is great 
 and the tendency to perspiration small. They are very dangerous garments- 
 for use during active exercise. 
 
\ 
 
 CLOTHING 510 
 
 The Chinese* clothing is often in many layers, each layer being in cut 
 and form almost precisely like its fellow, and by diminishing or increasing 
 the various layers they are accustomed to meet the vicissitudes of their 
 climate. This is a sound principle, and one which we may often adopt with 
 advantage. It is recorded that Charles I. on the day of his execution, which 
 was bitterly cold, put on two linen shirts in order that he might not shiver ; 
 an act which might have been attributed by the populace to fear. 
 
 The porosity of woollen fabrics constitutes the chief but not the only 
 claim to their deserved popularity. It is possible, however, to imitate this 
 quality of wool by weaving linen or cotton in a loose porous fashion, these 
 fabrics then becoming, as heat- retainers, scarcely inferior to wool. Such 
 fabrics are now abundantly made, but we do not deem it our duty to bring 
 to the notice of the reader the wares of any particular tradesman. 
 
 The hygroscopic or absorbent power of the material for water is a very 
 important matter. It is commonly asserted that the hygroscopic qualities 
 of wool are far greater than those of the other fibres. Silk, as we have 
 seen, is powerfully hygroscopic, as also is jute, while cellulose, the basis 
 of all vegetable fibres, usually contains from 8 to 10 per cent, of hygroscopic 
 moisture. There can be no doubt that as a broad rule woollen fabrics absorb 
 or sop up far more moisture than cotton. This is partly due to the form in 
 which the manufactured article is woven. If we compare flannel with 
 calico, the absorbing power is most marked in the flannel, but if we compare 
 some very closely woven and fine woollen fabric with a piece of cotton bath- 
 towelling, the absorbent power may be perhaps greatest in the latter. It is 
 a question how far fabrics made of vegetable fibre may be made to equal 
 woollen fabrics in their power of absorption. A fabric which is really 
 hygroscopic will absorb a great deal of water without feeling wet, and this 
 power is to be distinguished from the power of merely holding water in the 
 interstices of the fibres. Common experience is probably sufficient to prove 
 that wool is far more hygroscopic than vegetable fibres, but these latter are 
 certainly more hygroscopic than generally is allowed. Flannel absorbs 
 moisture readily, and owing to its high hygroscopic power evaporation from 
 its surface is slow. When, therefore, a man sweats in a woollen garment 
 the garment does not get wet through, and the evaporation being gradual 
 the chilling of the body when exercise ceases is comparatively slight. When 
 a man sweats in an ordinary close-woven linen or cotton garment, the gar- 
 ment gets wet through and adheres to the skin, and the evaporation being 
 rapid the chilling of the surface is great, the body being, in fact, covered 
 with an ' evaporating lotion.' This latter evil may undoubtedly be to some 
 extent counteracted by a looser method of weaving the material. 
 
 For work in a climate 'like ours flannel is the safest material to wear, or 
 if cotton or linen be worn it must be loose- woven, so as to give some thickness 
 and porosity to the fabric. 
 
 In tropical countries flannel is too heavy a material, and linen or cotton 
 shirting is very generally worn, and great discomfort is experienced by its 
 getting soaked and adhering to the skin. This trouble has been met by the 
 Cliinese, who have been accustomed in hot weather to wear a net next the 
 skin and a thin silken garment over the net. The net, without increasing 
 the heat, prevents the sweat soaking into the upper garment, and the latter 
 from adhering to the skin, and nothing can be conceived more suitable for 
 tropical heat than such an arrangement. 
 
 For preventing the effects of solar rays upon the body the colour of the 
 fabric worn is all-important. White garments absorb least heat, and are 
 the best for the tropics. Next to white for resisting the effects of sun-heat 
 
520 HYGIENE 
 
 are tlie light shades of colour. Blue aiid black are the worst, and absorb 
 heat very readily. 
 
 We are now in a position to discuss the articles of clothing employed for 
 difl'erent regions of the body. 
 
 The head first demands our attention. Being provided with a natural 
 covering in the shape of hair, it really requires no additional clothing, as the 
 state of well-being enjoyed by the London Blue Coat boys sufficiently shows ; 
 but the usages of society render it inadmissible to go without a head-cover- 
 ing of some kind — at least out of doors — and a man who is accustomed to 
 wear a hat is tolerably certain to catch cold if he goes without one. 
 
 The hair of a man should be worn short, and the shorter it is the more 
 readily it is kept clean and tidy. When the hair is short it can be washed 
 almost as easily as any other part of the body, and in a town such as London, 
 where the atmosphere is laden with soot and dirt, the frequent Avashing of 
 the head is an absolute necessity. The custom of applying some pomade 
 to the bair is very general, and it is probably a good custom ; when the hair 
 is slightly oiled it can be the more readily combed, and the combing, brushing, 
 and oiling serve very materially, not only to keep the hair clean, but to free 
 it from vermin as well. A little oil or similar material having a basis of 
 glycerine or vaseline also prevents the drying of the skin of the scalp and 
 checks the tendency which the surface epithehum has to come off in the form 
 of scurf or dandrifl". A very greasy head not only looks disagreeable, but from 
 its stickiness it enables dirt easily to lodge upon and adhere to the hair. 
 The abuse of pomades is to be decried from every point of view ; but the 
 ' pennyworth of hair oil,' which forms so important an adjunct of the 
 Sunday toilet of the working classes, is not to be discouraged. 
 
 It is quite possible to go without a hat in any climate, and natives of the 
 tropics who wear the hair short and have no artificial covering for the head 
 do not seem to be liable to sunstroke, nor are their eyes dazzled by the glare 
 of the sun. 
 
 In very cold regions also the hair if tolerably thick is sufficient protec- 
 tion for the head, and might also be made to cover the ears ; but if the hair 
 be not thick, then a head-covering becomes a necessity, and, as a matter of 
 fact, most of the inhabitants of northern climates find it convenient to cut 
 the hair and cover the head with a fur cap having lappets for the ears. 
 
 For ordinary use in a climate like England the selection of a hat is not 
 a very important matter, the main consideration being the comfort of the 
 wearer. It is important to have a layer of air between the top of the head 
 and the crown of the hat, for in this way the effects of cold and heat are 
 ahke avoided. It is also advisable to have a certain amount of rigidity in 
 the hat as a protection for the head from the effects of falls or accidental 
 blows. The low-crowned hemispherical hat of felt with a brim sufficient 
 to protect the eyes from glare and to keep rain from running down the 
 neck meets most of the indications above mentioned, and its popularity ig 
 quite justifiable. The tall cylindrical ' chimney pot ' hat made of silk is by 
 no means a bad headdress, notwithstanding the abuse which is levelled at 
 it. It is not very heavy (at least it need not be), it has sufficient stiffness 
 to protect the head, and the large stratum of air between the head and the 
 crown of the hat is excellent. The comparative narrowness of the brim, 
 the cylindrical shape, and the smooth surface make it difficult to be blown 
 off, a point of no small importance. Its great drawback is its cost and the 
 ease with which it is damaged by rain. A shabby hat of this description 
 gives an air of shabby gentility, and there is nothing which more degrades 
 i.he appearance of a man than a mangy hat which has seen better days. 
 
CLOTHING , 521 
 
 Some of these hats are made to ' ventilate,' with the idea of keeping the 
 head cool. A drawback to the two varieties of hat mentioned is the difficulty 
 of keeping them clean, but in this respect the cylindrical hat is usually 
 better than the hemispherical ' deer-stalkers.' These catch the dust very 
 badly, and the combination of dust and rain spoils them very rapidly. Dust 
 lodges especially round the brim, and the brim is of such a shape that only 
 brushes of a very special make will clean it. Every traveller must have 
 experienced the shortcomings of these hats, and it is much to be desired that 
 the curl to the brim and the conventional bow of ribbon at the side may 
 some day be dispensed with. For comfort there is probably nothing better 
 than a soft felt ' wideawake,' but their crumpled appearance and the ease 
 with which the wind * takes ' them are to be reckoned among their dis- 
 advantages. 
 
 In very hot weather a white and very light ' chimney-pot ' is really a 
 first-rate headdress. A straw hat of a light colour is also a comfortable 
 thing in hot weather, but the generality of straw hats are too low in the 
 crown, which is often absolutely in contact with the top of the head. A 
 straw hat of the ' chimney-pot ' shape is comfortable, but not in favour 
 among aesthetic people. 
 
 A very important point in the choice of a hat is its weight, which should 
 be as small as is consistent with the other purposes for which the hat is 
 needed. A conventional black silk cylinder weighs about 6 oz., and the com- 
 mon round felt hat about as much. A white flannel cricketing cap weighs 
 between two and three ounces, and the Grenadier's ' bearskin ' about 35 oz. 
 
 There are a variety of hats for special purposes. For protection against 
 the direct rays of the sun there is probably nothing better than the turban, 
 its chief drawback being the trouble of adjustment. To avoid this the white 
 pith or cork helmet, with ventilating holes at the top and round the rim, has 
 been devised, and is said to be a most efficient protection. A further protec- 
 tion to the head is afforded by a gauze ' veil ' twisted round the hat and with 
 the ends falling over the nape of the neck in order to protect the medulla 
 oblongata from the direct action of the su.n's rays. The Boers of tropical 
 Africa wear felt wideawakes Avith broad brims, and the planters in tropical 
 America wear straw hats with wide brims. If the brim be not wide, then a 
 veil or ' puggeree ' becomes necessary. 
 
 The principles to be followed in providing a headdress for women are 
 different because the true headdress of women is the hair, and any additional 
 headdress is only for the purpose of keeping the hair clean and for adorn- 
 ment. When women take up masculine pursuits they usually adopt head- 
 dresses similar to those worn by men. Ladies' hats and bonnets are made 
 solely in compliance with the dictates of fashion, and there is no possibihty 
 of discussing them with any advantage. 
 
 With regard to the clothing of the body the main objects are — 
 
 1. To maintain the temperature and by preventing the loss of animal 
 heat to diminish to some extent the demands for food. Warm clothing is 
 economical, but it unfortunately generally happens that those who are un- 
 able to be warmly clad are also insufficiently provided with food, and these 
 two evils intensify each other. ' Starved with the cold ' is a very old expres- 
 sion, and one which has a basis of physiological truth, for if the body were 
 warm, the Avant of food would be less keenly felt, and vice versa. 
 
 2. To allow the chief heat-regulating mechanism (i.e. the evaporation 
 from the skin) to proceed with as little hindrance as possible. 
 
 3. To allow all muscular acts the greatest possible freedom, and to 
 avoid the compression of the body in so far as may be possible. 
 
522 HYGIENE 
 
 4. To protect the body from heat, cold, wind, and rain. 
 
 5. To disguise as little as may be the natural beauties of the human 
 figure. 
 
 The most important part of our clothing from the hygienic point of view 
 is that which we wear next the skin, the underclothing. The thickness of 
 this must vary with the season, from the stoutest flannel to the thinnest 
 gauze. ^Yool is probably the best material for all seasons, and if cotton or 
 linen be employed it should be loosely woven, so that it may entangle a 
 maximum, quantity of air in its meshes. In very hot weather or in the 
 tropics a net is an excellent form of under-garment. The ' cut ' of under- 
 clothing is most important, and the fashion which has lately come in of 
 making the under-vest to fasten on one shoulder is excellent, so that any 
 accidental exposure of the front of the chest to the wind is thereby 
 avoided. 
 
 Underclothing should fit so as to follow tolerably closely the outline 
 of the figure without impeding the movement of the arm. In winter it 
 should come well above the sternal notch and the sleeves should extend to 
 the wrists. It must not compress the thorax, abdomen, or arms. A recent 
 improvement in underclothing is the ' Combination ' garment, i.e. vest and 
 drawers in one. In this way the band for the drawers is avoided and the 
 necessity of compressing the abdomen by a band is done away ^vitll, as is 
 also the annoyance of a double or even a treble layer of material round the 
 loins. The perspiration at this spot when vigorous exercise is taken is often 
 excessive : the band of the drawers gets wet through and the risk of chill 
 when exercise is ended is considerable. Another advantage of this garment 
 is the lessening of the number of chinks through which the wind may gain 
 access to the body. A most important matter from a practical point of 
 view is the ease with which garments may be unbuttoned and adjusted so 
 as to obey the calls of nature with the greatest readiness, and in purchasing 
 ' Combination ' garments this point must receive attention. 
 
 The drawbacks of flannel underclothing are mainly two — viz. the irrita- 
 tion which they often cause on the skin, and their liability to shrink when 
 washed. Some persons are unable to tolerate flannel next the skin 
 because of the irritation which it causes. Such persons have usually a 
 quick circulation, and are not liable to chilliness ; but if great protection 
 is necessary wash-leather over silk is probably the warmest combination 
 obtainable. 
 
 The liability of flannels to shrhik in washing is more serious ; but this 
 drawback may be greatly reduced (a) by ' shrinking ' the flannel thoroughly 
 before it is made up and (5) by washing in cold or tepid rain water and 
 avoiding too much friction with the hand. Flannel garments should be 
 soaped on both sides and then rinsed by waving them to and fro in a large 
 quantity of cold soft water. It is asserted that in the tropics there is no 
 need to wash flannel. If a shirt be hung up to dry in the sun and thoroughly 
 beaten when dry it is said that its cleansing is thoroughly efl'ected and 
 that no foul odour clings to the material. 
 
 Underclothing should be frequently changed, but the necessary frequency 
 must depend upon the amount of sweating and the state of the skin, which 
 differs greatly in different individuals. If the skin be thoroughly cleansed 
 and rubbed every day a suit of underclothing may be worn for the conven- 
 tional week without contracting any animal odour, but this is only possible 
 when the weather is cold and the individual has taken no very vigorous 
 exercise to produce sweating. 
 
 In providing the outer and visible clothing of the body regard must be 
 
CLOTHING 523 
 
 had to the same principles which guide us in the provision of the under- 
 clothing. The principle of the survival of the fittest would lead one to 
 suppose that there is not much amiss with male clothing, for it has remained 
 substantially the same for the last sixty years. 
 
 The shirt is most comfortable when made of flannel or some soft mixture 
 of wool with other fibres. A flannel shirt over woollen underclothing is very 
 warm in winter, and worn alone without underclothing is the perfection of 
 a dress for the summer. 
 
 In the dirty atmosphere of London a flannel shirt soon gets grimy and 
 looks slovenly and dirty. If, therefore, it be worn in town, mild deceptions are 
 practised in the matter of collar and wristband, and the front is concealed with 
 a scarf. The highly starched linen shirt, with its polished front, collar, and 
 wristbands, has no hygienic merit except its cleanly appearance, in which it is 
 unsurpassed. There probably never has been a garment so capable of making 
 a man look clean and smart at a comparatively small cost as the modern shirt. 
 The appearance of cleanliness holds the first place from an aesthetic point 
 of view, and that which looks clean and fresh is sure to be popular. A 
 Londoner without being thought excessively dandified or extravagant may 
 have his two clean shirts per diem, and with them he probably looks cleaner 
 and fresher than he would in the costly lace ruffles which were in vogue in 
 the eighteenth century. 
 
 The waistcoat is a most useful and valuable article of clothing. Origin- 
 ating as a very voluminous garment — apparently in the time of Hogarth 
 (about 1738) — it got smaller by degrees until it reached its present very 
 modest proportions. The waistcoat does not (or rather should not) impede 
 the movement of the body in the smallest degree, and it can be regulated 
 to suit the season and the occupation with great readiness. Between the 
 low-cut white waistcoat which is worn indoors and the high sealskin 
 waistcoat lined with flannel we have all gradations of warmth, and there is 
 no doubt that this garment is of the greatest jDractical utility. In the 
 present day coats vary immensely in ' cut ; ' but the ' cut ' of the waistcoat 
 scarcely varies at all. It is difficult to imagine what we should do without 
 the waistcoat pockets, which are at once safe and convenient, 
 
 A ' sleeved ' waistcoat is a very warm garment, and a very useful one for 
 those who have to encounter a mixture of active work and inactivity, such 
 as railway porters, who would be much inconvenienced by a coat, and who 
 are too much exposed to weather to work 'in their shirt-sleeves.' 
 
 What can be said of coats, except that they should fit and allow abso- 
 lute freedom of movement to the arms, diaphragm, and abdominal muscles 
 "without forming creases ? 
 
 The writer is not one of those who is disposed to cavil at modern male 
 attire. In the main it is comfortable and sensible, and it is very hard to 
 beUeve that the Cavalier of the seventeenth century, in all the glory of gold, 
 velvet, feathers, and curled hair, had any advantage in the matter of appear- 
 ance when compared with the spotlessly clean and exquisitely neat gentleman 
 of the nineteenth century. Ostentation in the matter of dress on the part 
 of a man would at the present day merely raise a laugh. The duke and his 
 butler are both contented with a white shirt and a black suit of clothes, and 
 the fact that the wealthy are content with the same simple clothing as tbe 
 comparatively poor may, we think, be taken as evidence that our universally 
 adopted garments have reached a high degree of perfection, from the point 
 of view of comfort and suitability. 
 
 It is needless to say that coats vary in accordance with the work to be 
 done. Tails and skirts are necessary from an aesthetic point of view, when. 
 
524 HYGIENE 
 
 with advancing years the figure becomes protuberant. They are also very 
 useful as furnishing space for pockets. Tails and skirts hamper movement, 
 and do not materially increase the warmth of the garment. One of the 
 warmest and best garments for winter wear is the 'pilot' jacket, which 
 buttons up and affords first-rate protection to the chest and abdomen, while 
 it does not in any degree impede the movement of the legs. 
 
 ^\'llen a garment is worn for warmth it is all- important to protect the 
 abdomen and chest. If this be efficiently done it is not so necessary to pro- 
 tect the limbs. The Highland kilt is said to be a very warm garment, 
 because it extends nearly up to the level of the armpits, and being thickly 
 pleated it affords a very great deal of protection to the trunk. 
 
 From a purely hygienic point of view, however, the bare Imees of the 
 Highlander are as indefensible as the ' bearskin ' of the Grenadier. 
 
 For very cold weather and for travelling, fur-lined coats are much used. 
 The protection they afford is enormous, but they are too heavy for walking 
 in. The same maybe said of the modern 'ulster,' which is a warm but 
 very cumbersome garment. 
 
 In very variable climates, such as the south of Europe, where the extremes 
 of temperature are very wide apart and the fluctuations sudden, it is usual 
 to wear a cloak loosely hung upon the shoulders, in order that the body may 
 be enveloped by it at a moment's notice should the occasion arise, as it fi-e- 
 quently does, especially at sunset. 
 
 The clothing of the legs, as far as man is concerned, resolves itself into 
 a question of tro2isers or knee-breeches. 
 
 Trousers have the great advantage of compressing the body at no point, 
 and of allowing the greatest freedom of movement to the leg. The great 
 freedom of movement in trousers is shown by the fact that they are uni- 
 versally worn in the cricket field, where the body is called upon to undergo 
 very sudden changes of position. Cricket is a game which involves the 
 keenest competition, and concerning the dress to be worn while playing 
 cricket there are no laws or regulations. It is tolerably certain that no point, 
 however small, which could give one side an advantage over the other would 
 be neglected. The fact, therefore, that the dress of cricketers is practically 
 the same the whole world over is very important, and constitutes the 
 strongest testimony that the trouser places no appreciable check upon the 
 movements of the body. In the cricket field, where the trousers worn are 
 ' of very light weight and there is nothing worn beneath them, a buckle to 
 draw them in over the hips is sufficient to keep them from falling. At other 
 times it is necessary to support the trousers with something more secure, 
 and to this end ' braces,' which pass over the shoulder, are now universally 
 adopted. There is no doubt that braces are preferable to a belt, inasmuch 
 as they do not compress the abdomen, and scarcely interfere at all mth the 
 movements of the limbs. 
 
 The drawback to trousers consists in their liability to get dirty and wet 
 round the bottom, and the tendency of fashionable tailors is to make them 
 decidedly too long. This fault in trousers is so easily met by turning up the 
 ends that it scarcely deserves mention. Nevertheless, trousers might be 
 worn shorter than at present with obvious advantage. 
 
 The old-fashioned pantaloon, or trouser which buttoned round the lower 
 part of the leg, had some advantages, and when worn with the high ' Hes- 
 sian ' boot was an excellent arrangement for sloppy, dirty weather. The 
 boots could be easily removed and replaced by clean shoes ; but in spite of 
 these advantages the pantaloon had a short reign, and it is certain that it 
 hampered the movement of the leg more than the trouser. 
 
CLOTHING 525 
 
 Knee-breeches, or knickerbockers, constitute an excellent garment for 
 walking, from the point of view of cleanliness and comfort. They involve 
 compression of the leg below the knee in order to support the stocking, and 
 the compression is seriously felt if the knee be bent beyond a right angle 
 and the wearer suddenly assume a squatting position. 
 
 The knickerbocker and the pantaloon as compared with the trouser have 
 the obvious disadvantage of possessing more buttons and fastenings, and 
 the fact that the legs can be clothed quicker in socks and trousers than 
 in any other garment, and the additional fact that the trousers have fewer 
 buttons to come off than any other garment, are practical points which do 
 much to maintain the popularity of the trouser. The great popularity of 
 the knickerbocker among touring pedestrians is to be attributed to the small 
 space occupied by a pair of stockings in a knapsack and the ease with which 
 stockings can be changed when the journey is over. 
 
 For cycling, knee-breeches and stockings are almost universal. In this 
 mode of progression the flexion of the knee is seldom excessive, and the loose 
 end of the trouser is liable to hitch in the mechanism of the cycle. These 
 facts, as well as others, make them popular for cycling. 
 
 For rowing, which necessitates an attitude suggestive of the letter N, 
 any compression round the knee is not to be thought of. The Highland 
 kilt undoubtedly allows great freedom to the legs, especially the knee- 
 joints, and those who wear it habitually protest that it is not cold. For 
 walking through brushwood or covert of any kind, both the skirt of the kilt 
 and the naked knee are alike objectionable. 
 
 The principles which hold good with regard to women's clothing do not 
 differ essentially from those which should regulate men's attire. Volumes 
 have been written on this subject, but, except in the top garment, the ' dress,' 
 it does not appear that women's attire has altered more than that of men. 
 It is an essential part of all costume for either sex that it should readily 
 admit of an immediate obedience to the calls of nature, and the main cause 
 of the difference of costume in the two sexes is the difference in the anatomy 
 of the urethra. This is a point which is, of course, kept in the background in 
 all popular treatises. We do not intend to discuss the relative advantage of 
 the single and the divided skirt, which is a matter which women must 
 regulate for themselves. Again, on the question of ' stays ' or corsets, there 
 would appear to be room for two opinions. 
 
 There can be no doubt that any undue compression of the waist is 
 thoroughly bad and most mischievous. If the respiratory and abdominal 
 muscles be not free to act, they will not develop properly, and if the waist 
 be 'laced in,' the heart, lungs, liver, and stomach are thrust upwards and the 
 intestines forced downwards. Discomfort after meals and serious dyspeptic 
 troubles must and do result, and these are followed by anaemia. The com- 
 monest symptom of dyspepsia in a woman is pain under the left breast ; a 
 symptom of which men rai'ely complain ; and the reason for this difference of 
 symptom of the same disease in the two sexes is due probably to the dis- 
 placement of the stomach by the stays. The chief defence of the stays is 
 found in the statement that they are necessary for the support of the petti- 
 coats and skirts. There can be no difficulty in supporting the skirts from 
 the shoulders, but fashion steps in to prevent this ; and there can be no doubt 
 that the fashion of appearing with naked shoulders on state occasions prevents 
 the general adoption of what seems to be a sensible reform. For one who was 
 accustomed to wear braces, or some substitute for them, the ordeal of going 
 to a high ceremony without them would be most trying. A lady's full dress. 
 
526 HYGIENE 
 
 which involves a hotlice having practically nothing over the shoulders, must 
 take its bearings from the waist. 
 
 The weight of winter skirts and petticoats, especially with a brocaded 
 * train ' yards long, must be prodigious, and were it not for a stiff corset firmly 
 poised upon the hips, the carriage of such gear without shoulder-straps would 
 be impossible. 
 
 The articles of clothing for the feet — socks and stockings, boots and shoes 
 — probably influence our comfort more than any other portion of our attire. 
 
 Like many other articles of clothing, they are said to be unnecessary, and 
 we are told that the naked human foot soon gets accustomed to variations of 
 temperature, and ' the thousand natural shocks ' which are inseparable from 
 labour and locomotion. 
 
 Be this as it may, it has been the custom of all civilised races from re- 
 motest periods to clothe the foot, and there is no probability that this custom 
 will be departed from. 
 
 In considering this subject we must deal with it in the first instance in 
 relation to utility, i.e. to foot-coverings, in which a man can work or take 
 vigorous and active exercise. As to ' dress ' boots and shoes, articles which 
 are worn mainly for decency or adornment, and in compliance with the dic- 
 tates of custom, that is another matter upon which one may treat lightly. 
 
 In considering ' foot-coverings ' we must remember that the boot is only 
 the outer covering of the foot, and that within it is the stocking or sock. 
 With regard to the stocking or sock, this should always be of a woollen mate- 
 rial, or of a mixed material in which wool predominates. The hygroscopic 
 qualities of wool cause it to absorb the perspiration of the foot, and its elasticity 
 as a woven fabric and its power of stretching make it less liable to form creases 
 and to give rise to the consequence of creases, i.e. blisters and corns. A sock 
 should ' fit,' i.e. it should have in its material neither poverty nor riches ; it 
 should not cramp the foot, and should form neither folds nor creases. Its 
 substance must vary with the time of year, the work to be done with the foot, 
 the kind of boot to be worn, and the fancy of the owner. A sock should be 
 without any projecting seams. Eibbed stockings or socks are comfortable, 
 and allow some slight circulation of air between the sock and the boot. 
 Socks may be made ' right ' and ' left,' and when thus made they undoubtedly 
 fit more accurately ; but this is perhaps an unnecessary refinement, as there 
 is always room to spare in the toe of a sensibly made boot above the fourth 
 and fifth toes, and if there be a little redundancy of fabric at this point it 
 causes no inconvenience. When very thick winter socks are worn it may be 
 an advantage to have them ' right ' and ' left.' 
 
 A greater refinement than having the socks right and left is to have 
 them digitated, with compartments for each toe. This may be necessary for 
 those who have pathological conditions of the feet, such as soft corns between 
 the toes, or an inordinate tendency to perspiration between the toes. If 
 socks be digitated, then accuracy of fit becomes doubly necessary. Again, a 
 woollen digitated sock would probably not be very comfortable after a few 
 washings and darnings. 
 
 There are those who maintain that even if boots be worn socks and 
 stockings are unnecessary. If socks be not worn the boots must be very well 
 made and perfectly free from projecting internal seams or anything else likely 
 to rub against the foot. If the boot be suitably made of supple leather, and 
 if the foot and boot be greased internally, it is probable that walking may 
 be accomplished with great comfort, and if the boot be kept clean inside as 
 well as out (i.e. if a filthy, blacking-bedaubed hand be not inserted into it for 
 
CLOTHING . 527 
 
 cleaning, as too often is the case), the foot will wash perfectly clean, and no 
 staining or galling will result. If no socks be worn, it follows that the boot 
 may be slightly smaller and lighter, which is an advantage during a long 
 walk ; but when the pedestrian halts, especially if he halts in a cold place, 
 such as a mountain top, the feet are apt to chill, because leather is a good 
 conductor of heat. If, however, the pedestrian is not going to incur any 
 such risks, and can change to a pair of socks and shoes when the walk is 
 over, it is probable that there are many advantages in having no socks or 
 stockings. For this practice to be successful, the boots must be first-rate and 
 must fit accurately. When pedestrians wear roughly- and ready-made boots, 
 as is the case with soldiers, a sock is absolutely necessary, and it is said that 
 those who wear no socks are in the habit of wrapping a piece of linen round 
 the toes to preserve them from bruising. 
 
 If no socks be worn the boot must be rather high in the upper, and must 
 fit well round the ankle, so as to prevent dust or small stones finding an 
 entrance to the boot. 
 
 For indoor wear upon carpets there is no objection to socks of linen, 
 cotton, silk, or any material which the wearer fancies, provided he be not 
 liable to cold feet, in which case ' merino ' is probably the best material. 
 Cold feet are to be avoided, especially at night, as if the feet get chilled there 
 is apt to be an undue supply of blood to the head, and sleeplessness very 
 ■commonly results. As to the colour of socks, the wearer may follow his fancy 
 provided they be properly dyed. Some years ago there were reported cases 
 of eczema of the legs which resulted from wearing ' magenta ' socks dyed 
 Avith an aniline product. In this instance the real cause of the eczema was 
 the employment of an arsenical compound as well as the aniline compound 
 in the process of dyeing. 
 
 When stockings are worn the question of ' garters ' or some substitute 
 has to be considered. Any compressing band round the leg is very un- 
 desirable, and it is advisable, especially for children and growing persons, to 
 use ' suspenders ' for the stockings rather than garters. If garters be worn, 
 there is nothing better than the old-fashioned knitted garter, which is a very 
 good compromise between the requisite elasticity and firmness. Garters 
 must be worn below the knee, as, if they be placed above the knee, any strong 
 contractions of that joint must work the stocking from beneath the garter, 
 and the garter, when worn above the knee, must be drawn inordinately tight 
 in order to prevent such a mishap. 
 
 Next as to boots, the best material is probably that which has been 
 mainly used for centuries, viz. leather. Good leather is very pliable, and is 
 hygroscopic and absorbent, so that perspiration is absorbed and slowly given 
 off again. Leather, too, is very durable, and nothing wears better for the sole 
 of a boot than old-fashioned English oak-tanned leather, although it is 
 doubtful if the same thing can be said for some of the chemically prepared 
 substitutes for that article. Leather is sufficiently waterproof for most 
 purposes, and a stout, well-made boot, especially if it be greased, will keep 
 out anything but very excessive amounts of moisture. 
 
 Impermeable materials are very undesirable for boots, and no one who 
 has tried to walk long distances in ' patent leather ' boots would wish to 
 repeat the experiment. In all cases the perspiration absorbed by the inside 
 of the boot must be able to be given off again from the outside. 
 
 India-rubber is a very undesirable material, especially for the uppers, 
 although there is no objection to it for purposes other than walking, such as 
 standing in water for fishing, &c., and for wearing on board ship when the 
 decks are wet. 
 
628 HYGIENE 
 
 The writer was lately consulted by a gentleman who was troubled by 
 swelling of the feet, and as there was no kidney disease, or heart disease, or 
 any detectable cause for local obstruction to the circulation, the cause of the 
 swelling was for a time a mystery. On questioning him it turned out that he 
 had been for some time in the habit of walking about his farm in ' deck 
 boots,' that is, boots made of india-rubber lined with green baize, and this 
 was the probable cause of his trouble, the feet and legs having been practi- 
 cally poulticed by his hot, impermeable boots for many hours daily. These 
 boots were discarded and the swelling disappeared. 
 
 Coarse canvas is now very often used for the uppers of lawn tennis 
 shoes, and there is no objection to this, but canvas is unsuitable for boots 
 meant for hard wear, as it does not resist moisture sufficiently. 
 
 The soles of boots are not unfrequently made of india-rubber or gutta- 
 percha, and although the objections to the use of the material are not so 
 great as when the uppers also are made of it, it is probably inferior for soles 
 to the time-honoured leather. 
 
 Volumes have probably been written on the proper shape for boots, but 
 when it is said that a boot should fit the foot accurately what more can be 
 said ? The shape of the sole of a boot should be taken by drawing a pencil 
 round the outline of the foot, when the bootmaker's ' patient ' is standing up, 
 so that the sole may be big enough to support the fully expanded foot. That 
 the line of the first metatarsal bone and the phalanges of the big toe should 
 be straight goes without saying. When we say that a boot should fit, we 
 mean that, without being loose, the foot should have room to move in it, and 
 on putting on a new pair of boots the wearer ought to be able to move all 
 his toes with freedom. Not only should the lower part of the boot fit, but 
 the upper part also. This often is not the case, for even in what are called 
 ' bespoke ' articles the upper is not unfrequently ' ready-made,' and is merely 
 the nearest approach to a fit which the bootmaker could procure. It is un- 
 doubtedly true that ' ready-made ' boots may fit accurately, but it is only a 
 happy chance if they do so, and seeing that the contour of the foot is not 
 precisely the same in any two individuals, it follows that if a man have tender 
 feet his best course is to go to a first-rate bootmaker and have the boot made 
 for him throughout. Keady-made boots have this fault, that the unintelligent 
 steam machinery which turns them out does not consider the endless varie- 
 ties in shape which the human foot presents. 
 
 Boots which do not fit cause deformities of the feet, and especially in early 
 life. Among the Scotch and Irish peasantry the children of quite respectable 
 parents wear no boots, and this causes a proper development of the foot 
 during the periods of active growth, and the feet are free from corns or 
 bunions, and the liability to chilblains is probably less if the children be well 
 nourished. Undoubtedly when such children have to adopt boots they pass 
 through some discomfort, but their chance of being properly fitted and not 
 pinched is probably greater than among those children whose feet have 
 become deformed by improper boots. 
 
 Boots are a great expense to the poor, for it is doubtful whether children 
 grow out of their boots or wear them out the more quickly. This often 
 results in their being provided from economical reasons with boots which are 
 too heavy and too big, and thus their exercise is often hampered and their 
 feet often bruised. 
 
 Children should, if they wear boots, have them renewed, not only in ac- 
 cordance with the wear of the boot, but also with the growth of the child. If 
 this be not done the foot gets compressed and distorted, and the toes have 
 a tendency to overlap, and chilblains are common. Growth does not stop 
 
CLOTHING 529 
 
 much, if at all, before twenty years of age, and sometimes continues after that 
 period, so that young ladies and youths should have great attention paid to 
 their boots in order to prevent troubles which may last them through life. 
 
 From some points of view shoes are better than boots, as the latter are 
 liable to compress the muscles and tendons in the neighbourhood of the 
 ankle, and so weaken them and prevent their proper development. The cause 
 of ' weak ankles ' is to be found as often as not in an unwise compression of 
 that region, and although a firmly laced, well-fitting ankle boot undoubtedly 
 supports the ankle, it also prevents the ankle from learning, so to say, to 
 support itself. Shoes have the disadvantage of allowing sand and dirt to get 
 in over the upper edge, and there is no doubt that when shoes are worn the 
 socks are dirtier after a long walk than when ankle boots are worn. When 
 shoes are worn for heavy work some sort of gaiter is necessary, but this intro- 
 duces a complication into dress which occupies time in cleaning and putting 
 on and off, so that, all things considered, it is probable that ankle boots, which 
 are now so generally worn, are for ordinary purposes the best. We are 
 seldom wrong in concluding that that which is generally worn, and is not 
 worn merely in obedience to a caprice of fashion, has some very solid and 
 practical merits. 
 
 For hard walking, high boots such as come up to or approach the knee 
 are too hot, but for slow walking, such as partridge shooting in wet turnips, 
 the high boot which laces up the middle, and which is really a boot and gaiter 
 in one, has undoubted merits. 
 
 The so-called ' Wellington ' boot or ' half Wellington ' with a high upper, 
 and which has no fastenings, but merely slips on and off, has great advantages 
 in the fact that the wearer is never the victim of broken laces or absent 
 buttons. Their drawback is the heat of them and the fact that unless they 
 be unduly loose they are apt to be very difficult to get on and off after a 
 prolonged soaking in wet ground. The German Army boot is, it is right ta 
 say, of this pattern. 
 
 The sole of a boot should be wider than the foot, and if the boot is to be 
 used for heavy walking this excess of breadth in the sole should be consider- 
 able, so as to serve as a protection from rocks and loose stones. The thick- 
 ness of the sole must vary according to the work to be done. In a variable 
 climate like ours it is always advisable to wear soles of some substance, just 
 on the same principle that it is wise to be provided with an umbrella even if 
 the sun be shining. The thicker the sole, the less phant it is, and a rigid 
 sole is bound to wear out, at the toe especially, for in walking the heel is 
 first placed on the ground and the last act is the final push against the 
 ground with the point of the big toe, and if the sole be too thick to bend the 
 toe must get worn out long before the sole at large. The outside of the heel 
 and the inside of the toe are the two normal points of main wear in a boot, 
 the centre of the sole (slightly on the outside) being the third point. Man 
 shows his descent from the ape by walking slightly on the outer side of his 
 feet. Thick or ' clump-soled ' boots are generally made thin in the waist from 
 the mistaken notion that this gives pliancy to the sole. As a matter of fact, 
 the waist of a boot has no tendency to bend at all, the line of bending being 
 further forward exactly beneath the crease which forms on the top of a boot 
 which has been worn, that is^ a line extending obliquely from the metatarso- 
 phalangeal joint of the big toe to the corresponding point of the little toe. 
 Boots have been made with a sort of hinge in the sole taking the course of 
 this line, but as the strength of a sole is to be measured by the strength of 
 its weakest point, and as the ' hinge ' is necessarily a weak point into which 
 moisture and grit are liable to find their way, it is doubtful if this plan is 
 
 VOL. I. M il 
 
530 HYGIENE 
 
 practically of much use. The wear and resisting power of a sole is to be 
 measured more by the thickness of the individual layers of leather than the 
 thickness of the sole as a whole. For a sole may be very thick and yet be made 
 mainly of rubbish. The middle layer of the three which form the sole of an 
 ordinary ' double ' (i.e. really treble) soled boot is often of inferior quality, and 
 directly the outer layer gets worn the middle layer readily absorbs moisture. 
 A stout single sole (i.e. a sole of two layers) is a better protection than one 
 of three thinner layers, and has the advantage of being lighter. It is doubtful 
 if for heavy work a moderately heavy boot is any disadvantage. An ordinary 
 pair of walking boots weigh about two pounds, a thick pair nearly three, and 
 a pair of very heavy shooting-boots with nails weigh about three and a half 
 pounds. This weight is nothing for the legs of a moderately active anan, and 
 if the ground to be traversed is rough a pair of big boots is a great advan- 
 tage, especially in coming downhill. Professional walkers and professional 
 mountaineers all adopt heavy boots. It may be well to remark that big hob- 
 nails have certain advantages, of which the increased ' wearing ' power is only 
 one. They give a very firm hold of the ground and are very necessary for 
 mountaineering, and especially on slippery grass slopes. They are the only 
 things which hold satisfactorily to a ' greasy ' pavement. They raise the 
 sole of the boot off the ground and help very materially to keep the foot warm 
 and dry, and further they are very clean ; and in walking on sloppy ground 
 (such as a pavement during a thaw), they splash very little. They should 
 always be worn by those who are obliged to be out in all weathers, such as 
 soldiers, policemen, postmen, &c. To obtain these results only a very few nails 
 are necessary, but they must not be too few, because if the points of pressure 
 of the nails are not sufficiently close they are apt to make their pressure felt 
 upon the foot itself and cause sores or corns. Again, if the nails be too far 
 apart to give each other some mutual support they are sure to kick out. 
 Nails are now made with projections in the head which stick into the sole, 
 and such nails are very firm. The plan of inserting nails in groups of three, 
 so that each nail is supported by the other two, is also a very good one. 
 ScreAV nails, again, are absolutely firm, but necessitate a great thickness of 
 leather to hold the screw. 
 
 The heels of boots have been much written about, and it is tolerably certain 
 that they are no help to progression, and from the purely physiological point 
 of view are useless. The heel of a boot is the first point to wear out whether 
 the heel be raised or not, and as the ordinary raised heels are very easily 
 repaired they are economical, and it is probably due to this fact that the 
 fashion of ' heels ' has lasted for centuries. They serve also to keep the foot 
 off' the ground and help to keep it dry, and they also probably serve to pre- 
 vent splashing, which is a very legitimate aesthetic and practical consideration. 
 The heels of boots should most certainly be low and broad, and a high taper- 
 ing heel which lessens the basis of support for the body is absolutely indefen- 
 sible. The inordinately high heels which are worn by some ladies, by raising 
 the hind part of the foot, diminish its apparent length, and this undoubtedly 
 is the cause of the persistence of this fashion. It is needless to say that 
 they cause the foot to look deformed and make active locomotion impossible 
 by effectually taking away the power of ' spring ' from the foot, and by throw- 
 ing undue pressm'e on to the unfortunate toes which are crowded together in 
 this irrational foot-gear. High heels increase the apparent height of the 
 individual and they apparently are much admired by men, which probably 
 accounts for their almost universal use upon the stage and in other public 
 places. 
 
 It needs hardly to be said that dancing in any true sense is impossible 
 
CLOTHING 531 
 
 in high-lieeled shoes. The last of the famous dancers who really dis- 
 played the true poetry of motion was probably Madame Taglioni, and it is 
 perhaps worth recording that this lady always wore a pair of simple absolutely 
 pliant satin slippers without heels of any kind, and fastened by slender elastic 
 bands. The modern ballet shoe has an absolutely rigid toe, so as to enable 
 the danseiise to perform the pas cles pointes, which seems to be the sine qud 
 non of modern stage dancing, which, whatever may be its merits, most 
 certainly is not dancing. 
 
 If the object of foot-gear be mainly to keep the foot warm, tbon un- 
 doubtedly woollen materials or fur linings are advisable. 
 
 The Chinese shoe, which is admirable in this respect, has a sole about 
 an inch thick, made of layers of thick paper or felt, and by this means the 
 Chinaman, who seldom, indulges in very active exercise, and who never 
 employs carpets in his house, is enabled to keep the foot comfortably warm, 
 even in the depth of winter. Slippers made of felt are admirable for keeping 
 the feet warm indoors, as is also the slipper with a hempen sole, which is so 
 largely worn in the Basque Provinces and elsewhere in the south of Europe. 
 A cloth or woollen top to ihe boot is a most comfortable arrangement for 
 winter. 
 
 The wooden shoe, or sabot, and the Lancashire clog, which is a sabot shod 
 with iron, is a very cheap and serviceable foot-gear for working in sloppy 
 places, and it has the advantage of being put on and off in a moment. The 
 old-fashioned patten, which used to be so much worn by women engaged in 
 sloppy work, is also a very admirable and simple contrivance for keeping the 
 feet dry under certain conditions. 
 
 The American overshoe and the ' golosh ' need only to be mentioned as 
 very useful things for temporary purposes, but quite useless when rapid or 
 prolonged locomotion is required. 
 
 Before leaving the subject of foot-gear, it may be mentioned that it is 
 very advisable, and especially for delicate persons, to be careful to change the 
 shoes and stockings after active exercise, as the cold produced by the 
 evaporation of the perspiration is very liable to chill the feet. If the feet 
 get wet in the course of exercise it need hardly be said that this precaution 
 is doubly necessary. There is little danger in getting wet feet or in being 
 wet through provided the pedestrian keeps moving, but if he neglect to 
 change his clothing immediately his exercise ceases he is sure to get ' a 
 chill.' 
 
 Our remarks hitherto have been solely directed to working boots, but 
 perhaps in a subject of so much importance it may be permitted to say a 
 few words on the aesthetic side of the subject, and be it remembered that 
 trained esthetic faculties are the true aids of the hygienist, because the first 
 canon of assthetic law with regard to clothing must be cleanliness. No 
 article of clothing which is not clean can possibly please the eye, and there- 
 fore the first consideration with regard to boots is facility for cleaning. 
 As the English stand almost alone among European nations in the art of 
 boot cleaning, it is to be presumed that our common methods in that respect 
 are sound ; and indeed it is hard to imagine anything more satisfactory to 
 the eye than a black leather boot thoroughly pohshed with 'blacking,' 
 which is a carbonaceous mixture, the fine particles of which can be made 
 to shine by brushing. 
 
 A material which makes a boot appear clean and brilliant without inter- 
 fering with its porosity or pliancy has qualities which are of great value, 
 and if it had not the disagreeable property of soiling the hands and clothing 
 which come in contact with the boot, its popularity would be assuredly 
 
532 HYGIENE 
 
 permanent. Xo varnishes can be regarded as in any sense a substitute for 
 blacking, for in the first place they destroy the porosity of the leather, and 
 in the second place the application of layer upon layer makes the surface 
 of the leather uneven, and suggests filthiness rather than cleanliness. 
 Varnishes do not soil the hands, "which is some advantage. 
 
 Bootmakers do not sufficiently consider the comfort of the wearer in small 
 matters. Why should new boot-laces be soaked in carbon and grease up to 
 their very ends ? Why should not that part of a lace which is touched by 
 the hand be left free from soiling impurities ? 
 
 There is, just now, a fashion for boots made of brown and ' tan ' leathers,, 
 a fashion which had its origin among military men engaged in tropical cam- 
 paigns. The light tint of these leathers make them cool for the feet, and 
 this fact, combined with cleanliness, has done much to make them popular. 
 From an a;sthetic point of view they appear to be surpassed by polished 
 black, which gives to even an old boot an appearance of absolute cleanliness, 
 which the tan leather never has, and least of all when old and stained. 
 Nothing makes the outline of a foot appear so small to the eye as when it is 
 clothed in black, with a polished surface which reflects the light. 
 
 A boot to look well should show the outline, and should not conceal the 
 movement of the foot, which is one of its chief beauties. The beauty of a 
 foot consists, not only in its outline, but in its elastic pliancy and its proper 
 proportion to the rest of the body. ' Small feet ' are considered a beauty, 
 but there can be no doubt that a foot should bear a due proportion to the 
 body. A man with inordinately small feet is apt to have an appearance of 
 eflt'eminacy and feebleness, which is not pleasing to any healthy esthetic 
 sense ; and when we see a man with his feet crammed into tight high-heeled 
 boots, so that he is compelled to ' strut,' instead of walk, it is hardly pos- 
 sible for our ' first impression ' not to be one of slight contempt. 
 
 As boots and shoes necessarily add to the apparent size of the foot, it is- 
 very important that nothing in their design should unduly add to this 
 aesthetic drawback. To this end foot-gear should be uniform in colour. A 
 mixture of tints and elaborate patterns (checks, &c.) undoubtedly make the 
 foot look large, as do also big bows and rosettes. 
 
 The weight of clothing is considerable, but necessarily varies with the 
 season of the year. The following are the weights of the ordinary civil 
 attire of a man weighing 133 lb., and 5 feet 6h inches in height : — 
 
 Lb. oz. Lb. oz. 
 
 Socks . . from 1^- to 4 
 
 Under-vests „ 3i „ 13^ 
 
 Under-drawers „ 4| „ 12| 
 
 Shirts , 9J „ is" 
 
 Trousers „ 15 „ 2 2 
 
 Waistcoat „ 7 „ 121 
 
 Coat „ 2 5i „ 3 1 
 
 Boots „ 1 7" „ 3 
 
 CoUar „ OJ „ 0| 
 
 Handkerchief „ 1^- „ 1^ 
 
 Cravat „ l" „ 2 
 
 Total weight of clothes .69 11 14| 
 
 Thus it is seen that the weight of clothes which may be worn in summer 
 and winter varies considerably. 
 
 When out of doors there are considerable additions to be made,, 
 thus : — 
 
CLOTHING 
 
 Lb. oz. tM. 
 
 Hat from 2 to 7 
 
 Scarf 
 
 Gloves 
 
 Overcoat ....... 
 
 Umbrella ....... 
 
 Keys, money, watch, &c 
 
 „ 3 
 
 o:i „ 4 
 
 2 12i- „ B 
 
 i i! „ 1 i| 
 
 2 10 „ 2 10 
 
 Total extras . 6 11 12 9J 
 
 Thus it appears that a man in walking attire in the winter may liave to 
 •carry as much as 24 lb. 8^ oz., or rather more than 18 per cent, of tlie weight 
 of his body. Of this weight only 7 oz. is carried on the head, and 3 lb. 4 oz. 
 •on the feet, while 2 lb. 14| oz. are suspended from the shoulders and partly 
 supported by the hips ; while of the remainder 16 lb. 9^ oz. are carried 
 entirely on the shoulders and 1 lb. 5| oz. are carried by the hands. 
 
 There can be httle doubt that the shoulders are best able to carry the 
 maximum weight, and the writer is not prepared to offer any adverse criticism 
 .to the distribution of the weight of the clothing given above. The pedes- 
 trian often has to carry a knapsack, and the problem of how best to distri- 
 bute the weight arises. Heavy weights are carried after a little practice on 
 the head with great ease, and it is probable that the carrying of weights upon 
 the head is a sure way of producing an upright carriage and graceful figure. 
 If the weight be divided between the head and shoulders by means of an 
 apparatus which may be seen any day in Covent Garden Market, very heavy 
 burdens may be carried with comparative ease. Such methods are, however, 
 impracticable for the traveller, and the shoulders and hips are the points 
 upon which a knapsack is best supported. The old fashion of carrying the 
 military knapsack entirely upon the shoulder and fixing it by cross-belts over 
 the chest, undoubtedly compressed the thorax, hampered the breathing, and 
 produced irritation of the heart. 
 
 Straps passing from the top of the knapsack over the shoulders and then 
 xeturning to the bottom of the knapsack by bending round the armpits are 
 found to be practically serviceable, and they keep the knapsack steady both 
 for quick and slow time of march and in going up or down hill. 
 
 A very excellent form of knapsack is one consisting of two bags, of which 
 one lies against the upper dorsal region, and the other in the hollow of the 
 loins. They are united by straps passing from the top of the upper bag over 
 the shoulders and then obliquely downwards in the axillary region to the 
 top of the second bag. These bags are then supported partly on the shoulders 
 and partly on the sacrum, and as one bag balances the other the weight is 
 well divided. The only drawback is their tendency to bump about when the 
 traveller is coming downhill, a tendency which is easUy checked by stays 
 passing to a waist-belt. 
 
 A few words may be said with advantage on the aesthetic aspects of dress, 
 although it is true that there is no possibility of disputing about matters of 
 taste. There seem to be some few principles, however, which form the true 
 groundwork of the question, which it may be well to discuss. 
 
 In the first place a dress must suggest cleanliness and purity, if we 
 place side by side in the mind's eye the modern nurse or dairymaid in clean 
 print dress and spotless cap and apron and the costermonger's girl bedecked 
 in tawdry finery, there can be no question as to which is most pleasing to the 
 educated eye. No costume can really look weU if it be not kept clean, and 
 directly a dress suggests anything but the most perfect cleanliness its aBsthetic 
 •value becomes nil. 
 
 The working classes in this country dress very largely in the cast-off 
 
534 HYGIENE 
 
 clothing of the class above them, and persons who are too poor to keep a 
 lady's maid are fond of imitating the costumes of those who do, with the 
 result that such costumes are never properly cleaned and brushed ; an opera- 
 tion which the owner, who probably has many duties, has not time to perform. 
 The working classes in this country seldom wear a blouse, as the French do, 
 and the smock frock has been almost completely abandoned, with the result 
 that a large proportion of the labouring classes look habitually filthy. It is 
 absolutely essential from the {esthetic and hygienic point of view that the 
 outer clothes of people who work for their living should be made of washable 
 materials with a smootli surface. Domestic servants very generally follow 
 this rule, but among the working classes at large the painters are almost the 
 only section who habitually wear washable overalls. 
 
 The dressing of the hair should be of a fashion to suggest cleanUuess. 
 Tumbled hair may be ' artistic,' but it suggests dust and a .difficulty of 
 combing which is not quite comfortable for the thoughtful onlooker. Truly 
 artistic clothing must suggest health and comfort. It must not be tight, nor 
 must the folds be so cumbersome as to hamper free movement. It must be 
 suitable for the chmate and season. All attempts to adopt ' classic styles,' 
 i,e, the costume once worn in Athens, which is fifteen degrees south of London,. 
 must end in failure. 
 
 On the question of colours we have little to say except that the dowdy 
 half-tints which were in vogue a few years since, in so much as they 
 suggested fading and shabbiness, seemed to fail in the first law of sestheticism. 
 The colour should certainly vary with the season — cool light colours for 
 the summer and ' warm ' tints for the winter. 
 
 It will probably be useful to give as an appendix to this article a 
 few receipts which will be found serviceable in comiection with clothing. 
 These have been taken from the sixth edition of Cooley's ' Cyclopa?dia of 
 Practical Eeceipts,' edited by E. V. Tuson (London : J, and A, Churchill;. 
 
 Waterproofing. — 1, Moisten the cloth on the wrong side first with a weak solution of 
 isinglass, and, when dry, with an infusion of nut-galls. 
 
 2. Moisten the cloth on the wrong side first with a solution of soap, and, when dry, 
 with a solution of alum. 
 
 3. Eub the wrong side of the cloth with a lump of beeswax (perfectly pure and free 
 from grease) until it presents a light but even white or greyish appearance ; a hot iron is 
 then to be passed over it, and, the cloth being brushed whilst warm, the process is com- 
 plete. AVhen the operation has been skilfully performed a candle may be blown out 
 through the cloth if coarse, and yet a piece of the same, placed across an inverted hat, 
 may have several glassfuls of water poured into the hollow formed by it without any of 
 the liquid passing through. 
 
 Waterproof liquids, for boots, shoes, and leather articles. 
 
 1. India-rubber in fragments, 1 oz. ; boiled oil, 1 pint ; dissolve by heat, carefully 
 applied, then stir in of hot boiled oil 1 pint, and remove the vessel from the fire. 
 
 2. Boiled oil, 1 pint ; beeswax and yellow resin, of each 2 oz. ; melt them together. 
 Dubbing. — Black resin, 2 lb. ; tallow, 1 lb. ; crude cod oil or train oil, 1 gallon ; boil 
 
 to a proper consistence. 
 
 Stains and spots on clothes may be removed with a little clean oil of turpentine or 
 benzol, or with a little fuller's earth or scraped French chalk made into a paste with 
 water and allowed to dry on them, or by a hot tlat-iron and a piece of blotting-paper. 
 
 Fruit and ivine stains on linen commonly yield easily to hot soap-and-water. 
 
 I7ik spots and recent iron mould on washable fabrics may be removed by dropping 
 on the part a little melted tallow from a common candle before washing the articles, or 
 by the application of a little lemon juice or powdered cream of tartar made into a paste 
 with hot water. 
 
 Old ink spots and iron mould will be found to yield almost immediately to a very 
 little powdered oxalic acid, which must be well rubbed upon the spot previously moistened 
 with boiling water and kept hot over a basin filled with the same. 
 
CLOTHING 5Br^ 
 
 Fireproofing. — It is vei-y advisable to treat light, gauzy articles (such as muslin) in 
 some way to prevent them from tlaring up if they come accidentally in contact with a 
 light. This may be attained by steeping the fabric in almost any saline solution. Thus, 
 cotton or linen stuffs, prepared with a solution of borax, phosphate of soda, phosphate of 
 ammonia, alum, or sal-ammoniac, may be placed in contact with ignited bodies without 
 their suffering active combustion or bursting into flame. The salts act by forming a crust 
 of incombustible matter on the surface of the fibres. 
 
 The addition of about 1 oz. of alum or sal-ammoniac to the last water used to rinse 
 a lady's dress, or a set of bed furniture, or a less quantity added to the starch used to 
 stiffen, renders them uninflammable, or at least so little combustible that they will not 
 blaze. 
 
 For fine muslin, tungstatc of soda is found to answer better than any of the above- 
 named salts. ' Muslin steeped in a solution containing 20 per cent, of this salt is perfectly 
 non-inflammable when dry, and the saline film left on the surface is smooth and of a fatty 
 appearance like talc, and therefore does not interfere with the process of ironing, but 
 allows the hot iron to pass smoothly over the surface. The non-fulfilment of this latter 
 condition completely prevents the use of many other salts, such as sulphate or phosphate 
 of ammonia, which are otherwise efficacious in destroying inflammability — for all fabrics 
 which have to be washed and ironed ' (Watts). 
 
 Eefeeence to Plate of Fibkes 
 
 A. Linen (Linen handkerchief). B. Cotton (Sewing cotton). C. Silk (Silkworm 
 cocoon). D. Wool (Woollen shawl). E. Hemp (Eope). F. Coir (Cocoa-nut matting). 
 G. Jute (The raw material). H. Fii,r (Eabbit). 
 
 (a) Low poiuer (about 100 diameters), (b) (c) High power (about 500 diameters). la 
 G, (b) represents a small bundle, (c) a single fibre. 
 
PHYSICAL EDUCATION 
 
 BY 
 
 FEEDEEICK TEEVES, F.E.C.S. 
 
 SLTIGEON TO AXD UECTnBEE ON ANATOMY AT THE LONDON HOSPITAL; JIEMBER OF TIIE 
 BOARD OP EXAMINERS OP THE KOTAL COLLEGE OF SUUGEOXS 
 
INTEODUCTOEY 
 
 Writees are not yet weary of enlarging upon the marvels of civilisation, 
 upon the intellectual development of the human race, upon the triumphs of 
 human ingenuity, and the might and magnificence of human culture. He 
 has, indeed, much to marvel at who measures the gulf which separates the 
 polished citizen of the world from the half-naked and quite savage barbarian. 
 The inventive genius of the modern, the high development of each craft and 
 industry which he has cultivated, the skill of the nineteenth-century artisan, 
 the general intellectual condition of the masses in the great centres of 
 civihsation, are all features of attraction for those who are unceasing in the 
 glorification of the race. The great elements in human progress afford, 
 indeed, proper material for admiration. There is no one but would admit 
 that the advantages of the civilised man over the savage are such as to make 
 reasonable comparisons scarcely possible ; but there follows upon this the 
 question as to whether the so-called blessings of civilisation represent an 
 unmixed good. The intellectual victory has been great, but it has not been 
 effected without cost. We have in our midst the inventor, the man of 
 genius, the handicraftsman, but we have also the weakling, the delicate, the 
 misshapen, and that most modern product of all, the mannikin of the city. 
 This pale, wizened, undersized creature represents no little sacrifice ; he is a 
 product of civilisation, an unintentional manifestation, but a characteristic one. 
 
 If one watches the stream of men, boys, and girls which pours out at 
 the close of day from a great city factory, the question may well be asked, 
 Are these superior to the savage in all things, and are there no points 
 in which the barbarian could claim some advantage over his modern 
 descendant ? 
 
 The savage Norseman who first sailed the northern seas knew Httle of 
 art and less of science, but he had great lungs and a stout heart and mighty 
 muscles and exhaustless strength, and was a stranger — it might be assumed 
 — to many of the aches and pains and petty illnesses which the modern 
 town dweller regards as a natural heritage. 
 
 In the face of a marvellous social, moral, and intellectual development 
 we are apt to lose sight of the fact that man is an animal, that he cannot yet 
 do without a body, and that a strong receptacle for the mind is better than 
 a frail one. 
 
 The higher type of savage was perfect in form, lithe in movement, keen of 
 vision, and strong of arm. He felt in his veins the glow of life, the joy of 
 mere vigour thrilled his muscles, the instincts of mere health dignified his 
 movements. If he pursued physical culture to an exclusive degree, it is 
 possible that his civilised brother may carry intellectual finish to an equal 
 extreme. 
 
 There is evidence to show that an exclusive development of what are 
 quite properly termed the higher faculties of man is not of unmixed advan- 
 tage. Progress is so rapid, and the movements of daily life are so exacting, 
 that there is a tendency to overlook the fact that man cannot live by 
 intellectual bread alone. The young lad is taught to read as soon as he 
 can lisp, and to write as soon as he can grasp a pen. At school he is 
 forced and fostered like a hot-house plant, and when he is old enough to- 
 
5-10 HYGIENE 
 
 take his place in the race in life he at once feels the fever of competition and 
 the strain of incessant endeavour. 
 
 It is, however, hecomiug obvious that one great element of success 
 in hfe is bodily strength ; and that he who has every mental requirement 
 and the finest intellectual finish may find that he still lacks the one thing 
 needed. Sound physical health enables a man to work with vigour and 
 freshness, to pass unharmed through periods of unusual pressure, to with- 
 stand the evils of wori-y, to preserve a clearness and acuteuess of mind when 
 others are worn and fretful and uncertain, and to still press forward when 
 others have fallen in the race. 
 
 He will do well who still retains in the midst of his city hfe some of the 
 quahties of the men of the plain. He will find that muscular strength and 
 good lungs are not without value, even though he be no longer dependent 
 upon the hunter's skill for his daily meal. The attributes of the trapper 
 and the seaman are attributes which cannot be without service, even in 
 the murkiest life in the wilderness of a great city. 
 
 It is noAV more or less clearly recognised that no skill, no learning, no 
 intellectual greatness, can carry with it its fullest influence without a certain 
 element of physical capacity in the individual. 
 
 The unduly diligent student who burns the midnight oil, who cannot 
 tear himself away from his books, who moves in a world in which the only 
 sunshine is that of learning, and the only breeze is that which blows from 
 the erudition of the past, is often a miserable object enough as a human 
 being. His face is wan, his arms are feeble, his eyes are dim, he hves in 
 an atmosphere of little ailments, and he has few pleasures other than the 
 joys of the bookworm. Such a man would make no less progress in the 
 present, and would effect no less influence in the future, if he would devote 
 some leisure to the cultivation of his body. A clear eye, a wiry limb, and a 
 ruddy cheek are not inconsistent with the greatest intellectual development ; 
 while on the other hand there are many poor lads who have been crammed 
 and cultivated until they are mere learned invalids. It may well be asked of 
 their learning, ' What will they do with it ? ' Many a ' city man ' can have 
 but little knowledge of living, however much he may know of ' life.' His 
 hurried hours of work are followed by a period of dulled rest. He lives in the 
 maze caused by the rush of passing events, he knows Httle of the joys of 
 the world as the barbarian knows them, and his journey through life is but 
 at a halting and creaking pace. He remains a partly developed creature 
 who has never attained to the full stature of a man. 
 
 Montaigne well says, in speaking of a man as he should be, ' I would 
 have the disposition of his limbs formed at the same time with his mind. 
 'Tis not a soul, 'tis not a body we are training, but a man, and we must not 
 divide him.' 
 
 In certain directions the importance of simple physical health and strength 
 cannot well be exaggerated. The part these have played in the history of the 
 British race has been magnificent enough. The glories of Enghsh enterprise, 
 the daring and hardihood of the British seaman, the unconquerable pluck of 
 the English soldier, have taken no httle share in forming the greatness of the 
 British nation. The love of sport among the Enghsh, the delight in manly 
 games and outdoor exercises, the contempt for what is efi'eminate and feeble, 
 are outcomes of a vigorous health and a sturdy growth. 
 
 There is no need to modify the fact that the position of Great Britain 
 among European nations is due in no small extent to quahfications which 
 have been the glory of savage peoples. The explorer may have profound 
 knowledge and a preternatural judgment, but they avail but httle if he be 
 
PHYSICAL EDUCATION 541 
 
 not possessed of mere rude health and strength. The main pride of the 
 early navigator was his reckless courage and his sturdy endurance. The 
 greatest commander would have proved a man of straw had he not at his 
 call men who shirked no hardship and who felt no fear. 
 
 It may not be a graceful acknowledgment, but it is none the less true 
 that the power of the English people has depended in no little degree upon 
 those very humble qualities which make ' a good animal.' 
 
 There is an instinct which impels the human being to seek health in 
 muscular exercise and pleasure in physical exertion. The very restlessness 
 of the child is an expression of this. It is often said of a child that he or 
 she is never still. It is an excellent feature. It is as unreasonable to expect 
 a young lad to keep quiet as to expect him not to cough when he has a cold. 
 The infant jumps and kicks and crows ; the child shows its natural 
 promptings by incessant restlessness. The schoolboy, if he be vigorous and 
 healthy, appears to have acquired the art of perpetual movement. The 
 mad rush of a crowd of schoolboys from the schoolroom the moment 
 they are free is characteristic enough and pleasant to witness. The limbs 
 and muscles which have been so long still feel the need of movement as a 
 half suffocated man feels the need of air. The boy who is the first to reach 
 the open air beyond the schoolhouse door has probably not an evil future 
 before him ; he has at least made a good beginning. He, on the other hand, 
 who crawls out last, who feels no irresistible impulse to jump and shout, is 
 in some way abnormal ; he is ill m health or imperfect in construction. 
 He may prove an excellent scholar, but the terrible earnestness of the race 
 of life is not best met by mere scholarship. 
 
 Throughout life there exists in all healthy bodies this natural craving for 
 exercise, and a man may consider that he has reached an unfortunate period 
 in his career when he has ceased to feel that impulse. 
 
 Muscles can grow only by exercise and by the simple expedient of using 
 them. The disused muscle wastes, and becomes fatty and anaemic. Mus- 
 cular tissue occupies nearly every part of the body, from so dehcate a piece 
 of mechanism as the eye to so simple a structure as the biceps humeri. 
 Exercise implies not merely the development of the muscles of the limbs, 
 it implies also the healthy use of the muscle of the heart, of the muscles of 
 respiration, of the muscular tissue of the arteries, and of the muscular ele- 
 ments of all parts capable of movement. Such movement carries with it of 
 necessity an activity in the nervous system, an activity in the secreting 
 organs and in the organs of excretion. 
 
 Movement, indeed, within proper bounds is essential to the full develop- 
 ment and perfect maintenance of the health of the body. The body is a 
 machine with the peculiar attribute that the more it is used, within reason- 
 able limits, the stronger and more capable it becomes. It gathers strength 
 by movement, and that strength is to be gauged, not by mere muscular force, 
 but by the perfect functional condition of every part and of every organ. 
 
 Physical Education involves exercise and movement. We know of no other 
 means of developing any portion of the organism, provided that the supply of 
 food and of air be sufficient. Exercise means growth, functional vigour, and 
 the maintenance of a high standard of organic life. Undue rest imphes decay, 
 feebleness, and a debased standard of functional value. Absolute rest is 
 found only in death. 
 
 Of artificial means of attaining physical perfection there are none. Every 
 structure and tissue must be duly and accurately exercised and kept in 
 proper movement ; and this applies as well to the ciliary muscle of the eye 
 as it does to the great flexors of the leg, as well to the peptic glands of the 
 
542 HYGIENE 
 
 stouiaeli as to the cells of the cortex of the brain. The body is like a busy 
 towii ; so long as there is activity within its walls, and so long as every nook 
 and corner is alive with the best energies of those who dwell therein, things 
 fare well ; but when one section Hags, when inactivity falls upon this quarter 
 or upon that, there comes some retrogression, some halting in a progress 
 which had hitherto been even and energetic. If the intellect is to be culti- 
 vated, the brain must be exercised. He who wishes to acquire the far vision 
 of the seaman must use his eyes like a seaman, and he who would develop 
 the hmiter's keenness of hearing and powers of endurance must lead the 
 hunter's life. . 
 
 To learn how to rightly exercise every part and organ of the body, and 
 how to effect this without undue effort or injurious strain, is to discover the 
 ehxir of life and such a philosopher's stone as will render the short tenure 
 of human life as free from bodily troubles as the art of man can make it. 
 
 It is no longer possible to say, as Herbert Spencer did some twenty years 
 ago, that the inhabitants of this country take an interest in the rearing of the 
 offspring of all creatures except themselves. Civilisation has not yet greatly 
 impaired the unconquerable love of sport and the passion for movement and 
 violent exercise which appear to be the heritage of the British race. There 
 is some evidence to shoAV that, taking averages, we have not diminished 
 either in height or in girth. There is evidence of deterioration among the 
 poorer inhabitants of great cities, but among the more favoured classes it 
 would appear that no change has taken place which indicates a distinct 
 downward tendency. Within recent years there has been a remarkable 
 revival of interest in sports, games, and athletic exercises of all kinds. It 
 was not until 1875 that the English Channel was crossed by a swimmer. So 
 far as it is known, it was not until the year 1877 that a human being had 
 ever leapt from the ground, mthout artificial aid, to the height of 6 feet 
 2 inches. A man can now jump across a gap 23 feet in width, a mile has 
 been run in less than 4^ minutes, and 600 miles have been walked in one 
 week. 
 
 It is quite obvious that the term Physical Education must include the 
 regulation of the functions and movements of the entire body. With such 
 as concern the supply of suitable food and wholesome air, and the observa- 
 tion of what are known as simple hygienic conditions, the present paper has 
 no concern. 
 
 It is necessary here to deal only with that most conspicuous factor in 
 physical culture which concerns the due and proportionate exercise of the 
 muscles of the body. 
 
 In the following article we shall first consider the general effects of 
 exercise, including the subjects of fatigue, overwork, and want of exercise, 
 and secondly the effects of specific exercises. 
 
 THE GENERAL EFFECTS OF EXEECISE 
 
 1. The Effect of Exeecise upon the Development axd 
 PropoPvTions of the Body 
 
 Exercise, as here understood, may be represented by such natural, sys- 
 tematic, and well-regulated exercises as enter into the life of every healthy 
 public schoolboy, together with such special gymnastics which may be con- 
 sidered to be necessary in particular cases. It must be understood that the 
 object of exercise— as here intended — is not to develop athletes, acrobats, and 
 
PHYSICAL EDUCATION 543 
 
 phenomenally strong men, but to encourage and maintain the highest and 
 most equable development of the body. 
 
 The secret of the size and proportions of the future man lies buried in 
 the ovum from which the individual is developed. It may be said, indeed, 
 that there are two proportions possible in every human body — first, that 
 which is congenital, inherited, and predetermined ; and, secondly, such an 
 increase or modification of these proportions as may be effected by proper 
 exercise. 
 
 The child of short and stunted parents will probably also be short and 
 stunted, and may remain so in spite of an elaborate physical training. An 
 infant Bushman transformed suddenly to a cotter's home in Scotland could 
 never be expected to attain the proportions of the young Highlanders with 
 whom his lot had been cast. In estimating the effect of exercise and in 
 speculating upon its possible powers in this direction a constant reference 
 must be made to those inherited factors which are quite beyond control. 
 Exercise cannot make a man a giant, nor can it with any certainty develop 
 a modern Hercules. It can, however, influence the growth and structural 
 perfection of the body in a manner which is definite and to some extent 
 remarkable. 
 
 Exercise increases the size of a muscle, the proportions of its tendon and 
 the power it can command. After undue rest a muscle becomes thin, soft, 
 wasted, and feeble. The stronger the muscles, the finer and denser are the 
 aponeuroses with which they are connected and the stouter are the fascite 
 which hold them in position. Muscles act upon articulations. The duly 
 exercised joint has a good covering of cartilage, powerful ligaments, and 
 well- developed bony parts. The joint which has been long kept at rest has 
 wasted ligaments, a thinned cartilage, and bones of smaller proportions. 
 It becomes, moreover, hypersesthetic from disuse, and the tissues around are 
 found to be flabby and anemic. Within certain somewhat narrow limits 
 the mechanical possibilities of a joint can be much extended by exercise. 
 
 Muscular strength, moreover, influences the size of the bones upon which 
 the muscles act. The skeleton of a feeble individual compares in a very 
 marked manner with the skeleton of a muscular person of the same height 
 and the same age. The bone of the muscular individual is stronger, firmer, 
 and denser ; it is actually larger, and the so-called muscular surfaces and 
 ridges are more conspicuously marked. 
 
 Exercise induces a more vigorous respiration, and u.nder increased 
 breathing efforts the lung capacity is increased and the size of the thorax is 
 augmented. Exercise, moreover, accelerates the blood circulation, and it is 
 needless to point out the effect an increased blood supply has upon the size 
 and development of the tissues concerned. 
 
 1. The Development of the Body. — Before considering the special effects 
 of exercise upon the growth of the body it is necessary to take note of what 
 may be termed the average measurements of the human organism. 
 
 The principal facts with regard to the growth of the body, its weight 
 and height at various periods of life, its comparative proportions in males 
 and females, and other features concerned in Anthropometry, are briefly set 
 forth in the following tables. 
 
 The principal tables are derived from Mr. Charles Eoberts's ' Manual of 
 Anthropometry,' and to this admirable and classical work the reader is referred 
 for more extensive details. Much use has been made also of the Eeport of 
 the Anthropometric Committee of the British Association, 1882-3. This 
 report was drawn up by Mr. Eoberts and Sir E. W. Eawson, nnd has been 
 published as an appendix to Mr. Eoberts's ' Manual.' These two works provide 
 
544 
 
 HYGIENE 
 
 tlie most precise data upon Anthropometry, so far as the Enghsh race is 
 concerned, which we possess. 
 
 It may in the first place be well to tabulate the periods at which the 
 various parts of the skeleton are completed, so far as the facts of osteology 
 guide us. 
 
 The Spine ) 
 
 The Pehas - The 25th year 
 
 The Shoulder Girdle .... J 
 
 The Upper Limb 
 
 The Lower Limb 
 
 The 20th year 
 The Femur the 20th year 
 The Tibia the 22nd year 
 The Fibula the 24th year 
 
 Table I. — SJioiuing the average stature {without shoes) and tJw average weight [incUuling 
 clothes) at all ages of the general population of Great Britain. {All classes. Town 
 and country.) Number of observations on which the averages are founded. Stature : 
 Males, 37,574. Females, 4,616. Weight : Males, 33,043. Females, 4,685. (From th& 
 Eeport of the Anthropometric Committee, 1883.) 
 
 Males 
 
 Peniales 
 
 Age last 
 
 Average 
 
 In- 
 
 Average 
 
 In- 
 
 Age last 
 birthday 
 
 Average 
 
 In- 
 
 Average 
 
 In- 
 
 height, 
 
 crease in 
 
 weight, 
 
 crease in 
 
 height. 
 
 crease in 
 
 weight, 
 
 crease in 
 
 birthday 
 
 inches 
 
 inches 
 
 pounds 
 
 pounds 
 
 inches 
 
 inches 
 
 pounds 
 
 pounds 
 
 Birth 
 
 19-52 
 
 
 7-1 
 
 
 Birth 
 
 19-31 
 
 
 6-9 
 
 _ 
 
 0-1 
 
 27-00 
 
 — 
 
 — . 
 
 — 
 
 0-1 
 
 24-83 
 
 5-52 
 
 — 
 
 — 
 
 1 
 
 33-50 
 
 — 
 
 — 
 
 — 
 
 1 
 
 27-50 
 
 2-67 
 
 20-1 
 
 — 
 
 2 
 
 33-70 
 
 
 32-5 
 
 — 
 
 2 
 
 32-33 
 
 4-83 
 
 25-3 
 
 5-2 
 
 3 
 
 36-82 
 
 
 34-0 
 
 1^5 
 
 3 
 
 36-23 
 
 3-90 
 
 31-6 
 
 6-3 
 
 4 
 
 38-46 
 
 1-64 
 
 37-3 
 
 3-3 
 
 4 
 
 38-26 
 
 2-03 
 
 36-1 
 
 4^5 
 
 5 
 
 41-03 
 
 2-57 
 
 39-9 
 
 2-6 
 
 5 
 
 40-55 
 
 2-29 
 
 39-2 
 
 3^1 
 
 6 
 
 44-00 
 
 2-97 
 
 44-4 
 
 4-5 
 
 6 
 
 42-88 
 
 2-33 
 
 41-7 
 
 2^5 
 
 7 
 
 45-97 
 
 1-97 
 
 49-7 
 
 5-3 
 
 7 
 
 44-45 
 
 1-57 
 
 47-5 
 
 6^8 
 
 8 
 
 47-05 
 
 1-08 
 
 54-9 
 
 5^2 
 
 8 
 
 46-60 
 
 2-15 
 
 52-1 
 
 4-6 
 
 9 
 
 49-70 
 
 2-65 
 
 60-4 
 
 5^5 
 
 9 
 
 48-73 
 
 2-13 
 
 55-5 
 
 3^4 
 
 10 
 
 51-84 
 
 2-14 
 
 67-5 
 
 7-1 
 
 10 
 
 51-05 
 
 2-32 
 
 62-0 
 
 6^5 
 
 11 
 
 53-50 
 
 1-66 
 
 72-0 
 
 4-5 
 
 11 
 
 53-10 
 
 2-05 
 
 68-1 
 
 6-1 
 
 12 
 
 54-99 
 
 1-49 
 
 76-7 
 
 4^7 
 
 12 
 
 55-66 
 
 2-56 
 
 76-4 
 
 8-3 
 
 13 
 
 56-91 
 
 1-92 
 
 82-6 
 
 5-9 
 
 13 
 
 57-77 
 
 2-11 
 
 87-2 
 
 10-8 
 
 14 
 
 59-33 
 
 2-42 
 
 92-0 
 
 9-4 
 
 14 
 
 59-80 
 
 2-03 
 
 96-7 
 
 9-5 
 
 15 
 
 62-24 
 
 2 91 
 
 102-7 
 
 10-7 
 
 15 
 
 60-93 
 
 1-13 
 
 106-3 
 
 9-6 
 
 16 
 
 64-31 
 
 2-07 
 
 119-0 
 
 16^3 
 
 16 
 
 61-75 
 
 •82 
 
 113-1 
 
 6-8 
 
 17 
 
 66-24 
 
 1-93 
 
 130-9 
 
 11-9 
 
 17 
 
 62^52 
 
 •77 
 
 115-5 
 
 2-4 
 
 18 
 
 66-96 
 
 ■72 
 
 137-4 
 
 6-5 
 
 18 
 
 62-44 
 
 — 
 
 12M 
 
 5-6 
 
 19 
 
 67-29 
 
 -33 
 
 139-6 
 
 2-2 
 
 19 
 
 62-75 
 
 •23 
 
 123^8 
 
 2-7 
 
 20 
 
 67-52 
 
 •23 
 
 143-3 
 
 3-7 
 
 20 
 
 62-98 
 
 •23 
 
 123-4 
 
 •6 
 
 21 
 
 67-63 
 
 •11 
 
 145-2 
 
 1-9 
 
 21 
 
 63-03 
 
 •05 
 
 121-8 
 
 — 
 
 22 
 
 67-68 
 
 •05 
 
 146-9 
 
 1-7 
 
 22 
 
 62-87 
 
 — . 
 
 123-4 
 
 — 
 
 23 
 
 67-48 
 
 — 
 
 147-8 
 
 •9 
 
 23 
 
 63-01 
 
 — 
 
 124-1 
 
 •7 
 
 24 
 
 67-73 
 
 -05 
 
 148-0 
 
 •2 
 
 24 
 
 62-70 
 
 — 
 
 120-8 
 
 — 
 
 25-30 
 
 67-80 
 
 •07 
 
 152-3 
 
 4^3 
 
 25-30 
 
 62-02 
 
 — 
 
 120-0 
 
 — 
 
 30-35 
 
 68-00 
 
 •20 
 
 159-8 
 
 7^5 
 
 30-35 
 
 \ 
 
 — 
 
 120-8 
 
 — 
 
 35-40 
 
 68-00 
 
 
 
 164-3 
 
 4-5 
 
 35-40 
 
 
 — 
 
 120-8 
 
 — 
 
 40-50 
 50-60 
 
 67-96 
 67-92 
 
 — 
 
 163-3 
 166-1 
 
 1-8 
 
 40-50 
 50-60 
 
 - 61-15 
 
 — 
 
 118-0 
 1040 
 
 — 
 
 60-70 
 
 67-41 
 
 — 
 
 158-1 
 
 2-0 
 
 60-70 
 
 
 — 
 
 — 
 
 — 
 
 70 
 
 69-22 
 
 1^22 
 
 182^1 
 
 — 
 
 70 
 
 1 
 
 
 106-0 
 
 i 
 
 The following comments upon the series of tables of which the above is 
 an abstract are furnished by the Anthropometric Committee : — 
 
 1. Growth is most rapid during the first five years of life. 
 
 2. From birth to the age of five years the rate of growth is the same in 
 both sexes, girls being a little shorter in stature and lighter in weight than boys. 
 
PHYSICAL EDUCATION 
 
 045 
 
 8. From five to ten years boys grow a little more rapidly than girls, the 
 difference being apparently due to a check in the growth of girls at these ages. 
 
 4. From ten to fifteen years girls grow more rapidly than boys, and at the 
 ages of eleven and a half to fourteen and a half are actually taller, and from 
 twelve and a half to fifteen and a half years actually heavier than boys. 
 This difference appears to be due to a check in the growth of boys as well as 
 an acceleration in the growth of girls incident on the accession of puberty. 
 
 5. From fifteen to twenty years boys again take the lead, and grow at 
 first rapidly, then gradually slower, and complete their growth at about 
 twenty-three years. After fifteen, girls grow very slowly, and attain their 
 full stature about the twentieth year. 
 
 6. The tables show a slow but steady increase in stature up to the fiftieth 
 year, and a more rapid increase in weight up to the sixtieth year in males, 
 but the statistics of females are too few after the age of twenty-three to deter- 
 mine the stature and weight of that sex at the more advanced periods of life. 
 
 ' It is probably due to the greater or less development of the body at the 
 time of the accession of puberty,' writes Mr. Eoberts, ' that the final difference 
 in the height of individuals is chiefly to be attributed ; hence the influences 
 which promote or retard growth at this period are most deserving of study. 
 In boys puberty occurs later, and is less regular and decided, than in girls. 
 The transition from boyhood to manhood extends over a period of three to 
 four years, and is accompanied by increased physical development of the 
 body ; but girls develop into women in a few months, and with the complete 
 establishment of puberty, growth in height is much diminished, and often 
 ceases altogether.' 
 
 As a further contribution to the subject of the growth of boys the follow- 
 ing tables compiled by Maclaren may be added : — 
 
 Table II. — Showing the State of Growth and Development between the ages of 10 and 18 
 years, being the averages of the actual measurements of 100 boys at each age. (Maclan^en} 
 
 Age 
 
 Height 
 
 Weight 
 
 G-irth of chest 
 
 Forearm 
 
 Upper arm 
 
 Tears 
 
 Pt. in. 
 
 St. lb. 
 
 Inches 
 
 Inches 
 
 Inches 
 
 10 
 
 4 5i 
 
 4 9 
 
 251 
 
 7i 
 
 7| 
 
 11 
 
 4 7 
 
 5 
 
 26i 
 
 7i 
 
 8 
 
 12 
 
 4 8f 
 
 5 8i 
 
 27i 
 
 8 
 
 8i 
 
 13 
 
 4 10| 
 
 6 Oi 
 
 28| 
 
 ®t 
 
 l^ 
 
 14 
 
 5 Of 
 
 6 9 
 
 29 i 
 
 8| 
 
 9 
 
 15 
 
 5 3 
 
 7 5i 
 
 30| 
 
 9 
 
 9* 
 
 16 
 
 5 5 
 
 8 4 
 
 32i 
 
 9* 
 
 m 
 
 17 
 
 5 7 
 
 9 2i 
 
 34i 
 
 10 
 
 11 
 
 18 
 
 5 8 
 
 9 11 
 
 35i 
 
 lOJ 
 
 Hi 
 
 Table III.— Abstract of preceding Table showing average Annual Bate of Growth and 
 Development from year to year. {Maclaren) 
 
 - 
 
 Height 
 
 Weight 
 
 Girth of 
 chest 
 
 Forearm 
 
 Upper arm 
 
 
 
 Inches 
 
 Lb. 
 
 Inches 
 
 Inches 
 
 Inches 
 
 From 10 years 
 
 to 11 years . 
 
 ^ 
 
 5 
 
 
 i 
 
 i 
 
 4 
 
 „ 11 
 
 12 „ . 
 
 
 2 
 
 8i 
 
 ■^4 
 
 i 
 
 4 
 
 „ 12 
 
 13 „ 
 
 
 If 
 
 6 
 
 
 i 
 
 J 
 
 „ 13 
 
 14 „ 
 
 
 n 
 
 8| 
 
 
 i 
 
 4 
 
 h 
 
 „ 14 
 
 15 „ . 
 
 
 H 
 
 lOi 
 
 -■■l 
 
 * 
 
 ■^ 
 
 „ 15 
 
 16 „ . 
 
 
 2 
 
 13 
 
 1| 
 
 1 
 
 * 
 
 „ 16 
 
 17 „ 
 
 
 2 
 
 12 
 
 1 3 
 ■"■4 
 
 4; 
 
 „ 17 
 
 18 „ 
 
 
 1 
 
 8i 
 
 
 4 
 
 4 
 
 VOL. I. 
 
 N N 
 
546 
 
 HYGIENE 
 
 Some children appear to grow by fits and starts. Children who have re- 
 mained for many successive years under the average height may suddenly 
 shoot up and attain more than the normal stature when they reach adult age. 
 (See in connection with this matter Case 4, Table VII.) 
 
 The extremes in development are well illustrated by the following obser- 
 vations made by ]\Iaclaren. They give the result of the examination of 100 
 University men (fi-eshmen) who Avere not especially selected. 
 
 
 The greatest 
 
 The smallest 
 
 
 developmeuts 
 
 (leveloiimeuts 
 
 Height 
 
 . 6 ft. 6 in. 
 
 5 ft. 2 in. 
 
 Weight 
 
 . 12 St. 2 lb. 
 
 7 St. 
 
 Chest girth 
 
 . 39 in. 
 
 27i in. 
 
 Forearm . 
 
 . 113 in. 
 
 8^ in. 
 
 Upper arm 
 
 . 12-| in. 
 
 8| in. 
 
 The effect of occupation and social and physical condition upon develop- 
 ment is well demonstrated by the statistics prepared by Mr. Roberts and the 
 Anthropometric Committee. 
 
 The following tables are derived (in abstract) from the Report of the 
 Committee : — 
 
 Table IV. — Relative Height of Boys at the age of 11 to 12 ijears under different 
 social and physical conditions of life. 
 
 Average height 
 Public schools (country) ....... 54"98 inches 
 
 Middle-class schools ; 
 
 Upper (towns) ....... 53'85 „ 
 
 Lower (towns) ....... .53-70 ,, 
 
 Elementary schools : 
 
 Agricultural labourers ...... 53-01 ,, 
 
 Artisans (town) ....... 52-()0 ,, 
 
 Factory hands (country) 52-17 ,, 
 
 Factory hands (towns) ...... 51-56 „ 
 
 Military asylums ....... 51-20 ,, 
 
 Industrial schools 50-02 „ 
 
 T.U3LE V. — Relative Height of Adults of the ages from 25 to 30 years under different 
 social and i>hysical conditions of life. 
 
 Upper classes, professional classes 
 
 Commercial classes, clerks, shopkeepers, &c. . 
 Agricultural labourers, miners, sailors, Ac. . 
 Artisan classes (towns) ...... 
 
 Factory hands, workers at sedentary trades — e.g. tailors 
 
 Average heifrht 
 ()y-14 inches 
 07-95 „ 
 07-51 „ 
 00-61 „ 
 65-92 „ 
 
 The question of the relation of weight to height will be found considered 
 in Table I. 
 
 Table VI. gives the average chest-girth in males at different periods of 
 life (see also Tables II. and III.). The chest-girth in males shows an increase 
 at a rate similar to that of the weight up to the age of fifty years, but it 
 appears to have no definite relation to stature. 
 
 Table VI.- 
 
 Age next 
 birthday 
 
 10 . 
 
 11 . 
 
 12 . 
 
 13 . 
 
 14 . 
 
 15 . 
 
 -Average Chest-girtli {empty) in inclies in Males of all classes at different ages 
 [licport of Anthropometric Committee). 
 
 Chest girth 
 in inches 
 
 Age next 
 birtliday 
 
 . 2610 
 
 16 . . . 
 
 . 26-58 
 
 17 . . . 
 
 . 27-20 
 
 18 . . . 
 
 . 28-03 
 
 19 . . . 
 
 . 28-46 
 
 20 . . . 
 
 . 29-74 
 
 21 . . . 
 
 Chest girth 
 
 Age next 
 
 Chest girth 
 
 in inches 
 
 birthday 
 
 in inches 
 
 31-53 
 
 22 . 
 
 . 35-33 
 
 33-64 
 
 23 . 
 
 . 35-62 
 
 34-19 
 
 24 . 
 
 . 35-82 
 
 34-49 
 
 25-29 . 
 
 . .36-18 
 
 34-98 
 
 30-35 . 
 
 . 37-08 
 
 35-25 
 
 36-50 . 
 
 . 37-58 
 
PHYSICAL EDUCATION 
 
 547 
 
 The effect of systematised exercise upon the growth and development of 
 hoys and men may now be considered. In the Keport of the Anthropometric 
 Committee the measurements of eighty-nine professional and amateur athletes 
 are given with the following results, ' Their average stature exceeds that of 
 the general population from which they are drawn by O'GB inch, while 
 their average weight falls short of that standard by 14'5 lb. The ratio of 
 weight to stature is in the athletes 2-100 lb. and in the general population 
 2*323 lb. for each inch of stature. Thus a trained athlete; whose stature is 
 5 feet 7 inches should weigh 10 stone, while an untrained man of the same 
 height should weigh 11 stone.' 
 
 Table VII. — To show the Effects of Systematised Exercise 2ipo7i growth and develo'imient 
 
 (Maclarcn). 
 
 - 
 
 Measurements, &c. 
 
 Increase 
 
 Reiuiarks 
 
 Case Date 
 
 03 
 
 Height 
 
 Weight 
 
 1 
 
 iH 
 
 a a 
 
 4^ 
 
 +3 
 
 bo 
 
 1 
 
 ts 
 
 la 
 
 pa 
 
 
 h 
 
 
 
 s 
 
 In. 
 
 — i 
 
 In. 
 
 a 
 
 ^ 
 
 
 
 S s 
 
 
 
 
 
 Ft. in. 
 
 St. lb. 
 
 In. 
 
 In. 
 
 Lb. 
 
 In. 
 
 In. 
 
 In. 
 
 
 1 
 
 1861 June 
 
 10 
 
 4 6| 
 
 4 10 
 
 26 
 
 n 
 
 n 
 
 
 
 
 
 
 
 
 1862 Sept. 
 
 11 
 
 4 9| 
 
 5 5 
 
 281 
 
 H 
 
 Si 
 
 2| 
 
 9 
 
 21 
 
 1^ 
 
 1 
 
 Height above average. 
 
 
 1863 Sept. 
 
 12 
 
 4 lOa 
 
 6 
 
 301 
 
 H 
 
 8^ 
 
 li 
 
 9 
 
 2 
 
 
 1 
 
 Other measurements, 
 
 
 1864 June 
 
 13 
 
 5 2i 
 
 7 2 
 
 321 
 
 n 
 
 9|- 
 
 H 
 
 16 
 
 2 
 
 1 
 
 1 
 
 average. 
 
 
 1865 May 
 
 14 
 
 5 5i 
 
 8 3 
 
 351 
 
 4 
 
 101 
 
 3f 
 
 15 
 
 3 
 
 
 i 
 
 Prom commencement, 
 
 
 1866 May 
 
 15 
 
 5 9 
 
 10 2 
 
 S7i 
 
 11 
 
 12 
 
 H 
 
 27 
 
 2 
 
 11 
 
 It 
 
 growth rapid and siis- 
 
 
 1867 Sep't. 
 
 16 
 
 5 9i 
 
 10 13 
 
 381 
 
 11^ 
 
 12 1 
 
 1 
 
 11 
 
 1 
 
 i 
 
 f 
 
 tained, with regular | 
 
 
 1868 Sept. 
 
 17 
 
 5 10| 
 
 11 2 
 
 391 llf 
 
 13a 
 
 11 
 
 3 
 
 1 
 
 i 
 
 1 
 
 and uniform develop- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ment. 
 
 
 
 
 Total increase . 
 
 16 
 
 90 131 
 
 H 
 
 H 
 
 
 2 
 
 1860 Jan. 
 
 12 
 
 4 1| 
 
 3 13 ; 23i 
 
 6^ 
 
 6 
 
 
 
 
 
 
 Height and all other 
 
 
 1860 July 
 
 12 
 
 -4 3| 
 
 4 1 24 
 
 7 
 
 6| 
 
 H 
 
 1 
 
 i 
 
 i 
 
 t 
 
 measurements greatly 
 
 
 1860 Dec. 
 
 13 
 
 4 4i 
 
 4 1 
 
 241 
 
 7 
 
 7 
 
 1 
 
 1 
 
 2 
 
 
 i 
 
 fteZow average. Whole 
 
 
 1861 Dec. 
 
 14 
 
 4 4i 
 
 4 7 
 
 25 
 
 H 
 
 7i 
 
 
 6 
 
 
 1 
 
 4 
 
 frame stunted and 
 
 
 1862 July 
 
 14 
 
 4 5| 
 
 4 8 
 
 26 
 
 n 
 
 n 
 
 2 
 
 1 
 
 i 
 
 i 
 
 i 
 
 dwarfish. Advance- 
 
 
 1863 Mar. 
 
 15 
 
 4 7i 
 
 4 12 
 
 261 
 
 H 
 
 7f 
 
 n 
 
 4 
 
 i 
 
 8" 
 
 g- 
 
 ment at first slight 
 
 
 1864 July 
 
 16 
 
 4 llA 
 
 6 6 
 
 201 
 
 4 
 
 8i 
 
 4 
 
 22 
 
 3 
 
 1 
 
 11 
 
 and very in-egolar. 
 
 
 
 
 
 
 
 
 
 
 afterwurils rapid and 
 
 
 
 
 
 
 
 
 
 
 comparatively regular. 
 
 
 
 
 Total increase . 
 
 9| 
 
 35 
 
 6 
 
 21 
 
 2| 
 
 
 3 
 
 1859 Dec. 
 
 14 
 
 4 5 
 
 6 1 i 261 
 
 8 1 7i 
 
 
 
 
 
 
 Height greatly below 
 
 
 1860 Sept. 
 
 14 
 
 5 2 
 
 6 4 
 
 29 
 
 9 
 
 9^ 
 
 11 
 
 3 
 
 ^ 
 
 1 
 
 15 
 
 average ; other mea- 
 
 
 1861 July 
 
 15 
 
 5 4i 
 
 7 7 
 
 30 
 
 9 
 
 H 
 
 2| 
 
 17 
 
 1 
 
 
 
 
 
 surements also consi- 
 
 
 1862 Sept. 
 
 15 
 
 5 7| 
 
 8 12 
 
 341 
 
 10 
 
 IH 
 
 
 19 
 
 H 
 
 1 
 
 H 
 
 derably below ave- 
 
 
 
 
 
 
 
 
 
 
 rage. Instant and 
 
 
 
 
 
 
 
 
 — 
 
 
 
 — 
 
 extreme acceleration 
 
 
 
 
 Total increase . 
 
 161 
 
 39 
 
 8 
 
 2 
 
 31 
 
 of growth with mode- 
 rate increase in deve- 
 
 
 
 
 
 
 
 
 
 lopment. 
 
 4 
 
 1859 Oct. 
 
 19 
 
 5 2| 
 
 8 
 
 301 
 
 9 
 
 9i 
 
 
 
 
 
 
 
 1859 Dec. 
 
 — 
 
 5 Si 
 5 3f 
 
 8 1 
 8 1 
 
 33 
 33 
 
 91 
 
 101 
 101 
 
 t 
 
 1 
 
 21 
 
 1 
 
 1 
 
 Well proportioned. A 
 remai-kable feature 
 
 
 1860 Jan. 
 
 20 
 
 
 
 
 
 
 ° 
 
 
 
 lost 
 
 
 is the renewal and 
 
 
 — — 
 
 — 
 
 5 4i 
 
 8 1 
 
 331 
 
 H 
 
 101 
 
 1 
 
 
 
 1 
 
 
 
 
 steady continuation 
 
 
 — June 
 
 — 
 
 5 4| 
 
 8 3 
 
 34 
 
 4 
 
 101 
 
 1 
 
 2 
 
 1 
 
 
 
 
 
 of the upward growth 
 
 
 — — 
 
 — 
 
 5 4f 
 
 8 5 
 
 341 
 
 91 
 
 10* 
 
 
 2 
 
 i 
 
 1 
 
 i 
 
 which had been pre- 
 
 
 
 
 
 
 
 
 
 2_ 
 
 maturely arrested. 
 
 
 
 
 Total increase . 
 
 2 
 
 5 
 
 n 
 
 1 
 
 1 
 
 
 5 
 
 1859 Oct. 
 
 17 
 
 6 
 
 9 4 
 
 301 8| 
 
 91 
 
 
 
 
 
 
 Of delicate frame : 
 
 
 1860 Jan. 
 
 17 
 
 6 
 
 9 9 
 
 321 91 
 
 10 
 
 
 5 
 
 2 
 
 1 
 
 3 
 
 chest fiat and narrow, 
 
 
 1860 June 
 
 18 
 
 6 01 
 
 9 111 
 
 34 9a 
 
 101 
 
 1 
 
 21 
 
 11 
 
 £ 
 
 1 
 
 with sternum much 
 
 
 1860 June 
 
 18 
 
 6 Oi 
 
 9 13 
 
 341 9| 
 
 lOi 
 
 a 
 
 *^2 
 
 ■J 
 
 — 
 
 4 
 4 
 
 depressed. 
 
 
 
 
 Total increase . 
 
 i 
 
 9 
 
 4 
 
 1 
 
 11 
 
 
 
 
 
 
 
 
 \ 
 
 
 N N 2 
 
648 
 
 HYGIENE 
 
 This question of the effect of systematic exercise upon development has 
 been fully dealt with hy Mv. Maclaren. 
 
 His tables dealing with the subject are of great value, and should be con- 
 sulted by all those who are interested in the matter. In the appended tables 
 a selection from these statistics is given. The normal increase in height 
 and weight, as given in Table I., must be taken into consideration. 
 
 Table VIII. — Measurements of twelve Non-commissioned Officers {selected to be qualified 
 as Military Gymnastic Instructors after eight months' training. (Maclareii.) 
 
 Increase noted at end of period 
 
 Age 
 
 Hei 
 
 1 
 jht 1 Weight 
 
 G irth of chest 
 
 Forearm 
 
 Upper arm | 
 
 Tears 
 
 lE 
 
 Lb. 
 
 In. 
 
 In. 
 
 In. 
 
 19 
 
 
 13 
 
 4:V 
 
 1 
 
 ^ 
 
 21 
 
 i 
 
 10 
 
 H 
 
 1 
 
 H 
 
 23 
 
 i 
 1 
 
 ■ 
 
 9 
 
 3i 
 
 1 
 
 H 
 
 23 
 
 9 
 
 u 
 
 H 
 
 1 
 
 23 
 
 10 
 
 1 
 
 
 1 
 
 23 
 
 J 
 
 ^ 9 
 
 2 
 
 s 
 
 1 
 
 23 
 
 J 
 
 5 
 
 2i 
 
 i 
 
 1 
 
 24 
 
 i 
 
 i 12 
 
 5 
 
 1 
 
 li 
 
 26 
 
 
 1 6i 
 
 3 
 
 i 
 
 4 
 
 li 
 
 26f 
 
 
 \ 9 
 
 1 
 
 
 
 1 
 
 28 
 
 . 
 
 ^ 13 
 
 3 
 
 H 
 
 1^ 
 
 28 
 
 i 
 
 \ 16 
 
 3 
 
 1^ 
 
 1 
 
 In an examination of Tables VII. and VIII. the increase in weight under 
 systematised exercise, after allowing for normal increase, is noteworthy. 
 
 In the matter of increase in growth Case 4, Table VII., is interesting 
 as showing the renewal of growth after premature arrest, the young man 
 growing 2 inches after nineteen. Mr. Maclaren gives several other instances 
 of this sudden growth after premature arrest. In Table VII. the increase 
 in height of the older men in the list is of interest. In the majority it may 
 be due to a greater erectness of the figure, to the lessening, therefore, of some 
 of the curvature of the spine, and perhaps to some increase in the interverte- 
 bral substances. 
 
 In the case of the soldiers in Table VIII. the question of the improvement 
 of the carriage can scarcely come into consideration, and the increase in 
 height from ^th to |ths of an inch in the last four men must be ascribed to 
 changes in the tissues. In Case 3, Table VII., the immediate effect of system- 
 atised exercise is apparently shown by a remarkable increase in height of no 
 less than 11 mches in a period of nine months. 
 
 A further point in these tables must be noticed, and that is the remark- 
 able increase in the circumference of the chest, which, it would appear, may 
 be obtained by systematic exercise. 
 
 An increase of 3 to 4 inches in the girth of the thorax may no doubt 
 be in great part ascribed to muscular development in the pectoral and sca- 
 pular regions. It involves, however, an increased respiratory power, and a 
 greater breathing capacity. 
 
 In a country where lung diseases are so common as they are in England, 
 it is difficult to speak too strongly of the importance of obtaining a full 
 development of the chest. 
 
 Physicians recognise the part played by a narrow thorax and a feeble 
 breathing power in aiding the evolution of chronic lung disease and in pro- 
 moting the progress of such processes as are acute. 
 
PHYSICAL EDUCATION 549 
 
 Considering the definite and apparently assured results of physical training 
 in this direction, it appears culpable to allow a child to grow up surrounded 
 by the undoubted dangers which attend the possession of a constricted chest. 
 
 It will be observed from the above tables that a great increase in the 
 circumference of the chest can take place as an almost solitary feature of 
 development. Mr. Maclaren gives the case of a lad of nineteen whose heiglit 
 was not increased by systematic exercise, but who increased the girth of his 
 •chest by 4^ inches in nine months. 
 
 It is well also to note that an improvement in the measurements of the 
 chest can be effected many years after the period of youth is passed. Thus 
 Maclaren cites the case of a gentleman aged thirty-five who at the end of two 
 months' exercise at the Oxford Gymnasium had increased the circumference 
 of his thorax by no less than 4^ inches. His height was diminished by an 
 eighth of an inch, due probably to an increase in the curvature of the thoracic 
 part of the spine. 
 
 In considering the general question of increase in chest girth care must 
 be taken not to ascribe this increase — as some appear inclined to do — entirely 
 to an increase in the capacity of the thoracic cavity. This is probably in all 
 cases of much less effect than muscular development. Those who practise 
 •excessively with gymnastic apparatus acquire a peculiar conformation of the 
 chest, the main factor in which is certainly not an increase in the capacity of 
 the thorax. 
 
 2. The Proportions of the Body. — A proper physical training does some- 
 thing more than merely increase the size of the limbs and possibly the height 
 of the body. It tends to render all parts of the body symmetrical and more 
 perfectly proportioned. 
 
 A well-proportioned body has a grace which is independent of mere size, 
 height, and strength. It is in women especially that the great lack of a per- 
 fect proportion is so often conspicuous. In one the hips are out of propor- 
 tion to the shoulders ; in another the width of the chest is totally out of 
 •keeping with the height of the body ; in a third the length of the upper 
 limbs is not in proportion to the dimensions of the trunk. 
 
 Those who have taken properly arranged exercise from their earliest 
 youth may still need many graces, but they will probably possess the peculiar 
 grace which belongs to a symmetrical body. 
 
 Of all animals man is the most subject to variations in proportion and 
 in symmetry. It is certain that in some children the body develops unevenly : 
 one side appears to be larger than the other ; one limb may be longer than 
 its fellow ; one side of the thorax may be of greater circumference than the 
 other. Such deviations — which in no sense constitute deformity — a well- 
 directed system of physical training may correct. 
 
 It is common to meet a long, lanky lad with spider-like arms and legs, 
 a meagre neck, and a narrow chest. It is probably said that he has ' out- 
 grown his strength.' In reality his growth in height has been out of pro- 
 portion to his growth in muscular power. With proper training such a lad 
 ceases to be lanky ; he becomes merely tall, his chest fills out, his arms 
 acquire a greater girth, his neck becomes sinewy, and the ' scarecrow ' of the 
 schoolroom becomes possibly a lithe, well-proportioned youth. 
 
 Another lad may be squat and ' stumpy ' and heavy-looking. He has a 
 big head and a wide chest and limbs which appear to be ridiculously out of 
 proportion to his burly trunk. He begins to pursue every available form of 
 exercise and outdoor recreation, and in a few years he has sprung up. His 
 wide chest has stood him in good stead, and his limbs are now no longer out 
 of keeping with his body. 
 
550 HYGIENE 
 
 The following account of tlie normal proportions of the body is founded^ 
 upon that given by Mr. Roberts in his ' Manual of Anthropometry.' 
 
 The Head. — Of all parts of the body, the head varies least in its propor- 
 tions during growth. In the average adult it is considered to form the seventh 
 part of the whole height. From birth to the period of full development the 
 head only doubles its height, while the whole body elongates three or four 
 times its original dimensions. The most active growth of the head is during 
 the first two years of life. The lower parts of the face grow at a greater rate 
 than the upper, and all the horizontal measurements of the head develop less 
 than those of height. 
 
 TJie Trunk. — The height of the neck increases irregularly. The most 
 rapid growth is at puberty. The neck ultimately attains to double its original 
 dimensions. The other parts of the body increase with greater energy, and 
 growth is greater the further the parts are situated from the summit of the 
 head. Thus, while the measurements of the head and neck are only doubled, 
 those of the trunk are tripled, and those of the lower extremities are more 
 than quadrupled. The transverse diameters of the trunk increase nearly in 
 the same ratio as the height. They triple from birth to the period of full 
 development. At the age of six or seven, this diameter is already doubled. 
 The antero-posterior diameter of the thorax increases less rapidly and is not 
 doubled until about puberty. 
 
 At the time of birth, when the child is about the sixth of the height it 
 will ultimately attain to, the point which di\-ides the total height into two- 
 equal parts is a little above the navel ; at two years of age it is at the navel ; 
 at three years, when the child has attained half its total height, the central 
 point is on a line with the upper borders of the iliac bones ; at ten years of 
 age, w4ien the child has attained three-fourths of its total height, the central 
 point is on a line with the trochanters ; at thirteen years it is at the pubes, 
 and in the adult man it is nearly half an inch lower. In the adult woman 
 the central point is a little above the pubes. 
 
 The Upper Limbs. — The space covered by the arms extended horizontally 
 is equal to the total height of the body, from birth to puberty. 
 
 In the adult man the ratio of the height to the measurement of the ex- 
 tended arms is as 1 to 1-045 ; and in the adult woman as 1 to I'OIS. The 
 length of the arm — excluding the hand — is doubled at the age between four 
 and five years, tripled between thirteen and fourteen, and quadrupled at the 
 period of full development. The hand develops less rapidly. Afterthe age 
 of seven or eight the length of the hand has the ratio to the total height of 
 one to nine. This apphes to adults both male and female. 
 
 The Lower Limbs. — The lower extremities in adults are five times the 
 length they were at birth. They double their length before the third year, 
 and at twelve they are four times their original length. The length of the 
 thigh varies considerably and has much to do with the differences in the total 
 height of individuals. The foot at all ages of life and in both sexes forms 
 from the 0"15 to 0"1G of the total height of the mdividual. It is only about 
 the age of ten that the length of the foot is equal to the height of the head. 
 Before that period the head is the longer, and after it the shorter. 
 
 The perfect Female Form. — The relative proportions of a perfect female 
 form as deduced by modern sculptors from Greek statues have been given as 
 follows. Her height will be five feet five inches. With the arms extended 
 the measurement from finger-tip to finger-tip should be equal to her own 
 height. The hand should be i\,th of this, the foot -jth, and the chest diameter 
 -!th. From . her perineum to the ground she should measure just what she 
 measures from the perineum to the top of the head. The knee should be 
 midway between the perineum and the heel. 
 
PHYSICAL EDUCATION 551 
 
 The distance from the elbow to the middle finger should be the same as 
 from the elbow to the middle of the chest. The head should be about the 
 length of the foot. A woman of this height should measure 24 inches about 
 the waist, 34 inches around the chest if measured under the arms, and 43 if 
 measured over them. The upper arm should measure 13 inches and the 
 wrist 6. The circumference of the thigh should be 25 inches, of the calf of 
 the leg 14^ inches, and of the ankle 8 inches. 
 
 In determining the rate of growth and development of the body the 
 following system of measurements, advised by Mr. Maclaren and given in his 
 well-known work, may be followed out : — 
 
 System of Measurements 
 
 Heiqht (without boots).— The position of attention, the heels together, the knees 
 braced back, the chin raised, the head held steady, the shoulders square to the front, the 
 heels, hips, shoulders, and head touching the pillar of the standard. 
 
 N.B. — This measurement, when repeated, should always be taken at the same time of 
 the day, and after the same amount of bodily exertion. 
 
 Weight. — In working costume, i.e. in light shoes, flannel trousers, flannel shirt or 
 jersey. 
 
 N.B. — This measurement when repeated should always be taken at the same time 
 of the day, and with reference to any circumstance which would affect its accuracy. 
 
 Chest. — Over the jersey or naked breast. The position of attention, but with the anns 
 horizontally extended, the palms of the hands held upwards and open, the finger straight. 
 The tape should be passed around the chest in the line of the nipple. 
 
 N.B. — Care must be taken that the chest is not inflated beyond its usual expansion 
 during ordinary breathing. Where a single measurement is taken the above hne is the 
 best, as gauging approximately at once the muscular and respiratory capacity ; but when 
 the latter quality is of primary importance (as in rowing) a second measurement should 
 be taken lower down the chest, the tape being passed over the ninth rib. 
 
 In measuring recruits in the British army, the man stands erect, with the arms 
 hanging loosely by the side. The lower edge of the tape should touch the nipple. The 
 man is required to count ten slowly during the operation, to prevent him from keeping 
 his lungs over -inflated. 
 
 Forearm (skin measurement). — The arm extended as in the preceding measurement, 
 but with the hand tightly closed, the tape to be passed around the thickest part of the 
 arm, and its girth at that point reckoned. 
 
 N.B. — With men who have taken little exercise this line will always be found near the 
 elbow joint, but as the limb becomes developed, and the numerous muscles of the forearm 
 acquire bulk and power from exercise, the greatest girth will be found from 2 to 3 inches 
 below it. Unless this circumstance be kept in view the actual increase will not be per- 
 ceived. 
 
 Upper arm (skin measurement). — The hand closed, the arm bent at the elbow, and 
 the hand brought down towards the shoulder. This should be slowly and gradually done, 
 bending the joints of the fingers, clenching the fist, and bringing the forearm down upon 
 the upper arm, the tape to be passed in a straight line around the thickest part of the 
 arm. 
 
 N.B. — When the whole arm is fully developed, the difference in size between the fore 
 and upper arm in an adult of medium stature will be about 2 inches, and it will almost 
 invariably be found that when the upper arm is feeble the upper region of the chest will 
 be feeble also. With a chest of 40 inches the arm would probably be 12 inches and 14 
 inches. 
 
 Calf (skin measurement). — The limb to be held stiff and straight, the heel raised from 
 the ground, the toes pressed strongly down, and the knee braced back. The tape is to be 
 passed around the thickest part of the calf ; and as the position of this line will somewhat 
 vary with different men, and with the same limb in different stages of development, one 
 or two points should be tried and that which shows the greatest girth selected. 
 
 Thigh (skin measurement). — The limb placed as in preceding measurement, the tape 
 to be passed in a horizontal line around the thickest part of the limb, which will be at 
 the highest point of the thigh admitting of horizontal measurement. 
 
552 HYGIENE 
 
 2. The Effect of Exercise upon the Muscular and Nervous 
 
 Systems 
 
 Of the exact changes which take place in active muscle, and of the 
 circumstances attending muscular contraction, it is needless to deal at any 
 length. The matter is fully considered in every text-book of physiology. 
 
 The following brief account of the metabolism in nuiscle may be given. 
 In an active muscle the blood-vessels are dilated. The neutral or feebly 
 alkaline reaction of the passive structure becomes an acid reaction when the 
 muscle is contracting, owing, it is supposed, to the formation of paralactic 
 acid. A considerable quantity of carbon dioxide is excreted from the active 
 muscle, while a large proportion of oxygen is consumed. The amount of 
 glycogen and grape sugar is diminished in an active muscle, the tissue of 
 which contains less extractives soluble in water, but more extractives soluble 
 in alcohol. During exercise the amount of water in muscular tissue increases, 
 while that of the blood is diminished in proportion. Heat is formed in a 
 muscle in a state of activity. 
 
 Turning to more general matters concerning the muscular system, it has 
 been well said that ' function makes structure,' and it is certain that muscular 
 exercise makes muscular tissue. Not only is the exercised muscle increased in 
 size, both as a whole and as far as its individual parts are concerned, but there 
 is eliminated from it such tissue as is other than muscular. The fat contained 
 among its meshes is reduced to a minimum, the connective tissue is lessened 
 in amount, the aponeurotic parts are strengthened, and the structure of the 
 muscle is so amended that it is hampered by no material other than that 
 concerned in actual movement. It is freed, moreover, of such nitrogenous 
 substances as are capable of giving rise to superabundant waste products of 
 combustion. 
 
 There is a limit, of course, to the growth of muscles, and muscles exer- 
 cised to too great an extent will, after attaining a certain size, commence to 
 waste. The contractile force of the muscle is increased and an improvement 
 takes place in those conditions which insure the speedy and complete con- 
 traction of its fibres. It has been pointed out that the muscles of an athlete 
 when in training contract with extraordinary force under the electric current : 
 the muscular sense is developed to its utmost, and the circumstances in- 
 volved in the performance of a reflex act are placed under improved conditions ; 
 the power of co-ordination possessed by the individual is augmented ; 
 he acquires the art of causing muscles, which may be said to have been 
 hitherto estranged, to act in concert, so that movements which were com- 
 plex and effected with difficulty are ultimately carried out with ease. In this 
 way the nervous system is saved a great expenditure of force. Acts which 
 were performed with effort and by conscious will become automatic, and there 
 is a saving in the expenditure of active force in the spinal cord and m the 
 cerebral cortex. Complicated movements become ' organically registered in 
 the brain ' and cease to be difficult. One conspicuous feature in muscular 
 training is the increase in the possibilities of automatism. As time goes on, 
 and the individual practises more and more, he finds the work become easier 
 and easier. This depends, not only upon an increase in the actual strength 
 of the parts, but upon the greater ease with which the muscles concerned act 
 in co-ordination and upon the muscular experience of the individual, which 
 prevents him from misplacing his strength, and enables him to attain a desired 
 end with the minimum amount of force. 
 
 He who is beginning to practise any muscular exercise, such as fencing, 
 
PHYSICAL EDUCATION 553 
 
 bicycling, or rowing, will I'eel that he moves stiffly. The constant connnont 
 of the instructor in physical exercises is, ' Don't keep so stiff ! ' ' Let your 
 arms go loose ! ' The beginner has not yet learnt how to balance one set 
 of muscles against their antagonists. His movements are at first very 
 deliberately planned, but in time the will ceases to concern itself. A memory 
 is developed in the spinal cord and in the muscular centres, and one great 
 element of fatigue is removed. 
 
 Nothing in physical training is more remarkable than the economy of 
 force which results from muscular education. The well-trained athlete, 
 moreover, acquires the art of using his respiratory muscles with the greatest 
 ■economy. He does not exhaust himself with needlessly vigorous breathing ; 
 he learns to precisely regulate his respiratory movements to his immediate 
 needs, and he brings the muscles of his thorax into co-ordination with the 
 ■other muscles which he employs. 
 
 Just as muscles increase with use and waste with disuse, so the whole nerve 
 apparatus concerned in movement is structurally improved by systematic 
 exercise. The athletic man has better developed nerves, a more elaborate 
 organisation of his spinal cord and of certain parts of his brain, than 
 has the individual whose muscular system is imperfectly formed. Just as a 
 certain segment of the spinal cord and of the cerebral cortex wastes after the 
 removal of a limb, so it may be inferred that those parts become hyper- 
 irophied and elaborated when the limb in question is unusually employed. 
 
 ' The differences,' writes Sir Crichton Browne, ' which we notice between 
 man and man in deportment, gait, and expression are but the outward and 
 visible signs of individual variations in the development of the motor centres 
 ■of the brain ; and the stammerings, grimacings, twitchings, and antics which 
 are so common and annoying, alike to those who suffer and who witness 
 them, are probably in many instances the effects of neglected education of 
 some of those centres, and might have been abolished by timely drill and 
 •discipline.' 
 
 He who has been well trained physically possesses not only a complete 
 but an intelligent use of his muscles. His movements are powerful, are 
 under absolute control, are precise, and capable of the finest and most 
 elaborate adjustment. 
 
 The art of the athlete consists, not in employing the greatest amount of 
 power in effecting a movement, but in carrying out that movement with the 
 least possible expenditure of force. The tyro at cycling will use an amount 
 of muscular force in riding a mile which would probably carry an experienced 
 rider some twenty miles. 
 
 3. The Effect of Exercise upon the Tissues and Organs generally 
 
 It is needless in this place to deal with the subject of bodily heat, with 
 the manner in which it is developed and employed, with the conditions which 
 regulate it and attend its disposal. It is necessary only to say that in the 
 body work and heat are always associated, and it is believed that the heat is 
 the cause, and not the effect, of the work. No muscular contraction can 
 occur without the production of heat, but of the precise manner in which 
 heat acts upon muscle and makes it contract little is known. 
 
 Commenting upon this matter Dr. Lagrange, in his work on ' The 
 Physiology of Bodily Exercise ' (page 37), observes : ' Heat causes in 
 muscular fibres the first stage of contraction, or at least an aptitude for 
 coming into action more quickly under the influence of the will. A heated 
 muscle seems to have stored, in a sense, a latent force. It has been ascer- 
 
554 HYGIENE 
 
 tained that the maximum aptitude for contraction is exhibited by human 
 muscles at about 40° C. It follows that a man whose muscles are at this 
 temperature is able to act more quickly, and at once can make use of all his 
 force. 
 
 ' A bodily exercise is performed with more vigour and ease when heat has 
 raised the temperature of the muscles. This fact is so well known that there 
 are characteristic phrases to express it in common speech. We say of a 
 man beginning an exercise of strength or skill whose movements have not 
 yet acquired all their force and precision, that he has not yet warmed to his 
 work.' 
 
 The author compares the preliminary canter before a race, the preliminary 
 sparring before a fight, and the strange movements of an angry animal before 
 an attack, to the heating up of a locomotive. It may be pointed out, also, that 
 there is a greater aptitude for bodily exercises in summer than in winter, and 
 that muscular action becomes temporarily paralysed by great cold. 
 
 The heat produced in the body depends upon certain chemical changes in 
 the tisssues, certain combustions which are mostly, but not exclusively, 
 oxidations. These products of combustion, or of dissimilation, examples of 
 which are afforded by carbon dioxide, urea, uric acid, &c., are noxious to life 
 and must be ejected from the body in one way or another through the agency 
 of special organs. The effects produced by an excess or by a retention of 
 these products are dealt with in discussing the subject of fatigue. 
 
 Muscular exercise tends, moreover, to remove any accumulation of fat 
 which may exist in the tissues. Fat is the type of what are known as the 
 reserve tissues. It serves the part of fuel for combustion ; it undergoes 
 dissimilation with remarkable ease, and may therefore be regarded as fuel of 
 a most combustible character. As fat forms no permanent structural part 
 of the organism, its removal is, within limits, effected with no incon- 
 venience. The fat man who takes exercise ffnds that he soon becomes 
 breathless and fatigued. His unwonted muscular exertion involves a great 
 series of combustion processes. Fat would appear to be of all substances 
 the one W'hich most readily lends itself as material for such changes. The 
 result is that in the corpulent individual the products of dissimilation are 
 produced in excess, and he becomes, in a certain sense, poisoned by the 
 accumulation of these products (see chapter on Fatigue ). He is hampered 
 also by the unnecessary weight of his body, by his feeble muscles, and 
 possibly, to some extent, by the mechanical obstacles offered by collections 
 of fat. A corpulent man in rowing finds that his large abdomen is an 
 actual mechanical obstacle in the way of his movements. 
 
 A fat man when in training loses his fat. As he becomes thinner he 
 becomes stronger, his muscles act better, he is less breathless on exertion, 
 less fatigued after long-continued effort, and may in time reach that excellent 
 state of health known as ' good condition.' 
 
 The fat disappears first from the limbs, especially from the limbs which 
 are particularly employed. Last of all the internal accumulations disappear, 
 and the last feature to go will probably be the large abdomen, which is so 
 terrible a trial to would-be athletes of middle age. 
 
 It may here be said that the deposit of a certain amount of fat within the 
 abdomen is a common accompaniment of advancing age, and that its forma- 
 tion can best be prevented by exercise, and especially by such exercises as 
 involve the contraction of the abdominal muscles. It is exceedingly rare to 
 see a waterman who keeps up a good style of rowing present an unduly 
 prominent abdomen. 
 
 Exercise, moreover, tends to improve the condition of the tissues generally.. 
 
PHYSICAL EDUCATION 
 
 Tlie soft parts become firmer, more resistant, less easily bruised when 
 damaged, and in all respects sounder. A man in training is said to be ' hard,' 
 and it is well known that no moderate blow will raise a bruise upon the 
 person of a prize fighter when he is in perfect ' condition.' The general 
 standard of the nutritive activity of the body is improved. The stout and 
 flabby man becomes thinner, harder, and firmer under training. 
 
 The thin and spare man, on the other hand, often becomes stouter under 
 training. He feels better, eats better, and his powers of nutrition are so 
 improved that he gains flesh and weight. 
 
 Thus training may cause one man to lose weight and another to gain it,. 
 and both to look healthier and better for the change. 
 
 As Dr. Lagrange well expresses it, ' Exercise produces in the system two 
 absolutely different effects : it increases the process of assimilation, thank& 
 to which the body gains new tissues, and it accelerates the process of dissi- 
 milation, which leads to the destruction of certain materials.' Its action in 
 the former direction depends upon the increased amount of oxygen intro- 
 duced into the system by the improved circulation and respiration and by the 
 healthy stimulation of the various active organs of the body. 
 
 The need for exercise is felt as much by thin people, who assimilate too 
 little, as by fat people, who do not dissimilate enough. Exercise may there- 
 fore be regarded as a great regulator of nutrition. 
 
 As the action of the heart rapidly increases in force and frequency 
 during exercise, the flow of blood through all parts of the body is increased. 
 The amount of increase is from ten to thirty beats, but it may be more. The 
 skin becomes red with the blood contained in the full capillaries and perspira- 
 tion is much increased. The amount of fluid which is lost by the skin is 
 very considerable. 
 
 The digestive apparatus is stimulated and strengthened by exercise. The 
 appetite improves, digestion is more complete, absorption more rapid, and the 
 circulation through the liver is more vigorous and even. 
 
 Muscular exercises, especially such as employ the muscles of the abdomen, 
 have a very beneficial effect upon the bowels, promoting peristaltic movements 
 and reUeving such constipation as depends upon the torpidity of the intestine. 
 
 One other conspicuous effect of exercise is the increased elimination of 
 carbon. This is eliminated mainly by the lungs. The observations of 
 Pettenkofer and Voit give the following results : — 
 
 Table IX. 
 
 - 
 
 ■ 
 
 Absorption of 
 oxygen in 
 grammes 
 
 Elimination in grammes of 
 
 Rest day . 
 Work day- 
 
 708-9 
 954-5 
 
 Carbonic acid 
 
 911-5 
 
 1284-2 
 
 Water 
 
 828-0 
 
 2042-1 
 
 Urea 
 37-2 
 37-0 
 
 Excess on work day 
 (with exeeption of 
 urea) . 
 
 246-6 
 
 372-7 
 
 1214-1 
 
 -0-2 
 
 It is demonstrated that a considerable formation of carbonic acid takes 
 place in the muscles. As, moreover, exercise is clearly necessary for a suffi- 
 cient elimination of carbon from the body, it is needful in a condition of pro- 
 longed rest that the amount of carbon in the food be lessened to avoid an 
 accumulation of that element in the tissues. 
 
556 HYGIENE 
 
 With regard to the vexed question of the elimination of nitrogen from 
 the body during exercise, Parkes condudes his careful examination of the 
 subject in these words : — 
 
 * On the whole, if I have stated the facts correctly, the efl'ect of exercise 
 is certainly to inlluence the elimination of nitrogen by the kidneys, but within 
 various limits, and the time of increase is in the period of rest succeeding 
 the exercise ; while during the exercise period the evidence, though not 
 certain, points rather to a lessening of the elimination of nitrogen. 
 
 * It would appear from these facts that well-fed persons taking exercise 
 would require a little more nitrogen in the food, and it is certain, as a matter 
 of experience, that persons undergoing laborious work do take more nitro- 
 genous food. This is the case also with animals.' 
 
 Dr. Parkes thus sums up the action of exercise upon the kidneys : ' The 
 water of the urine and the chloride of sodium often lessen in consequence 
 of the increased passage from the skin. The urea is not much changed. 
 The uric acid increases after great exertion, so also apparently the pig- 
 ment ; the phosphoric acid is not augmented ; the sulphuric acid is moderately 
 increased ; the free carbonic acid of the urine is increased ; the chlorides are 
 lessened on account of the outflow by the skin ; the exact amount of the 
 bases has not been determined, but a greater excess of soda and potash is 
 eliminated than of lime or magnesia. Nothing certain is known as to 
 hippuric acid, sugar, or other substances.' 
 
 4. The Effect of Exeecise upon Pbesonaij Comeliness and Comfort 
 
 We have already noted the effect a systematic training may have upon the 
 growth and development of the body, upon the size of the chest, and the 
 proportions of the limbs. Such training, moreover, can give an upright and 
 symmetrical figure and an easy and graceful carriage. There is a swing 
 about the body and a bearing of the head and shoulders which mark those 
 whose muscular system has been fully developed. 
 
 Under proper training the shuffling and shambling gait disappears, the 
 loutish boy ceases to look loutish, and the gawky girl no longer excites com- 
 ment ; rounded shoulders become square and bending backs are made straight. 
 
 The athlete, so far as his body and his personal equation are concerned, 
 has reached the full and perfect stature of a man, and the girl whose 
 physical education has been complete reaches her point of physical perfection 
 as a woman. The beauty of the body depends upon a fully formed skeleton 
 and perfectly developed muscles, and not upon deposits of fat. The arm of 
 a plump but ill-developed woman is rounded and free from conspicuous pro- 
 minences about the elbow, but the outline is as meaningless and as unnatural 
 as the part is flabby and lifeless. The arm of a woman in perfect physical con- 
 dition has, on the other hand, an exquisite outline. It presents the contour given 
 it by the muscles that move the limb. The graceful configuration of these 
 muscles has not been hidden beneath a monotonous layer of fat. The arm has 
 an individuality and has reached the perfection of its growth. The beauty 
 of the right arm of many female violinists is a matter of common comment. 
 
 Unfortunately there is comparatively little fat about joints, and the most 
 trying feature in the feebly developed woman is a bony elbow. There are 
 masses of muscle about the elbow, and if these are wasted the details of the 
 skeleton become unpleasantly conspicuous. If they are, on the contrary, 
 Avell developed, the contour of the elbow becomes even and graceful. The 
 arm of an individual who is not only thin but is also ill- developed is an un- 
 pleasant spectacle — it is a burlesque of a human limb. 
 
PHYSICAL EDUCATION 557 
 
 In the neck and the upper part of the chest the effects of a sound physical 
 traimng are very conspicuous. The long turkey-hke neck of the ill-developed 
 lad and the scraggy neck of the ill-nurtured woman are familiar enough. 
 They are both unnecessary disfigurements. 
 
 A perfectly shaped thorax gives to the human figure its most striking 
 feature, and such a chest cannot be met with among those whose physical 
 education has been quite neglected. There is little excuse for an ill-formed 
 thorax, and yet at the present day it is met with on all sides and in all classes 
 of the community. 
 
 The back of the ill-developed is characteristic. The spinous processes of 
 the vertebrae, instead of being sunk in a median groove formed by the two 
 great masses of the vertebral muscles, stand out in the form of an irregular 
 nodulated ridge. The back looks feeble, lifeless, wasted, and there is an air 
 of muscular pauperism about it. It looks poor, and yet it must be owned 
 that it is the type of back very commonly met with among the favoured classes, 
 and especially among the women. 
 
 The tissues of the ill-developed are flabby, doughy, baggy. They lack 
 elasticity and consistence. The cheek of the overworked shop assistant who 
 gets no real exercise can be seen to shake as he walks along the street. 
 
 The purposeless-looking extremities of those who are physically un- 
 educated are well known. They have the appearance of the limbs of indi- 
 viduals who are recovering from serious illness. They are, as a matter of 
 fact, the extremities of persons who have never been well. 
 
 The tissues of the well-developed are firm, elastic, resisting, active, and full 
 of evidence of living. There is given to every part of the surface of the body 
 that rapid change in contour and that indescribable aspect of vigour and 
 soundness which are features of a healthy and well-knit frame. 
 
 In the above comments I am alluding merely to the results of a systematic 
 physical training, and not to such exceptional results of muscular exercise 
 as produce professional gymnasts and acrobats. 
 
 Undue and unsymmetrical muscular development may deform the body ; 
 a circumstance well illustrated by some acrobats, whose lower limbs are of 
 normal or sub-normal development, while their arms are enormous, their- 
 shoulders mountainous and uncouth, their necks coarse and bullock-hke, and 
 the upper part of the back arched or bowed. This is especially noticeable in 
 gymnasts who practise upon the trapeze, horizontal bar, and other apparatus, 
 and who have exclusively developed the muscles of the upper half of the trunk.. 
 
 The skin of those who have taken pains to bring their bodies to perfection 
 often compares in a marked manner with the integument of the neglected 
 and uneducated. It is firm, clear, and wholesome. It is not to be argued 
 that exercise will keep the integument free from marks and blotches, and render 
 a naturally coarse skin fine, but it will bring about such differences in appear- 
 ance as serve to distinguish what is healthy from what is unsound. The 
 delicate and sensitive complexion of a young woman whose physical training 
 has been efficient is in conspicuous contrast with the dull, loose, lustreless 
 integument of the abstainer from muscular pursuits. 'The skin of the 
 recluse is grey, greasy, and unpleasant-looking. The complexion of the 
 young man about town is almost distinctive. It is aggressively unwholesome, 
 and forms a contrast with that of his companion who has just returned from 
 a shooting expedition or a long boating tour. Exercise, of course, involves 
 more living in the open, a freer and deeper respiration, and the coursing of a 
 more vigorous flow of blood through the integuments ; it leads actually to a 
 sounder state of the general health, and such improvement is at once evident 
 upon the skin. There is a certain brightness and vivacity of the look, and a. 
 
558 HYGIENE 
 
 certain degree of self-assertion iu the carriage, of those wlio are in sound 
 physical condition. They contrast with the wan, hopeless-looking creatures 
 who never ' stir out of the house,' and who crawl through life in a semi- 
 apologetic manner. 
 
 In the matter of personal comfort no greater sense of pure pleasure can 
 influence the human mind than that which results from perfect health. 
 There is the glorious delight of movement and of vigorous activity, quite 
 apart from the excitement and mental enjoyment wliich attend so many 
 recreations and outdoor sports. The lad Avho is m perfect physical condition 
 wakes up in the morning, fresh and rampant ; and if it be the summer time he 
 probably feels an irresistible impulse to dash out into the open air and fill 
 his lungs and quicken his pulse and move his muscles. Even the fatigue 
 that comes over a man who is in good condition, and who has taken a long 
 spell at exercise, is pleasurable. Such a one eats well and digests well ; 
 the functions of his body are carried on normally, and he experiences to its 
 full the delight of living. 
 
 The youth who takes no exercise, who is always poring over his books, 
 misses at least one-half of the enjoyments which are available to man during 
 a comparatively short life. He is a dull creature, dyspeptic probably, the 
 subject of headaches, constipation, and many minor ills. To him joy cometh 
 not in the morning, and in the place of an honest fatigue he has the ' fidgets * 
 and his weariness is painful. His appetite is feeble possibly, his circulation 
 is poor, and very often he sleeps badly, and can envy the easy and profound 
 sleep of a companion who has come home after a long run across country. 
 The simplest, the purest, and the pleasantest recollections in hfe usually go 
 back to certain physical enjoyments in the open air, to some walking tour or 
 cricket match, to some river expedition, or to some great day upon the moors. 
 
 When sudden exercise is forced upon the undeveloped individual, he is 
 more or less unable to meet it ; he becomes breathless, perspires violently, is 
 uncertain of himself, is clumsy and the subsequent victim of a painful degree 
 of fatigue. Of such a person it cannot be said — 
 
 Yea, this iu him was the peculiar grace, 
 That before liviu" he learned how to live. 
 
 5. The Mental akd Moeal Effects op Exekcise 
 
 Moderate, regular, and systematic exercise by stimulating the circulation 
 of the body improves also the circulation of the brain, and is therefore an 
 aid to cerebral movements. It improves the health and the physical strength, 
 and so increases the capability of the individual for mental work and for the 
 physical strain incident upon mental concentration. 
 
 By organising in the brain a series of muscular movements, by elaborat- 
 ing the powers of co-ordination, and by establishing automatism in a large 
 and varied series of actions, it saves actual brain- work and renders a con- 
 siderable number of movements independent of the direct action of the 
 will. 
 
 It offers, too, an admirable change of employment. There is no better 
 rest from severe mental work than well-selected bodily exercise. With many 
 men to lie upon a beach and throAv stones into the water is no rest. They 
 would find a more complete repose in the pleasurable use of their muscles, 
 in the pursuit of some congenial outdoor sport, and in rendering dormant 
 the energies of one part of the nervous system by an engrossing employment 
 of another part. 
 
PHYSICAL EDUCATION 559 
 
 Such exercises as are indulged in when seeking rest from mental work 
 must be simple and, so far as possible, such as are automatically performed. 
 
 * Prescribe fencing, gymnastics with apparatus, and lessons in a riding 
 school,' writes Dr. Lagrange, ' to all those idle persons whose brain languishes 
 for want of work. The effort of will and the work of co-ordination which 
 these exercises demand will give a salutary stimulus to the torpid cerebral 
 cells. But for a child overworked at school, for a person whose nerve-centres 
 are congested owing to persistent mental effort in preparing for an examina- 
 tion, for such we must prescribe long walks, the easily learnt exercise of 
 rowing, and, failing better, the old game of leap frog and prisoner's base, 
 running games — anything, in fact, rather than difficult exercises and acro- 
 batic gymnastics.' 
 
 ' Mr. Charles Paget, at one time M.P. for Nottingham, tried in the village 
 school on his estate at Euddington a very interesting experiment. He 
 was not satisfied with the general progress made by the boys, and he 
 provided for them a large garden. The school was then divided into two 
 sections, one of which was kept to the ordinary school work for the ordinary 
 hours, the other for half of these hours only, the rest of the school-time being 
 devoted to work in the garden. At the end of the term the half time, or 
 gardening boys, had excelled the others in every respect — in conduct, in dili- 
 gence, and in the results of study ' (' Health Exhibition Manuals,' vol. xi. 
 p. 327). 
 
 There must be a proper distribution of mental and physical work. Just 
 as ' all work and no play makes Jack a dull boy,' so all play and no work 
 makes Jack a still duller boy. 
 
 An excessive and absorbing indulgence in physical exercises is un- 
 doubtedly bad. It tends to make the individual too much of an animal and 
 to afford neither time, opportunity, nor suitable conditions for the develop- 
 ment of his brain. Under such circumstances even the body tends to be- 
 come stunted if the practice be commenced early, and the lad develops not 
 only an animal look, but some of the intellectual and emotional attributes of 
 the animal. 
 
 Still, on the other hand, in these days of cramming and intense competi- 
 tion, many a successful man has to thank Providence for the late recognised 
 blessings of an idle youth. 
 
 The systematic and properly arranged pursuit of physical exercise tends 
 to develop certain admirable qualities, and notably those which are so much 
 prized among Englishmen, and which are well designated as ' manly.' 
 
 These qualities are brought out in those who are enthusiasts in out- 
 door sports and games. The football player has done more than merely 
 develop his muscles ; the man who has rowed in his college eight has learnt 
 something beyond the mysteries of the sliding seat ; and the experienced 
 ' player ' at almost any outdoor game has been improved by other means 
 than those which the actual manoeuvres of the game demand. Such lads 
 and men have learnt in a school where the principles of pluck, courage, 
 endurance, and self-reliance are acquired. They have probably learnt to be 
 ready, to be quick of eye and hand, and prompt in judgment. They may 
 have appreciated the value of disciphne and of self-control. They may have 
 felt the inspiration of the chivalry of days gone by, and have experienced 
 the influences of good fellowship and loyal comradeship. They may have 
 learnt what it is to be patient, to be fair, to be unselfish, and to be true. 
 
 Many a man who in later life finds himself in a dangerous strait would 
 wish for no one better by his side than the lad who pulled behind him 
 in a racing eight. The cries and the cheers of the football field must have 
 
5G0 HYGIENE 
 
 given heart to many a desperate soldier when hard pressed in the turmoil of 
 actual war, and a sailor can say no more gracious thing of his mate than that 
 he is ' a man to stand by you in a gale.' 
 
 There is a certain moral effect also which comes with a sound physical 
 training. The schoolboy who is foremost in athletic exercises will probably 
 be found to be more open, more straightforward, more simple, and more 
 Avholesome-minded than the lad who spends his time loafing at the pastry- 
 cook's. Mr. Cathcart in his ' Health Lectures ' (Edinburgh, 188-4) brings this 
 point well forward in the evidence he quotes from certain head-masters of 
 large public schools in England. One head-master writes : ' The worst boys 
 intellectually, physically, and morally are the loafers,' and another : ' The 
 boys who work hard and play hard do not ape the vices of men, and are free 
 from the insidious evils that often fasten on unoccupied boyhood.' 
 
 I think it may be safely said that that miserable creature, the juvenile 
 sexual hypochondriac, is never to be found among those who are foremost 
 at athletics and outdoor games. 
 
 FATIGUE 
 
 This subject will be considered under the following head? : 1. Breath- 
 lessness ; 2. Muscular Fatigue ; 3. Muscular. Stiffness ; 4. General Fatigue. 
 
 1. Beeathlessness 
 
 The breathlessuess which is a famihar attendant upon exercises of a 
 certain character has received but little notice at the hands of physio- 
 logists. Dr. Lagrange has in his recent work, to which allusion has been 
 already made, dealt very fully with the subject, and explains it by a theory 
 which appears to be both sound and satisfactory. The phenomena of breath - 
 lessness are familiar enough. One has but to picture a man of middle age,, 
 who is out of training, and who has set himself the task of running a certain 
 distance. He soonfeels embarrassed in his breathing ; he pants, his respiratory 
 movements become jerky and irregular ; he is aware of a terrible sense of 
 oppression in his chest, a sense which increases with each step. His head 
 throbs ; he begins to find that his strength is failing him ; he feels that he 
 could run many more yards, so far as his legs are concerned, but the sense of 
 suffocation arrests him. He staggers along, his steps become uncertain, his 
 face haggard, his movements irregular, and he stops at last dead beat. As 
 he rests he continues for many minutes to breathe in the same troubled way. 
 The man is said to be ' blown,' to have ' lost his wind.' He has used his 
 legs, but his legs have not given way. It is his chest which has failed him. 
 This constitutes the remarkable feature of the phenomenon. The same man 
 can exercise his arms with dumb-bells for three times the time occupied by 
 the run, yet he is not ' out of breath.' He can row for ten miles without 
 being inconvenienced, but he cannot run up two flights of steep stairs with- 
 out being rendered quite breathless. The more athletic the man, the better 
 condition of training he is in, the more practice he has had, the less breath- 
 less he becomes ; but the most perfect athlete, even when in his prime, can 
 soon ' pump himself out ' if he tries. 
 
 Dr. Lagrange offers the folloA^ing explanation of the phenomenon : — 
 Breathlessness is a form of dyspnoea due to an excess of carbon dioxide 
 in the blood. The excess of this gas leads to an increase of the respiratory 
 need. The condition may be spoken of as auto -intoxication of the body by 
 one of its own products of dissimilation — carbon dioxide. 
 
PHYSICAL EDUCATION 5G1 
 
 This excess of carbonic acid is produced by muscular work. It is a con- 
 spicuous product of such work, and it must be remembered that the 
 muscles form at least half the weight of the entire body. The larger the 
 muscles employed, and the more vigorous their action, the greater is the 
 amount of the gas produced. The intensity of breathlessiiess during exercise 
 is in direct proportion to the expenditure of force demanded in a given 
 time. Eunning involves rapid contractions of the great mass of muscles 
 forming the lower extremities. It induces breathlessness quicker than does 
 moderate rowing, where the muscular expenditure in a given time is much 
 less. ' The quantity of carbonic acid,' writes Dr. Lagrange, ' produced 
 by a group of muscles in a given time is in proportion to the amount of work 
 they do. Further, the work which a group of muscles is able to do without 
 fatigue is in direct ratio to the power, that is, to the number and size of the 
 muscles forming this group. If, then, an exercise is localised in a very small 
 group of muscles, fatigue will ensue before a large quantity of work has been 
 done, and before a large dose of carbonic acid has been poured into the blood. 
 The eliminating power of the lungs will exceed the power for work of the 
 active muscles ; muscular fatigue will precede breathlessness. If, on the 
 other hand, the muscles put in action are very numerous and very powerful, 
 they will be able before being fatigued to perform a large quantity of work, 
 and consequently to produce a very large dose of carbonic acid. Their power 
 for work will exceed the eliminating power of the lungs. Breathlessness 
 will this time precede fatigue.' 
 
 It is said that a horse ' trots with its legs and gallops with its lungs.' 
 The gallop of a horse may be slowed down until the animal falls behind 
 another horse which is trotting. Nevertheless, however slow the gallop may 
 be, it will more quickly ' pump ' a horse than an equally rapid trot. Swiftness 
 of movement does not suffice to produce breathlessness unless combined with 
 intensity of muscular effort. 
 
 In breathlessness it is not inspiration which is difficult, but expiration. 
 In running, inspiration is free, easy, deep, three times as long as expiration. 
 The latter, on the other hand, is short, insufficient, and painful. 
 
 It is stated that in man there is discharged m a given time by respira- 
 tion 
 
 0*35 gramme of carbonic acid during sleep. 
 0"60 ,, ,, ,, while sitting. 
 
 1"65 ,, „ „ while running. 
 
 As accessory causes of breathlessness are certain disturbances in the cir- 
 culation of the blood and some engorgement of the lungs resulting there- 
 from. These changes are discussed by Dr. Lagrange in the following 
 words : — 
 
 ' The first result of violent exercise is the quickening of the blood current 
 and a consequent active congestion of the lungs. In these exercises the lungs 
 are very quickly engorged with blood, and there is great need for their dis- 
 embarrassment by increasing the activity of the blood current. The move- 
 ment of inspiration increases the velocity of the current by a force of 
 aspiration which tends to empty the over-filled capillaries. This aspiration 
 lasts as long as the enlargement of the thorax continues ; hence this move- 
 ment is an assistance to the breathless man ; on the other hand, as the thorax 
 is diminishing in size during the expiratory movement, the blood current 
 becomes slower and the lungs more engorged. Hence the discomfort and the 
 irresistible impulse to a prompt repetition of the inspiratory movement. 
 
 ' We may say that the lungs of the breathless man are placed between two 
 different needs. On the one hand, they have to drive out carbonic acid and 
 
 VOL. I. 
 
502 HYGIENE 
 
 the other products of dissimilation, and for this a long expiration would be 
 necessary ; but, on the other hand, they have to free themselves from vascular 
 engorgement, and therefore expiration is cut short to return to inspiration, 
 which helps the circulation through the lungs.' 
 
 Dr. Lagrange divides breathlessness into three stages, and, as he is the 
 only writer wlio has fully dealt with this subject, the matter cannot be better 
 discussed than in his own words : — 
 
 ' In the first stcujc the respiratory movements are increased in frequency 
 and in extent. The production of carbonic acid is increased, but, the respi- 
 ratory energy being greater, there is an equilibrium between the needs of 
 the organism, which demands a more active elimination of this gas, and the 
 working of the lungs, which is powerful enough to satisfy these needs. 
 During a time which varies much with the individual, with his constitution, 
 with his resistance to fatigue, and, above all, with his power of directing his 
 respiration, gained from his respiratory education, these are only symptoms 
 of greater vital activity, and there are as yet no signs of functional disturb- 
 ance, no sensation which rises to the degree of discomfort. The man has a 
 general sensation of warmth, some throbbing of the temples, and has an ani- 
 mated appearance, flushed, his eyes sparkling, and a general aspect of cheer- 
 fulness, due to the greater activity of the circulation and the resulting active 
 congestions. In a word, it is the stage in which exercise causes a greater 
 intensity of life without reaching the degree of discomfoi-t or of danger. 
 
 ' Here we have the really salutary dose of exercise, the limits within which 
 we must keep in order that work may cause ns no inconvenience. But 
 nothing varies more with the individual than the duration of this inoffensive 
 period, which is, in a sense, the preface of breathlessness. In some persons 
 it is as long as an hour, in others the stage in which discomfort begins is 
 reached in a few seconds. 
 
 ' If violent exercise be prolonged, the equilibrium is soon broken between 
 the production of carbonic acid, which becomes more and more abundant, 
 and the eliminating power of the lungs, which is insufficient to free the 
 organism from it. Eespiratory distress occurs. 
 
 ' In the second period the effects of insufficient respiration begin to show 
 themselves, a vague discomfort is experienced, which is most accentuated in 
 the pra3cordial region, but which is rapidly generalised throughout the body, 
 and notably affects the head. In the chest there is a feeling as if it were 
 oppressed by a weight, or bound down by a girdle of insufficient air. In the 
 head there are clouds obscuring sight, sparks before the eyes, then murmurs 
 and ringing in the ears, and finally a certain bluntness of sensation, a certain 
 confusion in impressions and in ideas. All these disturbances are due to the 
 action upon the nerve-centres of an excess of carbonic acid. They indicate 
 the beginning of intoxication. 
 
 ' In the face, remarkable changes are to be noticed, which are the conse- 
 quences of the respiratory distress, and of the efforts made to draw a greater 
 quantity of air into the chest. The nostrils are dilated, the mouth and 
 eyes widely opened. They all seem to be widely opened to favour the 
 entrance of the air which the lungs so greatly need. 
 
 ' The colour of a breathless man shows very striking modifications. At 
 the beginning of exercise we have said that there is animation, more colour 
 in the face, due to active congestion. But in the second period the picture 
 has changed. To the lively red colour has succeeded a pale and wan tint. 
 There is something peculiar about this pallor — it is not uniform. Certain 
 parts of the" face, such as the lips and the cheeks, have a violet blackish 
 appearance ; the rest of the face is white and colourless. 
 
PHYSICAL EDUCATION 563 
 
 ' From the two colours, one darker and the other Hghter, there results 
 a grey, leaden, livid appearance. The violet tint is due to the retention of 
 blood in the capillaries, which are losing their elasticity, and in which the 
 ■circulation is faihng. This blood, overcharged with carbonic acid, has lost 
 its bright red colour, hence in the lips and other more transparent parts 
 of the face we see no longer the ordinary red colour ; they have the blackish 
 colour characteristic of venous blood. 
 
 ' As for the pallor, this is due to a transient anaemia, to the emptying of 
 the arterioles. The heart, the energy of which diminishes in proportion to 
 the increase of the breathlessness, does not send forward a sufficient quantity 
 of blood, and it is easy to understand that a part receiving less blood is less 
 deeply coloured than usual. 
 
 * The leaden hue of the face in a breathless man indicates an already 
 profound disturbance of the system. In no case should exercise be continued 
 after it comes on, for it indicates the beginning of asphyxia. 
 
 ' It is at this stage of breathlessness that we observe the very characteristic 
 change in the rhythm of respiration which has been already described. 
 The ordinary rhythm is lost, and the two periods of respiration become 
 unequal. The first period increases and the second diminishes ; inspiration 
 becomes three times as long as expiration. This change in the rhythm of 
 respiration is an indication of blood stasis in the capillaries of the lungs. 
 As soon as it occurs we can see that the organism, its force exhausted, can 
 no longer fight to good purpose against the poisonous substance which 
 permeates it. The congested lungs eliminate less carbonic acid than is 
 formed by the muscles at work. Intoxication is imminent. 
 
 ' If exercise be continued, the gravity of the condition rapidly increases. 
 We may call the asphyxial stage the third phase of breathlessness into 
 which the organism passes under the influence of forced exercise. 
 
 ' This third stage is as follows. To the respiratory distress succeeds a 
 sensation of anguish generalised throughout the organism. The head feels 
 as if bound by an iron band. Vertigo is very distressing. All sensations 
 become more vague ; the brain is overcome by a kind of drunkenness. The 
 subject begins to become unconscious of what is passing, his muscles continue 
 to work mechanically for a time, then they stop, and the man falls in a 
 faint. 
 
 ' At this time respiration is of a different type to that of the last stage ; the 
 two periods are both short, jerky, occasionally interrupted ; with them are 
 mingled swallowing movements and hiccough. The heart-beat is feeble 
 and intermittent. The pulse is small, irregular, and imperceptible. When 
 exercise is continued to these extreme limits it is almost always stopped by 
 grave syncope, and unless prompt help be given the syncope may be fatal.' 
 
 An athletic man soon develops the art of regulating his breathing so as 
 to reduce the degree of breathlessness as far as is possible. He is aware 
 that it is at first that the trouble is intense, and that in time he can adjust 
 the difficulty a little. The runner speaks of getting ' his second wind.' He 
 has passed through a period of breathlessness in which excitement, sudden 
 movement, and unnecessarily extreme muscular contractions possibly have 
 played some part ; he then settles down to his work, he uses his forces more 
 economically and breathes more easily ; and it is common to hear a man out 
 of condition explain the loss of a race by the fact that he never got his 
 * second wind.' 
 
 In sprint running the art of controlling breathlessness reaches its highest 
 point, and to some extent sprint running is a test of the respiratory capacity 
 in this direction. 
 
 o2 
 
5G1 HYGIENE 
 
 2, MuscuLAE Fatigue 
 
 If a man in sound health hold out his arm at right angles to his body he 
 experiences, in a time which varies according to his physical condition,, 
 so much inconvenience in the muscles involved that he is at last com- 
 pelled to drop the limb. If he exercise his will to the utmost he may 
 prolong the period of extension, but a time soon comes when by no possible 
 effort can he continue to hold out the extremity. 
 
 The muscles in question are said to be fatigued. 
 
 The fatigue is termed relative because, if a proper electric current b& 
 applied to the muscles as soon as the limb is dropped as helpless, the muscles 
 again contract, and the hand is once more lifted. 
 
 If the muscles of an animal be subjected to an electric current they con- 
 tract ; on repeating the application they contract again and again. The 
 contractions, however, become feebler, and are in time ultimately abolished. 
 The parts are in the condition of relative fatigue. 
 
 If now a stronger current be employed, the muscles again contract, and 
 again in time lose their power. The experiment can be continued with a 
 stronger current until finally the muscles camiot be made to contract by any 
 cmTent or any stimulus of any kind. 
 
 They have reached the state of absolute fatigue. 
 
 Local fatigue of muscle is explained by the following conditions : — 
 
 1. The actual power or function of the muscle is exhausted. This con- 
 dition has been termed ' dynamic exhaustion,' and is parallel to the exhaus- 
 tion which is noticed in certain reflex acts when they are indefinitely excited, 
 and to the exhaustion of the retina to certain rays when one colour is con- 
 templated for too long a time. 
 
 The functional power of a muscle is placed within definite limits, and in 
 fatigue that limit is reached. This exhaustion is modified by the strength 
 of the muscle, by its local condition, by the practice it has been subjected to, 
 and by the nerve condition of the individual. 
 
 2. In fatigue, nerve exhaustion is largely concerned. This especially 
 applies to complicated acts, the repetition of which involves a special and 
 definite effort of the will. 
 
 The comparative absence of exhaustion in the incessant movements in 
 chorea is explained by the circumstance that in these movements a voluntary 
 nerve mechanism is not concerned. Dr. Lagrange lays down the axiom that, 
 ' the muscular work being equal, the sensation of fatigue is the more intense 
 the more active the intervention of the cerebral faculties demanded by the 
 exercise.' 
 
 3. Some local effect may be exercised upon the muscle by the products of 
 combustion or dissimilation which are developed within its tissues, and which, 
 not being got rid of in time enough, accumulate in excess. 
 
 * If,' WTites Dr. Lagrange, ' w^e submit the muscles of a frog to the action 
 of a powerful electric stimulus, and prolong this action until fatigue is com- 
 plete, that is, till the limbs of the animal remain motionless under the most 
 powerful stimulation, we shall have in the fatigued muscles the elements 
 necessary for a most curious experiment. Their substance rubbed in a mortar 
 and made into a fine soup contains a principle capable of producing in 
 healthy muscle at rest the fatigue which had exhausted the first muscles. 
 If we inject into a second frog this extract of fatigued muscles, we bring 
 about in this animal all the phenomena of fatigue, and its limbs will fail to 
 respond to electric stimuli.' 
 
PHYSICAL EDUCATION 565 
 
 The possible character of this local effect is thus dealt with by Landois in 
 his -well-known ' Text-book of Physiology ' (translated by Stirling). The 
 «ause of local muscular fatigue ' is probably partly due to the accumulation 
 of decomposition products — "fatigue stuffs" — in the muscular tissue, these 
 products being formed within the muscle itself during its activity. They are 
 phosphoric acid, either free or in the form of acid phosphates, acid potassium 
 phosphate, glycerin-phosphoric acid (?), and carbonic acid. If these substances 
 be removed from a muscle by passing through its blood-vessels an indiffer- 
 ence solution of common salt . . . the muscle again becomes capable of 
 energising.' 
 
 Dr. Lagrange gives a more detailed account of these tissue changes, and 
 in adding his account it is necessary to say that his statements are not 
 entirely in accord with the teaching of most physiologists. 
 
 ' Muscles which have worked to excess have undergone a change in their 
 chemical composition. Alkaline in a state of repose, they have become acid ; 
 they contain lactic acid, which was not present before work ; they contain 
 less oxygen and more carbonic acid than when at rest. Numerous nitrogen- 
 ous materials resulting from the combustion of muscular tissues are consider- 
 .ably increased. These substances, of which the last stage of combustion is 
 nrea, form a series of bodies only differing in containing more or less oxygen, 
 and being consequently at a different degree of oxidation or combustion. All 
 .authors enumerate amongst them kreatin, hypoxanthin, inosite, &c., and 
 finally the best known one, and the most interesting because of the part it 
 plays in the production of gout, uric acid.' 
 
 4. It is possible also that some actual lesion, such as that attending the 
 compression of nerves, may occur in a fatigued muscle and may serve to 
 partly explain the tenderness of the overused structure and to estabhsh a 
 condition akin to that produced by the violent and irregular contractions of 
 •cramp. 
 
 3. Muscular Stiffness 
 
 Another feature associated with local fatigue, with the overuse of muscle, 
 is stiffness. This is a common but not a necessary accompaniment of the 
 over-work. 
 
 A rowing man who is entirely out of condition, and who has taken no 
 exercise for months, is asked to fill up a place in a racing four for a short 
 ' practice.' He finds the exertion a terrible strain ; he soon becomes breathless, 
 his limbs ache, his head throbs, every limb seems out of condition, and he is 
 soon exhausted. He does his best through the short spin, but next day he 
 aches all over. He is stiff. He feels as if he had been beaten. He cannot 
 move without some pain, nor can he grasp any part of his body without dis- 
 covering some tenderness. 
 
 In a day or so the unpleasant condition passes off. This very man may 
 have rowed many races without experiencing a trace of stiffness. He may 
 have gone through three times the amount of exertion without any but 
 momentary inconvenience. The difference has been simply this. At one 
 time he was in practice and in condition, at the other time he was both 
 out of practice and out of condition. 
 
 The intensity of the stiffness is not always proportionate to the imme- 
 diate fatigue, nor is the extent of the exercise a measure of the stiffness which 
 may result. 
 
 Stiffness depends rather upon the condition of the individual than upon 
 the character or amount of the muscular work done. Muscles may be 
 fatigued without afterwards becoming stiff. 
 
5GG HYGIENE 
 
 The local symptoms of stiffness probably depend upon an exaggeration of 
 those conditions in the muscles which are supposed to underlie local fatigue,, 
 and notably to the retention in the tissues of the products of combustion. 
 
 These local changes have already been described. 
 
 4. Geneeal Fatigue 
 
 The general disturbances Avhich may accompany muscular exhaustion, 
 and which are present in some degree in such fatigue as is attended by 
 stiffness are of'very varying character. 
 
 The indi\'idual may be left simply exhausted, ' tired out,' listless, and to 
 some extent prostrate. 
 
 In more advanced degrees he complains of heaviness in the head, of utter 
 feebleness, of inability to take food, and of painful weariness and restlessness 
 followed by want of sleep. 
 
 In other and still more pronounced cases he may exhibit febrile pheno- 
 mena and present the condition described as the ' fever of over-exertion.' 
 This fever may be attended with such malaise and with such nerve dis- 
 turbances as to be mistaken for the early period of an infective fever. 
 
 This coiidition has been elaborately considered by Dr. Knott, of Dublin, in 
 his excellent monograph on ' The Fever of Over-exertion ' (Dublin, 1888). 
 He takes the case of a greatly overworked farm labourer. The symptoms may 
 or may not commence with a rigor. The patient's temperature runs up rapidly,, 
 even to 103° F. or 101° F. within a few hours, and this change is accompanied 
 by the general symptoms of malaise, congested face, thirst, loss of appetite. 
 Sec. He soinetimes takes a day or two of rest, when, feeling a little better, 
 he makes a desperate effort to go back to work, although still suffering from 
 the same symptoms in a slighter degree. His efforts are now necessarily 
 less vigorous, but he does enough to feed the slow fire of febrile combustion 
 which has been already kindled in his muscles. 
 
 The temperature maintains a standard of about 101° or so ; the pulse is 
 permanently quickened ; thirst, constipation, loss of appetite, and loaded urine 
 contmue. 
 
 In such cases, when the pernicious attempts at manual exertion are con- 
 tinued for a number of days, the unhappy individual afterwards fails to 
 recover. Gradual wasting goes on ; the pulse maintains its frequency and 
 becomes weaker, the strength by degrees fails, the patient is obliged to take 
 to bed, the fever tends, after some months, to assume a hectic type. 
 Increasing emaciation is marked, and the patient not very rarely falls a 
 victim to some intercurrent disease. 
 
 Dr. Knott ascribes the phenomena to the throwing into the circulation of 
 a greatly disproportionate quantity of the products of muscular waste. These, 
 he maintains, lead to an overthrow of the governing powers of the thermo- 
 toxic nerve centre, or, in other words, are the substantial cause of the fever. 
 He considers that urea and uric acid represent the most important of these 
 products. 
 
 Dr. Lagrange supports the same view, and contends that the marked con- 
 stitutional disturbances which may follow upon severe muscular exercise are 
 all due to the accumulation in the circulation of a large excess of the 
 chemical products of muscular waste, to a species of self-infection by the 
 excess of combustion products developed in the muscles. He also considers 
 that these products are mainly represented by urea and allied compounds. 
 
 It is noteworthy that a degree of fatigue leading to muscular stiffness, 
 but not necessarily to the constitutional symptoms named, will be attended. 
 
PHYSICAL EDUCATION 5G7 
 
 by a deposit of urates in the urine. This may be quite independent of any 
 fever. 
 
 Those who pursue athletic exercises are well aware of the association 
 of a deposit in the urine with the appearance of stiffness. In a man out 
 of condition the tissue waste induced during unwonted exercise is very con- 
 siderable. The tissues afford abundant reserve material for the necessary 
 combustions. The nutritive condition of his muscles is comparatively low. 
 In an athlete in training, on the other hand, the material available for com- 
 bustion is not in excess. The tissues have long been rid of all superfluous 
 matter. The nutritive state of the muscles is in the best possible condition, 
 and the circumstances which favour the development of a great deposit of 
 urates is not forthcoming. 
 
 EFFECTS OF EXCESSIVE OR UNSUITABLE EXEECISE 
 
 It is unnecessary to deal in a separate section with the ill-effects of an 
 absence of physical exercise upon the body. The matter has been considered 
 in such of the foregoing paragraphs as are concerned in the general effect 
 of muscular exercises. 
 
 In estimating the actual value of the work done in any physical pursuit, or 
 in attempting to express what is meant by ' excessive ' or ' unsuitable ' in 
 relation with muscular labour, I have been unable to make any use of the 
 physiological method of measuring work by ' foot-tons.' This mode of mea- 
 surement is no doubt of value to the physiologist, but to those concerned 
 in physical education it is practically useless. Many of the results do not 
 accord with what would be inferred from practical experience, nor can they 
 be put to any practical use. The amount of muscular expenditure incurred 
 in rowing one mile at racing speed is said to be represented by 18*56 
 foot-tons. But walking a mile at an ordinary pace causes an expenditure of 
 17*67 foot-tons, from which it must be inferred that there is very little differ- 
 ence between these two forms of exercise, so far as the use of the muscles is 
 concerned. Those who are interested in athletic matters would not be able to 
 recognise the correctness nor the value of these estimates, especially when they 
 are compared with one another. Even when every allowance is made for the 
 quickness of the stroke and the breathlessness induced by rowing at a racing 
 pace, yet still it would be urged that the actual output of muscular force 
 would be represented by a different figure when such exercise is compared 
 with the walking of one mile. 
 
 Bowing six miles at racing speed would, upon the same estimate, be re- 
 presented by 111*36 foot-tons, while walking the same distance would be ex- 
 pressed by 106*02 foot-tons — a result which makes the comparison still more 
 marked. 
 
 So far as the present purpose of this paper is concerned, the terms ' ex- 
 cessive exercise ' and ' unsuitable exercise ' must be considered relatively, and 
 with reference rather to the individual than to the actual physiological 
 amount of muscular work expended. 
 
 What may be excessive or unsuitable exercise to one man may be moderate 
 and quite excellent exercise to another. 
 
 In considering the phenomena of fatigue and the effects of any given 
 exertion the estimate must be based upon the condition of the individual 
 rather than upon the actual character of the work carried out. In this matter 
 the age and bodily development of the man, the state of his general health, 
 and the scope and extent of his muscular education play prominent and 
 essential parts. 
 
5G3 HYGIENE 
 
 The effects whicli may follow upon excessive or unsuitable exercise, or 
 upon exercise which, from the point of view of him who practises it, may be 
 termed violent on the one hand and rash on the other, are very varied. 
 
 We have seen in the sections on breathlessness and on general fatigue 
 what results may follow after severe exertion, so far especially as the respi- 
 ratory functions and the general state of the body arc concerned. 
 
 A sprint runner may fall senseless upon the path, succumbing to the 
 results of his breathlessness. 
 
 A boy may remain completely ' knocked up ' for several days after a paper- 
 chase, and may be really ill and exhibit the febrile phenomena which have 
 been already described. 
 
 There is no doubt that in not a few instances the pursuit of violent and 
 extreme exercise has led to results which have had a permanent effect upon 
 the health of the individual. In some cases an actual organic lesion has 
 been produced ; in others the body has been placed in a condition favourable 
 for the development of disease ; in a third series of instances there super- 
 venes merely a feebler state of health. 
 
 The children of tubercular parents have acquired a spinal caries, or a 
 diseased joint, as a result of injuries received through improper gymnastic 
 exercises. 
 
 Children wit\) a weak muscular system have acquired a lateral curvature 
 of the spine through the pursuit of unsuitable exercises, which, so far as their 
 spinal muscles are concerned, have been excessive and unequal. 
 
 It may be true, as is often asserted, that phthisis has appeared in those 
 who are phthisically incHned, as a result of the strain and the exposure 
 incident to severe exercises of endurance in the open air. 
 
 Many serious troubles may certainly be ascribed to acts of indiscretion 
 and to exposure to cold and wet under trying circumstances during the 
 pursuit of physical exercise ; but such ills can scarcely be laid at the door of 
 muscular training. The attack of acute rheumatism, which may have followed 
 a long boating tour in the late autumn, may more justly be ascribed to camp- 
 ing out in the wet than to the effect of mere rowing. 
 
 Quite apart from any obvious lesion or disease, not a few individuals 
 appear to suffer permanently in health as the result of some specific excess 
 in the matter of exercise. A lad may ' knock up' after winning a three-mile 
 race, and never be fit for much in the matter of athletics after that. A man 
 of about middle age may, with probable reason, date a distinct and persistent 
 decline in health to some one holiday in Switzerland, when he did more 
 than his age and his condition justified. 
 
 Many inferences of this character may be unsound, but a few appear to 
 be undoubted. 
 
 On the whole, however, it must be allowed that the injury which may 
 follow, and no doubt has now and then followed, upon severe physical 
 exertion represents but a small fraction when compared with the undoubted 
 benefits which accrue from moderate and reasonable exercise. 
 
 Dr. John E. Morgan, of Manchester, in a work entitled ' University Oars : 
 a Critical Inquiry into the Health of the IMen who Rowed in the Oxford and 
 Cambridge Boatrace, from 1829 to 18G9,' has dealt with the effect of 
 violent exercise, as illustrated by racing in boats, upon the general 
 health. 
 
 His evidence shows that such exercise is, in the great majority of instances, 
 no other than beneficial ; that it is not a cause of disease or of premature 
 death ; and that, out of the large number of individuals dealt with, in only 
 the insignificant proportion of G per cent, could any permanent ill effect 
 
PHYSICAL EDUCATION 5G0 
 
 be claimed to have followed the pursuits of earlier years. In most of 
 these cases even the evidence that rowing was to blame was indefinite or 
 doubtful. 
 
 Mr. Walter Eye, the well-known authority on cross-country running, 
 writes thus : ' We can speak from an experience now covering nearly twenty 
 years, and can positively say that we know of no man of the hundreds with 
 whom we have been acquainted who has been injured by distance running, 
 and the rate of mortality among running men is singularly small.' 
 
 Similar evidence has been given by others with regard to forms of athletic 
 exercise which may be considered to be violent. 
 
 Certain specific effects which may follow upon excessive or unsuitable 
 exercise will now be considered. 
 
 The Heart and Blood-vessels 
 
 The heart has been ruptured during very violent exertion, as in attempting 
 to lift or support an immense weight. This has happened to men of great 
 muscular strength, but more often to the feeble, the ill-conditioned, or the aged. 
 
 Excessive exercise may lead also to hypertrophy of the heart, to dilatation 
 of its cavities, and to valvular disease. The cases of hypertrophy appear to be 
 most usual in the athletic, and in those whose employments involve constant 
 severe labour — e.g. blacksmiths, miners, &c. In the matter of dilatation of 
 the heart. Dr. W- Osier writes (Pepper's ' Medicine,' vol. iii. p. 631) : ' Over- 
 training and heart-strain are closely connected with the question of excessive 
 dilatation during severe muscular effort. Both mean the same thing in many 
 cases. A man, perhaps not in very good condition, calls upon his heart for 
 much extra work during a race or the ascent of a very steep mountain, and is 
 seized with cardiac pain and a feeling of distension in the epigastrium, and 
 the rapid breathing continues an unusual time, but the symptoms pass off 
 after a night's quiet. An attempt to repeat the exercise is followed by 
 another attack, and, indeed, an attack of cardiac dyspnoea may come on 
 while he is at rest. For months such a man may be unfitted for severe 
 exertion or may be permanently incapacitated. He has overstrained his 
 heart and has become broken- winded.' 
 
 HaBmorrhages of various kinds have resulted from, or have been ascribed 
 to, violent exertion, and have been met with in almost all parts of the 
 body. Cases of cerebral and of spinal apoplexy have occurred during extreme 
 exertion, and Lagrange mentions an instance in which the spinal veins 
 underwent rupture and led to paraplegia. 
 
 Aneuetsm 
 
 The part played by exercise in the production of aneurysm is definite, but 
 at the same time not necessarily predominating. In addition to violent 
 movement come the factors of actual injury to the vessel, constitutional 
 diseases, especially syphilis, and the conditions which lead to chronic arteritis. 
 The author once saw a popliteal aneurysm in an acrobat of twenty-eight, who 
 was in perfect health, and who considered it had been developed by the practice 
 of hanging by the knees from one trapeze while he caught his companion, who 
 was swinging from another. In this case great and well-localised x^ressure 
 was exerted upon the ham. The form of exercise which appears to be most 
 effective in the production of aneurysm is violent intermittent exercise, or 
 sudden exercise when out of condition, or such actions as involve extreme 
 movements of certain articulations. 
 
 Aneurysm is much more common in men than in women, and in the 
 
570 HYGIENE 
 
 labouring than in the favoured classes. It is noteworthy that in the etiology 
 of aneurysm age plays a conspicuous part. Aneurysm is not most common 
 at the age when violent physical exercises are most usually indulged in, but 
 it is most frequent in individuals who have reached or have passed middle 
 life. The occurrence of aneurysm under these circumstances affords another 
 argument against the folly of violent and extreme exertion in men who are 
 over thirty, especially when they are out of condition. 
 
 Varicose Veins 
 
 The frequently repeated statement that varicose veins in the lower limbs 
 are produced and maintained by exercise is based upon very questionable 
 foundations. It is said upon equally questionable grounds that those who 
 indulge in running, bicycling, riding, or exercises involving long standing 
 are in great risk of developing varicose veins. It is quite true that dilated 
 veins are met with among athletes, runners, and bicyclists ; but it has not 
 been shown that the condition is more common among them than it is with 
 other individuals, and, on the other hand, it is easy to produce any number 
 of professional runners, athletes, gymnasts, and others who are constantly 
 practising the very exercises which are said to produce varicose veins, and yet 
 have not an enlarged vein in either of their lower hmbs. 
 
 It is remarkable, moreover, that varicose veins are so much more common 
 among women than among men, and that they are very often met with in 
 women who take httle or no exercise. There is, in fact, evidence to show 
 that exercise has little if anything to do with the production of the disease ; 
 that the trouble is due to certain congenital defects in the vessels them- 
 selves, and that when such defect does exist muscular exertion may tend to 
 increase the abnormal condition. This view is very strongly insisted upon 
 by Mr. Bennett in his elaborate monograph upon ' Varicose Veins ' (London, 
 1889). He shows that there is a distinct hereditary history in more than 
 60 per cent, of the cases. His cases prove that the trouble occurs in the 
 active and the sedentary, in the weak and the strong, in the short and the 
 tall. In females pregnancy and constipation play a conspicuous part in the 
 etiology. Bennett is unable to connect the occupation of the patient in any 
 definite degree with the actual production of the disease. While exercise 
 probably has nothing to do with originating varices, it certainly tends to 
 increase the trouble when it exists. Eunning, walking, jumping, cycling, 
 and forms of exercise and recreation involving long standing are noteworthy 
 in their ill effects upon varicose veins. Indulgence in these exercises would 
 be unwise for those who are the actual subjects of the disease, but the 
 fear of enlarged veins should never be an obstacle in the way of a free 
 pursuit of the sports mentioned, nor can the possibility of varicose veins be 
 legitimately urged as an argument against these sports. 
 
 The Lungs 
 
 Haemoptysis and emphysema are stated to have been produced by violent 
 exertion, and many chronic lung troubles have no doubt followed upon ex- 
 posure and neglect during and after such exertion. Dr. Parkes states that 
 congestion of the lungs may follow upon excessive or badly arranged 
 exercise. 
 
 Bones and Muscles 
 
 Bones have been fractured by pure muscular violence, notably, the 
 clavicle and humerus, but in the majority of such instances the bone has 
 proved to have been diseased at the seat of fracture. 
 
PHYSICAL EDUCATION 571 
 
 Violent exercise may lead to all kinds of lesions of the muscles. Muscles 
 may be ruptured in whole or in part, tendons may be rent across or torn 
 away from the bone, or may be displaced from the grooves in which they lie. 
 In many instances the subject of these lesions is out of condition, or is in 
 feeble health or aged, or is suffering from definite disease. 
 
 The Hon. E. Lyttleton well says (' Health Exhibition Manuals,' vol. x. 
 p. 121): ' To an athlete the first premonition of coming old age is to sprain 
 himself somewhere.' 
 
 Muscles which are over-exercised for a considerable time waste and 
 become soft. The legs of professional runners are occasionally quite atro- 
 phied from over-use of the muscles of the parts. 
 
 The abuse of certain movements and the excessive repetition of the same 
 may lead to some permanent contraction of the muscles concerned. Thus in 
 professional gymnasts who use the flexors of the arm to excess the elbow may 
 be found to be a little flexed and full extension of the joint to be impossible. 
 Sailors on sailing vessels who are constantly holding or hauling ropes not 
 infrequently develop a condition of the hand which prevents full extension 
 of the fingers. 
 
 The finer muscles when unreasonably employed may become the subject 
 of such nervous changes as are illustrated by writer's cramp and other forms 
 of spasm incident to certain employments. 
 
 Joints may be injured by violent exertion. Synovitis may follow upon 
 over-use of an articulation, and one very common accident among the athletic 
 is a displaced semilunar cartilage in the knee-joint. 
 
 Certain deformities of the body may follow restricted and often repeated 
 exercises and the excessive employment of certain muscles. Gymnasts who 
 have developed to an extreme degree the muscles of the upper limbs and upper 
 half of the trunk have a rounded back in addition to their unwieldy shoulders. 
 
 Fencing tends to produce a lateral curvature of the spine with (in right- 
 handed fencers) the concavity of the curve to the right. The author has 
 observed a permanent degree of lordosis in an acrobat who produced extra- 
 ordinary results by his power of bending the body backwards at the lumbar 
 region. 
 
 Hernia 
 
 The influence of muscular exertion in the etiology of hernia is so fully 
 dealt with in the ordinary text-books of Surgery that it need not be considered 
 at length in this place. 
 
 In cases of congenital hernia and in such other forms as depend upon 
 defects in the vaginal process of the peritoneum, and in those instances of 
 hernia generally which are met with in young children, the rupture is made 
 manifest by some expulsive effort as a rule, and not by any movements that 
 can be considered as constituting exercise. 
 
 Acquired hernise are beyond doubt produced by forces tending to cause the 
 intestines to protrude. 
 
 Violent effort is a recognised factor in the production of these ruptures. 
 It is very rarely indeed, however, the sole factor. Certain anatomical con- 
 ditions are present which render a hernia possible in one man and almost 
 impossible in another. 
 
 It is noteworthy that the main safeguard against hernia is a perfect and 
 vigorous muscular development. The greater number of examples of acquired 
 hernia are met with, not only in men of imperfect muscular development, but 
 in individuals who are out of condition. Such hernife are commoner in 
 
572 HYGIENE 
 
 those who return to hihorious work after an illness or when in feebler 
 health, in men who undertake heavy work without any preliminary training, 
 in persons who by reason of their age or their habits are losing muscular tone, 
 are becoming coarse, soft, andtlabby, are developing fat within the abdomen, 
 and wbo exhibit the phenomena of relaxed tissue. Gymnasts and acrobats, 
 in spite of the immense muscular efforts they put forth, are seldom the sub- 
 jects of hernia. If they become ruptured the hernia will appear late in their 
 career, at a time when they are falling off and losing tone, or at any period 
 when they are out of condition and out of training. 
 
 Carefully selected, systematic, and well-graduated exercise is the best 
 protection against hernia, and the objections against athletics founded 
 upon the production of hernia are unjust and unsound. An acquired 
 umbiUcal hernia is unknown in muscular men ^vith firm abdominal walls. 
 It is common in those who have large, flabby, and pendulous bellies and 
 who take no exercise at all. So far as acquired hernia is concerned, it would 
 be more accurate to state that rupture is due to want of exercise rather than 
 to excessive indulgence in the same. 
 
 TEAINING 
 
 With ' training ' in the sense of preparing the body for athletic competi- 
 tions and great feats of endurance the present article has no concern. The 
 subject may be considered only in so far as it throws hght upon the mode of 
 living which may be observed by those who are anxious to get themselves 
 into condition and to take a considerable amount of moderate exercise. 
 
 Upon this subject a number of books, pamphlets, and articles have been 
 written, and, it must be confessed, a great deal of nonsense promulgated. 
 
 Strange elements of superstition and gross ignorance have entered into the 
 older methods of training, and there are still professional athletes who keep 
 the details of their training secret or who ascribe their success to some 
 article of food or some particular rite or observance. 
 
 The old system of training was quite remarkable. The unfortunate man 
 had his weight reduced by profuse sweating, especially by walking and 
 running in thick and heavy clothes. He was purged every day, he was 
 almost starved in the matter of water, and took sparingly of old ale, spirits, 
 and port. He lived mainly upon half-cooked beefsteaks and bread, and was 
 encouraged to gorge himself upon this monotonous diet. 
 
 Matters are now entirely changed, so far, at least, as amateur athletes are 
 concerned, and without entering into detail as to the exact methods practised 
 by one modern system or another, the general features of a reasonable mode 
 of training may be briefly discussed. 
 
 In the first place, time must be considered. ' A man of twenty-five and 
 upwards,' writes Mr. Woodgate, ' who has been lying by for months, or it may 
 be for a year or two, can do with three months of training. The first 
 half should be less severe than the last. He can get into " hunting " condi- 
 tion in the first six weeks and progress to " racing" condition in the suc- 
 ceeding six. University crews train from five to six weeks. College crews 
 cannot give much more than three weeks to train for the summer bumping 
 races.' 
 
 During training a man's life must be as regular as a clock : his meals 
 must be taken to the minute, his exercises must be systematised and so ad- 
 justed as to be progressive and well-timed. He should retire to bed early 
 and rise early, should sleep in a well-ventilated room, should bathe night 
 
• . PHYSICAL EDUCATION 573 
 
 and morning, should be particular as to the kind of clothing worn, and 
 take every precaution to avoid cold. In all things he should be moderate 
 and methodical. His meals are best represented by a substantial breakfast, 
 a light lunch, a still lighter tea, and a substantial dinner in the evening 
 when his day's work is over. He should take plenty of sleep. He should 
 rest after each meal. Smoking should be absolutely forbidden, and no form 
 of alcohol should be allowed. There is overwhelming evidence to support 
 the practice of training upon water. In the matter of diet a man should be 
 moderate, should not gorge himself, and should, within certain limits, con- 
 sult his own taste in the selection of food. 
 
 He will do best with the most easily digested foods, and may take 
 beef, mutton, chicken, fish, and game, while he should avoid pork and veal 
 and lobster and other well-accredited producers of dyspepsia. He should 
 under no circumstances be debarred from eating fat and butter. A man in 
 training needs a good supply of carbon in his food. 
 
 It is well to avoid much sloppy food, such as soups and broths, to be very 
 moderate in the consumption of starchy foods and of sugar, to avoid coarse 
 vegetables and large quantities of potatoes. Some green vegetables and some 
 fruit should be taken every day. It is needless to say that he should avoid 
 pastry and sweets and the confused and uncertain forms of food known as 
 entrees. Cheese may well be omitted from his dietary and salad take a con- 
 stant place. Meat will be eaten at breakfast, lunch, and dinner. 
 
 In the matter of liquids, he should not drink for the sake of drinking. 
 He should take as much only as is needed to quench his thirst, and he 
 should not consider the time of his drinking. The custom of allowing men 
 to drink only a certain quantity of water at certain fixed times of the day 
 is obviously silly. A man should drink when he is thirsty, and should not 
 be compelled to suffer with a parched mouth simply because the drinking 
 hour has not come. Men differ immensely m the quantity of fluid they 
 need. The matter cannot be settled by rule. It may be taken as certain 
 that the least quantity is consumed when taken in small amounts, and often, 
 and not when the individual has been tortured with thirst and swallows a 
 quart or more vrhen his time for drinking comes. 
 
 Under a reasonable and liberal system of training no man should break 
 down or become, as the expression goes, ' stale.' 
 
 The old system of training was rather a test of strength than a means of 
 developing it, and those who train in modern times should make themselves 
 familiar with the follies of those who trained in days gone by. 
 
 SPECIFIC EXEECISES 
 
 Walking 
 
 is the most usual, the most simple, the most easy, and one of the most valu- 
 able modes of taking exercise. It is suited for individuals of all ages and of 
 all states of development. It is the main exercise of the quite young child, 
 a prominent feature in the training of the athlete, and usually the only form 
 of exercise indulged in by the aged. 
 
 It is a mode of exercise which requires neither apparatus nor special 
 locality, and there can be few so engaged in the pursuit of living as to find 
 a legitimate excuse for not indulging in this simple means of kee]Ding the 
 body in health. 
 
 While walking exercises mainly the muscles of the legs, it brings into 
 
574 HYGIENE 
 
 play also the muscles of the loin and of the back and abdomen. Not only 
 has the individual to move, he has also to keep erect. The circulation and 
 respiratory movements are increased, and the general beneficial effects of 
 exercise are brought about. 
 
 The actual mechanics of walking and the precise nature and extent of 
 the movements involved are admirably illustrated by the photographs pub- 
 lished by Mr. Eadweard Muybridge, of Philadelphia. Certain of these are 
 reproduced with a very lucid explanation in Keating's * Cyclopaedia of the 
 Diseases of Children ' (vol. iv. 1891). 
 
 Walking is distinct from marching, in which a less easy attitude of the 
 body is maintained. Other things being equal, slow walking is more tiring 
 than walking at a moderate pace. 
 
 It is important that the style of walking be cultivated, that the' spine 
 be kept straight, the head erect, and the shoulders well back. An easy and 
 perfectly graceful mode of walking is not common among civilised people. 
 The countryman rolls along walking from his hips, the over-dressed lady 
 steps stiffly and gingerly like an automaton, the untrained lad slouches in a 
 manner well termed slovenly. 
 
 A purposeless walk, such as is the common exercise and often the only 
 exercise in ladies' schools, where the pupils walk in procession, side by side, 
 over a stated distance, is somewhat depressing and does not develop the 
 exercise to its fullest. Walking with an object represents the best and most 
 pleasant form of this element in physical training. Shooting involves, not 
 only the delights and excitement of sport, and the use of the hands and 
 arms, but also a long walk over often irregular and difficult ground. The 
 admirable game of golf, which is said to date from the time of Edward III., 
 represents one of the very best forms of walking Avith an object. This game 
 has a fascination both for the young and the old, and is one of the most 
 perfect and in every way the most admirable form of exercise for men who 
 are past middle life or have reached old age. 
 
 Walking races are contests more or less of endurance, and test rather 
 the staying powers than the skill or the muscular strength of the competitor. 
 ]\f any professional walkers walk vilely. In walking for a race ' it is abso- 
 lutely necessary,' writes a great authority (Mr. Shearman), 'to have the 
 muscles so hard all over the body that " knocking off" for any space of time 
 becomes fatal to all chances of success.' 
 
 In walking competitions the mile has been covered in 6 min. 23 sec, 
 three miles in 20 min. 21^ sec, twenty miles in less than 3 hours, and fifty 
 miles in less than 8 hours. 
 
 EUNNING 
 
 is the exercise for children and young people. It employs the muscles of 
 nearly the whole of the body and, by increasmg the rate and depth of the 
 respirations, is an admirable element in developing the chest. Children 
 appear to be the subjects of an irresistible impulse to run, an impulse that 
 should never be checked. 
 
 Running has been described as a succession of leaps. It undoubtedly has 
 a most beneficial effect upoii the circulation of the viscera, strengthens the 
 heart, when indulged in in moderation brings out the individual's powers 
 of endurance as well as his strength and his capacity for rapid movement. 
 
 Muybridge's photographs show the mechanical details of the act of 
 running very clearly. A reproduction of two of these photographs in 
 Keating's ' Cyclopaedia ' Hoc. cit.) may be advantageously consulted. 
 
 Eunning, to any extent, as an exercise is not advisable after the age 
 
PHYSICAL EDUCATION 675 
 
 of thirty, nor in those who have not kept themselves in practice and 
 in sound condition. In the aged it may be ranked often as actually 
 dangerous. The best ages for running are between eighteen and twenty-five, 
 and upon few forms of athletic exercise does age tell more certainly and 
 a<ccurately than in this. 
 
 So far as athletic excellence is concerned, it may be said that a runner is 
 born, not made. There are many wlio would never attain a first position 
 as runners in spite of unlimited practice. Sprint running or sprinting is the 
 term applied to running a short distance at top speed without a break. 
 Three hundred yards is considered to represent the limit of sprinting dis- 
 tance. ' In sprinting,' writes Mr. Shearman, ' the front muscles of the thigh 
 which bring the leg forward are the most important factors for speed, as it 
 is on the rapid repetition of the stride that the main result depends ; in the 
 running of longer distances the back muscles of the thigh, which effect the 
 propulsion, bear the chief strain. Both sets of muscles are, of course, used 
 in every race, but the longer the distance the less important the front 
 muscles become.' The sprinter, however, runs rather with his lungs and 
 heart than with his legs. Breathlessness is the difficulty with which he has 
 to contend. Thus it happens that the sprinter may be tall or short, may be 
 a feather weight or scale at 13 stone, may have limbs like a deer or calves 
 which would cause the envy of a footman. 
 
 Long-distance running is a matter, not only of strength, but also of 
 endurance and lung power. Some of the best long-distance runners have 
 been short men, very strong, light of weight, and with large and deep chests. 
 
 Hare and hounds and the paper-chase form most exciting and admirable 
 forms of running. The sport, however, is only open to those who are young, 
 who are in perfect condition, and who have increased the distances they 
 have run from time to time by gradual steps. 
 
 For children a hoop forms one of the most popular means of giving a 
 purpose to running and of infusing interest into what in the abstract is a 
 somewhat monotonous form of exercise. 
 
 On the racing track 100 yards has been covered in 10 sec, and 300 yards 
 in 30 sec. A mile has been completed in 4 min. 12| sec, three miles in 
 14 min. 29 sec, twenty miles in a few minutes short of two hours, and fifty 
 miles in a little short of six hours. 
 
 Jumping, 
 
 like running, has certain very definite age limits. Jumping in competi- 
 tions is limited to individuals under thirty or more usually under twenty- 
 five. Twenty may be taken as the best age. In jumping, the muscles 
 ■of the lower limb are of course mainly employed, but in addition to 
 these it will be noticed that nearly every muscle in the body is in action 
 as the leap is taken. The details of the movement are well shown in 
 Muybridge's photographs {see Keating's ' Cyclopedia,' vol. iv. photo v.). 
 
 A jumper of any excellence is, like a runner, born, not made. Celebrated 
 jumpers, especially long jumpers, have been of almost any size and weight. 
 W. B. Page, who cleared a height of 6 ft. 3;^ in., was only 5 ft. 6 in. in height. 
 
 Jumping as an element of physical education has some especial points 
 of value. It encourages very vigorous, instantaneous, and well co-ordinated 
 muscular contractions, and cultivates that form of muscle intelHgence which 
 is called spring. 
 
 I am of opinion that jumping is not quite the exercise for women or for 
 young girls who have passed the period of puberty. Certain uterine troubles 
 have with some show of reason been ascribed to an indulgence in this exer- 
 
576 HYCrlEXE 
 
 cise. For flabby people and young subjects who are disposed to be stout, 
 and for any who are not in very sound condition, the exercise is not with- 
 out risk. It may well be left to lads and to youths in the prime of athletic 
 life. 
 
 In the high jump 6 ft. 3^ in. have been cleared, and in the long jump the 
 remarkable distance of 23 ft. 2 in. 
 
 Allied to jumping must be considered the exercise of skipping. A more 
 admirable and more perfect form of exercise, considering its simplicity, could 
 not be practised. It employs the muscles, not only of the legs and loins, but 
 also of the back, abdomen, and neck, and even the muscles of the arms ; 
 it especially tends to strengthen the ankles and knees and the arches of 
 the foot ; it is admirable for children with weak backs ; it increases the 
 respiratory movements to a marked extent ; and if practised upon grass and 
 in the open air it is one of the most perfect forms of exercise for young girls 
 that could be devised. 
 
 Those who consider skipping too simple and too trivial to form a serious 
 element in a physical education may be surprised to know that many athletes 
 and gymnasts, and notably, it must be owned, prize fighters, take a very large 
 part of the exercise prescribed during training by means of the skipping-rope. 
 
 It would be well if those parents who consider that nothing in the way of 
 physical training can be done without a gymnasium or a drill-sergeant would 
 invest in a hoop and a skipping-rope and take note of the effect produced by 
 these simple means. 
 
 A skipping competition upon a lawn or in a field is, when kept within 
 limits, one of the most perfect forms of recreation a girl can indulge in. It 
 should be carried out in slippers or light shoes, and if it were a little more 
 popular the feeble ankles and flat feet which are so common among girls 
 and women would certainly be less often met with. 
 
 Skating 
 
 is another admirable exercise, especially valuable from the fact that it can 
 be practised at a time when few forms of outdoor recreation are possible, 
 and when girls and women are apt to sit at home and huddle over a fire or 
 weary themselves by dancing, until the small hours of the morning, in a 
 heated ballroom. 
 
 Skating is a form of modified walking, but it calls into play a greater 
 variety of muscles. The balance has to be maintained and the muscles of 
 the abdomen, back, and loins have much to do. It is exhilarating, it is 
 admirably adapted for persons of almost all ages, and is as well suited for 
 females as for males ; it comes at a time when the want of exercise in the 
 open air is probably telling upon the health and spirits ; it tends to give an 
 easy and graceful carriage to the body ; it strengthens the ankles and is a 
 fine antidote for the flimsier form of nervousness. No mode of progression 
 upon the feet is more delightful, easy, or invigorating. In a country 
 house when every form of indoor amusement has been exhausted, when the 
 roads are too dirty for walking and the ground too heavy for pleasant riding, 
 a hard black frost comes as a boon, and the manner in which the youv.g 
 and the old, the strong and the frail, turn out and hurry to the ice gives the 
 impression that the instinct for exercise in human beings is as strong as 
 the impulse which leads the duckling to the water. 
 
 In racing, the following distances have been covered in the times named : 
 100 yards in 10 sec, one mile in 3 min. 2G sec. ; three miles in 10 min. 33 sec, 
 twenty miles in 1 hr. 14 min. ; fifty miles in 4hrs. 13 min. 
 
PHYSICAL EDUCATION 577 
 
 ElDINO 
 
 is a mode of taking exercise and fresh air which is not open to all, and is 
 within certain narrow limits denied to the inhabitants of cities. 
 
 The muscles exercised in riding are those mainly of the adductor segment 
 of the thigh and of the back. The movement undoubtedly improves the 
 visceral circulation and affords a remedy for hepatic congestion and constipa- 
 tion ; it promotes a deeper respiration and a more active pulse ; it com- 
 bines in a remarkable manner both active and passive movement and is 
 a specific for the dyspepsia and other ills which attend a sedentary life ; 
 it provides a means of strengthening the spine, and it should be remembered 
 that a good ' seat ' implies rather the power of keeping the trunk well balanced 
 than the power of gripping the saddle with strong adductor muscles. 
 
 It is a pursuit that can be indulged in from childhood to old age, and it 
 is one of the most popular forms of exercise among Englishwomen. 
 
 Children should learn young and should be well taught. The exercise 
 is not good for girls with commencing lateral curvature, nor should it be 
 taken up by children who have ' outgrown their strength,' and are tall, weedy, 
 and of feeble muscular development, until the muscles have been strengthened 
 by other methods. Overgrown girls who indulge in no other exercise but 
 riding are apt to become round-shouldered and round-backed and to acquire 
 a very ungraceful seat. Lateral curvature of the spine is certainly often 
 induced and fostered by riding. 
 
 In any instance a young girl should be taught to ride upon either side of 
 the saddle, and this precaution should be especially observed in the case of 
 those who are supposed to have weak backs. After a very long ride a man 
 feels most tired in the lower part of his spine, and is very disposed to loll in 
 the saddle. In a young girl the most important muscular strain comes upon 
 the back, and is concerned in keeping the body erect. 
 
 It is not uncommon to see girls, who have been badly taught, riding with 
 the body much bent to one side or with the spine ' all in a heap ' and in the 
 attitude of cyphosis. Eiding is not the best kind of exercise for the round- 
 shouldered and for such girls as have unequally developed chests. 
 
 Horse exercise, so far as ladies are concerned, is a little hampered by the 
 fashion which demands that a riding habit shall fit like a glove and that, as 
 a consequence, the waist should be compressed so as to reach fashionable 
 proportions. The long skirt of the riding habit adds not a httle to the danger 
 of horse exercise for women. 
 
 Eiding forms an admirable exercise for men who have reached or 
 have passed middle life, and the saddle is very often the last thing that an 
 old sporting man relinquishes as infirmity creeps on. 
 
 Professional horsemen (grooms, postilions, jockeys, &c.) are apt to develop 
 a certain deformity of the lower limbs and back. The legs tend to become 
 concave or bowed, and seem often to have been stunted in growth. The 
 back — especially in jockeys — tends to become arched and rounded and the 
 shoulders high. An old ostler and an old jockey have often a quite charac- 
 teristic figure and attitude. 
 
 The deformity, such as it is, is evidently the result of style in riding, as 
 it is not observed in artillerymen and other cavalry soldiers 
 
 Swimming 
 
 should be taught as a matter of routine to every child, and it is a disgrace 
 to this country that this very simple accompUshment is so rare. Swimming 
 
 VOL. I. p p 
 
578 HYGIENE 
 
 is easily learnt at any age, and when once mastered is never forgotten. It 
 is acquired nearly as quickly by girls as by boys, and the first lessons may 
 be given between the ages of eight and ten. 
 
 Swimming calls into use a new set of muscles or rather a new combina- 
 tion of muscles. In the early struggles of the learner an immense amount 
 of force is expended in carrying out the unaccustomed movements. As pro- 
 ficiency is attained the movement becomes easier and easier, ruitil it is as 
 simple as walking, and the hmits of the swimmer's powers are restrained 
 rather by the temperature of the water than by his muscles. 
 
 Few modes of exercise are more enjoyable, especially when practised in a 
 broad river or the open sea. 
 
 The muscles of both the upper and lower extremities are concerned, and 
 to a lesser degree the muscles of the back and abdomen. The scapular 
 muscles, the deltoid, the pectorals, and, above all, the latissimus dorsi are 
 especially employed in swimming. The arms tire before the legs, and the 
 sense of exhaustion is always experienced most about the shoulder. 
 
 Work m a gymnasium is an excellent means of developing the swimming 
 muscles, and, so far as long distances are concerned, the chief factors are 
 strong arms and a good chest. 
 
 Swimming increases the respiratory movements and straightens the back. 
 The movements of the limbs are very free, and afi'ord a striking contrast to 
 most of the other forms of exercise which concern the lower hmbs. 
 
 Swimming should be well taught. Considering the facilities afforded in 
 this country for acquiring the art, it is astounding that among those who do 
 swim a fine and easy style of swimming is so rare. 
 
 Probably some 70 per cent, of those who can smm can just ' swim a 
 little,' and can do not more than keep themselves afloat by extravagant move- 
 ments for fifty or 100 yards. 
 
 I do not think that the practising of the swimming movements on land is 
 of much value, although it forms a great feature in the gymnastic course in 
 France. 
 
 The most remarkable swimming feat was that of Matthew Webb, who 
 swam from Dover to Calais in 21 hrs. 45 min. In a race 100 yards has been 
 covered in 1 min. 6 sec. 
 
 Fencing 
 
 In the Badminton Library volume on Fencing the history of this art is 
 detailed, together with the circumstances and manner of its development, and 
 to the account is appended a quite remarkable bibliography of the subject. 
 
 Fencing as it is at present pi'actised is an extremely scientific, precise, 
 and highly elaborated art. It is no mere slashing with a protected foil. 
 Every move has been systematised ; every method of attack and defence has 
 its individual name. The movements are as complex, and yet as well defined, 
 as the movements of the men upon a chessboard. No mode of exercise has 
 reached a more elaborate degree of finish. Fencing is pre-eminently an 
 exercise of skill. Considerable employment is given to all the muscles of the 
 body, to the lower hmbs, and to the back, but principally, it is needless to say, 
 to the right or sword arm. The beginner will after his first few lessons ache 
 from head to foot. He will believe that he has been fencing with every 
 muscle he possessed, a belief which will be well founded. As, however, he 
 becomes more proficient he will feel that the strain falls to a great extent upon 
 the right upper extremity. 
 
 Fencing is as much an exercise of the brain as of the muscles. He who 
 
PHYSICAL EDUCATION 579 
 
 lias acquired some proficiency in the art will find that he becomes tired in 
 his brain and cord rather than in his limbs. The bout induces rather a 
 nerve than a muscle fatigue. 
 
 Fencing develops certain faculties in an admirable manner. It requires 
 quickness of eye, extreme readiness of action, accurate muscular sense, great 
 precision and fineness of movement, and perfect powers of ready co-ordination. 
 It involves the practice of a quick decision, a rapid judgment, and a good 
 memory. A fool could never become a good fencer, even if he were endowed 
 with the most excellent physical qualifications. 
 
 Fencing has become more popular of late years, and is an excellent 
 •exercise for busy men. It is to be regretted that the practice often takes 
 place in somewhat ill-ventilated rooms. Fencing for elder children and 
 for ladies forms, as it is usually practised, but a somewhat imperfect develop- 
 ment of the proper art. It is not the exercise which would be recommended 
 'to excitable, nervous, or overworked children. It is better adapted for those 
 who appear to be apathetic and dull. A dull boy will find a fencing lesson 
 an infinitely greater ' fag ' than whole pages of irregular verbs. 
 
 It should never form for children, or, indeed, for adults, an exclusive or even 
 predominant form of exercise on account of the imequal muscular develop- 
 ment it encourages. It is well suited to encourage in lads and in elder girls 
 a good carriage, free movements, a lissom and graceful attitude of the body, 
 great agility, and both muscular and mental quickness. If it is possible 
 to make an individual ' sharp,' fencing may be considered as capable of 
 doing it. 
 
 The exercise must be recommended with great care. It would be in- 
 jurious to those who have a disposition to lateral curvature, and to any who 
 are the subjects of unequal muscular development. 
 
 In the physical education of the young it can occupy but a small space. 
 It is a perfect exercise for adults, especially for men who lead sedentary 
 and monotonous lives. Dr. Lagrange asserts that ' everyone who has fenced 
 much shows, in a more or less pronounced degree, a lateral curvature of the 
 ■spine.' In right-handed fencers the concavity of the curvature is to the 
 right, in the left-handed to the left. The shoulder of the arm which holds 
 iihe foil is lowered. Dr. Lagrange founds his conclusions upon the exami- 
 nation of twenty experienced fencers. The tendencies to deformity are very 
 unequally marked. In some the deviations are quite trivial, in others they 
 are pronounced. This evidence is of considerable importance in forming an 
 estimate of the value of fencing as a muscular exercise, especially to those 
 who are under twenty or twenty-five years of age. 
 
 Boxing, 
 
 if carried out under proper conditions, and especially if practised in the open 
 air, is an admirable exercise for lads and young men. Unfortunately the 
 surroundings of a boxing saloon are not always the best adapted for the 
 education of youth, and the so-called ' professors ' of the art are not usually 
 the best associates for plastic-minded lads. 
 
 The exercise itself, however, is admirable. It brings into play prac- 
 tically all the muscles of the body. A vigorous blow is struck as much 
 from the leg and trunk as from the arm. It has been well said that a good 
 and powerful blow starts from the foot. Mitchell, in the monograph upon 
 boxing in the Badminton Library series, says : ' It may seem paradoxical 
 and provoke a smile to say that the first necessity for using the fists pro- 
 perly is to understand the use of the feet.' The boxer needs to be agile, 
 
 pp2 
 
580 HYGIENE 
 
 to be able to use his legs, to be quick with the movements of his head and 
 his trunk. Boxing, moreover, gives excellent use to the left arm, which 
 is apt to be neglected in many other forms of exercise. It calls for rapidity 
 of movement, ready decision, good judgment, and a control of the temper. It 
 promotes the ch-culation, and in a vigorous round the boxer is very soon 
 rendered breathless. 
 
 The atmosphere in a boxing saloon is not always so well supplied with 
 fresh air as it might be. 
 
 Boating 
 
 It may perhaps be said, without fear of contradiction, that boating pre- 
 sents one of the most complete, uniform, and delectable forms of exercise. 
 It is an exercise which is especially associated with the English, and it is in 
 England that the sport is the most highly elaborated and the most widely 
 practised. Boats of one form or another appear among the environment of 
 such primitive peoples as have lived by the sea or about the banks of navi- 
 gable rivers ; but the development of boating as a fine art, the perfecting of 
 this picturesque and enjoyable mode of locomotion, rests with the sturdy 
 and watcr-lovuig sons of England. Surrounded on all sides by the sea,, 
 and living in a land permeated by many rivers, it is not unnatural that an 
 Enghsh lad should take to the water like a duck, and should feel that 
 enthusiastic love for the sea which appears to be almost an hereditary taste, 
 and which is possibly not a little influenced by the great naval records of 
 the country. 
 
 For every professional rowing man in our midst there will be hundreds 
 of amateurs who are by no means a discredit to the sport. At all public 
 schools situated within reach of water, rowhig is a prominent feature of school 
 life. At the two great Universities of Oxford and Cambridge boating occu- 
 pies a position which the less robust section of the public are apt to consider 
 a little too conspicuous. The whole length of the Thames from Oxford to 
 London durmg the few months of the English summer is alive with boats, 
 and is animated by rowers of all classes and all ages. Among this busy, sun- 
 browned, and white-flannelled community may be seen old men and maidens^ 
 as well as young men and children. 
 
 The sheer delight given by the mere circumstances of boating requires 
 little comment. It needs merely the conception of a stretch of fair water, the 
 early morning of a day in the English summer, a light outrigger, and a pair of 
 sculls to every point of which the sculler has fitted his muscles. There is the 
 crisp grasp of the water, the swish of the blades, the shooting of the tiny 
 craft across the polished river, the whistling of the wind about the rower's 
 head, and the rippling of the water as the prow runs through the magic 
 lights and shadows which are thrown from the bank. 
 
 Boating offers, moreover, one of the most charming forms of touring. A 
 man may spend many summer holidays in a boat or in a canoe before he has 
 exhausted the beauties of the rivers of Great Britain. 
 
 Across the Channel the system of canals on the Continent offers an un- 
 paralleled opportunity for a journey such as has been described — as no other 
 pen could have described it — by R. Louis Stevenson in his ' Inland Voyage.' 
 
 It is greatly to the credit of England that her waterways are more 
 densely peopled with boating folk than are the waters of any other country of 
 hke population. 
 
 With regard to boats, it is only necessary to say that for racing the keel- 
 less boat is employed. Its bottom is round and smooth. Such a boat is 
 extremely unsteady and requires all the skill of a novice to ' sit it.' The 
 
PHYSICAL EDUCATION 581 
 
 iDGginner may find no difficulty in propelling such a boat, but he will expe- 
 Tience considerable difficulty in keeping in it. The sculler in a racing boat 
 lias, like the bicyclist, first to balance himself and then to move. 
 
 The outrigger was introduced in 1842 by Clasper. 
 
 This very simple improvement enables a greatly increased length and 
 greater advantage in leverage to be given to the oars, while at the same 
 time it allows the dimensions of the racing craft, and especially of the beam, 
 to be much reduced. The ordinary length of an inrigged pair-oared pleasure 
 boat or gig is 22 ft. and the beam 3 ft. 9 in. The length of a racing sculling 
 boat will be about 31 ft. and the beam about 11 inches. 
 
 Another noteworthy improvement — the invention of an American — was the 
 sliding seat, which was first used in England in a race in 1871. The general 
 features of the sliding seat will be sufficiently familiar. Its precise mechani- 
 cal value has been very ably described by the Eev. E. Warre, of Eton, in the 
 following words : — 
 
 ' Mechanically speaking, in rowing the water is the fulcrum, the boat is 
 the weight to be moved, the oar is the lever, and the man applies the power. 
 The leverage is most powerful when applied at right angles to the weight ; 
 tout in the problem to be solved, owing to the motion of the oar itself through 
 the water and the motion of the boat through the water, the moment at 
 which this can be the case is extremely transient. Could any satisfactory 
 mechanism be devised by which the weight — that is, the thowl against which 
 he rows — could be moved forward during the stroke, while the oarsman was 
 still in the position to exert his full power against it, we might expect a great 
 increase of speed. This, however, is a structural problem not yet solved. But 
 the sliding seat in some measure answers the purpose by enabling the oars- 
 man or sculler to continue his physical effort by the straightening of his 
 legs in such a way that his power and his weight, which are most available 
 ^t the beginning of the stroke, are operating in the water for a longer period 
 ■during each stroke than could be if he were on a fixed seat. The gain is 
 much less than that of a moving rowlock would be because, owing to the 
 rising of the knees when the slider is forward, a man cannot obtain a much 
 greater reach forward than he could on a fixed seat. It is when the body 
 has moved up towards the perpendicular, and the water has already been got 
 hold of, that the advantage of the sliding seat begins. As the slider moves 
 back, the uncoiling of the human spring, which is imbedded in the stretcher, 
 can go on with undiminished force for the distance of the slide, when the 
 pressure of the legs ceases and the weight of the body is again entirely thrown 
 on the seat. The mechanical advantage is here mostly after the rowlock, 
 and that is the least valuable part of the stroke, especially in a light boat. 
 Still the gain is considerable, as it enables more weight and more strength 
 to be applied to the oar for a longer portion of the stroke. 
 
 'Further, there has been for grown men a physical gain in that the 
 increased length of stroke enables the same pace to be attained with fewer 
 strokes per minute. The pace of the inferior or mediocre crews accordingly 
 has been improved. Moreover, the effort of springing the body forward to 
 its fullest reach, which on the fixed seat was necessary, is now greatly reduced 
 by the mechanism of the slide, and consequently the exertion to heart and 
 lungs is much less. This is a gain to those who, by reason of age and figure, 
 .are not so hthe and active as in boyhood, but it has been a loss to pubhc 
 school crews, who could make up formerly by pace of stroke and agihty 
 for their inferiority in strength to men.' ^ 
 
 ' Health Exhibition Handhoohs, vol. x. 
 
582 HYGIENE 
 
 The sliding seat is estimated to give a gain of about 18 in. in the length 
 of the stroke upon a 9 in. slide. 
 
 'The shding seat,' writes Mr, Woodgate, in the Badminton Library- 
 volume on Boating, * decidedly relieves the abdominal muscles and respi- 
 ratory organs during the recovery. The point wherein a tiring oarsman first 
 gives way is in his recovery, because of the relative weakness of the muscles 
 which conduct that portion of the action of the stroke. It therefore is obvious 
 that any contrivance wliich can enable a man to recover with less exertion 
 to himself will enable him to do more work in the stroke over the whole 
 course, and still more so if the very contrivance which aids recovery also 
 gives extra power to the stroke.' 
 
 The increase in speed has not been so great as might have been imagined.. 
 
 Bowing and Sculling 
 
 Eowing, it is needless to say, involves the pulling of one oar with both- 
 hands, and sculhng the pulhng of a pair of sculls, employing, of course, one 
 hand to each. 
 
 The details of the stroke in rowing should be weU understood in order 
 that the muscular features of the act might be recognised and the qualities 
 of a good stroke appreciated. The following description of the rowing' 
 stroke by the Eev. E. Warre is precise and lucid, and can hardly be improved 
 upon : — 
 
 ' The moment the oar touches the body drop the hands smartly straight 
 down, then turn the wrists sharply and at once shoot out the hands in a 
 straight line to the front, inclining the body forward from the thigh joints 
 and simultaneously bring up the slider, regulating the time by the swmg 
 forward of the body according to the stroke. Let the chest and stomach come 
 well forward, the shoulders be kept back, the inside arm be straightened, the 
 inside wrist a little raised, the oar grasped in the hands, but not pressed 
 upon more than is necessary to maintain the blade in ' its proper straight 
 line as it goes back, the head kept up, the eyes fixed on the outside shoulder 
 of the man before you. As the body and arms come forward to their full 
 extent, the wi-ists having been quickly turned, the hands must be raised 
 sharply, and the blade of the oar brought to its full depth at once. At that 
 moment, without the loss of a thousandth part of a secand, the whole weight 
 of the body must be thrown on to the oar and the stretcher by the body- 
 springing back, so that the oar may catch hold of the water sharply and 
 be driven through it by a force unwavering and uniform. As soon as the 
 oar has got hold of the water, and the beginning of the stroke has been 
 effected as described, flatten the knees, and so, using the muscles of the legs, 
 keep up the pressure of the beginning uniform through the backward motion 
 of the body. Let the arms be rigid at the beginning of the stroke. When 
 the body reaches the perpendicular, let the elbows be bent and dropped 
 close past the sides to the rear — the shoulders dropping and disclosing the 
 chest to the front, the back, if anything, curved inwards rather than outwards, 
 but not strained in any way. The body, in fact, should assume a natural 
 upright sitting posture, with the shoulders well thrown back. In this position 
 the oar should come to it and the feather commence.' 
 
 Among the particulars to be noted in the stroke are the following. The 
 back should be set stiff and must not yield as the stroke is pulled. It 
 should be straight while the chest comes well forward. The whole 
 trunk should swing as a rigid column from the hips, moA-ing forwards and 
 backwards. The main pull of the arms is from the shoulders. The biceps- 
 
PHYSICAL EDUCATION 583 
 
 should not do the work and the elbows must be kept well to the side. If 
 this latter point be insisted upon the stroke can scarcely be rowed home by 
 the arm muscles. When an oarsman is becoming ' pumped ' it is in the 
 recovery that he feels the strain. He fails to shoot the hands forwards from 
 the chest the moment after they touch that point, and he becomes sluggish 
 in reaching forward to take a fresh hold of the water. 
 
 Sculling is in all essential particulars identical with rowing, so far as the 
 muscular movements are concerned. It involves, however, more precision, 
 more skill, more practice. The sculler has to acquire the art of balancing 
 himself, and a failure to ever do this well leads often to a fixed bad style, 
 which no practice appears to remove. 
 
 The remarks already made apply to rowing and to sculling in its highest 
 developments, but in all essentials they apply to the ordinary pleasure boat. 
 In such a boat there is no need of great speed, there is no sliding seat to 
 embarrass an already complex movement. The boat is steady enough, and 
 the oarsman can devote all his energies to the pulling. 
 
 It is much to be regretted that many boating men and women are content 
 simply to pull the boat along. They care nothing about the order of their 
 going, they are perfectly indifferent as to style, and are content for the rest 
 of their days to row badly. To row correctly is to row with ease. The better 
 the style, the easier the movement and the better the pace. The better the 
 style, moreover, the more complete and perfect is the exercise. Bad rowing 
 is often bad exercise, and to row in the atrocious manner with which some 
 holiday makers have made us familiar is to indulge in a pursuit of very 
 doubtful utility. 
 
 As an exercise, sculling may be considered to be better than rowing. To 
 all ordinary individuals boating should imply a knowledge of sculling, and no 
 person should be content with the capacity to pull one oar. 
 
 Sculling involves a more even employment of all the muscles of the body ; 
 one side of the body is not more extensively employed than is the other ; 
 there is no disposition to rotate or ' screw ' the back or to pull, as it were, 
 from one side. In sculling, the muscles of the two sides of the body are 
 equally employed and the exercise has the great merit of being perfectly 
 symmetrical. 
 
 The Muscles Involved 
 
 Let us imagine a man sculling in an ordinary gig with a fixed seat. He 
 takes a good grasp of the sculls, using fully the muscles of the hand and of 
 the flexor side of the forearm. He throws the hands forwards to take the 
 stroke, using the extensor muscles of the arm, the pectorals, the serratus 
 magnus and such scapular muscles as draw the upper limb forwards. The 
 body is at the same time thrown forwards by the contraction of the abdominal 
 muscles, the psoas and iliacus, and some of the anterior femoral muscles. 
 The whole back is kept stiff, and the trunk swings forwards from the hip 
 joints only. The sculls are now drawn through the water, the muscles of the 
 upper arm contract, together with the posterior scapular muscles and the 
 latissimus dorsi. The main agent, however, in effecting the stroke is provided 
 by the great mass of the extensor muscles of the back and by the powerful 
 glutei muscles. The man rows with his back, not with his arms. In pulling he 
 presses the feet against the stretcher, contracting nearly all the muscles of the 
 lower limb. In feathering he calls into action the extensors of the forearm. 
 
 Inasmuch as the head is kept erect and the chest well thrown forward, 
 it will be seen that sculling and rowing do actually engage all the main 
 muscles of the body. 
 
584 HYGIENE 
 
 If a sliding seat be employed, then the exercise is still more complete and 
 uniform, for the muscles of the lower limb are used to a still greater extent 
 in drawing the body forwards and in shooting it back. Still the main strain 
 in rowing and sculling falls upon the muscles of the back and hip. 
 
 The mechanics of sculling can be readily studied in Muybridge's ingenious 
 photographs, and reference may be made to the description in Keating's 
 ' Cyclopaxlia ' (vol. iv., photo, iv.). 
 
 The idea, often expressed, that boating involves the use of the arms only 
 is even more ridiculous than the equally common assertion that bicycling in- 
 volves the use of the legs only. A muscular man going into hard training 
 for rowing will find that his biceps muscles will actually diminish in size. 
 
 The bad oarsman rows or sculls with his biceps. Such an individual is 
 often to be seen in the London parks. He sits with his back limp and 
 arched, and very probably with his legs tucked away under the thwart. He 
 leans forwards to take the stroke, grasps the water, and pulls the sculls 
 through simply by the action of the muscles of the upper limb and mainly by 
 the biceps. He does not extend the trunk beyond the perpendicular, and the 
 manner in which he projects his elbows has been caricatured often enough. 
 The movements he executes are not those of the oarsman, and, although the 
 half-hour's pull may be better than no exercise at all, it tends to make the 
 individual round-shouldered and clumsy, and to develop the muscles of his 
 arms to the sacrifice of all the others. 
 
 The Adaptabilities of Boating 
 
 Boating properly carried out must remain one of the most perfect forms of 
 muscular exercise we possess. The degree of muscular effort involved can 
 be regulated to any degree, and a girl of eleven may scull with as much style 
 as an athlete of twenty. 
 
 Boating is an exercise which does not cause breathlessness. An elderly 
 man can pull a boat day after day on a long river tour without difficulty, 
 provided the pace be moderate, when he would be utterly out of breath on 
 ascending a hill or even a great flight of stairs. It can be indulged in by 
 individuals with weak hearts and weak lungs, provided, of course, that the 
 pace is strictly limited. 
 
 Boating is not suited for the subjects of hernia nor for those with a disposi- 
 tion to hernia. The posture assumed in leaning forwards to take the stroke and 
 the contraction of the abdominal muscles at the same time favour a hernial 
 protrusion. 
 
 Boating, however, tends to develop and to strengthen the abdominal 
 muscles and to lessen the size and improve the tone of the pendulous abdo- 
 men not uncommon after middle life. 
 
 Eowing and sculling are admirable exercises for girls and women. 
 Ladies should row without corsets, or with corsets of the slenderest possible 
 make. Perhaps no exercise is better suited to remedy the muscular defects 
 which are conspicuous in the gentler sex. It expands the chest, strengthens 
 the back, and gives tone to the muscles of the abdomen. 
 
 Boating should be recommended with certain precautions, and of course 
 in properly selected cases to the subjects of lateral curvature of the spine, 
 especially to those who exhibit the deformity in its early condition. 
 
 Such individuals should scull, not row. All those who take to boating 
 should first learn to swim. Boys may begin to learn to row at six and girls at 
 eight. It is a matter of the utmost importance that the learner be well taught. 
 
 It is well to begin in a light half-outrigged boat which will seat two, the 
 
PHYSICAL EDUCATION 585 
 
 teacher and the pupil. The water should be smooth. The pupil should 
 begin by pulling one scull only, rowing for equal periods upon the right and 
 the left side. He will in this way learn the rough details of the stroke and 
 the rhythm of the movement. He should from the first be made to keep time. 
 
 The exercise with one scull should be brief, and the sooner the pupil 
 takes to both sculls the better. There is usually much difficulty with the 
 left hand. 
 
 As soon as the pupil can scull moderately well he should row behind a 
 good oarsman, and in this way he will pick up the swing of the movement 
 and the proper points of the stroke. 
 
 Sea Boioing is inferior to river rowing as an exercise : the boat is heavy, 
 the gunwale is high out of the water, the stroke is short, and the movement 
 is not susceptible of the finish possible in a river boat. 
 
 Those who have rowed much on the sea will probably never row well on 
 the river. The exercise involves more muscular exertion, which is, however, 
 of a rougher, more clumsy and unfinished kind. To row a sea boat the 
 individual must be strong. Sea rowing is not well adapted for children or 
 for those who are muscularly feeble ; and, while as an exercise it has admirable 
 points, it should be borne in mind that on fresh water alone is the pursuit of 
 boating capable of assuming its most perfect form. 
 
 Canoeing 
 
 For the purpose of the present paper canoes may be considered to belong 
 to two classes — the Eob Eoy canoe and the Canadian. 
 
 In the former the canoeist sits amidships with his lower limbs extended 
 straight upon the floor of the craft. The paddle is of considerable length, 
 and has a blade at either end. The canoeist holds it about breast high, and 
 drives first one blade through the water and then the other. His back is 
 supported by a rest. 
 
 In this form of canoeing the muscular exertion involved is limited to the 
 muscles of the arms and shoulders, including the pectorals, trapezius, 
 serratus magnus, and latissimus dorsi. The muscles of the neck and 
 upper part of the back are concerned, but the body below the thorax is 
 practically motionless. The exercise, therefore, is one of limited muscular 
 applicability. 
 
 The exercise is good for those who wish to develop the arms or who fi'om 
 some deformity or defect are unable to use the lower limbs. It is not an 
 exercise to be recommended to those who aim at developing the whole 
 muscular system or who are the subjects of any spinal weakness. 
 
 In the Canadian canoe as adapted for use in England the canoeist sits 
 at the extreme stern, either on the floor or upon a seat nearly flush with the 
 gunwale, and with his feet on a stretcher. He has a short paddle with a 
 single blade. He paddles upon one side of the craft only and steers by 
 manipulating the blade at the completion of each stroke. In all but the 
 smallest form of Canadian canoe a second seat is provided close to the prow 
 for a second paddle. The fore paddle may be shorter, and is worked at a 
 diminished advantage, and the steering of the craft must still remain with 
 the paddle in the stern. 
 
 The Canadian canoe involves a much more complete form of exercise 
 than does the Eob Eoy canoe. The canoeist has no support for his back. 
 He must keep himself erect by muscular effort. In effecting the stroke he 
 employs, not only the muscles of the upper limb, but also the muscles of the 
 trunk. The whole body undergoes some rotation in the vertical axis at each 
 stroke. After long paddling, a sense of exhaustion is felt in the back 'and 
 
58G HYGIENE 
 
 about the loins, but not in the arms. The canoeist has also to balance him- 
 self, and as the Canadian canoe is carvel-built and keelless this involves 
 some extra muscular expenditure. The after paddler can make consider- 
 able use of his legs, moreover ; a help which is, to a great extent, denied to 
 the paddler in the bow of the canoe. The canoeist should change his side 
 fi'om time to time — in other words, should not paddle for too long a time at 
 a stretch upon one side. Paddling upon one side tends to produce much 
 lateral bending of the vertebral column. 
 
 This exercise is not well adapted for the weakly, nor for those who have 
 weak backs and a disposition to lateral curvature. For the robust it is ad- 
 mirable, and forms a very pleasant variation to rowing or sculling. 
 
 A voyage in a canoe usually involves exercise of the most varied kind : 
 there are hard paddling against a stream, nervous steering down a rapid, the 
 dragging of the craft over shallows and past milldams, and the very arduous 
 task of making a way through thick rushes and weeds. 
 
 Cycling 
 
 The history of athletic sports provides probably no more remarkable 
 feature than is afforded by the introduction and development of cychng. 
 Twenty years ago the bicycle was unknown in this comitry. Even fifteen 
 years ago riders upon bicycles were regarded as little other than acrobats 
 and mountebanks. Within so short a period this form of athletic exercise 
 has developed with almost incredible rapidity and with phenomenal vigour. 
 Cyclists are now to be counted in tens of thousands, the sport has been taken 
 up by individuals of all ages and in all stations of life, and has been enthu- 
 siastically patronised by women as well as by men. 
 
 The history of cycling is very admirably given by Mr. G. Lacy Hillier — 
 himself a well-known rider^n the Badminton volume on ' Cycling.' 
 
 The general features of the cycles now in use must be familiar enough. 
 There are two forms of bicycle, the ' Ordinary ' and the ' Safety.' The 
 Ordinary represents the earher pattern. In this machine the wheel is driven 
 by the direct action of the pedals. The size of the wheel depends upon the 
 height or ' the reach ' of the individual rider. A diameter of 50 inches 
 will represent an average size. With this wheel the rider steers, and upon 
 it he balances himself. In propelling this machine there is no waste of 
 muscular force. The rider is placed directly ' over his work,' or, as it would 
 be expressed with reference to other exercises, ' close to his work.' No power 
 is lost upon cog wheels and chains, and the weight of the body can be 
 admirably utihsed in aiding progression. 
 
 The Safety bicycle represents the machine of the immediate future. The 
 varieties of this cycle are legion, but the form most commonly used is founded 
 upon what is known as ' the Eover ' pattern. 
 
 The Safety bicycle is represented by a machine with the following cha- 
 racters. The two wheels are comparatively small, and are either of equal 
 size or are nearly so. The diameter of each will be about 28 or 30 inches. 
 The front wheel is the steering wheel, and with it the handles are coimected ; 
 its movement, so far as the act of steering is concerned, is effected through 
 a nearly horizontal joint, 'the head.' The hinder wheel is the driving 
 wheel. It is not propelled by the direct action of the pedals. The pedals 
 act upon a small cogged or toothed wheel carrying a chain, and through this 
 chain the movement is communicated to the rear wheel. The rider sits 
 directly over the chain wheel to which the pedals and their cranks are 
 attached, and is therefore placed between the two running wheels of the 
 
PHYSICAL EDUCATION 587 
 
 bicycle. The machine is said to be ' geared.' If the two pulley wheels with 
 which the chain is connected are of equal size the machine is said to be 
 ' level geared.' In such case one complete revolution of the pedal involves 
 one complete revolution of the driving wheel. If the pulley wheels with 
 which the chain is connected are of unequal size, and if the wheel con- 
 nected with the pedal is the larger, the machine is said to be ' geared up.' 
 In such case the pedal revolutions are fewer than the revolutions of the 
 driving wheel. The Safety bicycle is usually ' geared up to 54 ; ' that is to 
 say, the relation between the wheel moving the chain and the wheel moved 
 by it is such that the driving wheel, which has an actual diameter of 28 
 inches, revolves at each complete turn of the pedal through a range of 
 movement equal to that made by one complete revolution of a wheel with 
 a diameter of 54 inches. 
 
 Some tricycles are ' geared down,' by which term is implied the fact 
 that the hinder of the two pulley wheels is the smaller, and therefore more 
 than one revolution of the pedal is required to produce one revolution of the 
 driving wheel. 
 
 In this question of gearing it must be remembered that one factor of the 
 equation, viz. the strength of the rider, is a fixed quantity, and that either 
 speed or power must be sacrificed when the other conditions of the problem 
 are varied. If the machine be geared up, the rider can make fewer revolutions 
 of the pedal than would be required if the gearing were level, but he must 
 employ more force. On the other hand, if the machine be geared down an 
 increased number of movements of the foot is required ; but the amount of 
 force involved is much less. A young man of light weight or an individual 
 of feeble muscular power may prefer to use his legs with greater activity pro- 
 vided he can employ a lesser degree of muscular effort. Such an individual 
 may prefer a cycle geared low. A man of more advanced years, of more than 
 average weight, and of considerable muscular strength, would probably be 
 glad to expend an undue amount of force on each stroke of the foot rather 
 than to feel the necessity of moving his pedals rapidly. Such a rider 
 would select a machine with a higher gearing. 
 
 While a roadster Safety will usually be geared to 54, a racer Safety of the 
 same type may be geared to 63. 
 
 The Humber Eoadster tricycle (' gents' light cripper ') is geared to 57 in 
 the maker's catalogue, the ladies' tricycle of the same pattern to 54, the 
 corresponding racer cripper to 63. 
 
 The weight of a racing Safety may be reduced to 201b. complete. The 
 weight of a racing tricycle (Humber Cripper) is given as 30 lb. A roadster 
 Safety weighs from about 36 to 42 lb. A Eoadster tricycle may scale from 
 45 to 66 lb. 
 
 The tricycle is well represented by the excellent machine known as the 
 Humber Cripper. In this tricycle the front or steering wheel has a diameter 
 of 24 in., the two driving wheels of 30 in. A single chain is employed. The 
 saddle is placed well over the pedals, and the machine in all general features 
 is based upon the mechanical lines of a Safety bicycle. The introduction of 
 the ingenious ball-bearmg joint to cycles of all kinds has reduced the amount 
 of friction in running to a minimum. 
 
 The Safety bicycle if taken against any obstacle sufficient to stop the front 
 wheel merely falls over on its side. The rider's feet are so close to the 
 ground that it needs no very great inclination of the machine to enable him 
 to bring one foot to the ground, and so prevent a fall. 
 
 The term ' Safety ' is well merited. An accident, when it occurs, is 
 probably the fault of the rider alone, and is inexcusable. There are many 
 
588 
 
 HYGIENE 
 
 Avho have ridden these machines for years over some thousands of miles of 
 road, and who have yet never met with what may be termed an accident, or 
 even a nasty fall. 
 
 One disadvantage which has been urged against all cycles is that of 
 vibration. There is no doubt that long-continued vibration communicated 
 to the body is injurious. It is unpleasant, it induces fatigue, and leads to 
 earlier exhaustion of the muscles. 
 
 The effects of vibration are less felt in the young, and upon the bodies of 
 lads under eighteen, who still possess many epiphyseal cartilages, a long- 
 continued vibration may tell but little. But in older individuals, in those 
 Avhose bodies have become more rigid in the process of development, and 
 especially in persons with a sensitive nervous system, vibration has certainly 
 an unfavourable effect. They return from a long ride over rough roads with an 
 imdue sense of fatigue — they feel ' shalvcn,' the back aches, the arm muscles 
 are a little tremulous, and there often follow a headache and a sleepless night. 
 
 Vibration has been to a large extent overcome by the use of ' cushion ' or 
 ' pneumatic ' tyres, or by means of a suspending spring, such as has been intro- 
 duced, with the greatest success, in what is known as the ' Whippet ' bicycle. 
 The Whippet machine may be said to bear the same relation to the usual 
 Safety bicycle which a cart witli springs bears to one without springs. 
 
 The following records will give an idea of the possible speed which can 
 be attained on a cvcle: — 
 
 - 
 
 Bicycle 
 
 Tricycle 
 
 
 h. m. s. 
 
 h. m. s. 
 
 Half-mile 
 
 1 8 
 
 1 17 
 
 One mile . 
 
 2 20 
 
 2 37 
 
 Three miles 
 
 7 40 
 
 8 6 
 
 Ten miles 
 
 26 40 
 
 28 13 
 
 Twenty miles . 
 
 55 
 
 56 40 
 
 Fifty miles 
 
 2 25 26 
 
 2 38 44 
 
 Hundred miles 
 
 5 50 5 
 
 6 9 26 
 
 Cycling as an Exercise 
 
 Bicycling. — A ride upon a bicycle involves not only an admirable muscular 
 exercise, but it involves of necessity exertion in the open air. The exercise is 
 continuous and not intermittent ; it can be regulated to any degree, and can 
 be indulged in equally by the athlete and the weakling. 
 
 He who owns a bicycle has at his command one of the most admirable 
 and certainly one of the least expensive means of travelhng. He is de- 
 pendent solely upon himself, and can without difficulty travel fifty miles a day. 
 No horse could compete in endurance and in long distances with the bicycle 
 rider. 
 
 Cycling has undoubtedly done more than has any other form of physical 
 exercise to improve the bodily condition of the city clerk and the shop assistant. 
 The lad who is pent up in a close office all day has now no difficulty 
 in finding a means for well occupying the summer evening or the few hours 
 at his disposal before the work of the day begins. He has merely to mount 
 his bicycle and in an hour he is ten miles away from the din of city life, and 
 is breathing a clearer and brisker air. He who is an early riser can in the 
 summer months well manage a twenty-mile ride before breakfast. 
 
 Unhke the player of cricket and football or the rowing man, the cyclist is 
 ■dependent upon no one but himself. His means of exercise is always at hand, 
 
PHYSICAL EDUCATION 580 
 
 and lie can occupy a spare half-hour or the entire afternoon with the same 
 amount of preparation. 
 
 The specific features of the exercise of bicychng may best be reviewed by- 
 discussing the objections which have been urged against the sport. 
 
 1. It is said to be dangerous. This objection without doubt applied to the 
 high-wheel bicycle, but it can scarcely be said to be just as regards the more 
 modern machine — the Safety. The rider rides with his feet but a few inches 
 from the ground. If he is falhng he has simply to step off. The machine 
 cannot turn * head over heels,' it can merely fall upon its side. The brakes 
 now applied to these machines are so strong that they can bring the bicycle 
 to a standstill in a moment. 
 
 The most serious accidents have occurred in riding through crowded 
 streets, and unless a rider is perfect at his work, and is as quick as a hare, he 
 is merely foolhardy if he attempts to ride through a very busy thoroughfare. 
 
 Bicycling may be said to be less dangerous than riding on horseback, 
 especially when the distances travelled are taken into account, and to be 
 certainly less risky than skating. 
 
 2. A second objection to the bicycle is that it is a very partial exercise, 
 and that it involves the use of the muscles of the legs only. It may be said 
 at once that the first difficulty of bicycle riding is not the propelling of the 
 machine, but the maintenance of a proper balance. The learner after his 
 half-hour exercise will not complain of aching in his legs, but of aching 
 in his arms and, to a lesser degree, in his back. The beginner is apt to believe 
 that the whole strain of the exercise comes upon the forearms. In other 
 words, the grip of the steering wheel and the easy, immediate, and complete 
 control of that part of the machine are the first principles in bicycle riding. 
 To preserve the upright position many muscular movements are required, 
 and in these practically all the muscles of the trunk are concerned. 
 
 In course of time balancing becomes not only easy but quite automatic ; 
 and while it is true that the upright posture is finally retained with a very 
 modified amount of muscular exertion, still an extensive series of muscles 
 are involved even if the pov^er exerted be slight. 
 
 To sit upright for some hours without any support for the back is not a 
 quite insignificant exercise, and after a long ride the bicyclist finds that he 
 has been doing more with his back than he thought. 
 
 So far as the movements of the legs are concerned, an opinion of bicycling 
 as a muscular exercise should not be formed by observing the riders one 
 often sees in the streets of a great city on Sunday or on the suburban roads 
 on a Bank holiday. 
 
 The ill-taught or inexperienced rider rides from his hips ; he moves his 
 lower limbs like pistons ; his action is extreme ; his ankle is fixed ; his foot 
 and leg move as one. 
 
 Pedalling is, to a great extent, a matter of the ankle-joint. The more the 
 ankle-joint is employed the more is muscular power economised, and the 
 more graceful is the rider's movement. 
 
 While bicycling does certainly involve in the main the muscles of the 
 lower extremities, it at the same time gives excellent employment to the 
 muscles of the upper limb (especially of the forearm) and to the muscles of 
 the trunk. 
 
 Cycling does not tend to develop the chest or exercise the great muscles 
 passing from the trunk to the upper limb, and herein lies the defect of the 
 sport as an exercise. It cannot be recommended as a predominating mode 
 of exercise to a tall, lanky lad with a narrow chest and a stooping back. 
 Such an individual should take to rowmo' and leave the wheel alone. 
 
590 HYGIENE 
 
 3. In the tliirtl place it is said that bicycle riding induces a very per- 
 nicious posture of the body — a posture which has been well caricatured by Du 
 Maurier in the pages of ' Punch.' The posture complained of can be seen any 
 day among those who hire a bicycle now and then for an hour and tear wildly 
 through the streets thereon. The rider is leaning so far forwards as to have 
 his body nearly horizontal. His back is bowed and arched, his elbows stick 
 out like the limbs of a startled cat, his chest is almost upon the handle bar, 
 and his chin is thrust well ahead. 
 
 This attitude is, to some extent, a necessity upon the racing track, and 
 there is no doubt that it is practically essential in riding at the highest pos- 
 sible speed. 
 
 For riding upon the road it is ridiculous and as out of place as the posture 
 of a jockey at the finish of a horserace would be in an individual taking a 
 canter in Eotten Eow. 
 
 This absurd attitude when assumed by riders on the road may be put 
 down in part to sheer ignorance, in part to bad teaching, and in part to a 
 foolish imitation of the racing man. It is unnecessary, inelegant, and dis- 
 tinctly injurious. 
 
 The rider should sit quite upright, with his back straight and with the 
 upper part of the body as still as possible. The head should be erect, the 
 shoulders well thrown back, and the elbows at the sides. He should sit, 
 moreover, well to the back of his saddle, and, as one writer expresses it, ' push 
 out in front, using the saddle to push from.' The handles of the machines 
 are now made so as to render a perfectly erect position possible ; and in 
 ordering a machine it is important that this matter of the handles should 
 be attended to. 
 
 There is no doubt that some riders who have been utterly careless of their 
 attitude have to thank the bicycle for rounded shoulders and a stooping back. 
 
 4. It is said that in cycling injurious pressure is brought to bear upon 
 the perinfeum, and that perinseal abscess, urinary fistula, and other troubles 
 have resulted therefrom. The writer has not been able to find any evidence 
 to support this assertion. 
 
 It is possible that cycling may lead to mischief if practised by a patient 
 ■udth an inflamed urethra ; it is conceivable that it may act injuriously in the 
 subjects of urethral stricture and enlarged prostate. For even this last- 
 named possibihty there is very little scientific support. Among tricycle 
 riders the writer is acquainted with more than one subject of prostatic, hyper- 
 trophy, and by such individuals he has been assured that cychng causes no 
 aggravation of such symptoms as they present. In the advanced stages of 
 prostatic trouble in elderly men, when vesical symptoms are present, cycHng 
 could scarcely be practised. 
 
 In perfectly healthy individuals it may be stated that cycling does not 
 produce an injurious degree of pressure upon the perinteum. 
 
 In the modern saddle a suspended slip of leather is the only part which 
 comes in actual contact with the perinasum. No metal-work can cause direct 
 pressure upon that part. 
 
 Any discomfort about the perineum in riding is probably due either to 
 a form of saddle iU- adapted to the individual rider, or to a bad attitude 
 assumed in riding. 
 
 The habit of stooping forwards, which has been already condemned, brings 
 the perinseum unduly upon the saddle, and for this reason, if for no other, 
 the attitude is to be strongly opposed. 
 
 In riding, the weight of the body rests upon the tuberosities of the ischia. 
 These points alone should bear the pressure. 
 
PHYSICAL EDUCATION 591 
 
 Many bicyclists wear suspensory bandages on the ground that the testes 
 are occasionally pressed between the body and the saddle. Such a pre- 
 caution is unnecessary if the rider will make up his mind to sit his maciiine 
 properly. 
 
 It is needless to say that long- continued pressure upon the tuber ischii 
 may lead to some pain along the long scrotal nerve and may induce an 
 enlargement of the bursa over that process of bone. 
 
 The circumstance is, however, very rare, and is no more likely to occur 
 after cycling than it is after daily riding in a third-class railway carriage. 
 
 5. Cycling is accused of producing varicose veins in the leg, and hernia. 
 The case of the first-named affection is considered elsewhere, and need not 
 be again dealt with. 
 
 With regard to hernia there is little to add to what has been already said, 
 except to point out one fact. It is true that in easy riding the abdominal 
 muscles are but little used, and that, therefore, httle pressure is brought to 
 bear upon the abdominal viscera. 
 
 Indeed, in ordinary riding the abdominal muscles have singulary little to 
 ■do. This circumstance may appear to render bicycling a suitable exercise 
 for those who are disposed to hernia. It must, however, be noted, on 
 the other side, that the attitude of the rider tends to so relax the tissues 
 about the hernial orifices as to render the circumstances favourable for the 
 ■descent of a hernia. "When the rider ' puts on pace ' in racing or in avoid- 
 ing an obstacle he leans forwards, throws his abdominal muscles into action, 
 and places himself in a condition certainly favourable for the formation of a 
 rupture. In ' mounting ' also a sudden and pronounced contraction of the 
 belly muscles is called for, and that, too, while the individual's body is 
 flexed. 
 
 It may be said, therefore, that bicycle riding should be avoided by those 
 who have weak inguinal regions or a disposition to hernia, and that it should 
 not be practised by the actually ruptured. 
 
 Bicycling is well suited for the young, nimble, and active ; it is, however, 
 not ill-adapted to the middle-aged and to those who have lost the elasticity 
 of youth. A man of forty, weighing 13 or even 14 stone, may take to 
 bicychng as an exercise, may attain considerable proficiency as a rider, and 
 may derive unmixed benefit from the pursuit. He needs be nimble enough 
 to mount and to dismount quickly, but this involves little more agility than 
 is required to enter or to leave an omnibus while in motion. Bicychng is 
 not adapted for men past middle life, and there are very few riders who may 
 be classed as old men. 
 
 The exercise is admirable for all who require development in the lower 
 ■extremities and who complain of being 'weak in the loins.' Those who 
 are disposed to phthisis or who desire to develop their lung capacity should 
 take up some other exercise than bicycling. It is not perhaps quite the 
 exercise for the timid and nervous, and it should not be adopted by the 
 subjects of urethral or prostatic disease, of hernia, of varicose veins, or of 
 varicocele. 
 
 The exercise appears to have a very beneficial effect in reheving chronic 
 constipation, and is adopted with advantage by those who are the subjects 
 of dyspepsia, haemorrhoids, and functional disorders of the liver. 
 
 As in other forms of exercise, racing and the breaking of records should 
 be left to the young, well-trained, strong, and athletic, and the acquiring of 
 tricks in riding to the acrobat, who has to live by his eccentricities. The 
 ordinary rider when touring should satisfy himself with a pace of not more 
 than ten miles an hour, and a distance not exceeding fifty miles in the day. 
 
592 HYGIENE 
 
 The bicyclist should be well equipped, should Avear well-cut or, better still, 
 well-woven breeches, should be clad entirely in wool, and should burden 
 himself with as Httle luggage as possible. He should avoid tight-fitting shoes, 
 stiff collars, braided uniforms, gauntlets, rubber-soled shoes, and waterproof 
 suits. The only waterproof worn should take the form of a loose cape. The 
 best shoes are thin leather walking shoes. 
 
 Tricycling. — In tricycling the muscles of the lower extremities are almost 
 the only ones involved. No balance has to be maintained, and the steering 
 is accomplished with a very small amount of muscular exertion. The rider 
 has to maintain the body erect, and must thus employ the muscles of the 
 trunk. As an exercise, tricycling is undoubtedly inferior to bicycling. The 
 machine is, moreover, comparatively large and cumbrous, and in a small 
 London house is perhaps with difficulty disposed of. It cannot be so well 
 conveyed from place to place, and when on a tour the rider must always 
 seek a shelter for his machine. The small size of the bicycle and the 
 convenient manner in which it can be disposed of are among its greatest 
 advantages. 
 
 The tricycle rider must keep to main or principal roads. The bicyclist 
 can take advantage of a footpath. The machine makes three tracks, and 
 upon an xmeven or frozen road with sharp ruts the tricycle has very decided 
 disadvantages over the bicycle. 
 
 While in touring the bicyclist can make ten miles an hour, the tricycle 
 rider "udll have to content himself with eight. On the other hand, the advan- 
 tages of the tricycle are the following. The machine is very easy to ride, 
 and can be ridden at once and without any teaching. No balancing is re- 
 quired. The machine can be driven with less muscular exertion, and by 
 altering the gearing a machine can be adapted to almost every grade of 
 muscular capacity. The tricycle can be ridden by the old, the nervous, the 
 moderately feeble, the lame. It can be ridden by ladies and young girls. 
 At the same time, with an athletic rider a great speed can be attained on the 
 machine and enormous distances covered. 
 
 Three great and very decided advantages of the tricycle are these : the 
 rider can stop the machine, and can rest and enjoy the scenery, without dis- 
 mounting ; he can ride without taking very minute note of the road ; he can 
 carry a considerable quantity of luggage. 
 
 Tricychng is a most admirable exercise for those past middle life. They 
 can take their exercise without fear and without trouble, and can moderate 
 then- exertions to any degree. It can be made a violent exercise or a very 
 gentle one. It throws no great strain upon the heart or limgs. It appears 
 to have a good effect upon dyspeptics and the subjects of chronic constipa- 
 tion. It can be indulged in within limits by the subjects of hernia. It in- 
 volves all the advantages attendmg exercise in the open. 
 
 Cycling for Ladies and Girls 
 
 Tricycling is extensively and enthusiastically adopted by many ladies 
 and young girls. Many have attained considerable proficiency at the sport. 
 The luxury of a tandem ride appears to be keenly appreciated : the freedom 
 the lady tricyclist enjoys, and the wide tracks of coimtry she can cover in 
 company with her brother, husband, or other friend are strong attractions for 
 the vigorously inclined. 
 
 It is doubtful if tricychng can be declared to be a good or suitable 
 exercise for yoimg women and young girls. 
 
 It is not a severe exercise, it is true ; and, indeed, the amount of muscular 
 
PHYSICAL EDUCATION 593 
 
 exertion demanded can be very precisely regulated. Many ladies are em- 
 phatic in their advocacy of the claims of tricycling to be considered a very 
 suitable, very beneficial, and quite harmless exercise for females. 
 
 It must be remembered, however, that what applies to one woman may not 
 apply to another, and that arguments applicable to the middle-aged may not 
 be equally suited to the young. 
 
 The precise evidence which is required to decide the question of the 
 value of tricycling for women and girls is a little difficult to obtain and to 
 formulate. 
 
 These points may be drawn attention to. 
 
 It is a question whether an exercise involving extensive use of the lower 
 limbs and of the muscles about the pelvis is an unmixed good during the 
 years of active uterine life. 
 
 During the menstrual period it may be assumed that the exercise would, 
 for many reasons, be regarded as most undesirable ; and there may possibly 
 be some truth in the loose assertion that menstrual irregularities have been 
 developed by tricycling. There is a real difficulty in the matter of the 
 saddle. The modern ladies' saddle is a great improvement upon the older 
 pattern, but the writer knows of no saddle which can be assumed to entirely 
 do away with the possibility of pressure upon the pudendum. 
 
 Individuals have complained of much chafing in the pudendal region 
 as a result of riding, and, without entering into further details, the question 
 may be asked whether in young girls or in young women an exercise is good 
 which may involve considerable pressure and friction in the pudendal region. 
 The very detailed objections which have been allowed to apply to the use of 
 treadle sewing m.achines by factory girls would appear to apply to the riding 
 of a tricycle. 
 
 My personal opinion would take the form of suggesting that there are 
 better exercises for the gentler sex than tricycling provides, that the exercise 
 should not be undertaken by young girls and young women, but that it may 
 be open to those who are married or middle-aged. I am aware of one or two 
 instances in which ladies have abandoned tricycling after a few months' en 
 thusiastic pursuit of the exercise without affording a more definite excuse 
 than that 'it did not agree with them.' That tricycling is not the exercise 
 best suited for a girl about puberty or a yoixng immarried woman I am 
 convinced, and one cannot help noticing that the most enthusiastic, most 
 successful, and most persistent lady riders are no longer young. 
 
 Bicycle riding for ladies and girls may be condemned for the same reasons 
 which have been mentioned in connection with tricycling. Very ingenious 
 Safety Bicycles for ladies have been designed, but it is evident that— with the 
 present shape of saddle at least — they cannot be ridden without producing 
 pressure and friction in the pudendal region. The mounting and dismount- 
 ing is difficult : although it can be performed with perfect decency, the learn- 
 ing to ride involves greater pains, and the dress distinctly adds to whatever 
 dangers may attend the machine. 
 
 There are many very admirable, harmless, and delightful exercises open 
 to the tender sex, but among these cychng, and more especially bicyclmg, 
 need not be included. 
 
 Gymnastics and Calisthenics 
 
 These terms have been, and are, employed in so many senses that they 
 scarcely admit of any precise definition, and certainly of no definition w^hicb 
 would meet with general acceptance. 
 
 VOL. I. Q Q 
 
594 HYGIENE 
 
 The terra 'gymnastics' is usually considered to ap^ly to a series of exercises 
 of a somewhat severe or advanced character, and especially to such as involve 
 the use of apparatus. The term ' calisthenics ' is usually associated with a 
 milder form of systematic exercises, with ' free movements,' with exercises 
 which involve no apparatus, with the simpler forms of drilling, and the like. 
 The definitions of the words given in the ' Century Dictionary ' are convenient 
 ones. ' Calisthenics : The art or practice of exercising the muscles for the 
 purpose of gaining health, strength, or grace of form and movement ; a kind 
 of light gymnastics.' ' Gymnastics : The art of performing athletic exercises.' 
 
 The first expression which presents itself in the consideration of gym- 
 nastic exercises or the teaching of calisthenics is the unfortunate term 
 * system.' The question asked of any mstructor is ' what system does he 
 teach ? ' and of any scheme of exercises, ' what system does it follow ? * Con- 
 siderable discussions have ensued upon the question as to which system of 
 gymnastics is the best ; and while at one centre of physical education faith is 
 fixed upon one system, an opposite belief holds sway at another. 
 
 When the details of opposed systems are considered, and the claims of 
 rival schools are weighed, no little confusion arises. The impartial observer 
 feels that he must seek for some great fundamental characteristics whereby 
 to separate one method from another. He finds that original systems have 
 been modified, reconstructed, added to, and even blended with methods 
 from other sources. He observes that the conception one instructor of 
 gymnastics has formed of a system of training difi'ers materially from the 
 interpretation another teacher has adopted of the very same system. Several 
 of the more modern works upon gymnastics form a mere olla podrida, a 
 mixture of this system and of that, with modifications introduced by the 
 author and such emendations as obscure all means of classification. 
 
 I have myself witnessed a ' display ' advertised as a demonstration of the 
 Swedish system of gymnastics, in which musical drill, the use of bar-bells 
 and dumb-bells, were the main features, and in which none of the familiar 
 characteristics of the Swedish system were notable. 
 
 As a matter of fact, the terms ' Swedish system,' ' Swedish gymnastics,' 
 and ' Ling's method ' are used in so indiscriminate a manner, that the 
 expressions have in the mouths of many become to be synonymous with any 
 form of free movements or any species of gymnastic training which is not 
 violent or which does not involve fixed apparatus. 
 
 One soon has to conclude that no one system is ^;cr sc complete and all- 
 sufficient, that no one can lay claim to international adoption, that evil may 
 result from a blind adhesion to one particular method, and that considerable 
 allowance has to be made for nationality, physical condition, and physical tastes. 
 
 While this is true it must also be allowed that if a certain system be 
 advocated and professed it should be maintained in its entirety so long as 
 its distinctive title is adhered to and employed. 
 
 So far as the present purpose of this article is concerned, it may be said 
 that there are three methods of gymnastic exercise which for purposes of 
 convenience may be here set forth. It must not for a moment be supposed 
 that such a classification is in any way complete, nor is it historically precise, 
 nor perhaps even just. The systems alluded to are — 1, the English ; 2, the 
 German ; and 3, the Swedish. 
 
 1. By the English system is understood a method of physical training 
 by means of athletic exercises and outdoor sports. This system is considered 
 to include marching, running, both long distance runnmg and sprint running, 
 leaping, swimming, &c., trials of strength and endurance, and the usual out- 
 door sports, such as cricket, football, and rowing. 
 
PHYSICAL EDUCATION 595 
 
 This is the sense in which most foreign writers describe the Enghsh 
 system. The definition is not very liberal, but it is very convenient. It is 
 true of physical training in England many years ago, but of course does not 
 profess to represent such training as is at present carried out. 
 
 It is needless to criticise what is termed the English system. The value 
 of athletic sports and outdoor games is recognised and is appreciated in no 
 country so keenly as in England. 
 
 As a method of training, it is obviously crude, unscientific, incomplete, 
 and of restricted application. It is a pleasant training for lusty boys and 
 vigorous men, but it is perfectly clear that it can lay no claim to be con- 
 sidered as a precise and orthodox system. 
 
 2. The German system may be spoken of as being assimilative. The 
 German writers and teachers have adopted and embodied whatever they 
 found good in the practices of other peoples in the matter of physical educa- 
 tion. No system is more liberal, more extensive, more catholic. As Mr. 
 Metzner well says in his account of the German system of gymnastics 
 (Physical Training Conference, Boston, 1889), 'the German system does 
 not claim to have any special exercise of its own, or to be the sole proprietor 
 oi any that no other system may also produce.' The system has been slowly 
 built up during nearly a century, and has shown as a main characteristic 
 the power of intelligent assimilation and the ready appreciation and develop- 
 ment of what has appeared good in physical training. 
 
 The German system embraces all the different branches of gymnastics, 
 ifree movements, mass exercises in every form, with wands, dumb-bells, flags, 
 bar-bells, &c., figure marchmg, trot marching, the use of a most varied and 
 extensive series of fixed apparatus, the use of clubs and all forms of hand 
 apparatus, and the encouragement of such exercises as come under the 
 heading of outdoor sports. 
 
 It aims at general physical culture and does not encourage the develop- 
 ment of especial powers or especial abilities ; it encourages exercises in 
 classes (mass exercises) and endeavours to infuse interest and amusement in 
 its instructions ; it aims at being complete and of being capable of adaptation 
 by individuals of all ages and of very varied physical ability ; it encourages 
 a gradual and progressive form of instruction, the pupil commencing with the 
 simplest exercises and proceeding with the more difficult and arduous only 
 when the more rudimentary have been fully mastered. 
 
 A description of the exercises carried out under the German system 
 would require a treatise of considerable length, (a) The free exercises imply 
 various movements of the hmbs and trunk carried out without apparatus. 
 They include manifold movements of the arms and legs, bending and rotating 
 of the body in various directions, and the assuming of a number of attitudes 
 and postures. 
 
 By these free movements it is considered that every muscle is exercised ; 
 the exercises are simple, gentle, and are especially adapted for children, 
 although they should form the preliminary course in any scheme of physical 
 training. They are repeated a great number of times and are effected 
 symmetrically so that each side of the body may be equally developed. They 
 are so arranged as to be progressive, and every attempt should be made to 
 render them complete. These exercises are obviously best conducted in classes, 
 and many are very conveniently carried out to music, as the German system 
 allows. They are popular and interesting. They tend not only to develop 
 the muscles but also to quicken attention, to encourage rapid, precise, and 
 well co-ordinated movements, and to bring about the mental alertness and 
 the physical smartness which are elicited by any well-conducted drill. They 
 
 QQ2 
 
596 HYGIENE 
 
 tend to give grace and ease and freedom to the movements and to favom' a 
 good carriage. 
 
 No system of physical education is complete which is not founded upon 
 a sound grounding in free exercises. 
 
 It is only fair to state that some of the best of the free movements 
 carried out in the German system have been derived from the Swedish 
 schools. The exercises are perhaps, on the w^hole, more interesting and more 
 pictm'esque than those adopted by the Swedish system. They are, however, 
 less precise and less complete and less elaborately systematised as a part of a 
 progressive system of education. Not a few of these German free exercises 
 have little educational purpose, and appear to be adopted more for effect and 
 to meet the requirements of a public display. Some recent modifications and 
 additions have little claim to serious attention, and do not elicit the best 
 possible employment of the pupil's time. Compared wdth the Swedish 
 exercises, however, they are, on the whole, more popular with children, and 
 are certainly more picturesque. 
 
 (6) Another series of exercises involve the use of very light liand ajyj^aratus, 
 such as bar-bells, wooden dumb-bells, flags, hoops, &c. These exercises, 
 although they concern to a great extent the upper part of the trunk and the 
 upper limbs, involve also the development of the other muscles of the body. 
 The weight of the apparatus used is but a slight element in the exercises, 
 which are nearly of the same character as those just described. The 
 apparatus gives precision to the movements, makes the exercises more inter- 
 esting and more easily carried out, and renders the instructor's work some- 
 what less difficult. These exercises are adapted for elder children and form 
 a peculiarly valuable element in education. They represent an advancement 
 upon the free movements, and in a systematic and progressive plan of 
 instruction would naturally follow upon those exercises. These exercises 
 with apparatus may also be carried out to music. 
 
 (c) Although drilling does not form a very conspicuous element in the 
 German system, the subject may be conveniently introduced here, especially 
 as the modern gymnastic drill is largely a German production. A certain 
 amount of drilling is of value, and forms an efficient means of cultivating a 
 good carriage and an easy and free mode of walking and marching. Military 
 drill is a little tedious and formal and, to a considerable extent, purposeless, 
 so far as a full physical education is concerned. It tends to sharpen the 
 wits of dull lads and to encourage precise and active movements. It is, 
 however, uninteresting to the pupil, and does not afford in any way a com- 
 plete or satisfactory method of employmg the muscles. In the physical 
 training of cliildren it may well be replaced by more valuable exercises. 
 
 The musical drill of more modern times is very different from the drill- 
 sergeant's work. Musical drill appears to have been introduced from 
 America, and it now forms a conspicuous feature in most training schools. 
 It consists of marching or running in such a manner as to describe a variety 
 of figures, and always to music. 
 
 Under this heading come the many forms of the musical running or 
 marching maze, which include marching in two or four circles, or in reverse 
 circles, or in parallel lines, or in what is known as the serpentine course. 
 This drill is only possible with a comparatively large class. It is very 
 popular with children and with lads and elder girls. It forms an excellent 
 relaxation from the more formal exercises and represents running with a 
 purpose. Many admirable books have appeared on the subject. The three 
 forms of exercise just described are especially well adapted for children and 
 for instruction in schools. They serve to form the basis of a very sound and 
 perfect physical drill. 
 
PHYSICAL EDUCATION 597 
 
 If the work of a school could be interrupted for thirty minutes in the 
 middle of the morning in order that the children might go through some 
 few dumb-bell or bar-bell exercises in fresher air, and then finish up with 
 the running maze to music, something would be done towards securing a 
 reasonable development of the body. All that is required is a competent 
 teacher, plenty of floor or ground space, some very simple apparatus, and 
 equally simple music. 
 
 (d) The use of gymnastic apioaratus is considered in a subsequent section. 
 In the employment of apparatus and in the invention and elaboration of 
 gymnastic appliances of various kinds the German schools have been very 
 active. Indeed, the use of apparatus is so prominent in the system that it 
 has been often improperly considered to represent its principal feature. 
 
 8. The Swedish system, or the system introduced by. Ling, has attracted 
 very considerable attention, and has certainly been the m'eans of effecting not 
 only a remarkable improvement in physical education, but a change which 
 may be spoken of as little less than a revolution. It may be that the whole 
 method is not original, and that some of its features have been anticipated, 
 but as a system it has been enthusiastically accepted, and certainly met a 
 want which had been felt in physical education. 
 
 There was a time in this country when in the matter of physical educa- 
 tion there was little between somewhat violent outdoor sports and certain 
 acrobatic feats in the gymnasium on the one hand and the dreary instruc- 
 tion of the drill-sergeant on the other. The young girls of that period had 
 also, it must be allowed, the services of the so-called professor of deport- 
 ment, but of the value of his instruction it is difficult to speak. Physical 
 training in those days was for the strong. It encouraged specialisation ; it 
 did not concern itself with a systematic and progressive development of the 
 human body. 
 
 The Swedish system of physical training includes a very extensive series 
 of free movements, a series of exercises involving marching, leaping, running 
 and climbing, and certain carefully graduated exercises on the boom, rib- 
 stool, and window ladder. The free movements are admirable, and for them 
 these advantages can be claimed. They have been carefully worked out : 
 each series of movements are definite and precise, and are intended to 
 develop a special series of muscles ; the exercises are systematic and pro- 
 gressive, and form in their entirety a complete and simple system of physical 
 training. 
 
 The movements are not designed with a view to effect or display, but 
 simply to carry out the scheme of muscular training. They are designed 
 with care, and each accomplishes a specific object. The exercises begin with 
 the very simplest and gradually become stronger and more complicated. 
 
 The use of hand apparatus is only sanctioned after a complete mastery of 
 the free movements have been attained, and then only to add some intensity 
 to those movements. 
 
 The fixed apparatus mostly employed by teachers of the Swedish system 
 are the boom, the rib-stool, and the window ladder. The latter forms an ex- 
 cellent exercise for children and affords them no little amusement. The 
 method prepares the way for so-called sesthetical gymnastics, for fencing, 
 military driU, and other forms of applied gymnastics. 
 
 All the movements of the drill are applied to words of command, and the 
 pupil gains all those advantages, mental and otherwise, which attend the 
 teaching of exercises by the drill method, i.e. by word of command rather 
 than by imitation or by committing the movements to memory. 
 
 The Swedish system disapproves utterly of the use of music, and it is 
 ■contended that the exercises cannot be adopted to one set rliythm. 
 
598 HYGIENE 
 
 Against the Swedish method it may be m-ged that the exercises are a 
 little uninteresting to the pupils, that many of them appear ungainly and 
 purposeless, and that the great advantage of a musical acconipaniniGntis lost. 
 
 The chief movements may be classed under the following divisions : 
 
 (a) Fundamental positions. — These are intended to secure general atten- 
 tion and muscular control, and to establish the equilibrium and base of 
 support before more difficult exercises are undertaken. 
 
 (b) Arch flexions comprise various forms of backward flexions of the 
 trunk, and are intended to develop the dorsal muscles and those of the 
 abdomen, and, to expand the lower part of the chest. 
 
 (c) Heaving movements. — These comprise forms of self-suspension by 
 means of the arms on a horizontal bar or other apparatus, and serve to 
 expand the chest and to strengthen the muscles of the upper limb. 
 
 {d) Balance movements. — The positions are taken from a smaller area 
 than that included within the feet in standing ; the difficulty is increased by 
 diminution of the area of support. The exercises develop the equipoise of 
 the body and give grace to the carriage. 
 
 (e) Shoiolder-blade movements are concerned mainly with the scapular 
 muscles. 
 
 (/) Abdominal movements call into special action the muscles of the 
 abdomen. 
 
 [g) Lateral trunk movements.- — These include various forms of lateral 
 flexion of the body, and of rotatory movements, and concern generally the 
 muscles of the trunk. 
 
 (/i) Slow leg movements. — They are to specially develop the individual 
 muscles of the leg. 
 
 {i) Jumping and vaulting, and (j) respiratory exercises call for no- 
 explanation. 
 
 In the article on 'Physical Development,' in Keating's 'Cyclopaedia of 
 the Diseases of Children ' (vol. iv. p. 303), will be found a brief but lucid 
 exposition of the actual details of the Swedish drill, illustrated by numerous 
 figures of the various positions. 
 
 An excellent ' Manual of Swedish Drill ' has been produced by George 
 Meho (London, 1889). The reader may also consult a 'Manual of Free- 
 standing Movements,' by Captain Haasum, of the Eoyal Gymnastic Institute, 
 Stockholm (London, 1885). Both books are admirable. Mr. Melio's various 
 contributions to our knowledge of Swedish gymnastics have been very valu- 
 able, inasmuch as his early training was not carried out under the Swedish 
 method. 
 
 The Swedish system of physical training originated with Ling, and has 
 been considerably developed and extended by his pupils and followers. 
 
 Petter Henrik Ling was born at Ljunga, in Smaland, in 17G6. His early 
 hfe appears to have been absorbed by a struggle against poverty, and he 
 passed through many vicissitudes. He seems to have been engaged in many 
 pursuits and to have travelled in many countries. In 1800 he was studying 
 gymnastics at Copenhagen, and in 1804 he was engaged as a fencing master 
 at Lund. His system of physical training was elaborated after this date. 
 The Pioyal Gymnastic Institute was founded at Stockholm in 1815 at his 
 instigation, and remained under his supervision until his death in 1839. 
 
 Ling figured as a poet and a dramatist ; he dabbled with the flimsier forms 
 of metaphysics and held some crude conceptions of physiology. His educa- 
 tion was scarcely such as to fit him for the position he ultimately held. 
 
 Ling held that life consisted of the blending together of three elements — 
 the dynamic, the chemical, and the mechanical — and upon this belief his 
 
PHYSICAL EDUCATION 599 
 
 ' system ' was founded. Many of his exercises were only suited to invalids, 
 and he professed to have discovered the means of curing most diseases by 
 physical movements. His exercises were indeed divided into scholastic, mili- 
 tary, medical, and aesthetic gymnastics. He considered that every muscular 
 movement had a special effect upon the general health, and held that passive 
 movements had a definite value in promoting the development of the body. 
 
 It must be confessed that his system (excellent as some features of it 
 u.ndoubtedly are) was founded upon not a few extravagant theories and upon 
 bases which were not always scientific or accurate. 
 
 The medical side of the system has been the means of fostering a form 
 of quackery, and has led to the introduction of the * remedial exercises ' 
 and * movement cures ' which have done so much to bring Swedish gym- 
 nastics into discredit in this country. Out of the complex, heterogeneous, 
 and visionary material which makes up Ling's system, much that is really 
 good and valuable has been extracted. This is represented by the excel- 
 lent system of free movements already described and by many of the methods 
 of treating diseases by exercise which have been heartily accepted and de- 
 veloped by the medical men of this and other countries. In Anna Arnin's 
 ' Health Maps ' (London, 1887) and in Schreiber's ' Manual of Treatment 
 by Massage ' (Edinburgh, 1887) will be found good accounts of the application 
 of movements to the treatment of abnormal and diseased conditions. 
 
 In proposing a course of ' Swedish gymnastics ' or in advocating ' Ling's 
 system ' it is desirable that a clear knowledge should be possessed of what 
 is implied by these terms, and that encouragement be not offered to the 
 ' remedial measures,' the ' movement cures,' and the quackery with which this 
 otherwise excellent system is attended. Any instructor who describes himself 
 as a ' medical gymnast ' will probably not be sought for as a teacher. 
 
 Ling's system in its entirety could hardly be accepted at the present day. 
 Such portion of the Swedish system as deals with the practical part of 
 physical education pure and simple must, however, be accepted as of con- 
 siderable worth. 
 
 Gymnastic Appaeatus 
 
 Under this title will be considered the use of such apparatus as will be 
 found in a well-equipped gymnasium. A good gymnasium should have 
 ample space, good light, very free ventilation, the best possible apparatus, 
 and a fully quahfied instructor. 
 
 The fresher the air and (within limits) the cooler the room the better. 
 A properly ventilated gymnasium has an unlimited supply of fresh air with- 
 out draughts. If there be a time when plenty of oxygen is required it is when 
 young persons are taking violent exercise. Many gymnasia are ill-lit, 
 cramped, and very badly ventilated. 
 
 The majority of the exercises involved in the use of gymnastic apparatus 
 involves considerable strength and much practice. 
 
 It is madness for a man out of training and unaccustomed to exercise 
 to commence in a gymnasium the use of such apparatus as the horizontal 
 bar or the vaulting horse. Many children, especially girls, have been 
 seriously damaged by the violent exertions undertaken in improperly con- 
 ducted gymnasia. 
 
 Such gymnasia have done a very great deal to bring physical training into 
 discredit. A boy of about ten has joined a ' gymnastic class ; ' his physical 
 condition has never been examined and his physical capacities never in- 
 quired into. He enters the gymnasium, and without any prehminary training 
 
GOO HYGIENE 
 
 attempts the feats he sees other pupils performing without perhaps having 
 received any definite instruction. The boy goes home dead-beat, feeble, and 
 sick at heart at his ill-success and aching with his unwonted exertions. Next 
 day he presents all the phenomena of extreme fatigue and perhaps the symp- 
 toms of muscular strain. I have known more than one instance in which 
 a hernia made its appearance after a first attendance at a gymnasium. 
 
 The very greatest care should be exercised in the management of all 
 children and young people sent to a gymnasium. Parents who take infinite 
 pains to superAase the mental education of their children often take not the 
 least trouble to ascertain the conditions under which their bodies are being 
 trained. A lad comes home with a headache and Avith all the symptoms 
 of exhaustion from the hour's drill, and is not allowed to attend again on the 
 grounds that he is not * strong enough for rough exercise.' A visit to the 
 gymnnsium may have shown that the headache was due to an ill-ventilated 
 and over- heated room, and the exhaustion to totally unsuitable exercises. 
 
 It must be remembered that physical training requires discretion ; 
 that a great mass of pupils, even when of the same age and sex, cannot be all 
 dealt with en masse by fixed rules. The exercises selected and the apparatus 
 to be used must be determined, not by rule of thumb, but by the precise needs 
 of each individual case. This observation will not apply to drilling and to 
 simple mass exercises, but it applies in a very emphatic manner to apparatus. 
 
 A gymnasium is worse than useless without an efticient and careful 
 instructor. Gymnastics cannot be self-taught. The process of training must 
 be gradual, and so graduated as to meet the pupil's particular needs and 
 particular state of development. 
 
 So-called exercise in a gymnasium without a teacher usually means pur- 
 poseless romping. It may safely be said that the great majority of the 
 accidents which occur in gymnasia occur during forbidden hours or when the 
 pupil is attemptmg exercises by himself of which he has no precise knowledge. 
 
 Put an active boy in a gymnasium and pay no attention to his training, 
 and he mil assuredly begin to ' play the fool,' to ' skylark,' to develop 
 uncouth modes of exercising his limbs, and in the end very probably do him- 
 self more or less material damage. 
 
 The pupil in a gymnasium must be content to begin at the beginning, 
 must learn to be patient and to overcome failures, must be ready to believe 
 that there are many exercises he can never perform, and that he is endeavour- 
 ing to acquire health and strength, and not to qualify himself for the pro- 
 fession of an acrobat. Above all things, work in a gymnasium must be 
 gradual, regular, and systematic. 
 
 A very lamentable spectacle is that afforded by a middle-aged man 
 who feels he is becoming stout and who thinks he will ' take to gym- 
 nastics.' He attempts at once the exercises he sees his younger colleagues 
 jjerform with such complete ease. If such a man escapes with no greater 
 injury than is represented by being rendered breathless, by having several 
 muscles sprained, and by being laughed at, he may consider himself fortunate. 
 
 In general terms it may be said that the gymnasium is not well suited for 
 children, is best suited for lads and young men between the ages of seventeen 
 and twenty-five, and is but indifferently adapted for men over thirty, unless 
 they have kept up the physical acquirements of their youth by constant 
 practice. 
 
 It is important also to bear in mind that gymnastic exercises with 
 apparatus all tend to develop the upper limbs and the upper half of the trunk. 
 
 The gymnasium cannot provide the means for a complete physical edu- 
 cation, and work in it should never so far absorb the time devoted to 
 
PHYSICAL EDUCATION GOl 
 
 physical training as to exclude recreation in the open air and outdoor 
 games and exercises. Exercises with apparatus come at the end, and not at 
 the beginning, of a course of physical training. 
 
 A very brief description of the commoner apparatus will now be given. 
 
 Dumb-bells. — These should be light and should be made of sycamore wood. 
 The weight for boys should be 1 lb. each bell, 2 lb. for lads, and 3 lb. for 
 adults. Heavy dumb-bells are to be condemned. The chief feature of proper 
 dumb-bell exercises is the great frequency with which they are repeated and the 
 length of time the movements are kept up. The weight of the bell is not a 
 factor of any moment in the exercise, but the apparatus serves to give interest 
 and precision to the movements carried out. Heavy dumb-bells involve 
 considerable effort compressed into an inconsiderable time. Such bells are 
 only of use to athletes who wish to specially develop their arms. 
 
 Dumb-bell exercises are admirable. They can be adapted for individuals 
 of all ages and of all conditions of physical strength ; they are well suited 
 for class exercises ; and a musical drill with light dumb-bells forms a pleasant 
 feature in the training of boys and girls. Both bells should be used at the 
 same time. 
 
 The exercises encourage a good carriage, rapid and precise movements, and 
 the equal, symmetrical, and simultaneous use of the muscles upon both sides 
 of the body. 
 
 These exercises tend to develop the chest and to exercise the muscles of 
 the abdomen and back. 
 
 It is true the arms are conspicuously employed in dumb-bell movements, 
 but if the drilling is efficient nearly all the muscles of the body are well, 
 although not equally exercised, and especial employment can be given to the 
 muscles of the back. 
 
 Bar-bells. — These are of ash. The shaft is five feet long (for adults) and 
 three-quarters of an inch in diameter. The knob at each end is three inches 
 in diameter. 
 
 The exercises carried out with bar-bells resemble those performed with 
 dumb-bells. They have especial value in developing the muscles of the 
 chest and of the abdomen. The muscles of the upper limbs are somewhat 
 unduly exercised, and considerable work can be thrown upon the muscles of 
 the back. This apparatus is excellent for the narrow-chested. It encourages 
 symmetrical movements, a graceful carriage, and general lissomness of the 
 body. Bar-bells are extensively used in the training of young girls. 
 
 By the use of double bar-bells a still more extensive use of the general 
 muscular system is involved. In these exercises two bar-bells are held at 
 either end by two pupils ; in all movements the two pupils must act in 
 concert. The exercises concern the whole of the muscles and afford ex- 
 cellent training in symmetrical, rapid, and precise movements. 
 
 Indian Clubs are made of pine wood, and are about 24 in. in length and 
 some 3| in. in diameter at the thick end. The exercises are only suited for 
 adults and for muscular persons. They encourage a firm and upright attitude, 
 and develop principally the upper part of the trunk and the upper limbs. 
 
 Many of the movements are very elaborate and require great nicety of 
 execution. 
 
 Parallel Bars should be about 9 ft. long, 20 in. apart, and about 4 ft. from 
 the ground. Every instructor in gymnastics recognises that the parallel bars 
 form one of the most useful apparatus in the gymnasium. ' The exercises,' 
 writes Maclaren, ' are not only numerous but varied, interesting, and in them- 
 selves pleasurable, capable of much artistic effect, and requiring equally 
 muscular power and dexterity of action in the upper limb.' 
 
602 HYGIENE 
 
 The usual exercises are progressive and none are violent. The apparatus 
 is suited for properly trained pupils of any age after twelve or fourteen, and 
 ■within limits for both sexes, provided that the muscular development of the 
 learner is efficient. The exercises improve the grasp, develop the muscles 
 of the upper hmb, and especially the muscles passing between the upper 
 limb and the trunk. They are well adapted for individuals with slight arms, 
 wuth narrow and sloping shoulders, and with contracted chests. Excessive 
 use of the bars tends, however, to develop to excess the posterior scapular 
 muscles. The muscles of the abdomen are employed, but comparatively 
 little use is made of the lower extremities. 
 
 The Horizontal Bar is about six feet long, has a diameter of 1| in., and 
 is raised from three to seven feet from the ground. This valuable apparatus 
 is adapted for pupils of almost any age above ten or twelve. The exercises 
 are varied and progressive, and can be made to suit various degrees of mus- 
 cular development. 
 
 The simpler exercises develop the muscles of the upper limbs and of the 
 upper part of the trunk ; the more advanced call into play the muscles of the 
 back and of the abdomen and to a less extent the muscles of the lower limbs. 
 The apparatus if used to too great an extent tends to develop the upper limb 
 muscles to a disproportionate extent. 
 
 The simpler exercises are adapted under careful restriction for girls 
 with weak spines, and for those with small scapular muscles and slender 
 shoulders. 
 
 The more elaborate exercises require considerable strength and agihty, 
 and are only suited for the athletic and very muscular. 
 
 In certain of the primary exercises the abdominal muscles are especially 
 employed. 
 
 The Trapeze is made of hickory or ash, is about 20 in. in length and 
 some I in. in diameter. The height at which it is suspended from the 
 ground, and the length of the ropes, must depend upon the capacity and age- 
 of the learner. 
 
 The exercises are very similar to those of the horizontal bar, but as the 
 pupil can swing at the time of practising this apparatus is very popular. 
 
 It mainly brings into play the muscles of the upper limbs and those pass- 
 ing between the trunk and that member. It is of service in cases of feeble 
 back and commencing lateral curvature, and can be made admirable use of 
 in developing especially the muscles of the abdomen. 
 
 A mattress must always be placed beneath the low trapeze and a net 
 beneath the higher apparatus. Great care must be taken in carrying out 
 the movements, and this apparatus has been the cause of not a few acci- 
 dents. The more elaborate movements are only adapted for the practised 
 athlete, and some of the finest displays of gymnastic skill are made with the 
 trapeze. 
 
 The Hand Rings have a diameter of from 5 to 9 in., are placed about 
 18 in. apart when used by adults, and at a distance of 3 to 6 ft. from the 
 floor. This apparatus is also very popular. The exercises closely resemble 
 those carried out upon the trapeze. The same sets of muscles are concerned. 
 The apparatus, if properly employed, is excellent for cases of lateral cur- 
 vature ; the lateral muscles of the trunk can be very fully and efficiently 
 exercised, and one side can be especially developed if required. 
 
 The more elaborate exercises concern the muscles of the back and 
 abdomen, and indeed the whole muscular system with the exception that the 
 lower limbs are but little involved. 
 
 Unless care be exercised it is easy for young pupils to produce an unsym- 
 
PHYSICAL EDUCATION 60a 
 
 metrical development of the back muscles by an improper use of this 
 appliance. 
 
 The Vaulting Horse is a valuable apparatus. The body should be from 
 5 to 6 ft. in length and should be capable of being adjusted at any height. 
 Mattresses must be placed around it, and a sloping board is generally placed 
 in front of it for lea^ping exercises. 
 
 The vaulting horse is well suited for children and the young and for 
 athletic adults. It is scarcely the apparatus for the middle-aged. It may be 
 used by girls under puberty, but its use in older females is open to some 
 question (see page 593). 
 
 The exercises are varied, are pleasurable, and are popular with young 
 people. It is well suited for class instruction. The simpler exercises consist 
 of vaulting over the horse in different ways. The exercises develop all the 
 muscles of the body, the lower limbs as well as the upper, the spine as well 
 as the abdomen. Its use brings about a good grasp, a certain amount of 
 agility and precision of movement, and cultivates a good swing of the body. 
 It forms an excellent means of cultivating the respiratory apparatus and 
 brings out the muscles about the pelvis. 
 
 One of the most popular lessons in a gymnasium is represented by a class 
 of pupils who form in line and vault over the horse one after the other, keep- 
 ing up a continued round and run. 
 
 The more advanced exercises are only suited for athletes and are elaborate 
 and difficult. No gymnasium can be considered to be complete without some 
 form of vaulting horse. 
 
 The Inclined Ladder as usually employed exercises mainly the muscles 
 of the upper limb and upper part of the trunk. The exercises, like all other 
 suspension exercises, are excellent for cases of weak back with tendency to 
 curvature of the spine provided that they are carefully planned and super- 
 vised. 
 
 The apparatus affords good practice in balancing the body in the exercise 
 of mounting the ladder with the feet only and is useful for developing the 
 abdominal muscles. It is suited for pupils of various ages and of both sexes 
 with certain limits. 
 
 The Ladder Plank is another useful and popular apparatus. The machine 
 is made in many different ways. For adults the plank is about 18 in. wide, 
 and from either side of it project spars which are 6 in. in length and 9 in. 
 apart. 
 
 The exercises on this machine can be adapted to individuals of all ages, 
 of both sexes, and of all degrees of muscular development. 
 
 The muscles of the entire body are exercised, although those of the upper 
 limbs and of the upper part of the trunk receive most employment. Maclaren 
 thinks that no machine in the gymnasium so rapidly and powerfully aids in 
 the expansion and development of the upper part of the trunk as does the 
 ladder plank. 
 
 This is a good form of apparatus for cases of lateral curvature of the spine ; 
 especially good are the exercises which involve the descending of the plank 
 backwards, i.e. with the back to the plank. These exercises also throw the 
 chest out to its utmost, and the apparatus is useful for the narrow-chested 
 or pigeon-breasted. It is a valuable apparatus for growing girls and is 
 
 The Horizontal Ladder gives opportunity for a good series of suspension 
 exercises, which concern mainly the muscles of the upper limb, but which 
 also develop, to a lesser degree, the muscles of the back and of the abdomen. 
 This is another apparatus of service in cases of weak or distorted back. 
 
€04 HYGIENE 
 
 ApparaUis for Climbing. — Climbing affords excellent exercise, is very 
 popi^lar among children, is suited for pupils of both sexes and for individuals 
 of almost any age. It is not suited for those who have not had special mus- 
 cular training, nor for the corpulent, nor for those who are past middle life. 
 All climbing exercises may be considered as advanced exercises. 
 
 Climbing may be effected in different ways, and children are very apt to 
 acquire tricks in climbing which tend to distort the body and to develop it 
 imequally. The movements of chmbing must be carried out very precisely 
 and methodically, and must be carefully superintended by the instructor. 
 Girls and young women often make excellent climbers. The exercise con- 
 cerns all the muscles, but especially those of the upper limbs. It also tends 
 to develop the muscles of the thighs, back, and abdomen. It is not a good 
 exercise for the subjects of spinal curvature. 
 
 The apparatus used comprises (1) the vertical pole, a smooth pole of any 
 height, and with a diameter varying from two to three inches ; (2) the 
 slanting pole, which involves a combination of exercises represented by the 
 vertical pole and the slanting ladder. Tliis apparatus is of value in develop- 
 ing the muscles of the abdomen as well as those of the upper limb. (3) The 
 turning pole is hardly suited for any but active youths and trained athletes. 
 The exercises are difficult, involve much muscular power, and, above all, great 
 dexterity, precision, and accuracy of movement. The apparatus consists of a 
 slanting pole so adjusted as to revolve on its longitudinal axis. The great 
 difficulty of the exercises consists in the maintenance of the balance on a pole 
 which is not fixed. (4) The pair of vertical poles (two parallel poles placed 
 eighteen inches apart) is an apparatus only suited for advanced gymnasts. 
 The exercises are very arduous and demand great strength and much practice. 
 They concern mainly the upper part of the trunk and upper limbs. (5) The 
 vertical rope varies in length and has a diameter of from 1^ to 2 inches. The 
 exercises resemble those of the vertical pole, but are a little more varied and 
 make more use of the lower limbs. (6) The Eosary consists of a vertical rope 
 suspended from the ceihng, but not fixed at the foot, upon which are strung 
 at intervals of from ten to eighteen inches elm heads, four inches in diameter 
 and flat on the top. This affords good exercise in climbing for children — 
 boys and girls — and for beginners. It employs all the muscles — those of 
 the abdomen and back as well as those of the limbs — it concerns most par- 
 ticularly the muscles of the upper limbs. It gives exercise to the muscles 
 about the hips and loins, especially if it be understood that the rope must 
 always be kept in the vertical line. (7) The mast (which has a diameter of 
 ten to twelve inches) is only suited for accomplished athletes. 
 
 The Giant's Stride.— This apparatus is more often found in the playground 
 than in a gymnasium, and is seldom among the machines contained in the 
 room. It affords good exercise for the muscles of the body, for the arms, the 
 legs, the abdomen, and the back. The exercise interests children and the 
 apparatus is always popular. It is useless, however, if the exercise be not 
 regulated, and if children be not individually instructed in the simple but 
 necessary movements. The children, moreover, should be about of the same 
 size and if possible of the same state of physical development. 
 
 It is common to see children on the giant's stride whose movements are 
 aimless and useless, who swing loosely about, and who either hamper the 
 movements of the children behind them or are hampered by the struggles of 
 the performer immediately in front of them. An undisciplined crowd of 
 children who without instruction, selection, or arrangement try to gain en- 
 joyment and strength from the giant's stride had better devote their energies 
 to simpler pursuits. 
 
PHYSICAL EDUCATION G05 
 
 Homo Gymnasia 
 
 The so-called home gymnasium is usually more or less of a delusion and 
 a snare. It is, as a rule, too elaborate to be of practical value, and too com- 
 plicated for children's use. It often pretends more than it can accomplish. 
 A swing, parallel bars, a knotted rope, and an inclined ladder form excellent 
 elements in a home gymnasium, provided the children have been already well 
 trained by means of simpler exercises. 
 
 A good machine for home use is an American invention, the so-called 
 ' Excelsior ' gymnasium. Here the power of the performer is exercised 
 against weights attached to ropes passed through pulleys. The apparatus is 
 capable of exercising all the muscles of the body, admits of almost endless 
 combinations, and can be graduated to meet the needs of a child or an 
 athlete. The rowing exercises on a sliding seat and the contrivance for 
 developing the muscles of the back are in every way admirable. The 
 machine is, moreover, strong, simple, and portable, and occupies but little 
 space in a room. 
 
 The appliances which owe their main features to elastic bands are of 
 limited use, are restricted chiefly to the development of the upper extremities, 
 and involve a very monotonous form of exercise. A home gymnasium is a 
 useful apparatus in a bathroom or bedroom, where it can be used every 
 morning before or after the morning bath. 
 
 In concluding this part of the subject attention must once more be 
 directed to the circumstance that a inoper and complete physical education 
 cannot he carried out by means of apparatus. Apparatus come last in a 
 progressive system of physical training, and must always be used with great 
 care and very sparingly. A large proportion of the exercises are totally 
 unsuited for young subjects, and are only open to athletes or professed gym- 
 nasts. The tendency of the usual apparatus is to produce an unequal 
 development of the body, to develop the muscles of the arms and shoulders 
 and pectoral regions, and to neglect the muscles of the lower part of the 
 trunk and of the lower limbs. In a subsequent section attention is drawn to 
 the deformity produced by an excessive or exclusive use of the usual gym- 
 nastic appliances. 
 
 Outdoor Games 
 
 It is quite impossible to attempt to give any account of the particular 
 value each of the many outdoor games may possess in relation to physical 
 education. 
 
 In general terms it may be said that when played in moderation and 
 under suitable conditions they are most excellent. They involve movement 
 in the open air, very varied muscular exercise, a considerable amount of 
 healthy interest and excitement, and the cultivation of a certain degree of 
 skill and special adroitness. The parts that the great games of cricket and 
 football have played in the development of the English people can scarcely 
 be overrated. 
 
 These games not only involve healthy exercise and demand skill, but they 
 require readiness of action, determination, foresight, sound judgment, and 
 good temper. They tend to develop personal courage, self-reliance, the 
 spirit of honour, and the impulses of loyalty. They cultivate all those 
 qualities which make a man manly and wholesome in mind. If one wants 
 to seek for the sneaks and cowards in a school, for the poor-hearted and un- 
 wholesome-minded, search must be made, not among the cricket and football 
 teams, but among the loafers. 
 
GOG HYGIENE 
 
 Cricket can be played at almost any age, and is as well adapted for young 
 women as for young men. It is necessary only that the players should be 
 as nearly equal in strength as is possible. 
 
 With regard to the game of football, I cannot do better than give two 
 quotations fi'om Mr. Shearman's admirable article in the Badminton Library 
 volume. Before doing so it is needless to say that football as now played is 
 a game which involves great skill and considerable intelligence. The heavy 
 man who played ' forward ' in days gone by, and who could stand a good 
 hacking, and could hack in turn, is now no longer of any use in a football 
 team. Other things being equal, the more intelligent the man, the better 
 the player. In my opinion there is no outdoor game for lads and young 
 men equal to football, whether it be the Eugby Union or the Association 
 game. 
 
 Thus writes Mr. Shearman : ' For at least six centuries the people have 
 loved the work and struggle of the rude and manly game, and kings with their 
 edicts, divines with their sermons, scholars with their cultured scorn, and 
 wits with their ridicule have failed to keep the people away from the pastime 
 they enjoyed. Cricket may at times have excited greater interest amongst 
 the leisured classes ; boatraces may have drawn larger crowds of spectators 
 from distant places ; but football, which flourished for centuries before the 
 arts of boating and cricketing were known, may fairly claim to be, not only 
 the oldest and the most characteristic, but the most essentially popular sport 
 of England. 
 
 ' Football may be rough, may be at times dangerous ; so is riding across 
 country ; so is boxing ; so is wrestling. The very function and final cause of 
 rough sports is to work off the superfluous animal energy for which there is 
 little vent in the piping times of peace. Since football became popular with 
 aU classes, there have been less wrenching off of knockers and " boxing of 
 the watch," and fewer " free fights " in the streets. Football has its national 
 uses quite apart from the cheap enjoyment it has given to thousands. It may 
 be rough, but it is not brutal. 
 
 ' Next as to the danger. Doubtless there are accidents, and doubtless men 
 have been killed upon the football field. But during a quarter of a century 
 how many thousands of men have played, and have a score of these many 
 thousands lost their lives ? Fewer than those who have been drowned on the 
 river, not a tithe of those who have fallen in the hunting field, are the victims 
 of football. If the outcry against football because of its danger could be 
 justified, not a single outdoor sport could survive. 
 
 ' For every one who may have been harmed by football a thousand have 
 benefited by it. Health, endurance, courage, judgment, and, above all, a sense 
 of fair play are gained upon the football field. A footballer must learn, and 
 does learn, to play fairly in the thick and heat of a struggle. Such qualities 
 are those which make a nation brave and great. The game is manly and 
 fit for Englishmen : " it puts a courage into their hearts to meet an enemy 
 in the face." ' 
 
 THE ELEMENTS OF PHYSICAL EDUCATION 
 
 1. TJie exercises should be adapted to meet the needs of each individual 
 case. 
 
 It is to be borne in mind that the object of a proper physical education 
 is to develop health and not strength, to bring the body to its highest degree 
 of perfection and not to convert children and youths into gymnasts and 
 acrobats, and that its main object is to best fit the individual for the duties 
 
PHYSICAL EDUCATION GOT 
 
 and work of life and not to elicit proficiency in mere feats of sldll and 
 adroitness. 
 
 It must not be forgotten, moreover, that individuals vary greatly in the 
 quality of their physical powers and in their capacity for muscular exercise. 
 It is just as impossible to form a great mass of children into one gymnastic 
 class as it is to place those children in one school standard under one 
 teacher. Neither age, height, size, nor sex affords sure means of classifying 
 children, so far as the needs of a proper physical education are concerned. 
 Each individual must be considered upon his or her own especial merits, and 
 there is no method of physical training which is universal or all-sufficing 
 and adapted for all sorts and conditions of human beings. 
 
 The sending of a child to a gymnasium, or the placing of it under the 
 care of a drill-sergeant, is as crude a procedure as the conducting of a child 
 within the walls of the first school met with, and leaving it there with the 
 impression that it will somehow be educated. Physical education requires 
 as much care as does mental education, and if there be ten ' forms,' or 
 ' standards,' or ' classes ' in a school which is concerned in mental training, 
 there would probably be at least as many forms and standards in any insti- 
 tution which deals with the training of the body. 
 
 Instructors in gymnastics and so-called calisthenics are for the most part 
 somewhat irresponsible beings ; their training has often been narrow and 
 incomplete, and their methods are fixed and inelastic. They regard their 
 pupils in the aggregate and not as individuals. There are of course numerous 
 striking exceptions. 
 
 It is to be hoped that a time will come when those who profess to train 
 the body will be required to produce as definite evidences of fitness as is 
 demanded of those who aim at training the mind. 
 
 One society in England — the National Health Society — has prepared a 
 scheme for the examination of instructors in gymnastics and for the grant- 
 ing of diplomas and certificates to such as attain to the prescribed standard. 
 
 Such a scheme has been carried out in America, and serves, not only to 
 do justice to competent teachers on the one hand, but to protect the public 
 on the other. The National Health Society requires, among other things, 
 that the candidate shall possess a certain knowledge of elementary anatomy, 
 of the physiology of bodily exercise, of the various methods of physical 
 training, and of the details of the various exercises and the uses of all gym- 
 nastic apparatus and appliances. The candidate is required, moreover, to 
 produce evidence of physical fitness and of a proper training in some recog- 
 nised gymnasium or training school. 
 
 The casual, perfunctory, and unmethodical manner in which physical 
 training in many schools is carried out at the present day is very 
 lamentable. 
 
 The need of a proper training is especially felt in girls' schools, in schools 
 which are patronised by the lower middle class, and in the elementary schools 
 controlled by the Education Act. 
 
 In the great public schools, and at the two great English universities, 
 physical education is in a very flourishing and exuberant condition, and only in 
 need perhaps of a little more method, a little more science, and a httle more 
 regard for the individual and the development of the feeble as well as of the 
 strong. 
 
 The first necessity in physical education is a knowledge of the condition, 
 the wants, and the possibihties of the individuals to be educated. This can 
 only be obtained by an individual inspection. It would be well if in the 
 elementary schools a plan such as the following could be carried out. Each 
 
COS HYGIENE 
 
 cliild on entering tlie scliool should liave a book in wiiicb tlie following 
 details should be entered : — 
 
 1. Name ; 2. Age ; 3. Height ; 4. Weight ; 5. General aspect and 
 physique (the entries under this heading could be greatly extended and bo 
 made of much service if a competent medical man made the inspection) ; 
 6. Chest girth ; 7. Breathing capacity ; 8. Span of arms ; 9. Girth of arms ; 
 10. Drawing or pulling power as tested ; 11. Girth of legs ; 12. The exist- 
 ence of any evident deformity, defect, or disease. (This section could only 
 be properly developed by a medical man. The conditions dealt with would 
 be such as the following : spinal curvature, hernia, rickets, deformed 
 thorax, stiff joints, infantile paralysis, enlarged tonsils, glandular disease, 
 lung disease, condition of abdominal viscera, evidence of convulsions, &c.) 
 
 In this last section much could be done by a properly trained teacher, 
 but a medical inspector would render the evidence in every way of greater 
 value. 
 
 The child's physical condition should be inquired into with as much 
 care as is exercised in examining an adult for life insurance. The urine 
 should be tested if possible, and if the parents can be seen the child's family 
 history should be inquired into. 
 
 Still, apart from an examination by a medical man, the twelve points pre- 
 scribed -would form the basis of a valuable record and place the physical 
 education of the child upon a rational footing. Such a record should be kept 
 also of all individuals attending gymnasia and undergoing any form of 
 physical training. Upon the evidence afl'orded the precise exercises which 
 were desirable and the precise methods of training to be carried out could be 
 determined. 
 
 The record may well be extended, and could with great advantage record 
 a test of the child's vision, and add evidence on the questions of astigmatism 
 and colour-blindness. This record, kept in the form of a book, should be 
 filled up every three months. If properly kept, the value of such a book would 
 be enormous. To the individual it would possess more than mere interest. 
 It would show the history of his early life, the record of his development, and 
 would afford an admirable guide to any medical man should the individual 
 in the future become the subject of disease. 
 
 Mental training is exceedingly important without doubt, but it may be 
 that the time will come when the Government of this country will recognise 
 the importance of physical training, and will realise that among the children 
 in elementary schools a strong body is almost as important as, and often more 
 useful than, a well-stored mind. Many of these children are turned out 
 into the Avorld pale, sickly, ill-developed, and feeble. That at present many 
 unremediable causes may conspire to produce this is evident enough, but the 
 state of things is susceptible of improvement. The health and strength and 
 physique of the poorer classes may be placed upon a better basis, and a 
 number of sturdy and strong men and women produced in the place of the 
 multitude of poor creatures who after a more or less doleful and useless 
 life become prematurely a burden upon the rates. 
 
 The systematic examination of the individual and the conducting of a 
 physical education upon precise and scientific grounds have already been 
 carried out in some cities in America. 
 
 An excellent account of some of these institutions will be found in the 
 record of the Physical Training Conference held at Boston in 1889. 
 
 2. The exercises should be carefully devised, systematically arranged, 
 and suitably graduated. 
 
 The course of education should be planned upon a definite system and 
 
PHYSICAL EDUCATION 609 
 
 the classes formed, and when occasion demands remodelled, according to the 
 physical status of the individual members. 
 
 The exercises must be graduated, and no attempt made to pass from one 
 series until the more elementary stages have been mastered. 
 
 It is of especial importance than none of the more comphcated, difficult, 
 and arduous exercises should be forced upon those who are physically unfit. 
 They must be always — from the learner's standpoint — moderate and pro- 
 gressive. 
 
 It is desirable also that the lessons should be as varied and as interesting 
 as possible, and that reasonable opportunity be given for competition and the 
 encouragement of those who are specially fitted to excel. 
 
 The exercises should aim at the equal employment of all the muscles, and 
 not at the development of a few. The work in an ordinary gymnasium tends 
 to throw strain mainly upon the upper extremities, while most of the out- 
 door games tend to develop the lower limbs. No great good can be obtained 
 from tedious drilling and purposeless marching, and the time devoted to 
 physical training should never be so fully absorbed as to allow no leisure for 
 games and other pleasant forms of recreation. 
 
 In any instance violent intermittent exercises should be forbidden, and 
 the performance of feats of strength should never come within the scope of 
 the educational scheme. 
 
 3. The exercises should he carried out under proper guidance, and toith 
 suitable and efficient apparattis. 
 
 The teacher should be capable of instructing a large class — a qualification 
 which is not commonly possessed. 
 
 4. The time for the exercises should he carefully selected. 
 
 Violent exercise after a full meal is obviously bad, and a course of 
 physical instruction should not be carried out in the case of children who are 
 tired from a long day's attendance in school, or who are feeble for want of food. 
 
 In the matter of schools it is well that the period for physical training 
 should be interpolated among the hours devoted to ordinary school work. If 
 between the hours of nine and twelve or nine and one the children could be 
 allowed to take systematic exercise for thirty minutes, either in the open 
 air or in some suitable building other than the schoolroom, they would be 
 found to be actually refreshed by the change of occupation, to enjoy a period 
 of mental rest, and to return to their work with vigour. 
 
 Another half-hour could be introduced during the progress of the after- 
 noon lessons. The Eev. E. Warre, one of the masters at Eton, advises that 
 a schoolboy's day should be disposed of as follows : Eest ten hours, work 
 seven hours, meals and play seven hours. 
 
 So far as adults are concerned, the taking of violent exercise in the 
 evening after a long and arduous day's work is often injurious in its result. 
 
 There is no time better than the early morning before the labours of the 
 day are commenced. 
 
 Adults who have been accustomed to exercises of strength and endurance 
 should return but cautiously to such pursuits if they have passed through a 
 long period of rest from exercise and are out of condition. A man may ride 
 fifty miles a day on a bicycle very easily in the autumn, but he would be 
 very unwise to attempt such a distance in the following spring, provided that 
 he had taken no exercise during the winter. 
 
 5. Exercises, so far as is possible, should be taken in the open air or in a 
 large and very well-ventilated room. 
 
 6. Those who are taking systematic exercise should be properly clad. 
 The garments should be light, loose, and made of wool. It is desirable 
 
 VOL. I. R R 
 
010 HYGIENE 
 
 that care be taken not to catcli cold by standing about in clothes which are 
 damp with perspiration. 
 
 This question of clothing is more fully dealt with in another section of 
 this work. 
 
 FOEMS OF EXEKCISE 
 
 So far as any classification can be made — and it must of necessity be 
 rough — exercises may be divided into the following classes : — 
 
 1. Exercises of Strength 
 
 These involve actual and considerable muscular power, and are illus- 
 trated by advanced exercises in the gymnasium, with apparatus such as the 
 horizontal bar, the trapeze, the rings. In a special category may be placed 
 what may be termed feats of strength, such as lifting great weights, putting 
 the shot, throwing the hammer, and the like. 
 
 These exercises involve ' effort,' i.e. the muscular position in which the 
 man takes a deep breath, and then, when his chest is full, closes his glottis, 
 so that he may make the thorax a fixed base from which the upper limbs 
 can act. During the performance of the movement he does not breathe, 
 his face becomes engorged, and the veins which stand out upon his fore- 
 head demonstrate the distended condition of the right side of the heart. It 
 is during * effort ' that some sudden and fatal accidents have occurred, such 
 &s rupture of the heart and the giving way of blood-vessels. 
 
 2. Exercises of Speed or of Bapid Movement 
 
 These include running in all its forms and such exercises as involve 
 very rapid and continued movements. The individual muscular contrac- 
 tions are not extreme, but they are very quickly repeated. The amount of 
 work performed is distributed over a considerable period, and is not, as in 
 exercises of strength, concentrated into a few moments. 
 
 These exercises are susceptible of considerable modification, and range 
 from the extreme effort of the sprint runner to the easier movements of the 
 paper-chaser or of the devotee of the skipping-rope. 
 
 Certain forms of gymnastic exercise rank in this class. The movements 
 tend to develop the respiratory capacity, and are the exercises which soon 
 bring about the state of breathlessness. 
 
 3. Exercises of Endurance 
 
 In these the muscular effort is inconsiderable at any given moment, and 
 is distributed over a still longer period of time. 
 
 Neither breathlessness nor rapid muscular exhaustion arrests the subject 
 of the exercise. The continuance of his movements becomes a matter merely 
 of endurance. Walking is a type of this variety. And in the same class 
 must be placed many outdoor games, skating, rowing and cycling, drilling 
 and such exercises as are generally included under the term Swedish gym- 
 nastics. 
 
 In the training of the body the exercises of endurance must occupy the 
 first, the most prominent, and the most important place. 
 
 4. Exercises of Skill 
 
 are illustrated by the more complex gymnastic exercises, such as those 
 which involve balancing, &c., by fencing and any other movements which 
 imply, not necessarily severe or continued muscular exertion, but great acti- 
 vity of the brain and spinal cord. 
 
PHYSICAL EDUCATION 611 
 
 The fencer in his earher days becomes weary in his body, but as he 
 becomes more experienced he ' feels ' the exercise, not in his muscles, but in 
 his nervous system. 
 
 6. Exercises which Develop the Chest 
 
 may on account of their importance be especially classified. The exercises 
 which come under this class are such as tend to develop the muscles of the 
 chest — namely, the pectorals, the serratus magnus, the latissimus dorsi, the 
 anterior abdominal muscles, and some others of lesser importance. 
 
 This, however, is not all. As Dr. Lagrange has pointed out, the size of 
 the thoracic cavity can only be increased by increasing the volume of its 
 contents, the lungs. ' It is from within outwards,' writes that author, ' that 
 the force capable of expanding the chest acts, and it is in reality to the lungs 
 and not to the muscles, that the chief share in the changes in form and size 
 of the chest belongs. The most powerful inspiratory muscles cannot raise 
 the ribs, unless the lungs participate in the movement of expansion, and on 
 the other hand the lungs can raise the ribs without the aid of the muscles, 
 for the chests of emphysematous patients remain vaulted in spite of their 
 efforts to lower the ribs and complete the respiratory movement. . . . Moun- 
 taineers all have large chests, and the Indians who live on the high plateaux 
 of the Cordillera in the Andes have been noted for the extraordinary size of 
 their chests. . . . Singers with no other exercise but singing acquire great 
 respiratory power and a remarkable increase in the dimensions of their chests.' 
 
 The exercises needed, therefore, should not only be such as develop 
 the muscles of the upper part of the trunk, but such also as increase the 
 volume of the respiratory movements. Among the latter would be placed, 
 so far as children are especially concerned, running, skipping, rapid limb 
 movements, and active exercises in the open air. 
 
 Many children are born with deformed and narrow chests which they 
 inherit from their parents ; in others the thorax has been distorted by rickets, 
 by lung affections, or by spinal disease. One potent factor in the production 
 of a narrow chest, outside these causes, is the hypertrophied tonsil. 
 
 It is anomalous to press a child to take exercises requiring vigorous 
 respiratory movements when enlarged tonsils so block up the opening into 
 the air-passages as to prevent the free entrance of air. 
 
 The Selection of Exbkcises ACcoEDiNa to Individual Needs 
 
 Children 
 
 The physical training of children should be commenced early, should be 
 made as interesting as possible, and be represented in the main by what may 
 he termed scientific romping. 
 
 The exercises should be given whenever possible in classes. To set a 
 child to execute formal movements with dumb-bell or bar-bell when alone, 
 and to march with no one for company, is a little dismal. 
 
 The set exercises should not be too formal, and never be too long, and in 
 no instance should they be allowed to take the place of the ordinary outdoor 
 games of children. 
 
 Games which involve shouting should be encouraged, and a very promi- 
 nent position given to running, skipping, games with balls, and jumping. 
 The most rudimentary of all games, ' touch,' is one of the most excellent. 
 The upper limbs may be encouraged by such amusements as battledore and 
 shuttlecock and the lower by such a game as hop-scotch. 
 
 K E 2 
 
612 HYGIENE 
 
 The set exercises should take the form of what are Icnowii as Swedish 
 gymnastics, the vocal march, musical drill, aud the class exercises with 
 dumb-bell and bar-bell. 
 
 Children should avoid exercises of strength and, in the main, exercises of 
 speed. They are best suited for exercises which involve moderate endurance 
 and such as require no great mental effort to follow. 
 
 In the matter of gymnastic apphances there is little need of especial work. 
 The subject is considered in the description of gymnastic apparatus. The 
 principal of these, from the children's standpoint, are the climbing rope, the 
 inclined ladder, the vaulting horse, the parallel bars. 
 
 Girls and Women 
 
 The physical condition of a large proportion of the girls and women in 
 this country is quite deplorable, especially among the middle and upper 
 classes. A well-developed perfectly proportioned girl who is possessed of normal 
 muscular strength, who can walk naturally, and can carry herself with grace, 
 attracts attention. The WTctched physical state of a large proportion of 
 modern girls — especially of those who inhabit the large towns — is apt to be as- 
 cribed, not to a totally neglected education, but to the belief that growing girls 
 are always awkward, uncouth, and weedy. This beHef is not well founded. 
 
 The unfortunate girl is encouraged to be dull, to be prim, to be subdued, 
 to suppress the outbursts of pure animal spirits. She is more or less under 
 the curse of that detestable adjective ' lady-like.' She spends hours in an 
 ill-ventilated schoolroom and upon a piano stool, and the rest of her time 
 is occupied in eating and sleeping, in preparing lessons, in stooping over 
 needlework, and in taking formal walks with the governess. Her clothes are 
 probably a collection of hygienic errors. 
 
 It is not to be wondered that a girl so fostered is often a melancholy 
 specimen of her species. She may be highly educated and the mistress of 
 many accomplishments, she may be cultured and ' refined ' according to 
 the boarding-school standard, but she will at the same time be probably 
 more or less imfitted for the struggle of life and the mere circumstances 
 w^hich attend Uving. 
 
 There is something about the ' higher education ' of the modern girl 
 which is comparable to the manufacture of the finest Sevres china. The 
 result is beautiful from the designer's standpoint, but the cup is delicate ; it 
 cannot be used in daily hfe, and it must be kept in a cabinet. 
 
 A good digestion and an active liver are more useful in the battle of life 
 than a knowledge of advanced mathematics, and sturdy limbs and strong 
 hands are of more value to the mother of children than even decimal 
 fractions and a familiarity with irregular verbs. 
 
 The lady-like girl is encouraged to keep her hands ' fine,' to have them 
 compressed by gloves and protected from Hght, and to use them as little as 
 possible in order that she might produce the wan, feeble appendage wliich 
 constitutes the lady-like hand, and which is put to httle more use than to set 
 off a few rings. The face must be protected from the sun by sunshades 
 and veils, the pink and white complexion of the invahd must be imitated. 
 It would appear that the lady-hke are always dehcate, and a certain unobtru- 
 sive feebleness and flabbiness are signs of refinement. For use and influence 
 in the world, for a capacity to enjoy the purest pleasures of life, and as an 
 example of all the finest qualities of womanhood, no one among the 
 ' higher educated ' can compare with such an one the * Nut Brown Maid.' 
 The ballad of the ' Nut Brown Maid ' might well be engraved upon the wall 
 of every ' finishing ' school for young ladies. 
 
PHYSICAL EDUCATION 613 
 
 A neglected physical education produces a sorry object— a pale child 
 ■with a poking head, a narrow chest, an unshapely back, a shuffling or 
 mincing gait, and an ungainly carriage. She is without grace and with- 
 out the capacity for vigorous physical enjoyment. Her ankles and wrists 
 are clumsy, her complexion is dull, and if her circulation be bad — as is not 
 unusual — her sodden-looking purplish arms are covered with a fine down. 
 When she grows up to womanhood she finds herself unfitted for the duties 
 and responsibilities of a wife and mother. She has little strength to with- 
 stand the hardships of life and less capacity to enjoy its pleasures. She is 
 nervous, querulous, frail, and in more respects than one a poor creature. 
 Walking makes her tired, the sea makes her sick, the sun makes her head 
 ache, the wind makes her chilly, effort of any unusual kind reduces her to a 
 general wreck. The number of women who can travel without fussing and 
 knocking up, and who can climb a ship's side and make their way across a 
 heavy moor, and can, indeed, become companions to their husbands and 
 brothers in the milder of these outdoor sports is not considerable. 
 
 Younger girls may pursue the exercises named in dealing with the edu- 
 cation of children. Those who are a little older have an infinite variety of 
 healthy pursuits at their service — running, skipping, outdoor games of 
 all kinds, riding, skating, swimming, cricket, games with balls, archery, 
 tennis, climbing (in a moderate form), and certain exercises in the gymna- 
 sium. They should practise also such movements as develop the abdominal 
 muscles and should never neglect rowing. 
 
 Fencing in moderation is admirable ; a tendency to flat feet and weak 
 ankles may be met by such simple games as hop-scotch, by dancing (in the 
 open air), by learning Scotch dances and the hornpipe. Cycling may, I 
 think, be avoided, and I am under the impression that jumping may well be 
 dispensed with in girls who have passed the period of puberty. 
 
 For women such exercises as have been just detailed are open, with the 
 obvious modifications which their age and dispositions suggest. 
 
 Eowing is an admirable exercise for women up to almost any age. 
 
 The matter of clothing need only be briefly alluded to. It is of little use 
 to expect great good from walking exercises if tight boots are worn, with 
 high ankles and high heels. Corsets are an abomination, and rowing in 
 corsets forms a means of developing a pendulous abdomen and the conditions 
 which lead to hernia. 
 
 Lads 
 between fourteen and eighteen have almost every form of exercise and 
 physical recreation open to them. They should avoid exercises of strength 
 and feats of strength and exercises of extreme speed such as sprint running. 
 
 Adults 
 between eighteen and twenty-five have the whole of the joys of the athletic 
 world open to them, and if a man keep in training and in practice his period 
 of athletic life may be extended to thirty. 
 
 The Middle-aged and Elderly 
 must anticipate a progressive curtailment of their more active pursuits. 
 There remain, however, walking and all the milder forms of outdoor exercise 
 — riding, skating, cycling, and the use of the simpler gymnastic apparatus. 
 After thirty very few individuals indeed are capable of undertaking exercises 
 of speed without actual risk. 
 
BATHS 
 
 BY 
 
 W. HALE WHITE, M.D., F.E.C.P. Lox\d. 
 
 PHYSICIAN TO GUY'S HOSPITAL AND LECTURER ON MATEUIA MEDICA 
 AND THERAPEUTICS 
 
BATHS 
 
 HISTOEY OP BATHS 
 
 It is altogether beyond the scope of an article such as this to give a 
 history of baths. It would occupy too much space, and much of it would be 
 uninteresting to the medical reader. It will, however, be worth while to 
 give a short sketch of the history of baths so far as it concerns the student 
 of medicine. 
 
 Bathing is as old as the hills ; we find evidences of it far back in his- 
 tory, and at the present day savage tribes often attach great importance to 
 the curative effects of water. It is the custom of the Fiji women to take a 
 sea bath immediately after their confinement, with the object of accelerating 
 their recovery. The belief in the healing efficacy of water is sometimes so 
 strong that it becomes a religious belief. Thus we have the practice among 
 the Hindoos of bathing in the Ganges, or in the sacred lakes around their 
 temples ; we have the baths of purification ordered by the law of Moses, 
 and they are also required by the Talmud and by the code of religion of the 
 Mahommedans, The story of Naaman is another instance of the old belief 
 in the medicinal virtues of baths. In the traditions of the mythical period 
 of Greek history we find abundant allusions to the practice of bathing. 
 Later we find Hippocrates writing on the subject. In his work on ' Air, 
 Water, and Places,' that on the ' Usage of Liquids,' and also in that on 
 *■ Diet and Kegimen,' there are exact directions as to the employment of 
 water in therapeutics. Among the Eomans bathing reached great perfection : 
 for a full description of all their baths the reader may consult the article on 
 ' Baths ' in the ' Encyclopfedia Britannica,' Musa and Charmis were the two 
 physicians who most advocated the work of baths in medicine. Musa 
 attained great fame because Augustus recovered under his care, and part of 
 the treatment was the use of cold water thrown over the body after warm 
 baths and vapour baths. Under Charmis the use of cold baths became very 
 popular, and Pliny gives an account of the Eoman senators who sat 
 shivering after the cold baths which Charmis had ordered them. He em- 
 ployed them with such rigour that a controversy sprang up as to whether 
 they were really so useful as he contended, and for a time they were not 
 popular. Galen advocated cold baths, but condemned their excess, and 
 recommended the use of cold water to the head while the body was in a 
 warm bath. During the medical barbarism of the Middle Ages baths fell 
 into disrepute. 
 
 Among the Arabian physicians, Ehazes alone advocated cold baths, and 
 he advised their use in the treatment of small-pox, and used rose-water for 
 burns. It is not until 1699 that we again find baths attracting the attention 
 of the medical profession. In that year Floyer, an English physician at 
 Lichfield, pubHshed his book entitled ' An Inquiry into the Eight Use of 
 Baths,' and he recommended many applications of them. 
 
 In the eighteenth century the chief interest in baths was seen in Italy, 
 and one historian of the period states that ' all Italy is crazy on the subject 
 of cold water.' At the same time the Hahn family in Germany, consisting 
 of two brothers and a son, all strongly recommended the use of cold baths 
 
G18 HYGIENE 
 
 for various medical ailments. Joliann Sigismond Halin published a work 
 on the subject in 17-13. He applied cold water to the treatment of fevers, 
 especially small-pox, measles, and erysipelas, and used it also for many 
 chronic diseases. In Kussia, likewise, the use of baths became fashionable. 
 
 France also took up the movement. Surgeons, reviving the practice of 
 Ambroise Pare, advised the use of cold water for the treatment of wounds. 
 The most ardent French advocate for cold baths was Pomme, and he treated 
 all diseases of the nervous system by placing the patients in cold baths of a 
 temperature of 50° F., and leaving them there for from six to twenty-four 
 hours. His theory was that by the cold baths he infiltrated the nerves with 
 water, and thereby drove the disease out of them. 
 
 The first physician who treated the subject of baths at all scientifically 
 was Currie, of Liverpool, who, being on board ship with Dr. Wright, of 
 Edinburgh, when the latter had typhus fever, treated him by throwing 
 buckets of cold water over him. Dr. Wright was so much improved by this 
 treatment that Currie was led to adopt it in many forms of fever, amongst 
 others typhus, small-pox, scarlet fever, and measles. He was very successful, 
 and published in 1797 his medical reports on the 'Effects of Cold Water in 
 Febrile Maladies.' This book sold largely, for it soon reached its fourth 
 edition. The great merit of Currie's work was that he observed accurately 
 how much the application of cold reduced the symptoms of fever. Shortly 
 after him Giannini, in Italy, used cold water for fevers. He preferred the cold 
 bath, while Currie had used cold affusions. 
 
 In 1789 Vincent Priessnitz was born in Silesia. He was of very humble 
 origin, and had no scientific knowledge. When about twenty he broke his 
 ribs, and he treated himself by the application of a cold water bandage. 
 The ribs healed, and he attributed the cure to the action of the cold water. He 
 then roamed all over the country treating human beings and animals by 
 cold water in a most haphazard manner, quite irrespective of the maladies 
 from Avhich they might be suffering. The peasants attributed his success to 
 sorcery, but, anyhow, he became immensely popular, and the little village of 
 Greifenberg, where he settled down, soon became a town full of hotels to 
 accommodate the thousands who came to be treated by him. The Austrian 
 Government appointed a medical commission to examine the subject, and 
 they reported favourably upon the treatment of certain diseases by baths, 
 and thus, although Priessnitz was an ignorant quack, he became the means 
 of bringing the subject of baths before the medical profession. He amassed 
 an immense fortune, but left no record of any scientific value. 
 
 From that time till now such an impetus was given to the subject that 
 baths have become very popular. It is true that between about 1825 and 
 1860 there was a temporary lull in some branches of the subject ; but since 
 the latter date the work of scientific men, such as Liebermeister, Jiirgensen, 
 and others, has thoroughly elucidated the subject. In the following pages we 
 shall see that, although baths are of great value, their importance has been 
 immensely overrated by all sorts of impudent quacks, who issue pretentious 
 advertisements designed to attract persons to particular bathing establish- 
 ments in which these quacks have a pecuniary interest. 
 
 FORMS OF BATHS 
 
 Baths are divided into general and local. A general bath is one in which 
 the whole body, save the head, is immersed. A local bath is one in which 
 only some part of the body is immersed. The local baths which have re- 
 
BATHS CIO 
 
 ceived names are the occipital bath, the elbow bath, the hand bath, the sitz 
 or hip bath, and the foot bath. Sometimes the word ' bath ' is used even when 
 no part of the body is immersed ; thus we have a shower bath. Closely allied 
 to baths are those local applications of water in which it is made to play 
 upon a part of the body in the form of a spray or douche. There are a great 
 many varieties of these at all bathing establishments. The water is generally 
 projected upon the part with considerable force, and its temperature is 
 capable of being modified while the douche is in action. Sprays and douches 
 have been named either according to the part of the body to which the water 
 is applied, such as the rectal douche, the vaginal douche, or according to the 
 shape of the stream that is ejected. There is no need to recapitulate all the 
 foohsh and fantastic names that have been thus applied. Water may be 
 locally applied to parts without actually coming in contact with them. It is 
 then solely used to produce local alterations in temperature. Leiter's coils 
 are an instance of its employment in this manner, and various sounds, elastic 
 bags, or catheters, through which cold or warm water is made to circulate, 
 have to be used in the treatment of diseases of the uterus, vagina, rectum, 
 and urethra. Water in the form of ice is applied to parts by being placed in 
 india-rubber bags which are placed on the skin ; Chapman's spinal ice-bag 
 and the ordinary ice-bag applied to the head for concussion are instances of 
 its use in this manner. Lastly, it is frequently applied locally by means of 
 cloths, flannels, or lint, rinsed out in hot or cold water, which then forms 
 either a compress or a fomentation. If these are covered over with gutta- 
 percha, they retain the heat of the body, and so act like a poultice. 
 
 The Physiological Action of Baths consideeed according to 
 
 THEIR TeMPEEATUEE 
 
 We shall have under this heading to consider the influence upon the body 
 of (1) indifferent baths or those in which a healthy person feels neither hot 
 nor cold ; (2) cold baths or those in which a healthy person feels cold, and 
 (3) warm baths or those in which a healthy person feels warm. Popular 
 terms used for varieties of these will be mentioned under each heading. 
 Delmas gives the following table showing the temperature of water baths,, 
 which are named according to their temperature : — 
 
 Excessively cold . . 
 
 Very cold 
 
 Cold .... 
 
 Moderately cold or fresh 
 
 Slightly cold 
 
 Tepid .... 
 
 Warm .... 
 
 Ve/y warm . 
 
 Excessively warm 
 
 All people are not equally sensitive to the effect of heat and cold, so that no 
 precise classification can be given. 
 
 Indifpeeent Baths 
 
 Water is a very much better conductor of heat than air. From this it 
 follows that the indifferent temperature of water is much higher than that 
 of air. In a perfectly still atmosphere a naked person feels neither hot nor 
 cold if its temperature be somewhere between Ql^ and 77° F. ; but the indif- 
 
 Deg. Cent. 
 
 Deg. "Fahr. 
 
 Oto 6 
 
 32 to 42-8 
 
 7 „ 10 
 
 44-6 „ 50 
 
 11 „ 15 
 
 51-8 „ 59 
 
 16 „ 20 
 
 60-8 „ 68 
 
 21 „ 25 
 
 69-8 „ 77 
 
 26 „ 30 
 
 78-8 „ 86 
 
 31 „ 35 
 
 87-8 „ 95 
 
 36 „ 40 
 
 96-8 „ 104 
 
 41 „ 60 or 70 
 
 105-8 „ 140 or 15 
 
620 HYGIENE 
 
 ferent temperature of water varies for different persons from 88° to 98° F. 
 An indifferent bath, however long its duration, produces no alteration in the 
 bodily temperature. After it there is a pleasant feeling all over the body, 
 and there may be a slight loss of heat from the evaporation of the water that 
 has been left on the skin, and therefore it is always advisable that the bather 
 should dry himself quickly after the bath. There is no alteration in the 
 amoimt of urea and carbon dioxide subsequently excreted ; but the amount 
 of urme passed is said to be sometimes slightly increased. The pulse and 
 respiration are unaltered. Some authors state — but, as we shall see later on, 
 Avithout sufficient eAddence — that the skin is capable of absorbing water from 
 an indifferent bath. Water being so much denser than air, the total pressure 
 on the surface of the body must be considerably greater in a water bath than 
 in the air ; but we do not know of any effects that can be attributed to this. 
 An indifferent bath is often popularly called a warm bath, while one interme- 
 diate between warm and cold is spoken of as tepid. 
 
 Cold Baths 
 
 A cold bath abstracts heat from the body just the same as it would from 
 anything else with a higher temperature than the water of which it was 
 composed. But with healthy individuals taking an ordinary cold bath, the 
 loss of heat is not demonstrable by the thermometer, for the production of 
 heat is increased. In apparent contradiction to this statement is the fact 
 that MacHster (' The Nature of Fever,' 1887) has shown that cold has the 
 effect of abolishing, or at any rate greatly diminishing, the thermogenetic 
 function of muscle. But then it must be remembered that he used extreme 
 applications of cold. Thus in one of his experiments he found that when an 
 animal was cooled 16° C. the power of its muscles to produce heat when 
 stimulated was almost abolished ; but that when it was warmed up again to 
 the former temperature the thermogenetic power returned. Fred^ricq and 
 Quinquand (quoted by Dujardin-Beaumetz, ' Therapeutic Gazette,' Feb. 
 1888) state that in a healthy individual taking an ordinary cold bath, owing 
 to the contraction of the cutaneous vessels the blood, and consequently the 
 muscles, are but slightly cooled, and in such a bath the absorption of oxygen, 
 the ehmination of carbonic acid gas, and thermogenesis are increased. This 
 effect is most probably due to the stimulation of the skin by the cold water, 
 and the consequent reflex affection of the nerves which preside over the 
 thermogenetic function of muscle — that is to say, over the decomposition of its 
 thermogen, a term which has been applied to such substances in muscle as 
 produce heat. These same researches of Fredericq and Quinquand show that 
 if the application of cold be very prolonged, or if the cold be very great, 
 the absorption of oxygen and the excretion of carbon dioxide, which may be 
 taken as indications of the amount of thermogenesis, fall below the normal 
 point, thus really confirming Maclister's statements. The radiation of heat 
 must be considerably diminished by immersion in cold water ; but there is 
 no evidence to show how much it is affected by a bath. Probably all these 
 conclusions are not precisely applicable to a patient suffering from fever, 
 although, no doubt, in the main the same considerations will apply ; but 
 owing to the dilatation of the cutaneous vessels which so commonly exists in 
 fever, the blood is cooled and thus the thermogenetic function of the muscles, 
 owing also to their being likewise quickly cooled, is sooner depressed than in 
 health. But, even in a fever patient, the first effect of a cold bath is probably 
 at first to increase thermogenesis ; but soon the activity of this function de- 
 creases, and it may continue to be considerably depressed even for some time 
 
BATHS 621 
 
 after the patient is taken out of the bath. For a fuller account of the appli- 
 cation of a. cold bath for fever the reader is referred to the writer's ' Text- 
 book of General Therapeutics.' 
 
 The effect of a cold bath upon the actual temperature of the body has 
 been carefully studied by many observers. If the bath is moderately long 
 and not very cold, the bodily temperature remains constant because of the 
 balancing of the loss and of the production of heat. Liebermeister in 1859 
 showed that if the bath be very cold the internal temperature rises slightly. 
 For example, he found a slight rise of the rectal temperature was caused by 
 a bath of 86° F. lasting twenty-five mimutes. Jacob, Kemig, and others 
 have confirmed these results. In one experiment the temperature of the 
 blood rose as much as 3°"6 F. 
 
 Probably, however cold the bath, there is at first a shght rise of the 
 internal temperature ; but, if the water be very cold, this is too transient to 
 be noteworthy, and we get only a sinking of the whole temperature of the 
 body, both external and internal. The same effect may be produced by a 
 moderately cold bath if it be continued sufficiently long. Thus Jiirgensen 
 found that long-continued baths of a temperature of 60° F. usually caused a 
 rapid sinking of the temperature of the body. Liebermeister says that 
 most persons can bear baths of a temperature of 68° F. to 75° F. for, on the 
 average, twenty minutes before their temperature sinks below what it was 
 previous to the commencement of the bath. The fall of temperature is 
 naturally greatest on the surface and least in the interior and in the folds of 
 the .skin. For example, in one of Jacob's experiments the temperature of the 
 skin sank in a cold bath lasting sixteen minutes from 62°'6 to 48°*2 F., but 
 that of the axilla only sank 1° F. 
 
 After the discontinuance of a bath which was not sufficiently cold, nor 
 long enough to cause a fall of the bodily temperature, there is a short period 
 during which it falls a little lower than before the bath. This is called by 
 Liebermeister the primary after-effect. The slight rise of temperature which 
 succeeds this is called by Jiirgensen the secondary after-effect. The primary 
 after-effect is due in part to the fact that the cutaneous vessels which were 
 contracted during the bath rapidly dilate again when the bather leaves it, and 
 thus there is a greatly increased radiation of heat, the effect of which in coohng 
 the bodily temperature is augmented by the diminution of heat-production 
 which, as Liebermeister has shown, directly follows the leaving of the bath and 
 is probably to be looked upon as compensatory to the increased heat-produc- 
 tion which took place during it. The following figures from Leichtenstern 
 show the great loss of heat occasioned by a cool bath. He says, if we 
 observe in a man who is healthy and not unnaturally stout the loss of heat 
 which takes place in a bath of the duration of fifteen to twenty-five minutes, 
 it is found that in a bath of 93°"2 F. the loss of heat nearly corresponds with 
 the ordinary average loss ; in a bath of 86° F. it reaches twice, in a bath of 
 77° three times, in a bath of 68° F. more than five times the average loss. 
 
 Local withdrav^als of heat, such as partial baths and cold douches, have 
 the same effects, but to a less extent. 
 
 All authors are agreed that a cold bath greatly augments the tissue- 
 waste in the body. Braun says that the amount of carbon dioxide ex- 
 creted may sometimes be increased as much as from 300 to 500 per cent. 
 Eoughly speaking, this increase is proportionate to the increased production 
 of heat. Liebermeister found that in a bath of only 90°*3 F. the excretion 
 of carbon dioxide was shghtly increased, but with a bath of 64°-4 F. it 
 was increased to three times the normal amount. The increase in the 
 excretion of carbon dioxide continues for a short time after the patient 
 
622 HYGIENE 
 
 leaves the bath. This is due in part at least to the fact that the increase in 
 excretion will continue to be evident for some httle time after the increased 
 production, which is the cause of the greater excretion, has stopped. Rohrig 
 and Zuntz have both of them shown by means of their experiments upon 
 rabbits that this increase in the excretion of carbon dioxide is accompanied 
 by a corresponding increase in the amount of oxygen taken in. 
 
 If the bath be so cold or so long that the temperature of the body begins 
 to fall, then the increased excretion of carbon dioxide gradually lessens, 
 till at last the amount excreted may be even less than it was before the bath. 
 Here also the amount of oxygen taken in decreases proportionately to the 
 diminution in the amount of carbon dioxide excreted. These variations in 
 the excretion of carbon dioxide are directly caused by the variations in 
 the production of heat, which, in their turn, are due to a greater or less 
 decomposition of thermogen, owing to the reflex stimulation of the nerves of 
 skin by contact with the cold water. Experiments made upon animals give 
 the same results as observations upon man. Many observers have worked 
 at the subject. Euhrig and Zuntz and Colasanti used rabbits, Finkler 
 employed guinea-pigs, and Duke Carl Theodore used cats. 
 
 A local application of cold produces precisely the same effects upon tissue- 
 metamorphosis as does a cold bath, but they are less in amount. 
 
 Leichtenstern says that excretion of urea is not altered by a cold bath 
 unless the temperature of the body is considerably lowered by it. The fol- 
 lowing authorities agree with him in this statement. Liebermeister found, 
 in experiments he made in 1859, that cold baths produced no alteration in 
 the amoimt of urea excreted, if the patients remained on the same diet. 
 Senator experimented with dogs, and came also to the conclusion that a 
 diminution of the external temperature produced no change in the excretion 
 of urea. Voit's experiments gave a like result. Probably, if the cold be very 
 great or very prolonged, the excretion of urea may be altered. Braun simply 
 states that a cold bath increases the excretion of it, without saying at what 
 temperature this takes place. 
 
 Turning now to the effects of a cold bath upon circulation and respira- 
 tion, the most obvious result is that the cutaneous vessels will be contracted. 
 If the bath be excessively long continued or very cold this contraction is suc- 
 ceeded by a paralytic dilatation, and this accounts for the bluish-red colour of 
 the skin so often seen after a cold bath. The contraction of the vessels is 
 probably due in part to a reflex and in part to the direct stimulus of the cold 
 water. Observations upon the rate of the pulse are very discordant, some 
 authors stating that it is quickened, others that no alteration takes place, and 
 others that it is slowed. The explanation of these discrepancies is that at first 
 the pulse is slightly accelerated, but subsequently it is retarded. The primary 
 quickening is often but slight, or it may be unobservable ; probably it is due 
 to the rise in the blood-pressure caused by the contraction of the cutaneous 
 vessels. The exact temperature necessary to cause a marked slowing is not 
 the same for all persons. Kirejeff could not detect any effect upon the pulse 
 after a bath of 71°"6 to 75°'2 F., but Kemig found that a regular diminution 
 of pulse-rate was produced by baths of a temperature of 95° F., and Draper 
 found after a cold bath lasting an hour and composed of water at a temperature 
 of 74° F. that there was considerable slowing of the pulse, which retardation 
 remained for some little time after the cessation of the bath. Probably the 
 blood-pressure rises a little when the cutaneous vessels are contracted by the 
 cold bath and falls when they are paralytically dilated, but we have no 
 experiments in proof of this. 
 
 With regard to respiration, the first effect of a cold bath is that the 
 
BATHS 623 
 
 bather, if the water be sufficiently cold, gasps and experiences a sensation 
 of difficulty of breathing. At the same time he feels a shiver run all over 
 him. This is accompanied by a long-drawn inspiration which may deepen 
 into a sigh. Then there is a sudden stoppage in respiration, due in part to a 
 spasmodic closure of the glottis. This, however, soon passes off and there is 
 a prolonged expiration and, in extreme cases, a groan. With healthy persons 
 it takes a considerable degree of cold to produce these effects, which are wit- 
 nessed after much less cold in children and sickly people. The frequency of 
 the respirations is at first a little greater, but soon they are considerably 
 slowed. This is true both of man and animals. Leichtenstern says that all 
 observations agree that the amount of air respired increases in a cold bath. 
 In one of his experiments a rabbit was immersed in water at a temperature 
 of 53°"6 F. During a bath of fifteen minutes the volume of air breathed 
 was increased 25 per cent. It is clear that if the number of respirations is 
 diminished their depth must be enormously increased. 
 
 After a little while the condition of goose-skin is seen ; this is probably 
 due to a contraction of the arrectores pili, 
 
 Weber has shown that very cold baths diminish the cutaneous sensi- 
 bility. This, however, does not apply if the stimulus be a warm substance, 
 for the colder the skin the greater is its power of distinguishing warm bodies 
 when they are applied to it. If, however, the degree of cold be moderate, 
 cutaneous sensibility is at first raised, and stimuli which ordinarily could 
 hardly be felt are painful. The property possessed by cold water of stimu- 
 lating the peripheral nerves is frequently used to accelerate the return of con- 
 sciousness in persons who have fainted. After a cold bath of short duration 
 there is, as is well known, a feeling of well-being and exhilaration. The 
 bather is refreshed. The mental faculties are cleared, the muscles seem 
 strengthened, and there is a desire for both muscular and mental work. 
 
 If the bath be very cold, or the bather stop in it a long while, the bladder 
 and rectum may be emptied reflexly and he may experience partial paralysis 
 of the muscles of the body, together with a general sense of weariness and 
 mental weakness. 
 
 The feehng of well-being which follows a short bath is usually explained 
 by the fact that, owing to the contraction of the cutaneous vessels, there 
 will be more blood in the internal organs and consequently a more rapid 
 removal of waste-products from them, and an increased stimulus to their 
 functional activity. On the other hand, if the cold be sufficiently prolonged 
 to paralytically dilate the cutaneous vessels it is obvious that, owing to there 
 being less blood in muscles and other internal organs, waste-products will 
 accumulate in them, and the amount of blood in them will be diminished. 
 The feeling of warmth after leaving the bath is to be attributed to tbe re- 
 actionary dilatation of the cutaneous vessels, which is subsequent to their 
 contraction. If there is no feeling of warmth it may be that either the 
 vessels of the skin have not contracted, or that they have dilated because they 
 are paralysed by the cold, or that, having contracted, they will not expand 
 again on leaving the bath. There are many individual peculiarities in these 
 respects. Bathers must always be careful not to take a bath so prolonged, 
 or of a temperature so low, as to prevent the reactionary dilatation of tlie 
 cutaneous vessels. A patient feels the after-effects of a cold bath more if he 
 has just had a hot one and vice versa. 
 
 Cold baths are largely used for the exhilaration that ensues, which can be 
 increased by rubbing with a rough towel. If they are taken constantly, the 
 alternate contraction and relaxation of the vessels train them to contract 
 easily, and therefore habitual bathers are not very liable to catch cold. 
 
02-1 HYGIENE 
 
 We v;ill now discuss some of the more important effects of the local ap- 
 plication of cold water by means of local baths, douches, sprays, &c. Our 
 most accurate information on this subject is due to the labours of Winternitz. 
 He used the plethysmograph and showed that when cold was locally applied 
 to any part — for example, the middle of the arm — there was a diminution in 
 the size of the vessels, of the quantity of blood, and a lowering of temperature 
 in the parts beyond the point of application, and the reverse in the parts 
 behind. One of "Winternitz's figures showing the great diminution in the 
 size of the radial pulse-wave after the application of cold to the arm is very 
 striking. Its amplitude is diminished by quite three-quarters. Other figures 
 of plethysmographic tracings show most markedly the diminution in the size 
 of the arm produced by immersion in cold water. When the area of the body 
 to which the cold is applied is considerable, the local vascular contraction is 
 accompanied by a universal dilatation of the vessels all over the rest of the 
 body. This fact Winternitz has proved with the plethysmograph, by which 
 instrument he obtained a tracing which showed most markedly the increased 
 volume of the arm due to a sitz bath at a temperature of 4G°*4 F. The tem- 
 perature of the axilla was at the same time raised. 
 
 The local application of cold has another important efl'ect, namely, that 
 it produces a reflex contraction of distant vessels. Naumann separated all 
 the parts of the posterior extremity of a frog so that the limb remained at- 
 tached to the body only by the sciatic nerve. He then applied cold to the 
 leg, and observed that if the cold were moderate there was a diminution in 
 the capillary circulation of the mesentery, but when the apphcation of cold 
 was prolonged there was a dilatation of the vessels. SchuUer, in the same 
 way, showed that the application of a moderate degree of cold caused contrac- 
 tion of the vessels of the pia mater ; the application of an extreme degree 
 caused dilatation of the same vessels. Franck, working with the plethysmo- 
 graph, showed that the application of cold water to one hand produced a de- 
 crease in the size of the vessels of the other. These experiments have been 
 confirmed by Mosso. All these effects are undoubtedly reflex, and some ex- 
 periments of Winternitz are very interesting as showing an association be- 
 tween different parts of the body. Thus he found that the application of 
 cold to the feet influences chiefly the intra-cranial circulation, cold to the 
 thighs affected chiefly the pulmonary circulation, and cold to the back especi- 
 ally influences the circulation of the vessels of the nose. This fact is very 
 interesting in connection with the popular practice of putting a cold key down 
 the back for epistaxis. These reflex effects of cold applied to the skin in 
 contracting deeply placed vessels have many applications in medicine : thus 
 we apply an ice-bag to the head for concussion, and ice-poultices to the chest 
 for pneumonia. Some find a cold sitz bath useful for diarrhoea. Another 
 reflex effect of the local application of cold to the skin is that at first the 
 pulse and respiration are increased in frequency, afterwards they diminish. 
 If the cold be very severe there may be much palpitation and gasping. 
 
 Cold feet can be warmed by the reaction after a cold foot bath, and men- 
 struation can in some women be checked by the same means. The many 
 applications of cold for various medicinal purposes, chiefly to reduce in- 
 flammation, hardly come within the scope of the present article. It is said 
 that cold baths increase the number of the red blood-corpuscles and the 
 amount of haemoglobin in them, and for this reason some advise cold baths 
 for anaemia. 
 
 Cold baths are contra-indicated in all who do not react rapidly after them. 
 Therefore they should not be ordered for the very young, the very old, or 
 those debilitated by disease, nor for those in whom there is already congestion 
 
BATES 625 
 
 of the internal organs, unless it be with the object of producing a reflex local 
 efifect. All baths, save those which are temperate, are forbidden for persons 
 with disease of the heart. 
 
 Warm Baths 
 
 It is usually supposed that the temperature of the human body remains con- 
 stant even if the variations of that of the surrounding medium are extreme. 
 But we usually forget the important influence exercised by our clothes in 
 maintaining the average temperature of the body. It has been undoubtedly 
 shown that, if we consider the naked body, its temperature is constant only 
 within certain narrow limits. To speak more accurately, we ought to say the 
 temperature of the folds of the skin, for most of the observations have 
 reference only to the axillary temperature. Senator observed the effect of 
 undressing in a room and found that it reduced the axillary temperature 
 slightly, even when the room was of the usual temperature of 60° F. or 
 between 58° and 70° F., and he comes to the conclusion that the axillary 
 temperature is only constant if the body is naked when the surrounding tem- 
 perature does not differ more than from 14° to 18° F. from that of the body. 
 Winternitz has performed a number of experiments and has shown that 
 alterations in the temperature of the air only affect the temperature inside 
 the clothes slightly, unless the alteration be about 50° F., so that, although 
 in ordinary life man's temperature is constant, that is due not -only to the 
 adjustment of it but also to the fact that the temperature next to his skin is 
 fairly constant. We have already seen that a cold bath will alter the tempera- 
 ture of the body, and from what one has just learnt we are not surprised to 
 find that a warm bath will do the same. 
 
 A warm bath, therefore, increases the temperature of the body both by 
 imparting heat to it and preventing the loss of warmth from it. Zuntz and 
 Eohrig put a dog for eighteen minutes in a bath at 107° F. ; the animal's 
 temperature rose 4° F. ; and Seiche and Schmelkes have obtained similar 
 results. Liebermeister found that if the water of the bath was at the tem- 
 perature of the body, so that no heat was given off, the temperature in the 
 axilla rose. Thus, in one experiment, in 55 min. the temperature rose from 
 99°"5 to 102° F., and in another similar experiment it rose from 99° F. to 
 102°-4F. Hosier observed in hot baths of 104° to 111°-2F. that the tem- 
 perature of the mouth would rise to 101°*6F. After the bath is over the 
 temperature gradually falls again. It may be urged that in Turkish and 
 Eussian baths the temperature of the body does not rise in anything like 
 the proportion of that the above figures indicate, but it must be remembered 
 that a hot-water bath prevents loss of heat from the body almost completely, 
 for there can be no loss by evaporation, none by conduction, and very little, 
 if any, by radiation. In a vapour bath, unless the air is saturated, evapora- 
 tion of the sweat from the skin-evaporation can take place. Still, the tem- 
 perature of the body does rise considerably in a vapour bath. Bartels gives 
 an experiment in which in a vapour bath of 127°*4 F. the temperature of 
 the body rose in 10 min. from 100° -4 to 104°-5 F. On another occasion, in 
 a vapour bath of 123°'8 F. the temperature of the same individual rose from 
 100°-4 in 8 min. to 103° F. in 30 min. to 107° F. Many other observers have 
 published results which accord with these. In a Turkish bath the tempera- 
 ture of the body may rise a little in the hotter rooms, but owing to the rapid 
 evaporation of the sweat the rise is very slight. Kemig has attempted to 
 find out whether there is any alteration in the production of heat in a patient 
 taking a hot bath, but the experiments are not sufficiently accurate and we 
 have no evidence on the matter. The exhalation of carbon dioxide and water 
 VOL. I. s s 
 
G2G HYGIENE 
 
 from the lungs is increased, but because that of the oxygen is diminished the 
 total quantity of respired air is lessened. According to Braun, if a warm bath 
 be very long continued the blood becomes thick and dark-coloured and there 
 is a continuance of the greater oxidation at the expense of both the blood and 
 the tissues. ^Yinteruitz states that the changes in the urea are the same in 
 both hot-water and vapour baths, but that the increase in the excretion of it 
 in water baths is less than it is in vapour baths. Naunyn found that in dogs 
 whose temperature had been artificially raised the amount of urea excreted 
 was augmented, and Bartels observed that in men who took warm baths the 
 amount of urea was increased. Schleich made a most careful series of ex- 
 periments in which a uniform diet was maintained througliout. On certain 
 days the temperature was raised to 103° F. by means of hot baths : on these 
 days there was always an increase in the urea excreted ; this continued for 
 some days after the bath, but gradually decreased, and at last was succeeded 
 by a compensatory decrease of urea. 
 
 It is said that there is an immediate momentary fall of the pulse in the 
 hot bath ; but this is very quickly followed by an acceleration. In one of 
 Kemig's experiments a bath at 99° F. caused a rise in the pulse from 80 to 
 96 beats, but a cold shower bath brought it down rapidly to about 74. The 
 rise in the rate of the pulse is always proportionate to the rise in the bodily 
 temperature. Owing to the wide dilatation of the cutaneous vessels there is 
 a fall in the blood-pressure of internal organs. 
 
 Many experiments have been made with regard to the influence of warm 
 baths upon respiration, and, although some of them are discordant, all the 
 more accurate show that the respirations increase in frequency proportion- 
 ately to the rise in the temperature of the body. This is true not only of 
 hot-water baths but also of hot-air and vapour baths. 
 
 After leaving the bath the skin is red and the secretion of sweat is 
 enormously increased. Hot water liquefies the fatty secretions of the skin, 
 and is a better solvent than cold ; therefore it cleanses the body more 
 thoroughly. 
 
 After a hot bath the secretion of urine is lessened, just as after a cold bath 
 it is increased. In certain cases it is said to be slightly increased for a short 
 time after even a warm bath, but it is doubtful whether in such cases there 
 is really an increase in the secretion ; probably the general muscular relaxa- 
 tion produced by the warm bath gives rise to a desire to void the urine. 
 Koloman Milller counted the drops of urine leaving the ureter from shaved 
 dogs. When the dog was put in water at 104° F. the secretion of urine 
 was decreased ; but under the mfluence of cold water it was increased by from 
 5 to 11 drops in each five minutes. It is said that after a prolonged warm 
 bath the uruie is rendered alkaline, but Leichtenstern and Eohrig deny this. 
 The following summary of the chief effects of warm baths is taken from the 
 writer's ' Text-book of General Therapeutics.' 
 
 Owing to the dilatation of the cutaneous vessels blood is withdrawn from 
 the internal organs, and thereby their functional activity is depressed. This 
 explains many uses of hot baths ; one taken immediately before going to bed 
 has long been known to be a valuable remedy for insomnia. The soporific 
 effect of a warm bath has been Imown to cause the death of the bather. 
 Frequent warm baths are enervating. Great weariness of the muscles is 
 reheved by a hot bath, probably because by withdrawing blood from them it 
 lowers the activity of the processes going on in them. Napoleon, if possible, 
 always took one when he was unable to get a night's rest. Braun lays 
 considerable stress on the chemical changes in the tissues and the blood 
 that the rise of temperature produces, and some authors believe warm baths 
 
BATHS G27 
 
 to have an absorbing power over inflammatory products, but these matters 
 are very difficult of proof. 
 
 The effects are often not the same on different individuals, but for nearly 
 all persons the following propositions are true : — 
 
 Hot baths, like any other application of heat, soothe pain ; hence they are 
 useful for rheumatoid anthritis and colic, whether it be renal, biliary, or 
 intestinal. By bringing blood to the skin and lessening the amount in the 
 internal organs they relieve muscular spasm such as we find in stricture of 
 the urethra, colic, laryngismus stridulus, other forms of laryngeal spasm, and 
 infantile convulsions. In the same way they are of service in weariness from 
 muscular or cerebral activity, are soporific, and are useful in many inflam- 
 matory affections, as a cold, in the head. The subsequent increased perspira- 
 tion makes them of great value in the various forms of nephritis and in 
 anemia. Great care must be taken after a hot bath which has been given 
 to induce sweating to see that the patient is kept warm by being wrapped 
 quickly in a hot blanket and being put into a warm bed. If not, the cuta- 
 neous vessels soon contract, all the good of the bath is undone, and there 
 is no diaphoresis. 
 
 The same names are applied to local baths whether they are hot or cold. 
 
 We have seen that the local application of cold to a part causes contrac- 
 tion of the vessels and lowering of the temperature ; in the same way the 
 local warm bath causes a great dilatation of the superficial vessels of the part 
 and a local rise of the temperature of the skin. As a result of this dilatation 
 blood is withdrawn from distant parts, the size of the part to which the heat 
 is applied is increased, and when the warmth is withdrawn a copious local 
 perspiration takes place. Often as with cold so with heat, a reflex effect upon 
 the vessels of some deep-seated organ occurs. This is due to the stimula- 
 tion of the skin by the heat. For example, upon the application of warmth 
 to the chest not only the cutaneous vessels of the chest-wall but those of the 
 lungs and pleura immediately underneath the point of application, dilate. 
 The local hot baths most frequently used are the foot bath, which is very 
 •often used to withdraw blood to the lower extremities in a case of cold in the 
 nose ; and the sitz bath, which leads to dilatation of the pelvic vessels and 
 may, therefore, be used in amenorrhcea. A mustard bath is a local hot bath 
 to which from one to three ounces of mustard have been added to every 
 -fifteen gallons of water. 
 
 The Physiological Action of the Constituents op the Bath 
 
 There has for several years been a long and heated controversy as to 
 whether the constituents of a bath are absorbed by the skin. 
 
 Many have attempted to determine whether water was absorbed by the 
 skin. Some weighed the bather before and after the bath, others weighed the 
 water. Some concluded that the body gained in weight from the absorption 
 ■of water, others thought it lost weight in a bath, and others again could detect 
 no difference whatever. Observers have been even known to declare that a 
 bath increased the weight of the bather by pounds. In all these experi- 
 ments the most obvious fallacies — such as the evaporation of water, the 
 failure to dry the bather completely, and many others — were not guarded 
 against, and the whole of the experiments are, therefore, perfectly valueless. 
 Krause made a series of experiments upon the power of pieces of dead skin 
 to imbibe water, and because he found that, after a long time, it could absorb 
 water, certain people have jumped to the conclusion that the skin absorbs 
 water in a bath, quite forgetting the fact that Krause experimented with 
 
 ss2 
 
C28 HYGIENE 
 
 pieces of dead skin. Imbibition by the skin Avas tliouglit also to be proved 
 by the fact that if the arm were placed in a vessel containing- some salt in 
 solution and then in plain water, the latter was found to contain some of the- 
 salt, but no allowance was made for the fact that some of the salt might have 
 adhered to the hairs on the arm. Lastly, we need hardly point out that an 
 increased flow of urine after a bath is not, as some would have us believe, 
 any evidence whatever that water has been absorbed, for the variations in the 
 vasomotor condition of the skin are quite enough to account for it. There- 
 fore, we may conclude that tliere is no evidence that the skin can absorb 
 water from a. bath ; indeed, when we remember the oily condition of the 
 epidermis, covered as it is by sebaceous secretion, we should hardly expect 
 that it could take up any water. 
 
 Multitudes of experiments have been made with the object of showing 
 that any salts which are dissolved in the water are taken up by the skin. 
 The salt most frequently used has been chloride of sodium. Beneke and 
 Eohrig have shown most conclusively that this is not absorbed. The latter 
 observer carefully estimated the amount of chloride of sodium excreted by a 
 patient and then he gave a salt bath, of a temperature of 95° F., but could 
 detect no increase in the amount of the salt in the urine. 
 
 Many experiments have been made with salts of iron ; the most satisfac- 
 tory are those in which ferrocyanide of potassium was used, and all these 
 show that salts of iron are not capable of absorption by the skin. Experi- 
 ments with salts of lithium likewise gave negative results. Iodide of potas- 
 sium is a favourite salt for experimentation, as it is very diffusible ; many 
 experiments appear to show that this can be absorbed by the skin, but no- 
 guard has been made against the fallacy that it is very liable to be decom- 
 posed in the bath and that the free iodine thus given off, being volatile, may 
 be taken up by the lungs. The amount that it has been supposed the skin 
 might take up is not greater than may be accounted for in this Avay. Some 
 observers have put powerful drugs, such as opium, belladonna, digitalis, cor- 
 rosive sublimate, into the water, and have endeavoured, by observing whether 
 the patient was affected by them, to determine if they were absorbed by the 
 skin ; but all these experiments were so carelessly conducted that they are 
 valueless. If, therefore, we exclude substances which might have a powerful 
 chemical influence on the skin, and also those which are volatile and might, 
 therefore, be absorbed by the lungs, we see there is no evidence whatever that 
 the skin has any power of absorbing substances which are dissolved in baths. 
 
 Chrzonsczewsky has made some experiments which are so often quoted 
 that we must just refer to them. He shaved parts of animals and immersed 
 the shaved parts in baths containing various substances in solution. The 
 water of the bath was covered with oil to prevent evaporation. According to 
 Chrzonsczewsky, large quantities were absorbed, but we are not told whether 
 the animals were scratched or cut during the shaving, and the symptoms 
 produced were so severe that there is clearly an error somewhere. There is 
 no doubt that the skin can absorb small quantities of volatile bodies such as 
 iodine, but even in these cases the amount absorbed by the lungs is probably 
 much greater. Of course it is well known that some substances, such as 
 mercury, can be absorbed by the skin if they are rubbed in thoroughly. 
 
 The skin appears to absorb small quantities of certain gases that are 
 dissolved in the water of a bath, but, as just mentioned, this is probably to 
 be entirely explained by the fact that some of the gas is given off from the 
 bath and is taken up by the lungs and such of the skin as is not under water. 
 Chloroform, ether, hydrocyanic acid, carbon dioxide, carbonic oxide, and 
 sulphur dioxide are instances of gas that can be absorbed in this way. The 
 
BATHS G29 
 
 amount which can be taken up by the sldn is so small, in comparison with 
 the quantity that can be taken up by the lungs, that inhalation is always to 
 be preferred to cutaneous absorption. 
 
 It has been repeatedly stated that baths with a salt or gas in them have a 
 •stimulating effect upon the skin. This is, however, very slight — so slight 
 indeed that Leichteustern considers that its only effect is, to a small extent, 
 to influence the vasomotor effect of baths, so that the vascular dilatation 
 after a cold bath, and the vascular dilatation in a warm bath, are a little in- 
 creased if the bath contain a salt or gas in solution ; but he goes on to say 
 that this stimulating effect of the salt or gas is too small to influence the 
 frequency or depth of the respiration, or to modify the quantity of urine 
 passed after the bath, or to influence the quantity^of urea and carbon dioxide 
 ■excreted, or to alter the temperature of the body or the pulse-rate. In fact, 
 the influence of the gas or salt dissolved in the water is so slight that it may 
 be totally disregarded, and baths act chiefly by their temperature. 
 
 We have seen that no absorption takes place in a bath ; nevertheless, it is 
 probable that the superficial layers of the epidermis can to a slight extent 
 imbibe water, although so little is thus taken up that the effects of the imbi- 
 bition are inappreciable. 
 
 Leichtenstern calculates that probably 500 to 600 kilogrammes are in an 
 ordinary bath added to the atmospheric pressure of 15,450 kilogrammes on 
 the whole body. We, however, know nothing of any effects which can be 
 attributed to this action. 
 
 The electrical operations of a bath are involved in much obscurity. 
 Heymann and Krebs appear to be the most careful of those who have experi- 
 mented upon this subject. They found that all the mineral and gas contain- 
 ing waters, with the exception of sulphur ones, act positively when brought 
 in contact with distilled water ; that the highest degree of electrical relation 
 was caused by the presence of the gases in the water, the next degree by the 
 temperature of the water, and the third degree by the presence of salts. 
 The gases experimented upon were carbon dioxide, nitrogen, oxygen, and 
 sulphuretted hydrogen. The alterations due to temperature were to be 
 attributed to variations in the conductivity of the water. The gases contained 
 in water (except sulphuretted hydrogen) are the cause of their electro-positive 
 behaviour, for distilled water containing neutral or basic salts is towards 
 plain distilled water not electro-positive but electro-negative. The only infor- 
 mation we have upon the electrical reactions of the human body when in 
 water is derived from an experiment of Heymann's. A man was put into a 
 bath. One pole was placed in the bath water and the other on the man's 
 skin outside the bath. Ordinary water, and water containing carbon dioxide, 
 were both of them positive, wliile the body was negative ; but if sulphu- 
 retted hydrogen was dissolved in the water this was negative and the body 
 positive. It is not known whether these electrical variations have any effect 
 iipon the human body, nor is any use of them made in medicine. It is 
 quite needless to refer to the large amount of rubbish that has been written 
 on the subject of the electrical reactions of baths. 
 
 THE USES OP BATHS CONSIDEEED ACCOEDING TO THEIE 
 TEMPEEATUEE 
 
 We will now pass on to the consideration of the uses of baths, and in so 
 -doing we shall omit many of the applications which most writers on balneo- 
 logy describe. There is probably no disease for which baths have not been 
 
630 HYGIENE 
 
 recommended, but frequently those who advocate some particular form of 
 bath are pecuniarily interested m bathing-establishments, and a little exami- 
 nation shows that the bath cannot possibly have the beneficial effects at- 
 tributed to it. The uses of special kinds of baths will be described mider 
 separate headings. 
 
 Uses of Indifpeeent Baths 
 
 Baths in which the bather feels neither hot nor cold are used for cleansing 
 purposes and also for the mild exhilarating eti'ects that the bather feels on 
 leaving them, when he has rubbed himself quickly with a rough towel. No 
 time should be lost between the exit from the bath and the drying, whether 
 the bath be warm, cold, or indifferent, for the evaporation of the water from 
 the skin will cool the body. Directly after drying, the clothes should be 
 put on. No bath, whatever its temperature, should be taken immediately 
 after a meal. It is said that indifferent baths will cure mild functional 
 nervous diseases, such as slight cases of hysteria. Unfortunately, many 
 authors apply the term ' indifferent thermal waters ' to warm baths not con- 
 taining any important mineral constituent. 
 
 Uses of Cool or Cold Baths 
 
 The temperature of the water which can be used for baths varies im- 
 mensely for different people, but everyone can easily find for himself the 
 temperature which suits him best. It must never be so low as to prevent 
 the reactionary dilatation of the cutaneous vessels which ought to succeed 
 after a bath. For the same reason a cold bath must never be prolonged. 
 Directly upon leaving the bath the bather must rub himself thoroughly and 
 quickly with a rough towel to aid the cutaneous vascular dilatation, and it is- 
 particularly important that, in order to prevent any loss of heat, he should 
 dress quickly. We have already seen that after a cold bath there is a feeling 
 of exhilaration and warmth, the energy appears to be increased and the 
 mental faculties quickened. It is for these effects that a cold bath on getting 
 up in the morning forms part of the, daily life of so many Englishmen.- 
 Persons accustomed to cold baths are less liable to catch cold than those 
 who do not use them. Apart from their antipyretic effect, cold baths are 
 chiefly used for their stimulating effect. There are many hydropathic 
 establishments with admirable cold baths, and Avhere all the accessories, 
 such as rest, fresh air, and regular meals, aid the hydrotherapeutic treat- 
 ment. Patients sufl'ering from general exhaustion, due mostly to mental 
 overwork, strain and anxiety, are often conspicuously benefited by a stay at a 
 hydropathic establishment. Very often patients of this class suffer from, 
 chronic indigestion, which is frequently alleviated by a visit to one of these 
 places ; therefore, when the two conditions are combined, such treatment is 
 particularly suitable. Certain cases of hypochondriasis and hysteria are 
 sometimes brilliantly cured, but in others no good whatever results. We 
 have already indicated the principles which should guide us in the local 
 application of cold. Cold hip baths have been found useful m impotence, 
 spermatorrhoea, amenorrhoea, and prostatitis. The cold douche is largely 
 used as a local stimulant, and will reflexly affect the circulation in the organs 
 under the point of application. 
 
 The places best known for their cold baths are Ilkley, Ben Ehydding, 
 Malvern, Wemyss Bay, Forres, Crieff, Nassau, Boppard, Godesberg, Wies- 
 baden, Alexandersbad, Liebenstein, and Rigi Kaltbad. 
 
BATHS 631 
 
 The Antipyretic Uses of the Gold Bath. — The use of the cold bath in 
 fever has, during the last twenty-five years, revolutionised our ideas con- 
 cerning the treatment of febrile disorders. It is a very wide subject, and 
 therefore in an article of this nature only a brief account of it can be given. 
 Fuller information may be found in Liebermeister's ' Antipyretics ; ' Von 
 Ziemssen's ' Handbook of General Therapeutics,' vol. ii. Eng. Trans. 
 1885-6 ; Currie's ' Medical Eeports on the Effects of Water, Cold and 
 Warm, as a Eemedy in Fever and Febrile Disorders when applied to the 
 Surface of the Body or used internally,' 4th edit. London, 1805 ; Tripier 
 and Bouveret's 'La Fievre typhoide traitee par les Bains froids,' Paris, 
 1886 ; Fismer, ' Kaltwasserbehandlungbei der acuten Crouposen Pneumonie,' 
 Deutsch. Arch. f. Klin. Med. 1873 ; and the writer's ' Text-book of General 
 Therapeutics,' London, 1889. From the latter the following account is 
 chiefly abstracted. 
 
 The first person to put the treatment of fevers by cold water upon a 
 scientific basis was Currie, the first edition of whose work appeared in 
 1797. The great merit of Currie's work over that of his predecessors is 
 that he took the temperature of his patients. Giannini in 1805 gave an 
 account of the employment of cold for fever. The use of this method, how- 
 ever, died out, until it was again brought under the notice of the profes- 
 sion by Brand in 1861, and since then many authors have discussed the 
 subject. 
 
 In considering the action of a cold bath in fever we have to remember 
 that the thermic mechanism of the body consists of three parts : (1) a 
 thermogenetio, by means of which heat is produced by changes going on 
 chiefly in the muscles which are the main thermogenetic organs of the 
 body ; this function is presided over by the central nervous system, probably 
 that part of it which is in the neighbourhood of the great basal ganglia. 
 (2) A thermolytic mechanism which presides over the loss of heat. Its 
 chief parts are the cutaneous vasomotor system and the sweat-glands. It is 
 likewise under the control of the central nervous system. Heat is lost from 
 the skin by conduction, radiation, and evaporation. (3) Lastly, there is a 
 thermotaxic mechanism whose function is to maintain the balance between 
 the thermogenetic and the thermolytic. This mechanism must clearly be 
 nervous. In fever the production of heat is enormously increased. Those 
 pathologists who believe in the value of antipyretic methods of treatment 
 assume that the pyrexia of fever is harmful, and that by diminishing it we 
 benefit the patient. 
 
 From the above it is seen that the possible modes of action of a cold 
 bath are very numerous. It is clear that a cold bath must directly abstract 
 heat. Maclister has shown that cold diminishes the thermogenetic activity 
 of muscle, and it is almost certain that a cold bath acts in this way, es- 
 pecially if the cutaneous vessels are dilated, as they often are in fever, for 
 then cold blood is quickly carried to the muscles. It is true that when a 
 fever patient is put into a cold bath the rectal temperature at first rises a 
 little. This is soon succeeded by a fall, and it may be explained either by 
 the fact that the water interferes with the loss of heat by evaporation and 
 radiation, or that there is at first a slight, temporarily increased thermo- 
 genesis which is an abortive attempt to compensate for the direct abstraction 
 of heat by the cold water. After the patient has been taken out of the bath, 
 the temperature continues to fall, probably because for a short time the 
 activity of thermogenesis remains depressed. There are many ways of em- 
 ploying cold to reduce fever. Simple sponging with cold water calls for no 
 description. 
 
032 HYGIENE 
 
 The Cold Bath. — This is undoubtedly the most efficacious. It is best 
 apphed by means of a long bath placed at the end of the bed, so that both 
 are in the same straight line. The patient with a blanket over him is lifted 
 in a sheet, and by it lowered into the water while the blanket remains over 
 the top of the bath. To lift him out, several persons place their hands under 
 him and the wet sheet is left behind ; he is put back into bed and a sheet or 
 simple blanket is thrown lightly over him. The temperature of the bath 
 should be between 58° and 08° F. or warmer, if that of the patient be high. 
 The point of fever heat at which he should be bathed varies with the disease. 
 The inmiersioil should last about ten minutes, for the quantity of heat which 
 at the end of this time can be further abstracted is small, as the rapidity 
 with which heat is given from a hot body to a cold one increases with the 
 diii'erence of temperature between the two. Hence short bathings frequently 
 repeated are much more potent than long ones. The temperature of the 
 bath may be higher in children, for they present a much greater projjortional 
 surface from which to withdraw heat. In private practice there is some- 
 times much inconvenience in arranging the bath. This difficulty may be 
 surmounted by raising the head of the bedstead a few inches and thereby 
 makii:ig an inclined plane of it. Under the patient a large macintosh sheet 
 is placed and it is extended over a bank of pillows on either side, a gutter is 
 made in the macintosh at the foot of the bed so that cold water poured in 
 at the head will run out at the foot, where it is caught in some suitable 
 vessel. The pillows at the side may be so high that the patient lies in a 
 stream of running water. 
 
 The Tepid Bath gradually cooled. — This, first employed by Ziemssen, is 
 applied thus : The patient is put into a bath the temperature of which is 
 from 9° to 10° F. below that of liis body. Cold water is then gradually poured 
 in till, after ten or fifteen minutes, the temperature of the bath has fallen to 
 about 08° F. He remains in from twenty to thirty minutes, when generally 
 severe shivering or chattering of the teeth begins. He is then quickly moved 
 back to a bed which has been previously warmed. This method is not 
 nearly so potent as the cold bath, and is more difficult to carry out ; never- 
 theless it has two great advantages — namely, that it is more comfortable to 
 the patient ; and that it can be used for cases in which, from the condition 
 of the heart, there is any likelihood that the shock of the cold may be too 
 severe. 
 
 The Cold Affusion. — This is the method Currie used, for he threw cold 
 sea-water over those whom he treated. The patient should be placed in an 
 empty bath, and water at about 00° F. thrown over him ; this is done for 
 about five minutes. The cold affusion is now but rarely used, for the reduc- 
 tion of temperature caused by it is but slight, and the shock is so great as 
 to be extremely disagreeable. It is absolutely forbidden when there is any 
 sign of cardiac mischief. Possibly some of Currie's good results may be set 
 down to the fact that he used salt water, which is more stimulating than 
 fresh. 
 
 The Cold Pack. — The naked patient is wrapped in a sheet, four folds 
 thick, which has been wrung out in cold water, and is carefully placed between 
 the thighs and axillfe. It is often recommended that the sheet should not 
 quite reach to the feet, because of the difficulty of throwing it over them. 
 Outside it a blanket is thrown. In five or ten minutes the patient is removed 
 from between the folds of the sheet and a fresh one is substituted. This 
 is more easy if there are two beds. The process is repeated four or eight 
 times, and even then is not so powerful as a cold bath. 
 
 Ziemssen and Immerman give the proportionate efficacy of the cold affusion, 
 
BATHS G33 
 
 ■a series of four cold packings, the gradually cooled bath and the cold bath, 
 at 1 : 2 : 3 : 4. Cold baths administered to febrile patients in the latter part 
 ■of the evening and in the night cause a more durable and a greater reduc- 
 tion of the temperature than those given in the daytime, and the reduction 
 produced by a nocturnal cold bath is greater than would be the difference 
 between night and day temperatures in the same case if it had not been 
 treated by a cold bath. This is due no doubt in part at least to the fact that 
 at night the temperature is naturally falling, and that it is easier to reduce a 
 falling temperature than a rising one. We thus learn that baths ought 
 to be continued through the night. 
 
 We will now briefly consider some of the diseases for which the cold 
 bath treatment has been employed. 
 
 Typhoid Fever. — The cold bath has been very much used for this disease, 
 and in many institutions it was the routine practice. Numerous statistics 
 have been published, and they all show that the mortality from typhoid 
 fever since the introduction of the cold bath is much less than it was before. 
 Murchison calculates that the mortality of typhoid fever when treated on the 
 expectant plan is 17*45 per cent., and Jaccoud says it is 19'28. Brand puts 
 the mortahty after the introduction of the cold bath treatment at 6 per cent. 
 If we contrast the treatment at the same hospital before and after the intro- 
 duction of the cold bath we find the contrast very distinct. Liebermeister's 
 statistics show that at Basle from 1854 to 1864 mortahty under the expect- 
 ant symptomatic treatment was 18-1 per cent. The mortality in subsequent 
 years among those who were treated by the cold bath was 11*2 per cent., and 
 many other statistics might be quoted all showing a great fall in the death- 
 rate. In Germany it is usual to fix the temperature at which a bath should 
 be given at 102°-2 F. Many place it at 108° F. In order to get the best 
 results possible the case must be consistently treated from the beginning. 
 
 Fever patients come under treatment more frequently late than early, yet 
 among twenty patients whose deaths are recorded by Tripier and Bouveret, in 
 seven the treatment had been begun after the twentieth day, in ten between 
 the eighth and sixteenth days, and in three only during the first week. One 
 can never say what course a case of typhoid fever will take, and therefore it 
 is very important to begin the treatment early, even if the case appear to be 
 mild. 
 
 It might be thought that cold bathing would increase the frequency of 
 complications, especially bronchitis and pneumonia ; but this is not the case. 
 Hoffmann and Liebermeister estimate that, while the complications from 
 severe lung mischief anions: those treated on the expectant method was 20 
 per cent., among those treated by cold baths it is only 7-7 per cent. 
 
 Experience has shown that epistaxis, pleurisy, and albuminuria are not 
 contraindications to the treatment. Of course perforation of the intestine 
 and peritonitis are absolute contraindications to treatment by cold baths, and 
 so is intestinal hemorrhage, if it be severe, but not if it be mild. If the 
 patient suffers from severe heart disease, or if he is very collapsed when first 
 seen, a cold bath should not be given. Pregnancy, menstruation, phthisis, 
 bronchitis, obesity and old age are not in themselves contraindications. 
 
 Cold baths not only reduce the temperature ; they also benefit the patient 
 in other ways. At first the contact with the cold is very disagreeable, but 
 after a short time he feels much more comfortable, the pulse and respirations 
 fall in frequency, and often delirium disappears, and all those symptoms 
 which make up the typhoid condition are ameliorated. 
 
 The application of cold does not shorten the fever, it only diminishes its 
 intensity. Eelapses are said to be more frequent after the administration of 
 
634 HYGIENE 
 
 the cold bath than they are if the patient is treated without them, but the- 
 difiference is so shght as to be of no practical consequence. It is probable 
 that ultimately some of the newly introduced antipyretic drugs, such as anti- 
 februi, will, to a large extent, replace the use of the cold bath for typhoid 
 fever. 
 
 Typhus Fever. — This was the malady for which Currie principally used the 
 cold-water treatment. Jiirgensen and Brand have also used it with good 
 results. 
 
 Pneumonia. — Of late years the treatment of pneumonia by cold water, 
 externally applied, has come much mto vogue, especially in Germany. 
 Liebermeister states that by it the mortality from this disease in the hospital 
 at Basle has been reduced from 2o-3 to IG'8 per cent. Fismer contrasts 230 
 cases treated before the introduction of the cold bath with the same number 
 treated by it, and finds the deaths to be sixty in the first series, as against 
 thirty-eight in the second. He fixes the temperature at which the bath 
 should be given at 102°-2 F. It does not appear that the disease is curtailed 
 by it. 
 
 Bheumatic Fever.— The majority of cases of this disease are so adequately 
 treated by compounds of salicyhc acid, or by the acid itself, that they da 
 not require to be treated by cold baths ; but the case is different with rheu- 
 matic hyperpyrexia. Here the temperature rises so rapidly that most ener- 
 getic means must be adopted the moment there are any symptoms of the 
 onset of hyperpyrexia ; by this means the most desperate cases can be saved. 
 The Clinical Society appointed a committee to investigate the subject, and 
 they reported that out of the cases which were not bathed only one, in which 
 the maximum temperature exceeded 106, recovered ; but of the cases which 
 were bathed fifteen, or five-eighths of the total in which the maximum ex- 
 ceeded 106, recovered. In six out of eleven fatal cases which were not bathed^ 
 the maximum was under 106 ; but in only three out of twenty-two fatal bathed 
 cases was it so low. A perusal of the report of the committee will show that 
 energetic cold water bathing is most necessary in all cases of rheumatic 
 hyperpyrexia. 
 
 Cold-water bathing has been employed for almost every disease accom- 
 panied by a rise of temperature. Thus it has been used for scarlet fever, 
 small-pox, measles, pleurisy, meningitis, and erysipelas. 
 
 Uses of Wabm Baths 
 
 These are most used for washing, and for that purpose are far more effi- 
 cacious than cold, because they aid the removal of the fatty secretions of the 
 skin. 
 
 Their uses need not occupy us long, for they have been already indicated in 
 the account given of the physiological action of warm baths. They are used 
 for two main purposes, dilatation of the cutaneous vessels, and the soothing 
 of pain. 
 
 Dilatation of cutaneous vessels is required whenever we wish to abstract 
 blood from internal parts. Thus a warm bath promotes sleep if taken im- 
 mediately before going to bed, as it withdraws blood from the brain; but it is, 
 of course, essential that the patient should go to bed immediately after the 
 bath and be thoroughly wrapped up so that the dilatation may be maintained. 
 General weariness is relieved by a hot bath, because it withdraws blood from 
 internal organs and thus rests them. A hot bath is a favourite remedy for 
 a cold and other mild inflammatory disorders, for the reason that the blood 
 is diverted from the inflamed part to the skin ; here, also, it is important 
 
BATHS 635 
 
 that the patient should after the bath at once go to bed and be wrapped in 
 blankets to maintain the dilatation. Warm baths are largely used for the 
 diaphoresis which occurs after them ; for this reason they are employed in 
 Bright's disease. In this malady, as it is very desirable to maintain the heat 
 for some time, a hot pack or hot-air bath is often to be preferred to a hot- 
 water bath. To maintain the diaphoresis after any of these the patient should 
 be well wrapped in hot blankets. 
 
 Warm water is largely used to relieve pain and muscular spasm, as we 
 see in its application for renal, intestinal, and biliary colic, and also in the 
 fact that a catheter can often be passed successfully in a warm bath, when 
 previously all attempts had failed. A warm bath is a very frequent remedy 
 in infantile convulsions. Certain skin diseases in which there is a large 
 accumulation of scales, such as psoriasis, very chronic eczema, and exfoliative 
 dermatitis are improved by warm baths. For these maladies Hebra so ar- 
 ranges a bath that a patient can remain in it for days at a time, without 
 getting out to relieve either the bowels or the bladder. The water is pleasantly 
 warm and is kept at a constant temperature. Tepid baths allay irritation, 
 and are, therefore, of use for the itching of prurigo, the tingling of erythema, 
 and the itching of jaundice. Dujardin-Beaumetz recommends them for use 
 during the eruptive stage of small-pox. For the above purposes they are 
 generally employed at the patient's own house, but there are a large number 
 of bathing-places whose reputation rests solely upon their warm baths. They 
 are chiefly used for chronic rheumatoid arthritis, and to absorb chronic in- 
 flammatory products. Leichtenstern says : ' It is a matter proved by multi- 
 plied observation that the products and residue of chronic inflammation and 
 hyperplexia of tissue can be favourably influenced by the use of warm baths. 
 The old and deserved reputation of thermal springs in the treatment of chronic 
 rheumatism of joints and muscles, of rheumatic contraction and false anky- 
 losis, of the effects of past attacks of gout, can hold its own even against the 
 extreme of scepticism. The methodic use of thermal waters often improves 
 and cures certain chronic skin affections, ulcerous processes of the skin, badly 
 granulating torpid wounds, fistulas and caries of bone, cicatrices distorting 
 the skin, muscle, sinew and joint exudations that remain behind after luxations, 
 fractures, and gunshot wounds, and which often interfere so much with the 
 function of the parts affected. Chronic exudations also after pleurisy, pelvic 
 peritonitis, perityphlitis, peri- and parametritis may at times be ameliorated 
 by warm baths. Undoubtedly certain affections of the nervous system are 
 suitable for the employment of thermal baths, for they are often appropri- 
 ately employed in various forms of old stationary cerebral, spinal, peripheral 
 and taxic paralyses ; further, in various neuralgias and hypersesthesias, in 
 some forms of hysteria, neurasthenia, and hypochondria ' (Leichtenstern ; 
 Ziemssen's 'Handbook of General Therapeutics'). 
 
 The following is a list of the more important places which are celebrated 
 for their warm springs. The figures indicate the temperature in degrees 
 Fahrenheit : — 
 
 Aix-les-Bains (90-114) ; Badenweiler (79-100) ; Baden (114-120) ; Bath 
 (107-117); Bormio (95-104); Brussa (55-170); Buxton (82); Dax 
 (116-140) ; Gastein (95-138) ; Hammam-Mescontin (115-203) ; Hammam- 
 E'Hira (107-110) ; Leukerbad (102-124) ; Neris (118-125) ; Pistyau 
 (86-104) ; Plombieres (66-158) ; Pfaffers (104) ; Ponte Seraglio (100-129) ; 
 Eagatz (96) ; Eomerbad (93-99) ; Schlangenbad (80-89) ; Teplitz (105-118) ; 
 Warmbrunn (96-107) ; Wildbad (93-102). 
 
 The innumerable local uses for warmth hardly fall within the scope of this 
 article. Hot sitz baths have already been mentioned. 
 
C36 HYGIENE 
 
 USES OF BATHS CONSIDEKED ACCORDING TO THEIR CONSTITUENTS 
 
 In this place we will only consider natural baths, and they are quickly 
 dismissed, for, as has already been pointed out (p. G27), there is no evidence 
 whatever that substances dissolved in water to such a slight extent as they 
 are found in natural waters have any effect whatever. All the good that 
 patients profess to obtain from such baths is to be attributed either to the 
 temperature of the water or to the accessories, such as fresh air and good 
 diet, which are met with at the bathing establishments. For example, in 
 olden days the most marvellous effects were attributed to sulphur baths, but 
 it is interesting to note that at the most celebrated places possessing sulphur 
 baths the water was warm and the diseases for which sulphur baths were re- 
 commended were just such as would be benefited by warm baths. The con- 
 sideration of the constituents of the bath naturally leads us to sea-bathing. 
 
 Sea Baths 
 
 The following table will show that these fall under the heading of cold 
 baths. The mean summer temperatures of the sea are : — 
 
 Degrees Falirenheit 
 
 Mediterranean 71"6 to 80'6 
 
 Atlantic (European) 68 „ 73"4 
 
 German Ocean 60'8 „ 64-4 
 
 Baltic Sea 59 „ 62-6 
 
 The following table of the composition of ocean water shows that chloride 
 of sodium is the only important constituent : — 
 
 Chloride of sodium ......... 25*1 
 
 Chloride of i^otassium ........ '5 
 
 Chloride of magnesium 3-5 
 
 Sulphate of magnesium ' . . 5-78 
 
 Sulphate of lime -15 
 
 Carbonate of magnesium ........ -IS 
 
 Carbonate of lime . . . . . . . . . '02 
 
 Carbonate of potassium ........ '23 
 
 Iodides and bromides ........ traces 
 
 Organic matter traces 
 
 Water 964-54 
 
 Total . 1000-00 
 
 The composition of sea water in various parts of the world is as follows, 
 the quantity of salts being expressed in parts by weight in 1,000 : — 
 
 Dead Sea 227-69 
 
 Mediterranean at Marseilles 40-7 
 
 South Atlantic 36-4 
 
 North Atlantic 35-97 
 
 Pacific 34 
 
 Indian Ocean 33-86 
 
 English Channel 32-35 
 
 German Ocean 29-0 
 
 Black Sea 15-9 
 
 Baltic 5 to 9 
 
BATHS C37 
 
 We have, therefore, to deal with a cool bath consisting of a strong solution 
 of common salt. To avail himself of the bath the patient must live at the 
 sea- side, and it must be taken in the open air and its water be constantly 
 moving. 
 
 We have already seen that a cool bath is a stimulant, that it produces a 
 feeling of exhilaration and strength, that the faculties are quickened, and that, 
 within certain limits, it conduces to maintaining a healthy condition. All 
 the virtues of an ordinary cool bath are intensified in a sea bath by the 
 motion of the water, and it is probable that the salt itself has some slight 
 stimulating effect ; but this is but small in comparison with the advantages 
 derived from the temperature of the water and its movement. The sea air 
 is, no doubt, a powerful factor in aiding the robust health often attained by 
 persons living in towns when they come to the sea-side for sea-bathing. 
 
 It is difficult to name any diseases which are specially benefited by sea- 
 bathing. It helps to maintain the health of the healthy, and it is particularly 
 serviceable in restoring to health those who are pale, anemic, and wasted, 
 and those who are convalescent from any serious disease. Those weak, sickly, 
 sallow creatures so often seen among the poorer inhabitants of towns are 
 usually regenerated by a course of sea-bathing. They regain their colour, 
 they put on flesh, and their strength is restored. These who are usually 
 said to be scrofulous are much benefited by sea-bathing. 
 
 Weakly individuals should only take one sea-bath a day. It should 
 always be before 1 p.m., and is best taken about two hours after breakfast. 
 The bather should not stay in the water more than five minutes, if he cannot 
 swim, and not more than ten minutes if he can. He should dry and dress 
 quickly on leaving the water. Before breakfast is a good time for the healthy 
 to bathe, and immediately after a meal is a bad time for anyone to take any 
 sort of bath. If the bather is overheated from exertion, a sea bath, or, in 
 fact, any kind of bath, should be taken at once, if it be taken at all, before 
 the body begins to cool. 
 
 Turkish Bath 
 
 There may be found in Lane's ' Modern Egyptians ' a very good account 
 of a Turkish iDath as it is used in Eastern countries, which shows that it is 
 pretty much the same as our Turkish bath. Therefore I shall only mention 
 briefly the points in connection with an ordinary Turkish bath. 
 
 The bather is, first of all, required to take off his boots, and he is then 
 shown into the first room, which is a large room with couches and chairs 
 placed all round it, and usually with a fountain of water in the centre. The 
 temperature of this room is generally about 60° F., and it is, in the best baths, 
 tastefully decorated. Here the bather undresses and wraps a cloth round 
 his loins. He then goes to the first hot room, the temperature of which is 
 110-120° P., and here he sits or lies for some time. This room is tiled or 
 made of marble, and, if the bather lie down, he lies on a marble couch with 
 a small pillow under his head. He stays here for about half an hour whiling 
 away the time talking and reading, during which some take a glass of water 
 or lemonade to drink. After he has been a little while in this room he 
 u.sually begins to sweat profusely. The next room to which he goes is the 
 same in structure as the first hot room. Its temperature is higher, usually 
 about 150° degrees. Here the bather remains for a shorter time than in the 
 first hot room, and during his stay he sweats still more. He may proceed 
 to other hotter rooms, the number and temperature of which vary at different 
 baths. In some there are three more, the temperature of the hottest being 
 
C38 HYGIENE 
 
 fron: 250° to 300° F. ^Yllcn the bather lias left the hotter rooms he goes 
 back to the first hot room, where he is thoroughly kneaded and shampooed 
 all over. The shampooer massages all the muscles and rapidly moves the 
 chief joints. The arms are usually first done, then the legs, and lastly the 
 trunk. This being finished, the bather goes to the washing-room, where he 
 is lathered all over, and the lather is washed off with warm or cold water 
 which is thrown over him. Some then take a cold plunge bath, while others 
 prefer a cold douche. The next stage is to return to the dressing-room, 
 where the body is lightly dried and the bather sits, well wrapped up in a 
 large towel, for half an hour or so, during which time he can smoke and 
 drink a cup of coffee. He then dresses and the bath is over. This is the 
 usual course of the proceeding, but there are many variations. Sometimes 
 a cold douche is taken immediately upon entering the first hot room, some- 
 times the hot rooms are taken in a different order to that mentioned above, 
 the most usual variation being that the bather goes first into the hottest room 
 and then gradually passes through the others. 
 
 The most obvious effect of the hot air is that it produces a great increase 
 in the perspiration, which literally runs down the body. There is, at the same 
 time, considerable hypertpmia of the skin. The sweat evaporates very fast and, 
 therefore, the temperature of the body does not rise as much as it otherwise 
 Avould, and it is also kept down by the evaporation of the pulmonary aqueous 
 vapour. Those who drink plenty of water naturally sweat more than those 
 who do not. Some before going into the hot rooms contract the cutaneous 
 vessels by throwing cold water over themselves. The respiration and pulse 
 are both quickened and there is some loss of weight. Many persons complain 
 considerably of cardiac palpitation in the hottest rooms. The follomng 
 table, compiled from Frey and Heiligenthal's ' Luft- und Dampf bader,' shows 
 some of the effects of a Turkish bath : — 
 
 Condition before the bath : — 
 
 Weight, 66,150 grammes ; pulse, 72 ; respiration, 15 ; axillary temperature, 
 36°-9 C. ; rectal temperature, 37°-7 C. 
 In a room at a temperature of 50° C. 
 At the end of 10 minutes : — 
 
 Pulse, 94 ; respiration, 17 ; axillary temperature, 37°'l C. ; rectal temperature, 
 37°-7 C. 
 At the end of 15 minutes the sweating began. 
 At the end of 20 minutes : — 
 
 Pulse, 104 ; respiration, 18 ; axillary temperature, 37°"5 C. ; rectal temperature, 
 37°-8 C. 
 At the end of 30 minutes : — 
 
 Pulse, 104; respiration, 18; axillary temperature, 37°'7 C. ; rectal temperature, 
 37"-9 C. 
 The patient then went to a room at 65° C. 
 At the end of 5 minutes : — 
 
 Pulse, 110; respiration, 19 ; axillary temperature, 38° C; rectal temperature, 
 38° C. 
 At the end of 10 minutes there was very profuse sweating. 
 At the end of 15 minutes : — 
 
 Pulse, 120 ; respiration, 19 ; axillary temperature, 38°-5 C. ; rectal temperature, 
 38°-3 C. 
 At the end of 20 minutes there was considerable discomfort : — 
 
 Pulse, 125 ; respiration, 20 ; axillary temperature, 38"^-7 C. ; rectal temperature, 
 38°-4 C. 
 The patient then went to rest in the cooling-room. 
 At the end of 5 minutes : — 
 
 Pulse, 95 ; respiration, 15 ; axillary temperature, 36°-0 C. ; rectal temperature, 
 37°-7 C. 
 
BATHS C39 
 
 At the end of 10 minutes : — 
 
 Pulse, 80 ; respiration, 15 ; axillary temperature, 36°"7 C. ; rectal temperature, 
 37°-7 C. 
 At the end of 20 minutes : — 
 
 Pulse, 72 ; respiration, 15 ; axillary temperature, 3G'^-8 C. ; rectal temperature, 
 37°-7 C. 
 Weight of the body after the bath, 65,100 grammes. 
 Loss of weight in the bath, 960 grammes. 
 
 The urine for the whole of three days before the bath was briglit yellow. Its daily 
 averages were that 1,567 cubic centimetres were passed, which gave 25*7 cubic centimetres 
 to each kilogramme of body-weight. The specific gravity was 1018-8. The urea was 
 45*47 grammes, which gave 0"688 to each kilogramme of body-weight. The uric acid was 
 0-633 gramme, which gave '009 gramme to each kilogramme of body- weight. 
 
 The urine for the whole day of the bath was red, clear, without sediment, and strongly 
 acid : 950 cubic centimetres were passed, which gave 14*5 cubic centimetres to each kilo- 
 gramme of body-weight. The specific gravity was 1027. The urea was 39-90 grammes, 
 which gave -604 to each kilogramme of body-weight. The uric acid was -860 gramme, 
 which gave -013 to each kilogramme of the body-weight. 
 
 The authors give other experiments, but as the above is a typical one 
 there is no need to refer to others. It shows us very well the rise in the 
 pulse, respirations, and temperature in the bath, and also that soon after its 
 cessation these have returned to normal. There is some difference of opinion 
 about the alteration in the amount of urea. According to Bartels and 
 JSFaunyn, the excretion of it is slightly increased, but the careful experiments 
 •of Frey and Heiligenthal show that this is not so during the bath, for it 
 decreased from 45*47 grammes as a daily average before the bath to 39*9 
 grammes during the day of the bath. Their experiments seem so careful 
 that we may probably conclude that they show the effect of a Turkish 
 bath is to make the urine dark in colour, strongly acid, scanty, of a high 
 specific gravity, with a diminution in the quantity of urea and an increase in the 
 quantity of uric acid. These experimenters, however, go on to say that some 
 time after the commencement of a series of baths, even as late as the second 
 day, there is a slight increase in the amount of urea passed, and more 
 uric, phosphoric, and sulphuric acids are excreted so long as the baths con- 
 tinue. It will be noticed how soon after the bath the pulse respiration and 
 temperature returned to normal, and also that there was a considerable loss 
 of body- weight. Manensein gives the limit as from a quarter of a pound to 
 two pounds, but the writer has known a man lose five pounds in a bath of 
 an hour and a half's duration. 
 
 Oertel has made a series of experiments, with the object of determining 
 the relative value of the various means we possess of producing diaphoresis. 
 They are not altogether satisfactory, for it is a very difficult matter to com- 
 pare things so different and to have similar conditions of experiment in each 
 case. He, however, comes to the conclusion that mountain climbing is by far 
 the most powerful means that we possess of increasing the excretion of water 
 by the skin and lungs, and that the next most potent, but more uncertain, 
 method is the subcutaneous injection of pilocarpine, then a Turkish bath, and 
 last of all in its efficacy comes a vapour bath. 
 
 Bearing in mind what we have said about the physiological action of the 
 hot-air bath, it is not difficult to see its uses. In the first place, it is, owing 
 to the rubbing of the skin, thoroughly cleansing ; any excess of fatty matter is 
 rubbed off, so that subsequently the bather's skin is in a much more healthy 
 condition than it was previously. The shampooing and massage cause a 
 feeling of comfort and strength after a bath. The alteration in the condition 
 of the urine, such as the increase of uric acid, the primary diminution and 
 subsequent increase of urea, the loss of body-weight, the large amount of 
 
CiO HYGIENE 
 
 perspiration, all show that Turkish haths must modify the metabolism of the 
 body, and must also be powerful excretory agents. These circumstances 
 probably explain the fact that they are of great use in aiding the absorption 
 of old inflammatory products, such as those due to syphilis, chronic rheu- 
 matism, rheumatic myalgia, and gout. Massage alone is useful in these 
 aflec'tions, but still more is the Turkish bath valuable, for it combines mas- 
 sage with other aids to absorption. For the same reason those who have 
 been chronically poisoned by lead or mercury usually derive benefit from a 
 course of Turkish baths. Sciatica and neuralgia are also among the diseases 
 for which they are to be advised, for all the factors of a Turkish bath will aid 
 recovery. The profuse diaphoresis renders them valuable for those suffering 
 from the chronic urannia of chronic Bright' s disease, and Frey and Heilig- 
 enthal do not forbid them in these cases, even if the heart is hypertro- 
 phied, provided that there are no other contraindications. The fact that 
 they cause a loss of weight has led to their being largely used by the cor- 
 pulent. No doubt they are of use to those who have not sufficient strength 
 of mind to diet themselves, but dietetic treatment for obesity is much more 
 valuable than a course of Turkish baths. If care be taken not to get a chill 
 on leaving the bath, a Turkish bath will often cure a cold in the head, and 
 patients sufi'ering from slight bronchitis with abundant expectoration find 
 themselves alleviated by one. 
 
 They should be absolutely forbidden to those who have valvular disease 
 of the heart or aneurysm, and must be taken with great care by the very 
 old and by those in whom there is any reason to suspect a fatty heart. 
 
 Local hot-air baths are chiefly used as a means of producing diaphoresis 
 in Bright's disease. A cradle- is put over the patient while he is in bed, 
 over this the bed clothes are throA^-n, and under the cradle a lamp is 
 placed. The clothes are so arranged as to prevent the exit of the hot air, 
 and such parts of the patient as are under the cradle are soon heated to such 
 a heat that profuse perspiration results. This method is very efficacious and 
 is commonly used. It is not, however, quite so much in vogue since the 
 introduction of pilocarpine. 
 
 A form of Turkish bath which the patient can use in his own house is 
 sold. It consists of an apparatus so arranged that when he is sitting on a 
 chair a large cloth, which is fastened tightly round the neck, falls down 
 over the chair to the ground, so that the whole of the patient except the 
 head is contained in it. A lamp is placed under the chair and the cloth 
 is securely fastened, so that no air has access from the outside. The air 
 inside becomes very hot and profuse diaphoresis takes place. This form of 
 bath is not nearly so comfortable as an ordinary Turkish bath, and has the 
 great disadvantage that it is not possible to easily regulate the temperature 
 in it. 
 
 Hot Vapour or Eussian Bath 
 
 This form of bath is rarely used by the English, but it is met with in 
 many foreign cities and bathing establishments. As probably many of my 
 readers are unacquainted with it, I quote the following description of a Eussian 
 bath from Kohl's ' Eussia : ' — The passage from the door is divided into two 
 behind the checktaker's post, one for the male, one for the female guests. 
 "We first enter an open space, in which a set of men are sitting in a state of 
 nudity on benches, those who have already bathed dressing, while those whO' 
 are waiting to undergo the process take off their clothes. Eound this space 
 or apartment are the doors leading to the vapour rooms. The bather is 
 ushered into them and finds himself in a room full of vapour, which is sur- 
 
BATHS 641 
 
 rounded by a wooden platform rising in steps to near the roof of the room. 
 The bather is made to he down on one of the lower benches and gradually 
 to ascend to the higher and hotter ones. The first sensation on entering 
 the room amounts almost to a feeling of suffocation. After you have been 
 subjected for some time to a temperature which may rise to 145° F. the 
 perspiration reaches its full activity and the sensation is very pleasant. 
 The bath attendants come and flog you with birchen twigs, cover you with 
 a lather of soap, afterwards rub it off, and then hold over you a jet of ice- 
 cold water. The shock is great, but is followed by a pleasant feeling of great 
 comfort and of alleviation of any rheumatic pains you may have had. In 
 regular establishments you go after this and lie down on a bed for a time 
 before issuing forth. But the Russians often dress in the open air, and 
 instead of using a jet of ice-cold water go and roll themselves in the snow. 
 
 The physiological effects of such a bath are much the same as those of 
 Turkish baths, and the differences will easily be gathered when we remember 
 that, owing to the saturation of the air of the chamber with moisture, the 
 sweat cannot evaporate. Thus high temperatures that are comfortably 
 endured in a Turkish bath cannot be borne in a Russian bath. The tem- 
 perature of the bather, however, tends to rise much more rapidly in the 
 vapour bath than in the dry-air bath. To give an instance, Bartels has seen 
 the temperature of the rectum of a man of 51 kilogrammes in a vapour bath 
 of 127°-4 F. rise in ten minutes from 100°-4 to 104°-5 F. In a vapour bath 
 of 12B°*8 F. the temperature of the same individual rose from 100°'4 in eight 
 minutes to 103°, and in thirty minutes to 107°. The pulse and respiration are 
 increased in frequency, as indeed they always are by any form of hot bath. 
 
 Frey and Heiligenthal have carried out a series of experiments with the 
 hot-vapour bath, and as an example we will quote those performed upon the 
 same patient as were those quoted in the description of the Turkish bath. 
 After three days of the daily administration of a Turkish bath, there were 
 three days during which no bath was taken, then there were three days 
 during which a Russian bath was taken daily. The air was saturated with 
 vapour and the temperature of the bath was 113° F. The averages of the 
 urine for the three days preceding the bath were 1,683 c.c, or 25*5 c.c. 
 to each kilogramme of body-weight. The specific gravity was 1,021. The 
 urea was 52-68 grammes, or "783 gramme per kilogramme of the body- 
 weight. The uric acid was '858 gramme, or -013 gramme to each kilo- 
 gramme of body-weight. 
 
 Before the bath : — 
 
 Weight of body, 65,800 grammes ; pulse, 72. 
 
 Eespiration, 17 ; axillary temperature, 36°-9 C. ; rectal temperature, 37°-7 C. 
 After five minutes in the vapour room :— 
 
 Pulse, 94 ; respiration, 19 ; axillary temperature, 37°-l C. ; rectal temperature,^ 
 37°-7 C. 
 After 10 minutes in the vapour room : — 
 
 Pulse, 110; respiration, 20; axillary temperature, 38° C; rectal temperature, 
 37°-8C. 
 After 20 minutes in the vapour room : — 
 
 Pulse, 128 ; respiration, 22 ; axillary temperature, 39°-2 C. ; rectal temperature, 
 38°-0 C. 
 After 25 minutes in the vapour room : — 
 
 Pulse, 136 ; respiration, 23 ; axillary temperature, 39-6° C. ; rectal temperature, 
 38°-8 C. 
 The patient then left the bath and went into the cooling room. 
 After five minutes in the cooling room : — 
 
 Pulse, 74 ; respiration, 17 ; axillary temperature, 36° C. ; rectal temperature, 
 37°-9 C. 
 VOL. I. T T 
 
£42 HYGIENE 
 
 After 15 minutes in the cooling room : — 
 
 Pulse, 70 ; respiration, 17 ; axillary temperature, 3G°-7 C. ; rectal temperature, 
 37°-7 C. 
 After 30 minutes in the cooling room : — 
 
 Pulse, 70 ; respiration, 17 ; axillary temperature, 3C°-8 C. ; rectal temperature, 
 37°-6 C. 
 Weight of body after the bath, 65,000 grammes. 
 Loss of weight in the bath, 800 grammes. 
 
 Urine for the whole day red, clear, and very acid, 900 cubic centimetres, or 13'8 cubic 
 •centimetres to each kilogramme of body-weight. Specific gravity, 1027. Urea, 38*7 
 grammes, or '586 gramme per kilogramme of body-weight. Uric acid, '980 gramme, or 
 •015 gramme per kilogramme of body-weight. 
 
 This experiment shows us the rise of pulse, respiration, and temperature, 
 the diminution in the quantity of the urine, its higher specific gravity, the 
 diminution of the urea and the increase of the uric acid, and the loss 
 •of hody-weight. The pulse and temperature soon sank to a little below 
 what they were before the bath, and the respiration to exactly the same 
 as it was before the bath. During the two days immediately after the 
 bath the urine regained the condition it had before the bath, except that 
 the excretion of urea was decidedly greater than it was before the bath. 
 
 The Eussian bath is not so valuable in the treatment of disease as the 
 Turkish. The warmth, the stimulus of the shock of the cold water or snow, 
 and the stimulus of heating the body renders it useful for chronic rheumatism 
 and for the pain of neuralgia or sciatica. Also the warm moist air renders 
 it serviceable for such forms of dry bronchitis as require a moist exhalation. 
 As the sweating is not so abundant as in a hot-air bath, vapour baths will 
 not be so valuable to eliminate poisons from the system, nor so useful for 
 the chronic uremia of chronic Bright's disease. 
 
 Local hot- vapour baths, rigged up like a local hot-air bath, are some- 
 times used. A cradle is put over the patient and clothes over it. A steam 
 kettle is placed at the end of the bed and vapour is driven into the space 
 under the cradle. 
 
 Frey and Heiligenthal thus contrast the hot-air and the vapour bath. 
 In both the common sensibiHty of the skin and the sense of appreciating 
 between hot and cold objects are raised. In the Eussian bath the capa- 
 bility of the muscles to respond to faradic stimuli is increased, but their 
 strength as measured with the dynamometer is diminished. In the Turkish 
 bath there are no alterations in these respects, but with both forms of bath 
 there is after them a general feeling of well-being and strength. Moment- 
 arily on entering each there is a contraction of the cutaneous capillaries with 
 a consequent hard pulse and rise of blood pressure ; but immediately after- 
 wards, owing to the dilatation of the cutaneous capillaries, the blood pressure 
 sinks, the pulse rises, and the force of the cardiac contractions decreases. 
 During the stay in the hot room there is anaemia of the mternal organs, but 
 h}^erasmia of them after the cold douche. The respirations are increased 
 in fi'equency and the temperature rises. There is much sweating in the 
 Turkish and less in the Eussian bath. In both the urine is decreased, and of 
 high specific gravity. At first the excretion of urea is decreased, afterwards 
 it is increased. The uric acid is increased. 
 
 Othee Fobms of Artificial Baths 
 
 There is hardly any limit to the many varieties of artificial baths. The 
 following have at various times been used : Moor, peat, mud, and slime baths, 
 pine-leaf and various aromatic herb baths, such as hay, gentian, camomile. 
 
BATHS G43 
 
 juniper, and marjoram baths. Brine baths and sand baths have been used, and 
 the latter are now very popular. Among the follies of medicine are tan, bran, 
 malt, glue, soup, milk, whey, flesh extract, blood, fermented wine, horse dung, 
 guano, oak bark, starch, soap, corrosive sublimate, mineral acid, chloride of 
 calcium, iron, and sulphur baths. At some bathing estabhshments carbonic 
 acid gas baths are to be found, and at the present time much attention is 
 paid to baths of compressed and rarefied air. It is obviously unnecessary 
 to describe all these, but a short description will be given of the more popular. 
 
 Sand Baths. — The sand is dry and is evenly heated throughout to 
 between 116° and 125° F. The lower extremities are covered in it for a 
 depth of five or six inches, the abdomen and thorax for half an inch. The 
 cutaneous capillaries dilate, and a profuse perspiration breaks out. The 
 sweat cannot evaporate easily because of the sand, consequently the bodily 
 temperature soon rises considerably. The sand and sweat form a coating 
 to the body which has after the bath to be washed off. These baths are 
 useful whenever warmth and heat are required, and therefore they are used 
 for chronic rheumatism, chronic gout, and chronic Bright's disease. 
 
 Moor, Peat, Mud, and SlimeBaths. — Some years ago these were extremely 
 fashionable. They are made by mixing moor earth, peat, mud, or slime with 
 water till the specific gravity of the mixture is about 1*2 or 1-3. The slime 
 used is the deposit of organic matter found in rivers. They are always 
 used warm, and any value that they may have depends not upon their con- 
 stituents but upon their temperature. Plain warm water would do equally 
 well. As an instance of the effect of a mud bath we may quote one of 
 Kisch's experiments in which he found that a mud bath, the temperature of 
 which varied between 100° and 104° F., quickened the pulse eight or ten 
 beats, but in the course of two hours it became normal. The respirations 
 were quickened and the axillary temperature was raised about 3° F. These 
 baths are chiefly used for chronic rheumatism. 
 
 Pine Leaf Baths. — To make these, a distillate and decoction made from 
 the leaves of pine trees is added to water, but there is no evidence that it is 
 of any value. Probably the efficacy of these baths depends entirely upon 
 the temperature at which they are taken. 
 
 Brine Baths. — A brine bath should contain 2 to 3 per cent, of common 
 salt, that is, about 18 to 27 lb. to every hundred gallons of water. These 
 baths act in the same way as ordinary salt water. 
 
 Mustard Baths are prepared by adding ^ to 1^ lb. of mustard to every 
 100 gallons of hot water. It is usually added to a local bath used to the feet 
 for the cure of a cold in the head. 
 
 Compressed-Air Bath 
 
 This consists of a strong metal chamber circular in shape and quite air- 
 tight. It is generally comfortably furnished with chairs and a table. When 
 the patient is in it, air can be pumped in till the pressure is raised to the 
 desired point. A full description of such a bath will be found in the ' British 
 Medical Journal ' for April 18, 1885, by Dr. C. T. Williams. There is one 
 at the Brompton Hospital in London, one at Ilkley, one at Ben Ehydding, 
 and there are several on the Continent. 
 
 An increase of pressure of f to f of an atmosphere is usually employed. 
 Anything beyond this is unnecessary, and is liable to produce disagreeable 
 symptoms. The patient at first experiences noises in the ears and a sense of 
 obstruction and pain in the tympanic cavity. These symptoms are due to 
 the fact that the air can pass much more easily along the external auditory 
 
 T I 2 
 
GU HYGIENE 
 
 meatus than up the Eustacliian tuhe, and consequently the membrana tympanf 
 is bulged mwards. If the patient swallow frequently they soon pass off, but 
 only to return again when he comes out of the pneumatic chamber. General 
 sensibility and the senses of smell, taste, and touch are impaired. Some persons 
 feel sleepy. All observers are agreed that the compressed-air chamber in- 
 creases the amplitude of the respirations and also the pulmonary capacity. 
 According to Von Vivenot, it is about 3 per cent., but Paul 15crt puts the 
 figure as high as 7 per cent. The upper limit of the hepatic dulness neces- 
 sarily descends, the cardiac area of dulness is decreased, and the heart sounds 
 become muflied; The frequency of the respirations is much diminished ; they 
 often fall to twelve or thirteen per minute. Should the patient be suffering 
 from any pulmonary disease which renders the breathing difficult it often be- 
 comes easy, and the extremely rapid respirations of emphysema may fall to 
 normal. The amount of urea is increased, more oxygen is taken in, and more 
 carbon dioxide is given off. The pulse is small and slightly less rapid than 
 before the bath. The other changes are not of sufficient importance to be 
 mentioned here. 
 
 It is well known that bridge builders, divers, &c., who are in their occu- 
 pation subjected to great increases of atmospheric pressure, frequently suffer 
 from bleeding at the nose and lungs, and paralysis of the lower extremities 
 and bladder. These symptoms, however, are not due to the compressed air, 
 but to the suddenness with which the workmen come out of it into the ordi- 
 nary atmosphere. Therefore, it behoves us to increase and decrease the pres- 
 sure in a compressed-air bath gradually. The usual duration of the stay in 
 the bath is two hours : of this time the first half- hour should be occupied by 
 gradually raising the pressure to the desired point, then it should remain at 
 that point for an hour, and the last half-hour should be occupied by the de- 
 crease of the pressure. Many diseases have been treated by it, but only the 
 more important need be mentioned here. 
 
 Puhnonary Emphysema. — It is for this condition that the compressed-air 
 bath has given the most satisfactory results. After several baths, one taken 
 each day for several days, the breathing becomes easy, the dyspnoea diminishes, 
 the cough and expectoration are decreased, the respirations become slower 
 and deeper, the cardiac and hepatic dulness reappears, and the breath sounds 
 over the emphysematous lung become more audible, the vital capacity in- 
 creases, and the girth of the chest is lessened. The exact cause of the benefit 
 is not known. The usual course is to take a bath lasting two hours once a 
 day for thirty consecutive days. 
 
 Bronchitis.' — This disease is often benefited by a course of compressed-air 
 baths, but it is so difficult to separate bronchitis from its accompanying 
 emphysema that it is impossible to say how much of the benefit is due to 
 the treatment of the latter condition. 
 
 Phthisis. — The reason why compressed air is used in this disease is that 
 it is supposed to open out every healthy portion of the lung and to increase 
 the general nutrition. It is therefore chiefly indicated in those sickly pale 
 subjects afflicted with phthisis and who have ill-formed chests. It is said to 
 prevent the development of phthisis in those who present the above symp- 
 toms without having any actual signs in the lungs. The contraindications 
 to its use are high fever, great weakness, severe pulmonary haemorrhage, and 
 decomposing processes going on in the lungs. 
 
 Asthma.— li is stated that this malady is much improved by compressed- 
 air baths. Undoubtedly if the asthma consists only of those asthmatical at- 
 tacks which are so commonly met with in the subjects of emphysema, the 
 treatment will as it relieves the emphysema diminish the frequency of the 
 
BATHS G45 
 
 ■asthma-like attacks. It is, however, doubtful whether it has any effect on 
 genuine neurotic asthma. 
 
 The other diseases which may be treated by compressed air may be found 
 •described in the author's ' Text-book of General Therapeutics.' 
 
 Electric Baths 
 
 All that is necessary for an electrical bath is some arrangement for send- 
 ing the current, either faradic or galvanic, through the water of the bath. 
 A form used by Dr. Eussell and described by Beard and Eockwell in their 
 ■* Medical and Surgical Electricity ' is thus arranged. A long bath of ordi- 
 nary shape is taken. A broad copper plate as long as the water is deep is 
 .attached to the bath at either end of it. These plates are the poles of the 
 battery. At the head of the bath a board is placed a little distance from 
 the end ; it is sloped conveniently and has a slit in it, the shape of the 
 patient's back, so that he can lie against it comfortably. When now the cur- 
 rent passes some of it must pass through the body. Some electric baths are 
 so arranged as to allow the current to pass through a part only of the body. 
 
 It has not yet been proved that electrical baths are superior to the more 
 easily applicable methods of using electricity, but it is claimed that they are 
 particularly serviceable for rheumatoid arthritis and general exhaustion. 
 
 BATH AND BATHEOOM 
 
 All the houses built nowadays for the accommodation of the middle and 
 upper classes are provided with bathrooms. If the house is small one bath- 
 room is sufficient, but if it is large there should be one on every floor. 
 
 The bathroom should not open out of a bedroom unless it is to be used 
 solely by the occupants of that bedroom, for the noise of the inflow of water 
 is very disturbing to those who are asleep, and of course it is an extremely 
 bad plan for the only means of access to the bathroom to be through another 
 room. The writer remembers to have seen a bathroom in the country which 
 could only be reached by going through the drawing-rooms. It is preferable 
 to have the bathroom at the side of the house, not in the centre, so that 
 the waste water can be easily conveyed away to the outside. In small 
 houses the water-closet is often placed in the bathroom : this is not to be 
 commended, for the water-closet is useless to the rest of the household when 
 the bathroom is occupied, and further, if owing to imperfections in the water- 
 closet any foul air proceeds from it the bather will inhale this air during the 
 whole of the time he is in the bathroom. Nevertheless it is often con- 
 venient to have a water-closet close to the bathroom. The walls of the 
 TDathroom that are next to the bath should either be tiled, painted, or papered 
 -with glazed paper, so that it will not hurt them to be splashed. Frequently 
 the ceiling and wall near to the hot-water pipes is blackened by the current 
 of hot air coming from the neighbourhood of the warm pipes and depositing 
 dirt in their course. The best way to get over the difficulty is to paint the 
 ceiling instead of whitewashing it, for then it can be frequently washed. 
 What is sold as cork carpet forms a good covering for the floor, for it is 
 warm, smooth, and easily washed ; the only objection to it is that when 
 washed it takes some hours to dry, as the cork soaks up the water. Another 
 good plan is to cover the floor with linoleum and to have a square of cork 
 on which to step on leaving the bath. It is very important that a bathroom 
 should be well ventilated, for when a hot bath is being taken the air becomes 
 
GiQ HYGIENE 
 
 disagreeably warm and moist. It is unnecessary here to indicate the various- 
 means used for ventilating a room ; they are fully described in another article. 
 A tireplace in a bathroom is a desirable luxury, for a fire by which to dry 
 one's self is often desu-able for an invalid. 
 
 The materials commonly used for making a bath are iron, zinc, copper,, 
 porcelain, slate, and concrete. Iron, zinc, and copper are always enamelled 
 on the interior. Iron and zinc are the cheapest at first, but they require 
 very frequently to be re-enamelled at least every three or four years if the 
 bath is in constant use. This is expensive, and to do it the bath has to be 
 taken away for a few days. With an iron bath the enamel is particularly 
 liable to flake, because the metal is very inelastic, and is easily oxidised by 
 moisture. Zinc baths, in addition to the disadvantage of flaking, soon 
 change their shape, so that the bottom does not remain level, and con- 
 sequently all the water will not run out. Copper baths are very durable, do 
 not alter their shape, nor are they easily oxidised ; but they are expensive, . 
 and the enamel comes off as with any other metal bath. 
 
 Slate baths have the objections that as they are put together in slabs 
 they are liable to leak at the joints, and dirt collects in the corners. If they 
 are not enamelled it is difficult to see when they are clean, and if they are 
 enamelled the enamel soon flakes off". 
 
 Concrete baths have only recently come into use, so that at present we 
 cannot say whether they wear well. They are hea^-y and cumbersome. 
 
 Glazed fire-clay baths, or, as they are commonly called, porcelain baths, 
 are undoubtedly the best, for they have in the interior a smooth surface with 
 rounded corners, so that they are very easy to keep clean ; the glaze keeps on 
 an indefinite time, so that they always look nice, and they are extremely 
 durable. The chief objection to them is the primary cost, for they are 
 rather more than twice the price of an enamelled iron bath, but they are 
 cheaper in the long run, for owmg to the frequent enamellmg in a few years 
 the total cost of the iron bath exceeds that of the porcelain. The porcelain 
 baths, owing to their great weight, are difficult to fix in position, but 
 fixed no removal is ever necessary. A porcelain bath abstracts heat from 
 the water rather more rapidly than a metal one does, but the difference in 
 this respect is not sufficient to be of any practical importance. One of the 
 chief reasons why porcelain baths are dear is that several are spoiled before 
 one perfect one is made ; the result is that they can often be obtained at a 
 lower cost if one be bought with a slight blemish at the top, where it does 
 not really matter. When once they are fixed they are not particularly liable 
 to get broken. Owing to their durability they are very suitable for public 
 institutions. 
 
 Both hot and cold water should be supplied to the bath, and the supply 
 pipes should be sufficiently large to allow the bath to fill rapidly. They 
 should not run mider the bath, as then if they get out of order they are 
 difficult of access. In some baths the water, either hot or cold, or both, 
 flows in through the same pipe as that by which it leaves the bath : this 
 is a particularly objectionable arrangement, for the inflowing water washes 
 back into the bath all the dirty soap-suds that are lying in the waste-pipe. 
 A very common arrangement is for the hot and cold water to come into the 
 bath at the bottom by separate apertures, and for the taps which are just 
 outside the bottom of the bath to be worked by handles at the level of the top 
 of the bath ; the handles are connected to the taps by long vertical iron rods. 
 These taps are very liable to leak and to work badly, for the iron rod is 
 almost certain in time to bend a little one way or the other. The best 
 manner of introducing the hot and cold water is for the supply pipes to 
 
BATHS G47 
 
 come vertically up the outside of the end of the bath, for there to be screw- 
 down taps at the level of the top of the bath, and for the water to come in at 
 the top and fall down into the bath at the end. Most baths are slanting at 
 one end and vertical at the other ; the taps are best placed at the vertical end. 
 The hot water is usually supplied from a high-pressure kitchen boiler. All 
 apparatus by which the water is heated in the bathroom itself by gas should 
 be avoided, as the fumes of the gas are very objectionable and even dangerous. 
 The diameter of the outlet pipe for the waste water is usually too small. 
 It should be two inches for the bath to empty with proper rapidity. It is of 
 course no use to have an ample waste-pipe if the perforated holes through 
 which the water flows out or the water-way of the outlet tap are too small. 
 The outlet pipe should always open directly into the open air, and the water 
 should fall some distance before entering the pipe which is going to convey 
 it directly to the drain. This is most important in order to prevent the 
 back flow of sewer gas into the bathroom. It is not a bad plan to conduct 
 the bath water into the gutter of some adjoining roof. 
 
 There should always be under the bath a leaden tray about two inches 
 deep with a pipe from it into the external air. The object of this is to catch 
 and carry away any water which may come from any leak in the taps, pipes, 
 or bath. The overflow pipe from the bath should be at least two inches in 
 diameter, and should go directly into the external air. It cannot be too 
 strongly urged that no pipes proceeding from the bathroom must communi- 
 cate directly with the drains. Any draught that comes up the various pipes 
 leaving a bathroom may be prevented by providing the exit orifice with a 
 flapper. 
 
 The bath and its pipes are usually surrounded by a wooden casing with a 
 door so arranged that the pipes, corks, and leaden tray can be easily inspected. 
 This is, on the whole, the best arrangement, for it is very difficult to clean 
 away all the dirt which collects under the bath if it is exposed. Some metal 
 baths are, however, made to stand on claw feet, and they are painted on the 
 outside, so that a casing is not necessary. 
 
 BIBLIOGEAPHY 
 
 (1) Braun : Lehrbucli cler Balneotherapie. 5th edit. : edited by Fromm. Berlin. 
 
 (2) Leichtenstern : General Balneotherapeutics (vol. iv. Ziemssen's Handbook of 
 
 General Therapeutics. Eng. trans. London, 1885-6). 
 
 (3) Winternitz : Hydrotherapeutics (vol. v. Ziemssen's Handbook of General Thera- 
 
 peutics. English trans. London, 1885-6). 
 
 (4) Helfft: Handbuch der Balneotherapie. 9th edit.: edited by Thilenius Berlin 
 
 1882. 
 
 (5) Durand-Fardel : Traite des Eaux minerales. 3rd ed. Paris, 1883. 
 
 (6) Easpe: Heilquellen-Analysen fiir normale Verhaltnisse, und zur Mineralwasser- 
 
 fabrikation berechnet auf zehntausend Thale. Dresden, 1885. 
 
 (7) Macpherson : Our Baths and Wells. 3rd ed. London, 1888. 
 
 (8) De la Harpe : La Suisse balneaire et climat^rique. Zurich, 1891. 
 
 (9) Hale White : A Text-book of General Therapeutics. London, 1889. 
 
THE DWELLING 
 
 BY 
 
 P. GOEDON SMITH, F.E.LB.A, 
 
 AND 
 
 KEITH D. YOUXG, F.E.LB.A. 
 
THE DWELLING 
 
 Of all conditions that are prejudicial to the healthfulness of the dwellings 
 air that has been rendered impure is the most productive of evil. The late 
 Dr. Edmund A. Parkes has truly said that a healthy dwelhng must comprise 
 the following five conditions : — 
 
 1. A site dry and not malarious, and an aspect which gives light and 
 cheerfulness. 
 
 2. A ventilation which carries off all respiratory impurities. 
 
 3. A system of immediate and perfect sewage removal which shall render- 
 it impossible that the air shall be contaminated from excreta. 
 
 4. A pure supply and proper removal of water by means of which perfect 
 cleanliness of all parts of the house can be insured. 
 
 5. A construction of house which shall insure perfect dryness of the 
 foundations, walls, and roof. 
 
 It will be observed that in these conditions pm'ity of air, and in that 
 purity must be included cleanliness, is the fundamental principle aimed at. 
 Notwithstanding the apparent simplicity of these principles, and the obvious- 
 ness of the necessity for each and all of them, it is, unfortunately, rare to- 
 find, even in the present day, a dwelling in which due attention has been paid 
 to them. In the past, neglect of these principles has led to plague and 
 pestilence to an extent which it is difficult for us to appreciate, and, were 
 similar neglect to exist now, when the population is so far more numerous- 
 and dense than formerly, who can conjecture to what magnitude the 
 disastrous results of such neglect might attain ? We are reminded every 
 now and again by comparatively small local outbreaks of disease, of the neces- 
 sity for paying due attention to this question of purity of air and cleanhness ; 
 but how can we estimate what would be the results were such a plague as 
 that which visited London in 1665 permitted to get firm hold of the London 
 of the present day, with its five millions of inhabitants and its means of 
 almost hourly communication with all the large towns of the provinces ? 
 
 It is well to bear in mind what were the ravages of that plague, and the 
 rate at which it progressed. Thomas De-Laune in his ' Memorials of London,' 
 1681, after giving accounts of many other pre\T.ous plagues and epidemics, 
 says : — 
 
 In the beginning of May (1665) the Bill of Mortality mentions nine that died of the 
 plague, and decreased the next week to three, then increased to fourteen, next to seventeen, 
 next forty-three, and then great persons began to retire into the country. In Jane the 
 bill increases to 112, next 168, next 267, next 470 ; then do many tradesmen go into the 
 country, and many ministers take occasion to absent themselves from their charge. In 
 July the bill rises to 725, then to 1,089, next 1,843, next to 2,010. Now most parishes are 
 infected, a vast number of houses are shut up, no trade at all, and the number of dying 
 persons still increasing, although so many thousands left the city. In August the bill 
 rises to 2,817, next 3,880, next 4,237, and then 6,102, all which died of the plague besides 
 other diseases. Now there is dismal sohtude in London streets, every day looks with the 
 face of a Sabbath, observed -with greater solemnity than it used to be in the city. Shops 
 are shut up, very few walk about, so that grass begins to spring in some places. A deep 
 silence everywhere, no ratling of coaches, &c., no calling in customers, no London crys, no 
 noise but dying groans and funeral, knells, &g. In September the bill rises to 6,988, the 
 
Go2 HYGIENE 
 
 next falls to 6,544, but then rises again to 7,165, which was the greatest bill. There were 
 but four parishes that were not infected, and in them few tarried. The next bill falls to 
 5,538, then to 4,929, then to 4,327, then to 2,665, then to 1,421, then to 1,031. First week 
 in November it rises to 1,414, but falls to 1,050, then to 652, then to 333, and so lessened 
 more and more to the end of the year, when we had a bill of 97,306 which died of all 
 diseases, which was 79,000 more than the year before, and the number of them which died 
 of the plague was reckoned to be 68,596 that year ; but others say that there died of that 
 fatal disease, in little more than a year's space, near 100,000 persons in London and 
 some adjacent places. 
 
 Such was the penalty paid by the community for allowing the houses to 
 be crowded together, wdth narrow and crooked alleys and passages which 
 served as streets, to which sunshine never had access, and which did not 
 permit of proper circulation of air ; for failing to provide any efficient means 
 for the removal of the filth and sewage, which remained on the street surface 
 until washed away by rain ; and, in fact, for allowing a dense city to grow up 
 without any efficient control in its growth or management. 
 
 The fearful ravages above recorded, however, give us only the death-roll 
 consequent on that terrible epidemic. This outbreak of plague was only the 
 culmination of a long series of shockingly unhealthy conditions which had 
 previously caused repeated outbursts or ' explosions,' but which at length 
 developed to the enormous extent set forth by De-Laune. These preceding 
 conditions must have affected the general health of the population to a degree 
 which it is impossible to estimate, and of which there is no sort of record, 
 direct or indirect. 
 
 The circumstances mider which outbreaks of disease occur nowadays, 
 terrible as they appear to us, are very different ; even the occurrence of many 
 cases of typhus in some densely crowded quarter of a town is a small matter 
 compared with the plagues of old, which ran their course until they had 
 literally exhausted the supply of subjects to attack; and the magnitude of 
 the old epidemics is now rarely approached, notwithstanding the vastly 
 increased facilities that exist for the spread of disease, owing to growth and 
 intercommunication of the population. 
 
 The lessons that have been taught by the great epidemics in the past in- 
 dicate three important factors in regard to the healthy conditions of towns : 
 1. That there must be wide streets with frequent cross streets, and also 
 ample open space about the houses, so as to promote the free circulation of 
 air. 2. That the internal arrangements of the individual houses shall be 
 such as 's\ill conduce to their efficient ventilation and to the purity of the 
 air inside them. 3. That the administration of the town shall be such as 
 to ensure the unstinted supply of pure and wholesome water, the effectual 
 removal of all sewage and liquid refuse, and the regular and thorough 
 scavenging and removal of refuse. These three conditions are requisite 
 wherever a few dwellings are clustered together. 
 
 That they have been generally seriously neglected is evident in all parts 
 of the kingdom, and the results are demonstrated by the unhealthy condi- 
 tions that so frequently form the subject of official investigation either 
 by the local health officers or by the inspectors of the medical department 
 of the Local Government Board. As regards the first, the results of past 
 neglect of control in the laying out of towns is demonstrated by the vast 
 expenditure of money that in recent years many local authorities have 
 found themselves compelled to incur for the acquisition, under statutory 
 powers, of extensive areas of insanitary properties in order that the build- 
 ings may be demolished, and that new streets of greater width may be laid 
 out, and new houses having adequate air space about them may be erected. 
 In this way millions of pounds sterling have in the last thirty or forty years 
 
THE DWELLING 653 
 
 been spent in the metropolis and in some of the principal towns of the pro- 
 vinces. In many districts of London where houses were huddled together in 
 the closest possible fashion, and contained populations of great density, areas 
 have been cleared and comparatively broad streets with improved buildings 
 have been erected on them. In the same way in Liverpool, in Birmingham, 
 in Newcastle-on-Tyne, in Leeds, and elsewhere, similar improvements have 
 been made ; and although in some respects, as will be described later on, 
 these changes leave much to be desired, they nevertheless have exercised a 
 very marked improvement on the health conditions of the localities. 
 
 The way in which some of these insanitary areas were allowed to grow 
 up is not without its special interest, and the study of the growth of such 
 areas ought to teach a lesson worthy of application in numbers of towns now 
 growing rapidly in size and population, and which, indeed, may perhaps not 
 grow to be quite so bad as some of the places already referred to, but which 
 are most certainly allowing a very unwholesome aggregation of houses and 
 population to occur, and cannot fail to involve serious difficulty and ex- 
 pense in the future. This growth of unhealthy areas may be seen in most 
 of our larger towns and in many of the smaller ones and even in many 
 villages, while at numbers of seaside ' health resorts ' the process of crowd- 
 ing houses on area has been going on until within quite recent years, and in 
 others it is still going on. 
 
 Thus one may see in streets of very modest width rows of what were 
 once convenient houses originally built for single families, and had a good 
 depth of garden at their rear. These, owing to the altered character of the 
 neighbourhood or local changes in trade or manufacture, have come to be 
 occupied by many families in each house ; narrow passages or courts have 
 been formed at intervals through the gromid storey in order to give access 
 to blocks of smaller houses that have been built on the garden ground at 
 the rear, and in between these have been wedged the scanty privy and ash- 
 pit accommodation for the dense population now occupying the area. In 
 the older parts of many watering places, which during the summer months 
 are crowded with visitors, so that the population is trebled or quadrupled, it 
 will be found that the yard originally left at the rear of many of the houses 
 is almost wholly obstructed by a smaU house which has been built in it, to 
 which the proprietor retires during the letting season in order that the main 
 house may be freed for the occupation of the visitors ; and thus the smaller 
 backhouse has no means of through -ventilation whatever, and only a small 
 and confined well of stagnant air in front of it, which also has to serve as the 
 open space at the rear of the front main house. 
 
 The reports of the Medical Officer of the Privy Council and Local 
 Government Board refer to many instances tending to show that crowding 
 of houses on area and corresponding density of population are attended with 
 endemic and epidemic disease. Thus in the report ^ by Dr. George 
 Buchanan on epidemic typhus at Greenock, in 1865, it is shown that 
 Greenock had an excessively high general death-rate, due to a large extent 
 to the deaths of children, as YfeM as to special fatality of lung diseases and 
 consumption, and likewise to the then recent epidemic prevalence of 
 measles, scarlatma, smallpox and diphtheria, each of which diseases had 
 affected the town with exceptional intensity. The cause of the great 
 epidemic prevalence of fever was attributed entirely to overcrowaing and the 
 dirty habits of the people, little or no influence being ascribed to defects of 
 drainage, and any exceptional destitution being at that time wholly wanting 
 
 ' See Eighth Ammal Report of the Medical Officer of the Privy Council, Appendix, 
 p. 209. 
 
654 HYGIENE 
 
 as a causative element. The crowding of tenement houses on area is 
 described in that report as prevailing to a remarkable extent in the old part 
 of Greenock, every particle of ground that was not street being covered with 
 buildings. It is said that some air trickles between the tops of the tenements 
 and may get into the upper tenements, but in not a few of the lower ones 
 the back rooms receive no breath of air or ray of light. The description 
 given of the crowding of persons within the houses is even more striking. 
 
 It is remarkable how this crowding of population on area has grown up 
 in the course of centuries ; comparatively speaking, very few new towns 
 have sprung up, and nearly every town and village throughout the land owes 
 its origin to, and indeed has some sort of evidence in proof of its existence in 
 the time of the Eomans, the Saxons, or the Normans ; thus, even in those 
 days, the country was studded with villages lying between the greater towns, 
 and many of these have since grown to be chief provincial towns or cities, the 
 growth of which has been partly circumferential, but m a large degree caused 
 by the closer packing together in the centres. This is shown in a very clear 
 manner in one of the annual reports of the Medical Officer of the Local 
 Government Board. ^ In anticipation of the country being visited by cholera, 
 the Board caused a sanitary survey to be made of the coast towns where 
 cholera might be imported from infected countries and of a large number of 
 other towns where it was known that other diseases spreading under some- 
 what similar circumstances to cholera — e.g. enteric fever or epidemic 
 diarrhoea — habitually prevail. In this survey special attention was directed 
 to the general condition of the dwellings of the poor and labouring classes, 
 and specially to the prevalence of crowding of dwellings on area as well as 
 of overcrowding within dwelhngs. The tabulated precis of the reports upon 
 the various places surveyed showed some striking instances of crowding of 
 houses on area about narrow courts and streets ; and this notably in the 
 cathedral and university towns. 
 
 The provision of ample open space in our towns in the form of wide 
 streets, cross streets at frequent intervals, public squares, boulevards, and 
 parks and gardens within easy reach of the inhabitants, especially the 
 children, where they can assemble in the open air for exercise and recreative 
 purposes, has in the past failed to receive as much attention in the laying 
 out of districts as it deserves. In some of the large proprietary estates of 
 London — e.g. the Grosvenor, the Penton, the Bedford, the Portland, and the 
 Portman Estates — some splendid squares and streets have been formed, 
 which have been of enormous benefit to the inhabitants, and in a scarcely less 
 degree to the public ; but wherever the land has been in the hands of small 
 owners it has been subject to all the disadvantages of the numerous indivi- 
 dual interests ; and, in the total absence of any legislative requirements, 
 improvement of this kind has been impracticable. 
 
 Such open areas as have just been referred to are as indispensable in their 
 way in our towns and cities as are the open spaces now commonly required 
 about individual houses, and yet no laws have hitherto been framed for making 
 the provision of them compulsory. Some slight efforts have been made in recent 
 years to increase the voluntary provision of open space in thickly populated 
 areas ; thus, for the metropolis, the MetropoHtan Open Spaces Acts of 1877 
 and 1881 have given facihties for the acquisition, maintenance, and regulation 
 of open spaces and burial grounds by the local authorities of the metropolis 
 for the use of the public for exercise and recreation, and authorise, for the 
 
 ' Fifteenth Annual Report of the Local Government Board, 1885-86. Supplement 
 containing [c. 4873] ' Eeports and Papers on Cholera submitted by the Medical Officer of 
 the Board.' 
 
THE DWELLING 
 
 655 
 
 purposes of those Acts, the expenditure of such funds as those authorities 
 have at their disposal. Similar facilities for making open spaces and burial 
 grounds situated in the provinces available for the like use by the public 
 are also afforded by the Open Spaces Act, 1887,' which latter Act has 
 amended the previous Acts in several particulars, and has rendered most 
 of the amended provisions of those Acts applicable, with the necessary 
 modifications, to every urban and rural sanitary district in England and > 
 Wales. Under these Acts powers are given to local authorities to acquire, 
 either by purchase or gift, and to trustees and other persons and corpora- 
 tions under disability or possessing limited interest, to transfer open spaces 
 and disused burial grounds to the sanitary authorities in order that they may 
 be held in trust and maintained, and if necessary be laid out and improved 
 with a view to their enjoyment by the public in an open condition, free from 
 buildings and under proper control and regulation. 
 
 These Acts should be constantly borne in mind by local sanitary authori- 
 ties and their officers, especially in districts where the population is rapidly 
 increasing and the ground is being speedily covered with buildings, in order 
 that a due amount of open space, over and above what is afforded by streets 
 of ordinary width, may be secured to the public at a time when it can be 
 acquired without much difficulty and before the erection of houses over the 
 whole district renders the acquisition of such open space practically im- 
 possible. The provision of open space for the use of the public ought of 
 course to be made with due regard to its equable distribution over the popu- 
 lation, since the greatest benefit would result from its proximity to the 
 several parts of the districts. Hence, a broad boulevard all round a town or 
 directly through it would be one of the most useful forms of open space ; or, 
 again, a number of open squares situated in different parts of a town would 
 be of more general use than a single park of even large extent situated at 
 one end of the same town. If, when a town aspires to be incorporated as a 
 borough, it were required, as a condition of its promotion, to acquire and set 
 apart for the use of the public a certain extent of land as open space for 
 exercise and recreative purposes, what vast benefits would result to the 
 inhabitants ! It may be difficult to lay down any proportion of area to 
 population as a minimum, but a comparison with what exists in certain 
 towns and cities would serve as some sort of guide to assist in considering 
 what might be fairly demanded.^ Much is undoubtedly being done in the 
 
 » 50 & 51 Vict. cap. 32. 
 
 2 The number of persons per acre of open space is given by E. E. L. Gould in the 
 publications of the American Statistical Association as follows : — 
 
 A B 
 
 In London . . .694 909 
 
 Paris . . .495 985 
 
 Berlin . . .804 1,814 
 
 Edinburgh. . . 246 672 
 
 Vienna . . .473 3,805 
 
 Manchester . .2,230 — 
 
 New York . . .994 8,334 
 
 The figures in column A hardly give an accurate notion of the proportion of open space 
 
 which the inhabitants of the several cities and towns really enjoy, partly because of the great 
 
 differences in the width of streets, and partly because of the differences in the way in 
 
 which the open space is distributed. Accordingly, column B is introduced in which thearea 
 
 of the largest distinct park in each city or town has been omitted, and the result shows in 
 
 some instances a vastly increased number of persons to the acre. But as regards absolute 
 
 proportion of open space to population, Washington appears to be far ahead of any large 
 
 city in the world, and it has also the greatest relative number of small open spaces — Tlw 
 
 Sanitary Engmeer, New York, Jan. 5, 1889. 
 
 
 A 
 
 B 
 
 Boston . 
 
 . 301 
 
 529 
 
 Baltimore 
 
 . 376 
 
 1,749 
 
 Philadelphia 
 
 . 340 
 
 17,649 
 
 Cincinnati 
 
 . 678 
 
 1,528 
 
 St. Louis 
 
 . 164 
 
 460 
 
 Washington 
 
 . 361 
 
 451 
 
656 HYGIENE 
 
 way of providing open spaces. The acquisition of various areas in the 
 suburbs of London is a most valuable pro\'ision for the public good, the 
 magnificent roads that are being formed in some districts — e.g. that in the 
 Toxteth Park district at Liverpool leading out to Princes Park — all show 
 that the necessity for open spaces is recognised, but much still remains 
 to be done, and the public have to be led to understand the necessity for it. 
 
 The question of density of population is one that cannot properly be over- 
 looked in connection with the hygiene of the dwelling. It has been affirmed 
 that the density of population affords no index of the death-rate, but, not- 
 withstanding, it is shown in the annual reports of the Kegistrar-General that 
 the highest death-rates occur in the most densely populated areas, and that 
 infant mortality in general, and diarrho3a in particular, prevail wherever there 
 is great aggregation of population. Doubtless this is to some extent to be 
 accounted for, partly by the social habits of the people themselves and partly 
 by defective local administration, such as improper scavenging and insuf- 
 ficient water supply, but perfection of these matters will not alone suffice to 
 place the sanitary state of a densely populated area in the same condition as 
 an equally well-cared-for area, where the population is sparsely distributed. 
 Where there is considerable density of population, it follows that the houses 
 must be packed very closely together, that the rooms must be occupied 
 by numbers of persons approaching what is known as ' overcrowding,' and 
 that the houses may even be of excessive height in proportion to the open 
 space about them. According to the minimum open space about houses re- 
 quired by the Model Bye-laws of the Local Government Board, the largest 
 number of water-closeted cottage dwellings that can be got on an acre of 
 land is forty-eight when each house has a frontage of 14 ft. 9 in. and con- 
 tains a living room and scullery m the ground storey, two bedrooms in the 
 upper storey, and an attic room, and if privies are substituted for water-closets, 
 and the requisite back streets are provided for the removal of ashes and 
 privy refuse, the number of similar houses would be only forty-one or forty- 
 five, according to the width of the back street.^ Supposing that each of these 
 houses is occupied by an average of five persons, the density of population 
 would be represented by a rate of 240 persons to the acre in the former 
 instance, and from 205 to 225 to the acre in the latter instance. 
 
 In some of the blocks of artisans' dwellings that have been erected in the 
 metropolis this rate is very largely exceeded. Thus, from the evidence given 
 in 1884 before the Koyal Commission on the Housing of the Working Classes 
 the density of population is stated to be, in some instances, at the rate of about 
 1,000 persons to the acre,'^ and the health of the inhabitants, judged by the 
 mortahty statistics, is stated to be satisfactory. In these instances the 
 buildings were designed to be six storeys in height, and, notwithstanding 
 certain objections raised by the Home Office to their great height, those 
 objections were ultimately waived, and a height of six storeys eventually 
 became the rule,-^ and even this has since been exceeded. In some instances, 
 however, these buildings were so crowded on the area that, owing to their 
 height, to the limited amount of open space in the internal court or ' play- 
 ground ' and about the exterior, to the absence of openings at the angles of 
 the court, and of sufficient openings from the court into the adjacent streets, 
 there were serious impediments to the access of sunsliine and to free circula- 
 tion of air about them, with the result that the health conditions of those 
 particular buildings, though the fittings and details of construction were 
 
 ' Report on Back-to-back Houses. By Dr. Barry and Mr. P. Gordon Smith. London : 
 Eyre & Spottiswoode, 1888. 
 
 - Q. 11812 and 1181:3. ^ q. 11348. 
 
THE DWELLING 667 
 
 identical with those of other more healthy buildings, were reported to be far 
 worse than others, the rate of infant mortality specially being much higher 
 in them than elsewhere. 
 
 In the recent report to the Local Government Board by Dr. Ballard upon 
 the causation of the annual mortality from diarrhoea ' he points out, among 
 the more important conditions influencing diarrhoeal mortality, that aggrega- 
 tion of population favours, and dispersion over area disfavours, diarrhoea ; 
 that density of buildings (whether dwelling-houses or other) upon area pro- 
 motes diarrhoeal mortality ; and that restriction of and impediments to the 
 free circulation of air, both about and within dwellings, promote diarrhoeal 
 mortality. There are, it must be admitted, many strong reasons for allowing, 
 in some cases, considerable aggregation of population on area, and within 
 certain limits and under certain conditions as regards local administration, 
 it may be permissible, in such cases, to approach, though scarcely to reach, 
 the very high rate of density above referred to. But it appears certain that 
 high rates of density cannot be allowed with impunity, and that some limit 
 must be determined upon. Overcrowding, in the form of an abatable nui- 
 sance, has a statutory limitation to an individual house or part of a house, 
 and the only way by which such vast numbers can be aggregated on area 
 is by piling up houses one upon another in the form of tenements, and so 
 long as the height to which buildings may be carried remains unlimited 
 by law, this method of providing house accommodation will go on extend- 
 ing. A single building of abnormal height here and there may, in itself, 
 be of little harm ; but when repeated in near proximity one to another 
 the conditions would become serious. At least, some means ought to be 
 found for securing adequate open space about every such high building. 
 This would not only suffice for securing freer circulation of air about the 
 dwellings, but it would at the same time have the effect, indirectly, of placing 
 some moderate restrictions on the number of persons to be provided for on 
 any given area. In the recommendation of the Housing of the Working Classes 
 Committee of the London County Council, which was adopted by the Council 
 at the end of 1889, it is suggested that the distance between any block of 
 dwellings and the nearest building obstructing the light from its windows 
 should, if practicable, be equal to one and a half times the height of the 
 obstructing building. But it is anticipated that, in view of the cost of land 
 in the metropolis, such distance cannot be generally provided. It is, how- 
 ever, laid down that ' under no circumstances should a nearer distance than 
 the height of the buildings be allowed.' It remains to be seen how far even 
 this modification of what is considered most desirable can be complied with. 
 That it is an excellent rule in the interest of health can scarcely be ques- 
 tioned, but the difficulties of strictly adhering to it where questions of finance 
 occur appear to be almost if not quite insuperable. 
 
 In reviewing the dwelling accommodation of the population of such a 
 country as the United Kingdom, it will be found that it may be classified 
 somewhat as follows :— 1. There are the mansions and large houses of the 
 nobility and wealthy, studded all over the country and in the best parts of 
 the metropolis. 2. Then there are. the smaller houses and villa residences 
 of the so-called middle classes, occupying perhaps equally good positions but 
 much smaller areas of site. 3. Next to these, and scarcely differing in ac- 
 commodation, are the terrace houses of the same class, clustered more closely 
 together, as most of the occupiers of them have to be within a certain limited 
 distance from some neighbouring locality or place of business. 4. Closely 
 
 ' London : Eyre & Spottiswoode, 1889. [c. — 5638.] 
 VOL. I. U U 
 
G58 HYGIENE 
 
 allied to these is the class of dwelling combined with place of business. 5. 
 The next kind of dwelling is the small house or cottage of the artisan and 
 wage-earning community — perhaps the most numerous of all — which varies, 
 as in the other kinds of dwelling, according to locality and circumstances. 
 6. Lastly there is the institution in which is housed a greater or less number of 
 persons who are gathered within its walls for some common purpose or object. 
 
 Each of these several kinds of dwellings is necessarily subject to numerous 
 modifications, many of which must be considered distinctly under their various 
 heads. Thus in the case of the first class — mansions — must be included the 
 palaces of Royalty and of the nobility, the magnificent mansions and extensive 
 dwellings, with their dependencies, both in town and country, of the merchant 
 princes and wealthy manufacturers. The second class embraces not only the 
 suburban and country house of the ordinary professional man of business and 
 wealthy tradesman, whether retired or still in business, but the country par- 
 sonage and the residence of the well-to-do farmer together with the out- 
 buildings connected therewith. The third class is more essentially urban, 
 and is chiefly concerned with that vast section of the so-called middle class 
 of the commmiity, whether professional, clerical, or commercial, who are 
 compelled to live in, or in the immediate neighbourhood of, towns, where land 
 is too valuable to admit of the houses having more than is requisite for them 
 to stand on, with a small amount of open space in front and at their rear. It 
 must likewise include what have come to be known as ' flats.' The fourth 
 class embraces the dwelling in connection with the place of business such 
 as the ordinary shop premises with dwelling apartments above, also the 
 hotel, inn, and such like. The fifth class is by far the most numerous, 
 and the modifications of it are very varied. Thus, it must include the 
 agricultural labourer's cottage in the country and the artisan's cottage in 
 the manufacturing town, the tenement house in the block of artisans' dwel- 
 lings, the common lodging-house, and the accommodation let out to lodgers 
 generally, including what are known as ' cellar dwellings.' The sixth class — 
 institutions — must include residential schools, barracks, asylums, work- 
 houses, prisons, hospitals, &c. 
 
 The extraordinary increase of population that has taken place in recent 
 times throughout the country, and most of all in the urban parts, has neces- 
 sitated the erection of vast numbers of new houses. There is apparently 
 much difference in the numbers erected year by year in the various localities, 
 caused no doubt by the variations in trade and prosperity as well as by a 
 variety of local circumstances, but the numbers generally are very considerable. 
 According to the census returns for England and Wales, there was a large 
 increase in the number of inhabited houses during the ten years ending April 
 1891, the total number of such houses in April 1881 having been 4,831,519, 
 and in April 1891, 5,460,976, or an increase of 13 per cent. There were also 
 at the date of the census 1891, 380,117 unoccupied houses and 38,407 in 
 course of erection ; but these numbers were somewhat lower than at the date 
 of the previous census. In the Metropolitan Police District, inclusive of the 
 city, with its population (1891) of 5,633,332, there are 797,679 inhabited 
 houses, and these have increased during each of the decennial periods ending 
 1871, 1881, and 1891 by 93,504, 117,661, and 151,984 respectively. These 
 large figures will be more readily appreciated when it is realised that they 
 mean that during the first of those three periods an average of thirty-one 
 new houses were finished in the Metropolitan Police District on every working 
 day ; during the second period thirty-eight new houses were so completed ; 
 and during the third period as many as forty-nine new houses were completed, 
 on the average, on every working day of the ten years. 
 
THE DWELLING 659 
 
 It will be seen that, according to the census 1891, the average number ol' 
 persons in every inhabited house was 7"6, but by far the larger proportion of 
 these new houses are houses intended for artisans and the wage-earning 
 classes, which let at weekly rents ranging between five and eight or ten 
 shillings a week, or at yearly rentals of about 20Z. to 30L or 35L, and in 
 which the average number of inhabitants is probably between four and five 
 per house. 
 
 Whatever the class, there are certain indispensable conditions of con- 
 struction that are common to every dwelling, be it a palace, a labourer's 
 cottage, or an institution in town or country alike, if it is to be such as may 
 be regarded as healthy. Thus it must be so constructed as to be able to be 
 kept free from damp, to be proof against weather and excesses of temperature 
 -or sudden external changes, and to maintain the air within it in a proper 
 a,nd wholesome condition. These indispensable conditions have for the most 
 part been dealt with in more or less detail in the Model Bye-laws as to new 
 buildings ^ which were issued by the Local Government Board in 1877 for the 
 ^■uidance of sanitary authorities when framing building regulations for their 
 districts, and comprise the following provisions: — {a) the site of the dwelling 
 must be free from offensive soil, and the surface of the ground enclosed within 
 the walls of the building must be covered with a layer of good cement concrete 
 in order to exclude any sort of ground air from the building ; (&) the external 
 walls must be of suitable material and of adequate thickness and construction 
 such as will effectually keep out the weather and afford reasonable means of 
 preserving to the interior of the dwelling a suitable temperature ; (c) the 
 whole of the walls of the dwelhng, whether external walls, party walls, in- 
 ternal cross walls, or sleeper walls supporting the flooring of the lowest storey, 
 must have an adequate and efficient damp-proof course to prevent moisture 
 rising in them by capillary attraction ; {cl) the roof must be thoroughly 
 weather-tight, and ought to be of such construction as will effectually serve to 
 protect the interior of the dwelling not only from rain, hail, and snow, but 
 from external heat and cold ; (e) the means of light and ventilation throughout 
 the dwelling must be adequate and effectual ; (/) the means of removing 
 waste water, sewage, and refuse of every description must be cleanly, regular, 
 and speedy, and such as will not in any way be prejudicial to the health con- 
 ditions of the dwelling ; {g) the means of supplying, storing, and distributing 
 water must be such as will secure an unstinted supply, and will not allow 
 its quality to be impaired. 
 
 It may be useful here to refer briefly to the details of these several indis- 
 pensable conditions in order that the necessity for them as well as their full 
 advantage may be duly appreciated and understood. 
 
 The first of them [a) relates to the protection of the interior of the dwel- 
 ling from exhalations from the ground upon which it is built. 
 
 If a site has been artificially made, the greatest care is necessary to ascer- 
 tain that the subsoil is free from any organic matter in a state of decompo- 
 sition. Sites are dealt with by the enterprising speculating builder in a 
 remarkable manner. In some districts much profit is made out of the site 
 before any building is put upon it : thus, the turf is first sold, then the sur- 
 face ground is disposed of for garden purposes ; the subsoil is then excavated, 
 sometimes for sand or gravel, which always has a good market value, some- 
 times for stone, and sometimes for clay with which bricks are manufactured 
 or which is burnt for ballast. The site is then used as a tip for rubbish ol 
 all kinds, a small fee being charged for each load that is deposited upon it ; 
 
 » The Model Bye-laics of the Local Government Board. London : Knight & Co. 
 
 D u2 
 
6C0 HYGIENE 
 
 and when its level is raised to a suitable height, it is regarded as ready for use 
 as a building estate. It will, therefore, be obvious that in the majority of 
 such instances the materials deposited on the site are such as would be 
 likely to become a source of danger to the healthiness of any dwelling that 
 might be erected thereon. Hence in all well-regulated districts it is required 
 under the local building bye-laws that all materials impregnated with either 
 faecal matter or with animal or vegetable matter should be removed by exca- 
 vation or otherwise from any such site before any new dwelling is erected 
 upon it. This may invols'e much cost and labour in excavation, but if a 
 sufficient len-gth of time has elapsed since the objectionable material was 
 deposited on the site, the objection may possibly have been removed by the 
 ordinary process of decay. On this particular question some very interesting 
 experiments, having for their object to ascertain what the effect of time had 
 been on the organic matters which, together with cinder refuse, had been 
 used to fill up inequalities in the ground, were made by Professor Burdon 
 Sanderson, M.D.,F.R.S., and the late Professor Parkes, M.D.,F.R,S., during an 
 investigation some few years ago into the sanitary condition of Liverpool, 
 and in their report it is stated that ' the process of decay of all the most 
 easily 'destructible matters,' including vegetable refuse, 'is completed in 
 three years,' while in the case of wood and woollen cloth the process was 
 more prolonged. It is further stated that ' the vegetable and animal matter 
 contained in the cinder refuse decays and disappears in about three years, and 
 is virtually innocuous before that time.' In view of these statements it may, 
 therefore, be assumed that for practical purposes three years will amply suffice 
 for the removal by oxidation of the objectionable matters in such refuse. If, 
 however, faecal matter has at any time formed part of the refuse, more strin- 
 gent precautions ought obviously to be taken ; indeed, under such circum- 
 stances, unless all soil so contaminated were completely removed, a much 
 longer period should be permitted to elapse before building operations could 
 safely be allowed to commence. 
 
 As regards the necessity for covering the site of a dwelling with concrete, 
 the sanitary advantages of this precaution are far more considerable than is 
 commonly supposed, while the extra cost involved by it may be less appre- 
 ciable than at first sight appears to be the case. Dr. Geo. Buchanan, F.E.S., 
 in his report on the distribution of phthisis as affected by dampness of soil,' 
 has shown that wetness of soil is a cause of phthisis to the population living 
 upon it, and it has long been kno>vn that residence on a damp subsoil as the 
 foundation for a house favours the prevalence of pulmonary disease ; hence 
 the precaution under consideration is most desirable, if only on the score of 
 dampness. But there are other reasons which render it most essential. 
 Ground air itself, even if not laden with watery vapour, may contain material 
 chat it is most important to keep out of the dwelling, such as carbon dioxide 
 or it may be poisoned by the soakage from a neighbouring leaky drain or 
 sewer, or from an ashpit or a cesspool. Even if the street in fi-ont is not 
 flagged and paved, and the yard behind is not flagged or asphalted as it 
 ought to be, the ground surface outside the house is quite impervious 
 during a hard frost, and the chimneys and fires in the dwelling exercise to 
 a certain extent a process of suction on the ground immediately beneath the 
 dwelling, and a quantity of ground air with all its impurities may easily 
 be drawn into it. Nor is this by any means a mere theory, since instances 
 are on record of ordinary coal gas having been thus drawn a considerable 
 distance beneath the frozen surface of the ground, from a leak in the gas 
 main under a road to the interior of a neighbouring dwelling-house. It 
 ' Tenth Report of the ITedical Officer of the Privy Council, 18G7. 
 
TEE DWELLING G61 
 
 is, therefore, most desirable that the surface of the ground under every 
 ■dweUing should be covered with a layer of good cement concrete, 4 to 
 6 inches thick, and floated over to a smooth top surface with fine sand and 
 cement so as to form a close and impermeable floor. This concrete may 
 serve in many instances as the floor itself, and thus save the cost of any 
 other flooring. Such concrete floor would generally suffice in passages, 
 halls, staircases, sculleries, washhouses, pantries, and perhaps in kitchens 
 and other offices. Moreover, where a boarded floor is used, a space of at 
 least 9 inches has to be left for ventilation and as a precaution against 
 dry rot in the floor timbers, between the underside of the floor-joists and the 
 ground-surface, whereas if the latter be covered with such a layer of concrete 
 as is above described, the distance between its surface and the underside of 
 the floor-joists may, without impropriety, be reduced to, say, 3 inches, 
 thus effecting a saving of two courses of bricks (6 inches) in the height of 
 all the walls of the building — an item which would go some way towards 
 meeting the cost of the concrete. 
 
 The second {b) of the indispensable conditions above referred to con- 
 cerns the external walls of the dwelling, and the character and construc- 
 tion of these will depend to a certain extent upon the aspect and situation 
 of the building. Ordinarily a brick wall only 9 inches thick is not suf- 
 ficient to keep out the weather, especially if in anything like an exposed 
 position. The bricks are of a porous nature, and driving rain will be 
 forced through them, and show itself in the shape of moisture and damp- 
 ness on the inside. A common stock brick will absorb as much as one 
 pound of water, and therefore it will be readily understood that rain 
 may easily be driven through a wall where the bricks known as ' headers ' 
 extend through the entire thickness of the wall. Indeed, air is constantly 
 pressed through such bricks, and though this may be said to assist ventila- 
 tion, it at the same time tends to lower the temperature of the interior of 
 the house. The facility with which air may be pressed through certain 
 kinds of bricks is shown by the common experiment of coating the four sides 
 of a porous brick with wax and fixing a glass funnel on to each end of the 
 brick, when sufficient air may be blown from the mouth applied to the tube of 
 one of the funnels so as to obviously influence the flame of a candle held near 
 the tube of the other funnel. It is desirable in all dwellings that the external 
 walls should, if of brickwork, be at least a brick and a half — i.e. 14 inches — 
 thick, so that there may be a vertical layer of mortar, in addition to the 
 bricks, in the structure of the wall itself. In the case of stone walls and 
 walls in which there is an exceptional quantity of mortar, as in rubble work, 
 'flint work, and such like, it is desirable to increase the thickness. In ex- 
 posed situations it is common to construct the external walls of buildings 
 with a cavity 2 to 3 inches wide between the external and internal faces of 
 the wall, and to join the tAvo portions of such wall together by means of 
 bonding ties of some non-absorbent material placed at suitabis distances 
 apart. Sometimes these bonding ties are made of iron, sometimes of glazed 
 stoneware, and such walls, if properly constructed, are generally sound 
 and sufficiently stable for all practical purposes, while they greatly promote 
 the comfort and dryness of the house itself. Other means of securing the 
 same condition of dryness have been contrived with more or less success, 
 such as a vertical damp-proof course of slates, or of asphalte or other bi- 
 tuminous substance. Compo or tiles or slates are sometimes used on the 
 outer face of the wall for the same purpose. 
 
 The third (c) condition above mentioned is intended to prevent the 
 passage of moisture vertically in the walls of the dwelling; hence the 
 
6G2 HYGIENE 
 
 damp-proof course must be laid throughout the entire thiclaiess of every 
 wall and at a level some 2 or 3 inches at the least above that of any- 
 ground adjoining the wall. It must also be below the level of any timber 
 or woodwork in or upon the wall, as such timber or woodwork obviously 
 needs the most complete protection from damp. The provision of an eflicient 
 damp-proof course in the external walls of a building may necessitate the 
 formation of a sunk area against the wall in order that the earth may be 
 kept at a proper distance from that part of the wall which, being below 
 the general level of the ground outside, is above the level of the damp- 
 proof course. • This is essential if the dryness of the wall is to be preserved.. 
 Modifications of this kind of construction have sometimes been adopted by 
 which the outside of that part of the wall which is above the level of the 
 damp-proof course and beloAV that of the adjacent ground has been covered 
 with asphalte or other impervious material, or that part of the wall has been 
 constructed with a cavity and a second damp-proof course at the level of the 
 top of the caAdty ; but these are contrivances more adapted to meet the re- 
 quirements of certain exceptional circumstances, and need not here be referred 
 to in further detail. A damp-proof course is often requisite in the case of 
 chimney stacks and parapets in order to prevent damp from driving rain 
 soaking downwards from the exposed upper portions of walls of buildings. 
 
 The fourth point {d) above referred to is the construction of the roof of 
 the dwelling of such material and in such manner that it will serve its pm'pose 
 of efficiently protecting the interior of the dwelling from the weather — wet,, 
 heat, and cold. Eoofs are covered most frequently with slates or tiles, but 
 sheet lead and zinc are occasionally used for the purpose, and almost invari- 
 ably for gutters and valleys, cast iron being most commonly used for eaves^ 
 guttering. Thatch, though affording perhaps the greatest opportunity for 
 IDicturesqueness, is now rarely used for new dwellings, as it is less durable 
 than the other materials, and is regarded as a possible source of danger from 
 fire. It is, moreover, not free from objection on sanitary grounds, since it is 
 entirely vegetable in its nature, and therefore undergoes comparatively rapid 
 decomposition, which is encouraged by the changes of weather to which it is 
 exposed. It likewise affords harbour for insects and vermin, and has been 
 suspected of retainmg the infection of scarlet fever after that illness had been 
 under treatment in a cottage with such a roof.^ Slates, if properly laid and 
 with a good ' lap,' ^ which ought not to be less than three inches, may perhaps 
 be regarded as affording the best ordinary roof-covering in our climate, but 
 they ought invariably to be laid on boarding and felt, and not merely on 
 laths as is too frequently the case ; otherwise they allow the interior of the 
 house to be unduly affected by external temperature. In this respect tiles 
 have the advantage, as they afford a better protection from heat and cold. 
 A tile roof has to be constructed with a steeper pitch than a slate roof, as 
 the latter material affords greater facility for rain water and snow to run off 
 than a tile-covered roof. It is, of course, necessary to provide suitable gutter- 
 ing along the eaves and elsewhere, to collect the water from the roof before 
 conveying it away down the rain-water pipes. And, as regards these latter, 
 it is desirable to fix them at a short distance from the walls of the building 
 in order to protect the walls from damp in the event of a down pipe getting 
 stopped up. Cast-iron rain-water pipes are often made with a special fas- 
 tening that keeps the pipe itself an inch or two away from the face of 
 the wall. 
 
 ' Our Homes, p. 8. Loudon : Cassell & Co., 1883. 
 
 2 The ' lap ' in slating is the distance that each row of slates overlaps the head, or 
 upper edge, of the second row of slates below it. 
 
THE DWELLING GG3 
 
 The fifth point (e) referred to concerns the light and ventilation of the 
 dwelling, and although the latter forms the subject of a special article else- 
 where, it may nevertheless be useful to draw attention to certain features that 
 are indispensable to the dwelling under this head. First there is the necessity 
 for providing adequate open space, not only at the rear of every dwelling, but 
 also in front thereof, and the importance attaching to this provision is shown 
 by the stringency with which regulations for securing the requisite minimum 
 amount of space are laid down in the Model Bye-laws, already referred to. It 
 is there prescribed (clauses 63 and 54) that a clear distance of open space, 
 at least twenty-four feet across, measured to the opposite side of the street, 
 if necessary, is to be provided in front of every new dwelling-house, and also 
 that an open space belonging exclusively to it, extending laterally throughout 
 the entire width of the building, is to be provided at the rear, measuring from 
 a minimum of ten feet up to twenty-five feet across such space, according to 
 the height of the building, of every new dwelling. It is further prescribed 
 (clause No. 55) that adequate windows are to be provided in each storey of 
 the building in the walls which abut upon the open space so required to be 
 provided ; and likewise (clause No. 57) that every room intended for the 
 purpose of habitation shall have at least one window, the size of which is to 
 bear a proportion of one-tenth of the floor area of the room, that such window 
 is to be made to open to at least half its size, and so that the opening may 
 extend to the top of the window. These regulations thus have the beneficial 
 effect of practically prohibiting the use of skylights in substitution of proper 
 vertical windows, for the purposes of lighting and ventilating every room in a 
 dwelling. So also with regard to the ventilation of a water-closet or earth- 
 closet in a dwelling house ; not only ought it to be furnished with at least 
 one window of a minimum superficial area of about two square feet, opening 
 directly into the external air, but it should have, in addition, a second opening 
 of some sort, such as 2-inch Tobin tube or some kind of ventilating air 
 brick, in order to promote the circulation of air through the closet indepen- 
 dently of the air of the house itself. These requirements, which, where 
 carried out, greatly tend to keep the air of the closet piwe by the rapid removal 
 of offensive odour, are specially prescribed in the Model Bye-laws (clause 
 No. 68). 
 
 The details of the sixth point (/), relating to the removal of the liquid and 
 solid refuse from the dwelling, are likewise dealt with elsewhere, but it is 
 necessary here to refer to the arrangements that are requisite for receiving 
 the filth and refuse before they pass into the channels of removal. These 
 arrangements usually comprise the ordinary water-closet apparatus, dry earth 
 closets, and privies of various descriptions, and slop sinks, likewise ashpits 
 and dustbins. These appliances, in one defective fprm or another, have been 
 the cause of more injury to health than perhaps all other causes together. 
 Water-closets, by bringing drains leading to sewers and cesspools directly 
 into the dwelling, have poisoned the air within ; and badly contrived privies 
 and ashpits outside the dwelling have poisoned the air and soil about the 
 exterior of the dwelling, as well as the water used by the inhabitants. And 
 thus they have combined to inflict upon the people those terrible 'filth 
 diseases,' as Sir John Simon has so aptly described them in his official re- 
 ports, ^ as Medical Officer of the Privy Council and Local Government Board, 
 which have not only carried off such vast numbers of persons, but have from 
 time to time attacked and prostrated a still greater number. Under these 
 
 1 See especially the report on ' Filth-diseases and their Prevention ' in the Supple- 
 mentary Report for the year 1873. New Series No. II. [c— 1066.] London : Eyre & 
 Spottiswoode, 1874. 
 
GGi HYGIENE 
 
 circumstances the question of the precise kind of closet apparatus to be 
 adopted, whetlier on tlie water principle or on some of the dry principles, is 
 a matter of much importance. The leading;- principles to be observed in either 
 case are dealt with in some detail in the several clauses of the Model Bye- 
 laws, already referred to (clauses Nos. G7 to 79). These clauses may be said 
 generally to cover the whole subject, since they prescribe the arrangements 
 to be followed in the construction of water-closets and of earth-closets and 
 prices, wdth either fixed or with movable receptacles. After setting forth 
 that every new water-closet or earth-closet is to be so placed and constructed 
 as to ensure its ethcient ventilation, the bye-laws require every new water- 
 closet to have its separate cistern or flushing-box furnished with means for 
 efiectually flushing and cleansing the basin of the closet, and for removmg 
 the excreta therefrom. This requirement practically prohibits the use of 
 closets in which the objectional plan of hand flushing — i.e. the occasional 
 emptying of a pail of water into the basin, is relied upon. The necessity, 
 for sanitary reasons, for providing the separate cistern is explained later 
 on ; ' but, as regards its capacity and position, it may here be pointed 
 out that in order to make the flush eftectual, both as regards volume and 
 force, it is requisite to fix the flushing-cistern at least four or five feet 
 above the closet-basin, and to provide a pipe from the cistern to the basin of 
 at least 1} inches diameter. The quantity of water requisite to flush out 
 the basin and carry away the excreta will depend to some extent upon the 
 particular form of basin and the kind of trap beneath it, but it will rarely be 
 found that less than two gallons will answer the purpose, and even this will 
 often fail to remove it further than from the basin to the trap, where the 
 solids will remain until the next time a flush is applied. For more effectually 
 flushing the trap and soil-pipe, as well as the basin, it would be better to 
 use three gallons of water at a time. This quantity, though objected to by 
 many water companies, has been advocated as necessary by many sanitary 
 engineers and others who have paid special attention to the point, and the 
 only alternative that can be recommended is to apply a second flush each 
 time the closet is used. To this, however, a difficulty has been interposed 
 in the interests of the water companies, by which, owing to the small size of 
 the pipe supplying the flushing cistern "v\ith water, the time occupied is so 
 great that few persons are willing to wait while the flushing cistern is 
 getting re-charged, after the first flush has been applied to the basin. In some 
 instances as much as eight or ten minutes elapse before it is full, and con- 
 sequently, as the application of the second flush recommended is rarely 
 practicable, it is better to insist upon the larger capacity of the cistern. But 
 if the supply-pipe were so enlarged as to fill the cistern in, say, two minutes, 
 the smaller capacity might possibly be regarded as adequate, a second flush 
 being recommended on every occasion the closet is used. 
 
 The Model Bye-laws next require the water-closet to have a basm of non- 
 absorbent material, and of such shape and capacity, &c., as will contain a 
 sufficient quantity of water, and will allow the excreta to fall free of the 
 sides, and directly into the water in the basin. This requirement, which is 
 necessary in the interests of cleanliness, practically prohibits the use of the 
 long hopper-shaped closet-basin (fig. 108) so commonly met with in cottage 
 closets and in servants' closets, and in which the excreta invariably hang 
 about the sides and fail to be removed by the sluggish flow of water in a 
 spiral course round the basin. The ordinary valve-closet basin shown in 
 fig. 109 obviously conforrus with this re(|uirenaent, and is one of the best 
 
 ' See p. CC7. 
 
THE DWELLING 
 
 665 
 
 ■■(sssaEi 
 
 ..f.'j/jjj/jjjj}, 
 
 Fig. 108. 
 
 FxG. IIL 
 
 Fie. 109. 
 
 Fig. 112. 
 
 Fig. 110. 
 
 Fig. 113. 
 
G6G HYGIEXE 
 
 forms of closet apparatus, especially when made with a spout or lip on the 
 edge of the basin to serve as an overflow into the safe below, instead of the 
 overflow-pipe dehverhig beneath the valve as shown in fig. 110. Other forms 
 of closet-basin complying with this requirement are shown in the * wash- 
 out' and hopper-shaped basins in figs. Ill and 112. The same Model 
 Bye-lav\^ (clause 69) next proceeds to prohibit the fixing in any new water- 
 closet of what is known as a 'container' and 'D trap.' These appliances 
 were, for many years, most common. They are still often used notwith- 
 standing their general condemnation by sanitarians, and are met with all 
 over the kingdom, as well as in Continental towns. A section of this kind of 
 apparatus, with the ' container ' and ' D trap,' is given in fig. 113 and fig. 114, 
 showing as nearly as possible the actual state of the interior of the trap after 
 a few months' use. The two appliances referred to involve the retention of 
 excreta in them, often for many hours together, with the result that the sides 
 get coated over with a filthy slime or deposit which emits that offensive and 
 nK)st unwholesome odour invariably met with in these closets when the 
 handle is pulled up for the basin to be emptied. The interior of these appli- 
 ances not being subjected to the full force of the flush of water in the basin, 
 the filth gets deposited over it in the way shown, and this process of deposit 
 is much aided in the container by the use of iron, of which the container is 
 usually made. 
 
 As regards the seventh point (g), the means of storing and distributing 
 water, it is of the utmost importance that the arrangements generally should 
 
 admit of an unstinted supply being 
 available to the inmates of every dwelling. 
 The amount per head per diem that 
 is requisite in an ordinary dwelling 
 depends necessarily upon a great variety 
 of circumstances, and is dealt with in 
 another part (see p. 243). 
 
 Where the supply is on the constant 
 system cisterns are still requisite, as the 
 supply, being through a small tap, is not 
 always as rapid as may be temporarily 
 necessary, and, moreover, when it is 
 cut off for a few hours during the repair 
 ^^°- 1^^- of a main, much inconvenience might 
 
 arise if there were no storage-cistern of moderate capacity ; but the size 
 might be very much smaller than where the water is supplied on the inter- 
 mittent system. On the other hand, there is some disadvantage in the 
 cistern being of excessive size, as the water in it may in that case not be 
 changed sufficiently often, and thus become affected by stagnation. 
 
 For the storage of the requisite quantity of water, tanks or cisterns are 
 usually provided at such height above the ground as will allow of the water 
 beinf^ dehvered by gravitation where it is wanted below the level of the 
 cisterns. These cisterns are ordinarily made either of slate, iron, lead, or 
 wood lined with lead or zinc, and are fitted with a ball-cock or valve to regu- 
 late the admission of water from the main supply according to the level of 
 the surface of the water in the cistern, and an overflow- or warning-pipe to 
 indicate when the cistern is full, or when the ball-valve may be out of order, 
 to ob^date the inconvenience of the cistern overflowing. There are serious 
 objections to the use of lead for cisterns, as certain water, especially rain- 
 7/ater or soft-water, will readily become poisoned by the lead ; and this 
 objection also apphes, in a less degree, in the case of zinc cisterns. Iron is 
 
THE DWELLING CG7 
 
 likewise not free from objection, unless covered with some suitable protective 
 material. Slate, especially if enamelled, is probably the best material for 
 cisterns, though there is some difficulty in making the joints permanently 
 watertight, and therefore such cisterns should always have a proper safe or 
 tray beneath them to prevent leakage from soaking into the building beneath. 
 Every cistern ought to be so placed as to be easily accessible for the purpose 
 of inspection and periodical cleansing, which ought to be done at intervals of 
 not more than about three months. In order that this cleansing of the 
 cistern may be effectually done it is necessary that there should be ample 
 means for the admission of light to it ; but the water in a cistern or tank 
 should not be constantly exposed to light, as this would tend to encourage 
 algoid growth in the water. It ought also to be covered over in order to 
 prevent dust, leaves, and other substances, as well as mice, small birds and 
 insects, from getting in ; and should likewise be well ventilated, and protected 
 from extremes of temperature. Special precautions should be taken if the 
 cistern is placed in a position where the water in it may be expected to 
 freeze in cold weather, as the expansion of the water when frozen may lead to 
 the joints of the cistern being damaged and result in much inconvenience 
 when a thaw sets in. Unless the cistern is protected in some way, it should 
 be made with sloping sides, the top being wider than the bottom in order to 
 allow the water, in the process of freezing, to expand upwards without exer- 
 cising much pressure on the sides. 
 
 For the purpose of facilitating repairs to the cistern or to the service- 
 pipes leading therefrom, without arresting the distribution of water about 
 the house, it is often useful to arrange the cistern in two compartments, one 
 feeding the other and both connected with the service-pipes, but fitted with 
 stop-cocks so that the service-pipes could draw their supply from either of 
 the compartments while the other was temporarily emptied for repairs, 
 cleansing, &c. So also the service-pipes would, in that case, be capable of 
 being shut off from the cistern by means of the stop-cocks and be emptied 
 for repair or for replacing a defective draw-off tap, or on the approach 
 of very cold weather, when the water in the pipes might be expected to 
 freeze. 
 
 It must always be borne in mind that the water-supply to the water- 
 closets of a house must not be direct from the main supply-pipe, or from any 
 of the storage cisterns supplying water used for dietetic and domestic purposes. 
 Numerous instances are recorded showing that outbreaks of enteric or typhoid 
 fever have resulted from supplying water to water-closets direct from the 
 water main, instead of through the intervention of a cistern. Under such 
 circumstances, any intentional or unavoidable intermission of the water- 
 service facilitates and ensures the forcible suction of foul air, and, at times,. 
 even other matters, into the mains of the water-service. Hence service- 
 cisterns ought to be provided, in order to ensure a complete break between the 
 basin of a water-closet and the water-main ; and inasmuch as, even where 
 such a cistern is provided, there still remains a tendency for the escape of 
 foul air from the basin of the closet up the service-pipe and through the body 
 of water in the cistern itself, thus leading to contamination of the water, 
 a special cistern is necessary exclusively for the water-closet, and what is 
 known as a water waste-preventing cistern, similar in principle to what is 
 commonly required by the water companies, answers the purpose efficiently. 
 
 It may be useful here to refer briefly to certain objections to the inter- 
 mittent system of water-supply — objections which apply equally to cases where 
 the so-called constant supply is in use, but, from scarcity of water during 
 periods of drought or otherwise, not continuously in operation. It has on 
 
CG8 HYGIENE 
 
 several occasions happened that, under such circumstances, the suction 
 into the pipes has been such that various contaminating matters, as foul air, 
 sewage and focal matter, blood from slaughter-houses, &c., have been drawn 
 into the pipes, and subsequently distributed in the water, with the result that 
 fever was produced in the neighbourhood. 
 
 For the distribution of water about the dwelling lead pipes are usually 
 adopted ; but as certain waters act upon any lead with which they may come 
 in contact and become poisoned, it would be better if pipes of some other 
 material were adopted. But there are so many advantages in the use of lead 
 pipes, and the evil results, where the water is not allowed to remain long in 
 them, are so rarely serious, that it is almost useless at present to urge the 
 adoption of other pipes. Tin pipes, or tin-lined leaden pipes, however, have 
 in some instances been used with much advantage. 
 
 Turning now to the consideration of the several classes of dwellings above 
 enumerated, we come Jirst to the class of mansions and palatial residences of 
 the rich, and perhaps there is less to be said about them hygienically than 
 about any of the other classes, partly because they are usually constructed 
 under the exceptional advantages of liberal expenditure and good professional 
 advice, partly also because, as regards air-space both within and ^\-ithout, 
 there is usually much less necessity for stint than in the case of dwellings of 
 the other classes, and partly because they are not always in full occupa- 
 tion. There are, nevertheless, some points about even this class of house, 
 both ancient and modern, that need more attention than is often bestowed 
 upon them, and indeed instances are not wanting to show that grave defects 
 have been allowed to exist in some old mansions, or to be created in some 
 new ones, which have resulted in more or less serious effect upon the mhabi- 
 tants, sometimes affecting the servants, sometimes the visitors, and some- 
 times the members of the family OAvning and occupying the mansion. 
 These defects have been apparent mainly in the matter of the drainage or 
 sewerage arrangement, though the imperfections of water-closets, and the 
 absence of any sort of disconnection between the interior of the house and 
 the drains, have also, in many instances, come to be Imown as the direct 
 cause of disease. There are, however, certain other defects common in the 
 class of house referred to that may have a considerable influence on the 
 health of the inmates. That they are in some instances unduly crowded on 
 area, especially in the case of mansions situated in the metropolis, can hardly 
 be denied : for in such cases it is common to find the building covermg the 
 entire area of the site, while one or more small courts or wells, intended for 
 ■ light and air, descend in the middle from the top as far as the roof of the 
 ground storey, where skylights alone afford to the rooms and offices below 
 them such poor supply of light and ventilation as may chance to be avail- 
 able, and windows around this well of stagnant air are supposed to suffice 
 for a number of rooms, &c., abutting upon it. Inasmuch, however, as these 
 houses are commonly more or less empty during the greater part of every 
 year, and are only fully occupied during a short season of annual festivity, 
 this defect, which in the case of an institution always occupied to its full 
 capacity would be most serious, can hardly be said to apply. 
 
 There is a curious instance of a design for a mansion on what may be 
 called the pavilion system. A celebrated architect, John Thorpe, who lived 
 in the time of Queen Elizabeth, and who designed and carried out many man- 
 sions and palaces at that period, has left an interesting design for a house for 
 himself, but which was not erected. This design is preserved in Sir John 
 Soane's museum in Lincoln's Inn Fields, and is in the form of his own initial 
 letters I and T, the portion of the building comprised in the letter I containing 
 
THE V WELLING 
 
 GG9 
 
 Fig. 115. — Plan of John Thorpe's house. 
 
 the kitchen offices and servants' quarters, and that comprised in the letter T 
 containing the principal rooms and residential apartments of the house, the 
 two letters being joined 
 together by means of a 
 one- storey connecting cor- 
 ridor. The author of the 
 design facetiously explains 
 it in the following doggerel 
 rhyme : — 
 
 Thes 2 letters I and T 
 
 ioyned together as you see 
 Is ment for a dwelling house 
 for mee 
 
 John Thorpe. 
 
 Although Thorpe's prime 
 object was no doubt to 
 arrange his plan in the 
 
 form of his own initial letters, there was considerable advantage in the 
 effectual separation of the culinary department from the main residential por- 
 tion of the house ; but, even if this idea formed a basis for the arrangement, it 
 was only partially adopted, since the upper storeys of the portion compris- 
 ing the letter I appear to have been intended for residential apartments, pro- 
 bably for the servants. 
 
 One of the chief sanitary defects in old mansions is the method of dis- 
 posal of the sewage. In the country this has generally been conveyed first 
 into subsiding tanks or cesspools and then into some lake or ornamental 
 piece of water, or into some stream or river. In towns and in the metro- 
 polis this use of cesspools has been very largely resorted to before the Liquid 
 has been allowed to flow into the sewers or directly into the river. These 
 conditions still exist in the case of very many large mansions, notwith- 
 standing that the arrangements described are directly prohibited by modern 
 Acts of Parliament, and that the owners of such mansions are frequently 
 themselves members of one or other of the Houses of Legislature, or are 
 otherwise concerned in the making and administration of the laws of the 
 land. Here and there, where grave insanitary conditions have been dis- 
 covered or where illness or perhaps death has resulted from these conditions, 
 remedies or improvements have been effected ; but these would seem to be 
 but comparatively isolated instances. It was only after severe illness in 
 the house that the site upon which Marlborough House stands was dis- 
 covered to be dotted about with old cesspools and traversed by old drains, the 
 very existence of which was unknown, but which served to saturate the 
 ground beneath the house with filth. This discovery, in 1877, naturally 
 led to very extensive and costly works, comprising the removal of all the old 
 cesspools and drains as well as the contaminated earth, the construction of a 
 new system of drains external to the house, and the covering of the ground- 
 surface within the house with a layer of Portland cement concrete.' Again, 
 in this class of house grave results have repeatedly arisen from the position 
 and construction of the water-closet practically necessitating the drains being 
 brought close up to, or even within, the bedrooms and private apartments of 
 the household, the closet itself having no independent ventilation, and con- 
 stantly delivering subtle poisons into the inhabited rooms. So, too, the 
 domestic offices, larders, pantries, and dairies have been found to be placed 
 
 ' The Builder, 1877, p. 1251. 
 
G70 HYGIENE 
 
 ■where the servants, as well as the food, have been exposed to the effects, not 
 merely of bad drainage arrangements, but of ah' that has been vitiated in 
 vai'ious ways, perhaps most often by damp and other exhalations from the 
 ground. While in many old houses of this class the defective and unwhole- 
 some arrangements above described are allowed to remain undisturbed, 
 on account of the wholesale character of the alterations that would be 
 necessary were they to be remedied, it must be admitted that, in those 
 mansions of quite recent construction, the more obvious defects, at any rate, 
 have generally been carefully avoided. 
 
 As regardsthe second class of dwellings referred to at page 058, the sub- 
 urban and country house of the ordinary professional man of business and 
 wealthy tradesman, the parsonage or vicarage, and the better kind of farm- 
 house — these are far more numerous than the dwellings comprised in the 
 first class, and in many respects they may be said to contain the same 
 general characteristics as the latter, but in a somewhat modified form. In 
 a vast number of instances the same kind of defects may be found in this 
 class of house as in the first class, but in the main the houses in the second 
 class are, with the exceptions referred to, fairly well adapted to their purposes. 
 There are, however, some features about them that mi;st be briefly referred 
 to, such as the circumstance that they are usually more permanently occu- 
 pied than the palatial mansions, and accordingly any defect is more 
 likely to produce more intense effect than where the dwelling is allowed to 
 remain empty for a certain period every year. Then, again, in this land 
 of dwelling the inferior apartments, such as the bedrooms set apart for 
 servants, are often so placed and constructed as to be indifferently warmed 
 and ventilated, or so as to be readily affected by external temperature, 
 or they are placed in undue proximity to the domestic offices, stables, 
 &c., and so that the smell from these places is never absent from the 
 apartments. 
 
 In the case of vicarages and rectories, the fact of their being periodically 
 overhauled by officers of the Ecclesiastical Commissioners or the Diocesan 
 Surveyor, whenever there is a change of the incumbency, leads to their 
 being generally kept pretty well up to date in regard to most of the ordinary 
 hygienic requirements, while, as regards new parsonages, they have to be 
 erected in conformity with the somewhat stringent requirements of the 
 Ecclesiastical Commissioners, and although these may not always be as 
 complete and effectual as the hygienist w^ould desire, they are, nevertheless, 
 very useful in securing substantial construction on sound general principles. 
 
 The third class of dwellings to which reference has been made involves 
 certain difficulties of arrangement which are seldom met with in connection 
 with the two precedmg classes of dwellings. With this class, which is more 
 urban in character than the country-house already referred to, commences 
 the embryo of that important question of adequacy of open space about 
 the dwelling, both to the front and to the rear, in order to ensure facilities 
 for free circulation of air about the house and opportunity of ventilating the 
 interior. Owing to the greater value of land in the urban district than in the 
 open country, this difficulty increases in proportion as the dwelling is nearer 
 to the centre of the urban district, where, owing to the exigencies of popula- 
 tion, trade, and business, the houses are necessarily packed somewhat closely 
 together and built of great height. Lideed, every new building that is 
 erected on the site of an old one is often made fully twice as high as its pre- 
 decessor. To such an extent is this the case in some localities that dwellings 
 have to be piled one on the top of another, many storeys in height, under the 
 same roof, under the modern denomination of ' flats.' Accordingly, under 
 
THE DWELLING 671 
 
 this head are comprised the ordinary detached and semi-detached house of 
 moderate size, and the terrace-house, or house in a row of attached houses of 
 indefinite length, of size and value varying from the ten- or twelve-roomed 
 house, of a rental of some sixty or seventy pounds a year, to the town-house 
 of two or three times that size and eight or ten times the rental value, 
 situated in the best residential streets at the West -end of the metropolis and 
 of the provincial towns. The system of flats, which is a modern innovation 
 from the Continent, possesses many advantages, when well carried out, over 
 certain classes of houses for the middle classes in the ordinary streets of 
 London and other towns. It may he described as that of laying the ordinary 
 tall house down horizontally. Such a house obviously occupies a larger area 
 than the same accommodation arranged vertically in the one house of some six 
 or seven storeys ; but, on the other hand, the entire block of flats may be 
 several storeys high, and at least as many sets of flats or dwellings can be 
 arranged on the same area. It would also be possible to arrange the several 
 dwellings in various sizes to suit the requirements of different tenants. The 
 advantage gained by throwing the several small backyards separated by the 
 party fence walls that would have to be provided behind the row of tall narrow 
 houses, into one undivided yard of considerable length would alone be con- 
 siderable, while if, in the case of a site lying between two streets, the court- 
 yards were arranged to communicate with the streets by means of clear 
 openings or large archways, the advantages as regards circulation of air 
 would be greatly increased. As an indication of this latter arrangement an 
 excellent plan,^ designed by Mr. "William H. White, F.E.I.B.A., was laid 
 before the Eoyal Institute of British Architects in 1877, showing how the 
 block of twenty-eight London shops and dwellings lying between Eegent Street 
 and Warwick Street on their west and east, and Beak Street and Eegent Place 
 on their north and south, have from time to time been altered and inter- 
 mingled, until they have become only twenty in number, and practically the 
 entire area has been gradually covered with building, for only four or five 
 very small well-holes remain open for light and air, the frontages of the 
 buildings extending continuously all round the site. By the rearrangement 
 and reconstruction of the buildings on this 'island,' Mr. White shows that 
 as many as twenty-one shops and nineteen good and roomy houses might be 
 constructed upon it, while the courtyards would be such as would ensure free 
 circulation of air and ample light. One important feature that appears re- 
 quisite to bear in mind in the case of a block of dwellings arranged as ' flats ' 
 is the advisability, in the interests of health, of so arranging the common 
 staircase or staircases that, if they are not open to the external air, they shall 
 at least be capable of good through-ventilation by opposite external windows. 
 This would be of special advantage as tending to prevent the spread of 
 infection in the event of any dangerous infectious disease occurring in any 
 dwelling in the block. 
 
 The kind of dwelling comprised within the fourth class above alluded to 
 — namely the dwelling in connection with the place of business, the hotel, 
 inn, &c. — is very numerous, and includes not only the ordinary ten- or twelve- 
 roomed house with a shop in the ground storey, but the large drapery esta- 
 blishments and other commercial houses where the upper part is devoted to 
 apartments for the numerous employes of both sexes engaged in the service 
 of the establishment, and who in some instances are many hundreds in 
 number. In this sort of dwelling the question of open air space about the 
 house is often involved in much difficulty, for the chief value of the premises 
 
 ' Illustrated and described in tlie Transactions of the B.I.B.A., and also in Our 
 Homes. London : Cassell & Co., 1883. 
 
672 HYGIENE 
 
 lies in their capacity for the purposes of business, and accordingly the super- 
 ficial area available for shop purposes in the ground storey — or more particu- 
 larly at the street level— with such additional space for showrooms, ware- 
 rooms, and the Hke, in immediate connection with the shop, constitutes the 
 chief element in the value of the premises from the purely business point of 
 view. Hence everythingis sacrificed to increasing the area available for business 
 requirements, and unless some control be exercised over the arrangements, 
 the health conditions of the premises are undoubtedly prejudiced. Thus in 
 all such cases the first effort is to secure the largest area possible for the 
 shop, and accordingly this is extended over the entire area of the site from 
 front to rear boundary, so as to preclude the possibihty of forming any sort 
 of yard at the ground level where the necessary ashpit or dustbin may be put, 
 and so as to exclude all means of lighting and ventilating the basement storey, 
 except from a sort of shallow area beneath the shop window in front. Some- 
 times palhatives for these defects are provided in the shape of reflectors for 
 light and air-shafts for ventilation ; but these, as a general rule, hopelessly 
 fail to effect their purpose to the necessary extent, since gas or other artificial 
 light has often to be constantly used, and the ventilation of the basement is 
 left to take care of itself; and this notwithstanding that dozens of young 
 men and women may be employed in this storey during many consecutive 
 hours from morning till evening. Nor is this all : it is not uncommon to 
 find in this artificially lighted and imperfectly ventilated basement the closet, 
 urinal, and lavatory accommodation for certain of the employes, which is 
 merely screened off, so to speak, from the main apartment, and is utterly 
 incapable of being maintained in a proper and wholesome condition, however 
 well it may be kept by those servants immediately responsible for its clean- 
 liness. 
 
 In the shop itself the ventilation mainly relied upon is generally the front 
 doorway, which is kept open for customers as much as possible, and some 
 skylights having a small portion to open, over the rear portion of the shop ; 
 but this is rarely sufficient to keep the air within it even moderately pure. 
 The quantity of gas frequently consumed in large shops, the ascent of ^'itiated 
 air by the stairs from the wareroom or offices in the basement, the exhala- 
 tions from the large numbers of employes and from customers, as well as the 
 emanations from the clothes of the latter, particularly in wet or warm weather, 
 and the dust, particles of fibre, and smell from the stock and goods in the 
 shop, all combine to render the atmosphere vmwholesome. Add to this the 
 conditions of fatigue, posture, long hours, &c., under which the employes have 
 to perform their vrork, and it will be seen that the conditions are often far 
 from satisfactory. It further frequently happens that the sleeping apartments 
 of the employes are so placed in the house above the shop and showrooms 
 that the products of combustion of gas and the other deleterious conditions 
 of the air in the shop are easily conveyed by ill- ventilated staircase and passages 
 to the upper storeys, and thus contaminate the air in which the employes 
 pass the night. There are many establishments where these defects, if they 
 exist at all, have been reduced to a minimum — where the whole condition, 
 bygienically, mentally, morally, and physically, of the employes is the constant 
 care of the principal and his higher staff' — but there are also numerous others 
 where a very cursory inspection will demonstrate the necessity for improve- 
 ment, while in the case of the erection anew of such establishments it ought 
 not to be difficult to so contrive them as to obviate most of the defects referred 
 to. There is, however, one further point affecting the hygienic conditions of 
 such establishments to which attention should be directed, and this is the 
 amount of closet accommodation that is requisite for the employes of each 
 
THE DWELLING G73 
 
 sex. In some instances it has been found wholly inadequate to the numbers 
 employed, the number of the latter having increased with the extension of 
 business ; in other instances it has been found to be so arranged as to be not 
 readily available, or to be so improperly separated, that for one sex from that 
 for the other sex, as to tend to prevent that regular use of these conveniences 
 which is essential to health. 
 
 The hotel, inn, public-house, restaurant, and other dwellings of that cha- 
 racter, undoubtedly demand more serious attention from a hygienic point 
 of view than they have perhaps hitherto generally received. In the 
 modern palatial hotel much has been done to avoid many of the defects 
 that are common in the old-fashioned hotels, though even here defects of 
 want of light and air consequent upon the effort to crowd too much building 
 upon area are of too frequent occurrence. But all who have occasion to stay at 
 the old-fashioned family and commercial hotel or inn, especially in the older 
 cathedral towns and in most market towns, will be intimately acquainted 
 with the close, fusty atmosphere within its walls. At night, on retiring 
 to his bedroom, the visitor will find it impossible to escape the smell of cook- 
 ing and the odours from the bar-parlour, together with the products of com- 
 bustion from the numerous gaslights and lamps. On opening his bedroom 
 •door in the morning to take in his boots and hot water, he will encounter 
 the strong smell of fried bacon, fish, coffee, and other preparations for 
 breakfast ; and he will be fortunate if, during or after his stay in the hotel, 
 he do not suffer from the effects of defective or obsolete forms of water-closet 
 arrangement and fittings, the ill-contrived chamber-maid's slop-sink, and 
 the badly arranged and rarely cleaned cistern in near proximity to his 
 apartment. To the casual visitor these objectionable conditions may perhaps 
 be of comparatively small moment, but to the numerous servants who pass 
 their whole time on the premises, night after night and day after day, the 
 ■effect is probably more serious, and goes far to account for the pallor and 
 eallowness of complexion so commonly met with among this class of servants, 
 who, moreover, frequently occupy only indifferent apartments and have very 
 poor accommodation,^ barely complying with rules that would ordinarily be 
 laid down for the prevention of overcrowding. In a certain class of modern 
 hotel, where convenience of detail has been sacrificed to external appearances, 
 the size of the windows is so large, and indeed out of all proportion to the 
 size of the rooms, that much difficulty is experienced in opening them, and 
 consequently there is a tendency to keep them permanently shut ; a tendency 
 which is encouraged by the chamber-maid's desire to prevent the entry of 
 dust and soot, with which the atmosphere of our larger towns, such as 
 Birmingham, Manchester, Sheffield, Leeds, &c., is so loaded. 
 
 The fifth class, concerning as it does the millions, is necessarily the most 
 numerous of any class of separate dwelling. It is, moreover, the class that 
 may be said to call for more control and supervision than any other class of 
 dwelling, since the comparatively small cost of each dwelling affords a larger 
 scope for building speculation than in the ease of more costly dwellings. At 
 the same time it must be admitted that a vast amount of good has been, and is 
 still being, done by philanthropic individuals and societies to provide v/hole- 
 some and decent dwellmgs for this large class of the community, both in 
 town and country. In this respect the wage-earning classes are more 
 fortunate than that stratum of the lower middle class, which is composed of 
 persons who earn, as yearly salary or income, scarcely more than is paid in 
 
 ' An instance has come under the notice of the writer where in a well-known and 
 reputable tavern-hotel the night porter occupied by day the same bed that a lad in the 
 service of the hotel occupied by night. 
 
 VOL. I. XX 
 
674 HYGIENE 
 
 weekly wage to many a jobbing mechanic, but who is nevertheless obliged to 
 keep up some appearance of gentihty. For while the artizan and mechanic 
 can choose a dwelhng either in a sort of town of well-built houses, or in a. 
 block of so-called 'industrial dwellings,' specially erected for his class under 
 the competent professional supervision furnished by the aid of some admi- 
 rably administered building society or philanthropic association formed for the 
 special purpose of providing cheap and good houses for this class, the clerk, 
 the draughtsman, the poor clergyman, and a host of others of that class, are 
 obliged to seek a house among those erected almost exclusively by speculating 
 builders, with only indifferent supervision, and the majority of which have 
 been built under no sort of skilled professional advice whatever. There are,, 
 it is true, many dwellings, modern as well as old, occupied by the wage- 
 earnmg community which from various causes are sadly defective in some of 
 the most important features of good hygienic arrangement, but, as a general 
 rule, an amount of professional skill, both medical and architectural, is now- 
 adays brought to bear upon the modern artizan's dwelling which is leading 
 to enormous improvements in construction and arrangement. This is partly 
 due to the general progress of sanitary knowledge as regards details of con- 
 struction, and, in its larger bearing, to the various Acts of Parhament which 
 have been passed by the Legislature in obedience to the demands of public 
 opinion for increased facilities for effectually dealing with so important a 
 subject. As regards the latter, some improvement has unquestionably resulted 
 from the application, during the period between 1870 and 1890, of what were 
 popularly known as Torrens's Acts ' and Cross's Acts.^ Some earlier Act& 
 for similar purposes, known as Shaftesbury's Acts, had been passed as long 
 ago as 1851, but these had never been put into operation, and remained 
 always a dead letter. All those Acts applied mainly to London and to 
 certain urban districts in the provinces. Torrens's and Cross's Acts, how- 
 ever, were found to involve serious cost and such cumbersome and slow 
 proceedings that numerous instances arose where, notwithstanding urgent 
 need for improvement, it was found almost impossible to apply them. 
 Accordingly, the Housing of the Working Classes Act, 1890 (53 and 54 Vict, 
 cap. 70) was passed, in order to consolidate the laws and to simplify the 
 procedure which had to be taken under the previous Acts, and under this 
 new Act the powers of improvement have been extended to rural sanitary 
 districts, where the local authorities are to exercise them, under the super- 
 vision of the County Councils. 
 
 The provision of healthy and convenient dwellings for the wage-earning 
 community has exercised the attention and ingenuity of philanthropists and 
 others in our own country as well as in certain foreign countries for now 
 nearly half a century. Li England shortly after the constitution of the Poor- 
 law Commission in 1834, following as this did soon after the first visi- 
 tation of epidemic cholera to this country in the year 1832, the subject of 
 the sanitary condition of the labouring classes attracted much attention 
 owing in a great measure to the statements made in the early annual reports 
 of the Commissioners as to the prevalence of disease among those classes ; 
 
 ' Mr. Torrens's Acts comprise the following, viz. 31 & 32 Vict. c. 130 (The Artizans 
 and Labourers' Dwellings Act, 1868) ; 42 & 43 Vict. c. 64 (The Artizans and Labourers' 
 Dwellings Act (1868) Amendment Act, 1879) ; 43 Vict. c. 8 ; and Part II. of 45 & 46 
 Vict. 0. 54 (The Artizans' Dwellings Act, 1882). 
 
 ^ Sir Richard Cross's Acts comprise the following : viz. 38 & 39 Vict. c. 36 (The 
 Artizans and Labourers' Dwellings Improvement Act, 1875) ; 42 & 43 Vict, c 63 (The 
 Artizans and Labourers' Dwellings Improvement Act, 1879) ; and Part I. of 45 & 46 Vict.. 
 c. 54 (The Artizans' Dwellings Act, 1882). 
 
THE DWELLING 675 
 
 and in 1842 an important report upon the whole subject compiled by their 
 secretary, the late Mr., afterwards Sir, Edwin Chadwick, K.C.B., was issued. 
 The press took up the subject, and notably the ' Builder,' under the able 
 editorship of the late Mr. George Godwin, F.E.S.,kept the matter well before 
 the public, losing no opportunity of describing the grave sanitary state of 
 dwellings generally, and those of the poor in particular, and of advocatmg 
 reform and improvement. In 1844 a society, having the late Prince Consort 
 aa president, was formed for improving the condition of the labourmg 
 classes, their prime object being to provide, either by alteration or adapta- 
 tion, suitable dwellings for those classes. In 1851 this society erected at 
 the International Exhibition in Hyde Park an excellent model block of four 
 dwellings which was subsequently re-erected at Kennington, where it may 
 still be seen. Other societies, such as the Industrial Dwelhngs Company, of 
 which Sir Sydney H. Waterlow is chairman,' and the Artizans', Labourers', 
 and General Dwelhngs Company have since been formed for providing suit- 
 able dwellings for the wage-earning classes, and the trustees of the funds 
 provided by the munificence of the late Mr. Peabody have also, since 1862, 
 when they commenced, done much for providing improved dwellings for 
 these classes in the metropolis. In the provinces various large employers of 
 labour have made great efforts to provide their employes and others with 
 good dwellings : this is especially the case at Saltaire, near Bradford, where a 
 very complete town has been provided by the late Sir Titus Salt. This town 
 includes, besides dwellings for several hundred workpeople, a church, schools, 
 lecture-room, library, baths and washhouses, &c. At Akroydon, near Halifax, 
 a somewhat similar village has been constructed under the auspices of Mr. 
 Edward Akroyd in conjunction with the Halifax Permanent Benefit Building 
 Society ; and at West Hill Park, Halifax, a similar scheme has been carried 
 out by the co-operation of the landowner (the late Sir John Crossley) and the 
 Building Society, under which the workman may become the owner of a well- 
 built, wholesome house on very advantageous terms. At Liverpool, Barrow- 
 in-Furness, Newcastle-on-Tyne, and other busy manufacturing towns, 
 much has been done in a similar way for the better housing of the labouring 
 classes. 
 
 On the Continent corresponding efforts were made for the same object. 
 In Paris the Emperor Napoleon HI., while President of the Eepubhc, 
 caused to be erected, in 1849, what was called a cite ouvriere — a huge 
 barrack, situated in the Rue Eochechouart — a scheme, however, which did not 
 prove very successful in any way, as the workpeople disliked being caserne, 
 or barracked. In 1852 a sum of ten million francs was allotted by the 
 Government for the amelioration of the labourers in the great manufac- 
 turing cities of France, and with this money various improvements were 
 effected in their dwelhngs. At Mulhouse (Alsace), Mons. Jean Dolfus, an 
 eminent manufacturer, and at the time mayor of the town, started in 1853 a 
 company, under the title of the Societe des Cites Ouvrieres, with a capital of 
 300,000 francs ; but as the system of housing the working classes in these 
 vast ' barracks ' proved very distasteful here as at Paris, it was unanimously 
 rejected by the Committee at Mulhouse in favour of a system of detached 
 blocks of four houses, mostly two storeys high, besides cellar and attic. This 
 Arbeiterstadt, or artizans' colony, now comprises upwards of 1,000 houses, 
 
 ' In the evidence of Sir Sydney Waterlow before the Eoyal Commission on the Housing 
 of the Working Classes (1884) it is stated (Q. 11,909) that this company alone had then 
 erected 4,314 tenements, accommodating 22,000 persons, while 665 additional tenements 
 for 3,000 persons were in course of erection, the average rent per room being 2s. l^cZ. per 
 week, which included rates, taxes, repairs and lighting of passages, and proper maintenance. 
 
 xx2 
 
€76 HYGIENE 
 
 each containing one or two families and provided with its own small garden. 
 There are likewise a large bath-house and washing-house, school for infants, 
 &c. The houses are said to have cost from 120/. to 150/. ; each and nearly all 
 have been sold to the workmen themselves at a very slight profit, the purchase 
 money being repaid by instalments. Similar schemes were carried out about 
 the same time at Gebweiler and at Beaucourt and elsewhere in France. The 
 late Mr. George Godwin, F.R.S., one of the Royal Commissioners for inquiring 
 into the housing of the working classes, m 1884, in a memorandum appended 
 to their report, after referring to the fact that advantageous arrangements for 
 housing the working classes by some of the large employers are made abroad, 
 describes what is known as the famiUstdre in connection with the estabhsh- 
 ment of M. Godin-Lemaire at Guise, near St. Quintin, in France, for the 
 manufacture of stoves and ranges. The workmen — 700 or 800 in number — 
 and their families are here housed in flats, three or four storeys high : nur- 
 series for infants, and schools for the children as they grow up, are provided, 
 and the whole is stated to have been carried on satisfactorily and profitably 
 for about twenty-five years. There has thus been a growing tendency in 
 England and France at any rate to provide improved dwelUngs for the 
 labouring classes in the more populous areas, and this tendency has extended 
 into Belgium and certain parts of Germany. As regards the provision of 
 improved dwellings for the labouring classes in the rural districts of the 
 United Kingdom, this, where it has been undertaken systematically, has been 
 done mainly by the landowners, and, to their credit be it said, the owners of 
 extensive domains in the country have put up some excellent cottages for 
 their workpeople. The Land Commissioners have issued a number of 
 sheets of plans for farm labourers' cottages which afford some excellent hints 
 as to suitable arrangement with strict regard to economy, some of which are 
 shown in figs. 116 to 124. 
 
 The cottage ordinarily provided for the agricultural labourer is generally 
 semi or wholly detached, since they are usually scattered about the estate. 
 Rows of cottages are less frequently erected for this class than for the 
 artizan classes, who have to be concentrated in more close proximity to their 
 work. The labourer's cottage ought to comprise a living room with small 
 scullery attached and at least three bedrooms, one for the parents and two 
 for the children. The most economical arrangement of this accommodation 
 is in a two-storey building, and in that case the loAver storey should have a clear 
 height between floor and ceiling of at least nine feet and the upper storey not 
 less than eight feet. The living room being the principal one, and the one 
 to be used by all the inhabitants in common, ought to be as large and com- 
 modious as practicable, with a minimum floor area of 150 square feet. In 
 this room should be a good cupboard, lighted and ventilated by a separate 
 window, so that certain articles of food may be kept in it without affecting, or 
 being affected by, the air of the room itself. The scullery adjoinmg the living 
 room should contain a copper with furnace, and sometimes also a bread oven, 
 likewise a sink, plate-rack, &c. Convenient minimum dimensions for this 
 room are 10 feet by 7 feet 6 inches. The pantry can be entered through the 
 scullery, but must have independent ventilation direct to the external air. On 
 no account should it be placed in an underground cellar, nor in the staircase 
 leading up from the cellar. It is important that the pantry should be open 
 to free ventilation, light, cool and dry, and, above all, well protected against 
 the rise of ground air. The fuel stove is best placed in a shed out of doors 
 —where also should be the necessary privy accommodation and place for 
 temporary deposit of dust and house refuse. The staircase should be so 
 arranged as to obviate the possibility of its serving also as an air-shaft 
 
THE DWELLING 
 
 677 
 
 Fig. 116. 
 
 up which the vitiated air from the hving room could ascend to the sleeping 
 apartments. This is most effectually secured when the hving room is 
 entered through an enclosed porch, which likewise gives access to the stairs, 
 as m fig. 121. The 
 provision of an adequate 
 porch has the further 
 advantage of affording 
 the entrance some pro- 
 tection from the wea- 
 ther, while it is always 
 useful to the occupier 
 as a place for removal 
 of outer clothing, boots, 
 &c., in wet weather in- 
 stead of taking them 
 direct into the living 
 room. The bedrooms 
 ought to be as large 
 as the circumstances 
 permit, that for the 
 parents being about 12 
 feet by 10 feet and pro- 
 vided with a fireplace 
 and good cupboard, and 
 the children's rooms 
 having a floor area of 
 about 80 square feet 
 and 60 square feet re- 
 spectively ; and it is 
 very desirable that 
 these rooms should 
 have fireplaces in them. 
 
 Approximately the 
 same accommodation 
 as last above described 
 may be obtained in a 
 one-storey cottage ar- 
 ranged upon either of the 
 plans (figs. 116 to 120). 
 
 The artizan's dwel- 
 ling involves greater dif- 
 ficulty of arrangement 
 upon a convenient, ade- 
 quate, and wholesome 
 plan than the agri- 
 cultural labourer's cot- 
 tage, since it is usually 
 necessary to place it 
 on a site where land 
 itself is of much greater 
 value than agricultural 
 land. It has to be in the immediate vicinity of some factory, where con- 
 siderable numbers of persons are employed, and therefore, if not actuaUy in 
 a town, it must be in at least a populous district. Hence, the necessity for 
 
678 
 
 HYGIENE 
 
 Fig. 119. 
 
 crowding the dwellings together ; and so great is this necessity that, not 
 only are the dwellings often arranged in rows with streets of the minimum 
 width permissible in the locaHty in front of them, and with the smallest per- 
 missible amount of open space at the rear of them, but in many towns and 
 
 in the metropolis, where 
 the cheapest land is 
 very costly for the pur- 
 pose, the houses have 
 to be piled up in blocks 
 of building many storeys 
 in height. The separate 
 house of the artizan 
 usually built in rows in 
 the suburbs of the busy 
 manufacturing towns 
 (lifters but little, as re- 
 gards accommodation, 
 from the dwelling of 
 the country labourer 
 with a family, but the 
 modern block of artizans ' 
 dwellings that has de- 
 veloped in the last fifty 
 years involves some 
 important hygienic 
 
 questions that can 
 scarcely be said to 
 apply in the case of 
 separate dwellings. 
 
 This type of buildmg 
 has undergone much 
 change, and many hy- 
 gienic improvements 
 have been made in the 
 more recently erected 
 blocks of dwellings. 
 
 In what is probably 
 the first published plan 
 for such a building, de- 
 signed, in 1841, by Mr. 
 Sydney Smirke,' a num- 
 ber of separate dwel- 
 lings consisting of one, 
 two, or more rooms 
 each, are arranged 
 along both sides of a 
 main corridor eight feet 
 Avide in each storey of 
 a three-storey building 
 T)lannea in the form of the letter E. A similar arrangement of dwellings 
 alonc^ both sides of a corridor was adopted in some of the earlier blocks 
 of building erected by the trustees of the Peabody Fund. This plan, however, 
 ' Report hy the Poor-law Commissioners on the Sanitary Condition of the Labour- 
 i>ig Population of Great Britain, p. 274. Prepared by Edwin Chad^Yick. London : 1842. 
 
 Fig. 12a 
 
 Fig. 121. 
 
THE DWELLING 
 
 679 
 
 Fig. 122. 
 
 has now been discarded owing partly to the dishke evinced by the inhabitants 
 of the dwelhngs to the absence of privacy and independence that was inevitable 
 under the corridor arrangement, and partly to hygienic objections. As regards 
 the latter, the corridor 
 always involves much 
 difficulty in regard to 
 light and ventilation ; 
 it interferes with the 
 through -ventilation of 
 the dwellings along its 
 sides ; it leads to the 
 enclosed atmosphere of 
 the whole building 
 being uniformly vitiated 
 by the aggregation of 
 a large population, and 
 in the event of any in- 
 fectious disease occur- 
 ring among the inhabi- 
 tants of one dwelling, 
 the risk of its spread- 
 ing, by means of the cor- 
 ridor and staircases, to 
 the inmates of the other 
 
 ' dwelhngs in the same 
 building is very con- 
 siderable. A further de- 
 fect in the earlier blocks 
 
 ' of dwellings was the pro- 
 vision of a water-closet 
 as an integral part of each 
 dwelling, and arranged 
 
 in such relationship to 
 the rooms as to be 
 
 more or less a source of 
 
 danger to health. The 
 
 > disposition of the blocks 
 
 •on the site available for 
 
 them was a further 
 
 point upon which many 
 
 errors have been made, 
 
 for in some instances 
 
 the blocks, many storeys 
 
 high, have been directly 
 
 connected together at a 
 
 right angle, and even 
 
 at an acute angle, so 
 
 as to seriously interfere 
 
 with the free circula- 
 tion of air about the 
 
 exterior and the access 
 
 of light to many of the rooms. In some instances the buildings have been 
 
 arranged continuously round a central courtyard with a mere archway, one or 
 
 two storeys high, in one side to give access thereto. These grave defects, 
 
 p U-l t-» ' M l-l 
 
 30 Feet 
 
 Fig. 123. 
 
 i-i t_i i-j i-_i i_j 
 
 30feef 
 
 Fig. 124. 
 
680 HYGIENE 
 
 which have been found prejudicial to the health of the inhabitants, and to 
 increase the death-rate, especially the infant mortality, have been generally 
 much diminished in the more recently erected blocks of dwellings. The cor- 
 ridors have been dispensed with, and each dwelling is now usually independent 
 of the others, so far as enclosed atmosphere common to all is concerned ; for 
 the staircases are generally arranged to give access to one vertical series of 
 dwellings only on each side of them, and are entirely open to the external 
 air. The water-closet accommodation to each dwellmg is often arranged 
 so as to be accessible from the external air by means of some sort of 
 balcony ; and the blocks of building are often wholly detached, thus doing 
 away with confined angles and stagnant corners. These improved arrange- 
 ments, however, are not invariably adopted, and unless some controlling 
 authority is invested with power to require them, and to see them carried 
 out, it seems probable that the natural desire to provide numerous cheap 
 dweUings, at the smallest possible outlay, will induce many speculating builders 
 and others to still erect huge blocks of dwellings, piled up storey upon storey,, 
 regardless of light and air, and producing an excessive aggregation of human 
 beings under the one roof and an undue density of population on area. This 
 has already been referred to ; hence it is only necessary here to point out the 
 extreme necessity for insisting upon ample open space between the blocks of 
 these dwellings, and the complete disconnection of the blocks one from 
 another, in order to avoid all confined angles and to ensure the utmost 
 freedom of circulation of air about the blocks, and of access of light with a 
 certain amount of such sunshine as is available in our climate to every room 
 intended for habitation durmg a portion of the day. If these conditions 
 are insisted upon, culs-de-sac will in effect be prohibited, and the height of 
 the blocks on the one hand, and the distances between them and adjacent 
 buildings or blocks on the other, will have to bear some relation the one 
 to the other. 
 
 Much credit is often assumed by certain managers and directors of existing 
 dwellings of the kind referred to for the moderate death-rate and rate of infant 
 mortality in the dwellings, and it is sought to illustrate the excellence of the 
 health arrangements of the respective blocks of dwellings by a comparison with 
 the rates of mortality of the metropolis as a whole. But it has to be borne in 
 mind that the occupiers of these blocks of dwellings are, to a very large extent, 
 a population specially selected for their respectability and other good qualities. 
 It is generally admitted that these inhabitants are ahvays socially far above the 
 class of inhabitants of the insanitary dwellings that were pulled down to 
 make way for the improved dwellings, that the landlords of these new dwellings 
 naturally drift into the groove followed by all landlords and get rid of the 
 worst tenants, and thus the inhabitants of these dwellings come to be a picked 
 set of highly respectable families. With all this in favour of the health condi- 
 tions of the population of these dwellings, the difference between the mortality 
 rate in them and in the whole metropoHs is often but very little, especially 
 in regard to the rate of infant mortality. Thus it is stated, for example, that 
 in a population of between 6,000 and 7,000, occupying upwards of a dozen 
 different estates of such dwellings — though there was room for more, many 
 of the dwellings being empty — the general death-rate was only 15'6per 1,000, 
 while in the whole metropolis it was 18" 5 ; but in these same dwellings the 
 rate of infant mortality was 140 per 1,000 births, or only six less than in the 
 whole metropolis, where the rate during the same period was 146 per 1,000 
 births. This difference in so important a matter as infant mortality seems 
 much smaller than should be regarded as completely satisfactory. 
 
 There are many points about the dwellings of the artizan and labouring 
 
THE DWELLING 681 
 
 classes which, even where they have been erected otherwise than by mere 
 speculators, call for special attention and improvement. The customs of 
 the people and the character of the locality, moreover, often exercise a certain 
 influence upon the hygienic arrangements, for whereas in southern towns of 
 England water-closets are almost universal in dwellings of the class under 
 consideration, similar dwellings in the midlands and in the northern counties 
 are frequently provided with some sort of privy or dry system of closet. It is 
 not at all uncommon, too, in the latter districts to find the amount of closet 
 or privy accommodation in much smaller proportion than in the south, and 
 such as is provided is often arranged in what would be regarded in the more 
 southerly districts as very inconvenient positions relatively to the houses for 
 which they are intended. The Public Health Act, 1875, in Sec. 35 prohibits 
 the erection of any house ' without a sufficient water-closet, earth-closet, or 
 privy.' But Sec. 36 gives the local authority certain discretion in regard to 
 their judgment of the sufficiency of closet accommodation where a closet or 
 privy has been, is, or may be used in common by the inmates of two or more 
 houses, and accordingly houses for the artizan and labouring classes are 
 sometimes erected, even under the authority of town councils and other 
 local sanitary authorities, which have only one closet to every two, three, 
 and sometimes even four houses, the closets thus provided being placed in 
 groups in one yard common to all the houses in which the children play, the 
 women hang out their linen to dry after washing, and the men and boys 
 loiter about. The objections to these arrangements, quite apart from the 
 question of decency and morals, are serious from a hygienic point of view. 
 Thus the distance of the closet from some of the houses it serves is some- 
 times excessive — thirty or forty yards — and in some instances so placed that 
 the occupiers of certain houses must come out of their front door, pass along 
 the street to a passage leading through the row of houses to the privies in 
 the common yard at the rear. It will be obvious that such an arrangement 
 must tend to deter the inhabitants from using the closets as freely as might be 
 desired, while it certainly leads to the very objectionable practice of retaining 
 excreta in the houses until a convenient opportunity for carrying them to 
 the privies.^ The arrangement is further objectionable on sanitary grounds, 
 since it involves the use by the inhabitants of two or three different houses 
 of one privy in common, and since this privy discharges into the same 
 receptacle as do other privies which are resorted to by the inhabitants of 
 other houses. Under such circumstances infectious disease occurring in 
 any one of these houses might possibly be communicated to the inhabitants 
 of the other houses through the medium of these privies and ashpits. 
 
 Another grave defect that exists in many cottage dwellings in certain 
 
 ' Mr. Butterfield, formerly Medical Officer of Health for Bradford (Yorks), reports that 
 during an epidemic of summer diarrhoea which prevailed in that town in 1878 certain 
 houses in which deaths had occurred were visited, when it was found that the houses 
 fronting the street had suffered far more from the disease than those next the backyard, 
 in which were situated the privies and ashpits. Mr. Butterfield goes on to say : ' Why 
 the deaths should be twice as numerous in the front houses than in the back ones, which 
 face the privies and ashpits common to both, is not easily accounted for unless the more 
 ready access to the conveniences induces a more frequent and prompt removal of the 
 excreta than is the case in the front houses. I have frequently remarked that, rather than 
 pass through the portions of street and passage necessary to reach the proper receptacle, 
 women will conceal excreta in some obscure corner of the premises until nightfall. The 
 effect of thus contaminating the already sufficiently close atmosphere of a back-to-back 
 house is of course exceedingly prejudicial to a child suffering from the effects of bad nursing 
 and improper diet. More especially is this the case when the obscure corner before 
 mentioned is beneath the shelf on which the milk is kept.' 
 
G82 HYGIENE 
 
 districts where the land is of a very hilly character is that of erecting 
 on the side of a hill rows of cottages one row directly over the other, the 
 dwellings in the upper row fronting the rise of the hill in one direction and 
 those in the lower row fronting the descent of the hill in the reverse direction, 
 with the result that while the houses in the upper row have at their rear 
 ample air space, though no yards, the houses in the lower row have neither 
 air space nor yard at their rear, which generally abuts against the earth 
 beneath the street or roadway in front of the upper row of houses, and con- 
 sequently the lower ones are not only unprovided with any effectual means 
 of through-ventilation, but are necessarily dark and damp. Such houses, 
 new as well as old, are to be met with in numbers of towns in the hilly 
 districts of South Wales, Yorkshire, and elscAvhere. 
 
 For many years past the system of back-to-back house construction has 
 been condemned as being inconsistent with proper hygienic conditions, but it 
 is curious to notice how scanty were the actual reasons upon which this 
 general condemnation was based. True, the prevalence and intensity of 
 sickness in any town where this class of house was at all common were found 
 to be frequently greater in the locality where such houses were most 
 numerous than in other parts of the same town, but then the condition of 
 the surroundings of those houses as well as of the inhabitants themselves 
 was generally sufficient to account in a great measure for the excess of sick- 
 ness among them. This defective condition of surroundings was no doubt 
 largely due to bad local administration consequent on the then existing rudi- 
 mentary knowledge of sanitary requirements, upon the absence of efficient 
 laws for the prevention of overcrowding, upon defective systems of drainage, 
 or possibly the total absence of drainage, and upon the unlimited amount of 
 the most repulsive filth and refuse in various stages of putrefaction that was 
 commonly allowed to accumulate within, or in close vicinity of, the dwelling, 
 thus loaduig the air at all times and under all circumstances with offensive 
 and mischievous effluvia. 
 
 Such were the conditions that formerly existed in numbers of towns, 
 particularly in the north of England, where this class of dwelling was 
 prevalent ; and under such conditions it followed that the habits of the 
 occupiers of such houses only too frequently from their slovenliness made 
 the interior a counterpart of the exterior. Great improvements in the 
 sanitary administration of towns have taken place in recent years, and the 
 beneficial results therefrom may readily be perceived and are generally freely 
 admitted, but the actual sanitary disadvantages of the system of back-to-back 
 house construction j;er se, while still generally admitted, have not hitherto 
 received that searching investigation which the subject deserves and which 
 is requisite in order to demonstrate the serious prejudicial effect which it is, 
 with good reason, believed to have upon the occupiers of such houses and 
 the district in which those houses are built. That the question deserves 
 •serious attention can hardly be denied when its magnitude is taken into 
 :account. In many towns this vicious system of house construction is 
 permitted under local Acts of Parliament ; in others it is allowed under 
 some obsolete series of building bye-laws ; and even in the metropolis, 
 where unfortunately there is but little legislation for the sanitary control of 
 new buildings, it is not prohibited, directly or indirectly, either by Act of 
 Parliament or by bye-laws. Under these circumstances, and seeing that the 
 construction of back-to-back houses tends to the crowding of houses on 
 area, thereby in one sense enhancing the value of building land, it is not 
 surprising to find that the system, in one form or another, has been and is 
 still extensively adopted in many places ; and not only so, but in neighbouring 
 
THE DWELLING G83 
 
 newly developed localities the sanitary authorities are often desirous of adopt- 
 ing the same mode of house construction in order either to conform to what 
 is regarded as a local custom, or that house accommodation may be provided 
 for the wage-earning classes upon the same basis of expenditure and under 
 similar conditions as is provided in the older adjacent district. From 
 statistics published in a recent Government report ' upon the subject it 
 appears that in the borough of Halifax, where the erection of back-to-back 
 houses is still permitted and controlled by a local Act of Parliament, there 
 were 2,094 dwelling-houses of all kinds erected during the eleven years 187G- 
 86, and of these no less than 1,287, or 61 per cent., were back-to-back houses. 
 In Leeds, again, where a local Act permits and regulates the construction 
 of back-to-back houses, the same statistics show that during the two years 
 ending August 1887, out of a total of 2,311 new dwelling houses of all classes 
 that were certified as fit for habitation, no less than 1,502, or 65 per cent., 
 were of the back-to-back type, and it is estimated that house accommodation 
 of this type had been erected in the municipal district of Leeds during the 
 twelve years ending August 1887 for the large number of 50,000 persons. 
 In Bradford, where the erection of back-to-back houses is likewise allowed 
 and governed by a local Act of Parliament, in the eleven years 1876-86 out 
 of a total of 7,036 new houses, 4,486, or 64 per cent., were built on the back- 
 to-back system — equal to new house accommodation for a population of some 
 20,000 persons. 
 
 In the metropolis it is difiicult to arrive at any precise statistics of what 
 is being done in the way of erecting dwellings unprovided with means of 
 through-ventilation, but the various Acts of Parliament which control the 
 erection of buildings in the London district contain no provisions whatever 
 that would have the effect of wholly prohibiting the erection of back-to-back 
 houses. The Metropolitan Building Act, 1855, provides, in Sec. 29, that 
 every dwelling house, * unless all the rooms can be lighted and ventilated 
 from a street or alley adjoining,' shall have in the rear or on the side thereof 
 an open space exclusively belonging thereto to the extent at least of 100 
 square feet ; and this requirement is supplemented by the requirements of 
 Sec. 14 of the Amendment Act, 1882 (45 Vict. cap. 14), which enacts that every 
 new building to be erected on a site not previously occupied in whole or in 
 part by a building, and intended to be used as a dwelling house, shall, unless 
 the Metropolitan Board of "Works (now the London County Council) other- 
 wise permit, have directly attached to it in the rear an open space exclusively 
 belonging to it of an extent varying according to the length of its frontage. 
 Thus if the frontage do not exceed 15 feet in length, an area of at least 150 
 square feet is to be provided ; if the frontage do not exceed 20 feet in length, 
 the extent of the open space at the rear is to be at least 200 square feet ; for 
 30 feet frontage, 300 square feet ; and for more than 30 feet frontage, the extent 
 • of open space is to be at least 450 square feet. The clause likewise provides 
 that the open space shall extend throughout the entire width of the building, 
 -but allows the site to be entirely covered by building in the ground storey. 
 
 That these provisions are utterly inadequate to meet the requirements of 
 the present day as regards open space at the rear of dwellings as an indispen- 
 sable condition to the efficient through-ventilation of such buildings is shown 
 by the fact that numbers of dwellings are continually being erected with in- 
 sufficient open space at their rear or with no open space at all. The short pro- 
 visions on the subject in the Act of 1855 were admittedly inadequate, as an 
 extension of those provisions was included in the Amendment Act of 1882 ; 
 
 ' Joint Report to the Local Government Board of Dr. F. W. Barry and Mr. P. Gordon 
 -Smith on Back-to-Bach Houses. London : Eyre & Spottiswoode, 1888. 
 
G84 HYGIENE 
 
 but those extensions are so framed as to be of little real use, as they are map- 
 plicable except in the outskirts of the metropolitan area, where alone building- 
 sites ' not previously built upon ' are to be found ; and even these extensions, 
 which may be waived at the discretion of the controlling authority, permit 
 of the erection of a building with a basement storey likely to be used as offices 
 or for habitation to which no direct light could have access, and air could 
 only be got by means of shafts and the like, while the open space at rear 
 would be entirely above the level of the ceiling of the ground storey. The 
 requisite amount of open space, moreover, is to be calculated according to the 
 length of frontage instead of, as it ought to be, according to the height of 
 the building. For all practical purposes, the requirement of the Building 
 Act, 1855, is the only one applicable to London proper, and accordingly 
 dwellings of such shallow depth that all the rooms in them can have windows 
 in front are to be found which have been erected in quite recent years, and 
 which present the cardinal defects of houses of the back-to-back type. 
 
 What the effect upon the health of the occupiers of these dwellings 
 will be remains yet to be ascertained, but, so far as has at present been 
 observed, there is little doubt as to the prejudicial effect. From the 
 mortality tables prepared by Dr. John Tatham, formerly Medical Officer of 
 Health of Salford, and now of Manchester, it has been found that in certain 
 streets and courts consisting of back-to-back houses, unfurnished with through- 
 ventilation, tubercular disease was much more common than in other parts 
 of the same town, and such disease occurred again and again in the same 
 houses. From the same mortality tables it is shown in the Government 
 report already alluded to that the rate of mortality from epidemic diseases, 
 from phthisis, from pulmonary diseases other than phthisis, from other 
 diseases, and from diarrho-a respectively, increased in proportion to the 
 number of back-to-back houses in each of the district areas referred to, com- 
 prising the whole of the borough of Salford ; and although it is possible that, 
 in the consideration of such statement, a number of other factors ought to 
 be taken into account - such as relative density of population in the districts, 
 social status of the inhabitants, ages at death, &c. — still the fact of the 
 progressive increase in the death-rates from the several diseases mentioned 
 is extremely suggestive of the greater unhealthiness of the dwellings having 
 no through-ventilation. With the information at present available on the 
 subject, therefore, it is not surprising to find that the department of Govern- 
 ment concerned with the matter refuses to confirm bye-laws having for their 
 object the regulation of the construction of dwellings unprovided with 
 adequate means of through-ventilation ; and, so far as can at present be 
 judged, it seems unfortunate, in the interests of health, that those towns and 
 districts which already possess the power of regulating such a vicious plan 
 of house construction — whether under an old code of bye-laws which would 
 now be considered obsolete or under any local Act of Parliament — should 
 take no steps for securing other regulations more in conformity with modern 
 views of the subject. It is worthy of note in connection with this part of 
 the subject that in the First Eeport (1885) of the Royal Commission on the 
 Housing of the Working Classes it is recommended that in the rear of every 
 new dwelling house or other building to be controlled by rules ordinarily 
 applicable to dwelling-houses, and whether in old or in new streets, there be 
 provided a proportionate extent of space exclusively belonging to the dwelling- 
 bouse or building ; that this space be free from erections from the ground 
 level upwards ; that it extend laterally throughout the entire width of the 
 dwelling-house or building ; that for the distance across the space from the 
 building to the boundary of adjoining premises a minimum be prescribed ;. 
 
THE DWELLING G85 
 
 and that this minimum increase with the height of the dwelling house or 
 building. The Commissioners, in making these recommendations, recognise 
 the difficulty experienced in providing such open space in the case of towns 
 and districts already laid out, where the value of land has attained consider- 
 able magnitude ; and they state that the recommendations referred to must 
 be subject to the limitations which would probably be found necessary to pre- 
 vent undue sacrifice of property in individual cases or in particular areas. 
 
 The common lodging-house, regarded from a hygienic point of view, may 
 play an important part in the health conditions of a locality, and for this 
 reason it has been found necessary to provide special means of regulating the 
 conduct of such houses. This is the more necessary seeing that common 
 lodging-houses, according to the ordinary acceptation of the term, are not 
 generally built expressly for the purpose, but are more often, if not always, 
 houses of large size which have ceased to be adapted to the altered circum- 
 stances of the locality in which they were erected, and are taken over by some 
 small capitalist who farms them out or manages thern by ' deputy,' and thus 
 often turns them to fairly lucrative account. This class of house, however, 
 ■cannot be regarded with entire satisfaction, firstly, because such houses are 
 largely resorted to by the ' ne'er-do-well ' class ; and secondly, because in 
 those common lodging-houses where accommodation is provided for mar- 
 ried couples there is reason to believe that the majority of the men and 
 women, in representing themselves as married, make a false statement. 
 The Public Health Act, 1875, contains some very necessary and useful 
 provisions for the control of common lodging-houses with the view of 
 diminishing as much as possible the objections to them and of rendering 
 them harmless to health. Thus Section 80 of that Act enacts that ' every 
 local authority shall from time to time make bye-laws (1) for fixing and from 
 time to time varying the number of lodgers who may be received into a com- 
 mon lodging-house, and for the separation of the sexes therein ; and (2) for 
 promoting cleanliness and ventilation in such houses ; and (3) for the giving 
 of notices and the taking precautions in the case of any infectious disease ; 
 and (4) generally, for the well ordering of such houses.' If such bye-laws are 
 made and duly enforced it is clear that much will be done to render the 
 common lodging-houses as wholesome and satisfactory as could be expected. 
 
 Some uncertainty is supposed to exist as to what houses are to be included 
 in the term ' common lodging-house,' since the Public Health Act, 1875, con- 
 tains no precise definition of the term. It states, in Section 89, that the 
 expression ' common lodging-house ' includes in any case in which only part 
 of a house is used as a common lodging-house the part so used of such house ; 
 but this is far from indicating what the term itself generally include?* The 
 question has from time to time formed the subject of consideration by the 
 law officers of the Crown ; for as far back as 1853 the General Board of 
 Health, in a circular dated October 17 of that year, communicated to the 
 several local boards the opinion of the law officers of that day as to the 
 meaning of the term ' common lodging-house ' in the 14 and 15 Vict. cap. 28. 
 Those officers stated as follows :— 
 
 ' It may be difficult to give a precise definition of the term " common 
 lodging-house," but looking to the preamble and general pro^dsions of the 
 Act, it appears to us to have reference to that class of lodging-houses in 
 which persons of the poorer class are received for short periods, and though 
 strangers to one another are allowed to inhabit one common room. We 
 are of opinion that it does not include hotels, inns, public-houses, or lodgings 
 let to the upper and middle classes.' 
 
 By that part of the above definition which refers to the persons 
 
686 HYGIENE 
 
 inhabiting a common lodging-house being ' strangers to one another,' 
 the law officers in a second opinion explained that their ' obvious intention 
 was to distinguish lodgers promiscuously brought together from members 
 of one family or household.' 
 
 In reply to the question whether lodging-houses otherwise coming witliin 
 the definition, but let for a week or longer period, would, from the latter 
 circumstance, be excluded from the operation of the Act, the law officers 
 observed : ' We are of opinion that the period of letting is unimportant in 
 determining whether a lodging-house comes under the Act now in question.' 
 
 Since the- date of those expressions of opinion one or two judicial decisions 
 have been given as to what constitutes a common lodging-house. One of 
 these is specially deserving attention, as it points to the conclusion that in 
 deciding whether a given house is or is not a common lodging-house within 
 the meaning of the Public Health Act, 1875, regard should in each case be 
 had to the consideration whether the circumstances of its occupation are or 
 are not such that supervision by the local authority will be necessary in 
 order to secure the needed cleanliness, ventilation, good ordering, &c. For 
 the purpose of further facilitating the supervision of common lodging- 
 houses, Sees. 76 to 79 of the Public Health Act, 1875, impose on every 
 sanitary authority the duty of keeping a register of the common lodging- 
 houses in their district, and deal with other matters relating to the regis- 
 tration of them ; Sec. 78 provides that a house shall not be registered as 
 a common lodging-house until it has been inspected and approved for the 
 purpose by some officer of the local authority, and to this inspection too 
 much importance can hardly be attached, since it is essential that in all 
 structural details the fitness of the premises should be carefully ascertained 
 before the house is placed on the register. The Local Government Board, in 
 their official memorandum accompanying their model bye-laws with respect 
 to common lodging-houses, suggest the following rules for the guidance 
 of the inspecting officer in his examination of any premises that it may be 
 proposed to place on the register :— 
 
 The house should (1) possess the conditions of wholesomeness needed for dwelling- 
 houses in general ; and (2) it should further have arrangements fitting it for its special 
 purpose of receiving a given number of lodgers. 
 
 (1) The house should be dry in its foundations and have proper drainage, guttering, 
 and spouting, with properly laid and substantial paving to any area or yard abutting 
 on it. Its drains should have their connections properly made, and they should be 
 trapped, where necessary, and adequately ventilated. Except the soil pipe from a properly 
 trapped water-closet, there should be no direct communication of the drains with the 
 interior of the house. All waste pipes from sinks, basins, and cisterns should discharge 
 in the open air over gullies outside the house. The soil pipe should always be efficiently 
 ventilated. The closets or privies and the refuse receptacles of the house should be in 
 proper situations, of proper construction, and adapted to any scavenging arrangements 
 that may be in force in the district. The house should have a water supply of good 
 quality, and if the water be stored in cisterns they should be conveniently placed and of 
 proper construction to prevent any fouling of water. The walls, roof, and floors of the 
 house should be in good repair. Inside walls should not be papered. The rooms and stair- 
 cases should possess the means of complete ventilation ; windows being of adequate size, 
 able to be opened to their full extent, or, if sash windows, both at top and bottom. Any 
 room proposed for registration that has not a chimney should be furnished with a special 
 ventilating opening or shaft, but a room not having a window to the outer air, even if it 
 have special means of ventilation, can seldom be proper for registration. 
 
 (2) The numbers for which the house and each sleeping room may be registered will 
 depend partly upon the dimensions of the rooms and their facilities for ventilation and 
 partly upon the amount of accommodation of other kinds. In rooms of ordinary construc- 
 tion to be used for sleeping, where there are the usual means of ventilation by windows 
 and chimneys, about 300 cubic feet will be a proper standard of space to secure to each 
 
THE DWELLING- 687 
 
 person ; but in many rooms it will be right to appoint a larger space, and this can only be 
 determined on inspection of the particular room. The house should possess kitchen and 
 dayroom accommodation apart from its bedrooms, and the sufficiency of this will have to 
 be attended to. Kooms that are partially underground may not be improper for dayrooms, 
 but should not be registered for use as bedrooms. The amount of water supply, closet or 
 privy accommodation, and the provision of refuse receptacles should be proportionate to 
 the numbers for which the house is to be registered. If the water is not supplied from 
 works with constant service, a quantity should be secured for daily use on a scale, per 
 registered inmate, of not less than ten gallons a day where there are water-closets, or five 
 gallons a day where there are dry closets. For every twenty registered lodgers a separate 
 closet or privy should be required. The washing accommodation should, wherever practi- 
 cable, be in a special place and not be in the bedrooms ; and the basins for personal 
 washing should be fixed and have water taps and discharge pipes connected with them. 
 
 With reference to the amount of cubic space (300 feet) above mentioned 
 as a proper standard to secure to each person in rooms of ordinary construc- 
 tion, there must be frequent instances where a larger amount is necessary 
 — indeed, it is obviously impossible to lay down a hard-and-fast rule,, 
 since the requisite quantity of space must depend upon a variety of con- 
 siderations. In the metropolis the Commissioner of Police has a minimum 
 standard, which is determined in part by the height of the room, and gives 
 about 300 cubic feet to each person in rooms only used for sleeping, and which 
 are unoccupied during the day, inspection being also provided for the purpose 
 of ascertaining that ventilation is efficiently maintained. This amount has 
 been decided upon in view of the difficulties of lodgment in the metropolis, 
 and ought certainly not to be diminished. When a room is occupied both 
 by night and by day at least 400 cubic feet ought to be obtained for each 
 inmate, and this only on the assumption that ample means of ventilation by 
 open fireplace and windows (to open) are also provided. Where children 
 come into consideration, it is common to reckon two children under ten years 
 of age as one person, but this appears to be an unfortunate arrangement, since 
 it is desirable that a child who is growing and developing should have at 
 least as much air space as an adult. 
 
 As regards other detail arrangements bearing upon health in connection 
 with common lodging-houses over and above those already referred to, it may 
 be useful here to point out that the model bye-laws of the Local Government 
 Board ^ contain many recommendations on the subject. One of these relates 
 to the arrangement of the sleeping accommodation to be provided for married 
 couples where two or more such couples occupy the same room, and prescribes 
 that each bed shall be effectually screened from any other bed by suitable 
 partitions. These partitions, which are indispensable in the interests of 
 privacy and decency, are usually required to be of wood or other sohd material^ 
 extending, not up to the ceiling, but to a height of about six feet six inches, 
 so as, while serving effectually to screen the bed, not to interfere unduly with 
 light and ventilation. They should likewise not extend down to the floor,, 
 but should stop short some six or eight inches above the floor in order to 
 admit of the free movement of air and to facilitate the cleansing of the whole 
 surface of the apartment. Curtains are sometimes proposed as screens, but 
 their use for the purpose should be avoided, as they are less cleanly than, 
 wood or sheet iron, either of which materials can be more conveniently painted 
 and washed. Moreover, as curtains can easily be either wholly or partially 
 withdrawn at the discretion of the lodgers, their use for the purpose of screen- 
 ing and separating the beds loses much value, and likewise renders it impos- 
 sible to throw the responsibility of maintaining an effectual screen upon the 
 
 ' Knight's Annotated Model Bye-laws of the Local Government Board, 2nd & 3rd 
 Editions. London : Knight & Co., 1885 and 1890. 
 
€88 HYGIENE 
 
 keeper of the house. Wooden partitions as screens round the bed of each 
 married couple have long been required in the metropolis by the Metropolitan 
 Police Commissioners. 
 
 Over and above what are known as common lodging-houses, there are 
 two other classes of lodgings that demand special attention, namely, ' cellar 
 dwellings ' and ' houses let in lodgings,' both of which are referred to in the 
 Public Health Act, 1875. As regards the former, Sees. 71 to 75 of that 
 Act deal very definitely with the character of such dwellings, but as regards 
 the latter, under Section 90 of the Act, the control of such houses is left far 
 more in the hands of the local sanitary authority, since they may be empowered 
 to make bye-laws for dealing with such houses with the view of enforcing 
 such sanitary requirements as may be necessary in addition to the numerous 
 enactments of the Public Health and other general statutes which may bear 
 upon houses of this description. 
 
 As regards cellar dwellings, it is unfortunate from a health point of view 
 that apartments of the kind should be allowed to be occupied as dwellings at 
 all. The 71st section of the Public Health Act, 1875, prohibits the letting 
 or occupation separately as a dwelling of any cellar built or rebuilt after the 
 passing of that Act, and the next section specially prescribes certain requisitions 
 that must be complied with in regard to any cellar dwelling whatsoever. 
 Amongst these requisitions it is laid down that the cellar must in every part 
 be at least seven feet high, three feet of which must be above the surface of 
 the street adjoining ; also that a continuous external open area two feet six 
 inches wide be provided along the frontage of the cellar, the floor of which 
 must be six inches below the level of the floor of the cellar ; likewise that 
 the cellar must be effectually drained by means of a drain, the uppermost 
 part of which is one foot at least below the level of the floor of the cellar ; 
 and further that there be appurtenant to the cellar the use of a water-closet, 
 earth-closet, or privy, and an ashpit, &c., and that the cellar have a fireplace 
 and an external window of at least nine superficial feet, to open in an approved 
 manner, except in the case of an inner or back cellar let or occupied along 
 with a front cellar as part of the same letting or occupation, in which case 
 the external window may be of any dimensions not being less than four 
 superficial feet in area clear of the sash frame. It will scarcely be alleged 
 that these conditions of letting or occupying cellar dwellings, judged merely 
 upon their hygienic merits, are otherwise than extremely moderate, but they 
 are nevertheless frequently infringed. In view of the steps that have been 
 taken in recent years, however, to provide improved dwellings for the poorer 
 classes, it would seem probable that at some not very remote period, if the 
 time has not already arrived, all necessity for permitting the use of cellars 
 as dwellings will cease, and that vast numbers of such dwellings which now 
 scarcely comply with the statutory requisitions, and which can never be made 
 wholesome, will no longer be allowed to be occupied. In the metropolis the 
 requirements as regards cellar dwellings have hitherto been slightly different 
 from those prescribed for the rest of the country under the Public Health 
 Act, 1875 ; but mider the Pubhc Health (London) Act, 1891— Sections 96 
 to 98 — the stringency of the requirements as regards underground rooms 
 (hitherto known as cellar dwellings ) has been greatly increased. 
 
 As regards houses let in lodgings, the Public Health Act authorises any 
 local sanitary authority, after certain preliminary formalities, to make bye- 
 laws upon the undermentioned matters, and under Section 94 of the Public 
 Health (London) Act, 1891, the sanitary authorities in the metropolis are 
 required to make and enforce such bye-laws as are requisite in regard to 
 those matters. 
 
THE DWELLING 689 
 
 (1) For fixing and from time to time varying the number of persons who may occupy 
 a house or part of a house which is let in lodgings or occupied by members of more than 
 one family, and for the separation of the sexes in a house so let or occupied : 
 
 (2) For the registration of houses so let or occupied : 
 
 (3) For the inspection of such houses : 
 
 (4) For enforcing drainage and the provision of privy accommodation for such houses, 
 and for promoting cleanliness and ventilation in such houses : 
 
 (5) For the cleansing and lime-washing at stated times of the premises, and for the 
 paving of the courts and courtyards thereof : 
 
 (6) For the giving of notices and the taking of precautions in case of any infectious 
 disease. 
 
 And the Local Government Board, with the view to assist local authorities, 
 have issued a series of model bye-laws bearing to a certain extent upon the 
 several matters referred to. They have suggested the exemption from the 
 operation of the bye-laws of certain houses which, though let in lodgings or 
 occupied by members of more than one family, are of such a character as to 
 render it inexpedient, if not absolutely unnecessary, to bring them within the 
 range of bye-laws having for their primary object the regulation of premises 
 where neglect of sanitary requirements might otherwise ensue, and accordingly 
 a clause is inserted in the model series which provides for the exemption of 
 lodging-houses as to which it may be reasonably inferred that the supervision 
 by the sanitary authority which under other circumstances would be neces- 
 sary will be sufficiently exercised by the lodgers themselves. The model 
 bye-laws ignore the question of the separation of the sexes as to which the 
 statute authorises the making of bye-laws, but proceed to suggest a few simple 
 rules whereby the number of persons to occupy the several sleeping rooms 
 may be determined with reference to the amount of free air space contained 
 in the rooms. It is suggested that in every room used exclusively as a sleep- 
 ing apartment a minimum allowance of 300 cubic feet of free air space should 
 be afforded to each person above ten years of age, and 150 cubic feet of space 
 to each child whose age does not exceed ten years. In the case of a room 
 not used exclusively as a sleeping apartment, these quantities of air space 
 are increased to 400 cubic feet and 200 cubic feet respectively. The other 
 suggested clauses in the model series relate to facilities for inspection ; to 
 the provision of adequate and suitable water-closet, earth-closet, or privy 
 accommodation, which is fixed at a rate of one such closet to every twelve 
 persons sleeping in the house ; and to the general maintenance of the 
 premises, and the several parts thereof, in a proper cleanly and habitable 
 condition, and the windows of the sleeping rooms to be regularly opened for 
 thoroughly airing the rooms ; and likewise as to the notification of any case 
 of infectious disease that may be known to have occurred in the house. 
 
 The sixth class, embracing dwellings of the institution type, has many 
 pecuharities which deserve special attention. Thus the object of each of 
 the several kinds of institution must be carefully considered in regard to the 
 particular hygienic conditions that are applicable to it ; for although some 
 of those conditions may be important as regards every type of dwellmg, they 
 may be more indispensable in one kind of institution than in another. This 
 will be better appreciated when it is borne in mind that a residential school, 
 in which children of tender age pass nearly the whole of their time, must be 
 so contrived as to comprise the best conditions for establishing the physical 
 health and moral training, as well as the education of the child, during the 
 eight or ten years or more when the constitution is forming, and the body is 
 growing and developing ; at a time when everything is requisite that conduces 
 to promote that strength of body and mind which is so important in fostering 
 ■courage and vigour, and tends to promote the higher quahties — honour, 
 
 VOL. I. Y Y 
 
690 HYGIENE 
 
 integrity, and truth. For it seems probable that untruthfuhiess is, in a 
 great measure, the outcome of fear and timidity, which in its turn is caused 
 by certain low conditions of vitality. The barrack must be adapted to 
 receive the adult man who comes to it in sound health to pass some of 
 the best years of his life, and the conditions must be such as will conduce 
 to the maintenance of his health and strength so long as he remains in 
 the service. Prisons, again, involve a variety of conditions according to 
 the age, duration, and class of sentence, and other circumstances connected 
 ^\ith the prisoners. The hospital must be so contrived as to facilitate the 
 cure and expedite the discharge of the patient who is brought to it, and 
 who ordinarily does not remain there more than a short period, rarely 
 exceeding a few weeks. The asylum, in so far as it has to deal with curable 
 cases, must occupy very much the same category as the hospital, but, 
 where it has to deal "with those whose age or condition renders the chance 
 of improvement or cure very remote or hopeless, would in many ways come 
 in the same category as the workhouse for aged and infirm, where all that- 
 could be expected would be ordinary care and attention, and such arrange- 
 ment of buildings as would tend to promote the comfort and to maintain the 
 general health conditions of the patients. The workhouse is more or less a 
 combination of residential buildings for the several classes of indoor poor who 
 come under the care of the Poor-law Guardians, for the rearing of childi'en 
 and litting them to become self- supporting when grown up, for the maintenance 
 of the able-bodied pauper in a healthy state with such employment as can 
 properly be exacted, for the proper care and maintenance of the aged, the 
 infirm, and the harmless imbecile, with reasonable comfort to themselves, 
 and for the care, nursing, and medical attendance of the sick. 
 
 In the arrangement of all these buildings vast changes have taken place 
 in recent years, as a result of increased knowledge of hygiene and of the im- 
 portant influence that improved conditions have upon the imnates of the 
 several classes of institution mider consideration. 
 
 PEISONS 
 
 In modern times the earhest substantial efforts at improvement in the 
 arrangement of these institutions are those which were initiated by John 
 Howard in regard to prisons and hospitals. His works upon the state of 
 those institutions, both British and foreign, are standing records of the 
 terrible conditions existing at the latter end of the last century. So far as 
 the prisons were concerned, Howard, who first had his attention drawn to 
 the subject when he was Sheriff of the County of Bedford, in 1773, was 
 struck not only with the shameful administration of the prisons under which 
 those confined, both debtors and felons, were subjected to aU kinds of ill-usages 
 and e\il practices at the hands of the gaolers and other officers, but also 
 with the general prevalence of what was known as the gaol fever, the gaol 
 distemper, and of small-pox in the prisons ; and these diseases carried off by 
 death a far larger number of prisoners who were confined for offences of 
 comparatively slight importance than the actual number of prisoners who 
 suffered execution according to the laws then m force. Writing of the state 
 of the atmosphere in some of the prisons visited, Howard says : ' My reader 
 will judge of its malignity when I assure him that my clothes were, in m} 
 first journeys so offensive, that in a postchaise I could not bear the 
 wmdows drawn up, and was therefore obhged to travel commonly on horse- 
 back. The leaves of my memorandum book were often so tainted that 1 
 could not use it till after spreading it an hour or two before the fire ; and 
 
THE DWELLING 
 
 691 
 
 even my antidote, a vial of vinegar, has, after using it in a few prisons, become 
 intolerably disagreeable.' 
 
 This horrible condition of the air of the prisons, together with other gross 
 defects such as insufficient water, bad food, bad drainage, and the like'^ not 
 only caused many prisoners to die, but a still larger proportion of them were 
 seriously crippled for Hfe. Howard says : ' Certain it is that many of those 
 who survive their long confinement are by it rendered incapable of working. 
 Some of them by scorbutic distempers, others by their toes mortified, or 
 quite rotted from their feet, many instances of which I have seen.' 
 
 _ Some of Howard's recommendations for obviating the defects of the old 
 prisons when a new one was to be erected were far in advance of his time. 
 He says : ' That part of the building which is detached from the (surrounding) 
 walls and contains the men-felons' ward may be square or rectangula'i% 
 
 Fig. 125.— The Bastille. 
 
 ^' ^ITr^''' ^J ^^^ fjf"^ °^ ^*- I'ltoi'ie ; B, Entrance and First Drawbridge ; c, Hotel du Gouverne- 
 ment ; D First Conrt ; b, Avenue leading to the Great Court ; p, Gates of the Great Court and 
 CoZc^l r1f>,W,h'p.°.°'?'p' ^^^f?.i^' K^"^"* ^T" ^^*^'° ^^^ T'owers ; i, Staircase leadTng to tSe 
 ii?i?f P /> ^^"^ '^''' ?°''''°'^ Chamber ; l, Cour du Puits ; M, Way to the Garden ; I, Steps 
 to the Garden; o Garden; p. Fosses; q, Passage to the Arseial Garden; 1, Tour du Pu^?- 
 2, Tour de la Liberty ; 3, Tour de la Bertaudifere ; 4, Tour de la Bazini^re • 5 Tour de la 
 Comt6; 6, Tour du Tr6sor ; 7, Tour de la Chapelle ; 8, Tour du Coin. ' ' 
 
 raised on arcades that it may be more airy ; ' and again, ' The infirmary or 
 sick- wards should be . . . raised on arcades.' This plan of raising the wards 
 on arcades or arches ' that they may be more airy ' is now not uncommonly 
 adopted in the case of new hospitals in France and Germany, as described 
 below under the head of Hospitals. In the days when Howard was engaged 
 m_ his inspection of prisons the numbers confined were but few compared 
 with the numbers to be found in the prisons of the present day; for formerly 
 large numbers were transported, and many were executed, and the large 
 majority of those detained in the gaols or prisons were mere debtors and 
 persons committed for petty offences. The prisons, moreover, were then very 
 numerous— far more numerous, compared with the population, than at the 
 present day. And yet, notwithstanding the small aggregation of prisoners 
 in those old prisons, serious disease was of most common occurrence. 
 
 tt2 
 
692 HYGIENE 
 
 It ■uill be interesting here to reproduce the plan of the Bastille at Paris 
 (fig. 125), with the description of some portions of it given by HoAvard, as 
 supplied to him in the form of a pamphlet published in France in 1774, but 
 immediately suppressed : — 
 
 ' The Castle is a State prison consisting of eight very strong towers, surrounded with a 
 /osse about one hundred and twenty feet wide, and a wall sixty feet high. The entrance 
 is at the end of the street of St. Antoine by a drawbridge, and great gates into the court 
 of VHuid du Gouvemctncnt ; and from thence over another drawbridge, to the Corps de 
 Garde, which is separated by a strong barrier constructed with beams plated with iron, 
 from the Great Court. This court is about 120 ft. by 80 ft. In it is a fountain, and six 
 of the towers surround it, which are united by walls of freestone 10 ft. thick up to the 
 top. At the bottom of this court is a large modern Cor2)s de Logis which separates it 
 from the Court du Pints. This court is 50 ft. by 25 ft. Contiguous to it are the other 
 two towers. On the top of the towers is a platform continued in terraces on which the 
 prisoners are sometimes permitted to walk attended by a guard. On this platform are 
 thirteen cannons mounted, which are discharged on days of rejoicing. In the Cor^M de 
 Logis is the council chamber, and the kitchen, offices, &c. ; above these are rooms for 
 prisoners of distinction, and over the council chamber the King's lieutenant resides. In 
 the Court du Fnifs is a large well for the use of the kitchen. The dungeons of the Tower 
 de la Liherti extend under the kitchen, etc. Near that tower is a small chapel on the 
 ground floor. In the wall of it are five niches or closets, in which prisoners are i^ut one 
 by one to hear mass, where they can neither see nor be seen. The dungeons at the bottom 
 of the towers exhale the most oiJensive scents, and are the receptacles of toads, rats, and 
 other kinds of vermin. In the corner of each is a camp bed made of planks laid on iron 
 bars that are fixed to the walls, and the prisoners are allowed some straw to lay on the 
 beds. These dens are dark, having no windows, but openings into the ditch ; they have 
 double doors, the inner ones plated with iron with large bolts and locks. Of the five 
 classes of chambers, the most horrid next to the dungeons are those in which are cages 
 of iron. There are three of them : they are formed of beams with strong plates of iron 
 and are each 8 ft. by 6 ft. The calottes, or chambers at the top of the towers, are somewhat 
 more tolerable. They are formed of eight arcades of freestone. Here one cannot walk 
 but in the middle of the room. There is hardly sufficient space for a bed from one arcade 
 to another. The windows, being in walls ten feet thick, and having iron gates within and 
 without, admit but little light. In these rooms the heat is excessive in summer and the cold 
 in winter. They have stoves. Almost all the other rooms (of the towers) are octagons 
 about 20 ft. in diameter and from 14 to 15 ft. high. They are very cold and damp.' 
 
 If any class of the community need more consideration in regard to 
 the hygiene of his dwelling than another, it assuredly is the inmate of our 
 prisons. He is compelled to occupy whatever accommodation the authorities 
 provide for him, and to endure whatever conditions they may determine. 
 Unlike the pauper, who when destitute may be compelled to resort to the 
 workhouse as a dwelling, he is not permitted to communicate with the out- 
 side world ; hence it is of the utmost importance that the health conditions 
 of our prisons should be, in all respects, the best. As a type of the modern 
 English prison, and in striking contrast to the old Bastille of Paris, and 
 even to Newgate or the Penitentiary of London, that recently erected for 
 convicts at Wormwood Scrubs, in the west of London, may be referred to. 
 Standing in a very open situation, abutting on a large tract of land that has 
 been made over to the public in perpetuity as a recreation ground, the prison, 
 together with the officers' quarters and various administrative buildings, 
 occupies a site some twenty acres in extent. The old-fashioned plan of 
 arranging the building containing the prisoners' cells in long blocks attached 
 to and radiating from a central inspection block, such as was adopted for, 
 among others, the Model Prison at Pentonville erected fifty years ago, has 
 very properly been abandoned, because the blocks so placed involved the 
 formation of narrow and confined yards between them, in which there was 
 absence of light, stagnation of air, and consequent damp and unwholesome 
 conditions generally. 
 
THE DWELLING 
 
 G93 
 
 The principle of arrangement adopted at the Wormwood Scrubs Prison 
 (fig. 126) is that now followed universally in the construction of every 
 large hospital, namely, what is known as the pavilion system. On this 
 princijple the whole number of ordinary cells are divided up into four dis- 
 tinct groups, making a total, apart from infirmary accommodation, of 1,378. 
 The four parallel pavihons or cell buildings are each four storeys high, the 
 two middle ones being 228 feet apart and the outer ones 2G2 feet distant from 
 them. There is thus ample space between them, not merely for free circu- 
 lation of air and the access of sunhght to both sides of the pavihons— their 
 aspect being east and west— but for exercise yards for the prisoners and for 
 sundry necessary administrative buildings such as kitchen ofiices, stores, 
 bakehouse, bathhouses with fifty-four baths for the male and twelve for the 
 
 ^'??i, ,?;,,,?., 
 
 Fig. 126. — Block Plan of Wormwood Scrubs Prison. 
 
 Cell Building, 327 cells ; B, CeU Building, 350 cells ; c. Cell Building, 350 cells ; D, Cell Building, 
 351 cells ; b, Baths ; P, Boiler House ; g, Bakery ; h, Bread and Flour Store ; mi. Chapel ; 
 I, Kitchen; J, Laundry; K, Females' Baths ; L, Eoman Catholic Chapel; M, Matron; n, Pho- 
 tographer ; o O, Offices ; p p, Beceptlon and Hospital ; Q, Clothes Store ; R, Coal Store ; s, Dead 
 House ; t. Warders' Mess ; V, Steward's and Manufacturer's Store ; v, Artificers' Shops ; W, 
 Entrance Building ; x. Officers' Reading Room ; Y, Warders' Quarters ; z, Governor's House ; 
 A A, Superior Officers' Quarters. 
 
 female prisoners, laundry building, &c. The cell buildings are each 48 ft. 
 wide from outside to outside, and each consists of a central hall or corridor 
 16 ft. wide, extending throughout its entire length, lighted from the ends and 
 roof, with iron galleries about 3 ft. wide at each of the upper floor levels, 
 giving access to a row of cells along each side. The cells are each 13 ft. deep, 
 7 ft. wide, and 9 ft. high to the highest part of the arched ceiling, and conse- 
 quently contain fully 800 cubic feet of space. They are each hghted by a 
 window about 3 ft. 6 in. wide by 2 ft. high, glazed with fluted glass, of which 
 about one-seventh is made to open as a hopper, by means of which a small 
 quantity of fresh air can be admitted at the discretion of the prisoner du'ect 
 from the outside; but as this is fully 7 ft. above the floor level of the cell, the 
 prisoner has no ready access to the opening except by a lever handle within 
 
694 
 
 HYGIENE 
 
 his reach. The constant ventilation of each cell is effected by a couple of 
 flues in the end walls : one of such flues brings into the cell a supply of fi'esh 
 air which can be warmed by heating apparatus and pipes beneath the main 
 gallery floor, and the other drawing ofl" the vitiated air into a trunk in the 
 roof leading to a turret in which an upcast current is induced by a fire con- 
 
 ROAD FROM NANTERRE TO .'iT. DEM.i. 
 Fig. 127.— Block Plan of Prison at Nanterre. 
 
 stantly burning. The outlet for vitiated air is a grating about 18 by 9 in. 
 into a flue in the external wall, about 12 in. above the floor level, and the 
 inlet for fresh air, warmed when necessary, is a similar grating into a flue in 
 the corridor wall about 7 ft. above the floor level. Artificial light is given 
 by a ventilated gas burner in the thickness (18 in.) of the corridor wall with 
 
THE DWELLING 695 
 
 a ground glass panel next the cell. Each cell is furnished with a couple of 
 shelves in one corner, a fixed table immediately beneath the gaslight, a stool 
 seat, a movable plank-bed which is stood up on end during the day, with a 
 mattress and such bedding as the season may render necessary, a tin urine 
 pot, a can of water and wash-hand bowl ; also a tin mug for drinking, 
 a bell-push with indicator in the corridor, and sundry minor articles. The 
 floor is boarded and the walls painted for about 5 ft. of the height, the 
 remainder of the walls and the ceiling being whitewashed. It was formerly 
 the invariable practice to fix in each cell not only a wash-hand basin with 
 waste pipe and cold water supply, but a water-closet apparatus. This, 
 however, has now been entirely dispensed with. A water-closet and a slop- 
 sink closet are provided at four different points on each floor, but these 
 water-closets are rarely used by the prisoners, who are not allowed to leave 
 their cells after being locked up at night, and ordinarily use the latrines out 
 of doors during the day. 
 
 In addition to the cell buildings there is, for each sex, a block of 
 reception wards where prisoners on first arrival are seen by the medical 
 officer, and the requisite hospital wards. The latter comprise accommoda- 
 tion for fifty men and twenty-nine women. The men's wards consist of 
 thirty cells, including two padded rooms, and two associated wards of ten beds 
 each ; the women's accommodation comprises six cells and two associated 
 wards — ten and five beds respectively — a lying-in ward for four patients 
 and an isolated ward for four. The amount of cubic space allotted to the 
 patients in the hospital cells is 1,400 ft., but in the associated wards, which 
 are not often more than half full, a much larger amount of space is available. 
 The buildings, which have been erected by convict labour, are exceedingly 
 well constructed, and it will be seen that the conditions under which the 
 prisoners are housed leave nothing to find fault with. It might perhaps be 
 contended that 350 is a large number to place together in one pavilion, 
 especially having regard to the fact that many of these undergo confinement 
 in their cells for twenty-three hours out of every twenty-four — being allowed 
 out for one hour of exercise daily — for some nine months after their first 
 admission. But looking to the large amount of air space afforded them, and 
 to the unceasing removal of vitiated air and renewal of fresh air that goes on 
 in every cell, independently of any other cell, as well as to the minute attention 
 that is paid to each prisoner, there is Httle possibility of his suffering any 
 ill effects from the conditions of residence in prison. 
 
 It is not only in England that the hospital plan of arranging prison 
 buildings is being adopted. In France the new prison at Nanterre,^ near 
 Paris (fig. 127), built to hold 1,000 men and 600 women, is arranged entirely 
 in separate blocks or pavilions. True, the class of inmates is somewhat 
 different from that of our convict prisons, comprising as it does prisoners 
 in the ordinary sense of the term, and mendicants or tramps, together with 
 sick- accommodation for both classes ; but these are divided amongst sixteen 
 distinct blocks or pavihons connected together, and with the chapel and 
 administrative offices, by means of covered ways open at the sides. 
 
 BAEEACKS 
 
 These buildings, like prisons, hospitals, and other domicihary institutions 
 whose fundamental condition involves the aggregation of large numbers of 
 human beings, have in the past formed no exception to the disastrous results 
 that have ensued everywhere from the non-observance or neglect of those 
 
 * M. Hermant, architect.' 
 
696 HYGIENE 
 
 hygienic conditions -n-liich are essential to the maintenance of the inhabitants 
 in a proper state of health. In all the greater nations of Europe the same dif- 
 ficulties in regard to healthy dwellings for troops have been experienced, and 
 during the present century, when standing armies have been vastly increased 
 in magnitude, these difficulties have become more accentuated. In times of 
 war the results of either ignorance or neglect of the most ordinary rules of 
 hygiene have, over and over again, led to the most terrible loss by sickness 
 and death. This, however, may be to some extent accounted for by the 
 exigencies of warfare, the arrangements being perhaps only temporary ; but 
 that such results should have occurred in times of peace, when every arrange- 
 ment is made with the utmost deliberation, and the buildings are provided 
 for the permanent dwelling of the men, is a far more serious matter. The 
 lessons gained at so much cost, both of life and money, in various campaigns 
 in Europe and America, during the third quarter of the present century, 
 have tended to produce a universal reformation in barrack arrangement, 
 which, however, it has mifortunately not been found practicable to fully 
 carry out, and consequently, where old barracks have been retained, even 
 though costly alterations, as palliatives, have often been effected in them, 
 evil results due to the same causes have still occurred. Not only has this 
 been the case in the British Possessions, but especially in France, Germany, 
 Austria, and Italy, with their large armies, similar difficulties have been 
 experienced. 
 
 The old French plan, advocated by Vauban in the middle of the last 
 century, of forming a barrack for a large number of men^ — a whole regi- 
 ment — in one huge building arranged round the four sides of a quadrangle, 
 judged by our present knowledge, was bad enough, but it was rendered far 
 worse later on, when owing to the general increased strength of the per- 
 manent armies, these already huge buildings were enlarged by additional 
 storeys or otherwise, until they would hold 2,000 or even 3,000 men. 
 Notwithstanding extensive systems of artificial ventilation that were in- 
 troduced, notably m the Prussian and German barracks which had been 
 thus enlarged, it was found that the rate of sickness and mortality invariably 
 increased. Mons. Toilet, an eminent French civil engineer, who has paid 
 much attention to the construction of harracks and hospitals, since he noticed 
 the deplorable condition of them while he served in the Corps clu Genie during 
 the Franco-German war, writes in 1882 that during ten years France lost 
 40,000 men in the barracks, while some 60,000 men, who had entered the 
 service in good health, were discharged on account of illness or infirmity. 
 Typhoid fever alone is said to have killed 12,000 men. This disease and the 
 destructive lung disease commonly known as phthisis appear to have been 
 the chief causes of this terrible loss, and the late Dr. Parkes pointed out how, 
 in our own barracks, both at home and abroad, as well as in those of many 
 other nations, these two diseases are intimately connected with defective 
 dwellings, the one pointing to bad drainage arrangements, and the other to 
 the constant breathing of an atmosphere vitiated by respiration. 
 
 In our own country, previous to the end of last century, barracks were 
 rarely constructed, owing, among other reasons, to the strong antipathy 
 of the people to support anything in the shape of a standing army. 
 There were a few garrisons for fortified towns and there was the body- 
 guard for the protection of the person of the sovereign, but there was 
 no considerable standing army. The first barrack proper that was con- 
 structed in London, apart from that for the garrison at the Tower, was 
 that built for the Horse and Foot Guards at the Palace at Whitehall on a 
 portion of the site of the present Horse Guards. In 1716, a project, of 
 
THE DWELLING 697 
 
 which the plans are still preserved, was put forward by an architect 
 named Nicholas du Bois, for an immense barrack for some 7,000 men 
 to be erected in Hyde Park. It comprised a range of buildings four 
 storeys high, including garrets, 1,335 ft. long, by 360 ft. deep, and was to 
 stand near the south-east corner of the Park, parallel with what is now 
 Park Lane. It enclosed three quadrangles, the middle one being 597 ft. long 
 by 281 ft. wide, and each of the other two 281 ft. square ; and the interior was 
 divided into a multitude of small rooms of equal size (about 20 ft. x 20 ft.), 
 placed back to back, and intended for twelve men in each. The plans include 
 a small infirmary placed on the south boundary against some adjacent 
 houses and with only a northern aspect, also a chapel with (significantly) a 
 graveyard on each side. This barrack, which, however, was never erected, 
 affords a fair sample of the kind of building then considered suitable for the 
 purpose. 
 
 By 1740 a few barracks of very makeshift sort had been erected in dif- 
 ferent localities, and in 1786 a military department was formed, and a number 
 of barracks were hastily begun, but were speedily suspended. Later on — 
 1793-97 — barracks were built in all the more important towns, but these, as 
 might be expected, were of a very defective type. It was not, however, until 
 after the Crimean war that the whole subject of barrack accommodation was 
 carefully studied. It was then (1857) found that while the death-rate of the 
 civil male population, between the ages of 20 and 40 years, was 9*8 per 1,000, 
 the mortality among the troops was 17'11, or nearly double. The barracks 
 of the whole kingdom were examined and reported upon by a special com- 
 mission and were found to be defective in many matters of primary import- 
 ance, and this inquiry led to a number of recommendations, which were 
 followed by regulations prescribing the superficial and cubical space to be 
 provided for each man ; the abolition of the offensive urine tub, that had 
 invariably formed one of the articles of furniture in every old barrack-room ; 
 the provision of separate quarters for the married men ; the provision of 
 baths, washing arrangements, workshops, reading and other recreation and 
 education rooms, and the regulating of warming and ventilation, water supply, 
 drainage, and sanitary details generally. The beneficial results of this im- 
 proved system of barrack construction speedily showed themselves in the 
 greatly diminished mortality and sickness among the men, for whereas in 
 1857 the mortality of the troops had been nearly twice as great as that of 
 the civil male population of the same age, in 1876 the mortahty of the troops 
 had been reduced to nearly 2 per 1,000 less than that of the corresponding 
 civil male population ; and the amount of hospital accommodation necessary 
 for troops has been diminished from 10 per cent, to 6 per cent. 
 
 Barrack construction for British troops is necessarily very diversified in 
 character, since our soldiers have to be quartered in every climate under the 
 sun, and what is most suitable for our home garrisons would be wholly un- 
 suited either to our tropical possessions in the Mediterranean, West Indies, 
 and India, or to the climate of our Canadian Dominion. In all these cases 
 the amount of space allotted to each man, and the numerous other arrange- 
 ments for maintaining his health and protecting him from the effect of 
 climate, have to be specially considered according to the particular local 
 circumstances. 
 
 For the temperate climate of the home countries the War Department 
 have issued a series of statements of the various requirements for barracks 
 for the several branches of the service, and in accordance with these a large 
 . number of barrack establishments have been erected in different parts of the 
 kingdom where military centres have been formed under the reorganised 
 
098 HYGIENE 
 
 arrangement of the home portion of our army.^ These modern barracks, 
 which are required to stand on a site of some ten acres in extent, exchisive of 
 training and encamping ground for mihtia regiments, are for the most part 
 planned upon the separate block system, and comprise a number of detached 
 buildings so placed relatively one to another as to admit of ample circulation 
 of air about them, and free access of light and sunshine. The infantry bar- 
 rack for a battalion of 850 rank and file of eight companies, with its proper 
 proportion of officers, non-commissioned officers, and married men, bringing 
 the total up to very nearly 1,000 of all ranks, with the necessary stabhng for 
 the field officers' horses, constitutes a formidable establishment involving 
 much care in the arrangement of the quarters in order to secure those 
 hygienic conditions necessary for maintaining the men, women, and children 
 in proper health. A cavalry regiment, consisting of some 80 officers and 
 nearly 650 non-commissioned officers and men, a few being married, and 
 their horses, or a battery of Eoyal Horse or Field Artillery, comprising some 
 six officers and 150 non-commissioned officers and men, with the necessary 
 troop-horses and gun-horses, is hkewise an assemblage that calls for excep- 
 tional consideration in regard to the hygienic arrangement of their dwellings. 
 In each of these instances provision has to be made for the social and 
 recreative entertainment and physical exercise, both of the officers and men, 
 in order to promote the maintenance both of mental and bodily health, and 
 arrangements have generally to be made for dealing with cases of sickness 
 or casualty, as well as for maintenance of discipline and for certain punish- 
 ments. For these purposes, besides the quarters for the officers and the 
 men, married and single, the complete barrack must comprise an officers' 
 mess, bilUard room, &c., and rooms for mess-man and servants, recreation 
 room, sergeants' mess, canteen, cook houses, guard house with cells and 
 prisoners' room, &c., Hbrary and reading-room, coffee room, gymnasium, 
 skittle alley, fives court, chapel-school, adults' school, children's school, and 
 a number of other offices and outbuildings. So far as the residential part of 
 these buildings is concerned, much criticism has been offered upon the absence 
 of day rooms and rooms m which the men should take their meals, the 
 ^ barrack rooms ' alone being requu-ed. According to the statement already 
 referred to, in a barrack for a regiment of infantry, thirty such rooms are 
 prescribed, each room being 77 ft. long by 21 ft. wide and about 10 ft. 6 in. 
 high. These ' barrack rooms ' afford accommodation for from 20 to 32 men, 
 giving about 600 cubic feet, and from 57 to 60 superficial feet per man. 
 Windows are required to be placed in the opposite side walls of these rooms, 
 about five feet super of window space (measured within the inside bead of 
 frame) being allowed to each man. The beds are placed in pairs about 
 eighteen inches apart between the windows, with their heads six inches from 
 the wall. It is certainly undesirable that meals should have to be taken in 
 the same room as is used for dormitory purposes, and it would be unfortunate 
 if the men were obliged to pass many hours of the day in these rooms ; but 
 seeing that the men are necessarily out of doors a good deal, and that other 
 rooms and places are pro\'ided in which they can read and amuse themselves 
 in a variety of ways both physically and mentally, there is little left for adverse 
 criticism on this head. The general arrangement is, in fact, an adaptation of 
 the plan now generally advocated for hospital buildings. As will be seen from 
 the annexed diagram (fig. 128), the barrack room must have ample means 
 of thorough ventilation ; a urinal, for night use only, is provided in a cross- 
 ventilated projection from the barrack room ; the ablution room is perhaps 
 rather small considering the number of men to use it, but it is well fitted up 
 ' The Military Forces Localisation Act, 1872. 
 
THE DWELLING 
 
 69» 
 
 .and includes a foot pan, which is said to be much appreciated by the men 
 
 These blocks are restricted to two storeys in height, and, when placed lon- 
 
 , gitudinally in parallel 
 
 rows, a clear distance 
 
 equal to at least twice 
 
 the height of the blocks, 
 
 from the ground level 
 
 to the eaves, has to be 
 
 provided between them. 
 
 The married men's 
 
 quarters are arranged 
 
 in a somewhat similar 
 
 block, but divided up 
 
 into thirty-one inde- 
 pendent sets of rooms, 
 
 each set consisting of a 
 
 living-room, bedroom, 
 
 and small scullery, with 
 
 a central staircase giving 
 
 access to an open gallery 
 on the upper floor, by 
 which the several sets 
 of apartments in that 
 storey are approached. 
 The block also includes 
 an infants' schoolroom 
 and a class room. 
 
 The views which 
 in this country have 
 prompted the complete 
 rearrangement in our 
 barrack buildings, and 
 the results that have 
 attended these changes, 
 have been duly noted in 
 certain other countries of 
 Europe. But it is chiefly 
 in France where improve- 
 ments on a large scale 
 are being effected. At 
 the International Con- 
 gress on Hygiene, held 
 at Paris in 1878, M. 
 Toilet, the civil engineer 
 already referred to, read 
 a paper on ' Les Loge- 
 ments collectifs, Hopi- 
 taux, Casernes, &c.,' in 
 which, after referring 
 to the reform that had 
 taken place and was 
 still being carried out 
 
 Mj^S^^:!t2:%oZ^"^^''' i-«»<i<»(eo/B„.i.;, Arcime^., Session 1880-81, 
 
 Fig. 128.1 
 
700 
 
 HYGIENE 
 
 in the English barracks, and to the large diminution of mortality and 
 sickness that had resulted therefrom, he urged with much force the extreme 
 necessity for similar reforms in France. In the following year M. Emile 
 Trelat, a well-known architect, who has done much for hygiene in France, 
 presented two important reports to the Societe de Medecine Publique, in one 
 of which, after referring in eulogistic terms to the steps taken in England under 
 the direction of Lord Panmure and Lord Herbert to improve the conditions of 
 the soldier, he laid down certain principles under which the French barracks 
 stood condemned. He pointed out that the barracks erected according to the 
 plan adopted previous to 1874 contained conditions which threatened the 
 wholesomeness of the buildings, that they held far too many soldiers under 
 one roof ; that they were unfortunately composed of many storeys ; that they 
 contained within the material of the walls themselves dangerous and offensive 
 matter which had been absorbed during long periods of occupation without 
 
 ^v 1 
 
 P Y no TEC H N/E 
 
 M 
 
 a 
 
 M 
 
 
 » / / / / 
 
 I 
 
 I// 
 
 H\ 
 
 ED 
 
 ^ 
 
 if 
 
 Fig. 129. — Block Plan of Artillery Barracks at Bourges. 
 
 AB, Entrance Pavilions; c Kitchens: d, Infirmary for Men; e, Latrines; F, Punishment Cells; 
 G, Canteen; h, Stables (ToUet System); i, Stables (Dock System); k, Veterinary Infirmary ; 
 L, Drill Sheds ; Jl, Watering place for Horses ; N, Lavatory ; p, Reserve Clothing Store. 
 
 eflScient ventilation ; and that the capacity of the buildings afforded insuf- 
 ficient cubic space per soldier. He continued that it was most urgent that 
 this state of things should be altered, and advocated the system of M. Toilet. 
 That system was adopted at the new barracks which were built shortly after- 
 wards at Bourges (fig. 129) ; it consists of a number of detached blocks, of 
 limited size and only one storey high, which afford a large amount of cubic 
 space to each man, while the aeration and ventilation of the interior is such 
 as to prevent the absorption into the walls of the offensive matters emanating 
 from continued habitation. 
 
 SCHOOLS 
 
 The hygiene of schools appears to have received a smaller share of atten- 
 tion from the specialist than the subject deserves. There are many valuable 
 reports and essays bearing indirectly upon the subject and upon particular 
 
THE DWELLING 701 
 
 aspects of it, but it can hardly be said to have been dealt with in as wide and 
 'Comprehensive a manner as is required. Hitherto, so far as the Education 
 Department of the Privy Council is concerned, no attempt appears to have been 
 made to treat of the hygiene of schools beyond the mere schoolroom and its 
 accessories, because that department is but little concerned with matters 
 other than educational. It would seem that health questions are at best of 
 .secondary importance there, and, if dealt with at all, they are not subjected 
 to that searching investigation by trained and skilled specialists that is 
 requisite to place them beyond doubt. 
 
 The Association of Medical Officers of Schools has undoubtedly done 
 good service in dealing with certain questions of school hygiene ; but this 
 again would seem to have reference more to school management and 
 administration and to the means of excluding infectious disease than to the 
 maintenance of the general health of the residents ; and even here the sub- 
 jects are not dealt with in their application to those numerous residential 
 schools to which children of the poorer classes are sent so much as to the 
 great public schools, which, as a rule, receive children of superior constitu- 
 tion. In fact, many very important questions bearing upon the arrangement 
 and construction of residential schools remain unsettled and even unformu- 
 lated. 
 
 There is certainly a general consensus of opinion that the amount of 
 floor-space and cubic-space commonly prescribed for each child in school- 
 rooms is very scanty, notably in those schools which come under the inspection 
 ■of Government, or in respect of which there is a grant of money calculated 
 upon the number of children and the degree of education attained, but no 
 serious effort has hitherto been made to get that amount of space increased. 
 Meanwhile, whenever any communicable disease is prevalent in a locality — 
 isuch as measles, scarlatina, diphtheria, &c. — the village school or the national 
 rschool is often found to be one of the chief means of disseminating the 
 disease. Although this is frequently the case, it is not invariably so. 
 There are instances where, in the same locality, it is alleged that one school 
 has been specially affected, while two or three other schools, in quite near 
 proximity, have been either very slightly affected or have even escaped alto- 
 gether. If this be so, there would seem to be ground for supposing that a 
 cause might be found for the diffusion of the disease in the one school and 
 the whole or partial immunity of the disease in the other schools. Can this 
 immunity be owing to any difference in the condition of the children them- 
 selves, or to better ventilation ; to a greater amount of cubic space per 
 child, or to a smaller number of children being ordinarily aggregated together, 
 or to any difference in the duration of school hours, or to some combination 
 of better conditions under which the children in the one or more schools are 
 rendered less susceptible, or the power of attack possessed by the disease 
 is diminished or removed ? It at least seems to deserve careful investiga- 
 tion and skilful inquiry. But this question is referred to as affecting schools 
 intended for educational purposes alone. If so important a matter applies 
 to those schools, how much more important is this question, and indeed a 
 number of other questions that might be suggested, in their bearing upon 
 the residential school, in which institution the children not only receive 
 education, but remain, night and day, for several years ; in which they sleep, 
 feed, play and receive such attention as is available in case of sickness ! Such 
 schools exist all over the country, whether as charitable institutions for 
 orphans and afflicted children, or Poor-law institutions for the children of 
 destitute persons and for deserted children, as well as a number of higher 
 class institutions of kindred purpose. Very little, comparatively, has been 
 
702 HYGIENE 
 
 hitherto done in the way of hterature upon this particular branch of the 
 subject. Schools, more especially residential schools, ought to be the fittest 
 place in every respect for the youth, of whatever age and of either sex. 
 Charitable institutions and other residential schools intended for the entire 
 care and education of the young are erected from time to time, but no 
 common plan or system appears to have been hitherto advocated. In the case 
 of hospitals certain general principles of arrangement are now universally 
 recognised. Not so, however, in the case of schools of the kind referred to. 
 They are generally arranged in any fashion that may commend itself to the 
 governing body for the time being, and accordingly every conceivable variety 
 of arrangement is to be met with — good, bad, and indifferent having been 
 alike adopted down to the present moment. 
 
 There are, for example, numbers of large residential schools and colleges 
 for upper, middle, and lower classes throughout the country, some affording 
 accommodation for several hundred pupils, in which the chief building, con- 
 taining the whole of the administrative, domestic, and educational depart- 
 ments, as well as the dormitories, is arranged two or three storeys high in the 
 form either of the letter E or the letter H, and in some instances it is 
 arranged rovmd the four sides of a quadrangle, or perhaps two sides of the 
 quadrangle are extended so as to form a second quadrangle. Another 
 example is where the school, though still one large block with projecting 
 wings, is subdivided internally into groups of some fifty children or more. 
 This is specially the case at the London Orphan Asylum at Watford. A 
 fui'ther variety of residential school is to be found in the Stockwell Orphan- 
 age, London, where the children occupy a row of houses (about thirty 
 children in each) specially erected for the institution. The Home for Little 
 Boys at Farningham in Kent, and the Princess Mary's Village Home at 
 Addlestone, Surrey, are examples of the cottage home system, the houses of 
 the former containing about thirty, and of the latter ten and fifteen children 
 each ; and the Philanthropic Society's Farm School (a reformatory school) 
 at Kedhill, Surrey, is another variety of the same system, but here the 
 several cottages contain an average of some sixty boys. A somewhat similar- 
 arrangement is in operation at many of the great pubHc schools for boys, 
 where the masters' houses are scattered about the town, and each contains 
 sleeping and day accommodation for some twenty or more boarders. The 
 institutions that have been erected under the auspices of the Poor-law 
 Authorities might fairly be expected to afford the best examples of what such 
 schools ought, hygienically, to be, since they have been provided under a 
 certain amount of continuous watching and supervision of the whole subject, 
 and with the experience gained during many years of systematic inspection ; 
 but even here no very definite conclusions appear to have been arrived at, 
 though certain comparatively recent experiences have led to the condemna- 
 tion of the principle of erecting a large residential school in one huge 
 building. The Local Government Board have certainly framed some useful 
 rules for the guidance of those proposing to provide schools for pauper 
 children, but much latitude has been left — and wisely so at present — as to 
 the precise system to be adopted in the arrangement of the building, great 
 hesitation being shown in advocating any particular plan. 
 
 The necessity for ensuring the best hygienic conditions in buildings for 
 children, of whatever social class, is more than ever important now that the 
 strain upon the child under the modern system of education is so much 
 greater than formerly, and consequently everything that may conduce to 
 counteract this strain and pressure of education is indispensable, whether it 
 concern the internal arrangements— the dormitories, the school and class- 
 
THE DWELLING 70S 
 
 rooms, the play and other day rooms and industrial work-rooms — or the 
 external arrangements, such as the playgrounds, playsheds, gymnasia, cricket 
 fields, and other outdoor provisions for recreative and physical training 
 and exercise. As regards these latter, it has to be borne in mind that in pro- 
 portion as the children belong to the lower grades of society, so do they 
 require greater inducements to take physical exercise — indeed, it has truly 
 been said by Mr. Nettleship, F.R.C.S., that children, especially those of the 
 poorer classes, will no more take spontaneously to recreative exercises and 
 games than they will spontaneously learn to read orwrite. Both Mr. Nettleship 
 and Dr. F. J. Mouat before him have pointed out that the children of the lower 
 classes must be taught to play games out of doors, to swim, and otherwise to 
 take active exercise. While in the high class public schools the boys have a. 
 sort of hereditary liking for games involving considerable physical exertion, and 
 which, by means of permanent clubs, are perpetually kept up, the children in 
 the schools of the poorer classes are more apathetic, and unless the teaching 
 staff systematically teach the children how to play and enter into the games- 
 with them, there will almost certainly be a strong tendency on the part of the 
 children to idle about the most objectionable parts of the yards and places 
 provided for them to play in, the result of which is likely to be the reverse of 
 beneficial, and to induce a prejudicial habit of loafing, and this notwithstand- 
 ing that every requisite for games is provided. A further point that is often 
 insufficiently appreciated in the laying out of schools of the class referred to 
 is the secondary consideration that is given to the extent and suitabihty of 
 the recreation grounds, since it not uncommonly happens that the larger 
 portion and better situated land is set apart for purposes of profit in the 
 shape of potato and cabbage gardens, farming, &c., instead of being regarded 
 as primarily requisite for recreative outdoor exercise by the children. And 
 this tendency to exaggerate the importance of farming, to the sacrifice of the 
 physical exercise of the children, is fostered by the circumstances that the 
 superintendent of the institution is often able to show a considerable profit 
 upon his farming account for the year, and thus he becomes converted from 
 a school superintendent, whose first care should be for the children com- 
 mitted to his charge, into a mere farm bailiff. 
 
 As regards the hygienic conditions that have to be observed in the- 
 arrangement of the residential school building itself in which children have 
 not only to be educated, but maintained and cared for during every condition 
 of health and sickness that may occur from early infancy until they are 
 able to go out into the world to earn their own living, it is not too much to 
 say that the principles usually apphcable to hospitals are equally appli- 
 cable to such schools. The child may fairly be regarded as a most sensi- 
 tive instrument, which indicates very promptly, and with much precision,, 
 any variation of the health conditions under which he is placed. 
 
 The only class of such institution that has hitherto been systematically^ 
 under observation would seem to be the Poor-law schools throughout the 
 kingdom. In these schools — chiefly in the larger ones — a variety of com- 
 plaints have prevailed amongst the children which have formed the subject of 
 much inquiry. Ophthalmia, itch, and diseases of the skin and scalp have hung 
 about some of these schools for long periods, often with results now known to- 
 be hfe-long in their prejudicial influences. The mortality rate of these schools 
 is often quoted by those interested in regarding them favourably as indicating 
 their good condition, but this is a very indifferent test. A far better one is 
 to be found in the rate of sickness, and this in some instances has been 
 ascertained to be as high as 25 per cent, of the inmates. Dr. P. J. Mouat,. 
 who had large experience of the Poor-law schools, has pointed to a variety 
 
704 HYGIENE 
 
 of affections that may be fostered in some of these schools.^ He says : ' The 
 stunted, impaired general health, and feeble bodily powers of too many of such 
 children are not removed or corrected by massing them in large buildings or 
 groups ; ' and he suggests that ' there is a large and possibly increasing factor 
 of imbecility, idiocy, and nervous disorders generally, and some of the more 
 immetUate results of scrofula at the critical periods of life, which may be due 
 to the insanitary conditions ' inherent to the aggregation of large numbers of 
 children in such huge buildings. 
 
 But the complaint that has served most readily to indicate the defects in 
 hygienic arrangement in these schools has undoubtedly been ophthalmia. 
 Instances could be cited in which it had prevailed incessantly to an un- 
 fortunately large extent for many years, notwithstanding the most indefati- 
 gable, skilful, and indeed enthusiastic attention of the school authorities and 
 medical oflBcers in charge. Mr. E. Nettleship has asserted that this disease ' is 
 the touchstone of the general healthiness of an institution.' He says, too : 
 ' Where many persons are herded together their eyelids show sooner and more 
 certainly than any other part if the conditions of vigorous health are not 
 complied wuth.' The disease was formerly common in the army and navy, 
 but with improved hygienic conditions in the barracks and ships it has 
 been practically abolished. Travellers in the East have always been struck 
 with the remarkable number of blind persons, and poor people suffering with 
 ophthalmia, who are met with in all Oriental towns and villages where intense 
 crowding and other insanitary conditions permanently exist. The intensity 
 of the disease varies much according to the surrounding conditions, but in 
 the large Poor-law schools, both provincial and metropolitan, it has certainly 
 given much trouble, and accordingly it seems probable that advantage would 
 result from a careful and systematic study of the effects resulting from the 
 various arrangements of building that have been tried in the case of these 
 schools. In those domiciliary schools where the children are usually of a 
 higher class, the tendency to disease consequent upon indifferent hygienic 
 arrangements may and doubtless does exist, ^ though in a sUghter degree by 
 reason of a variety of circumstances such as the superior condition under which 
 most of the children are reared before being sent to school, and the fact of 
 the children in these schools having the advantage of periodical change 
 during the three usual annual vacations, when they go home or to stay with 
 friends. These circumstances would probably tend to arrest or divert some 
 of the evil results that might otherwise ensue were they to have the same 
 continuous and uninterrupted residence in school which the children in the 
 Poor-law schools have necessarily to endure. And it seems probable that 
 the pallor and lassitude often noticed in children of this higher class at the 
 end of a term, and which is commonly attributed to hard work in school, is 
 in reality more or less due to the conditions of aggregation and defective 
 ventilation referred to. 
 
 Some allowance must certainly be made for the low standard — mental, 
 moral, and physical — of the majority of the children of Poor-law schools 
 when comparing them with the higher-class children just referred to, and even 
 with those of the labourer or artizan who has struggled successfully with 
 the trials and inconveniences of very limited means ; but this would scarcely 
 diminish the usefulness of the investigation above suggested. The mere 
 history of Poor-law schools is in itself instructive. In the early workhouses 
 
 ' Paper on the Training and Education of the Children of tlie Poor. Kead before the 
 Statistical Society, April 20, 1880. London : Stanford & Co. 
 
 ■■^ Mr. Nettleship, in his licport on Ophthalmia in the Metropolitan Pauper Schools 
 1875, states that he has found the disease prevalent in certain other han Poor-law schools. 
 
THE DWELLING 705 
 
 of 1835-40 the children were but imperfectly separated from the adult indoor 
 paupers. Later on, as increased accommodation for the indoor poor became 
 necessary, the children were moved into a detached building still situated on 
 the workhouse premises ; and gradually it was found desirable to remove the 
 children altogether away from the workhouse wherever their number was 
 such as to make such a plan feasible. By degrees the children from the large 
 workhouses of the metropolis and some of the provincial towns were provided 
 for in separate institutions in the suburbs — an arrangement which was un- 
 doubtedly a vast improvement in many ways. But with the aggregation of 
 such large numbers of children— for in many instances several Poor-law unions 
 combined, under statutory power, to provide for the children belonging to those 
 unions in one large institution — fresh difficulties arose, and amongst these was 
 that of maintaining the children in good health. 
 
 Notwithstanding the removal of the children from the more densely 
 populated areas in the towns and metropolis where the workhouses were 
 situated to newly erected buildings designed specially for the purpose, and 
 situated on large sites in the comparatively open country, it has become 
 only too evident that this alone was quite inadequate to keep them in a 
 proper condition of health. For many years past the children so circum- 
 stanced have suffered repeatedly, or more or less continuously, from various 
 complaints, but the disease that has prevailed and given more trouble than 
 any other has been ophthalmia in various stages of severity. And when 
 once any complaint of that character gets into an institution of the kind 
 containing under its one roof a vast number of children, it has been found 
 most difficult to get rid of it. The best advice available has been obtained, 
 specialists have been called in as consultants, and large sums of money 
 have been expended in the hope that the complaint would be eradicated 
 and the health of the children re-established, but with very indifferent 
 success. 
 
 These large institutions with vast aggregations of children have come 
 to be regarded more or less as failures ; and, as in the case of hospitals 
 and other institutions, subdivision of building, on the principle of separate 
 pavilions, is pointed to as one of the chief means of arresting the evils 
 complained of, and a most important means of preventing the recurrence 
 of them.^ Accordingly, in recent years residential schools for considerable 
 numbers of children have been arranged either in distinct blocks or pavilions, 
 each to contain a very limited number of children, or upon what is now known 
 as the cottage-home system. On both of these systems many residential 
 schools have been erected both under the Poor-laws and also for charitable pur- 
 poses ; thus as an example of the former of these systems the London Orphan 
 Asylum at Watford may be referred to — an excellent charitable institution 
 consisting of a number of independent blocks, attached or semi-detached, 
 but without any internal communication one with another, each containuig 
 dormitory and day accommodation for about fifty children, with apartments 
 for an officer in charge, grouped about the necessary administrative and 
 educational buildings. The cottage-home system is more modest in character 
 and admits of greater diversity in design, comprising as it does a sort of 
 complete village, the cottages being sometimes of different sizes and design, 
 and either detached, semi-detached, or in rows. Each cottage is usually in 
 charge of a foster mother or foster parents, the ' family ' comprising a number 
 
 ' So mucli is this subdivision of building recognised as necessary for purposes of health 
 that in one large Poor-law school at Hanwell the main building, which is upwards of 
 600 ft. long, has recently been divided into five distinct blocks by having gaps cut 
 through it at four points in its frontage. 
 
 VOL. I. Z Z 
 
706 HYGIENE 
 
 of children varying from about ten to as many as thirty, sometimes exclu- 
 sively of one sex and occasionally of both sexes, according to the ages and 
 characters of the children. The ' village ' usually includes a school building, 
 industrial workshops, and such other buikhngs in the way of infirmary, 
 probation wards, superintendent's house, &c., as the circumstances necessitate ; 
 but these are eonnnonly of very modest pretensions, as one of the cottages in 
 a slightly modified form can be made to serve each or any of these purposes, 
 and the need for infirmary accommodation in these villages is never very 
 great, while in each ' home ' a small spare bedroom is generally provided in 
 which a case of slight indisposition may be temporarily separated from the 
 other children so as to be more directly under the observation of the foster 
 mother. 
 
 Schools on the family system, with agricultural labour as the chief 
 industrial training, have been in operation on the Continent much longer than 
 here, for Pestalozzi iiitroduced into Switzerland farm schools on this plan 
 shortly after the middle of last century,' and the reformatory school at 
 ]\Iettray, similarly conducted, has been in existence for nearly fifty years ; 
 but even in the United Kingdom the system has been in operation, both 
 under the Poor-laws and at charitable institutions, a length of time suffi- 
 cient to warrant an opinion being formed regarding it, and in tlais particular 
 it seems to leave little to be desired, especially as regards the health of the 
 children. - 
 
 It would seem that until within recent years one of tlie chief hygienic 
 defects in the arrangement of residential schools consisted in the undue aggre- 
 gation of the children. They occupied a huge buildmg three or more storeys 
 high, large numbers were placed together in each dormitory, the dormitories 
 were situated along both sides of a corridor which had well-holes in its floor for 
 the passage of light from the roof of the uppermost one down to the lowest 
 one, and the school and day rooms in the lowest storey were similarly placed 
 and were occupied continuously by large numbers of children ; and thus the 
 whole building was arranged so as to contain one atmosphere uniformly 
 vitiated by the exhalations of a vast number of individuals as well as by other 
 common means of contamination. These arrangements undoubtedly tend to 
 lower the standard of health and to foster any tendency to disease that may 
 already exist in the individual children, while they cannot fail to promote 
 the intercommunication of any complaint that may be introduced among the 
 children. The remedy for this defective condition is to be found mainly in 
 the converse of the arrangement. The children, instead of being aggregated, 
 must be segregated everywhere. The buildings must be subdivided into 
 detached separate blocks ; the dormitories must be of more moderate size, 
 and, as well as the school and day rooms, must have as good means of venti- 
 lation as is usually required in the case of hospital wards. The school- 
 rooms must afford increased area per child, and inasmuch as it is said to 
 be necessary to have considerable numbers together for purposes of teachmg, 
 the occupation of the schoolroom must be limited to comparatively short 
 periods between complete evacuation and exposure to fresh air by open 
 windows ; and arrangements should be made for conducting a fair amount of 
 
 ' Statistics of the Farm School System oil the Continent. By Joseph Fletcher. 
 London : Stanford & Co., 1878. 
 
 - For a further account of the system see Report of Dr. F. J. Moiiat and Captain J. D. 
 Bowly, R.E., on The Home or Cottage System of Training and Educating the Children of 
 the Poor. London : Printed for the House of Commons, 1878. Since the date of that 
 report a number of schools on this system have been built in various Poor-law unions 
 of England and Wales, notably, for Birmingham, King's Norton, Wolverhampton, Leicester, 
 West Derby, Shoreditch, Bethnal Green, Kensington and Chelsea, &c. 
 
THE DWELLING IQl 
 
 school teaching in the open air, under cover if necessary, whenever the 
 weather will permit. For this purpose large trees are excellently adapted in 
 hot summer weather, and whenever such trees exist ahout a school or on the 
 site of an intended school every effort should be used to retain them. 
 
 The rules of the Education Department as to the planning and fitting up of 
 schools state generally that ' sanitary laws are here as vital as in a hospital,' 
 and, under the head of ' Windows,' the ordinary rules respecting hospitals 
 should here be remembered. Hence it may be inferred that through- venti- 
 lation by means of opposite external windows is deemed requisite in school- 
 rooms erected under the auspices of that department, as it is in the case of 
 schoolrooms for pauper children erected under the authority of the Local 
 •Government Board ; but the important question of the number to be assembled 
 together in any schoolroom does not appear to have been dealt with, the first 
 point considered in planning a school being how ' to seat the children in the 
 best manner for being taught,' and this tendency to aggregation of unlimited 
 numbers has been noticed by Mr. Nettleship when, in reference to ophthal- 
 mia in a large school, he observed that hardly any attempt seemed to have 
 been made to treat the children otherwise than collectively. As, however, it 
 is admitted that the observance of sanitary laws is as important in a school 
 as in a hospital, it is certain that children cannot be aggregated in a school- 
 room with impunity any more than patients can be safely aggregated in a 
 sick-ward. The length of time the children are kept in school being only 
 a few hours at a stretch may cause the prejudicial effects to be less readily 
 observed than in the case of the patients in continuous occupation of a sick- 
 ward, but that evil results ensue from massing large numbers together in 
 schoolrooms will be generally admitted. These evil results will be increased 
 or diminished in intensity, but not wholly removed, in proportion to various 
 circumstances — e.g. the general health condition of the children, the amount 
 of floor area and cubic space allotted to each child in the room, and the 
 efficiency of the ventilation and warming of the room ; but the question of 
 the maximum number that may properly be collected together in the school- 
 room — and in this must be included those classrooms which open out of the 
 schoolroom or are in direct aerial communication with it — must ere long 
 be more generally considered in order to promote the subdivision of the 
 children. 
 
 The amount of space for each child in a schoolroom is a detail which in 
 recent years has received more attention than formerly ; for while it was 
 usual to require merely an average amount of floor space for each child, with 
 a specific height for the room, it is now customary to determine the accom- 
 modation of a schoolroom by the number of children that can be properly seated 
 in it, regard being had to the kind of desk and to the positions of the doors and 
 fireplaces ; and thus, in a room otherwise well suited for the purpose, much 
 space may be sacrificed, so far as the number of children to be accommodated 
 is concerned, owing to the arrangement of these details. This lost space is 
 usually described as ' wasted,' but inasmuch as it tends to increase the other- 
 wise very small quantity of cubic space available for each child, this term is 
 hardly a desirable one. The requirements of the Education Department 
 prescribe a width of from 18 ft. to 20 ft. or 22 ft. for a schoolroom, and 
 state that if the width does not exceed 20 ft. groups of three long desks 
 must be used, but if the width is 22 ft. dual desks, five rows deep, must be 
 used. It is further stated that a length of 18 inches is to be allotted to each 
 child on the long desks, with gangways 18 inches wide between the groups, 
 and in the case of the dual desks, which are 40 inches long, the gangways 
 between them need be only 16 inches. The height of the schoolroom must 
 
 zz 2 
 
708 HYGIENE 
 
 be from 12 ft. to 14 ft. These dimensions give an average floor area of 
 rather over 10 sq. ft. to each child, with cubic space of about 123 ft. (calculat- 
 ing the height at 12 ft.) In the case of workhouse schools, where the dormitories 
 are sometimes placed above the schoolrooms — an arrangement which tends to 
 fix a width of 18 ft. only for the schoolrooms — the amount of floor area and 
 cubic space per child is slightly less, averaging about 9} sq. ft. and about 
 111 cub. ft. of space per child. In the case of infants' schools the Education 
 Department are satisfied with a floor area of only 8 ft. per child, which gives 
 scarcely 100 cub. ft. per head. 
 
 These capacities are obviously very small, and can only be justified 
 on the supposition that the warming and ventilation arrangements are so 
 complete that the air of the room will be constantly changed without 
 creating draught and without unduly affecting the temperature of the room, 
 whatever may be the condition of the external atmosphere. But unfor- 
 tunately this is only a supposition, since in actual practice it is found 
 impossible to ensure these important conditions, the more so as it is not 
 usual to employ anyone possessmg that interest in the subject and tli& 
 practical skill which are indispensable for efficiently regulating the warmth 
 and ventilation at all seasons of the year. The best alternative to this in- 
 efficient control of constant ventilation seems to be the provision of a larger 
 amount of cubic space per child without unduly increasing the usual height 
 for schoolrooms, and it cannot be too strongly urged that this should be 
 generally effected. Mr. Charles E. Paget, Medical Officer of Health at 
 Salford, in his ' Handbook on Healthy Schools ' ^ advocates 400 cub. ft. of 
 space per child as a minimum in elementary schoolrooms, and 800 in the 
 schoolrooms of the great public schools. Where the schoolroom is of the 
 requisite size for the whole number of children attending school, and class 
 rooms are provided in addition, as is prescribed under the Poor-law require- 
 ments of the Local Government Board, it follows that a very substantial 
 addition to the space per child is afforded in the schoolroom, since many of 
 the childi'en are absent from that room for considerable periods when attend- 
 ing classes in other rooms or undergoing industrial training, and the remain- 
 ing children get the benefit of the additional space in the schoolroom. 
 
 The arrangement of windows for lighting the schoolroom should be such 
 that the light should be admitted as much as possible on the left-hand side 
 of the pupils. This is more particularly necessary in the classrooms. In 
 any case it is important to avoid so arranging the windows that a strong 
 light is admitted directly in face of the children, as this would aggravate any 
 tendency to weakness in the eyes. A strong light behind the children is 
 objectionable for educational reasons. From a hygienic point of view there 
 is advantage in placing the desks in a schoolroom across the room, so that 
 the children should pit with the windows on their sides, the ^\indows admit- 
 ting the strongest hght being on their left-hand side, the other windows being 
 adapted mainly for purposes of ventilation. The sills of the windows may,. 
 with some advantage, be at a higher level than is usually deemed desirable 
 in ordinary day rooms, a height of 4 ft. or 4 ft. 6 in. above the floor being 
 a useful average height for them in schoolrooms. They should, however, 
 invariably extend up to within a few inches of the ceihng level. 
 
 In addition to the school and class rooms the residential school must 
 include those other rooms which are necessary out of school hours in order 
 that the children may be able to vacate the schoolroom at intervals for 
 purposes of recreation when the weather does not permit of their being out 
 of doors, and where they may pass the long winter evenings. Such rooms, 
 
 ' Health Exhibition Literature, vol. i. London : William Clowes & Sons, 1884. 
 
THE DWELLING 709 
 
 •which are usually termed day rooms, should, according to the rules of the 
 Local Government Board, afford floor area of at least 10 square feet per 
 child, and be from 10 to 12 feet in height. This amount of space, how- 
 ever, is regarded by some authorities as very scanty. Mr. C. E. Paget urges 
 the provision of space at the rate of 1,000 cubic feet per child, renewable 
 at the rate of 2,000 feet per child per hour. These rooms should be well 
 ventilated by windows opening into the external air in their opposite side 
 walls, and are best situated upon the ground floor, so as to be ready of access 
 "to the playgrounds. Like the schoolrooms, they should have a solid floor of 
 wooden blocks, and must be capable of being suitably warmed in winter. 
 They ought not to be used by the children for taking their meala in, but a 
 separate hall or dining-room, well ventilated and warmed, is indispensable 
 for that purpose. The dining-room must be so arranged, as regards the 
 domestic offices and its means of ingress and egress, that the food should 
 be served to the children in a hot and palatable condition. It is a most 
 unfortunate thing for the children if the food intended to be eaten hot is 
 allowed to get chilled before it is served to them or before they can reach 
 their seats and commence their meals. Such conditions are apt to lead to 
 the food being wasted instead of being consumed by the children, and it may 
 here be pointed out that the meals at boarding-schools are sometimes 
 arranged at such considerable intervals that the children cannot be deprived 
 •of any portion of the food served to them without disadvantage. 
 
 In residential schools the dormitories are usually in the one and two pair 
 storeys, and the arrangement generally ought to follow that prescribed for 
 wards for the sick, with such modifications only as may be desirable under 
 the different circumstances for which the dormitories are to be used. The 
 usual width in the case of Poor-law schools is 18 feet, each bed, according 
 to the requirements of the Local Government Board, havuag a minimum of 
 3 feet 9 inches of wall space, 36 square feet of floor space, and 360 cubic feet 
 •of air space. If the dormitories are 15 feet wide the wall space has to 
 be increased to 4 feet. These amounts of space are certainly the least that 
 could be allowed with propriety, but they are in excess of what was 
 formerly considered requisite when, moreover, the children were commonly 
 permitted to be placed two in a bed — an arrangement which is now 
 prohibited. Dr. Clement Dukes, in discussing the subject of school 
 •dormitories at a conference at the Health Exhibition in 1884,^ points out 
 that a plentiful supply of sleep in dormitories affording ample and pure air, 
 is as important to the young and growing as a plentiful supply of food, and 
 he believes that, notwithstanding this, some 50 per cent, of the dormitories 
 ■in the boarding-schools of Great Britain ' would be found to be as bad as 
 they could possibly be, and 40 per cent, just passable, but nothing Mke what 
 they should be.' He further points out as ' an incontrovertible fact ' that in 
 many of our schools there is less than 300 cubic feet of space per head in 
 the dormitories. 
 
 In France, among the rules laid down for the construction and furnish- 
 ing of normal schools by the Covimission des Bdtiments Scholaires, it is 
 •prescribed ^ that the dormitories are never to hold more than thirty beds, are 
 to have windows in their opposite side walls, are to be at least 4 metres high 
 and 7^ metres wide, that the space between the beds shall be at least a metre 
 wide, and that as the beds are 80 centimetres wide each bed shall have a wall 
 space of 1 metre 80 centimetres, and floor area of about 6| square metres and 
 
 ' Health Exhibition Literature, vol. si. London : William Clowes & Sons, 1884. 
 2 L' Etude et les Progres de VHygiene en France de 1878 d 1882. Paris : G. Masson, 
 •Miteur, libraire de I'Academie de Medecine, 1882. 
 
710 HYGIEXE 
 
 about 27 metres of cubic space. The rules go on to prescribe that, where 
 movable curtains to separate the beds are not adopted, the Commission 
 recommend cubicles (cabines) at least 2 metres 75 centimetres deep by 
 
 1 metre 80 centimetres wide, with a central passage 1 metre 50 centimetres 
 wide. If preferred, the cubicles may be placed in two rows against a central 
 longitudinal pai-tition with a passage a metre wide along each side of the 
 dormitory. The partitions separating the cubicles are to be not more than 
 
 2 metres high, and raised at least 20 centimetres off the floor, and each 
 cubicle is to be furnished with merely a bed, a stool, and a clothes-box. It 
 is stated, however, that the system of cubicles is not generally adopted. 
 "Whether the cubicle system or the open dormitory is adopted, there is, 
 according to these rules, a very large amount of space available for each 
 pupil, and, as the cubicles are not furnished for use otherwise than for 
 sleeping, they can be thoroughly aired during the day. It is perhaps 
 hardly to be expected that so much space can be generally given to each boy 
 or girl in school dormitories of institutions and inexpensive schools in this 
 country, but as a general rule the amount of space afforded is very in- 
 adequate. Both Dr. Dukes and Mr. C. E. Paget advocate for our climate 800 
 cubic feet of space, with some 70 square feet of floor area for each child, 
 it being urged that with less space it is often impracticable to ensure efficient 
 ventilation -v^ithout draught. Moreover, the beds must be kept at a sufficient 
 distance apart in order to diminish the risk of any complaint or constitu- 
 tional disorder being communicated from the occupier of one bed to that of 
 the next bed. Dr. Dukes further expresses the opinion that from ten to 
 sixteen beds in each dormitory is an appropriate number. 
 
 Upon the question of the advantages and disadvantages of the cubicle 
 system opinions seem to differ, there being perhaps as many and as powerful 
 advocates for the one system as for the other. That cubicles, except under 
 very good general administration, are capable of abuse and may tend to 
 prejudice the moral as well as the health condition of a school can hardly 
 be doubted. Dr. Dukes regards them with much disfavour, and Dr. Alder 
 Smith considers them ' an abomination in every way ; ' but on the other hand 
 Mr. C. E. Paget, in his paper on Healthy Schools, already referred to, records 
 his opinion as decidedly favourable to the cubicle system in well-managed 
 schools. All authorities, however, agree in the necessity, from a health point 
 of view, for the absolute prohibition of the use of the cubicles for purposes of 
 study. In fact, no kind of occupation should be allowed in the dormitories 
 or cubicles during the day. One important advantage of the cubicle over 
 the open dormitory, however, is that it practically necessitates the pro- 
 vision of a greater amount of cubic space than where the beds are placed 
 along the sides of an open dormitory, and where they may consequently be put 
 closer together if the number of children to be accommodated renders it 
 necessary. "Where the beds have each only a very small amount of wall space 
 it is practically impossible to avoid placing some of them immediately under 
 the windows, an arrangement that should always be avoided as far as possible. 
 
 The flooring of dormitories for children should be of well-seasoned board- 
 ing, properly grooved and tongued, and whether stained or not should be 
 polished with bees'-wax or paraffin. This is far better than that frequent 
 washing and scrubbing which is so often effected in many schools, and which 
 m damp weather is so difficult to get dry by the children's bedtime. 
 
 The question as to the best arrangements for purposes of ablution in the 
 residential school is one which requires the most careful consideration, since 
 the cleanhness of the skin is of such importance to the health conditions of 
 the children. As regards lavatories it has been alleged, with much apparent 
 
THE DWELLING 111 
 
 reason, that one of the means by which ophthalmia has been spread amongst 
 the children in pauper schools has been not only by the use in common by 
 several children of the same towel, but also by the wash-hand basins being 
 imperfectly rinsed after use, so that secretions discharged from the diseased 
 eyes of one child have been left in the basin, and been allowed to mingle 
 with the clean water used by the next child washing at the same basin. 
 Although this means of communication of disease has not been actually 
 proved, its probability affords a strong a priori reason for guarding against 
 such a possibility, and consequently not only have round roller towels been 
 practically abolished in most Poor-law schools, but the use of ordmary wash- 
 ing basins in them, especially the larger schools, has been done away with, 
 and an arrangement substituted by which each child washes at a running jet 
 or spray of water, so that it is practically impossible for the same water to be 
 used by more than one child. The water, which can be delivered at any 
 required temperature, falls into surface channels on the floor behind slate 
 slabs to protect the children from splashing, and experience has shown that 
 the quantity of water consumed under this system can be so regulated as 
 scarcely, if at all, to exceed that ordinarily used in wash-hand basins, while 
 the children are able to thoroughly wash the whole upper part of their bodies. 
 The system had been in use for many years at the Eoyal Military Asylum at 
 Chelsea before it was adopted, some fifteen years ago, in certain Poor-law 
 schools, but the details of arrangement have since been improved in various 
 ways. The necessity for supplying hot water to children's lavatories is some- 
 times regarded as a needless expense, it being contended that such a luxury 
 is not met with in the ordinary dwelling of other than the well-to-do classes. 
 But it is at least necessary in the case of children of the low condition of 
 vigour and vitality usually met with among the very poor, and accordingly 
 in most pauper schools it has been found desirable to require an adequate 
 supply both of hot and cold water, and it is recommended that the lavatory 
 arrangements should be such as will admit of each child washing the hands, 
 face, and upper half of the body at least twice daily. For this purpose 
 it is requisite to provide jets, or basins where the running-jet system 
 is not adopted, in the proportion of fifteen jets or basins to every hundred 
 children. 
 
 With regard to the important question of baths for the children it is much 
 to be wished that the practice of daily bathing for every boy or girl could be 
 carried out in all schools. This, even in some of our best public schools, is 
 regarded as impracticable, but the daily cleansing of the skin by means of 
 cold bathing and friction has so many hygienic advantages that it is desirable 
 to aim at this practice as nearly as the circumstances permit. For very 
 young children, however, and children of the poor condition already referred 
 to, the use of cold water at all seasons would hardly be right, and therefore, 
 for those children at any rate tepid or warm baths should be provided. The 
 regulations of the Local Government Board prescribe that the bathing 
 arrangements in Poor-law schools should admit of every child being bathed 
 at least once a week in winter and twice a week in summer, and certainly m 
 other residential schools the facilities for bathing ought not to be less. 
 Glazed fireclay baths, such as are made at Stourbridge, are among the best 
 adapted for the purpose, as they are very strong, the surface is durable and 
 can be kept clean without difficulty, and they do not require casing in. They 
 absorb a certain quantity of heat from the water, but where they are used by 
 a number of successive bathers, as is the case at schools, being of course 
 emptied and recharged repeatedly, the loss of heat which occurs at first 
 is not of much consequence. It is a 'wise precaution, in the case of baths to 
 
712 HYGIENE 
 
 be used by children, to have a movable key, or spanner, to the hot-water tap, 
 to be kept in chai-ge of the attendant, as otherwise accidents by scalding 
 may occur. In all schools, whether for boys or for girls, the children ought 
 to be taught to swim. At most schools some provision is now generally 
 made to effect this most desirable object. Where the school is near the sea 
 or on a suitable river, swimming therein is commonly practised in the summer 
 months AA-ith great advantage to the children. During the winter, the 
 children ought to have the opportunity of going to a public swimming bath, 
 where the Avater is kept at a suitable temperature — say about 70° Fahr. — 
 and this is done by arrangement in the case of many public and private 
 schools in the provinces. But at numerous Poor-law schools and other 
 similar institutions, swimming baths have been specially constructed for the 
 use of the children witli excellent results. One good bath, arranged so as to 
 be available by the children of either sex, is far better than a separate bath 
 of smaller size for each sex.^ Mr. Paget, however, urges that in the interest 
 of health, even where swimming baths are occasionally resorted to, the 
 practice of daily cold-water sponging should still be encouraged as much as 
 possible, and he adds that as physical health depends largely upon its being 
 carried out, no school should be called a healthy school which does not 
 provide some regular means for its accomplishment. 
 
 The next important point in connection with schools of the type under 
 consideration is that of closet accommodation, and with respect to this it may 
 at once be said that while the closets for night use must of necessity be 
 attached to the building and in near proximity to the dormitories, those for 
 general and day use ought to be wholly detached and out of doors. In the in- 
 terests of purity of air within the building, the closets attached to the building 
 must be arranged in the same way as is now universally required in the case 
 of the closets of hospitals — i.e. they must be placed in projections from the 
 building, provided with opposite external windows for the purpose of cross- 
 ventilation, and must further be separated from the interior of the building 
 by an intervening lobby, itself having independent cross-ventilation. What- 
 ever form of closet is adopted, whether on one of the systems of dry-earth or 
 on the water-closet system, it should be regarded as indispensable that this 
 arrangement should be carried out. The requisite amount of accommodation 
 in connection with the dormitories is never large, since, where the children 
 are in good health, they are not often resorted to at night, but one closet ought 
 at least to be readily accessible from each dormitory. The same projection 
 may usefully contain the slop sink and housemaid's sink where the chamber 
 utensils are emptied and thoroughly cleansed, for the slop sink, which receives 
 a quantity of excreta, ought to be treated in the same manner, as regards its 
 position and arrangement, as the water-closet. It is very desirable that the 
 use of chamber utensils in dormitories should be abolished as much as possible, 
 as the retention of them involves the exposure of a considerable surface, in 
 the aggregate, of urine, which must tend, by evaporation, to vitiate the 
 
 ' Mr. Ernest Turner, F.R.I.B.A., in his Eeport to the Social Economy Committee of 
 the Paris International Exhibition 1889 (British Section) on Public Baths and Wash- 
 houses, refers to a new system of heating the water at the baths of the Boyal Military 
 Academy at Woolwich, for which it is claimed that the whole of the heat generated is 
 used, and a uniform temperature ensured. With this, he adds, may be combined a system 
 of continuous forced circulation of the water through a purifying and aerating apparatus, 
 by means of which the purity of the water may be maintained for a considerable period 
 without great loss of heat. The cost of heating is thus reduced to a minimum, as cold 
 water need not be introduced in the baths so frequently, and the cost of raising its tem- 
 perature is avoided. The system is the invention of Mr. Charles H. Eosher, C.E., who has 
 been assisted in reference to the purification of the water by Mr. A. H. Hobson, F.R.M.S., F.C.S. 
 
THE DWELLING 
 
 ri3 
 
 ■atmospliere of tlie dormitory. In some schools for boys, nririals have Ijeen 
 provided in suitable projections from the staircases and the children en- 
 couraged to use them night and morning, thus admitting of a great reduction 
 in the number of chamber utensils in the dormitories. 
 
 For day use, out-door closets should be provided, and as these would 
 iDe the closets generally used by the children they should not be unduly 
 remote from the day and school rooms, nor should they be so placed that, in 
 going to and from them, the children would be much exposed to the weather. 
 It is indispensable that they should be well lighted after dark. This is 
 requisite not only on the score of cleanliness and morals, but in order that 
 the children may not shrink from going to them during the winter evenings. 
 The number of closets needed for a given number of children is another 
 point that calls for attention, since, if the number of closets is scanty, the 
 children may be led to neglect or to be irregular in the use of them, and 
 every effort should be made, in the interest of their health, to facilitate and 
 encourage regularity in this respect. The Education Department prescribe 
 the rate of closet accommodation as follows : 
 
 Number of children 
 
 Number of Closets 
 
 
 
 
 For Girls 
 
 Por Boys 
 
 Under 50 
 
 3 
 
 2 
 
 „ 70 
 
 4 
 
 2 
 
 „ 100 
 
 5 
 
 3 
 
 „ 150 
 
 6 
 
 3 
 
 „ 200 
 
 7 
 
 4 
 
 „ 300 
 
 8 
 
 5 
 
 and urinals in 
 proportion 
 
 But inasmuch as these numbers relate to day schools only, where it may be 
 expected that a large majority of the children will have obeyed the daily call 
 of nature before leaving home, it follows that a considerably higher rate 
 of closet accommodation is requisite at the residential school. The Local 
 Government Board have prescribed, for Poor-law schools, a rate of 10 closets 
 per cent, for boys and 15 per cent, for girls — urinals being requisite in 
 addition for the boys, and this would seem a proportion that may fairly be 
 applied to residential schools generally. 
 
 The precise kind of closet best adapted for children will depend much 
 upon the locality. If the institution is so situated that an ample supply 
 of water and a proper system of sewers are available there can hardly 
 be any question as to the advisability of adopting some kind of water- 
 closet ; on the other hand, where water supply and sewers are not avail- 
 able, the dry-earth system is undoubtedly the best. The privy in which 
 the excreta are covered or mingled with coal-ash is much used in 
 certain parts of the country, but in schools, where the consumption of 
 coal and production of ashes is necessarily very small in proportion to the 
 number of children using the privies, it is scarcely ever found to be a 
 satisfactory system, the contents of the receptacle beneath the privy seat 
 being generally in a wet and offensive condition. In country districts where 
 the dry-earth system is in use, it is generally possible to obtain an ample 
 quantity of suitable garden mould containing organic matter; with reason- 
 able attention on the part either of those using the closets, or better 
 ■still on the part of the school officers, who should take care that the proper 
 quantity of properly sifted dry earth is thrown . into the receptacle at 
 
7U HYGIENE 
 
 certain regular intervals every day, the system is an admirable one, and the- 
 contents of the receptacle may be retained undisturbed for a much longer 
 period than is permissible in the case of a coal-ash privy. But whenever 
 adopted it cannot be too strongly insisted upon that the necessary supervision, 
 attendance, and appliances for keeping the closets free from nuisance will be 
 regularly and duly supplied, otherwise the system cannot be expected to prove 
 satisfactory. 
 
 As regards the details of construction, it is necessary to keep the 
 receptacle, if fixed, wholly above the level of the ground adjacent, in order 
 to preclude the possibility of surface water finding its way into it and 
 rendering the contents unduly wet ; for it is of the utmost importance that 
 the contents of the receptacle should be kept as dry as possible. Where 
 the receptacle is movable, as in the case of tubs or pails, the regularity of 
 service and attention is not less important than in the case of the fixed recep- 
 tacle, but greater frc([uency of removal becomes necessary, as the receptacle, 
 being small for facility of manipulation, is sooner filled. Where water and 
 sewers are available, the best kind of closet for outdoor use is that known as 
 the trough closet, with a periodical automatic flush. These closets, when the 
 trough is made of glazed stoneware of a light colour, can hardly be surpassed 
 for cleanliness and suitability. 
 
 Every residential school ought to have a complete laundry of its own, so 
 as to avoid the necessity for sending the soiled linen away to be dealt with, 
 possibly in places that are already infected, or in which there are infected 
 persons or things. The laundry building should be at a distance from the 
 occupied school buildings, and ought to have a good drying ground, where 
 the linen could be exposed to light and air whenever the weather permits. 
 It ought also to have an efficient drying ap]Daratus for use when the weather 
 does not admit of the wet linen being dried out of doors ; likewise a well- 
 ventilated room for airing the finished linen after leaving the ironing and 
 manghng room. Near the laundry there should be a good dismfecting 
 chamber. Such a provision is an excellent precaution against the introduc- 
 tion of clothing and other articles suspected of infection. The best appa- 
 ratus for the purpose is that in which the articles to be disinfected can. 
 be submitted to steam at high pressure so as to penetrate to the innermost 
 parts of the article. There are two or three good kinds of disinfecting 
 apparatus, but a detailed account of the efficiency of several kinds will be 
 found in the official report (1885) on the subject by Dr. H. Franklin 
 Parsons, one of the IMedical Inspectors of the Local Government Board. 
 
 In separate Poor-law schools it is usual to include among the buildings a 
 block of probationary wards, where children on their first arrival can be kept 
 in some sort of quarantine until it has been ascertained that they are free 
 from disease. The necessity for such wards has been demonstrated over and 
 over again in the case of many complaints common to childhood and which 
 are not always obvious in their early stages ; but especially have such wards 
 been found necessary in regard to ophthalmia. This subject is, however,, 
 referred to later in connection with school sanatoria. 
 
 WORKHOUSES 
 
 The English workhouse is an institution which, since it first became a 
 necessity, has undergone at least as much change in arrangement, from ' a 
 health point of view, as have hospitals and prisons. The importance of these 
 Poor-law institutions is alone a sufficient reason for giving the subject special 
 consideration ; for in England and Wales there are some 650 unions and 
 
THE DWELLING 715 
 
 Poor-law authorities, each possessing one workhouse, and many of them 
 having several workhouses of one sort or another. In these are housed 
 about 200,000 ' paupers, and the amount annually expended upon these 
 buildings (irrespective of repairs), in altering and enlarging them and in 
 erecting new ones, is about 500,000/. The old parish poorhouse, in whicli, 
 under the direction of the overseers, the poor were formerly relieved, was 
 bad in every conceivable way, and the whole system of the relief of the 
 poor became so scandalous that, in 1834, Parliament passed the Poor-law 
 Amendment Act, which, with certain further amending Acts, has been in 
 operation ever since. Under that Act unions of parishes were formed and 
 Boards of Guardians of the Poor were constituted ; workhouses under respon- 
 sible paid officers were provided, and the arrangements for the relief of the. 
 destitute poor were made uniform for the whole of the country. With the 
 scanty knowledge that existed at that time in regard to all matters concern- 
 ing health, it is not surprising to find that these early workhouses were 
 exceedingly defective in their sanitary arrangements. 
 
 In a recent publication ^ upon the subject, some typical plans of the work- 
 houses as recommended by the first Poor-law Commissioners are given, from 
 which it will be seen that in one instance a workhouse for 500 inmates, upon 
 a square site of one acre of land, is arranged so that the various wards are 
 placed against the four boundary walls in such a way as to have no other 
 ventilation than is derivable from the windows and doors on the inner side 
 next the courtyard, and so that each inmate would have an average of only 
 131 cubic feet of space. In another plan, also for a workhouse for 500 
 inmates of all classes in the one building, the various wards certainly have 
 means of through ventilation, but the inmates were in some cases placed in 
 beds tier above tier, and in others two in a bed, while the amount of cubic 
 space for the sick was scarcely 300 feet, and for those who were not sick only 
 half that amount, and the closet arrangements within the building were, as 
 may be expected, very defective. What the precise results of these conditions 
 were it is difficult now to ascertain, but while it is probable that much sick- 
 ness that we now know to be preventable was caused, and that an excessive 
 mortality prevailed, it is obvious that the arrangements generally for the 
 treatment of the sick were extremely unsatisfactory. 
 
 Some improvement took place in the later arrangements, but they 
 were still very defective, and so serious had these conditions become 
 towards 1864, that in the following year the proprietors of the Lancet 
 newspaper started a commission of their own to inspect and report on 
 the general state of the Metropolitan Workhouse Infirmaries, and in an 
 introduction to the reports so made the Lancet said : ' The State hospitals 
 are in workhouse wards. They are closed against observation ; they pay 
 no heed to public opinion; they pay no toll to science. They con- 
 travene the rules of hygiene ; they are under the government of men pro- 
 foundly ignorant of hospital rules.' The reports which appeared in the 
 columns of that newspaper at intervals from the middle of 1865 to the early 
 part of 1866 led to the appointment of a special official inspection of the 
 workhouses by a medical inspector (Dr. Edward Smith, F.E.S.) and a lay 
 inspector (Mr. Henry B. Farnall, C.B.), whose joint report was duly presented 
 to Parliament. About the same time the Poor-law Board appointed a com- 
 mittee to inquire into, and report upon, the amount of cubic space that ought 
 to be provided for the several classes of workhouse inmates, and one of the 
 
 • In 1888. 
 
 2 Knight's Guide to the Arrangement and Construction of Workhouse Buildings, 
 London : Knight & Co., 1889. 
 
716 HYGIENE 
 
 results of tlie agitation that had taken place was the passing of Mr. Gathorne 
 Hardy's Act for amending the laws relating to the relief of the poor in the 
 metropolis, an Act which constituted the Metropolitan Asylums Board and 
 pro^^ded for the erection of separate hospitals and asylums for the reception 
 of the harmless imbeciles who had previously occupied so much space and 
 caused so much trouble in the workhouses, and also of paupers suffering 
 from any of the dangerous infectious fevers. 
 
 Public attention all this time was being directed towards sanitary 
 matters generally. The Royal Commission upon Barracks and Hospitals 
 had reported ; . the Herbert Hospital at Woolwich and the Chorlton Union 
 Hospital had been erected on the pavilion system ; and much activity 
 began to prevail in the improvement of workhouses generally through- 
 out the country. The Poor-law Board in 1868 issued a set of printed 
 rules entitled ' Points to be attended to in the Construction of Work- 
 house Buildings,' ^ in which the amount of space prescribed for each inmate 
 in the several classes was fixed generally in accordance with the recommenda- 
 tions of the Cubic Space Committee. Separate infirmaries, independent of 
 the workhouse of the unions to which they belonged, were erected in many 
 of the larger unions and parishes, and were placed under the superintendence 
 of competent medical men instead of as previously the medical staff being 
 subordmate to the master of the workhouse. Separate schools were provided 
 in the suburbs for the metropolitan pauper children, and likewise in connec- 
 tion with some of the large pro^'incial unions. It will thus be seen that, 
 while in the early workhouses the common arrangement was to place all 
 the inmates, whatever their number and condition, in one huge building, 
 under one roof, it is now the practice to provide separate buildings at least 
 for the inmates in health and for the sick ; while in the case of workhouses 
 for more than a certain number of inmates, a separate building is usually 
 provided for the children, unless they are wholly removed from the workhouse 
 to some distinct and separate school. The regulations and requirements of 
 the Local Government Board are very definite as to this subdivision of 
 building, special stress being laid upon the necessity for avoiding the aggre- 
 gation of large numbers of inmates in any single block. This important 
 requirement is to some extent met by the equally important requirements, 
 on administrative grounds, for the subdivision of classes, and accordingly a 
 complete workhouse for a large union will ordinarily comprise the following 
 distinct buildings : — 
 
 (a) Entrance building, including probation wards. 
 
 (b) Tramp wards. 
 
 (c) Main building for aged and able-bodied inmates in health. 
 
 (d) Imbecile wards. 
 
 (e) Children. 
 (/) Infirmary. 
 
 (g) Isolation sick wards. 
 
 But where the number of indoor poor is very large, some of these buildings 
 take the form of distinct institutions. This is specially the case in the 
 Metropohtan Poor-law district, where the children are provided for wholly in 
 suburban schools, the harmless imbeciles in suburban asylums, and the in- 
 fectious cases in special fever and small-pox hospitals. 
 
 The minimum amount of space prescribed for each pauper in the dormi- 
 tories of the several buildings above referred to is as follows : 
 
 ' Revised and reissued in 1891. 
 
THE DWELLING 
 
 in 
 
 Wall space 
 per bed 
 
 Floor space 
 
 Cubic space 
 
 Casual pauper, tramp or vagrant wards 
 
 Probation or receiving wards 
 
 Able-bodied and aged . 
 
 Very infirm (bed-ridden) 
 
 Women with infants . 
 
 Imbeciles .... 
 
 Children .... 
 
 Ordinary sick and syphilitic 
 
 Lying-in cases 
 
 Offensive cases 
 
 Sick children 
 
 In isolation wards 
 
 Lineal feet 
 3 
 
 4 
 5 
 5 
 5 
 3' 9" to 4 
 6 
 
 5 to 6 
 12 
 
 Square feet 
 27 
 40 
 36 
 50 
 50 
 50 
 36 
 60 
 80 
 80 
 60 
 144 
 
 In addition to the above, day-room space is requisite for certain classes, 
 such as the casual pauper, who may be detained for a short period and 
 whose sleeping accommodation may be in the form of a separate room or 
 cell having a floor area of 86 feet and 360 cubic feet of space ; also for the 
 adult in health at the rate of 15 square feet of floor- space ; for the imbecile 
 at the rate of 20 square feet cf area, and for children 10 square feet in addi- 
 tion to their school and class rooms and work rooms. For the sick, the re- 
 
 UNION WORKHOUSE 
 
 GATE5HE/\D or* TTNE" 
 
 Fig. 130. 
 
 quisite day-room space is to be calculated upon the supposition that haK the 
 patients are able to leave their sleeping-ward for various periods during the 
 day, and for each of such patients the day-room should afford 20 square 
 feet of space. It is right to observe that the prescribed amounts of space, espe- 
 cially in the sleeping wards, are generally the smallest that can properly be re- 
 garded as sufficient, and, indeed, they are only so prescribed on the supposition. 
 
718 HYGIENE 
 
 that the arrangements throughout for ventilation and warming are complete 
 and efficient. As minimum qiumtities of space, they are in practice often ex- 
 ceeded, aswould be the case,not only in times of prosperity, when the number of 
 indoor poor is low, but where, as is often the case, the wards are constructed of 
 greater width and height than the minimum dimensions prescribed in the regu- 
 lations. In the case of the large sick wards of the metropolitan, and some pro- 
 vincial, modern Poor-law infirmaries the cubic space is invariably greater than 
 the above amounts, since, while the amount of wall space is the same, the width 
 of the wards, instead of only 20 feet, the minimum width prescribed in the 
 regulations, is almost always 24 feet, and the height 12 feet, consequently an 
 amount of abotit 850 cubic feet is available for each patient ; this corre- 
 sponds with the amount recommended by the Cubic Space Committee, and 
 is the basis upon which the accommodation of these wards is calculated for 
 computing the annual grant received by the Boards of Guardians in the 
 London district out of the Metropolitan Common Poor Fund and the fmids 
 of the County Council of London under the Local Government Act, 1888. 
 In the latter case the requirement as regards the provision of day-room 
 space, as such, is dispensed with. As regards the hygienic arrangements of 
 workhouse hospitals and schools, it will suffice here to refer to the pages 
 relatmg to hospitals and schools generally; and as regards the other 
 buildings of a workhouse, the principles ordinarily applicable to hospitals 
 have to be followed. It will be seen from the annexed block-plan of the new 
 and complete workhouse for the Gateshead Union (fig. 130), built from designs 
 by Messrs. J. H. Morton, Newcombe, and Knowles, that what is known as 
 the pavilion principle has been adopted for all the principal buildings. This 
 institution affords accommodation for 916 inmates, classified as foDows : — 
 
 Main Building — Male Pemale 
 
 Aged and infirm ........ 92 66 
 
 Able bodied 32 62 
 
 Women with children ....... — 30 
 
 Married couples 12 12 
 
 Schools — 
 
 Boys and gii'ls 120 120 
 
 Infants 30 30 
 
 Infirmary — 
 
 Imbeciles 25 25 
 
 Ordinary sick . . ' 66 66 
 
 Offensive cases 10 10 
 
 Itch and venereal 16 16 
 
 Lying-in cases — 10 
 
 Isolation wards 3 3 
 
 Entrance building — 
 
 Eeceiving wards 8 8 
 
 Vagrants 36 8 
 
 HOSPITALS 
 
 In considering the conditions that go to make a hospital healthy or the 
 reverse, the peculiar circumstances attending the aggregation of a large 
 number of sick or wounded persons under one roof need to be carefully borne 
 in mind. 
 
 Hospitals, as charitable institutions, exist for the purpose of affording 
 medical and surgical aid to the sick poor, and for economical reasons it is 
 essential that a considerable number of patients should be treated together in 
 one institution. Further, for economy of construction and nursing, it is 
 necessary that the patients should be grouped together in general wards. 
 
TEE DWELLING 719 
 
 It is not, however, necessary for the benefit of the patient that he should 
 form one of a group of some twenty patients in a ward, or of some four or 
 five hundred patients in a liospital. On the contrary, it is distinctly an 
 •element of danger to the individual patient that he is one of a large number 
 of diseased persons brought together under one roof. 
 
 Diseases arise de novo within the wards of a hospital, which are clearly 
 traceable to direct contamination of air by wound surfaces, and are known 
 as ' traumatic ; ' and the enormous sacrifice of life to the various forms of 
 septic disease which took place in hospitals in former days, notably in the old 
 Hotel Dieu at Paris, shows very clearly the extent of the danger incurred 
 from this cause. 
 
 The aggregation, therefore, of large numbers of diseased persons under 
 one roof can only be justified if it can be shown that the advantages arising 
 therefrom more than counterbalance the risks incurred. The advantages 
 are twofold: 1st, to the patient, in that the highest possible skill in medicine, 
 in surgery, as well as in nursing, is freely at his disposal, and that everything 
 that science can suggest will be applied to restore him to health ; and 2ndly, 
 to society at large, in the incalculable value of the material for study and 
 teaching presented in the wards of a large hospital. 
 
 The important factor, then, in hospital hygiene is that a hospital is a 
 hnilding which is perpetually producing within itself the elements of danger 
 to its own inmates ; ' an establishment which never rests from fouling itself ; 
 nor are there any products of its foulness —not even the least odorous of 
 such products — which ought not to be regarded as poisonous ' (Simon, ' Sixth 
 Eeport of the Medical Officer of the Privy Council,' 1864). 
 
 The air of a hospital, then, is liable to contamination from the following 
 causes :— 
 
 , 1. The emanations or effluvia from the bodies and excretions of the 
 patients. 
 
 2. The presence of suppurating wounds, with their necessary dressings, 
 poultices, &c. 
 
 3. Foul linen, bedclothes, &c. 
 
 The foregoing are necessary and unavoidable conditions common to all 
 hospitals. 
 
 These conditions are aggravated, and their power for evil intensified by — 
 
 (a) Insufficiency of cubic space. 
 
 (&) Inefficient ventilation. 
 
 (c) Improper arrangements for the removal of excreta, dressings, poul- 
 tices, soiled linen, &c. 
 
 {d) Faulty arrangement of buildings. 
 
 The neglect of proper measures of hygiene produces in a surgical ward 
 the class of diseases known as ' septic ' — e.g. erysipelas, pyaemia, septicaemia, 
 &c., and, as it will be seen, it has happened over and over again that a 
 hospital has become so saturated with the septic poison of recurrent out- 
 breaks of disease that nothing short of total destruction has availed to stamp 
 out the mischief. 
 
 In fever hospitals it has long been known that overcrowding in the wards 
 is productive of the worst possible results, and that the roughest sort of 
 shelter which admits of a copious through current of air is better than a 
 permanent structure withouit adequate means of ventilation. 
 
 No more striking example of defects of construction and administration 
 ■can perhaps be given than the old Hotel Dieu of Paris. This remarkable 
 structure occupied a site close to the Cathedral of Notre Dame, and extending 
 to both sides of the river, the two parts being connected by two bridges, one 
 
720 HYGIENE 
 
 of which was in fact a ward. Writing in the year 1788, Tenon puts the 
 total number of patients at 3,-il8, of whom 2,627 were in the buildings on 
 the south side of the river. In this vast building, which was nothing more 
 than one huge ward — so intimate was the intercommunication between the 
 various parts —were assembled patients with fevers, small-pox, skin diseases, 
 lying-in women, and surgical patients. ' In the middle are placed the most 
 infectious departments, such as clothes stores, mortuaries, dissecting rooms ; 
 they [e.g. the patients] are contained in four or five floors of wards joined 
 together and without ventilation, wards surrounded by rooms for the staff, 
 which cool and shade them ; where the staircases are insufficient ; where 
 the sole and only promenade is a place encumbered with drying grounds and 
 linen in course of evaporation ; a monstrous pile more fit to prolong sickness, 
 to destroy than to re-establish and preserve health ' (Tenon, ' Memoire sur 
 les Hopitaux de Paris,' 1788). 
 
 The same authority gives the total number of beds provided for these 
 8,418 patients as 1,219, of which number 733 were ' grands lits,' and held 
 six patients each ! The remainder were single beds. 
 
 The condition of the latrines is described by the same author as mere 
 masses of ordure : the latrines were wholly inadei^uate in point of numbers, 
 and Avere in the closest proximity to the wards. The extent to which in- 
 fection must penetrate into the wards is, says M. Tenon, inexpressible. 
 
 The immediate result of this state of things was, that one patient in 
 every four and a half died, without reckoning the deaths of children born in 
 the hospital and transferred to the ' Enfants Trouvcs.' 
 
 The buildings of the Hotel Dieu were to a large extent of great age, 
 some portions dating back certaualy to the fifteenth century, some possibly 
 older still. They had been added to and enlarged from time to time without 
 much definite plan, except to increase the number of beds ; and the disasters 
 consequent upon the inherent defects of the structure were intensified by 
 overcrowding. 
 
 Of the conditions which have been referred to as aggravating the hurtful 
 influences inseparable from a hospital ward, insufficiency of cubic space and 
 inefficient ventilation are closely allied, and may be taken the one as the 
 complement of the other. Cubic space, indeed, is of little value in itself 
 unless it is accompanied by ample means of ventilation. The importance of 
 this has received striking illustration on many occasions, notably during 
 the Franco-Prussian War, when it happened that a church and a slaughter- 
 house m Paris were about the same time turned into hospital wards for 
 wounded soldiers. In the church gangrene broke out and the mortality 
 amongst the men was very heavy. In the slaughter-house no septic disease 
 at all appeared, and the men all made good recoveries. And this happened 
 notwithstanding that the cubic space per man in the church was greater than 
 in the slaughter-house. The essential point of difference in the two buildings 
 was this. The slaughter-house was a mere shed, with the sides of louvre 
 boards, and the men therefore were practically in the open air ; whilst in the 
 church the walls were of solid masonry, and the windows narrow, and with 
 but few openings. 
 
 This experience is also amply borne out by that of the hut hospitals in 
 the field during the same war. These huts were built of rough boarding, 
 and of so light construction that the wind blew freely through them. Never- 
 theless, there was an almost complete absence of septic disease, while in the 
 permanent hospitals, or the houses temporarily converted to the purpose, 
 hospital diseases were of frequent occurrence. 
 
 Instances could be multiplied to any extent of the value of pure air to 
 surgical patients ; and the same remark applies equally to fever patients. 
 
THE DWELLING 721 
 
 During an epidemic of typhus fever in Paris in 1814 the patients in the 
 Abattoir of Montfaucon, situated in one of the highest parts of Paris, fared 
 much better than those in the regular hospitals (Parkes). In the Irish fever 
 of 1847-48 cases treated in the open air and in sheds made better recoveries 
 than those in the permanent buildings (ibid.). 
 
 A notable instance of the mischief caused by the want of efficient ventila- 
 tion is that of the York County Hospital. This building was designed to be 
 warmed and ventilated entirely by mechanical means. There were no fire- 
 places and the windows were all fixed and were in some cases double. The 
 air after being warmed by passing over hot pipes in the basement was driven 
 into the wards by an engine, and the foul air was drawn out of the wards 
 by heated shafts. This system remained in operation for nine years, by 
 which time the persistent ill health of the patients, and particularly the 
 constant occurrence of erysipelas after the slightest incisions, induced the au- 
 thorities to abandon the artificial system and resort to open windows and fire- 
 places, and upon this being done erysipelas disappeared and the cases did well. 
 
 Improper arrangements for the removal of excreta &c. have been largely 
 responsible for ill effects in hospitals. The evil effects of bad drainage were 
 clearly recognised by Howard ; amongst other things he recommends bring- 
 ing a ' fine stream of water ' to flush the drains at the Military Hospital, 
 Dublin, and he notes with approval the method adopted at the Royal 
 Hospital at Plymouth of flushing the drains by means of a tank holding 180 
 tons of water. 
 
 The necessity for the speedy removal of all f^cal matter from the proxi- 
 mity to any dwelling is doubly great in the case of a hospital ward, where 
 perforce excretions are voided in the ward by patients unable to leave their 
 beds, and where also the closets must be in close communication with the 
 ward. In former days the readiest mode of making a water-closet was to cut 
 off a small part of the ward by means of a boarded partition and within the 
 space so enclosed to fix the apparatus. Except for decency's sake, the ap- 
 paratus might just as well have been fixed in the centre of the ward. It is 
 by no means the rule, even at the present day, to find the water-closets sepa- 
 rated from the ward by more than a door or at least two doors ; and the 
 necessity for more effectual separation between the ward and the closet than 
 is afforded by a door is not so invariably recognised abroad as it is in this 
 country. In the late Mr. Netten Radcliffe's ' Report on the Sanitary Condi- 
 tion of the Manchester Royal Infirmary ' (' Sixth Annual Report of tlae Local 
 Government Board,' Supplement containing Report of the Medical Officer) he 
 attributes the insanitary state of the hospital partly to the faulty arrange- 
 ment of the water-closets. ' Few facts,' he says, ' are perhaps more clearly 
 established in medicine than the mischievous influence of an atmosphere 
 pervaded with sewer air in surgical wards. Now the water-closets, the baths, 
 the ward offices, and the drains of the infirmary generally being placed within 
 the building, several of the closets without even direct communication with 
 the outer air, sewer air escaping from them must necessarily pass into the 
 corridors and wards.' That the sewer air did actually make its way into the 
 building, owing to the faulty construction of the drains, is clearly shown in 
 a subsequent part of the report. The same writer found badly constructed 
 drainage playing its part in the promotion of insanitary conditions at the 
 Radcliffe Infirmary, Oxford [op. cit. Appendix, No. 6). 
 
 Besides the removal of faecal and waste matters by means of drains there 
 are the soiled linen, poultices, dressings, &c., of the patients, aU of which 
 are more or less infective and contain organic impurities which need to be 
 quickly removed and destroyed. There is also the ordinary refuse (dust, 
 
 VOL. I. 8 A 
 
722 HYGIENE 
 
 kitclien refuse, and so forth) wliicli has to be disposed of. The accumulation 
 of refuse matter in close proximity to the wards is an arrangement which 
 involves very great danger to the inmates of the ward. In the report on 
 the Eadcliffe Infirmary, just referred to, Mr. Eadclifl'e notes the close con- 
 tiguity of the laundry to the accident ward, and the practice of screening 
 ashes and refuse immediately under the windows of the same ward as distinct 
 elements in the causation of erysipelas in that ward. 
 
 Lastly, the inherent dangers of hospital life may be aggravated by im- 
 proper arrangement of buildings. 
 
 The defects of planning are many; the most important are the close 
 juxtaposition bi blocks of several storeys shutting out the sun and preventing 
 the free circulation of air ; buildings in which the wards are so intimately 
 connected that all the patients are practically in one and the same atmosphere ; 
 and buildings where there is direct atmospheric communication between the 
 wards and the mortuary, out-patient department, or laundry. Years ago 
 Miss Nightingale pointed out the defects of plans such as those of the Necker 
 Hospital, Paris, and the Royal Free Hospital, London, in which a small 
 courtyard is surrounded with high buildings on every side, impeding free circu- 
 lation of air ; of wards wherein the beds were placed along dead Avails with 
 windows only at the extreme ends, such as existed at the former Clinique de 
 la Maternite, Paris ; of Netley Hospital, and the Royal Hospital, Portsmouth ; 
 of wards such as those in the Old Marine Hospital, Woolwich, where there 
 was ' no provision for ventilation worthy of the name, and the wards are so 
 arranged that the sick must of necessity be supphed with common foul air.' 
 (' Notes on Hospitals,' 3rd ed.) 
 
 The conclusions arrived at by Messrs. Bristowe and Holmes in the 
 ' Report on Hospitals,' already referred to,^ were by no means in favour of pavi- 
 lion hospitals as opposed to the older type of plan ; but it must be remembered 
 that almost the only example of pavilion hospitals then in existence was the 
 Lariboisiere at Paris, in which the advantages of the paA^ilion system are to 
 so large an extent neutralised by the great height of the buildings on the 
 corridors. Strongly biassed as these eminent authorities undoubtedly were 
 in favour of the older form of hospital plans, they yet unhesitatingly condemned 
 the arrangement of a number of small wards on both sides of long corridors. 
 Of this latter type the Manchester Royal Infirmary is an example, and its 
 history unmistakably illustrates the evils incident to such a plan. 
 
 Professor Erichsen also condemns emphatically what he calls the ' big- 
 house ' plan, in which are ' basements containing kitchens, sculleries, cellars, 
 and the ordinary offices of a large establishment ; with an operating theatre 
 and dead-house more or less closely connected with the main building ; 
 with every floor filled with sick and injured people.' ( ' Hospitalism,' by John 
 Eric Erichsen, F.R.S., 1874.) 
 
 Enough has been said of the evils liable to arise in consequence of faulty 
 construction ; it now remains to consider what are the conditions necessary 
 to be observed in the planning and construction of hospitals in order to insure 
 that, so far as the structure is concerned, the patients shall be treated under 
 circumstances most favourable to their recovery. 
 
 The term ' hospital ' includes a great variety of institutions having for their 
 object the treatment and cure of the sick. These institutions maybe divided 
 into two main sections of general hospitals and special hospitals. 
 
 The class ' general hospitals ' will include all the hospitals which receive 
 all sorts of medical and surgical diseases except infectious fevers and chronic 
 
 ' Sixth Eeport of Medical Officer, Privy Council. (See p. 719, ante.) 
 
THE DWELLING 723 
 
 incurable and mental diseases. It will also include the large and increasing 
 class of buildings called cottage hospitals and the infirmaries built and 
 administered under the Poor-law system. 
 
 Special hospitals include fever and small-pox, lying-in, consumption, 
 children, incurable and chronic, convalescent, mineral water and sea bathing, 
 eye, ear and throat, cancer, skin. 
 
 Into the question of the raison cVetre of special hospitals it is not desirable 
 in the present work to enter ; the question is a complex one and belongs 
 more to the region of medical ethics than to that of hygiene. This much 
 may be said, however, that of the necessity for special hospitals for fever and 
 small-pox, and for convalescents, no reasonable doubt exists, whilst very 
 strong reasons exist for special hospitals for children, incurables, and perhaps 
 phthisis. From the point of view of hygiene the hospitals which need 
 special consideration are those of the infectious class, and hospitals for con- 
 sumption, children, and convalescents. The rest are governed by the general 
 principles of hygiene applicable to all hospitals, and need not here be sepa- 
 rately considered. 
 
 I. General Hospitals 
 
 Site. — ' An ideal site for a hospital,' says Dr. Mouat, ' would be one where 
 the conditions of soil, subsoil, drainage, water supply, and all surroundings 
 were most free from local causes of impurity, and where there were fewest 
 buildings and habitations to exclude or intercept air and light, or to be them- 
 selves active agents in the creation of causes of unhealthiness, such as factories, 
 workshops, &c.' (' Hospital Construction and Arrangement,' Part I.) Such 
 conditions are not always easily to be fulfilled when the hospital in question 
 happens to be one in a large town, or if fulfilled in the beginning are apt to 
 'be greatly modified with the lapse of time and the growth of population. 
 In London, the Middlesex and St. George's Hospitals are cases in point. 
 When first established, in the first half of last century, both these institutions 
 were in the outskirts of London as it then was, with open fields all round 
 them. Now, though St. George's Hospital has the advantage of being close 
 to two large parks, Ijondon has grown around and beyond both of them, until 
 the outskirts are miles away. 
 
 A general hospital, again, must always be placed within a reasonable 
 distance of the population whose needs it has to serve, so that in fixmg upon 
 the site for a hospital in a large manufacturing town regard must be had 
 to the distance which patients would have to travel from the centres of 
 industry, where accidents would be likely to occur. The importance of a 
 free air space round about a hospital is very great, and a site completely shut 
 in by high buildings is undoubtedly an unsuitable one. Dr. Mouat, in the 
 work quoted, recommends a zone of aeration in extent equal to at least 
 double the height of the buildings surrounding it ; and modern practice on 
 the Continent tends not only to confirm, but to go beyond this Hmit. The 
 following table, extracted partly from a paper in the ' Practitioner ' (' Notes on 
 Modern Hospital Construction,' by P. Gordon Smith, June, 1888), illustrates 
 the importance attached by authorities abroad to large site area per bed : — 
 
 Approximate area of 
 site per bed. 
 Germany : Feet 
 
 Friedrichshain, Berlin 1,713 
 
 Tempelhof (military) 1,308 
 
 Moabit 1,144 
 
 University, Halle 1,575 
 
 University, Heidelberg 1,070 
 
 3 a2 
 
724 HYGIENE 
 
 Approsiinate area of 
 site per bed. 
 
 France : Feet 
 
 Bourges (military) l.GOO 
 
 St. Eloi, Montpelier 1,615 
 
 St. Denis 1,685 
 
 Belgium : 
 
 Antwerp 1,126 
 
 United fcJtates : 
 
 Johns Hopkins, Baltimore 1,679 
 
 England : 
 
 &t. Thomas's, London 660 
 
 Great Northern Central 293 
 
 Middlesex 273 
 
 St. George's 166 
 
 In several of the hospitals in the foregoing list the very large proportion 
 of site area to bed is due to the fact that the ward pavilions are all limited 
 to one storey ; a mode of construction that has not found very much favour 
 in England, and owing to the great value of land is scarcely ever likely to 
 be adopted in London or the larger provincial towns. 
 
 Where it is possible to exercise discretion in the choice of a site, regard 
 should be had to the following conditions : The site should be sheltered from 
 the prevailing rainy winds of the district, and, if such exist, from unhealthy 
 winds also ; a gentle slope is usually preferable to flat ground, and the side 
 of a hill to the bottom of a valley. Undrained clay soils, or thin strata of 
 gravel overlying clay, are both soils of an undesirable nature. 
 
 General Arrangement. — The disposition of the several parts of a hospital 
 in relation to each other necessarily depends greatly on the size of the hospital 
 and on the form and area of the site. But the important aim to be kept in 
 view is the efl'ective separation of the wards from the other parts with due 
 regard to economy of construction. The pavihon system was undoubtedly 
 a step in advance on the old ' big house ' plan ; but in its inception it was 
 regarded entirely as a means of obtaining more efl'ective ventilation to the 
 wards, and had no reference to the separation of parts. It is, indeed, no 
 uncommon thing to find a large pavilion hospital, of comparatively modern 
 date, the lowest floor of one pavilion occupied by the laundry, while in 
 another is found the out-patient department. Even the mortuary and jjost- 
 viortem room are not infrequently to be found occupying a portion of the 
 lowest floor of a ward block. 
 
 In order to arrive at some general principles of planning, it is necessary 
 to consider what are the essential parts of a general hospital. 
 
 In every hospital of whatever size there must always be — 
 
 (a) Administration oflices. These comprise the official rooms, i.e. board 
 room, secretary's oflice, steward's office, &c. ; the domestic offices, i.e. 
 kitchens, larders, sculleries, storerooms, and the sleeping accommodation 
 for resident staff and servants. 
 
 (b) Wards and their oiflces. 
 
 (c) Operation room, or theatre, with subsidiary rooms attached. 
 {d) Out-patient department. 
 
 (e) Mortuary dind j^ost-mortem room. 
 
 To these will be added in the case of very large hospitals — 
 
 (/) Laundry. 
 
 [g) Medical school. 
 
 {h) Nursing home. 
 
 In several recent examples of hospitals abroad each one of the depart - 
 
THE DWELLING 725 
 
 ments lias been placed in an absolutely separate and distinct building, in 
 some cases unconnected by even covered ways. At Heidelberg, for example, 
 the University Hospital consists of sixteen distinct buildings, five of which 
 are devoted to surgical patients, one to eye patients, four to medical cases, 
 and one to skin cases ; the rest comprising the administration block, patho- 
 logical institute, mortuary, kitchen, and laundry. The ward pavilions are 
 connected together by covered ways, consisting merely of roofs supported on 
 posts, and quite open at the sides. 
 
 Very similar to the last is the Hopital de I'lsle, or Insel Spittal, at Berne ; 
 but here there are no covered communications. 
 
 At the Johns Hopkins Hospital, Baltimore, the various buildings are all 
 •detached, and there are no connecting corridors. 
 
 The drawbacks to this mode of arrangement are : (1) the great extent 
 of land necessarily occupied ; (2) the greater proportional cost involved both 
 for land and buildings ; and (3) the increase in cost of administering such a 
 huilding consequent upon the greater distances between the various parts. 
 
 The really essential parts of such a building may be summed up as 
 follows : (1) separation, or at any rate avoidance, of intimate connection 
 hetween the wards and the administration block ; (2) separation of medical 
 from surgical wards ; (3) absolute atmospheric disconnection between the 
 wards on the one hand, and the mortuary, laundry, and out-patient de- 
 partment on the other. 
 
 To fulfil these conditions by arranging a series of one or two storey 
 buildings on a plot of ground of such ample dimensions as that of either of 
 the three hospitals mentioned is simple enough, but in London and in large 
 towns where land is of great value such a plan becomes a practical impos- 
 sibility, unless, indeed, it is contended that the beneficial results to the 
 patients are of such value as to justify the enormously increased cost. 
 
 That the essential parts of the system can be obtained without so lavish 
 an extent of land being required is evidenced by the plan (fig. 131) of the 
 new Great Northern Central Hospital, London. This hospital occupies a 
 site of less than a third in extent of that at Heidelberg. Nevertheless, it 
 will be seen from the plan that the wards are practically isolated from each 
 other and from the rest of the hospital ; that the operation room is, though 
 in easy communication, not in direct atmospheric connection with the wards ; 
 that the mortuary and the out-patient departments are distinct and separate 
 buildings. 
 
 So far, then, the essential principles of the separation of parts are com- 
 plied with in this plan with a comparatively small area of site per patient. 
 
 The value of a sufficiency of open space about a hospital is undoubtedly 
 very great ; but in cases where the cost of land is so great as it is in London 
 and some provincial towns the absolute necessity for so large an area of site 
 per bed may reasonably be questioned. And although the proportion of site 
 to patients at the Great Northern Central Hospital is by no means what it 
 might be without undue extravagance, yet it must be admitted that even on 
 this restricted site it has been possible to obtain the essential conditions of 
 separation of parts. 
 
 Administration Block. — The general arrangements of this part of a 
 hospital will necessarily vary with the size of the hospital. In a large building 
 the offices will be numerous and the residential part extensive ; but the modern 
 custom of housing the nursing staff in a separate building very much reduces 
 the amount of accommodation to be provided in the main administration 
 block. In some modern hospitals also the kitchen offices, with the dormi- 
 tories for servants, are placed in a separate block, thus stiU further reducing 
 
726 
 
 HYGIENE 
 
 the main block. In the majority of English hospitals the administration 
 block comprises the secretary's office or offices, boardroom, residences for 
 
 CREflT NORTHERN CENTRAL hOSPlT/IL 
 tiOLLOWftY ROHO 
 LONDON J\t. 
 
 knuof 
 
 NUET VtKTlLATOM 
 
 MOLLOWAV ROAD 
 
 Fig. 131. 
 
 medical staff, matron and secretary, steTvard's office, storerooms, kitchen 
 offices, and servants' dormitories. To these should be added an office for the 
 matron, and a consultation room for the visiting staff. The kitchen offices 
 
THE DWELLING 727 
 
 should be placed on the top floor, and the stores in the basement, with com- 
 munication between the two by means of a lift and speaking-tube. Separate 
 dining-rooms mvist also be provided for the male and female servants. 
 
 Wards. — It is now pretty generally agreed that the pavilion type of ward is 
 the most suitable one for general hospitals, but the precise form of the ward 
 admits of variations. The most general form is that of a rectangle varying 
 from 20 to 30 ft. in width, and from 30 to over 100 ft. in length. Two other 
 forms exist — one the circular, the other octagonal. The circular form has 
 been adopted in several instances, and its merits will be discussed later ; of 
 the octagonal form only one example exists, that at the Johns Hopkins 
 Hospital, Baltimore. 
 
 The dimensions of a ward are governed by two conditions: (1) the 
 number of patients to be associated together, and (2) the cubic space and 
 floor area to be allotted to each patient. It is impossible to lay down any 
 hard-and-fast rules for the number of patients to be put into one ward. 
 Consideration of nursing economy points to large wards. Consideration of 
 hospital hygiene points equally to small wards. From the former point of 
 view a convenient number for a ward is thirty-two, which number will be 
 found at Lariboisiere, the Herbert Hospital, and Leeds Infirmary. On the 
 other hand, at the newest hospitals on the Continent the average number in 
 a ward will be found to be about sixteen. There can be no doubt that, 
 especially for surgical wards, the smaller the number of patients associated 
 together the better. A large number of small wards gives greater facilities 
 for classification of cases than a small number of large wards. The question 
 is, however, very largely one of cost, and it cannot at present be said with 
 absolute certainty that the gain to the patients in small wards more than 
 outweighs the additional outlay involved. 
 
 Having determined the number of beds in each ward, it is necessary to 
 provide that each patient shall have sufficient space both of floor and of air. 
 What constitutes ' sufficient ' space depends upon the question of ventila- 
 tion. And by ventilation is meant such a change of air to each patient as 
 will secure to him a constant supply of the purest available air without 
 draught, and at a proper temperature. This supply should, according to the 
 best authorities, be practically unlimited, or perhaps it would be more correct 
 to say that it should be capable of unlimited increase when occasion demands. 
 The figures for floor space and cubic space in general hospitals considered 
 necessary by Drs. Parkes and De Chaumont are 100 to 120 ft., and 1,500 to 
 2,000 ft. respectively. General Morin gives 60 to 70 cubic metres (2118'6 
 to 2471'7 ft.). The Paris hospitals have a mean of 43 cubic metres 
 (1518'33 ft.), while the London hospitals, according to the same authority, 
 average 52 metres (1826"12 ft.) per bed. The latter figure is misleading, 
 inasmuch as some of the large hospitals (Middlesex, St. George's, St. Mary's, 
 Westminster) are entirely omitted from the list upon which the average 
 is made. 
 
 As a practical deduction from these and like facts, it will be found that 
 100 square feet is the minimum floor space in general wards, and that this 
 amount should be increased for acute surgical cases and for clinical wards. 
 
 In the latter case space is required for the students who gather round 
 the beds for clinical instruction. At the Edinburgh Eoyal Infirmary — one of 
 the largest medieal schools in the United Kingdom — the floor space is 149 feet 
 per bed, and at Halle — also a large teaching centre — it is 140 feet ; on the 
 other hand, the floor space at the Johns Hopkins Hospital, on the planning of 
 which an immense amount of thought and care has been bestowed, is only 
 105 feet. 
 
728 . HYGIENE 
 
 With regard to cubic space, 1,500 feet should certainly be taken as the 
 minimum for acute cases, though for wards in which a proportion of mild or 
 convalescent cases are mixed with others of an acute nature the cubic space 
 may with safety be as low as 1,200 feet.' In certain cases 2,000 feet will not 
 be found excessive ; and in some instances, as at Edinburgh Royal Infirmary,''' 
 Antwerp,^ Heidelberg,^ Halle ^ (surgical wards). Hotel Dieu (Paris),*^ St. 
 -Denis,^ Bichat,** St. Eloi,^ Genoa,'° this amount is largely exceeded. 
 
 The requisite amount of cubic space must, however, to a large extent depend 
 upon the means of ventilation adopted ; and it may safely be said that with 
 our English habits of constantly open windows and open fireplaces a less 
 amount of cubic space is permissible than when the mechanical means of 
 ventilation so largely prevalent abroad are adopted. 
 
 It will thus be seen that no hard-and-fast rules can be laid down either 
 for floor area or cubic space per patient, but that the amounts to be provided 
 must be dependent on circumstances. 
 
 The particular form which a ward should take may either be rectangular, 
 circular, or octagonal. 
 
 The rectangle is the most familiar form, and being most simple in con- 
 struction has been until quite recently universal. The idea of a circular 
 ward owes its origin in this country to the late Professor Marshall, F.R.S., 
 who in 1878 suggested its adoption in a paper read by him at the Social 
 Science Congress of that year'' and subsequently published. Curiously 
 enough, the same idea had about the same time occurred to a Belgian 
 architect, M. Baeckelmans, who in 1872 submitted plans for a new civil 
 hospital at Antwerp, which were with some modifications subsequently 
 carried out. 
 
 Professor Marshall's advocacy of the circular form was based on (a) free- 
 dom of frontage to all points of the compass, (h) great accessibility to light 
 and air, (c) greater area contained within a given length of wall in a circle 
 than in a rectangle, {d) superior ventilability, and (e) more equal warmmg. 
 He also considers that a circular ward can be better administered and would 
 present a more cheerful and agreeable appearance than a long straight ward. 
 The opponents of the system asserted on the other hand that a circular ward 
 would be dark or inadequately lighted, that it would be difficult of super- 
 vision, that the patients would be uncomfortably in vieAV of each other, that 
 the ventilation would be difficult if not impracticable, and finally that the 
 construction would be excessively costly. 
 
 While it is not yet possible to speak positively on the relative advantages 
 of circular and rectangular wards, it is certain that the objections cited above 
 have in practice been entirely disproved. In all the circular wards yet erected 
 the question of lighting, ventilation, and supervision have been dealt with 
 most efficiently, and no complaint has ever yet been made by the patients of 
 any discomfort arising from the form of the ward. 
 
 The objections on the score of cost have been entirely based upon a 
 fallacious system of argument, which presumed that no ward should ever 
 hold less than twenty- eight patients. It is easy to show that the circular 
 form is extravagant and indeed impracticable when the number of patients 
 
 ' Le Fort, Note stir qiiclq^ues imnts clc Vhyrjiena hosjntalierc en France eten Angleterre, 
 1862. 
 
 - 2,015 to 2,039 ft. ^ 2,525 ft. •* 2,050 ft. =• 2,207 ft. 
 
 « 2,222 to 2,411 ft. ' 2,457 ft. « 2,205 ft. " 2,328 ft. 
 
 '» 2,644 ft. 
 
 " On Circular System of Hospital Wards. By John Marshall, F.B.S. With remarks 
 and illustrations by Percival Gordon Smith. London, 1878. 
 
THE DWELLING 
 
 729 
 
 Fig. 132. 
 
 in a ward passes a certain limit ; but it is a reductio ad absurdum to first 
 fix the limit at an impossible number and then condemn the system on 
 that ground alone. Doubtless the construction of a circular building is 
 more costly than that of a rectangular one, the conditions of each being 
 identical except as to form ; but judging from the very few examples that 
 have yet been erected it may safely be said that the difference in cost 
 need not exceed about two per cent. It is curious to note that the opposition 
 to the circular system has emanated almost entirely from architects and not 
 from medical men. 
 
 Circular wards exist at the following hospitals : Antwerp (Civil Hospital), 
 Greenwich (Miller Memorial), Hastings, Burnley (Victoria Hospital), Liverpool 
 (Eoyal Infirmary), Milton near Gravesend (Military), Seaforth near Liverpool 
 (Military), New York (Cancer), and the Workhouse Infirmary, Hampstead. 
 The rectangular 
 
 pavilion ward is of two 
 
 forms : (1) the double 
 
 ward (fig. 132), which 
 
 consists of two ordinary 
 
 wards placed side by 
 
 side, with the dividing 
 
 wall pierced at inter- 
 vals with arches, and 
 
 having four rows of 
 
 beds between the two 
 
 external walls : ex- 
 amples of this ward 
 
 may be seen at St. 
 
 Bartholomew's, the 
 
 London Hospital, Guy's Hospital, and the London Fever Hospital ; in a 
 
 modified form at King's College Hospital and in some Poor-law infirmaries. 
 
 (2) The ordinary single ward (fig. 133), which is varied only in size and in 
 
 the arrangement of the 
 
 beds. The latter are either 
 
 placed in pairs, against 
 
 the piers dividing the win- 
 dows, as at St. Thomas's, 
 
 London, Tenon Hospital, 
 
 and the Hotel Dieu, Paris ; 
 
 or singly, having a win- 
 dow intervening between 
 
 each bed and the next. The 
 
 latter arrangement is much 
 
 to be preferred, as it more 
 
 effectually isolates each 
 
 patient from his neighbours, 
 
 and permits of equal spac- 
 ing of the beds. No bed 
 
 ought to be nearer to the 
 
 next one than five feet ; then 
 
 each patient will have a minimum of eight feet clear wall space. In large 
 
 wards for acute cases, this space ought to be increased to ten feet. 
 
 From what has been said it will be seen that award should have two rows 
 
 of beds, and that between each bed and the next there should be a window. 
 
 As usually arranged, this would give in a ward for, say, twenty beds eighteen 
 
 Fig. 133. 
 
730 HYGIENE 
 
 windows, nine on each wall. Therefore, at each end of the ward there would 
 be two beds with a window at one side only. The practical result is that the 
 space occupied by these end beds is not so well ventilated as the rest of the 
 ward, and it has been often observed that the cases treated in them do not 
 fare so well as those in the remainder. The remedy for this is to place 
 an additional window between the end of the ward and the end bed on each 
 side, increasing if necessary the length of the ward in order to do so, and 
 giving the extra length entirely to the end beds. Thus, in a ward of twenty 
 beds there should be twenty-two windows instead of eighteen. These end 
 windows need not be as wide as the other windows, but may be just sutii- 
 ciently wide to obtain the necessary movement of air. 
 
 There is no better form of window for a ward than the ordinary double- 
 hung sliding sash with a hopper light above. The glass line should be 
 sufficiently low to allow the patients to see out of window without standing 
 up, and the top of the window should be as near the ceiling line as it is 
 possible to get it. The lower sash should be furnished with a deep bottom 
 rail, and on the sill should be fixed a deep board instead of the usual shallow 
 bead. The lower sash can by this means be opened, and a current of air with 
 anuj)ward tendency admitted between the upper and lower sash, without any 
 direct draught at the sill level. The part above the transome should be hinged 
 at the bottom, and made to fall inwards to an angle of about G0°, and the 
 sides protected with glazed cheeks to prevent down draught. 
 
 The amount of window area should bear some definite proportion to the 
 cubic space of the ward. It is not very easy to give any definite rule for 
 this proportion, which will be applicable to all wards alike, but in practice 
 it will be found that a foot of window surface to from sixty to eighty feet 
 of cubic space is a useful proportion to work upon. Dr. Thorne Tliorne con- 
 siders that in a well-constructed and efficiently warmed building the amount 
 of vraidow surface should not vary much beyond these limits, and that a 
 proportion of one square foot to seventy cubic feet is, as a rule, the most advan- 
 tageous. The failure to maintain sufficient warmth, and at the same time 
 to properly ventilate the wards of the Children's Hospital at Pendlebury, is 
 attributed by Dr. Thorne Thorne to the excessive proportion of window 
 surface to cubic space, which at that hospital amounts to one foot of window 
 surface to thirty-five feet of cubic space. 
 
 In exposed situations it is desirable to provide additional protection 
 against loss of heat by radiation by glazing the windows with two sheets of 
 glass, with an interspace of about three-quarters of an inch between the 
 two. 
 
 The most suitable material for the surface of the walls of a ward would 
 be one which should present an absolutely impervious washable surface 
 without joints, and not liable to crack. Supposing it were possible to cover 
 the walls entnely with glass without joints, such a surface would be without 
 doubt an absolutely perfect one. Such a thing is, however, impossible. 
 Various modes of approximating to such a result have been suggested ; 
 amongst others, marble, glazed bricks and tiles, and polished Paiian cement. 
 Marble walls, if the slabs could be got in sufficiently large sizes, would be 
 excellent, but can hardly be regarded as practicable because of the excessive 
 cost. Glazed bricks and tiles are the next best substitutes, but in both cases 
 there is the objection of the numerous joints and the impossibility of getting 
 a perfectly even face. Polished Parian cement was at one time thought to be 
 a perfectly impervious surface, but experience has shown that it is scarcely, 
 if at all, superior to ordinary plaster, while much more costly. Until some 
 process is discovered by which a plastered surface can be rendered impervious 
 
THE DWELLING 731 
 
 and washable, the best way to treat the walls of a ward is to form a dado 
 of cement of a height that can be reached by the hand, and to paint and 
 varnish the surface ; above that to finish with ordinary plaster and distemper. 
 The varnished surface can be washed in the ordinary course of ward clean- 
 ing, and the distemper can and ought to be renewed yearly. 
 
 The construction of a ward floor ought always to be what is known as 
 fireproof; that is, of iron beams or joists embedded in concrete. Upon the 
 surface of the concrete the wooden floor, formed preferably of oak or teak, 
 should be laid solid. Apart from the fire-resisting nature of this construction, 
 in itself an element of importance in a hospital, the advantage is gained of 
 there being no space underneath the wooden floor to harbour accumulationa 
 of decaying organic matter, and each ward is more efi'ectually cut ofi" from 
 the ward above and below. 
 
 An important point to observe in' every part of a ward, as indeed also in 
 other parts of a hospital, is the strict avoidance, as far as possible, of all 
 projections, ledges, or angles in which dust can lodge. Thus all the corners 
 of the panels of doors and the panes of window sashes should be moulded 
 instead of square, and no mouldings or recesses (called by carpenters 
 * quirks ') should be permitted. The vertical and horizontal angles of the 
 walls, ceilings, and floors should likewise be rounded, and the same rigid 
 avoidance of corners should be observed as far as practicable in the furniture. 
 
 Ward Offices. — Certain rooms, which for convenience sake may be 
 grouped together as ward offices, must be placed in immediate contiguity 
 to the ward. These offices all have their part in the economy of the ward 
 administration ; upon their completeness will depend much of the comfort 
 and regularity \n.i\x which the ward is worked. 
 
 The duty room, or ward kitchen, is a room in which the plates, cups, and 
 saucers, &c., used in the wards are kept and washed, and in which a certain 
 amount of invalid cooking is done. If there be no separate nurses' room 
 attached to the ward, the duty room is the place where disinfectants, and 
 sometimes medicines, are kept, but these should always be under lock and 
 key, and in charge of the head nurse or Sister. 
 
 A nurses' room is, by some authorities, considered a necessity ; in most 
 older hospitals there is a bedroom and sitting-room combined attached to 
 each ward for the head nurse, but many eminent authorities consider that 
 while on duty a nurse's place is in the ward, and that when off duty she 
 should be entirely removed from the ward atmosphere. From a health 
 point of view the latter arrangement is undoubtedly correct, and if a nurses' 
 room be provided near the ward, it ought certainly to be a sitting-room only, 
 and not a bedroom. 
 
 These two rooms should of course be at the corridor or entrance end of 
 the ward, and may be provided with windows overlooking the ward, though 
 the practical utility of such appliances is questionable. 
 
 One or two small wards or rooms for one patient should in large hospitals 
 be arranged at the corridor end for cases requiring special treatment, or such 
 as for some reason would be better treated alone than in a large ward. 
 
 In close proximity to the duty room should be a linen cupboard for the 
 store of ward linen, a cupboard for patients' own clothes, and a small larder 
 for milk, bread, &c. All these should be properly ventilated and lighted. 
 There should also be provided a suitable place in which to stand the coal trolley, 
 the food trolley (for bringing meals from the hfc), and a wheeled basket for 
 dirty linen. These seem trivial details, but the importance of thinking of 
 these things beforehand and providing for them is not slight. 
 
 The water-closets for the patients and the sink-room are usually and 
 
732 HYGIENE 
 
 most conveniently placed at the further end of the ward. Li many cases also 
 the bathroom is likeAnse at the same end. It is of importance that the 
 atmospheric connection between the ward and the water-closets should be 
 severed as completely as possible, while at the same time access to these 
 offices must be easy and direct. To effect this it is necessary to interpose 
 between the ward and the closets a lobby having windows on each side for 
 * through ' or ' cross ' ventilation. At each end of the lobby is a door, and 
 by this means the air from the closets cannot easily be blown or drawn into 
 the ward. 
 
 In America it is usual to place the water-closets at the entrance end of 
 the ward and to rely wholly upon mechanical ventilation appliances to prevent 
 a flow of air from the closets to the ward. This plan has the advantage of 
 leaving the other end of the wards free for balconies or sun rooms ; but in this 
 country, where natural ventilation is imiversally used, such an arrangement 
 is impracticable. 
 
 The proportion of water-closets to patients should not be less than one to 
 ten, and in none but very small Wards should there be less than two closets. 
 
 The sink-room should be large enough to hold a good-sized slop-sink with 
 a sink for cleaning vessels, a draining board, shelves and racks for bedpans 
 and other crockery, and brooms. A cupboard having free ventilation to the 
 outer air, and a door as nearly air-tight as possible, should be constructed in 
 this room for keeping vessels in which fteces or urine have to be temporarily 
 preserved. 
 
 The bathroom need not of necessity be separated from the ward by a 
 lobby ; neither is there any special advantage in placing it at the same end 
 as the water-closets. Besides the bath, it should contain lavatory basins in 
 the proportion of about one to every five or six patients. The bath should 
 be so placed that a patient can be easily lifted in and out, and carried to 
 and from the ward in a recumbent position. For these and other reasons 
 the bath should have its foot only to the wall. 
 
 Balconies and Barrack Wards. — The treatment of patients in the open 
 air is much more resorted to on the Continent and in America than in 
 this country. In most German hospitals there are covered balconies in 
 which patients are kept duruig the summer months by night as well as by 
 day. In America the ' sun room ' at the end of the ward is a common 
 feature. The ' baraque,' as it is used in Germany, is an institution 
 practically unknown here. It consists of a wooden-framed hut raised about 
 eighteen inches or two feet, or sometimes more, from the earth or brick 
 piers. The spaces between the upright posts are protected by curtains only, 
 which are drawn at night or by day to keep off the sun or rain. The 
 patients, therefore, are practically in the open air ; such a ' baraque ' exists 
 at the hospital at Basel, and is devoted entirely to children (surgical patients 
 only), who are kept there day and night from May to October. 
 
 Operation Boom. — The operation room will vary in size according to 
 circumstances, from the small room, just large enough to hold the table with 
 the necessary adjuncts, to the theatre of a large clinical hospital, with its 
 tiers of seats for students numbering often some hundreds. In large hospitals 
 there are usually one or two minor operation rooms, in addition to the large 
 theatre. These smaller rooms are specially needed for eye operations, for 
 which a light at a special angle is necessary, and which cannot be performed 
 in a theatre lighted entirely from the top. They are also needed for ovarian 
 cases, when these are treated in a general hospital. 
 
 The operation theatre ought to be separated as completely as possible 
 from the wards and the other parts of the hospital. The absolute isolation 
 
THE DWELLING 733 
 
 of the operation theatre is by some surgeons considered so important that in ' 
 some foreign hospitals — as, for instance, at Chartres and at Friedrichshain, 
 Berhn — it forms an entirely detached building, and patients have to be con- 
 veyed thither in a hand ambulance through the garden. 
 
 This, perhaps, is carrying the principle to an extreme point ; the opera- 
 tion theatre ought, however, to be so placed that atmospheric communication 
 between it and the wards and the domestic offices of the hospital is entirely 
 precluded. 
 
 The same precautions to ensure absolute cleanliness must be taken as in 
 a ward, and everything of an absorbent nature should be as far as possible 
 discarded. At the hospital referred to above (Chartres) the walls, floor, and 
 ceiling are of cement, the window sashes and doors are of iron, the tables 
 and shelves for instruments are of glass on iron supports, and the operation 
 table itself is of zinc and iron. The operation room at the Derbyshire 
 General Infirmary has the walls lined with marble to a height of seven feet, 
 above which they are cement. The floor is of marble mosaic, the door and 
 windows of iron, with the frames flush with the wall, and the tops to the 
 sink and lavatory basins of glass. In fact, so far as the structure and fittings 
 of the room are concerned, everything should minister to the condition of 
 perfect asepticism, so necessary to be obtained. 
 
 Immediately adjoining the operation theatre there should be a surgeons' 
 room, a room for the administration of anaesthetics, and, if possible, a small 
 ward for the reception of a patient whom it is not desirable to move back to 
 the general ward immediately after operation. 
 
 Out-patient Department. — Three things are necessary to the orderly 
 working of a large out-patient department : (1) a spacious and well-ventilated 
 waiting-hall, where patients can be grouped and classified according to their 
 cases ; (2) a sufficient number of consulting rooms readily accessible from 
 the waiting room ; and (3) a dispensary with small waiting-room attached, 
 so placed that patients do not have to re-enter the main waiting hall after 
 they leave the consulting rooms. The whole of the department must also 
 be on one floor only, and entirely detached from the main buildings of 
 the hospital. A reference to the plan of the out-patients' department of the 
 Great Northern Central Hospital (fig. 134) will make these points clear. 
 The entrances are separate for each sex, and the two small waiting-rooms 
 are arranged just within each entrance for new patients to wait their turn for 
 registration. Old patients pass straight into the large waiting-hall, where 
 they are sorted out into groups according to their cases. 
 
 The consulting-rooms are four in number, and to each is attached a 
 smaller room for examining patients. There is also a dark room for ophthal- 
 moscopic work. After a patient has been seen by a medical ofiicer he passes 
 into the corridor at the back, and thence into the waiting-room beyond, where 
 he waits his turn in a queue for getting to the dispensary window. This 
 may be taken as a fair example of an out-patients' department in a mode- 
 rate-sized hospital with no medical school attached. In the large clinical 
 hospitals the consulting-rooms would have to be greatly enlarged in order 
 to afford space for the students. In smaller hospitals a less number of con- 
 sulting-rooms would suffice. 
 
 Mortuary. — It is of even greater importance that the mortuary should be 
 a detached building than the out-patients' department, but it does happen 
 that in very crowded situations it is impossible to afford room for a detached 
 building at a sufficient distance from the ward windows ; in such a case the 
 mortuary ought certainly to be relegated to the top of the building, and 
 communication should be made by an outside staircase and lift. The 
 
734 
 
 HYGIENE 
 
 mortuary should include, besides the room where several bodies may be kept 
 at one time, a small chamber where one body at a time can be viewed by 
 friends, and which may take the form of a mortuary chapel. 
 
 KEITH. D.YOVNG^ 
 HENRY HfJLC ) 
 
 /JRCHJTECTS. 
 
 MEN 
 
 
 l^FEET. 
 
 Fig. ia4. 
 
 Attached to the general dead-house, but having no communication with 
 the smaller room, should be the jpost-mortem room, and in the smaller class 
 of hospitals with no medical schools there should also be a room for the 
 pathologist and a small museum. 
 
 The post-mortem room must be top hghted, and should have a floor of 
 some impervious material, made to fall to a channel under the table. The 
 walls should be lined with glazed bricks or tiles, the table should be of marble 
 
THE DWELLING 
 
 735 
 
 on an iron frame, and the shelves should be of the same material. A large 
 and deep sink must be provided, and the waste-pipe therefrom must be treated 
 in the same way as a soil-pipe. An efficient trap should be fixed immediately 
 under the sink, and the pipe taken out through the wall into a vertical pipe, 
 which must be carried up to its full diameter as a ventilator. 
 
 Examples of Hospital Planning 
 
 I. Large General Hospital luith Medical School, University Hospital, 
 Halle, Germany. — This large and important hospital was commenced in the 
 year 1876 and completed in 1884. It consists of sixteen separate build- 
 ings, thirteen of which form the hospital proper, the other three being 
 devoted to teaching purposes. The general disposition of the buildings is 
 shown on the block plan (fig. 135). 
 
 The central block, a, with its four wings, is the surgical house. The central 
 "building is two storeys in height, with a basement, and the out-patients' 
 
 HfJLLE UNIVERSITY HOSPITAL 
 
 MaGDEBUftGER STRaSSE. 
 
 Pig. 135. 
 
 department, operation room, and rooms for the director and the resident 
 medical staff. On the upper floor are also some small wards for two, three, 
 and four patients each. The wings are one storey only in height, and contain 
 each a ward for twenty-four beds, with duty room, nurses' room, lavatory, 
 bathroom, and water-closets. These wings are raised about eight feet above 
 the ground, and the part under the wards is entirely open. At the ends, 
 under the duty room and the other ward offices, the basement is utilised for 
 storage purposes. The floor space per bed is 142 feet, and the cubic space 
 2,210 feet. The beds are arranged in pairs opposite each pier, and a space 
 of about ten feet, with a window, intervenes between the end bed on each 
 side and the end wall of the ward. The floor is finished with terrazzo, a 
 mixture of small pieces of marble and cement ground to a smooth surface and 
 polished. The water-closets are, as is usual in Germany, connected with 
 the ward by an ante-room or passage, and no attempt is made to separate 
 them from the ward air by means of cross-ventilated lobbies. The walls are 
 formed of timber framing, filled in with brickwork and covered inside with 
 boarding. On the south side of each ward is a broad verandah, with steps 
 leading down into the garden. 
 
 These wards, in common with all the rest of the buildings, are warmed 
 
736 IIYGIEXE 
 
 by steam, the pipes for eonveyin.q; 'uhicli are carried round the walls behind 
 the beds. Ventilation is provided for in summer by open windows and a 
 ventilating lantern on the apex of the roof, and in winter by an underground 
 flue connected with the furnace shaft of the boiler-house for carrying oft" the 
 vitiated air, and by openings in the outer walls of the ward for admitting 
 fresh air below the steam coils and pipes. 
 
 The two buildings B and c are respectively the kitchen block and the 
 engine-house. The kitchen block is four storeys in height, and contains, 
 besides the kitchen with its scullery, larders, and other appurtenances, the 
 laundry and bedrooms and day rooms for servants and officers. 
 
 The engine' house contains, besides the boilers and machinery, a disinfec- 
 tion house fitted with a steam-disinfection apparatus. 
 
 Block D contains the gynecological department, and has accommodation 
 for eighty patients in wards varying in size from one to six beds each. Here 
 are also rooms for students and medical stafl:", operation room, lecture room, 
 and apartments for the midwife. 
 
 Block E is the director's house. 
 
 Block F, with the detached blocks G G, comprises the medical department. 
 The central block with its two wings is two storeys in height, besides a half- 
 sunk basement. The basement floor of the central block is devoted to rooms 
 for porters and other men servants. In the basement of the wings are four 
 wards for syphilitic patients, two in each wing ; and in each wing a room 
 for lunatic patients, with a padded room attached. 
 
 The ground floor of the central block contains the out-patients' depart- 
 ment, with rooms for laryngoscopy, electrical apparatus, and for examination 
 of patients, a large lecture hall, and rooms for the director and assistants. 
 The upper floor contains some small wards for children, quarters for resident 
 stafl', registrar's rooms, and library. 
 
 In each wing there is on the ground floor a ward for twelve beds, a smaller 
 ward for three beds, and two private wards for paying patients (one bed each). 
 This arrangement is repeated on the first floor. 
 
 The detached blocks G G are very similar in arrangement to but smaller 
 than the surgical pavilions. The wards are for sixteen beds only, and there is 
 in addition in each pavilion a separation ward for one bed. These pavilions 
 are raised above the ground about 3 feet ; the flooring of the wards is of 
 deal, and the walls are of brick plastered inside. The floor space is 135 feet, 
 and the cubic space 2,033 feet per bed. 
 
 Blocks H I are two-storey buildings, described as ' extension ' pavilions. 
 They contain on each floor a ward for twelve beds, a small ward for two beds, 
 and the usual offices. These pavilions are intended for medical and surgical 
 cases respectively. 
 
 Block L is a one-storey pavilion divided centrally by the entrance, duty 
 room and nurses' rooms, and contains two wards for twelve beds each, one 
 for male, the other for female cases, and is used for isolation purposes. At 
 each end is a separation ward for one bed. The floor space per bed is 128 
 feet and cubic space 1,925 feet. 
 
 K is the chapel. 
 
 M is a two-storey building \\dth basement, devoted to patients suffering 
 from diseases of the eye and ear. The basement is occupied by rooms for 
 the porters &c. and storerooms. The entrance is in the centre on the north 
 side ; the wing to the right of the entrance contains the eye wards, that to 
 the left the ear w^ards. In the central part are rooms for the director and 
 assistants, operation theatre and lecture hall, and nurses' rooms. The wards 
 are arranged for six beds each. 
 
THE DWELLING 
 
 T61 
 
 N is the pathological institute, o the physiological institute, and p the 
 anatomical institute ; b is the icehouse, and q a building in which the sewage 
 of the whole hospital is disinfected before passing into the town sewers. 
 
 The buildings occupy a site of some eight acres in extent. 
 
 /JHTWERP CIVIL HOSPITfIL . 
 
 NEV^ STREET. 
 
 RUE DES IMfjeES. 
 
 BILMB.YER ^V/7/V fllEL 
 
 ARCHITECTS. 
 
 'HftLFPLfIN OF 
 VENTJLfJTlNS SHAFTS. 
 
 plan of a waed pavilion, 
 Fig. 136. 
 
 Civil Hospital, Ankoerp. — This hospital (fig. 136) is the largest and most 
 complete example of the circular ward system yet erected, and it is also 
 specially interesting in having been the first instance in which the ckcular 
 form was adopted. 
 
 The site upon which the hospital stands is nearly ten acres in extent, and 
 is bounded on all four sides by public streets. The large area of the site 
 enabled the buildings to be disposed in such a fashion that the space between 
 the various blocks is extremely ample. The large block (a) at the entrance 
 in the Eue des Images contains the director's and almoner's residence, porter's 
 
 VOL. I. 3 B 
 
738 HYGIENE 
 
 lodge, and rooms for medical students, servants, &c. The corridors for com- 
 munication with the ward pavilions lead oil from each side of the central 
 block of the front building. Proceeding along the western corridor, the small 
 building marked B contains the operation room, with its two adjoining 
 rooms for the surgeons and surgical appliances and two wards for one bed 
 each. The corresponding building to this, c, on the east side, contains the 
 mortuary and 2^ost-inortcm room, with workshops below. Separated from this 
 by a small enclosed yard is a coachhouse, stable, and coachman's dwelling. 
 
 The blocks marked d are the ward pavilions, and are all arranged on the 
 same plan. ■ Each pavilion is two storeys in height, and has cellars under 
 the whole. The corridor is one storey only between the pavilions, with a 
 basement which serves as a subway for communication between the wards 
 and the laundry, and also for access to the ventilating shafts under the 
 wards. On the ground floor, on the side of the corridor further from the 
 ward, is the main staircase, a secondary staircase leading to the roof, a lift 
 for patients, a separation ward, and a room in which are shoots for refuse 
 and for dirty Unen, and a recess in which the pipes for water, gas, &c., are 
 arranged ; on the other side of the corridor are two separation wards for one 
 bed each. From the building which contains all the above accommodation 
 a covered-in bridge leads to the main ward. This bridge, hke those that 
 connect the ward with the water-closets, is only about half the height of the 
 ward itself. By this means the movement of air around the ward is much 
 freer than it would be if the bridges of communication were carried up the 
 whole height of each storey. The wards are Gl ft. 6 in. in diameter, and 
 about 17 ft. in height. They each contain twenty beds, at which number 
 the floor space per bed is 148*5 ft. and the cubic space 2524"5 ft. The 
 actual number of beds, however, in each of these wards is twenty-four, 
 which reduces the floor area to 123"7 ft. and the cubic space to 2103-7 ft. In 
 the centre of each ward is an octagonal space partitioned off with a glass 
 screen some 8 ft. high, and used as a Sister's room. The intention of this room 
 appears to be that the Sister should use it as a sitting-room when on duty, and 
 that the various apphances and di'ugs used in the wards should be kept there. 
 The exact centre of the ward is occupied by the exhaust shaft for foul air, 
 while at each of the right angles of the nurses' room is a shaft for the supply 
 of warm air. The floors of the wards are laid with oak boards, wax polished, 
 and the walls are plastered with a composition of gypsum and Hme. The 
 warming is effected by means of hot air, which is forced into the wards by 
 a fan in the engine-house passing in its way over coils of steam pipes, and 
 can be discharged either at the floor or the ceiling level as desired. The 
 central shaft, already referred to, is provided with steam coils at its base, in 
 order to warm the air and, by its expansion, produce an up current. The 
 separation wards are also warmed and ventilated on the same system. 
 
 The small projecting block to each pavihon contains a tisanerie or 
 tea kitchen, bathroom, lavatory, two water-closets, and two sinks. 
 
 Block E is the chapel, which is connected by an open passage with the 
 main corridor of communication ; the flat roof over this passage affords 
 means of communication between the upper floor of the wards and the 
 gallery of the chapel. Block f contains the kitchen offices and the dis- 
 pensary and drug store ; also dining rooms for male and female con- 
 valescents, attendants, and servants. Block g is the house for the Sisters of 
 Mercy, with the linen store and lint store. Block h at the further end is 
 the bathhouse. Here, as is common in large Continental hospitals, are, 
 besides ordinary baths for both sexes, a Turkish bath, shower bath, two 
 vapour baths, and two sulphur baths. The detached block, J, at the extreme 
 
THE DWELLING 
 
 739 
 
 north of the site, is the laundry, and washhouse, used also for the washing 
 of all the other hospitals in charge of the communal authorities of Antwerp. 
 A ' Barrack ' or Hut Hospital. The Mtmicipal Hospital at Moabit, 
 Berlin. — This hospital (fig. 137) was erected in 1872 by the city authorities 
 of Berlin for the purposes of an epidemic, but it has since been utilised for 
 the reception of patients suffering from all kinds of diseases, including such 
 infectious fevers as typhus and small-pox. The site is a long narrow parallelo- 
 gram of about nineteen acres in extent, and having its longer axis north and 
 south. At the south end are situated the administration buildings : A, porter's 
 lodge ; B, offices and residence for staff ; o, kitchen ; d, engine and boiler 
 house ; b, disinfection house ; f, laundry ; g, g g, stables and stores ; h, fire 
 brigade depot ; i, ice-house ; j, isolation wards. 
 
 J=>Lffrf OF a WARD BLOCK. 
 
 UNEN. 
 
 LRVflTf C. 
 
 ( 
 
 nnnnnnnnnnnnnn-' 
 
 \ 
 
 ' DUTY 
 
 UULIuuUUUUULIUulJ-, 
 
 J°A7. 
 
 CITY BRRRRCK LflZ/JRETH 
 MO ABIT BERLIN. 
 
 ■^> 
 
 IttaURERnEISTER STRHUSS i 
 
 iiniiiiiiiii/ 
 
 
 Fig. 137. 
 
 The ward pavihons, twenty-four in number, are ranged round both sides 
 of the site. Each paviHon is entirely isolated from the others, and the space 
 of about 56 ft. intervenes between. The pavihons are all of one storey, are 
 constructed of timber framing filled in with stone, and lined on the inside 
 with painted boards. The floors are composed of a species of concrete 
 (beton), finished with a smooth surface of cement. The roof projects about 
 6 ft. on each side, and is formed of a double layer of planks grooved together, 
 painted on the inner side, and on the upper surface covered with asphalte. 
 At the entrance of each pavihon is a nurses' room, duty room, room for the 
 temporary storage of dirty linen, and a bathroom and a water-closet ; the 
 two latter are entered directly from the ward, and in the water-closet are two 
 apparatus. Each ward contains twenty-eight beds, with a floor space of about 
 69 ft. per bed and a cubic space of 864 ft. At the apex of the roof is a long 
 
 3b 2 
 
740 
 
 HYGIENE 
 
 BLOCK PLm. 
 
 ' P? ° 'P ^° ^° ^ ?° ^° ?° §" ^, °FEEr 
 
 ventilator, and at the end of each ward are large folding doors, which are 
 constantly open in summer. In the extreme north-west corner of the site 
 are the mortuary (n), waiting hall (o), and shed (p) for burning clothing 
 &c. which has been exposed to infection. 
 
 A Provincial Hospital with no Medical School. — Lincoln County Hospital 
 (fig. 138), designed by Mi-. Alexander Graham, has been selected as a good 
 
 LJtSQQLNiJim COUNTy HOSPITAL. example of a pro- 
 
 i vincial hospital of 
 
 average size. It has 
 accommodation for 
 105 beds. The gene- 
 ral plan is in the form 
 of an H, with pro- 
 jecting buildings on 
 both sides of the cross 
 stroke. The upright 
 strokes are occupied 
 by the wards, which 
 are two storeys in 
 height. The ground 
 floor of that half of 
 the western wing 
 which lies to the 
 south of the cross 
 stroke of the H is 
 devoted to the out- 
 patients' depart- 
 ment, which is thus 
 placed in very inti- 
 mate connection with 
 the wards, the only 
 serious blot on an 
 otherwise excellent 
 plan. The buildings 
 projecting at front 
 and back of the cross 
 stroke contain the ad- 
 ministration offices, 
 the operation room, 
 accident room, and some small wards for eye cases. The large wards are 
 each 88 ft. by 26 ft. 6 in., those on the ground floor being 14 ft. and those 
 on the first floor 16 ft. high. The beds are arranged in pairs between each 
 window. The floor space per bed is 115*2 ft., and the cubic space 1613-7 ft. 
 on the ground floor and 1844-3 ft. on the upper floor. 
 
 Toilet System. Municipal Hospital, St. Denis. — The system of hospital 
 construction of which the new Municipal Hospital at St. Denis is an example 
 is the invention of M. Toilet, an engineer of eminence. 
 
 The special pecuharity of the system is the form -\\ liich M. Toilet adopts 
 as the section of his wards. A transverse section of a ward is in the form 
 of a Gothic pointed arch. The grounds upon which this form is adopted 
 are that it is said to lend itself more readily to efficient ventilation, to 
 prevent stagnation of air, and to present the minimum of surface for absorp- 
 tion. Other characteristics of M. Toilet's plans are the limitation of all 
 ■wards to buildings of one storey only, the complete isolation of the several 
 
 PL/Jfi OF f> W^RD 
 
 lo 5 9 ip 2p 3.0 1*9 ^P 
 U T 1 1 ±^ 1 L 
 
 Fig. 1st*. 
 
 f_L° FEET, 
 
THE DWELLING 
 
 741 
 
 paviKons one from the other, the adoption as far as possible of non-absorbent 
 surfaces, and the avoidance of all angles, the use of fire-resisting materials, 
 the adoption of natural means of ventilation, and the use of balconies and 
 open space beneath the wards. Obviously none of the foregoing are the 
 invention or the speciality of M. Toilet ; but the thoroughness and skill with 
 which he has recognised the advantages of and combined all these features 
 are noteworthy indications of the progress of hospital hygiene in France. 
 
 PLffn OF ONE y^'RRD BLOCK. 
 
 Fig. loO. — Hospital of St. Denis. 
 
 The pointed-arch form adopted by M. Toilet necessitates the provision of 
 a very much larger amount of cubic space per bed than is usual or under 
 ordinary conditions necessary. But as an essential part of the system is that 
 the outlet for foul air is at the apex of the roof, the ordinary rule by which 
 any access of height over 12 feet is disregarded would seem not to be appli- 
 cable in this case. It must, however, render necessary greatly increased 
 warming power. 
 
 Whatever may be the special merits of the pointed arch, of this there can 
 be no doubt, that the general arrangements and the structural details of the 
 hospitals designed on this principle are immensely in advance of anything 
 that had preceded them in France. 
 
742 HYGIENE 
 
 The Municipal Hospital at St. Denis was designed by M. Laynaud^ 
 architect, and, in addition to its being a good example of the Toilet system, is 
 in itself interesting as a type of a modern French provincial hospital. 
 
 The site is of an irregular shape, and situated just outside the old town 
 of St. Denis, close to the glacis of the Fort de I'Est. Its situation ensures 
 that it will never be surrounded by buildings. 
 
 The buildings (see fig. 139) are arranged m detached blocks, there being 
 no covered communication between them, except in the case of two wards for 
 the same class of diseases being coupled. 
 
 The building to the east of the entrance contains the boardroom and' 
 ofiBces, and the kitchen offices, stores, &c. ; that to the west contains the 
 residences for staff and the dispensary. The two buildings to the east and 
 west of the above-mentioned two blocks are for aged women and men 
 respectively. These form the Hospice. 
 
 Of the five blocks forming the central row of buildings, the two at the 
 extreme ends are the medical wards, those to the east being for women, those 
 to the west for men. Each block contains two wards for sixteen beds each 
 and two small wards for two children each. In the centre is a day room,, 
 with duty room, nurses' room, and the usual offices. It is noteworthy that 
 here, as in all hospitals constructed on M. Toilet's system, the water-closets are 
 separated from the wards by cross-ventilated lobbies. The three pavilions 
 in the centre are for surgical cases. Attached to each medical pavilion is a 
 bathhouse, in which are, besides two ordinary baths, the vapour and douche 
 bath usual in Continental hospitals. Beyond the bathhouse on the male 
 side is the laundry. The two small blocks north of the surgical pavilions 
 are for the isolation of infectious diseases ; behmd them is the chapel, and at 
 the apex of the site is the mortuary. 
 
 The large wards each contain sixteen patients. The floor space per bed 
 is about 112 ft. and the cubic space 2,457 ft. The ends of the wards are 
 rounded off at a large radius, and in the centre of the curve at each angle of 
 the ward is a small window. The wards are raised upon piers above an open 
 basement storey which is used as a subway of communication from one ward 
 to the other, and in which the caloriferes for warming the wards are placed. 
 
 A Workhouse Hosiyital. — Perhaps m no department of hospital con- 
 struction has so great an advance been made during the last twenty years 
 as in the infirmaries belonging to large parishes or unions. From being 
 a department of a workhouse, and provided with accommodation often of 
 the most unsuitable nature, the Poor-law infirmary has now come to be 
 recognised as a hospital needing properly arranged buildings and a well- 
 equipped and properly trained staff. The large institutions built by several 
 metropolitan and provincial unions, as, for instance, St. George's Infirmary, 
 Fulham Eoad ; St. Marylebone, Notting Hill ; Manchester Workhouse In- 
 firmary, and Chorlton Union Infirmary, are examples of the improvement 
 that has taken place in recent years. Many of the buildings in question 
 present obvious defects of arrangement, such as a too close proximity of 
 buildings one to another and the piling one over another of many storeys 
 of wards. These, however, in \-iew of the very great improvement in general 
 arrangements, are defects of minor importance. 
 
 In the building illustrated (fig. 140) these defects appear to a less degree 
 than in many others. The site is a fairly ample one, and the buildings are well 
 separated. The plan is a very simple one, and consists of four ward pavilions, 
 each three storeys high, a central administrative block, a detached wash- 
 house, and a mortuary. The ward pavilions are connected with each other 
 and with the administrative block by a corridor which is enclosed at the 
 
THE DWELLING 
 
 743 
 
 sides on the ground floor, but is an open arcade on the first floor. At the 
 entrance is a porter's lodge and a small block of receiving wards. 
 
 Cottage Hosiyltals. — Since the establishment of the first cottage hospital 
 at Cranleigh by Mr. Napper, in 1859, the value of these institutions has 
 been increasingly recognised, and numberless hospitals of varying sizes 
 and of different degrees of good and bad arrangement have been established 
 throughout the country. The Cranleigh Hospital is a very old cottage, and 
 
 HEMiY.MRVIS&SOII. 
 
 EflST DULWICH GROl/E. 
 
 PLfJN OF fl WffRO BLOCK. 
 
 Bf)ixor\ 
 
 10 5 <? _ .W 'Sa 30 ^ So 60 70 80 9 io opppy 
 
 FiG. 140. — St. Saviour's Union Infirmary, Champion Hill. 
 
 the cost of its adaptation to its present purposes was only about 501. Many 
 hospitals of recent years have been built as cottage hospitals, which can in 
 no sense of the term be called cottages. They are, in fact, small pavilion 
 hospitals, and are planned on the lines of the larger general hospitals. A 
 cottage hospital, then, should be, as its name implies, a building of the 
 cottage type, with its special needs as a hospital carefully kept in view. 
 Economy of working is an important point to be observed, as it is often 
 difficult to obtain the funds necessary for maintaining a village hospital. 
 The accommodation for patients in a true ' cottage ' hospital will vary from 
 four to ten or twelve, and the staff will comprise a nurse and one or two 
 
744 HYGIENE 
 
 servants. There should be a room where operations can be performed, which 
 can also be used when required for committee meetings. The other rooms 
 required are a sitting-room and a bedroom for the nurse, a bedroom for 
 servants, and the usual domestic offices for a small household. 
 
 It is scarcely necessary to say that the same scrupulous attention to good 
 sanitary arrangements are as essential in a village hospital for four beds as in 
 a town hospital for 400, and the mistake so often made of neglecting to 
 properly isolate the water-closets and sinks from the wards is as inexcusable 
 in a cottage hospital as it would be in one of the largest type. 
 
 II. Special Hospitals 
 
 Not for Infcctmcs Diseases. — In this class of hospitals are included a great 
 number of institutions which possess no special features of interest apart 
 from the conditions which pertain to general hospitals. Such hospitals as 
 those for diseases of the ear and throat, cancer, and incurables require 
 practically the same arrangements as to details and hygiene as hava been 
 described under the head of General Hospitals. 
 
 Ophthalmic hospitals require to be constructed with special reference to 
 the condition of blindness or semi-blindness of the patients. The careful 
 avoidance of salient angles in positions where a patient would be liable to 
 run against them and possibly injure an eye beyond repair, and the provision 
 of handrails on both sides of all staircases, are points that require careful 
 attention. It is also most desirable to abolish open fireplaces in all wards 
 and rooms used by patients, and to warm by means of hot-water pipes, with 
 a due provision for the supply of fresh air, the flickering light of an open 
 fire being very trying and sometimes injurious to diseased eyes. The lighting 
 of the consulting rooms and the ventilation of the ophthalmoscope rooms are 
 points that require careful attention. The hghting also of the operation room 
 is important ; the top light required in an operation room for a general 
 hospital is for eye operations wholly useless. The window should be entirely 
 vertical, and its aspect should by preference be towards the north. 
 
 Hospitals for children are practically general hospitals with a limitation 
 to the age of the patients. Special attention must be paid to the means for 
 isolating infectious cases, as such diseases as measles, whooping cough, and 
 scarlatina are much more likely to arise in a children's hospital than in one 
 for adults. The ' visiting day ' is undoubtedly the chief, if not the only, cause 
 of the evil ; but inasmuch as it would be a practical impossibility to abolish 
 ' visiting,' the only thing that can be done to minimise the evil is to provide 
 efficient means of isolation. An isolation room must also be provided in the 
 out-patients' department for promptly separating any child discovered to be 
 suffering from an infectious disease. 
 
 For consumption hospitals special arrangements are necessary for the 
 warming and ventilation, in order that, while a copious supply of fresh air is 
 maintained, the temperature of the incoming air may be uniformly kept at 
 such a point as will not be injurious to the lungs of the patients. Large 
 wards are inadvisable in a hospital for chest diseases, and more day room 
 space is also required than in a general hospital, as so large a proportion of 
 the patients are able to leave their beds in the daytime. 
 
 Convalescent hospitals, being intended for patients who, while they have 
 recovered from some acute illness, yet need pure air and rest to enable them 
 to recover their strength, are more properly homes than hospitals. While 
 they require that every detail of sanitation should be as carefully looked after 
 as in any other hospital, there are no special features that need be further 
 referred to here. 
 
THE DWELLING 745 
 
 Lying-in hospitals, though not relatively a very numerous class, have 
 yet suffered a notoriety beyond all others for persistent and excessive 
 mortality. Formerly it was the custom to set apart certain wards in all 
 general hospitals for lying-in cases, and in France this custom still exists in 
 most of the large general hospitals. The evils which this system produced 
 were first specially noticed in regard to the Hotel Dieu at Paris towards the 
 end of the last century. Later on the excessive mortality incident on 
 parturient women at the great Maternity Hospital of Paris attracted the 
 attention of the medical world, and in 1873-75 an enquiry conducted by 
 M. Lefort resulted in the following facts : — 
 
 Deaths 
 
 (1) Deliveries in general hospitals . . . . . . 1 in 24 
 
 (2) „ special „ 1 „ 32 
 
 (3) „ at home 1 „ 528 
 
 (4) „ in houses of ' sages-femmes ' 1 „ 200 ' 
 
 In London, though the lying-in hospitals are comparatively small and 
 few in number, the record of mortahty has been until recently very heavy. 
 The largest and most important lying-in hospital in the United Kingdom 
 is the Eotunda Hospital at Dublin ; but even in this the average death-rate is 
 stated in the report of Dr. Bristowe and Mr. Holmes as between one and two 
 per cent., whilst the death-rate among women confined in their own homes 
 is put by the same authorities at "3 or even '2 per cent. The Eeport of 
 the Committee on Cubic Space in the Metropolitan Workhouses (appointed by 
 the President of the Poor-law Board in 1866) records the remarkable fact 
 that the mortality amongst lying-in women in workhouses was six times less 
 than that in the largest lying-in institution in the metropolis, viz. Queen 
 Charlotte's Hospital. 
 
 The exceptional immunity from disease enjoyed by the patients in the 
 lying-in wards of workhouses was due in the main to the fact that separate 
 labour rooms are commonly provided in those institutions and that each 
 parturient woman was isolated for a time during and after deHvery. And it 
 is equally certain that the excessive mortality so persistently incident on 
 lying-in hospitals both in this country and abroad was due to a great extent 
 to the absence of any means of isolation. 
 
 A lying-in hospital, then, should be arranged with small rooms and not with 
 large wards. Each patient should be kept in a separate room for a certain 
 definite time (usually six days) after confinement, and any case of fever 
 arising in the hospital should be promptly removed to a ward absolutely 
 isolated from the rest of the building. 
 
 Hospitals for Infectious Diseases — In all matters that concern the ques- 
 tion of structural hygiene the class of hospitals now to be discussed are in no 
 degree different from other institutions of the kind. The same scrupulous 
 attention to good ventilation, lighting, and all the various details which con- 
 duce to cleanliness and a healthy condition are equally necessary to all hos- 
 pitals. But in the case of hospitals for infectious diseases there are certain 
 points of arrangement and certain requirements which are special to the 
 class and need to be carefully attended to. 
 
 At the outset it is needful to have a clear understanding of the purpose 
 and objects of a hospital for infectious disease ; and it may be well here to 
 point out that, unlike the great body of general and special hospitals, most 
 hospitals for infectious disease are pubhc buildings provided and supported by 
 the rates, and are in no sense charitable institutions. 
 
 ' These figures are taken from Hospital Construction and Management. Mouat & 
 Snell. 
 
746 
 
 HYGIENE 
 
 The duty of pro\ading hospital accommoclation for infectious fever has 
 been placed by the Legislature on the various urban and rural sanitary 
 authorities, in order that those bodies may be enabled by timely provision of 
 suitable buildings to isolate without delay any case of an infectious fever 
 arising within their jurisdiction. It is this point of isolation which marks 
 the main difference between a hospital for infectious disease and one of the 
 
 CU>se -fyice 6 rg'ySi^i^,_ 
 
 Fig. 141. 
 
 charitable class. In the former the patient is received, not primarily for his 
 own sake, but for the sake of others, in order to prevent him from becoming 
 a source of danger to the community. In the latter the predominant object 
 is the good of the patient himself. 
 
 A hospital for infectious disease, therefore, is essentially a place for isola- 
 tion, a means of defence against the spread of infectious disease, an important 
 weapon with which to ward off epidemics. In order, therefore, to be of any 
 value it is clear that the weapon must be ready to hand at any moment — 
 must be, in fact, prepared and in working order beforehand, and not taken in 
 hand when the disease has already made its appearance. 
 
 ' It cannot be too clearly understood that an isolation hospital, to fulfil 
 its proper purpose of sanitary defence, ought to be in readiness beforehand. 
 During the progress of an epidemic it is of Uttle avail to set about hospital 
 construction. The mischief of allowing infection to spread from first cases 
 will already have been done, and this mischief cannot be repaired. Thus, 
 hospitals provided during an epidemic are mainly of advantage to particular 
 patients ; they have little effect in staying the further spread of infection. 
 Moreover, hospitals provided under such circumstances, to be of any use, 
 must be large and costly, and their construction can seldom be of a kind 
 that is suited in after times for the isolation requirements of their districts.' ^ 
 
 ' Meviorandum on the Prvvision of Isolation Hospital Accommodation by Local 
 Sanitary Authorities, Local Government Board, Medical Department. 
 
THE DWELLING lil 
 
 Hospitals erected under pressure of an epidemic are of necessity hurriedly 
 conceived and too hastily executed ; they frequently are ready for patients 
 only when there are no longer any patients to be received, and, as pointed 
 out in the paragraph quoted above, they commonly prove of little or no service 
 as permanent buildings. 
 
 The extent of hospital accommodation which it is necessary or desirable 
 to provide must depend upon the population and other conditions peculiar to 
 the district it has to serve. Whatever may be the amount of accommodation 
 to be provided, however, the general principles of arrangement will remain 
 the same. 
 
 The simplest type of isolation hospital (fig. 141) must comprise three 
 separate buildings : 1, the administration block ; 2, a block for patients ; and 
 3, the washhouse, mortuary, and disinfection house block. These three 
 buildings may be regarded as the nucleus or irreducible minimum of an 
 isolation hospital. 
 
 The administration block in its simplest form may comprise accommoda- 
 tion for a caretaker, kitchen offices, and two or three rooms for nurses ; or it 
 may be simply a cottage containing a living room and two or three bedrooms 
 for the caretaker with the kitchen offices — such a building as that shown on 
 the plan issued by the Local Government Board, and which accompanies the 
 memorandum on isolation hospital accommodation quoted above. 
 
 The ward block shown on the same plan provides accommodation for 
 two patients of each sex, with two nurses' ante-rooms on the ground floor and 
 their bedrooms above. The third block contains a washhouse, mortuary, and 
 a small disinfectmg chamber. It will be obvious that such a hospital pro- 
 vides the smallest possible amount of accommodation and contemplates the 
 reception of patients suffering from one disease only. 
 
 The next step in advance of this is to enlarge the ward block by the 
 addition of one or more rooms for patients to each section. It then be- 
 comes the typical isolation block in which patients of each sex, and suffering 
 from two distinct diseases, can be treated. This block is the most impor- 
 tant one, and whatever else is omitted this must always be provided. For, 
 take the case of a hospital consisting of a single ward block, containing two 
 large wards with a common entrance, ward, kitchen, &c. A single patient 
 suffering from, say, scarlatina placed in one of these wards renders the ad- 
 mission of patients with any other disease an impossibility. If, on the other 
 hand, the ward block be arranged in two distmct sections as in the model 
 plan (see fig. 142), there is always provision for at least two diseases ; possibly, 
 thanks to the verandah arrangement, for more than two. 
 
 Every hospital, then, must possess, in addition to the administration offices 
 and the washhouse, mortuary, &c., an isolation block ; and this block should 
 always be the first consideration. The immense importance of this isolation 
 block cannot be too strongly urged. Cases have occurred over and over 
 again of a patient supposed to be suffering from an infectious fever being 
 received into a hospital and placed in a ward along with other patients, the 
 nature of whose disease was midoubted, and of the patient in question being 
 found not to be suffering from any infectious disease whatever. This patient 
 has then been, notwithstanding all precautions, removed, and again ad- 
 mitted to the same ward with the particular disease fully developed, and 
 which had been contracted during his short previous stay in the ward. Such 
 a case may at any time occur and will occur unless isolation hospitals are 
 what they profess to be, and are provided with proper isolation wards into 
 which doubtful cases can be admitted. An isolation hospital utterly fails ia 
 its purpose if it becomes the means of propagating disease to healthy persons^ 
 
748 
 
 HYGIENE 
 
 tensive 
 
 suitable 
 
 matron 
 
 In addition to this 
 there should be a ward 
 pavilion, or pavilions, 
 modelled on the plan 
 issued by the Local Go- 
 vernment Board and 
 containing from six to 
 as many as twenty beds. 
 The latter number will 
 only occur in very large 
 hospitals, and large 
 hospitals for infectious 
 diseases are not very 
 desirable. The simplest 
 form of the ward pavi- 
 lion consists of two 
 wards with a nurses' 
 duty room intervening ; 
 also a linen store, small 
 larder, and space for 
 movable bath, and for 
 each ward its water- 
 closet and sink room. 
 Such a pavilion is of 
 course intended for pa- 
 tients of both sexes. 
 In large hospitals the 
 pavilions for each sex 
 may with advantage be 
 separated, and it will 
 be of further advantage 
 to provide one or more 
 separation wards for 
 one bed each in each 
 pavilion. The space for 
 movable bath will de- 
 velop into a bathroom 
 and should be so ar- 
 ranged that a patient 
 on being discharged 
 may step from the bath- 
 room into the open air. 
 A day room for conva- 
 lescent patients is also a 
 very desirable addition 
 where it can be ar- 
 ranged. 
 
 The administration 
 buildings for a large 
 hospital will need to be 
 on a much more ex- 
 scale than the simple caretaker's house, with bedrooms for nurses 
 for a hospital for some twenty or thirty beds. Apartments for the 
 and one or two resident medical officers will have to be provided, 
 
 (0 
 o 
 
 lu 
 ta 
 
 z 
 
 ui 
 
 H 
 
 DC 
 
 2 
 
 z 
 
 0. 
 
THE DWELLING 749 
 
 also rooms for the steward and storerooms of a size proportionate to 
 the extent of the hospital. Day rooms for nurses and servants will also be 
 required, and ample bathing arrangements for all the staff are necessary. 
 
 The mortuary building, instead of being only a single room which has to 
 serve the purpose both of mortuary and post-mortem room, will contain a 
 properly appointed j^ost-mortem room, a mortuary chamber provided with a 
 glass screen to separate the bodies from the friends who come to see them, 
 and a small waiting room. 
 
 The laundry, besides being increased in scale, should in large hospitals be 
 divided into two complete laundries, one being for the patients' clothes, the 
 other for those of the staff. 
 
 The disinfection house does not admit of great variation. In the smallest 
 hospital, as in the largest, an efficient apparatus is a necessity, and the 
 difference in size between the largest and smallest machine is not very great. 
 The building containing the disinfecting apparatus must be so planned that 
 the room in which are the articles to be disinfected is entirely shut off from all 
 communication, except by way of the apparatus itself, with the room into 
 which they are received after undergoing the process. This arrangement 
 involves the necessity of having ,two doors to the machine, and the machine 
 itself must pass through the dividing wall between the two rooms. 
 
 For the smaller class of hospital a single coachhouse to hold the ambu- 
 lance will suffice, and indeed in many hospitals of large size room for two 
 or three ambulances will answer all the requirements. It may, however, be 
 desirable to arrange for a complete service, including stables and rooms for 
 men. Such an ambulance service on a large scale has been organised by the 
 Metropolitan Asylums Board. 
 
 Thus far reference has been made to buildings only, and it will be seen 
 that in every detail the prevailing idea is that of isolation. In the placing of 
 the buildings on the site and in the extent' of the site itself the same idea 
 must be constantly kept in view. It has been laid down by the Medical De- 
 partment of the Local Government Board that no building which is concerned 
 with the infected persons, such as the wards, or with infected things, such as 
 the mortuary, laundry, ambulance house, and disinfection house, should be 
 placed nearer than forty feet to the boundary of the site. The reasons for 
 the adoption of forty feet as the minimum distance have been arrived at by 
 a comparative study of the history of many hospitals with various conditions 
 of buildings and surroundings, and experience has shown that in well-ordered 
 hospitals with ample space about the buildings there is practically no risk of 
 the spread of the infectious fevers, other than small-pox, beyond the walls of 
 the hospital. 
 
 It is, however, not sufficient merely to provide a space of forty feet between 
 the boundary and the infected buildings, but the space in question must be 
 constituded a veritable sanitary zone to which no unauthorised person can 
 have access. An instance of what actually occurred in a fever hospital will 
 perhaps show more clearly than anything else the importance of this pre- 
 caution. A woman whose daughter was a patient in a fever hospital went 
 to inquire after her child, carrying in her arms her baby. On entering the 
 hospital grounds through the gate, an ordinary five-barred one with no lock, 
 she saw her child at the open window of one of the wards. She immediately 
 made straight for the window, kissed the child, and held up the baby to kiss 
 its sister, and she remained at the window talking to her child some twenty 
 minutes before her presence was discovered. In that twenty minutes the 
 baby had contracted scarlatina from its sister, and from that disease so caught, 
 it died. This hospital, therefore, for lack of proper precautions and control, 
 
750 HYGIENE 
 
 became an active agent in the spread of disease, instead of being, as it should 
 be, a safeguard and defence. 
 
 The entire site of an isolation hospital should be surrounded with a wall 
 or fence at least high enough to prevent ingress or egress. Entrance to the 
 hospital grounds should be by gates, which are kept under proper control, 
 and the patients should not be allowed to enter the forty-feet space under any 
 circiunstauces whatever. The importance of this latter regulation may be 
 best illustrated by the fact that infection has actually been conveyed to 
 persons outside a hospital by means of things thrown over the boundary 
 fence by patients. 
 
 As illustrating the practical application of the foregoing principles the 
 plans of two isolation hospitals are given, the first, at Warwick, being 
 an example of the smaller type of hospital ; the second, at Newcastle, being 
 an example of a hospital suitable for a large and populous town. 
 
 The hospital at Leamington (fig. US), erected for the Warwick Joint 
 Hospital Board, consists at present of four detached buildings. The adminis- 
 tration block contains rooms for the matron, nurses, and servants, and the 
 usual kitchen offices. At one corner of the kitchen is a serving window, which 
 opens on to a verandah, whence the meals for the patients would be handed 
 out. The isolation block is planned on the lines of the Local Government 
 model plan, and contains in each half a ward for three beds and two wards 
 for one bed each, a duty room, and a water-closet or slop sink. Each half is 
 provided with a movable bath and the hot-water supply to each is independent. 
 
 The ward block contains two wards for six beds each, with water-closet 
 and sink, a duty room, small larder, linen closet, and a bathroom. The latter 
 has a door leading on to the entrance porch in order that patients on being 
 discharged may leave the bathroom direct into the open air, and so not 
 return into the corridor after putting on their uninfected clothes. 
 
 The fourth block contains the mortuary, disinfection house, ambulance 
 house, and laundry. 
 
 The New City Hospital for Lifectious Diseases at Newcastle-upon-Tyne 
 (Plate Vn.) occupies a site of about eleven acres. The buildings are eleven 
 in number, five of them being devoted to the reception of patients. At the 
 entrance is the porter's lodge, with carriage gates on either side, one entrance 
 leading to the administration building, the other to the various ward blocks. 
 
 The administration block is a large building divided by a corridor into 
 two parts, the front part containing the residence of the staff, while the back 
 wing, which is one storey only, contains the kitchen offices, stores, and 
 officers' laundry. The small block in the centre is an isolation block having 
 accommodation for six patients in four wards and two duty rooms. The 
 building is divided into two halves, whose respective entrances are on opposite 
 sides. The four ward pavilions are each exactly alike and are arranged as 
 follows : — 
 
 At the entrance is a receiving room, which is also used as discharging 
 room, and is provided with means for bathing patients on their arrival and 
 discharge ; next to this is the duty room or ward scullery ; on the oppo- 
 site side of the passage is a covered yard, in which are placed the water- 
 closet for nurses, coal store, and the receptacles for foul linen, dust, &c. 
 Between the block in which the above rooms are placed and the entrance 
 to the ward pavilion proper a cross-ventilated lobby intervenes. To the 
 right and left of the entrance lobby are wards, each containing ten beds ; 
 immediately opposite the entrance is a nurses' room ; while projecting out 
 from the end of each ward are two small wards for one bed each. The 
 nurses' room is provided with no less than four inspection wuidows, one 
 
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 \ /' i 
 
 
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 \J K 
 
City Hospital for jN£tc tio uji^^Disea^e^ Newc ASTLt upon Tyn e , 
 
 er ected on th e Kstale ol" [he Co rpur alioiL at Walk e i- oti Tvii e. 
 
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752 HYCrlEXE 
 
 into each laru^e ward and one into each small ward. At the further end 
 of each ward are two projecting wings, one containing two water-closets 
 and a sink, the other being a bathroom. 
 
 The buildings shown in outline indicate the future extension of the 
 hospital. The laimdry and washhouse, the ambulance house and stable, 
 the disinfection house and the mortuary are all sufficiently indicated on the 
 plan, and present no special features calhng for remark. 
 
 Besides the urban and rural sanitary authorities, to which reference has 
 been made above, there is a third class of authority whose duties are con- 
 cerned mth the isolation of cases of infectious disease — port sanitary 
 authorities. Upon these bodies falls the duty of isolating patients who are 
 found to be suffering from any infectious fever on board vessels within their 
 ports. Vessels arriving in port are inspected by the officers of the authority 
 if either known or suspected of being infected. 
 
 The provision of hospital accommodation made by port sanitary 
 authorities consists in some cases of land hospitals and in some cases of 
 floating hospitals. As an example of the latter kind, which would appear to 
 be the most suitable for the purpose, the following description of the floating 
 hospital of the Tyne Port Sanitary Authority will be interesting : — 
 
 ' It [the hospital] is built on ten cylindrical iron pontoons, with hemi- 
 spherical ends. The buoyancy of each pontoon is 53^ tons, so that the 
 floating power of the hospital is equal to 535 tons. The pontoons are each 
 70 feet long and 6 feet in diameter, and resemble huge boilers. Upon each 
 pontoon there are seven " saddles," which support a strong framework of 
 iron, consisting of longitudinal rolled girders. These girders are braced 
 together by diagonal T-iron, and upon them is carried a deck of creosoted 
 timber which constitutes a platform. Upon this deck or platform the super- 
 structures, or the hospital and its adjuncts, are erected. It is surrounded 
 by a neat handrail, and access from the river is obtained by a gangway in 
 the front centre of the protection rail. The deck is partly occupied by three 
 main buildings, six smaller structures, and a mortuary. The main buildings 
 are each 65 feet long, 23^ feet wide, and about 20 feet high. These are 
 divided into two hospital wards, one of which will contain six and the other 
 four beds. They are spacious, light, and airy apartments, having large 
 windows and special means of ventilation. The interior is lined with 
 polished pitch pine in narrow strips. In each ward there is a central shaft 
 through the roof, fitted with Kite's patent ventilator for carrying off the 
 vitiated air. Near the floors there is a series of ventilators for the admission 
 of fi-'esh air, and under the floor of each apartment an air space of about ten 
 inches, which will secure a constant circulation of fresh air. Beneath the 
 surface of the river and the platform — a space of four feet — ^there will be a 
 perfectly free current of pure air. The rise and fall of the tides and the 
 current produced by the spaces between the pontoons will prevent the 
 possibility of any impurity existing beneath the hospital. Between the two 
 wards of each hospital is an apartment for the nurse. These apartments 
 are fitted with glazed doors on either side, so that the nurse can command a 
 full view of each ward. There are also entrances from the deck to the dif- 
 ferent wards. The main buildings are so arranged that they can be com- 
 pletely isolated, and they are all fitted up alike. The platform is 140 feet 
 long and 80 feet wide, and there is ample space in front of the buildings for 
 the recreation of convalescent patients. The space between the pontoons is 
 14^ feet from centre to centre, and each is detachable, so that any one may 
 be removed at will for cleaning and painting. They can also be revolved in 
 their places without removal. They are reached internally by means of 
 
THE DWELLING ' 753 
 
 manholes, placed to correspond with trap-doors in the main or platform 
 deck.' ' 
 
 The treatment of small-pox in an epidemic form has of late years given 
 rise to much discussion on account of its apparent tendency to spread beyond 
 the walls of the hospital in a fashion entirely different from the behaviour 
 of other infectious fevers under similar conditions. 
 
 This characteristic of small-pox was first particularly observed in 1880, 
 when a special incidence was remarked as occurring in the immediate neigh- 
 bourhood of certain of the hospitals of the Metropolitan Asylums Board in 
 London. An inquiry into the circumstances connected with the outbreak 
 of 1881 with reference to the Fulham Hospital resulted in the following 
 conclusions by Mr. Power, which are characterised by Dr. Buchanan as 
 ' unexpected but most instructive : ' — 
 
 ' There has been in each epidemic period an excessive incidence of small- 
 pox on houses in the neighbourhood of the hospital as compared with more 
 distant houses in Chelsea, Fulham, and Kensington. 
 
 ' The percentage of houses invaded in the neighbourhood of the hospital 
 has increased. This gradation has been very exact and very constant. 
 
 ' Houses upon the chief lines of human intercourse with the hospital have 
 not suffered more than houses lying in other directions from the hospitals. 
 
 ' In point of time, there has been a very marked relation between the 
 varying use of the hospital and the manifestations of excessive small-pox 
 in the neighbourhood. This relation has not shown itself while the use of the 
 hospital has been for convalescents only. 
 
 ' The appearance of excessive small-pox in houses around the hospital has 
 never been delayed until the hospital has become full or nearly full. It has 
 been always most remarkable at the time when admissions to the hospital 
 were beginning to increase rapidly. 
 
 ' On comparison of different epidemics, an almost constant ratio is observed 
 between the amount of the hospital operations and the degree of excess of 
 small-pox in the neighbourhood.' ^ 
 
 After careful and minute inquiry into the whole administration of the 
 hospital during the period concerned, Mr. Power was forced to the conclusion 
 ' that there must have been some condition or conditions operating to pro- 
 duce the observed distribution of small-pox around the hospital that have 
 pertained to the hospital as such, and that have been in excess of the con- 
 ditions for small-pox extension as usually recognised.' ^ Other and inde- 
 pendent observations with regard to the hospitals at Hampstead, Homerton, 
 and Deptford, and to the old Small-pox Hospital at Highgate, produced 
 similar results ; and the whole question was inquired into by a Eoyal 
 Commission. 
 
 The recommendations of the Eoyal Commission with regard to small- 
 pox were that the mild and convalescent cases should be provided for in 
 hospitals out of London, and that the acute cases, too ill to take a long land 
 journey, should be treated in the existing hospitals, but that the number of 
 the latter class to be received into anyone hospital should be limited to thirty 
 or forty cases. 
 
 These recommendations the Metropolitan Asylums Board met by pro- 
 viding at Darenth a large small-pox camp, and in the river at Long Eeach 
 a floating hospital composed of three ships, the ' Castaha,' the 'Atlas,' and 
 
 1 Annual Report of Medical Officer of Health to River Tyne Fort Sanitary for the 
 Year ending December 31, 1886. 
 
 2 On the Use and Influence of Hospitals for Infectious Disease. Supplement to the 
 Tenth Anmial Report of the Local Government Board. 1882. 
 
 VOL. I. 3 c 
 
754 HYGIENE 
 
 the 'Endyniion.' The camp is now replaced by a permanent hospital 
 for 800 patieiits. The ' Castalia ' and ' Atlas ' are appropriated to the 
 treatment of patients, and ali'ord accommodation for 200 and 150 respec- 
 tively, and the ' Endymion ' is used for administration purposes and for 
 housing the staff. The ' Castalia ' is a twin ship built for service between 
 Dover and Calais, for which purpose she proved to be unsuitable, and 
 eventually came into the possession of the Metropolitan Asylums Board. 
 Upon the upper deck are five huts, built obliquely across the long axis of the 
 vessel These huts form the wards of the ' upper hospital,' the ' lower 
 hospital ' being one large ward the whole width of the vessel. At each end 
 are buildings containing the ward ollices, reception rooms, bathrooms, lava- 
 tories, water-closets, and one isolation room on the lower deck and two on the 
 upper deck. The three centre wards on the upper deck are 54 feet long by 
 20 feet wide ; the two end ones are 50 feet long by 38 feet wide. 
 
 A laundry and other administrative buildings have been erected on the 
 shore abreast of the ships. 
 
 To convey patients to and from the ships there is a river ambulance 
 ser%nce, consisting of two vessels of eighty tons each and fitted up with wards 
 for convepng patients in bed, and a smaller launch. In connection with 
 this service there are piers with receiving rooms, waiting rooms, &c., at 
 Blackwall, Eotherhithe, and near Wandsworth Bridge. It seems probable, 
 therefore, that in any future epidemic of small-pox in London all or nearly 
 all the patients will be conveyed down the river to the ships, instead of being 
 treated m the land hospitals. 
 
 In all hospitals for infectious diseases provision must be made to prevent, 
 if possible, the conveyance of infection to the outside world, either by patients 
 on their discharge or by nurses or servants going outside the gates. For 
 patients on their discharge a suite of three rooms communicating with each 
 other should be arranged. The first room should be just sufficiently large for 
 one patient to undress in. In this room the patient leaves his (or her) 
 infected clothing. The second or intermediate room is a bathroom. After 
 bathing, the patient enters the third room, where he finds a complete suit 
 of clean, or preferably new, clothing, which he puts on. Having dressed, he 
 should leave the building by a door leading directly into the open air, and 
 should not again enter any part of the hospital buildings. For the staff 
 ample bathing accommodation should be provided ; in order that, as far as 
 possible, it should be made a rule that no one employed in the hospital wards 
 should leave the grounds without having previously bathed. It is obvious 
 that such a rule as this cannot be rigidly enforced, but, nevertheless, the 
 means of complying with it should be provided, and its observance should be 
 encouraged as far as possible. 
 
 Asylums for the Insane. — Although, as a matter of fact, the great 
 majority of patients in an asylum are persons in bodily health, the general 
 arrangements of the buildings are not unlike those of a hospital, and the 
 general principles of hygiene are, to a large extent, alike in both classes of 
 buildings. 
 
 The planning of an asylum is largely governed by questions of classifica- 
 tion, disciphne, and control. The several classes of patients, usually at least 
 four of each sex, have to be separately accommodated, workshops and 
 laundries have to be provided for those who can work, and all have to be so 
 placed with regard to each other and the administration offices that the 
 labour of supervision is economised as far as is consistent with other neces- 
 sary conditions. 
 
 The old system of planning an asylum was to build what practically 
 
THE DWELLING 755 
 
 became one huge block, with free communication of air from one end to the 
 other. It is now generally conceded that such a plan is hygienically bad, 
 and that the right system is to divide the asylum into separate blocks, either 
 of the pavilion type or some modification of the gallery ward plan, in such a 
 manner that each section forms a separate block in itself, and is atmospheri- 
 cally distinct from any other block. The pavilion system obviously lends 
 itself readily to such conditions, and with each pavilion connected to the 
 next by a covered way, with free cross ventilation, no interchange of air from 
 one pavilion to the other can be possible. The modified gallery ward 
 plan has, however, advantages over the pavilion type in the internal 
 arrangements of day rooms, and provided there is a sufficiency of cross 
 ventilation to the dormitories, it is in some respects preferable to the pavilion 
 ■system. 
 
 Whichever plan is adopted, it is of the greatest importance to arrange the 
 day rooms in such a way that they are exposed to the direct rays of the sun 
 to as great an extent as possible. The choice of a site, therefore, with a good 
 south aspect is an important consideration. The site should not be too ex- 
 posed, but should be protected from the north and east. ' Bleak exposed 
 sites render the buildings much more difficult to warm, and the out-door 
 recreation of the more feeble patients has to be greatly curtailed.' ^ 
 
 The necessity for limiting the height of the buildings to two storeys 
 involves the covering of a large area of ground ; a circumstance that cannot 
 fail to have a favourable influence upon the health of the inmates. 
 
 The separation of the water-closets from the buildings to which they are 
 attached by cross-ventilated lobbies is as necessary in an asylum as it is in a 
 hospital, and the details of all such offices need to be carefully thought out, 
 keeping always in view their liability to injury from the mischievous habits 
 of the patients. 
 
 A liberal provision of baths must be made, and in addition to the ordinary 
 baths it would seem to be desirable or, according to Dr. Greene, ^ necessary 
 to provide Turkish baths also. 
 
 Every asylum must be provided with its hospital for the isolation of cases 
 of infectious disease. The permanent accommodation need not be large, 
 prompt isolation being the object aimed at. Some modification of the 
 isolation block recommended for adoption by the Local Government Board 
 would seem to meet the case admirably, in addition to which a permanent 
 block of kitchen offices and laundry, with rooms for nurses and servants, is 
 necessary. Should an epidemic arise, the permanent accommodation can 
 be very readily supplemented by the erection of wooden huts or tents. 
 
 Infirmaries, Sanatoria, and Isolation Wards for Schools. — In con- 
 sidering the provision needful for the care and treatment of diseases arising 
 in schools, it will be well to divide the subject into two classes : (1) the 
 boarding schools of the higher grade, including all the large public and 
 private schools ; (2) orphanages and kindred institutions of the charitable 
 sort and the schools of the pauper class, supported whoUy or in part by con- 
 tributions from the rates. 
 
 In most schools of the public school type the boarders are distributed 
 about in various masters' houses, though in some cases the whole of them 
 are housed in one building. 
 
 In every large school, whether it consists of boarders only or of both 
 
 ' The Hygiene of Asylums for the Insane. By E. Greene, F.E.C.P.Ed., Medical Super- 
 intendent, County Asylum, Northampton. 
 ^ Op. cit. 
 
 3 c2 
 
756 HYGIENE 
 
 boarders and day scholars (or ' home boarders '), suitable provision must be 
 made : (a) for cases of ordinary slight ailments ; (b) for cases of accident or 
 severe sickness, not being infectious ; and (c) for cases of an infectious 
 nature. 
 
 For the first class, which would include boys sufficiently out of sorts to 
 necessitate their staying away from school, but not in any case seriously ill, 
 a room or two in each master's house, separated from the general dormitories, 
 is all that is required. 
 
 The cases comprised in the two other classes require entirely separate 
 treatment, and for them a separate building or buildings must be provided. 
 The practice of existing schools with regard to the question of the separation 
 of infectious from non-infectious cases is by no means uniform ; but the 
 opinion of the Medical Officers of Schools' Association on the question is very 
 distinct. They lay down the principle that every school ought, if possible, 
 to be provided with two buildings^an infirmary for accidents and non- 
 infectious cases, and a sanatorium for infectious cases. No doubt this view 
 is a sound one, and ought to be adopted wherever possible. On the other 
 hand, the objection on the score of the additional cost of two establishments 
 cannot be altogether disregarded, especially in the case of schools of moderate 
 size, and the actual experience of existing schools must be allowed its due 
 weight. 
 
 The Eugby School Sanatorium (fig. 145) is used for all kinds of ill- 
 nesses, whether infectious or not, with the single exception of scarlatina, for 
 which a separate cottage is provided in the grounds attached to the sana- 
 torium. Here is an instance of one building serving for all purposes (with 
 the limitation noted), and of which the medical officer says that he has 
 never known a single instance of any disease spreading from one boy to 
 another.' 
 
 The question is one of planning and of administration — planning in the 
 sense of careful structural arrangement for absolute isolation of the various 
 parts of the building, and administration in the sense of equally careful 
 precautions to prevent the structural isolation being rendered useless by 
 personal carelessness. 
 
 The proportion between the number of boarders in the school, and the 
 accommodation to be provided for cases of sickness, will vary slightly accord- 
 ing to the average age of the pupils. The Council of the Medical Officers of 
 Schools' Association consider that when the average age of pupils does not 
 exceed twelve years accommodation for 5 per cent, of the boarders is a sufficient 
 provision of beds for non-infectious cases ; but that when the average age is 
 fifteen years the proportion of beds should be raised to 6 or 7 per cent. For 
 cases of infectious disease the pro%dsion is fixed by the same authority at 20 
 per cent, if measles is to be included, and 10 per cent, excluding that disease. 
 The total provision, therefore, may be taken at from 25 to 27 per cent., or 
 from 15 to 17 per cent, excluding measles. These figures may be somewhat 
 modified by the following circumstances : — 
 
 (a) If the school is arranged on the ' house system ' and the several 
 masters' houses are distinct and isolated, the accommodation for infectious 
 diseases may be reduced from 20 to 16 per cent. 
 
 {b) If the school mcludes a large proportion of day scholars a further 
 reduction of 2 per cent, may be made. 
 
 So that for infectious diseases in a school fulfilling the last-named con- 
 ditions a total provision of 14 per cent, of the total number of boarders would 
 be regarded as sufficient. 
 
 ' Duke's Health at School. 
 
THE DWELLING 757 
 
 Taking- first the infectious class of diseases, the most important point to 
 hear in mind is that a sanatorium (nsinj? the word as applying to the huilding 
 for infectious diseases, and as distinct from the infirmary or huilding for 
 non-infectious cases), is primarily a building for isolation purposes ; a means, 
 that is, of promptly separating initial cases of an infectious nature if possible 
 before the disease has had time to communicate itself to others. 
 
 Inasmuch, however, as it is not always possible to detect and to isolate 
 initial cases before the disease has had time to spread, provision must be 
 made for the possible contingency of an epidemic ; equally obviously a disease 
 may be contracted by several boys at the same time and from the same cause, 
 and thus it may happen that several cases of one disease may arise simulta- 
 neously, which yet by prompt isolation may be prevented from becoming 
 epidemic. 
 
 Provision must also be made for the treatment of at least two infectious 
 diseases at the same time. For, although it rarely happens that two infectious 
 diseases are epidemic in a school at one time, yet such an occasion might 
 arise, and it is necessary to provide against it. 
 
 The accommodation necessary to be provided in a sanatorium (assuming 
 it to be a detached building) will comprise the following : — 
 
 1. Administration, including the matron's rooms, kitchen offices, linen 
 and other stores, servants' rooms, and one or two spare rooms for extra 
 nurses when required. 
 
 2. At least two general wards for from four to eight beds, eight being 
 the maximum. 
 
 3. Two or more isolation rooms for one bed each. 
 
 4. A convalescent room. 
 
 5. Nurses' rooms, bathrooms, and small pantries adjoining the wards. 
 
 6. Water-closets for patients, for nurses, and for servants. 
 
 7. Disinfecting apparatus. 
 
 8. Ambulance house. 
 
 9. Mortuary. 
 
 The administration should be a separate block placed centrally and com- 
 municating with the ward blocks by means of corridors, either entirely open 
 at the sides, or provided with ' through ' ventilation. The matron, who should 
 usually be a permanent officer, should have a waiting room and bedroom ; 
 and her bedroom should be placed conveniently near to either one or both 
 the isolation rooms. As the matron will also have to act as housekeeper, the 
 stores both of linen, crockery, and of food will have to be placed under her 
 immediate control. A small cabinet for keeping drugs &c. under lock and 
 key may conveniently be placed in her sitting room. 
 
 It is very desirable there should be a convalescent room, especially for 
 scarlatina cases, with their long and tedious period of convalescence. It is 
 not, however, an absolute necessity. 
 
 Attached to each ward must be a nurses' room, large enough to be used 
 us a sitting room by day and bedroom by night. It should be entered from the 
 corridor and may, if desired, have a small window overlooking the ward, 
 though there is little practical utility in the latter arrangement. For each 
 ward must also be provided a small pantry or duty room, sufficiently large to 
 contain a sink, china cupboard, and a small gas stove for warming beef-tea 
 and preparing special invalid food, drinks, &c. Adjoining the last should 
 be the bathroom, so arranged that a patient can on his discharge leave the 
 sanatorium by the casement window instead of going back into the corridor. 
 The water-closets for the patients should of course be placed in projecting 
 ■wings, with a cross-ventilated lobby interposed between them and the w^ards. 
 
758 
 
 HYGIENE 
 
 One water-closet must be provided for "the nursing staff and one for the 
 servants, and these also should be cut otf by cross-ventilated lobbies, though 
 the latter might be out of doors in a small yard. Where possible a bathroom 
 should be provided for the nurses in order that they may have a bath and a 
 complete change of clothes before going outside the sanatorium. 
 
 A properly arranged disinfection apparatus is a necessity of the highest 
 importance. The building in which it is placed should be divided into two 
 rooms by a brick wall, and the apparatus provided with two doors fitted so 
 
 A7/VC EDW/JRD V/s SCHOOL 
 
 SHERBORNE . 
 
 /VEW SffNflTORIUM 
 FIRST FLOOR PLflN. 
 
 ^ . I if. I M? -^P ^° ^■° '^' 
 
 Fig. 144. 
 
 that one door of it opens into one room and the other door into the other 
 room. Clothing to be disinfected will be taken into one room, which will be 
 devoted solely to the reception of infected things, placed in the apparatus, 
 and when disinfected taken out at the door in the other room, into which 
 latter, therefore, only disinfected clothes will come. The apparatus should be 
 supplied -odth suitable means of drying the clothes if these are exposed to 
 the application of steam. 
 
 An ambulance house will be required where patients have to be brought 
 from or sent away to any great distance. 
 
THE DWELLING 
 
 759- 
 
 GROUND FLOOR PLAN. 
 
 'f n i ? ? !£_ 
 
 ^ ffpEET. 
 
 A small detached chamber suitably constructed must be set apart for the 
 temporary reception of the body of any patient dying in the sanatorium. 
 
 The sanatorium erected in 1887 for King Edward VI.'s School at Sher- 
 borne is an example of a building intended for the treatment of infectious 
 diseases only. It consists, as will be seen from the plan (fig. 144), of two dis- 
 tinct blocks connected to each other by covered ways entirely open at the 
 sides. 
 
 The centre block contains on the ground floor the matron's sitting room 
 and bedroom, servants' bedroom, and kitchen offices. Advantage is taken 
 of the fall of the ground eastwards to get an additional floor under the 
 kitchen, in which are 
 placed the larder, 
 coal store, boiler 
 room, and servants' 
 water-closet. 
 
 On the upper floor 
 of this block are two 
 isolation wards for 
 one bed each, having 
 a floor area of 117 
 feet and cubic space 
 of 1,525 feet ; and a 
 ward for four beds, 
 with a floor area of 
 118 feet and cubic 
 space of 1,522 feet 
 per bed. 
 
 The south-east 
 block contains on 
 each floor a small 
 pantry, with space 
 outside for a portable 
 bath, a nurses' room, 
 and a general ward 
 for eight beds, with 
 water-closet and sink 
 room attached. Each 
 ward has a floor area 
 of 90 feet and cubic 
 space of 1,080 feet 
 per bed ; in addition 
 to which is a bay win- 
 dow of sufficient size 
 
 to hold a table at which convalescent boys can have their meals. Each 
 ward is warmed by two hot-water coils in addition to a large open fireplace. 
 
 The central block and the south-east wing only have at present been 
 erected, the remaining wing being left for future erection. 
 
 As an example of an infirmary for both infectious and non-infectious 
 eases, we are enabled, through the courtesy of the head master (Dr. Percival) 
 and the architect (Mr. F. C. Penrose), to reproduce the plan of the Eugby 
 School Infirmary, built in the year 1859.^ (Fig- 145.) 
 
 This building consists of three wings, radiating from a central circular 
 
 ' The plan here given is reproduced, with the autlior's permission, from Dr. Duke's 
 Health at School. 
 
 FIRST FLOOR PLAN. 
 
 so So 
 
 o 5 io 
 
 4? 
 
 FEET. 
 
 Fig. 145.— Eugby School Infirmary- 
 
7G0 HYGIENE 
 
 staircase. On the ground floor two of the wings arc devoted to sick-rooms, 
 and the third to the administration, matron's quarters, kitchen offices, and 
 bathroom. The upper floor contains Ave sick-rooms and the matron's bed- 
 room. All diseases, with the exception of scarlatina, for which a separate 
 cottage is provided, are treated in this building, and the medical officer con- 
 siders that the arrangement of the building lends itself admirably to the 
 purpose. 
 
 The sick-rooms give a floor space of IIG feet and cubic space of 1,820 feet 
 per bed, allowing two beds to each room. 
 
 Hitherto reference has been made chiefly to schools of the larger kind, 
 but it is equally essential, even in the smallest kind of school, as, for instance, 
 a private boarding school of only twenty or thirty pupils, to provide adequate 
 means of isolating a case of real or suspected infectious disease. This can 
 sometimes be done by setting apart a room or two on the top floor of 
 the building, or in a projecting wing, and contriving a separate staircase 
 approached only from the outside, T^yo rooms are, of course, better than 
 one, and a separate water-closet, and if possible a bathroom, ought also to be 
 arranged. This arrangement must, however, be regarded at best as but a 
 makeshifL. 
 
 Hospital pro^^sion is also required for children of the pauper class, 
 separate from the workhouses, such as those Avhich belong to metropolitan 
 and certain large provincial Poor-law imions. For schools of this class pro- 
 vision has to be made : (ft) for the isolation or quarantine of children on 
 their admission to the school, in order to prevent the introduction of any 
 cases of contagious disease into the general body of the school ; these are 
 usually called probation wards ; [b) for sick-wards for cases of ordinary non- 
 infectious ailments; and (c) for isolation wards for cases of infectious disease. 
 The probation wards should be more in the nature of an 'observation school,' 
 so to speak, than an infirmary ; for the children in them will be to a large 
 extent well and perfectly able to continue their education. It has been sug- 
 gested that, instead of each school being provided with its own probation 
 wards, a separate probation school should be made to serve for a group of 
 several schools, ' where sickly children, and children admitted in a state of 
 actual disease, should be kept for an indefinite time.' ' 
 
 The infirmary for ordinary sickness of a non-infectious nature should be 
 a separate building, removed from the noise and bustle of class-rooms and 
 playground, and amply provided with means of classifying the various diseases. 
 Such diseases as ringworm and other contagious disorders should be pro- 
 vided for here, carefully separated from all other diseases. 
 
 The isolation hospital for infectious diseases should provide means of 
 treating simultaneously at least two different infectious diseases. It should 
 be constructed in the same way as an ordinary fever hospital, and there 
 should be sufficient ground attached both for exercise for the convalescent 
 patients and for providing temporary increased accommodation by putting 
 up tents or huts to meet the demands of an epidemic. 
 
 The most serious clifficulty, however, wdth which the managers of these 
 large schools have to cope is the spread of ophthalmia. This disease, which 
 is one to which children of the pauper class are, for various reasons, exces- 
 sively prone, is Hable to spread from child to child in the most rapid fashion. 
 To prevent the introduction of ophthalmia into a school from outside is one 
 of the chief functions of the probation wards ; and it was mainly with a view 
 
 ' Report on Ophthalmia in the Metropolitan Pauper School. By E. Nettleship, 
 
 r.E.c.s. 
 
THE DWELLING 7G1 
 
 to the elimination of this disease that the suggestion referred to above was 
 made. 
 
 Ophthahiiia is, however, largely produced by the conditions under which 
 these large schools are carried on. And that this is the most important 
 part of the subject is proved by the fact that, according to the authority 
 before cited, ' the risk of getting ophthalmia is very far greater in the metro- 
 politan pauper schools than outside them.' ' It may, and in fact in one of the 
 large metropolitan schools it quite recently has become necessary to provide 
 for the accommodation of a large number of children suffering from ophthal- 
 mia. In the case referred to, the buildings are of a temporary nature ; but 
 it would probably be better to contemplate such a possibility as a large out- 
 break of the disease when arranging the plan of a large school, and to 
 provide at any rate a permanent nucleus to be increased when necessity 
 .arises by additions of a more temporary nature. 
 
 Ventilation and Wakming op Hospitals 
 
 Though, relatively, good ventilation is of more paramount importance 
 in a hospital ward than the mode of warming, the two are so intimately con- 
 nected, and in some cases so independent, that it is undesirable, if not 
 impracticable, to treat the one to the exclusion of the other. The object of 
 ventilation is to secure to each patient a constant supply of pure air, or air 
 of such purity as is attainable, in such a ratio that the air which he inhales 
 shall not be polluted beyond a given standard, either by his own or 
 other people's exhalations. It has been found in practice that every 
 adult requires a supply of 3,000 cubic feet of fresh air per hour in order 
 that the total impurity of the air may not exceed 0*6 per 1,000. In a 
 ^hospital ward, therefore, with a cubic space of 1,000 feet per bed the air 
 must be completely changed three times in every hour ; at which rate, if 
 the means of ventilation provide for steady and gradual movement of air, 
 the change will be effected without causing draught. In certain wards, as 
 those for fever and for acute surgical cases, at least double this amount of 
 air is necessary. The means adopted to provide this necessary movement of 
 air are commonly divided mto two classes — (1) natural and (2) artificial or 
 mechanical ventilation. 
 
 In the first class, or what is commonly known as natural ventilation, the 
 ■ agency of windows, simple shafts through the walls, and the extracting power 
 ■of open fireplaces is relied upon to produce the required effect. The par- 
 ticular form of windows best suited to hospital requirements and their posi- 
 tions in relation to each other is discussed elsewhere. Air may also be 
 admitted by so-called ' Tobin ' tubes, which are simply vertical tubes con- 
 nected at their lower ends with the open air, and with their upper ends open • 
 ing into the ward, and the object of which is to admit air in a vertical 
 direction ; air-shafts through the wall at the floor level, either with or with- 
 out movable shutters for closing ; or by similar shafts at the ceiling level. 
 Openings into the smoke flues or extraction shafts provided with flap valves 
 to prevent down draught are of course only useful as outlets for vitiated air. 
 The openings at the floor level should be placed behind the beds, and are 
 intended to effect a circulation of air at a part of the ward most liable to 
 stagnation. The openings at the ceiling level are accessory inlets to the 
 windows, and are frequently fixed permanently open. If properly protected 
 with ' hoppers,' they provide valuable means of ventilation when the windows 
 are shut. 
 
 > Nettleship, op. cit. 
 
702 HYGIENE 
 
 The special form of open fireplace most suitable for a ward need not here 
 be discussed in detail ; it will be sufficient to point out that a stove which is 
 provided with a supply of fresh air from without is preferable to one which 
 depends entirely upon the ward for its air for combustion. It is customary 
 in English hospitals to have fires burning in tlie wards all the year round, and 
 there is no doubt that the practice is very helpful to efficient ventilation. 
 
 Artificial ventilation may be roughly divided into two classes : (1) venti- 
 lation by extraction and (2) ventilation by propulsion. Strictly speaking, 
 the action of the chimney flue of an open fire is ventilation by extraction, 
 inasmuch as the extractive power of the flue depends on the expansion of the 
 heated column of air inside it. The two systems exist side by side at the 
 Lariboisiere Hospital, Paris, where one-half of the hospital is ventilated by 
 a system of propulsion, and the other by a system of extraction. In the 
 former system air is forced into the wards by means of a fan worked by a 
 steam engine, and is warmed by passing over steam pipes before entering the 
 wards. The vitiated air is by this system driven out through the outlet 
 shafts by the force of the entering stream of pure air. In the system of 
 ventilation by extraction the motive power is placed in a main extraction - 
 shaft, into which the various subordinate flues join, the power being a hot- 
 water stove, which by heating the air in the shaft causes it to expand, and so 
 draws the air from the wards through the various shafts. The fresh air enters 
 of its own accord to supply the place of the air drawn off into the outlet 
 shafts. In this system the warming is accomplished by means of hot water. 
 
 One of the most recent and probably most perfect systems of ventilation 
 applied to hospital wards is that adopted at the Johns Hopkins Hospital, 
 Baltimore. The wards here are contained in detached pavilions of one storey 
 and a basement. ' The basement is devoted entirely to heating and venti- 
 lating purposes, forming practically a large clean-air chamber containing the 
 hot -water coils for heatmg, and from which the air supply for these coils can 
 be taken when desired. Usually, however, the supply will be taken directly 
 from the external air. . . . Each of the wards has a separate aspirating 
 chimney, located in an octagonal hall or vestibule on the connecting corridor. 
 Into this chimney empties a foul-air duct, which runs longitudinally beneath 
 the centre of the floor of the ward, and which receives the air from lateral 
 ducts opening beneath the foot of each bed. The main foul-air trunk is of 
 wood, Imed Avith galvanised iron, and the lateral pipes are of galvanised iron 
 and cylindrical in shape. A similar duct is placed above the ceiling and 
 communicates with the ward by five openings in the ceiling in the longitudi- 
 nal central axis. Just above where this upper duct enters the chimney there 
 is placed in the shaft a coil to be heated by high-pressure steam when it is 
 necessary to quicken the aspirating movement.' ' It will be seen from the 
 foregoing description that the system adopted is one of extraction. The 
 position of the extraction outlets in the wards can be varied ; the air can be 
 taken out either at the floor level beneath the beds or from the centre of the 
 ceihng ; and it is intended to employ the former method in the winter, and 
 the latter in the summer. In the basement is placed a small propelling fan 
 connected with the heating coils, the function of which is to secure a thorough 
 air flush of the ward two or three times a day, and also to supplement the 
 aspirating shaft when occasion requires. This plan combines, therefore, the 
 two methods of propulsion and aspiration, though the ordinary method of 
 working is by aspiration only. 
 
 In most hospitals on the Continent mechanical means of ventilating the 
 
 • Ventilation and Heating. By John S. Billings, M.D., Surgeon-General, U.S. Army. 
 
TEE DWELLING 76a 
 
 wards are employed. The systena adopted at the Lariboisiere has been 
 described above, and may be taken as a fair example of French methods. In 
 Germany the use of * calorif^res ' is largely adopted ; these are large hot-air 
 stoves usually, as at Dresden, the furnaces of which are situated in the base- 
 ment, below the wards. The upper part of the ' calorifore ' is in the ward, and is 
 generally cased with porcelain tile. The fresh air is admitted in the basement 
 warmed by the furnace and ascends into the wards through the tile-incased 
 upper portion. In the summer the fresh air is frequently made to pass over 
 running water or ice on its way to the wards. In several of the newer 
 hospitals in Germany and France the ventilating appliances are much 
 simplified. At Halle, for instance, the windows and ventilating openings in 
 the roof are relied upon entirely ; while for the winter, when the cold is too 
 great to allow of the use of open windows, an arrangement is made by 
 which the vitiated air can be extracted through an underground flue, com- 
 municating with the furnace shaft of the boiler house. The supply of fresh 
 air is warmed before it enters the wards by passing over hot-water pipes. 
 
 The question of the relative value of natural as compared with artificial 
 ventilation is largely if not entirely a question of climate. Both on the 
 Continent and in America, it is considered that the very large variations of 
 temperature which occur demand the employment of mechanical aids to 
 ventilation. In America particularly the need for artificial ventilation is 
 much insisted on, not only for hospitals and other pubhc institutions, 
 but also for dwelling houses. Owing to the very great variations of 
 temperature, and to the extreme dryness of the air, especially in the 
 northern parts of the United States, it is necessary that a temperature of 
 from 68° to 70° F. should be kept up in dwelling rooms. In this country, on 
 the other hand, the variations of temperature are very much less, and the 
 relative humidity of the air permits of a much lower temperature being kept 
 up. It may, indeed, be safely afiirmed that there are very few days in the 
 average year when the weather is so cold as to compel the closing of the 
 windows in a hospital ward. It is therefore generally agreed that the 
 simpler methods are the most suitable for hospital purposes in this country. 
 
 There is, however, one purpose for which some well-devised system of 
 mechanical ventilation would seem to be desirable — that is for the wards of 
 small-pox hospitals. But the end to be aimed at is not only the ventilation 
 of the wards, but the complete destruction of all the air that is discharged 
 from the wards. The idea was first suggested by Dr. Burdon Sander- 
 son, F.E.S., in his evidence before the Eoyal Commission on Small-pox and 
 Fever Hospitals, of which he was a member. The plan proposed by Dr. 
 Sanderson consisted of an annular ward, with a central circular shaft for the 
 extraction of foul air. The beds were placed around the inner wall instead 
 of against the outer wall, as is usual in circular wards, and at the back of 
 each bed was placed an extraction opening. The windows were fixtures, and 
 openings for the admission of fresh air, having two square feet of area each, 
 were placed in the outer wall. The extracting power was to be a fan pro- 
 pelled by steam, and the air supply per patient 10,000 feet, moving at the rate 
 of one mile per hour. The air extracted by the fan was to be passed through 
 a furnace of which the heat should be supplied by gas. Upon this scheme 
 Dr. Billings commented thus. After pointing out that the beds would be more 
 conveniently placed if arranged against the outer wall, he says : — ' A second 
 objection is that the central shaft is unnecessarily large, as are also the inlets 
 into it. It is not desirable to reduce the velocity of the air at the outlets or 
 in foul-air ducts below four or five feet per second, because at very low 
 velocities a very slight thing will disturb the currents. The velocity at 
 
764 
 
 HYGIENE 
 
 the outlets has comparatively httle to do with the production of draiights. 
 There seems to be no necessity whatever for the use of an aspirating fan in 
 the plan proposed. If the air is to be heated to a temperature of 2D0° F. 
 and upward, which is necessary to secure its disinfection, this heat will in 
 itself furnish all the aspirating power required. The use of gas to produce 
 the heat required for such large quantities of air would also be unnecessarily 
 expensive ; a coal furnace would do the same work at half the cost.' ' Not- 
 Avithstanding these and some other shortcomings on points of detail touched 
 upon by Dr. Billings, the plan is valuable for its suggestiveness. That such 
 a mode of dealing with the infected air of a small-pox ward is practicable 
 there can be no doubt ; the question of the best mode of carrying it out is 
 one of detail and of by no means insuperable difficulty. 
 
 DEAINAGE OF THE DWELLING 
 
 In this section will be included the drainage arrangements and the fittings 
 in connection therewith, up to the point where the liquid refuse from the 
 house is discharged either into the sewer, cesspool, or system of irrigation ; 
 in other words, it will treat of the conveyance of sewage out of the premises, 
 but not of its ultimate disposal either by sewers, cesspools, or on to the land. 
 It will also concern itself exclusively with water-borne systems of drainage, 
 and not with any form of dry system. 
 
 The function of a drain is to convey to its destination with as much 
 dispatch as possible all the refuse or waste matter from a house that can 
 properly be carried away by the agency of water. To accomplish this object 
 aright, the drain should be made of such materials and of such a form as 
 to render it impossible for its contents to leak out, or for them to accumu- 
 late inside. In its form, therefore, in the nature of the material of which it is 
 made, and in the mode of laying, a drain must throughout its entire course 
 be such as to offer the least possible obstacle to the rapid progress of its 
 
 contents towards their 
 
 ,ll/..4/%.^#'.'!i'ff((((.('/a.f/ff/,. destination; it must 
 
 also be impervious both 
 as to the material of 
 which it is made, and 
 as to the joints between 
 its different sections. 
 Further, it is necessary 
 that the air in the drain 
 should not be allowed 
 to escape therefrom ex- 
 cept at such exits as 
 may be provided for that 
 purpose. A drain must 
 therefore be both air- 
 and water-tight. 
 
 Formerly drains 
 were commonly made of 
 brick or of slabs of stone, and were square in section. Drains of this kind are 
 still to be found in many places ; the example shown in fig. 146 was sketched 
 in 1887 in a Surrey village and in all probability exists to this day. The 
 defects of such a form of drain are obvious. In the first place the form 
 
 ' Ventilation and Beating, op. cit. p. 178. 
 
 Fig. 146. 
 
TEE DWELLING 765 
 
 itself is, of all forms, the one least adapted for facilitating the flow of water 
 along it. Secondly, a drain so constructed allows the contents to pass 
 readily through its sides into the surrounding earth. Brick drains with a 
 circular section are an improvement upon the square form, and may still be 
 found occasionally so well made and of such good materials as to be practi- 
 cally impervious, but they are usually much larger than necessary or desir- 
 able. Drains of this kind are, however, unsuitable for house drainage, inas- 
 much as the surface, however well they may be constructed, is comparatively 
 rough, and the material is liable to be affected by time and constant action 
 of running water. The brick drain commonly used before the introduction 
 of glazed pipes was, as a rule, made of ordinary bricks put together with 
 mortar. The action of the water and detritus carried with it on the soft 
 bricks and the mortar joints, aided by the operations of rats, soon reduced 
 these drains to something like the condition of a sponge ; and whenever a. 
 drain of this kind is removed, as they frequently are, from old houses in 
 London and elsewhere, the surrounding earth is found to be saturated with 
 sewage that has leaked out through the brickwork of the drain itself (fig. 14G). 
 
 The form of drain now most generally used is a circular pipe made in 
 lengths of about two feet of stoneware glazed with a salt glaze and provided 
 at one end of each length with a socket into which the other or spigot end 
 of the next pipe fits. Between the spigot end of one pipe and the surround- 
 ing socket of the next is an annular space, which is filled with some material 
 intended to make the joint watertight. The material in common use for this 
 purpose some twenty years ago, and still extensively used, is puddled clay^ 
 because where the pipes are carelessly laid on a defective foundation, sub- 
 sidences and settlements are certain to occur, and the clay would give with 
 the altered position of the pipes ; whereas if a harder material, such as cement, 
 were used for jointing these defectively laid pipes, breakages would be likely 
 to occur in the pipes, sockets, or joint. The clay, however, in the course of 
 a comparatively short time, will inevitably be washed out of the joints, and 
 for all the protection it affords might just as well have been omitted and the 
 pipes laid with open joints. Portland cement, if carefully applied, makes an 
 excellent and lasting joint ; but care needs to be taken to ensure that any 
 cement that squeezes out of the joint into the interior of the pipe is entirely 
 wiped off, or it will ' set ' and leave ridges inside that will form so many 
 obstructions to the flow of water, and lodging places for solid matters carried 
 down with the sewage. It is needful also to be certain that the cement is 
 properly applied all round the joint, as careless or dishonest workmen will 
 often make a neat joint so far as it is visible on the top of the pipes, while 
 leaving the underside entirely devoid of cement. Another kind of joint, which 
 has been much used of late years, is made by casting on to the spigot and 
 socket of each pipe a ring of specially prepared patent material, the two rings 
 being fixed in situ with a composition of Russian tallow and resin. This 
 joint will bear testing with water within a very much shorter time after its 
 completion than is the case with cement ; and there is, moreover, nothing to 
 squeeze up inside the pipe after the joint is made. It is, however, desirable 
 to make sure of its durability by adding a ring of cement outside the patent 
 joint. 
 
 Of not less importance than a watertight joint is a firm and sohd founda- 
 tion on which to rest the pipe. If a drain be laid in a soft and yielding bed, 
 subsidence will inevitably take place, with the result that the joints, if of 
 cement, will be broken, and the drain will cease to be watertight, while the 
 gradient will be rendered irregular and deposits of sewage will occur in the 
 drains. 
 
706 
 
 HYGIENE 
 
 Fig. 147. 
 
 If, therefore, tlie soil upon ^Yllicll a drain has to be laid is not of sufficient 
 solidity and compactness as to render all chance of subsidence impossible, 
 the pipes must be laid on a bed of concrete of such thickness as the nature of 
 the case demands, but never less than three inches 
 under the centre of the pipes. When the pipes have 
 been laid and tested the concrete should be filled in 
 around them up to the line of the horizontal dia- 
 meter (see fig. 147). 
 
 The fall or inclination to be given to a drain is a 
 point upon which no definite rules can be laid dowTi, 
 as the possible fall will always depend upon the cir- 
 cumstances peculiar to each case. It must, however, be premised that the 
 fall should be a regular one, and not, as is too often found to be the case 
 in carelessly executed work, that one pipe should have a fall of some two or 
 '-hree inches, the next be laid quite flat, and the next falling perchance the 
 reverse way. Having found the level of the starting point of the dram, and 
 the level of the outfall, the pipes should be laid with an even fall from point 
 to point. What the fall is to be must, as has been said, depend upon circum- 
 stances ; but it may be taken as a general rule that a house drain should 
 have a fall of at least 1 in 50. When the fall obtainable is less than 
 this, the scouring or cleansing of the drains cannot be effectually accom- 
 plished without the aid of special flushing, of which further mention will be 
 made hereafter. 
 
 The following table ^ of the discharge per minute of various sizes of drains 
 when running full will be found useful : — 
 
 
 Velocity 3 feet per 
 second 
 
 Velocity 4i feet per 
 second 
 
 Velocity 6 feet per 
 second 
 
 Velocity 9 feet per 
 second 
 
 Diameter 
 of pipe 
 
 
 
 
 
 1 
 
 FaU 
 
 Discharge 
 
 per 
 
 minute 
 
 Fall 
 
 Discharge 
 
 per 
 
 minute 
 
 Fall 
 
 Discharge 
 
 per 
 
 minute 
 
 Fall 
 
 Discharge 
 
 per 
 
 minute 
 
 Inches 
 
 
 Gallons 
 
 
 Gallons 
 
 
 Gallons 
 
 
 Gallons 
 
 3 
 
 lin 69 
 
 54 
 
 lin 30-4 
 
 81-0 
 
 1 in 17-2 
 
 108 
 
 1 in 7-6 
 
 162 
 
 4 
 
 lin 92 
 
 96 
 
 lin 40-8 
 
 144-0 
 
 1 in 23-0 
 
 192 
 
 1 in 10-2 
 
 288 
 
 6 
 
 1 in 138 
 
 216 
 
 lin 61-2 
 
 32 -0 
 
 1 in 34-5 
 
 432 
 
 1 in 15-3 
 
 648 
 
 9 
 
 1 in 207 
 
 495 
 
 lin 92-0 
 
 742-5 
 
 lin 51-7 
 
 990 
 
 1 in 23-0 
 
 1,485 
 
 12 
 
 lin 276 
 
 876 
 
 1 in 122-4 
 
 1314-0 
 
 1 in 69-0 
 
 1752 
 
 1 in 30-6 
 
 2,628 
 
 The size of pipes to be employed is also a matter which must depend on 
 circumstances. As a rule, house drains are frequently laid with pipes of 
 much too large diameter ; and unfortunately many local authorities are apt 
 to insist upon the use of the larger pipes, on the plea that the smaller ones 
 are more readily choked. If drains are always to be laid in the old careless 
 and haphazard way, there is some justification in the argument ; but as the 
 object of good drainage is to render the occurrence of a stoppage impossible, 
 there is no need to unduly increase the area of pipe surface which has to be 
 flushed and the capacity which has to be ventilated. Drain pipes are made 
 usually in three sizes— of 4 in., 6 in., and 9 in. diameter. The area of a 4-in. 
 pipe is 12-56 inches, while that of a 6-in. pipe is 28-27 inches, or considerably 
 more than double that of a 4-in. pipe ; while a 9-in.pipe has a sectional area 
 of 63-61 inches. The same amount of water, therefore, that would fill a 4-in. 
 
 ^ From A Handbook of House Sanitation. 
 London, 1882. 
 
 By E. F. Bailey-Denton, C.E., B.A. 
 
THE DWELLING 
 
 767 
 
 pipe would not nearly half fill a 6-in. pipe ; consequently the flushing power 
 of the same volume of water is proportionately reduced. As a general rule, a 
 4-in. pipe is sufficient for the drainage of moderate- sized houses, a 6-in. 
 will suffice for a large mansion, while D-in. pipes are only needed for the main 
 and outfall drains of large institutions. 
 
 No drains ought to be laid under houses when ili is possible to lay 
 them outside. In some instances, however, as in houses m terraces or 
 streets of towns, the drains must pass under the house in order to reach the 
 sewer. In such cases extra precautions are necessary to prevent the leakage 
 of air or water into the soil under the house. A good plan is to use iron 
 instead of stoneware pipes, one advantage of which is that there are fewer 
 joints to make, the pipes being cast in 10 or 12 feet lengths instead of 
 2 feet ; and the joints can be securely caulked with lead. In any case the 
 pipes, whether they be of stoneware or of iron, should be completely encased 
 in concrete. 
 
 The paramount necessity for the greatest accuracy in laying out a system 
 of drainage can hardly be too strongly insisted upon. Absolute precision 
 not only in designing the scheme, but in carrying it out to its smallest details, 
 
 Pig. 148. 
 
 is as important in the drainage of a house as it is in the sewerage of a town. 
 Unfortunately, however, while the highest engineering skill is brought to 
 bear on the wholesale disposal of the sewage of a large community, the 
 details of drainage to individual houses are too often entrusted to the 
 unskilled hand of a builder's foreman. 
 
 The plan upon which the drains of a house are laid is also a matter which 
 requires careful consideration. Provision should be made for ready inspec- 
 tion of every part of the drains, without its being necessary to dig out the 
 ground or tear up floors. This can only be done effectually if the drains are 
 laid out in straight lines from point to point, and if, at each change of direc- 
 tion or junction between two or more pipes, an access chamber or manhole 
 is built. The old-fashioned plan of laying drains in all sorts of directions, 
 using curved lines by preference where straight lines would have better 
 accomplished the purpose, is now very generally abandoned. Examiales of 
 good and bad plans of drainage are given at figs. 148 and 149. An access 
 
768 
 
 HYGIENE 
 
 chamber or manhole is formed by building a square pit of sufficient size to 
 permit of a man getting down into it to examine the drain. At the bottom 
 of the pit the main drain runs through in a glazed channel or half-pipe, and 
 the branch pipes all deliver either on to the main channel or at the same 
 level, and are formed of similar half-pipes curved on plan (figs. 150 and 151). 
 
 Fig. 149. 
 
 The top of the manhole is covered with a hinged iron lid, which should have 
 an air-tight joint (fig. 151). 
 
 With such a system of drainage, having practically free access to every 
 part, the application of any test desired is rendered very simple. 
 
 All drains should be tested when complete in order to ascertain if they 
 
 Fig. 150. 
 
 fulfil the required conditions of soundness. This is most effectually done by 
 plugging the lower end, and filling the pipes with water, which should be 
 allowed to stand for such a time as experience will suggest before the drain 
 is passed as complete and perfect. The water test is a very severe one, 
 
THE DWELLING 
 
 769 
 
 especially in long lengths of drains and where the fall is great, and will 
 infallibly detect any faulty places either in pipes or in joints. Pipes can 
 now be had which have been submitted to hydraulic pressure and which are 
 marked ' tested ; ' a great advantage to the builder, as the makers undertake 
 to replace any pipes which prove defective under test when laid and jointed. 
 
 Traps are appliances used for the purpose of keeping back the sewer air 
 from the drains or the drain-air from the house or its surrounding air ; and 
 the method by which the air is kept back is by the interposition of a body 
 of water, called a ' water seal,' between the inlet to, and the outlet from, the 
 trap. 
 
 A form of trap which was almost universally used in former times, and is 
 a,t times met with now, is what is known as a ' mason's ' or ' dip ' trap. It 
 consists (fig. 152) of a square chamber divided across the middle by a vertical 
 slab of stone which extends up to the top but stops short of the bottom 
 sufficiently to allow the sewage to pass from the first into the second division. 
 These dip traps are often found with a very considerable space between the 
 bottom of the dip-stone and the floor of the chamber ; the result of which 
 
 Fig. 151. 
 
 arrangement is a very considerable accumulation of solid refuse on the floor. 
 At best this form of trap is a most defective one, and becomes a small cess- 
 pool, or storage tank, for decomposing organic matter. 
 
 The only suitable kind of trap to be used for cutting off the house 
 drain from the sewer or cesspool is what is known as a ' siphon ' trap. It 
 is in reality not a siphon at all, but a pipe bent in such a way that there is 
 always a water seal between the inlet and the outlet. There are several 
 forms of trap suitable for the purpose ; the one shown in fig. 153 was devised 
 by Mr. Eogers Pield, C.E., specially for fixing in connection with manholes, 
 and has at its inlet a short piece of open channel or half-pipe. The points 
 to be observed about a trap for this purpose are that its parts shall be so 
 formed as to facilitate the thorough scouring out of it when there is a flow 
 of water through the trap ; a slight dip at the inlet, which should be well 
 rounded, also tends to add force to the water at its entrance. 
 
 A modification of this trap (fig. 154) has been devised by Professor Cor- 
 field with a view of giving greater effect to the scour of water through it by 
 making the channel at the entrance to the trap somewhat of an egg-shape ; 
 but in this modified trap an arrangement has been contrived so as to form a 
 bye-wash through the arm of the trap provided for affording access to the 
 VOL. I. 3d 
 
770 
 
 HYGIENE 
 
 Fig. 152. 
 
 drain below the trap. This bye-wash is furnished with a plug-valve having 
 a chain or rod attached to it and brought up to the top of the manhole so 
 that, in the event of a stoppage occurring in the trap and the manhole be- 
 coming in consequence filled with sewage before the stoppage is discovered, 
 
 the bye-wash can readily 
 bo opened to allow the 
 sewage to pass away until 
 the level of the bye-wash 
 is reached, when access to 
 the trap can more readily 
 be obtained for removal of 
 the obstruction, and thus 
 the necessity for pumping 
 or baling out the manhole 
 is removed. 
 
 To receive the surface 
 water from yards and other 
 paved places, gulley traps 
 are used. These traps 
 should be as simple in con- 
 struction as possible, and 
 should certainly not be of 
 the form known as ' bell 
 traps.' In this trap (fig. 
 155) there is a fixed part 
 which contains in the cen- 
 tre the open mouth of the 
 pipe around about which 
 is an annular space to 
 hold water, and a movable 
 part which consists of a 
 grating and an inverted 
 cup or 'bell.' The edges 
 of the cup dip into the 
 water contained in the 
 annular space, and so form 
 a water seal. The defects 
 of this trap are that the 
 water seal is very shallow, 
 often not exceeding a quar- 
 ter of an inch in depth, so 
 that a very small amount 
 of evaporation suffices to 
 unseal the trap, and the 
 movable part is apt to get 
 removed or broken Avhen 
 the protection of the water 
 seal, such as it is, van- 
 ishes. 
 
 For ordinary purposes, and where the water washed into the trap is not 
 liable to be charged with sand or other solid matters to any great extent, 
 a suitable form of trap is that shown in fig. 156 ; but where such sohd 
 matters are likely to be present m considerable quantities, a trap made as 
 in fi». 157 with a receptacle for mtercepting the silt &c. is more useful. 
 
 Fig. 153. 
 
 3Aj^3^— -^^^g 
 
THE DWELLING 
 
 111 
 
 Fie. 155. 
 
 Fig. 156. 
 
 The bucket is made of iron and has a handle for lifting it out, and the sur- 
 face both inside and out should be tarred and sanded to protect it from rust. 
 To prevent the passage of drain-air into a house by way of the waste- 
 pipes of such iittings as 
 sinks, baths, and lava- 
 tories, it is necessary to 
 cause such waste-pipes 
 to be absolutely sepa- 
 rated from the drains 
 and to deliver in the 
 open air over trapped 
 guUeys. In the model 
 bye-laws issued by 
 the Local Government 
 Board for the guidance 
 of local sanitary autho- 
 rities it is provided that 
 an open channel shall 
 intervene between the 
 end of the waste-pipe 
 and the trap, and that 
 the interval between the 
 pipe and the trap shall 
 be at least 18 inches. 
 The object of this fur- 
 ther provision is to 
 make the break in the 
 continuity of the waste- 
 pipe and the drain 
 greater, and so to lessen 
 the possibility of foul 
 air passing from the 
 gulley into the waste- 
 pipe, and also to render 
 the end of the waste- 
 pipe more accessible for 
 cleansing purposes. For 
 it must always be re- 
 membered that a pipe 
 through which greasy 
 water is constantly 
 passing, as is the case 
 both with scullery- sink 
 wastes and. lavatory 
 wastes, is Hable to be- 
 come very foul with 
 grease and soap and to 
 require periodical clean- 
 ing. For this reason 
 it will be seen, when the 
 inside fittings come to 
 be discussed, it is always desirable 
 itself. 
 
 The trap into which waste-pipes 
 
 Pig. 157. 
 
 to have a trap upon the waste-pipe 
 
 from smks discharge 
 
 should be 
 3d 2 
 
 as 
 
772 
 
 HYGIENE 
 
 Fig. 158. 
 
 shallow as it can be made consistently with the provision of a sufficiently 
 deep water seal, so that the body of water contained in it may be reduced 
 as much as possible in bulk. A suitable form of trap is shown at fig. 158. 
 
 While the necessity for traps in proper places must not by any means 
 be overlooked, it is equally necessary to guard against the undue multi- 
 plication of traps or the fixing of them in places where they are not required. 
 For the existence of a trap necessarily means a certain check upon the velocity 
 of the flow of water in the drains, and every trap which is not absolutely 
 needful is an obstruction to the passage of sewage. Traps at the feet of 
 soil-pipes, for instance, are not only unnecessary, but positively harmful, for 
 they prevent the free flow of air up from the drain through the whole 
 length of the soil-pipe which is so necessary a part of the ventilation of 
 drains. 
 
 The practice of closing or sealing up traps which receive the ends of rain- 
 water and waste-pipes is one which is at variance with good sanitation. 
 
 When a trap is closed up, as in fig. 
 159, it is not only difficult to get at 
 it when required for cleansing pur- 
 poses, but any foul or decomposing 
 matter retained either in the trap- 
 ping water or against its sides will 
 pollute the air in the waste-pipe 
 and, of course, also that of the 
 building. 
 
 The regular and effectual scour- 
 ing of drains depends, as a rule, 
 upon the water which is discharged 
 into them from water-closets, baths, 
 and sinks — the water, in fact, which 
 is used for the various domestic 
 purposes in the daily life of the 
 household. It is desirable, where 
 it can be arranged, to supplement 
 this by tanks provided for the ex- 
 press purpose of flushing out the 
 drains with a larger body of water 
 than ordinarily passes away from 
 the houses through the various 
 fittings ; and where the drains 
 have but slight fall some provision of the kind becomes a positive necessity. 
 It is further desirable that the action of these tanks should be automatic, 
 and for this purpose the annular siphon devised by Mr. Kogers Field, 
 M.I.C.E., is most valuable. This apparatus (fig. 160) consists of a siphon 
 the longer arm of which is placed within the shorter arm ; the siphon is 
 fixed in a tank in such a way that the longer arm passes through an open- 
 in» in the floor and dips into a small body of water kept in place by a weir, 
 and the shorter arm is kept clear of the floor to allow of the passage of water 
 between the two. When the tank is filling, the water rises simultaneously 
 within it and up the annular space in the siphon. When it reaches the top 
 of the lower arm it is directed by a projecting lip towards the centre, and 
 in its descent carries with it sufficient air to form a partial vacuum and 
 thus start the siphon. These tanks are sometimes used also to collect waste 
 water from sinks, baths, and lavatories, and so to concentrate, as it were, the 
 flushing power of the water which would otherwise pass away in small 
 
 
 Fig. 159. 
 
THE DWELLING 
 
 m 
 
 discharges. The siphons can be made in many different sizes and appHed 
 to tanks of from twenty gallons capacity upwards. 
 
 The pipes hitherto discussed have for the most part been those which 
 are fixed below the ground ; there are, in addition, some pipes, such as rain- 
 water pipes and soil-pipes, which are fixed vertically against the outside walls, 
 and for which the materials ordinarily used for underground drains are 
 unsuitable. Eain-water pipes are usually made of iron, lead being used only 
 in the most expensive works, and where elaborate and ornamental work is 
 required. Cast iron is for all practical purposes a sufficient and suitable 
 
 INSPECrWH SHAFT. 
 
 ROAD. 
 
 Fig. 160. 
 
 material for rain-water pipes. The pipes should be round, and should be 
 fixed so that there is a free space of at least one inch between the pipe and 
 the wall. The object of this is, first, that if a stoppage or a crack occurs in 
 the pipe, as possibly may happen after frost, the water which leaks out of 
 the pipe will not run down the wall and so cause dampness therein ; and 
 secondly, in order that the pipe can be painted all round. 
 
 For soil-pipes unquestionably the best material is lead. The pipe should 
 be of the kind known as ' drawn,' in long lengths, made without seam 
 and the lead of which it is made should weigh 8 lb. to the superficial foot. 
 
774 HYGIENE 
 
 which is equal to about "136 in. in thickness. All the joints should be soldered 
 and the pipe should be supported by properly made ' tacks ' (or flaps of lead 
 fastened to the back of the pipe) to the walls. Every soil-pipe should be 
 connected directly to the drain, and should be carried up its full diameter as 
 a ventilating pipe to a suflScient distance above the heads of all neighbour- 
 ing windows. Opinions difl'er as to the best means of finisliing the open 
 end of a ventilating pipe, some authorities being in favour of cowls, while 
 others consider that a simple open mouth is equally efficacious. The 
 extracting power of the best cowls is certainly doubtful ; and an efficient 
 protecting cap may be made by widening out the mouth of the pipe to about 
 twice its area, and fixing on it a spherical wire grating to keep the aperture 
 free and open. 
 
 Waste-pipes from fittings on upper floors must also be connected to 
 vertical pipes fixed outside the walls. These pipes should also be made of 
 lead, and where hot water is hkely to be discharged, the joints should be 
 made to allow of expansion and contraction. These pipes should be venti- 
 lated, and the ventilating pipes carried up above the windows. 
 
 Ventilating pipes, whether for soil- or waste-pipes, need not be made of 
 the same weight of material as the pipes they ventilate. 
 
 Cast-iron pipes, unless made of very heavy metal and provided with 
 sockets strong enough to bear caulking with lead, should never be used for 
 soil-pipes. The ordinary rain-water pipes so commonly used with the joints 
 made of red lead are never air-tight as a soil-pipe should be. 
 
 The practice of discharging waste-pipes into rain-water heads is not to be 
 commended. The inside of the head affords a lodgment for grease and 
 becomes often very foul, and a source of nuisance very perceptible at the 
 neighbouring windows. 
 
 Where it can possibly be avoided, soil-pipes ought never to be fixed inside 
 a building. The common practice of fixing the soil-pipe in a chase in the 
 wall, and then casing it over with a wooden casing, is a very bad one, and has 
 been the cause of much evil. It has frequently happened that on investi- 
 gating the cause of some serious leakage of drain air inside a house the evil 
 has been traced to a hole made by a carpenter in driving a nail right through 
 the pipe when fixing some piece of woodwork. Neither is it permissible to 
 make one pipe do the double duty of soil- and rain-water pipe. In the first 
 place, if this is done the rain-water pipe cannot properly be disconnected at 
 its foot as it ought to be ; and secondly, when the rain-water pipe is running 
 full or nearly full of water during a storm, its function of ventilating the soil- 
 pipe is necessarily in abeyance, and that at a time when it is most needed. 
 
 Water-closet apparatus may be divided into four classes : — (1) Those of 
 the ' hopper ' or ' wash-out ' kind, which are simply basins with traps of 
 earthenware, and which are flushed either by a waste-preventing cistern or 
 by a valve fixed in the supply cistern; (2) pan closets; (3) valve closets ; 
 and (4) trough closets. The first three of these classes have been fully, 
 described in the earlier pages of this article, and it is here only necessary to 
 describe the trough closet, which is an apparatus specially suited for outdoor 
 purposes to public institutions (workhouses, schools, prisons, barracks, &c.), 
 and to latrines in public places. It consists of a trough, made either in iron 
 or in glazed earthenware, with a weir at the outlet end for the retention of 
 a sufficient body of water in the trough, and a flushing cistern at the upper 
 end. The trough should be round in section and should be slightly inclined 
 towards the outlet, and the capacity of the flushing tank should be propor- 
 tionate to the length of the trough, and should be automatic in its action. In 
 most pubUc institutions, but especially in schools, it will be necessary to 
 
THE DWELLING 
 
 115 
 
 provide a grid at the outlet end, to prevent sticks or other things improperly 
 thrown in from passing into the drain. A siphon trap should be fixed at 
 the outlet end. 
 
 Urinals are more than any other apparatus the cause of nuisance from 
 the difficulty experienced in keeping them clean. This difficulty invariably 
 arises from an insufficiency of water. Urine, unless it is very copiously 
 diluted, very quickly deposits its salts upon all the surfaces with which it 
 comes in contact. One of the most successful forms of urinal recently 
 introduced consists of an earthenware trough formed and flushed very much 
 in the same way as a trough water-closet — with a shallower channel at the 
 floor, also constantly flushed. In this apparatus the urine is received into a 
 large body of water, which is periodically renewed from the flushing cistern, 
 and then there is little or no chance of the surfaces being corroded. In all 
 forms of urinal, whether for pubhc or private use, it is important to provide 
 that the urine is discharged into a large body of water, and that regular and 
 automatic flushing is applied to the floor surface immediately under the basin 
 or trough. 
 
 Sinks. — The particular form and material best suited for a sink is 
 scarcely a matter which affects health conditions ; but in all sinks the con- 
 struction and destination of the water-pipe is hygienically a matter of great 
 importance. 
 
 The mode in which the waste-pipe should discharge outside the house 
 has already been described. It is not, however, sufficient to cause the waste- 
 pipe to pass straight from the outlet of the sink into the open air. In most 
 sinks, especially the scullery ones, a large quantity of grease is carried down 
 with the water, and part of this is retained in the waste-pipe and becomes 
 very offensive, and the smell is driven into the house by the cold air passing 
 up through the open pipe. To remedy this a lead trap should be fixed im- 
 mediately under the sink ; and it should be provided with a screw cap either 
 at the bottom or at the side for cleansing purposes. 
 
 In order to prevent the grease, which forms so large a part of the refuse 
 water sent down from kitchen or scullery sinks, it is frequently collected in 
 large tanks called grease traps. The advantage of this arrangement, espe- 
 cially in town houses, where the question of disposal of the grease is by no 
 means an easy one, is open to doubt. A better plan would seem to be to 
 provide a flushing tank whose contents should be automatically discharged 
 with the trap which receives the water-pipe. By this means the grease is 
 broken up and carried clear away by the force of water behind it, and has no 
 chance of settling and clogging 
 the drains. 
 
 If it is thought desirable 
 to collect the grease instead of 
 discharging it into the drains, 
 a tank made of vitrified stone- 
 ware or glazed fireclay pro- 
 vided with a movable air- 
 tight cover should be used. 
 The water from the sinks 
 should be discharged through 
 a pipe dipping a few inches 
 below the level of the stand- 
 ing water, and the outlet pipe at the opposite end of the tank should be 
 arranged in a similar manner. The grease as it congeals rises to the 
 surface of the water and can then readily be removed. The inlet arm of 
 
 ■VM.».^.^'AV^kV^^VKVk'.VSVVV^V.k>.>JAV'>JJJ.V^^^^ 
 
 Fig. 161. 
 
776 HYGIENE 
 
 the tank should have a pipe brought up to the surface for ventilation. 
 In order to empty the whole contents of the tank into the drain, an outlet is 
 formed in the bottom provided with plug and washer and connected with 
 the drain by a pipe. 
 
 TJie Examination and Testing of existing Drainage. — In examining the 
 drainage and other sanitary appliances of a house, recourse must often be 
 had to several modes of testing. Drains underground, for example, must be 
 tested to ascertain if they are air- and water-tight, and this fi-equently has to 
 be done without disturbing the ground. Vertical pipes must also be tested 
 as to soundness, and the same test that is applied to an underground drain 
 cannot always be applied to a vertical lead or iron pipe. 
 
 The tests most commonly applied to ascertain the condition of pipes are 
 water, smoke, and oil of peppermint. The water test consists of filling the 
 pipes with water, the lower end having first been securely plugged. This is 
 the most severe test that can be applied, and any drain that stands the 
 pressure thus applied may unhesitatingly be x^ronounced sound. The water 
 test can rarely be applied in old houses unless — which is seldom the case — a 
 manhole exists near the lower end of the drain, or it is possible to open the 
 ground. 
 
 The smoke test can be applied either with the aid of a pumping apparatus 
 or by inserting a ' di'ain rocket ' into the course of the drain. Either of these 
 methods can usually be applied without opening the ground or disturbing the 
 pipes, but where the di'ain to be tested is underground, and covered over with 
 earth and stone, or cement paving, the smoke test often fails to reveal defects 
 which are readily detected by the water test. Smoke is specially useful for 
 testing vertical pipes, and for tracing the source of smells arising from defects 
 in pipes which are hidden in walls or behind casings. 
 
 Oil of peppermint is useful for detecting leaks in soil-pipes or in drains 
 where they are under wooden floors and close to the surface ; but when once 
 it has been applied its smell is so pungent and penetrating that no second 
 test can be made with it. 
 
 In examining the condition of the dramage and other sanitary appHances 
 of a house, the first process is to ascertain, as nearly as possible, the general 
 line of the drainage. Assuming that no manholes or inspection chambers 
 are in existence, it will be necessary to dig down to the main drain and open 
 into it. The existence or not of a disconnecting trap between the drain and 
 the sewer must next be ascertained, and if a trap exists it is necessary to 
 ascertain its form and construction. The next step is to test the main drain, 
 either with water or smoke, to ascertain if it be water-tight. How this 
 is to be done must depend upon circumstances. Should the test applied 
 point unmistakably to the existence of leakage, the drain should be uncovered 
 for its whole length, and the defective parts traced. All junctions should 
 then be carefully examined. The vertical pipes will then be tested, care 
 being taken when testing a vertical pipe with smoke to cover up any open 
 ends. The waste-pipes from sinks, baths, lavatory basins, and safes under 
 closets should next be examined, and note made of any such pipes which 
 are directly connected with drains or soil-pipes. The overflow-pipes from 
 cisterns must be traced, and the supply-pipes to water-closets investigated. 
 Overflow-pipes are not unfrequently connected to soil-pipes, and the water 
 supply to a closet apparatus is often fomid to be laid on direct from the cistern 
 which supphes drmking water. 
 
HOSPITAL HYGIENE 
 
 BY 
 
 H. G. HOWSE, M.S. 
 
 SURGEON TO GUT'S HOSPITAi 
 
HOSPITAL HYGIENE 
 
 In former days a permanent unwholesomeness of greater or less degree was 
 Jaeld to be a normal condition of hospitals inseparable from the aggregation 
 •of sick persons, and so generally did this view prevail that the word ' hospi- 
 talism ' was actually used to express this thought, as if the circumstances of 
 hospital life were necessarily prejudicial rather than favourable to the main- 
 tenance of health. 
 
 Experience has shown that this condition, if it be found in our time in any 
 institution devoted to the sick, arises from one of two causes, or from both : 
 -either from the defective planning or construction of the building, or from mis- 
 management in its use; for it is possible, by errors in its administration, for 
 any hospital, however well designed, to become prejudicial to its inmates, 
 who are usually peculiarly susceptible to unhealthy influences. 
 
 The details of hospital construction and constructional arrangement of 
 wards will not be dealt with in this article, but in that headed ' Hospitals 
 and Pubhc Institutions,' p. 718 ; it is proposed here to deal with minor details 
 
 • of ward-working. 
 
 Floor Cleaking 
 
 The material of the floor of a ward should be some fairly hard wood, 
 prepared so as to be non-absorbent. Oak is one of the best woods, but 
 
 "it is very expensive ; teak is also valuable for the purpose, but is Httle, 
 if any, less expensive, and, though easier to work, is not quite so hard 
 
 . as oak. The planks forming these hard- wood floors should be dovetailed 
 into each other, or tongued and grooved, as in parquet floors, so that there 
 may be no interval in shrinking between the planks. It is best, if it can 
 possibly be managed, to keep the wood which is to form the flooring of 
 these rooms for two or three months in the room where it is to be laid, so 
 that all drying and shrinking may take place before laying the floor. This 
 is not often practicable ; but, in any case, thoroughly dried and shrunk wood 
 should be used, and the method of tongued and grooved floors gives good 
 results. They are not, however, easy to remove in case of necessity, when 
 
 . gas tubing, &c., runs beneath the floor. This must be specially provided for by 
 the planks being screwed simply into the joints over the pipes. In whatever 
 way the junction of the planks is effected, it is important that there should be 
 
 .no space between the planks leading to the interval between the joists and 
 the ceiling of the room below. Hard-wood floors, after laying, should be 
 planed down level and then well sand-papered, using abundance of sand- 
 paper. The fibre may then be further consolidated and rendered waterproof 
 by using pretty freely over the surface a solution of shellac in spuit. This 
 should be repeated two or three times, rubbing down with sand-paper between 
 
 • each application. This produces an exceedingly hard, durable, and water- 
 proof floor, which is as dust- and germ-proof as it is possible to make it. 
 
 Deal is, however, the commonest material of which the floors of hospital 
 wards are constructed, both on account of its price and of its ease of working. 
 It is therefore necessary to consider the best mode of treating it in all the 
 - hospitals in which it already forms the material used. 
 
780 HYGIENE 
 
 If the better forms of deal be used, not much objection can be raised to 
 it, especially if some special modes of preparation and hardening are made 
 use of. The inferior and softer kinds of deal are objectionable, in that they 
 become exceedingly porous and absorbent after much washing, and thus 
 afford a basis for absorption of decomposing discharges, and even of foul 
 odours. 
 
 As a rule, in our hospitals much too little attention is paid to the condi- 
 tion of the floors. If deal be used, it commonly shrinks considerably for 
 some time after it is laid down, even when the quality of the wood is good, 
 leaving long fissures between the planks. These fissures at first allow a 
 great accumulation of dust, dirt, and flue to collect between the boards and 
 the ceiling of the room below ; and this can never be got at and removed. 
 If the fissures remain open, this dust is liable to be blown up into the ward 
 in a high wind, if the space below the flooring is properly ventilated (for the 
 prevention of dry rot). This dust is often a means of re-infection, after the 
 closure and most careful cleansing and painting of a ward. Gradually, how- 
 ever, after a considerable lapse of time these fissures tend to become closed, 
 at any rate in all the more trodden parts, by a collection of dirt and debris 
 in them. This is only a less objectionable condition than the open state, if 
 the flooring be regularly washed. The collection of dirt in them, being con- 
 tinually wetted, forms a nidus of germ-growth which cannot but be regarded 
 as undesirable. These fissures should be stopped in some way within three 
 or four years of the first laying down of the floor (or at a later period) 
 with some non-absorbent material. This is best and most easily done by thin 
 strips of wood laid and glued into the fissures. If the flooring has been 
 stained and polished from the first, the fissures will probably have been 
 closed by cement worked into them. This cement is usually some form of 
 putty of the same tint as the flooring, and mixed with the same gum- 
 resinous varnish as that used for the floor. This is good, if the fissures be 
 small ; but when they become wide and gaping, the cement should be cleaned 
 out and strips of wood substituted. 
 
 As far as the healthy condition of the ward is concerned, the writer 
 believes that the stained and polished floor is far better than one which has to 
 be continually washed. Objection is occasionally raised that the cleansing 
 of such polished floors is a process of ' rubbing the dirt in.' There is not 
 much force m the objection. A properly prepared polished floor leaves little,, 
 if any, space for ' rubbing dirt in.' And the writer, for his part, would far 
 sooner do operations in a ward of which the flooring is kept clean and 
 poUshed than in one where the cleanliness is obtained by continual washing. 
 
 In the preparation of a deal floor for staining and polishing, after filling 
 aU the cracks and fissures vnth strips of wood and cement, it should be well 
 rubbed down with abundance of sand- or glass-paper. This process adds 
 very much to the hardness of the floor. In doing it, minute particles of the 
 sand or glass get rubbed off and embedded in the woody fibre. ^ If, now, this 
 
 ' It is not generally known how very much this adds to the hardness of a wood. In 
 wood turned and polished with sand-paper on the lathe, if any ornamentation has to be 
 afterwards added, it is found that wood so polished takes oS the edge of the fine-steel 
 tools used in the process very much more quickly than the original wood, on account of 
 the particles of silica embedded in the fibre. 
 
 Some years ago the floors of the wards in Guy's Hospital were cleaned with sand. 
 This was good for the boards, but it had to be given up, because with the open fissures be- 
 tween the boards such a quantity of sand gradually accumulated on the top of the ceiling 
 below, that sooner or later the ceiling gave way from the weight, and fell in great pieces into 
 the ward below. With tongued and grooved flooring, however, this need never take place. 
 It is probable that the sand-scrubbed flooring of the past generation was much more- 
 
HOSPITAL HYGIENE 781 
 
 surface be brushed over once or twice with a solution of shellac in spirit of 
 wine, and in the interval between each application rubbed again with fine 
 sand-paper, it will be found that even deal can be so much hardened and 
 rendered so resisting as to become a very durable material. 
 
 Such floors, whether they are of deal or hard wood, may be polished and 
 Tiept clean by being rubbed with a mixture of turpentine and beeswax (in 
 the proportion of one pint to a quarter of a pound, melted together). But in 
 the case of deal, it is well occasionally to repeat the application of the 
 spirituous solution of shellac, say, once a year, so as to maintain the fibre of 
 a proper degree of hardness. 
 
 Walls 
 
 The walls of a ward should be of hard plaster, capable of being well rubbed 
 •down and polished. No inequalities or cracks should be allowed to exist. 
 The surface of the wall should be painted, so that it can be periodically 
 washed, the paint being left with its oil (i.e., shiny) surface, and not ' flatted.' 
 'Or it may be covered with a coat of varnish. The cornice mouldings should 
 be of the fewest and most simple description, or altogether absent, so as to 
 present as few angles and recesses for the lodgment of dust as possible. If 
 wood wainscoting or panelling is used, it should be of hard wood, and should 
 be of the simplest possible description, with plain or rounded surfaces, and as 
 few angles as possible. The surface should be treated in the same manner 
 as that already given for the flooring. With the exception of the skirting 
 board, which saves the wall from breaking low down from careless blows, 
 wood is a very doubtful material for the construction of the walls, unless 
 used absolutely plain. The tendency always is to ornament wood used in 
 the construction of a wall, either by panelling or even carving, and this is not 
 advisable. 
 
 The surface of a polished plaster wall should be washed down periodically 
 {at any rate, once in three months) with warm soap and water. If there 
 have been any doubtful cases in the ward, it is well to use a solution of 
 carbolic acid (about 1 in 30) instead of, or in addition to, the soap and 
 water. If it can possibly be managed, it is well to apply one thin coat of 
 paint once a year. This is better than allowing a longer time to elapse and 
 then applying two or three coats at once. It keeps the walls and wood- 
 work in better condition, and provides for the stopping of any cracks or fissures 
 ■which may be appearing. 
 
 The same principles should be applied as regards any pictures or other 
 ornaments hung on the walls. As a rule, pictures, brackets for statuary, and 
 other similar ornaments, form a nidus for dust, which is objectionable. On 
 the other hand, they cannot be altogether excluded from a ward, as they give 
 an air of cheerfulness and home comfort which must be conducive to the 
 well-being of the patients. Pictures, therefore, should have the simplest 
 possible frames, and should be glazed, so that they can be easily dusted and 
 kept clean. They should be hung with picture wire, not cord, which attracts 
 the dust. The same rules should be observed as regards texts or any other 
 ornaments used about the walls. 
 
 The method adopted in the Johns Hopkins Hospital at Baltimore, U.S.A., 
 of joining the walls with the floor by a concave moulding, so as not to allow 
 
 durable than the soap-washed one of the present. Continual soap-washing, where there 
 is much treading, tends to a separation of the bundles of woody fibre from each other in 
 a deal floor. This may be seen in any of the soap-washed deal floors in our older 
 hospitals, and accounts for the ragged appearance which they often present. 
 
782 HYGIENE 
 
 any angle to exist for the accumulation of dust (which is with difficulty re- 
 moved by a broom from the usual corner between the skirting board and the 
 floor), is one worthy of imitation, but has been only rarely adopted in this 
 country. The same principle may be applied to the angle between the wall 
 and the ceiling. 
 
 In temporary hospitals and those in which cheapness is a great object, 
 the walls are fi-equently white-limed. This produces a rough wall, liable to 
 become dirty in all the parts within reach, and therefore requiring frequent 
 renewal. The coating of hme, also, soon loses the antiseptic quality which 
 makes it so excellent a material for use for short periods. It is therefore not 
 well adapted for the walls of permanent hospitals. On the other hand, for 
 ceilings its superior whiteness makes it a more desirable material than paint. 
 Such surfaces can be readily renewed once a year, and though the roughness 
 is an imdesirable quahty, yet the bright appearance which a frerihly white- 
 limed ceiling gives to a ward adds to its cheerfulness and consequently to 
 its healthiness. 
 
 The Beds 
 
 All bed linen should be frequently changed. Though no rules can be 
 laid down how frequently this may be necessary, yet it may be roughly stated 
 that it should be done once a week in every case, and very much more 
 frequently in those in which the secretions or discharges are abundant or 
 offensive. The woollen blankets and coverlets should also be frequently 
 washed and aired, or even baked at a dry heat of 300° Fahr., if the case is 
 a doubtful one. All dirty linen should be stored in covered baskets outside 
 the wards, or in closed tin-lined boxes inside the ward, if there are no con- 
 veniences for storage outside the ward. The former plan is best, because it 
 permits free access of air to the dirty linen. The boxes or baskets should be 
 emptied every day, and the contents taken to the laundry, where they should 
 first be disinfected by being placed in a large tank of antiseptic fluid. If 
 they be very dirty, or much soiled with blood or discharges, a previous soak- 
 ing in pure water is best. The use of solution of carbolic acid or any other 
 antiseptic for the first soaking tends often to set the discharge in the fibre of 
 the material, and thus to render more difficult the subsequent cleaning. This 
 is often the cause of the complaints made ahke by Sisters, nurses, and patients 
 against hospital linen, viz., that it does not return so clean and white from the 
 wash as the home linen does. The clean linen for the beds is brought into 
 the wards once or twice a week, and may be safely stored in cupboards or 
 boxes within the wards. 
 
 Draw-sheets and macintoshes used to protect the bed should especially be 
 frequently changed, and it is questionable whether it is advisable to mix 
 draw-sheets from offensive cases with the other bed linen from the ward. 
 The macintoshes should be those macintoshed on both sides, so as to 
 present a smooth, shiny surface on either aspect. These can be easily 
 washed and purified, and are besides much more durable and economical. 
 Those macintoshed between two layers of cotton stuff, and thus presenting 
 the rough cotton fibre texture externally, are very objectionable. They easily 
 become stained and dirty, and are difficult, if not impossible, to purify. 
 
 Splints used in surgical cases must be carefully washed and purified after 
 use. Those of wood should be washed with a solution of corrosive sublimate 
 and occasionally rubbed over with fine sand-paper. With these precautions, 
 the splints do not now become infested with vermin as they used to, even 
 as recently as twenty years ago. Consequently, there is no necessity for 
 
HOSPITAL HYGIENE 783 
 
 using any medicated wool for the pads of these splints, and plain cotton 
 wool or tow is the material generally used. Oakum or tenax, which was 
 formerly much used, stains the splints, and often the bed linen, by reason of 
 the tarry material contained in it soaking through. These materials are not 
 therefore now much in favour, and the necessity for them has mostly dis- 
 appeared since the careful purification of the splints. Nevertheless, any pad 
 may become accidentally infected from the patient's clothing, especially in 
 a case of accident, and hence these pads should be changed as frequently as 
 opportunity permits, and always burnt directly after use. 
 
 The bedsteads should of course be of iron, painted or enamelled, so that 
 they can be easily kept clean. Wire-woven mattresses are now much more 
 frequently used than formerly, though the ancient sacking, if kept sufficiently 
 tight, is not a material to be despised. It gives a certain springiness (as in 
 hammock beds), and is a material easily changed and purified. For fracture 
 beds, boards placed below the mattress are necessary, but they should be 
 washed with a solution of corrosive sublimate occasionally to prevent the old 
 trouble (inherent in all wooden structures) of their becoming infested with 
 vermin. The mattresses and beds are usually stuffed with flock, and this is 
 probably the best material that can be used in all large hospitals where 
 expense has to be considered. It has the advantage of being a cheap material, 
 and the beds are very easily purified and restuffed. 
 
 Flock beds can be changed if necessary with every new patient, and the old 
 bed sent to be cleansed and disinfected by superheated steam at a tempera- 
 ture of 300° or 350° Fahr. The flock is generally hand-picked through 
 before this, and any very bad pieces not easily cleansed are removed and 
 destroyed. Hence the advantage of a cheap bedding material. Hair mat- 
 tresses, as a rule, though better for many cases, are too expensive both in 
 material and working (when they have to be disinfected) for general use. 
 A hair mattress, if it has to be disinfected, has to be pulled entirely to pieces 
 to accomplish the process satisfactorily. Attempts have been made at various 
 places to disinfect a hair mattress en masse by subjecting it for a long period 
 to both dry and moist heat at a temperature of 350° F. It has been found 
 that such a long exposure is necessary in order to penetrate adequately the 
 structure of the mattress, and that the texture becomes greatly damaged in the 
 process. Hence this mode of disinfection has been abandoned. The pick- 
 ing to pieces of a hair mattress and re-stuffing it is a much more expensive 
 process than with the flock bed (to say nothing of the difference in the 
 original cost of the material), and hence we have a very powerful argument 
 in favour of the flock. If, however, for any reason hair mattresses are used, 
 the plan adopted at the General Lying-in Hospital, referred to later on 
 {vide p. 802) — of having a register of mattresses, each one ticketed and 
 numbered, and only sent away for purification when any doubtful case has 
 occurred with it — is a good one. 
 
 Dresses of Attendants 
 
 The Sisters and nurses should be dressed in some washable material. 
 In general hospitals clerks and dressers will usually wear their ordinary 
 woollen clothing ; and the medical attendants in England almost invariably 
 do the same. In many of the Continental hospitals, however, the medical 
 staff change their outer clothes on the visit to the wards to a suit of some 
 washable material. In operating, again, there is very great variety of practice 
 amongst surgeons even in England. Some assume a special operating dress 
 of washable material ; others a special macintoshed, shiny garment, which can 
 
784 HYGIENE 
 
 be easily washed down and pm-ified. The great majority of English surgeons 
 continue to wear an ordinary woollen operating coat, with perhaps a mac- 
 intosh apron and sleeves. At the present time there is a tendency in favour of 
 the Continental plan, viz., to adopt some washable material for operating in. 
 The writer is of opinion that the use of this will depend in the future very 
 much upon whether the carbolic spray is retamed or discarded in practice. 
 If it is retained, he thinks that the woollen coat becomes absolutely innocuous 
 by constant use in it. The sleeves and every other part become so impreg- 
 nated with carbohc acid in vapour and solution, that practically the blood 
 which gets on to the garment dries without decomposing. This may be 
 shown by mixing blood and carbolic lotion (1 in 30), or even pus and carbolic 
 lotion, together, and spreading them out in a fairly thin layer to dry. The 
 mixture di'ies into a leathery material, composed of coagulated albumen, 
 fibrin, blood-corpuscles, &c., which refuses to decompose in the ordinary sense 
 of the term. No doubt it undergoes chemical change, but not of a kind 
 prejudicial to subsequent operations. Even offensive cases, e.g., cases of de- 
 composing pus in abscesses such as occur in urmary or faecal abscesses, may 
 be operated on safely with an abundant carbolic spray (used as an irrigant) 
 in such a garment. But the treatment of such patients comes under the 
 head of infectious cases, rather than under that of ordinary aseptic surgery. 
 Still, every surgeon must necessarily treat such cases in the course of ordi- 
 nary practice, and often in wards mixed with other patients. If obliged 
 to do so, he will naturally put off such cases to the last, and he will be care- 
 ful not to use the coat again imtil it has been thoroughly aired and dried, 
 i.e., for at least twenty-four hours. With these precautions, the writer has 
 never seen any mischief result from the use of the ordinary woollen coat. 
 In our variable climate the use of this garment is so much more comfortable, 
 so much warmer and safer for the operator, as compared with the thin, 
 washable, generally linen or cotton garment usually substituted for it, that 
 its use will probably be generally maintaine d. 
 
 On the other hand, if the carbolic spray is given up, the vsriter is of 
 opinion that there is increased need for the washable garment, whether it 
 be of linen or macintosh, both for operator and for dressers. In these cases 
 asepsis is generally maintained either by continuous irrigation during the 
 operation from a large syringe or cistern, or by washing the wound out after 
 the operation is over. For reasons given subsequently {vide note, p. 788) 
 the writer regards neither of these alternatives as perfect. And, as far as 
 the dress of the operator and his assistants is concerned, they are absolutely 
 ineffectual. The air is no longer full of a fine antiseptic rain ; there is no 
 wetting of the clothes ; and though this may slightly contribute to the comfort 
 of those about, yet the risk must be very perceptibly increased. For these 
 reasons the tendency — very visible during the last year or two amongst those 
 surgeons who have abandoned the use of the carbolic spray — to adopt a 
 special washable dress for operating in must be regarded as a good one. 
 But if the rule is to be effectual, it must be extended to the assistants as well 
 as to the operator himself. 
 
 In very septic operations, and aU those performed on infectious cases in 
 isolation wards, a special external suit of clothing should be worn, which 
 should be kept solely for this purpose. In isolation hospitals, or wards of 
 large size, where many infectious cases are associated together, this rule 
 should be extended to the visit also. This applies, of course, to dressers and 
 house surgeons as well as to the visit of the medical or surgical staff. 
 
HOSPITAL HYGIENE 785 
 
 Visits op Friends to Patients 
 
 There can be no doubt that, though in all large general hospitals it is 
 absolutely necessary to allow these visits, they yet introduce a very consider- 
 able element of risk into the sanitation of the ward and into the treatment 
 of the patients. On several occasions the writer has seen infectious diseases 
 brought into hospitals by visitors coming from infected homes. There seems 
 absolutely no practical or workable plan of preventing this. It is no use 
 questioning the visitors before admission. Their eager desire to see their 
 relatives or friends in the hospital, or their crass ignorance as regards what 
 constitutes an infectious malady, makes them either regardless of the truth 
 or misleading in the expression of facts. Moreover, it is not possible to ex- 
 clude the relatives from hospitals or wards where surgical operations have tO' 
 be performed, because were this done a cry would speedily arise, especially 
 in cases which terminated unsuccessfully, that the patient had not been 
 treated well, that barbarities had been practised, &c., &c. — unfounded rumours- 
 such as have been propagated many years ago, either by ignorant or malicious- 
 persons, in respect to many hospitals. Such rumours and unfounded accusa- 
 tions can only be prevented by allowing the relatives and friends moderately 
 free access to the patients during their treatment. The great confidence 
 with which the public, both educated and ignorant, now treat our general 
 hospitals — a confidence which even the violent and widely spread slanders of 
 anti-vivisectionists and other fanatics have failed to shake — is largely due to 
 the friends and relatives being allowed to see patients, and thus to form some 
 idea for themselves how they are progressing, and how they are treated. 
 Still this introduces an element of risk from the cause mentioned, and it is 
 a subject of anxious consideration how far these risks may be minimised 
 without altogether preventing the visits. In all general hospitals of late 
 years a tendency to diminish the number and length of the visiting has been 
 apparent. Thus at Guy's Hospital there used to be three visiting days a 
 week ; now there are only two. At the Evelina Hospital for Sick Children 
 there used to be two, but now there is only one day a week. And in both 
 hospitals the number of visitors to each patient has been strictly hmited of 
 late years. Thus at Guy's, not more than three visitors are admitted at 
 once to see the patient ; at the Evelina only one at a time. It will be seen- 
 that the rule is much stricter in the children's hospitals than in the adult. 
 This has arisen from necessity, on account of the much greater risk of im- 
 porting infectious diseases amongst many children congregated together than 
 amongst adults. The writer has seen on so many occasions measles and 
 scarlatina break out in children's wards after the visit of some friend or relative 
 from an infected home, and the results are so disastrous, especially in surgical 
 wards where nearly all surgical operations have to be suspended during the 
 epidemic, and the ward practically closed — at any rate to all fresh patients — 
 that it would appear as if no rule were too strict to prevent the occurrence of 
 these outbreaks. It is for this reason that the number of visiting days each 
 week is restricted to one, and that only one friend at a time is admitted to 
 see the patient. Even with this amount of visiting, epidemics still some- 
 times occur. And it must be manifest that they could never be entirely 
 prevented, even were the friends excluded altogether, because there is always 
 the risk of a fresh child being admitted to the ward from an mfected home, 
 the previous surroundings of each freshly admitted patient being of course 
 quite unknown. 
 
 In isolation hospitals it is the rule not to admit any friend to see the 
 patient during his residence in the hospital, and it must be manifest that no 
 
 VOL. I. 3 E 
 
786 HYGIENE 
 
 relaxation of this rule could in any way be permitted without the risk of 
 spreading contagion, at any rate in the majority of infectious diseases 
 .admitted into these hospitals. 
 
 Patients' Clothing 
 
 The clothes in which a patient is admitted into hospital must be treated 
 according to the state in which they are found. If very dirty, they should 
 be sent back home by the patient's friends. This would be the best plan in 
 .all cases, and is indeed adopted at certain small special hospitals ; but in 
 large general hospitals it has been found that the sending for the clothes 
 involves so much delay when it is desired to discharge the patient, especially 
 when the friends do not particularly wish to have him home, that some plan 
 of keeping the clothes becomes absolutely necessary for the good working of 
 the hospital. This is best done by keeping each patient's clothes in separate 
 bundles in large closets outside the ward. Each bundle should be separated 
 from the others by a wooden or metallic partition, which can be easily taken 
 out, and the whole place frequently washed out. If wooden shelves and 
 partitions are used, they should be wetted with a solution of mercuric 
 chloride before being replaced, so as to prevent vermin. If the patient's stay 
 in hospital is likely to be a long one, soiled linen, &c., had better be washed 
 before being put away, and if there be a suspicion of vermin, the clothes 
 should be subjected to the dry-heat process before being placed in the closet. 
 Indeed, in some hospitals this is done with nearly all the clothes which are 
 kept. And it must be admitted that this question of patients' clothes is 
 often one giving much trouble, and requiring a good deal of discretion on 
 the part of the Sisters and nurses. The closets and trays especially require 
 continual overhauling, to see that everything is kept as clean and un- 
 objectionable as possible. 
 
 The clothes of a patient suffering from an infectious disorder must, of 
 course, be thoroughly disinfected and cleansed by one of the methods 
 mentioned elsewhere before being put away. Such clothing should be kept 
 by itself, and not allowed to mix with that from ordinary patients. 
 
 The writer does not here refer to the clothing to be worn by the patient 
 during his stay in the hospital. This will of course vary according to the 
 nature of the case. In a few hospitals it is pro\dded by the institution 
 itself, but in large hospitals more generally (and in the writer's opinion more 
 suitably) by the patient himself. Still, if the patient be very poor, it may 
 be necessary to provide more or less clothing in this way. And in most 
 children's hospitals in Tjondon a certain amount of the patients' clothing 
 while in bed is almost invariably provided by the institution — perhaps more 
 to give a pleasing unifui-uiity to the ward than with any actual charitable 
 intent. 
 
 LOCKEES 
 
 In nearly every hospital there is provided for each bed a locker, which 
 serves partly as a table, partly as a small cupboard in which patients can 
 place things. Though in most hospitals it is regarded as an almost neces- 
 sary adjunct to the bed, conducing to the comfort of the patient and to the 
 tidiness of the ward, yet it is one of the most doubtful articles — hygienically 
 considered — which a ward can contain. It is sometimes used for food, some- 
 times for articles of dress, books, &c., sometimes as a receptacle in which the 
 small pot used for urine or expectoration is hidden away. Nothing can be 
 nastier than this combined use of the same receptacle, even though it may 
 take place at different times. Those who kno^v the pecuhar saturating effect 
 
HOSPITAL HYGIENE 19,1 
 
 which a pot of warm urine has upon a commode, however carefully painted 
 (or polished if of a hard wood) its interior may be, will understand what the 
 Writer means. Good housewives even object in a well-ordered bedroom 
 to the pot de chambre being placed after use under the bed, especially if 
 the bed has a steel spring mattress, on account of the gradual rusting effect 
 of the vapour arising from the warm urine on the metal. If, therefore, one 
 patient uses his locker for urine, it will be impure always afterwards, 
 unless repainted in its interior. The greatest vigilance of the nurses is 
 unequal to meet this abuse. The writer has seen surreptitious food stuffed 
 into these lockers during visiting hour removed by the nurse examining the 
 locker after the visit was over, and yet an hour or two later more food has 
 heen found in the locker. Many of the patients act in ignorance of the 
 rules existing in most hospitals on this subject. Many more act in wilful 
 defiance of these rules, and nearly all are quite ignorant that these rules 
 .are made for their own protection and good. It is not easy to see how the 
 evil can be remedied, except by the complete abolition of the closed locker 
 and the substitution for it of a small table with open shelves below, where- 
 •on the nurses or Sister can see at a glance everything they contain. In 
 the furnishing of all new hospitals it is to be hoped that the locker of the 
 future will take this form. It will involve some sacrifice of tidiness, but 
 this will have far more than compensating advantages. Even upon the 
 shelves of these tables the urine pot should not be placed. Every urine 
 receptacle should have a small painted wooden or metal cover closely 
 fitting to the top, and it should be a rule of the ward that this cover should 
 be applied directly after use. The pot may then be placed safely below the 
 bed or upon a special shelf on the wall near the bed. But with the cover 
 there is really no objection to its being placed under the bed. During the 
 time of cooling of the urine any steam arising condenses on the cover, and 
 all harmful effects on the bed are prevented. The cover also excludes dust, 
 &c., from the urine, and thus renders its chemical examination afterwards 
 (should that be necessary) so much the more satisfactory. As far as expec- 
 toration is concerned, nothing can be better than the small earthenware pots 
 with funnel covers in use in the wards of most London hospitals. In the 
 case of fffical excreta, it need scarcely be added that of course they should be 
 removed as soon as passed, and that it is always desirable to keep a small 
 quantity of some rapidly deodorising solution in bedpans, slippers, &c., so 
 as to mitigate the nuisance of smell in a ward where the patient is obliged 
 to relieve himself in bed. 
 
 The keeping of food in lockers cannot be too strongly deprecated. In 
 some hospitals it is the custom to give out the day's allowance of bread, 
 butter, milk, &c., to the patient in the morning, and this is kept in the locker 
 till consumed or taken away. For the reasons given above, this should 
 never be allowed. All food should be kept under one common control, 
 should be served out fresh to each patient at the meal time, and the 
 remnants taken away afterwards. Nothing can be worse for the sweetness 
 and freshness of the food than the constant standmg of small quantities of 
 unconsumed food (such as bread, milk, &c.), whether in or outside a locker, 
 hy the patient's bedside all day. Nothing can more surely tend to the taking 
 away of what appetite he may have than the constant sight of such food. In 
 many hospitals, again, it is the rule for patients to provide their own grocery. 
 Even this is to be deprecated. But where the poverty of the hospital resources 
 renders this absolutely necessary, it is best that the grocery should be placed 
 in a small drawer in the table — a drawer too small and too shallow to contain 
 urine or any objectionable article. 
 
 3e2 
 
788 HYGIENE 
 
 Dkessings 
 
 Dressings are best kept in a ward in a cupboard or box by tbemselves.. 
 A movable table (running on wbeels witb indiarubber tires), fitted -vsath 
 drawers and small cupboards, is tbe best receptacle for tbe day's dressings. 
 Antiseptic dressings, wbere tbe dressing contains a vaporisable cbemical (as 
 carbolic acid, oil of eucalyptus, or iodoform), sbould be kept in an air-tight tin 
 or tin-lined box in tbe table. This is not of so much importance wbere tbe 
 antiseptic is fixed, as in sal-alembroth gauze and wool (corrosive sublimate). 
 But even here tbe material sbould be all kept together, packed away tightly, 
 so as to exclude dust as much as possible. 
 
 In many wards devoted to purely surgical patients it is most convenient 
 for the nurses to cut the daily dressings necessary for each patient some time 
 before the actual dressings are done. For this purpose it is best to have 
 several pieces of American cloth, made with flaps at the edges (as in music 
 portfolios), and lined with some waterproof material (not macintosh), such 
 as ' waterproof muslinette.' In these the dressings for each case can be 
 tightly rolled, and tied with coloured tape. The dressing necessary for each 
 case can then be laid by each bed, and await without harm the visit of the 
 surgeon or dresser. In this respect nothing can be worse than dressings cut 
 some hours beforehand and lying about unfolded, or only loosely folded, ex- 
 posed to the air and to the access of dust. If the antiseptic is vaporisable, such 
 treatment of the gauze simply spoils it, and is the cause of many failures 
 in the aseptic treatment of wounds. If it is fixed, though it may not be so 
 prejudicial, yet the free access of dust will imperil the success of the case. 
 
 Where the spray is employed, the top of the dressing table may be used 
 for it, and for a dish of antiseptic lotion for instruments or for washing 
 wounds. Many surgeons do not now use the spray, but trust to asepticising 
 the wound after the operation is over by irrigating it with corrosive sublimate 
 solution or some other antiseptic. The writer has not himself abandoned 
 the spray, though he recognises that there are disadvantages attached to its 
 use. These, however, may be minimised if their existence is recognised, 
 and they appear to him to be altogether less than the very serious evils which 
 may arise from its non-use.^ 
 
 ' As regards the use of the carbohc spray for operations, it may be thought after the 
 very explicit declaration against its utility by its inventor, Sir Joseph Lister, at the- 
 Berlin International Medical Congress of 1890, that it would naturally fall into disuse. 
 This is no doubt largely the case, but it is not in accordance with the writer's own views 
 about it. 
 
 There are two ways in which the spray may be used : (1) as a vapour ; (2) as an 
 irrigant. Sir J. Lister has always used it in the first, the wi-iter in the second way. 
 To obtain the first, the spray is placed at a considerable distance from the patient — a 
 distance sufficiently great to allow the minute globules of carbolic lotion to evaporate into 
 the air before reaching the patient, thus producing an atmosphere charged with carbolic 
 acid, in which it was beUeved no germ can live. To obtain the second, the spray is 
 placed only a short distance from the patient (2-3 feet), so that the finely divided globules 
 of carbolic lotion shall fall directly upon and wet the wound. The use of the spray in the 
 first way is undoubtedly a delusion. It sounds scientific to disinfect the whole of the 
 air about the patient and the operator, but the writer has convinced himself that it is not 
 practicable. Germs may remain untouched in this antiseptic atmosphere, and may fall 
 on the wound, and produce the usual septic trouble afterwards. In the second way, 
 although germs may still fall upon the wound untouched in the midst of the spray, yet 
 they fall upon a surface wet with the antiseptic, and they are therefore quickly destroyed. 
 No doubt the irritating action of carbolic lotion is rather greater, when used as an 
 irrigant, than when used in the first way ; but this disadvantage is more than overbalanced 
 by the greater security obtained. It may be said. Why then not make use of carbolic 
 lotion to irrigate the wound at the end of the operation, instead of using such a cumbrous 
 
HOSPITAL HYGIENE 789 
 
 "While upon this part of the subject, it is necessary to utter a warning 
 about the neglect of antiseptic precautions, which may very likely arise in 
 the future, even if it is not already beginning in sonie hospitals. In the 
 way surgery is now practised, medical students of the present generation have 
 had very few opportunities of seeing the results of septic wards in our large 
 general hospitals. The cases do so well, with such httle disturbance from 
 .septic causes, that there is great risk that the surgeons of the future may get 
 to disbelieve in the very serious risks which the want of observance of anti- 
 septic precautions will entail upon them. The risk is the greater because 
 there will be no sudden change from surgical results, as they now are, to the 
 Tesults of thirty years ago. In looking back over this period it can plainly be 
 perceived that the introduction of antiseptic surgery did not work any .s?.tcZtZew 
 transformation in hospital wards. For a longtime ih.Q principles of anti- 
 septic surgery were in doubt, and were only practised by one or two surgecns 
 here and there. An aseptic case or two lay amongst many others mixed all 
 together in the wards. Nevertheless, even those few had a certain influence 
 
 method as the spray ? There was great weight in the argument made use of, the writer 
 believes, by Sir J. Lister, on his first introduction of the spray, though since then seldom 
 heard, viz., that during an operation, when making successive incisions, especially amongst 
 the muscles, the parts retract unequally, and thus dust-germs are apt to get tucked away 
 into secure recesses of the wound, which are never reached by irrigation performed after 
 the operation is over. This risk is avoided if continuous irrigation by the spray is going 
 •on during the whole performance of the operation. 
 
 Irrigation in some form is nearly always practised by those who have given up the 
 use of the spray. But here again there is great difference of opinion as regards the anti- 
 septic to be used, and as to the strength of the solution. Corrosive sublimate solution is 
 that most in use at the present time, but it is sometimes employed at a strength of 1 to 
 1,000, sometimes at 1 to 10,000, and at all degrees of strength between these two. This 
 very great divergence in the practice of surgeons is likely to engender carelessness and 
 ■disbelief in the minds of those who are now studying surgery for the first time. From 
 what he has seen, the writer does not believe in the efficacy of solutions of 1 o 10,000. 
 While admitting that there may be some range of variation in different cases in the 
 strength of the solution we employ, the wi'iter thinks that the minimum strength should 
 be 1 to 2,000, and that a strength of 1 to 1,000 will prove the right one in the great majority 
 ■of cases under treatment. For the reasons already cited, the bad results of employing 
 too weak solutions will not very obviously appear at once. 
 
 As an instance of what harm may result from the employment of too weak solutions, 
 the writer may state what took place some years ago within his own knowledge at a chil- 
 dren's hospital in the comparative infancy of asepsis. For some months there was 
 failure in the aseptic results of operations. Inquiry was made at different times in very 
 TTarious directions to try and account for their failure. The goodness of the gauze was 
 suspected ; the hygienic surroundings of the patient, the conditions of the operator, 
 nurses, and house surgeon were inquired into. Again and again the strength of the 
 antiseptic solution was challenged, but the dispenser always sent in the assurance that it 
 was right. This went on for so long that at last the writer was almost inclined to admit 
 that children's tubercular joint operations (in which principally the failures took place) 
 were more difficult to keep aseptic than the same cases in the adult. Finally, it was dis- 
 covered by the energy of a new house surgeon (Dr. Henry Davy, now of Exeter), and this 
 only by absolutely standing over the dispenser, and watching him make it, that by some 
 curious perversion of arithmetical calculation he was sending up the carbolic lotion to 
 the wards, instead of a strength of 1 in 20, something more like 1 in 100, so that the 
 antiseptic made use of was almost indefinitely weak. The writer believes this was done 
 entirely ionA fide, and was due to a failure of arithmetical calculation, which once wrongly 
 carried out repeated itself each time in the dispenser's mind. Another similar failure 
 in the preparation of an antiseptic solution of right strength the writer detected in 
 another place by having himself made many times the preparation, and noticing the 
 difference in that supplied. This again was due to a wrong arithmetical calculation — 
 ■only in this case it was not attended with such serious results. 
 
 It is not within the range of this article to discuss the strength of other antiseptics 
 ,nor the varieties of wound or operation in which each different antiseptic is of most use. 
 
790 HYGIENE 
 
 on the well-being of the rest, and, as they increased in number, the chances 
 of the rest of the cases, not treated on antiseptic principles, perceptibly im- 
 proved. This was because there was a smaller proportion of foul air-infecting 
 cases in the ward ; the surroundings for all the patients became more 
 hygienic, and consequently they did better. If we imagine a ward of thirty 
 patients, twenty-nine of whom were aseptic cases and one treated (say an 
 amputation) without recourse to antiseptics, it is clear that this one patient 
 would have a much better chance of escaping septicjiemia than if he were one 
 in a ward full of septic cases. Similarly, at the present time, a single case, or 
 more, may be operated on in our wards without recourse to antiseptics, and yet 
 may do well, because he is surrounded with healthy cases. Thus may arise 
 the risk of the future. A young surgeon, never having seen the deplorable 
 results of surgery as older surgeons saw them thirty years ago, may operate 
 without the use of antiseptics, and may possibly be able to point to case after 
 case being operated on successfully, until he begins himself to enunciate as a 
 law his conclusions that antiseptics are unnecessary, and that surgeons have 
 been labouring under a great delusion in the past as regards their use. 
 There is very little doubt that his results in the process of time will undeceive 
 him, or at any rate those watching these results. But this "will entail a 
 considerable loss of hfe, and an amount of suffering to individual patients, 
 which will only be prevented by careful attention on the part of medical 
 students and teachers to the history of the surgery of the past thirty or forty 
 years. 
 
 Instrumentation 
 
 Under this heading is included the keeping of instruments used in 
 dressings and operations clean and ready for use. The instruments got ready 
 for any particular operation should be placed in a shallow tray containing anti- 
 septic solution shortly before the operation takes place. After the operation 
 they should be at once cleansed from blood or discharges by washing in cold 
 water. They may then be sterilised by placing in boiling water for a short 
 time. For steel instruments with a cutting edge this period should at the 
 outside scarcely amount to two minutes, or the edge and the polished surface 
 will be dulled. Each instrument should then be quickly dried and polished 
 before being put away. If the instrument be composed of metal and some 
 other material, such as an ivory or wooden handle, only the metal part (as 
 far as possible) should be immersed in the boiling water. Repeated immer- 
 sions of wood or ivory in boiling water spoil them and loosen the attach- 
 ments. Moreover, it is unnecessary ; the immersion of the handle in the 
 antiseptic fluid immediately before the operation sufficiently asepticises it, 
 and prevents the carrying of germs from one patient to the other. Most 
 probably this immersion will also asepticise the metallic part, but this is more 
 doubtful. Most steel instruments have minute crevices and crannies (e.g., 
 the serrations of artery forceps or minute depressions where spots of rust 
 have accidentally eaten into the metal, &c.) ; these become filled with 
 coagula of blood during the operation, and these are exceedingly difficult to 
 detach by the cleaning process. Moreover, each of these little masses of 
 coagulum is exceedingly difficult to sterilise by mere immersion in an anti- 
 septic solution. The outside layer of coagulated albumen resists the action 
 of the solution, and, as the mass adheres very strongly to the metal, germs 
 may remain unacted upon until accidentally set free by the next operation. 
 A small metal (brass wire) brush, used by artificers in one of the steps of 
 brass polishing, is exceedingly useful in cleaning out the teeth of forceps and 
 other minute depressions in metal instruments. But even when all these 
 
HOSPITAL HYGIENE 791 
 
 precautions have been used, the writer has frequently seen most carefully 
 cleaned instruments, when next put to soak in water or antiseptic solutions, 
 throwing out from some invisible crevice blood-pigment, which slightly stains 
 the water ; thus showing that, in spite of the care used, some red blood-cor- 
 puscles were left unaltered on the instrument, and that these have become 
 ruptured by endosmosis from the fresh soaking in water, and thus may very 
 possibly be centres of infection in any fresh operation. On the other hand, 
 if the metal part of the instrument be subjected for two or three minutes to 
 the heat of boiling water, from the conductivity of the metal for heat each 
 of these little masses becomes of such a temperature that it can scarcely 
 escape sterilisation.' 
 
 The only objection to the heating process is in the case of knives used 
 for very delicate operations, where the temper is a matter of considerable 
 importance. The degree of heat (212° F.) may have the effect of altering 
 the temper to a slight extent, and thus deteriorating the edge. With large 
 knives and scalpels, the alteration is not of such degree that it should be 
 allowed to be of sufficient importance to warrant its non-use from this cause. 
 With a few eye-instruments (cataract knives, &c.), their small size, and the 
 very perfect piece of metal of which they are composed, make it possible 
 to keep the whole of the surface at such an exceedingly high degree of polish 
 that the precaution may not be so necessary in their case. But in all other 
 cases the precaution is an essential one. In the majority of surgical instru- 
 ments it must be manifest that there cannot be the slightest objection to 
 their sterilisation by heat. Directors, probes, retractors, all kinds of bone 
 forceps, small saws, trephines, elevators, and a vast number of other instru- 
 ments can all be most easily sterilised by its use. It is especially essential 
 in those which are actually used upon the flesh of the patient. I need only 
 instance artery forceps, the serrated teeth of which need the greatest care. 
 Again, tracheotomy tubes are instruments to which the heat-sterilising pro- 
 cess can be most advantageously applied. And there is no class of instrument 
 in which the absence of this precaution is attended with more dire results. 
 In years gone by, when the disinfection of instruments was less thought 
 about than at the present time, and when less was known about the causa- 
 tion of disease, the writer has seen numerous cases of tracheotomy followed 
 by fatal results from diphtheritic infection of the wound, arising from the 
 metal tracheal tube not having been perfectly sterilised after having been 
 previously used in an infectious case. Thus a tracheotomy might be done for 
 a case of scalded glottis ; the child would do well for a day or two, then 
 develop a diphtheritic exudation about the wound, which would rapidly spread 
 to the scalded glottis and the trachea, and the child would die from this cause. 
 
 Though diphtheritic tracheotomy wounds cannot even now be wholly pre- 
 vented (a case arising every now and then, when the operation has been per- 
 formed for diphtheria of the larynx, either by auto-infection or by extension 
 of the diphtheritic inflammation from the throat downwards), yet it is probable 
 that the much greater success which attends tracheotomy now than when 
 the operation was first introduced is due for one reason to the much greater 
 
 > A word must be said here in favour of the surgeons of the future learning something 
 of artisan knowledge respecting the manipulation of their instruments, and the materials 
 of which they are composed. It will be found very useful. Many surgeons are no doubt 
 accomplished mechanicians, but amongst many others there is a tendency to look with 
 contempt during their earlier years in the profession (when alone they have time to acquire 
 the knowledge) upon any knowledge of this kind. This is a mistake. As far as the anti- 
 septic treatment of instruments is concerned, they may be kept much more perfectly 
 aseptic if the surgeon is willing to look after them himself, and has the requisite amount 
 of knowledge as regards the treatment of the material of which they are composed. 
 
792 HYGIENE 
 
 care which is taken in the disinfection of the tubes than formerly. In the 
 instruments used on the aUmentary or genito-minary mucous membrane 
 the dismfection of the instruments is of very great importance on account of 
 the frequent infective character of the discharges. As far as these instru- 
 ments consist of metal, no difficulty will be met with in purifying them ; but 
 in the case of gum-elastic instruments, whether they be throat bougies, rectal 
 tubes, or catheters, there is considerable difficulty in knowing what to do. 
 They cannot be sterilised by heat without injury. Although it is a common 
 practice to dip a gum-elastic catheter into hot water to soften it and render 
 it more flexible, yet mere hot water is not sufficient for sterihsation. Nothing 
 less than a boiling temperature continued for a minute or two will be suf- 
 ficient for the destruction of germs, and it will be found that to boil gam- 
 elastic instruments for this time is equivalent to their very rapid destruction. 
 Many antiseptics soften and destroy the gum resin which gives the 
 smoothness and polish to the outer surface of these instruments. The writer 
 is convinced that the common fashion of wrapping a gum-elastic catheter in 
 a piece of carbolic gauze is very prejudicial to the catheter, rendering it 
 sticky and causing the loss of its polish, besides being of doubtful utility as 
 an antiseptic. Probably the better course is to dip the catheter in a watery 
 solution of corrosive sublimate (1 in 1,000) for a minute or two before use. But 
 for all hollow gum-elastic instruments it is best to burn them directly there 
 is the least suspicion of their integrity. The inner bore of all such instru- 
 ments is exceedingly difficult to purify satisfactorily, after they have been used 
 for cases in which blood or pus gains access to the interior. And although 
 this sm'face does not come into absolute contact with the mucous membrane 
 of the patient, yet it may easily be a source of infection, if there be any 
 impure material adhering to it. Even with a silver catheter, it must be a 
 matter of every-day experience to surgeons how difficult it is to clear away 
 the last traces of blood-clot from its interior. Though it may have been 
 soaked in water, and blown through, and raked out with the stilette, though 
 even a current of water may have been run through it, the surgeon will not 
 infrequently find, after drying and polishing, that when again put into fresh 
 water before use a slight colouration issues from its interior. These catheters, 
 however, can be easily sterilised by heat, and it is a considerable argument for 
 their use in skilled hands. If, however, there are such difficulties in rendering 
 the inner bore of metallic catheters clean without the aid of heat, much 
 more will there be with gum-elastic instruments. The inner surface is rough 
 and h-regular, and has none of the beautiful polish of the exterior, as will be 
 seen by cutting such a catheter open. In private practice the writer always 
 tries to make use of new catheters for every fresh patient, or to keep the 
 same catheters for the same patient. Even this is difficult, and in hos- 
 pital practice it will be found next to impossible. Some plan, then, by 
 which the catheter can be purified, or, if not absolutely purified, rendered 
 innocuous to the patient next succeeding, is very important to obtain. Such 
 plan the writer has carried out lately by dipping the catheter into a thin 
 solution of spirit polish, rendered flexible and unlikely to crack by the addition 
 of a small quantity of castor oil (10 drops to a fluid ounce of the polish). 
 After such dipping, the catheter has to be drained and hung up to dry, all 
 touching being avoided until it is absolutely dry. This process renews the 
 polish on the exterior, and if there be any foreign material in the interior, 
 it varnishes it down, so that it no longer floats about freely when the catheter 
 is used — to say nothing of the antiseptic effect of the rectified spirit upon 
 it during the soaking and drying processes. Of course, this process sooner 
 or later chokes up the bore and eye of any catheter, the smaller ones espe- 
 
HOSPITAL HYGIENE 793 
 
 -cially, but it will be found that it prolongs the life of a catheter very much, 
 and it also offers a mode of proceeding by which one is not afraid to make 
 use of a catheter about which it is doubtful whether it has been used before 
 ■or not. It will be of especial service to country practitioners, whose 
 opportunities of getting new catheters are very limited, and who yet do 
 not wish to keep a large stock of such perishable articles. 
 
 Sponge Pkepabation and Cleansing 
 
 The question whether sponges are reliable articles, and should be used for 
 ■operations, has for many years been a moot point amongst those practising 
 antiseptic surgery. By many, sponges have been discarded altogether, as 
 involving too much risk of carrying material from one patient to another. 
 These surgeons use lint or wads of cotton-wool, which are thrown away after 
 the operation. Since the manufacture of the cheap cotton-wool artificial 
 sponges (each containing a glass globule with eucalyptol in its interior, which 
 is to be crushed at the time of use), the performance of even large operations 
 has become very possible by their use. And it may be laid down as a general 
 rule that these artificial sponges should be used in all foul cases, if possible. 
 But even these are very imperfect substitutes, and, in fact, true sponges are 
 .articles which will not be lightly given up by those who know their valuable 
 ■qualities if in any way they can be made reliable. Other surgeons will only 
 use new sponges ; this, however, is a very expensive proceeding, almost im- 
 possible for hospital practice, and it distinctly introduces a new risk — in the 
 imperfect freeing of the new sponge from all the sand and other foreign material 
 which commercial sponges contain. It is possible to do this effectually where 
 ■ only a small number of new sponges have to be prepared, but it would be 
 practically impossible where a very large number are used, as would be the 
 case if new sponges had to be prepared for every operation. As a matter of 
 fact, the writer believes from long experience that sponges may be so prepared 
 :and cleansed after each operation that they can be used with perfect safety 
 from one patient to another. The first cleansing of a commercial sponge 
 from sand, &c., consists in first shaking and beating the sand out dry, then 
 ; soaking and squeezing in many successive waters. This will probably take 
 days or weeks to perform. It is very desirable that it should be thoroughly 
 done, for, in addition to the sand, new sponges generally contain very minute 
 transparent spines, which run into the skin and are very painful and difficult 
 to remove, as all who have cleaned new sponges will know to their cost. 
 The irritant effect of these spines upon a wound may be well imagined by 
 those who have experienced their effect on the skin.^ When free from the 
 sand, a new sponge may be softened and bleached by first soaking in fairly 
 strong solution of permanganate of potassium until the sponge assumes a deep 
 brown tint, and then passing it quickly through a solution of sulphurous acid 
 '(the pharmacopoeial preparation mixed with an equal bulk of water). This 
 process not only whitens and softens, but detaches and dissolves hard particles 
 remaining, and after again washing freely in water the sponge is ready for use. 
 
 Another plan, recommended by Borham, and adopted by Greig Smith 
 (* Abdominal Surgery,' 4th edit., p. 64), consists in soaking the sponge, after 
 treatment with the potassium permanganate, in a solution of sodium hypo- 
 
 ' The freeing of imported sponges from sand, &c., is now generally done by machinery 
 on a very large scale. The purchase of the already cleaned sponges saves much time and 
 labour, but even in these some sand is left behind, and care should be taken to free them 
 from this remnant as carefully as possible. Bleached sponges can now also be purchased, 
 lof course at considerably enhanced cost. 
 
794 HYGIENE 
 
 sulphite (half a pound to a gallon of water). To this solution, after soaking^ 
 the sponge for a time, about four ounces of oxalic acid are added. A chemical 
 action follows, sodium oxalate, sulphurous acid, and free sulphur resulting. 
 The sponge becomes rapidly bleached, and any free fibrin contained in its 
 meshes is dissolved out. The sulphur set free requires a good deal of wash- 
 ing to get rid of it, and hence this process takes longer than that already 
 advised. On the other hand, a small quantity of free sulphur left imbedded 
 in the sponge probably slowly oxidises, and thus may tend to keep it sweet. 
 When a sponge has been saturated iritli blood during an operation it 
 should first be cleaned by soaking and squeezing in frequently renewed cold 
 water. (Very hot water coagulates the albumen of the blood and makes the 
 sponge much more difficult to clean. It also damages the texture of a sponge, 
 and boiling a sponge so shrinks and contracts it that it is scarcely fit for use 
 afterwards. Hence the method of heat is inapplicable in the disinfecting of a 
 sponge.) When free from blood and coagulum, as far as possible, it should be 
 put to soak in carbolic lotion (1 in 40) for twelve to twenty hours ; then again 
 washed freely in cold water before being put aside for use. Every sponge 
 before a fresh operation is put to soak in 1 in 40 carbolic lotion. This method 
 is the one almost universally in use at Guy's Hospital, and gives satisfactory 
 results. If a sponge has been used for a very foatid discharge, it should be 
 either thrown away or put to soak in some of the bleaching solution of sul- 
 phurous acid for a quarter of an hour before soaking in the carbolic hquid. 
 It is curious that sulphurous acid has very httle bleaching power upon a 
 sponge which has once been soaked in carbolic solution, though it readily 
 bleaches before this is done. The writer has thus gone into the question of 
 sponge treatment because he believes it to be one of very considerable im- 
 portance. For a long time he was doubtful whether any cleansing process 
 was sufficient for a sponge once saturated with blood, but long experience 
 and careful watching of the cases where sponges so treated have been used 
 have convinced him that, if fairly done, they can be relied on. The results 
 of abdominal surgery with such sponges have perhaps done more to convince 
 him of the efficiency of the process than anything. He has used many other 
 methods also. A dilute solution of a caustic alkali has perhaps been the 
 favourite ; it tends to dissolve the fibrinous coagulum, but it also damages 
 the texture of the sponge if frequently used ; and he has come to the con- 
 clusion that it is not necessary. 
 
 Cooking Arrangements 
 
 The ward kitchen should always be separated from the ward, and' 
 separate ventilation should be provided for it. The old custom of cooking 
 in the ward by nurses or helpers can only be described by the word ' nasty.' 
 It is probably not so injurious as many other things about a ward, but the 
 mingling of the fumes of the cooking with the air of the ward destroys its 
 freshness and cannot conduce to the patients' appetites. Moreover, it takes 
 off the attention of the nurses from their proper duty, viz., nursing. 
 
 Isolation Wards 
 
 These are absolute necessities, both for medical and surgical cases, 
 in all hospitals : in the latter more especially, for erysipelas and very foul 
 cases ; in the former, when there is an epidemic outbreak of zymotic disease,, 
 such as scarlatina, measles, small-pox, typhus, &c. 
 
HOSPITAL HYGIENE 795 
 
 The avoidance of the undue herding together of the fever cases causes 
 the dilution of the poison and contributes in a marked degree to their re- 
 covery. It is always difficult to prove this from statistics, the number of 
 cases dealt with even in the large wards at Guy's Hospital being but small. 
 But it is supported by much that is observed in private practice in infectious 
 cases, and also by what has been observed in some of the fever hospitals. In 
 the latter, the late Dr. Mahomed (who as physician to the Fever Hospital at 
 Islington had a large amount of experience in such cases) is the writer's 
 authority for saying that after every time of purifying, white-liming, and 
 re-painting the wards, the patients with scarlatina first received into them 
 did better than those received into wards not so purified ; that the walls, &c. 
 after a time became so saturated with the poisonous emanations that even 
 fresh scarlatinal cases, presenting a mild type when first received, were 
 very liable to severe throat troubles, glandular abscesses, and sloughings, 
 &c., when they were received into wards at all stale. And this is in accord- 
 ance with the writer's own experience in private practice. He has on two 
 or three occasions seen an epidemic of scarlatina run through a large family 
 or school of children. These children have been placed in two or three rooms 
 in the top of the house, case after case as they occurred. The first case has 
 been of a mild type and has done well. The succeeding cases have presented 
 symptoms of increasing intensity, and in the last case or two he has been 
 called in to do various surgical operations on their throats for sloughing 
 glands, and phagedenic ulcerations of the worst possible type. He has always 
 attributed this to the intensification of the poison in the rooms set apart 
 for the patients.^ 
 
 In the case gf scarlatina, measles, and small-pox it may be conceded that 
 isolation rooms or wards are absolutely necessary for the safety of the rest 
 of the patients, but great care should be taken in the frequent purification 
 and disinfection of such wards. In the case of typhus probably the same 
 is true, though, with due care as regards number, cases of typhus in former 
 epidemics have been placed and treated successfully, without spread of the 
 malady, in the large wards at Guy's amongst the other patients. In the 
 case of typhoid and diphtheria a certain number of such cases are still 
 admitted into the general medical wards with favourable results. As regards 
 typhoid, the spread of the malady amongst surrounding patients is almost 
 unknown, if the before-named proportion of cases is duly maintained. It 
 is very many years since an epidemic of typhoid has occurred in a Guy's 
 ward — and when that took place it was due to accidental overcrowding of 
 typhoid cases into one ward. As regards diphtheria, the risk of the spread 
 of the disease is greater, but more amongst those nursing the case than 
 amongst the ordinary patients, though even the latter is not unknown. 
 
 Although an isolation ward should be attached to every general hospital, 
 it is not desirable that this ward should be made use of for the treatment of 
 
 ' The writer would note here the very great improvement in the treatment of such 
 cases by the extended use of aerial disinfectants. The old method of a sheet saturated 
 with carbolic solution and suspended in the chamber had a certain value, no doubt, but it 
 was altogether insufficient. In the method of vapourising carbolic or creosotic antiseptic 
 compounds by heat, there is a very great improvement. Many instruments for this pur- 
 pose are now sold. The little cresolene lamp may be cited as an instance. This is a very 
 small petroleum lamp with a porcelain cup fixed over it, in which the cresolene is 
 placed. The cresolene only evaporates very slowly, and condenses on everything in the 
 chamber, so that in a room in which it has been burning for some hours everything — 
 curtains, walls, bed, &e. — smells more or less of the material. Efficient antiseptics used 
 in this way cannot but have a considerable value in diminishing the virulence of the septic 
 poison. 
 
796 HYGIENE 
 
 an infectious fever during its entire course, but only for the separation of 
 the case from other patients while the diagnosis remains doubtful. When 
 the case has folly declared itself, it should be removed, if possible, to a 
 hospital for such cases entirely separated from general cases. In London this 
 is carried out by the removal of such cases to the hospitals of the Metropolitan 
 Asylums Board. 
 
 The disinfection of cm isolation ward is best accomplished by burning 
 sulphur in it, and keeping the room as tightly closed as possible for twenty- 
 four hours afterwards. The fireplace should be closed by temporarily 
 pasting paper over it, and the crevices of the windows and doors as far as 
 possible by sand-bags. The amount of sulphur burnt should vary with the 
 infectiousness of the case or cases which have been previously in it. A 
 good rule is to burn not less than one pound to every 2,000 cubic feet of 
 space. The sulphurous acid gas so produced impregnates everything in the 
 apartment, and acts in itself as a most potent germ-destroyer. In addition 
 it oxidises slowly in contact with the atmosphere, and thus becomes con- 
 verted into sulphuric acid, which remains very persistently about every- 
 thing, and this acts still further as a germicide. At the end of twenty-four 
 hours the Avard should be thoroughly aired, and walls and floor washed with 
 solution of carbolic acid (about 1 to 40). Fresh white-liming the ceiling 
 is a good adjunct, but it cannot be done after every case, and it is not 
 necessary. At the London Fever Hospital the small separate rooms used 
 for private patients and doubtful cases are disinfected after every patient, 
 but the larger wards can only be done periodically. The reason, however, 
 for disinfection of the small rooms after every patient is that, when patients 
 are first taken in, the diagnosis is sometimes doubtful, and it would not be right 
 to place a patient, perhaps not suffering fi-om any infectious disease at all, in 
 a ward which had been just occupied, say, by a scarlatina or measles case, 
 without in the first place thoroughly disinfecting it. The same rule should 
 be applied to all isolation wards in general hospitals. It has long been in 
 use in those at Guy's Hospital with the most beneficial results. 
 
 Kesults. 
 
 With the greatly increased care given to the hygienic condition of the 
 wards in our hospitals a most remarkable improvement has followed in the 
 mortahty statistics of operations. Erysipelas and pyaemia have almost 
 completely disappeared as endemic affections in our hospitals. Indeed, if 
 a case of blood poisoning is seen in a ward, it may be almost certainly 
 assumed that it has either been admitted as such from outside the hospital, 
 or that the case has been of such a nature as to lead to very widespread in- 
 fection of poisonous material, such as cannot be entirely disinfected and de- 
 stroyed. As instance of the former, the writer may mention the cases of 
 acute necrosis — examples of which are always to be found in surgical wards. 
 As instance of the latter, the cases in which London mud and dirt have been 
 very deeply ingrained into the cutaneous and deeper structures, in those 
 accidents in which patients have been dragged for a distance along the pave- 
 ment or over granite setts, thereby producing a very deep inoculation of the 
 foulest dirt in existence, viz., the various excreta which constitute the mud 
 and dust of the streets of our large towns. Such inoculations often occur 
 over areas of tissue so extensive, that it is practically impossible to remove 
 or completely destroy the infective material. The difficulty is rendered the 
 greater, because, in spite of the foulness of the material ingrained into the 
 tissues, many of these cases show such power of resistance to the poison 
 
HOSPITAL HYGIENE 797 
 
 that they ultimately do well. Nevertheless, in such cases the risk of septi- 
 caemia and tetanus is considerable. Thus in a case which was admitted into 
 the writer's ward at Guy's Hospital, while away for his summer holiday 
 some years ago, the patient had fallen into a dustbin, producing a compound 
 fracture of both his legs. The bones protruded and were caked with dust. 
 They were very carefully cleaned and disinfected before reduction, but it was 
 recognised at the time that perfect cleansing and disinfection were impos- 
 sible. On his return the writer found the boy suffering both from tetanus and 
 from marked signs of pytcmia. He amputated the worse leg, but naturally 
 failed to save the life of the patient. The post-mortem examination showed 
 abscesses in the lungs and commencing suppurations in the joints. In- 
 stances such as this might be multiplied, but it is evident that their existence 
 does not prove anything against the healthiness of surgical wards. It is only 
 when cases of blood poisoning arise de novo within the ward, in cases of 
 operation in which the wound was originally sweet, and ought to have been 
 kept so, that any fear should arise as regards the hygienic surroundings. 
 
 There can be no doubt that the main cause of the improved results in all 
 surgical wards of late years is almost entirely due to the adoption of the plan 
 of treating wounds advocated by Sir Joseph Lister. In Guy's Hospital, for 
 example, the condition of the surgical wards, as regards ventilation, heating, 
 and general sanitation, has not been very materially altered from what it was 
 twenty years ago. And yet by the simple adoption of this mode of treatment 
 of wounds, erysipelas, pyaemia, and blood poisoning, as just said, have been 
 almost abolished from the wards, and operations of the most serious kind 
 are now done safely, which formerly would almost certainly have terminated 
 fatally. This improved state of the wards reacts also in the improved 
 health of the resident medical staff. Twenty years ago it was exceedingly 
 rare for the house surgeon of the period to pass through his four-months 
 term of office without being laid up once or more, often by an attack of what 
 was called * surgical sore throat ' — a form of septic absorption due to foul 
 smeUs arising from surgical wounds and dressings. Now the occurrence of 
 surgical sore throat in the resident staff is very rare. Again, the writer will 
 have to show later on that in quite another department of medicine, viz., mid- 
 wifery, the great improvement in the mortality of the General Lying-in Hos- 
 pital took place — not after structural alterations, and improved hygienic apph- 
 ances about the hospital — but after the use of corrosive sublimate solution as a 
 germicide, for injections, for the nurses' hands, and for disinfecting all instru- 
 ments. The writer would not wish for one instant to undervalue the importance 
 of all hygienic arrangements in hospital and ward construction, &c., as well as 
 the hygienic ordering of a ward ; but it is important that the relative value of 
 these factors should not be lost sight of, and the fact remains that to the 
 recognition of the truth of these principles must be attributed the great 
 surgical triumphs of the age. 
 
 As an example of the condition of things in surgical wards prior to the 
 advent of Listerism (a condition which sounds almost incredible now, after 
 the lapse of only twenty years), the writer may mention an incident which 
 occurred to him when first appointed (in 1870) on the surgical staff of Guy's 
 Hospital. One of his early operations was an amputation through the thigh 
 for a compound smash of the leg. The Sister of the ward (who had been 
 forty years in the service of the hospital) shook her head after the operation 
 and prophesied the death of the patient, remarking that ' these cases never- 
 recovered.' In that case she proved right, though the statement itself was 
 no doubt an exaggeration. Still it shows the general impression which the 
 results of these thigh amputations had left in her mind. At the present 
 
798 HYGIENE 
 
 time no Sister of any experience in Guy's Hospital could repeat such a state- 
 ment. Indeed, thigh amputations in the lower thigh for disease (excluding 
 such cases as senile gangrene, &c.) have come to he regarded as among the 
 safest of major operations, and this is due mainly to the abolition of pyremia 
 and septiciEmia in the wards, from attention to all these various hygienic 
 •details. 
 
 The statistics of amputation of the thigh as given in one of the older 
 surgery books offer striking testimony to the difference in the condition of 
 hospitals now as compared with thirty years ago. Thus, in Mr. Erichsen's 
 
 * Surgery ' (4th edition, 1804), p. 31, a table is given of amputations of the 
 thigh for injury by various operations, in which the mortality is, for 
 primary amputations, about 74 per cent. ; for secondary amputations, 
 about 61 per cent. In Mr. Dent's recent paper on the mortality in 400 
 <;ases of amputations at St. George's Hospital, performed since 1874 {vide 
 
 * Med.-Chir. Trans.' for 18U0, vol. Ixxiii.) a table is given (p. 8G9) of thirty- 
 five cases of primary and secondary amputations for injury, with a mortality 
 of 62 per cent. At first sight this does not seem any very marked improve- 
 ment on the preceding, but when it is known that this table includes double 
 amjmtations, which were all fatal, and that part of the period referred to 
 includes cases in which antiseptic surgery was either not practised at all 
 ■or only very imperfectly attended to, it will be seen that the mortality repre- 
 sents a very considerable improvement on what has gone before. The 
 same relative improvement may be noticed by comparing the amputations 
 through the thigh (performed for disease) in the same hospital at different 
 periods. At this hospital careful statistics of the results of all the amputa- 
 tions have been kept since 1852. This period may be divided into two ^ 
 (corresponding with the dates of Mr. Holmes' and Mr. Dent's papers respec- 
 tively on the subject). The first period is from 1852 to 1874 ; the second from 
 1874 to 1888. During the first period, antiseptic surgery was mostly not 
 practised at all, though towards the end of the time very imperfect attempts 
 at its introduction were made. During the second period, the principles of anti- 
 septic surgery were much more fully understood and practised, though even 
 this includes some cases in the earlier years not so treated. In the first 
 period, the mortality of amputation of the thigh (for disease) amounts to 
 about 29 per cent. ; in the last period, to 16'9 per cent. The same 
 thing is to be observed in the amputations of the leg for disease. In 
 the earlier period 110 amputations gave a mortality percentage of 24*5 ; in 
 the latter period, in fifty-eight amputations, of 10'3. Again, in the amputa- 
 tion of the arm for accident, a mortality of about 88 per cent. ; in the 
 latter one, of 20 per cent. In the same amputation for disease, a mor- 
 tahty in the first period of about 14 per cent., against a mortahty of 
 per cent, in the second (10 amputations). Similar examples (obtained by 
 comparing the results given in the same papers) might be multiplied. The 
 writer may, however, be permitted to cite the results {loc. cit., page 363), in 
 which Mr. Dent compares all the amputations included together, but divided 
 into those performed at different ages. After gi\'ing a table (to which the 
 Avriter would refer those interested in the subject), he says : — ' The most 
 noticeable contrast will be observed in the third series of amputations, 
 between the ages of twenty and fifty. The mortality between the ages of 
 twenty and thirty, which in the first series amounted to 18"9 per cent., and 
 in the second series to 34-7 per cent., in the third has fallen to 14"7 per cent. 
 
 ' In the paper referred to, Mr. Dent divides the periods into tJiree, but for my 
 purpose this needlessly complicates and leuf^thens the subject. 
 
HOSPITAL HYGIENE 799 
 
 Between the ages of thirty and forty, the jfigures are still more striking, for 
 the mortality as shown in Table I., which in the first series was 39-6 per 
 cent., and in the second 40-4 per cent., has in the third series fallen to 14-2 
 per cent. Between the ages of forty and fifty, much the same results will 
 he observed. The improvement shown in the third series is chiefly due 
 to the diminished mortality in these three divisions.' 
 
 Still more striking becomes the individual experience of a surgeon 
 practising antiseptic surgery in a ward where all the other cases are treated 
 on the same principles. Selecting amputations of the thigh as a test case, 
 because the mortality in these is more striking than in the other amputations, 
 the writer has looked out all the cases in the hospital case-book for the years 
 1888-89-90 which have been operated on by him. He finds they amount to 
 twelve, all from disease, with only one death, and this was in an old man, aged 
 seventy- three, in whom the amputation had been done for senile ganq-rene* 
 with serious kidney and arterial disease. This gives a mortality of 8*4 per 
 cent. It is true that the number of amputations during these three years is 
 not large, ^ but the writer is very strongly of opinion that if the statistics of 
 previous years could be examined, the mortality would be found not higher 
 than this. During the three years, there have been also two cases of ampu- 
 tation at the hip-joint, which have both recovered. 
 
 Allusion has been made to the great diminution in the number of 
 erysipelas cases in the surgical wards of Guy's Hospital since the introduc- 
 tion of Listerism. Dr. Steele has been kind enough to obtain for the writer 
 the total number of cases admitted from the hospital wards into the isolation 
 wards (the so-called * erysipelas wards ') during the last four years. In round 
 numbers they amount to about twelve a year. But it must be added at once 
 that very few of these are erysipelas or blood-poisoning cases originating in 
 the toard. They are mostly foul cases (ulcers, gangrene, &c.), admitted as 
 such, and sent up at first into the general wards, and thence transferred at 
 the surgeon's first visit to the ' erysipelas ward.' On account of the limited 
 accommodation in this ward, it is a rule at Guy's Hospital that no case is to 
 be admitted to it from, outside, except under circumstances of great urgency, 
 and with the consent of the medical superintendent, but that the beds are 
 to be reserved for cases occurring in the hospital. When the ward, 
 therefore, is partly empty, the temptation to the resident staff to send 
 an urgent foul case into the general ward, or even one which is already show- 
 ing signs of blood poisoning, so that it may be passed into the erysipelas 
 ward, is very strong, and this accounts for the number of such cases 
 admitted. No record has been kept in the ' erysipelas ward ' (and it would 
 be very difficult for any Sister to do so) of the numbers of the two classes of 
 cases, viz., those originating de novo in the ward, and those admitted into 
 the general ward as foul cases, merely for the sake of being passed through 
 by the surgeon in the course of the first few days. So that for information on 
 this head the writer can only appeal to the individual experience of his own 
 ward. In Dr. Steele's return, he finds that during the whole four years 
 there were no cases admitted from Naaman ward (the male ward), that there 
 was one case admitted from Charity ward (the female ward), in eighteen 
 months, and one ^ from Accident ward in two and a half years. Neither of 
 these cases were cases originating in the wards, but came from outside, and 
 
 * The writer is not able to give the statistics of these amputations in the rears previous 
 to 1888, owing to a technical defect in the indexing of the hospital case-book, which has 
 since been remedied. 
 
 - In neither of these wards is the return sufficiently full to enable the writer to state 
 the number in the full period of four years. 
 
800 HYGIENE 
 
 passed throiigh the ward in the manner above described. As explaining the 
 total absence of cases from Naaman ward, it may be mentioned that the beds 
 are in great request, and nearly always promptly filled by a fresh case from 
 the country or elsewhere directly one falls vacant, so that the resident staff 
 have comparatively small chance of making use of these beds in the manner 
 before mentioned. 
 
 Such a fact as this justifies the statement that Listerism has nearly, if 
 not quite, ' abohshed erysipelas from our wards.' 
 
 Looldng at the matter from quite another standpoint, the improved 
 hygienic condition of the wards of large hospitals shows itself in the 
 diminished mortality of the large lying-in hospitals. It is not very easy to 
 obtain any exact returns of mortality in these hospitals in the years before 
 the introduction of antiseptic midwifery. In many places it was often so 
 high that no returns were published, and it is probable that none were even 
 kept. But it may almost certainly be assumed that we are putting it at a 
 very moderate estimate in stating that the deaths were 80 per 1,000, almost 
 entirely from septic causes, in the pre-antiseptic years. Very often it was 
 much higher than this. Thus Dr. Cullingworth states in a lecture delivered 
 in St. Thomas's Hospital (and reported in the ' British Medical Journal ' 
 for October 6, 1888, p. 743) that at the Paris Maternite the mortality from 
 1858 to 18G9 amounted to 93 per 1,000. In the New York Maternity 
 Hospital the deaths amounted to 60'6 per 1,000 from sepsis during 1883, 
 and in the Boston Lying-in Hospital to 55*5 and 45*8 per 1,000 in the years 
 1882 and 1883 respectively. This was just before the introduction of anti- 
 septics into midwifery, and in both the last hospitals the change in the 
 mortality is most striking. Thus in the New York Maternity Hospital the 
 mortahty fell in 1884 to 5-9 per 1,000, and in 1885 to 1'8. In the Boston 
 Lying-in Hospital the mortality fell in 1884 to 16 per 1,000, in 1885 to 6"4> 
 and in 1886 there were no deaths from sepsis. 
 
 Amongst the English lying-in hospitals the results at the General Lying- 
 in Hospital are best known, and most striking. To quote a table from the 
 same paper by Dr. Cullingworth : — 
 
 Table showing mortality at General Lying-in Hospital from 1833 to 1887. 
 
 Date 
 
 Deliveries 
 
 Deaths 
 
 Average mortality per 1,000 
 
 1833 to 1860 
 1801 to 1877 
 1880 to 1887 
 
 5,838 
 3,773 
 
 2,585 
 
 180 
 64 
 16 
 
 30-8 
 17 
 6 
 
 Thus the mortality has fallen from 17 to about 6 per 1,000 in the 
 last septennial period. Even this does not represent the full advantage 
 obtained. Since 1887 puerperal fever has almost entirely disappeared. 
 ' Only one death has taken place from this cause during the last three years, 
 and it has come to be regarded as quite an unusual event for a patient's tem- 
 perature during convalescence to exceed 100° Fahr.' 
 
 On the other hand, it is not possible in this and many other lying-in 
 hospitals to obtain full and accurate statistics of the exact mortality in the 
 pre-antiseptic days. ' Until the year 1887 this hospital was scarcely ever 
 free from puerperal fever, and the mortality, always high, occasionally 
 became fearful. In 1838, of seventy-one women delivered, nineteen died ; 
 in 1861, fourteen died out of one hundred and ninety-five ; and in 1887, nine 
 out of sixty-three. On several occasions the hospital had to be closed for 
 
HOSPITAL HYGIENE 801 
 
 long periods, and thousands of pounds were spent on the sanitary improve- 
 ment of the building ' (Cullingworth, loc. cit.). 
 
 These greatly improved results have been obtained partly by the use of 
 corrosive sublimate lotions (1 to 1,000) for the hands, instruments, such as 
 catheters, &c., and corrosive sublimate lubricants, e.g., mercuric chloride one 
 part dissolved in 1,000 parts of glycerine ; partly by attention to most of the 
 hygienic details enforced in the previous parts of this paper. Thus one of 
 the working rules is to allow only a certain number of confinements to take 
 place in a ward, after disinfection and cleansing ; thus giving practical appli- 
 cation to the remark which the writer has already quoted from the late Dr. 
 Mahomed, that in his experience at the Fever Hospital the mortality from 
 scarlatina was always less in those wards which had recently been re-painted 
 and cleansed. 
 
 The details respecting the successful working of the General Lying-in 
 Hospital have been recently very fully given in a paper read before the 
 Obstetrical Society by Dr. E. Boxall, on ' Fever in Childbed ' (vide ' Obst. 
 Trans.,' 1890, vol. xxxii., pp. 264-270). As the change in the mortality and 
 amount of fever in this hospital is so very remarkable, and as we possess all 
 the main facts during the last seven years, it will be worth while to give the 
 mode of successful working, as stated in Dr. Boxall's paper, the more so 
 as they form an effective commentary on much that has been already written 
 in this article. 
 
 The General Lying-in Hospital is a small one, containing only twenty- 
 four beds. It is divided into small wards, containing only three and four 
 beds each. Thus ' most of the lying-in wards have three beds each, one 
 rather larger than the rest has four, the convalescent ward four beds, and 
 the isolation ward one bed.' A clear space of 2,000 cubic feet is allowed for 
 each bed. There is a special ' labour ward ' on each floor for the reception 
 of one or if occasion require of two patients. 
 
 It should be said that no structural alterations have been made in the 
 hospital during the last seven years, so that the altered mortality can only 
 be attributed to the improved method of working the hospital. The hospital 
 was founded in 1765, occupies a site in a densely populated part of Lambeth 
 called ' The Marsh.' The structural alterations and sanitary improvements, 
 already referred to, were all made prior to the last septennial period. 
 
 The wards and ceilings of the wards are all painted. The floors are 
 partly polished, but the old deal floors were found unsuitable for this purpose, 
 so that with the exception of one ward recently laid with teak, the old mode 
 of cleansing has been maintained. 
 
 Closets and slop-sinks are provided on each floor, and are built out in a 
 turret so constructed as to include a passage shut off from the corridor by 
 doors, and ventilated by windows on each side. All the drains are outside 
 the building, and, together with the soil-pipes, are freely ventilated. The drains 
 are disconnected from the main sewer, and are flushed automatically every 
 twelve hours. 
 
 The ventilation and warming of the wards are practically done by means 
 of open fireplaces and open windows. Hot-air pipes were laid at great ex- 
 pense throughout the hospital some years ago, and an outlet ventilating 
 shaft was provided for each ward. These, however, worked so inefficiently 
 that for the last ten years they have been discarded. Fires are kept constantly 
 burning in the open grates, and all the windows are kept open at the top at 
 least six inches, and the inside Venetian blinds are turned so as to direct the in- 
 coming current of air upwards. Tobin's tubes are used in one ward, where the 
 windows are all on one side, and the ventilation is reinforced throughout by 
 
 VOL. I. 3 F 
 
80-2 HYGIENE 
 
 inlet ventilators near the floor and Sherringhani valves at the upper part of 
 the outer wall. 
 
 As regards the important elements of clothing and bedding, each lying-in 
 ward and delivery room is provided with its own set of instruments and 
 utensils. Hair mattresses are used. Both infants and mothers are provided 
 with special clothing during their stay in hospital, and the clothing which 
 the mothers wore on entrance is mostly taken away by the friends. This 
 was necessitated by an outbreak of scarlatina in the hospital, brought in from 
 outside, some six years ago. All lamidry work is contracted for outside the 
 hospital, and the clothes and bedding are despatched there three times a 
 week, without being previously disinfected or otherwise treated. But when 
 returned, the clothes are put into a Fraser stove and the temperature raised 
 to 250° Fahr. — ' more "snth a view to airing it efficiently than of efl'ectually 
 destroying infection.' Up to three years ago the mattresses used also to be 
 stoved, but as it was found impossible to keep them in the heat for a suf- 
 ficient time to destroy all possible infection without injuring the fabric, this 
 was discontinued. ' At the same time each mattress was numbered, and a 
 register was instituted of each patient for whom it was used, so that any 
 defect might be at once traced. Any mattress which has been used for a 
 case likely to infect it is, however, at once sent away in order to undergo dis- 
 infection by superheated steam.' 
 
 ' The labour wards are fumigated and washed after every six deliveries. 
 The lying-in wards are disinfected after the beds have been once occupied. 
 When a ward is vacated by a batch of patients, the bed linen is removed, but 
 the mattresses and blankets are suffered to remain suspended during the pro- 
 cess of fumigation and removed afterwards. Five pounds of sulphur are 
 burnt in the lying-in, and two pounds in the labour wards. The ceihng, 
 walls, floor, and bedsteads, &c., are then washed down with carbolic solution, 
 1 in 20. During the last three years, the fumigation has been performed 
 between each batch of patients, the additional washing between every other 
 batch. Before that, it was the practice to fumigate, to wash, and then to 
 fumigate again, not between every batch, but between every other batch of 
 patients {loc. cit., p. 267). 
 
 Nurses in attendance on cases outside the hospital are not permitted to 
 attend those in the hospital. While on duty within the hospital both mid- 
 wives and nurses are required to dress in washing material. Separate day- 
 nurses are provided for each ward, and a separate night-nurse for each floor. 
 The nurses assist at the labour cases in rotation. 
 
 The only patients considered unsuitable for admission are those with foul 
 wounds, which would entail risk to other patients. Patients are admitted 
 by letter ; they are usually ' more or less advanced in labour on admission, and 
 are conducted at once to the labour ward, where they are dressed in hospital 
 clothes, and in all cases, where time will allow, the passages are irrigated 
 with three quarts of antiseptic solution before delivery, the douche being 
 repeated if the labour be prolonged. One or more such vaginal douches at a 
 temperatm-e of 115° Fahr. are invariably given after labour is complete, and 
 any considerable tears about the vulva are immediately closed by suture.' 
 Two hours after delivery the patient is removed on a trolley to the lying-in 
 ward. A slop diet only is allowed until the bowels have been freely moved, but 
 fish is generally allowed on the third day, and afterwards meat. A liberal 
 supply of milk is allowed, but beer has been discontinued since 1884, as it 
 was found to make the patients feverish and uncomfortable for some hours 
 after having taken it. The patient's friends are allowed to visit her on two 
 
HOSPITAL HYGIENE 80a 
 
 afternoons in the week, after the fifth day, and the patient is allowed to get 
 up about the ninth day. 
 
 Antiseptics employed. — It has been already said that the great improve- 
 ment in the sanitary condition of the hospital dates from the employment of 
 mercuric chloride (corrosive sublimate) in the form of injections, washes, and 
 lubricants for the hands and instruments. Various other antiseptics have, 
 however, been used. Permanganate of potassium and carbolic acid were the 
 principal ones immediately prior to the advent of the mercuric chloride, and 
 they were attended with a very considerable measure of success. But these 
 two antiseptics are naturally antagonistic and destructive of each other, so 
 that their use together probably diminished the activity of both. Moreover, 
 they are both rather irritating to the mucous membranes, if used frequently 
 as injections, or if used for a long period. The same must also be said as 
 regards mercuric chloride, and cases have occurred of mercurial poisoning 
 from its use in the stronger forms. Probably from this arises the fact that 
 the solution is used frequently of strengths less than 1 to 1,000. Indeed, the 
 stronger form is only employed as a first injection, or when any special 
 circumstances arise calling for its use. The more frequent strength employed 
 afterwards is 1 to 2,000, and in some cases even as low as 1 to 4,000. As 
 corroboration of its irritant character on mucous membranes, the writer has 
 seen in surgical cases in general hospitals the employment of a strength of 
 1 to 1,000 on the mucous membrane of the mouth, rectum, or vagina, for 
 three or four days consecutively, cause great irritation and inflammation of 
 those membranes, so that he uses it only very sparingly for such operations. 
 On the other hand, it appears to have comparatively little irritant effect on 
 freshly cut tissues, so that it is more suitable for wounds than for use where 
 the mucous membranes are concerned. 
 
 Partly on account of this irritant action of mercuric chloride, the medical 
 staff of the General Lying-in Hospital sought for some other antiseptic, which 
 should not have the same irritant quality, while possessing equal antiseptic 
 value. With this view a systematic trial was given to salufer (silico-fluoride 
 of sodium), 1 to 500 solutions, as a part substitute for the mercuric chloride. 
 But it was found that during the period of trial the number of cases of 
 pyrexia during the pu.erperium rose considerably, and the average tempera- 
 tures were much higher than under the treatment by mercuric chloride, so 
 that it was abandoned, and the use of the latter was resumed. And it may 
 be added that this is the antiseptic which is still almost entirely used, and 
 that in spite of the occasional occurrence of mercurial poisoning, the risks of 
 sepsis are so much greater than those of mercurial poisoning that the 
 continued use of the mercuric chloride is more than justified. 
 
 It must be allowed that the patients admitted into a lying-in hospital 
 require peculiarly stringent treatment as regards antiseptic precautions. 
 From the maladies too often prevalent amongst them, such as gonorrhoea, 
 syphilis, and various forms of soft sore, to say nothing of their Habihty to 
 come from infected homes where scarlatina, measles, or other zymotic 
 affections are raging, such hospitals are more liable to outbreaks of puerperal 
 fever than other general hospitals are to erysipelas, pyemia, or other form 
 of blood-poisoning. The mucous membranes of the female during the 
 puerperium are peculiarly subject to the absorption of such poisons. It may 
 be, therefore, that some of the precautions necessary at such hospitals may 
 not be so necessary at general hospitals. Still in many respects the pre- 
 cautions found absolutely necessary at the general lying-in hospital might 
 probably be imitated advantageously elsewhere. Though many of the large 
 
 3f2 
 
804 ' HYGIENE 
 
 infectious disease hospitals of the Asylums Board, and others elsewhere, are 
 most ably managed, the writer thinks that there is room for improvement m 
 most of them in the future. The herding together of large numbers of in- 
 fectious cases must always be looked upon with suspicion from a hygienic 
 point of \dew. In some respects such hospitals might take a lesson from the 
 conditions of healthy working found essential in a lying-in hospital. The 
 Avriter would indicate two such points : — viz. (1) the treating of infectious 
 cases m small wards, containing each three or four patients, where they would 
 pass through the similar stages of the fever at the same time ; (2) the frequent 
 cleansing and disinfection of such small wards. This should be done, in his 
 opinion, after each batch of patients had vacated the ward, and it would be 
 rendered possible by the smaller size of the ward. Such disinfection would 
 probably contribute to the progress of the fever case itself, and would render 
 less likely and less frequent the spread of the fever amongst the medical 
 attendants and nurses. 
 
THE DISPOSAL OF KEFUSE 
 
 BY 
 
 W. H. COEFIELD, M.A., M.D. (Oxon.) 
 
 FELLOW OF THE ROYAL COLLEGE OF PHTSICLiNS ; PROFESSOR OP HYGIENE AND PDBLIO HEALTH 
 
 AT TTNIVBESITY COLTJIGE, LONDON ; MEDICAL OFFICER OF HEALTH FOR ST GEORGES, 
 
 HANOVER SQUARE ; EX-PRESIDENT OF THE SOCIETY OF MEDICAL 
 
 OFFICERS OF HEALTH ; HON. A.E.I.B.A. 
 
 AND 
 
 LOUIS 0. PAEKES, M.D., Dip. Public Health (Lond. Uniy.) 
 
 FELLOW OP THE SANIfARY INSTITUTE 
 
 ASSISTANT PROFESSOR OF HYGIENE AND PUBLIC HEALTH AT UNIVERSITY COLLEGE, LONDON 
 
 LECTURER ON PUBLIC HEALTH AT ST. GEORGE'S HOSPITAL 
 
 MEDICAL OFFICER OF HEALTH AND PUBLIC ANALYST FOE CHELSEA 
 
THE DISPOSAL OF EEFUSE 
 
 DEFINITION 
 
 The refuse of a community includes the dry refuse of the house (ashes, 
 dust, and refuse food), the f^ees and urine of men and animals (the excretal 
 refuse), and the waste waters from cooking and washing in houses. All 
 these matters are the waste products of the individual house or estabHsh- 
 ment ; but in all towns the municipal authority must make arrangements 
 for the collection, removal, and disposal of the liquid and solid waste sub- 
 stances from stables, cowsheds, and slaughter-houses, the sweepings of the 
 streets and markets, and the waste waters from works and factories, in 
 addition to the more strictly domestic waste matters. 
 
 Methods of Bemoval. — Some of this refuse material being in a more or 
 less solid or dry condition may be removed by mechanical labour ; and in 
 many towns in this country the municipal scavenging department undertakes 
 the collection and removal of the dung from stables, the ashes, dust, and 
 food scraps from houses, and the sweepings from the streets and markets. 
 In some towns human faeces and a certain amount of urine are also removed 
 by this method, after being deposited in dry closets or privies. The system 
 is still largely in use in the towns of the midland and northern counties. 
 Necessarily scavenging operations, as usually conducted, fail to deal with any 
 but the more or less solid refuse ; consequently the house waste waters, the 
 rain water from roofs, paved yards, and streets, the liquid drainage from 
 stables, and the waste hquors from manufactories, must be carried away from 
 the houses in drains, and from the town in sewers ; in other places the 
 excretal matters are collected in underground cesspools, which are emptied 
 from time to time. These are known as the conservancy systems of excretal 
 removal, the refuse matters being necessarily kept for a certain period in or 
 near to the house. 
 
 Most towns in this country have long been provided with drains and 
 sewers for carrying off the liquid wastes, and the rain water which falls over 
 the surface covered by streets and buildings ; and it soon came to be recog- 
 nised that there was a distinct advantage in removing the solid human 
 excreta as well in this manner. For by carrying these substances away in 
 drains and sewers, the most offensive and dangerous portions of the human 
 refuse matters were removed at once from the neighbourhood of houses, and 
 the necessity for retention on the house premises, which is the very essence 
 of all conservancy systems, was thereby avoided. This system of removal of 
 excreta by water carriage from the neighbourhood of houses and to"^\Tis is, 
 where circumstances are favourable to its execution, the one best suited to 
 our national habits, and, sanitarily considered, is far preferable to any con- 
 servancy system. 
 
808 HYGIENE 
 
 REMOVAL OF DUST, ASHES, AND EEFUSE FOOD 
 
 Arrangements must be made by the sanitary authority for the removal 
 of household dust, ashes and cinders from fires, scraps of waste food, and 
 other refuse matters. Inasmuch as these substances can only be removed at 
 intervals from the houses where they accumulate, it is important that they 
 should be so stored and kept as to remain inofi'ensive during their period of 
 retention on the premises. The dust and ashes, being in great part mineral 
 substances, are not likely to give rise to any nuisance, but the organic matters 
 contained in the scraps of refuse food will ferment, putrefy, and cause 
 serious nuisance unless suitable precautions are taken. Obviously the first 
 indication is to limit, as far as possible, the quantity of these waste organic 
 substances that must be stored on the premises to await removal by the 
 scavengers. In well-organised households all those waste matters that can 
 be destroyed by heat may be burnt in the kitchen fire. Such as are in- 
 destructible must be placed with the ashes and dust in the dustbin. 
 
 Until quite recently, dustbins were large receptacles constructed of brick- 
 work, backing upon a wall in the yard, or against the side of the house, 
 "v\T.th an opening above protected by a wooden cover, and a door at the side 
 for removal of the contents. The cover being liable to removal, the contents 
 of the dustbin were often exposed to rain ; the water saturated with noxious 
 organic substances penetrated into the ground or into the brick walls of the 
 house, against which the dustbm was placed, and in summer the combination 
 of heat and moisture caused rapid decomposition of the organic substances, 
 mth evolution of offensive and injurious gases. 
 
 These disadvantages of the old-fashioned brick dustbin have caused it to 
 be largely replaced by small galvanised iron pails, which should be provided 
 with a properly fitting metalUc cover, in order to ensure dryness of the 
 contents. If the contents are properly dry, fermentation and the production 
 of offensive gases is avoided, even although the temperature of the air is 
 high. The iron pails being non-absorbent, their walls are not saturated with 
 foul organic substances as are the walls of brick dustbins ; and being easily 
 movable the pails may be placed in such a position as to cause least offence 
 to the mmates of the house, and are easily carried by the scavengers to the 
 dust cart, into which their contents are at once emptied. In several parishes 
 of London the local authorities have now gratuitously provided every house 
 with a galvanised iron pail to replace the brick or wooden dustbin, and the 
 excellent sanitary results of this system more than counterbalance the initial 
 expense. 
 
 As frequent a removal as possible of the dustbin contents is greatly to be 
 desired. A daily removal is what should be aimed at ; but this would involve 
 considerable expense, and it is not usually found practicable to carry out more 
 than a bi-weekly removal. In many places the dust carts only call nominally 
 once a week, and in reahty at many houses of the parish or district at even 
 longer intervals. It is certamly to be recommended that during the summer 
 months the removals should be effected twice as often as in winter. 
 
 Specially constructed carts should be employed in the removal of dustbin 
 refuse, and they should be provided with a cover, to prevent the diffusion 
 into the air of the streets of particles of dust, which, if derived from a fever- 
 stricken house, may be the means of scattering infection broadcast. 
 
 A list of the matters which may be placed in the pails or dustbins for 
 collection should be issued by the local authority to every householder. This 
 list should include cinders, ashes, potato peelings, cabbage leaves, and kitchen 
 
THE DISPOSAL OF REFUSE 
 
 809 
 
 refuse generally ; but instructions should be given that, wherever possible, as 
 in large houses with good kitchen ranges, kitchen refuse should be burnt. 
 Trade and manufacturing refuse, refuse building materials, and garden 
 sweepings and cuttings, should be excluded from the list of what the local 
 authority is bound to collect. 
 
 It is the almost universal experience that the dust collection is far more 
 efficiently performed when in the hands of the local authority, and worked by 
 their own officials, than when let out to contractors. Dust is no longer a 
 marketable product as it was som« years ago ; consequently it is no longer in 
 the interest of the contractor to collect as much as possible each day, but 
 rather, as he is now paid to do what he formerly paid for the privilege of 
 doing, it is his interest to do as little as possible. 
 
 The ultimate disposal of the dustbin refuse is a matter for the serious 
 consideration of local authorities. The old system still obtains at many 
 places of carrying the refuse to a large sorting yard, often in close proximity 
 to inhabited houses. Here men and women are employed in sorting the 
 refuse and separating it into breeze (cinders and small particles of coal), 
 hard core (bottles, bones, crockery, metal pots, and pans), and soft core 
 
 From " Engineering," January 21st, 1881. 
 Pig. 162. — Fryer's Destructor funiace. 
 
 (animal and vegetable organic matters and textile substances). The breeze 
 is sold to brickmakers ; the hard core, or such parts of it as are worthless, 
 is used in road making ; and the soft core is mixed with fish offal, market 
 sweepings, and horse droppings, and sent into the country to be sold as 
 manure. The whole process of sorting is a noxious one, and degrading to 
 the workpeople ; and the foul odours given off during the process, and also 
 from the heaps of refuse awaiting removal, whilst fermentation and de- 
 composition are at work, often prove a most serious nuisance to the sur- 
 rounding neighbourhood. 
 
 More recently it has been attempted to destroy the dustbin refuse in a 
 Destructor furnace (see figs. 162 and 163). The proportion of cinders in the 
 refuse is quite sufficient to ensure its complete combustion in a properly 
 constructed furnace ; but it has been found that a small amount of unburned 
 or partly burned vapours, and a very fine dust, are liable to be carried off with 
 the products of combustion, which escape into the air from the chimney. 
 The unburned vapours impart to the escaping gases an/)ffensive smell, which 
 is perceptible to those living in the neighbourhood of the Destructor ; and 
 the dust is deposited on surrounding objects, and becomes also a subject of 
 complaint. To ensure the complete combustion of the vapours and dust, a 
 
810 
 
 HYGIENE 
 
 
 _3f_ 
 
 SecUoTv at R s\ 
 
 From Engineering," -January 
 
 Fig. 163. — Fryer's Destructor furnace. 
 
 Cremator furnace may be introduced at the foot of the chimney through 
 which all the smoke from the Destructor furnace must pass. In this cre- 
 mator unburned vapom's and solid particles are completely burned up before 
 they can enter the chimney flue. 
 
 At Bradford a fume cremator of this description (Jones's patent) has 
 been introduced into the Destructor.' The gases from the Destructor furnace 
 
 are made to pass over a coke fire 
 on a grate, in a furnace covered 
 in by a firebrick arch. The coke 
 is fed in by openings at the top, 
 and the fire is stoked through 
 doors in the ordinary way. In 
 this furnace are a series of fire- 
 brick arches or projections, called 
 bafflers, which ensure that the 
 gases shall not only be exposed to 
 a great heat, but that they shall 
 be exposed for a sufficiently long 
 time. In the Bradford Destruc- 
 tor steam injections (Horsfall's 
 method) are used to increase the 
 draught in the furnace of the De- 
 structor. A jet of steam under considerable pressure is forced underneath 
 the fire-bars by means of a funnel attached to steam pipes leading from a 
 boiler, which is itself heated by the combustion of the refuse. The steam 
 jet causes a great inrush of air, thereby increasing the draught in the furnace 
 and causing a more complete combustion of the refuse. After leaving the 
 cremator the gases are carried under the boilers and finally into the chimney, 
 which is 180 feet in height. 
 
 Jones's Fume Cremator is in use for the Destructor furnace at Ealing. 
 Besides consuming the dustbin refuse, this Destructor burns up the sludge 
 produced by chemical treatment of the sewage of the town. The sewage 
 sludge — which is an unsaleable product — after losing about 25 per cent, of 
 its moisture by draining, is mixed with about two-thirds its volume of dust- 
 bin refuse, and then burned in the furnace. 
 
 In other towns the combustion of the refuse in Destructor furnaces has 
 been made available for generating steam in boilers, for the manufacture of 
 manure from human excreta (pail contents), for driving electric lighting 
 machinery, and for other municipal purposes. The clinkers when withdrawn 
 from the furnace can be ground down in a mortar-mill and converted into 
 mortar, bricks, or concrete. 
 
 Sanitarily considered, the destruction by heat of the dustbin refuse is 
 far preferable to the sorting method, and economically, where circumstances 
 are favourable, it may very possibly be found to pay expenses. 
 
 HUMAN EXCBETA 
 
 The table on the next page (Lawes) gives the average amounts, in ounces, 
 of fffices and urine passed daily by an adult male (15 to 50 years of age). 
 
 Eoughly speaking, an adult male, living on a mixed diet of animal and 
 vegetable food, may be assumed to pass four ounces by weight daily of 
 solid faeces, and 45 to 50 fluid ounces of urine. Taking all ages and both 
 
 See paper by Dr. MacLintock in Public Health, December 1889. 
 
THE DISPOSAL OF BEFUSE 
 
 811 
 
 sexes, the daily amount of excreta per head of a mixed population may be 
 assumed to be 2*5 ounces of fasces and 40 ounces of urine (Parkes). 
 
 - 
 
 Pj'e=h 
 Exeremcuts 
 
 Dry 
 Substance 
 
 Mineral 
 Matter 
 
 Carbon 
 
 Nitrogen 
 
 Phosphates 
 
 Faces . . . 
 Urine . . . 
 
 4-17 
 46-01 
 
 1-041 
 1-735 
 
 0-116 
 0-527 
 
 0-443 
 0-53U 
 
 0-053 
 
 0-478 
 
 0-0G8 
 0-189 
 
 Total . . 
 
 50-18 
 
 2-776 
 
 '■ 0-643 
 
 0-982 
 
 0-531 
 
 0-257 
 
 From the table it will be seen that human fusees when fresh contain 
 about 25 per cent, of dry solids, and that the urine contains about 3'8 per 
 cent, of dry solids, of which rather more than half (54 per cent.) is urea. A 
 given weight of feece-s is as a manure more valuable than the same weight of 
 urine, in the proportion of about 10 to G ; but the weight of the urine passed 
 daily by an individual of a mixed population is sixteen times as great as that 
 of the faces ; consequently the urine passed by an individual in twenty-four 
 hours is worth ten times as much as the faeces passed in the same time, the 
 nitrogen being no less than nine times, and the phosphates nearly three 
 times, as much by weight in the daily urine as in the daily faeces. 
 
 Messrs. Lawes and Gilbert have calculated that the average amount of 
 ammonia voided annually by an individual of a mixed population of both 
 sexes and all ages is in urine 11*32 lb. ; in faeces 1*64 lb. : total 12-96 lb. The 
 money value of the total constituents (ammonia, phosphates, and potash) is 
 in urine 7s. dd. ; in faces Is. 2|(i. : total 8s. 6|cZ. But in calculating the 
 value of sewage it is better to take the annual excretion of the individual as 
 being equivalent to 10 lb. of ammonia, worth 6s. 8^., more especially as it 
 was stated by the late Dr. Voelcker that nitrogenous organic matters (in 
 which form the nitrogen of sewage principally exists) are worth considerably 
 less than ready-formed ammoniacal salts. It is also evident that it must be 
 impossible to realise practically any such value, because it is impossible to 
 collect the whole of the urine and faeces unmixed with other substances, 
 which greatly detract from the value because they are agriculturally worth- 
 less. 
 
 WASTE WATEES 
 
 The waste waters from houses contain much foul organic matter. The 
 kitchen sink waters are highly charged with decomposable organic matters, 
 especially grease ; and the slop-waters contain urine, soap, and dirt from the 
 surface of the body and from clothes. 
 
 The waste liquors from manufactories are of very variable constitution. 
 Some of them are very rich in manurial ingredients — e.g. the waste water 
 from flannel washing was stated by the Rivers Pollution Commissioners to be 
 twenty times more valuable as a manure than London sewage. 
 
 These waste waters, when mixed with rain water from the roofs of houses 
 and from paved surfaces, with the liquid drainage from midden pits or cess- 
 pools, stables, cowsheds, and slaughter-houses, and with the urine from pubhc 
 urinals, form the sewage of the non-water-closeted or midden tovnis. Such 
 sewage from being stale is decidedly more offensive than that of water-closeted 
 towns, which contains the solid human excreta as well. In the first report 
 of the Eivers Pollution Commissioners it is stated that there is ' a remarkable 
 similarity of composition between the sewage of midden towns and that of 
 water-closet towns. The proportion of putrescible organic matter in solu- 
 
812 HYGIENE 
 
 tion in the former is but slightly less than in the latter ; whilst the organic- 
 matter in suspension is somewhat greater in midden than in water-closet 
 sewage. For agricultural purposes ten tons of average water-closet sewage 
 may, in round numbers, be taken to be equal to twelve tons of average privy 
 sewage.' The same report also shows that more persons contribute to a 
 given volume of sewage in midden towns than in water-closet towns, because 
 it is found that the proportion of chlorine is greater in the sewage of the 
 former towns than in that of the latter, the cause of this difference being the 
 increased quantity of water needed by and supplied to the water-closet 
 towns. 
 
 Such being the case, it is necessary to bear in mind that in towns where 
 there are middens, or some form of dry closet for the collection of ftecal 
 matters, there is also the liquid sewage to be conveyed away from the houses 
 by drains and from the town by sewers, which sewage is too impure to be 
 admitted into a stream, and must therefore be purified before being so dis- 
 charged. 
 
 CONSERVANCY SYSTEMS 
 Middens 
 
 Until comparatively recent times open midden heaps and pits were, in 
 town and country alike, the almost universal receptacles for the excretal and 
 other waste matters of the habitation. On the midden heaps the excrement 
 was allowed to accumulate, and to diffuse itself from thence for an unlimited 
 time, or until it was required for manure. The disgust excited by these large 
 accumulations of filth above the surface of the ground eventually led to the 
 practice of digging shallow pits in the yards and courts about houses, over 
 which was erected some primitive form of privy. The intention was that 
 the contents of the pits should be removed as soon as they were full ; but too 
 often they were allowed to overflow, when the filthy liquids found their way 
 into the cellars of houses or saturated the ground in their vicinity. In any 
 case, being unprotected from rain, the water soaked through the more or less 
 sohd midden contents, and percolating through the surface layers of the soil 
 poisoned the water in the neighbouring wells. 
 
 The institution of middens, i.e. the setting aside of a special locality where 
 the refuse matters of a house might be deposited, was no doubt an improve- 
 ment on the state of things which existed in an even more primitive condition 
 of society, where no special places being allotted for such purposes excrement 
 was deposited in any convenient or inconvenient locality. But the pesti- 
 lential odours that arose from the festering midden heaps and pits, the pol- 
 lution of the soil around the houses, and the contamination of the wells, were 
 the cause of much of that epidemic prevalence of cholera and fever which 
 was characteristic of the last century and the first half of this, and which 
 experience has shown to be so eminently preventable by improved methods of 
 excretal disposal. That such abominations still exist in many places in this 
 country is only too true. The immense advance, however, in sanitary 
 enlightenment has already effected enormous improvements, and it is hkely 
 that the loathsome middens which were formerly so universal will soon be 
 utterly abolished. 
 
 Various improvements have from time to time been attempted upon the 
 old-fashioned form of midden pit. These improvements had for their object 
 (1) the removal of the midden from the iminediate neighbourhood of the 
 house ; (2) a reduction in the size of the pit, so as to limit the accumula- 
 
THE DISPOSAL OF BEFUSE 
 
 813 
 
 tion of foul matters, and the lining of the pit walls with brickwork and cement 
 so as to render them impermeable and prevent the saturation of the soil with 
 foul liquids ; (3) the preservation of the midden contents in a dry condition 
 {a) by roofing over the pit so as to prevent any entry of rain, (b) by admixture 
 of the excreta with ashes, and (c) by connecting an overflow pipe with a sewer 
 or ditch so as to drain off the more fluid portions. 
 
 The provision of an overilow pipe to middens and cesspools when con- 
 nected with sewers has been found productive of so much nuisance that it 
 is now almost everywhere prohibited. The putrid fluid from middens thus 
 introduced into the sewers carried so much ashes with it as to cause foul 
 deposits, which gave rise to the most offensive gases, and eventually tended 
 to cause a complete stoppage. Besides, if the middens or cesspools cannot 
 be worked without connection with the sewers, it is difficult to see wherein 
 their use lies. For the midden or cesspool drainage pollutes the sewers to an 
 equal, if not to a greater extent than water-closets, whilst the receptacles 
 themselves retain the 
 filthy solids on the pre- 
 mises of the house, when 
 they might with greater 
 advantage be conveyed 
 straight to the sewers. 
 
 Most modern regula- 
 tions require that the 
 midden pit, qua a hole 
 dug into the ground, 
 should be abolished alto- 
 gether, and that for the 
 pit should be substituted 
 merely the space inter- 
 vening between the seat 
 of the closet and the 
 floor. In nearly all towns 
 where middens are re- 
 tained they are now re- 
 quired to be constructed 
 according to certain defi- 
 nite rules. The Model 
 Bye-laws of the Local 
 
 Government Board for the construction of privies and middens in new build- 
 ings are to the following effect : — 
 
 The privy (fig. 164) must be at least six feet away from any dwelling, and 
 forty or fifty feet away from any well, spring, or stream ; means ot access 
 must be provided for the scavenger, so that the filth need not be carried 
 through a dwelUng ; the privy must be roofed to keep out rain, and provided 
 with ventilating openings as near the top as practicable ; that part of the 
 floor of the privy which is not under the seat must be not less than six 
 inches above the level of the adjoining ground, must be flagged or paved with 
 hard tiles, and must have an inclination towards the door of the privy of 
 half an inch to the foot, so that any liquids spilt upon it may run outside 
 and not fiiud their way into the receptacle under the seat ; the capacity of 
 the receptacle under the seat of the privy must not exceed eight cubic feet — • 
 a weekly removal is then necessitated ; the floor of this receptacle must be 
 in every part at least three inches above the level of the adjoining ground ; 
 the sides and floor of this receptacle must be constructed of impermeable 
 
 Fig. 164. — Privy constructed in accordance with Model 
 Bye-laws of the Local Government Board. 
 
814 
 
 HYGIENE 
 
 materials : they may be flagged or asphalted, or constijicted of 9-incli bricK- 
 work set and rendered m cement ; the seat must be hinged, or other means 
 of access to the contents of the privy must be prouded ; and the receptacle 
 must net communicate with any drain or sewBr. 
 
 When middens are constructed according to these rules, there is little 
 danger of percolation of liquid filth into the soil around houses, and in the 
 neighbourhood of wells. The pollution of the air by the excreta is re- 
 duced to a minimum, if their dryness is ensured by the proper application 
 to them of ashes and cinders, and no slop-waters are thrown in. During 
 removal, however, some offensive effluvia must of necessity escape into the 
 air. The success of the system depends to a large extent on efficient inspec- 
 tion by the sanitary officers, and on proper scavenging arrangements. 
 
 There can be no doubt, however, about the fact that any form of midden 
 is unadvisable, from the great expense of scavenging and the inconvenience 
 caused by the frequent \dsitations of the scavengers, especially as they have 
 to disturb the contents of the middens in digging them out. These frequent 
 visitations are most unpopular, and any plan which makes such visits as 
 infrequent and as short as possible, or does away with them altogether, is 
 sure to be greatly preferred. 
 
 The Pail System 
 
 We have seen that middens can only be tolerated when so reduced in 
 size as merely to constitute the space between the closet seat and the floor. 
 It is obvious that middens of this limited capacity may most advantageously 
 be replaced by movable receptacles, such as pails or tubs, placed under the 
 closet seat for the reception of the excreta. The removal of the excreta is 
 thereby greatly facilitated, and there is no pollution of the air from disturb- 
 ance of the contents of the pails, as there always must be when the contents 
 of middens are dug out and conveyed to the night-soil carts. On the arrival 
 
 Fig. 165. — Rochdale pail. 
 
 Fig. 166. — Rochdale pail, with Haresceugh'i 
 spring lid. 
 
 of the scavenger the lid of the pail is adjusted, the pail is taken out to the 
 scavengers' cart, and a clean empty one is left in its place. 
 
 The pails (figs. 165 and IGG) may be of galvanised iron or tarred oak : they 
 should be provided with close-fitting lids, which hermetically seal the pails 
 and prevent any leakage or escape of effluvia at the time of their removal 
 to the scavengers' carts, when the contents are unavoidably liable to some 
 disturbance ; and the capacity of each pail should not be greater than 
 two cubic feet. They should, of course, be very strongly constructed, and 
 capable of resisting the rough usage to which they may be subjected, as well 
 
THE DISPOSAL OF BEFUSE 815 
 
 as be perfectly water-tight. On the whole, tarred oak pails have been found 
 to answer better than galvanised iron ones, as they are less expensive, last 
 longer, and are far more easily repaired. When the pails have been emptied 
 of their contents at the town depot, they should be well washed with water, 
 jetted out of a hose under high pressure, and subsequently disinfected with 
 chlorinated lime. Wooden pails require retarring every two or three months. 
 The structure of the closet may be very similar to that described as 
 recommended for a midden closet. It should be well roofed, the roof being 
 provided with louvres for ridge ventilation, and the door should be so con- 
 structed that, when closed, open spaces may be left above and below for light 
 and ventilation. The floor should be raised above the level of the adjoin- 
 ing ground and flagged, and the pail placed on the floor under the seat. The 
 seat may be hinged to ensure a more complete covering of the excreta with 
 house cinders and ashes, when these are used, and to allow of the pail being 
 removed ; or the back wall of the closet may be provided with a door to effect 
 the latter purpose. The pail should be removed at not longer intervals 
 than once a week, and a clean one substituted for it, this plan being far 
 preferable to that of emptying the pail contents into the night-soil cart, and 
 then replacing the pail after a more or less perfunctory attempt to clean it. 
 
 From a sanitary point of view it is most important that the pail contents 
 (fffices and urine passed at the time of evacuation) should be kept as dry as 
 possible. A dry condition can only be effected by adding to the pail contents 
 some dry and absorbent substance such as ashes, charcoal, or dry earth, or 
 by lining the pail with some absorbent material. Left to themselves, the 
 mixed fseces and urine in the pails are in a more or less liquid condition, 
 and rapidly tend to undergo putrefactive changes, giving rise to the forma- 
 tion of fo3tid gases (organic vapours and compounds of sulphur and ammonia). 
 If, however, it is intended to create a saleable manure, ashes, charcoal, or 
 earth should not be used, and all kitchen refuse and garbage should be kept 
 out of the pails, as it is most essential to collect the faeces and urine in 
 as pure a condition (i.e., unmixed with valueless substances) as possible. In 
 such cases the pail contents cannot be kept dry, and sanitary considerations 
 are sacrificed to ensure commercial profits. 
 
 In some towns, such as Nottingham, the authorities find it convenient to 
 remove all the solid house refuse in one receptacle, so that the pails become 
 the receptacles for the solid kitchen refuse, dust and ashes, as well as for 
 the excreta. Here, of course, commercial profit from the sale of manure is 
 not looked for, but the town being situated in the centre of an agricultural 
 district there is no difficulty in disposing of the manure, such as it is. 
 
 By keeping the chamber urine out of the pails, much fertilising material 
 is excluded, as the chamber urine constitutes at least nine-tenths of the- 
 total daily excretion of urine. But it would be impossible to keep the pail 
 contents dry if chamber slops were thrown in, and these must, therefore, be 
 carried away from the houses in drains with the other waste waters. It has 
 even been attempted to separate the urine passed at the time of evacuation 
 from the faeces, in order to ensure dryness of the pail contents. These 
 ' urine- separators ' have, however, not been found to answer their purpose, 
 and they are more especially undesirable, inasmuch as they introduce a com- 
 plication into a system the chief merit of which is its simplicity. 
 
 In the Goux system it is attempted to secure dryness of the excreta by 
 lining a wooden tub (fig. 167) with a layer of refuse sawdust, shoddy, tan, or 
 other absorbent material, to which is added a little soot, charcoal, gypsum, 
 or other dryer or deodoriser. These matters are pressed closely to the bottom 
 and sides of the tub by means of a cylindrical mould (fig. lG8j, which is after- 
 
816 
 
 HYGIENE 
 
 1' 8" 
 
 wards witbdrawn. leaving a ca%-ity in the centre of tlie materials for the 
 reception of the excreta. On no accoimt should chamber slops be thrown 
 into the tubs, and the tubs themselves should only be in use for two or three 
 days, otherwise the absorptive capacity of the lining materials is exceeded, 
 
 and the tubs will be 
 found to contain liquid 
 dejections. The sys- 
 tem has been in use 
 at Halifax, and on 
 the whole has worked 
 well, the closets, when 
 well managed, being 
 generally found clean 
 and free from otieusive 
 smells. House ashes 
 and dry rubbish are 
 collected in a separate 
 pail, so that the tub 
 contents are merely the excreta in a more or less pure condition. 
 
 As before stated, another method to ensure the dryness of the excreta is 
 the addition of ashes, charcoal, or dry earth m suitable quantities to the 
 contents of the pails after each use of the closet. These substances not 
 
 -Goux pail 
 
 Fig. 108.— Goux mould. 
 
 Monncu.* IptrcNT. of IU«7 
 
 ^ S-of — — -<i 
 
 Fig. 169. — Morrell's cinder-sifting ash closet. The soil pail is removed through a side wall- 
 
 only act as dryers, but very largely also as deodorisers, so that ash, charcoal, 
 or earth closets, if rightly used, are far less offensive than the pail closets 
 where these substances are not in use. 
 
 Ash Closets 
 
 Sifted house cinders and ashes may be collected in a box and 
 thrown by a handscoop into the pail after each use of the closet ; or by 
 a mechanical arrangement of sieves fixed in a hopper placed above and 
 
THE DISPOSAL OF BEFUSE 
 
 817 
 
 behind the pail, the cinders may be sifted and the fine ash deposited auto- 
 matically on the pail contents by means of a self-acting seat arrangement, 
 or the same result may be accomplished by pulling up a handle (figs. IGD 
 and 170). The cinders which 
 do not pass through the sifter 
 may be used again as fuel. 
 When properly sifted, the fine 
 ashes form very efficient de- 
 siccators and deodorisers ; 
 moreover, they are always 
 to be found on the premises 
 of any house, unlike charcoal 
 or dried and sifted earth, anrl 
 they would have to be removed 
 in any case by the sanitary 
 authority. 
 
 Charcoal Closets 
 
 Fig. 170. — External view of Morrell'B ash closet, show- 
 ing opening, a, for putting in ashes, and door, b, for 
 removing sifted cinders. A door may be made at c 
 for removing the soil pail. 
 
 Wood charcoal and a char- 
 coal obtained by carbonising 
 sea-weed have been used instead 
 
 of ashes. The same kind of closet, with an automatic apparatus for supply- 
 ing the charcoal, is suitable as for the ash closet, or a box and scoop may 
 be used. Of the sea- weed charcoal (Stanford's process) it is stated that only 
 •^Ib. is necessary for each use of the closet, and this is found to be equiva- 
 lent in deodorising power to 1^ lb. of dry earth. The charcoal itself contains 
 63 per cent, of carbon, 34 per cent, of ash, and only 2"6 per cent, of water. 
 On removal from the closet the mixed charcoal and excrement may be re- 
 carbonised by burning, and may then be again used for the same purpose. 
 The products of distillation from the recarbonisation process when condensed 
 consist of ammoniacal liquor and tar, and from the liquor sulphate of am- 
 monium and acetate of potassium can be obtained. After several uses in 
 the closet the charcoal becomes highly chargecl with potash and phosphates, 
 and when mixed with the ammonia distilled from it forms a very valuable 
 manure. 
 
 Neither charcoal nor ashes have any such disintegrating action on the 
 excreta, as we shall see further on the dry earth has. A section through 
 the contents of an ash or charcoal closet pail shows the excrement retaining 
 its form, and the paper unchanged, but the whole mass is dry and odourless. 
 Nevertheless any assumption that mixed excrement and charcoal or ashes 
 may for this reason be safely stored for long periods of time in the vicinity, 
 or within the precincts, of houses would be entirely unwarranted. The 
 only safe plan is to arrange for as frequent removal of the contents of ash 
 and charcoal closets as of the simpler pail closets. 
 
 There can be little doubt that Stanford's sea-weed charcoal is far more 
 efficient than ordinary sifted house ashes. On the other hand, a system of 
 charcoal closets would be far more costly to maintain. There is the cost of 
 manufacture of the charcoal and its conveyance to every house, and this is 
 likely to greatly exceed any returns that may be obtained by distilling the 
 mixed excrement and charcoal and selling the products so obtained. 
 
 In order to deodorise the contents of pails in which excreta are collected, 
 it has been proposed to add a mixture of soot and salt, which has been fomid 
 very effective for this purpose, although its drying action is practically nil, 
 
 VOL. I. 3 G 
 
818 
 
 EYGIEXE 
 
 Fig. 171. — Stove for drying earth. 
 
 Eaeth Closets 
 
 It has long been known that earth of suitable quality is a very efficient 
 deodoriser of^excremental matters. For centuries past the Chinese have 
 been accustomed to collect with extreme care all human excremental matters, 
 and to convey them to their fields for enriching the earth, knowing tis they 
 
 do the valuable fertilising 
 ingredients contained in the 
 excreta. And in this custom, 
 originated ])y the thoughtful 
 thrift for which the Chinese 
 are famous, is also contained 
 the practical application of 
 the sanitary rule, ' the sew- 
 age to the soil,' which is the 
 highest development of our 
 most enlightened views on 
 the utilisation of human 
 refuse. Not only is the 
 earth the better for the 
 sewage, which returns to it in an assimilable form the nitrogen and inorganic 
 salts taken away in the crops, but on a large scale the earth is the only sub- 
 stance available for converting the noxious products of human and animal 
 excretion into inoffensive and useful matters. 
 
 The dry earth system, the invention of the late Rev. Henry Moule, is, 
 however, the very reverse of the plan upon which all the other systems pro- 
 ceed. It proposes to bring a certain quantity of earth to the manure, while 
 
 all the others take the manure in some 
 form or another to be placed upon the 
 earth ; in other words, a sufficient quan- 
 tity of dry earth is to be brought into 
 every community where this system is at 
 work, to completely deodorise and render 
 inoffensive all the excremental matters of 
 the population. 
 
 The best kinds of earth for the pur- 
 pose are loamy surface soil, vegetable 
 mould, brick earth, and dry clay. Sandy, 
 gravelly, and chalky soils are not efficient 
 deodorisers. The earth must be dried 
 before use over a stove (fig. 171) or on a 
 hot floor, and then passed through a 
 riddle or sieve (fig. 172), so as to thoroughly 
 sift it, the finer portions only being used. 
 For large communities these operations 
 should be conducted at one spot, and on 
 . an extensive scale ; but for separate esta- 
 blishments, such as houses or institutions 
 in the country, each household would 
 have to prepare its own earth. 
 The excreta are deposited in a pit of an approved sort, or in a pail (fig. 173) 
 or tub placed under the closet seat, and 1| lb. of dried sifted earth must 
 be applied in detail— i.e. each particular stool must be covered at 
 once with this quantity as soon as deposited. This quantity (1^ lb.) is 
 
 Fig. 172.— Earth-sifter. 
 
THE DISPOSAL OF BE FUSE 
 
 819 
 
 sufficient to remove all 'omell from the stool, and to form a compost with it 
 which remains inoffensive as long as it is dry. Less earth than the above 
 •specified amount is said to be insufficient, 
 whilst more is useless. A certain action takes 
 place in the intimate mixture of earth and 
 •excrement which results in the complete dis- 
 integration of the faBcal matters. After a 
 time, excremental matters, and even paper, can 
 no longer be detected as such in the mixture. 
 After keeping and redrying the compost so 
 formed, it may be used over again in the 
 closet, and has the same action as the original 
 dry earth ; but inasmuch as this repeated use 
 does not increase in a corresponding degree 
 the manurial value of the compost, there is no 
 particular advantage in doing so from an Pig. 173.— Pail holding twenty charges. 
 economical point of view, if we except the 
 
 reduction in bulk of the matters that eventually require removal from the 
 house, which is only a matter of importance in the case of towns, and does 
 not apply with equal force to country houses. 
 
 The closet suitable for the earth system may be very similar to that 
 described under ash closets. A hopper of metal or wood is placed above 
 and behind the seat, and the requisite quantity of dry earth is shot into the pit 
 or pail by a simple mechanical contrivance connected with a handle (fig. 174) 
 or self-acting seat ar- 
 rangement. 
 
 In large establish- 
 ments the tank shown in 
 fig. 175 can be used. It 
 holds thirty- six charges, 
 ■ and being on wheels is 
 more easily removed 
 than a pail holding the 
 same amount. It is 
 especially useful for 
 schools, barracks, fac- 
 tories, &c., where the 
 closets are much used, 
 and where smaller pails 
 might in the course of 
 a day become overfilled. 
 The contents of the 
 pails must be kept dry, 
 or fermentation results 
 with the disengagement 
 of foul gases ; conse- 
 quently no slop waters must be thrown into them, and even chamber urine 
 must be excluded unless sufficient extra earth is added to render the contents 
 quite dry. 
 
 The compost produced by the passage of the earth even five or six times 
 through the closet has but little agricultural value as a manure. The 
 British Association Sewage Committee reported of such manure that it was 
 ' no richer than good garden mould.' The committee found that the average 
 gain of total nitrogen to the soil by each passage through the closet was 
 
 3g2 
 
 Fig. 174. — Earth closet, with pull-up handle apparatus. 
 
820 
 
 HYGIENE 
 
 scarcely O'lii per cent. ; and they remark upon this point that ' if only two 
 pounds of soil were used per head per day, and as much as one-third of the 
 total nitrogen voided in fieces and urine by an average individual in twenty- 
 four hours were collected with it in the closet, the nitrogen so added to the 
 soil would amount to about 0-5 per cent, of its weight by each use, or by 
 using five times to nearly 2-y per cent. Probably in practice a larger amount 
 of soil and a smaller proportion of the total nitrogen daily voided would be 
 collected in an earth closet. The increased percentage of nitrogen actually 
 found is seen to be less than one-third of the amount calculated on the 
 foregoing assumption. There can indeed be httle doubt that there is a 
 considerable evolution of nitrogen in some form ; and the probability is 
 that it takes place to a great extent as free nitrogen.' 
 
 This escape of nitrogen in a free state from the manure when kept may 
 partly account for its deficiency in fertilising properties ; but it must also 
 be recollected that the compost is largely diluted with valueless earth, and 
 that there is absent from it a large proportion of the daily urine of each 
 individual. 
 
 The late Dr. Voelcker estimated the value of the soil passed five times 
 through the closet at 75. Qd. per ton, and it is certain that it would only pay 
 
 the cost of carriage to a very short 
 distance, even if disposed of free of 
 charge. 
 
 Although the commercial value 
 of the earth-closet manure is so small, 
 it is found of considerable use in 
 gardens, whei'e it can be applied 
 ■v\dthout going to the expense of any 
 carriage. It forms a rich mould, 
 suitable for garden and pot plants, 
 and yet not so rich that it has to be 
 diluted with ordinary earth. In 
 country houses with gardens, there- 
 fore, the earth compost has a con- 
 siderable practical value. 
 From a sanitary point of view the earth closet is superior to any other 
 fonn of pail closet. When properly managed, the closet is free from any 
 offence ; the process of emptying the pails is unaccompanied by any foul 
 smells ; and the system is one which may be adopted in country houses and 
 villages, where earth of suitable quality is easily procurable, and where the 
 compost can be applied on the spot to fields or garden lands. It is, however, 
 especially applicable for temporary gatherings, such as fairs and camps. It 
 was, indeed, in use at the annual Volunteer meetings at Wimbledon for 
 some years, and answered very well. 
 
 Pig. 175. — Tauk liolding thirty-six charges. 
 
 Manufacture of Manure 
 
 We have already seen that the earth-closet manure requires no 
 further manipulation after removal from the closets, but can be applied 
 direct to land. It is somewhat difi"erent, however, with the crude contents 
 of middens and pails. In some towns situated in agricultural districts, 
 where there is a demand in the immediate locality for the coarser sorts of 
 manure, the contents of middens or pails need merely be mixed with a 
 certain portion of fine ash, when farmers in the neighbourhood are willing 
 to remove it. This manure is, however, only well suited for heavy clay 
 
THE DISPOSAL OF BE FUSE 821 
 
 soils ; for most soils the admixture with ashes renders it comparatively 
 •worthless. 
 
 In many of our large towns where the midden or pail systems are still 
 in vogue, it has become the practice of recent years to convert the crude pail 
 •or midden contents (without admixture with ashes) into a dry manure of a 
 much less offensive character, which can be packed in bags or casks, and sold 
 at a distance. 
 
 The following account of the process, as usually carried out, is taken 
 from a report (1881) of Dr. W. Sedgwick Saunders upon ' Some new Methods 
 of Disposing of all Kinds of Eefuse by Cremation.' 
 
 The ashes, &c., collected in tubs are screened in an automatic cinder 
 screen ; the fine ash is mixed with such portion of pail contents as will 
 furnish a manure sufficient to satisfy the local demand ; the coarse ash is 
 discharged into a form of furnace called a ' destructor,' which is made to 
 destroy and reduce any refuse material that contains only a small portion of 
 combustible matter. The heat generated by the combustion passes under 
 and through a multitubular boiler, and generates steam for furnishing the 
 power required for working the whole of the machinery. The clinkers from 
 the destructor, if not required for other purposes, are passed into a mortar 
 mill, which reduces them to powder that can either be sold as sand or made, 
 by the addition of lime, into an excellent and tenacious mortar. 
 
 The sweepings from the markets and streets are passed through a ' car- 
 boniser,' a furnace which converts all vegetable material into charcoal. The 
 charcoal produced is a powerful deodorant ; and it was proposed to use a 
 portion of it in each pail, previous to its leaving the depot, to deodorise the 
 matter collected, the remainder to be sold. 
 
 The contents of the pails are mixed with a small portion of acid, to fix the 
 ammonia, in an air-tight store tank, where the thicker portion of the material 
 settles to the bottom. The thin part of the contents of the tank is drawn 
 off into two evaporators, which are tall cast-iron cylinders, each containing, 
 near its lower end, a drum-shaped heater, precisely resembling a multi- 
 tubular steam boiler. These cylinders are partially filled, and the heating 
 drums are covered with the thin liquid ; steam is then introduced within the 
 heating drums, and the liquid becomes partially concentrated. When the 
 contents of these cylinders are sufficiently concentrated, and have lost, by 
 evaporation, the greater portion of their water, they are drawn off into a 
 ' Firman's dryer,' and the thick portions of the pail contents which settle in 
 the store tank are also admitted into the dryer. This machine consists of a 
 steam -jacketed horizontal cylinder, traversed by a steam -heated axis and by 
 steam-heated revolving arms, and is furnished with scrapers to keep the 
 inner surface of the cylinder free from accumulations of dried excreta. 
 
 The pail contents are admitted into the dryer at the consistency of thin 
 mud ; after treatment they emerge as a dry powder, resembling guano in 
 appearance and quality, and estimated by analysis to be worth from 31. 
 to 61. per ton. The odorous gases given off during the process are all 
 passed through the Destructor furnace and destroyed. From the time 
 the liquid material enters the store tank, until it finally emerges as a 
 dry powder, there is no opportunity for odour to escape into the air, as it is 
 kept closely under cover. 
 
 The destructor and the carboniser are the inventions of Mr. Alfred Fryer, 
 ■who also originated the system by which the collected ashes and cinders 
 are alone sufficient to furnish the heat necessary to evaporate the pail 
 •contents. 
 
 At Manchester a portion of the town refuse is dealt with in this manner 
 
822 HYGIENE 
 
 at the Corporation's sanitary works at Holt Town. The cinders collected 
 are mainly used as fuel for the furnaces of the boilers which work the- 
 machinery, effect the evaporations, etc.; the animal matters are converted 
 uito dry manure, soap, and lubricating grease ; and the clinkers fi'om the 
 fui-nace are made into mortar, bricks, and concrete. The animal matters 
 from which the manure is made include human excreta (pail contents),, 
 slaughter-house refuse, bones, dead animals, fish, &c. This manure con- 
 tains 2-73 per cent, of ammonia, 2-3G per cent, of phosphoric acid, and 15 
 per cent, of moisture. It is sold at 3/. per ton. 
 
 Systems similar to the above are now in operation at Cilasgow, Leeds, 
 Bradford, Warrington, Rochdale, Stafford, Bolton, Birmingham, Blackburn, 
 Rotherham, Derby, Bury, and Nottingham. 
 
 The deputation from the Commissioners of Sewers of the City of London 
 which visited the works established at Leeds, Bradford, Warrington, and 
 Manchester in 1881, came to the unanimous conclusion that the system is- 
 sound in theory and desirable in practice, and that it offered enormous 
 advantages upon sanitary grounds. ' Not only did they see a work consist- 
 ing of poisonous and disgusting elements dealt with, and satisfactorily dis- 
 posed of, without nuisance of any kind, but learnt that products having a 
 marketable value can be, and are, produced without any infraction of true 
 hygienic principles, whilst at the same time they may have the effect of 
 materially reducing the expenses ' (Dr. Saunders' Report). 
 
 Cesspools 
 
 Until lately the terms ' midden pit ' and ' cesspool ' were regarded as 
 synonymous. But it has now become more usually the practice to apply 
 the term ' cesspool ' to those receptacles excavated in the soil which are 
 destined to receive the Hquid waste waters of the house as well as the 
 excreta, whilst the ' midden ' is the pit for the reception of excrement only, or 
 of excrement and solid rubbish, the waste waters being got rid of by other 
 means. Under the primitive conditions which existed in nearly all towns 
 until within the last forty or fifty years, the waste waters of the houses in 
 the poorer streets (the slops and kitchen waters) were thrown into the street 
 gutters, which carried them away to the nearest watercourse. In more 
 recent times, since the introduction of drains and sewers, the house waste 
 waters of the midden towns are now conveyed to the sewers by slop sinks 
 and gully holes connected with a drain. The midden pits still remain for 
 the reception of the more or less solid refuse of the house. 
 
 It is therefore obvious that, whereas the contents of middens are, or 
 should be, in a more or less solid condition, the contents of cesspools must 
 necessarily be in a liquid condition, the volume of the liquids they receive 
 preponderating so immensely over that of the solids. 
 
 Prior to the year 1815, when the law which prohibited the passage of 
 sewage from houses into the sewers was repealed, in London and other large 
 towns nearly every house in the wealthier streets had one or more cesspools 
 on its premises for the reception of solid and liquid excreta and waste waters. 
 These cesspools were often of large size, and situated under the basements 
 of the houses. When, in the year 1847, it became compulsory to drain 
 houses mto the sewers, many of these cesspools were filled in and abolished ; 
 but some of them escaped observation, and to the present day it is no 
 imusual thing to find in the basements of town houses one or more cesspools,, 
 of the existence of which the owners or occupiers are profoundly ignorant. 
 
 At the present day cesspools are still largely in use, and fresh ones are 
 
THE DISPOSAL OF BEFUSE 823 
 
 being constantly constructed for isolated houses in suburban and country 
 districts where there are no sewers. In these houses, inside water-closets 
 are insisted on by tenants of the better class, so that the cesspools, which are 
 excavated in the yard or garden adjoining the house, become the receptacles 
 for the water-closet sewage and for waste waters of the house. 
 
 The desirability or otherwise of cesspools depends greatly upon circum- 
 stances. For country houses with large gardens the cesspool system offers 
 some advantages. If a series of two or three cesspools are constructed 
 communicating with each other by overflow pipes, most of the solids are 
 retained in the first of the series which receives the house drain. The over- 
 flow cesspools receive the liquid sewage, which can from time to time, as 
 desired, be pumped up and used as liquid manure for kitchen gardens, orchards, 
 &c. The solids very gradually accumulate in the first cesspool, from which, 
 when full, they can be extracted by buckets and dug into the ground. All the 
 cesspools should of course be constructed so as to be impermeable to fluids, 
 and even then should be at a considerable distance from any well ; and in no 
 case should they be provided with an overflow pipe to carry surplus sewage 
 into a stream supplying drinking water. Perhaps a better plan is to inter- 
 cept the solids in the sewage before it arrives at the cesspool by placing a 
 strainer in a manhole chamber on the drain. The most offensive matter 
 is thus entirely kept out of the cesspool, and can be dug into the ground 
 as soon as collected, the collection taking place daily. 
 
 Where, however, houses are more closely crowded together, and the plot 
 of land attached to each is of size insufficient to utilise the sewage by its 
 application to the soil, the cesspool system is liable to become an unmiti- 
 gated nuisance. The periodical visitations of the night-soil carts become 
 then a necessity. If in a sufficiently liquid state, the cesspool contents are 
 pumped up by manual labour into troughs and so conveyed to the carts, or, if 
 too solid for pumping, the contents must be drawn up in buckets. In either 
 case the pollution of the air is nauseating and disgusting to a degree, and the 
 offensive odours are wafted by the wind to considerable distances, so that all 
 the inhabitants of the neighbourhood become aware of what is in progress. 
 
 There are also other very distinct dangers attached to the cesspool 
 system. Cesspools are very frequently so constructed as to allow all the 
 liquid filth to percolate through their walls into the surrounding soil, the 
 solids only being retained. In unlined cesspools dug in porous soils, such 
 as sand, gravel, and chalk, the liquids escape with the greatest readiness, and 
 the cesspool but very rarely requires emptying. This is an advantage, how- 
 ever, which is far more than counterbalanced by the contamination of the 
 subsoil in the close vicinity of houses, and by the almost certain danger of 
 polluting . wells, springs, and other sources of underground water supply. 
 Such pollution is especially likely to occur in the case of cesspools dug in the 
 chalk. The liquids rapidly drain away through the cracks and fissures in 
 the chalk walls, and even the solids disappear, with the result of polluting 
 the water below in the subterranean reservoirs — a water which is naturally 
 of very great purity. In the case of sand and gravel, a cesspool is exceed- 
 ingly likely to contaminate the surface wells in the neighbourhood. 
 
 The model bye -laws of the Local Government Board for new buildings 
 require that the cesspool shou.ld be at least 50 ft. away from a dwelling, and 
 60 to 80 ft. distant from a well, spring, or stream. It must have no com- 
 munication with a drain or sewer in sewered districts ; its walls and floor 
 must be constructed of good brickwork in cement, rendered inside with 
 cement, and with a backing of at least 9 inches of well puddled clay around 
 and beneath the brickwork. The top of the cesspool should be arched over, 
 and means of ventilation provided. 
 
821 HYGIENE 
 
 The object of these rules is to secure an impenuoable receptacle for the 
 reception of the sewage, which will prevent pollution of the subsoil and of 
 underground water supplies. The reasons for not connecting a cesspool 
 with a sewer by means of an overflow pipe have already been alluded to 
 (see p. 813). 
 
 Constructed in accordance with these rules, the possible dangers of cess- 
 pools are reduced to a minimum ; but the principle, which is bad, remains 
 the same, for it cannot be too strongly insisted on that in the vicinity of 
 houses to retain in any receptacle, however well constructed, a large collec- 
 tion of solid and hquid excrement, there to undergo putrefaction with the 
 formation of ofiensive gases, is a violation of every sound sanitary principle. 
 
 COXTINENTAL SYSTEMS 
 
 In many Continental towns the cesspool system is still largely adhered 
 to. Huge pits [fosses iKrmancntcs) are excavated under the courtyards of 
 the houses, and are lined with cement, so as to be impervious. In Paris and 
 some other towns these cesspools must be provided with a ventilating shaft 
 reaching up some feet above the roof of the house. Sometimes two recep- 
 tacles are constructed side by side, and communicating with each other by 
 means of small apertures through which liquids only can pass. By this 
 means the solids are retained in one receptacle, whilst the liquids pass into 
 the other ; and this separation is fomid to materially retard decomposition. 
 Each of the receptacles is provided with a ventilating pipe. 
 
 The closets are usually connected directly with the cesspool by means of 
 the soil-pipe, starting from the soil-pan, when there is one, or from the hole 
 in the lead or zinc-lined floor of the closet, when there is not. There is often 
 no sort of trap at either extremity of the soil-pipe, so that the putrid gases 
 formed in the cesspool rise up into the interior of the house. The soil-pan 
 and pipe are usually only flushed Avhen slops are thrown down. 
 
 As a general rule, the cesspools are constructed of such a size that they 
 only require to be emptied once in three or four months. As a matter of 
 fact, being but rarely impervious, they allow some of their liquid contents to 
 escape mto the surrounding soil, and so only require emptying at even longer 
 intervals. 
 
 Until recently the cesspools were emptied by pumping their contents 
 through hose into large cask-shaped carts {tonneaux) sent for the purpose at 
 night when required. The nuisance engendered by this process has now 
 caused it to be largely superseded in Paris, Eheims, Metz, and other Conti- 
 nental towns, by a method of emptying the cesspools by pneumatic pressure. 
 
 One of these methods which is coming largely into use is that designed 
 by Talard. A steam vacuum pump is attached to a small portable locomotive 
 engine, to exhaust the air from the receiver or tonneau. These receivers are 
 barrel-shaped, of a capacity of about 3^ cubic yards, and are made of light 
 steel plates. Each receiver is mounted on framework on four wheels, and 
 can be easily drawn from place to place by a pair of horses. It is fitted with 
 a glass gauge at one side to show how full it is, and has a large full-way 
 valve underneath, to which a strong flexible 5-inch tube is attached. 
 
 On the cesspool being opened this tube is plunged to the bottom of the 
 contents, its other end being connected with the receiver, which has itself 
 already been connected with the engine by a smaller tube from its upper 
 part. The engine being started, the noxious gases are first extracted from 
 the cesspool, passed through the furnace and burnt ; the air is then exhausted 
 from the receiver, and on the valve being opened the contents of the cesspool 
 
THE DISPOSAL OF REFUSE 825 
 
 rusli up, filling the vacuum in about three or four minutes. The valve is 
 then closed, the pipes disconnected, and the receiver taken away to be re- 
 placed by others, until the cesspool is entirely empty. It is stated that by 
 this process the contents of a cesspool can be extracted at the rate of about 
 twenty cubic yards per hour. 
 
 The receivers can either be discharged into close barges, specially con- 
 structed for the purpose, in which case the pipe is connected at one end to 
 the receiver and at the other to the barge, so that the contents are transferred 
 from one receptacle to the other by gravitation, without being exposed to 
 the air ; or they can be emptied on to the land in the usual manner for 
 fertilising purposes. 
 
 The special feature of Talard's system as distinguished from other pneu- 
 matic processes is the invention of a mechanical joint to connect the lengths 
 of hose. This joint is both water- and air-tight, and can be made in two or 
 three seconds by an ordinary labourer, and as easily disconnected. 
 
 There can be little doubt but that the pneumatic system has most 
 materially diminished the nuisance formerly inseparable from the process of 
 emptying. Not only was it obnoxious to all in the neighbourhood, but the 
 foul gases generated by the disturbance of the contents of the cesspool were 
 a distinct danger to the workmen. Asphyxial poisoning {le pLomh des 
 vidangeurs) from great excess of sulphuretted hydrogen and corresponding 
 diminution of oxygen was occasionally the result of their operations, more 
 especially where the contents had to be raised in buckets to the surface ; 
 and the Paris scavengers were described by Parent Duchatelet as suffering 
 much from headaches and ophthalmia, which latter {la mitte des vidangeurs) 
 is generally attributed to the large amount of ammoniacal compounds present 
 in the foul air. 
 
 Movable tubs or pails {fosses mobiles) are also in use in some Continental 
 towns. As a rule, the tub or tonneau, capable of holding fifty or sixty gallons of 
 liquid, is placed in the basement, and is connected with the closets above by 
 means of an iron or stoneware soil-pipe. The tub is fitted with a spring lid, 
 which is adjusted when the tub is full, before its removal by the scavengers. 
 As with the fosses permanentes, there are, as a rule, no traps or valves fixed 
 anywhere to prevent foul gases rising into the house. Eeliance is placed 
 upon a ventilation pipe which is connected with the soil-pipe, and carried up 
 to the roof, and upon the lid to the closet, which, being constructed with a 
 rim fitting into a groove in the soil pan, is supposed to be air-tight. As a 
 matter of fact, however, foul gases find an easy exit into the house when the 
 closet is in use and the lid is raised. In some cases the fosses mobiles are 
 provided with separators for the separation of the liquids from the solids, 
 and it is then usual to carry the liquid contents into a cesspool. 
 
 In Paris the contents of the fosses permanentes and fosses mobiles are 
 converted into manure (;poudrette) by a process which would hardly be tole- 
 rated in this country. The tonneaux are carried away to the works outside 
 the town, where they are emptied into the highest of a series of basins 
 ranged one above another. Here they are exposed to the air for some time, 
 and while the liquid parts run away into the lower basins, the undissolved 
 solids subside in the higher ones. The liquids are reduced in quantity by 
 spontaneous evaporation, but they have for the most part to be pumped 
 away, generally into the nearest watercourse. The solid part which subsides 
 is dug out of the pits, further dried by being spread out on a large surface 
 of ground, and stirred about continually, piled up when nearly dry in im- 
 mense heaps, and left for a year at least — often for several years. It is then 
 sold under the name of pondrette. It has the aspect of a greyish-black 
 
82G HYGIENE 
 
 earth, light, oily to the touch, very pliable, and spreading a peculiar, dis- 
 agreeable, and nauseous odour. 
 
 It will be readily understood that this process of spontaneous evaporation 
 of moisture from immense heaps of putrid refuse must spread the effluvia 
 for miles around, and cause a nuisance, compared with which the worst 
 mana<^ed of our sewage works would be described as inoffensive. 
 
 COMPARISON OF CONSERVANCY :\IETHODS 
 
 From what -has already been written on this subject it will be apparent 
 that the best system from a sanitary point of view is that which provides tlie 
 most perfect means for preventing the decomposition of the excretal matters 
 during their period of retention on the house premises, and secures their 
 removal with the greatest frequency and with the least offence. 
 
 The midden system, even with middens constructed on the best approved 
 plan, stands condemned by reason of the nuisance engendered when their 
 contents are removed. The same remark appUes.with even stronger force to 
 cesspools, especially in towns. 
 
 "We are therefore entitled to insist upon some form of movable receptacle 
 in which excretal matters may be collected and removed, and practical ex- 
 perience and theory alike point to the pail system as the conservancy system 
 which is best suited for use in towns. 
 
 Where pails are in use the removal may be carried out twice or three 
 times a week ; there is no necessity for the pail contents to be disturbed until 
 they arrive at the depot, and consequently nuisance in the neighbourhood of 
 houses is, to a considerable extent, avoided, if the removal is sufficiently 
 frequent. There is, besides, another advantage which movable pails have 
 over fixed receptacles. Where compulsory notification of infectious disease 
 is in force, the local authority receive early information of cases of enteric 
 fever. The pails removed from infected houses can be marked, their contents 
 disinfected, and clean pails containing strong chemical solutions supphed in 
 their place. In this manner it will be possible to destroy much of the poison 
 excreted by a case of enteric fever, and very materially to place a limit on its 
 spread. 
 
 We have already seen that to keep the pail contents in a dry and inoffen- 
 sive condition some desiccating material must be added, but that to convert 
 the pail contents into a profitable manure they ought to be collected unmixed 
 with other substances. The great difficulty in getting rid of the crude pail 
 contents when mixed with ashes has induced numerous towns to essay the 
 manufacture of manure ; but we are strongly of opinion that that system 
 which gives the best sanitary results is likely in the long run to prove the 
 cheapest, and that admixture with ashes is one of the best methods to secure 
 this end. 
 
 It must be obvious that in towns ashes are the only deodorants Avhich are 
 in any way practicable. They are part of the domestic refuse of every house, 
 and would have to be removed in any case, and their preparation by sifting 
 involves but very little trouble, even if cinder-silting ash closets are not in 
 use. The quantity of dried and sifted earth that AS'ould have to be brought 
 into a town, were earth closets in general use, would be enormous. Then, 
 in every house accommodation must be provided for storing the earth and for 
 keeping it dry, and if the earth is to be used more than once the compost 
 must be stored on the premises and be again dried before use. The quantity 
 of matter to be removed from the houses by the local authority would be 
 
THE DISPOSAL OF BE FUSE 827 
 
 far in excess of that of the pail and ashes system, and when collected its 
 value for fertilising purposes is so low that there would be even a difficulty 
 of disposing of it if given away, for it would not pay to remove it. 
 
 Although, then, in towns where a conservancy system is unavoidable 
 ash closets appear to best meet the requirements, it must not be forgotten 
 that the success of this system depends largely on individual care on the 
 part of the householder, upon active sanitary inspection by the local authority, 
 and upon a well-organised scheme of scavenging — in fact, upon arrangements 
 of considerable complexity, which are liable to failure at unexpected times 
 and from unexpected causes. The expenses of this form of scavenging are 
 very high, and the more frequently the pails are removed the greater is the 
 cost, so that there is always an inducement to economise at the expense of 
 health. The pail system can be made to depart most from the principle of 
 the conservancy method, i.e. the retention of oxcretal matters on the premises 
 of houses, by adopting a plan of very frequent removals, but practically the 
 excessive cost of such a plan is found to be prohibitory. 
 
 The other great objection to all conservancy systems is the fact that they 
 only deal with a fraction of the waste matters of a community, and fail to 
 deal with a liquid refuse of a highly polluting character, a liquid which 
 causes the sewage of the so-called midden towns to be little, if any, less impure 
 than that of water-closet towns ; and so conservancy entirely fails to provide 
 any sort of solution to the question of disposal of sewage. 
 
 Neither can it be denied that dry closets of all kinds are not regarded 
 with favour when placed inside houses. To most people the retention of 
 excrement in any form within the house is objectionable, and this view of the 
 matter cannot be regarded as a mere prejudice. We are not yet in a position 
 to assert in any way positively that excreta, even if fairly deodorised by dry 
 earth or ashes, are under all circumstances innocuous. And, besides, there 
 is always the possible danger of slops being carelessly thrown into the dry 
 closet, when but a short time would be required to convert what was before 
 fairly tolerable into a most intolerable nuisance. On the whole, then, we 
 must conclude that dry closets are not applicable within houses, and that they 
 should invariably be placed outside the house in such a position that a free 
 current of air can always traverse the space between them and the house. 
 
 THE WATEE-CAEEIAGE SYSTEM 
 
 By this system is meant that all the human excretal matters of the com- 
 munity — solid as well as liquid — are, together with the waste waters, con- 
 veyed away from the houses in drains, and from the town in sewers. The 
 force which conveys them is gravitation, and this is enabled to exert its 
 power by reason of the liquid condition of the sewage. The solids of the 
 sewage, whether solid excreta or solid waste particles contained in the house 
 waters, are so insignificant in volume in comparison with the liquids that 
 they are carried along with ease in the flowing current. No additional 
 water is required to enable the liquid wastes of the house to carry with them 
 the solid excreta ; but in order to render the passage of the latter, when 
 deposited in water-closets, as quick and perfect as possible, and also to ensure 
 cleanliness of the water-closet apparatus, soil pipes, and drains, water is used 
 to flush these receptacles and to carry the excrement rapidly away down 
 the soil drains into the street sewer. 
 
 By this system, therefore, there need be no retention of excretal matters 
 on the house premises. Its leading principle is to convey them away front 
 
828 HYGIENE 
 
 the house, and subsequently from the town, as quickly as flowing water will 
 do it. This is the great contrast between the water-carriage and all conser- 
 vancy systems ; but, besides this, it is evident that the force employed in 
 water carriage, viz. gravitation, costs nothing, whereas the manual operations 
 of scavenging removal in the conservancy systems are very costly. 
 
 We have already seen that every town must have a system of sewers for 
 conveyuig away the waste waters from the houses and streets, and that these 
 waste w^aters are of very nearly as objectionable and polluting a character as 
 if they contained the solid human excreta. It therefore follows that what- 
 ever precautions are necessary to be taken in the construction and main- 
 tenance of the sewers of water-closeted towns, and whatever means require 
 to be adopted for the purification of the sewage of the latter before discharge, 
 apply with nearly equal force to the case of the midden towns, whose sewage 
 is to a great extent free from the solid faeces. 
 
 Neither need there be any question of increasing the capacity of the sewers 
 of a midden town which has adopted water-closets. 
 
 Sewers, as originally laid, Avere intended principally to carry off the rain 
 and surface waters from roofs, yards, and streets, and their size was entirely 
 regulated by the volume of these waters which they might be called upon to 
 receive at any time, such as during heavy storms of rain. The sudden rush 
 of water into the sewers during and after a heavy shower far exceeds in 
 volume the maximum daily flow of foul water from the houses with which 
 they are connected. And even were it not so, the entire excreta of a town 
 population, in comparison with the waste water of the population, is only, by 
 volume, as about one to a hundred ; whilst the additional water required for 
 flushing water-closets and sewers — though varying with the state of the 
 latter and the habits of the people — could not, in comparison with the total 
 volume of sew^age, be called large. 
 
 The water-carriage system, then, in the simplest way possible renders 
 unnecessary the difficulties and dangers which are inherent to the conservancy 
 systems, and its adoption in towns only demands the greater perfection of 
 sanitary works (sewers and drains) which are already necessary, and in most 
 cases already exist. 
 
 Water carriage is, of course, not possible under all circumstances ; towns 
 which have a very inadequate water supply may not be able to aft'ord the 
 increased amount of water required to flush water-closets, drains, and sewers, 
 and keep them in good condition. Or, again, towns standing at a very low 
 level may be unable to secure the gradients required to lay a system of 
 gra\itating sewers to a possible or desirable outfall. In this latter case, 
 however, the erection of pumping machinery actuated by steam or compressed 
 air is usually capable of solving the problem. 
 
 SEWEKS 
 
 As before stated, sewers in this country were originally designed to carry 
 ofl:" rainfall and surface waters. At a somewhat later period the drains from 
 houses were connected with them, so that they received in addition the house 
 waste waters ; and in some cases the overflow-pipes from midden pits and 
 cesspools were also carried into them, by wliicli means they received an 
 accession of foul and putrid liquids, often mingled with ashes, which tended 
 to choke them with sediment of a most offensive character. Still more 
 recently in many towais these sewers have also become the receptacles for 
 the water-closet sewage of numerous houses. This subsequent usage not 
 
THE DISPOSAL OF BE FUSE 
 
 829 
 
 being in any way warranted by their original design, wliicli was to carry 
 off water 2^ur et simple, it is not surprising that tlioy fail to perform the 
 functions now allotted to them, and are in many instances the sources 
 of nuisance and injury to health from causes which we shall presently 
 indicate. 
 
 As originally constructed in various towns in this country, the sewers 
 were laid at considerable depths below the surface, and were made of brick. 
 In shape they were rectangular (fig. 170), or with arched roof instead of flat 
 top, but some were circular or oval. At various points, catchpits from the 
 roadway delivered into tliern, and at convenient spots they discharged into a 
 stream, river, or ditch. Being constructed of porous bricks, they admitted 
 subsoil water, and thus had considerable effect in securing the drainage and 
 drying of the soil. No great stress was laid upon their having good gradients, 
 as they Avere only intended for rain water, and, being usually of considerable 
 size, there was no difficulty anticipated in removing by manual labour such 
 sediment as might collect in them. 
 
 Used in this manner as channels for water containing but few solids in 
 
 Pig. 176.^ — Brick square sewer with stone top. 
 
 suspension, these sewer drains acted fairly efficiently. Their effect in lowering 
 the level of the subsoil water and drying the ground beneath and around 
 houses was an especially important one. Those diseases which are associated 
 with dampness and moisture of the soil — ague, rheumatism, bronchitis, &c.— 
 have been considerably lessened by works of drainage ; but the great reduc- 
 tion in the death-rate from phthisis resulting from the subsoil drainage 
 of those towns which formerly were situated upon waterlogged or moisture- 
 laden soils, was a result as satisfactory as it was unlooked for. In some 
 towns where the sewerage works have caused a considerable fall in level of 
 the subsoil water, which formerly stood within a very few feet of the surface, 
 the deaths from phthisis have even been reduced by a third, and in one case 
 by a half, of what they had previously been. 
 
 The great disadvantages, however, attending pervious sewers soon became 
 realised when they became the recipients of the foul waters and excretal 
 refuse from houses. Wherever the gradients of the sewers were insufficient 
 for a proper flow, or where the invert of a portion of a sewer had sunk below 
 its original level, owing to faulty workmanship or want of a proper foundation, 
 the stagnant sewage deposited its suspended particles, and accumulations of 
 
830 HYGIENE 
 
 offensive sediment were the result. O^Ying to the porosity of the bricks much 
 of the water percolated through the walls of the sewers to pollute the sub- 
 soil water and contaminate the ground air ; and this escape of the water, by 
 withdrawing the vehicle in which the solids of the sewage ought to have 
 been suspended, tended to aggravate the deposit of the latter on the floor of 
 the sewer, and often resulted in its complete choking and obstruction. 
 Manual labour had to be employed to clear the sewers and remove from 
 them the accumulated deposits. Great expense was thereby incurred, and 
 the foul condition of the sewers was often a source of considerable danger to 
 the men engaged in this scavenging work. The foul gases, too, generated by 
 the putrid sediment and stagnant pools of sewage, escaped through the street 
 ventilators — if there were any — or else found their way into houses through 
 drain connections and trapped or untrapped openings. 
 
 The pollution of the subsoil with the foul liquids that percolated through 
 the walls of the sewers resulted in contamination of the water in neighbouring 
 wells, and in some cases the water supply of an entire community has been 
 endangered by the entrance of such foul matters into the water mains during 
 intermissions in the service. 
 
 In some towns the old drain-sewers still perform the double function of 
 draining the subsoil and conveying away the surface waters and sewage. In 
 these places the evils described as inseparable from defective sewers are 
 always present in a greater or lesser degree. Foul sewer emanations into 
 the streets and houses, polluted wells, and contaminated ground air, exercise 
 a pernicious influence on the health of the inhabitants, and such diseases 
 as enteric fever, diarrhoea, and diphtheria tend to become endemic and to 
 exhibit epidemic outbursts during favourable seasons. 
 
 In many towns, however, in this country the old defective drain-sewers 
 have been largely reconstructed of proper materials and of proper size, 
 shape, and fall, but still receive as before both storm waters and sewage on 
 what is known as the combined system {tout d Vegout). In other towns, 
 again, new pipe sewers have been laid to receive the house waste waters and 
 water-closet sewage, whilst the old drain sewers still perform their original 
 functions as dryers of the subsoil and carriers of rain water. This has been 
 termed the separate system of sewerage, and was first prominently brought into 
 notice in this country by Mr. Menzies. It has since been adopted in the 
 United States by Colonel Waring. 
 
 The Combined System 
 
 In modern systems of sewerage the chief principles involved are (1) the con- 
 struction of sewers with impermeable materials, so as to prevent, or very 
 greatly limit, the percolation of polluting liquids through their walls mto the 
 surrounding soil ; (2) the rendering of the sewers self- cleansing by construct- 
 ing them with sufficient gradients, and of a size suitable to the volume of 
 seAvage which they will ordinarily be required to carry ; (3) the adoption of 
 effectual means for flushing and ventilating the sewers. 
 
 In the construction of brick sewers, well-burnt, tough, impervious bricks 
 should be used ; and for the lowest segment, or invert of the sewer, glazed 
 firebricks, or suitably curved stoneware blocks, are found advantageous. The 
 floor or invert of the sewer being the part most liable to wear and erosion 
 from the passage of the suspended matters in the sewage over it, it is highly 
 important that it should be constructed of very smooth, hard, and wear- 
 resisting material. The stoneware invert blocks are occasionally made hollow, 
 and they then provide a means of draining off" the subsoil water during the 
 
THE DISPOSAL OF BE B' USE 
 
 831 
 
 construction of the sewerage works ; but inasmuch as these hollow blocks often 
 lead to settlement of the sewer in sandy soils from sand being washed into 
 them and carried away, and as they are apt to split from the weight of the 
 sewer built over them, they are not now looked upon with favour by engineers. 
 Small sewers under 8 feet in diameter, when laid in good ground, may be 
 constructed of 4^-inch brickwork, but the bricks used should be curved to 
 suit the shape of the sewer when completed. Nine-inch brickwork should be 
 used for larger sewers, or for the small sewers when laid in bad ground or 
 shifting sand. The cement used in jointing the bricks should be a mixture 
 of clean sharp sand and best Portland cement in the proportion of two parts 
 of the former to one of the latter. Portland cement is a mixture of chalk 
 and clay burnt at a h-igh temperature, and subsequently ground very fine. 
 It is stronger and capable of 
 
 bearing greater tensile strains ^^-N^'V; 
 
 than other cements, but does 
 not set so rapidly. 
 
 Sewers with an internal 
 •diameter over 18 inches are 
 now usually constructed 
 oval or egg- sharped in sec- 
 tion, with the smaller end 
 •downwards (fig. 177). The 
 volume of sewage flowing 
 through a sewer necessarily 
 undergoes very great fluctua- 
 tions from day to day, and 
 even from hour to hour. 
 The advantage of the egg- 
 shape is that when the 
 volume of sewage is small, 
 there is a greater depth of 
 liquid and less contact with 
 the walls of the sewer, and 
 consequently less friction, 
 than in any other form. 
 The oval form is also of 
 superior strength to any 
 
 other form, as it offers greater resistance in every direction to external 
 pressure. There is also considerable economy in the construction of this 
 form. For outfall sewers, however, in which the volume of sewage to be 
 ■conveyed is large and fairly uniform, Mr. Baldwin Latham advocates the 
 •circular form, as being, for these larger sizes, cheaper to build and stronger 
 when constructed. 
 
 To render the sewers self-cleansing, and to prevent deposit of sediment on 
 their floors, they must be laid with a sufficient gradient, and must be con- 
 structed of a size suitable to the volume of sewage that they will orduiarily 
 be required to carry. Mr. Baldwin Latham advises that sewers of from 12 
 to 2'1 inches diameter should have a gradient sufficient to produce a velocity 
 of not less than 2^ feet per second, and in sewers of larger dimensions in no 
 ■case should the velocity be less than 2 feet per second. A less gradient 
 is required for large sewers than for small sewers to produce the same velocity, 
 but the volume of sewage to be conveyed by the larger sewer must far exceed 
 that to be conveyed by the smaller sewer. Mr. liatham gives the following 
 example in his work on sanitary engineering : — A sewer 10 feet in diameter 
 
 Fig. 177. — Section of egg-sliaped brick sewer. 
 
832 HYGIENE 
 
 Laving a fall of 2 feet per mile ; a sewer 5 feet in (liamcter having a fall of 
 4 feet per mile ; a sewer 2 feet in diameter having a fall of 10 feet per 
 mile, and a sewer a foot in diameter, with a fall of 20 feet per mile, will all 
 have the same velocity of How ; hut the volume of sewage in the 10-foot sewer 
 must be 100 times, in the 5-foot sewer twenty-five times, and in the 2-foot 
 sewer four times, the volume of sewage in the 1-foot sewer. 
 
 In practice, however, it is impossible to adjust the size of the sewers on 
 the combined system to the volume of sewage they arc ordinarily intended to 
 carry. They must be designed to receive a large portion of the rain falling- 
 over the sewered area of a town, as well as the sewage proper from the houses. 
 In most towns a large part of the surface exposed to rainfall consists of im- 
 permeable materials — slated or tiled roofs of buildings, paved yards, courts, 
 and streets — so that the fallen rain runs rapidly oft" the surface to the 
 gutters and street gullies ; and it has been estimated that on an average 
 from one-half to three-quarters of the rain falling reaches the sewers within 
 a very few hours, and even more, and in less time, where there are steep 
 gradients. 
 
 The sewers, then, have to be constructed of such dimensions as to 
 admit a sudden influx of storm waters in large amount ; and in ordinary 
 times of dry weather the volume of sewage conveyed — even the maximum 
 daily flow — may be insufiicient to carry along the suspended matters, and 
 a deposit of sediment occurs, Avliich has to be removed by flushing or hand 
 labour. 
 
 During heavy thunder showers in this country an inch of rain may 
 occasionally fall in the course of an hour or less. But it is not usual to 
 provide for such heavy storms, which are certainly very exceptional. The 
 usual provision, perhaps, takes account of a quarter of an inch of rain falling 
 in two or three hours. If the provision is insufiicient, unless storm-overflows 
 have been constructed, the sewers in low-lying districts become overcharged, 
 and cellars and basements in these low-lying houses are flooded. After a 
 period of drought a sudden hea^^ storm effectually flushes the sewers, the 
 accumulated sewage deposits are swept away in the rush of water, and finally 
 left behind as a putrid mud on the precincts of the flooded houses. In London 
 the intercepting sewers were designed to receive a quarter of an inch of rain 
 over the whole sewered area of the metropolis in twenty-four hours, and this 
 in addition to the subsoil water ordinarily finding its way into the sewers ; 
 but numerous storm-overflows have been constructed, at great cost, direct 
 into the Thames above London Bridge, and these relieve the overcharged 
 sewers during heavy rain, except when their outfalls into the river are tide- 
 locked by a high state of the tide. At such times low-lying districts of the 
 metropolis are liable to be flooded, as indeed happened to parts of the East 
 End of London after the tremendous rainfalls of July, 1888. It is certain also 
 that the discharge of crude sewage into the Thames in the heart of London 
 by these storm-overflows is occasionally productive of considerable nuisance 
 to the river-side inhabitants. 
 
 The actual sizes of sewers under the combined system are very various in 
 different towns. In London, in many districts, pipe sewers have now been 
 laid in the smaller streets, the houses of which they connect with a brick 
 sewer in a main thoroughfare. The brick sewers of the smaller streets, 
 courts, and alleys vary in size from 3 ft. by 2 ft. 2 in. to 4 ft. by 2 ft. 2 in. In 
 the larger streets they are from 4 ft. G in. by 2 ft. in. to the size of the main 
 sewers, which are of considerably larger but varying dimensions. The three 
 northern outfall sewers are each 9 ft. by 9 ft., with vertical sides. The 
 southern outfall sewer is 11 ft. 6 in. in diameter. Most of the street sewers 
 
THE DISPOSAL OF BE FUSE 833 
 
 and all the mains are large enough for the sewer men to enter and traverse 
 when engaged in removing deposit, in repairing the sewers, or examining 
 house connections. 
 
 As previously stated, the large size of the main sewers is necessitated by 
 the immense volumes of storm water they are at times called upon to receive. 
 It has been calculated that a main sewer intended to receive all the sewage 
 of a thickly populated square quarter of a mile, with a water supply of twenty 
 gallons per head daily, and also the rainfall of the same surface, if equally 
 distributed over every day of the year, would only actually require for these 
 purposes a sectional area of 4 square feet, but that practically, in order to 
 provide for sudden storms, this size would have to be at least doubled. A 
 still larger sewer would be necessary for the same population if spread over 
 a larger area. 
 
 We have seen that the property possessed by the old pervious sewers of 
 draining the subsoil was a very important one in its bearing upon the public 
 health. Modern brick sewers, being constructed of more impervious materials, 
 necessarily act less efficiently as drains. But inasmuch as it is a matter of 
 great difficulty to make brick sewers quite impervious to water it follows — 
 and such has been proved by experience — that they do to a certain extent 
 admit subsoil water in porous soils, and the sewer trenches also serve as 
 channels for the passage of water alongside the sewers to escape at the sewer 
 outfalls. It is not therefore considered necessary, as a rule, to provide any 
 additional means of draining the soil when brick sewers are in course of con- 
 struction. Sometimes, however, where there is much subsoil water, a porous 
 pipe drain is laid under the sewer, to carry off water in the soil around it ; 
 but when this is done there is a possibility of settlement taking place from 
 sand being washed away in the drain. 
 
 In the most modern systems of sewerage the sewers are laid in straight 
 lines, and manholes (fig. 179) are built over the sewer at the points of change 
 of direction. The junctions of the smaller sewers with the larger ones are 
 made at an acute angle, so that the sewage enters the larger sewer from the 
 less in the direction of the flow of sewage in the former. The points of 
 junction, wherever possible, should be above the floor of the larger sewer to 
 prevent backing up of sewage in the smaller conduits, and consequent 
 obstruction to the flow in them. 
 
 To calculate the discharge from sewers the following formula is found 
 convenient : — 
 
 Let V = velocity of flow in feet per minute. 
 „ D = hydraulic mean depth. 
 ,, F = fall in feet per mile. 
 Then V = 55 (VD x 2F). 
 
 If A = sectional area or the current of fluid, V x A = discharge in cubic 
 feet per minute. 
 
 The hydraulic mean depth in sewers of any section is the sectional area 
 of the current of fluid divided by the wetted perimeter (that part of the 
 circumference of the sewer wetted by the fluid flowing through it) ; in circular 
 sewers it is constant and equal to one-fourth the diameter. 
 
 The Sepaeate System 
 
 In this system the house sewage is separated from rain and surface waters 
 and conveyed away in pipe sewers of small diameter. The pipes (fig. 178) 
 need be only of small size, for they are not liable to any sudden influx of 
 
 VOL. I. 3 H 
 
681 
 
 HYGIENE 
 
 storm water, and the daily volume of bouse sewage — even its hourly varia- 
 tions — can be calculated with some approach to accuracy from the water 
 supply and known habits of the population. In small towns the pipes usually 
 vary in size from in. to 15 in. in diameter, the smaller pipes receiving the 
 house sewage in the bye-streets, and the larger being collecting pipes con- 
 ducting the sewage to the outfall sewer. Some authorities advise that no 
 public street sewer should be less than 9 in. in diameter, owing to the risk of 
 smaller pipes becoming obstructed by articles improperly introduced into the 
 house drains ; but in actual practice we believe it to be very rare for such 
 stoppages to take place in pipes of G in. diameter. 
 
 Up to 18 in. internal diameter sewers should certainly be circular in 
 section ; and for these small sizes pipes of stoneware, cement, or concrete 
 are preferable to brick sewers. In this country glazed stoneware pipes are 
 most generally used for the sewers of the separate system ; but in Germany 
 cement and silicated concrete pipes have been extensively used. Mr. Baldwin 
 Latham describes these pipes as being less brittle, more capable of with- 
 standing extremes of climate, and of resisting the chemical action of the 
 
 sewage than stoneware pipes. They 
 are also said to improve materially 
 with age, and to be unaffected by the 
 jar and vibration of heavy traffic in 
 the streets overhead, which sometimes 
 causes stoneware pipes to split. Like 
 stoneware, pipes of cement or silicated 
 concrete are impermeable to water 
 when properly jointed. 
 
 As for house drains, so stoneware 
 pipes intended for sewers should be 
 laid on a firm bed of hard ground 
 or cement concrete at gradients suf- 
 ficient to give a velocity of flow of 
 2^ or 3 feet per second, according to 
 the diameter of the pipes. The socket 
 end of the pipe should be placed up- 
 wards and the joint between the spigot 
 end of the pipe above and the socket of the pipe below should be filled in with 
 the best Portland cement, especial care being taken to remove any cement 
 projecting from the interior of the joint into the pipe, which, when hardened, 
 would form an obstruction to the flow of sewage through it. The junctions 
 between pipe sewers should be made by means of properly curved junction 
 pipes ; and where one or more tributary sewers join a main sewer, a manhole 
 (fig. 179) should be built over the point of connection, with curved channels 
 in its floor for the connecting pipes. 
 
 When pipe sewers are laid in loose sandy soils it often happens that sub- 
 soil water gets into them, and issues from their mouths as soon as they are 
 laid, in consequence of the cement, even when covered with a clay lute, getting 
 washed into the sewers before it has time to set. If this happens the sewers 
 are not impermeable, and whilst subsoil water finds its way in, foul liquids 
 may percolate out into the surrounding soil. In these bad soils cast-iron 
 pipes may be laid with joints made with red lead, cement, and spun yarn, or 
 better with molten lead ; or in the case of stoneware pipes Brooke's subsoil 
 drain and pipe rest may be used. This subsoil drain and pipe rest has the 
 form of the letter Q ; it is laid in the bottom of the trench, like an ordinary 
 pipe sewer, and jointed with clay, and has the effect of lowering the subsoil 
 
 Fig. 178. — Pipe sewer in trench. 
 
THE DISPOSAL OF BE FUSE 
 
 835 
 
 ^ater, so that the sewer proper can be laid upon the movable saddles or rests, 
 undisturbed by water or running sand. By these means the cement joints 
 can be made perfect all round, and have time to set before the trench is filled 
 up. True gradients are ensured, as the pipes can be leisurely laid ; and as the 
 pipes are jointed over the middle of the subsoil drain a continuous foundation 
 is secured. A more perfect drainage of the subsoil is also found to result, 
 the general level of the water being reduced to nearly the level of the sewer 
 invert. 
 
 Fig. 179. — Manhole and ventilator. 
 
 The only sewers with the separate system which need be of brickwork 
 are the large mains and outfall in good-sized towns and the outfall sewer in 
 the smaller towns. 
 
 The pipe sewers receive the water-closet sewage and waste waters of 
 houses only. The rain water from the roofs and yards of houses must be 
 conveyed by separa,te pipes into surface channels at the sides of the streets, 
 when-,the gradients are sufficient, or into undergroimd channels constituting 
 a system of drains quite distinct from the sewers. In many towns the old 
 existing brick drains have been utihsed for the latter purpose, and they also 
 serve as subsoil drains. At convenient points the surface channels or under- 
 ground drains should discharge into the stream or river which constitutes 
 the natural drainage bed of the locality. 
 
 Where no brick drains exist there is little or no drainage of the subsoil, 
 as the pipe sewers are impermeable to water. In these cases agricultural 
 
 3h2 
 
836 HYGIENE 
 
 tile drains, 1 to 3 inches in diameter with open joints, should he laid in the 
 same trench but above the pipe sewers — which are embedded in clay puddle 
 (Baldwin Latham) — and surrounded with coarse gravel to allow the subsoil 
 water to permeate into them ; at suitable points these drain pipes may be 
 diverted into the watercourses. 
 
 The advantages of the separate system may be summed up as follows : — 
 (1) The whole volume of sewage to be conveyed away from the town is very 
 much less than that to be dealt with by the combined system. In an 
 instructive comparison of the town of Slough, which is sewered on the 
 separate system, with that of Romford, sewered on the combined system,. 
 Mr. R. F. Grantham has shown that the average amount of sewage pumped 
 in a year on to the Slough sewage farm was 30,000,000 gallons, whilst the 
 average amount of a year's sewage received at the Romford sewage farm was 
 over 100,000,000 gallons, Slough having a population of 5,200, with a water 
 supply of ten gallons per head daily, and Romford a population of 6,300, with 
 the same amount of water supply. 
 
 (2) The daily and seasonal fluctuations m the volumes of sewage 
 deUvered urfder the separate system are small, and the total quantities 
 to be dealt with can be approximately calculated from the population 
 and water supply, these being points of the greatest practical importance 
 where the sewage has to be pumped at the outfall or purified before being 
 discharged. The daily and weekly fluctuations under the combined system 
 may be enormous owing to the entry of rain and subsoil water into the sewers. 
 Thus at Romford, during a period of three years, the largest amount of 
 sewage received in the course of a week at the sewage farm was 3,G62,000 
 gallons, and the smallest amount representing the dry weather flow only 
 1,321,000 gallons — equal to about one-third of the greatest. 
 
 (3) On the other hand, on the separate system, the sewage of every twenty- 
 four hours is fairly uniform in composition, because it is protected from dilution 
 wdth storm waters, and its purification and utilisation are midertaken with 
 much less difficulty than ui the case of sewage varying in strength accord- 
 ing to the amount of rain and subsoil water mixed with it. 
 
 (4) The sewers, too, being of small size and having perfectly smooth 
 walls, are more often running full, and are therefore better flushed, with less- 
 tendency to deposit sediment resulting in the formation of foul gases, than 
 is the case with the large brick sewers, to whose walls foul matters so readily 
 adhere. 
 
 (5) Lastly, the cost of the system is very much less than that of the 
 combined system. Pipe sewers are more quickly laid than brick sewers can 
 be built ; they require a much smaller amount of excavation than brick 
 sewers, and they can be made with very various curves to suit different 
 positions. 
 
 The disadvantages of the separate system are, that every house must 
 be provided with tw^o drains, or two sets of pipes — one for sewage and the 
 other for rain water. This means a somewhat heavy initial outlay on the 
 part of houseowners, and it occasionally gives rise to mistakes on the part 
 of builders, who connect the pipes with the wrong system. The surface 
 water from yards and streets is also sometimes foul, especially when a storm 
 succeeds a period of drought, and this foul water may conceivably cause a 
 nuisance in the stream into which it is discharged. At Slough, however, no 
 complaint has ever been made about the surface-water drain, which discharges 
 into a ditch by the side of a public road within the statutory three miles 
 distance from the river Thames, and therefore within the jurisdiction of the 
 Thames Conservancy. It has been recommended that the surface water 
 
THE DISPOSAL OF BEFUSE 837 
 
 -from the back yards of houses should be discharged into the sewers, instead 
 of into the surface channels or subsoil drains, as these waters are often of a 
 somewhat polluting nature. But it would probably be better for the local 
 authorities to enforce proper scavenging and cleansing of the yards and 
 streets than to introduce storm waters into pipes of size possibly inadequate 
 for their reception. 
 
 Numerous towns in this country are now provided witli pipe sewers, and 
 the system is likely to be much more largely adopted in all eases where 
 circumstances are favourable to its execution. In America, the city of 
 Memphis has been sewered on the separate system, the plans of the works 
 being designed and carried into execution under the direction of Colonel 
 Waring. A very complete and interesting account of the system and its 
 working at Memphis will be found in the Second Annual Eeport of the 
 State Board of Health, New York, 1882. Pullman, near Chicago, is also 
 sewered on the same system, and numerous other towns in the States propose 
 to adopt similar works. 
 
 Flushing and Inspection op Sbwees 
 
 In the old badly constructed brick sewers, without sufficient incline, large 
 deposits of semi-solid filth took place, which were removed by hand labour 
 at great expense. In some cases the deposit was removed through manhole 
 
 ■ entrances to the sewers, but in others where it was 3 or even 4 ft. thick, and 
 had stopped up the sewer, not only had the street to be broken up, but the 
 arch of the sewer was also broken into, and the foul mud raised to the 
 surface and carted away, the whole process causing a very great nuisance to 
 the neighbourhood. The late Sir Joseph Bazalgette in his work on the 
 ■'Main Drainage of London ' has stated that the cost of removing deposits 
 from the tide-locked and stagnant sewers in London formerly amounted to 
 about 3O,000Z. per annum. 
 
 It soon, however, came to he understood that periodical flushing of the 
 sewers was able to accomplish this work of carrying away sediment in a far 
 more efficient and economical manner than removal by hand labour. By 
 heading up the sewage in a certain spot, by means of sluices or flushing 
 gates made to fit the greater part of the sectional area of the sewer, a force 
 sufficient to effectually flush and cleanse the sewer below for a considerable 
 
 ■ distance can be generated on raising or liberating the gate. 
 
 These flushing gates can be fixed at the sites of manholes, and can then 
 be manipulated by the sewer men, or self-acting gates can be used for the 
 same purpose. In this form the gate is fixed in the sewer by hinges 
 attached below its centre. The pressure of the sewage on that portion of 
 the gate which is below the hinge fixes it in position, and the sewage rises 
 until it reaches the upper portion of the gate. This presents a larger surface 
 to the dammed- up sewage than the lower portion of the gate below the 
 hinges, so that a point is at length reached when the gate tilts forwards, 
 assuming a horizontal position, and the sewage escapes with a velocity pro- 
 portional to its head. 
 
 These gates are of course inapplicable to the upper or dead ends of brick 
 sewers. Perhaps the best method of flushing these and the smaller tributary 
 sewers is to discharge the contents of a street watering cart suddenly into a 
 manhole or other opening into the sewer. 
 
 Sewers are most in need of flushing during the summer season and pro- 
 longed periods of dry weather. At these times, unless artificial flushing is 
 
838 HYGIENE 
 
 resorted to, tlie amount of water flowing throngli the sewers is insufiicient to 
 prevent the deposit of sediment. But the flushing should he periodical in 
 the older hrick sewers all the year roimd, for, although heavy rainfall is very 
 efl'ectual for flushing purposes, it cannot he depended upon in this climate to 
 occur at properly recurring intervals, and it introduces, hesides, a quantity of 
 sand and grit from the surfaces of the roads which tends to settle in de- 
 pressed portions of the floors of the sewers, and to form the nidus for further 
 deposits of sediment. 
 
 It is certainly advisable that arrangements should be made for flushing 
 the pipe sewers of the separate system, inasmuch as they do not experience 
 the cleansing eflect of storm waters, in all cases except where the gradients 
 are very good and the water allotted for closet-flushing purposes is ample.. 
 Perhaps the best method is that introduced by Colonel Waring in the case 
 of the pipe sewers at Memphis. At the dead end of every branch sewer is 
 placed an automatic siphon flush tank with a capacity of 112 gallons. The 
 tank consists of a brick chamber, built on a concrete bottom, set below the 
 level of the street and covered with a perforated lid ; in the centre of the tank 
 is an annular siphon (fig. 185, p. 888) which discharges into a box underneath 
 it, and thence into the sewer. The tanks are filled from the city water 
 supply, and discharge their contents with the most perfect regularity. The 
 rush of water from them is distinctly felt at a distance varying from 400 to- 
 900 ft., keeping the pipes perfectly clean. No tendency to freeze has been 
 noticed in the tanks, although the temperature of the air has been as low as 
 4° F. In all, there are 125 of these flush tanks at work in Memphis to flush 
 twenty miles of sewers. A slight deposit of silt has at times occurred in some 
 of the mains, but this has never been more than 1 or Ih mches in depth. 
 
 Means of access must be provided for brick sewers — for their examination, 
 for the execution of necessary repairs, and for iheir cleansing. For this 
 purpose manhole shafts (fig. 179) are sunk from the surface of the road to the 
 sewer by which the scavengers can descend. They are constructed of brick- 
 work and provided with a locked iron door at the street level. In streets 
 with much trafiic the shaft is sunk from the footway perpendicularly for 
 a sufiicient distance and then carried down by means of steps to the side of 
 the sewer. In unfrequented thoroughfares the manholes may be sunk from 
 the roadway direct to the crown of the sewer or immediately at its side. 
 The side entrances are not so cleanly as those opening into the crown of the 
 sewer, as in times of heavy rain the sewage may leave detritus on the steps 
 of the passage, which subsequently decomposes and gives rise to offensive ■ 
 effluvia. 
 
 The manholes have also other uses ; they serve as points of junction 
 between tributary sewers and the main sewers, and they are the points at 
 which flushing gates and ventilators may most advantageouly be fixed. 
 
 In the pipe system of sewerage manholes should be constructed on the 
 mains at convenient points, such as where a change of direction occurs 
 (fig. 179), At Memphis there is a manhole at a distance of every 500 ft. on 
 the mains. On the branch sewers T-pieces should be inserted at intervals, 
 with a lid on the top of the upright stem at the street level, which can 
 readily be removed, and a cleaning tool introduced to clear away the obstruc- 
 tions which are occasionally produced by the introduction of improper 
 articles into the house drains. At Memphis several 2-foot carpenters' rules, 
 folded to G inches, which had passed through the 4-inch traps on the house- 
 drains, have been removed from the G-inch pipe sewers after causing an 
 obstruction to the flow of sewage through them. 
 
THE DISPOSAL OF BE FUSE 839 
 
 Ventilation op Seweks 
 
 Considerations arising from the facts elicited by modern research into the 
 causation and propagation of infectious diseases have imparted an importance 
 and significance to the subject of sewer ventilation which was absent in 
 times but recently passed. To know that the infective agents of such diseases 
 as cholera, typhoid fever, many cases of diarrhoja, and probably other 
 diseases, are passed out of the body in the excretions of the patients suffering 
 from them, that they probably have the power of self-multiplication outside 
 the body in sewers and sewer deposits, and can infect the air in contact with 
 them, is to understand the importance which sewer ventilation has on the 
 public health, and to impress the necessity for the closest attention to this 
 subject on the part of those who are entrusted with local sanitary adminis- 
 tration. 
 
 In the first place, we see that town sewers are underground channels, 
 which place houses both near and remote from one another in more or less 
 direct aerial connection in all cases except where the house drains are 
 disconnected from the sewer by a water trap and an opening to the external 
 air on the house side of the trap. Between houses where this form of dis- 
 connection is not practised, not only is there the aerial connection, but rats 
 and other vermin may be the means of carrying infected filth from a fever- 
 stricken house to a healthy one. This latter mode of conveying contagion 
 has, however, been more fully treated of in the chapter on house drainage, 
 and does not require consideration here. It is sufficient for us here to know 
 that the poisonous agents of disease excreted in one house may be wafted in 
 the air of the sewers into the drainage pipes of another house in its neigh- 
 bourhood, or even remote from it. To counteract this mode of propagation, 
 of disease, two precautions are essential. The first is to prevent by means of 
 water-traps and a proper system of house-drain ventilation any entrance 
 of drain or sewer air into houses ; the second is the adoption by local 
 authorities of some means whereby an abundance of fresh air can be mtro- 
 duced into the sewers, and the mixed air and gases can escape from the 
 sewers at points as remote as possible from inhabited dwellings. As in 
 house drains, so in sewers, a constant current of fresh air should be flowino- 
 through them to dilute the offensive gases and render less dangerous the 
 disease poisons which may possibly be present, and this current very effec- 
 tually aids the escape of the sewer air at the proper points of exit. 
 
 It is now generally believed that the bowel discharges in cases of typhoid 
 fever and allied diseases may impart their infective qualities to large volumes 
 of sewage, and to the deposits and slime which are so frequently found on 
 the floors and walls of sewers. The microbes of such diseases find a suit- 
 able soil for growth and multiplication in sewage and sewer deposits, which, 
 it must be remembered, are always considerably warmer than the outer 
 atmosphere during the winter months, and contain organic matters of both 
 animal and vegetable origin, phosphates, nitrates, and ammonia, all affording 
 food for the growth of micro-organisms. There is plenty of evidence to 
 show that the percolation of infected sewage out of sewers into wells and 
 water mains has produced epidemic outbursts of fever ; and there can be 
 but little doubt that the sewer air in contact with such infected materials 
 also becomes imbued with specifically contagious properties. For enteric 
 fever has undoubtedly been caused by inhalation of sewer air, no other means 
 being ascertainable by which the infected persons could have been brought 
 into contact with contagion ; and there are the records of specific contami- 
 nation of drinking water in cisterns and mains by such air. 
 
810 HYGIENE 
 
 Amongst other diseases of which proof has been adduced that they are 
 occasionally the result of sewer-air pollution may be mentioned a severe 
 form of acute tonsillitis (sewer-air throat), diphtheria, and the hospital 
 fevers — surgical fever, erysipelas, pyaemia, septici^mia, and puerperal fever. 
 Years ago these diseases were very constantly present in the wards of 
 general and lying-in hospitals ; but since measures have been taken to 
 improve the drainage of these institutions and prevent any possibility of 
 foul air gaining access to the wards, such diseases have greatly diminished, 
 or even totally disappeared. 
 
 As regards chemical composition, sewer air varies very widely. In 
 modern well-ventilated sewers the air is by no means foul. Samples collected 
 by Dr. W. J. Kussell from the metropolitan sewers in the Paddington district 
 during the month of August, 1869, were found to contain 0-51 volume of 
 carbonic acid, 20*7 of oxygen, and 78'79 of nitrogen in 100 volumes. In 
 so far as these constituents are concerned, the impurity is not great, and in 
 no way accounts for the mjurious properties of sewer air. 
 
 In the old-fashioned brick sewers, where sediment collects, the gaseous 
 impurity is often excessive. Brick conduits with flat bottoms (fig. 176), 
 circular or oval sewers in which a portion of the invert has sunk below its 
 proper level, and sewers which are too large for the volume of sewage they 
 ordinarily convey, are all liable to deposits of sediment on their floors or 
 sides, which can only be removed by artificial flushing. The bacterial agents 
 of putrefaction present in all sewers attack the sediment, and cause a fer- 
 mentation productive of the evolution of such foul gases as sulphuretted 
 hydrogen, ammonium sulphide, and carbon disulphide. Some of the other 
 foetid gases given off during the putrefactive process are highly complex 
 bodies, probably carbo-ammoniacal and allied in chemical constitution to 
 the compound ammonias — methylamine and ethylamine. These have a 
 highly offensive odour. Organic vapours of unknown constitution are also 
 evolved, and amongst these may occasionally be found traces of the animal 
 alkaloidal substances— ptomaines and leucomaines — which are contained in 
 the faecal and urinary excretions of the animal body, and exert a directly 
 poisonous action on the system. Free ammonia is also given off to a slight 
 degree by putrefying sewage, and is derived from fermentation of the urea 
 of urine — a molecule of urea takmg up two molecules of water to become 
 carbonate of ammonium. Of innocuous gases given off, the chief are carbonic 
 acid, nitrogen, and carburetted hydrogen. 
 
 Of late much attention has been directed to the organised constituents 
 of sewer air — to the microbes (bacteria and moulds with their spores). By 
 the method of plate cultivation of the microbial colonies on solid nutrient 
 media it is now possible to estimate the number of micro-organisms or their 
 spores present in a measured volume of sewer air, which are capable of 
 growing in these media at temperatures below that at which the solid medium 
 liquefies. Observations made by this method in this country tend to show 
 that sewer air, taken from sewers in which fermentative processes are in 
 abeyance, is remarkably free from all such microbes. The microbes remain 
 in the sewage, and are not given off to the air in contact with it, or if they 
 are, there is reason to believe that they quickly adhere to the moist internal 
 walls of the sewer, and are thus prevented from floating far. That such is 
 the explanation is rendered more certain by what is already known of the 
 presence of microbes in the outer atmosphere, for during dry or dusty 
 weather they are found in far larger numbers than during or after rainfall. 
 These experiments have been made on the air of sewers, in which the 
 
THE DISPOSAL OF BEFUSE 841 
 
 sewage is carried away in a fairly fresh and undecomposed condition. But 
 we believe that no extended observations have yet been made on the air of 
 those sewers where accumulations of putrefying sediment are to be found. 
 In such cases we are inclined to believe that the sewer air contains floating 
 in it an excessive number of microbes and spores. In the first place, there 
 is the almost universal domestic experience that meat, milk, and other 
 organic substances rapidly taint and putrefy when exposed to drain or sewer 
 emanations, and this points strongly to the presence of the bacterial agents 
 of putrefaction in such air ; and, secondly, it was demonstrated, as long ago 
 as 1871 by Professor Frankland, that, although liquids flowing smoothly in 
 channels give off no solid particles to the air, and that even considerable 
 agitation resulting in frothing may not cause any perceptible increase of the 
 solid particles in the superincumbent air, yet the bursting of bubbles of gas 
 in a liquid had a marked effect in disseminating solid particles. The burst- 
 ing of bubbles of gas on the surface of a liquid is an invariable accompani- 
 ment of the fermentative processes which take place in stagnant sewage and 
 sewage deposits, so that there can now be little doubt but that the air in 
 contact with putrefying sewage is loaded with micro-organisms of different 
 kinds. Frankland's conclusions, too, have been practically confirmed by the 
 •experiments of other and later observers. 
 
 And, after all, it is not so much a question of the quantity of bacterial 
 organisms present in sewer air as of the quality of those that do exist, 
 whether large or small in number. The fallacy of reasoning that, because 
 sewer air under ordinary conditions contains but few demonstrable organisms 
 it must ipso facto be innocuous, is sufficiently obvious to require no refutation. 
 Too little is known at present about the microbes present in sewers to 
 warrant dogmatic assertions of any kind, but it is believed that the large 
 majority are harmless or at least non-pathogenic. Others there may be, pre- 
 sent at times only, and then, perhaps, not in company with a crowd of 
 Jaarmless species, which are productive of those varieties of illness in the 
 human subject that are known to result from sewer-air poisoning. The 
 history of sanitation in this country, too, tends conclusively to show that 
 improvements in sewerage and house drainage, whereby sewer air is excluded 
 from houses and dispersed harmlessly in the external atmosphere, have 
 had a most beneficial effect upon the public health in the reduction of the 
 prevalence and mortality from typhoid fever and the other filth diseases. 
 
 The injurious effects attributable to the inhalation of sewer air may for 
 •convenience be divided into those produced by the foul inorganic gases, and 
 those resulting from the organic vapours or the organised constituents of such 
 air. Under the first head must probably be classed those cases of complete 
 or partial asphyxia which formerly occurred amongst the Paris scavengers 
 when engaged in removing deposit from choked sewers, or in emptying and 
 cleansing cesspools and privies. These asphyxial symptoms {le plomh) were 
 either caused by excessive disengagement of sulphuretted hydrogen gas, 
 when the contents of the sewers or cesspools were stirred up, or were due to 
 the very low proportionate volume of oxygen existing in the air, or to both 
 •of these causes combined. Thus Parent Duchatelet found the ah' of a choked 
 sewer in Paris to contam nearly 3 per cent, of sulphuretted hydrogen, and 
 only 13*8 per cent, of oxygen. 
 
 Cases of acute mephitic poisoning have been recorded amongst scavengers 
 employed in cleansing foul drains and sewers, the symptoms being sudden 
 and violent vomiting, purging, and headache, followed shortly by acute pro- 
 ;stration, sometimes ending fatally. These symptoms are probalaly as much 
 
842 HYGIENE 
 
 due to inhalation of foul organic vapours as to the inorganic compounds of 
 sulphur or ammonia. 
 
 At the present day, owing to the improved construction of sewers and 
 their better ventilation, such cases of asphyxia or acute poisoning amongst 
 the sewer men are very rare. As a rule, these men appear to enjoy very 
 fair health, no doubt because their work is now conducted in a relatively pure 
 atmosphere. But it must be remembered that they are picked men in the 
 prime of life, for only those continue at the w'ork who find no injury to health 
 arising from it ; probably many men give it up after a short trial, as being 
 unsuited to tlieir constitutions. It has also been stated that sewer men, as a 
 class, suffer somewhat from ophthalmia and headaches, and that the occupa- 
 tion tends greatly to aggravate venereal disease (Parent Duchatelet). It 
 seems fair to assume now, in the light of our present knowledge, that the 
 men engaged in this occupation undergo a species of preventive inoculation 
 or acclimatisation, so to speak, to the influences to which they are exposed. 
 The long-continued inhalation or ingestion of a germ-tainted air may be 
 considered as conferring immunity upon the individual from filth diseases 
 which would readily attack one whose system had not been exposed to the 
 acclimatising process. 
 
 The contamination of the air of houses with sewer or drain emanations 
 appears to be productive in many instances of loss of health amongst the 
 occupants, more especially in those cases where the escape of sewer air is 
 continued for long periods. The dose of the poisonous atmosphere may not 
 be sufficiently great at any one time to cause those acute and dangerous 
 illnesses before mentioned, but a condition of ill-health is engendered, 
 especially in children, shown in various ways, as by loss of appetite, pro- 
 stration, diarrhoea, antemia, headache, vomiting, sore throat, and fever. 
 One or more of these symptoms predominate over the rest, according to the 
 season of the year and the idiosyncrasies of the individual. Dr. George 
 Johnson has described cases of albuminuria and destructive kidney disease 
 as being the result of long-continued sewer-air inhalation. Whether ren- 
 dered seriously ill or not, a condition of depressed vitality is certainly a 
 marked characteristic of the inmates of a badly drained house. 
 
 It is now generally believed that these symptoms of illness are due to the 
 entrance mto the body of the organic matters present in the sewer air ; and 
 modern views regard the micro-organisms, which constitute a certain pro- 
 portion of these organic matters, as being the poisoning agents rather than 
 the gases and vapours, however complex in their chemical constitution. 
 Whether these microbes should be classed as pathogenic organisms, or 
 whether they are to be regarded as the ordinary bacteria of putrefaction and 
 fermentation, which on entrance into the body pervert the healthy action of 
 the tissues, causing diseased processes, is a problem the solution of which is 
 not yet reached. 
 
 It now becomes necessary to inquire into the causes which produce 
 movements of air in the sewers, for only upon a proper understanding of 
 this subject can any system of efficient sewer ventilation be founded. The 
 most important of these causes are : (1) a strong and rapid stream of sewage 
 tends to create a current of air in the sewer in the same direction as the 
 flow of sewage, and of proportionate velocity. Under such circumstances 
 many of the street openings into the sewers become inlets for fresh air, 
 which travels with the current of sewage and finally escapes at the sewer 
 outfall. (2) As the volume of sewage increases air is expelled from the 
 sewer, to again find its way in when the volume of sewage diminishes. As 
 a rule, the quantity of sewage passing down a sewer steadily increases from 
 
TEE DISPOSAL OF BE FUSE 843- 
 
 the early morning hours up to noon, and in the afternoon as gradually 
 diminishes, until at night in brick sewers little but subsoil water is being 
 conveyed. It follows, then, that in the morning air is being slowly expelled 
 from the sewers, whilst for the rest of the day the reverse action takes place.. 
 The sudden influx of a large quantity of storm water into a sewer causes a . 
 very appreciable expulsion of air ; but this is, to a certain extent, counter- 
 balanced by the aspirating effect of the current of air in the direction of the 
 flow of sewage. The rising of the tide in an outfall sewer unprotected by a 
 tidal valve also causes expulsion of air, but the displacement is so gradual 
 as to be almost inappreciable, owing to the slowness with which the water 
 rises and the innumerable channels permeable to air by which the interior 
 of a brick sewer communicates with the exterior. (3) During the colder 
 months of the year the temperature within a sewer is, owing to the warmth 
 of the sewage, considerably higher (averaging about 7° F.) than that of the 
 outer atmosphere ; consequently the warmer sewer air tends to rise and be 
 replaced by the colder air from above. In the summer months the day 
 temperature of the sewer is often below that of the external air, and the 
 interchange between the sewer air and the outer atmosphere is reduced to a 
 minimum. In the spring and autumn months the temperatures inside and 
 outside tend to approximate. (4) The discharge of large volumes of hot 
 liquids from houses and factories, and the practice of blowing off steam 
 from boilers into the sewers, causes heating and expansion of the sewer air 
 and its rapid expulsion through the nearest sewer openings. This more 
 especially follows the blowing off of steam, and sometimes, when the sewers 
 are insufficiently ventilated, results in the forcing of the traps on house 
 drains and pipes, and the escape of the foul air into the interiors of houses- 
 There is also the objection to the introduction of hot liquids or steam into 
 sewers that the decomposition of the sewage is accelerated by the high 
 temperature to which it is raised, and that, in consequence of the saturated 
 condition of the air and its high temperature, the sewer cannot be entered 
 until it has been opened to the air for some time by means of the manholes,, 
 and thus a difficulty is placed in the way of frequent inspection. (5) Sudden 
 changes of barometrical pressure and of external temperature cause corre- 
 sponding variations in pressure within the sewer, resulting in the passage of 
 air, as the case may be, into or out of the sewer. 
 
 If the sewers have no ventilation openings, or if, for any reason, these 
 have become choked or stopped up, the air within, from the causes above 
 mentioned, will find its way out through defective joints on house drains or 
 soil pipes, through bell-traps in floors or on waste pipes, into the interiors of 
 houses in all those eases where there is no disconnection trap on the house 
 drain ; and these escapes of sewer air tend to become aggravated by the 
 aspirating effect of fires and the warmth of inhabited houses on the colder 
 air contained in the drain and soil pipes. In houses of this class the rain- 
 water pipes from the roof, being directly connected with the house drain and 
 sewer, without the intervention of a trap, may act as sewer ventilators. 
 But such a plan is a dangerous one, as these pipes are usually very loosely 
 jointed, and the air rising from the sewer will escape through every such 
 joint, possibly into bedrooms ; and in many cases the open head of the pipe 
 is just beneath a dormer or attic window. During heavy rain, too, the rush 
 of water down these pipes will force the foul air into the ulterior of the 
 house through trapped or untrapped openings. 
 
 The ventilation of sewers by means of the soil-pipe ventilators of houses 
 is equally objectionable, except where the sewers are stoneware pipes laid 
 between the backs of two rows of houses, for then the drains will not pass 
 
•844 HYGIENE 
 
 under the basements of houses, and the entry of sewer air into the house 
 may be prevented by trapping and disconnecting all waste and overflow 
 pipes, and substituting siphon gullies for bell-traps. But where houses 
 drain into sewers laid in the front road, the drain must pass under the 
 house, and with this method of sewer ventilation there would be constant 
 risk of the escape of sewer air through defective joints into the interior of 
 the house. There is also another objection to this method, which applies to 
 the case of sewers which receive rainfall. During or after heavy rain, when 
 ventilation is most required for alibrding a safe exit for suddenly displaced 
 sewer air, house drains, or any part of them, are often useless for this purpose, 
 as their openings into the sewer may be sealed by the height at which the 
 mixed sewage and storm water is flowing. This is also a valid objection to 
 the practice of carrying up a ventilating pipe to the roof from the house 
 drain on the sewer side of a disconnecting trap. At ordinary times it may 
 serve as an exit for sewer air, but when its services are most required it is 
 liable to fail. 
 
 The simplest method of ventilation, and the only one that is in most 
 cases practicable, is to construct a shaft leading fi-om the crown of the sewer 
 to the surface of the roadway above, the opening at this spot being protected 
 by an iron grid. Immediately below the gratings should be fixed a dirt-box 
 to catch mud and gravel that would otherwise fall into the sewer, a space 
 being left around the box for the passage of air to and from the sewer. 
 
 These surface roadway ventilators should be constructed at not greater 
 distances apart than 100 yards — say eighteen to a mile — and where the sewers 
 are flat, or for any reason not self-cleansing, the ventilators should be even 
 nearer together. In the metropolis the average distance apart is 120 yards, 
 and the shafts are circular in shape and about 18 in. in diameter, with a 
 superficial area for ventilation of 254-5 square inches. The openings in the 
 gratings are, however, very much smaller, varying from 27 up to 70 in. of 
 superficial area, and thus the large size of the shafts is rendered absolutely 
 inoperative by the small size of the gratings. 
 
 Another plan which is largely adopted is to combine a ventilator with a 
 vertical manhole (fig. 179). A ventilating shaft is smik for some distance by 
 the side of the manhole, and openings are left between them for the passage 
 •of air. Mud and stones falling into the ventilator can be removed through 
 the manhole by the scavenger, but the water is carried by a pipe into the 
 sewer beneath. 
 
 Some of these surface ventilators will be found to act as inlets for fresh 
 air, and others as exits for foul air, varying from day to day, and from hour 
 to hour, according to the special circumstances affecting the movements of 
 the sewer air, as previously described. The sewer air escapes towards the 
 centre of the roadway, where it is rapidly diluted with fresh air, with the 
 least chance of oflence to foot passengers on the sidewalks, or of finding an 
 entrance into houses through open doors and windows. 
 
 Nevertheless, these surface ventilators are often productive of considerable 
 nuisance in hot weather or during periods of drought. The ofi"ensive smells 
 that are then perceptible are a warning that a deposit of sediment has taken 
 place in the sewer below, and when this is removed or flushed away the 
 nuisance ceases. There may not, however, be sufficient dilution of the sewer 
 air with fi-esh air, and then it becomes necessary to increase the number of 
 roadway ventilators, or to supplement their action by constructing shafts 
 6 in. or more in diameter, leading from the crown of the sewer to the side of 
 the road and thence up houses or buildings, clear away from all windows and 
 chimneys. These shafts, being carried up to a considerable height above the 
 
TRE DISPOSAL OF BEFUSE 845 
 
 ground, will act principally as exits for foul air; whilst the surface ventilators 
 will become inlets for fresh air, and nuisance arising from the escape of sewer 
 air in the streets will be to a great extent obviated. 
 
 These shafts have proved of great service for ventilating the upper or 
 dead ends of sewers in narrow enclosed courts or streets, where the sewer air 
 escaping from the surface ventilators is not rapidly diluted by fresh air owing 
 to the obstruction offered by surrounding buildings. In these cases con- 
 siderable collections of foul sewer air, productive of great nuisance and 
 injury to the health of the inmates in the surrounding houses, may occur 
 on calm days. 
 
 Pipe ventilation up the sides of the houses should be used to supplement 
 the existing surface roadway ventilation, and not to take its place. For, if 
 used for the latter purpose, the efficiency of the whole sewer ventilation would 
 be greatly impaired by the obstruction offered to the passage of air in these 
 long pipes with their numerous bends and turns. In any case they must be 
 fixed with great care to the houses, and the joints must be made thoroughly 
 secure to avoid any risk of foul air entering houses through windows and 
 chimneys. It is, perhaps, for this reason that local authorities have found 
 so much difficulty in obtaining the consent of house owners to the erection 
 of these shafts against their outer walls. 
 
 Street gullies should not be used as sewer ventilators, but should be 
 effectually sealed with water, both to prevent road detritus entering the 
 sewers, and to prevent the escape of sewer exhalations close to the footways 
 and the fronts of houses. In dry weather, street gullies should be periodically 
 recharged with water from a watering cart. 
 
 It was formerly the custom to filter the sewer air escaping from the 
 manhole and other surface ventilators through wood charcoal contained 
 in iron-wire baskets ; but it soon came to be recognised that the deodorisa- 
 tion of the sewer air lasted only so long as the charcoal was dry, and that 
 when the charcoal became damp — as it very soon did — its pores were clogged, 
 and then it obstructed all passage of air. There can be no doubt that, when 
 dry, wood charcoal has considerable effect in deodorising sewer air by oxidis- 
 ing organic vapours, as is shown by the fact that nitrates and ammoniacal 
 compounds can be recovered from the used charcoal. But when placed in 
 the ventilators it soon becomes wet from rain and moisture, and requires to 
 be recarbonised about once every month or six weeks. For these reasons 
 charcoal filters have now been nearly everywhere discontinued. 
 
 Various other plans have from time to time been suggested, with a view 
 to the deodorisation of the sewer air escaping from ventilators by means of 
 chemical gases or solutions of supposed antiseptic properties. And a method 
 of passing all the air so escaping through a ring of gas burners, known as 
 Keeling's Extractor, has also been tried. Here the escaping gases are 
 actually burnt, or at least very highly heated. The same objections apply to 
 all such methods. Their initial cost is large ; they require a considerable 
 amount of attention, involving labour and expense ; and if they are successful 
 in accomplishing what they are intended to do, viz. the mitigation or preven- 
 tion of nuisance, they tend to conceal a condition of things in the sewers which 
 is in itself injurious, and which being unknown or unnoticed, fails to receive 
 the proper remedy. They do not, therefore, in any way go to the root of the 
 evil, but gloss it over by getting rid of the chief evidence of its existence. 
 
 In sewers laid with steep gradients a current of au* tends to pass up from 
 the low to the high levels in the reverse direction to the flow of sewage. 
 This is more especially likely to happen in cold weather, when the sewer air 
 is at a considerably higher temperature than the external atmosphere. The 
 
8i6 
 
 HYGIENE 
 
 offensive gases escape at tbe liigh levels, and are the subject of very general 
 complaint. The remedy lies in constructing at various points on the sewers 
 of steep gradient a tumbhng bay with manhole and ventilator (fig. 180), and 
 with a flap-valve applied to the mouth of the sewer delivering sewage from 
 the higher level. Then the sewer air in its course upwards meeting the 
 flap-valve is forced to escape into the outer air through the ventilator, and 
 so does not reach the higher part of the sewer. 
 
 The plan of connecting sewers with the chimneys of furnaces has now 
 been abandoned. The draught up the chimney creates a very strong current 
 of air in the sewer for a short distance, but the efl'ect very rapidly diminishes 
 as tbe distance, increases, for air rushes in from all openings in the nei<i-h- 
 bourhood to supply the place of that extracted by the furnace. In this way 
 the traps on house drains and pipes are liable to be drawn, and when the 
 furnace is not working foul air may pass back into the houses. There is 
 
 besides the risk of an 
 explosion from ignition 
 of coal gas which may 
 accidentally find its way 
 into the sewer, as hap- 
 pened in Southwark, 
 where the sewers were 
 connected- with the fur- 
 naces of soap works. 
 
 The ventilation of 
 pipe sewers is a subject 
 which has been care- 
 fully considered by Dr. 
 Buchanan in his report 
 upon the epidemic of 
 enteric fever at Croydon 
 m 1875. There is much 
 less tendency to the de- 
 posit of sediment in pipe 
 sewers than in brick 
 sewers, owing to the 
 smooth internal walls of 
 the former, and to the 
 frequency with which 
 ihey are runnmg full or nearly full, so that the whole of the interior is 
 periodically washed. For this reason pipe sewers are but seldom productive 
 of offensive gases. But the air within them, if there are no ventilation open- 
 ings, is liable to be under far greater pressure than the air in the larger brick 
 sewers, for the reason that the sudden entrance of a volume of water into a 
 sewer of small diameter causes a far greater and more sudden displacement 
 of air than if it entered a large sewer, and that the air so displaced has less 
 chance of escaping, owing to the material of which the sewer is made not 
 being porous. For example, the entrance of a volume of water into a 6-inch 
 pipe sewer will cause a displacement of air sixteen times as great as, and much 
 more sudden than, if the same volume of water entered a 2-foot sewer. The 
 displaced air may be comparatively inoffensive, but, as Sir George Buchanan 
 has shown, offensiveness is no criterion of the infectiveness of sewer air, and, 
 as the Croydon experience proves, the entrance of such air through un- 
 trapped drain pipes into houses may be productive of an attack of typhoid 
 fever. 
 
 Fig. 180. — Brick sewer with tumbling bay and connection with 
 ventilating manhole. 
 
THE DISPOSAL OF BEPUSE 847 
 
 In the pipe system of sewerage, then, adequate ventilation is imperatively 
 needed, and the shafts required for this purpose may be combined with the 
 inspection openings which we have seen to be necessary for the purpose of 
 removing obstructions from the pipes. 
 
 Outfall Sewees 
 
 Until the passing of theEivers Pollution Prevention Act, and even to the 
 present day in Dublin and some other large towns, the town sewers took the 
 shortest available course to the banks of the river or stream on which the 
 town was situated, and there discharged each by its own outlet. To prevent 
 pollution of watercourses in the centre of populated districts, it became 
 necessary to construct intercepting sewers of large size to receive the sewage 
 of the tributary sewers. The intercepting sewers were united to form one or 
 more large main outfall sewers, which conveyed the sewage outside the town 
 and conducted it to the works constructed for its purification, or in its crude 
 condition to its outfall into the river, as the case might be. 
 
 Outfall sewers discharging into the sea or a tidal river are very frequently 
 a considerable source of nuisance in towns situated at so low a level that the 
 gradients are small, and the sewage is tide-locked for some hours of each 
 tide. A tidal valve at the mouth of the sewer prevents tlie ingress of sea- 
 water, but the sewage which flows from the town during the tide-locked 
 period has to be stored in the outfall sewer. Here it stagnates, depositing a 
 very copious sediment. The tributary sewers also under such circumstances 
 tend to have sewage backed up into them, and the decomposition of the 
 sediment gives rise to so copious a formation of gases that no amount of 
 ventilation will quite obviate the nuisance. 
 
 Until recently sewage engineers did not appear to have realised the im- 
 portance of preventing sewage stagnation in outfall sewers, and placed 
 too much confidence in the scouring effect of large volumes of liquid with, 
 however, but little head. It is certainly advisable that, in all such cases, 
 tanks should be constructed to receive the sewage delivered by the outfall 
 sewer, which can be subsequently pumped away, or that steam or compressed 
 air-pumping machinery should be utilised to relieve the sewers of their tide- 
 locked sewage. 
 
 It sometimes happens that the sewage of a town has to be carried across 
 a valley or river. If the outfall sewer is at too low a level to admit of bridging, 
 it must be carried across by means of an inverted siphon, formed of wrought- 
 iron pipes with riveted flange joints laid in the bed of the river or valley. 
 The sewage must be strained of its larger solid bodies before passing through 
 the siphon, or the siphon must be periodically flushed to get rid of the 
 accumulation of solid matters at its lowest point, resulting eventually in 
 complete choking, an occurrence which usually happens unless the current 
 through is of sufficient velocity to carry all solid matters with it. A ventilating 
 pipe should be attached to the descending arm, to give exit to air under 
 pressure in the siphon, which might prevent its proper action. 
 
 The Shone System 
 
 This system is intended for use in towns situated on low-lying or very 
 level ground, where the sewage has to be pumped to the outfall, or where 
 the sewers have to be laid with very small gradients. The leading 
 feature of the system is the method of raising the sewage by means of com- 
 pressed air at such points as are convenient on its course to the outfall. 
 
848 
 
 HYGIENE 
 
 The air is compressed at a central station, and is then conveyed by 
 2-ineh wrought-iron pipes to the ejectors, situated in chambers below the 
 surface of the streets at different parts of the town (fig. 181). These ejectors 
 receive the sewage from the street sewers, and when full the compressed air 
 is admitted into them by appropriate mechanical arrangements, and the 
 
 sewage is forced out. If the air is compressed to the extent of 15 lb. to the 
 square inch (=one atmosphere) the sewage will be raised to the height of 
 34 feet in the discharge pipe from the ejector. This discharge pipe is con- 
 nected with an ordinary gravitating sewer, or the ejector discharges directly 
 into a ' sealed ' sewer of cast-iron pipes, when it is necessary that the rise 
 
THE DISPOSAL OF BEFUSE 849 
 
 .should be more gradual and continued over a greater distance. The ejectors 
 .are placed at a depth below the surface of the ground sufficient to permit ol 
 the house drains and street sewers being laid at good gradients, the sewage 
 ■entering them by gravitation. The ejectors are made of various sizes, 
 ■depending upon the amount and the maximum rate of flow of the sewage 
 they are required to receive. 
 
 The advantages claimed for the system are as follows : — 
 (1) Good gradients being given to the sewers, the sewage is carried to 
 ihe ejectors, and forced out of the town, in a fresh and undecomposed state. 
 (2) No storage is required, as in ordinary pumping, where the rate of flow of 
 the sewage may exceed the powers of the machinery ; for the rate of working 
 •of the ejectors varies with the rate of flow of the sewage, although the rate of 
 working of the machinery for air compression is nearly uniform. (3) Com- 
 pressed air is a motor that can be conveyed and divided amongst any number 
 •of stations near to or far apart from each other without any appreciable loss 
 either by leakage in the pipes, if properly laid and jointed, or by friction, 
 the only loss being that due to clearance of compressed air from the ejectors 
 when discharged. (4) The air can be compressed at one station, so that one 
 staff only is required, as in the case of a single outfall. (5) The temperature 
 of the compressed air is very nearly the same as that of the outside atmo- 
 sphere, so that, as compared with steam, there is no loss of heat by radiation 
 from the pipes conveying it. 
 
 Shone's system has been adopted at Eastbourne, Wrexham, Southamp- 
 ton, Warrington, Henley-on-Thames, and at the Houses of Parliament, 
 Westminster. It certainly seems well adapted for those places in which 
 absence of proper gradients causes silting up in the sewers, and in practice 
 it has been found to realise the expectations formed of its working. 
 
 The Librnuk System 
 
 In this system every house must be provided with two sets of drains — one 
 for household waste waters and rain water, the other for the f^cal matters 
 from cabinets d'aisance without water supply, for the water-closet sewage, 
 and for bedroom slops containing urine. The first set of pipes joins the pipe 
 drains in the street, which receive rain water and the waste liquids firom 
 factories, and the contents are finally discharged into the nearest watercourse 
 (canals in Holland). 
 
 The cabinets d'aisance, or ' air-closets,' as they are termed, consist of 
 ■cast-iron hoppers with siphon traps, but without water supply. They are 
 connected with the branch sewer pipes in the street by means of 5 -inch 
 cast-iron soil pipes, trapped with a siphon bend below, and continued up above 
 the roof by 2-inch ventilating pipes. 
 
 The branch sewer pipes are also 5-inch cast-iron pipes with gas-tight 
 joints. These pipes are laid in lengths of long downward slopes of 1 in 250, 
 and short upward slopes of 1 in 5, forming inverted siphons, where the 
 sewage matters rest at varying heights, according to the volume of sewage. 
 These inverted siphons are ultimately connected with a cyhndrical iron 
 reservoir placed below the surface of the street in the centre of a district of 
 from fifteen to forty acres, the town being divided into these districts. These 
 reservoirs are connected with the works outside the town, where air- vacuum 
 pumps are at work, by two sets of pipes. The smaller set are the air-pipes 
 opening into the top of the reservoir, and the larger set opening from the 
 bottom of the resevoir serve for the transport of the sewage to the works. 
 
 A vacuum is produced within the street reservoir by connecting it with 
 
 VOL. I. 3 I 
 
850 HYGIENE 
 
 the works ; the valve on the street sewer pipes is then turned, and the sewage 
 from the branch sewers is sucked into the reservoir. As soon as this is 
 nearly full, air is admitted, and the sewage is then sucked into a reservoir at 
 the works. The arrangement of the branch sewer pipes as inverted siphons 
 causes approximately equal emptying of their contents into the street 
 reservoir. In those branch pipes that are full the sewage will stand up to 
 the top of the bend of the siphon, and will consequently be more easily 
 drawn away than those which are less full, and in which the sewage has to 
 pass up a greater length of the bend. As soon as the levels of sewage in the 
 siphons of all the branch pipes are the same, they are all emptied equally 
 until bubbles of air begin to pass, when no more sewage flows, leaving the 
 pipes still trapped. 
 
 In Amsterdam, where the Liernur system is at work, the sewage contains 
 but little diluting water, as the majority of the closets in the town are ' air- 
 closets ' without water supply. At the works outside the town the sewage is ■ 
 further concentrated by heat, and dried in revolving cylinders, when it issues 
 as a powder — said to be worth 8 francs per 50 kilos, (about 6L 10s. per ton). 
 
 The system appears to be well adapted for flat towns intersected by 
 numerous canals, such as are to be found in Holland, where sewerage by 
 gravitation presents great difficulties ; and it certainly appears as if it could 
 be ordinarily conducted without the production of offensive odours, either 
 given off from the street reservoirs or from the ' air-closets ' within the 
 houses. 
 
 The Berliek System 
 
 This system has been adopted in one of the districts of Paris. In prin- 
 ciple it is very similar to that of Liernur. The house drains are connected 
 with iron pipes, in which a partial vacuum is maintained by means of an air 
 pump, so that the sewage is conveyed from the houses by pneumatic pressure 
 to the pumping station, which may be outside the town. 
 
 The distinguishing feature of the Berlier system is its automatic action, ^ 
 which is a great improvement on the Liernur plan, in which the pipes and 
 receivers can only be emptied by the opening of valves by hand. In the 
 Berlier system every house drain is provided with an air-tight receptacle, in 
 which the sewage collects until nearly full, when by a floating-valve arrange- 
 ment the aperture leading to the sewer pipes is automatically opened, and 
 the sewage is sucked away. 
 
 The system seems to be well adapted for Paris, where the existing sewers 
 being so entirely unsuited to the water-carriage system of excrement removal, 
 excretal refuse must be retained in the vicinity of houses m cesspools, or in 
 some form of midden pit or dry closet, unless it be removed in a system of 
 small sewers not depending on gra\itation as a motive force. 
 
 THE DISPOSAL OF SEWAGE 
 
 The Elvers Pollution Prevention Act of 1876 made it illegal to discharge 
 crude sewage into a stream, this term including rivers, streams, canals, lakes, 
 and watercourses other than those mainly used as sewers, and also the sea 
 to such extent, and tidal waters to such point, as may after local inquiry, or 
 on sanitary grounds, be determined by the Local Government Board. This 
 Act has very generally been disregarded during the dozen years and more 
 it has been supposed to have been in operation, owing to the magnitude of 
 the interests involved in the continuation of the old conditions. By the 
 
THE DISPOSAL OF BEFOSE 851 
 
 Local Government Act, 1888, the duty of preserving the purity of our streams 
 and rivers has been in part transferred from the local sanitary authorities to 
 the County Councils, and it is to be hoped that this transference of powers 
 will be followed by a more adequate enforcement of the provisions of the 
 Act. 
 
 It will be advisable at this point to consider briefly the effects produced 
 by the discharge of crude or incompletely purified sewage into fresh running 
 water. 
 
 The magnitude of the evils which result from this practice is to a con- 
 siderable extent dependent upon the proportionate volumes of sewage and 
 clean water thus mixed together. If the sewage is comparatively small in 
 volume, and is at once largely diluted with clean river water, it becomes in 
 course of time to a great extent purified. The chief agent in this purifying 
 process is the atmospheric oxygen dissolved in the water, which has con- 
 siderable oxidising effect upon the organic matters of the sewage. As this 
 dissolved oxygen becomes used up, a fresh supply is absorbed from the air ; 
 but actively growing aquatic plants also give off oxygen and reoxygenate the 
 water, thus enabling the process of purification by oxidation to continue. 
 Besides the water-plants, minute animals (infusoria, entomostraca or water- 
 fleas, anguillulidte or water- worms) are found in countless numbers in the 
 polluted reaches of rivers ; and these feed on some of the organic impurities 
 of the sewage, and thus contribute towards the purifying process. The 
 coarser kinds of fish, too, the carp, roach, and chub, feed on some of the 
 elements of the sewage, and aid the process of purification. The suspended 
 matters of the sewage tend to deposit largely in streams with sluggish current, 
 and thus may be productive of nuisance in the immediate neighbourhood of 
 the sewer outfalls ; whilst the water below, being relieved of their presence, 
 is in a better position to benefit by the natural oxidation processes. The 
 agitation of the water and its exposure to the air, brought about by its 
 flowing over rapids or falling over weirs, exerts a marked beneficial influence 
 on its quality — no doubt from the increased oxidation of organic matters. 
 
 That polluted river waters can undergo self-purification is now very 
 generally recognised. The essential conditions are that the polluting liquids 
 shall be rapidly diluted with a large volume of clean water, allowing the 
 natural purifying agencies of oxidation and animal and vegetable aquatic life 
 free play. The completeness with which this self- purification is accomplished,. 
 or, in other words, the question as to whether a river water once polluted 
 with sewage can ever attain its original purity or be a proper source of water 
 supply, is one which we are not called upon to discuss here. It is sufficient 
 to state that under favourable conditions polluted river waters can regain 
 that state of purity which, as evidenced by chemical and biological exami- 
 nation, they formerly possessed. But, practically, in this country rivers 
 which are once polluted with sewage so continually receive fresh accessions 
 of sewage from the towns situated lower down on their banks that the pro- 
 cesses of self-purification are brought to a standstill, and the contammation 
 of the water gradually but constantly increases from the source to the mouth 
 of the river. 
 
 Under these circumstances the dilution of the sewage with clean water is 
 insufficient. The dissolved oxygen in the water is used up in the processes of 
 oxidation of organic matters ; the fish, first of all, and subsequently the lower 
 forms of animal and vegetable aquatic life, are destroyed by the absence of 
 dissolved oxygen or by the presence of noxious organic matters in the water, 
 and then the natural oxidation processes come to an end. Putrefactive pro- 
 cesses are started by a great increase in the numbers of the bacterial organ- 
 
 3i2 
 
S52 HYGIENE 
 
 isms, fermentative changes take place in tlie organic matters, and foul gases 
 are evolved. The bed of the river becomes coated with a deposit of decaying 
 sediment, particles of which, buoyed up by the gases, occasionally rise to the 
 surface to sink again, and a nuisance of a most injurious character results. 
 
 The nuisance is most marked during a period of warm weather. In the 
 cooler months of the year the oxidation processes may be in action to a consi- 
 derable extent ; but on a rise of temperature, especially if the volume of clean 
 water becomes at the same time diminished by absence of rainfall, the growth 
 of bacterial organisms becomes stimulated to such an extent that decomposi- 
 tion sets in and replaces the ordinary processes. This happens to the Thames 
 below London in the neighbourhood of the sewage outfalls pretty nearly 
 every summer, when the temperature is high and the land water small in 
 amount. During the rest of the year the river is not so productive of 
 nuisance, although there can be but little doubt that its purifying powers 
 are at nearly all times being tested to the height of their capacity. 
 
 The discharge of crude town sewage, then, into rivers is a practice fraught 
 with so many evils and dangers that it cannot be too strongly condemned 
 in all cases where towns or villages are situated on the banks lower down, or 
 •derive their water supply from the polluted source. 
 
 The discharge of sewage into the tidal waters of rivers and into the sea 
 must next engage our attention ; and here, of course, there can be no ques- 
 tion of contaminating potable waters, for now, at any rate, the provision 
 of water for domestic purposes from the tidal portions of rivers is unknown. 
 
 In the case of the tidal waters of rivers the reports of the Royal Com- 
 mission on Metropolitan Sewage Discharge throw considerable light on the 
 part played by the currents and tides on the sewage discharged into them, 
 and serve entirely to negative the idea pre'sdously entertained that sewage 
 ■discharged into a tidal water is at once carried away to sea. 
 
 In the first place, it is pointed out that the only true sources of dilution 
 of the sewage are the land water entering from above, and the sea water 
 passing up from the mouth of the river. The displacement of the sewage 
 towards the sea depends to a very great extent upon the volume of land water 
 entering from above. When this is but slight m amount, owing to absence 
 of rain, the sewage is displaced towards the sea with great slowness ; in the 
 case of the metropolitan sewage the displacement in dry weather is said to 
 be only a quarter of a mile daily. The result is that the sewage discharged 
 at high water on any particular day is carried down with the tide and then 
 back again to within a very short distance of the outfall. At each high tide 
 it receives a fresh accession of sewage, so that a considerable accumulation or 
 concentration of sewage in the river takes place, forming what has been 
 termed a ' sewage zone,' and this is entirely due to the tidal oscillations. It is 
 evidently a mistake, then, to regard the river water into which sewage is dis- 
 charged at Barking or Crossness as clean water ; it is, m fact, water that by 
 reason of the tidal oscillations has already become the recipient of an accumu- 
 lation of successive previous sewage discharges. 
 
 There is still another drawback to be considered in connection with the 
 discharge of sewage into a tidal river. Any sewage which is not discharged 
 wdthin a short period after high water will be carried up by the flowing tide 
 above the outfall ; and when neap tides are gi\'ing place to spring tides the 
 whole volume of discharged sewage is carried up daily higher and higher 
 above the sewer outfalls as the spring tides increase. In this way sewage 
 may be carried up into the heart of London, or even above it. 
 
 It is necessary, then, to store up the sewage at the outfalls in a reservoir 
 and to discharge it as quickly as possible at the top of the tide. But at high 
 
THE DISPOSAL OF BEFUSE 85^ 
 
 water there is a larger proportion of sea water in the river than at any other 
 time, and the various salts contained in the sea water cause a considerable 
 precipitation of the organic matters in the sewage. The processes of purifica- 
 tion by oxidation are lessened by the presence of these salts, and there is a 
 greater tendency to the deposition of sewage mud than if the sewage was dis- 
 charged into fresh water. 
 
 The silting up of the bed of the river and the formation of mud banks and 
 shoals is a very serious matter in the case of navigable waterways. There 
 can be little doubt that the solid matters of the sewage are largely deposited 
 in the neighbourhood of the sewer outfalls, and are not to any great extent 
 carried out to sea in a state of suspension in the water. 
 
 The nuisance that may result from the emanations of a sewage-polluted 
 river is patent to all, but the question of injury to health from such emanations 
 is one more difficult to decide. In the case of the metropolitan sewage the 
 Commissioners agreed that indisposition and a low state of vitality amongst 
 those who were actually upon the river or lived on its margin might be 
 attributed to its offensive condition, but the smell was in no case perceptible 
 a short distance away from the river ; and in the case of towns or villages 
 upon its banks it was found impossible to separate the influence of the river 
 from other causes productive of high mortality, which were very generally 
 present. 
 
 The discharge of crude sewage into the sea rests upon a somewhat 
 different footing from its discharge into a tidal river. Here the volume of sea 
 water is so enormous in comparison with the sewage that if it can only be 
 ensured that the sewage at once mixes with a large volume of sea water, the 
 dilution of the offensive organic matters is sufficiently complete to render 
 them innocuous. Certain conditions, however, must be observed to arrive at 
 so satisfactory a result. 
 
 The position of the outfall with regard to the town must be so chosen 
 that the sewage will always be canned out to sea, independently of the tides, 
 and the possibility of its return avoided. Should there be only one current, 
 setting in at a particular tide, available for carrying the sewage away, then a 
 reservoir must be provided for storing the sewage at such states of the tide 
 as are unsuitable to its discharge. In the case of a current setting along the 
 shore, rather than off it, the sewer outfall should, of course, be placed at 
 that extremity of the town which will prevent the sewage being carried along 
 the whole sea front. The prevailing winds must also be carefully studied, so 
 that floating matters in the sewage may not be blown back towards the town. 
 The mouth of the outfall sewer should be below the level of the water at all 
 states of the tide, and should be provided with a tidal valve to prevent the 
 ingress of sea water. 
 
 In certain towns where these conditions have not been fulfilled the sewage 
 discharge has been productive of much nuisance. The sewage has been 
 borne along the whole sea front of a town by the set of the currents, and foul 
 matters have been deposited on the foreshore, to the great detriment of the 
 health reputation of these towns as watering places. 
 
 It is generally recognised that sewage discharged into a river or sea is 
 altogether wasted ; but this opinion is not shared by Sir John Lawes, who 
 believes that the sewage is to a certain extent utilised by the fish feeding 
 upon that which the sewage produces. The sewage which is discharged into 
 the Thames he considers to be at first more suitable for animal than for 
 vegetable life, but the products of the animal life become food for vegetation, 
 and this vegetation in its turn is the food for fish. The removal of the 
 sewage from the river, or even the removal of the sedimentary portion by 
 
654 HYGIENE 
 
 means of lime, would, Sir John Lawes thinks, be followed by a most serious 
 reduction in the present quantity of fish. And he further adds : ' Looking at the 
 great cost which must be incurred before the sewage could be employed 
 beneficially upon land, it is quite probable that as a source of national wealth 
 its value is greater in its present state than it can be by any other process 
 apphed to it.' 
 
 Apart, however, from the fact that great injury has been done to the fish- 
 ing interest in the Thames itself — for the fish which formerly abounded in 
 the river as high as London have now been driven down below Gravesend by 
 the sewage discharge — we have it, on the great authority of Prof. Huxley, 
 that all the great sea fisheries are inexhaustible ; that is to say, that nothing 
 man can do can seriously affect the number offish in the sea. Mr. C. E. 
 Fryer, of the Government Fisheries Department, has also pointed out that the 
 fishery of all others that has shown the most marvellous growth is the Scotch 
 herring fishery, which has always been prosecuted far from the influence of 
 sewage discharge, and is every year beiiig carried on more and more success- 
 fully at a greater distance from the shore. He also states that the 600,000 
 tons of fish annually brought ashore in this country are collected from an 
 area of about 150,000 square miles, with a maximum depth of about 350 feet ; 
 and he asks, How are the constituents of London sewage to be spread with 
 anything like uniformity over this vast area ? We consider, then, that Sir 
 John Lawes has entirely failed to show that the sewage cast into the sea is 
 not completely and utterly wasted. 
 
 THE PURIFICATION AXD UTILISATION OF SEWAGE 
 Its Chemical CoMrosiTiON and Value 
 
 We have already seen that the discharge of crude sewage into streams, 
 the estuaries of rivers, or into the sea, means the entire waste of such 
 valuable manurial ingredients as the sewage may contain. Owing to the 
 density of population in this country, and the large numbers of towns and 
 villages on the banks of every stream and river, the discharge of crude 
 sewage into these watercourses is almost invariably productive of nuisance 
 to a greater or less extent, and of injury to the fishing and other interests, 
 which are entirely dependent upon the purity of river water. Li the 
 case of all towns, therefore, which are unable to get rid of their sewage 
 directly into the sea, the problem of purification of the sewage before dis- 
 charge has to be attacked, and the question at once arises — Is it worth while 
 to attempt the utilisation of the manurial ingredients of the seioage ? and as 
 a corollary — Is it possihle to practically combine utilisation with purification, 
 and to make the process pay the whole or part of the expenses incurred in 
 its adoption ? Our first concern, then, must be to consider what are the 
 amounts and values of the manurial ingredients contained in ordinary town 
 sewage, and how far is it possible to reason from such theoretical considera- 
 tions on the value of sewage or sewage products to the practical farmer. 
 
 The Eivers Pollution Commissioners in their first report gave the average 
 composition of sewage in water-closeted towns as represented in the table 
 on page 855. 
 
 The quantity of nitrogen existing as nitrates and nitrites is inappreciable. 
 
 This composition represents an average of a large number of analyses, 
 and being merely an average its approximation to the average strength of 
 sewage in any town can only be determined by actual experiment and observa- 
 tion. The sewage of different towns will vary very greatly in character accord- 
 
THE DISPOSAL OF EFFUSE 
 
 855 
 
 "5ng to the proportionate number of water-closets to dry closets or middens 
 in the town, according to the amount of water supply per head of the popula- 
 
 In 100,000 parts. 
 
 Suspended Matters 44-69 
 
 Solid Matters in Solution 72-2 
 
 Organic 
 
 Mineral 
 
 Organic 
 Carbon 
 
 Organic 
 
 Nitrogen 
 
 Ammonia 
 
 Total Combined 
 Nitrogen 
 
 Chlorine 
 
 20-51 
 
 24-18 
 
 4-696 
 
 2-205 
 
 6-703 
 
 7-728 
 
 10-66 
 
 tion, according to the amount and composition of the wastewaters discharged 
 from manufactories into the sewers, and, most of all, according to whether 
 .brick sewers are in use, which receive storm waters and allow subsoil water 
 to percolate through their walls, or a separate system of pipe sewers has been 
 adopted for the exclusion of surface and subsoil water. With the system 
 of pervious drain sewers the dilution of the sewage during and after rainfall 
 is often so great that the mixed rain and sewage has very few of the 
 characteristics of sewage. Under the pipe system, on the other hand, the 
 .average strength of the sewage tends to be maintained independently of 
 rainfall throughout every day of the year. 
 
 Not only does the sewage of different towns vary so greatly in composi- 
 tion, but the sewage of the same town — more especially where the sewers 
 are of pervious materials — varies in strength from day to day, and from hour 
 -to hour. The daily variations depend largely upon the occurrence or absence 
 ■of rain, whilst the hourly variations are occasioned by the habits of the 
 populations. Thus, the sewage is strongest during the hours of the forenoon, 
 and its flow greatest, whilst at night the sewers may be discharging nothing 
 but subsoil water. 
 
 From these considerations, then, it will become evident that to obtain an 
 ■exact knowledge of the average strength of a day's sewage in any town, 
 samples must be taken at least every hour, and these samples must be mixed 
 :in order to procure an average sample for analysis — not in equal proportions, 
 but in such proportions as are indicated by gauging the floio of sewage at 
 the time each sample was taken (as first pointed out by the British Associa- 
 tion Sewage Committee). This precaution is necessary in order that an 
 average sample may be procured ; that is to say, a sample which would 
 be identical in composition with that which would be obtained if the day's 
 sewage flowed into a tank large enough to contain it all, and was well mixed 
 'before the sample was taken. 
 
 In the same way the average yearly composition of the sewage of any 
 -town can only be determined by the analysis indicated above, carried on 
 through every day of the year, and, by combining these analyses according to 
 the daily volumes of sewage they represent, in the same way as for the daily 
 ■average. In practice, however, all that it is generally necessary to know is 
 the average composition of the dry-weather flow of sewage. 
 
 Owing to the labour involved, calculations of the average composition of 
 sewage as above have been little, if at all, made. The hourly variations in 
 the strength of town sewage must more especially be borne in mind when it 
 is necessary to determine the purity of a sewage effluent from a purifying 
 process such as that of precipitation. For it is plain that if the samples of 
 effluent and sewage are taken at the same time of day, the effluent does not 
 represent, for it is not derived from the sewage arriving at the works at that 
 ;precise period, but is derived from sewage arriving at the works several hours 
 
856 
 
 HYGIENE 
 
 before, which may have been night sewage, and therefore Uttle but subsoil' 
 water. 
 
 The chief valuable ingredients of sewage are the different forms of combined 
 nitrogen, the phosphates, and the salts of potassium. The Rivers Pollution 
 Commissioners gave the money value of these constituents dissolced in 100 
 tons of average sewage of the composition given above as being about 
 15s., whilst the suspended matters contain only about 2s. worth of them; 
 total value, therefore, 17s. This gives a value to the sewage of a fraction 
 over 2d. per ton. It has already been shown that the annual excretal refuse 
 of an individual of a mixed population may be taken as being equivalent to 
 10 lbs. of ammonia, worth 6s. M. ; and this refuse, if diluted with water to 
 form forty tons of sewage (corresponding to an average dilution of 24 gallons 
 per head daily, which is the average dilution of the dry-weather sewage in 
 London), will also give a value to the sewage of Id. per ton. These values- 
 decrease with increasing dilution, until when this amounts to 122| gallons- 
 per head daily (or 200 tons per head per annum) the theoretical value of 
 the sewage is only |(Z. per ton. This is an amount of dilution not infrequent 
 in London during periods of very wet weather. Sewage of the composition 
 given by the Rivers Pollution Commissioners contains about 117 parts of 
 total solid matters (in solution and in suspension) per 100,000. It therefore 
 follows that 855 tons of this sewage contain one ton of solid matters, and 
 the ammonia in one ton of these solids amounts to 179 lbs., worth 5Z. 4s. 5d. 
 at Id. per lb., the remaining valuable ingredients being worth 2^. Os. lld.y 
 or the value of the whole 11. 5s. id. 
 
 We have already alluded to the character of the sewage in the midden or 
 non-water-closeted towns, and sho-svii that in composition it does not differ in 
 any very material respects from that of the water-closeted towns (see p. 854). 
 The Rivers Pollution Commissioners gave the following as the average com- 
 position of midden town sewage : — 
 
 In 100,000 parts. 
 
 Suspended Matters 39-11 
 
 Solids in Solution 82-4 
 
 Organic 
 
 Mineral 
 
 Organic 
 Carbon 
 
 Organic 
 Nitrogen 
 
 Ammonia 
 
 Nitrogen as 
 Nitrates 
 
 TotalCombined ' , , . 
 Nitrogen j Chlonne 
 
 21-3 
 
 17-81 
 
 4-181 
 
 1-975 
 
 5-435 
 
 
 
 6-451 1 11-54 
 
 On comparing this analysis with that of the water-closet sewage, it will 
 be seen that the suspended matters are somewhat less in amount, whilst the 
 solids in solution are greater. The total combined nitrogen is also below 
 that of the water-closet sewage, but the chlorine is in excess, more persons 
 contributing to a given volume of sewage in midden towns than in water- 
 closet towns, owing to the absence of the water used in flushing the closets 
 of the latter. 
 
 Nearly all the processes for purifying and utilising sewage fall under two 
 heads, \'iz. those in which an attempt is made to separate the polluting 
 — which are also the manurial — ingredients of the sewage from the water, 
 which is the vehicle for their conveyance, and those in wliich the sewage is 
 conveyed directly to and disposed of on land. In the first class may be con- 
 sidered those processes of straining, subsidence, and precipitation which 
 aim at removing the suspended matters, at any rate, from the sewage, to be 
 subsequently manipulated into a more or less convenient form for application 
 to land as solid manures, whilst the liquid in a clarified condition is allowed 
 to discharge at once, or after filtration through specially constructed filter 
 
THE DISPOSAL OF REFUSE 857 
 
 beds into the nearest watercourse. This subsequent filtration has been 
 adopted, as we shall see later on, in order that the effluent liquid may attain 
 to some compulsory or otherwise satisfactory standard of purity. 
 
 Steaining, Subsidence, and Pbecipitation 
 
 In some few towns at a former time attempts were made to strain 
 the sewage by passing it through filters constructed of gravel, ashes, or 
 charcoal. The sewage was deprived of its suspended matters, but the filters 
 very rapidly became choked, and had to be renewed at very great cost at 
 frequent intervals. Although the sewage is clarified when the filtering 
 medium is new, it was found that when not renewed with sufficient frequency 
 it became possible for the effluent water to pass away with even more valu- 
 able elements than the raw sewage itself possessed. The manure, too, pro- 
 duced by the retention of the sohd matters in the filter was only usefully 
 employed, owing to its admixture with ashes or charcoal, to mix with and 
 lighten stiff soils. It was not in itself a fertiliser of any but the slightest 
 value. Owing to the great cost incurred in the frequent reconstruction 
 of the filters, and to the fact that the sewage so treated was only clarified, and 
 in no degree deprived of its soluble polluting ingredients, these processes of 
 straining or simple filtration have been everywhere now discontinued. 
 
 When sewage is allowed to settle in tanks, the suspended matters in 
 course of time subside to the bottom, and a more or less clarified liquid can 
 be decanted from the top of the tanks. In this way, then, it is possible to 
 attain quite as good a result as with the filters previously described, and 
 without the inconvenience and cost arising from the periodical renewal of the 
 filtering medium. But the subsidence of the suspended matters in sewage 
 is a slow process, necessitating the provision of large tanks for the sewage to 
 settle in and the expenditure of large sums of money in their construction 
 and in the acquisition of the requisite land. 
 
 It soon came to be recognised that the addition of certain chemical sub- 
 stances to the sewage, when mixed with it prior to its entering the settling 
 tanks, causes a more rapid and copious precipitation of the suspended 
 matters than can be effected by subsidence alone. By such means it was 
 found feasible to reduce the tank accommodation, and at the same time to 
 obtain a more satisfactory effluent. 
 
 The number of chemicals that have been used, or advocated, as precipita- 
 tion agents is enormous. Many of them have proved worthless on practical 
 trial, whilst others, like the various phosphate processes, though shown to be 
 effectual as precipitating materials, depended on what is now known to be 
 the wrong principle of introducing valuable substances into the sewage in 
 the hope of recovering them in the deposited sludge to which they would 
 give a certain fictitious value. Others, again, have been abandoned as 
 being more expensive than certain cheaper substances, whilst not giving any 
 better results. Even to enumerate all these various processes that have 
 at one time or another been tried and then abandoned would be tedious 
 in narration, and unproductive in result, as we are more particularly con- 
 cerned here with those methods that have stood the test of experience and 
 are acknowledged to be, so far as at present known, the best and readiest 
 means of attaining the end desired. 
 
 The three chief substances on which at the present time, in a large 
 majority of instances, is reliance alone placed are lime — as lime water or 
 as milk of lime — suljyJiate of alumina, and j^'t'otosulphate of iron. 
 
 Lime exerts a precipitating effect upon sewage by combining with free 
 
658 HYGIENE 
 
 carbonic acid in the water, and with the partially combined carbonic acid of 
 the bicarbonate of calcium, forming an insoluble carbonate of calcium 
 (chalk) which is deposited ; and this precipitate carries down with it most 
 of the suspended organic matters of the sewage. These substances sink 
 to the bottom of the settling tank, and form the so-called ' sludge ' of 
 sewage. The clear supernatant liquid remains above, and is known as the 
 ' effluent.' 
 
 Lime has been longer in use as a precipitation material than any other 
 substance. Leicester, Tottenham, and Blackburn were among the first 
 towns to adopt the lime treatment of sewage. Until recently it was generally 
 iised as cream or milk of lime (lime slaked and mixed with water) in the 
 proportion of some fifteen grains of the lime to the gallon of sewage. Within 
 the last few years lime water (lime dissolved in water) has been recommended 
 as being equally efficacious with a proportionally less quantity to the gallon 
 -of sewage — viz. five grains instead of fifteen. 
 
 There can be no doubt that the lime process, when worked under the 
 proper conditions of a sufficient quantity of the precipitant intimately mixed 
 with the sewage, and of adequate tank accommodation for settling, can be 
 made to effect a very complete deposition of the suspended matters of the 
 sewage, and that thei-eby it is possible to remove the grosser sewage odour 
 fi'om the effluent. The treatment has, however, very little, if any, efiect in 
 precipitatmg the organic matters in solution, and the ammonia likewise 
 remains unaffected, so that the effluent water carries with it nearly all the 
 valuable manunal ingredients of the sewage, and the sludge left at the bottom 
 of the tanks is comparatively worthless. If the hme is used in too great a 
 quantity, the sludge and effluent are rendered distinctly alkaline, and the 
 tendency to secondary fermentation and decomposition is much promoted. 
 It seems also that the use of an excessive quantity of lime, while affording a 
 rapid settlement of the sludge and a very clear effluent, dissolves a consi- 
 derable quantity of the offensive matters previously in suspension, and thus 
 renders the effluent stronger and fouler than it need be. This constitutes 
 the great drawback to the use of lime alone in the treatment of sewage, as 
 it is of the greatest importance that the effluent should be discharged in as 
 fresh a condition as possible, and that the sludge should not putrefy whilst 
 •collected in pits prior to pressing or drying. There is, besides, a tendency 
 when the sludge is alkaline for it to lose what little ammonia it may possess 
 in the process of drying. 
 
 The precipitation effected by sulphate of alumina is due to its combina- 
 tion with lime or carbonate of calcium in the alkaline sewage to form sulphate 
 of calcium, whilst the aluminium hydrate is precipitated in a flocculent state, 
 entangling and carrying down much of the suspended organic matters, whilst 
 some slight portion of the soluble organic matters is also thrown down. 
 In some cases as much as 5 per cent, of these soluble matters may be 
 deposited with the rest of the precipitate. In other respects the effect pro- 
 duced is very much the same as that resulting from the lime treatment ; that 
 is to say, the sewage is clarified, but still contains the greater portion of 
 its polluting and nearly all its valuable manurial ingredients. The crude 
 sulphate of alumina, however, which is generally used being somewhat acid, 
 the sludge and effluent are neutral or even faintly acid. There is, therefore, 
 less proneness to decomposition than is the case with the alkaline sewage 
 sludge and effluent resulting from the lime process, and in this important 
 respect sulphate of alumina is undoubtedly superior to lime. But there is the 
 drawback that an acid effluent is harmful to vegetation, and therefore is less 
 suitable as an irrigating liquid for land than an alkaline effluent ; and, as we 
 
THE DISPOSAL OF REFUSE 859 
 
 .shall presently see, inasmuch as the clarified sewage from a precipitation 
 process can be very effectually purified on a very small area of land, this is a 
 practice which is coming much into fa-vour. 
 
 Lime and sulphate of alumina have been nscd togetlier at various towns 
 in this country — for instance, at Coventry and Hertford, to cite well-known 
 examples— and, on the whole, these two agents are still generally recognised 
 .as practically the best precipitation agents when used in combination. The 
 proportions in which they are employed should be such as to render the 
 
 • efauent as nearly neutral as possible. Where sewage of medium strength is 
 to be treated, the quantity of lime used may be from five to seven grains per 
 gallon, and of sulphate of alumina about five grains per gallon of sewage. 
 It is, perhaps, hardly necessary to add that when used in combination the 
 
 • effect of these salts upon the sewage does not very materially differ from the 
 
 ■ effect that would be produced by an equal quantity of either. The matters 
 in solution in the sewage are but little affected by any chemical precipitant, or 
 
 • combination of precipitants, yet discovered. The special advantage of the 
 ■combination of lime and sulphate of alumina is the production of a neutral 
 
 ■ effluent and sludge. 
 
 Protosulphate of iron is used as a precipitating material by itself or as an 
 adjunct to lime. It is essential that the sewage with which it is mixed 
 should be alkaline ; hence its frequent use in combination with lime. When 
 so used, it forms a highly flocculent hydrated protoxide of iron, which, in 
 falling to the bottom of the settling tank, carries the suspended matters of 
 the sewage with it. According to Dr. Stevenson, this protoxide of iron acts 
 as a carrier of oxygen, absorbing free oxygen and again giving it up to 
 > organic matters, just as the red blood pigment absorbs oxygen to again give 
 it to the effete tissues. It therefore has a distinct purifying action on 
 sewage by oxidation of organic matters when used in sufficient quantities. 
 It also has considerable antiseptic properties, and tends to prevent the occur- 
 rence of putrefactive processes in the sludge and effluent. By the use of 
 protosulphate of iron, however, the mud banks of the stream into which the 
 ■effluent is discharged become blackened, owing to the formation of sulphide 
 
 ■ of iron. This is a disadvantage from a sentimental, but not from a sanitary, 
 point of view. 
 
 Protosulphate of iron has been but little used alone as a precipitating 
 agent. When used as an adjunct to the lime treatment it should be em- 
 ployed in about the proportion of from three to five grains per gallon of 
 ; sewage. Mr. Dibdin, in the course of some experiments on the metropolitan 
 sewage, found that on some occasions, especially on Saturdays, lime would 
 -not precipitate the sewage completely, a heavy scum rising to the surface, 
 which was carried down on adding a little iron. This result he attributed 
 to the unusually large amount of soap used on Saturdays for washmg pur- 
 poses. 
 
 The effect of the precipitants used on the sludge must be considered, as 
 well as their ability to produce a well-clarified effluent. Sulphate of alumina 
 is said to increase the bulk of the sludge, owing to the fact that alumina 
 
 ■ carries down with it a good deal of water, but the sludge is more easily pressed 
 into cakes than when lime and iron are used. Precipitation by lime and iron, 
 however, is more rapid than by any other process, and the iron tends to pro- 
 duce a dense sludge. It is very often the practice to add some hme to the 
 wet sludge before pressing, even when hme is used to precipitate the sewage, 
 ■in order to secure a coherent cake. What should be aimed at is to procure 
 rapid precipitation of a sludge of but little bulk, which can be subsequently 
 
 -^easily pressed into cakes. 
 
8G0 HYGIENE 
 
 It is probable that a combination of the three materials we have been 
 eonsidering is capable of producing the most highly clarified effluent, and,, 
 at the same time, a sludge which is most easily dealt with. The lime and. 
 sulphate of alumina should be used in about equal proportions, viz. about 
 four or five grains to the gallon of sewage, whilst the iron may be less (about 
 two or three grains to the gallon). It is certainly advisable that the whole- 
 quantity of chemicals used should not exceed fifteen grains to the gallon. 
 The question of cost is, however, of much importance in considering this 
 matter, for, inasmuch as the best chemical process cannot purify sewage, but 
 only clarify it, it is almost always highly desirable that the effluent from a pre- 
 cipitation process should be further purified by filtration through specially 
 prepared areas of land or other suitable filtering material. In such cases 
 all that is required of the precipitation process is that it should precipitate 
 the suspended matters of the sewage in a fairly effectual manner, and should 
 do this at the least possible cost. The removal of the suspended matters is 
 essential for the proper working of the filter beds, but the precipitation of 
 organic matters in solution is not required, as these will be purified in the 
 subsequent process of filtration. The cost of lime is about 11., of protosul- 
 phate of iron 21. , and of sulphate of alumina 31. per ton. It is evident, 
 therefore, that the lime and iron process is somewhat less expensive than 
 lime and sulphate of alumina, and that lime alone is likely to be the cheapest. 
 The only disadvantage of the lime process is the alkaline sludge ; but if this 
 is pressed, no nuisance need arise, so that in those cases where the effluent is. 
 purified by filtration, treatment by lime alone is capable of doing satisfactorily 
 all that is required, and at the least cost. 
 
 The lime process is especially adapted for the preliminary treatment of 
 the sewage of those manufacturing towns where free acids and acid salts or 
 metals in solution are discharged into the sewers with the waste waters of 
 factories. If lime is used these matters are, to a great extent, precipitated, 
 the acidity is neutralised, and the effluent sewage can be used to irrigate 
 land growing crops. This is the process adopted at Birmingham, where the- 
 sewage contains immense quantities of ' pickling liquor ; ' milk of lime, in the- 
 proportion of fifteen grains to the gallon, is mixed with the sewage prior to 
 its entering the settling tanks. 
 
 Amongst other materials used in combination with lime, iron, or sulphate 
 of alumina may be mentioned clay, which is ground very fine, and subse- 
 quently mixed with the other precipitants, before being introduced into the 
 sewage. It acts as a weighting material, causing a rapid deposition of the 
 suspended matters, its effect being chiefly mechanical. It, however, con- 
 siderably increases the weight of the sludge to be dealt with, and for this 
 reason its use is in no great favour. 
 
 Animal charcoal and various forms of prepared carbon have also been 
 tried for their deodorant properties, but it is doubtful if the benefit to be 
 derived is equivalent to the enhanced cost introduced by such expensive re- 
 agents. 
 
 To ensure the most complete clarification of the sewage the following 
 conditions must be fulfilled : — The sewage to be treated must be fi'esh and 
 undecomposed, and the larger solid matters should be removed from it by 
 means of a Latham's extractor before the admixture of the chemicals, or by 
 straining the sewage through a metallic sieve with fine meshes. The 
 chemicals must be added to the sewage before it arrives at the tanks, and at. 
 a spot a short distance from them, so that in its flow along the channel the 
 sewage and chemicals become well mixed together. The admixture may 
 also be accomplished by stirring up the liquid with rotatory beaters. There 
 
THE DISPOSAL OF BEFUSE 8G1 
 
 must be sufficient tank accommodation. The tanks are best arranged in 
 series, so that the sewage may pass through two, three, or four tanks, according 
 to circumstances. A double set should be provided, in order that the treat- 
 ment of the sewage may continue at all times. The sludge must be removed 
 frequently, but, of course, sufficient time must be given for it to settle in 
 the tanks. If allowed to remain too long it will putrefy and give rise to 
 nuisance. When emptied, the tanks must be thoroughly cleansed before . 
 being refilled. When the clarified effluent is discharged direct into a stream, 
 it should be made to flow in a broad but thin stream down a rapid incline, 
 and fall over a weir so as to secure its aeration ; and with the same view 
 the effluent channel should be at least a quarter of a mile in length, and 
 kept scrupulously clean. 
 
 In most modern works the tanks are constructed and managed somewhat 
 as follows : Each tank is from 4 to 6 feet in depth, and is divided nearly into 
 two by a vertical brick partition parallel to its longest sides, round which 
 partition the sewage flows. At the outlet of each tank should be built a 
 weir, not more than half an inch below the surface of the sewage, over which 
 the effluent flows into the next tank of the series, or into the effluent 
 channel. Under ordinary circumstances the sewage need only pass— very 
 slowly, but continuously — through a series of two tanks before the effluent 
 is discharged. Intermittent precipitation, i.e. allowing the sewage a short 
 period of complete rest in the tanks, has been tried, but does not seem to 
 produce a better effluent than can be obtained by continuous working ; and 
 it requires, besides, greater care in management. After from one to ten 
 ■days of continuous working, the flow of sewage through the series should 
 be discontinued, and the sludge allowed to settle, the clear liquid above 
 Ijeing drawn ofl" through the open mouths of float valves into the effluent 
 channel. The residuum of sludge is then allowed to settle, and finally 
 pumped into a sludge well, from which it can be forced up in pipes to the 
 filter presses. 
 
 This sludge contains from 90 to 95 per cent, of moisture. It was formerly 
 the custom to allow it to dry by exposure to the air in pits, but this method 
 was productive of much nuisance during the process of drying, so that it is 
 now the usual practice to press part of the moisture out of the sludge in 
 filter presses actuated by compressed air, by which a solid cake containing 
 from 50 to 60 per cent, of moisture is produced. 
 
 Johnson's filter press, or that made by Manlove, Alliott, Fryer, and Co. 
 (fig. 182), may be taken, as a type of these machines. It consists of a number 
 of grooved discs arranged in series, each disc having a central perforation, 
 and separated from the disc on each side of it by a filtering cloth. The liquid 
 sludge is forced between the discs by compressed air at a pressure of 100 to 
 120 lbs. per square inch ; the liquid, being forced through the filter cloths 
 and along the grooves on the discs, escapes, whilst the soUd portions remain 
 behind between the discs, to be subsequently removed as sohd cakes. The 
 expressed liquid is clear, but exceedingly rich in dissolved organic matters, and 
 very ofl'ensive, and is therefore passed back into the outfall sewer to undergo 
 treatment with the crude sewage, or, better, again separately treated. 
 
 The cakes taken from the filter press can be stored without causing any 
 nuisance, until they can be sold or removed from the works. Or they can 
 be further dried in steam-drying cylinders, and then ground into a powder 
 containing about 20 per cent, of moisture. In this dried granular condition 
 the manure is far more suitable for application to land than in the form of 
 the moist and coherent cakes which issue from the filter presses. 
 
 The weight of sludge cake prodiiced from a known quantity of sludge 
 
862 
 
 HYGIENE 
 
 X = 
 
 taken from the tanks can be calculated from Professor Robinson's formula, 
 
 10 W 
 100 -P' 
 
 ■where W= weight of sludge from the tanks, P= percentage of moisture 
 remaining in the pressed sludge, and X= weight of sludge cake produced. 
 Mr. Dibdin gives the average composition of pressed sludge cake from 
 
 the metropolitan sewage (lime and iron process) as : moisture, 68 per 
 cent. ; organic matter, 16'7 per cent. ; mineral matter, 25*25 per cent. ; 
 ammonia, 1 per cent. ; phosphate of lime, 1'44 per cent. On the cal- 
 culation of its ammonia being worth Id. per pound, the theoretical value 
 of a ton of this sludge cake is 17s. The suspended matters from about 
 
THE DISPOSAL OF BEFUSE 8C8 
 
 850 tons of sewage will be required to produce a ton of sludge cake 
 containing 50 to 60 per cent, of moisture, so that on the supposition of 
 the suspended matters in 100 tons of sewage being worth 2s. (see p. 856),. 
 we also see that the theoretical value of a ton of this sludge cake is 175. 
 Practically, however, this material is almost worthless, being so little suitable 
 in its coherent form for a manure. It therefore usually has to be given away, 
 or even the farmers may want a small premium for removing it. 
 
 As to the value of the more completely desiccated manures produced by 
 a process of artificially drying the sewage sludge cakes, we may quote from 
 a report of a very high authority, the late Dr. Voelcker, F.R.S., on the 
 * Fertilising and Commercial Value of Sewage and Night-soil Manures,' 
 contained in the Report of the Committee of the Local Government Board 
 on Modes of Treating Town Sewage (1876). 
 
 The theoretical or estimated money values of the manures were calculated 
 from the quantities of the following constituents in each, namely, insoluble 
 phosphate of calcium at Id. per lb., soluble phosphate of calcium at 2tZ. per lb., 
 potash at 2(^. per lb., and nitrogen calculated as ammonia at Qd. per lb., 
 these being the rates at which these fertilising constituents of manures may 
 be bought in the form of concentrated artificial manures, such as guano, 
 bone-dust, sulphate of ammonium, &c. The practical or market values were 
 calculated as being from one-half to one-third of the theoretical values. The 
 difference represents the greater expense in carriage and application to land 
 of the more bulky and weaker manure, and the less efficacy and value of 
 nitrogen in the form of nitrogenous organic matter, in which shape the 
 nitrogen of sewage manures principally exists, than in the form of ready- 
 made ammonia. For it must not be forgotten that sewage manures contain 
 a large proportion of matters which occur in abundance in all or almost all 
 soils, and which, therefore, having no commercial value, detract from the 
 price by the cost of their carriage and application to the land. 
 
 As a further reason for the low practical value of these manures as com- 
 pared with their theoretical values, Dr. Voelcker cites the case of farmyard 
 manure. The theoretical value of a ton of good farmyard manure is, he 
 says, about 15s. ; but good dung can be bought in many places at 5s. per 
 ton, or one-third its estimated money value ; and practically the highest 
 price which a farmer can afford to pay for good dung, if he has to cart it 
 even a few miles, would not exceed 7s. Qd. per ton, one-half its estimated 
 money value. 
 
 Value of One Ton o£ the treated Sewage Sludge 
 
 Theoretical 
 or Estimated 
 Money Value 
 
 Practical or 
 Market Value 
 
 Bolton sludge from the ' M and C ' sewage process, dried 
 
 to contain 15 per cent, of moisture .... 
 Solids drained from sewage before the liming process at 
 
 Bradford, dried to contain 15 per cent, of moisture . 
 Sludge from Bradford sewage works, dried to contain 15 
 
 per cent, of moisture 
 
 Sludge from 'ABC' process at Leeds, dried to contain 
 
 15 per cent, of moisture 
 
 £ s. d. 
 Ill 
 
 19 3 
 
 1 0| 
 16 8| 
 
 s. d. s. d. 
 7 to 10 6 
 6 5 „ 9 6 
 6 8 „ 10 
 5 6 „ 8 4 
 
 In the ' M and C ' process, formerly in use at Bolton-le-Moors, lime, carbon 
 (a waste product of the prussiate of potash manufacture), house-ashes, soda, 
 and perchloride of iron were added to the sewage. 
 
 From Dr. Voelcker's report it appears that ' according to the most reliable- 
 statements the separation of the suspended matters of sewage by precipitation 
 
8G4 HYGIENE 
 
 and jBltration, and the production of one ton of dried sewage deposit, apart 
 from the costs of the precipitation agents which are used, entails an expense 
 of ahout thirty shillings for each ton of portable dried sewage manure.' 
 From the table of values above given it will be seen that, according to Dr. 
 Voelcker's calculations, the cost of manufacture of every one of the manures 
 there given considerably exceeds even its theoretical or estimated money 
 value, to say nothing of its practical or market value. It is possible that at 
 the present time, owing to improvements in machinery, it may be feasible to 
 turn out the dried sewage manure at a somewhat less cost, but in any case 
 it will be seen how hopeless it is to expect that the production of sewage 
 manures will repay the cost of working a precipitation process, far less be the 
 means of realising a profit. 
 
 The moist sludge from the precipitation tanks, which contains from 90 to 
 95 per cent, of moisture, is, of com-se, of even less value than the pressed 
 sludge, and can only be regarded as a waste product which has to be got rid 
 of "\^'ithout nuisance. This is the \aew taken at Ealing, where the moist 
 sludge from the tanks, after losing some of its water by draining, is mixed 
 with about two-thirds its volume of ashes and house refuse and is then 
 burnt in a Destructor furnace. Another method of dealing with it, where 
 land can be made available for the purpose, is that practised at Birmingham. 
 
 The sludge is raised from a well in the floor of the settling tank by 
 revolving buckets, driven by steam, into temporary wooden carriers, along 
 which it flows on to the land. Here it parts with some of its moisture to the 
 air, and is then dug into the soil, which is subsequently planted and cropped 
 for one year. At the expiration of the year the land is steam-ploughed, and 
 kept cropped for two years, being occasionally used as a filter bed for the 
 effluent from the tanks, and when the two years have elapsed it is again used 
 for the reception of the sludge. 
 
 We may mention another method of deahng with the sludge, which 
 presents some points of interest, namely, that invented by General Scott, and 
 known as the ' sewage-cement ' process, which was formerly carried on at 
 Ealing and Birmingham. The sewage was precipitated in the tanks by lime 
 and clay, and the sludge so produced when sufficiently dry was placed in a 
 kiln and burnt by intense heat, the residue being then ground into cement. 
 The great difficulty experienced was to dry the moist sludge with sufficient 
 rapidity, filter presses not having been at that time introduced. By the use 
 of modem filter presses the sludge precipitated by General Scott's process 
 would be rendered dry enough to burn into cement, but the process does not 
 appear to have been anywhere in operation in recent years. 
 
 We now come to the consideration of the treatment of the effluent. 
 This we have seen to be merely a clarified sewage ; that is to say, a sewage 
 which is deprived of the whole or of the greater portion of its suspended 
 matters, but still contains all the dissolved organic matters of the sewage. 
 Three main points present themselves for consideration in discussing the 
 advisability of discharging an effluent from precipitation works into a river. 
 First, there is the question of nuisance likely to result ; secondly, the injury 
 to the river if used below the point of discharge as a source of supply for 
 drinking water ; and thirdly, the liability to injure or destroy the fish in the 
 
 river. 
 
 With regard to the question of nuisance it may be stated broadly that no 
 offence is likely to be caused if the effluent is sufficiently clarified and is 
 discharged into a faMy rapid stream, of which the ordinary volume is at least 
 ten times greater than that of the effluent. Under such circumstances the 
 dilution of the foul water with clean is sufficiently great to enable those 
 
THE DISPOSAL OF BEFUSE 865 
 
 processes of self- purification previously alluded to to have free play. There 
 is, however, always the danger of the volume of fresh water in the river 
 undergoing considerable diminution in times of drought ; and at such times, 
 especially in hot summer weather, it is always possible for the foul matters 
 in the effluent to be insufficiently diluted, when they will undergo secondary 
 fermentation ; the river water becomes turbid, and in its bed a deposit of foul 
 organic matters forms, Avliich putrefies and gives rise to offensive gases. The 
 silt thus formed tends to choke up the bed of the stream, and has to be 
 removed at considerable expense by dredging operations. It therefore appears 
 to be advisable that where streams are of very variable volume, according to 
 the season of the year, the clarified effluent should be further purified before 
 being permitted to enter them. 
 
 As regards the second point, it is now universally acknowledged to be un- 
 safe, or at least inadvisable, to use a river as a source of water supply which 
 has at any time received sewage or sewage effluents higher up in its course. 
 Whether the sewage can be sufficiently purified by filtration through earth 
 or other filtering materials to render the river into which it is ultimately dis- 
 charged a safe source for drinking water is a point upon which no very reli- 
 able evidence is at present forthcoming. 
 
 On the subject of injury to fish Mr. Wilhs-Bund, Chairman of the Severn 
 Fishery Board, contributed a very valuable paper to the Congress of the 
 Sanitary Institute at Worcester, 1889. He divides the rivers of this country 
 into four classes, viz. A. Rivers not containing fish. B. Rivers containing 
 coarse fish — CyprinidcB — only. C. Rivers containing coarse fish — Gyprinidcz 
 and non-migratory SalmonidcB. D. Rivers containing migratory Salmonida. 
 The coarse fish — the Cyprinidce — are not injured to anything like the same 
 extent .by sewage in rivers as are the Salmonida. Of the coarse fish the 
 hardiest are the carp and tench, and then, in a series of decreasing hardiness, 
 roach, chub, dace, bleak, gudgeon, and minnow. Many of these fish, as is 
 well known, habitually frequent the sewer outfalls into a river, and feed upon 
 some of the elements of the sewage, and they will even Hve in a fairly 
 clarified sewage effluent. But in the case of polluted rivers Mr. Willis- 
 Bund points out that it is not merely a question of the fish being destroyed, 
 but of how far the pollution affects their numbers and their size by inter- 
 fering with their breeding and destroying their food, or by introducing into 
 their water unwholesome food. There is great reason to beheve that,, 
 although in many polluted rivers the coarser fish have not been to any 
 great extent destroyed, yet they have had their numbers and the size of the 
 individual fish seriously reduced. 
 
 The SalmonidcB, on the other hand, will only live in water that is practi- 
 cally pure, and they are besides of far greater value than the CyprinidcB. 
 And here, again, as regards the migratory species, the salmon, it is not so 
 much a question of the actual poisoning of the fish by noxious sewage 
 matters as of the hindrance offered by polluted reaches of a river to the 
 passage of the salmon from the sea to their spawning beds in the river. 
 If the pollution is sufficiently concentrated the salmon will not pass it, and 
 being obliged to spawn in unsuitable places they gradually become extinct. 
 Where sewage precipitation works are being projected on the banks of a 
 salmon river, it will be necessary to secure a very pure effluent, otherwise 
 the fish will be forced back, for the concentration of sewage matters is very 
 considerable in the reaches of the river in the immediate neighbourhood of 
 such works. Mr. Willis-Bund therefore suggests that for each of the classes 
 of river A, B, C, and D a minimum standard of purity of sewage effluent 
 should be agreed upon, and the Local Government Board should be induced 
 
 VOL. I. 3 k 
 
8G6 HYGIENE 
 
 not to sanction any scheme for sewage works on such rivers the efifluent from 
 which did not come within the agreed standard. 
 
 The clarified eiHuent from a precipitation process can only be effectually 
 purified by some method of filtration. Where land of good quality can be 
 obtained adjoining the works, the process of intermittent downward filtra- 
 tion through specially prepared soil can be adopted with the best results ; 
 and this we shall consider subsequently. Where such land is not obtainable, 
 filtration through magnetic oxide and carbide of iron can be made to give 
 good results. A process of this nature is now in use at Acton and Hendon. 
 The filtering material used is called ' polarite,' and contains about 50 per cent, 
 of magnetic oxide and carbide of iron, combined with sihca, lime, and alumina 
 in an insoluble form. The filter beds consist of 18 inches to 2 feet of polarite, 
 upon which rests a layer of sand about a foot in depth. The sewage is pre- 
 cipitated in tanks with a substance called ' ferrozone,' consisting largely of 
 protosulphate of iron, and the efliuent is then passed through the filter of 
 polarite. The sand separates any suspended matter remaining in the efiluent, 
 and the organic matters in solution are to a very considerable extent oxidised 
 when brought into contact with the polarite, as shown by the presence of 
 nitrates and nitrites in the filtered water, which is moreover clear and colour- 
 less, and far freer from organic matters than the unfiltered effluent. The 
 sand requires renewal from time to time, but the polarite can be left un- 
 changed for very long periods, only requiring a daily rest for aeration of its 
 pores. The slower the filtration — that is to say, the longer the efiluent liquid 
 remains in contact with the pores of the polarite — the greater is the purifying 
 effect produced. It is said that such a filter bed can serve in place of a 
 much larger area of land, and will produce an equally good result, one acre 
 of filter bed being sufficient to purify from one to two milhon gallons of 
 clarified sewage daily. 
 
 Spencer's magnetic carbide of iron has also been tried as a filtering 
 material for sewage effluents, and gives very similar results. In fact, the two 
 materials are probably very similar in nature and composition. We have 
 here, then, a means by which without great expense and without acquiring 
 any large area of land sewage can be, with care and attention, sufficiently 
 purified to be rendered admissible into almost any stream, no matter what 
 the original purity of its waters. It is important to note, however, that in 
 these processes all the manurial ingredients of the sewage run to waste ; for 
 we can hardly regard the dried sludge as a valuable product, it being practi- 
 cally unsaleable, and the efiluent water containing all the valuable matters 
 is not made of any account, for none of these matters can be recovered from 
 the filter beds, inasmuch as they are destroyed in the process of oxidation. 
 
 At this place it wiU be convenient to consider very shortly some of the 
 more important patented processes for the treatment of sewage by precipi- 
 tation. 
 
 The 'ABC' process (Sillar's patent) has been tried at Leamington, 
 Leeds, Bolton, Crossness, and other towns, and is now in actual operation at 
 Aylesbury and Kingston-on-Thames, being carried on by the Native Guano 
 Company. A mixture of charcoal, clay, and blood (in very small quantity) 
 is first mixed with the sewage, after which is added crude sulphate of 
 alumina. A compound of manganese and some other ingredients were 
 formerly added as well, but we beUeve these are not now introduced. A 
 highly clarified effluent is produced by the process, which is, however, a 
 costly one. The sludge is pressed in filter presses and subsequently dried in 
 steam cylinders, and sold as a granular manure containing about 20 per cent, 
 of moisture. The Company claim that this manure sells for 31. 10s. per ton. 
 
THE DISPOSAL OF BEFUSE 867 
 
 It is difificult to understand how mere dried sewage sludge can command so 
 large a price, as it is certain that it cannot contain sufficient ammonia and 
 phosphates to justify any such value. We have seen, too, what value the late 
 Dr. Voelcker placed upon the dried 'ABC' sludge obtained from the sewage 
 of Leeds (see p. 863). But the advocates of the process rely upon the practical 
 results obtained by agriculturists from its use, rather than upon theoretical 
 values based upon analytical data. Until these practical results obtained in 
 the hands of farmers are published — and they are not at present — we are 
 not in a position to discuss the question ; but we are of opinion that some 
 other explanation is called for than that offered by Mr. Sillar to the Royal 
 Commission on Metropolitan Sewage Discharge, viz. * that this sewage 
 manure is the natural substance which was intended to manure the earth, 
 and that the earth has a natural liking for it, independently of its actual 
 ammonia or phosphate strength.' 
 
 At various times substances which act as deodorants or antiseptics have 
 been used in combination with the chemical precipitants. These have mostly 
 met with failure, partly on account of the expense involved in any attempt 
 to deodorise large volumes of sewage with antiseptic compounds of high 
 price, and partly owing to the fact that the antiseptic substances tended to 
 escape with the effluent water, and to poison the fish of the river into which 
 it was discharged. 
 
 The most successful of these processes appears to be the one invented by 
 Hanson, which has been in operation at Tottenham and Leyton. At these 
 places the sewage is treated with lime in the ordinary v^^ay and with black- 
 ash waste (about four grains to the gallon of sewage). Crude black-ash 
 waste is a refuse of alkali works, and is prepared and sold in London, in 
 a granular condition suitable for mixing with sewage, at 8L IO5. per ton. 
 This substance contains about 30 per cent, of the sulphites and hyposulphites 
 of calcium, which are powerful reducing or deoxidising agents, and impart to 
 the waste considerable antiseptic and deodorising properties. They are not 
 present in new black-ash waste, but are formed in the heaps of this material 
 which have been long exposed to the air by the oxidation of sulphide of 
 calcium. Some of the hyposulphite of calcium passes off in the effluent, 
 as it is soluble in water. The adoption of the process at Tottenham and 
 Leyton was followed by a great improvement in the condition of the river 
 Lea, which had been very much polluted with sewage. Besides its deodorant 
 properties, black-ash waste appears to prevent the formation of putrefactive 
 bacterial organisms in the effluent, but it does not interfere with the growth 
 of those microscopic organisms (infusoria, anguilluhdge, &c.) which, by feed- 
 ing on organic matters, are capable of purifying foul waters, without the 
 production of foul gases from putrefaction. 
 
 Mr. Dibdin, chemist to the late Metropolitan Board of Works, recommended 
 the addition of manganate of sodium and sulphuric acid to chemically treated 
 sewage. These substances, when used together, liberate oxygen, which tends 
 to deodorise the sewage ; but it is evident that the amount of such an oxi- 
 dising agent which would be required must be very large to produce any 
 appreciable result, and so the expense would be prohibitory. 
 
 The latest of these deodorising methods is that known as the Amines 
 process, which has been tried experimentally at the Wimbledon Sewage Works 
 and at Canning Town. The sewage is treated with milk of lime and with a 
 small quantity of herring-brine, which contains a certain percentage of the 
 compound ammonia, methylamine. This subtance when brought into con- 
 tact with lime is said to give off a gas termed ' aminol,' which spreads rapidly 
 through the sewage, and is a powerful antiseptic and deodorant. When 
 
 3 k2 
 
868 HYGIENE 
 
 efficiently carried out, the process is said to effect a complete sterilisatiou of 
 the effluent, all micro-organisms being destroyed, so that it (the effluent) 
 imdergoes no secondary fermentation even when kept at a high temperature 
 in contact with the air. The sludge, too, is deodorised, or at least gives off 
 only a briny smell, as well as the effluent, and it can be dried in pits exposed 
 to the air, or on the floor of a drying kiln, without giving rise to any nuisance. 
 Such being the case, the process of pressing in filter presses is rendered 
 unnecessary, and a considerable source of outlay is thereby avoided. It will 
 not serve any useful purpose to discuss the process in its present experi- 
 mental stage, but it may be observed that the herring-brine is at present a 
 cheap commodity ; and it is evident that the use of deodorants and anti- 
 septics as auxiliaries to precipitation processes must be advantageous if they 
 retard decomposition without interfering with oxidation by natural agencies, 
 and without injury to fish, and if at the same time they involve but little 
 extra cost. 
 
 We have recently had an opportunity of seeing the Amines process at 
 work at the Wimbledon Sewage Works and Farm. As recommended by the 
 inventor of the process, the quantity of cream of lime used is very large, 
 viz. about seventy grains to the gallon. The lime is mixed Avith the herring- 
 brine before being introduced into the sewage. With this large quantity of 
 lime the precipitation is very rapid, and after the clarified effluent is run 
 off' from the tanks, the sludge settled at the bottom may again be used as 
 the precipitation agent, no chemicals being then added to the sewage. As 
 the sewage flows into the tanks it stirs up the sludge, which becomes inti- 
 mately mixed with it. The sludge may in this manner be used several times 
 in succession before it is needful to add fresh chemicals to the sewage. The 
 sludge, owing to the large quantity of lime it contains, is readily pressed 
 into cakes in the filter presses, and these cakes are sold at Wimbledon at the 
 price of Is. per load (ton). The moist sludge may be dried in pits, without 
 offence, and we inspected some which had been exposed to the air for some 
 months in a pit, without, as we were informed, having at any time caused 
 any offence in the process of drying. 
 
 A process of precipitating sewage by electrolysis has been tried at 
 Crossness on the metropolitan sewage, and also at Bradford, in Yorkshire, in 
 both cases merely as an experiment. The system is the invention of Mr. 
 William Webster. The process, as experimentally tried at Bradford, is 
 described by Dr. James MacLintock, Medical Officer of Health of the borough, 
 in a paper read before the Public Medicine Section of the British Medical 
 Association Congress at Birmingham, 1890 (' British Medical Journal,' 
 Aug. 30, 1890). There is a very large proportion of manufacturing refuse 
 in the sewage of Bradford, viz. dyes, acids, alkalies, grease, and other 
 organic matters (wool washings) from the mills, the greater majority of which 
 are engaged in the woollen industry. The large proportion of mill waste 
 waters in the sewage renders it very difficult to obtain a satisfactory 
 effluent with the lime process of precipitation, which is the one by which the 
 bulk of the sewage at Bradford is at the present time treated. 
 
 The description of the electrical process is thus given by Dr. Mac- 
 Lintock : — 
 
 ' The plant necessary for the electrical treatment is as follows : — (1) An 
 electrolytic shoot or channel; (2) an electric generator; (3) motive power 
 for generator ; (4) necessary conductors for conveying the current to the 
 shoot from the generator ; instruments for measuring the current used and 
 the potential at which it is supphed. The electrolytic shoot, constructed of 
 brickwork, is 25 feet in length, 24| inches wide, and 4 feet in depth. It is 
 
THE DISPOSAL OF BEFUSE 
 
 869 
 
 divided into eighteen cells, each of which contains twenty iron plates, mea- 
 suring 3 feet X 1 ft. 2 in. x \ in., and weighing on an average 70 lbs. each. 
 
 ' These plates are placed vertically in the shoot, and present their edges to 
 the direction of flow of the sewage. The cells are divided one from the 
 other by partitions so arranged that the sewage in traversing the shoot 
 passes alternately under and over them. Every alternate plate is connected 
 respectively with the positive and negative poles of the generator. All the 
 plates in each cell are connected up in parallel, and the cells are connected 
 in series one with the other. The generator is a dynamo by Mather and 
 Piatt, of Manchester, capable of developing 100 volts and 180 amperes, but 
 for this plant the full output of the machine is not required. The motive 
 power is supplied from shafting in connection with a steam engine belonging 
 to the Corporation. The raw sewage first enters the shoot, and passes into 
 a settling tank, and then enters another shoot similar to the one described, 
 except that it possesses eight cells instead of eighteen, and from there flows 
 rapidly into three small tanks, and thence along a channel into the stream. 
 During the process a greasy scum collects on the surface of the tanks and on 
 the iron plates in the shoot. This is collected into a small tank partitioned 
 off for the purpose. 
 
 ' It is at once seen that the sewage is undergoing a change during its 
 passage along the electrolytic shoot. Gas is disengaged, the fluid is chang- 
 ing colour to a slight degree, assuming a greenish hue ; and, most impor- 
 tant of all, a flocculent precipitate is being rapidly formed. In the first 
 settling tank the greater part of this precipitate settles as sludge. The 
 rest of the sewage flows into the second shoot, is there subjected to further 
 electrical treatment, and is finally allowed to flow through the different 
 tanks, where a further deposit takes place. The effluent flows into a channel 
 where it is still further aerated, and then, as before stated, into the Bradford 
 Beck, which is a tributary of the river Aire.' 
 
 The active precipitating agent formed by the electric current appears to 
 be hydrated ferrous oxide, in a nascent condition, which is continuously 
 being formed, and is used as fast as it is made. The arrangement of the 
 plates and cells insures the most intimate and thorough mixing of the pre- 
 cipitating agent with the sewage. The continuous formation of the iron 
 oxide, its nascent condition, and the thorough mixing of it with the sewage, 
 are the special features of the process, which render it superior (according to 
 the results hitherto obtained) to the ordinary treatment of sewage with salts 
 of iron. The electrical treatment also possesses another advantage over lime 
 or alumina processes, viz. that it adds very little to the sewage, and there- 
 fore limits the quantity of sludge to the lowest amount consistent with the 
 removal of the suspended solids from the sewage. 
 
 The composition of the Bradford sewage before the electrical treatment, 
 and of the effluent after it, are stated by Dr. MacLintock to be — 
 
 - 
 
 Sewage before 
 Electrical Treatment 
 
 Effluent after 
 Electrical Treatment 
 
 Total solids . . . . . 
 After ignition . . „ . . 
 Loss on ignition . » . . 
 
 Chlorine 
 
 Free ammonia . , . . 
 Albuminoid ammonia 
 
 127 grs. per gal. 
 69 „ „ 
 58 „ „ 
 10 „ „ 
 32 parts per million 
 15 
 
 6*'i grs. per gal. 
 47 „ „ 
 19 „ „ 
 
 9 „ „ 
 21 parts per million 
 
 5 
 
 From the fact that the loss of solids on ignition is reduced from fifty- 
 eight to nineteen grains per gallon, it appears that nearly 70 per cent, of the 
 
870 HYGIENE 
 
 putrescible portion of the sewage is removed by the treatment. The reduc- 
 tion of albuminoid ammonia is also very considerable (G6 per cent.), but the 
 free ammonia is reduced to a less extent. No Hving organisms could be 
 detected in the effluent, although the sewage was crowded with bacteria, 
 infusoria, and other low forms of organic life. 
 
 The effluent is clear, with a slight yellowish-green tinge, and is little 
 hable to undergo secondary putrefaction. 
 
 We may conclude, then, that the experimental trials already conducted 
 show that the process is capable of purifying sewage, and even sewage of 
 bad quality, in a higher degree than can be attained by the ordinary methods 
 of precipitation with lime, iron, or alumina ; but, on the other hand, the 
 cost of the process will probably be found to be far in excess of that required 
 for the latter methods. A large initial outlay is required for dynamos, 
 steam motive power, electrolytic shoots, iron plates, and depositing tanks. 
 The expense of working, too, must be high, owing to the consumption of 
 power, whilst, from the quantity of iron present in the sludge and effluent, it 
 is evident that a considerable amount of iron must be daily consumed and 
 the plates will require frequent renewal. 
 
 To sum up, then, the conclusions at which we may arrive with regard to 
 precipitation processes. They to a certain extent purify the sewage by 
 clarifying it — that is to say, by causing a deposition of the suspended 
 matters in the settling tanks — but they all leave a very large amount of 
 putrescible matter in the effluent water — namely, all, or nearly all, the 
 organic matters which are in solution in the seAvage, and fail to remove any 
 of the ammonia contained in the sewage, which invariably escapes in the 
 efflueut water. It is for this reason that the manures produced from the 
 precipitated sludge are of so inferior a character, for the suspended matters 
 that are precipitated from sewage constitute less than one-sixth of the value 
 of its total fertilising ingredients. Precipitation processes, then, completely 
 f;dl to utilise sewage to any advantage, and they only effect a partial purifi- 
 cation. On the other hand, when employed merely as a preliminary to land 
 treatment, as is now so largely the practice, they are capable of rendering 
 services of great value. 
 
 Land Filtration 
 
 The first experiments on the filtration of sewage through the soil were 
 made by the Elvers Pollution Commissioners about twenty years ago. It 
 was then shown that sewage was capable of being very efficiently purified in 
 its passage through a few feet of porous soil, but that to secure the best 
 results the filtration must be from above downwards, and must be intermit- 
 tent, in order that the pores of the soil may be aerated during the periods of 
 rest. The process of upward filtration was tried, but was found to be inef- 
 ficient in the purification of sewage from soluble offensive matters. 
 
 The purification of sewage by soil is, to a certain extent, due to the soil 
 acting as a mechanical filter, separating and retaining the suspended matters- 
 in -the sewage. But the principal agent is the oxidising power of the soil,, 
 by which ammonia and organic matters in the sewage are converted into 
 nitrates, nitrites, and carbonates. This oxidising power is partly dependent 
 upon the porosity of the soil, by which the particles of sewage are brought 
 into contact with oxygen from the air retained in its pores, but chiefly upon 
 the presence of nitrifying organisms belonging to the family of bacteria. These 
 organisms are found in sewage itself, and are abmidantly present in most 
 soils, but chiefly in those rich surface soils of mould or loam which contain 
 an abundance of organic matters. The experiments and researches of 
 
THE DISPOSAL OF BEFUSE 871 
 
 Schloesing, Mxintz, and Warington have shown that these nitrifying organ- 
 isms (one of which has been isolated by Percy Frankland) feed upon the 
 ammonia and organic matters of sewage, causing their oxidation, and that 
 this nitrification is confined to the same range of temperature which Kmits 
 other kinds of fermentation — that is to say, that the production of nitrates 
 proceeds very slowly near the freezing-point, but increases in rapidity as the 
 temperature rises, reaching its maximum of energy at about 99° F. Other 
 essentials for the proper performance of nitrification are, that the soil be 
 well supplied with air — hence the advantages of porosity in the soil and of 
 intermittent application of the sewage — and also that some base, such as 
 lime, soda, or potash, be present in the soil, with which the nitric acid as 
 formed may combine. Without the presence of this salifiable base it has 
 been found that nitrification will speedily come to a standstill. 
 
 In the choice of a soil, then, for the reception and purification of sewage 
 the following conditions should, if possible, be fulfilled :— The soil should be 
 of a rich loamy character, and therefore well supplied with the nitrifying 
 organisms. It should be porous and composed of small fragments, both to 
 allow of free aeration and oxidation and also so that it may present an 
 immense surface, covered with the organisms, to the sewage while percolating 
 through it. Pure sandy soils are not efficient purifiers until their particles 
 have become coated with the nitrifying organisms present in the sewage, and 
 then they act well. All retentive soils containing an excess of clay must be 
 well broken up and mixed with town ashes or with ballast (burnt clay) ; and in 
 such cases it is advisable to introduce as well a layer of alluvial or other rich 
 soil. 
 
 The surface of the land must then be carefully levelled, to admit of the 
 sewage flowing evenly over every part of it, and it should be under-drained 
 with porous agricultural tile drains laid at a distance of 10 to 30 feet apart, 
 according to the porosity of the soil, and at a depth of 4 or 5 feet from the 
 surface. To lay these under-drains at a greater depth from the surface is 
 now thought to be unnecessary, as the nitrifying organisms are not usually 
 found at a greater distance from the surface than 4 feet, and are almost 
 invariably present in greatest numbers in the first 18 inches of soil. The 
 filtration area should then be laid out in plots, each plot to receive sewage for 
 six hours only every day, so that it may have eighteen hours out of the 
 twenty-four for necessary rest and aeration. 
 
 Where the sewage of a large number of people has to be applied to a small 
 area of land, it is generally advisable to precipitate the suspended matters of 
 the sewage by chemicals as a preliminary process, and to irrigate the land 
 with the clarified sewage effluent only. As a general rule, which, however,, 
 must not be apphed too strictly, it may be stated that where the sewage 
 of more than 1,000 people must be applied to each acre of land, the sewage 
 should undergo a preliminary precipitation ; but if the proportion is less than 
 1,000 to an acre and the land is of suitable quality, the sewage should be 
 allowed to flow on to it as it comes, or after a mere simple straining to remove 
 the larger solid bodies. If the raw sewage is applied in too large volumes 
 to a smaU area of land, the surface of the soil tends to become rapidly clogged 
 with a thin layer of suspended matters and shme, and a coating is formed 
 which prevents the percolation of the sewage and the penetration of air into 
 the interstices of the soil. The slimy matters in sewage are derived from 
 the grease of kitchen waste waters, the fats of soap, the mucus from the 
 urinary and intestinal mucous membranes, and from macerated paper. The 
 land has, therefore, to be constantly raked over, and the surface layers dug 
 up and incorporated with those beneath with much labour and expense ; if 
 
-872 HYGIENE 
 
 this is not done the sewage stagnates and forms ponds on the surface and 
 gives rise to nuisance as soon as decomposition commences. 
 
 This difficulty is entirely avoided by irrigation with clarified sewage only. 
 There are other advantages besides this in adopting precipitation as a 
 preliminary. Most of the bacterial organisms and their spores, the active 
 agents in putrefaction, are carried down in the precipitate, and therefore 
 removed from the eiikient, which is consequently less prone to putrefy and 
 readier to undergo nitrification in the soil, for putrefaction and nitrification 
 are antagonistic processes, just as we have seen putrefaction and oxidation are. 
 It would seem that, as a preliminary to land treatment, lime is the best pre- 
 cipitating material that can be used, as it introduces into the sewage effluent 
 the requisite base for combination with the nitric and nitrous acids formed by 
 nitrification. Lime is also the best material to neutralise the acids and acid 
 salts contained in sewage which has received the waste waters of manufactories 
 and chemical works ; this kind of refuse proving a great hindrance to the 
 purification of sewage by soil. The presence of antiseptics in the sewage also 
 prevents nitrification, so that such deodorising agents as carbolic acid and 
 perchloride of iron, which have been used as adjuncts to the lime process, 
 must not be employed where the clarified sewage is to be applied to land. 
 Whether black-ash waste or herring-brine are sufficiently strong antiseptics 
 to prevent nitrification in the soil has not yet been determined ; as regards 
 black-ash waste, we should be inclined to think that, as it does not prevent 
 oxidation processes and the growth of infusorial life in the effluent, it would 
 not either have any prejudicial effect upon the nitrifying process in the soil. 
 
 It is probable that by intermittent downward filtration through well- 
 drained beds of porous soil of suitable nature, the clarified sewage of as 
 many as 5,000 people (100,000 to 150,000 gallons daily) may be applied to 
 each acre of land without overdosing the soil with sewage or placing too 
 great a strain upon its purifying powers. But as a set-off against the small 
 area of land required to cleanse the sewage must be taken into account the 
 cost of precipitating the sewage and subsequently dealing with the sludge. 
 And it is even now doubtful if it is not better policy for a local authority to 
 acquire a larger extent of land, and to allow the suspended matters to reach 
 the soil by gravitation in the liquid sewage, rather than to incur the cost of 
 separating them by precipitation, and then pumping the liquid sludge on to 
 the land. Mr. Bailey Denton is even of opinion that, if properly distributed 
 on carefully prepared surfaces, sludge on land generally does good rather 
 than harm, and that it is only objectionable when mixed with trade refuse. 
 He advises filtration beds to be laid out in ridges and furrows, the sewage 
 being allowed to flow down the furrows, whilst vegetables (cabbages, roots, 
 &c.) are grown on the ridges. The sewage obtains access to the roots of the 
 vegetables, which assimilate from it ammonia and organic matters, and thus 
 aid the purification. The leaves and stalks being above the sewage are not 
 contaminated by floating matters, and therefore no exception can be taken 
 to their use as articles of diet. The suspended and slimy matters of the 
 crude sewage are deposited in the furrows. Before they have had time to 
 form an impenetrable coating, the sewage must be turned off the plot, and 
 the deposit allowed to dry and shrink, when it is easily broken up and 
 incorporated with the soil. 
 
 When intermittent downward filtration is properly conducted on suitable 
 land, the effluent water issuing from the under-drains is found to be very 
 effectually purified. It will be almost entirely deprived of organic matters 
 and ammonia, and the oxidation to which these have been subjected will be 
 evidenced by the presence of a considerable quantity of nitrates in the 
 
THE DISPOSAL OF REFUSE ^ 873 
 
 ■effluent. In fact, a very large proportion of the nitrogen of the sewage passes 
 away in the effluent water in the innocuous form of nitrates and nitrites. 
 The chlorine, however, will be found in very much the same proportion in 
 the effluent as in the sewage. The purification is usually most complete 
 during the warmer months of the year, when the nitrifying organisms are at 
 a temperature suitable to the display of their most active properties, and 
 when vegetable growth is at a maximum. In winter the purification may 
 be less complete, but not necessarily so, as the oxidising and nitrifying power 
 of a soil may be in excess of the work provided for it, so that even with a low 
 temperature the usual amount of purification may be attained. 
 
 By intermittent downward filtration through small areas of land we see, 
 then, that sewage may be very effectually purified, so that the efiiuent attains 
 a high standard of cleanliness and is admissible into streams of great natural 
 purity. But by this process all the manurial ingredients of the sewage are 
 wasted, except in those cases where the sale of vegetables grown on ridges 
 ■ covers part of the cost of distribution ; and even in these cases, as nearly all 
 the nitrogen of the sewage is found in the effluent water, but little can be 
 abstracted for the growth of produce or for the enrichment of the land 
 The area of land, too, being so very limited, the amount of vegetable produce, 
 and the income derived from its sale, must necessarily be very small. In 
 fact, in the words of the Eeport of the Commission on Metropolitan Sewage 
 Discharge, ' filtration is the concentration of sewage at short intervals on an 
 ■area of specially chosen porous ground as small as will absorb and cleanse 
 it, not excluding vegetation, but making the produce of secondary im- 
 portance.' 
 
 The cost of preparing land as an intermittent filter bed is much greater 
 than that required for broad irrigation on the usual sewage farm plan ; but 
 then the efficiency of each acre in doing the work of purifying sewage is far 
 greater by the former method than by the latter. Mr. B. Denton estimates 
 the average cost of preparing land for a filtration area at about 101. per 
 acre. 
 
 As regards liability to nuisance, this is little likely to arise if the land is 
 properly managed. Where crude sewage is applied to the soil, offence may be 
 caused, as previously stated, by ponding of stagnant sewage owing to the clog- 
 ging of the surface soil with slimy matters. Where the suspended matters 
 are first precipitated, the storage of sludge on the premises or its application 
 to land in a liquid state may give rise to nuisance ; but it may truly be said, 
 with regard to all methods of dealing with such foul waste matters as sewage, 
 that unless ordinary care and attention are bestowed by those in charge the 
 very best method is liable to fail and be productive of niiisance, and therefore 
 that objections raised on this score apply less to the principle of the method 
 pursued than to the manner in which it is carried out. 
 
 Intermittent downward filtration, preceded by a precipitation process for 
 "the removal of the suspended matters, was the method recommended by the 
 Commissioners as offering the best solution of the metropolitan sewage 
 discharge difficulty. The enormous quantity of precipitated sludge is the 
 chief drawback to such a process, but the Commissioners thought it might 
 be got rid of without offence by burning it, carrying it out to sea, digging 
 it into land, or using it for raising low-lying lands at the mouth of the 
 ' Thames. 
 
 lEEIGATION 
 
 Surface or broad irrigation was defined by the Eoyal Commission on 
 "Metropolitan Sewage Discharge to mean ' the distribution of sewage over a 
 
874 HYGIENE 
 
 large surface of ordinary agricultural ground, having in ^•iew a maximum 
 growth of vegetation (consistently with due purification) for the amount of 
 sewage supplied.' 
 
 We have already seen that large volumes of sewage can be very efficiently 
 purified by filtration through small areas of suitable land carefully levelled 
 and under-drained ; but that although the purification is satisfactory, the 
 utilisation of the manurial ingredients of the sewage is but little efl:ected, as 
 the area of land sewaged is too small to raise crops in any quantity, with the 
 result that the nitrogen of the sewage to a large extent escapes in the efduent 
 water in the form of nitrates. If, however, the same volume of sewage be 
 applied to a much larger area of land, it is possible to utilise the sewage by 
 the production of large crops of grass and vegetables, whilst its purification 
 goes on as before. 
 
 It is e\'ident, therefore, that a sewage farm should be an enlarged filtration 
 area. The same forces are concerned in the purification of the sewage as 
 were mentioned under land filtration ; so that on every sewage farm the 
 sewage should be applied intermittently to each field or plot of land ; it should 
 then sink into the soil, so that it may be filtered and oxidised, and finally 
 pass away by means of under-drains into the watercourse which efl'ects the 
 natural drainage of the locality. Any system of irrigation by which the 
 sewage is applied too continuously to the land, or by which it subsequently 
 passes over the surface of the land and not through it, is likely to prove a 
 failure by giving rise to nuisance from a water-logged condition of the soil 
 and from insufficient purification of the effluent. 
 
 We can now consider the conditions under which sewage farming should 
 be conducted, in order to attain a successful result both m the purification of 
 the sewage and in its utihsation as a manure. 
 
 As regards the position of the farm with relation to the town, the sewage 
 of which is to be applied to it, it is most important that the land should lie 
 at such a level that the sewage may flow to it by gravitation. In many 
 instances, however, the choice of land in the vicinity of a town is limited, 
 and recourse has to be had to pumping. The pumping of large volumes of 
 sewage on to a sewage farm is a costly process, and greatly reduces, or even 
 annihilates, any profits that would otherwise arise from the sale of sewage- 
 grown produce ; there is, besides, the very great sanitary disadvantage that 
 the capacity of the pumps may be exceeded at times when the volume of 
 sewage is very large from admission of storm waters into the sewers, and if 
 such is the case the sewage is backed up in the outfall and tributary sewers, 
 leading to flooding of cellars in low-lying districts and deposit of putrid 
 sediment. 
 
 To make sewage farming a profitable undertaking it is, of course, neces- 
 sary that the land should be acquired at a reasonable price, little, if any, in 
 excess of that paid for ordinary agricultural ground in the neighbourhood. 
 In very few instances, however, has this been done. Local authorities have 
 experienced the greatest difficulty in acquiring land for sewage irrigation, and 
 in many cases have given enormous prices for agricultural land required for 
 sewage farms, with the result that this capital expenditure, added to enormous 
 Parliamentary and legal costs, has saddled the local rates with burdens, 
 which for very many years cannot possibly be diminished to any appreciable 
 extent by the sale of sewage-gi'0T\m produce. Where land is rented for sewage 
 irrigation, according to Mr. Bailey Denton, 21. 10s. per acre is a price which 
 should not be exceeded. 
 
 The nature of the soil of a proposed farm is a very important factor. 
 Probably the best kind of soil is a porous and friable loam on a subsoil of 
 
THE DISPOSAL OF REFUSE 875 
 
 gravel. Such a soil forms a very efficient filter for the sewage which readily 
 percolates into it, and it involves the least expenditure in under-drainage. 
 Other porous soils containing considerable admixtures of sand and gravel are 
 also capable of purifying and utilising sewage when properly managed ; but 
 dense clayey soils should, if possible, be avoided, as unless considerable 
 expense is incurred in breaking them up and mixing them with town ashes, 
 and in under-drainage, they prevent the percolation of sewage, which tends to 
 run over the surface and to gain access to the streams in a very insufficiently 
 purified condition, especially in winter, when vegetation is least active. 
 
 The extent of land to be acquired must be dependent upon a variety of 
 circumstances, such as the cost per acre, the nature of the soil, the variation 
 in the volumes of sewage between dry and wet weather flow, and the demands 
 of the local markets for the grass and vegetables produced from it. Perhaps 
 the average may be taken as one acre to every 100 persons of the population ; 
 but it must be clearly understood that no hard-and-fast rule can be laid 
 down. 
 
 The amount of under-drainage required will depend partly on the nature of 
 the soil and partly upon the extent of land upon which sewage can be applied 
 in relation to the whole volume of sewage reaching the farm. Least under- 
 drainage will be required for the lighter kinds of soil resting upon a porous 
 subsoil, and where the area of land is large in proportion to the volume of 
 sewage. For soils of medium consistence, or where the area of land to which 
 sewage is applicable is relatively small, under-drainage must be thoroughly 
 carried out — pipes of porous earthenware 2 inches in diameter being laid 
 at a depth of from 4 to 6 feet from the surface of the soil, and in parallel lines 
 from 20 to 100 feet apart, according to circumstances. These subsidiary 
 drains should eventually be connected at suitable points with arterial drains 
 of larger size which join the main effluent drain or channel that discharges 
 into the stream at the lowest part of the farm. 
 
 The outfall sewer should conduct the sewage to the highest point of the 
 farm, at which spot, before the sewage is allowed to flow over the land, it is 
 generally advisable to screen it through a grid to remove the larger solid 
 matters. From this point the land should fall away gently, so that the 
 sewage may reach every part of the farm by gravitation. Certain portions of 
 the land may, however, require levelling, to ensure the regular and even 
 irrigation which is desirable. The main carriers for the distribution of the 
 sewage should be constructed of masonry or concrete, in the form of open 
 channels, which are easily flushed and cleansed ; or stoneware channel pipes 
 may be used. The subsidiary carriers need be nothing more than grips dug 
 in the land, which can be filled in as soon as they become to any extent 
 clogged with suspended slimy matters, and fresh ones dug in their place. 
 
 For applying the sewage from the main carriers to the surface of the 
 land, the best plan, as a general rule, to adopt is that known as the ridge 
 , and furroio system. The surface of the ground is laid out in broad ridges 
 ' — 30 to 70 or more feet across — running parallel to each other, but at 
 right angles to the main carrier, from which they fall away to a slight 
 extent. Between every two ridges is a longitudinal furrow formed by the 
 slope of the ridges towards each other. The furrow is some few inches 
 (eight or ten) below the level of the centres of the ridges on each side of it. 
 The sewage is applied as follows : A workman stops the flow of sewage in a 
 main carrier by lowering a sluice, or placing a ' stop ' of wood athwart the 
 carrier, opposite the centre of a ridge. The sewage then overflows from the 
 main carrier and passes down a grip in the centre of the ridge, from which 
 it can be made to flow over the sides of the ridge towards the furrow by 
 
876 HYGIENE 
 
 throwing some earth into the central grip or by blocking the passage with a 
 board. After a certain interval the sewage is allowed to flow a little further 
 down the central grip, and then again made to overflow as before, mitil the 
 whole area of land has received its allotted portion of sewage. 
 
 The catchicatcr system has been adopted at farms, such as that at 
 Warwick, where the ground has a very considerable slope from the point of 
 delivery of the sewage. The main carriers are carried across the direction 
 of the slope along contour lines, so as to be more or less parallel to each 
 other one above the other, and the sewage, as it overflows from the highest 
 carrier, passes over the land below, such of it as is not absorbed reaching the 
 carrier next below and again overflowing, and so on to the lowest carrier. 
 The disadvantage of this system is that the higher portion of the land receives 
 too much sewage and the lower gets little else than water. 
 
 Yet another plan is that known as the pane and gutter system, which is 
 in use at the Croydon Sewage Farm, where there is a general very slight fall 
 of the land. It is very similar to the catchwater system, the sewage passing 
 from the main carriers laid across the fields, and spreading over the surface 
 of the beds from above downwards. At the Croydon Farm the soil is rather 
 retentive, so that there is a tendency for the sewage to have a surface flow 
 only, without any large amount of percolation, and to be carried from one field 
 to another imtil it passes away into the brook, with only such an amount of 
 purification as is brought about by its exposure to the air and by the 
 action of vegetation. It may be stated, however, that the sewage is very 
 fairly purified at the Croydon Farm, at any rate in summer, by surface 
 flow, and the efiluent flows into the stream in a clear and colourless condi- 
 tion. The area of land available for irrigation is 500 acres, and as the popu- 
 lation contributing the sewage is 100,000, the sewage is not applied in a 
 larger proportion than about 200 persons for each acre. The sewage, too, 
 is freed from its coarser solid bodies by means of a Latham's extractor before 
 being used for irrigation, and this helps to prevent the deposit of foul sedi- 
 ment on the carriers and on the surface of the land. 
 
 One of the greatest difficulties connected with sewage farming is the 
 necessity of dealing with the enormous volumes of dilute sewage brought to 
 the farm by the drain-sewers of the combined system during and after periods 
 of heavy rainfall. At such times it is often inadvisable to apply the sewage 
 to land on which crops are being grown, which may already be sodden with 
 moisture, and the area of fallow land may be insufficient to deal with the 
 large quantities of dilute sewage that would have to be applied to it. An 
 obvious method of getting over the ditficulty is to relieve the sewers by means 
 of a storm overflow direct into the river. In doing this it may be contended 
 that the sewage is so excessively dilute that no harm is likely to arise from 
 its being allowed to enter the river ; yet, on the other hand, it must not be 
 forgotten that the same amount of sewage would still enter the river, although 
 with a larger body of water, that the manurial ingredients of the sewage so 
 discharged will be wasted, and that in towns where accumulation takes 
 place in the sewers on account of their faulty construction or of want of 
 regular flushing, the sewage so escaping is actually very much stronger than 
 it is in ordinary times ; and besides there is always the danger of the poisons 
 of enteric fever and other diseases being discharged into water which may be 
 used by towns lower down for domestic purposes. 
 
 Another and less objectionable method is that recommended by Mr. 
 Bailey Denton of connecting the storm overflow with osier beds laid out in 
 ridges and furrows, the osiers growing on the ridges. On reaching these 
 beds the flow ol sewage is checked, and this causes the deposit of the floating 
 
THE DISPOSAL OF BEFUSE %11 
 
 solid matters in the furrows, wliilst the flood water rises and overflows the 
 ridges and the osiers growing on them. These beds need not be under- 
 drained, as they are only required to clarify the sewage, which without tlie 
 check afforded by them would be impetuously discharged, together with all 
 its floating matters, into the river. Osier roots also tend to grow down in 
 long filaments, which on reaching the undcr-drains might find their way in- 
 side and block the pipes. Meadow land on the banks of a river has been 
 used for the same purpose, but it would seem that osier beds are preferable, 
 as they more perfectly clarify the sewage. 
 
 An even better plan is to set apart a portion of the farm where the land 
 is most porous as a filter bed, specially prepared and closely under-drained 
 six feet deep. The land may be left fallow, or laid out in ridges and furrows 
 and cropped with vegetables. The filter bed should be subdivided into plots 
 for the intermittent application of the sewage, and should be of extent suf- 
 ficient to purify the whole of the sewage by intermittent downward filtration, 
 when from any reason, such as excessive dilution, it is inadvisable to apply 
 the sewage to the general surface of the farm. Such a filter bed would, of 
 course, add somewhat to the expense incurred in the original construction of 
 the farm, but its great utility would far more than counterbalance its cost, 
 as on all farms, even where storm and subsoil waters are excluded from the 
 sewers, sewage irrigation of land where crops are growing is often attended 
 with considerable risk of injury to the plants. The result is that on sewage 
 farms, as usually conducted, the choice of crops is limited to such as are not 
 injured by the continual apphcation of sewage, and these being produced 
 in excessive quantity often exceed the demands of the local markets, and are 
 consequently almost worthless. If every farm had a filter bed of sufficient 
 area to cleanse all the sewage when not required for irrigation, a variety of 
 produce could be grown under the most favourable conditions, and the kind 
 and quantity of each crop could be regulated, as in ordinary farming, accord- 
 ing to the demand for it and the chance of reaping a fair profit by its 
 sale. 
 
 There can be no question that, as a general rule, the sewage would be 
 more valuable to the sewage farmer if rain and subsoil water were kept out 
 of it, as the farm would then not be liable to those sudden inundations vnth 
 enormous volumes of weak sewage which tax the resources of the management 
 to their utmost in their efforts to deal with it. But if this were done, there 
 is the danger of the sewage proving too strong for the crops and requiring 
 dilution, which is especially likely to be the case if the water supply of the 
 town is inadequate to the requirements of the population. In such cases it 
 would be advisable to have at hand some means of diluting the sewage before 
 its arrival at the farm, and this might possibly be effected by turning the 
 water of the subsoil drains into the sewers. At Breton's Farm at Eomford 
 during very dry seasons it has even been found necessary to return the pure 
 effluent water into the tanks and mix it with the sewage before applying the 
 latter to the ground in order to ensure the requisite dilution. 
 
 There is still another difficulty which remains to be discussed — namely, 
 that which is supposed to arise during severe frosts. But too much stress 
 has been laid upon this ; and as a matter of fact sewage irrigation continues 
 uninterruptedly during the coldest weather. It is true that a coating of ice is 
 formed over the surface of the farm, but the sewage, which never has a tem- 
 perature below 45° F., flows underneath this coating and sinks into the soil, 
 which remains quite unfrozen and open. As soon as the weather begins to 
 moderate, the sewage rapidly melts the ice above it. This is not only the case 
 in this country, but in Germany and America, where the winter cold is far more 
 
B78 HYGIENE 
 
 intense. Thus at Pullman, U.S.A., a visit paid to the sewage farm inFebruary, 
 1885, showed that, although for five days previously the temperature had not 
 risen to 0° F., and had been as low as —25°, the sewage was going on to the 
 land, but covered by a stratum of ice from 1 to 8 mches thick. On breaking 
 the ice and digging a hole in the groimd below with a spade, the soil was 
 seen to be unfrozen and perfectly open. As the weather moderated the 
 sewage rapidly melted the ice above it.' 
 
 Wecome now to the consideration of the crops that are best suited for sewage 
 irrigation, and from the growth of which it is most reasonable to expect to 
 derive a profit. A committee of the Local Government Board on Modes of 
 Treating To-ftTi Sewage reported as long ago as 1876 that Italian rye-grass is 
 probably in all respects the most advantageous crop to be grown under sewage. 
 Subsequent experience has, we think, fully confirmed the favourable opinion 
 of the committee, and Italian rye-grass is now, as then, the staple product of 
 most sewage farms. Its advantages were stated by the committee to be as 
 foUows : ' It is capable of absorbing a larger volume of sewage than any 
 other crop. It occupies the soil so as to choke down weeds, comes early 
 into the market in spring, continues through the summer and autumn, 
 bearing from five to as many as seven cuttings in the year, and producing 
 from thirty to fifty tons of wholesome grass upon each acre.' 
 
 It is certainly the fact that plots of rye-grass may be almost continuously 
 treated with enormous volumes of sewage, not only without injury, but even 
 with benefit to their growth. Dr. Alfred Carpenter has stated his belief that 
 this plant possesses the power of absorbing and assimilating the organic 
 matters of sewage directly, unlike plant life in general, for which complex 
 organic bodies must be reduced to such simple constituents as ammonia, 
 nitrates, and phosphates before they can be assimilated. However this may 
 be, there can be no doubt that Italian rye-grass flourishes under a treatment 
 with sewage which would kill most other plants, and that it at the same 
 time very materially aids in the cleansing of the sewage with which it is 
 irrigated. 
 
 Although this is the case, the area of land placed under this crop must 
 have some reference to local means of consumption, or the crop, or a part 
 of it, may be wasted. For the grass when cut will neither keep nor bear long 
 carriage, and although in a warm and dry summer good hay may be made 
 from it, or ensilage in a wet season, where silos are at hand, still it is diffi- 
 cult to dispose of such fodder at a profit, owing to cost of carriage. Practical 
 experience has shown that the rye-grass is turned to its most profitable use 
 when used for feeding milch cows or rearing stock. It therefore follows 
 that, should the acreage of the sewage farm justify the experiment, a stock 
 and dairy farm ought to be associated with it. This experiment has been 
 carried to a very successful result at Birmingham. At first there is gene- 
 rally a certain prejudice to be overcome on the part of the consumers in the 
 neighbourhood agamst sewage-grown produce and the milk and meat from 
 animals fed off it. But this sentiment quickly wears away for want of 
 any reasonable basis. For, as we shall presently have occasion to show, not 
 only is sewage-grown produce neither dropsical nor prone to decomposition, 
 but evidence is entirely wanting to prove that its consumption has at any 
 time caused disease. The meat and milk also of animals reared and kept 
 on sewage farms in no way differs from the milk and meat x^roduced on 
 ordinary farms. We see, then, that Italian rye-grass is likely to be a profit- 
 
 ' Beport of the Mystic, Blackstone, and Charles Rivers Draiymge Commission, Mass., 
 U.S.A., 188f5. 
 
THE DISPOSAL OF BEFUSE 879 
 
 able crop if it can be converted into milk, butter, and meat, and that, under 
 such circumstances, it can be cultivated in large quantities, but that on 
 farms where livestock is not kept it may on occasion prove a drug in the 
 market, and have to be given away. 
 
 After three years the plot of rye-grass should be ploughed up, and the 
 land sown with cabbages, swedes, or mangolds. For these, as for nearly all 
 other crops grown on sewaged land, yearly rotation is the best. Cabbage 
 and mangold wurzel were considered by the Local Government Board Com- 
 mittee to be the only farm crops, besides Italian rye-grass, that persistently 
 flourish upon any soils, heavy or light, under continual doses of town 
 sewage. And even these should only be sewaged when growing, and not when 
 they have arrived at maturity. They no doubt help to exhaust the soil of 
 the sewage matters retained in it, which have not been absorbed by the rye- 
 grass. The same committee also stated that no growing crop, save natural 
 grass, should be sewaged during the depth of winter ; and for potatoes, 
 turnips, most vegetables, and certainly for all pulse and cereals, the land 
 ought rather to be enriched by frequent irrigation in the preceding season 
 than treated with sewage when these crops are growing, except in times of 
 great drought, and even then care is requisite. There can be no question 
 that fallow land is enriched by irrigation with sewage from retention in the 
 soil of some of its manurial ingredients, just as when solid manures are 
 applied. 
 
 From what has gone before, it will be evident that unless a sewage farm 
 is provided with a special filtration area to dispose of the sewage when not 
 required for the fertilisation of the land, or unless the area of land is con- 
 siderably in excess of that necessary for cleansing the sewage, the crops are 
 practically limited to the three that are not injuriously affected by sewage 
 irrigation when in growth, viz. Italian rye-grass, cabbages, and mangolds, 
 in addition to natural meadow grass and osiers. On such farms, therefore, 
 it would be useless to look for a profit from the sale of produce. But on 
 the farms where a special filtration area is provided, or that have a large 
 acreage for the volume of sewage, not only can numerous other crops be 
 grown with little risk of their being spoilt by the enforced application of 
 sewage, but market gardening even may be undertaken and made very 
 profitable. Italian rye- grass, however, from the peculiar conditions under 
 which only can sewage farming be undertaken — viz. the necessity to purify 
 the sewage night and day, Sunday and week-day, wet weather or fine 
 — must always be the staple crop, and, as we before said, it can only 
 be profitably utilised by employing it as fodder for livestock on the farm 
 itself. . 
 
 The amount of capital required to stock and work a sewage farm is 
 very greatly in excess of that required for an ordinary farm on the same 
 kind of soil. The Local Government Board Committee stated that five 
 times the usual amount of money would be needed for a sewage farm upon 
 which most of the produce is consumed. There is a far larger amount of 
 labour required to keep the land clean and free from the weeds which the 
 sewage tends to foster, and to take off the land the enormous crops of 
 grass and roots that are grown. But against this must, of course, be set the 
 increased value of the crops over those of an ordinary farm. 
 
 We come now to the consideration of the manurial value of the sewage 
 and to the practical results that can be obtained by its use. We have 
 already stated briefly the conditions under which sewage farming may be 
 undertaken with some prospect of success, and we shall suppose that these 
 conditions have been either totally or in large part complied with. It ia 
 
880 HYGIENE 
 
 now pretty "well known that sewage farms are not always or necessarily a 
 success, either in purifying or utilising the sewage ; and to establish a farm 
 on heavy clay soil, without sufficient land or witliout the other essential 
 elements previously alluded to, is merely to court defeat in one or both par- 
 ticulars, and most probably in both. 
 
 The water of the sewage is a great difficulty, where no precautions have 
 been taken to deal with excessive quantities of it ; but where these have 
 been taken the water has its uses, which counterbalance its di-awbacks. It 
 enables the sewage farmer to be independent of drought in dry seasons 
 and to rear large crops of meadow and rye-grass, roots, and cabbages, for 
 the growth and maintenance of which moisture is so essential. In the 
 parched-up land around the sewage farm during a period of drought these 
 crops are failures, and consequently the sewage-grown crops are enormous 
 comparatively in volume, and command a correspondingly high price in the 
 market. Then, again, the water is the vehicle for ammonia and organic 
 matters in solution ; and such fertilising matters are more readily absorbed 
 by the roots of plants when in solution in water than in any form of solid 
 manure. The water of the sewage, then, is of use as a fertilising agent,, 
 as well as a. vehicle for the manurial matters which it carries with it. 
 
 As regards these manurial matters of the sewage, we have seen what 
 they are worth theoretically in a ton of sewage both in the form of matters 
 in suspension and matters in solution (see p. 850). What they are worth 
 practically is shown by the statistics of the crops raised on sewage farms, 
 and by a comparison of these statistics with those derived from farms on the 
 same kind of soil where sewage is not applied. It is not possible in thi& 
 article to examine these figures, but the general result may be stated to be 
 that such crops as thrive under sewage are produced in far larger quantities 
 on sewage farms than on the ordinary farms of the neighbourhood, and are 
 obtained very much earlier in the spring season, no doubt from the warmth 
 of the sewage keeping up the temperature of the soil throughout the cold of 
 winter. What the value of such crops may be has been already the subject 
 of consideration ; but it must also be remembered that fallow land is enriched 
 by the application of sewage, and that where this is done in the season pre- 
 ceding the raising of pulse, cereals, or vegetables, it is not necessary to apply 
 solid manures as well, so that a very considerable source of expense is saved 
 to the farmer. It may indeed be stated generally that sewage contains every 
 fertilising ingredient required by any soil, so that artificial or foreign 
 manures can be entirely dispensed with on a sewage farm. If this were not 
 the case it would have been impossible to obtain any produce from those 
 plots of barren sea sand irrigated with sewage, of which the Craigentinny 
 Meadows, near Edinburgh, and the Dantzig Sewage Farm are such striking 
 examples. At Craigentinny enormous crops of Italian rye-grass are produced,, 
 whilst at Dantzig the farm has been productive of excellent crops of grasses, 
 roots, and cereals. The latter, indeed, appear to thrive well on this very 
 porous soil when treated with large doses of sewage. It is said to be a truly 
 curious sight here to see, surrounded by irregular dunes of blowing sea-sand,, 
 vast spaces covered with a vigorous vegetation as a result of the application 
 of the sewage, which were formerly as barren as the surrounding sand-hills. 
 As another example, we may mention the Plain of Gennevilliers, near Paris, 
 where a barren and unfruitful waste has been turned by means of sewage 
 irrigation into a vast garden, 400 acres in extent, producing flowers, fruit, and 
 a large variety of crops for the Paris market. (' Les Travaux d'Assainisse- 
 ment de Dantzig, Berlin, Breslau,' par M. Durand-Claye.) 
 
 The value of sewage is indeed, after all, to a large extent a question of 
 
THE DISPOSAL OF BEFUSE 881 
 
 soil. On rich lands, which are often of a retentive nature, the advantage 
 of further enriching the soil with the manurial matters of the sewage is often 
 more than counterbalanced by oversaturation of the land with water. On 
 poor and barren soils, however, which are moreover usually highly permeable 
 to water, the sewage introduces the fertilisers which are naturally absent, and 
 without which no crops can grow ; whilst the excess of water rapidly perco- 
 lates down to the subsoil, leaving the top soil in the most favourable condi- 
 tion for the growth of plant life. The value of the land, as at Craigentinny 
 and Dantzig, is enormously increased, and what was before a barren waste 
 becomes land capable of cultivation and of producing crops of large value. 
 Here, then, we see sewage utilised to the best advantage, and a noxious waste 
 product converted into a valuable source of food supply. 
 
 Having endeavoured to make it apparent that sewage is under certain 
 conditions and circumstances a fertiliser of the soil of the greatest practical 
 value, we can now turn to certain experiments which have been made with 
 the view of estimating the amount of nitrogen recovered in the crops of a 
 sewage farm from the sewage applied to the soil. 
 
 These experiments were conducted by the Committee of the British 
 Association on the Treatment and Utilisation of Sewage, and were made upon 
 Breton's Sewage Farm, near Eomford, extending over a period of five years 
 (1871-6). The committee ascertained that the amount of nitrogen recovered 
 in the crops during the whole of this period was equal to 32-88 per cent, of 
 the amount applied in the sewage to the surface of the soil, and that the 
 amount recovered per acre of the farm under crop averaged 182 lbs. annually. 
 As was to be expected, the committee found considerable annual variations 
 in the percentage of nitrogen recovered, these variations being dependent 
 upon changes in local circumstances. About 11 per cent, of the total 
 nitrogen applied to the land escaped in the effluent water, but of that only a 
 fractional percentage was in an organic form, the largest proportion existing 
 in the oxidised form of nitrates. About 56 per cent, of the nitrogen applied 
 in the sewage is unaccounted for, but of this a portion must have been 
 retained in the soil of the farm, which it served to enrich. For it was found 
 on comparing the analysis of the average composition of the soil of the farm, 
 made previously to the application of sewage, with a similar analysis made 
 in 1878 that the phosphoric acid in the soil was increased nearly sixfold — viz. 
 from O'Ol to 0*058 per cent. ; the loss on ignition of the soil was much greater 
 (leaving water out of the question) ; the amount of ammonia had increased 
 from an inappreciable quantity to 0-016 per cent. ; and the amount of 
 nitrates had also increased. 
 
 These results the committee considered highly satisfactory (especially 
 when the extreme porosity of the soil and limited area of land available for 
 irrigation are taken into account), as in the experiments of Messrs. Lawes 
 and Gilbert only from 40 to 60 per cent, of the nitrogen applied in solid 
 manures was recovered in the crops within the season of application. The 
 committee also called attention to the very careful way in which the samples 
 were taken and submitted to analysis, the results obtained for the sewage 
 and effluent water being as absolute and exact as accurate gauging and 
 careful analysis could make them, and those for the crops calculated 
 by means of the most reliable published data. The observations also 
 cover a larger area of land and a greater variety of crops than have ever 
 hitherto been scientifically made. As regards the samples of sewaged soil, 
 they were very carefully taken at the same part of the farm as the samples 
 had been taken before the application of sewage, and were mixed to form an 
 average sample for submission to analysis. 
 
 VOL. I. 3 Ii 
 
€82 HYGIENE 
 
 It was at one time thought that sewage when exposed to the air in open 
 carriers on sewage farms would lose a large proportion of ammonia, its most 
 valuable fertilising ingredient. The researches of the Rivers Pollution Com- 
 missioners, however, have shown that this is not the case. On exposure of 
 a solution of carbonate of ammonium, 9"25 parts in 100,000, in a layer of only 
 2 inches deep, to a strong draught of air for three days, the solution at the 
 end of this time still contained the same proportionate amount of ammonia 
 — that is to say, it lost ammonia precisely in proportion to the evaporation 
 that took place ; or, in other words, the difference between the volatility of 
 the ammonia and that of the water in such solution and after such a time 
 is, under the most favourable conditions, inappreciable. Seeing that the 
 sewage in an open carrier would generally be deeper than 2 inches, there 
 is no reason to fear any appreciable loss of fertilising effect from the evapo- 
 ration of its contained ammonia during a flow through even a great length 
 of conduit. 
 
 It is true that the evaporation of water from the surface of a sewage farm 
 is enormous in amount. The British Association Sewage Committee found 
 that, on an average of over a year's (399 days) observation, only 47 "3 per cent, 
 of the sewage pumped on to Breton's Farm was discharged through the deep 
 drains as effluent water. The rainfall at the farm during the period of 
 observation, being 22-f)4 inches, introduced on to the land the equivalent in 
 water of 235 days' flow of sewage, so that the amount of evaporation from 
 the surface of the land is seen to be enormous. But at the same time it 
 must be remembered that some of this water is not evaporated at all, but is 
 absorbed by growing vegetation, whilst that which is evaporated must be to 
 a large extent given off by the leaves of plants, which give off' water but not 
 ammonia ; so that there is no reason to suppose that excessive evaporation 
 means a great loss of ammonia. 
 
 We may conclude, then, both from a consideration of the practical farming 
 results attained, and of the experimental investigations that have been made, 
 that sewage is in every sense a valuable manure, for it enriches the soil and 
 gives up some of its fertilising ingredients to the crops growing on sewaged 
 land, these ingredients being to a notable extent those which vegetation 
 exhausts from the soil, and which it is the rdle of manures to resupply in a 
 form capable of easy assimilation and absorption. 
 
 We come now to the consideration of the character of the effluent water 
 from sewage farms, and to inquire what degree of purity such waters exhibit 
 mider different local circumstances. From what has been previously stated, 
 it will be evident that the effluent water exhibits its highest degree of 
 purity when the sewage percolates through the soil, and is not applied too 
 continuously, nor in too large volumes to each plot of land. The following 
 analyses were made by the Sewage Committee of the British Association on 
 Breton's Sewage Farm, near Romford, where the soil is of a porous nature, 
 and the sewage is very efficiently filtered by percolation through the soil. 
 The analyses represent the average composition of the sewage pumped on to 
 the farm from March, 1872, to March, 1873, and of the effluent water escaping 
 from the deep drains. It is important to note that these analyses were made 
 of average samples — that is to say, of samples taken in proportion to the rate 
 of flow of the sewage at the time, as indicated by the gaugings. But in 
 comparing the analysis of the sewage with that of the effluent it must be 
 remembered that about two volumes of sewage are concentrated by evapo- 
 ration into one volume of effluent, in spite of the addition of the rain water 
 to the latter, for, as before stated, only 47*3 per cent, of the sewage applied to 
 the land escapes from the deep drains as effluent water. As regards the 
 
THE DISPOSAL OF BE FUSE 
 
 883 
 
 effluent water, then, a very considerable correction is necessary to rectify 
 the result, if the comparisons of sewage and effluent water are to be made 
 according to the respective volumes of each, by placing the evaporated water 
 to the account of the effluent. 
 
 Results cji/ven in ]}arts per 100,000. 
 
 Nilrogeji 
 
 In Solution 
 
 In Suspension 
 
 Total in Solution 
 and Susijension 
 
 - 
 
 As Ammonia 
 
 Organic 
 
 As Nitrates 
 and Nitrites 
 
 Total 
 
 Sewage . . . 
 Effluent , . . 
 
 2-6 
 0-072 
 
 1-05 
 0-147 
 
 
 
 0-947 
 
 3-65 
 1-166 
 
 1-75 
 
 
 5-4 
 1-166 
 
 From these analyses it will be seen that a large proportion of the nitrogen 
 in the effluent exists in the form of the innocuous residues, nitrates and 
 nitrites. 
 
 The Elvers Pollution Commissioners have also recorded analyses of sewage 
 and effluent from sewage farms, of which we may cite one example. At the 
 Lodge Farm, near Barking, where the soil is a pervious gravel, the organic 
 nitrogen was reduced from 3*664 parts in 100,000 of the sewage to 0'329 
 parts in 100,000 of the effluent water ; the ammonia was reduced from 4 to 
 0"8 part per 100,000, whilst nitrates and nitrites, which were absent from 
 the sewage, appeared in the effluent water to the extent of nearly 3 parts 
 per 100,000. 
 
 It would be possible to quote other analyses pointing in the direction of a 
 very highly purified effluent as the result of irrigation under favourable 
 circumstances. But it will be enough here to sum up the general results as 
 follows : — All the constituents of sewage are greatly reduced by irrigation, 
 with the exception of chlorine, which is very slightly reduced, or even some- 
 times apparently increased, owing to the concentration effected by evaporation ; 
 but the constituents which are most effectually removed from the sewage are 
 especially the putrescible organic matters — those, namely, which it is essential 
 to remove both from an agricultural and sanitary standpoint. Nitrates and 
 nitrites do not exist in the sewage, but are usually found in the effluent water 
 to some extent, and are evidence of the oxidation processes to which the 
 sewage has been exposed in the soil. 
 
 As a rule, then, it may be taken that nitrates and nitrites are found to a 
 considerable extent in all well-purified effluents, and that their absence indi- 
 cates deficiency of oxidation and inability on the part of the soil to properly 
 cleanse the sewage. 
 
 As regards farms on which surface-flow, and not filtration, chiefly takes 
 place, the effluent is not so well purified. Such farms are those in which, 
 there being a somewhat retentive soil, systematic under-drainage has not 
 been carried out. But even here, when the amount of land is sufficient, the 
 oxidation by surface flow, and the retention and absorption of putrescible 
 matters by growing plants, are usually capable of producing an effluent — not 
 indeed highly purified, but quite sufficiently pure to enter the watercourses 
 of the locality. If in such cases the land is totally insufficient in area, it 
 speedily becomes water-logged to such an extent that the sewage flows over 
 it and passes away almost unpurified into the streams. But such instances 
 cannot be taken as examples of properly conducted sewage farms, and are 
 condemned alike by advocates and opponents of sewage irrigation. 
 
 3l2 
 
P84 HYGIENE 
 
 "Where the soil of a farm is very clayey and retentive, filtration is an- 
 impossibility ; and in such cases surface flow must be entirely relied upon, 
 and under-drainage is liable to do more harm than good, for the reason that 
 in dry summers large cracks and fissures form in the soil, so that the sewage- 
 passes away directly from the surface of the ground to the under-drains without 
 having been purified at all, and is discharged in this condition into the 
 streams. Under certain conditions surface-flow may be relied upon to give 
 a fairly pure eftluent, and we cannot do better than quote the Wimbledon 
 Sewage Farm as an example. 
 
 Here the sewage of about 25,000 people is first precipitated with lime, 
 lime and herring-brine, or lime and sulphate of alumina. The clarified 
 eliluentfrom the tanks is applied to sixty-six acres of land, consisting very largely 
 of stiff clay soil. The sewage is thus seen to be applied in the proportion of 
 about 380 persons to each acre. The sewage flows from one carrier to 
 another over the land on the catchwater system, such purification as it 
 receives being entirely due to surface flow and not to filtration. There is no 
 under-drainage, such under-drains as formerly existed having been taken out 
 of the ground and removed. The land is extensively planted with Italian 
 rye-grass and osiers, but cabbages and mangolds are also grown on ridges, 
 and are well sewaged. The sewage first passes over successive plots of rye- 
 grass and finally over an extensive osier bed before reaching the river 
 "Wandle. On the occasion of our visit the effluent, as it passed into the river, 
 was clear, colourless, and inodorous, and apparently in a perfectly fit state 
 to be discharged into the stream. There is a storm overflow to the outfall 
 sewer, which discharges the storm waters and sewage after heavy rainfall 
 on to an osier bed, wiaere some of the suspended matters are kept back from 
 the sewage before it reaches the river. The satisfactory result attained at 
 Wimbledon is no doubt largely due, first, to the removal of the suspended 
 matters of the sewage by precipitation in tanks, and secondly, to the com- 
 paratively large area of land available for irrigation, and to the care with, 
 which the land is kept cropped ; but even here we should expect that in 
 winter the purification would be less efficiently performed than in the warmer 
 months, as during the cold season plant life and activity are in abeyance. 
 This was found by the British Association Committee to be the case on the 
 Beddington and Norwood Farms when visited in winter. The rye-grass 
 yields an average of five cuttings in a season, and is bought by farmers in the 
 neighbourhood, who cart it off the land. 
 
 It will be necessary at this point to allude to the so-called ' sewage fungus "■ 
 {Beggiatoa alba) which is so frequently found growing on the sides of the 
 carriers on sewage farms, in the effluent water channels, and on submerged 
 objects in the streams into which the effluent passes. This fungus was 
 formerly held to constitute, when found on the banks of rivers, evidence of 
 the pollution of the water with sewage or with an unpurified effluent. But, 
 inasmuch as this fungus feeds largely on sulphur, which it extracts from 
 mineral sulphates as well as from decomposing organic matters, it is found at 
 other places than in sewage-polluted waters, and is therefore in no way dia- 
 gnostic of sewage pollution. Even the most highly purified sewage effluent 
 ■v\dll contain abundance of mineral sulphates, so that Beggiatoa alba is likely 
 to be found in all waters into which such effluents are discharged. It cannot,, 
 then, he held to indicate the presence of putrefiable organic matters in the 
 water of streams in which it is found, but merely of an abnormal amount of 
 sulphates. There seems no reason either to believe that it has itself any 
 injurious effect on the water, except when found in large quantities, when 
 
THE DISPOSAL OF REFUSE 885 
 
 the fungus may cause nuisance by rotting in the water and giving off offen- 
 sive gases. 
 
 The influence of sewage farming upon the public health, either as being 
 productive of nuisance or actually causative of disease, must next arrest our 
 attention. It will be convenient to consider the question of nuisance in the 
 first place. 
 
 There cannot be the slightest doubt that badly managed sewage farms 
 may give rise to a very serious nuisance in their immediate neighbourhood. 
 The nuisance may be due to one of several causes : — (1) The sewage may arrive 
 at the farm in a putrid condition owing to the length of time it has been 
 retained in old and dilapidated or badly constructed sewers. The application 
 of such foul liquid to a large surface of land is pretty certain to give rise to 
 offensive effluvia, which will be the cause of complaint. (2) If ditches dug 
 in the soil are used as the permanent carriers, much of the solid matters in 
 the sewage will be deposited on their sides, and if this sediment is not re- 
 moved or dug into the ground, it will putrefy and give off" offensive gases. 
 -(3) Where too much sewage is applied to land consisting of clayey soil, the 
 sewage ponds on the surface and the stagnation lead to putridity with its 
 offensive accompaniments. 
 
 In all these cases it is obvious that proper dispositions have not been 
 made or that the management is at fault. The remedies indicated are (1) 
 the flushing or reconstruction of defective sewers, so that the sewage may 
 arrive at the farm in a fresh and undecomposed condition ; (2) the adoption 
 of permanent carriers of stoneware or concrete, which can be easily flushed 
 and cleansed ; (3) the acquisition of a larger area of land, and the breaking 
 up and close under-drainage of that which is too impervious to admit of a 
 proper amount of filtration of the sewage. 
 
 As regards carefully conducted sewage farms, there is very little evidence 
 that nuisance is caused to the neighbourhood. In dealing with so foul a 
 hquid as town sewage it is impossible to avoid all odour at aU times and at 
 all places ; but considering the number of sewage farms that now exist, dotted 
 all over the country, the fact that complaints from residents in their 
 neighbourhood are so infrequent as they are, is very valuable testimony 
 that sewage irrigation is productive of very little nuisance. To take only the 
 case of the Croydon Sewage Farm at Beddington, we learnt from the late Dr. 
 Alfred Carpenter that the locality around part of the farm has become a 
 residential neighbourhood, and that the value of land and the price of property 
 on the immediate borders of the farm have risen enormously in recent years. 
 There are no complaints of offensive smells at Norwood ; a public foot-path 
 through the irrigated fields is used as a pleasure walk by numbers of people, 
 many of whom are unaware of the character of the farm over which they are 
 passing. 
 
 There is, too, but very little evidence of disease being caused even by badly 
 conducted sewage irrigation. An outbreak of dysentery and diarrhoea in 1864-5 
 amongst the patients of the Cumberland and Westmoreland Asylum was 
 recorded by the medical officer (Dr. Clouston) as being due to the se"rt^age 
 farm which was in close proximity to the asylum. But here it seems that 
 strong and putrid sewage became ponded on the irrigation plot, forming a 
 filthy morass. Sewage is still applied on the grounds of this asylum, with 
 the difference that the irrigation is conducted on proper principles ; and from 
 1874 to 1887 Dr. Campbell, the present medical officer, has found no disease 
 or nuisance in any way arising from the distribution of the sewage. 
 
 There is, besides, evidence to show that the men who work on sewage 
 
886 HYGIENE 
 
 farms, and their families who reside there, exhibit a very low rate ofmortahty,. 
 and are quite as healthy as the labom-ers on ordinary farms. From the 
 returns of nine sewage farms which were in competition for the Eoyal 
 Agricultural Society's prizes it appears that the death-rate amongst the 
 residents on the farms, on an average of the number of years which they 
 have been in operation, does not exceed 3 per 1,000 per annum. This 
 rate is very likely not lower than that which would obtain amongst ordinary 
 agricultural labourers, but still it shows that sewage farming is not detri- 
 mental to health or life. 
 
 Epizootic and entozoic diseases amongst cattle have not been shown to 
 have been originated or favoured in their spread by sewage irrigation. The 
 late Dr. Cobbold, as long ago as 1865, published some considerations which 
 induced him to believe that sewage farming would tend to spread entozoic 
 disease both amongst men and cattle. With the view of testing the soundness 
 of the indictment thus preferred by Dr. Cobbold, the British Association 
 Sewage Committee subsequently made a very careful investigation of the 
 subject in conjunction with Dr. Cobbold himself, but they failed to trace 
 any such coimection. The committee found that on one farm there was 
 a remarkable absence of those molluscan and insect forms of life which 
 fi'equently play the part of intermediary bearers to entozoal larvae, and 
 without which the cycle of their existence cannot be continued ; and they 
 also pointed out that alkaline sewage probably destroys organisms whose 
 natural habitat is the acid secretion of the human intestines, and, if so, 
 they must be destroyed in the sewage before they arrive at the farm. It hag 
 also been recorded that wire-worms {Oscinis vastator), which do so much 
 injury to cereal crops, have been entirely destroyed by dressings of sewage 
 applied to the affected plants. 
 
 It may be stated, then, that the consumption of sewage-grown produce, 
 whether by men or beasts, has never been shown to be a cause of parasitic 
 disease in either, and that there is no probability of its being ever likely to 
 prove so. As regards the feeding of cattle on irrigated meadows, it certainly 
 seems more cleanly to allow the sewage to sink away into the soil before 
 admitting them on to the land, though there seems to be no appreciable risk 
 incurred by a contrary practice. 
 
 Subsoil Ieeigation 
 
 For the disposal of the sewage of towns surface is preferable to subsoil 
 irrigation. The utilisation is more complete, the purification is more certainly 
 ensured, and surface carriers are more easily cleansed than underground 
 drains. But for isolated houses and groups of houses in country districts, 
 where the purification of the sewage would have to be effected on land 
 adjoining inhabited premises, it is often advisable to have recourse to subsoil 
 irrigation in preference to the other method. Subsoil irrigation can also be 
 relied upon to purify the slop waters of houses in country districts where 
 some form of dry closet is in use for the disposal of the solid human 
 excreta. 
 
 The slop waters of villages are but little less impure than water-closet 
 sewage, and are usually got rid of in rural districts by being allowed to pass 
 into ditches or streams ; they are undoubtedly productive of considerable 
 nuisance. They contain, however, somewhat less of solid floating and 
 suspended matters than water-closet sewage, so that, whereas it is advisable 
 to strain the latter liquid to remove the larger sohd bodies before using it 
 for sub-irrigation, such a proceeding is not required for the cleaner slop waters. 
 
THE DISPOSAL OF REFUSE 
 
 887 
 
 A very small piece of ground only is required to purify the slop waters of 
 a single cottage or small house ; but in the case of a village, where the 
 houses are in fairly close proximity, it would probably be better to adopt a 
 combined system and to carry the slop waters of the whole village in a pipe 
 sewer to a piece of land outside. Larger houses standing in good-sized 
 grounds could purify their slop waters or sewage on their own premises, 
 and would probably find it advantageous to do so, as the liquid manure 
 when applied to the land would no doubt considerably increase the garden 
 produce. 
 
 The plot of land chosen for sub -irrigation should be of a light and porous 
 character, to ensure the efficient filtration of the sewage liquid, and should, 
 if possible, have a gentle steady slope. To avoid the necessity of pumping, 
 the plot of ground should be, if possible, at a lower level than the house or 
 houses from which the sewage flows. At a depth of from G to 12 inches 
 from the surface of the soil should be laid a systen of 2-inch porous earthen- 
 ware pipes, placed about 5 or 6 feet apart, with open joints between the 
 lengths of pipe (each pipe being about a foot in length). The ends of the 
 pipes should be supported upon cradles, made of half pipes, and protected 
 above by similar covers, to allow for the escape of the water and to pre- 
 vent earth getting into the pipes (figs. 
 183 and 184). The system should 
 be connected at its highest end with 
 the water-tight drain conveying the 
 sewage to the land, and from this 
 point the pipes should have a slight 
 fall away of 6 or 8 inches in 
 100 feet, and should ramify under 
 the soil over the entire area of the 
 plot. 
 
 Where the soil is very porous no 
 further drainage is required ; but with 
 the more retentive soils it is advisable 
 to lay a drain at a short distance from 
 the ends of the pipes lo collect the 
 effluent water and convey it into the 
 watercourse. 
 
 Fig. ISiJ. — Drains for sub-irrigation. 
 
 Fig. 184. — Sub-irrigation drains. 
 
 It is now usual in the case of single houses to collect the slop waters or 
 strained sewage in a siphon fl.Tish tank (fig. 185), which discharges its contents 
 automatically at regular intervals into the sub-irrigation drains. The reason 
 for doing so is that the waste waters passing away from a single house flow 
 in a mere dribble, so that the liquid penetrates but a very short way along 
 the sub -irrigation drains, and the pipes become in time choked with de- 
 posited sediment. That portion of the sub -irrigation plot, also, which is 
 nearest the house-drain receives very much more than its proper share 
 of the irrigating liquid, so that its cleansing properties become speedily 
 overtaxed. 
 
 The flush tank (fig. 185), on the other hand, stores the dirty water 
 until a considerable volume is collected and the tank is full, when it suddenly 
 
888 
 
 HYGIENE 
 
 discharges its contents, which escaping in large vohime with a high velocity 
 reach every part of the sub -irrigation plot. By this means, then, each 
 portion of the land receives its due share of the irrigating liquid, and 
 receives it intermittently — viz. at such periods only as the tank discharges, 
 which, of course, depend on the capacity of the tank in relation to the volume 
 of water it receives in the twenty-four hours— and purification and utilisation 
 are thereby greatly facilitated. The tank now in most general use is that 
 fitted with Rogers Field's annular siphon arrangement. This tank in 
 practice is found to work very well : a very small dribble of water only is 
 required to start siphonage when the tank is full ; and ' dribbling ' and ' con- 
 tinuous action ' — by which is meant that when the tank is full, water dribbles 
 continuously down the discharge pipe as fresh water enters the tank, but 
 the tank does not properly siphon itself— are not found to occur if the tank 
 is placed on a perfectly level surface with the discharge pipe quite plumb. 
 
 The sewage or slop waters should be conveyed to the sub-irrigation plot 
 by a greater or less length of water-tight drain, according to circumstances. 
 
 Fig. 185. — Field's automatic siphon flush tank. 
 
 When the liquid reaches the porous drains it very rapidly escapes through the 
 open joints between the lengths of pipe into the soil, where some of its pol- 
 luting ingredients are absorbed or assimilated by the roots of the grasses 
 and other vegetables grown on the plot, and the remainder are purified by 
 oxidation and nitrification as the water percolates more deeply into the soil. 
 The purifying agencies are the same as in intermittent downward filtration, 
 of which, indeed, subsoil irrigation is merely a variety, the irrigating liquid 
 being applied a few inches beneath the soil instead of from the surface. 
 In like manner, also, the effluent water escapes from the drains, free from 
 all polluting organic constituents (provided the area of the sub-irrigation plot 
 is sufficiently large to absorb and cleanse the sewage applied to it), and may 
 at once be allowed to pass into the nearest watercourse. If the soil is very 
 porous, the efiluent water may be entirely lost in it by percolating deeply 
 until it reaches the subsoil water. 
 
 The sub-irrigation drains may require to be taken out of the soil, and any 
 deposit that has collected m them removed before they are relaid, about once 
 in five years or more, according to circumstances. 
 
THE DISPOSAL OF REFUSE 889 
 
 THE DISPOSAL OP MANUFACTUBING REFUSE 
 
 In manufacturing districts the pollution of streams is probably quite as 
 largely due to the discharge of waste waters from factories as to the entrance 
 of house sewage into the river waters. These waste liquors are in many 
 cases of a highly polluting character, containing organic refuse of various 
 descriptions, or poisonous metallic compounds, which kill the fish in the 
 river and effectually put a stop to the natural processes of oxidation which 
 are capable of repurifying polluted waters under certain conditions (see p. 851). 
 The spent liquors from dyeing works may give the water a black or dark- 
 coloured appearance, so that rivers polluted with manufacturing refuse are 
 often as objectionable to sight as they are to smell and taste. Of the offensive 
 condition of many streams in the North of England much evidence will be 
 found in the reports of the Rivers Pollution Commission. 
 
 There can be no doubt that town sewage is far easier to deal with, having 
 regard to its purification and utilisation, when unmixed with manufacturing 
 refuse, which often contains strong acids or alkalies or other poisonous resi- 
 dues, and are exceedingly injurious to vegetation when the sewage is ap- 
 plied to land. On the other hand, it is impossible for municipal authorities 
 to exclude such waste matters from the sewers, and it is difficult to see how 
 the manufacturers themselves could efficiently purify their waste liquids on 
 their own premises, which are often of very limited extent, when situated 
 within the town boundaries. 
 
 The Elvers Pollution Commissioners expressed the opinion that ' for 
 populous places which are also seats of manufacture it would generally be 
 possible, without materially complicating the sewage problem, to allow the 
 fluid refuse of industrial processes with few exceptions to pass into the 
 sewers to be disposed of as common sewage, the special exceptions being 
 the refuse of workers in metals and of manufacturers of gas, paraffin oil, 
 pyroligneous acid, and animal charcoal ; that, subject to some such exceptions 
 as these and to proper regulations, the discharge of fluid industrial refuse 
 into sewers would generally not render the sewage more difficult of use, 
 and would in some cases, in respect of certain contained refuse matters, 
 greatly increase the agricultural value of the sewage.' For instance, the 
 waste liquor from flannel works is exceedingly rich in ammonia and organic 
 matters, that from works at Newtown being found to contain in 100,000 
 parts no less than 1733'4 of suspended organic matters, 446-353 of dissolved 
 organic carbon, 91 'IBS of dissolved organic nitrogen, and 80*012 of ammonia. 
 But such cases of enrichment of sewage are probably exceptional, and can- 
 not be held to contradict the truth of the statement that sewage is easier to 
 treat when unmixed with industrial refuse. 
 
 Probably the best means of dealing with the sewage of manufacturing 
 towns is that pursued at Birmingham, of which mention is made at page 864, 
 The preliminary precipitation with lime carries down many of the compounds 
 which would prove deleterious to vegetation, and neutralises the acidity 
 arising from the presence of free acids or acid salts in the sewage. The 
 clarified and alkalinised effluent from the tanks can then be applied to land 
 with every prospect of attaining a successful result, both as regards its puri- 
 fication and its utilisation in the production of crops. 
 
 For factories situated away from towns, where no outlet for waste waters 
 into town sewers is possible, it would, as a rule, be desirable to resort to 
 intermittent downward filtration upon a specially prepared and under-drained 
 plot of land in the vicinity of the works. In most cases it would probably 
 
890 HYGIENE 
 
 be useless to attempt to raise crops on the filtration area, as the waste 
 liquors, even if they contain valuable manurial ingredients and are free from 
 poisonous salts or residues, usually contain these matters in too high a pro- 
 portion, \\'ith the result that only weeds and coarse grasses flourish on the 
 irrigated land, the finer produce being injured or killed. A preliminary pre- 
 cipitation of the waste waters with lime would no doubt tend to a more 
 successful result in the way of rearing produce, but the cost would pro- 
 bably be prohibitive, and the ultimate cleansing of the dirty water would 
 be but httle enhanced. It would, however, appear to be desirable in the 
 case of acid wastes to neutralise the liquid with hme Tsathout attempting to 
 precipitate it, otherwise nitrification of ammonia and organic matters in the 
 surface layers of the soil may be very greatly diminished, owing either to the 
 destruction of the nitrifying organisms themselves, or to the absence of the 
 salifiable base which should be present in the soil for the nitrous and nitric 
 acids, when formed, to combine with. 
 
 It has been amply demonstrated that intermittent downward filtration 
 carefully carried out on a suitable soil is capable of purifying the very foulest 
 specimens of industrial waste waters, and this is then the method which 
 should be everywhere employed where land of suitable quality and extent 
 can be obtained. If it is found impossible to acquire the necessary land, 
 then an attempt should be made to precipitate the suspended matters in 
 tanks by means of lime or other chemical substance, and to further purify 
 the efiluent by intermittent filtration through banks of coke, cinders, or ashes. 
 In this way it will be possible to procure a colourless and clear effluent, 
 which, if not entirely free from soluble polluting ingredients, is at least in- 
 capable of doing much injury to the water of the stream into which it is 
 discharged. 
 
 THE INFLUENCE OF SANITAEY WOEKS UPON PUBLIC HEALTH 
 
 It is perhaps hardly necessary at the present time to recapitulate the 
 evidence as to the beneficial effect upon the pubhc health of the works of 
 sewerage, drainage, and water supply, which have been so marked a charac- 
 teristic of the social progress of the latter half of the present century. It is 
 pretty generally recognised now that filth and disease stand to each other as 
 cause and effect ; but inasmuch as there is a tendency to forget facts which 
 are not presented to us constantly in every-day life, a brief resume of the 
 subject may not here be out of place. 
 
 Although accurate statistics are not available until civil registration began 
 at the commencement of the present reign, we can picture to ourselves fairly 
 correctly the condition of the public health in the seventeenth and eighteenth 
 centuries. In 1593 was commenced the system of registration of births and 
 deaths by the parish clerks of London from which we get a knowledge of 
 the causes of death, although it is impossible to construct death-rates, there 
 being no enumeration of population. That the death-rate during two 
 centuries — 1600 to 1800— must have been excessive, we know from the large 
 proportion to the total mortality of deaths from zymotic diseases, ague, and 
 consumption, which invariably indicate a high general death-rate. So high, 
 indeed, was the death-rate that the annual deaths invariably exceeded the 
 births in London, and the population was only prevented from diminishing 
 by immigration from the rural districts. Ague, dysentery, and consumption 
 figured largely in the mortality bills, and the mortality amongst infants and 
 young children was enormous. Typhus, small-pox, and measles caused a 
 
THE DISPOSAL OF REFUSE 891 
 
 large number of deaths, and in the sixteenth century plague and sweating 
 sickness were epidemics causing an enormous mortality, and even decimating 
 the population in certain years. Even in years when plague was absent, 
 preventable fevers alone probably accounted for at least one- quarter of the 
 deaths. 
 
 The causes of the excessive mortality must be sought in the filthy con- 
 dition of the city itself. The streets were unpaved, or paved only with rough 
 cobble stones. There were no sidewalks. The houses projected over the 
 roadway, and were unprovided with rain-water gutters, so that during a 
 shower the rain fell from the roofs into the middle of the street. The streets 
 were filthy from constant contributions of slops and ordure from animals and 
 human beings, any system of scavenging being unknown. There were no 
 underground drains, and the soil of the town was soaked with the filth of 
 centuries. This sodden condition of the soil must have affected the wells to 
 a considerable extent. The streets were filthy without, the houses were 
 filthy within. The rooms of the poor were more like pigstyes than human 
 habitations, unventilated and strewn with rushes, which were seldom changed,. 
 and the wretched inhabitants closely packed in these miserable hovels must 
 have been very prone to sufi'er from infection of all kinds. The city, too, was 
 surrounded with marshes, and this fact accounts for the exceeding prevalence 
 of ague and dysentery. ^ 
 
 Coming now to the present century, the sanitary condition of houses 
 and towns forty or fifty years ago all over the country was far superior to 
 that described as being characteristic of ancient London. But the system 
 which was then almost everywhere prevalent of collecting large accumula- 
 tions of human refuse in cesspools and midden pits, the consequent pollution 
 of well waters, and the absence of any proper scavenging arrangements, 
 caused still a high mortality amongst the population generally, and a very 
 considerable endemic prevalence of enteric fever, not to mention occasional 
 outbreaks of cholera and other diseases, invariably dependent upon faulty 
 methods of refuse disposal. The reports of the Health of Towns Commission, 
 1844-5, and of the Sewage of Towns Commission, 1861, drew forcible attention 
 to these faulty conditions as being the causes of much preventable sickness and 
 mortality, and their publication stimulated local sanitary authorities to under- 
 take those works of sewerage, drainage, and water supply which were so 
 urgently needed in the interests of improved pubhc health. 
 
 The great improvement in health, as evidenced by lowered death-rates, 
 which followed the execution of these sanitary works, is very fully brought to 
 hght in a report by Dr. Buchanan ' on the results which have hitherto been 
 gained in various parts of England by works and regulations designed to 
 promote the Public Health' (Ninth Eeport of the Medical Officer of the 
 Privy Council, 1866). Twenty-five towns, of very different populations, were 
 chosen to illustrate the effects of improved sanitation, these being the towns 
 where at that time structural sanitary works had been most thoroughly done, 
 and had been longest in operation. The nature of the sanitary operations 
 carried out in these towns was as follows : — A. Drainage works affecting 
 surface, subsoil, or houses. B. Improvements in water supply — amending 
 previous sources or substituting or adding new ones. C. Measures designed 
 for the removal of decomposing organic matters or for preventing contami- 
 nation of air or water thereby, viz. 1. The substitution of water-closets for 
 cesspools and middens. 2. The improvement of middens. D. Improved 
 paving, scavenging, and public cleanliness. E. Amendments of the lodg- 
 
 ^ London, Ancient and Modern, from a Sanitary Point of View. By Dr. G. V. Poore. 
 
892 
 
 HYGIENE 
 
 ment of the inhabitants, the regulation of common lodging-houses, and the 
 repression of overcrowding. 
 
 Of these towns, twenty exhibited a reduction in the death-rate for the 
 period after the completion of the sanitary works as compared with a certain 
 period before the works were commenced. The reduction was greatest in the 
 cases of towns like Cardifl" and Newport (32 per cent, reduction, or omitting 
 cholera 23 per cent.), where the previous death-rate was very high from the 
 existence of notable sanitary defects ; and was least in towns like Bristol, 
 where the pre^dous death-rate was not excessive. 
 
 The reduction of the death-rate from enteric (typhoid) fever is especially 
 noteworthy. In nine towns the reduction exceeded 50 per cent., being 
 highest in Salisbury, where the former rate of 0*75 per 1,000 was reduced to 
 0'175 per 1,000 — a reduction of over 75 per cent. In ten towns the reduc- 
 tion varied between 33 and 50 per cent. ; in two there was a trivial reduction, 
 and in three (Chelmsford, Penzance, and Worthing) more or less increase. 
 The reason of the increase in these three towns is explained by the fact of 
 insufficient ventilation of the sewers, combined with backing up of sewage in 
 them, so that sewer gases found their way into the houses. 
 
 It is instructive to follow up the decreased rates in these towns by a refer- 
 ence to the rates exhibited in modern years, the interval between 186G and the 
 present time being no doubt occupied in perfecting the sanitary works which 
 had at the former period only recently been completed. We can take the 
 cases of Cardiff, Leicester, and Bristol, which are three of the large towns the 
 statistics of which are published in the reports of the Registrar-General. 
 
 - 
 
 General Death-rate per 1,000 
 
 1 
 Enteric Fever Death-rate per 1,000 
 
 
 1847-54 
 
 1859-C6 
 
 188-1-8 
 
 1847-54 
 
 1859-66 
 
 188-1-8 
 
 Cardiff . . , 
 
 33-2 
 
 22-6 
 
 23 
 
 1-75 
 
 1-05 
 
 0-40 
 
 
 1845-51 
 
 1862-4 
 
 1884-8 
 
 1845-51 
 
 1862-4 
 
 1S84-8 
 
 Leicester . 
 
 26-4 
 
 25-2 
 
 20 
 
 1-45 
 
 0-77 
 
 0-22 
 
 
 1845-7 
 
 1861-2 
 
 1884-8 
 
 1845-7 
 
 1861-2 
 
 1884-8 
 
 Bristol . . - 
 
 24-5 
 
 24-2 
 
 18-9 
 
 1-0 
 
 0-65 
 
 0-14 
 
 It wiU be seen that, except in the case of Cardiff, where an altered social 
 condition of the population may account for the discrepancy, the general 
 death-rates of the towns have been much lowered in recent years. The 
 lowering of the enteric fever death-rate is even more remarkable, and should 
 be still more apparent than is shown by the tables ; for the rates for the 
 period 1884-8 are for ' fever,' which includes typhus and simple continued 
 fever as well as enteric. Typhus and simple continued fever formed 17 
 per cent, of the mortality from ' fever ' in England and Wales during the 
 period in question (1884-8), so that 17 percent, of the rates given under this 
 head for the three towns in the table should be deducted to render the com- 
 parison complete. 
 
 That these three towns are not exceptional instances is shown by the fact 
 that the whole country exhibits a similar decrease in enteric fever mortality 
 during the corresponding period (see diagram, p. 893). In 1869 (the first year 
 in which enteric fever returns, as separate from ' fever,' are obtainable) the 
 death-rate from enteric fever in England and Wales was 0*39 per 1,000 of 
 the population, and has steadily declined to the present time, the death-rate 
 in 1887 and 1888 being only 0-182 per 1,000 and 0-169 per 1,000,^ a reduc- 
 ' In 1889 the enteric fever death-rate was 0-173 per 1,000 ; in 1890 it was 0-179 per 1,000. 
 
THE DISPOSAL OF BEFTJSE 
 
 893 
 
 tion of over 50 per cent, in less than twenty years. The curve in the diagram 
 is interesting as showing the rapid decrease in 1876 and 1877, which follow- 
 ing as it did upon the passing of the Public Health Act of 1875, and the 
 appointment of medical officers of health throughout the country, is ifficient 
 evidence of the beneficial results that can be obtained by sanitary xmprove- 
 ments — more especially of those which have for their object the removal 
 of excreta by water carriage and the introduction of a pure water supply. 
 
 The same fact is brought to light in a rather different way by the accom- 
 panying table, page 894, which is taken from the Fifty-third Annual Keport 
 of the Registrar-General, 1890. From this table it will be seen that forty years 
 
 DeathTXZte I869 I870 I87l 1872 1873 IS7* 1875 1376 1877 1878 1679 1880 1^31 1862 1883 1884 1885 1888 1887 1888 
 
 fer 1.000. 
 
 •39 
 
 •38 
 
 •57 
 
 •36 
 
 •35 
 
 •34 
 
 •33 
 
 •32 
 
 •31 
 
 •30 
 
 •29 
 
 •28 
 
 •27 
 
 -26 
 
 •25 
 
 •24 
 
 •23 
 
 •22 
 
 •21 
 
 ■20 
 
 •19 
 
 •18 
 
 •17 
 
 •16 
 Fig. 186, 
 
 ~\ 
 
 
 
 
 
 
 V' — =v 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 ^ \ 
 
 
 
 
 
 
 ' '\ 
 
 
 
 
 
 
 V-A 
 
 i 
 
 
 
 
 
 \ 
 
 .-A... 1 
 
 
 
 
 
 
 
 
 
 
 1 
 
 ut 
 
 \ 
 
 
 
 \ 
 
 ' 
 
 / 
 
 \ 
 
 
 
 
 1 
 
 T 
 
 \ 
 
 
 
 r 
 
 ! 
 
 \ — 1 
 
 
 \ A 
 
 ~^ 
 
 
 
 u 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 \ . 
 
 "~— \ 
 
 
 
 
 
 V 
 
 N 
 
 
 
 
 
 
 
 -Curve showing death-rate from enteric (typhoid) fever in England and Wales 
 from the year 1869. 
 
 ago the general death-rate in urban districts was considerably in excess of the 
 rate current in rural districts. Both rates have declined, but the urban death- 
 rate to a considerably greater extent than the rural death-rate, for the reason 
 that sanitary works and measures have been prosecuted to a far greater 
 extent in towns than in the country, and the town populations have conse- 
 quently derived a greater advantage from sanitary improvements than the 
 rural communities. The difference in death-rate between town and country, 
 although really greater than here shown, owing to absence of correction of 
 the rates for the differing age and sex distribution in the respective populations, 
 is seen to be but slight at the present time as compared with the differences 
 in earlier years, when the sanitary conditions mider which rural populations 
 existed were immeasurably superior to those of the town populations. 
 
 Illustrations of the effect of sewerage on the diminution of enteric fever 
 
694 
 
 HYGIENE 
 
 - 
 
 Death-rate per 1,000 living in 
 
 Death in Town Districts 
 
 to 100 Deaths iu Country 
 
 Distviots iu equal 
 
 numbers liviug 
 
 England and 
 
 Town Districts 
 
 Country Districts 
 
 1851-60 
 
 1861-70 
 
 1871-80 
 
 1881-90 
 
 1881 
 
 1882 
 
 1883 
 
 1884 
 
 1885 
 
 1886 
 
 1887 
 
 1888 
 
 1889 
 
 1890 
 
 22-2 
 22-5 
 21-4 
 19-1 
 18-9 
 19-6 
 l9-(; 
 19-7 
 19-2 
 19-5 
 19.1 
 18-1 
 18-2 
 19-5 
 
 24-7 
 24-8 
 231 
 20-3 
 20-1 
 210 
 20-7 
 20-9 
 20-1 
 20-4 
 20-2 
 19-0 
 19-3 
 20-9 
 
 19-9 
 19-7 
 19-0 
 17-3 
 lC-9 
 17-3 
 17-9 
 17-6 
 17-8 
 18-0 
 17-2 
 16-6 
 16-4 
 17-4 
 
 124 
 126 
 122 
 117 
 119 
 121 
 116 
 119 
 113 
 113 
 117 
 114 
 118 
 120 
 
 prevalence and mortality may be taken from abroad as well as from English 
 cities. A very striking example is furnished by Mmiich,' which, prior to the 
 year 1880, when the city drainage was completed, was a city standing on 
 ground riddled with porous cesspools. From 18G6 to 1881 the average yearly 
 admissions of enteric fever to hospital were 591. In 1880 the admissions 
 were 492, but fell in 1881 — the sewerage works being then completed — to 
 99 ; and from 1881 to 1888 the yearly admissions average only 104, or little 
 more than one-sixth of the number admitted annually prior to the drainage 
 works. From 18G6 to 1880 the average number of deaths from enteric fever 
 in a year was 208 ; from 1881 to 1888 the average yearly number was only 
 40. From 1866 to 1888 the population of Munich has nearly doubled, 
 showing a rise from 152,000 in 1866 to 278,000 in 1888, so that the enteric 
 fever rates per 1,000 of the population in the pre-di'ainage period were 3'82 
 (hospital admissions) and 1*15 (deaths) and in the period subsequent to 
 drainage 0'42 and 0-16 respectively. This great result is to be ascribed 
 almost exclusively to the sewerage of the city and not to the introduction of 
 a new supply of water from a distance, for the sudden lowering of the enteric 
 fever mortality took place in 1881, soon after the completion of the sewerage 
 system, whereas the improved water supply was not carried out until some 
 years later. 
 
 A not less important result than the diminishing prevalence and fatality 
 of enteric fever is the practical extinction of cholera in this country. There 
 has been no cholera epidemic in this country since 1866. The absence of 
 this terrible scourge can hardly be attributed to want of opportunity, for on 
 several occasions cholera infection has reached our ports, but must rather 
 be looked for in the improved sanitary conditions under which the town 
 populations now exist, so that the contagion even if introduced fails to 
 establish a footing, and disappears for lack of those filth-engendered con- 
 ditions under which alone can it exert its powers of propagation. The 
 epidemic of 1866 was mild in comparison with that of 1854, and this in its 
 turn caused a far less mortality than its forerunner of 1848-9. All the 
 twenty-five towns examined by Dr. Buchanan showed this reduction, and in 
 many cases the epidemic of 1866 passed them by altogether, although the 
 previous outbreaks had been productive of a high mortality. 
 
 The mortality from diarrhoea was found to be greatly reduced in many 
 towns where sanitary improvements had been effected, but the reduction 
 
 ' Milnchener neueste Nachrichten. By Professor von Ziemssen, 1889. 
 
THE DISPOSAL OF BEFUSE 895 
 
 was bj no means so universal as in the case of enteric fever, and in some 
 cases the mortahty had increased no doubt as the result of an altered age 
 distribution of the population, a high birth-rate causing an increased pro- 
 portion of infants and young children in the population, on whom principally 
 diarrhoea exerts its effects. 
 
 Scarlet fever, measles, and whooping cough appear to have been but little 
 influenced as causes of death by the improvements in sanitary condition 
 consequent upon the execution of works of sewerage ; whilst of croup and 
 diphtheria Dr. Buchanan reported that they had increased in almost all the 
 twenty-five towns during or after the completion of their sanitary works, 
 and in many cases diphtheria seemed to have appeared during these altera- 
 tions and to have increased after them. Since the date of Dr. Buchanan's 
 report (1866) diphtheria has been steadily increasing as a cause of death in 
 most of our large towns. It was formerly regarded as being to a far greater 
 extent a rural than an urban disease ; but this view can no longer be enter- 
 tained when it is stated that the death-rate in London from this disease alone 
 was 0-37 per 1,000 in 1889, and 0-33 per 1,000 in 1890, and that it figures 
 almost if not quite so largely now as a cause of death in the weekly records 
 as measles and whooping cough, and far exceeds scarlet fever. A satisfactory 
 explanation is still wanting of this increasing mortality, but it is certain that 
 diphtheria is little influenced by the sanitary improvements which have so 
 marked an effect upon enteric fever. 
 
 One other disease remains to be mentioned as having been very greatly 
 influenced in fatality by the sanitary improvements enumerated in Dr. 
 Buchanan's report. In fifteen towns out of the twenty-five examined the 
 phthisis death-rate exhibited a reduction varying from 49 to 11 per cent. 
 This reduction can only be attributed to the drying of the subsoil which 
 accompanied the laying of the main sewers in the improved towns. Where 
 the drying of the subsoil was greatest, and where it was most needed, as in 
 Salisbury, Ely, Eugby, and Banbury, there the deaths from consumption 
 showed the greatest reduction. In the towns, on the other hand, where the 
 drying of the subsoil was inconsiderable, or had not taken place at all, 
 phthisis was found to be stationary or had even increased. In some cases 
 this was due to the fact that the soil already contained little water, and so 
 did not require draining, whilst in others the soil required draining, but no 
 subsoil drainage had accompanied the laying of impervious pipe sewers, 
 superficial culverts for storm waters only being thought necessary. 
 
OFFENSIVE AND NOXIOUS BUSINESSES 
 
 BY 
 
 THOS. WHITESIDE HIME, B.A., M.D. 
 
 VOL. I. 3 n 
 
OFFENSIVE BUSINESSES 
 
 The businesses which may come under the notice of the Health Officer as 
 giving rise to nuisance, or proving injurious to the health of the community, 
 are innumerable ; and they can only be classified with difficulty. They may, 
 perhaps, be best dealt with under the heads of (A) businesses dealing with 
 animal and vegetable matters ; and (B) those in which kno.vn gases or 
 vapours of mineral substances are evolved. 
 
 A. BUSINESSES DEALING WITH ANIMAL AND VEGETABLE 
 
 MAT TEES 
 
 These can scarcely be further classified, and will be described seriatim. 
 The slaughtering of animals for food is a business to which a separate 
 article is devoted (<i.v.) 
 
 SLAUGHTERING OF ANIMALS 
 
 The following is the mode of disposal of the most important parts, com- 
 monly regarded as ' offal : ' — 
 
 1. The blood of pigs and sheep is either used for making ' black puddings,' 
 mixed with fat and condiments ; or it is used for pig's-food ; or it is used for 
 making albumen (for which purpose the blood is received in shallow pans, 
 allowed to coagulate, and the clot being removed for manure the serum is 
 condensed and coagulated for albumen); or the fibrin having been removed 
 the remainder is sent to the turkey red dyer {vide Turkey Eed). 
 
 2. The Viscera. — The first stomach (paunch, tripes) of cattle and sheep 
 is cut open, emptied and cleaned for human food. The second stomach is 
 usually used as food for dogs or pigs. The heart is used as food for man ; 
 the lungs and liver are used so occasionally, but are more commonly given 
 to animals. The small intestines (running gut) are either sent to the gut- 
 scraper, after all the fat has been cut off them, or they are used for food for 
 animals, or thrown on the dung-heap. The small intestines of pigs are used 
 as sausage-skins, or go to the gut-scraper ; the large intestines are used asf 
 human food. 
 
 The fat of pigs is usually rendered into lard by the pig-killer himself. 
 The fat of cattle and sheep is commonly removed soon to the fat-melter. 
 The hides of cattle go to the tanner ; their feet to the tripe-boiler, and 
 sheep-skins to the fellmonger. 
 
 POULTEY 
 
 The keeping of poultry in large towns is often a great nuisance, especially 
 as it is generally in the very poorest localities, where air and space are so 
 scarce, that people will insist on keeping them. Poor people will keep fowls 
 in the cellars of their houses, or in the very small yards attached to them, 
 
 3m 2 
 
900 HYGIENE 
 
 and endure continuous hostility from their neighbours, rather than give- 
 them up. There is no way of abating tliis nuisance, as a rule, except by 
 abolishing it. Poultry are almost invariably brought dead to the food market 
 or poultry dealer's ; and it would be a great advantage if it were customary 
 to have them plucked also before they are brought from the country. 
 
 Knackekies ; Hobse-slaughtering 
 
 The knacker (originally knacker = saddler, who killed the animal and 
 utilised the skin) is a most useful public servant, not always held in such 
 estimation as he deserves. He properly is a horse-slaughterer, but he also 
 slaughters old and diseased animals other than horses, and commonly receives- 
 carcases of animals which have died of disease or violence as well. The 
 slaughtering of horses for food for man in such places should not be tolerated. 
 There is no reason why such animals should not very commonly be killed 
 where they are kept, instead of being conveyed alive, and at much greater 
 trouble, to the place of slaughter. 
 
 These places can be and should be conducted so as to be no more nuisance 
 than is a slaughter-house for cattle. Frequently they are managed in a very 
 offensive manner. In large towns they are often situated in poor, populous 
 districts, sometimes in the suburbs. 
 
 The principal sources of nuisance arise, not from the slaughtering, but 
 from subsidiary trades — bone-boihng, flesh-boiling (for cat's-meat or fat- 
 extraction), manure-makmg, &c. — which are commonly carried on at 
 knackeries to utilise the materials. 
 
 Where there is a large business many Uve animals may be received daily, 
 and may have to be kept for some days, necessitating the provision of food 
 and shelter for them. 
 
 The horse is slaughtered in the same manner as an ox (by the poleaxe or 
 the head-strap and spike), and afterwards all the soft parts are stripped fi-om 
 the skeleton, which, in turn, is broken up and utilised for boiling (fat, size, 
 &c.), like all the rest of the carcase, except the feet and the long hair of the 
 tail. 
 
 Knackeries may become offensive owing to the filthy way in which the 
 live animals are kept before slaughter, or owing to putrid carcases or other 
 material being allowed to remam on the premises ; or owing to the steam from 
 the boiling of bones and meat, or in consequence of the hot boiled material 
 being left lying about to cool, and giving off offensive vapour ; when putiid 
 stuff' has been boiled this nuisance is greatly increased. Complaints are also 
 sometimes made of very offensive smells from the public drains, owing to 
 the liquor, especially if it is hot, being discharged into them. But the dis- 
 charge of liquids at over 80° F. temperature is now prohibited by statute. 
 
 The general principles for preventing nuisance arising from knackeries 
 are precisely the same as those laid down for the construction and manage- 
 ment of slaughter-houses for cattle (q.v.), the cardinal point being the 
 observance of strict cleanliness. The premises must be conveniently situ- 
 ated, well lighted, ventilated, drained, and surrounded by a wall to conceal 
 from the view of the neighbours all the operations going on inside. The 
 floors should be impervious, smooth, properly guttered, and sloped towards 
 the drains. The bottom 5-6 feet of the wall should be coated with glazed 
 tiles or bricks, concrete, or other impervious material, which can be tho- 
 roughly washed with a hose and brush. The less woodwork there is the 
 Letter ; and wherever possible iron should be substituted for it. 
 
 Proper receptacles, with well-fitting lids, should be provided for convey- 
 
OFFENSIVE BUSINESSES 901 
 
 ing all garbage from, and as far as possible for conveying offensive stuff 
 to the works. Much annoyance would be avoided by the use of a suit- 
 able covered waggon and the application of deodorants. Knackers seem to 
 pride themselves on the light, skeleton-like character of their carts, which 
 should, on the contrary, be closed and substantially made. There should be 
 no dung-heap on the premises ; all such stuff should be removed daily in 
 proper vessels. If there are more carcases brought in than can be dealt 
 with in the ordinary way, they should be buried or destroyed, and must 
 not be left lying putrefying about the place. Carcases exposed to the 
 action of steam under pressure in a receptacle are soon reduced to a pulp, 
 the bones being blanched, and ready for the superphosphate maker. The 
 pulp will soon solidify and be ready for manure-making. Or such carcases 
 might be treated with oil of vitriol ; if well covered with dry earth, ashes, char- 
 coal, or other deodorant, they might be kept for days without nuisance if under 
 a shed. Carcases should not be allowed to lie exposed to the weather, but 
 should be kept under cover in a well-aerated shed. The nuisance from the 
 steam must be dealt with by having a properly fitting hood to the boiler, and 
 conducting the vapours under and into the fire, or by condensing them in a cold 
 shower-bath ; the liquor should not be run into the drains until it is cold. All 
 annoyance from the steaming meat will be stopped by placing it in cold water 
 directly it is taken from the boiler. 
 
 Boiling of Tkipe, Ox-feet, Teotters, Flesh, &c. 
 
 The preparation of these materials as articles of human food involves in 
 many cases annoyance to the neighbourhood, in consequence of want of 
 reasonable care and proper appliances, and hence it calls for the supervision of 
 the Sanitary Authority. 
 
 Tripe is the first stomach (paunch) of the ox or sheep. It is usually emptied 
 of its contents at the slaughter-house, is subsequently washed and scalded, 
 and the villous membrane is then scraped off with a knife or revolving brush. 
 The tripe is then boiled, commonly in a boiler set in brickwork, but better in 
 a pan with a steam-jacket. When cooked it is hung up to drain and cool, 
 and the liquor is run off into the drains. The fat is collected for soap- 
 making. Sometimes the boiling of trotters and ox-feet is done in conjunction 
 with that of tripe. 
 
 Ox-feet ( ' cowheels ' ), if intended for food, are first roughly dressed, any 
 adherent skin being removed (and set aside for glue-making where economy 
 is practised), and boiled, the fat being collected from the surface and used as 
 an inferior ' neat's foot oil.' Sheep's trotters, after being scalded, have the 
 hoofs taken off, and after removal of hair, loose skin, &c., are fit for boiling. 
 
 If not intended for food, the ox-feet go through a careful series of operations, 
 so as to utilise every part as far as possible. In small works there is great 
 waste, and many of the operations here referred to are entirely neglected and 
 the materials allowed to go to waste. But where proper appliances and skill 
 are available the treatment is briefly as follows : — 
 
 The skins having been stripped off are treated with lime-water to form 
 glue-pieces {vide Glue). The hoof is then slit up between its divisions and 
 the ends of the two long bones are divided. The collection of soft fat near 
 the hoof is carefully removed, being the source of the best ' neat's foot 
 oil.' The hoof is then cut off, washed, and boiled, usually in pans on an 
 open fire. After boihng for some three hours the hoofs are removed, and set 
 aside for the comb- and button-maker, &c., the oil which has been boiled out 
 being kept as an mferior ' neat's foot oil.' The smaller bones are utilised 
 
902 HYGIENE 
 
 for manure, tlie larger sliank-bones for knife-handles, and the liquor is either 
 further utilised for whatever oil it contains or run into the drains. 
 
 Sheep's trotters which are too putrid to be used for food are limed, and 
 then similarly boiled, the fat being skimmed off and sent to the soap-maker,, 
 and the residue (except the skin, which is used for glue) is variously disposed 
 of, the larger bones to the bone manufacturer, the smaller, together with hair, 
 flesh, &c., to the manure-maker. As only trotters which are in an offensive 
 state are used for this purpose, there is often a most unpleasant odour 
 produced throughout the place where the operation is carried on. 
 
 Boiling of Flesh from Horses and other Carcases 
 
 In most knackers' yards there exist arrangements, sometimes of a very 
 primitive kind, for boiling the flesh of horses and other animals which, from 
 some cause, is unfit for human food, and utilising it to make cat's-meat, to 
 produce grease, &c. 
 
 Carcases have to be disposed of in considerable numbers in all large 
 towns, and considering that many of them are in a very offensive state when 
 they arrive at the knackeries, it is not surprising that the boiling of them is 
 sometimes most offensive. The worse the raw material, the worse the nuisance. 
 
 But the knacker's yard is a necessary and most useful institution, and it 
 need not necessarily be a nuisance. 
 
 The nuisances emanating from such places arise usually from some or 
 several of the following causes : — • 
 
 (1) General filthy condition of the premises, owing to unsuitabiUty for 
 the work, and want of care in carrying it on. 
 
 (2) The accumulation of material on the premises, carcases waiting to 
 be treated, scraped bones waiting to be boiled, and bones lying in heaps after 
 boiling ; hoofs and horns, blood, scraps of skin, fat, hair, &c. 
 
 (3) The seething materials just removed from the boiler being thrown 
 on the ground and emitting stinking fumes while they cool. 
 
 (4) The fumes from the boiler in action, or while being emptied. 
 
 With regard to (1) it is absolutely necessary, if such premises are to exist 
 near inhabited localities, that they must be suitably constructed, and that 
 the business should be carried on with care. The business is generally pro- 
 fitable, and all the nuisances complained of are associated with waste and loss 
 of money. So that in insisting on the substitution, e.g. of proper steam- 
 jacketed boilers for open pans for boiling bones on the fire, one may have the 
 assurance, in spite of protests, that the business will not be ruined, but that 
 far more work will be done at a cheaper rate, in a better manner and in 
 a shorter time, and withal in such a way as to minimise or abate what 
 was a horrible nuisance. 
 
 The premises must not be too close to inhabited houses, and yet they must 
 be in an easily accessible situation, so that there may be no difficulty in getting 
 carcases conveyed there. They should be large enough for the amount of work 
 to be done, and the buildings should be suitable. Little is required in the way 
 of buildings — there must be a good boundary wall, and there should be suffi- 
 cient covered space to prevent the necessity of material being left lymg in the 
 open, exposed to the weather. The floor should be smooth, paved with some 
 suitable material, and it should be well channelled and drained. The walls 
 should be covered with a smooth coat of concrete, or plaster, or glazed brick, 
 at the lower part where there is Uabihty of their being splashed with filth. A 
 tall chimney is required with a good draught, and the boilers should be so con- 
 structed with hopper-hds or other apphance that vapour from them will be ■■ 
 
OFFENSIVE BUSINESSES QO'd 
 
 drawn up the chimney. Where there is much boihng done, and there is a 
 hability to cause a nuisance to neighbouring houses, there should be steam- 
 jacketed boilers, or means for applying free steam with a water-jointed lid, 
 and means for conducting the vapour downwards under and into the fire, so 
 as to burn it before it reaches the chimney. 
 
 (2) Nuisance under this head will need proper covered sheds, with good 
 floors ; air-tight buckets for packing waste which is to be removed ; and above 
 all a sufficient staff of workers to prevent excessive accumulation of work. 
 
 (3) There must either be means for rapidly cooling the meat (cold water, 
 cool cellaring, &c.), or else properly closed sheds communicating with the 
 chimney by means of a good air-shaft, whereby the vapour may be conducted 
 away ; the air-shaft if needful to be provided with a gas jet, or fan, or 
 other means of strengthening the draught when the chimney is not heated. 
 
 (4) There is no difficulty in obviating this nuisance, and at very small 
 expense. There are various arrangements suitable for the purpose, whereby 
 the vapours are either conducted under the fire-place and burned, or passed 
 into a tank of cold water and condensed (the residual gases being if neces- 
 sary conducted under the fire and burned), or conducted into a scrubber or 
 into some form of shower bath, where rapid cooling and condensation may be 
 effected. 
 
 Gut-cleaning 
 
 The small intestines of pigs ^ and sheep (termed ' rops ' in the North of 
 England) are used for sausage making and for making catgut. The 
 muscular and mucous layers are not required for these purposes, and their 
 removal is the work of the gut- scraper or cleaner, who leaves only the 
 peritoneal covering for the purposes indicated above. The guts are first 
 cleaned and the contents evacuated in water by a man, or water is run 
 through them from the tap, after which they are left lying in salt and cold 
 water for six to eight days or longer in cold weather, and afterwards for four 
 to five days in plain cold water until the tissues have been so softened that their 
 separation is easy. To eflect this the guts are removed from the tank and 
 placed on a table, and the gut is rubbed with the back of a knife or a piece 
 of wood, being passed along from hand to hand. It is then thrown again 
 into water. 
 
 If required for sausage skins, the gut is then simply placed in salt. Cat- 
 gut is made out of the guts thus prepared (without being salted) by sewing 
 the ends together with a needle and thread, and spinning them by an ordinary 
 spinning-wheel. The thickness of the cat-gut depends on the number of 
 strands of gut in it. The strings are usually bleached by exposure for two 
 to three days to the fumes of burning sulphur in a special chamber, after 
 which they are dried by being stretched over pegs in the open ah% but pro- 
 tected from rain and sun. 
 
 The guts are prepared for spinning by being steeped in a weak solution of 
 carbonate of sodium, which is changed twice a day during seven to eight days ; 
 and at each change they are run through a hole formed at the angle of a piece 
 of bent copper-plate. 
 
 Places where gut-spinning is carried on are, as a rule, kept in an exceed- 
 ingly offensive condition. ' Eop '-cleaning, or the preparation of sausage 
 skins, is also sometimes, but not so often, a nuisance. 
 
 In the latter case the nuisance is usually due to scraps allowed to accu- 
 
 ' The intestines of the pig average 72 feet in length, of which 56 go to the small^ and 
 16 to the large intestine. The intestines of the ox measure about 147 feet in length. 
 
904 HYGIENE 
 
 mulate and putrefy on the premises, in order to have enough to make a load 
 to send away. The water in which the guts are kept is also, at times, very 
 cfifensive. 
 
 The prevention of such nuisances is easy enough : the premises should 
 be adapted to the work, and be provided with proper stone tables and other 
 appliances ; the storage of material for any length of time should be for- 
 bidden, and what material is there should be kept in properly covered and 
 non-absorbent receptacles. The liquor should be deodorised with chloralum 
 or chlorinated soda, which may be used even when the guts are in steep, and 
 which obviates putrid fermentation. The disintegration of the tissues might 
 be accelerated by warming the water to from 80° to 89° F. 
 
 The annoyance from this business is often mainly due to its being carried 
 on in places never intended for such work. A man will commence sausage- 
 making in a small way in a private house, perhaps one of a row of workmen's 
 dwellings, without any yard or accommodation. He feeds a pig somewhere, 
 gets it killed and conveys the guts to his house to prepare the sausage-skins, 
 either in the dwelling-house, or in an improvised place in the yard, which is 
 probably hardly large enougli for the ordinary purposes of a dwelling-house. 
 "What wonder if the neighbours complain in such a case as this ! It should 
 be forbidden by law to carry on work of this kind except on duly authorised 
 premises. 
 
 The cat-gut making is almost invariably carried on so as to be a 
 nuisance, the most horrible stench pervading the place and attaching itself 
 to the person and clothes of everyone who remains in it even a short time, 
 and spreading to a considerable distance around the premises, which them- 
 selves become saturated with stench. 
 
 Still, there are many who will maintain that health is not injured by the 
 nuisance. It is no doubt possible for persons to become acclimatised to such 
 an atmosphere, but for the average man it cannot be regarded as healthy, 
 and sanitary regulations must be framed with a view to the average man. 
 
 The building must be adapted to the trade, and be properly situated, at 
 a convenient distance from dwelling-houses. The more offensive work should 
 be carried on in a closed chamber, with active artificial ventilation, and an 
 arrangement for driving the foul air through the fire, so as to burn it before it 
 escapes into the atmosphere. The floors should be constructed of concrete 
 or flags, or other suitable material, and properly sloped to the drain, and the 
 walls should be also concreted or plastered or otherwise rendered impervious to 
 a height of five to six feet. There should be an abundant supply of water, and 
 a hose kept for swilling the place. 
 
 But nothing will prevent a nuisance unless care be continually exercised 
 to keep the place clean, and never to allow filth to accumulate. The cleans- 
 ing of it must be frequent and thorough. 
 
 No accumulations of stinking material should be tolerated on the 
 premises, and there should be proper vessels for conveying material to and 
 from the place. 
 
 Utilisation of Blood 
 Manufacture of Blood Albumen 
 
 The albumen is prepared by desiccating the serum, from which the clot 
 has been separated. For the purpose of this trade the blood must be fresh ; 
 hence there is no offensiveness essentially connected with it. 
 
 The serum contained in the clots is drained off' by slicing the clots, 
 •which are placed on a strainer above a pan, so situated as to catch the serum 
 
OFFENSIVE BUSINESSES 905 
 
 as it oozes from the contracting clots, a process which lasts from twelve to 
 twenty-four hours, according as the weather is hot or cold. When a high- 
 class albumen, free from colour, is required, this reddish serum is transferred 
 to a cask and allowed to stand until the red colouring matter has subsided. 
 Inferior, coloured albumen is prepared by drying the albumen without wait- 
 ing for it to settle. The drying is effected in shallow iron pans placed in a 
 room heated to about 120° F. The clot is commonly used for manure- 
 making. 
 
 This trade is now commonly carried on in connection with large public 
 abattoirs, and where there are space and cleanliness there is no nuisance. 
 But if the premises be small and in a crowded district, and if reasonable care 
 be not exercised, and especially if blood from other sources besides that from 
 animals slaughtered on the premises be collected and be utilised for manure- 
 making, there may be complaints of a nuisance. The complaints are usually 
 owing to old material (clots, &c.) retained on the premises until it is putrid, 
 and from a general unpleasant smell which pervades the place, if not kept 
 perfectly clean. 
 
 When not directly used for manure-making, &c., on the premises, the 
 clot should be put in proper air-tight receptacles, and removed as soon as 
 possible. It should never be allowed to accumulate in the yard, and there 
 should be no dung-heap on which to throw it, except what may be collected 
 from day to day. 
 
 The premises should be kept scrupulously clean, especially the floors, which 
 should be of impervious material, as they are liable to be splashed with blood. 
 It is difficult to keep the divisions between flag- stones thoroughly water-tight ; 
 hence concrete is better. The yard, too, should be well paved and drained. 
 The clot-room and the drying-room should be effectually closed on all sides, 
 and be lighted and ventilated from the roof. The most effective way would 
 be to draw off all the air by a fan into the furnace, through which it would 
 pass into a tall chimney. All the implements and appliances used in the 
 business must be kept thoroughly clean. 
 
 Blood Manure 
 
 Blood-clot is sometimes utilised by being mixed with an acid, usually brown 
 sulphuric acid (rarely hydrochloric acid), desiccated, pulverised, and mixed 
 with other materials such as superphosphate, scutch manures, &c. The blood 
 is thoroughly mixed with the acid, and stirred until the whole is reduced to the 
 ■consistence of porridge. It is then dug out and allowed to dry in the air, which 
 takes three to four days in summer, and rather longer in winter. It musi 
 of course be protected from the rain. Sometimes it is dried by artificial heat 
 on a floor heated by steam, which is much more Hkely to cause nuisance. 
 While it is drying a certain amount of red acid liquid drains off, which may 
 be utilised in the succeeding operations. 
 
 Apart from nuisance arising from filth allowed to accumulate on the 
 premises, there is little to complain of in this business, except during the 
 mixing of the blood and acid, when very offensive vapours are given off, 
 and during drying by artificial heat. The former operation should be con- 
 ducted in a covered chamber, the vapour from which should be conducted 
 under and into the fire, or into water. The drying should always be effected 
 either spontaneously in the air, or by steam, and never by direct fire-heat, 
 as it is difficult to avoid a horrible stench fr'om overheating the parts next 
 the fire. 
 
906 HYGIENE 
 
 Blood-boiliiig and Drying 
 
 The clot from albumen works, and blood which has become too putrid for 
 making albumen is sometimes desiccated on a floor heated artificially, or in 
 a boiler by direct fire-heat. The latter method is almost certain to cause a 
 nuisance, by over-heating the blood. Whichever process is used, the vapour 
 should be conducted by a hood and flue, under and into the fire, before being 
 discharged into the air. Or in some cases it may even be necessary to pass 
 it first through a cold-water condenser, to absorb part of the vapours and 
 gases. 
 
 Preiiaration of Blood for Turkey -red Dyeing 
 
 Before the introduction of alizarin, cotton dyers used madder, and its 
 commercial preparation garancine, to produce the red colour known as 
 turkey red, remarkable for its brilliancy and fastness both to light and boil- 
 ing alkaline solutions. 
 
 Alizarin, formerly only known as a substance obtainable from madder 
 root, is now made in large quantities from the coal-tar product, anthracene, 
 and has almost entirely displaced madder, as the colours it produces are far 
 more brilhant, quite as fast, and less expensive. Bullock's blood is used to 
 fix the ahzarin on the cotton, by the coagulation of its albumen. 
 
 The blood is prepared first by collecting the serum which has already 
 separated from the clot, residual serum being extracted from the clot itself 
 by placing it on a strainer above the vessel and slicing it, and subsequently 
 treating the clot with water, which is allowed to run into the reservoir with 
 the serum. The clot itself is then rubbed up with water, and strained into 
 the remainder of the liquor, and the whole is then put in barrels for use. 
 
 As the blood is usually more or less putrid during the whole of these 
 operations, a horrible stench is produced, which may be perceived a long 
 way from the works. 
 
 The nuisance may be obviated by conducting the operation in a closed 
 chamber pronded with a suitable flue to carry off the vapours fi'om the 
 place where the work is carried on, and the use of a fan to convey them 
 under and into a fire, connected with a high chimney. 
 
 It is at the same time essential that scrupulous cleanliness be observed 
 on the premises, that the floor be constantly cleansed from all blood which 
 has fallen on it, and that all the utensils be kept sweet. The place where 
 the work is carried on must be well closed in, and not exposed to the action 
 of the wind, or else the ventilating fan cannot act effectively. 
 
 The following is an abstract of the bye-laws framed by the London 
 County Council, under the Slaughterhouses &c. (Metropolis) Act, 1874, 
 for the regulation of the business of a blood drier, and any business m which 
 blood, or any constituent parts of blood, is used, provided that heat be in any 
 way applied or used to the same : — 
 
 1. Every blood drier shall cause all blood brought upon his premises to be brought 
 in closed vessels or receptacles constructed of galvanised iron or other non-absorbent 
 material. 
 
 2. Every blood drier shall cause every process of his business (except the drying 
 and packing processes to be carried on in a building properly paved with asphalte, 
 concrete, or other suitable jointless material, having walls covered to the height of at 
 least six feet, with hard, smooth, and impervious material. 
 
 3. Every blood drier shall cause every process of his business in which any offensive 
 
OFFENSIVE BUSINESSES 907 
 
 effluvia, vapours, or gases are generated, to be carried on in such manner that no offensive 
 effluvia, vapours, or gases shall escape into the external atmosphere ; and he shall cause 
 all such offensive eflluvia, vapours, or gases to be eflectually destroyed. 
 
 4. Every blood drier shall cause all blood, blood-clot, or any refuse, residue, or other 
 matter from which offensive effluvia or vapours are evolved, or are liable to be evolved, 
 to be placed in properly closed receptacles, or to be otherwise dealt with in such 
 manner as to prevent any offensive efHuvia or vapours therefrom escaping into the 
 external atmosphere. 
 
 5. Every blood drier shall cause the floor of every place in which any process of the 
 business (except the drying and packing processes) is carried on to be thoroughly cleansed 
 with water at least once in twenty-four hours ; and he shall cause the premises to be 
 constantly provided with an adequate supply of water for the purpose. 
 
 6 Provides for the periodical cleansing of the premises, and 7 provides for the due 
 and frequent cleansing of the vessels used. 
 
 11. Every blood drier shall cause the floor of the yard and every part of his premises 
 in which any process of his business (except the drying and packing processes) is carried 
 on, to be properly paved with asphalte, concrete, or other suitable jointless material, 
 laid upon a suitable bottom of at least four inches in thickness, and such floor to have a 
 proper slope towards a channel or guUey ; and shall cause his premises to be effectually 
 drained by adequate drains communicating with a public sewer. The drains shall be 
 properly trapped, and the entrances thereto shall be covered with fixed gratings, the 
 bars of which shall not be more than three-eighths of an inch apart. 
 
 13. Every blood drier shall cause his premises to be provided with appliances 
 capable of effectually destroying all offensive effluvia, vapours, or gases arising in any 
 process of his business, or from any material, residue, or other substance which may 
 be kept or stored upon his premises. 
 
 PISH-FEYING 
 
 The frying of fish for sale, ready-cooked, is a business that gives rise to 
 many complaints. The trade exists almost entirely for the poorer class, 
 and hence the shops are usually, but by no means invariably, situated in 
 poor thickly populated streets. The complaints do not generally come from 
 the poor for whom the trade is carried on, but from persons living at a 
 little distance, whom the effluvia from the chimney may reach, or from 
 persons who are in the habit of frequently passing the premises. 
 
 The smell is often very unpleasant. The nuisance is sometimes intensi- 
 fied by the continued use for a considerable time (many weeks) of oil in 
 which fish is constantly being cooked. 
 
 The cookmg commonly consists in ordinary frying, when the oil is in a 
 constant state of effervescence [the oil itself being rarely boiled ; it is the 
 water in it which is raised to boiling point, and causes the phenomenon 
 commonly, but erroneously, called 'boiling].' Particles of the oil escape, 
 with bubbles of water escaping from it, and spread the smell, and as the oil, 
 as well as part of the fish are usually partially burned from the cooking 
 on the open fire, strong empyreumatic odours are produced. 
 
 If oil at a high temperature were used, as is so common m France, to 
 cook the food at a high temperature (without the food itself being browned 
 or burned by actual contact with the hot pan), the cooking would be much 
 more effective, and it would make the food much more palatable, and at the 
 same time the burning which causes much of the nuisance would be avoided. 
 
 The fact that the cooking is usually carried on on the open fire, in the 
 open shop, and subject to draughts of wind, causes the effluvia to be blown, 
 about in all directions. 
 
 The use of a deep vessel of oil (six to ten inches of oil according to re- 
 quirements), kept at a high temperature, in which the fish could be cooked, 
 without burning, and the addition of a hopper above to carry off the effluvium 
 into a high chimney, will generally put a stop to all nuisance. A good gas- 
 
908 HYGIENE 
 
 burner may be required to increase the draught up the pipe from the hopper. 
 The cliimney must be high enough to conduct the vapours above neiglibouring 
 houses. If further steps are required, the vapours may be conducted under 
 the fire, and obhged to pass through it, which will lead to their combustion, 
 or they may be conducted through water. After washing the vapour there 
 seldom remains any offensive smell. 
 
 The cooking vessel should also be provided with a well-fitting lid, which 
 can be easily raised and lowered, and provided with a suitable opening to 
 enable the cook to inspect the interior at will. 
 
 GLUE 
 
 This important article is made from almost every kind of waste animal 
 tissue ; it is chiefly obtained from bones (after the fat has been extracted by 
 boiling), hoofs, horns, scraps cut off during the preparation of skins for 
 leather, scraps of leather, parchment, &c. The raw material which hag 
 not already been limed (leather is differently treated) is first limed, and then 
 washed, boiled, and stirred for some hours in a vessel with a false per- 
 forated bottom (to keep the material from burning at the bottom). The thick 
 fluid is drawn off after it has cooled, and is allowed to settle into a second 
 receptacle, where it continues to stand and further clear. The use of super- 
 heated steam is a great improvement on this method, giving a better return 
 in a shorter time. After a time the liquor is drawn off into wooden boxes, about 
 14 ft. X 12 in. X 9 in. deep, in which it cools in the course of twelve to 
 eighteen hours. The glue is then removed from the boxes, placed in wooden 
 frames and cut into slices to dry, during which latter process it shrinks to 
 about half its bulk. 
 
 When scrap leather is used it is treated with slaked lime and water at a 
 high temperature (about 250° F.) By this means the leather is decomposed, 
 the tannin combines with lime, and the gelatine becomes dissolved in the 
 water. Glue made in this way is of inferior quality. 
 
 Glue which has become foul during preparation has the curious and un- 
 pleasant property of recovering its evil odour long afterwards, when in use 
 on walls, wood, &c., if it becomes moist. Size is made in the same way as 
 glue, only from better material and with more care ; it may be cheap and 
 little superior to glue in quality, or of very superior quality, such as is 
 used for making gelatine and isinglass. It is sold both in the solid and 
 liquid form. The latter is commonly nothing but a very dilute solution of 
 glue. But a cheaper and better article is now largely used, made from 
 powdered resin dissolved in a warm aqueous solution of soda. 
 
 The manufacture of glue is often attended by great nuisance, though not 
 necessarily so. The nuisance most frequently complained of is the smell 
 from the hot pans. The character of the material used has a great deal to 
 do with the nuisance, old foul scraps causing a penetrating, acrid odour, very 
 different from that arismg from good fresh material. Besides this effluvium, 
 nuisance may arise from the general filth of a badly managed place, where 
 decomposing organic matter is allowed to collect on the ground, or to adhere 
 to the walls and the thousand places where dirt can accumulate. The debris 
 from the vats, after the glue has been drawn off, commonly known ag 
 ' scutch,' is a fruitful source of nuisance when allowed to accumulate. The 
 sooner it is barrelled and removed the better. Should delay unavoidably 
 occur in doing this, the scutch will be best kept in a dry, airy place ; for 
 it is very likely to putrefy and become offensive if kept exposed to the 
 
OFFENSIVE BUSINESSES 909 
 
 vicissitudes of our climate. Carbolic powder sprinkled over it is a useful 
 protective. 
 
 There is often mucli nuisance produced by accumulations of raw material 
 on the premises before use. This may, without injury, and with the best 
 prospect of avoidance of nuisance, be stacked, each layer of a few inches 
 thick being well covered with milk of lime. This material must not be 
 exposed to damp, otherwise putrefaction and stench (as well as destruction 
 of valuable material) must certainly ensue. 
 
 The stench from the boiling process is always worst where open fires are 
 used ; hence heating by steam is to be recommended as a preventive, and as 
 probably a more economical method. The vapour may be conducted under 
 and into the fire, and burned, or into a scrubber, where it would be washed 
 and condensed. It should always be at last conducted into a tall chimney. 
 
 The after-treatment of the ' scutch,' to remove the fat from it, deserves 
 notice. It is usually treated with hot water, or cold water with steam, and 
 the fat skimmed off, the residue being pressed in coarse canvas to extract the 
 last remnants of grease. The cake is used for manure. If kept dry and under 
 cover, it will keep inoffensive for some time; but if allowed to accumulate 
 in the open air, it soon becomes offensive. 
 
 EECOVEEING GEEASE FEOM SOAP SUDS' 
 
 In districts where the manufacture of wool is carried on there is often' 
 annoyance caused by the warm suds produced in washing the wool, some 
 kinds of which are very greasy ; as well as by the efforts to utilise the 
 wool-fat (' suint ') and the large quantities of soap which are employed in 
 the washing. 
 
 This was at one time a large and profitable business, but for some years 
 past has declined. In many large wool works the grease is recovered and 
 converted into soap on the premises, and one lot of wool is actually washed- 
 with soap extracted as an impurity out of a preceding lot. 
 
 But some persons make a special business of recovering the grease, and 
 for this purpose collect the suds from several wool-washing places. The 
 liquid is roughly strained as it passes into a large tank (v/hich is sometimes 
 heated by steam), when sulphuric acid is added, and mixed with it in 
 sufficient excess to slightly acidify the liquor. The acid combines with the 
 soda, potash, and other alkalies present in the soap and wool-fat, and the 
 grease being set free rises to the top as a dirty scum known as ' magma.' 
 The liquor is then run off from the bottom, usually direct into the drain, 
 and the magma is either collected directly on coarse canvas, through which 
 it drains, or it is removed and allowed to drain in a hole in the ground m 
 the open air. Afterwards, and while still wrapped in the canvas (called 
 ' bags '), it is put in a press and is squeezed while heated by steam. The 
 grease and some water and dirt escape from the bottom into a tank, where 
 the grease again separates and floats, and is ladled out into a vessel, in 
 which it is again treated with sulphuric acid to remove the water, after which 
 it is put in barrels for sale either to be further purified or to be used for 
 common work. The residue in the ' bags ' is commonly used as manure, or 
 thrown away. Sometimes it is further treated with bisulphide of carbon, 
 and a profitable business may be done in recovering the residue fat by this 
 interesting process. The cake to be treated is first ground in a mortar-mill 
 and then placed in a cylinder containing the bisulphide, which dissolves 
 ' Cf. Article on Manufacture of Soap, p. 912. 
 
910 HYGIENE 
 
 every trace of fat. Steam is then let into the cylinder and separates the two, 
 the fat being run off by one tap and the bisulphide retained to be used over 
 again. There is but small loss of bisulphide at each operation, and this is 
 made good by the necessary addition of more, and the process is kept in 
 constant operation. 
 
 This process is exceedingly dangerous, owing to the inflammable nature 
 of the bisulphide. No light must be burned inside the building where it is 
 used. The plan adopted is to have the chamber where the operation is 
 carried out carefully boarded off, the partition having windows in it, outside 
 of which are placed the gas-lights. This bisulphide process is carried 
 on at Frizinghall, a suburb of Bradford, Yorks., without the shghtest 
 nuisance. 
 
 The nuisance complained of in treatmg the suds is from offensive smells, 
 due to putrefaction from over-keeping. This can only be prevented by the 
 avoidance of this unnecessary practice. The warming of the suds by steam 
 accelerates the work, and the adoption of this plan would undoubtedly assist 
 in getting rid of objectionable material more rapidly and preventing nuisance. 
 The press is also liable to cause offensive smells, but only to a shght 
 extent, and chiefly in hot weather. The discharge of the acid liquor into 
 the sewer is alleged, but hardly on sufficient grounds, to greatly increase the 
 evolution of offensive gases (sulphuretted hydrogen) from the sewers. When 
 the liquor smells offensively, it may be deodorised by the addition of proto- 
 sulphate of iron (about 20 lb. of the salt to 1,000 gallons of the liquor). 
 
 DIP-CANDLE-MAKING. PAT-MELTING 
 
 These associated processes are still carried on in almost all large towns, 
 notwithstanding the general use of gas, illuminating oils for lamps, and the 
 immense trade in candles from wholesale manufacturers, which the great 
 cheapness of traffic allows to be retailed in the smallest village at a moderate 
 price. 
 
 Fat-melting is required for the purpose of making soap, waggon-grease, 
 candles, and other purposes. The materials used are chiefly beef, mutton, 
 and pig fat, kitchen-waste, dripping, fat collected from plates and dishes, 
 and waste meat ; also the scraps of meat, fat, &c., collected by itinerant 
 rag-and-bone men, and not mfrequently inferior stuff' obtained from the 
 boiling down of bones and scraps at knacker-yards, tripe- and glue-boiling 
 works, &c. 
 
 Tallow is either mutton or beef fat, or a mixture of both, usually prepared 
 by heating crude fat in contact with water or steam until the membranous 
 covering in which the fatty matter is encased swells and bursts ; after the 
 whole has cooled, the membranous covering is found between the water and 
 the superjacent tallow. Lard is pig's fat similarly freed from its membranous 
 covering. ' Moulds,' i.e. candles shaped in moulds, are made of mutton suet. 
 'Dips,' or inferior candles, are made by dipping a wick into the molten 
 fat, made from inferior tallow, and repeating the process until the candle is 
 sufficiently thick. 
 
 Chevreuil, who carefuUy investigated the subject of the chemistry of fats, 
 has shown that the ordinary commercial neutral fats are to be regarded as 
 chemical ' salts,' in which glycerine forms the base in combination with one 
 of various fatty acids. When a neutral fat is boiled or ' rendered,' in the 
 ordinary way along with soda, lime, or other strong alkali, the latter displaces 
 the glycerine and combines with the fatty acids, forming a soap. 
 
 When, as happens in certain processes, the soap is ' broken ' by the 
 
OFFENSIVE BUSINESSES 911 
 
 addition of a strong mineral acid, e.g. sulphuric, the latter combines with the 
 alkali, and the fatty acids are set free. 
 
 The usual mode of melting fats, derived from the various sources men- 
 tioned above, is simple in the extreme : the fat is placed in a pan, usually set 
 in brickwork over an open fire, and is stirred from time to time. 
 
 When ' raw ' fat direct from the carcase has to be melted it is usual 
 to chop it up to facilitate the melting, and thus in some degree to obviate the 
 danger of burning it ; but when it is treated with sulphuric acid and steam 
 it is rarely chopped. When steam is used direct, it is conducted by a pipe 
 down to the bottom of the boiler filled with fat. 
 
 The melted tallow is either run off through a tap, or ladled out by hand 
 into a vessel in which it is allowed to settle ; it is advantageous, but excep- 
 tional, to ladle it through a strainer. 
 
 The residue, after all the tallow has been removed, consisting of scraps of 
 membranes of various kinds, sinew, skin, &c., is with advantage squeezed 
 through a press to extract all remnants of fat, and the remaining solids, 
 known as * greaves,' are commonly used for manure, or, if of better kind, as 
 food for animals. 
 
 Apparatus of various kinds has been devised for the rendering of lard to 
 make the process more expeditious and economical. In some methods these 
 objects have been successfully combined with the suppression of nuisance. 
 
 The great secret in preventing nuisance is the avoidance of burning the 
 materials, or even raising them to a high temperature. The lower the 
 temperature at which the work can be successfully carried on, the less is the 
 risk of the production of offensive smells. The temperature need not exceed 
 about 120° F. It is in summer weather that nuisance is most complained of ; 
 the time when most people are liable to feel easily annoyed by even the smells 
 of ordinary domestic cooking. ' Heavy ' damp weather, too, is likely to make 
 the smells hang about the neighbourhood and cause offence. 
 
 The fresher and sweeter the materials used, the less is the danger of 
 nuisance during the melting. A little care in keeping the fresh materials 
 would often prevent loss and nuisance ; a cool, well-aerated room is the best 
 place to keep it till wanted. The general principles of preventing nuisance 
 from this trade are the same as those mentioned in the sections on tripe- 
 boiling, &c. The nuisance arising from the pressing of the ' greaves ' is 
 sometimes rather troublesome to overcome, but by conducting the operation 
 under cover, the whole apparatus being, if necessary, boxed in, and by 
 operating in a closed room where there is a good draught into the chimney, 
 all nuisance may be completely suppressed. 
 
 Unless fat-melters will adopt proper precautions, they should be obliged 
 to remove from populous districts. 
 
 General cleanliness, the use of good material, melting at a low tempera- 
 ture, and the use of steam and acid are the cardinal points to be attended to 
 with a view to conducting this business without nuisance. 
 
 The following are extracts from the bye-laws in force for the regulation of 
 these businesses in the metropolis : — 
 
 1, Every fat melter or fat extractor shall cause every process of his business in which 
 any offensive eifluvia, vapours, or gases are generated to be carried on in such manner 
 that all offensive efauvia, vapours, or gases shall be effectually destroyed. 
 
 2. Every fat melter or fat extractor shall cause all material used or offensive material 
 or refuse from the boiling pans, and all refuse, residue, or other matters from which 
 offensive effluvia, vapours, or gases are evolved, or are liable to be evolved, to be placed 
 in properly closed receptacles, or to be otherwise dealt with in such manner as to prevent 
 any offensive effluvia, vapours, or gases therefrom escaping into the external atmosphere. 
 
912 HYGIENE 
 
 3. Every fat melter or fat extractor shall cause all scraps or litter composed of matters 
 liable to become decomposed to be constantly gathered or swept up and placed in properly 
 covered receptacles. 
 
 4. Every fat melter or fat extractor shall cause the floor of every place in which 
 any process of the business is carried on to be kept thoroughly cleansed, and he shall 
 cause the premises to be constantly provided with an adequate supply of water for the 
 purpose. 
 
 5 Orders the proper and periodical cleansing of the premises, and 6 the due cleansing 
 of the premises. 
 
 10. Every fat melter or fat extractor shall cause every floor upon which any process 
 of his business is carried on, in any part of his premises, to be properly covered with 
 a layer of concrete, or other suitable jointless impervious material, laid (in the case of 
 a ground floor) upon a suitable bottom of at least four inches in thickness. He shall 
 cause every such floor to have a proper slope towards a channel or gulley, and shall 
 cause every part of his premises wherein any such floor may be constructed to be 
 effectually drained by adequate drains communicating with a public sewer. He shall 
 also cause every drain to be properly trapped, and the entrance thereto to be covered with 
 a fixed grating, the bars of which shall not be more than three-eighths of an inch apart. 
 
 11. Every fat melter or fat extractor shall cause his premises to be provided with 
 appliances capable of effectually destroying all offensive effluvia, vapours, or gases arising 
 in any process of his business, or from any material, residue, or other substance which 
 may be kept or stored upon his premises. 
 
 MANUFACTUEE OF SOAP' 
 
 This business has a sanitary interest, not so much on account of the soap 
 itself as of the fats from which it is usually made, and the melting of which 
 is often, though by no means necessarily, a source of nuisance. 
 
 The ordinary neutral fats must chemically be regarded as ' salts,' i.e. a 
 combination of a base with an acid, glycerine being the base, and a fatty 
 acid the acid. In soap-making, saponification, i.e. in the chemical actions 
 resulting from the interaction of an alkali (soda, potash, &c.) and a neutral 
 fat (tallow, &c.), the glycerine is displaced as the base, and its place is taken 
 by the alkali. 
 
 Although it is theoretically true that all combinations of fatty acids 
 with a mineral base form soaps, in practice we need only consider those 
 which are found with soda and potash, as these, being soluble in water, 
 are the only ones used for detergent purposes. 
 
 Soaps are divided into two classes, ' hard ' and ' soft,' according to their 
 physical characters. Soft soap almost invariably has potash as its base, and 
 as it retains moisture, and absorbs it from the air, it is soft and pulpy, 
 while soda soap, or ' hard ' soap, dries and becomes hard in the air. 
 
 Fats of all kinds are used,^ chiefly tallow, either pure butcher's tallow, or 
 that collected in the treatment of skins, trotters, bone-boiling, and glue- 
 making, also kitchen refuse, grease from wool-washing, &c. What may be 
 termed the natural ' mottled ' soap is due to decomposition of small portions 
 of the soap owing to the unavoidable presence of negligible quantities 
 of impurities, e.g. metallic oxides and earths. These form corresponding 
 quantities of insoluble soaps, which are diffused throughout the general 
 body of the material durmg ' boiling ' and produce the mottling. Slight im- 
 purities in the fat itself cause a similar effect. Blue, grey, and red mottled 
 soaps are modern devices to please the eye only. These soaps are silicated, 
 i.e. made with soluble silicates of sodium and potassium ; the blue motth'ng 
 
 ' Cf. Article on Eecovery of Grease from Suds, p. 909. 
 
 - Soap is also made from rosin (the kind known as colophony), which regarded 
 chemically is an acid, which combines with the caustic alkali when added to carbonate of 
 soda. It is, however, always used for soap in combination with fats. 
 
OFFENSIVE BUSINESSES 915 
 
 is produced by admixture of artificial ultramarine, grey by finely levigated 
 oxide of manganese. 
 
 The soap is usually made in large iron pans, set in brickwork, in which 
 the fat, oil, or mixture of both is placed, and heated either directly by fire 
 or, better, by free steam (i.e. discharged directly into the pan) or by inpes 
 heated by steam. A little of the fat is first introduced, then some weak 
 caustic lye (sp. gr. 1'05 to 1"08) ; the mixture is well stirred, and then more 
 lye of a greater strength is added, and then more fat, and more lye, the boiling 
 being continued until the materials have been introduced in proper propor- 
 tions. The whole is carefully stirred, and samples are withdrawn from time 
 to time for examination. By the addition of common salt (about 10 lb. to 
 100 of fatty matter) the soap is separated from the Hquor in the vessel 
 (being insoluble in strong saline solutions) and floats nearly dry and pure 
 on the liquor. At this stage either the liquor is run off from below, or the 
 soap is drawn off from the top. The soap is again treated with alkali and 
 heated, and after the liquor has been run off it is placed in frames of suit- 
 able size, in which it cools and sets, after which it is cut by means of wires 
 drawn through it into bars or blocks. It usually contains a slight excess of 
 alkali. 
 
 Soft soap is made on the same principle as hard, potash, as already ex- 
 plained, being the base used instead of soda. The potash is boiled with linseed,, 
 cotton, whale, fish or other oil, alone, or mixed with other oils or some tallow 
 (which gives a speckled appearance). A weak lye is added and well stirred 
 with the oil, forming a viscous compound. Stronger lye is then added, and 
 the boiling is continued, excessive foaming being prevented by breaking up the 
 foam as it forms until the soap has attained the proper degree of viscidity 
 and transparency. This soap contains all the ' liquor ' used during its 
 manufacture, as it is not separated by salting, as described above. 
 
 The offensiveness arising from this manufacture is practically Hmited to 
 the manipulation of the fats. Some kinds of oil when heated are very un- 
 pleasant in smell, especially common kinds of fish oil. So, too, is some of 
 the fat obtained from ships' cooking-galleys, and even kitchen stuff and 
 butcher's fat is not always fresh, and indeed the melting of fats is generally 
 unpleasant, unless conducted with care. 
 
 Nuisance from these causes can be obviated by conducting the melting 
 at the lowest possible temperature, by using pans or boilers with properly 
 fitting lids, connected by a pipe with the chimney, or, if need be, by con- 
 ducting the vapours under and into the fire or into water, the lid of the pan 
 having a door through which the boiling can be superintended. The pre- 
 cautions same as those required for fat-rendering. 
 
 BONE-BOILING 
 
 Bone-boiling is carried on either for the extraction of fat and gelatine, or 
 for the ulterior utilisation of the bones themselves, or with both objects in view. 
 
 Bones from knackers' yards, butchers' shops, refuse bones collected by 
 ' rag-and-bone men,' bones from animals which have been killed or have 
 died, &c., are collected at the bone-boiler's, and there treated. 
 
 The ' raw ' material varies from perfectly fresh to foul and stinking 
 material, and the character of the effluvium evolved in the manufacture 
 depends largely on the freshness or putridity of the material used. The 
 bones are generally roughly broken up, to allow any marrow to be readily 
 boiled out. The boiling is usually done in open iron boilers, set in brick, 
 
 VOL. I. 3 N 
 
D14 HYGIENE 
 
 and is done under cover or in the open air. The heat is appHed either 
 by open fire or by steam, and the operation is continued until it is 
 thought all the fat is extracted, which in inferior boilers will take five 
 to twelve hours, and then the fat is skimmed off, and the bones are commonly 
 thrown on the ground to cool, during which cooling process very offensive 
 efflu\'ium is frequently given off. If size is to be extracted the boihng is 
 prolonged for four to five days and nights. In larger works there is often a 
 closed chamber, called a ' bone hole,' into which the bones are thrown and 
 left till cool. If bones of a superior kind are under treatment they are 
 generally thrown into cold water to cool, so as to preserve their colour and 
 quality, and make them fit for making buttons, handles for knives, small 
 spoons, &c. Superheated steam, at about 28G° F., will thoroughly extract 
 every particle of fat from a charge of bones in less than an hour ; but the 
 bones are subsequently only fit for manure. 
 
 The liquor from bones which have only been boiled for a short time, to 
 extract the fat, is usually discharged direct into the nearest drain or stream, 
 at a temperature which must be below 80° F. ; but when the boiling has been 
 continued with a view to size-making, the hquor is further boiled and con- 
 densed to a proper consistency, after which it is barrelled for sale. 
 
 The process is a common source of complaints arising from the offensive 
 effluvium. The fact that the process may be continued for so long as four 
 to five days, when size is made, is liable to make it unpleasant to neighbours, 
 even where the smell is not what may be termed a very offensive one. But 
 the unceasing smell of cooldng, even of the finest kind, in a private kitchen 
 finally becomes unpleasant to most persons. And at best the mawkish smell of 
 meat-boiling without salt is not pleasant. The presence of even a little salt 
 makes the odour much less unpleasant in ordinary meat-boiling, but it would 
 not be possible to use it, some say, in bone-boiling. But when putrid bones 
 are boiled, the evil is enormously aggravated, and reaches a maximum in hot 
 or close weather. 
 
 This effluvium is to be treated like that arising during fat-boiling, &c. 
 The importance of a sufficiently high chimney through which the vapours 
 may be discharged is here greatly increased. The rationale of this is that 
 vapours diffuse so rapidly in the air that they do not reach the ground in a 
 sufficiently condensed form to prove a nuisance. For a similar reason large 
 airy sheds are an important means of mitigating nuisance, not only by 
 mechanically restraining the escape of the offensive vapours, but also by 
 giving them time to be well diluted with air before they are discharged into the 
 atmosphere. The passing of vapours under and through the fire, and the con- 
 densing them in water, will also be found available means of abating nuisance. 
 A cheap and effective form of condensing apparatus may be made by means 
 of ordinary drain-pipes, containing coke in lumps, kept cool and wet by water 
 allowed to run in a small stream through it. The offensive vapours are 
 conducted into this condenser, being forced by a fan, &c., if needful, and are 
 found at the outlet to be almost entirely deprived of their offensive character. 
 
 The drying of the bones may be effectually done in a well-closed chamber 
 through which a draught is maintained into the chimney ; or else by arti- 
 ficial heat created by charcoal or coke fires ; or by a short sojourn in the 
 boiler, after the liquor has been withdrawn, the heat being maintained by 
 the steam pipes. Of course there would have to be the same means of 
 carrying off and dealing with the vapour from the bones drying in the 
 boiler as with that arising from them while they were being boiled. Almost 
 any method is preferable to the ' bone-hole ' whence intolerable stench is 
 liable to escape. 
 
OFFENSIVE BUSINESSES 915 
 
 FELLMONGEEING AND LEATHEB-MAKING 
 
 The preparation of skins to make leather is important from a sanitary 
 point of view. It may be effected so as to be harmless and inoffensive, if 
 great care be exercised ; or, on the other hand, it may be carried on so as to 
 be a great and offensive nuisance, causing intolerable stench to spread to 
 a considerable distance, and annoying those who live on either side, according 
 to the direction of the prevailing wind. 
 
 Like every other process involving the treatment of more or less offensive 
 materials, leather-making has found champions to declare it a panacea for all 
 sorts of evils, and in particular it has been described as a preventive as well 
 as a cure for phthisis ! 
 
 But the mere fact that many robust, healthy men may be found engaged 
 in the trade is no proof whatever that it is healthy ; it would be quite suf- 
 ficiently accoimted for by the fact that the work is severe, and could only be 
 ■carried on by robust, healthy workmen. Again, the statistics of Beaugrand, 
 who found among 171 cases of disease occurring among ^ leather- workers ' 
 28 of pulmonary phthisis, are worthless as a general statement. The figures 
 are too small, and the definition of the work too vague, to be of the least 
 value. 
 
 Tanning, or the process of leather-making, is in its final processes a 
 chemical preparation of the skin, and in one sense may be regarded as a 
 kind of dyeing, when we consider the mode in which the tanning agent 
 penetrates the skin and attacks its individual fibres. The power to precipitate 
 solutions of albumen and glutei! is characteristic of substances which can 
 convert skins into leather. The conversion into leather prevents skins from 
 putrefying ; and altogether the process must be regarded, as described by 
 Knapp, as being one. in which the fibres do not cling together in drying. 
 
 Leather-making consists of two chief stages : (1) ' tanning ' proper, or 
 the conversion of the raw putrescible hide into an imputrescible and more 
 or less flexible material known as leather, and (2) ' currying,' in which by 
 treatment with fatty and other matters the leather is rendered more soft, 
 supple, and waterproof, and improved in appearance. 
 
 Soft materials, such as glove kid, are not tanned, but ' tawed,' in which 
 process treatment with alum and salt is the chief means employed. Some- 
 times skins are merely treated in a rough way by inunction with fatty 
 matter, and are thus rendered less liable to putrefaction, though they usually 
 retain a ' strong,' unpleasant smell. 
 
 Enamelled, patent, or japanned leathers are finished with a bright, var- 
 nished, waterproof surface on one side. The terms patent or japanned are 
 generally used when the surface is smooth and bright, while ' enamelled ' is 
 the term used when the surface is grained or roughened. The artificial sur- 
 face consists of coatings of a sort of paint, consisting of lampblack, Prussian 
 blue, and linseed oil, ground together and applied in several layers, each of 
 which is dried in an oven at about 160°-170'' F. Each coat when diy is 
 rubbed smooth with pumice-stone ; and after the last one has been so 
 treated a coat of oil varnish is applied, and afterwards dried in the oven. 
 
 Morocco leather is properly made from goat-skins. After being unhaired 
 in the usual way the skins are bated with dog's dung and water, and are 
 tanned chiefly with sumach. The grain or polish is given by working under 
 rollers or boards. 
 
 Bussia Leather. — The skins for making this leather are bated, after 
 liming, with a drench of rye, oatmeal, and salt, or with dogs' dung or sour 
 
 3n2 
 
916- HYGIENE 
 
 liquors. They are again treated, after tauning, with a weak liquor of vje 
 and oatmeal. The peculiar odour is due to saturation with birch-oil. The 
 usual dye is Brazil wood. The markings on the leather are produced by 
 rollers. 
 
 Calf Kid. — This leather is ' tawed ' hke glove kid, and not tanned like 
 ordinary leather. 
 
 Glove kid is chiefly made from lamb and kid skin, skin of very young 
 animals being used for the finest kid. 
 
 PrejMratioii of Hides for Tanning. — The hides are received some fresh, 
 and some salted, all more or less filthy. Both kinds are first well soaked in 
 water, the salted ones for a longer time than the others. 
 
 The object is to thoroughly soften and cleanse the hide without it being 
 allowing it to putrefy. To assist this process, brine is sometimes used ; or 
 borax, sulphide of sodium, &c., is added to the wash. Sometimes putrid 
 liquors are used, especially for skins known as Indian ' kips.' 
 
 Unliairing the Hide. — This is almost universally done in England by the 
 aid of lime. The lime- wash is of no very definite strength, but there is- 
 always a considerable quantity of lime in suspension. The hme-water dis- 
 solves the substance which unites the fibres of the skin together, and it also 
 removes the albumen present in the hide (in the blood-vessels, connective 
 tissue, &c.) The epidermal layer of the skin softens and swells in the lime 
 bath, and the hairs are so loosened that scraping with a blunt knife causes 
 the whole rete Malpighi and hair follicles to come away. At the same 
 time the skin becomes swollen and plump, which renders the 'fleshing' 
 (i.e. the removal of adherent particles of flesh) easier ; the fat of the hide is 
 also converted by the lime into an insoluble soap, and the removal of the 
 hair is made easier. 
 
 The hming is usually done by simply plunging the skins into large pits 
 of hme and water, out of which they are drawn (' hauled ') once or twice 
 daily, while the undissolved lime is stirred up. There is used roughly 
 from one to four poimds of hme per hide in the pit. Instead of being simply 
 left lying in the pit, the hides are sometimes placed on frames, which can 
 be raised and lowered at wall in the water. An addition of orpiment is 
 very commonly made to the lime to facilitate depilation. In America and 
 on the Continent the unliairing is frequently done by ' sweating,' which may 
 be 'warm' or ' cold,' both processes being essentially dependent on partial 
 putrefaction. The former was a crude method, and consisted of piling the 
 hides and inducing slight putrefaction and heat, the hides if necessary being 
 covered wdth fermenting tan. 
 
 The ' cold sweating,' or American method, consists of hanging the hides 
 in moist ' sweating pits ' at a uniform temperature of about 60°-70° F. 
 
 When the hair has been thoroughly loosened by one of these methods 
 it is scraped off by a large two-handled knife, and scraps of fat and flesh are 
 removed from the inner side by scraping, brushing, or paring, the hide 
 being well worked, to press out, as far as possible, any fat in the tissues. 
 
 After being unhaired and fleshed, the hides are commonly cut up into 
 'bests,' or the best and thickest parts, and the 'offal,' or lighter parts. 
 These have next to be thoroughly freed from any adherent lime before being 
 tanned. This is done by placing them in water for from twelve to twenty- 
 four hours. 
 
 Tanning consists in treating the liides, after liming and washing, with 
 bark or some substance containing tannin. The chief substances used are 
 oak-bark, one of the oldest and most popular substances, divi-divi (a South 
 American bean, Gisalpinacoriaria), chestnut extract (prepared from rasped' 
 
OFFENSIVE BUSINESSES 917 
 
 ■wood of the Spanish chestnut), hemlock extract (from bark of American hem- 
 lock pine), valonia (the acorn cup of an evergreen oak grown in Greece and 
 the Levant), mimosa bark (from several kinds of Australian acacias), myra- 
 bolans or myrobalans (the fruit of an Indian shrub), catechu, kino, 
 sumach, &o. 
 
 The ground tan is placed in pits made of flag-stone, cement, crick, &c., 
 the pits being arranged in series according to the strength of the liquor, the 
 skins being placed first in the weakest one and afterwards successively 
 passed through each of the whole series. 
 
 The leather, after removal from the tan-pit, is hung on drying poles in 
 drying lofts till half-dry, and is then placed in piles on the floor till it 
 * sweats ' or ' heats ' a little. It is subsequently scraped, oiled, and rolled to 
 improve the texture and surface, and is often coloured. For some purposes 
 hides are ' shaved ' or cut down in thickness, or split. 
 
 Currying has for its object the preparation of soft, flexible leather, such, 
 ■e.g., as is used for the uppers of boots, for flexible belting for machinery, &c. 
 When the skins have been removed from the tan-pits they are dried, then 
 scraped and levelled ; subsequently they undergo further steeping, heating, 
 and stretching, and are again dried. After this they are oiled. Various kinds 
 of oil are used for oiling in the grain — whale, cod-liver, castor, linseed, &c. — 
 while for oiling on the flesh a mixture of tallow and cUgras is considered the 
 best. [Degras is the surplus oil which is got by exudation and pressing from 
 the oiled chamois leather while in process of manufacture.] 
 
 From this sketch of the manufacture of leather it will be seen that it calls 
 for the supervision of the Sanitary Authority, and may readily prove a source 
 of serious nuisance in thickly populated districts. And yet leather-making 
 may with proper care be carried on, and is so in many populous places, with- 
 out complaint or apparent harm to the inhabitants. 
 
 But tanneries might with advantage be relegated to suburban and open 
 ■districts J although if situated far from the sewers of the town nuisances may 
 arise from the disposal of the various liquors, which are often offensive. 
 Among the sanitary precautions called for is in the first place the prevention 
 of the pollution of rivers by the discharge of wash-water or spent liquor. 
 Precipitation by lime and clarification should be insisted on in all cases before 
 such waters are allowed to run off. Where the pits are within dangerous 
 proximity to a stream, it is advisable to have an escape tank, the bottom of 
 which is well below the level of the river, in which the liquors can be treated. 
 Ultimately even filtration through sand or treatment with a deodorant may 
 be called for. 
 
 Nuisance may arise also from solid waste, hair, bits of flesh, fat, skin, 
 &c., as well as from the d6bris from the bottom of the lime and tan-pits. 
 The former are useful for glue-making and manure, while horns are used for 
 comb and knife-handle making. The spent tan is also good for manure, and 
 the liquor may with advantage in many cases be used for irrigating land. 
 
 The possibihty of the presence of arsenic, especially in the case of the 
 skins of rarer animals, which are often roughly treated with it immediately 
 after removal fr'om the animal in order to preserve them during carriage, 
 jnust be borne in mind. 
 
 Nuisance is especially Hable to arise from bits of flesh, &c., being allowed 
 to accumulate and putrefy on the premises until a sufficient quantity has 
 been collected to make a load for removal ; such debris should be fr-equently 
 removed and should be kept in suitable air-tight receptacles. This source of 
 nuisance, it will be noted, is not essential to the trade, but arises fr-om culpable 
 neglect. 
 
918 HYGIENE 
 
 When gas lime is used instead of fresh lime, serious danger may arise- 
 fi.'om gases evolved through the action of acid liquors ; sulphuretted hydrogen 
 and carbon dioxide may be given ofi' in fatal quantities. 
 
 The dyeing of leather has sanitary importance from the fact that in some 
 cases dangerous metals are used for the purpose. For instance, an alkaline- 
 solution of oxide of lead is used in the preparation of astrachan, which dyes 
 the hail' black, but leaves the skin white. Such skins often contain much 
 lead dust, which is frequently left in the hair purposely as a protection 
 against moths. Again, the skins of foxes, otters, badgers, and rabbits, are 
 often treated with a mixture containing protosulphate of iron, orpiment, 
 oxide of lead; common salt, acetate of copper, and other ingredients of a, 
 highly poisonous character. 
 
 Wash-water from skins which have been treated with orpiment and lime 
 readily gives off sulphuretted hydrogen, which leads to the production of 
 sulphide of arsenic, and by oxidation to formation of arsenious and sulphurous 
 acids. Free arsenious acid may also be discharged from the orpiment and 
 form combinations with some of the calcium, which, however, are soon re- 
 dissolved by the ammonia present whenever there is putrefaction. The 
 danger arising from the presence of such poisons is best obviated by treat- 
 ment with salts of iron, which form insoluble arseniates. 
 
 With regard to the etl'ects of leather-making on the workmen employed, 
 there does not seem to be any special danger or trouble to which they are 
 hable. Some suffer from local excoriation and sores in the hands, and 
 especially the fingers ; which is no doubt mainly due to the action of the 
 lime, though in some cases the arsenic (orpiment) used is more particularly 
 blamed. Sometimes this ailment takes a rather characteristic form, occurring 
 as small perforating holes in the pulp of the fingers from which blood oozes, 
 and which are sometimes difficult to heal. 
 
 As to the use of gloves by the workmen for protection against the action 
 of the lime, the men themselves say that the danger from Hme getting inside 
 the gloves and acting on the hands, without chance of being rubbed off, is 
 much greater than when their hands are quite unprotected. There are no doubt 
 some grounds for this objection; still there seems no reason why gloves to 
 reach well up the arm should not be used. Workmen are ever ready to find 
 reasons against any change in their modus operandi. 
 
 The construction of the premises where this business is carried on often 
 leaves much to be desired. The more carefully they are adapted to the work, 
 the less likelihood is there of a nuisance arising. It is very important that 
 the pits should be all perfectly water-tight, that the surface of the floors 
 around should be smooth, Avater-tight, properly sloped, and provided with 
 Well-laid gutters. The more open the whole of the premises are to the 
 Hght and air the better. The walls should be of hard smooth material, 
 especially the lower five to six feet, where they are liable to be splashed, so 
 that they may not absorb dirt, and that they may be washed as often as 
 necessary. Water for this purpose, with hose, should be at hand, as well as 
 conveniences for the workpeople to wash themselves. 
 
 The writer once succeeded in terminating much acrimonious feehng 
 and legal proceedings between certain persons, neighbours of leather works 
 and the proprietors, by a simple and inexpensive plan. The works were 
 situated in the worst possible place— the cellars and the ground floor of a large 
 building in a very thickly populated district of a town. The building was in 
 the centre of a long row of warehouses, all of which were occupied ; and com- 
 plaints of the nuisance from the tannery had been long, continuous, and. 
 well-founded. The preventive measures adopted were (1) reflooring of the 
 
OFFENSIVE BUSINESSES 919* 
 
 tannery with best concrete, properly sloped and guttered, and concreting of the 
 lower five feet of the walls ; (2) removal of all wood-work from the pits ; stone, 
 brick, or concrete to be used instead ; (3) provision of air-tight iron boxes for 
 scraps, and their frequent removal ; (4) proper supply of water and hose ; 
 (5) provision of proper aeration of the premises by artificial means ; (6j the 
 provision of a sheet-iron flue, with large trumpet-end leading from the cellars 
 and opening above the roof, provided with a powerful sun-gas-burner to ensure 
 a good draught. At first there were complaints arising from the escape of 
 effluvium from the top of the flue, which, contrary to the agreement, had 
 been made to terminate at the roof. The addition of ten feet to the height 
 of the flue had the satisfactory result that no further complaints were made. 
 The workmen were as pleased with the result as the neighbours. 
 
 PIG- KEEPING 
 
 Although the Public Health Act, 1875, Sec. 47, states that pigs must not 
 be kept in towns so as to be a nuisance, and the Public Health (London) Act, 
 1891, Sec. 17, prohibits in the metropolis pigs being kept so as to be a 
 nuisance, or within forty feet of a street, still pigs are kept in towns, and even 
 within the metropolitan area, so as to be abominable nuisances. Even in 
 the country districts much greater care ought to be exercised in the keeping- 
 of pigs, as to site and drainage of the styes, the cleanliness of the animals,, 
 drainage, &c. 
 
 Pig-keeping becomes a nuisance (1) on account of the sour, stinking food 
 on which they are too commonly fed, and (2) in consequence of the atrocious 
 smell of their excreta, greatly increased by being left unremoved for long 
 periods. 
 
 Pigs are very frequently fed on sour refuse vegetable matter, blood, offal, 
 and other abominations, not, perhaps, as is vulgarly stated, because th& 
 animal thrives best and is healthiest when so fed, but because it is thus 
 rendered a useful scavenger ; and in one sense the pig does become a valuable 
 member of the community by turning into useful food nutritious substances 
 that would otherwise be wasted. There is no doubt, however, that the 
 feeding of pigs with garbage tends to the spread of parasitic, and possibly 
 other diseases, and it is hardly credible that the flesh of animals fed on filtL 
 is of the same quahty as that of animals fed on wholesome food. 
 
 Pig-styes should be situated at a considerable distance from dwelling- 
 houses ; they should be floored with asphalte, concrete, or other hard and 
 impervious material. Jointless floors are best. There should be a proper 
 slope of the floor towards a channel leading to a grating, having bars not 
 more than three-eighths of an inch apart, and communicating with the drain 
 by a trapped inlet. The wash and other materials evolving effluvium should 
 be kept in impervious air-tight vessels. The animals should be regularly 
 washed and kept clean. Attention to these matters will reduce the nuisance 
 to a minimum ; and it should not be forgotten that the pig is naturally a cleaa 
 animal, always depositing its excreta in a special portion of the stye, and 
 keeping the remainder clean, if there is sufficient room. 
 
 AETIFICIAL MANUEES > 
 
 This subject is one of the first importance, from the magnitude of the 
 trade and the sanitary questions involved. The trade utiHses an enormous 
 
 ' The reader desirous of learning full details on this important subject, so difficult 
 to become acquainted with, is referred to Dr. Ballard's encyclopaedic article, to which, 
 the writer is largely indebted. 
 
920 HYGIENE 
 
 amount of material which would otherwise be absolutely useless, and would 
 be most difficult to get rid of at all ; and at the same time produces a most 
 valuable result, some small compensation for the reckless waste of the nutri- 
 tion of the land which is carried on in the waste of the sewage and excrement 
 of the population. These manures are designated as ' bone manure,' ' blood 
 manure,' ' poudrette,' ' superphosphate,' &c. 
 
 The materials used are of various kinds and include : — 
 
 (1) What may be grouped as nitrogenous materials : the dSbris of 
 knackers' yards, rotten flesh, fish, blood, intestines ; offal from tanneries, 
 tripe and trotter boilers', glue works, scraps of skin, hair, ' scutch,' shoddy, 
 night-soil, &c. 
 
 (2) Phosphatic materials : bones, boiled, unboiled and calcined, animal 
 charcoal and materials retained in it when used as a filter — e.g. sugar-scums, 
 fossil bones, coprolites, mineral phosphates from South Carolina, Germany, 
 and Spain, and apatite, bone black, bone ash, &c, 
 
 (3) Saline materials — e.g. sulphate of ammonia, common salt, and nitrate 
 of soda. 
 
 (4) Deodorants and dryers — e.g. soot, gj^psum, ashes from coal and burnt 
 tar, &c. 
 
 During the process of manufacture, sulphuric acid or hydrochloric acid is 
 used. The former acid is commonly used as ' chamber acid ' (that is, acid 
 taken and used direct from the leaden chamber where it is made), and as such 
 almost invariably contains arsenic as a chief impurity. From two to three 
 pounds of arsenious acid per ton of chamber acid is no uncommon quantity. 
 
 ' Superphosphate ' proper is prepared from a mixture of mineral phosphate 
 and ground bones, treated with sulphuric acid. The minerals are crushed, 
 ground, and sifted so as to reduce them to a fine powder, and are then 
 mixed with sulphuric acid. The crushed bones are added subsequently. 
 The mixing is done in small works by hand, but in large works, where 
 extensive buildings and machinery are often devoted to this manufacture, it 
 is invariably done by machinery. The mechanical mixer consists of a re- 
 ceiving box for the materials, and an axis or paddle with projections which 
 revolves and stirs up the manure as it is supplied. The acid, usually 
 ' chamber ' acid, is run in from a cistern, and is stirred up with the dry material 
 until a thick paste-like mass is produced, the consistence of which depends 
 on the proportion of sulphate of calcium formed. This process only 
 lasts ten to fifteen minutes, and is accompanied by strong chemical 
 action, and the evolution of great heat and a considerable quantity of 
 vapour. When bones alone, without mineral phosphates, are used, 
 the heat developed has been known to reach as high as 240° F. The 
 vapour, besides water, contains among other injurious substances fluorine 
 (tetrafluoride of silicon), arsenic (chloride and arseniuretted hydrogen), 
 and small quantities of antimony. The heat is useful in drying the 
 manure, and thus facilitating its reduction to powder. In large works 
 the manure is usually allowed to pass direct from the mixer into a special 
 chamber, called the ' hot den,' where it remains for a period of one to four 
 days, according to the demand. If it is too thin, some gypsum is generally 
 added as a drier. 
 
 After being deHvered into the ' hot den ' the manure continues to 
 give off offensive fumes, until its temperature has fallen. Hence this den 
 must be made air-tight, and the openings into it be capable of being 
 accurately closed when it is in use. By being allowed to cool in the 
 den, moreover, a good deal of the vapour is retained, which is spread 
 around if the manure be manipulated in the open while still hot and damp. 
 
OFFENSIVE BUSINESSES 921 
 
 But even after two to three days' retention in the ' den ' the temperature of 
 the manure is still high, and when being dug out it may give off large 
 quantities of offensive vapour. Ultimately the manure is pulverised, in large 
 works, by machinery, and filled into gunny bags, in which it is sold. 
 
 The whole process of manufacture of ' superphosphate ' is more or less 
 offensive to the sense of smell. The presence of the organic materials from 
 which the manure is to be made, of finished and fuming manure, and the 
 very premises themselves, which are permanently employed for the production 
 of the manure and continuously exposed to the action of these vapours, all 
 make the special smell an all-pervading influence. Still, in well-managed 
 works it would not be justifiable, as a rule, to say that the effluvium is a 
 serious nuisance to the average man, and in the ordinary sense. 
 
 The nuisance is often complained of even before the materials reach the 
 works, owing to the stench caused during their conveyance there. This 
 can be obviated partly by their being brought as far as possible in a fresh 
 state, and without waiting for their accumulation to form a large consignment 
 (which means also increased time given for putrefaction), and more completely 
 by their being brought in proper air-tight receptacles. The night-soil ' pails ' 
 in various towns are sufficiently well fitted to allow of their being conveyed 
 full and in large numbers through the streets without any nuisance being 
 caused. When received at the works the materials should be properly stored. 
 Gypsum thrown on the bones acts as a good deodorant, and charcoal, ashes, 
 and dry earth are also beneficial. There should be proper cesspools or other 
 receptacles for the reception of the night-soil. 
 
 The highly irritant vapours which arise in the mixing and are discharged 
 from the ' hot den ' may be dealt with on the same principles as already 
 referred to in treating of effluvia from other sources, i.e. by fire, water, or air : 
 combustion, solution, condensation, and dilution. The vapours may be con- 
 ducted by a flue and fan into the furnace, or if necessary the whole den 
 should be within a well-built shed, and the vapours between the two might 
 be dealt with in this way. Condensation can be very efficiently effected by 
 means of a long flue in which the vapours, hydrofluosilicic acid, arsenic, offen- 
 sive organic gaseous compounds, &c., may be condensed, and never reach the 
 chimney at all, so as to be discharged into the air. In some large works 
 no less than 440 feet of condensing passages have to be traversed before 
 the chimney is reached. The length and efficacy of this can be greatly 
 increased by the insertion of faults to compel the vapours to traverse a 
 tortuous course. The vapours may also be treated more cheaply, but not 
 more effectually, by the cold-water shower-bath (' scrubbers '), all non- 
 absorbed gases being drawn into the boiler fire. 
 
 ' Poudrette ' is the name given to a manure in the form of a dry powder, 
 of a brownish colour, prepared from night-soil treated with sulphuric acid. 
 Sometimes other ingredients are added, or may even predominate, for the 
 term is not applied to a specific compound, but its commonest signification 
 is that stated above. The processes used vary considerably. In the form 
 employed at the Corporation Works of Manchester, Eochdale, Warrington, 
 and other * pail ' towns, the contents of the pails are thrown into a steam- 
 jacketed boiler provided with a revolving stirrer to prevent incrustation, and 
 holding some 400 gallons, in which they are desiccated in from four to sis 
 hours. The desiccated excrement ('poudrette') is discharged by an opening 
 in the bottom of the boiler. The steam in the jacket is under a pressure 
 of about four atmospheres. About thirteen pounds of sulphmic acid are 
 added to every hundredweight of excrement for the purpose of fixing the 
 ammonia. Fish-offal (heads, guts, &c.) ground in a mortar mill and other 
 
922 HYGIENE 
 
 waste are sometimes added, and thus a useful way is found of getting rid of 
 a troublesome and offensive material. About 92 to 93 per cent, of the weight 
 of material is lost dm-ing the desiccation. 
 
 The vapours from the boiler are drawn off, and in some cases are condensed 
 in a cold shower-bath — in one case in a pipe run along the bottom of a stream 
 — and it is certainly possible to conduct the whole process without the least 
 nuisance either inside or outside the works. 
 
 In another process, the acid is added to the excrement in the pails, which 
 is then thrown into a Milburn's desiccator (patent July 30, 1872, No. 22GG),. 
 from which after being partially dried it is removed to a hot drying-floor, and 
 is subsequently broken up and packed for sale. 
 
 According to another process, to a charge of some 550 gallons of excrement 
 eiglity pounds of magnesian limestone are added and the whole is distilled. 
 The ammonia is conducted into a saturator containmg brown sulphuric acid, 
 and is there fixed. The offensive vapours, after serving to partly raise the 
 temperature of the excrement before it is thrown into the boiler, are con- 
 densed and run into the drains. The sulphate of ammonium recovered is a 
 valuable item, and it serves to reduce the working expenses. 
 
 The importance, in obviating the nuisance on such works, of a high 
 chimney with powerful draught, and of a long flue, to the efficiency of which 
 a good fire will greatly contribute, cannot be overestimated. It should 
 further be a general rule that the whole of the operations should be con- 
 ducted within a large, airy, closed building, except where some obvious 
 impossibility exists to this being done ; and this will be very rare. 
 
 STOEAGE AND TEEATMENT OF VAEIOUS MATTEES WHICH MAY 
 BECOME A NUISANCE 
 
 In large towns it is very difficult to avoid the accumulation of various 
 materials which, harmless while fresh, may become most offensive, and a 
 source of danger to health, when stored for some time. 
 
 Sanitary authorities are usually very unwilling to give much assistance 
 in the removal of what is termed ' trade refuse,' and seem to imagine that a 
 fine stroke has been made when they refuse to assist dealers in the removal 
 of an accumulation of stinking fish-heads and guts, or of rotten ff'uit and vege- 
 tables from the same premises from which they are bound by law to remove 
 night-soil. The Sanitary Authority may be within their rights, but are 
 they benefiting the public by this action ? Private individuals have not the 
 means of getting rid of offensive matter of this kind, and they shirk the 
 difficulty by letting the nuisance increase ; further, it is more than question- 
 able whether they should be allowed at their free will to pitch it into the first 
 convenient corner, quarry hole, or ditch. It was for such reasons that the 
 law was made to encourage sanitary authorities to remove night-soil, because 
 they can do it better than private individuals, and have, or should have, 
 means of disposing of it, if not at a profit, at least so as to diminish the cost 
 of removal. The rapid disposal of such materials is for the pubHc benefit, and 
 no body of ratepayers would ever object to the Local Authority doing the work. 
 
 Manure 
 
 Among the offensive things stored about houses is manure, chiefly horse- 
 manure. For some inscrutable reason the dung of animals has come to be 
 regarded by the public as almost unobjectionable, while the sight of a few 
 ounces of human excrement will sometimes cause quite an uproar. 
 
OFFENSIVE BUSINESSES 92» 
 
 Horses must be kept in towns, but the accumulation of their dung is not 
 necessary, and is objectionable. When such manure is allowed to accumu- 
 late to a large quantity its removal is very offensive, and the stench often 
 most pungent and far-reaching, and is quite capable of passing through 
 ordinary brick walls, to say nothing of doors, windows, and chimneys. 
 
 Dung-heaps should not be tolerated in the populous parts of towns, and 
 more particularly in the very poor parts. Eemoval every two to three days 
 should be insisted on, and, like night-soil, it should be removed at night ; the 
 place where it lies in the yard should be sheltered from the rain, and should 
 not abut on the wall of any dwelling-house. 
 
 The custom of making grooms, stablemen, &c., sleep in rooms over the 
 stables is certainly objectionable — not entirely because the companionship 
 of a horse is injurious to a man, but mainly because stables are generally 
 situated in places not fit for men to live in, and especially so in large towns, 
 where land is very dear. In London the so-called ' mews ' are hotbeds of 
 disease, owing to the foul air and the generally uninhabitable condition of 
 the places from accumulation of manure and dirt. 
 
 Bones 
 
 Bones soon become offensive if kept. The grease attached to them becomes 
 decomposed, capric, caprylic acids, and butyric, and other products of putrefac- 
 tion being formed, and these give off very disgusting smells. They are often 
 stored in private houses until quite putrid, and then the ' rag-man ' usually 
 gets them, and conveys them perhaps to his own home, where they may lie 
 for months, before he finally disposes of them to the bone boiler or manure 
 maker. 
 
 The best mode of preventing this nuisance is the absolute prohibition of 
 keeping bones in quantity in any house ; rag-pickers should be obliged to 
 dispose of them at once, without storing them for any time in their homes. 
 In private houses they should be burned, like all garbage, or be kept as far from 
 the dwelling-house as possible and in some well-covered receptacle, but, no 
 matter how kept, it is difficult to keep down a stench, if kept any time. 
 
 The health may undoubtedly suffer from the effects of exposure to this 
 nuisance. 
 
 Fish 
 
 While the smell of fresh fish is pleasant, that of stale fish is horrible. 
 ' Fresh ' is a relative term, and really fresh fish — that is, fish not more than a 
 day or two after being caught — is unknown in most of our large towns. The 
 great bulk of the fish in England is not landed until it has been a week or 
 even longer out of the sea. The fishing-boats from Grimsby and other great 
 fishing ports go to sea and as a rule do not return for some seven to ten days. 
 The fish are usually kept in ice during this time, but are sometimes kept aUve 
 in tanks. The herring fleets are escorted by special boats, which convey these 
 delicate fish to land at shorter intervals. 
 
 Hence it is not surprising that the fish which the salesman declares has 
 * only arrived to-day ' may go bad the next day. 
 
 The smell of bad fish is most adhesive, and the nuisance is increased by 
 the detachment from the fish of the scales and slime, which stick to every- 
 thing and putrefy. Extreme cleanliness and the rapid removal of all garbage 
 is the essential condition of prevention of nuisance from fish. 
 
 The difficulty is increased by the large amount of d&bris, guts, skins, 
 heads, tails, &c., which are necessarily produced in the way of business. There 
 
924 HYGIENE 
 
 is seldom adequate provision made for the disposal of these things ; they are 
 allowed to accumulate and rot, and they spoil the good fish. The Sanitary 
 Authority should be ready and willing to assist in getting fish-dealers out of 
 their difliculties by removing all their refuse. 
 
 Fish refuse may be advantageously disposed of without nuisance by 
 grinding it in a mortar mill, mixed with Ume and soot or ashes, for manure. 
 Vegetable refuse may be also ground with it. 
 
 Like other filth, decaying fish may be injurious to health. 
 
 Feuit and Vegetables 
 
 Fruit and vegetables are liable, especially in summer and damp weather, 
 to decay, and then become ofl'ensive. The immediate removal and destructio]i 
 of decayed fruit is the only step to be taken, except the preliminary applica- 
 tion of deodorants. 
 
 Vegetables require to be stored in cool, well- ventilated cellars, where 
 they should be examined fi-om time to time and the decaying ones removed. 
 
 The health may be injuriously affected by the emanations from decaying 
 fruit and vegetables. 
 
 The condemned material may be utilised as manure, and for this purpose 
 should be conveyed to and kept at a suitable distance from the outskirts of the 
 town. A considerable quantity of it may also be more expeditiously utihsed 
 by grinding it in a mortar mill with fish debris (q.v.). Attempts have been 
 made to get rid of the great mass of vegetable waste that accumulates in 
 towns by calcining it in a special form of kiln, and the results have been 
 satisfactory, except from a pecuniary point of view. 
 
 Eggs 
 
 On the premises of large dealers in eggs, who dispose of vast numbers 
 weekly in the ordinary way of business, there is always a considerable number 
 of rotten eggs, which are very offensive. Careful keeping in a cool cellar, 
 with supervision, and the early removal of bad material, wdth the use of 
 chlorinated lime, are the means to be adopted to avoid further evils. 
 
 Eags 
 
 The rag-picker is the symbol of the lowest stage of civilised life, except 
 the pauper. His business is to fill his bag with refuse of every kind, rags, 
 bones, scraps of meat, old clothes, &c., which he does regardless of quaUty, 
 and to sell them. The bones he sells to the bone-boiler, the rags he collects 
 for sale to the paper-maker ; however, he rarely does this directly, but through 
 a middle man. The latter often carries on business in an extensive way, 
 exporting the material to distant countries : he stores and roughly sorts 
 immense quantities of rags in premises which commonly are as dilapidated 
 as the ' raw material ' of his trade. The rags, collected from the gutters, 
 ash-pits, and any other place where they are found, often give these stores 
 an abominable smell. It is surprising that infectious disease is not frequently 
 traceable to these places, as the quality of the rags is never questioned, and 
 they must often come from infected premises. Small-pox and woolsorters' 
 anthrax have been traced to infection from rags. 
 
 That all such places should be under the watchful care of the Sanitary 
 Authority is obvious. The stores and contents should certainly be disinfected 
 from time to time, and the use of lime-wash should be insisted on. Every 
 
OFFENSIVE BUSINESSES 925' 
 
 effort should also be made to prevent infected articles — bedding, old clothes, 
 &c. — being deposited in such places until they have been rendered harmless 
 by disinfection. 
 
 CAKPET-CLEANING 
 
 The knowledge that infectious virus is a tangible thing, emanating from 
 the infected person, and that it may be found deposited on carpets and other 
 articles of furniture, makes it obviously improper that carpets should con- 
 tinue in the old-fashioned way to be shaken and beaten in the streets and 
 yards, or sha,ken out of the windows. Apart from the danger of infection, 
 there is the nuisance from the dust. In most towns of any size there are 
 now carpet-cleaning establishments. These places are sometimes a source 
 of annoyance from the noise of the machinery, as well as from the dust, 
 which is in some places allowed to escape from windows but little elevated 
 above the street. This should never be permitted. The dust should either 
 be drawn by a fan, &c., into a high chimney, whence it will be rapidly blown 
 about through the air, or, what is much better, be drawn under and into the 
 boiler-fire, where it will be destroyed. 
 
 HAIR- AND FLOCK-PICKING 
 
 Unfortunately it is not the general custom to have beds, pillows, feather 
 quilts, and such articles opened up and cleaned from time to time. Such 
 things are often used for generations in a family without ever being taken to 
 pieces, repicked and cleaned, and not infrequently are sold and bought and 
 treated in the same way. And yet a moment's consideration will convince that 
 they must become laden with dirt, if not with infectious matter. Observation 
 of the process of picking an old mattress would astonish most people by the 
 clouds of dust (= dry filth) with which it is laden. There is no doubt that 
 pathogenic organisms remain quiescent in such receptacles, and become active 
 and dangerous when favourable conditions arrive ; this has been proved by 
 experiment. 
 
 This work is usually done by hand in the houses of poor persons. It is 
 greatly to be desired that it should become a regular practice to have all such 
 articles cleaned from time to time, and that suitable establishments, where 
 the work would be done by machinery, should be erected in aU towns. 
 
 STEEET SWEEPING 
 
 The maintenance of the streets in a clean state, free from dirt and dust, 
 is one of the most important pubHc sanitary arrangements, second only to 
 drainage and sewerage, although it is very unusually looked on as of such 
 value. That the surface of the streets should be hard, smooth, and imper- 
 vious is of the utmost importance, not only for the convenience of traffic, but 
 for the prevention of the accumulation of filth, which too often is the parent 
 of disease, as well as of discomfort. 
 
 It must be remembered that the area of the streets is considerable ; that 
 they are continually befouled with excrement of healthy and diseased 
 animals, and not infrequently of hmnan beings, and receive offal of every 
 kind from the houses ; in the poorer parts people commonly throw their 
 slops, sweepings, and every kind of rubbish into the street. The streets are 
 subject to those changes of dryness and moisture which are most favourable 
 to putrefaction ; they are continuously traversed by the people, and are 
 
«26 HYGIENE 
 
 the playgrounds for the cliildren of the poor, and often are the only place 
 where the adult poor can rest in the open ah' after work is over. All day 
 long the door of the poor man's dwelling-room opens direct on to the street 
 (usuaUy this room is too dark and close to be habitable if the door were 
 kept shut), and all day his family live almost in direct contact with the 
 street and its emanations. 
 
 Ordinary mud is practically not very different from sewage, yet we com- 
 monly tolerate during many months of the year acres of streets covered with 
 mud, more or less solid, evaporating its moisture and sending its stenches 
 into our lungs and houses. When dry weather ensues the dry mud is con- 
 verted into dust, and penetrates bodily into our mouths (to be swallowed) 
 and noses (on its way to the lungs) and spreads itself over every part of our 
 houses, where it deposits itself on our food, furniture, walls, &c. 
 
 The direct connection of disease with the existence of acres of evapo- 
 rating slush in our streets, or with clouds of dust, has never been esta- 
 blished. But a moment's thought will convince that it is more difficult to 
 conceive these conditions as being harmless, than to realise that they can 
 continue with impunity. 
 
 Hence the importance of the work of the street-sweeper. His work, 
 being usually regarded as of very secondary importance, and as being mainly 
 required to prevent mechanical obstruction from mud, or to check the com- 
 plaints of the public as to dust, is seldom properly done. The usual way of 
 remo\Tng dust is to try to sweep it into small heaps while perfectly dry, and 
 possibly while a brisk wind is blowing, and to put into an open cart so much 
 of the heap as the wind does not blow away, and to remove as much of 
 the cartload as the wind leaves in it to the tip, or depot for mud and 
 manure, if one exist in the town. This is the ordinary mode of procedure, 
 and it is calculated to aggravate rather than lessen the evil. It encourages 
 the blowing about of the dust, and the sweeper is only an unnecessary ex- 
 pense. The dust should always be damped before the sweeping is done. 
 
 But the difficulty with the dust would be greatly lessened if the mud, 
 which is so easy to remove, were not allowed to accumulate to form dust. 
 The removal of mud is a mere mechanical labour, much easier than the 
 removal of the dust. 
 
 During ram the sweeper should be at work assisting the rain to clean the 
 streets. But the mud should be carted away at once, and not left lying in 
 heaps on the roadside until it has been spread over the surface again by the 
 traffic, as is very commonly the case, or until it has been converted into dust 
 during the next dry weather. The mechanical sweepers drawn along by a 
 horse are excellent for this work. 
 
 The suggestion to use for allaying the dust a solution of chloride of 
 calcium, a very deliquescent salt, which retains much moisture, might in 
 exceptional circumstances be useful. 
 
 But it should never be permitted to dissolve ice and snow on the streets 
 by admixture of salt, because it forms an intensely cold ' freezing mixture,' 
 injurious to boots and cruel to the wearer. The reality of this may be 
 judged from the fact that such a mixture will give a reduction of tempera- 
 ture of from + 10° to - 18° C. (1° C.= 1-8° F.) 
 
 OIL-CLOTH (FLOOE-CLOTH), LINOLEUM 
 
 The term ' floor-cloth ' was originally applied to a cloth covered with 
 several layers of paint. But owmg to certain defects — its coldness, shpperi- 
 
OFFENSIVE BUSINESSES 927 
 
 3iess and hardness — this substance is being superseded by kamptuhcon, 
 hnoleum, and other substitutes, free from these defects, and quite as 
 cleanly. 
 
 ' Oil-cloth ' is made of coarse canvas, usually manufactured from jute. 
 It is suspended on a frame, which can be extended by screws so as to stretch 
 the canvas, and on this it is coated first with size (to smooth the surface and 
 also prevent the corroding action of the oxidisation of the linseed oil subse- 
 quently applied) ; afterwards a coating of very thick paint (commonly yellow 
 >ochre or red oxide of iron) is laid on with a trowel, and well worked in. 
 Both sides are treated in this way, and when this layer is dry additional 
 ones are similarly applied ; last of all the pattern is printed on after the oil- 
 cloth has been taken down from the frame. Blood and lime are sometimes 
 used instead of size. 
 
 The drying is a tedious process, which used to take ten to twelve months, 
 but it is now effected in rooms artificially huated to about 180'^ F, in one- 
 fourth of that time. During the drying by heat very offensive vapours are 
 given off. 
 
 Linoleum consists mostly of cork, finely powdered by machinery, linseed 
 oil oxidised by exposure in a thin film to the air, and mixed into a sort of 
 cement with rosin and Kauri gum. These ingredients are heated together 
 in a steam -jacketed pot, provided with stirrers and an air-tight lid, a pipe 
 from which conducts the vapours into the furnace. After a couple of hours 
 the fusion is complete, and the ' cement ' is discharged into a cold rolling- 
 mill beneath, the roller being hollow, and kept cool in summer by cold 
 water inside. The fumes given off at this stage are very pungent and 
 offensive. After being rolled, the cement is ready for use, about 46 lb. being 
 mixed with 56 lb. of the ground cork. They are mixed in a mill, with steam- 
 heated rollers, the colouring matter being added, yellow ochre and barytes 
 for brown, oxide of iron and vegetable black for red. Subsequently, after 
 ■undergoing further processes of mixing, the compound is rolled out in sheets, 
 and ultimately applied to the canvas made of jute, one surface only being 
 covered, the other surface bemg protected by a layer of ' backing,' consisting 
 of size and pigment, or of varnish. If necessary the surface is afterwards 
 printed. 
 
 There is considerable danger of explosion at two stages of this manufacture : 
 (1) during the pulverising of the cork, (2) when the ' cement ' and cork are 
 being mixed. The fine dust floating in the air is liable to ignite, and the 
 cement may take fire spontaneously. 
 
 The character of the nuisance from both these manufactures is similar, 
 almost identical, and arises from the vapour given off by the hot oil. In 
 the hot drying-rooms for ' oil-cloth ' it is hardly possible to breathe after the 
 cloths have been drying for some hours. The vapours cause a great nuisance 
 even at a considerable distance from the works. The only satisfactory way 
 of treating them is to propel them by. a fan into the furnace and burn them, 
 the process being greatly assisted by preliminary passing through water. 
 
 MANUFACTURE OF VAENISH 
 
 A varnish is a substance which apphed to the surface of an object 
 increases its lustre, preserves it from damp and weather, provides a hard 
 smooth coating, and improves the appearance. 
 
 There are various kinds of varnish : e.g. ' drying oils,' which become 
 hard and resinous by oxidation in the air ; oil varnishes, consisting of a resin 
 and drying oil ; compounds of gums, resins, &c., in a volatile liquid, which 
 
928 IIYGIEXE 
 
 by evaporation leave the precipitated solids as a glassy coating. ' Driers ' 
 are substances which accelerate the drying of oils, by themselves giving up 
 oxygen, or by acting as carriers of atmospheric oxygen ; oxide of manganese 
 and oxide of lead are among the substances commonly used for this purpose. 
 
 The principal resins used to make varnish are true copals, animi, dam- 
 mar, kauri, &c. 
 
 The following is the usual process of manufacture. The resin is melted 
 in a deep, narrow pot either by a coal fire or gas, and when fusion is complete 
 the action of the heat is discontinued (either by removing the fire or the pot), 
 and the oil (linseed oil commonly), which has simultaneously been heated 
 to about G00° F., is poured on the melted resin and stirred. The liquid is now 
 boiled in a shallow open pot, it being desirable at this stage to expose it freely 
 to the air, contrary to what is needed during the melting of the resin. If 
 necessary the mixture is thinned Avith turpentine when cool. Sometimes 
 the resin after being melted is cooled and subsequently dissolved in the oil by 
 heat, or the raw resin is fused in the oil. 
 
 The vapours given off during the manufacture are generally very offen- 
 sive and far-reaching, and are complained of as causing headache, malaise, 
 &c., by those exposed to them even at some distance. 
 
 The annoyance is due partly to the vapour from the boiling oil (acro- 
 lein), partly to those from the melting resins. The most effective preven- 
 tive is the condensation, either through a ' continuous condenser ' (similar 
 to that used for condensing the impurities in coal-gas) or in water ; or 
 combustion in a fire may be resorted to ; this, however, is an extravagant 
 method, as the condensed vapours yield products useful in the manufacture 
 of Brunswick black. 
 
 THE BOILING OP OIL 
 
 All oils have not the same properties as ' drying oils ; ' some, on exposure 
 to air, absorb oxygen, lose their greasiness, and become dry and hard more 
 readily and completely than others ; and it is the possession of these qualities 
 which constitutes a ' drying oil.' This valuable property of oxidising and 
 drying is increased by ( 1) exposure to the air m a thin film ; (2 i heating, or as 
 it is improperly termed, ' boiling ; ' (3) the addition of ' driers ' (substances 
 which accelerate the desiccation by parting with some of their own oxygen, 
 or acting as carriers of atmospheric oxygen), the chief of which are sulphate 
 of zinc, peroxide of iron (umber), and protoxide of lead (litharge). The first 
 acts by assisting the separation of the vegetable albumen and substances 
 which hinder the drying, while the other two are oxidisers. 
 
 Linseed oil, being one of the most important commercial * drying oils,' is 
 the one specially referred to in the following observations. 
 
 In the ordinary process it is boiled in an open iron vessel, heated by a 
 fire, sometimes in the open, sometimes under cover. Such pungent vapours 
 are given off that the workmen are seriously incommoded if they are freely 
 exposed to them. At a certain stage it is advantageous to subject the oil to 
 a draught of air, as it hastens the result. A still more effectual method is 
 to blow air through the mass of the hot oil. The open fire may with great 
 advantage be replaced by steam applied by means of a jacketed pan. 
 
 The vapours given off are very pungent and irritating, affecting the eyes 
 and causing nausea, headache, malaise, and vomiting, even at a considerable 
 distance from the works. 
 
 The most effective method of preventing nuisance is to have the pot 
 covered with a hood, from which a pipe, provided with a fan, drives the 
 
OFFENSIVE BUSINESSES 929 
 
 vapour into a fire, either that of the boiler, or the one under the oil-pot itself. 
 The nuisance is so great that, if necessary, a special hot coke fire, connected 
 with a high chimney, should be provided to destroy the vapour. It is usual 
 to ignite oil which is intended for making printer's ink, whereby the nuisance 
 of smoke is superadded to irritating stench. This, too, should be done under 
 a proper hood connected with a ventilating pipe leading to the chimney. 
 
 PAPER-MAKING 
 
 Paper is composed chiefly of cellulose, more or less purified. From the 
 thirteenth century, when rags were first used for paper-making, up till 1856, 
 when esparto grass was introduced, cotton and linen rags were almost exclu- 
 sively used for paper-making. Hemp, old ropes, straw, wood made into 
 pulp, canes, bamboo, waste paper, and many other substances are now used 
 for the same purpose. 
 
 The collecting and storing of rags, considering the character of the places 
 they come from — infected houses, filthy hovels, &c. — even if mainly done for 
 the purpose of paper-making, requires mention here as an important sani- 
 tary question. Care must be taken to keep them dry, as they may heat and 
 ignite spontaneously through slow combustion. 
 
 The preparation of rags for paper begins with dusting them in a 
 ' thrasher,' a machine in principle similar to the ' willowing machine.' After 
 this they are sorted and cut, usually by hand, into pieces about two to five 
 inches square, and they are again dusted in an agitator, after which they are 
 boiled, usually with carbonate of soda or caustic soda, or a mixture of both. 
 
 Next they are bleached, either by chlorine, which is passed into a closed 
 brick chamber, in which the rags are placed, or by the alternate application of 
 bleaching liquid and acid. 
 
 The subsequent treatment does not differ essentially from that of esparto 
 grass, the preliminary treatment of which will next be described. After a 
 preliminary picking out of impurities, the grass is boiled with caustic alkali 
 in a boiler with a perforated false bottom, steam entering beneath the false 
 bottom and forcing or ' vomiting ' the water up a wide tube, so that it is 
 kept in constant circulation. This boiler is necessarily kept closed fast by 
 screwing down the door. 
 
 After a time the liquor, which is very foul and contains resin, siHca, &e., 
 extracted from the grass, is runoff into a store well, and fresh water is poured 
 on and the boiling is repeated, after which the grass is reduced to pulp by 
 machinery. The manufacture of paper from the pulp does not require men- 
 tion here. 
 
 The recovery of the soda from the wash liquor is an important economical 
 operation, and is one of the most offensive parts of the whole manufacture. 
 The process employed consists practically in the evaporation of the liquid, 
 and subsequent incineration of the residue, during which carbonic acid is 
 formed from the vegetable matter, and combines with the soda to form car- 
 bonate of sodium. This when treated with lime forms caustic soda. 
 
 The vapours given off during the boiling of the grass, and from the hot 
 liquor and grass after removal from the boilers, cause an unpleasant odour 
 which has been compared to senna, and sometimes complained of as a 
 nuisance by neighbours. This can be entirely prevented by condensation in 
 cold water, the hot liquor being run in a coil of pipe through the water. Cold 
 water applied at once to the grass, after it is boiled, will entirely prevent the 
 unnecessary annoyance from vapours given off from it while cooling. The 
 
 VOL. I. 3 o 
 
930 HYGIENE 
 
 hot liquor should be run into a cooling tank, there to remain well covered in 
 until quite cold. 
 
 But the recovery of the soda leads to a greater nuisance, partly from the 
 vapour given oft' during evaporation, still more from the pungent empy- 
 reuniatic fumes produced by the ignition of the mass. The vapour should 
 be conducted by a flue into a tall chimney. The fumes produced during in- 
 cineration should be conducted under and into the fire. 
 
 Paper is coloured with a great variety of substances, of which the principal 
 are : For blue, cobalt blue, ultramarine, Derhn blue, indigo-carmine, &c. ; for 
 yellow, chrome yellow, or acetate of lead and bichromate of potassium, yellow 
 ochre, yellow ultramarine, &c. ; for green, Schweinfurt, or Vienna green, 
 Berlin blue with chrome yellow, &c. ; for brown, umber, &c. ; for red, madder 
 lake dissolved in ammonia, red ochre, &c. The aniline colours are also used 
 as paper dyes. For some few purposes the pulp is mechanically mixed with 
 the colouring matter. The use of poisonous colouring matters should be 
 absolutely forbidden, as being dangerous and unnecessary. As fine a green 
 can be oljtained now with harmless colours as with arsenic. 
 
 The use of paper coloured yellow with chromate of lead, red with minium 
 (red oxide of lead), or green with arsenite of copper has been specially forbidden 
 by some Continental Governments for wrapping roasted chicory, because, 
 this being a very hygroscopic substance, the poisonous colouring matters 
 of the paper may get dissolved by the moisture and lead to poisoning. The 
 same precaution should be taken with regard to papers used for wrapping 
 sweets, as children are liable to lick the papers. 
 
 INDIA-EUBBER MANUFACTURE 
 
 In this manufacture, and in the process of vulcanising, offensive odours 
 of sulphur compounds are liberated, intermingled with those of tar oils, 
 creosote, &c. These may be perceived at some distance from the factory, 
 and are persistent and disagreeable. The means to be adopted are to con- 
 duct the boiling operations in covered vessels, to use a ventilating fan, and to 
 pass the effluvia through a heated furnace. 
 
 ANTHRAX ' 
 
 This disease, which commits terrible havoc among the flocks and herds 
 in some countries, is comparatively rare in Eiigland. But there is some reason 
 to believe that it is much more prevalent among our stock than one would 
 suppose from the official returns made to the Agricultural Department of the 
 Privy Council, and more deaths of men and women are due to it than appear 
 in the published returns of deaths. 
 
 All the more important domesticated animals are susceptible to anthrax, 
 including the cow, sheep, and horse. It is rare among pigs, and old dogs 
 are little susceptible ; while puppies take the disease readily. 
 
 Workmen engaged in any capacity about infected animals, or the skins, 
 wool, oftal, &c., of such are liable to infection. Hence it is most frequently 
 observed among herdsmen, skinners, men who unload cargoes of hides, 
 slaughtermen, and also among those who manipulate various wools and hairs, 
 chiefly foreign, which have been directly derived from infected animals, or 
 have been packed with infected material for the purposes of transport. 
 Anthrax prevails extensively in parts of Russia, Turkey, and Persia (both 
 ' See Article by the \vi-iter m the Encijclopadia of Practical Medicine. London: Churchill. 
 
OFFENSIVE BUSINESSES 931 
 
 Asiatic and European, and parts of France and Germany. It is not at all 
 ;so common in North as in South America. The most dangerous wools 
 imported into this country are from the districts around Lake Van and 
 from Persia. 
 
 In the manipulation of damp materials, such as hides, the infection is 
 undoubtedly acquired by direct inoculation through breaches in the skin, and 
 it is improbable that it is, unless in exceptional cases, acquired by swallowing. 
 But in the manipulation of dry and very dusty wools and hair there is 
 liability of infection in any of three ways — either by inoculation through 
 wounds in the skin, by swallowing, or by inhalation. It is not necessary 
 to assume that in the case of virus which has been swallowed there must be 
 a wounded surface in the course of the intestinal tract, where absorption 
 takes place. It has been shown by Koch that the spores of anthrax may be 
 absorbed directly by the intestinal epithelium, and cause general infection 
 in this way.^ Although the bacilli of anthrax are capable of being destroyed 
 by digestion, the spores are able not only to resist the action of the gastric 
 digestive juices, but may pass with impunity through the whole intestinal 
 tract, if not absorbed into the tissues en route. 
 
 Woolsorters' disease, which has attracted considerable attention, is so 
 •characteristic that it may vath advantage be referred to in some detail as 
 Illustrating the mode of infection and the character of the disease. It occurs 
 as a local disease, an external sore, with or without general symptoms, or 
 the latter being present there may be no external sore. 
 
 That woolsorters were liable at times to suffer death and illness of a 
 peculiar kind was long known, and especially was this observed in the 
 Bradford district after the first importation of alpaca, a material unknown 
 there until about forty years ago. It was mainly owing to the indefatigable 
 -exertion of Dr. J. H. Bell, of Bradford, that the true nature of the disease 
 was ascertained to be anthrax. 
 
 The woolsorter is a person who divides the wool of a fleece into * sorts ' 
 •or classes of various quality, the coarser and finer portions being placed 
 together in separate bundles. For some purposes a fleece, e.g. of mohair or 
 alpaca, will be ' sorted ' into as many as six or eight ' sorts,' or as few as a 
 couple. The greater the number of sorts, the finer will be the character of 
 some of them. Fleeces of English, colonial, and other sheep's wool are also 
 * sorted,' but usually into but a small number of ' sorts.' 
 
 The ' sorter,' dressed in a cotton overall, termed in Bradford a ' brat,' 
 stands at his work before a sort of counter locally termed a ' sorting board,' 
 which has immediately in front of the sorter an opening covered with a 
 movable wire grating termed a 'hurdle.' The sorting of the wool is done 
 ■directly over the hurdle and the dust and other fine matter fall through it, 
 resting on the bottom, which is a few inches beneath the grating (' hurdle '). 
 The sorting-rooms are often very large, the ' sortmg-boards ' being placed 
 along the walls, opposite the windows. As many as thirty to forty sorters 
 may be engaged in one room. The rooms are usually bare of all other furni- 
 ture than the ' boards ; ' and too commonly the greater part of the floor 
 space is occupied with stored bales of wool. 
 
 When dry, dusty material is being sorted, such as alpaca, mohair, and 
 ■camel's hair, there is always a good deal of dust in the air of the room ; but 
 
 ' This fact is in Kocli's opinion a critical objection to the general adoption of Pasteur's 
 protective inoculation of animals against anthrax. He considers animals may be pro- 
 tected against infection arising from cutaneous inoculation ; but that this does not impart 
 protection against intestinal infection. 
 
 3o2 
 
932 HYGIENE 
 
 when sheep's wool is being sorted this is not the case, owing to its greasiness. 
 The prevalence of this dust may not only be judged by the eyes and touch, 
 but in a room which is not kept clean can be noticed by the quantities 
 adherent to the ceiling and walls. 
 
 It is usual in some cases to have the bales or large packages of wool 
 covered ^\ith coarse sacking, before they reach the sorting-room, opened. The 
 contents are considerably compressed in packing, and when the bales are 
 opened and the fleeces are shaken out there is a great cloud of dust raised, if 
 the material is of the character referred to (mohair, alpaca, &c.) When the 
 bales are opened in the sorting-room under such circumstances, the efifect is to- 
 distribute immense quantities of this fine dust throughout the room. Within 
 the bale each separate fleece is made up into a kind of rough bundle apart 
 from the others. Even an inexperienced eye must notice that some of these 
 fleeces or some parts of them are often covered with a good deal of filth,, 
 mud, dung, &c., though as a rule the smell is not ottensive. There is the 
 odour peculiar to the wool or hair, but even in the case of bales which un- 
 doubtedly contain anthrax virus there is very rarely anything which could 
 be termed a stench. 
 
 The history of a case of woolsorters' disease is very characteristic, though 
 mainly owmg to the absence at the outset of anything indicating danger to 
 the inexperienced. The sorter goes to his work in his usual health ; after 
 an hour or so, it may be, he feels giddy or ' queer ; ' but believing the feehng 
 will pass off he persists in working until at last he is obliged to go home. 
 ' Tightness ' in the chest is a common symptom at the outset, and there are 
 generally complaints of feehng chilly — indeed, the patient is usually convinced 
 he has caught cold. 
 
 In serious cases the fatal end may come in twenty-four hours, and it 
 is rarely postponed beyond three to four days. But there is no doubt that 
 many persons have slight attacks, with all the symptoms usually observed in 
 fatal cases, and are quite well in a lew days. 
 
 The further course of serious cases is chiefly marked by increasing 
 prostration. The pulse becomes feebler and more rapid, the breathing slow 
 and shallow, and the temperature falls. 
 
 The following are the precautionary regulations originally drafted by the 
 writer, and after modification agreed upon, as necessary for the prevention of 
 woolsorter's disease, by the Sanitary Committee of the Town Council of 
 Bradford, by committees of the manufacturers and woolsorters, and by the 
 coroner's jury upon the inquest held on the body of Isaac Saville in 1884 : — 
 
 1. All bales of wool or hair shall be opened by a person skilled in judging the con- 
 dition of the material, any woolsorter to be deemed such person if willing to perform the' 
 duty. If he find the contents unobjectionable they shall be sorted in the ordinary way. 
 If, on opening any bale, dead or fallen fleeces or damaged materials are found, such bale 
 shall be at once taken from the room where opened, and dealt with as noxious. All Van, 
 Persian, damaged wool, fallen fleeces, and foreign skin, wool, or hair, shall be deemed 
 noxious and shall not be opened in the sorting-room. Noxious wool or hair shall, before 
 sorting, be thoroughly saturated with water and then washed in hot suds, rolled and 
 sorted while damp, or if steeping would be injurious to the article, or would render 
 difficult the working of the material, then it shall be disinfected. 
 
 2. No noxious material (alpaca, pelitan, or East Indian Cashmere) shall be opened 
 in the sorting-room, but in a place specially set apart for the purpose, separate and 
 distinct from the sorting-room, and all such material shall be opened over a fan by a 
 person capable of judging the condition of the material. 
 
 3. The sorting-rooms for all classes of mohair, camel hair, Persian, Cashmere, and 
 alpaca shall be provided with extracting-fans so arranged that each sorting-board shall 
 be independently connected with the extracting-shaft, in order that the dust arising fi'om 
 
OFFENSIVE BUSINESSES 938 
 
 ■the material being sorted may be drawn dowmoards, and thus prevented from injuring 
 ihe sorter. 
 
 4. The dust collected by the fan must not be discharged into the open air, but be 
 received into properly constructed catch-boxes. It must be afterwards burnt. This must 
 be attended to at least twice a week. The sweepings from fioors, walls, and from under 
 the hurdles shall be similarly treated. AD pieces of dead skin, scab, and clippings or 
 ' shearlings ' must be removed weekly from the sorting-room, and must not be dealt with 
 •or sold until they have been disinfected. 
 
 5. All bags in which wool or hair has been imported shall be picked clean and not 
 brushed, and such bags shall not be sold or used for any other purpose until they have 
 been disinfected. 
 
 6. No sorter having any exposed open cut or sore upon his person shall be allowed 
 to sort. 
 
 7. A place shall be provided in which the sorters can leave their coats outside the 
 ■sorting-room, or in some suitable place covered over, during working hours. 
 
 8. Proper provision shall be made for the keeping of the sorters' food out of the 
 :sorting-room, or in a closed closet therein, during working hours. No meals shall be 
 taken in the sorting-room. 
 
 9. The sorting-rooms shall be well ventilated, by fans or otherwise ; but as this cannot 
 Ibe effectually accomplished by open windows only, power shall be employed to secure down- 
 ward ventilation, so arranged as to protect the workmen from draught. The windows shall 
 •be kept open during meal hours. The sorting-rooms shall be warmed during cold weather. 
 
 10. No wool or hair shall be stored in the sorting-room, unless the same be effectually 
 ^screened off from such room. 
 
 11. The floor of the sorting-room shall be thoroughly sprinkled with a disinfectant, 
 so as to allay dust, and swept daily after work is over. The sorting-room shall be 
 thoroughly disinfected and the walls thereof limewashed at least once a year. 
 
 12. Kequisites for disinfecting and treating scratches and slight wounds should be at 
 hand in the sorting-room, as thereby fatal consequences may be avoided. 
 
 13. Proper provision shall be made for the sorters to wash in or near to the sorting- 
 jToom. 
 
 14. A copy of these precautionary regulations shall be hung up in a conspicuous place 
 in every sorting-room. 
 
 Town Hall, Bkadford, August 8, 1884. 
 
 A great deal of benefit has been derived from these regulations, imperfect 
 .as they are. The necessity of compromise in getting such a set of regulations 
 agreed to by persons representing very diverse interests is obvious, and such 
 compromise unavoidably weakened the original draft proposals. The great 
 boon gained was the recognition of certain materials as being dangerous, and 
 the consequent responsibility attending their use. 
 
 In clause 1 it is obvious that ' any woolsorter ' should not be deemed a 
 person skilled in judging the condition of wools, &c. The object of selecting 
 :a skilled person is that he may be able to give notice to the head of the firm 
 if the material is unfit to deliver to the * sorters ' for sorting. Such knowledge 
 is not in the possession of ' any sorter,' but only of skilled and experienced men. 
 
 Further, it would be much better if it had been left optional to wash or 
 ■disinfect any kind of wool, instead of specifying that some kinds shall be 
 "washed, &c., and some disinfected. 
 
 3. These materials are specified as being notoriously dry and dusty. A 
 .general regulation applicable to all dusty material would be preferable. 
 There is no reason why the extraction might not be horizontal, instead of 
 downwards, if the circumstances of the building make such more suitable. 
 The object is to keep the objectionable dust from rising. 
 
 4. The general regulation to burn all dust is unreasonable and unneces- 
 rsary. The dust from such material might readily be rendered harmless and 
 valuable. 
 
 5. The object of this regulation is to prevent bags possibly infected by 
 ianthrax being sold and used for seating chairs, sofas, and other purposes, 
 
934 HYGIENE 
 
 and to prevent the creation of a great deal of dust in the sweeping of 
 them. 
 
 7. The alternative of keeping the clothes ' in some suitable place ' is 
 objectionable. It is understood to mean inside the sorting-room, and the 
 vague phrase ' suitable place ' Avill often mean any unsuitable place. The 
 sorters' coats, &c., should be excluded from the sorting-room. 
 
 8. Similarly in this regulation there should be rigid exclusion of food 
 from the sorting-room. 
 
 9. The warming of the rooms is not only necessary as a general hygienic- 
 regulation in the sorting-rooms, which are often very large and lofty, but it is 
 especially necessary for sorters, whose fingers may become numbed with cold, 
 and they do not readily notice slight cracks and scratches, the existence 
 of which is most dangerous. 
 
 10. The alternative here provided, as in other clauses, renders the regula- 
 tion practically useless. The prohibition was needed — 
 
 ((() To prevent danger from infected wool stored in the room, often for 
 months. 
 
 (b) To prevent sound wool thus stored from being infected by dust from 
 other wool. 
 
 (c) To prevent the cubic space required by the sorters being unduly 
 curtailed, and the free circulation of the air being impeded. 
 
 The ' screening off from the room ' may be effectual, and yet all the real 
 requirements of the regulation be set at nought. 
 
 THE CUEING OF BACON 
 
 There is one part of this business which is liable to be very offensive,, 
 apart from the processes with which it is often associated, and which may 
 themselves be offensive. This is the singeing of the hair of the pigs in pre- 
 paring the flesh for bacon. 
 
 After the pig has been slaughtered, it is ' scalded ' and Avashed, and then 
 scraped to remove the hair, without singeing ; but sometimes the hair is 
 singed before the scalding. Sometimes this is done, on a small scale, with 
 an ordinary instrument, such as is used for singeing horses, or an ordinary 
 gas-flame is used. At other times the carcase is placed for a few minutes 
 on a straw or a coal fire, or it may be suspended in the chimney so as tO' 
 catch the heat from the fire. 
 
 The most complete apparatus, probably, is Denny's patent j)ig-singeing 
 furnace ; an arrangement by which with a revolving apparatus one carcase 
 after another is introduced into the singeing place, the work being completed 
 in about twenty-five seconds, and the greater part of the effluvium passes up' 
 the chimney. 
 
 The stench from the burning hair is very offensive, and is often allowed 
 unnecessarily to become aggravated by the carcase being left still smoking on 
 the premises. A bucket of cold water thrown over it stops the smell at 
 once. 
 
 The drying of bacon is ordinarily effected merely by hanging it in a dry 
 airy situation, as for mstance near the kitchen ceiling. On a large scale 
 it is accelerated by the use of special rooms heated to about 95° F., the heat 
 being supplied by fires of coke, or smokeless coal in a fire-grate, or on a brick 
 flooring in the centre, openings being provided in the roof or Avails for the 
 escape of smoke. The ' smoking ' of the bacon and hams is effected by expos- 
 ing them to the fumes of burning wood, above which they hang, and the^ 
 
OFFENSIVE BUSINESSES 935 
 
 flavour is varied according to the wood used. Oak or elm shavings, or sawdust, 
 are most commonly used. 
 
 The fumes from the smoking chambers are pungent, unpleasant, and 
 may become a nuisance unless discharged into a chimney high enough to 
 secure their diffusion. But the smell of the singed hair is the chief nuisance 
 complained of in connection with this trade, and it can only be overcome by 
 the process being conducted in a closed chamber, and so that the fumes shall 
 be burned, or condensed, or both, and then discharged through a high 
 chimney. 
 
 There must always be difficulty in carrying on this business, and others 
 in which offensive effluvium is produced in crowded districts, and it is just 
 in crowded poor places that such businesses are most commonly found in 
 operation. 
 
 Another source of nuisance connected with bacon-curing is the brine, 
 which is sometimes used too long, and even after it has become offensive is 
 often allowed to stand on the premises until it is quite unendurable. The 
 mode of avoiding this nuisance is too obvious to need further comment. 
 
 The preparation of American pork in this country to make bacon may be 
 a source of annoyance from the warm liquor, in which the pork is steeped, 
 undergoing putrefaction, and being discharged into the drains. This annoy- 
 ance could be easily avoided. The process of preparing bacon from American 
 pork consists in first steeping it for about twelve hours in water to extract 
 excess of salt, then drying it in a hot, closed room, warmed by a charcoal 
 fire, and subsequently exposing it to a current of air. 
 
 MANUFACTUEE OP HOESE-HAIR 
 
 Horse-hair is chiefly used for making mattresses, stuffing chairs, making 
 cloth for covering chairs, sofas, railway-carriage seats, brush-making, &c. 
 
 The hair used is by no means exclusively horse-hair, though generally 
 known under that name. Cow-hair is used for the same purpose, but is 
 generally of a finer quality than horse-hair. Pig-hair also is largely used, but 
 not for weaving, being too short. As the treatment of all these hairs is 
 XDractically the same from the sanitary point of view, they will be all mcluded 
 generally in this article. 
 
 The manes and tails of horses are the parts used, and the tails of cows. 
 
 Except the best quality of horse-hair, all these are more or less dusty 
 and filthy. Sometimes the bales smell very unpleasantly. The hair has 
 commonly dung, earth, &c., attached to it, and sometimes even bits of skin 
 and even bones of the tail will be found attached. 
 
 After pieces of skin, &c., have been detached, the manufacture of long 
 hair may be said to commence with the sorting, or dividing the hair into 
 long and short, coloured and white. There is a good deal of offensive dust 
 stirred up during this process. 
 
 The hair is then washed, and when dry is combed, which straightens it 
 and removes short hairs (which are mixed with pig-hair and curled), and it 
 is then further divided into lengths, the longest being set aside for weaving. 
 The coloured hair is then dyed, the almost universal colour being black, 
 while the white hair is bleached by exposure to the fumes of burning sulphur 
 in a small closed chamber. The dyeing is usually done wdth logwood and 
 protosulphate of iron. 
 
 The short hair is sometimes dyed and sometimes is not. If very dirty it 
 is teazed and dusted in a ' willowing ' machine, similar to that used in the 
 
986 HYGIENE 
 
 wool trade. This consists of a closed box, within which revolve one large 
 cy Under and usually three small ones all being provided with spikes project- 
 ing from the surface. The hair being fed into the box, when the cylinders 
 revolve it is tossed about and opened out, the lighter dust being removed by 
 a fan, while the heavier falls to a false bottom placed between the true 
 bottom and the cylinder. The tine dust is commonly discharged into the 
 air — a very objectionable custom. The heavier dust is very good for manure, 
 for which it is generally used. 
 
 Short hair which is to be dyed is commonly dyed with the dirt on. Some- 
 times it is ' ■vsdllowed ' first. It is dyed by being boiled with logwood in a 
 large vat, commonly in the open, but (protected from the rain) by means of 
 steam discharged into the water. After some hours sulphate of iron (green 
 copperas) is added, the whole process lasting some six hours. The hair is then 
 removed to another vessel and washed, and if necessary that which has not 
 been previously ' willowed ' is passed through a dusting machine. The 
 liquor was formerly discharged direct into the sewers while hot, by which a 
 very offensive smell was created along the streets, and often inside houses, 
 as it ran through the drain-pipe. Now there is a statutory limit of 80° F., 
 above which temperature liquids are inadmissible into sewers. 
 
 The hair is curled by being first twisted into a sort of rope by the curling 
 machine ; by two subsequent operations it is further twisted till it assumes 
 a convoluted form, in which it is tied ; it is then steeped in cold water for 
 some hours, and on removal is placed in ovens at a very high temperature, 
 after which the curl is permanent. 
 
 In the neighbourhood of such works there is often great annoyance 
 created by the stench from the vapours of the dye-vat, and from the hot 
 liquor discharged into the drains. The former could be entirely obviated 
 by the use of a water-sealed lid, with hood and a flue conducting the 
 vapours into a cold-water tank or scrubber. The discharge of the vapours 
 into the chimney will be quite ineffectual unless it be of sufficient height. 
 The only efiect of discharging into a chimney insufficiently high is that, 
 instead of those near the works being affected by the stench, it will be 
 those at a little distance. The smell may extend for hundreds of yards, 
 and is often of a very sickening character, causing nausea and malaise, 
 and rendering it impossible to open doors or windows. 
 
 The remedy for the nuisance arismg from the liquor discharged into the 
 drams is not to discharge the liquor into the drains till cold, a precaution which 
 should be taken with all fluids discharged into the sewers in large quantity. 
 
 A more serious evil is infection with anthrax (knoA\'ii as woolsorters' 
 disease, charbon, malignant pustule), which undoubtedly occurs at times, and 
 probably more frequently than is suspected. It is due to infection by means 
 of virus attached to the hair from animals which have suffered from the 
 disease. There seems no reason why all dirty hair should not be boiled 
 and dyed before sorting, which would obviate the dangers of the dusty stage, 
 and probably disinfect thoroughly. Little is to be expected from the sug- 
 gested use of a respirator during sorting, because (Ij the disease is by no 
 means always taken by inhalation, but frequently by inoculation through 
 scratches, and (2) workpeople will not wear respirators of any form so far 
 known, findmg them too unpleasant. (Cf. Precautions agamst Woolsorter's 
 Disease, p. 932.) 
 
OFFENSIVE BUSINESSES 937 
 
 B. BUSINESSES IN WHICH KNOWN GASES OB VAPOURS OF 
 MINERAL SUBSTANCES ARE EVOLVED 
 
 MORBID EFFECTS ARISING FROM THE INHALATION OF GAS 
 
 Before referring to the notable and unmistakable reactions occurring in 
 the body in consequence of the inhalation of toxic gases, a word may be said 
 in reference to the action of certain gases, usually termed indifferent — i.e. 
 those which, when mixed in certain proportions with oxygen, do not cause any 
 decided morbid symptoms, provided the proportion of oxygen be not too small. 
 
 Those most deserving attention in this group are nitrogen, hydrogen, 
 marsh gas, and olefiant gas (respectively termed in modern nomenclature 
 methyl hydride, and ethylene). 
 
 Although the continued inhalation of a mixture of such gases with 
 oxygen may give rise to abnormal symptoms, especially if the proportion of 
 oxygen be low, it is not at all clear that the deficiency of oxygen is not the 
 source of the mischief, rather than the presence of the other gases. 
 
 Methyl hydride may certainly be regarded as a truly indifferent gas. It 
 seems that olefiant gas (ethylene) does possess certain toxic effects ; at least 
 certain unpleasant results of breathing the air of mines (coal) where it existed 
 have been attributed to its action, though by no means with certainty. 
 
 A rabbit confined in an atmosphere containing 30 per cent, of the gas 
 became narcotised in thirty minutes, its respiration having become tranquil 
 after a period of excitation. The animal recovered completely after one 
 hour. A pigeon exposed to a similar atmosphere died. It exhibited convul- 
 sive movements with its wings, difficult breathing, and lay with its head on 
 one side ; the pupils were dilated and the temperature diminished. The 
 autopsy showed the heart and veins filled with fluid blood ; the lung surface 
 bright red, with some brownish marbling ; the cut surface showed black 
 hffimorrhagic spots. 
 
 Ethylene is distinctly an anaesthetic gas. The morbid condition known 
 as ' miner's anaemia ' has been supposed to be due to the continued respiration 
 of air containing a considerable proportion of ethylene. It is more probable 
 that it is only one of the factors which leads to this serious and mysterious 
 morbid condition. When one considers the conditions under which a miner 
 spends his working hours, in almost absolute darkness, in an atmosphere 
 too often charged with moisture, or dust, containing many abnormal con- 
 stituents besides the gas in question ; further, when one takes into considera- 
 tion the nature of the work, the position, often most constrained, lying on 
 the back or side, &c., it will not seem surprising that some constitutions 
 should suffer. Among the most notable pathological phenomena of this 
 disease are the quantitative diminution of the blood-corpuscles, and their 
 greater or less disintegration, as well as the diminished secretion of sugar in 
 the liver. 
 
 MORBID CONDITIONS DUE TO THE INHALATION OF IRRESPIRABLE 
 
 GASES 
 
 It is not possible to draw too exactly the line which separates irrespirable 
 gas from those which are directly poisonous. By the former are meant gases 
 which produce readily or immediately great irritation of the respiratory 
 passages, generally leading in small quantity to cough, and in greater quantity 
 to spasmodic closure of the larynx. This salutary closure of the respiratory 
 
938 HYGIENE 
 
 tract prevents the further entrance of the noxious agent. Of the rapid action 
 of sulphurous acid gas, one of those included in the category, the writer can 
 speak from personal experience. 
 
 He was about to disinfect the operating-room of a hospital to which he 
 was surgeon, and had procured an alcoholic solution of sulphurous acid for 
 the purpose. The room had been prepared by the closure of all orifices, 
 except the door by which exit was to be made after the disinfectant had 
 been poured on the dishes arranged for it. At the last moment the solution 
 of sulphurous acid was poured out on the dishes, and the writer hastened to 
 the door, but before reaching it he fell, completely overcome by the fumes. 
 Had his fall not alarmed the nurses, who hurried to his help and dragged 
 him from the room, the result would probably have been fatal. 
 
 Sulphurous acid (sulphur dioxide) comes into consideration in a 
 variety of industries, in a greater or less degree — e.g. in the manufacture of 
 sulphuric acid, alum, glass, catgut ; in the manufacture of ' tin ' — that is, 
 really the tinning of thin sheets of iron ; in bleaching of certain kinds, 
 such as wool, cotton, silk, straw, &c. ; in the preparation of certain kinds of 
 * preserved ' foods (fruits, vegetables, meat, &c.) and on a very large scale in 
 the preparation of hops. These last are 'sulphured' to make them keep 
 Avhen dried. Wherever coal is burned, or minerals containing sulphur are 
 roasted, SO2 is also produced. 
 
 No very specific characters can be attributed to the effects of inspired 
 sulphur dioxide. Animals experimentally exposed to its action exhibit rest- 
 lessness, followed by depression and convulsions, which terminate fatally. 
 The heart and great vessels are found after death charged with blood, and 
 the muscular irritability is diminished ; the blood assumes a dirty brownish- 
 red colour. Accordmg to Hirt, sulphur dioxide has a direct paralysing action 
 on the vagus nerve, and affects the respiratory centre, sometimes as a 
 stimulant, sometimes as a paralyser, death resulting from paralysis of this 
 centre. 
 
 Weak dilutions of the gas (5-15 per cent. SO^) paralyse the vasomotor 
 centre rapidly, while strong ones (50-70 per cent. SO.,) produce this as a 
 secondary effect after a preceding stage of excitement. 
 
 The morbid effects produced by continued inhalation of SOo in weaker 
 dilution (e.g. 4-6 per cent.) seem at first to show themselves, not, as might be 
 expected, in the respiratory organs, although acute catarrh of the respiratory 
 organs is common enough, but in those of digestion. Even in a much weaker 
 dilution than that named the depraved air causes an acid taste in the mouth, 
 acid eructations, anorexia, irregularity of the bowels, and, as might be expected, 
 effects on the general health corresponding to these evidences of impaired 
 digestion. Hirt states that sometimes increased activity of the digestive 
 organs is observed where there is only a weak dilution of the gas, but others, 
 especially Eulenberg, deny this. 
 
 Hirt lays especial stress on one result of his experience — \\z. that most 
 commonly the continued inhalation of a weak dilution of SO2 may not be 
 directly capable of con\'iction of causing disease of the respiratory tract, but 
 that it is eminently calculated to produce a morbid condition of that portion 
 of the body, which ultimately leads with great certainty to disease. 
 
 In the bleaching of straw hats, these are loosely packed in a box and 
 exposed to the fumes of SO2 for some hours. 
 
 That workmen who are exposed in a confined space to exhalations which, 
 when they escape into the open air, kill the plants in the neighbourhood, and 
 cause great annoyance to those li%dng near at hand, should suffer in their 
 health is what must be expected. Although it may be impossible to apply a 
 
OFFENSIVE BUSINESSES 939 
 
 chemical test, and show by a chemical reaction that the SO^ is the cause, 
 still common-sense and humanity alike claim for the workmen in such a case 
 the protection of the law. 
 
 It is an obvious suggestion that workshops where fumes of this character 
 are produced should be under strict sanitary supervision, and that they should 
 be so situated as not to prove a nuisance or injurious to neighbouring 
 houses. 
 
 Wherever workmen are unavoidably exposed to SO.^, it is most important 
 to employ means to secure its being prevented accumulating in the place by 
 proper ventilation, which will ensure the exit of the gas and the supply of 
 pure air. 
 
 Should a dangerous amount of the gas be present in any place, various 
 means may be employed to diminish the danger. First, of course, comes 
 free ventilation ; but in addition it will be useful to use — 
 
 (1) Absorbent media, such as water sprinkled about, alkalies, &c : milk 
 of lime is very useful ; metallic oxides — e.g. those of copper or iron ; organic 
 substances — e.g. sawdust well warmed is also an excellent absorbent. 
 
 (2) Oxidising media — e.g. lead dioxide, manganese dioxide. Sulphuretted 
 hydrogen also reacts with SO2, with production of sulphur. 
 
 CHLORINE 
 
 Chlorine is used in various forms in enormous quantities in the arts. As 
 a bleaching agent it is largely used for the rapid bleaching of cotton and 
 linen goods (but not of woollen, silk, or straw '), bones, ivory, glycerine, also 
 in certain kinds of printing on stuffs (Turkish red), and dyeing. 
 
 Chlorine is usually developed from manganese dioxide, sodium chloride, 
 and sulphuric acid, the sodium combining with the sulphuric acid and liberat- 
 ing the chlorine. The prevention of the escape of chlorine from the vessel 
 is a most important matter for the workmen. 
 
 Inhalation of chlorine for some time produces effects very similar to the 
 inhalation of ammonia. But large quantities in the air (10-20 per cent, 
 chlorine) quickly leads to inflammatory action in the respiratory tract, and 
 even extensive pneumonia. Spasm of the glottis occurs, but soon relaxes, 
 and is certainly not the cause of death, which seems rather due to paralysis 
 of the heart. A rabbit placed in an atmosphere of chlorine in three minutes 
 became dizzy and fell ; and death ensued in five minutes, with slight convul- 
 sive movements of the extremities and deep spasmodic inspirations. The 
 brown-red, black spotting of the lungs is characteristic of death from inhala- 
 tion of chlorine. The finer bronchi are filled with a froth, and the mucous 
 membrane of the trachea and bronchi are discoloured brown. The lungs 
 may be in part condensed and firm to the touch. The blood is of a thick con- 
 sistence, and is sometimes granular. 
 
 According to Hirt, chlorine workers suffer much in general health, from 
 450 to 500 per 1,000 requiring treatment during the year for internal ailments, 
 not from actual chlorine-poisoning, which cannot be said to exist, but from 
 results of its irritating action. The respiratory organs are the first to suffer, 
 the irritating gas causing cough, sneezing, hoarseness, great irritation, 
 and even inflammation of the larynx. The coughing fits may be so violent 
 as to lead to bleeding of the nose, and even fatal haemorrhage from the lungs. 
 The action of the gas on the mucous membrane of the nose and mouth may 
 lead to loss of both smell and taste. The general discomfort may increase 
 
 ' See abo^^ 
 
940 HYGIENE 
 
 till giddiness occurs, and this may end in sudden asphyxia, which, however, 
 usually terminates on exposure to a plentiful supply of fresh air. Death 
 under such circumstances is not common. 
 
 Still though such fatal occurrences are rare, general bad effects result 
 from continual exposure to an atmosphere laden with chlorine. The work- 
 men lose their healthy colour, age quickly, and look pale or greenish. 
 
 The commonest form of internal disease among workmen engaged in 
 this trade is acute catarrh, which may end in acute pneumonia. Where 
 other diseases, or tendency to disease, exists (e.g. phthisis) it is tolerably 
 certain that the continued irrritation of the respiratory tract will maintain a 
 condition highly favourable to the progress of the disease. 
 
 As a protective, the inhalation of alcoholic solution of ammonia has been 
 recommended. Eulenberg recommends in preference the carrying of sponges 
 moistened with alcohol before the mouth and nose, and rightly condemns 
 the inhalation of anihne (recommended by Bailey). The use of the latter may 
 prevent the pungent smell, and irritation of the throat, but by the formation 
 of cliloraniUne may do serious harm to the workmen. 
 
 The frequent occurrence of pyrosis among the workmen is due, no doubt, 
 to the actual swallowing of abnormally acidulated saliva. The indigestion 
 •due to this excess is responsible for much of the ill-effect above referred to 
 as being observed among workers where chlorine is produced. Careful atten- 
 tion to dietary is obviously one of the hygienic regulations most needed. 
 
 BRICK-MAKING 
 
 Bricks, tiles, &c., are formed from a great variety of clays, differing 
 greatly in physical character. The clay has to be ground and mixed with 
 water, after which it is allowed to dry to the proper consistence. Sand, 
 chalk, ashes, or fine coal, are added sometimes, and even the miscellaneous 
 cUhris of dustbins. When bricks are to be burned in a kiln combustible 
 matter is usually not added to the clay. 
 
 Bricks are burned either in ' clamps ' or ' kilns.' The former method 
 consists in building the bricks into a pile 8 to 10 feet high, with alternate 
 layers of fine breeze (cinder), air-passages being left at suitable intervals. 
 When a clamp (or pile) of sufficient size has been made, which may mean 
 half a miUion to a million and a half bricks, fires are lighted around it, by 
 which the breeze is ignited, and by this means the combustible matter in the 
 bricks themselves is also put into a state of slow combustion. When this 
 has been all consumed the combustion ceases. 
 
 When the bricks are burned in a kiln, fuel is used in much larger quanti- 
 ties than in the ' clamp ' process. In some kilns the top is open, and the 
 •effluvium escapes ; in others it is closed, and the smoke, vapours, and gases 
 escape by a chimney. In the former the bricks are built up pretty much as 
 in the clamp process, but a considerable space is left at intervals between the 
 bricks to serve as receptacles for fuel, some of the orifices being closed by 
 plaster to retain the heat at a certain stage. It takes about 12 to 14 days to 
 complete the making of bricks by this process. The closed kiln consists of 
 a low brick building, with openings at the top and sides for filling, stoking, &c. 
 
 Within tbese the ' green ' bricks are built up, and they are so arranged that 
 when at work the draft ascends inside along the walls and descends through 
 the bricks to the flue leading to the cbimney, the flue being underground ; 
 in other forms the chimney rises from the centre of the oven. The Hof- 
 mann circular kiln has acquired a deservedly wide reputation as one of 
 the best for large work, as it requires little fuel and burns it thoroughly. 
 
OFFENSIVE BUSINESSES 941 
 
 For smaller works other forms of close kiln are in use, which are a great 
 improvement on the clamp process. 
 
 There is no town which is growing quickly where there has not been 
 trouble from the effluvium arising from brick-making. That given off by 
 the clamp process is sometimes very offensive, the degree depending a good 
 deal on the nature of the material, the proportion of organic matter, and 
 its character. The continuous issue of smoke at such a low level and its 
 smell, which is sometimes pungent and very disagreeable, are the chief sources- 
 of complaint. Sulphurous acid may be present in a very appreciable degree. 
 At the commencement of the burning the emanations are charged with 
 watery vapour, and often with sulphuretted hydrogen, carbonic acid, car- 
 bonic oxide, carburetted hydrogen, ammonia, &c. Offensive empyreumatic 
 gases are sometimes largely present also, arising from the combustion of 
 organic matter. When bricks or pottery are glazed, the nuisance becomes 
 much more serious both for the workmen and the neighbours. If salt is 
 used, chlorme is given off ; if sulphide of lead be employed, the danger arising 
 from the lead and the sulphur fumes is very serious. 
 
 This last source of nuisance could easily be removed by avoiding the use 
 of organic debris entirely, and using only small coke. The smoke nuisance 
 is largely due in this case, as in ordinary boiler fires, to the utter recklessness 
 with which the stoking is neglected, the red-hot and smokeless fires being 
 from time to time damped down with coal heaped on, instead of small quanti- 
 ties being put on at short intervals. The watering of the coal before it is 
 put on the fire has a very advantageous effect in diminishing the smoke 
 nuisance. 
 
 The nuisance is sufficient to cause actual fainting, oppression of breath- 
 ing, and other serious symptoms in persons much exposed to it. 
 
 MANUFACTUEE OP POETLAND CEMENT 
 
 Portland and Eoman cements are two kinds of hydraulic cements manufac- 
 tured in this country. Genuine Eoman cement is made from pozzuolana, a 
 ferruginous volcanic ash from Vesuvius and other Italian volcanoes mixed 
 with lime ; or from a combination of lime and trass, a kind of pumice from 
 the Eifel district of the Ehine. This material simply reqmres grinding. In 
 this country cement is made from the septaria^ from the London clay and the 
 Lower Lias formations, from cement stone of the Upper Lias, and from shale 
 beds of the Kimmeridge clay. It is also made by the calcination of mixtures 
 of lime and ferruginous clay. The septaria are calcined in open kilns, like 
 limestone, but the process does not give rise to much nuisance. 
 
 The manufacture of Portland cement, however, causes a serious nuisance 
 unless conducted with special precautions. It is made usually from a mix- 
 ture of about eighty parts of chalk or rich lime and twenty of clay or 
 alluvial mud. The materials are mixed wet, then dried, calcined, and pul- 
 verised. The clay used often contains much peaty matter, and even more 
 offensive materials, which give rise ultimately to the great nuisance com- 
 plained of. 
 
 The ingredients having been well mixed and brought to the proper con- 
 sistency (in which state it is known as ' slurry '), are dug out and dried, usually 
 on iron plates, heated either indirectly by flues from coke fires, or directly by 
 the fires themselves. When dried the ' slurry ' is placed in an ordinary kihi, 
 
 ' Nodules of clay, ironstone, &c., internally divided into angular compartments 
 (septa) by fissures, which are usually filled with a calcareous spar. 
 
942 HYGIENE 
 
 like that used foi* lime-burning, and calcined ; alternate layers of ' slurry ' 
 and coke being deposited in the kihi, and then lighted, the ' charge ' taking 
 usually (according to size) some three to five days to burn out. 
 
 The nuisance complained of is due partly to smoke and vapour, partly to 
 the smell, which is somewhat like that caused by brick-burning, but has also 
 a strong similarity to the odour of burning bones or other organic matter, 
 the character of the smell varying greatly, from very slight to very bad, 
 according to the nature of the clay used. 
 
 People exposed to these effluvia complain of a nasty taste in the mouth, 
 often of an acid character, of a dryness of the mouth and throat, and even of 
 vomiting and oppression of breathing. 
 
 The smell arises during the drying of the ' slurry,' but then it is very 
 slight compared with what is emitted during the calcining. It has been 
 found that sulphuretted hydrogen and compounds of cyanogen, probably a 
 cyanide of ammonium or sodium, a sulphocyanide, chloride of sodium, and 
 empyreumatic compounds are given off during this process. The common 
 salt given off in a state of very fine division increases the annoyance from the 
 more serious gases given oft'. The effluvia vary, as has been stated above, 
 considerably in different places, and do not everywhere contain all these 
 dangerous and offensive ingredients. 
 
 The best mode of preventing the danger is to pass the vapour collected 
 from the kiln by a suitable hood and flue, assisted by a fan if necessary, 
 through the furnace, and thence into a tall chimney. Attempts have been 
 made to deal with the nuisance by condensing and washing the fumes in a 
 cold-water scrubber, but not ahvays successfully^ 
 
 LIME-BUENING 
 
 Lime-burning consists in heating limestone or chalk in a kiln, which 
 causes it to decompose and form lime (quickhme) and carbon dioxide. 
 Lime is not found free in nature, but it exists in enormous quantities in 
 the form of carbonate. 
 
 The ordinary open lime-kiln is practically a sort of chimney, lined with 
 firebrick or reh'actory stone, and narroAving to the bottom, where the lime 
 is discharged. It is charged from the top with alternate layers of fuel and 
 limestone or chalk, and is fired from below. Such a kiln may be worked 
 contmuously, more layers of fuel and hmestone being charged above as the 
 lime is withdrawn below. 
 
 Closed kilns are also sometimes used, similar to the Hoffmann brick- 
 kilns (q.v.) 
 
 The nuisance from lime-burning is due partly to the carbon dioxide 
 evolved from the limestone or chalk as well as from the coal, partly to the 
 smoke, and also to the offensive fumes evolved from the fuel, which is burned 
 slowly, and not briskly as in an open fire. Carboniferous limestone causes 
 a much greater nuisance than other materials used for lime production. 
 
 Death may arise from continued exposure to the fumes, as when persons 
 lie down to warm themselves, fall asleep, and die. Continued exposure to 
 the fumes leads to very serious symptoms — debility, loss of appetite, great 
 drowsiness, and general nervous derangement. The results are probably 
 due 10 the carbonic oxide. 
 
 Much of the nuisance is due to the quality of the fuel, which should be 
 good coal or coke (not inferior shaly material). Inferior coal causes greater 
 nuisance, greater waste, and makes worse lime. Besides the use of better fuel, 
 a tall chimney should be used to discharge the fumes at a sufficient height. 
 
OFFENSIVE BUSINESSES 943 
 
 Spencer's patent kiln consists of two egg-shaped chambers, one above the 
 other and communicating one with the other. The hmestone is charged in 
 at the top, and the fuel by openings made lower down. The heat from the 
 lower chamber warms the stove in the upper before it descends into the 
 calcining chamber. 
 
 CAEBONIC OXIDE (Cai!i;on Monoxide, CO) 
 
 This gas is formed when carbon burns in a scanty supply of air. It is 
 a colourless, tasteless, and odourless gas, rather lighter than air (sp. gr. 
 = 0"97). It is present in ordinary coal fires, the vapour of burning charcoal 
 (from 0-34 to 2*54 per cent.), in ordinary illuminating coal gas and ' water- 
 gas,' and in the gases resulting from explosions of gunpowder ; it is given 
 out in large quantities in the smelting of iron ores, in the making of coke 
 and of wood charcoal. It is a deadly poison when inhaled, all the more 
 dangerous in that it indicates its presence in no way to the sense of sight, 
 taste, or smell, is not irritating to the respiratory or digestive organs, and 
 that, exercising a narcotic and paralysing effect, it lulls the sensations and 
 causes insensibility without arousing any desire or effort to escape the danger. 
 
 It is not often that accidents arise from inhalation of pure carbonic oxide ; 
 its fatal effects are almost always observed after absorption of a mixture of 
 CO along with other gases, most commonly with coal gas or charcoal 
 vapour (which is largely a mixture of CO2 and CO), CgH^ (defiant gas, 
 heavy carburetted hydrogen), aqueous vapour, partially deoxidised air, &c. 
 The abstraction of the CO2 from this mixture, of which it forms a large part, 
 does not in the least deprive it of its poisonous characters, which are there- 
 fore undoubtedly due to carbonic oxide. It is present in the vapours from 
 blast-furnaces, along with CO2 ; and fatal results have been caused by 
 inhaling it in the vapours from smouldering ashes. In the case of ordinary 
 illuminating gas, which is also a mixture of gases in variable proportions, 
 the same dangerous element predominates, being present to a varying pro- 
 portion (4 to 6 per cent.). The presence of the other constituents of coal gas 
 in the inspired air of a room no doubt assists in rendering the action of 
 the carbonic oxide more marked, and the presence of 0*53 per cent, will pro- 
 duce symptoms of intoxication, while 1*5 per cent, will cause the death of 
 animals experimented on. 
 
 The so-called ' water-gas,' which has come much into use of late years, 
 mainly for heating purposes, consists mainly of carbonic oxide and hydrogen, 
 the former usually forming one-third by volume, or even 40 per cent. It 
 is developed by the action of glowing carbon on superheated steam. The 
 great danger arising from the nature of this gas, and the absence of odour 
 to indicate its escape, have led to some strong- smelling gas, e.g., sul- 
 phuretted hydrogen, mercaptan, ethyl hydrosulphide, or pyridine, being 
 mixed with it to serve as an indicator. Two deaths were caused at a 
 manufactory in Leeds in 1889, owing to the escape of this gas, which was 
 used for heating purposes, through a stopcock not bemg properly turned off. 
 
 When gunpowder is exploded the relative quantity of the gases found 
 vary according to the proportion of the various constituents, and also 
 according to the pressure. The carbon dioxide increases with the pressure, 
 while the carbon monoxide diminishes. According to Eoscoe and Schorlem- 
 mer, the proportion of CO and CO2 present in different kinds per 100 was as 
 follows : — 
 
 No. 1 No. 2 No. 3 No. 4 
 Carbon monoxide . . . 0-94 1-18 1-47 2-64 
 
 Carbon dioxide . . . 20-12 22-47 21-79 17-39 
 
944 HYGIENE 
 
 Exposure to the action of gunpowder-vapour (mine gas) has heen linown 
 to have fatal effects. 
 
 Carbon monoxide when inhaled may cause death by acute poisoning in from 
 a few minutes to forty-eight hours, or it may induce chronic intoxication 
 lasting weeks or months, when it is inhaled in small quantities for a con- 
 siderable time — e.g. from charcoal fumes or coal gas. An atmosphere con- 
 taining 5 to 6 per cent, of CO will kill animals, and 10 per cent, is very fatal. 
 Its poisonous effects are increased by the presence of COj. An atmosphere 
 containing only 0*5 per cent, of CO proved fatal to a dog when 5 per cent. 
 of CO 2 was present, neither gas being present in a quantity which by itself 
 would be fatal. 
 
 The cause of death is a true poisoning, and is not merely to be regarded 
 as due to a deficiency of oxygon in the air. The carbonic oxide combines 
 with the Inemoglobiii of the blood. The union, however, is of such a 
 character that the carbonic oxide can be abstracted by pumping. 
 
 The appearance of the blood in cases of poisoning by this gas is very 
 peculiar and characteristic : it is of a bright cherry-red, and retains this 
 colour sometimes for months. AVhen examined by the spectroscope it shows 
 also a characteristic reaction. Carbonic-oxide hemoglobin shows two absorp- 
 tion bands between the D and E lines, and is irreducible by ammonium sul- 
 phide. This spectrum is entirely different from that of blood altered by 
 dyspnoea, involving insufficient oxidation, with retention of carbon dioxide. 
 Even in the most acute cases of dyspnoea, the two characteristic bands of 
 oxidised h!T?moglobin never disappear. 
 
 The earhest symptoms, where the patient is not acutely and suddenly 
 poisoned, are nervous headache, giddiness, specks seen before the eyes, and 
 sometimes hypertesthesia of the skin ; the giddiness may terminate in complete 
 unconsciousness and anaesthesia, if the absorption of the poison be continued. 
 Later there is nausea and vomiting. The pulse, which was at first accele- 
 rated, becomes slower, and the respiration also. Sometimes convulsions 
 occur. Paralysis of the sphincters is observed with more serious nervous 
 symptoms, as well as the appearance of sugar in the urine. The prognosis is 
 doubtful ; if the unconsciousness continues for some time it becomes very 
 grave. 
 
 Difference in SymjJtoms of Poisoning by Carbonic Oxide and Carbon 
 
 Dioxide 
 Carbonic Oxide. Carbon Dioxide. 
 
 Absence of dyspnoea. Dyspnoea. 
 
 Muscular weakness (paresis), coma Muscular debility. Deep coma. 
 
 slight or absent. 
 Convulsions. 
 
 Hyperiemia of heart and brain. 
 
 Blood, bright cherry-red. Heart and lungs filled with dark 
 
 blood. 
 
 The treatment must be directed, fii^st, to the immediate removal of the 
 patient from the dangerous atmosphere, and secondly, to artificial respiration, 
 which must often be maintained for hours. Friction of the surface, and 
 massage to encourage the circulation, and the electrical stimulation of the 
 phrenic nerves, are rational proceedings, the faradic currents being applied. 
 These are the essential means to be adopted, which must not be neglected 
 for efforts to administer any of the hundred and one internal remedies 
 which have been recommended. In grave cases it is also advisable to remove 
 
OFFENSIVE BUSINESSES 945 
 
 the poisoned blood, and introduce fresh, blood, or better still, a solution of 
 salt by transfusion into the veins. 
 
 CAEBON DIOXIDE (Caebonio Acid, CO,) 
 
 is a colourless, odourless gas, with a slightly acid taste, and is rather more 
 than one and a half times heavier than atmospheric air (1 : 1-53). It exists 
 in air to the extent of about 4 per 10,000 volumes. It is also produced in 
 fermentation, in the burning of limestone, in deep wells, drains, coal mines, 
 and other deep excavations (where it is known as choke-damp) ; even in grave- 
 digging serious accidents have occurred ; and it is evolved in great quantities. 
 in the artificial cultivation of yeast. The gases developed in the explosion of 
 dynamite also contain CO2 in large quantity. Pure CO2 is irrespirable, causing 
 spasmodic closure of the glottis ; when diluted with about twice its volume of 
 air it is respirable. The mixture of pure CO2 with air, it must be noted, is 
 a very different matter from a mixture with air in which the CO2 has been 
 developed by combustion or respiration, which implies not only production 
 of CO2 but abstraction of oxygen, every volume of CO2 produced by combus- 
 tion implying the abstraction of an equal volume of oxygen. In an atmo- 
 sphere containing 10 per cent, of CO2 developed by combustion, there will 
 be 10 per cent, less oxygen, not to mention other modifications of the normal 
 constitution atmosphere. 
 
 The exact proportion which must be present in the air to produce fatal 
 effects is not known, and no doubt is variable, being influenced by individual 
 circumstances, as well as — above all things — by the time during which it is 
 inhaled, and the presence or absence of other noxious gases. No doubt a 
 smaller qua,ntity would produce effects culminating in death if carbon dioxide 
 were present with other injurious gases, than if it was mixed with pure air. 
 It may be assumed that 10 to 20 per cent, is a dangerous amount. 
 
 Carbon dioxide cannot support combustion, and respiration and life are 
 soon extinguished where it is present in such proportion as that stated above. 
 That CO2 is in itself a poison and does not produce toxic symptoms merely 
 indirectly by accumulating in the blood to the exclusion of oxygen, seems 
 probable, though the question is still undecided. 
 
 The more prominent symptoms of its absorption are headache, noise in 
 the ears, giddiness, after which some persons exhibit excitement, others de- 
 pression, according to individuahty apparently. Loss of consciousness and loss 
 of power of movement are common symptoms in serious cases. The effects may 
 last from a few moments to two to three days. There is nothing distinctly 
 characteristic to be observed after death. The diagnosis can only be esta- 
 blished with any degree of certainty from the history of the case, which, 
 with the symptoms, usually gives sufficient indication of the nature of the 
 mischief. The prognosis is less unfavourable than in poisoning with carbonic 
 oxide, and is generally favourable, except in cases of acute poisoning continued 
 for some time ; in all cases the individuahty, duration of exposure, propor- 
 tion of gas present, &c., form essential elements in the prognosis. 
 
 The treatment is the same as for poisoning vsdth carbonic oxide except 
 as regards transfusion. It is very important that any collection of carbonic 
 acid suspected at the bottom of wells, excavations, &c., should be thoroughly 
 removed before men are allowed to venture in. To effect this evacuation is 
 often a matter of great difficulty. Gunpowder may be exploded at the 
 bottom, or limewater poured in, or baskets of hme suspended at the bottom, 
 or water in the form of a spray introduced, or the gas may be set in move- 
 ment by boughs, &c., being rapidly drawn up and down by means of a cord. 
 
 VOL. I. 3 P 
 
D-IG HYGIENE 
 
 It is commonly supposed that where a candle ■udll burn there cannot be 
 present a dangerous proportion of CO^. But this is not true. A candle will 
 bum readily in air contaunng 5 to 6 per cent, per volume of CO.,, and will still 
 continue to burn where there is 10 to 12 per cent. Even the smaller amoimt 
 would soon produce serious symptoms, but the larger would ere long cause 
 giddiness, coma, and death. 
 
 In a room, &c., where carbonic oxide has been present in a dangerous 
 quantity, it is not safe to trust in the fact that a candle will burn as an in- 
 dication that the danger has been removed, as oxycombustion may continue 
 where life will be extinguished. Such a place should not be entered imtil it 
 has been thoroughly ventilated. 
 
 COAL GAS 
 
 Coal gas is a mixture chiefly consisting of marsh gas (CII,!), hydrogen, 
 olefiant gas (CoH,,), carbonic oxide (CO), and impurities. 
 
 The following is given as an analysis of average coal gas when fairly 
 purified : — 
 
 Parkes Boscoe 
 Per cent. 
 
 Hydrogen— H 40-45-58 47-60 
 
 Marsh gas (light carburetted hydrogen) — CH^ . 35-40 41-53 
 Olefiant gas (heavy carburetted hydrogen) — C^H^ 3-4 8-05 
 
 Carbon monoxide— CO 3-6-6 7-82 
 
 Carbon dioxide— CO. 3-3-72 
 
 Acetylene- CH, . ' 2-3 
 
 Sulphuretted hydrogen— ILS .... 0-29-1 
 
 Nitrogen— N 2-2-5 
 
 Sulphurous acid— SO. 0-5-1-0 
 
 Ammonia or ammonium sulphide — NHaOr (NH|)_,S 
 Carbon bisulphide — CS. ... 
 
 The carbon dioxide may run to double or treble the amount here given, 
 or even higher, and the marsh gas may be as high as 56 per cent., in which 
 case the hydrogen is small. The statutory maximum of sulphur allowed 
 is 20 grains per 100 feet, but as much as 60 grains has been found, and 
 it is required that there shall be no sulphuretted hydrogen present. 
 
 The principal stages of the manufacture of gas are as follows. The 
 coal is first distilled in large cast-iron or fireclay retorts, set in brickwork, 
 which hold 2 to 3 cwt. of coal each, and are heated by coke fires from with- 
 out. The charge takes from four to six hours to distil. The result of this 
 process is the production of coke, which remains in the retorts, and various 
 volatile products, including various gases, tar, and an ammoniacal liquor 
 termed gas liquor. The tar and liquor are condensed in tubes six to nine 
 inches in diameter, and are collected in reservoirs placed beneath. 
 
 At this stage the gas is very impure. Some of its constituents, ammonia 
 and carbon dioxide, are not combustible ; sulphuretted hydrogen and bi- 
 sulphide of carbon have a most unpleasant smell and produce irrespirable 
 gases when burned. To effect the removal of other impurities the gas is 
 passed through coke scrubbers, where it deposits some of the ammonia, 
 with some of the carbonic acid and sulphuretted hydrogen as carbonate and 
 sulphide of ammonia. 
 
 The most important impurity to be got rid of subsequently is sulphur, which 
 is present in all coals, but especially in inferior qualities. The combustion 
 of sulphur evolves SO.2, the presence of which is not only dangerous in large, 
 but is unpleasant even in very small quantities, and is most injurious to plants, 
 and bleaches coloured objects of various kinds, tarnishes gilding, and almost 
 
OFFENSIVE BUSINESSES 947 
 
 all metal.1. The sulphur which exists in the gas at this stage, chiefly in 
 combination with hydrogen, ammonia, and compounds of carbon and 
 hydrogen, is removed by treatment with lime, which also removes carbon 
 dioxide and cyanogen, which last is generally present in small quantity. 
 As ammonia does not combine with lime, a great quantity of this valuable 
 material may thus be lost. As a purifying agent, that known as Laming' s 
 was long in great repute, but is now not much used. It consists of one equi- 
 valent of lime and one of ferrous chloride, to which chloride of calcium 
 and oxide of iron are subsequently added. When impure gas is brought 
 in contact with this, the ammonia and carbonic acid combine with the chlo- 
 ride of calcium to form carbonate of calcium and chloride of ammonium, 
 whilst the sulphuretted hydrogen is resolved into sulphide of iron and 
 sulphur by the oxide of iron. 
 
 The process of manufacture varies somewhat in different manufactories. 
 For instance, instead of the above, the following stages and methods are 
 sometimes employed : — 
 
 The impure gas from the retorts, after condensation in upright tubes, 
 is passed through scrubbers consisting of coke, and next through a water 
 scrubber in constant motion, where the ammonia is absorbed (and where 
 the valuable ammoniacal liquor originates) ; the gas is then passed through 
 three oxide of iron ' purifiers ' in succession, in order to get rid of the sulphur. 
 After this it is passed through lime to purify it from carbonic acid, being 
 passed thence to the station meter, and from there to the gasometer. 
 
 The oxide of iron, after being subjected to the action of the impure gas, 
 turns almost black in colour, which occurs when it has absorbed some 4 to 6 
 per cent, of sulphur. The time required for this will vary, of course, with 
 the relative quantity of gas and oxide. In large well-managed works, when 
 in full activity, the quantities are so balanced that the oxide is changed 
 about every three to five days. It is then taken out, spread on the ground, 
 and exposed to the air to be revivified, being turned over and over if necessary. 
 This process requires, under favourable circumstances (good weather, abun- 
 dant space, &c.), some two to four days. As it becomes ' revived ' it gets 
 gradually lighter in colour, turning to brown. It is then returned to the 
 purifier for further use, and after serving its purpose there is again 'revived,' 
 and again taken out. Ultimately, when it has taken up as much sulphur 
 as possible, which may reach 50 to 70 per cent., it is taken to chemical 
 works, and the sulphur it has taken up is utilised for the manufacture of 
 sulphuric acid, if that process of utilisation is employed. 
 
 The gas-lime has a strong and offensive smell, and is not easy to dispose 
 of. It is unsuitable as manure until after long exposure to the air ; and it 
 must not be discharged into streams, nor buried in the earth, as it would 
 soon pollute wells and streams, and its vapours may be carried a long 
 way subterraneously. Salts of iron are the best means of rendermg it 
 harmless. 
 
 Laming's purifier becomes regenerated by exposure to the air, the iron 
 becoming oxidised and the sulphur set free ; but large airy sheds are required 
 for the purpose, and its emanation may be very offensive. 
 
 The gas is conducted from the purifiers into the gasometers, vast recep- 
 tacles which are placed in excavations in the earth reaching to a great 
 depth, and in which water is collected to seal the gasometers and prevent 
 the escape of gas. 
 
 The employment of gas involves important sanitary considerations, which 
 are even more important for those who have it introduced into their houses 
 for use as an illuminating and heating agent than for the makers of it ; 
 
 3p2 
 
9i8 HYGIENE 
 
 indeed, the ■workmen, as a rule, do not suffer much from the specific product 
 they manufacture. 
 
 Dui-ing the removal of the gas-lime from the tank it is liable to cause 
 considerable irritation to the nose and eyes, through the dust and vapours of 
 cyanogen compounds and ammonia given off. The care required to be 
 taken in disposing of the gas-lime has already been referred to. 
 
 The construction of the underground receptacles of the gasometers re- 
 quires to be of the best kind to prevent leakage, and the escape of the water, 
 charged as it often is Avith tar, carbolic acid, &c., by which water-supplies, 
 &c., may be rendered unlit for use entirely, or for very long periods. Some 
 of these gasometers are of immense size, many holding over 8,000,000 cubic 
 feet of gas. One to hold 12,000,000 is now beuig built at North Greenwich, 
 and the depth of the excavated bed may reach to 30 to 40 feet. 
 
 It is a matter of no small importance that effective precautions be taken 
 to prevent either the escape of gas from the pipes, as they pass underground, 
 or the entrance of air into them ; water getting into smaller pipes causes 
 inconvenience by the flickering ('bobbmg') of the hght. Gas escapmg 
 through the ground may travel long distances, and enter dwelling-houses,, 
 and produce serious and even fatal effects ; it may injure water-supplies, and 
 it is very mjurious to trees, the roots of which are exposed to its action ; they 
 soon shed their leaves and die. 
 
 Coal gas when mixed with air in the proportion of 1 volume to 8 to 12 is 
 highly explosive, but even 1 volume to (3 to 7 is dangerous. 
 
 The sanitary considerations with regard to coal gas by no means terminate 
 with the completion of its manufacture. Owing to its constant presence in 
 the gas pipes wMch ramify in every direction through our houses, and often 
 allow of escapes of gas, the most careful supervision is called for. The escape 
 of a large quantity of gas speedily betrays itself by the smell, but small quan- 
 tities may be escaping continually without producmg any characteristic 
 odoiu', and yet may cause very serious effects. Gas may lose its smell easily 
 enough, even when escaping in considerable quantity, if it has to filter through 
 even a small thickness of wall, or through the floor of an ordinary house, 
 where the pipe hes between the floor of an upper room and the ceihng of 
 that below. Of course the deodorisation will depend on the quantity, pres- 
 sm-e, &c., and the speed with which it passes through the obstacles. It is 
 generally supposed that so little as 0*5 per cent, of gas in the air of a room 
 will produce a readily detectable smell. But in a room which is con- 
 stantly occupied, where there is much furniture (which always gives off' 
 a certain amount of odour), several gas lamps (which often have more or 
 less smell, and a very decided one if there be an india-rubber connection 
 with the gas), a great deal more than that proportion will not attract notice, 
 especially if the occupants of the room be inured to the presence of gas, and 
 are thus rendered to some extent abnormally defective in sensitiveness of 
 smell. 
 
 Among the worst of the products of combustion of coal gas are sulphuric 
 acid, which may sometimes be tasted on the surface of objects in a room with 
 bad gas ; and carbon monoxide, of which a considerable quantity is given off' 
 when gas is only partially burned. 
 
 But it is in bedrooms that the effects of escapes of gas, often trivial and 
 not noticed, are likely to be most harmful. During the day and evening 
 people are more or less in movement : the doors are frequently opened and shut, 
 the room is more or less ventilated by these means, and perhaps by the fire. 
 But a person remains in bed usually from six to eight hours, hi an atmosphere 
 which is scarcely in movement, and is very commonly hardly ever renewed, 
 owing to the common habit of keeping the bedroom door shut ; the bed is 
 
OFFENSIVE BUSINESSES 949 
 
 often intentionally placed with the head close to the gas bracket, and, as 
 one goes to bed with the intention of sleeping, it is not noticed whether some 
 drowsiness may not be attributable to a shght escape of gas instead of to 
 natural causes. The writer knows of many cases of chronic illness entirely 
 due to absorption of gas in this way, the patients recovering completely 
 when they were removed to another bedroom where there was no escape. 
 He was himself a great sufferer for several weeks, and quite incapacitated 
 from work, owing to an escape of gas between the floor of his bedroom 
 and the ceiling of the room beneath. The gas had quite lost its characteristic 
 odour in passing through the floor and carpet, although the quantity was suffi- 
 cient to make a large flame when a light was applied at the point of escape. 
 
 As an illustration of the remarkable way in which coal gas may be drawn 
 into a house from an escape in a main outside, the following tragical 
 history, investigated by the writer, is most instructive. It occurred in 1682 
 in the town of Glossop. In front of a couple of cottages in the outskirts 
 of the town ran an iron gas-pipe, two to three inches in diameter, some eight 
 to ten inches under the surface of the ground. This pipe had supplied 
 a mill beyond the cottages ; but the mill being disused at the time of this 
 occurrence, the end of the pipe was plugged, but the pipe continued full 
 of gas. The cottages were not supplied with gas. The pipe was about 
 three yards from the front wall of the houses. A woman, her two children, 
 and a man lived in the cottage nearest the town. As none of the inmates 
 of this cottage were seen during the whole of one day, and no sound was 
 heard, the neighbours (who, as the day wore on, noticed the smell of gas) 
 forced an entrance. On getting through the front door they were almost 
 suffocated by the smell of gas, and on making their way upstairs they found 
 iilae man and the two children dead, and the woman in her last moments. 
 It was found that the gas-pipe was broken (probably by a cart which 
 delivered a load of coal at the house on the previous evening) underground 
 about five yards from the dwelling-house. An outhouse built in connection 
 with the house intervened between the broken pipe and the house. The gas, 
 therefore, had traversed all this extent of earth, had passed through the 
 foundation wall, and, having first narcotised the mifortunate victims, ulti- 
 mately killed them. 
 
 It is a most remarkable fact that, the pipe being laid close to the 
 surface, the gas did not all escape above ground instead of travelling so 
 far underground into the house, the surface being only ordinary earth, 
 hardened by traffic of feet only. There was only one fireplace in the house, 
 and that downstairs ; in the room upstairs, where the victims lay, there was 
 none. This aspiration can only be attributed to the warmth of the house. 
 The outside air and earth would not be very cold, as it was in summer. 
 
 It is, of course, possible that the gas may first have entered the out- 
 house and penetrated from thence into the dwellmg house, but it seems 
 improbable, as there was no accumulation of gas noticed in it. 
 
 Biefel and Poleck give the following analyses of coal gas, before and after 
 passage through a layer of sandy-humus earth two metres thick (= 78-7 in.) : 
 
 Before After 
 passing through the 2 metres of earth 
 
 Carbonic oxide— CO 10-52 13-93 
 
 Carbon dioxide— COj .... 3-06 2-23 
 
 Heavy carburetted hydrogen — C.^H^ . . 4-66 0-69 
 
 Light carburetted hydrogen — CH^ . . 31-24 17-76 
 
 Hydrogen— H 49-44 47-13 
 
 Oxygen— 0-0 6-55 
 
 Nitrogen— N 1-Q 8 1171 
 
 myoo 100^ 
 
050 HYGIENE 
 
 IODINE 
 
 Dried sea-weed is collected iu piles on the shore and hurned, leaving an 
 impure ash known as kelp, which contains iodine. Suhsequently the iodine is 
 obtained pure by heating with sulpliuric acid and manganese dioxide and 
 afterwards subliming. It gives off a perceptible vapour at the ordinary tem- 
 perature. Considerable quantities of metallic compounds of iodine are found 
 in the preparation of nitrate of potassium from Chili nitrate. 
 
 In Germany iodine is chietiy got from the iodide by distillation with 
 concentrated sulphuric acid and nitrate of potassium. 
 
 Iodine acta as a caustic on the skin. The vapour when inhaled in any 
 quantity produces irritation of the respiratory passages, coryza, sneezuig, 
 frontal headache, and even temporary unconsciousness. Prolonged exposure 
 to its action causes a characteristic coryza, with exaggeration and persistence 
 of the symptoms which are observed in temporary attacks. 
 
 The distillation and subsequent sublimation of the iodine are the stages 
 at which the vapours are likely to be most dangerous, and the essential pre- 
 cautions are to have the vessels made thoroughly air-tight, so as to secure the 
 cooling and condensation of the iodine without escape of the vapour. When 
 the iodine is being removed from the receptacles it is also liable to affect the 
 workpeople. In addition to other precautions it is then necessary to be 
 careful about the local action of iodine on the skin, especially if this be broken. 
 "When sulphuric acid is added to the kelp, in the early stage of the manufac- 
 ture, large volumes of sulphuretted hydrogen are set free which should 
 be drawn into the chimney, if the process is carried on in a factory, and 
 not in the open air. 
 
 BEOMINE 
 
 Bromine is found as bromides in many mineral springs, in sea water, and 
 in the ash of marine animals and plants (kelp). The mother liquor obtained 
 by evaporation, or by treatment of kelp, &c., is distilled in stone vessels with 
 manganese dioxide and sulphuric acid. The bromine evolved is condensed 
 in a leaden or earthenware tube, and collected in bottles. 
 
 The impure bromine is purified by fractional distillation. It is kept 
 in bottles with well-ground stoppers, fixed with varnish, clay, and linen or 
 parchment paper. In consequence of its dangerous properties, and the 
 consequent expense of transport, bromide of iron is often used for transport 
 instead of bromine, for the preparation of the various salts in use, of which 
 enormous quantities are now used in medicine. 
 
 Bromine is a dark, reddish black, heavy liquid. It has a strong, 
 pecuUar, irritating smeU, and acts as a strong poison when inhaled. It 
 affects the workpeople very much like iodine. It causes irritation of the 
 mucous membrane, increased flow of saliva and tears, cough, malaise, giddi- 
 ness, spasm of the glottis, and asphyxia. Immediate removal from the place 
 and inhalation of aqueous vapour are recommended as the best remedies. 
 Free ventilation to prevent the accumulation of the poisonous vapours is very 
 important. 
 
 The most dangerous stages of the manufacture are when the stone 
 receptacles are bemg emptied. In the emptying of the vessels used for 
 rectifying the bromine, also, the workmen are much exposed to danger, 
 and must protect mouth and nose with cloths. Again, when the bromine is 
 being filled into the bottles for storage, it is absolutely necessary for the men 
 to protect their respiratory organs by the use of cloths, cotton wool, &c.- 
 
OFFENSIVE BUSINESSES 951 
 
 Sometimes a condition much resembling bronchial asthma occurs to work- 
 men, but specific chronic intoxication is unknown. 
 
 It is essential that only healthy workmen should be employed in this trade. 
 Those with any predisposition to pulmonary disease or to excess in drink should 
 be rigidly excluded. If this be done, and the precautions referred to observed, 
 the health of the workpeople seems not to be injuriously affected. 
 
 The passage of water containing bromine from the works into neighbour- 
 ing streams and water-supplies must be most carefully prevented ; the vege- 
 tation of the neighbourhood will certainly be destroyed if the vapours are 
 allowed to escape unchecked. 
 
 CIILORINE 
 
 The effects of chlorine and hypochlorous acid are somewhat similar to 
 those of iodine and bromine, and are frequently seen in workers where 
 chlorinated lime (' bleach ') is used, as in the manufacture of this compound, 
 bleach works, &c. 
 
 Chlorine when inhaled in a concentrated form causes spasm of the glottis ; 
 when more dilute, irritation of the bronchial passages, eyes, nose, and throat. 
 Men, however, soon became habituated to the inhalation of dilute chlorine, 
 though they suffer from dyspepsia and acidity of the stomach, and lose flesh 
 and become anfemic. Loss of smell is a common chlorine symptom among 
 workers in chlorine. 
 
 ARSENIC 
 
 This metal sometimes occurs free in nature, but is more commonly found 
 in combination as an alloy, especially with iron, cobalt, and nickel. It 
 is widely distributed, and is a not uncommon constituent of mineral springs. 
 
 It is generally recovered from its ores by roasting, or by being exposed to 
 a current of heated air in a reverberatory furnace, arsenious acid (AsjOg) being 
 formed. This is carried off as a vapour into long flues, where it is preci- 
 pitated as ' white arsenic,' or arsenious acid. 
 
 Metallic arsenic is little used, except in the manufacture of shot to 
 impart hardness. It also exists in ' white copper,' or ' new silver,' an aUoy 
 of copper and zinc. 
 
 The emptying of the flues or chambers in which the arsenious acid has 
 condensed is a very dangerous operation for the workmen. They are gene- 
 rally cased in leather, glazed eye-holes being left to enable them to see, the 
 mouth and nose being covered with damp cloth. 
 
 Combined with copper it constitutes the brilliant Scheele's green, and 
 another much used pigment, the Schweinfurth green, is a double salt of 
 arsenite and acetate of copper. These are the only metallic arsenites used 
 in the industries. They are found in wall papers, green water-colour paints, 
 oil paints, wafers, &c., and have caused fatal effects from being inadvertently 
 used to colour blanc-mange and confectionery. The makers of the arsenical 
 green wall paper, printers using green pigment, and occupants of rooms 
 papered with this deadly substance have suffered serious illness and even 
 died from its effects. It is also used in preparing anunal skins for stuffing. 
 Schweinfurth green is used for colouring carpets, artificial flowers, light 
 tarlatan for dresses, green paper lamp-shades, &c. The grinding of Schwein- 
 furth green is a most dangerous process, and yet it is very remarkable 
 that the men suffer so little, seeing that they are covered with the dust from 
 head to foot. 
 
 In the preparation of artificial flowers (leaves, buds, twigs, &c.) the greea 
 
952 HYGIENE 
 
 colour is obtained from the same source. The leaves are cut out of paper, 
 cloth, &c., which is usually dyed beforehand with a colour of the same cha- 
 racter, then they are usually varnished and the powdered Schweinfurth green 
 sprinkled on. This is a most dangerous operation, leading to inflammation 
 of the eyes, swelhng of the face, and ulceration of the hands. The use of 
 the dry powder should be entirely forbidden, and the colour should be used 
 only when mixed with collodion, turpentine, &c. 
 
 Arsenite of potassium is an important compound, as it is used for the 
 manufacture of Scheele's green, which is an arsenite of copper. It is pro- 
 duced by acting on a solution of sulphate of copper with arsenite of potassium, 
 or by dissolving in water arsenious acid or adding sulphate of copper, and 
 then precipitatiiig with an alkaline carbonate. 
 
 Ai'seniate of sodium is also of importance, because in its manufacture, as 
 in that of arsenic acid, abundant and highly dangerous nitrous vapours are 
 discharged. 
 
 Arsenic acid is largely used in various industries, especially in the manu- 
 facture of certain aniline colours such as magenta and rosaniline. Arseni- 
 ous acid has been found, and arsenic acid been found to the extent of 7 per 
 cent, in such colours. These brilhant colours are largely used to render 
 more attractive syrups, sweetmeats, Mqueurs, &c. It has been supposed that 
 the bad efl'ects sometimes attributed to the wearing of flannel, socks, &c., 
 dyed with aniline colours may really have been due to arsenic present in 
 some form. 
 
 Orpiment, or yellow tersulphide of arsenic, owes its dangerous properties 
 to the presence of arsenious acid. It is sometimes found native. It is the 
 chief ingredient in King's yellow, which is a mixture of orpiment and 
 arsenious acid. It is much used in paper-staining, painting, dyeing, and 
 colouring toys. It has been used (instead of lead chromate) to colour Bath 
 buns. It is also used in fellmongering, mixed with lime, in the removal of 
 wool from the hides. 
 
 Absorption of the poison may take place through a raw surface, and 
 even through the unwounded skin. It is not an accumulative poison, but is 
 ehminated by the urine, sweat, and bile. It causes paralysis of the heart, 
 but whether directly or indirectly is uncertain. 
 
 The conditions of chronic poisoning may ensue from one large dose, or 
 from repeated small doses. Gastric catarrh is the prominent symptom at first, 
 accompanied by the pecuhar feeling of burning in the fauces, dry tongue, 
 thirst, and sometimes superficial ulceration in the mouth. There is irri- 
 tation of the conjunctivae, with sufiusion of the eyes, and more or less 
 photophobia. The skin often exhibits a pecuhar vesicular eruption, called 
 eczema arsenicale, or the eruption may resemble the nettle-rash form of scar- 
 latinal rash. There may be well-marked nervous symptoms, even including 
 paralysis. 
 
 Notwithstanding these severe symptoms of general intoxication patients 
 have been known to recover completely, after two to three weeks, if placed 
 Tinder proper treatment. 
 
 It is absolutely necessary to remove from the influence of the poison 
 persons who show symptoms of being affected, and this whether they are 
 suffering from symptoms of general intoxication, or merely from skin or 
 other external affection. It is by no means certain that the skin affections 
 are not sometimes indicative of antecedent general affection, and not merely 
 a preliminary and localised result of the action of arsenic. 
 
 The personal hygiene of the workmen should be directed to the mainte- 
 nance of great personal cleanhness, avoidance of exposure of any wounded 
 
OFFENSIVE BUSINESSES 953 
 
 •surface of skin to the action of dust or vapour containing arsenic, avoidance 
 of taking any food or drink in the workrooms, regularly changing the work- 
 ing clothes before going home, shaving the face clean and keeping the hair 
 short to avoid accumulation of dust, &c. 
 
 The preventive hygiene consists partly in the provision of suitable con- 
 densing chambers, and especially their complete closure, and partly in efficient 
 ventilation. 
 
 Public hygiene demands the absolute prevention of any water containing 
 arsenic being discharged into sewers or streams. The chimneys should also 
 ■be of considerable height, and from time to time the vapours should be 
 ■examined to see that no arsenic is escaping. The insertion of numerous 
 projecting buttresses in the condensing flues is a successful method of in- 
 creasing their power of securing the maximum of condensation. 
 
 One of the most important of the measures of precaution is the employ- 
 ment of arsenical colours as little as possible, and it is greatly to be desired 
 that chemists would direct their attention to enabling this to be done suc- 
 -cessfully. There can be little doubt that all the advantages of the highly 
 dangerous arsenical greens could be obtained without their dangerous pro- 
 perties, if the question were seriously taken in hand and an effort made to 
 ;release the makers and men from the danger they involve. 
 
 CHKOMIUM 
 
 Although this metal is scantily distributed in nature, its compomids are 
 ; greatly used in certain industries, and have a great sanitary importance from 
 their dangerous action. The principal ore of chromium is chrome ironstone. 
 
 Its most important salts for iadustrial purposes are the bichromate 
 (K2Cr207), which is prepared by fusing a chromic compound with potassium 
 ■carbonate, when it becomes oxidised and a yellow soluble chromate is 
 formed. By the addition of sulphuric acid the bichromate is formed, in red 
 crystals. This salt is the great source of the valuable chrome pigments, and 
 is used by both the calico dyer and cahco printer to produce the chromates of 
 lead (chrome yellow and orange red). It is also used in mordanting wool and 
 in the dyeing of silk and linen. Chrome colours are also largely used in 
 glass and porcelain painting. 
 
 It is equally important to the dyer as a powerful oxidising agent, this 
 property being sometimes utihsed to develop colour, and sometimes, on the 
 contrary, to destroy it. 
 
 Chromates of barium, lead, and copper, and a dichromate of sodium, chrome 
 alum, chromium sulphate and acetate, and several other compounds, of 
 which the nitrate, sulphate and nitrate-acetate, and acetate are the most 
 important, are much used in calico-printing for steam-colours — e.g. browns, 
 blacks, olives, &c. 
 
 Poisoning from swallowing of bichromate of potash has occurred, the 
 principal symptoms resembling those of Asiatic cholera very closely : about 
 half a grain has been known to produce poisonous effects, with vomiting, 
 and profuse diarrhoea. The symptoms are not unlike those of poisoning with 
 arsenic or mercury. Sometimes, however, the nervous system alone seems 
 affected, and not the digestive tract. Poisoning has been caused by the 
 use of chromate of lead instead of turmeric for staining the skins of sausages. 
 
 Chrome yellow is frequently used to colour papers for wrapping bonbons 
 . in ; it is more likely to be dangerous in the form of paint in children's paint- 
 boxes, and has more than once caused death when employed to colour 
 : sweets in quantities so small as a fifth of a grain. 
 
054 HYGIENE 
 
 The action of the chromates and bichromate of potash on the skin and 
 nerves causes destructive ulcerative action on the skin and mucous membranes, 
 unfortunately too well known. It has been said that a, man who worked 
 at bichromate could be recognised at a glance by the deformity of his nose. 
 
 The pulverising of the chrome-u-on ore does not appear to produce the 
 almost specific injuries of chrome, and is offensive only as a dust, which, like 
 others, is injurious when constantly inhaled. 
 
 Danger arises when the chromates are being ground. The fine dust falls 
 on the skin and adheres to moist parts, which it irritates, acting with greatest 
 severity on the delicate mucous membrane of the nose, where the carelessness 
 of the workmen often leaves the dust undisturbed. There is often a quantity 
 of caustic alkali mixed with the chromate, which increases the effect of the 
 latter. The inhaled dust causes sneezing, and a thickish \Yatery or bloody 
 discharge from the nose. Ulcers form on the septum, and not inh-equently 
 end in perforation, which is most commonly preceded by the formation of 
 a scab. There is seldom any offensive odour from the ulcers. On the 
 skin also the vesicles or papules caused at first by the irritation may end 
 in ulcers having clean-cut edges, and appearing as if punched out. They 
 may extend over a large part of the body, and destroy the tissues to the bone 
 if neglected. It is said that snuff"- takers enjoy immunity from these effects. 
 The operation of pulverising the bichromate and other dangerous salts 
 should be done in a closed chamber, and should be effected by rollers. (Cf. 
 Sanitary Precautions, art. Lead, p. 9C4). 
 
 The chimney of the calcining ovens must be furnished with proper means 
 of drawing off" the dust and fumes into a suitable chamber, to prevent destruc- 
 tion of the vegetation around, and injury to men and animals. There is also 
 danger of ponds and rain water being poisoned. It is most important that 
 wash water, &c., which may contain bichromate, be not discharged into 
 streams or ponds used for drinking. So dangerous is this process that it 
 should not be tolerated in thickly populated neighbourhoods. 
 
 MEECUEY 
 
 This important article of commerce is found native in but small quan- 
 tities, and is chiefly met with as the sulphide or cinnabar (vermilion), some- 
 times calomel or subchloride. It is the only metal which is hquid at the ordi- 
 nary temperature, and is so volatile that it gives off vapour at all temperatures. 
 
 The metal may be extracted from the native cinnabar by burning off 
 the sulphur, or by heating the ore with some substance which will combine 
 with the sulphur, and form a fixed compound with it, thus aUowuig the mer- 
 cury to be separated by heat. The former method is practised at Almeida, but 
 owing to defective condensation is extravagant. The latter method is effected 
 by mixing the cinnabar with iron fihngs or slacked lime, and distilhng in re- 
 torts. The sulphur of the cinnabar combines with the iron or hme, and the 
 mercury is vaporised and condensed in receivers filled with water. 
 
 Mercury is used in great quantities in extracting gold and silver from 
 their ores by amalgamation, and these amalgams are largely used in silvering 
 and gilding. It is also used largely for silvering mirrors, for the preparation 
 of vermihon (ciimabarj, a most important and durable pigment; as well as 
 in the construction of philosophical instruments, and as a medicine. Cinnabar 
 is very largely used as a pigment. 
 
 The perchloride (corrosive sublimate, mercuric chloride, HgCl2) has come 
 into great use of recent years as a disinfectant. It exercises a most destructive 
 action on micro-organisms. A solution of 1 per 1,000 is sufficiently strong 
 
OFFENSIVE BUSINESSES 955 
 
 for almost any purpose of this kind. Mercurial poisoning has followed the 
 use of such solutions as this. 
 
 Mercurous chloride (calomel) is usually prepared by heating finely divided 
 metalhc mercury with corrosive sublimate. 
 
 Among the trades in which mercury or its preparations are used, and in 
 which danger arises to the workpeople, may be mentioned the following : — 
 
 Bronzing : not infrequently plaster objects are given a metallic appearance 
 by rubbing them with an amalgam consisting of equal parts of mercury, tin, 
 and bismuth, and subsequently varnishing them. Persons engaged at this 
 work not infrequently exhibit the symptoms of mercurial poisoning in a very 
 intense degree. 
 
 Hat-maldng is a trade of a still more dangerous character. In the pre- 
 paration of the skins it is a common practice to rub them with a coarse brush, 
 wet with a 10 to 11 per cent, solution of acid nitrate of mercury in nitric acid. 
 
 In the subsequent operations of depilation and shaking the skins, clouds 
 of mercurial dust, as well as that of arsenic, are spread about, to the great 
 danger of the workpeople, among whom poisoning with both these metals is 
 common. 
 
 Gilding by the aid of mercurial gold amalgam is also a dangerous occupa- 
 tion, the workpeople being liable to intoxication at various stages, chiefly in 
 the preparation of the amalgam, and in its application to the objects to be gilded. 
 Mercurial vapours are developed in the bath, and also when the mercury is 
 volatilised at the moment of applying the gilding ; further, the continued 
 handling of the mercurial amalgam itself leads to cutaneous absorption and 
 intoxication. 
 
 The emaciated, unhealthy appearance of the workmen too commonly 
 indicates the nature of their occupation. Closer examination shows their 
 irritated gums, often toothless, and the existence of skin irritation, dyspnoea, 
 and other disorders arising from exposure, not only to the dangerous action 
 of mercury, but also to the nitrous fumes, which are so disastrous to those 
 engaged in this trade. 
 
 Artificial flower-makers are exposed not only to dangers from the use of 
 poisonous arsenical and lead colours, but are obliged also to use the no less 
 dangerous mercurial pigments, chiefly the sulphide, chromate, and biniodide 
 (brilliant scarlet). 
 
 The operations of preserving and stuffing the skins of animals is dangerous 
 to those employed, from the fact that arsenic (generally in the form of 
 soap) and corrosive sublimate are largely employed by them. It is not merely 
 at the times when the preservative materials are employed that the danger 
 exists, but long afterwards ; when these materials have become desiccated 
 they are converted into dust, which permeates the atmosphere of the rooms 
 where the stuffed animals are kept, and may cause aU the symptoms of 
 arsenical or mercurial poisoning. 
 
 Photographers, who employ the bichloride, are also Kable to absorption of 
 the poison, especially if there should be any fissures or wounds on the hands. 
 The large amount of mercury employed in telegraph offices, where the wire 
 connections are often made by means of cups filled with mercury ; the enor- 
 mous area of zinc plates which have to be kept amalgamated with mercury 
 at large telegraph stations ; the risks connected with the preparation of 
 barometers and thermometers, from which the boiling mercury sometimes 
 escapes, suggest important points for sanitary supervision. 
 
 The liability to mercurial poisoning is all the greater, as it is a metal which 
 can undoubtedly be absorbed through the unbroken sMn. This fact is fami- 
 liar from the readiness with which toxic effects are produced by inunction of 
 
956 HYGIENE 
 
 mercurial ointment in medical practice. It may also be absorbed through 
 the lungs, whether it enter in the form of vapour or dust, as well as fi-om 
 the digestive tract. 
 
 The absorbed mercury probably exists chemically combined chiefly with 
 albumen ; but, as it may be excreted with urine free from albumen, it is 
 manifest that the albuminous compounds may again undergo decomposition. 
 Mercury is excreted not only by the Iddneys, but also in the bile, milk, fsces, 
 and probably in the sweat. 
 
 It is remarkable that mercury may exist in a latent form in the body, and 
 under favourable conditions become active and produce serious symptoms in 
 persons who had for years been apparently free from its influence. 
 
 The predisposition to mercurialism varies greatly in diflerent persons, of 
 which Alfinger observed an illustration in the case of the sister of a woman 
 engaged in ' silvering ' mirrors, who, although she had never been in the 
 factory, became afi'ected with mercurial stomatitis through contact with her 
 sister, who was engaged in the mercurial work, but who was not herself in 
 any way troubled. The injurious eflects are usually observed withm a few 
 weeks or months after exposure, while some persons will escape for months, 
 or even years. 
 
 The earliest symptoms are nearly always increased secretion of saliva 
 and irritation of the mucous membrane of the mouth, accompanied soon by 
 a peculiar metalhc taste. Inflammation of the gums soon follows : they 
 become, swollen, tender and disposed to bleed, and the breath becomes most 
 offensive. The morbid condition soon spreads over the cheeks, lips, and 
 tongue, and they become covered with a greyish, croup-like membrane. At 
 points where the teeth press, ulcers are commonly observed, which may extend 
 in depth and area, and lead to extensive destruction of tissue. The general 
 nealth is always involved at this stage, and there are fever and restlessness, 
 with gastric and intestinal derangement. In some cases the nervous phe- 
 nomena precede and are much more serious than the local. The patient 
 suffers from great anxiety, the least thing unnerves him, and he may have 
 hallucinations. He cannot eat, suffers from considerable salivation, and 
 loses flesh rapidly. 
 
 The gravity of these cases often leads to long iUness, lasting four to six 
 weeks, and may even lead to chronic mercurialism lasting for years ; but 
 they seldom end fatally. The inflammation of the mouth, where the general 
 health has not suffered much, is usually subdued in a few days. 
 
 If these symptoms be disregarded, and the patient be not at once removed 
 from exposm-e and put under proper treatment, there are superadded other 
 more serious troubles. There comes on gradually a trembling of the muscles, 
 commonly known as ' the trembles ' (mercurial tremor), affecting gradually a 
 larger and larger area of the voluntary muscles, until finally the patient 
 may be deprived, not only of the power of locomotion, but his speech becomes 
 stammering and hesitating (psellismus mercurialis), and he may be quite 
 unable to feed himself. The ' trembles ' commence usually in the face and 
 tongue, and gradually extend to the arms and legs. At first the muscles 
 are only affected temporarily, mostly during movement or under emotion, and 
 the tremor may cease entirely during sleep. Eeflex action and power over the 
 sphincters and electrical irritabihty continue unimpaired. These symptoms 
 may progress and be rendered more serious by the occurrence of mental de- 
 rangement, which sometimes takes the form of maniacal excitement, but 
 more usually of hypochondria. 
 
 The prognosis is in general favourable, but sometimes the tremor is never 
 lost. 
 
OFFENSIVE BUSINESSES 957 
 
 Complete removal from risk of further absorption, good food and air com- 
 bined with ferruginous tonics, are the best treament. Chlorate of potash is 
 very useful for the stomatitis. Small doses of iodide of potash no doubt in- 
 crease elimination. Large doses have been known to increase the severity of 
 the symptoms, apparently by setting free mercury fixed in the tissues, and 
 thus leading to its entrance into the blood and nervous tissues. 
 
 Sanitary Precautions. — In this as in other dangerous trades it is above 
 all things important to instruct the workmen thoroughly in the nature of 
 the risks they have to incur, and the means of avoiding them. The protec- 
 tion of the workman from the local and general affections arising from the 
 absorption of mercury into the body, or from its local action, requires a 
 combination of precautions on the part of the manufacturer in the construction 
 and maintenance of his works, and on the part of the workman in seeing 
 that the various means provided for protecting him are kept in good working 
 order, as well as in taking great care to supplement these precautions by 
 attention to personal hygiene. 
 
 In the removal of the contents of the condensing chambers and flues the 
 greatest care is required, and these must be constructed so as to prevent the 
 escape of fumes or gases. The men should be provided with long overalls 
 accurately fitting at the neck and wrists, so as to keep the skin as well pro- 
 tected as possible, and the hair of the head and face should be kept close cut, 
 and a cap of paper or other smooth material always worn, to prevent deposi- 
 tion of dust in them, A good mask would be a great boon, but is still a deside- 
 ratum. The clothes used in the works should not be worn at home, but left 
 at the workshop. Great cleanliness should be maintained by frequent wash- 
 ing, especially of the hands, face, and mouth ; and. means for this should be 
 conveniently placed for the workmen, as well as warm baths, in which their 
 whole body can be thoroughly freed from the noxious materials. The 
 chambers where mirrors are ' silvered ' require to be well ventilated, and 
 the ventilation should be downwards, as the vapours are heavy and rise but 
 slowly from the m.ercury bath, and all the workrooms must be freed from 
 deposits of dust at very short intervals. In spreading the mercury on the 
 glass it is most important that the hand be not directly placed in the metal ; 
 the flannel with which the spreading is usually done should be held by a 
 rod, so as to keep the workman as far as possible from the fumes. The 
 mercury should be kept in covered vessels as much as possible, to prevent 
 the diffusion of the vapour which it gives off at all ordinary temperatures, 
 and still more in hot workshops. All cloths, &c., after use should be re- 
 moved as rapidly as possible from the workshop, to avoid exhalation from 
 them. 
 
 There is one other means of general and great importance for purifying 
 the air of the rooms, viz. the diffusion of the vapours of ammonia throughout 
 them. This cannot be properly done while the men are in the workshops, but 
 at night when they have left it should be done freely. The very best results 
 are said to have been obtained from this practice, which has long been in 
 operation ; but the rationale of it is not apparent, as metalUc mercury does 
 not combine with ammonia. In the works at Chauny this process has been 
 employed for over twenty years with the best effects, as is alleged. 
 
 As there is always danger from the mercury which gets spilled on the floor 
 during the various processes in which it is used, the floors should be made of 
 good asphalte to prevent its absorption ; and by keeping the floor wet the 
 mercury is rendered more easily visible. By giving the floor an incline, and 
 having gutters constructed, the collection of the mercury is greatly facilitated. 
 It will also be found a great advantage to have in the workshops, on the floors 
 
958 HYGIENE 
 
 and elsewhere, quantities of tinfoil, or other metal which readily forms an 
 amalgam with mercury, as then the danger will he mitigated, and pecimiary 
 loss by waste of the metal greatly diminished. 
 
 LEAD 
 
 This metal is a most important article of commerce, and is used in a 
 great variety of industries. The specific and peculiar character of the 
 symptoms produced by intoxication with lead, and the fatal results which 
 sometimes follow, combined with the epidemic occurrences of lead-poison- 
 ing from drinking water, have attracted a great deal of attention to the sub- 
 ject, and still there is much which is mysterious and quite unknown in con- 
 nection with the familiar diseased condition arising from absorption of lead. 
 
 It may be introduced into the system either by direct absorption through 
 the skin or mucous membranes, or by the inhalation of the vapoiu* or powder 
 of lead or its compounds, which, produced in certain stages of its manufacture, 
 or by the extraordinary variety of uses to which compounds of lead are 
 put, account for the frequently surprising and apparently unaccountable 
 occurrences of symptoms of plumbism under circumstances which at first 
 sight would seem to exclude the possibility of such. 
 
 Among the workmen who are most exposed to the danger of lead-poisoning 
 may be mentioned, besides the lead workers proper, the following : painters, 
 gilders, file-cutters, type and note founders, calico printers, colour grinders, 
 glass grmders, bronzers, enamellers, &c. 
 
 The industries in which lead is used are too numerous to mention. 
 Architects and builders use it for gutters, roofs, windows, &c. ; it is used 
 for gas and water pipes ; in chemical works for linings for sulphuric acid 
 chambers, pans, and cisterns ; tea-chests are lined with it ; in combination 
 with tin, bismuth, and antimony, it forms soft solder ; while white metal and 
 brass both contain it ; printer's type, stereotype metal, organ pipes, and a host 
 of other articles are formed of material containing lead. 
 
 Chemical compounds of the metal are used as colouring agents, white, 
 red, and yellow lead being enormously used ; white paint and white papers 
 most commonly have lead for the foundation of the colour. 
 
 Carbonate of lead, or white lead, is very extensively used as a paint, and 
 is manufactured on an immense scale. It is prepared by various processes : 
 (1) By the Dutch method it is obtained through the action of a weak solution 
 of vinegar on coils of thin sheet-lead. The grinding of this carbonate, 
 even when done under water, is very dangerous to the workmen. (2) By 
 Thenard's method it is developed directly by the action of a current of CO2 
 on the lead. (3) The CO2 given off in the combustion of coke has been 
 employed at Birmingham for the same purpose. The carbonate should always 
 be sent out as a moist substance. 
 
 White lead, or carbonate of lead, PbCOg, so largely used as a pigment, is 
 still mostly made by the old and dangerous Dutch process, which may be 
 thus briefly described. On the tops of small earthenware pots, containing 
 acetic acid, thin sheet-lead is placed, and the pots are ranged in layers of tan, 
 which by its oxidation maintains sufficient heat to keep the pots at a mode- 
 rately warm temperature. A layer of wooden planks is placed over the 
 whole ; then another layer of pots, and so on in successive layers till a 
 'stack' of 'blue beds' is formed. No special danger is incurred in the 
 stacking of a blue bed. The acetic acid is slowly volatilised by the heat 
 evolved by the oxidising tan ; the lead is oxidised, combining with the acid 
 to form subacetate of lead, which is again decomposed by the carbon dioxide 
 
OFFENSIVE BUSINESSES 959 
 
 ■evolved from the tfin, subcarbonate of lead (carbonate of lead or white 
 lead) being formed ; and in this way the whole of the lead is gradually 
 converted into a crust of white lead. The stack is then, after the lapse of 
 about three months, converted into a stack of ' white beds ' — i.e. of white 
 lead. When the conversion is complete, girls enter the stack, place the 
 white lead in trays, and carry those chiefly on their heads, first to rolling mills, 
 where the crust is removed from any undecomposed lead, and subsequently 
 to heated drying stoves, kept at a temperature of about 200° F. After being 
 dried, the white lead is ground, washed, and then dried as a fine powder. 
 The commercial value of the product greatly depends upon its minute state 
 of division, white lead being one of the most minutely divided of known 
 mineral substances. This minuteness of its particles greatly favours the dis- 
 semination of white lead as dust through the atmospliere, and aids its absorp- 
 tion when it comes in contact with any absorbing surface of the body. It is 
 the women engaged in removing the white beds, and in the stovhig, grinding, 
 and packing operations who are the greatest, though by no means the only, 
 sufferers from plumbism. 
 
 The effects of working in white-lead factories are insidious, though in the 
 ■end severe, and not infrequently fatal. They are collectively the now well- 
 recognised symptoms of plumbism or saturnine poisoning : colic, constipa- 
 tion, irregular and profuse menstruation, wrist-drop, and other forms of 
 paralysis ; pains in the joints, often termed 'rheumatics,' cachexia ; degene- 
 ration of the liver and kidneys ; and by no means unfrequently epileptiform 
 convulsions, ending in coma, precede a fatal termination of the disease. 
 Throughout there usually is the well-known and characteristic blue line of 
 lead-poisoning along the free margin of the gums, due to a deposit of sulphide 
 of lead. 
 
 The varnishing of leather is commonly effected by the use of red and 
 white lead ; what is termed ' glace ' leather for gloves and the beautiful glaze 
 •of visiting and playing cards contain the same deadly ingredient. 
 
 The beautiful lustrous leaves and flowers which represent the sparkling 
 ■dew are poisoned with lead, and some of the most lovely artificial flowers are 
 dyed with it (the white with carbonate of lead, the red with red lead, the 
 yellow with chromate of lead). 
 
 Artificial jewels mostly contain the same ingredient and are pre- 
 pared with great danger to the workpeople ; and the glaze of the commoner 
 saucepans also contains it. A poisonous varnish containing litharge is used 
 by gilders of wood. 
 
 Dressmakers have been poisoned by using silk weighted with acetate 
 of lead (sugar of lead), through moistening the ends to facilitate threading 
 their needles ; and tailors have had the same fate from the lead employed in 
 dyeing the alpaca they were working on. Even the preparations of lace 
 and straw hats are commonly associated with this agent. Painters are 
 notorious sufferers, several of their colours containing lead, and white paint 
 containing little else than the carbonate. 
 
 Acetate of lead, or sugar of lead, sometimes particularised as 'white,' is 
 prepared by dissolving litharge in acetic acid, and evaporating to crystallisa- 
 tion. The name sugar of lead is no doubt due to its appearance and sweet 
 taste. There is a ' brown sugar of lead,' also prepared in a similar way by 
 the substitution of crude acetic or pyroligneous acid for the purer acetic 
 acid. This salt is used in dyeing and printing, and formerly (not so much 
 now) for weighting silk. In dyeing it is largely used for producing chrome 
 yellow and chrome orange, and also in the manufacture of the acetates of 
 aluminium, iron, and chromium. It is also used in making hair-dyes. 
 
960 HYGIENE 
 
 Nitrate of lead is prepared by dissohdng litharge in hot dilute nitric^ 
 acid. Both the acetate and the nitrate are used in cahco-printing and 
 cotton-dyeing for the production of orange and yellow colours. In the latter 
 operation, after the cotton has been printed or impregnated with a solution 
 of the lead salt, it is passed through a solution of bichromate of potash. 
 In calico-printing the lead may be fixed as sulphate by means of sulphate of 
 soda, Li these cases the lead acts as a mordant, the colouring matter being 
 the chromic acid or bichromate of potash. 
 
 Sulphide of lead, or galena, occurs in nature, and is used mainly for 
 glazing pottery, bricks, &c. Not only the producers of these articles, but 
 the users of them, may be infected by the presence of lead in the glaze. 
 
 Lead is readily acted on by air, the brilliant metallic lustre left on section 
 becommg tarnished by formation of a thin fihu of oxide on the surface. Air 
 contained in water also acts powerfully on lead, while Avater deprived of air 
 will not tarnish lead placed in it, for an immensely long time. When lead 
 is placed in well-aerated water, the film of oxide formed on its surface is 
 quicldy dissolved by the water. 
 
 Shot is made from molten lead, which is allowed to fall a considerable 
 height (in so-called shot-towers) mto water. It is, however, not pure lead 
 which hardens it, but an alloy of lead and arsenic, the proportion of arsenic 
 being about three to seven per 1,000. 
 
 Notwithstanding the numerous opportunities presented of seeing lead- 
 poisoning, the exact nature of the disease is still far from being thoroughly 
 understood. That a general cachectic condition exists in persons long sub- 
 jected to the action of the poison is clear ; but there is a great difference of 
 opinion as to whether the blood, or some special organ, is chiefly affected. 
 Henle considers that absorbed lead acts mainly on unstriped muscular fibre, 
 while the more common view perhaps is that the nervous system is the 
 special seat of attack. 
 
 The danger of mfection among workmen much exposed to the inhalation 
 of the fumes of the metal, or to dust which contains it, or to absorption 
 through the skin or digestive tract, is very great. When the symptoms 
 appear they are found to be, although multiform, still distinctly uniform, so 
 iax as each group is concerned, and characteristic. Even before decided symp- 
 toms show themselves, the patient, by his ' facies ' and general condition, 
 betrays the approachuig outbreak of disease. This prehminary condition may 
 last a considerable time. There is usually loss of flesh and loss of strength 
 and weight ; the face, and even the whole skin, assumes a peculiar yellowish- 
 grey colour (not unlike that of long-term prisoners), the breath becomes un- 
 pleasant to smell, there is a pecuhar dry sweetish flavour in the mouth, and 
 the very characteristic blueish-grey line appears on the gums. 
 
 The blue lead-line on the gums may exist, the whole gums being even 
 black for years, without any symptom of lead-poisoning, and it may be- 
 absent when the symptoms are well marked. It is probably much more fre- 
 quently a local deposit than a result of elimination of lead from the system. 
 Microscopic examination of the parts shows black granules, situated some 
 inside and some outside the capillaries, and probably consisting of insoluble 
 sulphide of lead. The sulphur is supplied probably from decaying organic 
 remains of the food deposited between the teeth, &c. 
 
 It is most commonly the abdominal organs which first exhibit decided 
 symptoms of the disease. After a gradually increasing condition of constipa- 
 tion, the patient begms to complain of more malaise than is usually attributed to 
 that cause, with a feehng of tightness in the belly, which is hard and retracted. 
 This sensation becomes usually a more or less severe colicky pain situated 
 
OFFENSIVE BUSINESSES 961 
 
 about the umbilictis, and radiating chiefly downwards, and having the pecu- 
 liarity of being reheved by pressure. The stomach is disordered, and vomiting 
 frequently occurs. The pains extend to the joints and muscles, and the latter 
 may exhibit already at this stage symptoms of paralysis, and the urine and 
 salivary secretions are both scanty. 
 
 The remarkably slow pulse, with proportionately increased frequency of 
 the respiration, have been dwelt on as almost pathognomonic ; thirty con- 
 tractions of the heart per minute with forty and more inspirations being com- 
 mon enough. 
 
 Where the patient is obliged to continue exposed to the accumulative- 
 action of the poison, convulsions and paralysis, the latter as a common occur- 
 rence, ensue. The muscles attacked are usually those of the upper extremi- 
 ties, and more particularly the extensors of one or both arms. The supinator 
 longus and the deltoid are apparently very rarely attacked. The sensibility 
 of the affected parts is generally left unimpaired. Along with power of 
 contractility the muscles are found to have lost their electrical irritabihty, 
 and gradually become wasted and atrophied. As a rule, the paralysis is 
 limited to the muscles supplied by the musculospiral nerve, especially those 
 supplied by its posterior interosseous branch. 
 
 The legs are sometimes attacked, and, curiously enough, it is the homo- 
 logous muscles to those in the arm, the extensors of the leg and foot, which 
 are mostly affected. 
 
 The appearance of the hands in paralysis is peculiar and characteristic,. 
 and is well expressed by the popular term ' drop -wrist ' — ' main en griff e.' 
 
 Secondary misshapements and even dislocations may occur, and mask 
 the simple and characteristic appearances usually seen. 
 
 More serious consequences still may arise in the shape of pronounced 
 brain symptoms (encephalopathia saturnina), causing usually considerable 
 loss of sensation ; there may be even complete hemianesthesia, without much 
 loss of motor power. Delirium, convulsions, and coma may also occur. 
 Abortion is sometimes produced in severe cases. Dr. Eayner reports that 
 the proportion of painters, plumbers, and glaziers among his insane patients 
 w^as nearly one-third more than among the general population.^ 
 
 It will be seen that the severity of the disease is sufficient to demand the- 
 most careful means for its prevention. The attacks may be fatal, or may, 
 while yielding to treatment, leave permanent ill-health, and more or less- 
 deformity and paralysis behind. 
 
 From the great variety of uses to which lead in one form or another is 
 put, it will not be surprising that lead-poisoning is found occurrmg under 
 most various conditions and where least suspected. At one time it was so 
 prevalent in Poitou, owing to its addition to inferior wines, that it was termed 
 the Mai de Poitou ; it was very common once in Devonshire, owing to the 
 ■use of lead in the vessels used for cider-making ; and the leaden ' worms ' 
 used in the distillation of rum in the West Indies caused it to be prevalent 
 there. 
 
 It occurs among cabinet-makers from the use of glass-paper, the lead in. 
 the fine glass dust becoming dissolved in the sweat of the hand and absorbed^ 
 and the dust being also inhaled. A liquid containing as much as 45 per cent. 
 of lead is also used for colouring wood, and has been known to cause 
 poisoning. 
 
 The glaze of tiles, bricks, and pots has also produced poisoning, generally 
 consisting as it does of a large proportion of sulphate of lead, as much as 
 equal parts of this salt and ground sand being sometimes used. In this case, 
 ' Journal of Mental Science, No. CXIV., New Series, No. 78, p. 223. 
 
 VOL. I. 3 Q 
 
962 HYGIENE 
 
 too, there is danger from the inhalation of the dust arising in the grinding 
 process as well as fi-om the fumes produced during the baking. 
 
 The makers of pottery and faience are exposed to great dangers through 
 the poisonous enamels they use. One brown enamel contains 52 per cent, of 
 red lead, and a white one 2 parts of red lead, with 4-4 parts of calcine (which 
 itself contains 77 per cent, of lead). 
 
 The dangers chiefly arise during (1) the powdering of these ingredients 
 (inhalation and cuticular ab>;orption), (2) while the workmen are dipping the 
 vessels in the water to which the powders have been added (cuticular absorp- 
 tion), (3) when they are being burned (inhalation of fumes, and absorption 
 through skin), (-1) during a process sometimes employed of dusting the 
 vessels with powdered red lead. 
 
 Every form of enamel contains lead, chiefly as oxide, combined with more 
 or less ground flint ; a white enamel contains 50 per cent, white lead. 
 
 In jewellers' workshops, in order to recover every particle of the precious 
 metals, the sweepings are collected, and after the formation of an amalgam 
 with the ash, an alloy of lead is made, the mercury being driven off. In this 
 process lead-poisoning may occur. 
 
 Among the other more important trades in which danger from lead- 
 poisoning is liable to arise, omitting the manufacture of the various lead 
 compounds already named, the following deserve attention: 
 
 1, File- cutting. The plain bar of soft iron which is to be made into a 
 file is placed on a flat piece of lead, as a substance to which it will adhere 
 slightly without slipping, and which from its softness does not cause much jar- 
 ring when struck. The teeth of the file are cut by a sort of blunt chisel, held 
 in one hand, which is struck with a hammer held in the other. Some fifty ox- 
 sixty such strokes or more will be given in a minute, and each stroke cuts a 
 tooth in the file. It is evident that the hands of the file-cutter are almost 
 constantly in contact with the leadeii bed of the file ; and more important, 
 perhaps, when one side has been cut, and this rough side is turned down on 
 the lead, there is a good deal of rubbing away of the lead by the teeth of 
 the file. 
 
 All the larger files are cut by men, while of the small ones a large num- 
 ber are cut by women. 
 
 The cutters' hands are invariably covered with dirt, and under the nails 
 there is a considerable quantity collected, in which metallic particles, both of 
 iron and lead, can readily be detected by a magnifying glass or even by the 
 unaided eye. The rough benches or tables at which they work also show 
 dust in considerable quantities, of which a large part is lead. 
 
 The sweat of the hands, &c., undoubtedly oxidises and dissolves the lead, 
 and absorption then readily takes place. 
 
 2. The glass-cutter, who executes his often highly artistic work with the 
 simplest apparatus, sits or stands in front of a revolving grindstone, usually 
 some 8 to 10 inches in diameter, and of various thiclmesses (from about 1 inch 
 to 2-3 inches usually). The lower part of the stone is within a trough, into 
 which the water constantly supplied from above falls, as well as the fine 
 particles ground off the glass. The article to be ' cut ' is held against the 
 stone, which does not revolve very rapidly, until the glass is sufficiently ' cut ' 
 (really rubbed away), when its position is altered, and the ' cutting ' is con- 
 tinued on another part. 
 
 The source of lead-poisoning here is the large quantity of fine glass 
 powder with which the wet hands are continually in contact, the glass con- 
 taining lead. In connection with this, reference may be made to the occur- 
 rence of lead-poisoning among wood-polishers, due to the action of the 
 ■' sand ' paper, really made with ground glass, already mentioned. 
 
OFFENSIVE BUSINESSES 9G3 
 
 3. Type-founders and type-setters, with whom may be classed the setters 
 'Of musical type. Type-metal is an alloy of lead, tin, and antimony. 
 
 Type-setters are exposed to absorption of lead from constantly handling 
 this compound, and also from a common habit of holding type in the mouth 
 while at work. Further, there is often a good deal of dust about in the 
 type boxes and elsewhere derived from the type itself. Slight scratches on 
 the hands favour the impregnation of the system with the metal so abun- 
 dantly present. 
 
 4. The connection of weaving with lead-poisoning will appear very remote 
 at first sight. But a knowledge of the construction of the Jacquard loom 
 will show that with certain arrangements, which are common in some parts 
 of the country, there is considerable risk. The long cords, known as ' harness 
 cords,' in that form of the loom are kept taut by weights suspended at the 
 end termed ' lingoes.' A small loom will have as many as 1,200 to 1,-500 such 
 lingoes and cords, a large one 5,000 to 6,000. The lingoes are rod-shaped 
 weights about six to seven inches long when made of lead, and twelve to 
 fourteen inches long when made of iron. About twenty of them make one 
 pound in weight. As they hang from the harness cords they are almost all 
 in contact, and in the process of weaving some of them are rising and falling 
 almost continually. But there is also a good deal of oscillatory motion im- 
 parted to them through the shaking of the loom, especially in hand-looms. 
 The waste caused by this friction and clashing is very considerable, and in 
 four to five years, with hard work, a whole set of lingoes may be so worn away 
 as to be too light for use. They are not rubbed away uniformly by attrition, 
 but are worn in little notches, evidently due to striking against each other 
 rather than to uniform friction. They will lose in this way some 30 to 40 per 
 cent, in weight in four to five years. Taking the average weight of twenty 
 lingoes to one pound, this would give 300 lbs. of lead to 6,000 lingoes, the 
 loss of which, at 33 per cent., would give 100 lbs. of lead rubbed off in fine 
 particles on an average during four to five years, or, say, over 20 lbs. per 
 annum, and this from one loom only in a room. The amount of such 
 dangerous material given off from some scores of looms in a weaving shed 
 would therefore be a very serious matter, and cause grave danger of lead- 
 poisoning to the workpeople. 
 
 It is not only unnecessary to use lead for lingoes, but it is much more 
 expensive, and iron ones are also to be preferred, as they keep their shape and 
 position better. The motion of the lingoes can also be considerably diminished 
 by placing them all in a light framework. The use of leaden lingoes is 
 happily going much out of use in some parts of the country, and iron ones 
 are deservedly growing in favour. 
 
 In the manufacture of coloured wall-papers there are certain processes 
 fraught with grave danger to the workmen from the nature of the materials 
 employed, greatly increased by the mode of their employment in the produc- 
 tion of certain effects. 
 
 "Where a fine white ground is required, this is often produced by laying 
 ■on white lead ; minium is employed to produce red, and yellow is often pro- 
 duced by using other compounds of lead — viz. litharge, chromate, iodide, or 
 the chloride which, combined with the oxide, is known as Cassel yellow. 
 
 The ' satining ' of white paper consists in producing a fine lustrous coat, 
 chiefly effected by friction of the coating of white lead. In this operation a 
 great quantity of fine dust is produced, which is inhaled, swallowed, or 
 becomes deposited on the skin. The danger of lead-poisoning is therefore 
 Tery great. 
 
 ' Velvet ' paper, which has a diill rough surface, is produced by covering 
 
 3q2 
 
964 HYGIENE 
 
 tlie surface of tlie paper with an adhesive coating (starch, &c.), which is 
 powdered with cloth, reduced to fine dust, and coloured vnth. red lead, arsenical 
 green, &c. It is easy to see what injurious effects may be produced during 
 the production of this material. 
 
 Eulenberg mentions the polishing of garnets, as carried out in Hungary 
 by means of revolving leaden discs, as resulting frequently in lead-poisoning. 
 
 Lead intoxicatioi has also been traced to the use of leaden pipes, &c., in 
 beer macliines ; to the use of syphons having leaden or badly-made white- 
 metal fixtures, &c. 
 
 The , extensive spread of lead-poisoning by means of drinking water 
 affected by the leaden connecting pipes is familiar to all mechcal men. 
 
 Sanitary Precautions. — The mining operations are not, as a rule, calcu- 
 lated to induce any special danger of lead-poisoning, but there may be great 
 harm done by allowmg the water which is used in great quantities for wash- 
 ing the finer, broken ore, &c., to make its way into streams, ponds, &c. 
 
 During the smelting there is always more or less vaporised lead given off 
 along with sulphur dioxide, &c., and with these vapours there is invariably 
 present PbS, PbS04, PbCOg, &c. Therefore, smelting always necessitates the 
 employment of condensing chambers or other methods for preventing the 
 escape of these vapours into the atmosphere, which can only occur with great 
 detriment to neighbouring inhabitants and vegetation. In some lead works in 
 this country, long flues, sometimes having accessory catch-chambers, &c., are 
 constructed rising up the sides of hills, reaching to several miles in length, 
 Avhich act as condensers, and as much as five to six hundred tons of metal have 
 been recovered by this simple means in a year at one manufactory. The 
 collection and removal of this valuable harvest, won by very simple means for 
 the owner, requires great precautions on the part of the workmen, and should 
 above all things never be attempted until the whole of the parts are perfectly 
 cooled. Besides lea.d, the flues may contain other products directly derived 
 from the ore, or compounds produced during the smelting ; e.g., arsenic, zinc, 
 carbonate and sulphate of lead, thallium, tellurium, molybdate of lead, &c. 
 
 The condensation can be greatly facilitated, and danger avoided, by the 
 assistance of water, which may be applied cold in the form of a rain or shower- 
 bath, or as steam. By this means the fumes are thoroughly mixed with the 
 watery vapour and the most satisfactory results are obtained. 
 
 In the manufacture of red lead there is a large amount of dust produced, 
 of which only too palpable evidence can generally be obtained on entering 
 the premises. The escape of dust or vapour from the furnaces should be 
 most carefully avoided, as not only is there direct danger from the metallic 
 dust, but it gradually becomes oxidised, and soluble salts are formed, with 
 greatly increased danger to animal and vegetable life. 
 
 The grinding of the minium is also attended with danger, and should be 
 carried out in a closed chamber, provided with well-fitting glass windows to 
 allow of observation of the progress of the work. Subsequently the powdered 
 minium has to be filled into boxes or barrels, an unavoidably dusty operation, 
 during which the workmen should be protected by sponges or cotton-wool tied 
 before the mouth and nose. The joints of the cases should be carefully closed 
 by pasting with paper, &c. 
 
 The manufacture of white lead is much more dangerous when carried 
 out by some processes than by others. The ' Dutch method,' already de- 
 scribed, leads to the worst results — mainly from the destructive action of the 
 acetate, which causes the skin to crack and leaves raw surfaces for the 
 direct absorption of the poison. The wearing of gloves would afford protection 
 in this process ; and hberal inunction of the skin of the hands and face 
 
OFFENSIVE BUSINESSES 965 
 
 is of great service. The conveyance of the salts, after collection from the 
 surface of the lead spirals, should be effected with care, and if possible by the 
 aid of shoots, well covered. But the grinding is the most dangerous part of 
 the work. This should never be done, as is only too often allowed, with an 
 ordinary hammer or pounder. The least dangerous method is pulverising by 
 rollers, which can be so adapted as to discharge the broken-up material of any 
 desired degree of fineness. The whole apparatus should be covered in com- 
 pletely, so as to prevent, as far as possible, the escape of the deadly dust ; 
 and an exhauster should be applied to supply fresh air, and draw off the dust 
 into a special chamber, water bath, or other receptacle. For the great 
 majority of purposes for which white lead is required, it would be quite as 
 serviceable in the paste form, made up with oil, and prepared in this form 
 it would be deprived of most of its dangers. In order to grind it up with oil, 
 it is not necessary to dry the wet powder, as the water is forced thoroughly 
 out of the powder. Thus several dangerous operations are completely avoided. 
 
 With regard to the personal hygiene of the workmen, there is a great 
 deal to be effected by means which are simple and involve no hardships 
 or difficulties whatever. 
 
 Above all, personal cleanliness is important, nay essential. If a workman 
 who is all day in the midst of a very dangerous dust, which attaches itself to 
 his hair, beard, skin, and clothes, enters his mouth and nose and ears, gets 
 beneath his clothes and adheres to his skin, will not keep his body and clothes 
 clean, then it is hopeless to try to afford him protection by any means to be 
 devised. His hands and mouth are sure, after a few hours, to be fouled with 
 lead dust ; he should therefore rinse his mouth thoroughly from time to time, 
 and wash his hands, and be most careful never to take any food, solid or liquid, 
 until this has been done, and his teeth well brushed. The nails should be 
 always kept cut short, as well as the hair and beard, as otherwise the 
 poisonous dust will get deposited in them ; the clothes should be made as 
 tight-fitting at the neck and wrists as possible, and what is worn in the work- 
 shop should be left there, and another suit worn home. Warm baths should 
 be provided for the workpeople in all such works, a thing which can be done 
 at a very moderate cost, as if there is not actually hot water at hand, there is 
 always steam, by which a bath of cold water can be quickly warmed. Every 
 encouragement should be given to the workpeople to use these baths. 
 
 If circumstances prevent any of the men from leaving the works at meal 
 times, it is essential that a room be provided for meals completely detached 
 from the dust-producing works. Workmen who have already shown a pre- 
 disposition to plumbism should not be allowed to continue the work ; and all 
 persons having an open cut or sore should be excluded until it is quite healed. 
 
 As already mentioned, there are stages of the work when some form of 
 respirator is essential for the time, and fatty inunction is very useful to prevent 
 the hands being cracked. 
 
 The constant use of acidulated drinks, e.g. lemonade made with sulphmic 
 acid, or the administration of iodide of potassium for any length of time, is 
 quite inadmissible. Small doses of sulphur, or of sulphide of sodium, are 
 much less likely to undermine the health, and indeed can be continued for a 
 long time without inconvenience, and even advantageously. They favour the 
 formation of an insoluble sulphide of lead. 
 
 The drinking freely of milk, as is often recommended, can do no harm, if 
 it be not done with the mouth still foul with lead dust ; and if the milk be 
 not kept stored in the workroom, where it may become a vehicle of poison 
 to the drinker, if he escape other means of intoxication. 
 
 As a general measure of precaution it is highly desirable that the work- 
 
966 HYGIENE 
 
 men shoukl be carefully examined by a medical man at short intervals, 
 especial attention being shown to the ' gum-line,' the complexion, and the 
 state of the nervous system. 
 
 JS^o less cleanliness is to be constantly observed in the case of the work- 
 shops than in the person of the workman. They must be kept free from dust 
 by constant sweeping of walls, floor, and ceiling, and washing when needful. 
 The floors should be cemented, or well flagged, so that they can be thoroughly 
 cleaned, and also kept moist, to allay dust ; for which purpose a little chloride 
 of calcium may with advantage be apphed in solution to the floors. 
 
 Men inclined to excess in drinking are certainly more likely to be reckless 
 and regardless of their own and others' welfare, hence they are a danger in 
 lead works ; whether they are actually more susceptible to the action of lead 
 is not certain. Strict employers, careful of their men, may efiect a great deal 
 in encouraging them to attention to the rules of the shop, which should be 
 printed in large form and hung up in every room. Such care generally 
 bears good fruit in the health of the men, and the economical success of 
 the works. 
 
 PHOSPHOEUS 
 
 Phosphorus does not occur free in nature, but, owing to its great tendency 
 to combine with oxygen, it is usually found united with that element and 
 with metals. The glowing of phosphorus in the dark is due to slow oxida- 
 tion. Phosphate of calcium is the most important of the natural phosphates. 
 Dry bones contain some 88 per cent, of neutral phosphate of calcium. 
 The fossilised excrement of extinct carnivora, iiiuler the name of coprolites, 
 forms a large depot of phosphate of calcium, of which guano also largely 
 consists. 
 
 But for industrial purposes phosphorus is prepared from bone-ash, the 
 best form of apparatus being that known as Flecks'. The bones are calcined to 
 whiteness for some hours, then broken up or ground and treated with two- 
 thirds of their weight of sulphuric acid and fifteen to twenty parts of water. 
 The bone-ash is decomposed by the sulphuric acid, sulphate of calcium being 
 formed. Most of the phosphorus is found in the liquid as superphosphate of 
 calcium. The liquid is evaporated to the consistence of syrup, then mixed 
 with one-fourth its weight of charcoal, and dried by heating in an iron 
 vessel. The dried mass is heated to redness, and half the phosphorus 
 distils over into the water, beneath the surface of which the neck of the 
 retort opens, the other half remaining combined with calcium in the retort 
 as pyrophosphate. The phosphorus thus obtained is impure, containing 
 compounds of sulphur, silicon, carbon, also arsenic, charcoal, red amor- 
 phous phosphorus, &c. It is purified by pressing, when heated under hot 
 water ; or chemically by treatment with bichromate of potassium and sulphuric 
 acid, or with nitric acid. It is usually sold in the form of sticks, the melted 
 phosphorus being sucked into glass tubes by the use of india-rubber balls ; 
 or Seulert's apparatus is used — a tinned-copper vessel, from which the 
 liquefied phosphorus flows through a horizontal tube with a tap, connected 
 with which are suitable glass tubes into which the mass falls. When the 
 tubes are filled the tap is closed and the phosphorus allowed to solidify. 
 
 During the burning of the bones most offensive vapours are given off, 
 which also include offensive dangerous gases. The nuisance is perhaps more 
 annoying, like many similar ones, to those living around the works than to 
 those inside, but the danger is considerable to the workmen during various 
 parts of the manufacture. Works for the production of phosphorus should 
 not be allowed to be carried on in the immediate neighbourhood of towns. 
 
OFFENSIVE BUSINESSES 007 
 
 Besides this ordinary yellowish phosphorus, there exist other forms due 
 to molecular changes, without any recognisable change of chemical composi- 
 tion, A red or amorphous phosphorus is formed by heating phosphorus 
 in a closed vessel. It consists of red scales, which do not become ignited 
 on coming in contact with the air until it reaches a temperature above 
 SGC C. (= 500° F.), when it becomes reconverted into the ordinary form. 
 This red or amorphous phosphorus is prepared in a large way for the 
 manufacture of * safety ' matches, as follows : Phosphorus is heated in a 
 porcelain or enamelled iron digester, placed in a double bath, the one next 
 the digester being filled with sand or paraffin, the outer one with an amal- 
 gam of tin and lead, melting at 250° C. (=482° F.). A tube, furnished with 
 a stop-cock, leads from the digester, which is closed with a lid (which is 
 again covered with a lid enclosing the bath), and dips into a vessel of stone- 
 ware or copper, made on the model of a Woulfe's bottle. 
 
 The vapours from the digester pass through this tube, and are condensed 
 in this vessel. Any which are not condensed are carried off by a double- 
 bent tube, and discharged under mercury in another receptacle, a layer of 
 water being placed above the mercury. 
 
 Fumes resulting from the oxidation of the phosphorus, and of the arsenic 
 and sulphur which exist as impurities in it, are given off during this pro- 
 cess, including arseniuretted (AsHg) and sulphuretted hydrogen (H2S), 
 phosphuretted hydrogen (PHg), and phosphoric anhydride (PgOg). Hence 
 great precautions have to be taken by the workmen to avoid the risks involved 
 from inhaling these fumes. 
 
 Phosphorus is used on an enormous scale in manufacture, both as white 
 phosphorus, and in its amorphous (red) form. 
 
 The manufacture of matches is so important as to deserve more than passing 
 reference. In Sweden and Germany it is carried on on an enormous scale, 
 and there are in Neustadt alone some seventy factories. So early as 1816, 
 Derosne in Paris produced matches which were made with finely-divided white 
 phosphorus and sulphur. Some twenty years later an improved method was 
 introduced at a large manufactory estabhshed for the purpose at Frankfort-on- 
 the-Main, by Trevany, Eomer, and Bottger. Instead of chlorate of potassium, 
 an expensive and explosive material, liable to cause injury to the user, and 
 spoil the matches, they employed as the oxidiser peroxide of manganese, 
 nitrate of potassium, litharge, brown lead (Pb02, superoxide), nitrate of 
 lead, &c., and other substances whose combustion is less violent than is 
 the case of chlorate of potassium. Instead of gum arable they employed glue 
 to fix the mass to the wooden chips, a material which dries much quicker 
 than gum. The wood is cut by machinery into thin plates, the thickness of 
 a match, and these are subsequently cut into sticks of the required size. 
 Bound wooden matches are made by cylindrical knives, of which a number 
 of the requisite bore are fixed in a frame. In smaller factories the machine 
 labour is replaced by hand labour. The wooden stems are fixed in a frame, so 
 that the ends shall all stand at one level, 3,000 to 6,000 in each, and dipped 
 in the materials which make the 'head,' and fix it properly. As the 
 phosphorus is so highly inflammable, it is necessary to interpose some slower 
 medium between it and the wood, otherwise the phosphorus would be burned 
 out without the wood ever becoming ignited. Sulphur is very commonly used 
 for this purpose, when resinous wood is employed ; in the case of non- 
 resinous woods, such as elm, birch, poplar, aspen, &c., wax, paraffin, &c., are 
 used instead of sulphur. The sulphur is melted in a shallow iron pan, at as 
 low a temperature as possible, to avoid ignition, or the passage of the sulphur 
 into a thick unworkable condition. The most suitable temperature is about 
 
908 HYGIENE 
 
 235° F. In some works double-walled receptacles are used, with steam at tins 
 temperature circulating between. The wooden stems, fixed in their frame, 
 haA-ing been warmed on a sort of hot-hearth close at hand, to ensure more 
 even distribution of the molten sulphur, are dipped into it to the required 
 depth and raised, superfluous sulphur being removed by giving the frame 
 a shake. Li smaller factories considerable danger arises fi'om all the opera- 
 tions being carried on in the same place, and the same fire often being 
 employed for the sulphuring and the subsequent application of the igniting 
 material. Owing to this the workmen are exposed to the vapours of phos- 
 phorus, as well as to others arising during the sulphuring, which is often 
 c;ii-i-ied on at such a temperature as to cause danger not only of its ignition 
 but also the development of sulphur vapour to a most distressing degree. 
 
 The igniting mass is formed of white phosphorus, which should not 
 amoiuit to more than G to 8 per cent, of the mass ' melted under hot water, 
 and mixed with some of the oxidising materials already mentioned, and 
 some kind of material to fix it on the match (usually glue, dextrin, gum, &c.), 
 and some colouring material (such as umber, ultramarine, lampblack, and 
 various aniline colours, &c.) ; this is used either hot or cold. The fixing 
 medium is first dissolved in water, then heated in an enamelled iron pot, 
 with a very exactly fitting lid ; the phosphorus is then added, and the lid, to 
 which a stirring apparatus is fixed, carefully closed. When the phosphorus 
 is thoroughly distributed, the colouring matter and oxidiser are added, 
 and after careful stirring the operation is complete. 
 
 The likelihood of phosphorus fumes escaping during these processes, to the 
 detriment of the workmen, is very great, and to ob\date tbe risks it requires 
 careful management and good appliances. Subsequently the matches are left 
 in the frames in warm air (not much above 85° F.), until they are quite dried, 
 when they are taken out of the frames, and made up in bundles, or put direct 
 into boxes. The drying should never be done by the direct heat of a fire, 
 but should always be effected by a current of warm air. In some works — ■ 
 and it is most desirable that the method should be universally adopted — a 
 good deal of this work is done by machinery. The workmen are exposed to 
 great risk here from vapour arising from the matches, from fire, and from the 
 action of the match heads on the skin, especially if it should be raw or sore. 
 
 ' Safety ' matches are made with red or amorphous phosphorus, which, 
 as stated, does not take fire in the air until heated above 2G0° C. (=■ 500° F.), 
 when it is converted into the ordinary form of phosphorus, and burns with 
 formation of phosphoric anhydride. The phosphorus is contained in the 
 rough rubbing surface on the box, and not in the match-heads. This ignit- 
 ing material is fixed by glue, or other suitable medium, to the surface, and 
 is composed of chlorate of potash, from 10 to 40 per cent, iron pyrites, 
 peroxide of manganese, powdered glass, sulphide of antimony, and a suitable 
 •cidhesive — e.g. of glue. 
 
 These materials are ground and mixed to a fine paste. Great care is 
 requisite to prevent the chlorate of potash exploding, and with this object 
 it is ground in a wooden vessel, provided with a special cover for allowing 
 immediate escape to the gases should an explosion occur. The adhesive 
 is first dissolved in boiling water, next the lead compounds are added, and the 
 other constituents afterwards ; the chlorate of potash being added last. The 
 rubbing surface is prepared in a similar way, the amorphous phosphorus 
 being added last. 
 
 ' In England the proportion is commonly much larger, but this only renders the match 
 more dangerous as an explosive, and as affecting the health of the maker ; a smaller pro - 
 portion is quite as efficient for ignition. 
 
OFFENSIVE BUSINESSES 969 
 
 The match-sticks are dipped in a mixture consisting of chlorate of potash, 
 peroxide of manganese, bichromate of potash, red lead, subsulphide of lead, 
 and sometimes picric acid, with a suitable adhesive, such as starch, glue, 
 &c. As in the case of ordinary matches, some material is added to diminish 
 the violence of the ignition, such as sulphur, oxide of iron, umber, powdered 
 glass, &c.^ 
 
 The people engaged in the manufacture of phosphorus and its compounds, 
 and in their utilisation for commercial purposes, are exposed to grave danger 
 at various stages of the work, and at certain stages great nuisance is caused 
 to those living around the works. Those engaged in the earlier stages 
 of bone-burning, and such preparations, may live fairly healthy lives, if even 
 moderate care be taken, but the manufacture of matches is often carried on 
 so as to imperil the health and lives of the workpeople grievously. There is 
 one disease, unfortunately too well known, which is specific to those engaged 
 in this trade, that is, the disease of the bones (phosphorus-necrosis), which is 
 mostly limited to the jaws, and more particularly to the lower jaw. 
 
 There is no reason why the bone-burning should not be carried on sub- 
 ject to the action of a fan which would conduct the offensive fumes either 
 directly into a furnace, where the offensive odour would be destroyed, or still 
 better, into a reservoir containing water, where they would be condensed, and 
 the accompanying fumes would either be absorbed or conducted further, after 
 passing through the bath, into a high chimney. Dust from the burned 
 bones is very liable to cause irritation of the eyes and mucous membranes, 
 wliich is often very troublesome. 
 
 During the subsequent distillation of the bones, very offensive vapours 
 are produced, which can be best treated as suggested above. When the 
 bones are treated with sulphuric acid, sulphuretted hydrogen and carbon 
 dioxide are freely developed, as well as smaller quantities of compounds of 
 hydrogen with chlorine, fluorine, and arsenic, also hydrocyanic acid. Sub- 
 sequently, when the mass becomes heated, sulphuric and sulphurous acids 
 are evolved in large quantities, and, as the sulphuric acid is impure, arsenic 
 and arsenious acid are always present. Active ventilation is absolutely 
 essential to prevent danger from these gases. It has been suggested to 
 conduct them into a receptacle filled with burned bones — which would 
 facilitate their disintegration. 
 
 During the distillation of the impure phosphorus, dangerous gases of a 
 similar character are evolved, and the fire must be gradually lowered to avoid 
 ignition of the phosphorus which has condensed on the sides of the recep- 
 tacles. The workmen who fill and empty the retorts should always be care- 
 fully dressed, so as to protect as much of the surface of the body as possible, 
 and wear masks provided with glass protectors for the eyes, while the 
 respiratory organs should be protected by cotton-wool or cloths. In this stage 
 of the work, free ventilation to dilute and expel the gases is essential. When 
 the retorts have been heated, they must never be opened more than is abso- 
 lutely necessary, and they must be slowly cooled to prevent the risk of fracture, 
 and the escape of phosphoric vapours in great quantities. In the rectifica- 
 tion of phosphorus with nitric acid, extreme care must be taken to make all 
 parts of the apparatus which conducts away the nitrous fumes (vapour of 
 
 ' Efforts, which it is to be hoped may be crowned with success, are continually being 
 made to produce a match without the use of phosphorus. As oxidisers the following 
 have been tried: nitrate of lead, picrate, chlorate, bichromate and permanganate of 
 potash, &c. ; as the igniting substance, iron pyrites, sulphur, carbon, (fee, ; and as sub- 
 stances to diminish the force of explosion, sand, powdered glass, umber, with the same 
 adhesives as are used in the case of other matches. 
 
970 HYGIENE 
 
 phosphorus, &c.), air tight. The admixture of a stream of COg would be 
 advantageous as diminishing the risk of explosion. 
 
 As the vapour of phosphorus, owing to its weight, sinks to the ground, it 
 is of the greatest importance to employ aspii'ators to enforce an upward 
 current of air in the workshops. 
 
 The storing of phosphorus is a matter wliich should be done with the 
 greatest foresight and care. It should always be kept in glass or earthen- 
 ware vessels in water, and still better in such vessels which are placed inside 
 another of the same kind for greater safety. These should be kept in a cool 
 place away from all risk of breakage. 
 
 During carriage, these should be enclosed in met:»llic (tin) vessels filled 
 with water, and made to hold only a certain maximum quantity, and not to 
 exceed a certain maximum weight. They should be provided with proper 
 means for bemg lifted, to avoid danger, and invariably be labelled to show 
 which is the upper side. 
 
 The manufacture of red or amorphous phosphorus may lead to the 
 development of similar gases to those evolved in the distillation of white 
 phosphorus, owing to the impurities in the phosphorus which is used for 
 conversion into the red form ; but though cases of intoxication do occur 
 from this substance, they are rare as compared with those caused by white 
 phosphorus. The operations can, however, be conducted in a less dangerous 
 manner, but if care be not taken, in the closing of the digester, to make it air 
 tight, and in the opening of it to avoid the escape of the noxious fumes, the 
 workmen will unavoidably be exposed to most offensive and dangerous fumes. 
 
 That water which has been used during the process of manufacture, and 
 contains any phosphorus or other dangerous ingredient, should not be 
 allowed to leave the works untreated, and more particularly to enter any well 
 or stream, is a matter of primary importance. It has been found profitable 
 and otherwise advantageous to evaporate such water in shallow pans placed 
 mside the machmery. A considerable quantity of phosphorus may be re- 
 covered in this way. 
 
 The greatest of aU the industries in which phosphorus is engaged is 
 match-making. From the description given of the process, the nature of the 
 dangers incurred will already be understood. 
 
 As might be expected, all the eAdls connected with the trade are found in 
 their worst form in small factories, and where the work is carried on in the 
 workmen's houses. Here it is impossible to provide the large airy rooms, 
 the artificial ventilation, the air-tight receptacles, and other things which are 
 essential to the carrymgon the work without serious danger to the workpeople. 
 
 At the very commencement of the operation of match-making, the work- 
 people are exposed to great, and even serious inconvenience from a cause 
 which is quite preventable. When the cut chips are brought for dipping, the 
 bundles contain a great quantity of the finest wood dust, which is liable to 
 cause irritation of the respiratory passages. This could be easily prevented 
 by exposing the chips to the action of a fan for a short time. 
 
 The more serious affections, however, from which the match-makers suffer 
 are those arising from the presence of phosphorus in the match-heads, and 
 from the sulphur employed in the manner described. If the sulphur be 
 heated too much there is danger of ignition, and of the development of large 
 quantities of noxious fumes. At the best it requires more attention than is 
 usually devoted to the matter to prevent the temperature of the sulphur 
 being unnecessarily raised, and the consequent production of SO2 in consider- 
 able quantities ; there is always some given off during this process. 
 
OFFENSIVE BUSINESSES 971 
 
 The pans in which this sulphuring is done should be covered with a 
 proper lid, provided with a pipe to conduct away the fumes into a tall 
 chimney, if they cannot be utilised, as such things usually can be. In small 
 factories the sulphuring and the dipping in the explosive, which contains 
 the phosphorus, are often done at the same fire, and with no arrangements 
 for protecting the workmen from the combined action of sulphur and phos- 
 phorus fumes. 
 
 The preparation of the explotsive material is the most dangerous part of 
 the whole manufacture. 
 
 This should be absolutely prohibited in cases where it can only be done 
 in open vessels ; and the provision of proper vessels heated by steam or 
 water, with air-tight covers, means of carrying off offensive vapours, and 
 safety-valves to prevent danger from explosion (by permitting the ready 
 escape of gases suddenly evolved) should be made a sme qud non. 
 
 The employment of a warm adhesive (glue, &c.) has such disadvantages 
 that the use of cold starch and dextrin has been suggested as an advanta- 
 geous substitute. But this does not quite meet the difficulties, as it is necessary 
 to dry the cold adhesive at an increased temperature, which in turn leads to 
 the evolution of phosphorus vapours. When gum has been used as a fixer, 
 the 'head' is very liable to soften, come off, and adhere to the hands if 
 they are at all moist from sweat, &c., and it is on the whole better to use 
 glue as a fixer, as it dries so much quicker (30 to 40 minutes), and its dis- 
 advantages are so much more quickly got over. 
 
 The removal of the finished matches from the frames, and the putting 
 them up in bundles for boxing, or in larger packets, involves considerable 
 danger of ignition ; and some part of the ' heads ' is liable to get rubbed off 
 in the form of dust, and to adhere to the skin and cause absorption or 
 irritation of any existing raw places. Great caution is required in the 
 operation, and vessels of water should always be close at hand. 
 
 The importance of large roomy workshops with good ventilation, assisted 
 by fans or flues set in action by heat (connection with the chimney, &c.), 
 cannot be over-rated, the ventilation being directed upwards, to counteract 
 the tendency of the heavy vapour to sink ; extreme personal cleanliness, 
 maintained by frequent baths and washing of the mouth and hands, espe- 
 cially before partaking of food, should also be constantly observed. 
 
 No food or drink should be taken in the workshop, and the working 
 clothes should not be worn at home. 
 
 A very important condition of preservation of the health of these workers 
 is the diminution of the work to the shortest possible time, and, where it is 
 possible, to allow those engaged in the more dangerous part of the work (e.g. 
 the preparation of the material for ignition) to take on at intervals some 
 other work for a time. The benefits to be derived from the presence of the 
 vapour of turpentine, as described first by Letheby, have been generally 
 recognised, and in many works little vessels of tin containing turpentine are 
 placed in the workshops, and the workpeople carry flasks or sponges attached 
 by a string at their chests, so that they may have the advantage of breathing 
 air impregnated with the vapour. Its administration internally in case of 
 phosphorus intoxication is recommended. Advantage is also to be derived 
 from washing the mouth with a weak alkaline solution — e.g. carbonate of 
 sodium. Washing the teeth with this, or with lime-water and charcoal, is 
 also to be recommended. The use of masks filled with charcoal has also 
 been recommended. 
 
 Where the benefits of the oxidation derived from turpentine vapours 
 cannot be utilised, owing to mdividual inability to endure the turpentine 
 
972 HYGIENE 
 
 fumes, it has been recommended to use watery solution of sulphate of copper, 
 as it leads to precipitation of phosphorus as phosphate, along with metalhc 
 copper. The addition of charcoal, a powerful absorbent of phosphorus, to 
 the solution would also be beneficial. 
 
 The effects of poisoning with phosphorus may be either acute or chronic. 
 The symptoms appear much more rapidly after swallomng phosphorus when 
 finely divided than when m a solid piece. 
 
 Cln-onic intoxication is generally slow and insidious, and seldom shows itself 
 for tliree to four years after the commencement of work in a factory. It is much 
 more common in match-factories than in any other works connected with the 
 use of phosphorus. Before any very marked symptoms are noted, there are 
 observable loss of flesli and a gradual change of colour to a yellowish tinge. 
 The appetite fails, and gastric and intestinal disorders are common ; indeed, 
 gastric catarrh might be commonly supposed to be tlie chief ailment. Head- 
 ache and dulness of the mental faculties become marked, and dyspnoea and 
 bronchitis are common. Toothache and pains in the jaws become almost 
 constant ; later on the gums swell, become tender, and ulcers form, discharg- 
 ing large quantities of stinking matter, and the ulceration tends to extend 
 and become very destructive. At the same time the breath becomes very 
 offensive. 
 
 Then the bone can generally be found to be diseased by the use of the sound. 
 In a more advanced stage the gums as well as the periosteum become quite 
 detached from the bone, and the alveolar processes are exposed to view. 
 The course of events is usually more rapid and serious when the lower jaw 
 is attacked than when the upper one is, disease of the latter being much the 
 less frequent, in the proportion of about three to five, possibly because the 
 lower jaw is more in contact with the saliva, which always contains phos- 
 phorus — the cause of all the evil. Sometimes the necrotic action proceeds 
 stealthily, and not in the somewhat stormy manner which is usual, and the 
 patient will lose many teeth before any other serious symptoms appear ; or a 
 long sequestrum may be discharged before he has realised the true state of 
 affairs. The existence of carious teeth is commonly assumed to be the chief 
 agency in the commencement of the disease, by giving an entry to the phos- 
 phorus into the interior. General breakdown of the health is a natural 
 result of such a condition, the intoxication, pain, and malnutrition combining 
 to reduce the patient to the most miserable state. The frequency of this 
 frightful disease, according to Hirt, was formerly not less than 11 to 12 
 patients yearly to every 100 matchmakers, without regard to age or sex ; 
 its gravity may be judged from the statement that one in two attacked are 
 said to die, the condition of many who recover from a severe attack being 
 most wretched. It is now not common in this country. 
 
 The complete suppression of the use of white phosphorus is the great 
 preventive. Failing that, suitable large rooms ; good ventilation artificially 
 conducted upwards ; suitable apparatus to carry off vapours and dust ; and 
 personal care on the part of the workpeople — are what must be rehed on to 
 avert or minimise the evils. 
 
 ZINC 
 
 Zinc is never found native, but its ores occur in abundance. The chief 
 are calamine, or carbonate of zinc, blende, or sulphide of zinc, and a red oxide, 
 the colour of which is due to the presence of the oxides of iron and manganese. 
 
 The extraction of zinc from its ores commences with the crushing of the 
 ■ore, which is subsequently roasted, dming which process, when blende is used, 
 the sulphur passes into sulphur dioxide, the zinc becomin oxidised. The 
 
OFFENSIVE BUSINESSES 973 
 
 roasted ore is mixed with half its weight of powdered coke or anthracite and 
 subsequently reduced (deoxidised) by one of two processes, known as the 
 English and the Belgian. The English method is one of distillation down- 
 wards {per descensum). The above mixture is put into crucibles having 
 an opening in the bottom with a short iron pipe, and a lid which is carefully 
 luted over. A number of these crucibles are placed on the fire-bars within 
 a circular furnace. After a time carbonic oxide escapes through the pipe 
 in the bottom, and burns with a blue flame, which becomes white and 
 deposits white fumes of oxide of zinc. This flame is then extinguished, 
 and a longer tube attached, through which the metal falls into vessels 
 provided to receive it below. As the zinc is volatile at high temperatures, 
 and boils at a bright red-heat, it distils downwards in this way. The metal 
 thus obtained is impure and contains a good deal of oxide and requires re- 
 melting and skimming, after which it is cast into ingots ; but the commercial 
 zinc usually contains some lead and iron as impurities. 
 
 Zinc is very little acted on by the atmosphere. It loses its brilliancy 
 when exposed to moist air, owing to the formation of a thin pellicle of oxide, 
 which protects it from further change. This property and the facility with 
 which it can be rolled into sheets when hot make it available for many uses. 
 It is largely used in the form of ' galvanised ' iron-sheets for roofing, &c. 
 The sheets of iron are covered with a coating of zinc either by being dipped 
 in molten zinc, covered with a layer of sal-ammoniac, which dissolves the oxide 
 which forms on the zinc ; or by first coating the zinc with tin, by galvanic 
 action, and then dipping in the molten zinc. 
 
 Galvanised iron wire is also very largely in use for various purposes, of 
 which the most important are for telegraph wires and for wiring down cham- 
 pagne, mineral waters, and other effervescing drinks. Brass and copper are also 
 sometimes zinced. Gralvanic zincing is done by placing the metal to be 
 galvanised in a zinc bath filled with a saturated solution of sulphate of zinc. 
 
 Zinc is also used to form important alloys ; brass consists of one part of 
 zinc and one of copper, and german silver is brass to which some nickel has 
 been added. Zinc plates are extensively used as the oxidisable plate in a 
 great many forms of galvanic batteries, owing to its solubility in dilute acids, 
 with evolution of hydrogen. 
 
 Zinc is not absorbed by the skin, and its effects on the organism are 
 limited to absorption of its vapour, through inhalation, or inhalation of 
 the dust. Dust is created in large quantities in the grirding of the oxide, 
 and precaution should be taken to have this done in suitable closed chambei s 
 and to protect the workmen by respirators when they are obliged to enter 
 the grinding chamber. 
 
 Exposure to the action of the vapour of zinc for some time may produce 
 serious symptoms of intoxication : cough and difficulty of breathing, headache, 
 giddiness, stiffness in the limbs, sickness, and vomiting. Copious sweating 
 sometimes occurs. 
 
 The severe colic and irritation of the skin which is sometimes observed in 
 persons exposed to the action of zinc dust, &c., is most hkely due to the action 
 of impurities, e.g. lead or arsenic, and not to zinc. But the powder, acting 
 merely as a mechanical irritant, may cause considerable cutaneous irritation. 
 
 Some writers consider that the nervous system is injuriously affected by 
 exposure to the action of zinc, but only after many years, the reflex and 
 motor systems being chiefly affected. It has undoubtedly been noticed that 
 farmyard poultry (especially ducks) have been affected with spasms of the 
 legs and even paralysis when ashes from a zinc furnace had been left in their 
 feeding ground. 
 
■974 HYGIENE 
 
 The proper condensation of the vapour is the great desideratum, and 
 vigorous ventilation to free the worlirooms from it. 
 
 Those engaged in the wiring of champagne bottles with ' galvanised ' wire 
 have been observed to sufl'er from stomatitis, inflammation of the gums, 
 sahvation, fcetid breath, ulcers of the gums and tonsils, and similar symptoms 
 have been noticed among coopers using zinced iron hoops. It appears not im- 
 probable that these dangerous symptoms were due to arsenic, so commonly 
 present in commercial zinc. 
 
 It is important that the vapour and dust be not allowed to escape from 
 the works so as to injure the vegetation or water-courses in the neigh- 
 bourhood, and wash-water, &c., from the works should not be admitted into 
 streams, wells, &c. 
 
SLAUGHTER-HOUSES 
 
 AND 
 
 THEIK ADMINISTEATION 
 
 BY 
 
 E. W. HOPE, M.D., D.Sc. 
 
 ASSISTANT MEDICAL OFFICER OF HEALTH FOR THE CITT AND PORT OF LIVERPOOL 
 LECTURER OX PtTELIC HEALTH AT UNIVERSITY COLLEGE, LIVERPOOL 
 
SLAUGHTER-HOUSES AND THEIR ADMINISTRATION 
 
 Among the many industries which exercise a direct or indirect effect upon 
 the pubhc health, there are probably none of greater importance than those 
 which centre in the meat supply. Little need be said in support of the need 
 for measures to ensure that meat intended for consumption as food shall be 
 good and wholesome in quality. Apart, however, from the actual quality of 
 the meat, and the processes by which it is prepared for sale and consumption, 
 we have also to deal (a) with the transport and storage of live-stock, as also 
 with the preservation of imported carcases, (b) with the keeping of animals, 
 (c) with the slaughtering of animals, and (d) to a certain extent with several 
 important branches of industry in which animal matters or substances of 
 animal origin are dealt with. The manner in which this variety of associated 
 businesses is conducted in different towns and districts is very diverse : the 
 general principles may be the same, but local custom, expediency, profit, 
 or convenience, or extent of supervision lead to variations in detail which 
 exercise a great influence upon the general aspect of the business and its 
 effects upon health. 
 
 It is well known that among the commonest causes of ' nuisances, or 
 conditions prejudicial to health,' is pollution of the atmosphere, which not 
 only produces bodily discomfort, but tends by continuance to induce an 
 appreciable impairment of health and strength. A large abattoir, or even a 
 small slaughter-house, may be an important element of atmospheric im- 
 purity, and the more dense the population in its vicinity, the more necessary 
 it becomes to mitigate its evils by careful management ; for under appropriate 
 conditions of site, structure, and management the business may be so carried 
 on as to cause neither offence nor injury of any kind. There is no difficulty 
 whatever in laying down the general principles upon which appropriate means 
 of preventing or minimising nuisances must be based, but in dealing with any 
 particular establishment it is often a matter of difficulty 'to apply these 
 principles to the best advantage, since their application depends upon a variety 
 of considerations, an important one frequently being original defects of site 
 and structure, arising from attempts to adapt old buildings, not originally in- 
 tended for the purpose, to the requirements of slaughter-house, lairage, 
 or other offices ; this often implies an absence of conveniences which are 
 necessary not only to facilitate cleansing but to prevent defilement. Or the 
 nuisance may be dependent upon (1) accumulation of filth on or about the 
 premises, or on its removal from the premises in an offensive condition ; (2) on 
 a generally filthy condition of the interior of the buildings and the premises 
 and utensils generally ; (3) on an improper mode of disposing of offensive 
 refuse, liquid or otherwise, and carelessness in the reception of offensive 
 materials. For these the obvious remedy is a supervision that will ensure 
 cleanliness in the broadest sense of the term, and a close observance of care- 
 fully drawn bye-laws which bear upon the subject. 
 
 The importation and transport of cattle are regulated by orders of the Privy 
 Council under the Contagious Diseases (Animals) Acts. An order under this 
 
 VOL. I, 3 R 
 
978 HYGIENE 
 
 Act provides for landing-places for such foreign animals as are subject to 
 slaughter ; it also defines quarantine stations for animals not subject to 
 immediate slaughter, and also specifies landing-places for foreign animals 
 which are permitted to travel, being subject neither to quarantine nor slaughter. 
 Most of the livestock imported from or through the United States is landed 
 at Liverpool (Woodside), and as these cattle are not permitted to travel, they 
 are slaughtered on landing, the carcases being forwarded to their destination. 
 Canadian cattle are subject to a short detention or ' quarantine,' and to an 
 examination by an inspector appointed by the Privy Council, upon whose re- 
 sponsibihty they are passed on. No restrictions of these lands are placed 
 upon the moving of animals within the United Kingdom, but the Contagious 
 Diseases (Animals) Acts contain pro%isions restricting the movement of 
 cattle within infected areas and under certain conditions, and these Acts 
 require all railway trucks, lairages, pens, &c., used in the transport or tem- 
 porary accommodation of cattle to be lime-washed and purified, before twelve 
 o'clock on the day following their use, or before they are again used for any 
 purpose. 
 
 As evidence of the large import trade it may be mentioned that close on 
 400,000 cattle, 383,000 sheep, and 156,000 swine are landed annually at the 
 port of Liverpool alone, besides 163,000 tons of fresh and preserved meat. 
 
 The following extracts from the Animals Order regulating disinfection 
 of vessels and transit by water are important : — 
 
 Vessels 
 
 100.— (1) A vessel usee! for carrying animals by sea, or on a canal, river, or inland 
 navigation, shall, after the landing of animals therefrom, and before the taking on board 
 of any other animal or other cargo, be cleansed and disinfected as follows : 
 
 (i) All parts of the vessel with which animals or their droppings have come in contact 
 shall be scraped and swept : then 
 
 (ii) The same parts of the vessel shall be thoroughly washed or scrubbed or scoured 
 with water : then 
 
 (iii) The same parts of the vessel shall have applied to them a coating of lime-wash : 
 except that 
 
 (iv) The application of lime-wash shall not be compulsory as regards such parts of the 
 vessel as are used for passengers or crew. 
 
 (2) The scrapings and sweepings of the vessel shall not be landed unless and until 
 they have been well mixed with quicklime. 
 
 (3) Except that in the case of a ferry-boat or other vessel which makes short and 
 frequent passages across a river or an arm of the sea or other water, it shall be sufficient 
 if the ferry-boat or vessel be cleansed and disinfected once in every period of twelve hours 
 within which it is so used. 
 
 Fodder and Litter 
 
 101. — (1) All partly consumed or broken fodder that has been supplied to, and all 
 litter that has been used for or about, animals carried by sea, or on a canal, river, or 
 inland navigation, shall, when landed from the vessel, be forthwith well mixed with quick- 
 lime and be effectually removed from contact with animals. 
 
 (2) Nothing in this Article shall apply to fodder or litter supplied to or used for or 
 about foreign animals. 
 
 Movable Gangways and other Apparatus 
 
 102.— (1) A movable gangway or passage-way, cage, or other apparatus, used or 
 intended for the loading or unloading of animals on or from a vessel, or otherwise used in 
 connection with the transit of animals by sea, or on a canal, river, or inland navigation, 
 shall, as soon as practicable after being so used, be cleansed as follows : 
 
 (i) The gangway or apparatus shall be scraped and swept, and all dung, litter, and other 
 matter shall be effectually removed therefrom : then 
 
 (ii) The gangway or apparatus shall be thoroughly washed or scrubbed or scoured with 
 water. 
 
 (2) The scrapings and sweepings of the gangway or apparatus, and all dung, litter, and 
 
SLAUGHTER-HOUSES AND THEIR ADMINISTRATION 979 
 
 ■other matter removed therefrom shall forthwith be well mixed with quicklime, and be 
 leifectually removed from contact with animals. 
 
 Landing Places 
 
 110. — (1) Where an animal at a place of landing or place adjacent thereto is affected 
 •with disease, that place and every other place where the animal is or since landing has 
 lieen shall not be used for any animals other than animals brought thereto with that 
 animal (in the same vessel or otherwise) unless and until the place has been, as far as 
 ■practicable, cleansed and disinfected. 
 
 (2) Nothing in this chapter shall apply to a Foreign Animals Wharf, nor to a Foreign 
 .Animals Quarantine Station, nor to a landing-place for foreign animals. 
 
 Offences 
 
 172. — (1) If the slaughter of animals is not commenced at the time directed by the 
 Privy Council under this part, or completed in accordance with the provisions of this part, 
 the person failing to cause such slaughter to be so commenced or completed shall be 
 ■deemed guilty of an offence against the Act of 1878. 
 
 (2) If any dung of animals, or any fodder, litter, utensils, pens, hurdles, fittings, or 
 ■ other thing is landed or removed in contravention of this part, the owner thereof, and the 
 owner and the lessee and the occupier of the place of landing or other place where or from 
 which such dung or other thing is landed or removed, and also in the case of the landing 
 ^thereof, the owner and the character and the master of the vessel from which the same is 
 landed, shall, each according to and in respect of his own acts or defaults, be deemed 
 guilty of an offence against the Act of 1878. 
 
 Fittings of Vessels 
 116. — (1) Every place used for animals on board a vessel shall be divided into pens by 
 substantial divisions. 
 
 (2) Each pen shall not exceed nine feet in breadth or fifteen feet in length. 
 
 (3) The floor of each pen shall, in order to prevent slipping, be strewn with a proper 
 ^quantity of litter or sand or other proper substance, or be fitted with battens or other 
 proper footholds. 
 
 (4) Every such place, if enclosed, shall be ventilated by means of separate inlet and 
 -outlet openings, of such size and position as will secure a proper supply of air to the place 
 in all states of weather. 
 
 Overcrowding 
 117. — A vessel bringing animals to any port or place in England or Wales or Scotland 
 from any port or place in the United Kingdom shall not be overcrowded so as to cause 
 .unnecessary suffering to the animals on board. 
 
 Shorn Sheep 
 118. — Between each 1st day of November and the next following 30th day of April 
 .(both days inclusive) shorn sheep shall not be carried on the deck of a vessel, except 
 where they were last shorn more than sixty days before being so carried. 
 
 Gangivays for Sheep-Pens 
 119. — Where sheep are carried on the deck of a vessel, proper gangways shall be pro- 
 -yided either between or above the pens in which they are carried. 
 
 Detention 
 120. — Animals landed from a vessel shall, on a certificate of an Inspector of the Privy 
 Council, certifying to the effect that the provisions of this chapter, or some or one of 
 them, have not or has not been observed in the vessel, be detained, at the plaoe of land- 
 ing, or in lairs adjacent thereto, until the Privy Council otherwise direct. 
 
 Shipping and Unshipping Places 
 
 Water 
 
 121. — At every place where animals are put on board of or landed from vessels, pro- 
 
 ■vision shall be made, to the satisfaction of the Privy Council, for a supply of water for 
 
 animals ; and water shall be supplied there, gratuitously, on request of any person having 
 
 charge of any animal. 
 
 Food 
 122. — At every place where animals are landed from vessels, provision shall be made, 
 to the satisfaction of the Privy Council, for the speedy and convenient unshipment of 
 
 3b2 
 
980 HYGIENE 
 
 animals and for a supply of food for them ; and food shall be supplied there, on request, 
 of any person having charge of any animal, at such price as the Privy Council from time- 
 to time approve. 
 
 Landing and Treatment of Dung, Fodder, d;c., of Animals winch are intended to be 
 landed at a Foreign Animals ^V^Mrf 
 
 164. — (1) No dung of foreign animals that have been or are intended to be landed at a 
 Foreign Animals Wharf, and no partly consumed or broken fodder that has been supplied 
 to such animals, and no litter that has been used for or about such animals, shall be 
 landed without the previous consent in writing of the Local Authority of the place where 
 it is intended to land such dung or other thing. 
 
 (2) All such dung and all such partly consumed or broken fodder and all such litter 
 shall, when so landed, be forthwith well mixed with quicklime and be effectually removed 
 fi'om contact wrth animals. 
 
 Offences 
 
 126. — If anything is done or omitted to be done in contravention of any of the fore- 
 going provisions of this part, the owner and the charterer and the master of the vessel in 
 which — and the owner and the lessee and the occupier of the place where animals are put 
 on board of or landed from vessels at which — and the railway company carrying animals 
 on or owning or working the railway on which — and also, in case of the overcrowding of 
 a vessel, or of a railway truck, horse-box, or other vehicle on a railway, or of the carrying: 
 on a railway of sheep shorn and unclothed, the consignor of the animals in respect of 
 which (as the case may be) — the same is done or omitted, shall each, according to and 
 in respect of his or their own acts or omissions, be deemed guilty of an offence 
 against the Act of 1878. 
 
 In regard to the storage of livestock, it is evident that animals sent to- 
 a slaughter-house are not, under ordinary circumstances, detained there for 
 any lengthened period ; nevertheless, as soon as one batch is slaughtered 
 another set replaces the first, and the result, so far as the keeping of animals, 
 is concerned, is precisely the same as would be the case were a number kept 
 permanently upon the premises. The Public Health Act, the Nuisances 
 Kemoval Act, and local Acts generally recognise the fact that animals may 
 be so kept as to be a nuisance injurious to health, and the necessity for the 
 regulation and control of the keeping of livestock — more especially where 
 human population is aggregated— is sufficiently obvious. 
 
 The nuisances arise from defects in structure of the lairages, from in- 
 sufficient space, from defective drainage and water supply, and accumulations 
 of filth and the like. Soakage of putrefying animal matters through badly 
 paved floors is one of the means of pollution of soil and contamination of 
 wells, streams, &c. Defective ventilation is perhaps the evil most commonly 
 met with in places where animals — more especially dairy cows — are kept in 
 towns, and the results are very serious. Stall-fed dairy cows are exceedingly 
 prone to tubercle, and it is not improbable that 30 or 40 per cent, of all dairy 
 cows kept in towns are affected by it. Confinement, bad air, and the drain 
 of constant milking are doubtless the predisposing causes. 
 
 The remedies for the harmful conditions arishig from the keeping of 
 animals are to be sought in the proper construction of the sheds, cleanly 
 management, and proper storage of food, &c. These points will be referred 
 to in connection with the lairages of pubHc abattoirs. We turn meantime to 
 the slaughtering of animals. 
 
 Slaughter-houses, be they public or private, large or small, require to be 
 specially constructed to meet the necessities of the trade carried on within 
 them. Of equal importance is it that their site in regard to inhabited 
 dwelhngs should be carefully chosen. It is instructive to read the accounts 
 of medical officers of health, both metropolitan and provincial, of conditions 
 which existed some few years back in some of the slaughter-houses of their 
 
SLAUGHTEB-HOUSES AND THE IB ADMINISTBATION 981 
 
 respective districts. It appears that in one important and populous metro- 
 politan locality there were twenty-four slaughter-houses, which, with one 
 ■or two exceptions, were situated side by side. * All of them,' we read, ' have 
 a direct communication with a shop facing the street, and six of them have 
 no other means for the entrance of cattle than by their passing across the 
 public footways and through the shops, which are low and narrow.' They 
 appear to have been separated from one another mostly by dwarf partitions ; 
 and from the lairs, which are often employed as hanging sheds for the meat, by 
 like partitions of wood. When reported on they were described as being ' in 
 a state of general disrepair ; the roofs dilapidated, the flooring uneven and 
 broken, the side walls filthy and blood-stained, the drainage defective and 
 •sluggish, the water supply inadequate and badly placed. Accumulations of 
 dung, offal, and blood were general, and liquid manure was allowed to run 
 freely into the sewers.' Clearly such premises as these cannot be other 
 than prejudicial to health, and the question is whether entire reconstruction 
 or removal altogether from the district would be the more efficient remedy. 
 Again, we learn from a report upon another urban district that slaughtering 
 is (or was) 'carried on in shops, lairs, stables, cellars, inhabited dwelling 
 rooms and passages, as well as in open yards and on door steps ; the 
 slaughtering places, moreover, being in a majority of instances closely con- 
 tiguous to the residence of the butchers, and generally approached through 
 the shop. Most of the slaughter-houses are not open to the roof, living or 
 bed rooms being situated over them, there being, moreover, in a large pro- 
 portion of them, direct communication with the inhabited portions of the 
 premises. Many of the slaughter-houses are absurdly small ; the ventilation 
 is generally described as deficient, bad, very bad, or " none," while m a con- 
 ;siderable number there is no water supply within the slaughter-house.' It 
 need hardly be added to complete this astonishing picture that lairage is, 
 as a rule, conspicuous by its absence, and that, where provided, it is of the 
 most inadequate description, whether regard be had to the dimensions or 
 position, or to the relations of the lairs to other parts of the premises. 
 Another account is given, ' where sheep and oxen are slaughtered in the 
 shop forming part of the dwelling-house, it is customary to see a blood-hole, 
 about two feet square and eighteen to twenty-four inches deep, in the middle 
 of the shop fioor. In this at the time of slaughtering the blood is collected, 
 and the practice is to throw in sawdust, with the object of sopping up the 
 "blood, so as to permit of the blood being readily removed the following 
 morning by the public scavenger. Most of the blood-holes, however, when 
 inspected, had not been thoroughly emptied and cleansed, enough blood 
 having been left at the bottom and corners to give rise to putrid emanations, 
 whilst the effluvia from animals pounded within the house difi"used them- 
 selves throughout it.' These of course are accounts of conditions existing in 
 vslaughter-houses a few years back, and it may be said that they do not apply 
 exactly to existing conditions ; however, an approximation to the state of 
 ;affairs described is by no means a rarity, while there can be no question 
 that plenty of examples of slaughter-houses, private, semi-private, or even 
 public, are to be met with, which in site, structure, and in every particular, 
 are unsuited to their purpose, and in no respect are conducted as they should 
 be. Furthermore, it is important to note that it has been due to pressure 
 -from without that these revolting details have been modified, rather than to 
 :any effort on the part of those engaged in the trade to improve its conduct, 
 accommodation of the most meagre description with a minimum of atten- 
 tion satisfying the very modest requirements of many butchers. We learu 
 :an important lesson here. 
 
982 HYGIENE 
 
 It will be observed that the least satisfactory conditions have been, and 
 still are, associated with jjr/raic slaughter-houses, for such an aggregation as 
 has been previously described is not to be regarded as a public abattoir. We 
 shall presently refer to public abattoirs and to the advantages which they 
 present, and in the meantime deal with private slaughter-houses. 
 
 In most towns the proprietors of small slaughter-houses are licensed for 
 a retail business only ; i.e. the licensee is permitted to slaughter only those 
 animals of which he disposes in the course of his ordinary business. A 
 wholesale licence enables him to slaughter for other butchers, and to permit 
 otber butchers to slaugbter on his premises. In both of these instances the 
 places of business are private. At the present time almost every sanitary 
 authority has adopted bye-laws for the control and management of these 
 places. The bye-laws of various districts have a more or less close resem- 
 blance to one another, particulars and details being modified by local customs. 
 Among the oldest and best are those of Liverpool, made in 1849, and acted 
 upon since that time. They are almost identical with the Model Bye-laws 
 of the Local Government Board, and may be taken as the type in common 
 use. They embrace regulations for registering and inspection of slaughter- 
 houses, and for keeping the same in a cleanly and proper state, and for re- 
 moving filth therefrom at least once in every twenty-four hours, and for 
 requiring that they should be provided by the occupier with a sufficient 
 supply of water. 
 
 FIRST 
 
 The Occupier of any Slaughter-house, who shall at any time after the date of the 
 cex-tificate at the foot of his licence, and without the assent in wi'iting of the Borough 
 Engineer, Medical Officer of Health, or Building Surveyor for the time being, make any 
 change or alteration whatsoever, or permit or suffer any change or alteration whatsoever 
 to be made in the Slaughter-house or Building to which such hcence applies in respect ol 
 the drainage of the same ; 
 
 Or 
 
 In respect of the flagging or paving of the same ; 
 
 Or 
 
 In respect of the ventilation of the same ; 
 
 Or 
 
 In respect of the supply of water to the same ; 
 Shall, for each and every such offence, forfeit and pay the sum of Forty Shillings, and 
 the sum of Five Shillings for each and every day, after the first, during which such change 
 or alteration shall be continued and unremedied. 
 
 SECOND 
 
 The Occupier of any Slaughter-house who shall neglect or omit to cause the same to be 
 thoroughly whitewashed with quicklinae to the satisfaction of the Medical Officer of Health 
 for the time being, at least once during the first ten days of each and every month, shall, 
 for such neglect or omission, forfeit and pay the sum of Forty Shillings, and the sum of 
 Five Shillings for each and every day, after the first, during which such neglect and 
 omission shall continue. 
 
 THIRD 
 
 The Occupier of any Slaughter-house who shall erect, build, or construct, or who shall 
 permit or suffer to be erected, built, or constructed, or who shall permit or suffer to be, 
 remain, or continue, within any Slaughter-house, any privy, middenstead, or cesspool, or 
 any opening, access, or communication from such Slaughter-house to any such privy, 
 middenstead, or cesspool, shall, for each and every such offence, forfeit and pay the sum 
 of Forty Shillings, and the sum of Five Shillings for each and every day, after the first, 
 during which such privy, middenstead, or cesspool shall be, remain, or continue, within 
 such Slaughter-house, or during which any such opening, access, or communication shall 
 be, remain, or continue, from such Slaughter-house to such privy, middenstead, or cesspool. 
 
 rOUETH 
 
 The Occupier of any Slaughter-house who shall keep, or feed, or permit or suffer to be- 
 kept or fed, within such Slaughter-house, any swine, fowls, or other animals whatsoever,. 
 
SLAUGHTEB-HOUSES AND THEIR ADMINISTBATION 983 
 
 used for human food, save and except such cattle as shall from time to time be brought 
 to such Slaughter-house for the purpose of being there slaughtered, shall, for every such 
 offence, forfeit and pay the sum of Forty Shillings, and the sum of Fwe Shillings for 
 each and every day, after the first, during v/hich such sv/ine, fowl, or other animal shall 
 remain and continue in such Slaughter-house. 
 
 The Occupier of any Slaughter-house who shall keep or retain, or permit or suffer to be 
 kept or retained therein, any cattle for a longer period of time than seventy-two hours 
 previous to the slaughtering of the same, shall, for each and every such offence, forfeit 
 and pay the sum of Forty Shilli/ngs. 
 
 SIXTH 
 
 The Occupier of any Slaughter-house who shall neglect or omit to cause the same to be 
 thoroughly washed and cleansed within three hours after the completion of the slaughter- 
 ing and dressing of any cattle therein, on any day during which any such slaughtering or 
 dressing shall take place, shall, for each and every such offence, forfeit and pay the sum 
 of Forty Shillings. 
 
 SEVENTH 
 
 Every Occupier of a Slaughter-house shall provide, keep, and from time to time main- 
 tain a sufficient number of tubs, boxes, or vessels, with tight or close-fitting covers thereto, 
 constructed to the satisfaction of the engineer for the time being, for the purpose of re- 
 ceiving and conveying away from such Slaughter-house all manure, garbage, offal, and 
 filth ; and shall, immediately after the killing and dressing of any cattle in such Slaughter- 
 house, cause all such manure, garbage, offal, and filth to be placed in such tubs, boxes, or 
 vessels, and to be removed beyond the limits of the Borough of Liverpool, at least once 
 during every day, to the satisfaction of the Medical Officer of Health for the time being ; 
 and any Occupier of a Slaughter-house who shall neglect or omit to provide, keep, or 
 from time to time to maintain such number of such tubs, boxes, or vessels ; 
 Or 
 Who shall neglect or omit to cause such manure, garbage, offal, and filth to be 
 placed therein and removed in the manner, at the times, and beyond the limits 
 aforesaid ; 
 Or 
 Who shall neglect or omit to cause such tubs, boxes, or vessels, after being used for 
 the purpose of such removal, to be thoroughly cleansed and purified before the 
 same are again brought within the limits of the said Borough, 
 Shall, for each and every such offence, forfeit and pay the sum of Forty Shillings, and 
 the sum of Five Shillings for each and every day, after the first, during which such neglect 
 or omission shall continue. 
 
 EIGHTH 
 
 The occupier of any Slaughter-house who shall slaughter, or permit or suffer to be 
 slaughtered therein, any diseased or unsound cattle, shall, for each and every such offence, 
 forfeit and pay the sum of Forty Shillings. 
 
 The occupier of any Slaughter-house who shall, in case of any diseased or unsound 
 cattle being brought to his or her Slaughter-house, neglect or omit forthwith to give infor- 
 mation to the Inspector of Nuisances, at his Office, in the Public Offices, Cornwallis Street, 
 in the said Borough of Liverpool, of such diseased or unsound cattle having been so 
 brought to such Slaughter-house, shall, for every such neglect or omission, forfeit and pay 
 the sum of Forty Shillings. 
 
 TENTH 
 
 The Occupier of any Slaughter-house who shall neglect or omit to remove, or cause to 
 be removed from such Slaughter-house, the blood, hides, and skins of any cattle that 
 shall be slaughtered in such Slaughter-house, within two days next after such cattle shall 
 have been slaughtered, shall, for every such neglect or omission, forfeit and pay the sum 
 of Forty Shillings, and the sum of Five Shillings for each and every day, after the first, 
 during which such neglect or omission shall continue. 
 
 ELEVENTH 
 
 The Occupier of every Slaughter-house shall keep, or cause to be kept therein, a book, 
 in which shall be entered the number and description of all cattle slaughtered therein, 
 together with the name and address of the owner of such cattle, or of the person bringing 
 
984 HYGIENE 
 
 such cattle to the said Slaughter-house ; and shall, on Monday in each and every week, 
 deliver or transmit to the Inspector of Nuisances for the time being, at his said office, a 
 correct transcript copy or duplicate, signed by him, of all entries made in such book during 
 the preceding week, and shall, at any and all times, on being requested so to do by the 
 said Inspector of Nuisances, or any other officer of the said Council thereto authorised by 
 the said Council, produce and show to the said Inspector, or other officer, the said book ; 
 and any occupier of a Slaughter-house who shall neglect or omit- 
 To keep, or cause to be kept, such book ; 
 Or 
 
 To enter, or cause to be entered therein, the number and description of any cattle 
 slaughtered in such Slaughter-house, or the name or address of the owner of such 
 cattle, or of the person bringing such cattle to the said Slaughter-house ; 
 Or 
 
 To deliver or transmit such transcript copy or duplicate in manner and at the times 
 aforesaid, 
 Or 
 
 To produce and show such book to the persons, at the times and in manner afore- 
 said, 
 Shall, for every such neglect or omission, forfeit and pay the sum of Forty Shillings, and 
 the sum of Five Shillings for each and every day, after the first, during which such 
 neglect or omission shall continue. And any person who shall make, or cause, or procure, 
 or permit to be made any false entry in such book, or in such transcript copy or duplicate, 
 concerning any of the matters or things hereby required to be entered or stated in such 
 book or in such transcript copy or duplicate, shall, for each and every such offence, 
 forfeit and pay the sum of Forty Shillings. 
 
 TWELFTH 
 
 Every Occupier of a Slaughter-house shall, on request by the Borough Engineer, 
 Medical Officer of Health, or other authorised Officer of the said Council for the time 
 being, forthwith cause all repairs in or concerning such Slaughter-house which he shall 
 be required, by such request as aforesaid, to perform, to be done and executed to the 
 satisfaction of the Borough Engineer, Medical Officer of Health, or other authorised 
 Officer of the said Council for the time being ; and any Occupier of a Slaughter-house 
 who shall, for the space of one week after such request as aforesaid, refuse or neglect to 
 cause such repairs to be so done and executed as aforesaid, shall, for such refusal or 
 neglect, forfeit and pay the sum of Forty Shillings, and the sum of Five Shillings for 
 each and every day, after the first, during which such refusal or neglect shall continue. 
 
 THIETEENTH 
 
 Any Occupier of a Slaughter-house who shall keep, or permit, or suffer to be kept, 
 within such Slaughter-house, any dog,' without the same being well and sufficiently 
 chained, fastened, and secured, shall, for every such offence, forfeit and pay the sum of 
 Forty Shillings, and the sum of Five Shillings for each and every day, after the first, during 
 which such dog shall be so kept. 
 
 FOURTEENTH 
 
 The Occupier of every licensed or registered Slaughter-house shall cause the word 
 ' Slaughter-house,' together with the number corresponding with the number of his licence 
 or register, as the occupier of such Slaughter-house, as the same shall from time to time 
 appear on the register of such licences, kept under the directions of the said Council, to 
 be painted or otherwise inscribed, to the satisfaction of the Inspector of Nuisances for the 
 time being, on, over, or adjoining to the outside of the door or entrances to such Slaughter- 
 house, and kept and continued there not obliterated or defaced ; and any Occupier of a 
 
 ' ' A dog harbours a tsenia, and this parts with its last joint (proglottis) containing ripe 
 eggs, or departs in person from the intestine. The proglottis or tffinia may fall to the 
 ground entire, \vith all the eggs in it, or the eggs may be laid by the proglottis already in 
 the intestinal canal, and leave it in separate clusters mixed with faces. These are now 
 eaten by cattle or man wth their respective raw or uncooked food. Arrived in the intestine, 
 they are developed into embryos, which penetrate into the organs of the abdominal cavity 
 and the chest, and are there developed into the cystic forms of echinococci.' ' The echino- 
 cocci of cattle, particularly of sheep, are set free in the process of slaughtering ; these are 
 thrown on the ground and devoured by dogs, in them again to grow into ripe tienia.' 
 (Dr. Thudichum on ' Parasitic Diseases of Quadrupeds used for Food by Man,' in the 
 Seventh Report of the Medical Officer of the Frivy Council.) 
 
SLAUGHTEB-HOUSES AND THEIR ADMINISTBATION 98/> 
 
 Slaughter-house who shall neglect or omit so to do shall, for each neglect or omission, 
 forfeit and pay the sum of Forty Shillings, and the further sum of Five Shillings for 
 each and every day, after the first, during which such neglect or omission shall continue. 
 
 FIFTEENTH 
 
 The Occupier of every Slaughter-houae shall cause a copy of these Bye-Laws, written 
 •or printed in large characters, to be affixed in some conspicuous place in such Slaughter- 
 house, to the satisfaction of the Inspector of Nuisances for the time being, and to be at all 
 times kept and continued there not obliterated or defaced. And any occupier of a 
 Slaughter-house who shall neglect or omit to cause such copy to be so affixed, kept, and 
 continued, shall, for such offence, forfeit and pay the sum of Forty Shillings, and the 
 sum of Five Shillings for each and every day, after the first, during which such neglect or 
 •omission shall continue. 
 
 The following is the form of licence held by the proprietors of the few 
 private slaughter-houses allowed within the city of Liverpool, and it may be 
 taken as the standard form employed throughout the country. No licence 
 has been granted in Liverpool since 1877 : — 
 
 City of Liverpool, to wit. 
 
 Wheeeas, by an Act passed in the Session of Parliament held in the ninth and tenth 
 years of the reign of her Majesty Queen Victoria, intituled 'An Act for the Improvement 
 •of the Sewerage and Drainage of the Borough of Liverpool, and for making further Pro- 
 visions for the Sanitary Eegulation of the said Borough,' it was, amongst other things, 
 enacted, that any person who should, within the Parish of Liverpool, kill or dress, for the 
 purpose of trade, or cause or permit to be killed or dressed for such purpose, any Cattle, 
 elsewhere than in certain Slaughter-houses erected as therein mentioned under the 
 powers and authorities of a certain Act passed in the twenty-sixth year of the reign of his 
 late Majesty King George the Third, or in a place erected or used for a Slaughter-house, 
 under a licence for that purpose, granted by the Council of the said City, under the 
 authority of a certain Act therein recited, for the Improvement, good Government, and 
 Police Eegulation of the City of Liverpool, and in force at the time of the killing or dress- 
 ing of such Cattle, should, for every such offence, forfeit and pay a sum not exceeding 
 Five Pounds, and the like penalty for every day after the first upon which such offence 
 should be continued. 
 
 And whekeas application hath been made to the Council, by of 
 
 Eetail Butcher, for a Licence for the killing and dressing of Cattle, in 
 situate at within the Parish of Liverpool. 
 
 Now, the Council of the said City of Liverpool do, by these presents, grant a Licence 
 to the said for the killing of Cattle, within the Parish of Liverpool, that 
 
 is to say, within such part of the City of Liverpool as is comprised within the City, as the 
 same was limited prior to the passing of an Act passed in the Session of Parliament held 
 in the fifth and sixth years of the reign of his late Majesty King William the Fourth, and 
 intituled 'An Act to provide for the Eegulation of Municipal Corporations in England and 
 Wales,' under the conditions, restrictions, and regulations following, that is to say, 
 
 1st. The said shall not kill or dress, or permit or suffer to be 
 
 killed or dressed, any Cattle elsewhere, within the said Parish of Liverpool, than in the 
 said 
 
 2nd. The said shall not kill or dress, or permit or suffer to be killed 
 
 or dressed at, or in the said Slaughter-house, any Cattle, except for sale in his shop to his 
 ordinary customers, or to shipping, or for some other similar retail Butcher, who shall be 
 Licensed by or under the direction of the Council. 
 
 3rd. If the said shall commit any breach of the said two herein- 
 
 before mentioned conditions, or of either of them, this Licence shall thereupon forthwith 
 become and be void, and of no effect. 
 
 4th. If the said shall be convicted of any offence within the City of 
 
 Liverpool, against any of the provisions of any Act of Parliament, or of any Bye-law in 
 relation to Slaughter-houses, or to the killing or dressing of Cattle within the said City, 
 then, and in such case, this Licence shall, by any resolution of the Council to determine 
 and make void the same, be and become void, on the expiration of one calendar month 
 after service on the said of a notice in wi'iting, of such resolution. 
 
 5th. This Licence shall, by any resolution of the Council to determine and make void 
 the same, be and become determined and absolutely void, on the expiration of three 
 
986 HYGIENE 
 
 calenilar months after service on the said of a notice, in >vriting, or of 
 
 such resolution, as last aforesaid. 
 
 6th. The service of such notice, as is mentioned in the said 4th and oth conditions 
 respectively, shall be, either by the delivery of a Copy thereof to the said 
 personally, or by leaving a Copy thei'eof at his Dwelling-house, or last known place of 
 abode, within the City, or by affixing the same on the outside of the said 
 
 7th. This Licence shall not be of any effect until the Certificate at the foot thereof 
 shall have been signed by the Medical Officer of Health of the said City for the time 
 being. , Town Clekk. 
 
 I licrchy Certify tlmt the in tJiis Licence meiitioned 
 
 is in a fit and proper state aiul condition for the killing and dressing of Cattle tlierein. 
 
 Liverpool, the day of 18 . 
 
 Eegistered No. . , Medical Officer of Health. 
 
 In London at the present time the requirements for private slaughter- 
 houses are much greater under the London County Council than formerly. 
 Overcrowding is prevented by insisting on 2-i square feet of floor space 
 in every pound for cattle, 8 square feet for calves, and G square feet for 
 sheep, lambs, and pigs ; and every animal must be ' provided with a suf- 
 ficient quantity of wholesome water and food.' The bye-laws of the 
 Council also contain provisions prohibiting the slaughtering of cattle in the 
 public view, or in view of any other animal, and requiring the taking of 
 precautions to prevent unnecessary suffering to the animal slaughtered. The 
 usual pro^dsions relating to the use of receptacles for the refuse products, the 
 removal from the premises of these products, of the hides, tripes, and offal, 
 and the cleansing of the premises and receptacles, are embodied in the bye- 
 laws. Some of the more important requirements relate to the structure of 
 the premises. The entrance or approach to every slaughter-house must 
 be not less than 3 feet 6 inches wide, and the approach must not be up or 
 down steps, nor over a steeper gradient than one in four. The entrance or 
 approach to slaughter-houses for sheep, lambs, and pigs only, need not have 
 a greater width than 2 feet 9 inches. The bye-laws also require the proper 
 lighting, ventilation, paving, and drainage of every slaughter-house, pound, 
 pen, and lair, and the provision of water supply, water fittings, and wall 
 coverings ; no room over a slaughter-house may be used for human habitation, 
 nor may any water-closet, pri\7, urinal, or stable be in direct communica- 
 tion with, or ventilate into, a slaughter-house. The requirements for new 
 slaughter-houses are still greater. The slaughter-house and its poundage 
 must be at least 20 feet from any inhabited building, and must not have any 
 entrance opening directly on a public highway. Every slaughter-house must 
 have an adequate place for the accommodation or poundage of the cattle 
 about to be slaughtered, with an entrance way for the cattle otherwise than 
 through the slaughter-house ; and the slaughter-house and its poundage must 
 have an entrance apart from, and independent of, any shop and dwelling- 
 house, and be properly lighted by lantern, sky, or side lights. The floor 
 of the premises must not be below the level of the outside road or footway. 
 
 However excellent the construction of bye-laws may be, no profound ex- 
 perience or knowledge of the world is needed to show that the amount of 
 attention paid to their requirements, and consequently the amount of good 
 they are, will depend upon the stringency with which their provisions are en- 
 forced. Without active supervision, the slaughtering places of a town possessed 
 of unimpeachable bye-laws will become centres of offence and a menace to 
 the health of the locality ; not only so, but they may furnish a ready means 
 for the disposal of meat which is unfit for human food ; but before referring 
 to the question of inspection, the important subject of pubhc abattoirs may- 
 be considered. 
 
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SLAUGHTER-HOUSES AND THEIR ADMINISTRATION 987 
 
 Many towns, such, for example, as Huddersfiold, Edinburgh, Manchester, 
 Liverpool, Swansea, and other places, are possessed of public abattoirs, some 
 of them being of recent construction, and others erected some twenty or 
 thirty years back. Generally speaking, these places have been estabhshed 
 in order to remove the evil which resulted from the number, and the then 
 condition, of the private slaughter-houses in those towns. It was no doubt 
 fully recognised that whatever steps may be taken to improve the health of a 
 town by cleansing, scavenging, sewering and the like, they will be rendered 
 ineffectual if slaughter-houses and the attendant and collateral trades are 
 allowed to continue in densely populated quarters, and, as is commonly 
 the case, in the narrowest and most ill- ventilated streets of those quarters. 
 Consequently the aim appears to have been to limit the number of these 
 places to the actual requirements of the people, and, as circumstances 
 permitted, to effect their removal, and the transference of the business to 
 more suitable surroundings. 
 
 The importance of an open site, where the various offensive emanations 
 may be freely diluted with abundance of fresh air, cannot be too strongly 
 insisted upon ; and, when such a site is available, care must be taken to 
 prevent, or at least control, the erection of dwellings adjacent to the slaughter- 
 ing places ; for we find that the abattoirs of several towns, those more es- 
 pecially which were established some twenty or thirty years ago, have been 
 surrounded by dwellings, which in course of years have encroached upon 
 what were originally open sites. As a consequence of this, the removal of 
 public abattoirs sometimes becomes a matter for serious consideration, and, 
 needless to say, it is a question less easy of solution than is the dealing with 
 the smaller interests of a private slaughter-house. It may be remarked that 
 the argument has been put forward against the removal of these places, 
 that the transfer of carcases to any considerable distance, e.g. by rail, has a 
 prejudicial effect upon the meat ; but this is incorrect : indeed, the condition 
 in which meat arrives from the United States or distant colonies, after 
 thousands of miles of travel, provided due care is taken in packing and 
 unpacking, sufficiently disposes of the objection. 
 
 The selection of a site would be further influenced by the facilities afforded 
 for bringing cattle to it, and again by the means available for the removal and 
 distribution of the meat. Consideration would also be given to the conveniences 
 for dealing with hides, blood, intestines, and the like, and for such treatment 
 of these and other products as it may be desirable to adopt. 
 
 The site to be preferred, then, would be one sufficiently removed fi-om dwel- 
 lings to ensure that all offensive vapours, whether from the animals themselves^ 
 or from blood, garbage, or the decompositions of washings and the like, should 
 have abundance of fresh air for their dilution ; it should include a sufficient 
 number of acres, not only to meet present requirements, but to admit of ex- 
 tension of the premises as the population of the district increases and the 
 trade expands ; it should be ready of access, and, if the meat is intended for 
 consumption in distant parts of the country, within easy reach of a railway. 
 
 The general plan of the arrangement of the various components of the 
 business is simple. (See diagram, Plate VIII.) The cattle market, including 
 lairages and pens for cattle, sheep, and pigs, would occupy about one-half the 
 area ; the remaining half will be occupied by the abattoirs proper, comprising 
 slaughter-houses, parallel to and in the rear of which will be lairages which 
 are duly separated therefrom, while in front of the slaughtermg-places, and 
 separated from them by a roadway some 12 feet wide, will be the meat market. 
 The meat market may be connected with the slaughtering-booths by overhead 
 meat-beams, the object of the roadway being to facilitate the removal of blood 
 
088 HYGIENE 
 
 and other materials, the meat itself heing most conveniently removed from 
 the opposite side of the meat market. This sketch is of course liable to many 
 modifications. At Swansea, the abattoirs (see Plate IX.) are of stone with local 
 * polled stone ' facing, lined intenially with white glazed bricks to a height of 
 G feet ; above this the rubble-faced wall is white-limed. The floors of the 
 killing houses and cooling rooms are of Wilkinson's patent granite concrete ; 
 but this being found to be sUppery,' in a recent addition ordinary flags have 
 been used with satisfactory results. The floors of the lairs are of blue stable 
 bricks (Doulton's). Provision for artificial lighting is made by gas brackets, 
 so placed as not to interfere with the hoisting and hanging machinery. 
 
 The site is bounded on three sides by streets about 80 yards wide, with no 
 houses or buildings on the sides of the streets next the slaughter-houses. 
 The lairs are only separated from the killing-houses by a passage 6 feet wide, 
 this arrangement being made with a view to get the animals easily from the 
 lairs to the slaughter-houses. The cooling rooms are to a certain extent used 
 as a dead-meat market, the carcases being here sold wholesale and then con- 
 veyed to the retail market about half a mile away. 
 
 The cattle-market adjoins the slaughter-house buildings, and contains 
 lairs for beasts and sheep, and also pig pens, all covered and protected from 
 the weather ; there being no open pens in the market. 
 
 At Huddersfield there is a similar proximity of the abattoir to the cattle 
 market. Both are well situated in an open locality removed from dwellings. 
 The premises are enclosed and are provided with an attractive approach. As 
 in the preceding case, the lairages are appropriately separated from the 
 slaughtering-place, the animals being driven in as required ; the slaughtering- 
 places are merely recessed off from the meat market. The floor is of concrete ; 
 the walls have white glazed bricks to a height of 8 or 9 feet, and there is a 
 good north top light. The piggery, which is separate, is of similar construc- 
 tion, and is provided with steaming apparatus. 
 
 The total area covered by the slaughter-houses, yards, &c., is 7,198 square 
 yards, of which 1,598 square yards are available for future extension. The 
 cattle market covers an area of 1 acre 1 rood 12 perches ; the animals 
 passmg through it last year were 8,438 beasts, 2,263 pigs. At the slaughter- 
 houses during the same period, the number of animals killed was 5,255 
 beasts, 2,524 calves, 13,000 sheep, 5,985 pigs. 
 
 The planning, structure, and administration of these premises are all 
 good. 
 
 At Liverpool, although the management is good, the structure of the 
 older parts of the abattoirs is defective, and the site, though excellent for a 
 meat market, is not all that could be desired for an abattoir. The regulations 
 of the Liverpool Abattoir Company are as follows : — 
 
 1. That the Lairs of the Abattoir Company are only intended for the acconmiodation 
 of animals brought on to the Company's premises for the purpose of being slaughtered 
 there ; therefore, and for the purpose of preventing the spread of Cattle Disease, and the 
 Abattoir being closed by orders of the Privy Council or otherwise, which would cause great 
 loss and inconvenience to the Company and persons using the Abattoir, no Ox, Cow, Bull, 
 Calf, Pig, Sheep, Lamb, or Goat, brought on to the Company's premises, shall be removed 
 therefrom until after it is slaughtered. 
 
 2. That for the more conveniently carrying on the business of the Company, the 
 Directors reserve power of appointing from time to time the most convenient hours for re- 
 ceiving animals, slaughtering, selling dead meat, and doing any other act, matter, or thing, 
 
 3. That during the time from 7 o'clock to 10 o'clock in the mornings of Tuesdays, 
 Wednesdays, and Thursdays, and during the time from 4 o'clock to 6 o'clock in the after- 
 
 ' Generally speaking, slipperiness can be overcome by a judicious sprinkling with saw- 
 dust. 
 
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SLAUGIITEB-HOUSES AND THEIR ADMINISTBATION OSO 
 
 noons of Mondays, Wednesdays, and Thursdays, no Cattle, Calves, or Sheep shall be 
 brought on to the Company's premises except by either of the entrances Nos. 15, in Trow- 
 bridge Street, 16, in Copperas Hill, 19, 20, & 22, in St. Andrew Street, or into the Chapel 
 and the Piggery ; and no cattle shall during the same times be taken out of either of the 
 North-end Lairs in Trowbridge Street or St. Andrew Street. 
 
 4. That the number of animals which may be brought into the Lairs, and from the 
 Lairs or the Street or otherwise, into the slauglitcring-place at one time by any owner, 
 shall be regulated from time to time by the Directors or their Servant or Servants, in such 
 manner as they may deem proper, for preventing overcrowding or inconvenience in the 
 slaughtering-place. 
 
 5. That, except during such times as, in consequence of any Regulation or Order in 
 relation to the prevention of Cattle Disease, the Directors shall otherwise direct, no animal 
 shall be allowed to remain on the Company's premises unslaughtered for more than forty- 
 eight hours. 
 
 6. If any animal is left on the Company's premises for more than forty-eight hours, 
 excejDt when the Directors shall otherwise direct as above-mentioned, and then for more 
 than the time directed, without being slaughtered, the Directors or their servant or servants 
 may cause such animal to be slaughtered, and charge the owner, or person who brought 
 or caused to be brought such animal on to the Company's premises, with all costs, charges, 
 and expenses incurred, in addition to any tolls or other charges ; and may sell all or any 
 part of the carcass, hide, skin, fat, offal, or other part of such animal, and, out of the 
 moneys received therefor, retain and reimburse themselves the costs, charges, and ex- 
 penses of carrying the powers and provisions hereof into effect, and all tolls, charges, and 
 payments owing or payable to the Company by the owner of such animal, or the person 
 or persons who brought or caused to be brought such animal on to the Company's premises 
 or any other person in respect of such animal. 
 
 7. That all Cattle brought on to the Company's premises shall be tied up, and all 
 animals shall be placed in such Lairs, and the slaughtering shall take place, and all 
 carcasses and dead meat shall be hung, and all other parts of the animals shall be deposited, 
 where and as the Directors or their servant or servants shall from time to time direct, as 
 most conducive to the carrying on of the business of the Company and the convenience 
 of the persons resorting to their premises. 
 
 8. That what are known as smothered animals shall (if fit for human food) be dressed 
 as soon as possible after arriving at the Company's premises ; and the several Bye-Laws, 
 Eules, and Eegulations shall (as far as applicable) be applied to such animals and their 
 products, as if they had been slaughtered on the Company's premises. 
 
 9. Complaints have been made to the Directors of Cattle and other animals being 
 kept on their premises an unreasonable time, without food and water ; therefore, 
 no animal shall be kept on their premises more than twenty-four hours without being 
 fed and watered. 
 
 10. There shall be paid to the Company, in respect of animals slaughtered on the 
 Company's premises, the following tolls or payments, viz. : — 
 
 for each Ox, Cow, or Bull Is. 6^. 
 
 for each Sheep, Lamb, or Goat l\d. 
 
 and for each Calf or Pig Qd. 
 
 and there shall be paid to the Company, in respect of every carcass brought on to the 
 Company's premises but not slaughtered thereon, the following tolls or payments, viz. : — 
 
 of an Ox, Cow, or Bull Is. &d. 
 
 of a Sheep, Lamb, or Goat l^d. 
 
 of a Calf or Pig Qd. 
 
 and for all dead meat in pieces less than a carcass, such sum as the Directors or their 
 servants shall decide is a fair and just payment, in proportion to what is payable in 
 respect of a carcass. 
 
 11. There shall be paid to the Company, in such cases as the Directors or their 
 servants shall think fit to enforce the same, in respect of 
 
 each Ox, Cow, or Bull 3d. 
 
 each 20 Sheep, Lambs, or Goats Is. 
 
 and a proportionate amount for any smaller number ; 
 
 each Calf 3d. 
 
 and each Pig l\d. 
 
990 HYGIENE 
 
 for every twentj'-four hours, or less time than twenty-four hours, beyond the first forty- 
 eight hours, during which such animal shall remain on the Company's premises un- 
 slaughtered. 
 
 12. That if any animal shall be sold while alive and on the Company's premises, there 
 shall be paid to the Company, in addition to all other tolls, rates, and charges, the sum 
 
 of 
 
 for each head of Cattle <>"• 
 
 for each 20 Sheep, Lambs, or Goats . . . .Is. 
 
 and a proportionate amount for any smaller quantity ; 
 
 for each Calf 3d. 
 
 for each Tig la^- 
 
 so sold. 
 
 13. Every person who shall slaughter, or cause to be slaughtered, any animal in or 
 upon the premises of the Company, shall carefully collect or cause to be collected the 
 blood flowing therefrom, in the utensil provided for that purpose by the Directors. 
 
 14. That every person so slaughtering, or causing to be slaughtered, as aforesaid, 
 shall deposit and leave in such place or places on the premises as the Directors or their 
 servant or servants shall from time to time direct, the Garbage, Gall, Blood, Intestines, 
 Manifolds, Slinks, Pig's Hair, Eops, Sheep's Bellies, Bladders, and Manure produced 
 from each animal slaughtered, excepting the Blood and Eops of Pigs. 
 
 15. That the Blood, Garbage, and other matters mentioned in the 14th Bye-Law, 
 Regulation, or Eule shall be the property of the Company, and the same shall absolutely 
 pass to and vest in the Company. 
 
 16. All former Bye-Laws, Eules and Eegulations, made and issued by the Directors 
 are withdrawn, and have ceased to take effect, except in respect to any act, matters, 
 rights, duties, and liabilities before the making of these Bye-Laws, Eules and Eegulations, 
 
 17. That each slaughterer shall, immediately after any slaughtering takes place, well 
 and effectually sweep, wash, and cleanse the place used. 
 
 18. The Company will not be liable for the safe custody of any animal, dead meat, or 
 other part of any animal, or any damage or injury to any animal, or dead meat, or other 
 part of any animal, whilst on the Company's premises ; and, for the purpose of this rule, 
 the respective owners of animals, and dead meat, or parts of any animal, shall be deemed 
 and considered to have the sole custody, care, and preservation of the same. 
 
 19. Any person making a false return to any of the Company's servants, of their 
 weekly or other slaughter, will not be allowed to slaughter any more on any part of the 
 Company's premises, or to bring thereon any animal, carcass, or part of any animal. 
 
 20. That the Company shall have a general lien on all live and dead animals, dead 
 meat and parts of animals, for all moneys owing or payable to the Company in respect 
 thereof by any person or persons whomsoever, and shall be entitled to enforce such lien by 
 seizure and sale, without any further authority. 
 
 21. AU persons while upon the Company's premises shall obey the orders of the 
 Directors and their servant or servants, and shall behave in an orderly and proper manner, 
 and shall attend to and conduct their business therein in such a way as not to cause 
 annoyance or obstruction to any other person. 
 
 22. No person who has not proper and sufficient business to be on — or who shall not, 
 on request, satisfy the Directors or their servant or servants that he has proper and 
 sufficient business to be on— the premises, shall be or remain on the premises of the 
 Company ; and the Directors or their servant or servants shaU be at liberty to forcibly 
 eject from their premises all persons who do not, on request, satisfy them that they have 
 proper and sufficient business to be on the premises. 
 
 23. The Directors, their servant or servants, shall be at liberty to forcibly eject from, 
 and prevent from again coming on to the premises, any person who shall not observe, 
 comply with, and conform to these Bye-Laws and Eules. 
 
 24. All dogs on the Company's premises during the time from 7 o'clock to 10 o'clock 
 in the mornings of Tuesdays, Wednesdays, and Thursdays, and during the time from 4 
 o'clock to 6 o'clock in the afternoons of Mondays, Wednesdays, and Thursdays, and on 
 Fridays, from 7 a.m. to 5 p.m., belonging to any person having animals, carcasses, or other 
 dead meat, or to the servants of such persons, shall be securely chained, tied up, or other- 
 ^vlse confined, so that they may not cause annoyance or inconvenience to persons having 
 business on the Company's premises. 
 
 Something more than a general impression with regard to the relative 
 advantages of public and private slaughter-houses will have been derived from 
 
SLAUGHTEB-HOUSES AND TEE IB ADMINISTBATION 991 
 
 the foregoing pages. If slaughtering and its attendant industries are offensive 
 or hable to become so, or are of such a nature as to require jealous watching 
 and careful administration to prevent them becoming injurious to health, it 
 is clearly desirable to minimise the numbers of such establishments to the 
 necessities of the trade. Furthermore, practical experience confirms the view 
 that more economy and greater efficiency are found by centralising the trade 
 in one well-conducted establishment, than can be looked for when every butcher 
 slaughters in his own more or less ill-adapted back premises at irregular 
 intervals to meet the requirements of a small retail trade. Again, the diffi- 
 culties in the way of inspection, and the prevention of the sale of unsound 
 meat, are greatly increased when supervision has to be extended to a multitude 
 of small out-of-the way places, numbering as they do in one important town 
 as many as 40, in another as many as GO, and in a third upwards of 200. 
 Such conditions afford facilities for the disposal of unsound meat which are 
 practically beyond the control of inspectors ; and indeed the position in these 
 cases is frequently still further complicated by the practice of licensing 
 several retail butchers to kill on the same premises, thus putting still further 
 obstacles in the way of fixing responsibility and preventing improper conduct. 
 With the prompt and multiplied means of transit now available, there no 
 longer exists any necessity for private slaughter-houses in towns, and it may 
 be hoped that the establishment in their place of public abattoirs upon 
 salubrious sites is merely a question of time. 
 
 We come now to the work of inspection, the objects of which are twofold, 
 viz. (1) to insure that meat intended for the food of man shall be in good and 
 wholesome condition, and (2) to provide for the observance of the bye-laws 
 and the proper conduct of the business. The powers exercised by sanitary 
 authorities are derived from several sources — viz. various local Acts, and bye- 
 laws based upon them ; the Contagious Diseases (Animals) Acts, and Orders 
 of Council made thereunder ; and the Public Health Act. 
 
 Public abattoirs will require the presence of the inspector, at least several 
 hours a day if an extensive business is carried on. Visits should, of course, 
 ■also be paid at irregular intervals. All private slaughter-houses should be 
 visited at least once a day, oftener if the business is a large one. The twenty- 
 eight private slaughter-houses in Liverpool are visited, some daily, others two 
 or three times a day. As an index to the extent of business needing this 
 supervision, it may be stated that the number of animals killed in these private 
 slaughter-houses during the year amounted to 10,500 cattle, 45,000 sheep, 
 3,000 calves, and 48,000 pigs. At the public abattoirs the numbers killed 
 in the same period were, 29,841 cattle, 192,000 sheep, 17,096 calves, and 
 22,000 pigs ; large quantities of imported dead meat were also sold at these 
 premises. In regard to the method of meat inspection pursued in Liverpool, 
 the services of the Medical Officer of Health, his deputy, and the veterinary 
 superintendent are all available when required, and in addition there are six 
 meat inspectors, each of whom has a separate district and specific duties 
 allotted to him, and is invested with authority, in conformity with the require- 
 ments of the several Acts already referred to. These inspectors are selected 
 with great care from men physically fit, of unquestionable character, and with 
 practical experience as butchers acquired in the public abattoirs, and are 
 required to give proof of a thorough acquaintance with all classes of meat 
 before undertaking the duties of inspector. Their salaries range from 120Z. 
 to 225L per annum. 
 
 The officers of the Corporation exercise no control over meat in transit ; 
 and their responsibihty is limited to animals slaughtered, or meat brought for 
 sale within the city, whether intended for consumption within the mimicipal 
 
992 HYGIENE 
 
 boundary or not. It is almost unnecessary to remark that the mere presence 
 of diseased meat upon licensed premises does not necessarily constitute a 
 ground for prosecution ; for, on the one hand, diseased animals are not 
 infrequently sent to these places for convenience of slaughter and removal 
 of the hides, &c. ; and on the other hand, disease, such as cysticcrcus, which 
 renders an animal unfit for food, may be incapable of detection during life, 
 and be only ascertainable when the animal undergoes the process of dressing. 
 In cases such as these, it is the duty of the person who is in possession of the 
 carcase to remove it to some specified part of his premises, away from the 
 place where meat is usually sold or deposited for the purpose of sale ; the 
 inspector then calls a jury of three members of the trade, who, with the 
 owner, agreeing as to the condition of the meat, sign a certificate to that 
 effect, and the meat is destroyed ; no magistrate's order being necessary in 
 these cases. A small fee is paid to the jurors who view the meat. 
 
 For reasons which are sufficiently obvious, it is preferable that suspected 
 animals should be sent to the public abattoirs rather than to private slaughter- 
 houses ; disease existing in animals killed at the former place probably never 
 escapes detection, and the chances of unwholesome meat being removed 
 therefrom for consumption are practically nil. 
 
 With regard to the very different class of cases in which attempts are 
 knowingly and intentionally made to dispose of unsound meat for human 
 food, it is well to emphasise the provisions of sections IIG, 117, 118, 119 of 
 the Public Health Act, which enable the Medical Officer of Health or Inspec- 
 tor to examine any meat exposed for sale and intended for the food of man, 
 the onus of proof that it loas not so intended lying tvith the party charged ; 
 and the Act provides that, if such meat appear unfit for the food of man, the 
 officer may seize the same in order to have it dealt with by a justice. It will 
 be noted that the Act does not convert the Medical Officer or Inspector into 
 an arbitrator whose function it shall be to advise dealers in meat what is 
 sound and what is unsound, what may be exposed for sale and what may 
 not, but it assumes that the dealer has a competent knowledge of his trade 
 and merely directs the officer to seize what in his opinion is unsound, and 
 have the matter decided by the magistrate. 
 
INDEX 
 
 ABA 
 
 Abattoibs, public, arrangements for, 987 
 
 inspection of, 991 
 
 ABC process for precipitation of sewage, 
 
 866 
 Acids, vegetable, as foods, 396 
 Acre, density of population to, as affecting 
 
 health, 656 
 Acts, dealing with housing of working 
 
 classes, 674 
 Adults, relative heights of, under varying 
 
 conditions, 546 
 
 — selection of exercises for, 613 
 Affusion, cold, as an antipyretic, 632 
 Age as influencing choice of diet, 407 
 Agricultural labourers, dwellings for, 676 
 Air, amount of carbon dioxide in, 3, 9, 23, 
 
 44 
 
 — oxygen in, 3 
 
 required for ventilation, 13, 18, 
 
 116 
 
 in hospitals, 20 
 
 schools, 21 
 
 — bacteria in, 5, 28 
 
 — carbon dioxide as a standard of impurity 
 of, 17 
 
 estimation of, in, 23 
 
 — chemical analysis of, 23 
 
 — composition of, 3 
 
 — condition of, as influencing evaporation, 
 47 
 
 — diseases associated with impurities in, 9 
 produced by impurities in, 6 
 
 — distribution of heat by, 131 
 
 — dust and smoke in, 48 
 
 in, essential to formation of fogs, 47 
 
 — dynamical cooling of, 42 
 
 — effect of current of, in producing evapo- 
 ration, 47 
 
 — estimation of free and albuminoid am- 
 monia in, 27 
 
 hygrometric condition of, 28 
 
 ■ — oxidisable substances in, 26 
 
 — examination of, 22 
 micro-organisms in, 28 
 
 — excessive humidity of, in factories, 10 
 
 — filtration of , 51 
 
 — flow of, through room with open fire, 98 
 
 — gaseous matters in, 9 
 
 — hydrogen sulphide in, 10 
 
 — impurities in, 4, 13, 49 
 
 derived from walls and floors, 16 
 
 — detection of, 16 
 
 VOL. I. 
 
 ALC 
 
 Air, impurity of, in connection with plague 
 and pestilence, 651 
 
 — law of continuity of flow of, 53 
 
 — local circulation of, 85 
 
 — metallic dust and fumes in, as causes of 
 disease, 7 
 
 — motion of, through tubes and apertures, 
 52,55 
 
 — of brickfields, 12 
 graveyards, 12 
 
 — — marshes, 13 
 
 sewers, composition of, 840 
 
 — organic effluvia in, 10 
 suspended matters in, 5 
 
 — organised bodies in, 8 
 
 — ozone in, 4 
 
 — physical properties of, 41 
 
 — purity of, a condition of healthfulness 
 of dwellings, 651 
 
 — quality of, for efficient respiration, 117 
 
 — respired, aqueous vapour in, 14 
 
 carbon dioxide in, 14 
 
 organic matter in, 15 
 
 — saturation of, by moisture, 45 
 
 — space, cubic measurement of, 21 
 
 — suspended matters in, 4, 6, 44 
 
 — vitiated by combustion, 15 
 
 exhalations from the sick, 11 
 
 gas combustion, 11 
 
 heating apparatus, 118 
 
 perspiration, 15 
 
 respiration, 10, 13 
 
 sewage emanations, 11 
 
 — watery vapour in, 4, 44 
 
 — weight of cubic foot of, 41 
 
 Airy, Dr., on circumstances favouring 
 
 prevalence of diphtheria, 337 
 AiTEEN, Mr., on dust and smoke in air, 47 
 
 effect of electricity on dusty air, 51 
 
 Albuminoid ammonia in water, 286 
 Albuminoids as food, 398 
 
 — change of, in body, 396 
 Albuminuria as a result of sudden change 
 
 of climate, 220 
 Albumoses as food, 394 
 Alcohol, action of, on central nervous 
 
 system, 485 
 
 digestive system, 477, 484 
 
 heart, 484 
 
 temperature, 484 
 
 — dietetic use of, 487 
 
 — physiological action of, 483 
 
 3 s 
 
994 
 
 HYGIENE 
 
 ALC 
 
 Alcohol, symptoms and changes produced 
 
 by excess of, 485 
 Alcoholic beverages, 480 
 
 classification and composition of, 481 
 
 physiological action of, 486 
 
 — preparations, poisonous action of various 
 kinds of, 486 
 
 Algeria and Morocco, climates of, 212 
 Alkaloids, beverages containing, 488 
 Alum, use of, to adulterate bread, 464 
 
 precipitate sewage, 858 
 
 Amines, process for dealing with sewage, 
 
 868 
 Ammoniacal vapours in air, 10 
 Amputations, statistics of, before and after 
 
 Listerism, 798 
 Analyses of water, standard solutions for, 
 
 295 
 Anemometers, forms of, 175 
 
 — use of, in testing ventilation, 104 
 Aneurysm, exercise as a factor in produc- 
 ing, 569 
 
 Animals, nuisances connected with slaugh- 
 tering, 899 
 
 — rules for conveyance of, by water, 978 
 Anstey, Dr., on innocuous amounts of 
 
 alcohol, 484 
 Anthrax, bacillus of, 376 
 
 — meat of animals suffering from, 447, 
 502 
 
 • — methods of propagation of, 930 
 
 — relation of, to soil, 375 
 Anti-scorbutics, 474 
 
 Anti-septicism, results of, in lying-in hos- 
 pitals, 800 
 
 — use of, in General Lying-in Hospital, 
 803 
 
 Antwerp, plan of Civil Hospital at, 737 
 Apparatus, combinations of, for warming 
 and ventilating, 141 
 
 — gymnastic, 599 
 
 Aquatic animals, purification of streams 
 
 by, 265 
 Areas, insanitary, growth of, in towns, 653 
 Arro\^TOot, starch grains of, 452 
 Arsenic in wall papers, mischief caused by, 
 
 8 
 
 — nuisance and danger connected with use 
 of, in industries, 952 
 
 — precautions to be observed by workers 
 in, 953 
 
 Artesian wells, water from, 240 
 
 Artificial lighting, effects of, on ventilation, 
 
 114 
 Artisans, dwellings for, 677 
 Ash closets, 816 
 Asthma, treatment of, by compressed air, 
 
 644 
 Asylums for the insane, 754 
 Atmospheric burners, for use in stoves, 
 
 129 
 
 — pressure, measurement of, 151 
 Attendants, hospital, dresses of, 783 
 Automatic siphon flush tank for subsoil 
 
 irrigation, 888 
 
 Bacillus anthracis, 376, 931 
 
 — tuberculosis, 360 
 
 Bacon, nuisances connected with curing of, 
 934 
 
 BAT 
 
 Bacteria in air, 5 
 
 — influence of, on soil, 313 
 
 — recognition of, in water, 296 
 Ballahd, Dr., on causation of annual mor- 
 tality from diarrhoea, 657 
 
 — - on connection between temperature 
 and diarrhcea, 303 
 
 fatal results from animal food, 
 
 505 
 
 micro-organisms in diarrhoea, 366 
 
 typhoid from contamination of 
 
 milk, 334 
 Baltimore Hospital, ventilation of, 762 
 Bar, horizontal, use of, in gj-mnastics, 602 
 Baraques in German hospitals, 732 
 Bar-bells, use of, in gjTunastics, 601 
 Barley as a food, 464 
 
 Baenham's cowl and Boyle's ventilator, 77 
 Barometers, aneroid, 155 
 
 — daily range of, 158 
 
 — Fortin's and Kew patterns of, 152 
 : — measurements of heights by, 156 
 
 — positions for, 153 
 
 — reading of, 154 
 
 — recording, 156 
 
 ■ — reduction of, to sea-level, 157 
 
 — transport of, 153 
 
 — various kinds of, 152 
 
 Barometric pressure as influencing climate, 
 192 
 
 ventilation, 73 
 
 effects of diminished, 193 
 
 — increased, 194 
 
 Barracks, English, in last century, 697 
 
 — modern arrangements of, 698 
 
 — old French plans of, 696 
 
 — plan of rooms in, 699 
 
 Barky, Dr., on flow required for self-purifi- 
 cation of water, 266 
 Bars, parallel, use of, in gymnastics, 601 
 Basement buildings, dangers to health in, 
 
 331 
 Basins for w.cs., forms of, 664 
 Bassano on telluric origin of tetanus, 373 
 Bastille, description of the (1774), G92 
 Batem.^', Mr., on rainfall available for 
 
 water supply, 232 
 Bath and bathroom, construction of, 645 
 Baths, absorption of substances dissolved 
 in, 628 
 
 — and closets, amounts of water required 
 for, 244 
 
 — bibliography of, 647 
 
 — brine, 643 
 
 — cold, 620 
 
 — — anti-pyi'etic uses of, 631 
 
 efl'ects of, in fever, 620 
 
 on body, 621 
 
 — respiration and circulation, 
 
 622 
 
 cutaneous sensibility, 623 
 
 tissue- waste increased by, 621 
 
 used locally, 624 
 
 — — uses of, 630 
 
 — electric, 645 
 
 — electrical operations of, 629 
 
 — for school children, arrangements for, 
 711 
 
 — forms of, 618 
 
 — history of, 617 
 
 i 
 
INDEX 
 
 995 
 
 BAT 
 
 Baths, hot vapour, or Russian, 640 \ 
 effects and uses of, 641 
 
 — indifferent, 619 ; 
 uses of, 630 
 
 — local hot-air, 640 
 
 — materials for construction of, 646 
 
 — moor, peat, mud, and slime, 643 
 
 — mustard, 643 
 
 — ■ of compressed air, 643 
 
 — diseases treated by, 644 
 
 — outlet pipes for, 647 
 
 — physiological action of, according to 
 constituents, 627 
 
 according to temperature, 619 
 
 — pine leaf, 643 
 
 — Russian (see Baths, hot vapour), 640 
 
 — sand, 643 
 
 — sea, 636 
 
 — Turkish, contra-indications for, 640 
 
 — — description of, 637 
 effects of, 638 
 
 form of, for home use, 640 
 
 uses of, 639 
 
 — uses of, according to constituents, 636 
 temperature, 630 
 
 — various forms of artificial, 642 
 
 — warm, effects of, 625 
 local, 627 
 
 — — uses of, 634 
 
 Beans and peas, digestibility of, 470 
 
 starch-grains of, 452 
 
 Beakd and Rockwell on electric baths, 645 
 
 Beaumont on digestibility of articles in 
 stomach, 419 
 
 Becheb, Dr., on increase of bodily tempera- 
 ture with that of air, 189 
 
 Bedding, hospital, cleaning of, 782 
 
 Beef, sound, characteristics of, 496 
 
 Beef-tea, 449 
 
 Beer, action of, 486 
 
 — composition of, 481 
 
 — effect of, on digestion, 478 
 Beggiatoa alba (sewage fungus), growth of, 
 
 884 
 Bennett, Mr., on causation of varicose 
 
 veins, 570 
 Berlier system of sewage, 850 
 Berlin, Moabit Hospital, plan of, 739 
 Beverages containing alcohol, 480 
 
 alkaloids, 488 
 
 Bichromate of potassium, poisoning by, 953 
 
 Bicycles, forms of, 586 
 
 Biefel and Poleck, analysis of coal-gas, 949 
 
 Biscuits, composition of, 460 
 
 Blackimn's air-propeller, 80 
 
 Blandfoed, Mr., on land and sea breezes, 
 
 198 
 Blood, preparation of, for Turkey red, 906 
 
 — utilisation of, 904 
 
 albumen, manufacture of, 904 
 
 boiling and drying, 906 
 
 manure, 905 
 
 Bltth, Mr. W., on composition of black tea, 
 
 489 
 Boating, adaptability of, 584 
 
 — as an exercise, 580 
 
 Boats, mechanical value of sliding-seats in, 
 
 581 
 Body, development of the, 543 
 
 — method of measuring parts of, 551 
 
 BUT 
 
 Body, normal proportions of, 549 
 
 — rate of growth of, 544 
 Bone, proportion of, to meat, 443 
 
 — -boiling, nuisance caused by, 913 
 Bones and muscles, injuries of, during 
 
 exercise, 570 
 
 — distillation of, dangers connected with, 
 969 
 
 — storage of, causing a nuisance, 923 
 Boots, points to be attended to in, 527 
 BouHiN, M., on lesions after death from 
 
 lightning, 200 
 Bourges, plan of artillery barracks at, 700 
 BowiJiTCH, Dr., on dampness of soil as a 
 
 cause of phthisis, 358 
 BoxALL, Dr., on management of the General 
 
 Lying-in Hospital, HOI 
 Boxing as an exercise, 579 
 Boyle's ventilator and Baknham's cowl, 
 
 77 
 Boys, rate of growth and development of, 
 
 545 
 
 — relative height of, under varying condi- 
 tions, 546 
 
 Bradford, back-to-back houses at, 683 
 
 — fume-cremator in use at, 810 
 
 — regulations for prevention of wool- 
 sorters' disease at, 932 
 
 — sewage treated by electrolysis at, 868 
 Brain-symptoms in lead-poisoning, 961 
 Braxy, meat of animals suffering from, 
 
 503 
 Bread, adulterations of, 464 
 
 — advantages of, as a food, 459 
 
 — aerated (non-fermented), 459 
 
 — alum in, 464 
 
 — chemical composition of, 459 
 
 — examination of, 463 
 
 — manufacture of, 458 
 
 — preservation of, 460 
 
 — whole meal, 457 
 
 — yeast in the manufacture of, 458 
 Breath, impurities in air, due to, 13 
 Breathlessness, as a result of exercise, 560 
 
 — due to excess of COj in blood, 561 
 
 — stages of, 562 
 
 Brickfields, effects of air from, 12 
 
 Brick-making, nuisances arising from, 940 
 
 Bricks, porosity of, 661 
 
 Briegeb on symptoms caused by decom- 
 posing meat, 445 
 
 Brighton, water-supply at, 239 
 
 Bbistowe and Holmes, report on hospital 
 construction, 722 
 
 Bromine, nuisances connected with manu- 
 facture of, 950 
 
 Brunton, Dr. L., on reduction of tempera- 
 ture by alcohol, 484 
 
 Buchanan, Sir G., on epidemic typhus at 
 Greenock (1865), 653 
 
 — on moisture of soil in connection with 
 phthisis, 356, 660 
 
 results of sanitary work, 891 
 
 ventilation of pipe-sewers, 846 
 
 Buckwheat as a food, 468 
 
 Bucquoy, M., on the circulation in workers 
 
 in compressed air, 195 
 Buda-Pesth, epidemics of typhoid at, 835 
 Businesses, offensive and noxious, 899 
 Butter, adulterations of, 437 
 
 3s2 
 
996 
 
 HYGIENE 
 
 BUT 
 
 Butter, artificial, 439 
 
 — composition of, 437 
 
 — examination of, 437 
 
 — foreign fats in, 438 
 
 BuTTERFncLD, Mr., on cottage privies and 
 summer diarvhanx, (iSl 
 
 Cadge, Mr., on prevalence of calculus, 379 
 Caffein, physiological action of, 488 
 Calcium and magnesium, value of, in food, 
 400 
 
 — salt^ of, in water, 259 
 Calculus, causes of, 380 
 
 — deaths from, in England, 379 
 
 — geographical distribution of, 378 
 
 — immunity of Ireland from, 379 
 Calisthenic exercises, 5!)4 
 
 ' Calorie,' meaning of term, 35 
 Cancer as related to conditions of soil, 377 
 Canoeing as an exercise, 585 
 Carbo-hydrates as food, 395, 399 
 Carbon, amount of, in diets, 405 
 
 — dioxide, conditions modifying excretion 
 of, 14 
 
 morbid effects of inhalation of, 945 
 
 treatment of poisoning by, 945 
 
 — disulphide, vapour of, in air, 10 
 
 — — ground air, 318 
 
 — elimination of, increased by exercise, 555 
 Carbonates in the body, sources of, 401 
 Carbonic oxide and carbon dioxide, differ- 
 ences in symptoms of poisoning by, 944 
 
 morbid effects of inhalation of, 939 
 
 treatment of poisoning by, 944 
 
 Carcases of animals, modes of dressing, 497 
 Caenelley and Mackie on estimation of 
 
 oxidisable substances in air, 26 
 Caenelley, Haldane, and Andeeson on 
 
 carbon dioxide in air, 4 
 micro-organisms in air of 
 
 rooms, 16 
 organic matter in expired 
 
 air, 15 
 standard of purity of air, 18, 
 
 21 
 
 — on cost and efficiency of heating and 
 ventilating schools, 142 
 
 — determination of amount of iron in 
 water, 293 
 
 Carpentek, Dr. A., on absence of risk from 
 
 sewage-farms, 12 
 crop of rye grass from sewage- 
 farms, 878 
 Carpet-cleaning, nuisance caused by, 925 
 Caere's apparatus for cooling, 139 
 Cabsten, Dr., on prevention of trichinosis, 
 
 499 
 Caetee, Dr. v., on prevalence of calculus, 
 
 381 
 Catch-water system at sewage-farms, 876 
 Catgut-making, nuisance caused by, 904 
 Catheters, methods of disinfection of, 792 
 Cattle, importation and transport of, 977 
 
 — vessels carrying, 978 
 Cellar dwellings, rules for, 688 
 Cell: on plasvioclnmi malarics, 352 
 Cereals as food, 455 
 
 Cesspools, construction and dangers of, 823 
 
 — Continental systems of, 824 
 
 CLI 
 
 Cesspools, history of, and laws regarding, 822'. 
 
 — pollution of wells by, 823 
 
 — radical objections to, 824 
 Chamrerlain-Pasteur filter, advantages of,. 
 
 254 
 Charcoal closets, 817 
 
 — use of, in filters, 254 
 Cheese, adulterations of, 440 
 
 — as an article of diet, 439 
 
 — bad effects of, 440 
 
 — composition of, 439 
 
 Chenopodium cjiiiiioa as an article of food,. 
 
 469 
 Chest-girth, average, in males, 546 
 
 — exercises tending to develoj), 611 
 
 — importance of full development of, 548 
 
 — increase of, caused by exercise, 548 
 Chestnuts as food, 469 
 
 Childhood, diet requisite for, 407 
 Children, hospitals for, 744 
 
 — management of, in gymnasia, 600 
 
 — rules for physical education of, 606 
 
 — selection of exercises for, 611 
 Chimney flues, size of, for different rooms, 
 
 126 
 Chimneys, points in construction of, 97 
 Chlorine, morbid effects of inhalation of,. 
 
 939, 951 
 
 — in water, estimation of, 278, 304 
 Cholera, Asiatic, in warm climates, 207 
 
 — bacillus of, 344 
 
 — from contamiiration of soil, 339 
 
 — infantum, conditions influencing preva- 
 lence of, 364 
 
 — outbreak of, in Soho, 268 
 
 — practical extinction of, in England, 894 
 
 — propagation of, through water, 267 
 Chromium, dangers to workers in, 953 
 
 — detection of, in water, 294 
 Chezonsczewsky on absorption by the- 
 
 skin, 628 
 Churches, heating surface required for- 
 warming, 137 
 
 — used as hospitals, mortality in, 720 
 Circulation and respiration, effects of cold' 
 
 baths upon, 622 
 Cirro-cumulus and cirro-stratus, 178 
 Cirrus, 177 
 Cisterns, construction of and materials for,. 
 
 247 
 
 — for storage of water in dwellings, 666 
 
 — necessity for regular cleansing of, 667 
 
 — to supply closets, 667 
 
 Civilisation, drawbacks connected with,, 
 
 539 
 Clark, Dr., on testing hardness of water,, 
 
 258 
 process for estimating hardness 
 
 of water, 290 
 Climate, as influenced by atmospheric 
 
 electricity, 199 
 
 barometric pressure, 192, 202 
 
 humidity, 189 
 
 rainfall, 191 
 
 temperature, 188 
 
 winds, 196 
 
 influencing diet, 407 
 
 prevalence of calculus, 380 
 
 — British, 216 
 
 — factors constituting, 188 
 
INDEX 
 
 997 
 
 CLI 
 
 •Climate, influence of, on health, 187 
 ■Climates, classification of, 200, 208 
 
 — cold, 215 
 
 — effects of latitude u^Don, 201 
 ■ — marine, 216 
 
 — mountain, 220 
 
 — of deserts, 210 
 
 — temperate, 213 
 
 diseases prevailing in, 214 
 
 — warm, 203 
 
 diseases prevailing in, 204 
 
 Climbing, apparatus for, in gymnasia, 604 
 Closet accommodation in schools, 712 
 Closets, ashes for use in, 816 
 
 — charcoal, 817 
 
 — construction of, 815 
 
 — earth, 818 
 
 Clothing, absorbent power of, 519 
 
 — ffisthetic aspects of, 533 
 
 — articles of, for the feet, 526 
 
 — boots as articles of, 527 
 
 — coats and waistcoats as articles of, 523 
 
 — cotton as a maierial for, 513 
 
 — flannel as a material for, 522 
 
 — flax as a material for, 514 
 
 — for the head, kinds of, 520 
 
 — forms of, for exercise, 525 
 
 — fur as a material for, 511 
 
 — india-rubber as a material for, 515 
 
 — kind and colour of, for resisting heat, 
 519 
 
 — kinds of, for resisting wind and cold, 
 518 
 
 — leather as a material for, 513 
 
 — materials used for, 509 
 
 — methods of fire-proofing, 535 
 
 testing quality of, 516 
 
 water-proofing and cleansing, 534 
 
 — of hospital patients, care of, 786 
 
 — principles of, for women, 525 
 
 — shoes as articles of, 529 
 
 — silk as a material for, 510 
 
 — thermal conductivities of articles of, 
 518 
 
 — trousers and knee-breeches as articles 
 of, 524 
 
 — uses of, 509, 621 
 
 — weight of, 532 
 
 — wool as a material for, 509, 517 
 Cloud, amount and forms of, 177 
 Clouston, Dr., on dysentery caused by sew- 
 age, 368 
 
 Coal-gas, composition of, 946 
 
 — effects of escape and inhalation of, 948 
 
 — nuisances connected with manufacture 
 of, 946 
 
 Coats and waistcoats, points desirable in, 
 
 523 
 CoBBOLD, Dr., on effects of sewage irrigation 
 
 on health of cattle, 886 
 Coca, effects of, 399 
 Cocoa, composition and action of, 491 
 Ccenurus cerebralis in meat, 498 
 Coffee, composition of, 490 
 
 — physiological action of, 488 
 Cold, effects of exposure to, 188 
 
 local application of, 624 
 
 Colostrum, composition of, 428 
 Combustion, impurities in air, due to, 15 
 Comeliness, effect of exercise upon, 556 
 
 DEV 
 
 Comfort, bodily, as caused by exercise, 558 
 Comma bacillus and Asiatic cholera, 344 
 Concrete, sites of dwellings to be covered 
 
 with, 660 
 Condiments as food-accessories, 479 
 Conservancy, comparison of systems of, 
 
 826 
 
 — systems of, 812 
 Consumption hospitals, 744 
 Convalescent hospitals, 744 
 Cooling, artificial, 139 
 
 Copper, detection of, in water, 290 
 CoitFiELD, I'rof., siplion trap devised by, 769 
 Corrosive sublimate, spray containing, for 
 
 treatment of wounds, 789 
 Cotton, as a material for clothing, 513 
 CouLiEK and Hammonb on conducting powers 
 
 of different materials, 517 
 Cow, composition of milk of, 428 
 
 — disease of, as affecting milk, 431 
 
 — quantity of milk supplied by, 434 
 Cream, composition of, 43G 
 
 — estimation of, in milk, 435 
 Ceookshank, Dr., on cultivation of micro- 
 organisms in water, 297 
 
 Crops best suited for sewage farms, 878 
 Croydon sewage farm, system at, 876 
 Cubic space per head, amount of, required 
 
 in rooms, 20 
 
 measurement of, 21 
 
 CuLLiNGWORTH, Dr., on results of antisepti- 
 
 cism in lying-in hospital, 800 
 Cumberland asylum, epidemic of dysentery 
 
 in, 368 
 Cumulus and cumulo-stratus, 178 
 Cunningham's blowing machine, 81 
 CuRKiE, Dr., on effects of cold baths in 
 
 fevers, 618, 631 
 Cycles, forms of, 586 
 Cycling, as an exercise, 588 
 
 — for girls and ladies, drawbacks to, 593 
 
 — objections urged against, 589 
 
 — precautions regarding, 591 
 
 — troubles alleged to be caused by, 590 
 Cysticercus cellulosce in meat, 446 
 of beef, 447 
 
 Damp-pkoof courses in buildings, 661 
 Dabwin, H., instrument for measuring 
 
 differences of pressure, 107 
 Davaine on anthrax bacillus, 376 
 Davies, Dr. A. M., on naked-eye characters 
 
 of colonies of bacteria, 29 
 De Chaumont, Prof., on CO.^ in air as a 
 
 standard of impurity, 17 
 position of inlets for hospital 
 
 wards, 120 
 relation between ah required 
 
 and initial cubic space, 116 
 
 standard of purity of air, 23 
 
 suspended matters in au% 5 
 
 wells affected by nearness to 
 
 sea, 238 
 De Laune, on plague in London (1665), 651 
 Dengue, in warm climates, 207 
 Deserts, climates of, 210 
 Dessau, lead-poisoning from water at, 257 
 Development, bodily, effects of exercise 
 
 upon, 542 
 
998 
 
 HYGIENE 
 
 DIA 
 
 Diaphoresis, means of producing, 639 
 Diarrhoea, as related to soil, 362 
 ^ attacks of, due to effluvia, 12 
 
 — conclusions as to causes of, 366 
 
 — due to drinking water, 271 
 
 — mortality from, in Buffalo, U.S., 364 
 London (table), 365 
 
 — prevalence of, as affected by density of 
 population, 657 
 
 DiBDiN, Mr., on composition of sewage 
 
 sludge, 862 
 Diet and dietaries, 404 
 
 — conditions affecting, 404 
 
 — effects of, on character of fteces, 412 
 
 — influence of age and climate on, 407 
 constitution and work on, 407 
 
 — nitrogenous and non-nitrogenous food- 
 stuffs in, 408 
 
 — proportion of fat to carbo-hydrates in, 
 409 
 
 foodstuff's in articles of, 411 
 
 Diets, adapted for rest, 404 
 for work, 405 
 
 — amount of carbon and hydrogen in, 405 
 foodstuff's in 417 
 
 — construction of, 410 
 
 — for soldiers and sailors, 414 
 
 — in prisons and workhouses, 416 
 ■ — of the working classes, 415 
 
 — salts and water of, 406 
 
 — special, 413 
 
 — standard, estimation of, 404 
 Digestion, as aft'ected by alcoholic stimu- 
 lants, 477 
 
 Dines' hygrometer, 166 
 
 Dip-candle making, nuisance due to, 910 
 
 Diphtheria, bacillus of, 339 
 
 — from air vitiated by sewage emanations, 
 12 
 
 contamination of soil, 337 
 
 — increasing prevalence of, in England, 
 895 
 
 Diseases attributed to conditions of soil, 
 331 
 
 — caused by food, 424 
 meat, 444 
 
 Disinfection, aerial, in isolation wards, 795 
 Distoma heimticwn in meat, 498 
 Divers, eft'ects of occupation upon, 195 
 Dormitories in schools, arrangements of, 
 709 
 
 cubicle system in, 710 
 
 Drains, best forms of, 765 
 ■ — defects of, 764 
 
 — examination and testing of, 776 
 
 — fall or inclination of, 766 
 
 — flushing of, 772 
 
 — foundation of, 765 
 
 — functions of, 764 
 
 — gulley-traps for, 770 
 
 — man-hole for, 768 
 
 — methods of connecting pipes of, 765 
 
 — plans of laying, 767 
 
 — size of pipes in, 766 
 
 — tests for, 768 
 
 — traps for, 769 
 
 — waste-pipes cut off from, 771 
 Dress, ffisthetic aspects of, 533 
 Dressings, boxes and tables for, in hospitals, 
 
 788 
 
 DWE 
 
 Drilling as a part of gymnastics, 596 
 Drinking-water, good, characters of, 298 
 Drugs, dissolved, question as to cutaneous 
 
 absorption of, 628 
 Dujabdin-Beadmetz on impurities in alco- 
 holic drinks, 486 
 Dukes, Dr. C, on school dormitories, 709 
 Dumb-bells, use of, in gymnastics, 601 
 Dung-heaps, nuisances arising from, 923 
 DuPRK, Dr., on action of water on lead, 257 
 
 — and Haice, detection of organic matter 
 in water, 284 
 
 modification of Frankland's me- 
 thod of estimating organic matter in 
 water, 283 
 
 Dust and smoke in air, 48 
 
 — conditions checking or favouring accu- 
 mulation of, 50 
 
 — estimation of number of particles of, in 
 air, 49 
 
 — in mines and factories as a cause of 
 lung-disease, 7 
 
 Dwellings, back-to-back, faults of, 682 
 tubercular disease in, 684 
 
 — blocks of, defects in, 679 
 
 — cellar, rules for, 688 
 
 — cisterns, use of, in, 666 
 
 — classification of, in United Kingdom, 
 657 
 
 — combined with shops, &c., 671 
 
 — common lodging-houses as, 685 
 
 — concrete for covering sites of, 660 
 
 — conditions necessary for healthfulness 
 of, 651 
 
 — construction of roofs of, 662 
 
 • — cottage, defective closet-accommodation 
 
 in, 681 
 faulty sites for, 682 
 
 — dampness of, as related to diphtheria, 
 338 
 
 — damp-proof courses in, 661 
 
 — defective drainage in large, 668 
 
 — defects in ordinary, 670 
 
 — designed for wage-earning classes, 673 
 
 — drainage of, 764 
 plans for, 767 
 
 — drain-pipes for, position of, 767 
 
 — evils of crowding, on confined areas, 653 
 
 — external walls of, 661 
 
 — for agricultural labourers, 676 
 — • — artisans, 677 
 
 in metropolis, 656 
 
 working classes in France, 675 
 
 — height of, as influencing health, 657 
 
 — hygiene of, connected with density of 
 population, 656 
 
 — increase of, in recent years, 658 
 
 — light and ventilation of, 663 
 
 — model, death-rate in, 680 
 
 — necessary conditions in construction of, 
 659 
 
 — protection of, from ground-exhalations, 
 659 
 
 — removal of solid and liquid refuse from, 
 663 
 
 — rooms in, heating surface required for 
 warming, 138 
 
 — storage and distribution of water in, 
 666 
 
 — used as institutions, 689 
 
 V 
 
 I 
 
INDEX 
 
 999 
 
 DWE 
 
 Dwellings, water-closets suitable for, 664 
 Dysentery, diarrhoea, and tropical abscess 
 of liver, 208 
 
 — due to drinking-water, 272 
 
 — prevalence of, as affected by soil, 367 
 
 Ealing, refuse-destructor and fume-cre- 
 mator in use at, 810 
 
 Earth closets, 818 
 
 arrangements for, in schools, 713 
 
 soil from, as manure, 819 
 
 Easton, Mr., on utilisation of water passing 
 through chalk, 239 
 
 Education Department, rules of, for space, 
 &c., in schools, 707 
 
 Eggs as articles of diet, 440 
 
 — composition of, 441 
 
 — digestibility of, 441 
 
 — storage of, causing a nuisance, 924 
 Egypt, climate of, 210 
 
 Eheenbeeg on microscopical examination 
 of dust-showers, 5 
 
 EisELBEKG on relation of tetanus to soil, 
 375 
 
 Electricity as a method of depositing dust- 
 particles, 51 
 
 — atmospheric, as influencing climate, 199 
 Electrolysis, sewage precipitated by, 868 
 Emphysema, treatment of, by compressed 
 
 air, 644 
 Endurance, exercises involving, 610 
 Energy, expended by body, estimation of, 
 
 401 
 England, deaths from urinary calculus in, 
 
 379 
 Epidemics in towns, lessons to be gathered 
 
 from, 652 
 Ergot of rye, symptoms due to, 467 
 Ekichsen, Prof. J. E., on the ' big-house ' 
 
 plan of hospitals, 722 
 Erysipelas, effects of Listerism in diminish- 
 ing, 799 
 Examination of drains, methods of, 766 
 Excreta, human, quantity and composition 
 
 of, 810 
 
 — the pail system for removal of, 814 
 
 — water-carriage system for removal of, 
 827 
 
 Exercise, boating as a form of, 580 
 
 — boxing as a form of, 579 
 
 — cycling as a form of, 586 
 
 — effects of, on accumulation of fat, 554 
 
 — blood-current, 561 
 
 — development, 542 
 
 elimination of carbon, 555 
 
 kidneys, 556 
 
 muscular and nervous systems, 
 
 552 
 
 personal comeliness and com- 
 fort, 556 
 
 tissues and organs generally, 
 
 553 
 
 — excessive~or unsuitable, effects of, 567 
 
 — fencing as a form of, 578 
 
 — forms of, 610 
 
 for children, 611 
 
 girls and women, 612 
 
 males at various ages, 613 
 
 FLO 
 
 Exercise, gymnastics and calisthenics as 
 forms of, 59.3 
 
 — jumping as a form of, 595 
 
 — mental and moral effects of, 558 
 
 — outdoor games as forms of, 605 
 
 — riding as a form of, 577 
 
 — rules for conducting forms of, 600 
 
 — running as a form of, 574 
 
 — skating as a form of, 576 
 
 — specific forms of, .^72 
 
 — systematised, effects of, on circumfer- 
 ence of chest, 548 
 
 development and growth, 
 
 547 
 
 — walking as a form of, 573 
 
 Exertion, physical, natural craving for, 541 
 Exhalations from the sick, effects of, 11 
 
 Fabbics for clothing, modes of testing, 516 
 Fffices, character of, as influenced by diet, 
 
 412 
 Fans, for the production of ventilation, 77 
 Fat, removal of, by exercise, 554 
 Fat-melting, nuisance due to, 910 
 
 — bye-laws regulating, 911 
 
 Fatigue, breathlessness as a sign of, 500 
 
 — general, 566 
 
 — muscular, explanation of, 564 
 
 — phenomena of, 560 
 
 Fats, amount of, in meat, 443 
 
 — as food, 395, 399 
 
 Faybee, Sir J., on cause of monsoons, 197 
 
 malaria, 209 
 
 subsoil water as a condition of 
 
 malaria, 209 
 
 • sunstroke, 205 
 
 Feet, articles of clothing for, 525 
 Fellmongering, nuisance caused by, 915 
 Fencing, as an exercise, 578 
 Fever, as a symptom of over-exertion, 566 
 
 — effects of cold baths upon, 620, 631 
 Field, Mr. Eogers, flushing siphon devised 
 
 by, 772 
 
 siphon trap devised by, 769 
 
 File-cutters, danger of lead-poisoning 
 
 among, 962 
 Filter-beds, construction of, 252 
 Filters, materials used for, 251 
 
 — household, materials suitable for, 254 
 Filtration, on large scale, 251 
 Fire-grates, for increasing radiation, 124 
 Fire-proofing, recipes for, 535 
 
 Fish, as an article of food, 444 
 
 — frying, nuisance due to, 907 
 
 — injury to, by effluent sewage, 865 
 
 • — part played by, in purifying water, 851 
 
 — storage of, causing nuisance, 923 
 Flannel, as a material for clothing, 522 
 Flats, residential, sanitary condition of, 670 
 Flax, as material for clothing, 514 
 Flesh, as an article of food, 441 
 
 — boiling, nuisance caused by, 902 
 Floating hospitals, for infectious diseases, 
 
 752 
 
 small-pox cases, 753 
 
 Floors of hospitals, materials for, and 
 
 cleaning, 779 
 Flour, wheaten, 456 
 adulterations of, 462 
 
1000 
 
 HYGIENE 
 
 Flour, wheaten, amount of gluten in, 461 
 
 examination of, 461 
 
 parasites in, 462 
 
 preparations of, 458 
 
 Flues, position of, for ventilation, 118 
 Flugge on micro-organisms in soil, 314 
 Flukes, in sheep's liver, 447 
 Fodder, peculiarities of, as affecting meat, 
 
 445 
 
 milk, 444 
 
 FoDOR, on action of micro-organisms in soil, 
 
 315 
 
 amount of moisture in soil, 325 
 
 moisture in soil and diffusion of 
 
 cholera, 343 
 
 nitrification of soil, 313 
 
 temperature of soil, 327 
 
 typhoid at Buda-Pesth, 335 
 
 Fogs, method of recording density of, 179 
 Food-accessories, 474 
 
 aromatic principles as, 475 
 
 as stimulating digestion, 476 
 
 secretions, 476 
 
 classes of, 475 
 
 nervine stimulants and sedatives as, 
 
 475 
 
 retarding effect of, on digestion, 479 
 
 taken as liquids, 480 
 
 variations in action of, 477 
 
 Food, animal, 427 
 
 effects of cooking upon, 422 
 
 large quantities of, 399, 424 
 
 — articles of, 426 
 
 — bulk, and reaction of, as affecting diges- 
 tion, 420 
 
 — daily arrangement of, in meals, 417 
 
 — definition and uses of, 393 
 
 — digestibility of, 418 
 
 — diseases caused by, 424 
 
 — eft'ects of diminution of, 425 
 excess of, 424 
 
 — inorganic constituents of, 400 
 
 — perfect, milk as a type of, 410 
 
 — preparation of, 421 
 
 — proximate principles of, 393 
 
 — variety of, desirable, 479 
 
 — vegetable, 449 
 
 classification of, 455 
 
 composition of, 450 
 
 — ■ — effects of cooking upon, 422 
 
 — • — preparation of, 450 
 
 proteids in, 450 
 
 uses of, 449 
 
 Foodstuffs, carbo-hydrates as, 395 
 
 — change of, in the body, 396 
 
 — classification of, 393 
 
 — construction of diets with, 410 
 
 — differences in nutritive value of, 403 
 
 — fats as, 396 
 
 — inorganic, 396 
 
 — isodynamic, 402 
 
 — nitrogenous, 393 
 
 and non-nitrogenous in diet, 408 
 
 composition of, 394 
 
 — non-nitrogenous, organic, 395 
 
 — nutritive value of, 401 
 
 — potential energy of, 402 
 
 — proportions of, in articles of diet, 411 
 
 — proteid-sparing, 398 
 
 — vegetable acids as, 396 
 
 GOL, 
 
 Foot-and-mouth disease affecting meat, 501 
 
 milk, 432 
 
 Football, value of game of, 606 
 Form, female, proportions of, 550 
 FoEsTER on proportion of fat to carbo- 
 hydrates in diet, 409 
 water in food before and after cook- 
 ing, 423 
 Fox. Dr., on ozone, 179 
 Fi;axkl.^d, Dr., on classification of waters 
 according to organic purity, 300, 302 
 
 estimation of nitrates in water, 282 
 
 organic matter in water, 283 
 
 spontaneous purification of rivers, 
 
 242, 264 
 
 — Dr. P., on examination of micro-organisms 
 in air, 28 
 
 water, 296 
 
 Fr.tDraicQ and Quinquand on effects of 
 
 application of cold, 620 
 French schools, rules for dormitories in, 
 
 709 
 Frey and Heiligenthal on effects of 
 
 Piussian baths, 640 
 
 Turkish baths, 638 
 
 Friction of air in tubes, losses by, 64, 66 
 Friends, visits of, to patients in hospitals, 
 
 785 
 Fruit and vegetables, nuisances arising 
 
 from, 924 
 Fruits, composition of, 472 
 Fuel, heat developed by various kinds of, 122 
 
 — waste of, in open fireplaces, 123 
 Fur, as a material for clothing, 511 
 
 Games, outdoor, value of, 605 
 
 Gas fires and stoves for warming, 128 
 
 Gases, diffusion of, in air, 45 
 
 — in water, question as to cutaneous ab- 
 sorption of, 618 
 
 — irrespirable, morbid effects from, 937 
 Gateshead Union, plan of workhouse of, 
 
 718 
 Gelatine as an article of food, 398 
 Girls and women, selection of exercises for, 
 
 612 
 
 — rate of growth and development of, 545 
 Gladstone and Tribe on detection of 
 
 nitrates in water, 281 
 Gl-usher and Coswell, experiences of 
 
 balloon ascent, 193 
 Glaisher's thermometer stand, 169 
 Glasgow University, heating and ventilation 
 
 of, 146 
 
 — water supply of, 232 
 
 Glass-cutters, danger of lead-poisoning 
 
 among, 962 
 Globulins as articles of food, 394 
 Glossop, fatal cases at, due to inhalation of 
 
 coal gas, 949 
 Glue, nuisance arising from manufacture 
 
 of, 908 
 Gluten, amount of, in flour, 461 
 Goitre and cretinism, as related to nature 
 
 of soil, 381 
 associated with use of hard water, 
 
 259, 273, 383 
 Golf as an exercise, advantages of, 574 
 GoLGi on micro-organisms of malaria, 353 
 
INDEX 
 
 1001 
 
 GOU 
 
 Goux system for removal of excreta, 815 
 Graham, Dr. C, on chemistry of bread- 
 making, 458 
 
 — Prof., on effects of hardness of water, 
 258 
 
 Gbange on magnesian limestone soil and 
 
 goitre, 384 
 Granite as an element of soils, 310 
 Geantham, Mr. R. F., on separate system of 
 
 sewage, 836 
 Grates, ventilating, dimensions for, 126 
 Graveyards, air of, effects from, 12 
 Grease from sinks, methods of dealing 
 
 with, 775 
 
 — nuisance due to recovery of, from soap- 
 suds, 909 
 
 Great Northern Central Hospital, plan of, 
 
 726 
 Gbeenhow, Dr., on causes of epidemic 
 
 diarrhoea, 362 
 diphtheria associated with nasal 
 
 diseases of cattle, 337 
 prevention of pulmonary phthisis, 
 
 355 
 Ground air, carbon-dioxide in, 318 
 
 carburetted hydrogen in, 320 
 
 composition of, 318 
 
 currents of, 322 
 
 — estimation of carbon dioxide in, 323 
 
 nitrogen in, 319 
 
 variations of carbon dioxide in, 321 
 
 — exhalations, protection of interior of 
 dwellings from, 659 
 
 — or subsoil water, 325 
 
 — cholera connected with move- 
 ments of, 341 
 
 — malarious fevers connected 
 
 with movements of, 348 
 
 movements of, 326 
 
 typhoid connected with move- 
 ments of, 336 
 Gulf Stream, influence of, 201 
 GuUey traps, for surface water, 770 
 Gums, blue line on, in lead-poisoning, 960 
 Gut-cleaning, nuisances due to, 903 
 Gutta-percha, as material for clothing, 516 
 Gymnasia and gymnastic apparatus, 599 
 
 — home, 605 
 
 — rules for management of, 600 
 Gymnastics and calisthenics, 593 
 
 — cautions with regard to, 600 
 
 — English system of, 594 
 
 — German system of, 595 
 
 — Swedish or Ling's system of, 597 
 
 Haglee, Dr., on outbreak of typhoid at 
 
 Lausen, 270 
 Hail, varieties of forms of, 178 
 Hair- and flock-picking, nuisance caused 
 
 by, 925 
 Halifax, back-to-back houses in, 683 
 Halle, University Hospital, plan of, 735 
 Hand-rings, use of, in gymnastics, 602 
 Hardness of water, 258 
 
 alleged effects of, 259 
 
 — as a cause of calculus, 380 
 
 estimation of, 290 
 
 Hats, forms of, 520 
 
 HOS 
 
 Havilanb on cancer as related to condi- 
 tions of soil, 378 
 
 Hawksley, Mr. T., on effects of hardness of 
 water, 259 
 
 on rainfall available for water- 
 supply, 232 
 
 Head, clothing suitable for, 520 
 
 ' Head ' in ventilation, meaning of term, 56 
 
 Head, proportions of, during growth, 550 
 
 Health, influence of soil upon, 309 
 
 — physical, importance of, 540 
 
 Heart and blood-vessels, lesions of, from 
 
 excessive exertion, 569 
 Heat, application of, for cleansing surgical 
 
 instruments, 791 
 
 — as a form of energy, 34 
 
 — clothing suitable for resisting, 519 
 
 — conduction of, 36 
 
 — convection of, 39 
 
 — distribution of, 36, 131 
 
 - — effects of exposure to, ISO 
 
 — formed in body, estimation of, 401 
 
 — gain and loss of, by soils, 329 
 
 — latent, 35 
 
 — loss of, conditions checking or favour- 
 ing, 40 
 
 — predisposing to tetanus, 374 
 
 — production and measurement of, 33 
 of, by friction, 34 
 
 — quantities of, produced by combustion 
 of various fuels, 35 
 
 — radiation of, 37 
 
 — relation of, to bodily work, 553 
 
 — specific, 36 
 
 Hehnek on determination of fatty acids in 
 
 butter, 438 
 Height, relative, of adults and boys under 
 
 varying conditions, 546 
 Heights, measurements of, by barometer, 
 
 156 
 Hernia, production of, by violent exercise, 
 
 571 
 Hesse on micro-organisms in air, 28 
 Hetmann and Keebs, on electrical oi^erations 
 
 of baths, 629 
 Hides as a source of anthrax, 930 
 
 — nuisances caused by preparation of, 916 
 HiLGEB, on melting points of various fats, 
 
 438 
 
 HiRscH on geographical distribution of 
 calculus, 380 
 
 HiET on health of workers in chlorine, 
 939 
 
 Honey, composition of, 454 
 
 Horse-slaughtering, nuisance due to, 900 
 
 Horsehair, nuisance connected with pre- 
 paration of, 935 
 
 Hospital at Antwerp, plan of, 737 
 
 — - — Halle, plan of, 735 
 
 — — Lincoln, plan of, 740 
 
 — for infectious diseases at Leamington, 
 760 
 
 — ■ Newcastle, 750 
 
 — Great Northern, plan of, 726 
 
 — Guy's, results of Listerism on erysipelas 
 in, 799 
 
 — Moabit, Berhn, plan of, 739 
 
 — St. Denis, Paris, plan of, 740 
 
 — St. George's, statistics of amputations 
 in, 798 
 
1002 
 
 HYGIENE 
 
 HOS 
 
 Hospital, workhouse, plans of, 742 
 Hospitals, amount of water necessary for, 
 245 
 
 — at York and Manchester, defects in, 721 
 
 — classification of, 722 
 
 — cleaning of floors of, 779 
 
 — contamination of air of, 719 
 
 — cottage, 743 
 
 — cubic space per head required in, 20 
 
 — dangers to patients in, 719 
 
 — defects in construction of, 719 
 
 — fissures in floors of, 780 
 
 — hygiene of, 779 
 
 — improper arrangements of buildings of, 
 722 
 
 — materials for floors of, 779 
 
 — necessity for speedy removal of excreta, 
 &c., from, 721 
 
 — position of inlets for wards in, 120 
 
 — purity of air, a necessity in, 720 
 
 — purposes for which constructed, 718 
 results of improved hygiene in, 796 
 
 — ventilation and warming of, 761 
 artificial in, 762 
 
 of small-pox, 763 
 
 various systems of, 762 
 
 — general, administration oflices of, 725 
 
 — — arrangements of essential parts of, 
 724 
 
 balconies in, 732 
 
 bath-rooms in, 732 
 
 care and cleansing of instruments in, 
 
 790 
 
 care of patients' clothing in, 786 
 
 circular wards in, 728 
 
 cleaning of bedding in, 782 
 
 cooking arrangements in, 794 
 
 dresses of attendants in, 783 
 
 dresses of surgeons performing opera- 
 tions in, 784 
 
 examples of plans of, 735 
 
 floor and cubic space in, 727 
 
 form of wards in, 728 
 
 isolation wards in, 794 
 
 lockers for patients' necessaries in, 
 
 786 
 
 materials for floors of, 731, 779 
 
 walls of, 730 
 
 raovtnarj a.n6. post-mortem rooms in, 
 
 738 
 
 nurses' rooms in, 731 
 
 open space around, 723 
 
 operation rooms in, 732 
 
 ornaments for walls of, 781 
 
 out-patient department of, 733 
 
 rectangular pavilion wards in, 729 
 
 site area of, per bed, 723 
 
 sites for, 723 
 
 size of wards of, 727 
 
 statistics of amputations in, before 
 
 and after Listerism, 798 
 
 tables and boxes for dressings in, 788 
 
 ventilation of, 727, 761 
 
 — -— visits of friends to patients in, 785 
 walls of, 781 
 
 ward offices in, 731 
 
 water-closets for patients in, 731 
 
 windows in wards of, 730 
 
 — special, 744 
 children's, 744 
 
 JOH 
 
 Hospitals, special, consumption, 744 
 
 convalescent, 744 
 
 floating, for infectious diseases, 752 
 
 for infectious diseases, 745 
 
 isolation blocks in, 747 
 
 open space around, 749 
 
 ■ plans and types of, 746 
 
 small-pox, dangers of, 753 
 
 i-ecommendations for, 753 
 
 the insane, 754 
 
 lying-in, 745 
 
 details of management of, 801 
 
 results of antisepticism in, 800 
 
 ophthalmic, 744 
 
 Hotel-Dieu, Paris, condition of, in last 
 
 century, 719 
 Hotels, inns, etc., sanitary conditions and 
 
 defects in, 673 
 House drains, pipes for, 834 
 Houses, back-to-back, defects of, 683 
 
 — of ParUament, ventilation of, 145 
 
 — overcrowding of, as a cause of disease, 
 652 
 
 Housing of working classes, Acts relating to, 
 
 674 
 Howard, John, on condition of prisons in 
 
 last century, 690 
 Humidity as influencing climate, 189 
 Hydatid disease, production of, 447 
 Hydrochloric acid vapours, efl'ects of, in 
 
 air, 10 
 Hydrogen-sulphide, effects of, in air, 10 
 Hygrometer, Dines', 166 
 
 — Saussuee's, 166 
 Hygrometi'y, 164 
 
 Ice, machines for artificial production of, 
 
 139 
 Immisch's thermometers, 163 
 India, effects of climate of, on Europeans, 
 
 187 
 India-rubber as a material for clothing, 
 
 515 
 
 — nuisance connected with manufacture of, 
 930 
 
 Indian clubs, use of, in gj'mnastics, 601 
 
 Infectious diseases, hospitals for, 746 
 
 Infirmaries for schools, 755 
 
 Inlets and outlets, position of, for ventila- 
 tion, 118 
 
 Insane, asylums for, 754 
 
 Instruments, care and cleansing of, in hos- 
 pitals, 790 
 
 Iodine, nuisances connected with manufac- 
 ture of, 950 
 
 Ireland, immunity of, from calculus, 379 
 
 Iron, estimation of, in water, 293 
 
 — sulphate, use of, to precipitate sewage, 
 859 
 
 — uses of, in food, 401 
 Irrigation of sewage, 873 
 into subsoil, 886 
 
 — practice of, in surgical operations, 789 
 
 Jaws, necrosis of, caused by phosphorus, 
 
 969 
 Johnson's filter press for dealing with 
 
 sewage, 861 
 
INDEX 
 
 1003 
 
 JON 
 
 Jones, Mr., Destructor and fume cremator 
 
 furnace for refuse, etc., 810 
 Joule, J. P., on dynamical cooling of air, 
 
 43 
 Jumping and skipping as forms of exercise, 
 
 575 
 
 Kelly, Dr., on connection between drainage 
 
 and phthisis, 359 
 Khamseen, the, a kind of wind in Egypt, 
 
 211 
 KiTiSATO on the bacillus of tetanus, 372 
 Kjbldahl on estimation of organic matters 
 
 in water, 285 
 Klebs and Tommasi-Crudeli on bacillus 
 
 malarise, 209, 351 
 
 of diphtheria, 339 
 
 Klein, Dr., on comma bacillus, 345 
 
 — detection of micro-organisms in 
 
 water, 297 
 Knackeries, nuisances due to, 900 
 Knapsacks, forms of, 533 
 Knotx on fever of over-exertion, 566 
 Koch on bacillus tuberculosis, 36C 
 examination of micro-organisms in 
 
 air, 28 
 
 significance of comma bacillus, 344 
 
 spores of anthrax, 931 
 
 Kohl on Eussian baths, 640 
 
 Kola, effects of, 399 
 
 KoNiG on composition of various kinds of 
 
 meat, 442 
 
 daily diet for children, 408 
 
 proportion of foodstuffs in articles of 
 
 diet, 411 
 Koumiss and Kiphir, 433 
 Keause on cutaneous absorption of water, 
 
 627 
 
 Ladders, various forms of, used in gym- 
 nastics, 603 
 
 Lads, selection of exercises for, 613 
 
 Lagrange, Dr., on effect of exercise on 
 tissues, 553 
 
 exercises which develop the chest, 
 
 611 
 
 — • — phenomena of fatigue, 560 
 
 Lakes, characteristics of water stored in, 
 234 
 
 Landois, Prof., on cause of local muscular 
 fatigue, 565 
 
 Lariboisi^re Hospital. Paris, ventilation of, 
 762 
 
 Latham, Mr. B., on construction of sewers, 
 831 
 
 effect of pumping out ground- 
 water, 288 
 
 Laundries for residential schools, 714 
 
 Lausen, Switzerland, outbreak of typhoid 
 at, 270 
 
 Lavatories in schools, 710 
 
 Lawes and Gilbert, on percentage compo- 
 sition of wheat-grain ash, 457 
 
 Lead, action of water on, 256, 668 
 
 on, by various matters in water, 256 
 
 — dangers to workers in, 958 
 
 — detection of, in water, 290 
 
 — determination of action of water upon, 
 295 
 
 LUN 
 
 Lead in water, 256 
 
 — prevention of water from dissolving, 248, 
 258 
 
 — symptoms of poisoning by, 959 
 
 — trades in which danger of poisoning by, 
 962 
 
 — poisoning, prevention of, as related to 
 condition of soil, 369 
 
 sanitary precautions against, 965 
 
 Leamington, hospital for infectious diseases 
 
 at, 750 
 Leather-making, nuisance caused by, 915 
 Leeds, back-to-back bouses in, 683 
 Leek Workhouse, diarrhoea at, due to water, 
 
 271 
 Leguminosse, seeds of, as articles of food, 
 
 469 
 
 digestibility of, 469 
 
 Leichtenstein, on effects of salts and gases 
 
 in water, 629 
 
 — warm baths-, 635 
 
 loss of heat caused by cold baths, 
 
 621 
 Lemon and lime-juice, composition of, 
 
 473 
 
 value of, 472 
 
 Lewis and Cunningham on carbon-dioxide 
 
 in ground air, 318, 323 
 — ground-water and spread of 
 
 cholera, 341 
 
 — temperature of soil, 328, 330 
 
 Liebenbeeg on gain and loss of heat by 
 
 soils, 329 
 Liebeemeister on effects of cold baths, 621 
 Lieenur's system of sewage, 849 
 Lighting and ventilation of dwellings, 663 
 Lightning, effects of, 200 
 Limbs, proportions of, during growth, 550 
 Lime, use of, to precipitate sewage, 858 
 Lime-burning, nuisances arising from, 942 
 Lincoln County Hospital, plan of, 740 
 Ling, system of gymnastics founded by, 
 
 598 
 Linoleum, nuisance and dangers connected 
 
 with manufacture of, 926 
 Lister, Sir J., improvements in hospital 
 
 hygiene due to, 797, 800 
 Liverpool, arrangements for abattoirs at, 
 
 988 
 
 — licences for private slaughter-houses in, 
 985 
 
 Lockers for hospital use, 786 
 
 LocKWOOD, Mr., on tetanus produced by in 
 
 oculation, 373 
 Lodge, Dr. 0. J., on dust-particles in aii', 
 
 48 
 Lodging-houses, common, provisions for 
 
 control of, 685 
 
 definition of, by law, 686 
 
 Local Government Board rules 
 
 for, 686 
 Lodgings, houses let in, rules for, 688 
 Lolium tevudentum (darnel), effects of, in 
 
 bread, 463 
 London, amount of water supplied to, 244 
 
 — mortality in 1600-1800, 890 
 
 — regulations for private slaughter-houses 
 in, 986 
 
 Lungs, affections of, caused by violent 
 exercise, 570 
 
1004 
 
 HYGIENE 
 
 LUN 
 
 Lungs, deaths from diseases of, among 
 
 miners, 6 
 Lying-in hospitals, 745 
 
 Macalistek, Dr., on effect of cold on 
 
 muscles, 620 
 Macaroni, composition of, 460 
 Macdoxald, Dr. J. D., on microscopical 
 
 examination of drinking-water, 276 
 Machines for production of cooling, 139 
 M.\CL.\KEN on growth of hoys, 545 
 increased development as result of 
 
 exercise, 548 
 
 system of measurements, 551 
 
 Maclean, Dr., on development of malaria 
 
 at Hong Kong, 350 
 MACLEOD and Miller on the cholera 
 
 bacillus, 344 
 MacLintock, Dr., on treatment of sewage 
 
 by electrolysis at Bradford, 868 
 Macnamaba, Dr., on connection between rain 
 
 and diffusion of cholera, 343 
 Magnesian limestone in soil as causing 
 
 goitre, 384 
 Maize as a food, 467 
 
 — diseased, effects of, 468 
 
 — starch-grains of, 454 
 Malaria as related to soil, 347 
 
 — bacillus of, 209, 351 
 
 — conditions of soil favourable to, 209, 348 
 
 — connected with rickets, 382 
 
 — effects of, 210 
 
 — from drinking-water, 272 
 
 — influence of temperature upon, 348 
 
 — organisms associated with, 351 
 
 — preventive measures for, 353 
 
 — question as to causation of, by diinking- 
 water, 354 
 
 Malarious soils, characteristics of, 349 
 Manchester, cremation of refuse in, 821 
 
 — Infirmary, condition of, due to bad 
 drainage, 721 
 
 — water-supi)ly of, 232 
 Manganese, estimation of, in water, 293 
 Mansions, chief sanitary defects in, 669 
 
 — points connected with construction of, 
 668 
 
 Manures, artificial, nuisance due to, 919 
 
 — manufacture of, from excreta, 820 
 
 — storage of, causing nuisance, 922 
 Margarine, 439 
 
 Marlborough House, former defective 
 drainage of, 669 
 
 Maeshall, Mr. J., on circular hospital 
 wards, 728 
 
 Marshes, effects of air from, 13 
 
 Matches, dangers connected with manufac- 
 ture of, 967, 972 
 
 McClelland, Dr., on causation of goitre in 
 Himalayas, 383 
 
 Meals, arrangement of daily food in, 417 
 
 Measurements, bodily, methods of taking, 
 551 
 
 Meat, Acts referring to, 495 
 
 — affected by disease of animal, 445 
 
 — ■ peculiarities of fodder, 445 
 
 — amount of fat in, 443 
 
 — composition of, 441 
 
 — cysticercus cellulosse in, 446 
 
 MIL 
 
 Meat, decomposed, symptoms caused by, 445 
 
 — diseased, appearances of, 497 
 
 — diseases caused by, 444 
 
 — extract of, 449 
 
 — hydatid disease due to, 447 
 
 — inspection of, 495 
 
 in slaughter-houses, 991 
 
 — modes of dressing, 497 
 
 — of animals dead by accident, 504 
 
 suffering from anthrax, 502 
 
 ' braxy,' 502 
 
 foot-and-mouth disease, 501 
 
 pleuro-pneumonia, 501 
 
 swine fever, 503 
 
 diseased animals, 447 
 
 parturient animals, 504 
 
 — parasites in, 446 
 
 — parasitic diseases of, 498 
 
 — percentage composition of kinds of, 442 
 of bone with, 443 
 
 — preparations of, 448 
 
 — preservation of, 448 
 
 — putrefactive changes in, 444 
 
 — refrigerated, 497 
 
 — saline constituents of, 442 
 
 — sound, characteristics of, 496 
 
 — training for inspection of, 505 
 
 — trichiniasis due to, 446 
 
 — tubercles in, 499 
 
 — unsound, consequences of eating, 504 
 
 — variations in composition of, 443 
 Meinert on best food for working men, 
 
 416 
 Memphis, system of sewers at, 838 
 Mercury, dangers to workers in, 954 
 — - sanitary precautions for workers in, 957 
 
 — symptoms of poisoning by, 956 
 Metals, fumes of, as a cause of disease, 8 
 Meteorology, books and periodicals referring 
 
 to, 181 
 
 — instruments and methods employed in, 
 151 
 
 — observation hours for, 180 
 
 — relation of, to public health, 151 
 Metropolis, back-to-back houses in, 683 
 Mews, nuisance arising from, 923 
 Microbes in air, and contents of sewers, 
 
 840 
 Micro-organisms in air, examination of, 28 
 
 water, examination of, 296 
 
 Middens as receptacles of excreta, 812 
 
 — rules for construction of, 813 
 Middle-aged and elderly persons, exercises 
 
 for, 613 
 Milk, acidity of, 430 
 
 — adulterations, 435 
 
 — affected by disease in cow, 432 
 
 — and milk products, 427 
 
 — as a type of perfect food, 410 
 
 — as an article of diet, 428 
 
 — bacilli causing changes in, 431 
 
 — blue colour of, 430 
 
 — condensed, 433 
 
 — contamination of, as a cause of diph- 
 theria, 338 
 
 of typhoid, 334 
 
 — cow's, treatment of, for infants, 429 
 variations in composition of, 428 
 
 — diseased, abnormal constituents of, 434 
 bacteria in, 434 
 
INDEX 
 
 1005 
 
 MID 
 
 Milk, diseases caused by, 430 
 
 — estimation of cream in, 435 
 
 — examination of, 434 
 
 — fodder as affecting character of, 434 
 
 — infection of, by disease-poisons, 433 
 
 — preservation of, 433 
 
 — quantity of, supplied by one cow, 434 
 
 — reaction of, 435 
 
 — skimmed, 436 
 
 — specific gravity of, 435 
 
 — substances affecting, 431 
 
 — tuberculosis transmitted by, 432 
 Milks, composition of different, 410, 427 
 Millbank prison, outbreak of dysentery at, 
 
 368 
 
 of typhoid at, 269 
 
 Millet, as a food, 468 
 Miners, liability of, to lung diseases, 6 
 MiQUEL, on microbes in air, 6 
 MoLESCHOTT, on diet for men during work, 
 
 405 
 
 — on foodstuffs in quantities of food, 412 
 Monsoons, influence of, upon climate, 197 
 Montsouris, thermometer-stand, 170 
 MoBGAN, Dr. J. E., on effects of violent 
 
 exercise, 568 
 MoBiN, Gen., on dimensions of chimney 
 
 flues, 126 
 on heat, produced by combustion of 
 
 fuel, 122 
 
 — — on position of inlets for hospital 
 wards, 120 
 
 on proper temperature of buildings, 
 
 117 
 
 on velocity of draught in chimneys, 
 
 97 
 
 on vitiation of air by heated iron, 
 
 118 
 
 Mortality, as affected by density of popula- 
 tion, 656 
 
 Mortuaries, hospital, 733 
 
 MouAT, Dr., on sites for hospitals, 723 
 
 MotJLE, Eev. H., on dry-earth system for 
 closets, 818 
 
 Mountains, climate of, 220 
 
 Movement, necessity of, for health of body, 
 541 
 
 Munich, results of improved sewerage in, 
 894 
 
 MuECHisoN, Dr., on origin of typhoid, 333 
 
 McEGUE, M., on centrifugal ventilating 
 machines, 55, 60, 78 
 
 Muscles, effects of exercise upon, 541, 543, 
 552 
 
 Mustard, as a condiment, 480 
 
 MuYBEiDGE, Mr. E., on mechanics of walk- 
 ing, 574 
 
 Nantebee, plan of prison at, 694 
 Necrosis, acute, from mud and dirt getting 
 
 into wounds, 796 
 Negbetti and Zambba's maximum thermo- 
 meter, 163 
 Negroes, predisposition of, to tetanus, 374 
 Nervous system, effects of exercise upon, 
 
 552 
 Nesslee's re-agent, preparation of, 286 
 Nkttleship, Mr., on ophthalmia in poor 
 law schools, 704 
 
 PAI 
 
 Neva river, clarification of water of, 251 
 New River water, filtration of, 252 
 Newcastle-on-Tyne, hospital for infectioua 
 
 diseases at, 750 
 NicoLAiEK on micro-parasites as a cause of 
 
 tetanus, 371 
 Nimbus, 178 
 
 Nitrates in water, estimation of, 279 
 Nitrification of soils by organisms, 314 
 Nitrites in water, estimation of, 282 
 Nitrogen, amount of, in diets, 405 
 
 — elimination of, increased by exercise, 
 556 
 
 Nitrogenous matters, changes in, in passage 
 through soil, 264 
 
 — tissues, nutrition of, )397 
 Norfolk, prevalence of calculus in, 379 
 NoBTH, on conveyance of malaria by water, 
 
 354 
 Nuisances due to trades and manufactures- 
 899 
 
 Oatmeal as a food, 465 
 
 Oats, starch grains of, 454 
 
 Oeetel, on means of producing diaphoresis, 
 
 639 
 Offal, nuisances due to disposal of, 899 
 Ogle, Dr., on mortality of miners from. 
 
 phthisis, 6 
 Oil-boiling, nuisances connected with, 928 
 Oilcloth, nuisance and dangers connected 
 
 with manufacture of, 927 
 Open Spaces Act (1887), provisions of, 655 
 Operations in hospitals, antiseptic methods- 
 in, 789 
 
 dresses of surgeons performing, 
 
 784 
 Ophthalmia, prevalence of, in poor-law 
 
 schools, 704, 760 
 Ophthalmic hospitals, 744 
 Oppenheim on connection between rickets- 
 
 and malaria, 382 
 Organic matter in water, estimation of, 283 
 Frankland's method of esti- 
 mating, 283 
 
 Kjeldahl's method, 285 
 
 Tidy's method, 288 
 
 Wanklyn's method, 285 
 
 Organic matters, pollution of water by, 262 
 Organisms, parasitic, found in drinking- 
 water, 274 
 Orifices, estimation of volume of air pass- 
 ing through, and work spent in passage, 
 56,58 
 Osier-beds, use of, in sewage farms, 876 
 OsLEB, Dr. W., on dilatation of heart from 
 
 excessive exercise, 569 
 Out-patient department in hospitals, 733 
 Oxygen, action of, in purifying streams, 264 
 — dissolved, estimation of, in water, 294 
 Ozone, method of registering, 179 
 
 Pack, cold, as an antipyretic, 632 
 
 Paget, Mr. C. E., on space per child in 
 
 schools, 708 
 — Sir J., effects of lightning on human. 
 
 body, 200 
 Pail system for removal of excreta, 814 
 
1006 
 
 HYGIENE 
 
 Pane and gutter system for sewage-farms, 
 
 876 
 Paper-making, nuisance connected with, 
 
 7-29 
 Paraguay tea, composition of, 491 
 Paralysis, caused by lead, 961 
 Paris, manufacture of manure from excreta 
 
 in, 825 
 
 — St. Denis Hospital, plan of, 740 
 Pakkes, Dr., on CO^j given off in respira- 
 tion, 14 
 
 composition of soldiers' rations, 414 
 
 conditions necessary for healthful 
 
 dwellings, 651 • 
 
 — on effects of time on organic refuse in 
 soil, 660 
 
 innocuous amounts of alcohol, 484 
 
 malaria, 209 
 
 from drinking-water, 272 
 
 quantity of water for domestic use, 
 
 244 
 results of exercise, 556 
 
 — — tests of quality of potatoes, 471 
 Pasteur, on bacillus anthracis, 376 
 Paton on silk fibres, 510 
 
 starch in cotton, 513 
 
 Peclet, M., on flow of air through ducts, 64 
 
 Pepper as a condiment. 480 
 
 Peppermint, oil of, for testing drains, 776 
 
 Permanganate method for determining 
 organic matter in water, 288 
 
 Persons, number of, per acre of open space 
 in towns, 655 
 erspiration, air vitiated by, 15 
 
 Petkie, Dr., on examination of micro- 
 organisms in air, 29 
 
 Pettekkofer, Dr., on aqueous vapour in 
 expired air, 15 
 
 CO2 excreted by lungs, 14 
 
 in ground air, 318 
 
 — — — determining height of ground- 
 water, 327 
 
 effect of subsoil drainage on fever 
 
 of horses, 349 
 
 — . estimation of air in soils, 323 
 
 CO, in air, 23 
 
 hourly excretion of CO,, 14 
 
 . increased elimination of carbon 
 
 during exercise, 555 
 soil-water and dift'usion of cholera, 
 
 341 
 Phillips' maximum thermometer, 162 
 Phipson, W. W., on heating and ventilating 
 
 apparatus of Glasgow University, 146 
 Phosphates, value of, in food, 400 
 Phosphorus, dangers to workers in, 967 
 
 — diseases produced by fumes of, 8 
 
 — matches, manufacture of, 967 
 
 — necrosis of jaws caused by, 969, 972 
 
 — nuisance connected with manufacture of, 
 966 
 
 — sanitary precautions to prevent poison- 
 ing by, 971 
 
 — storage of, 970 
 
 — symptoms of poisoning by, 972 
 Phthisis, as related to dampness of soil, 
 
 355, 660 
 
 — from vitiated air, 11 
 
 — mortality from, reduced by construction 
 of sewers, 829 
 
 FBI 
 
 Phthisis, mortality from, reduced by various 
 sanitary improvements, 895 
 
 — prevalence of, among negroes, 187 
 
 — treatment of, by compressed air, 644 
 Physical education, 539 
 
 advantages of, 540 
 
 • — — bodily development caused by, 543 
 
 constituent parts of, 541 
 
 efi'ects of, on muscular and nervous 
 
 systems, 552 
 
 on comeliness and comfort, 556 
 
 — — tissues and organs, 553 
 
 elements of, 606 
 
 exercise as a part of, 542 
 
 importance of, in elementary schools, 
 
 608 
 
 mental and moral effects of, 558 
 
 rules for conducting, 607 
 
 training and specific exercises as parts 
 
 of, 572 
 Pig-keeping, nuisance due to, 919 
 Pipes tor drains, 765 
 
 rain-water, 773 
 
 soil, 773 
 
 — leaden, for distribution of water, 448 
 Plague and pestilence connected with im- 
 purity of air, 651 
 
 • ■ mortality from, in London (1665), 
 
 651 
 
 Plants, green, influence of, in purification 
 of river-water, 265, 851 
 
 Plasmodium malaricB, 352 
 
 Plethysmograph, use of, to detect effects of 
 cold applications, 634 
 
 Pleuro-pneumonia, flesh of animals suffer- 
 ing from, 447, 501 
 
 Plosz and Maly on nutritive value of 
 albumoses and peptones, 397 
 
 Pneumonia, use of cold baths in, 634 
 
 Pole, Dr., on daily quantity of water neces- 
 sary for domestic use, 244 
 
 PooRE, Dr. Gr. v., on disease-causing organ- 
 isms in soil, 316 
 
 Population, aggregation of, as causing 
 disease, 653 
 
 — — — — connected with hygiene of 
 dwellings, 656 
 
 — increase of, in recent years, 658 
 
 Pork, mischievous results from eating, 505 
 
 Porter-Clark, process for removing ex- 
 cessive hardness of water, 253 
 
 Portland cement, nuisance arising from 
 manufacture of, 941 
 
 Potatoes as a food, 471 
 - examination of, 471 
 
 — specific gravity of, mode of taking, 472 
 Potter's lung, 7 
 
 ' Poudrette ' manure, 921 
 
 Poultry-keeping, nuisance arising from, 
 899 
 
 Power, Mr. W. H., on acidity of water as 
 influencing action on lead, 257 
 
 diphtheria due to contami- 
 nated milk, 338 
 
 lead-poisoning and bacteria 
 
 in water, 370 
 
 spread of disease from small- 
 pox hospitals, 753 
 
 Priessnitz on treatment of disease by cold 
 water, 618 
 
INDEX 
 
 1007 
 
 PKI 
 
 Prison at Nanterre, plan of, 694 
 
 at Wormwood Scrubs, description of, 
 
 693 
 Prisons, diet for, 416 
 
 — condition of, in last century, 690 
 Privies and middens, rules for construction 
 
 of, 813 
 Proteids as food, 393 
 
 — composition of, 394 
 
 Public health, improvement of, due to 
 sanitary works, 890 
 
 QuETELET on diumal variations of elec- 
 tricity, 199 
 
 Badiation, solar, means of determining, 
 172 
 
 — terrestrial, means of determining, 173 
 Kags, storage of, causing a nuisance, 924 
 Eain, effects of, upon soil, 312 
 Eainfall and rain-gauges, 167 
 
 — as influencing amount of CO2 in soil, 
 321 
 
 climate, 191 
 
 — relation between, and cholera, 343 
 
 — rules for observing, 168 
 Bain-water as a source of supply, 228 
 
 — collection and storage of, 229 
 
 — impurities in, 228 
 
 — purification of, 231 
 
 — rules as to yield of, 231 
 
 — separator for obtaining pure, 229 
 
 — variations in amount of, 231 
 Eatteay on diminution of respiration as a 
 
 result of heat, 189 
 
 — on sea voyages in relation to health, 218 
 Eefuse, conservancy systems for dealing 
 
 with, 812 
 
 — conversion of, into manure, 820 
 
 — cremation of, 821 
 
 — definition of, 807 
 
 — disposal and methods of removal of, 
 807 
 
 — household, cremator furnace for, 810 
 
 Destructor furnace for, 809 
 
 dustbins for, 808 
 
 iron pails for, 808 
 
 matters contained in, 808 
 
 to be excluded from, 809 
 
 temporary storage of, 808 
 
 ultimate disposal of, 809 
 
 — manufacturing, disposal of, 889 
 
 — middens, as receptacles for, 812 
 
 — waste waters in, 811 
 Eespiration, effects of, upon air, 15 
 Eheumatic fever, use of cold baths in, 634 
 Eheumatism, prevalence of, due to soil, 355 
 Eice as a food, 466 
 
 Eice-starch, grains of, 454 
 EicHAED Febkes, MM., recording baro- 
 meter, 156 
 
 thermometer, 164 
 
 Bickets, causes of, 381 
 
 — geographical distribution of, 382 
 
 — of malarious origin, 382 
 Eiding as an exercise, 577 
 
 Elvers as a source of water-supply, 242 
 
 — pollution of, by effluent sewage, 864 
 
 SCH 
 
 Bivers, pollution of, by sewage, 851 
 Eoadway ventilators for sewers, 844 
 EoiiEiiTS, Mr. C, on development of body, 
 543 
 
 — Mr. C. G., separator for obtaining pure 
 rain-water, 229 
 
 — Sir W., on digestion as retarded by food- 
 accessories, 478 
 
 influence of alcohol on diges- 
 tion, 476 
 Bobinson's anemometers, 175 
 Eol)urite, effecta of fumes of, 9 
 liochdale pail for removal of excreta, 814 
 Bocks and soil, relation between, 309 
 
 — action of waters and gases upon, 312 
 
 — classification and composition of, 310 
 
 — stratified, 311 
 
 Eomford, statistics of sewage-farm at, 881 
 
 Boofs, construction of, 662 
 
 Eooms, local circulation of air in, 85 
 
 — ventilation of, 91 
 Boots' blowing-machine, 81 
 BosENBACH on micro-parasite of tetanus, 
 
 371 
 
 Boux and Yeesin on the bacillus of diph- 
 theria, 339 
 
 Bowing and sculling as forms of exercise, 
 582 
 
 muscles involved in, 583 
 
 Eugby School, sanatorium at, 756 
 
 Eunning as an exercise, 575 
 
 Eutgees, Dr., on nutritive value of pro- 
 teids, 408 
 
 Butheefokd's minimum thermometer, 161 
 
 Eye as a food, 466 
 
 — ergot of, 467 
 
 Sakhaeofe on organisms in blood of mala- 
 rious cases, 352 
 'Salisbuet, Dr., on production of measles 
 from fungi, 8 
 
 Salts in vegetable foods, 454 
 
 — taken in as food, 406 
 Sanatoria for schools, 755 
 
 accommodation necessary in, 757 
 
 Sand, effect of, in filtration, 251 
 
 Sandeeson, Dr. B., on effect of time on or- 
 ganic impurities in soil, 660 
 
 ventilation of small-pox hos- 
 pitals, 763 
 
 Sanitary works, influence of, upon public 
 health, 890 
 
 Saundees, Dr. Sedgwick, on cremation of 
 refuse, 821 
 
 Saussuee hygrometer, 166 
 
 — on connection between goitre and soil- 
 dampness, 383 
 
 Scarlatina, epidemic of, caused by disturb- 
 ing churchyard soil, 12 
 
 — question as to transmission of, by milk, 
 432 
 
 ScHLEicH on increase of urea after hot 
 
 baths, 626 
 ScHLosiNG and Muntz on nitrification of 
 
 soil, 314 
 and Waeington on action of 
 
 nitrifying organisms on sewage, 871 
 Schmidt Mulheiji, on anthrax bacilH, 376 
 
1008 
 
 HYGIENE 
 
 SCH 
 
 Schools, absence of system in construction 
 
 of, 702 
 
 — arrangements for physical exercises in, 
 703 
 
 washing in, 711 
 
 windows in, 708 
 
 — baths in, 711 
 
 — best forms of ventilation for, 707 
 
 — closet accommodation in, 712 
 best forms of, for, 713 
 
 — cost of warming and ventilating, 142 
 
 — cottage-home system for, 702 
 
 — day-rooms in, 708 
 
 — dissemination of disease by, 701 
 
 — dormitories in, 709 
 flooring of, 710 
 
 with cubicle system in, 710 
 
 — hygiene of, 700 
 
 — infimiaries and sanatoria for, 755 
 
 — lavatories in, 710 
 
 — poor-law, 703 
 
 block-plans for, 705 
 
 cottage-home systems for, 705 
 
 history of, 704 
 
 ophthalmia in, 704, 760 
 
 rate of sickness in, 703 
 
 — residential, chief hygienic defects in, 
 706 
 
 lamidries for, 714 
 
 — space for each child in, 707 
 
 — swimming-baths in, 712 
 
 ScHULZE on determination of nitric acid in 
 
 air, 97 
 Scoresbt-Jackson on effects of low tem- 
 perature during winter, 217 
 Scott on causes determining precipitation 
 
 of rain, 191 
 
 estimating force of wind, 177 
 
 frequency of winds in various regions, 
 
 197 
 Scurvy in connection with food, 474 
 ea, discharge of sewage into, 853 
 ea-voyages, effects of, 218, 220 
 Seeds, oily, percentage composition of, 470 
 ell.\e's patent (A B C) process for dealing 
 
 with sewage, 866 
 Senator on reduction of temperature by 
 
 exposure to cool air, 625 
 Septicaemia from mud and dirt getting into 
 
 wounds, 797 
 Sewage, ABC process of precipitation of, 
 
 866 
 
 — alum used to precipitate, 858 
 
 — Amines process for dealing with, 867 
 
 — applied to soil, nuisance caused by, 873 
 
 — chemical composition of, 855 
 
 — clarification of, 860 
 
 — clarified, applied to land, 872 
 
 — crude, discharge of, into sea, 853 
 
 — deodorants combined mth precipitation 
 of, 867 
 
 — disposal of, 850 
 
 — distribution of, over large areas, 873 
 
 — drains and tanks for sub-irrigation by, 
 887 
 
 — effects of, on fresh running water, 851 
 health, 885 
 
 — effluent, injuries to fish by, 865 
 nuisance from, 864 
 
 pollution of rivers by, 865 
 
 SEW 
 
 Sewage emanations in air, eiJects of, 11 
 
 — filter press for dealing with, 861 
 
 — filtration of clarified effluent from, 866 
 through soil, 870 
 
 — formation of sludge from, 859 
 
 — influence of, on fish in rivers, 853 
 organisms in soil upon, 871 
 
 — intermittent downward filtration of, 872 
 
 — iron protosulphate to precipitate, 859 
 
 — irrigation of land by, 873 
 
 — lime used to precipitate, 858 
 
 — nitrification of, in soil, 262 
 
 — nitrogen in, taken up by crops, 881 
 
 — pollution of tidal waters by, 852 
 — water by, 262 
 
 — precipitation of, by electrolysis, 868 
 lime, alum and iron, 858 
 
 — preparation of land for reception of, 871 
 
 — purification and utilisation of, 854 
 
 — question whether wasted if discharged 
 into sea, 853 
 
 — siphon arrangements for sub-irrigation 
 by, 888 
 
 — soils best suited for reception of, 871 
 
 — straining, subsidence and precipitation 
 of, 857 
 
 — subsoil irrigation by, 886 
 
 — tanks for dealing with, 861 
 
 — value of, 856 
 
 to different soils, 881 
 
 Sewage-farms, absence of nuisance from, 
 885 
 
 — capital required for, 879 
 
 — catch-water system for, 876 
 
 — character of effluent water from, 882 
 
 — crops best suited for, 878 
 
 — difficulties of, due to excess of water, 
 876 
 
 frost, 877 
 
 — evaporation of water from, 882 
 
 — extent of, 875 
 
 ~ filter-beds for, 877 
 
 — health of cattle not injured by, 885 
 men employed on, 885 
 
 — management of, 874, 878 
 
 — nitrogen recovered by crops of, 881 
 
 — outbreak of dysentery near, 885 
 
 — pane and gutter system for, 876 
 
 — results of, upon sewage, 883 
 
 — ridge and furrow system for, 875 
 
 — rye-grass gl•o^vn on, 878 
 
 — sewage-fungus in channels of, 884 
 
 — soils best suited for, 874 
 
 — statistics of, at Romford, 881 
 Wimbledon, 884 
 
 - — success attained by, 880 
 ■ — under-drainage of, 875 
 
 — use of osier beds in, 876 
 Sewage-zone, formation of, in rivers, 852 
 Sewerage, Berlier system of, 850 
 
 — combined system of, 830 
 
 — improved and diminished mortality from 
 phthisis, 356 
 
 — Liernur system of, 849 
 — ■ separate system of, 833 
 
 advantages and disadvantages 
 
 of, 886 
 
 — Shone system of, 847 
 
 Sewers, causes producing movements of air 
 in, 842 
 
INDEX 
 
 1009 
 
 SEW 
 
 Sewers, composition of air of, 840 
 
 — contamination of houses by air from, 
 842 
 
 — deoclorisation of air escaping from, 845 
 
 — effects of inhalation of air of, 841 
 
 — flushing and inspection of, 8;-J7 
 
 — forms of, 831 
 
 — formulte to calculate discharge from, 833 
 
 — laying of house-drains to, 834 
 
 — manhole and ventilator for, 835 
 
 — materials used in construction of, 831 
 
 — means of access to, 838 
 
 — microbes in air and contents of, 840 
 
 — original function of, 828 
 
 — outfall, 847 
 
 — passage of infectious matters into and 
 from, 839 
 
 — pipe, ventilation of, 846 
 
 — principles of construction of, 830 
 
 — reduced mortality from phthisis since 
 construction of, 829 
 
 — rush of storm-water into, 832 
 
 — self-cleansing of, 831 
 
 — shafts for ventilating, 844 
 
 — sizes and dimensions of, 832 
 
 — subsoil drainage, effected by, 829, 833 
 
 — surface roadway, ventilators for, 844 
 
 — ventilation of, 839, 844 
 
 by rain-water and soil pipes, 843 
 
 . Sheaeman, Mr., on football as an exercise, 
 
 606 
 Sherborne School, sanatorium of, 758 
 Ships ' Castalia ' and ' Atlas ' as small-pox 
 
 hospitals, 754 
 Shoddy, dust from manufacture of, causing 
 
 disease, 7 
 
 — manufacture of, 510 
 Shoes, points desirable in, 529 
 Shone system of sewerage, 847 
 
 Shops, sanitary conditions and defects in, 
 
 672 
 Shot, manufacture of, 960 
 Silica, estimation of, in water, 293 
 • — in water, influencing action on lead, 257 
 Silk as material for clothing, 510 
 Simon, Sir J., on filth-diseases and their 
 
 prevention, 663 
 on frequency of lung-affections in 
 
 England, 355 
 Sinks, grease from, methods of dealing 
 
 with, 775 
 
 — materials and- arrangements for, 775 
 Six's registering thermometer, 160 
 Skating as an exercise, 576 
 
 Skeleton, time of completion of various 
 
 parts of, 544 
 Skill, exercises involving, 610 
 Skin, effects of exercise upon, 557 
 
 — question as to absorption of fluids and 
 salts by, 627 
 
 Skipping as an exercise, 576 
 
 Slates as materials for roofs, 662 
 
 Slaughter-house used as a hospital, salubrity 
 of, 720 
 
 Slaughter-houses and their administra- 
 tion, 977 
 
 — construction of, and defects in, 981 
 
 — inspection of, 991 
 
 — nuisances arising from, 997 
 
 — public, arrangements for, 987 
 
 VOL. I. 
 
 SOI 
 
 Slaughter-houses, rules for control and 
 
 management of, 982 
 Sludge, formation of cake from, 861 
 from sewage, 850 
 
 — methods of dealing with, 864 
 
 — value of, 863 
 
 Small-pox hospitals, spread of disease from, 
 753 
 
 ventilation of, 763 
 
 Smell, sense of, as a guide to impurity of 
 air, 23 
 
 Smiiike, Mr. S., on buildings for artisans, 678 
 
 Smith, Dr. A., on detection of micro-organ- 
 isms in water, 296 
 
 on effects of CO,^ in air, 9 
 
 on estimation of C0._, in air, 25 
 
 — Dr. W. R., on influence of microphytes 
 on lead, 370 
 
 on micro-organisms in London 
 
 water, 298 
 Smoke-test for drains, 776 
 Snow, crystals of, 178 
 Snow, Dr., on cholera in Soho traced to 
 
 polluted water, 268 
 on diarrhcea as cause of infantile 
 
 mortality, 364 
 Soap test for hardness of water, 290 
 
 — waste of, from use of hard water, 260 
 Soaps, nuisance due to manufacture of, 912 
 Socks and stockings, points desirable in, 
 
 526 
 Sodium chloride, as a constituent of food, 
 
 400, 406 
 Soho, cholera in, due to polluted water, 268 
 Soil, air in, 317 
 
 — alluvial and drift, 312 
 
 — analysis of, 388 
 
 -^ and rock, relation between, 809 
 
 — animal and vegetable matter in, 311 
 
 — as a cause of diarrhcea, 362 
 
 — as a cause of rheumatism, 355 
 
 — as a filter for bacteria, 314 
 
 — as distinguished from subsoil, 399 
 
 — as modified by work of animals, 313 
 
 — bacteriological examination of, 388 
 
 — best suited for reception of sewage, 871 
 
 — carbon-dioxide in air of, 318 
 
 — chemical examination of, 385 
 
 — cholera from contamination of, 339 
 
 — decomposition in, 316 
 
 — definition and composition of, 309 
 
 — diphtheria from contamination of, 337 
 
 — disease-causing organisms in, 317 
 
 — diseases connected with conditions of, 
 331 
 
 — dry, sandy, and attacks of ague, 350 
 
 — effects of rain upon, 312 
 
 — estimation of amount of air in, 323 
 
 ^ organic matter in, 386 
 
 soluble matter in, 386 
 
 — temperature of, 330 
 
 — filtration of sewage through, 870 
 
 — formation of, from stratified rocks, 311 
 
 — gain of heat by, 329 
 
 — geological characters of, and diarrhoea, 
 366 
 
 — influence of bacteria upon, 313 
 on health, 309 
 
 — lead-poisoning, related to conditions of, 
 369 
 
 3T 
 
1010 
 
 HYGIENE 
 
 SOI 
 
 Soil, loss of heat by, 329 
 
 — moisture in, and prevalence of diarrhoea, 
 3G4 
 
 — nitrification of, due to organisms, 314 
 
 — nitrogen present in, 320 
 
 — oxidation of organic substances in, 315 
 
 — phj'sical examination of, 385 
 
 — putrefactive changes in, 319 
 
 — relation of dampness of, to phthisis, 
 355, C60 
 
 — to anthrax, 375 
 
 calculous disease, 378 
 
 -■ cancer, 377 
 
 dysentery, 307 
 
 — goitre and cretinism, 381 
 
 — — malaria, 347 
 
 rickets, 381 
 
 — temperature of, 327 
 
 — ■ as influencing changes in, 316 
 
 — tetanus due to micro-ijarasites in, 371 
 
 — typhoid from contamination of, 333 
 
 — ventilation of, 310 
 
 — water in, 324 
 Soil-pipes, construction of, 773 
 
 — position of, 774 
 Soldiers, daily diet of, 414 
 
 Soups and broths, constituents of, 423 
 Spaces, open, necessity for, in towns, 654 
 Speed, exercises involving, 610 
 Spiegelberg on dilution of cows' milk for 
 
 children, 429 
 Spirits, composition of, 483 
 
 — manufacture of, 482 
 
 Sponges, preparation and cleansing of, for 
 
 surgical purposes, 793 
 Sports and games, outdoor, mental and 
 
 moral effects of, 559 
 Spray, carbolic, use of, in treating wounds, 
 
 788 
 Spring-waters, classification of, 235 
 
 — intermittent supply of, 230 
 Springs, cold, places celebrated for, 630 
 
 — warm, places celebrated for, 035 
 
 St. Saviour's Union Infirmary, Champion 
 
 Hill, plan of, 743 
 Stanford's sea-weed charcoal for closets, 
 
 817 
 Starches, commercial, composition of, 451 
 
 — identification of, by microscope, 451 
 
 — structure of grains of, 452 
 Starvation, phenomena of, 425 
 Stature, average, at all ages, 544 
 Steel-grinders, liability of, to lung-disease, 
 
 7 
 Steele, Dr., on results of Listerism at 
 
 Guy's Hospital, 799 
 Stevenson's thermometer-screen, 170 
 Stiffness, muscular, due to exercise, 505 
 Stomach, digestion of articles of diet in, 
 
 419 
 Storage of water, Pole and Hawkslet's 
 
 calculations for, 240 
 Storm-water, rush of, into sewers, 832 
 Stoves for warming, 120 
 Stratus, 178 
 Streams, purification of, by animal and 
 
 vegetable life, 205 
 Street-sweeping and cleaning, importance 
 
 of, 925 
 Strength, bodily, advantages of, 540 
 
 THE 
 
 Strength, exercises involving, 010 
 
 Subsoil, drainage of, effected by sewers 
 829, 833 
 
 Sugar, composition of, 454 
 
 Sulphurous acid, morbid efi'ects of inhala- 
 tion of, 938 
 
 Sunshine, methods of recording, 171 
 
 Sunstroke, 204 
 
 Superphosphate manure, nuisance due to, 
 920 
 
 Surface-water passing into drains, traps for, 
 770 
 
 Suspended matters in air, 4, 6 
 
 Swimming as an exercise, 577 
 
 Swimming-baths, arrangements for, in 
 schools, 712 
 
 Swine-fever, flesh of animals suffering from, 
 503 
 
 Symons, Mr. J. G., on mean rainfall, 233 
 
 TcBniad(2 in meat, 498 
 Talard, M., on method of emptying cess- 
 pools, 824 
 Tanks for dealing with sewage, 801 
 Tanneries, nuisance arising from, 917 
 Tanning and tawing, processes of, 512 
 Tatham, Dr. J., on prevalence of tubercular 
 
 disease in back-to-back houses, 684 
 Tea, adulterations and examination of, 489 
 
 — composition of, 489 
 
 — effect of, on digestion, 470, 478 
 
 — physiological action of, 488 
 Temperature as influenced by warm ocean 
 
 currents, 200 
 — ■ — influencing prevalence of diarrhoea, 
 302 
 
 — correction of barometer for, 155 
 
 — of earth, general features and measure- 
 ment of, 173 
 
 — suitable in various buildings, 117 
 
 — variations of climate due to, 188 
 Terling, outbreak of typhoid fever at, 209 
 Terron, M., on condition of Hotel-Dieu in 
 
 last century, 720 
 Testing drains, methods of, 770 
 Tetanus, bacilli of, 372 
 
 — due to micro-parasites in soil, 371 
 
 — influence of predisposition to, 374 
 
 — theory of equine origin of, 373 
 Thames as a source of water supply, 242 
 Thatch as a material for roofs, 662 
 Theine, physiological action of, 488 
 Theobromine, physiological action of, 488 
 ' Therm,' meaning of term, 35 
 Thermometers, conditions influencing ac- 
 curacy of, 159 
 
 — dry and wet bulb, 165 
 
 — Glaisher's stand for, 169 
 
 — Immisch's, 163 
 
 — Montsouris stand for, 170 
 
 — Negretti and Zambba's maximum, 163 
 
 — ordinary, 158 
 
 — Phillips' maximum, 102 
 
 — registering, forms of, 159 
 
 — Kichard's recording, 104 
 
 — Eutherfokd's minimum, 161 
 
 — Six's, 160 
 
 — Stevenson's screen for, 170 
 
INDEX 
 
 1011 
 
 THO 
 
 Thoene, Dr., on checks to spread of cholera, 
 340 
 
 connection between phthisis and 
 
 drainage, 359 
 — outbreak of typhoid at Terming, 
 
 269 
 
 typhoid propagated by water, 209 
 
 Thobpe, John, design for dwelHng-house 
 
 (Sir J. Soane's Museum), 069 
 Thbesh, Dr., on detection of nitrites in 
 
 water, 283 
 on estimation of dissolved oxygen 
 
 in water, 294 
 Thunderstorms, instructions for observing, 
 
 179 
 Thobsfikld, Dr., on connection between 
 
 diphtheria and dampness of houses, 338 
 TicHBORNE, Mr., on organic matter in 
 
 street-dust, 5 
 Tidy, Dr., on action of water containing 
 
 silica on lead, 257 
 — detection of organic matter in 
 
 water, 288, 301 
 
 ■ — potability of river-water, 265 
 
 self-puriiication of flowing water, 
 
 243, 264, 266 
 Tiles as materials for roofs, 662 
 Time, local, calculated from Greenwich 
 
 time, 174 
 TissANDiER, M,, on experiences of balloon 
 
 ascent, 193 
 Tissues and organs, effects of exercise 
 
 upon, 553 
 Tobin's tubes, 90 
 ToLLET, M., on barracks in France, 696 
 
 plan of St. Denis Hospital, Paris, 740 
 
 ToMKiNS, Dr., on connection between 
 
 temperature and diarrhoea, 364 
 Towns, amount of water necessary for, 245 
 
 — conditions necessary for healthfulness 
 of, 652 
 
 — English, reduction in death-rate of, 892 
 
 — necessity for open spaces in, 654 
 Training, physical, effects of, on non- 
 commissioned officers, 548 
 
 — systematic, principles of, 572 
 Trapeze, use of, in gymnastics, 602 
 Traps, for drains, 768 
 
 Trees, as barriers to progress of malaria, 
 
 354 
 Trichina spiralis in meat, 499 
 Trichiniasis from diseased pork, 446 
 Tricycle, description of, 587 
 Tricycling, advantages of, 592 
 Tripe, ox-feet, &c., nuisance due to boiling 
 
 of, 901 
 Trough-closets, for institutions, 774 
 Trousers, points desirable in, 524 
 Trunk, proportions of, during growth, 550 
 Tubercular disease, prevention of, in back- 
 to-back houses, 684 
 Tuberculosis, bacillus of, 366 
 
 — in cows, affecting milk, 432 
 
 — meat of animals suffering from, 448, 499 
 
 — prevention of, 361 
 
 Tubes, ventilating, loss due to air-friction 
 
 in, 66 
 Turkey-red, preparation of blood for, 906 
 ToENEE, Mr. Ernest, on system of heating 
 
 water for baths, 712 
 
 VEN 
 
 TuENEK, Mr., on connection between tem- 
 perature and diarrhoea, 363 
 
 Tyne Port Sanitary Authority, floating 
 hospital of, 752 
 
 Type-setters, danger of lead-poisoning 
 among, 903 
 
 Typhoid fever, bacillus of, 336 
 
 from polluted soil, 333 
 
 mortality from, 209 
 
 propagated by water, 209 
 
 reduction in mortality from, 893 
 
 ■ use of cold baths in, 033 
 
 Typhus fever, epidemic at Greenock (1805), 
 from overcrowding, 053 
 
 use of cold baths in, 034 
 
 United States, water supply to cities of, 250 
 Urea and uric acid, excretion of, 393, 398 
 Urinals, arrangements for, 775 
 
 Vabicose veins, exercise as a cause of, 570 
 Varnishes, nuisance connected with manu- 
 facture of, 928 
 Vaulting-horse, use of, in gymnastics, 003 
 Vegetable decomposition connected with 
 
 attacks of ague, 350 
 Vegetables, effects of cooking upon, 422 
 
 — succulent, used as food, 472 
 Ventilation, barometric pressure and tem- 
 perature as influencing, 73 
 
 — causes available to produce motion of 
 air for, 71 
 
 — changes in volume of air during, 53 
 
 — conditions for efficient, 116 
 
 — construction of chimneys as influencing, 
 97 
 
 — continuity of flow of air in, 53 
 
 — effect of adjoining rooms upon, 113 
 artificial lighting upon, 114 
 
 — estimate of volume of air passing in, 58 
 work spent in, 56 
 
 — general circulation of air in, 55 
 theory of, 52 
 
 — in summer and winter, 115 
 
 — influence of gas-jets upon, 100 
 
 — influenced by differences of pressure, 55 
 
 — investigation of system of, 104 
 
 — laws of, 53, 58, 68 
 
 — local distribution of air in, 107 
 
 — loss due to air friction in, 65 
 
 — motion of air in special cases of, 89 
 
 — object of, 41 
 
 — odorous substances for testing, 108 
 
 — of closed room with heating apparatus, 
 91 
 
 room with single opening, 91 
 
 two inlets and two outlets, 102 
 
 outlets and one inlet, 100 
 
 separate openings, 94 
 
 sewers, 839, 844 
 
 — open fire as affecting, 95 
 
 — position of flues suited for, 118 
 
 — pressure differences as a test of, 106 
 
 — produced by blowing machines, 81 
 fans, 77 
 
 hot-aii and smoke flues, 82 
 
 local circulation of air, 85 
 
 — proportion between inlets and outlets 
 for, 121 
 
1012 
 
 HYGIENE 
 
 VEN 
 
 Ventilation, qualitj' of air required for, 117 
 
 — relative advantages of systems of, Hi 
 
 — resistance of ducts to air in, CO, 04 
 
 — ' steady ' motion of air in, 53 
 
 — systems of, in public buildings, 145 
 
 — tested by anemometer, 104 
 
 — through orifices, steadiness of flow in, 
 56 
 
 tubes, motion of air in. 59 
 
 — ' vacuum ' and ' plenum ' methods of, 73 
 
 — wind as intiuencing, 73 
 
 Vekxeuil on equine origin of tetanus, 373 
 Vernier for barometers, use of, 154 
 Vessels carrying cattle, disinfection of, 978 
 Vicarages and rectories, sanitary condition 
 
 of, C70 
 ViEROKDT on growth during childhood, 407 
 Vinegar, adulterations of, 473 
 
 — uses of, 473 
 
 VoELCKEK, Dr., on value of sewage, 863 
 VoiT on composition of workmen's diet, 
 
 415 
 
 diet for men during work, 405 
 
 proportion of fat to carbo-hydrates 
 
 in diet, 409 
 
 Wage-eakning classes, dwellings for, 673 
 
 — Acts dealing with, 674 
 
 Walking as an exercise, 573 
 Walls, external, of dwellings, 661 
 
 — of hospitals, materials for, and cleaning, 
 781 
 
 Wanklyn, i\Ir., on detection of nitrates in 
 water, 281 
 
 ■ — organic matter in water, 
 
 285 
 
 — imiDure water as a cause of diar- 
 rhoea, 271 
 
 • — standards of organic purity of 
 
 water, 303 
 
 Wards for isolating infectious cases, 794 
 
 — isolation, purification of, 795 
 Waeixgton, on nitrification of sewage by 
 
 soil, 262, 314 
 Warming, apparatus for, 122 
 
 — and ventilating, combinations of appa- 
 ratus for, 141 
 
 problems relating to, 33 
 
 — close stoves for, 126 
 
 — distribution of heat for, by air, 131 
 , by water, 132 
 
 gas fires and stoves for, 128 
 
 — heating surface required for, 136 
 
 — improved fire-grates for, 124 
 
 — in relation to ventilation, 138 
 
 — relative advantages of systems of, 143 
 
 — values of fuel used for, 122 
 Waere, Kev. E., on rowing strokes, 582 
 value of sliding seats in boats, 
 
 581 
 Waste-pipes cut off from gulleys, 771 
 
 — waters in refuse, 811 
 
 Water, absorption of, by skin, 627 
 
 — acid reaction of, due to microphytes, 370 
 
 — action of, on lead, 256 
 
 — albuminoid ammonia in, 285 
 
 — amount required for baths and closets, 
 244 
 
 for domestic purposes, 243 
 
 \\'AT 
 
 Water, amount required for hospitals, 245 
 for various uses in towns, 245 
 
 — analysis of, 274 
 
 — bacteriological examination of, 293 
 
 — bibliography of, 305 
 
 — changes in, due to cold and heat, 226 
 
 — chlorine, estimation of, in, 278 
 
 — cholera propagated by, 267 
 
 — clarification of, 250 
 
 — classification founded on organic purity 
 of, 300, 302 
 
 quality of, 254 
 
 softness of, 262 
 
 — cold, efi'ects of local application of, 624 
 
 — collection of, for examination, 274 
 
 — colour and appearance of, 275 
 
 — composition and physical propeiiiies of, 
 225 
 
 — constant supply of, 247 
 
 — contamination of, by lead, 256 
 
 — dangerous, 300 
 
 — deposits in, microscopical examination 
 of, 276 
 
 — detection of chromium in, 294 
 of iron in, 293 
 
 — - of lead and copper in, 289 
 of manganese in, 293 
 
 — determination of action of, upon lead, 
 295 
 
 — diarrhcea due to, 271 
 
 — disorders due to hardness of, 259 
 
 — distribution of, 248 
 heat by, 132 
 
 — double supply of, 249 
 
 — dysentery due to, 272 
 
 — effects of hardness of, 258 
 insufficient supply of, 245 
 
 — estimation of dissolved oxygen in, 294 
 hardness of, 290 
 
 nitrates in, 279 
 
 organic matter in, 283, 299, 304 
 
 — examination of, 295 
 
 — filtration of, for household purposes, 258 
 — • for public supplies, 251 
 
 — from deep Artesian wells, 240, 255 
 underground tanks near rivers, 238 
 
 — gases in, 275 
 
 — goitre, due to, 273 
 
 — good drinking, characteristics of, 298 
 
 — ground or subsoil, 325 
 
 — hard, drawbacks connected with, 259 
 
 — hardness of, 258, 304 
 
 — hot, effects of local application of, 627 
 
 — impure, effects of, 266 
 
 — malaria from, 272 
 
 — metallic contamination of, 256 
 
 — observations on various constituents of, 
 303 
 
 — odour of, 275 
 
 — parasitic organisms found in, 274 
 
 — pipes for distribution of, 248 
 
 — pollution of, by organic matter, 262 
 
 — prevention of, from dissolving lead, 248 
 258 
 
 waste of, 249 
 
 — quality of, from various sources, 255 
 
 — quantity of, required to flush closetB, 
 664 
 
 — rain, 228 
 
 — reaction of, 277 
 
 i 
 
INDEX 
 
 1013 
 
 WAT 
 
 Water, river, 242, 255 
 
 contamination of, 242 
 
 pollution of, from mines and manu- 
 factures, 243 
 
 question as to spontaneous purifica- 
 tion of, 242, 265 
 
 — running, effects of sewage on, 850 
 
 — self -purification of, 263 
 
 — soft versus hard, 260 
 
 — softness of, 260 
 
 — solvent powers of, 227 
 
 — sources of supply of, 228 
 
 — spring, 235, 255 
 advantages of, 241 
 
 intermittent supply of, 286 
 
 — standard solutions for analysis of, 295 
 
 — storage of, 246 
 
 and distribution of, in dwellings, 666 
 
 near habitations, 247 
 
 — subsidence as a means of clarification 
 of, 251 
 
 — suspended matters in, examination of, 
 275 
 
 — suspicious, as regards health, 300 
 
 — taste of, 277 
 
 — total solids in, 277, 304 
 
 — turbidity of, 275 
 
 — typhoid fever propagated by, 269 
 
 — underground, through fissures in chalk, 
 239 
 
 — upland surface, 232, 255 
 characteristics of, 233 
 
 — — — classified according to organic 
 purity, 300 
 
 composition of, 235 
 
 — uses of, as a food, 400 
 
 — vapour of, in atmosphere, 4, 44, 226 
 
 — well, 237, 255 
 
 impurities in, 237, 241 
 
 polluted by sewage, 262 
 
 Water-carriage system of removal for 
 
 excreta, 827 
 Water-closets in dwelling-houses, best 
 
 forms of, 664 
 
 ventilation of, 664 
 
 position of, in cottages, 681 
 
 trough form of, for institutions, 774 
 
 Water-gas, dangers connected with, 943 
 Water -proofing, receipts for, 534 
 Water-supply, objections to intermittency 
 
 of, 667 
 ' Weathering,' process of, in soil formation, 
 
 311 
 Weavers, liability of, to lead poisoning, 968 
 Webee, Dr., on diminished cutaneous 
 
 sensibility after cold bath, 623 
 Weight, average, at all ages, 544 
 Wells, driven, or tube (Abyssinian), 288 
 
 — near the sea, 238 
 
 — shallow and deep, water-supply from, 
 237 
 
 ZIN, , 
 
 Wells, shallow, impurities in water from, 
 241 
 
 — water from, polluted by sewage, 202 
 West Indies, effects of climate of, on 
 
 Europeans, 188 
 Wheat as a food, 457 
 
 — composition of, 456 
 
 — starch, grains of, 453, 455 
 Wheaten-flour, entire (wholemeal), 457 
 
 — kinds and ([uality of, 456 
 
 White, Mr. W. H., on arrangement of 
 
 dwellings, 671 
 White-lead factories, dangers of working in, 
 
 959 
 Williams, Dawson, on connection between 
 
 temperature and diarrh«;a, 365 
 Willis-Bund, Mr., on injuries to fish from 
 
 effluent sewage, 865 
 Wilson, Dr. J. B., on goitre in India, 273 
 Wimbledon sewage farm, results at, 884 
 Wind as influencing climate, 196 
 ventilation, 73 
 
 — local varieties of, 198 
 
 — means for ascertaining direction of, 174 
 force or velocity of, 175 
 
 — trade and anti-trade, 197 
 Wines, effect of ethers in, 487 
 on digestion, 477 
 
 — light, composition of, 481 
 
 — sweet, 482 
 
 WiNTERNiTz on cffccts of local application 
 
 of cold, 624 
 Wool as a material for clothing, 509, 517 
 Wool-sorters' disease, 931 
 regulations at Bradford for prevention 
 
 of, 932 
 Work as influencing diet, 407 
 Workhouses, buildings comprised in, 716 
 
 — diets for persons in, 416 
 
 — hospital for, 742 
 
 — minimum space in dormitories of, 717 
 sick-wards of, 718 
 
 — necessary points in construction of, 716 
 
 — old plans of and defects in, 715 
 
 — sketch of history of, 715 
 Working classes, diet of the, 415 
 Wormwood Scrubs, description of prison 
 
 at, 693 
 
 Yellow fever in hot climates, 206 
 York County Hospital, results of deficient 
 ventilation in, 721 
 
 Zagiell, Prince, on absence of CO2 in air 
 
 of desert, 211 
 ZiBMssEN on tepid baths gradually cooled, 
 
 633 
 Zinc, dangers to workers in, 973 
 — uses of, in industrial arts, 973 
 

 Srv 
 
 H^ 
 
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