Columbia (Bnitier^itp\%'i's- College of 3^f}^iimmii anb burgeons! From the Library of PROFESSOR PHILIP HANSON HISS 1868-1913 Donated by Mrs. Philip Hanson Hiss -; v ,'' (■ y Digitized by tine Internet Arciiive in 2010 witii funding from Open Knowledge Commons http://www.archive.org/details/manualofpractica1884park A MANUAL OF PRACTICAL HYGIENE BY EDMUND A. PARKES, M.D., F.R.S. LATE PEOFESSOE OP MILITARY HYGIENE IN THE ARMY MEDICAL SCHOOL ; MEMBER OP THE GENERAL COUNCIL OF MEDICAL EDUCATION ; FELLOW OF THE SENATE OF THE UNIVEESITT OF LONDON ; EMEBITUS PKOFESSOE OF CLINICAL MEDICINE IN UNIVERSITY COLLEGE, LONDON EDITED BY F. S. B. FRANgOIS DE CHAUMONT, M.D., F.R.S. FELLOW OF THE ROYAL COLLEGE OF SURGEONS OP EDINBURGH ; FELLOW AND CHAIRMAN OF COUNCIL OF THE SANITARY INSTITUTE OF GREAT BRITAIN ; PROFESSOR OP MILITARY HYGIENE IN THE ARMY MEDICAL SCHOOL FROM THE LAST LONDON EDITION WITH AN APPENDIX Giving the American Peactice in Mattees KELATma to Htgiene PBBPARED BY AND UNDER THE SUPERVISION OF FREDERICK N. OWEN CIVIL AND SANITARY ENGINEER TWO VOLUMES 11^ ONE Volume I. NEW YORK WILLIAM WOOD & COMPANY 56 & 58 Lapatette Place 1884 / OOPTBIOHT WILLIAM WOOD & COMPANY 1863 'Tl TROW'9 PRINTING AND BOOKBINDING COMPANY^ K£W TORK« PEEFACE TO THE SIXTH EDITION. In presenting the Sixth Edition of the " Manual of Practical Hygiene," I have endeavored to keep within much the same limits as in the previous edition, by omitting matter which had either become out of date or was no longer necessary. In this way space has been obtained for matter which the progress of science and the results of experience rendered it desirable to add. Some slight changes have been made, such as putting all the directions for making chemical solutions in one appendix at the end of Volume II., and uniting all the questions of disinfection and deodorization in one chapter. The prefaces to former editions have been omitted, as being no longer required. The index is as full as on the last occasion. F. DE CHAUMONT. WooLSTON Lawn, Southampton, March^ 1883. CONTENTS. PAGE INTRODUCTION ix BOOK I. CHAPTER I. Water • • 1 Section I. — Quantity and supply 2 Quantity for healthy men and animals ^ sick men 7 Collection 8 Storage 11 Distribution 14 Action on lead pipes 17 Section II.— Quality 19 Composition of drinking-water 19 Characters and classification of drinking-water 24 Origin of the impurities in drinking- wMer 24 Impurities of source . . 24 transit 27 storage 28 distribution . , • . 29 Section III. — Purification of water 30 Without filtration 30 With filtration ... 32 Section IV. — Effects of an insufficient or impure supply 39 Insufficient supply 39 Impure supply 40 Section V. — Examination of water for hygienic purposes 65 Collection 66 Coarser physical examination 67 Examination of suspended matters 69 Microscopical 69 Chemical 74 of dissolved matters 74 Qualitative 76 Quantitative 81 Section VL — Search after water 107 Supply of water to soldiers 107 VI CONTENTS. CHAPTER II. PAOB AIR 113 Section I. — Impurities in air 114 Suspended matters 115 Gaseous matters 121 Impurities in certain special cases = 122 Section II.— Diseases produced by impurities in air 133 supended impurities 133 gaseous impurities 138 co-existing impurities 143 CHAPTER III. Ventilation 157 Section I. — Quantity of air required 157 Section II. — Mode in which it should be given 164 Section III. — Means by which air is set in motion 168 Natural ventilation 168 Artificial ventilation 183 Extraction 183 Propulsion 188 Section IV. — Relative value of natural and artificial ventUation 190 CHAPTER IV. Examination of Am 191 Section I. — Measurement of cubic space 191 Section II. — Movement of air in the room 193 Section III. — Examination of the air 195 Section IV. — Application of foregoing rules 201 CHAPTER V. Food 203 Section I. — General principles of diet 203 Quantity of food 209 On the energy obtainable from food 210 On the relative value of food 217 The digestibility of food 219 Section II. — Diseases connected with food 221 CHAPTER VI. Quality, Choice, and Cookino op Food 225 Section I.— Meat 225 Section II.— Wheat 241 Section III. —Barley 268 Section IV.— Oats 268 Section V.— Maize and Rye 269 Section VI.— Rice 269 Section VII.— Millet, Buckwheat, etc , 270 CONTENTS. Vll PAGE Section VIII. — Leguminosse 371 Section IX. — Starches and Sugar 273 Arrowroots 373 Tapioca 273 Sago 273 Sugar 274 Section X. — Succulent vegetables 275 Section XI.— Milk 277 Section XII —Butter 285 Section XIII.— Cheese 289 Section XIV.— Eggs o 289 Section XV. — Concentrated and Preserved Food 290 CHAPTER VII. Bevekages and Condiments 294 Section I. — Alcoholic beverages 294 Beer , <, 294 Wine 301 Spirits 306 Alcohol as an article of diet 307 Section II. — Non-alcoholic beverages 327 Coffee 327 Tea 333 Cocoa 336 Section III. — Condiments 338 Vinegar 338 Mustard 339 Pepper 341 Salt . 343 Section IV. — Lemon and lime juice 343 CHAPTER VIII. Soils 346 Section I. — Condition of soil affecting health 346 Air in soil 346 Water in soil 348 Solid constituents 355 Malarious soils 362 Section II. — Examination of soil 364 Section III. — Method of examining a locality 367 Section IV. — Preparation of site 368 TNTRODUCTIOJSr. HTGiEisrE is the art of preserving health ; that is, of obtaining the most perfect action of body and mind during as long a period as is consistent with the laws of life. In other words, it aims at rendering growth more perfect, decay less rapid, life more vigorous, death more remote. This art has been practised from the earliest times. Before Hip- pocrates there were treatises on hygiene, which that great master evi- dently embodied in his incomparable works. It was then based on what we should now call empirical rules — viz., simply on observations of what seemed good or bad for health. Yery early, indeed, the effects of diet and of exercise were carefully noticed, and were considered the basis of hygiene.' Hippocrates, indeed, appears to have had a clear conception of the relation between the amount of food taken and of the mechanical energy produced by it ; at least, he is extremely care- ful in pointing out that there must be an exact balance between food and exercise, and that disease results from excess either way. The effects on health of different kinds of air, of water, and to some extent of soils, were also considered at a very early date ; though naturally the ignorance of chemistry prevented any great advance in this direction. Hippocrates summed up the existing knowledge of his time on the six articles, which in after-days received the absurd name ' Herodicus, one of the preceptors of Hippocrates, was the first to introduce medi- cinal gymnastics for the improvement of health and the cure of disease ; though gym- nastics in training for war had been used long before. Plutarch says of him, that laboring under a decay which he knew could not be perfectly cured, he was the first who blended the gymnastic art with physic, in such a manner as protected to old age his own life, and the lives of others afflicted with the same disease. He was censured bj Plato for keeping alive persons with crazy constitutions. — Mackenzie on Health. X INTRODUCTION. of the " Non-naturals." ' The six articles, whose regulation was con- sidered indispensably necessary to the life of man, were — air, aliment, exercise and rest, sleep and wakefulness, repletion and evacuation, the passions and affections of the mind. I With the exception of the attempts of the alchemists, and of the chemical physicians, to discover some agent or drug which might in- crease or strengthen the principle of life," the practice of hygiene remained within the same limits until physiology (the knowledge of the laws of life) began to be studied. Hygiene then began to acquire a scientific basis. Still retaining its empirical foundation drawn from observation, it has now commenced to apply the discoveries of physi- ' Tliis title originated in a sentence of Galen, and was introduced into use by the jargon of the Peripatetic school. It was employed in all treatises on hygiene for prob- ably nearly 1,500 years. * It was when chemistry was being rudely studied by the alchemists that an entirely different school of hygiene arose. The discovery of chemical agents, and the great eflFect they produce on the body, led to the notion that they could in some way aid the forces of life, and insure a prolonged, if not an eternal youth, and a life of ages instead of one of years. This belief, the natural result of the discovery of new powers, has not yet entirely died out ; and while there are some who still look to every fresh agent as possibly containing " the balsam of life," there are also still enthusiasts who search the mystic tomes of the alchemists or the Rosicrucians, in the faith that, after all, the great secret was really found. It may be worth while to consider the idea which under- laid the dreams of the alchemists. Life was looked on as an entity or principle liable to constant waste, and to eventual expenditure. If some agent could be found to arrest the waste, to crystallize, as it were, the tissues in their full growth and vigor, decay, it was conceived, would be impossible, and youth would be eternal. In other cases, it was supposed that the agent would itself contain the principle of life, and therefore would at once restore destroyed health, and recall again departed youth. We now know this idea to be wrong in every point. The constant decay the alchemists sought to check is life itself, for life is but incessant change, and what we call decay is only a metamorphosis of energy. To arrest the changes in the body for one single moment would be death, or, short of death, it would be lessening of the energy which is the expression of life. Nor is there any hope that the extension of the period of vital energy can ever be accomplished except by improving the nutrition of the tissues. Here, indeed, it is just possible that, in time to come, drugs will aid Hygiene, either by better preparing food for the purposes of nutrition, or by removing or preventing those chemical changes in the tissues which we call decay. But at present, certainly, no rules can be laid down for the use of drugs in hygiene, except in that debatable land which lies between hygiene and the practice of medicine, that is, in that uncer- tain region which we do not like to call disease, and yet which is not health. ITfTRODUCTIOIir. XI ology to the improvement of health, and to test the value of its own rules by this new light. It is now gradually becoming an art based on the science of physiology, with whose progress its future is identified. But the art of hygiene has at present still another object. If we had a perfect knowledge of the laws of life, and could practically apply this knowledge in a perfect system of hygienic rules, disease would be impossible. But at present disease exists in a thousand forms, and the human race languishes, and at times almost perishes, under the grievous yoke. The study of the causes of disease is strictly a part of physiology,' but it can only be carried out by the practical physician, since an accurate identification of the diseases is the first necessary step in the investigation of causes. The causes being investigated, the art of hygiene then comes in to form rules which may prevent the causes or render the frame more fitted to bear them ; and as in the former case it was the exponent o£ physiology, in this case it becomes the servant of the pathologist. Taking the word hygiene in the largest sense, it signifies rules for perfect culture of mind and body. It is impossible to dissociate the two. The body is affected by every mental and moral action ; the mind is profoundly influenced by bodily conditions. For a perfect system of hygiene we must train the body, the intellect, and the moral faculties in a perfect and balanced order. But is such a system possible ? Is there, or will there ever be, such an art, or is the belief that there will be, one of those dreams which breathe a blind hope into us, a hope born only of our longings, and destined to die of our experi- ence ? And, indeed, when we look around us and consider the con- dition of the world — the abundance of life, its appalling waste ; the wonderful contrivances of the animal kingdom, the apparent indiffer- ence v^ith wdiich they are trampled under foot ; the gift of mind, its awful perversion and alienations ; and when, especially, we note the ' Physiology and pathology are, in fact, one ; normal and abnormal life, regular and irregular growth and decay, must be studied together, just as, in fact, human physi" ology is imperfect without the study of all the other forms of life, animal and vegeta- ble, which are in the world. Separated for convenience, these various studies will finally converge. Xii INTRODUCTION. condition of the human race, and consider what it apparently might be, and what it is; its marvellous endowments and lofty powers; its terrible sufferings and abasement ; its capacity for happiness, and its cup of sorrow ; the boon of glowing health, and the thousand diseases and painful deaths, — he must indeed be gifted with sublime endurance or undying faith wlio can still believe that out of this chaos order can come, or out of this suffering happiness and health. Whether the world is ever to see such a consummation no man can say ; but as ages roll on, hope does in some measure grow. In the midst of all our weaknesses, and all our many errors, we are certainly gaining knowledge, and that knowledge tells us, in no doubtful terms, that the fate of man is in his own hands. It is undoubtedly true that we can, even now, literally choose be- tween health or disease ; not, perhaps, always individually, for the sins of our fathers may be visited upon us, or the customs of our life and the chains of our civilization and social customs may gall us, or even our fellow-men may deny us health, or the knowledge which leads to health. But as a race, man holds his own destiny, and can choose be- tween good and evil ; and as time unrolls the scheme of the world, it is not too much to hope that the choice will be for good. Looking only to the part of hygiene which concerns the physician, a perfect system of rules of health would be best arranged in an orderly series of this kind. The rules would commence with the regulation of the mother's health while bearing her child, so that the growth of the new being should be as perfect as possible. Then, after birth, the rules (different for each sex at certain times) would embrace three epochs;' of growth (including infancy and youth) ; of maturity, when for many years the body remains apparently stationary ; or decay, when, without actual disease, though, doubtless, in consequence of some chemical changes, molecular feebleness and death commence in some part or other, fore- running general decay and death. In these several epochs of his life, the human being would have to be considered — * First expressly noted by Galen. INTEODUCTIOTT. Xlll 1st, In relation to the natnral conditions which, surround him, and which are essential for life, such as the air he breathes ; the water he drinks ; his food, the source of all bodilv and mental acts ; the soil which he moves on, and the sun which warms and lights him, etc. ; in fact, in relation to nature at large. 2d, In his social and corporate relations, as a member of a commu- nity with certain customs, trades, conditions of dwellings, clothing, etc. ; subjected to social and political mfluences, sexual relations, etc. 3d, In his capacity as an independent being, having within himself sources of action, in thoughts, feelings, desires, personal habits, all of which affect health, and which require self -regulation and control. Even now, incomplete as hygiene necessarily is, such a work would, if followed, almost change the face of the world. But would it be fol- lowed ? In some cases the rules of hygiene could not be followed, however much the individual might desire to do so. For example, pure air is a necessity for health ; but an individual may have little control over the air which surrounds him, and which he must draw into his lungs. He may be powerless to prevent other persons fi-om contaminating his air, and thereby striking at the very foundation of his health and hap- piness. Here, as in so many other cases which demand regulation of tlie conduct of the individuals toward each other, the State steps in for the protection of its citizens, and enacts rules which shall be binding upon all. Hence arises what is now termed " State Medicine," a mat- ter of the greatest importance. The fact of " State Medicine " being possible, marks an epoch in which some sanitary rules receive a gen- eral consent, and indicates an advancing civilization. Fear has been expressed lest State Medicine should press too much on the individual, and should too much lessen the freedom of personal action. This, however, is not likely, as long as the State acts cautiously, and only on well-assured scientific grounds, and as long as an unshackled Press discusses with freedom every step.^ ^ A -n-atcliiul care over the liealtli of the people, and a due regulation of matters ■wMcIl concern their liealth, is certainly one of tlie most important functions of Govern- ment. The fact that, in modern times, the subject of hygiene generally, and State Medicine in particular, has commenced to attract so much the public attention, is un- xiv INTRODUCTION^. There are, however, some cases in which the State cannot easily interfere, though the individual may be placed under unfavorable hygienic conditions by the action of others. For example, in many trades, the employed are subjected to danger from the carelessness, or avarice, or ignorance of the employers. Every year the State is, how- ever, very properly more and more interposing and shielding the work- man against the dangers which an ignorant or careless master brings on him. But in other cases the State can hardly interpose with effect ; and the growth of sanitary knowledge, and the pressure of public opinion, alone can work a cure, as, for example, in the case of the dwellings of our poorer classes. In many parts of the country the cottages are doubtedly owing to the application of statistics to public health. It is impossible for any nation, or for any Government, to remain indifferent when, in figures which admit of no denial, the national amount of health and happiness, or disease and suffering, is determined. The early Statistical Reports of the Army by Tulloch, Marshall, and Bal- four, directed attention to the importance of this matter. The establishment of the Registrar-General's office in 1838, and the commencement of the system of accurately recording births and deaths, will hereafter be found to be, as far as the happiness of the people is concerned, one of the most important events of our time. We owe a na- tion's gratitude especially to him to whose sagacity the chief fruits of the inquiry are due, to William Farr. Another action of the Government in our day was scarcely less important. It is impossible to overrate the value of the Government Inquiry into the Health of Towns, and of the country generally, which was commenced forty years ago by Edwin Chad- wick, Southwood Smith, Neil Arnott, Sutherland, Guy, Toynbee, and others, and has, in fact, been continued ever since by the official successors of these pioneers, the former medical officer to the Privy Council, Mr. Simon, the late Dr. Seaton, and the present medical officer of the Local Government Board, Dr. Buchanan. Consequent on this movement came the appointment of medical officers of health to the different towns and parishes. The reports published by many of these gentlemen have greatly advanced the subject, and have done much to diffuse a knowledge of hygiene among th^ people, and at the same time to extend and render precise our knowledge of the conditions of ^ national health. When the effect of all these researches and measures develops itself, it will be seen that even great wars and political earthquakes are really nothing in comparison with these silent social changes. Even now legislation, sucli as the Public Health Act, 1875, and the various measures since passed, is beginning to exert a deep influence. Legislation, and action baaed on legislation, can only proceed slowly, and we must be satisfied if there be a continual advance, though it may not be so rapid as some desire. INTRODUCTIOIT. XV unfit for human beings ; in many of our towns, the cupidity of builders runs np houses of the most miserable structure, for which there is un- ]iappily no lack of applicants ; or masters oblige their men to work in rooms, or to follow plans which are most detrimental to health. But even in such cases it will be always found that self-interest would really indicate that the best course is that we should do for our neighbors as for ourselves. Analyze also the effect of such selfishness and carelessness as has been referred to on the nation at large, and we shall find that the partial gain to the individual is far more than coun- terbalanced by the injury to the State, by the discontent, recklessness, and indifference produced in the persons who suffer, and which may liave a disastrous national result. It is but too commonly forgotten that the whole nation is interested in the proper treatment of every one of its members, and in its own interest has a right to see that the relations between individuals are not such as in any way to injure the well-being of the community at large. In many cases, again, the employer of labor finds that, by proper sanitary care of his men, he reaps at once an advantage in better and more zealous work, in fewer interruptions from ill-health, etc., so that his apparent outlay is more than compensated. This is shown in the strongest light by the army. The State em- ploys a large number of men, whom it places under its own social and sanitary conditions. It removes from them much of the self-control with regard to hygienic rules which other men possess, and is there- fore bound by every principle of honest and fair contract to see that these men are in no way injured by its system. But more than this: it is as much bound by its self-interest. It has been proved over and over again that nothing is so costly in all ways as disease, and that nothing is so remunerative as the outlay which augments health, and in doing so, augments the amount and value of the work done. It was the moral argument as well as the financial one which led Lord Herbert to devote his life to the task of doing justice to the sol- dier, of increasing the amount of his health, and moral and mental training, and, in so doing, of augmenting not only his happiness, but the value of his services to the country. PRACTICAL HYGIENE. ^oaU |. CHAPTER I. WATER. The supply of wholesome water in sufficient quantity is a fundamental sanitary necessity. Without it injury to health inevitably arises, either simply from deficiency of quantity, or more fi-equently from the presence of impurities. In aU sanitary investigations, the question of the water supply is one of the first points of inquhy, and of late years quite unex- pected evidence has been obtained of the frequency with which diseases are introduced by the agency of water. In such an investigation, if the headings of the sub-sections of this chapter ai-e followed, and the facts ai'e. noted under each heading in order, it will be hardly possible to overlook any condition which may have affected health. The order of investigation would be as follows : — Quantity of water per head ; how is it collected ; stored ; distributed ; what is its composition ; is it wholesome water at its source and throughout, or has it been contaminated at any point of its dis- tribution ; what are the effects presumed to arise from it ? ' ^ Anni/ Regulations on t7ie Subject of Water.— The Regulations for the Medical De- partment of Her Majesty's Army frequently refer to the supply of water. In Part I., Section iii., paragraph 81 (o, the Surgeon-General and Deputy Surgeons-General are directed to '' ascertain that the water-supply is good and abuudant. and perfectly protected from pollution." Also paragraph' 21 (b), '• that the means of ablution and cleanliness are sufficient, and made use of by the men." As regards hospitals they are also to ascertain (paragraph 25). " that the water-supply is pure, pnd abundant and sufiicieuc for all the requirements of a hospital, . . . and that the lava- tories, bath-rooms, and water-closets are kept in proper order." In the Sanitary Reg- ulatioas, Part V., Section ii. , paragraph 618, the medical officer in charare of troops is ordered to examine, from time to time, •' the quality and amount of -drinking-water," and to ascertain that there is "no soakage from latrines, cesspools, drains, or other sources of impurity." He is also ordered to inspect the lavatories and baths. In Sections vi. and vii. the same supervision over the water-supply of camps and garri- sons and transport ships is enjoined. When an army takes the field a Sanitary Officer is appointed, and he examines into all sanitary points, including the wcter-supply. (Section viii., paragraph (179.) In the quarterly and annual reports the water-supply has to be considered, in 3 PRACTICAL HYGIENE. SECTION L ON THE QUANTITY AND SUPPLY OF WATER. Sub-Section I. — 1, Quaittity of Water for Healthy INIen. In estimating the quantity of water required daily for each person, it is necessary' to allow a liberal supply. There should be economy and avoid- ance of waste ; but still, any error in supply had far better be on the side of excess. In England many poor families, either fi'om the difficulty of obtaining water, or of getting lid of it, or fi-om the habits of uucleaiiliness thus handed down from father to son, use an extremely small amount. It would be quite incon-ect to take this amount as the standard for the com- munity at large, or even to fix the smallest quantity which will just suffice for moderate cleanliness. It is almost impossible to give a definition of cleanliness, nor perhaps is it necessary, since there is a general understand- ing of what is meant. It must be clearly understood for what pui-jDOses water is supj^lied. It may be required for di'inking, cooking, and ablution of persons, clothes, utensils, and houses ; for cleansing of closets, sewers, and streets ; for the di-inking and washing of animals, washing of cai'riages and stables ; for trade purjioses ; for extinguishing fires ; for public fountains or baths, etc. In towns supphed by water companies, the usual mode of reckoning is to diA^ide the total daily supply in gallons by the total pojDulation, and to express the amount per head per diem. The following are some of the gross amounts used at the present time for all the above purposes, as judged of in this way : — Gallons per head of popu- lation daily. New River Company in London, 1879 ' 28.7 East London Water- Work Company, 1879 342 Kent Chelsea " West Middlesex " Grand Junction ' " South wark and Vauxhall Lambeth 29.1 36.5 26.5 32.9 40.9 3L5 Average of London Districts 32.7 common with other sanitary conditions, including' " the sources, quality, and quan- tity of the water-supply, and whether it is wholesome, and what means of purifica- tion are in use, if such be necessary. Also, " Baths and lavatories, their couditions, and if sufficient for cleanliness for troops and sick ; whether there are bathing pa- rades, and how often a week." (Appendix No. 15.) In the Instructions in Case of an Invasion of Cholera (Appendix No. 14. paragraph 7), special attention is directed to the water-supply. Provision is also made for the chemical examination of water when required, PartV., Section vi. . paragraph 607. ' These and other London amounts are taken from the Report of the Select Com- mittee of the House of Commons on London Water-Supply, 1880. p. 308. With the exception of the three first on the list the London supply is from the Thames. The Edinburgh amount is taken from the same work. WATER. 3 Gallons per head of popu- lation daily. Southampton Water- Work Company, 1879 35 Glasgow Water- Work Company, 1879 50 Edinburgh 35 Liverpool 30 ' Sheffield 20 Paris 31 Calcutta (for Europeans),'' amount originally intended . 30? " (for Natives), amount originally intended .... 15 ? New York' 83 In 1857 the average supply to fourteen EngHsh towns, of second-rate magnitude, was 24 gallons. The average of 72 English and Scotch towns, supplied on the constant system, is 131.4 gallons per house (but this in- cludes the sujDply to factories, of which there were 16,087 to 889,028 houses), or (at 5 persons to each house), 26.7 per head; of 23 towns, sup- pHed on the intermittent system, 127 per house, 25.4 head, including 1,367 factories to 137,414 houses ; and of London, also on the intermittent sys- tem, 204, or 41 per head, including 5,340 factories to 499,582 houses." The range in indi^ddual cases is, however, very great, from 25 gallons per house (5 per head) in one small town to 700 at IVliddlesborough ( 140 per head). ]\Ir. Bateman states that in the manufacturing towns of Lancashke and Yorkshire, the present amount is from 16 to 21 gallons ; in some cases less. ° At Norwich about 14| gallons daily per head are supplied on the con- stant system, of which 10. 5 are taken for domestic purposes, 3 for trade, and .7 gallons for public and sanitary pm-poses." In Manchester the sup- ply is also constant, and is 14 gallons per head for domestic, and 7 for trade purposes. In 1878 in fifteen American cities the supply was on the average 55 gallons per head. ' By decision of the Secretary of State for War, a soldier receives 15 gal- lons daily ; no extra allowance is made for the wives and children in a regiment. The gross amount thus taken is used for different pui-poses, which must be now considered. Amount for Domestic Purposes, excluding Water- Closets. This item includes drinking, cooking, washing the person, the clothes, the house utensils, and the house. ' See pag-e 15. ^ The daily supply in Calcutta was, in 1871, 5,000,000 gallons of filtered water; in 1879 it was 7^ millions and 1,000.000 gallons unfiltered for watering roads. This, however, after all deductions, only left o gallons per head for domestic purposes. A new scheme is in progress, which will provide 8,000,OUO more daily, thus securing 12 gallons per head. ^ In former editions this was stated at 300, but it is given as 100 (?) in Buck's Hy- giene and Public Health. These are, however, U. S. gallons, equal to 83 imperial gallons. ^ Sixth Report of the Rivers Pollution Commissioners, pp. 232, 233. ^ See table in the Sixth Report of the Rivers Pollution Commissioners * Report by Dr. Pole, F.R.S. Enormous saving was accomplished by taking steps to prevent waste. ' Dr. P. H. Brown, in Buck's Hygiene, vol. i., p. 180. A table is also given by Prof. W. R. Nichols (p. 212) showing the supply to eighteen cities, ranging from 20 imperial gallons in Louisville to 116 in Washington. 4 PRACTICAL HYGIENE. An adult reqmres daily about 70 to 100 ounces (S^ to 5 pints) of water for nutrition ; but about 20 to 30 ounces of this are contained in the bread, meat, etc., of his food, and the remainder is taken in some form of liquid. There are, however, wide ranges from the average. Women drink rather less than men ; children drink, of com'se, absolutely less, but more in pro- portion to their biilk than adults. The i-ules for transport vessels aUow 8 pints in, and 6 out of the tropics for cooking and drinking. During hot weather and great exertion a man will, of course, drink much more. In some experiments made for the "War OfMce in 1866, at the Kichmond Barracks in Dublin and the Anglesea Barracks in Portsmouth, the amount of the different items of the domestic suj^jDly (excluding latrines, which take 5 gallons per head) is thus given : — Gallons per soldier daily. Cook-house 1 Ablution rooms and baths 4 Cleaning barracks 2.25 Wash-house and married people 2.5 9.75 Dr. Parkes measured the water expended in several cases ; the followmg was the amount iised by a man in the middle class, who may be taken as a fair type of a cleanly man belonging to a faiidy clean household : — Gallons daily per one person. Cooking 75 Fluids as cliink (water, tea, coffee) 33 Ablution, including a daily sponge-bath, which took 2-^ to 3 gaUs. 5 Share of utensil and house-washing 3 Share of clothes (laundi-y) washing estimated 3 12 These results are tolerably accordant with the Dublin experiments, if we remember that with a large household there is economy of water in wash- ing utensils and clothes, and that the number of wives and chilch-en in a regiment is not gi-eat. In poor families, who draw water from wells, the amount has been found to varj' from 2 to 4 gallons j)er head, but then thei'e was certainly not perfect cleanhness. Mr. Bateman ' states that in a group of cottages with 82 inmates, the daily average amount was 7^ gallons per head, and in another group 5 gallons per head. Dr. Letheby found in the poor houses in the city of London the amount to be 5 gallons.'' In experiments in model lodging- houses, Mr. Muir states that 7 gallons daily were used." Mr. Easton, in his own house in London, found he used about 12 gallons per head, of which about 5 were for closets, leaving 7 for other uses ; but probably the laundry washing was not included. In the conrict prison at Ports- mouth, where there are water-closets, and each j^risoner has a general bath once a week, the amount is 11 gallons (Wilson). ' On Constant Water Supply, by Messrs Bateman. Beggs, and Rendle. 1867. '^ Report of the East London Water Bill Committee, 1867. Questions 234(5 and 2347. ^ Ibid., p. 5. WATEE. In several of tlie instances just referred to, it may be questioned, whether the amount of clea nlin ess was equal to what would be expected in the hio'her ranks. In most instances c[uoted no general baths were used ; but it is now becoming so common in England to have bath-rooms, that it is said they are often jDut even in eight-roomed houses. A general bath for an adult requii-es, with the smallest adult bath {i.e., only 4 feet long and 1 foot 9 inches wide), 38 gallons, and many baths will contain 50 to 60 gal- lons. A good shower-bath will dehver 3 to 6 gallons. General baths used only once a week will add 5 or 6 gallons -per head to the daily consump- tion. We may safely estimate that for personal and domestic use, "without baths, 12 gallons per head daily should be given as a usual minimum sup- ply ; and with baths and perfect cleanliness, 16 gallons should be allowed. This makes no allowance for water-closets or for unavoidable waste. If from want of supply the amount of water must be hmited, 4 gallons daily per head for adults is jDrobably the least amount which ought to be used, and in this case there could not be daily washing of the whole body, and there must be insufficient change of underclothing. If jDubhc baths are used the amount must be greatly increased. The largest baths the world has seen, those of Ancient Eome, demanded a sup- ply of water so gTeat as, according to Leshe's calculations, to raise the daily average per head to at least 300 gallons. Amount for Water- Closets. The common aiTangements with cisterns allow any quantity of water to be poui-ed down, and many engineers consider that the chief waste of water is owing to water-closets. In some distiicts, by attention to this point, the consumption has been gTeatly reduced ; in one case fi'om 30 to 18, and in another from 20 to 12 gallons per head. It has not yet been precisely determined what quantity should be allowed for water-closets. Small cisterns, tenned water-waste preventers, are usually put up in towns with constant water-sujDply, which give only a certain hmited amount each time the closet is used. The usual size now in use holds about two gal- lons ; but even two gallons ai-e often insufficient to keep the pan and soil-pij)e perfectly clean. This depends a good deal upon the kind of closet used. The water-waste j)reventer must be sometimes allowed to fill again, and be again emptied. Considering also that some persons "^-ill use the closet twice daily and sometimes oftener, and that occasionally more water must be used for thoroughly flushing the pan and soil-pipe, six gallons a day per head should probably be allowed for closets. In this i^articular instance a false economy in the use of water is most undesii'able. Water latrines re- quire less ; the amount is not precisely known ; the experiments of the Eoyal Engineers at Dubhn give an average of five gallons per head, but it is considered this might be reduced. In fixing the above Cjuantities, viz., 12 gallons per head for all domestic purposes except general baths and closets, 4 gallons additional for general baths, and 6 for water-closets, endeavors have been made to base them upon facts, and they are probably not much in en-or. It is, however, necessary to make some allowance for unavoidable waste within the premises, and for exti-a supply to closets, and it ^t11 be a moderate estimate to allow 3 gallons daily per head for this pui-pose. This will make 25 gallons. There is another reason for beheving that an amormt of about 25 gallons per head should pass fi'om eveiy house daily into sewers, if sewers ai-e used. 6 PRACTICAL HYGIENE. It is that in most cases this quantity seems necessary to keep the sewers perfectly clear, though in some cases, no doubt, with a well-aiTanged and constnicted sewei-age, a less amount may suiiice. But the complete clear- age of sewers is a matter of such fundamental importance that it is neces- sary to take the safest course. Hitherto much w^ater has run merely to waste. Amount for Animals. From expeiiments conducted in some cavahy stables in 1866, by the Eoyal Engineers, the ^Yar Office authorities have fixed the daily supply for cavahy horses at 8 gallons, and for artillery horses at 10 gallons per horse. This is to include washing hoi-ses and caii-iages. The amount seems i-ather small Of course the amount that hoi"ses diiiik vaiies as much as in the case of men, and depends on food, weather, and exertion ; but if a horse is allowed free access to water at all times, and thLs should be the case, he will diTnk on an average 6 to 10 gallons, and at times more. In the month of October, with cool weather, a hoi-se 16 hands high, doing 8 miles a day car- riage work, and fed on com and hay, was foimd to di'ink 1^ gallons. An- other caniage horse drank nearly the same amount. In a stable of cavahy horses, doing veiy Httle work, and at a cool time of the year, the amount per horse was found to be Q-^^ gallons. The amount used for washing was 3 gallons daily. Li hot and du'ty weather the quantity for both piu-jDoses would be lai"gei\ For washing a horse requii'es at least 1-^ gaUon, and twice this amount if he is washed twice a day. There is a saving, however, if gi'ooms wash several horses in the same water. It is difficult to say how much is used for caniage washing. On the whole, including carriage washing, etc., 16 gallons per horse is not an excessive amount. A cow or an ox, on dry food, will drink 6 or 8 gallons ; a sheep or pig, ^^ to 1 gallon. In the Abys- sinian expedition, the following was the calculation for the daily expendi- tm-e of water per head on shipboaixl : — Gallons. Elephants 25 Camels 10 Oxen (large draught) 6 Oxen (small pack animals) 5 Horses 6 Mules and ponies 5 For 20 elephants and 100 men, 50,000 gallons were put on board for a voyage of 60 days.' Amounts required for Municipal and Trade Purposes. For municipal purposes water is taken for washing and watering streets, for fountains, for extinguishing fii*es, etc. The amount for these and for trade pui-j^oses will vaiy gi-eatly. Professor Rankine,^ who gives an aver- age allowance of 10 gallons per head for domestic pm-jDOses, proposes 10 more for trade and town use in non-manufacturing towns, and another 10 gallons in manufacturing to^vns. Considering, however, the comparatively small number of horses and cows in towns as compared Avith the human ' This information was derived from Major Holland, Assistant Quartermaster-Gen- eral, Abyssinian Army. » Civil Engineering, 1863, p. 731. WATER, 7 population, and tlie frequent rains in this country which, lessen watering of sti'eets, the two latter quantities might, perhaps, in most cases be halved. If, now, the total daily amount for all purposes be stated per head of jDopulation, it will be as follows : — Gallons. Domestic supply (without baths or closets) 12 Add for general baths 4 Water-closets 6 Unavoidable waste , , 3' Total house supply 25 Town and trade purposes, animals in non-manufac- ) ^j taring town | Add for exceptional manuf acturiag towns 5 In India and hot countries generally, the amounts now laid down would have to be altered. Much more must be allowed for bathing and for wash- ing generally, while a fresh demand would arise for water to cool mats, punkahs, or air-passages by evaporation. In Calcutta it was intended to supply to Europeans 30 gallons per head, and to natives 15 gallons daily, ^ but the amount has been reaUy much less up to the present time. In Madras it was assumed that the ultimate amount used would be 20 gallons per head, including all residents.* At present (in 1879) the total sapply is about 2^ millions daily ; this in a population of about 400,000 would give 6^ gallons per head. As yet, however, all the population do not use it. 2. Amount Required for Sick Men. In hospitals a much larger quantity must be provided, as there is so much more washing and bathing. From 40 to 50 gallons per head are often used. There are no good experiments as to the items of the consumption, but the following is probably near the truth : — Gallons daily. For drinking and cooking, washing kitchen and utensils . . 2 to 4 For personal Avashing and general baths 18 to 20 For laundry washing 5 to 6 Washing hospital, utensils, etc 3 to 6 Water-closets 10 38 to 46 It would be very desirable to have more precise data ; j^ossibly the amount for closets is put too high, but not greatly so when all cases are taken into account. ' Most engineers reckon the waste much hijjher than this ; there is no doubt much room for economy in this naatter. The greatest waste appears to be in transit before reaching the houses. ■^ This allowance will vary in every case, and must be verv uncertain. In the Lou- don district 18 per cent, is reckoned for trade purposes. ^ Gordon's Army Hygiene, p. 4?0. * Captain TuUoch's Keport on the Drainage of Madras, 1865, p. 9S. PRACTICAL HYGIENE. Sub-Section II. — Collection, Storage, and Distribution of Water. The daily necessary quantity of water per head being determined, the next points are to collect, store, and distribute it. 1. Collection. In many cases collections of water occur naturally in the depressions of the surface, or the commingling of small streams forms rivers. The col- lection by men consists almost entirely in imitating these natural pro- cesses, and in directing to, antl finally arresting at some point, the rain or the streamlets formed by the rain. The arrangements necessarily differ in each case. Eain-water is collected from roofs, or occasionally from pave- ments and flags, or cemented grovmd ; in hilly countries, with deep ra^dnes, a resen'oir is sometimes formed by canning a wall across a valley, which is well placed for receiving the tributary waters of the adjacent hills, or on a flatter surface trenches may be arranged, leading finally to an excavated tank. The collection of the surface water which has not penetrated is usually aimed at, but it has been proposed by Mr. Bailey-Denton ' to collect the sub-soil water by drainage-jjipes, and thus to accomplish two objects^ — to dry the land, and to use the water taken out of it. Eelow the surface the water is collected by wells, shallow, deep, and Artesian, or by boring. "With resjDcct to wells, if they are situated near a river, and do not pro- duce sufficient water, it has been recommended to lay perforated earthen- ware pipes parallel to the river, and below its fine-weather level, in trenches not less than six feet deep, and filled up above the pipes with fine gravel. The jjipes end in the well, and water jjassing from the river and filtered through the gravel passes into them. The American tube-well (Norton's patent) is a very useful invention. It is merely a ^mall iron pipe driven into the ground in lengths by means of a "monkey"; the water passes through small holes in the lowest part of the pijDe, and is drawn up by a common or double-action pump according to the depth.' All these matters fall within tl\e j^rovince of the engineer, and the med- ical part of the question is chiefly restricted to the consideration of the purity of the water. The cleanliness and natiu'e of the surface (lead, zinc, coi^per, etc.) on which rain falls ; the kind of gTOund ; and of cultivation ; the amount of manuring ; the nature of the subsoil if drainage water is used, and points of the like kind, have to be considered and sujjplemented by a chemical examination. Plain. — The amount of water given by rain can be easily calculated, if two points are known, viz., the amount of rainfall, and the area of the receiving sm-face. The rainfall can only be determined by a rain-gauge (the mode of constructing which is given in the chapter oil Peacticai, Meteorology) ; the area of the recei\dng surface must be measured. Supposing that it be known that the rainfall amounts to twenty-four, inches per annum, and the area of the recei^dng surface (say the roof of a house) is five hundred sc[uare feet : ' On the Supply of Water to Yillajres and Farms, by Mr. Bailey-Denton. C.E. ^ In the Ashantee Expedition tlie lube-well did not succeed, as it got clogged with sand. See Sir A. D. Home's Report, Army Medical Reports, vol. xv., p. 247. WATER. - 9 MultijDly the area by 144 (number of squai-e inches in one square foot), to bring it into square inches, and multiply this by the rainiaU. The pro- duct gives the number of cubic inches of rain "svhich fall on the "house-top in a year, or in any time the rainfall of which is known. This number, if divided by 277.274, or multiphed by .003607, -will give the number of gallons which the roof of the house will receive in a year (viz., in this case 6.232 gaUons) ; or, if it is wished to express it in cubic feet, the number of cubic inches must be divided bv 1728 (number of cubic inches in a cubic footj, or multiphed by .00058. To calculate the receiving stu-face of the roof of a house, we must not take into account the slope of the roof, but merely ascertain the area of the flat space actually covered by the roof. The joint ai^eas of the gTound-floor rooms will be something less than the area of the roof, which also covers the thickness of the walLs and the eaves. In most English towns the amount of roof space for each pei'son cannot je estimated higher than 60 sc[uai-e feet, and in some poor districts is much less. Taking the rainfall in all England at 80 inches, and assuming that all is saved, and that there is no loss fi'om evaporation, the receiving sui-face for each person would give 935 gallons, or 2^ gallons a day. But as few town houses have any reservoirs, this quantity xnins in great part to waste in ui-ban districts. In the countiy it is an important soui'ce of sup- ply, being stored in cisterns or water-butts. If, instead of the roof of a house, the receiving surface be a piece of land, the amount may be calcu- lated in the same way. It must be understood, however, that this is the total amount reaching the gTound ; all of this viill not be available ; some will sink into the gi'ound, and some will evaporate ; the C[uantity lost in this way will vaiy with the soil and the season fi'om the one-half to seven- eighths. To facilitate these calculations, tables have been constructed by engineers. ^ One inch of rain dehvers 4.673 gallons on eveiy squaj-e yard, or 22,617 gallons (101 tons by weight) on each square acre.' In estimating the annual yield of water from rainfall, and the ^ield at any one time, we ought to know the gTeatest annual rainfaU., the least, the average, the period of the year when it falls, and the length of the rainless season. It must also be remembered that the amount of rainfall differs very greatly even in j^laces near together. Springs, Fdvers. — ^It win often be a matter of gi-eat importance to de- termine the yield of springs and small livers, as a body of men may have to be placed for some time in a paiiiculai- spot, and no engineeiing opinion, perhaps, can be obtained. A spring is measured most easily by receiving the water into a vessel of kno'^Ti capacity, and timing the rate of filhng. The spring should be opened up if necessaiy, and the vessel stould be of large size. The vessel may be measured either by filhng it first by means of a known (pint or gaUon) measure, or by gauging it. If it be round or squai'e, its capacity can be at once known by measming it, and using the rules laid down in the chapter for measuring the cubic amount of air in rooms. The ca- pacity of the vessel in cubic feet may be brought into gallons if desirable, by multiplying by 6.23. If a tub or cask only be procurable, and if there is no pint or gallon measure at hand, the following rule may be useful : — ' Beardmore's Mannal of Hydrology, p- 61 ; see also table in Appendix E, Vol. II. ^ To bring cubic inches into gallons, multiply by -iO and divide by 11,091, or mul- tiply at once by .0036u7. 10 PRACTICAL HYGIENE. Take the bung diameter in inches, by measuring the circumference ai the bung, di\T.ding by 3.1416, and making an allowance for the thickness of the staves ; square the bung diameter, and multiply by 39. Take the head diameter in inches by du-ect measurement, and square it, and multi- jjly by 25. Multiply one diameter by the other, and the product by 26. Add the sums, and multiply by the length of the cask in inches ; then mvdtiply by .000031473, and the result is given in gallons.' "When it is required to ascertain the yield of any small watercoui-se with some nicety, it is the practice of engineers to dam up the whole stream, and convey the water by some artificial channel of known dimen- sions. 1. A wooden trough of a certain length, in which the depth of water and the time which a float takes to pass from one end to the other is measxu-ed. 2. A sluice of known size, in which the difference of level of the water above and below the sluice is measui-ed.'^ 8. A weu- formed by a plank set on edge, in which a rectangular notch is cvit, usually one foot in width ; over this the water flows in a thin sheet, and the difference of level is measured by the depth of the water as it flows over the notch. Then by means of a table the amovmt of water dehvered per minute is read off. The weii- must be formed of very thin board and be perfectly level ; a plumb-hne has generally to be used.' This jDlan of measuring the jdeld of water-cotu-ses is the one now most generally adopted by engineers. The same object may, however, be attained with sufl&cient accuracy for the pui-jDOses of the medical officer by selecting a portion of the stream where the channel is pretty uniform, for the length of, say not less than twelve or fifteen yards, and in the coui'se of which there are no eddies. Take the breadth and the average depth in thi-ee or four places, to obtain the sectional area. Then, dropping in a chij^ of wood, or other hght oli- ject, notice how long it takes to float a certain distance over the portion of channel chosen. From this can be got the svu-face velocity per second, which is greater of course than the bottom or the mean velocity. Take ' Nesbit's Practical Mensuration, 1859, p. 309. Another rule, applicable to com- mon forms of casks, is to multiply the culie of the diagonal by 0.U(j3o ; the cube of the diagonal is got by adding the square of half the sum of the diameters in inches to the square of half the length ; then this sum multiplied by its square root gives the cube of the diagonal. This and many other useful calculations can be very conven- iently done by means of the common, or carpenter's slide-rule. ■■^ Diacharge of water through a sluice. — Multijily breadth of opening by the height; this gives the area of the sluice. Disdiarge — area, multiplied by five times the sqvnre root of head of water in feet. — The head of water is the difference of level of the water above and below the dam, if the sluice be entirely under the lower level; or the height of the upper level above the centre of the opening, if the sluice be aVo.e the lower level. ^ Discharge of water over a weir one foot i)b length. — If the weir is more or less than a foot, multiply the quantity in the table opposite the given depth by the length of the weir in feet, or decimals of a foot. Depth falling over, inches. Discharge per minute. Depth falling over, inches. Discharge per minute. 1 H 2 ; 1.70 cubic feet. 4.83 " " 8.84 " " 13.63 " " 2i . 3 3* . 4 19.70 cubic feet 2.162 " " 33.23 " " 40.71 " «' Thus, if the weir measure 1 foot, and the depth of water falling over be 3 inches, the delivery is read at once, viz., 13.63 cubic feet, or 84.9 gallons per minute. TTATER, 11 foui'-fiitlis of the surfaee-velocitr (being nearly the proportion of mean to smiace Telocity), and multiply by the sectional area. The resiolt vrill be the yield of the stream per second. it may sometimes be worth "svhile, if labor be at hand, to remove some of the uregularities of the channel, or even to dig a new one across the neck of a bend in the coui'se of the sti'eam. The yield of a spiing or small river should be determined several times, and at difterent periods of the day. Wells. — The jield of wells can only be known by pumping out the water to a certain level and noticing the length of time requii'ed for refill- ing. In cases of cojiious flow of water, a steam-engine is necessary to make any impression ; but, -in other cases, pumjoing by hand or horse labor may be sufficient j^erceptibly to depress the water, and then, if the c[uantity taken out be measvu'ed, and the time taken for reiilhng the well be noted, an apx^roximate estimate can be formed of the yield. Permanence of Supply. — ^It is obvious that the permanence of the sup- ply of a spring or small stream may often be of the gTeatest moment in the case of an encampment, or in the estabhshment of a permanent si:ation. In the fii'st place, evidence should, when available, be obtained. If no evidence can be got, and if the amount and period of rain be not known, it is almost impossible to amve at any safe conclusion. The country which foiTQis the gatheiing gi'ound for the springs or rivers should be con- sidered. If there be an extensive backgTOimd of hills, the springs toward the foot of the hills "s\ill probably be pennanent. In a flat countiy the permanency is doubtful, unless there be some evidence from the tempera- tui'e of the spring that the water comes fi-om some depth. In limestone regions spiings ai-e often fed from subten-anean reservou's, caused by the gTadual solution of the rocks by the water charged with cai'bonic acid ; and such springs are very permanent. In the chalk districts there ai-e few springs or streams, on account of the porosity of the soil, unless at the point the level be considerably below that of the country generally. The same may be said of the sandstone formations, both old and new ; but deep weUs in the sandstone often yield largely, as the peiTaeable rocks form a vast resers-oii-. In the granitic and trap districts, small sti*eams ai'e liable to great variations, unless fed from lakes ; spiings are more pennanent when they exist, being j^erhaps fed from large collections or lochs. 2. Storage. The amount of storage requii-ed will depend on circumstances, viz., the amount used, and the ease of replenishing. It is, of coui'se, easy to calcu- late the space recjuired when these conditions are knn-um, in this way : — The number of gallons required daily for the whole population must be divided by 6.23 to bring into cubic feet, and multiphed by the number of days which the storage must last ; the product is the necessary size of the reservoir in cubic feet. Many waters, particularly rain water, must be filtered thi'ough sand b }f ore they pass into small cisterns, and the filter should be cleaned eveiy three or four months. Fig. 1 is a single filter recommended by the Bar- rack Commission. ' A double filter can be made by haring a second chamber. Whatever be the size of the reservon, it should be kept carefully clean, ■ Report on the Mediterranean Stations, 1883. 12 PRACTICAL HYGIENE. and no possible source of contamination should be permitted. In the large reservoirs for town supply, the Avater is sometimes rendered impure by lloods washing surface refuse into them, or by substances being thrown in. In fact, in some cases, water pure at its soui'ce becomes imi^ure in the reservou's. Some large cities are still supplied principally by rain-water, as Con- stantinople, — where under the houses are enormous cisterns, — Venice, and other places. Gibraltar and Malta are in part suj^plied in this way. As far as possible, all reservoirs, tanks, etc., should be covered in and ventilated ; in form they should be deep rather than extended, so as to lessen evaporation, and secure coolness. Though they should be periodi- cally and carefully cleaned, it would appear ihat it is not always wise to disturb water-plants which may be growing in them ; some plants, as the Protococcus, the Chara, and others, give out a very large amount of oxygen, and thus oltidize and render innocuous the organic matter which may be dissolved in the water or volatilized from the surface. ' Dr. Chevers men- jnomalhcoveT^if stone PavvntJ Level of Ground ^ Pia. 1. tions that the water of some tanks which were ordered to be cleared of water-plants by Sir Charles Napier, deteriorated in quality. Other plants, however, as some species of duckweed (Levma at home, Pistia in the tropics), are said to contam an acrid matter which they give off to the water. It would be well to remove some of the plant, place it in pure water in a glass vessel, and try by exi^eriment whether the amount of organic matter in the water is increased, or whether any taste is given to the water. The presence of some of the Nostoc family gives rise to an offensive pig-pen odor when decaying.' Dead vegetable matter should never find its way into, or at any rate remain in, the reservoir. Whenever a reservoir is so large that it cannot be covered in, a second smaller covered tank, capable of holding a few days' supply, might be pro- vided, and this might be fitted with a filtei', through which the water of the large reservoir might be led as required. ' Clemens, in Archiv. fiir Physiol. Heilk.. 1853. ^ Farlow. Supplement to First Annual Report of State Board of Health, etc., of Massachusetts, 1877, p. 143. WATER. 13 When tanks are large they are made of earth, stones, or masonry ; if mortar be used, it should, as in the case of the smaller reservoirs, be hy- drauhc, so that it may not be acted on by the water. The materials of small reservoirs and cisterns are stone, cement, brick, slate, tiles, lead, zinc, and iron. Glass-lined wooden cisterns have also been proposed. Of these slate is the best, but it is rather liable to leakage, and must be set in good cement or in Spence's metal ; common mortar must not be used for stone or cement, as hme is taken up and the water becomes hard.^ Leaden cisterns, as in the case of leaden pipes, often yield lead to water, and should be used as little as possible, or should be protected. Lead cisterns are corroded by mud or mortar, even when no lead is dis- solved in the water. Iron cisterns and pijDes are often rapidly eaten away ; they are now sometimes protected by being covered inside with Portland cement or with a vitreous glaze. Crease's patent cement is a very useful covering. Birff' s process of producing the magnetic oxide on the surface of iron is coming into use. Glalvanized iron tanks are also very much used. They must be covered, and in India be protected from the sun. Zinc has been recommended, but water passing through zinc pipes, or kept in zinc pails, or in so-called galvanized iron vessels, may produce symptoms of metallic poisoning,'^ and even taste strongly of zinc salts, especially if the water is rich in nitrates. It would certainly be best to abandon lead, zinc, and galvanized iron as materials for cisterns, as much as possible ; iron coated by the Barff process is much to be preferred. Cisterns should always be well covered, protected as much as possible from both heat and hght, and thoroughly ventilated, if they are of any size. Care should always be taken that there is no chance of leakage of pipes into them. A common source of contamination is an overflow pipe passing direct into a sewer, so that the sewer gases pass up, and being confined by the cover of the cistern, are absorbed by the water ; to prevent this, the overflow pipe is curved so as to retain a -little water and form a trap, but the water often evaporates, or the gases force their way through it ; no over- flow pipe should therefore open into a sewer, but should end above ground over a trapped grating.^ A cistern supplying a water-closet should not be used to supply cooking and drinking water, as the pipes leading to the closet often conduct closet air to the cistern. Hence, a small cistern (water- waste preventer) should be used for each closet. Cisterns should be periodically and carefully inspected ; and in every new building, if they are placed at the top of the house, convenient means of access should be provided. Tanks to hold rain-water require constant inspection. WeUs (which are really reservoirs) are very hable to contamination from surface washings during rains. A good coping will often prevent this ; but if there is much subsoil soaking, lining with iron to a certain depth, or covering with brickwork set in cement for a sufficient depth to arrest the flow, is desirable. ' In two cases in Ireland (at Belturbet and Monaghan) so much lime was taken up from the lining- of the tanks that the water was strongly alkaline and tasted caustic. See Eeport on Hygiene, Army Medical Reports, vol. six., p. 170. — [F. de C] ^ Dr. Orsborn, formerly of Bitterne, has seen several cases of this kind. See also Downes, Sanitary Record, vol. ix., p. 333. ^ For an instance of typhoid fever produced by this cause, see Lectures on State Medicine, by F. de Chaumont, pp. 76, 77. See also Dr. Blaxall's Report on Enteric Fever at Ilkeston in 1880. 14 PRACTICAL HYGIENE. 3. Distribution. When houses are removed from sources of water the supply should be by aqueducts and pipes. The distribution by hand is rude and objection- able, for it is impossible to supply the proper quantity, and the risks of contamination are increased. Some of the most extraordinary^ of the Ro- man Avorks in both the Eastern and Western Empires were undertaken for the supply of water — works whose ruins excite the astonishment and should rouse the emulation of modern nations. The plans for the distribution of water should include arrangements for the easy and immediate removal of dirty water. This is an essential point, for in many towns where 1 ouses are not properly arranged for small families, there are no means of getting rid of water from the upper rooms, and this inconvenience actually limits the use of water, even when its supply is ample. The supply of water to houses may be on one of two systems, intermit- tent or constant. The difference between the two plans is, that in the first case there is storage in the houses for from one to three days ; while in the latter case there is either no storage, or it is only on a very small scale for two pui^DOses, viz., for water-closets and for the sujiply of kitchen boilers.' It should, however, l^e understood that the constant supply has not always meant in jiractice an unlimited supply, nor has it been the case that the water in the house pipes was always in direct communication with the water in the reservoirs. On the contrary, the water to the houses has often been cut off, jjarticidarly in places where the supply was limited, and the fittings not good, and where there was great waste. The great arguments against storage on the premises (except on a limited scale for closets and boilers) are the chances of contamination in cisterns, and the very imperfect means of storage. In poor houses wooden casks or barrels ai*e often used, and may be placed in the worst situations. Although the arguments against the storage system are directed in part against removable failures, it must, howevei", be admitted that, especiallj' in poor houses, the inspection and cleansing even of a well-placed cistern will never be properly done, and that with all precautious the chances of contamination of the water dvu-ing storage ai-e very great. As regards this point, the constant system has a very great superiority, for there is no chance for contamination except in the resei'\'oir or in the pipes. So gi-eat an advantage is this in a sanitary point of view, that almost all those who have paid most attention to sanitary affairs have advocated the constant system. It is, however, quite necessary that it should be understood what the constant system sometimes has been in practice. When there is an abundance of water, as at Glasgow, the stoppages of water may have been few, but when water has had to be economized, the water has been from time to time shut off from the house pipes, and then no water has been procurable for hours. This, however, is avoided as much as possible in the day time, so that the inconvenience is reduced to a minimum. In some cases, again, in order to economize water, a throttle or ferrule has been in- ' Much valuable evidence on the constant supply may be found in the Report of the Hovise of Commons Committee on the East London Water Bills, 1 8f)7. It is curious to see how difficult the definition of a con.«;tant supply was found to be. The differ- ence of opinion between engineers on the desirability of a con.stant supply is shown to be considerable. The statements in the text are drawn from a collation of this evi- dence, and from a consideration of Mr. Bateman's pamphlet, and many other works. "WATER. 1 5 troduced into the communication or house pipe,' lessening the diameter to |th or even to Jgth of an inch, or smaller, so that if the head of pressure be small the water flows very slowly, and sometimes merely dribbles. In other cases, a meter is put on a pipe communicating with several houses ; and the owner of the houses is charged for the watei-, and this leads him to enforce a very sparing use of it. In all these ways the constant system may tell against the consumer, while, on the other hand, great waste, leak- ing fittings, and fraudulent abstraction of water (to avoid which there are several ingenious contrivances) tell against the company, and lead to a de- preciation of their proj)erty. In spite of all these difficulties the system of constant supply, in some shape or other, has bcsen carried out in about 150 towns in England ;'' and the Metropolis Water Act of 1871 ordered constant sujDply for London, if demanded by the ratepayers, and if proper fittings are provided. In providing a constant supply, certain precautions are necessary. The fittings must be as perfect as possible. In some cases, when the system has been changed from the intermittent to the constant system, as in Ches- ter, the waste of water has been so great that the old plan has been re- curred to. But when the fittings are good there is real economy in the constant system, — as shown by the comparison between Lincoln and Oxford, and by Hawksley's evidence with reference to Norwich.^ Common taps do not answer, and the best screw taps and fittings must be used.* To prevent theft, it has been proposed to make the removal of fittings a specific offence, punished summarily by imprisonment, and to place the sale of such property under the same restrictions as in the case of Crown proj)erty. One important sanitary advantage of the constant system is that, in order to facilitate inspection and detection of waste, no waste-pipe is al- lowed to open into a sewer, but it is always so placed that any escape of water can be easily seen (the so-caUed warning pipe). The great evil of sewer gases being conducted back into houses through overflow pipes is thus avoided. Carefiol inspection and good fittings so far lessen the waste of the constant system, that in some cases less water is used than under the ijfctermittent plan. ^ iSh: G. Deacon, in a very interesting and instructive paper," has shown that the loss on the constant system is due to cau.ses over which the con- sumer has generally little or no control, and that it occurs for the most part before the water reaches him. It arises chiefly from leaks in pipes, drawn joints, and so on, and up to lately there was no means of detecting this in a way practically useful. By the introduction of his water-waste meter this is now done with the utmost precision and accuracy, so that now in Liverpool the_ expenditure of water has been reduced from 33.5 gallons per head per diem to 13.3, This does not mean any restriction to the con- ' The terms used to describe the pipes differ a little apparently ; the mains and district or sub-maius are the large pipes, which are always 'full of water, the latter being of course the smaller ; the service -pipe is another terra for a district main. The communication-pipe is that which runs from the service-pipe to the house, and in the house it takes the name of house-pipe. - Mr. Beggs' Pamphlet, op. cit. , p. 20. ^ See Report of Rivers Pollution Commission, vol. vi., p. 233. * A bad ball-cock has been known to drop 12 gallons a day. ^ Evidence of Mr. Easton in the Report of Committee on the East London Water Bills, 1867. « The Constant Supply and Waste of Water, by George F. Deacon, M. Inst. C. E., Journal of the Society of Arts, vol. sxx., p. 738, 1882. 16 PRACTICAL HYGIENE. sumer ; tlae supply is now absolutely constant and the use unlimited. But it means that formerly the consumer used only 13 gallons at the outside, whilst 20 gallons went to pure waste. Mr. Louttit ' stated that the Lam- beth Water Company was able by this means to reduce the expenditure from 35.09 to 15.28 per head. The general waste in London appears to be about 15 gallons per head out of a total of about 35. "With such a system of checking, the main difficulties of a constant supply seem to be solved, even if every consumer used the full 25 gallons laid down in this work. Some engineers have proposed what may be called a compromise be- tween the intermittent and constant systems. The objection to this plan is that cisterns are reintroduced, and their lessened size does not remove the objections to them. If the constant system is used, a good screw stop-cock, available to the tenant, should be placed at the point of the entrance of the pipe into the house, so that the water may be tiu-ned off if pipes biu'st, or to allow the pij)es to be empty, as diuing frost. Eveiy precaution must be taken that impure water is not di-a^Ti into the pipes by a pipe being emptied and sucking up water from a distance.^ For the sujDply of a very lai'ge city, it might be desu'able to divide the city into sections, and to estabhsh a resersoir for each district, holding thi'ee or four days' supply. In this way the waste of one section would not take away the water from another. In some instances, people in one pai-t of a town, supphed on the constant system, have used so much water for gardens that other paris have been altogether deprived of supply. The system of secondary reservou's would not only lessen this chance, but would make it possible to ascertain that every pai-t of the town was getting its supply. The number of water companies in London has in fact somewhat this effect, but the subdirision is not earned fai* enough. There is no doubt that the constant system is the safer, especially for poor houses, as it leaves no loophole for inattention in the cleansing of cisterns. Only, it recjuires that the constant system should reaUy fuMl the ' Discus-ion on Mr. Deacon's paper. /^ ' The Board of Trade issued a Minute in 1872, laying down regulations an«3eiin- ing the kind of fittings and arrangements for London. The following are the princi- pal points : lead pipes to be of certain strength (if internal diameter is f in., -i in., I in., f in., 1 in., 1^ in. , the respective weights per lineal yard are to be .5 Iti, 6 JT), 7^ It), 9 ft, 12 ft), 16 ft)). Every pipe in contact with the ground to be of lead ; each house to have a communication pipe, but only one, unless an owner has it for a block of houses ; connection of every communication pipe to be by a brass screwed ferule or Btop-cock witii a clear area of water-way equal to cne-half inch, every joint to be a " plumbing " or *' wipe " joint. No pipe to pass through an ash-pit. manure heap, drain, unless it cannot be avoided, and then the pipe is to be laid in an exterior cast- iron pipe or jacket ; each pipe in the ground to be thirty inches below surface ; each communication pipe to have near the entrance into the house a screwdown stop-valve: if in the ground such valve to be protected by proper cover and guard box ; every cistern to be water-tight, to have a good '" ball-tap ; " no waste-pipe except a '' warn- ing pipe," and such warning pipe to be so placed as to be easily inspected. Xo cistern buried in ground to be used ; wooden cisterns to have metallic linings ; every water- closet, urinal, or boiler shall be served only from a cistern, and shall not be in direct communication with the water-pipes ; closets and urinals to have water-waste pre- venters ; every •' down pipe "' into a water-closet to have an internal diameter of not less than '[i inch, and to weigh not less than 9 ft) per lineal yard. Xo bath to have an overflow pipe except of the '•warning" kind; the outlet must be di.stinct from the inlet, and the inlet shall be higher than the highest .«tand of the water. Lead warning pipes of which the ends are open, and which cannot remain charged with water, may have the following minimum weight : ^ inch in diameter to have a weight 3 ftj per yard ; f in., 5 ft) ; 1 in. , 7 lb. WATER. 1 7 conditions laid down for it, viz., it should deliver sufficient water at all times, and not merely delude us with a j)lu-ase. In both plans the water is conducted from the reservoii's in pipes. The pipes are comj^osed of u'on, masonry, or earthenware, for the larger pijDes or mains, the ii'on being sometimes tinned or galvanized, or lined with con- crete, or pitched, or covered with a vitreous glaze, such as that patented by De Lavenant ; for the smaller pipes, ii'on, lead, tin, zinc, tiimed copper, earthenware, gutta percha, etc., ai'e used. Pipes of artificial stone are now made. Iron is the best material for the larger pipes, and iron or non-metalhc substances for the smaller pipes. Water should be distributed not only to eveiy house, but to every iioor in a house. If this is not done, if labor is scarce in the houses of poor peojjle, the water is used several times ; it becomes a question of labor and trouble versus cleanliness and health, and the latter too often give way. Means must also be devised for the speedy removal of dii'ty water fi'om houses for the same reasons. In fact, houses let out in lodgings should be looked upon, not as single houses, but as a collection of dwellings, as they really are. ACTIOX OF WATER OX LE.AD PIPES. There are more discrepancies of opinion on this subject than might have been anticipated. From an analj^sis of most of the works, the following points appear to be the most certain : — 1. The waters which act most on lead are the purest and most highly oxygenated ; also those containing organic matter, nitrites (Medlock),' niti-ates,^ and according to several obseiwers, chlorides.^ Besides the por- tion dissolved, a film or cnist is often formed, especially at the time of contact of water and au' ; this crust consists usually of two parts of lead carbonate and one part of hydi-ated oxide. The mud of several rivers, even the Thames, will coiTode lead, probably fi-om the organic matter it contains, but it does not necessaiily follow that any lead has been dissolved in the water. Bits of mortar 'will also corrode lead. 2. The waters which act least on lead are those containing carbonic acid,^ calcium carbonate, calcium phosphate (which has been found by Frankland to have a gi-eat protective power), and in a less degree calcium sulphate, and perhajDs, in a still less degree, magnesian salts, and the alka- line phosphates ; ^ but it has been said that perfectly pure water, contain- ing no gases, has no action on lead. This, however, is not strictly coiTect, as pure distilled water has been known at Netley to take up lead from a leaden pipe. The deposit which fi-equently coats the lead consists of car- ^ Medlock attributes the greatest influence to ammonium nitrite formed from or- ganic matter ; lead nitrite is rapidly formed, and carbonate is then produced ; the nitrous acid bsing set free to act on another portion of lead. The ammonium nitrite exists in most distilled -vvater. "^ Pattison Muir attributes very powerful action to nitrates, but says that it is modi- fied or even arrested by the presence of carbonates, sulphate«, and chlorides, but there is some discrepancy of opinion as to the action of the chlorides. " Pattison Muir found that a solution of sulphate or chloride of ammonium of 0.04 per cent, took up 3.2 grains per gallon after exposure to lead for 505 hours. ■• M. Langlois (Uec. de Mem. deMed. Mill, 1865, p. 412' attributes a great action on lead to the carbonic acid, but states that the carbonate of lime entirely protects lead, apparently by rendering the carbonic acid inactive. ^ Report of the Government Commission, 1851, p. 7. 2 18 PRACTICAL IIYGIEXE. bonate, phosphate, and stilphate of lead, calcium, and magnesium, if the ■water have contained these salts, and lead chloiide.' 3. From the obsei-vations of Graham, Hofmann, and jMiller, the protec- tive influence of carbonic acid gas appears to be very great ; a difficultly soluble lead cai-bonate is foi-med. JHowever, a veiy gi-eat excess of free carbonic acid may dissolve this. This has perhaps led to the statement that carbonic acid countei'acts the preservative effects of the salts. Water chai'ged with carbonic acid under pressui'e has a very mai-ked solvent action on lead (Pattison Muh'). Other substances may find their way into "water which may act on lead — as vegetable and fatty acids, ai-ising from fruits, vegetables, etc., or sour milt or cider, etc. 4 The lead itself is more easUy acted upon if other metals, as iron, zinc, or tin, are in juxtaposition ; galvanic action is produced. Bending lead pipes against the grain, and thus exposing the structiu-e of the metal, also increases the risk of solution ; zinc pipes, into the comi:)osition of which lead often enters, yield lead in large quantities to water, and this has been especially the case -with the distilled water on board shii:)S. AMOX."XT OF DISSOL'S'ED L.EAD WHICH WELL PEOCrCE SYMPTOIIS OF POISOXIXG. Dr. Angus Smith refers to cases of lead paralysis in which as little as -j-Kth of a gi-ain per gallon was in the water. Adams ^ also speaks of ^^^Tyth of a gi-ain causing poisoning. Graham speaks of J-th of a grain per gallon as l>eing innocuous. Angus Smith says that J^jth of a gi-ain per gallon may affect some persons, while ^V^^ ^^ ^ grain per gallon may be requii-ed for others.^ But it is difficult to prove it may not at some time have been more than this. Ciilvert found that water which had been decidedly injuri- ous in Manchester contained from ^V^^^ ^o j^o^^^ *^^ ^ grain jDcrgallon. In the celebrated case of the poisoning of Louis Phihppe's family at Claremont, the amount of lead was -i\ths of a gi-ain per gallon ; this quan- tity affected 3-4 per cent, of those who di'ank the water. The water of Edinbiu-gh is said to contain only yj^r^^ ^^ ^ grain per gallon, which is not hurtfvil* On the whole, it seems probable that any quantity over ^V^^ ^^ ^ grain per gallon should be considered dangerous, and that some persons may even be affected by less quantities.^ • PBOTECTION OF LEAD PIPES. The chief means which have been proposed are : — [a) Lining with tin. Calvert's expeiiments "^ show that extra tinned and ordinaiy tinned lead piping both gave up lead to the piu-e water now used at Manchester. (b) A much better j^lan is by having a good block-tin pipe enclosed in a lead pipe, as in Haines' patent. If the tin is good, it is httle acted on, and the strength of the pipe is increased, while bends and junctions can be ' Lauder Lindsay, Action of Hard Water on Lend, p. 7. * Trans of the American Medical Society. 1852, p. 10.3. ' Wanklyn adopts i\,th of a g'l ain per gallon as justifying rejection of a water ; ^^fth would probably be a safer limit. * Chemical News. September 28, 1861. * See also Taylor's Med. Jurisp.. 1865, p. 242 ; and opinions of Penny, ibid , p. 241. * Chemical News, September 28 1861. ■^ATER. 19 made TvitJbout clestroving tiie continuity of the tin. The composite j^ipes of this kind made by Messi-s. '\\'alk:er, Parker & Co. are said to -withstand any amount of torsion. On the authoiity of Professor J. Emerson Rey- nolds, F.E.S., it is said that lead alloyed with 3 per cent, of tin is not acted upon by Tvater ; " pipes of this kind appear to be used in Dublin and in Glasgow. Later experience with this alloy, however, seems to have modi-' tied the good opinion first held of it ; it is ceriainly inapphcable to cisterns, or for any purpose where it is more or less exposed to the aii'. (c) Fusible metal, \iz., lead, bism.uth, and tiru This is certainly objec- tionable. (d) Bituminous cqating (M'Dougall's patent). This is said to be effec- tual, but no exact experiments have been recorded. (e) Various gums, resins, g"utta-percha, and india-rubber. These would probably be efficacious, but there does not seem to be any evidence to show how long they will adhere. (/) Coating interior of pipes with lead sulphide by boiling the j^ipes in sodium stdphide for fifteen minutes. The sodium sulphide may be made by boiling suljDhur in hquor sodte. (Schwai'tzs patent. j (g) Tarnish of coal tar.' SUBSTITTTES FOE LEAD PIPES, Cast and wi'ought u'on j)ipes can be used, and ^Ir. Piawlinson now orders no others. The u'on can be glazed internally. ^ Copper tinned and block-tin are also employed, and both are excellent, but are rather expen- sive. In some cases the tin is eaten thi'ough, but this is not common." SECTION n. QUALITY OF DEIXKIXG WATER. Scb-Sectiox I. — Coixposinox. The composition of water is of importance for several economic pur- poses ; for certain trades which requii'e careful pi-ocesses of washing and dyeing ; for the supply of engines, etc. But these subjects are too techni- cal to be discussed here, and this chapter is therefore restricted to the Cjuahty of water as used for drinking pui-poses. The only domestic matter of imj)ortance connected with quality, apaii- fi'om drinking and cooking, is the relative amount of soap used by hard and soft water in washing. But this is so obrious a matter that it only requires to be alluded to. 0^ving to many of the domestic uses of water, such as the washing of ' Manual of Hygiene for Ireland, p. 218. Professor Cameron, of Dublin, corrobo- rates this statement, Manual of Hygiene, p. 86. - Lauder Lindsay, Action of Hard Water on Lead, p. 21. ^ Iron pipes coated inside with Angus Smith's bituminous varnish are a good deal used. In experiments made at Xetley these %Yere found to yield a distinct taste of tar to the water for a considerable time ; after a time, however, this action was much diminished, but did not entirely cease. Probably Barff's process of producing a surface of magnetic oxide on iron will come into use. For joining pijDes Spence's metal will probably prove useful. * I have seen block-tin pipes eaten through by water at Woolsten, apparently in consequence of the presence of nitrates. Zinc pipes, which have been recommended, are objectionable as likely to yield poisonous sales to such waters. — [F. de C] 20 Pii ACTIO AL HYGIENE. utensils, the supply for closets, etc., not requiring a very pure water, it lias been proposed in some cases to supply water from two sources — one pure for drinking and cooking, the other impure. This requires, however, two sets of pipes, and involves the chance of mistake between two waters ; and it is only likely to be of use under exceptional circumstances. Drinking water is supplied from shallov\r, deep, and Ai-tesian weU sources : rain, rivers, weUs, springs, etc. Rain Water. — As it falls through the air, rain becomes highly aerated (average, 25 cubic centimetres per litre), the oxygen being in larger pro- portion than in atmospheric air (32 per cent., or a little more) ; carbon dioxide constitutes 2^ or 3 per cent, of the gas. It carries down from the air ammoniacal salts (carbonate, nitrite, and nitrate), and nitrous and nitric acids in small amount. The total quantity of nitrogen in ammoniacal salts, nitrous and nitric acid, is .0985 parts per 100,000. Frankland puts the average at .032. At Montsoui-is, ' mean of seven years, the ammonia amounted to .193 per 100,000, or 9.135 gi-s. per gallon ; the nitric acid (NOg), mean of six years, to .354 per 100,000, or .248 per gallon. This gives a total nitrogen, from ammonia and nitric acid, of .239 per 100,000. Tn towns with coal-fires it takes up sulphiu'ous and sulphuric acids, and sometimes hydrogen sulphide. The sulphates in rain increase, according to Dr. Angus Smith, '^ as we pass inland, and before large towns are reached ; they are, according to this author, " the measure of the sewage in air " when the sulphur derived from the combustion of coal can be excluded, but in this country the exclusion could never be made. Free acids are not found with certainty, according to Smith, when combustion and manufac- tures are not the cause. The acidity taken as sulphuric anhydride was equal to .0097 grain per gallon of rain in a country place in Scotland, and 1.0589 grain in Glasgow ; in Manchester in 1870 it was .8416, and in London, .2713 gi-ain. The nitric acid 'in Glasgow was as much as .1705 grain per gallon, and in London only .06188. Albuminoid ammonia was no less than .326 part in a million in London rain.^ Rain also carries dowTQ many solid substances, as sodium chloride, in sea air ; calcium car- bonate, sulphate, and phosphate ; ferric oxide ; carbon.'' It almost always contains also a httle nitrogenous organic matter, amounting in extreme cases to as much as .35 grain per gallon. The total amount of solids from five analyses quoted by Moleschott, was 0.032 gramme per htre, or 224 grains per gallon, and from 63 samples bv Frankland, 3.86 per 100,000, or 2.701 per gaUon.' ' Annuaire de I'observatoire de Montsouris pour I'au 1882. 2 Air and Rain, 1873, p. 245. ^ Angus Smith, op. cit , p. 363. * An ingenious plan for removing suspended matter from rain-water is supplied by Buck's " Patent Percolator," which may be attached to the pipe supplying a rain-water tank. It works automatically and produces good results, although at the expense of considerable waste of the water. '- In rain-water collected at St. Albans, in the middle of an arable field, two feet from the ground, Frankland found as much as 8.58 parts in lOO.OCO or 6.006 grains per gallon ; from the roof of the Land^ End Hotel (Cornwall) 42.8 per 1(10,000, of which one-half was chlorides. In a sample from supply tank in officers' quarters at Portland I found 47.05 gr. per gallon of solids, of which about 10 were chlorides ;'*'ohe organic constituents were also very large. In another sample, gathered as collected, o2. 55 total"s^Uds and 14 chlo- rides; .Tud in one from a pipe leading to the cookhouse. 59.25 total solids and 15.2 chlorides. In a ^sample collected through funnels direct into glass bottles, the solids were 6.65 per gallon, of which 4.9 were volatile, chiefly ammonium chloride, etc. — [F. de C] WATEE. 21 Occasionally microscopic plants of the lowest order (as Protococcus j:)luvialis and others) are present, and in towns the debris arising from street dust. With regard to Rain as a Source of Supjoly. — The uncertainty of the rain- fall from year to year, the length of the dry season in many coimtries, and the large size of the reservoirs which are then required, are disadvantages. On the other hand, its general purity and its great aeration make it both healthy and pleasant. The gTeatest benefits have resulted in many cases (especially in some of the West Indian Islands) from the use of rain instead of spring or well water, which is often largely impregnated with earthy salts. In all places where the spring or well water is thus bad, as in the neutral ground at Gibraltar, rain-water should be substituted. So also it has been suggested that in outbreaks of cholera anywhere, the rain-water is less likely to become contaminated with sewage matters than wells or springs, into which organic matters often find their way in an unaccounta- ble manner. Ice and Snoio Water. — In freezing, water becomes purer, losing a large portion of its saline contents. Even calcium carbonate and sulphate are partially got rid of. The air is at the same time expelled. Ice-water may thus be tolerably pure, but heavy and non-aerated. Snow-water contains the salts of rain-water with the exception of rather less ammonia. The amounts of carbonic acid and air are very smaU. There has long been an opinion that snow-water is unwholesome, but this, if it be true, is probably due to impurities. Ice and snow often con- tain a good deal of suspended organic matter. Dr. Baker Edwards of Montreal found 2 grains per gallon in the shore ice and 1 grain per gallon in the river ice.' In Northern Europe, the poor classes have the habit of taking the snow lying about their dwellings, and as this is often highly impure with substances thrown out from the house, this water may be un- wholesome. It has been conjectured that the spread of the cholera in the Russian wiiiter in 1832 was owing to the use of such snow-water cont.ami- nated by excretions. Ice and snow may also be the means of conveying malarious poison to places at a distance.^ Dew has occasionally been a source of supply to travellers in sterile regions in South Africa and Australia, on board ship. Spring, Well, and River Water. — The rain falhng on the ground partly evaporates, partly runs off, and partly sinks in. The relative amounts vary with configuration and density of the ground, and with the ch'cum- stances impeding or favoring evaporation, such as temperature, movement of air, etc. In the magnesian Hmestone districts, about 20 per cent, pene- trates ; in the new red sandstone (Triassic), 25 per cent. ; in the chalk, 12 ; in the loose Tertiary sand, 90 to 96. Penetrating into the groimd, the water absorbs a large proportion of car- bonic acid from the air in the interstices of the soil, which is much licher (250 times) in CO^ than the air above. It then passes more or less deeply into the earth, and dissolves everything it meets with which can be taken up in the time, at the temperature, and by the aid of carbonic acid. In some sandy soils there is a deficiency of C0„, and then the water is also wanting in this gas, and is not fresh and sparkhng. ^ Further evidence of the impurity to be sometimes met with in ice will be found in the Reports of the State Board of Health of Massachusetts, vols. vii. and x. '•^ See paper by C. Smart, M.B.. CM., Captain and Assistant- Surgeon, United States Army, " On Mountain Fever and Malarious Water," American Journal of the Medical Sciences, Jan., 1878. See also Report on Hygiene, A.M.D. Reports, vol. six. 22 PRACTICAL HYGIEXE. ^Tlie cliemical changes and decompositions wliich occur in the soil by the action of cai-bonic acid, and which are probably influenced bv diffusion, and perhaps pressui-e, as vrell as bv temperatui-e, are extremely curious, ' but cannot be entered upon here. The most common and simple ai-e the solution of calcium carbonate, and the decomposition of calcium and sodium sihcate by carbonic acid, or alkaline cai'bonates. Salts of ammonia, also, when they exist, appear fi-om Dietrich's observations to have a consider- able dissolving effect on the sihcates. Fed from a variety of soui'ces, river-water is even more complex in its constitution than spidng-water ; it is also more influenced by the season, and by cii'cmnstances connected with season, such as the melting of snow or ice, rains and floods, etc. The water taken on opposite sides of the same river has been found to drffer shghtly in composition. The general result of solution and decomposition is, that the water of spi-ings and rivers often contains a great number of constituents — some in very small, others in gi'eat amount. Some waters are so highly charged as to be termed mineral watei-s, and to be unfit for diinking, except as medi- cines. The impiuities of water are not so much influenced by the depth of the spiing as by the strata it passes thi-ough. The water of a surface sj)ring, or of the deepest Ai-tesian well, may be piu-e or imjiiu-e. The tem- peratui'e of the water also varies, and is chiefly regulated by the dej)th. The temperatui'e of shallow springs altera with the season ; that of deeper spiings is often that of the yeai'ly mean. In veiw deep sjjiings, or in some Aiiesian wells, the temperatui-e of the water is high. The substances which are contained in sj^ring, river, and well waters ai'e noted more fully under the head of "exa^iixation of water." There may be susjDended matters, mineral, vegetable, or animal ; dissolved gases, viz., niti'ogen, oxygen, cai'bon dioxide, and in some cases hydi-ogen sul- phide, and carbiu'etted hydi-ogen ; and dissolved sohd matters,' consisting of hme, magnesia, soda, potassa, ammonia, ii-on, alumina, combined with chloiine, and sulphiuic, carbonic, phosj)horic, nitiic, nitrous, and sihcic acids. More infrequently, or in special cases, certain metals, as arsenic, manganese, lead, zinc, and copper, may be present. The mode of combination of these substances is yet uncertain ; it may be that the acids and bases are equally distributed among each other, or some other modes of combination may be in play. The mode of combina^ tion may usually be assumed to be as follows. The chemist determines the amount of each sejDai'ate substance, and then calculates the combina- tion as follows. The chloiine is combined with sodium ; if there is an excess, it is combined with potassium or calcium ; if there is an excess of soda, it is combined with suli^huric acid, or if still in excess, with carbonic acid. Lime is combined with excess of chloiine, or sulphiuic acid, or if there be no sulphuiic acid, or an excess of hme, with cai'bonic acid. Mag- nesia is combined with carbonic acid. So that the most usual combina- tions are sodium chloride, sodium sulphate, sodium carbonate, calcium carbonate (held in solution by cai'bonic acid), calcium sulphate, calcium chloride and sihcate, and magnesium carbonate ; but the results of the analysis may render other combinations necessaiy. Distilled Water. — Distillation is now veiy largely used at sea, and af- fords an easy way of getting good water from sea or brackish water. Almost ' These are given in detail by G Bischof, Chemical and Phj'sical Geology (Caven- di>h Society's edit. ), 18o4. vol i., p. 2 et seq. ; and in Watt's Dictionary of Chemistry, Article '• Chemistry of Geology," by Dr. FauL WATER. 23 any form of apparatus will suffice, if fuel can be procured, to obtain enough water to support life ; and if even the simplest apphances are not attainable, the mere susjjension of clean woollen clothing over boihng water will enable a large quantity to be collected. At sea, salt water is sometimes mixed with it from the priming of the boilers, and occasionaUy from decomposi- tion of magnesium chloride (probably), a httlefree hydi'ochloric acid passes off. This can, if necessary, be neutralized by sodium carbonate. As distnied water is nearly free from au", and is, therefore, unpalatable to some persons, and is supposed indigestible,^ it may be aerated by allow- ing it to run through a cask, the bottom of which is pierced with fine holes, so as to expos3 the water to the ah-. Plans for aerating the water distiUed from sea-water have been proposed by Normandy and others, and are used in many steamers. Organic matter, at first offensive to taste and smell in distnied water, can be got rid of by passing through a good filter, or by keeping three or four days, or by the addition of a httle permanganate solution. Care should be taken that no lead, zinc, or copper finds its way into the distnied water. Many cases of lead poisoning have occuiTcd on board ships, partly from the use of minium in the apparatus, and partly from the use of zinc pipes containing lead in their composition. If possible, block tin should always be used. Comparative Value of Spring, Paver, and Well Water as Sources of Supply. This depends on many circumstances. Spring- water is both pure and impure in different cases ; and the mere fact of its being a spring is not, as sometimes imagined, a test of goodness. Frequently, indeed, river- water is purer than spring- water, especially from the deposit of calcium carbonate ; organic matter is, however, generaUy in greater quantity, as so much more vegetable matter and animal excreta find theu' way into it. The water of a river may have a very different constitution from that of the springs near its banks. A good example is given by the Ouse, at York : the water of this river is derived chiefly from the millstone gTit which feeds the Swale, the Ure, and the Nid, tributaries of the Ouse ; the water contains only 9 gTains per gallon of salts of calcium, magnesium, sodium, and a lit- tle u'on. The weUs in the neighborhood pass down into the soft red sand- stone (Yore dale series) which hes below the millstone grit ; the water con- tains as much as 64.96 grains, and even, in one case, 96 grains per gaUon ; in addition to the usual salts, there is much calcium chloride and calcium, sodium, and magnesium nitrates. Shallow well-water is always to be viewed with suspicion ; it is the natural point to which the drainage of a good deal of surrounding land tends, and heavy rains will often wash many sub- stances into it.^ The cjuestion may arise as to what should be considered a shallow, and what a deep weU. In the Pdvers Pollution Commissioners' Sixth Report all the shallow weUs examined are less that 50 feet deep ; most of the deep wells more than 100 feet deep. Any well less than 50 feet deep that does not pass through an impermeable stratum, such as stiff clay or ' By some even dangerous (Gerardin). ^ Dr. Cameron (Dublin Journal of Medical Science) cites a case where good and bad water were obtained from different levels in the same well. Similar results have been observed elsewhere ; see analysis of water from a well at Fareham, Report on Hygiene, A.M.D. Reijoris, vol. xxi. In these cases both samples were impure, but the water from the bottom of the well contained a great excess of salts, due probably to infil- tration from the tidal waters of the neighboring river. 24 PRACTICAL HTGIEi^E. hard rock, must be classed as a shallow welL The following table is given by the Rivers Pollution Commissioners : — ' Wholesome -| 2. Deep well-water, . \ ^ 1 ' ' 3. Upland sm-face-water, Moderately palatable. Q . . j 4. btored ram-water, . \ ■ -^ auspicious -j g Surface-water from cultivated land, . . ) ■p. \ 6. River-water, to which sewage gains access, >- palatable. IJangerous -j ^^ Shallow weH-water, ) Sub-Section II. — Ch-\r.\cteks and Classitication of Dkinking Watees. The general characters of good water are easily enumerated. Perfect clearness ; freedom from odor or taste ; coolness ; good aeration ; and a certain degTce of softness, so that cooking operations, and especially of vegetables, can be properly performed, ai'e ob^dous properties. But when we attempt a more complete description, and assign the amounts of the dissolved matters which it is desu-able should not be exceeded, we find con- siderable difference of opiuion, and also a real want of evidence on which to base a satisfactory judgTaent. Still an hygienic classification or enumeration of potable waters, based on such facts as are generally admitted, will be useful. A di\-ision of waters used for diinking into four classes has been adopted in this work : — 1. Pui'e and wholesome water. 2. Usable 3. Suspicious " 4. Impure " The waters belonging to the first and second class may be used ; those of the third, or suspicious class, should be well filtered before distribution, and, if possible, should be again filtered in the house. A jDui-er source should also be obtained if possible, and soui'ces of sewage contamination ascertained and prevented. The waters of the foiu'th class should be enth-ely disused, or only be used when a better source is not procurable, and means of pui'ification should then be systematically resorted to. Sub-Section IH. — Origin of the Impurities in Drinking Water. The origin of the impurities in water may be conveniently refen-ed to four heads, ^iz. : — (1) Substances derived from the som-ce ; (2) Substances added duiing the flow of the waters in rivers, canals, aqueducts, or other conduits ; (3) Impui'ities caused by storage in resei'\'oirs or tanks ; and (4) Substances added during distribution from resei-voii's either in pipes or water baiTels, or in house cisterns. 1. Impurities of Source. The geological formation of a district necessarily influences the com- position of the water running thi-ough it, though it is impossible to teU \rith absolute certaiaty what the constituents of the water may be. For- mations vary greatly, and the broad features laid down by geologists do » Sixth Report, p. 129. WATER. 25 not always suffice for our purpose. In the middle of a sandy distiict, ;^-ielding usually a soft water, a liard selenitic "svater may be found ; and instead of the pure calcium cai'bonate water, a chalk well may jield a water hard fi-om calcium sulxohate and iron. Still it may be useful to give a short sununaiy of the best known facts. 1. The Granitic, 2Ietamorphic, Trap-Rock, and Clay-Slate Waters.— Generally the gi-anitic water is very pure, often not containing more than 2 to 6 gTains -^ev gallon of sohds, viz., sodium carbonate and chloride, and a httle lime and magnesia. The organic matter is in very small amount. The clay-slate water is generally very pure, often not containing more than from 3"^ to 4 gTains per gallon. The water fi-om hai'd trap-rocks is pm-e, but if the trap be disintegi-ated the shallow wells sunk in it ai-e of course hable to be fouled by surface washings or soakage. 2. The Water from JTillstone Grit and Hard Oolite. — Like the granitic water this is very pure, often not containing more than 4 to 8 gTains per gallon of mineral matters, which consist of a httle calcium and mag-nesium sulphate and cai-bonate ; a trace of u'on. 3. Soft Sand-Rock Waters. — These ai'e of vaiiable composition, but as a rule are impure, containing much sodium chloride, sodiiun carbonate, sodium sulphate, h'on, and a httle hme and magTiesia, amounting alto- gether to from 30 to 80 grains x^er gallon. The organic matter may be in large amount — 4 to 8 gTains j)er gallon, or even more. Sometimes these waters are pure and soft, but in other cases wells or springs, within a short distance, may vary considerably in composition. 4. The Loose Sand and Gravel Wate7\'-. — In this case there is also a great variety of composition. Sometimes the water is very pure, as in the case of the Famham waters, and in some of the waters from the green sand, where the total solids ai'e not more than fi-om 4 to 8 grains per gahon, and consist of a httle calcium carbonate, sulphate, and sihcate ; magnesium carbonate ; sodium and potassium chloride ; sodium and po- tassium sulphate ; iron, and organic matter. The last is sometimes in some amount, viz., .8 to 1.8 grain per gallon. In tolerably pm-e gTavels, not near towns, the water is often very fi-ee from impuiity. In the case of many sands, however, which are rich in salts, the water is unpiu-e, the sohd contents amounting sometimes to 50 or 70 gTains per gallon, or more, and consisting of sodium chloride, sodium carbonate, sodium sulphate, with calcium and magTiesium salts.' These waters are often alkaline, and con- tain a good deal of organic matter. The water fi'om the sands in the " Landes " (Southern France) contains enough organic matter to give agTie. 5. Watei's from the Lias Clays vai-y in composition, but are often impure ; even 217 gi-ains per gallon of mineral matters have been found. No less a quantity than 88 gTains of calcium sulphate, and 41.8 of magne- sium sulphate, existed in a water examined by Yoelcker." 6. The Chalk Waters. — The pui-e, typical, calcium carbonate water from the chalk is very spai'khng and clear, highly charged with carbonic acid, and contains from 7 to 20 gTains per gallon of calcium carbonate, a Httle magnesium carbonate and sodium chloride — small and immaterial quantities of u-on, sihca, potassa, nitric, and phosphoric acids. Sulphuric 'In a shallow vvell (20 feet deep) in the gravel, near Netley Abbey, the water yielded total solids 148.75, of which were chlorides 86.80 grains per gallon; after de-epening it to '60 feet, and passing through a stratum of stifE blae clay, it gave only 16.8 total solids, and 6.5 of chlorides. — [P. de C] '■^ In a well from Weedon Barracks, 109 feet deep, sunk in blue lias, I found 91 grains per gallon of solids, but very little organic matter. — [F. de C J 26 PE ACTIO AL HYGIENE. acid in combination is sometimes jiresent in variable amount ; organic matter is usually in small amount. This is a good, wholesome, and pleas- ant water. It is hard, but softens gTeatly by boiling. ' 7. The Limestone and Magnesian Limestone Wate7\s. — These are also clear spai-kHng waters of agreeable taste. They differ from the chalk in containing usually more ctdcium sulphate (4 to 12 grains, or even more) and less carbonate, and, in the case of the dolomitic districts, much mag- nesium sulphate and carbonate. Organic matter is usually in small amount. They are not so wholesome as the chalk waters. They are hai'd, and soften less on boihng. 8. The Selenitic Waters. — Water charged with calcium sulphate (6 to 20 grains, or even more) may occur in a variety of cases, but it may some- times come from selenitic rocks. It is an unwholesome water, and in many persons produces dyspepsia and constipation, alternating with diar- rhoea. It is hard, softens little on boihng, and is not good for cooking or washing. 9. Clay Waters. — Very few springs exist in the stiff claj' ; the water is chiefly surface, and falls soon into rivers ; it varies gTeatly in composition, and it often contains much suspended matter, but few dissolved constitu- ents, chiefl}' calcium and sodium salts. 10. Alluvial Waters. — (Alluriimi is usually a mixtiu-e of sand and clay.) Generall}^ impure, with calcium carbonate and sulphate, magnesium sul- phate, sodium chloride and carbonate, ii-on, sihca, and often much organic matter. Occasionally the organic matter oxidizes rapidly into nitrites, and if the amount of sodium chloride is large, it might be supjDosed that the water had been contaminated "with sewage. The amount of solids per gal- lon varies from 20 to 120 grains, or even more. 11. Surface and Subsoil Water. — Very variable in composition, but often very imj^ure, and always to be regai'ded with suspicion. Heaths and moors, on primitive rocks, or hard mUlstone gi'it, may suj^ply a pure water, which may, however, be sometimes shghtly colored with vegetable matter. Cultivated lands, with rich manvu-ed soils, give a water containing often both organic matter and salts in large quantity. Some soils contain potassium, sodium, and magnesium nitrates, and give up these salts in large quantity to water. This is the case in several parts of India, at Aden, and at Nassick in the Deccan (Haines). In towns and among the habita- tions of men, the sui'face-water and the shallow well-water often contain large quantities of calcium and sodium nitrites, nitrates, sulphates, jDhos- phates, and chlorides. The nitrates in tliis case probably arise from ammonia, ammonium nitrite being first formed, which dissolves large quantities of Hme. Organic matter exists often in large amount, and slowly oxidizes, forming nitric acid and ammonia. In some cases butyric acid, which often unites with lime, is also formed. 12. Marsh Water. — This always contains a large amount of vegetable organic matter ; it is not vmusual to find from 12 to 40 gi-ains, and in some cases even more. Suspended organic matter is also common. The salts are variable. A. little calcium and sodium in combination with cai*bonic and sulphuric acids and chlorine are the most usual. Of course, if the marsh is a salt one, the mineral constituents of sear-water are jDresent in var\'ing proportions. _^_ » ^____^ ' Sometimes the water drawn from the upper part of the chalk is really derived from tertiary sand lying- above the chalk. The water contains less calcium carbonate, and more sodium carbonate and chloride, and may be alkaline. WATER. 27 13. Water from Graveyards. — Ammonium and calcium nitrites and nitrates, and sometimes fatty acids, and much organic matter. Lefort found a well of water at St. Didier, more than 330 feet from a cemetery, to be largely contaminated with ammoniacal salts and an organic matter which was left on evaporation. The water was clear at first, but had a vapid taste, ajid speedily became putrid. 14. Artesian Well- Water. — The composition varies gTeatly. In some cases the water is so highly charged with sahne matter as to be undrink- able ; the water of the Artesian well at Grenelle contains enough sodium and potassium carbonates to make it alkaline ; there is also often a con- siderable amount of ' free or sahne ammonia. In some cases the water contains an appreciable amount of iron ; in other cases, especially when drawn from the lower part of the chalk, or the green sand below it, it is tolerably pure. Its temperature is usually high in proportion to the def)th of the well. The aeration of the water is often moderate, sometimes nil. These last two points sometimes mihtate against the employment of water from very deej) wells. 15. Water from Wells near the Sea.'' — This frequently contains so much saline matter as to taste quite brackish, although the organic matter may not be very large. In some samples from Shoeburyness (analyzed at Netley) the total solids ranged from 104 to 218 grains per gallon of total solids, the chlorides being from 22 to 65 : mean of six samples — 165 total solids, and 35 of chlorides. In one sample, however, the albuminoid ammonia was only 0.07 per million, and in five the oxygen required for organic matter was under 0. 75 per million. At Landgaiard Fort, water from a boring 150 feet deep yielded more than 500 grains of solids and 380 grains of chlorides. 16. Rain-Water may be contaminated by washing the air it falls through, but more by the STU-face on which it faUs, such as decaying leaves, bu-d droppings, soot, or other matter on the roofs of houses ; it also takes lead from lead coatings and pipes, and zinc from zinc roofs. 2. Impurities of Transit teom Source to Reservoirs. Open conduits are liable to be contaminated by surface washings carry- ing in finely divided clay, sand, chalk, and animal matters from cultivated land ; and the leaves and branches of trees and their contingent of vege- table matters. These impurities may occur in most cases, but in addition the refuse of houses, trades, and factones is often poured into rivers, and all sorts of matters are thus added. These impurities are broadly divided by the Rivers Pollution Commis- sioners into "sewage "and "manufacturing:" under the former term all solid and liqiiid excreta, house and waste water, and in fact aU impurities coming from dwelhng's are included ; under the latter term are placed all manufacturing refuse, such as from dye and bleach works, tanneries, paper- making, woollen, silk, and metal works, etc.^ The very numerous animal and vegetable substances derived from habi- tations are usually classed imder the vague, but convenient term of " organic ' For a good example of the iDfluence of a tidal river on neighboring wells, see my Lectures on State Medicine, Table x., p. 91. — [F. de C] On the other hand, springs situated near the sea have been found very pure. ^ For a full account of all these impurities, and the best mode of dealing with them, the six Reports of the Hiver Pollution Commissioners must be referred to. 28 PRACTICAL HYGIENE. matter," as the separation of the individual substances is impossible. The organic matter is usually nitrogenous, and Frankland has proposed to ex- press its amoxmt in terms of its nitrogen (organic nitrogen), but this view is not yet generally received on account of the difficulty of estimating the very small quantity of nitrogen. The nitrogenous organic matter undei'- goes gi-adual transformation, and forms ammonia, and nitrous and nitric acids. The exact steps of this process are perhaps complicated. On keep- ing the water the nitrites disapjoear, and in some cases the nitrates also gradually diminish, probably from the action of bacteria. A. Miiller ' found the residue of a well-water gave "with sodium hydi'ate a herring-LLke odor, which seemed like trimethylamme. Many of the "organic matters" in water are not actually dissolved, but are so finely suspended that they pass through filtering paper. There is no doubt that among this " suspended organic matter " many small plants and animals are always included. It is probably owdng to the variation in the quantity of suspended organic matter (living and dead) that water from the same soiu'ce sometimes gives different results on anatysis, even though the water be taken at the same time. Diuing its flow in open conduits, however, a species of purification goes on, by means of subsidence, the action of water-plants, and to some moderate extent by oxidation. On the whole these processes apjoear in India to render river-water, in spite of all the. contaminations it receives, purer than tank and well-water." The free- dom from noxious substances is also aj)parently gi-eater in India in the quick-running streams, which may also depend upon purification taking place in them.' 3. Impurities of Storage. The chance of substances getting into the water of wells, and tanks,* and even of cisterns in houses, is very great. Sui'face washings and soak- age contaminate wells and tanks, and leakages from i:)ipes, j)assage of foul air tlu'ough pipes, or direct absoi-ption of air by an uncovered surface of water, introduce impiuities into cisterns.'' It is singular in how many ways cisterns and tank waters get foul, and what care is necessary not only to place the cistern under safe conditions at first, but to examine it from time to time to detect contamination of the water. In India, especially, the tank water is often contaminated l^y clothes washed near, or actually in, the tank ; by the passage even of excrement directly into it, as well as by sui'face washings, so that in fact in some cases the village tank is one of ' Roth and Lex, Militar-Gesundheitspfl. , p. 16. ' Palmer shows this clearly in a very interesting paper in the Indian Medical Gazette for December, 1870. ^ Much influence has been ascribed to oxidation, and doubtless in part correctly ; but Dr. Frankland has shown its effect to be limited. The Irwell river, after pai-sing Manchester, runs 11 miles to its junction with the Mersey without further material pollution, and falls over 6 weirs ; yet the purification by oxidation is trillinir. By siphoning water from one vessel to another so as to represent a run of 96 miles, the organic carbon was only reduced 6.4 per cent, and the organic nitrogen 28.4 per cent. This, however, is widely different from running in an open river bed. •* In two examples of (.^o called) rain-water collected in tanks in the marsh near Tilbury Fort for the use of the troops, the solids were found to be respectively 41 and 145 grains per gallon (Army Medical Reports, vol. xvii. . p. 214). ^ A good case of ab.sorption by an open cistern of gases from water clo.«ets and urinals is recorded by Druitt (Medical '1 imes and Gazette, September, 1869). The water as supplied contains .08 part per million of albuminoid ammonia ; after absorp- tion, 17 parts. WATER. 29 tlie chief causes of the sickness of the people. There is, perhaps, no point on which the attention of the sanitary officer should be more constantly fixed than that of the storage of water, either on the large or small scale. In shallow wells (4 to 30 feet deep) the soakage water from the gTound in loose soils of chalk and sand is often very impure. Thus in a town the well-water often shows evidence of nitrites, nitrates, and ammonia, and chlorine far in excess of river-water in the neighborhood, though the strata are the same.' Occasionally, by constant passage of the water, a channel is formed, which may suddenly discharge into the well ; and prob- ably some of the cases of sudden poisoning from water have thus arisen. A well drains an extent of gTound about it nearly in the shape of an inverted cone. The area must depend on the soil ; but the experiments at Grenelle and Passy show that the radius of the area drained is equal to four times the depth at least, and that it often exceeds this.^ Professor Ansted states that the deepest (non-Aj-tesian) well will not drain a cone which is more than half a mile in radius. In some cases a well at lower level may receive the drainage of siu-- rounding hills flowing down to it from great distances. Good coping stones, so as to protect from surface washings ; good masonry for several feet below the siu-face of wells in very loose soils, so as to prevent super- ficial soakage, are necessary in all shallow weUs. 4. Imptjeities of Distribution. If water is distributed by hand, i.e., by water-carts, barrels, or skins, there is necessarily a great chance of its being fouled. In India, where the water is generally carried by water-carriers (Bhisties), inspection of the carts or skins should be systematically made, and whenever it be pos- sible, pij)es should be substituted for the mde method of hand conveyance. But even pipes may contaminate water ; metals (lead, zinc, and iron) may be partly dissolved ; wood rots, and if the pipes are occasionally empty, impure air may be drawn into them, and be afterward absorbed by the water. ^ In towns supplied on the constant system, when the pipes are be- coming empty the flow of water from a tap has drawn foul water or air through a pipe at some distance, and in this way even the water of the mains has been befouled. Coal gas passing into the ground from leaking of gas-pipes sometimes finds its way into wells, or even into water-pipes. In Berlin, in 1864, out of 940 pubhc wells, 39 were contaminated by admixture with coal gas. A good instance is related by IVIr. Harvey,^ where the main pipes were often empty and gas penetrated into them. Having regard to the cases in which gases from the soil (from leaking gas-pipes, sewers, etc.) find their way into water-pipes, it would seem important not to lay down water-pipes near any other, or, what is better, have all pipes in sub-ways where they can be inspected. ■ Eoth and Lex, op. cit , p. 43. ^ Etudes sur le mouvement des Eaux, par J. Dupuit. ^ Cases of this sort are given in the Reports of the Medical Officer of the Privy Council, No. ii., new series. See Dr. Blaxall on Fever at Sherborne, Dorset, and Dr. Buchanan on the Fever at Caiua College, Cambridge. In the latter case foul trap- water was sucked in from the closets. At Croydon, blood was sucked in this way from a butcher's shop. * Food, Water, and Air, February, 1872, p. 68. 30 PRACTICAL HYGIENE. SECTION m. ' PURIFICATION OF WATER. Without Filtration. 1. Exposure to Air in divided Currents. — This was fi plan proposed by Lind, for the water of the African west coast, more than one hundred years ago, and frequently revived since. The water is simply poured through a sieve, or a tin or wooden plate, pierced with many small holes, so as to cause it to fall in finely divided streams, or a hand-jDump is in- serted in a cask of water, and the water is pumped up, and made to fall through perforated sheets of tin. It soon removes hydrogen sulphide, offensive organic vapors, and, it is said, dissolved organic matter. The same plan has been used in Russia on a large scale, the Avater being al- lowed to fall down a series of stej)s, jiassing through wire gauze as it does so. In Paris, also, it has been employed on the small scale. 2. Boiling and Agitation. — This plan gets rid of calcium carbonate, iron in part, and hydrogen sulphide, and lessens, it is said, organic matter. It is uncertain if boiling will completely destroy the poisons of the specific diseases, but it is highly probable. It will not destroy completely all bac- teria, or at least their germs still live, and Lex found some bacteria, still moving rapidly, at a temperatui-e of 127° C." T^iidaU's experiments have shown that there are stages in the life of bacteria during which they can resist almost any moist heat. But as they soften before proi:)agation a solution can be successfully sterihzed by repeated boilings, so as to attack the several crops of bacteria in their vulnerable condition. Most fungus spores are killed by boiling. 3. Aluminous Salts. — Alum has been used for centuries in India and China, to purify water from suspended matters. It does this very effec- tually, if there be calcium carbonate in the water ; calcium suliDhate is formed, and this and a bulky aluminium hydrate entangle the floating par- ticles and sink to the bottom. Mr. Alfred Bird has proposed aluminium tersulphate, which is equally efficacious ; it is an acid liquid, containing about .4 grain of the sulphate in each minim ; and M. Bellamy" has also proposed a modification of the alum process, by adding additional potash to a solution of alum till the precipitate is redissolved. The quantity of crystallized alum to be used should be about six grains per gallon ; of Mr. Bird's fluid (sulphate of alumina), twenty drops. From numerous experiments on purification with crystallized alum, and with Mr. Bird's patent liquid, with and without calcium carbonate in the water, it is clear not only that calcium carbonate ought to be in the Avater, but that the action of both alum and Bird's fluid is made more upon the suspended organic matters than upon those actually dissolved ; and, indeed, having regard to the great difficulty of insuring that water is actually free from minute suspended matters, it is even a question whether aluminous salts will act in any appreciable degree on dissolved organic matters. But on suspended matters, both organic and mineral, the effect ' Sanderson puts the death-point of common septic bacteria at about 110" C. or 2C0" F. - Comptes Rendus de I'Acad. , November 11, 1867, p. 799. •WATEE. 31 is very great indeed. Common alum and Bird's liquid seem practically equal ; but alum, being solid, is more convenient for transport. ^ If a sedimentons water is extremely soft, a little calcium cKloride and sodium carbonate should be put in before the alum is added. 4 Addition of Lime Water (Clark's patent). — By combining with car- bonic acid, it causes almost all the calcium carbonate previously and newly formed to be thrown down. It also throws down suspended and a certain proportion of dissolved organic matters, and also, it is said, iron. It does not touch calcium and magnesium sulphate and chloride." 5. Sodium Carbonate, with boiling, throws down lime, and possibly a little lead, if present. 6. Addition of Potassium or Sodium Permanganate (Condy's red fluid). — Pure Condy's fluid readily removes the smell of hydrogen sulphide and the pecuhar offensive odor of impure water which has been kept in casks or tanks. If it forms a precipitate of manganic oxide, it also carries down suspended matters ; but the formation of this precipitate is very uncertain. The action on the dissolved organic matters will, of course, vary with the nature of the substance ; some of the organic matters, both animal and vegetable, will be oxidized ; but in the cold it will not act upon the whole of these substances, and some organic matters are not touched. One objection to the use of the permanganate is that it often communi- cates a yellow tint to the water, arising from suspended finely divided peroxide of manganese. This is probably of no moment as far as health is concerned, but it is unpleasant. Sometimes the addition of a little alum will carry down this suspended matter ; boiling may be used but often has no effect. Sometimes nothing removes it but filtration. The indications for the use of permanganate are these. In the case of any foul-smelling or suspected water, add good Condy's fluid, teaspoonful by teaspoonful, to 3 or 4 gallons of the water, stirring constant^. When the least permanent pink tint is perceptible, stop for five minutes ; if the tint is gone, add 36 drops, and then, if necessary, 30 more, and then allow to stand for sis hours ; then add for each gallon 6 grains of a solution of crystalHzed alum, and if the water is very soft, a httle calcium chloride and sodium car- bonate, and allow to stand for twelve or eighteen hours. There are many cases in which this plan may be useful ; and as the permanganate certainly removes smells and oxidizes in the cold to some extent, it is a very good introduction to the alum process, and does work which alum alone wiU not do. But it cannot be considered a complete purifier of water from all organic matters. Its oxidizing power is, how- ever, often useful in cleaning charcoal filters, as will be presently noted. 7. Perchloride of Iron. — It has been found that the water of the Maas in Holland, which is turbid from clay and finely suspended organic matters, and gives rise in consequence to diarrhoea, is completely purified by per- chloride of iron in the proportion of about 2|- grains of the sohd perchloride to 1 gallon of water. ^ It is a powerful oxidizing agent. Use of the Strychnos potatorum. — In India the fruit of the Strychnos potatorum is used, especially by the better class of Hindoos, to purify water. ' The headquarter wing of the 92d Highlanders, going up the Indus in 1868, suf- fered from diarrhoea from the use of the water ; the left wing used alum, and had no diarrhoea. The right wing then used it, and the diarrhoea disappeared. — Indian Med- ical Gazette, August, 1869, p. 158. '^ This plan has been carried out with great success on a large scale, in the form known as the Porter-Clark process, and also in a modified form by Messrs, Atkins. 3 Chemical News, May, 1869, p. 239. 32 PRACTICAL HYGIENE. It is beaten into a paste, and iiibbed on the inside of the \rater jar or cask. Dr. Mouat says that it is chiefly iised for the river- water at the seasons when it is laden with silt, and that about 30 gi-ains are used for 100 gallons of water, which act in twenty-fom- hours. Its action appeal's to be on sus- pended matters, which it possibly caiiies down b}' giving to the water a delicate albuminous coagiilum, so that it purifies water on the same princi- ple as beer is fined.' Dr. O'Shaughnessy thought its action was connected with its astringency. Some expeiiments on its action were made at Netley, bvit -without any satisfactory result. It did not even clear the water thor- oughly from suspended matters, and it had no effect on the amount of ni- trous acid, ammonia, or of oxidizable organic matters, as far as these could be judged of by potassium pennanganate. Renewed experiments are, how- ever, necessaiy. 8. Immersion of Iron Wire and Magnetic Oxide of Iron (Medlock). — This plan is said to decompose organic matter. Charcoal and ferric oxide ai'e sometimes mixed. 9. Immersion or boiling of certain Vegetables, especially those containing tannin, such as tea," kino, the Laurier rose [Nerium Oleander, which is also rubbed on the inside of casks in Barbary), bitter almonds (in Eg;s'iDt). 10. Charring the inside of Casks. — This is an effectual plan, and Berthol- let considered it more efiectual than the immersion of j^ieces of charcoal ; the charring can be renewed from time to time. To jDut these facts in another form : — Organic matter is got rid of most readily by exposure to air, boiling, agitation, charcoal, alum, potassium pennanganate, astringents. Carbonate of Lime by boiling and addition of caustic hme. Iron, by boiling and lime water, and in pai't by charcoal.^ Calcium and viagnesium sulphate and chloride cannot be got rid of. It should be remembered that some water-plants have a purifying effect, apparently from the large quantity of oxygen they give out ; and this takes place sometimes though the water itself is green. With Filteation. Sand and Gravel. — On the large scale, water is received into settling resei'vou's, where the most bulky substances subside, and is then filtered through gravel and sand, either by descent or ascent, or both.* ' Pereira, Pharmaceutical Journal, vol. ix., p. 478. ^ In the north of China, and especially during winter, the water of the Peiho be- comes very impure, and contains not only suspended matters, but dissolved animal matter in large quantity, which gives the water a disagreeable offensive smell. The Chinese never drink it except as tea, which is cooled with a lump of ice, if it is desired to drink it cold. In this way they secure themselves from all bad effects of this water (Friedel, Das Klima Ost-Asiens, p. CO). The Europeans use ahim and charcoal ; but these do not always entirely remove the taste. The Tartars also use their "brick tea " to purify the water of the steppes, which would otherwise be undrinkable. ^ Chevalier, Traite des Dc-sinfect. , p. 147. In the Ashanti campaign, under the di- rections of Surgeon-Major V. GouJdsbury, C.M.G., the water was purified in the fol- lowing way, in the absence of proper filters: — Alum was added to precipitate suspended matter — the water was passed through a rough filter, consisting of (1) sponge ; (2) sand ; (3j charcoal in pieces ; it was then boiled, and a few drops of solution of potas- sium permanganate added. Water, even taken from a hole in a marsh, was innocuous after this treatment. ■* A good account of the engineering plans and filtration of the London Water Com- panies will be found in a work called The Water Works of London, by Messrs. Col- bum & Shaw, 1867. WATEE. 33 The London "R-ater companies usually employ a depth of 3 to 5 feet ; in the latter case, the upper stratum of 18 inches or 2 feet is composed of sand, the lower 3 feet are made up of gTavel, gradually increasing in coarse- ness, fi-om pieces the size of a small pea and bean to that of a middle-sized potato. A stratrun of oyster shells, about 1^ inch in thickness, has been used by some companies instead of a layer of gravel ; but this plan is not general. If •the filter is 3 feet in thickness, the upper 15 inches ai-e sand, and the lower 21 inches are gravel. The pressure of water in these filters is not great ; the depth of the water is never above 2 feet, and some companies have only 1 foot. From 70 to 75 gallons is th,e usual quantity which should pass through in twenty- four hours for each square foot ; but some companies filter more quickly, viz., at the rate of a gallon per twenty- four houi-s for each square inch, or 144 gallons per square foot. The sand should not be too fine ; the shai-p angular particles are the best. The action seems chiefly, perhaps altogether, mechanical ; the sus- pended impurities, both mineral and organic, rub upon and adhere to the angles and plane surfaces of the sand, which ai-e gradually encnisted, and after a certain time the sand has to be cleaned. The effect on suspended matters, both organic and mineral, is certainly satisfactoiy. On dissolved organic matter it is less so.' j\Ii'. "Witt's experiments show only a removal of aboiit 5 per cent. Some experiments were made at Netley on a sand filter of 1 square foot sui'face, and made in imitation of a London water company's filter, \xz., 15 inches of fine, well-washed white sand, and 20^ inches of gravel, gradually increasing in coarseness. The first eight gallons were thrown away, so as to avoid the faUacy of including the distilled water with which the sand had been washed. This sand filter had some effect in lessening the dissolved constituents, both mineral and organic, but the effect was limited ; it stopj)ed organic matter after it had ceased to arrest hme. After a longer time it became useless, and required washing. It is yet uncertain whether the action of sand on organic matter is at all chemical, i.e., whether the organic matter is oxidized in its transit ; considering what an amount of au' is contained in the interstices of sand, and how finely the water is divided in its transit, some amount of oxidation is probable, but good chemical evidence is yet wanted. Mr. Shield's ex- periments, given in the note, seem opposed to the probabihty of much chemical action. On dissolved mineral matters sand exerts at fu-st, and when in thick layers, a good deal of action ; much sodium chloride can be removed ; and Professor Clark has stated that even lead can be got rid of by filteiing through a thick stratum. Very finely divided clay seems to pass thi'ough more readily than any other suspended matters." ' In a sand and p^ravel filter. 33 inches in thickness, Mr. Shield (Proc. Inst, of Civil Engiuutrs for 18G7) gives the following- numbers : — The original amount of or- ganic matter being .8906 gram per gallon, the amount after filtration was as follows —after 23 hours action, 1.102 ; after 120 hours, .648 ; after 24U hours. .917 ; after 376 hours, .809. So that, while on the whole, the sand removed some organic matter, the amount is really inconsiderable. - A peculiar difficulty, never experienced in England, has been discovered in the fil- tering, through sand, of the Hooghly water at Calcutta ; during the rainy season the fine mud brought down penetrates very deeply into the filters, and rapidly chokes them ; in the dry season this does not happen ; the suspended matters are arrested, as in England, near the upper surface of the sand. Mr. D. Waldie (Journal of the Asi- atic Society of Bengal for 1873, part 11, p. 210) explains this by showing that in the Vol. I.— 3 34 PRACTICAL HYGIENE. Tlie fine white sand is the best ; it should be chosen carefully, and well washed, and, if possible, heated to redness before use. Listead of sand and gravel, trap-rock has been used. Sponge. — Sponge has a considerable effect in mechanically arresting suspended particles, but very Httle on dissolved matters. Animal Charcoal. — Pirre animal charcoal (deprived, as far as possible, of calcium phosphate and carbonate by washiag or by hycb-ochloric acid) used to be considei-ed one of the best filtering materials. The particles of charcoal should be weU pressed together, and the passage of the water should not be too quick. Contact with the water for about four minxites appears sufficient. There is a large (and, if the Layer of charcoal be deep enough, complete) removal of suspended matters, both mineral and organ- ic : water even deeply tinged comes through a good chai'coal filter very clear and bright. So also dissolved organic and mineral matters are re- moved by charcoal in the fii*st instance. All eridence agrees in respect of that point. But then its power is limited, and after a time it ceases to be efficient. Li exj)eriments made with animal charcoal at Netley (by Drs. F. de Chaumont and J. L. Notter) it was found that it had a very rapid and pow- erful effect upon dead or decomi^osing organic matter, but that it allowed fresh organic matter, such as fresh egg albumen, to pass through to a large extent unchanged.' This suggests serious considerations with refer- ence to the effect upon disease poisons. It was also found (as in ]VIi\ Byrne's experiments) that after a time the filtering action not only ceased, but that the charcoal began to give back some of the organic matter it had removed. The same result takes place if the water be left too long in con- tact with the charcoal. Water filtered through charcoal, if it be kept for any length of time, shows some evidence of low fonns of organic life — in some instances a copious deposit forming. This may be due either to spores or germs passing through unchanged," or to the phosphates yielded by the charcoal affording a favorable nutrient for germs absorbed from the atmosphere. For these reasons it seems unadrisable to use charcoal for filtration on a large scale, independent of the consideration of exj^ense. The plan of placing charcoal filters in Avater cisterns, now often practised, ought also to be given up. The conclusions to be aiTived at with regard to charcoal as a filtering medium are these : — (1) It acts both chemically and mechanically, and is at first both raj^id and efficient. (2) With a good bulk of material, water may be passed through nearly as rapidly as it can flow and be well purified. (3) Water must not be left in contact with the charcoal longer than is necessary for filtration, as it is apt to take up organ- ic matter again. (4) Water filtered through charcoal must not be stored for any time, but must be used immediately, as if kept it is apt to become rainy season the water contains much less saline matter than in the dry season ; it is this saline matter which seems to act on and so cause colierence of the particles of mud, so that they become larger and coarser, and are moi-e easily arrested. In order to remedy this, Mr. Waldie proposes the addition of substances to the water during the rains, which may cause this coalescence ; he has tried a great number of experiments and different substances, on the whole crystallized alum and perchlonde of iron are the best ; ■').'5.4 tti. of crystallized alum, or 1!). 15 IT>. of perchloi'ide of iron, were found to be necessary for the clariiication of one million gallons of muddy Hooghly water durins: the rainy season. ' See Sanitary Record, Oct , 1876, p. 288, and A. M. D. Reports, vol. xix , p. 170. '-' This ajipears the more probable. Minute diatoms were found in water which had been kept for some months that had passed through Crease's large filter tanks at Parkhurst. WATER. 35 charged with minute living organisms. (5) Since fresh organic matter may pass through it unchanged, animal charcoal cannot be conhdentty depended upon to piuify water from disease poisons. (6) The power of charcoal is limited ; with a moderately good water it remains efS.cient for some time, but with an impure water it soon becomes inactive. In most cases it ought to be cleaned or renewed every thi-ee months. Vegetable Charcoal — Peat Charcoal — Seaweed Charcoal. — The first is much less efficacious than animal charcoal — even useless according to I'rankland. The others are rather more effectual, but do not appear to be very power- ful ; they should only be used when animal charcoal cannot be obtained. Spongy Iron. — This substance, obtained by roasting haematite ii'on ore, is porous metallic hon, and not unlilce animal charcoal in apj)eai'ance. It occupies a space of about twenty cubic teet to the ton. Its action on water is both mechanical and chemical, for it arrests suspended matter and also oxidizes organic matter in solution. It acts upon water itself, decom- posing it and setting free hydi'ogen — the oxygen being afterward given up to organic matter that may come in contact with it. Its oxidizing power is very great, although perhaps a Httle slow. Eipeiimeuts at Net- ley ' showed that it could be depended ujDon to remove the gTeater part of the dissolved organic matter, and with prolonged exjDosui'e the whole of it in many instances. It has not much effect on mineral matter, but removes lead. It fields a httle hon to the watei', which, however, can be removed by fui'ther filtration thi-oiigh prepared sand — that is, sand or fine gi-avel with pyi'olusite. Beyond this nothing is yielded to the water, which comes out quite clear and pure, and may be stored for a long time without under- going any change or showing signs of the production of h-ving organisms — or in any way favoring putrefaction." Water left in contact with it does not deteriorate. It retains its filtering power a long time, very much longer than animal charcoal. Those properties render it suitable for use on a large scale, and it has been so used in several j)laces ; as, for examjDle, in the Water Works of Antwerp. On the whole, it must be looked upon as one of the most powerful and lasting filtering media we have. Carferal. — This substance has been introduced within the last two or three years. It is a black granular matter, bearing an external resemblance to granular animal charcoal. Its specific gTarit}' is 2.879, and its bidk in its usual condition is about 25 cubic feet to the ton. Its method of manu- factui'e and composition have not as yet been made known, so far as can be ascertained — but it consists of a mixture of charcoal and u'on in small quantities with a basis of clay. ^ It has very considerable puiif^ing powers, and acts very rapidly, even upon fresh albumin, yielding nothing deleteri- ous to the water, which may be stored for a time without the production of any organisms. Its lasting powers appear to be slightly better than those of the animal charcoal, although inferior to those of spongj: hon.^ There is, however, the objection that it appears to have no definite compo- sition. It is also probable that there is more than one sort in the market, or that the material is adulterated from time to time, a thing difficult to detect when the original composition is uncertain. Domestic Filters. — On a small scale, a number of substances have been ' A M D. Reports, vol. xx., p. 205 et seq. - See M. Gust.avBischof, " Oa Putrescenc Organic Matter in Potable Water," Proc. Royal See, Xo. 80, 1S77 ; also " Sanitary Notes on Potable Water," Sanitary Rec- ord, vol. X., p. 337 ^ Hence the name " Carferal," from the first syllables of CV/rbon, /e?Tam, and al- nmina. ^ See A.M.D. Reports, vol. xx., p. 205 et seq., and vol. xxi., p. 228. 36 PRACTICAL HYGIENE. used, such as animal and vegetable charcoal, in granules or powder, or made into blocks, or fine silica impregnated with charcoal (silicated carbon filters), haematite and magnetic iron ores, the so-called magnetic carbide, spongy iron, manganic oxide, flannel, wool, sponges, porous sandstones (natural and artificial), etc. The Souchon filters, which are much employed in Paris, are made of diaphragms of wool, which is jDartially tanned by boiling in solution of alum and cream of tartar, then dyeing in infusion of gall-nuts, and wash- ing in solution of sodium carbonate. The filter of ~SL Fonvielle, also used in Paris, is composed of nine layers of sponges, pounded sandstone, and gravel. The " Filtre Ri^pide " of Maignen is an ingenious an-angement, by which a large straining surface is presented to the water by the spreading of asbestos cloth over a fi-ame, or over a perforated cone of porcelain. Any filtering medium in powder or granules may be mixed with the water and settles on the cloth ; this, of course, can be renewed as required. The " Filtre Chanoit " is much used in Fi-ance. The straining mate- rial is ground slag (" Scoi'ie de fonte "), and the filter requires to be used under j^ressure (5 centimeters) ; by this means a cushion of air is com- pressed, and acts as a pxu-ifier. The filters in the market in this countiw are very numerous, but the most imjiortant are the following : — 1. Those containing animal charcoal, in granules or powder. 2. Animal charcoal compressed into blocks by admixtui-e with siUca and other substances. 3. Spongy iron filters. 4 Those containing cai'feral and other substances of a nature chiefly mineral. The essentials of a good filter are the following : — 1. That eveiy part of the filter shall be easily got at, for the purposes of cleaning, or of renewing the medium. 2. That the medium have a suificiently purifying power, and be i^res- ent in sufiicient quantity. 3. That the medium yield nothing to the water that may favor the growth of low forms of life. 4. That the purifying power be reasonably lasting. 5. That there shall be nothing in the construction of the filter itself that shall be caj)able of undergoing putrefaction, or of peldmg metaUic or other impurities to the water. 6. That the filtering material shall not be able to clog, and that the de- livery of the water shall be reasonably rapid. The fii'st of these conditions obviously sets aside all filters of the older, and what used to be the usual, pattern, where only a small layer of filter- ing material was present, which was cemented up so as not to be reached without breaking open the aj)paratus. The second condition is fulfilled, so far as filtei-ing power is concerned, ])y a number of media ; with regard to bulk of material this is also faii'ly well attended to in the filters when loose material is used — but where sohd blocks are employed the size is often quite incommensurate with the work they are called upon to do. The third condition is comphed with by spongy u*on, good samples of carferal, and some other materials — but (as before mentioned) not by WATEE. 37 animal charcoal in the loose condition. As solid, blocks, it seems to yield less to water than in the gTanular condition. The fourth condition depends a good deal upon the relative degxee of impiu'ity of the water. The siDongy ii'on on the whole lasts the longest. The Jifth condition demands that nothing organic shall be used in the construction of the filter, or in the packing of the interior.' Iron or other metal must be protected from the action of the water." The sixth condition is generally fulfilled when the material is loose and when the water is not too full of suspended matter. Sometimes sponge is used to arrest suspended matter, but it is so apt to get foul that its use had better be avoided. The block filters are very apt to clog, a slimy sub- stance forming on their sm-face. This is partly obviated now by the use of asbestos strainers (as in the silicated carbon filter). Spongy iron is apt to cake unless kept constantly covered with water, but this is arranged for in the new forms of filter. As regards rapidity of delivery, the animal charcoal and the cai'feral (when the sample is really good) have the advan- tage over spongy iron and block filters — in the following ratio : — 1. Animal Charcoal, j Water runs through fairly weU pui-ified in 2. Carferal, ( 2^ to 4 minutes. 3. Sihcated Carbon, Average exposure, 15 minutes. 4. Spongy Ii'on,' " " 22 It is obvious that, for reasons of convenience, one filter may be prefer- able to the others according to circumstances. If the Avater is requhed immediately in considerable quantity, and is to be consumed at once, either animal charcoal or carferal would be used. In the other cases, where the delivery is slower, the size or the number of the filters would have to be arranged accordingly. Cleansing of Filters. — All filters when first taken into use reqmre to be washed by passing from ten to twenty gallons of fairly good water through them, according to the size of the filtei', as the filtering medium generally yields something to water hi the beginning. It is also necessary to ensm-e the removal of dust, etc., that may be in the ajDparatus. But after a cer- tain time of use ah filtering media not only cease to be efiicient, but even in some instances give up impui-ity to the water passed tln-ough them ; so much is this the fact that cases of illness have been traced to this soui'ce, and some persons have thought the dangers of filtration were gi-eater than those of unfiltered water. There is no doubt that the practice of depend- ing for years upon the efiiciency of a filter, which has never been cleaned or had its material renewed, is fraught with danger, and there is still danger to be apprehended from many of the so-called " self -cleaning " filters which, in the words of the adveriisement, " reqmre no attention." There is a hmit to the power of aU filteiing materials, and no imphcit con- fidence can be placed in any of the methods vaunted as " self -cleaning." It is not possible to state positively the length of time any filtering material wUl remain efiicient, so much dependmg upon the condition of the water and the quantity passed through. Animal charcoal in granules or powder ought to be examined at least every thi'ee months. If water ^ Cotton has sometimes been used and gone rapidly to decay. ^ Water has been found strongly charged with zinc, from the use of so-called gal- vanized iron in filters. ^ Water can be dra-ivn off much more rapidly from this filter, if required, but this is not recommended by the inventor. 38 PRACTICAL HYGIENE. passed throuf^h it can be chemically and microscopically analyzed and is found juu'e, the charcoal may be continued in use — but in the absence of such assurance it will be safer to take stejDs for cleanmg- it. The best plan of all is to heat it to redness luider cover, and then wash it with distilled water or the cleanest that can be prociu-ed. Failing- this, boiling it, with or without peiToauganate of potassium solution or dilute Condy's tiuid and a little mineral acid, is the safest plan. After this it may be exposed to the au* and sun, thoroughly washed, and then \ised agam. The perman- ganate solution (or Condy's fluid) should be passed thi'ough it luitil it comes out a distinct pink color. Carferal may be treated in much the same way as charcoal, Avitli the omission of the permanganate solution ; but it must be remembered that in both cases the diu-ation of efficiency dej^ends gTeatly upon the bulk of the material with reference to the quantity of water passed thi-ough it. Spongy iron retains its efficiency for a long tune, and, as in the filters made ^ith it the flow of water is expressly hmited with reference to the bulk of material, the diflerence is solely in relation to the greater or less impiu'ity of the water acted upon. Its efficiency may genei'ally be de- pended upon for a year, and unless the water be very impiu-e, even for a considerably longer tune. So long as the water filtered through it appears chemically and microscojiically pure, the filti-ation may be canied on with confidence. "When the hmit of efficiency is reached, the only safe plan is to renew the charge of material, and it is genei-ally advisable to i)ro\ide for this renewal once a year ; should circumstances arise, however, to prevent this renewal, the best plan for cleaning is to subject all the material to the action of fire, up to a low red heat, then to wash the whole well, and return it into the filter. The cleansing with permanganate and acid must not be attempted. Filters, where the material is cemented up and cannot be removed, ought to be abandoned altogether. Strainers of sponge, or any material which cannot stand the action of fii'e, ought also to be given up. Asbestos forms an excellent stramer, and can be heated to redness, so as to destroy all organic matter, as often as re- quii'ed. Block Filters are generally vmdesirable forms ; but if used, they may be cleansed by carefully brushing the surface, pumping ail* in the revei-se way, and treating- with pennanganate as above described. They are of various sizes, from small pocket filters to large-sized domestic filters deUvering thirty to fifty gallons a day. The pocket filters are nsefid as sti-ainers, but their small size must make the diu-ation of then- oxidizing power very short. They ought to be frequently bnished and washed in clean water, with per- manganate if possible. Cistern and Pipe Filters. — Filters are sometimes placed in cisterns, behig constantly immersed in the water to be filtered. This is an objec- tionable plan, and ought to be abandoned. PijDe filters are those which are placed in the course of a supply pipe, and tap-filters those which are fitted on to a deHvery tap. The objection to most of those filters is that they are generally much too small for the work expected from them, as they are usually represented by a small cylinder of block carbon or a few ounces of animal charcoal. For proper filtration the only way is to have a full-sized filter attached to the supply pipe, with a ball-cock or similar ap- paratus for filling it.' The object is of coui-se twofold— first, to ensure 'See Fig. 11, p. 110. WATEE. 39 that all the water drawn shall be filtered, and, second, to save the time re- quired when the filter has to be filled by hand. Service Filters for Land and Sea. — Lieut. -Col. Crease, C.B., Royal Marine Artillery, has arranged some excellent forms of filters, both small for barrack, hospital, or ambulance use, and large tanks for shij)s, or for large bodies of men on shore. The principle of them all is a filter of strong durable material, which yields nothing to water, space for a large quantity of filtering material, and a rapid dehvery. The small filters may be earth- enware or iron, the latter being protected internally by a patent cement ; the larger tanks are of iron, protected in the same way. The material originally used was sand and animal charcoal in separate compartments. This answered very well, and was re|)orted uj)on very favorably by Sur- geon-General Sir A. D. Home, KC.B., V.C, in the Ashanti War.' Carferal is now emjDloyed, so that the whole bulk is active filtering material. By using a large quantity of the material with a rapid dehvery, a storage reservoir becomes unnecessary. The delivery can be regulated by screwing down or loosening a plate in the filter, so as to compress the material, or slacken the pressiu'e as requii'ed. SECTION IV. EFFECTS OF AN IXSUFFICIENT OR IMPURE SUPPLY OF WATER. Sub-Section I. — Insufficient Supply. The consequences either of a short supply of water for domestic pur- poses, or of difficvilty in removing water which has been used, are very- similar. On this point much valuable information' was collected by the Health of Towns Commission in their invaluable Reports.'' It was then shown that want of water leads to impurities of all kinds ; the person and clothes are not washed, or are washed repeatedly in the same water ; cook- ing water is used scantily, or more than once ; habitations become dirty, streets are not cleaned, sewers become clogged ; and in these various ways a want of water jproduces uncleanliness of the very air itself. The result of such a state of things is a general lowered state of health among the population ; it has been thought also that some skin diseases — scabies, and the epiphytic affections especially — and ophthalmia in some cases, are thus i^ropagated. It also appears likely that the remarkable cessation of spotted typhus among the civilized and cleanly nations is in part owing, not merely to better ventilation, but to more frequent and thorough washing of clothes. The deficiency of water leading to insufficient cleansing of sewers has a great effect on the spread of typhoid and of choleraic diarrhoea ; and cases have been known in which outbreaks of the latter disease have been arrest- ed by a heavy fall of rain. Little is known with certainty of the effects produced on men by de- ficiency in the supply of water. Under ordinary circumstances, the sensa- tion of thirst, the most delicate and imperative of all our feelings, never permits any great deficiency for a long time, and the water-removing I A. M. D. Reports, vol. xv., p. 247. ^ First and Second Reports (with evidence) of the Health of Towns Commission,. 1844 and 1845. 40 PRACTICAL HYGIENE. organs eliminate Avitli wonderful rapidity any excess that may be taken, so as to keep the amount in the body within certain limits. But when cir- cumstances prevent the supply of water, it is well known that the wish to di'ink becomes so great, that men will run any danger, or undergo any pain, in order to satisfy it. The exact bodily condition thus produced is not precisely laiown, but from experiments on animals and men, it would appear that a lessened amount of water in the body diminishes ' the ehm- ination of the pulmonary carbonic acid, the intestinal excreta, and all the important urinary excreta. The more ob^dous eifects produced on men who are deprived for some time of water- is, besides the feehng of the most painful thii-st, a great lowering of muscular strength and mental vigor. After a time exertion becomes almost impossible, and it is wonderful to see what an extraordinaiy change is produced in an amazingly short time if water can be then jDro- cured. The supply of water becomes, then, a matter of the most urgent necessity when men are undergoing great muscular efforts, and it is veiy important that the sujoply should be by small quantities of water being frequently taken, and not by a large amoimt at any one time. The restric- tion of water by trainers is based on a misapprehension : a little water, and often, should be the rule. Sub-Section II. — Impure Supply. At present, owing probably to the difficulty of making analyses of waters, the exact connection between impure water and disease does not stand on so precise an experimental basis as might be wished. There are some persons who have denied that even considerable organic or mineral impurity can be j^roved to produce any bad effect ; while others have beheved that some mineral ingredients, such as calcium carbonate, are useful It may be true that water containing a large quantity' of organic matter, or much calcium and magnesium sulphate, has been used for long periods without any ill effects. The water of the Canal de I'Ourcq, which contains much calcium bicarbonate and some calcium and magnesium sulphate, was found by Pai'ent-Duchatelet to produce no bad effect, and Boudet more recently asserted the same thing. ^ In some of these cases, however, very Uttle careful inquiry has been made into the state of health of those using the water, and that most fal- lacious of all evidence, a general impression, without a careful collection of facts, has often been the only ground on which the ojjinion has been come to. As weU obsen^ed by Mr. Simon, in one of his philosophical Eej^orts,^ we cannot expect to find the effect of impure water always sudden and violent ; its results are indeed often gradual, and may elude ordinary observation, yet be not the less real and appreciable by a close inquiry. In fact, it is only when striking and violent effects are produced that public attention is ai-rested ; the minor and more insidious, but not less certain, evils are borne with the indifference and apathy of custom. In some cases it is by no means improbable that the use of the impiu'e water, which is supposed ' The experiments of Falck and Scheffer on animals, and of Hosier on men and women, are here referred to. - The Canal de I'Ourcq (which has a boat population of about 40,000) is now aban- doned as a source or drinking water, and the greater part of Paris is supplied from the rivers Vanne and Seine. ^ Second Annual Report to the City of London, p. 121. WATEE. , 41 to be innocuous, lias been really restricted, or that experience lias shown the necessity of purification in some way. This much seems to be certain, that as precise investigations proceed, and, indeed, in proportion to the care of the inquiiy and the accuracy of the examination, a continually in- creasing class of cases is found to be connected with the use of impure water, and it seems only reasonable to infer that a still more rigid inquiiy will fui'ther prove the fi'equency and imjDortance of this mode of origin of some diseases. Animal organic matter, especially when of fsecal origin ; vegetable or- ganic matter, when derived from marshes ; and some salts and metals are the principal noxious ingredients. Of the hui-tful substances the sus^Dended animal, and especially fsecal matters, are probably the worst. At least, it is remarkable how frequently, both in outbreaks of diarrhoea and t_)q3hoid fever, the reports notice tur- bidity, discoloration, and smell of the water. It is this fact which makes the examination of color and tui'bidity important. The thoroughly dis- solved organic matters appear less hui-tful ; at least there is some evidence that perfectly clear waters, though containing much matter dissipated by heat, and consisting of dissolved organic matter or its derivatives, are often taken without injury. Probably, also, the rxpre recent the fsscal contam- ination, the more injuiious, since the most' poisonous attacks on record have been in cases of wells into which, after slow percolation for some time, a sudden gush of sewage water has taken place. It has been frequently stated that the readily oxidizable organic matters in water are the most dangerous. This opinion has probably arisen from the idea that a substance in rapid chemical change is more likely to excite some corresiDonding and hurtful action in the body ; and it ma}^ be true, but there is no existing evidence which can be trusted on the point. There is, on the other hand, some evidence that animal matters forming fatty acids give rise to salts which, though not oxidizing into nitrous and nitric acid, are as hurtful as the more oxidizable substances. Of late years, too, an opinion has been expressed that the amount of the mineral substances is of little consequence. This can be true only in a Hmited sense ; there are some mineral substances, such as sodium chlo- ride or carbonate, or calcium carbonate, which, Tvithin certain limits, ap- pear to do no harm. But in the case of other minerals, such as calcium and magnesium sulphates and chlorides, and calcium nitrate, there can be little doubt that their use is injurious to many persons. It seems also probable ' that a combination of impiuities, and especially the coexistence of organic matter and calcium sulphate, is hurtful ; at least the analysis of waters which have decidedly produced injury often shows that the impuri- ties have been numerous. As far as at present known, the existence of infusoria of different kinds is not hurtful, though they may indicate by their abundance the presence of organic impurity. The eifect of microzymes, algce, or fungi, in drink- ing water is also a matter of which little or nothing is known, though it is very probable that future research may bring out something important in this du'ection. The most practical way of stating the facts connected with the produc- tion of disease by water mil be to enumerate the diseases which have been traced to the use of impure water, and to state the nature of the impurities. 42 PRACTICAL HYGIENE. 1. AFFECTIOXS OF THE ALIMENT.iRT 3IUC0US MEMBEAXE. It is reasonable to suppose that tlie impurities of water would be likely to produce their greatest effect upon the membrane with which they come first in contact. This is in fact found to be the case. Affections of the Stomach — Dyqyejysia. Symptoms which may be refen-ed to the convenient term dyspepsia, and which consist in some loss of appetite, vague uneasiness or actual pain at the ejngastrium, and slight nausea and constipation, with occasional diarrhoea, are caused by water containing a large quantity of calcium sul- phate and chloride, and the magnesian salts. Dr. Sutherland found the hard water of the red sandstone rocks, which was formerly much used in Liverjiool, to have a decided effect in producing constipation, lessening the secretions, and causing visceral obstructions ; and in Glasgow, the sub- stitution of soft for hard water lessened, according to Dr. Leech, the prevalence of dyspeptic complaints. It is a well-known fact that grooms object to give hard water to their horses, on the gi'ound that it makes the coat staring and rough — a ftsult which has been attributed to some de- rangement of digestion. The exact amount which will produce these symptoms has not been determined, but water containing more than 8 grains of each substance indi\-idually or collectiveh' appears to be injurious to many persons. This would correspond to about 10 degrees of perma- nent hardness. A much less degree than this will affect some persons. In a well water at Chatham, which was found to disagi-ee with so many pei'- sons that no one would use the water, the main ingi-edients were 19 grains of carbonate of hme, 11 grains of calcium sulphate, and 13 grains of sodium chloride per gallon. The total solids were 50 grains per gallon. In an- other case of the same kind, the total solids were 58 grains per gallon, the calcium carbonate was 22, the calcium sulj^hate 11, and the sodium chlo- ride 14 grains per gallon. Ii-on, in quantities sufficient to give a slight chalybeate taste, often pro- duces shght dyspepsia, constipation, headache, and general malaise. Cus- tom sometimes partly removes these effects. Dia7'rhoea. Many conditions produce diarrhoea. (a) Suspended Mineral Substances. — Clay, Marl — as in the cases of the water of the Maas, the Mississippi, the Missouri, Eio Grande, Kansas,' of the Ganges, and many other rivers — will at certain times of the year pro- duce diarrhcea, especially in persons unaccustomed to the water. The hiU diarrhoea at Dhurmsala is produced, apparently, by suspended very fine scales of mica.^ (b) Suspended Animal, and especially Fcecal 3Iatlers, have jjroduced diarrhoea in many cases ; such water always contains dissolved organic mattei-s, to which the effect may be partly owing. The case of Croydon in 1854 (Carpenter) is one of the most striking on record. Li cases in which the water is largely contaminated with suspended sewage, it is im- ' Hammond's Hygiene, p. 218. - Whitwell, vide Dr. Macnamara's 8th Report on Potable Waters in Bengal, Appen- dix, p. 44. WATER. 43 portant to observe that the symptoms are often markedly choleraic (purg- ing, vomiting, cramps, and even some loss of heat). This point has been again noticed by Oldekop of Astrachan, ' who found marked choleraic symp- toms to be produced by the water of the Volga, which is impregnated with sewage. Seven cases in one house of violent gastro-intestinal derange- ment (vomiting, diarrhoea, coHe, and fever), produced by water contami- nated by sewage which had passed into the cistern, are recorded by Dr. Gibb." In the prison at Halle an outbreak of dian-hcea was traced by Dolbruck to the contamination of water with putrid substances. In St. Petersburg the water of the Xeva, which is rich in organic substances, give diarrhoea to strangers.'' Suspended" animal and vegetable substances, washed off the gi'ound by heavy rain into shallow wells, have often produced diaiThoea, as at Prague in 1860, when an endemic of " cataiTh of the alimentaiy canal" was caused by heavy floods washing impurities into wells. ^ (c) Su-^'pended Vegetable Substances. — In this country, and also in the late American civil war, several instances have occurred of diarrhoea aris- ing from the use of surface and ditch water, which ceased when wells were sunk ; possibly there might be also animal contamination. It is not, there- fore, cpiite certain that suspended vegetable matter was the vera causa. Surgeon-Major Gore has recorded a violent outbreak of dian-hcea at Bulama, on the west coast of Africa, ° produced by the water of a well; the water was itself pui'e, but was milky from suspended mattei*s, consisting of debris of plants, chlorojohyll, minute cellular and branched algce, monads, polygastrica. and minute pai'ticles of sand and clay. "^Tien filtered the water was C[uite hai-mless. {d) Dissolved Animal Organic Matter.- — The opinion is veiy -widely dif- fused that dissolved and putrescent animal organic matter, to the amount of 3 to 10 grains per gallon, may produce diarrhoea. This is possibly cor- rect, but two points must be conceded — 1st, That there are usually other impuilties which aid the action of the organic matter ; and 2d, That or- ganic matter, even to the amount of 10 to 15 grains per gallon, may exist without bad eftects, if it be perfectly dissolved. In the latter case the water is, however, always clear and sj^arkhng, never tainted or discolored. The fi*equent presence of other impurities renders it difficult to assign its exact influence to dissolved oi'ganic matters. In the case of a well-ventilated coui't in Coventry," where diaiThoea was constantly present, the water contained 5.68 grains per gallon of volatile and combustible matter, but then it contained also no less than 105 gi-ains of fixed salts, which, as the water had a permanent haixlness of 51.6^ (Clai-k's scale) after boiling, must have consisted of calcium and magnesium sulphates and chlorides. It also contained alkaline salts, nitrates, and am- monia. The composition was therefore so complex, that it is diflicult to assign to the organic matter its share in the eifects. The animal organic matter derived from graveyards appears to be es- pecially hiu'tful ; here also ammoniimi and calcium nitrites and nitrates may be present. (e) Dissolved Vegetable Matter. — There is some evidence to show that ^ Virchow's Archiv, baud xxvi., p. 117. ^ British :Medical Journal, Oct., 1870. ^ Ilisch, quoted by Roth and Lex, Mil. -G-esundheitspfl. , p. 24. * Canstatt's Jahresb , 1863, vol. ii.. p. 31. ^ Report on Hygiene by Dr. Parkes, Army Medical Report, vol. v.. p. 428. « Greenhow, Second Report of the Medical Officer of the Privy Council, ISBO, p. 75. 44 PRACTICAL HYGIENE. this produces diarrhoea. Wanklyn cites the case of the Leek workhouse and also that of Biddulph Moor, iu both of which vegetable matter in solu- tion appeared to pi'oduce diarrhoea. (/) Fetid Gams. — Water containing much hydrogen sulphide will give rise to diarrhoea, especially if organic matter be also present. In the Mexican War (1861-G2), the French troops suffered at Orizaba from a peculiar dyspepsia and dian-hoea, attended with immense disengagement of gas and enormous eructations after meals. The eructed gas had a strong smeU of hydrogen sulphide. ' This was traced to the use of water from sulphurous and alkaline springs ; even the best waters of Orizaba contained organic matter and ammonia in some quantity. The exjDeriments of Pro- fessor Weber have shown what marked effects are produced by the injec- tion of hydrogen sulphide in solution in water into the blood ; is it possible that water containing animal organic matter may occasionally form SH,j after absorption into the blood, and that the poisonous effect of some water may be owing to this ? The symptoms of poisoning by water contaminated by sewage are sometimes very like those noted by Weber in his experi- ments, viz., diarrhoea and even choleraic symptoms (lowering of tempera- ture), and irritation of the lungs, spine, hver, and kidneys. The absorption of sewer gases, as when the overflow-pipe of a cistern opens into the sewei's, will cause diarrhoea. This seems perfectly proved by the case recorded by Dr. Greenhow, in Mr. Simon's second report.' {g) Dissolved Mineral Matters, if passing a certain point, produce diarrhoea. Boudin refers to an outbreak of diarrhoea at Oran, in Algiers, which was distinctly traced to bad water, and ceased on the cavise being removed ; the composition of the water is not explicitly given, but it con- tained lime, magnesia, and carbonate of soda. Sulphates of lime and magnesia also cause diarrhoea, following sometimes constiiDation. The selenitic well waters of Paris used to have this effect on strangers. Parent- Duchcitelet ' noticed the constant excess of patients furnished by the prison of St. Lazare, in consequence of diarrhoea, and he traced this to the water, which " contained a very large proportion of sulj^hate of lime and other purgative salts ; " and he tells us that Pinel had noticed the same fact twenty years before in a particular section of the Salpetriere. In some of the West Indian stations, the water drawn from the calcareous formation has been long abandoned, in consequence of the tendency to diarrhoea which it caused. Calcium nitrate waters also produce diarrhoea. A case is on record, in which a well water was obliged to be disused, in consequence of its impreg- nation with butyrate of calcium (105 grains per gallon), which was derived from a trench filled with decomposing animal and vegetable matters.' Brackish water (whether rendered so by the sea, or derived from loose sands) produces diarrhoea in a large percentage of persons, and at some of the Cape frontier stations water of this character formerly caused much disease of this kind. In a water examined at Netley, which became brack- ish from sea water, and which produced diarrhoea in almost all persons, ' Poncet, in Rec. de Mem. de Med. Mil., 1868, p. 218. The exact words are " une odeur d'acid sulfurique," but " sulfhydrique " must be meant. ^ Second Report of the Medical Officer of the Privy Council, Pari. Paper, 1860, p. 153. ' Hygiene Publique, t. i., p. 286. •* Zeitschriffc fur Hygiene, vol. i.. p. 166. See also a remark on the effect of calcium and potassium iiitiate in causing a tendency to diarrhoea in the Report on the Drain- age of Berlin (Die Kanalisation von Berlin, 1868, pp. 27, 28). WATER. 45 tlie amount of cliloricle of sodium was found to be 253 grains per gallon. But, douljtless, a much less quantity tlian this, especially if chloride of magnesium be present, ^iU act in this way. (h) MetoJlic Impregna.tion. — Occasionally animal organic matter acts in an indirect way, by producing nitrites and nitrates, which act on metals. Dr. Baedeker,^ a j^hysician in "Witten, was called to some cases of sick- ness produced apparently by water. On examining the point, he forma the water was drawn from a pump with a copper cylinder, and contained a considerable quantity of copper, which seemed to be in combination with some organic matter." Lead (as might have been anticipated) was also largely present in this water, as leaden pumps were used ; iron, on the contrai-y, was not dissolved. Dysentery. Dysentery also is decidedly produced by impure water, and this cause ranks high in the etiology of dysenteiy, though perhaps it is not the first. Several of the older amiy-siu-geons refer to this cause. Pringle does so several times, and also Donald Munro.^ In the "West Indies, Lemj)riere,^ in 1799, noticed the increase of bowel complaints in Jamaica in May, when, after floods, the water was bad and turbid, " and loaded with dirt and filth." He also mentions, that at Kin gston and Port Eoyal the dysenteiy was owing to brackish watei\ It was not, however, for many years after this that fresh soui'ces of water were sought for in the West Indies, and that rain- water began to be used when good spring or river water could not be got. Davis ^ mentions as a curious fact, in reference to the West Indies, that ships' crews, when ordered to Tortola, were "invariably seized with fluxes," which were caused by the water. But the inhabitants who used tank (i.e., rain) water were fi'ee ; and so well knovra. was this, that when any resident at Tortola was invited to dinner on board a man-of-wai', it was no unusual thing for him to carry his drinking water T\ith him. The dysenteiw at Walcheren, in 1809, was in no small degree owing to the bad water, which was almost everr^'here brackish. The epidemic at Guadaloupe, in 1847, recorded by Comuel, seems also quite conclusive as to the effect of impui'e water in causing not merely isolated cases, but a wide-spread outbreak." In 1860, at Prague, there were many cases of dysenteiy, clearly traced to the use of water of wells and spiings rendered foul by substances washed into the water by heavy floods. Exact analyses were not made. On the west Coast of Africa (CajDe Coast Castle), an attack of dysenteiy was traced by Surgeon-Major Oakes to the passage of sewage from a cess- pool into one of the tanks. " This was remedied, and the result was the almost total disappearance of the disease." ^ Pappenheim's Beitrage, heft iv. , p. 49. ^ The amount of copper required to produce poisonous symptoms appears to be doubtful. It is said that the miners in the desert of Attacama, in South America, prefer to use water containing so much copper as to have a distinct green color, rather than the ^Yater brought up from the wells near the shore in skins, which give it an unpleasant taste. It is true that it is used for making coffee, and may thus be to a certain esteit purified. ^ Campaigns in Flanders and Germany. 4 Vol i., p. 25. * On the Walcheren Fever, p. 10. ® See a review by the late Dr. Parkes on Dysentery, in the British and Foreign Medical and Chirurgical Review for 1847, for fuller details of this epidemic. 46 PRACTICAL HYGIENE. That in the East Indies a great deal of dysentery lias been produced by impure water, is a matter too familiar almost to be mentioned (Annesley ; Twining). Its constant prevalence at Secunderabad, in the Deccan, appears to have been pai-tiy owing to the water which jjercolated through a large gi-aveyard. One bf the sources of water contained 119 gi-ains of solids per gallon, and in some instances there were 8, 11, and even 30 grains per gal- lon of organic matter.' Champouillon " has recorded a case in which two regiments used the impure water from the Canal de TOui-cq, neai* Paris. One regiment mixed the water with coffee or red wine, the tannin of wliich united with the or- ganic matter ; this regiment had no dysentery. The second regiment used brandy, which precipitated the organic matter on the side of the vessel, where' it putretiecL This regiment suffered from dysenteiy ; the substi- tution of red wine for brandy stopped the disease. The gi-eat effect produced by the impure water of Calcutta in this way has been pointed out by Che vers. ^ In time of war this cause has often been present ; and the gi'eat loss by dysenteiy in the Peninsula, at Ciudad Eodi-igo, was partly attributed by Su- J. M'Grigor to the use of water passing through a cemetery where nearly 20,000 bodies had been hastily inteiTcd. The impurities which thus produce dysentery appear to be of the same kind as those which cause the allied condition, dian-hoea. Suspended earthy matters, suspended animal organic matter, calcium and magnesium sulphates and chlorides, calcium and ammonium nitrates, large quantities of sodium and magnesium chlorides in solution, appear to be the usual ingi-edients ; but there are few perfect analyses yet known. ^ The obseiTations which j^rove so satisfactorily that the dysenteric stools can propagate the disease, make it j)robable that, as in the case of t^-phoid fever and cholera, the accidental joassage of dysenteric evacuations into drinking water may have some share in spreading the diseasa 2. AFFECTION OF OTHER MUCOUS MEMBR.VKES BESIDES THE ALIMENTARY. Little has yet been done to trace out this point. At Prague, after the severe flood of 18G0, bronchial catarrh was frecjuent, jirobably caused chiefly by the chills arising from the gi-eat evaporation ; but it was noticed that bronchial catarrh was most common when the chinking water was foulest and produced dysentery. Possibly the bronchial and the urinary mucous membranes may also suffer from foul water ; the point is well worthy of close investigation. 3. SPECIFIC DISEASES. That some of the specific diseases are disseminated by drinking water is a fact which has only attracted its due share of attention of late years. It is certainly one of the most imj)ortant stej^s in etiolog}^ which has been ' Indian Report, p. 44. 2 Rec. de Mem. de Med. Mil. 1873. Sept., p. 230. ^ndiau Annals. No. 17, p. 70. 18(34. * A loc.ilized epidemic of dysenteiy occurred in some barracks at Niirtberg in the summer of 1S72. oO caseg and 4 deaths taking place among the soldiers. The absorp- tion of putrefaction ga.ses from the cloaca in the wings of the building by the drinking water, was considered to be the cause ; the water couiained nitrates and free am- monia. An individual predisposition to the disease appeared, however, to be also necessary. (Schmidt's Jahrbiicher, 1874, vol. i., p. 25.) TTATER, 47 made in this centiny, and the chief merit of its discovery is due to the late Dr. Snow. JIalarious Fex:ers. Hippocrates states that the spleens of those who diink the water of marshes become enlarged and hard ; and Rhazes not only asserted this, but affirmed that it generated fevers. Little attention seems to have been paid to this remark, and in modem times the opinions of Lancisi, that the air of marshes is the sole cause of intennitteuts, has been so generally adopted, that the possibihty of the introduction of the cause by means of water, as well as of aii', was overlooked. Still, it has been a very general behef among the inhfibitants of marshy countries, that the water could pro- duce fever. Henry Marshall ' says that the Singhalese attribute fevers to impure water, " especially if elephants or buffaloes have been washing in it," and it is to be presumed that he referred to periodical fevers. On making some inquiries of the inhabitants of the Jiighly malarious plains of Troy, cluiing the Crimean wai'. Dr. Parkes formd the villagers universally stated, that those who drank marsh water had fever at all times of the yeai', while those who di'ank pure water only got agTie dining the late sum- mer ar;d autumnal months. The same belief is prevalent in the south of India ; and in Western Candeish, Canai'a, Balaghut, and Mysore, and in the deadly "NYynaad district, it is stated by 31r. Bettington of the Madi-as Civil Service, that it "is notorious that the water produces fever and affections of the spleen." Tne essay by this gentleman" gives, indeed, some extremely strong evidence on this point. He refers to villages placed under the same conditions as to marsh air, but in some of which fevers are prevalent, in others not ; the only difference is, that the latter are supphed with pure water, the fonner with marsh or nullah water full of vegetable debris. In one village there were two sources of supj)ly, — a tank fed by sui'face and marsh water, and a spiing ; those only who drank the tank water got fever. In a village (Tulliwaree) no one used to escape the fever ; oMr, Bettington dug a well, the fever disappeai'ed, and, duiing fourteen years, had not returned. Another village (Tambatz) was also " notoriously unhealthy ; " a well was dug, and the inhabitants became healthy. Nothing can well be stronger than the positive and negative evidence brought fcn\"ard in this paper. Dr. Moore ^ also noted his opinion of malarious disease being thus pro- duced ; and M. Commaille ' has since stated, that in Mai'seilles paroxysmal fevers, formerly unknown, have made their appearance, since the supply to the city has been taken from the canal of Mai'seilles. In reference also to this point, Dr. Townsend, the Sanitary Commissioner for the Central Provinces in India, mentions in one of his able reports '" that the natives have a current opinion that the use of river and tank water in the rainy season (when the water always contains much vegetable matter) ■s\ill al- most certainly produce fever (i.e., ague), and he beheves there are many cuTumstances supporting this view. In this way the prevalence of ague in dry elevated spots is often, he thinks, to be explained. He mentions also that the people who use the water of streams draining forest lands and rice fielde " suffer more severely from fever (ague) than the inhabitants of the open plain drawing their water from a soil on which wheat gTOws. In ^ Topography of Ceylon, p. .52. - Indian Annals, 1856, p. 526. ' Ibid., 1867. ' E-ec. de Mem. de Med. Mil., Nov.. 1868, p 427. ^ For 1870, published at Nagpore in 1871, para. 14.3 et seq. 48 ■ PRACTICAL HYGIENE. the former case tliere is far more vegetable matter in the Tvater. The Upper Godavery tract is said to be the most agueish in the province, yet there is not an acre of marshy gi-ound ; the people use the water of the Goda- very, which drains more dense forest land than any river in India. In the "Landes" (of southwest France), the water from the extensive sandy plain contains much vegetable matter, obtained from the vegetable deposit, which binds together the sihceous particles of the subsoil. It has a marshy smell, and, according to Faure, produces intermittents and vis- ceral engorgements. Dr. Blanc, in his papers on Abyssinia, mentions that on the march from ]\Iassowah to the highlands, Mr. Prideaux and himself, who drank water only in the form of tea or coffee, entirely escaped fever, while the others who 'were less careful suffered, as Dr. Blanc beheves, from the water. The same facts have been noticed in this counti-y. Many years ago Mr. Blower of Bedford mentioned a case in which the ag-ue of a ^•illage had been much lessened by digging weUs, and he refers to an instance in which, in the parish of Houghton, almost the only family which escaped ague at one time was that of a fai-mer who used well-water, while all the other per- sons di'ank ditch water.' At Sheerness the use of the ditch water, which is highly impui-e with vegetable debris, has been also considered to be one of the chief causes of the extraordmary insalubrity." At Versailles a sudden attack of ague in a regiment of cavalry was traced to the use of sm-face water taken from a mai'shy district.^ The case of the Argo, recorded by Boudin,^ is an extremely sti'ong one. In 1834, 800 soldiers in good health embarked in thi-ee vessels to pass from Bona in Algiers to Mai'seilles. They all aiiived at Marseilles the same day. In two vessels there were 680 men without a single sick man. In the thii-d vessel, the Ai-go, there had been 120 men ; thii'teen died diu'ing the shori passage (time not given), and of the 107 sunivors no less than 98 were disembarked with all forms of paludal fevers, and as Boudin himself saw the men, there was no doubt of the diagiiosis. The crew of the Argo had not a single sick man. All the sokliers had been exposed to the same influences of atmos- phere before embarkation. The crew and the soldiers of the Ai-go were exposed to the same atmospheric condition during the voyage ; the influ- ence of air seems therefore excluded. There is no notice of the food, but the production of malarious fever from food has never been suggested. The water was, however, different — in the two healthy ships the water was good. The soldiers on board the Ai'go had been supplied with water from a mai'sh, which had a disagi-eeable taste and odor ; the crew of the Argo had pure water. The eridence seems here as nearly complete as could be wished. ^ One veiy important circumstance is the rapidity of development of the malarious disease and its fatahty when introduced in water. It is the same thing as in the case of dian-hoea and dysentei-y. Either the fever- * Snow On the Mode of Communication of Cholera. 2d edit , 1855, p. 130. ' Is it not possible that the great decl.ne of agues in England is partly due to a purer drinking water being now used ? Formerly, there can be no litile doubt, when there was no organized supply, and much fewer wells existed, the people must have taken their supply from- surface collections and ditches, as they do now, or did till lately, at Sheerness. ' Grainger's Report on Cholera, Appendix CB), page 95 ; foot-note. * Traite de Gcographie et de Statistique Medicales, 1857. t. i., p. 142. * Eitter, Hirsch in Jahresb. f lir gen. Med. for 1869, p. 192. WATER. 49 making cause must be in larger quantity in the water, or, "wliat is equally probable, must be more readily taken up into the circulation and carried to the spleen, than when the cause enters by the lungs. In opposition, however, to all these statements must be placed a remark of Finke's,' that in Hungary and Holland marsh water is daily taken with- out injury. But in Hungary, Dr. Grosz states that, to avoid the injurious effects of the marsh water, it is customary to mix brandy with it, "a cus- tom which favors hyjDertrophies of the internal organs."^ Professor Colin, of the Val de Grace, who is so well, known for his researches on intermit- tent fever, ^ is also inclined to question the production of paroxysmal fevers by marsh water. He cites numerous cases in Algiers and Italy, where impure marsh water gave rise to indigestion, diarrhoea, and dysentery, but in no case to intermittent fever, and in all his obser^^ations he has never met with an instance of such an origin of ague. He therefore denies this power, and in reference to the celebrated case of the Ai-go, without ven- turing to contest it, he yet views it with suspicion, and questions whether Boudin has given the exact details. An instructive case, however, is recorded by Brigade-Surgeon Faughf The artillery c[uartered at Tilbury Fort (in the Gravesend district) have gen- erally suffered more or less from ague, whilst the people at the railway station, and the coast-guard and their families in the shij) Ijmg just outside the fort, never suffer from malarious poisoning. The troops have been supj)lied with drinking water fi-om two undergTound tanks which receive rain-water from the roof of the barracks, whilst the other persons above mentioned draw their diinking-water from a spring near the railway sta- tion. From December, 1873, to July, 1874, the troops were supphed from the same soui'ce, on account of the barrack tanks being out of repair. The followinef table shows the retiu-ns of sickness : S aJ O of s a Date. ti •0 M ^'"3 .2.1 s Water used. s -^ i; s "S = r "0.9 s ■§ tf-^ fe m <^ 11^ < ^=5 a 1872. Jan. to June . . . 103 34 33 66 Water from bar- rack tanks. 1873. Jan. to June. . . . 102 12 11.8 23.6 Water from bar- rack tanks. 1873-4. Dec, 1873, to July, 1874. . . . 90 1* 1.1 1.9 Water from spring at the railway station. 1874-5. Nov. , 1874, to March, 1875.. 53 4t 7.6 22.8 Water from bar- rack tanks. The ana]y.ses of the waters showed that the tanks were exposed to soakage from the surrounding salt marsh, for the so-called rain water yielded 41.3 grains per gal- lon of total solids in the one case, and 145.25 in the other, the chlorine being respective- ly 12.8 and 33.9. The station water gave 38 grains total solids and only 3.3 of chlo- rine. As regards organic mat- ter, the tank waters showed actually less impurity than the station water by the am- monia method, but by the permanganate method they were three times as impure. For full details and for the microscopic examination, see the original paper. * This case was in hospital only five davs : it occurred only a few days after the arri~val of the battery, t None of these had ever had ague before; two had to be sent on furlough, being much debilitated by malaria. ' Oesterlen's Handb. der Hygiene, 2d edit., 1857, p. 129 ; foot-note. ^ Quoted by Wutzur, Reise in dem Orient Europas, band i. , p. 101. ^ De ringestion des eaux Marecageuses comme cause de la Dysenterie et dea Fievres Intermittenles, par L, Colin, Paris, 1872. ■'Army Medical Reports, vol. xvii., p. 212. Vol. I.— 4 50 PRACTICAL HYGIEJ!TE. Another case of importance is that recounted by C. Smart, Capt. and Assist. -Surg., U. S. A." In the Rocky Mountain district of North Amer- ica a fever prevails, which is popularly known as the Mountain fexer ; it is evidently malarious, and is amenable to quinine. There is, however, no malai-ious district in the neighborhood, and cases of intermittent fever from the plains recover rapidly there, and the disease occiu-s sometimes when the thermometer is at times below zero, and always below the fi-eez- ing-point, but most frequently at times when fever does not occur in the plains, but which coincide with the melting of the snows, ^-iz., May, June, and July. Dr. Smart found that all the water in the rivers contained a large excess of organic matter, the purest showing from 0.19 to 0,28 per million of albuminoid ammonia, whilst the springs showed only 0.10. The amount was much increased after heavy snow-fall, and on analyzing the snow he was suiimsed to find it contains a large excess of organic matter, esiDCcially that which fell in Large heaxx tkkes (as high sometimes as 0.58 of albxuuinoid ammonia). Dr. Smart concludes that vegetable organic mat- ter is blown up fi-om the plains and precipitated ■v\-ith the snow, and, when the latter melts, canied into the streams. At stations where care is taken with the water-supply, and especially where suspended matter is pre- vented as much as possible from getting into the water, the disease is shght.= The possibihty of the transmission of the poison of paroxysmal fevers through di-inkiug- water must be looked upon as still more probable, should the riews of Klebs and Tommasi-Cmdeli be definitely confirmed. Typhoid Fever. The behef that typhoid fever can spread by means of water as well as air appears to be quite of modei-n origin, though some epidemics, such as the " Schleim-fieber " of GiJttingen in 17G0, were attributed in part to the use of impiu-e water. In 1822, Walz, at Saarlouis, in 18-13, Miiller, at Mayence, and in 18-48, E. A. W. Eichter, at Vienna, published cases illus- trative of this.' In 1852, Dr. Austua Flint' pubhshed the particulars of a similar outbreak of t^•]^)hoid fever at the hamlet of North Boston (Ei-ie, U. S.) m 1843. In 1852-53, a severe outbreak of t^-phoid fever took place at Croydon, and was thoroughly investigated by many competent obsei-^-ers ; and it was shown by Dr. A. Caipeuter that it was partly, at any rate, spread by the pollution of the diinking water from the contents of cesspools. In 1856, Dr. Routh^ and in 1859, Dr. W. Budd" pubhshed very conclu- ' For details see A.M.U. Reports, vol. xix. . p. 190. ' In my Report on Hygiene. A.M.D. Reports, vol. xviii. . an analysis is given of the water of the Rakus Tal Lake on the northern side of the Himalayan range, the sam- ple having been brought home by Lieut. -Col. H. Knight, lale 19th Regiment of Foot. In this water the saline ammonia was O.oO and the albuminoid 0.70 per million. Contrast this with Loch Katrine and other lakes in this country, where the respective amounts are under U.02 and 0.05, and we have a difference which requires explana- tion. May it not be that in this country we have so much less snow as a feeder of our mountain lakes, and also fewer districts from which winds could carry up organic matter? — [F. de C] ^ All these cases are related by Riecko in his excellent work, Der Kriegs und Friedens- Typhus. Xordhausen, 18.50, pp. 44-.')8. ■* Clinical Reports on Continued Fever. By Austin Flint, M. D. Buffalo, 1852. p. 380. ^ Faecal Fermentation as a Cause of Difiease. Pamphlet. Lond., 1856, p. 34, ° Lancet, Oct. 29, 1859, p. 432. WATEE. 51 sive cases. The latter had long been convinced of the occasional propaga- tion of t^^Dhoid fever in this way. In 1860 an outbreak of tj-phoid fever occurred at the Convent of Sisters of Charity at Munich. 31 persons out of 120 were attacked between 15th September and the 4th of October with severe illness, and 14 of these cases were true tyj^hoid ; 4 died. The cause was traced to wells impregnated' with much organic matter (and among other things typhoid dejections), and containing nitrates and lime. On the cessation of the use of this water, the fever ceased.' . The propagation of tyj)hoid fever in Bedford would certainly appear, from Mi\ Simon's report," to have been jDartly through the medium of the water. Dr. Schmitt' has for several years paid particiilai' attention to this point, and in 1861 pubhshed several very striking cases. A case bearing on the same point was brought before the Metropohtan Officers of Health in 1862,* by Mr. "^'ilkinson of Sydenham. In this case the water was contaminated by absolution of sewer gases. In 1862 a vei'y sudden and severe outbreak of tj'phoid in a barrack at Munich was traced to water impregnated with fsecal matter ; — on ceasing to use the water, the disease disappeared.^ In 1865 a veiy remai'kable out- break of tj'plioid occurred at Eatho, in Scotland, and was traced to diinking water contaminated with sewage. "^ In 1866 typhoid fever broke out in a gu'ls' school at Bishopstoke, near Southampton, and was traced unequivo- cally to the bursting of a sewer pipe into the well. The water was disa- greeable both to smell and taste. 17 or 18 j)ersons were affected out of 26 or 28. Several very striking instances are recorded in Mr. Simon's Reports by Drs. Seaton, Buchanan, and Thorne,' and in some of these cases analyses of the water were made, which showed it to be impulse, and to contain or- ganic sewage, or its derivatives. A veiy good case, at the Garnkh'k works in Glasgow, is recorded by Dr. Perry.* Dr. De Eenzy, the Sanitary Com- missioner of the Punjab, has also published a remarkable paper on the extinction of typhoid fever in Millbank Prison, and shows, from the statis- tics of many years, that the fever has entirely disappeared since the use of ' Edinburgh Medical Jonmal, Jan., 1862, p. 1153. See also Gietl, Die Ursachen des Enter. Typhus in Manchen, 1865, p. 58. 2 Third Heport of the Medical Officer of the Privy Council. 1860. ^ Jo urn. de Med. de Bruxelles, Sept., 1861 ; and Canstatt's Jahresb. for 1861, band iv., pp. 182, 183. See the 2d edition of this work for a short account of them. 4 British Medical Journal, March 1, 1862. 5 Gietl. Die Ursachen des Ent. Typhus in Miinchen, 1865. p. 62. In this little book is much evidence to show the propagation of typhoid by foul water and by deficient arrangements for removal of excreta, as well as many instances of the carrying of the disease from place to place, analogous to those narrated by Bretonneau many years ago. ^ Edin. Med. Joum., Dec. 1865. In this case a groom came to the house ill with typhoid from Dundee, and thus introduced the disease. ' Dr. Seaton' s Report on Tottenham (Report of Medical Officer to the Privy Coun- cil for 1866, p. 215j. Dr. Buchanan on Guildford (Ibid, for 1867, p. 34) ; Dr. Thome's Report on Terling (Ibid., p. 41); Dr. Buchanan's Report on Wicken-Bonant (12th Re- port, p. 72). In all these instances the evidence reaches the highest degree of proba- bility, and in the cases of Guildford and Wicken-Bonant of almost absolute certainty. See also Report on Sherborne by Dr. Blaxall ; on Cains College, Cambridge, by Dr. Buchanaa (both in No. ii.. new series) ; on Lewes by Dr. Thome (Xo. iv.. new series); also the case of Over-Darwen (Sanitary Record, 187.5) ; case given by Dr. Stallard (Lan- cet, Feb., 1872) ; Dr. Barclay's Reports on Bangalore (Army Med. Reports, vol. xiii., p. 208). Geissler also quotes from Hagler a very strong case occurring at Lausen. (Schmidt's Jahrb., 1874, No. 2, p. 185.; * Lancet, June, 1868. 62 PKACTICAL HTGIEN'E. Thames "water "was given up ; the disappearance was comcident "with tho change in the water supply. Two excellent cases are recorded by Dr. Clifford Allbutt' and one by Dr. "Wohlrab, which are free from ambiguity.^ A very good case is recorded by Dr. Latham.^ Tyj^hoid was introduced into a ^^llage, and spread by the agency of contaminated ch-inking water. ^ A destiaactive outbreak took place at Caterham and Redhill duiing 1878. This was investigated by Dr. Tliorne Thome, who traced it to contamina- tion of the water-supply by the stools of a workman suffering fi-om mUd t^'phoid, who was emjDloyed in the Company's wells. The disease was con- fined to those who consumed the water, and ceased after the wells were pumjDed out and cleansed. The inmates of the Lunatic Asylum and the de- tachment of troops at Caterham ban-acks used the water from the asylum well, and did not suffer.^ That water may be the mediiim of propagating tyj^hoid thus seems to be proved by sufficient evidence ; and it has been admitted by men who have paid special attention to this subject, as Jenner, W. Budd, and Simon. Two cpiestions arise in connection with this subject — 1. As typhoid lever undoubtedly spreads also through the air, What is the proportion of cases disseminated by watei-, as compared with those dis- seminated by ail'? No answer can yet be given to this question. ° There is one point of some interest. '\Yhen the dates of attack are given, it is curious to observe how short the incubative period apjiears to be ; while it is j^robable that it takes many days (8 to 14) after the tyjDhoid jDoi- son has entered with the air before the early malaise comes on, in some of the cases of tyi)hoid brought on by water, two or three days only elapse before the symptoms are marked.' A very large number also of the susceptible persons who drink the water are affected. 2. "Will decomposing sewage in water produce typhoid fever, or must the evacuations of a typhoid j^atient pass in ? This is pari of the larger question of the origin and j)ropagation of specific poisons. It is certainly remarkable, in the range of cases recorded by Schmitt, how uniformly the possibility of the passage of typhoid stools is disregarded. Everything is attributed to fsecal matters merely. A case recorded by Dr. Downes,* in ' See Report on Hygiene, Army Med. Dept. Bl'^e Book, 1860, p. 23. * Archiv der Heilk., vol. xii., p. 1,'A (1871). ' Lancet, July 15, 1871. ■* A remarkable case is reported by Dr. Zuckschwerdt occurring in the orphr.n asylum at Halle in 1871. Also by Dr. Burkart at Stutt<.'art, at Reinhartsdorf in Switz- erland, and at Schandau, all distinctly traceable to impure water. (Schmidt's Jahr- biicher, 1874.) ^ See Report, by Dr. Thome Thome ; also A.M.D. Reports, vol. xx.. p. 222. * Mr. Simon, in his second Report, new scries, gives a ta!)le of 14t) outbreaks inves- tigated by his officers in 187u-7y (4 years), in all of which great escremental pollution of air or water, or generally of both, was found. Biermer. from an analysis of 1,800 cases, cites evidence of water carriage (Schmidt's Jahrb., 1878, No. 8, p. i9.j). * Dr. W. Budd says, in a letter to the late Dr. Parkes, — '• In the cases in which the poison is conveyed by water, infection seems to be much more certain ; and I have reason to think that the period of incubation is materially shortened. An illustration of this seems to be furnished by the memorable outbreak which occurred at C'owbridge some years ago, and which pre.sented this unexampled fact : that out of some 90 or 100 persons who went to a race ball at the principal inn thf-re. more than one-third were within a short time laid up with fever. In this case there was satisfactory rea- son to think that the water was contaminated, though there was no chemical exami- nation." In the attack at Gu'ldford. however, the incubative period was not shortened, as Dr. Buchanan calculates it at 11 days; neither was it shortened at Caterham. 8 Lancet, April 27, 1872. WATEE. 53 which six eases of typhoid resulted from the overflow of non -typhoid sew- age into a well, supports this view. On the other hand, in the cases re- corded by Allbutt and Wohlrab, already referred to, contaminated water had been used for some time without producing typhoid fever. Persons affected with typhoid (enteric) fever then entering the place, theii- dis- charges passed into the drinking water, and then an outbreak of typhoid, followed. An extremely strong case is given by Ballard.* Very polluted water had been used for years by the inhabitants of the village of Nunney without causing fever, when a person with enteric fever came from a dis- tance to the village, and the excreta from this person were washed into the stream supplying the village. Between June and October, 1872, no less than 76 cases occuiTed out of a poiDulation of 832 persons. All those at- tacked drank the stream water habitually or occasionally. All who used filtered rain or well water escaped, except one family who used the water of a well only 4 or 5 yards from the brook. The case seems c[uite clear — first, that the water caused the disease ; and secondly, that though polluted with excrement for years, no enteiic fever appeared until an imj)ortant case in- troduced the vii'us. Positive e\ldence of this kind seems conclusive, and we may now safely assume that the presence of typhoid evacuations in the water is necessary. Common fsecal matter may produce diarrhoea, which may perhaps be febrile," but for the jDroduction of enteric fever the speci- fic agent must be present. The opinion that the stools of typhoid are the special carriers of the poison was first exphcitly stated by Canstatt,^ and was also ably argued by W. Budd. Cholera. Few of the earlier investigators of cholera appear to have imagined that the specific poison might find entrance by the means of drinking-water. There is an intimation of the kind in a remark by Dr. Miiller ;* and Jame- son ^ alludes to the efiect of impiu-e water, but in a cui'sory way. In 1819 the late Dr. Snow, in investigating some circumscribed out- breaks of cholera in Horsleydown, Wandsworth, and other places, came to the conclusion that, in these instances, the disease arose from cholera evac- uations finding their way into the drinking water. Judging from the light of subsequent experience, it now seems extremely probable that this was the case, and to Dr. Snow must certainly be attributed the very great mer- it of discovering this most important fact. At first, certainly, the evidence was defective, '^ but gradually fresh instances were collected, and in 1854 ' Report to the Local Government Board, on an outbreak of enteric fever at Nun- ney. Sept.. 1872. 2 A good instance is given by Mr. R. Bond-Moore (London Medical Record, May 27, 1874, page 827), as occurring at Sedgely Park school. Two years previously the water supplv' became contaminated with ordinary sewage, but no typhoid fever resulted, al- though there was diarrhcea, sicknes^i, great languor, and great prostration. The leak- ing drain was repaired, and the attack ceased. Two years after, typhoid was intro- duced by one of the boys, and spread apparently by the use of the closets. 2 '• Wahrscheinlich sind die Exhalationen des Krankes, seine Excremente. vielleicht die typliosen After gebilde im Darme, die Triiger des Contagiums." — Canstatt, Spec. Path, und Ther., 2'd edit., band ii., p. 572 (1847). " Einige Bemsrkuugen iiber die Asiat. Cholera. Hanover, 1848, p. 36. " Bengal Report of 1820. * There seemed at once an a priori argument adverse to this view, as, at that time, all evidence was against the idea of cholera evacuations being capable of causing the disease. They had been tasted and drunk (in 1832) by men. and been given to ani- .mals, without effect. Persons inoculated themselves in dissections constantly, and 54 PRACTICAL HYGIENE. occuiTed the celebrated instance of the Broad Street pump in London, Avhich was investigated bv a committee, whose report, drawn up by Mr. John Marshall, of University College, with great logical power, contains the most convincing evidence that, in that instance, at any rate, the poison of cholera found its way into the body through drinking-water/ In 1855 Dr. Snow published a second edition of his book, giving an account of all the cases hitherto known, and adding some evidence also as to the introduction in this way of other specific poisons.* The facts, at present, may be briefly summed up as follow^ : — 1. Local outbreaks, in which contamination of the drinking-water was either proved or in which the evidence of the origin and succession of cases seemed to make it certain that the cause was in the drinking-water. In England, Dr. Snow and others have thus recorded cases occurring in 1849 and 1854 at llorsleydown, Broad Street, Wandsworth, West Ham, etc. In 1865 the important outbreak at Newcastle-on-Tyne,' when all the cir- cumstances pointed veiy strongly to the influence of the impure Tyne water. In 1865 occurred the remarkable and undoubted case of water poisoning at Theydon Bois, recorded by Mr. Radcliffe,* and in the following year the violent outbreak in the East of London was sujoposed to be connected with the cii'culation of impure water by the East London Water Works Com- pany. Much discussion has taken place as to the real influence of the im- pure water, which it is admitted on all hands was used. Mr. Eadclifl'e ^ and Dr. Farr " collected the evidence in favor of the opinion that the sud- den outburst was really oAving to this water ; while Dr. Letheby and some others expressed doubts on this point, chiefly on account of the diflficvilty of reconciling with the hv7)othesis certain exceptional cases both of immu- nity and of attack. The evidence in favor of the water being the cause ap- j)ears extremely strong, and far greater difficulty arises if that view is not received than is caused by the exceptional cases referred to, and of which we may not know all the particulars. In the same year (1866) an appar- ently unequivocal case of production of cholera by the drinking of water of a tank on board a steamer occuiTed at Southampton.' A veiy striking case at Utrecht is noticed by Snellen,'^and is given by Dr. Ballot, of Rotterdam, who has adduced much strong evidence on the influence of the foul water in Holland in spreading cholera.* bathed their hands in the fluids of the intestines ; in India the pariahs who removed excreta, and everywhere the washerwomen who washed the clothes of the sick, did not especially suffer. And to these arguments must be added the undoubted fact, that there were serious deficiencies of evidence in Dr. Snow's early cases. (See review by Dr. Parkes in the British and Foreign Medical Chirurgical Review, April, 1S55.) ' Report on the Cholera Outbreak in St. James's, Westminster, in 1854. London, Churchill, ISoo. Every point is discussed in this Report with a candor and precision which leaves nothing to be desired. For further evidence on this outbreak, see Indian Sanitary Report : evidence of Dr. Dundas Thomson, p 272. '' On the Mode of Communication of Cholera. By John Snow, M.D. London, Churchill, 2d edition, 18r>5. ^ For full particulars, see Dr. Farr's Report on Cholera in England. 1806, p. 33. ■* Report of the Medical Officer to the Privy Council for 1865 (Eighth Report), p. 438. 5 Report of Ihe Medical Officer to the Privy Council for 1866. p. 266. * Report on the Cholera Epidemic of 1866 in England. Supplement to the 29th Annual Report of the Reo-istnir-General, 1868. ^ Report of Medical Officer to Privy Council for 1866, p. 244. In this case the water was foul tasted, and was certainly contaminated with s-ewage. " Medical Times and Gazette, May, 18()fl. Thus it was found that those who drank the water of the Polders (reclaimed lands) died at the rate of 17.7 per 1,000 ; those who drank the well-water, 16.8 per 1,000; those who drank river-water, 11.9 per WATEE. 00 During tlie epidemic in 1866, except in the East London case, no such striking instances of local outbreak ti'oni vrater contamination were re- corded as in 1819, but there were in some parts, and especially in Scot- land, as noticed by Dr. Stevenson ]\lacadam,' very striking coincidences between the abatement of the disease and the introduction of a fi-esh and pm'e supjoly. In Germany choleraic water-poisoning has not only been less noticed, but the gi-eat authority of Pettenkofer is against its occui-rence. At Mu- nich, Pettenkofer' could find no evidence whatever in favor of the spread by water, nor does he consider that any fiu'ther evidence was fui-uished by the epidemics in Germany in 1873-71.^ Even Hii'sch, who was favorable to the water theoiy, expresses himself -oith considerable caution ; ^ and Giinther, in his careful Avork on Cholera in Saxony, ° asserts that no influ- ence whatever was exerted by di'inking-water. No evidence could be ob- tained either in Baden or in villages neai- Vienna.* And as in all cases the observers were not only quite competent, but were fully cognizant of the opinions held in England, this negative evidence is of gi'eat weight. At the same time, it cannot be allowed to outweigh the Enghsh cases, and, moreover, even in Germany some positive evidence has been given. Dr. Eichter ' attributes a preponderant influence in a local outbreak among the workmen of a sugar-manufactory to the pollution of the drinking water by sewage ; and a still more striking case is recorded by Dr. Din- ger,* in which the discharges of a cholera patient passed into a brook, in which also the clothes were washed ; the water of this brook being used for drinking, there was a sudden and very fatal outbreak aftecting the per- sons who took the water. In India the evidence for cholera water poisoning has now become veiy strong. The gi-eat cholera outbreak of 1860 and 1861 was attributed by some medical officers to the defilement of the tank water "into which the general ordure of the natives is washed dui-ing the rainy season ; " " and still more recently, what appears to be a striking instance has occurred. No one can read the able account given by Dr. Cuningham and Dr. Cut- liffe^' of the apj)earance of cholera among the vast crowd of pilgTims after the great bathing day at Hurdwar, without coming to the conclusion that it was a case of water-poisoning on a gigantic scale. Cholera broke out again at Hurdwar in 1879 (the pilgrimage takes place every twelve years), but in his report on this epidemic Dr. J. M. Cuningham endeavors to thi-ow doubts upon the propagation by means of water. The circum- 1,000; those who drank rain-water filtered, only 5.3 per 1,000. The city of Amster- dam itself, supplied by an aqueduct with rain-water from the downs near Haarlem, had only 4 per I.UOO. In Rotterdam, during; the epidemic, the mortality fell to one- half immediately on pure water being supplied in the streets. (See paper by J. C. Jager. ) ^ Transactions of the Eoyal Scottish Society of Arts, vol. vii. , p. 341 (1867). - Zeitsch. fiir BioL, band i. . p. 353. '' Ueber Cholera and deren Beziehung zur parasitaren Lehre, von Mas von Petten- kofer, 1S80. •* Berieht der Commission des Deutschen Eeiches, heft i. , saite 13. ^ Die I-dische Cholera in Sachsen im Jahre 1865, p. 125. * Volz and Witlacil, quoted by Hirsch in Jahresb. der gen. Med. for 1867. band ii., p. 221. '' Archiv der Heilk. , 1867, p. 472. * Ibid. , p. 84. ' M'William, Epidem. Society Trans., vol. i., p. 274. '" Report, of the Sanitary Commissioner with the Government of India for 1S67. Calcutta, 1868. 56 PRACTICAL HYGIENE. stances, however, were very similar in the two cases.' Drs. T. Lewis and Douglas Cunningham discredit the influence of water;" and Dr. D. Cun- ningham stiys,' — " One point seems worthy of remark, and that is, that there is no evidence of tlie existence of any common condition affecting local sources of water suj^ply, and simultaneously affecting the prevalence of cholera and bowel-complaints." That in India, liowever, the cholera poison is often caiiied by water appears j)robable, not only from the Hm-dwar outbreaks, but from the very sudden and violent outbreaks and the great sewage contamination in the Avater of many districts.^ In Central India Dr. Townsend^ has given strong reasons for behe^dng that the cholera of 18G8-69 was, to a large extent, dependent on water- fouling. Dr. Macnamara" has given some good evidence on the same side, and Dr. Cleghom' has noted some striking proofs of the same fact.* Dr. ]\L C. Farnell, Sanitary Commissioner of Madras, points out the immunity of Madras from cholera since the new water supply was obtained from the Red HiUs ; the same immunity extending to the districts using the water, whereas other places which do not use it still suffer from the disease. Guntur always suffered from cholera up to 18G8, since which time it has been j^racticaUy free, following the greater care for the water supply begun by Dr. Biggwither and carried out by Dr. TyrreU." A re- markable case is recorded by the Rev. J. Delj)ech, at Vadakencoulam. '" Cholera was confined to the higher castes, who drank of a particular well exposed to contamination. Among the lower castes none suffered, except one woman who Avashed for the higher caste women. The lower caste people drank from other wells, which were less exposed to pollution. So also in other countries ; in the attack which caused such losses to the French Division in the Dobnidscha in 1855, when the wells were sup- posed to be poisoned, and to the English cavah'y at Devna," the water was apparently the means of carrying the disease. In evidence of this kind, we must remember that each successive in- stance adds more and more weight to the instances previously observed, ' See Fcction vi. of the Sixteenth Annual Report of the Sanitary Commissioner with the Government of India, 1880. ^ Cholera in Relation to Certain Physical Phenomena. ^ Medico-Topographical Report on Calcntta. * Vide Report on the Sanitary Administration of the Punjaub for 1867, and sub- seqtient years, by A. C. C. De Renzy, Esq. (Cases of Peshawur and Amritzur.) ^ Report on Cholera in the Central Provinces. * On Asiatic Cholera, see pp. <328 et seq. ' Indian Medical Gazette, March, 1873. * See also the remarkable case of the Yerrauda gaol, reported by Surgeon-Major H. Blanc. Out of 1,279 prisoners there were 24 cases of cholera in 5 days, with 8 deaths. Of those, 22 cases occurred among lo4 prisoners employed as a road-gang, and only 2 among all the others variously employed. It was shown that the road- gang alone drank of water from the Mootla River, a little below the spot where the clothes of two cholera patients from the village had been washed and their bodies burnt a few days before. The rest of the prisoners drank the usual water supply laid on from a lake near Poonah. In the two cases among those otherwise emploj'ed direct infection was undoubted in one, as he attended on cholera patients, and, c n- trary to orders, took his meals in the cholera ward, and drank water that had been standing there; the other man slept near one of the first cases, the patient vomiting in his immediate vicinity. " Indian Medical Gazette. AprU, 1883. "'Ibid., December 1, 187.9. " MS. essay of Dr. Cattell. WATER. 5T until, from tbe mere accumulation of cases, the cogency of the argument becomes irresistible. 2. The evidence derived from such local outbreaks is supported by that drawn frora the history of more general attacks, in "svhich districts supplied with impure water by a water company have suffered gTeatly, while other districts in the same locality, and presenting otherwise the same conditions, were supphed with ptu'e water, and suffered very httle. Thus the Regis- trar-General has shown that the districts supplied in 1853, pari by the Lambeth Company with a pui-e water, and part by the Southwark Com- pany with an impure water, suffered much less than the districts supphed by the latter company alone (the proporiion was 61 and 94 cases respec- tively to 100,000 of population). Schiefferdecker, in KlJnigsberg, has also given evidence to show the different extent in which districts in the same city supphed with pui-e and impure water suffer. ^ In Berlin, in 1866, in the houses supphed with good water the number of houses in which cholera occuiTed was 36.6 per cent. ; in the houses with bad water was 52.3 per cent.'^ 3. Additional arguments can be drawn from instances in which towns which could not have had water contaminated with sewage have escaped, and instances in which towns which have suffered severely in one epidemic have escaped a later one, the only difference being that, in the interval, the supply of water was improved. Exeter, Hull, Newcastle-on-Tyne, Glasgow, and Moscow are instances of this. Tt\'o very good cases are related by Dr. Acland.^ The parish of St. Clement was supplied in 1832 with filthy water from a sewer-receiving stream. In 181:9 and 1854 the water was fi'om a purer source. In the first year, the cholera mortality was great ; in the last years, insignificant. In Copenhagen a fresh water supply was in- troduced in 1859. Although cholera had prevailed veiy severely there previously, in 1865 and 1866 there were only a few cases. ■* In Haar- lem, in Holland, cholera prevailed in great intensity in 1849. In 1866 it returned, and again prevailed as severely in all parts of the town except one. The pari entuely exempted in the second epidemic was inhabited by bleachers, who, between 1849 and 1866, had obtained a fresh source of pure water. ^ In looking back, with this new reading of facts, it would seem that some older reported cases of sudden cessation of cholera can be explained, such as the case of Breslau, in 1832, when the shutting up of a pump was fol- lowed by the very rapid dechne of the disease. Doubtless, however, in other cases the causes of the cessation are different ; hea^w rain, by cleans- ing arr and sewers, and by stopping the evolution of effluria, will sometimes as suddenly aiTest cholera. Most important evidence is given by Professor Forster of Breslau.'' He shows that five towns of Silesia (of 5,000 to 12,000 inhabitants) are entirely free from cholera, which never spreads, even when introduced. The only common condition is a water supply from a distance which cmmol be contaminated. In Glogau (13,000) half the water is from a distance and half from wells : those using the former remain free, those using the latter are attacked. In one case in Breslau, on a well becoming 1 See Report on Hygiene, Army Med. Dept. Report, vol. xii. , p. 241. ^ Die Kanalisation von Berlin. 1868, p. 30. 3 Cholera in Oxford in 1854. by H. W. Acland, M.D., p. 51. '^ Hornemann in Virchow's Archiv, band .53, p. 156. 6 Ballot, British Med. Journal, April, 1869. ^ Die Verbreitung der Cholera durch die Bronnen, Breslau, 1873. 58 PRACTICAL HYGIENE. contaminatecl, eleven persons were immediately attacked. ' Dr. A, Fergus'' has pointed out that in Glasgow, when the whole city was supphed from the river, cholera was universal in 1848 ; whilst in 1854 it was chiefly con- fined to the north side, which still di-ew water from the river, the south Fide with a pure water supply being practically free from it. In 1866 the whole city had the pure Loch Katrine supply, and, although cases of cholera were imported, it got no hold on the city whatever. So also other curious facts in the history of cholera become explicable. The prevalence of cholera in Eussia, with an outdoor temperature below zero of Fahr., has always seemed an extraordinary circumstance, which it appeared only jjossible to explain by supposing that, in the houses, the foiil air and tlie artificial temperatm-e must have given the poison its neces- sary conditions of development. But Dr. Routh has pointed out ' that, in the poorer Eussian houses, every thing is thrown out round the dwellings ; then, owing to the cold and the expense of In'inging drinking water from a distance, the inhabitants content themselves with taking the snow near their houses and melting it. It is thus easy to conceive that, if cholera evacua- tions are thus thrown out, they may be again taken into the body. This is all the more likely, as cholera stools have little smell or taste, and, when mixed even in large quantity -with, water, cannot be detected by the senses. We may therefore conclude that the cholera evacuations, either at once or after undergoing some special fermentative or transformation change, pass into drinking water or float about in the atmosphere. In either case they are received into the mouth and swallowed, and produce their effects directly on the mucous membrane, or are absorbed into the blood. The relative frequency of each occui'rence, the incubative jDeriod, and the sev- erity of the disease jiroduced, are points still uncertain. C. Macnamara states ^ that the dangerous period is when the water into which cholera stools are passed is swarming with vibriones, and that when ciUated infusoria appear danger is over. He speaks strongly on this point, and from actual experience. In addition to the production of cholera from drinking-water containing the cholera stools, it has been supposed that the use of impure water of any kind ]jredif- Description oi' Plate II. Sediment of Ditch Water, draion with the Camera lucida at the distance of 10 inches from eye-piece to paper. a Decaying vegetable matter, cellular tissue, x 108. h Pleurosigma formosuiii, before di\idiag, x 170. c Oxytricha gibba, x 108. d Ampliileptus auser, x 170. e Euglena \ii-idis, x 285. f Supposed urceola of some rotifer, x 108. g Surii-ella gemma, x 108. h Do. do. x 65. i Foraminifera, x 65. j Traclileocerca linguifera, x 65. k Small Planaiia ? ovisacs distended, x 65. I Navicula vii-idis, x 285. m Paramecium aurelia, x 170. n Coleps liirsutus, x 285. o Pleuronema crassa, x 285. p Moniu'a dulcis, x 170. q Surirella splendida, x 170. r Biddulplna pulchella, x 285. s Sui-u-ella striatula, x 170. t Rotifer, Mouolabis conical? x 108. u Ai'egma, spore cases, x 285. V Stentor ceiiileus ? do. v. x contracted, x 170. to Trineiiia acinus ? x 170. X Pinnularia grandis, x 170. y GjTOsigma angulatum before dividing, x 170. z Alyscum saltans? x 170. aa Synedra ulna, x 170. hh Amplnprora alata, x 285. cc Gyrosigma Spencerii, x 285. dd Nitzscliia sigma, x 170. ee Brachionus angularis, x 170. ff Young Vorticella ? x 170. gg Gyrosigma fasciola, x 285. hh Traclielius strictus, x 285. ii Cocconema Boeckii, x 170. jj Confervoid cell ? with divided protoplasm, x 285. kk Euplotes Charon, x 170l Plate Description of Plate IEL Drawing of Sediment in Thames Water, taken just above Teddington Lock, in April, 1878. Notice the evidence of impui^ities from men, viz., epithe- lium, woollen, cotton, and flax fibres. Fig. 1. Coleps hirsutus. 2. Bodo grandis. 3. Actinophrys Eicliornii. 4. Epithelium (tessellated). 5. Leucoplirys striata. 6. Anguillula fluviatilis. 7. Paramecium chrysalis, dividing (? sexual stage). 8. Vorticella microstoma. 9. Kerona, young? 10. Vorticella microstoma (stemless). 11. Paramecium aurelia. 12. Conferva. 13. Cocconema lanceolatum. 14 Synedra splendeus. 15. Gyrosigma attenuatum. 16. Gomphonema acuminatum. 17. Wool fibre, dyed. 18. Cotton fibre, dyed. 19. Conferva floccosa. 20. Hair, barbed, of? 21. Kerona mytilus. 22. Siliceous spicule. 23. Diatonia vulgare. 24. Fungi (? Torula). 25. Flax fibre. 26. Arthrodesmus quadricaudatus. 27. Stylonichia? histrio, diriding. 28. Paramecium caudatum. 29. Woody fibre, ? rootlets. 30. Pollen. 31. Vegetable tissue and mycelium, -with spores. 32. Decaying vegetable matter. 33. Gomphonema curvatum. 34. Spores of Fungi (? Aregma). 35. Ajitherozoid of ? 36. Encysted spore. Decaying vegetable matter and infusoria abundant. Plate III. ^So Plate IV. References. a, a, a, Bro-wn Vegetable Cells (probably Sporangial), probably disengaged gonidia of 6, Scales of Epithelium. lichens (Leighton). c, Glaucoma Scintillans. d, Monas Lens. e, e, Aspidisca Denticulata, or Coccudina. /,/, Oxytriclia Gibba ; /' young. ^, Vorticella Convallaria. Ti, Bacterium Termo in a broad sheet. «, Localized Groups of a larger form. k, Crystalline Particles, probably quartz Hammer- Somerset smith. House. Greenwich. Woolwich. 45.2 55.6 48.3 4.1 1.5 .25 .25 15.1 16.2 15.4 14.5 WATER. 75 Gases. — Oxygen, nitrogen, carbon dioxide, hydrogen sulpLide, and carburetted hydrogen are the most usual gases. If the »three former co-exist, as is generally the case, the oxygen is usually in larger rela- tive amount than in atmospheric air, as it often reaches 32 per cent.^ The amounts of oxygen and carbon dioxide depend so much on varying conditions, such as the amount of exposure to the air, the growth or ab- sence of plant life, and the presence of animals, as to render the propor- tions, absolute and relative, of the gases so variable, that few inferences of hygienic importance can be drawn from their determination. A lessen- ing, however, at one j)art of its course, in the quantity of oxygen which a certain water is known to contain, may be useful, as pointing out that organic matter has been in the water. ^ Thus Professor MiUer found that Thames water contained the follow- ing amount of gases in C.C. per litre, in its flow down stream : — Kingston. Carbon dioxide, . 30.3 Oxygen, 7.4 Nitrogen, 15. The stability of the nitrogen, the increase in the C0„, and the lessen- ing of the oxygen, are well seen. If water contain much CO.,, bubbles of the gas form on the sides of the glass in which the water is j)laced. So far as our knowledge extends at present, there seems to be but little in- formation obtained by the determination of the amount of gases in water ; but if it is decided to do so, we require a mercurial trough, a graduated tube-measure to be filled with mercury and inverted into the trough, a flask and a connecting tube with a bulb blown on it. The flask is filled with water and connected with the bulb-tube by an india-rubber tube, which is to be closed by a clamp. Some water is put into the bulb, and boiled ; this is to expel air from the connecting tube ; and when this is done, the end of the tube is put into the mercurial trough under the ves- sel filled with mercury, the clamp is removed from the india-rubber tube, and the water is cautiously boiled for an hour. The gases collect in the mercurial tube, and are measured (due regai-d being had to temperature and pressure, and the other corrections) ; the C0„ is absorbed by potash, the oxygen by potassium pyrogaUate, and the nitrogen is read as the residue. As regards the CO^, there is an objection to this method, as the heat decomposes the calcium and magnesium bicarbonates, and therefore the amount of CO, evolved is greater than existed in the water as free car- bonic acid. On the other hand, it is impossible by heat alone to obtain all the oxygen and nitrogen.' ' Atmospheric air, according to Bunsen's co-efficients of absorption, ■would dis- solve in water in the proportion of 65. 1 of nitrogen and 34. 9 of oxygen^ — Wanklyn, Wj,ter Analysis, p. 103. '^ Up to recently Gerardin considered that the degree of oxygen (oxymetrie) was the best test of a water's purity. He has since modified this view considerably. The importance of the indication is also greatly lessened by the fact that deep well waters, of undoubted potable excellence, yield extremely little oxygen — often not more than the Thames at Woolwich. ^ The plan of determining the oxygen by means of the sodium hydrosulphite, sug- gested by Schiitzenberger and G-orardin, is ingenious and rapid, but it has the incon- venience of requiring the reagent to be freshly prepared, as ic will not keep. (See Comptes llendus de I'Academie des Sciences ; Lefort, Traite de chimie hydrologique ; Annales d' Hygiene, Janvier, 1877.) 7G PRACTICAL HYGIENE. As this operation is a rather delicate one, and requires some practice, and as the information it gives, in a hygienic point of view, does not ap- pear to be so nseful as that obtained by other methods, it my be omitted except in cases where the amount of aeration is considered veiy important. The amount of free CO., can also be determined approximately by the soap solution subsequently described. Dr. Macnamara has proposed ' a still simpler method for the examination of water in India. Dr. Fi'ankland has proposed a very ingenious plan for extracting the gases from water without heat. It is an application of the Sprengel pump, in which the Torricellian vacuum of a barometer is made to act as an air-pump. The gases can be extracted either at the ordinary or boil- ing temperature. This plan may be useful in laboratories Avhere miach ■water analysis is carried on, but it can hardly at present be applied by army medical officers. Hydrogen sulphide sometimes occurs in water as a consequence of the decomposition of sulphates by organic debiis, even by the cork of the bot- tles, the SH., being afterwards liberated by carbonic acid. In some min- eral waters (Marienbad) hj'drogen sulphide aj^pears when algce are in the water, but not without. ^ If the gas is present in any quantity, it can be detected by the smell. Alkaline sulphides have, however, less smell. Both, even without smell, can be detected by salts of lead. A large quantity of water should be taken in an evaporating dish, and a little clear lead subacetate or acetate allowed to flow tranquilly over the surface. Black fibres of lead sulphide are formed. If lead acstate is mixed with solution of soda until the pre- cipitate which at first forms is redissolved, a very delicate test-liquor is obtained. Solution of sodivim nitro-pi-usside is also a delicate test, and gives a beautiful violet-purple color. As it acts only on the alkaline sul- phides, a little solution of soda or ammonia must also be added to detect the free hydrogen sulphide. Cai'buretted hydrogen in small quantity in water is not readily detected, but Tiemann says that warming the water to 110° Fahr. will enable the smell to detect coal-gas, when chemical reagents fail. Generally there are other impurities, especially if it be derived from gas impregnation. In larger quantity it sometimes bubbles up from the water of stagnant pools, particularly if there be much vegetable matter ; and in the cases of some natural springs in petroleum districts, can be ignited. Dissolved Solids. The chemical examination of the dissolved matters is divided into the qualitative and the quantitative. QuALITATrV'E EXAMINATION OP DlSS0L\^ED SoLIDS. The water may be either at once treated, or, in the case of some con- stituents, it should be concentrated by evaporation. ' Scheme of Water Analysis for India. ^ Archiv. fiir Wiss. Heilk., 1864, No. III., p. 261. WATEE. 77 Wafer not Concentrated. Substance sought for. Eeaction . Lime Chlorine Sulphuric Acid . Nitric Acid . Nitrous Acid Ammonia Reagents to be used, and efEects. Litmus and turmeric pa- pers ; usual red or brown reactions. Oxalate of ammonium. Wiiite precipitate. Nitrate of silver, and dilute nitric acid. White precipitate becoming lead color. Chloride of barium and dilute hydrocliloric add. White precipitate. Brucine solution^ audi pure sulphuric acid. A pink and yellow zone. Iodide of potassium ' and stoj'ch in solution and di- lute sulphuric acid. An immediate blue color. Solution of metaphenylene- diamine and dilute sul- phuric acid (G-riess' test) — a yellow color more or less immediate according to amount of nitrous acid. Ne-ssler^s solution. ^ j A yellow color or a yellow brown precipitate. Usually neutral. If acid, and acidity disappears on boiling, it is due to car- bonic acid. If alkaline, and alkalin- ity disappears on boiling, to ammonia (rare). If permanently alkaline, to sodium carbonate. Six grains per gallon give turbidity; sixteen grains considerable precipi- tate. One grain per gallon gives a haze ; four grains per gallon give a marked tur- bidity ; ten grains, a considerable precipitate. One and a half grain of sulphate gives ■ no precipitate until after standing ; three grains give an immediate haze, and, after a time, a slight precipi- tate. The sulphuric acid should be poured gently down to form a layer under the mixed water and brucine solu- tion ; half a grain of nitric acid per gallon (=0.7 per lOO.OUO) gives a marked pink and yellow zone ; or, as recommended by Nicholson, 2 C. C. of the water may be evaporated to dryness ; a drop of pure sulphuric acid and a minute crystal of brucine be dropped in; .01 grain per gallon (=.0143 per lOO.OOU) can be easily detected. Add the solution of iodide of potassium and starch, and then the acid ; the blue color should be immediate ; make a comparative experiment with distilled water. This is a very delicate test ; a yellow color will appear in the. water in half an hour, if there be only one part of nitrous acid in 10,000,000 of water. If in small quantity, several inches in depth of water should be looked down through on a white ground. ' See Appendix A, vol. ii. 78 PRACTICAL HYGIENE. Water not Concentrated — Continued. Substance sought for. Iron Beagents to be used, and efEects. Bemarks. Bed and yeUoi/j prussiateJi of pota.<e constituents, f Ammonia free with the oxidizable org.anic Ammonia albuminoid. . matter, indicated bv the oxv- K -kt-.. • • j i-Kr\ \ gen required, are ihcludedln | ^}^r\Q, acm (.WUs) the Volatile Matter. l^ Nitrous acid (NOo) Total nitrogen included in ) nitrates and nitrites ) Chlorine Calcium carbonate Fixed hard salts Sulphuric acid (SO4) Alkaline carbonates Sodium or other metal (combined with CI or SO4) ) not included in fixed hard salts ) Silica, alumina, iron, etc Total solids (by evaporation) Microscopic Clutracters. Jtemarks. Laboratory, Army Medical School, Royal Victoria Hospital, Netley, Professor of Military Hygiene. "WATER. 103 The following tables give an approximate view of the composition of drinking waters of the four classes : 1. Pure and Wholesome Water. Character or Constituents. Physical characters : Colorless, or bluish tint ; transparent, sparkling, and well aerated ; no sediment visible to naked eye ; no smell ; taste palatable. Chemical Constituynts. 1. Chlorine in chlorides under 2. Solids in solution : total . . under Solids in solution: -volatUejindcr N.B. — The solids on incinera- tion should scarcely blacken. 3. Ammonia, free or saline, .under Ammonia, albuminoid . . . under 4. Nitric acid (NOa), I ^,^^,^ m nitrates ) Nitrous acid (NO2), ) in nitrites f Nitrogen in nitrates under Total combined nitrogen, in- cluding that in the free am- monia under Total nitrogen, including that in the albuminoid am- monia under 5. Oxygen absorbed by organic matter within half an hour, by permanganate and acid at 140' F. (60' C.) under Do. in fifteen minutes, at 80° F. (27' C.) under Do. in four hours, at 80° F. (27' C.) under 6. Hardness, total under Hardness, fixed under 7. Phosphoric acid in phos- phates Sulphuric acid in sulphates .... 8. Heavy metals 9. Hydrogen sulphide, alkaline sulphides Grains per gallon, 1 in TO.OOO. 1.0000 5.C000 1.0000 0.0014 0.0035 0.0226 nil. 0.0100 t 0.0113 [ 0.0160 i- 0.0175 0.0100 0.0350 6.0° 2.0° traces. traces, nil. nU. Centi- grammes per litre, 1 in 1C.U,0U0. 1.4000 7.1428 1.4000 0.0020 0.0C50 0.0323 nil. 0.0140 0.0160 0.0230 0.0250 \ 0.0125 0.0500 8.5° 8.0° Microscopic characters: Mineral matter; vegetable forms with endochrome ; large animal forms ; no organic debris. Turbidity, due to very fine mineral matter, is sometimes associated with pure waters; thus, minutely divided cal- cium sulphate will not subside in distilled wa- ter. This may be exceeded if from a purely mineral source. The solids may be ex- ceeded in chalk waters, where they are mostly calcium carbonate. The oxygen absorbed may be doubled in peat or upland surface wa- ters. A water such as the above may generally be used with confidence, in the absence of any history of possible pollution, or of any recent and appreciable change in the amount of the organic constituents. 104 PEACTICAL HYGIENE. 2. Usable Water. Character or Constituents. Physical characters : Colorless, or slightly greenish tint ; transparent, sparkling, and well-aerated ; no suspended matter, or else easily separated by coarse filtration or subsidence ; no smell ; taste palatable. Chemical Constituents. 1. Chlorine in chlorides under 2. Solids in solution : total . . under Solids in solution : volatile, under 3. Ammonia, free or saline, under Ammonia, albuminoid . . . wider 4. Nitric acid (NO3), ) , ., , ^' >• under m nitrates. . . . ) Nitrous acid (NO2), ^ in nitrites \ Nitrogen in nitrates under Total combined nitrogen, in- cluding that in free am- monia under Total nitrogen, including that in albuminoid ammonia . .under 5. Oxygen absorbed by organic matter within half an hour, by permanganate and acid, at 140° F. ((50° C.) under Do. in fifteen minutes, at 80° F. (27° C.) under Do. in four hours, at 80° F. (27' C.) under 6. Hardness, total under Hardness, fixed under 7. Phosphoric acid in phosphates. . Sulphuric acid in sul- / , pbates J-^"'^^'' 8. Heavy metals — Iron 9. Hydrogen sulphide, alkaline sulphides Grains per eallon, 1 in T0,OUO. 3.0000 30.0000 3.0000 0.0035 0.0070 0.3500 nil. 0.0790 w 0.0819 I - 0.C876 } 0.0700 0.0210 0.1050 12.0" 4.0° traces. 2.000 traces. nil. Centi- grammes per litre. 1 in 100. UCO. 4.2857 \ 42.8571 4.2857 \ 0.0050 j r I 0.0100 \ 0.5C00 ^ i I nil. 0.1129 0.1170 0.1252 0.1000 0.0300 I 0.1500 I 17.3° 5.7" traces. 3.0000 ] traces. nil. Microscopic characters : same as No. 1. In some usable waters, such as peat waters, the color may be yel- low or even brownish. In some also the taste may be flat or only moderately palatable. This may be much larger in waters near the sea, deep well waters, or waters from saline strata. The solids may blacken, but no nitrous fumes should be given off. This maj' be greater in deep well waters. This may be larger in upland surface waters, peat waters, etc., when the source is chiefly vegetable. The amount of nitrates varies greatly, so that an average is of doubt- ful value. The oxygen absorbed may be greater (about double) in upland sur- face waters, peat wa- ters, etc. In some waters the amount may be larger. A water such as the above will in most cases be usable, but it will be improved by filtration through a good medium. WATEE. 105 3. Suspicious Water. Character or Constituents. Physical characters : Yellow or strong green color; turbid ; suspended matter considerable ; no smell, but any marked taste. Chemical Constituents. 1. Chlorine in chlorides 2. Solids in solution : total Solids in solution : volatUe .... 3. Ammonia, free or saline Ammonia, albuminoid 4. Nitric acid (NO3), in nitrates , . Nitrous acid (NOn), in nitrites , . Nitrogen in nitrates and ni- trites Total combined nitrogen, in- cluding that in free am- 3iionia Total nitrogen, including that in albuminoid ammonia 5. Oxygen absorbed by organic matter within half an hour, by permanganate and acid, at 140= F. (80° C.) Do. in fifteen minutes, at 80° F. (27° C.) ,. Do. in four hours, at 80° F. (27° C.) 6. Hardness, total above Hardness, fixed above 7. Phosphoric acid in phos- phates ^''phat'eT """'^ '"^ ''^' \ «^^^^ 8. Heavy metals — iron 9. Hydrogen sulphide, alkaline sulphides Grains per pallon. 1 in 7(),0U0. 3 to 5 30 to 50 3 to 5 0.0035 . to 0.0070 0.0070 to 0.0087 0.35 to 0.70 0.0350 0.0870 to 0.1661 0.0871 to 0.1718 0.0879 to 0.1726 j 0.0700 1- to 0.1050 j 0.0350 to I 0.0700 j 0.1500 to \ 0.2800 12.0° 4.0° |- heavy 2.000 traces. nil. Centi- grammes per litre. 1 in 100,000. 4to7 [ 43 to 71 4 to 7 0.0050 to 0.0100 0.0100 to 0.0125 0.5 to 1.0 0500 0.1243 to 0.2373 0.1247 to 0.2455 0.1255 to 0.24G5 0.1000 to 0.1500 0.0500 to 0.1000 0.2000 to 0.4000 17.0° 5.7° traces. 3.000 ] traces, nil. Microscopic characters : Vegetable and animal forms more or less pale and colorless ; organic debris ; fibres of clothing, or other evidence of house refuse. Where the impurity is mostly vegetable, the color may be very marked in usable wa- ter. In some cases the chlo- rine may be greater. This may sometimes be larger. A water such as the above ought to excite suspicion : its use ought to be sus- pended until inquiries about it can be made ; if it must be used, it ought to be boiled and filtered. 106 PRACTICAL HYGIENE. 4. Impure Water. Character or Constituents. Physical characters : Color, yellow or brown ; turbid, and not easily purified by coarse filtration ; large amount of suspended matter ; any marked smell or taste. Chemical Constituents. Chlorine in chlorides above Solids in solution : total . .above Solids in solution: volatile, abo7ie Ammonia, free or saline, .above Ammonia, albuminoid. . . .above Nitric acid (NO3U above in nitrates J Nitrous acid (NO.), ) j^^^ m nitrites ) Nitrogen in nitrates and ni- trites above Total combined nitrcgen, in- cluding that in free am- monia above Total nitrogen, including that in albuminoid ammo- nia above Oxygen absorbed by organic matter within half an hour, by permanganate and acid, at 140 F. (60 C.^ above Do. in fifteen minutes, at 80^ F. (27^ C.) above Do. in four hours, at 80° F. (27° C.) above Hardness, total above Hardness, fixed above Phosphoric acid in phos- phates Sulphuric acid in snl- ) ^^^^.^ phates ) Heavy metals Hydrogen sulphide Alkaline sulphides Grains per gallon. 1 in 70,000. 5.0000 50.0000 5.0000 0.0070 0.0087 0.7000 0.0350 i 0.1690 0.1748 u. Centi- grammes per litre. 1 in 100,000. 1821 0.1050 0.0700 0.2800 20.0° 6.0° Very hea vy traces. 3.000 4.2857 Any ex cept iron, pres ent. 7.1428 71.4285 7.1428 0.0100 0.0125 1.0000 0.C500 0.2415 0.2497 0.2601 0.1500 0.1000 0.4000 28.5°' 8.7° Microscopic characters : Bacteria ot any liiTid ; f tin gi / nu- merous vegetable and animal forms of low types ; epi- thelia or other animal structures ; evidences of sew- age ; ova of parasites, etc. Remarks. Dark colored waters may be usable when the im- purity is vegetable. Chlorides per se are not hurtful, unless they are magnesian or in some quantity. Some waters, which are organically pure, con- tain a great excess of solids. In the absence of free ammonia, or much chlorine, this may be due to vegetable mat- ter. A water such as the above ought to be absolutely condemned. Should stress of circumstances compel its use, it ought to be well boiled and filtered ; or, better still, distilled. WATER. 107 SECTION ^t:. SrB-SECTION I. SE-iECH AFTEE WaTER. Occasionally a medical officer may be in a position in "wliicli lie has to search, for water. Few precise rules can be laid down. On a plain, the depth at which water will be found will depend on the permeability of the soil, and the dej^th at which hai'd rock or clay will hold up water. The plain should be well sui-veyed ; and if any part seems be- low the general level, a well should be sunk, or tii;ds made vriih Norton's tube-wells. The part most covered "vsith herbage is likely to have the water neai-est the surface. On a diy sandy plain, mom in g mists or swarms of insects are said sometimes to mark water below. Near the sea, water is generally found ; even close to the sea it may be fresh, if a large body of fresh Avater flowing from higher gTound hokls back the salt water. But usually wt ''■5 sunk near- the sea are brackish ; and it is necessary to sink several, passing farther and farther inland, till the point is reached where the fresh water has the predominance. Among the hills the search for water is easier. The hills store up water which mns off into plains at theu' feet. Wells should be sunk at the foot of hills, not on a spur, but, if possible, at the lowest point ; and if there are any indications of a water-course, as near there as possible. In the valleys among hills, the junction of two long valleys will, especially if there is any narrowing, generally give water. The outlet of the longest valleys should be chosen, and if there is any trace of the junction of two water-coui'ses, the well should be sunk at their imion. In a long valley with a contraction, water should be sought for on the mountain side of the con- traction. In cUgging at the side of a valley, the side with the highest hill should be chosen. Before commencing to dig, the country should be as carefully looked over as time and opportunity pei-mit, and the dip of the strata made out, if possible. A httle search will sometimes show which is the direction of fall from high gToimds or a water-shed. If moist ground only is reached, the insertion of a tube, pierced with holes, deep in the moist gTound, ^vill sometimes cause a good deal of water to be coUected. Norton's American tube-well gave satisfaction in Abyssinia, although it did not succeed so well in Ashantee. A common pump will raise the water in it if the depth be not more than 2 J: or 26 feet ; if deeper, a special force-pump has to be used. Sub-Section II. — Speclil Coxsideeations ox the Supply of Watee to SoLDIEPlS. In barracks and hospitals, and in all the usual stations, all that has to be done is to make periodical examinations of the C[uantity and cjuahty of the water, to inspect the cisterns, etc., and to consider frec|uently if in any way wells or cisterns can have been contaminated. As far as jDOSsible, a record should be kept at each station of the normal composition of the water. In transport ships, the water and the casks or tanks should always be examined before going to sea. Should it show signs of putridity, distilla- tion of sea-water, which is now easily managed, shoulcl be resorted to. If the water distils over acid, neutralize with carbonate of soda. If there 108 PRACTICAL HYGIEISTE. is a little taste from organic matter, let it be exposed to the air for two or thi'ee days. Crease's tank-filters supply an excellent means of purifying water in large quantities. The spongy ii'on ship-filter is also an excellent form of filter for the purpose, and has the further advantage of removing lead, should the water have taken any up during the process of distillation. Diu'ing marches each soldier carries a water-bottle.' He should be taught to refill it with good water whenever practicable. If the water is decidedly bad, it should be boiled with tea, and the cold tea drunk. The exhausted leaves, if well boiled in water, vnl\ give up a little more tannin and coloring matter, and will have a good eftect ; and if a soldier would do this after his evening meal, the water would be ready for the next day's mai'ch. Alum and charcoal should be used. Small charcoal or sandstone filters with elas- tic tvibes (Fig. 4) at the top, which draw water through like siphons, or thi-ough which water can be sucked, are useful, and are now much employed by officers. They have been largely used by the French soldiers in Algiers, and some were issued to our troojDS in the Ashantee campaign. It must be understood that these are all merely strainers, and do not purify the water from dissolved substances. Fio. 4. Soldiers should be taught that there is danger in drinking tiu'bid water, as they will often do when they are overcome with thirst. Not only all sorts of suspended matters may be gulped down, but even animals. On some occasions, the French army in Algiers has suffered from the men swallow- ing small leeches, which brought on dangerous bleeding. The pocket filters act fairly well in removing these suspended matters. If water-carts or water-sacks are used, they shoidd be regularly in- spected ; evei-y cart should have a straining filter of pure sand, thi-ough which the water should pass. The carts and skins should be sciiipulously clean. The water-carriers, or bheesties, in India should be paraded every morning, and the sources of water inquu-ed into. "WTien halting ground is reached, it may be necessan' to filter the water. A common plan is to carry a cask, charred inside, and pierced with smfill holes at the bottom ; it is sunk in a small stream, and the water rises through the holes. A better plan still is to have two casks, one inside the other ; the outer pierced with holes at the bottom and the inner near the top ; the space between is filled with sand, gravel, or any filtering medium that may be procurable ; the water rises through the gravel between the barrels, and flows into the inner barrel." The sand, gravel, or other ma- terial ought to be frequently turned out, cleaned, or changed. Other sim- ple jDlans are given in the di*awings, which need Httle description. Figs. ' The Italian water-bottle lias been officially adopted in oiir army, but it is doubtful if it has any advantage except its convenient shape. It certainly inijiarts an unpleas- ant taste to the water at first and presents difficulty in cleaning, trobably an jron bottle (coated by the Bower-Barff process), covered with leather, would be better. '^ In the Zulu campaign Surgeon-General Woolfryes states, that "to the large base hospitals, such as Fort Pearson and Utrecht, large single or double barrel (charcoal) filters made in Pietermaritzburg were furnished. For the troops barrel (sand) filters, made on the spot by the Royal Engineers, were provided." — A. M. D. Reports, vol. xxi., p. 287. WATER. 109 5 and 6 speak for themselves Fig. 7 is a barrel connected by a pipe with a supply above ; the water rises through sand and charcoal, and is drawn Fig. 5, FiQ. 6. Fig. 7. out above ; the barrel is fixed on a winch, and the supply pipe being re- moved, and the hole closed, a few turns of the handle clears the sand. Fig. '''-'^^-''^'''■'■^^^^ri^^^.^:,;^:^^^ Fig. 9. 8 is a simple contrivance, which may be made of wood or tin. Figs. 9 and 10 show Crease's field filter in use, either as a hand filter (Fig. 10) or con- 110 PRACTICAL HYGIENE. nectecl by an india-rubber tube to a bucket of unfiltered water placed in a cai't (Fig. 9). It acts with great rapidity and gives good results.' In the held, the medical officer may be sent on to give a report of the quantity and quality of any source. Before the troops arrive he should make his arrangements for the diiferent places of supply ; men and cattle should be watered at different points ; places should be assigned for wash- and if removal of excreta by water be attempted, the excreta should m" Fig. 10. flow in far below any possible spring ; in the case of a spring, several resei-voirs of wood should be made, and the water allowed to flow from one to another — the highest for men, the second for cattle. If it is a running stream, localities should be fixed for the special pui-pose ; that for the men's drinking water should be highest uj? the stream, for ani- mals below, washing lowest ; sen- tries should be placed as soon as fig. ii.^ possible. The distribution of water should be regulated ; streams are soon stirred up, made tm-bid, and the water becomes undrinkable for want, perhaps, of simple management. ' In the Ziilu campaign of 1879, Pnrs-pon-General Woolfrve.? reports that " Crease's filters were used in the farger field hos^pitils, but were found unsuitable for field ser- vice, as they would not stand the rough usage incidental to the march." — A. M. D. Re- ports, vol. xxi., p. 287. . -' Fig. 11 — Spongy iron filter, special hall-cock pattern. — A, cap of regulator ; P, ball-cock; C, perforated lid, covering spongy iron; C, perforated lid, covering / r>- pared sriml; C ', perforated plate, through which water flows to regulator; D, cover of filter ; F, filtered water ; G, glass ball : I, spongy iron ; L. lever of ball-cock ; O, with- drawing-pin of lever; P, tube connecting with water-supply or cistern; E, screws to fasten ball-cock to filter ; S, pyrolusite ; S', sand ; S", fine gravel (these three form the prepared sand) ; T, tap or stop-cock, from which to draw the filtered water ; U, unfil- I WATER. Ill Wherever practicable, the reservoii-s or cisterns which are made should be covered in ; even if it is merely the most flimsy covering, it is better than nothing. In sieges the same general rules must be attended to. The distribu- tion of the water should be under the care of a vigilant medical officer. Advantage should be taken of every rainfall ; fresh wells should be dug early ; if necessary, distillation of brackish or sea-water must be had re- coui'se to, tered water ; V, screw valve ; X, division in regulator, from which X A may be screwed off ; near X is the aperture through which the filtered water flows into the reserYoir F. CHAPTER 11. AIR. It might be inferred from the physiological evidence of the paramount importance of proper aeration of the blood, that the breathing of air ren- dered impure from any cause is hurtful, and that the highest degree of health is only possible when to the other conditions is added that of a proj)er supply of pure air. Experience strengthens this inference. Statisti- cal inquiries on mortality prove beyond a doubt that of the causes of death which are usually in action, impurity of the air is the most important. Indi- vidual observations confirm this. No one who has paid any attention to the condition of health, and the recovery from disease of those persons who fall under his observation, can doubt that impurity of the air marvellously affects the first, and influences, and sometimes even regulates tlie second. The average mortality in this country increases tolerably regularly with density of population. Density of population usually implies poverty and insufficient food, and unhealthy work ; but its main concomitant condition is impvirit}'^ of air fi'om overcrowding, deficiency of cleanliness, and imper- fect removal of excreta, and when this condition is removed, a very dense and jDoor population may be perfectly healthy. The same evidence of the ef- fect of pru-e and impm-e air on health and mortality is still more strikingly shown by horses ; for in that case the question is more simple, on account of the absolute similarity, in different j)ei'iods or places, of food, water, exercise, and treatment. Formerly, in the French army, the mortality among the horses was enormous. Rossignol ' states that, previous to 1836, the mortality of the French cavalry horses varied from 180 to 197 per 1,000 per annum. The enlargement of the stables, and the " increased quantity of the ration of air," reduced the loss in the next ten years to 68 per 1,000.' In 1862-66 the rate of death was reduced to 27^ per 1,000, and officers' horses (the property of the State) to 20. The admissions for lung diseases were, in 1849-52, 105, and in 1862-66, 36 ; for glanders, 1847-52, 23 ; 1862-66, 7^.^ In the Itahan war of 1859, M. Mouhn, the chief veterinary surgeon, kept 10,000 horses many months in barracks open to the external air in place of closed stables. Scarcely any horses were sick, and only one case of glanders occurred.* In the English cavalry (and in English racing stablesj the same facts are well known. Wilkinson '' informs us that the annual mortality of cavalry horses (which was formerly great) is now reduced to 20 per 1,000, ' Traits d'Hygione Militaire. Paris, 1857. ■■^ Wilkinson, Journal of the Agricultural Society, No. 50, p. 91 et seq. 3 Vital Statistics of Cavalry Horses, by T. G. Balfour, M.D., F.E.S., Surgeon-Gen- eral. Journal of the Statistical Society, June, 1880. ^Larrey : Hygiene des Hop. Mil., 1868, p. 63. ^Op. cit. AIR. 113 of which one-half is from accidents and incurable diseases. Glanders and farcy have almost disappeared, and if a case occurs, it is considered evi- dence of neglect. The food, exercise, and general treatment being the same, this result has been obtained by cleanliness, dryness, and the freest ventilation. The ventilation is threefold — ground ventilation, for drying the floors ; ceiling ventilation, for discharge of foul air ; and supply of air beneath the horses' noses, to dilute at once the products of respiration. In cow-houses and kennels similar facts ai-e v^^ell known ; disease and health are in the direct proportion of foul and pure air. The air may affect health by variations in the amount or condition of its normal constituents, by differences in physical properties, or by the presence of impurities. While the immense effect of impure air cannot be for a moment doubted, it is not always easy to assign to each impurity its definite action. The inquiry is, in fact, in its infancy ; it is difficult, and demands a more searching analysis than has been, or perhaps than can be at present, given. When impure air does not produce any very striking disease, its injurious effects may be overlooked. The evidences of injury to health from impure air are found in a larger proportion of ill health — i.e., of daj'^s lost from sickness in the year — than under other cir- cumstances ; an increase in the severity of many diseases, which, though not caused, are influenced by impure air ; and a higher rate of mortality, especially among children, whose delicate frames always give us the best test of the effect both of food and air. In many cases accurate statistical inquiries on a large scale can alone prove what may be in reality a serious depreciation of public health. The quantity of air necessary for perfect health will be considered in the chapter on Ventilation. In the present chapter the impurities will be mentioned, and then the diseases attributable to them. The following is the composition of average pure air : Composition of Atmospheric Air. Oxygen 209.6 per 1,000 volumes. Nitrogen 790.0 Carbonic acid (or carbon dioxide) 0.4 " Watery vapor Varies with temperature. Ammonia Trace. Organic matter (in vapor or suspended, ^ organized, unorganized, dead or living), | Ozone )■ Variable. Salts of sodium | Other mineral substances J The amount of oxygen is 209.8 in the pure mountain air, while in the air of towns it may fall to 209.0 or 208.7.' The mean amount of ozone is given by Levy at 1.15 milligramme per 100 cubic metres at Montsouris.^ The amount of watery vapor varies in different countries greatly, from about 30 per cent, of saturation to perfect saturation ; or, according to temperature, from 1 to 11, or even 12 grains in a cubic foot of air. Dur- ing the rains in the tropics, that amotint is not unfrequently exceeded. The best ratio for health has not been determined, but it has been sup- ' A. Smith : Air and Rain, pp. 335 et seq. ^ Annuaire for 1882. Vol. I.— 8 114 PRACTICAL HYGIENE. posed it should be from 65 to 75 per cent. ; in many healthy chmates, however, it is much more and in some much less than this. The amount of carbon dioxide in normal air ranges from .2 to .5 per thousand (or from 2 to 5 volumes in 10,000) ; it increases slightly up to 11,000 feet of elevation, then decreases ; it is augmented under certain cir- cumstances ; as in sea-air by day, though not at night ; the difference being between .54: to .33 jier thousand (Lewy). Duiiug the Arctic Expe- dition of 1875, Dr. E. L. Moss, of the Alert, fountl it to range from 0.483 to 0.641 per thousand; mean, 0.552 ' in N. Lat. 82° 27'. Fodor ■ found the L'O, at Buda-Pesth, druing the years 1877-8-9, veiy constant in cpxantity, the mean being 0.3886 per 1,000 vols. He gives the limits as 0.200 to 0.600, outside which cases occiu* very seldom, or depend upon eiTors ; the seasonal range is lowest in winter, an increase in spiing, again a diminution in summer, and the highest point is reached in autumn. There is less near the sea-shore and more in the middle of the continent ; it ajDpeai-s to increase in snow and frost, but to diminish with rain, thaw and '\\ind ; the north wind brings less C0„ with it than the south. Fodor attributes the greatest influence on the variation of C0„ in the atmosphere to its rising from the gTound air ; the C0„ being always greater at the ground level than one metre above it. Le^'J''' gives the mean C0„ at the Observatory of Moutsotu-is at 0.302 jDer 1,000 vols, in a series of five yeai's' obsei'vations. Ammonia and org-anic matter ought probably to be considered as im- purities. SECTION L IMPURITIES IX AIR. A vast number of substances, vapors, gases, or sohd particles, continu- ally pass into the atmosphere. Many of these substances can be detected neither by smell nor taste, and are inhaled without any knowledge on the part of those who breathe them. Others are smelt or tasted at first ; but in a short time, if the substance remains in the atmosphere, the nerves lose their dehcacy ; so that, in many cases, no warning, and in other in- stances, slight warning only is given by the senses of these atmospheric impimties. As if to compensate for this, a wonderful series of processes goes on ill the atmosphere, or on the earth, which keeps the air in a state of purity. Gases diffuse, and are canied away by winds, and thus become so diluted as to be innocuous ; or ai'e decomposed if compound, or are washed down by rain ; solid substances hfted into the au- by winds, or by ascensional force of evaporation, fall by their own weight ; or if organic, are oxidized into simple compounds, such as watei', cai'bon dioxide, nitric acid and ammonia ; or diy and break up into impalpable pai-ticles, which are washed down by rain. Diffusion, dilution by wmds, oxidation, and the ' Dr. B. Ninnis, of tlie Discovery, found mncli higlier amoimts, but the conditions may not have been quite the same, or some accidental error may have occurred. (See Report of the Committee on the Outbreak of Scurvy, 1877.) - Hygienische Untersucliungen iiber Luft, Boden u. Wasser, Erste Abtheilung, Die Luft. Braunschweig, 1881. For further details from this important work, see Report on Hygiene, Army i>,edical Reports, vol. xxiii. ^ Auuuaire de Aioutsouris, iyb2. AIR. ' 115 fall of rain, are the great pimfiers ; and, in addition, tliere is the wonderful laboratory of the vegetable world, which keej^s the carbon dioxide of the atmosphere within certain limits. If it were not for these counterbalan- cing agencies, the atmosj)here would soon become too impure for the human race. As it is, it is wonderful how soon the immense impiuity, which daily passes into the air, is removed, except when the perverse ingenuity of man opposes some obstacle, or makes too great a demand even upon the pimf Adng powers of Nature. The ail' passing into the lungs in the necessaiy and automatic process of respii-ation, is dra-ma successively thi'ough the mouth and nose, the fau- ces, and the aii'-tubes. It may consist, according to cu'cumstances, of matters perfectly gaseous (as in pure au'), or of a mixtui-e of gases and sohd particles, mineral or organic, which have j)assed into the atmosphere. The truly gaseous substances will doubtless enter the passages of the lungs, and will meet there T\dth that wonderful sm-face, covered with the most dehcate tufts of blood-vessels, unshielded even, it is supjDosed by some, by epithehum, which stand up on the sru-face of 5,000.000 or 6,000,000 aii'-cells, and thi-ough which the blood flows mth gTeat velocity ; there they vnB. be absorbed, and if, as has been calculated, the surface of the au'-cells is as much as from 10 to 20 square feet (and some have placed these figou'es much higher), we can well understand the ease and rapidity ^vith which gaseous substances will enter the blood. The solid particles or molecules entering with the air, may lodge in the mouth or nose, or may jDass into the lungs, and there decompose, if of destructible natui*e ; or maj dissolve or break down if of mineral f oi-mation ; or may remain as soui'ces of initation until dislodged ; or perhaps become covered over with epithehum like the particles of carbon in the miner's lung, or may pass into epithehum, and enter the body through the hTQ- phatics. If such particles lodge in. the mouth or nose they may be swallowed, and pass into the alimentary canal, and it is even more j)i'obable that this should be the case with all except the lightest and most finely divided sub- stances, than that they should pass into the lungs. x4Ithough incapable of present proof, there is some reason to think that some of the specific poisons, which float about in an impure atmosphere, such as those which arise from the typhoid or cholera evacuations, may produce their fu'st effects, not on the lungs or blood, but on the alimentaiy mucous mem- brane, with which they are brought into contact when swallowed. Sub-Section L — Suspe>t)ed ]\L\ttees. Nature of Suspended Substances. — An immense number of substances, organic and inorganic, may be suspended in the atmospliere. From the soil the winds lift sihca, finely powdered sihcate of aluminium, carbonate and phosphate of calcium, and peroxide of iron. Volcanoes throw up fine particles of carbon, sand, and dried mud, which, passing into the higher regions, may be carried over hundi'eds of miles. The animal kingdom is represented by the debris of the perished crea- tures who have hved in the atmosphere, and also it would appear that the ascensional force of evaporation will hit even animals of some magnitude from the sru'face of marsh water. From the vegetable world pass up seeds and debiis of vegetation ; pol- len, spores oi fungi, mycoderms, mucedines, which may gi-ow in the atmos- phere, and innumerable volatile substances or odors. Tne germs also of 116 PRACTICAL HYGIENE. vibrlones, bacteria, and monads are largely present, and small eggs of various kinds. From the sea the wind lifts spray, and the chloride of sodium becom- ing dried is so diffused through the atmosphere, that it is difficult, on sjDectrum analysis, to iiud a spectrum without the j'ellow Hue of soda. The works and habitations of man, however, fm-nish matters probably of much greater importance in a hygienic point of view. It is not easy at present to give a complete enumeration of aU the sub- stances, but the following are the chief facts, divided under the headings of suspended substances in the external air ; in rooms inhabited by healthy persons ; in rooms inhabited by sick persons ; in workshops and factories. Suspended Substances in External Air. 1. Duat and Sand Shoivers. — In diffei'ent parts of Eui'ope there occur from time to time showers of dust and sand. Ehrenberg ' gives the micro- scopic examination of seventy showers ; in addition to particles of sand and oxide of iron, there were numerous organic forms, which are classed by Ehrenberg imder the headings oi jjot i/gasfrica (194 forms), phytoUtharite (145 forms), polythahnia, etc. In addition there were portions of plants and fragments of insects. In a dust storm of February, 1872, in Sicily, Silvestri '' found four species of diatoms and living infusoria. These sand- storms are sometimes called monsoon showers, but it would appear that any violent storm of a cyclonic character may lift the dust from sandy wastes, as from the African deserts, and transport it great distances. It remains yet tmcertain whether all dust-storms are entirely of telluric origin ; it has been supposed that some may be derived from meteoric showers, i.e., may enter our atmosphere from the realms of space, and there has been some speculation as to whether morpliolithes of peculiar nature may not be contained in such meteoric dust showers.^ There seems no doubt that atmospheric dust may travel to great dis- tances ; the air of Berlin has evidently contained organisms derived from the African deserts, and the sails of ships 600 or 800 miles from Africa are often quite i-ed with the sand which lodges on them, 2. Independent of these sand-stonns, thei'e are numerous living crea- tures in the atmosjDhere : some lifted from the ground by winds, others gi'owing in the air. Ehrenberg has discovered at least 200 forms — rhizo- pods, tardigrades, and anguilhdce. These can be dried, and will then re- tain their vitality for months, and even years. When the external air is examined either by means of an aeroscope of some kind, or by drawing it through previously heated glass tubes, siu'- rounded by a fi-eezing mixture, many of these oi'ganisms can be found. Their number cannot be directly estimated at present. Indirectly A. Smith has endeavored to calculate the amount^ fi'om the ammonia in the air which appears to be derived from organic matter, and has supposed that there might be 529,560 germs ( = .0056 grain) in one cubic foot of the air ' Uebersiclit der seit 1847, forgesetzten Untersuchungen iiber das vou der Atmos- phere unsichtbar getragene rieche organische Leben. Berlin, 1871. '' Comptes Rendus, 1872, p. 991. ^ Dr. O. Hahn (whose observations are confirmed by D. D. F. Weiland) is said to liave discovered organisms of a coralline natnre in the interior of meteorites of the choadrite class (Daily Telegraph's Berlin Correspondent, May 13, 1882). Should this prove correct, it opens up a new and interesting field of study, especially in connection with Sir William Thomson's suggestion of the meteoric origin of life in this earth. * Air and Haiu, p. 504. I Plate V. External Air. Desckiption of Plate V. External Air. Fig. 1. Fragment of Pine-wood. V. Epidermis of Hay, with Fungus attached, 2. Linen fibres. N.B. The thick fibres crossing in lower third of plate. 3. Epithelium (nucleated) from the mouth. 4. Do. detached from the skin. 5. Cotton fibre. 6'. Feather, or Down. a. Charred vegetable particles, and mineral matter. AIR. 117 of a city. But indirect calculations of this kind are of course doubtful. The following are the most important kinds : (a) Extremely small round and oval cells, appearing in pairs or ad- hering together. The cells, described by Lemaire,' Trautman,' Bechamp, and others, ai'e exceedingly minute, and it requires a power of 600 to 1,000 diameters to see them properly. Trautman states that they gi'ow faster when sulphuretted hydrogen is in the air, and are checked by carbolic acid. Lemaire found them in immense quantities in the air of dirty prison cells, and in the sweat of the prisoners ; they will occur, however, in the open aii'. They are supposed to increase rapidly by cleavage, but their futiu*e development, if any, is uncertain ; no effect on the body has been proved to be produced by them. These bodies probably correspond to the micrococci or sphoerohacteria of Cohn. Other bacteria are also met with, such as B. termo (Microbacteria) Bacillus and vibrio (Desmobacteria), Spirillum and Spiroclxcete (SjDirobac- teria). Burdon-Sanderson's observations threv, doubt on the existence of bacteria in the air as such : D. D. Cunningham also found bacteria were rarely present (that is, recognizable) in dry atmospheric dust, but they were occasionaUy found, as well as a specimen of green spirillum ; but in the deposit from the moist air of sewers distinct bacteria were fi-equently observed. T'le truth probably is that, although they may be rarely met with in full development, this depends on the absence of proper nutriment and favorable conditions for growth, but the existence of their spores (perhaps in some cases the so-called sjyhcej^obacteria) appears to be clearly proved by the cultivation experiments of TyndalP and Fodor.'* The number of bacteria also varies with the season (Fodor,^ IMiqueP), being greatest in autumn (142) and in summer (105), less in spring (85), and least in winter (49 per metre cube). Part of this variation is due un- doubtedly to dryness, for it is obseiwed that in rainy weather they are little to be met mth, but after some days of dry weather become plentiful (Nageli, Fodor, jMiquel). Fodor' found at Buda-Pesth, in 1878-79, bacteria in 522 out of 646 observations. Drawing the air through a cultivating solution, he found numerous kinds of bacteria developed. The micrococci or sphcerobacteria were the most frequent, the sjm'obacteria tlie rarest. Desmobacteria were comparatively rare. One form of microbacterium he calls M. agile, and at- tributes to it exceptional infective power. Monads were rare. {b) Spores of fungi are not infrequent ; in the ojoen air they occur most commonly in the summer (July and August), "^ they are not in this country more frequent with one wind than another ; the largest number found by Maddox in ten houi's was 250 spores ; on some days not a spore can be found. Maddox leaves undetermined the kind of fungus which the spores developed under cultivation ; the spores were pale or olive-colored and oval, probably from some form of smut. Angus Smith found in water through which the au- of Manchester was drawn innumerable spores. Mr. ' Comptes Eendtis de I'Acad. , Oct., 1867, p. 637. '■^ Die Zersetzungsgase als TJrsache zur Weiter-verbreitung der Cholera, 1869. ^ Floating Matter in the Air in Eelation to Putrefaction and Infection, by John Tyndall, F.R.S. Longman, 1881. ■* Op cit. * Annuaire de Montsouris, 1882, pp. 406 et seq. « Maddox : Monthly Journal of the Microscopical Society, June, 1870, and Febru- ary, 1871. 118 PRACTICAL HYGIENE. • Dancer lias calculated that in a single drop of the water 250,000 fungoid spores as well as mycelium were present, but as the water Avas not ex- amined for some time there may have been growth. Mycelium of fungus seems uncommon in the air, but is sometimes found. The cells of the Protococcus jduvialis are not uncommon, and perhaps of other aJgce. Blackley ' says the amount of spores collected on a slide in four hours amounted to 30,000 or 40,000 per square inch. Dr. D. D. Cunningham' states that in the air in the subui'bs of Calcutta sj)ores are constantly present, and usually in considerable numbers. He gives a large number of beautiful drawings. Fodor^ found by cultivation that mucedines made their appearances 171 times, sarcinae 48. Bacteria and fungi seemed to alternate in seasons and years. Thus in spring bacteria were most numerous and fungi fewest, whilst the opposite was the case in autumn. Snow and rain lessened the quantity of both. (c) Parts of flowers, especially jwllen* in the spring and summer are \evy common, — cuticvdar scales, vegetable fibres and hairs, seed capsules, globular cells, etc. Near habitations are also found bits of wood often withered or burnt, bits of charcoal, starch grains, cotton and wool fibres, etc. All these substances appear fi-om Watson's experiments to be more abundant in land than sea air, as might, indeed, be expected.^ [d) Animals, or portions, such as scales from the wings of moths and butterflies ; portions of the wings of insects ; legs of spiders, bits of spi- ders' webs, and similar objects, are not uncommon ; but sometimes even living animals of some size, apparently rhizopods and amoebiform bodies. ((?) Mineral substances, fine particles of sand, clay, and chalk are gener- ally met with, even when there is no dust-storm, and are much more common when the ground is dry ; rain, indeed, appears not only to prevent these particles from being lifted, but also to precipitate those in the air. In manufacturing districts, or near a railway, there may be even large particles of metals, or pottery clay, or stone in the external air ; in the dust collected from a railway carriage near Birmingham, ]Mr. Sidebotham " found many large jjarticles of iron capable of attraction by a magnet, and being, in fact, fused particles of iron often covered with spikes and excres- cences. In towns with macadamized roads, dust and remains of horse drop- pings, finely powdered by the traffic, pass into the air, and as this is more common in dry weather, the sanitary importance of watering and washing the streets of great trafiic is manifest. Mr. Tichborne has published ' some analyses of the street dust of Dub- lin ; it contained from 29.7 per cent, of organic matter (at the top of a pillar 134 feet high) to 45.2 per cent, (in the air of a street) ; the organic matter was chiefly stable manure finely ground ; it acted as a ferment, and ' Experimental Researches on the Causes and Nature of Catarrhus ^stivus, 1873. ' Ninth Annual Report of the Sanitary Commissioner with the Government of India. ' Op. cit. * Blackley (op. cit.) shows that pollen is in large quantities, sometimes amounting to 7,870 grains per square inch of slide. In the upper strata of the air (at 400 to 500 feet) he found much more than in the lower, on an average 19 times as much. Cun- ningham (op. cit.) also found pollen in large quantity. '' Army Medical Department Report, vol. xi., p. 529 (1871). « Chemical News, October, 1871. ' Ibid., October, 1870. Description of Plate VL Accident Ward. Fig. 1'. Epidermis of Hay. 1. Do. with Fungus attached. 2. Linen fibre. 2'. Fungus filament. N.B. Long narrow filament in upper left of plate. 3. Nucleated Epithelium from the mouth. 3a. Pus cells. 4. Worn EpitheKum from the skin. 4a. Charred vegetable particles. 4c?. Fungus spores. 5. Cotton fibre. 6. Woollen fibre. 7. Fragments of Insects. 8. Pine PoUen. 9. Dried-up Pahnellaceous Fraud. 10. Ciliated spore, probably of Vaucheria. Plate VI Accident Ward. St. Mary's Hospital, London. AIR. 119 reduced nitrate of potassium into nitrite ; it had, therefore, a strong- de- oxidizing power. The plate (No. V.) drawn by Dr. J. D. Macdonald, RN., F.RS., shows some of the substances collected from the external air in the garden of St. Mary's Hospital, Paddington. ' (/) It cannot be doubted that various organic substances dried in the ground and finely pulverized, may be lifted into the air by winds, and may be carried to gTeat distances ; under the microscope the particles would probably appear formless, and could not be referred to any special class, but would be included under the term of "dust," or " amorphous matter." In this way it is believed that some diseases may be propagated ; cholera, for example, by the particles of dried excreta lifted and carried by the wind, and small-pox and scarlet fever by the disintegrated epidermis or dried discharges.^ Some of the various particles of different kinds thus suspended in the air reflect and scatter the rays of hght, and produce the appeai*ance of fine motes, which are familiar to every one, as seen in the course of a ray of light passing through a dark room, or when an electric beam is transmitted through a tube. When the air is kept motionless they subside, so that most of them have some weight, though some are so light as to float in rarefied air (Tichborne) ; when heatecl, Tyndall has shown that many of them are burnt, and a little bluish mist arising from the combustion can even be perceived ; the destructible nature proves, of course, the organic origin of those consumed, but does not show whether they are organized or not. Suspended Matters in Enclosed Spaces. 1. Booms inhabited by Healthy Persons, — In all inhabited rooms which ai"e not perfectly ventilated, the presence of scaly epithelium, single and tessellated ; round cells hke nuclei, portions of fibres (cotton, linen, wool), portions of food, bits of human hair, wood, and coal, can be found in addi- tion to the bodies which are present in the external air, though, as pointed out by Watson, mineral matters and vegetable matters are not so plentiful, as the comparative stillness of the air allows them to fall.^ In some cases articles of furniture may furnish certain substances ; the flock waU-papers, colored green by arsenical preparations (especially Scheele's green and Schweinfiirth gi-een), give off little particles of arseni- cal dust into the room ;^ and it has been shown by Professor Fleck ' that the arsenious acid in the Schweinfiirth green, when in contact wdth moist organic substances, and especially paste or size, forms arseniuretted hydro- gen,** which diffuses in the room, and is no doubt the cause of some of the cases of arsenical poisoning from green papers. 1 From Three Reports on the Sanitary Condition of St. Mary's Hospital, Taddington, by Surgeon-Major F. de Chaumont, M.D., 1875-7(3. ■■^ In the air of the back-yard of another London hospital, I found considerable quan- tities of epithelium ; and In the " dirty linen area," where the foul linen was kept in crates till washed, I found not only epithelium, but even pus globules, and also a quan- tity of fatty crystals, apparently from dressings. There were also bacteria, both free and in the zooglseal form. — [F. de C] ^ Numerous observations on the air of barracks and military hospitals have been made by medical officers of the army, especially by Drs. de Chaumont, Frank, Hewlett (of Bombay), Stanley, Baynes Reed, Venner, Watson, and many others. (See the Army Medical Department Annual Reports, from 1860-70.) ■* Halley and many others. « Zeitsch. fiir Biologic, Bd. viii., p. 445 (1872). ° Perhaps other substances are also formed, such as cyanide of kakodyle, which is intensely poisonous (Bartlett). 120 PRACTICAL HYGIErrE. Sick-Rooms. — In addition to being vitiated by respiration, the air of sick-rooms is contaminated by the abundant exhalations from the bodies, and by the effluvia from discharged excretions. The quantity of organic matter is known to be large, but it is difficult at present to give a quanti tative statement. Moscati, who (in 1818) condensed the watery vapor of a ward at Milan, describes it as being slimy, and as having a marshy smell. The peculiar smell of an hospital is indeed very remarkable, and its similarity in hospitals of different kinds seems to show that the odorous substance has a similar composition in many cases. The reaction of ozone is never given in such an atmosphere. Devergie found an " immense amount " of organic matter in the air in the A'icinity of a patient with hospital gangrene. The dust of a ward in St. Louis, in Paris, examined by Chalvet, was found in one experiment to contain 36 per cent, of organic matter, and in another 46 per cent. When burat, it gave out an odor of hom. The dust collected in hospitals for diseases of the skin is stated by Gailleton to be full of sponiles of Trichophyton. They can be found in the air of the ward when condensed by ice. Much interest was excited in 1849 by the discovery by Drs. Brittan and SwajTie, of Clifton, of bodies vei*y hke fungi in the au' of a cholera ward ; later researches lead to the opinion that this observation was perfectly con-ect, though the connection between these fungi and cholera is still quite uncertain. In 1849, also, Dr. Dundas Thomson drew the air of a cholera ward through sulphvu'ic acid ; various suspended substances were arrested, starch, woollen fibres, epithelium, /f/nyi or spores oi fungi, and vibriones. Mr. Rainy also found in the air of a cholera ward in St. Thomas' Hospital, the spores and mycelium oi. fungi and bacteria. Some of these bodies were found, however, in the open air. In hospitals for skin diseases Achorion has been detected in the air where there are patients with/ai7<.s'; and Tilbury Fox' has figured the spores (clustered and in chains), and the myceHum of Trichophyton in a ward with a number of children with tinea circinata. In a w^ard in Netley Hospital (under Bingade-Surgeon Veale, A.M.D.), where repeated cases of erysipelas occurred, the air was found to be loaded vnth fungi. The ward being emptied, and the fioor, walls, and ceiling be- ing washed with cai'bolic acid, the disease ceased. The scaly and smaU round epithelia found in most rooms are in large quantity in hospital wards ; and probably in cases where there is much exj)ectoration or exposui'e of pus or puriform fluids to the air, the quan- tity would be still larger. Considering that the pleuro-pneumonia of cattle is probably propa- gated thi'ough the pus and epithelium cells of the sputa passing into the au'-cells of other cattle ; that even in man there is evidence of a pneu- monic or phthisical disease being contagious,'^ the floating of these cells in the air is worthy of all attention. It may explain some of those curious instances of phthisis being apparently commvmicated. In the air of a phthisical ward at Netley, Dr. Watson not only found pus-cells, but bodies which were not found in the external air or in the rooms of healthy per- sons, and which were very like the cells seen in tuberculous matter. In military granular conjunctivitis (gray granulations), the remarkable effect of ventilation in arresting the spread (Stromeyer) seems to show that we ' Lancet, Jaimary, 1872. * Brjsou, Cases iu the Mediterranean Fleet. AIR. 121 have here a similar case, and that ventilation acts by diluting, oxidizing, and drying the cells thrown off from the conjunctivse. In small-pox wards, BakeweU has found unequivocal evidence of minute scales of small-pox. matter in the aii'. It seems pirobable that the discovery of suspended mat- ters of this kind will lead to most important results. ' The possibility of a dii'ect transference from body to bod}^ of cells undergoing sj^ecial chemical or vital changes is thus placed beyond doubt, and the doctrine of con- tagion receives an additional elucidation. It is now generally admitted that protophytes like Frotococcus 2?IuviaUs, may be dried, and yet retain their vitality even for years, and may be blown about in atmospheric cur- rents ; and should contagion be proved to depend upon minute organisms these might easily be carried about in a similar way, either alone or carried by epithelium or other particles thro\^-n off from the bodies of patients. The success which has sometimes attended the treatment of pleuro-pneumonia in cattle by means of carbolic acid (Crookes), and the apparent advantage of inhaling disinfectants in human phthisis, seem to point to a similar active cause in those maladies ; and this appears in some sort confirmed by the observation of Koch on the supposed bacillus of phthisis. 3. Workshops, Factories, and Mines. — Grinding of steel and iron, and stones ; making metallic and pearl buttons ; melting zinc ; melting solder; carding and spinning textile fabrics of all kinds ; grinding paint ; making cement, and in fact almost innumerable trades cause more or less dust, derived from the fabrics and materials, to pass into the air. Dr. Sigerson ^ found a black dust composed of carbon, iron (in the shape of small jagged pieces and also as hollow balls -giyVir of an inch in diameter), and ash, in metal shops. In the air of a printing-office there was enough antimony to be chemically detected. In the air of stables were equine hairs, epithelium, moth-cells, ovules, and various fungi. In addition to these suspended matters, which vary with the kind of work, the air of workshops is largely contaminated by respiration and by the combustion of gas. In mines the suspended matters are made up of the particles of the particiolar substance which is being worked, or of rock excavated to obtain metals, of sooty matters fi'om lamps and candles, and of substances de- rived from blasting. Sub-Section IE. — Gaseous Substances. A great number of gases may pass into the atmosphere either from natural causes or from the works of man. Compounds of Carbon. — Carbon dioxide (abnormal if exceeding 5 in 10,000 parts), carbon monoxide, carburetted hydrogen or methane, and peculiar substances (gaseous) in sewer air. Compounds of Sulphur. — Sulphur dioxide, sulphuric acid, hydrogen sulphide, ammonium sulphide, and carbon disulphide. Compounds of Chlorine. — Hydrochloric acid from alkali works. Compounds of Nitrogen. — Ammonia and ammonium acetate, sulphide, * In the accident vra,ri of St. Mary's Hospital, Paddington, I found pus-cells in the air, near some beds which had a bad reputation for erysipelas. See plate dra-\vn by Dr. Macdonald (Report on St. Mary's, op. cit.V— [F. de C.] '^ British Medical Journal, June, 1870, from Memoirs of the Irish Academy, in which publication are some excellent observations by the same writer. 122 PEACTICAL HYGIENE. and carbonate (normal in small amount ?), and nitrous and nitric acids. Compounds of Phosphorus.— Hydrogen phosphide. Organic VajMi^'^. — Of the exact composition of the vapors, often fetid, ■which arise from various decomj)osing animal matters, little is known. Sub-Section HI. — Nature of Impubities in certain Special Cases. Air Vitiated by Respiration. An adult man, in a state of repose, gives off in twenty-four hours from 12 to 16 cubic feet or more, according to weight, of carbon dioxide, the most of it from the lungs, although he also emits an undetermined quantity by the skin. On an avei-age, an adult man, not doing excessive work, may be considered to give to the atmosphere every hour not less than .6 cubic foot of carbonic acid. Pettenkofer states the amount at about O.7.' Women give off less, and children and old people also give oft" a smaller amount. The amount of carbonic acid in pure air being assumed to be on an average 0.4 per 1,000, or four volumes j^er 10,000, the quantity in the air of the rooms vitiated by respiration varies mthiu wide limits, and many analyses will be found in books. The following table is a part of the numerous experiments on barrack-rooms by Dr. de Chaumont on this point, and is especially valuable, because the amount of CO., in the ex- ternal air was simultaneously determined. The analyses wxre made at night, when the men were in the rooms. The cubic space per head was 600 feet in the barracks and from 1,200 to 1,600 in the hospitals. The last column of the table shows the condition of the ventilation as measui-ed by the CO^ ; it is very satisfactory in the new ban-acks (Gosport and Chelsea), but is much less so in the old barracks and casemates. The Herbert and Hilsea mihtaiy hospitals show excellent ventilation, while the old-fashioned Portsmouth gamson hospital is in this respect very bad. The l^rison-cells show, in all cases, a very high degree of respiratory impurity, and this must be one of the depressing influences of long cell confinement. WUson ^ gives some important information on this point. In cells (in Portsmouth Con\ict Prison) of 614 cubic feet, always occupied, he found the C0„ = 0.720 per 1,000 ; the prisoners were healthy and had a good color. In cells of 210 cubic feet, occupied only at night by prisoners employed out- side dm-ing the day, he found 1.044 per 1,000 of C0„ ; the occupants were all pale and anaemic. The carbonic acid of respiration is equally diffused through the air of a room (Lassaigne, Pettenkofer, Eoscoe) ; it is very rapidly got rid of by opening windows, and in this respect differs from the organic matter, and probably from the watery vapor ; neither appears to diffuse rapidly or equably through a room. This is the quantity adopted by Roth and Lex (Militar-Gesundheitspflege). Handbook of Hygiene. AIR. 123 Amount of Carbon Dioxide in 1,000 Volumes of Air (de Chaumont). Barracks. Gosport New Barracks Anglesey Barracks Aldershot Chelsea Tower of London ' Fort Elson tCasemate) Fort Brockhurst (Casemate) Military axd Civil Hospitals. Portsmouth Garrison Hospital Portsmnuth Civil infirmary Herbert Hospital Hilsea Hospital St. Mary's, Paddington , Military and Civil Prisons. Aldershot MUitary Prison — Cells Gosport Military Prison — Cells Chatham Convict Prison — Cells Pentonville Prison — Cells — Jebb's system CO2 in External Air. .430 .398 .440 .470 .420 .425 .422 .306 .322 .424 .405 .560 .409 .555 .452 .420' CO2 in Room. Largest Amount found. 1.846 1.971 1.408 1.175 1.731 1.874 1.027 2.057 1.309 .730 .741 1.534 3.484 2.344 3.097 1.926 Mean Amount. .645 1.404 .976 .718 1.338 1.209 .838 .976 .928 .472 .578 .847 1.051 1.335 1.691 .989 Mean Respiratory Impurity. .215 1.011 .536 .248 .898 .784 .416 .670 .606 .048 .173 .287 1.242 .780 1.239 .569 The amount of C0„ is often much greater than in the above instances. In a boys' school with 67 boys, and 4,640 cubic feet ( = 69 cubic feet per head), Koscoe found 3.1 parts of CO, per 1,000. In Leicester, in a room with six persons, and only 51 cubic feet of space per head, and with three gas-Ughts burning, Mr. Weaver ^ found the CO^ to be 5.28 parts per 1,000 ; while, in a girls' school-room (70 girls, and 10,400 cubic feet), or 150 cubic feet per head, Pettenkofer found no less than 7.230 parts per 1,000. In many schools, work-rooms, and factories, the amount of respiratory impurity must be as great as this, and doubtless a constant unfavorable effect is pro- duced on health. Dr. Hajne (in H.M. ship Doris) found the CO^ to range from 1.03 to 3.21 between decks, the latter quantity being in the ward- room with the scuttles in.' In the Ai-ctic Expedition of 1875-76, Dr. Moss found as much as 4.82 in the ward-room of the Alert, "room feeUng very close ;" and Dr. Ninuis found 5.57 in the lower deck of the Discovery. Gartner^ found in the armored corvette Jackson, about 1.0 between decks, as much as 6.42 in the sick-bay, 5.54 in the cells, and no less than 60 in the powder magazines.^ In a horse stable at the Ecole IMilitaire, the amount was 7 per 1,000. At Hilsea, with a cubic space of 655 cubic feet per horse, the amount was 1.053 ; ' Assumed at .420. ^ Mr Weaver gives several good analyses in different public and private rooms in Leicester. Lancet, July and August, 1872. ^ Med. Chir. Trans.," vol. Ivii. * Deutsche Vierteliahrschrift fiir Offentliche Gesundheitspflege, Bd. xiii., p. 369, 1881. 124 PRACTICAL HYGIENE. and in another stable, -with 1,000 cubic feet per horse, only .593 per 1,000 (de Chaumont). Miircker found 8.5 in a stable in Gottingen, and no less than 17.07 in a b^Te. By the skin and lungs pass off from 25 to 40 ounces of -water in twenty- four hoiu^, to maintain which, in a state of vapor, 211 cubic feet of aii- per hour are necessaiy on an average. Of course, however, temperature and the hygrometric condition of the air greatly modify this. Organic matter is also given off from the skin and lungs, the amount of which has never been precisely determined. Xor is it possible, at pi'esent, to estimate it correctly. This organic matter must be partly suspended, and is made up of small pai-ticles of epitheliiun and fatty matters detached from the skin and mouth, and j^artly of an organic vapor given off from the lungs and mouth. The organic matter from the lungs, when drawn thi'ough sulj^huiic acid, dai'kens it ; thi'ough j)ermanganate of potash, decoloiizes it ; and through pure water, renders it offensive. Collected from the aii' by con- densing the watery vapor on the sides of a globe containing ice (as by Tad- dei in the wards of the Santa Maria Novella), it is found to be precipitated by nitrate of silver, to decoloiize potassium permanganate, to blacken on platinum, and to yield ammonia. It is therefore nitrogenous and oxidizable. It has a very fetid smell, and this is retained in a room for so long a time, sometimes for foiu- houi-s, even when there is free ventilation, as to show that it is oxidized slowly. It is probably in combination with water, for the most hygroscopic substances absorb most of it. It is absorbed most by wool, feathers, damp walls, and moist paper, and least by straw and horse- hair. The color of the substance influences its absorption in the following order : black most, then blue, yellow, and white. It is probably not a gas, but is molecular, and floats in clouds through the air, as the odor is evi- dently not always equally ditfiised thi-ough a room. In a room, the aii" of which is at first perfectly pui*e, but is "\itiated by respiration, the smell of organic matter is generally perceptible when the C0„ reaches .7 per 1,000 volumes, and is \erx strong when the CO, amounts to 1 per 1,000.' From experiments made at Gravesend, Xetley, Aldershot, and Hilsea, by various medical ofiicers,' it has been shown that the amount of potassium perman- ganate destroyed by aii' drawn through its solution is generally in propor- tion to the amoimt of CO, of respii'ation. "VMien the air of inhabited rooms is drawn tkrough pure water, and the free ammonia got rid of, distillation with alkahne permanganate, in the method of "Wanklyn, gives a perceptible quantity of "albuminoid ammonia." In a bedroom at 9 p.m., A. Smith ' fotmd .1901 milligramme in 1 cubic metre of ail* ; at 7 a.m., there were .3316 milligramme in each cubic metre. The average of eight observations in the external air (at Portsmouth) gave 0.0935 of free NH,, and 0.0886 of albuminoid NH^ in milhgrammes per cubic metre. In the Portsmouth General Hospital the fi-ee NHj was as high as 0.855, and the albuminoid 1.307.^ The following is from Dr. de Chaumont's Eeports on the Ventilation Experiments at St. Maiy's Hospital, Paddington : ' On this point see table at pace 159. " See note, p. 119. ^ Air and Rain, p. 430. — If expressed as grammes per million cubic meters, the amount is 190.114 and 384.601 ; in grains, in one million cubic feet, the numbers are 83.074 and 14G.210. •* Moss, Lancet, November, 1872. AIR. 125 MUligrammes per Cubic Metre. External air, July, 1875 Wards Do. Do External air, August, 1876 .. . Wards Do Do Do Do Total Free NH3. Albuminoid Organic Oxygen for NH3. Oxygen. oxidizable matter. 0.3574 0.5280 1.4300 0.6680 0.4710 1.4900 0.6669 0.6770 1.5100 0.3519 0.6915 .... 1.3600 0.0163 0.5206 0.4444 0.5714 0.0497 0.4622 0.3747 0.5621 nil. 0.2824 0.2571 0.5142 0.0310 0.3576 0.3101 0.3567 0.0127 0.5259 0.2225 0.4451 0.0100 0.3684 0.4420 0.6315 j Air damp and still, ( wind S.W., slight. Air dry and warm, wind S. E. by E. , fresh. It is evident that tlie condition of the external air, with regard to move- ment and humidity, has a great deal to do with the amount of organic matter. The nitrogen acids are also met with ; in one instance, in the above experiments, they reached in a ward 28.484 per metre, of which 0.7392 was nitrous, and the rest nitric acid. Air vitiated by Combustion. The products of firing pass out into the atmosphere at large ; those of lighting are for the most part allowed to diffuse in the room. Goal of average quahty gives off in combustion : 1. Carbon. — About 1 per cent, of the coal is given off as fine carbon and tany particles. 2. Carbon dioxide. — In Manchester, Angus Smith calculated some years ago that 15,000 tons of carbon dioxide were daily thrown out, and the quantity must now be stUl larger. In London over 30,000 tons of coal a day ai-e consumed, and this would yield nearly 90,000 tons of carbon di- oxide. 3. Carbon inonoxide. — The amount depends on the perfection of com- bustion. 4 Sulphur, sulphur dioxide, and sulphuric acid. — The amount of sul- phui' in coal varies from ^ to 6 or 7 per cent. In the air of Manchester, A. Smith found 1 grain of sulphuric acid in 2,000 and 1,076 cubic feet. 5. Carbon disulphide. 6. Ammonium sulphide or carbonate. 7. Hydrogen sulphide (sometimes). 8. Water. From some manufactories there poixr out much greater quantities of SO,, (coj)]Der works), arsenical fumes, hydrogen sulphide, carbon dioxide, etc. For complete combustion 1 Bb of coal demands about 240 cubic feet of air. Wood produces carbon dioxide and monoxide and water in large quan- tity, but few compounds of sulphur. 1 ft) of dried wood demands about 120 cubic feet of air for complete combustion. 126 PRACTICAL HYGIENE. Coal-gas, when fairly purified, is composed of — Hydrogen 40 to 45.58 Marsh gas (Hght carburetted hydrogen) 35 to 40 Carbon monoxide 3 to 6.6 Oletiaut gas (ethylene or ethene) 3 to 4 Acetylene (or ethiae) 2 to 3 Hydrogen sulphide 0.29 to 1 Kitrogen 2 to 2.5 Carbon dioxide 3 to 3.75 Srdphur dioxide ) 5 to 1 Am monia or ammonium sulphide >■ (or ia the best cannel- Carbou disvdphide ) coal gas only traces). In some analyses the carbon monoxide has been as high as 11 per cent., and the light cai'buretted hydrogen 56 ; in such cases the amount of hydro- gen is small. As much as 60 gi-ains of sulphur have been found in 100 cubic feet of gas.' The parliamentaiy maximum is 20 grains in 100 cubic feet. In badl}' purified gas there may be a gi-eat number of substances in small amount, especially hydrocarbons and alcohols, such as propylene, butylene, amylene, benzole, xylol, some of the nitrogenous oily bases, such as pyiTol, picoline, etc.'' \Mien the gas is partly burnt, the hydrogen and light and heavj- car- buretted hydrogens are almost destroyed; nitrogen (67 per cent.), water (16i)er cent.), carbon dioxide (7 per cent), and carbon monoxide (5 to 6 per cent.), A\-ith sulphur dioxide and ammonia, being the principal result- ants. And these products escape usually into the ah' of rooms. With perfect combustion there will be little carbon monoxide. According to the quality of the gas, 1 cubic foot of gas wiU imite with from .9 to 1.64 cubic foot of oxygen, and produces on an average 2 cubic feet of carbon dioxide, and from .2 to .5 grain of sulphm- dioxide. In other words, 1 cubic foot of gas will destroy the entire oxygen of about 8 cubic feet of ah". One cubic foot of gas will raise the temperature of 31,290 cubic feet of air 1° Fahr. 0(7. — A lamp with a moderately good wick burns about 154 grains of oil per hour, consumes the oxygen of about 3.2 cubic feet of air, and pro- duces a little more than ^ a cubic foot of cai'bon dioxide ; 1 ft of oil de- mands fi'om 140 to 160 cubic feet of air for comi^lete combustion. A candle of 6 to the ft biu-ns per hour about 170 gi-ains. The products of the combustion of coal and wood pass into the atmos- phere, and usually are at once largely diluted. Diffusion and the ever- moring air rapidly purify the atmosphere from carbon dioxide. It is not so, however, with the suspended carbon and tany matters, which are too hea^7 to drift far, or to ascend high. As a rule, the par- ticles of carbon are not foimd higher than 600 feet ; and the way it accu- mulates in the lower strata of the atmosphere can be seen by looking at any lofty building in London. The air of London is so loaded with car- bon, that even when there is no fog, particles can be collected on Pou- chefs aeroscope when only a very small quantity of air is dl•a'^^^l through. It is apparently chiefly from combustion, and in some cases from chemical works, that the au- of towns contains so much acid as to make ' Chemical News, March, 186.5, p. 154 ■^ For a further list of these suhstances, which do not appear very important, see Pappeuheim's Handbuch der San. Pol., Band iii., Supp., p. 261. AIE. 127 rain water acid. In Manchester, in 1868, Angus Smith found the rains to contain from 5.6 grains to 1.4 grain of sulphuric acid (free and combined), and from 1.277 to .0287 grain of hj^drochloric acid per gallon. In Liver- pool and Newcastle air the same thing occurs ; the sulphuric acid is always larger in amount than the hydrochloric. Salphui'ous and sulphuric acids also appear to be less rapidly removed, as Angus Smith found a perceptible quantity in the air of Manchester ; and the rain water is often made acid from this cause. The products of gas combustion are for the most part allowed to escape into rooms, but certainly this should not be allowed, when gas is burnt in the large quantities commonly used. The immense quantity of gas often used causes great heat, humidity of the air, and there is also some sulphur dioxide, an excess of carbon dioxide, and, probably, a little carbon monoxide, to which some of the effects may be due. Weaver ' found as much as 5.32 volumes of carbon dioxide per 1,000 in the room of a frame- work knitter in Leicester, with 14 gas lights burning. In other work-rooms the amounts were 5.28, 4.6, down to 2.11 volumes per 1,000. This amount has a very injurious effect on health, as shown long ago by Dr. Guy. In a workshop in Paris, with 400 men and 400 gas-burners, the health of the men was very bad. General Morin introduced good venti- lation, and the number of cases of illness was reduced one-third. The appetite of the men, formerly very bad, gTcatly improved. According to Dr. Zock,'' coal-gas gives off rather more carbon dioxide for an equal illuminating power than oil, but less than petroleum. Dr. Odling found for equal illuminating power, that candles gave more impurity to the air than gas.^ Gas gives out, however, more water. In tobacco smoke are contained particles of nicotine or its salts (Heubel), and probably of picoline bases. There is also much carbon dioxide, ammonia, and butyric acid. Dr. Eipley Nichols has investigated the air in smoking cars on American railways, and found the C0„ to range from 0.98 to 3.35 per 1,000, with a mean of 2.278 : in ordinary non-smoking cars the CO^ varied from 1.74 to 3.67, with a mean of 2.32, so that there was not much differ- ence as far as CO.^ went. As regards ammonia, however, the difference was great, for (taking the external air ratio as 100) he found in the smoking car from 310 to 575, whilst in the ordinary cars it was only 135 to 175. None of the peculiar products of the combustion of tobacco were found.^ Air vitiated by Effluvia from Sewage Matter and Air of Sewers. Air of Cesspools. — The air of cesspools, and especially of the cemented pits which are still common in many continental towns, and which receive little beyond the solid and liquid excreta and some of the house water, is generally highly impure. Levy ^ refers to an extreme case, in which the oxygen was lessened to 2 per cent., the nitrogen being 94 and the CO^, 4. In this case apparently no other gases were present ; but in most instances there is a variable amount of hydrogen sulphide", ammonium sulphide, nitrogen, carbon dioxide, and carburetted hydrogen, in addition to fetid ' Lancet, July, 1872. 2 Zeitsch. fur Biol., Band ii., p. 117 (1866). ^ Medical Times and Gazette, January 9, 1869. * Reprint from the Sixth Annual Report of the Massachusetts Board of Health. ^ Traite d'Hygiene, 3d edit , p. 636. * Barker, On Malaria and Miasmata, p. 245. 128 PRACTICAL HYGIENE. organic matters. These organic matters are in large amount ; 62 feet of the air of a cesspool destroyed, in Angus Smith's experiments, as much potas- sium permanganate as 176,000 cubic feet of pure air, though perhaps some hydrogen sulphide may have been also present. Oesterlen' states that these gases will pass easily through walls ; and M. Hennezel " noticed that in the "fosses d'aisances" in Paris, even in those covered with stone slabs and earth, the wind blowing down the ventilating tube will force the gas through the neighboring walls, and then perhaps into the house. The Air of Sewers.— In sewers the products of decomposition are varia- ble, as not only solid and liquid excreta and house water, but the washings and debris of the streets, the refuse of trades, etc., pass into the sewers. As a rule, the products of decomposition of the sewer water appear to be much the same as noted above — viz., fetid organic matters, carbo-ammoni- acal substances condensing with the water of the au* on the cold walls, carbon dioxide, nitrogen, and hydi-ogen sulphide.^ The proportions of these gases are variable ; * the most common are carbon dioxide and nitrogen ; marsh gas is found when oxidation is impeded, and hydrogen sulphide and ammonium sulphide, which form in the sewer water in most cases, are liberated from time to time. The gases, however, are, as a rule, of far less importance then the fetid organic matters, the exact nature of which it would be most desirable to examine more thoroughly. The organic vaj)or is carbo-ammoniacal ; the j^utrid substance in the sewer water appears, from Odhng's observations, to be allied to the com- pound ammonias ; it contains more carbon than methylamine (NH2(CH3) ), and less than ethylamine (NH.,(C„HJ ). The composition of sewer air will, of course, vary infinitely with the amount of gases disengaged and the degree of ventilation in the sewer. The quantity of oxygen is sometimes in normal amount ; it may, however, be diminished in very badly constructed sewers. Parent-Duchatelet gave an analysis of the air of a choked sewer in Paris, which contained only 13.79 per cent, of oxygen,^ and no less than 2.99 per cent, of hydi-ogen sulphide. Excluding this analysis, the greatest impurity in the old Parisian sewers, as determined by Gaultier de Claubry, in 19 analyses " in 1829, was 3.4 per cent, of carbon dioxide and 1.25 per cent, of hydrogen sulphide (in different samples of air). The lowest amount of oxygen was 17.4 per cent. Hydi-ogen sulphide was present in 18 out of 19 cases ; the mean of whole 19 cases being .81 jjer cent. The mean amount of CO^ in 19 cases was 2.3 per cent In the present London sewers of good con- struction the air is much less impure. Dr. Letheby found only .532 per cent, of C0„, a good deal of ammonia, and only traces of hydrogen sulphide and marsh gas. Dr. Miller's experiments in 1867 ' gave a mean of only 0.106 per cent, of CO.^ in 18 analyses, and .307 per cent, in 6 other instances, the oxygen 20.71 per cent. No hydrogen sulphide was present. Dr. Eussell examined the aii- in the sewers of Paddington in August ; the ' Oesterlen, Hysriene, 1857, p. 445. 2 Ann. d'Hygiene, Oct., 1868, p. 178. ^ Oesterlen, Handb. der Hyg., 2d edition, p. 445. ■* Dr. Letheby's experiments, as given in his official Report, in liis article in the Encyclopaedia Britannica, 8th edition (Sanitary Science), etc. , and in a letter to Dr. Adams (given by Dr. Adams in his pamphlet, The Sanitary Aspect of the Sewage Question, 18(38, p. 84), are the most complete on this subject. * Hygiene publ., t. i., p. 209, foot-note, and p. 390. * Parent-Duchi'.telet's Hyg. publique, t. i., p. 389. ' Abstract in Chemical News, March, 1868. AIE. 129 most impure air contained 20.7 oxygen, 78.798 nitrogen, and .51 volume of C0„ per cent. ; there was very little ammonia, and no hydrogen sulphide. It is evident that, if we take the carbon dioxide and hydrogen sulphide as indices, sewer aii" has no constant composition. It is sometimes almost as pure as the outside air, while at other times it may be highly impure. But these gases are probably the least important ingTedients of sewer air ; that organic matters are present is evident from the pecuHar fetid smell, and in some cases they are in large amount ; 8,000 cubic feet of the air of a house into which sewer air had penetrated destroyed more than 20 times as much potassium permanganate as the same quantity of pure air (Angus Smith). Fungi grow rapidly in such aii", and meat and milk soon taint when exposed to it. When the sewer air passes through charcoal these substances are absorbed ; they may be j^artly oxidized, as Dr. Miller found some nitric acid in the charcoal, but they also collect in the charcoal and can be recovered (in part at any rate) from it by distillation.' We must also suppose, for facts leave us no other explanation, that the unknown agencies which produce typhoid fever may also be present, and there can be httle doubt that cholera " may occasionally spread in the same way. The poison of yellow fever (as appears hkely from the epidemic in Madrid) may also exist in sewer air. Whether smaU-pox, scarlet fever, etc., can own a similar channel of distribution is uncertain, although they are no doubt aggravated by it ; that dysentery and diarrhoea may also be caused by exhalations proceeding from a fotil sewer we cannot doubt, but the precise agency is here also unknown. The experiments of Professor Frankland^ show that solid or liquid matter is not likely to be scattered into the air from the sewage itself by any agitation it is likely to undergo, until gas begins to be generated in it. He found that no ordinary agitation (even greater than sewer water is likely to meet with) would scatter particles of Hthia solution into the air, but that the biu'sting of bubbles of carbon dioxide was sufficient to effect it. Hence he argues (with apparent truth) that sewage becomes danger- ous in this way only after the setting in of decomposition, so that if we take proper steps to carry away sewage at once the danger becomes re- duced to a minimum. Dr. D. D. Cunningham found large quantities of bacteria in the air of the Calcutta sewers. Air of Churchyards and Vaults. The decomposition of bodies gives rise to a very large amount of car- bon dioxide. It has been calculated that when intramural burial was carried on in London, 2|- millions of cubic feet of C0„ were disengaged annually from the 52,000 bodies then buried. Ammonia and an ofi^ensive putrid vapor are also given off. The air of most cemeteries is richer in CO^ (.7 to .9 per 1,000, Eamon da Luna), and the organic matter is per- ceptibly large when tested by potassium permanganate. In vaults, the air contains much CO^, carbonate or sulphide of ammonium, nitrogen, hy- drogen sulphide, and organic matter (Pellieux). Waller Lewes foimd ht- tle SH^ or CH, ; or cyanogen, or hydrogen phosphide. In his experi- ments the gas always extinguished flame. Fungi and germs of infusoria abound. » Miller, Chemical Ne'n'S, March, 1868. 2 A case in which sewers probably played a part in the dissemination of cholera is given in Dr. Parkes' Report on the Cholera in Southampton in 1806 to the Medical Officer of the Privy Council. ^ Proceedings of the Royal Society, 1877. Vol. L— 9 130 PRACTICAL HYGIENE. Air vitiated by certain Trades. Hydrochloric acid gas, from alkali works. Sulphur dioxide and sulphm-ic acid, from copper works — bleaching. Hydrogen sulphide, from several chemical works, especially of am- monia. Carbon dioxide, carbonic monoxide, and hydrogen sulphide, from brick fields and cement^works. Carbon monoxide (in addition to above cases), from iron furnaces, gives rise to from 22 to 25 per cent. (Letheby) ; from copper furnaces, 15 to 19 per cent. (Letheby). Organic vapors, from glue refiners, bone-bum ers, slaughter-houses, knackeries. Zinc fumes (oxide of zinc), from brass-founders. Arsenical fumes, from copper-smelting. Phosphoric fumes, from manufacture of matches. Carbon disulphide, from some india-rubber works. Air of Towns. The air of towns may be vitiated by respiration, combustion, effluvia from the soil, sewers, and trades. The movement of the air tends, how- ever, to continually dilute and remove these impurities, and the heavier particles deposit, so that the air even of manufacturing towns is purer than might have been anticipated. The amount of oxygen in the atmos- phere in the purest air near the surface of the earth, being taken as from 20.9 to 20.99 volumes percent., and the carbon dioxide being from .03 to .045 per cent., with a mean of .04, it would appear, from Angus Smith's observations,' that in a crowded part of Manchester, exposed to smoke, the amount of oxygen was from 20.868 to 20.179 per cent. ; the average of the street air taken from the laboratory front door was, in Manchester, 20.943 ; of the closet, a midden behind the laboratory, 20.70. Li the London air, in the open spaces, the oxygen amounted to 20.95 ; in the crowded east- ern districts to 20.857.'^ In a foggy frost, in Manchester, when the smoke was not moving much, the amount was 20.91. In Glasgow the average was 20.9092. The variations are, therefore, within nan-ow hmits. The percentage lessening of oxygen in atmospheiic air is partly made up by an increase in the carbon dioxide ; but if a town is well built, the increase is trifling ; the mean amovmt of CO^ for London, in Roscoe's ex- periments, was only .037 volume per cent. ; in Manchester, in usual weather, A. Smith found the amount .0403 per cent. ; during fogs, .0679 ; in the air above the middens, .0774 per cent. It is stated that there is a difference between close and open spaces in towns ; thus, in the open spaces (parks) in London, the mean amount in A. Smith's experiments was .0301 per cent. ; in Newgate Street (in the City), it was .0413 ; in Lower Thames Street (City), .0428 per cent. It is not, however, stated whether the observations were made simultaneously.^ In Glasgow, the average ' Air and Rain, p. 24. ^ A. Smith, op. cit., p. 30. 3 In the neigliborhood of St. Mary's Hospital, Paddington, i tound the mean CO^ to be 0.056 per cent, in damp still weather, July, lb75 ; the same locality in dry, hot weather, with a good deal of movement of air, 0.0416 per cent. (August, 1876) ; in the neighborhood of University College Hospital, damp weather, 0.0786 per cent, in Feb- ruary, 1877.— [F. de C] AIE. 131 CO, was .0502, and in Perth .04136 per cent.' In foreign cities the amount is greater, and surpasses the normal limit in air. In Madrid, Eamon da Luna found .0517 as a mean average, and in some cases .08 per cent. ; in Munich, the amount is .05 per cent. These numbers seem, after all, insignificant, but they are not really so, as the aggregate difference, if only .01 per cent., is considerable. In the air of towns which burn coal the» are also, as noted, an excess of acidity (sulphuric and hydrochloric acids), and various suspended matters, which no doubt have injurious effects.'' The air of most towns, in addition to ammonia, also contains a nitroge- nous substance which, when condensed in pure water, can be made to yield albuminoid ammonia, by Wanklyn's method. In various places in London, A. Smith^ found the amount to average .509 milligramme of albuminoid ammonia in 1 cubic metre. The greatest amount was in a field two miles past Clapham Junction .(viz., .27108 miUigramme per cubic metre), and the least was in Westminster Abbey Yard (.08555 milligTamme). At the shore at Innellan (Fu-th of Clyde), the amount was .1378 milhgramme, and the mean in the streets of Glasgow was .3049 milligramme per cubic metre. In the air of the Underground Railway, in London, the amount was .3734 milligramme.* The mean of INIr. Moss's experiments in the open air of Portsmouth was rather less, viz., .0886 milligramme of albuminoid ammonia per cubic metre. This ammonia may be derived from the li\T.ng beings in the air, or from dead organic matter ; and to bring out the full meaning of such researches, the chemical must be supplemented by a microscopical examination. Ozone is genei-ally absent in town au', but Marie-Davy found at Montsouris an average of .0115 milligramme per cubic metre. '^ This, however, depends very much upon the situation of the observatory and the direction of the prevailing winds. The wind blowing from the open coun- try is richer in ozone than that coming from the town. " These observations prove how important it is to build towns in such a way as to insure good perflation and movement of air everywhere, and to provide open spaces in all the densely crowded parts. The great powers of nature, winds, and the fall of rain, will then, for the most part, keep the atmospheric impurities within hmits not injurious to health. Air of Marshes. The air of typical marshes contains usually an excess of carbon diox- ide, which amounts, perhaps, to .6 or .8 or more per 1,000 volumes. Watery vapor is usually in large quantity. Hydrogen sulphide is present, if the water of the marsh contains sulphates, which, in presence of organic matter, are converted into sulphides, from which SH„ is derived by the action of vegetable acids. Marsh gas is also often present, and occasionally free hydrogen and ammonia, and, it is said, hydrogen phosphide.' * A. Smith, Air and Rain, p. 50 et seq. ' There ar6 also nitrous and nitric acids, due probably to the oxidation of organic matters. ^ Air and Rain, p. 437. The results are stated in milligrammes per cubic metre, instead of grammes per million ciibic metres. *In the garden of St. Mary's Hospital, Paddington, I found .5280 and .5206 mgms. per M. C. (See page 124.) In the back yard of University-College Hospital, .2060 and .3675.— [F. de C] ' Annuaire de I'Observatoire de Montsouris pour I'an 1882. ' See Fodor, Die Luft, p. 84, 1881. ' Toropoff (of St. Petersburg), considers malaria poison gaseous ; after removing water, oxygen, and carbon dioxide, he found marsh air still yielded 84 to 89 per cent, of gaseous matter ; whilst hill air gave only 81. 132 PE ACTIO AL HYGIENE. Organic matter also exists in considerable quantity. Discovered by Vauquelin (1810 and 1811, in the air coUected over the Languedoc marshes), by De Lisle, and again by Moscati (1818, in the aii* of a Lombardy rice- neld), and examined more recently by Boussingaiilt (1829, 1839), Gigot (1859), and Becchi (1861), the organic matter seems to have much the same char- acter always. It blackens sulphuiic acid when the aii* is di-awn through it ; gives a reddish color to nitrate of silver ; has a flocculent appearance, and sometimes a pecuhar marshy smell, and, heated with soda-lime, affords e^•i- dence of ammonia. The amount in Becchi 's expeiiments was .00027 gi'amme in a cubic metre of air (=.000118 grain in 1 cubic foot). Ozone, led thi'ough a solution of this organic matter, did not destroy it. It is said to destroy quinine. Besides the organic matter, various vegetable matters and animals, floating in the air, ai-e aiTested when the aii' of mai'shes is di'awn thi'ough water, or siili:)huric acid, and debris of plants, infusoria, insects, and even, it is said, small Crustacea are found ; the ascen- sional force given by the evaporation of water seems, indeed, to be sufficient to lift compai'atively large animals into the aii'. Dr. M. P. Balestra' has described spores and sporangia of a httle algoid plant in the aii- of Rome and its vicinity, and the same plant is found abundantly in the water of the marshes near Rome. Balestra is inclined to attribute marsh fever to this ■widely diffiised " microj)hyte gi-anule ; " whilst the researches of Klebs and Tommasi-Ci-udeli have led them to attribute it to a form of bacillus, which they have called JJ. malarice.'' It has been stated that ozone is deficient in the air over marshes, but the observations of BurdeF do not confiiTQ this. He often found as much ozone as in other air. In the air collected from the sui'face of lakes, containing some aquatic plants, especially Chara, there is a large proportion of oxygen, and this air gives, near the surface, the reaction of ozone (Clemens), while at some feet above the reaction is lost. This is usually ascribed to the oxidation of organic matter, which rises simultaneously fi'om the water. Air in the Holds of Ships. The air in the holds of ships is compounded of exhalations from the wood, bilge-water, and cargo. Owing to the comparative immobility of the air, it often becomes extremely foul. The composition is not known, but the .smell of hydrogen sulphide is very perceptible, and white paint is blackened. In some cases, when the water-tanks are filled by condensed water from the engines, which is not well cooled, the hold may become ex- tremely hot (100^ to 120° Fahr.), and decomposition be much increased. Air of Mines. In the metalliferous mines the air, according to Angus Smith,* is poor in oxygen (20.5 per cent, sometimes), and veiy rich in carbon dioxide (7.85 per 1,000 volumes on a mean of many exiDcriments). It also contains or- ganic matter, giving, when burnt, the smell of burnt feathers, in uncertain amount. These impurities arise from respiration, combustion from lights, and fi'om gunpowder blasting. This latter process adds to the air, in ad- dition to carbon dioxide, caibon monoxide, hydrogen and hydrogen sul- ' Comptes Rendus, 1870, No. 3, July, p. 235. ' Studii suUa Natura della Malaria, Roma, 1879. ' Eecherches sur les fievres paludeennes, 1858. * Report on Mines, Blue Book, 1864. AIR. 183 phide, various solid particles, consisting of suspended salts, which may amount to as much as 3 grains in each cubic foot of air. These suspended substances are principally potassium sulphate, carbonate, hyposulphite, sulphide, sulphocyanide, and nitrate, carbon, sulphur, and ammonium ses- quicarbonate. Much of this may hereafter be avoided by the new process of getting coal, by means of compressed quickhme, which is slacked in holes drUled in the coal. SECTION n. DISEASES PRODUCED BY IMPURITIES IN AIR. Sub-Section I. — Suspended Solid Mattees. 1. Dead Substances. — The effect which is produced on the respiratory organs by substances inhaled into the lungs has long been known. Eam- azzini and several other writers in the last century, and Thackrah fifty years ago in this country, directed special attention to this point, and since that time a great amount of evidence has accumulated, ' which shows that the effect of dust of different kinds in the air is a far more potent cause of respiratory diseases than usually admitted. Affections of the digestive organs are also caused, but in a much slighter degree. The respiratory affections are frequently recurring catarrhs (either dry or with expectoration) and bronchitis, with subsequent emphysema, although this . sequence appears from the figures given by Hirt to be not quite so fre- quent as was supposed, perhaps from the cough not being violent. Acute pneumonia, and especially chronic non-tubercular phthisis, are also pro- duced. The suspended matters in the air which may pi'oduce these affections may be mineral, vegetable, or animal ; but it would seem that the severity of the effects is chiefly dependent on the amount of dust, and on the physical conditions as to angularity, roughness, or smoothness of the particles, and not on the nature of the substance, except in some special cases. A large number of the unhealthy trades are chiefly so from this cause ; this is the case, in fact, with miners of all kinds.'' Mr. Simon^ states, that with one exception, the 800,000 miners in England break down as a class prematurely from bronchitis and pneumonia caused by the atmosphere in which they live. The exception is most important. The colliers of Durham and Northumberland, where the mines are well ventilated, do not appear to suffer from an excess of pulmonary disease, or do so in a slight degree only. In different mines, also, the amount of ' The whole siib'ect has been lately very carefully investigated by Hirt. Die Krankheiten der Arbeiter, Erste Theil, Staubinhalations-Krankheiten, von Dr. L. Hirt. 1871 . See also Eulenberg, Gewerbe Hygiene, 1876. ■■^ Thackrah enumerates the following in his work on the Effect of Arts, Trades, and Professions on Health, 1832, p. 63:— The workmen who were affected injuriously by the dust of their trades 50 years ago, and the same list will almost do for the present day : Cornmillers, maltsters, teamen, coffee-roasters, snuff-makers, papermakers, ilock- dressers, feather-dressers, shoddy-grinders, weavers of coverlets, weavers of harding, dressers of hair, hatters employed in the bowing department, dressers of colored leath- er, workers in flax, dressers of hemp, some workers in wood, wire-grinders, masons, colliers, iron miners, lead miners, grinders of metals, file-cutters, machine-makers, makers of firearms, button-makers. Hirt (op. cit.) also gives an extended table. 3 Fourth Report of the Medical Officer of the Privy Council, 1862, p. 15 et seq. See also Arlidge, in B. and F, Med. Chir. Rev., July, 1864, for the effects of the pottery trade. 134 PRACTICAL HYGIENE. pulmonary disease is different, apparently according to the amount of ven- tilation. The following table is given by the Registrar-General : — ' Average Annual Deaths per 1,000 from Pulmonary Disease during the Years 1860-62 inclusive. Metal Miners Metal Miners Metal Miners Males, exclu- Ages. in Cornwall. in Yorkshire. in Wales. in Yorkshire. Between 15 and 25 years, 3.77 3.40 3.02 3.97 25 " 35 " 4.15 6.40 4.19 5.15 35 " 45 " 7.89 11.76 10.62 3.52 45 " 55 " 19.75 23.18 14.71 5.21 55 " 65 " 43.29 41.47 35.31 7.22 65 " 75 " 45.04 53.69 48.31 17.44 The enormous increase of lung diseases among the miners after the age of 35, is seen at a glance. In the pottery trade all classes of workmen are exposed to dust, especially, however, the flat pressers. So common is emjihysema that it is called "the potters' asthma." So also among the china scourers ; the light flint dust disengaged in great quantities is a "terrible irritant." Dr. Greenhow states that all sooner or later become " asthmatical." The grinders of steel, especially of the finer tools, are perhaps the most fatally attacked of all, though of late years the evil has been somewhat lessened by the introduction of wet-grinding in some cases, by the use of ventilated wheel-boxes, and by covering the work with linen covers when practicable. The wearing of masks and coverings for the mouth appears to be inconvenient, otherwise there is no doubt that a great amount of the dust might be stopped by vei*y simple contrivances." Button-makers, especially the makers of pearl buttons, also suffer from chronic bronchitis, which is often attended with haemoptysis. So also pin- pointers, some electro-plate workmen, and many other trades of the like kind, are more or less similarly affected. In some of the textile manufactures much harm is done in the same way. In the carding rooms of cotton, and wool, and silk spinners, there is a great amount of dust and flue, and the daily gi-iuding of the engines disengages also fine particles of steel. Since the cotton famine, a size composed in part of china clay (35.35 grains of clay in 100 of sizing on an average), has been much used in cotton mills, and the dust arising seems certainly to be producing injuiious efi'ects on the lungs of the weaver. ° In flax factories a very irritating dust is produced in the process of hackling, carding, line-preparing, ' and tow-spinning. Of 107 operatives, whose cases were taken indiscriminately by Dr. Greenhow, no less than 79 were suffering from bronchial imtation, and in 19 of these there had been ' Report of the Commissioners on Mines, Blue-book, 1864. '■' See for further particulars and much interesting information Dr. Hall's paper read at the Social Science Congress in 186.5. " G. Buchanan's Report on certain Sizing Processes used in the Cotton Manufacture at Todmorden. Ordered to be printed by the Hovise of Commons. May, 1872. AIR. 135 hsemoptysis. Among 27 hacklers, 23 were diseased.' In shoddy factor- ies, also, the same thing occurs. These evils apj)ear to be entirely and easily preventable. In some kinds of glass-making, also, the workmen suffer fx'om floating particles of sand and felspar, and sometimes potash or soda-salts. The makers of grinding-stones suffer in the same way ; and children working in the making of sand-paper are seriously affected, sometimes in a very short time, by the inhalation of fine particles of sand into the limgs. In making Portland cement, the burnt masses of cement are ground down and then the powder is shovelled into sacks ; the workmen doing this cough a great deal, and often expectorate little masses of cement. Some of them have stated that if they had to do the same work every day, it would be impossible to continue it on account of the lung af- fection. The makers of matches, who are exposed to the fumes of phosphorus, suffer from necrosis of the jaw, if there happens to be any exjDosed part on which the fumes can act. This, however, is now obviated by the use of amorphous or red phosjDhorus, which is harmless. In making bichromate of j^otash, the heat and vapor employed carry up fine particles, which lodge in the nose and cause great irritation, and finally ulceration, and destruction of both mucous membrane and bone. Those who take snuff escape this. The mouth is not affected, as the fluids dissolve and get rid of the salt. The skin is also irritated if the salt is rubbed on it, and fistulous sores are apt to be produced. No effect is noticed to be produced on the lungs. ^ Washing the skin with subacetate of lead is the best treatment. In the process of sulphuring vines the eyes often suffer, and some- times (especially when lime is used with the sulphur) decided bronchitis is produced. In some trades, or under special circumstances, the fumes of metals, or particles of metallic compounds, pass into the air. Brassfounders suf- fer from bronchitis and asthma, as in other trades in which dust is in- haled ; but in addition they also suffer from the disease described by Thackrah as "brass ague," and by Dr. Greenhow as "brassfounders' ague." It appears to be produced by the inhalation of fumes of zinc oxide ; ^ the symptoms are tightness and oppression of the chest, with in- definite nervous sensations, followed by shivering, an indistinct hot stage, and profuse sweating. These attacks are not periodical. Coppersmiths are affected somewhat in the same way, by the fumes arising from the partly volatilized metal, or from the spelter (solder). Tinplate workers also suffer occasionally from the fumes of the solder- ing. Plumbers inhale the volatilized oxide of lead which rises during the process of casting. Nausea and tightness of the chest are the first symp- toms, and then colic and palsy. ' Mr. Simon's Fourth Report, p. 19. ^ Chevallier, Ann. d'Hygi. ne, July, 1863, p. 83. ^ Some doubt has been expressed as to those symptoms being produced by pure zinc fumes ; see Hirt (op. cit.), who says that men employed in making zinc houses, where they inhale pure zinc fumes without copper, never suffer from, brassfounder's ague. On the other hand, he describes very graphically the effect of the metallic fumes (copper ?) on himself. The workmen think that drinking large quantities of milk lessens the severity of the attacks. 136 PRACTICAL HTGTENE. Manufacturers of white lead inhale the dust chiefly from the white beds and the packing. House painters also inhale the dust of white lead to a certain extent, though in these, as in former cases, much lead is swallowed from want of cleanliness of the hands in taking food. "V\'orkers in tobacco factories suffer in some cases, and there are persons who can never get accustomed to the work ; yet with proper care and ven- tilation it appears ' that no bad effects ordinarily result. Workers in mercuiw, silverers of miiTors, and water gilders (men who coat silver with an amalgam of mercury and gold), are subject to mer- ciu'ialismus. But electricity has rendered gilding with the aid of mercury to some extent obsolete ; and the making of miiTors with nitrate of silver may perhaj^s ultimately abolish all the hoiTors of mercurial labor. "Workmen who use arsenical compoimds, either in the making of wall papers or of artificial flowers, etc., suffer from slight symj^toms of arsenical poisoning, and many persons who have inhaled the dust of rooms jDapered with arsenical papers have suffered from both local and constitutional effects, — the local being smarting of the gums, eyes, nose, oedema of the eyelids, and httle ulcers on the exposed jmrts of the body ; the constitu- tional being weakness, fainting, asthma, anorexia, thirst, diaiThora, and sometimes even severe nen-ous symptoms.^ Arsenic has been detected in the urine of such jDcrsons. A. Manouvi'iez^ gives an account of the diseases among workmen in France employed in making patent fuel, a mixture of coal-dust and pitch. He says they suffer fi-om melanodermy, cutaneous eruptions, and epithelial cancers, affections of the eyes, ears, and nose ; bronchitis with pulmonary pseudo-melanosis ; and gastro-entero-hepatic disorders. Hirt also men- tions some of the diseases produced among workmen by the various tar- products. 2. Living Substances, as Infusoria, Fungi, Algcc, or their germs, or Pol- len or Effluvia of Floicers. — That summer cataiTh or hay fever is produced in many persons by the poUen from grasses (especially Anthoxanthum odor- atum), trees or flowers, is now generally admitted. The researches of Dr. Blackley,^ of Manchester (himself a sufferer), have i^laced the matter beyond a doubt. In his case, at least, it was pollen that produced the disease, and not the effluvia merely. Coumarin had no effect. Grass-pollen (which constitutes 95 per cent, of the pollen floating in the atmosphere) and the pollen from pine-trees were the most powerful in effect. Curiously enough, the pollen of poisonous jDlants, such as the Solanace.T?, was often compara- tively innocuous. It is also known that the sj^ores of certain /M»_r/i in fall- ing on a proper soil may cause disease of the skin in men, and that tinea and fa c us are thus sometimes spread seems certain. There is a growing belief in the connection of the specific diseases with low vegetable forms. Dr. Salisbui-y, of Ohio, attempted to trace ague to a Palmella ; others have ascribed it to the Oscillarinece generally ; Dr. Balestra believes that a special alga is the efficient cause, and Klebs and Tommasi-Crudeli attribute it to the Bacillus n^alarUe. Dr. Salisbury has also affirmed that the prevalence of measles in the Federal army arose from fungi from mouldy straw. He inoculated him- self, his wife, and foriy other j^ersons with the fungi, and produced a dis- ' Hirt, op. cit., pp. 162, 163. - See paper bv Mr. Jabez Hogg, Sanitary Record, April 25, 1879. ^ Annales d'Hygiene, March, 1876. ■* Op. cit. AIR. 137 ease like measles in from twenty-four to ninety-six hours. It is stated also that this disease was protective against measles. Dr. Woodward (United States Army) has repeated Dr. Salisbury's experiments, but does not confirm them.' Professor Hallier, of Jena, has to some extent adopted the view that fu.ngi give rise to some of the specific diseases, and that the spores float in the air, and are thus communicated, but the proofs are not satisfac- tory. " Di'. D. D. Cunningham says that he was unable to connect any disease, in Calcutta, with the occurrence of bacteria or other bodies in the air, either as regards variation in kind or in quantity. Blackley found that Ghop.tonlum elatum (bristle mould) produced nausea, fainting, and giddiness, and the spores of penicillium (inhaled) brought on hoarseness, going on to complete aphonia ; the condition lasted tv/o days, and ended in a sharpish attack of catarrh. Pettenkofer, Von Nageli, Fodor, and many others distinctly attribute specific diseases to bacteria of certain kinds. The connection of the wool- sorters' disease with the existence of bacillus in the holj of the patient has been established, and this is in all probabihty inhaled from the atmos- phere in which the men work. Koch has recently demonstrated the presence of a bacillus in cases of phthisis, and has apparently succeeded in cultivating it, and proj)agating the disease by that means. 3. The Gontagia. — Under this head it will be convenient to include the unknown causes of the specific diseases. That these in some cases (scarlet fever, small-pox, measles, typhus, enteric fever, plague, pertussis, yellow fever, influenza, etc.) reach the person through the medium of air (as well as in some cases through water or food) cannot be doubted. Some of these contagia have in some way a power of growth and multiplication in the body of a susceptible animal, but whether they can find nourishment, and thus grow in the air, is yet doubtful. It seems clear, however, that they can retain the powers of growth for some time, as the small-pox and scar- let fever poisons may infect the air of a room for weeks, and cattle plague and enteric fever poisons will last for months,^ and in this they resemble Protococci and other low forms of life, which can be dried for years, and yet retain vitality. The exact condition of the agency is unknown ; whether it is in the form of impalpable particles, or moist or dried ejDithelium and pus-cells, is a point for future inquiry ; and whether it is always contained in the substances discharged or thrown off from the body (as is certainly the case in small-pox), or is produced by putrefactive changes in those dis- charges, as is sujDposed to be the case in cholera and dysentery, is also a matter of doubt. Bakewell * collected dust deposited at a height of 7 or 8 feet in small-pox wards, which contained the minute scabs with the epi- dermic scales and variolous corpuscles which are thrown off from the skin 1 Camp Diseases in the U. S. Army, p. 278. The fungus is a Penirilliiim. ^ Many papers on this subject by Hallier and others are contained in Hallier's Zeitschrift fur Parasitenkunde. " The long retention of power by the enteric fever poison is shown by a case related by Dr. Becher (Army Med. Department Report, vol. 10, p. 237). The typhoid poison appears to have adhered to the walls and ceiling, and to have retained its power to ex- cite disease in another person for a month ; it was not destroyed by the heat of a very hot Indian station (Gwalior) in February. ■*Med. Times and Gazette, December 7, 1872. 138 PRACTICAL HYGIENE. in small-pox. Some modern expositors of the old doctrine of fomites would consider these orj^^anic matters to be inconceivably minute particles of li^Tng, or to use Dr. Beale's phrase, bioplastic matter, which is capable, he believes, of wonderfully rapid growth under proper conditions.' But it is also probable that some, if not all, the disease poisons are really living organisms, a \uew ver}'' widely received now both in this country and else- where. The specific poisons manifestly differ in the ease with which they ai'e oxidized and destroyed. The poison of typhus exanthematicus is very readily got rid of by free ventilation, by means of which it must be at once diluted and oxidized, so that a few feet give, under such circum- stances, sufiicient protection. This is the case also with the poison of ori- ental plague, while, on the other hand, the poisons of small-pox and Bcai'let fever will spread in spite of very free ventilation, and retain their power of causing the same disease for a long time. In the case of malaria, the process of oxidation must be slow, since the poison can certainly be caii-ied for many hundred yai-ds ; even sometimes for more than a mile in an upward direction (up a ravine, for instance), or horizontally, if it does not pass over the surface of water. The poison of cholera also, some have supposed, can be blown by the winds for some distance ; but the most re- cent observations on its mode of sj^read lead to the conclusion that the por- tability of the poison in this way has been greatly overrated. The poison of diphtheria appears also to be transported some distance by wind. But the specific poisons are not the only suspended substances which thus float through the atmosphere. There can be no doubt that while punilent and granular ophthalmia most frequently spread by direct transference of the pus or epithelium- cells, by means of towels, etc., and that erysipelas and hospital gangrene, in surgical wards, are often earned in a similar way, by dirty sponges and dressings, another mode of transference is by the passage into the atmos- phere of disintegrating pus-cells and putrefying organic p^.rticles, and hence the great efiect of free ventilation in military ophthalmia (Stro- meyer), and in erysipelas ' and hospital gangrene. In both these diseases, great evaporation from the walls or floors seems in some way to aid the diflfusion, either by giving a great degree of humidity, or in some other way. The practice of frequently washing the floors of hospitals is well known to increase the chance of erysipelas, and this might be explained, as Von Nageli suggests, by the moisture and subsequent drying helping the develojDment and subsequent dissemination of minute organisms. Sub-Section II. — Gaseous Matters. (a) Carbon Dioxide. — The normal quantity of CO., being .4 volume per 1,000, it produces fatal results when the amount reaches from 50 to 100 per 1.000 volumes ; and at an amount much below this, 15 to 20 per 1,000, it produces, in some persons at any rate, severe headache. Other persons can inhale, for a bi'ief period, considerable ciuantities of carbon dioxide without injury ; ^ and animals can be kept for a long time in an atmosphere highly charged with it, provided the amount of oxygen be also increased. In the air of respiration, headache and vertigo are produced when the ■ See chapter on Disinfection for a fuller notice of these points. ' See nij Reports on St. Mary's Hospital, loc. cit. — [F. de C] ^ It is stated that Sir R. Christison emplo3'ed air containing 20 per cent, of carbon dioxide as an anaesthetic. (Taylor's Jurisprudence, 1865, p. 713.) AIE. 139 amount of CO^ is not more than 1.5 to 3 volumes per 1,000 ; but then or- ganic matters, and possibly other gases, are present in the air, and the amount of oxygen is also lessened. Well-sinkers, -when not actually dis- abled from continuing their work by CO^, are often aiSected by headache, sickness, and loss of appetite ; bi;t the amount of CO^ has never been de- termined. The effect of constantly breathing an atmosphere containing an excess of C0„ (up to 1 or 1.0 per 1,000 volumes) is not yet perfectly known. Dr. Angus Smith ' has attempted to determine its effect of, per se, the influ- ence of the organic matter of respiration being eliminated. He found that 30 volumes per 1,000 caused great feebleness of the circulation, with, usually, slowness of the heart's action ; the res2:>irations were, on the con- traiy, quickened, but were sometimes gasping. These effects lessened when the amount was smaller, but were percej^tible when the amount was as low as 1 volume per 1,000 — an amount often exceeded in dwelling- houses. At the same time, this is not the case always, for in the air of a soda-water manufactory, when CO, was 2 per 1,000, Smith found no dis- comfort to be produced. The effects noticed by Smith have not been ob- served in experiments on animals, by Demarquay, W. Muller, and Eulen- berg,^ nor in other cases in men, as in the bath at Oeynhausen, where no effect is produced by the air of the room in which the bathers remain for 30 to 60 minutes, although it contains a large percentage. It has been supposed that lung diseases, especially phthisis, are produced by it ; but as this opinion has been drawn merely from the effects of the air of respi- ration, which is other^^■ise vitiated, it cannot be considered to stand on any siu'e basis. Hirt finds no symptoms of chi-onic poisoning by C0„, even in trades where acute poisoning occasionally occui-s.' The presence of a very large amoujit of C0„ in the air may lessen its elimination fi'om the lungs, and thus retain the gas in the blood, and in time j)Ossibly produce serious alterations in nutrition. (b) Carbon Monoxide. — Of the immense effect of carbon monoxide, there is no doubt. Less than one-half per cent, has produced poisonous symptoms, and more than one per cent, is rapidly fatal to animals. It ap- pears from Bernard's and fi'om Lothar Meyer's obseiwations,^ that the gas, volume for volume, comj)letely replaces the oxygen in the blood, and can- not be again displaced by oxygen, so that the person dies asphyxiated ; but Pokrowsky has shown ' that it may gradually be converted into carbon dioxide, and be got rid of. It seems, in fact, as Hoppe-Seyler conjectured, to completely paralyze, so to speak, the red particles, so that they cannot any longer be the carriers of oxygen. The obsei'vations of Dr. Edeber ° show that, in addition to loss of consciousness and destruction of reflex action, it causes complete atony of the vessels, diminution of the vascular pressure, and slowness of circulation, and finally paralysis of the heart. A very rapid parenchymatous degeneration takes place in the heart and muscles generally, and in the liver, spleen, and kidneys. Hirt ' says that at high temperatures (2o°-32^ Cent. = 77^^-90- Fahi'.) it produces convul- sions, but not at low temperatures (8°-12° Cent. = 46^^-53^ Fahr.). (c) Hydrogen Sulphide. — The evidence with regard to this gas is contra- ' Air and Eain, p 209 et seq. ^ Quoted hj Eoth. and Lex, op. cit., p. 1T6. 2 Die Krankheiten der Arbeiter, Erste Abtheilung, 2'" Theil, 1878. * De Sanguine Oxydo carbonico Infecto, 1858. Reviewed in Yirchow's Arcbiv, Band xv., 3()9. See also Letheby, Cliemical Xews, April, 1863. ° Yirchow's Arcbiv, Band xxx., p. 525 (1864). » Ibid., Band xxxii., p. 450 (1865). * Op. cit. 140 PRACTICAL HYGIENE. dictory. While dogs and horses are affected by comparatively small quan- tities (1.25 and 4 volumes per 1,000 volumes of air), and suffer from pm-ging and rapid prostration, men can breathe a larger quantity'. Pareut-Ducha- telet inhaled an atmosphere containing 29 volumes per 1,000 for some short time. ' When inhaled in smaller quantities, and more continuously, it has ap- peared in some cases harmless, in others hurtful. Thackrah, in his in- quiries, could trace no bad effects. It is said that in the Bonnington chemical-works, where the ammoniacal liquor from the Edinburgh gas- works is converted into sulphate and chloride of ammonium, the workmen are exposed to the fumes of ammonium and hydrogen sulphides to such an extent that corns are blackened ; yet no special malady is known to result. The same observations have been made at the Britannia metal-works, where a superficial deposit of sulphide is decomposed with acids. Hirt ^ has no doubt of the occuiTence of chronic poison among men who work among large quantities of the gas. The symptoms are chiefly weak- ness, depression, perfect anorexia, slow pulse, furred tongue, nnicous mem- brane of the mouth pale, as is also the face. Sometimes there is furuncu- loid eruption in dirferent parts of the body. Li some cases there are vertigo, headache, nausea, diarrhoea, emaciation, and head symptoms, "like a case of very slow-running tyj^hus." He notices differences of suscej^ti- bility, which is also sometimes increased with custom. So large a quantity of SH„ is given out from some of the salt marshes at Singapore, that slips of paper moistened in acetate of lead are blackened in the open air ; yet not only is no bad effect found to ensue, but Dr. Little has even conjectured (on very disputable grounds, however), that the SH^ may neutrahze the marsh miasma. On the other hand, some of the worst marshes in Italy are those in which SH^ exists in large quantity in the air ; and, in du-ect opposition to Little, it has been supposed that the highly poisonous action of the marsh gas is partly owing to the SH,,. Again, in the making of the Thames Tunnel, the men were exposed to SH„, which was formed from the decom- position of iron j^yrites ; after a time they became feeble, lost theu' appe- tites, and finally passed into a state of great prostration and anamia. Nor, so far as is known, was there anything to account for this except the pres- ence of SH^.^* Dr. Josephson and Eawitz ■* have also investigated in mines effects pro- duced apparently by SH„ ; two forms of disease are produced — pure nar- cotic, and convulsive and tetanic symptoms. In the first case, the men became pale, the extremities got cold. There was headache, vertigo, a small weak pulse, sweating, and great loss of strength. On this, spasms and tremblings sometimes followed, and even tetanus. These symptoms were acute, and not, as in the Thames Tunnel case, chronic. When these attacks occurred, the temperature was high and the air stagnant. The obsei-vations of Clemens, also, on the development of boils from the passage of SH, into the drinking water from the air, if not convincing, cannot be overlooked. The symptoms produced by ammonium sulphide in dogs are said, by ' On dogs, Herbert Barker found a larger quantity necessary than that stated above ; viz., 4.29 per 1,000 is rapidly fatal, 2.06 per 1,000 may be fatal, but .5 per 1,000 may produce serious symptoms. '■' Op. cit. 3 Taylor's Med. Jurisp., 1865, p. 727. ^ Schmidt's Jahr., Band ex., p. 334, and Band cxvii., p. 85. AIR. 141 Herbert Barker/ to differ from those of SH,. Tliere is vomiting without l^urging, quickened pulse, and heat of skin, followed by coldness and rajDid sinking, ^\^len hychogen and ammonium sulphides, dissolved in water, are injected into the blood," they, and especially SH„, produce the same symptoms as the injection of non-corpuscular putrid' tiuids, viz., profuse diarrhoeal evacuations, with sometimes marked choleraic symptoms and decided lowering of the temperature of the body, congestions of the lungs, liver, spleen, and kidneys, initation of the spine, and opisthotonos. But, in this case, a much larger quantity will be introduced than by inhalation through the lungs. {d) Carhuretted Hydrogen. — A large quantity of carburetted hydrogen can be breathed for a short time ; as much, perhaps, as 200 to 300 volumes per 1,000. Above this amount it produces symptoms of poisoning, head- ache, vomiting, convulsions, stertor, dilated pupil, etc. Breathed in small quantities, as it constantly is by some miners, it has not been shown to produce any bad effects ; but there, as in so many other cases, it is to be wished that a more careful examination of the point were made. Without producing any marked disease, it may yet act injuriously on the health. Hirt says that cases of chronic poisoning are not vm- common. (e) Ammoniacal Vapors. — An in-itating effect on the conjunctiva seems to be the most marked effect of the presence of these vapors. There is no evidence showing any other effect on the health.' if) Sulphur Dioxide. — The bleachers in cotton and worsted manufac- tories, and storers of woollen ai-ticles, are exposed to this gas, the amount of which in the atmosjohere is, however, unknown. The men suffer from bronchitis, and are frequently sallow and anaemic.^ When SO^ is evolved in the open air, and therefore at once largely diluted, as in copper smelting, it does not appear to produce any bad effects in men, though from being washed down with rain, it affects herbage, and, through the herbage, cattle, causing affections of the bones, falling off of the hair, and emaciation. (g) Hydrochloric Acid Vapors in large quantities are very irritating to the lungs ; when poui-ed out into the air, as was formerly the case in the alkah manufactures, they are so diluted- as apparently to produce no effect on men, but they completely destroy vegetation. In some processes for making steel, hydrochloric, sulphurous and nitrous acids, and chlorine are all given out, and cause bronchitis, pneumonia, and destruction of lung tissue, as well as eye diseases.^ (h) Carbon Disidphide. — In certain processes in the manufacture of vulcanized india-rubber a noxious gas is given off, supjDosed to be the vapor of carbon disulphide. It produces headache, giddiness, pains in the hmbs, formication, sleeplessness, nervous depression, and complete loss of appetite. Sometimes there is deafness, dyspnoea, cough, febrile attacks, and even amaurosis and paraplegia (Delpech). The effects seem due to a direct anaesthetic effect on the nervous tissue. ^ On Malaria and Miasmata, p. 212. 2 Weber, Syd. Soc. Tear-Book for 1874, p. 227. 2 See Schloesing, Comptes Rendus, 1875, vols. i. and ii. * On the other hand, persons living in volcanic countries have sometimes a notion that the fumes of SOo are good for the health ; I have been told so by people in the neighborhood of Vesuvius. — [F. de C] ° Jordan, Canstatt's Jahresb. for 1863, Band vii, , p. 76. 142 PKACTICAL HYGIENE. Sub-Section III. — Effect of Air Impure from several Substances ALWAYS Coexisting. The examination of the effects of individual gases, however important, can never teach us the results which may be produced by breathing air rendered foul by a mixture of impui-ities. The comi^osite effect may possi- bly be very different from what would have been antici2:)ated from a knowl- edge of the action of the isolated substances. (a) Air rendered Impure by Iiet^^^ oi* 7^ = 3 = number of thousands of cubic feet of air re- quired. This formula may also be used conversely, in order to find from the condition of the air the average amount of fresh air which has been hither- to supphed and utihzed. For this piu-pose we simply substitute for p (the admissible hmit) p,, the observed ratio. Thus, let us suppose that p^, the observed ratio of vitiation, was 0.7 per 1,000 vols., we should have : 0.6 jY^ = 0.857 = number of thousands of cubic feet, or 857 cubic feet of air per head per hour had been supphed and utilized duiing the time of occupation. We can also calculate the probable condition of an au--space in which a e given quantity of aii* is supphed : thus, -r — p^; taking the amount directed for soldiers in baiTacks, viz., 1,200 per hour, we have (assuming that e represents in this case 0. 7) 0.7 1 200 "^ 0.000583 CO, per cubic foot, or 0.583 per 1,000 vols. ' Spe Dr. F. de Chaumont's papers in the Lancet, September, 1866, and Ediu. Med. Journal, May, lj^67 ; also Professor Donkin's Memorandum in the Blue Book of the Committee on the Cubic Space oirthe Metropolitan Workhouses (1867). VENTILATION-. 161 Where the quantity e is less than the above amounts, as for instance in the case of children, we should have, assuming children to evolve 0.4 of a cubic foot, 0.4 7 /. 1 . „ vr-n = 2 = number of thousands of cubic feet of air required. For a long time after this subject first attracted attention the amount of fresh air supposed to be necessary was put at too low a figure. Even the figures of General Morin,' which were a great advance at the time, are insufficient. He proposed 2,118 cubic feet (60 cubic metres) for barracks at night, and Eanke adopts the same figures. Koth and Lex^ adopt the maximum of total impurity at .6 per 1,000, which includes 0.4 of initial CO^ ; and as they estimate the expired CO^ as 20 litres,^ or .706 cubic feet (Eng.) per hour, they give the hourly quantity of air as 100 cubic metres, or 3,533 cubic feet. It is highly desirable that some general agTeement should be come to as to the amount of air necessary, even if it be admitted that the desired amount cannot always be obtained. If we adopt the following amotmts of C0„ as being evolved during repose, we shall not be far from the probable truth- AdrJt males (say 160 lb weight) 0.7 of a cubic foot " females ( " 120 lb " ) 0.6 ChUdren ( " 80 lb " ) 0.4 Average of a mixed community 0.6 " Under those conditions the amount of fresh aii* to be supphed in health during repose ought to be — For adult males 3,500 cubic feet per head per hour. " " females 3,000 " childi-en 2,000 " . " a mixed community . . . 3,000 " " " The amount for adult males as above given is just 100 cubic metres, or if we take it at 3,600 cubic feet, it is just one cubic foot per second. These numbers are easy to remember. When we have to deal with places, the inmates of which are actively employed, such as workshops and the like, the amount of air supplied must be proportionately increased. We have seen that in light work the CO^ evolved per hour is nearly 0.006 of a cubic foot per fib of body weight, and in hard work at least double that amount, — so that for a man of 160 lb weight we should have — In hght work 0.95 of a cubic foot of CO., evolved per hour. In hard work 1.96 This would argue a dehvery of fresh air as follows : — In light work 4,750 cubic feet. In hard work 9,800 It was stated long ago, from extensive observations, that in mines, if it was wished to keep up the gTeatest energies of the men, no less than 100 cubic feet per man per minute ( = 6,000 per hour) must be given ; if the ' Rapport de la Commission sur le Chauffage et la Ventilation des Batimens dii Palais de Justice, Paris, 1860 ; also Manual Pratique du Chauffage et de la Ventilation, 1874. - Op. cit., p. 221. 2 This amount is also adopted by General Morin. Vol. I.— 11 162 PRACTICAL HYGIENE. quantity were reduced to one-third, or one-half, there was a serious dimi- nution in the amount of work done by the men. This amount included, of course, all the air wanted in the mine for horses, lights, etc' TJie amount for animah is an important question which has been httle studied. Marcker ° gives the following from experiments : — For large cattle (viz., oxen, etc.) 30 to 40 cubic metres per hour for every 1,000 lb weight, or 1 to 1^ cubic foot for every lb weight. For amall cattle (viz., sheep, etc.) 40 to 50 cubic metres j^er hour for every 1,000 tti weight, or l^to If cubic foot for every lb weight ; the higher quantity being given on account of the more rapid tissue change in the smaller animals. These quantities seem absurdly small, and the chief reason for so limiting them seems to have been the fear of lowering the temperature too far. This is an erroneous view : animals proj)erly fed will thrive better in a well-ventilated place at a low temperatiire than in a warmer place ill- ventilated. There seems no reason why the same rule should not apply to animals as to man, in which case something like 20 to 25 cubic feet per hour per lb of body weight ought to be supplied. A horse or a cow ought, therefore, to have fi'om 10,000 to 20,000 cubic feet per hour, — in short, it ought to be practically in the open air. 2. ON THE QUANTITY OF AIK REQUIRED FOR LIGHTS, IF THE AIR IS TO BE KEPT PURE BY DILUTION. Air must be also supplied for lights if the products of combustion are allowed to pass into the room. Wolpert has calculated that, for every cubic foot of gas, 1,800 cubic feet of air must be introduced to dilute properly the products of combustion ; and this is not too much if we remember that a cubic foot of good coal gas produces about 2 cubic feet of carbon dioxide, and that sulphur dioxide and other substances may be also formed. A common small gas burner will burn nearly 3 feet per hour, and wiU con- sume 10 or jDrobably 12 cubic feet in an evening (4 hours), and therefore from 18,000 to 21, GOO cubic feet of air must be introduced for this pur- pose alone in the 4 hours, unless the products of combustion are removed by a special channel.^ The power of illumination being equal, gas does not produce more CO,, than candles (Odling), but usually so much more gas is burnt that the air is much more deteriorated ; there is also greater heat and more watery vapor. The products should never be allowed to escape into the air of the room. Weaver has shown how important a source of impurity this is ; and the bad effects of breathing the products of gas combustion are well known. One lb of oil demands, for complete combustion, 138 cubic feet of air ; and to keep the air perfectly pure, nearly as much air must be introduced for 1 ft) of oil as for 10 feet of gas. In mines, 60 cubic feet per hour are allowed for each light ; the lights generally are dim, and the amount of combustion is slight ; but this seems an extremely small amount. If gas is not burnt in a room, or in a very smaU amount, or if only candles or oil lamps are used, it is seldom necessai-y to take them into ac- count in estimating the amount of air. ' Proceedings of the Civil Engineers, vol. xii., pp. 298 and 308. "^ Op. cit. ^ See an elaborate table by M. Layet, Eevue d'Hygiene, vol. ii., pp. 1096-7. VENTILATION. 163 3. ON THE QUANTITY REQUIRED FOR THE RESPIRATION AND DILUTION OF THE EMANATIONS OF SICK MEN. In making differential experiments among tlie healtliy and the sick, it has been found ' that among the former the smell of organic matter was still imperceptible when the air contained 0.208 per 1,000 of respiratory impurity as CO^ ; but in hospitals containing ordinary cases it was quite distinct when the CO^ reached 0.166. From this we may conclude that the minimum amount of fresh air for hospitals ought to exceed that re- quired in health by at least one-fourth. If 3,000 cubic feet per hour be admitted as a general average in health, we may demand in round numbers 4,000 in sickness ; and if we have to deal with adult males only, such as soldiers, 4,500 per head per hour. When we have to deal with serious cases, a still greater amount must be given, reaching 5,000, 6,000, or even more if possible, — in fact, the supply should be unlimited. These views are in accordance with the results of experimental inquiry (Grassi in Paris ; Sankey in London ; Sutherland). In some diseases, so much organic substance is thrown off, that scarcely any ventilation is sufficient to remove the odor. In some of the London hospitals Dr. de Chaumont found that there was still a close smell when 5,000 cubic feet and even more were supplied, but the distribution was not perfect. Even when 3,600 feet were supplied and utilized (as calculated from the C0„) the ward was not free from smell. The best surgeons now consider an almost complete exposure of pyaemia patients to the open air the best treatment ; and it is well known that in typhus fever and (to a less extent) in typhoid, and also in small-pox and plague, this complete ex- posure of patients to air is the first important mode of treatment, before even diet and medicines. Even temperature must be sacrificed to a con- siderable extent, in order to obtain fresh air, if a choice requires to be made between the two. Humidity. — The condition of the air as regards humidity is a matter of some importance, but has not hitherto been much considered. In Dr. de Chaumont's experiments the mean humidity, in rooms having less than 0.2 per 1,000 of respiratory impurity (reckoned as CO J, was 73 per cent., at a temperature of 63° Fahr. This might be taken, provisionally, as a stand- ard,^ at least for climates like our own. In drier climates, however, as in America, such a condition would not be attainable in many cases, when the external air has a mean humidity of 40 or even 30 per cent. In Ger- many 50 per cent, is looked upon as an average humidity, whilst in Eng- land this would indicate an exceptionally dry atmosphere. ' The Theory of Ventilation, by Dr. de Chaumont, Proc. Roy. Soc. , loc. cit. '■^ From the state of the air as regards humidity, information may sometimes he obtained which might take the place of the COo determination, in the absence of means for carrying out the latter. For instance, at St. Mary's Hospital, the air of the wards was found to have 78 per cent, of humidity, or 5.8 per cubic foot ; to reduce it to 73 per cent., or 5.5 grains per cixbic foot, while the external air contained 5.3, we 5 8—5 5 8 should have ' — '- = — — 1, or we should require to add to the existing delivery 5.5— 5. /i O.o of air, at least as much more per hour as would equal the total cubic space. In the case referred to this was about 2256 cubic feet. The actual supply was 2080, total 483(5 per head, or about the quantity demanded for proper hospital ventilation. 104 PRACTICAL HYGIENE. SECTION n. THE MODE IN WHICH THE NECESSARY QUANTITY OF FRESH AIR CAN BE SUPPLIED. This is an engineering problem, and there can be no doubt that in time to come it will be as carefully considered by engineers as the supply of "water, or the removal of the solid and fluid excreta. Ventilation is, in fact, the problem of the removal of the gasiform excreta of the lungs and skin. Sub-Section I. — Preliminary Considerations. 1. Cubic Space.^ — A certain amount of fresh air has to pass through a given air-space in a fixed time in order to maintain a certain degree of purity ; the amount has been fixed at 3,000 cubic feet for each healthy person in an hour ; before considering the appliances for moving this air, we must consider what should be the minimum size of the air-space through which the fresh air has to pass. This will entirely depend on the rate at which air can be taken through the space without the movement being perceptible or injurious. The size of the si^ace is of consequence, chiefly, in so far as it affects this condition. The larger the air-space the less is the necessity for the frequent renewal of air, and the less the chances of draught. Thus a space of 100 cubic feet must have its air changed thirty times in an hour, if 3,000 cubic feet of air are to be given, while a space of 1,000 cubic feet need only have it changed three times in an hour for an equal ventilation. When the most perfect mechanical means are employed, the air of even a small air-si:)ace can be changed sufficiently often without draught. Thus, in Petteukofer's experimental room at Munich, the air-space is 424 cubic feet, and 2,G40 cubic feet can be drawn through by a steam engine in an hour without perceptible movement ; in other words, the change is six times per hour nearly. With the best mechanical contrivances, and with disregard of cost, we are therefore certain that a cubic space of GOO feet would be sufficient, and there is every probability that engineers could ventilate even a smaller space without perceptible movement. But if the mechanical contrivances are of an inferior kind, and par- ticularly if natural ventilation is used, the difficulties of ventilating a small space are considerable, and are caused not so much by the rate of movement of the greater part of the air in the room, as by the rate at the openings where the fresh air comes in very quickly, and causes currents in the room. Suppose, for example, a space of 500 cubic feet with a man ' In the metropolitan lodging-houses, 30 superficial and 240 cubic feet are allowed ; in the section-houses of the metropolitan police 50 superficial and 450 cubic feet are given. The Poor-law Board allows BOO cubit feet for every healthy person in dormi- tories, and from 850 cubic feet and upward, according to circumstances, as far as 1,200 subic feet for every sick person. In Dublin, an allowance of 300 cubic feet is re- quired in the registered lodging-houses. — (From an excellent pamphlet, entitled Essen- tials of a Healthy Dwelling, p. 13. ) In the Prussian army the allowance is 495 cubic feet (Prussian measurement, which is nearly the same as English), the superficial space being 42-45 square feet ; in the old Hanoverian army the cubic space was 700 to 800 cubic feet (Prussian). The London School Board have given, in a general school- room, 10 square feet per scholar, and in graded schools 9 square feet; the height was ordered to be 13 feet — making 130 and 117 cubic feet respectively. This seems very small. VEi!?^TILATIOI«". 165 in it, who has to be supplied -with 3,000 cubic feet in an hour ; if the iulet opening be 12 square inches, the rate of movement through it would be 10 feet per second, or nearly 7 miles ^ev hour ; if 24 square inches, it would be five feet, or about 3.4 miles per hour. In either case, in such a small room, the air could not be properly distributed before reaching the person, and a draught would be felt. If instead of 500 cubic feet 1,0(30 be given, the problem is easier, for the small cui-rent of fresh air mixing with the larger volume of aii' in the room is more easily broken up, and the man being further from the opening, the movement is less felt. The question, in fact, turns in great measure on the power of introducing the air without draught. If the renewal of air is carried on by what is termed natural ventila- tion, under the ordinaiw conditions of this climate, a change at the rate of six times per hour, as in Pettenkofer's room, could not be attempted. Even five times per hour would be too much ; for, in bai-racks with 600 cubic feet per head, the rooms are cold and draughty, when anything ap- proaching to 3,000 cubic feet per head per hour are passing through ; that is a change of five times per hour for each GOO cubic feet of air-space. A change equal to three times per hour- is generally all that can be borne under the conditions of warming in this country, or that is practically attainable, and if this be correct, from 1,000 to 1,200 cubic feet should be the minimum allowance of the initial air-space. With good warming and an equable movement, which, however, is not always easy to get, there might be larger inlets and therefore more easy distribution and a smaller au'-siDace to begin with. If the inlets are 48 square inches, the rate through them to supjDly a space of 500 cubic feet with 3,000 cubic feet j)er hour would be only '2^ feet per second ; and if, as should be the case in artificial ventilation, the inlet is 72 or 80 square inches in size, the rate would only be a httle over 1-| foot per second, which would be imperceptible even at the orifice. But there is an argu- ment against a small cubic space, even with good mechanical ventilation, viz., that if anything arrests the mechanism for a time, the ratio of impurity from respiration increases much faster in a small than in a lai-ge space.' The wainnth of the moving au' influences the sensation of the persons exposed to it. At a temperatui-e of 55' or 60", a rate of 1 J foot per second ( =: 1 mile per hoiu- nearly) is not perceived ; a rate of 2 to 24- per second (1.4 and 1.7 miles per hoiu-j is imperceptible to some j)ersons ; 3 feet per second (2 miles per houi* nearly) is jDerceptible to most ; a rate of 3^ feet is perceived by all persons ; any greater speed than this vciR give the sen- sation of draught, especially if the enteiTtig air be of a drfferent temperature, or moist. If the air be about 70' Fahr., a i-ather greater velocity is not per- ' Experimental data on many of these points are still -wanting. In prisons, -with cells for separate confinement and artificial ventilation, tlie amount of space is seldom nnder 750 to SOO cubic feet, and practically this is found to be too small. In Pentonville Prison, on Jebb's system, the air -was hardly ever changed three times in the hour, during my experiments, although the cells are nearly feuO feet in capacity. The mean supply of air per hour -was about 1,0.56 cubic feet. In Gosport military prison, also on Jebb's principle (but not perfectly carried out), the mean supply vras about 800 cubic feet, but the cells are only about 600 in capacity. In Alder- shot military prison (not on Jebb's principle) -vrith cells about 600 cubic feet in size, the mean supply -sras under 500. And in Chatham convict prison, -where the cells are only 200 the mean supply -was about 480. Wilson (Hand-book of Hygiene) appears to have found the air changed in the large cells at Portsmouth convict prison about three times in the hour, and in the small about four times ; this, ho-wever, is certainly not the rule.— (F. de C.) 166 PRACTICAL HYGIENE. ceived, while if it be still higher (80° to 90° Fahr.), the movement becomes again more perceptible, and this is also the case if the temperatiire be be- low 40^ Fahr. If the aii- coiild be warmed to a certain point in a cold ch- mate, or if the climate be warm, there may be a much more rapid cun-ent, and consequently a smaller cubic space might be given. The subject of ventilation is in cold climates connected inseparably with that of warming, for it is impossible to have efficient ventilation in cold weather without warming the air. The amount of cubic space thus assigned for healthy persons is far more than most people aro able to have ; in the crowded rooms of the artisan class, the average entire space would probably be more often 200 or 250 cubic feet per head than 1,000. The expense of the lai-ger rooms would, it may be feared, be fatal to the chance of such an ideal standard being generally carried out ; but, after all, the question is, not what is likely to be done, but what ought to be done ; and it is an encouraging fact that in most thuigs in this world, when a right course is recognized, it is somehow or other eventually carried out. So, in the case of soldiers, the amount of authorized regulation space (600 cubic feet), is below the standard now given, bvit still the space is as much as can be demanded at present, as it has been found veiy difficult, without incurring greater expense than the country would bear, to give every man even the 600 cubic feet. For sick persons the cubic space shovdd be more than for healthy per- sons. We are to remember that there are other impurities besides those arising from respiration and transpiration, and that immediate dilution and as speedy removal as can be managed are essential. Very much the same considei*ations apply to sick as to healthy men, ex- cept that the allowance of air in all cases of acute diseases mvist be gTeater ; and, therefore, especially if natiu-al ventilation be employed, the cubic space has to be enlarged also, to insvu-e good distribution without draught, for siu'face chilling must be carefully avoided. Admitting that, in hospitals, a minimum of 4,000 cubic feet of fresh air per patient jjer hour should be supj^lied, if the change of air is to be three times per hour, as the best available rate of movement, the cubic space must be about 1,300 cubic feet. A consideration of another kind may aid in de- termining the question as regards sick men. In hospitals a certain amoimt of floor-space is indispensably necessary ; first, for the lateral separation of jDatients ; secondly, for convenience of attendance. For the first object, the gi-eater floor-sj^ace the better ; and in respect of the second, Dr. Acland has clearly showoi that the minimum floor-space for convenient nursing should be 72 square feet per bed.' In a ward of 12 feet in height this would give only 864 cubic feet, which is much too small. Considering, however, the immense benefit to patients of pure air, and the practical experience of hospital physicians, it is very desirable not to fix the floor and cubic space of hospital wards at the minimum of what may suffice. The clesu'e of most hospital physicians and surgeons is to obtain for their patients, if they can, a floor-space of 100 to 120 square feet, and a cubic space of 1,500 to 2,000 cubic feet, and in this they are right. It must be distinctly understood that a minimum of floor-space must be insisted upon in all cases, not less than -j"^ of the cubic space. '^ ' See Report of the Committee appointed to inquire into the cubic space of Metro- politan Workhouses, 18G7, p. 12. - On this subject see further in Vol. II., chapter on Habitations. VENTILATIOT^-. 1G7 A notion prevails among many people, that cubic space may take the place of change of air, — so that if a larger cubic space be given, a certain amount of change of air may be dispensed with, or less fresh aii- be requii-ed. This is quite erroneous : even the largest space can only provide sufficient air for a limited time, after which the same amount of fi'esh au' must be supphed hourly, whether the space be large or small This is shown by the table on page 149, and may also be mathematically demonstrated by the foi-mula given below.' Even in a space of 10,000 cubic feet per head the hmit of admissible impurity would be reached in a little over 3 hours, after which the same homiy supply of 3,000 feet would be as necessary as in a space of 100 cubic feet." Cubic Space required for Animals. The amount of cubic space for animals has not been very carefully ex- amined. If we followed the rule for men and gave one third of the quan- tity of air supphed per hour, tliis would give for horses and cattle from 3,000 to 7,000 cubic feet. This, however, is probably not necessary, be- cause change of air can be carried on more freely than in human habitations, and animals cannot close ventilators as men will often do. A floor-space of 100 to 120 square feet would probably be sufficient, giving a space of 1,200 to f,800 cubic feet, according to the height of the building. If this could be secirred there is every probability that the results would be excellent. We might put the estimate roughly at 2 cubic feet of space for every ft avds. the animal weighs, — the floor-space being not less than y^ of the cubic capacity. At present, the Army Keg-ulations allow, in new stables, each horse 1,605 cubic feet, and 100 square feet of floor-space ; ' and the means of ventila- tion, as will be presently noticed, ai-e ample. ^ In the Army Horse Infir- maries, the superficial area is to be 137 square feet, and the cubic space 1,900 feet per horse. In the stables of cattle there is often excessive over-crowding, and it is well known that there is a vast amount of disease among them, which, however, is seldom allowed to go far, as they are sent to the butcher. Dr. Ballard, who paid great attention to the cattle plague in Islington, recom- mended that at least 1,000 cubic feet should be allowed per animal. 2. Source of the Air supplied. — In order that the object of the ventila- tion shall not be defeated, it is necessary that the air entering a room 1 pi = ^V * J, where pi = ratio of respiratory impurity at the time (7i), (e)tlie amount of impurity involved during (li), {d) the supply of fresh air, (e) the exponential function, viz., 2.718, and (c) the capacity of the air space. Soon after the first hour the coefficient 6~7" practically vanishes, and with it vanishes also the small influence the cubic space exercises. - For further remarks on this point, see my Lectures on State Medicine ; also "Hvgiene " in Sanitary Record, 1874-75. In a pamphlet by General Morin, Note sur r espace cubique, etc., a table is given that might be misleading, without explanation. It really shows the amount of air necessary to dilute a certain amount of jmpurity evolved" in a certain cubic space, and is sirailar to the table given on page 159 of this work. For continuous ventilation the necessary supply in any ordinary space of the first hour, is a constant quantity. This can be shown by asymptote lines also. See paper by C. Herscher, Socicte de Medecine Publique, in Kevue d'Hygiene, vol. iii., p. 207.— (F. de C.) 3 Report of the Barrack and Hospital Improyement Commission on the Ventilation of Cavalry Stables, 1866, p. 10. •* See Book II., Vol. II. 16S PRACTICAL HYGIENE. shall be pure. The air must he the pure external air, and not he derived from places where it has stagnated and taken up impurities ; if it is drawn along jDassages or tubes, and through louvres or basements, these should be capable of inspection and cleansing. All air-shafts should, if possible, be short and easily cleaned. This is an imjDortant rule, and should lead to the rejection of all plans in which the air-shafts are long and inacces- sible. Several instances have occurred of air being distributed by costly appliances, but drawn from an impure source, or allowed to be contami- nated on its passage. Listead of perforated bricks, there should be slid- ing panels, or hinged flaj^s, so that the tube may be easily reached. In towns it may be necessary to filter the air, which is often loaded with the products of combustion and other impurities. 3. Wai'ming or Cooling of the Ai7\—Th.e air may require to be Avarmed to G0° or G5° Fahr., or cooled according to the season or locality. The warming in cold and temperate climates is a matter of necessity, as, if dis- comfort is caused by cold draughts, ventilation openings are certain to be closed. 4. Distribution. — The distribution in the rooms should be perfect, that is, there should be uniform diffusion of the fresh air through the rooms. The best way of ascertaining this is to compare the amount of air utilized, as calculated from the observed CO^, with the actual movement of air, as measured with the air-meter. If the distribution is good, the two quantities ought not to difl'er materially. Much difficulty is found in prop- erly managing uniform diffusion, and it requires careful arrangement of the various openings. The distributing plans should, if possible, prevent the chance of breathed air being rebreathed, especially in hospitals. As the ascent of respired air is raj^id, on account not only of its tempera- ture, but from the force with which it is propelled upward, the jDoint of discharge for patients in bed should be above. By some it has been argued that it is better that the foul air should pass off below the level of the person, so that the products of respiration may be immediately di'awn down below the mouth, and be replaced by de- scending pure air. But the resistance to be overcome in drawing down the hot air of respiration is so great that there is a considerable waste of power, and the obstacle to the discharge is sometimes sufficient, if the ex- tracting force be at all lessened, to reverse the movement, and the fresh air forces its way in through the pipes intended for discharge. This plan, in fact, must be considered a mistake. The true principle is that stated long ago by D'Ai'cet. In the case of vapors or gases the proper place of discharge is above ; but heavy powders, arising in certain arts or trades, and which from their weight rapidly fall, are best drawn out from below. Sub-Section II. — Means by which Air is set in Motion. These are : — 1st, the forces continually acting in nature, which produce what has been termed natural ventilation. 2d, the forces set in action by man, which produce the so-called artificial ventilation. The division is convenient, but not strictly logical, as the forces which act in natural do so also in artificial ventilation to a certain extent. Natural Ventilation— General Statements. Three forces act in natural ventilation, \\z., diffusion, winds, and the difference in weight of masses of air of unequal temperature. VENTILATION. 169 1. DrFTUSION. As every gas diffuses at a certain rate, viz., inversely as the square root of its density, there is a constant escape of any foreign gas into the atmosphere at large. From every room that is not air-tight Pettenkofer and Eoscoe have shown that diffusion occurs through brick and stone, and Pettenkofer be- Ueves that one of the e\T.ls of a newly built and damp house is that diffusion cannot occur through its walls. But the ordinary plastered and papered walls reduce diffusion to a most insignificant amount. Through chinks and openings produced by imperfect carpentry the air diffuses fast, and Eoscoe found that when he evolved carbonic acid in a room the amount had decreased one-half from that cause in 90 minutes. The amount of purification produced by diffusion under ordinary cir- cumstances is shown by observation to be insufficient ; and, in addition, organic substances, which are not gaseous, but molecular, ai-e not affected by it. As a general ventilating power, it is therefore inadequate. 2. THE ACTION OF THE WINDS. The wind acts as a ^^owerful ventilating agent, and in various ways. If it can pass freely through a room, with open doors and windows, the effect it produces is immense. For example, air moving only at the rate of 2 miles an hour (which is almost imperceptible), and allowed to pass freely through a space 20 feet wide, wiU change the air of the space 528 times in one hour. No such powerful action as this can be obtained in any other way. The wind will pass through walls of wood (single -cased), and even of porous bricks or stone ; and perhaps this will account for the fact that such houses, though cold, are healthy habitations. By covering a brick with wax, or inclosing a portion of a brick wall in an air-tight box, Petten- kofer has shown that the force of the breath will drive air through the brick and will blow out a candle on the other side if the current of air be collected in a small channel. The force required to drive the air through is, however, really considerable, as the air in the brick must be brought into a state of tension. Marcker ' has given the following as the amount of air passing in one hour through a square metre of wall space, when the difference of tem- perature is 1° C. : — Sandstone, 1.69 ; limestone, 2.32 ; brick, 2.83 ; tu- faceous limestone, 3.64 ; and loamy brick, 5.12 cubic metres of air. The little porosity of sandstone depends on the amount of moisture it holds. The moisture, in fact, greatly influences the transit. Plaster, however, ap- pears to arrest wind, if it be true, as stated, that in the interior of some thick walls, after man}' years, lime has been found still caustic ; and Marcker also notices the obstructive effects of mortar. There ar^ two objections to winds as ventilating agents by perflation. (1) The air may be stagnant. In this country, and, indeed, in most countries, even comparative quiescence of the air for more than a few hours is scarcely known. Air is called " still " when it is really moving 1 or 1| mile an hour. The average annual movement of the air in this country is from 6 to 12 miles per hour ; but it varies, of course, greatly from day to day, and in different places. The mean movement at Netley (average of 1 Untersuch. iiber nat. et kiinstliche Ventilation. Gottingen, 1871. 170 PRACTICAL HYGIETs^E. 13 years) is about 10^ miles per hour ; at Aldershot it is 12| iniles per hour (mean of 5 years). (2) A much more serious e^il is the uncertainty of the movement, and the difficulty of regidation. "VMien the velocity reaches 5 or 6 feet per second, unless the air be wann, no one will bear it. The "wind is therefore excluded, or, if aUowed to enter du-ectly through small openings, is badly disti-ibuted. Passing in with a gi-eat velocity, it forces its way like a foreign body through the air in the room, causing di-aughts, and escajDing, it may be, by some opening without proper mixing. A current entering in this way may be measui-ed for many feet. But the wind acts in another way. A moving body of au* sets in motion all air in its vicinity. It di'ives air before it, and, at the same time, causes a partial vacuum on either side of its own jDath, toward which all the aii- in the vicinitv- flows at angles more or less approaching right angles-. In this way a small cun-ent moving at a high velocity will set in motion a large body of air. The wind, therefore, blowing over the tops of chimneys, causes a cur- rent at right angles to itself up the chimney, and the unequal draught in furnaces is owing, in part, to the vaiiation in the velocity of the wind. Advantage, therefore, can be taken of this aspirating power of the wind, to cause a movement of aii' up a tube. The wind, however, may impede ventilation by obstmcting the exit of aii' from any particular opening, or by blowing down a chimney or tube. This is, in fact, one reason of the failure of so many systems of ventilation ; they may work well in a still atmosphere, but the immense resistance of the wind has not been taken into account. At 3 miles an hour-, the pressiu-e of the wind is f of an ounce on each square foot ; it is 1 ounce at 3^ miles ; 2 ounces at 5 miles ; 4 ounces at 7 miles ; -h lb at 10 miles ; and 1 lb at 14 miles. At Xetley the average 2:)ressure is a little over ^ lb j^er square foot. In some systems of ventilation the pei-flating power of the wind has been used as the chief motive agent. In Eg^pt the Mind is allowed to blow in at the top of the house thi'ough large funnels. This plan has been in use from time immemorial This was the case in 'Mx. Sylvester's plan, which was used at Derby and Leicester fifty or sixty years ago. A large cowl, tiu-ning toward the wind, was pLaced in a convenient sjDot near the building to be ventilated— a little above the ground if in the country, or at some height if in a town. The wind blowing do"s^Ti the cowl, j^assed thi'ough an under-gi'ound channel to the basement of the house, and entered a chamber in which was a so-called cockle-stove or calorifere of metal plates or water or steam pipes, by which the air was warmed. It then ascended through tubes into the rooms above, and passed out by a tube or tubes in the roof, which were covered by cowls tiu-ning from the wind. So that the asj^ii-atory power of the aii' was also used. This plan is extremely economical, but the movement of the air is unequal, and it is difficult to regulate it. It has been proposed to place a fan in the tunnel to move the aii- in periods of calm, and the plan then becomes identical in principle, and almost in detail, with the method of Yan Hecke. Mr. Ritchie ' has employed a similar plan in the ventilation of a dwell- ing-house. The air is wai'med in winter to about 70" Fahr. ; every room has a longitudinal openiug over each door, concealed by the architrave, and regulated by valves, and through this the warm aii' from the staircase enters the rooms, and then passes up the chimney, and up outlet au--flues ' Treatise on Ventilation, by Robert Ritchie, C.E., 1862, p. 89. VENTILATIOlsr. 171 placed in the walls, commencing at the ceiling, and ending at the wail- heads under the roof. Dr. Arnott ventilated the Field Lane Ragged School on this principle with excellent effect. In that case, as in aU others, the movement was also in part carried on by the thh'd cause of motion in air, viz., the effect of unequal density of masses of air. In the ventilation of ships, the wind is constantly used ; and by windsails and tubes with cowls turning toward the wind, air is driven between the decks and into the hold. In using the wind in this way, the difficulty is to distri- bute the air so that it shall not cause draughts. This is best done by bending the tubes at right angles two or three times, so as to lessen the velocity, by enlarging the channel toward the opening in the interior of the vessel, and by placing valves to partially close the tubes, if necessary, and by screens of wire gauze. ^ In all cases in which the air of a room, as in a base- ment story, or in the hold of a ship, perhaps, is likely to be colder than the external air, and when artificial means fig. 12.— nia^ of ventilation cannot be employed, the wind should be upc'^stcowi!^^^ taken advantage of as motive agent. The aspiratory power of the wind can be secui-ed by covering air- shafts with cowls such as that shown in Fig. 12, which aid up currents and prevent down di-aughts. 3. MOVEMENTS PRODUCED BY UNEQUAL WEIGHTS OP AIR. The wind itself is caused by this power ; but it is necessary, in discus- sing ventilation, to look upon this as if it were an independent force. If the air in a room be heated by fire, or the presence of men or animals, or be made moister, it endeavors to expand ; and if there be any means for it to escape, a portion of it will do so, and that which remains wiU be lighter than an equal bulk of the colder aii- outside. The outer air wiU then rush into the room by everj' orifice, until the equahty of weight outside and inside is re-estabHshed. But as the fresh air which comes in is in its turn heated, the movement is kept uj) in a constant stream, cold air entering by one set of orifices, and hot air escaping by another. We have now to inquire how the rate of this constant stream of air may be calculated.^ The mode most generally used is based on two well-known laws : — first, that the velocity in feet per second of falling bodies is equal to (nearly) 8 times the square root of the height through which they have fallen ; and, second, that fluids pass through an orifice in a partition with a velocity equal to that which a body would attain in faUing through a height equal to the difference in depth of the fluid on the two sides of the ' As the use of perforated zinc plates and of wire-gauze is very common in ventila- tion, it is necessary to bear in mind that these screens very soon get clogged with dirt. In all cases they should be so arranged as to be easily inspected and cleaned ; and it should be a matter of routine duty to see that they are constantly kept clean. It should also be understood that the delay by friction through the fine wire-gauze is exceedingly great. ^ Many of these points are given in Hood's Treatise on Warming and Ventilation, and in Wolpert (Principien der Vent, und Luftheizung), and a,re also discussed in Peclet (Traite de la Chaleur, third edit.), and by General Morin (Etudes sur la Ventila- tion, Paris, 1863, t. ii.), to which reference is made for those who wish to enter mto the mathematical part of the inquiry. 172 PRACTICAL HYGIENE. partition. ' The press\ire of air upon any surface may be represented by the weight of a cohimn of air of uniform density of a certain height. Thus the pressure of the atmosphere at the surface of the eiu'th is nearly 15 ft* on the square inch, and this would be the weight of a column of aii- of about 5 miles in height. Aii*, therefore, rushes into a vacuum with a velocity equal to that which a hea\-y body would acquire in falling from a height of 5 miles, ^iz., 1,304: feet per second. But if, instead of rushing into a vacuum, it rush into a chamber in which the air has less pressiu-e than outside, its velocity vnR be that due to a height which represents the difference of pressui'e outside and inside. In ordinary cases this difference of pressure cannot be obtained by dii-ect observation, but must be inferred from the difference of temperature of the outer and inner aii". Aii' is dilated one part in 491 of its volume for every degree of Fahrenheit (or 1 in 273 for every degi'ee of centigrade) that its temperature is raised, consequently the difference of pressui'e outside and inside will be as follows : — The height from the aperture at which air enters to that fi"om which it escapes, multiplied by the difference of temperature between outside and inside, and divided by 491. If the height be 20 feet, and the difference of temperature 15 degrees, we 20 X 15 have the height to produce velocity of inflowing current = .„.. — = 0. 61 of a foot, and the velocity = 8 V^=:8 x .781 = 6.248. This, however, is the theoretical velocity. In j)ractice an allowance must be made for friction of ^th, id, or even ^, according to circumstances. The deduction of ifh would leave 4.686 linear feet per second as the actual velocity. If this be multiplied by the area of the opening, in feet, or decimals of a foot," the amount of air is expressed in cubic feet per second, and multiplying by 60 will give the amount per minute. A table is given at page 194, in which this calculation has been made for all probable temperatures and heights ; but it must be remembered that the movement is greatly influenced by the wind. This cause of movement is, of course, constantly acting when the tem- perature of the air changes. It will alone suffice to ventilate all rooms in which the air is hotter than the external air, but will not answer when the air to be changed is equal in temperature to, or colder than, the exter- nal air. As its action is equable, imperceptible, and continuous, it is the most useful agency in natural ventilation in cold climates, in inhabited and warm rooms ; and in all habitations arrangements should be made to allow it to act. As the action increases with the difference of temperature, it is most powerful in winter, when rooms are artificially wanned, and is least so, or is quite arrested in summer, or in hot climates, when the internal and external temperatures are identical. 4. LOSSES PRODUCED BY FRICTION FROM VARIOUS CAUSES. This aspect of the question has hardly received the attention it de- serves, and its neglect is apt to lead to failure and disappointment. The chief causes of loss are the following : — ' Tliis is freqiaently called the rule of Montgolfier. The formula is r =y/2gli ; q beine the acceleration of velocity in each second of time, viz., 32.18 feet, and H the height of the descent. - It will be found alwavs easier to take the area in decimals of a foot instead of inches ; biat if it be taken in inches, multiply the linear discharge by the number of square inches, and divide by 144. VENTILATION. 1 73 1. Length of Tube or Shaft. — Here with equal sectional areas the loss is directly as the length, so that if "\ve take a shaft of 30 feet as a standard, a shaft of 40 feet long "would have an increased friction of one-third. 2. Size of Opening. — For similar sections the fi'iction is inversely as the diameter. Thus for two openings, respectively 1 and 2 feet in diame- ter, the fiiction at the smaller opening will be twice that of the larger. In this way dividing ujd an ojDening into a number of smaller openings, the aggregate of which is equal to the original opening, jiroduces a loss by friction in the direct ratio of the diameters. An opening of 1 square foot divided into four openings of {- of a square foot loses in the ratio of 1 : ^, being respectively the diameters of the openings. "When the shapes of the openings are noL similar, the ratio may be stated as that of the square roots of the areas. Thus 1 square foot divided into nine openings, each equal to \ of a square foot, will lose in the ratio of 1 : ^, the square roots of the respective areas.' 3. Shape of Opening. — A circular opening may be taken as the stand- ard, that being the figTU'e which includes the greatest area within the smallest periphery. The loss sustained from any other shape being used will be proportionate to its difference from a circle enclosing a similar area. Thus, if we have two openings, each of 1 square foot area, the one being a cii'cle and the other a square, the length of periphery of the latter will be 4 square feet, of the former 3-J- ; therefore the velocity of the cur- rent through the square opening will be -\^ or -^- of that through the cir- cular opening.^ 4. Angles in the Tube or Shaft. — This is a most serious cause of loss. The exact formida has not been distinctly determined, but it may be accepted, as in accordance with experiment, that every right angle dimin- ishes the current by one-half, so that two right angles in a tube would re- duce it to 4-, and so on.^ Yet it is no uncommon thing to find tubes and shafts bent recklessly at numerous angles to fit a cornice or architrave, to save expense and appearance. 5. The presence of dust, soot, or dirt of any kind seriously interferes with the current, but this may of course be obviated with a moderate amount of care and attention. It is obvious that attention to the above points is necessary to obtain success in any scheme of ventilation. To take an examj^le ; let us sup- pose a straight shaft 30 feet long, sectional area circular, of 1 square foot, — the current through this giving a sufficient amount of air for the pur- pose required. Let it be necessary to produce a similar amount of ven- tilation in another place, but to use smaller shafts, square in section, area of each ^ of a square foot, — each shaft being 40 feet long, and having one right angle in its coui'se ; what would be the relative amoimts of air available, other things being equal ? Taking the circular shaft, we have length of shaft 30, length of periphery Sh, total 331 = friction. In the four smaller shafts we have length 40, length of periphery of each 2, which multiplied by 4 = 8, total 48 : the right angle doubles the friction, so that ^ See General Morin's Observations. - For a table of friction due to form of sectional area, see " Hygiene," in Sanitary Record, 1875, by Dr. F. de Chaiimont. ^ The formula expresses tbe condition approximately between 0° and 90'; 1 -h sin-5 but 1 -{- cos e .g of more general application, including any angle between 0' and 180". In either case 90° shows a loss of one-Tudf. 174 PRACTICAL HYGIENE. 48 X 2 = 96 as compared to 33^. Thus the result would be nearly as 3 to 1 in favor of the single shaft. It would be obviously necessary to treble either the number of the smaller shafts or the size of each of them. It is advisable generally to widen shghtly the openings of shafts, es- pecially if they ai-e of small diameter, as the evu-reut tends to be contracted and obstructed at that point. At every change of dii'ection the same thing- takes place. Hence the desirability of rounding off angles as much as possible, where they cannot be altogether avoided. ' It is generally best to have the sections of shafts circular or elliptical instead of rectangular, for not only is there less loss by friction originally, but there is less chance of lodgement of dust, etc., and they can be more easily and thoroughly cleaned. 5. PEACTICAI, APPLICATION OF THE GENERAL STATEMENTS OF NATURAL VENTILATION." 1. No particular arrangements are necessary to allow diffusion to act, except that there shall be communication between two atmospheres. 2. To obtain the perflation of the wind, windows should be placed, in all cases Avhere it can be managed, at opposite sides of a room. The windows should open at the top, and in case the wind has a high velocity, means should be taken to distribute it. This can be done by sloping the window inward when it opens, or a board may be placed obliquely upward from the top sash of the window, when it opens in the usual way ; then the air striking against the board is thrown up toward the ceiling. Or, wu-e-gauze may cover the space left when the window is open. The velocity of the Avind is checked by the gauze, and the current is minutely divided. The gauze, however, must be kept clean. Various plans have been proposed by different persoos. The panes of glass may be made double, spaces being left at the bottom of the outside pane and at the top of the inner one, so that the wind is obliged to pass up between the two panes before it enters the room. Or, the lower sash being raised, and a piece of wood placed below it, the air is allowed to pass through the space left between the upper and lower sashes (Hinekes Bird). Or, glass louvres, which can be more or less closed, are placed in one of the j^anes of the window ; or a number of holes are obliquely bored thi'ough the panes, through which the air may pass up toward the ceiling before it intermixes with the air of the room. In Lockhead's ventilator there is a frame over the glass Iou-stc, with a regulator in the centre. In Cooper's ventilator a movable plate of glass can be brought by a movable handle over the opening. StaUard has proposed to ventilate workshops and factories by having a double ceiling ; the lower ceiling is to be made of zinc or oiled paper, per- forated with very numerous srnaU holes ; and the space between the two ceilings is to be fi'eely open to the air on all sides ; thus there would be almost open-air breathing, as the communication with the external air would be constant and at all parts of the room. Besides windows, special openings may be provided for the wind to ' On this question see Wolpert, Theorie u. Praxis der Ventilation u. Heizung (1879), p. 210 et seq. " A very good account of the various plans in natural ventilation will be found in Mr. Edward's work, On the Ventilation of Dwelling-Houses, 1868, in which figures of the plans are given; see also Eassie, " Dictionary of Sanitary Appliances, " Sanitary Kecord, 1880-8i. VENTTLATIOI^f. 175 blow through, as in the plans ali*eacly referred to of Stir. Sylvester and Dr. Arnott. In all warm chmates, where no chill can be produced by wind, it is a good plan to make the walls entii-ely pervious. Nothing can be better than the ventilation of the bamboo matted houses in Burmah. The wind blows through them, but it is so broken up into cun-ents that it is not in the least unpleasant. Even in colder parts of India, the upper pai-ts of the walls might be made thus pervious, provision being made to cover them, if necessary, in the cold season. Cowls have been a good deal recommended as aids to ventilation, but the labors of the Committee of the Sanitaiy Institute of Great Britain, though not yet completed, have shown that the majority of them have no superiority over the open tube. The only form which seemed faii'ly good was the common lobster-backed cowl. For general use, however, this would requii-e to revolve, and this is objec- tionable, as all revohing an'angements are hable to get out of order. A fixed cowl, consisting merely of a cone as a cap and a similar flange roimd the rim of the pipe, insures a fairly con- stant up draught (Fig. 12), A reversed arrangement (Fig. 13) insures a constant down draught. Another plan for utilizing the action of the wind is by the use of " Ellison's conical bricks," which are pierced with conical holes, about ^\ of an inch diameter externally and 1^ in. inter- nally, depth 4^ in. The wind blomng on them is so distributed as to be imj^erceptible as a draught in the room. ^>,g -^g _jjj_ 3. The movement produced by the difference of weight of agram of a unequally heated bodies of air will, of coiarse, go on thi'ough ct/.sz tube, open windows and doors and through all the contrivances just ^^ith trumpet • TT-. • TTT -T T -I mouthandin- mentioned. But as m cold chmates "onndows and doors must verted coni- sometimesbeshut, no room of any kind should be ^rithout addi- ^'^^'^^p- tional openings, which may permit this movement h'om uneqaal tempera- tiu'e to go on. The great difficulty here is to exclude the action of the wind ; and, in fact, it is impossible to do so ; but, as far as possible, the openings should be protected from the perflating influence of the wind, so that only its aspii-ating force should be acting. They should be capable of being lessened in size, when the difference of the external and internal temjoeratures is gxeat. As long as there are openings, movement will go on ; and it does not really matter, as long as there is proper distribution, where the air comes in or goes out, or whether its direction is constant. In fact, it scarcely ever is constant, so liable is the direction to be altered by winds, by the action of the srm heating one side of a room, by the une- qual distribution of heat in the room, etc. Still it seems desirable, as far as it can be done, to make such arrangements as shall give the movement of air a certain dii-ection ; and therefore, in most systems, some of the openings are intended for the admission of fresh air, and are called inlet, entrance, or adduction openings ; others are intended for the discharge of impure au- — and are termed outlet, exit, or abduction openings. Total size of all the Special Openings, ichether intended for Inlets or Outlets. — As the movement of air increases with temperature, the size of the aper- tures can only be fixed for a certain given temperature ; and as the efflux of hot air increases with the height of the column (supposing the tempera- ture is equal thi'oughout), a difterent size has also to be fixed for diiferent heights. This causes a clifficvdty in fi:xiag the proper size for ventHatiag openings 176 PRACTICAL HYGIENE. in the case of natural ventilation, as the conditions are so variable. The theoretical size for any requu'ed change of au-, supposing the conditions were constant, may be obtained from the table at page 194, which is cal- culated from Montgolfier s formula, with a deduction of ^th for friction. Thus, say that the height of the heated column is 20 feet, and the dif- ference of temperature between the air in the room and that outside is 20° F., the huear rate of discharge as stated by the table (allowance being made for friction) is 322 feet jDer minute, or 19,320 feetj^er hour. If the opening were 1 square foot this would give 19,320 cubic feet per hour. But if 3,000 cubic feet per hour are wanted for one person, the orifice of 1 square foot, or 144 square inches, is too large, and must be lessened in the propor- 3000 X 144 tiou of 3,000 to 19,320 ^,. .j^-,,. = 22 square mches (round numbers), i.e., reduced to 22 square inches. There must be a corresponding space for entry, making the total ventilating oj)ening 44 square inches. To take another example ; let us say the heated column is 15 feet, the difference of temperature 10° F., and the required suj)ply for one person 2,000'cubic feet. The table gives the hnear rate as 197 feet per minute, or 11,820 per hour ; an orifice of 144 square inches would then give 11,820, /2,000 X 144 \ and an orifice of 24 square inches would give 2,000 ; I — Ji uon — — ^^j- But if in the above conditions 3,000 cubic feet hourly supply were wanted, the Oldening must be 36 square inches. These examples show how impos- sible it is to fix any size which shaU meet all conditions, even if the influence of v.dnd could be completely excluded, which is impossible. The only way is to adojDt a size which will meet most cases, and suj)ply means of altering the size according to circumstances. In this country, a size of 24 square inches per head for inlet, and the same for outlet, seems calculated to meet common conditions ; but arrangements should be made for enabling this to be lessened or closed in very cold weather, or if the influence of strong- winds is too much felt.' Moreover, the size must be in part deiDcndent on " The following formula proposed by Dr. de Chaumont can be used instead of the table at page 194. It is based on Montgolfier's formula, with the discharge calculated for the hour and for square inches, instead of for the minute and the linear discharge, as in the table. Let h be the height of the heated column of air ; t its temperature ; t' the tempera- ture of the external air; .002 the ratio of expansion of air for each degree of Fahr. ; 100 a constant ; and /'the coefficient of friction. Let D be the delivery required per hour, and * the total inlet and outlet area in square inches. Then to find * : D 100/(v//t{< - t'y+^2) ~ Example : Suppose, as in the text, that the heated column be 20 feet, its mean tem- perature 65°, and that of the outer air 45"', and the required delivery be 3,000 cubic feet per hour ; let/ also equal | or .75. 3000 : =44.4 100 X .75 (y 20(65' - 45'^ x .002) square inches for inlet or outlet, or 22.2 for inlet alone. A converse formula by Dr. de Chaumont may be also useful. If the area of the inlet opening (*') is known, to find the delivery per hour under conditions h, t, and t . 200/ (v/ /r(< - t) xT002) *'= D. The constant 200 is obtained by multiplying 3,600 (seconds per hour) by twice the square root of 16.09 (= 8 nearly), and dividing by 144 square inches. By halving this constant we get the number for both inlet and outlet together. VENTILATION". 177 the size of the room, because in a small room with many people it is im- possible to have the size so great as it wotild. be if each person's area of ventilation opening were 48 squai-e inches, unless some portion of the ah: were warmed. Belative Size of the Inlets and Outlets. — It is commonly stated that, as the heated air exj)ands, the outlets should be larger than the inlets, and the great disproportions of 5 to 4 and 10 to 9 have been given. As, however, the average difference of temperature is only about 10" to 15^ Fahi-. in this country, the dispro2:)ortion is much too gTeat, as a cubic foot of an* only expands to 1.020361 cubic foot with an increase of 10^. Even if the differ- ence is 3U° Fahi'., a cubic foot of au- only becomes 1.061 cubic foot, which is equal to an increase' of about jyth. The difference is so shght that it may be neglected, and the inlets and outlets can be made of the same size. It is desii-able to make each individual inlet opening not larger than 48 to 60 square inches in area, or enough for two or thi'ee persons ; and to make the outlet not more than 1 square foot, or enough for six persons. Distribution is more certain with these small openings. Position and Description of the Inlet and Outlet Tubes. — 1. Inlets. — The air must be taken from a j)ure source, and there must be no chance of any effluvia passing in. As a iiile, the inlet tubes should be short, and so made as to be easily cleaned, other-^ise dii-t lodges, and the au' becomes imj)iu'e. Inlets should not be lai'ge and single, but rather numerous and small (from 48 to 60 inches superfcial), so that the air may be properly distributed. They should be conical or tramjDet-shaped where they enter the room, as the entering an*, after perhaps a slight contraction, spreads out fan-hke, and a slight back curi'ent from the room down the sides of the funnel facihtates the mixing of the entering air with that of the room. To lessen the risk of immediate down-draught they should tui-n upward, if they ai'e placed above the heads of the persons. Externally the inlets should be partly protected from the wind ; otherwise the wind blows through them too rapidly, and, if the current be strong, draughts are felt ; an overhanging shelf or hood outside wiU answer pretty well. Valves must be provided to partially close the openings if the wind blows in too strongly, or if the change of air is too rapid in cold weather. If covered with whe-gauze, it must be frequently cleaned. Sometimes an inlet tube must be can-ied some distance to an inner room, or to the opposite side of a lai-ge room which is unprovided with cross-ventilation. In this case the heat of the room so warms the tube that the wind may be permitted to blow thi'ough it. The j)osition of the inlets is a matter of some difficulty. If there are several, they should be, of course, equally distributed through the room, so as to insure proper mixing of the air. They should not, however, be placed too near an outlet, or the fi-esh air may at once escape ; theoretically, their proper place of entrance is at the bottom of the room, but if so, the air must in this climate be warmed ; no person can bear the cold ah* flow- ing to and chilling the feet. The au- can be warmed easily in various ways, viz. : — {a) The air may pass through boxes containing coils of hot- water j)ipes, or (in factories) of steam pipes. This is the best mode of wai'ming. The coils may be close to the outside wall, or in the centre, or in hospitals in boxes under the beds communicating with the exterior au-, and opening into the ward. (6) The au' may pass into air-chambers behind or round grates and stoves, and be there wai-med, as in the present baiTack and hospital grate. Vol. I.— 13 ITS PRACTICAL HYGIENE. contrived by Captain Galton ; or as in the Meissner or Bohm stoves of Germam- ; ' or as in the terra-cotta stove, in the Herbei-t Hospital at Wool- wich. (c) The ail- may be -n-armed in a tube passing through the stove, as in Georges calorigen, or by the method of Bond's euthermic stove. If the au" cannot be warmed, it must not be admitted at the bottom of the room ; it must be let in above, about 9 or 10 feet from the floor, and be dii-ected toward the ceHing, so that it may pass up and then fall and mix gi-adually -n-ith the aii* of the room. The 13aiTack Commissioners have adopted this plan with half the fresh ah- brought into a baiTack-room. The other half is wanned. It answers fairly well. In towns or mauufactimng districts the air is so loaded with particlec of coal, or, it may be, other jDOwders, that it must be filtered. Nothing answers better for this than mushn or thin porous flannel, or paperhangers' canvas, spread over the ojjeniug, which then should be made larger. This covering can be moistened if the incoming air be too dry. The tubes proposed by ]\Ii'. Tobin, of Leeds, proride for the introduction of ail' from the outside at the floor level and then up a vertical tube, about 4 feet in height ; this gives a vertical du-ection to the cuiTent, which is re- tained for several feet further before it begins to spread and descend. The action of such a tube is, of course, much affected by the dii'ection of the Mind, and in some instances it is reversed altogether. The method is, however, useful in some cases, 2:>articularly for introducing aii* into places which could only be reached ^ith difficulty by otlier means. It has been tried on a large scale at St. Mary's Hospital, Paddington, with fair success.^ In some fonns (as made by the Sanitary Engineering Company), there is an arrangement for washing the air and arresting impiuities. An ingen- ious contrivance for warming the aii* for the upright tube by means of a gas-jet has been suggested by ]\Ir. Lawson Tait ; it also provides an outlet for foul au-. A modification for bedrooms and other rooms in private houses is also recommended by IMi*. Tobin, -viz., to cut out slits be- tween the sashes of the windows, so that the air enters vertically, even when the window is shut. This is similar in piinciple to other modifica- tions of window ventilation ah-eady refeiTed to, but it is only adapted for compai-atively small rooms, and is quite inapj)licable to a hosjiital ward or the like. 2. Outlets. — The place for the outlets is a most important consideration, as it wiU determine in gi-eat measure the position of the inlets. If there are no means of heating the air passing through them, they should be at the tojD of the room ; if there are means of heating them, they may be at any point. If not artificially warmed, the highest outlet tube is usually the point of gi-eatest discharge, and sometimes the only one. (a) Outlet Tubes uithout Artificial Heat. — They should be placed at the highest point of the room ; should be inclosed as far as possible within walls so as to jorevent the air being cooled ; should be straight and with- perfecth' smooth internal surfaces, so that friction may be reduced to a minimum. In shape they may be round or square, and they may be covered above with some appai-atus which may aid the asjDirating power of the wind, and prevent the passage of rain into the shaft. The causes of down-draught and down-gusts in outlet tubes are these : ' The Germans appear to be now making great use of these ventilating stoves in hospitals, and even in private houses. For a good account, see Roth and Lex, loc. cit., p. 248 et seq. -* See Dr. de Chaumont's Report, op. cit. VENTILATIOlSr. 179 the Tvind forces down tlie air, rain gets in, and, by evaporation, so cools the air that it becomes heavier than the air in the room ; or the air be- comes too much cooled by passage through an exposed tube, so that it cannot overcome the weight of the superincumbent atmosphere ; or another outlet shaft, with greater discharge, reverses the current. Arrangements should be made to distribute the down-draught, if it oc- curs ; flanges placed at some httle distance below, so as to tlu'ow the air upward again before it mixes with the air of the room, or simple contriv- ances of a similar kind, may be used. Valves should be also fixed to lessen the area of the outlet when necessary. If there are several outlet tubes in a room, all should commence at the same distance from the floor, be of the same height (or the discharge will be unequal), and have the same expos- ure to sun and wind. Simple ridge openings may be used in one-storied buUdings with slant- ing roofs ; they ventilate most thoroughly, but snow sometimes diifts in. Rain may be prevented entering by carrj-ing down the sides of the over- hanging ridge for some httle distance. A flange j)laced some little distance below will throw any down-draught toward the walls. (6) Outlets with Artificial Warmth. — The dischai'ge of outlets is much more certain and constant if the air can be warmed. The chimney with open fii-e is an excellent outlet — so good that in dwelling-houses, if there are proper inlets, no other outlet need be made, except when gas is used. When rooms are large, and more crowded, other outlets are necessaiy ; the heat of the fire may be further utilized by shafts round the chimney, opening at the top of the room, or, in other words, by sruTOunding the smoke-flue with foul-au* shafts. Gas, if used, should in all cases be made to warm an outlet tube, both to caiTy off the products of combustion, and to utilize its heat. The best an-angement appears to be to place over the gas-jet a pipe to caiTy off the products of combustion, and to case the pipe itseh with a tube, the open- ing of which is at the ceihng ; the tube carrying off the gas products is hot enough to cause a very considerable cbaught in its casing, and thus two outlet cuiTents are in action, one over the gas, and one from the cehing round the gas-tube. A modification of the lamp proposed in 1846 by ]Mr. Eutter answers very well, and is in use, as arranged by Mr. Eicketts. A good form is also made by Messrs. Sugg. In various other ways the heat of fire and lights may be taken advan- tage of. There will seldom be any difficulty in arranging the inlets and outlets, and in obtaining a satisfactory' result, if these principles are borne in miad, viz., to have the fresh air pui-e, to distribute it properly, and to adopt everj' means of securing the outlets fi'om cold or of artificially waiTaing them, and of distributing the air, which, in spite af all precautions, wUl occasionally jDass down them. In hot climates, when outlet shafts are run up above the general level of the building, it would be of advantage to make them of biick work, and to color them black, so that they may absorb and retain heat. 6. PLANS OF TUBES iJNTD SHAFTS WHICH HAVE BEEN PROPOSED. In most of the j^lans which have been proposed, the inventors have not distinctly seen that the influence of the ^inds and of the movement of air produced by unequal temperatui-es must be carefully distingviished, and, as far as can be done, provided for. 180 PRACTICAL HYGIENE. jy:5£2OTH3aii \ 1. openings at once to the Outer Air for Inlets, the Chimney being relied on for the Outlets or Special Tabes fixed in. — Perforated or air bricks are let into the walls. A usual size is 9 x 3 inches, and the united area of all the several openings in one brick is about 11^ square inches. Another common size is 10x6 inches, with an oj)eu area of about 24 square inches. The Avind blows freely through them, and draughts are produced. The Sheringham valve is a great improvement on this : the air passes through a perforated brick or iron jilate, and is then directed upward by a valve ojDening, which can be closed, if necessary, PiQ 14 by a balanced weight (Fig. 14). The size of the internal oj^ening is, in the usual sized valve, 9 inches by 3, and the area is 27 inches. These valves are usually placed toward the upper part of the room. The wind blows through them, and the movement is therefore variable. They are often outlets ; it will, in fact, depend upon circumstances whether they are inlets or outlets. Very little draught is, however, caused by them, unless with a high wind ; on the whole, they are the best inlets of this kind. An oj)en iron frame of the size of a brick covered with perforated zinc, and with a valve to close it, if necessary, is a still simpler j:)lan, and the air is pretty well distributed. The gauze should be cleaned frequently. Mr. Boyle, of Ijondon, uses a round plate woi'king on a screw, which can be brought nearer or farther from a corresponding opening in the wall ; the air entering strikes on the plate, and then spreads circularly over the wall, and is then drawn gently into the room. Some in- genious forms of inlet and outlet have also been introduced by Mr. Richard Weaver, C.E., and by Messrs. Ellison, of Leeds. 2. Tubes of Different Kinds. — A single tube has been sometimes used for inlet and outlet, a double current being established. This is, how- ever, a rude plan, as there are no means of dis- tributing the air, and as the intermingling of Fio. 15. the ciuTent and the friction of the meeting air is sometimes so great as to impede, or even for a time stop, the movement. ' To avoid these inconveniences, Watson pro- posed to place a partition in the tube (Fig. 15), and Muir suggested the use of a double partition running from corner to x;orner, so as to make four tubes. He covered his divided tube Avith a lou\Te so as to make use in some degree of the aspiratory jjower of the wind on one side. In these tubes, accidental circumstances, such as the sun's rays on one side, the wind, the fire in tlie room, etc., will determine which is outlet and which is inlet. They are so far better than the single tube, that the partition divides the currents and prevents friction, but there is the same irregular action and changing of currents from accidental circumstances, so that the . ^ : ■■ -\ ' The model ofWatson's ventilating tube is well adapted for showing'how opposing currents of air block each other. Although the tube is of good size,' a candle placed in a bell glass, into the top of which the tube is fixed, soon goes out ; a partition being then inserted into the tube the currents are at once divided — one passes up, one down, the sides of the tube, and the candle biarns again. VENTILATIOTSr. 181 direction of the currents and tlieii* rate are variable. The distribution of the enteiing air is also not good. Much better than these plans is M'Kinnell's circular tube. It consists of two cylinders, one encircling the other, the area of the inner tube and encii'cling ring being equal ^ The inner one is the outlet tube ; it is so be- cause the casing of the other tube maintains the temperature of the air in it ; and it is also always made rather higher than the other ; above it is protected by a hood, but if it had a cowl, lihe that at Fig. 12, it would be better. The outer cylinder or ring is the inlet tube ; the air is taken at a lower level than the toj^ of the outlet tube ; when it enters the room, it is thrown up toward the ceiHng, and then to the walls by a flange placed on the bottom of the inner tube ; the air then passes from the walls along the floor toward the centre of the room, and upward to the outlet shaft. (Figs. 16 and 17.) Both tubes can be closed by valves. If there is a fire <*?> Fig. 16. Fig. 17. in the room, both tubes may become inlets ; to prevent this the outlet tube should be closed ; if doors and windows are open, both tubes become outlets. The movement of air by this plan is imperceptible, or almost so ; it is an admirable mode for square or round rooms, or small churches ; for very long rooms it is less adaj^ted. The tube is made of aU sizes, from 6 inches in diameter, which is adapted for a sitting-room, up to 7 or 8 feet, which is the size used in some churches. The two tubes, after passing out of the room, may be taken in different directions, care being taken that the inner tube is always the longest, and, if possible, with the fewest curves. If the two tubes can be kept together for some distance, an advantage would perhaps be gained, as the hot aii* would transmit a portion of its heat to the ah- in the outer tube, which would enter the room at a higher tem- perature than would othen\dse be the case ; some loss of movement would result, but this would be triflinof. Dr. Arnott's chimney ventilator is a valved opening at the top of the room, leading at once into the chimney, and, like Dr. Chowne's siphon, has ' It would be advisable to make the outer ring larger, seeing that the friction to he overcome is about double that of the inner tube. 182 PRACTICAL HYGIENE. the gi'eat advantage of di-awing the air from the toj^ of the room : it has heen, and is, much used, but has the inconvenience of occasionally allowing the reflux of smoke. Mr. Boyle has altered this chimney ventilator by hanging small talc plates at a certain angle ; a very sUght pressure closes them and prevents reflux. Of these various plans, M'Kinnell's should be chosen, if the air must be admitted at the top of the room ; and they are well adapted for guai'd- rooms, cells, and rooms of small dimensions, when it is desii-ed to have the ventilating appai-atus out of reach. Watson's di%-ided tube can also be used, but is less useful than the others. System of Ventilation adopted in the Army. On Home Service. — The official plan now in use was arranged about twenty-two yeai's ago by the Baii-ack Improvement Commission ; it is ap- pHed in most of the new baiTacks, and in several old ones. It has answered extremely well, and it is much to be desired that it should be carried out evervwhere. It is based on the plan of natural ventilation, and consists of— 1. One outlet shaft, or more if required, proceeding from the highest point of the room ; the exact position in the room varies ; it is sometimes at the comer, or at one side, according to cii'cumstances. This shaft is carried straight up inside the wall, and about 4 to G feet above the roof, and is covered \^-ith a louvre. It is made of wood, is very smooth inside, and is provided with a flap for paitly closing it below. Its size is regulated by that of the room and by the number of inmates, but it is not made larger than 1 square foot ; if more outlet is requii-ed, another shaft is put up. The relation between its size and that of the room varies ■nith the position of the room. In a thi-ee-storied baiTack the nile is as follows : — 1. On the ground floor, 1 square inch of section area of outlet shaft for eveiy 60 cubic feet of room-space, or for each man 10 square inches of area. 2. On the first floor, 1 square inch for every 55 cubic feet of room- space, or for each man 10.9 (say 11) square inches. 3. On the second floor, 1 square inch for ever}' 50 cubic feet of room- space, or for each man 12 squai-e inches. In a one-storied ban'ack the amount should be the same as the second floor, or, in other words, 12 men would have a shaft of 1 square foot. In addition, there is the chimney, which gives a section area per head of about six square inches. The total outlet area per man is therefore 16 to 18 inches, according to cii'cumstances. 2. Inlets. — The amoiuit of inlet is a trifle more than 1 square inch to every 60 cubic feet of room. Half the inlet air is wai*med in all the new bai-racks and many old bar- racks by being taken through air chambers behind thefii-e (Galton's stove) (area of tube = 6 square inches per head), and the other half comes direct fr'om the outer afr into the rooms thi'ough Sheiingham valves. Ai'ea of outer opening = 5 square inches, making altogether 11 square inches of inlet opening per man. The cold air inlets (Sberingham valves) are placed at the sides near the VENTILATION". 183 ceiling, about 9 feet from the floor, and are not opposite each other. Fig. 18 shows a usual arrangement. The outlet space is thus seen to be rather larger than the inlet, but as the doors and windows seldom fit close, it is probable that practically this is of little consequence. The movement of air through these openings is tolerably regular — ^a regular as it ever can be in natural ventilation. The discharge of air through the chimney and outlet shaft averages about 1,200 cubic feet per head per hour, with a range from 700 to 1,500 or 1,600, according to the amount of fire, the warmth of the room, and the movement of the ex- ternal air. The usual upward current through the outlet shafts at night, is from 3 to 5 feet per second. Sometimes the chimney and outlet counteract each other a little ; a strong chimney draught may stop the current in the outlet shaft, but there is seldom any down-draught unless rain beats into the louvre and trickles down the inside of the shaft. The ven- tilation of barracks has been wonderfiilly improved by this plan, and the average CO^ ranges from .7 to 1 per 1,000 volumes, according to the rapidity of movement of the air. The hospital system is precisely the same, except that the dimensions are nearly doubled. 3Iediterranean Stations. — The same system is directed to be carried out whenever practicable at Malta and Gibraltar, only the sizes of the inlets and outlets are trebled ; for example, there is 1 square inch of outlet for every 20 cubic feet of space instead of 60 as at home ; great care is ordered to be taken to remove all outside obstacles to the movement of the wind. The Tropics and India. — The same system in principle is now directed to be used in India. Fig. 18. SECTION m ARTIFICIAL VENTILATION. Artificial ventilation is accomplished in two ways : either the air is drawn out of a building or room (the method by extraction), or it is driven in, so as to force out the air already in the room (the method by propiilsion). Sub-Section I. — Ventilation by Extraction. This is produced by the application of heat, so as to cause an upward current, or by the steam- jet, or by a fan or screw, which draws out the air. 1. Extraction by Heat.^-The common chimney is a well-known example of this. There is a constant current up the chimney, when the fire is burn- ing, in proportion to the size of the fire and of the chimney. The usual current up a common sitting-room chimney, with a fair fire, is, as measured by an anemometer, from 3 to 6 feet per second, A very large fire wiU bring it up to 8 or 9 feet. The movement caused by a kitchen or furnace fire is, of course, greater than this. If the area of the section where the anemometer is placed be known, the discharge can be stated in cubic feet. 184 PRACTICAL HYGIENE. '\Mieii the air enters equably, and is well distributed, the movement of air is from the inlets gently toward the fireplace ; there is also said to be a movement, from above the fireplace, along the ceiling and down the walls, and then along the floor to the chimney.' In the wards of Foi-t Pitt the cuiTent, with a good fire, is about 3^ to 4^ feet per second ; and as the section area of the thi'oat is .5 square foot, the average discharge is about 7,200 cubic feet per hour. In the barracks of Chiitham, Dr. Fytfe found the discharge by the chimney to be 9,080 cubic feet per hour (average of six observations). In the barracks at Gravesend, Messrs. Hewlett, Stanley, and Reid found the discharge to be 6,120 cubic feet per hour (average of twenty obsen-ations). At Chelsea New BaiTacks, with a fire alight but low, the velocity was 14.6 per second, or :2l,038 cubic feet per horn- ; and, with the fire out, 11.9 per second, or 17,088 per hour.'' In the experiments of the Barrack Commissioners,^ the chimney discharge ranged from 5,300 to 16,000 cubic feet per hour, the mean of twenty-five experiments being 9,904 cubic feet. Even in summer, without a fire, there is genei-ally a good up-current.* It may be concluded that, with an ordinary fire, a chimney gives a discharge sufficient for foui- or five persons. If then, moi-e than this number of persons habitually live in the room, an- other outlet must be provided. As the cun-ent up the chimney is so great when the fire is lighted, all other openings in a room, if not too many, become inlets ; and, in this way, down-draughts of air may occur from tubes intended as outlets. There is no remedy for this ; and if too much enters, the outlets must be more or less closed. If the room be without openings, so that no air can reach the fu'e, air is drawn down the chimney, and a double current is estabhslied, by which the fire is fed. The down-cui-rent coming in puffs is one cause of smoky chim- neys, and may be at once cured by making an inlet. The chimney and fire is a type of a number of other similar modes of ventilation by extraction. The ventilation of mines is carried on by Hghting a fire at the bottom of a shaft (the upcast or return shaft), or half a shaft, if there be only one. The air is di-awn doAvn the other or downcast or intake shaft, or half the shaft, and is then made to ti-averse the galleries of the mine, being directed this way or that by partitions. Double doors ai"e used, so that there is no back or side iiish of the air. The cuiTent passes thi-ough the upcast-shaft at the rate of from 8 to 10 feet per second ; it flows thi-ough the main galleries at the rate of from 4 to 6 feet per second, or even more, and from 1,000 to 2,000 cubic feet per liead per hour are supphed in good mines. In fire- damp mines much more than this is given, even as much as 6,000 cubic feet per man per hour-. ^ If the quantity of air be reduced too low there is a serious diminution in the amount of work performed by the men. A horse is allowed 2,466 cubic feet, and a hght 59 ciibic feet per hoiu-. All these quantities are too small. It may easily be conceived how skilfully the air must be directed, so as to traverse the most remote workings ; in some mines a portion of aii- makes a cu'cuit of from 30 to 40 miles before it can ' Reid and Stewart, quoted by the Barrack Commissioners. '^ Dr. F. de Chaumont's Reports, Army Med. Reports, vol. ix. ' Report, 1861, p. 73. ■• In August, 1869, I found at Fort Elson the velocity to be on one occasion 7.5 per second, and at Gosport Xew Barracks, 8.4. The velocity generally ranges from 1^ foot to 3 feet per second, althoiigh it is often more. — (F. de C.) ' Proceedings of Civil Engineers, vol. xii., p. 308. VENTILATIOlSr. 185 arrive at the upcast-shaft. The size of the shafts in a colliery varies from 8 to 11 or 12 feet in diameter ; the sectional area of a shaft of the former size would be 50 square feet. A current of 8 feet per second in the up- cast-shaft would give a dischai'ge of 1,440,000 cubic feet per hour, which would give 720 men 2,000 cubic feet per hour. The sectional area and height of the extracting shaft, and of the tubes running into it, have been fixed by Peclet ; the principle is to give to the shaft the greatest height which can be allowed, and the largest section which can be given,' without permitting the temperature of the contained air to fall so low as to be unable to overcome the resistance of the atmos- ■phere at the top of the shaft, or the action of the winds. ^ In large buildings the same plan is often used ; a chimney (cheminee d'appel of the French) is heated by a fire at the bottom, and into the bot- tom of this shaft, close to the fire, run a niimber of tubes coming from the different rooms. Several Pi'euch and Enghsh hospitals, and many other buildings, are ventilated in this way. Dr. Reid for some years ventUated the Houses of Parhament in the same manner, and so powerful was his up-draught, that he could change the entire air in the building in a few minutes. In dweUing-houses it has been proposed to have a central chimney, into which the chimneys of all the fires shall open, and to sun-ound this with au'-shafts connected with the tops of the rooms. It is supposed that if other inlets exist, there will be a current both up the chimney and up the shaft mnning beside it. In all these cases it requires that the workmanship shall be very exact, so that air shall not reach the extracting shaft except through the tubes. It is now more than a hundred and twenty years ago since Dr. Mead brought before the Royal Society Mr. Sutton's plan of ventilating ships on the same principle. Tubes running from the hold and various cabins joined together into one or two large tubes which opened into the ashpit beneath the cooking fires. If the doors of the ashjoits were kept closed, the fires drew the air rapidly from all parts of the ship. Unfortunately, this plan never came into general use. The same plan was adopted by Dr. Mapleton for the ventilation of the hospital ships employed in the last (1860) China War. The arrangement requires some watching to prevent careless cooks fi'om allowing air to reach the fires in other ways. On the same principle some men-of-war are now being ventilated.^ The funnel and upper part of the boiler, and, as far as possible, all the steam apparatus, are inclosed in an ii'on casing, so that a space is left of some 3 or 4 feet between the casing and the funnel. When the fires are hghted, there is of course a strong cuiTcnt up this space, and to supply this the air is drawn down through all the hatchways toward the f menace doors. The temjDerature of the stokehole is reduced from 130° or 140° Fahr., to 60° and 70° ; and the draught to the fires is so much more perfect, that more steam is obtained from the same amount of fuel. This plan, devised by Mr. Baker, has been ingeniously apphed by Admiral Fanshawe, late super- intendent at Chatham dockyard, to the ventilation of every part of the ship where there are no water-tight compartments. Edmonds' plan com- ' De la Chaleur, 3d. ed., 1861, t. iii., p. 66 et seq. ■-* The amount of the resistance given to the movement of air through the tubes leading to the sh?it, and in the shaft itself, can be calculated from the formula given by Peclet at p. 47 (t. iii.), but which it is unnecessary to introduce here. 3 In the new ironclads it is f oimd necessary to use large fans driven by special en- gines to effect thorough change of air below. 186 PRACTICAL HYGIENE. bines with this the ventilation not only of the hold, but of the timbers of the ship. Sometimes, instead of a fire at the bottom of the chimney, it is placed at the top ; but this is a mistake, as there is a great loss of heat fi-om the im- mediate escape of the heated ah* ; the proper plan is to heat, as much as possible, the whole column of air in the chimney, which can only be done by placing the fire below. Sometimes, as in Jebb's method for cell-prisons, the shaft is too shoi-t for the work it has to do. Frequently, instead of, or in addition to a fire, heat is obtained in the shaft by means of hot-water or steam pipes. This plan has long been in use in England,' and has since been introduced into France, and improved by M. Leon Duvoir. Wai'ming, as well as ventilation, is accomplished by this method, which is in action at the Hospitals Lariboisiere (in one-half) and Beaujon. It appears to be at once effectual and economical, though it has been shaii^ly criticised by Grassi and Peclet. After a veiy long in- vestigation into the merits of all rival plans, it was adopted by a French commission for the warming and ventilation of the Palais de Justice at Paris, and has since been adopted in other pubUc buildings, chiefly from the advocacy of General Morin.^ The plan at the Hospital Lariboisiere is simply this : an extracting shaft contains in the lower part a boiler, from which two spiral hot-water tubes run up to the requisite height in the shaft, and then, lea%T.ng it, pass downward and enter the wards, in which they are coiled so as to form hot-water stoves, and then leaving the wards, they pass dowTi aud re-enter the boiler. There is a continual circulation of hot water, and in the shaft there is necessarily an upward cun-ent of air. But as the air is continually increasing in temperature toward the jDoint of discharge, there is a loss of power, just as in the case of the fire being- placed at the top instead of the bottom of the shaft. From the bottom of the wards air-conduits or tubes run into the extracting shaft, and thus the vitiated air is drawn out of the wards. The fresh ah' is admitted du-ectly from the outside into the wards, and is warmed by being admitted through the coils of the hot-water tubes. In the summer the water is shut off from the water-stoves, but the temperatiu-e of the extracting shaft is still maintained. It is certainly time that the ventilation by this plan is irregidar ; ^ and also, that in the Hospital Lariboisiere, a much greater quantity of air passes through the extracting shaft than enters thi-ough the hot- water stoves. In the summer, when there is ventilation without warming, the outflow of air from the wards varied from 84.4 cubic metres (2,980 cubic feet) to 55.3 cubic metres (1,952 cubic feet) per head per hour.^ In the winter, when there are both ventilation and warming, the out- flow of air fi'om the wards was 82.2 cubic metres (or 2,902 cubic feet) per head per hom*. Of that amount, only 35 cubic metres (1,235 cubic feet) entered by the water-stoves, the rest came in by doors and windows and other openings — an objectionable point, as the air might press in from the closets. Yet, in spite of this, the temperature was maintained pretty well up to the hmit fixed in the agreement, viz., 15"^ Cent, or 59° Fahr. ' It is in use in the Circuit Court-House in Glasgow, and in the Police Buildings at Edinburgh (Ritchie), and in many other buildings. ^ Two excellent reports have been made by this Commission, of which General Morin was reporter. Their titles are given further on. Much information is also given in General Morin's work on ventilation. Etudes sur la Ventilation, Paris, 18G3, 2 vols. ^ Peclet, Traite de la Chaleur, 1861, t. iii., p. 267. •* Grassi, op. cit., pp. 35-37. VENTILATION^. 187 Oil lias been used in some cases instead of "svater, for circulating in the heating appai'atus. Very frequently, instead of a fwe or hot-water vessels, lighted gas is used to cause a current, and if the gas can be apphed to other uses, such as lightmg, cooking, or boiling water, the plan is an economical one. In theatres the chandehers have long been made use of for this pur- pose. !^L D'Arcet proposed this for several of the old theatres in Paris, and the Commission ' appointed to determine the mode of ventilation to be adopted in the Theatres L^Tique et du Cu-que Imperial, determined, after much consideration, that this plan was the best adapted for theatres. Gen- eral i\Iorin, from numerous experiments, found that 1 cubic metre of gas caused the discharge of 1,000 cubic metres of aii', or 1 cubic foot would cause the discharge of 1,000 cubic feet of au-." The advantage of extraction by heat, especially in. the case of theatres and buildings where gas can be brought into play, ai-e obvious, but the growing use of the electric hght will necessarily modify the arraugements for ventilation. There are some objections to extractions by the fire and hot-au- shaft. (1) The inequahty of the di'aught. It it almost impossible to keep the fire at a constant height. The same quantity of combustible material should be consumed in the same time every day, and the heat should be kept in by large masses of masonry. Still, with these precautions, the at- mospheric influences, and changes in the quality of the combustibles, can- not be avoided. (2) The inequality of the movement from different rooms. From rooms nearest the shaft, and with the straightest connecting tubes, there may be a strong ciuTent, while from distant rooms the friction in the con- duits is so gi'eat that Httle air may pass. This is weU seen in cell prisons, ventilated on Jebb's principle. The gTcatest care is therefore necessary in calculating the resistance, and in apportioning the area of the tubes to the resistance. This plan is, iadeed, best adapted for compact buildiugs. Oc- casionally, if the friction be great, from too small size, or the angular arrangement of the conduits leading to the hot-shaft, there may be no movement at all in the conduits, but a down-current to feed the fire is established in the shaft itself — a state of things which was discovered by Dr. Sanderson to exist in the ventilation of St. Maiy's Hospital in London. (3) The possibUity of reflux of smoke, and perhaps of au', from the shaft to the rooms, is another objection of some weight. (4) The impossibihty of properly controUing the places where fresh air enters. It will flow in. from all sides, and possibly from places where it is impure, as from closets, etc. ; au' is so mobile that with every care it is difficult to bring it under complete control — it will always press in and out at the point of least resistance. 2. Extraction by the Steam-jet. — The moving agent here is the force of the steam-jet, which is aUowed to i^ass into a chimney^ The cone of steam sets in motion a body of air equal to 217 times its own brdk. Tubes pass- ing from different rooms enter the chimney below the steam-jet, and the air is extracted from them by the strong upwai-d current. This plan is best adapted for factories with spai'e steam. It was employed for some time in the ventilation of the House of Lords, but was finally abandoned. 1 Eapport de la Commission sur la Chauffage fet la Ventilation du Theatre Lyrique et du Tlieatre du Cirque Imperial, Rapporteur le General Morin, Paris, 1861. ^ Etudes sur la Vent. , t. ii. , p. 720. 188 PRACTICAL HYGIENE. 3. Extraction by a Fan or Screw. — An extracting fan or Arcliimedean screw has been used to throw out the aii\ Several difiereut kinds have been proposed by Messrs. Combes, Letoret, Glepia, and Lloyd, and have been used in coal-mines in Belgium, and in some of the English mines. At the Abercarn mine, in South Wales, a fan is used of 13| feet diameter ; the vanes, eight in number, are 3 J feet wide by 3 feet long ; at GO revolu- tions per minute the velocity of the au* is 782 linear feet per minute, and 45,00U cubic feet are extracted ; the velocity at the cu-cumference of the fan is 2,545 feet per minute ; the theoretical consumption of coal per hour is 17.4 ft).' 'Mi: Van Hecke formerly used a fan for this pui-pose, in his system of ventilation of buildings, but he has fovmd it better to abandon it, and sub- stitute a propeUing fan. Sub-Section II. — Ventilation by Propulsion. This plan was proposed by Desaguliers, in 1734,'' when he invented a fan or Avheel inclosed in a box. The air passed in at the centre of the fan, and was thrown by the revolving vanes into a conduit leading fi'om the box. In some form or other this fan has been used ever since, and the conduits leading from it are now generally made large, so that the fan may move slowly, and deliver a large quantity of au* at a low velocity. The fan, if small, is worked by hand ; if larger, by horse, water, or steam power. It is largely used in India, under the name of the Thermantidote. The fans are often made with six or eight rays, each caiTying vanes at the end, which should be as close as possible to the enveloj)ing box. In size, the length of the vanes should be more than half the length of the rays ; the number of rays should augment with the diameter of the orifice of access.' The amount of air delivered can be told by timing the speed of revolu- tion of the extremities of the fan per second, or jDer minute ; the eflective velocity is equal to f ths of this, and this is the rate of movement of the air. If the section area of the conduit be known the number of cubic feet dis- charged per second, minute, or hour, can be at once calculated. The power of this plan is very considerable. AVith a fan of 10 feet diameter, revolving sixty tunes per minute, the effective velocity is 1,414 feet per minute. The rate of movement in the main channel should not be more than 4 feet per second ; the conduits must gradually enlarge in calibi'e ; and the movement, when the air is delivered into the rooms, should not be more than 1^ foot per second. At the Hospital Lariboisiere in Paris, it is stated that 150 cubic metres (= 4,296 cubic feet) have been delivered per head per hoiu', in the wards ventilated by the propelhng fan of MM. Thomas et Laurens. It must, however, be remembered, that the later observations of General Morin showed that much of the movement ascribed to the fan was really owing to natural ventilation. This plan is very well adapted for those cases in which a large amount of air has to be suddenly supplied, as in crowded music halls and assembly rooms. St. George's HaU at Liverpool is ventilated in this way. The air ' Ure's Dictionary, 1875, art. Ventilation, vol. iii. p. 1069. ' Course of Experimental Philosophy, vol. ii., p. 564. The wheel was shown to the Eoval Society in 1734 "^ Peolet, be la Chalenr, 3d edition, 1868, t. i., pp. 259, 263. Numerous kinds of fans for propulsion and extraction are figured, and detailed accounts of construction and amount of work are given. VENTILATION. 189 is taken from tlie basement ; is washed by being drawn througb a thin film of water thi'own up by a fountain ; is passed into caloriferes (in the winter), where it can be moistened by a steam-jet, if the difference of the dry and wet bulb be more than four to six degrees, and is then propelled along the channels which distribute it to the hall. In summer, it is cooled in the conduits by the evaporation of water. At the Hopital Necker in Pai'is, and in many other places, the plan of Van Hecke is in use. A fan, worked by an engine, drives the air into smjdl chambers in the basement, where it is warmed by cockle stoves, and then ascends into the rooms above and passes out by outlet shafts con- stinicted in the walls. The system is effective and economical, though it is only just to say that, the use of the fan excepted, it is precisely similar in principle to Sylvester's. The fans employed by ]VIM. Verity, of London, seem to be very power- ful. In addition to the fan, other appliances have been used. Soon after Desaguliers proposed the fan, Dr. Hales employed large bellows for the same pui-pose, and they were used for some time on board some men-of- war, and in various buildings. They were worked by hand ; and probably this, and their faulty consti'uction, led to their being disused. Theii' use was revived and their form modified and improved by Dr. Arnott.' Dr. Arnott showed that Hales lost much poAver by forcing his air through small openings ; and, by some ingenious alterations, made an effective machine. The hydraulic air-pump, sometimes used in mines, is usefiil on a small scale. ^ The punkah used in India is another mechanical agent with a similar though more imperfect action. AMien a punkah is pulled in a room open on all sides, it will force out a portion of air, the jDlace of which will be at once sujDjolied by air rushing in with greater or less rapidity from all points. If the punkah can be moistened in any way, its cooUng effect is consider- able. In Moorsom's jDimkah a wheel timied by a bullock both moves the punkah and elevates water, which then passes along the top of the punkah, and flows down it. The advantages of ventilation by propulsion are its certainty, and the ease with which the amount thrown in can be altered. The stream of air can be taken from any point, and can, if necessai-y, be washed by passing through a thin film of water, or thi'ough a thin screen of moistened cotton, and can be warmed or cooled at pleasure to any degi'ee. In fact, the engineer can mtroduce into this operation the precision of modern science. The disadvantages are the great cost, the chances of the engine breaking down, and some difficulties m distribution. If the air enter thi-ough small openings, at a high velocity, it will make its way to the outlets without mixing. The method requires, therefore, great attention in detail. ' On the Smokeless Fireplace, by Nell Axnott, M.D., F.R.S., etc., 1855, p. 163 ; and in other publications. ^ Ure's Dictionary, 1875, vol. iii. , p. 1064. 190 PRACTICAL HYGIEKE. SECTION IV. RELATIVE VALUE OF NATURAL AND ARTIFICIAL VENTILATION. Circumstances differ so widely, that it is impossible to select one system tn preference to all others. In temperate climates, in most cases, especially for dweUing-houses, baiTacks, and hospitals, natural ventilation, with such powers of extraction as can be got by utilizing the sources of warming and lighting, is the best. Incessant movement of the air is a law of natiire. We have only to allow the air in our cities and dwellings to take share in this constant change, and ventilation will go on uninteiTuptedly without oiu' care. In some circumstances, however, as in the tropics, with a stagnant and warm air ; and in temperate climates in certain buildings, where there are a great number of small rooms, or where sudden assemblages of people take place, mechanical ventilation must be used. So much may be said both for the system of extraction and propulsion under certain cii'cum- stances, that it is impossible to give an abstract preference to one over the other. In fact, it is evident that the special conditions of the case must determine the choice, and we m'ust look more to the amount of air, and the method of distribution, than to the actual source of the moving j^ower. But in either case the greatest engineering skill is necessary in the aiTangement of tubes, the supply of fresh air, etc. The danger of contamination of air as it passes through long tubes, and the immense friction it meets with, must not be overlooked. For hospitals, natural ventilation certainly seems the proper plan. The cost of the various plans will depend entii'ely on circumstances, the nature of the building, the price of materials, coal, etc. On the whole, the plans of ventilating and warming by hot-water jDipes, and Van Hecke's plan, are cheaper than the method by propulsion by means of a large fan ; but the latter gives us a method which is more under engineering control, and is better adapted for hot climates when it is desired to cool the air. CHAPTEE IV. EXAMINATION OF AIR AND OF THE SUFFICIENCY OF VENTILATION. The sufficiency of ventilation should be examined — 1st, By determining the amount of cubic space assigned to each person, and the amount of movement of the air, or, in other words, the number of cubic feet of fresh air which each person receives per hour. 2d, By examining the air by the senses, and by chemical and mechanical methods, so as to determine the presence, and, if possible, the amounts of suspended matters, organic vapor, carbon dioxide, hydrogen sulphide, and watery vapor. SECTION I. MEASUREMENT OF CUBIC SPACE.' The three dimensions of length, breadth, and height are simply multi- plied into each other. If a room is square or oblong, with a flat ceihng, there is, of coui'se, no difficulty in doing this, but frequently rooms are of irregular form, with angles, projections, half-circles, or segments of circles. In such cases the rioles for the measurement of the areas of cu'cles, seg- ments, triangles, etc., must be used. By means of these, and by dividing the room into several parts, as it were, so as to measure fii'st one and then another, no difficulty will be felt. After the room has been measured, recesses con- taining air should be measured, and added to the amount of cubic space ; and, on the other hand, solid projections, and soHd masses of furniture, cupboards, etc., must be measured, and their cubic contents (which take the place of air), deducted from the cubic space already measured. The bed- ding also occupies a certain amount of space ; a soldier's hospital mattress, pillow, three blankets, one coverlet, and two sheets, will occupy almost 10 cubic feet, about 7 if tightly rolled up. It is seldom necessary to make any deduction for tables, chairs, and iron bedsteads, or small boxes, or to reduce the temperature of the air to standard temperature, as is sometimes done. A deduction may be made, however, for the bodies of persons li\ing in the room ; a man of average si^ie takes the place of about 2^ to 4 cubic feet of air (say 3 for the average).^ In linear measurement, it is always convenient to measure in feet and decimals of a foot and not in feet and inches. ^ If square inches are meas- ured, they may be turned into square feet by multiplying by .007, ' For tables of useful measures, see Appendix B, Vol. II. ^ The weight of a man in stones, divided by 4, gives the cubic feet he occupies. Thus a man weighing 12 stones occupies 8 cubic feet. 3 The following table may be found convenient : Inches. 12 11 10 Decimal parts of a foot. Inches. Decimal parts of a foot. Inches. Decimal parts of a foot. 1.00 8 =: 0.67 4 = 0.33 0.92 7 = 0.58 3 = 0.25 0.83 6 = 0.50 2 = 0.17 0.75 5 = 0.43 1 = 0.08 1^2 PEACTICAL HYGIENE. ■R-ci^zs—Area or Superficies. A r ■ 1^ =D' X .7854. /rmo/arcZe ...................... ^^, ^ ^^gg Circumference of circle =D ^ 3.1416. Diximtter of circle ^ ^ Multiply 'the procluct^of^ the Area of ellipse — | \y;o diameters by .7854. ( Half sum of the two diame- Circumference of ellipse = '^ ters by 3.1416. C Squai-e one of the sides, or J. ^^ =} multiply any two sides Areaofasquare | into each other. _ j Multiply two sides perpen- Areaofa rectangle — ^ dicular to each other. _ j Base X h height, or Area of a triangle — ^ Height x ^ base. Fig. I'J. Area of a parallelogram Fig. 20. Any figure bounded by right lines. = Divide into two triangles by a diagonal, and take sum of the areas of the two triangles. = Divide into triangles, and take the sum of their areas. Fig. 21. Area of segment of circle FIG. 22. = To I of product of chord and height add the cube of the height divided by twice the chord. (Ch X H X I) + 2^j^ Cubic Capacity of a Cube or a Solid i?.dfln^/e. -Multiply together the three dimensions, length, breadth, and height. CiT Capacity of a Solid Triangle. -Ai-ea of section (triangle) multiphed ^^ ^Cub^c Capacity of a Cone or Pyramid.-Axe^ol base x i ^eight Cubic Capacity Sf a Dome.-Tv^o-ihird,soi the product of the aiea of the base multipUed'bv the height (area of base x height x 3). Cubic Capacity of a Cylinder.— Ai-eaoi base x height. Cubic Capacity of a Sphere.— T>' x .o-2^G. .,. f ^ „^.no The cubic capacity of a bell-tent may be taken as that of a cone. EXAMINATIOlSr OF AIR AND VENTILATION. 193 The cubic capacity of an hospital marquee must be got by dividing the marquee into several parts — 1st, into body ; and 2d, roof : — 1, Body, as a sohd rectangle, with a half cylinder at each end. 2. Roof, solid triangle, and two half cones. The total number of cubic feet, with additions and deductions aU made, must then be divided by the number of persons living in the room ; the result is the cubic space per head. SECTION II. MOVEMENT OF AIR IN TBE ROOM. The direction of movement must first be determined, and then its rate. 1. DIRECTION OF MOVEMENT. First enumerate the various openings in the room — doors, windows, chimney, special openings, and tubes — and consider which is likely to be the direction of movement, and whether there is a possibility of thorough movement of the air. Then, if it is not necessary to consider further any movement through open doors or windows, close all these, and examine the movement through the other openings. This is best done by smoke disengaged from smouldering cotton-velvet, and less perfectly by small balloons, hght pieces of paper, feathers, etc. The flame of a candle, which is often used, is only moved by strong currents. It may be generally taken for granted that one half the openings in a room will admit fresh air, and half will be outlets. But this is not invariable, as a strong outlet, like a chimnej'', may draw air through an inlet of far greater area than itself, or may draw it through a much smaller area, with an increased rapidity. 2. RATE OF MOVEMENT. The direction being known, it is only necessary to measure the dis- charge through the outlets, as a corresponding quantity of fresh air must enter. By the Anemometer. — This is best done by an anemometer, orairrmeter, of which there are several in the market. The one commonly used is in principle that invented by Combes in 1838 : four little sails, driven by the moving air, tvirn an axis with an endless screw, which itself turns some small-toothed wheels, which indicate the number of the revolutions of the axis, and consequently the sjDace traversed by the sails in a given time, say one minute. M. Neumann, of Paris, modified this anemometer by omitting most of the wheels, and introducing a dehcate watchmaker's spring, which opposes the force of the wind, and when it equals it, brings the sails to a stand-stiU. By a careful graduation (which must be done for each instru- ment), the rate per second is detei-mined, and is indicated by a small dial and index. Mr. Casella, of Holborn, at the suggestion of the late Dr. Parkes, modi- fied and improved this instrument, and adapted it to EngHsh measures. A very beautiful instrument is thus available by which the movement of air can be measured approximatively very readily. Casella's air-meter is thus used : — Being set at the zero point, it is placed in the current of the air ; if it is placed in a tube or shaft, it should bo put well in, but not quite in the centre, as the central velocity is always greater than that of the side ; a point about two-fifths from the sides of the tube will give the mean velocity. The time when the sails begin to move is accurately noted, and then, after a given time, the instnmient is Vol. L— 13 194 PRACTICAL HYGIENE. removed, and the movement, in the time noted, is given by the dial. A coiTection is then made, and the hnear dischai'ge is obtained.' If this lineal' discharge is multipUed by the section-area of the tube or opening (expressed in feet or decimals of a foot), the cubic discharge is obtained. If the current varies in intensity, the movement should be taken several times, and the mean calculated ; and if the tube is so small that the sails approach closely to the cii'cumference, the results cannot be depended on. If jjlaced at the mouth of a tube, it often indicates a much feebler ciu'rent than really exists in the tube. Table to show the Velocity of Air in linear feet per minute. Calculated from Mont- golfkr^s formula ; the expansion of air being taken as 0. 002 for each degree Fahren- heit., and one fourth being deducted for friction. {Round nunibers have been taken.) o a ■« E •? 3 88 m 100 104 108 111 115 18 ill8 19 1121 DlFFEBENCB BETWEEN iNTEBNAL AMD EXTEBNAI, TeMFEBATITBE. 345678910 11 13 13 14 15|16 17 18 19la0 31 33 3334 35 30 26 142 27 1145 28 i]4~ 29 1511 30 153 31 jl55 32 ;158 33 |160 34 1 1(52 35 105 3(i ivn 37 1170 38 172 39 174 40 176 45 187 50 197, 102!ll4 125 107 119 131 111 125 130 116 1.30 140 120,135 147 125 139 153 129 144 158 133 148 lh2 136 153 167 140 157 172 144 161 176 147 165 181 151 169 1-5 154 173 189 158 176 193 161,180 197 164 183 201 167 187 205 170 190 2u7 173 194 212 l';6 197 216 170 20U 21'.( 182 204 22i 185 207 226 188 210 230 190 213 2:a 193 216 2:^6 196 219 240 198 222 243 201 225 246 204 228 249 216 241 264 228 254 279 169 176 1&3 177 185 192 185 193 201 192 201 209 200 209 217 207 216 225 213 223 2;« 220 2;i0 239 226 'iSTi 246 233 243 253 2:^9 249 259 245 255 i 266 250 261 272 256 267 278 261 273 284 267 279 290 272 284 296 277 290 302 282 295 307 287 300 312 292 305 31 Si 297 310 323: 302 315 328: 307 320 333, 311 325 338' 316 330 343 320 334 348 325 339 353 329 344 358 33^ 348 362 338 353 3(i7 358 374 389 377 394 4011 190 200 209 217 225 233 241 248 255 262 269 276 282 289 295 301 307 !313 ,319 324 i330 i335 :341 ,346 ■351 356 1 361 ;,66 371 376 381 404 426 233 239 245 250 255 261 £66 272 276 282 286 292 295 £02 304 311 313 320 321 329 330:338 3381346 3461354 £54 362 361 370 369 378 376 385 383:392 390 > 399 £97^407 404 414 411, '420 4171427 424,434 430 440 4:-:6 447 442 453 448 459 454 465 461 471 467'477 495 506 522,534 244 249 256 261 267 273 278 284 289 295 299 305 319 315 318; 25 327 335 386 344 345 353 354 361 362 370 370 378 378 £86 386 394 394 402 '401 410 408 417 416 425 423 432 430 4;:-9 437 446 443 453 450 460 457 407 463 473 470 AiO 476 486 482 ^92 488 499 518 529 546 558 254 279 267 292 279 305 290 318 301 330 312 341 322 363 332 363 342 374 351 384 360 394 369 404 378 414 366 423 394 432 402 441 410 450 418 458 426 467 433 475 441 483 448 491 455 499 462 £06 469 514 476 522 483 529 490 5: 6 4i 6 543 5C3c51 509 558 540 591 569 C23 I 3 I 4 I 5 I 6 I 7 : 8 I 9 |10 11 13|l3|l4;15| 16il7,18 iy|30 3li33la3|34 35|30 To use the table, determine the heiglit of the warm column of air from the point of entrance to the point of discharge. Ascertain the difference between its temperature and that of the external air. Take out number from table, and multiply by the sec- tion-area of the discharge-tube or opening, in feet or decimals of a foot. The result is the discharge in cubic feet per minute, multipl}' by 60 — result, discharge per hour. Example. — Height of column, 32 feet ; difference of temperature between internal and external air, 17 deg. Looking in the table, we find, opposite to 32 and under 17, 375 feet. That would be for an area of 1 square foot. r 375 ^ .75 But supposing our air opening to be only \ of a foot, we must multiply 375 by \ or 0. 75 of a foot. Therefore we get 281 feet (per minute), multiplied by (jO = 10,860 feet per hour. ' All instruments require correction, as they never give the whole of the velocity. Great care must be taken to ascertain that the correction has been accurately deter- mined, and they should be frequently compared with a standard instrument. EXAMINATION OF AIR AND VENTILATION. 195 Tlie cubic discharge per minute being known, the amount per hour is got by multiplying by 60, and this, divided by the number of men in the room, gives the discharge per head for that particular apertiu-e. An anemometer on a larger scale is fixed in some of the large outlets of the Paris hospitals, showing the movement at every moment by means of an index and dial, ' By the Manometer. — Dr. Sanderson has made an ingenious alteration of a manometer described by Peclet, which can also be employed to meas- ure the pressure, and by calculation the velocity, of the air. The ciUTent of air is allowed to impinge on a surface of water, and the height to which the water is driven up a tube of known inclination and size gives at once a measure of force. But, as necessitating a little calculation, this instru- ment is less useful than the anemometer, though it is adapted for cases where the anemometer cannot be used, as it may be connected by a long tube with a distant room, and probably would be well fitted to measure constantly the velocity in an extraction shaft. In measuring the movement of the air in chimneys, or places w^here either the heat or the dust would injure the air-meter, a manometer must be used. Mr. Fletcher describes what appears to be a good one.^ By Calculation. — Supposing the external air is tranquil, and that the only cause of movement is the unequal weights of the external colder and the internal warmer air, the amount of discharge may be appro ximatel}^ obtained by the law of Montgolfier, already given. There is a fallacy, how- ever, as the amount of friction can never be precisely known. Still, as an approximation, and in the absence of an anemometer, the rule is useful ; and the accompanying table (p. 194) has therefoi'e been calculated. On testing this table, however, by the air-meter, it has been found to give too much when the tubes are long, on account of the great friction, and it is therefore advisable to make a further deduction of |-th when the shaft or tube is long, and is at the same time of small diameter. If the tube has any angles, or is curved, this table is too imperfect to be used, unless attention be paid to the correction for friction already noted. If the movement of the external air influences the movement in the room, as when the wind blows through openings, calculation is useless, and the anemometer only can be depended on. ^SECTION m. EXAMINATION OF THE AIR. 1. BY THE SENSES. Many impurities are quite imperceptible to smell, but it so happens that animal organic matters, whether arising in respiration or in disease, have, for the most part, a peculiar fetid smell, which is very perceptible to those trained to observe it when they enter a room from the open air. This is, in fact, a most dehcate, as well as a ready way of detecting such fetid impurities, and, with a httle trouble, the sense of smell may be cul- tivated to the point of extreme acuteness. Only, it must be remembered, that in a short time the impression is lost, and is not at once regained even in the open air. For a detailed consideration of this question, see Dr. de ' Peclet, De la Chaleur, t. i., p. 171, where the description will be found. ^ Fifth Annual Report of the Inspector under the Alkali Act, Blue Book. 196 PRACTICAL HYGIENE. Chaumont'a papers in the Proceedings of the Royal Society, 1875 and 1876. Among other points, it is shown that the humidity of the air has a very marked influence in rendering the smell of organic matter perceptible, even moi*e powerful than a rise in temperature. Thus the effect of an in- crease of one per cent, in the humidity is as great as a rise of 4.18^ Fahr. in temperatui-e, calculated from the mean of 458 fully recorded observations. ' As the evidence of the senses, however practically useful, is always liable to be challenged, a more thorough examination of the air must in many cases be made. 2. MICROSCOPICAL AND CHEIVnCAL EXAMINATION. The points which should be examined are — * 1. The existence and character of suspended matters as judged of by the microscope, both by immediate observation and after cultiva- tion in prepared nutrient fluids.^ 2. The amount of CO^, which is taken as a convenient measure of all impuiities. 3. The amount of the free or sahne ammonia. 4. The ammonia formed by the action of alkaline pennanganate on nitrogenous substances floating in the air (albuminoid ammonia).* 5. The amount of oxidizable substances, as judged of by the amount of oxygen given off by a standai'd solution of potassium perman- ganate.^ 6. Amount of nitrous and nitric acids. 7. The amoimt of watery vapor. 8. The presence of H„S, or other offensive gases and vapors. 9. The presence or absence of ozone. Microscopical Examination. 1. Suspended Matters. " — It is probable that the microscopical examina- tion of air will give us in future more important information even than the chemical examination. It is, of conrse, a merely qualitative test, as there are no means of jiroperly estimating the amount collected. The suspended matters may be collected very simply by Pouchet's aeroscope. A small funnel is drawn into a small point, below which is a slip of glass moistened with glycerine. The end of the funnel and a slip of glass are inclosed in an air-tight chamber, from which a small glass tube passes out and is connected by india-rubber tubing with an aspirator. As the water runs out through the aspirator, air passes down the funnel and impinges on the glycerine, which an-ests any solid particles. As it is, however, desirable to avoid glycerine, which may (in spite of previous careful examination) contain foreign particles, a still better plan ' Supplementary Note on the Theory of Ventilatipn, Proceedings of the Royal So- ciety, ]^ovember 17, 1876. ■^ The amounts of oxygen and nitrogen can also be determined ; but very numerous observations have shown that the oxygen often varies within extremely narrow limits, even when there is no doubt of the presence of considerable impurity in the air, so that as far as present knowledge gives, the determination of its amount is no good guide as a general rule. ^ On this question, see Tyndall on Floating Bodies in the Atmosphere ; Miquel, Annuaire de Montsouris, 1882 ; and Fodor, Die Luft, op. cit. * For these two processes the determination of the organic nitrogen and carbon, by Frankland's method, may be substituted, if practicable. * See page 1U3 for an account of the suspended matters in air. EXAMHSTATION OF AIR ATH) VENTILATION. 197 is, to take a small bent tube, wash it tlioroughlv, diy it, and heat it to redness ; when cool, it should be placed in a freezing mixture, an india- rubber tube be fixed on one end, and air slowly drawn through ; the water of the ail* condenses in the tube, and many of the solid particles fall -oith it. A drop is then taken by a perfectly clean glass rod, iDreviously heated to redness, placed on a clean glass, and looked at mth an immersion lens, as soon after collection as possible. Or air may be di'awn through piu-e distilled water, a di-op of which is then examined. The late Dr. Watson (Staff- Surge on), in his examination of the au' at Netley,' used fine glass thi-eads soaked in pui-e glycerine, or dry, and crushed glass ; after the au' was drawn through, he washed the glass threads with pure water, and then examined the water. These glass threads form good traps for the larger particles.'^ For thorough investigation, however, it is necessary to caiTy out cultivation experiments, by can-^ing the au- through a sterilized solution, and watching carefully the develop- ment of the different organisms. Fodor recommends a solution of isin- glass, 1^ to 2 j)arts in 300 to 400 of pure distilled water, thoroughly boiled, and decanted or filtered. IMiquel has employed a variety of media, some proving more convenient than others for different purposes. An aspirator, to draw au- through the tubes, is very easily made ; a square tin vessel, with a tap below, and a small opening above to receive the india-rubber tube, is all that is necessary ; fill this with water, and let it run down, and measure the total quantity (in a pint vessel) dis- charged without tilting the vessel. An imperial pint contains 34.659 cubic inches, and one fluid ounce 1.733 cubic inch. A cubic foot is very nearly 1,000 fluid ounces, and the ounce may be taken as 1.728 cubic inch.^ The exact delivery of the aspu-ator is, therefore, easily deter- mined ; the air should be di-awn slowly through the bent tube in the freezing mixtiu-e or through the aeroscoj)e, so that no particles can es- cape. The use of a large glass or earthenware vessel is perhaps better, as being less liable to error ; a piece of india-rubber with a clamp or ^^inch cock, and a double-tubed india-rubber cap, are ah. that are recj^uii'ed. Chemical Examiimtion. 2. Estimation of Carbon Dioxide. — For our pui-pose the method pro- posed by Pettenkofer is the best. A glass vessel is taken capable of hold- ing a gallon, or 4^ htres. The capacity is determined by filhng it with water, and by measuring the contents by means of a litre or pint measure . (1 oz. =28.4 cubic centimetres). Angus S nith recommends extracting the ah' from the bottle by means of bellows. But the most convenient way is simply to fill tlie vessel with water in the place, the air of which is to be examined, and then to let it di'ain for a little. When this is done 60 CO. of clear lime or baiyta water are put in, and the mouth is closed with an india-rubber cap.^ The vessel is agitated so that the lime-water ' Army Medical Department Report, vol. xi. , p. 529. ^ I have found carrying the air through a succession of hottles containing pure dis- tilled water the best plan, for the sediment is examined by the microscope, and the liquid part can be used for chemical examinations for organic matter. — (F. de C.) ^ These numbers are exact at 39' Fahr., or the maximum density point of water. ■* Should an india-rubber cap not be available, a cork or a bung may be used, tied over with leather or oil-skin ; in that case the second alkalinity of the lime-water (if this be used) should be determined as soon after the six or eight hours as possible, certainly within twenty-four hours. 198 PRACTICAL HYGIENE. may run over the sides, and then it is left to stand for not less than six or eight hours if lime water be used ; if baryta water be used, the experiment may be completed in a much shorter time, less than one hova: The CO, is absorbed by the- lime or bar>-ta water, and consequently the causticity of these fluids is, j^ro tanto, lessened. If the causticity of the lime or ba- ryta is known before and after it has been placed in the vessel, the difference wiU give the amount of hme or barj-ta which has become united with C0„. The causticity of lime is determined by means of a solution of crystal- lized oxalic acid,' 1 C.C. of wliich exactly neutralizes 1 milhgi-amme (.001 gramme) of lime ; 30 C.C. o_ lime-water are taken, and exactly neutralized ; good tunneric paper is the best plan that is usually available for determin- ing the exact point of neutralization, and the mai-gin of the drop gives the most dehcate indication. EosoUc acid has, however, been recommended, and also the solution of phenolphthaleine ; the latter gives very exact indi- cations. The amount of lime in the 30 C.C. is then equal to the number of C.C. of oxalic acid used; it is always somewhere between 34 and 41 milligrammes.^ After the lime has absorbed the CO, of the air in the vessel, 30 C. C. of the solution are taken out and tested "uith the oxalic acid solution as be- fore ; the diflference shows the milligrammes of lime precipitated by the CO,. Muhiply the difference by 0.795, the result is the C.C. of CO, in the quantity of au- examined. Deduct 60 C.C. from the total capacity of the jar (to account for the space occupied by the hme-water put in), and state the capacity in litres and decimals ; divide the C.C. of C0„ obtained by the coiTected capacity of the jar ; the quotient is the C.C. of CO, per 1,000 volumes of air. Example. — The first alkalinity of lime-water ) qq r SO C C was .... [ After exposure to the air in the ] qq h ]ar it was ) Difference, being milligrammes ) 6. precipitated by CO, of hme f in jar. Multiply by factor 0.795 4770 = Total CO, in jar in C.C. Capacity of jar 4,385 C.C. Deduct 60 C.C. for space taken up by lime- water 60 Net capacity =4,325 C.C. = 4.325 litrea Then 4.770V 4.325 = 1.103 C.C. of CO, per htre, or volumes per 1,000. The factor 0.795 is obtained as follows: — The difference between the two alkalinities expresses milhgi-ammes of lime i:)recipitated by C0„ ; from this the milligrammes of CO, can be got, by caleiilating from the ratios of the equivalents, thus : CaO. COj. Mgm. CaO. Mgm. of CO3. 56 : 44 \\ a : x : .• . x = a x ■^. As 1 C.C. of CO, at 32° Fahr. (0° Cent.) weighs 1.9767 miUigrammes, ' See Appendis A, Vol. II. ' The amoun:; varies with the temperature, lime being less soluble in hot than cold water ; at 60.7" the amount is 38.6; with a difference of +0.1 for every degree below that, and —0.1 for every degree above (Fahr.). EXAMINATION OF AIR AND VENTILATION. 199 the ratio between weight and volume is -. nnaj = 0.506 ; . • . x x 0.506 = C.C. of COj, coiTesponding to the milligrammes by weight. As 60 C.C. of lime-water were put into the jar, and only 30 C.C. taken, the result must 44 be multipHed by 2. Therefore the factors combined are : ^ x 0.506 x 2 = 0.795, and this, multiphed by a, the difference between the two all^ahnities, gives X, the total C.C. of CO., in the jar. If baryta be used instead of lime, it must be free from traces of potash and soda ; a much smaller quantity of liquid may be employed, as it is so much more soluble than Hme ; the calculation is the same. A correction for the temperature of the air examined must be made, the standard being 32° Fahr., or 0° C, the freezing-point of water. If the temperature be above this (as it will generally be, at least in buildings) the air will be expanded, and a smaller quantity, by weight, consequently, will be operated on. On the other hand, below 32° the air will be con- tracted, and a larger quantity, by weight, operated on than at the standard tempei'ature. This can be corrected by adding 0.2 per cent, to the result* for every degree above 32^^, and subtracting it for every degree below ; the reason being that air expands or contracts 0.2 per cent, for every degree (or 1 per cent, for every 5 degrees) it deviates from' the standard. Example. — In the preceding example the CO^ was found to be 1.103 per 1,000. Suppose the temperature to have been 60° Fahr., then 60-32 = 28° to be corrected for ; 28 x 0.2 = 5.6 per cent, to be added on to result, or the result must be multiplied by 1 + . 056 = 1.056, .-. 1.103 x 1.056 = 1 154 per 1,000, the corrected result. Suppose the temperature had been 25°Fahr., then 32-25 = 7° to be corrected f or ; 7 X 0.2 = 1.4 per cent, to be deducted, or the resultmustbe multiplied by 1.00-. 014=0.986, .-. 1.103 X 0.986=1.087, the corrected result. A correction for pressure is not necessary, unless the place of obser- vation be much removed from sea-level ; in that case, the barometer must be observed, and a rule of three stated. As standard height of bar : ) j observed height } (=29.92 in. =760 mm.) : j ] of bar: y- ■ a : x. It must be understood that none of the methods hitherto used for the determination of CO, in the air give quite accurate results, but the above is the most convenient for ordinary use and is sufficiently accurate for practical purposes. The results differ considerably if the quantities of air treated vary, therefore uniformity in this point is desirable. Dr. W. Hesse (of Schwarzenberg) has devised an ingenious portable apparatus for determination of C0„, l3ut the quantities of air treated seem rather too small. The apjDaratus includes the various apparatus necessary for measuring cubic space, determining air currents, ascertaining the CO^, and observing the humidity (by Wolpert's hygrometer). 3 and 4. Estimation of Free Ammonia and of the Nitrogenous Matter in Air by Conversion into Albuminoid Ammonia. — The nitrogenous matter ex- isting in air may be in the form of dead or living matter of very various kinds. Its determination may be useful as showing that one or other of these classes of substances exists in the air in proportions greater than in pure air. The amount of nitrogen may be estimated in a similar man- ner to that proposed by Wanklyn and Chapman for water. The late Mr. Chapman,' finding that water did not sufficiently absoi'b the nitrogenous 1 Chemical News, February 11, 1870. 200 PEACTICAL HYGIENE. substances in air, proposed to heat finely powdered pumice-stone to red- ness, to moisten it with pure water, and then to place it over some coarse pieces of pumice-stone supported on wire in a funnel ; a definite quantity of air (say 100 litres) is then drawn through the funnel ; the pumice-stone is transferred to a retort containing water freed fi'om ammonia, and dis- tilled as in the determination of the albuminoid ammonia of water. Dr, Angus Smith ' takes a bottle of about 2,000 C.C. capacity, places in it SO- SO C.C. of the purest water, draws into it the air to be examined, and then agitates the water in the bottle, and proceeds as in Wanklyn's and Chap- man's water test. The most convenient way is to draw the air by means of a measured aspirator, through a succession of wash bottles, each con- taining 100 C.C. of water, perfectly free from ammonia, and then to de- termine the free and albuminoid Nllg by Wanklyn's method. Another plan is to lead a definite quantity of air through a clean curved tube, suri'ouuded by a freezing mixture ; the water of the air condenses, and with it much of the organic matter ; the tube is then washed out with pure water, the washings are put into a retort with ammonia-free water, ,and distilled as usual. After passing through the tube the air should be led through piire water to arrest the portion of organic matter that always escapes condensation. The amount of ammonia (free and albuminoid) is determined as in water analysis. The mere presence of free ammonia may be determined by exposing strips of filtering paper, dipped in Nessler's solution or in ether- ial solution of the alcoholic extract of logwood ; the former becomes yel- low, the latter jDurple. The quantity of air drawn through must, of course, be accurately de- termined by a properly arranged aspirator, and the results then calculated in milligrammes j)er cubic metre, ^ 5. Estimation of the Oxidizable Matters in the Air in terms of Oxygen. — In this case a definite quantity of air is drawn through a solution of per- manganate of potassium of known strength, and the amount of undecom- posed permanganate is determined by oxalic acid. Or part of the water through which the air has been draAvn for the ammonia determinations may be examined in the same way as in the case of drinking water. The permanganate acts upon various matters in the air, besides the putrescible organic matters, such as hydrogen sulphide, nitrous acid, tarry matters, etc. The presence or absence of H„S may be determined qualitatively by means of acetate of lead papers, ammonium sulj^hide by pajoer dipped in niti'oprusside of sodium ; whilst tarry matters would generally be re- cognized by the smell of the water, or its turbidity. In the absence of these the difference between the permanganate determinations, before and after boiling with sulphuric acid, may be calculated as nitrov;s acid, as in the case of drinking water ; whilst the result after boiling may be reckoned as the oxygen for oxidizable organic matter only.^ 6. The Nitrous and Nitric Acids may also be determined, in the same way as in drinking water, from the w^ashings of the air obtained as above. All these determinations should be made, when opportunities ofier, as the results may prove hereafter of some value. 7. Watery Vapor. — The hygi'ometric condition of the air is ascertained in various ways, especially by the dry and wet bulb thermometer, or by ' Air and Rain, p. 421. 2 One cubic metre equals 1,000 litres, or 1,000.000 C.C. 2 See Reports on St. Mary's Hospital, by Dr. F. de Chaumont. EXAMINATION^ OF AIR AND VENTILATION. 201 Dines' direct hygrometer. The hau' hygrometer of Saussure is also a use- ful instrument for this joui-pose, as it marks the degree of humidity yeiy quickly. Wolpert's horse-haii' hygrometer may also be used. 8. The presence of H.-,S, etc., has been referred to above. SECTION TV. SCHEME FOR THE APPLICATION OF THE FOREGOING RULES. When a ventilation inquiiy is about to be made, everything ought to be got ready beforehand. A number of bottles (about 4 to 4^ litres), or glass jars, ought to be carefully measured, and the capacity in C.C. (less 60 C.C. to account for the lime-water) marked upon them ; each- bottle ought also to have a closely fitting india-rubber cap and a distinctive number. These bottles are to be used for collecting the samples of air for Co,. Charges of lime-water (or baryta-water) (each 60 C.C.) ought to be carefully measured off with a burette, or graduated pipette, into small stoppered bottles. Two or more sets of wet and dry bulb thermometers' ought to be ready, and two or more series of not less than six bottles, each containing about 100 C.C. of pure distilled water, connected together vfith glass tubes and india-rubber caj^s ; also four or more asph-ators foi drawing the aii- through the bottles. One of CaseUa's small air-meters, with a long pole in joints, intu which it can be screwed, a measui'ing ta23e and foot-rule, a pocket-compass, some pieces of cotton-velvet, a note-book, are also necessary. When a room has to be examined, enter it after being some time in the open air, and notice if there be any smell ; record the sensation at once in your notes. Hang up the wet and diy biilb thermometer (if it has not been placed there before), and then proceed to take samples of the aii" for C0„ ; fin the jars with water, empty them, and allow them to di-ain ; then pour into each jai' the hme-water fi'om one of the small bottles, put on the india-rubber cap, and shake it up. Always take tico samples at least, and more if a large room. Xote the numbers of the bottles. Take the wet and dry bulb readings. Ai-range the set of bottles with distilled water in some convenient place, and attach them to one of the aspirators, which may be allowed to flow into another below it. When the upper one is empt}' it may be changed for the lower one, and so the stream of air may be carried on for any length of time, as seems necessary, — the number of times the aspirators are changed should be duly noted. In determiniug the carbon dioxide, put out all the lights, or have only sufficient for work- ing ptu'poses ; allow no smoking, and have no person in the room but those who are sleeping there. The aspu-ators may be allowed to go on continuously, but the examination of the air for CO., ought to be repeated at intervals, the exact time of observations being noted. At the same time, similar observations ought to be made in the open au-, as nearly as possible simultaneously with those inside. At some convenient time the measure- ments of the room and the ventilators, the velocities of the currents of air, etc., should be taken on some such plan as the following : — Measiu'e the cubic space, then consider the jDossible sources of entrance and exit of air ; if there are only doors and windows, notice the distance between them, how they open, on what external place they open ; whether there is free passage of air from side to side ; whether it is hkely the air ■v\-ill be properly distributed. On all these points an opinion is soon ai-iived at. 202 PRACTICAL HYGIENE. If there are other openings, measure them all carefully, so as to get their supei'ficies ; the chimney must be measured at its throat or smallest part. Determine then the du-ection of movement of air through these openings by smoke, noting the apparent rapidity. The doors and windows should be closed. When the inlets have been discovered, consider whether the air is drawn from a jDiu-e external source, and whether there is proj^er dis- tribution in the room. Then measure the amount of movement in both inlets and outlets with the anemometer, or calculate by the table if it seems safe to do so. If the ventilation of the room is influenced by the wind, the horizontal movement of the external air should be determined by Robinson's anemo- meter, or the little air-meter by Casella may be also used for this purpose, unless the wind be very strong. In recording the velocity of the air at any openings it is convenient to mark an incoming cuxTcnt with apZws sign and an outgoing with a minus, thus : + 75 would mean an incoming current at the rate of 75 feet per minute ; while — 63 would mean an outgoing current at 63 feet per minute. When the final analyses are made, and the amoimt of CO^ determined, the amount of air per head per hour, supplied and utilized, ought to be calculated out (as before explained), and compared with the amount of movement determined with the aii'-meter. If the quantities accord fairly, the distribution may be considered good ; on the other hand, if they differ, an excess by the air-meter shows bad distribution, w^iilst a deficiency indi- cates some other source of incoming air noi. yet observed. The water, through which the air has been passed by the aspirator, ought to be examined at once, if practicable ; if not, the bottles ought to be carefully stoppered, and the stoppers tied down \\dth leather or strong linen, — when convenient, the sediment should be examined microscopically, and the water (when the sediment has subsided) chemically ws before explained. The sediment or a portion of the water should be put into a cultivating solution for further investigation, if opportunity affords. CHAPTER V. FOOD. SECTION I. GENERAL PRINCIPLES OF DIET. Is the widest acceptation of the term, Food includes every thing ingested, which goes directly or indirectly to the growth or repair of the body, or to the production of energy in any form. In this way it would include not only those organic and mineral solids and the usual beverages recognized as dietetic, but also water and aii'. For it is Cjuite obvious that without water no function of the living body would be possible, whilst the produc- tion of energy is mainly, if not entu-ely, caused by the union of the atmos- pheric oxygen with the organic matter of the food or the tissues of the body itself. Although these facts are distinctly recognized, it has generally been the practice to restrict the term "food" to those substances which are capable of oxidation, or those which act as directors cr regulators of nutrition, to the exclusion of air and water ; these two last being usually considered under separate heads. No one group even of this rough classi- fication is capable of sustaining healthy life alone, and a combination of aU, or nearly all, the different constituents of diet is required to accom- plish the best results. It is also necessary to hmit the appellation, "food," so as to exclude generally medicines and poisons, which, on the one hand, either act, or are intended to act, upon processes of unhealthy nutiition, or, on the other hand, prevent the processes of healthy nutrition, and so induce unhealthy nutrition, and ultimately dissolution. Even here the line can- not be too strictly drawn, for in many cases it is a question more of quan- tity than kind that determines the dii-ection of the action. The enumeration and classification of the foods or aliments necessaiy to maintain human life in its most perfect state have been usually based on the deduction of Prout, that milk contains all the necessaiy ahments, and in the best form. The substances in milk are — 1st, the nitrogenous mat- ters, viz., the casein princijDally, and in smaller quantities, albumin, lacto- protein, and perhaps other albuminous bodies ; 2d, the fat and oil ; 3d, sugar in the form of lactin ; 4th, water and salts, the latter being espe- cially combinations of magnesium, calcium, potassium, sodium, and iron, vdth chlorine, phosphoric acid, and in smaller quantities sulj)huric acid. In addition to their occun'ence in milk, which is admitted to be a i^er- fect food for the young, this enumeration of ahments appears to be justi- fied by two considerations. First, that the different members of each class, inter se, have a remarkably similar composition, while there are broad lines of physical and chemical demarcation between the classes ; and secondly, that the different classes appear to serve different pui-poses in nutrition, and are all necessaiy for perfect health. The first point, the similarity of composition among the different mem- 204 " PRACTICAL HYGIENE. bers of the same class, is obvious enough. The nitrogenous ahments are blood-fibrin, muscle fibrin or syntonin, myosin, vegetable fibrin, albumin in its various forms, casein (in its animal and vegetable forms), and globu- lin. Their conjposition, etc., are remarkably uniform ; they contain be- tween 15.4 and 1G.5 per cent, of nitrogen, and may be conveniently distin- guished by the common term of albuminates. They can replace each other in nutrition. There are some other nitrogenous bodies, such as gelatin and chondrin, and the substances classed under keratin or elastin, which, though approaching in chemical characters to the other substances, ai-e not their nutritive equals. The second class consists of the various animal and vegetable fats, wax, etc., the composition of which is very uniform, and the chief nutritive differences of which depend on physical conditions of form or aggregation, which conditions cause some fats, when acted upon by the aHmentary fluids, to be moi-e easily absorbed than others. The group of the starchy and saccharine substances (the carbo-hydrates), or of their alhes or derivatives (dextrin, pectin), is equally well character- ized by chemical resemblances, inter se, and differences from the other groups. The several dietetic starches, sugars, including lactin, cellulose (whose want of nutritive power is dejoendeut on form and aggregation, and which requires for digestion a more elaborate apparatus than some animals possess), and the various derivatives of the starches, are all closely aUied. There has been some doubt whether pectin sliould be classed chemically vrith the sugar and starch group, as the oxygen and hydrogen are not in the proportions to form water, but this is perhaps no objection to its asso- ciation in a dietetic classification. The foui-th class, consisting of the salts already noted and of water, needs no comment. The physiological evidence that these classes of ahments serve different purposes in nutrition is not so complete as that of their chemical diff"er- ences. A broad distinction must, of course, be drawn between the nitrogenous and non-nitrogenous substances. Late researches, w^hich have much modi- fied our opinion of the direction in which the potential energy of the diet- etic princijiles may be manifested (as heat, or electricity, or mechanical movement), and of the mode in which the nitrogenoiis substances in par- ticular, aid or restrain this transformation, do not impeach the proposition that the presence of nitrogen in an organized structure, and its participa- tion in the action going on there, is a necessary condition for the manifes- tation of any energy, or any chemical change. Whether, when energy is manifested, the nitrogenous framework of any nitrogenous structure is a mere stage on which other actors play, or whether it in used up and destroyed, or is, on the other hand, built up or renovated during action, is, so far as classification of food is concerned, a matter of no consequence. The following considerations seem to prove the necessary participation of the nitrogenous structures in manifestations of energy. Every structiire in the body in which any form of energy is manifested (heat, mechanical motion, chemical or electrical action, etc.) is nitrogenous. The nerves, the muscles, the gland-cells, the floating cells in the various liquids, the semen and the ovarian cells, are all nitrogenous. Even the non-celhilar Uquids passing out into the alimentary canal at various points, which have so gTcat an action in preparing the food in different ways, are not only nitrogenous, but the constancy of this implies the necessity of the nitrogen, in order that these actions shall be performed ; and the same constancy of the presence FOOD. 205 of nitrogen, when function is performed, is apparently traceable through the whole world. Surely such constancy proves necessity. Then, if the nitrogen be cut off from the body, the various functions languish. This does not occur at once, for every bod}' contains a store of nitrogen, but it is at length inevitable. Again, if it is wished to increase the manifestation of the energies of the various organs, more nitrogen must be supj^lied. The experiments of Pettenkofer and Voit show that the nitrogenous sub- stances composing the textures of the body determine the absoi-ption of oxygen.' The condensation of the oxygen from the atmosphere, its con- version into its active condition (ozone), and its application to oxidation, are according to their experiments entirely under the control of the nitro- genous tissues (fixe'd and floating), and are apparently proportional to their size and vigor, ^ and to changes occurring in them. The absorption of oxygen does not determine the changes in the tissues, but the changes in the tissues determine the absorption of oxygen. In other words, without the participation of the nitrogenous bodies, no oxidation and no manifesta- tion of energy is possible. The experiments show that the absorption of oxygen by the lungs (blood-composition, and physical conditions of pres- sure, etc., remaining constant) is dependent on its disposal in the body, and that this disposal is in direct relation with the absolute and relative amount and action of the nitrogenous structures. Mechanical motion, electricity, or heat may be owing to oxidation of fat or of starch, or of nitrogenous substance ; but whatever be the final source, the direction is given by the nitrogenous structures. The next point is not quite so clear. Are the non-nitrogenous bodies, the fats and the starches, to be again broadly separated into two groups, which cannot replace each other ; or, are these nutritively convertible ? It is now certain that fat may arise from albuminates, so that the nitrogenous substance plays two parts — first, that of the organic framework, i.e., of tlie regulator of oxidation and of transformation of energy; and, second, it may form a non-nitrogenous substance which is oxidized and transformed. The experiments of Edward Smith, Fick and Wislicenus, Haughton, and others, on muscular action, prove that we must look for the main source of energy which is apparent during muscular action in the oxidation of non-nitrogenous substances, but no experiments have yet shown whether these are fatty or saccharine. It seems to be inferred that it is fat which is thus chiefly acted upon ; but this opinion is rather derived from a refer- ence to the universal presence of fat when energy is manifested, to the known necessity of it in diet (for though the dog and the rat (Savory) can live on fat-free meat alone, man cannot do so),^ and from the large amount of energy its oxidation can produce, than from actual observation. If it were true, a broad distinction would be at once drawn between fatty and starchy food, but it is not experimentally proved. If, on the other hand, it were certain that the starchy aliments formed fat in the human body as a rule, this would be a reason for drawing no distinction between the groups. Independent of the argument drawn from bees fed on sugar alone and forming wax, from the fattening of ducks and geese, and the older experi- ^ Zeitsch. fiir Biologie, Band ii., p. 457. See especially, tlie summary of their opinion at page 571. ^ When to a diet of meat, which causes a certain absorption of oxygen, fat or sugar is added, the absorption of oxygen lessens (Ranke, Phys. des Menschen, 1868, p. 145) ; 80 that it is relative as well as absolute amount which comes into play. ^ Ranke could not maintain himself in perfect nutrition on meat alone. — Physiol, des Menschen, 1868, p. 149. 206 PRACTICAL HYGIENE. ments on pigs, the later experiments of Lawes and Gilbert ' seem to show clearly that the fat stored up in fattened pigs cannot be derived from the fat given in the food, but must have been produced partly from nitrogenous substances, but chiefly from the carbo-hydrates. So also it seems now probable that the fat in milk is not derived at once from blood, but fi-om changes of albumin in the lacteal gland-cells. There seems no reason why we should not extend the inference to man. If so, a man could live in perfect health on a diet composed only of fat-free meat and starch, with salts and water, just as he can certainly live (though perhaj^s not in the highest health) on meat, fat, salts, and water. The carbo-hydrates would then be proved to be able to replace fats. The experiment has not yet been performed or at least recorded, but it seems important it should be. Grouven's exjDeriments also suggest that in cattle the carbo-hydrates may split up in the alimentary canal into glycerine, lactic and butyric acids, and cai'bon dioxide and marsh gas. If this be true, in the herbivora the starches would be merely another form of fat. An argument against the fats and carbo-hydi-ates being mutually re- placeable under ordinary conditions in the diet of men is drawn from a consideration of the diets used by all nations. In no case in which it can be obtained is an admixture of starch, in some form, with fat omitted. Moreover, in all cases (except in those nations, like the Eskimos, who are under particular conditions of food), we find that the amount of fat taken is comparatively small as compared with that of starches. The fats when taken into the iDody enter hke the albuminates into the structure of the tissues," of which fat forms in probably all cases an essential part. The carbo-hydrates, on the other hand, in the human body do not appear to be parts of the tissues, though they are contained in the fluids which bathe them, or are contained in them. The sj)ecial direction which the chemical changes in the carbo-hydrates take in the body, seem also to point to special duties. Thus, the formation of lactic and other acids of the same class must arise from carbo-hydrates chiefly or solely. But the formation of these acids is certainly most important in nutrition, for the various reactions of the fluids, which ofi"er so striking a contrast (the alkalinity of the blood, tbe acidity of most mucous secretions, of the sweat, mine, etc.), must be chiefly owing to the action of lactic acid on the phosphates, or the chlorides, and to the ease with which it is oxidized and removed. If the direction of the changes which the carbo-hydrates undergo within the body is different from that of the fats, the products of these changes must be inferred to play dissimilar parts. "Without jDushing these ai'guments too far, and with the admission that the subject is still obscure, we are fairly entitled to assert that the two groups of fats and carbo-hydrates are not so immediately and completely convertible as to permit us to place them together in a classification of diets. In the second question to which reference was made, "viz., that of a nitrogenous substance fiu'nishiiig fat, or a carbo-hydrate, the case is simpler. The experiments of Voit, and of Lawes and Gilbert as well as other con- siderations, prove that the fat of tissues may be derived from nitrogenous ' On the Sources of the Fat in the Animal Body, Phil. Mag , December, 1866. "^ The fats appear to pass into the body directly and alter saponification, which ren- ders absorption easy. The soap is then, according to Radziejevvski's experiments (Vir- chow's Archiv, Band xliii. , p. 26b), reconverted into fat. It has been supposed that the greater part of the tissue fat (fat cells) is not derived in this way, but from the tissue albuminates; but Hofmann's experiments and reasonings (Zeitsch. fiir Biol., Band viii., p. 153) seem to show that the ingested fats are stored up largely. Clinical observa- tions certainly support this view. FOOD. 207 substances, and there are reasons to believe that a glycogenous substance may also be derived from albuminates.' It is also probable, though not proved, that these non-nitrogenous derivatives may be burnt up in the muscles and other parts, as Fick conjectures.^ But this cannot allow us to consider an albuminate as an aliment which may replace fat or starch in the case of man. The digestive system of man is framed so differently from that of the carnivora, that fat must be taken in its own form, for it either cannot be formed in sufficient quantity from albuminates, or the body is poisoned by the excess of nitrogen which is necessarily absorbed to supply it. With regard to the necessity of all four classes of aliments, it can be affirmed with certainty that (putting scurvy out of the question) men can live for some time and can be healthy with a diet of albuminates, fat, salts, and water. But special conditions of life, such as great exercise, or ex- posure to very low temperature, appear to be necessary, and under usual conditions of life, health is not very perfectly maintained on such diet. It has not yet been shown that men can hve in good health on albuminates, carbo-hydrates, salts, and water, etc., without fat.^ The exact effect produced by the deprivation of any one of these classes is not yet known. An excess of the albuminates causes a more rapid oxi- dation of fat (and in dogs an ehmination of water), while an excess of fat lessens the absorption of oxygen, and hinders the metamorphosis of both fat and albuminate tissues. The carbo-hydrates have the same effect when in excess, and appear to lessen the oxidation of the two other classes. It is now generally admitted that the success of Mr. Banting's treat- ment of obesity is owing to two actions : the increased oxidizing effect on fat, consequent on the increase of meat (especially if exercise be combined), and the lessened interference with the oxidation of fat consequent on the dejDrivation of the starches. Health cannot be maintained on albuminates, salts, and water alone ; but, on the other hand, it cannot be maintained without them. The salts and water are as essential as the nitrogenous substances. Lime, chiefly in the form of phosphate, is absent from no tissue ; and there is reason to think no cell growth can go on without it ; certainly, in enlarging morbid growths and in rapidly growing cells, it is in large amount. When phosphate of calcium was excluded from the diet, the bones of an adult goat were not found by H. Weiske to be poorer in lime,* because probably lime was drawn from other parts ; but the goat became weak and dull, so that nutrition was interfered with. Experiment has shown that the growth of wheat is more quickly and effectually checked by the ab- sence of phosphoric acid than of any other constituent fi'om the soil. The lowest forms of life {Bactey^ia and Fungi) will not grow without earthy phosphates. Magnesia is probably also an essential constituent of growth in some tissues. Potash and soda, in the forms of phosphates and chlorides, are ' In addition to physiological evidence from experiments on animals, there are cer- tain forms of diabetes which seem to prove that sugar must be formed either from albuminates or fat, most probably the former. ■^ Archiv. fur ges. Phys., Band v., p. 40. ^ In some experiments, both with Liebig's essence of meat and Hassall's dried food with bread, Dr. Parkes was very much struck with the bad effect produced on the health of the experimentators, and with Ihe immediate relief given by the addition of butter and a larger supply of starch, without augmentation in the amount of nitrogen. * Zeits. fur Biol., Band vii., p. 179 208 PRACTICAL HYGIENE. equally important, and wovild seem to be especially concerned in the mo- lecvdar currents ; forming parts of almost all tissues, they are less fixed, so to sjDeak, than the magnesian and lime salts. It is also now certain, that the two alkalies do not rejilace each other, and have a different distribu- tion ; and it is so fai' observable, that the jDotash seems to be the alkali for the formed tissues, such as the blood-cells or muscular fibre ; Avhile the soda salts are more largely contained in the intercellular fluids which bathe or encircle the tissues. The chloi-ine and phosphoric acid have also very pecuHar propertie.s — the former apparently being easily set free, and then giving a very strong acid, which has a special action on albuminates, and the latter having re- markable combining proporiions with alkahes. Both are fiu-nished in almost all food ; the sodium chloride also sepai'ately. Carbonic acid is both introduced and made in the system, and probably serves many uses. Iron is, of course, also essential for certain tissues or parts, esjDecially for the red-blood corjxiscles, and for the coloring matter in muscle, and in small quantity is found almost in eveiy tissue, and in eveiy food. The sul- phur and phosphoms of the tissues apj)ear to enter especially as such with the albuminates. Some salts, especially those which form carbonates in the system, such as the lactates, tartrates, citrates, and acetates, give the alkalinity to the system which seems so necessary to the integrity of the molecular cur- rents. The state of malnuti-ition, which in its highest degree we call scurvy, appears to follow ineritably on their absence ; and as they exist chiefly in fresh vegetables, it is a well-known inile of dietetics to supj^ly these with great care, though their nutritive power othei-wise is small. So important are those substances, that they might well be placed in a sepa- rate class, although Dr. Faxj remarks that " these principles are hardly of sufficient imjDortance, in an ahmentary point of riew, so called, for their consideration under a distinct head." Surely, this is an under-estimate of their importance, considering the inevitable malnutrition that follows on their absence. In addition to the substances composing these four classes, there are others which enter into many diets, and which have been termed " acces- soiT foods," or by some writers "force regulators" (like the salts). The various condiments which give taste to food, or excite salivary or alimentary secretions, and tea, coffee, cocoa, alcohol, etc., furnish the chief substances of this class. Much discussion has taken place as to the exact actioii in nutrition of these substances, but little is definitely known. A classification, on a simplified plan, may be made as follows : to ) 1. Albtimi'nafes. All substances containing nitrogen, of a composition iden- tical with, or nearly that of albumin ; proportion of nitro- gen to carbon being nearly as 2 to 7, or 4 to 14. Examples, f Albumin, I Fibrin, Syntonin, Myosin, *^* Substances containing a larger proportion of nitrogen are apparently less nutritious. Proportion of nitrogen to car- [bon about 2 to U, 4 to 11. < I Globulin, (Casein, i r ^ ! Glutin, §3 1 Legumin, > [ Gelatin, Ossein, Chondrin, Keratin, Functions. Formation and repair of tissues and fluids of the body. Regulation of the ab- sorption and utilization of oxygen. May also form fat and yield energy under special conditions. Tliese perform the above functions less perfectly, or only under particular cir- cumstances. FOOD. 209 f 3. Fats (or Hydro-Carbons). ^ Substances containing no ni- trogen, but made up ot: carbon, bjdrogen, and osj-gen ; the pro- portion of oxjgen being less than sufficient to convert all the hy- j drogen into water. Proportion of unoxidized hy- drogen to carbon about 1 to 7. j 3. Carbo-hydrates. ^ Substances containing no ni- trogen, but made up of carbon, hydrogen, and oxjigen ; the oxy- \ gen being exactly sufficient to j> convert all the hydrogen into water. Proportion of water to carbon being about 3 to 2. J Examples Olein, Stearin, Margarin, Starch, Dextrin, Cane sugar, Grape sugar, Lactin (or milk sugar), Functions. Supply of fatty tissues ; nutrition of nervous sys- tem ■? Supply of energy and animal heat by oxida- tion. Production of energy and animal heat by oxida- tion. Conversion into fat by de-oxidation. 3 («)• Vegetable acids (and pectcus substances P) Substances containing no ni- trogen, but made up of carbon, hydrogen, and oxygen ; the oxy- gen being generally in greater amount than is sufficient to con- vert all the hydrogen into l_^ water. r S -{ 4 Salts (mineral). Oxalic acid, Tartaric " Citric " i- Malic " fin these the^ Preserving the oxygen is mare j than sufficient 1 to convert all I alkalinity of the blood by conver- sion into carbon- I the hydrogen [> ates ; furnish a 1^ into water. 1 small amount of Acetic " ^ In these there energy or animal Lactic " •< is no excess of j heat by oxida- J ( oxygen. J tion. f Sodium chloride, ^ Various : support of I Potassium " | bony skeleton, supply of ■{ Calciiim phosphate, }■ HCl for digestion, etc. I Magnesium " | Regulators of energy and l^Iron, etc. J nutrition. Si's- Section' L — QrA^'Tirr of each Class of PEOxniATE Altmext en- a Good Diet foe Healthy Men. "We cannot deduce these quantities fi'om milk, for this, though it is a perfect food for the young, does not contain the various constituents in the best proportions for adults. The relative amounts have, therefore, been determined partly by observation on a great number of dietaries, and partly by physiological experiments. The general results of the v,-hole are given in the following tables : — Average Daily Diet of Men in Quietude. Sabsistence Diet (Playfair). East. Oanc8s Avoir.' Grammes. 1 Ounces Avoir. Granunes. Albuminates 2.0 0.5 12.0 0.5 57 14 310 14 2.5 1.0 12.0 71 Fats 28 Carbo-hydrates 340 Salts 0.5 14 Total water-free food . . 15.0 425 i 1 16.0 453 The subsidence diet is calculated as sufficient for the internal mechani- cal work of the body, but it is doubtful if an average man could exist on it without losing weight, as it supposes absolute repose. Vol I.-14 210 PRACTICAL HYGIENE. The diet foi' rest supposes very gentle exertion, and is probably the minimum for a male adult of average size and vreight, say 150 ib or 67 kilogi'ammes. Each constituent above named is, theoretically, absolutely water-fi'ee, but practically the amount of "n"ater present in the so-called sohd food would be from 100 to 150 per cent, more, so that the weights respectively would be about 32 to 40 ounces gi-oss (907 to 1,134: grammes). For mere subsistence, without doing visible work, a man therefore re- quii'es about y'„ of an ounce of water-fi'ee food for each ft weight of his body, or about ji-^ of his total weight every twenty-four hours. Of the standard diets given in the next table, Moleschott's scale has been pretty generally accepted, but the fat is iDerhajDS rather low. Assuming the water-fi'ee food to be 23 ounces, and a man's weight to be 150 lb, each ib weight of the body receives in twenty-four hours 0.15 ounces, or the whole body receives nearly yJpg- part of its own weight. This is the dry food, but a certain amount of water (between 50 and 60 per cent, usually) is contained in ordinaiy food, and adding this to the water-fi'ee sohds, the total daily amount of so-called dry food (exclusive of liquids) is about 48 to 60 ovmces. In addition to this, from 50 to 80 Standard Daily Diets for a Man in Ordinary Work. Albuminates Fats Carbo-hydrates Salts Total water-free food. Moleschott. I Pettenkofer and Voit-i 1 1 1 Eanke." 1 Oz. Av. Gram. Oz. Av. Gram. Oz. Av. Gram. 4.59 2.96 14.26 1.06 130 84 4041 30 1 4.83 4.12 12.40 1.06 137 117 352 30 3.52 3.52 8.46 0.89 100 100 'l 240 ' 25 22.87 648 22.41 636 1 16.39 «'ii Means. Oz. Av. Gram. 4.31 3.53 11.71 1.70 123 100 332 28 20.65 582 ounces of water are taken in some liquid form, making a total supply of water of 70 to 90 ounces, or on an average 0.5 ounce for each ft weight of body. This average amount of food and water varies considerably from the following causes : — 1. Individual conditions of size, vigor, activity of circulation, and of the eliminating organs, etc. No men eat exactly the same, and no single standard will meet all cases.' The usual average range in different male ' Zeitschrift fiir Biologie, Band ii., p. 523. Somewhat different quantities are given by Voit in his later researches made with Forster, Renk, and Schuster (Munich, 1877), the fat during work being much increased. See Fliigge, Lehrbuch der hygienischen Untersuchungsmethoden, Leipzig, 1881. - Physiologie des Menschen, 18(j8, p. 1^8. ^ This has been well exemplified in our convict prisons, in which, as a matter of convenience, soldiers are sometimes confined. The ordinary diet, which is suflicient for the convict, is insuflficient for the soldier, and that for several reasons: 1. The convict is a smaller man on the average. 2. The previous life of the convict is an irregular one, in which his food is generally insuflicient ; whereas the soldier's life is usually the opposite, his food is fairly good and his meals regular. 3. The crimes for which the convict is imprisoned are crimes against society, and his removal to a prison cannot be considered much of a degradation morally, whereas his physical condition is really im- proved. On the other hand, the soldier's crime is often one of a military character only, hence his removal to a prison is a moral degradation, especially if it be a convict prison. The result is, that, whilst the majority of the civil prisoners retain their weight or even :FOOD. 211 adults is from 40 to 60 ounces of so-called solid food, and from 50 to 80 ounces of water. 2. Differences of exertion. If men are tmdergoing great exertion they take more food, and, if they can obtain it, the increase is especially in the classes of albuminates and fat, as shown in the next table. This would represent of so-called sohd food from 66 to 77 oz. (1,970 to 2,180 gxammes). The amount of water is also increased, but is veiy various according to circumstances, and is apj^arently not so much augmented as the sohd food. 3. Diff'erences of climate. It is a matter of general behef that more food is taken in cold seasons and in cold countries than in hot. It is sup- posed that more energy in some fonn (finally in that of heat) is necessary, and more food is requned ; but there may be other causes, such as varying exertion. Average Daily Water-free Diet required for an adult Man in very laborious Work,^ or of a Soldier on Service and in the Field. Ounces Avoir. Albuminates Fats Carbo-hjdrates Salts Total water-free food. 6.0 to 7.0 170 to 198 3.5 to 4.5 99 to 128 16. 0' to 18.0 454 to 510 1.2 to 1.5 34 to 43 26.7 to 31.0 757 to 879 The following may be taken as an approximative basis for the calcula- tion of diets according to size and work : — For subsistence during rest. j For work of about 300 foot-tons per diem. For work of about 100,000 kilog.-metres per diem. Proximate Aliment. OuncesAvoir. per lb. of body weight. Grammes per kUogTamme of body weight. OuncesAvoir. per lb. of body weight. Amount to be added to sub- sistence diet per Ib.of body for every foot- ton of work. OuncesAvoir. G-rammes per kilogramme of body weight. Amount to be added to sub- sistence diet per kilogr. of body weight foreveryl.OOO kilog.-metres of work. Grammes. Albuminates . . Fats Carbo-liydrates, Salts .017 .007 .080 .003 1.1 0.4 4.9 0.2 .031 .019 .095 .007 .00005 .00004 .00005 .00001 1.9 0.9 7.3 0.4 .008 .005 .023 .003 Total. . . . .107 6.6 .152 .00015 10.4 .038 gain, tbe majority of soldier prisoners lose. It is also found that age has an effect, the older men losing, tbe younger generally gaining. Length of sentence has also an in- fluence, partly on account of some difference of diet and work, but probably chiefly on account of the svstem ultimatelv accommodating itself to the altered conditions. Thus the men who lose weight are, the heaviest originally, the oldest, those with short- est sentences ; those who are stationary or gain weight are, the lightest originally, the youngest, those with longest sentences. For the data, from which the above conclu- sions'are drawn, I am indebted to Brigade-Surgeon J. G. Marston, M.D. — (F. de C.) ' Plavfair gives the diet of a prize-fighter in training as 9.8 ozs. albiiminates, 3.1 fats, and 3.27 starch and su^ar. There w'ere 690 grains of nitrogen, and 4,366 grains of carbon. 212 PKACTICAL HYGIENE. Beyond 300 foot-tons (or 100,000 kilogramme-metres) the addition would require to be greater. For work of 450 to 500 foot-tons per diem. For work of about 150,000 kilogramme- metres per diem. Proximate Aliment. Ounces Avoir, per lb. of body weight. Amount to be added to ordinary work diet per Ib.of body weight for every foot-ton of work beyond 300. Grammes per kilogramme of body weight. Amount to be added to ordinary work diet per Icilo- gramme of body weight foi' every l,OOUkilog. -metres beyond 100,000. Albuminates Fats Carbo-hydrates Salts .047 .030 .120 .010 .000107 .000068 .000166 .000020 2.9 1.9 7.6 0.6 .020 .020 .008 .004 Total .207 .000361 13.0 .042 In the case of any diet, the articles of which are known, the amounts of the four classes of alimentary principles may be calculated fi"om a table of mean composition. The following table is compiled from, in most Table for Calculating Diets. Articles. Meat of best quality, with little fat, [ like beefsteaks ) Uncooked meat of the kind supplied ^ to soldiers, — beef and mutton. ! Bone constitutes -J-th of the sol- j dier's allowance ' J Uncooked meat of fattened cattle. ^ Calculated from Lawes' and Gil- bert's experiments. These num- bers are to be used if the meat is | very fat J Cooked meat,'' roast, no dripping be- i ing lost. Boiled assumed to be > the same ) Corned beef (Chicago) ^ Salt beef (Girardin) " pork (Girardin) Fat pork (Letheby) Ik lOU Parts. Water. 74.4 75 63 54 40 49.1 44.1 39.0 Albumi- nates. 20.5 15 14 27.6 40 29.6 26.1 9.8 Fats. 3.5 8.4 19 15.45 15 0.2 7.0 48.9 Carbo- hydrates. Salts. 1.6 1.6 3.7 2.95 5 21.1 22.8 2.3 ' The gelatine of the meat is reckoned with the albuminates ; it is not certain what deduction should be made on account of its lower nutritive value, which is about one- fourth that of albumen (Bischof). '■' These numbers are taken from John Eanke's analysis. ^ This is excellent meat, palatable and nutritrious : half a pound would form an am- ple ration for the field, with the due proportion of biscuit, etc. As it is merely corned and not suited like ordinary salt meat, it is probable that its constituents may be allowed nearly their full nutritive value. FOOD. 213 Table for Calculating Diets. — Continued. Dried bacon (Letheby) Smoked liam (J. Konig) Horse flesh. (J. Konig) "VVbite fish (Lethebyj Poultry (Letheby) • Bread, 'white wheaten, of average \ quality f Wheat flour, average quality Biscuit Rice Oatmeal (Letbeby) Maize (Poggiale) (cellulose excluded) Macaroni (Konig) ... Millet (Konig) (cellulose excluded) . . Arrow-root Peas (dry) Potatoes Carrots (cellulose excluded) Cabbage Butter Egg(10 percent, mustbe deducted for ) shell from the weight of the egg) ) Cheese Milk (sp. gr. 1,029 and over) Cream (Letheby) Skimmed milk (Letheby) Sugar Pemmican (de Cbaumont) ^ In 100 Parts. 15.0 27.8 74.3 78.0 74.0 40 15 8 10 15 13.5 13.1 12.3 15.4 15 74 85 91 6 73.5 36.8 86.8 66 88 3 7.2 Albnmi- Fats. Carbo- nates hydrates. 8.8 73.3 24.0 36.5 21.7 2.6 18.1 2.9 21.0 3.8 8 1.5 49.2 11 2 70.3 15.6 1.3 73.4 5 0.8 83.2 12.6 5.6 63.0 10 6.7 64.5 9.0 0.3 76.8 11.3 8.6 67.3 0.8 83.3 22 2 53 2.0 0.16 21.0 1.6 0.25 8.4 1.8 0.5 5.8 0.3 91 1.3.5 11.6 ...'. 33.5 24.3 4 3.7 4.8 2.7 26.7 2.8 4.0 1.8 5.4 96.5 35.4 55.2 Salts. 2.9 10.1 1.0 1.0 1.2 1.3 1.7 1.7 0.5 3 1.4 0.8 2.3 0.27 2.4 1 1.0 0.7 variable taken as 2. 7 5.4 0.7 1.8 0.8 0.5 1.8 cases, several analyses by different authors, those analyses being selected which seem best to represent the food of the soldier." The mode of using the table is very simple : the quantity of uncooked meat or bread being kao'O'n, and it being assumed or proved that there is no loss in cooking, a rule-of-three brings out at once the proportions. Thus, the ration allowance of meat for soldiers being 12 ounces, 2.4 ounces, or 20 per cent., is deducted for bone, as the soldier does not get the best parts. The quantity of water in the remaining 9.6 ounces will be 75 X 9 6 — ' = 7.2, and the water-free solids will be 2.4 ounces. The albu- minates will be 1.44 ounce ; the fats, .8064 ; and the salts, ,1536 ounce. ^ The sweet pemmican used in the Arctic Expedition of 1875-76 was similar to the above (the ordinary pemmican used in the same expedition), witb tbe addition of about 5 per cent, of cane sugar. In other cases, particularly in the American pemmican, raisins and currants are added. (See Report of Committee on Scurvy for analyses by Professor Frankland and Dr. de Cbaumont.) A little pepper is added, not reckoned quantitatively in the above analysis, but probably included in the "loss," i.e., the dif- ference between the sum of tbe above constituents and 100. ■^ Of course, sucb tables are merely approximative ; but tbey are very useful as giv- ing a general idea of a diet, althougb they are not accurate enough to be used in phys- iological inquiries. 214 PRACTICAL HYGIENE. Whenever practicable, the nutritive value should be calculated on the raw substance, as the analyses of cooked food are more variable. It must then be seen that no loss occui's in cooking. In the case of salt beef or pork, it is not certain how the value should be ctilculated. The analysis by Girardin ' for uncooked salt beef (American) is given in the table, but the analysis of the brine shows that much of the nutritious matters, organic and mineral (phosj^horic acid, lactic acid, mag- nesia), have j)assed out of the meat." Liebig has reckoned the nutritive loss at one-third, or even one-half. It appears from Kiihne's observations, that myosin is soluble in a 10 per cent, solution of chloride of sodium, and hence a large quantity of this substance necessarily j^asses into the brine. Analyses show, it is true, a large percentage of tibrin and cellular tissue in salt meat, but this is made up of indigestible nitrogenous substances,•^^•hich affox'd, probably, little real nutritive material. Perhaps salt beef may be reckoned as equal to two-thii'ds the quantity of fresh beef ; this estimate is certainly quite high enough. The proportion of the nitrogenous substances to the fats, carbo-hydrates, and salts in the standard diet is as foUows : — Moleschott. Pettenkofer and Voit. Ranke. Mean. Albuminates 100 65 315 23 100 87 258 22 100 100 240 25 100 Fats 82 Cai-bo-hvdrates 272 Salts 23 Amount of Nitrogen and Carbon. — As the phenomena of nutiition are chiefly owing to the various chemical interchanges of nitrogen and carbon, and in some cases of hydrogen, with oxygen, it may be desired to calculate the amount of these constituents in any diet. This may be done in two ways. 1. Calculate out the diw albuminates, fat, and carbo-hydi-ates in ounces, and then use the following table : — Water-free constituents. Nitrogen, grains. Carbon, grains. Hydrogen, grains. Sulphur, grains. Albuminate : 1 ounce contains 1 at : 1 ounce contains 69 212 336 194 184 175 13 48 8 Carbo-hydrates : (a) Starch : 1 ounce contains (6) Cane-sugar : 1 ounce contains . . (^) 1 Glucose : } ^ °^^^ contains. . The total amount of carbon in one ounce of albuminate is 233 grains, but of this about 29 grains are converted into urea, and are therefore oxidized ' Comptes Rendus, xli., 756. ^ Liebig found that the brine is saturated with the juice of meat, and Mr. Whitelaw (Chemical News, March, 1864) has shown that extract of meat may be obtained by dialysis from the brine. FOOD. 215 only as far as carbon monoxide ; making allowance for this, we have a net total equal to 212 grains of carbon fully oxidized. 2. in the following table, the calculation of these ingredients per ounce has been made ; the substance being supposed to be in its natural state, and to have the composition already assigned to it in the former table. One ounce (=437.5 grains) contains in its natural state in grains. Substance. Carbon, Hydrogen, Sulphur, Water. Nitrogen. capable of being capable of being capable of being Salts. oxidized. oxidized. oxidized. Uncooked meat (beef) of the best quality 336 14.14 55 4.4 1.6 7 Uncooked meat as supplied to soldiers 328 10.35 60 6.0 1.2 7 Uncooked fat meat (beef) 276 9.6 94 10.9 1.1 16 Cooked meat 236 175 19.0 27.6 110 135 11.0 12.4 2.2 3.2 13 Corned beef (Chicago) 31 Salt beef 215 193 20.4 18.0 63 79 3.9 6.8 2.4 2.1 93 Salt pork 100 Fat pork 170 6.8 185 24.8 0.8 10 Dried bacon 66 122 325 341 324 6.1 16.6 15.0 12.5 14.5 265 174 55 48 57 36.8 20.6 4.0 3.7 4.5 0.7 2.0 1.7 1.5 1.7 13 Smoked ham 44 Horse flesh 4 White lish 4 Poultry 5 Bread 175 66 35 5.5 7.6 10.8 116 166 180 1.7 2.4 2.6 0.6 0.9 1.3 5 Wheat fl[our 7 Biscuit 7 Rice 44 3.5 175 3.3 0.4 2 Oatmeal 66 8.7 168 4.8 1.1 13 Maize 59 7.0 169 1.4 0.8 6 Macaroni 57 54 6.3 7.8 169 166 3.9 3.5 0.7 0.9 3 MUlet 10 Arrow-root 57 66 0.5 15.2 162 156 "3.9 i'.7 Peas (dried) 10 Potatoes 324 1.4 45 0.4 0.2 4 Carrots 372 1.1 20 0.4 0.1 4 Cabbage 398 1.3 17 0.5 0.1 3 Butter 26 0.2 312 43.7 13 Eggs 322 9.3 68 7.4 i.i 4 Cheese 161 380 23.2 2.75 153 30 16.0 3.3 3.7 0.3 24 Milk (sp. gr. 1,029 and over). . . 3 Cream .... 289 1.9 100 13.1 0.3 8 Skimmed milk 385 13 31 2.8 MA 34 178 250 1.3 31". i 0.3 3^7 3 Sugar 3 Pemmican 8 The standard daily diet for an adult man in ordinary work (Moleschott), calculated in this way, gives — Nitrogen 317 grains. Carbon 4,750 " Hydrogen 202 " > Sulphur 24 " Salts 461 " Not infrequently the standard is stated as 20 grammes of nitrogen, and 300 grammes of carbon ; this is equal to 308.6 and 4,629 grains. The usual range is from 250 to 350 grains of nitrogen for adult men. 216 PKACTICAL HYGIENE. and the extreme range is from 2 to 7 ounces of dry albuminate, or fi-om 138 grains of nitrogen (-whicli is the smallest amount necessary for the inner movements of the body, and the bare maintenance of Hfe, as calculated by Plavfaii*), to 483 or 500 gi-aias, which is the amount taken under \ev\ gi-eat exertion. Edwai-d Smith's careful observations on ill fed and fauly fed operatives, give a range of from 135 grains of nitrogen and 3,271 gi-aius of carbon (in London needlewomen) to 319 grains of nitrogen and 6,195 grains of carbon (in Iiish fann laborers). Usually, however, in what are almost starvation diets, the nitrogen is 180 to 200 gi-ains, and the carbon from 3,900 to 4,300 gi-ains (Edward Smith's investigations into the food in Lancashire during the cotton famine). In convict prisons, Dr. Wilson teUs us that the men on hght labor receive 224 gTains of nitrogen and 4,651 gi'ains of cai-bon, and this is sufficient. Those on hard labor receive 255 gi-ains of nitrogen and 5,289 grains of cai-bon, and on this diet they lose weight, and have to be continuously shifted from heavy to hghter work. In tiie case of militai-y j)risoners at hard labor even 281 gi-ains of nitrogen and 5,373 gi-ains of carbon were insufficient to prevent men losing weight. In India an improved diet was introduced by the late Surgeon-General Beatson, C.B., in which the nitrogen was about 300 grains and the carbon about 5,300. This appears to have been sufficient to jDrevent loss of weight, although there was a deficiency of fat. The carbon ranges in various diets, fi'om 3,600 to 5,800 or 6,000 grains. The amount of the salts (461) apjDeai'S rather large ; it is difficult to test it by determining the salts in the excreta, as so much sodium chloride and hme salts are lost through the skin, and some of the excreted salts may also he mere sui^Dlusage. The salts seem to be made up of chloiine, 120 gi'ains ; jihosiDhoric acid, 50 grains ; i^otash, 40 ; soda, 40 ; lime, about 4 grains by the urine (Byasson), and some by the bowels ; magnesia, 4.7 gi-ains by the imne, and a considerable amount by the bowels ; and iron, the amount of which is imcertain. Actual expeiiipent has, to a gi-eat extent, confinned the conclusicns di'a^^Ti fi'om a study of these dietaries. Pettenkofer and Yoit, in two healthy men, determined many times the amount of nitrogen during common exercise, and found it to be 19.82 gi-ammes, or 305.8 grains. Dr. Pai'kes experimented on four healthy average men in common work, and found the amount which kept them in perfect health and unifoiTQ weight was 293 to 305 grains of nitrogen in twenty-four hours. AU these deter- minations are near Moleschott's numbers. The amount of carbon is, how- ever, perhaps too large. A certain proportion between the carbon and nitrogen ought to be maintained ; in the best diets this is : Nitrogen 1 to carbon 15.' Sub-Section TL — Ox the E>*eegt Obtainable fkom the Various Articles OF Food. The possible amount of energy which can be manifested in the body ■will be the result of two conditions : first, the amount of potential energy stored up in the food, which is, c>f course, easily deteiTnined and expressed in teims of units of heat or of motion ; and second, the extent to which the processes in the body can hberate and apply this energy. For examj)le, an ounce of albumen can give rise to a certain heating eftect, if it be burnt in oxygen ; but in the body thorough oxidation can never occiu-. for some (about one-thu'd) of the constituents of the albumen pass out incompletely > The Soldier's Ration, by F. de Chaumont, Sanitary Record, February 5, 1876. FOOD. 217 oxidized in the form of ui^ea. An ounce of sugar, on the other hand, is as a general rule destroyed to the fullest extent, and ends in carbon dioxide and water, and its actual energy in the body, under whatever form it appears, is equal to its theoretical energy. One ounce of dry albuminate yields 173 foot-tons of potential energy. " fat 378 " " " starclL 138 " " " cane-sugar 131 " " " lactin or glucose 124 '• One grain of carbon (converted into CO2) 0.710 " hydrogen (water) 3.000 " " sulphur (SOo) 0.205 " " phosphorus (P2O5) 0.510 " '' carbon (forming urea) 0.198 " In the following table (page 218) Dr. Franldand's experimental results have been selected as the most exact, but they agree veiy closely with the theoretical results, particularly with those given by Playfair ' and others. Some of the numbers are calculated from the ascertained composition of the substance. A table of this kind is useful in showing what can be obtained from our food, but it must not be supposed that the value of food is in exact relation to the possible energy which it can fui-nish. In order that the energy shaU. be obtained, the food must not only be digested and taken into the body properly prepared, but its energy must be develoj)ed at the place and in the manner proper for nutrition. The mere expression of potential energy cannot fix dietetic value, which may be dependent on conditions in the body unknown to us. For example, it is quite certain, from observation, that gelatine cannot fully take the place of albumen, though its potential energy is little inferior,^ and it is easily oxidized in the body. But owing to some circumstances, yei unknown, gelatine is chiefly destroyed in the blood (?) and gland-cells, and its energy, therefore, has a different direction from that of albumen. The tables of energy give broad indications, and can be used in a general statement of the value of a diet ; but at present they do not throw light on the intricacies of nutrition. Sub-Section HL — On the Relative Value op Food of the same Class. The chemical composition of animal and vegetable albuminates is very similar, and they manifestly serve equal pui'poses in the body. The meat- eater, and the man who Hves on corn, or peas and rice, are equally well nourished. But it has been supjDosed that either the kind or the rapidity of nutrition is different, and that the man who feeds on meat, or the cai"- nivorous animal, will be more active, and more able to exert a sudden vio- lent effort, than the vegetarian, or the herbivorous animal, whose food has an equal potential energy, but which is supposed to be less easily evolved. The evidence in favor of this view seems very imperfect. The rapid move- 1 On the Food of Man in Relation to his Useful Work, 1865. • - One gramme of dry isinglass will develop 4,520 heat-units when burnt in oxygen ; one gramme of dry boiled ham, 4,343 ; one gramme of dry beef, 5,313 heat-units. (Frankland, Philos. Mag., September, 18G6, p. 169.) The potential energy of isinglass is more than that of ham, but its nutritive power is far inferior. 218 PRACTICAL HYGIENE. Energy Developed by One Ounce of the following Substances ichen Oxidized in the Body. Name of Substance. In usual state, | with the same ^ percentage of , ^^e ounce, water- water as in the I table on p. 212. free. Beef, uncooked, best quality (beefsteaks) . . . Meat, " as sui^pliecl to soldiers Beef, " fattened Meat, cooked Coraed beef (Chicago) Salt beef Foot-tons. 48.5 57.8 96.0 106.2 124.0 52.0 71.6 202.0 292.3 179.6 46.4 44.3 50.7 87.5 123.6 173.3 126.5 130.0 132.0 122.7. 125.9 116.4 118.9 33.0 14.3 13.0 344.5 67.3 149.9 26.9 109.2 20.4 126.4 270.1 30.0 41.5 Fcot-tons. 199 243 280 240 217 138 Salt pork 166 Fat pork 336 Dried bacon 346 Smoked ham 267 Horse flesh 189 White fish 209 Poultry 204 Bread 147 TNTieat floiu- 146 Biscuit 189 Rice 141 Oatmeal 154 Maize 160 Macaroni 146 MiUet 149 AiTow-root 138 Peas (dried) 151 Potatoes 141 137 Cabbage 158 Butter 367 EfTcfs . . . 265 245 Milk (cow's), new 225 365 Skimmed milk 181 128 Pemmican Stout (Guinness") 293 260 360 ments of the caraivora have been contrasted -with the slow, dull action of domestic cattle ; but, not to speak of the horse, whoever has seen the lightning movements of the wild antelope or cow, or even of the wild pig, which if: herbivorous in many cases, can doubt that vegetable feeders can exert a movement even more rapid and more endui'ing than the tiger or the wolf? And the evidence in men is the same. In India, the iU-fed EOOD. 219 people, on rice and a little millet or pea, may indeed show less power ; but take the well-fed corn-eater, or even the well-fed rice and pea-eater, and he will show, when in training, no inferiority to the meat-eaters. An argu- ment has been drawn from the compUcated ahmentary canal of the herbi- vora, but probably this is chiefly intended to digest the cellulose, and the digestion and absorption of albuminates may be as rapid as in other ani- mals. It appears from Dr. Beaumont's experiments that animal food is di- gested sooner than farinaceous, and possibly meat might therefore replace more quickly the wasted nitrogenous tissue than bread or peas ; and it may be true, as asserted, that the change of tissue is more quick in meat-eaters, who require, therefore, more frequent supplies of food. Even this, how- ever, seems not yet thoroughly proved. It has been also supposed that there is a difference in the nutrition of even such nearly allied substances as wheat and barley, but the evi- dence is imperfect, and is perhaps dependent on differences in ease of di- gestion. With respect to the fats, their differences of nutrition are probably de- pendent entu-ely on facility of digestion and absoi-ption. The animal fats aj)pear easier of absorption than the vegetable. Berthe ' found that, in addition to the fat in his ordinary diet, he could absorb 30 grammes, or 1.059 ounce of cod-liver oil, butter, or other animal oil ; in some instances If ounce were absorbed. Of vegetable oils only 20 grammes, or 0.7 ounce, were absorbed. When, in experiments with cod-liver oil, 40 grammes were taken, 31.5 were absorbed, 8.5 passed by the bowels ; when 60 grammes were taken, 48 were absorbed and 12 passed. But when he took 60 grammes daily, the amount of fat in the faeces graduaUy increased, until 50 grammes daily passed off in that way. In the dog, however, Bisch- off and Voit found that 250 and 300 grammes (8.8 and 10.5 ounces) of but- ter were easily absorbed. During the digestion of the fats they are, prob- ably, in part decomposed ; and the fatty acids, like the acids derived from the starch, must, to a certain extent, antagonize the introduction of alkah in the food. The various carbo-hydrates are generally supposed to be of equal value. Starch requires a little more preparation by the digestive fluids than grape sugar, into which it appears first to pass ; but the change is so rapid that it can hardly be made a point of difference between them. It is observable, however, that even when sugar is very cheap and accessible, it is not used to replace starch entirely ; but this, perhaps, may be a mat- ter of taste. Sub-Section IV. — The Digestibility of Food. In order that food shall be digested and absorbed, two conditions are necessary : the food must be in a fit state to be digested, and it must meet in the ahmentary canal with the chemical and physical conditions which can digest and absorb it. Fitness for digestibility depends partly on the original natiu-e of the substance, as to hardness and cohesion, or chemical nature, and partly on the manner in which it can be altered by cooking. Tables of degi'ee of digestibility have been formed by several writers, and especially by Dr. Beaumont, by direct experiment on Alexis St. Martin ; but it must be re- ' Lud wig's Phys., Band ii., p. 668. 220 PRACTICAL HYGIENE. membered that these are merely approximative, as it is so difficult to keep the conditions of cooking equal. ' Rice, tripe, Avhipped eggs, sago, tapioca, barley, boiled milk, raw eggs, lamb, i^arsnijDS, roasted and baked potatoes, and fx'icasseed chicken, are the most easily digested substances in the order here given, — the rice disap- pearing from the stomach in one hour, and the fricasseed chicken in 2f hours. Beef, pork, mutton, oysters, butter, bread, veal, boiled and roasted fowls, are rather less digestible, — roast beef disappearing from the stom- ach in three hours, and roast fowl in four hours. Salt beef and pork disap- peared in 4:^ hours. ^ As a rule, Beaumont found animal food digested sooner than farina- ceous, and in proportion to its minuteness of division and tenderness of fibre. The admixtiu-e of the different classes of food aids digestibility ; thus fat taken with meat aids the digestion of the meat ; some of the accessory foods probably increase the outpour of saliva, gastric or enteric juice, etc. The degree of fineness and division of food ; the amount of solidity and of trituration which should be left to the teeth, in order that the fluids of the mouth and salivary glands may flow out in due proportion ; the bulk of the food which should be taken at once, are points seemingly slight, but of real importance. There is another matter which appears to aff'ect di- gestibility, viz., variety of food. According to the best writers on diet, it is not enough to give the proximate dietetic substances in j^roper amount. Variety must be intro- duced into the food, and dift'erent substances of the same class must be alternately employed. It may appear singidar that this should be neces- sary ; and certainly many men, and most animals, have perfect health on a very uniform diet. Yet, there appears no doubt of the good eftect of vari- ety, and its action is probably on primary digestion. Sameness cloys ; and wdth variety, more food is taken, and a larger amount of nutriment is introduced. It is impossible, with rations, to introduce any great variety of food ; but the same object appears to be secured by having a variety of cooking. In the case of children, especially, a great imj)rovement in health takes place when variety of cooking is introduced ; and by this plan (among others). Dr. Balfour succeeded in marvellously impi'oving the health of the boys in the Duke of York's School. The internal conditions of abundance and proper composition of the alimentary fluids, and the action of the muscular fibres in moving the food, so that it shall be submitted to them, depend on the perfection of the nervous currents, the vigor of circulation, and the composition of the blood. Many of the digestive diseases the jjhysican has to treat depend on alterations in these conditions, so that the food is only imperfectly digested. Experiments, by Plusz, Maly, and Gyergyai, seem to show the value of converting the albuminates into peptones by artificial digestion, so as to aid the digestion of the sick.^ In framing diets, it is well to remember that almost every article has some portion which is more or less indigestible, but which is generally iu- ' The prepartion of food by cooking is so important a matter, that the art of cookery ought not to be considered as merely the domain of the gourmand. Health is greatly influenced by it, and it is really a sixbject to be practically studied by chemists and physiologists. ■^ An extended table is given in Cox's excellent edition of Combe's Physiology of Digestion, p. 123. •* Ueber Peptone, Arcliiv. f iir die Ges. Phys. , Band ix. , p. 333. rooD. 221 eluded in the calculation of its proximate or ultimate constituents. The proportion thus unutUized varies, but it ranges on an average from 5 to 10 per cent. Elaborate tables are given by Fliigge ' and Meinert.^ SECTION n. DISEASES CONNECTED WITH FOOD. So great is the influence of food on health, that some writers have re- duced hygiene almost to a branch of dietetics. Happiness, as well as health, is considered to be insured or imperilled by a good or improper diet, and high moral considerations are suppose(J to be involved in the due performance of digestion. If there is some exaggeration in this, there is much truth ; and doubtless, of all the agencies which affect nutrition, this is the most important. The diseases connected with food form, probably, the most numerous order which proceeds from a single class of causes ; and so important are they that a review of them is equivalent to a discussion on diseases of nutrition generally. It is of course impossible to do more here than outUne so large a topic. Diseases may be produced by alterations (excess or deficiency) in quantity ; by imperfect conditions of digestibility, and by special characters of quaUty. Sub-Section I. — Alterations in Quantity. 1. Excess of Food. — In some cases, food is taken in such excess, that it is not absorbed ; it then undergoes chemical changes in the alimentary canal, and at last putrefies ; quantities of gas (carbon dioxide, carburetted hydrogen, and hydrogen sulphide) are formed. As much as 30ib of a half-putrid mass have been got rid of by purgatives.^ Dyspepsia, constipa- tion, and irritation, causing diarrhoea, which does not always empty the bowels, are produced. Sometimes some of the putrid substances are ab- sorbed, as there are signs of evident poisoning of the blood, a febrile con- dition, torjaor and heaviness, ffetor of the breath, and sometimes possibly even jaundice. It was no doubt, cases of this kind w^hich led to the rou- tine practice of giving purgatives ; and as this condition, in a moderate de- gree, is not uncommon, the use of purgatives will probably never be dis- continued. The excess of food may be absorbed. The amount of absorption of the different alimentary principles is not precisely known. Dogs can digest an immense quantity of meat, and especially if they are fed often ; and not simply largely, once or twice a day. In men, also, much meat and albu- minous matter can be digested,^ though it is by no means uncommon, ^ Untersuchungen, etc., p. 424. '' Armee- und Volks-Ernahrung, Berlin, 1880, vol. i., pp. 129-131, in -which he quotes from Riibner (Zeitschr. f. Biologie, xv. u. xvi.) and Voit. ^ A good case of this kind is recorded by Eouth(Ffecal Fermentation, p. 19). Some convicts in Australia received from 7} to 7^ lbs of food daily. Obstinate constipation, dyspepsia, diarrhoea, skin diseases, and ophthalmia were produced. Purgatives brought away large quantities of half-putrid masses. " Jones's and especially Hammond's experiments, Experimental Researches, 1857, p. 20. 222 PRACTICAL HYGIENE. in large meat-eaters, to find much muscular fibre in the feces. Still, enough can be taken, not merely to give a large excess of nitrogen, but even to supply carbon in sufficient quantity for the Avants of the system. There is certainly a limit to the digestion of starch (though sugar, how- ever, is absorbed in large amount), as after a very large meal much starch passes unaltered. This is also the case with fat. But in all cases, habit probably much affects the degree of digestive power ; and the continued use of certain articles of diet leads to an increased formation of the fluids which digest them. "When excess of albuminates continually passes into the system, conges- tions and enlargements of the Kver, and probably other organs, and a gen- eral state of plethora, are produced. If exercise is not taken at the same time, there is a dispropc*-tion between the absorbed oxygen and the ab- sorbed albuminates, which must lead to imperfect oxidation, and therefore to retention in the body of some substances, or to iiTitation of the ehmin- ating organs by the passage through them of products less liighly elabor- ated than those they are adapted to remove. Although not completely proved, it is highly probable that gouty affec- tions arise partly in this way, partly probably from the use of hquids which delay metamorphosis, and therefore lead to the same result as increased in- gestion, and in some degree also from the use of indigestible articles of food. Vei*y often large meat-eaters are not gouty, and do not appear in any way over-fed. In this case either a great amount of exercise is taken, or, as is often the case in these persons, the meat is not absorbed, owing frequent- ly to imperfect mastication. A great excess of albuminates, -u-ithout other food, produces, in a short time (five days — Hammond) marked febrile symptoms, malaise, and diar- rhoea ; and if persevered iu, albumen appears in the ui-ine. Eanke has attributed the depression especially to the effect of the salts of the meat. Excess of starches and of fats delays the metamorphosis of the nitrogen- ous tissues and produces excess of fat. Sometimes acidity and flatidence are caused by the use of much starch. It is not understood if profounder diseases follow the excessive use of starches, unless decided corpulence is produced, when the muscular fibres of the heart and of many voluntary muscles lessen in size, and the consequences of enfeebled heart's action occirr. "WTien an excessive quantity of starch is used to replace albumi- nates, in physiological experiments, the condition becomes of course a com- plex one. If an excess of starch be taken under an}'^ cii'cumstances, much passes into the faeces, and the urine often becomes saccharine. There may be also excess of food in a given time ; that is, meals too fre- quently repeated, though the absolute quantity in twenty-foiu- houi's may not be too great. 2. Deficiency of Food. — The long catalogue of effects produced by fam- ine is but too well known, and it is unnecessary to repeat it here. But the effects produced by deficiency in any one of the four great classes of ali- ments, the other classes being in normal amount, have not yet been per- fectly studied. The complete deprivation of albuminates, without lessening of the other classes, produces marked effects only after some days. In a strong man kept only on fat and starch, Dr. Parkes found full rigor presented for five days ; in a man in whom the amount of nitrogen was reduced one half, full vigor was retained for seven days. If the abstention be prolonged, how- ever, there is eventually great loss of muscular strength, often mental debil- FOOD. 223 ity, some feverish and dyspeptic symptoms. Then follow anaemia and gi-eat prostration. The elimination of nitrogen in the form of ru-ea greatly lessens, though it never ceases, while the luic acid diminishes in a less degree. If starch be largely supphed, the weight of the body does not lessen for seven or eight days (Hammond). If the deprivation of albuminates be less complete (70 to 100 grains of nitrogen being given daily), the body gradually lessens in activity, and passes into more or less of an adynamic condition, which predisposes to the attacks of all the specific diseases (especially of malarious affections and typhus), and of jpneumonia, and modifies the course of some of these diseases as, for instance, of typhoid, which runs its course with less elevation of tem- perature than usual, and with less or with no excess of lu-eal excretion. The dej^rivation of starches can be borne for a long time if fat be given, but if both fat and starch are excluded, though albuminates be supplied, illness is joroduced in a few days. Nor is it difficult to explain this : as al- bumen contains 53.3 per cent, of total carbon (of which about 49 per cent, is available for nutrition) and 15.5 per cent, of nitrogen, to supply 3,500 grains of carbon, no less than 1,139 grains of nitrogen must be introduced, a quantity three times as great as the system can easily assimilate, unless enormous exertion be taken, and then the quantity of carbon becomes in- sufficient. Men can be fed on meat for a long time, as a good deal of fat is then introduced, and if the meat be fresh (and raw ?), scurvy is not readily in- duced. The deprivation of fat does not appear to be well borne, even if starches be given ; but the exact effects are not known. The great remedial effects produced by giving fat in many of the diseases of obscure malnutrition, prove that the partial deprivation of fat is both more common and more serious than is supposed. In all the diets ordered for soldiers, prisoners, etc., the fat is greatly deficient in every country. The depiivation of the salts is also evidently attended with marked results, which are worthy of more attention than they have yet received. Bad effects are also produced if the intervals between meals are too long ; this is a matter in which there is great individual difference, and need not be further referred to. Sub-Section II. — Conditions of Digestibility and Assimilation. A great number of diseases are produced, not by alterations in quantity or by imperfections in the quality of the raw food, but by conditions of in- digestibility, either dependent on physical or chemical conditions of the food itself, or of the digestive fluids. To some persons certain foods are indigestible at all times, or at particular times. Indigestibility leads to re- tention, and then to the results of retention, viz., chemical changes and putrefaction going on in the stomach and bowels under the influence of warmth, moistui-e, and air. Then irritation is produced, and dyspepsia, diarrhoea, or dysentery is caused. Indigestibility extends, however, farther than this. There is some rea- son for thinking that the albuminates sometimes pass into the circulation less properly prepared than usual to undergo the action of the hver, and that they therefore produce irritation of that organ, and passing into the blood in some unassimilable state, produce irritation of the skin or kidneys. Sometimes, indeed, albumen appears in the urine, as if it had circulated like a foreign body in the blood. Such conditions are usually aihed to some 224 PE ACTIO AL HYGIENE. evident error in primary digestion, but occasionally are not obviously ac- companied by any gastric disorder. "Whether there is any similar imper- fection in the digestion of starch or fat is not at present known. SuB-SeCTIOX HL CONMTIOXS OF QuALITY. Altered quality of what is otherwise good food produces a great num- ber of diseases. Most of these ai-e referred to under the headings of the different articles of food, and the subject is merely introduced here to com- plete the general sketch of the production of disease from food. In inquiring, then, into the effect of food, the following ajDpears to be the best order of procedure : — 1. Is the food excessive or deficient in quantity as a whole or in any of the piimary classes of ahments ? 2. Are the different articles digestible and assimilable, or, fi'om some cause inherent in the food or proper to the individual, is there difficulty in j^rimary digestion or want of pi-oper assimilation ? 3. Is the cjuahty of the food altered either before or after cooking ? # CHAPTER VI. QUALITY, CHOICE, AND COOKING- OF FOOD, AND DIS- EASES ATTRIBUTABLE TO IMPROPER QUALITY. SECTION I. MEAT. The advantages of meat as a diet are — its large amount of nitrogenous substance, the union of this with much fat, the presence of important salts (viz., chloride of potassium, phosjDhate, and cai'bonate of potassium, or a salt forming carbonate in incineration), and ii'on. It is also easily cooked, and is very digestible ; it is probably more easily assimilated than any vegetable, and there is a much more rapid metamorphosis of tissue in car- nivorous animals than in vegetable feeders. Whether the use of large quantities of meat increases the bodily strength or the mental faculties more than other kinds of nitrogenous food is uncertain. The great dis- advantage of meat is the vrant of starch. The composition of fi-esh and salt meat has been already given ; but the annexed table will supply further details : — ■ Composition of Fresh Beef. (Jloleschott — Jlean of all the Continental Analyses.) Water 73.4 Soluble albumen and hsematin 2.25 Insoluble albuminous substances , 15.2 Gelatinous substances , 3.3 Fat ' 2.87 Extractive matters 1.38 Kreatin 0.068 Ash 1.6 It is worthy of remark that StolzeP found 89 per cent, of carbonic acid in 100 of ash, which indicates probably lactic acid. Are the anti- scorbutic properties of fresh and raw (?) meat connected with this acid, and is it destroyed by cooking? More than one-third of the ash is composed of phosphoric acid. It is alkahne. Beef, mutton and pork form the chief meats eaten by the soldier. In time of peace he only receives as fresh meat beef and mutton, and ^ The amount of fat in this analj-sis is certainly too low. '^ Liebig's Annalen, Band Ixxvii., p. 256, Vol. I.— 15 -'2{j PBACTICAL HYGIENE. more seldom pork ; in time of war he lias salt beef and salt pork. ' The meat is supplied by contractors, or is, at some stations, furnished by the commissariat, who have theu' own slaughter-houses. The medical officer may be called on to see the animals during life, or to examine the meat. Sub-Section I. — Inspection of Animals. Animals should be inspected twenty-four hours before being killed.* — In this country killing is done twenty-four or forty-eight hours before the meat is issued ; in the tropics only ten or twelve hours previously. Animals should be well gTown, well nourished, and neither too young uor too old. The flesh of young animals is less rich in salts, fat, and syntonin, and also loses much weight (40 to 70 per cent.) in cooking. Weight. — -An ox should weigh not less than 600 lb, and will range from this to 1,200 lb. The French rules fix the minimum at 250 kilogrammes (—550 lb av.). The mean weight in France is 350 kilogrammes (=770 lb av.). A cow may weigh a few pounds less; a good fat cow will weigh from 700 to 740 ft. A heifer should weigh 350 to 400 ft. The French rules fix the minimum of the cow's weight at IGO kilogrammes ( = 352 ft). The mean weight of cows in France is 230 kilogrammes ( = 506 ft). There are several methods of determining the weight ; the one most commonly used in this country is to measure the length of the trunk from just in front of the scapulpe to the root of the tail, and the girth or circum- ference just behind the scapulte ; then multiply the square of girth by 0.08, and the product by the length, the dimensions in cubic feet are obtained ; each cubic foot is supposed to weigh 42 ft avoirdupois. The formula is (C X .08) X L X 42. An ox or cow gives about 60 per cent, of meat, exclu- sive of the head, feet, liver, lungs, and spleen, etc.^ A fuU-grown sheep will weigh from 60 to 90 ft, but the difference in different breeds is very great. It also yields about 60 per cent, of avail- able food. A fuU-growai pig weighs from 100 to 180 ft, or more, and yields about 75 to 80 per cent, of available food. Age. — The age of the ox and cow should be from three to eight years ;* the age is told chiefly by the teeth, and less perfectly by the horns. The temporary teeth are in part thi'ough at birth, and all the incisors are ' Professor Morgan of Dublin proposed tlie following plan of salting, wliicli in cer- tain cases might be nsefuUy employed : Immediately after death the thorax is opened and a pipe inserted into the left ventricle ; the pipe is connected, by an india-rubber tube, with a tank of brine placed at a few feet elevation, and through this the vessel is injected. After the blood has been driven out through the right auricle, the exit is closed, and the pressure forces the brine into the smallest ramifications of the vessels. The process is finished in ten to twenty minutes ; the meat is then cut up, dried, if necessary, in a hot-air chamber, and packed in charcoal. The injected fluid is com- posed of 1 gallon of brine to the cwt., i to ^ ft of nitre, 2 lbs of sugar, a little spice, salt, and i oz. of phosphoric acid, which serves more completely to retain the albumen, and also adds a little phosphoric acid. The brine can be used hot. This is an excellent plan, but the meat is too salt. '^ Every contract should have a clause giving officers the power of inspection. ' The animal is divided into carcass and offal; the former includes the whole of the skeleton (except the head and feet), with the muscles, membranes, vessels, and fat, and the kidneys and fat surrounding them. The offal includes the head, feet, skin, and all internal organs, except the kidneys. * Dr. Pav}' gives four years for the highest perfection of ox beef, on the authority oi; an "intelligent and experienced grazier." QUALITY, CHOICE, AISTD COOKING OF FOOD. 227 througli in twenty days ; the first, second, and third pau's of temporary molars are through in thirty days ; the teeth are grown large enough to touch each other by the sixth month ; they gradually wear and fall in eighteen months ; the foiu'th permanent molars are through at the fourth month ; the fifth at the fifteenth ; the sixth at two years. The temporary teeth begin to fall at twenty-one months, and are entii'ely replaced by the thirty- ninth to the forty -fifth month ; the order being — central pair of incisors gone at twenty-one months ; second pau' of incisors at twenty-seven months ; first and second temporary molars at thirty months ; third temporary molars at thii'ty months to three years ; third and fourth temporary in- cisors at thirty-three months to three years. The development is quite complete at fi'om five to six years. At that time the border of the incisors has been worn away a little below the level of the grinders. At six years the fii'st grinders are beginning to wear, and are on a level with the in- cisors. At eight years the wear of the first grinders is very apparent. At ten or eleven years the used surfaces of the teeth begin to bear a square mark surrounded with a white line ; and this is pronounced on all the teeth by the twelfth year ; between the twelfth and fourteenth year this mark takes a round form. The rings on the horns are less useful as guides. At ten or twelve months the first rmg appears ; at twenty months to two years, the second ; at thirty to thirty-six months, the thuxl ring ; at forty to forty-six months, the fourth ling ; at fifty-four to sixty months, the fifth ring, and so on. But at the fifth year the three first rings are indistinguishable, and at the eighth year all the rings. Besides, the dealers file the horns. In the sheep, the temporary teeth begin to appear in the first week, and fill the mouth at three months ; they are gTadually worn and fall about fif- teen or eighteen months. The fourth permanent grinders appear at three months, and the fifth pair at twenty to twenty-seven months. A common rule is " two broad teeth every year." The wear of the teeth begins to be marked about six years. The age of the pig is known up to three years by the teeth ; after that there is no certainty. The temporary teeth are complete in three or four months ; about the sixth month, the premolars, between the tusks and the first pau' of molars, appear ; in six or ten months, the tusks and posterior incisors are replaced ; in twelve months to two years, the other incisors ; the foiir permanent molars appear at six months ; the fifth pair at ten months ; and the sixth and last molars at eighteen months. Condition and Health. — There ought to be a proper amount of fat, which is best felt on the false ribs and the tuberosities of the ischia, and the line of the belly from the sternum to the pelvis ; the flesh should be tolerably firm and elastic ; the skin should be sujDple. As showing health, we should look to the general ease of movements, the quick, blight eye ; the nasal mucous membrane red, moist, and healthy-looking ; the tongue not hanging ; the respiration regular, easy ; the expired air without odor ; the circulation tranquil ; the excreta natu- ral in ajDiDearance. When sick, the coat is rough or standing ; the nostrils dry or covered with foam ; the eyes heavy; the tongue protruded; the i-espu-ation diffi- cult ; movements slow and difficult ; there may be diarrhoea ; or scanty or bloody urine, etc. In the cow the teats are hot. The diseases of cattle which the medical officer should watch for are — 1. Epidemic Pleura-pneumonia (or hmg disease). — Not easily recog- nized at first, but with marked lung symptoms after a few days. 228 PRACTICAL HYGIENE. 2. Foot and Mouth Disease (muiTain, aphtha, or eczema ei^izootica). — At once recognized by the examination of the mouth, feet, and teats. 3. Cattle Plague (typhus contagiosus, Steppe disease, Eindei-pest). — Recognized by the eai-ly prostration (hanging of head, di-ooping of ears), shivering, running from eyes, nose, and mouth, pecu- har condition of tongue and Hj)s, cessation of rumination, and then by abdominal pain, scouring, etc. 4. Anthrax (mahgnant pustule, carbuncular fever). — If boils and car- bimcles form, they are at once recognized ; if there is erysij^e- las, it is called black quarter, quarter ill, or blackleg (Eiysipelas cai'bunculosum), and is easily seen. The peculiar organism. Bacillus anthracis, may be detected. 5. Simple viftammatory affections of the lungs, bronchitis, and simple pneumonia. All have obvious symptoms. 6. Dro2:>sical affections from kidney or heart disease. 7. Indigestion, often combined with apoplectic sj-mptoms. A great number of other diseases attack cattle, which it is not necessai-y to enumerate. All the above are tolerably easily recognized. The pres- ence of Tcenia mediocanellata cannot, it would seem, be detected before death. The diseases of sheep are similar to those of cattle ; they suffer also in certain cases from splenic apoplexy or "braxy," which is considered by Professor Gamgee to be a kind of anthrax, and is said to kill 50 per cent, of all young sheep that die in Scotland ; the animals have a '' jieculiar look, staggering gait, blood-shot eyes, rapid breathing, full and fi'equent pulse, scanty secretions, and great heat of the body. " ' The small-pox in sheep (variola, ovina, c'lavelee of the French) is easily known by the flea-bitten apj)earance of the skin in the early stage, and by the rapid appearance of nodules or papulae and vesicles. The sheep is also subject to black cjuarter (Eiysipelas carbunculosum) ; one Umb is affected ; and the limp of the animal, the fever, and the raj^id swelling of the limb, are sufficient diagnostic marks. The sheep, of course, may suffer from acute lung affection, scom-ing, red water (haematuria), and many other diseases. Of the chronic lung affections, one of the most important is the so-called " phthisis," which is produced by the ova of Strongylus filaria. This entozoon has not yet been found in the muscles, and the meat is said to be good. The rot in sheep (fluke disease) is caused by the presence of Distoma hepaticum in large numbers in the liver, and sometimes by other joarasites. The princij^al symptoms are dulness, sluggislmess, followed by rapid wasting and pallor of the mucous membrane, diarrhoea, yellowness of the eyes, falling of the hair, and dropsical swellings. The animal is supposed to take in Gercaria (the embryotic stage of distoma) from the herbage. The so-called " gid," "sturdy," or " tumsick," is caused by the development of Ccenurus cere- fj7-alis in the brain. The pig is also attacked bj' anthrax in different forms, b}' tj'phoid, and by hog cholera.* The swelling in the first case, and the scom-ing, fever, ' Fifth Report of the ]\redical Officer to the Privy Council, p. 222. - Dr. Cobbold (Monthly Microscopical Journal, November, 1871) has pointed out that the pig is affected, both in America and Australia, -with a large parasite (Stephanu- rus dentatus). This worm is found cliiefly though not solely in the fat, and is at first free and then encysted ; the cyst is large, and may be If inch in length and ^ inch in diameter. The full-grown worm may be as much as IJ inch in length. Three to si.K QUALITY, CHOICE, AND COOKING OF FOOD. 229 and prostration in the second, are sufficient diagnostic marks. In 1864, a severe fever of this kind, with or without scoui-ing, prevailed among the pigs in London. The so-called measle of the pig is caused by the presence in the muscle of Gysticercus cellulosce. It is detected in the following way : — The " measle trier " throws the pig on its back, draws out and wipes the tongue, and looks and feels for the subHngual vesicles containing the Cys- ticerci. Sometimes a bit is cut out of the muscle under the tongue, and the Gysticerci are microscopically examined. A small harpoon can be used for this purpose, and gives httle pain. Sometimes the Gysticercus can be seen on the conjunctiva, or on the folds of the anus. When the disease is far advanced, the animal is dull, the eyes heav;v', appetite bad. These symp- toms are, however, not peculiar ; there is said to be sometimes tenderness in the groin (Greve), but, according to Delpech, this is very uncertain ; a better sign is a certain amount of swelling of the shoulder, which causes a sort of constriction of the neck, and somewhat impedes the movements of the animals (Delpech). The presence of Trichina spiralis is indetectable before death, unless found in the muscles under the tongue. Sub- Section IE. — Inspection of Dead Meat.* 1. FEESH jVCEAT. Meat should be inspected, in temperate climates, twenty-four hours after being killed ; in the tropics, earher. The following points must be attended to : — (a) Quantity of Bone. — In lean animals, the bone is relatively in too great proportion ; taking the whole meat, 20 per cent, should be allowed. (6) Quantity and Gharacter of the Fat. — It should be sufficient, yet not excessive, else the relative proportion of albuminous food is too low ; it should be firm, heal thy -looking, not like jelly, or too yellow ; without hemorrhage at any point. The kind of feeding has an effect on the color of the fat ; some oil-cakes give a marked yellow color. Professor Gamgee states that pigs fed on flesh have a peculiarly soft diffluent fat, and emit a strong odor from their bodies. The same au- thority tells us that the butchers will rub melted fat over the carcass of thin and diseased animals, to give the glossy look of health. (c) Gondition of the Flesh. — The muscles should be firm, and yet elastic ; not tough ; the pale moist muscle marks the young animal, the dark-colored the old one ; the muscular fasciculi are larger and coarser eggs are found in the cyst, and the young worms migrate. During their migration, it has been surmised that they cause the " hog cholera." ' In the city of London, about 1 ton in 750 tons is condemned, but much escapes detec- tion. Letheby (Lectures on Food, 2d edition, page 309) states that 700 tons of meat were destroyed in seven years; of this, 850,653 Tb were diseased, 568,375 lb were pu- trid, and 193,782 Tb were from animals which had died of accident or disease. "In the city of London, the practice is to condemn the flesh of animals infected with cer- tain parasites, such as measles and flukes, etc., and of animals suffering from fever or acute inflammatory affections, or rinderpest, pleuro-pneumonia, and the fever of par- turition, and of animals emaciated by lingering disease, and those which have died from accident or from natural causes, as well as all meat tainted with physic, or in a high state of putrefaction." (Ibid., p. 210.) It may be a question if meat should be condemned in some of these cases, as, for instance, pleuro-pnerrmonia. In India, meat with Cysficerci is now ordered to be received, but to be carefully cooked ; but it would be very difiicult to insure that proper cooking shall be always had recourse to. 230 PRACTICAL HYGIEjSTE. in bulls than oxen. A deep puiple tint is said to indicate that the animal has not been slaughtered, but has died with the blood in it (Letheby). When good meat is placed on a white plate, a httle reddish juice fre- quently flows out after some houi'S. Good meat has a marbled appear- ance from the ramifications of little veins of fat among the muscles (Letheby). There should be no li^idity on cutting across some of the muscles ; the interior of the muscle should be of the same character, or a httle paler ; there should be no softening, mucilaginous fluid, or pus, in the intennuscular celluLar tissue. This is an imporiant point, which should be closely looked to. The intermuscular tissue becomes soft, and tears easily when stretched in commencing putrefaction. The degTce of freshness of meat in commencing putrefaction is judged of by the color, which becomes paler ; by the odor, which becomes at an early stage different from the not unpleasant odor of fresh meat, and by the consistence. Afterward, the signs are mai'ked ; the odor is disa- greeable, and the color begins to turn greenish.' It is a good jjlan to push a clean knife into the flesh up to its hilt. In good meat the resist- ance is uniform ; in putrefying meat, some parts are softer than others. The smell of the knife is also a good test. Cysticerci and Trichince should be looked for. [d) Condition of the Mo.rroir. — In temperate chmates the maiTow of the hind legs is solid twenty-four houi's after killing ; it is of a hght rosy red. If it is soft, brownish, or with black points, the animal has been sick, or putrefaction is commencing. The maiTOw of the fore legs is more difflu- ent ; something like honey — of a light rosy red. [e) Condition of Lungs and Liver. — Both should be looked at to detect Sirongyhis filaria in the lungs ; Distoma in the liver ; also fnr the presence of multiple abscesses. (/; To detect cattle jjlague, the mouth, stomach, or intestines must be seen ; no alterations have as yet been pointed out in the naked -eye aj^pear- ance of the muscles, though under the microscope they are found to be degenerating like the muscles in human typhoid (Buchanan). But meat cannot be fuUy judged of till it has been cooked, so as to see how much it loses in roasting or boiling ; whether the fibres cook hard, etc. In countries where there are goats, the attached foot of the sheep should be sent in for identification. Decomposing sausages are difficult of detection until the smell alters. Artmann recommends mixing the sausage with a good deal of water, boil- ing and adding freshly prepared hme-water. Good sausages give only a faint not unpleasant, ammoniacal smell ; bad sausages give a verj' offensive, pecuhar ammoniacal odor. Microscopic Examination of Meat. In the flesh of cattle, or of the pig, Cysticerci may be found. They are generally risible to the naked eye as small round bodies ; when placed under a microscope with low power, their real nature is seen ; they are sometimes so nxunerous as to cause the flesh to crackle on section. The smallest Cysticerciis noticed by Leuckai't in the pig was about T^Tyths of an inch long and y^-oths broad ; but they are generally much larger, and will reach to y^oths or j^y ths or |ths of an inch. In some countries they are ' In diseased meat there is a disagreeable odor, sometimes a smell of physic ; very discoverable when the meat is chopped up and drenched with warm water. QUALITY, CHOICE, AND COOKING OF FOOD. 231 extremely common in cattle, and have been a source of considerable trouble in Northwest India. Cyslicercus of the ox produces in man Tcenia medio- canellata. In sheep Cobbold has described a small Cysticercus with a double crown of hooks, 26 in number. He thinks that possibly a special Tcenia may arise from this.^ In diagnosing Cysticerci of j)orkthe booklets should always be seen. Trichinoi may be present in the flesh of the pig ; if encapsuled they will be seen with the naked eye as small round specks ; but very often a micro- s3ope is necessary. A power of 50 to 100 diameters is sufficient. The best plan is to take a thin slice of flesh ; put it into liquor potassa^ (1 part to 8 of water), and let it stand for a few minutes till the muscle becomes clear ; it must not be left .too long, otherwise the TridiincE will be destroyed. The white specks come out clearly, and the worm will be seen coiled up. If the capsule is too dense to allow the worm to be seen, a drop or two of weak hydrochloric acid should be added. If the meat is very fat, a little ether or benzine may be put on it in the first place. The parts most likely to be infected are said to be the muscular part of the diaphragm, the inter- costal muscles, and the muscles of the eye and jaw.^ In diagnosing TiHchince, the coiled worm should be distinctly seen. Stephanurus dentatus in the pig ho.s been already referred to. The so-called Fsorospermia, or Eainey's capsules, must not be mistaken for Trichince, nor indeed with care is error possible. These are Uttle, al- most transparent, bodies, found in the flesh of oxen, sheep, and pigs. They are in shape oval, spindle-shaped, or sometimes one end is pointed and the other rounded, or they are kidney-shaped. The investing membrane ex- hibits delicate markings, caused by a hnear arrangement of minute, hair- hke fibres, which Mr. Rainey ^ states increase in size as the animal gets older. Tney sometimes are pointed, and the appearance under a high power (1,000 diameters) is as if the investment consisted of very dehcate, transparent, conical hairs, terminating in pointed process." The contents of the cysts consist of granular matter, the gTanules or particles of which, when mature, are oval, and which adhere together, so as to form indistinct divisions of the entu-e mass. The length varies from 3^th to ith of an inch. They are usually narrow ; they lie within the sarcolemma, and appear often not to irritate the muscle. Up to the present time no injurious effect has been known to be pro- duced on men by these bodies, notwithstanding their enormous quantities in the flesh of domestic animals, nor have they been discovered in the muscles of men. But in pigs these bodies sometimes produce decided illness ; besides general signs of illness, there are two invariable symptoms, viz., paralysis of the hind legs, and a spotty or nodular eruption.' In sheep, they have been known to affect the muscle of the gullet, and produce abscesses, or what may be called so, viz., swellings sometimes as large as a nut, and containing a milky, purulent-looking fluid, with myiiads of these capsules in it. Sheep affected in this way often die suddenly." It is by uo means improbable that some effect on man may be hereafter discovered to be produced. ' Surgeon-Major Oldham describes Cysticercus tenuicoUis (from T(^nia marginata of dog) as common in the sheep of the Punjab ; it has four -suckers and a double coronet of 82 hooks. — Indian Medical Gazette, August, 1873. 2 Lion, Comp. des Sanit.-Pol., p. 171. ^ Ph-il. Trans., 1857. ' Beale, in Third Report of the Cattle Plague Commission, Appendix. ^ Virchow's Archiv, Band xxxviii., p 355. * Leisering, in Virchow's Archiv, Band xxxvii., p. 431. 232 PRACTICAL HYGIENE. Some bodies, which have been also termed Psoro^ermia, found in the hver of the rabbit, aud other parts, and in the Hver of man, and which have been described by many observers in difterent terms,' may possibly be found in other animals, as they have been seen in the dog by \ irchow. They are quite different from Eainey's coi'puscles ; they are oval or rounded bodies, at first with gi'anular contents, and then with aggregations of gi'anules into thi'ee or four rounded bodies, on which something like a nucleolus is seen. They have often been mistaken for pus-cells. Some other bodies occur in the flesh of pigs, the nature of which is not yet known. Wiederhold ^ describes a case in which little white specks, with all the appearance at first of encapsuled Trichina', could not be proved to be so, and their real nature was quite obscure. Vii'chow has described httle concretions in the flesh of the pig, which seemed to be composed of guanin ; ^ these were also at first taken for en- capsuled Irichincp. Koloff* has noted little hard round nodules in the flesh of the jiig, some seem very small, others as large as the head of a pin, with Httle pro- longations running to the suiTounding muscular fibres to which they are attached. On the outside of these bodies are bundles of fine haii's or needles, sometimes aiTanged in quite a feather- hke form. The bodies have a great resemblance to the guanin bodies of Virchow, but the needles are not crj'stalline. Eoloff puts the question if these bodies are of post-mortem origin. It is hardly necessary to state that in cutting across meat, small bits of tendons or fascia, sometimes veiy like a little cyst, ■vsill be found ; but com- mon care will prevent a mistake. 2. SALT MEAT. It is not at all easy to judge of salt meat, and the test of cooking must often be employed. The following points should be attended to : — (a) The salting has been tvell done, but the parts inferior. — This is at once detected by taking out a good number of pieces ; those at the bottom of the cask should be looked at, as well as those at the top. [b) Ihe salting icell done, and the parts good, but the meat old. — Here the extreme hardness and toughness, and shriveUing of the meat, must guide us. It would be desirable to have the year of salting placed on the cask of salt beef or pork. (e) ITie salting well done, but the meat bad. — If the meat has partially putrefied, no salting will entirely remove its softness ; and even there may be putrefactive odor, or gi'eenish color. A shght amount of decomjiosition is arrested by the salt, and is probably indetectable. Cysticerci are not killed by salting, and can be detected. Measly pigs are said to salt badly, but according to Gamgee this is not the case. {d) The salting badly done, either from haste or bad brine. — In both cases signs of putrefaction can be detected ; the meat is paler than it should be ; often slightly greenish in color, and with a peculiar odor. It should be remembered that biine is sometimes poisonous ; this occtu'S in cases where the brine has been used several times ; a lai'ge quantity of ' Leuckart, Die Menschl. Paras, Band i., p. 740; Stieda, Virchow's Archiv, Band xxxii., p. 182 ; Roloff, Virchow's Archiv, Band xliii., p. 512. ■' Virchow's Archiv, Band xxxiii., p. 549. 2 Ibid., Band xxxv., 358. * Ibid., Band xliii., p. 524. QUALITY, CHOICE, AND COOKING OF FOOD. 233 animal substance passes into it, and appears to decompose. The special poisonous agent has not been isolated. Stjb-Sectiok he. — Diseases aeising from altered Quality of ISIeat. A Tery considerable quantity of meat from diseased animals is brought into the market, but the amount is uncertain. Instances are not at all uncommon in which persons, after partaking of butcher's meat, have been attacked vv-ith serious gasti-o-intestinal sym2Dtoms (vomiting, cUaiThcea, and even cramp), followed in some cases by severe febrile symptoms ; the whole complex of symptoms somewhat resembles cholera at first, and afterwai'd typhoid fever. The meat has been often analyzed, for the purpose of detecting poison, but none has been foimd.^ In the records of these cases, the kind of meat, the -part used, and the origin from a diseased animal, are not stated, and, in some cases, it may be con- jectured that the cooking, and not the meat, was in fault. StiU, the in- stances are becoming numerous, and are increasing every day, as attention is directed to the subject. We should conclude from general principles, that as ah diseases must affect the composition of flesh, and as the com- position of our own bodies is inextiicably blended with the composition of the substances we eat, it must be of the greatest importance for health to have these substances as pure as possible. Animal poisons may indeed be neutralized or destroyed by the processes of cooking and digestion, but the composition of muscle must exert an influence on the com]30sition of our own nitrogenousus tises which no preparation or digestion can remove. On looking through the hterature of the subject, however, we find less evidence than might be expected. This is probably partly owing to im- perfect obseiwation, especially when we think for how long a time Trichina disease was overlooked. 1 Thefiesh of healthy animals may produce Poisonous Symptoms. — This is the case with certain kinds of fish, esi3ecially in the tropical seas. There is no evidence that the animal is diseased, and the flesh is not decomposed ; it produces, however, violent symptoms of two kinds — gastro- intestinal irritation, and severe ataxic nervous symptoms, with great de- pression and algidity The Httle herring [Clupjea harengo minor), the silver-fish [Zeus gallas), the pilchard, the white flat-fish, and several others, have been known to have these effects.^ In some cases, though not in all, the poison is developed during the breeding time. Oysters (even when in season; and mussels have been known to produce similar symptoms, with- out any decomposition. The production of dysj)epsia and nettle-rash in some persons from eating shell-fish need scarcely be mentioned. Among the Mammalia the flesh of the pig sometimes causes diarrhoea — a fact noticed by Dr. Parkes in India, and often mentioned by others. The flesh is probably affected by the unwholesome garbage on which the pig feeds. Sometimes pork, not obviously diseased, has produced choleraic symptoms.^ In none of these cases has the poison been isolated. 2. The Jlesh of healthy animals ivhen decompoising is eaten sometimes ' See Professor Gamgee's paper in the Fifth Eeport of the iredical Officer to the Privy Council, 1863, p. 287. He refers to cases noted by Maclagan, Taylor, Letheby, Dundas, Thomson, and Keith. - A list of more than forty fishes, which are occasionally poisonous, is given by Pappenheim. — Hand, der Sanitats-Pol. , Band i., p. 395. ■' Kesteren cites a good case in which twelve persons were affected. — Med. Times and Gazette, March 5, 1864. 234 PRACTICAL HYGIENE. ■without danger ; but it occasionally gives rise to gastro-intestinal disorder — vomiting, diarrhoea, and gi-eat depression ; in some cases severe febiile symptoms occur, which are hke typhus, on account of the great cerebral com- plication. Cooking does not appear entii-ely to check the decomposition. It ajopears to be, in some cases, the acid fluids of cooked meat which promote this alteration. Saiisages and pork -pies, and even beefsteak-pies,' sometimes become poisonous from the formation of an as yet unknown substance, which is perhaps of a fatty nature. It is not trimethylamine, amylamine, or pheny- lamine — these are "not poisonous (Schlossberger). The symptoms are severe intestinal uiitation, followed rapidly by nervous oppression and collapse.^ Neither salts nor spices hinder the production of this poison. M. Yandem Corput attributes the poisonous effects of sausages to a fungus, of the nature of sarcina, or what he terms Sarcina botvlina." Dr. Ballard has reported two remarkable cases of poisoning by ham and hot baked pork. The first occun-ed at Welbeck in 1880, and the second at Nottingham in 1881. In both instances a number of persons who partook of the meat were taken ill, and some died. Dr. Klein examined the meat, and found it loaded with Bacilli, which were also found in the organs of the fatal cases. Gmnea-jDigs and mice, inoculated with the fluids of the body, died with pneumonia and peritonitic symjD- toms ; Bacilli were found in the organs.^ Oysters and shell-fish, when decomposing, produce also marked symp- toms of the same kind. Eotten fish are used, however, by the Biu-mese, Siamese, and Chinese as a sort of condiment, without bad effects. 3. The /re>'h and not decovipo^ing flesh of diseased animals causes in many cases injurious effects. A good deal of difference of opinion, how- ever, exists on this point, and it would seem that a more careful incjuiiy is necessai-^'. The probability is, that when attention is directed to the sub- ject, the effect of diseased meat will be found to be more considerable than at present believed.^ At the same time, we must not go beyond the facts as they are at present known to us, and at present certainly bad effects have been traced in only a few instances ; perhajDS the heat of cook- ing is the safeguard. (a) Accidents. — The flesh of animals killed on account of accidents mtij he eaten without injuiy. {b) The flesh of orer-dHven animals is said by Professor Gamgee to con- tain a poison which often produces eczema on the skin of those who handle it ; and eating the flesh is said to " have been attended with bad effects." (c) Early Stage of Acute Inflammatory Disease. — The meat is not ap- ' I have seen very severe symptoms produced, diarrhcBa and partial collapse, from eating beefsteak pie, which presented nothing unpleasant to the taste. — (F. de C.) ^ A severe case of poisoning by liver sausages took place at Middeiburg, iu Holland, in March, 1874. Nearh' 40U were attacked, and out of 343 reported cases, 6 died. The symptoms commenced a few hours after the sausages were eaten, consisting of naa'sea and vomiting, diarrhoea with offensive stools and abdominal pain and high fever. The symptoms, after apparent convalescence, recurred for several days, and at last be- came quite of an intermittent character. Chemical and microscopical examination failed to detect anj'thing, except that there were quantities of the minutest organisms in the sausages. (Centralblatt fiir die Med. Wiss., 1875, No. 14, p. 219.) ^ Quoted by Letheby, Chemical News, February, 1869. •• Eeport of tlie Medical Officer of the Local Government Board ' Professor Gamgee says that one-fifth of the meat in London is more or less diseased. QUALITY, CHOICE, AND COOKING- OF FOOD. 235 parently altered, and it is said that some of the primest meat in the Lon- don market is taken from beasts in this condition ; it is not known to be iujui'ious, bnt it has been recommended that the blood should be allowed entirely to flow out of the body, and should not be used in any wav. {d) Chronic ivasting Diseases — Phthisis, Dropsy, etc. — The flesh is pale, cooks badly, and gives rise to sickness and diarrhcea. It also soon begins to decomjDose, and then causes very severe gastro-intestinal derangement. Grave doubts have recently arisen as to whether tuberculosis may not be communicable to man tkrough the flesh of cattle suffering from that disease. ' (e) Chronic Nervous Fevers. — Same as above. . (/) Epidemic Plenro-pneumonia of Cattle. — Much doubt exists as to the effect of this disease on the meat. It is hardly possible that the flesh should not be seriously altered in composition, but it seems certain that a large quautit}' is daily consumed without apj^arent injury. It is said, on the authority of Staff-Surgeon Nicolson and Assistant-Surgeon Frank, who made very careful inqim-ies on this point, that the Kaffirs ate their cattle, when destroyed by the epidemic lung disease which prevailed at the Cape a number of years ago, without injury. Dr. Livingstone, however, states that the use of such flesh produces carbuncle. {g) Anthrax and Malignant Pustule. — Many of the older authors (Eam- azzini, Lancisi, quoted by Levy) mention facts tending ' to prove the dan- ger of using the flesh of animals affected with malignant pustule. Chaus- sier also affirmed the same thing, but subsecjuently modified his opinion considerably. The apparent increase in the number of cases of malignant pustule in men has been ascribed to eating the flesh of animals with this disease, but it is quite as likely that inoculation may have taken place in other ways. The evidence laid before the Belgian Academy of Medicine led them to beheve the flesh of cattle affected with carbuncular fevers to be inju- rious, and it is not allowed to be sold. It has been supposed that the outbreaks of boils, which have certainly become more prevalent of late years, are produced by meat of this kind, but the evidence is very imj)erfect. Menschel' has recorded a case in which twenty-four persons were seized wdth malignant pustule, the majority after eating the flesh of beasts suf- fering from the disease, the others from direct inoculation. Those who ate the flesh were attacked in three to ten days ; those who were inocu- lated in three to six days. It is also stated that jDigs fed on the flesh got the disease, and that a woman who ate some of the diseased pork was also attacked. On the other hand, several old authors, and more lately Neffel,^ assert that the Kii^ghises constantly eat horses and cattle (either killed or dying spontaneously) affected with malignant pustule, without injury. Parent-Duchatelet' quotes a case fi'om Hamel (1737), in which a buU infected three persons who aided in kilhng it, and a sui'geon who opened one of the tumors of a person affected ; yet, of more than 100 persons W'ho ate the flesh roasted and boiled, no one experienced the slightest incon- venience, and Parent states that many other cases are known in hterature. ' Creighton, on Bovine Tuberculosis in Man ; also, Transactions of the International Medical Congress, 1881, vol. iv., p. 481. ^ Preuss. Med. Zeit., 4tli June, 1862; and Canstatt's Jaliresb., 1862, Band iv., p. 257. 3 Canstatt's Jaliresb. for 1860, Band ii., p. 137. ♦ * Tom. ii., p. 196. 236 PRACTICAL HYGIENE. Parent-Ducliatelet and hC'vy' quote from Morand (1766) an instance in which two bulls commuuicated malignant pustule to two butchei-s by inoculation, yet the flesh of the animals was eaten at the "Invalides" without injury. But both these instances are of old date. Pappenheim'' states (without giving special instances) that there are many cases in which no bad ellect resulted from the cooked flesh of charbon — that the peasants of Posen eat such meat with perfect indifference, and believe it is harmless when boiled. With regard especially to eiysipelas carbuncvdosum, or black-quarter, as distinguished from malignant pustiile (if it is to be so distinguished). Professor Gamgee' refers to cases of jDoisoning, and two deaths mentioned to him by Dr. Keith of Aberdeen, caused by eating an animal aftected with black-quarter. He also notices an instance which occurred '' a num- ber of years ago in Dumfriesshu'e," when seventeen persons were more or less affected, and at least one died, and states that a number of cases have been related to him by different obsei-vers. The discrepancy of e\idence is so gi-eat as to lead to the conclusion, that the stage of the disease, or the part eaten, or the mode of cooking, must have great influence, and that a much more careful study than has yet been given to this subject is necessary to clear up these great varia- tions of statement. {h) Splenic Apojilexy or Braxy of Sheep. — Professor Simonds* states that pigs and dogs died in a few hom-s after eating the flesh of shee^D dead of braxy. Professor Gamgee^ affirms the same thing ; but, on the other hand. Dr. M'Gregor states that dogs eat the meat with perfect impunity. The experiments at Alfort" have also shown that pigs, dogs, and fowls ai-e not incommoded hj this poison, which yet acts riolently when swallowed by sheep, goats, or horses. So also Dr. Smith' states, that the shejjherds in the Highlands of Scotland eat by preference braxy sheep, and are quite healthy. Dr. M'Gregor says that the flesh of braxy sheep is never cooked until it has been steeped for two months in brine, and then suspended for a time from the kitchen roof. It is preferred to ordinary salt mutton, because it has rather a flavor of game. (i) Small-pox of Sheep. — The flesh has a peculiar nauseous smell, and is pale and moist. It produces sickness and diarrhoea, and sometimes febrile sjTuptoms. (j) Foot-and-mouth Disease {Aphtha (or Eczema) epizoofica). — Levy' states that at different times (1834, 1835, 1839) the aphthous disease has prevailed among cattle both at Paris and Lyons, Avithout the sale of the meat being inteiiaipted or giving rise to bad results. The milk of cows affected with foot-and-mouth disease has been supposed to cause vesicular aflection of the mouth in men.^ The evidence seems, however, veiy uncertain. The discharges from the mouth are constantly on the hands of the fann laborers, who are not very cleanly, and who must constantly convey them to their own mouths, and yet these discharges, so infectious to other cattle, produce no effect on them. (k) Cattle Plague (Einderpest, Typhus contagiosus of the French). — A priori, such flesh would be considered highly dangerous, and the Belgian ' Traite d'Hygil-ne, 1879, torn, ii., p. 680. - Handb. der"Sanitats-Pol., Band i., p. 587. ' Fifth Eeport of Medical Officer to the Privy Council, p. 290. * Agricultural Journal, No. 50, p. 232. ^'Privv Council Repiort, 1863, p. 280. « Levy, t. ii., p. 631. ' Social Science Trans, for 1863, p. 559. « Traite d'Hygiene, 1879, t. ii., p. 631. « Jour, of the Epid. Soc, vol. i., p. 423. QUALITY, CHOICE, AND COOKING OF FOOD. 237 Academy of Medicine so consider it ; but there is some strong evidence on the other side. In Strasbourg and in Paris, in 1814, many of the beasts eaten in those cities for several months had rinderpest, and yet no iU con- sequences were traced. But it may be questioned whether they were looked for in that careful way they would be at the present day. ' Some other evidence is stronger : Renault, the director of the Veterinary School at Alfort, made for several years after 1828 many experiments, and asserts that there is no danger from the cooked flesh of cattle, pigs, or sheep dead of any contagious disease ("quelle que soit la repugnance bien naturelle que puissent inspirer ces produits").' So also during the occurrence of the rinderpest in England (1865), large quantities of the meat of animals liiUed in all stages of the disease were eaten without ill effects. In Bohemia also, in 1 863, the peasants dug up the animals dead with rinderpest, and ate them without bad results.^ (l) Rabies in the dog and cow produces no bad effects.* [m) Diseases in the pig, like scarlet fever and pit/ tyjjhus, have prevailed recent!}' in London, and the flesh has been eaten. No injury has been proved. ^ (n) Cysticercus ceUulosce of the pig produces Tcenia solium, and that of the ox and cow Tcenia inediocaneliata. These entozoa often arise from "eating the raw meat, but neither cooking nor salting are quite preservative, though they may lessen the danger. Smokmg appears to kill Gysticerci, and so, according to DeljDech, does a temperature of 212° Fahr. T. Lewis'^ found that a much lower temperature sufficed. When Gysticerci had been exposed for five minutes to a heat of 130° Fahr., he could detect no move- ments, and he considers that a temperature of from 135° to 140° F. for five minutes would certainly kill them. Lewis considers there is no danger if the cooking is well done, as the temperature of well-done meat is never below 150° F. (o) Trichina spiralis in the pig gives rise to the curious Trichina disease caused by the wanderings of the young Trichina; . The affection is highly febrile, resembling typhoid or even typhus, or acute tuberculosis, but at- tended with excessive paias in the limbs, and oedema.' Boils are also sometimes caused. The eating of raw trichiniferous pork is the chief cause, and the entozoon is not easily killed by cooking or salting. A tem- perature of 144° to 155° Fahr. kills free Trichince, but encapsuled Trichince may demand a greater heat (Fiedler). During cooking, a temperature which will coagulate albumen (150° to 155° Fahr.) renders Trie/mice in- capable of propagation, or destroys them. As a jDractical rule, it may be said that if the interior of a piece of boiled or roasted pork retains much ' The words of Coze (Parent-Duchatelet, t. xi., p. 201) are, however, very strong. At Strasbourg he says : ' ' Un millier de boeuf s de grande taille, malades pour la plupart au plus haut degre, pnisqu'un assez grand nombre ont ete egorges au moment ou ils allaient expirer, a ete consomme, pendant et apres le blocus, et eet aliment n'a produit aucune maladie." - Payen, Des Substances Alimentaires, pp. 30, 31. ^ Evidence of Cattle Plague Commission, question 997, and other places. ■* Parent-Duchatelet, t ii., p. 197, cites a case of seven mad cows being sold without injury to those who ate the flesh. ^ Letheby, Chem. News, January 15, 1869. «The Bladder Worms found in Beef and Pork, by T. R. Lewis, M.D., Calcutta, 1872. ' Aitken's Practice of Medicine, 7th edit., vol. i., p. 162. See also reports on Hy- giene by the late Dr. Parkes, in the Army Medical Reports for 1860, 1861, 1862, and 1868, where references to most of the early cases will be found. See also Dr. Thudi- chum's treatise in Mr. Simon's Report to the Privy Council, 1864. 238 PRACTICAL HYGIENE. of the blood-red color of uncooked meat, the temperature has not been higher than 131° Fahr., and there is still danger. Intense cold and com- I^lete decomposition of the meat do not destroy Trichince.^ Hot smoking, when tlioroughly done, does destroy them (Leuckart) ; but the common kinds of smoking, when the heat is often low, do not touch Trichince (K ii chenmeister ). (p) Echinococcus Disease. — It is well known that many persons w^iU eat freely of, and even prefer, the hver of the sheeji full of Hukes. No direct evidence has been given of the production of disease from this cause, at least in this countiy. In Iceland, Echinococcus disease, which affects a large number of persons, is derived from sheep and cattle, who, in their turn, get the disease from Tcenia of the dog (Leared and Krabbe). {q) Glanders and farcy in horses do not appear to produce any injurious effects on theu- flesh w^hen eaten as food. Parent-Duchatelet" quotes two instances, in one of which 300 glandered horses were eaten without injury. In 1870, during the siege of Paris, large quantities of flesh from horses with farcy and glanders were eaten without injury. (?•) Medicines, especially antimony,'' given to the animals in large quan- tities, have sometimes produced vomiting and diarrhcea. Arsenic, also, is occasionally given, and the flesh may contain emough arsenic to be dan- gerous.'' In time of peace, the dut}' of the army surgeon is simple. Under the terms of the contract, all sick beasts are necessarily excluded. Without reference, then, to any uncertain questions of hurtfulness, or the reverse, he must object to the use of the flesh of such animals. This is the safe and projDer course. But, in time of war, he may be placed in the dilemma of allowing such meat to be used, or of getting none at all. He should then allow the issue of the meat of all animals ill with inflammatory and contagious diseases, with the exception of small-pox, and perhaps splenic apoplex}- in sheep. But it will be well to take the precautions — 1st, Of bleeding the animals as thoroughly as possible ; 2d, Of using only the muscles, and not the organs, as it is quite possible these may be more injiuious than the mus- cles, though there are no decided facts on this point ; and, 3d, Of seeing that the cooking is thoroughly done. But animals with small-pox, Gysti- cerci, and Trichince, should not be used. If dire necessity compels their use, then the employment of a gi-eat heat in a baker's oven and smoking", if it can be used, may lessen the danger. If such things can be got, it would be well to try the effect on the meat of antiseptics, especially of carboHc acid, which destroys low animal life of that kind with great cer- tainty. Sub-Section TV. — Cooking of Meat. Boiling. — The loss of weight is about 20 to 80 per cent., sometimes as much as 40. If it is wished to retain as much as possible of the salts and ' Carre (Comptes Rendus, xcv., p. 147) saj'S that tliey are destroyed at 40" to 50° below zero of Centicrade (= 40 to 58" below zero of Fahrenheit). '' Hyg. Publ., t. Ii., 194 ; see also Levy, t. ii., p. 630. ^ See a well-marked case cited by Pavy (A Treatise on Food and Dietetics, 2d ed. , 1875, p. 160), as quoted by Gamgee, from the Central Zeitung fiir die gesaminte Yeter- inrirmedizin fiir 1854, where 107 persons were attacked after eating the flesh of an ox which had been treated with tartar-emetic previous to being slaughtered. ■■ Levy, Traite d'Hygieue, 1879, t. ii., pp. 663-4; reference to experiments of Dan- ger, Flandin, and Chatin. QUALITY, CHOICE, AN^D COOKING OF FOOD. 239 soluble substances in the meat, the piece should be left large, and should be plunged into boihng water for five minutes to coagulate the albumen. After this the heat can scarcely be too low. The temperature of coagula- tion of the albuminoid substances differs in the different constituents ; one kind of albumen coagulates at as low a heat as 86°, if the muscle seiiim be very acid ; another albumen coagulates at 113° Fahr. ; a large quantity of albumen coagulates at 167°. The hsematogiobulin coagulates at 158° to 162°, below which temperature the meat will be underdone. If the tem- perature is kept above 170°, the muscular tissue shrinks, and becomes hard and indigestible. Liebig recommends a temperature of 158° to 160°. Most military cooks employ too great a heat : the meat is shrunken and hard. In boiling, ammonium sulphide is evolved, with odoriferous compounds, and an acid hke acetic acid. If it is desired to make good broth, the meat is cut small and put into cold water, and then warmed to 150° Y.; beef gives the weakest broth. In a pint there are about 150 grains of organic matter, and 90 grains of salts. Mutton broth is a little stronger, and chicken broth strongest of all. About 82 per cent, of the salts of beef pass into the broth, viz., all the chlorides, and most of the phosphates. Broth made without heat, by the addition of four drops of hydrochloric acid to a pint of water and a half pound of beef, is richer in soluble albu- men. Lactic acid and chloride of potassium added together have the same effect. If rather more hydrochloric acid be used, but no salt, heat can be apphed, and, if not higher than 130° Fahr., nearly 50 jDer cent, of the meat can be obtained in the broth. Boasting. — The loss varies from 20 to 35 per cent.; in beef it is rather less than in mutton (Oesterlen). This loss is chiefly water ; the j)roportion of carbon, hydrogen, nitrogen, and oxygen remaining the same (Playfair). Boasting should be slowly done ; to retain the juices, the meat must be first subjected to an intense heat, and afterward cooked very slowly ; the dry distillation forms aromatic products, which are in part volatihzed ; the fat is in part melted, and flows out with gelatin and altered extractive matters. The fat often, improperly, becomes the perquisite of the cook, and may be lost to the soldier. The loss in baking is nearly the same, or a Httle less. Stewing. — This is virtually the same as roasting, only the meat is cut up, is continually moistened with its own juices, and is often mixed with vegetables. Like boiling and roasting, it should be done slowly, at a low heat ; the loss then is about 20 per cent., and chiefly water. In all cases there is one grand rule, viz., to cook the meat slowly, and with little heat, and, as far as possible, to let the loss be water only. The fault in military kitchens has been, that excessive heat is used. The meat is then often a sodden, tasteless mass, with hard, shrunken, and indigest- ible fibres. The thermometer will be found very useful, especiaUy in showing cooks that the temperature is often much higher than they think. In the cooking of salt meat, the heat should be very slowly aj)phed, and long continued ; it is said that the addition of a little vinegar softens the hard sarcolemma, and it is certain that vinegar is an agreeable condiment to take with salt meat, and is probably very useful. It may be of impor- tance to remember this in time of war. In cutting up meat, there is a loss of about 5 per cent., and there is also a loss from bone, so that, all deductions being made, the soldier does not get more than 5 or 6 ounces of cooked meat out of 12 ounces. The large quantity of flesh extract contained in the bx'ine can be ob- 240 PRACTICAL HYGIENE. tained hj dialysis ; from two gallons of brine a fluid has been obtained, which, on evaporation, yielded 1 lb of extract.' Sub-Section V. — Preservation of Meat. Meat may be kept for some time by simjDly heating the outside very strongly, so as to coagulate the albumen ; or by placing it in a close vessel, in which sulphur is burnt, or by covering the surface with charcoal, or strong acetic acid, or calcium disulphite, or weak carbolic acid. Injections of alum and aluminium chloride through the vessels will preserve it for a long time ; water should be injected first, and then the solution. Even common salt injected in the same way will keep it for some time. So also will free exposure to pure air ; charcoal thrown over it, and suspended also in the air ; or the meat being cut into smaller portions, and placed in a large vessel, heat should be applied, and, while hot, the mouth of the vessel should be closed tightly with well washed and dried cotton-wool ; the air is filtered, and partially freed from germs. The application of sugar to the sui'face is also a good plan. Cold is a great preservative of meat ; in ice it can be jireserved for an unlimited period, and the suj)posed rapid decom- position after thawing seems to have been exaggerated.' Fresh meat is now largely imported from America and Austraha, by being kept in refrig- erated chambers. Plans of this kind may be useful to medical officers under two circum- stances, \iz., on board ship, and in sieges, when it is of imj)ortance to pre- sei-ve eveiy portion of food as long as possible. The covering the whole surface with powdered charcoal is perhaps as convenient as any plan. A coating of paraffin, and many other plans of excluding au', are also used. Meat is also jDreserved in tin cases, either simply by the complete ex- elusion of air (Appert's process), or by partly excluding air, and destroying the oxygen of the remaining part by sodium sulphite (M'Call's process). It is not necessary^ to raise the heat so high in this case, and the meat is less sapid. Meat prepared in either way has, it is said, given rise to diar- rhoea, but this is simply from bad preparation ; when well manufactured it has not this eifect. Meat is also preserved by drawing off the air from the case, and sub- stituting niti'ogen and a little sulphur dioxide (Jones and Trevithick's patent), or the air can be heated to 400° or 500° so as to kill all germs (Pasteur), and then allowed to flow into an exhausted flask. ^ Various other plans have been proposed, such as the use of antiseptics, carbohc acid (?), borax, boracic acid, salicylic acid, etc. ; but it is doubtful if any of them should be adopted ^\^.thout further inquiry, as it is by no means certain that such agents might not exercise a harinful influence on the human economy.^ ' Whitelaw, Chemical News, March, 1864. • Bonley, Comptes Rendus. xcv., p. 147. ' Dr. Letheby's Cantor Lectures on Food, delivered before the Society of Arts in I860, 2d edition, 1872, give a good account of some of the patents for the preserva- tion of meat. See also Meinert, Armee- und Volks-Erniihrung, Berlin, 1880, vol. ii., p. 205 ; also Renk, Conservirung von Nahrungsmitteln, Deutsche Vierteljahrschr. f. off. Gesundheitspfl. , Band xiii., Heft 1. * A substance called Glacialin has been recommended : this consists of borax, bor- acic acid, sugar, and glycerin. The two latter are preservative of themselves, so that the addition of the former seems superfluous. The mixture of borates with glycerin has also been recommended by Le Bon in France and Barff in England. QUALITY, CHOICE, AND COOKING OF FOOD. 241 SECTION n. WHEAT. Advantages as an Article of Diet. — ^It is poor in water and rich in solids, therefore very nutritious in small bulk ; when the two outer coats are separated, the whole grain is digestible. The nitrogenous substances are large and varied,' consisting of soluble albumen (1 to 2 per cent.) and gluten (8 to 12 per cent.), which itself consists of four substances, which are named by Eitthausen,^ glutin-casein, ghadin (or vegetable gelatin), giutin-fibrin, and mucedin. The starchy substances (starch, dextrin, sugai*) ai'e large, 60 to 70 per cent., and are easily digested ; and, according to Mege-Mouries, a nitrogenous substance (cereahn) is contained in the in- ternal envelope, which, like diastase, acts energetically in transforming starch into dextrin, sugar, and lactic acid. Some consider this cerealin to be merely a form of diastase. Cholestrin is found in wheat, but in very small quantity (Ritthausen). The salts are chiefly phosphates of potash and magnesia. Disadvantages. — It is deficient in fat, and in vegetable salts which may form carbonates in the system. As usually prepared, the grain is separated into flour and bran ; the mean being 80 parts of flour, 16 of bran, and 4 of loss. The flour is itself divided into best or supei-fine, seconds or middlings, pollards or thirds or bran flour. In different districts different names are used. The wheats of commerce are named fi-om color or consistence (hard or soft ; white or red) ; the hard wheat contains less water, less starch, and more gluten than the soft wheat. Sub-Section I. — "Wheat Grains. The medical officer will seldom be called on to examine wheat grains, but if so, the following points should be attended to. The grains should be well filled out, of not too dark a color ; the furrow should not be too deep ; there should be no smell, no discoloration, and no evidence of insects or fungi. The heavier the weight the better. In the Belgian army the minimum weight is 77 kilogrammes the hectolitre.^ In England, good wheat weighs 60 lb to the bushel ; light wheat 58 lb or even 50 lb. Fungi, if present, will be found at the roots of the hairs, and if in small amount, are only microscopic. If in large amoimt they cause the diseases known by the name of rust, bunt or smut, or dust brand ; they are owing to species of Uredo and Puccinia. If any grains are seen pierced with a hole, and on examination are found to be a mere shell, with all the starch gone, this is owing to the weevil, and the little insect can itself be found readily enough if a handful of wheat be taken and spread over a large plate. The weevil can hardly escape being seen. Acarusfarlnce may also prey on the wheat grain, but cannot be seen without a microscope. ' These reach. 14 to 15 per cent., especially in the hard wheats of Italy and Sicily, which are used for macaroni (Letheby). •^ Die Eiweisskorper der Getreidearten, von Dr. H. Ritthausen, 1872. 3 Squillier, Des Subsist. Mil., p. 37. Vol. I.— 16 242 PRACTICAL HYGIENE. Sub-Section II. — Flour.' Almost all the bran is separated from the finest flour ; it has been a question whether this is desu-able, as the bran contains nitrogenous mat- ter — as much sometimes as 15 per cent, "with 3.5 per cent, of fat, and 5.7 per cent, of salts. But if the bran is used, it seems probable that much is left undigested, and all the nuti-iment which is contained in it is not ex- tracted. A plan has been employed by Mege-Mouries, which seems to save all the most valuable parts of the bran ; the two or three outer and highly sihceous envelopes of the wheat are detached, and the fourth or in- ternal envelope is left. Several plans of decorticating wheat have been proposed, but none of them at present have superseded the old system of grinding. If the whole wheat is used, it should be ground very fine, as the harder envelopes are very irritating, and it is well to remember that for sick per- sons with any bowel complaints bread must be used entirely without bran. Dysenteries have been found most intractable, merely from attention not being directed to this simple point. It is all the more necessary to insist upon this, as whole meal bread has been much recommended and used of late. Examination of Flour for Quality and Adulteration. Flour should be examined physically, microscopically, chemically, and practically by making bread. The quality is best determined by chemical examination ; adulterations by the microscope. Physical Examination. Sight. — The starch shoidd be quite white, or with the very slightest tinge of yellow ; any decided yellow indicates commencing changes ; the amount of bran should not be great. Touch. — There should be no lumps, or if there are, they shoidd at once break down on slight pressure ; there must be no grittiness, which shows that the starch grains are changing, and adhering too strongly to each other, and will give an acid bread. There should, however, be a certain amount of adhesion when a handful of floui- is compressed, and if thrown ' The follQwing is given by Peligot (mean of 14 analyses), as the relative composi- tion of flour and bran. The analyses of Von Bibra (Die Getreidearten und das Brod, 1860) agree very closely with it. Wheat Flour and Bran. i" i?0 parts. Flour. Bran. Water 14.0 10.3 Fatty matters 1-2 2.82 Nitrogenous substances insoluble in water (gluten). , 12.8 10.84 Nitrogenous substances soluble in water (albumen). . 1.8 1.64 Non-nitrogenous soluble substances (dextrin, sugar). 7.2 5.8 Starch.... 59.7 22.02 Cellulose 1-7 43.98-' Salts 1-6 2.52 2 ThiH is, however, the cellulose of the entire prain, both of the husk and the interior of the grain. Pot- ash, pliosphoric acid, and magnepia are the principal ingredients of tlio salts ; the earthy phosphates are especially combined, and in definite proportions, with the albuminates (Mayer), and also the gummy matter (Bibra). The alkaline phosphates are free. The bran contains much silica. Oudemans places the cellulose lower (25 to 30 per cent.), and the salts higher (4 to 6 per cent.). QUALITY, CHOICE, AND COOKHiTG OF FOOD. 243 against a wall or board some of the floux should adhere. When made into a paste with water, the dough must be coherent, and draw out easily into strings. Taste. — The taste must not be acid, though the best flour is slightly acid to test-paper. An acid taste, showing lactic or acetic acid, is sure to give an acid bread. Smell. — There must be no smell of feiTnentation or mouldiness. Age of flour is shown by color, grittiaess, and acidity. Chemical Examination. It is seldom that a medical officer will be able to go through a com- plete examination, but he should always determine the foUov^ing points : — 1. Amount of Water. — Weigh 1 gTamme, spread it out on a dish, and dry either by a water bath or in a hot-au* bath or oven, the temperature not being allowed to go above 212°. The flour must not be at all burnt or much darkened in coloi\ Weigh directly the flour is cold ; the loss is the percentage of water. The range of water is from 10 (in the best dried flours) to 18 in the worst. The more water the greater hability of change in the flour, and, of course, the less is the amount of nutriment purchased in a given weight. If, then, the water be over 18 per cent., the flour should be re- jected ; if over 16, it should be unfavorably spoken of. 2. Amount of Gluten. — Weigh 10 grammes, and mix, by means of a glass rod, with a little water, so as to make a well-mixed dough ; let it stand for quarter of an hour in an evaporating dish ; then pour a little water on it ; work it about with the rod, and carefully wash off the starch ; pour off from time to time the starch water into another vessel. After a tune, the gluten becomes so coherent, that it may be taken in the fingers and worked about in water, the water being from time to time poured off till it comes off quite clear. If there is not time to diy the gluten, then weigh ; the dry gluten is rather more than one-third the weight of the moist ; 1 to 2. 9 is the usual proportion ; therefore divide the weight of the moist gluten by 2.9. If there be time, dry the gluten thoroughly, and weigh it. This is best done by spreading it out on a crucible lid and drying it in the bath. The dry gluten ranges fi'om 8 to 12 per cent. ; flour should be rejected in which it falls below 8. If there is much bran, it often apparently increases the amount of gluten by adher- ing to it, and should be separated if possible ; in fact, the gluten, as thus obtained, is never pure, but always contains some bran, starch, and fat. The gluten should be able to be drawn out into long threads ; the more extensible it is the better. It is always well to make two determinations of gluten, especially if there is any disputed question of quality.' 3. Amount of Ash. — Take 10 grammes," put into a porcelain or plati- num crucible, and incinerate to white ash. Weigh. The ash should not be more than 2 per cent., or probably some mineral substances have been added ; it should not be less than .8, or the flour is too poor in salts. The incineration of the flour requires a crucible and gas. It is diffi- cult to do it over a spirit lamp, as it takes a long time. A small charcoal fire is probably the best plan when gas appliances are wanting. ' Mr. Wanklyn lias proposed to utilize the albumiuoid ammonia process for deter- mining gluten, reckoning that 100 parts of flour yield 1.2 of ammonia. ■ If only a small crucible be employed a smaller quantity should be taken, as it is difficult to incinerate ; with a moderately good balance, 2 or 3 grammes may be used. 244 PRACTICAL HYGIENE. If the ash be more than 2 per cent., add hydrochloric acid, and see if there be effervescence (magnesium or calcium carbonate). Dissolve, and test with oxalate of ammonium, and then for magnesia, in the same way as in water. As floui- contains both Ume and magnesia, to prove adultera- tion, the precise amount of lime and magnesia must be determined by weighing the incinerated calcium oxalate, or the magnesium pyrophos- phate. If there is no effervescence, add water, and test for sulphuric acid and lime, to see if calcium sulphate (plaster of Paris) has been added. In nor- mal flour the amount of sulphuric acid is veiy smaD. Notice, also, if the ash be red (from iron). If clay has been added, it will be left undissolved by acids and water. If magnesium carbonate has been added, the ash is light, and porous and bulky (Hassall). An easy mode of detecting large quantities of added mineral substances is given by Redtenbacher ; the flour is strongly shaken with chloroform ; the flour floats, while all foreign mineral substances fall. This is a very useftd test.' If the water be small, the gluten large, and the salts in good quantity, the flour is good, supposing nothing is detected on microscopical exam- ination. But in all cases it is well, if time can be spared, to have a loaf made. Practical Test hy Baking. — Make a loaf, and see if it is acid when fresh, and how soon it becomes so ; if the color is good, and the rising satisfac- tory. Old and changing flour does not rise well, gives a yello-ndsh color to the bread, and speedily becomes acid. Excess of acidity can be detected by Jiolding a piece of bread in the mouth for some time, as well as by test- paper. Ted for Ergot. — There is no very good test for ergot when it is ground up with the floiu'. Laneau's plan is to make a paste with a weak alkaline solution ; to add dilute nitric acid to slight excess, and then alkali to neutralization ; a violet-red color is said to be given if ergot is present, which becomes rosy-red when more nitric acid is added, and violet when alkali is added. Wittstein considers this method imperfect, and prefers trusting to the peculiar odor of propylamine (herring-Hke smell), developed by liquor potassse in ergoted flour. Microscopical Examination. This is especially directed to determine the relative amount of flour and bran, the presence of fungi or acari, or the fact of adulteration by other grains. In examining wheat, or any other cereal grains, it is necessary to pre- pare them beforehand by soaking for some time in water. It will then be found easy to demonstrate the different stmctm-es. By means of a needle and a pair of fine forceps the different coats can be removed seriatim, some- times quite separately, but generally more or less in combination. The only one that presents any diflSculty is the thu'd coat of wheat or barley, ' The remaining ingredients can be determined, if necessary, from the starch water, but it is seldom necessary to do so. Allow the starch to subside, pour off the fluid, and wash the starch by decantation, then dry and weigh ; take all the water and washings, evaporate to a small bulk, add a little nitric acid, and boil ; albumen is thrown down ; collect, wash, and weigh. Evaporate the whole of the remainder to dryness, and weigh (mixed dextrin and sugar). QUALITY, CHOICE, AND COOKIXG OF FOOD. 245 but generally it can be found accompanring the second or fourtli coats. In In the case of barley, the proper external envelope of the grain sometimes adheres to the interior of the husk, where it ought to be looked for in the event of its not being on the siu'face of the grain itself. After examining the separate coats, sections may be made of the whole grain, so as to see Fig. 23. — Transverse Section of Envelopes of Wheat. Scale 1.000:h of an Inch. the structures in situ. The hairs are generally found in a bunch at the end of the gi'ain. The starch grains are best demonstrated bv picking out a little from the centre of the grain ; mixed glycerin and water form the best medium for demonstration. Strv.rdure of the Wheat Grain. — There are four envelopes (some authors make three, others five or six — the outer coat being divided into two or fffffff^^rx^ ^ Pig. 24.— Envelopes of Wheat (longitudinal section). Scale 1,000th of an inch. three) surrounding a fine and very loose areolar tissue of cellulose filled with starch grains. Envelope;^ of Wheat. — The drawings show the coats f/r .situ, cut transversely and longitudinally, also the separate coats. The outer coat is made up of Fig. 25. —Outer Coat and Hairs of Wheat. Scale 100th of an inch. two or three layers of long cells, with sHghtly beaded walls, i-unning in the direction of the axis of the grain. The septa are straight or oblique, and, as will be seen, the cells differ in length and breadth. The size can be 246 PRACTICAL HYGIETiTE. taken by the scale. The hairs are attached to this coat, and are prolonga- tions, in fact, of the cells. In the finest flour the hairs and bits of this coat (as well of the other coats) can be found. The second coat, counting from without, is composed of a layer of shorter cells, more regular in size, with sHghtly rounded ends and beaded Fia. 26. — Outer Coat and Halts of Wheat. Scale l.CWOth of an inch. walls, and lying at right angles to the first coat, or across the axis of the gi-ain. It is impossible to mistake it. The third coat is a delicate diapha- nous, almost hyaline membrane, so fine that its existence was formerly doubted. Dr. Maddox, however, has distinctly shown it to have faint Hnes Fig. 27.— Second and Third Envelopes of Wheat, Scale l,C0Oth of an inch. crossing each other diagonally as seen in the drawing, which may be cells. "With a Httle care, it is veiy easily demonstrated. In the transverse section of the envelope it appears as a thin white line. Internal, again, to this QUALITY, CHOICE, AND COOKING OF FOOD. 247 coat what appears to be another coat can sometimes be made out ; it is a very fine membrane, marked with widely separated curved Unes, which look like the outlines of large round or oval cells. The internal or fourth coat, as it is usually called, is composed of one or two layers (in places) of rounded or squarish cells filled with a dark substance which can be emp- tied from the cells. When the cells are empty, they have a remote re- FlG. 28.— Fourth Envelope of Wheat. Scale 1,000th of an inch. Fig. 99. — Fresh Starch Grains of Wheat (moistened). x360. semblance to the areolar tissue of the leguminosse, and there is little doubt that from this cause adulteration with pea or bean has been sometimes im- properly asserted. The starch grains of wheat are very variable in size, the smallest being almost mere points, the largest ^oWth of an inch in diameter or larger. In shape the smallest are round ; the largest round, oval, or lenttcular. It has been well noticed bv HassaU that there is often a singular want of Fig. so.— Dried and then moistened Starch Grains of Wheat. Scale 1,000th of an inch. intermediate -sized grains. The hilum, when it can be seen, is central, the concentric lines are perceived with difficulty, and only in a small number ; the edge of the grain is sometimes turned over so as to cause the appeai"- ance of a slight furrow or line along the grain. Very weak liquor potassae causes little sweUings ; strong liquor potassse bulges them out, and eventu- ally destroys them. There is no difficulty in seeing if the pieces of envelope are too numerous, but it should be remembered the best flour contains some. 248 PRACTICAL HYGIENE. Diseases of Flour. Fungi. — Several fungi are found in wbeat-flour. The most common fungus is a species of Puccinia. It is easily recognized by its round dark sporangia, which are either contoured with a double line, or are covered Fig. 31. — Diseased Flonr (Puccinia). with little projections. It is said not to be injurious by some, but this is veiy doubtful. The symptoms have not been well described. The smut, or caries, is also a species of Puccinia ; has large sporules, and gives a disagi-eeable smell to the flour, and a bluish color to the bread. It is said to produce diaiThoea. Acarus. — Acarus farince is by no means uncommon in inferior flour, Fig. Z^.—Acarvs farina. ( x 85 diameters).— Mites found in flour alive. In the largest figures, the insects are coneiderably compressed, to show the powerful mandibles, and have each a ventral aspect. In the small- est and middle-sized insect, we have drawn the dorsal aspect; the former only possesses six less, as before the first moult ; several ova lie scattered in the field of view. It is unknown what offlce the capsular organs fulfil. They are well seen on each side of the largest figure. especially if it is damp. It does not necessarily indicate that leguminous seeds are present, as stated. It is no doubt introduced from the grain in the mill, as it has been found adhering to the grain itself. It is at once recognized. Portions of the skin aa-e also sometimes found. QUALITY, CHOICE, AXD COOKIT^-G OF FOOD. 249 Vibriones, — These form for the most part in flour -which has gone to extreme decomposition, and which is moist and becoming discolored. They cannot be mistaken. The presence of Acari always shows that the flour is beginning to change. A single acarus may occasionally be found in good floiu', but even one should be looked on with suspicion, and the floui- should be afterward frequently examined to see if they are increasing. Weevil {Calandra granaria). — The weevil is of course at once detected. It is by no means so common in flour as in com. M Fig. 33. Weevil. Xataral size. Fig. 34. —Weevil. Magnified 12 diameters. Ephestia. — The larva of the moth, which feeds on cocoa (Ephestia elu- tella), has sometimes caused great ravages in flour and in biscuits. At Cork and Gibraltar many tons of biscuit have been rendered useless by this larva, which appears to have been inti-oduced from the cocoa stored for the fleet.' Adulterations of Wheat-Flour. At present there is very little adulteration of wheat-flour in this country, but with rising prices the case might be different. Abroad, adulteration is probably more common, and the medical officer must be prepared to in- vestigate the point. The chief adulterations are by the flour of other grains, viz. : — Barley, Eice, Buckwheat, Potato, Beans and peas, IMillet, in some ]VIaize, Linseed, countries, Oat, Melampvmni, Eye, Lohum, J and other grains noticed farther on. All these are easily recognized by the microscope. Other adulterations are by mineral substances, viz. : — Alum, Gypsum, Clay, Powdered flint. Calcium and magnesium carbonate. These are best detected by chemical examination. ' Professor Huxley has kindly given these interesting details. The larva of the Ephestia elutella (or ''' chocolate molh"' is small, and is never more than half an inch long. The female moths fly at night in swarms, and lay their eggs on the hiscuits or 250 PRACTICAL HYGIENE. Detection of Barley. — This is not easy, but can, with care, be often done. The envelopes of barley are the same in number as those of wheat, but they are more delicate. The outer coat has three layers of cells ; the walls of the external layer are beautifully waved, but not beaded ; the cells are smaller than those of the outer coat of wheat. The second coat disposed at right angles to the fu-st, as in wheat, is like the second coat of wheat, ex- cept in being more delicate and not beaded. The third is hyaline and transparent, as in wheat. The foiu-th has the cells similar in shape to the cor- responding wheat coat, but they are very much smaller, as may be seen on reference to the scale, and there are two, or often three, layers. -/^'^^^^N^'^^^^^S^^^^w The starch-qrain.^ of bai'lev are verv ^^/ aV W^><^^"-'H;.-e,-Nvi.??^^se==a.^ ]^Q the wheat, with a central hilum and obscure marking, but are on the whole smaller ; some have thick- ened edges, instead of the thin edges of the wheat-starch gi'ain, but it is very diflScult and sometimes impos- sible to distinguish them. It is therefore speciaDy to the envelopes that we must attend. Defection of Potato Starch. — This is a matter of no difficulty ; the starch-grains, instead of being round or oval, and with a central hilum and obscure rings, are pyriform, with an eccentric hilum placed at the smaller end, and with well-marked con- centric rings. Weak liquor potassai (1 drop of liq. pot. B.P. to 10 of water) swells them out greatly after a time, while wheat-starch is litlle affected by this strength ; if the strength is 1 to 3 (as in the figure), the swelling is very rapid. Detection of Maize {Indian Corn). — There are two envelopes ; the outer being made up of seven or eight strata of cells ; there is no transverse second coat, as in wheat ; the internal coat consists of a single stratum of cells like the fourth of wheat, but less regular in shape and size. The cellu- lose, through the seed holding the starch in its meshes, forms a very char- acteristic structure, which on section looks like a pavement made of triangular, square or polygonal pieces ; the cells are filled with the starch - Fig. 35. — Barley (loneitndinal section). Scale is the same as that of the Starch-grains. the puncheons which hold them. The larvas are soon hatched, and by means of strong jaws and active legs scrape and bore their way through crevices ; they eat the biscuit, and spoil more than they eat by spinning their webs over the biscuit. Cocoa stores swarm with the moths and larvae, and they even penetrated into many parts of H.M.S. Hercules. After examining into the ravages caused by these larvae in the biscuit at Gibraltar, Mr. Huxley made the following suggestions : 1. To have no cocoa stored in any place in which biscuits are manufactured. 2. To head up all biscuit puncheons as soon as they are full of the freshly baked biscuit. 3. Coat puncheons with tar after they are headed up, or at least work lime-wash well into all the joints and crevices. 4. Line the bread-rooms of ships with tin, so that if the Epheitia has got into a pun- cheon it maj' not get into the rest of the ship. 5. If other means fail, expose woodwork of puncheons to a heat of 200' Fahr. for two hours. QUALITY, CHOICE, AND COOKING OF FOOD. 251 grains, whicli are very small, and compressed, so as to have facets. They are very different from tlie smooth, uncompressed round cells of wheat. Fig. 36.— Outer Coat and Hairs of Barley (low power). FiG. 37.— Outer Coat of Barley (higher power). Bits of cellulose, with its peculiar angular markings, are always found if the wheat is adulterated with maize. Detection of Bean and Pea. — These adulterations are also at once dis- FiG 38.— Barley (second and third coats). covered ; the meshes of cellulose are very much larger than those of the fourth coat of wheat, with which it has sometimes been confounded, and 252 PifACTICAL HYGIENE. tlae starch-grains are also quite different ; they are oval or reniform, or with one eud slightly larger ; they have no clear hilum or rings, but many have a deep central longitudinal cleft ninning in the longer axis, and oc- cupying two-thirds or three-fourths of the length, but never reaching 00 TDTn; Fig. 39.— Barley (fourth coat) c «> .^©m^^- Fio. 40.— Barley (Starch-grains). completely to the end ; this cleft is sometimes a line, sometimes almost a chasm, and occasionally secondary clefts abut upon it at parts of its com-se ; sometimes, instead of a cleft, there is an irregular-shaped depression. If a little Uquor potassie be added, the cellulose is seen more clearly. Pea- FlG. 41.— Potato Starch x 285. See also Plate of Starches. Fig. 42. — Medium and small-sized Potato Starch-grains, treated with Liq. Pot. B.P. (strength 1 to 3), and x 285. flour is never added to a gi-eater extent than 4 per cent., as it makes the bread heavy and dark. If the flour be mixed with a little boihng water, the smell of the pea or bean is perceptible. Detection of Oa^.— There are two or three envelopes ; the outer longi- tudinal cells ; the second obliquely transverse, and not veiy clearl}' seen ; the cells are wanting in parts, or pass into the cells of the third coat ; the third a layer, usualh' single, of cells like wheat. The husk must be detached before the envelopes are looked for. The stai'ch-cells ai'e small, many- QUALITY, CHOICE, AND COOKING OF FOOD, 253 sided, and cohere into composite round bodies, which are very character- istic, and which can be broken down into the separate grains by pressiu-e. A high power is the best for this. The oat starch does not polarize light. There is no difficulty in the detection of the starch-grains. Detection of Pace. — The husk of rice is very peculiar ; on the outer coat are numerous siliceous gTanules, arranged in longitudinal and transverse /^r^^--- v\ XSrJO Pig. 43. — Indian-Corn Flour. See also Plate of Starches. Cellulose of Indian Corn, x 500, with marking's from the Starch-grains on the intercellular membrane. ridges (Figs. 49 and 50) (a). There are numerous hairs, some of which are seated over stomata. Below this is a membrane of transverse and longitudinal rough-edged fibres {b c), while below these again is a fine Fig. 44. — Longitudinal Section of Coats of Indian Corn and Cellulose, x 190. membrane of transverse angular cells (d), coveiing a very delicate mem- brane of large cells. The starch corpuscles are veiy small (Fig. 48) ; an- gular under low powers ; under high powers they are seen to be facetted 254 PRACTICAL HYGIENE. and compressed. They cannot be mistaken for the round cells of wheat, but may be confounded with oat starch, fi-om which, however, they are dis- tinguished by the absence of the compound cells or glomeruli. Their shape is also a little Hke maize, but they are very much smaller. Detection of Bye. — The envelopes are very like those of wheat, and can Fig. 4.5. — Bean Starch. perhaps hardly be distinguished from them. The recent starch-grains are also like those of wheat, but they are much more distinctly spherical. They have also sometimes a peculiar rayed hilum, which used to be thought -1 — I — I — ^ — ! — ) — \ — \ Fig. 46.— Pea Flour, peculiar to the older and drier grains. It is, however, to be seen even in the starch of fresh soft grains, whilst the plant is still gi-een. In the starch of wheat it is only met with occasionally, w^hen the grain is very old or dry. Rye, if in any quantity, is discovered by baking ; it makes a dark, acid bread. QUALITY, CHOICE, AND COOKING OF FOOD. 255 Linseed is not a common adulterant. The envelopes are peculiar : the external is made up of hexagonal cells, containing oil ; the second of round Fig. 47. — White Oat (long, sect., 2d and 3d coats not separable), a Compound grains, x 100. & One do., X 500. cells ; the third of fibres ; and the fourth of angular cells, containing a dark reddish coloring matter. <0 'C^'^^f^P *°^-'"- '^-s-, . ">r y«Jb>>i'-/7^;V>- Fig. 48.— Ground Rice Flour, x 350. Buckwheat (Polygonum Fagopyrum, or Fagopyrum esculentum). — Like rye, this is only likely to be found in wheat coming from the Baltic. The 256 PRACTICAL HYGIENE. di'awing siifficiently shows tlie texture of the envelopes, -which is very com- plicated. The starch-gi-ains are small and rovmd, and adhere together in masses. Under a high power there are indications of concentric lings. Bread made with this grain has a dai-kish, somewhat violet, color. ^^*'4'wy^ d ^ Fig. 49.— Rice, x 170. Fig. 50.— Rice, x 178. X 170. Fig. 49. Transverse Section of the Husk of Rice I Fig. 50. Appearance of Husk of Rice as seen in a transparent medium of glycerine and gum. C a. Siliceous granules, arranged in longitudinal and transverse ridges, perforated by openings — stomata. some having hairs seated over them, b c. Transverse and longitudinal, brittle, rough-edged fibres, d, A fine membrane of transverse angular cells ; these overlie a very delicate membrane of large cells, e. 31illet. — In India, Egypt, China, and West Coast of Africa, millet of some kind is likely to be an adulteration. Dr. Maddox's drawing (page 259) shows the beautiful structure of the envelopes, which could not be confounded M-ith those of wheat. The starch- grains are very small, round, and tolerably uni- form in size. 3Ielainpijrum arvense and other species (Pur- ple cow-wlieat — Scrophidariaceoe). — This has oc- casionally been mixed with flour ; it is not injurious, but gives the bread (not the flour") a peculiar smok}^ violet or bluish-\iolet tint. This depends on a coloring matter in the seed, which, when warmed with acid, gives the violet color.' Trifolium arvense (Trefoil — Leguminosce). — This also gives the bread a red-violet color. It is not known to be injurious. Rhinanthus major and crista galli {YeWow-raitle—Scrophulariaceis) gives bread a bluish-black color, a moist, sticky feel, and a disagreeable sweet Fig. 51. — Rye starch, with rayed hilum (after Hassall), x 420. > Pellischek, Schmidt's Jahrb., 1863, No. 3, p. 287. QUALITY, CHOICE, AXD COOKING OF FOOD. 257 taste. It is not injurious. Onohrychis saliva (Sainfoin — Leguminosce) has also been used. Pig. 52.— Eye— 1. Transverse Section of Testa, etc., xl08; 2. Coats in mtu from -without, xlTO. a, Ex- ternal ; 6, iliddle ; c, Internal coat ; li, Starch-grains x 108. Fig. 53.— Outer coat of Buckwheat, ap- Internal coats. The most internal is composed parently of irregular and interlacing of cells with an irregnlar waved ontUne, and fibrospirai cells, separable by boiling the longiradinal cells over the starch-cells, x ITO. testa and macerating it. Outside these cells is a very thin and delicate mem- brane, retaining the marks of attach- ment of the spiral cells, x 170. Lolium temulentum (Darnel — Gramineoe ; otlier species maybe used). Vol. I.-17 258 PRACTICAL HYGIENE. — This gives the bread no color, but produces narcotic symptoms, vertigo, hallucinations, delirium, convulsions, and paralysis.' Pellischek states that these symptoms do not occur if the grain be dried in an oven before Fig. 54. — Buckwheat — transverse section of outer, middle, and internal coats, with I x 170. cellulose containing starch-grains f Starch-grains x 500. baking, or if the bread is left for some days before being used. The detection of the lolium is best effected by means of alcohol, vv^hich gives a greenish solution with a disagreeable, repulsive taste, and on evaporation ' The peculiar symptoms produced by Lolium temulentum, or bearded Darnel, were well known to the ancients. Pereira states that the first symptoms are gastro-intestinal, snch as vomiting and colic, and then cerebro-spinal symptoms come on, viz., headache, giddiness, tinnitus, confusion of sight, dilated pupils, delirium, trembling and paralysis (Elements of Materia Medica, 1850, vol. ii., p. 977). The same effects are produced on animals. Pereira states that he did not succed in obtaining the chemical test noted in the text, viz., the green alcoholic solution and the yellow resin on evaporation. Hassall figures the starch-grains of the lolium as small and something like rice ; fifty or sixty may adhere together and form a compound grain not very unlike the oat. The envelopes are tolerably distinctive ; the cells of the outer coat are made up of a single layer, and are disposed transversely instead of longitudinally. The second coat is in two layers, and the cells have a vertical arrangement. The third coat is like the inner coat of wheat. This account is taken from Hassall. It is not very likely that any other grains except those mentioned in the text will be mixed with wheat flour. The seeds of the Peruvian food, the Chenopodium Quinoa have not apparently been used as a falsification. The starcli-grain of the Quinoa are said to be the smallest known. It may be worth remarking that this seed is very rich in salts (2.4 per cent.), and particularly so in iron (.75 per cent.) ; indeed, it is the rich- est in iron of any vegetable. It is possible that it might be a useful food in some cases of illness. It is fairly nutritious and digestible. The starch-grains of the acorn, which might perhaps be added in times of great scarcity, would be immediately detected, as they have a very characteristic central depression, and are also quite different in shape from the flat, round, smooth starch- cells of the wheat and barley. QUALITY, CHOICE, AND COOKING OF FOOD, 259 a resinous yellow-green disagreeable extract is left. Pure flour gives with alcohol only a clean straw-colored solution, with an agreeable taste (PeUischek). Bromus or Sei^rafalcus (Brome-grass — Graminece ; different species— Arvensiii or Secalinus). — PeUischek states that the seeds of this plant give the bread a dark color, and make it indigestible. It is probably a most uncommon adulteration. Fig. 55. — Millet Seed — a, Transverse Section of Testa Coats, seen from inside, a, Outer; 6, Middle; c, Inner coat x 170 ; S, Starch-grains x 5UU. Scale l-lOOOth inch. It will be found that, when mixed with floirr, the microscope wiU de- tect readily many of these substances. Detection is often very difficult when the flour is made into bread, and therefore, whenever from the bread there is any cause of suspicion, means should be taken to obtain some of the flour. Co7ies Flour. — A flour obtained from Eevel wheat is used by bakers for dusting their troughs. Hassall has found this Cone's flour to be greatly adulterated with rice,' maize, beans, rye, and barley. Sometimes Cones flour is mixed with good flour. Cooking of Flour. The effect of heat is to coagulate the albumen, and to transform some of the starch into dextrin. Substances are also added to the bread to cause a further transformation of the starch. Cakes. — The unfermented cakes '^ are simjjly made with water and salt. As they are very readily made, are agreeable to taste, and nutritious, it is very desirable to teach every soldier to make them ; so that in war, when bread is not procurable, he may not be confined altogether to biscuit. The Australian " damper" is simply made by digging a hole in the ground, fill- ing it with a wood fire, and, when the fire has thoroughly burnt up, re- ^ Several samples I have examined contained nothing but rice, sold as " Rice Cones." — (P de C. ) ' The Chupatty of India. This is sometimes 260 PEACTICAL HYGIENE. moA-ing it, placing the dough on a large stone, covering it with a tin j^late, and heaping the hot ashes round and over it. In a campaign, even* sol- dier, if he could get Hour and wood, would soon learn to bake a cake for himself. The only point of manipulation which requires practice is not to have the heat too great ; if it be above 212° too much of the starch is changed into dextrin, and the cake is tough. Exposed to greater heat, and well dried, the unfermented cakes become biscuit. Macaroni is flour from a hard Italian grain, moistened with water, and pressed through a number of small openings, while at the same time heat is applied. As it is very nutritious in small bulk, and keeps well, it would be a good food for soldiers in war if its cost could be lessened. Sub-Section III. — Biscuit. To make biscuit, flour is often taken with little or no bran (on account of the hygroscopic jDroperties of bran) ; but bran is also sometimes used : no salt is added. The simplest biscuits are merely flour and water. Some biscuits are made with milk, eggs, etc. Choice of Biiicuit. — Biscuit should be well baked, but not burnt ; of a light yellow color, and should float and partially dissolve in water ; when struck,' it should give a ringing sound ; and a piece put into the mouth should thoroughly soften down. It should be free from weevils, which are easily seen. Advantages as a Diet. — As it contains little water, and, bulk for bulk, is more nutritious than bread, three-fourths of a pound are usually taken to equal 1 lb of bread. Its bulk is small, and it is easily transported. Disadvantages. — Like flour, it is deficient in fat. After a time, it seems difficult of digestion. Perhaps the want of variety is objectionable ; but certain it is, that men do not thrive well upon it for long periods. In war, it has always been a rule with the best English army surgeons, for more than a century, to issue bread as much as possible, and to use biscuit only in cases where it cannot be avoided. Sub-Section IV. — Bread. If carbon dioxide gas is any way formed in or forced into the interior of dough, so as to divide the dough into a number of little cavities, bread is made. There are three kinds of bread : 1. Carbon dioxide is disengaged by a fermentative process, caused by yeast or leaven. Dui-ing the baking a certain amount of performed sugar yields CO^ ; a portion of starch is converted into dextrin and sugar, and also yields C0„ ; a little lactic and butp-ic acids, and extractive matters are formed. It is of importance to prevent this change from going too far ; and herein is one of the arts of the baker ; and it is partly to prevent this that alum is added, which has the property of arresting the change. In making bread, the proportions are 20 ft of flour ; 8 to 12 ft of tepid water ; 4 oz. of yeast, to which a little potato is added, and 1^ to 2 oz. of salt ; 280 ft of flour (1 sack) will give from 90 to 105 4-ft loaves ; or 100 ft of flour will make from 129 to 150 ft of bread. If there is 14 per cent, of water in the flour, the bread will contain in the former case 33.1 per cent., and in the latter, 42.7 per cent. If 100 ft of flour contain 14 j)er cent, of water, and make 141^ ft of bread, the bread will contain 40 per cent, of water ; the baker always endeavors to combine as much water as he can QUALITY, CHOICE, AND COOKING OF FOOD. 261 SO as to get more loaves. 6^ ft of dougli yield 6 ft of bread. Machines are now generally used for mixing the dough (Stevens' Machine). 2. CO^ is disengaged by mixing sodium or ammonium caa-bonate with the dough, and adding hydi-ochloric, tartaric, phosphoric, or citric acids. Baking powders ai-e compounds of these substances. 3. CO^ is forced thi-ough the dough by pressure (Daughsh's patent aerated bread). This process has the great advantage of rendering it im- possible that the conversion of starch into dextrin, sugar, and lactic acid shall go too far. About 20 cubic feet of C0„ (derived from chalk and sul- phuric acid) are used, for 280 ft of flour ; and about 11 cubic feet ai'e actually incoi-porated with the flour (OdHng). Advantages of Bread as an Article of Diet. . It is hardly necessary to mention these. The great amount of nitro- genous matters and starch it shares with flour ; the nitrogen is to the car- bon as 1 to 21. It thei'efore requires more nitrogen for a perfect food. The process of baking renders it more digestible than flour. Xo satiety attends its use, although it may be always made in the same way ; this is probably owing to the great variety of its components. Disadvantages. — It is poor in fat and some salts, especially in the case of the finest floui' freed from the internal envelope. Therefore we see that the practice of using fat with it (butter for the rich, fat bacon for the poor man) is extremely common. As to the relative advantages of the three methods of making bread, the last (aeration by C0„) is said to have the advantage of making white bread, though the inner envelopes are left ; of not causing any loss of starch, or permitting the change to go too far ; of not containing any unwholesome yeast. The systen of making bread with yeast has been objected to on the ground that bad yeast is often used ; the fermentative changes go on in the stomach, much C0„ is disengaged, and dyspepsia, flatulence, and unpleasant sensations, such as heart-bum, are produced. There is no doubt that badly prepared bread gives rise to these symptoms, though that this is owing to bad yeast is at least uncer- tain. The second method yields a wholesome bread, but is too expensive for common use, and it has also been pointed out that the hydrochloric acid of commerce always contains arsenic. The amount would be too small to be hurtful, but might be of medico-legal consequence. Special Points aboid Making of Bread. Bread may be of bad color — rather yellowish, from old flour ; from grown flotu' (in which case the changes in the starch have generally gone on to a considerable extent, and the bread contains more sugar than usual, and does not rise well), and perhaps fi'om bad yeast. The color given by admixture of bran must not be confounded with yellowness of this kind. Bread is also dark colored from admixture of other grains, as already noticed under flour (rye, buckwheat, melampjr-um, sainfoin, etc.). Bread may be acid, from bad flour giving rise to an excess of lactic and perhaps acetic acids, or, it is said, from bad yeast. In finding the cause of acidity in bread, look first to the floui', which may be old, and a little discolored, a id too acid ; if nothing can be made out, examine the yeast, and change_ the source of supply ; then look to the vessels in which the dough is kneaded, and to the water. Enforce great cleanhness on the part of the men who make up the dough. In India bread becomes sour fi'om bad 262 PRACTICAL HYGIENE. cleaning of the flour. Dr. Godwin, A.M.D.,' states that at Bareilly the wheat was imj^erfectly gi-ound in small hand-mills ; it was then separated by shifting into four portions, viz., bran ; " attar," which corresponds to pollards; " soojie," which consists of gluten and starch; and "maida," which is nearly all starch. The soojie, from imperfect gi-inding, is granu- lated, and chiefly used for bread, a small portion only of maida being mixed with it. To cleanse the wheat before grinding it, it was washed and then dried in heaps in the sun ; this caused fermentation and a rajoid development of acidity. The heaps of corn were quite hot to the feel. A very acid bread was given, but when the wheat was not thus washed it yielded a good bread. Bread is heavy and sodden fi-om bad yeast fermenting too rapidlj^, or when the fermentation has not taken place (cold weather, bad water, or some other cause, will sometimes hinder it), or when the wheat is grown ; when too little or too much heat has been employed. It is said also, that if the flour has been dried at too great a heat (above 200° Fahr.), the gluten is altered, and the bread does not rise well. It is bitter from bitter yeast. It becomes mouldy rapidly when it contains an excess of water. Eice is used as an addition because it is cheaper ; it retains water, and therefore the bread is heavier. Kice bread (if 25 per cent, of rice be added) is heavier, of closer texture, and less filled with cavities. Potatoes are sometimes added, but are generally used only in small quantity with the yeast. Alum is added to stop an excess of fermentation, when the altering gluten or cerealin acts too much on the starch, and it also whitens the bread ; it does not increase the amount of water ; it enables bread to be made from flour which otherwise could not be used. Sulphates of copj^er and of zinc, in very small amoimt, are sometimes employed for the same purpose. For acid flour, hme-water is used instead of pure water ; lime-water has this advantage that, while it does not check the fermentation of yeast, it hinders the action of diastase on starch. It must be caustic lime-water, and not chalk and water, as sometimes is the case. Loaves are generally weighed when hot, and that is considered to be their weight. In the Austrian army, a loss of 2.9 per cent, in four days is permitted. After being taken from the oven bread begins to lose weight.^ The loss of weight depends upon size, amount of crust, temperatm-e, and movement of air. In a sheltered place, at ordinary temperature, a 2-ft) loaf, baked with crust all over, loses about f per cent, in coohng, and from 1 to 1:^ in five hours. A similar loaf, with only top and bottom crust, loses 3 per cent, in coohng, and about 4 per cent, in five or six hours. A loaf with four sides cmst loses 2 per cent, in cooling, and retains its weight without much further loss for five hours. For each of six sides that is not crust there is a loss of weight of about 1 per cent, in the first five hours. At the end of twenty-four hours the proportion is about one-half more, and the total loss is doubled at the end of seventy-two hours (three days). If the bread is baked in larger loaves (4 ft), for instance) the loss will be ' Army Medical Report, vol. vii., p. 451. * See Report on Hygiene, Army Medical Reports, vol. xviii., p. 219. QUALITY, CHOICE, AISTD COOKING OF FOOD. 263 proportionately less, the ratio of tlie evaporating surface to the bulk of the loaf being diminished. When loaves become stale they can be dipped in water and rebaked, and then taste quite fresh for twenty-four hours ; after that they rapidly change. Old biscuit also, soaked in water, can be rebaked, and becomes palat- able. In the French army different kinds of bread are used :' ordinary bread ; biscuited bread ; bread half biscuited ; bread one quarter biscuited ; hos- pital bread. The " Paia biscuite " is used only on service ; it is baked more firmly than ordinary bread. Pain de munition ordinaire keeps 5 days in summer and 8 in winter. '* au quart biscuite " 10 to 15 days. " demi " " 20 to 30 " " biscuite " 40 to 50 " The French munition loaf weighs 1.5 kilogrammes (3.3 lb avoir.), and contains two rations of 760 grammes (each 1.65 lb). The ration of biscuit is 550 grammes (1.2 lb). It would be useful to adopt the practice of strongly baked bread in our army ; it is a good substitute for biscuit. Examination of Bread. There is, perhaps, no article on which the medical officer is more often called to give an opinion. General Characters. — There should be a due proportion, not less than 80 per cent, of crust ; the external surface should be well baked, not burnt ; the crumb should be permeated with small regular cavities ; no parts should be heavy, and without these little cells ; the partitions between the cavities should not be tough ; the color should be white or brownish from admix- ture of bran ; the taste not acid, even when held in the mouth. If the bread is acid the flour is bad, or leaven has been used ; if the color changes soon, a.n(\. fungi form, the bread is too moist ; if sodden and heavy, the flour is bad, or the baking is in fault ; the heat may have been too gxeat, or the sponge badly set. Chemical Examination. — This is conducted chiefly to ascertain the amount of water and acidity, and the presence of alum or sulphate of copper. Water. —Take a weighed quantity (say 10 grammes) of criuub, and dry in a water bath ; powder, and then dry again in a hot-air bath or oven, and weigh ; the water should not be more than 45 per cent. ; if more, the bread is pro tanto less nutritious, and is liable to become sooner mouldy. Acidity. — This can be determined by a standard alkaline solution.^ In two samples of fresh good bread examined at Netley, the percentages of acidity (reckoned as glacial acetic) were respectively 0.054 and 0.055 (3.78 and 3.85 grains per lb) ; in a sample rather underbaked, but fairly good, 0.072 per cent. (5.04 grains per ft) ; and in three samples, condemned as inferior, 0.085, 0.088, and 0.104 per cent, respectively (5.95, 6.16, and 7.28 grains per ft).' On another occasion, two samples of fairly good bread yielded 0.102 and 0.12 per cent. (7.14 and 8.4 per ft respectively) ; and ^ Code des Officiers de Sante, 1863. ] See Appendix A, Vol. II. ' Report on Hygiene, Armj Medical Reports, vol. xviii., p. 222. 264 PRACTICAL HYGIENE. two others, from bakers in the neighborhood, 0,084 and 0.000 (5.88 and 6.30 i^er ib respectively). A sample condemned as som- yielded 0.18 (12 G per til) ; 8 grains per lib (0.114 per cent.) ought certainly to be the limit. Alum. — The determination of the presence of alum is not difficult, but the quantitative analysis is necessary, since it has been shoAvn by Wanklyu that unalumed bread may contain an appreciable amount. Many processes have been proposed," some of which are merely modifications of each other. The process described in the foot note seems the most simple.' Wanklyn considers that unalumed bi*ead may contain 5 or 6 milli- grammes of phosphate of aluminium in every 100 grammes of bread (= 0.005 per cent.). This is equal to about li grain of crystallized alum per lb of bread. It will be Avell to deduct this amount from the total amount of phosphate of aluminium found ; the remainder will represent the amount ' By Kuhlmann, Letheby, Odling, Wentwortli Scott, Crookes, Ilassall, Hadow, Horsley, Diipru, Wanklyn. • 1st part. — Take at least | fb of crumb, put it in a mortar, and soak it well in cold distilled water ; filter, and get as clear a fluid as possible ; add a few drops of hydro- chloric acid, and then chloride of barium If there is no precipitate no alum can have been added, and the process need not be proceeded with. If there is a slight precipi- tate, it may be accounted lor by sulphate of lime or magnesia in the water used in baking, or of sulphate of magnesia in the salt, or by the slight amount of sulphuric acid naturally existing in the grain, or added during the grinding. Perhaps the medi- cal officer will know whether the water or the salt contains sulphates, and if so, the absence of alum may be inferred. If there be a large precipitate, the presence of alum is probable, but is not certain, .and the process must be continued. 2d part. — Dupre's process, as modified by Wanklyn, seems on the whole the sim- plest and least liable to error, as it gets rid of one great source of fallacy, namely, the presence of alumina in the liquor potassae, which reagent is not required. The pro- cess is as follows: Take 100 grammes (= 3i ounces) of bread ; incinerate for four or five hours in a platinum dish to a gray ash ; weigh (tlie ash should not sensibly exceed 2 grammes); moisten with ;3 C.C. of pure hydrochloric acid to separate silica; add 20 to 30 C.C. of distilled water, boil, filter, wash the filter well with boiling water ; add to the filtrate, which contains the phospliates of calcium, magnesium, aluminium, and iron, 5 C.C. of liquor ammonire (sp. gr. 880), which causes a precipitate of these phos- phates ; then add gradually 20 C.C. of strong acetic acid, which partially clears the fluid by dissolving the phosphates of calcium and magnesium ; boil and filter. The undissolved part is a mixture of phosphate of aluminium and phosphate of iron ; wash, precipitate well with boiling water, dry, ignite, and weigh. The iron must now be determined in this precipitate. This may be done by the permanganate, but Wanklyn's colorimetric test is probably better : it is as follows : Dissolve 1 gramme of pure iron wire in nitro-hydrochloric acid, precipitate the ferric oxide with ammonia ; wash the precipitate, dissolve it in a little hydrochloric acid, and dilute to 1 litre: one C.C. therefore equals 1 milligramme of metallic iron ; when used it is diluted 1 in 100 so as to make a solution, of which each C.C. contains jliith milligramme (= 0.01 of a milligramme) of metallic iron. To use this, dissolve the phosphates of aluminium and iron (obtained by the above described process; in pure hydrochloric acid, and dilute to 100 C.C. Test the .solution to see if it give a deep color with ferrocyanide of potassium ; if the color is not too deep take 50 C.C. of the solution, but if it be deep take a smaller quantity, and make it up to 50 C.C. with dis- tilled water, taking care that it is well acidulated. Put it into a cylindrical glass, and add 1 or2 C.C. of solution of ferrocyande of potassium: a blue color is given. Into another glass 1 C.C. of strong hydrochloric acid is put, and 50 C.C. of distilled water; 1 or 3 C.C. of ferrocyanide are added; the standard solution of iron is then dropped in till an equal color is produced. The amount of iron is then read off and calculated as phosphate (1 of iron = 2.696 FePOi). Deduct the weight from the total weight of phosphate of aluminium and iron ; the remainder is phosphate of aluminium {= Al POj), of which 1 part equals 0.42 alumina, or 2.1 dry or 8.9 crystallized potas.sium alum ; or 1.9 dry or 3.7 of crystallized ammonium alum, which last is almost the only kind now in the market. Winter-Elyth (Analyst, vol. vii., 1882, p. 19) proposes to dissolve out the added alumina by long digesting in a large bulk of 5 per cent, hydrochloric acid. Should this succeed it will simplify the operation. QUALITY, CHOICE, A:N"D COOKIXG OF FOOD. 265 eorrespondmg to alum added. Carter Bell ' deducts 10 grains per 4-ib loaf, or 2-k grains per ft), before reckoning adulteration. Dr. Lethebj also used a decoction of logwood as a test ; a piece of pure bread and a piece of suspected bread are put into a glass containing fi-eshly prepared decoction, and left for twenty-four hoiu'S ; the pui'e bread is simply stained, the alumed bread is dark pm-pHsh, as the alum acts hke a mordant. Mr. Hadow and I\Ir. Horsley " have also used this test with advan- tage, but 'Mr. Crooks, after many experiments, came to the conclusion that it was valueless.^ Winter-Blyth proposes the use of slips of gelatine soaked in the aqueous solution of the suspected bread. If the bread is pure the gelatine is stained only a reddish-brown by logwood, and can be decolor- ized by glycerine ; alumed bread gives a more or less deejD blue color, which is permanent in glycerine. Alum is not much used except with inferior breach^ The amount of alum in bread is said to be, on an average, 3 ounces to a sack or 280 lb of flour ; if the sack gives 105 -i-ft loaves, there T\ill be 3 gi-ains in a lb of bread ; but if crystallized alum is meant by this, there will only be about 1^ grain of diy alum. HassaU states the C|uantity to be ^ ft) (8 ounces) to 240 ft) of flour, but that the c|uantity diflers for old and new flour. A very good witness,^ in the inquiry into the gTievances of the journeymen bakers, gave the c[uantity at 10 ounces per sack ; this would give 41.6 grains per 4-ft) loaf, or 10.4 grains per ft). T\Tien mixed with flour and baked, the alum is decomposed, part of the alumina combines most strongly with phosphoric acid ; and either this or the alum itself is presumed to be in combination with the gluten ; potassium disulphate is probably formed. Gupric Sulphate. — Cut a smooth shce of bread, and draw over it a glass rod dipj)ed in potassium ferrocyanide. If copper be present, a brick-red color is given by the formation of fen'ocyanide of copj^er. The test is very dehcate. It is beheved to be a very rare adulteration in England. It has been said that cobalt is used instead of cojiper, but it is also probably very rare ; it can be detected by the blueness of the ash.^ Potatoes. — If potatoes in any c[uantity have been added, the ash of the bread, instead of being neutral, is alkahne ; this can only occur from sodium carbonate having been added, or fi'om the presence of some salts of organic acids, citrates, lactates, tartrates, which form carbonates on incineration. But if it be from sodium carbonate, the solution of bread will be alkaline, so that it can be known if the alkalinity is produced during incineration. If so, it is almost certain to be fi'om potato. Examination of YeaM. — Common brewers' yeast is not likely to be adulterated. If any solid mineral substances are mixed with German yeast, they are detected either by washing or by incineration. Dr. Letheby found German yeast, imported in 1863, to be adulterated with 30 per cent, of pipe-clay. ' Analyst, Xo. 40, 1879, p. 126. ^ Chemical Xews, May, lbT2. ''Ibid. , September, 1862. * Eeport on Journeymen Bakers, 1862, p. 164; see also Odling's Papers. Hassall, however, found alum in half the loaves examined. A writer in the Lancet (January, 1872) states that at that date alum was found in 10 out of 20 loaves, and the amount was from 12 to 96 grains in the 4-lb loaf. ° Report on Journeymen Bakers, 1862. p. 163. Some of the statements are beyond even this amount — 1 lb to 4 lb per 1,000 (4-lb ?) loaves (p. xxxvi.) ; but this is probably an exaggeration. ^ Dr. Campbell Brown. 2G6 PRACTICAL nTGIET^. Microscopical Examination of Bread. This is of Ten' little use as far as adtilteration is concerned, but the presence oi fungi can be detected. The most common fungus is a kind of Penicillium (sitophilum and roseum), which gives a greenish, bi'owTiish, or reddish-yellow color ; sporules, sporangia, and mycelium can all be seen. The Oidium aurantiacum has been several times detected in France and Algeria ; it is distinguished by its orange-red color. A greenish mucor is often found in bread. Fuccinia, so common in flour, has not been detected. Diseases connected with the Qualify of Flour and Bread. 1. The Flour originally bad. — It may be ergoted, or grown and ferment- ing, or with/; • ( Dhurra (Arabic). ( oorqhum or Fanicum \ ^,, , )m ^\ ] f J . i Cholam (Tamul). ^ -^ '' (Joaror Jowree (Hind.). Fanicum miliaceum, Pencillaria spicata. Golden-colored millet, Sorghum saccharatum. J Biijra or Bajree (Hind.). I Cum^ Jumboo (Tamul;. Italian millet, German millet, Setaria Italica, Setaria Germanica. Eleusine corocana, \ Kala kangnT (Hind.). ( Tenay (Tamul). < Eaggee or Eaggy (Hind., \ Cauarese, and Tamul). y Murha and !Maud in the ' X. Px'o v. of Hindustan.'' The millets are xery similar in composition (as given in the table, p. 212). The ash is rich in sihca and j^hosphates. ' The larger grains — especially the American kinds— have often much less flavor than the smaller and less attractive Indian kinds. ■' The native names of the Indian grains and pulses used, especially in Southern India, are given very fully in a paper by Mr. Elliot (Edinburgh Philosophical Journal, July, 1S62); and also in Mr. Cornish's excellent paper (Madras Medical Journal, Feb- ruary, 1864). QUALITY, CHOICE, AIS^D COOKING OF FOOD. 271 j\Iillet bread is very good, and some was issued to the troops in the last •China Expedition. This should always be done in a millet country, if ■wheat or barley cannot be got. In Northern China millet is almost exclu- sively used. Eaggy or Eagee, Murha and Maud of the ujDper provinces [Eleusine corocana), is largely used in Southern India (Mysore), and in some parts of Northern Hindustan, and is considered even more nutritive than wheat. It is veiy indestructible, and can be presei'ved for many years (even sixty) in dry gTain pits. Buckwheat is not so likely to be used. It is poor in nitrogenous sub- stances and fat, but makes a fair tasting bread. SECTION ATH. LEGUMIXOS.E. The Leguminosce, in respect of dietetic properties, are broadly distin- guished from other vegetables by their very large amoimt of nitrogenous substance, caUed legumin or vegetable casein ; there are, in addition, a httle albumen and other protein bodies. The advantages of peas and beans as articles of diet are the gTeat amount of legumin, and the existence of much sulphur and phosphorus in combination with the legumin ; in salts also they are a httle richer than the (Jerealia, especiaUy in potash and lime, but ai'e rather poorer in phosphoric acid and magnesia ; 1 tb of j^eas contains about 168 grains of salts. The disadvantage of peas and beans is a certain amount of indigestibihty ; about 6.5 per cent, of the ingested pea passes out unchanged, and starch-cells, giving a blue reaction with iodine, are found in the fseces ; much flatus is also produced by the hydrogen suljDhide formed from the legumin. Still, they are a most valuable article of food, and always ought to be used when much exercise is taken, as they are an excellent addition to meat and Cerealia. Both men and beasts can be nourished on them alone for some time. Added to rice, they form the staple food of lai'ge populations in India. !Mi\ Cornish mentions that, in the Sepoy Corps, the men ai'e much subject to diarrhoea from the too great use of the "dhoU" (Caja/ius indicuf). Gram [Cicer aHetinum), al- though chiefly used for horses and cattle, is sometimes employed as food for men in India ; it makes palatable and nutritious cakes. Choice of Pea. — By keeping, peas lose their color, become veiy pale and much shrivelled, and extremely hard. Anything like decomposition, or existence of insects, is at once detected. The powder does not keep very long ; the whole peas should be split. The microscope should be used to detect Acarus. Cooking of Peas and Beans. — They must be boiled slowly, and for a long time, otherwise they are very indigestible. If old, no amount of boiling softens them ; in fact, the longer they are boiled the harder they become ; they shoiild then be soaked in cold water for twenty-four houi-s, cnished, and stewed ; in this way even veiy old peas may be made digestible and palatable. Chalk-water must be avoided in the case of peas as of other vegetables, as the lime-salts form insoluble compounds with the legiomin. Lathy rus sa^iuus (Kassaree-dhoU of India). — Occasionally in Europe, and constantly in some parts of India, this vetch has been used when mixed with wheat or barley flour for bread. "V^Tien used in too great quantities, it produces (without there being necessarily any alteration of the gTain ?) constipation, cohc, and some form of indigestion, and if eaten in large quantity, paraplegia. It is also injurious to horses, but less so to oxen. 272 PRACTICAL HYGIENE. In Bengal, Dr. Irvine ' found in some villages no less than from 10 to 15 per cent, of the people paralji^ic from this cause. From its composition, it would not ajjpear to be innutritions. SECTION IX. STARCHES* AND SUGAR. Sub-Section L — Aerowkoots. 3Iaranta Arroioroot (West Indian). — The chief kind is obtained from Maranta arundinacea. The quality of Maranta arrowroot is judged of by its wLiteness ; by the grains being aggregated into little lumps, and by the jelly being readily made, and being firm, colorless, transj^arent, and good tasted. The jelly remains firm for three or four days witJiout turaing thin or sour, Avhereas potato lloiu' jelly in twelve hours becomes thin and ace- scent. Under tlie microscope, the starch-gi-ains are easily identified. They are slightly ovoid, like potato starch, but have a mark or hne at the larger end (the hilum of the potato starch is at the smaller end), the con- centric Hnes are well marked. The most common adulterations are sago, tapioca, and potato starch. All these starch-grains are readily detected by the microscope. Curcuma Arrowroot. — AiTowroot obtained ft'om Curcuma has the same physical characters as Maranta, but under the microscope the starch-grains are large and oblong, marked with very distinct concentric lines, which, however, are not entire cu'cles, having an indistinct hilum at the smaller end. Manihot Arrowroot. — This comes from Rio, and is obtained from Jatropha manihot. The starch-grains are very marked." Tacca or Otaheiti Arrowroot. — Hassall gives a figure which shows that the starch-grains resemble those of Manihot. Arum Arroicroot. — The Ai-um or Portland aiTOwroot has small, angu- lar, and facetted starch-grains, which cannot be confounded with any of the former. They are a little hke maize. This is sometimes called Port- land Sago. British or Potato Arrowroot. — Under the term "Farina," potato starch is sold in the market ; so white and crackling, and making so good a jelly, that it is not always easy to distinguish it from 3Ianihot. The micro- scope at once detects it. The peax'-shaped gi-ains, marked hilum toward tlie smaller end, and the swelling with weak liquor potass?e, render a mis- take impossible. In making the jelly a much larger cpiantity is required than of Mai'anta arro-oToot. Maranta arundinacea, mixed with twice its weight of hydrochloric acid, produces a white oj^aque paste, whereas po- tato starch treated similarly produces a transparent acid jelly-like paste. Canna or Tous-les-Mois Arrowroot, obtained from Canna edulii<, N.O. Marantacece. — The starch-grains are like those of the potato, but much larger, and the concentric Unes are beautifully marked and distinct.' Sub-Section II. — Tapioca. This is obtained from the finest part of the pith of Jatropha manihot or Ca.Hsava. Under the microscope the starch-gi-ains are small, with a central hilum ; and sometimes three or four adhere together and form compound grains. ' Indian Annals, 18.57. Ibid., January, 1808, p. 89, Dr. Irvine notices the resem- blance of the symptoms to the Barbiers of Bontius. ^ See table, p. 273, and plate of drawings by Dr. Maddox farther on. QUALITY, CHOICE, AND COOKHSTG OF FOOD. 273 It is adulterated with sago and potato starch, both of which are easily detected by the microscope. Sub-Section HE. — Sago. The best kinds are derived fx'om the sago palm {Sagus fariyxifera), but the sago of the Gycas circinalis is also sold ; it is, however, inferior. Granulated sago is either "common" or "pearl;" the latter is chiefly used in hospitals. The starch is soluble in cold as well as in hot water. The starch-grains are elongated, rounded at the larger end, and com- pressed at the other ; and hence their shape is quite different from the potato starch. The hilum is a point, or more often a cross, slit, or star, and is seated at the smaller end ; whereas, as in Maranta arrowroot, the hilum is at the larger end. Rings are more or less clearly seen. In the market is a iictitious sago made of potato flour. This is some- times colored red or brownish, either from cochineal or sugar. In thirty specimens HassaU found five to be fictitious. The microscojoe easily de- tects potato starch. It is sometimes difficult to remember the characters of the different forms of starch, but it may be to a certain extent facilitated by a tabulated arrangement. The following table has been compiled by Dr. J. D. Mac- donald, R.N., F.R.S. Microscopical DiscHmination of the Principal Arrowroots and Starches. I. Starches with isolated smooth or unfacetted grains, being originally free in the cell cavity. General Characters. Particular Characters. Name. r Form. Hilum. ' Grains large. Hilum at the small end. A. — Contour ovoid. Hilum eccentric. B. — Contour oval. Grains me- dium sized. Hilum at the larger end. Hilum longitudinal. linear lateral. f Form. Outline even. Con- tinuous rings, ob- lique, including more than half the grain. Outline even. Con- tinuous rings, nearly transverse, including less than ^ half the grain. ' Outline uneven, often with beak- like projections. Hilum. Hilum distinct. f Hilum distinct. I I I Hilum indistinct. Hilum. slit-like, tri- radial or crucial Outline more even, beak less fre- quently seen. [ Whole grain still [ smoother and t_ more regular. f Grains often broad I and reniform. Grains narrower and [ more uniform. Hilum similar, but less apparent. Hilum similar, but still less marked. Potato ; British arrowroot. Tons - les - mois {Canna) ar- rowroot. Curcuma arrow- root. Bermuda {Mar- anta) arrow- root. St. Vincent ar- rovTTOot. C. — Contour ( round. "( Hilum. central. Vol. I.— 18 Form lenticular. [ Form spherical. j Hilum cleft-like, puckered, irregu- lar. Hilum less puckered and more regular. f Surface convex at I the hilum. Grains I large and minute 1 only. Surface depressed at the hilum. Grains large, medium- sized, and minute. Hilum often deeply fissured, star-like. Natal arrowroot. Bean starch. Pea starch. Wheat starch. Barley starch. Rye starch. 274 PRACTICAL HYGIENE. n. Starches with the grains facetted by original juxtaposition in the cell cavity. Hilum central. f Grains very large, with a central sinus or cavernous antrum. (Rings sinuous, irregular. ) (Hilum. often cavernous. in the cluster. r n • ^^ I Hilum stel- ^^^'^'^^ ^'^^^\ j 1 . -l (Like Tapioca without I Grains small. I, (Sago in miniature. ) B. — Altogether facetted. f Hilum late. Btel- Hilum incon- spicuous. preparation.) Grains small. (Discoidal with facetted margin. Grains minute. fin rounded glo- meruli or com- pound grains, J and free in the cells. Closely packed Rice, in the cells, and fixed. Tapioca. Rio arrowroot. Maize. Oats. Sub-Section IV. — Sugar. Choice and Examination. — The sugar should be more or less white, crystalline, not evidently moist to the touch, and should dissolve entirely in water, or leave merel}^ small fragments, which on examination with the microscope will be found to be bits of cane. The whiter the qualit;ji the less is the percentage of water, which varies in different kinds of sugar, from about .25 per cent, (in the finest sugar) to 9 or even 10 per cent, (in the coarser brown sugars). Most of the sugar now sold is very good and pure. The unpurified sugars contain albuminous matters which decompose, and a sort of fermentation occvu's. Acarus, or the sugar-mite, is usually found in such sugar, which is not known to be hurtful. Fungi also are very frequently present. Method of Examination. 1. Determine physical characters of color, amount of crystallization, etc. 2. Dissolve in cold water ; fragments of cane, starch, sand, gypsum, cal- cium phosphate are left behind ; test with iodine for starch. The best way is to dis.solve under the microscope, as all adulterations are then at once detected. 3. Determine percentage of water by drying thoroughly 10 grammes, and again weighing. 4. Excess of glucose (a little is always present) is detected by the large immediate action on the copper solution. QUALITY, CHOICE, AND COOKINa OF FOOD. 275 SECTION X. SUCCULENT VEGETABLES. Almost all other vegetables (except potatoes) are used, not so much on account of nutritive qualities, as for the supply of salts ; some of them, how- ever, contain very digestible starch and sugar, or other substances, such as pectin or asparagin, or pecuhar oils which act as condiments, as in onions. Sub-Section I. — Potatoes (Solanuvi tuberosum). The potato contains only a small amount of nitrogenous matter, and hardly any fat. Its ash is also poor in potash and phosphoric acid. But its starch is very digestible, and it contains a large quantity of vegetable acids and their salts (malates? tartrates? citrates), which form carbonates on incineration. The juice is acid, and there is no better anti-scorbutic. The acids are combined with potash, soda, and lime. As the amount of salts is small, and that of water large, at least 8 to 12 ounces of potatoes should be taken daily if no other vegetables are eaten (=8 ounces at 1 per cent, of salts contain 35 grains ; at 1.5 per cent. =52.5 grains). Choice. — Potatoes should be of good size, firm, cut with some resistance, and present no evidence of disease or fungi. A still better judgment may be formed by taking the specific gravity, and using the following tables : Multiply the specific gravity by the factor opposite it, and divide by 1,000 ; the result is the percentage of solids : — Specific gravity, between Factor. Specific gravity, between Facte 1061-1068 16 1105-1109 24 1069-1074 18 1110-1114 26 1075-1082 20 1115-1119 27 1083-1104 22 1120-1129 28 If the starch alone is to be determined, deduct 7 from the factor, and proceed as before, the result is the percentage of starch. If the specific gravity of the potato is — Below 1068, the quality is very bad. Between 1068-1082, " inferior. Between 1082-1105, " rather poor. Above 1105, " good. Above 1110, " best. As, however, the medical officer will seldom have an hydrometer ' which will give so high a specific gravity', and must work, therefore, with a common urinometer, the following plan must be adopted : — Take a sufficient quantity of water, and dissolve in it ^ an ounce or an ounce of salt, and take the specific gravity ; then add another ^ ounce or ounce, and take again the specific gravity ; do this two or three times, so as to get the in- crease of specific gravity for each addition of a known quantity of salt ; then add salt enough to bring the specific gravity to the desired amount. This is, of course, not quite accurate, but in the absence of proper instruments it is the only plan that seems feasible. Cooking of Potatoes. — The skins should not be taken off, or a large amount of salts passes into the water ; using salt water is a good plan, as ' Baum i's or Twaddell's hydrometers are the best for the purpose. 276 PRACTICAL HYGIENE. fewer of the salts then pass out. The boihng must be complete, as the starch-grams are otherwise undigested, and it must be slow, else the cellu- lose and albuminates are hard. Steaming potatoes is by far the best plan ; the heat must be moderate ; the steam penetrates everywhere, and there is no loss of salts. Preservation of Potatoes. — Sugar, in the form of molasses, is the best plan on a large scale ; a cask is filled with altei-nate strata of molasses and peeled and sliced jootatoes. On a small scale, boiling the potatoes for a few minutes wiU keep them for some time. Free exposure to air, turning the potatoes over and at once removing those that are bad, are useful plans. ' The preserved jjotatoes are sliced, dried, and granulated, and when well prepared, are extremely usefid. The Sweet Potato and the Yam are somewhat similar to the ordinary potato, and form good substitutes Avhen potatoes cannot be obtained. Sue-Section II. — Other Vegetables. The composition of CaiTots and Cabbage has been already given. The composition of the other kinds of vegetables is similar. Some vegetables contain special ingredients, such as asj^aragin in asparagus (a small amount is also contained in potatoes), wax, pectin, which is a little more oxidized than starch or sugar ; or pecuUar oils and savory or odoriferous matters. On account of its volatile oils, the onion tribe is lax'gely used, and is a capital condiment, and has an effect as an anti-scorbutic. It contains some citrate of calcium. There are many vegetables which can be employed as anti-scorbutics besides potatoes, onions, and green vegetables. The wild artichoke and Agave americana (cactus) are both excellent anti-scorbutics, and the latter is said to be better than Hme-juice. Sorrel, and in a less degree scurvy- grass and mustard and cress, are useful. In New Mexico, a salad made of the " lamb's quarter" {Chenojjodiuin album) has been found very useful.'^ In war almost any kind of vegetables may be used rather than that the troops should be left without such food. In one of the Caftre wars, an African corps kept free from scurvy by using a sort of grass (?) in their soup. The dried vegetables, and especially the dried potato, have consider- able anti-scorbutic powers (Armstrong).^ The dandelion was largely used in the French army in the Crimean war. The American Indians jDut up for winter quantities of dried plums, buffalo berries, and choke berries, and thus escape scurvy.^ If vegetables cannot be procured, citric acid, or citrate, tai'trate, and lactate of potassium should be given. These can be carried as lozenges. ' In the Crimean war there was a considerable loss of potatoes sent up to Balaklava, and at a time wlien the men were most in need of them. The addition of sugar to the raw potatoes might have been made. 2 Mil. Med. and Surg. Essays prepared for the U. S. Sanitary Com., 1864, p. 202. ^ Naval Hygiene, p. 112. In the American war, however, the anti scorbutic efi'ects of the dried vegetables were not foiand to be very great. I found that, in a sound raw potato, the amount of free and combined acid (reckoned as citric) was 0.4503 per cent. ; and that in the preserved potato used in the Arctic Expedition (187.5-76) it was 1.085 ; or in the ratio of 1 to 2.4. From this we find that 7 ounces of the preserved potato contained the equivalent of 3H grains of citric acid, or one ounce of navy lime-juice. The ration usually issued (2 to 4 ounces) is, therefore, too small, unless other anti- scorbutics be given. (See Report of Committee on Scurvy, Appendix, xiii., 365.)— [F. deC] * Hamilton's Mil. Surg., p. 212. QUALITY, CHOICE, AND COOKING OF FOOD. 277 SECTION XI. COW'S MILK. A cow gives very variable quantities of milk, according to food and race, and age of the calf ; perhaps 20 to 25 pints in twenty-four hours is the average for the j'ear, but with poor feeding it will fall much below this ; occasionally a cow, soon after calving, will give 50 pints, but this is not common. A goat will give 6 to 8 pints. Sub-Section I. — Milk as an Akticle or Diet. Milk contains all the four classes of aliment essential to health. Being intended especially for feeding during growth, the proportions of nitro- genous substances and fat, as compared to sugar, are large. For the average composition of good milk, see table, p. 212. In addition to casein, a small quantity of time albumen remains in so- lution after the casein has been thrown down ; and there is also, according to Millon,' another albuminoid substance, which he calls lactoprotein. In cow's milk the amount of albumen is said to be 5.25 grammes iper litre ; the amount of lactoprotein is much smaller, but has not been precisely determined.'^ The amount of salts varies from .5 to .8 per cent., but seldom, if ever, exceeds 1 per cent. The usual average is about 0.7 to 0.75. This is of importance in the detection of adulteration by salts. In poor milk the salts may be as low as .3 -per cent. Milk is very largely' used in some countries, especially in India and Tartary, where the use of the koumiss, prepared from mare's milk, has been supposed to prevent phthisis. This fermented drink is now also pre- pared from cow's milk, and largely used in this country. Milk varies in quantity and composition according to — 1st, the age of cow ; 2d, the number of pregnancies, less milk being given with the first calf (Hassall) ; 3d, to the age of the calf, being at first largely mixed with colostrum ; 4th, to the kind of feeding, beet and carrot augmenting the sugar ; ' 5th, and remarkably according to the race, some coavs giving more fat (as Alderneys), others more casein (as the long-horns). The last portion of the milk given in milking is richest in cream (Hassall). Wanklyn states that the proportion of solids is more stable, and never falls below 11.5 per cent. In Sweden, the milk of a herd of cows being analyzed daily for a year, the solids never fell to 11.5, and only 4 times to 12 per cent. (Wanklyn). The goat's milk is rather richer in solids (14.4 per cent. — Payen), and contains also a peculiar smelling acid (hircin or hircic acid). Specific gravity, 1032-1036. Ass's milk is rather poorer in solids (9.5 per cent. — Payen). This is owing to a small amount of casein and fat ; it is rich in lactin. The speci- fic gravity varies from 1023 to 1035. ' Comptes Rendus, t. lix , p. 396. ^ Commaille (Comptes Rendus, November 9, 1868) found creatinin in some putrid milk, derived, he tliinks, from creatin. He admits also, after Lefort, that there is a little urea. He found also some organic acids, the natxire of which is doubtful. ^ Some observations of Dr. Subbotin (Virchow's Archiv, Band xxxvi., p. 561) on the milk of bitches, show a marked effect by food ; the fat was much increased by meat ; the casein was less affected ; a large quantity of fat greatly lessened the secretion. 278 PEACTICAL HYGIENE. The buffalo milk is richer in all the ingredients. Taking the total solids of cow's milk at 13.2 per cent, (specific gravity 1030), one pint (20 ounces) will contain, in round numbers — Casein 350 grains. Fat 324 " Lactin 420 " Salts 66 " Total 1,160 or more than 2^ ounces avoir, of water-free food. To give 23 ounces of water-free food (or one day's allowance for an adult), about 9 pints of milk, of specific gravity 1030, are necessary. For an adult this would be far too much water, and the albuminates and fat would be in great excess. But for the rapid fonnation and elimination of the young, the water and fat are essential. It is a question whether, in old age, large quantities of milk might not be a remedy for failures in tissue formation and elimination.' Sub-Section II. — Axteeations of IVIilk. The cream rises in from four to eight hours ; it is hastened by adding warm water, but its quantity is not increased (Hassall). A new apparatus has been recently introduced by which the cream is obtained by agitation in a few minutes. Milk alters on standing ; it absorbs oxygen, and gives off C0„ ; placed in contact with a volume of air greater than its own bulk, it absorbs all the oxygen in three or four days (Hoppe-Seyler). The C0„ is formed at the expense of the organic matter (probalDly casein — HojDpe-Seyler), and bodies richer in carbon and hydrogen are formed ; fat increases in amount, and oxalic acid is said to be formed. Subsequently lactic acid is formed in large quantities from the lactin ; the milk becomes turbid, and finally casein is deposited. The cream which had preAdously risen to the surface disappeai'S. Milk given by Diseased Cows. Milk from diseased animals soon decomposes ; it may contain colos- trum, or heaps of gi'anules collected in roundish masses, pus-cells, or epi- thelium, and occasionally blood. It then soon becomes acid, and the microscope usuaDy detects abnormal cell-forms, and casts of the lacteal tubes. In cattle plague, it is said by Hvisson that the lactin lessens, while the nitrogenous matters are increased, and blood and aggregated granules are seen under the microscoi^e. In foot-and-mouth disease the specific gra\*ity rapidly falls (from 1030 to 1024), though this is not invariable ; there are gi-anular heaps under the microscope, and often blood or pus-cells ; Mr. M'Bride says pus can be found for a month after recovery. Bacteria and small ovid and round cells are common.'^ The milk sometimes coagulates on boiling. ' This was a point debated by Galen, so old is this suggestion. It is still undecided. Some old persons cannot digest milk. " Figures of the microscopical appearances are given in some very good papers on the subject in the British Medical Journal, October, 1869. QUALITY, CHOICE, AND COOKING OF FOOD. 279 Sub-Section m. — Examination of Milk. This is intended first to determine the quaUty. Put some of the milk in a long glass, which is graduated to 100 parts ; a 100 centimetre or Htre measure will do, or a glass may be specially prepared by simply marking with compasses 100 equal lines on a piece of papei', and gumming it on the glass. Allow it to stand for twenty-four houi's in a cupboard secured from currents of air. By this means the percentage of cream can be seen, and the presence of deposit, if any, observed. There should be no deposit till the milk decomposes ; if there be, it is probably chalk or starch. The cream should be from y^-Q-ths to ^y^^ths ; it is generally about jfoths; in the milk of Alderney cows it will reach y^^'^ths or -^^/yths. The time of year (as influencing pasture), and the breed, should be con- sidered. While this is going on, determine — 1. The Physical Characters. — Placed in a narrow glass, the milk should be quite opaque, of full white color, without deposit, without peculiar smell or taste. When boiled it should not change in appear- ance. 2. Reaction. — Reaction should be slightly acid or neutral, or very feebly alkaline ; if strongly alkaline, either the cow is diseased (?) or there is much colostrum, or sodium carbonate has been added. 3. Specific Gravity. — The specific gravity varies from 1026 to 1035, A very large quantity of cream lowers it, and after the cream is removed, the specific gravity may rise, under ordinary circumstances, about 2°.' The average specific gravity of unskimmed milk may be taken as 1030 at 60° Fahr., and the range is nearly 4° above and below the mean. It varies with temperature, so that in the tropics the medical officer will have to allow for this difi'erence. The following are the relative degrees of a milk that show^s 1030 at 60° Fahr., and 1031 at 39° Fahr. (maximum density- point of water) : — Temperature of Milk, 39° F. = 1031 " 60° F. =1030 " 70°F. = 1029 Temperature of Milk, 80° F. =1027.5 " 90° F. =1025.8 " 100° P. = 1024.0 The addition of water may be detected by the specific gravity. At 60° Fahr. there is a loss of 3° for every 10 per cent, of water added. No doubt the method is not perfect, but its ease of application strongly rec- ommends it. 4. Examine Chemically for the Amount of the Different Constituents. (a) Total solids. — Evaporate a known quantity to dryness in a flat and shallow dish, and weigh. Calculate the percentage. The heat must not ' Dr. Davies records a case where the specific gravity was 1024.6 ; there was 17 per cent, of cream, and the solids were 16.25. A case of this kind cannot mislead if the amount of cream is determined. Davies recommends that the specific gravity of the whey sliould be taken ; he says it is very constant between 1026 and 1028. In one sample I examined the specific gravity was 1020, and the cream -.^^rj the specific gravity of the skimmed milk was 1028.9. Another sample gave — specific grav- ity 1017.6, cream -,'^oHi ; specific gravity of skimmed milk, 1082.75. Another sample (which piirported to be the same as the last) gave a specific gravity of 1018.84, but the cream was only jinr ; in this case the greater part of the cream had been removed, and about 50 per cent, of water added. — (F. de C.) 280 PRACTICAL HYGIENE. exceed 212° Fahr. (100° C), and should be continued for at least three hours. There should be no charring. (b) A.-^ J^ y:J^ 3 I v^-- ^m %mi 3^^^#'" ''^'•- Jo 10 xr^.s-^ ^'^^i^wcrt^sa^^ 'iio *^ ■S> \iY'A iiYu ^i=?i5 f^ J^??^ ■•5>. %^ KJ' img p <> 1. Potato Starch. 2. Bermuda Arrowroot, 3. Tous les Mois. 4. St. Vincent Arrowroot. 5. Sago of Commerce. 6. Port Xatal Arrowroot. 7. Rio Arrowroot, 8. Tapioca. 9. Maize. QUALITY, CHOICE, AND COOKING OF FOOD. 293 granulated) are : "To three-quarters of a pound add about one quart of boiling water, stirring it at the same time ; cover it closely ; the basin or vessel used should be kept hot ; let it stand for ten minutes ; then well mash, adding butter, salt, etc., at discretion." It is stated to be equal to six times its bulk of the fresh vegetable, but this is hardly borne out by analysis ; four times is as high as it would be safe to allow. The analyses made by Professor Attfield and Dr. de Chaumont' show that a lb of preserved po- tato contains the sohd matter of only 3^ lb of ordinary fresh potatoes. Dried Vegetables [other than Potatoes). — Dried and compressed vege- tables of aU kinds (peas, caiihflowers, carrots, etc.) are now prepared, especially by Messrs. Masson & ChaUot, so perfectly that, if properly cooked, they furnish a dish almost equal to fresh vegetables. Professor Attfield found that dried compressed cabbage contained the solids of seven times its weight of fresh cabbage, whilst the mixed vegetables con- tained ^ue and a half iivneB the sohds of the fi-esh vegetables. They must be cooked very slowly. If there is any disagreeable taste from commen- cing putrefaction, which is very rare, a httle chloride of lime removes it at once. Potassium permanganate can be also used for this purpose. As anti-scorbutics they are said to be inferior to the fresh vegetable (experience of American war), but are still much better than nothing.^ Preserved Vegetables, that is, vegetables preserved in their natural con- dition (cooked), are much to be preferred, both as being more palatable and as being more nutritious and better anti-scorbutics. They occupy, however, much greater bulk. Dried Milk. — Preserved milk is sold in a liquid form, but is also sold as a powder, which is very well prepared. Concentrated Milk. — Milk is evaporated at low steam heat to the con- sistence of a thick syrup, and white sugar is added. After opening the tins the samples remain good for over a month. Dried Eggs. — The yolk is not easily kept after drying, but the white can be so ; it is cut into thin scales, and forty-four eggs make about 1 lb. The yolk and white are also mixed with flour, gTound rice, etc., and are then dried. ' Report of Committee on Scurvy, 1877. ' Professor Attfield (loc. cit.) considers that in the compressed vegetables some, at least, of the juice is lost in the preparation, probably by pressure. CHAPTEK VII. BEVERAGES AND CONDIMENTS. SECTION I. ALCOHOLIC BEVERAGES. Ajlthough it is convenient to place all the beverages whicli contain Al' cohol under one heading, they yet differ materially in composition and effects. Sub-Section I. — Beer. Composition. — The law formerly allowed only malt and hops to be used in brewing,' but sugar (under the name of saccharum) is now largely sub- stituted, as AveU as bitter substances other than hops. The specific graA-ity varies from 1006 to 1030, or even more, in the thick German beers ; the average in English beers and porters is from 1010 to 1011. The percentage of extract (dextrin, cellulose, sugar, lupu- lite, and hop resin) is from 4 to 15 per cent, in ale, and from 4 to 9 per cent, in porter. It is least in the bitter, and highest in the sweet ales. The alcohol varies from 1 to 10 per cent, in volume. The free acidity which arises from lactic, acetic, galHc, and malic acids, ranges (if reck- oned as glacial acetic acid) from 18 to 45 grains per pint. The sugar has a great tendency to form so-called giucinic (or glucic) acid (C,„H,jOg). There is a small quantity of albuminous matter in most beers, but not averaging more than .5 per cent. The salts average .1 to .2 per cent., and consist of alkaline chlorides and phosphates, and some earthy phos- phates. There is a small amoimt of ammoniacal salt. The dark beers, or porters, contain caramel and assamar. Free carbon dioxide is always more or less present ; the average is .1 to .2 parts by weight per cent., or about If cubic inch per ounce. Volatile and essential oils are also present. Adopting mean numbers, 1 pint (20 ounces) of beer will contain : — Alcohol 1 ounce. Extractives, dextrin, sugar 1.2 " (524 grains). Free acid 25 grains. Salts 13 grains. ' In the Licensing Act (1872), clause 19 contains penalties for using any deleterious substance for mixing with liquors sold by persons having licenses under the Act, and in the first schedule to the Act is a list of deleterious ingredients, viz. : " Cocculus in- dicus, chloride of sodium (otherwise common salt), copperas, opium, Indian hemp, strychnine, tobacco, darnel seed, extract of logwood, salts of zinc or lead, alum, and any other extract or compound of any of the above ingredients." Several articles, which are supposed to be used as adulterants, are omitted from this list. BEVERAGES AXD C0NDIME:N-TS. 295 Physiological Action. — The action on tissue metamoi-pliosis, so far as is known, is suiDposed to be one of lessened excretion ; the urea and pulmonary carbon dioxide being both decreased. If this be the case, it is not caving to the alcohol, at least in moderate dietetic doses, but to some of the other ingredients ; but the experiments require repetition. ^ On the nervous system the action is probably the same as that of alcohol. The peculiar exhausting or depressing action of beer taken in large amount has been ascribed by Eanke ' to the large amount of potash salts, but probably the other constituents (especially the hop) are also con- cerned. When beer is taken in daily excess, it produces gradually a state of fulness and jDlethora of the system, which probably arises from a continual, though slight interference "with ehmination, both of fat and nitrogenous tissues. When this reaches a certain jDoint, appetite lessens, and the form- ative power of the body is impaired. The imperfect oxidation leads to ex- cess of partially oxidized products, such as oxalic and uiic acids. Hence many of the anomalous affections, classed as gouty and biHous disorders, which are evidently connected with defects in the regressive metamor- phosis. The question. What is excess ? is not easy to answer, and will depend both on the composition of the beer, and on the habits of life of those who take it ; but judging from the amount of alcohol which is allowable, from one pint to two pints, according to the strength of the beer, is a sufficient amount for a healthy man. Examination of Beee. This is directed to ascertain — 1. Quality ; 2. Adulterations. 1. QUALITY. Physical Characters. — The beer should be transparent, not turbid. Tm> bidity arises from imperfect brewing or clarifying, or from commencing changes. If the latter, the acidity \nW probably be found to be increased. The amount of carbon dioxide disengaged should neither be excessive nor deficient. The taste should be pleasant. If bitter, the bitterness should not be persistent. It should not taste too acid. Smell gives no indication till the changes have gone on to some ex- tent. If there is any turbidity, microscopic examination will detect the pres- ence of abnormal organisms, as figured by Pasteur.^ 2. Determine Specific Gravity. — If this is done after the alcohol is driven off, an approximate conclusion can be formed of the amount of solids by dividing by 4 the excess of the specific gravity over 1000. The more ex- tract, the greater is the body of the beer. 3. Determine Acidity. — This is a very important matter, as the increase of acidity is an early effect when beer is undergoing changes. The acidity of the beer consists of two kinds. Volatile Acids, viz., acetic and carbonic. ' Binz (Journal of Anatomv and Phvsiologv, May, 1874) states that alcoliol dimin- islies both the pulmonary carbonic acid and urea. - Phys. des Menschen, 1868, p. 139. 2 Etudes sur la Biere, 1876, plate i., p. 6. 296 PEACTICAL HYGIENE. Non- Volatile Acids, viz., lactic, gallic or tannic, malic, and sulphuric, if it has been added as an adulteration. To determine the acidity of beer we must use an alkaline solution of knovrn strength, 1 C.C, of which is equal to 6 milligrammes of glacial acetic acid (C^H^OJ, or to 9 milligrammes of lactic acid (C.HA).' Take 10 C.C of the beer to be examined, and drop into it the alkaline solution from a burette, till exact neutrality (as tested by tui-meric and litmus papers) is reached. Then read off the number of C.C. of alkaline solution used ; multiply by 6, and the result will be the amount of total acidity in the quantity of beer operated on, expressed as milhgrammes of glacial acetic acid (the symbols being always used in the report). By shifting the decimal point two places to the right, the amount per litre is given. To bring grammes per htre into gi'ains per pint multiply by 70, and divide by 20 ; or, what is the same thing, multiply at once the number of C.C. of alkaline solution used by 5.25 (short factor). The total acidity can be divided into tixed and volatile by evaporation. ^Iiile the total acidity is being determined, evaporate another measiu'ed quantity of beer to one-third, make up the original bulk with distilled water, and determine the acidity. The acetic and carbonic acids being volatile, are driven off, and lactic and other acids remain. Deduct the amount of alkaline solution used in this second process from the total amount used, and this will give the amount used for the volatile and fixed acidities respectively ; express one in tei-ms of acetic, the other of lactic acid. Short factor for lactic acid = 7.875. The fixed acidity is greater than the volatile in almost all beers, and sometimes five or six times as much. Example. — 10 C.C. of beer took 5 C.C. of alkaline solution : 5 x 5.25 = 26.45 grains of glacial acetic acid per j)int = total acidity. After boiling and making up to original bulk with distilled water, 10 C.C. took 4 C.C. of alkaline solution : 4 x 7.875 = 31.5 grains of lactic acid per pint = fixed acidity. The difference between the amounts of alkahne solution used, 5 — 4 = 1 multipUed by 5.25, gives the volatile acidity. Generally speaking, the amount of total acidity of beer given ia books is too gi'eat. It is seldom found to be more than 30 grains per pint, and even rarely reaches that ; sometimes it is not more than 14 or 15 grains. In thirty-one kinds of porter and. stout, the acidity per pint vai'ied from 25.22 grains (the highest) to 14.14 grains (the lowest amount). In twenty- three kinds of ale, the highest and the lowest amounts per pint were 34.89 and 7.97 per grain," 4. Determine Amount of Alcohol. — There are various ways of doing this, but one of the two follo^nng wiU be sufficient. Measure a certain quantity, say one pint of beer, and take the specific grarity at 60"" or 68^ Fahr.' 1st. Put into a retort and distil at least two- thirds. Take the distUlate, dilute to original volume with distilled water, determine the specific grarity at 60° or 68° by a proper instrument, and then refer to the annexed table of specific grarities — opposite the found specific gravity the percentage of alcohol is given in volume (not in weight). ' See Appendix A, Vol. II. • British Medical Journal, June, 1870. ' Hassall recommends previous removal of CO., by shaking up in a corked bottle fcr ten minutes, opening the bottle from time to time, and sucking air through it with a tube. This is more necessary with bottled than draught beer. BEVERAGES AND CONDIMENTS. 297 2d. Then, to check this, a plan recommended by Mulder may be used. Take the residue of the beer in the retoi-t, dilute with water to the original volume, and take the specific gTavity at 60° or 68°. Then deduct the specific gTavity before the evaporation from the specific gravity after it, take the difference, and deduct this from 1000 (the specific gravity of water), and look in the table of siDecific gravities for the num- ber thus obtained ; opposite will be found the percentage of alcohol. The results of these two methods should be identical. If there is no retort, this second plan may be used with a common evaporating dish, the alcohol being suffered to escape. A common uiin- ometer (tested for correctness, in the first place, by immersion in distilled water at 62° Fahr. ) may be employed for determining the specific gravity. The plan is veiy useful for medical officers ; it requires nothing but a urin- ometer and evaporating dish, with reasonable care and slowness of evapor- ation, so as not to char the residue and render it insoluble. Alcohol (Volume) according to Specific Gravity. 100 parts. Specific Gravity. 100 parts. Specific Gravity. Alcohol. Water. At 68°. At 60°. Alcohol. Water. At 68°.. At 60°. 50 50 0.914 0.917 24 76 0.966 0.968 49 51 0.917 0.920 23 77 0.968 0.970 48 52 0.919 0.922 22 78 0.970 0.972 47 53 0.921 0.924 21 79 0.971 0.973 46 54 0.923 0.926 20 80 0.973 0.974 45 55 0.925 0.928 19 81 0.974 0.975 44 56 0.927 0.930 18 82 0.976 0.977 43 57 0.930 0.933 17 83 0.977 0.978 42 58 0.932 0.935 16 84 0.978 0.979 41 59 0.934 0.937 15 85 0.980 0.981 40 60 0.936 0.939 14 86 0.981 0.982 39 61 0.938 0.941 13 87 0.983 0.984 38 62 0.940 0.943 12 88 0.985 0.986 37 63 0.942 0.945 11 89 0.986 0.987 36 64 0.944 0.947 10 90 0.987 0.988 35 65 0.946 0.949 9 91 0.988 0.989 34 66 0.948 0.951 8 92 0.989 0.990 38 67 0.950 0.953 7 93 0.990 0.991 32 68 0.952 0.955 6 94 0.992 0.992 31 69 0.954 0.957 5 95 0.994 0.994 30 ,70 0.956 0.958 4 96 0.995 0.995 29 71 0.957 0.960 3 97 0.997 0.997 28 72 0.959 0.962 2 98 0.998 0.998 27 73 0.961 0.963 1 99 0.999 0.999 26 74 0.963 0.965 100 1.000 1.000 25 75 0.965 0.967 Alcohol is sometimes stated as iveight in volume. The following table shows tolerably accurately the relation between the two, and the relative amount of proof-spirit, so that a little calculation wiU reduce one table 298 PRACTICAL HYGIENE. into another, if desired. In other words, if the percentage of alcohol in volume be multipUed by .8, the iveight of the alcohol is given per cent. If the percentage of alcohol in iceight is multiplied by 1.25, the volume is given. If the percentage volume of alcohol be multiplied by 1.76, the amount of proof-i'jnrit is given. ' Per cent. Per cent. in Volume. in Weight. 1 0.8 2 1.6 3 2.4 4 3.2 5 4.0 Proof-Spirit. 1.76 3.54 5.35 7.00 8.80 Per cent. Per cent. in Volume. in Weight. 6 4.8 7 5.6 8 6.4 9 7.2 10 8.0 Proof-Spirit. 10.56 12.32 14.00 15.76 17.60 5. The solids can be determined by evaporation, and the ash obtained by incineration ; but medical officers will seldom have occasion to do this. The specific gravity of the de-alcoholized beer gives a sufficient approxi- mation. 6. Evaporate the beer to a syrupy consistence ; it should have a pleas- ant bitter taste. The points, then, to be determined in judging of quality are — 1. Taste ; 2. Appearance ; 3. Microscopic characters ; 4. Specific gravity of de-alco- holized beer, from which we find the per cent, of extract ; 5. Acidity ; 6. Amount of alcohol ; 7. Taste of syrupy extract. 2. ADULTERATIONS OF BEER." 1. Water. — ^Probably the most frequent adulteration ; detected by taste ; determining amount of alcohol and specific gravity of the beer free from alcohol. 2. Alcohol. — Seldom added ; the quantity of alcohol is large in propor- tion to the amount of extract, as determined by the specffic gravity after separation of the alcohol. 3. Sodium or Calcium Carbonate in order to lessen Acidity. — Neither adulteration can be detected without a chemical examination. Evaporate beer to a thick extract, then put in a retort, acidulate with sulphuric acid, and distil ; if calcium or sodium acetate be present, acetic acid in large quantity will pass over. The extract always contains some acetate, but only in small quantity. Lime. — Evaporate to dryness another portion of beer, incinerate, dis- solve in weak acetic acid, and precipitate by ammonium oxalate. In un- adulterated beer the precipitate is moderate only. Excess of soda, for some always exists in beer, is detected with much greater difficulty, and it will be w'ell not to attempt this. Mulder states that the presence of too great a quantity of lactates may be determined by boiling the beer with zinc carbonate, when lactate of zinc deposits." In ' For method of testing by Sykes' hydrometer, see Appendix, Vol. TI. * In his speech in the House of Lords (April 17, 1872, Times' report), Lord Kimherley stated that a common adulteration is as follows : A certain amount of beer is drawn from the cask of 84 gallons, and then 6 lb of "foots" (a black coarse sugar), 1-i gallon of *' finings " (made from skins of soles and other fish), and 12 gallons of water are put in per cask. This beer is ready for sale in two hours, and must be drunk in two days or it goes bad. Salt and copperas are added by some, but the use of copperas is said not to be general. Ale and stout are not mixed with water, but " finings " are used. ' De la Biere (French edition), 1861, p. 258. BE7EEAGES AND CONDIMENTS. 299 these cases the beer has begun to change, and the microscope and refer- ence to Pasteur's plate Avill greatly assist. 4. Sodium Chloride. — Tlus is hardly an adulteration, unless a veiy large quantity is added/ Take a measured quantity of the beer ; evaporate to dryness ; incinerate at as low a heat as possible ; dissolve in water, and determine the chlorine by the standard solution of nitrate of silver. 5. Ferrous Sulphate.— il the beer be hght-colored, a mixture of potas- sium ferricyanide and ferrocyanide (Faraday's test) may be added at once, and will give a precipitate of Prussian blue ; if the beer be veiy dark- colored, it must be decolorized by adding solution of lead subacetate and filtering. Or evaporate a portion of beer to dryness and incinerate ; if any iron be present the ash is red ; dissolve in weak nitric acid, and test with po- tassium ferrocyanide. Two grains of ferrous sulj^hate to nine gallons of water give a red ash (HassaUj. The ash of genuine porter is always whit-e, or grayish white (HassaU). 6. Sulphuric acid is added to clarify beer, and to give it the hard flavor of age. If the beer be pale, add a few drops of hydrochloric acid, and test with barium chloride. A very dense precipitate may show that sul- phui-ic acid has been added, but it must be remembered that the water used in brewing may contain lai-ge quantities of sulphates. (The Burton spring water is rich in calcium sulphate.) If theie be a large precipitate, then determine the acidity of the beer before and after evaporation ; if the amount of fixed acid be found to be very large, there will be no doubt that sulphuric acid has been added ; or precipitate with barvia, and weigh. Mulder recommends that the extract of the beer be heated, and the suljDhur dioxide which is disengaged led into chlorine water ; sulphuric acid will be found in the chloiine water, and may be tested for as usual. 7. Alum. — Evaporate to dryness ; incinerate, and proceed exactly as in the analysis of alum in bread. The substance added to give " head " to beer is a mixture of alum, salt, and ferrous sulphate. 8. Burnt Sugar — Essentia bina — Foots. — Evaporate the beer to an ex- tract ; dissolve in alcohol ; evaporate again to extract, and taste. Accord- ing to Pappenheim, these substances prevent the regressive metamorphosis of the tissues, and thus injure health. Burnt sugar is added to porter to give color, and the addition is not illegal. 9. Capsicum — Peppers — Grains of Paradise. — Evaporate to dryness carefully ; dissolve in alcohol ; filter ; evaporate very carefully to dryness, and taste if there is any pungency. In fourteen out of twenty samples of ilhcit beer, iMr. Phillips found that grains of paradise had been added. It is said that the oils of pimento, zedoary, and ginger are sometimes used. 10. Aloes.— The taste alone is not reliable. Dr. Koehler' proposes to evaporate the beer. Dissolve the residue in nitric acid, when a yellowish- red Hquid is obtained, which takes a deep blood-red color when treated with hq. potassse and glucose, or with liq. potassae and either cyanide of potassium or sulphide of ammonium, if aloe-resin is present. The nitric acid solution is not decolorized by stannous chloride ; if hops only have been used, it is decolorized. 11. Colocynth. — The residue of evaporated beer, heated with nitric acid, yields a yellow solution ; with concentrated sulphuiic acid, an intense ' The Inland Eevenue Office allows 50 grains of sodium cMoride per gallon. 2 Sclimidt's Jalixb., 1871, No. 10, p. 23. 300 PRACTICAL HYGIENE. red solution ; and a clierry-red color is given with Froelide's test (molyb- date of sodium dissolved in svdphuric acid).' 12. Colchicin. — A case is recorded by Dr. Buttern ^ of Faaborg, in Nor- way, where colchicin was detected in some English beer, and caused symp- toms of poisoning (vomiting, diarrhoea, burning pain in the head, stom- ach, etc.). 13. Santonin. — Evaporate beer to extract ; treat with alcohol, filter, evaporate, and prejDare the santonin as usual by boiling with lime, and precipitating by an acid. 14. Cocculus indicus. — It is not knoANTi whether much of this is now used. The witnesses examined in 1856 by the Committee of the House of Commons (Scholefield's) all doubted it ; a large quantity of Cocculus indicus is, however, annually imported, and no other use is known.' In two instances out of twenty specimens of adulterated beer, analyzed in 1863 by Mr. Phillips, Cocculus indicus was found in large quantities. For the detection of Picrotoxine, Herapath recommends that the beer be first treated with lead acetate ; filtered ; excess of lead got rid of b}' hydrogen sulphide ; fluid evajiorated to a small bulk, and mixed with ani- mal charcoal. The charcoal absorbs the picrotoxine ; it is boiled in alco- hol, and the alcohol is evajDorated on slips of glass. The j^icrotoxine crystallizes as plumose tufts of cii'cular or oat-shaped ciystals. Dr. Langley, of Michigan,^ recommends acidulating the beer with hydrochloric acid and agitating with ether ; the ethereal solution yields on evaporation crystals of picrotoxine. A jDlan demised by Depaii-e is considered by Koehler as one of the easiest and at the same time the best. Mixonehtre of beer with finely powdered rock salt : resinous and extractive matters are thrown down. Shake the liquid with ether ; an impure pici'otoxine is obtained, which can be purified. None of these j^rocesses will give more than y*oths of the picrotoxine. "VMien the crystals of picrotoxine are obtained, test them as follows : — (a) Eub the crystals with 3 or 4 parts of pure nitrate of potassium ; add 1 or 2 drops of strong sulphuric acid, and then an excess of strong solution of soda or potash. A bright reddish-yellow color is given, if picrotoxine be pi-esent (Langley). (b) Dissolve the crystals in strong sulphuric acid ; a yellow fluid is ob- tained. Stir it with a glass rod which has been dipjDed in a concentrated solution of potassium bichromate ; a bluish-violet color is obtained i like a strychnine reaction), which changes soon into brown, bro-oTi green, and at last apple green. (c) If a good deal of picrotoxine is obtained, dissolve it in water, and put a small fish in the water ; the poisonous effects occur in a short time. 15. Strychnine or Nux Vomica. — This is a very uncommon adulteration, if it ever occur. Add animal charcoal to the beer ; digest for twenty-foiir hours ; pour off the beer ; boil the charcoal in alcohol ; filter ; evaporate one-half ; add a few di'ops of liquor potassae and then ether ; agitate ; poiu: off ether, and evaporate to dr^-ness ; test for strj'chnine by the color test (sulphuric acid and potassiiun bichromate, or peroxide of lead, or man- ganese, or potassium peiToanganate).^ 16. Tobacco is occasionally used ; in twenty specimens of illicit beer 1 Koeliler, op. cit. 2 Med. Times and Gazette, May 16, 1874, p. 29. ' It is said to be obtainable from wholesale druggists under the name of inultum. * Chemical Xews, September 6, 1862. * Other vegetable bitters are used, but their detection is difficult and uncertain. Mr. Sorby recommends the spectroscope for detecting calumba root. BEVERAGES AND CONDIMENTS. 301 examined in 1863 by Mr. Phillips, of the Inland Eevenue Department, to- bacco was found in one. 17. Picric {Trinitrophenic) Acid. — Lassaigne reeommeHds the addition of subacetate of lead and animal charcoal ; if the beer has still a yellow color, picric acid is present. But, as Mulder and Hassall obsei-ve, many beers destitute of picric acid remain yellow. Pohl advises to add white uncombed wool ; if picric acid be present, it stains it. This is an uncer- tain test. H. Brunner extracts the picric acid from the wool with hot aqueous ammonia ; concentrates to a small bulk, and tests with a drop of solution of cyanide of potassium. A red coloration of isopurpm-ate of potassium will be produced if there be 1 part of picric acid in 500,000 of water (Hassall). , 18. Copper. — Evaporate a portion of the beer to dryness; incinerate; dissolve in weak nitric acid ; test for copper by the insertion of a clean knife ; by addition of ammonia and of potassium ferrocyanide. 19. Lead. — Evaporate a considerable quantity of the beer to dryness ; incinerate ; dissolve in weak nitric acid, and test for lead as usual Sub-Section IL — Weves.' Composition. The composition of wine is so various that it is difficult to give Cj sum- mary. The following are the chief ingi-edients : — 1. Alcohol. — From 6 to 25 per cent, volume in volume, of anhydrous alcohol. It has been, however, stated that the fermentation of the grape, when joroj^erly done, cannot yield more than 17 per cent., and that any amount beyond this is added," Some of the finest wines do not contain more than 6 to 10 per cent. Per cent, of Alcohol (Volume in volume). Port {analyzed in England) 16.62 ' to 23.2 Sherry [analyzed in Eyigland) 16 "25 Madeu'a {analyzed in England) 16. 7 "22 Marsala {analyzed in England) 15 "25 Bordeaux wines, i-ed (mean of 90 determinations of dif- ) ferent sorts : Chateau Lafite, Margaux, Larose, St. > 6.85 " 18 Emilion, St. Estephe, etc.) . . . . , ) Bordeaux -wines, white (mean of 27 determinations of) -,-. "18 7 sorts : Sauternes, Barsac, Bergerac, etc.) f * ' Rhone wines, red (Hermitage, Montpelher, Frontignan, ) n « "1^7 etc.) j ' For a fall account of wines, see tlie work by Thudicliuni and Dupre (Origin, Nature, and Use of Wine, 1872). ^ Mulder (On Wine, p. 186) quotes Guijal to the effect that pure port never contains more than 12.75 per C;nt. of pure alcohol; but Mulder doubts this. Dr. Gorman stated before the Parliamentary Committee that pure sherry never contains more than 12 per cent, of alcohol, and that 6 or 8 gallons of brandy are added to 108 gallons of sherry. Thudichum and Dupre (On Wine, p. 682) state that a natural wine may con- tain a minimum of 9, while the maximum limit is 16 per cent, (of weight in volume). They also state that a pipe of 115 gallons of port wine has never less than 3 gallons of brandy added to it, and the rich port wines have 13 to 15 gallons added. It would seem that the natural wines of Australia contain a larger quantity of alcohol in some instances than any European wine. ^ Some port used in the Queen's establishment contained only 16.62, and the high- est percentage was 18.8 (Hofmann). The sherry contained only 16 per cent, and the claret 6.85 to 7 per cent. The highest percentage found by Thudicum and Dupre in. port wine was 19.2 per cent, of weight in volume — 23.4 per cent, volume in volume. 302 PRACTICAL HYGIENE. Per cent, of Alcohol (Volume in volume). Eoussillon 11 to 16 Bui-guudy, red (Beavme, Macon) 7.3 " 14.5 white (ChabUs, etc.) 8.9 " 12 Pyrenean 9 " 16 Champagnes 5.8 " 13 MoseUes 8 " 13 Rhine wines (Johannisberger, Hochheimer, Rudeshei- ) r 7 " 16 mer, etc.) j Hungarian "\\ine 9. 1 " 15 Italian 14 " 19 Syria, Corfu, Samos, Smyrna, Hebron, Lebanon 13 " 18 So various is the amount of alcohol in wines from the same district, that a very general notion only can be obtained by tables, and a sample of the wine actually used must generally be analyzed. To tell how much ])m-e alcohol is taken in any definite quantity of wine, measui-e the wine in ounces, multijily it by the percentage of alco- hol, and divide by 100. 9 X 13 Example. — "Wine drank being 9oz., and the percentage 13, then = 1.17 oz. of absolute alcohol by measm-e. The amount of alcohol can be deteiTnined by distillation or eA"aporation, as given in the section on Beer. Instniments, however, are required, which indicate a less specific gravity than pure water. If the medical officer has only a common uiinometer, the only plan will be to dilute with an equal part of pure water at 60', and then to add a little salt, so as to bring the specific gi-avity above that of the water ; then evajDOi-ate as usual. Take the difterence of the specific gravities (before and after evaporation) ; de- duct from 1000, and look in the specific gravity table (p. 297), for the amount of alcohol in the diluted vdne ; by multiphdng the result by 2, the percentage of alcohol in the undiluted wine is found. Sometimes, besides ethyl alcohol, small quantities of projDyl, butyl, and amyl alcohols are found in wine. A little acet-aldehyde is present in some Greek wines (Thudichum and Dupro), but is not considered to indicate unsoundness.' 2. Ethers. — Qi^nanthic, citric, mahc, tartaric, racemic, acetic, butyi-ic, caprs-Hc, caproic, pelargonic, and many others. Dr. Dupre states that there ai"e 25 or even more compound ethers in wine, and some of them are in veiy small quantities. The "bouquet" of wine is partly owing to the ethers (especially to the volatile) — partly, it is said, to extractive matters. (Enanthic ether is that which gives its characteristic odor to wine. Dr. Dupre has given a veiy good plan of estimating the amount of the volatile and nonvolatile ethers, but it is too delicate for medical oflicers.^ 3. Albuminous Matters — Extractive Coloring Matter. — The quantity of albumen is not great ; the extractives and coloring matter vary in amount. The coloring matter is derived from the skins ; it is naturally greenish or blue, and is made violet and then red by the free acids of wine. The bluish tint of some Burgundy wines is owing, according to Mulder, to the very small amount of acetic acid which these wines contain. It is, accord- ing to Batilliat, composed of two mattei's — rosite and pui'pm-ite. "With age ' If it is present in white wines (such as Sautemes) it is a certain sign of unsound- ness. * Chem. Journal, November, 1867, and Origin, Nature, and Use of Wine. BEVERAGES AND CONDIMENTS. 303 clianges occur in the extractive matters ; some of it falls (apothema), especially in combination with tannic acid, and the wine becomes pale and less astringent. 4. Sugar exists in varying amounts, and in the form for the most part of fruit sugar. Sherry generally contains sugar, but not always ; it averages 8 grains per ounce ; ' and appears to be highest in the brown sherries, and least in Amontillado and Manzanilla. In Madeira it varies from 6 to 66 grains per ounce ; in Marsala a little less ; in Port, from 16 to 34 grains per ounce, being apparently greatest in the finest wines. In Champagne it amounts to from 6 to 28 grains, the average being about 24 grains. In the Clarets, Burgundy, Rhine, and Moselle wines, it is absent, or in small amount. In determining the sugar, if the copper solution be used, the coloring matter is acted on by the alkali of the copper solution, and interferes with the appreciation of the change of tint, and must be got rid of by acetate of lead, animal charcoal, boiling, and filtering. If any substance exists which is still tiu'ned green by the alkali of the copper solution, the wine must be neutralized, evaporated to dryness, and the sugar dissolved. As a rule, the copper solution employed directly with wine gives \ per cent, too much sugar (FehUng), and a correction to this amount should be made.^ 5. Fat. — A small amount exists in some wines. 6. Free Acids. — Wine is acid from free acids and from acid salts, as the potassium bitartrate. The principal acids are racemic, tartaric, acetic, malic, tannic (in small quantities), glucic, succinic, lactic {?), carbonic, and fatty acids, such as formic, butyric, or propionic. Some acids are volatile besides the acetic, but it does not seem quite certain what they are. The tannic acid is derived from the skins ; it is in greatest amount in new Port wines ; it is trifling in Madeira and the Rhine wines ; it is present in all white and most red-fruit wines, except Champagne. The tannic acid on keeping precipitates with some extractive and coloring matter (apothema of tannic acid). 7. Salts. — The salts consist of bitartrate of potassium, tartrates of cal- cium and sodium, sulphate of ]3otassium, a little phosphate of calcimn and magnesium, chloride of sodium, and iron. The magnesia is in larger amount than the hme, and exists sometimes as malate and acetate. A little manganese and copper have been sometimes found. In Rhine wine a little ammonia is found (Mulder). The total amount of salts is .1 to .3 per cent. — i.e., about 9 to 26 gi'ains per pint, or ^ to 1|- grain per ounce. The salts can only be detected by evaporation and ignition. 8. The total soHds in wine vary from 3 to 14 per cent., or in some of the rich liqueur-like wines to more. The specific gravity depends uj)on the amount of alcohol and of sohds, and varies from .673 to 1.002 or more. An approximate notion can be formed of the total solids by taking the specific gravity, after driving off the alcohol by evaporation and then repla- cing the water. Examination of Wine. The quahty of wine can be best determined by noting the color, tran- sparency, and taste, and then determining the following points : — (1.) The amount of solids as given by the specific gravity after the ehm- ■ Bence Jones, in Mulder on Wine, p. 386. ^ The addition of extraneous sugar to wine may be detected by the use of the sac- tharometer along with Fehling's solution. 304 PRACTICAL HYGIENE. ination of the alcohol. In the best clarets, before the loss of alcohol, the specific gravity is very nearly that of water. In some claret used in the Queen's establishment, and analyzed by Dr. Hofmann, the specific gravity was .99952. In other clarets it is as low as .995. A low specific gravity shows that alcohol has been added, or that the solids are in small amount. (2.) The amount of alcohol ; a very small amount may show the addition of water ; a large amount the addition of spirits. (3.) The amount oifree acidity. This is an important point, as it seems clear that some persons (especially the sick) do not readily digest a large amount of acid and acid salts. The amount is detemiined by the alkaline solution. The free acidity is generally reckoned as crystallized tartaric acid (0,11^0^), 1 C.C of the alkaline solution being equal to 7.5 milligi'ammes. There is both fixed and volatile acidity ; the relative amount of the two is diflficult to determine satisfactorily, as some acid may be formed on distillation. The distillation should be conducted at a low temperature, so as not to decompose the fixed compound ethers. The volatile acidity is reckoned as glacial acetic, the fixed as tartaric acid. All the acidities of wine are usually reckoned as grains per ounce. The amount of free acidity varies greatly even in the same kind of wines ; the least acid wines are Sherry, Port, Champagne, the best Claret, and Madeii-a ; the more acid wines are Burgundy, Khine wine, Moselle (Bence Jones). The amount of free acid in good Clarets is equal to 2 to 4 grains of tartaric acid per ounce ; in common Clarets and in Beaujolais, it may be 4 to 6 grains, and in some extremely acid wines it may be even more than this. In the best Champagnes it is 2 to 3 grains usually ; but it has been known to reach in excellent Champagne 1.12 per cent., or 4.8 grains jDcr ounce.' In Port it averages 2 to 2^ grains, but may reach 4 grains ; in Sherry \^ to 2| grains ; in the Rhine wines, 3^ to 4 or 6 grains. Thud- ichum and Dupre state that in good sound wine the amount of free acidity ranges fi"om .3 to .7 per cent., or from 1.3 to 3 grains per oimce. The taste of wine does not depend entirely on, bvit jei is very greatly influenced by, the degree of acidity. Mr. Griffin^ states that good-tasted wine contains from 1.87 to 2.8 grains of crystallized tartaric acid per ounce ; that if it contains less than 1.87 grain, it tastes flat ; that if more than 3 grains per ounce, the wine is too acid to be agreeable ; if more than 4.37 gi-ains per ounce (1 per cent.), it is too acid to be drunk. These numbers seem rather low.^ (4.) The amount of sugar. The best modes of determining this have been already noticed. (5. ) It may be sometimes useful to determine the amount and kind of ethers by fractional distillation. Excessive acidity of wine can be corrected by adding neutral potassium tartrate. Milk is also often used. The addition of the carbonated alkalies, or of chalk, alters the bouquet of the wine. When wine becomes stringy, in which case acetic and lactic acids are formed, it may be improved by adding a little tea ; about 1 ounce of tea boiled in 2 quarts of water should ■ This was the case in some Champagne examined by Dr. Hofmann. 2 Report on Cheap Wine, by R. Druitt, M.D., p. 178. ^ From thirteen analyses of sound ordinary Port, I found the mean acidity to be 1.97 per ounce; in some samples of Sherry, 1.90; Marsala, 1..5 ; light Claret, '6.1 ; in a rather sour Claret, 4.0; in a sample of Montilla, a fine wine, but too acid, 3.15. — • (F. de C.) BEVERAGES AND CONDIMENTS. 305 be added to about 40 gallons of wine. Bitter wine is treated with bard water or sulphur ; bad-smelKng wine with charcoal ; too astringent wine with gelatin ; wine which tastes of the cask with olive-oil.' Adulterations of Wine. 1. Water. — Known by taste ; amount of alcohol ; specific gravity after elimination of alcohol 2. Distilled Sjyirits. — Known by determining the amount of alcohol; the normal percentage of the particular kind of wine being known. By frac- tional distillations the peculiar-smelling fusel oils may be obtained ; or merely rubbing some of the vnne on the hand, and letting it evaporate, may enable the smell of these ethers to be perceived. 3. Artificial Coloring Matters. — The following are the chief coloring matters, as stated by Thudichum and Dupre, Logwood is the great coloring material, and also blackberries, elderberries, and bilberries. There are no good methods of recognizing these substances ; salts of lead, ammonia, and ammonium sulphide, alum, and potassium or ammonium carbonate, and salts of tin, have been used as re-agents. The most useful test appears to be this : add to the wine about :^th volume of strong solu- tion of alum ; stii* well, and then add about an equal quantity of strong solution of ammonium carbonate ; the natiu'al coloring matter of the wine, when thrown down in this way, has a greenish or dirty bluish-green color,- but there is no tinge of red ; ]og"wood and several other abnormal colors, have a distinct red or pur^Dhsh tint.^ The use of strips of gelatin, as described under Alum in Bread, is also recommended. Fuchsine or rosanihne and other substances have also been used, but on the whole there has been some exaggeration, whilst the coloiing matters employed are mostly harmless. 4. Lime Salts. — The so-called "platrage" of wines consists in the addi- tion of 1^ ft) to 7 ft) of a mixtui'e of calcium sulphate (80 parts), calcium carbonate (12), quicklime and sulphide and chloride of calcium (8 parts) to 1 hectolitre of wine. Calcium sulphate dissolves in large proportion, and then interchanges with the chloride of potassium, and chloride of calcium and sulphate of potassium are formed. The chalk forms acetate and tar- trate of calcium. The proportion of lime salts is then verj' lai-ge. The only precise way of detecting this adulteration is by evaporating to diyness, incinerating, and determining the amount of liiue. But the following method is shorter, and will generally answer. The natural hme salts of wine are tartrate and sulphate ; when hme is added, an acetate of calcium is formed. Evaporate the wine to y^th ; add twice the bulk of strong al- cohol ; the calcium acetate is dissolved, but not the sulphate or tartrate ; filter and test mth oxalate of ammonium ; if a large precipitate occur, hme has probably been added. 5. Tannin may be detected either by chloride of ii'on or by adding ^ Wine is subject to several diseases, -wliich, according to Pasteur, depend on differ- ent kinds oi: ferments (see Review on Hygiene, in Army Medical Department Reports, vol. vii., p. 340). By heating the wine to about 125°-130" Fahr. these "mycoderms" are killed, and the wine undergoes no further change. The microscope may be em- ployed, as in the case of Beer. - Mulder speaks very doubtfully of all such tests ; they seem, however, better than nothing. Probably the spectrum analysis will hereafter afford the best means of iden- tification. On the coloring matter of wine, see Duclaux, Comptes Rendus de I'Acade- mie des Sciences, t. Ixxvii. , Xo. 16, April, 1874, p. 1159 ; also Report on Hygiene, Army Med. Reports, vol. xv. , p. 190. Von. I.— 30 306 PRACTICAL HYGIENE. gelatin ; but as tannin exists naturally in most of the red wines (Port, Beauue, Roussillon, Hermitage, etc), the question becomes often one of quantity. The amount of tannin can be estimated by drying the tanno- gelatine (100 grains contain 40 of tannin). 6. Alum. — This is detected precisely in the same manner as in bread. Evaporate a pint of the wine to dryness ; incinerate, and then proceed as directed in Bre.\d. 7. Lead. — Evaporate to dinniess, and incinei-ate ; dissolve in dilute nitric acid, and test as directed in the Examination of Water. 8. Copper. — Decolorize with animal charcoal, and test at once with ferrocyanide of potassium. 9. Cider and Perry. — Evaporate wine, and the peculiar smell of the hquids will be perceived. Port wine, as sold in the market, is stated to be a mixture of true Port, Marsala, Bordeaux, and Cape Avines mth brandy, although at present it is probably purer than it used to be — purer, perhaps, than most other wines. Inferior kinds are still adulterated with logAvood, elderben'ies, catechu, prune juice, and a little sandalwood and alum. Receipts are given in books for all sorts of imitation wines. Sub-Section HE. — Spirits. The Queen's Fegidaf ions for the Army (1881, sec. 15, paragi-aph 60) for- bid the sale of spu-its in canteens at home, but permit it in foreign stations at the discretion of the commanding officer. Brandy contains, besides alcohol, cenanthic ether, acetic, butyiic, and valerianic ethers. Tannin, and coloring matter from the cask, or from caramel, are present. If sugar is present in any quantity, it must have been added. The inferior kinds of brandy, prepared from potatoes as well as grain, contain potato fusel-oil. Rum contains a good deal of butjTic ether, to which the aroma is chiefly owing. Gin, besides contain- ing the oil of juniper, is flavored with various aromatic substances, as Calamus aromaticus, coriander, cardamoms, cinnamon, almond-cake, and orange-peel ; Cayenne is often added. Whiskey often derives a peculiar flavor from the malt being dried over peat fires, or by the direct impreg- nation of peat smoke. ' Peach stones and pine sawdust are also said to be added. ' It may te worth while to give the names of some of the distilled spirits used in different parts of the world, as the army surgeon may meet with them in the course of service : — • Nations by whom employed. Name. Obtained from Hindus, Malays, etc Arrack. Rice or Areca-nut. Greeks, Turks, etc Raki. Rice. Hindus Toddy. Cocoa-nut. ' ' (Mahrattafi) Bojah. Eleusine Corocana. " (Sikkim) Murwa. " " Chinese Samshoo. Rice. Japanese Sacie. .... Pacific Islanders Kawa. Macropiper. Mexicans Pulque. Agave. South Americans Chica. Maize. Tartars Koumiss. Mares' milk. Russians and Poles Voldki. Potato. Abyssinians Talah. Millet. BEVERAGES AND CONDIME^iTS. 307 Composition of Spirits. The following table gives the chief points of importance : * Name. Sp. gr. at 62° F. Alcohol per cent, Solids , , Acidity per ounce, reckoned as tartaric acid. Sugar per cent. Brandy .929-. 934 .930-. 944 .915-.920 .974-. 926 50-60 49-60 50-60 60-77 1.2 .05 to 0.2 0.2 0.1 0.6 trace 1.0 0.1 1 grain 0.2 " 0.2 " 0.5 " or traces Gin Whiskey Bum 1 Alcohol as an Article of Deet ix Health." In endeavoring to deteiTaine the dietetic value of alcoliolic beverages, it is desirable to see, in the lirst place, "what are the effects of their most important constituent, viz., alcohol. Thfee sets of arguments have been used in discussing this question, drawn, namely, from — 1, the physiological action of alcohol ; 2, experience of its use or abuse ; and 3, moral considerations. The last point will not be further alluded to, for without undeiTating the great weight of the argument drawn from the misery which the use of alcohol produces, — a miseiy so gi'eat that it may truly be said, that if alco- hol were unknown, half the sin and a lai'ge pai't of the jDOverty and un- happiness in the world would disappear, — yet this part of the subject is so obvious that it seems unnecessaiw to occupy space v*ith it. The ar.guments, however, which are strongest for total abstinence, are di'awn fi'om this class. Nor does any one entertain a moment's doubt that the effect of intemperance in any alcohohc beverage is to cause prematiu'e old age, to produce or predisjDose to numerous diseases, and to lessen the chance of living very gi'eatly. The table given below, ^ taken fi'om Xeison's Vital Statistics, puts this in a strong hght. ' This table is cMefly taken from Bence Jones' Observations ; Appendix to Mulder on Wine, p. 889 ; and from Hassall's Food and Adulteration, p. 645. ^ The subject of spirits in sickness is another point altogether. Dr. Parkes believed they were often of great use, although, like every other strong medicine, they require to be given carefully. ^Effects of Intemperance (Xeison's Statistics, p. 217 et seq.) : — Batio per cent, from the under-mentioned CaiMss, to Deatfts from aU Causes. Cause of Death. 1847. Gotha Life Office. Scottish Widows' Fund. Intemperate Lives. Head diseases 9.710 6.240 88.150 15.176 8.377 27.843 20.720 11.994 23.676 27.10 Digestive organs (especially those ( of the liver) .' ) Eespiratory organs 23.3 22.98 ' Total of above three classes . . . 49.100 51.396 56.390 73.38 It thus appears that tbe intemperate have a much greater mortality from head and digestive diseases than other classes. 808 PRACTICAL HYGIENE. The physiological argument for the nse or disuse of alcohol requires to be used with caution, as our knowledge of the action of jxire alcohol (much more of the alcoholic beverages) is imperfect. "When taken into the stomach, alcohol is absorbed without alteration, or is perhaps in some small degi'ee converted into acetic acid, possibly by the action of the mucus or secretion of the stomach. The rate of absorp- tion is not known, and it has been supposed that when given in very large c[uantities it may not be absorbed at all. It has not, however, been In intemperate persons the mortality at 21-30 years of age is five times that of the temperate ; from 30-40 it is four times as great. It becomes gradually less. A Temperate person's chance of living is. At 20 = 44.2 years. . " 30 = 36.0 " " 40 = 28.8 " «' 50 = 21.25 " " 68 = 14.285 " An Intemperate person's chance of living is, At 20 = 15.6 vears. " 30 = 13.8 ' " " 40 = 11.6 " " 50 = 10.8 " " 60= 8.9 " All these deductions appear to be drawn from observations on 357 persons, with 6,111.5 years of life. The tacts connected with these persons are well authenticated, but the number is small. The average duration of life after the commencement of the habits of intemperance is — Among mechanics, working and laboring men 18 years. " traders, dealers, and merchants 17 " " professional men and gentlemen 15 " " females 14 " Those who are intemperate on spirits have a greater mortality than those intemper- ate on beer. Those who are intemperate on spirits and beer have a slightly greater mortality than those intemperate on only spirits or beer, but the difference is immaterial. Mortality per annum. Spirit drinkers 5.996 per cent, (nearly 60 per 1,000). Beer drinkers 4.597 per cent, (nearly 46 per 1,000). Spirit and beer drinkers 6.194 per cent, (nearly 62 per 1,000). Very striking evidence in favor of total abstinence, as contrasted with moderation, is given by the statistics of the United Kingdom Temperance and General Provident Institution. One section consists of abstainers, another of persons selected as not known to be intemperate. The claims for five years (1860-70), anticipated in the Tem- perance section, were £100,446 ; but there were actually only claims for £72,676. In the general section, the anticipated claims were £196,352 ; and the actual claims M-ere no less than £230,297. The much greater longevity of the abstainer is better seen by the amount of bonuses paid to each £1,000 whole-life policy in the two sections for the same five years. Age at Entrance. Premiums paid. Bonus added in Temperance Section. Bonus added in General Section. 15 £ 8. d. 83 3 6 93 6 8 106 9 2 122 1 8 138 19 2 162 5 10 188 10 10 226 5 284 3 4 £ 8. d. 61 1 64 68 10 74 78 19 86 92 18 104 2 122 14 £ 8. d. 35 10 20 37 25 40 30........ 35 0.... 40 43 46 50 4 45 54 50 60 13 55 71 11 BEVERAGES AKD CONDIMENTS. 309 recovered from the faeces in any great amount. After absorption it passes into the blood and then throughout the body ; if the obseryations of Schulinus ' are correct, it is equally distributed, and does not accumulate, as was formerly supposed, in the liver and nervous tissue. It can easily be detected in all the organs soon after it is taken. It commences to pass out from the body speedily, as it may be detected in the breath soon, after it is taken ; it emerges by the lungs, by the skin, in smaller quan- tities by the mine, and slightly by the bowels, or this may be merely from unabsorbed portions passing out. The amount recoverable fi'om all these channels is usually small,' but occasionally, when verj^ large quan- tities have been taken, the kidneys excrete it largely, so that the specific gi-a^ity of the mdne has been below that of water, and distillation has given an inflammable fluid. ^ Much debate has taken place as to whether all or how much of the alcohol is thus eliminated, and whether any is destroyed in the body. The experiments of Dr. Percy, and subsequently of Strauch, and especially of Masing in Buchheim's laboratory at Dorpat, followed as they were by the confirmatory observations of 'yDl. Perrin, Lallemand, and Duroy, seemed at one time to have settled the question, and to have proved that alcohol is very httle or not at all destroyed in the body. Since then the criticisms and experiments of Baudot, and especially the observations of Schvihnus,^ Anstie," Diiprie, and Subbotin, have again altered the position, and al- though the experimental evidence is incomplete (chiefly on account of the difficulty of collecting the amount given off by the lungs and skin), the opinion that some, and perhaps much, alcohol disappears in the body is generally admitted. ° At everv age, therefore, tlie abstainer has a very great advantage, ilr. Vivian, the President of the Temperance and General Provident Institution, brought before the British Association at Bristol, in 1875, the following statistics : Abstinence Section. Greneral Section. Expected. Actual. Expected. Actual. 1866-70 (5 years) 1871-74 (4 years) 549 561 411 390 1,008 994 944 1,033 Totals (9 years) 1,110 801 2,002 1,977 On the Gold Coast, during the Ashantee War, the evidence (slight as it was) was de- cidedly in favor of the teetotallers. — (Parkes, On the Issue of a Spirit Ration, p. 28, 1875. )' ' Archly der Heilk., 1866, p. 97. ^ Experiments on this point by Schulinus, Anstie, Dupre, Thudichum, and others, prove that ordinarily the urinary elimination is slight. When it becomes at all marked, or even when it occurs at all, the detection of alcohol by potassium bichromate and sulphuric acid has been proposed by Anstie as an indication of the point when as much alcohol has been taken as can be disposed of by the body. " A ffood case is given by Dr. Woodman (Medical Mirror, July, 1865). ^ Archiv der HeUk., 1866. 5 Lancet, 1868. ^ The amount eliminated by these channels has been variously stated. The latest observations are by Dupre,' Anstie, and Subbotin.* According to Dupr^. from experi- ments on himself, the amount eliminated by the urine and breath (he did not examine 7 Proceedings nf Royal Societv, Xo. 138 (p. SfiS, 1872). 8 Zeitschrift fUr Boil., Band vii., p. 361 (137S). 310 PRACTICAL HYGIENE. If alcohol is destroyed in the body, through what stages does it pass ? The statement of Duchek, that it forms aldehyde, has been disproved. Its easiest transformation out of the body is into acetic acid ; but, "when ani- mals are poisoned Avith alcohol, Buchheim and Masing could detect no acetic acid in the blood ; still, the amount would be so small it might be overlooked, or the acetic acid might be soon transformed. Lallemand, Perrin, and Duroy could find no oxalic acid. If it be true that the pul- monary carbonic acid is lessened, it cannot be oxidized to carbonic acid and eliminated by the lungs unless the transformation of some other substance ordinarily furnishing carbonic acid is arrested. The mode of destruction is, in fact, unknown. The only point which throws any light upon it is the slight incx'ease of acidity in the urine during the use of al- cohol, which looks as if an acid of some kind were formed out of it. Present experiments show, then, that some portion passes out, and another, and probably the larger portion, is gi-adually destroyed. The place where the pai'tial destruction of alcohol occurs is yet doubtful ; but it is impossible that the transformation takes place in the various gland- cells in which almost all, or all, the changes in the body take place. As the change out of the body which most easily occiu's is the formation of acetic acid, it seems at present most hkely that some of the alcohol is thus the skin) is only a minute fraction of that taken in, and it takes place chiefly in the first nine hours ; subsequently the amount is excessively small. When taken day after day there is no accumulation of alcohol, so that the inference is, that as so little is eliminated almost all must be destroyed. Subbotin's experiments were on rabbits enclosed in a closed chamber through which the air was slowly drawn. Like Duprp, he determined the amount by oxidizing the alcohol obtained into acetic acid by chromic acid ; but he found that not inconsiderable quantities {niclit unbeirdclitlklie Menken) were eliminated through the lungs, and skin, and kidneys in the first five hours. Con- trary to Perrin, Lallemand, and Duroy, he found twice as much passed from skin and lungs as from the kidneys. In 11 hours he found 12. G per cent, was eliminated, and in 24 hours 16 per cent., and he gives reasons for supposing that the difficulties of the experiments (viz., the difficulty of changing all the alcohol into acetic acid ; of obtain- ing the alcohol from the chamber ; of regulating the ventilation ; and by the dimi- nution of absorption at the end of the experiment, and by the limited time the experi- ment could be carried on) made the amount actually recovered far less than it should have been. Anstie made numerous experiments on the urine and sweat, and always found the qi;antities very minute. With regard to the length of time the elimination goes on, Dupre found it to be finished within a few hours ; Subbotin found that the elimination was not quite ended in 24 ; Perrin, Lallemand, and Duroy, found it to go on for 82 hours. The late Dr. Parkes and Count W^oUowicz found that minute quantities could be found in the urine even on the fifth day after a large quantity of brandy had been taken, though the elimination by the lungs ceased much sooner. In some later experiments, with small quantities of beer and wine, Dr. Parkes found the elimination to be finished in 24 hours. Lieben noticed some years ago, that a substance which had some of the characters of alcohol was found in the urine of persons and animals who had taken none. Dr. Parkes and Count W'oUowicz noticed on one occasion that a substance which slightly reduced chromic acid was obtained from the sweat of a man who had taken no alco- hol,' though in other cases E. Smith, British Medical Journal, November 2, 1861) there is certainly no substance of this kind in the sweat. Dupre also found in the urine a substance furnishing acetic acid, forming iodoform, and having a lower specific gravity and a higher vapor tension than pure water. The amount of this substance is so minute that its nature cannot be perfectly made out, but Lieben considers it not to be alcohol, but perhaps to be derived from the odoriferous principles of the iirine. Dupre doubts this, and Dr. Parkes' observation on the sweat shows that it can hardly be so, unless the same odorous siibstances are passing off by the skin. Dr. Parkes doubted whether it was an invariable constituent of urine, as he could find none in the urine of three teetotallers which were examined. » Proceedings of Royal Society, No. 113, p. 87 (IbTO). BEVERAGES AND CONDIMENTS. 311 transformed. The acetic acid would then unite with the soda of the blood, and a carbonate would eventually be formed which would be eliminated with the urine, as in the case when acetates are taken. ' This would ac- count for the pulmonary carbonic acid not being increased. If this view be correct, the use of alcohol in nutrition would be limited to the effects it produces, first as alcohol, and subsequently as acetic acid, when it neu- tralizes soda, and is then changed into carbonate. The first point only (its effect as alcohol) need be considered — Influence of Alcohol on the Organs. 1. On the Stomach. — In very small quantities it appears to aid digeS' tion ; in larger amount it checks it, reddens the mucous membrane, and produces the "chronic catarrhal condition" of Wilson Fox— ^iz., increase of the connective tissue between the glands ; fatty and cystic degeneration of the contents of the glands, and finally, more or less atrophy and dis- appearance of these parts. "^ Taken habitually in large quantities, it lessens appetite. 2. On the Liver. — The action of small quantities on the amount of bile or glycogenic substances, or on the other chemical conditions of the liver, is not known. Applied directly to the liver by injection into the portal vein, it increases the amount of sugar (Harley). Taken daily in large quantities, it causes either enlargement of the organ by producing albumi- noid and fatty deposit, or it causes at once, or following enlargement, in- crease of connective tissue, and finally, contraction of Glisson's capsule, and atrophy of the portal canals and cells, by the pressure of a shrinking exudation. The exact amount necessary to produce these changes in the liver and stomach has not yet been fixed with precision. 3. On the Spleen. — Its action is not known. 4. On the Lungs. — It is said to lessen the amount of carbon dioxide (and of watery vapor ?) in the air of expiration,^ though there are some discrepancies in experiments with different kinds of spirits. E. Smith, for example, found the expired carbon dioxide lessened by brandy and gin, but increased by rum. It is very important these experiments should be repeated, but they show, at any rate, that the usual effect is not to in- crease the carbon dioxide.* In large quantities habitually taken it also alters the molecular constitution of the lungs, as chronic bronchitis and lobar emphysema are certainly more common in those who take much alcohol. ' In experiments on large quantities of alcohol, Dr. Parkes foiind the acidity of the urine slightly increased. This would quite agree with the above view, as the union of the acetic acid or carbonic acid formed fi'om it, with some of the alkali ordinarily united to other acids, would increase the urinary acidity, This case is, of course, not parallel with that of acetate of potash given by the mouth, which makes the urine alkaline from carbonate, as some alkali in that case is introduced. ' These changes were considered by Wilson Fox to be closely allied with those occurring in cirrhosis of the liver, and in the contracted and indurated kidney. See Diseases of the Stomach, 3d edition, p. 125, foot-note ; and also Reynolds' System of Medicine, vol. ii., p. §69, and foot-note. * The effect of red and white French wines and of beer has been very carefully examined by Perrin (Rec. de Mem. de M6d. Mil., 1865, p. 82); a very great diminu- tion in the amount of carbonic acid (from 5.6 to 22 per cent, less being excreted) was noticed in all the experiments. The effect commenced soon, and reached its maximum in the third hour, and ceased in two hours more. The pulse after meals with and with- out wine had equal power, but after a time the pulse fell more when wine was not taken. * See Binz, Journal of Anatomy and Physiology, May, 1874. 312 PRACTICAL HYGIENE. 5. On the Heart and Blood- Vessels. — Alcohol in liealtliy persons at first increases the force and the quickness of the heart's action. Dr. Anstie' confirmed this opinion by careful sphygmographic observ^ations ; these effects are still more marked in febrile diseases if alcoliol acts favorably (in some febrile cases it appears, fi-om Anstie's observations, not to increase the power of the heart j. In a healthy man, Dr. Parkes foimd that brandy" augmented the rapidity of the jDulse 13 per cent., and the force "was also inci'eased ; taking the usual estimate of the heart's work, its daily excess of work, with 4.8 fluid ounces of absolute alcohol, was equal to 15.8 tons lifted one foot. "With claret the results were almost identical. The period of rest of the heart was shortened, and its nutrition must therefore have been interfered with. In another man, Dr. Parkes found from 4 to 8 ounces of brandy produced palpitation and breathlessness. Alcohol causes evident dilatation of the superficial vessels, as shown by the redness and flushing of the skin ; and in these experiments si^hygmographic observa- tions also proved that the arteries dilated more easily before the fuller cur- rent thrown out by the strongly acting heart. If it were not for this yielding of the vessels (produced perhaps by jDaralysis of the vasomotor nerves) alcohol would be a most dangerous agent, as either the strong wave would break the vessel, or the heart would not be properly emptied of the blood during the contraction. It seems likely, therefore, that there must be danger in the use of alcohol when the arteries become rigid in advancing life, if the heart is then susceptible to the action of alcohol. Eventually the vessels of the surface pass into a state of permanent slight enlargement and tui-gescence ; the skin alters in appearance ; and owing to this, persons who take much alcohol soon get the appearance of age. In some diseases, alcohol is said to lessen the frequency of the heart's action ; and Anstie found it increase arterial tension. In such cases there must be peculiar nervous conditions with which we are unacquainted. Dr. Parkes found it usually, if not always, increase the frequency of the heart in dis- ease, and in some patients the rapidity of the heart's action was simply owing to the administration of alcohol. Anstie believed its principal action was on the sympathetic nerve, and the vascular phenomena seem to strengthen this view, while others think it acts especially on the vagus and the heart alone. 6. On the Blood. — The amount of fat is either increased, or it is more visible. The chemical changes in the blood ai*e partially arrested.^ 7. On the Nervous Sj/slem. — In most persons it acts at once as an anaes- thetic, and lessens also the rapidity of imjH'essions, the power of thought, and the perfection of the senses. In other cases it seems to cause increased rapidity of thought, and excites imagination ; but even here the power of control over a train of thought is lessened. In no case does it seem to increase accuracy of sight ; nor is there any good evidence that it cjuickens hearing, taste, smell, or touch ; indeed, Edward Smith's expeiiments show that it diminishes all the senses. In almost all cases moderate quantities cause a feeling of comfort and exhilaration, which ensues so quickly as to ' In a paper read before tlie British Association in 1868 (Medical Times and Gazette, September, 1868). This paper shows that the sphrgmosraphic indications (combined with the urinary test) may give ns a clue to the often difficult question, whether alco- hol is doing good or harm in disease. ' See papers bv Dr. Parkes and Count WoUowicz, in Proceedings of Eoyal Society, Nos. 120 and 132 ; and another paper by Dr. Parkes, No. 136, for the effect of alcohol on the heart during exercise. 3 Harley, Proceedings of Royal Society, March, 1865, No. 62, p. 160. BEVERAGES AND CONDIMEXTS. 313 make it probable the local action on the nerves of the stomach has at first something to do with this. Afterward the increased action of the heart may have an effect. Different spirits act differently on the nervous sys- tem, owing probably to the presence of ethers and oils ; some, as sam- shoo ' and rati, produce great excitement, followed by profound tor- por and depression. Absinthe is also especially hurtful, apparently from the presence of the essential oils of anise, wormwood, and angehca, as well as from the large amount of alcohol. It appears that the properties of absinthe are somewhat different according to the manner in which water is mixed with it, i.e., suddenly or slowly ; in the latter case the particles of the absinthe are more divided, are absorbed more easily, and produce greater effects. In all these cases there can be little doubt that alcohol enters into temporary combination with the nervous structure ; and the evidence from the impairment of special sense and muscular power, im- phes that it interferes with the movements of the nervous currents. 8. On the Ifuscidar System. — Voluntary muscular power seems to be lessened, and this is most marked when a large amount of alcohol is taken at once ; the finer combined movements are less perfectly made. "WTiether this is by direct action on the muscular fibres, or by the influence on the nerves, is not certain. In very large doses it paralyzes either the respira- tory muscles, or the neiwes supplying them, and death sometimes occiirs from the impau'ment to respiration. 9. On the Metamorphosis of Tissue. — This is usually stated to be les- sened, and it has been said that there is a diminution in the elimination of nitrogen (as urea), and of carbon (as carbon dioxide). But the experi- ments ah'eady referred to by Count Wollowicz and Dr. Parkes' prove that the metamorphosis of the nitrogenous tissues is in no way interfered with by dietetic doses. Whether the carbonic dioxide excretion is really les- sened may also be questioned. 10. On the Temperature of the Body. — When alcohol is given to healthy animals in fuU but not excessive doses, the temperature of the body falls. This seems to be shown conclusively by the experiments of Ringer and Richards, Richardson, Binz, Cuny-Bouvier, and Ruge. In healthy men who have been accustomed to take alcohol in moderate quantities, the results are rather contradictory. In a man accustomed to alcohol. Ringer found no change ; in two men, temperate, but accustomed to take beer and sometimes spirits. Dr. Parkes could not detect any raising or lowering of the thermometer either in the axilla or rectum.^ Dr. Mainzer found no fall of temperature^ in trials on himself, but a slight fall in an- other healthy person. Some experiments by Obemier ° and by Fokker ° are ^ Dr. Dnpre analyzed for Dr. Parkes a specimen of the best samshoo from Singapore. It contained in 100 C.C. 23.91 per cent, of alcohol by weight, and this was made up of 23.874 parts of ethyl alcohol, and .036 part of amylic alcohol ; the amount of free acid (almost all acetic) was .105 ; of residue (sugar almost entirely), 6.01, and of ash, .06 per cent. Cheap samshoo gave nearly the same result. There seems to be nothing dele- terious here ; and from inquiries among soldiers who have served at Hong-Kong, it seems doubtful whether good samshoo does produce the effects ascribed to it. It is probably the adulterated (with opium, etc.) article which acts so violently. The Cape brandy is of two kinds— the Cape and the Boer brandy; the latter is stronger, and is sometimes called peach brandy ; this appears to be the hurtful kind. ^ Proceedings of Royal Society, Xos. 120-123 and 136. 3 Ibid. ^ Ueber die Einwirkung des Alkohols, Inau. Diss. Bonn., 1870. * Archiv fiir die ges. Phys., Band ii., p. 494. « Quoted by Husemann,' Jahresb. fiir die ges. Med., 1871, Band i., p. 334. 314 PRACTICAL HYGIENE. also quite negative. On the other hand, Einger, Binz, and Bouvier noticed in some healthy persons a decrease of temperature ; and though some of the experiments are evidently rather inaccurate, and though the faU of temperatm-e was inconsiderable, it is difficult to refuse behef that in some cases there may be a shght depression of temperature. ' In febrile cases the evidence is almost equally diAided. In a man on whom Dr. Parkes was expeiimenting, an attack of catan-h came on with rise of temperature, and alcohol did not apparently affect the heat in the least. O. Weber, Obernier, and Rabow were equally unsuccessful in not- ing a fall in temperature. Binz and C. Bou\-ier " have, however, produced septic fever in animals, and then lowered the febrile heat by large doses of alcohol, in what appears to have been an unmistakable manner, in several cases. We may conclude that the effect of moderate doses on temperature in healthy men is extremely slight ; there is no increase, and in many persons no decrease. In those in whom there is a shght decrease, the amount is trifling. 11. On the Action of the Eliminating Organs. — The water of the urine and the acidity are sHghtly increased ; but Dr. Parkes found other ingre- dients were unaffected. The condition of the skin is not certain. Dr. E. Smith thought the perspiration lessened, but Wej-rich noticed, after spirits, beer, and wine, a large increase in the insensible cutaneous perspiration ; and the eulai'gement of the vessels of the skin would probably lead to in- creased transit of fluid. 12. Bemote Effects of Alcohol. — The degenerative changes which occur so frequently in the stomach, hver, and other organs, by the constant in- troduction of improper quantities of alcohol into the body,^ affect also almost all parts of the body. The brain and its membranes, and its vessels, suffer early and principally ; and Ki-emiansky' has pi'oduced hemorrhagic meningitis and jDathological changes in the brain-vessels and membranes in dogs by giving them alcohol.^ There is no question that several brain diseases, including some cases of insanity, are produced by excess of alcohoL* So, also, degenerative changes in the stomach, liver, lungs, and probably in the kidneys," result from immoderate use. To use Dickinson's expressive phrase, alcohol is the veiy "genius of degeneration." And these alcoholic degenerations are certainly not confined to the notoriously intemperate. They have been seen in women accustomed to take wine in ' Binz doc. cit. ) finds that small (dietetic ?) doses produce no change ; large inebriat- ing doses produce a fall from 8.. 5 to ~i F., lasting for four or five hours. Habit, however, produces tolerance. In the body, after death, the temperature often rises, but if alcohol has been administered previously it does not do so ; hence Binz con- cludes that the effect is arrest of chemical changes in the glands. - See especially Pharmakologische Studien iiber den Alkohol, von C. Bouvier, Berlin, 1872. ^ A very striking paper on this subject has been published by Dickinson (Lancet, November," 1872). It paints, in startling colors, the immense degenerative power of alcohol. ■* Virchow's Archiv, Band xlii., p. 338. ^ See also the experiments by Magnan (Sur rAlcoolisme). ^ Magnan states the two determinations of chronic alcoholism to be dementia and geii- eral pandijisis. '' Anstie and Dickinson have denied that the kidneys suffer in alcoholism in any great degree. It is an open question ; hut the evidence is in favor of kidney degen- eration being one of the effects of alcoholism. Dr. George Johnson states that out of 200 patients with Bright's disease, from all causes, he found no less than 58 were drunkards. BEVERAGES AND CONDIMENTS. 315 quantities not excessive, and who would have been shocked at the imputa- tion that they were taking too much, although in their case the result proved that for them it was excess. The nature of the degenerative changes appears to be in all cases the same, viz., fibroid and fatty changes. Considering, also, the great increase in the action of the heart, and the dilatation of the vessels, it can scarcely be doubted that alcohol in excess is one of the agencies causing disease of the circulatory organs. Is Alcohol desirable as an Article of Diet in Health ? This question is so large and difficult that a satisfactory answer can hardly be given with our present knowledge. The data for passing a judg- ment are partly ph^'siological, but still more largely empii-ical. The obvious useful physiological actions of alcohol are an improvement in appetite, produced by small quantities, and an increased activity of the circulation, which, within certain limits, may be beneficial. It is difficult to perceive proof at present of any other useful action, since it is uncertain whether, duiing its partial destruction in the system, it gives rise to energy. In cases of disease, in addition to its effect on digestion and cir- culation, its narcotizing influence on the nervous system may be some- times useful Beale suggests that it may restrain the rapidity of abnormal growth or development of multipljang cells, and that by such airest it may possibly diminish bodily temperature ; but proof of this has not been given. The dangerous physiological actions in health, when its quantity is larger, are evidently its influence on the nervous system generally, and on the regulating nerve-centres of the heart, and vaso-motor nerves in par- ticular ; '- the imj)airment of appetite produced by large doses, the lessen- ing of muscular strength, and remotely the production of degenerations. Except when it lessens appetite, it does not alter the transformation of the nitrogenous tissues, and the elimination of nitrogen ; nor can it be held to be absolutely proved to lessen the excretion of carbon. If it did so, this effect in health woiild be simply injurious. It is a matter of the highest importance to determine when the Hmit of the useful effect of alcohol is reached. The experiments are few in num- ber, but are tolerably accurate. From experiments made by Dr. Anstie, an amount of one fluid ounce and a half (42.6 C.C.) caused the appearance of alcohol in the ui'ine, which Anstie regards as a sign that as much has been taken as can be disposed of by the body. The late Dr. Parkes and Count Wollowicz obtained almost precisely the same result. "WTaen only one fluid ounce of absolute alcohol was given, none could be detected in the urine. They found that in a strong, healthy man, accustomed to alco- hol in moderation, the quantity given in twenty-four hours that begins to produce effects which can be considered injurious, is something between one fluid ounce (— 28.4 C.C.) and two fluid ounces (56.8 C.C). The effects which can then be detected are slight, but evident narcosis, lessening of appetite, increased rapidity of rise in the action of the heart, greater dila- tation of the small vessels as estimated by the sphygmograph, and the ^ This influence is probably a paralyzing agency, arising from a direct tbongh transi- tory union of the alcohol with the nervous substance. Richardson has made the very important discovery that the alcohols, such as the butyl, amyl, and hexyl alcohols, which contain more carbon, produce a much greater effect on the nervous system than methyl and ethyl alcohol. There are greater muscular tremors and stupor, and these effects increase regularly with the increase of carbon and lessening volatility. 31 G PRACTICAL HYGIENE. appearance of alcohol in the mine. These effects manifestly mark the entrance of that stage in the gi-eater degrees of which the poisonous effect of alcohol becomes manifest to all. It may be considered, then, that the limit of the useful effect is pro- duced by some quantity between 1 and 1^ fluid ounce in twenty-four hours. There may be persons whose bodies can dispose of larger quantities ; but as the experiments were made on two powerful, healthy men, accustomed to take alcohol, the average amount was more hkely to be over than under stated. In women, the amount requu'ed to produce decided bad effects must, in all probability, be less. For children there is an almost univer- sal consent that alcohol is injurious, and the very small quantity which produces symptoms of intoxication in them indicates that they absorb it rapidly and tolerate it badly. Assuming the correctness of these experimental data, v/hich, though not extensive, are yet apparently exact, it is evident that moderation must be something below the quantities mentioned ; and considering the dan- gers of taking excess of alcohol, it seems wisest to assume 1 to 1^ fluid ounce of absolute alcohol in twenty-four hours as the maximum amount which a healthy man should take. It must be admitted that this is pro- visional, and that more experiments are necessary ; but it is based on the only safe data we possess. One ounce is equivalent to 2 fluid ounces of brandy (containing 50 per cent, of alcohol) or to 5 ounces of the strong wines (sherries, etc., 20 per cent, of alcohol) ; or to 10 ounces of the weaker wines (clarets and hocks, 10 per cent, of alcohol) ; or to 20 ouiices of beer (5 -per cent, of alcohol). If these quantities are increased one-half, 1-^ ounce of absolute alcohol will be taken, and the Umit of moderation for strong men is reached. This standard appears to be fairly correct ; since, from inquuies of many healthy men w^ho take alcohol in moderation. Dr. Parkes found that they seldom exceeded the above amounts. Women, no doubt, ought to take less ; and alcohol in any shape only does harm to healthy children. Another question now arises, to which it is more difficult to reply. Is alcohol, even in this moderate amount, necessary or desii-able ; are men really better and more vigorous, and longer lived with it than they would be without any alcohol ? If distinctly hurtful in large quantities, is it not so in these smaller amounts? There is no difficulty in proving, statistically, the vast loss of health and life caused by intemperance ; and the remai'kable facts of the Provi- dent Institution show the gTeat advantage total abstainers have over those who, though not intemperate, use alcohol more freely. But it is almost impossible, at present, to compare the health of teetotallers with those who use alcohol in the moderate scale given above. In both classes are found men in the highest health, and with the gi-eatest vigor of mind and body ; in both are to be found men of the most advanced age. If the question is looked at simply as a scientific one, it is hardly possible at present to give an answer. Failing in accui-ate information on this point, the usual argu- ments for and against the use of alcohol cannot be held to settle the point. These are — (a) That the universality of the habit of using some intoxicating drink proves utility. This seems incorrect,' since whole nations (Mohammedan and Hindoo) use no alcohol or substitute ; and since the same argument ' Most nations, however, if not all, use some sedative, which may be considered to take the place of alcohol. — (F. de C.) BEVERAGES AND CONDIMENTS. 317 miglit prove the necessity of tobacco, which for this generation, at any rate, is clearly only a luxury. The wide-spread habit of taking intoxicat- ing liquids nierel}^ proves that they are pleasant. (6) That if not necessary in healthy modes of life, alcohol is so in our artificial stage of existence amid the pressure and conflict of modem so- ciety. This argument is very questionable, for some of our hardest work- ers and thinkers take no alcohol. There are also thousands of persons engaged in the most anxious and incessant occupations who are total ab- stainers, and, according to their own account, with decided benefit. (c) That though it may not be nec^sary for perfectly healthy persons, alcohol is so for the large class of people who live on the confines of health, whose digestion is feeble, circulation languid, and nervous system too excitable. It must be allowed there are some persons of this class who are benefited by alcohol in small quantities, and chiefly in the form of beer or Hght wine. Unless these persons wilfully deceive themselves, they feel better and are better with a httle alcohol. (d) That common experience on the largest scale shows that alcohol in not excessive quantities cannot be an agent of harm ; that it is and has been used by millions of persons who aj)pear to suffer no injuiy, but to be in many cases benefited, and therefore that it must be in some way a valu- able adjunct to food. A grand fact of this kind must, it is contended, override all objections based on j)hysiological data, which are confessedly incomplete, and which may have left undiscovered some special useful action. It must be admitted that this is a very strong argument, and that it seems incredible that a large part of the human race should have fallen into an error so gigantic as that of attributing great dietetic value to an agent which is of httle use in small quantities, and is hurtful in large. At first sight the common sense of mankind rcA^olts at such a supposition, but the argument, though strong, is not conclusive ; and unfortunately we know that in human affau's no extension of behef, however wide, is per se evidence of truth. (e) That though a man can do without alcohol under ordinary circum- stances, there are certain conditions when it is useful. It will be necessary to see, then, what is the evidence on this point. Evidence on the Use of Alcohol under certain Conditions.^ Great Cold. — There is singular unanimity of opinion on this point ; all observers condemn the use of spii'its, and even of wine or beer, as a pre- ventive against cold. In the Arctic regions we have on this head the evi- dence of Sir John Richardson, Mr. Goodsir (in Sir J. Franklin's first voy- age), Dr. Iving, Captain Kennedy (in the last search for Su' J. Franklin, when the whole crew were teetotallei's), Dr. Eae, Dr. Kane, Dr. Hayes (sur- geon of the Kane expedition), and others. Dr. Hayes, indeed, says in his last paper (1859), that he will not only not use spirits, but will take no man accustomed to use them; and that if "imperious necessity obhges him to give spirits, he vrill give them in small doses frequently, as the ex- citant action is followed by a very dangerous depression.^ In the Antarc- ' See Carpenter's " Essay on Temperance," and his other -writings, and also Spencer Thompson's useful work on the same subject, as well as many other writers. ^ Some Arctic voyagers, however, are strongly impressed with the value of rum under certain circumstances (Admiral Richards'. The experience of the expedition of 1875-76 seems to have shown that it was partially useful given the last thing at night, as enabling the men to get off their frozen clothing, but it had no effect in warding off scurvy. Binz says that alcohol may be useful in damp and cold, because the tissue change is greater, and we can thus moderate it. 318 TRACTICAL IIYGIEXE. tic regions, aud in the cold whaling grounds, we have the strong e^•idence of Dr. Hooker to the same purport, and the customs of the many teetotal whalei-s. Ulloa long ago noticed the same thing in the ascent of Pichin- cha. ' In North America, the Hudson's Bay Company entirely excluded spirits, partly, no doubt, to prevent their use among the Indians, but partly, in all probability, from experience of theii- inutility. Dr. Carpenter quotes from Dr. Kniill a statement that the Russian army on the march in cold weather not only use no spirits, but no man who has lately taken any is allowed to march. The guides at Chamouni and the Oberland, when out in the winter, have invariably found spirits hurtful ; they take only a Httle light Arine (Forbes). The bathing men at Dieppe, who are much ex- posed to cold from long standing in the sea, also find that spirits are hurt- ful, and take only a little weak wine (Lca-}'). Great Heat. — The eridence here also is almost equally conclusive against the use of spirits or beverages containing much alcohoL Dr. Car- penter has assembled the most conclusive testimony from India, Brazil, Borneo, Afi-ica, and Demerara. The best authorities on tropical diseases speak as strongly ; Robert Jackson, Ranald Martin, Henn' Marshall, and many others. It seems quite certain, also, that not only is heat less well borne, but that insolation is predisposed to. The common notion that some form of alcoholic beverage is necessary in tropical climates is a mischievous delusion. In the 84th Regiment, in which Dr. Parkes formerly served, which from the yeai-s 1842 to 1850 numbered many teetotallers (at one time more than 400) in its ranks, the records showed that, both on common tropical service and on marches in India, the teetotallers were more healthy, more rigorous, and far better soldiers than those who did not abstain." The experience of almost every hunter in India will be in accordance with this. On this point the greatest army surgeons have spoken strongly (Jack- son especially, and Mai-tin) ; and yet ofiicers may still be heard, both in India and the West Indies, to assert that the climate requires alcohol. These are precisely the climates where alcohol is most hui-tful.^ With regard to senice and exercise in the tropics, we have the strong testimony of Ranald Martin that warm tea is the best beverage ; and this wiU be corroborated by every* one who has made long marches, or hunt- ing excursions, in India, and has carefully observed what kind of diet best suited him. To cite a well-known indiridual instance of great exertion in a hot climate, Robert Jackson marched 118 miles in Jamaica, carr\-ing a load equal to a soldier's, and decided that " the English soldier may be rendered capable of going through the severest military serrice in the West Indies ; and that temperance wiU be one of the best means of enabling him to per- ' He says (Adams' translation, 1807, vol. i., p. 219): "At first we imagined that drinking strong liquors would diffuse a heat through the body, and consequently ren- der it less sensible of the painful sharpness of the cold ; but to our surprise we felt no manner of strength in them, nor were they any greater preventative against the cold than common water." * See Carpenter's Physiology of Temperance for full details. The officers, who by their example and precept produced this great effect in a regiment in India, and proved that men are healthier and happier in India without any alcoholic beverage, were Lieut. -Colonel Willington, Captain (afterward General Sir David) Russell, and Lieut, aud Adjutant Seymour, an officer of the greatest promise, who died from dysen- tery, contracted during the mutiny. * Binz holds that in hot climates, or in hot weather, it is perniciouS; as interfering with the tissue change, which is already insufficient. BEVERAGES AND CONDIMENTS. 319 form his duty with safety and effect. The use of ardent spirits is not necessary to enable a European to undergo the fatigue of marching in a chmate whose mean temperature is fi-om 73° to 80°. I have always found the strongest Hquors the most enervating." Bodily Labor. — A small quantity of alcohol does not seem to produce much effect, but more than two fluid ounces manifestly lessens the power of sustained and strong muscular work. In the case of a man on whom Dr. Parkes experimented, 4 fluid ounces of brandy (=1.8 fluid ormce of abso- lute alcohol) did not apparently affect labor, though it could not be affirmed it did not do so ; but 4 ounces more given after four hours, when there must have been some elimination, lessened muscular force ; and a third 4 ounces, given four hours afterward, entirely destroyed the power of work. The reason was evidently twofold. There was, in the first place, narcosis and blunting of the nervous system — the will did not properly send its commands to the muscles, or the muscles did not respond to the will ; and secondly, the action of the heart was too much increased, and induced palpitation and breathlessness, which put a stop to labor. The inferences were, that even any amount of alcohol, although it did not produce symptoms of narcosis, would act injuriously by increasing unnecessarily the action of the heart, which the labor alone had sufficiently augmented. ^ These experiments are in accord with common experience, which shows that men engaged in very hard labor, as iron-puddlers, glass-blowers, nav- vies on piece-work, and prize-fighters during training, do their work more easily without alcohol. In the exhaustion following great fatigue, alcohol may be useful or hurtful according to circumstances. If exertion must be resumed, then the action of the heart can be increased by alcohol and more blood sent to the muscles ; of coiarse, this must be done at the expense of the heart's nutrition, but circumstances may demand this. In the case of an army, for example, called on to engage the enemy after a fatiguing march, alcohol might be invigorating. But the amount must be small, i.e., much short of producing narcosis (not more than |- fluid ounce of absolute alcohol), and, if possible, it should be mixed with Liebig's meat extract, which, perhaps on account of its potash salts, has a great power of remov- ing the sense of fatigue. About two ounces of red claret wine with two teaspoonfuls of Liebig's extract and half a pint of water is a very reviving draught, and if it could be issued to troops exhausted by fatigue, would prove a most useful ally. But when renewed exertion is not necessary it would appear most proper after great fatigue to let the heart and muscles recruit themselves 1 In experimenting on another healthy man the following interesting result was obtained. The exercise and diet being uniform during a period of ten days, the mean daily pulse (nine two hourly observations) was 70.65. Severe exercise being then taken during another period of ten days for two hours in the morning, in addition to what had previously been taken, the pulse in those two hours was augmented 16 beats per minute over the corresponding period ; it fell, however, in the subsequent hours below the mean of the corresponding period, so that the mean pulse of the day was 70.42 per minute, the same as in the ten days' period before the additional exercise. The heart, in fact, completely compensated itself, and the work done by it was the same on days of moderate and of severe exercise. Now alcohol would have disturbed this adjustment, and would have kept the heart beating more rapidly than it should do. The compensation would not have been produced. In more recent experiments, in which the eifects of rum, meat extract, and coffee were observed, it was found that marching was done least easily with rum, the stimulant effect passing quickly otf, and leaving the man less able to finish the work before him, — (On the Issue of a Spirit Ra- tion in the Ashantee Campaign, Parkes, 1875.) 320 PRACTICAL HYGIENE. by rest ; to gi\e digestible food, but to avoid unnecessary and probably hvu'tful quickening of the heart by alcohol. Mental Work.— In spite of much large experience, it is uncertain whether alcohol really increases mental power. The brain ciiTulation is no doubt augmented in rapidity ; the nervous tissues must receive more nutriment, and for a time must work more strongly. Ideas and images may be more plentifully produced, but it is a question whether the power of clear, consecutive, and continuous reasoning is not always lessened. In cases of great exhaustion of the nervous system, as when food has been withheld for many hoiu's and the mind begins to work feebly, alcohol re- vives mental power greatly, probably from the augmented circulation. But, on the whole, it seems questionable whether the brain finds in alcohol a food which by itself can aid in mental work. Deficiency of Food. — When there is want of food, it is generally con- sidered that alcohol has a sustaining force, and possibly it acts pai'tly by keeping up the action of the heart, and partly by deadening the suscepti- bihty of the nerves. It was formerly sui:)posed that it lessened tissue -change, and thus cui-tailed the waste of the bod}- ; but this is not true of the nitro- genous tissues, and is not yet quite certain in respect of the carbonaceous. It seems unhkely that alcohol would be appHed differently dui'ing starvation and during usual feeding. Cases are recorded in which persons have Hved for long periods on almost nothing but wine and spuits. In. most cases, however, some food has been taken, and sometimes more than was supposed, and in all instances there has been great quietude of mind and body. It seems veiy doubtful whether in any case nothing but alcohol has been taken ; and, in fact, we may fairly demand more exact data before weight can be given to this statement. T'ue Exposures and Exertions of War. — On this point also there is con- siderable unanimity of opinion. The gi'eatest fatigues, both in hot and cold chmates, have been well boi-ne — have been, indeed, best borne — by men who took no alcohol in any shape, and some instances may be quoted. In the American "War of Independence in 1783, Lord CornwaUis made a march over 2,000 miles in Yii-ginia, under the most trying cii'cumstances of exposure to cold and wet ; yet the men were remarkably healthy, and among the causes for this health, Chisholm states that the necessaiy absti- nence from strong Hquors was one. In 1794-95 occurred the Maroon War in Jamaica, where almost forthe first time in West Indian warfare the troops were remarkably healthy, though the campaign was very arduous, and in the rainy season, and there were no tents. The perfect health of the troops may pai-tly have been owing to the climate of the hills (2,000 feet above the sea), but it was chiefly attributed to the fact that the men could obtain no spirits or alcohoHc liquid of any kind. In 1800 an English army proceeding from India to Egyj)t, to join Sir Ralph Abercromby, marched across the desert, fi-om Kossier on the Red Sea, and descended the Nile for 400 miles. Sir James M'Grigor ' says that the fatigue in this march has perhaps never been exceeded by any army, and goes on to remai-k : — " We received still further confirmation of the very great influence which intemperance has as a cause of disease. We had demonstration how verj' ' Medical Sketches of the Expedition to Egypt, p. 10. BEVERAGES AND CONDIMENTS. 321 little spirits are required in a liot climate to enable a soldier to bear fatigue, and liow necessary a regular diet is. " At Ghenne, and on the voyage down the Nile (on account of the dif- ficulties of at first conveying it across the desert), the men had no spirits deUvered out to them, and I am convinced that from this not only did they not suffer, but that it even contributed to the uncommon degree of health which they at this time enjoyed. From two boats the soldiers one day strayed into a village, where the Arabs gave them as much of the spirit which they distil from the juice of the date-tree as induced a kind of furious delirium. It was remarked that, for three months after, a considerable number of these men were in the hospitals." Dr. Mann,' one of the few American surgeons in the war of 1813-14 who have left any account of that contest, thus writes : — " My opinion has long been that ardent spirits are an unnecessary part of a ration. Examples may be furnished to demonstrate that ardent spirits are a useless part of a soldier's ration. At those periods during the revo- lutionary war, when the army received no pay for their services, and pos- sessed not the means to procure spirits, it was healthy. The 4th Massachu- setts Regiment, at the eventful period when I was the surgeon, lost in three years by sickness not more than five or six men. It was at a time when the army was destitute of money. During the winter 1779-80 there was only one occurrence of fever in the regiment, and that was a pneumonia of a mild form. It was observable in the last war, from December, 1814, to April, 1815, the soldiers at Plattsburg were not attacked with fevers as they had been the preceding winters. The troops during this period were not paid — a fortiraate circumstance to the army, arising from want of funds. This embarrassment, which was considered a national calamity, proved a blessing to the soldier. When he is found poor in money, it is always the case that he abounds in health — a fact worth recording." No testimony can be stronger than that given by the late Inspector- General Sir John Hall, K.C.B. He says ' : — " My opinion is, that neither spirit, wine, nor malt liquor is necessary for health. The healthiest army I ever served with had not a single drop of any of them ; and although it was exposed to all the hardships of Kaffir warfare at the Cape of Good Hope, in wet and inclement weather, without tents or shelter of any kind, the sick-list seldom exceeded one per cent. ; and this continued not only throughout the whole of the active operations in the field during the campaign, but after the men were collected in stand- ing camps at its termination ; and this favorable state of things continued until the termination of the war. But immediately the men were again quartered in towns and fixed posts, where they had free access to spirits, an inferior species of brandy sold there, technically called ' Cape Smoke,' num- erous complaints made their ajopearance among them. " In Kaffraria the troops were so placed that they had no means of ob- taining liquor of any kind ; and all attempts of the ' Winklers' to infringe the police regulations were so summarily and heavily punished by fines and expulsion, that the illicit trade was effectually suppressed by Colonel Mac- kinnon, the Commandant of British Kaffraria ; and the consequence was, that drunkenness, disease, crime, and insubordination were unknown ; and yet that army was frequently placed in the very position that the advocates for the issue of spirits would ha\'e said required a dram. ^ Hamilton, Military Surgery, p. 61. ^ Medical History ot the War in the Crimea, vol. i. , p. 504, Vol. I.— 31 322 PEACTICAL HYGIENE. " Small as the amount of sickness and mortality was in the Crimea, dur- ing the winter 1855-56, they wovdd have been reduced one-half, I am quite sure, could the rule that was observed in Kaffirland have been enforced there." In the same Kafl^ war (1852), a march was made by 200 men from Graham's Town to Bloemfontein, and back ; 1,000 miles were covered in seventy-one days, or at the rate of nearly 15 miles daily ; the men were almost naked, were exposed to great variations of temperatiu-e (excessive heat dui'ing day ; while at night water froze in a bell-tent, with twenty-one men sleeping in it) ; and got as rations only biscuit, meat l^ft, and what game they could kill. For drink they had nothing but water. Yet this rapid and laborious march was not only perfoi-med easily, but the men were " more healthy than they had ever been before ; and after the first few days, ceased to care about spirits. No man was sick till the end of the march, when two men got dysentery, and these were the only two who had the chance of getting any hquor." In the last New Zealand war. Dr. Neill (Staff Assistant-Surgeon) found that the troops marched better, even when exposed to wet and cold, when no spirits were issued, than when there was a spirit ration. In the expedition to the Ked Eiver, under Sir Garnet Wolseley, no alco- hoHc liquid was issued. Two accounts of this remarkable march have been published — one by Captain Huyshe, ' and the other by an officer who wrote an interesting account of the mai'ch in Blackwood's Magazine."^ Captain Huyshe says : — " Although it was an unheard-of thing to send off an expedition into a wilderness for five months without any spirits, still as the backwoodsman was able to do haixl work without spirits, it was rightly thought that the British soldiers could do the same. The men Avere allowed a lai-ge daily ration of tea, 1 oz. per man — practically as much as they could di-ink ; and, as I am now on this subject of bohea versus grog, I may as well state that the experiment was most successful. The men of no previous expedition have ever been called upon to perform harder or more continuous labor for over four months. . . . They were always cheeiy, and worked with a zealous will that could not be sm-passed. This expedition would have been a bright era in our military annals had it no other result than that of proring the fallacy hitherto beHeved in of the necessity of proriding our men when in the field with intoxicating liquors." The writer in Blackwood's Magazine says : — "The men were pictures of good health and soldier-like condition whilst stationed at Prince Arthur's Landing and the other larger camps. The men had fresh meat, bread, and jjotatoes every day. No spirits were allowed throughout the journey to Fort GaiTy, but all ranks had daily a largQ ration of tea. This was one of the very few miHtary expeditions ever undertaken by English troops where intoxicating liquors formed no pari of the daily ration. It was an experiment based upon the practice common in Canada, where the lumbermen, who spend the whole winter in the back- woods, employed upon the hardest labor, and exposed to a freezing tem- perature, are allowed no spirits, but have an unlimited quantity of tea. Our old-fashioned generals accept, without any attempt to question its tnith, the traditional theory of rum being essential to keep the British soldier in health and humor. Let us hope that the experience we have ' Journal, United Service Institution, 1871, vol. xv.,p. 74. * January, 1871, p. 64. BEVERAGES AND CONDIMENTS. 323 acquired during the Eed River expedition may have buried for ever this old-fogyish superstition. Never have the soldiers of any nation been called upon to perform more unceasingly hard work, and it may be confidently asserted without dread of contradiction, that no men have ever been more cheerful or better behaved in every respect. No spirit ration means no crime ; and even the doctors who anticipated serious illness from the absence of liquor, will allow that no troops have ever been healthier than they were from the beginning to the end of the operation. With the ex- ception of slight cases of dian-hoea, arising from change of diet, it may be said that sickness was unknown amongst us." Sir Garnet Wolseley,' who commanded in this remarkable expedition, speaks very strongly against the rum ration, and says that, by substituting tea for rum, the health and efficiency of the men are increased, " their dis- cipline will improve as their moral tone is raised, engendering a manly cheerfulness that spii-it-drinking armies know nothing of." In the Ashantee campaign of 1874 observations were carefully recorded by several officers." The conclusions arrived at were— 1. That abstinence did not render those who abstained more sickly as a whole or more liable to malarious fever ; nor did it interfere with their powers of marching. 2. The issue of a ration of rum seemed to do good when given at the end of the day before going to rest. 3. That the quantity (2^ oz.) was amply sufficient. On the whole the necessity for the ration was by ho means proved, although some officers returned rather shaken in their previous behef that alcohol was absolutely unnecessary in a military expedition. In sieges, which are perhaps more trying to men than campaigning in the open field, the advantage of temperance has, on two occasions, been very marked. In the great siege of Gibraltar, Sir George Eliott, who was a teetotaller, enforced the most rigid temperance, and the long and arduous blockade was passed through T\ith remarkably little sickness. At the siege of Jellalabad, in Afghanistan, the " illustrious ganison were quite destitute of all alcohoHc Hquors ; and, to the astonishment of the officers, the Europe- ans never had been so healthy, cheerful, martial, and enduring and free from crime. During the Indian mutiny many regiments were debaiTcd from spirits for a long time, and were much healthier than when they got them. In fact, it may be confidently asserted that in "v\'ar, spirits especially, and indeed aU alcohoHc liquors, are better avoided ; and the phrase of an American army surgeon in the civil war, who noticed how great was the improvement when spirit prohibition was enforced, is fully justffied by oru* cvsTi experience — " The curse of an army is intoxicating hquors ; the spirit ration is the source of all this mischief." When debaiTed from spirits and fermented liquids, men are not only better behaved, but are far more cheerful, are less iiTitable, and endure better the hardships and perils of war. The courage and endiu-ance of a drunkard are always lessened ; but in a degree far short of di-unkenness, spirits lower, while temperance raises, the boldness and cheerfulness of spirit which a true soldier should possess.' ' Soldiers' Pocket Book, 2d edition, p. 172. 2 On the Issue of a Spirit Ration during the Ashantee Campaign of 1874 (Parkes). ^ The custona of giving rations of spirits to soldiers and sailors (even now not alto- gether discontinued), was one of those incredible mistakes which are only made worse by the explanation that it was done to please the men, and cover neglect in other ways. If any one wishes to see what our army was in former days, and how dreadful military regulations made men drunkards in spite of themselves, they may refer to an old 324 PRACTICAL HYGIENE. Looking back to this evidence, it may be asked, Are there any circum- stances of the soldier's life in which the issue of spmts is advisable, and if the qiiestion at any time hes between the issue of spirits and total abstinence, which is the best ? There seems but one answer. If spirits neither give strength to the body, nor sustain it against disease — are not protective against cold and wet, andaggravate rather than mitigate the effects of heat — if their use even in moderation increase crime, injure discipline, and impair hope and cheer- fulness — if the severest trials of war have been not merely borne, but most easily borne, Avithout them — if there is no evidence that they are protective against malaria or other diseases — then the medical officer will not be jus- tified in sanctioning their issue under any circumstances. The terrible system which in the East and West Indies made men drunkards in spite of themselves, and which by the issue of the morning dram did more than anything else to shatter the constitutions of the young soldiers, is now becoming a thing of the past. But the soldier is still per- mitted to get spirits too easily, and is too ignorant of their fatal influence on his health. Still the British army bears the unhappy character of the most intemperate army in Europe, and it is ceiiain that its moments of misconduct and misfortune have been too frequently caused by the unre- strainable passion for drink. Kemembering all these things, and how certainly it has been proved that dmnkenness increases the spread of syph- ilis, it is not too much to say that the repression of this vice should be one of the chief duties of every officer in the army. Moderation should be encouraged by precept and example ; wholesome beer and hght wine should Peninsular surgeon's (William Fergusson's) Notes and Recollections of a Professional Life (1846). "During the last war" (he says, p. 74), " our sailors and soldiers appeared to live for the purpose of getting drunk ; with them it seemed to be the chief article of their creed— the chief end of life. . . . 'Grog, grog,' was still the cry ; I have seen it, as it were, forced down the throats of the innocent negro boy and the uncorrupted young recruit. We seemed to believe that the term aqua tit(P was its true designation. Every one was to have it ; no matter what the age, the color, the country, or the breed- ing. Our Portuguese allies in the Peninsula were the soberest of mankind. Ihey liked their own weak country wine to dilute their food, but that would not do for us. We actually sent for the rum of the West Indies and gave it them ; and at the battle of Busaco, I saw a party of Portuguese artillery, as soon as the rum ration was served, as if they had been possessed by a devil (and they actually were possessed by a devil in the shape of alcohol), draw their SAVords and fight with one another, when actually under the fire of the enemy " (p. 85). He cites numerous most lamentable facts, and well concludes that "our canteen system will in after-times be viewed with horror and astonishment, at its folly, corrup- tion, and wickedness." These opinions are not recalled without a motive. There is too much reason to fear that many officers still believe that soldiers must have spirits. Fergusson says that "the exceeding vulgarity of the prejudice that ardent spirits impart strength and vigor to the human frame is disgraceful to educated men ; " and yet this belief is still actually held by persons in authority. Although in the army drinking is the great source of all crime and insubordination ; although even within late years we have had one if not more instances that, even during an assault, men will sacrifice anything, even their honor, to obtain spirits ; although the best oflicers know that this is the one point on which they cannot depend on their men, far too little has been done to make our army temperate. This does not mean that nothing has been done ; on the contrary, in this, as in all things, progress has been made, but the measures are not sufficient to control an evil so gigantic. It is the same thing in civil life ; there is no question that more disease is, directly and indirectly, produced by drunkenness than by any other cause, and that the moral as well as the physical evils proceeding from it are beyond all reckoning ; and yet the attempts of the Legislature to set some bounds to intem- perance have been and are opposed with a bitterness which could only be justified if the degradation and not the improvement of mankind was desired. BEVEEAGES AND CONDIMENTS. 325 be invariably substituted for spirits, and if these cannot be procured, it may safely be said that the use of tea, coffee, or simple water is preferable to spirits under all circumstances of the soldier's life. Eedstance to Disease. — Malaria. — There are instances for and against the view that spuits are useful against malaria. On both sides the evidence is defective ; but there are so many cases in which persons have been attacked with malarious disease who took spirits, that it is impossible to consider the preventive powers great, even if they exist at all. On the other hand, when teetotallers have escaped malaria (as in the instance recorded by Drake),' there have been other circumstances, such as more abundant food and better lodging, which will explain their exemption. The probability is, that the reception and action of malaria are not influenced by the presence or absence of alcohol in the blood unless the amount of alcohol is so great as to lessen the amount of food taken. Yelloio Fever. — It is a general opinion in New Orleans and Mobile that the victims of yellow fever are chiefly those who drink freely (Drake). The old West Indian experience is to the same eftect. Cholera. — Intemperance, per se, has no influence, and teetotaUsm does not guard against cholera. When a regiment is attacked with cholera, and the men take to drinking, a number of pseudo-cases come into hospital of vomiting and cramps, which are often returned as cholera, but they seldom if ever pass into true cholera. Dysentery. — It has been supposed, from some statistics for 1847, pub- lished in the Fort George Gazette, that teetotallers were more subject to dysentery, but the error was committed of not estimating sufficiently the influence of a particular station (Secunderabad), where it so happened a number of teetotallers were stationed during an outbreak of dysentery. The conditions of the station were to blame, not the habits of the men. In none of the conditions now enumerated is there any evidence that alcohol is desirable. Conclusion as to the Use of Alcohol. The facts now stated make it difficult to avoid the conclusion that the dietetic value of alcohol has been much over-rated. It does not appear possible at present to condemn alcohol altogether as an article of diet in health ; or to prove that it is invariably hui'tf ul, as some have attempted to do. It produces effects which are often useful in disease and sometimes desirable in health, but in health it is certainly not a necessity, and many persons are much better without it. As now used by mankind (at least in our own, and in many other countries), it is infinitely more powerful for evil than for good ; and though it can hardly be imagined that its dietetic use will cease in oar time, yet a clearer view of its effects must surely lead to a lessening of the excessive use which now prevails. As a matter of public health, it is most important that the medical profession should throw its great influence into the scale of moderation ; should explain the limit of the useful power, and show how easily the line is passed which carries us from the region of safety into danger, when alcohol is taken as a common article of food.^ ^ On the Interior Valley of North America. ^ A great evil is growing iip in India, which now could be checked, but which we shall be powerless to meet in a few years. The Hindoos, formerly the most temperate oE races, are rapidly becoming addicted to drink. This is said to be partly owing to the regulations of the Government permitting, and even encouraging the sale of spirits, 326 PRACTICAL HYGIENE. Dietetic Use of Alcoholic Beverages. In the previous remarks, the effect of alcohol only has been discussed, but beer and wine contain other substances besides Jilcohol. In wine there are some albuminous substances, much sugar (in some wines), and other carbo-hydrates, and abundant salts. Whether it is that the amount of alcohol is small, or whether the alcohol be itself, in some way, different from that prepared by distillation,' or whether the coexistence of carbo-hydrates and of salts modifies its action, certain it is that the moderate use of wdne, which is not too rich in alcohol, does not seem to lead to those profound alterations of the molecular constitution of organs which follow the use of sj^irits, even when not taken largely. Considering the large amounts of vegetable salts which most wines contain, it may reasonably be supposed that they play no unimportant part in giving dietetic value to wine. Indeed, it is quite certain that, in one point of view, they are most valuable ; they are highly anti-scorbutic, and the arguments of Lind and Gillespie, for the introduction of red wine into the royal navy instead of spirits, have been completely justified in our own time by both French and English experience. It is now certain that with the same diet, but giving in one case red wine, in another rum, the persons on the latter system will become scorbutic long before those w^ho take the wine. This is a most imj^ortant fact, and in a campaign the issue of red wines should never be omitted. The ethers may also be important if, as indicated by Bernard, and I'eceutly j^ointed out by Dr. B. Forster," they excite the flow of the pancreatic secretion, and thereby promote the absorption of fat. In beer there api:)ear to be four ingredients of importance, viz., the ex- tractive matters and sugar, the bitter matters, the free acids, and the alcohol. The first, no doubt, ai'e carbo-hydrates, and play the same part in the system as starch and sugar, appropriating the oxygen, and savmg fat and albuminates from destruction. Hence, one cause of the tendency of jDersons who drink much beer to get fat. The bitter matters are sui:)posed to be stomachic and tonic ; though it may be questioned whether we have not gone too far in this direction, as many of the highest-priced beers contain now little else than alcohol and bitter extract. The action of the free acids is not known ; but their amount is not inconsiderable ; and they are mostly of the kind which form carbonates in the system, and which seem to jilay so useful a part. The salts, especially potassium and magnesium phosphates, are in large amount. It is e\ddent that in beer we have a beverage which can answer several purposes, viz., can give a supply of carbo-hydrates, of acid, of important salts, and of a bitter tonic (if such be needed) independent of its alcohol, but whether it is not a very expensive way of giving these substances is a question. In moderation, it is no doubt well adapted to aid digestion, and to lessen to some extent the elimination of fat. It may be infeixed that beer wUl cause an increase of weight of the body, by increasing the amount of although the alcoholic liquors form no part of the ordinary food of the people, and there- fore their prohibition is not difficult ; and partly from the bad example of the Europeans in India, who, as the dominant race, are impressing more and more the nations whom they control. It seems a matter which our statesmen may well look into, for it involves the happiness of many nations. ' Thudichum and Dupre could not, however, trace any difference between the alcohol in wines and that derived from other sources. •■^ Brit. Med. Journal, November, 1868. BEVERAGES AND CONDIMENTS. 327 food taken in, and by slightly lessening metamorpliosis ; and general experience confirms those inferences. When taken in excess, it seems to give rise to gouty affections more readily even than wine. In spirits, alcohol is the main ingi'edient, chiefly in the form of ethyl- alcohol, though there are small amounts of propyl-, butyl-, and in some cases amyl-alcohols. In addition, there are sometimes small quantities of ether ; and, in some cases, essential oils (as apparently in absinthe, and in one kind of Cape brandy), which have a powerful action on the nerves. But spirits are, for the most part, merely flavored alcohol, and do not con- tain the ingredients which give dietetic value to wine and beer. They are also more dangerous, because it is so easy to take them undiluted, and thus to increase the chance of damaging the structure and nutrition of the albuminous structures with which they come first in contact. There is every reason, therefore, to discourage the use of spirits, and to let beei^ and wines, with moderate alcohoUc power, take their place. SECTION n. NON-ALCOHOLIC BEVERAGES. Sub-Section L — Coffee. Unroasted coffee contains much cellulose (34 per cent.), fat (10 to 13 per cent.), sugar and dextrin, and vegetable acid (15.5), and legumin (10 per cent. ). There is also a solid acid, aromatic oil in small quantities, caffein, and ash, the chief ingredients of which are potash and phosphoric acid. The total amount of caffein (free and combined), according to Payen, is about 1.736 per cent. ; but this is more than other observers have found. In roasted coffee berries the average of Boutron and Eobiquet's analyses gives .238 per cent, of caffein. Aubert' has given the amount as from .709 to .849 per cent., and Witte makes it .666 per cent. ; Graham, Sten- house, and Campbell state it as .87 per cent. It may be assumed to be .75 per cent, on an average. Aubert found that roasting coffee to any extent caused very little loss of caffein. The caffein is extracted easily by benzol or by chloroform.^ When coffee is roasted it swells, but becomes lighter (15 to even 25 per cent., if the coffee is dark roasted). The sugar is changed into caramel, the peculiar aroma is developed, the union between the caffein and the caffeo-tannic acid is broken up ; several gases are formed, viz., carbon dioxide (in gTeatest amount), carbon monoxide, and nitrogen. It is owing to these gases that the roasted coffee swells so much.^ In the infusion almost all the caffein is found, according to Aubert, whUe others say about one-half is lost. Aubert has found that in a cup of coffee made with 16.66 grammes, or .587 ounce avoirdupois (1 Prussian loth), there aro ^ Arctiv. fiir die ges. Phys. , Band v., p. 589. * CaSein and thein are the same substance. Theobromine belongs to the same series, and has apparently identical effects. In the leaves of the Paraguay tea {Ilex paraguayensis, the tea is called Mate in Paraguay), which are used to make tea in the Argentine confederation, and throughout the southern part of Brazil, there is also an alkaloid identical with thein. In dietetic properties, Paraguay tea is thought to stand between coffee and Chinese tea, but to be more like coffee. The alkaloid in guarana is also thein, according to Stenhouse. 3 Coulier, Recueil de M^moires de Med. Mil., Juin, 1864, p. 508. 828 PRACTICAL HYGIET^-E. from .1 to .12 gramme ( = 1.5 to 1.9 grain of caffein). In a cup of tea made from 5 to 6 gi-ammes (= 77 to 92 grains) of tea, about the same amount of caffein is contained. As an article of diet, coffee stimulates the nervous system, and in large doses produces tremors. Caffein given to animals augments reflex action, and may produce tetanus, or peculiar stiffness of muscles. It increases the frequency of the pulse in men, and removes the sensation of com- mencing fatigue during exercise. It has been said (J. Lehmann and others) to lessen the amount of urea and phosphoric acid, but this is doubtful. ' It appears, however, to increase the m-inary water. The pul- monary carbon dioxide is said to be increased (E. Smith). It increases the action of the skin. In animals (frogs, dogs, and rabbits) caffein produced the following ▼effects, as determined by Aubei-t and others : — Inci-eased reflex action ; a . peculiar stiffness of the muscles, sometimes tetanus ; no lessening of ner- vous excitability ; an invariable increase in pulse-frequency, and a lessening of the blood-pressure (in dogs). This effect on the cu-culation is peculiar and complex. Aubert is conrinced that the work of the heart is less, in spite of the increased beats ; there is not time for perfect contraction, and this lessened power shows itself, he thinks, in the lessened blood-pressure. Aubert considers that the lessened heart-pressure is deiDendent on a moi-e or less marked paralysis of the nein-es passing to the heart from the gangha ; the increased frequency must be dependent either on paralysis of the regulating or excitation of the contractive heart nei-ves, and of this alternative he adoj^ts the latter. He thinks it uncertain whether coffee owes its dietetic vidue to the caffein. Coffee is a most important article of diet for soldiers," as not only is it invigorating, without producing subsequent collapse, but the hot infusion is almost equally serviceable against both cold and heat : in the one case, the w\armth of " the infusion, in* the other, the action on the skin, being useful, while in both cases the nei-vous stimulation is veiy desii-able. Dr. Hooker tells us that in the Antarctic expedition the men all pre- ferred coffee to spu'its, and this was the case in the Schleswig-Holstein war of 1849. The experience of Algeria and India (where coffee is coming more and more into use) proves its use in hot climates. It has been asserted to be protective against malaria. The eridence is not strong, but still is svifficient to authoi-ize its use in malarious districts. Making of Coffee. — Roasted and ground coffee must be served out to troops, as the delicate operation of roasting can never be performed by soldiers. Exposed to the ah', the roasted and ground coffee loses its aroma in from two to four months ; but if packed in tins, it will keep it for several months. The tins should not be too large, so that no more * While Hoppe found a decrease in dogs, Voit found no alteration of urea ; and some very careful experiments, made by Dr. Squarey of University College, do not confirm Lehmann's observations on men so far as the iirea is concerned. Dr. Squarey's experiments are far more complete than those of Lehmann ; the urea was not affected even by very large quantities of coffee. It would be interesting to examine the urine again after 'the use of the Erythroxylon coca. The late work of M. Moreno of Maiz (Paris, 1868) confirms the previous statements of the removal of the sensation of hun- ger by this substance. The cold infusion increases, he affirms, the arterial tension. Dr. Ldmonstone Charles has lately called attention to its power of preventing thirst. ■ The ration, one ounce, is generally too small, and might advantageously be doubled at least. See experiments recorded in The Issue of a Spirit Ration (Farkes,^, Appendix I., p. 39 et seq. BEVEEAGES AND CONDIMENTS. than necessary may be exposed to the air. It has been said that the tin is acted upon, but this does not appear to be the case for some time. The amount should be at least y\ths of an ounce for each person per meai Pig. 5f5. — Testa of Raw Coffee, x 170 , the ns^ht hand figure shows the double spiral fibres in the raphe of the berry, x 50U. The coffee must not be boiled, or the aroma is in part dissipated ; but if made with water of 180^ or 200^, the coifee only gives u]d 19 to 25 par cent., whereas it ought to yield 30 to 35 per cent. In order to get the fuU benefit of the coffee, therefore, after the infu- sion has been poured off, the grounds should be well boiled in some more water, and the hot de- coction poured over fresh coffee, so that it may take up aroma ; the coffee thus partially exhausted can be used on the next occasion for boiling. The infusion of coffee has a specific gravity of about 1008 to 1010 ; the oil, caffein, sugar, dex- trin, and mineral matters are taken up by water. Choice of Coifee. — This is de- termined entirely by the aroma and taste of the roasted coffee and of the infusion. Fig, 57. — Raw Coffee-berry; transverse section, If the coffee has been 330 PRACTICAL HYGIENE. damaged (as by sea-wafer, -wlien the berries are washed in fresh water and redried), there is always a disagreeable taste even after roasting Fig. 58.— Roasted Coffee ; the dark cells, containing air, Bhow the spiral fibre. (Chevallier). The berries give up less than Fig. 59. — Eoa=ted Coffee-berry ; transverpe section. usual to water (twelve per cent.).' Adulterations. — The mi- croscope detects adiiltera- tions with the greatest fa- cility. The structure of the cof- fee-beriy is shown in the di'awings. The long cells of the testa (Figs. 5G and 58) are very marked. The interior of the berrv' also presents charac- ters which are quite erident ; an iiTCgular areolar tissue contains light or dark yellow angular masses and oil glob- ules, which are very difl'er- ent from any adulterations. The little corkscrew-hke un- rolled spiral fibres are chiefly found in the bottom of the raphe. The usual adultera- ' With regard to the choice of the coffee berrv some caution must he used. The best coffee, that of Yemaii, originally the Abyssinian berry, is a moderately large iv\\ berry (according to Palgrave), the inferior sorts being small and shrivelled. In India the same rule does not seem to hold good, and I have been told by officers of expeii- BEVERAGES AND CONDIMENTS. 831 tions of coffee are roasted chiccory, ' cereal grains or beans, potatoes, and sugar. 1, Chiccory is discovered by its smell ; by yielding a darker and denser infusion of a specific gravity of 1018 to 1020 ; and by its niicroscoj)ic characters. It also sinks at once in water when roasted, whereas coffee floats for a long time, in consequence of the develojDment of gas during roasting, or from the non-absorbent character of the perisperm and hard yellow granules of the cellulose. The microscopic test is the most impor- tant, and both the cells and dotted ducts of chiccory are quite characteristic, at least nothing Like them exists in coffee.^ The percentage of ash has been suggested as a means of detection. Coffee yields about 4 jDer cent., of which four-fifths are soluble in water : chiccory yields about 5 per cent., of which only one-third is soluble. Chiccory contains a notable amount of sugar (12 to 14 per cent), whereas coffee never has more than 1 per cent. Wanklyn has proposed to make this a basis of detection, using the standard copper solution. Fig. 60. — Chiccory Root ; cells and dotted ducts. 2. Roasted corn or beans are at once known by the starch-grains, which frequently preserve the precise character of wheat or barley or beans. Iodine turns them at once blue. The infusion also gives a blue with iodine. 3. Potato starch is also at once detected ; there is nothing like it in coffee. Sago starch, which is sometimes used, is easily detected. 4. Sugar is detected by solution, and by the copper solution which it reduces, as the kind of sugar is almost always glucose. If caramel or burnt sugar be present, make an infusion, evaporate, dry, and taste ; if the ex- ence that in that country the best coffee is often a shrivelled and uninviting-looking article, whilst the fuller and apparently finer samples are really inferior for use as a beverage — (F. de C.) ' Chiccory is itself adulterated with roasted barley and wheat grain, acorns, mangold- wurzel, saw dust, and beans and peas. ^ Various vegetable substances are now permitted to be sold as substitutes for coffee, provided they are properly labelled and made up in ^ lb packets. 332 PRACTICAL HYGIENE. tract be brittle, dai'k colored, and bitter to the taste, caramel has been added (Hassall). 5. Pereii'a' has given a long list of adulterations of chiccory, and HassaU, has also detected mixture with mangold-wurzel, parsnij), carrot, acorn, and saw-dust. The cells of mangold-wurzel are like chiccory, but much larger ; those of caiTot and parsnip are something like chiccoiy, but contain starch- cells ; the stai'ch-grains of the acorn are round or oval, with a deep cul- vert depression, or hilum. The infusion of chiccory is not turned blue by iodine ; when incinerated the ash of chiccory shoiild not be less than 6 per cent. 6. Kecently date-stones gi-ound have been mixed with coffae and chic- cory, and sold as date coffee. They can be detected by the microscope, which shows numerous sclerogen cells. ^ Sub-Section II. — Tea. The chief kinds of black tea are Souchong, Congou, Oolong, and Pekoe. Bohea is not now found in the market. The chief green teas ai-e Hyson, Hyson-stem, Twankay, Caper, and Gunpowder. Dry tea contains about 1.8 per cent, of thein, 2.6 of albumen, 9.7 of dextrin, 22 of cellulose, 15 of tannin, 20 of extractives, 5.4 of ash, as well as other matters, such as oil, wax, and resin. In some good teas the amount of thein is much greater. PeHgot found as much as 6.21 per cent, in dry tea. The thein is combined with tannic acid. Black tea contains from 6 to 10 per cent, of water — more often the latter quantity ; gi'een tea about 8 per cent. The ash^ consists piincipally of potash, soda, magnesia, phosphoric acid, chlorine, carbonic acid, iron, and silica. There is rather more tannic acid, and more thein and ethereal oil, in gi-een than black tea, and less cellulose : otherwise the composition is much the same (Mulder). Black tea jields to boiling water 29-45 per cent. As a mean 38 " Green 40-48 As a mean 43 " About 4ths of the soluble matters are taken up by the first infusion with hot water. ^ If water contain much Hme or iron, it will not make good tea ; in each case the water should be well boiled \dth. a little carbonate of soda for 15 or 20 minutes, and then poured on the leaves. In the infusion are found dextiin, glucose, tannin, and thein. About 47 per cent, of the nitrogenous substances pass into the infusion, and 53 ' Materia Medica, vol. ii., p. 1578 (1863). ^ Analysis and Adulteration of Foods, by James Bell, 1881. * The Society of Public Analysts have adopted 8 per cent, of ash as the maximum of perfectly dry tea. The amount in ordinary tea is about 5 to 6 per cent., of whicli about 3 per cent, is soluble. The ash of spent tea is only about 3 per cent., of which 0. 5 is soluble. •* There appears now to be very little green tea in the market, since it has been de- cided that "facing" is an adulteration. = The Society of Public Analysts have adopted 30 per cent, as the minimum ex- tract in genuine tea ; Wauklyn takes 32, and certainly good genuine tea yields this at least. BEVERAGES AND CONDIME^^TS. 833 per cent, remain undissolved. If soda is added, a still greater amount is given to water. The green tea (now little sold) is either natural, or colored (faced) with indigo, Prussian blue, clay, carbonate and acetate of copper, curcuma, gypsum, and chalk. Scraping the tea-leaves and microscopic examination at once detect the shining blue jDarticles of indigo and Prussian blue ; and the addition of an acid indicates which is indigo. ^ Copper is at once detected by solution in an acid and addition of ammonia. Letheby stated that black lead is used to give a bloom to black teas. As an Article of Did. — Tea seems to have a decidedly stimulative and restorative action on the nervous system, which is perhaps aided by the warmth of the infusion. No depression follows this. The pulse is a Uttle quickened. The amount of pulmonary carbon dioxide is, according to E. Smith, increased.^ The action of the skin is increased, that of the bowels lessened. The kidney excretion is Httle affected, perhaps the ui'ea is a Uttle lessened, but this is uncertain.^ As an article of diet for soldiers, tea is most useful. The hot infusion, like that of coffee, is jDotent both against heat and cold ; is most useful in great fatigue, especially in hot chmates (Eanald Martin) ; and also has a great piuifying effect on water. Tea is so light, "is so easily carried, and the infusion is so readily made, that it should form the drink par excellence of the soldier on service. There is also a behef that it lessens the suscej)- tibility to malaria, but the evidence on this point is imperfect. Choice of Tea. — The tea should not be too much broken up, or mixed up -^ith dii't. Spread out, the leaves should not be all large, thick, dark, and old, but some should be small and young. There will always be in the best tea a good deal of stalk and some remains of the flower. In old tea much of the ethereal oil evaporates, and the aroma is less marked. The infusion should be fragTant to smell, not harsh and bitter to taste, and not too dark. The buyers of tea seem especially to depend on the smell and taste of the infusion. Structure of the Tea Leaf. — The border is seiTated nearly, but not quite to the stalk ; the primary veins run out from the midrib nearly to the bor- der, and then turn in, so that a distinct space is left between them and the border. The leaf may vary in point of size and shape, being sometimes broader, and sometimes long and narrow. The appearance under the microscope of the ujoper and under surfaces is seen in the drawing. The border and the jjrimaiy venation distingniish it from all leaves,* The leaves ' The brick tea of fhe Tartars consist of old tea leaves, mixed with, the leaves and stems of RJuimnus theezans, Rlwdodendron, Chrysanthemum, Rosa canina, and other plants, mixed with ox's or sheep's blood. It is much used to purify water. - Phil. Transactions, 1859. 3 The evidence with respect to the urine is very contradictory ; but, on the whole, the action seems to be inconsiderable. Dr. Edward Smith considers that " tea pro- motes all vital actions, and increases the action of the skin. " It is, perhaps, impossible at present to express its action in so succinct a form. •* The structure of the serrature is rather peculiar, showing an apparently abortive leaf-bud just within the point. This organ can be seen distinctly with an ordinary pocket lens, and consists of a cylindrical basal portion and a more or less cone-shaped apical part. From the reticulated bodv of the venation, a distinct little funiculus may be traced into each of tlie minute bud-fflse bodies which are situated just loitMn the tip of the serrature. This latter particular is of importance, for, as might be expected, some- what similar appendages may be found in other serrated leaves, but in all cases hith- erto examined by us, they occur at instead of withm the point of the serratures. No 334 PEACTICAL HYGIENE. ■which it is said have been mixed with or substituted for tea in this coun- try are the willow, sloe, oak, Valonia oak, plane, beech, elm, poplar, haw- thorn, and chestnut ; and in China, Chloranthui^ inco)isjncuus and Camellia Sasanqua are said to be used. Of these the willow and the sloe are the only leaves which at all resemble tea leaves. The willow is more irregularly, and the sloe is much less pei-fectly and uniformly serrated. To examine the leaves, make an infusion, and then spread out a number of leaves ; if a leaf be placed on a glass slide, and covered with a thin glass, and then held up to the light, the border and venation can usually be well seen. Tlie leaves of the Valonia, if used, are at once detected by acicular crys- tal being found under the microscope. Sometimes exhausted tea leaves are mixed with catechu or with a coarse powder of a reddish-brown color, consisting chiefly of powdered catechu, Upper Surface. Under Surface. + 2S5. Fig. 61.— Dried Black Tea Leaf. and called " La Veno Beno." Gum and starch are added, the leaves being steeped in a strong solution of gum, which, in drying, contracts them. The want of aroma, and the collection at the bottom of the infusion of powdered catechu, or the detection of particles of catechu, will at once in- dicate this falsification, which is, however, very uncommon. Sand and notice appears to have been taken of this fact by structural botanists ; bnt Dr. Mac- donald, who first called attention to it, refers the bodies themselves to the category of marginal buds. — (F. de C.) Plate VIII.— A. Leaves and stalks of best Tea brought from China (1861) by private hand ; natural size. Generally in Commercial Tea, the leaves are much larger and thicker, and often are cut transversely into two or three parts. Some stalks and remains of ilowers are found in all Tea, even the best. "WiUqw Ka-wtliom. IVillQW Plate VIII —B. Camellia Sasanqua. Chloranthus Inconspicuus. Leaves Used in the Adulteration op Tea. The Sloe, Willow, Oak, Beech, Elder, and Hawthorn have been nature-printed and then lithographed. The drawings of the Chloranthus Inconspicuus and the Camellia Sasanqua, which are said to be used by the Chinese, are copied from Hassall. The leaves of the Elm Poplar Plane are said to be sometimes used in England. Falsifica- tion with any kind of leaf is, however, now decidedly uncommon in this country. BEVERAGES AND CONDIMEISTTS. 835 magnetic oxide of iron are added by the Chinese. At first the latter was mistaken for iron fihngs, and when it was proved to be really magnetic oxide it was suggested that it came accidentally from the soil where the tea was cultivated. Hassall, however, gives good reasons for its being a wilful addition.' Extraction of Jliein. Occasionally it may be desu-ed to determine the quantity of thein. Take 10 grammes of tea, exhaust ^\^.th boiling water, and add solution of subacetate of lead ; filter ; pass hydrosulphmic acid through to get rid of excess of lead ; filter ; evaporate to small bulk, and add a little ammonia ; add more water, decolorize with animal charcoal, and evaporate slowly to small bulk. White feathery crystals of thein form, which should be collected on filtering paper, dried at a veiy low heat, and weighed. Determination of Tannin. Make an infusion and add solution of gelatine ; collect precipitate, dry and weigh — 100 = 40 of tannin (Mai-cet). Examination of Tea. Judge of the aroma of the dry tea and infusion ; taste infusion ; spread out leaves and see their characters ; collect anything like mineral powder, and examine under microscope. The microscope will also show if the tea has deteriorated by keeping ; sometimes acari, fungi, and bacteria may be found. To make the infusion, take 10 grammes of tea, and infuse in 500 C.C. of boiling distilled or rain water. '^ Let it stand five or six minutes before smeUing and testing it. Exhaust the leaves by boiling with successive portions of water, until no color is given up to the water. Measure the total amount of the infusion; take 100 C.C. and dry it in a water-bath,^ and weigh. Calculate out the percentage. Example. — The total quantity of the infusion from 10 grammes of tea was 1,890 C.C. ; 100 C.C. taken and dried yielded 0.21 of extract ; then - - - X 0.21 = 3.969 of extract in 10 grammes ; this multiplied by 10 = 29.69 per cent. The exhausted leaves may also be dried and weighed, the loss repres- enting the amount of extract, which ought to correspond with the amount obtained directly. The ash should also be determined ; 5 or 10 grammes are to be incin- erated ; the ash is generally gray, sometimes slightly greenish. Any excess ' I have found minute quantities in two instances in tea supplied to Netlej Hospital ; in one the ash was 6.054 per cent. ; in the other, 6.220. Hassall states that he has never found it except in tea that has been undoubtedly adulterated and yielded a very Bauch greater amount of ash. — (F. de C.) '■* The dealers usually-take as much tea as is equal in weight to a new sixpence for the infusion. This is equal to about 3 grammes ; it is dissolved in a cupful of water, about 5 ounces or 140 C.C. ■^ Mr. Wanklyn suggests a simple form of water-bath ; an ordinary tin oil-can about three-parts full of water ; this is boiled over a lamp, and the dish witli infusion to be dried held over the narrow mouth in the ring of a retort stand. The drying is soon completed in the steam. 336 PEACTICAL HYGIENE. above 6 per cent, is suspicious ; if above 8 per cent, on ^e perfectly dry tea, adulteration is certain." About one-half of the ash is soluble in water ; the solution is often (but not always) pink, from the presence of manganese. The amount and character of the ash form good means of detecting the use of exhausted leaves. The acidity of the infusion, and the amount of tannin and thein may also be determined ; as also the chlorine, alkalinity and u-on of the ash. The best tests of the quality of the tea are the aroma and the physical chai'acters. Sub-Section HE. — Cocoa. Gomposition. — Although the theobromin of cocoa closely resembles thein and caffein, the composition of cocoa removes it widely from tea and coffee. The quantity of fat is large ; it varies even in the same sort of cocoa, but is usually fi'om 45 to 49 per cent,' The. theobromin is 1.2 to -I 4 ; 1 1 H Fig. 62. —Cocoa, Outer Coat 1.5 per cent. ; the protein substances 13 to 18 per cent. The ash contains a large quantity of phosphate of potassium. As an Article of Diet. — The large quantity of fat and albuminoid sub- stance makes it a very nourishing article of diet ; and it is therefore use- ful in weak states of the system, and for healthy men under cu'cumstances of great exertion. It has been even compared to milk. In South America ' The Society of Public Analysts have adopted 20 per cent, of cocoa butter as the miuimum admissible. BEVERAGES AXD CON"DLMENTS. 337 cocoa and maize cakes are used loy ti-avellers ; and the large amount of agi'eeable nouiisliment in small bulk enables several days' supplies to be easily carried (Humboldt;. By roasting, the starch is changed into dextrin ; the amount of mar- garic acid increases, and an empyreumatic aromatic substance is formed. The changes depend on the amount of roasting ; the lighter-colored nuts contain more unchanged fat, and less aroma ; the strongly roasted and dark cocoas hare more aroma and bitterness. Choice and Adulterations. — In commerce, cereal grains, starches, arrow- root, sago, or potato starch and sugar, are veiy commonly mixed with cocoa ; and some of the so-called homoeopathic cocoas are rightly named, for the amount of cocoa is very small. Brick-dust and peroxide of iron are sometimes used (Noimandy).^ The structure of the cocoa is very marked. Fig 65. —Cocoa, TJnder Parts, iGddle Coat x 190, The starch-grains of cocoa are small, and embedded usually in the cells. The presence of starch-gTains of cereals, arrowroot, sago, or other kinds of starch, is at once detected by the microscope. Sugar can be detected by the taste, and by solution. ^Mineral substances are best detected by in- cineration, digesting in an acid and testing for iron, lead, etc. ' Hassall examined 54 samples ; 8 were geniuiie, 43 contained sugar, and 46 starch. ; 39 out of 68 samples contained earthy coloring matter, as reddle, Venetian red, and umber. — On Adulteration, p. 166. Vol. I.— 22. 338 PRACTICAL HYGIENE. SECTION m. CONDIMENTS. Sub-Section I. — Vinegar. As an Article of Diet. — Robert Jackson was of opinion that the use of vinegar was too restricted in the army. This ojjinion he appears to have formed from considering the great use of vinegar made by the Romans. Whatever may have been the source of the opinion, there is no doubt of its correctness. Acetic acid plays that double part in the body which seems so important, of first an acid of a neutral salt, and then, in the form of carbonic acid, as the acid of an alkaline salt. But this valuable dietetic quality is partly counterbalanced in English vinegar by the unfortimate circumstance that sulphuric acid (y ^^y^th in weight) is allowed to be added to \'inegar, and thus a strong acid is taken into the body, which is not only not useful in nutrition, but is hurtful from the tendency to form insoluble salts of lime. As the addition of sulphuric acid is not necessary,' and, indeed, is not permitted on the Continent, it is to be hoped the legislature will soon alter a system which has the effect only of injuring an important article of diet. The amount of vinegar which may be used may be from one to several ounces. On marches, the Romans mixed it with water as a beverage. Examination of Vineqar. — Several kinds of vinegar are in the market, known by the Nos. 16, 'l8, 20, 22, and 24. Nos. 22 and 24 are the best, and contain about 5 per cent, of pure glacial acetic acid. The weakest kinds contain less than 3 per cent. The Society of Public Analysts have adopted 3 per cent, as the minimum admissible. Quality. — 1. Take specific gravity ; of the best, = 1022 ; of the worst, ::= 1015. If below this, water has been added. 2. Determine acidity of 10 C.C. with the alkaline solution.'' It is generally best to dilute the vinegar ten times with distilled water, and to take 10 C.C. of the diluted vinegar. Multiply the C.C. of alkahne solution used by 0.6, the result is acetic acid per cent. Example. — 10 C.C. of diluted vinegar took 8 C.C. of alkaline solution : 8 X 0.6 = 4.8 per cent, of acetic acid. The acidity of English vinegar is chiefly caused by acetic and sulphuric acids, but it is usually calculated at once as glacial acetic acid. If it falls below 3 per cent.^ water has probably been added. (The lowest noted by Hassall in 33 samples was 2.29.) If the specific gi'avity be low, and the aciditj^ high, excess of sulphuric acid may have been added. Sodium carbonate of ammonia gives a pui-plish precipitate in imie vin- egar, but not in malt vinegar. If excess of sulphuric acid be suspected, it must be determined by baryta ; this requires care, as sulphates may be introduced in the water. Hydrochloric acid and barium chloride are added ; the sulphate of barium collected, dried, weighed, and multiplied by .34305. ' The absence of Anguillula Aceti has been by some attributed to the use of sul- phuric acid. See Micrographic Dictionary, article "Anguillula." In a sample I ex- amined, which swarmed with anguillulse, there was only a trace of sulphuric acid. — (F. de C.) " See Appendix A, Vol. II. ^ Hassall says 3 5 per cent. BEVERAGES AND C02^DIMEXTS. 339 Adulterations. — Water ; sulphuric acid in excess ;' hydrocliloric acid (uncommon) ; or common salt (detected by nitrate of silver and dilute ni- tric acid) ; pyroligneous acid (distil and re-distil the distillate, the residue will have the smell of p^Toligneous acid) ; lead ; copper from vessels (evap- orate to di-yness, incinerate, dissolve in weak nitric acid, diride into two ■Darts, pass SH„ thi'ough one, and test for copper in the other by ammonia, jr by a piece of iron \dve) ; corrosive sublimate (pass SH, through, collect precipitate) ; capsicum, pellitory, or other pungent substances (evaporate nearly to dryness, and dissolve in boiling alcohol, evaporate to syrup, taste ; burnt sugar gives a bitter taste and a dark color to the syrup). The presence of copper in the vinegar used for pickles may be easily detected by simply inserting the bright blade of a steel knife. SuB-SeCTIOX n. MuSTAIlD. Good mustard is known by the shai-p acrid smell and taste. It is adulterated vdih. turmeric (detected by microscope and liquor potassfe), wheat or barley starch (detected by microscope and iodine), and linseed (detected by microscope). Many samples of mustard are still mixed with Fig. 64. — White ITustard Seed. Cuticle consisting of a perforated cellular epiderm and mticilage-oelIs>, some by expansion esciiping through the cuticular openings after being placed in water. turmeric and starch of some kind, but this has very much lessened since the passing of the Adulteration Act. Clay and plaster-of-Paris are some- times added, and cayenne is added to bring up the sharpness, if much flour is used. The microscopic characters of mustard are well marked. The outer coat of the white mustard consists of a stratum of hexagonal cells, perfo- rated in the centre, and other cells which occupy the centre portion of the ^ The presence of sulpMTric acid may be detected qualitatively, by adding a few drops of the vinegar to a piece of cane sugar, and evaporating on the water-bath. The solution becomes black in proportion to the mineral acid present. — HdssaU. 340 PRACTICAL HYGIENE. hexagonal cells, and escape through the opening -when swollen from imbi- bition of water ; these cells are believed to contain the mucilage which is Fig. 65. — ^White Mustard Seed. 1. Outer coat, cuticle mncilage-cella. 2. Fibrous reticular. 3. Small an- gular cells. 4. Large cells and verj' delicate membrane. 5. Interior of seed with a few minute oil-globules. obtained when mustard is placed in water. There are two internal coats made up of small angular cells ; the structure of the seed consists of nu- ^^ \ j^^^'* /f/ € :.^ 'A ^^»pv^^^^ m^ 1000 —i ^■ Fig. 66. — White Mustard Seed, central part, x 2C5. merous cells containing oil, but no starch. The black mustard has the same characters, without the infundibuliform cells. BEVERAGES AND CONDIMENTS. 341 Sub-Section Hf. — Peppee. Pepper is adulterated witli linseed, mustard husks, wheat and pea flour, rape cake, and ground rice. The microscope at once detects these adul- terations. The microscopic characters of pepper are rather complicated ; there is a husk composed of four or five layers of cells and a central part. The cortex has externally elongated cells, placed vertically, and provided with Fig. 67.— Section of Black Pepper Berry, central portion. a central cavity, from which lines radiate toward the circumference ; then come some strata of angular cells, which, toward the interior, are larger, and filled with oil. The third layer is composed of woody fibre and spiral cells. The fourth layer is made up of large cells, which toward the inte- rior become smaller and of a deep red color ; they contain most of the es- sential oil of the pepper. The central part of the berry is composed of large angular cells, about twice as long as broad. Steeped in water, some of those cells become yellow, others remain colorless. It has been supposed that the yellow cells contain piperine, as they give the same reactions as piperine does ; the tint, namely, is deepened by alcohol and nitric acid, and sulphiiric acid appHed to a dry section causes a reddish hue (Hassall). White pepper is the central pai-t of the seed, but some small particles ( f cortex are usually mixed with il It is composed of cells containing very small starch-grains. Hassall says that the central white cells are so hard they may be mistaken for particles of sand. A little care would avoid this. The starch-grains are easily detected, however small, by iodine. 343 PRACTICAL HYGIENE. Pepper dust is merely the sweepings of the warehouses. Eape or lin- seed cake, cayenne and mustai'd husks, are mixed Avith pejiper dust, and it is then sold as pepper. Fig. 68. — Transverse Section of Black Pepper Berry. Sub-Section IV. — Salt. The goodness of salt is known by its whiteness, fine crystalline charac- ter, dryness, complete and clear solution in water. The coarser kinds, containing often chloride of magnesium, and perhaps lime salts, are darker colored, more or less dehquesceut, and either not thorougloly crystallized or in too large crystals. SECTION IV. LEMON AND LBIE JUICE. These juices contain free acids in large quantities, chiefly citric, and a little mahc acid, sugar, vegetable albumen, and mucus. The exj^ressed juice of the ripe fniit of the Citrus L/'monum, as ordered by the British Pharmacopoeia, is said to have a specific gra\dty of 1.039, BEVERAGES AND COi!TDBrENTS. 343 and to contain on an average 32.5 grains of citric acid in one fluid ounce/ The fresh juice of the hme [Citrus Limetta, or Citrus acida) has a rather less specific gravity (1.037), and contains less acid (32.22 grains per ounce). ^ The veiy important Merchant Shipping Act/ which regulates the issue of lemon juice on board merchant vessels, does not define the strength ; but it has been stated by ]Mi*. Stoddart,'' that the Board of Trade standard is a specific gi-avity of 1030 without spuit, and 30 gi-ains of citric acid per ounce. It occasionally is as high as 1050. As found in commerce, for merchant shijojiiiig, or used in the Royal Navy, the hme or lemon juice is chiefly prepared in Sicily or the West Indies ; it is mixed with spirit (usually brandy or whiskey, which gives it a sHghtly greenish-yellow hue), and olive oil is poui'ed on the top. Sugar is added to it when issued, to make it more agi-eeable to taste, in the proportion of half its weight. Lemon juice is usually issued in bottles containing three to four pints, not cjuite filled, and is covered ■v\-ith a layer of olive oil. About 1 ounce of brandy is added to each 10 ounces of juice. Sometimes the juice is boiled, and no brandy is added ; the former kind keeps best (Armstrong). Both are equal in anti-scorbutic power (Arm- strong). Good lemon juice wiU keep for some years, at least thi-ee years (Armstrong) ; bad juice soon becomes tui-bid, and then stringy and mucil- aginous, and the citric and mahc acids decompose, glucose and carbon dioxide being formed. Some turbidity and precipitate do not, however, destroy its powers. As found in the market, it is frequently mixed vith water, and some- times with other acids. In 20 samples examined in 1868 by !Mr. Stoddart, 7 were geniiine, 5 were watered, and 8 were ai-tificial ; tartaric acid being present in one, and sulphuric acid in another samjDle.^ In the examination the points which seem of consequence, in addition to the determination of the free acidity, are the fragTancy of the extract and the alkalinity of the ash, proving the existence of some alkaline citrate. The latter could, however, be imitated, but the fragi'ancy cannot be so. Examination of Levion Juice. 1. Pour into a glass, and mark physical characters ; turbidity, precipi- tate, stringiness, etc. The taste should be pleasant, acid, but not bitter. Add lime water, and boil ; if free citric acid is present, a large precipitate of calcium citrate is formed, which redissolves as the solution cools. Evaporate very carefully to extract, to test the fragxancy, etc. ^ Mr. Stoddart (Pharm. Jour. , October, 1868) points out that the specific gravity is too high for the quantity of acid stated ; there may, however, be other ingredients. He gives himself the specific gravity as 1.040 to 1.045, and the citric acid as 89 to 46 grains per ounce (citric acid CeHeO,). ]VIr. Stoddart mentioned that when lemons are kept the citric acid decomposes, and glucose and carbon dioxide arise. But yet citric acid is made from damaged fruit. ■^ Stoddart, op. cit., p 205. ^ The Merchant Shipping Act, 1867. * Pharm. Jour., October, 1868, p. 204. ^ The lime juice used in the Arctic Expedition, 1875-76, gave on analysis 27 grains of citric per ounce as issued, that is, after being fortified with about 15 per cent, of proof-spirit. Before fortifying it contained 82 grains. (See analyses by Professor Att- field and Mr. Bell, Report of Committee on Scurvy, pages xliii. and li.). Samples ana- lyzed at Xetley showed a specific gravity of 1023 as issued, and 1085.7 after driving off the alcohol ; the extract was about 8+ per cent. The unfortified juice froze at 25" F. , the fortified remained liquid down to 15° F. Prolonged freezing at a temperature of nearly 0' F. produced no change in the character or amount of the constituents. 344 PRACTICAL HYGIENE. 2. Take the specific gravity, remembering that spirit is present ; then, if necessary, evaporate to one-half to drive oflf alcohol, dilute to former amount, and take si^ecific gravity at G0° Fahr. 3. Determine acidity by alkahne solution.' Express the acidity as citric acid (C^H^O.) ; 1 C.C. of the alkaline solution = 0.4 milhgrammes of citric acid. As the acidity is considerable, the best Avay is to take 10 C.C of the juice, add 90 C.C. of water, and take 10 C.C. of the dilute fluid, which will give the acidity of 1 C.C. of the undiluted juice. If the num- ber of C.C. used for the diluted juice is multiplied by 2.8 it gives the acid- ity in grains per ounce. ' 4. Test for adulteration, viz : — (a) Tartaric Acid. — Dilute and filter, if the lime juice be turbid ; add a Httle solution of acetate of potash ; stu* well, without touching the sides of the glass, and leave for twenty-foiu* hours ; if tartaric acid be present the potassium tartrate will fall. (b) Sulphuric Acid. — Add baiium chloride after filtration, if necessary ; if any precipitate falls, add a httle water and a few drops of dilute hy- drochloric acid to dissolve the barium citrate, which sometimes causes a turbidity. (c) Hydrochloric Acid. — Test with silver nitrate and a few drops of dilute nitric acid. {d) Nitric Acid. — This is an uncommon adulteration ; the iron or bru- cine test can be used as in the case of water. Factitioxis Lemon Juice. It is not easy to distinguish weU-made factitious lemon juice ; about 552 grains of crystallized citric acid are dissolved in a wine pint of water, which is flavored with essence of lemon dissolved in spirits. This coiTe- sponds to about 19 or 20 grains of diy citric acid per ounce. The flavor is not, howevei', like that of the real juice, and the taste is sharper. Evap- oration detects the falsification. Use of Lemon Juice. In military transports, the daily issue of one ounce of lemon juice per head is commenced when the troops have been ten days at sea, and by the Merchant Shipping Act (1867) the same rule is ordei-ed, except when the ship is in harbor, and fresh vegetables can be procui-ed. It is mixed with sugar. If dried vegetables can be procured, half the amount of juice will per- haps do. In campaigns, when vegetables are deficient, the same i-ules should be enforced. On many foreign stations, where dysentery takes a scorbutic type (as formerly in Jamaica, and even of late years in China), lemon juice should be regularly issued. Substitutes for Lemon Juice. Citric acid is the best, or citrate of potassium ; then perhaps vinegar, though this is inferior, and lowest of all is nitrate of potassium.^ The tar- ' See Appendix A, Vol. II. ' On this point see Bryson's paper in the Medical Times and Gazette, 1850. Ref- erence may also be made to a review on scurvy, which Dr. Parkes contributed to the British and Foreign Medico-Chirurgical Review, in October, 1848, for evidence on the point. BEVEEAGES AND CONDIMENTS. 345 trates, lactates, and acetates of the alkalies may all be used, but there are no good experiments on their relative antiscorbutic powers on record. If milk is procui-able, it may be allowed to become acid, and the acid then neutralized with an alkah. The fresh juices of many plants, especially species of cacti, can be used, the plant being crushed and steeped in water ; and in case neither vegetables, lemon juice, nor any of the substi- tutes can be procured, we ought not to omit the trial of such plants of this kind as may be obtainable. CHAPTER VIII. SOILS. TOPOGRAPHICAL REPORTS AXD CHOICE OF SITES. The term soil is used here in a large sense, to express all the portion of the cinist of the earth -which by any propert}' or condition can affect health. The subdivision into surface soil and subsoil is often verj'' usefvil ; and these terms need no definition. SECTION L CONDITION OF SOIL AFFECTING HEALTH. Soil consists of mineral, vegetable, and often animal substances, in the interstices of which are also air and often water. In reviewing the conditions which affect health, it will be convenient to commence with the aii' and the water in soils. Scb-Sectiox I. — The Am rs the Soil. The hardest rocks alone are perfectly free fi-om air ; the greater number even of dense rocks, and all the softer rocks, and the loose soils covering them, contain ah-. The amount is in loose sands often 40 or 50 per cent. ; in soft sandstones, 20 to 40 per cent. The loose soil turned up in agri- cultural operations may contain as much as 2 to 10 times its own volume of air. The nature of the air in soils has been examined by a good many ob- servei-s ; it is mostly veiy rich in carbon dioxide, is very moist, and proba- bly contains eflfluvia and organic substances, derived from the animal or vegetable constituents, but which have not been properly examined. Oc- casionally it contains carburetted hydrogen, and in most soils, when the water contains sulj^hates, a Uttle hydrogen sulphide may be found. It has been examined by Nichols' in America, Fleck* in Dresden, Fodor^ in Buda- Pesth, Le-vs-is and Cunningham '' in Calcutta, and many others. Nichols made his expeiiments in the Back-bay lands of Boston, Massachusetts, land made by throwing gravel upon sea mud. His first series of experi- ments was upon air drawn from depths of 3f to 54- feet. There was no hydrogen sulphide, and only a little ammonia ; the CO,, was from 1.49 to 2.26 volumes per 1,000, and varied inversely as the height of the grovmd- ' Sixtt Report of the Board of Health, Massachusetts, 1875. ^ 4''='' and o''^'' Jahresbericht der Chemischen Centralstelle, Dresden. 1876. 'Deutsche Yierteljahrschrifffiir offentliche Gesundheit., Band vii., p. 205,1875; also Hygienische Untersuchungen ueber Luft, Boden und Wasser, von Dr. Josef Fodor, Braunschweig, 1882. ■* The Soil in its Relation to Disease, Calcutta, 1875. SOILS. 347 water, wMch was very near the surface. This relation, however, was not constant at a depth of 6 to 10 feet. Fleck found at 2 metres the CO, 29.9 per 1,000, and the oxygen 163.3 ; at 6 metres, the CO^ 79.6, and the oxy- gen 148.5. Fodor found (out of 13 observations) at 1 metre from 8.99 to 10.89 of C0„, and oxygen from 187.97 to 213.35 ; at 4 metres (11 obser- vations) from 26.31 to 54.45 CO,, and oxygen from 179.06 to 185.32. The great amount of CO, points to very intense chemical changes in the ground, especially in the deep strata, but at the same time it may be very variable in different places. The amount of oxygen was in a measure inversely as the CO,. At a depth of 4 metres (13 feet) the air would be irrespirable, and would extinguish a light. (How many cellars go as deep as 13 feet into the ground, and the cellar air feeds the house with air !) From_ the examination of the organic matter, he comes to the conclusion that it is not necessarily its oxidation on the spot that produces the CO,, and that therefore the latter cannot be taken, except under certain conditions, as a measure of impurity, depending as it does to a large extent upon the per- meability of the soil' He found no hydrogen sulphide, biit a good deal of nitric acid and ammonia, the relative quantities depending upon free access of air or otherwise. As regards moisture, the mean percentage of humidity was 80.7 at 2 metres and 93.8 at 4. Lewis and Cunningham, in their observations at Calcutta, found results somewhat similar to those of Fodor, the CO, being greatest at the lower strata examined. The compo- sition of soil air differs at different times and seasons, the absolute and relative amounts of the constituents varying under varying conditions. Tke amount of air, in soils can be roughly estimated, in the case of rather loose rocks, by seeing how much water a given bulk will absorb, which can be done by the following plan : — Weigh a piece of dry rock, and caU its weight W : then weigh it in water and call this weight W^ : then take it out of the water saturated with moisture, and weigh it again : call this weight W,. We then have — (W„-W)100 , „ . ^—'r — „T — = percentage oi air. W - W; ■ When the soil is loose, Pettenkofer adopts the following plan : — Dry the loose soil at 212° Fahr. (100° Cent.), and powder it, but without crush- ing it very much ; put it into a burette, and tap it so as to expel the air from the interstices as far as possible ; connect another burette by means of an elastic tube with the bottom of the first burette and clamp it on ; pour water into No. 2 burette, and then, by pressing the clamp, allow the water to rise through the soil until a thin layer of water is seen above it ; then read off the amount of water thus gone out of the second burette. The calculation — Amount of water used x 100_ -! • 2 Cubic centimetres of dry soil '^ ' Fodor attempts to distinguish (but hardly successfully) between porosity andpe?-- meoibility. ^ Renk's plan is very simple. Take a measured quantity of soil, say 50 C.C. , shaken well together, so as to represent its natural condition as much as possible, and put it into a 200 C.C. graduated glass measure : then pour in 100 C.C. of water, and shake well so as to expel all air. Allow it to stand a little, and read ol the point at which the water stands. Suppose it stands at 125 C.C, then the 50 C.C. of soil and the 100 C.C. of water, when shaken together, only occupy a space of 125 C.C, the difference, 25 C.C, representing the bulk of air displaced from the 50 C.Cs. of soil: therefore 25 ^ X 100 = 50 per cent, of air or porosity in the sample of soil. 348 PRACTICAL HYGIENE. The sifoterranean atmosphere thus existing in many loose soils and rocks is in continual movement, especially "uhen the soils are dry ; the chief causes of movement are the diui-nal changes of heat in the soil, and the faU of rain, which must rapidly disjDlace the air from the supei-ficial layers, and at a later date, by raising the level of the ground water, will slowly throw out large quantities of air from the soil. Fodor considers the temperature of the air, the ground temperature, the action of the winds, rainfall, barometric pressure, and level of ground water to be all influential in causing movement of the gi'ound air, and consequent relative change in its constituents. As far as the C0„ was concerned, Lewis and Cunningham found that the ah' temperature and wind were both inopera- tive, whilst the moisture had the gi'eatest influence on the uj^per strata, and the ground-water on the lower. Local conditions must also influence the movement ; a house artificially wai'med must be continually fed with air from the ground below, and doubtless this air may be drawn from great depths. Coal gas escajjing from i^ipes, and prevented fi'om exuding by frozen earth on the surface, has been known to pass sideways for some distance into houses.' The air of cessj)ools and of i^orous or broken drains will thus pass into houses, and the examination of drains alone often fails to detect the cause of effluvia in the house. The unhealthiness of houses built on " made soils," for some time after the soils ai-e laid down, is no doubt to be attributed to the constant ascent of impure aii' from the impure soil into the warm houses above. To hinder the ascent of air from below into a house is therefore a sani- tary point of importance, and should be accompHshed by paving and con- creting the basement, or, in some cases, by raising the house on arches off the gi'ound. The improvement of the health of towns, after they are well paved, may partly be owing to lessening of effluvia, though partly also to the greater ease of removing surface impuiities. Li some malarious dis- tricts great benefit has been obtained by coveiing the ground with gi-ass, and thus hindering the ascent of the miasm. As a iTile, it is considered that loose porous soils are healthy, because they are diy, and, with the quahfication that the soil shall not furnish nox- ious effluria from animal or vegetable impregnation, the rule appears to be coiTect. It is, however, undoubted that diy and apparently tolerably pui*e soils are sometimes malarious, and this arises either from the soils being really mipure, or from their porosity allowing the transference of air from considerable distances. Even on the jDurest soils it is desirable to observe the nile of cutting off the subsoil au* from ascent into houses. The diseases which have been attributed to telluric effluria are — Paroxysmal fevers. Enteric (typhoid) fever. Yellow fever. Bihous remittent fever. Cholera. Dvsenters'. The questions connected with these effluvia will be noticed farther on. The Water ix the Soil. The water present in soils is divided into moisture and gi'ound water. When air as well as water is present in the interstices, the soil is merely moist. The ground water must be defined, with Pettenkofer, as that con- dition in which all the interstices ai'e filled with water, so that, except in 'Lancet, 1873, vol. ii., p. 592. SOILS. 349 so far as its particles are separated by solid portions of soil, there is a con- tinuous sheet of Avater. Other definitions of gTOund water have been given, but it is in this sense it is spoken of here. Moisture of Soil. — The amount of moisture depends on the power of the soil to absorb and retain water, and on the supply of water to the soil either from rain or giound water. With respect to the first point, almost all soils will take uj) water. Pf aff ' has sho\^Ta that di-ied quartz sand on a filter can take up as much as 20 per cent, of water, and though in the natural condition in the soil the absorption would not be so great, there is no doubt that even the hardest sands retain much moisture. After several months of long-continued drought, Mr. Church found a light calcareous clay loam subsoil to contain from 19 to 28 per cent, of water. A loose sand may hold 2 gallons of water in a cubic foot, and ordinaiy sandstone may hold 1 gallon. Chalk takes 13 to 17 per cent. ; clay, if not very dense, 20 ; humus, as much as 40 to 60, and retains it strongly. The so-called "cotton soil" of Central India, which is derived from trap rock, absorbs and retains water with gi'eat tenacity ; the driest granite and marbles will contain from .4 to 4 per cent, of water, or about a jjint in each cubic yard. The moisture in the soil is derived partly fi-om rain, to which no soil is absolutely impermeable, as even granite, clay slate, and hard limestone may absorb a little. Practically, however, soils may be divided into the impermeable (unweathered gTanite, trap and metamorjDhic rocks, clay slate, dense clays, hard oolite, hard limestone and dolomite, etc.) and per- meable (chalk sand, sandstone, vegetable soils, etc.). The amount of rain, passing into the soil is influenced, however, by other circumstances— by the declivity and inclination of the soil ; by the amount of evaporation, which is increased in summer ; by hot winds ; and by the rapidity of the fall ('f rain, which may be greater than the soil can absorb. On an aver- age, in this countiy, about 25 per cent, of the rain penetrates into the sand rock, 42 per cent, into the chalk, and from 60 to 96 per cent, into the loose sands. The rest evaporates or runs off the surface by the hues of natural drainage. The rapidity ydih. which the rain water sinks through soil evi- dently varies with circumstances ; in the rather dense chalks it has been supposed to move 3 feet downward every yeai', but in the sand its move- ment must be much quicker. The moisture of the soil is not, however, derived solely from the rain ; the ground water, by its own movement of rising and falling, and evapora- tion from the sui'face of the subterranean water-sheet, and capillary attrac- tion, makes the upper layers of the soil wet. By these several agencies the ground near the surface is in most parts of the world kept more or less damp. Determination of Moisture in the Soil. — By di'ying 10 grammes at a tern- perature of 220"^ Fahr. (104.4° Cent.), then weighing, exjDOsing to air, and observing the increase of weight, an idea is formed of the amount of moist- ui'e, and of the hygrometric properties of the soil. If the dried soil is put over water under a bell jar, it will be exposed to aii- saturated with moisture, or by observing the dry and wet bulb thermometers, the humidity of the air at the time can be noted. The Ground or Subsoil Water. — The subterranean sheet of water is at very different depths below the surface in different soils ; sometimes it is only 2 or 3 feet from the surface, in other cases as man;y hundi-eds. This ' Zeitsch. fiir Biologie, Band iv. , p. 249. 350 PRACTICAL HYGIENE. depends on the compactness or permeability of the soil, the ease or diffi- culty of outflow, and the existence or not of an impermeable stratum near or far from the surface. The underground sheet of water is not necessarily horizontal, and in some places it may be brought nearer to the surface than others by peculiarities of ground. The water is in constant move- ment, in most cases flowing toward the nearest watercourses or the. sea ; the rate of movement has not yet been perfectly determined. In Munich, Pettenkofer reckons its rate as 15 feet daily ; the high water in the Elbe moves the ground water in the vicinity at the rate of about 7 or 8 feet dail}'. Fodor' gives the mean rate at Buda-Pesth as 53 metres (174 feet), with a maximum of 6G metres (216 feet) in twenty-four hours, reckon- ing by the rise of the wells following the rise of the Danube. The rate of movement is not influenced solely by compactness or po- rosity of soil, or inclination. The roots of trees exert a great influence in lessening the flow ; and, on the other hand, water i-uns off more rapidly than before in a district cleared of trees. The level of the ground water is constantly changing. It rises or falls more or less rapidly, and at different rates in different places ; in some cases its movement is only a few inches either way, but in most cases the limits between its highest and lowest levels in the year are several feet (in Munich about 10). In India the changes are greater. At Saugor, in Central India, the extremes of the soil water are from a few inches from surface (in the rains) to 17 feet in May. At Jubbulpore it is from 2 feet from the surface to ] 2 or 15. The causes of change in the level of the ground water are the rainfall, pressure of water from rivers or the sea, and alterations in outfall, either increased obstmction or the reverse. The effect of the rainfall is sometimes only traceable weeks or even months after the fall, and occasionally, as in plains at the foot of hills, the level of the ground water may be raised by rainfalls occurring at great distances. The pressure of the water in the Khine has been shown to affect the water in a well 1,670 feet away. The pressure of the Danube at Buda-Pesth is fovmd to influence a w^ell at a distance of 2,700 feet (Fodor). In a place near the Hamble River (Hampshire) 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.^ Diseases connected loith Moisture and Ground Water. — Dampness of soil may presumably affect health in two ways — 1st, by the effect of the water, per se, causing a cold soil, a misty air, and a tendency in persons living on such a soil to catarrhs and rheumatism ; and 2d, by aiding the evolution of organic emanations. The decomposition which goes on in a soil is owing to four factors, \'iz., presence of decomposable organic matters (ani- mal or vegetable), heat, air, and moisture. These emanations are at pres- ent known only by their effects ; they may be mere chemical agencies, but there is increasing reason to believe that they are low forms of life which grow and propagate in these conditions. At any rate, moisture appears to be an essential element in their production. The ground water is presumed to affect health by rendering the soil above it moist, either by evaporation or capillary atti*action, or by alternate wettings and dryings. A moist soil is cold, and is generally believed to predispose to rheuma- tism, catarrh, and neuralgia. It is a matter of general expeiience that most persons feel healthier on a dry soil. ' Op. cit., Bd. ii., p. 98. ' Lectures on State Medicine, by F. de Chaumont (Smith & Elder), p. 91, 1875. SOILS. 351 In some way wMch is not clear, a moist soil produces an unfavorable effect on the lungs : at least in a number of English towns, which have been sewered, and in which the ground has been rendered much drier, Buchanan has shown that there has been a diminution in the number of deaths from "phthisis."' Dr. Bowditch of Boston (U.S.), and Dr. Middle- ton of Salisbury, noticed the same fact some years ago. Buchanan's evi- dence is very strong as to the fact of the connection, but the nature of the link between the two conditions of drying of soil and lessening of certain pulmonary diseases is unknown. It is curious how counter the observation runs to the old and erroneous view, that in malarious (and therefore wet) places there is less phthisis. A moist soil mfluences greatly the development of the agent, whatever it may be, which causes the paroxysmal fevers. The factors which must be present to produce this agent are heat of soil (which must reach a cer- tain point = isotherm of 65 "" Fahr. of summer air temperature), air, moist- ure, and some impurity of soil, which in all probabihty is of vegetable nature. The rise and fall of the ground water, by supplying the requisite degree of moisture, or, on the contrary, by making soil too moist or too dry, evidently plays a large part in producing or controlling periodical out- breaks of paroxysmal fevers in the so-called malarious countiies. The de- velopment of malaria may be connected either with rise or with fall of the ground water. An impeded outflow which raises the level of the ground water has, in malarious soils, been productive of immense spread of parox- ysmal fevers. In the making of the Ganges and Jumna Canals, the outflow of a large tract of country was impeded, and the course and extent of the obstruction was traced by Dempster and Taylor by the almost universal prevalence of paroxysmal fevers and enlarged spleens in the inhabitants along the banks." The severe and fatal fever which has prevailed in Burd- wan, in Lower Bengal, for a number of years past, appears to be in part owing to the obstruction to the natural drainage from mills and from blockage of watercourses.^ In some cases relative obstruction comes into play ; i.e., an outfall sufficient for comparatively dry weather is quite inade- quate for the rainy season, and the ground water rises. At Pola, in Istria, for example, there are no marshes, but in the summer sometimes half, sometimes 90 per cent, of all cases are malarious ; . the reason is, that a dense clay lies a little below an alluvial soil, and the only exit for the rain is through two valley-troughs, which cannot carry off the water fast enough in the wet season,^ from February to May. A remarkable, instance of excessive rainfall, causing an outbreak of malarial disease, occurred at Kurrachee, in Scinde, in 1869. The average ' Buchanan : Ninth, and Tenth Eeports of the Medical Officer to the Privy Conncil, 1866, p. 48, and 1867, p. 57. As the term "phthisis" is a general one, and includes all the fatal diseases of the lungs, with destruction of lung-tissue (tuberculous and in- flammatory), as well as other cases of wasting, with pulmonary symptoms, it would be well to translate the word " phthisis " by the phrase " wasting diseases of the lungs." ^ The observations of Dempster and Taylor on the Jumna Canal have been more recently confirmed by Ferguson (Sanitary Administration of the Punjab for 1871, Ap- pendix IV.), who has investigated the effect on malarious disease on the Ba'ri Dodb Canal District ; he found canal irrigation increased malarious fever, and apparently by raising the soil-water levels. " Dr. Derby (Third Report of the State Board of Health of Massachusetts, Boston, 1872) points out how ague has been produced by obstructions to outflow, such as tide- mills, etc. So long ago as 1828, authority to remove a dam was obtained on account of injury to health. See also case recorded by Dr. Cattell in Natal, Army Medical Re- ports, vol. xiii., 1871, p. 178, produced by natural causes. * Dr. Jilck, in Archiv der Heilk., 1870, p. 493. 352 PRACTICAL HYGIENE. annual rainfall in Scinde in 11 years (1856-66) was only 6.75 inches ; and the gi'eatest rainfall in that time was 13.9 inches (1863). In 1867 the rainfall was 2.73, in 1868 it was 3.36 inches ; while in 1869 it reached the unprecedented amount of 28.45 inches, of which 13.18 feU in July and 8.39 inches in September. Ajiiil, May, October, November, and December were rainless. The 1st Batt. 21st Kegiment had the following attacks of paroxysmal fever per 1,000 of strength : — In April, none ; in May, 9 ; in June, 39 ; in Jiily, 30 ; in August, 93 ; in September, 105 ; in October, 198 ; in November, 1,004 ; and in December, 644. In December the regiment was embarked for Madras, as it had "thoroughly lost heart." The disease was not fatal, as the death-rate for the year, from all causes, was only 25.7 per 1,000. At Kurrachee, as the rainfall is usually so small, the ground dries fast, and is then non-malaiHous. The ground is flat, and there is no subsoil drainage. In 1866, when there was heays' rainfall (13.75 inches), there was also a development of malarial disease, which was continued in 1867. The oj^posite resvdt, viz., an increased outflow lowering the subsoil water, has been observed in drainage operations, and very malaiious places have been rendered quite healthy by this measure, as in Lincolnshire, and many parts of England. The case of Boufaric, in Algeria, is a good in- stance ; successive races of soldiers and colonists had died off, and the sta- tion had the worst reimtation. Deep drainage was resorted to ; the level of the gi'ound water was lowered less than 2 feet. This measure, and a better suj^jily of diinking-water, have reduced the mortality to one-third. A case mentioned by Pettenkofer ' is also very striking as to the effect of subsoil di-ainage on some kind of fever in horses. Two royal stables near Munich, with the same aiTangements as to stalls, food, and attend- ance, and the same class of horses, suffered veiw luiequally fi'om fever ; horses sent from the unhealthy to the healthy stables did not communicate the disease. The difference between the two places was, that in the healthy stables the ground water was 5 to 6 feet, in the unhealthy only 24- feet from the surface. Draining the latter stables, and reducing the ground water to the same height, made these stables as healthy as the others. Typhoid (enteric) fever has also been supposed to be connected with changes in moisture of the soil, owing to rising and falling of the gTound water. Professor Pettenkofer's obseiwations on the weUs of Munich led Buhl to the discovei-y that in that city there is a veiy close relation between the height of the gi-ound water and the fatal cases of tjiihoid ; ^ the out- breaks of t%-phoid fever occun-ed when the gi-ound water was lowest, and especially when, after hariug risen to an unusual height, it had rapidly fallen. Pettenkofer has repeated and extended the inquiry with the same results. The point has been also numerically investigated by Seidel ' in Munich and Leipzig for the years 1856-64 and 1865-73, and from a mathematical consideration of the numbers he concludes that, according to the theory of probabilities, it is 36,000 to 1 that there is, in each pe- riod, a connection between the two occurrences.* Other observations in ' Quoted by Kirchner, Lehrb. der Mil. -Hygiene, 1869, pp. 217, 218. ' Zeitschrift fiir Bioloe:ie, Band i. , p. 1. 3 Ibid., Band i., p. 221, and Band ii., p. 14.5. •• Ranke, however, points out that no typhoid exists in the neighborhood of Munich, but what is imported from Mianich, although soil and ground water are the same. Munich has a soil consisting of fine sand, with a peculiar power of holding nitrogenous substances ; it is provided with cesspools, from which more than 90 per cent, of the SOILS. 353 Germany are confirmatory/ but in this country the connection has not been traced. In some outbreaks of enteric fever, the ground water has been rising and not falling. Fodor ^ says that at Buda^Pesth the rise of enteric fever mortality accompanies the rising ground water, and the two fall together. In other instances the attacks have been traced to impure drinking-water or milk, to sewer emanations, or to personal contagion, and the agency of the ground water has appeared to be quite negative. Dr. Buchanan ^ has quoted a case, in which the sinking of the ground water and the outbreak of fever were coincident, and yet the connection was, so to speak, accidental, for the efficient cause of the outbreak was the poison- ing of the di-inking- water with typhoid evacuations. And he also j)oint8 out that when the ground water has actually been lowered in certain Eng- lish towns by drainage operations, typhoid fever has not increased as it should do, according to theory, but has diminished, owing to the intro- duction of pure water from a distance. He thus thinks that, while a con- nection between the j^revalence of typhoid fever and sinking of the ground water must be admitted to exist, it is indii-ect, and the true cause of the fever is impurity of the diinking-water. Pettenkofer has replied to this view," and denies, from actual analysis, the fact of the contamination of the driaking-water in tj'phoid outbreaks. At the present moment the observations of Pettenkofer, and the case of the barracks at Neustift, recorded by Buxbaum, are certainly in favor of the ojDinion that a direct connection may exist in some cases between the sinking of the ground water and outbreaks of tj'phoid ; but the frequency and extent of the connection remains to be detennined, and in this country, at any rate, the other conditions of spread of typhoid appear to be far more common. Assuming the truth of the connection, the other conditions which Pettenkofer considers necessary, besides a rapid sinking of ground water after an unusual rise, are impurity of the soil from animal impregnation, heat of soil, and the entrance of a specific germ.^ A very similar view is held by Pettenkofer in respect of cholera, and he has advanced many striking arguments " to show that while sporadic cases contents soak into the surrounding soil, and, as the streets are well paved, the houses are the only outlets for the foul soil-air. Virchow, in his Report on the Sewerage of Berlin, shows that the mortality is great- est in July and August, the curve corresponding accurately with the variation of the ground water, the death-rate being greatest at the lowest level ; this is chiefly due to deaths under one year. At the lowest level there is every year a little epidemic of typhoid. At Zurich in 1872 the results were directly opposed to Pettenkofer's views (see Lectures on State Medicine, p. 101). Geissler considers the influence of the rise and fall of the ground water a local matter, and agrees with Rudolph Rath in attribu- ting the typhoid of Berlin to contaminated water. The case of water transmission (which he quotes from Htigler) in the village of Lausen is a very conclusive one. (Schmidt's Jahrbiich., 1874, No. 2, 185 ; also Archiv fiir Klin. Medicin, 1873, p. 237 ; see also an abstract in the Report on Hygiene, Army Med. Reports, vol. xv., p. 197.) Vogt of Bern (Trinkwasser oder Bodengase) strongly supports Pettenkofer's views, and considers the propagation by drinking-water as illusory. ' Buxbaum, " Der Typhus in der Kaserne zxa Xeustift," Zeitsch. fiir Biologie, Band vi., p. 1. This seems strong evidence in favor of Pettenkofer's view. 2 Op. cit. 2 Medical Times and Gazette, March, 1870. ^ Ibid., June, 1870 ; and Vierteljahrschrift fiir offentliche Gesundsheitspflege, 1870, Band ii., pp. 176, 197. ^ Vierteljahrschrift fiir ofFentl. Ges., Band ii., p. 181. ° Among his many essays, special reference may be made to his Analysis of the " Reasons of the Immunity of Lyons from Cholera," Zeitsch. fiir Biol., Band iv., p. 400. Vol. I.-23 354 PRACTICAL HYGIENE. of cholera may occur, that there will be no \\ide-spread epidemic, unless certain conditions of soil are present, viz., an impxu-e porous soil, which has recently been rendered moist by a rise of grouud water, and then has been penetrated by air during the faU of ground water, and into which the spe- cific germ {Keim) of cholera has found its way. ' In Germany Pettenkofei-'s A-iews on the spread of cholera have not met "uith universal acceptance," though there are several instances in support. In India the weight of the e^•idence is at present against Pettenkofer's views ;^ but as investigations are now going on which will in a few yeai's settle the point, it is desirable at present to refrain from forming a decided opinion, except in so fai- that we may feel sure that the singularly localized outbreaks wliieh sometimes occur in India are qviite unconnected with any subsoil-water variations. In the report of ]M]\I. Lewis and Cunningham (op. cit.) it is shown that the cholera at Calcutta in 1873-74 followed the cui-ve of the ground water- level inversely, exactly in accordance with Pettenkofer's views. Dj'sentery and the so-called bilious remittent fevers, which occur in foul camps and on the ground largely contaminated by animal impurities, may be conjectured to be also influenced by variations in the gi-ound water, but satisfactory CA-idence has not yet been given. In the Calcutta Report, above cited, the maximum of fever corresponded with the maximum of C0„ in the soil atmosphere, and with the highest gi-ound water-level. Dysentery, on the other hand, showed two maxima, one at the rise of the water-level, and the other at the corresponding point of the faU, Fodor'* states that at Buda-Pesth cliolera, enteritis, and intei-mittent fever apj^ear to be connected with the processes which go on in the upper layer of the soil, and cholera mortahty rises and falls inversely with the grouud water-level, according to Pettenkofer's riew. Enteric fever, on the other hand, appears to be connected with the processes which go on in the lowest stratum of the soil, its mortahty vai^'ing du-ectly vnih. the ground water-level. The lowest lying parts of the city have the most impure soil, and are specially subject to cholera, enteritis, and tji^hoid fever ; whilst measles, scarlet fever, croup, and diphtheria appear* to invade all parts of the city indiflferently. Measurement of the Ground Water. — The height at which water stands in wells is considered to give the best indication of the height of the grouud water. Professor Pettenkofer uses a rod on which are fixed a number of httle cups, and when let down into the weU and drawn up again, the uppermost cup which contains water, marks, of coui'se, the height of the water ; the length of the cord or rod used for letting down the cups being ' It is, of course, to be understood that the impurity which aids in producing cholera is derived from persons ill with the disease. For a discussion on Pettenkofer's views on this point, see Report on Hygiene for lb72, in the Army Med. Department Report, vol. xiii. (1873) ; and for his latest views, vol. xxii. (1882), pp. 251 et seq. ■^ A careful analysis of this subject is contained in F. Kiichenmeister's work (Verbrei- tung der Cholera, 1872), and the work by F. Sander (Unters iiber die Cholera, 1872). Dr. Frank (health officer of Munich) believes that the cholei:a in 1873-74 was imported from Vienna, and points out that in 1873 the ground water and death-rate were not in accordance with Pettenkofer's theory. (See Report on Hygiene, Army Med. Report, vol. XV. , p. 203). ^ Townsend's Reports on the Cholera in Central India contain so many cases where ground water could have had no influence, that it appears impossible to accept Petten- kofer's theory. In Dr. Cornish's Eeport for 1871 are some good observations on sub- soil water, which if carried out in the same way for a few years will decide this ques- tion. * Op. cit. SOILS. 355 known, tlie changing level of the well can be estimated to within half an inch. Some precautions are necessary in making these observations ; if a rope is used, it may stretch with use, or in a hot dry wind, pr contract in wet weather, and thereby make the observation incorrect ; local conditions of wells, proximity to rivers, etc., must be learnt, else what may be termed local alterations in a well may be wrongly supposed to mean changes in the general level of the ground water. It is necessaiy, therefore, to make the observations simultaneously in many wells and over a considerable district. The observations should be made not less often than once a fortnight, and oftener if possible, and be carried on for a considerable time before any conclusions are drawn. Pettenkofer also uses a large float which is suspended by a chain travelling over a pulley : this supports an indicator at its other end, which marks the height on a fixed scale. Method of rendering Soil Drier. — There are two plans of doing this, — deep drainage and opening the outflow. The laying down of sewers often carries off water by leaving sjDaces along the course of the sewers, but this is a bad plan ; it is much better to have special di-ains for ground water laid by the side of or under the sewers. Deep soil drainage (the drains being from 8 to 12 feet deep and 10 to 20 feet apart) is useful in all soils except the most impermeable, and in the tropics should be carried out even on what are apparently dry sandy plains. In some cases soil may be rendered drier by opening the outflow. This is an engineering problem which physicians can only suggest. The clear- ing of water-courses, removal of obstinictions, and formation of fresh channels, are measures which may have an effect over very large areas which could not be reached by ordinary drainage. Sub-Section IL — Solid Constituents of the Soil. There are certain general features which can be conveniently considered first. 1. Conformation and Elevation. — The relative amounts of hill and plain ; the elevation of the hills ; their direction ; the angle of slope ; the kind, size, and depth of valleys ; the chief water-sheds, and the direction and discharge of the watercourses ; the amount of fall of plains, are the chief points to be considered. Among the hills, the unhealthy spots are enclosed valleys, punch-bowls, any spot where the air must stagnate ; ravines, or places at the head or entrance of ravines. In the tropics especially ravines and nullahs are to be avoided, as they are often filled with decaying vegetation, and currents of air frequently traverse them. During the heat of the day the cuiTent of air is up the ravine ; at night down it. As the hiUs cool more rapidly than the surround- ing plains, the latter current is especially dangerous, as the air is at once impure and cold. The worst ravine is a long narrow vaUey, contracted at its outlet, so as to dam up the water behind it. A saddleback is usually healthy, if not too much exposed ; so are positions near the top of a slope. One of the most difiicult points to determine in hilly regions is the probable direction of winds ; they are often deflected from theu' course, or the rapid cooling of the hills at night produces alteration. On plains the most dangerous points are generally at the foot of hills, especially in the tropics, where the water, stored up in the hills, and flowing to the plain, causes an exuberant vegetation at the border of the hills. 356 PEACTICAL HYGIENE. A plain at the foot of hills may be healthy, if a deep ravine cuts off completely the drainage of the hill behind it. The next most dangerous spots are depressions below the level of the plain, and into which therefore there is draiuage. Even gravelly soils may be damp from this cause, the water rising rajiidly through the loose soil from the pi*essure of higher levels. Elevation acts chiefly by its effect in lessening the pressure of the air, and in increasing the rapidity of evaporation. It has a powei'ful effect on marshes ; high elevations lessening the amount of malaria, partly from the rapid evaporation, partly from the greater production of cold at night. Yet malarious marshes may occur at great elevations, even 6,000 feet (Erzeroiim and Mexico). 2. Vegetation. — The effect of vegetation on gi'ound is veiy important. In cold climates the sun's rays are obstinicted, and evaporation from the gi'ound is slow ; the ground is therefore cold and moist, and the removal of Avood renders the climate milder and drier. The extent to which trees impede the passage of water through the soil is considerable. In hot countries vegetation shades the ground, and makes it cooler. The evaporation fi*om the surface is lessened ; but the evaporation from the vegetation is so gi-eat as to pi'oduce a perceptible lowering effect on the temperature of a place. Pettenkofer has calculated that an oak tree Avhich had 711,592 leaves, had during the summer months (May-October) an evaporation equal to 539.1 centimetres (= 212 inches), while the rainfall was only 65 centimetres (= 25.6 inches) ; so that the evaporation was 8^ times the rainfall ; this shows how much water was abstracted from the soil, and how the air must have been moistened and cooled. Observations in Algeria (Gimbert) have shown that the Uucalyj^tus globulus absorbs and evaporates 11 times the rainfall, extremely malarious places being rendered healthy in this way in four or five years. The hottest and driest places in the tropics are those divested of trees.' Vegetation produces also a great effect on the movement of air. Its velocity is checked ; and sometimes in thick clusters of trees or unden\'Ood the air is almost stagnant. If moist and decaying vegetation be a coin- cident condition of such stagnation, the most fatal forms of malarious dis- ease are produced. Vegetation may thus do harm by obstructing the movement of aii* ; on the other hand, it may guard from the ciu'rents of impure air. The pro- tective influence of a belt of trees against malaria is most striking. In a hygienic point of view, vegetation must be divided into herbage, brushwood, and trees ; and these should be severally commented on in reports. Herbage is always healthy. In the tropics it cools the ground, both by obstructing the sun's rays, and by aiding evaporation ; and nothing is more desirable than to cover, if it be possible, the hot sandy plains of the trof»ics with close-cut grass. Brushwood is frequently bad, and should often be removed. There is, however, evidence that the removal of bmshwood from a marsh has increased the evolution of malaria, and that, like trees, brushwood may sometimes ' It has been proposed (by Mr. Milne Home) to plant trees at Malta, with the view of improving and regulating the water-supply. Mr. Robert L. Stevenson has considered the thermal influence of forests, in a paper in the Proceedings of the Royal Society of Edinburgh (May 19, 1873). Single trees act as bad conductors ; the air of forests is generally cooler than free air, and certainly cooler than cleared lands ; forests heat the air during the day and chill it at night. SOILS. 357 offer obstruction to the passage of malaria. It must also be remembered that its removal will sometimes, on account of the disturbance of the ground, increase malarious disease for the time ; and therefore, in the case of a temporary camp in a hot malarious country, it is often desirable to avoid disturbing it. When removed, the work should be carried on in the heat of the day, i.e., not in the early morning or in the evening. Trees should be removed with judgment. In cold countries they shelter from cold winds ; in hot, they cool the ground ; in both, they may protect from malarious currents. A decided and pernicious interference with the movement of air should be almost the only reason for removing them. In some of the hottest countries of the world, as in Southern Burtoah, the in- habitants place their houses under the trees with the best effects ; and it was a rule with the Romans to encamp their men under trees in all hot countries. The kind of vegetation, except as being indicative of a damp or dry soil, does not appear to be of importance. Absorption of Heat. — The heat of the sun is absoi'bed in different amounts by different soils equally shielded or unshielded by vegetation. The color of the soil and its aggregation seem chiefly to determine it. The dark, loose, incoherent sands are the hottest ; even in temperate climates Arago found the temperature of sand on the surface to be 122° Fahr., and at the Cape of Good Hope Herschel observed it to be no less than 159°.' The heating power of the sun's rays is indeed excessive. In India, the thermometer j)laced on the ground and exposed to the sun will mark 160° (Buist), while 2 feet from the gTound it will only mark 120°. Buist thinks that if protected from currents of air it would mark 212°. when placed on the ground. The absorbing and radiating powers of soil are not necessarily equal, though they may be so. Generally the radiating power is more rapid than the absorbing ; soils cool more rapidly than they heat. Some of the marshes in Mexico cool so rapidly at night that the evolution of malaria is stopped, and the marsh is not dangerous during the night. A thermometer marked 32° Fahr. on the ground, while 16 feet above the ground it marked 50° Fahr. (Jomxlanet). In Calcutta, Lewis and Cunningham^ found that the temperature of the soil varied with the season. In hot weather the thermometer stood highest in the air, next highest in the upper stratum of the soil, and lowest in the lower stratum. Li cold weather the conditions were exactly reversed, the air being coolest and the lowest stratum of soil the hottest. During rain, however, these relations were not constant. With regard to absorbing power, the following table by Schtibler con- tains the only good experiments at present known : — Power of retaining Heat ; 100 being assumed as the Standard. Clayey earth 68.4 Pure clay 66.7 Fine chalk 6L8 Humus 49.0 Sand with some Ume 100.0 Pure sand 95.6 Light clay 76.9 Gypsum , 72.2 Heavy clay 71.11 The great absorbing power of the sands is thus evident, and the com- parative coldness of the clays and humus. Herbage lessens greatly the ab- ' Meteorology, p. 4. Op. cit. 358 PKACTICAL HYGIENE. Borbing power of the soil, and radiation is more rapid. On the Orinoco, a naked gi'anite rock has been known to have a temperature of 118° Fahr., while an adjacent rock, covered withgi'ass, had a temperature 32° lower. In cold countries, therefore, the clayey soils are cold, and as they are also damp, they favor the production of rheumatism and catan-hs ; the sands are, therefore, the healthiest soils in this respect. In hot countries the sands are objectionable from their heat, unless they can be covered with grass. They sometimes radiate heat slowly, and therefore the air is hot over them day and night. The sun's rays cause two currents of heat in soil : one wave diumal, the heat passing down in temperate climates to about 4 feet in depth dur- ing the day, and receding dm-ing the night — the depth, however, var}-ing with the nature of the soil, and with the season ; the other Avave is annual, and in temperate cUmates the wave of summer heat reaches from 50 to 100 feet. The hue of unifox*m yearly temperature is from 57 to 99 feet below the surface (Forbes). Not only does the amount of radiation differ in different soils, but a change is produced in the heat by the kind of soil. The remarkable re- searches of T}Tidall have shown, that the heat radiated from granite passes through aqueous vapor much more readily than the heat radiated by water (though the passage is much more obsti'ucted than in dry air). In other words, the himinous heat rays of the sun pass fi-eely through aqueous vapors, and fall on water and granite ; but the absorption produces a change in the heat, so that it issues again from water and granite changed in quality ; it will be most important for physicians if other soils are found to produce analogous changes. With regard to the effect of temperature of the soil on disease, it can hardly be doubted that it powerfully influences malaria, and probably also aids the progress of cholera. Rejiection cf Light. — This is a matter of color ; the white glaring soils reflect light, and such soils are generally also hot, as the rays of heat are also reflected. The effect of glare on the eyes is obvious, and in the tropics this becomes a very important point. If a spot bare of vegetation, and with a white sm-face, must be used for habitations, some good result might be obtained by coloring the houses pale blue or green. Chemical Composition of the Solid Parts of Soil. Vegetable Matters. — Almost aU soils contain vegetable matter. It exists in three chief forms — deposits, vegetable debris, and incinistations. De- posits occur in tracts of land which have been covered by silt brought down by floods, or which have been submerged by subsidence ; forests have been thus buried, and again elevated. In the marshes of the Tuscan Ma- remma, and in many other cases, the vegetable forms can be ti-aced with- out difficulty to a considerable depth, and the structure is even sometimes little changed, although so vast a period of time has elajDsed. Vegetable debris produced by the decay of plants lies on, or is washed into, the soil, and in this way the ground may be penetrated to gi'eat depths. In some cases, especially in sandy plains at the foot of hills, the rain brings down yery finely divided debris, and is filtered as it passes through the soil, so that each particle of sand becomes coated over or incrusted with a film of vegetable matter. If such a plain be subjected to alternate wettings and dr\^- ings, and to heat, the conditions of development of malaiia may be present SOILS. 859 in great intensity ; although there is not only no marsh, but the sand is to all appearance dry and pui"e. Animal matters. — The remains of animals are found in aU but the oldest rocks ; generally the animal constituents have disappeared, but it is re- markable how in some cases, even in geological formations as old as the tertiary strata, some animal matter may be found. On the surface there is perhaps no soil which does not contain some animal matters derived from dead animals or excreta, although, except in special cases, the amount is small. The soil of countries which have been long settled is, however, often highly impure in the neighborhood of habitations from the refuse (animal and vegetable) which is thrown out. In some loose soils cess-pits used for fifty years have never been emptied, and are still not full, owing to soakage. ' Pettenkofer conjectures that in Munich 90 per cent, of the excretions pass into the ground. In clayey soil there is, of course, much less infiltration than in sandy, and often scarcely any. In India, the nitrification of vast tracts of land is for the most part owing to the oxidation of animal refuse. A means of purification from animal impregnation has been, however, provided by oxidation, and the influence of growing vegetation. In aU soils, except the hottest and driest, animal refuse, under the influence of minute fermenting organisms, passes into nitrates, nitrites, and ammonia and fatty hydrocarbons, rather rapidly, and these are eagerly absorbed by vegetation. A means is therefore pointed out which may keep the soil clear from dangerous animal impregnations, and this is no doubt one rea- son why improvement in public health follows improved cultivation. It has become quite clear that in the plans for the disposal of the human and ani- mal excreta of towns, whether by wet or dry methods, an essential part of the plan is to submit these excreta to the influence of growing plants as soon as possible. Mineral matters,- — An immense number of mineral substances are scattered through the crust of the earth, but some few are in great prej)on- derance, viz., compounds of silicon, aluminum, calcium, iron, carbon, chlorine, phosphorus, potassium, and sodium. In examining the constituents of the soU round any dwellings, the im- mediate local conditions are of more importance than the extended geolo- gical generalizations ; it is, so to speak, the house and not the regional geology which is of use. Still the general geological conditions, as influen- cing conformation and the movement of water and air through and over the country, are of great importance. 1. The Granitic, Metamorphic, and Trap Bocks. — Sites on these forma- tions are usually healthy ; the slope is great, water runs off readily ; the air is comparatively dry ; vegetation is not excessive ; marshes and malaria are comparatively infrequent, and few impurities pass into the drinking water. When these ro.cks have been weathered and disintegrated, they are supposed to be unhealthy. Such soil is absorbent of water ; and the dis- integrated granite of Hong-Kong is said to be rapidly permeated by a fungus ; ^ but evidence as to the efi'ect of disintegrated granite or trap is really wanting. In Brazil ^ the syenite becomes coated with a dark substance, and looks like plumbago, and the Indians believe this gives rise to " calentura," or ' Gottisheim in Basel (Das unterirdisclie Basel, 1868). '^ Ost. Asiens, von C. Friedel, 1863. 2 M'Williams on Yellow Fever in Brazil, j). 7. oGO PRACTICAL HYGIENE. fevers. The dark granitoid or metamoi-pliic trap, or homblendic rocks in Mysore, are also said to cause periodic fevers ; and iron liornbleude espe- cially ^as affirmed by Dr. He^-ne of Madras to be dangerous in this respect. But the observations of Kichter ' on similar rocks in Saxony, and the fact that stations on the lower spurs of the Himalayas on such rocks are quite healthy, negative Heyne's opinion. 2. The Clay Slate. — These rocks precisely resemble the granite and granitoid formations in their effect on health. They, have usually much slope ; are veiy impermeable ; vegetation is scanty ; and nothing is added to air or to drinking-water. They are consequently healthy. Water, however, is often scarce ; and, as in the gi-anite districts, there are swollen brooks during rain, and diy watercoiu'ses at other times swelling rapidly after rains. 3. Tlie Limestone and Magnesian Limestone Bocks. — These so Tar resem- ble the former, that there is a good deal of slope, and rapid passing off of water. Marshes, however, are more common, and may exist at gi-eat heights. In that case the marsh is probably fed with water from some of the large cavities, which, in the coiu'se of ages, become hollowed out in the hmestone rocks by the cai-bonic acid of the rain, and form reservou's of water-. The drinking-water is hard, sparkling, and clear. Of the various kinds of limestone, the hard oohte is the best, and magnesian is the worst ; and it is desu'able not to jiut stations on magnesian hmestone if it can be avoided. 4. The Chalk. — The chalk, when unmixed with clay and permeable, forms a very healthy soil. The air is joure, and the water, though charged with calcium carbonate, is clear, sj^arkling, and pleasant. Goitre is not nearly so common, nor apparently calculus, as in the limestone districts. If the chalk be marly, it becomes impermeable, and is then often damp and cold. The lower parts of the chalk, which are underlaid by gault clay, and which also receive the drainage of the parts above, are often veiy ma- larious ; and in America, some of the most marshy districts are on the chalk. 5. The Sajulsfones. — The permeable sandstones are veiy healthy ; both soil and au- are dry ; the drhiking-water is, however, sometimes impure. If the sand be mixed with much clay, or if clay underhes a shallow sand- rock, the site is sometimes damp. The hard millstone giit formations are very healthy, and their conditions resemble those of granite. 6. Gravels oi any dei)th are always healthy, except when they are much below the general surface, and water rises through them. Gravel hillocks are the healthiest of all sites, and the water, which often flows out in springs near the base, being held up by underhing clay, is veiy pure. 7. Sands.~Th.ere are both healthy and unhealthy sands. The healthy are the pure sands, which contain no organic matter, and are of consider- able depth. The air is jiure, and so is often the drinking-water. Some- times the di-inking-water contains enough iron to become hard, and even chalybeate. The unhealthy sands are those which, like the subsoil of the Landes, in Southwest France, are composed of siliceous particles (and some iron), held together by a vegetable sediment. In other cases sand is unhealthy, from underMng clay or laterite near the surface, or from being so placed that water rises through its permeable ' Schmidt's Jahrbiich, 1864, No. 5, p. 240. SOILS. .861 soil from liigher levels. Water may then be found within 3 or 4 feet of the surface ; and in this case the sand is unhealthy, and often malarious. Impurities are retained in it, and effluvia traverse it. In a third class of cases, the sands are unhealthy because they contain soluble mineral matter. Many sands (as, for example, in the Punjab) con- tain much magnesium carbonate and lime salts, as well as salts of the alkalies. The drinking-water may thus contain large quantities of sodium chloride, sodium carbonate, and even lime and magnesian salts and iron. Without examination of the water, it is impossible to detect these points. 8. Clay, Dense Marls, and Alluvial Soils generally. — These are always to be regarded with suspicion. Water neither runs off nor runs through ; the air is moist ; marshes are common ; the composition of the water varies, but it is often impure with lime and soda salts. In alluvial soils there are often alternations of thin strata of sand, and sandy impermeable clay ; much vegetable matter is often mixed with this, and air and water are both impure. Vast tracts of ground in Bengal and in the other parts of India, along the course of the great rivers (the Ganges, Brahmaputra, Indus, Nerbudda, Krishna, etc.), are made up of soils of this description, and some of the most important stations even up country, such as Cawnpore, are placed on such sites. The deltas of great rivers present these alluvial characters in the highest degree, and should not be chosen for sites. If they must be taken, only the most thorough drainage can make them healthy. It is astonishing, however, what good can be effected by the drainage of even a small area, quite insufficient to affect the general atmosphere of the place ; this shows that it is the local dampness and the effluvia which are the most hurtful. 9. Cultivated Soils. — Well-cultivated soils are often healthy, nor at present has it been proved that the use of manure is hurtful. Irrigated lands, and especially rice fields, which not only give a great surface for evaporation, but also send up organic matter into the air, are hurtful. In Northern Italy, where there is a very perfect system of irrigation, the rice grounds are ordei-ed to be kept 14 kilometres ( = 8.7 miles) from the chief cities, 9 kilometres (=5.6 miles) from the lesser cities and the forts, and 1 kilometre (=1,094 yards) from the small towns. In the rice countries of India this point should not be overlooked. 10. Made Sods. — The inequalities of ground which is to be built upon are filled up with whatever happens to be available. Very often the refuse of a town, the cinders, or dust-heaps, after being raked over, and any sala- ble part being removed, are used for this purjpose. In other cases, chem- ical or factory refuse of some kind is employed. The soil under a house is thus often extremely impure. It appears, however,' that the organic matters in soil gradually disappear by oxidation and removal by rain, and thus a soil in time puiifies itself. The length of time in which this occurs will necessarily depend on the amount of impurity, the freedom of access of air, and the ease with which water passes through the soil. In the soil at Liverpool, made from cinder refuse, vegetable matters disappeared in about three years ; textile fabrics were, however, much more permanent ; wood and straw, and cloth, were rotten and partially decayed in three years, but had not entirely disappeared. In any made soil, it should be a condition that the transit of water through its outlet from the soil shall be unimpeded. The practice of filling up inequalities is certainly, in many cases, very objectionable, and should only be done under strict supervision. ^ See Report on the Health of Liverpool, by Dr. Burdon Sanderson, and the late Dr. Parkes, p. 9 et seq. 362 PRACTICAL HYGIENE. Sub-Section HL Malarious Soils. — Doubts have been expressed whether those parox- ysmal fevers, which ai'e ciu-able by quinine, are produced either by telluric efflu^^.a, or by substances passing from the soil into the drinking-water. The e\idence, however, appears conclusive in favor of both these modes of entrance into the body. If it be asked, What exact chemical conditions of soil favor the produc- tion of the malaria which causes periodical fevers ? the answer cannot be given, because no gi-eat chemist has ever systematically prosecuted this inquuy, and, in fact, it may be said that, singularly enough, there are few good analyses of malarious soils, although no problem is perhaps more im- portant to the human race. It seems pretty clear that the mineral constit- uents of the soil are of Httle or no consequence. Malaria will prevail on chalk, Hmestone, sand, and even, under special conditions, on gi'auite soils. The following soils have been known to cause the evolution of the agent causing periodical fevers in the malai^ious zone : — 1. Marshes. — Except these with peaty soils, those which are regularly overflowed by the sea (and not occasionally inundated), and the marshes in the southern hemisphere (Austraha, New Zealand, New Caledonia), and some American marshes, which, from some as yet unknoAvn condition, do not produce malaria. The chemical characters of well-marked marshes are a large percentage of water, but no flooding ; a large amount of organic matter (10 to 45 per ceni ) with variable mineral constituents ; sihcates of aluminum ; calcium, magnesium, and alkaline sulphates ; calcium carbonate, etc. The surface is flat, with a slight drainage ; vegetation is generally abimdant. The analyses of the worst malarious marshes show a large amount of vegetable organic matter. A marsh in Trinidad gave 35 f>er cent. ; the middle layer in the Tuscan Maremma, 30 per cent. The organic matter is made up of humic, ulmic, crenic, and apocrenic acids — all substances which require renewed investigation at the hands of chemists. Vegetable matter embedded in the soil decomj^oses very slowl}^ ; in the Tuscan Maremma, which must have existed many centuiies, if not thousands of j'ears, many of the plants are still luidestroyed. The slow decomposition is much aided by heat, which makes the soil alkaline from ammonia i^Angns Smith), and retarded by cold, which makes the gi'ound acid, especially in the case of peaty soils. It would now seem tolerably certain that the growing vegetation cover- ing marshes has nothing to do with the development of malaria. 2. Alluvial Soils. — Many allurial soils, especially, as lately pointed out by Wenzel,' those most recently formed, give out malaria, although they are not marshy. It is to be presumed that the newest allurium contains more organic matters and salts than the older formations. Many alluAaal soils have a flat surface, a bad outfall, and are in the vicinity of streams which may cause gi-eat variations in the level of the ground water. Mud banks also, on the side of large streams, especially if only occasionally cov- ered with water, may be highly malarious ; and this is the case also with deltas and old estuaries. 3. The soils of Tropical Valleys, Ravines and Nullahs. — In many cases large quantities of vegetable matter collect in valleys, and if there is any naiTowing at the outlet of the vaUey, the overflow of the rains may be im- ' Quoted by Hirsch, Jaitresb. fur die Ges. Med., 1870, Band ii., p. 209. SOILS. 363 peded. Sucli valleys are often very raalarious, and the air may drift up to the height of several hundred feet. 4. Sandy i^lains, especially when situated at ih& foot of tropical hills, and covered -with vegetation, as in the case of the " Terai" at the base of some parts of the Himalayan range. In other cases, the sandy plains are at a distance from hills, and are appai'eutly dry, and not much subjected to the influence of variations in the gi'ound water. The analysis of such sand has not yet been properly made, but two conditions seem of importance. Some sands, which to the eye appear quite free from organic admixture, contain much organic matter. Faure has pointed out that the sandy soil of the Landes in Southwest France contains a large amount of organic matter, which is slowly decomposing, and passes into both au- and water, causing periodical fevers. This may reasonably be conjectured to be the case with other malarious sands. Then, under some sands, a few feet from the surface, there is clay, and the sand is moist from evaporation. Under a great heat a small quantity of organic matter may thus be kept in a state of change. This is especially the case along the dried beds of water- coxu'ses and toiTents ; there is always a subterranean stream, and the soil is impregnated with vegetable matter. In other cases the sands may be only malarious duiing rains when the upper stratum is moist. 5. Certain hard rocks {granitic and metamorphic) have been ah'eady noticed (p. 359), especially when weathered, to have the reputation of being malarious; more evidence is requu^ed on this point. As Friedel justly remarks of Hong-Kong, it is not the disintegrated gTanite, per se, which causes the fever, but the soil of the woods and dells, and the clefts in the rocks, which were derived from the granite, and are soon filled with a cryptogamic vegetation. The magnesian limestone rocks which have been subjected to vol- canic action have also been supposed to be especially malarious (Kirk, who instances the rocks at Sukkar), but the evidence has not been yet coiToborated. 6. Iron Soils. — Sir Eanald Martin has directed attention to the fact that many reputed malarious soils contain a large proportion of iron. No good evidence has been adduced that this is connected with malaria, but the point requu'es further examination. The red soil from Sierra Leone, which con- tains more than 30 per cent, of oxides of iron, shows nothing which ap- pears hkely to cause malaria.' The peroxide of u-on is a strong oxidizing agent, readily yielding oxygen to any oxidizable substance, and regaining oxygen fi'om the air. It may, therefore, assist in the oxidation of vegetable matter in an ii'on soil.^ 7. In certain cases, attacks of paroxysmal fever have arisen from quite localized conditions unconnected with soil, which seem, however, to give some clue to the nature of the process which may go on in malarious gi'ound. Friedel ^ mentions that in the Marine Hospital at Smnemtinde, near Stettin, a large day-ward was used for convalescents. As soon as any man ^ Analysis of the Red Earth, of Sierra Leone, by Assistant-Surgeon J. A. B. Horton, M.D., Army Medical Reports, vol. viii., p. 333. - The surface soil of the Gold Coast (Connor's Hill, Cape Coast Castle), has also been analyzed by Mr. J. H. Warden, F.C.S. (Indian Medical Service). It contained only 3.28 per cent, of ferric oxide, and a trace of ferrous oxide ; the organic matter was only 4.4 per cent. The surface soil is only eight inches thick, and below this is a stratum of a dark red color, like burnt bricks, probably containing more iron. The sample above-mentioned was brought home by Surgeon-Major J. Fleming, A.M.D. — Army Medical Reports, vol. xiv., p. 264. » Ost. Asiens, p. 338. Berlin, 1868. 364 PRACTICAL HYGIENE. liad been in this wai'd for two or three days, he got a bad attack of tertian ague. In no other ward did this occiu-, and the origin of the fever was a mysteiy, until, on close insj)ection, a large rain-cask full of rotten leaves and binishwood was found ; this had overflowed, and formed a stagnant marsh of 4 to 6 square feet close to the doors and windows of the room, Avhich, on account of the hot weather, were kept open at night. The nature of the effluvium was not determined. Dr. Holden ' relates an instance in which, on board a ship at sea, eight cases of ague occurred from the emanations of a large quantity of mould which had formed in some closed store-rooms, which were exposed to the bilge-water.^ SECTION n. EXAMINATION OF SOIL. Mechanical Condition of Soil. — The degi-ee of density, friability, and penetration by water should be determined both in the surface and subsoil. Deep holes, 6 to 12 feet, should be dug, and water poui-ed on portions of the soil. Holes should be dug after rain, and the dej^th to which the rain has penetrated observed. In this way the amount of di'jTiess, the water- level, and the permeability can be easily ascertained. The surface or subsoil can also be mechanically analyzed by taking a weighed quantity (100 grammes), drying it, and then picking out all the large stones and weighing them, passing through a sieve the fine particles, and finally sej^arating the finest particles fi-om the coarser by mixing with water, allowing the denser jDarticles to subside, and pouring oif the finer suspended particles. The w^eight of the large stones, plus the weight of the stones in the sieve and of the dried coarser particles, deducted from the total weight, gives the amount of the finely divided substance, which is probably sihcate of aluminum. Temperature. — The temperature at a depth of 2 or 3 feet, at two to foui' o'clock in the afternoon, would be an important point to deteiToine in the tropics, and also the temperatui-e in early morning. At present such observations, though very easily taken, and obviously very instructive, ai-e seldom, if ever, made, although a commencement in that dii'ection has been made in the investigations of Messrs. Lewis and Cimningham at Calcutta.' It might also be useful to take a certain depth of soil, sa}- 6 inches, and, placing a thermometer in it, determine the height of the thermometer on exposure to the sun's rays for a given time at a certain hour. Chemical Examination. — The chemical constituents of soil are, of course, as numerous as the elements ; more than 500 minerals have been actually named. But certain substances are very rare, and, for the physician, the chief constituents of soils are the following substances or combinations : — Silica, alumina, Ume, iron, magnesia, chlorine, carbonic acid, phosphoric acid, nitric acid. A few simple tests are often very useful, if we are un- certain what kind of rock we have to deal with. Few persons could mis- take granite, trap, gneiss, or rocks of that class ; or clay-slate or cijstalline limestone. But fine white sandstones, or fi'eestoue, or even fine millstone gi'it, might be confoimded with lime rocks, or magnesian hmestone. A ' American Journal of the Med. Sciences, January, 1866. '^ Staff-Surgeon P. Mansfield, R.N., recounts an outbreak of yellow remittent fever on board ship at Rio, coincident with the growth of an enormous qiiautity of gigantic fungus in the hold. It seems unlikely, however, that this was more than a coinci- dence. • " Op. cit. SOILS. 365 few drops of hydrochloric acid will often settle the question, as it causes efifervescence in the calcium .carbonate and magnesian rocks. ' A more complete examination should include the following points : 1. Percentage of Water. — Take 10 grammes of a fair sample of soil, and dry at a heat of 220° ; weigh again ; the difference is water or volatile substance. 2. Percentage of Volatile Matters {including Water) destroyed by Incinera- ' It may be useful to give (from Page's Handbook, of Geological Terms) a few com- positions, and to define a few of the common mineralogical words used in geology. Quartz. — Crystallized silica. Ifelspar. — Silica, alumina (akiminnm trisilicate), potash, or soda, and a little lime, magnesia, and ferric oxide, crystallized or amorphous. Mica. — Silica, alumina, ferric oxide and potash, or magnesia, or lime, or lithia. Chlorite. — Mica, but with less silica and more magnesia and iron. Granite. — Composed of quartz, felspar, and mica. Syenite. — Hornblende instead of mica. Syeyiitio granite. — Quartz, felspar, mica, and hornblende. Gneiss. — Same elements as granite, but the crystals of quartz and felspar are broken and indistinct. Hornblende. — A mineral entering largely into granite and trappean rocks, composed of silica (47 to 60), magnesia (14 to 28), lime (7 to 14), with a little alumina, fluor- ine, and ferrous oxide. Augite. — Like hornblende, only less silica (does not resist acids). Hypersthene. — Like augite, only with very little lime ; it contains silica, magnesia, and iron ; resists acids. Greenstone. — Hard granular crystalline varieties of trap, felspar, and hornblende, or felspar and augite. Basalt. — Augite and felspar, olivine, iron pyrites, etc. Trap. — Tabular greenstone and basalt. Schist. — A term applied to the rocks mentioned above, when they are foliated or split up into irregular plates. Clay-Slate. — Argillaceous arenaceous rocks, with more or less marked cleavage. Limestone. — All varieties of hard rocks, consisting chiefly of calcium carbonate. Oolite. — Limestone made up of small rounded grains, compact or crystalline, like the roe of a fish. Chalk. — Soft calcium carbonate. Magnesian Limestone. — Any limestone containing 20 per cent, of a salt of magnesia, frequently not crystallized. < Dolomite. — Crystallized magnesian limestone. Kunkar. — A term used in India to denote nodular masses of impure calcium carbonate. Gypsum — Selenite. — Calcium sulphate. Gravel. — Water-worn and rounded fragments of any rock, chiefly quartz; size, from a pea to a hen's egs,. Sand. — Same, only particles less than a pea. Sandstone. — Consolidated sand ; the particles held together often by lime, clay, and ferric oxide. Freestone. — Any rock which can be cut readily by the builder ; usually applied to sandstone. Millstone grit. — Hard, gritty sandstone of the carboniferous series, used for mill- stones. Grit is the term generally used when the particles are larger and sharper than in ordinary sandstone. Clay. — Aluminum silicate. Greensand. — Lower portion of the chalk system in England ; sand colored by chlo- ritous iron silicate. Marl. — Lime and clay. Laterite. — A term much used in India to denote a more or less clayey stratum which underlies much of the sand in Bengal, some parts of Burmah, Bombay presi- dency, etc. Conglomerate. — Rocks composed of consolidated gravels (^'.e., the fragments water- worn and rounded). Breccia. — Rocks composed of angular (not water-worn) fragments (volcanic breccia, osseous breccia, calcareous breccia). Shale. — A term applied to all clayey or sandy formations with lamination ; it is often consolidated and hardened mud. 366 PEA.CTICAL HYGIENE. tion. — Take another weighed portion of soil and incinerate at a full red heat ; recarbonate with carbonic acid solution, or with ammonium car- bonate ; heat to expel excess of ammonia ; di-y and weigh. 3. Absorption of Water. — Place the dried soil in a still atmosphere, on a plate in a thin layer, and reweigh in twenty-foiu- hoiu*s ; the increase is the absorbed water. An equal portion of pure sand should be treated in the same way as a standaixl. It would be well to note the humidity of the air at the time. 4. Power of holding Water. — Thoroughly wet 100 grammes, drain off water as far as possible, and weigh ; the experiment is, however, not j^recise. 5. Snhstances taken xq) by Water. — This is important, as indicating whether di'inking- water is likely to become contaminated. Eub thoroughly 10 grammes in pvu-e cold water, filter and test for organic matter by chlor- ide of gold, or by evaporation and careful incineration ; test also for chlor- ine, sulphiu'ic acid, lime, alumina, iron, nitric acid. 6. Substances taken up by Hydrodiloric ylciV/.^WTiile water takes up alkahne chlorides and sulphates, nitrates, etc., the greater part of the lime, magnesia, and alumina are left undissolved. The quantity can be best de- termined by solution in pure hydi'ochloric acid. (a) To 40 grammes of the soil add 30 C.C. of pure hydrochloric acid, and heat; note effervescence. Add about 100 C.C. of water. Digest for twelve hours. T>vy and weigh the undissolved portion. (6) To the acid solution add ammonia. Alumina and oxide of iron are thrown down. Dry and weigh joreciiDitate. (c) To the solution filtered from {b) add ammonium oxalate. Diy ; wash and burn the calcium oxalate. Weigh as carbonate. {d) To the solution filtered from (c) add sodium phosphate. Collect ; dry and weigh (100 parts of the precipitate = 71) parts of magnesiuml car- bonate) ; or determine as pyrophosphate. The portion insoluble in hydrochloric acid consists of quartz, clay, and silicates of aluminum, iron, calcium, and magnesium. If it is wished to examine it further, it should be fused with three times its weight of sodium carbonate, then heated with dilute hydi-ochloric acid. The residue is silica. The solution may contain iron, hme, magnesia, and alumina. Test as above. 7. Iron. — Ii'on can be determined by the potassium dichromate, or by the permanganate. As the latter solution is used for other purposes, it is convenient to employ it in this case. Dissolve 10 gi-ammes of the soil in ptu-e hydrochloric acid fi'ee from iron by aid of heat Add a little pure zinc, and heat to convert ferric into ferrous salts. Poiu' off the solution from the zinc that is still undissolved, and determine iron by potassium permanganate ; i.e., heat to 140° and then drop in the solution of jjermanganate tiU a permanent but shghtly pink color is given. 1 C.C. = 0.7 milligramme of pvu-e iron.' 3Iicroscopic Examination. — Attention must now be paid to this, although it has not hithei-to been much studied. Bacteria of various kinds have been found, and they have been obsei-ved to be more numerous in the most hnpui'e and unhealthy soils, as might have been anticipated. Some forms, however, are beneficial, as it is under their influence that the oxida- tion (nitrification) of nitrogenous organic matte:: is carried on. Either samples of th soil itself may be examined, or the air may be dra^vNTi out of the soil at different depths by means of an aspu*ator. ' See Appendix A, Vol. 11. SOILS. 367 SECTION m. METHOD OF EXAMTXIXa A LOCALITY FOE MILITARY PURPOSES. A place sliould be seen at all times of the year, in the wet as well as m the drv seasons, in the autumn and "winter as well as in the spiing, and at night as well as by day. The following order will be found a con- venient one : — 1. Conformation. — Height above sea-level and elevation of hills above the plain. (Determine by mereinial bai'ometer or aneroid, or, if possible, get the heights fi'om an engineer. ) Angle of dechvity of hills ; amount of hill and plain ; number, course, and chai-aeters of valleys and ravines in hills ; dip of strata ; geological formation ; watei^heds and coui'ses ; ex- posure to winds ; situation, amount and chai-acter of winds ; sunlight, amount and diu'ation ; rain, amount and frecj^uency ; dust. 2, Coinposition. — lilineralogical characters. Presence of animal or vegetable substances ; amoiuit and characters. 3, Covering of soil by trees, bnishwood, gi-ass, etc. 4. Points for special Examination. — Amount of air ; of moisture. Height of subsoil water, at the wettest and driest seasons. Changes in level, and rapidity of change of subsoil or ground water. Condition of vegetable constituents ; examination of substances taken up by water, etc. Such a complete examination demands time and appai'atus, but it is quite necessary. A fail- opinion can then be formed ; but if a krge permanent station is to be erected, it is always desirable to recommend that a temporary sta- tion should be put up for a year, and an intelligent officer should be selected to observe the effect on health, to take meteorological observa- tions, and to examine the water at different times of the year. Some- times a spot more ehgible than that originally chosen may be found within a short distance, and the officer should be instructed to keep this point in view. The medical officer has nothing to do with mihtaiy considei-ations or questions of supply, but if he is able to suggest anything for the informa- tion of the authorities, he should of course do so. The opinion of Lind, whose large experience probably surpassed that of his contemporaries, and of our own time, should be remembered : — " The most healthy countries in the world contain spots of gTound where strangers are subject to sickness. There is hardly to be found any lai'ge extent of continent, or even any island, that does not contain some places where Euroj)eans may enjoy an uninteri-upted state of health dui'itig all seasons of the year." ' In choosing a site for a temporaiy camp, so elaborate an examination is not possible. But as far as possible the same rules should be attended to. There is, however, one difference — in a permanent station water can be brought from some distance ; in a temporeiry station the water supply must be near at hand, and something must be given up for this.^ The banks of rivers, if not marshy, may be chosen, care being taken to assign proper spots for watering, washing, etc. A river with marshy banks must never be chosen in any climate, except for the most imperative miLitai-y reasons ; it is better to have the extra labor of cai-rving water from ' Lind, Diseases of Europeans in Hot Climates. 4ttL edition, p. 200. "^ See remarks on this point, in the Eegnlations and Instructions for Encampments, p. 3. 368 PRACTICAL HYGIENE. a distance. A site under trees is good in hot countries, but brushwood must be avoided. SECTION IV. PREPARATION OF SITE FOR MILITARY PURPOSES. In any locahtv intended to be permanently used, the gi'ound should be drained with pipe di'ains. Even in the di'iest of the loose soils this is desu-able, especially in hot climates, where the rainfall is heavy. In im- permeable rocky districts it is less necessary. The size, depth, and dis- tance of the drains will be for the engineer to detennine ; but generally deep drains (■! to 8 feet in depth, and 12 to 18 feet apart) are the best. If there is no good fall, it has been proposed to drain into deep j)its ; but usually an engineer will get a fall ^^ithout such an expedient. A good outfall, however, should be a point always looked to in choosing a station. These di'ains are intended to carry off subsoil water, and not surface water. This latter should be proAided for by shallow drains along the natm-al outfalls and valleys. As far as drainage is concerned, we have then to provide for mere surface water, and for the water which passes below the sui-face into the soil and subsoil. Brushwood should usually be cleared away, but trees left until time is given for consideration. In clearing away binishwood, the gi'ound in the tropics should be distiu*bed as httle as possible ; and if it can be done, aU cleared spots should be soon sown with gi'ass. Bnishwood should not be removed from a marsh. In erecting the buildings, the ground should be excavated as little as possible ; in the trojDics esj^ecially hills should never be cut away. The surface should be levelled, holes filled in, and those poriions of the sur- face, on which rain can fall from buildings, well paved, -n-ith good side gutters. This is especially necessaiy in the troj^ics, where it is of im- portance to prevent the groimd under buildings from becoming damp ; but the same jDrinciples apply eveiwwhere. In a temporary camp so much cannot be done ; but even here it is de- sirable to trench and drain as much as jiossible. It not unfrequently hajD- pens in war that a camp intended to stand for two or three days is kept up for two or three weeks, or even months. As soon as it is clear that the occupation is to be at all prolonged, the same plans should be adopted as in peiTaanent stations. The great point is to carrs' off water rapidly, and it is astonishing what a few well-planned surface di-aius will do. The rules for imj^ro'sing the healthiness of a site may be thus sum- marized : — 1. Drain subsoil and lower the level of the gi'oiuid water. 2. Pave tmder houses, so as to prevent the au- from rising from the ground. 3. Pave or cover with shori grass aU ground neai' buildings in mala- rious districts. 4. Keep the soil from the penetration of impurities of aU kinds by proper aiTangements for carrying away rain, sui-face, and house water and house impuiities. End of Vol. I. A MANUAL PRACTICAL HYGIENE EDMUND A. PARKES, M.D., F.R.S. LATE PROFESSOR OF MILITARY HYGIENE IN THE ARMY MEDICAL SCHOOL ; MEIVIBEE OF THE GENERAL COUNCIL OP MEDICAL EDUCATION ; FELLOW OF THE SENATE OF THE UNIVERSITY OF LONDON ; EMERITUS PBOFESSOB OF CLINICAL MEDICINE IN UNIVERSITY COLLEGE, LONDON EDITED BY F. S. B. FRANgOIS DE CHAUMONT, M.D., F.R.S. FELLOW OF THE ROYAL COLLEGE OF SURGEONS OF EDINBURGH ; FELLOW AND CHAIRMAN OF COUNCIL OF THE SANITARY INSTITUTE OF GREAT BRITAIN ; PROFESSOR OF MILITARY HYGIENE IN THE ARMY MEDICAL SCHOOL FROM THE LAST LONDON EDSTBON WITH AN APPENDIX Giving the American Practice in Matters Relating to Hygiene PREPAllED BY AND UNDER THE SUPERVISION OF FREDERICK N. OWEN CIVIL AND SANITARY ENGINEER TWO VOLUMES IN ONE Volume II. NEW YORK WILLIAM WOOD & COMPANY 56 & 58 Lafayette Place 1884 COPYKIOHT WILLIAil WOOD &, COilPANY ItitSS TROW 9 PRINTING AND BOOKeiNDrNG COMPANY, HCW YORK. CONTENTS. BOOK I. — Continued. CHAPTER IX. PAGE Habitations 1 Section I. — General conditions of health 1 Mode of examining healthiness 3 Section II. — Hospitals 6 CHAPTER X. Removal of Excreta 16 Section I. — Amount of excreta 16 Section II. — Methods of removal 18 Sewers, 18 Removal by water 20 Influence of sewers on the death-rate of towns 41 Dry methods of removal 45 Comparison of the different methods 52 CHAPTER XI. Waeming of Houses 54 Section I. — Degree of warmth 54 Section II. — Kinds of warmth 55 CHAPTER XIL Exercise 60 Section I. — Effects of exercise 60 Section II. — Amount of exercise 70 Section III.— Training 73 CHAPTER XIII. Clothing 74 Materials of clothing 74 IV CONTENTS. CHAPTER XIV, PAGE Climate 80 Section I. — Temperature 83 Section II. — Humidity 87 Section III. — Movement of air ^9 Section IV. — Weight of air 89 Section V. — Composition of air (ozone, malaria) 93 Section VI. — Electrical condition— light 95 CHAPTER XV. Meteorology 96 Section I. — Thermometers 97 Section II. — Hysrrometers 103 Section III. — Barometer 106 Section IV.— Rain 113 Section V. — Evaporation 114 . Section VI.— Wind 115 Section VII. —Clouds 116 Section VIIL — Ozone 117 Section IX. — Electricity 118 Section X. — Thermometer stand 118 Section XI. — Weather 119 Section XII. — Diseases and meteorological conditions 119 CHAPTER XVI. Individual Hygienic Management 120 CHAPTER XVII. Disposal op the Dead 124 CHAPTER XVIII. On the Prevention of some Common Diseases 128 Section I. — Specific diseases — Paroxysmal fevers 129 Yellow fever 130 Dengue 133 Cholera 134 Typhus 140 Plague. 140 Enteric fever 141 Relapsing fever 1 41 Bilious remittent fevers : 143 Cerebro spinal meningitis 143 The eruptive fevers 143 Erysipelas 143 Hospital gangrene 143 CONTENTS. V PAGE Section II. — Non-specific diseases — Dysentery and diarrhoea 144 Liver diseases (Indian) 146 Insolation , 148 Phthisis 148 Scurvy 150 Military ophthalmia 153 Venereal diseases in the army 155 CHAPTER XIX. Disinfection and Deodoeization 161 Nature of the nontagia 163 The media in which the contagia are spread 165 Effects of heat as a disinfectant 166 Disinfecting chambers 167 Effects of chemical agents , 169 Purification of clothes 166, 169 Purification of the air by chemical methods 169 Purification of rooms after infectious diseases 173 Disinfection in various diseases „ 175 Exanthemata 175 Typhus 176 Plague 177 Enteric fever , 177 Cholera 177 Yellow fever 178 Dysentery 178 Cattle plague 179 Deodorization of sewage , 179 CHAPTER XX. Statistics , 185 Section I. — A few elementary points 185 Section II. — Army statistics 191 BOOK II. THE SERVICE OF THE SOLDIER. CHAPTER I. The Reckuit ... 195 CHAPTER IL Conditions under -which the Soldier is Placed 201 Section I. — Barracks at home 201 Barracks in hot climates 210 Wooden huts... , 216 War huts 216 Tents 218 Camps 232 Hospital encampment 226 VI COIfTENTS. PAGK Section II.— Food of the soldier 226 Section III. — Clothing of the soldier 234 Section IV. — Articles of clothing 237 Section V. — Equipments 243 Section VI. — Carriage of necessaries and armaments 249 Section VII.— Work of the soldier 253 Gymnastic exercises 254 Marches 258 Duty of medical officers during marches 266 Marching in India 268 Canada 26& CHAPTER IIL Effects of Military Service 270 Section I. — Loss of strength per annum 271 By death 271 By invaliding 285 Section II. — Loss of service from sickness 286 Section III. — General conclusions 290 CHAPTER IV. Foreign Service 29.3 Gibraltar 293 Malta 298 Cyprus 303 West Indies 303 Jamaica 307 Trinidad 310 Barbadoes 312 St. Lucia , . . 314 British Guiana 314 Bahamas and Hondui'as 316 Bermuda 316 North American stations 317 Canada 317 St. Helena 321 West Coast of Africa 321 Cape of Good Hope 325 Mauritius 327 Ceylon 330 India 333 China 358 CHAPTER V. Service on Board Ship , 361 Section I. — Transports for healthy troops 361 Section II. — Transports for sick troops 361 Section III. — Hospital ships 363 CONTENTS. Vll CHAPTER VI. PAQB War 365 Section I. — Preparation for war during peace 366 Section II. — Entry on war 369 Section III.— Actual war 370 Army medical regulations in war 370 Causes of sickness and mortality 371 Duties of sanitary officer 372 Hospitals in war 373 Sieges 379 Appendix .* 380 CONTENTS OF THE AMERICAN APPENDIX. Introduction 391 Water 400 The Characters and Distribution op American Soils 485 Cli&latology and Meteorology 443 Ventilation and Warming 465 Removal op House- Waste 475 Food Adulteration 503 DiSINPECTION AND DeODORIZATION 518 Vital Statistics 523 Some Hints to Sanitary Inspectors 524 INDEX 529 PRACTICAL HYGIENE ^00ll ^» (CONTINUED). CHAPTER IX. HABITATIONS. Whoever considers carefully the record of the mediseval epidemics, and seeks to interpret them by our present knowledge of the causes of disease, will surely become convinced that one great reason why those epidemics were so frequent and so fatal was the compression of the population in faulty habitations. Hi-contrived and closely packed houses, with narrow streets, often made winding for the purpose of defence ; a very poor supply of water, and therefore a universal uncleanliness ; a want of all appliances for the removal of excreta ; a population of rude, careless, and gross habits, living often on innutritions food, and frequently exposed to famine from their imperfect system of tillage, — such were the conditions which almost throughout the whole of Europe enabled diseases to attain a range, and to display a virulence, of which we have now scarcely a con- ception. The more these matters are examined, the more shall we be convinced that we must look, not to grand cosmical conditions ; not to earthquakes, comets, or mysterious waves of an unseen and poisonous air ; not to recondite epidemic constitutions, but to simple, familiar, and household conditions, to explain the spread and fatahty of the mediseval plagues. SECTION I. GENERAL CONDITIONS OF HEALTH. The diseases arising from faulty habitations are in great measure, per- haps entirely, the diseases of impure air. The site may be in fault ; and from a moist and malarious soil excess of water and organic emanations may pass into the house. Or ventilation may be imperfect, and the ex- halations of a crowded population may accumulate and putrefy ; or the excretions may be allowed to remain in or near the house ; or a general uncleanliness, from want of water, may cause a persistent contamination Vol. II.— 1 2 PRACTICAL HYGIENE. of the air. And, on the contraiy, these five conditions insure healthy habitations : — 1. A site diy and not malarious, and an aspect which gives Hght and cheerfulness. 2. A system of ventilation which carries off all respiratory impurities. 3. A system of immediate and perfect sewage removal, which shall render it impossible that the aii' shall be contaminated from excreta. 4. A pure supph' and proper removal of water ; by means of which perfect cleanliness of all parts of the hovise can be insured. 5. A condition of house construction which shall insvu'e perfect dryness of the foundation, walls, and roof. In other words, perfect purity and cleanliness of the air are the objects to be attained. This is the fundamental and paramount condition of health}' habitations ; and it must override aU other conditions. After it has been attained, the architect must engraft on it the other conditions of comfort, convenience, and beauty. The inquiries which have been made for the last forty years in England have sho-oTi how badly the poorer classes are lodged, both in town and countiy, and how urgent is the ^necessity for improvement. Vai-ious Acts' have been passed for the purjDOse of improving laborers' cottages and other small dwellings, but either from the powers being insufficient, or from the difficulty of proving that a dwelling is injurious to health, unless it is in extremely bad condition, these Acts have had only partial effect. Uj^ to a certain point, there is no difficulty in insuring that a small house shaU be as healthy as a large one. The site and foundations can be made as diy, the drains as well arranged, the walls and roofs as sound, and the water supply as good as a house of much lai'ger rental. In fact, in one respect, the houses of the poor are often superior to those of the rich, for the sewers do not open directly into the houses, and sewer air is not breathed during the night. But the difficulty in the houses of the poor is the overcrowding, and the impregnation of the AvaHs with foul ef- fluria and deposits. Considerations of cost wiU probably always prevent our poor class of houses from ha'sing sufficient floor and cubic space. These two special difficulties must be met by improved means of warming and ventilation, and by covering the interior walls with a cement which is non-absorbent, and which can be washed. Perhaps, also, imj^rovements in using concrete, or other plans, "will eventually so lessen the cost of build- ing that larger rooms can be given for the same rental, and the poor be taught to prize the boon of an abimdant allowance of air, and not seek to lessen it by crowding and tmderletting. Dr^mess of the foundation and walls of a house is secured by draining the subsoil, 4 to 9 feet below the foundation,' and, in very wet clay soil, by pacing or cementing under the enth'e house. ^ The walls are kept diy by being embedded in concrete, which is brought up to the ground level, or by the insertion in the walls themselves of a waterproof course of slate, ' Laboring Classes Dweiiing-house Act, 1866 ; An Act to provide better Dwellings for Artisans and Laborers, 1868 ; Artisans Dwellings Act, 1875 ; various clauses in the different Public Health Acts. ■■' Even the walls of old rickety cottages may be thoroughly dried by this means (Rogers Field). ^ For a good diagram of a plan for avoiding damp, see Bailey Denton's Sanitary En- gineering, Plate I., p. 56. HABITATIOITS. 3 asphalt, or, what is better, of ventilating vitrified thin bricks (as devised by IVIi-. Taylor). On wet damp soils, when a house has no cellar, the flooring ought to be raised 2 feet above the ground, and the space below should be well ven- tilated. In the tropics, the houses are often raised on arches 3 to 5 feet above the ground. If this plan were universal, it would vastly improve the health of the community. Dryness of walls is best secured by hollow walls, ^ or coating the walls vd.th cement, which is kept painted, or with slates. Terra-cotta slabs have been used, and liquid preparations (chiefly alkaline sihcates) have been brushed over the surface of brick and stone. Bricks are often extremely porous," and a brick wall will absorb many gal- lons of water. ^ Dryness of the roof should be carefully looked to in every case, as water often gets to the walls through a bad roof, and the whole house be- comes damp. The condition of the basements or cellars, if they exist, requires atten- tion, as the air of the house is often drawn dii-ectly from them. They should be dry, and thoroughly well ventilated, and the house pipes, if they run down to the basement, should be always uncovered so as to be easily inspected, and any bad-fitting joint, or crack, or imperfect trap, if there be one inside the house, be at once remedied. The carrying off of rain water, so as not to sinlc into the ground near the house, is a matter of importance. The other points which are necessary to secure a healthy house are discussed in their resjDective chapters. In examining a house to discover the sources of unhealthiness, it is best to begin at the foundation, and to consider first the site and base- ments, then the living and sleeping rooms (as to size, cubic contents, and number of persons, and condition of walls and floors), ventilation, water supply, and plans of waste and sewer-water removal, in regular order. The following memorandum as to the way in which engineers examine a house has been kindly fui-nished by IVIr. WilUam Eassie, C.E. : — IHEM0KA2TDIIM. What is usually done by Sanitary Engineers ichen inspecting a House. Sanitary engineers consider that an unusual smell is generally the first evidence of something wrong, and that, traced to its source, the evil is haK cured. They inspect first the drainage arrangements. If the basement generally smells offensive^, they search for a leaking drain-pipe, i.e., a pipe badly jointed or broken by settlement, and these will often show them- selves by a dampness of the paving around. If, upon inquiry, it turns out that rats are often seen, they come to the conclusion that the house drain is in direct communication with the sewer, or some old brick barrel-drain, ' Jenning's patent Bonding Brick is a good plan for preventing moisture penetrat- ing from the outer to the inner skin of a hollow wall. It is a hollow, vitrified brick, curved upward at an angle of 45°, so that no water can pass along it. •^ An ordinary brick will hold about 16 oz. of water. ' Bricks imperfectly burned on the outside of the kiln are termed Place, or Samel, or Sandel bricks. They absorb much water. The sun-dried bricks of India are very damp, and absorb water from the air. Many sandstones are very porous ; water beats into them and rises high by capillary attraction. Lime made from chalk absorbs water. Piso is compressed earth, and, unless covered with cement, is moist. 4 PEACTICAL HYGIENE. and therefore examine the traps and lead bends which join the drain-pipes to see if they are gnawed or faulty. If the smell arises from any j^articu- lar sink or traji, it is plain to them that there is no ventilation of the drain, and more especially no disconnection between the house and the sewer, or no flap-trap at the house-drain delivery into the sewer. If a country house be under examination, a smell at the sink will, in nearly every case, be traced to an unventilated cesspool ; and, in opening up the drain undei the sink, in such a state of things, they will take care that a candle is nol brought near, so as to cause an explosion. If the trap is full of foul blact water, impregnated with sewer air, they partly account for the smell by the neglect of flushing. If the sink, and kitchen, and scullery wastes are in good order and the smell is still obsen'able, they search the other cellar rooms, and frequently find an old floor-trap without water, broken and open to the drain. If the smell be ammoniacal in character, they trace the stable-drains and see if they lead into the same pit, and if so, argue a weak pipe on the route, especially if, as in some London mansions, the stable-drains run from the mews at the back, through the house to the front street sewer. Should a bad persistent smell be complained of mostly in the bedroom floor, they seek for an untrapped or defective closet, a burst soil-jnj^e, a bad junction between the lead and the cast-iron portion of the soil-pij^e behind the casings, etc., or an improj)er connection with the drain below. They will examine how the soil-pipe is jointed there, and, if the joint be inside the house, will carefully attend to it. The}' will also remove the closet framing, and ascertain if any filth has overflowed and saturated the flooring, or if the safe underneath the apparatus be full of any liquid. If the smell be only occasional, they conclude that it has arisen when the closet handle has been lifted in ordinary use or to empty slops, and satisfy themselves that the soil-pipe is unventilated. They, moreover, examine the bath and lavatoiy waste-pipes, if they are untrapj^ed, and if trapped by a sigmoidal bend, whether the trapping water is not always withdrawn owing to the siphon action in the full running pipe. They Avill trace all these water-pipes down to the sewer, ascertain if they wrongly enter the soil-pipe, the closet-trap, or a rain water-pipe in connection with the sewer. If the smell be perceived for the most part in the attics, and, as they consider, scarcely attributable to any of the foregoing evils, they will see whether or not the rain water pipes which terminate in the gutters, are soleh- acting as drain ventilators, and blowing into the dormer windows. They will also examine the cistei^ns of rain Avater, if there be any in the other portions of the attics, as veiy often they are full of piitridity. A slight escape of impure air from the drains may be difiicult to detect, and the smell may be attributed to want of ventilation, or a comphcation of matters may arise from a slight escape of gas. Neither are all danger- ous smells of a foul natui-e, as there is a close sweet smell which is even worse. Should the drains and doubtful places have been previously treated by the inmates to strongly smelling disinfectants, or the vermin killed by j^oison, the insjjectors of nuisances will find it difiicult to separate the smells. In such a case, however, they will examine the state of the ground under the basement flooring, and feel certain that there are no dis- used cesspools or any sewage satui'ation of any sort. They will also ascer- tain if there be any stoppage in the drain-pipes, by taking up a yard trap in the line of the drain march, and noting the reappearance of the lime water which they had thrown down the sinks. Arid invariably, after ef- HABITATIONS. 5 fecting a cirre for any evil wliicli lias been discovered, tliey will leave the traps cleaned out and the drains well flushed. A thoroughly drained house has always a disconnection chamber placed between thS house drain and the sewer or other outfall. This chamber is formed of a raking siphon, and about two feet of oj^en channel j)ipe, built around by brickwork and covered by an ii'on man-hole. Fresh air is taken into this chamber by an open gi'ating in the man-hole, or by an under- ground pipe, and the air thus constantly taken into the chamber courses along inside the drain, and is as continuously discharged at the ventilated continuations of the soil-pipes, which are left untrapped at the foot, or at special ventilating j^ipes at each end of the drain. This air current in the drain prevents all stagnation and smell. When a house is undergoing examination, it is mse to test for lighting gas leakages, and there is only one scientific method of doing so, which is as follows : — Eveiy burner is plugged up, save one, and to that is attached a tube in connection with an air force-pump and gauge— the meter having been previously disconnected. Air is then pumped into the whole system of pipes, and the stop-cock turned, and if, after working the pump for some time, and stopjDing it, the gauge shows no sign of sinking, the pipes may be taken as in safe condition ; but if the mercury in the gauge falls, owing to the escape of air from the gas-tubes, there is a leak in them, which is dis- coverable by pouring a Httle ether into the pipe close by the gauge, and re- commencing pumping. Very minute holes can be detected by lathering the pipes with soap and water, and making use of the pump to create soap bubbles. Besides the drainage, they ^vill, especially if they detect a bad and dank smell, see if it arises from the want of a damp-proof course or of a dry area, see if there be a wet soil under the basement floor, a faulty pipe inside the wall, an unsound leaden gutter on the top of the wall, or an ovei'flowing box gutter in the roof, a leaky slatage, a porous wall, a wall too thin, and so on. They will also keep an eye upon the condition of the ventilating ar- rangements, and whether the evils complained of are not mainly due to defects there. The immediate surroundings of the house "^ill also be noted, and any nuisances estimated. S mitary inspectors, whilst examining into the condition of the drains, always examine the water cisterns at the same time, and discover whether the cistern which yields the drinking water supplies as well the flushing water of the closets. They will also ascertain if the overflow pipe of this cistern, or of a separate drinking water cistern, passes directly into the di'ain. If the overflow pipe be siphon-trapped and the water rarely changed in the trap, or only when the ball-cock is out of order, they vrill point out the fallacy of such trapping ; and, speaking of traps generally, they will look suspiciously on every one of them, endeavor to render them supererogatory by a thorough ventilation and disconnection of the drains.^ ' Much useful information -svill also be obtained from Sanitary Arrangements for Dwellings, by W. Eassie, C.E., and from Sanitary Engineering, by J. Bailey Denton, C.E. See also Tlie Habitation in Eelation to Health, by F. de Chaumont, Christian Knowledge series; Our Homes, and how to keep them Healthy, Cassell, Fetter & Galpin. 6 PRACTICAL HYGIENE. SECTION n. HOSPITALS. General Remarks. Of late years a great number of works (English, French, German, and American) have been written on the construction of hospitals. This has been especially owing to the celebrated Notes on Hosjyitals, pubHshed by Miss Nightingale, after the Crimean war — a work the importance of which it is impossible to over-rate — and to the very useful pamphlets of Mr. Roberton, of Manchester. Among military writers, Robert Jackson in this, as in all other points, takes the first rank, and his observations on the con- struction of hospitals are conceived entii'ely in the sjiirit of the best writings of the present day. In the short space wliich can be given to the subject here, we can merely condense what has been best said on the subject, as applied especially to military hospitals. ' In the first place, however, a few words are necessary on the general question. Although the establishment of hospitals is a necessity, and marks the era of an advanced civilization, it must always be remembered that if the crowd- ing of healthy men has its danger, the bringing together within a confined area many sick persons is far more jDerilous. The risks of contamination of the air, and of impregnation of the materials of the building with morbid substances, are so greatly increased, that the greatest care is necessary that hospitals shall not become pest-houses, and do more harm than good. We must always remember, indeed, that a number of sick persons are merely brought together in order that medical attendance and nursing may be more easily and perfectly performed. The risks of aggregation are encountered for this reason ; othei'wise it would be far better that sick persons should be separately treated, and that there should be no chance that the rapidly changing, and in many instances putrefying stxbstances of one sick body should pass into the bodies of the neighboring patients. There is, indeed, a continual saci'ifice of life from diseases caught in, or aggravated by hos- pitals. The many advantages of hospitals more than counterbalance this sacrifice, but it should be the first object to lessen the chance of injury to the utmost. The risk of transference or aggravation of disease is least in the best ventilated hospitals. A great supply of air, by immediately dilute ing and rapidly carrying away the morbid substances evolved in such quantities from the bodies and excretions of the sick, reduces the risk to its minimum, and perhaps removes it altogether. But the supply of air must be enormous ; there must be a minimum of not less than 4,000 cubic feet per head per hour for ordinary cases ; and the sujDply must be practically unlimited for the acute and febrile diseases. The causes of the greater contamination of the air of hospitals are these : — ' For fuller details, Captain Galton's work on Hospitals sliould be consulted. See also Five Essays on Hospital Plans, contributed for the Joljns Hopkins Hospital Scheme (Wood & Co., New York); Report on the Manchester Royal Infirmary, by J. Netten Radcliffe, Esq. ; Reports on St. Mary's Hospital, Paddington, by F. de Chaumont, M.D ; chapter in Roth and Lex, Milit. Gesundheitspflege ; paper in the Practitioner, March, 1877; article "Hospital," Encyclopaedia Britannica, 9th edition; Das Allgemeine Krankenhaus der stadt Berlin im Friedrichshain, von A. Hagemeyer, Berlin, 1879. HABITATIONS. 7 1. More organic effluvia are given off from the bodies and excretions of sick men. These are only removed by the most complete ventilation. 2. The medical and surgical management of the sick necessarily often exposes to the air excretions, dressings, foul poultices, soiled clothes, etc., and the amount of substances thus added to the aii- is by no means incon- siderable, even w^ith the best management. 3. The vsralls and floors of hospitals absorb organic matters and retain them obstinately, so that in some cases of repeated attacks of hospital gangrene in a ward it has been found necessary to destroy even the whole wall. Continual drippings on the floor of substances which soak into the boards and through cre^dees, and collect under the floor, also occiir, and thus collections exist of putrefying matters which constantly contaminate the air. 4. The bedding and furniture also absorb organic substances, and are a great cause of insalubrity. 5. Till very recently, even in the best hospitals, the water-closets and urinals were badly arranged, and air passed from these places into the wards. In addition to the necessary amount to dilute and remove these sub- stances, the freest supply of air is also now known to be a curative means of the highest moment ; in the cases of the febrile diseases, both specific and symptomatic, it is indeed the first essential of treatment ; sometimes, es- pecially in typhus and small-pox, it even lessens dviration, and in many cases it renders convalescence shorter. ^ There can be no doubt, that the necessity for ah unlimited supply of air is the cardinal consideration in the erection of hospitals, and, in fact, must govern the construction of the buildings. For many diseases, es- pecially the acute, the merest hovels with plenty of air are better than the most costly hospitals without it. It is ill-judged humanity to overcrowd febrile patients into a building, merely because it is called a hospital, when the very fact of the overcrowding lessens or even desti'oys its iisefulness. In times of war, it should never be forgotten by medical officers that the rudest shed, the sHghtest covering, which wiU. j^rotect from the weather, is better than the easy plan so often suggested and acted on, of putting the beds a little closer together. The recognition that the ample supply of pure air is the first essential of a good hospital, led Miss Nightingale to advocate with so much energy and success the view which may be embodied in the two following rules : — 1. The sick should be distributed over as large an area as possible, and each sick man should be as far removed as possible from his neighbor. 2. The sick should be placed in small detached and perfectly ventilated buildings, so that there should be no great number of persons in one building, and no possibihty of the polluted air of one ward passing into another. How is this perfect Purity of Air to be secured? This is a matter partly of construction, partly of superintendence. {a) There should be detached buildings, so disposed as to get the freest 4ir and the greatest light. They should be at considerable distances apart, so that 1,000 sick should be spread like a village ; and in the wards each ' For examples of the value of a great supply of fresh air on some diseases, see note in former editions of this work. 8 PRACTICAL HYGIENE. man ought to have not less than 100, if possible 120, feet of superficial, and from 1,500 to 2,000 feet of cubic space. With detached buildings, the size of a hospital, as pointed out by Miss Nightingale, is dependent merely on the facihty of administration. When the hospitals consist of a single building the smallest hospitals are the best. (b) The ventilation should be natural, i.e., dependent on the movement of the outer air, and on inequalities of weight of the external and internal air. The reason of this is, that a much more efficient ventilation can be obtained at a cheaper cost than by any artificial means. Also, by means of open doors and windows, we can obtain at any moment any amount of ventilation in a special ward, whereas local alterations of this kind are not possible in any artificial sj'stem. The amount of air, also, which any arti- ficial system can cheaply give is comparatively limited. The amount of air should be restricted only by the necessity of not allowing its movement to be too perceptible. The best arrangements for natural ventilation for hospitals appear to be these — 1st. Opposite windows reaching nearly to the ceihng, on the sides of a ward (not wider than 24 feet, and containing only two rows of beds) and a large end window. 2d. Additional openings, to secure, as far as possible, a vertical movement of the air from below upward ; and this will be best accomj^lished as follows : ' — A tube opening at once to the external air should run transversely along the floor of the ward to each bed, and should end in a box placed under the bed, and provided with oj^enings at the top and sides, which can be more or less closed. In the box, coils of hot- water pipes should be in- troduced to warm the air when necessary. The area of the tube should not be less than 72 square inches to each bed ; and the area of the open- ings in the box at least four times larger. The fresh air, warmed to any degree and moistened, if necessary, by placing wet cloths in the box, or medicated by placing chlorine, iodine, or other substances, will then pass under each bed, and ventilate that sjiace so often unaired ; and then, as- cending round the sides of the bed, will at once dilute and carry up the products of respiration and transpiration to the ceihng. It would be a simple matter so to arrange the hot-water pipes as to be able to cut off all or some of the pipes under a particvilar bed from the hot-water cur- rent if desired, and so to give a fever patient air of any temperature, from cold to hot, desired by the physician. In the low and exhausted stages of fever warm air is often desii*able. By this simple plan, we could deal more effectually with the atmosphere round our patients, as to warmth, dryness, humidity, and medication, than by any other. At the same time, the open fire- place and chimney, and the open doors and windows, might be preserved.^ For the exit of the foul air, channels in the ridge sliould be provided, warmed by gas if possible. To facilitate this system of ventilation, it is desirable to have the build- ings one-storied only ; but it can be applied with two stories. Only then the discharge tubes must be placed at the sides, and run up in the thick- ness of the walls. ^ 1 A plan similar to this has been devised by Dr. S. Hale, and adopted in some of the Australian hospitals. It is an excellent arrangement, bnt seems rather unneces- sarily complicated by taking the air under the floor, and elevating the beds on a dais. '■' The introduction of vertical tubes is also useful, as giving the air an uj^ward di- rection and allowing a considerable supply without draughts. ^ When the ceiling is flat the outlets may be advantageously placed at the sides close to the ceiling, but with a one-storied or upper ward an open roof is better. HABTTATIOlSrS. 9 But not only should there be good ventilation, but the wards ought to be every year empty for two or three weeks, and during the time thoroughly exposed to the air, every door and window being open. (c) The strictest rules should be laid down with regard to the imme- diate removal from the wards of all excreta, dirty dressings, foul linen, etc. Nothing that can possibly give off anything to the air should be allowed xo remain a single moment. Dressings of foul wounds should be sprinkled with deodorants. (d) The walls should be of impermeable material. Cements of different kinds are now vised, especially Parian ; large slabs of properly colored tiles, joined by a good cement, and good Portland cement well painted, would, however, be better. Pai-ian cracks and spaces form behind it. Ceiling should be either cemented or frequently limewashed. Great care should be taken with the floors. On the whole, good oak laid on concrete seems the best material ; but the joinings should be perfect, so that no fluid may pass through and collect below the floor. Possibly it might be well to cover the floor with a good oil-cloth, or material of the like kind, which would prevent substances from sinking into the boards, and would lessen the necessity of washing the floors, but might be itself removed, and Fig. 69. — Ward for Twenty Ward-beds. A, ward ; B, nurse's-room, with warJ-window ; C, scullery ; D, water-closet and ward-sink ; E, bath-room and abhition-room ; F, ventilated lobbies. frequently washed. The practice of waxing and dry-rubbing the floors, and other similar plans, is intended to answer the same purpose. Dr. Langstaff, of Southampton, strongly recommends solid paraffin. The paraffin is melted and then poured on the floor, and ironed into it with a box-iron, heated from the interior by burning charcoal ; it penetrates about a quarter of an inch into the wood. The excess of paraffin is scraped off, and the floor is brushed Avith a hard brush ; a little paraffin in turijentine is then put on, and the flooring is good for years.' (e) The furniture in a ward should be reduced to the minimum ; and as far as possible, everything should be of iron. The bedding should also be reduced in size, as much as can be. Thick mattresses should be discarded, and thin mattresses, made easy and comfortable by being placed on springs, employed.^ The material for mattresses should be ' An experience of some years in the Southampton Infirmary has proved the advan- tage of this fiiooring. It has also heen introduced with satisfactory results into the Bris- tol Infirmary, according to information received from Mr. Eassie, C.B. '■' The wire mattress bedstead, as arranged by Dr. Reed, in use in the Manchester Royal Infirmary, and made by Messrs. Chorlton & Dugdale, seems an excellent and very comfortable form. 10 PRACTICAL HYGIENE. horse-hair (18 lb weight to each mattress), or coir fibre, which, on the whole, are least absorbent. Straw, which absorbs veiy little, is bulky, and is said to be cold. All flock and woollen mattresses should be discarded. Blankets and coverlets should be white or yellowish in color, and should be frequently thoroughly aired, fumigated, and washed. (/) The arrangement of the water-closets and urinals is a matter of the greatest mo- ment. Ever}^ ward should have a urinal, so that the common practice of retaining urine in the utensils may be discontinued. If the urine is kept for medical inspec- tion, it should be in closed vessels. The removal of excreta must be by water. In hospitals, nothing else can be depended upon, as regards certainty and ra2:)idity. The best arrangement for closets is not the handle and plug, whicth very feeble patients will not lift ; but a self-acting water supply connected Avith the door, and flowing when it is open. This plan is better than the self-acting spring seat. Fig. 70.— Section of Ward to show the Bed. Fig. 71. — Dran-ing to show Beds and Windows. which is not always easily depressed by a thin patient ; and also, by leaving the open door, it gives us the means of pouiing in any quantity of water, and of thoroughly flushing the pan and pipe. The closets are best arranged in nearly detached lobbies, at one end of the ward, and separated from it by a thorough cross ventilation, as shown in the plan which is cop- ied from jNIiss Nightingale's work. ' A further imjorovement may be made by thro-tting the closets still further out, with an intercepting lobby, as shown in Fig. 72. Li this way, provided the site of the hospital is originally well chosen, perfect purity of air can be obtained, and the first requisite of a good hospi- tal is secured. Next to the supply of pure air, and to the measures for preventing contamination (which em- brace construction, ventilation, cleanliness, and la- trine arrangements), come the arrangements for medical treatment. Medical treatment includes — 1. Supply of Food. — The diet of the sick is now becoming a matter of scientific precision ; and it is probable that every year greater and greater importance will be attached to it. Hence the necessity of a perfect central kitchen, and of means for ' Dr. Buchanan has suggested a plan of vertical ventilation in the vestibule, in cases where cross ventilation is not available. Tliis, of course, need not to be in a new building, although it might be useful in the adaptation of an existing one. The addition of a slop sink, for the emptying of bed-pans, etc., would also be useful. WARD Fig. 72.— Closets (W. C.) and Lavatory (L.) with inter- vening ventilated lobbies (/.). HABITATIONS. 11 the rapid supply of food at all times. There is more difficulty in doing this than at first appears, as the central kitchen cannot supply everything ; and yet there must be no cooking in the wards, or even near them, as the time of the attendants should be occupied in other ways. Probably the best arrangement is to have hot closets close to the wards, where the food sent from the kitchen can be kept warm, and ready for use at all hours of the day and night. 2. The Supply of Water. — ^Hot and cold water must be supplied every- where, and baths of all kinds should be available. The supply of water for all purposes shoald be 40 to 50 gallons per head daily. 3. The Supply of Drugs and Apparatus. — The chief point is to econo- mize the time of attendants, and to enable drugs and apparatus to be pro- cured without delay when needed. 4. The Nursing and Attendance, including the Supply of Glean Linen, etc. — The time and labor of the attendants should be expended, as far as pos- sible, in nursing, and not in other duties. Every contrivance to save labor and cleaning should therefore be employed. Lifts, shafts, tramways, and speaking-tubes to economize time ; wards arranged so as to allow the attendants a view of every patient ; wards not too large nor too small, for Miss Nightingale has conclusively shown that wards of from 20 to 32 beds are best suited for economy of service. 5. Means of Open-air Exercise for Patients. — This ought properly to be considered as medical treatment. As soon as a patient can get out of his ward into the open air he should do so ; therefore, open verandas on the sunny sides of the wards, and sheltered gardens, are most important. For the same reason hospitals of one story are best,' as the patients easily get out ; if of two stories, the stairs should be shallow. 6. In addition to all these, the supply of air medicated with gases, or fine powders, or various amounts of watery vapor, is a mode of treatment which is sure to become more common in certain diseases, and special wards will have to be provided for these remedies. The parts of a military hospital are'^ — Patients' Rooms, Wards, and Day-rooms, if possible ; the wards of two sizes, — large, i.e., from 20 to 32 beds, and small, for one or two patients. It is desirable to have the small wards not close to the large ones, but at some little distance. Attached to the wards are attendants' rooms, scul- lery, bath and ablution rooms, small store-room, urinal, closets (one seat to eveiy eight men). Operating-room — Dead-house — Administration. — Surgeons' rooms ; case- book and instrument room ; offices and officers' room. Pharmacy. — Dispensary ; store-room ; dispenser's room. ' The late Dr. Parkes wrote : — "I had never properly estimated the Importance of patients getting into the air, and the desirability of one-storied buildings for this pur- pose, till I served at Renkioi, in Turkey, during the Crimean war. The hospital was composed of one-storied wooden houses connected by an open corridor. As soon as a man could crawl he always got into the corridor or between the houses, and the good effects were manifest. Some of the medical officers had their patients' beds carried out into the corridor when the men could not walk. In the winter greatcoats were pro- vided for the men to put on, and they were then encouraged to go into the corri- dor." ^ Hospital space is to be provided for 10 per cent, of the force. Lately, since the health of the army has been so much improved on home service, it has been proposed to reduce it to 7 per cent., but it would appear desirable always to have a large hos- pital space for emergencies and for war. For the duties of administrative medical officers with regard to hospitals, see the Medical Regulations, 1878. 1^ PRACTICAL HYGIENE. Culinary. — Store-room ; wine and beer room ; larder and meat room ; kitchen ; room for arranging diets ; scullery ; cook's room. Ifas/an^.— Waslihouse ; diiiy linen store ; baking and fumigating room ; cleaning room for mattresses. Steward's Department— O^ces, furniture, linen, utensil, and pack stores ; rooms for cleaning. "" " '^-"-^ — ^M O to >.2 The amoTint for storage room is, for an hospital of 100 sick — Fuel store = 250 square feet. Foul linen store =120 " Pack store = 200 " (In military hospitals.) Fig. 73 shows the arrangement of closets and lavatory in a mihtary hospital Bedding and store = 200 square feet. Clothing store =100 " Utensil store = 160-200 " Provision store = 100 " HABITATIONS. 13 The two following plans show the arrangement of the Lariboisiere Hospital in Paris,' which circumstances have made the type of the so- called "block or pavihon plan ; and of the Herbert Hospital, which is the best mihtary hospital in this country, or perhaps anywhere. The Herbert Hospital at Woolwich consists of fovir double and three single pavihons of two floors each, all raised on basements. There is a convalescents' day-room in the centre paviUon. The administration is in a separate block in front. The axis of the wards is a Uttle to the east of north. There is a corridor in the basement, through which the food, medicines, coals, etc., are conveyed, and then, by a series of lifts, elevated to the wards. The terraces in the corridor afford easy means of open-air exercise for the Fig. 74. — Lariboisiere Hospital at Paris. patients in the upper ward. The wards are warmed by two central open fire-places, vrith descending flues, round which are air-passages, so that the entering air is warmed. The floors are iron beams, filled in with concrete, and covered with oak boarding.* The usual shape of ward is oblong, the standard vridth 26 feet (in the army) to 30 feet (St. Thomas's, for instance), and the length being deter- mined by the number of beds. Mr. John Marshall ^ has, however, advo- cated a system of circular wards, which he thinks have certain advantages, ' The new Hotel-Dieu is on the same general plan. ^ The arrangement of the pavilions may be varied in many ways ; for different forms of arrangement, see the works already cited. It has been thought unnecessary to take up space by inserting plans, which vary merely in detail. 3 On a Circular System of Hospital Wards, by John Marshall, F.R.S., etc. London, Smith & Elder, 1878. 14 PRACTICAL HYGIENE. and a similar plan has been actually can-ied out in the new hospital at Antwerp, which will probably be ready for occupation by the end of this year (1882).' Hospitals in the Tropics. The Barrack and Hospital Commission, in caiTjdug out the plans of the Royal Indian Sanitary Commission, suggest'^ for each sick man — Supei-ficial area = 100 square feet, up to 120 in unhealthy districts. Cubical space — 1,500 feet, or, in unhealthy districts, 2,000 feet. It is also directed that hospitals should consist of two divisions — 1st, for sick ; and 2d, for convalescents. This latter division to hold 25 per cent, of the total hosj^ital inmates. ' ■JSea.Za 'of rest Fig. 75. — Ground Plan of the Herbert Hospital, Woolwich (from Miss Nightingale's book). Each hospital is to be built in blocks, to consist of two floors, the sick and convalescents to sleep on the upper floors only ; each block to hold only 20 to 24 beds. The principles and details are, in fact, identical with those already or- dered for the home stations. Hospitals for Infectious Diseases. Fever and small-pox hospitals have been long established in many large English towns ; but within the last few years it has become usual for all towns of any size to put up some temporary hospitals during an outbreak of cholera, small-pox, relajjsing fever, and typhus, and to remove persons ill with these diseases at once from their dwellings. In this way, if there is early discovery of the cases, the chances of spread of the disease are greatly lessened.^ ' British Medical Journal, August 26, 1882, on p. 350 a ground plan is given ; see also London Medical Record, July 15, 1881, p. 296 ; and Charitable and Parochial Es- tablishments, by Saxon Snell, F.R.I.B.A., for similar plans. * Op. cit., p. 27. ^ That such hospitals may, however, be themselves centres of infection has been shown by the Report of the Hospitals Commission, 1882, which may be consulted for much valuable iiiformation. HABITATIOIS^S. 15 Tlie Medical Department of the Privy Council issued a Memorandum in 1872,' pointing out that power is given under the 37th section of the Sanitary Act, 1866,^ to the local board, improvement commissioners, town council, or vestry, to provide "hospitals or temporary places for the recep- tion of the sick." It is pointed out that villages should have the means of accommodating instantly four cases of infectious disease in at least two separate rooms, and it is considered that a good cottage would answer this purpose. In towns a permanent provision is advised to be made, and the following suggestions are made : — The situation to be convenient ; ward cubic space, 2,000 feet per head ; ward floor-space per head, 144 square feet ; good provision for ventilation ; precautions against entrance of foul air (as from privies or sinks) ; warming in winter to 60° Fahr. ; keeping cool in summer ; means of disposal of excrements and slops ; and for clean- ing and disinfecting linen. For temporary emergencies, tents (army hospital marquees) are recom- mended, or huts are advised. The huts are described at some length, and plans are given of the huts and of the arrangement. As these are very similar to those used by the army in war, reference is made to that section. * Memorandum on Hospital Accommodation to be given by Local Authorities (signed John Simon, July 8, 1872). ^ Now under the 131st and following clauses of the Public Health Act of 1875. CHAPTER X. REMOVAL OF EXCRETA. We have seen that a regulai* supply of pure aii' — in other words, efficient ventilation — is requu-ed to remove the excreta of the lungs and the volatile products of the skin. The sohd and fluid excreta from the bowels and the kidneys ought to be as rapidly and as completely removed as the gaseous impurities. It is highly probable that to barbarous and inefficient modes of remov- ing the excreta of men and of animals we must partly trace the gi-eat prev- alence of disease in the middle ages, and there is no doubt that many of the diseases now prevaihng in our large towns are owing to the same cause. When men hve in thinly populated countries, following, as they will then do, an agricultural or nomade life, they will not experience the conse- quences of insufficient removal of excreta. The sewage matter returns at once to that great deodorizer the soil, and fertilizing it, becomes a benefit to man, and not a danger. It is only when men collect in communities that the disposal of excreta becomes a matter Hterally of Hfe and death, and before it can be settled the utmost skill and energy of a people may be taxed. The question of the proper mode of disposal of sewage has been some- what peii^lexed by not keeping apart two separate considerations. The object of the jDhysician is to remove as rapidly as possible all excreta from dwellings, so that neither air, water, nor soil shall be made imjiure. The agiiculturist wishes to obtain from the sewage its fertilizing powers. It is not easy to satisfy both parties, but it will probably be conceded that Bafety is the first thing to be sought, and that profit must come afterward. SECTION L AMOUNT AND PRODUCTS OF THE SOLID AND FLUID EXCRETA. Amount of the Solid and Fluid Excreta. The amount of the bowel and kidney excreta vary in different persons and with different modes of life. On an average, in Europe, the daily sohd excreta are about 4 ovmces by weight, and the daily fluid excreta 50 ounces by measure for each male adult. Women and children pass rather less. Vegetable pass more sohd excreta than animal feeders, but this is chiefly owing to a large proportion of water. ' Taking all ages and both sexes into ' Mr. Fawcus's experiments on Bengalee prisoners give an average bowel excretion of 12 ounces, and in Bombaj Dr. Hewlett found the alvine discharges to be quite as large. REMOVAL OF EXCRETA. 17 consideration, we may estimate the daily amovmt per bead of population in Europe at 2|- ounces of fsecal, and 40 ounces of urinary discharge, A popu- lation of 1,000 persons would thus pass daily 156 lb of soHds and 260 gallons of urine, or in a year 25 tons of faeces, and 91,250 gallons (14,646 cubic feet) of urine. Letbeby gives the mean amount per bead as 2.784 ounces of faeces and 31.851 ounces of urine. In a mixed population of 1,000 per- sons of different sexes and ages, Letbeby has calculated that the daily dis- cbarge of the whole town will be 2,266 tb avoir, of urine and 177.5 ft) of faeces. Frankland estimates the mean daily amount per head as 3 ounces of faeces and nearly 40 ounces by measure of urine. In adult males the quantity of nitrogen daily discharged by the bowels and kidneys amounts to from 250 to 306 grains, representing 304 and 372 grains of ammonia. Taking the whole population, however, the amount must be considerably less than this. Dr. Parkes calculated it as 153 grains of nitrogen, and Letbeby gave it as 155.8 grains, or from 186 to 189 grains of ammonia, i.e., the mean excretion of aU. the population is very nearly half the excretion of the adult male. Decomposition of Sewage Matter. Fresh healthy faecal matter fi'om persons on mixed diet, unmixed with urine, has an acid reaction, and this it retains for a considerable time ; it then becomes alkaline from ammonia. If free from urine, it usually decom- poses slowly, and in hot weather often dries on the surface, and subse- quently changes but little for some time. The urine, when unmixed with faecal matter, also retains its natural acidity for a variable number of days, sometimes three or four ; sometimes eight or ten, or even longer, and then becomes alkaline from ureal decomposition. When the faeces and urine are mixed, the formation of ammonium carbonate fi'om ureal decomposi- tion is much more rapid ; the solid excreta seem to have the same sort of action as the bladder mucus, and the mixed excreta become alkaline in twenty-four hours, while the separate excreta are stiU acid. And in its turn the presence of the urine seems to aid the decomposition of the soUd matter, or this may be perhaps from the effect of the fluid, as pure water seems to act almost as rapidly as luine in this respect. Pappenheim' states that the absorption of oxygen by the faeces is greatly increased when urine is added. When the solid excreta and mine are left for two or three weeks, the mixture becomes usually extremely viscid, and this occurs, though to a less extent, when an equal quantity of pure water takes the place of urine. The viscidity is prevented by carboUc acid. When the soHd excreta (unmixed with urine) begin to decompose, they give out very fetid substances, which are no doubt organic ; hydrogen sulphide is seldom detected, at any rate by the common plan of suspend- ing paper soaked in lead solution above the decomposing mass. When heated, a large quantity of gas is disengaged, which is inflammable, and consists in great measure of carburetted hydrogen. When (instead of being dry) urine is present, ammonia and fetid organic matters are disengaged in large quantity. When water is also present, and if the temperatm-e of the air is not too low, not only organic matters but gases are given out, consisting of light carburetted hydrogen, nitrogen, and carbon dioxide. Hydrogen sulphide can be also disengaged by beat, and is almost always 1 Handb. der. San. Pol., 2d edit., Band L, p. 72. Vol. II.— 3 18 PRACTICAL HYGIENE. found in the liquid, usually in combination with ammonia, from which it is sometimes liberated and then passes into the air. , SECTION n. METHODS OF REMOVAL OF EXCRETA. While all will agree in the necessity of the immediate removal of excreta from dwellings, the best modes of doing so are by no means settled. The fact is that several methods of removing sewage are applicable in different circumstances, and their relative amounts of utility depend entii'ely on the condition of the particular place. The different plans may be conveniently divided into' — 1. The water method. 2. The dry methods. Before noticing these plans, it will be convenient to make a few general observations on sewers. Sewers. Sewers are conduits employed to remove waste water and waste pro- ducts suspended in water from houses, or to carry away rain. Among the waste products may be the solid and liquid excreta of men and animals, or the refuse of trade and factory operations. Or sewers may be used merely for the conveyance of dirty house water, without the admixture of excreta or trade refuse. It is quite impossible that any town or even any single large house can be projDerly freed of its waste house water without sewers, and in a more or less perfect condition they are to be found not only in all ruodern, but in most ancient cities. Originally, no doubt, they were mere surface channels, as they are still in many towns ; but for the sake of ajopearance and inoffensiveness, the custom must have soon arisen of placing them underground, nor in modern towns could they now be an-anged other- wise. In some large towns there are even hundreds of miles of sewers, constructed often with great skill and science, and they serve in some in- stances as the channels not only for rain, but for natui'al streams which have been enclosed. The sewers form thus in the subsoil of towns a vast network of tubes, connecting every house, and converging to a common outlet where their contents may be discharged. In some towns the sewers carry away none of the soHd excreta, though probably urine enters in all cases. In most towns, however, solid excreta, in greater or less quantity enter, owing especially to the prevalent use of water-closets, or to the drainage of middens and manure heaps. Whether the solid excreta pass in or not, the liquid in the sewers must always contain either suspended or dissolved ainimal and vegetable matters derived from the refuse of houses. It is generally warmer than the water ' Dr. Corfield's work (A Digest of Facts relating to the Treatment and Utilization of Sewage, by W. H. Corfield, 2d edit., 1871) will be found to give a good summary of this subject. See also Report of a Committee appointed by the President of the Local Government Board to inquire into the several modes of treating Town Sewage, Lon- don, Eyre & Spottiswoode, 1876; see also "Die Menschliche Abfallstoffe," von Dr. Ferd. Fischer, Supplement zur Deutschen Viertelj. f. Offt. Gesundh., 1882. EEMOVAL OF EXCRETA. 19 of streams, and is of no constant composition ; sometimes it is very turbid, and higlily impui-e ; in other cases it is hardly more impure than the water of surface wells. The suspended matters are, however, generally in larger proportion than the dissolved. In some cases the sewer water is in greater amount than the water supplied to the town and the rainfall together. This arises from the sub- soil water finding its way into the sewers. One ton of London or Rugby sewage contains only from 2 Bb to 3 ft) of solid matter (Lawes).' The average composition of sewer water in towns with water-closets is, organic matter, 27.72; nitrogen, 6.21; phosphoric acid, 1.57; potash, 2.03 grains per gallon.'^ The Elvers Pollution Commissioners give 7.28 grains of organic ni- trogen per 100,000 parts, or 5.41 grains per gallon ; the mean amount of ammonia is 6.703 per 100,000, or 4.695 gi-ains per gallon. Under the microscope, sewer water contains various dead decaying matters^ and in addition multitudes of Bacteria and amoebiform bodies, as well as some ciUated infusoria, especially Paramecia, Fungi (spores and mycelium) are seen, but there are few Diatoms or Desmids, and not many of the higher animals, such as Rotifera. A controversy is stUl going on, whether the solid excreta ought to be admitted into the sewers. The point is virtually practically decided in many towns in this country by the general use of water-closets, which cannot now in these towns be superseded by any plan yet proposed. It is, however, quite an open question, whether, if all the arrangements could be commenced de novo, the admission of the solid excreta would be proper. The arguments for and against this view will presently be stated. Whether the solid excreta are allowed to pass in or not, it is clear that the dirty water of the sewers must in some way be disposed of. It is in every case more or less impure, containing animal and vegetable sub- stances in a state of commencing decay, which passes readily into putre- faction. The readiest mode of getting rid of it is to pass it into streams, where it is at once subjected to the influence of a large body of water, and where the solid matters become either slowly oxidized, or form food for fishes or water plants, or subside. Although from an early period streams were thus contaminated and their water originally pure was thus rendered unfit for use, it is only lately that a strong opposition has arisen to the discharge into streams. This is owing partly to the greater pollution and nuisance caused by the more common use of water-closets and the largely increasing trade of the country, which causes more refuse to be sent in, and partly to the evidence which has been lately brought forward "of the diseases which are caused by drinking water made impure in this waj'. To prevent the nuisance and danger caused by the pollution of streams, many actions at law have been brought, and in some cases special Acts of Parhament have forbidden the discharge of sewer water into certain rivers until after efficient purification. The Elvers Pollution Act of 1876 now deals with the question, its provisions having come into operation on August 15, 1877. ' For the composition of sewer water see Way, Second Report of Common Sewage of Towns, 1861, p. 69 et seq.; Letheby, The Sewage Question, 1872, p. 135 ; Report on Town Sewage, 1876 ; Rivers Pollution Commissioners' Report. ^ Letheby, op. cit., p. 138. 20 PRACTICAL HYGIENE. Up to a certain point, there "would probably be a general agreement as to the priucijile on -which this difficult question should be dealt ■with. Animal substances in a state of decay can be best jjrevented from con- taminating the air, the soil, or the water of streams, by imitating the operations of nature. In the endless cycle of physical change, decaying animal matters are the natural food of 2:>lants, and plants again form the food of animals. It so hapjDens that, -with the exception of some mineral trades, the ■waste products of "n-hich are hvu-tful to agriculture, many of the substances contained in the se^ner ■water of our towns are adapted for the food of plants, and we seem on sure ground when we decide that it must be cor- rect to submit these matters to the action of plant life, and thus to con- vert them from dangerous impmities into wholesome food. The difficulty is, however, with the application of the principle, and at the present moment there is the utmost diversity of opinion on this point. It seems, however, that we may di-vide the opinions into two classes. According to one opinion, the proper mode is to bring the waste water of towns, when it contains fertilizing matters, at once to the ground, and after the aiTest of substances which may block the pipes, to pour it over the land in such a way as may be best adapted to free it from its impuri- ties, and to bring it most raj)idly and efficiently under the influence of growing plants. The other opinion objects to this course on two grounds : first, that the substances are not brought to the ground in the most convenient foi-m for agriculture, and also that the plan entails e^vils of its own, arising from the immense quantity of water brought upon the land and from the diffi- culty of efficient management. The advocates of this second view would, therefore, use some plan of separating the impurities of the water, and would then apply them in a solid form to the land, or use them for some other purpose, as in General Scott's plan of adding the materials for cement and then making this substance. The puiified water would then be filtered through land, or passed into streams, without fui'ther treat- ment. In the case of the sewage water containing materials not adapted for agriculture, both parties would deal with it in the same way, ■viz., purify it by chemical agencies or filtration, and then allow the water to flow off into streams, while the solid products would be disposed of in the most con- venient way. These general -views apply to any sewer water, whether it contains solid excreta or not, although if these exci'eta can be perfectly excluded the sewer water is less offensive. It has hitherto been often pom-ed into streams -^-ithout pre^sious purification, though now this practice is pro- hibited by law, with certain reservations. The sewers of a town are for the most pai't used also to cairy off the rainfaU, and, indeed, before the introduction of water-closets, they were used only for this pm-pose, and for taking away the slop and sink water of houses. In countries with heavj' rainfall, and in this country in certain cases, the rainfall channels are distinct from the sewers, and the outfaUs may be in an entu-ely different direction. This is sometimes called the " separate system." Removal of Excreta by Water. This is -the cleanest, the readiest, the quickest, and in many cases the most inexpensive method. The water supplied for domestic pui-poses. EEMOVAL OF EXCEETA. 21 whicli lias possibly been raised to some height by steam or horse power, gives at once a motive force at the cheapest rate ; while, as channels must necessarily be made for the conveyance away of the waste and dii'ty water, which has been used for domestic purposes, they can be used with a little alteration for excreta also. It would be a waste of economy to allow this water to pass off mthout applying the force which has been accumulated in it for another purpose. But if this is obvious, it is no less so that certain conditions of success must be present, without which this plan, so good in principle, may utterly fail. These conditions are, that there shall be a good supply of water, good sewers, ventilation, a proper outfall, and means of disposing of the sewer water. If these conditions cannot be united, we ought not to 'dis- guise the fact that sewers, improperly arranged, may give rise to no incon- siderable dangers. They are underground tubes, connecting houses and allowing possibly, not merely accumulation of excreta, but a ready trans- ference of gases and organic molecules from house to house, and occasion- ally also causing, by bui'sting, contamination of the ground, and poisoning of the water supply. And all these dangers are the greater from being concealed. It is probably con-ect, as has been pointed out, that in deep- laid sewers the pressm-e inward of the water of the surrounding soil is so great as frequently to cause an inflow into the sewer, and so prevent the exit of the contents ; but in other cases, the damage to the sewer may be too great to be neutralized in this way, and in the instance of superficially laid and choked-up pipes, the pressure outward of the contents must be considerable. The dangers of sewers have now been greatly reduced, by having good material, better construction, good ventilation, sufficient water supply, and means of disposal of the sewage water. Amount of Water for Sewers intended for Excreta. Engineers are by no means agreed on the necessary amount. We Lave ah-eady named 25 gallons per head per diem, on the authority of Ml". Bi-unel, as the amount required to keep common sewers clear, and even with this amount there should be some additional quantity for flushing. But in some cases, a good fall and well-laid sewers may require less, and in other cases, bad gradients or curves or workmanship may require more. It is a question whether rain water should be allowed to pass into sewei's ; it washes the sewers thoroughly sometimes, but it also carries debris and gravel from the roads, which may clog ; while in other cases storm waters may burst the sewers, or force back the sewage.* Construction of Sewers. Sewers are differently constructed according to the purposes they are to sei-ve, i.e., whether simply to carry off house and trade water, or the solid excreta in addition, or one or both, with the rainfall. In following out the subject, it will be convenient to trace the sewers from the houses to the outfall. ' Storm overflows require to be provided ; for a description of them see Bailey- Denton, op. cit., sections Isii. and Ixxxv. 22 PRACTICAL HYGIENE. House Pipes and Drains. It will be convenient to call the conduits inside the house, which run from sinks and closets, "house pipes," and to give the term " drain pipes " to the conduits which receive the house pipes, and carry the house water into tanks or main sewers. The house pipes may be divided into sink and water-closet or soil pipes ; they are made of metal (lead, iron, or zinc, or two of these) or of earthenware. The drain pipes are usually made of well- burnt, hard, smooth, glazed earthenware.' All bricks, jDorous earthen- ware, or substances of the kind, should be considered inadmissible for drain pipes. Iron pipes are not much used in this country, but are common and in some places compulsory in America, when pipes have to be carried under houses. When made of heavy cast-iron, jointed and well caulked with lead or Spence's metal, they are the best in many circumstances. Inside they may be enamelled, or coated with Dr. Angus Smith's compo- sition, or treated by Barff's process. The pipes and drains vary in size from 4 to 16 inches diameter,'^ but the usual size of stoneware pij^es is 4 to 9 inches ; they are round or oval in shape.' Connection of House Fij^es with the Drains. — It is customary to com- mence the drams at the basement of the house, and the sink and closet pipes pass down inside the house and join on, a water-trap being placed at the junction.* As the aspiratory power of the warm house is then con- stantly tending to draw air through the water-trap, and as the trap is liable to get out of order, it is most desii-able to alter this plan. The drains should end outside the house, and as far as possible every house pipe should pass outside and not inside or between walls to meet the drain. The object of this is that any imperfection in the pipe should not allow the pipe air to pass into the houses. At the junction of the house pipe and drain, there should not only be a good water-trap, but also complete ven- tilation and connection with the outside air at the point of junction. The ' Mr. Baldwin Latham cautions us to see that the socket of the drain pipe is made with and is a component part of the pipe, and not merely joined on. ^ Pipes are made up to 36 inclaes, usually roundup to 16 or 18 inches, and oval ahove that. Engineers are now desirous of restricting the term " drain" to a pipe that merely draws off moisture from land, using the term " sewer " for a pipe carrying sewage or liquid refuse of any kind. This distinction, however, has not been made in the Public Health Act of 1875, in which " drain" is used for the pipe that receives the "house pipes," and " sewer " for the main pipe of a system. (See Bailey Denton's Sanitary Engineering, p. 16.) 2 See Mr. William Lassie's Healthy Houses (2d edition) for much information on this and kindred subjects. Some of the drawings given here have been copied from Mr. Eassie's work, by his permission ; reference may also be made to Sanitary Arrangements for Dwellings, by the same author. ■* Builders are always anxious to conceal tubes, and thus carry them inside the walls, or in the case of hollow walls, between the two. The consequence is that any escape of air must be into the house. The leakage of a closet pipe carried down in a hollow wall often constantly contaminates the air of the house It would be infinitely better to run the pipes at once through the wall to the outside. Few persons have any idea of the carelessness of plumbers' work — of the bad junctions, and of the rapidity with which pipes get out of order and decay. When a leaden pipe carrying water is led into a water-closet discharge pipe, it is frequently simply puttied in, and very soon the dried putty breaks away, and there is a complete leakage of gas into the house. Even if well-joined, the lead pipe will, it is said, contract and expand, and thus openings are at last formed. Dr. Fergus, of Glasgow, and Dr. N. Carmichael, have directed particu- lar attention to this, in the case of lead closet pipes, which become easily perforated, and which have only a limited duration of wear. REMOVAL OF EXCRETA. 23 rule, in fact, sliould be, that the xmion of any house pipe whatever with the outside drain should be broken both by water and by ventilation. In addition, it should be a strict rule, that no drain pipe of any kind should pass under a house ; if there must be a pipe passing from front to back, or the reverse, it is much better to take it above the basement floor than underneath, and to have it exposed throughout its course. In such a case it ought to be of cast-iron, as already mentioned. It is hardly possible to insist too much on the importance of this rule of disconnection between house pipes and outside drains. Late events have shown what a risk the richer classes in this country now i-un, who not only bring the sewers into the houses, but multiply water-closets, and often put them close to bed- rooms. The simple plan of disconnection, if properly done, would insure Fig. 76. — Jennings' Access-pipe. Fig. 77.— Stiffs Access-pipe and Junction. Fig. 78. — Doulton & Watt's Access-pipe. them against the otherwise certain danger of sewer air entering the house. Houses which have for years been a nuisance from persistent smells have been purified and become healthy by this means. Cleansing of Pipes and Drains. — Pipes are cleaned by flexible bamboo or jointed rods with screws and rollers to loosen sediment. The safest plan of cleaning drains is from man-holes, the drains being laid in straight fines from man-hole to man-hole. By this means obstructions are easily detected and removed. The use of movable caps runs the risk of leakage, it being difficult to make the drain water-tight again after removing the cap, but with care such caps ( see Figs. 75 to 77) are useful with small pipes, where man-holes can- not be employed. Drain pipes should also be cleared out by regular flushing, carried out not less often than once a month. This is best done by means of an automatic apparatus such as Field's flush tank (Fig. 79). By regulating the flow of water, it may be made to empty itself as often as necessary. ■ Laying of Drains. — They should be laid very carefully on concrete in all soils. Some- times, in very loose soils, even piling for the Fig. 79.-Fieid'R Pi^Bh Tank. j^^^j^ ^f ^ f ^q^. ^^^^ y^^ ^^^^ bcsides the Con- crete. When pipes are not laid on a good foundation, leakage is sure to occursooner or later, and the final expense is far more than the first outlay would have been. The greatest care must be taken in laying and joining the pipes, and in testing them afterward to make sure they are water-tight. In a wet soil, a good plan is to have a firm basis, or invert block, which 24 PRACTICAL HYGIENE. is itself perforated to carry off subsoil water, and to put the drain over this, as in the plan of Messi's. Brooks & Son, of Huddersfield (see Fig. 92). The "junction" of pipes is accomplished by special pipes, known by the names of single and double squares, c^^rved or oblique junctions, ac- cording to the angle at which one pipe runs into Q PI IP the other. The square junctions are undesir- ff\ \ S T il H /^ able, as blockage will always occvir, and the (fij^ J U L SI L/^ obHque junctions should be insisted upon. When Q ^K one pipe opens into another, a taper pipe is often Av-^— J (Jl!^-^~~1 ^sed ; the calibre being contracted before it en- ters the receiving pipe. All jointing must be in Fig. 8 .—Junctions. good ccmcut, uulcss Special patent joints (such as Stanford's) are used. Clay jointing is wholly inadmissible. Fall of Drain Pipes. — 1 in 30 for 4-inch drains, and one in 40 for 6- inch ; or roughly, for small drains 1 inch per yard. House Traps.— As the traps are usually the only safeguard against the warm house drawing sewer air into it, the utmost attention is necessary to insure their efficiency. There is almost an infinite diversity, but they can be conveniently divided into the siphon, the midfeather, the Jiap)-tra]j, and the ball-trap. The siphon is a deeply curved tube, the whole of the curve being always fuU of water. It is a useful trap, and efficient if the curve is deep enough, so that there is a certain depth of water (not less than f inch) standing above the highest level of the water in the curve, and if the water is never sucked out of it, and if the pipe is not too small, so that the water is earned away, when it runs full, by the siphon action of the pipe beyond. If two siphons succeed each other in the same pipe, without an air open- ing between, the one wiU suck the other empty. The midfeather is in principle a siphon ; it is merely a round or square box, with the enti-y at one side at the top, and the discharge pipe at a cor- responding height on the opposite side, and between them a partition reaching below the lower margin of both pipes. Water, of coiu'se, stands in the box or receptacle to the height of the discharge, and therefore the partition is always to some extent under water. Tlie extent should not be less than | of an inch. Heavy substances may subside and coUect in the box, from which they can be removed from time to time ; but as ordinarily made, it is not a good kind of trap, as it favors the collection of deposit, and is not self-cleaning. The common ball-trap, with its modifications, is a variety of the midfeather- trap, but it is so inefficient that it ought to be given up. The best kind of sink trap is the simple siphon, with a screw cap by which to clean it (Fig. 81). The flap) is used only for some drains, and is merely a hinged valve which allows water to pass in one direction, but which is so hung as to close afterward by its own weight. It is intended to prevent the reflux of water into the secondary drains, and is svipposed to prevent the passage of sewer gas. But it is probably a very imperfect block. The hall-trap is used in some special cases only ; a ball is lifted up as the water rises, until it impinges on and closes an orifice, is not a very desirable kind. However varioiis may be the form and details of the water-trap, they can be referred to one or other of these patterns. EEMOVAL OF EXCRETA. 25 Efficiency of Traps. — "Water should stand in a trap at least f of an inch above openings, and it should pass thi'ough sufficiently often and with sufficient force to clear it. An essential condition of the efficiency of all traps is that they should be self-cleansing. Many traps are so con- structed that no amount of velocity of water can clear them. Such traps are the common mason's or dip-trap (Fig. 82), and the notori- FlG. 82. — Common Mason's o Dip-trap. Bad form of Ti'ap. Pig. 83.— D Trap. Bad form of Trap. ^ui'/;w)kA'-swww/'^fc.svs\\> ous D trap (Fig. 83), both of which are simply cess-pools, and could never be cleaned without being opened up. Such traps ought to be unhesitatingly condemned. Traps are often ineffective, — 1st, From bad laying, which is a very common fault, 2d, From the water getting thoroughly impregnated with sewer effluvia, so that there is escape of effluvia from the water on the house side. 3d, From the water passing too seldom along the pipCj'so that the trap is either dry or clogged. 4th, From the pipe being too small (2 or 3 inches only), and "running full," which will sometimes suck the water out of the trap ; it usually occurs in this way, as frequently seen in sink traps : the pipe beyond the trap has perhaps a very great and sudden fall, and when it is full of water it acts Hke a siphon, and sucks all the water out of the trap ; to avoid this, the pipe should be large enough to pre- vent its running full, or the trap should be of larger calibre than the rest of the pipe. This, however, will not always prevent it, as even 6-inch pipes have sometimes sucked a siphon vmmwi'm'miM dry. The question has lately been very care- fully investigated in America, by Messrs. Phil- brick and Bowditch,' whose report has shown the dang'er of unsiphoning which small pipes are exposed to. The remedy appears to be to introduce an air- vent at the crown of the trap (see Fig. 84), and not to have too small a pipe, especially when several pipes unite in one general waste. The experiments also showed how un- siphoning might take place from the pressure of descending water from upper floors, so that air might be forcibly driven 1 The Sanitary Engineer, vol. vi., p. 264, 1882 (New York). The Siphonage and Ventilation of Traps, Report to the National Board of Health, bv E. W. Bowditch and E. S. Philbrick, C.E. ^A Fig. 84. — Siphon Closet Basins with ventilating pipes. A, Soil pipe pass- ing up above the eaves, witli open top. B, Subsidiary Ventilating Pipe (also passing up above eaves, with open top) to prevent sucking of the si~phon. 26 PRACTICAL HYGIENE. into the house when upper closets or sinks were used. 5th, Traps may perhaps be inefficient from the pressure of the sewer air, combined with the aspirating force of the house displacing the water, and allowing the air uninteri'upted communication between the sewer and the house. The extent of the last danger cannot be precisely stated. From a long series of obsen'ations on the pressure of the air in the London sewers, Dr. Bur- don-Sanderson ascertained that in the main sewers, at any rate, the pressure of the sewer air, though greater than that of the atmosjjhere, could never displace the water in a good trap. In a long house drain which got clogged, and in which much development of gaseous efflvivia occurred, there might possibly be for a time a much greater pressure, but whether it would be enough to foi'ce the water back, with or without the house suction, has not been yet experimentally determined. Dr. NeiU Cai-michael has shown that water siphon traps act efficiently so long as they Fig. 85. — Pipes open- ing above Grating and Trap. Fio. 86. — Disconnecting and Ventilat- ing Drain Trap, No. 2, Buclian's Patent. Fig. 87. — Sim- ple GuUey Trap. are not emptied by any siphon action beyond. But the reasons already given show that we ought not to place dependence solely on traps, ' though they are useful adjuncts. In arranging the house pipes, the sink and waste-water pipes must not be carried into the closet soil pipes, but must empty in the open air over a grating.^ See Fig. 85. In the case of soil or water-closet pipes there must be also a complete air-disconnection be- tween the jDipe and drain by means of one of the contrivances now used by engineers. At the point where this disconnection is made, there ought to be some easy means of getting at it for inspection. A good simple form is Buchan's trap (Fig. 86). A good form of man- hole is Mr. Rogers Field's (see Figs. 88 to 90).' Professor Reynolds* has suggested an arrangement which seems fairly good and simple. A simple trap is made by inserting a pipe in the centre of a siphon, and carrying this pipe to the surface, or higher if considered desirable. It is, however, apt to be clogged with grease, faeces, and other light matter ris- ing into the pipe. There are various similar aiTangements. The " Som- erset Patent Trap," designed by Mr. Honeyman, and much used at Glasgow, ' "Honestly speaking, traps are dangerous articles to deal witli ; tliey should be treated merely as auxiliaries to a good drainage system." — Eassie. '■* For the sake of appearance in some cases, it may be necessary to carry the pipe immediately binder the grating, but care must be taken that nothing occurs to obstruct the free communication with the open air through the grating. ' From Mr. Field's By-Laws for Uppingham, with later improvements. I am in- debted to Mr. Field for several valuable suggestions. — [F. de C] '' Sewer Gas, by Osborne Reynolds, M.A., Professor of Engineering at Owens College, Manchester, 2d edition, 1872. EEMOVAL OF EXCRETA. 27 Disconnecting- Man-hole. Perforated Iron Door, From. 'House: Cleaning Branch To Sevxr. Fig. 88. — Longitudinal Section. Fig. 89.— Plan. Fig. 90. — Cross Section. on one is a midfeather-trap with an air-shaft on each side the partition side the shaft ventilates the pipe leading to the sewer, on the other allows fresh air to pass into the house pipe. This second shaft also allows the trap to be cleaned. Eain-water pipes are sometimes used to ventilate drains, but independent of their small size, w*hich often leads to blockage, they are oft«n full of rain, and cannot act at the time when ventilation is most required. They are also apt to dehver sewer gas into garret win- dows. The plan is objectionable, and ought to be abandoned. A good form of disconnecting trap for sink and slop waters is Dean's, which has a movable bucket for removing deposit (Fig. 91). In yards, gully traps of different kinds are used, the action of which will be at once understood ing (Fig. 87). Examination of House Pipes and Traps. Pipes and traps are generally so covered in that they cannot be in- spected ; but this is a bad arrangement. If possible, all cover and skii-ting boards concealing them should be removed, and the pipe and trap under- ground laid bare, and every joint and bend looked to. But supposing this cannot be done, and that we must examine as well as we can in the dark, so to speak, the following is the best course : — Let water run down the pipe, and see if there is any smell ; if so, the pipe is full of foul aii- and Fig. 91.— Deans GuUy Trap. A, Han- dle of movable bucket. from the draw- 28 PRACTICAL HYGIENE. wants ventilation, or the trap is bad. If a liglited candle, or a bit of smouldeiing brown paper, is held over the entrance of the pipe or the gi'ating over a ti-ap, a rellux of air may be found with or without water being poured down. It should be noticed, also, whether the water runs away at once, or if there is any check. Tliis is all that can be done inside the house ; but though the pipe cannot be distui'bed inside, it may be pos- sible to open the earth outside, and to get do^vn to and open a drain ; in that case, pour water mixed with hme down the house pipe ; if the whitened water is long in appearance, and then i-uns in a dribble merely, the drains want flushing ; if it is much colored and mixed with dirt, it shows the pipes and trap ai-e foul, or there is a sinking or depression in some part of the di'ain where the water is lodging. The pipe should then be flushed by pouiing down a pailful of lime and water till the Hme-water flows off nearly clear. The di-ain should also be blocked, and water poured into the house pipe to see if it be water-tight in eveiy part. Yard-traps ai'e often very foxil, and if the trap-water be stii'red, gas bubbles out, which is a sign of great foulness, or that the traps are seldom used. Main Sewers. The outside house di-ain ends in a channel which is common to several drains, and which is of larger size. These lai'ger sewei's ai'e made either of round glazed earthenwai-e pipes from 15 to 24 inches diameter, or of well-bui'nt impersious brick moulded in proper curved shape and set in Port- land cement, or stoneware bricks are partly used> The shape now almost universally given, except in the largest outfall pai't, is that of an egg with the ^Dr^nT^dTu^bsoU kJ^''^^ ^^^ ^^^ downward. Engineers take the greatest cai-e with these brick sewers ; they ai'e most solidly put together in all parts, and are bedded on a firm un^delding bed. Much discussion has taken place as to theu' size, but the question is so compH- cated by the admission of rain water, that it is difficult to lay down any fixed inile, at least as regards the main j^ipes. All other sewers, however, should be small, and M'ith such a fall as to be self- cleansing. Sewers should be laid in as straight lines as possible, with a regukr fall ; tributary sewers should not enter at right angles, but obhquely ; and if the sewer cui-ves, the radius of the cuiwe should not be less than 10 times the cross sectional diameter of the sewer. Sometimes there is an arrangement for subsoil di-ainage under a pipe drain, as in the plan proposed by ]\Ir. Brooks. The fall for street drains is usually from 1 in 244 to 1 in 784, according to the size of the drain. The flow through a sewer should in no case be less than 2 feet per second, and 3 is better. As in the house drain, the fall should be equable without sudden changes of level. ' ' In some cases a fall is almost impossible to obtain, as, for instance, at Soutbport, in Lancashire, where the ground is nearly a dead level. The fall there is about 1 in 5,000, and never exceeds 1 in 3,000. In such a case the drain would have to be cleaned either by locks or valves (flushing-gates) to retain a portion of the contents for a time, and then set them free suddenly in order to flush the next section, or by special arrange- ments, such as Field's flush-tank. KEMOVAL OF EXCEETA. 29 Access to Sewers. It is of importance that to all sewers capable of being entered by a man, there should be an easy mode of access. Man-holes opening above, or, what is better, at the side, should be provided at such frequent intervals, that the sewers can be entered easily and inspected at all points. The man-holes are sometimes provided with an iron shutter to prevent the sewer air passing into the street, or by the side of the man-hole there may be a ventilating chamber. ' ■ Calculation of Discharge from Sewers.^ Several formulae have been given, of which the following is the most simple : — V = 55 X (y D X 2F). V = velocity in feet per minute. D = hydraulic mean depth. F = fall in feet per mile. Then, if A = section area of current of fluid, VA = discharge in cubic feet per minute. To use this formula, the hydraulic mean depth when the sewage is flowing, and the amount of fall in feet per mile, must be first ascertained. The hydraulic mean depth is :^th the diameter in circular pipes ; in pipes other than circular, it is the section area of current of fluid divided by the wetted perimeter. The wetted perimeter is that part of the circumference * Mr. Baldwin Latham joins the sewers in man-holes, so that if one is blocked an- other may be used ; the outlet being at the lower level. ^ The following table, taken from Mr. Wicksteed, will be found useful: — Sewers. Diameter. Velocity in feet per minute. Gradient required. inches 240 1 in 9 10 15 220. 220. 220. 210. 180. 36 65 87 98 119 244 Velocity Diameter. in feet per minute. 18 inches 180 1 180. 180. 180. 180. 180. Gr.idient required. in 294 " 343 392 490 588 784 Mr. Latham (Lectures on Sanitary Engineering, delivered to the Royal Engineers at Chatham) gives a table, of which the following is an extract : — Diameter in inches. Rate of inclination for velocity per second. 2 feet. 3 feet. 4 feet 5 feet. 6 feet. 4 1.194 1.92 1.53 1.34 1.24 6 292 389 137 183 80 106 51 69 36 8 48 9 437 206 119 77 54 10 486 229 133 86 60 12 583 275 159 103 72 In this table the velocity in feet multiplied by the inclination equals the length of the sewer to which the calculation applies. For example, if the velocity is 6 feet per second in a pipe whose diameter is 4 inches, then 6 x 24 = 144 feet is the length of the sewer, 30 PRACTICAL HYGIENE. of the pipe wetted by the fluid. The fall in feet per mile is easily ob- tained, as the fall in 50 or 100 or 200 feet can be measui-ed, and the fall per mile calculated (5,280 feet = 1 mile). Movement of Air in the Sewers and Ventilation. It seems certain that no brick sewer can be made air-tight ; for on ac- count of the numerous openings into houses, or from leakage through brickwork, or exit through gratings, man-holes, and ventilatmg shafts, the au- of the tubes is in constant connection with the external air. There is generally, it is beheved, a cuiTent of air with the stream of water if it be rapid. The tension of air in main sewers is seldom very different fi-om that of the atmosphere, or if there be much difference equihbrium is quickly restored. In twenty-three obsei-vations on the air of a Liverpool sewer, it was found by Drs."^Parkes and Burdon-Sanderson,' that in fifteen "cases the tension was "less in the sewer than in the atmosphere outside (i.e., the outside air had a tendency to pass in), and in eight cases the reverse ; but on the average of the whole there was a sHght indraught into the sewer. In the London sewers, on the other hand, Sanderson noticed an excess of pressure in the sewers. If at any time there is a very rapid flow of water into a sewer, as in heavy rains, the au- in the sewer must be displaced ^^dth great force, and possibly may force weak traps ; but the pressui-e of aii' in the sewers is not appreciably affected by the rise of the tide in the case of seaboard towns. ^ The tide rises slowly, and the au- is displaced so equably and gTadually through the numerous apei-tures, that no movement can be detected. It is not possible, therefore, that it can force water-traps in good order, when there are sufficient ventilating apertures. On the contrai-y, the blowing off of steam, or the discharge of au- from an au--pump (as in some trade operations), gi-eatly heightens the pressure, and might drive air into houses. So also the wind blowing on the mouth of an open sewer must force the aii- back with great force. It is, therefore, important to protect the outfall mouth of the sewer against wind by means of a flap, and to prohibit steam or aii- being forced into sewers. i • i Proceedings of the Royal Society, Xo. 94, 1867, p. 52. - For a statement of these experiments iip to 1860, see Dr. Parkes' work On the Composition of the Urine, 1860, p. 85. Since this time the chief experiments have been by Voit, Pettenkofer, J. Ranke, E. Smith, Haughton, Fick and Wislicenus, Byas- son, Xoyes, Meissner, Pavy, Parkes, and others. At present the subject is being in- vestigated by a Committee of the British Association. 2 Henle's Zeitschrift at. Med., Band xxxii., p. 283. * Proceedings of the Royal Society, Xo. 89 (1867), and Xo. 94 (1867). Vol. n.— o 66 PRACTICAL HYGIENE. of common exercise, the nitrogenous elimination diminishes during the first day of exercise (Parkes). On tlie whole, if the facts have been stated correctly, the effect of exer- cise is certainly to influence the elimination of nitrogen by the kidneys, but within narrow 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 nitrogenous food. This is the case also with animals. The possible rea- son of this will appear presently. (Z) On the Tenvperature of the Body. — As already stated, the temperature of the body, as long as the skin acts, rises little. Dr. Clifford- AUbutt, ' from observations made on himself when climbing the Alps,^ found his temperature fairly uniform ; the most usual effect was a slight rise, com- pensated by an earher setting in of the evening fall. On two occasions he noticed two curious depressions, amounting to no less than 4.5° Fahi'. ; he believes these were due to want of food, and not to exercise per se. In experiments on soldiers when marching, Dr. Parkes found no difference in temperature ; or if there was a very slight rise, it was subsequently com- pensated for by an equal fall, so that the mean daily temperature remained the same.' A decided rise in temperature during marching would then show lessening of skin evaporation, and may possibly be an important in- dication of impending sunstroke. Changes in the 3Iuscles. — The discussion on this head involves so many obscure physiological points, that it would be out of place to pursue it here to any length. The chief changes during action appear to be these : — There is a considerable increase in temperature (Helmholtz) which, up to a certain point, is proportioned to the amount of work. It is also propor- tioned to the kind, being less when the muscle is allowed to shorten than if prevented from shortening (Heidenhain) ; the neutral or alkaline reaction of the ti'anquil muscle becomes acid from para-lactic acid and acid potas- sium phosphate ; the venous blood passing from the muscles becomes much darker in color, is much less rich in oxygen, and contains much more carbonic acid (Sczelkow) ; the extractive matters soluble in water lessen, those soluble in alcohol increase (Helmholtz, in frogs) ; the amount of water increases (in tetanus, J. Ranke), and the blood is consequently poorer in water; the amount of albumen in tetanus is less according to Kanke, but Kiihne has pointed out that the numbers do not justify this in- ference." Baron J. von Liebig stated that the creatin is increased (but this was an inference from old observations on the extractum carnis of hunted animals, and required confirmation). Sarokin has stated the same fact in respect of the frog. The electro-motor currents show a decided diminu- tion during contraction. ' Alpine Journal, May, 1871 . ' In the experiments made by Dr. Calberla (Arcliiv der Heilkunde, 1875, p. 376') and liis two guides, during their ascents of Monte Rosa and the Matterliorn, in August, 1874, no depressions were found as have been recorded by other observers. In none of the three persons did the temperature ever fall below 36.4' C. (=97.5° F.), or rise above 37.8^ C. ( = 100° F.). Dr. Thomas, of Leipsic, in ascents in Savoy and Dauphine (3,500 and 3, 750 metres), could also find no lowering of temperature. 3 Proceedings of the Royal Society, No. 127 and No. 136. ^Lehrb. der Phys. Chem., 1868, p. 323. EXEECISE. 67 That great molecular changes go on in the contracting muscles is cer- tain, but their exact nature is not clear ; according to Ludimar Hermann. ' there is a jelly-like separation and coagulation of the myosin, and then a resumption of its prior form, so that there is a continual splitting of the muscular structure into a myosin coagulura, carbon dioxide, and a free acid, and this constitutes the main molecular movement. But no direct evidence has been given of this. The increased heat, the great amount of carbon dioxide, and the dis- appearance of oxygen, combined with the respiratory phenomena akeady noted, aU seem to show that an active oxidation goes on, and it is very probable that this is the source of the muscular action. The oxidation may be conceived to take place in two ways — either during rest oxygen is absorbed and stored up in the muscles and gradually acts there, produc- ing a substance which, when the muscle contracts, sphts up into lactic acid, carbon dioxide, etc. ; or, on the other hand, during the contraction an increased absorption of oxygen goes on in the blood and acts upon the muscles, or on the substances in the blood circulating thi'ough the muscles.* The first view is strengthened by some of Pettenkofer and Voit's experi- ments, which show that during rest a certain amount of storage of oxygen goes on, which no doubt in part occurs in the muscles themselves. Indeed, it has been inferred that it is this stored up oxygen, and not that breathed in at the time, which is used in muscular action. The increased oxidation gives us a reason why the nitrogenous food must be increased during periods of great exertion. An increase in the supply of oxygen is a neces- sity for increased muscular action ; but Pettenkofer and Voit's observations have shown that the absoi-ption of oxygen is dependent on the amount and action of the nitrogenous structures of the body, so that, as a matter of course, if more oxygen is required for increased muscular work, more nitrogenous food is necessary. But apart from this, although experiments on the amount of nitrogenous elimination show no very great change on the whole, there is no doubt that, with constant regular exercise, a muscle enlarges, becomes thicker, heavier, contains more soUd matter, and in fact has gained in nitrogen. This process may be slow, but it is certain ; and the nitrogen must either be supplied by increased food, or be taken from other parts. ^ So that, although we do not know the exact changes going on in the muscles, it is certain that regular exercise produces in them an addition of nitrogenous tissue. Whether this addition occurs, as usually believed, in the period of rest succeeding action, when ia some unexplained way the destruction, which it is presumed has taken place, is not only repaii-ed, but is exceeded (a process difficult to understand), or whether the addition of nitrogen is actually made during the action of the muscle,* must be left undecided for 'the present. ^ Unters. iiber den StofEwechsel der Muskeln, von Dr. L. Hermann ; Weitere Unter- such. zur phys. der JVIuskeln, von Dr. L. Hermann, 1867. - Heaton (Quarterly Journal of Science, 1868) has given strong reasons for believing that the oxidation goes on in the blood. ^ The way in which a vigorously acting part will rob the body of nitrogen, and thus in some cases cause death, is seen in many cases of disease. A rapidly growing cancer of the liver, for example, takes so much nitrogen as well as fat that it actually starves the rest of the body, and both voluiitary muscles and heart waste. This is the case, though it is less marked, with growing tumors of other parts, and with great discharges. Powerful muscular action, if the food is not increased, evidently acts in something the same way ; the health is greatly affected, and the heart especially fails. * Proceedings of the Royal Society, No. 94, 1867. 68 PRACTICAL HYGIENE. The substances Tvhieli are thus oxidized in the muscle, or in the blood circulating through it, and from which the energy manifested, as heat or muscular movement, is believed to be derived, may prbably be of differ- ent kinds. Under ordinary cii'cumstances, the experiments and calcula- tions of Fick and Wislicenus, and <;thers, and the arguments of Traube, seem sufficient to show that the non-nitrogenous substances, and perhaps especially the fats, furnish the chief substances r.cted upon. But it is probable that the nitrogenous substances also furnish a contingent of energy. ' The exact mode in which the energy' thus 1 'berated oy oxidation is made to assume the form of mechanical motion is quite obsciu'e. The Exhaustion of Muscles. There seems Httle doubt that the exhaustion of muscles is chiefly o^ing to two causes — first, and principally, to the accumulation in them of the products of their own action (especially para-lactic acid) ; and, secondly, from the exhaustion of the supply of oxygen. Hence rest is necessary, in order that the blood may neutralize and can-y away the products of action, so that the muscle may recover its neutrality and its normal electrical cur- rents, and may again acquire oxygen in sufficient quantity for the next contraction. In the case of all muscles these intervals of action and of ex- haustion take place, in part even in the period which is called exercise, but the rest is not sufficient entii'ely to restore it. In the case of the heart, the rest between the contractions (about two-thfrds of the time), is sufficient to allow the muscle to recover itself perfectly. The body after exertion absorbs and retains water eagerly ; the water, though taken in large quantities, does not pass off' as rapidly as usual by the kidneys or the skin, and instead of causing an augmented metamor- phosis, as it does in a state of rest, it produces no effect whatever. So completely is it retained, that although the skin has ceased to perspire, the uiiue.does not increase in quantity for several hours. The quantity of W'ater taken is sometimes so gi-eat as not only to cover the loss of weight caused by the exercise, but even to increase the weight of the body. We can be certain, then, of the absolute necessity of water diu-ing and after exercise, and the old mle of the trainer, who lessened the quantity of water to the lowest point which could be borne, must be wrong. In fact, it is now being abandoned by the best trainers, who allow a liberal allowance of fluid. The error probabl}' arose in this way : if, during great exertion, water is denied, at the end of the time an enormous quantity is often di'urik, more, in fact, than is necessary, in order to still the ovei-jjow- ering thirst. The sweating which the trainer had so sedulously encour- aged is thus at once compensated, and, in his view, all has to be done over again. All this seems to be a misapprehension of the facts. The body must have water, and the proper plan is to let it j^ass in in small quantities ' Pavy shows, in his observations on Weston and Perkins, that the excess of nitro- gen eliminated dnring the walking period, over the period of rest, was equivalent to about 542 foot-tons per man per diem. The total average daily work done, he states at 1,264 foot-tons, but this is an under-estimate, as the velocity was apparently greater than that of average walking, the co-efficient of which (-/,r) he assumes as the proportion of resistance. N.B. — One grain of nitrogen eliminated, represents an amount of al- buminate expended, capable of yielding about 2.4 foot-tons of potential energy. Although some of the excess of nitrogen eliminated during exercise, as noted above, may have been due to disintegration of muscle, part of it was due (undoubtedly) to changes in other tissues, but a considerable amount is due to direct oxidation of albumi- nous food. EXEECISE. 69 and frequently ; not to deny it for hours, and tlien to allow it to pass in in a deluge. The plan of gi"\^ng it in small quantities frequently, does away with two dangers, viz., the rapid passage of a large quantity of cold water iuto the stomach and blood, and the taking more than is necessary/ In the French army, on the march, the men are directed not to drink ; but if very tliirsty, to hold water in the mouth, or to carry a buUet in the mouth. It is singular, in that nation of practical soldiers, to find such an order. Soldiers ought to be abundantly supphed with water, and taught to take small quantities, when they begin to feel tliirsty or fatigued. If they are hot, the cold water may be held in the mouth a minute or two before swallowing as a jDrecaution ; though there seems to be no evidence of any ill eifects from drinking a moderate quantity of cold water, even during the greatest heat of the body,^ General Effect of Exercise on the Body, as judged of by the Preceding Facts. — The main effect of exercise is to increase oxidation of carbon, and perhaps also of hydrogen ; it also eliminates water from the body, and this action continues, as seen from Pettenkofer and Volt's experiments, for some time ; after exercise, the body is therefore poorer in water, esjDecially the blood ; it increases the rapidity of circulation everywhere, as well as the pressure on the vessels, and therefore it causes in all organs a more rapid outflow of plasma and absoi-ption, — in other words, a quicker renewal. In this way also it removes the j)i'oducts of their action, which accumulate in organs ; and restores the power of action to the various parts of the body. It increases the outflow of warmth from the body by increasing perspira- tion. It therefore strengthens all parts. It must be combined with in- creased sujDply both of nitrogen and carbon (the latter possibly in the form of fatj, otherwise the absorption of oxygen, the molecular changes in the nitrogenous tissues, and the elimination of carbon, will be checked. There must be also an increased sujDply of salts, certainly of chloride of sodium ; probably of potassium phosphate and chloride. There must be proper intervals of rest, or the store of oxygen, and of the material in the muscles which is to be metamorphosed during contraction, cannot take place. The integrity and perfect freedom of action both of the lungs and heart are essential, otherwise neither absorption of oxygen nor ehmiuation of carbon can go on, nor can the necessary increased supply of blood be given to the acting muscles without injury. In aU these points, the inferences deducible from the physiological in- quiries seem to be quite in harmony with the teachings of experience. ^ It is but right to say fhat many travellers of great experience have expressed great fear of water under exertion. Some of them have most strongly urged that " water be avoided like poison," and have stated that a large quantity of butter is the best pre- ventive of thirst. At any rate, the butter may be excellent, but a little water is a necessity. ' Horses also used to be, and by some are now, deprived or stinted of water during exercise. But in India, the native horsemen give their horses drink as often as they can : and Dr. Nicholson says this is the case with the Cape horses ; even when the horses are sweating profusely, the men will ride them into a river, bathe their sides, and allow them to drink. 70 PRACTICAL HYGIENE. SECTION n. AMOUNT OF EXERCISE WHICH SHOULD BE TAKEN. It would be extremely important to determine, if possible, the exact amount of exercise yrhich a healthy adult, man or woman, should take. Every one knows that great errors are committed, chiefly on the side of defective exercise. It is not, however, easy to fix the amount even for an average man, much less to give any rule which shall apply to all the divers conditions of health and strength. But it is certain that muscular work is not only a necessity for health of body, but for mind also ; at least it has seemed that diminution in the size of the body from deficient muscular work seems to lead in two or three generations to degenerate mental for- mation. The external work which can be done by a man daily has been esti- mated at J-th of the work of the horse ; but if the woi'k of a horse is con- sidered to be equal to the 1-horse power of a steam engine (viz., 33,000 ft) raised 1 foot high per minute, or 8,839 tons raised 1 foot high in ten hours), this must be an over-estimate, as -^th of this would be 1,263 tons raised 1 foot in a day's work of ten hours. ' The hardest day's work of ' In some works on physiology a man's work of eight hours has been put as high as 316,800 kilogrammemetres, or 1,020 tons lifted a foot ; but this is far too much. In this country the amount of work done is generally estimated as so many lb or tons lifted one foot. In France it is expressed as so many kilogrammes lifted 1 metre. Kilogrammemetres are converted into foot-pounds by multiplying by 7.288. To bring at once into tons lifted a foot, multiply kilogrammemetres by .003229. The following table may be useful, as expressing the amount of work done. It is taken from Dr. Haughton's work (A New Theory of Muscular Action). The niambers are a little differ- ent from those given by Coulomb, as they were recalculated by Dr. Haughton in 1863. Laboring Force of Man. Kind of Work. Pile driving Pile driving Turning a winch Porters carrying goods and returning unladen Pedlers always loaded Porters carrying wood up a stair and return- ing unloaded Paviors at work Military prisoners at shot drill (3 hours), and oakum picking and drill Shot drill alone (3 hours) Amount of Work. Authority. 312 tons lifted 1 foot. Coulomb. 352 Lamande. 374 Coulomb. 325 " 303 <( 381 u 352 Haughton. 310 u 160.7 t( It may be interesting to give some examples of work done in India by natives, which have been noted by Dr. de Cliaumont: — A Leptcha hill-coolie will go from Punkabarree to Darjeeling (30 miles, and an as- cent of 5,500 feet), in three days, carrying 80 fti weight; the weight is carried on a frame supported on the loins and sacrum, and aided by a band passed round the fore- head. Work per diem, 500 tons lifted 1 foot. Eight palanquin bearers carried an officer weighing 180 tTi, and palanquin weighing 250 lb, 25 miles in Lower Bengal. Assuming each man weighed 150 lb, the work was 600 tons lifted a foot. EXERCISE. 71 twelve hours noted by Dr. Parkes was in the case of a workman in a cop- per rolling-mill. He stated that he occasionally raised a weight of 90 ft) to a height of 18 inches, 12,000 times a day. Supposing this to be cor- rect, he would raise 723 tons 1 foot high. But this much overpasses the usual amount. The same man's ordinary day's work, which he considered extremely hard, was raising a weight of 124 lb 16 inches, 5,000 or 6,000 times in a day. Adopting the larger number, this would make his work equivalent to 442.8 tons Ufted a foot ; and this was a hard day's work for a powerful man. Some of the puddlers in the iron country, and the glass- blowers, probably work harder than this ; but there are no calculations re- corded. From the statement of a pedler, his ordinary day's work was to carry 28 lb twenty miles daily. The weight is balanced over the shoulder — 14 ft) behind and 14 ft) in front. The work is equal to 419.5 tons lifted 1 foot. It would, therefore, seem certain that an amount of work equal to 500 tons lifted a foot is an extremely hard day's work, which perhaps few men could continue to do. 400 tons lifted a foot is a hard day's work, and 300 tons hfted a foot is an average day's work for a healthy, strong adult. The external work is thus 300 to 500 tons on an average ; the internal work of the heart, muscles of respiration, digestion, etc. , has been variously estimated ; the estimates for the heart alone vary from 122 to 277 tons Hfted a foot. The former is that given by Haughton, who estimates the respiratory movements as about 11 tons lifted a foot in twenty-four hours. Adopting a mean number of 260 tons for all the internal mechanical work, and the external work of a mechanic being 300 to 500 tons, this will amount to from ^-th to ^th of all the force obtainable from the food. The exertion which the infantry soldier is called upon to undergo is chiefly drill and carrying weights on a level, or over an uneven surface. The Eeverend Professor Haughton, M.D., who is so well known for his important contributions to physiology and medicine, has shown that walk- ing on a level surface at the rate of about 3 miles an hoiu- is equivalent to raising ^i^th part of the weight of the body through the distance walked ; an easy calculation changes this into the weight raised 1 foot. When as- cending a height, a man of course raises his whole weight through the height ascended. Using this formula,' and assuming a man to weigh 150 ft) with his clothes, we get the following table : — „. J „ -r, . Work done in Tons Kmd of Exercise. ^^^^^^ one foot. Walking 1 mile 17.67 2miles 35.34 10 " 176.7 20 " 353.4 ^' 1 mile and carrying 60 ft) ... , 24.75 2mUes " " 24-75 *' 10 " " " 247.5 " 20 " " " 495 It is thus seen that a march of 10 miles, with a weight of 60 ft) (which ' The formula is C w + W ) j< D ^-^ere W is the weight of the person, W the weight 20 X 2,240 carried; D the distance walked in feet ; 20 the co-efficient of traction; and 2,240 the number of pounds in a ton. The result is the number of tons raised 1 foot. To get the distance in feet, multiply 5,280 by the number of miles walked- 72 PRACTICAL HYGIENE. is nearly the weight a soldier carries when in marching order, but without blankets and rations), is a moderate day's work. A 20 miles' march, with 60 ft Aveight, is a very hard day's work. As a continued laboring effort Dr. Haughton believes that walking 20 miles a day, without a load (Sun- day being rest), is good work (353 tons lifted a foot) ; so that the load of 60 ft additional would make the work too hard for a continuance. ' It must, however, be remembered, that it is understood that the walk- ing is on level ground, and is done in the easiest manner to the person, and that the weights which are carried are properly disposed. The labor is greatly increased if the walk is irksome, and the weights ai'e not well adjusted. And this is the case with the soldier. In marching his attitude is stiff ; he observes a certain time and distance in each step ; he has none of those shorter and longer steps, and slower and more rapid motion, which assist the ordinary pedestrian. It may be questioned, indeed, whether the formula does not under-estimate the amount of work actually done by the soldier. The work becomes heavier, too, i.e., more exhausting, if it is done in a shorter time ; or, in other words, velocity is gained at the ex- pense of carrying power.' The velocity, in fact, i.e., the rate at which ' I calculated the work done by the sledge-parties in the Arctic Expedition of 1875-76, and found that the Northern party (Markham's), did a mean of 574 foot-tons per man per diem, with a maximum of 859 ; the Western party (Aldrich's) did a mean of 443, and a maximum of over OUO. Even this large amount was considered an under-esti- mate by the Commanders. (See Report of Committee on Outbreak of Scurvy (Blue Book), App. 24, p. 305).— [F. deC] -Dr. Haughton (Principles of Animal Mechanics, 2d ed., pp. 56 and 57) has deter- mined, from the calculation of the MM. Weber, the co-efficient of resistance for three velocities, as follows : — !.,„„„ , Co-efficient of MUes per hour. Resistance. 1.818 5-8^7^ 4.353 Ts^ro 10.577 T.Vi Interpolating between these numbers we can obtain the co-efficients at other veloci- ties. The following table shows the co-efficients, the distance in miles that would equal 300 foot-tons for a man of 150 tb, and the time in hours and minutes that would be required without rest: — Velocity in Miles Co-efficient of Distance for Men of Time required in per hour. Resistance. 160 ft), to equal Hours and Minutes. 300 foot-tons. H. M. 1 3^1,-8 30.3 30 12 2 5/7-4 21.2 10 36 3 ^5 9 16.3 5 24 4 r/.n 13.3 3 18 5 T4V0 11-3 3 36 6 -r/r-8 9-6 1 36 7 rif.^-^ 8.5 1 12 8 rVo "^-^ 5"^ 9 W.U 6.9 46 10 r^-s 6.3 . 38 The co-efficient -5V corresponds very nearly to 3.1 miles an hour, and this appears to be the rate at which the greatest amount of work can be done at the least expenditure of energy. (See Table XVIII. , p. 186, Lectures on State Medicine, by F. de Chaumont.) As regards velocity. Dr. Haughton states the " Law of Fatigue " as follows: — " When the same muscle (or group of muscles) is kept in constant action till fatigue sets in, the total work done, multiplied by the rate of work, is constant." The " Law of Refresh- ment" depends on the rate at which arterial blood is supplied to the muscles, and the "Co-efficient of Refreshment" is the work restored to the muscles in foot-pounds per ounce of muscle per second ; for voluntary muscle it is on an average (J.lBoO, and for the heart 0.3376, or exactly equal to the work of the heart, which never tires. — [F. de C.]. EXERCISE. 73 work is done, is an important element in the question, in consequence of the strain thi-own on the heart and lungs. The Oxford boat races — rowing at racing speed (=1 mile in 7 minutes) in an Oxford eight-oar, or 18.56 foot-tons in 7 minutes,' is not apparently very hard work, but it is Tery severe for the time, as its effect is gTeat on the cii'culatory system. Looking at all these results, and considering that the most healthy life is that of a man engaged in manual labor in the free au', and that the daily work will probably average from 250 to 350 tons lifted 1 foot, we can perhaps say, as an appi'oximation, that every healthy man ought, if possible, to take a daily amount of exei'cise in some way, which shall not be less than 150 tons lifted 1 foot. This amount is equivalent to a walk of about 9 miles ; but then, as there is much exertion taken in ordinary business of life, this amount may be in many cases reduced. It is not possible to lay down rules to meet all cases ; but probably every man with the above facts before him could fix the amount necessary for himself with tolerable accuracy. In the case of the soldier, if he were allowed to march easily, and if the weights were not oppressively arranged, he ought to do easily 12 miles daily for a long time, provided he was allowed a periodical rest. But he could not for many days,, without great fatigue, march 20 miles a day with a 60 ft) load, unless he were in good condition and AveU fed. If a greater amount still is demanded from him, he must have long subsequent rest. But all the long marches by our own or other armies have been made without weights, except arms and a portion of ammunition. Then great distances have been traversed by men in good training and condi- tion. SECTION m. trainhstg. The aim of the " Trainer " is to increase breathing power ; to make the muscular action moi'e vigorous and enduring, and to lessen the amount of fat. He arrives at his result by a very carefiil diet, containing little or no alcohol ; by regular and systematic exercise ; and by increasing the action of the eliminating organs, especially of the skin. What the "Trainer" thus accomplishes is in essence the follovmig : a concordant action is esta.blished between the heart and blood-vessels, so that the strong action of the heart during exercise is met by a more perfect dilatation of the vessels, and there is no blockage of the flow of blood ; in the lungs, the blood not only passes more freely, but the amount of oxygen is increased, and the gradual improvement in breathing power is well seen when horses are watched during training. This reciprocal action of heart and blood-vessels is the most important point in training ; the nutri- tion of nerves and muscular fibres imjDroves from the constant action, and the abundant supply of food ; the tissue changes are more active, and elim- ination, especially of carbon, increases. A higher condition of health ensues, and if not carried to excess, " training " is simply another word for healthy and vigorous Uving.^ ' Training, by A. Maclaren, p. 168. "^ Of course, over-training may be hurtful, but anything can be carried too far. Reference may be made to Dr. Morgan's highly interesting and well-worked out treatise on University Oars, to show that rowing is beneficial. Dr. Lee has published a useful little book, Exercise and Training, by R. Lee, M.D., with some good advice on training. CHAPTER XIII. CLOTHING. The objects of clothing are to protect against cold and against warmth ; aU other uses will be found to resolve themselves into one or other of these. The subject natui-allv diN-ides itself into two parts — 1st, The materials of clothing ; and 2d, The make of the garments, which will be considered in Book II., and only as far as the soldier is concerned. IVIateeials of Clothing, The following only will be described : — Cotton, linen, jute, wool, silk, leather, and india-rubber. Chemical Reaction. — These materials are all easily distinguished by microscopical characters, but certain chemical reactions may be useful. Wool and silk dissolve in boiling hquor potassae or hquor sodse of sp. gr. 1040 to 1050 ; cotton and hnen ai'e not attacked. Wool is little altered by lying in sulphuric acid, but cotton and linen change in half an hour into a gelatinous mass, which is colored blue by iodine. Silk is slowly dis- solved. Wool and silk take a yellow color in strong nitric acid ; cotton and hnen do not. So also wool and silk are tinged yellow by picric acid ; cotton and linen are not, or the color is slight, and can be washed off. Silk, again, is dissolved by hot concentrated chloride of zinc, which will not touch wool. In a mixed fabric of silk, wool, and cotton, first boil in strong chloride of zinc, and wash ; this gets rid of the silk ; tlien boil in hquor sodse, which dissolves the wool, and the cotton is left behind. An- other reagent is recommended by Schlesinger, viz., a solution of copper in ammonia ; this rapidly dissolves silk and cotton, and, after a longer time, linen ; wool is only somewhat swollen by it. By di-ying thoroughly first, and after each of the above steps, the weight of the respective materials can be obtained. ' ' If other fabrics than those mentioned in the text have to be examined, the best book to consult is Dr. Schlesinger's Mikrosoopisfhe Untersuch. der Gespinnst-Fasern (Zurich, 1873), where plates will be found of many of the fibres of commerce. The following are the chief reagents used by Schlesinger : -1st, Strong and weak sulphuric acid, to dissolve or swell out the fibres, and also, with iodine, to test for cellulose. 2d, Nitric acid, especially to show the markings. 3d, Chromic acid, as the best sol- vent for the intercellular substance, and for the swelling out in solution of the cellulose ; it is often used with sulphuric acid. 4th, Dilute tincture of iodine, which is added to cellulose, and then sulphuric acid is used. 5th, Solution of copper, made bj' dissolving metallic copper in ammonia ; this dissolves cell-membrane. (3th, Sulphate of aniline, which colors lignite yellow. 7th, Liquor potassae (dilute), to render the fabrics trans- parent. He advises the fabric to be put on a slip of gla.ss, and then a drop of water to be placed on it : then a needle should be drawn two or three times in the direction of the fibres, which will be easily detached. Then the fibre is laid on a glass and the re- agent is applied. CLOTHING. 70 Cotton — Microscopic Characters. — A diaphanous substance forming fibres a'bout ^ij-^th of an inch in diameter, flattened in shape, and ribbon-hke, with an interior canal which is often obhterated, or may contain some ex- tractive matters, borders a little thickened, the fibres twisted at intervals (about 600 times in an inch). It has been stated that the fresh cotton fibre is a cylindrical hair vnth thin walls, which coUapses and twists as it becomes dry. Iodine stains them brown ; iodine and sulphuric acid (in very smaU quantities) give a blue or violet-blue ; nitric acid does not de- stroy them, but unrolls the twists. As an Article of Dress. — The fibre of cotton is exceedingly hard, it wears well, does not shrink in washing, is very non-absorbent of water Fig. 93.— Cotton x 285. Fig. 94.— Linen x 285. (either into its substance, or between the fibres), and conducts heat rathef less rapidly than linen, but much more rapidly than wool.' The advantages of cotton are cheapness and durability ; its hard non- absorbent fibre places it far below wool as a warm water-absorbing cloth- ing. In the choice of cotton fabrics there is not much to be said ; smooth- ness, evenness of texture, and equality of spinning, are the chief points. In cotton shu-ting and calico, cotton is alone used ; in merino and other fabrics it is used with wool, in the proportion of 20 to 50 per cent, of wool, the threads being twisted together to form the yarn. Linen — 3Iicroscopic Characters. — The fibres are finer than those of ' Experiments on the conducting power of materials by Couller (Professor of Chem- istry at the Val de Grace), and by Dr. Hammond (late Surgeon-General, United States Army). 76 PRACTICAL HYGIENE. cotton, diaphanous, cylindrical, and presenting little swellings at tolerably regular intervals. The elementary fibres (of which the main filire is com- posed) can be often seen in these swellings, and also at the end of broken thi'eads which have been much used. The hemp fibre is something like Fig. 95.— Silk x 285. this, but much coarser, and at the knots it separates often into a number of smaller fibres. Silk is a httle hke linen, but finer, and with much fewer knots. As an Article of Clothing. — Linen conducts heat and absorbs water Fig. 96. — Jute — United and single elongated Cellular Tis-sues. Resinous (?) matter adhering more or le?s to all the fibres. slightly better than cotton. It is a little smoother than cotton. As an article of clothing it may be classed with it. In choosing linen regard is had to the evenness of the threads, and to the fineness and closeness of the CLOTHIJSTG. 77 texture. Tlie color should be white, and the surface glossy. Starch is often used to give glossiness. This is detected by iodine, and rerooved by the first washing. Jute. — Jute is now very largely used, and appears to enter into the adulteration of most fabrics. Jute is obtained from the Corchoriis capsu~ I iris, and comes to England from Eussia and India. The fibres are of considerable length, are hollow, thickened, and with naiTowings and con- strictions in the tubular portions ; sometimes an aii'-bubble may be in the fibre, as shown in the di'awing. The di-awing, by Dr. Maddos, shows the differences between the jute and cotton or linen. Wool — Microscopic Characterf^. — Round fibres, transparent or a httle hazy, colorless, except when artificially dyed. The fibre is made up of a number of httle cornets, which have become united. There are very evident sHghtly oblique cross mai'kings, which indicate the bases of the comets ; and at these points the fibre is very slightly larger. There are also fine longitudinal markings. There is a canal, but it is often oblitera- ted. "When old and worn, the fibre breaks up into fibrillse ; and, at the same time, the shght j)rominence at the cross markings disappear, and even the markings become indistinct. By these characters old wool can be recognized. Size of fibres varies, but an average is given by the figure. The finest wools have the smallest fibres. As an Article of Clothing. — "Wool is a bad conductor of heat and a great absorber of water. The water penetrates into the fibres themselves and distends them (hygroscopic water), and also hes between them (water of interposition). In these respects it is greatly superior to either cotton or linen, its power of hygroscopic absorption being at least double in proportion to its weight, and cjuadruple in projDoriion to its surface. This property of hygi'oscopically absorb- ing water is a most imporiant one. Duiing perspiration the evaporation from the sur- face of the body is necessary to reduce the heat which is generated by the exercise. When the exercise is finished, the evajDora- tion still goes on, and, as ah'eady noticed, to such an extent as to chill the frame. When dry woollen clothing is put on after exertion, the vapor from the sui-face of the body is condensed in the wool, and gives out again the large amount of heat which had be- come latent when the water was vaporizecL Therefore a woollen covering, fi'om this cause alone, at once feels wann when used during sweating. In the case of cotton and hnen the perspiration passes through them, and evaporates from the ex- ternal surface without condensation ; the loss of heat then continues. These facts make it plain why diy wooUen clothes are so useful after exertion.' Fig 97.— Wool x 285. ' Pettenkofer gives (Zt. fiir Biol., Band i., p. 185) some experiments showing the hy- groscopic power of wool as compared with linen. He shows that linen not only absorbs much less water, but parts with it much more qi^iekly ; thus, to cite one experiment, 78 PRACTICAL HYGIENE. In addition to this, the texture of wool is warmer, from its bad conduct- ing power, and it is less easily penetrated by cold winds. The disadvantage of wool is the way in which its soft fibre shrinks in washing, and after a time becomes smaller, harder, and probably less absorbent.' In the choice of woollen underclothing the touch is a great guide. There should be smoothness and great softness of texture ; to the eye the tex- ture should be close ; the hairs standing out from the surface of equal length, not long and straggling. The hea\T.er the substance is, in a given bulk, the better. In the case of blankets, the softness, thickness, and close- ness of the pile, the closeness of the textiu-e, and the weight of the blanket, are the best guides. In woollen cloth the rules are the same. When held against the light, the cloth should be of vmiform texture, without holes ; when folded and suddenly stretched, it should give a clear ringing note ; it should be veiy resistent when stretched with \'iolence ; the "tearing power" is the best way of judging if " shoddy " (old used and worked-up wool and cloth) has been mixed with fresh wool. A certain weight must be borne by every piece of cloth. At the Government Clothing Estabhshment at Pimlico, a machine is used which marks the exact weight necessaiy to tear across a piece of cloth. Schlesinger recommends the following plan for the exam- ination of a mixed fabric containing shoddy: — Examine it with a microscope, and recognize if it contains cotton, or silk, or linen, besides wool. If so, dissolve them by ammoniacal solution of copper. In this way a qualitative examination is first made. Then fix attention on the wool. In shoddy both colored and colorless wool-fibres are often seen, as the fibres have been derived from different cloths which have been jDartiaUy bleached ; the coloring matter, if it remains, is different — indigo, purjDiu-in, or mad- der. The diameter of the wool is never so regular as in fi'esh wool, and it changes suddenly or gradually in diameter, and suddenly widens again with a little swelling, and then thins off again ; the cross marking or scales are also almost obhterated. When liquor potassse is appUed the shoddy wool is attacked much more quickly than fresh wool. The dye also must be good, and of the kind named in the contract, and tests must be applied. Leather. — Choice of leather ; it should be well tanned, and without any marks of con-osion, or attacks of insects. The thinner kind should be per- fectly supple. Leather is not only used for shoes, leggings, and accoutrements ; it is employed occasionally for coats and trousers. It is an extremely warm clothing, as no vrind blows through it, and is therefore well adapted for cold, windy climates. Leather or sheepskin coats are very common in equal surface of linen and flannel being exposed to the air after being placed in equal conditions of absorption, the linen lost in 75 minutes 5.993 grammes, and the flannel only 4.858 grammes of water. Subsequently the evaporation from the linen lessened, as was to be expected, as it was becoming drier ; that from the flannel continued to pass off moderately. The much greater cooling effect of linen is seen. The porosity of clothing, i.e., the rapidity with which air is driven through, is a point to be noted. By an equal pressure equivalent to a column of water 4.5 centi- metres high, an area of 1 centimetre diameter forced air through as follows : — Through linen, 6.03 litres; flannel, 10.41 ; lambskin, 5.07 ; glove-leather, .15 ; wash-leather, 5.37 ; silk-fabric, 4.14. It thus appears that the warmest clothing (flannel) may be the most porous ; mere porosity, in fact, is only one element in the consideration. ' In washing woollen articles, they should never be rubbed or wruyijj. They should be placed in a hot solution of soap, moved about, and then plunged into cold water ; when the soap is got rid of they should be hung up to dry without wringing. CLOTHING. 79 Tiu'key, Tartary, Pei'sia, tlie Danubian Provinces, and everywhere where the cold north winds are felt. In Canada, coats of sheepskin or buifalo- hide have been found veiy useful, and are commonly used by sentries. Waterproof Clothing, — Like leather articles, the india-rubber is an ex- ceedingly hot dress, owing to the same causes, "viz., impermeability to wind, and condensation and retention of perspiration. It is objected to by many on these gTOunds, and especially the latter ; and Le^w informs us that the Council of Health of the French Ai-my have persistently refused (and, in his oi^inion, very j)roperly) the introduction of waterproof gai'ments into the army. If, however, woollen underthings are worn, the perspiration is siifficiently absorbed by those during the comparatively short time water- proof clothing is worn, and the objection is properly not vahd, unless the watei-proof is continually worn. The great use of watei-proof is, of course, its protection against rain, and in this respect it is invaluable to the soldier, and should be largely used. By the side of this great use, all its defects appear to be minor evils. India-rubber cloth loses in part its distensibility in very cold countries, and becomes too distensible in the tropics It is also apt to rot by absoi'p- tion of oxygen. Paraffined cloth is equally good, and the paraffin does not rot the fibre hke common oil. General Conclusions. Protection against Cold. — For equal thicknesses, wool is much superior to either cotton or hnen, and shoidd be worn for all ujaderclothing. In case of extreme cold, besides wool, leather, or waterproof clothing is use- ful Cotton and hnen are nearly equal. Protection against Heat. — Texture has nothing to do with protection from the direct solar rays ; this depends entu-ely on color. White is the best color ; then gray, yellow, pink, blue, black. In hot countries, there- fore, white or light gray clothing should be chosen. In the shade, the effect of color is not marked. The thickness, and the conducting power of the material, are the conditions (especially the former) which influence heat. Protection against Cold Winds. — For equal thicknesses, leather and india- rubber take the first rank ; wool the second ; cotton and hnen about equal Absorption of Perspiration. — Wool has more than double the power of cotton and hnen. Absorption of Odors. — This partly depends on color ; and Stark's observations show that the power of absoi-ption is in this order — black, blue, red, green, yellow, white. As far as texture is concenaed, the absorp- tion is in proportion to the hygi'oscopic absorption, and wool therefore absorbs more than cotton or hnen. Protection against Malaria. — It has been supposed that wearing flannel next the skin lessens the risk of malaiia. As it is generally supposed that the poison of malaria enters either by the lungs or stomach, it is difficult to see how protection to the skin can prevent its action ; except indirectly, by preventing chiU in pei'sons who have already suffered from ague. But the xerj great authority of Andrew Combe, dra-wn from experience at Home, is in favor of its having some influence ; and it has been used on the west coast of Africa for this purpose, with apparently good results. CHAPTER XIV. CLIMATE. It is not easy to give a proper definition of climate. The effect of cli- mate on the human body is the sum of the influences which are connected either wdth the solar agencies, the soil, the air, or the water of a place, and as these influences are in the highest degree complex, it is not at present possible to trace out their effects with any certainty. With regard generally to the effect of climate on human life, it would seem certain that the facihty of obtaining food (which is itself influenced by chmate), rather than any of the immediate effects of climate, regiilates the location of men and the amount of population. The human frame seems to acquire in time a wonderful power of adaptation ; the Eskimos, when they can obtain plenty of food, are large strong men (though nothing is known of their average length of life), and the dwellers in the hottest parts of the world (pro^•ided there is no malaria, and that their food is nutritious) show a stature as lofty, and a strength as great, as any dwellers in temperate chmates. Peculiarities of race, indeed, arising no one knows how, but probably from the combined influences of chmate, food, and cus- toms, acting through many ages, appear to have more effect on stature, health, and duration of hfe, than climate alone. StiU, it would seem prob- able that, in climatic conditions so diverse, there arise some special differ- ences of structure which are most marked in the skin, but may possibly in- volve other organs. How soon the body, when it has become accustomed by length of resi- dence for successive generations to one chmate, can accommodate itself to, or bear the conditions of, the climate of another widely different place, is a question which can only be answered when the influences of climate are better known. The hypotliesis of " acchmatization " implies that there is at first an injurious effect jiroduced, and then an accommodation of the body to the new conditions within a very limited time ; that, for example, the dweller in northern zones passing into the tropics, although he at first suffers, acquii'es in a few years some special constitution which I'elieves him from the iniu.rious consequences which, it is supposed, the change at first brought with it. There are, therefore, two assumptions, \iz., of an injuri- ous effect, and of a relief from it. Are either connect ? It may seem a bold thing to question the commonly received opinion, that a tropical chmate is injurious to a northern constitution, but there are some striking facts which it is difficult to reconcile with such an opinion. The army experience shows that, both in the West Indies and in India, the mortality of the soldier has been gradually decreasing, until, in some stations in the W^est Indies (as, for example, Trinidad and Barbadoes), the sickness and mortality among the European soldiers ai'e actually less than ou home sei-vice in years which have no yellow fever. In India, a century CLIMATE. 81 ago, people spoke witli horror of the terrible climate of Bombay and Cal- cutta, and vet Europeans now live in health and comfort in both cities. In Algeria the French experience is to the same effect. As the climate and the stations are the same, and the soldiers are of the same race and habits, what has removed the dangers which formerly made the sickness three- fold and the moi-tahty tenfold the ratio of the sickness and deaths at home ? The explanation is very simple ; the deaths in the "West Indies were partly owing to the vu'ulence of yellow fever (which was fostered, though probably not engendered by bad sanitaiy conditions), and the general excess of other febrile and dysenteric causes. The simj)le hygienic -pve- cautions which are efficacious in England, have been as useful in the West Indies. Proper food, good water, piure aii', have been supplied, and, in proportion as they have been so, the deadly effects attributed to climate have disappeared. The effect of a tropical chmate is, so to speak, relative. The temperature and the humidity of the ah' are highly favorable to de- compositions of all kinds ; the efHuvia from an impiu-e soil, and the putres- cent changes going on in it, are gi'eatly aggravated by heat. The effects of the sanitary evils which, in a cold chmate like Canada, are partly neuti'alized by the cold, are developed in the West Indies, or in troj^ical India, to the greatest degree. In this way a tropical chmate is evidently most powerful, and it renders aU sanitary precautions tenfold more neces- sary than in the temperate zone. But all this is not the effect of climate, but of something added to climate. Take away these sanitary defects, and avoid malarious soils or drain them, and let the mode of lining be a proper one, and the Eui'opean sol- dier does not die faster in the tropics than at home. It must be said, however, that an element of uncertainty may be pointed out here. In our tropical possessions the Eui'opean soldier seiwes now only for short periods (in the West Indies for thi-ee or four years, in India, under the new regulations of short service, seven or eight years, at most), and dui'ing this time he may be for some years on the hills, or at any rate in elevated spots. The old statistical reports of the ai-my pointed out that the mortality in the West Indies augmented regularly with prolongation of service, and it may be said that, after all, the lessened sickness and mor- tality in the tropics is owing, in some degree, to avoidance by short ser- vice of the influence of chmate. But as the whole long seiwice was constantly passed tmder the unfavorable safiitary conditions now removed, it does not follow that the inference to be chawn from the statistical evi- dence as to length of service is really correct. Facts prove, then, that under favorable sanitary conditions (general and personal), Europeans, during short services, may be as healthy as at home, as far as shown by tables of sickness and mortahty, and it is not certain that long service brings with it different results. It may, however, be urged that, admitting that a non-malarious tropical chmate, per se, may not increase sickness or mortality during the most vigorous years of hfe (and it is then only that Emropeans are usually sub- jected to it), it may yet really diminish health, lessen the vigor of the body, and diminish the expectation of hfe. We have no evidence on the latter point. With respect to the former, it will be well to see what is known of the effects of chmatic agencies on the frame. The influences of locality and climate, as far as they are connected with soil and water, have been sufficiently discussed. The climatic conditions most closely (though by no means solely; connected with air will now be Vol. II. -6 82 PRACTICAL HYGIENE. briefly reviewed. These are — temperature, humidity, movement, weight, composition, and electiicid condition, and the amount of light. SECTION I. TEMPERATURE. The amount of the sun's rays ; the mean temperature of the air ; the variations in temperature, both periodic and non-periodic ; and the length of time a high or low temperature lasts, are the most imjDortant points. Temperature alone has been made a ground of classification. (a) Equable, limited, or insw/ar climates ; i.e., with slight yearly and diur- nal variations. (b) Extreme, exce.'^sive, or continental ; i.e., with great variations. The terms limited and extreme might be applied to the amplitude of the yearly fluctuation {i.e., difference between hottest and coldest month), while equable and excessive might be applied especially to the non-periodic varia- tions, which are slight in some places and extreme in others. A Hmited climate is generally an equable one, and an extreme climate (with great yeai'ly fluctuation) is generally an excessive one (with great un- dulations). The effects of heat cannot be dissociated from the other conditions ; it is necessary, however, briefly to notice them. The efiect of a certain degree of temiDerature on the vital processes of a race dwelling generation after generation on the same spot, is a question which has as yet I'eceived no sort of answer. Does the amount of heat per se, independent of food and aU other conditions, affect the development of mechanical force and temperature, and the coincident vaiious processes of formation and destruction of the tissues ? Is there a difierence in these re- spects, and in the resulting action of the eliminating organs, in the inhabi- tants of the equator and of 50^ or 60^ N. lat. ? This is entirely a problem for the future, but there is no class of men who have more opportunities of studying it than anny surgeons. The problem of the influence of temperature is generally presented to us under the form of a dweller in a tempei'ate zone proceeding to countries either colder or hotter than hi^own. It is in this restricted sense we shall now consider it. With regard to the effect on the Anglo-Saxon and Celtic races of going to live in a climate with a lower mean temperature and gi'eater variations than their own, we have the experience of Canada, Nova Scotia, and some parts of the Northern American States. In all these, if food is good and plentiful, health is not only sustained, but is perhaps improved. The agri- cultural and out-door life of Canada or Nova Scotia is probably the cause of this ; but certain it is that in those countries the European not only en- joys health, but jDroduces a progeny as vigorous, if not more so, than that of the parent race. The effects of heat exceeding the temperate standard must be distin- guished according to origin ; radiant heat, or the direct rays of the sun, and non-radiant heat, or that of the atmosphere. In the latter case, in ad- dition to heat there is moi'e or less rarefaction of the air, and also coinci- dent conditions of humidity and movement of the aii-, which must be taken into account. The influence, again, of sudden transitions from heat to cold, or the reverse, has to be considered. Europeans fi'om temperate climates CLIMATE. 83 flourish, apparently, in countries not much hotter than their own, as in some parts of Australia, New Zealand, and New Caledonia, though it is yet too soon to speculate whether the vigor of the race will improve or other- wise. But there is a geuei'al impression that they do not flourish iu coun- tries much hotter, i.e., with a yearly mean of 20° Fahr. higher, as in many parts of India ; that the race dwindles, and finally dies out ; and therefore that no acchmatization of race occurs. And certainly it would appear that in India there is some evidence to show that the pure race, if not inter- mixed with the native, does not reach beyond the third generation. Yet it seems only right to say that so many cu'cumstances besides heat and the other elements of climate have been acting on the English race in India, that any conclusion oj^posed to acclimatization must be considered as based on scanty evidence. We have not gauged on a large scale the effects of cli- mate pui'e and simple, uncomphcated with malaria, bad diet, and other influences adverse to health and longevity. ' (a) Influence of the Direct Bays of the Sun. — It is not yet known to what temperature the direct rays of the ti-opical sun can raise any object on which they fall. In India, on the ground, the uncovered thermometer will mark 160°, and perhaps 212° (Buist) ; and in this country, if the movement of air is stopped in a small space, the heat in the direct sun's rays can be raised to the same point. In a box, with a glass top, Sir H. James found the thermometer mark 237° Fahr., when exposed to the rays of the sun, on July 14, 1864" In experiments on frogs, when temperature much over the patural amount is apphed to nerves, the electrical ciu-rents through them are lessened, and at last stop.^ E. H. "Weber's observations show that for men the same rule holds good ; the most favorable temperature is 30° E. (= 99.5° Fahr.).* It appears also from Kuhne's experiments that the heat of the blood of the vertebrata must not exceed 113° Fahr., for at that temperature the myosin begins to coagulate.^ Perhaps this fact may be connected with the pathological indication that a very high temperature in any disease (over 110° Fahr.) indicates extreme danger. To what temperature is the skin of the head and neck raised in the tropics in the sun's rays ? No sufficient experiments have been made, either on this point or on the heat in the interior of caps and hats with and with- out ventilation. Doubtless, without ventilation, the heat above the head ia the interior of the cap is very great. It is quite possible, as usually as- sumed, that with bad head-dresses the heat of the skin, bones, and possibly even of the deep nerves and centres (the brain and cord), may be greater than is accordant with perfect preservation of the currents of the nerves, or of the necessary temperature of the blood, or with the proper fluidity of some of the albuminous bodies in the muscles, or nerves. The difficulty of estimating the exact effect of the solar rays is not only caused by the absence of a sufficient number of experiments, but by the common presence of other conditions, such as a hot rarefied, and perhaps ' In India the mortality of Eurasians (that is, the mixed race of British, Portuguese, Hindoo, Malay, blood) mixed in all degrees appears to be below that of the most healthy European service, viz., the Civil Service. Mr. Tait's facts "On the Mortality of Eura- sians " (Statistical Journal, September, 1864) would show that this mixed race will m.aintain itself in India. - Mr. Symons has also obtained temperature above 212° F. by the same means, ^Eckhard, Henle's Zeitsch., Band x., p. 165, 1851. ^ Weber, Ludwig's Phys., 2d ed., vol. i., p. 126. ' Ludwig, Lehrb. der Phys. , Band ii. , p. 732. For a collection of data, see Dr. H. C. Wood, jun., Thermic Fever, 1872, p, 50. 84 PRACTICAL HYGIENE. impure air, and lieat of the body produced by exercise, wliicli is not at- tended by i^erspiration. Two points are remarkable in the history of sun- stroke, viz., the extreme rarity of sunstroke in mid ocean ' and at great ele- vations.'' In both cases the effect of the sun's rays, ^jj: -7.-i-_ 1 C'urries a^vay little heat by direct abstraction, but, if dry, increases evaporation, and in tiiat way may in part counteract its own heating power. Both, probably, act on the structure of the nerves of the shin and on the c jntracility of the cutaneoii? ve.5sels, and may thus induence the rate of evfi.jrrition. and pos^iljly adtct also other organs. T;.e '\:^ j'j.nt of the cooling enect oi moving bodies of air is not easy to detei-^^ii-v, :.s it depends on thr-ee factjrr-, viz., the velocity of movement, the ten/.: Tiuture. and the hunii'dity of the air. The effect of movement is very Li-iit, In a c:dm atmosjjhere an extremely wai-m temperature is borne without difficulty. In the Ai'ctic expeditions calm air many de- grees below zero of Fahr. caused no discomfort. But any movement of such cold ail' at once chills the fi'anie. It has been asserted that some of the hot anl very dry desert winls will, in spite of their wannth, chill the bci:!" : :.:_ 1 :: ^ .it can scarctly Ijt tr :.. .ny other reason than the enor- mon- -■■ . .:: n tn^v r:iuse n'Oin Ii^l- .~„in. It is very de.su'able, however, that ti.i- - : ti :. -i;tild be rej)eatecL with careful ther-mometrical ol> servati'.'n.^ u^jtn on inc uody in the usual way and on the sui-face of the shin, SECTIOX IV. WEIGHT OF THE AIE. Effects of Consider f:']^ L-^^-^'xing of Pressure. "When the difference of press vne 1 jf>*ween two places is considerable, a ni:.:".:- 1 en- " i- ^ r 1 icel. and ther-r seems no doubt that the influence of nijnn-.in i.j .Inn.-- n IcStinei to be of .sreat impoi'tance in therapeutics. It is of r.'-jnliar int-r^-~t X\i tn- arniv surne'jn. as so many regiments in the tropics ai'e, ox '^.ilj. ijr. cjuarterel at c-cnsnleraljle elevations. In ascenan._ :__:untain3 there is rarefaction, i.e., lessened pressure of air ; on an aTein.._c ^if the weight of the air at sea-level is 15 fe on every square inch) an ascent of 'jc'ij feet takes off -J- ft) ; but this varies with height ; there are also lowere 1 ttmperature, and lessened moisture above 4,ij'jij :-.--". _r- :.:er movement of the air, increased amount of Hghts greater sun 1:. iiation.. if clouls are absent: the air is fi-eer from genns of ia- tn- ::. ; owin^ to the raiefaction of the air and lessened watery vapor, ther'z- i- giTater diathermancy of the au' ; the soil is rapidly heated, but ra'dif.tr- :J- c fa-t. as ti^e heat is not so much held back by vapor in the air, hen:n there is very great coohn,g of the ground and the ah close to it at nignt. The physiological effects of lessened pressui-e begin to be perceptible at 2, SCO or 3,000 feet of altitude ( = dtscent of 2s-~'to 3 hiches of mer- cui'v 1 : they are — quickened pulse ' (fifteen to twenty beats per minute) ; ' Balloon ascents. — Biot & Gav-Lusac at 9,000 ft. =increase of 18-30 beats of pxilse. Glaisher .' .at 17,000 " — " of 10-24 *' Glaislier . . . . .at 24,000 " = " of 24-31 " Tr.^ leat; seem to aBgment in number witb tbe elevation. These are safer numbers tV.i- -':. - c' .ii.Ti in mountain ascents, as there is no physical exertion. In nionn- "iii- - iJ. 1 - :1-T i II crease is much greater. 90 PEACTICAL HYGIENE. quickened respiration (increase = ten to fifteen respirations per minute), with lessened spirometrie capacity,' increased evaporation from skin and lungs ; lessened luinary water. '^ At gi*eat heights there is increased pressui'e of the gases in the body against the containing parts ; swelling of suiDerficial vessels, and occasionally bleeding from the nose or lungs. A sensation of weight is felt in the hmbs from the lessened pressure on the joints. At altitudes under 6,000 or 7,000 feet the effect of mountain air (which is, perhaps, not owing solely to lessened j^ressure, but also, possibly, to in- creased hght and pleasurable excitement of the senses) is to cause a very marked improvement in digestion, sanguification, and in nervous and muscidar vigor.' It is inferred that tissue change is accelerated, but nothing definite is known. The rapid evaporation at elevated positions is certainly a most im- portant element of mountain hygiene. At Puebla and at Mexico the hygrometer of Saussui-e wiU often mark 37', which is equal to only 45 per cent, of satxu-ation,* and yet the lower rooms of the houses are very humid, so that, in the town of Mexico, there are really two chmates, — one very' moist, in the rez-de-chaussee of the houses ; one veiy day, in the upper rooms and the outside air. The diminution of oxygen, in a certain cubic space, is precisely as the pressure, and can be calculated for any height, if the bai'ometer is noted. Taking chy air only, a cubic foot of aii- at 30 inches, and at 32° Fahr., con- tains 130.4 gi-ains of oxygen. An ascent (about 5,000 feet) which reduces the barometer to 25 inches will lessen this -Jth, or I ^ — '—= \ 108.6 grains. But it is sujjposed that the increased number of resphations compensate, or more so, for this ; and, in addition, it must be remembered that in experi- ments on animals, as long as the percentage of oxygen did not sink below a certain point (14 per cent.), as much was absorbed into the blood as when the oxygen was in normal proportion. Jourdanet has indeed asserted ° that the usual notion that the resi^u-ations are augmented in number in the inhabitants of high lands is " completely eiToneous ;" that the respu'ations are in fact lessened, and that from time to time a deeper resj^iration is voluntaiily made as a partial compensation. But Coindet, from 1,500 observations on French and Mexicans, does not confirm this; the mean number of respirations was 19.36 per minute for the French, and 20.297 for the Mexicans. As a curative agent, mountain air (that is, the consequences of lessened pressiu'e chiefly) ranks very high in all anamic affections from whatever cause (malai'ia, hemorrhage, digestive feebleness, even lead and mercury poisoning) ; and it would appear, from Hermann "Weber's obsei-vations, that the existence of valvular heart disease is, if proper i-ules are observed, no contradiction against the lower elevations (2,000 to 3,000 feet). Neuralgia, gout, and rheumatism are all benefited by high Alj^ine positions (H. Weber). Scrofula and consumption have been long known to be rare among the dwellers on high lands, and the cui-ative effect on these diseases of such places is also marked ; but it is possible that the open au' hie which is led ' Battraj found an ascent of 2,000 feet (at Ascension) lessened the "vital capacity," as judged of by the spirometer, from 266 to 249 and 243 cubic inches. ■■' Vivenot, Virchow's Archiv, 1860, Band xix., p. 492. This is probable, but not jet proved. ^ Hermann Weber. Climate of the Swiss Alps, 1864, p. 17. ■* Jourdanet. Du 3Iexique, p. 49. * Du Mexique, p. 76. CLIMATE. 91 has an influence, as it is now known that great elevation is not necessaiy for the ciu-e of phthisis.' Dr. Hermann Weber, in his important work on the Swiss Alps (p. 22), has given the present evidence, and has shown how in the true Alpine region— in Dauphin e, in Peru and Mexico, and in Germany — phthisis is decidedly averted or prevented by high altitudes. The more recent ex- perience of Davos Platz is confirmatory. Although on the Alps phthisis is arrested in strangers, in many places the Swiss women on the lower heights suffer greatly from it ; the cause is a social one ; the women employed in making embroidery congregate all day in small, ill-ventilated, low rooms, where they are often obhged to be in a constrained position ; then- food is poor in quality. Scrofula is very common. The men who hve an open-air life are exempt ; therefore, in the very place where strangers are getting well of phthisis the natives die from it — another instance that we must look to local conditions and social habits for the great cause of phthisis. If would even seem possible that, after aU, it is not indeed elevation and rarefaction of air, but simply plenty of fresh air and exercise, which are the great agents in the cure of phthisis. Jourdanet, who differs from so much that is commonly accepted on this point, gives additional evidence on the effect of elevation on phthisis. _ At Vera Cruz phthisis is common ; at Puebla and on the Mexican heights, it is almost absent {d peu pres nulle). The diseases for which mountain air is least useful are — rheumatism, at the lower elevations where the air is moist ; above this rheumatism is improved ; and chronic inflammatory affections of the respiratory organs (?). The "mountain asthma" appears, however, from Weber's observations, to be no specific disease, but to be common pulmonary emphysema following chronic bronchitis. It seems likely that pneumonia, pleurisy, and acute bronchitis are more common in higher Alpine regions than lower down. IJfeds of Increased Pressure. — The effects of increased pressure have been noticed in persons working in diving-beUs, etc., or in those submitted to treatment by compressed air. (At Lyons and at Eeichenhall ' especially.) When the pressure is increased to from 1^ to 2 atmospheres, the pulse becomes slower, though this varies in individual cases ; the mean lessening is 10 beats per minute ; the respirations are sHghtly lessened (1 per minute); evaporation from the skin and lungs is said to be lessened (?) ; there is some recession of blood from the peripheral parts ; there is a little ringing and sometimes pain in the ears ; hearing is more acute ; the urine is in- creased in quantity ; appetite is increased ; it is said men will work more vigorously. When the pressure is much greater (two or three atmospheres) the effects are sometimes very marked ; great lowering of the pulse, heavi- ness, headache, and sometimes, it is said deafness. It is said ° that more oxygen is absorbed, and that the venous blood is as red as the arterial ; the skin also sometimes acts more, and there may even be sweating. The > Some time ago a remarkable paper was published by Dr. James Blake, of California, on the treatment of phthisis (Pacific Medical Journal, 1860). He adopted the plan of making his patients live in the open air; in the summer months he made them sleep out without any tent ; the result was an astonishing improvement in digestion and sanguification ; the resistance to any ill effects from cold and wet is described as marvellous. As Dr. Blake is well known to be perfectly trustworthy, these statements are worthy of all consideration. 2 For an account of the effects noted at Eeichenhall, see Dr, Burdon-Sanderson's account in The Practitioner, No. iv., 1868, p. 221. ^ Foley, ''Du Travail dans I'air comprime," Gaz. Hebdom., 1863, No. 33. 92 PRACTICAL HYGIENE. main effect is to lessen the quantity of blood in the veins and auricles, and to increase it in the arteries and ventricles ; the filling of the ventricle during the relaxation takes place more slowly. The diastohc interval is lengthened, and the pulse is therefoi'e slower. Wlien the workmen leave the compressed air they are said to suffer from hemorrhages and occasional nervous affections, which may be from cerebral or spinal hemoiThage.' As a curative agent in phthisis, the evidence is unfavorable. Some observations lately made by M. Bert ^ show that oxygen, when it enters the blood under pressure (such as that given by 17 atmospheres of atmospheric ah", or 3^ atmospheres of jDure oxygen), is toxic to birds, pro- ducing con^Tilsions. Convulsions are produced in dogs when the pressure is only 7 or 8 atmospheres, and when the oxygen amounts to only double the normal amount, or, in other words, reaches 32 C.C. per 100 C.C. of blood. M. Bert conjectures that the toxic influence of oxygen is on the nervous centres, like strychnine. The animal temperatm-e fell 2 or 3 degrees (C.) during the convulsions, so that excess of oxygen did not cause increased combustion. In the case of a dog kept under a pressure of 9^ atmospheres for some time, gas was found in the ventral ca\-ity and in the areolar tissue. In man the pressure of only 5 atmospheres appears to be dangerous.' 7s Acclimatization possible ? The doctrine of acclimatization has been much debated, but probably we do not know suflficiently the physiological conditions of the body mider different circumstances. In the case of Europeans li\dng till puberty in a temperate region, near the sea-level, and in a moist climate like England, and then going to the tropics, the question of acclimatization would be put in this form, — Does the body accommodate itself to greater heat, to lessened humidity in some cases, or greater in others, and to vaiying altitudes ? There can be little doubt that the body does accommodate itself within certain limits to greater heat, as we have seen that the lungs act less, the skin more, and that the circulation lessens when Englishmen pass into the tropics. There is so far an accommodation or alteration impressed on the functions of the body by unwonted heat. And we may believe that this effect is permanent, i.e., that the lungs continue to act less, and the skin more, as long as the Europeans remain in the tropics. Doubtless, if the race were perpetuated in the tropics, succeeding generations would show fixed alterations in these organs. We may conclude that the converse holds true, and that the cold of temperate regions will influen,ce natives of the tropics in an opposite waj', and this seems to he rendei'ed likely by the way in which lung affections arise in many of them. We may admit there is an acclimatization in this sense, but in no other. The usual belief that the constitution acquires in some way a power of ' See Limousin, in Canstatt, 1863, Band ii., p. ^05, and Eabington in Dublin Quarterly Journal, November, 1864. - Chemical News, March 28, 1873. ' In the colliery accident at Pont-y-Prydd, several men were confined for ten days in a small space, in which the air was much compree-sed. The exact pressure is un- known, but it was sufficient to drive one of the men, with fatal force, into the opening made for their rescue Although the men were without food all the time, they appeared to have suifered leos than might have been anticipated. CLIMATE. 93 resisting unhealtliy influences— that is, a power of not being any longer susceptible to them — is not supported by any good evidence. The lungs in Europeans will not regain their weight and amount of action in the tropics ; a change to a cold climate only will cause this ; the skin retains its increased function until the cause producing it is removed. So also there is no acclimatization in any sense of the word for malaria. SECTION V. COMPOSITION OF THE AIR. The proportionate amounts of oxygen and nitrogen remain very constant in all countries, and the range of variation is not great. So also, apart from the habitations of men, the amount of carbon dioxide is (at elevations occupied by men) constant. The variations in watery vapor have been already noticed. The only alterations in the composition of the air which come under the head of climate, are changes in the state in which oxygen exists (for do change is known to occur in nitrogen), and the presence of impurities. Sub-Section I. — Ozone. Ozone is now admitted by most chemists to be an allotropic condition of oxygen ; and, as conjectured by Odling, it is now believed that it is a compound molecule made up of thi-ee molecules (0.,0) of oxygen. The so-called antozone is now believed to be peroxide of hydrogen diffused in a large quantity of atmospheric air. Variations in the amount of ozone have been supposed to be a cause of chmatie difference, but, in spite of aU the labor which has been given to this subject, the evidence is very uncon- clusive. The reaction with the ozone paper is liable to great fallacies.' Yet it seems clear that some points are made out ; the ozonic reaction is greater in pure than impure air ; greater at the seaside than in the interior ; greater in mountain air than in the plains ; absent in the centre of large towns, yet present in the suburbs ; absent in an hospital ward, yet present in the air outside. In this country it is greater with south and west -^dnds ; greater, according to Moffat, when the mean daily temperature and the dew-point temperature are above the mean ; the same observer found it in increased quantity with decreasing readings of the barometer, and con- versely in lessened quantity with increasing readings. The imperfections in the test render it desirable to avoid drawing con- clusions at present ; but one or two points must be adverted to. 1. Owing probably to the oxidizing power of ozone when prepared in the laboratory, a great power of destruction of organic matter floating in the air has been ascribed to ozone by Schonbein, and the absence of ozone in the air has been attributed by others to the amount of organic matter in the air of towns. Even the cessation of epidemics (of cholera, malarious fevers) has been ascribed to currents of air bringing ozone with them. The accumulation of malaria at night has been ascribed to the non-production of ozone by the sun's rays (Uhle). The effect of stagnant air in increasing epidemics has also been ascribed to the absence of ozone. It seems clear that the substance giving the reaction of ozone is neither ' The subject of ozone will be found fully discussed by Dr. C. Fox (Ozone and Antozone, 1873j. The causes of fallacy in the tests are carefully explained. 94 PRACTICAL HYGIENE. deficient in marshy districts, nor when ozone is conducted through marsh dew does it destroy the organic matter.' 2. On account of the irritating effect of ozone, when rising from an electrode, Schimbein believed it had the power of causing catan-h, and inferred that epidemics of influenza might be produced by it. He attempted to adduce evidence, but at present it may safely be said that there is no proof of such an origin of epidemic catarrhs. 3. A pojDular opinion is, that a climate in which there is much ozone (ie., of the substance giving the reaction with iodide and starch paper) is a healthy, and, to use a common phi'ase, an exciting one. The coincidence of excess of this reaction with pure air lends some support to this, but, Hke the former opinions, it still wants a sufficient experimental basis. On the whole, the subject of the presence and elfects of ozone, curious and interesting as it is, is very uncertain at present ; experiments must be numerous, and inferences drawn from them must be received with caution. Sub-Section II. — Malaeia. The most important organic impurity of the atmosphere is malaria, and when a climate is called "unhealthy," in many cases it is simply meant that it is malarious. In the chapters on Soils and Air the most impoi'tant hygienic facts connected with malaria have been noted. In this place it only remains to note one or two of the climatic points associated with malaria. 1. Vertical Ascevt. — A marsh or malarious tract of country existing at any point, what altitude gives immunity from the malaria, supposing there is no drifting up ravines ? It is well known that even a slight elevation lessens danger — a few feet even, in many cases, but complete security is only obtained at greater heights. Low elevations of 200 to 300 feet are often, indeed, more malarious than lower lands, as if the malaria chiefly floated up. At present the elevation of perfect security in different parts of the world is not certainly determined, but appears to be — Italy 400 to 500 feet.' America (Appalachia) 3,000 " Cahfornia ' 1,000 " India 2,000 to 3,000 " West Indies 1,400 to 1,800 up to 2,200 feet. But these numbers are so far unceriain that it has not always been seen that the question is not, whether marshes can exist at these elevations (we know they can be active at 6,000 feet), but whether the emanations from a marsh will ascend that height without drifting up ravines ? 1,000 to 1,200 feet would generally give security in all probabiUty. 2. Horizontal Spread. — In a calm air L6vy * has supposed that the malaria will spread until it occupies a cube of 1,400 to 2,000 feet, which is equivalent to saying it will spread 700 to 1,000 feet horizontally from the central point of the marsh. But cun'ents of air take it great distances, though the best observations show that these distances are less than were ' In addition to what has been previously said (Vol. I., p. 131), Grellois has lately stated that he found more ozone over a marsh than elsewhere. An interesting series of observations on ozone in the Bombay Presidency has been made by Dr. Cook. - Carriere, quoted by Levy, t. i., p. 491. • This information was given Dr. James Blake. ■• T. i., p. 464. CLIMATE. 95 supposed, and seldom overpass one or two miles, unless tlie air-currents are rapid and strong. The precise limits are unknown, but it is very doubtful if the belief in transference of malaria by air-currents for 10, 20, dr even 100 miles, is coi-rect. * 3. Spread over Water. — The few precise observations show that this differs in different countries. In the Channel, betweeii Beveland and Walcheren, 3,000 feet of water stopped it (Blane). In China and the West Indies a farther distance is necessary. Li China three-quarters of a mile has been effectual ; ' in the West Indies one mile. Grant thinks that salt water is more efficacious than fresh. SECTION VI. ELECTRICAL CONDITION— LIGHT. That these, as well as heat, are important parts of that complex agency we call Climate, seems clear ; but little can be said on the point. In hot countries positive electricity is more abundant ; but the effect of its amount and variation on health and on the spread and intensity of diseases is quite unknown. All that has been ascribed to it is pure speculation. The only certain fact seems to be that the spread of cholera is not influenced by it. With regard to light, the physiological doctrine of the necessity of light for growth and perfect nutrition makes us feel sure that this is an im- portant part of climate, but no positive facts are known. Grant (quoted by CLevers), Indian Annals, 1859, p. 636. CHAPTER Xy. DESCRIPTION OF THE METEOROLOGICAL INSTRUMENTS, AND A FEW REMARKS ON METEOROLOGY. . As meteorological observations are now so commonly made, and as iu the azTny instruments are pro\dded at many foreign stations, it is desirable to give a few plain instructions on the use of these instmments. ' For the convenience of beginners, a few observations on Meteorology are also added. ' The following is tlie oflBcial circular issued by the Army Medical Department : — Official Instructions for Reading the Meteorological Instruments. Tlie observer should make himself thoroughly acquainted with the scale of every instrument, especially with that of the barometer and its attached vernier, and by fre- quent comparisons ascertain that he and his deputy read the instruments alike, and record the observations accurately. All observations must be recorded exactly as read. The corrections are to be made only at the end of each month on the " means" of the " sums." Barometrical observations must be recorded to the third decimal place ; thermomet- rical to the first decimal. When the readings are exactly to the inch or degree, the places for the decimals must be filled up with ciphers. The observations should be made as quickly as possible, consistent with perfect accuracy, and the observer must avoid breathing on the instruments, particularly the dry and wet bulb, and maximum thermometers. Barometer Readings. — Note the temperature of attached thermometer in degrees only ; by means of the thumb-screw at the bottom adjust the mercury in the cistern to its proper level, the point of the ivory cone, which should just touch the mercury with- out breaking the surface ; then bring the zero line of the vernier to the level of the apex of column of the mercury, and read off in the manner described at pages 15 and 16 of Sir H. James's Book of Instructions. - Tliermometer Readings. — The scales are divided to degrees only, but these are so open that the readings can be determined to the tenth of a degree. Practice and at- tention will insure accuracy. Maximum Tliermometer in Shade. — The maximum thermometer must be hung at such a distance (2 or 3 inches) from the water-vessel of the wet-bulb thermometer, that its readings may not be affected by evaporation. In hanging the maximum, care must be taken that the end of the tube is slightly indined doicnirard, which will have the effect of assisting in preventing the return of any portion of the column of mercury into the bulb on a decrease of temperature. To read the instrument, gently elevate the end furthest from the bulb to an angle of about 45 °, in which position of the instrument note the reading. To re-set the ther- mometer, a gentle shake or swing, or a tap on the wooden frame of the instrument, will cause the excess of mercury to return to the bulb, and it is again ready for use. Maximum in Sun^s Rays, or the Vacuum Solar Radiation Thermometer.- — Being con- structed on the same principle as the last-mentioned instrument, it must be read in a similar position. After completing the reading, by giving the instrument a slight - For these are now pubstitnted Instructions in the Use of Meteorological Instruwents, by R. H. Scott, M.A., F.B.S., 1877. The Barometer corrections are explained at pp. 30, 31 of that work. DESCRIPTION OF ilETEOROLOGICAL IXSTEUMFJSTTS. 97 SECTION L THEEMOMETERS FOR TAKING THE TEMPERATURE OF THE AIR. Maximum Thermometers. Two maximum thermometers are issued — one to observe tlie greatest heat in the sun, the other in the shade. The Su?i 3Iaximum or Solar Eadiation Thermometer is formed by a glass case (from which the aii" is removed), containing a mercurial thermo- shake, with th.e bulb still inclined downward, tlie excess of mercury will return to tlie bulb, and the thermometer be ready for the next observation. Minimum ThenrMmeter in Shude. — The minimum thermometer must be so hung that the bulb may be about one inch lower than the other extremity of the instrument, because in this position the index is less likely to be affected by a rise in temperature. The extremity of the index furthest from the bulb shows the lowest degree to which the spirit has fallen since the last observation. The reading on the scale cor- responding to this is the temperature to be recorded. Then by elevating the bulb, the index will float toward the end of the spirit. When it has jiearly arrived at that pointy the instrument is re-set. Minimum on Grass, Terrestrial BadMtion Thermometer is constructed like the last, and the directions above given are also applicable to it. After reading and re-setting the self -registering thermometers, compare them with the dry-bulb thermometer in order to ascertain that their readings are nearly the same. Dry and- Wet-Bulb Thermometers. — Bring the eye on a level with the top of the mercury in the tube of the dry-bulb thermometer, and take the reading, then complete the observation by noting in like manner the reading of the wet-bulb thermometer. The temperature of the air is given by the former, that of evaporation by the latter. From these data the hygrometrical results are to be calculated by Glaisher's Tables, 3d edition. ' Bain-Oauge and Measure. — Pour the contents of the gauge into any convenient ves- sel with a lip, and from this into the glass measure, which has been graduated especi- ally for the gauge, and is only to be used in measuring its contents. It is graduated to the hundredths of an inch. Anernorneters. — The dials are read from left to right. The first on the left records hundreds of miles, the second tens, the third miles, the fourth tenths of a mile, and the-fifth hundredths of a mile. The reading of the anemometer is obtained by deducting from the amount registered by the dials the total sum registered at the period of the preceding observation. The difference between those (subject to a small correction) indicates the velocity or hori- zontal movement of the air in miles during the interval, and must be entered in the return. When the instrument is first set up, the reading on the dials must be noted, in order that it may be deducted from the total registered by the dials at the end of the first period o£ observation. In making observations on the presence of ozone, a box has been found to be unne- cessary, equally satisfactory results having been obtained by fixing the paper immediately under the penthouse of the stand, which shelters it sufficiently from a strong light, while it secures proper exposure. The minimum thermometers are liable to get out of order — first, by carriage, when the index may be wholly or partly driven out of the spirit, or a portion of spirit may become detached from the main column ; and, secondly, by slow evaporation of the spirit, which rising in the tube, condenses at the upper end. The first-mentioned errors are corrected by taking the thermometer in the hand, with its bulb downward, and giving it a swing up and down. The second is remedied by the inclined position of the instrument, which allows the condensed spirit to trickle back to the main column.'^ -ZV^. B. — On no account whatever is artificial heat to be applied to a spirit thermo- meter. In re-setting the minimum, the index should never be brought quite to the end of the column of spirit. ' A 6th edition is now published. 2 It is generally necessary to swing the instrument to get back the broken portion of the column. Vol. II.— 7 98 PRACTICAL HYGIENE. meter with a blackened bulb. The case shelters from cun-ents of air ; the black bulb absorbs the sun's rays. The tube of the thei-mometer is shghtly bent neai- the bulb, and a piece of porcelain is inserted which narrows the tube. The efi'ect of this is to make the thermometer self-registering, as, after the mercur}' has expanded to its fullest extent, instead of retii-ing into the bulb on cooling, it is stopped by the porcelain, and the merciuy breaks between the porcelain and the bulb. The instrument is placed at a height of four feet from the ground on wooden supports, and in any place where the sun's rays can fi-eely fall on it. The Shade Maximuia is a mercurial theiTQometer, not inclosed in a case, but mounted on a fi-ame. Its construction and manner of reading are otherwise similar to those of the sun thermometer. It is placed in the shade foirr feet above the gi'ound, and sufficiently far fi'om any walls to be unaffected by radiation. It should be freely ex- posed to the air, but perfectly protected from the sun's rays. Minimum Thermometers.^ Two minimum thermometers are supplied. The Shade Minimum is an alcoholic thermometer with a small index in the alcohol It is set by allowing the index to shde nearly to the end of the spii'it ; as the spirit contracts during cold, it cames the index do-Rii ; when it expands again it cannot move the index, but leaves it at the degi-ee of gTeatest cold. The end of the index farthest fi'om the bulb is the point to read. This thei-mometer is placed in the shade fom- feet above ground, under the same conditions as the shade maximum. The Grass Minimum or Terrestrial Radiation Thermometer is a thermo- meter of the same kind, but protected by a glass shield. It is placed al- most close to the ground on grass, suspended on little tripods of wood, but it should not touch the gi-ound ; it is intended to indicate the amount of cooling jDroduced by radiation from the ground. If snow hes on the ground the bulb should be placed in the snow. Scott recommends a black board on which to lay the thermometer where no grass can be obtained.'' Common Thermometer. The dry bulb of the " wet and dry bulb thermometer " is read as a common thermometer. Reading of the Thermometers. All these thermometers can be read to tenths of a degree. The maxi- mum and minimum thermometers are read once a day, usually at 9 a.m. ; the foi-mer marks the highest point reached on the previous afternoon, and must be so entered on the retui-n ; the latter, the lowest point reached on the same morning.^ For the army returns the common thermometer is read twice a day, at 9 a.m. and 3 p.m. ' Great diflBculty is found with spirit thermometers on account of their being so much less sensitive than mercurial. To remedy this the bulb is sometimes made fork- shaped, or otherwise modified so as to expose as large a surface as possible. '■' Instructions, etc. Scott adds: " Under any circumstances, a board gives a better measure of terrestrial radiation than grass. " ^ It is desirable that these thermometers should be read both morning and evening. In winter the maximum sometimes occurs in the early morning and the minimum in the afternoon. In winter the range depends more on the direction of the wind descriptio:n" oe meteoeological instkumejn'ts. 99 Range of the Temperalare. — The maximum and minimum in shade giye most important chmatic indications ; the difference between them on the same day constitutes the range of the diurnal fluctuation. The range is expressed in several ways. The extreme daily range in the month or year is the difference between the maximum and minimum thermometer on any one day. The extreme monthly or annual range is the difference between the gi'eatest and least height in the month or year*. The mean monthly range is the daily ranges added and divided by the number of days in a month (or between the mean of all the maxima and the mean of all the minima). The 3'early mear, I'ange is the monthly ranges added and divided by 12. Mean Temperature. — The mean temperatui-e of the day is obtained in the following ways : — (a) At Greenwich and other observatories, where by means of photo- gi'aphy the height of the thermometer at every moment of the day is regis- tered, the mean of the hourly readings is taken. This has been found to accord with the absolute mean (foimd by taking the mean of the whole curve) to within -^Qih of a degree. ip) ApiDroximately in several ways. Taking the mean of the shade maximum and minimum of the same day. la this country, during the cold months (December and Januaiy), the result is very close to the truth ; but as the temperatui'e increases, a greater and greater en-or is produced, until in July the mean monthly error is + 1.9^ Fahr., and in some hot days is much greater. In the tropics, the mean of the maximum and minimum must give a result still further from the truth. Monthly corrections can be applied to bring these means nearer the truth. Islx. Glaisher's corrections for this country are as follows : — Subtract fi'om the monthly mean of the maximum and minimum de- grees — January, 0.2 May, 1.7 September, 1.3 Februaiy, 0.4 June, 1.8 October, 1.0 March, 1.0 July, 1.9 November, 0.4 April, 1.5 August, 1.7 December, 0.0 The result is the ajDproximate mean temperatui'e. But this is true only for this country.' In a great number of places the mean temperature of the day and year, as stated in books, is derived solely from the mean of the maximum and minimum.- According to Scott, the approximation to the time mean is very close in most parts of the world, especially if the obseiwations be taken as near the end of the period as possible, near midnight, for instance, for the mean of the civil day of twenty-four hours. The approximate mean temperature may also be obtained by taking observations at certain times diu'ing the day, and applying a correction. than on the time of day (Scott). But iiuiformity of practice is the primary essential, and at stations where observations are made only once a day, viz., at 9 A.M., or even twice, unless the second reading is after 6 p.m., the above rule as to entry must be fol- lowed. ' These numbers of Mr. Glaisher are likely to be modified very considerably ; they are largely dependent on the pattern of the thermometer stand employed. - With a Stevenson screen the simple mean of the maximum and minimum is very near the truth. 100 PRACTICAL HYGIENE. Mr. Glaislier has given some very valuable tables of this kind,' which can be consulted." If the temperature be taken twice a day at homonymous hours, such as 9 A.M. and 9 p.^t., the mean of these does not differ much from the true daily mean (Scott). The nearest approach to the mean temperature of the day by a single obsen-ation is given at from 8 to 9 p.m. ; the next is in the morning — about 8 o'clock in July and 10 in December and January. The neai'est approach to the mean annual temperature is given by the mean of the month of October. Observations made from a week before to a "week after April 2-4th, and again in the con-esponding weeks of October, give a certain approximation to the yearly mean temperature.^ The changes in temperature of any place, duiing the day or year, are either periodic or non-periodic. The former are dependent on day and night, and on the seasons, i.e., on the position of the place with respect to the sun. The periodic changes are sometimes termed fluctuations, and the differences between day and night temperatiu-es, or the temperatiu-es of the hottest and coldest months, are often called the araphtudes of the daily or yearly fluctuations. Daily Periodic Changes. — On land the temperature of the air is usually at its lowest about 3 o'clock a.m., or just before sunrise, and at its maximum about 2 o'clock p.m. ; it then falls nearly regularly to 3 o'clock a.m. At sea, the maximum is nearly an hour later. The amount of diurnal periodic change is greater on land than on water ; in the interior of continents than by the sea-side ; in elevated districts than at sea-level. As far as land is concerned, it is least on the sea-coast of tropical islands, as at Kingston in Jamaica, Colombo in Ceylon, Singapore, etc. Yearly Periodic Changes. —In the northern hemisphere, the coldest month is usually January ; in some parts of Canada it is February. On the sea, the coldest month is later, \iz., March. The hottest month is in most places July, in some few August ; on the sea it is always August. The coldest days in this countiy are toward the 21st January ; the hottest, about the 18th to the 21st July. At Toronto the hottest day is 37 days after the summer solstice ; and the coldest, 55 days after the winter sol- stice. It is thus seen that both for the diurnal and annual alterations of heat the greatest heat is not simultaneous with, but is after, the culmination of the sun ; this is owing to the slow absorption of heat by the earth. The amplitude of the yearly fluctuation is greater on land than sea, and ' On tlie Corrections to be applied to Meteorological Observations for Diurnal Range, prepared by the Council of the British Meteorological Society, 1850. These corrections are applicable only to this country. • The following rules, which are applicable in all parts of the world, are given by Herschel : — ■■ If observations are taken three times daily — at 7 A.M., 2 P.M., and 9 P.M., — hours which we mav denote bv t, t, and t" ; then 2 = mean temperature of day. If the hours are 8 A.M., 3 P.M., and 10 P.M., the formula is — 7 t+7 i+10 t" 24 ' Herschel, Meteorology, p. 180. = mean of day. ■* Meteorology, p. 173. DESCRIPTION" OF METEOEOLOGICAL INSTEUMENTS. 101 is augmented by land, so that it reaches its highest point in the interior of great extra-tropical continents. It increases toward the pole for three reasons, — 1. The geographical fluctuation of the earth's position causes a great yearly difference of the angle with which the sun's rays fall on the earth. 2. The duration of incidence of the sun's rays {i.e., the number of hours of sunshine or shade) have greater yearly differences than in the tropics. 3. In the northern hemisphere especially there is a very great extent of land, which increases radiation. The amphtude of the yearly fluctuation is very small in the tropical lands at sea-level. At Singapore, it is only 3.6'' Fahr. (January 78°, July 82.4°), while it is immense on continents near the pole. At Jakoutsk, in North Asia, it is 112.5° (January -445° and July + 68). All fluctuations depend to a large extent upon the distance from the sea, although local causes may have some influence, such as the vicinity of high lands. In any place there may be great undulations and small fluctuations, or great changes in each way. At Brussels, the greatest possible yearly un- dulation is 90°. In some parts of Canada, immense undulations sometimes occur in a day, the thermometer ranging even 50° to 70° in one day. The hot winds of the rainless deserts have long puzzled meteorologists ; they often cause enormous undulations, 50° to as much as 78° Fahi-. Temperature of the Air of any Place. This depends on the following conditions : — 1. Geographical Position as influencing the Amount and Duration of Sun's Bays which are received. — The nearer the equator the hotter. For 23|-° on either side the equator the sun's rays are vertical twice in the year, and are never more oblique than 47°. The mean yearly temperature of the equator is 82° Fahr. ; of the pole about 2.5° Fahr. The decline from the equator to the pole is not regular ; it is more rapid from the equator to 30° than in the higher latitudes. 2. Belative Amount of Land and Water. — The sun's rays passing through the air with but trifling loss fall on land or on water. The specific heat of land being only one cjuarter that of water, it both absorbs heat and gives it out more rapidly. Water, on the other hand, absorbs it more slowly, stores up a greater quantity, and parts with it less readily. The temperature of the superficial water, even in the hottest regions, seldom exceeds 80° to 82°, and that of the air is generally below (2° to even 6°) the temperature of the water (J. Davy). Consequently the more land the greater is the heat, and the wider the diiuTial and yearly amphtudes of fluctuation. The kind of soil has a great effect on absorption. The evapoi'ation from the water also greatly cools the air. 3. Elevation of the Place above the Sea-level. — The greater the elevation the colder the aii', on account — 1st, of the lessening amount of earth to ab- sorb the sun's rays ; and, 2d, on account of the greater radiation into free space. The decline of temperature used to be reckoned at about 1° Fahi*. for each 300 feet of ascent, but the balloon ascents of Mr. Welsh, and es- pecially of INIr. Glaisher, have proved that there is no regtilar decHne ; there are many cur-rents of warm air even in the upper atmosphere. Still the old rule is useful as an approximation. The amotmt of decline varies, how- ever, in the same place at different times of the year. In jMi'. Glaisher's balloon ascents, in a cloudy sky, it was about 4° Fahr. for each inch of 102 PEACTICAL HYGIENE. barometric fall, at first ; but when the barometer had fallen 11 inches, the decline of temperature was more rapid. Under a clear sky there was a fall of 5° Fahr. for each of the first tour inches of descent ; then 4° per inch till the thirteenth inch of descent, and then 4.5° for fourteenth, fifteenth, and sixteenth inches of descent. The snow-line at any spot, or the height at which snow will lie the whole year, can be approximately reckoned by taking the mean yearly temperature of the latitude at sea-level, and multiplying the difierence between that tem- perature and 32° Fahr. by 300. The aspect of a place, however, the dis- tance from the sea, and other circumstances, have much to do with the height of the permanent snow-line. The mean temperature of any place can be apjDroximately reckoned in the same way, if the mean temperature of the latitude at sea-level, and the elevation of the place in feet, be known. 4. Aspect and Exposure, and Spiecial Local Conditions. — These circum- stances chiefly affect a place by allowing free exposure to, or sheltering from the sun's rays, therefore lessening the number of hours the rays reach the soil, or by furnishing at certain times a large moist surface. Thus the extensive sandbanks of the Mersey cause very rapid alterations of temper- ature in the water and air, by being exposed every twenty-four hours twice to the sun and sky (Adie). 5. Atrial and Ocean Currents. — These have a great effect, bringing clouds which block out the sun or produce rain, or which, in the case of ocean currents, cool or warm the air. The cold polar sea currents and the warm equatorial (like the Gulf Stream) in some cases almost determine, and always greatly influence, the temperature of a place. 6. Nature of the Soil. — On this point little is yet known, but it is certain that some soils easily absorb heat ; others do not. The moist and clayey soils are cold ; the dry hard rocks and dry sands are hot. The hottest places on the earth are — in the eastern hemisphere, near the Red Sea, at Massava and Khartoum (15° N. L.), and on the Nile, in Lower Nubia ; annual temperature = 90.5° Fahr. ; in the western hemisphere, on the Continent, near the West Indies, the annual temperature is 81.5°. These are sometimes called the climatic poles of heat. The poles of cold are in Sibei'ia (Jakovitsk to Usjausk, 62° N.), and near Melville Island. Isothermal Lines. — These are lines drawn on charts, and were jjroposed by Humboldt to connect all places having the same mean annual temper- ature. The various conditions just noted cause these lines to deviate more or less from the lines of latitude. The lines of mean summer temperature (three months, June, July, August) are sometimes called isotheral ; those of mean winter tempei^attu'e (December, January, and February) isocheinional, or isocheimal, but these terms are now seldom used, the terms summer, winter, or monthly isother- mal, being substituted.' ' It may be well to mention the relations between the three principal thermometer scales. Whilst the freezing-point in the Fahrenheit scale is at 83', it is at 0° in both the Centigrade (or Celsius) and the Reaumur scales. Water boils at 212'' on the Fahrenheit scale (barometer = 29.905), at 100" on the Centigrade, and at 80° of Reaumur. Hence the formula of reduction is : — F-32 C R 9 ~ 5 ~ 4' from which the corresponding temperatures can easily be found. DESCRIPTION OF METEOROLOGICAL IJ^STRUMENTS. 103 SECTION IL HYGROMETERS— HUMIDITY OF THE AIR. The amount of watery vapor in the air can be determined in several vrays ; by dii-ect vreighing, by Daniell's, Regnault's or Dines' hygrometer, by the hair hygrometers of Saussure and Wolpert, and by the dry and v^et bulbs. ' The method by the dry and wet bulb thermometers has been adopted by the Army Medical Department, and observations are taken twice daily (9 a.m. and 3 p.m.). The instruments are not self-registering, and are simply read off. They are jjlaced in the shade, four feet above the ground, the bulbs freely exposed to the air, but not exposed to the effect of radiant heat from brick walls, etc. Tlie wet bulb is covered with muslin, which is kept moistened by cotton twisted round the bulb and then passing into the water -vessel ; previous to use, the cotton is soaked in solution of car- bonate of soda, or boiled in ether to free it from fat, so that water may ascend easily in it by capillary attraction ; the muslin and cotton should be renewed frequently, once or twice a month if possible ; the water must be either rain or distilled water, and the supply ought to be more ample in dry hot weather than in damp. When the temperature is below the freezing-point, the passage of water along the cotton is arrested ; it is then necessary to moisten the wet bulb some time before the hour of observa- tion so as to allow the moisture to freeze. The dew-point, the weight of a cubic foot of vapor, and the relative humidity, are to be computed from Mr. Glaisher's tables.^ Definition of these Terms. — The dew-point is the temperature when the air is just saturated with moisture, so that the least cooling would cause a deposit of water. The quantity of vapor which can be taken up and be made quite invisible to the senses varies with temperature, and is called the loeight of a cubic foot of vapor, or, less accurately, the weight of vapor in a cubic foot of air, at the particular temperature. The dew-point may be obtained directly by Daniell's or Regnault's or Dines' hygrometer, which enable us to cool and note the temperature of a bright surface until the dew is deposited on it, or indirectly by means of the dry and wet bulbs. Unless the air is saturated, the temperature of the wet bulb [i.e., the temperature of evaporation) is always above the dew-point, but is below the temperature of the dry bulb, being reduced by the evaporation. If the dry and wet bulbs are of the same temperature, the air is saturated with moisture, and the temperature noted is the dew-point ; if they are not of the same temperature, the dew-point is at some distance below the wet bulb temperature.^ It can then be calculated out in two ways, (a) By Mr. Glaisher's factors. — By comparison of the result of DanieU's hygrometer and the dry and wet bulb thermometers for a long term of years, Mr. Glaisher has deduced an empirical formula, which is thus ' These last are to be considered as one instrument, and are frequently called the Psychrometer of August, or (in this country) of Mason. '^ Hygrometrical Tables, 6th edition, 1877. A copy is now sent to each station. ^ Occasionally the wet bulb may read higher than the dry, as in thick fog or during very calm, cold weather. This is rare, but, should it be met with, then the tempera- ture of the dry bulb is to be taken and considered to be at saturation (Scott). 104 PRACTICAL HYGIENE. worked. Take the difference of the drv* and wet bulb, and multiply it by the factor which stands opj^osite the dry bulb temperature in the folJowin"- table, deduct the product from the dry bulb temperature, the result is the dew-point. From this formula Glaisher's tables are calculated. Glaishers Factors. Beadin? ol I)ry-bulb Tnenn. Edttbt. fit Dry-bulb Theiin. Factor. Reading Of Dry.-bulB THenn. Factor.' . neaOlnf,, otDrj-ljai) Therm. Factor. 10 8-78 6 33 3-01 5% 1-94 ,% 1-69 11 8-78 34 2-77 57 1-92 80 1-68 12 8-78 35 2-60 58 1 90 81 1-68 13 8-77 36 2 50 59 1-89 82 1-67 U 8-76 37 2 '42 60 1-88 83 1-67 15 8-75 38 2-36 61 187 84 1-66 16 8-70 39 2-32 62 1-86 85 1-65 17 8-62 40 2-29 63 1-85 86 1-65 18 8-50 41 226 64 1-83 87 1-G4 19 8-34 42 2-23 65 1-82 88 1-64 20 8-14 43 2-20 66 1-81 89 1-63 21 7-88 44 2-lS 67 1-80 90 1-63 22 7-60 45 2-16 68 179 91 1-62 23 7-28 46 2-14 69 1-78 92 1-62 24 6-92 47 212 70 1-77 93 1-61 25 6-53 43 2-10 71 1-76 94 1-60 26 6-08 49 2-03 72 1-75 95 1-6Q 27 5 61 50 2 '06 73 1-74 96 1-59 28 5-12 51 2-04 74 1-73 97 1-59 29 4-63 52 2 02 75 1-72 98 1-58 SO 4 15 53 2-00 76 1-71 99 1-58 31 3-60 54 1-9S 77 1-70 ioo 3-57 32 3-32 55 1-96 78 1-69 » (b) Apjohn's Formula. — From a most philosophical and exhaustive ana- lysis of the conditions of this complicated problem. Dr. Apjohn has derived his celebrated formula, which is now in general use. Reduced to its most simple expression, it is thus worked : — A table of the elastic tension of vapor, in inches of mercuiy at different temperatures, must be used. From this table take out the elastic tension of the temperature of the wet thermometer, and call it/'. Let (/-/') be the difference of the two ther- mometers, and p the observed height of the barometer. Apjohn's fonnida then enables us to calculate the elastic tension of the dew-point, which we wlU call/ " ; and this being known by looking in the table, we obtain, op- posite this elastic tension, the dew-point temperature. The formula is : /"=f-o.oiu7{f-r)-^ ity: the formula then becomes, for the temperature above 32° Fahr. : 7 • (t-f) p-f The fraction ^-y- differs but little from unity, and may be neglected ; If below 32° the formula is : /" =/' - 96 DESCRIPTIOi^ OF METEOROLOGICAL INSTRUMENTS. 105 The dew-point being known, the iceight of a cubic foot of vapor, and the amount of elastic tension, expressed in inches of mercuiy (if this is desired), are taken from tables ; the relative humidity is got by calcula- tion. The relative humidity is merely a convenient term to express compara- tive dryness or moisture. Complete satiu'ation being assumed to be 100, any degree of dryness may be expressed as a percentage of this, and is ob- tained at once by dividing the weight of vapor actually existing by the weight of vapor which would have been present had the air been satu- rated. In order to save trouble, all these points, and other matters of interest, such as the weight- of a cubic foot of dry air, or of mixed dry and moist air, are given in Mr. Grlaisher's " HygTometrical Tables," which aU medical officers are advised to get The amount of watery vajoor can also be told by a hair hygrometer. A modification of Saussure's hygrometer is still used in France, and also in Russia and Norway. A human hair, freed from fat by digestion in liquor potasses or ether, is stretched between a fixed point and a small needle, which traverses a scale divided into 100 parts. As the hair shortens or elongates the needle moves and indicates the relative humidity.' The scale is graduated by wetting the hair for complete saturation, and by placing it over sulphuric acid of known strength for fifteen degi'ees of saturation." A very delicate instrument is thus obtained, which indicates even momentaiy changes in moisture. On comparison with the wet and dry bulb, it has been found to give accordant results for three or four months ; it then gradually stretches, and requires to be a Uttle wound up. If compared with the dry and wet bulb, the hair hygrometer seems to be exact enough for experiments in ventilation, for which it is adapted from its rapidity of indication. It has also been recommended by the Vienna congress for use in extreme climates, when the indications of the psychro- meter are either uncertain or entirely astray.^ The horse-hau' hygrometer of Wolpert is also much used in Germany. The amount of watery vapor in the air has a considerable effect on the temperature of a place. Hermann von Schlagintweit * has pointed out that the differences between the temperature marked in the sun and shade by two maximum thermometers are chiefly dependent on the amount of hu- midity. The maxima of insolation (measured by the difference between the sun and shade thermometers) occur in those stations and on those days when humidity is greatest. Thus, at Calcutta, the relative humidity being 80 to 93, the insolation (or difference between the thermometers) is 50° Fahr. ; at BeUary the relative humidity being 60 to 65, the insolation is 8° to 11°. These results are explained hj Tyndall's observations, which show that the transparent humidity will scarcely affect the sun's rays strik- ing on the sun thermometer, while it greatly obstructs the radiation of in- visible heat from the thermometer ; when the air is highly charged with moisture, the sun thermometer is constantly gaining heat from the sun's rays, while it loses little by radiation, or if it does lose by radiation, gains it again from the air. When watery vapor mixes with diy air, the volume of the latter is aug- ' Hair shortens when dry, and elongates when moist. ^ The gradiiatlon of the scale is explained in The Arctic Manual, p. 16. * See Scott's Instructions, p. 47. * Proceedings of the Royal Society, vol. xiv. , p. Ill, 1865. 106 PRACTICAL HYGIENE. mented ; the weight of a cubic foot of diy air at 60° Fahr. is 536.28 grains, and that of a cubic foot of vapor at 60° is 5.77 grains ; the conjoint weights would be 542,05 grains at 60°, but, owing to the enlargement of the ah', the actual weight of a cubic foot of saturated air at 60° is only 532.84 grains. SECTION m. BAROMETER. A good mercurial barometer is supplied *to many army stations ; the scale is brass, graduated on the scale to 20ths or half-tenths, and is read to y-Q^y-gths by means of a vernier. There is a movable bottom to the cis- tern, which is worked up and down by a screw, so as to keep the mer- cury in the cistern at the same level. Connection for capacity is thus avoided. To fix the Barometer. — Choose a place with a good light, yet protected from du'ect sunlight and rain ; fix the frame sent with the barometer veiy carefully with a plumb-line, so as to have it exactly peiiDcndicular ; then hang the barometer on the hook, and adjust it gently by means of the three screws at the bottom, so that it hangs truly in the centre. Test this by the plumb-line (a 4 oz. weight tied to a string will do), and then un- screw the bottom of the cistern till the ivory point is seen, • Before fixing the barometer the bottom should be unscrewed till the mercury is two or three inches from the top ; the barometer should be rather suddenly inclined, so as to let the mercury strike against the top ; if there is no air it will do this with a sharp click ; if there be air there is no cHck ; in that case turn the barometer upside down, and tap the side forcibly till you see the globule of air passing up the tube through the mercurj' into the cistern. Do not be afraid of doing this ; there is no danger of any damage to the instrument. Reading of Barometer. — Read the attached thermometer first ; then ad- just the cistern, so that the ivory point, perceptible through the glass wall of the cistern, seems just to touch the point of the image in the mercury. Then adjust the vernier, so as to cut off the Hght from the top of the mer- cury'. Then read the scale with the help of the vernier, A little difficulty is sometimes experienced, by those who are not ac- customed to such instruments, in understanding the vernier. It will be, probably, comprehended from a little descriiDtion, read with the instru- ment before us. On the scale of the barometer itself, it will be seen that the smallest divisions correspond to half-tenths ; that is, to yl ^ths of an inch (=.05). The height of the mercury can be read thus far on the scale itself. The vernier is intended to enable us to read the amount of space the top of the mercury is above or below one of these half-tenth lines. It win be observed that the vernier is divided into twenty-five lines ; but on adjusting it, so that its lower line coiTesponds with a line indicating an inch, it will be seen that its twenty-five divisions only equal twenty-four half-tenth divisions on the scale. The result is, that each division on the vernier is jVth less than a half-tenth division on the scale. One ^^^th of a half-tenth is y^j^ths of an inch (.05-^25 = . 002 inch). This being under- stood, adjust the vernier so that its loicest line acciu'ately corresponds to any line on the scale. It wiU then be seen that its lowest line but one is a little distance below (in fact, ,002 inch) the next line on the fixed scale. DESCRIPTIOlSr OF METEOEOLOGICAL LNSTRUMENTS. 107 Kaise now the vernier, so that its second line shall corresiDond to the line on the scale to which it was a httle below ; and of course the bottom of the vernier must be raised .002 inch above the line it fii'st corresponded with. If the next line, the third on the vernier, be made to coiTespond with the line on the scale just above it, the bottom of the scale must be raised double this (.004 inch) above the line it was first level with ; if the next line on the vernier be made to correspond with a Hne on the scale, the scale is raised .006, and so on. Each division on the vernier equals .002 inch, and each five divisions equals yi^^th, or .01 inch. The barometer is read thus. The vernier being adjusted to the top of the mercury, read on the scale to the half-tenth ; then look above, and see what line on the vernier corresponds exactly to a line on the scale. Then read the number on the vernier, counting from the bottom ; multiply by .002, and the result is the number of thousaudths of an inch the top of the mercury is above the half-tenth hne next below it.' Add this number to that ah'eady got by direct reading of the fixed scale, and the result is the height of the mercury in inches and decimals of an inch. Corrections for the Barometer. — The barometer sujDpHed to military stations requu-es no coiTections for capacity. There are two constant coiTections for all barometers, viz., capillarity and index error. The first depends on the size of the bore, and whether the mercury has been boiled in the tube or not. Index error is determined by compailson with a standard barometer. The index and capillarity eiTors are put together. The capiRarity error is always additive ; the index error may be subtrac- tive or additive, but the two together form a constant c^uantity, and the certificates furnished by the Kew Observatory, for all bai'ometers verified there, include both corrections above mentioned. Corrections for Temperature. — The barometer readings are, to facihtate compai'ison, always reduced to what they would have been were both scale and mercm-y at 32° F. If the temperature of the mercury be above this, the metal exjDands, and reads higher than it would do at 32''. The amount of expansion of mercury is .0001001 of its bulk for each degi'ee ; but the linear expansion of the brass scale must be also considered. Schumacher's formula is used for the correction — \\z., h = observed height of barometer in inches. t = temperatiu'e of attached thermometer (Fahr.). m = expansion of mercury per degree — viz., .0001001 of its length at 32°. s = linear expansion of scale — viz., .00001041 ; normal temperature being 62°. m (^-32°)-g (^-62°) "^ . 1 + m {t-32°) ■ To facilitate the correction for temperature, tables are given in Mr. R. . ' Instead of multiplying the number on the vernier by . 003, a little practice will enable the calculation to be made at once. On the vernier will be seen the figures 1, 2, 3, 4, and 5 ; corresponding to the 5th, 10th, loth, 20th, and 25th lines, and indicating .01, .02, .03, .04, or .05 inch. Each line between these numbered lines equals .002 inch. 108 PKACTICAL HYGIENE. H. Scott's " Instructions iu the Use of Meteorological Instmments," which is distributed to medical officers. Correction for Altitude above Sea-level. — As the mercury falls about ToW (-001 inch)' for every foot of ascent, this amount multiplied by the number of feet must be added to the height, if the place be above sea-level.^ The temperature of the air has, however, also to be taken into account if great accuracy is required. Tables for correcting for smaU altitudes are given in Scott's "Instructions." When all these coiTections have been made, the exact height of the mercury repi'esents the conjoint weights of the oxygen, nitrogen, carbon dioxide, and watery vapor of the atmosphere. It is difficult to separate these several weights, and late observations, which show that the humidity existing at any place is merely local, and that vapor is most unequally dif- fused through the air, render it quite uncertain what amount of the mer- cury is supported by the watery vapor. Yet that this has a considerable effect in altering the barometric height, particularly in the tropics, seems certain (Herschel). The height of the barometer at sea-level differs at different parts of the earth's surface ; being less at the equator (29.974) than on either side of 30° N. and S. lat., and lessening again toward the poles, especially toward the south, fi'om 63° to 74° S. lat., where the depression is upward of an inch. It also differs in different places according to their geographical position. Like the thermometer, it is subjected to diumal and annual periodic changes and to non-periodic undulations. In the tropics the diui*nal changes are very steady ; there are two maxima and two minima ; the first maximum is about 9 a.m. ; the fii'st minimum about 3 to 4 p.m.; the second maximum at 10 p.m.; the second minimum at 4 a.m. These changes are, perhaps, chiefly dependent on the watery vapor (Herschel). In this country the diurnal range is less, but occurs at about the same hours. The undulations depend on the con- stantly shifting currents of air, rendering the total amount of air over a place heavier or lighter. The wind tends to pass toward the locality of least barometric pressure. In this country the barometer falls with the southwest winds ; rises wdth the north and east ; the former are moist and warm, the latter dry and cold winds. Isobarometric lines are lines connecting places with the same baro- metric pressure. Measurement of Heights. — The barometer falls when heights are as- cended, as a certain weight of air is left below it. The diminution is not uniform, for the higher the ascent the less weighty the air, and a gi-eater and greater height must be ascended to depress the barometer one inch. This is illustrated by the following table : ^ ^ The exact amount is a little below this, but varies with altitude ; at sea-level the amount is .000886 for every foot of ascent. ■^ For the British Isles, the mean sea-level at Liverpool has been selected by the Ordnance Survey as their datum. ^ The height can be taken readily from this table, by calculating the number of feet which must have been ascended to cause the observed fall, and then making a correc- tion for temperature, by multiplying the number obtained from the table, which may be called A, by the formula {t is the temperature of the lower, and t' of the upper station) — /, t + t'-QA\ . DESCRIPTION OF METEOEOLOGICAL IXSTKUMENTS. 109 To lower from 31 inch es to 30 = 857 < 30 29 = 886 < 29 28 = 918 ( 28 27 = 951 ( 27 ' 26 = 986 c< 26 25 = 1,025 e 25 24 = 1,068 c 24 23 = 1,113 e 23 22 = 1,161 t 22 21 = 1,216 :c 21 20 = 1,276 e 20 19 = 1,341 C( 19 18 = 1,413 857 feet must be ascended. The measurements of heights in this way is of great use to medical oflQ-cers ; aneroid barometers can be used, and are very delicate instru- ments. The new pocket aneroids wiU measure up to 12,000 or 14,000 feet. A great number of methods are in use for calculating heights. It can be done readily by logarithms, but then a medical officer may not possess a table of logarithms. The simplest rule of all is one derived from Laplace's formula. Mr. Ellis' has stated this formula as follows : — Multiply the difference of the barometric readings by 52,400, and divide by the sum of the barometric readmgs. If the result be 1,000, 2,000, 3,000, 4,000, or 5,000, add 0, 0, 2, 6, 14, respectively. Subtract 2^ times the difference of the temperatures of the mercury. Multiply the remainder by a number obtained by adding 836 to the sum of the temperatures of the air, and dividing by 900. A correction must also be made for latitude, which can be done by Table m., p. 111. Tables such as those given by Delcros and Oltmanns are very con- venient for estimating heights by the barometer. A table less long than these, but based on the same principle, has been given by Negretti & Zambra in their useful work,^ and is copied here. A good mercurial barometer, with an attached thermometer, or an aneroid compensated for temperature, and a thermometer to ascertain the temperature of the air, are required. Two barometers and two thermo- meters, which can be observed at the same moment at the upper and lower stations, are desirable. Supposing, however, there is but one barometer, take the height at the lower station, and correct for temperature to 32°. Take the temperature of the air. Ascend as rapidly as possible to the upper station, and take the height of the barometer (correcting it to 32°) and the temperature of the air ; then use the accompanying tables,' taken from Negretti & Zam- bra's work. If the height is less than 300 feet, Tables 11., III., and IV. need not be used. "Table I. is calculated irom the formula, height in feet ==60,200 (log. 29.922 — log. 5) + 925 ; where 29.922 is the mean atmospheric pressure at 32° Fahr., and at the mean sea-level in latitude 45°; and B is any other barometric pressure ; the 925 being added to avoid minus signs in the table. ' Proceedings of the Royal Society, 1865, No. 75, p. 283. - A Treatise on Meteorological Instruments, by Negretti & Zambra, 1864. no PRACTICAL nYGIENE. Table I. — Approximate Height due to Barometric Pressure. Inches of Feet. Inches of Feet. Inches of G>Ani Barometer. Barometer. Barometer. reel. 31-0 27-3 3.323 23-6 7,131 SO -9 84 •2 3,419 •5 7,242 •8 169 •1 3,515 •4 7,353 •7 254 27-0 3,612 •3 7,465 •6 339 26-9 3,709 •2 7,577 •5 425 •8 3,806 •1 7,690 •4 511 •7 3,904 23-0 7,803 •3 697 •6 4,002 22-9 7,917 '2 683 •5 4,100 •8 8,032 •1 770 '4 4,199 •7 8,147 30-0 857 •3 4,298 •6 8,262 29-9 944 •2 4,398 •5 8,378 •8 1,032 •1 4,498 •4 8,495 -7 1,120 26-0 4.588 •3 8,612 •■6 1,208 25-9 4,699 •2 8,729 •6 1,296 •8 4,800 •1 8.847 •4 1,385 •7 4,902 22-0 9,966 •3 1,474 •6 6,004 21-9 9,085 •2 1,563 •5 6,106 •8 9,205 •1 1,653 •4 5,209 •7 9,325 29-0 1,743 •3 5;312 •6 9,446 28-9 1,833 •2 5,415 •5 9,567 •8 1,924 •1 6; 51 9 •4 9,689 •7 2,015 25-0 6j623 •3 9,811 •6 2,016 24-9 5,728 ♦2 9,934 •5 2,198 •8 6,833 •1 10,058 •4 2,290 •7 5,939 21-0 10,182 '3 2,382 •6 6,045 20-9 . 10,307 •2 2,475 •5 6,152 •8 10,432 ■1 2,568 •4 6,259 •7 10,558 28-0 2,661 •3 6,366 •6 10,684 27-9 2,754 •2 6,474 •5 10,812 •8 2,848 •I 6,582 •4 10,940 '7 2,942 24-0 9,691 '3 11,069 •6 3,037 23-9 6,800 •o Hi 198 ■5 3,132 •8 6,910 •1 lli328 27-4 3,227 237 7,020 20-0 li;458 " Table IL contains the correction necessary for the mean temperature of the sti-atum of air between the stations of observation ; and is computed from Regnault's co-efficient for the expansion of air, which is .002036 of its volume at 32° for each degree above that tempei-ature. " Table III. is the coiTCction due to the difference of gravitation in any other latitude, and is found from the formula, .r = 1 + .00265 cos. 2 lat. " Table IV. is to correct for the diminution of gravity in ascending from the sea-level. " To use these tables : The barometer readings at the upper and lower stations having been corrected and reduced to temperature 32° Fahr., take out from Table I. the numbers opposite the corrected readings of the two barometers, and subtract the lower from the upper. Multiply this difference successively b}'' the factors found in Tables 11. and HI. The factor from Table III. may be neglected unless great precision is de- sired. Finally, add the correction taken from Table IV." (Negretti & Zambra. ) In the table the barometer is only read to lOths, but it should be read DESCRIPTION OF METEOROLOGICAL INSTRUMENTS. Ill to lOOths (.01) and l,000ths (.001), and the number of feet corresponding to these amounts calculated from the table, which is easy enough. Table U. — Correction due to Mean Temperatures of the Air ; the Tempera- ture of the Upper and Lower Stations being added and divided by 2. Mean Temp. Factor. Mean Temp. Factor. Mean Temp. Factor. . 10' 0-955 35= 1-006 60° 1-057 11 •957 36 1-008 61 1-059 12 •959 37 1-010 62 1-061 • 13 •961 38 1-012 63 1-063 14 '■J63 39 1'014 64 1-065 16 •963 40 1-016 65 1-067 16 •967 41 1-018 66 1-069 17 -969 42 1-020 67 1-071 18 •971 43 1-022 68 1-073 19 '974 44 1-024 69 1-075 20 •976 45 1-026 70 1-077 21 '978 46 1-029 71 1-079 22 •980 47 1-031 72 1-081 23 ^982 48 1-033 73 1-083 24 •984 49 1-035 74 l-08f5 25 •986 50 l-0'37 75 1-088 26 •988 51 1-039 76 1-090 27 •990 52 1-041 77 1-092 28 •992 53 1-043 78 1-094 29 •994 54 1-045 79 1-09Q SO -996 55 1-047 80 1-098 SI 0-998 53 1-049 81 1-100 32 1-000 57 1051 82 1-102 S3 1-002 58 1-053 83 1-104 Si 1-004 59 1-055 84 1-106 Table HL — Correction due to Difference of Gravitation in different Latitudes. Latitude. Factor. Latitude. Factor, Latitude. Factor. 80' 0-99751 50' 0-99954 20° 1-00203 75 0-99770 .45 1-00000 15 1-00230 70 99797 40 1-00046 10 1-00249 65 0-99'830 35 1 -000.90 5 1-00261 60 0-99868 30 1 '00132 1-00265 55 99910 25 1-00170 Table IV. f Height in Ccn-ection Height in Gorrectiott . Tliousand Feet. Additive. Thousand Feet. Additive. 1 3 9 26 2 5 10 30 3 S 11 33 4, 11 12 37 5 14 13 41 6 17 14 44 7 20 35 48 8 23 112 PRACTICAL HYGIENE. Example. — At two stations the barometer read respectively 29.9 and 21.2, the temperatures of the air being 60° and 40°. Barometer at upper station 21.2, Table 1 9,934 " lower " 29.9, " 944 Approximate mean height 8,990 Mean temperature 50°, Table 11., Factor 1.037 Height corrected for temperature 9,323 Latitude (say) 30°, Table in.. Factor 1.00132 Height corrected for latitude 9,335 Correction from Table IV 26 Height coiTected for direct altitude 9,361 Height of lower station above sea-level (say) 150 Final con-ected height of upper station above sea-level. 9,511 A very simple nile for approximative determinations has been given by Mr. R. Strahan. ' Read the aneroid to the nearest hundredth of an inch ; subtract the upper reading from the lower, leaving oxit or neglecting the decimal point ; multiply the difierence by 9 ; the product is the elevation in feet. Example. inches. Lower station 30.25 Upper " 29.02 123 9 Elevation l,170feet. If the barometer at the upper station is below 26 inches, or the tempera- ture above 70°, the multiplier should be 10. Weight of the Air. — The barometer expresses the weight of the air in inches of mercury. The actual weight can be determined if the reading of the barometer, temperature, and humidity are all known. The weight of a cubic foot of dry air, at 32° Fahr. and normal pres- sure, is 566.85 grains. For any other temjoerature the weight can be calcu- lated. Multiply the coefficient of the exi)ansion of air (viz., .0020361 for 1° Fahr.) by the number of degrees above 32, the sum added to unity wiU give the volume of a cubic foot of dry air at that temperature. Divide 566.85 by the number so obtained. The result is the weight of the dry air at the given temperature. SECTION IV. RAIN, Rain is estimated in inches ; that is, the fall of an inch of rain implies that on any given area, say a square yard of surface, rain has fallen equal to one inch in depth. The amount of rain is determined by a rain-gauge. ' Pocket Altitude Tables, by G. J. Symoiis, F.R.S., 3d ed., 1880, p. 5. DESCRIPTION OF METEOROLOG-ICAL IXSTRUMEXT3. 113 Two gauges ai-e supiDlied for military stations ; one to be placed on the ground, one 20 feet above it ; in all parts of the world the latter indicates less rain than the lower placed gauge ; this is due to wind.' Several kinds of gauges are in use. The one used by the Army Medical Department is a cyhndiical tin box with a rim or groove at the top ; a circular top with a funnel inside fits on to this groove, which, when tilled with water, forms a water-valve. The opening above is circulai* (the circle being made very carefully, and a rim being cai-ried round it to j^revent the rain-drops from being whuied by wind out of the mouth), and descends funnel-shaped, the small end of the funnel being turned up to prevent evaporation. But leaves, dust, or insects sometimes choke this tube, so that it is now generally straightened, the loss by evaporation being insignificant, compared with that caused by obstruction. The best size for the open top, or, in other words, the area of the receiving surface, is from 50 to 100 square inches. The lower part of the box is sunk in the ground nearly to the groove ; the upper pai't is then put on, and a glass vessel is placed below the funnel to receive the water.' At stated times (usually at 9 a.m. daily) the top is taken off, the glass vessel taken out, and the water measui'ed in a glass vessel, gTaduated to hundredths of an inch, which is sent with the gauge.' If snow falls instead of rain, it must be melted and the resulting water measui'ed. This may be easily done by adding a measured cpantity of warm water, and then subtracting the amount from the total bulk of water. From a table of the weight of vapor it will be seen that the amount of vapor which can be rendered insensible, increases with the temperatru^e, but not regularly ; more, comparatively, is taken up by the high tempera- tures ; thus, at 40^, 2.86 grains are supported ; at 50', 4.10 gi'ains, or 1.24 grain more ; at 60^, 5.77 grains, or 1.67 grain more than at 50". There- fore, if two currents of air of unequal temperatures, but equally saturated with moisture, meet in equal volume, the temjDerature ■v\ill be the mean of the two, but the amount of vapor which wiU be kept invisible is less than 1 See Britisli Rainfall (G. J. Symons, F.R.S.), 1872, p. 33, and 1881, p. 41. - A glass vessel should not be used in winter, for fear of breakage in frost. " If tbis glass is broken it can be replaced by tbe following rule, or a rain-gauge can be made. It need not be round, tliougb tbis is now thought the best form, but may be a square box of metal or wood, and may be of any size between 3 and 2-i inches in dia- meter, but 5 to 8 is the most couyenient range. Determine the area, in square inches, of the receiving surface, or top of the gauge, by careful measurement. This area, if covered with wafer to the height of one inch, would give us a corresponding amount of cubic inches. This number of cubic inches is the measure for that gauge of one inch, because when the rain equals that quantity it shows that one inch of rain has fallen over the whole surface. Let us say the area of the receiving surface is 100 square inches. Take 100 cubic inches of water and put it into a glass, put a mark at the height of the fluid, and divide the glass below it into 100 equal parts. If the rainfall comes up to the mark, one inch of rain has fallen on each square inch of surface ; if it only comes up to a mark below, some amount less than an inch (which is so expressed in -piths and jj^T;ths) has fallen. To get the requisite number of cubic inches of water we can weigh or measure. A cubic inch of water at 62'^ weighs 252.458 grains, consequently 100 cubic inches will be (252.458 X 100) =25245.8 grains, or 57.7 ounces avoir. But an earner way still is to measure the water, — an ounce avoir, is equal to 1.738 ciibic inches, therefore divide 100 by 1.733, and we obtain the number of ounces avoir, which corresponds to 100 cubic inches. It is always best, however, to use a gauge made by a regular maker, if possible, as inaccurate records are worse than none. Usually a one-inch measure is so large a glass, that half an inch, is considered more convenient. YoL. n.— 8 114 PRACTICAL HYGIENE. tlie mean, aiid some va,por therefore necessarily falls as fog or rain. Thus one saturated current being at 40^, and the other at 6i)^, the resultant temperature will be 50"^, but the amount of invisible vapor 'nill not be the mean, \dz., 4.315, but 4.1 ; an amount equal to .215 will therefore be de- posited. Rain is therefore o\\ang to the cooling of a sat\u*ated air, and rain is heaviest under the following conditions, — when, the temperature being high, and the amount of vapor large, the hot and moist air soon encounters a cold air. These conditions are chiefly met with in the tropics, when the hot air, saturated with vapor, impinges on a chain of lofty hills over which the ail' is cold. The fall may be 130 to 160 inches, as on the Malabar coast of India, or 180 to 220 in Southern Bui-mah, or 600 at Cherrapoonjee, in the Khasyah Hills. Even in our own country the hot air from the Gulf Stream impinging on the Cumberland Hills causes, in some districts, a fall of 80, 100, 200, and even more inches in the year. The rainfall in different places is remarkably irregular from year to year ; thus at Bombay the mean being 76, in 1822 no less than 112 inches, while in 1824 only 34 inches fell. The amount of rain at the different foreign stations is given under the respective headings. SECTION V. EVAPORATION. The amount of evaporation from a given moist surface is a problem of gi'eat interest, but it is not easy to detennine it exjjerimentally, and no in- strument is issued by the Army Medical Department. A shallow vessel of known area, protected around the rim by wire to prevent birds from drink- ing, is filled with a known quantity of water, and then, weekly or monthly, the diminution of the water is determined, the amount added by rain as shown by the rain-gauge being of course allowed for. Water has been placed under a cover, which may protect it from rain and dew, and yet permit evaporation, and the loss weighed daily ; but it is impossible to insure that the evaporation shall be equal to that under the free heavens. A third plan is calculatiug the rate of evaporation from the depression of the wet bulb thermometer, by deducting the elastic force of vapor at the dew-point temperature from the elastic force at the air temperature, and taking the diflerence as expressing the evaporation. This difference expresses the force of escape of vapor from the moist surface. Instruments termed ^/??io»fe^ers have been used for tliis purpose; the fii'st was invented by Leslie. A ball of porous earthenware was fixed to a glass tube, with di\isions, each corresponding to an amount of water which would cover the siu-face of the ball with a fihn equal to the thickness of YjL^th part of an inch. The evaporation from the surface of the ball was then read off. Dr. Babington has also invented an ingenious Atmi- dometer. ' The amount of evaporation is influenced by temperature, wind, hu- midity of the air, rarefaction of the air, degree of exposin-e or shading, and by the nature of the moist surface ; it is greater fi-om moist soil than from water. ' See Negretti & Zambra's Treatise, p. 141, for details. DESCRIPTION OF METEOROLOGICAL INSTRUMENTS. 115 The amount of vapor annually rising from each square inch of water surface in this country has been estimated at from 20 to 24 inches ; in the tropical seas it has been estimated at from 80 to 130, or even more inches, Tn the Indian Ocean it has been estimated at as much as an inch in twenty- four hours, or 365 in the year, an almost incredible amount. No doubt, however, the quantity is very great. It requires an effort of imagination to realize the immense distillation which goes on from the tropical seas. Take merely 60 inches as the an- nual distillation, and reckon this in feet instead of inches, and then pro- ceed to calculate the weight of the water rising annually from such a small space as the Bay of Bengal. The amount is almost incredible. This distillation of water serves many great purposes ; mixing with the air it is a vast motive power, for its specific gravity is very low (.6230, air being 1), and it causes an enlargement of the volume of air ; the moist air is therefore much lighter, and ascends with great rapidity ; the distillation also causes an immense transference of heat from the tropics, where the evaporation renders latent a great amount of heat, to the extra-tropical region where this vapor falls as rain, and consequently parts with its latent heat. The evaporation also has been supposed to be a great cause of the ocean currents (Maury), which play so important a part in the distribution of winds, moisture, and warmth. SECTION VI. WIND. Direction. — For determining the direction of the wind a vane is neces- sary. It should be placed in such a position as to be able to feel the in- fluence of the wind on all sides, and not be subjected to eddies by the vicinity of buildings, trees, or hills. The points must be fixed by the com- pass ; ' the magnetic declination being taken into account ; the declination of the place must be obtained from the nearest observatory ; in this country it is now about 21° (or two points) to the westward of true north. ^ The direction of the wind is registered twice daily in the army returns, but any unsual shifting should receive a special note. The course of the wind is not always parallel with the earth ; it sometimes blows slightly down- ward ; contrivances have been employed to measure this, but the matter does not seem important. Various plans are resorted to for giving a complete summary of the winds, but this is not required from the medical officer. Velocity. — A small Robinson's anemometer is now supplied to each station ; it is read every twenty-four hours, and marks the horizontal movement in the preceding twenty-four hours. This anemometer consists of four small cups,' fixed on horizontal axes of such a length (1.12 foot between two cups), that the centre of a cup, in one revolution, passes over y^oQ-th of a mile, the circumference being 3.52 feet. These cups revolve with about a third of the wind's velocity ; 500 revolutions of the cups are therefore supposed to indicate one mile, and ' Or, better still, by the pole star. ^ Thus N. magnetic will be N.N.W. true, S. magnetic S.S.E. true, and so on. ° The current of air is opposed one-fourth more by a concave eunace than by a convex one the same size. 116 PRACTICAL HYGIENE. by an ai-rangement of wheels, the number of miles traversed by the wind can be approximately ascertained. Osier's anemometer is a large and veiy beautiful instrument. It reg- isters simultaneously on a piece of paper fitted on a drum, which is turned by clock-work, direction, velocity, and pressure. Other anemometers, Lind's, Whe well's, etc., need not be described. The average velocity of ■s\-ind in this country neai" the siu'face of the earth is from six to eight miles per hour ; its range is from zero to 60 or even 70 miles per hour, but this last is veiy rare ; it is seldom more, even in hea^y winds, than 35 to 45 miles per hour. In the hurricanes of the Indian and China seas it is said to reach 100 to 110 miles per hour. Force. — The force of the wind is reckoned as equal to so many pounds or parts of a pound on a square foot of surface. Osier's anemometer, as just stated, registers the force as weU as the velocity and direction, but Robinson's (used in the army) marks only the velocity ; the force must then be calculated. The rule for the calculation of the force from the ve- locity is as follows : — Ascertain the mean velocity per hour by observing the velocity for a minute, and multiplying by 60 ; then square the hoiuly velocity and mul- tiply by .005. The result is the pressure in pounds or parts of a pound per square foot. The formula is, if V = velocity per hour, Y'y .005 = P. If the force be given, the velocity may be found : V2WP~= V. "When no anemometer is in use, the Beaufort scale may be employed, = calm, about 3 miles an horn-, and 12 = hurricane, 90 miles and over. SECTION vn. CLOUDS (Plate IX.). The nomenclature proposed by Howard' is now almost universally adopted. There are three principal forms and four modifications. Principal Forms. Cirrus. — Thin filaments, which b\ association form a bmsh, or woolly hail*, or a slender network. They are very high in the atmosphere, i:)rob- ably more than ten miles, but the exact height is unknown. It has even been questioned whether they are composed of water ; if so, it must be frozen. In this climate they come from the northwest. Cumidus. — Hemisioherical or conical heaps like mountains rising fi'om a horizontal base ; cumuli are often compared to balls of cotton. Stratus. — A widely extended, continuous horizontal sheet, often forming at sunset. Modifications. Cirro-cuvndus. — Small rounded, well-defined masses, in close, horizontal arrangement ; when the sky is covered with such clouds it is said to be fleecy. ' Climate of London. DESCEIPjriOX OF METEOEOLOGICAL I]S"STEUMEXTS. 117 Cirro-stratus. — Horizontal strata or masses, more compact than the cini ; at the zenith they seem composed of a number of thin clouds ; at the horizon they look Kke a long naiTow band. Cumulo-stratus. — Stratus blended with the cumulus. Curaulo-drro-stratus, Ximbus, or Eain-doud. — A horizontal sheet above which the cirrus spreads, while the cumulus enters it laterally or from below. Of the above forms Nos. 1, 2, and 3 of the plate (copied by permission from ]\Ir. Scott's " Instructions ") are " upper " clouds ; the others are " lower " clouds. To those described is added the form shown in Xo. 5, viz., Eoll- cumulus, which consists of portions of cumulus rolled into a cyhndi-ical shape, and either separate or joached together, as shown in the plate. Alongside the names in the plates are contractions, which ought to be used in description. Estimation of Amount of Cloud. — This is done by a system of numbers : expresses a cloudless sky, 10 a perfectly clouded sky, the intermediate numbers various degrees of cloudiness. To get these numbers, look mid- way between the horizcai and zenith, and then turn slowly round, and judge as well as can be done of the relative amount of clear and clouded sky. This is to be entered without reference to the thickness of the cloud. SECTION \TII. OZOXE.i Papers covered with a composition of iodide of potassium and starch, and exposed to the air, are supposed to indicate the amount of ozone present in the atmosphere. Schonbein, the discoverer of ozone, originally j)repared such papers, and gave a scale by which the depth of blue tint was estimated. Subsequently similar but more sensitive papers were prej)ared by Dr. Moffat, and ]\Ir. Lowe afterward improved on Moffat's papers, and also prepared some ozone powders. The papers are exposed for a definite time to the air, if possible with the exclusion of light, and the alteration of color is compared with a scale. Schonbein's proj^ortions are — 1 part of pure iodide of potassium, 10 parts starch, and 200 parts of water. Lowe's proportion is 1 part of iodide to 5 of starch ; Moffat's proportion is 1 to 2^. The starch should be dis- solved in cold water, and filtered so that a clear solution is obtained ; the iodide is dissolved in another portion of water, and is gradually added. Both must be perfectly pure ; the best arrowroot should be used for starch. The paper, prepared by being cut into shps (so as to dry quicker and to avoid loss of the powder in cutting) and soaked in distilled water, is placed in the mixed iodide and starch for four or five hoiu's, then removed with a pail' of pincers, and slowly dried in a cool dark place, in a horizontal position. The last point is important, as otheinvise a large amount of the iodide drains down to one end of the paper, and it is not equally diffused. The papers when used should hang loose in a place protected from the sun and rain ; a box is unnecessaiw ; they should not be touched with the fingers more than can be helped when they are adjusted. e_ ' For a full account of the tests of ozone, see Dr. Fox's -n-ork on Ozone and Antozone, 1873, already referred to. After discussing all the tests, he gives the preference to the iodine plan. He has not found Schonbein's thallium method satisfactory. 118 PRACTICAL HYGIENE. When Schonbein's papers are used they are moistened with water after exposure, but before the tint is taken. Moffat's papers are prepared sorue- M'hat similarly to Schi'mbeiu's, but do not require moistening with water. The estimation of ozone is still in a veiy unsatisfactoiy state, and this aiises from two cuTumstances. 1. The fact that other substances besides ozone act on the iodide of potassium, especially nitrous acid, which is formed in some quantity dming electrical storms. Cloez has shown that air taken about one metre above the gi'oimd often contains nitrous acid in sufficient quantity to redden litmus. Starch and iodide paper is colored when air contains .00005 of its volume of nitrous acid. 2. The fact that the papers can scarcely be put under the same condi- tions from day to day ; light, wind, humidity, and temperatiire (by expel- ling the free iodine) all affect the reaction. Chemical objections have also been made.' Supposing that iodine is set free by ozone, a portion of it is at once changed by additional ozone into iodozone, which is extremely volatile at ordinary temj^eratures, and is also changed by contact with water into free iodine and iodic acid. Hence a portion of the iodine originally set free never acts on the starch, being either volatilized or oxidized. Again, the iodine and caustic potash set free by the ozone combine in part again, and form iodate and iodide of potassium f|th of the former and |ths of the latter), and in this way the blue color of iodide of starch first produced may be removed. The ozone may possibly, and probably, act on and oxidize the starch itself, and hence another error. The conclusion an'ived at by the Vienna congi-ess was the foUowing: " The existing methods of determining the amount of ozone in the atmos- phere are insufficient, and the congress therefore recommends investiga- tions for the discoveiy of better methods." SECTION IX. ELECTRICITY. The instruments used by meteorologists are simjDle electroscopes, with two gold-leaf pieces which diverge when excited, or diw galvanic piles act- ing on gold-leaf plates or an index attached to a Leyden jar (Thomson's electrometei-). For further details, see Scott's " Instinictions," op. cit. SECTION X. THERMOMETER STAN'D. A stand is issued by the War Office, and provided at every station. Or it would be very easy to make a stand by two or three strata of boards, placed about 6 inches apart, so as to form a kind of sloping roof over the thermometers, which are suspended on a vertical board. The diy and wet bulb thermometers ai'e placed in the centre ; the maximum on the right side, and the minimum on the left. The wood ' Beitrage zur Ozonometrie, von Dr. v, Maach ; Archiv fiir Wiss. Heilk., Band ii., p. 29. DESCRIPTIOlSr OP METEOROLOGICAL INSTRUMENTS. 119 should be cut away behind the bulbs of the maximum and minimum ther- mometers, so as to expose them freely to the au\ The bulbs of the dry and "wet bulbs should also fall below the board. These stands are made to rotate on the pole so as to turn the roof always to the sun. A much better stand is Stevenson's screen, a square or oblong box, with double louvred sides and open below. This is raised upon legs, four feet from the ground, placed upon grass. ' SECTION XI. WEATHER. In registering the kind of weather it is well to adhere to the Beaufort notation and symbols, which are carefully explained in Scotfs " Instruc- tions." Columns are given in the return to be filled up in this way. SECTION xn. DISEASES AND VARIATIONS IN THE METEOROLOGICAL ELEMENTS. The variation in the prevalence of different diseases at a particular place, in connection with the simultaneous variation of meteorological elements, is an old inquiry which has at present led to few results. The reason of this is that the meteorological elements are only a few out of a great many causes affecting the prevalence and severity of diseases. Con- sequently, in order to estimate the real value of changes of temperature, pressure, humidity, ozone, etc., the other causes of disease, or of varia- tions in prevalence or intensity, must be recognized and eliminated from the inquiry. The best of the late observations are those by Guy, Ran- some, Vernon, Moffat, Tripe, Scoresby-Jackson, and Ballard. Observa- tions have also been made by Fodor and others on the continent of Europe, and by various observers in America and elsewhere. But they must be much more extended and numerous before anything practical can be drawn from them. ' Scott's Instructions, Fig. 10, p. 41. CHAPTER XVL INDIVIDUAL HYGIENIC MANAGEMENT. This subject is an extremely large one, and the object of tliis book does not jDermit of its discussion. It would require a volume to itself. Only a few very general remarks can be made here. The aj)i3lication of general hygienic rules to a particular case constitutes individual management. It is impossible to make general rules sufficiently elastic, and yet pre- cise enough, to meet every jDossible case. It is sufficient if they contain principles and precepts which can be applied. While individual hygiene should be a matter of study to all of us, it is by no means desu-able to pa}' a constant or minute attention to one's own health. Such care will defeat its object. We should only exercise that reasonable care, thought, and prudence which, in a matter of such moment, every one is bound to take. Every man, for example, who considers the subject bond fide, is the best judge of the exact diet which suits him. If he understands the gen- eral principles of diet, and remembers the Hippocratic rule, that the amount of food and exercise must be balanced, and that evil results fi'om excess of either, he is hardly liliely to go wrong. " Temperance and exercise," was the old rule laid down, even before Hippocrates,' as containing the essence of health; and if we translate tem- perance by "sufficient food for wants, but not for luxuries," we shall ex- press the present doctrine. The nutrition of the bod}' is so affected by individual peculiarities, that there is a considerable variety in the kind of food taken by difi'erent j^er- sons. The old inile seems a good one, viz., while conforming to the gen- eral jDrinciples of diet, not to encourage too great an attention either to quantity or to quality, but avoiding what experience has shown to be mani- festly bad, either generally or for the particular individual, to allow a considerable variety and change in amount from day to day, according to appetite. ° Proper and slow mastication of the food is necessary ; and it is ' It is quite pLain from the context, that Hippocrates, by temperance, meant such an amount of food as would balance, and neither exceed nor fall short of the exercise. He had a clear conception of the development of mechanical force from, and its re- lation to, food. He lays down rules to show when the diet is in excess of exercise, or the exercise in excess of diet. In either case he traces disease. ' Celsus carried the plan of variety so far as to recommend that men should some- times eat and drink more than is proper, and should sometimes not exceed ; and Lord Bacon has a remark which leads one to believe he held a similar opinion ; but there can be no doubt of the incorrectness of this opinion. It has been truly said that the first general rule of Hippocrates, which prescribes continual moderation, is much truer, and the best writers on hygiene, ancient and modern, have decided against Celsus. Besides being erroneous, the rule of Celsus opens a door to intemperance, and, like a harmless sentence in Hii)pocrates, has been twisted to serve the argument of gour- mands. Its influence is felt even at the present day. This much is certain, that prob- INDIVIDUAL HYGIENIC MANAGEMENT. 121 extraordinary how many affections of the stomach called dyspepsia arise simply from faulty mastication, from deficient teeth, or from swallowing the food too rapidly. Many persons who are too thin are so from their own habits ; they eat chiefly meat, and eat it very fast ; they should eat slowly, and take more bread and starchy substances. Fat persons, on the other hand, by lessening the amount of starch, and taking more exercise, can lessen with the greatest ease the amount of fat to any amount. It must be remembered, however, that there is a certain individual con- formation in this respect ; some persons are normally fatter or thinner than others. The exact amount of exercise must also be a matter of individual de- cision, it being remembered that exercise in the free air is a paramount condition of health, and that the healthiest persons are those who have most of it. As a rule, persons take far too little exercise, especially educated women, who are not obliged to woi'k, and the muscles are too often flaccid and ill-nourished.' Attention to the skin is another matter of personal hygiene. The skin must be kept perfectly clean and well clothed. Some writers, indeed, have advised that, if food be plentiful, few clothes be worn ; but the best authors do not agree in this, but recommend the surface to be well pro- tected. For cleanliness, cold bathing and friction hold the first rank. The effect of cold is to improve apparently the nutrition of the skin, so that it. afterward acts more readily, and when combined with friction, it is curious to see how the very color and textiire of the skin manifestly im- prove. The effect of heat on the skin, and especially the action of the Eoman or Turkish baths, and their action on health, have certainly not yet beert properly worked out, in spite of the numerous papers which have been written. It has not been proved that the strong action of the Turkish bath is more healthy in the long run than the application of cold water. As a curative agent, it is no doubt extremely useful ; but as a daily cus- tom, it is yet sub judice. Certainly it should not be used without the concluding application of cold to the surface. Attention has been often very properly directed to the effect of lead and mercurial hair-dyes. It may be worth while to notice that there is a case on record ^ in which not only was paralysis produced by a lead hair- wash, but lead was recovered from the base of the left hemisphere of the brain. Snuff containing lead has also caused poisoning. The care of the bowels is another matter of personal hygiene, and is a matter of much greater difficulty than at first sight appears. Constipation, as allowing food to remain even to decomposition, as leading to distention and sacculation of the colon, and to hemorrhoids, is to be avoided. But, on the other hand, the constant use of purgative medicine is destructive of digestion and proper absorption ; and the use of clysters, though less ably 30 per cent, of the persons who consult physicians owe their diseases in some way to food, and in many cases they are perfectly aware themselves of their error or bad habit, but, with the singular inconsistency of human nature, either conceal it from the man to whom they are professing perfect openness, or manage to blind themselves, to its existence. ' Compare the imperfect development of the muscles of the arms in ladies, as shown by the low evening dresses, with the women of the working classes. No one can doiibt which is healthiest or which is the most beautiful, until excess of work develops in the muscles of the laboring women the too hard outlines of middle life. 2 Virchow's Archiv, Band viii., p. 177. 122 PRACTICAL HYGIENE. hurtful to the stomach, and less objectionable altogether, is by no means desirable. On the whole, it would seem that proper relief of the bowels can be usually iusui'ed by exercise, and esi^ecially by bringing the abdomi- nal muscles into play, and by the use of certain ai-ticles of diet — viz., piu'e water in good quantity with meals, the use of bran bread, honey, and such gently laxative food ; and that if these do not answer well, it is better to allow- a certain amount of constipation than to fall into the frequent use of purgative medicines. The regulation of the passions must also be left to the indi^iduaL The control of morals has baffled the exertions of the priest and the statesman ; but perhaps the influence of sexual ii'regularities on health has never been made the subject of judicious education. The period of puberty corre- sponds •«"ith the most important period of gi'owth, when the bones are consohdating and uniting, and both muscles and nerves are lai'gely ab- sorbing nouiishment, and are developing to their fullest power. The too early use of sexual congi'ess, and even more the di*ain on the system pro- duced by sohtary vice, arrests this development to a considerable extent, and prevents the attainment of the strength and endurance which would insure a healthy, rigorous, and happy life. The venereal diseases, which so waste many of the younger men, form only an item in the catalogue of erils — evds which effect at a subsequent period wives and children, and by imdermining the health and hapjDiness of the family, influence the state itself. "We know that a wide-sj)read profligacy has eaten away the rigor of nations and caused the downfall of states ; but we hardly recognize that, in a less degree, the same causes ai^e active among us, and never realize what a state might be if its citizens were temperate in all things. It may be difficult to teach these points to the young, and to ui-ge upon them, for their o\vn and others' sakes, the regulation of the passions which physi- ology teaches to be necessaiy for personal happiness, for the welfare of the offspiing, and for healthy family life ; but I think few can doubt that, in some way, the knowledge should be given. The amount of mental work, and the practice of general good temper and cheerfulness and hope, are other points which each man must himself control. Great mental work can be borne well if hygienic principles of diet, exercise, etc., be attended to. The old authors paid gi-eat attention to the regimen of men engrossed in literary M'ork, and laid down particular rides, insisting especially on a very cai'eful and moderate diet, and on ex- ercise. ' Hope and cheertvdness are great aids to health, no doubt, from their effect on digestion. Usually, too, they are combined with a quick and ac- tive temiDerament, and with rapid bodUy movements and love of exercise. The individual application of general hygienic miles will differ accord- ing to the sex and age," and the circumstances of the person. In the case of children, we have to apj)ly the general i-ules with as much caution and care as possible, as we must depend on external evidence to prove their ' Plutarcli, whose rules on health are excellent and chiefly taken from Hippocrates, compares the over-studious man to the camel in the fable, who, refusing to ease the ox in due time of his load, was forced at last to carry not only the ox's own load, but the ox himself, when he died under his burden. -' Galen was the first who pointed out explicitly that hygiene rules must be diffes- ent for in.ancy, youth, manhood, and old age — a fourfold division which is still the best. Pythagoras, Iccus, Herodicus, Hippocrates, Polybius, Diodes, Celsus, and others who preceded Galen, appear to have framed rules chiefly for male adults. Galen sub- divided the sub'ect much more systematically. (For a good short account of the early systems, see .Jlackenzie on Ihe History of Health, and the Art of Preserving it, 1758.) INDIVIDUAL HYGIENIC MANAGEMENT. 123 utility. In the case of adults, individual experience soon shows whether or not a prescribed rule is or is not beneficial, and what modification must be made in it. It is not, however, every grown person who has the power to modify or change his condition. He may be under the influence of others who, in fact, arrange for him the cii'cumstances of his life. But still, in no case is aU self-control taken away ; the individual can always influence the conditions of his own health. Were the laws of health and physiology better understood, how great would be the effect ! Let us hope that matters of such gTeat moment may not always be considered of less importance than the languages of extinct nations, or the unimportant facts of a dead history. CHAPTER XVII. DISPOSAL OF THE DEAD. In densely populated countries the disiDosal of the dead is always a ques- tion of diificulty. If the dead are buried, so great at last is the accumula- tion of bodies that the whole country round a gTeat city becomes gradually a vast cemeter)'.' In some soils the decomposition of bodies is veiy slow, and it is many years before the risk of impui'ities passing into au- and wa- ter is removed. After death the buried body returns to its elements, and gradually, and often by the means of other forms of hfe which prey on it, a large amoiuit of it forms carbon dioxide, ammonia, carburetted hydrogen and hydi-ogen sulphide, nitrous and nitric acids, and vaiious more complex gaseous prod- ucts, many of which are veiy fetid, but which, however, are eventually all oxidized into the simpler combinations. The non-volatile substances, the salts, become constituents of the soil, pass into plants, or are carried away into the water percolating through the gi-ound. The hardest parts, the bones, remain in some soils for many centui'ies, and even for long periods retain a portion of their animal constituents. If, instead of being buried, the body is burned, the same process occirrs more rapidly and with different combinations ; carbon dioxide, cai'bon mon- oxide (?), nitrogen, or perhaps combinations of nitrogen, water, etc., are given off, and the mineral constituents, and a little carbon, remain behind. A community must always disj)ose of its dead either by burial in land or water, or by burning, or chemical destruction equivalent to burning, or by embalming and pi*eserving. Accustomed as Ave are to land burial, there is something almost revolting, at first sight, at the idea of making the sea the sepulchre, or of burning the dead. Yet the eventual disj)ersion of our frames is the same in all cases ; and it is probably a matter merely of cus- tom which makes us think that there is a want of affection, or of cai'e, if the bodies of the dead are not suffered to repose in the earth that bore them. In reality, neither affection nor religion can be outraged by any manner of disposal of the dead which is done with proper solemnity and respect to ' Nothing, perhaps, testifies more strongly to the antiquity and the extent of the an- cient cities in Anatolia than the vast sepulchral remains. On the site of Old Dardanus, the mother of Troy, and stretching from the Hellespont for two or three miles into the hills, the -whole country is honeycombed with tombs. It is the same in the neighbor- hood of Troy. The burial of the dead, though practised by the most ancient nations, was afterward superseded by burning, and was only subseqviently returned to. As, therefore, these graves represent only a portion of the duration of the city, the immense assemblage of tombs is the more remarkable, and it is impossible to avoid the conclu- sion that these great cities must have flourished for periods far longer than those which have elapsed since London or Paris, for example, became large centres of population. DISPOSAL OF THE DEAD. 125 the eartlily dwelling-place of our friends. Tlie question should he placed entii'ely on sanitary gi'ounds, and we then shall judge it rightly. What, then, is the best plan of disposing of the dead, so that the hving may not suffer ? It seems hardly hkely that the practice of embalming or mummifying will ever again become common. What is the use of preserving for a few more years the remains which will be an object of indifference to future generations ? The next logical step would be to enshi'ine these remains in some way so as to insui-e theii' preservation, and we should return to the vast burial mounds of Egypt. The question will he between buiial in the land or at sea, and burning. At present the question is not an urgent one ; but if the population of Europe continues to increase, it will become so in another century or two, Akeady in this country we have seen, in our own time, a great change ; the objectionable practice of interment under and round churches in towns has been given up, and the population is bmied at a distance from their habitations. For the present that measui-e will jDrobably sulfice, but in a few years the question will again inevitably present itseh. Burying in the ground appears certainly the most insanitaiy plan of the three methods. The air over cemeteries is constantly contaminated, and water (which may be used for drinkingj is often highly impui-e. Hence, in the vicinity of graveyards two dangers to the population arise, and in addi- tion, from time to time, the disturbance of an old gTaveyard has given rise to disease. It is a matter of notoriety that the vicinity of graveyards is unhealthy. How are these dangers to be avoided? The dead may be buried in more or less aii'-tight vaults ; here decay is slow ; the products form and escape slowly, though they must eventually escape ; the air and water are less contaminated. But the immense expense of such a plan ren- ders it impossible to adopt it for the community generally. Deep buning has the advantage of greater filtration, both for air and water, than shallow burying, and hence it is a good rule to make the gTave as deep as possible, and to allow no more than one body in a grave. The admixtui'e of quick- lime has been advised ; it absorbs some carbon dioxide, and forms calcium sulphide with the sulphiu" and hydrogen sulphide, but this itself soon de- composes, so that the expense of quicklime seems hardly commensurate with the result. Charcoal would absorb and oxidize the fetid organic mat- ter, and, if sufficiently cheap, would be a valuable substance to be heaped in graves ; but its cost would be probably too great, nor does it entirely hinder putrefaction and the evolution of foul-smelling substances (H. Bar- ker). If a body has to be kept unburied for some time, sawdust and sul- phate of zinc, in the proportion of two parts to one, has been found by Her- bert Barker, ' to be the best apphcation ; a thin layer is put over the dead body ; or sawdust is spiinkled on the body, and then two or thi'ee inches of carboUc acid thrown over it. The only means which present themselves, as apphcable in all cases, are the deep burial and the use of j^lants, closely placed in the cemetery. There is no plan which is more efficacious for the absorjDtion of the organic sub- stances, and perhaps of the carbon dioxide, than plants, but it would seem a mistake to use only the dark, slow-growing evergi-eens. The object should be to get the most rapidly growing trees and shrubs, and, in fact, there is no reason, except a feeling of sentiment, why we should introduce into our cemeteries the gloomy and melancholy cypress and yew. Mr. ' Deodorization aud Disinfection, Britisli Medical Journal, January, 1866. 126 PRACTICAL HYGIENE. Seymour Haden has called attention to the supposed advantages of perish- able coffins, so that the putrefactive changes may be carried out as quick- ly as possible. And certainly, if buiying is to continue, it seems reasonable that no undue obstacle should be placed in the way of changes which are sooner or later inevitable. When, in the course of years, it becomes imperative to reconsider this question, and land burial will have to be modified, some arguments may present themselves to maritime nations in favor of bur^ing in the sea ra- ther than of burning. In the burial at sea, some of the body at least would go at once to siipport other forms of life, more rapidly than in the case of land burial, and without the danger of evolution of hurtful products. Burning, or cremation, has attracted much attention of late years. In this country the subject has been discussed by Sii' Henry Thompson and ]Mi'. Eassie, and abroad much has been written, especially in Germany and Italy, in both which countries the method has been practically tried. It would ceriainly appear that the body can be disposed of in a veiy short time and in an inoffensive manner, while the expense would unquestion- ably be much reduced if the practice became general. One hour appears sufficient to reduce a body to ashes, and it has been successfully tried in this country. The only really valid argument against cremation is the possible con- cealment of crime, such as poisoning. This, however, might be guarded against by suitable precautions. In time of war, and especially in the case of beleaguered fortresses, the disposal of the dead becomes often a matter of difficiilty. In that case burning may have to be resorted to. If the bodies are bm-ied, they should always be at as gi'eat a distance as possible, and as deep as they can be. If procui'able, charcoal should be thrown over them ; if it cannot be ob- tained, sawdust and sulphate of zinc, or carbohc acid may be employed. Quickhme is also commonly employed, but it is less useful. At Metz, in 1870, the following plan was adopted : — A pit of about 17 feet in depth was filled with dead, disposed of as follows : — A row of bodies was laid side by side ; above this a second row was placed, with the heads laid against the feet of the first row ; tlie thu-d row were placed across, and the fourth row in the same way, but with the heads to the feet of the former ; the fifth row were placed as No. 1, and so on. Between each layer of bodies about an inch of lime, in powder, was placed. From 90 to 100 bodies were thus arranged on a length of 6^ feet, and reached to about 6 feet fi-om the sm-face ; the pit was then fiUed up \\-ith earth, and though 8,400 bodies were put in that pit, there were no perceptible emanations at any time. Around Metz the graves of men and horses and cattle were disinfected with lime, chai'coal, and stdphate of u'on. Immense exeiiions were made to clean and disinfect the camps and battle-fields, and in the month of May, 1871, from 1,200 to 1, GOO laborers were employed by the Gei-mans. Wherever practicable, the groimd was sown "s\dth oats or barley or grass. The hillocks formed by the graves were planted with trees. In many cases, at Metz, bodies were dug up by the Germans when there was any fear of watercourses being contaminated, or if houses were near. On account of the danger to the workmen, graves containing more than six bodies were left untouched, and the work was always done under the immediate superintendence of a physician. The earth was removed carefully, but not far enough to uncover the coi-jDse ; then one end of the coi-pse was uncovered, and as soon as unifonn or parts of the body were DISPOSAL OF THE DEAD. 127 seen, cliloride of lime and sawdust, or charcoal and carbolic acid, put in ; the whole earth round the body was thus treated, and the body at length laid bare, lifted and carried away. The second body was then treated in the same way. Near Sedan, where there were many bodies very superficially biuied, biu'ning was had recourse to. Straw mixed with pitch was put into the graves, and was Ughted ; 1 ton of pitch sufficed for from 15 to 20 bodies. Opinions as to this practice were divided, and it is not certain how many graves were thus dealt with. It seems probable that only the surface of the body was bm-nt, and when many bodies were together in one grave some were not touched at all. On the whole, the exj)eriment appears to have been unsuccessful. The Belgian experience at Sedan was in favor of employing chloride of Hme, nitric acid, sulphate of ii'on, and chloiine gas. Carbohc acid did not answer so well. The sulphate of zinc and charcoal, which Barker found' so useful, was not tried. Mr. Eassie has lately called attention to the desirability of an ambula- tory cremation furnace for the disposal of bodies in war. If such an arrangement proved practicable, it would unquestionably be of immense advantage from a hygienic point of view. . CHAPTER XVIII. ON THE PREVENIION OF SOME IMPORTANT AND COMMON DISEASES. There are two modes by which we may attempt to prevent the occurrence of disease. 1. By conforming with the general rules of hygiene, by which the body and mind ai-e bi'ought into a state of more vigorous health. 2. By investigating and removing the causes of the diseases which we find actually in operation. This pai-t of the inquiiy is in fact a necessary sujDplement to the other, tliough in proportion to the obsei-vance of the general niles of hygiene, the causes of disease will gradually be removed. At present, however, we have to deal -with the facts before us, — viz., that there are a great number of diseases actually existent which must form the subject of investigation. We proceed in this case from the particular to the general, whereas, in the first mode, we deduce general rules which have to be apphed to individual instances. Hygiene is in this dii-ection an aj^plication of etiology, and etiology is the philosophy of medicine ; while in its turn the veiy foundation and basis of etiology is an accurate diagnosis of disease. Unless diseases are com- pletely identified, all inquuy into causes is hopeless. Let us remember, for example, what utter confusion prevailed in our opinions as to causes and preventive measures at the time when typhus and typhoid fevers were considered identical, or when paroxysmal fever and the true yellow fever or vomito were thought to o^vn a common cause. Auy useful rules of prevention were simply impossible — as impossible as at present in many of the diseases of nutrition, which, in the projjer sense of the word, are yet undiagnosed. The advance of diagnosis has of late years been owing not merely to improved methods of observation, but to the more complete recognition of the great principle of the invaiiableness of causation. The sequence of phenomena in the diseased body proceeds with the same regularity and constancy as in astronomy or chemistiw. Like causes always produce like effects. To suppose that from the same cause should proceed a sequence of phenomena so utterly distinct as those of typhus and typhoid fever, now seems incredible ; yet ■nith a full, or at any rate a sufficient knowledge of the phenomena, it was at one time almost universally beheved that these two perfectly distinct diseases owned a common origin. At the present moment, the superficial resemblance between gout and rheumatism causes them to be put together in almost all systems of nosolog}', although, with the exception of the joints being affected, the diseases have almost nothing in common. In proportion as this great piinciple is still more constantly apphed, PEEVENTION OF DISEASE. 129 and as our means of diagnosis advance, and consequently, causes are more satisfactorily investigated, methods of prevention will become obvious and precise. At present they are very far from being so. In many cases they are founded on very imjDerfect observation ; and very frequently all that can be done is to apply general sanitary rules, without attempting to de- termine w^hat are the special preventive measures which each disease re- quires. It is not necessary, however, that we should wait until the causation of any disease is perfectly understood. We must act, as in so many other affairs, on probability ; and endeavor to remove those, conditions which, in the present state of our knowledge, seem to be the most likely causes of the disease. It may be that, in some cases, we may be attacking only subsidiary or minor causes, and may overlook others equally, or more important. In some cases, indeed, we may overlook entirely the effective causes, and may be fighting with shadows. Still, even from mistakes, progress often arises — indeed, the difficult path of human knowledge is perhaps always through error. The term cause is applied by logicians to any antecedent which has a share in producing a certain sequence ; and it is well known that in many diseases two sets of causes are in operation — one external and one internal to the body (exciting and predisposing). The investigation of the internal causes, which in some cases are necessary to the action of the external causes, is equally curious and intricate as that of the external causes, and in some respects it is even more obscure ; but measures of prevention must deal with them, as well as with the external causes. In this chapter we can, of course, only venture to enumerate very briefly, and without discussion, what seem to be the best rules of prevention for the principal diseases of soldiers. To enter on the great subject of the pre- vention of disease generally, and to discuss all the complicated questions connected with causation, would demand a volume. SECTION I THE SPECIFIC DISEASES. Paroxysmal Fevers. External Cause. — This was presumed to be putrescent, or, at any rate, decomposing vegetable matter derived from a moist and putrescent soil, which was carried into the body by the medium of water or of air. But the later views of Klebs and Tommasi-Crudeli attribute it to a low organism of the nature of Bacillus, to which they have given the name Bacillus malarice, propagated in the presence of decaying vegetable matter. If the ingestion is by water, a fresh source must be obtained. Well- water is generally safe, but not always. Eain-water may be unsafe, if the tanks are not clean. ' If a fresh source cannot be obtained, boiling, filtra- tion, and alum appear to be the best preventive measures,'^ If the introduction be by air, and if the locality cannot be left, the most approved plan is elevation to at least 500 feet above the source of the poison ' For an instance of propagation Tby so-called rain-water, see cases at Tilbury Fort, Volume I., page 49. ^ Dr. Blanc and Mr. Prideaux preserved themselves from intermittent fever, in a march in Abyssinia, by always using water in the form of tea or coffee. Vol. II.— 9 130 PRACTICAL HYGIENE. in temperate climates ; and 1,000 to 1,500 feet in the tropics, or higher still, if ix)ssible.' If this phiu camiot be adopted, two jjoints must be aimed at — \'iz., to obviate local, and to avoid daifting malaria. Thorough subsoil draining ; filling up moist gi'ound when j^racticable ; pacing or coveriug the ground -nith herbage kept closely cut, are the best plans for the first point. For the second, belts of trees, even walls can be interposed ; or houses can be so built as not to present ojDenings toward the side of the malarious cun-ents. The houses themselves should be raised above the gi'ouud on arches ; or, if wooden, on piles. Uj^per floors only should be occupied. The early morning air, for thi-ee houi-s after sunrise, should be avoided ; and next to this, night air. IiUernal Causes. — The conformation, or structui'al condition, which pei-mits the external cause to act, is e"S"idently not equal in different individuals, or in different races ; but we ai-e quite ignorant of its natvu-e. It is not removed by attacks of the disease ; but, on the contraiy, after re- peated attacks of ague, a pecuhar condition is produced, in which the dis- ease can be brought on by causes, such as cold or dietetic eiTors, which could never have caused it in the first instance. The internal predisposi- tion is gi-eatly heightened by poor feeding, anaemia, and jn-obably by SCUVYJ. To remove the internal causes our only means at present are the administration of antiperiodics, especially quinine ; and good and gen- erous hving, with ii'on medicines. The use of flannel next the skin, and of warm clothing generally ; waiTu coffee, and a good meal before the time of exjDosiu-e to the malaria, and perhajDS moderate smoking (?), are the other chief measures. "Wine in modei'ation is part of a generous diet ; but spirits are useless, and probably hurtful, unless given considerably dilute d. Yelloiv Fever. External Cause. — Dui-ing the last few years the progress of inquiry has entirely disconnected ti-ue yellow fever from malaria, though yellowness of the skin is a symptom of some malarious fevers. Yellow fever is a disease of cities and of parts of cities, being often singidarly localized, hke cholera. In the "West Indies it has repeatedly attacked a bairack (at Bermuda, Trinidad, Bai-badoes, Jamaica), while no other place in the whole island was affected. In the same way (at Lisbon, Cadiz, and many other places) it has attacked only one section of a town, and, occasionally, like cholera, only one side of a street. In the "West Lidies, it has repeatedly commenced in the same pari of a baiTack. In all these jjoints, and in its frequent oc- ciu'rence in non-malarious places, in the exemption of highly malarious places, in its want of relation to moistm-e in the atmosphere, and its as evi- dent connection with putrefying fecal and other animal matters, its cause differs entirely from malaria.^ If these points were not sufficient, the fact that the agent or poison ■which causes yellow fever is portable, can be carried and introduced among ' It must be understood that these heights are assumed to be abore a marsh. They will not secure from malaria from marshes, if situated at tliat or a much greater height. A marsh at Erzeroum is 6,()0U feet above sea- level ; one at Puebla, in New Mexico, is 5,00U feet ; both cause fevers. '-' The belief in the malarious origin of yellow fever, so long and tenaciously held by many American physicians, seems to be losing ground. (See paper by Dr. Ferry, read before the American Health Association, The Daily Picayune, November 23, 1873.) PKEVENTION OF DISEASE. 131 a community, ' and is increased in the bodies of those whom it attacks, in- dicates that the two agencies of yellow fever and paroxysmal fevers are entirely distinct.^ That great point being considered settled, the inquity into the condi- tions of the spread of yellow fever becomes easier. The points to seize are its frequent and regular localization and its transportation. The locali- zation at once disconnects it from any general atmospheric wave of poison ; it is no doubt greatly influenced by temperature, and is worse when the temperature is above 70° Fahr. Though it wih continue to spread in a colder air than was formerly supposed, it does not spread rapidly, and ap- pears to die out ; but even temperature does not cause it to become gen- eral in a place. The localizing causes are evidently (cases of Lisbon, Gibraltar, West Indies, etc.) connected with accumulation of excreta round dwellings, and overcrowding. Of the former there are abundant instances, and it is now coming out more and more clearly that, to use a convenient phrase, yel- low fever, like cholera and typhoid fever, is a fecal disease. And here we find the explanation of its localization in the West Indian barracks in the olden time. Eound every barrack there were cesspits, often open to sun and air. Every evacuation of healthy and sick men w^as thrown into per- haps the same places. Grant that yellow fever was somehow or other in- troduced, and let us assume (what is highly pi'obable) that the vomited and fecal matters spread the disease, and it is evident why, in St. James' Barracks at Trinidad, or St. Ann's Barracks at Barbadoes, men were dying by dozens, while at a little distance there was no disease. The prevalence on board ship is as easily explained. Granted that yellow fever is once imjDorted into the ship, then the conditions of spread are probably as fa- vorable as in the most crowded city ; planks and cots get impregnated vsdth the discharges, which may even find their way into the hold and bilge. No one who knows how difficult it is to help such impregnation in the best hospitals on shore, and who remembers the imperfect ai-rangements on board ship for sickness, will doubt this. Then, in many shijjs, indeed in almost all in unequal degrees, ventilation is most imperfect, and the air is never cleansed. Overcrowding, and what is equivalent, defective ventilation, is another great auxiliary ; and Bone ^ relates several striking instances.^ ' Cases of the Bann, Eclair, Icarus, and several others. The remarkable introduc- tion of yellow fever from Havana into St. Nazaire, in France (near Brest), is most striking, and cannot be explained away. It spread both from the ship, and. in one instance, from persons. (See Aitken's Medicine, 7th edit. , 1880 ; and Report on Hy- giene for 1862, in the Army Medical Report, by Dr. Parkes.) The introduction into Rio in 1849, and into Monte Video, are still more striking cases of importation ; and a case very similar to that of St. Nazaire occurred some years ago at Swansea. (See Re- port (by Dr. Buchanan) to the Medical Officer of the Privy Council, 1866.) ^ As more care is taken, the symptoms of the two diseases also are found to be diag- nostic, and if it were not for the constant use of the unhappy term '"remittent," the confusion would not have so long prevailed. An interesting instance of good diagnosis was made by the French at Vera Cruz in 1861. In the spring the vomito prevailed, and then disappeared. Some months after- ward, cases of a disease occurred so like yellow fever that they were at first taken to be that disease, but on a closer examination they were found to be clearly paroxysmal, and to yield to quinine. — Rec. de Mem. de Med. Milit., 1868. 2 Yellow Fever, by G-. F. Bone, Assistant, Surgeon to the Forces. * For example, in the same barrack, the windward rooms have been quite healthy, and the leeward rooms attacked. Men in the latter have ceased to have cases of the disease when moved to the former locality. (See a good case in Bone, op. cit., p. 13.) 132 PRACTICAL HYGIENE. The question of the origin of yellow fever is one which cannot be con- sidered in this work, and at present no preventive rules of importance can be drawn from the discussion. The chief preventive measures for the external cause ai-e these : — 1. The portability being proved, the gi-eatest care should be taken to prevent introduction, either by sick men, or by men who have left an in- fected ship. The case of the Anne Marie ' has made it quite uncertain what period of time should have elajDsed before an infected ship can be considered safe ; in fact, it probably cannot be safe until the cai'go has been discharged and the ship thoroughly cleansed. Still, it appears, that if men leaving an infected place or ship pass into places well ventilated and in fair sanitary condition, they seldom carry the disease ; in other words, the disease is seldom portable by men, but it will occur. It appears neces- sary, also, to consider that the incubative period is longer than usually supposed, probably often fourteen or sixteen days. In the case of a ship, it seems desirable not to consider danger over imtil at least twenty days have elapsed since the cure or death of the last case, and even at that time to thoioughly fumigate the ship with chlorine and nitrous acid before the cargo is touched. Men Avorkiug on board such a ship should work by re- lays, so as not to be more than an hoiu- at a time in the hold," In case men sick with yellow fever must be received into a barrack or hospital, they should be isolated, placed in the best ventilated rooms at the top of the house, if possible, or, better still, in separate houses, and all dis- charges mixed with zinc sul^Dhate and zinc chloride, and separately disposed of, and not allowed to pass into any closet or latrine. 2. The introduction by drinking-water not being disproved, care should be taken that the possibility of this mode of introduction be not over- looked. 3. Perfect sewerage and ventilation of any station would probably in great measure preserve fi'om yellow fever, but in addition, in the yellow fever zone, elevation is said to have a very great effect, though the confusion between malarious fevers and the vomito renders the evidence on this point less certain, and its introduction into Newcastle in Jamaica (4,200 feet), and itsfi'equent occurrence at Xalapa (4:,330 feet), as well as its prevalence on high points of the Andes (9,000 feet) (A. Smith), show that the effect of mere elevation has been overrated. Still, as a matter of precaution, stations in all yellow fever districts should be on elevations above 2,000, and if j)ossi- ble 3,000 feet. 4. If an outbreak of yellow fever occiu' in a barrack, it is impossible then to attempt any cleansing of sewers ; the only plan is to evacuate the barracks. This has been done many times in the West Indies with the best effects. As a preventive measure, also, evacuation of the barracks, and encamjiment at some little distance, is a most useful plan. Before the barrack is I'eoccupied, every possible means should be taken to cleanse it ; sewers should be thoroughly Hushed ; walls scraped, limewashed, and fu- migated with nitrous acid. If a barrack cannot be altogether abandoned, the gi'ound floors should be disused. There are several instances in which persons living in the lowest story have been attacked, while those above have escaped. ' See Aitken's Medicine, and Report on Hjgiene in the Army Medical Report for ^ Dr. Perry (op. cit.) considers quarantine useless, and advises a most rigorous sys- tem of disinfection. He cites eight instances of the introduction of yellow fever through a strict quarantine, seven to New Orleans, and one to Pensacola. PEEVENTION OF DISEASE. 133 5. In all buildings where sick are, or where yellow fever prevails, there should, be constant fumigation with nitrous acid, which seems to be, as far as we know, the best disinfectant for this disease. 6. If it appeal's on board ship, take the same precautions ■v\ith regard to evacuations, bedding, etc. Treat all patients in the open air on deck, if the weather permit ; run the ship for a colder latitude ; land all the sick as soon as possible, and cleanse and fumigate the ship. Internal Cause. — Recent arrival in a hot country has been usually as- signed as a cause, but the confusion between true yellow fever and severe febricula (ardent fever or causus) and malarious fevers, renders it un- cei-tain how far this cause operates. ' Still, as a matter of precaution, the present plan of three or four years' MediteiTanean seiwice before pafesing to the West Indies seems desirable, although this has been questioned by some experienced officers. Difterent races possess the peculiar habit which allows the external cause to act in veiy different degi'ees ; this is marked in the cases of negroes and muJattoes as compared with white men, but even in the European nations it has been supposed that the northern are more subject than the southern nations. Of the sexes, women are said to be less liable than men. This predisposition is increased by fatigue," and it is said, especially when combined -mih. exposui'e to the sun ; by drinking, and by improper food of any kind which lowers the tone of the body. No prophylactic medicine is known ; quinine is quite useless. Little, therefore, can be done to avert the internal causes, except care in not undergoing gi-eat fatigue, temperance, and proper food. The exter- nal conditions are the most imj^ortant to attend to. Dengue. This disease, which has attracted much attention of late years, appears to bear some relation to yellow fever, not in its pathological characters, but in the time of its ajDpearance and geographical distribution. It has, how- ever, prevailed in Asia, where yellow fever has hitherto been unknown. In Egypt (according to Vauvray) it is seen at the time of the date-harvest, and is known as " date fever." In other parts of the world it has been attributed to vegetable emanations. Although its symptoms are those of blood- poisoning, it may be doubted if this is due to vegetable emanations only. Dr. J. Christie ^ thinks that the Deng-ue of the Eastern and the Dandy fever of the Western Hemisphere are varieties of the same disease, pro- duced in the one case by the virus of yellow fever, and in the other by that of cholera, modified by local conditions of an insanitary kind, chiefly de- composition of bodies improperly interred. He suggests general hygienic measm-es, and especially improved methods of burial, as the best preven- tives. ' In the old times in Jamaica it was, ho-n-ever, always noticed that the worst attacks occurred in regiments during the first twenty-four, and especially the first twelve months. In thirteen epidemics in different regiments, four occurred in less than six months after landing, seven in less than twelve months, and two in less than twenty- four months. But it has been stated that residence in one place, though it may secure against the yellow fever of that, does not protect against the disease in another locality. It is much to be wished that all these assertions which abound in books should be tested by figures. That is the only way of coming to a decision. - Arnold, Bilious Remittent Fever, "1840, p. 82. ^ Transactions of the International Medical Congress, 1882, vol. iv., p. 636. 134 PRACTICAL HYGIENE. Cholera. External Cause. — As in the case of yellow fever, we have no cei-tain clue to the origin of cholera,' and in some respects the propagation of the dis- ease is veiy enigmatical. The way, for example, in whicli the disease has sjDread over vast regions, and has then entirely disappeared)^ and the mode in which it seems to develop and decline in a locality, in a sort of regular order and at certain seasons, are facts which we can only imjDerfectly ex- plain. But as far as preventive measures are concerned, the researches of late yeai's seem to have given us indications on which we are bound to act, though they ai'e based only on a partial knowledge of the laws of spread of this poison. These indications are — 1. The portabihty of the disease, i.e., the carriage of cholera from one place to another by persons ill with the disease, both in the earliest stage (the so-called premonitory diarrhoea), and the latter period, and in conva- lescence.^ The caiTiage by healthy persons coming from infected districts is not so certain ; but there is some evidence.^ It is clear this last point is a most important one, in which it is desirable to have more complete evidence. The occasional can-iage by soiled clothes, though not on the whole common, has also evidence in its favor. All these points were affirmed by the Vienna Conference of 1874. Even Pettenkofer admitted that inan is the carrier of the disease germ, although the locality may be the means of rendering it potent. On the other hand, Dr. J. M. Cuningham '' makes a tabula I'asa of eveiwthing, denies the transportabihty of the disease either by persons or by water, and says there is a mysterious factor still to be sought for. His evidence, however, cannot be considered as conclusive. WTiatever may be the final opinion on all these points, we are bound to act as if they were j^erfectly ascertained. It is usually impossible to have rigid quarantines ; for nothing short of absolute non-communication would be useful, and this is impossible except in exceptional cases. For persons very shghtly ill, or who have the disease in them but are not yet ajDparent- ly ill, or possibly who are not and ^-ill not be ill at aU, can give the disease, and therefore a selection of dangerous persons cannot be made. Then as the incubative stage can certainly last for ten or twelve days, and there are some good cases on record where it has lasted for more than twenty, it is clear that quarantine, unless enforced for at least the last period of time, ' The researches of Lewis and D. D. Cunningham in India, and of Eberth, of Zurich (Zur Kenntniss der Bacteritischen Mvkosen, von J. C. Eberth, 1873), have shown that no specific germ has been yet discovered, and have disproved the fungoid and other origins proposed bv Hallier, etc. '^ There is, of course, no doubt that the common autumnal cholera, however much it may resemble superficially the Indian cholera, is quite a separate disease. ^ With respect to convalescence, the only evidence is apparently that given by Tolz, quoted by Hirsch, Jahresb. fiir ges. Med., 1868, Band ii., p. 221. * Especially in the Mauritius outbreaks, where parties of coolies coming from places where cholera prevailed, but being themselves healthy, gave cholera to other parties of coolies who had arrived from India, and had no disease among them. Dr. Leith Adams (Army Medical Report, vol. vi., p. 348), in his excellent Report on Cholera in Malta, states : " There are many pointed facts to show that cholera may be introduced and communicated to susceptible persons by healthy individuals from iufected dis- tricts. " * Ninth Annual Report of the Sanitary Commissioner with the Government of India. PEEVENTIOIT OF DISEASE. 135 may be useless. The constant eyasions also of the most strict cordon render such plans always useless. An island, or an inland village, far removed from commerce, and capable for a time of doing w^ithout it, may practise quarantine and preserve itself ; but, in other circumstances, both theory and actual experience show that quarantine fails.* M. Fauvel ^ believes that the quarantine measures adopted in the Red Sea have been instrumen- tal in preventing the spread of cholera to Europe on three separate oc- casions, namely, 1872, 1877, and 1881. This difficulty, however, of carrying out efficient isolation is no argument against taking every precaution against communication, and keeping a strict watch and control over every possible channel of introduction. In this waj^, by isolation of the individual, or of bodies of men, as far as possible, and by looking out for and dealing with the earliest case, an out- break may perhaps be checked, especially by discovering the diarrhoeal attacks, and by using disinfectants both to the discharges and to linen.^ In the case of troops coming from infected districts they should be kept in separate buildings for twenty days, and ordered to use only the latrines attached to them, in which disinfectants should be freely used. 2. The introduction of the disease into any place by j)ersonsis considered by most observers to be connected with the choleraic discharges, either when newly passed, or, according to some, when decomposing. The reasons for this are briefly these : the portability being certain, the thing carried is more likely to be in the discharges from the stomach and bowels than from the skin or breath (the urine is out of the question), and for these reasons : Water can communicate the disease, and this could only be by contamination with the discharges ; water contaminated by discharges has actually given the disease, as in Dr. Macnamara's cases ; in some cases a singTilarly local origin is proved, and this is nearly always a latrine, sewer, or receptacle of discharges, or a soil impregnated with choleraic evacuations ; soiled linen has sometimes given it, and this is far more likely to be from discharges than from the perspiration ; animals (white mice and rabbits) have had cholera produced in them from feeding on the di'ied discharges. Finally, in the history of the portability of cholera, there are many in- stances in which, while there has been decided introduction by a diseased person into a place, there has been no immediate relation between that person and the next case ; in other words, the cause must be completely detachable from the first case, and must be able to act at a distance from his body ; it is therefore far more probable that the discharges are this ' When circumstances are favorable (as respects trade and intercourse), however, good quarantine may be successful even on the mainland. This was shown in Algeria in 1861. See Dr. Dukerley's Notice sur les Mesures de Preservation prises a. Batna (Algerie) pendant le Cholera de 1867, Paris, 1868, for a very interesting account of those successful measures of which strict isolation and constant hygienic measures were the principal. So also in America, Dr. Woodward states (Circular on Cholera, No. 5, Surgeon-General's Oflce, Washington, 1867) that "the general tenor of army experience is strongly in favor of quarantine." Quarantine on land was condemned by the Vienna Conference, but recommended on the Red Sea and the Caspian. In Europe, however, only rigorous inspection was recommended, with various rules for preventing spread as much as possible. ■■^ Revue d'Hygiene, vol. iv., 1882, p. 754. ^ The Indian Government are now cautiously attempting to limit the spread of cholera by superintending and controlling the pilgrimages, which are so common a cause of the spread of cliolera in India. The Report of the Cholera Committee (In- spector-General Mackenzie, Colonel Silva, and Dr. Ranking) to the Madras Government, published at Madras in 1868, gives a great deal of important evidence on this point, and in addition lays down excellent rules for the management of pilgrimages. 136 PRACTICAL HYGIENE. carrying agency, tlian that any effluvia should pass off from the lungs and skin which could spread to a great distance. Enough has been said to show that the discharges must receive the most careful attention. Every discharge ought to he disinfected with strong substances liberally used ; the best are carbolic acid (in large quantity), perchloride of iron, chloride of zinc, chloride of lime, or, if none of these are at hand, good quicklime. Although the results of disinfection of the discharges have not hitherto been encouraging, the plan has seldom been completely tried. All latrines should be disinfected, sewers flushed, car- bolic acid poured down them, and every means taken to keep them ven- tilated. What should be done with the disinfected discharges? Should they be allowed to j)ass into sewers, or buried in the ground ? They must in some way be got rid of. Sewers certainly afford an easy mode of disposing of them ; and as the discharges are mixed with much watex', and are rapidly swept away in them, and as the temperature of the sewers is low, and decomposition is delayed, it is quite possible that sewers may be a means of freeing a town from choleraic discharges more easily than any other jDlan. And it appears to be a fact, that in the well-sewered towns in England the cholera of 1865 and 18G6 never attained any wide spread. In Munich, in the cholera epidemic of 1873, the well-sewered parts of the town had only one-half the sickness and mortality of the others, which were either im- perfectly drained or not at all. ' In large towns, also, there are no other means of disposing of the discharges. But may not sewers be a means of dissemination," and thus, as in some outbreaks of enteric fever, be a source of danger ? And again, when sewerage is poured over land, as it will be soon throughout all England, are we quite sure that no choleraic effluvia will pass off, or that the choleraic particles passing into the ground may not develop there, as Pettenkof er supposes is the case ? There are no facts to enable us to decide, but the possibility of mischief arising in this way should, at any rate, make us still more urgent in the use of disinfectants to all discharges. Again, as to disposal in the earth, if Pettenkofer is correct, that a loose moist earth is the place where the supposed germ of cholera acquires its powei', the last place we should put a choleraic discharge would be the earth ; and there would be even an argument against the use of the earth plan of deaUng with sewage. Still, as there is much to be said against Pettenkofer's views, and as in small towTis and villages there is only the al- ternative of allowing the discharges to pass mto cessj^ools or streams, or to be disposed of in the earth, it wovald seem to be the safest course to deeply bury all disinfected discharges, cai-e being taken to place them at a distance from houses and from sovu'ces of water supply. Another plan would be to mix them with sawdust and burn them. That hnen and bedding should be carefully disinfected, needs no argu- ment. In some English towns all cholera clothing has been burnt, but whether this measui'e is necessary or not is uncertain. But thorough steep- ing and boiling befoi'e washing is essential, as Avasherwomen have certainly suffered in many cases. 3. The introduction of the agent by the medium of the air is generally » Soyka, Deutsche Viertlj. f. OS. Ges., Band xiv., Heft 1, p. 54, 1883. ^ That these may be so, in a particular way, was shown to be probable in Dr. Parkes' Report on Cholera in Southampton (Sixth Report of the Medical Officer to the Privy Council, p. 251) ; but still there is very little evidence on this point. PREVENTION OF DISEASE. 137 admitted, on the plea that cases occur in wliich any other mode of entrance is impossible. It is also held by some that, existing in the aii-, it can be car- ried for great distances by winds ; and some observers indeed beheve this to be its usual mode of transit, though this opinion appears opposed to all we know of its spread. Without attempting to decide the point or to state the limits of the transmission, it is a matter of piiidence to act as if the winds did cany the poison. The Indian inile is to march at right angles to the wind, and never against it or with it if it can be avoided. The spreading by the winds in India has been usually ascribed to the custom of throwing all the cholera evacuations on the ground ; there they get di-ied, and then are lifted by the wind and driven to other parts. This seems probable, but no decided proof has been given ; and an argument against it may be raised on the difficulty of accounting for the immunity of adjacent places if such trans- mission were common. So also the use of aerial disinfectants in cholera is rendered imperative by the chance that the cause may be in the air. The use of sulphiu' fires has been advocated and tried in India, apjoarently with good effect (Crerax-). The Vienna Conference affirmed transmission by the au', but only to a short distance, and never faster than man travels. They also recognized the great safeguard aiforded by deserts, as the disease has never been known to be imported into Egypt or Spia across the desert by caravans from Mecca.' 4. The occasional, perhaps frequent, introduction by water seems cer- tain. It was unanimously affirmed at the Vienna Conference, even by Pettenkofer, who has, however, since abandoned this view. It is a good plan always to change the source of supply, to use rain-water if no other fresh soiu'ce is procurable ; and in eveiw case to boil, and filter, and to use also potassium permanganate.' It remains yet uncertain whether a water which gives cholera is always chemically impure, or whether the choleraic matter may be in so small a quantity as to be absolutely indetectable. In the two cases examined by Dr. Parkes in which the water was the cause, it was highly impure. In India it is now ordered that all the water should be boiled.^ 5. The introduction by food has been noted in some cases (although the Vienna Conference decided, by 11 to 7, that present facts do not warrant a decision). Every article of food, soUd and liquid, should therefore be passed in review, and the cooking arrangements gone over step by step.^ ' On this point the history of Chili is interesting, as cholera has never reached it. It is separated on the north from Peru bv the desert of Attacama, and from the Argen- tine Confederation on the east bv the Andes range, to Tvhich circumstances its im- munity hitherto from epidemic diseases has been ascribed by the inhabitants. - In the very able Report on Epidemic Cholera in the United States Army (Circular No. 5, War Department ; Surgeon-General's Office, Washington), is -wliat appears to be a good instance of the effect of changing the supply. At Ne\y Orleans rain, and in some cases distilled -water, was supplied instead of river water, with the apparent effect of checking the spread (p. xvii.j; see also the cases of Utrecht and Rotterdam, as re- ported by Buys-Ballot. ^ G. O. C. C, No. 192, clause 53. Forster, of Breslau (Die Verbreitung der Cholera durch die Brunnen, 1873), urges two recommendations which he thinks will prevent cholera in the future— 1st, Lead to every town, even if at great cost, abundant and pure water, as indeed was done, he says, much better 2.000 years ago than now. 2d, Protect the ground from contamination in any way from excrement, and banish all cesspits. The ground raust be absolutely pure, and this can only be if all fecal matter is removed to a distance. "* See Dr. Fairweather's Delhi case in the Sanitary Report of the Punjab for 1871 ; also given in Report on Hygiene, in the Army Medical Report, vol. xiii. (1873). 138 PRACTICAL HYGIENE. 6. The localization of cholera is a marked feature in its history.* It is often as marked as in yellow fever, and may be confined to a Teiy small ai*ea. At other times, in India, the " tainted district " may be of some ex- tent. From this fact of localization arises the important vule of always leaving the locahty when j^racticable, and in a large town of clearing out the house where cholera lias happened. In India the present itile is to march the men out and encamp ui a healthy spot at some httle distance, changing the encamping gi-ound from time to time. On the whole, tbis has acted well, and should be adhered to, though occasionally it has failed, generally, however, it would seem, from error in choice of locahty. The men should be tented ; the tents shotdd be weU ventilated, and often stinick and repitched ; an elevated spot should be chosen, and damp and low soils and river banks avoided. Orders lay down with precision the exact steps to be taken by a regiment when cholera threatens." This nile of marcbing out must, of coflrse, be subject to some exceptions. It has been adrised that it sliould not be done in the rainy season in India. Tbis must depend on the locality. It appears sometimes to have answered well, even in hea^y rains ; but in other cases the rains may be too hea%y. No absolute rule can be laid down ; but the cu'cumstances which are allowed to set aside the gi-aud rule of evacuation of a tainted jolace should be unequivocal. In connection -^-ith change of locality, the opinions of Pettenkofer should be borne in mind. Pettenkofer believes that, of all conditions, the effect of soil is the most important. It is necessary, then, to consider particu- lai'ly the nature of the soil where the fresh camps ai^e to be j^laced, and to select perfectly dry and, if possible, pvu-e, impermeable, uncontaminated soils, and to prevent the cholera discharges from percolating through the ground. 7. Men sick from cholera are also best treated in well-ventilated tents, "whenever the season admits of it. Even in cold countries, up to the end of October or the middle of November, tents can be used if properly warmed. In India it should be a nile to treat eveiy cholera patient in a tent, as far as circumstances permit it. Internal Cau.. — General feebleness of health gives no predisposition, nor is robust health a safeguard ; some even have thought that the strongest men suffer most. Great fatigue, and especially if continued from day to day, greatly predispo.ses ; of this there seems no doubt. ^ Xo certain influ- ence has yet been traced to diet, altbough it has been supposed that a vegetable diet and alkalinity of the intestinal contents may predispose. It ^ Surgeon P. Cullen (Indian Medical Gazette, July 1, 1873) notices a very singular case of localization at Etarsi. ' The order in India is, if a single case occur in a barrack, to vacate that part of the barrack, and to encamp the men in the cantonment. If a second case occur among the body of men thus removed, they are again moved, and the building or tent is vacated and purified. If a third case occur in this body of men within a week, they are re- moved to the preparatory camp. Buildings are purified by scraping and washing walls with hot caustic limewash ; boiling punkah fringes, ropes, curtains, etc., and iising chloride of lime or other disin- fectant. Tents are purified b}- being fumigated with either chlorine, nitrous acid, or sulphurous acid, and then exposed to the weather for ten days. Railway carriages, after occupation by troops carrying cholera, are purified by washing with boiling water containing in each gallon a wineglassful of carbolic acid, and burning sulpliur in the closed carriages for two hours. If troops are moved by rail, they are not to use latrines, but trenches are to be dug for them (G. O. C. C, Xo. 19y). " There are many instances of the effects of long marches. See Orton, Lorimer, and Thom, quoted in Brit, and For. Med. Chir. IUjv., July, lb48, pp. 85-87. PREVENTION OF DISEASE. 139 does not appear that insufficient diet has any great effect, tliough there is some shght evidence that scurvy increases the mortahty, and perhaps the predisposition/ The strictest temperance does not preserve from attacks ; but every one agrees that spirits are no protection, and that debauchery increases habihty. Of pre-existing diseases, it has been supposed that cardiac affections and pulmonary emphysema predispose ; the evidence is very unsatisfactory. If Bsale's observations be correct, post-mortem examinations often show pre- vious affection of the vilh and mucous membranes of the intestines generally ; but it is very desirable there should be more proof of this. Diarrhoea predisposes, and any causes which lead to diarrhoea, especially impure water, dietetic errors, etc., should be carefully looked after. With regard to prophylactic measures (except in respect to proper diet, free ventilation, and pure water) nothing has yet been made out. Quinine has been recommended, and should certainly be given, especially in malari- ous countries, as it is a fact that the choleraic poison and malaria may act together, and even give a slight periodical character to choleraic attacks, which is never seen in non-malarious districts, and is therefore merely grafted on cholera. Peppers, spices, etc., have been used ; but there is no good evidence respecting them. All diarrhoea should be immediately checked, and this is well known to be the most important point connected with the prevention of the internal causes. The universal order in India is, that any man going twice in one day to the latrine should report him- self ; and non-commissioned officers are usually stationed at the latrines to watch the men. The reason of this rule should be fuUy explained to the men. In two attacks of cholera in India, Dr, Parkes found it almost im- possible to get the men to report themselves properly ; the shght diarrhoea of early cholera is so painless that they think nothing of it.^ In England and Grermany house-to-house visitation has been found very useful.^ ' For some evidence as to scurvy, see Pearce and Staw "On the Cholera of the Jail at Calicut," Madras Medical Journal, July, 1863. ■■* Several points have been taken from Mr. Dickinson's useful little pamphlet on the Hygiene of Indian Cholera, 1.863. ^ Great importance has been attached to the meteorological condition attending out- breaks of cholera ; they do not appear to be very important, except in two or three cases. 1. Temperature. — A high temperature favors the spread by increasing the putrefac- tion of the stools, and by augmenting generally the impurity of the air. When cholera has prevailed at a low temperature (it has been severe at a temperature below freezing), the drinking-water has possibly been the cause. 2. Pressure has no effect. The old observation of Prout, that the air is heavier in cholera epidemics, has never been confirmed. 3. Moisture in ^^V. —Combined with heat, this seems an accessory cause of impor- tance, probably by aiding transmission. Moisture in the ground, combined with heat of the soil, has always been recognized as an aiding cause of great importance. 4. Dryness of Air seems decidedly to check it. 5. Rain sometimes augments, sometimes checks it. This, perhaps, depends on the amount of rain, and on whether it renders the drinking-water more or less pure. A very heavy rain is a great purifier. 6. Movement of Air. — It is certainly wotst in the stagnant atmospheres, as in the cases of all the specific poisons. 7. Electricity is not known to have any effect. This was particularly examined by Mr. Lamont in Munich, one of the most celebrated physical philosophers of our time, but with entirely negative results. 8. Ozone has no effect, either in its presence or absence (Schultze, Voltotine, De Wethe, Lamont, Strambio, Wunderlich). 140 PRACTICAL HYGIENE. Typhus Exanthematicus {Spotted Typhus). External Cause. — An auimal poison, origin unkno^Aii, but communicable from person to person, probably through the excretions of the skin and lungs floating in the air. Not known to be communicated by water or food. Its spread and its fataUty are e^identl}' connected with overcrowd- ing and debihty of body fi'om deficient food. That it can be produced by overcrowding is yet uncertain.' The preventive measures may be thus shortly summed up : Adopt isolation '" of j^atients ; use the freest ventila- tion (5,000 to 6,000 cubic feet per head per hour or more) ; evolve nitrous acid and chlorine fumes ; thoroughly fumigate with sulphurous acid, heat (to 220" Fidir), wash, and expose to arr all bedding (including mattresses) and clothes. Tliis last point is extremely impoiiant. In fact, it may be said that, for the prevention as well as ti-eatment of typhus, the cardinal measiu'es are abundance of pure air and pure water. Whenever practi- cable, treat all tv-phus patients in tents, or wooden huts with badly joined walls, not in hospitals. Fumigate tents and scrape and hmewash huts, and remove earth from time to time from the iloors. A number of typhus patients should never be aggregated ; they must be dispersed ; and if cases begin to spread in an hospital, clear the ward, and then, if the disease con- tinues, the hospital itself ; then wash with chloride of lime, and then Hme- wash or scrape walls and floors, and thoroughly fumigate with nitrous acid. It has been often shown that even exposure to weather, bad diet, and insufiicient attendance are less dangerous to the patients than the aggrega- tion of cases of t^'phus. Internal Causes. — A special condition of body is necessary, as in the case of small-pox, and one attack protects to a great extent from another. The nature of the internal condition is unknown ; but general feebleness fi'om bad diet, overwork, exhaustion, and especially the scorbutic taint, greatly increase the intensity of the disease in the individual, and perhaps aid its spread. These conditions, then, must be avoided. But the strongest and best health is no guai'antee against an attack of tj^hus. Bubo or Oriental Plague {Pali Plague in India).^ The preventive measures should be the same as in typhus, to which this disease shows gTeat analogv'. The history of the plague at Cairo (from which it has been now banished for many years, simply by improving the ' During the Frencli war of 1870, althongli there was miieh crowding, wretched- ness, and misery in Paris, and particularly in IMetz, there was but little typhus ; it was nothing like the amount in the first Napoleon's time (Grellois, Histoire Medicale du Blocus de Metz, 1872, Chaiiffard, Academie de Medecine). '^ By the term isolation is meant the placing a patient in a separate building, not in anotlier room in the same building ; in the case of small-pox, typhiis, and scarlet fever, this partial isolation, thoiigh sometimes successful, cannot be depended upon. If a room must be chosen in the same building, choose the top story, if. a room can be there found. ^ The Pali plague (Maha Murree), which was most common in Eajpootana, was evidently propagated by the filthy habits of the inhabitants (see Ranken and others), and was some years ago almost entirely got rid of by sanitary measures. Subsequently, these were neglected, and the disease returned. It has now again greatly lessened. Hirsch has pointed out that the Pali plague di.Ters from the Egyptian plague in having a marked lung disease, and in this it resembles the black death in the fourteenth cen- tury, with which Hirsch, in fact, considers it identical. PEEVENTIO]Sr OF DISEASE. 141 ventilation of the city)/ and the disappearance, after sanitaiy improve- ments, of the Pali plague in India, and its recurrence on the cessation of preventive measures, show that, like typhus, the bubo plague is easily pre- ventible. Elevation, as in so many other specific diseases, has a considerable effect ; the village of Alum Dagh, near Constantinople (1,640 feet above the sea), and freely ventilated, has never been attacked ; the elevated citadel of Cairo has generally been spared ; and when Barcelona was attacked, the elevated citadel also escaped. Typhoid or Enteric Fever, External Cause. — A poison of animal origin ; one mode of propagation is by the intestinal discharges of persons sick of the disease ; other modes of origin and transmission are not dis^Droved. There is doubtless a fre- quent transmission of the disease by the diarrhoea of mild cases which are often not diagnosed. There is some evidence that persons considered convalescent may carry the disease,^ but it is possible that this may have been owing to badly washed clothes. The mode of entrance into the body is both by air and water. Entrance by food (milk) has been lately also proved. As means of arresting the disease, isolate the patients ; receive all evacuations (fseces and ui'ine) into the vessels strictly kejDt for one sick person ; place zinc chloride, or ferrous sulphate, or carbolic acid, etc., in the vessels ; never empty any evacuation into a closet, sewer, or cesspool ; bury it several feet deep, and mix it well with earth. Fumigate, and heat to 220° Fahr., all clothes and bedding. As means of prevention, attend especially to the purity of the drinking water, and to the disposal of sew- age ; although the origin of typhoid merely from putrefying non-typhoid sewage is not considered at present to be probable, it is not disproved, and it is certain that the disease may spread by the agency of sewers and fecal decomposition. A single case of tj'phoid fever should at once be held to prove that something is wrong with the mode of getting rid of the excretions. If neither water nor sewers can be proved to be in fault, con- sider the milk and other food supply. Internal Causes. — As a first attack preserves in a great measure from a second, a peculiar condition of body is as essential as in small pox ; and looking to the special effect produced on Peyer's patches, and to the fact that at the period of hfe when these patches naturally degenerate, the suscep- tibility to typhoid fever materially lessens, or even ceases, it seems possi- ble that the internal cause or necessary second condition is the existence of these patches, the structures in which are brought into an abnormal state of activity by the direct or indirect action of the poison on them. The other internal causes are anything which causes gastro-intestinal dis- order, such as bad water, and general feebleness. Relapsing Fever. No preventive measures have been yet pointed out, but the occurrence of the disease in times of famine seems to indicate that feebleness and in- anition are necessary internal causes. ' Stamm, in Pappenheim's Beitriige, 1862-63, p. 80. The measures adopted in Cairo were levelling some hillocks, which stopped the air from blowing over the city, filling up some marshes, and adopting a better mode of burial. The peculiar sepulture cus- toms of the Copts have indeed even been assigned as the sole cause of the origin of ' igue. '' Gietl., Die Ursachen der enterischen Typhus in Miinchen, 1865, pp. 74 and 94. 142 PEACTICAL HYGIENE. BUious Remittent Fevers. Under this vagne term, a disease or diseases, whicli in many points ai'e like relapsing fever, but yet are not identical (Marston), have been described as occurring especially in Egypt (Griesinger), and in the Levant generally. It has also been described by Drs. Marston and Boileau,' at Malta. The exact causes are not known ; but in some of the T\Titings of the older army surgeons, the fevers which are produced by foul camps (in addition to tyjihoid) appear to have a close resemblance to the bilious re- mittent fevers of the Mediterranean. They appear to be connected with bad sanitary conditions, but their exact causation is not clear. Cerebro-Spinal Meningitis. This disease, which has occasionally been noticed in France, and espe- cially among soldiers, for the last half centuiy, has within late years ap- peared in several parts of Germany, and a few cases among civilians have occiuTed in England. It seems to depend on a specific agent, but vers'- little is yet known about it. It does not appear to be contagious. No preventive measures can be at present suggested. The Eruptive Fevers. Small-pox is guai'ded against in the army by repeating vaccination in the case of reciiiits, and by occasional re-vaccination of all the men in a regiment. In the statistical reports, great attention is always paid to this important point, and the evidence from foreign ai-mies proves the necessity of careful re-vaccination. If the disease does occur, isolation " (in separate buildings) is most im- portant, but the aggi'egating of a large number of cases together ought to be avoided. In the case of scarlet fever and measles, nothing definite is known with regard to prevention, except that a good sanitary condition seems to lessen their intensity, and probably their spread. The evidence with regard to belladonna in scarlet fever is contradictoiy, but on the whole unfavorable. All the discharges should be disinfected, and the skin well rubbgd over with camphorated oil and a Httle weak carbolic acid. The most difficult case is when either measles or scarlet fever appears on board ship, and especially if children are on board. If the weather permit, the best plan is then to treat all patients on the upper deck under an awning. If this cannot be done (and scarlet fever patients must not be exposed to cold), they must be isolated as much as possible. Both in scarlet fever and small-pox there is some evidence to show that the incu- bative joeriod may be very long.^ Perhaps, in the present state of evidence, it might be desirable to try the prophylactic effects of belladonna on board shijD, directly the first case occurs. ' Army Med. Reports, vols. iii. and viii. ^ Buclianan gives a good example of the advantages of isolation in the case of Chel- tenham, where small pox was introduced into the town six times, but, in consequence of proper hospital accommodation for all classes, never made good its footing. * See a case by Bryson (Trans. Soc. Science Assoc, 1802, p. 677), for a case in which the incubative period of small-pox appeared to be thirtj-oue days. lu scarlet fever it is said to be sometimes even longer. PREVENTION OF DISEASE. 143 Erysipelas {Hospital or Epidemic). External Cause. — It is well known that in the surgical wards of hos- pitals erysipelas occasionally occurs, and then may be transmitted from patient to patient. The exact causes of its appearance have not been made out, but it is evidently connected with overcrowding and impure air. Moisture of the floors, causing constant great humidity of air, has also been supposed to aid it. It is much more common in fixed hosj)itals than in tents and huts, and indeed is exceedingly rare in the two latter cases. The agencies or agent can scarcely be supposed to be other than putre- fying organic matter and pus-cells passing into and accumulating in the air, or organisms developed in connection with them. It is remarkable that pus-cells derived from purulent sputa do not cause erysipelas in medical wards, but this may be from a want of open wounds to give the necessary personal condition. When hospital erysijDelas has once apj)eared in a ward, nothing will avail except complete clearance of the ward, scraping the floors, and often the walls, washing with chloride of lime, and then with solution of caustic lime, and thorough fumigation with chlorine and nitrous acid alternately. The erysipelatous cases should be placed in well-ventilated tents. Considering the undoubted beneficial influence of tent life, it may be a question whether, even in civil life, hospitals which possess gardens should not, during the summer, treat their surgical cases with suppurating wounds in the tents.' In many continental towns the large hospitals have now wooden huts attached to them, in which the surgical cases are treated. Of course, extreme care in conservancy of wards or tents, the immediate removal of all dressings, great care in dressing wounds, so that neither by instruments, sj)onges, lint, or other ajDphances, pus-ceUs or molecular or- ganic matter shall be inoculated, are matters of familiar hospital hygiene. The use of carbolic acid and other antiseptics, as introduced by Professor Lister, wiU, it is hoped, greatly lessen the chances of spread in the case of erysipelas as well as of hospital gangrene.'^ Internal Causes. — Nothing is known on this point, except that there must be some abrasion or wound of the surface or of the passages near the surface, as the vagina or throat. The erysipelas commences at the point of abrasion. If there is no open wound, the atmospheric impurity seems to have no bad effect on the persons who are exposed to it, but it would be interesting to know if some forms of internal disease are not produced. Is it possible that some forms of tonsillitis and diphtheritic-like inflamma- tion of the throat may be caused in this way, although there is no solution of continuity ? Hospital Gangrene. Almost the same remarks apply to hospital gangrene as to erysipelas. One of the most important facts, which has been pointed out by many writers, and which has been thoroughly j)i'oved by the American and the Italian wars, is that perfectly free ventilation prevents hospital gangrene. Hammond, the late Surgeon-General of the United States Army, declares ' ' See Hammond's Hygiene, 1863; Kraus' Das Kranken und Zerstrenungs-System, 1861 ; and a Report on Hygiene, by Dr. Parkes, in the Army Medical Report for 1862, for the effects of tents on erysipelas and hospital gangrene. - T was informed, in Munich, that Lister's system has completely banished hospital gangrene from that city, and I believe the same result has been noticed in other Ger- man towns. — (F. de C.) s Hygiene, p. 897. 14 J: PRACTICAL HYGIENE. that only one instance has come to his knowledge in which hospital gan- grene has originated in a wooden pavilion hospital, and not one which has occurred in a tent. Kraus also, from the experience of the Austrians in 1859, states that it never could be discovered that gangrene originated in a tent. On the contrary cases of gangrene at once commence to impi-ove when sent from hospital wards into tents. On the other hand, the tenacity wdth which the organic matters causing the gangrene adhere to walls is well known. The measures to be adopted in wards when hospital gangrene occurs, and the ward cannot be at once evacuated, are the same as for erysipelas.' It is not necessary to do more than allude to the undoubted transference by dirty sponges, etc., and to the beneficial effects of antiseptic dressings. SECTION n. VARIOUS NON-SPECIFIC DISEASES. Dysentery and Diarrhcea. At present there is no evidence that the dysentery arising from various causes has different anatomical characters, or runs a different course, ex- cept perhaps in the case of malarious dysentery'. The chief causes are — 1. Impure Water. — Both Annesley and Twining have directed attention to this cause, in their accounts of Indian dysentery. It is scarcely possible that, with common attention, this cause should not be discovered and re- moved. 2. Impure Air. — The production of dysentery and diarrhoea from the effluvia of putrefying animal substances is an opinion as old as CuUen, and probably older ; and there seems little doubt of its correctness. The gases and vapors from sewers also will, in some persons, cause diarrhoea ; and also effluvia fi'om the foul bilge-water of ships. '^ On the other hand, very disagreeable effluvia from many animal substances, as in the case of bone- bvu'ners, fat-boilers, etc., do not seem to cause diarrhoea. In India there appears to be a decided relation between the prevalence of dysentery and overcrowding and want of ventilation in barracks ; massing a large number of men together is certainly an accessory cause of great weight.'' The air from very foul latrines has caused dysentery in nvimerous cases. Pringle, and many other army surgeons, record cases.' In war this is one of the most common causes. The occasional production of dysentery from sewage applied to land, seems to be proved by Clouston's observations on ' With regard to pyaemia, observations show that one of the external causes is fetid organic emanations. Spencer Wells (Med. Times and Gazette, 18G2) states, that in 1859 the mortality from pyaemia was great in some wards over a dissecting-room. On removing all the cases after operation to the opposite side of the building, pyaemia al- most disappeared. Other similar cases are on record. - Fonssagrives (Traite d'Hygiene Navale, p. 60) records a good case of this kind. It commenced after a gale at sea had stirred up the bilge, and on clearing it out the attack ceased. 3 Wood on the Health of European Soldiers in India, 1864, p. 45 et seq. '' Sir James M'Grigor, Vignes (who give many cases from the French experience in the Peninsula), Chomel, Copland; see also the Die. des Sciences Med., art. "Dysen- teric." D'Arcet (Ann. d'Hygiene, vol. xii., p. 390) records a good case, in which a whole regiment was affected in the Hanoverian war, from having used too long the same trench as a latrine. The disease disappeared when another was dug. PEEVENTIOJSr OF DISEASE. 145 the cause of the attack of dysentery in the Cumberland Asyhim.' Still sewage matter has been often applied in this way without bad effects. In Dr. Clouston's case the sewage was 300 yards from the ward where the dysentery occurred. Calm and nearly stagnant nights, or with a gentle movement of air from the sewage toward the ward, were the conditions which preceded most of the attacks. Of all the organic eflftuvia, those from the dysenteric stools appear to be the worst. Some evidence has been given to show that dysentery arising from a simple cause (as from exposure to cold and wet), when it takes on the gangrenous form, and the evacuations are very fetid, produces dysen- tery in those who use the latrines, or unclean closets, into which such gan- grenous evacuations- are passed. If correct, this is a most interesting point, as it seems to show the origin of a communicable poison de novo. Possi- bly, in all these cases, effluvia, or organic matters, or particles disengaged from the putrefying evacuations, act at once on the anus, and the disease then spreads up by continuity. There is some reason, also, to think that retaining dysenteric stools in hospital wards spreads the disease ; and, perhaps, in this case, the organic particles floating up may be swallowed, and then act on the mucous mem- brane of the colon. In the epidemic of dysentery in Sweden in 1859, there was good evidence to show that it spread by means of the diarrhoeal and dysenteric evacuations.^ In all cases the stools must be mixed with disin- fectants, and immediately removed from the wards and buried. 3. Improper Food. — Any excess in quantity, and many alterations in quality (especially commencing decomposition in the albuminates, and, perhaps, the rancidity of the fatty substances) cause diarrhoea, which w'ill pass into dysentery. But the most important point in this direction is the production of scorbutic dysentery, A scorbutic taint plays a far more im- portant part in the production of dysentery than is usually imagined, and there is now no doubt that the fatal dysentery, which formerly was so prevalent in the "West Indies, was of this kind. Much of the Indian dys- entery is also often scorbutic. 4. Exposure to Cold and Wet. — Exposure to cold, especially after exer- tion, and extreme variations of temperature, have been assigned as the chief cause of dysentery by numerous writers ; ' great moisture has been assigned by some writers (Twining, Annesley, Griesinger) as a cause ; and great dryness of the air by others (Mouat) ; while a third class of obser- vers have considered the amount of moisture as quite immaterial. Hirsch,* after summing up the evidence with respect to the temperature with great care, decides that sudden cold after great heat is merely a " causa occasionalis " ^ which may aid the action of the more potent cause ' Medical Times and Gazette, June, 1865. 2 British and Foreign Med. Chir. Rev., January, 1866, p. 140. ' A few only can be noted ; Stall, Zimmermann, Huxham, Durandeau, Willan, Irvine, James Johnson, Annesley, Bampfield, Morehead, Vignes, Fergusson, etc. Fer- gusson says : ' ' True dysentery is the offspring of heat and moisture ; of moist cold in any shape after excessive heat. Nothing that a man can put into him would ever give him true dysentery." ■*Handbuch der Historisch-Geograph. Pathol., Band ii., p. 234. ^ The so-called ' ' hill diarrhoea, " which was formerly prevalent on some of the liill sanitaria in India, especially on the spurs of the Himalayas, has been attributed to the effect of cold and moisture, and sudden changes of temperature. But, as remarked by Dr. Alexander Grant, many hill stations have these atmospheric conditions without having any hill diarrhcea. There is great reason to suppose the hill diarrhoea to be entirely unconnected with either elevation or climate. In some cases it has been Vol. II.— 10 146 PRACTICAL HYGIENE. of dysentery. This, probably, is the tnie readinp^ of the facts. The amount of moisture in the atmosphere would appear to be a matter of no moment. Although we cannot assign its exact causative value, the occurrence of chill is, of covu'se, as a matter of prudence, to be carefully guarded against ; and especially chills after exertion. It is when the body is profusely per- spmng, and is then exposed to cold, that dysentery is either produced, or that other causes are aided in their action. In almost all hot countries chilling of the abdomen is considered particularly hurtful, and shawls and waist-bands (kummerbund of India) are usually worn.' 5. Malaria has been assigned as another cause ; and it was noticed especially by the older wi'iters, that the dysenteiy was then often of the kind termed " Dysenteria Incruenta " — the stools being cojdIous, sei'ous, and vdth httle blood ; in fact, a state somewhat resembling cholera. Veiy gi'eat difference of opinion has prevailed in regard to this opinion.^ Possibly the " malarious dysentery " is in part connected with the use of marsh water. More evidence is desirable, certainly, with regard to this point ; but it Seems probable, from the observations of Annesley and Twining, that marsh water has an effect in this dii-ectiou. Liver Diseases {Indian). The production of diseases of the Hver is so obscure, and so many states of hepatic disorder are put together under the term " hepatitis," that it is impossible to treat this subject properly without entering fully into the question of causes. But, as this could not be done here, we must content ourselves with a short summary of the preventive measures which appear to be of the gi-eatest importance. Dr. Parkes had long been convinced that many cases of hj'peraemia, bilious congestion, and enlargement of the hver, with increase of cell- gi'owth and connective tissue (but without tendency to abscess), and en- largement and j)artial fatty degeneration of the liver-cells, are caused sim- ply by diet.' He had a good opportunity of obsein-ing this on landing in India in 1842 with an European regiment,* and his later experience made him certain that the observation was correct. clearly caused bj bad water, possibly by suspended scales of mica or by magnesian salts in the water ; in other cases, its exact causes remained unexplained. Of late years it has lessened in amount at all stations, and will probably disappear. ' It is a remarkable circumstance, that in temperate climates the most common months for dysenteric epidemics are the hot months — June to {September. Taking North America and Nortliern and Western Europe, Hirsch has assembled 546 outbreaks. Of these, 176 occurred in summer ; 228 in summer and autumn ; 107 in autumn ; only 16 in spring ; and 19 in winter. This does not look as if cold had any effect. The heat of summer is far more influential. ■■' The very varying opinions are given very fully by Hirsch. Morehead's great authority was altogether against the presumed action of malaria ; but possibly here, as in many other cases, we shall have to draw a complete distinction between malarious and non-malarious dysentery. ^In the great and admirable works of Ranald Martin and Morehead, the influence of diet in producing liver affections, though alluded to, has been passed over much too lightly. Annesley, on the other hand, has fully recognized the immense influence of diet (vol. i.. p. 192). * Remarks on the Dysentery and Hepatitis of India, by E. A. Parkes, M.B., 1846, p. 228. PREVENTION OF DISEASE. 147 Very similar opinions have been expressed by Macnamara,' and Nor- man Chevers has also pointedly alluded to this subject.^ The supply of food for the soldier in India has erred in two ways : it is too much in quantity, especially when the amount of exercise is hmited. Macnamara has calculated that each European soldier in Bengal consumed (at the time he wrote, in 1855) 76 ounces of solid (i.e., water-containing) food daily, so that there must have been an excess of all the dietetic prin- ciples. Then, in every case, there was added to this a very large amount of condiments (spices and peppers), articles of diet which are fitted for the rice and vegetable diet of the Hindu, but are particularly objectionable for Europeans. In the West Indies, where the diet has never been so rich in condiments, Hver diseases have always been comparatively infre- quent. Some orders for improving the cooking in India were issued by Lord Strathnairn, and if these were earned out, and if medical officers would thoroughly investigate the quantity of food taken by the men, and compare it with their work, and examine into the cooking, it is quite certain that many cases of dyspepsia and hejoatitis would be prevented. In cases not simply of hypersemia and bilious congestion, but of ab- scess, it is probable that a certain number are consecutive to dysentery, and are caused by the absorption of jDutrid matters from the intestine, ^ which are arrested by the liver, and there set up suppuration. There is no true pytemia or inflammation of the vena portse as a i-ule. When caused by phlebitis or special aifection of the vena porta?, the suppuration is in the course of the vena portae, or at any rate commences there. The reason why some cases of dysentery cause abscess and others do not, is uncertain. The prevention of this form of abscess is involved in the pre- vention of dysentery. In other cases of abscess, however, there is no antecedent dysentery, but there are collections of pus or fetid debris somewhere else, which act in the same way by allowing absoi'ption. There are, however, other cases in which no such causes have been pointed out, and the genesis of these cases of abscess remains quite obscure. Much effect has been attributed to the influence of sudden changes of temperature ; to the rapid supervention of an exceedingly moist and comparatively cold air on a hot season, where- by the profuse action of the skin is suddenly checked ; and to the influence of malaria. But the extraordinary disproportion of cases of abscess in dif- ferent parts of the woi'ld seems to negative all these surmises. One fact seems to come out clearly from Dr. Waring's observations, viz., that recent arrival in India is favorable to the occurrence of abscess, and that (all kinds of abscesses being put together) 50 per cent, occur in men under three years' service. No length of residence, however, confers perfect immunity. It would be very important to determine whether the efiect of recent arrival is marked, both in cases of abscess consecutive, and in those anterior, to dysentery. It is possible, also, that some entozoic influence may be at work, espe- ' Indian Annals, 1855. Dr. Macnamara found a most extraordinary amount of fatty degeneration of the liver. ^ Health of European Troops in India, Indian Annals, 1858, p. 109. It is particu- larly recommended that this chapter should be carefully perused. •^ It is, however, remarkable how many cases of dysentery occur without producing hepatic abscess ; still our general knowledge of the causation of disease makes it highly probable that dysentery acts in this way. Is it the sloughing dysentery which is fol- lowed by hepatic abscess ? 148 PRACTICAL HYGIENE. cially in some parts of Lidia, and hydatid disease of the liver or other diseases of the same class may be more common than is supposed. In the absence of perfect knowledge, great care in preserving from qhills, and j^roper diet, are the only preventive measures which can be suggested for immaiy hepatic abscess. Insolation. Under this convenient term, a number of cases are put together which seem to be produced by one or more of the following causes : — External Causes. — 1. Direct rays of the sun on the head and spine. Adopt light coverings, covered with white cotton ; permit a good current of an- between the head and the covering, and use a light muslin or cotton rag, dipped in water, over the head under the cap. 2. Heat in the shade, combined esj^ecially with stagnant and impure air. In houses (and men have been attacked with insolation both in tents and barracks) means can always be taken to move the air, and thus keep it pure, even if it cannot be cooled. In tents the heat is often exceedingly great, simply from the fact that there is not sufficient movement of air ; in the tropics a simple awning is much better than tents, and if the awning is sloped a little, the top of the slope being toward the north, the movement of air will be more rapid than if the canvas be quite flat. But in the dry season, in the tropics, the men should sleep in the open air in all non-malarious districts, when they are on the march or in campaigns. The general prophylaxis has been thus sximmed up by Professor Mac- lean :' — "Men will bear a high temperature in the open air* with compara- tive impunity, provided (a) it is not too long continued ; (b) that the dress be reasonably adapted to the temperature ; (c) that the free movement of the chest be not interfered with." Internal Causes. — It is only known that spirit drinking, even in modera- tion, powerfully aids the external causes of insolation ; even wine and beer probably have this effect. Tea and coffee, on the other hand, probably lessen the susceptibility. A full habit of body, or any tendency to fatty heart or emphysematous lungs, have been supposed also to predisj^ose. It seems certain that any embarrassment of the pvdmonaiy circrdation aids the action of the heat, and therefore the most perfect freedom from belts and tight clothes over the chest and neck is essential. Great exhaustion from fatigue aids the action, either from failure of the heart's action or w-ant of water. In this case difliisible stimuli, such as ammonia, tincture of red lavender, tinctui*e of cardamoms, etc , with strong coffee are the best preventives. Spirits should not be given, unless the ex- haustion be extreme, and the diffusible stimuli cannot be obtained. A small quantity in hot water may then be tried. Cold baths, and especially cold douching to the head and spine, are most useful as preventive as well as curative measures. Phthisis Pulmonalis. In respect of causes, we must distinguish those usually rapid cases of tuberculosis which arise from hereditary constitutional causes, or from the influence of exanthemata (especially measles), or of typhoid, or other fevers, and w^hich run their course with imphcation of several organs at an early ' Reynolds' System of Medicine, vol. ii. , p. 157. PEEVENTIOX OF DISEASE. 1^0 stage, and the more chronic forms of phthisis, in -which the lung in adults is the first seat of the disease, and other organs are secondai-ily afi'ected. Several distinct diseases are confounded under the one term of phthisis, and it is therefore not possible at present to trace out their precise origin. Taking only the common cases of subacute or chronic phtliisis, it has been already intimated that most Eui-opean armies have been found to fur- nish an undue proportion of such cases/ A few years ago much influence was ascribed to food as a cause of phthisis ; the occurrence of a sort of dyspejDsia as a forerunner (though this does not seem very common), and the great effect of the treatment by diet (by cod-hver oil), seemed to show that the fault lay in some peculiar mal- nutrition, which affected the blood, and through this the lungs. Probably there is truth in this ; but of late yeai's the effects of conditions which influence immediately the j^ulmonary circulation and the lungs them- selves have attracted much attention. The effect of want of exercise (no doubt a highly complex cause, acting on both digestion and circulation), and of impure air, have been found to be very potent agencies in causing phthisis, and conversely, the conditions of prevention and treatment which have seemed most useful are nutritious food and proportionate gi'eat exer- cise in the free and oj^en air. So important has the last condition jDroved to be, that it would appear that even considerable exposui-e to weather is better than keeping phthisical patients in close rooms, provided there be no bronchitis or tendency to pneumonia or pleurisy. Three poiats, then, are within oui* control as regards phthisis — ai'range- ment of food, exercise, and pure aii'. That food should contain a good deal of the nitrogenous and fatty principles if phthisis is apjn-ehended. Milk has been long celebrated, and lately the koumiss of Tartary has obtained a gTeat reputation in Russia as an agent of cure, and is now a good deal used (made from cow's milk) in this country. Exercise is of the gi'eatest importance, and it would seem quite clear that this must be in the open au'. The best climates for phthisis are per- haps not necessarily the ecj^uable ones, but those which permit the gi'eatest number of hours to be passed out of the house. In the house itself, attention to thorough ventilation, i.e., to constant, though imperceptible movement of the ah", is the point to be attended to. In the case of soldiers, it must also be seen that no weights or sti'aps impede the circulation of blood through the lungs and heart. The effect of a wet subsoil in the causation of phthisis must not be overlooked. Whatever may be the exact amount of truth, we are bound to act as if it were certain. That the syphihtic disease of the lungs has sometimes a com^Dletely phthisical character is tolerably clear, but syphilis -^"111 not account for the amount of phthisis in the army. The influence of masturbation in pro- ducing phthisis is uncertain. The researches of Koch, and the discovery of a supposed phthisis bacillus, have revived the notion of the commuuicabdity of the disease, an idea long held by Italian physicians. This would only be a still greater argument for the freest ventilation indoors, and for a large part of the ' There are two valuable pieces of evidence of phthisical and scrofulous disease be- ing developed in a healthy popxilation from impure air, viz . ~Slv. I\Iorgan's essav on " Phthisis on the West Coast of Scotland" (Brit, and For. Med.-Chir. Rev.), and the analogous case of Western Canada, given by Mr. Mackeleave (Medical Times and Gazette, August, ISGd). 150 PEACTICAL HYGIENE. patient's time being spent out of doors. It -would also indicate the inadvi- sability of allowing healthy individuals (especially childi-en) to sleep with or occupy the same sleeping-rooms as phthisical persons. It would also be an argument against massing phthisical persons together, although there does not seem to be any direct e\idence of injury arising from consump- tion hospitals, which are, however, always freely and carefully ventilated. Scurvy. The pecuHar state of malnutrition we call scurvy is now known not to be the consequence of general starvation, though it is doubtless greatly aided by this. Men have been fed with an amount of nitrogenous and fatty food sufficient not only to keep them in condition, but to cause them to gain weight, and yet have got scurvy. The starches also have been given in quite sufficient amount without preventing it. It seems, indeed, clear that it is to the absence of some of the constituents of the fourth dietetic group, the salts, that we must look for the cause.' Facts seem to show with certainty that in the diet which gives scurvy there is no deficiency of soda or of iron, lime, or magnesia, or of chloride of sodium. Nor is the evidence that salts of potash or phosphoric acid are deficient at all satisfactory. And w^hen we think of the quantity of jDhos- phoric acid which must have been supplied in many diets of meat, and cereaha, which yet did not prevent scurvy, it seems veiy unlikely that the absence of the phosphates can have anything to do with it.'' The same may be said of sulphur. Considering the quantity of meat and of leguminosae which some scorbutic patients have taken, it is almost impossible that deficiency in sulphur should have been the cause. By exclusion, we are led to the oj^inion that if the cause of scurvy is to be found in deficiency of salts, it must be in the salts whose acids form carbonates in the system. For, if we are right in looking to a deficiency in the fourth class of alimentary principles as the cause of scui-yj', and if neither the absence of soda, potash, lune, magnesia, iron, sulphur, or phos- phoric acid can be the cause, then the only mineral ingredients which remain are the combinations of alkalies with those acids which form car- bonates in the system, viz., lactic, citric, acetic, tartaric, and malic. That these acids are most important nutritional agents no one can doubt. The salts containing them are at first neutral, afterward alkaline, from their conversion into carbonates ; they thus play a double part, and moreover, when free, and in the presence of albumen and chloride of sodium, these acids have peculiar powers of precipitating albumen, or perhaps of setting free hydrochloric acid. Whatever may be their precise action, their value and necessity cannot be doubted. Without them, in fact, one sees no reason why there should not be a continual excess of acid in the system, ' For a good deal of evidence up to 1848, reference may be made to a review on Scurvy, contributed by Dr. Parkes to the British and Foreign Medico-Chirurgical Review in that year. The evidence since that period has added little to our knowledge, except to show tliat the preservative and curative powers of fresh meat in large quan- tities, and especially raw meat (Kane's Arctic Expedition), will not only prevent, but will cure scurvy. Kane found the raw meat of the walrus a certain cure. For the most recent evidence and much valuable information, see the Report of the Admiralty Committee on the Scurvy which occurred in the Arctic Expedition of 1875-76 (Blue Book, 1877). ■' Professor Galloway of Dublin, and Mr. Anderson of Coventry, have lately written pamy^hlets urging the claims of potash and phosphoric acid to attention, but without bringing any fresh evidence of sufficient importance to support their views. preventio:n" of disease. 151 as during nutrition a continual excess of acids (phosphoric, sulphuric, uric, hiiDpuric) is produced, sufficient, even when the salts with decom- posable acid are supplied, to render all excretions (urinary, cutaneous, intestinal) acid. The only mode of supplying alkaU to the acids formed in the body is by the action of the phosphates, which is hmited. The only manufacture of alkali in the body is the formation of ammonia, so that these salts are most important as antacids. Yet it is not solely the absence of alkali which produces scurvy, else the disease would be prevented or cured by supply of pure or carbonated alkalies, which is not the case. When, in pursuing the argument, we then inquire whether there is any proof of the deficiency of these particular acids and salts fi'om the diets which cause scurvy, we find the strongest evidence not only that this is the case, but that their addition to the diet cures scurvy with great certainty.' They will not, of course, cure coincident starvation arising from deficiency of food generally, or the low intercuiTent inflammations which occur in scurvy, or the occasionally attendant pui'pura, but the true scorbutic condition is cured with certainty. Of the five acids, it would appear rmhkely that the lactic should be the most efficacious. If so, how is it that in starch food, during the digestion of which lactic acid is probably formed in large quantities, scurvy should occur? Is, in such a case, an alkali necessary to insure the change of the acid into a carbonate ? Vinegar is an old remedy for scurvy, and acetic acid is known to be both a jDreventive of (to some extent) and a cure for scurv}^ But it has always been considered much inferior to both citric and tartaric acids. Possibly, as in the case of lactic acid, an alkali should be supplied at the same time, so as to enable the acid to be more rapidly transformed. Tartaric and (especially) citric acids, when combined with alkahes, have always been considered to be the antiscorbutic remedies, par excel- lence, and the evidence on this point seems very complete.'^ Of mahc acid little is known as an antiscorbutic agent, but it is well worthy of extended trials. Deficiency of fresh vegetables imphes deficiency in the salts of these ' This was most clearly shown in the last Arctic Expedition (1875-76). The rations on board ship during winter were ample, containing dried potatoes and other vegeta- bles, preserved vegetables, pickles, bottled fruits, vinegar, and a daily ration of lime juice, besides raisins and currants. In the sledge expeditions all these were cut off ex- cept two ounces of preserved potatoes, an inadequate ration under any circumstances. The meat was pemmican and bacon, and there was, of course, no fresh bread. The result was, that this imperfect diet, conjoined with most laborious work, produced a severe outbreak of scurvy, which nearly proved fatal to the wliole party. The rapidity with which the sick recovered, on being supplied with lime juice and more favorable diet, was noticeable (see Report, op. cit.). '■' It is based on a very wide experience, and should not be set aside by the state- ments of men who have seen only three or four cases of scurvy, often complicated, which happen not to have been benefited by lemon juice. The process of preventive medicine is checked by assertions drawn from a very limited experience, yet made with great confidence. We must remember that many cases of scurvy are complicated — that the true scorbutic condition, inanition, and low inflammation of various organs, lungs, spleen, liver, and muscles, may be all present at the same time. See paper by Dr. Ralfe, of the Seamen's Hospital (1877, reprinted from the Lancet). The Merchant Shipping Act of 1887 was soon followed by a great decrease of scurvy in our mercan- tile marine ; but since 1873 there has been a steady increase, which has been attributed by Mr. Thomas Gray (see Official Memorandum on Sea Scurvy and Food Scales, 1882) to want of more varied food scales. It may, however, have resulted from neglect of lime juice, or the use of a damaged article (see British Medical Journal, September, 1883). 152 PRACTICAL HYGIENE. acids, and scurvy ensues witli certainty on their disuse. Its occun'ence is, however, greatly aided by accessory causes, especially deficiency in food generally, by cold and wet, and mental and moral depression. The preventive measvires of scurvy are, then, the supply of the salts of citric, tartaiic, acetic, lactic, and maHc acids, and of the acids themselves, and perhaps in the order here given, and by the avoidance, if it can be done, of the other occasional causes. Experience seems to show that the supply of these acids in the juices of the fi*esh succulent vegetables and fruits, especially the potato, the cab- bage, orange, hme, and grape, is the best form. But fresh fruits, tubers, roots, and leaves are better than seeds. The legniminosse, and many other vegetables, are useless. Fresh, and especially raw meat is also useful, and this is conjectiired to be from its amount of lactic acid ; but this is uncertain. The dried vegetables are also antiscorbutic, but far less so than the fresh ; and the experience of the American war was not so favorable to them as might have been anticipated. Do the citric and other acids in the di-ied vegetables decompose by heat or by keeping? It would be very- desirable to have this question settled by a good chemist. We know that the citric acid in. lemon juice gradually decomposes. It does not follow that it should be quite stable in the dried vegetables. The measures to be adoj^ted in time of war, or in prolonged sojourn on board ship, or at stations where frasli vegetable are scarce, are — 1. The supply of fresh vegetables and fruits by aU the means in our power. Even unripe fruits are better than none, and we must i-isk a httle diarrhoea for the sake of their antiscorbutic properties. In time of war every vegetable should be used which it is safe to use, and, when made into soups, almost all are tolerably pleasant to eat. 2. The supply of the dried vegetables, ' especially potato, cabbage, and cauliflowers ; turnips, parsnips, etc., are j^erhaps less useful ; dried peas and beans are useless. As a matter of precaution, these di-ied vegetables should be issued early in a campaign, but should never supersede the fresh vegetables. 3. Good lemon juice should be issued daily (1 oz.), and it should be seen that the men take it. 4. Vinegar {k oz. to 1 oz. daily) should be issued with the rations, and used in the cooking. 5. Citrates, tartrates, lactates, and malates of potash should be issued in bulk, and used as drinks, or added to the food. Potash should be selected as the base, as there is seldom any chance of the supply of soda being lessened. The easiest mode of issuing these salts would be to have packets containing enough for one mess of twelve men, and to insti-uct the men how important it is to place them in the soups or stews. Possibly they might be mixed with the salt, and issued merely as salt. Lozenges made of citric acid or desiccated lime juice and sugar are well worth a trial * Probably dried fruits, such as raisins and currants (which contain some acid and vegetable salts) are useful as antiscorbutics. The American pemmican contains them, and men are said to live upon it for months together without suffering from scurvy. It appears to have been that kind of pemmican on which the crew of the "Polaris" lived, who drifted on an iceberg for six months. Other dried fruits, such as apples, would probably also be efficacious. PREVENTION OF DISEASE. 153 Military Ophthalmia. The term " military ophthalmia " is often appHed particularly to that disease in which the peculiar gray granulations form on the palpebral con- junctiva. But any severe form of purulent ophthalmia spreading in a regiment is often classed under the same heading. Diseases of the eyes are a source of very considerable inefficiency in the army, and even a casual visitor to the Royal Victoria Hospital must be struck by the large number of men he will meet with who have some affection of the eyes. A refer- ence to the "Army Medical Reports" will also show what great attention is being paid to this important subject by mihtary surgeons, especially by Professor Longmore. ' ' Epidemics of military ophthalmia (gray or vesicular granulations, and rapid purulent ophthalmia), seem to have been uncommon, or perhaps unknown, on the large scale in the wars of the eighteenth century. The disease, as we now see it, is one of the legacies which Napoleon left to the world. His system of making war with httle intermission, rapid movements, abandonment of the good old custom of winter quarters, and intermixture of regiments from several nations, seem to have given a great spread to the disease ; and though the subsequent years of peace have greatly lessened it. it has j^revailed more or less ever since in the French, Prussia, Austrian, Bavarian, Hanoverian, Itahan, Spanish, Belgian, Swedish, and Russian armies, as well as in our ovm.. It has also been evidently propagated among the civil population by the armies, and is one more heritage with winch glorious war has cursed the nations. Our last Egyptian campaign (1882), which was very short, does not appear to have produced much ophthalmia among the troops engaged. In some cases, as in the Danish army, it has been absent till manifestly introduced (in 1851) ; in other instances it has been supposed to originate spontaneously from overcrowding and foul barrack atmosphere, and from defective arrangements for ablution.^ Here, as in so many other cases, we find that the question of origin de novo, however important, need not be mixed up with that of the necessary preventive measures. What is im- portant for us is to know — first, that it is contagious, that is, transmissible ; and, secondly, that if not produced, its transmissibihty is singularly aided by bad barrack accommodation. The measures to be adopted if military ophthalmia prevails — 1. Good Ventilation and Purity of the .4m-.— In the Hanoverian army, Stromeyer reduced the number of cases in an extraordinary degree, simply by good ventilation. The only explanation of this must be that the dried particles of pus and epithelium, instead of accumulating in the room, were carried away, and did not lodge on the eyelids of the healthy men. The evolution of ammonia from decomposing urine has also been assigned as a cause, and this would be also lessened by good ventilation. ' Ophthalmoscopes are now issued to the different stations, and an Oplithalmoscopic Manual has been drawn up by Mr. Longmore for the use of army medical officers. As giving a good survey of military ophthalmia in the British army, the excellent papers of Dr. Frank (Army Medical Report for 1860) and Dr. Marston (Beale's Archives) should be also referred to. A very interesting paper has also been published by Mr. Welch (A.M.D., formerly 22d Regimenti, (Army Medical Report, vol. v., p. 494, 1865), on the "Causes aiding the Development of Granulations at Malta." A warm, moist, impure atmosphere is shown to have a great influence. - See Frank's papers (Army Medical Report for 1860, p. 406) for some remarks on its spontaneous origin. 15-i PRACTICAL HYGIENE. It would appear likely that bad barrack air predisposes to granidar con- junctivitis by producing some pecidiar state of the palpebral conjunctiva and glands (Stronieyer and Frank), and if a diseased person then intro- duces the specific disease, it sj^reads with great rapidity, or possibly, as 'Mi: Welch's facts seem to show, the impiU'e atmosj)here is the great cause, and contagion only secondary. 2. Careful Ablution Arrangements. — An insufficient quantity of water for cleansing basins, and the use of the same towels, are great means of spreading the disease, if it has been introduced. Whenever men use the same basins, they should be taught to thoroughly cleanse them ; and it would be well if, in every mihtary ablution room, the men were taught not only to allow the dirty water to run away, but to refill the basin with water, which the next comer would let off before filling with fresh water for hiiji- self. If some mechanism could be devised for this, it would be very useful. The same towel is a most common cause of propagation ; or a diseased man using always the same towel may reinoculate himself. The towels should be ver}' frequently washed (probably every day), and should be dried in the open air, never in the ablution room or barrack. In some cases special ablution arrangements may cause a good deal of gi-anular conjunctivitis. In 1842 and 1843 Dr. Parkes witnessed, in a regiment newly landed in India from England, a very great number of cases of this kind. The supply of water was very insufficient ; many men used the same basins, which Avere very imperfectly cleaned ; the same basins were used for washing and also for dyeing clothes ; at that time the men in the cold months wore trousers of a black drill, and when the dye came off they were accustomed to rudely replace it ; they themselves ascribed the very j:)revalent ophthalmia to the u-ritating effect of the parti- cles of the dye left in the basins and getting into the eyes. There were enormous granulations on both upper and lower lids, and the disease was believed to be communicable, but whether the affection was strictly to be classed with the vesicular granulations is not known. 3. In some cases the use of the bedding (pillows and pillow-cases), which has been used by men with gray granulations, has given the disease to others, and this has especially occurred on board transports. In time of war especially this should be looked to. If any cases of oiDlithahnia have occiu'red on board ship, all the pillows and mattresses should be washed, fumigated, and thoroughly aired and beaten. The transference has been in this case direct, particles of pus, etc., adhering to the pillow and mattresses, and then getting into the eyes of the next comers. 4. Immediately the disease j^resents itself, the men sliovdd be complete- ly isolated and allowed to have no communication with then- comrades. It has been a great question whether a Government is justified in sending soldiers home to their friends, as the disease has been thus earned into previously healthy villages. It would seem clear that the State should bear its own burdens and provide means of isolation and perfect cure, and not throw the risk on the friends and neighbors of the soldier. An important matter to remember in connection with gray granula- tions is that relapses are very frequent ; a man once affected has no safety ( Warlomont) ; simple causes of catarrh and inflammation may then rein- duce the specific gray granulations with their contagious characters ; so that a man who has once had the disease is a source of danger, and should be watched. PKEVENTION OF DISEASE. 155 Venereal Diseases in the Army. It is convenient for our purpose to put together all diseases arising from impure sexual intercourse, whether it be a simple excoriation which has been inoculated with the natural vaginal mucus or with leucorrhoeal discharges, and which may produce some inguinal swelling, and may either get well in a few days or last for several days ; or whether it be an inflam- mation of the urethra produced by specific (or non-specific? leucorrhoeal?) discharge ; or whether it be one of the forms of syphilis now diagnosed as being in all probability separate and special diseases, having particular courses and terminations. In the army men enter the hospital from all these causes, and from the remoter effects of gonorrhoea or syphilis, orchitis, gleet, stricture, bladder and kidney affection ; or syphilitic diseases of the skin, bones, eyes, and internal organs. The gross amount of inefficiency in the army is tolerably well known, but it will require a few more years before the several items of the gross amount are properly made out. This arises partly from an occasional great difficulty in the diagnosis of true infecting syphilis, and partly from a want of uniformity in nomenclature. The comparative amount of army and civil venereal diseases is not known, because we have no statistics of the civil amount. It is no doubt great. It is a question whether a large majority of the young men of the upper and middle classes do not suffer in youth from some form of venereal disease. In the lower classes it is perhaps equally common. The sequences are most serious ; neglected gleet, stricture, secondary and tertiary syphilis, are sad prices to pay for an unlawful (in some cases a momentary) gratification ; and in the army the State yearly suffers a large pecuniary loss from inefficiency and early invaliding. In campaigns the inefficiency fi'om this cause has sometimes been great enough to alarm the generals in command and to increase considerably the labor and suffer- ings of the men who are not affected. The preventive measures against venereal diseases are — 1. Continence. — The sexual passion in most men is very strong — strong enough, indeed, to lead men to defy all clangers and to risk all conse- quences. It has been supposed by some that, in early manhood, conti- nence is impossible, or, if practised, is so at the risk of other habits being formed which are more hurtful than sexual intercourse, with all its dangers. But this is surely an exaggeration ; the development of this passion can be accelerated or delayed, excited or lowered, by various measures, and continence becomes not only possible, but easy. For delaying the advent of sexual puberty and desire two plans can be suggested — absence from exciting thoughts and temptation, and the system- atic employment of muscular and mental exercise. The minds of the young are often but too soon awakened to such matters, and obscene com- panions or books have lighted up in many a youthful breast thai feu-d'enfer which is more dangerous to many a man than the shai'pest fire of the battle- field would be. Among young soldiers this is especially the case ; while, in spite of the exciting literature of the day, and of the looseness of some of the older boys at the public schools or at the universities, the moral tone of the young gentlemen of our day is better than it was some half century ago, the conversation of the classes from which the soldier is drawn is still coarse and lewd as in the middle ages. There is too close a mixture of 156 PRACTICAL HYGIENE. the sexes in the English cottages for much decency, and the young recruit does not often require the tone of the ban-ack to destroy his modesty. In fact, it is possible that, in good regiments, he will find a higher moral tone than in the factory or the harvest-field. We must ti'ust to a higher cultivation and moral training to introduce among the male youth of this nation, in all its grades, a purer moral tone. In the army, the example of the officers and their exertions in this way would do great things if we could hope that the high moral tone which happily exists in some cases could inspire all. It is not the less necessary to save the young from direct temptation. The youth of this nation are now solely tempted, for in oiu- streets prosti- tation is at every comer. Whatever may be the objection to police I'egula- tions, we have surely a right to demand that the present system of temp- tation shall be altered. It may not be easy to exclude all prostitutes, especially of the better class (whose calling is less easilj' brought home to them), from pubhc thoroughfares, but, practically, open prostitution can be recognized and made to disappear from our streets. It has been said our j)olice regulations are sufficient for this ; they have never yet proved so ; and in no European country but England is prostitution so open and so undisguised. ' In the Acts passed in 1864," 1866, and 1869, and in the Licensing Act of 1872 (Acts of the greatest importance as the first steps in an efficient legislation), authority has been now taken to prevent prostitutes fi'om as- sembling in the public-houses, and to a certain extent sources of tempta- tion have been removed. If young men can thus escape an appeal to their passions, continence is much more easy. There are times when the strictest \'ii'tue may well dread such an appeal. Human nature is but too weak, and needs eveiy safeguard it can get. As aids to continence, great physical and mental exertion are most powerful. It would seem that, during gi-eat exercise, the nervous energy is expended in that way, and erotic thoughts and propensities are less prominent ; so also with mental exercise, in perhaps a less degree. The establishment of athletic sports, gymnasia, and comfortable reading-rooms in the army, may be expected to have some influence. Temperance is a great aid to continence. In the army the intemperate men give the greatest number of cases of s^'phiUs ; and when a man gets an attack, it is not infi-equently found that he was drunk at the time. The measures which promote continence are, then — (a) The cultivation of pm-e thought and conversation among the young soldiers, by every means in our power. (b) Removing temptation. (c) Constant and agi'eeable employment, bodily and mentally ; as idle- ness is one great cause of debauchery. (d) Temperance. ' The effect of this upon the virtuous female population is very serious. Every ser- vant in London sees the fine clothes and hears of the idle luxurious lives of the women of the town, and knows that occasionally respectable marriage ends a life of vice. What a temptation to abandon the hard work and the drudgery of service for such a career, of which she sees only the bright side ! It is a temptation from which the State should save her. She should see prostitution as a degraded calling only, with its restrictions and its inconveniences. - An Act for the Prevention of Contagious Diseases at Certain Naval and Military Stations, 1864; an Act for the Better Prevention, etc., lb()6 (cited as Contagious Dis- eases Act, 18(36). PEETE^'TIOX or DISEASE. 157 2. 3Iarriage. — It is very doubtful Triiether those -wlio condemn early marriages among the working-classes, on account of improvidence, are en- tirely right in theij; argument. The moral effect of prolonged cehbacy has seldom been considered by them. Probably the early marriages are the salvation of the working youth of this country ; and in the present condi- tion of the labor mai'ket, the best tiling a working-man can do is, as early as possible, to make his home, and to secure himself both from the temp- tations and expenses of bachelorhood. In the case of the soldier the con- ditions were formerly different for different men ; the private soldier who had enhsted for long service (twelve years, and prospect of renewal) could not marry for seven years, and then only 7 per cent, could many with leave. It was difi&ctilt to avoid this, and the consecjuences were certainly most serious. Under the new system of seven years' enhstment, and pas- sage into the reserve, a soldier will not marry at all, and it is of course de- sirable he should not do so. If he enhsts at nineteen, at twenty-six he will be free ; and if kept in fuLl occupation, and as far as possible shielded from temptation, the biu'den of cehbacy ■^•ih not weigh upon him. Continence would be desirable for his health and for the welfare of his futui-e off- spring. The short ser\'ice now introduced may indeed greatly influence this matter, and certainly has removed from pressing discussion the ques- tion of marriage in the infantry of the army. 3. Precautions against the Disease. — Admitting that, in the case of a body of unmarried men, a certain amount of prostitution will go on, some- thing may be done to prevent disease by extreme cleanliness, instant ablu- tion, and by the use of zinc, alum, and u'on washes, or similar lotions, after connection, and by the constant use by prostitutes of similiar washes. It may seem an offence against morahty to speak of such things ; but we must deal with things as they are, and our object now is not to enforce morahty, but to prevent disease. The use in brothels of these measures appears to be more efficacious than any other plan. In some of the French towns the use of lotions and washings is rigorously enforced, with the effect of lessening disease considerably. 4. Detection and Cure of Diseased Men and Women. — In the case of the soldier who has medical advice at hand, it seems of the gi'eatest impor- tance to have instant medical aid at the first sign of disease. But instead of this the soldier conceals his ailment as long as possible, because he will be sent to hospital, put under stojopages, etc. A late regulation made this even more stringent, but it is now happily rescinded. The soldier should be encouraged to make immediate apphcation, and he should certainly not be punished for a fault which his superiors commit with impunity, and for which the State is in pari answerable by enforcing cehbacy. Our object is to preserve the man's health and seiwices for the State ; we shall not accomphsh this by ignoring what is a common consequence of his condi- tions of service. It has been proposed to detect and cure the disease in prostitutes. A great outciy has been raised against this prososal, which is ^ei a matter of precaution which the State is sui'ely bound to take. A woman chooses to follow a dangerous trade — as dangerous as if she stood at the comer of a street exploding gunpowder. By practising this trade she ought at once to bring herself under the law, and the State must take what ^precautions it can to prevent her doing mischief. The State cannot prevent prostitu- tion. We shall see no return to the stem old Scandinavian law which punished the prostitute with stripes and death ; but it is no more in- terference with the liberty of the subject to prevent a woman from 158 PRACTICAL HYGIENE. propagating sj'philis than it would be to prevent her propagating small- l^ox. The difficulty is to detect when she is diseased. Abroad, an elaborate system is in use for this purpose ; brothels are registered* and their inmates regularly examined. In this country such a system seems to many people too hke a recognition of the inevitableness of prostitution, and to a certain extent a sanction of it ; it is really, however, a simple matter of precavition. A custom exists which we cannot set aside ; let us ob\date its effects as best w^e may, while, at the same time, by higher culture and other efforts, we endeavor to gradually remove the custom.' A partial adoption of this plan has been commenced by the military and naval authorities in this country, and Acts have been passed (1864, 1866, and 1869) by means of which the prostitutes of certain military and naval stations are brought under supervision." The important clause in the Act for 1866 is clause 15, which provides that when an information is made on oath that a woman is a common prostitute, living within the limits of any place to which the Act applies, or having been within those hmits for the purpose of j)rostitution, a justice may issue notice to such woman, through the superintendent of police, to aj)pear for medical examination. She is then kept under continued inspection, and certified Lock hospitals are provided for her treatment if she is discovered to be ill. Clause 36 is also an important one ; it imposes a penalty of £20, or imprisonment, with or without hard labor, on any brothel-keeper or owner of a house who, having reasonable cause to know a woman to be a prostitute, and to be affected with a contagious disease, allows her to resort to the house for the purpose of prostitution. This Act came into force on October 1, 1866 ; and in some stations, as at Aldershot, it was really more than half a year after this time before it could be put into force. Since the passing of these Acts there has been a most decided decrease in the number of primary venereal sores at all the military stations under the Acts, compared with non-jDrotected stations. And this is ihe more satisfactory because the frequent movement of the troops, and the number of stations where there is no control of disease, render the working of the Acts difficult." ' Those persons who shut their eyes to the enormous prostitiition of this countrj', as of all others, or think nothing can be done because it is impossible to deal with private or " sly " prostitution, and with tlie higher grades of the calling, should remember that some movement in the interest of the unhappy girls themselves is necessary. In the low brothels in London the system is a most cruel one. A girl is at first well treated, and encouraged to fall into debt to her employer. As soon as she is fairly involved she is a slave ; there is no relief till she can make no more money, when she is cast out. Surely something should be done to save her. Possibly it might be well to try the plan of recognizing no debts from a girl to the procuress or brothel-keeper, and to also devise means lor at once giving her the means of release from her life if she desires it. Also, if such houses must exist — and who can venture to hope they will not ? — they may at least be made less indecent, quieter, and safer from theft, and even murder. At pres- ent, the system, as it exists, is a gigantic scandal to Christianity, and Jeannel's singular work has lately shown how curious a parallel there is between modern prostitution and that which dimmed the splendor, and perhaps hastened the fall, of Imperial and Pagan Home. Eighteen centuries after the death of Christ, are we still at such a point ? ■■' The military stations named in the Contagious Diseases Act in 1866 are Forts- mouth, Plymouth, and Devonport ; Woolwich, Chatham, and Sheerness ; Aldershot, Windsor, Colchester, Shornclifle, Curragh, Cork, and Queenstown. Others have since been added. Adjoining parishes are in many cases included. ' For the statistics of this question, see Army Medical Report for 1880, vol. xxii. , pp. 12-17 and ;368-371. PKEYENTIOX OF DISEASE. 159 But the following figui-es, from the "A. 3L D. Eeport" for 1880, ai-e quite coll^"iIlcing. In 1880 there were foui'teen stations under the Contagious Diseases Act, with a mean strength of -44,026 men ; putting against these all other stations not under the Act, with an average strength of 39,869 men, we haye the following ratio : — Admission per 1,000 of Strength. ^.n'r^r^nr. Gonorrhoea. • venereal bore. Foui'teen stations under the Act 1880 74 100 Ah other stations not under the Act 1880 119 114 It must be remembered that at present gonon-hcea has not been touched by the Act, for want of hospital accommodation, so that the nearly equal amount of gonoiThcea of the two classes shows th^t the enormous lessen- ing of primary venereal sore in the controlled stations is owing to a real diminution of syphilis, and not to lessened frequency of intercourse. This is proved again by the foUo^^ing figures given by Dr. Balfour. In 1864, the yeai- before the Act came into operation, the average ad- missions at all the stations from primary venereal sore were 1G8.6 per 1,000. In 1872, at the uncontroUed stations, the number was still higher, being 12.3.2, so that s;\"|:)hihs had not declined in the uncontroUed stations. But in the controlled stations in 1872 the admissions were only 53.3. Therefore, the gain to the State in the controlled stations was (108.9-53.3) 55 admissions less per 1,000 of strength ; and in a mean strength of 50,000 men the State was saved the cost of 2,750 cases of primary venereal sore in that year, and the men were saved the enormous injuiy to their health which would otherwise have resulted. Let the facts be put in another form. Taking the first seven years that the Acts were in. operation (before the introduction of the stoppage regu- lation in 1873), viz., 1865-72 (though in the early yeai'S the operation was partial and imperfect), we have the following figiii-es : Admission per 1,000 of Strength, 1865-72 inclusive. Primary Sores. Gonorrhcea AH stations not under the Act (mean strength 32,528 men) 103.1 111.7 Stations under the Act (mean strength 30,765 men) . . 62.8 115.0 There was therefore a practical identity in gonorrhceal admissions, but the annual admissions for primary venereal sores were reduced in the con- trolled stations by 40.3 per 1,000. In the eight years the State was there- fore saved very nearly 10,000 cases of syphilis ; and supposing each de- manded twenty days of treatment (which is moderate), 200,000 days of sickness have been saved in eight years. Such, then, has been the operation of the Act under many disadvan- tages, but this has not been its only beneficial effect. The Act at the large stations has done gTeat good in some other direc- tions, especially as regards the women. Many women have been reclaimed ; the horrible juvenile prostitution has almost ceased, and comparative de- cency has been taught in the hospitals. StiU. the act is too feebly drawn, and too partially canied out, to cope entu-ely with the evil. The jirosti- tutes are not thoroughly under inspection ; many are not inspected at all ; 160 PRACTICAL HYGIENE. ueighboring towns send in prostitutes ; and liospital accommodation is insufficient. The prostitutes from suiTounding districts not in the Act also come into these towns and camps, either remaining for a few days and then dis- ai3j)earing, or, if diseased, stopping tiU they can get admitted into hospital. Kegiments coming from other quarters not under the Act ; men coming from furlough or detachment, also introduce the disease ; in fact the means of evasion and of reintroduction are numerous. One consequence of the Contagious Diseases Act was to make public the most frightful state of things among the women of our garrison towns. The vivid jDicture of the Chatham prostitute's life, drawn by IVIr. Berkeley Hill,' was no exaggeration. Eejjorts from the Lock hospitals at other places would, if ixiblished, have borne out all Mr. HiU alleged. Shocking as these disclosures are, and mortifying as they may be to our national pride, it is by far the best plan to have them made. An evil like tliis must not be treated in the shade ; it will never be overcome till the public know its proportions ; the deadly mists which cling round and poison the very basis of society can be dispersed only when the healing light of the sun falls on them. It is at any rate encouraging to learn that the effect of the Act has been greatly to improve the manners and habits of the women — to impose some restraint on them, and to restore to them something that, in compari- son with their former life, may be called decency. ' British Medical Journal, 18G7. CHAPTER XIX. DISINFECTION AND DEODORIZATION. The term disinfectant, which has now come into popular use, has unfor- tunately been employed in several senses. By some it is applied to every agent which can remove imp uiity from the air ; ' by others, to any sub- stance which, besides acting as an air purifier, can also modify chemical action, or restrain putrefaction in any substance, the efflmia from which may contaminate the au- ; while, by a thii-d party, it is used only to desig- nate the substances which can prevent infectious diseases from spreading, by destroj-ing theh' specific jDoisons. This last sense is the most coiTect, and it is that which is solely used here. The term disinfectant might also be ajDphed to substances destroying entozoa or ectozoa, or epiphytes or ento- phytes, but there is a disadvantage in gi's'ing it so extended a meaning. The mode in which the poisons are destroyed, whether it be by oxidation, deoxidation, or arrest of growth, is a matter of indifference, pro%*ided the destruction of the poison is accomplished. The general term air imrifier is given in this work to those agents which in any way cleanse the air, and which therefore include disinfectants ; and the term sewage deodorants, to those substances which are used to prevent putrefaction in excreta, or in waste animal or vegetable matters, or to remove the products of putrefac- tion. In a great mauy instances the substances which are recommended as disinfectants are little more than deodorants, and ought properly to be spoken of as such. The chief human diseases which are supposed to spread by means of special agencies (conveniently designated vmder the name of " contagia"),^ are, the exanthemata ; typhus exanthematicus ; enteric (typhoid) fever ; re- lapsing fever ; yellow fever ; paroxysmal and the allied remittent fevers ; dengue ; cholera ; bubo-plague ; influenza ; whooping-cough ; diphtheria ; erysipelas ; dysentery (in some cases) ; puerperal fever ; s^-j^hilis ; gonor- rhoea ; glanders ; farcy ; malignant pustule ; and, perhaps, phthisis. There are some few others more uncommon than the above. It has long been a belief that the spread of the infectious diseases might be prevented by destroying the agencies in some way, and vai'ious fumiga- tions, fires, and similar plans have been employed for centui'ies during great epidemics. In oi'der to ajoply disinfection in the modern sense of the teiTu, we ought to know — 1st, the nature of these contagious agencies ; 2d, the media ^ Tardieu, for example, Diet. d'Hyg., art. "Desinfection," and many other authors. ^ It will be seen that the old distinctions between infectious and contagious diseases, and between miasmata and contaf,ia, are not adhered to. They were at no time thor- oughly definite, and are now better abandoned. Vol. II. -11 162 PRACTICAL HYGIENE. tkrougli which they spread ; and 3d, the effect produced upon them by the chemical methods which are supposed to destroy or modify them. 1. THE NATURE OF THE CONTAGIA.' This point is at present the object of eager inquiry. In the case of one or two of the above diseases, the question has been narrowed to a small compass. In variolous and vaccine discharge, and in glanders, tlie poison certainly exists in the form of solid particles, which can be seen by high powers as glistening points of extreme minuteness.^ In cattle plague blood-serum there are also excessively small particles discovered by Beale, which are probably the poison. The size of the particles supijosed to be contagia is minute ; some of them are not more than -^u^^ooth of an inch, and Beale believes that there may be smaller still to be discovered with higher powers. Cliauveau has washed the vaccine solid particles in water ; the water did not become capable of giving the disease ; the washed par- ticles retained their power. The epidermic scales of scarlet fever and the pellicle of the diphtheric membrane certainly contain the respective poi- sons, and after exposure to the air for weeks, and consequent drying, still retain their jjotency. It is more likely that solid matters should thus re- main unchanged than liquids, but it has not yet been proved that this is so, and at present the exact physical condition of the contagia of the other infectious diseases remains doubtful. The extraordinary power of increase, and capability of producing their like, jiossessed by some of the contagia when placed luider special foster- ing cii'cumstances, as in the bodies of susceptible animals, lead to the belief that they are endowed with an indejDenclent life. The old doctrines that they are simply either poisonous gases or animal substances in a state of chemical change, and capable of communicating this change, or that, like the so-called ferments (ptyalin, pancreatin, diastase, emulsin), they split up certain bodies they meet, are not now in favor. The retention of the power of contagion for some time, and its final loss, the destruction of the power by antiseptics which do not affect the action of such bodies as ptyalin or diastase, and the peculiar incubative period which is most easily explained by supposing a gradual development of the active agent in the body, are more in accordance with the h;^'pothe- sis of independent life and power of growth. The independent living nature of the contagia is a belief which has long been held in various forms. At the present time there are three views, each of which has some arguments in its favor. (1) The particles are supposed to be of animal origin, born in, and only growing in the body ; they are, in fact, minute portions of bioplasm (to use Dr. Beale 's phrase), or protoplasm.^ This is the old doctrine of " fomites " expressed in a scientific form, and supported by a fact which was not known until recently. This is that the independent life ascribed to these particles of bioplasm is no assump- ' See Report on Hygiene for 1872 (Army Medical Department Report, vol. xiii.). ^ The observations of Chauveau, Beale, and Bnrdon-Sanderson, and still more re- cently, of Braidwood and Vacher, prove tliis very important point by wliat seems in- disputable evidence. It does not follow that all small bodies are in such fluids the contugm, but the experiments prove that some of them must be. In many kinds of blood there are numerous small particles, derived, according to Riess, from retrograde metamorphosis of white blood-cells and which have no contagious property. ^ This view has been advocated with great force by Beale (Disease Germs, 2d edi- tion) ; and Morris (The Germ Tlieory of Disease, 2d edition). DTSIlSrFECTIOlSr AND DEODORIZATION. 163 tion, since we are now aware that many of the small animal-cells or bio- plastic molecules are virtually independent organisms, having movements, and apparently searching for food, growing, and djdng. This view explains singularly well the fact of the frequent want of power of the contagia of one animal to affect another family ; as, for example, the non -transference of many human diseases to brutes, and the reverse. It also partly explains the non-recurrence of the disease in the same animal by supposing an exhaustion of a special limited supply of food, which can- not be restored, since it may be supposed that some particular bodily structure is altogether destroyed, as, for example, Peyer's patches may be in enteric fever. One objection to this view is, on the other hand, that living animal particles die with great rapidity after exit from the body, while the contagia do certainly last for some considerable time.' (2) The particles have been conjectured to be of fungoid nature, and to simply grow in the body after being introduced ab externo. This view is supported by the peculiarities of the rapid and enormous growth of fungi, by their penetrative powers and splitting-up action on both starchy, fatty, and albuminoid substances, and by the way in which certain diseases of men and animals ^ are undoubtedly caused by them. It is clearly a view which would explain many phenomena of the contagious diseases, and has been supported by the experimental evidence of Hallier and many others, who have believed either that they have invariably identified special fungi in some of these diseases, or that they have succeeded in cultivating fungi from particles of contagia. At the present time, however, the evidence of true, recognizable and special y^J SoLDIEPu" In Time of Peace, receives — bread, 31 oz. avoir. ; meat (without bone), Q.& ; suet, 0.6; flour (or vegetables in heui, 2.5; salt, 0.6. To this are added a httle garhc, onions, and vinegar. These give about — Albumi- nates. Fat. Carbo- hydrates. Salts. VTater-free Food. In time of peace In time of vrar " (mean) .... 3.7 4.5 1.6 3.2 17.0 22.8 1.0 1.0 23.3 31.5 The amount of the peace ration is much the same as our own ; there is too great a preponderance of bread, and there is too great sameness. The fat is in too small a quantity ; the nitrogenous substances are too small. In Time of War. — It is difficult to calculate the daily ration, as there is a weekly issue of many substances ; the above figui'es are a mean taken from those cited by Meinert. On four days, fresh pork is issued ; the total amount being 26 oz., or 6-i- oz. daily. On one day, 6 oz. of salt jDork ; on one day, 6 oz. of beef ; and on one day, 6 oz. of smoked bacon ; altogether in the week, 44 oz. of meat ai-e issued ; and in addition, 1 oz. of butter or fat. There are also issued per week : — 24^ oz. of biscuit, 147 oz. of flour for bread, 29^- oz. of flour for cooking, 54- oz. of pickled cabbage (soui' kraut), 9 oz. of potatoes, 5^ oz. of peas, and 5 oz. of barley. Wine, brandy, and beer are also given. KUSSIAN SOLDIEE.^ There are 196 meat days and 169 fast days in the year. On the meat days meat is given -wdih. schtschi (cabbage soup) and buckwheat gTuel ; on the fad days the meat is replaced by peas and (occasionally) fish. 42 oz. avoir, of rye bread ai'e issued daily. This is large, but it is probably watery. Meinert * calculates the nutrition value as follows, oz. avoir. : — Albnminates. Fat. Carbo-hydrates. Salts. Water-free Food. 5.8 1.0 25.0 2.5 34.3 On the march, If ft) of biscuit (244- Enghsh oz.) instead of bread. Brandy only on rare occasions, calculated at 135 fluid ounces per year (in 5 oz. rations). ' Kraus, quoted by Rotli. ^ Meinert, Annee mid Volks-Ernaliniug, Berlin, 1880. ^ For details of tMs diet, see Dr. Oscar Hevfelder's The Russian Camp at Krasnoe Selo, German edition, 1868, or former editions of the present work, or Roth, and Lex, op. cit. ■* Op. cit. 234 PRACTICAL HYGIENE. Sepoy Diet. — Dr. Goodwin has calculated the diet of a Hindu, such as a Sepoy servant, to consist of 4.387 oz. of albuminates; 1.278 oz. of fat; 18.584 oz. of cai'bo-hydrates ; and .64 oz. of salts — total water-free food, 25.113 oz. It is thus a really better diet than that of the Eui'opean soldier. The principal ai'ticles were 24 oz. of attar (ground wheat), 4 oz. of dhoLl (pea), and 1 oz. of ghee (butter). In other cases rice is more or less sub- stituted for wheat. The Hindu diet consists of wheat, or of some of the millets (cholum, ragee, cumboo — see Millets), rice, leguminosse {Cajanus indicus), with green vegetables, oil, and spices. If any kind of diet of this soi-t has to be calculated, it can be readily done by means of the analysis of the usual foods previously given. For examjDle, a Hindu prisoner at labor in Bengal receives, under Dr. Mouat's dietaiy/ the following diet during his working days : — Total oz. Water, oz. Album, oz. Fat. oz. starches, oz. Salt, oz. Water- free Food. Rice DhoU (a pea, Cajanus indtrus). . . Vegetables (reckoned as cabbage). . Oil 20 4.25 6.0 0.33 0.33 0.33 2 0.6 5.3 1 0.9 0.1 0.16 0.08 0.03 0.33 16.64 2.75 0.34 0.10 0.12 0.04 0.33 17.9 3.3 0.5 0.3 Salt 0.3 Spices Total 31.24 7.9 2.0 0.60 19.83 0.59 22 4 In some Bengal prisons, 2 ounces of fish or flesh appear to be also given. In the Looshai expedition the Sepoys received — rice, 1 ft ; flour, 1 ft ; ghee, 2 oz. ; salt, 1.5 oz." The nutritive vahie, if the ghee is calculated as butter, is 178 gi-ains of nitrogen and 6,080 of carbon, Avhich, though deficient in nitrogen, would appear to be a good diet in respect of carbon. Probably some peas were added. SECTION m. THE CLOTHING OF THE SOLDIER. The structure and examination of fabrics have been ah'eady given. Regulations. — No specific instinictions ai-e laid down in the "Medical Regulations " respecting clothing, but the spii-it of the general sanitary- iniles necessarily includes this subject also. "When an ai-my takes the field, the Du'ector-General is dii-ected to issue a code for the giiidance of medical officers, in which clothing is specially mentioned ; and the sanitaiy officer with the force is ordered to give advice in wTiting to the commander of the forces, on the subject of clothing among other things. ' See Mouat's elaborate report On the Diet of Bengal Prisoners, Government Return, 1860, p. 49. Tbe cliittack is reckoned as the bazaar chittack, viz., = .1283 Iti, or about 2 ounces avoir. Some useful information on prison and coolie diets will be found in a memorandum prepared by Surg. -Major I. B. Lyon, F.C.S., Chemical Examiner to the Government at Bombay, May, 1877. * Indian Med. Gazette, March 1, 1872. COTSTDITIONS OF SERVICE. 235 Formerly a certain sum, intended to pay for the clothing of the men, was allotted by Government to the colonels of regiments. This was a relic of the old system by which regiments were raised, viz., by permitting cer- tain persons to enhst men, and assigning to them a sum of money for all expenses. The colonel employed a contractor to find the clothes, and re- ceived from him the surplus of the money after all paym'ents had been made. A discretionary power rested with the service officers of the regi- ment, who could reject improper and insufficient clothing, and thus the in- terests of the soldier were in part protected. ' The system was evidently radically bad in principle, and since the Crimean war, the Government has gradually taken this department into its own hands, and a large establish- ment has been formed at Pimlico, where the clothing for the army is now prepared. This system has worked extremely well ; the materials have been both better and cheaj)er, and important improvements have been and are still being introduced into the make of the garments, which cannot fail to increase the comfort and efficiency of the soldier. At the Pimhco depot the gTeatest care is taken to test all the materials and the making up of the articles ; the viewers are skilled persons, who are beheved to be in no way under the influence of contractors. In Januarj^, 1865, a warrant was issued containing the regulations for the clothing of the army, and several other warrants and circulars have since been promulgated. They are now consolidated in the " Regulations for the Supply of Clothing and Necessaries to the Regular Forces," 1881 (vol. ii., " Revised Army Regulations "). When a soldier enters the army he is suppHed with his kit ; some arti- cles are subsequently supphed by Government, others he makes good him- self. In the infantry of the line a careful soldier can keep his kit in good order at a cost of about £1 per annum. The following are the articles of the kit suppUed to the infantry recruit : — Clothing. 2 Frocks. 2 Pairs ankleboots (one each half 2 Pairs of trousers. year). 1 Forage ca p and badge. Necessaries. 2 Flannel shirts.' 1 Sponge, pipeclay. 3 Pairs socks (worsted). 1 Razor and case. 1 Pair braces. 1 Hold-aU. 1 Pair mitts. 1 Tin of blacking. 1 Hair comb. 1 Blacking brush. 1 Knife (table). 1 Brass brush. 1 Fork. 1 Cloth brush. 1 Spoon. 1 PoHshing brush. 1 Mess tin and cover. 1 Shaving brush. 2 Towels. 1 Button brass. 1 Piece of soap. 1 Kit bag. ' But this safeguard was not sufficient. Officers are not judges of excellence of cloth ; for this it requires special training. As Eobert Jackson said sixty years ago : " Soldiers' clothing is inspected and approved by less competent judges than those who purchase for themselves." ^ By a Circular, November, 1865, flannel shirts only are ordered to be supplied to the recruit. 236 PRACTICAL HYGIENE. The kit is divided ' into the svirplus and the service kit. The former, consisting of 1 frock, 1 pair of socks, 1 shirt, 1 towel, 2 brushes, and such articles for the hold-all as are not wanted, is carried for the men. The service kit is supposed to be can*ied by the man, either on his person or in his knapsack. Certain articles are also issued fi-ee of expense at stated inteis-als. For the particulars of these reference must be made to the " Regulations," 1881, •where they are stated in detail. The following are the ax'ticles issued to the line infantry soldier at home :—r- One helmet and bag Quadrennially. One tunic Biennially. One frock Annually. One pair tweed trousers Annually. One pair tweed trousers Biennially. Two pairs of boots, one on 1st April and one on ) . ,, 1st October j ^^^^^^^^y- One forage cap Annually. One silk sash for sergeants Biennially. One worsted sash for sergeants Biennially. One great-coat Everj' five years. In India and the West Indies, and other Tropical Stations, light clothing of different kinds is used — diill trousers and caHco jackets, or in India complete suits of the khakee, a native gray or dust-colored cloth, or tunica of red serge, and very light cloth. The khakee is said not to wash well, and white drill is superseding it. The English dress is worn on certain occasions, or in certain stations. Formerly the home equipment was worn even in the south of India ; but now the dress is much better arranged, and also differences of costume for different places and different times of the year are being introduced. During Campaigns extra clothing is issued according to circumstances. In the Crimea the extra clothing was as follows for each man : — 2 Jersey frocks. 2 Woollen drawers. 2 Pairs woollen socks. 2 Fail's woollen mitts. 1 Cholera belt. 1 Fur cap. 1 Tweed luied coat. 1 Comforter. To each regiment also a number of sheepskin coats was allowed for sentries. The " Regulations " of 1881 order the following articles of clothing to be issued to each man proceeding on active service in cold, temperate, or hot climates : — - 1. In Cold Climates. Sheepskin coats (for 100 men) . . Fui* caps (per man) . . Woollen comforters, " Jerseys, blue " Boots, knee, brown leather, pair Stockings, woollen, pau's 8 ! Drawers, flannel (per man) pairs . . 2 1 Cholera belts, flannel, pairs 2 1 IVIittens, hned with lambskin or 1 ftu", pair 1 1 Pilot coat, each mounted man .... 1 2 Queen's Regulations, 1881, section 13, par. 47. CONDITIONS OF SEEVICE. 237 2. In temperate climates. Cholera belts, vrhen not included Waterproof capes (for 100 men) . . 10 in the voyage kit 2 ^ Watch coats " . . 3 3. In tropical climaies. White helmet (per man) 1 Frock coat, of serge or tartan, when not supplied as ordinary clothing of these climates 1 Cholera belts, of flannel, when not part of the sea kit 2 Capes, waterproof (for 100 men) 10 For India, a drill frock, drill trousers, and a white cap cover are issued. SECTION IV. AETIGLES OF CLOTHIXG. 1. Underclothing, viz., vests, drawers, shirts, stockings, flannel belts, etc. The soldier, as a rule, weai's as underclothing only a shii't and socks. He is obhged to have in his kit two shirts. There has been much discus- sion as to the resjDective merits of cotton and flannel. Almost all medi- cal ofiicers prefer the latter, but its cost, weight, difficulty of clean- ing, and shiinking in washing, have been objections to its general adoption. General vSir A. Herbert solved the diificulty by issuing a shiii: which is partly wool, partly cotton ; it is hghter and cheaper than wool, as durable as cot- ton, and does not shrink in washing. It is of soft even texture, and weighs 19 ounces. Under the microscope, Dr. Parkes counted from 45 to 47 per cent, of wool In time of war, shirts may be partially cleaned in this way : The soldier should wear one and carry one ; every night he should change ; hang up the one he takes off to dry, and in the morning beat it out and shake it thoroughly. In this way much dirt is got rid of. He should then carry this shii't in his pack during the day, and substitute it for the other at night. If in addition gi'eat cai'e is taken to have washing pai'ades as often as possible, the difficulty of cleaning would be avoided. For hot countries, the common Enghsh flannels are much too thick and irritating ; flannel must be exceedingly fine, or what is perhaps better, merino hosiery, which contains from 20 to 50 per cent, of cotton, could be used. The best writers on the hygiene of the tropics (Chevers, Jeffi-eys, Moore) have all recommended flannel. The soldier wears no drawers, but in reahty it is just as imjoortant to cover the legs, thighs, and hips with flannel as the upper pai't of the body. Drawers folding well over the abdomen fonn, vrith the long shirt, a double fold of flannel over that important pai't, and the necessity of cholera belts or kummerbunds is avoided. Cholera belts are made of flannel, and fold twice over the abdomen. The soldiers' socks are of worsted ; they should be well shrunken before being fitted on. It has been proposed to divide the toes, but this seems an unnecessai'y refinement. It has been also proposed to do away with stock- ings altogether, but with the system of weaiiug shoes, it is ditficult to keejD the feet perfectly clean. The boots get impregnated -^ith persjm'ation. Some of the German ti'oops, instead of stockings, fold pieces of caheo across 238 PEACTICAL HYGIENE. the foot when marching ; when carefully done, this is comfortable, but not really better than a good sock kept clean. 2. Outer Garments. — The clothes worn by the different arms of the ser- vice and by different regiments in the same branch, are so numerous and diverse, that it is impossible to describe them. In many cases taste, or parade, or fantasy simj^ly, has dictated the shajDe or the material. And diversities of this kind are especially noticeable in times of jDcace. When war comes with its rude touch, everything which is not useful disappears. What can be easiest borne, what gives the most comfort and the greatest protection, is soon found out. The arts of the tailor and the orders of the martinet are alike disregarded, and men instinctively return to what is at the same time most simple and most useful. It will be admitted that the soldier intended for war should be always dressed as if he were to be called upon the next moment to take the field. Everj'thing should be as simple and effective as possible ; utility, comfort, durability, and facihty of repair, are the principles which should reg-ulate all else. The di'ess should never be encumbered by a single ornament, or embarrassed by a single contriv- ance which has not its use. Elegant it may be, and should be, for the use- ful does not exclude, indeed often implies, the beautiful, but to the eye of the soldier it can be beautiful only when it is effective. ' Head-Dress. — The head-dress is used for protection against cold, wet, heat, and hght. It must be comfortable ; as light as is consistent with durabihty ; not press on the head, and not to be too close to the hair ; it should permit some movement of aii' over the head, and therefore openings, not admitting rain, must be made ; it should present as little surface as possible to the wind, so that in rapid movements it may meet the least amount of resistance. In some cases it must be rendered strong for de- fence ; but the conditions of modern war are rendeiing this less necessary. As it is of great importance to reduce aU the dress of the soldier to the smallest weight and bulk, it seems desirable to give only one head-dress, instead of two, as at present. Remembering the conditions of his Hfe, his exposure and his night-work, the soldier's head-dress should be adaj^ted for sleeping in as well as for common day-work. Another point was brought into notice by the Crimean war ; in all articles of clothing, it much facili- tates production, lessens expense, and aids distribution, if the different articles of clothing for an army ai'e as much alike as possible ; even for the infantry, it was found difficult to keep up the proper distribution of the different insignia of regiments. Head-Dress of the Infantry. — Tlie present head-dresses are the bear-skin caps for the Guards, a smaller and rather lower kind of seal-skin for Fusi- liers, the Highland bonnets and shakoes for the Highland Eegiments, and helmets for the Artillery, Engineers, and Line, and forage caps for aU. The bear-skin weighs 37 ounces ; the Lifantry helmet, made of cork and cloth, 14^ ounces. It is for the professional soldier to decide if the rapid move- ments and the necessity of cover in modern war are compatible with the retention of the bear-skin. If not, no one would wish to retain it on san- itaiy grounds ; it is heavy, hot, gives little shelter from rain, and opposes a large surface to the wind. The Glengarry Scotch cap, now adopted as the forage cap of the army, is very soft and comfortable, presses nowhere on the head, has sufficient height above the hair, and can be ventilated by openings if desired ; it ' La tenue, dans laquelle le militaire est pret a marcher a Tennemi, est toujours belle. — Vaidy. C0XDITI0X3 OF SERVICE. 239 cannot be blown, off ; it can be canied at the top of the head when desired in hot weather, or pulled down completely over the forehead and ears in cold. Unfortunately, either to save cloth or from some idea of smartness, it is now being made so small that its advantages are imperilled, as it can- not be drawn do^vn over the head. Head-Dress of the Cavalry. — The Horse Artillery and Cayalry carry hel- mets and caps of different kinds. The shape of the helmet in the Guards and heavy dragoons is excellent. It is not top-heavy ; offers httle surface to the wind ; and has sufficient but not excessive height above the head. The material, however, is objec- tionable. The metal intended for defence makes the helmet veiw hot and heavy ; and the helmet of the Cavalry of the Guard weighs 55 ounces avou'. ; that of the Dragoon Guards, 39 ounces (in 1868). But as every ounce of unnecessary weight is additional unnecessary work thi-own on the man and his horse, it is very questionable whether more is not lost than is gained by the great weight caused by the metal Leather is now often sub- stituted in some armies, where the cavahy helmets are being made ex- tremely Ught The Lancer cap weighs 34^ ounces ; the Hussar, 29f ounces. Both are dresses of fantasy. The Lancer cap, except for its weight, is the better of the two ; is more comfortable ; shades the eyes ; throws off' the rain bet- ter ; and offers less resistance to moving air than the Hussar cap. In Canada, a fur cap is used, with flaps for the ears and sides of the face and neck. In India, many contrivances have been used. Up to the year 1842 lit- tle attention seems to have been paid to the head-dress of the infantry, and the men commonly wore their Eui'opean forage caps. In 1842 Lord Hardinge issued an order, that white cotton covers shoiild be worn over all cap)S ; subsequently, a flap to fall down over the back of the neck was added. The effect of the cotton cover is to reduce the temperatiu'e of the air in the cap about 4' to 7° Fahr. Although a great improvement, it is not sufficient. Bamboo wicker helmets, covered with cotton and provided with pugger- ies, are now used ; they are light (13 oz,), durable, not easily put out of shape, and cheap. The rim is inchned, so as to protect from the level rays of the sun. The pith, or "Sola" hats, appear to be decidedly inferior to the wicker helmets ; and men have had sunstroke while wearing them. In the French infantry the shako is now made of leather and paste- board, and is divested of all unnecessary ornament, so as to be as light as it can be. It comes well back on the head, being prolonged, as it were, over the occipital protuberance. In Algeria, the Zouaves, Spahis, and Tirailleui's wear the red fez, covered with a turban of cotton. In Cochin-China, the French have adopted the bamboo wicker helmet of the English. The natui-al hair of the head is a very gi'eat protection against heat. Various customs prevail in the East. Some nations shave the head, and wear a large turban ; others, like the Burmese, wear the hah* long, twist it into a knot at the top of the head, and face the sun with scarcely any tur- ban. The Chinaman's tail is a mere mark of conc[uest. The European in India generally has the hair cut short, on account of cleanliness and dust. A small wet handkerchief, or piece of calico, caiTied in a cap with good ventilation, may be used with advantage ; and especially in a hot land-wind cools the head greatly. Coat, Tunic, Shell-Jacket, etc. — The varieties of the coat are numer- 240 PRACTICAL HYGIEXE. ous in the army ; and there are undress and stable suits of different kinds. The infantiy now wear the tunic, which is a great improvement over the old cutaway coatee. It is still, however, too tight, and made too scanty over the hips and across the abdomen. A good tunic should have a low collar-, and be loose round the neck. The stock is now abolished, a tongue of leather being substituted where the collar of the tunic is hooked in front. The tunic should also be loose over the shoulders (so as to allow the deltoid and latissimus the most unrestricted play),' and across the chest. It should come well across the abdomen, so as to guard it completely from cold and rain ; descending loosely over the hips, it should fall as low over the thighs as is consistent with kneeling in rifle practice, i.e., as low as it can fall without touching the ground. Looking not only to the comfort of the soldier, but to the work and force requii-ed of him, it is a great mis- take to have the tunic otherwise than exceedingly loose. A loose tunic, a blouse in fact, is in reality a more soldier-like dress than the tight gar- ment, which every one sees must press upon and hinder the rajDid action of muscles. The tunic should be well provided with pockets, not only behind, but on the sides and in front ; the pockets being internal, and made of a very strong lining. In time of war, a soldier has many things to caiTy ; food, extra ammunition sometimes, all sorts of little comforts, which pack away easily in pockets. If the appearance is objected to, they need not be used in time of peace ; but -^ith a loose dress, they would not be seen. A great improvement was made by General Herbert. The old shell- jacket was done away with, and a loose frock substituted. In India the tunic is made loose, and of thin material Waistcoats. — No waistcoats are worn in the British army, but they ought to be introduced.^ A long waistcoat v\"ith a»-ms is one of the most useful of garments ; it can be used ^rithout the tunic when the men are in ban*acks or on common drill. Put on under the tunic, it is one of the best protec- tions against cold. At j^resent the men are obliged to wear tight coats, and having nothing under them, line them with flannel and wadding. In win- ter and summer they often wear the same dress, although the oppression in the summer is very gTeat. If the tunic were made very loose of some light material, and if a good short Jersey or Guernsey frock were allowed to be worn at the option of the men, the men would have cool dresses in summer, warm in winter, and the thin tunic would be more comfortable in the MediteiTanean and subtropical stations. Trousers. — Formerly the army wore breeches and leggings ; but shorily before or during the Peninsular war trousers were introduced. The in- creased comfort to the soldier is said to have been remarkable ; the trou- ser, indeed, protecting the leg quite down to the ankle, seems to be as good a dress as can be derised, if it is made on pi'oper principles, viz., very loose over the hips and knees, and gathered in at the ankle, so that merely suf- ficient opening is left to pass the foot through. The much-laughed-at peg- top trousers seem to be, in fact, the proper shape. In this way the whole leg is protected, and the increased weight given by the part of the trousers below the knee is a matter of no consequence. The trousers are supported either by braces or a belt. If the latter be used, it should be part of the trousers, should fit just over the hip, and ' This cannot occnr if epanlets are worn ; and it is to be hoped nothing will ever occur to bring in again the use of the so-called ornaments. ■•' A waistcoat was introduced some time ago, but has since been unfortunately with- drawn aaain. CO^'DITIOXS OF SERVICE. 241 not go rouBcl tlie vraist. It must be tiglit, and lias one disadvantage, vrhich. is that in great exertion the perspiration flowing do'wn from above collects there, as the tight belt hinders its descent ; also, if heavy articles are car- ried in the pocket, the weight may be too great for the belt. Braces seem, on the whole, the best. Trousers should be made with large pockets, on the principle of giving the men as much convenience as possible of carrying articles in time of war. In India, trousers are made in the same fashion as at home, but of drill or khakee cloth, or thin serge — an excellent material, especially for the northern stations. Leggings and Gedters. — Formerly long leggings reaching over the knees, and made of half -tanned leather, were used. They appear not to have been considered comfortable, and were discarded about sixty yeai's ago. Short gaiters were subsequently used for some time, but were iiually given up, and for several years nothing of the kind was worn. After the Crimean war Lord Herbert introduced for the infantr\^ short leather leggings, 6 inches in height, and buttoning on the outside. These were not of good length or shape, and have now been superseded by leggings which come more up to the knee, and are much more serviceable. In some of the French regiments a gaiter of half-dressed hide comes up to just below the knee ; short calico or linen gaiters are worn by other corps ; a flap comes forward over the instep. The calico gaiters have been much praised, but they soon get saturated with perspu'ation, thickened in ridges, and sometimes irritate the skin. On the other hand, leather gaiters, if not made of good leather, lose their suppleness, and press on the ankles and instep. A great advantage of gaiters and leggings is, that at the end of a march they can be at once removed and cleaned ; but, on the whole, if suitable leather could be fixed at the bottom of trousers, they might perhaps be abandoned. Shoes and Boots. — In the action of walking the foot expands in length and breadth ; in length often as much as ^th, in breadth even more. In choosing shoes this must be attended to. The shoemaker measures when the person is sitting, and as a rale allows only g^^th increase for walking. Ankle boots, weighing 40 to 42 ounces, are now worn by the infantry : the cavahy have Wellingtons and jackboots. The jackboots of the Life Guards weigh (with spurs) 100 ounces avoir. Shoes cannot be worn without gaiters. Ankle boots are preferable ; in the Enghsh army they are now made to lace, and are fitted with a good tongue. Great attention is now paid at Pimlico to the shape and make of the boot, and the principles laid down by Camper, Meyer, and others, are carefully attended to. There are eight sizes of length and four of breadth, making thirty-two sizes in all. The boots are made right and left. The heel is made very low and broad, so that the weight is not thrown on the toes, the gastrocnemii and solei can act, which they cannot do well with a high heel, and there is a good base for the column which forms the line from the centre of gravity, and the centre of gravity is kept low ; the inner hne of the boot is made straight, so as not to push outwai'd the great toe in the least degree, and there is a bulging over the root of the great toe to allow easy play for the large joint. Across the tread and toes the foot is made very broad, so that the lateral expansion may not be impeded ; the toes are broad. Great care is taken in the inspection of the boots, the order of inspection being — 1st, The proof of the size, which is done by standard measui^e ; 2d, The excel- YoL. II.— 16 242 PRACTICAL HYGIENE. lence of the leather, which is judged of by inspection of each l)Oot, and by selecting a certain number from each lot furnished by a conti-actor, and cutting them up ; if anything wrong is found, the whole lot is rejected ; 3d, The goodness of the sewing ; there must be a certain number of stitches per inch (not less than eight for the upper leathers), a certain thickness of thread, and the thread must be well waxed. The giving uj:) of boots is generally owing to the shoemaker using a large awl, and thin un- waxed thread, with as few stitches as possible ; the work is thus easier to him, but the thread soon rots. The Germans are now introducing a long boot, with a sht down the centre ; it can be worn under the trousers, or at pleasure outside, as the slit opens, and can then be laced. A someAvhat similar boot was invented by the late Major Sir W. Palliser. Considering the great injury inflicted on the foot by tight and ill-made boots, by which the toes are often distorted and made to override, and the great toe is even dislocated and ankylosed, it is plain that the increased attention lately excited on this point is not unnecessary. The compression of children's feet by the tight leather shoes now made is extremely cruel and injurious. It may, indeed, be asserted that the child's foot would be better if left altogether unclothed, and certainly we see no feet so well modelled as the children of the poor, who run about shoeless. In the case of the soldier, too, who has in many campaigns been left shoeless, and has greatly suffered therefrom, it is a question whether he should not be trained to go barefooted. The feet soon get hard and callous to blows, and clean- liness is really promoted by having the feet uncovered, and by the frequent washings the practice renders necessary. After being unworn for some time, shoes that previously fitted will be found too small, on account of the greater expansion of the foot, and this is itself an argument against the shoe as commonly worn. The sandal in all hot countries is much better than the shoe, and there is no reason why it should not be used in India for the English soldiers as it is by the native ; the foot is cooler, and will be more frequently washed. For all native troops, negroes, etc., the sandal should be used, and the boot altogether avoided. In campaigns it is most important to have large stores of boots at various points, so that fresh boots may be frequently issued, and worn ones sent back for repair. Soldiers ought to be trained to rejjair their owa boots. ' Great-coat and Cloak. — In the cavalry, cloaks, with capes which can be detached, are carried. They are large, so as to cover a good deal of the horse, and are made of good cloth ; the weight is about 5 lb to 6 lb for the cloak, and 2^ lb to 3 ft for the cape. The infantry wear great-coats weigh- ing from 5 ft to 6 ft." They are now made of extremely good cloth, are double-breasted, and are as long as can be managed. They are not provided with pockets at the back, which is a serious omission, and they also should have loops, so that the flaps may be turned back if desired. ' It may be worth while to give a receipt for making boots impermeable to wet. Dr.Parkes tried the following, and foiind it effectual : Take half a pound of shoemaker's dubbing, half a pint of linseed oil, half a pint of solution of india-rubber (price 8s. per gallon). Dissolve with gentle heat (it is very inflammable), and rub on the boots. This will last for five or six months ; but it is well to renew it every three months. At a small expense the boots of a whole regiment could be thus made impermeable to wet. Army Circular, clause 66, 1875, directs— (1) That boots are to be blackened with three coats of ordinary blacking, instead of other substances. ■ The following are the exact weights of three— one large size, one medium, and one small ; the weights were 6 ft 3 ounces, 5 ft 9 ounces, and 5 ft 8 ounces. CONDITIONS OE SEKVICE. 243 They are too heavy, aud absorb a great deal of wet, so that they dry slowly. General Eyre's Committee on Equipments recommended a lighter great- coat, and in addition a good waterproof cape. The suggestion seems to be a very good one. ' A hood might also be added with advantage. In countries with cold winds they are a great comfort. Or the Russian bash- lik might be introduced ; it is a most useful covering for cold and windy countries. The great-coat is perhaps the most important article of dress for the soldier. With a good great-coat, Robert Jackson thought it might be possible to do away with the blanket in war, and if india-rubber sheets were used this is perhaps possible. In the Italian war of 1859, the French troops left their tunics at home, and campaigned in their great-coats, which were w^orn open on the march. ^ In countries hable to great vicissitudes of temperature, and to sudden cold winds, as the hilly parts of Greece, Turkey, Afghanistan, etc., a loose, warm cloak, which can be worn open or folded, is used by the in- habitants, and should be imitated in campaigns. It is worthy of remark, that in most of these countries, though the sun may be extremely hot, the clothes are very warm. In very cold countries, sheep-skin and buffalo-hide coats, especially the former, are very useful. No wind can blow through them ; in the coldest night of their rigorous winter the Anatolian shepherds lie out in their sheepskin coat and hood without injury, though unprotected men are frozen to death. In Bulgaria, the Crimea, and other countries exposed to the pitiless winds from Siberia, and the steppes of Tartary, nothing can be better than coats like these. ^ SECTION V. WEIGHTS OF THE ARTICLES OF DRESS AND OF THE ACCOUTREMENTS, AND ON THE MODES OF CARRYING THE WEIGHTS. The following tables give the weights of all the articles used by a Heavy Cavalry Regiment, an Hussar Regiment, and the Infantry of the Line. The weights canied by the Artillery are much the same as those of the Cavalry. The weights of the helmets and jackboots of the Life and Horse Guards have been already mentioned. The cuirass weighs 10 ib 12 oz. ; it rests a little on the sacrum and hip, and in that way is more easily borne by the man. With these exceptions, the weights may be con- sidered nearly the same as those of the heavy dragoons. The uniform and equipment of the Guards and Cavalry are at present under consideration, and may be changed. ' Para. 47, sect, viii., Regulations for Clothing, directs the issue of a waterproof coat, leggings, wrappers, sou'wester caps, etc., for certain duties. ^ Cloth may be made waterproof by the following simple plan: — Make a weak solu- tion of glue, and while it is hot add alum in the proportion of one ounce to two quarts; as soon as the alum is dissolved, and while the solution is hot, brush it well over the surface of the cloth, and then dry. It is said that the addition of two drachms of sul- phate of copper is an improvement. ^ Sheep-skin bags with the wool inside were much used by the French, troops dur- ing the defence of Paris, in the winter of 1870-71. 244 PRACTICAL HYGIE:NE. Cavalry. The weight of the accoutrements and equipment is in great part car- ried by the horse. The cloak, when not worn, is carried in a roll over the shoulder, or sometimes round the neck, or in front on the horse. Private in Qth Dragoon Guards. — Weights in Marching Order {January, 1872). Articles. lb. oz. Carbine 6 8 Sword-belt and sword 5 8 Pouch-belt and pouch 1 8 Cloak and cajDe 10 8 Valise comj^letely packed ... 15 Saddle complete 47 8 Sheepskin, corn-sack, and [ q q nose-bag \ Man's clothing (which in-^ eludes a complete set of underclothing, helmet without plume, tunics, )■ VI pants, haversack, gaunt- lets, knee-boots, and sj^urs) Articles. lb. Blanket 4 Heel Eopes 1 " Pegs 2 Shackles Collar Shank Wellington boots and spurs . 2 oz. 4 8 2 10 13 10 123 15 Average weight of man) ^n-i r> (naked) f Total.... 284 15 Or 20 stone and 5 fib (nearly). Weights of Mens Clothes, No. Articles. 1 Tunic 1 Busby, plume, and lines. 1 Pair leather overalls and \ straps f 1 Pair cloth do. do 1 Stable-jacket 1 Forage-cap 1 Valise 1 Cloak, 5 lb 8| oz. ; cape, ) 2 lb 6 oz \ 1 Pair boots 1 " sjDurs 1 " highlows 1 Stable-bag 1 Pair braces 1 Batton-brush 1 Cloth " 1 Hair " 1 Brass " 1 Lace " 1 Shaving " 2 Shoe brushes 1 Tin blacking 1 Hair-comb Necessaries, etc., IQth Royal Hussars (1869).' R). oz. 3 1 13f 3 6 2 ^ 1 l^ 5 2 7 7 14i 3 Oi 5i 3 8 6 3f H 3^ 2f 2f 1 H 7^ ^ Oi No. Articles. lb. 2 Pau's drawers, each 13f oz. 1 2 Pairs gloves, each 7^ oz. . Or, 2 Pairs cotton socks, ) each sock 1\ oz. . \ 4 Brass paste IHold-aU 1 Horse-rubber 0. 1 Knife, fork, and spoon 1 Pipeclay and sponge 1 Razor 8 Shii-ts, each 14^ oz. . 2 1 Button brass 1 Stock 2 Towels, 7f oz. each . 1 Stable trousers 1 2 Flannel jackets, each 11 oz 1 Oil tin 1 Pair foot -straps .... 1 Mess-tin and strap . . 1 1 Account-book oz. 144- 4 11 ^ 2 ^ Hi If H 15i 5 6 2i Oi H 45 3^ * Since this date, the only change is the substitution of long hoots for booted over- alls ; but it is uncertain if this change will be permanent. CONDITIONS OF SERVICE. 245 Weights of Saddlery, 10th Royal Hussars. Articles. Tb. Saddle-tree 6 " seat 1 Pair flaps 2 " panels 4 Gii-tb-tub Girth-leathers 1 Stirrup-irons - 1 " leathers 1 Crupper Breastplate 1 Surcingle Set of baggage-straps .... " cloak-straps Pair waUets 1 Pair shoe-cases and straps . 1 4 horse-shoes and nails ... 4 New carbine bucket 2 Bridle-bit and head-stall . . 2 Bridoon-bit and reins .... 1 Curb-chain Bit-reins Head-collar 1 Collar-chain •. 1 Sheepskin 4 Shabraque 4 Numnah 2 5i Hi ^ 4i 15 9i 14i 4 9 m 2 2 3f 4 ^ lU Articles. ft. Corn-sack 1 Nose-bag 1 Horse-brush Curry-comb Sponge Hoof-picker Scissors Horse-log 1 Haversack Carbine 6 Pouch-belt, 11^ oz Pouch 11^ oz 20 rounds ammunition, 32J oz Wrist-belt, etc., 1 Sb 1 oz. Sabretash and slings, 1 lb 5^ oz Sword, 4 ft) 10 oz 76 IH H 11 11 2 If 9 9 7# Weight of equipments, 121 11^ Total weight of Hussar' ] 259 6^ with aU his equipments. , f or 18|^ st. Infantry. The articles of the infantry soldiers' kit have been already noted. The kit is divided into the service and the surplus kit, the latter being always carried for, and not by, the man. The service kit consists of the clothes he wears, and of some dupHcate articles and other necessaries. These articles consist of one flannel shirt (19 ounces), pair of socks (5 oz.), pair of trousers (23 or 32 oz., according to kind), pair of boots (42 oz.), towel (8 oz.), hold-all, and knife, fork, and spoon (2|- oz.), 2 brushes (6 oz.), tin of blacking (6^ oz.), forage cap (4 oz.). The following table gives a fairly correct statement of the weights of the kit and equipment : — ' Average weight and height of the men in these two cavalry regiments — Height. Weight (naked). ft. in. lb. oz. 6th Dragoon Guards 5 9^ 161 lOthHussars , 5 7i 137 11 246 PRACTICAL HYGIENE. Average weight. It). oz. Weight of clothes on person, including helmet, -winter trousers, and leggings '. 10 Personal necessaries, viz., service kit in valise 7 3 Great-coat 5 8 Valise equipment for carrying necessaiies, great-coat, and arma- ment, viz., valise, two pouches, ball-bag, suspenders, waist- belt, frog, coat-sti-aps 5 10 Havei"sack 8 Canteen 1 9 Armament, viz., rifle and sling (91b 8 oz.), bayonet (1 ft), ammu- nition (60 rounds, 6 ft weight = 1 ft for 10 rounds neaiiy) . . 16 8 Water-bottle (new pattern) and water 2 9 49 7 In war, food and a blanket would be also carried, adding from 6 to 8 ft to the weight. By omitting 40 rovmds of ammunition and one pouch, the weight of the peace equipment is lessened to 40 ft ; and if the canteen were only canned when it ■w-ns wanted, the weight would be under 39 ft. If the great-coat with the cape could be reduced to 5 ft, and the summer trousers and the boots were left out of the valise, the weight would be reduced below 35 ft, and stiU the soldier would have really everything necessary for his comfori. Some- experienced officera, however, consider it essential that the second pail* of boots should be always cai'ried by the soldier. No doubt a man should have a second pair of boots, and there may be circumstances in periods of peace when he might desire to have them with him ; but surely there is no necessity for him to caiTy, as he does now, even if he only goes on guard on a fine day, a pair of boots which he never puts on. It might be left to his discretion to carry his extra boots, and it is pretty certain he will take them when they add to liis comfort. So also with the second pair of trousei-s ; why should they be constantly caii-ied when they are scai'cely ever wanted ? In time of war, it is most important to have the soldier as little weighted as possible. The long and rapid marches which have so often decided wars have never been made by heavily laden men. The health also suffers. It is of national importance that the soldier should be as healthy and as effi- cient as possible, as the fate of a nation may be staked on the prowess of its army. The hne which the weight of his necessaries should not exceed should be drawn with the utmost care ; if his health suffers more by carrying some extra pounds of weight than it benefits by the comfort the articles give, why load him to his certain loss ? The overdoing the necessaiies of the soldier has always been a fault in our ai-my ; Robert Jackson noticed it seventy yeai*s ago. "It is a mistake," he says, " to multiply the ecjuip- ment of the soldier with a view of adding to his comfort." There are certain articles of material comfort to a man on service in a cold or wet countiw, and some altei-ation in the present arrangement would be desu-able. Dr. Parkes jji-oposed some slight changes. The gi'eat-coat, blanket, and a watei-jDroof sheet (or portion of a shelter tent), to keep both the coat and blanks and the man himself dry, are articles of the utmost imjDortance ; there is scarcely anything that a soldier might not dispense with cooner than these. But theu- weight is considerable, and it is neces- CONDITIONS OF SEE VICE. 247 sary to sacrifice some thing else to secure them. The second paii- of trou- sers is clearly unnecessary, and if he started with a thoroughly good pair of boots made waterproof, as can be easily done, and had a cheap loose shoe which he might put on after a fatiguing march, and if proper trans- port were provided for due renewal, the second joair of boots might be left out. A spare shirt, towel, socks, comb, a small hold-aU, and a clasp-knife and spoon, would comprise all that would be necessary, in addition to his haversack, water-bottle, and provisions. The forage cap with waterproof cover should be substituted for the shako. If such a plan were followed the weight of such a war equipment would be as follows : — ' R). avoir, oz. Clothes on person 10 Service kit in vahse, viz., shirt (19 oz.), towel (8 oz.), soap (2 oz.), 1 comb (|- oz.), hold-all (3 oz.), socks (5 oz.), shoes (16 oz.) . 3 1 Great-coat 4 Waterproof sheet (with appliances for tentage) 4 Blanket 4 Haversack and three days' provisions 6 . Water-bottle and 20 fl. oz. of water 2 2 Canteen 1 9 Valise equipment 5 10 Armament (with sixty rounds) 16 8 56 14 On ordinary occasions in war, as he would only carry one day's provisions and 40 rounds of ammunition, the weight would only be 52 ft). While he would be more comfortably provided, he would be less weighted than with the present system, and would be able, if it were required, to carry en- trenching tools. The vahse equipment proposed by General Eyre's Committee, and now adopted for the army, possesses gTeat facihties for carrying these articles, as wiU be presently noticed. This committee also recommended that, instead of the squad-bag for 25 men, each man shall have a separate canvas bag for his sui-plus kit, as is now provided on board ship. In time of joeace this would be carried for him, as the squad-bag is at present ; in time of war it would be left at home. It is of great moment to give each man a bag for surplus kit to himseh. It encourages the men to take care of then- things, and enables them to pack them comfortably. Each man is now supphed with a kit-bag. It may be interesting to give the weights of the various articles carried by the infantry soldier of the French, Prussian, and Kussian armies. ' The weight of the clothing, equipment, and kit of the Army Hospital Corps is as follows: — B). oz. Clothes on the person, including helmet and leggings 10 9 Great-coat and cape 5 18 Extra kit and small articles 8 2 Valise with straps, belt, mess-tin, haversack, and black bag 8 1 Water-bottle (new pattern) with water 2 9 Field companion, complete. ... , 9 13 Water-bottle for ditto, with water. . - 5 12 Total 50 11 248 PEACTICAL KYGIENE. Equipment of the French Infantry Soldier {3forache, 1874). A- Clothixg, etc. Articles. Shako Great-coat Epavilettes Shii't Neckcloth Braces Trousei-s Drawers Shoes Leather gaiters Pocket handkerchief . Knife Spoon Weight ill ft oz. avoir. 15i 6i 6-1 Of 2i 2^ 8f 10 1 15^ llf 2A Total clothing, etc . 1 12 4f n. In pack : — 2 Shii'ts Pair drawers Pau's linen gaiters . . Night-cap Pocket handkerchief. Pah- shoes Pail" trousers Hold-all complete 2 Pairs gloves 8 Packets cartridges . . Small book Jersey Tunic Forage-cap Small bag Weipht in ft avoir. 2 U 10 5i B. Equipment axd Aema^ient. Eifle (pattern of 1866) ' . . . 8 Strap for do Cartridge pouch, ) Belt and accessories, >•.... 4 Sword-bayonet, ) 2 Loose cartridges 2 Packets of cartridges in pouch 1 12f H iif TTT. Camp-equipage : — Tent (now omitted) . Accessories Blanket Cooking-pot Mess-tin Water-bottle, empty Total equipment 15 3-^ C. Pack. 5 [ rV. Four days' provisions, but only two days' of salt meat or bacon' . . Total. L Knapsack, empty 5 7 Grand total 72 The German infantry soldier carries the following weights : — ^ Clothing on the person (with gloves), not including helmet ... 10 Ai-mament and equipment (including helmet, water-bottle (fuU), coffee-miU, and trenching tools) 31 Pack, with extra kit, etc., and reserve ammunition 19 Great-coat and straps 5 Rations 7 Total 74 IS. -■■4 91 ^T lof 8f 10^ 3 1 li H 15^ 4 5f 2 12^ 1 3f 3 8^ 3 3 14 13f n 45 Oi 5 11 H 134r Some of the articles are not always carried by the same man, such as the hatchet, spade, and cofifee-mill, so that the weight may be lessened to ' This has been recently altered to the Gras rifle, but apparently without change of weight. '' To this must be added for water in the water-bottle, 2 ft 3J oz. and at least 1 lb 2 oz. if the tent be damp, making a total of nearly 76 lb, but the t4 PRACTICAL HYGIENE. In marching long distances, the extent of the marches, the halting grounds, etc., are fixed by the Quartermaster-General's department. Occasionally the march has been divided, one part being done in the early morning, and the remainder late in the afternoon. It is, however, better to make the march continuous, and, if necessary, to lengthen the mid-day halt. Order of March. — Whenever possible, it seems desirable to march in open order. Inspector-General J. R. Taylor has given evidence to show that a close order of ranks is a cause of uuhealthiness in marching, similar to that of overcrowding in barracks ; and the Medical Board of Bengal, in accordance with this ojDinion, recommended that military movements in close order should be as little practised as possible. There should also be as much interval as can be allowed between bodies of ti'oops. Effects of Marches. — Under ordinary conditions, both in cold and hot countries, men are healthy on the march. But marches are sometimes hurtful — 1st. When a single long and heavy march is undertaken when the men are overloaded, without food, and joerhaps without water. The men fall out, and the road becomes strewed with stragglers. Sometimes the loss of life has been great. The prevention of these catastrophes is easy. Place the soldier as much as possible in the position of the professional pedestrian ; let his clothes and accoutrements be adapted to his work ; supply him with water and proper food, and exclude spirits ; if unusual or rapid exertion is de- manded, the weights must be still more hghtened. When a soldier falls out on the march he will be found partially faint- ing, with cold moist extremities, a profuse sweat everywhere ; the jjulse is very quick and weak — often irregular ; the respiration often sighing. The weights should be removed, clothes loosened, the man laid on the ground, cold Avater dashed on the face, and water given to drink in small quantities. If the syncope is very alarming, brandy must be used as the only way of keeping the heart acting, but a large quantity is dangerous. If it can be obtained, weak hot brandy and water is the best under these circumstan- ces. When he has recovered, the man must not march — he should be carried in a wagon, and in a few minutes have something to eat, but not much at a time. Concentrated beef-tea mixed with wine is a powerful restorative, just as it is to wounded men on the field. 2d. When the marches which singly are not too long, are prolonged over many days or weeks without due rest. With proper halts men will march easily from 500 to 1,000 miles, or even farthei*, or from 12 to 16 miles per diem, and be all the better for it ; but after the second or third week, there must be one halt in the week besides Sunday. If not, the work begins to tell on the men ; they get out of condition, the muscles get soft, appetite declines, and there may be even a little anaemia. The same effects are produced with a much less quantity of work, if the food is insufficient. Bad food and insufficient rest are then the great causes of this condition of body. In such a state of body malarious fevers are intensified, and in India attacks'of cholera are more frequent. It has been supposed that the body is overladen with the products of metamorphosis, which cannot be oxidized fast enough to be removed. Directly the least trace of loss of condition begins to be perceived in the more weakly men (who are the tests in tliis case), the surgeon should advise the additional halt, if military exigencies permit. On the halt day CONDITIONS OF SERVICE. 265 the men should Trash themselves and their clothes, and parade, but should not di'ill. 3d. "When special circumstances produce diseases. Exposure to -^et and cold in temperate climates is the great foe of the soldier. As long as he is marching, no gxeat harm results ; and if at night he can have diy and warm lodgings, he can bear, when seasoned, gTeat exposure. But if he is exposed at night as well as day, and in war he often is so, and never gets dry, the hardiest men will suffer. Affections arising from cold, such as catarrhs, rheumatism, pulmonaiy inflammation, and dysentery ai'e caused. These are incidental to the soldier's life, and can never be altogether avoided. But one gT.eat boon can be given to him ; a wateiin'oof sheet, which can cover him both day and night, has been found the greatest com- fort by those who have tried it. The soldier may have to march thi'OiTgh malarious regions. The march should then be at mid-day in cold regions, in the afternoon in hot. The early morning marches of the tropics should be given up for the time ; the deadhest time for the malaria is at and soon after sumise. If a special- ly deadly narrow district has to be got thi'ough, such as a Terai, at the foot of hills, a single long march should be ordered ; a thoroughly good meal, -uith wine, should be taken before starting, and if it can be done, a dose of c^uinine. If the troops must halt a night in such a district, every man should take five grains of quinine. Tents should be pitched in accordance with the rules laid down in the chapter on Ca3j:ps, and the men should not leave them till the sun is well up in the heavens. Yellow fever or cholera may break out. The rules in both cases are the same. At once leave the line of march ; take a short march at right angles to the wind ; separate the sick men, and place the hospital tent to leewai-d ; let every evacuation and vomited matter be at once buiied and covered with earth, or burnt, if possible, and employ natives (if in India) to do this constantly, with a sergeant to superintend. Let eveiy duty-man who goes twice to the rear in six houi's report himseK, and, if the disease be cholera, distribute piUs of acetate of lead and opium to aU the non- commissioned officers. Du'ectly a man who becomes choleraic has used a latrine, either abandon it, or cover it with earth and lime if it can be pro- cured. If there is carbolic acid or chloride of zinc, or lime or sulphate of iron or zinc at hand, add some to every stool or vomit. In two days, whether the cholera has stopped or not, move two miles ; take care in the old camp to cover or bum everything, so that it may not prove a focus of disease for others. The diinking water should be con- stantly looked to. A regiment should never follow one which carries cholera ; it should avoid to\\-ns where cholera prevails ; if it itself carries cholera, the men should not be allowed to enter tovras. Many instances are known in India where cholera was in this way introduced into a town. The men may suffer from insolation. This will generally be imder three conditions. Excessive solar heat in men unaccustomed to it and wrongly di'essed, as in the case of the 98th in the first China war, when the men having first landed from a six months' voyage, and being buttoned up and wearing stocks, fell in numbers duiing the first short march. A friend who followed with the rearguard informed Dr. Parkes that the nien feU on their faces as if struck by lightning ; on running up and turning them over, he found many of them already dead. They had, no doubt, struggled on to the last moment. This seems to be intense asphyxia, with sudden failure of the heart-action, and is the "cardiac variety" of Morehead. 266 PRACTICAL HYGIENE. A dress to allow perfectly free respiration (freedom from pressure on chest and neck), and protection of the head and spine from the sun, -will generally prevent this form. The head-dress may be wetted from time to time ; a piece of wet paper in the crown of the cap is useful. When the attack has occurred, cold affusion, artificial respiration, ammonia, and hot bi-andy and water to act on the heart, seem the best measm-es. Bleeding is hiu'tful ; perhaps fatal. Cold affusion must not be pushed to excess. In a second form the men are exposed to continued heat,' both in the sun and out of it, day and night, and the atmosphere is still, and perhaps moist, so that evaporation is lessened, or the air is vitiated. If much exer- tion is taken, the freest perspiration is then necessary to keep down the heat of the body ; if any thing checks this, and the skin gets diy, a certain amount of pyrexia occurs ; the pulse rises ; the head aches ; the eyes get congested ; there is a frequent desire to micturate (Longmore), and gradu- al or sudden coma, with perhaps convulsions and stertor, comes on, even sometimes when a man is l3'ing quiet in his tent. The causes of the inter- ruption to perspu-ation are not known ; it may be that the skin is acted upon in some way by the heat, and from being over-stimvilated, at last be- comes inactive. Li this form cold affusion, ice to the head, and ice taken by the mouth, are the best remedies ; perhaps even ice water by the rectum might be tried. Stimulants are hurtful. The exact pathology of this form of inso- lation is uncertain. It is the cerebro-sj)inal variety of Morehead. In a third form a man is exposed to a hot land-wind ; perhaps, as many have been, from Ijiug drunk without cover. "When brought in, there is generally complete coma with dilated pupDs, and a very darkly flushed face. After death the most striking point is the enormous congestion of the lungs, which is also marked, though less so, in the other varieties. Dr. Parkes stated that he had never seen anything like the enormous congestion he had observed in two or three cases of this kind. As prevention of all forms, the following points should be attended to : — Suitable clothing ; plenty of cold drinking water (Crawford) ; ventilation ; production in buildings of currents of air ; bathing ; avoidance of spirits ; lessening of exertion demanded from the men. Duty of Medical Officers during Marches. General Duties on Marches in India or the Colonies. — Before commencing the mai'ch, order all men with sore feet to report themselves. See that all the men have their proper kits, neither more nor less. Every man should be provided with a water-bottle to hold not less than a pint. Inspect halt- ing-grounds, if possible ; see that they are perfectly clean, and that every- thing is ready for the men. In India, on some of the trunk roads there are regular halting-grounds set apari. The conservancy of these shoidd be very carefully looked to, else they become nothing but foci for disseminat- ing disease. If there are no such places, halting-grounds are selected. It should be a rule never to occupy an encamping ground previously used by another coi-ps if it can be avoided ; this applies to all cases. Select a posi- tion to windward of such an old camp, and keep as far as possible from it. The encampments of the transport department, elephants, camels, bullock I The heat of sandy plains is the worst, probably, from the great absorption of heat and the continued radiation. The heat of the san, per se, is not so bad ; on board ship sun-stroke is uncommon. CONDITIONS OF SERVICE. 267 carts, etc., must be looked, to, — they often are very dirty ; keep tliem to leeward of the camp, Bot too near, and see especially that there is no chance of their contaminating streams supplying drinking water. If the encamp- ment is on the banks of the stream, the proper place for the native camp and bazaar will always be lower down the stream. The junior medical officer, if he can be spared, should be sent forward for this purpose with a combatant officer. Advise on length of marches, halts, etc., and draw up a set of plain rules to be promulgated by the commanding officer, directing the men how to manage on the march if exposed to great heat or cold, or to long-continued exertion, how to purify water, clean their clothes, etc. If the march is to last some time, and if halts are made for two or three days at a time, write a set of instructions for ventilating and cleaning tents, regulation of latrines, etc. Special Duties for the March itself. — Inspect the breakfast or morning refreshment ; see that the men get their coffee, etc. On no account allow a morning di'am, either in malarious regions or elsewhere. Inspect the water-casks, and see them properly placed, so that the men may be sup- plied ; inspect some of the men, to see that the water-bottles are full. March in rear of the regiment so as to pick up all the men that fall out, and order men who cannot march to be earned in wagons, dhoohes, etc., or to be relieved of their j)acks, etc. If there are two medical officers, the senior should be in rear ; if a regiment marches indirisions, the senior is ordered to be with the last. When men are ordered either to be carried or to have their packs carried, tickets should be given specifying the length of time they are to be carried. These tickets should be prepared before the march, so that nothing has to be done but to fill in the man's name, and the length he is to be carried. Special orders should be given that, at the halt, or at the end of the day's march, the heated men should not uncover themselves. They should take off their pack and belts, but keep on the clothes, and, if very hot, should put on then* great-coats. The reason of this (viz., the great danger of chill after exertion) should be explained to them. In an hour after the end of the march the men should change their underclothing, and hang the wet things up to dry ; when dry they should be shaken well, and put by for the following day. Some officers, however, prefer that their men should at once change their clothes and put on dry things. This is certainly more comfortable. But, at any rate, exposure must be prevented. At the end of the march inspect the footsore men. Footsoreness is generally a great trouble, and frequently arises from faulty boots, undue pressui-e, chafing, riding of the toes from narrow soles, etc. Rubbing the feet with tallow, or oil or fat of any kind, before marching, is a common remedy. In the late war the Germans found tannin veiy useful, — they used an ointment of one part of tannin to twenty parts of zinc ointment. A good plan is to dip the feet in very hot water, before starting, for a minute or two ; wipe them quite dry, then rub them with soap (soft soap is the best), till there is a lather ; then put on the stocking. At the end of the day, if the feet are sore, they should be wiped \nih. a wet cloth, and rubbed with tallow and spirits mixed in the palm of the hand (Galton). Pedestrians frequently use hot salt and water at night, and add a little alum. Some- times the soreness is owing simply to a bad stocking ; this is easily remedied. Stockings should be frequently washed ; then greased. Some of the Ger- man troops use no stockings, but rags folded smooth over the feet. The French use no stockings. Very often soreness is owing to neglected corns, bunions, or in-growing nails, and the surgeon must not despise the little 268 PRACTICAL HYGIENE. surgery necessary to remedy these things ; nothing, in fact, can be called little if it conduces to efficiency. As shoes are often to blame for sore feet, it becomes a question whether it might not be well to accustom the soldier to do without shoes. Frequently men fall out on the march to empty the bowels ; the fre- quency with which men thus lagging behind the column were cut off by. Ai-abs, led the French in Algeria to introduce the slit in the Zouave trous- ers, which require no unbuckling at the waist, and take no time for adjust- ment. At a long halt, if there is plenty of water, the shoes and stockings should be taken off, and the feet well washed ; even wiping with a wet towel is veiy refreshing. The feet should always be washed at the end of the march. Occasionally men are much annoyed with chafing between the nates, or inside of the thighs. Sometimes this is simply owing to the clothes, but sometimes to the actual chafing of the parts. Powders are said to be the best — floxrr, oxide of zinc, and above all, it is said, fuller's earth. If blisters form on the feet, the men should be directed not to oj^en them during the march, but at the end of the time to draw a needle and thread through ; the fluid gradually oozes out. All footsore men should be ordered to report themselves at once. Sprains are best treated with rags dipped in cold water, or cold spirit and water with nitre, and bound tolerably tight round the part. Eest is often impossible. Hot fomentations, when procurable, will reheve pain.' Marches, especially if hurried, sometimes lead men to neglect their bowels, and some trouble occui's in this way. As a rule, it is desirable to avoid purgative medicines on the line of march, but this cannot always be done ; they should, however, be as mild as possible. Kobert Jackson strongly advised the use of vinegar and water as a re- freshing beverage, having probably taken this idea from the Komans, who made vinegar one of the necessaries of the soldier. It was probably used by them as an anti-scorbutic ; whether it is very refreshing to a fatigued man seems uncertain. There is only one occasion when spirits should be issued on a march : this is on forced marches, near the end of the time, when the exhaustion is great. A little spirit, in a large quantity of hot water, may then be useful, but it should only be used on great emergency. Warm beer or tea is also good ; the warmth seems an important point. Eanald Martin and Parkes tell us that in the most severe work in Burmah, in the hot mouths of April and May, and in the hot hours of the day, warm tea w-as the most refresh- ing beverage. Travellers in India, and in bush travelUug in Australia, have said there was nothing so reviving as warm tea. Chevers mentions that the juice of the country onion is useful in lessening thirst during marches in India, and that, in cases of sun-stroke, the natives use the juice of the un- ripe mangoe mixed with salt. Music on the march is very invigorating to tired men. Singing should also be encouraged as much as possible. Marching in India. — Marches take place in the cool season (November to February), and not in the hot or rainy seasons, except on emergency ; yet marches have been made in hot weather without harm, when care is taken. They are conducted much in the same way as in cold countries, except that ' The following is a very good lotion for sprains : sal-ammoniac, 20 grains, vinegar and spirit, an ounce of each. CONDITIONS OF SERVICE. 269 the very early morning is usually chosen. The men are roused at half-past two or three, and parade half an hour later ; the tents are strack, and car- ried on by the tent-bearers ; coffee is served out, and the men march off by half-past three or four, and end at half-past seven. Everything is ready at the halting-ground, tents are pitched, and breakfast is prepared. These very early marches are strongly advocated by many, and are op- posed almost as strongly by some. In the West Indies, marching in the sun has always been more common than in the East. Much must depend on the locality, and the prevalence and time of hot land winds. Both in India and Algeria marches have been made at night ; the evidence of the effects of this is discordant. The French have generally found it did not answer ; men bear fatigue less well at night ; and it is stated that the admissions into hospital have alsvays increased among the French after night march- ing. Annesley's authority is also against night marching in India. On the other hand, it is stated by some that in India the march through the cool moonhght night has been found both pleasant and healthy. Afternoon marches (commencing about two hours before sunset) have been tried in India, and often apparently with very good results. Marching in Canada. — In 1814, during the war v^^th America ; in 1837, during the rebellion ; and, in 1861-62, dm-ing the Trent excitement, winter marches were made by the troops, in aU cases without loss. The following winter clothing was issued at home : — A sealskin cap with ear lappets ; a wooUen comforter ; two woollen jerseys ; two pairs of woollen drawers ; a chamois leathern vest with arms ; two pairs long woollen stock- ings to draw over the boots ; sealskin mits ; and a pair of jackboots. In Canada a pair of blankets and mocassins were added,' and, at the long halts, weak hot nim and water was served out. A quarter of a pound of meat was added to the ration. A hot meal was given before starting, another at mid-day, and another at night. The troops were extremely healthy. During exposure to cold, spirits must be avoided ; hot coffee, tea, ginger tea, or hot weak wine and water, are the best ; it is a good plan to i-ub the hands, feet, face, and neck with oil ; it appears to lessen the radia- tion of heat and the cooling effect of winds. 1 See Inspector-General Muir's Report, Army Medical Reports, vol, iv., p. 378. CHAPTER III. THE EFFECTS OF MILITARY SERVICE. The influence of the various conditions of military life is shown by the records of sickness and mortality, and this must be noted in the various stations. The recruit having entered the ranks, begins his service at home, and he is kept at his depot for some time. He does not go on foreign service until he has completed his twentieth year. We should suppose his hfe would be a healthy one. It is a muscular, and, to a certain extent, an open-air life, yet without great exposure or excessive labor ; the food is good (though there might be some improvement), the lodging is now be- coming excellent, and the principles of sanitation of dwellings are care- fully practised. Although the mode of clothing might be improved as re- gards pressure, still the material is very good. There is a freedom from the pecuniary anxiety which often presses so hardly on the civil artisan, and in illness the soldier receives more immediate and greater care than is usual in the class from which he comes. There are some counterbalancing considerations. In a barrack, there is great compression of the population, and beyond a doubt the soldier has greatl}^ suffered, and even now suifers, from the foul air of barrack rooms. But this danger is greatly lessening, owing to the exertions of the Barrack Improvement Commissioners, and, as is proved by the experience of some convict jails, can be altogether avoided. Among the duties of the soldier is some amount of night-work ; it is certain that this is a serious strain, and the Sanitary Commissioners, there- fore, inserted in the "Medical Regulations" an order that the number of nights in bed should be carefully reported by medical officers. Major-Gen- eral Sir Fredei'ick Roberts, G.C.B., has lately called marked attention to the injurious effects of night duty and " sentry-go.'" Commanding officers should be informed how seriously the guard and sentry duties, conducted as they are in full dress, tell on the men if they are too frequent ; one guard-day in five is quite often enough, and four nights in bed should be secured to the men. Exposure during guard and transition of temper- atui'e on passing from the liot air of the guard-room to the outside air are also causes of disease. The weights and accoutrements are heavj', but the valise equipment introduced by General Eyre's Committee has removed the eril of the old knapsack. The habits of the soldier are unfavorable to health ; in the infantry, especially, he has much spare time on his hands, and ennui j^resses on him. Ennui is, in fact, the great bane of armies ; though it is less in our own than in many others. It is said to weigh heavily on the German, the Rus- sian, and even on the French army. Hence, indeed, part of the restlessness ' Nineteenth Century, November, 1882. THE EFFECTS OF MILITARY SERVICE. 271 and one of the dangers of large standing armies. The Romans appear to have avoided this danger by making their distant legions stationary, and permitting maniage and settlement — in fact, by converting them into mili- tary colonies. We avoid it in part by our fi-equent changes of place, and our colonia] and Indian ser^'ice ; but not the less, both at home and abroad, do idleness and ennui, the parents of all evils, lead the soldier into habits which sap his health. Not merely excessive smoking, drinking, and de- bauchery, but in the tropics mere laziness and inertia, have to be combated. Much is now being done by establishing reading-rooms, trades, industrial exhibitions, etc., and by the encouragement of athletic sports to occupy spare time, and akeady good results have been produced. The establishment of trades, especially, which wih not only interest the soldier, but benefit him pecuniarily, is a- matter of gi-eat importance. It has long been asked why an army should not do all its own work ; give the men the hope and opportunity of benefiting themselves, and ennui would no longer exist. In India, Lord Strathnaim did most essential service by the establishment of trades ; and the system, after long discus- sion and many reports, is now being tried in England. One of the proofs of abOity for command and administration is the power of occupying men, not in routine, but in interesting and pleasant work, to such an extent that rest and idleness may be welcomed as a change, not felt as a burden. Constant mental and much bodily move- ment is a necessity for all men ; it is for the officers to give to theu' men an impulse in the proper du-ection. The last point which, probably, makes the soldier's life less healthy than it would otherwise be, is the depressing moral effect of severe and haras- sing discipline. In our own army in former years, it is impossible to doubt that discipline was not merely unnecessarily severe, but was ab- solutely savage. An enhghtened pubhc opinion has gradually altered this, and with good commanding officers, the diseiphne of some regiments is probably nearly perfect ; that is to say, regular, systematic, and unfail- ing ; but from its very justice and regularity, and from its judiciousness, not felt as irksome and oppressive by the men. The general result of the hfe at home on soldiers must now be con- sidered. It is by no means easy to say whether soldiers enjoy as vigorous health as the classes from which they are drawn ; the comparison of the number of sick, or of days' work lost by illness by artisans cannot be made, as soldiers often go into hospital for sHght ailments which will not cause an ariisan to give up work. The comparative amount of mortahty seems the only available test, though it cannot be considered a very good one. Following the order laid down in the chapter on Statistics, we have to consider — SECTION L THE LOSS OF STRENGTH BY DEATH AND INVALIDING, PER 1,000, PER ANNUIVL A. By Death. It is to be understood that the mortahty is here reckoned on the strength, that is, on the total number of healthy and sick persons actu- ally serving during the time. The mortality on the sick alone is another matter. 272 PRACTICAL HYGIENE. From the Parliamentary Statistical Keturns of the Army (1840 and 1853, which include the years 1826-1846), we find that the mortality among the cavalry of the line was at that time about one-thu-d more than among the civil male population at the same age (nearly as 15 to 10 ' jDcr 1,000) ; among the Foot Guards it was more than double (very nearly 20^ per 1,000 as against 10) ; among the infantry of the line it was three-fom*th& more (or 18 per 1,000 as against 10). The State was thus losing a large body of men annually in excess of what would have been the case had there been no army, and was therefore not only suffering a loss, but incurring a heavy responsibility. In the splendid men of the Household Brigade, diseases of the lungs (including phthisis) accounted for no less that 67.7 per cent, of the deaths, in the cavalry of the line for nearly 50 per cent., and in the infantry of the line for 57 per cent. ; while among the civil population of the soldiers' age, the proportion in all England and Wales was only 44.5 per cent, of the total deaths. The next chief causes of deaths were fevers, wliich accounted in the difierent arms of the service for from 7 to 14 per cent, of the total deaths. The remainder of the causes of deaths were made up of smaller items. These remarkable results were not peculiar to the English Army. Most armies did, some still do, lose more than the male civil population at the same age. The following are the most rehable statistics : — ' Army Loss per 1,000. France (1823) 28.3 France (Paixhans, 1846) 19.9 France, mean of 7 years (1862-68) 10.0 France (1869) 9.55 France (1872) 9.49 French in Algeria (1846) 64 French in Algeria (1862-66) 14.98 Prussian' (1846-1863, including officers) 9.49 Prussian (1869) 6.10 Prussian army (including the Saxon and Wiirtemberg corps (1876). 4.96 Prussian* (1867) 6.54 Kussian^ (series of years) 39 Russian (1857-1866) 18.7 Austrian 28 Austrian (1869) 11.58 Piedmontese (1859) 16 ItaUan (1870) 8.40 United States (before the war) 18.8 Portuguese (1851-53) 16.5 Danish 9.5 ' In reality the deaths from the civil male population of the soldiers' ages (20 to 40) were below ten, and in the healthy districts much below ; the case against the soldier is, therefore, even worse than it reads in the text. '^ Meyne (Elements de Stat. Med. Militaire, 1859) gives some of these figures ; others are taken from the reports of the different armies. 3 Dr. Engel, in Zt. des Kiinigl. Preussich. Stat. Bureaus, Aug.-Sept., 1865, p. 214. * Stat. Sanitats-bericht iiber die Kon. Pr. Armee, for 1867, Berlin, 1870. Without deaths of invalids the mortality was only 6. 19G. The men were all under thirty years of age, which must be taken into account. * The Russian mortality has lately been greatly reduced. THE EFFECTS OF 3nLITAEY SERVICE. 273 The old HanoTerian airmy was vei'r healthT, losing only 5.3 per 1,000 as against 9.5 among the ci^il poj)iilation of the same ages. In these foreign armies the same nole holds good ; fevers (chiefly typhoid in all probabihty ) and phthisis were the gi-eat caiises of mortality. In Prussia phthisis formerly caused 27 per cent, of the total mortality, but in that army phthisical men are sent home, and after a certain time are struck off the rolls, so that the anny deaths are thus fewer than they would be if the men died at their regiments. In Austria phthisis caused 25 deaths out of every 100 ; in France, 22.9 ;' while in 1859, the proportion among the civil population was 17.76 ; in Hanover, 39.4 ; and in Belgium, 30 ; though in the latter country the propoi-tion among the civil population was only 18.97 deaths from phthisis per 100 of all deaths. In Portugal the mortality from phthisis consti^:uted 22 per cent, of the deaths," while in the civil population the deaths are 12 per cent, of the total deaths. In the Prassian army in 1876 only 16 per cent, were from phthisis. In these aiTuies, also, fevers caused a gi'eater number of the deaths than in the EngHsh army, even in the period referred to. In Prussia, 36 (reduced in 1876 to 20j ; in France, 26 f in Belgium, 16.6 ; and in Hanover, 23.68 per cent, of all deaths were from fever (t\-phoid ?) . In Portugal only 3.9 deaths are from t\-phoid out of every 100 deaths ; this is owing to its rarity in the country districts ; it is common in Lisbon. Nothing can prove more clearly that in all these armies the same causes were in action. And from what has been said in previous chapters, it may be concluded that the reason of the predominance of these two classes, lung diseases and typhoid fever, must be sought in the imi^ure ban-ack aii', and in the defective removal of excreta. The Crimean war commenced in 1854, and ended in 1856. A large pai't of the army was destroyed, and a fi'esh force of younger men took its place. Soon afterward, the great sanitaiy reforms of Lord Herbert commenced. In 1859 yearly statistical returns began to be pubhshed. The mortahty of all arms has undergone an extraordinary decrease from that of the former period. Mortality per 1,000, per Annum, in Tnited Kingdom. From all From Disease alone 'i.e., Causes. excluding violent deaths). Mean of ten years, 1861-70 9.45 8,534 Mean of ten rears, 1870-79 8.18 1880 ] 6.83 5.876 The diminution over the years previously noted (1826-46) is extra- ordinaiw. Three causes only can be assigned for it — the youth of the army, and a better selection of men ; or a j^artial removal of the causes of dis- eases ; or earher invaliding, and the action of the Limited Enlistment Act, so as to throw the fatal cases on the civil population. ' This was in 1860 : calculated from Laveran"s returns from eleven of the great garrisons. - 3Iarques, reviewed in an excellent article in the British and Foreign liledico-Chir. Eeview for April, 1863. " Laveran. in 1860, made the number 25.9 in the deaths from eleven garrisons. In 1863 the mortalitj from typhoid in the French army was 1.87 per 1,000 of effectives in France, 1.63 in Algeria, and 3.55 in Italy. In 1S66 the mortality was 1.45 in France, 1.39 in Algeria, and 2.26 in Italy. Vol, IL-18 274 PRACTICAL HYGIENE. The question of age has been examined and disposed of by Dr. Balfour,' ■v\ho has shown that the youth of the army does not account for the lessening. Selection has always been made with equal care, and invaliding, though it certainly has been greater of late years, does not appear to have been in excess sufficient to account for the lessening. There can be no doubt, then, that the great result of hahing the yearly loss of the army by disease has been the work of Lord Herbei-t and the Royal Sanitary Commission. It will be observed that the amount of the mortality in the French anny was also siugiilarl}^ lessened from 1846 to 1862 and 1863, and this is, no doubt, owing to the great sanitary pi*ecautions now taken in that army. Of the different arms of the service, the cavah-y and artillery are rather healthier than the infantiy ; the engineers than either ; the oihcers always show less mortahty than the non-commissioned officers and privates, and the non-commissioned olEcers less than the privates. In different regiments there is often a singulai- ditierence in the mortality in a given year, but this is usually easily accounted for, and in a term of years the difl'erences disappear. Comparison loith Civil Population. This gross mortahty must now be compared Avith that of the civil popu- lation. In England the gross male ci^il mortahty at the soldier's age is — Mortality per 1 ,000 of Population. From 20 to 25 years of age 8.83 " 25 to 35 " 9.57 " 35 to 45 " 12.48 The soldier's mortahty, taken as a whole, is therefore under that of the civil population, but then there is invaliding, and some uncertain addition should be made to the mortahty on this account. Comparing the soldier's mortality (for a ten yeai's' period, and invalid- ing being disregarded) with trades, he is more imhealthy than cai-penters (7.77), laborers (7.92), bakers (7.94), and blacksmiths (8.36). But he is healthier than grocers (8.4), farmers (8,56), weavers and cotton -spinners (9.1), shoemakers (9.33), butchers (9.62), miners (9.96), tailors (11.62), and publicans (13.02).^ Influence of Age on the Mortality. The following table gives the results : — ^ Per 1,000 of Strength. Under 20. 20 and under 25. 26 and under 30. 30 and under 35. 35 and under 40. 40 and upward. 1870-79 (10 years) 1880 3.11 3.00 6.89 5.83 5.08 4.80 8.67 7.3 6.18 5.75 9.55 7.93 11.64 10.23 10.37 8.36 17.28 15.99 11.96 8.96 24.09 21.92 Civil male population in England and Wales Healthy districts 18.96 9.86 ' Army Medical Report for 1859, p. 6. - Dr. Farr's numbers, in the Supplement to the 25th Report of the Registrar-Gen- eral, p. 16. ^ Army Medical Reports, vol. xxii., 1882, p. 30. THE EFFECTS OF MILITARY SEEVICE. 275 The number of soldiers under 20 years of age is so small that no con- clusions can be drawn ; but it would appear that from 20 to 30 the mortahty is favorable to the soldier, but after that the proportion is reversed, and the soldier dies more rapidly than the civilian. And if to this we call to mind the invaliding from the army, it seems clear that a prolonged military career is decidedly injurious, either from causes proper to the career, or to personal habits engendered in it. Causes of Mortality. In order to see the principal causes of the eight or nine deaths which occur annually among 1,000 men, the following table has been calculated from the " Army Medical Keports" : — Causes of Mortality.^ PMliisis and tu- bercular haemop- tysis Diseases of heart and vessels . . . . Pneumonia Violent deaths .... Diseases of ner- vous system. . . . Continued fevers, chiefly enteric . . Suicides Bronchitis Delirium tremens. . All other causes . . Mortality per annum per 1,OOU of Strength (1867-71, 5 years). 2.648 1.463 .777 .598 .576 .405 .288 .167 .069 1.756 Deaths in 100 Deaths (1867-71, 6 years). 30.26 16.71 8.88 6.84 6.58 4.63 3.30 1.91 .80 20.07 Mortality per annum per 1,000 of Strength (1872-80, 9 years). 2.29 1.17 1.34- .61 .54 .30 .21 1.42 Deaths in 100 Deaths (1872-«0, 9 years). 29.0 14.8 17.0 5 7.7 6.8 3.8 2.7 18.2 This table must now be analyzed more particularly. 1. TUBEECUIiAR DISEASES. The deaths from phthisis and haemoptysis in the eight years ending 1866 averaged 3.1 annually per 1,000 of strength, the highest annual ratio being 8.86, and the lowest 1.95. In 1867-71 the mean mortality was 2.648 per 1,000, in 1872-80, 2.29. In addition to this there was invaliding for phthisis, and thus a certain number of deaths were transferred from the army to the civil population. The following table shows the exact number in four branches of the service (two cavah-y and two infantry) in seven years : — ' This table has been calculated from the numbers in the Army. Med. Department Blue Books (1867-80). '■* The abridged and incomplete form in which the statistics have been published since 1874 render it impossible to give these numbers in detail. The niambers opposite pneitmonia for the later period include all disease of the Respiratory System — and the deaths from delirmm tremens are included under the head of Poisons. 276 PRACTICAL HTGIEITE. Table to shoiv the Deaths mid Invaliding per annum from Phthisis and ffcemojitysis in Household Cavalry, Gaoalry of the Line, the Foot Guards, and Infantry of the Line {mean of seven years, 1864-70). Phthisis and hsemoptysis, taken from Abstract in Appendix to Dr. Balfour's Eeport. Household Cavalry. Cavalry of Line. Foot Guards. Infantry of Line. Died per 1,000 Invalided per 1.000. .. Total died and inva- lided per 1,000 3.763 8 234 11.997 1.416 4.025 5.441 2.300 9.491 11.791 2.120 5.510 7.630 This table shows a considerable difference between the branches of the service ; the mortality and invaliding of the household troops ai'e much the highest. The mortality from tuberculosis of the infantry of the hne is below the mean mortality of the army at large ; the mortahty of the cavalry of the hne below that of the infantry. It is quite clear (and the same thing is seen in the earliest records) that there has been an excessive rate of mortality and invahding from phthisis in regiments ser\'ing in London, which points to some influences acting very injuriously upon them. During the later years, however, the invahd- ing in the foot guards has decreased, although the mortahty has not diminished. It is remarkable that a similar excessive mortality has been obsen-ed in the guard regiments of both France and Prussia, located re- spectively in Paris and Berlin.' The following table shows the average of our own army up to 1876 : — Table similar to the one above, for 6 years, 1871-76. Phthisis, etc. Household Cavalry. Cavalry of Line. Foot Guards. Infantry of Line. Depots. 1873-76. Died per 1,000 3.33 4.44 7.77 1.46 4.30 5.76 2.43 7.17 9.60 2.15 4.00 6.75 4.18 Invalided per 1,000. . . . Total died and invalided per 1 000 9.82 14.00 From this table it may be seen that up to 1876 there was a slight di- minution of mortahty in the household cavalry and in the infantry of the hne, but that the rates were nearly stationary in the cavalry of the Ime and the foot guards, and very high in the depots. In the invaliding the rates were decidedly lower in the household cavalry, the foot guards, and the infantry of the line, whilst there was a slight increase in the cavalry of the line, and the rate was high in the depots. "Unfortunately, since 1876 this information is no longer available, it being omitted from the "Ai-my Medical Reports." How does this mortality compare \Nith that of the male ci\'il pojjulation at the soldiers' ages ? ' Both and Lex, op. cit., vol. iii., p. 392. i25 3.5 30 4.0 35 4.1 40 4.1 55 8.7 45 4.02 55 4.5 .. 5.0 THE EFFECTS OF MILITAEY SERVICE. 277 Mortality from, Phthisis. Male Civilians.' Age. AU England and Wales 20 to 25 25 « " 30 " " 35 « " 15 25 London 15 Worst districts in England, excluding hospitals 5.0 Best districts in England 1.96 The deaths in the anny from phthisis and haemoptysis are less than the deaths in the population generally. They are, however, on an average gTeater than in the best districts in England, although the rate for 1880 (viz., 1.98) was very nearly the same. But in the army there is invaliding also ; that is, men with a fatal disease ai-e discharged into the civil popula- tion. In 1880 there were invahded for tubercular disease 4.15 per 1,000, and this added to the deaths (1.98) gives 6.13 as the ratio of loss from that class of disease. Taking this into consideration, it seems certain that phthisical disease is still in excess in the ai-my as compared with the male civil population. Did the army suffer more from phthisis in former years than it does now ? The following table will answer this question : — Deaths from Phthisis per 1,000 of Strength. Years 1830-36, Tears 1837-46, = 7 years. = 10 years. Household Cavalry 7.4 6.28 Cavah-y of the Line 5.29 5.65 Foot Guards 10.8 11.9 Infantry 7.75 Mean 7.83 7.89 During these two periods, which make a total of seventeen years, the mortality was 7.86 per 1,000, and there was no dechne in the later as com- pared with the earlier period. But as in the 8 years ending with 1866 the mortaUty was only 3.1 per 1,000, in the 5 years ending 1871, only 2.6, in the 9 years ending 1880, only 2.3, and in 1880 itself under 2 per 1,000, giving for the whole period of 22 years only 2.6, there must have been an enormous excess of mortality in the earher period, unless it can be explained in some way. (a) In the earhest periods the mortality from chronic bronchitis was in- cluded in the phthisical mortality. If a correction is made for this, the mortahty of the period 1859-1880 would not reach 3.0 ; so that will not ex- plain the difference. (b) Was the invaliding more active in the last period, so as to lessen the deaths occurring in the army below what would have taken place without invahding ? The information about the early periods is scarcely obtain- ^ Parliamentary Return of Annual Average Mortality during the Decennial Period, 1851-60, February, 1864 ; and Dr. Farr's Report to the Sanitary Commission, p. 507. 278 PRACTICAL HYGIENE. able, but there seems no reason to think it was less than subsequently, but, on the contrary, it was very large from the foot guards. That invaliding cannot account for the difierence is seen by the fact that the annual deaths per 1,000 in the seventeen years ending 184G (viz., 7.86) were more num- erous (in the cavalry and infantry of the line) than the average of deaths and invaliding together in the period of five years ending 1871. (c) The Limited Enlistment Act, by which a certain number of weakly men may possibly have l^ft the army, was in action in the last period. It is impossible to estimate the amount of this action, but it is in the highest degree improbable that it had nuich dii'ect effect ; for if a man of nearly ten years' service were ill with phthisis, he would be sure to get invalided, in order to enjoy his temporary pension for two or thi'ee yeai's, and would not simjily take his discharge. (d) The lessened age of the army at large, if the Limited Enlistment Act has produced that effect, might perhaps have had some effect, as mor- tahty from phthisis increases with age in the French army, and probably in our own ; but this would never account for the astonishing difference ; for in the French army the increase from phthisis of the men over fourteen years' service, as compared with those under, is only 1 jDer 1,000 of strength. We may conclude, then, that there was a gi-eater excess of the disor- ganizing lung diseases classed as phthisis in the earlier period (1830-46). The amount of phthisis strongly attracted the attention of Sir Alexander Tulloch and Dr. Balfour in 1839, They state that in the Equitable Assur- ance Company at that time the annual mortality (at the ages 20 to 40) from disease of the lungs was 3.4 per 1,000 ; while in the years 1830-36 the mortality from disease of the lungs among the foot guards was no less than 14.1 per 1,000, of which phthisis alone caused 10.8,' How does our army contrast with others ? In France the deaths from phthisis and chronic bronchitis together amount to 2.75 i:)er 1,000 of "present," but some die "en conge;"" and it is probable that there is at present at least as much phthisis in the French as in our own army. Li the Prussian army the men are also discharged early, so that comparison is difiicult. In the Prussian army the mean yearly mortality from lai-jTigeal and lung phthisis was 1,28 per 1,000 of strength (years 1846-63) ; in 100 deaths there were 13.57, What the amount of invahding was at that time does not appear to be recorded, but in 1868-69 it was about 3 per 1,000 of strength,'^ We may conclude, then, with regard to phthisis — 1. That it was formerly in enormous excess in the army over the civil population, and particularly in the foot guards ; in other words, a large amount of consumption was generated. 2. That there has been a great decline of late years, though there is still in all probabiUt}'' some excess, especially in the household troops. What are the causes of this phthisical excess in the years 1830-46 ? It is noticeable that in the earlier periods all affections of the lungs were also ' In commenting on this fact the reporters say (Army Medical Report of 1839, p 13) — " If the aggregation of a number of men into one apartment, even though the space is not very confined, creates a tendency to this disease, then it clearly points out the propriety of affording the soldier as ample barrack accommodation as possible." Thus, even at that time, it was seen that no other cause but overcrowding could account for the great amount of lung disease. " Roth and Lex, op. cit., vol. iii., p. 391. THE EFFECTS OF MILITARY SERVICE. 279 in excess, and we can readily see that a number of antecedents may com- bine in producing the result, and that destructive lung diseases may proceed from many causes. Still there must have been some predominating in- fluence at work. The phthisis was not owing to climate, for that is unchanged. More' over, we shall hereafter see that the same excess was seen in the Mediter- ranean stations and the West Indies. It was not owing to syphilis, for until late years the amount of syphilis has rather increased than diminished, while phthisis has lessened. It was not owing to bad food, for the food was the same in all the branches, and yet the amount of phthisis was widely different. Besides, the food has been comparatively little altered. It can hardly haye been the duties or clothing, for there has been no sufficient change in either to account for the alteration, unless the abolition of one of the cross-belts some years ago had some effect. But then this would have only affected the infantry. It must have been some conditions acting more on the foot guards than in the household cavalry, and less in the line regiments ; also it must have been acting in the troops stationed in the Mediterranean and the West Indies. There is only one condition common to all which seems capable of explaining it, and that the cause noticed in the Eeport of 1839, viz., overcrowding. This condition was, and is still most marked in the barracks of the foot guards, and least in the barracks of the cavalry of the line. It is the only condition which has undergone a very decided change both at home and abroad. This consideration, as well as those formerly noticed in the section on Air, seems to make it almost certain that the breathing the foul barrack atmosphere was the principal, perhaps the only, cause of this great mortality from lung diseases. If this be so, it shows that the foot guards are still the worst housed of any troops. 2. DISEASES OF THE HEART AND VESSELS. The fact that diseases of the circulatory system rank second as causes of death in the army at home may well surprise us. It is marked in all arms, as much in the artillery and cavalry as in the infantry. The ratio per 1,000 of strength for the five years (1867-71) for all diseases of the organs of circulation was 1.462, and in those years out of eveiy 100 deaths no less than 16.7 were from disease of the heart and vessels. In addition, there was a large amount of invaliding from this cause. If the fatal diseases of the cu-culatory system of the five years (18G7-71)' are divided into two classes, those referred to some disease of the heart itself (chiefly chronic), and those referred to aneurism (including an occa- sional rare return headed " Degeneratio Aortse "), it is found that the deaths are : — Per 1,000 of Strength. In 100 Deaths. From cardiac disease .727 8.31 From aneurism .735 8.4 Total 1.462 16.71 These numbers are higher than those of the nine years (1859-67), when ' In the recent returns the differential diagnosis is not given. In the 9 years, 1872- 80, the deaths per 1,000, from diseases of the circulating system, were 1.17, and the per- centage of total deaths, 14.8. 280 PRACTICAL HYGIENE. tlie mortality from circulatory diseases was only .908 per 1,000 of strength, and the percentage on the total deaths was 9. This mortality is in excess of that of the civil male population of the same age, especially as regards aneui-ism. Dr. Lawson has calculated that aneiu'ism is eleven times more frequent among soldiers than ci\alians ; and he has also calculated that among civilians, aged 15 to 44, the ratio of mortality from cardiac affections alone is .45 per 1,000. The army, then, in the je-avs 1867-71, had an excess of .277 per 1,000 of heart disease. Myers' statistics are contirmatoiy. The amount of heart disease is greater among the foot guards than among the metropohtan poUcemen. Myers in his able treatise ' gives the following numbers :— Foot Guai'ds . Police , Died per 1,000. .29 Invalided per 1,000. 3.2 1.37 It is greater among soldiers than sailors ; from six years' observations (1860-65) Myers" makes the navy mortality .66, and the invahding 3.44 per 1,000 ; while in the army in the same years the mortality was .9, and the invaliding 5.26. If the different arms of the service are taken, the following numbers are given by the five years 1867-71 : — Cavalry of Guard. Cavalry of Line. Artillery. Foot Guards. Infantry of Line. Mean yearly strentrtli 1,213 1 2 .181 .329 8,468 24 37 .566 .873 9,417 57 49 1.210 1.041 5,749 19 20 .661 .695 31,729 Total deaths from disease of the heart in five vears 73 Total deaths from aneurism in five years 103 Heart deaths per 1 ,000 of strength Aneurismal deaths per 1,000 of strength per annum .460 .649 The numbers in the household cavah-y are so small, it is not safe to use them ; but the other numbers are sufficiently large to render it probable that the artillery show a larger proportion of fatal cardiac and aneurismal cases than any other body of troops. The line cavahy and hne infantry both show rather an excess of aneurismal over heart deaths ; while the ai'tillery show more heart than aneurismal deaths, and in the foot guards the proportion is equal. The point which comes out clearly from the table, in addition to the large amount in all, is the excess of both classes of deaths in the ai'tiUery ; that it is a real excess is seen b}- comparing the yearly number of the ai-tillery and cavalry of the hne, who did not differ greatly in mean strength. The production of these diseases of the circulatory organs begins very early in the mihtary career. In 1860-62 Dr. Parkes calculated out the causes of invaliding in 6,856 men. Of these 1,014 were under two years' service. In the whole number the percentage of heart and vessel disease as the cause of the invaliding was 7.7 ; among the men under two years' service it was 14.23 jjer cent. As these men had presum- ably healthy hearts when they enhsted, the effect both of the mihtary life ' Diseases of Heart among Soldiers, by A. B. R. Myers, Coldstream Guards, don, 1870. 2 Ibid. ^ p. 11. Lou- THE EFFECTS OF MILITARY SERVICE. 281 in producing diseases of the cii'culatory organs, and the greater suffering from it of young soldiers, seems certain. The statistics in the Knapsack Committee's Report confirm this. The cause of this preponderance in the army of diseases of the circula- toiy organs is a matter of great importance. Whatever they may be, it is probable that they produce both the cardiac and the arterial disease. The two most common causes of heari disease in the civil population are rheumatic fever in young, and renal disease in older persons. The latter cause is certainly not acting in the army, and the foiTuer appears quite insufficient to account for the facts. A great number of the men ■who suffer from heart and vessel disease have never had acute rheumatism ; and if we refer the affection to slight attacks of muscular rheumatism, which almost e\ery man has, we ai-e certainly going beyond what medical knowledge at present waiTants. The effect of lung disease in producing cardiac affections is also not seen in the army to any extent. The influence of sypMhs in producing structural changes in the aortic coats was noticed by Morgagni. In 114 post-moiiem examinations of soldiers dying at Netley, Dr. Davidson ^ found 22 cases of atheroma of the aorta. Of those 17 had a syphilitic histoiy, 1 was doubtful, and 4 had had no syphihs, but had heart and lung diseases. Of the whole 114 cases, 78 had no syphUitic history and had 4 cases of atheroma, or 5.1 per cent. ; 28 had a mai'ked syphihtic history and 17 had atheroma, or no less than 60.7 per cent. This seems very strong evidence as to atheroma. "With respect, however, to actual aneurism, no corresponding analysis of cases has been made, and therefore at present the effect of syphilis must be considered uncertain ; but it is c[uite clear, even admitting its influence, there is no reason to think that syphilis prevails more among soldiers than among the civil male population of the same class. It is, therefore, unlikely that an excess of syphilis, if it really occm-s among soldiers, and if it actually predis- poses to aneurism, as seems probable, coiild produce 11 times as many an- etuisms as in ciril persons. Myers has also given evidence that both in the ai-my and navy aneurism is sometimes not preceded by degeneration of the arterial coats, and in these cases mere improper exertion seemed to produce it. The effect of excessive smoking again has been assigned as a cause of the soldier's cardiac disease ; but no one who knows the habits of many continental nations, and of some classes among our own, could for a mo- ment believe this to be the cause. Again, the effects of alcohol in constantly maintaining an excessive action of the heart, are so marked as to make it highly probable that this is a fact of gi'eat importance ; but soldiers do not diink so much, as compared with civilians, as to lead us to think the cause can explain the prevalence. There is, however, one cause wliich is continually acting in the case of soldiers, and that is the exertion (often rapid and long continued ) which some of the duties involve." The artillery have very heavy work ; often it is very- violent and sudden, more so perhaps than in any other coi-ps ; the cavah-y also have sudden work at times ; and the infantry soldier, though his usual labor is not excessive, is yet sometimes called upon for considerable exertion, and that not slowly, or with rests, but vnth. gi-eat rapidity. And this exertion ' Army Medical Department Report, vol. v., p. 481. - For a full and able discussion on all those points, and for additional evidence, ref- erence must be made to Mr. Myers' excellent -svork. On the effect of exertion during war in causing cardiac hypertrophy, reference may be made to Dr. Frantzel's paper in Virchow's ArcMv, Band Ivii., p. 215. 282 PRACTICAL HYGIENE. is in all arms undertaken with a bad arrangement of dress and of equipments. The cavali-y and artillery men are very tightly clothed, and though the horse carries some of the burden, it is imdoubted that the men are overweighted. In the infantry, till lately, they wore very tight-fitting tunics, with collars made close round the neck, and trousers (which were often kept up by a tight belt) ; there was a broad straj) weighted below with a heavy pouch and ammunition, crossing and binding down the chest ; and there was the knapsack constricting the upper part of the chest, and hindering the au' from passing into the proper lobes. The production of heart disease ought not to be attributed solely to the knapsack, as is sometimes done ; the knapsack is only one agency ; the cross- belt was probably worse, and the tight clothes add their influence. But even with the knapsack alone the effect on the pulse is considerable, and one or two of Dr. Parkes' experiments may be given in illustration. Thus, four strong soldiersc arried the old regulation knapsack, service kit, great-coat, and canteen, but no pouch and no waist-belt (except in one man). The pulse (standing) before marching was on an average 88 ; after 35 minutes it had risen on an average to 105 ; after doubling 500 yards, to 139, and in one of the men was 164, irregular and unequal After the double they were all unfit for 'further exertion. In a fifth man, who was not strong, the 85 minutes' marching raised the pulse from 120 to 194 ; after doubling 250 yards, he stopped ; the pvdse then could absolutely not be felt. In another series, the average pulse of four men, with the knapsack only, was 98 (stand- ing), after one hour's march, 112 ; after their doubling 500 yards, 141. If the jjouch with ammunition is added, the effect is still greater. Dr. Parkes also took the pulse and respu'ations after long marches, and found the effect still more marked. Walking, of com-se, will quicken the pulse and respira- tion in any man, but not to such an extent, and the sense of fatigue in un- incumbered men is much less. In the lecture formerly alluded to,' Dr. Maclean put this matter most forcibly before the authorities, and he is undoubtedly quite justified in the expression that one cause of the cardiac (and perhaps of the aortic and pulmonar}') disease in the army is to be found in exertion carried on imder unfavorable conditions. Happily, much has been lately done by the authorities to remove this cause ; but still, especially in the artillery and mounted service,^ changes appear to be necessary, and in all arms it is desirable that oflicers should allow their men to do then- work under the easiest conditions, as regards clothes, weights, and attitudes, consistent with miUtary discipline and order. 3, THE NERVOUS DISEASES. These form a very heterogeneous class ; apoplexy, meningitis, paralysis, mania, etc., are the chief headings. The proportion to 1,000 of strength is about .6, and 6.G deaths of every 100 are owing to nervous diseases. ' Eoyal United Service Institution Journal, 1863, vol. viii. "The cardiac diseases are of the most varied kind. Dr. Parkes wrote — " I have seen at Xetley, in Dr. Maclean's wards, in one hour in the summer, when the hospital is full, almost all the combinations of heart affections. It has appeared to me that it" anything gives the tendency to heart affections, then tlie dress and accoutrements como in as accessory causes, and prevent all chance of cure. In some cases tliere is no valvu- lar disease, and not much hypertrophy of the heart, but a singular excitability, so that the heart beats frightfully quick on the least exertion." THE EFFECTS OF MHJTAEY SERVICE. 283 As among tiie male civil population (ages 25 to 35) tlie deaths are also 6. 6 per cent, of total deatlis, soldiers do not appear to suffer more. 4. p^■EImox[A AinD acute beoxchitis/ Table to shoic the admissions and deaths per annum, per 1,000 of strength, years 1859-71 {thirteen years). Average Highest in tliirteen years Lowest in thirteen years. Pnenmonia. Acute Bronchitis. Admissions. 5.25 7.13 3.49 .641 .741 .423 55. 65 88.00 39.10 .227 .380 .080 The acute inflammatory diseases of the lungs give, therefore, a mean annual mortality of .856 per 1,000 of strength. The mean total deaths from diseases of the respiratory system, for the nine years (1872-80j was 1.34 per 1,000, causing IT jDer cent, of total deaths. In the French army pneumonia gives a lower, and acute bronchitis a higher, mortality than in oui' own, but this is perhaps a mere difference of nomenclatui'e. The opinion that the military suffer more than the civil population fi-om pneumonia is an old one. It is also generaUy beheved that they suffer less in the field than in ganison. Tinistworthy statistics seem wanting as to the amount among the civil poj)ulation. In the Eui'opean population, gen- erally, Ziemssen" gives the deaths fi'om pneumonia as 1.5 ; and Oesterlen,^ 1.25 per 1,000 ; but this includes aU ages, and both sexes. Among men alone it is certainly gi'eater than among women. In London, in 1865, the mortality from pneumonia, between the ages 20 and 40 (both sexesj, was 1 per 1,000 population.'' If this be con-ect, the mortality among soldiers is below the civil mor- tality, or soldiers ai'e less subject than civilians ; for, as men are more subject to pneumonia than women, the mortality among the ci^ihan males •would be greater than 1 per 1,000, but the mihtary mortahty is only .641. The mortahty among the army pneumonic cases (deaths to treated) amounts (average of thirteen years) to 12.18 per cent.,° and as this is very neai'ly the civil proportion, ever\- 1,000 of population in London gave nine cases of pneumonia, while 1,000 soldiers gave only five. It may be said, however, that London is not a fair test ; but as a place of residence for sol- diers it does not appear to predispose to pneumonia, as will be seen from the foUovring table : — Per 1.000 of Strength, yeaK 1864-71. Foot Guards Infantry in the in London. Kingdom generally. Admissions from pneumonia 3.75 6.06 Deaths from pneumonia 44 .66 ^ Separate data are not published in the Armr ^ledical Eeports, for the later years. 'Monats-Bl. fiir Med. Stat., 1S57, and Schmidt's Jahrb., 1862, Xo. 3, p. 337. SMed. Statist., 2d edit., p. 567. * Tacher, Sur la Mort. en 1865, Paris, 1866, p. 137. ° In thirteen years there -vrere 4,826 cases treated, and 588 deaths, or 12.18 deaths per cent. In Canada the deaths to admissions were only 7.13 deaths per cent, (average of twelve years ending 1S70). 284 PRACTICAL HYGIENE. The mortality to cases treated in the five years (1867-71) was, in the Guards, 10. G8, and in the infantry, 11.7 percent. Although it does not seem that pneumonia (and acute bronchitis ?) are more common or more fatal among soldiers serving at home than among civihans, the above figures show what a fatal disease pneumonia is, and how worthy of renewed study its causes are. 5. THE CLASS OF CONTINUED FEVERS. Tlie returns do not carefully distinguish the several forms, but practi- cally the majority of the fatal cases of " continued fever " are from enteric (tj'jihoid) fever. There has been a great decline in this class of late. In the ten years (1837—46) the average admissions were 62, and the deaths 1.72 per 1,000 of strength. In the eight years ending 1867, the admissions averaged 22, and the deaths .5 per 1,000 of strength. In 1871 there were onh' 80 cases of enteric fever and 22 deaths in the whole army of 87,000 men. In the four years ending 1875 the mean total deaths from continued fever were 0.37 per 1,000, and they amounted to 4.4 per cent, of the total deaths. In the five years ending 1880 the total deaths were 0.30 per 1,000, and the numbers to total deaths 4.1 ; in 1880 the numbers were respectively, 0.26 and 3.8. This mortality is decidedly below that of the male civil population of the same age, which amounts to 9.6 per cent, of total deaths, and veiy nearly 1 per 1,000 of population. During late years no points have been more attended to in the army than pure water supply and good sewerage, and we see the results in this very large diminution of deaths from the rate of the former period, and in the fact that in this jjarticular class of disease the soldier is far better off than the civil population. So also the cholera of 1866 passed very lightly over the ai-my at home (only 13 deaths out of 70,000 men), although in former epidemics the army suffered considerably. The decline of enteric fevers confirms most strongly the doctrine of its intimate dependence on bad sewage aiTangemeuts. The greatest amount of t^'phoid fevers in the army is in the gamsons in the seaports, the least in the camps. The other classes of disease causing mortality need no comment. Chronic bronchitis is no doubt to be chiefly refeiTed to phthisis (using that term as a generic word to include various disorganizing lung diseases), and delii'ium tremens is a return which Avill, no doubt, gradually disappear in fact, as it has ah-eady done in figaren from the published Eeports. The smaller items of mortality, making up about 22 out of eveiy 100 deaths, are various ; erysipelas, pypemia, syphilis, hej^atitis (in men fi'om foreign service), enteritis, rheumatism (from heart comj^lication probably, but rettu-ned as rheumatism), diabetes, ebriositas, scarlet fever, and dijoh- theria, are a few of the many causes which cany off a small number every year. The cancerous and kidney diseases are very few, as we might expect from the age of the men. To sum up the case as regards the present mortality on home service, it may be stated that for the last twenty-one years (up to 1880) there has been some lessening, but no great fall in the number of deaths. There is still much to be done in resj^ect of jjreventing disorganizing lung disease, disease of the circulatory organs, and even fever, for we ought not to be satisfied until the term enteric fever is altogether obliterated. A renewed study of the causes of pneumonia is also necessary, in order to see if some THE EFFECTS OF MILITAEY SERVICE. 285 way or other the attacks of that fatal disease cannot be lessened. There is no reason to think that we have yet toj.3hed the lowest jjossible Hmit of preventable disease ; but, on the contrary, we can see clearly that the soldier, compai::tively healthy as he is, may be made more healthy still. Some evidence in support of such a view may be found in the fact, that both at Gibraltar and in some of the West Indian stations the mortality has been lower in some years than it has ever been at home. But there is no reason why the home mortaUty should not be reduced to the standard of those foreign stations. A question now arises — Why, after thirty years of age, should the soldier die more rapidly than the civilian, though for the first ten years of his service he has a smaller mortahty ? The causes may be foreign ser- vice, bad social habits (i.e., excess of drinking and syphilis, or other effects of enforced celibacy), night duty, exposure on guard, and prolonged influ- ence of impure barrack air. But to which of these the result is owing could only be determined by accurate statistical inquiries of the causes of mortality at the older ages. We do not know these, and if the short ser- vice system continues we are hardly hkely to know them, so it is of no use to discuss a topic on which sufficient facts are not available. B. Loss OF Strength of the Aemy by iNVALrorNG. The amount of invaliding is influenced by other causes than mere inef- ficiency of the men ; sometimes a reduction is made in the army, and the opportunity is taken to remove weakly men who would otherwise have continued to serve. This was the case in 1861. As invaliding greatly af- fects the mortality of the army, a source of fallacy is introduced which it is not easy to avoid. During the seven years (1860-66), there were invalided every year nearly 37 men out of every 1,000, thus making a total loss by death and invaliding from disease of nearly 46 men per 1,000, or about one-twenty- second part of the whole force. In 1867 the invaUding was lower, viz., 22.18 per 1,000. For the ten years (1870-1879), the invaliding in the United Kingdom was at the rate of 27.18 per 1,000, and the deaths were 8.18, — making together 35.36, or one-twenty-eighth part of the force. For the whole army the numbers were, 22.15 and 12.67 — together 34.82, or slightly less. In 1880 the total loss for the United Kingdom was only one-thirty- fourth, and for the whole army one-twenty- eighth. The causes of the in- validing were formerly very carefully ascertained by Dr. Balfour, and in- serted in his Reports, but the information is now omitted from the "Army Medical Department Reports." Speaking in round numbers, for the j)eriod when detailed returns were furnished, phthisis and scrofula account for about one-foiu'th of the invalids, and if chronic bronchitis was included, for nearly seven-twentieths, the two items of hypertrophia cordis and morbus valv. cord, accounted for one-tenth, and chronic rheumatism for one-fourteenth. The three nervous diseases of amentia, mania, and epi- lepsy always caused a large number of invahds, amounting nearly to one- tenth, or almost the same as the two classes of heart diseases. All the other items were smaller. In men invalided under one year's service nearly one quarter were so from epilepsy ; the remaining chief causes were phthisis and diseases of the circulatory organs. It is probable that the loss from invaliding will continue to diminish as a consequence of the short service system. 286 PRACTICAL HYGIENE. SECTION n. LOSS OF SERVICE FROM SICKNESS PER 1,000 PER ANNUM. (a) Number of Admissions into Hospital. — On an average, 1,000 soldiers furnish rather under 1,000 admissions into hosi:»ital per annum ; 809.1 in ten years (1870-79). The number varies in the different arms from about 600 in the Household Cavalry and Engineers, which is usually the lowest, to about 1,100 in the Cavalry and Artillery Depots. In the first case the steady character of the men, many of whom are married, and in the second the frequency of contusions during drill, account for this great range. In the Infantry the average is from 850 to 1,020. In 1880 the highest rate was in the cavalry, 1,016.4, and the lowest in the Royal Engineers, 587.8, the Foot Guards showing 1,003.8, and the Infantry (including depots), 943.6. The number of admissions remained tolerably constant for twenty-five years, but during late years has been sensibly declining. The admissions in the French army are not comparable with ours ; slight cases of sickness (which with us are often not recorded) are treated in barracks [d la chambre), severer, but still slight, cases in the infirmaries, bad cases in the general hospitals. The mean of five years (1862-66) gives 2,028 total admissions per 1,000 "present." The admissions to the infirm- aries in France (in 1866) were 323 per 1,000 "present; " to the hospitals, 306 ; making a total of the severer cases of only 629 per 1,000 in that year. This shows how many slight cases there are in the French army. In the eight years (1862-69) the mean number of slight cases in France was 1,745 per 1,000 (Morache). In the Prussian army the average admissions (mean of 18 years, 1846- 63) were 1,336. In 1867 there were 1,125.6 per 1,000. In 1873-75 it was 750, and in 1876 only 620 (Roth). (&) Daily number of Sick in Hosjntal per 1,000 of Strength. — About one- twenty-fifth of the army is constantly sick in time of peace, or 4 per cent. The mean for the ten years 1860-69 was 4.78 per cent., (or one-twenty-first part), and for the ten years 1870-79, it was 3.95 per cent., or just under one-twenty-fifth. The numbers are therefore diminishing. It is not possible to compare the army sickness with the civil popula- tion, or even with other armies. In England, the number of members of friendly societies, between twenty and thirty years of age, who are constantly sick, is nearly 16 per 1,000. In the French army, the mean sick in hospital are 29 per 1,000 present ; in both hospital and infirmary, 50 ; in the Prussian, 44 (in 1876 only 25.5) ; in the Austrian, 45 ; in the Belgian (1859), 54.2 ; in the Portuguese (1851- 53), 39.4. The number of daily sick has, of course, a wide range ; sometimes an hospital is almost closed, at other times there may be more than 100 sick per 1,000, of strength. (c) Number of Days spent in Hospital pter head in each 1,000 of Strength. — The number of days' service of a battalion 1,000 strong in a year would be of course (1,000 x 365 =) 365,000. If we assume the average number of sick to be 39^ per 1,000, there are lost to the State (39^ x 365 =) 14,- 417 days' service per annum, or 14| days per man. As already said, it is difiicult to compare the sickness of soldiers and civiUans, but the above amount seems large when we remember that, in the friendly societies, the THE EFFECTS OF MILITARY SERVICE. 287 average sickness per man per annum (under forty years of age) is less tlian seven days. Mean Duration of Gases of Illness. — The number of days each sick man is in hospital (mean duration of cases) is rather greater (17.8, average of 10 years, 1870-79), as the number of admissions is below the strength. It can be most easily calculated as follows : multiply the mean daily number of sick (sick jDopulation) by the number of days in the period, and divide by the cases treated. The number of " cases treated " is the mean of the admissions and discharges in the period. Austrian army, 17 to 18 days. [ French d la chambi'e, 3.10 days. French at home, all cases (1862-66), Prussian (1859-63) in hospitals, 18.9 7.97 days. ' days. French in hospitals only (1862-66), j Belgian, 23.6 days. 26.3 days. I Portuguese, 19 days. French in infii'mary, 12 days. I ^ (a) Mortality to Sickness. — This is, of course, a different point from that of the relation of mortality to strength. A few cases of very fatal illness may give a large mortality to cases of sickness, but the mortahty to strength may be very small. The mere statement of the ratio of mortality to sickness gives little in- formation ; what is wanted is the mortahty of each disease, and at every age. Otherwise the introduction of a number of trifling cases of disease may completely mask the real facts. When, however, the general ratio is to be determined, it must be calcu- lated in one of three ways : — ■ 1. Mortality to admissions in the time. This is, however, an uncertain plan ; a number of cases admitted toward the close of a period, and the greater part of whose treatment and mortality falls into the next period, may cause an error. 2. Mortality to cases treated ( =mean of admissions and discharges).* This is the best method of calculation. 3. Mortality to sick population, i.e., the number of deaths furnished per annum by a daily constant number of sick. This, however, must be taken in connection with the absolute number of sick in the time, and with the duration of the cases, or, in other words, with the kind of cases. The degree of mortality to the several causes of sickness was given very fully in the statistical part of the "Army Medical Department Keports," up to the year 1873, since which time the detailed returns have been discon- tinued. Calculated on the admissions, the mortality to total sickness in the ^ It has not infrequently happened that the mortality on sickness has been caleu' lated in this way : the niTmber of sick remaining in hospital at the commencement of the period, say a year, are added to the admissions in the year, and the mortality is calculated on this number. At the end of the year a certain number of sick remaining in hospital are carried on to the next year, and added to the admissions of that second year for the calculation of the mortality of that year. In this way they are counted twice. This has been done in calculations of weekly mortality, and in this way the same sick man has been made to do duty as a fresh case many times over. This is to be avoided by either calculating on the admissions, or by considering half the "remain- ing" at the beginning to belong to the previous period, and half the " remaining " at the end of the period to belong to the following period, or, what is the same thing, taking half the admissions and half the discharges in the period as representing the " cases treated " in that time. i!S8 PRACTICAL HYGIENE. English army at home is a little above the mortality to strength, or about 10.2 per 1,000 per annum (1870-79). In 1880 the ratio was 7.6. In the Prussian army it was 7.25 (years 1846-62) ; in 1872 it was 7.7.' Causes of Sickness. The causes leading men to go into hospital are, of course, veiy different from those which produce mortality. For example, admissions from phthisis will be few, mortality great ; admissions from skin diseases nu- merous, mortality trifling. Taking the most common causes of admission in the order of frequency, we find — 1. Venereal Disea-^'es. — Under the term Venereal, all diseases, immediate or remote, resulting from sexvial intercourse, are included. Secondary as well as primary syphilis ; stricture and orchitis, as well as gonon-hoea, etc. ; also a few cases not strictly venereal. The primary venereal forms are, however, of the most importance. In stations under the Contagious Diseases Act, 1,000 men give 67 ad- missions from primary venereal sores and 82 from gonorrhoea (average of 11 years 1870-80). In stations not under the Act, the amounts have been, respectively, 107 and 100. There are other admissions from secondary and tertiary syphiHs, which somewhat increase the total admissions. We have no certain facts with w'hich we can comjDare the sj'philitic dis- ease of the civil population with that of the army. The amount among the ci\il population at large is reaUy a matter of conjecture. But whether it is greater or less than that of the army does not affect the result drawn from the above figures, viz., that there is an appalling loss of ser\ice every year from the immediate or remote effects of venereal disease.^ It should be understood, also, that the action of sj'philis is long con- tinued. Many soldiers die at Netley ^ from various diseases, whose real affection has been sji^hilis, so that the influence of this cause is very imper- fectly indicated by the number of admissions and ser^dce lost under the head of s^^j^hilitic disease only. 2. General Diseas^es. — The imjDortant diseases included under this class give about one-fourth of the total admissions, or about 199 per 1,000 (1870-80). (a) Eruptive fevers are not very common, about 5 per 1,000, Smallpox is checked by vaccination ; measles and scarlatina are not frequent. (b) Paroxysmal fevers (most of which have been contracted out of Eng- land) give about 13 per 1,000. (c) The continued fevers are more common, but their frequency is lessening. There is no doubt that tyi^hoid is the chief, perhaps almost the only fever besides febricula which is now seen. Spotted typhus is at pres- ent uncommon, but does occasionally occur. The continued fevers cause about 20 admissions per 1,000 of strength. Of late years there have been some cases of cerebro-spinal meningitis. ' For numerous statistical details of foreign armies, see Roth and Lex, op. cit., vol. iii., p. 411 et seq. " The order issued in 1873, directing stoppages to be made from men in hospital af- fected with venereal disease, was a most unfortunate one, as giving every inducement for the concealment of disease. Happily it has now been rescinded. 3 Professors Maclean and Aitken, of the Army Medical School, are both very much impressed with the frequent occurrence of marks of continued and dominant syphilitic action in the bodies of men who die from what are considered other diseases. THE EFFECTS OF MILITAEY SERVICE. 289 (d) Eheumatism gives 46 cases per 1,000 of strength. 3. Accidents give the next greatest number ; mean (1870-1880) 107 ; range from 65 to 114 per 1,000. 4. Diseases of the Digestive system follow, with nearly the same num- ber, about 107 ; range from 96 to 122. 5. Cutaneous diseases give a mean of 104 ; range from 92 to 123. 6. Respiratory diseases (not including Phthisis) give a mean of 85 per 1,000 ; range from 76 to 103. 7. Diseases of the Eye, mean 16, with little variation. 8. Diseases of the Circulatory system, 14. 9. Phthisis, 13, with range between 11 and 14. 10. Nervous system, 12, with a range between 11 and 14. 11. The remaining diseases of numerous smaller items, such as those of the generative {venereal excluded), locomotive, urinary [gonorrhoea ex- cluded), etc. As almost all details of these different groups are now omitted from the "Army Medical Reports," it is difficult to discuss their causation and possi- ble diminution. There is no room for doubt that the venereal admissions could be greatly lessened ; so also could the admissions from fever, which have in fact been already reduced from 60 to 22 per 1,000 of strength ; in 1879 and 1880 they were only 16 and 17 respectively. The large class of integu- mentary diseases would probably admit of reduction. What is the exact nature of the phlegmon and ulcers which form so large a proportion of the admissions ? Ti'ifling as the cases are, they form a large aggregate, and a careful study of their mode of production might show how they might be diminished. Probably, however, these are mere conventional terms, under which a number of trifling cases are conveniently recorded, but a com- plete analysis of the returns of one year under phlegmon would be desira- ble. So also of all the other classes, it may be concluded that an active medical officer might succeed in reducing the cases of rheumatism, bron- chitis, and dyspepsia.' Many cases of acute respiratory diseases are pi'O- duced by exposure on guard, especially by the passage into and from the hot close air of the guard-room to the ojDen air on sentry duty. Good ad- ditional overcoats, means of drying the clothes, and proper ventilation of the guard-rooms, would probably lessen the cases of bronchitis and pleu- risy. Sickness in Military Prisons. — The admissions into hospital in the mili- tary prisons do not appear to be great ; they have varied per 1,000 of ad- missions of prisoners from 316 (in 1851) to 725.5 in 1863.'* Calculated on the mean strength, the result is as follows : — In 1863, the daily average number of prisoners was 1,064 ; the admissions for sickness, 722 ; the mean daily sick, 21 ; the mortality, 0. These numbers give 725.5 admissions^ and 19.74 mean daily sick per 1,000 of strength. Prisoners are healthier than their comrades at duty in the same garrisons where the prisoners are under sentence. ' It is right, however, to say that no medical officer ought to sacrifice his men in the slightest degree for the purpose of appearing to have a small sick list and an empty lios- pital. There is a temptation in that direction which we have to guard against, and to remember that the only question to be asked is, What is the best for the men ? not, What will make the best appearance ? "^ Report on Prisons for 1863, p. 24. Vol. II.— 19 290 PRACTICAL HYGIENE. SECTION m Such, then, being the amount of mortality and sickness at home, it may- be concluded that the soldier at present is not yet in so good a condition of physical health as he might be ; and we can confidently look to future years as likely to show a continuance in the improvement now going on. In future years, however, the new system of limited service will render it difficult to trace the progress in the infantry. Health is so inextricably blended with all actions of the bod}^ and mind, that the medical officers must consider not only all j)hysical but all mental and moral causes acting on the men under their charge. The amount of work, the time it occupies, its relation to the quantity of food, the degree of exliaustion it produces, the number of nights in bed, and other points of the like kind ; the mental influences interesting the soldier, or depressing him from ennui ; the moral effect of cheerfulness, hope, discontent, and despondency uj)on his health, as well as the supply of water, air, food, clothing, etc., must be taken into account. And just as the body is ministered to in all these ways, so should there be ministra- tion of the mind. It is but a partial view which looks only to the body in seeking to improve health ; the moral conditions are not less important ; without contentment, satisfaction, cheerfulness, and hope, there is no health. Hygiene, indeed, should aim at something more than bodily health, and should indicate how the mental and moral qualities, essential to the partic- ular calling of the man can be best developed. How is a soldier to be made not merely healthy and vigorous, but cour- ageous, hopeful, and enduring ? How, in fact, can we best cultivate those martial quaHties which fit him to endure the hardships, vicissitudes, and dangers of a career so chequered and perilous ? Without attempting to analyze the complex quality called courage, — a quality arising from a sense of duty, or love of emulation, or fear of shame, or from physical hardihood, springing from familiarity with and contempt of danger, — it may well be believed that it is capable of being lessened or increased. In modern armies, there is not only little attempt to cultivate courage and seK-reliance, bvit the custom of acting together in masses and of dependence on others, actually lessens this. It is, then, a problem of great interest to the soldier to know what mental, moral, and physical means must be used to strengthen the martial quahties of boldness and fortitude. The Enghsh army has never been accused of want of courage, and the idea of pusillanimity would seem impossible to the race. But drunken^ ness and debauchery strike at the very roots of courage ; and no army ever showed the highest amount of martial qualities when it permitted these two vices to prevail. ' In the army of Marlborough, the best governed ' There are many sober and excellent men in the army But as a rule, the English soldier cannot be depended upon under any circumstances, if he can get drink. Well does Sir Ranald Martin, say, " Before that terrible vice can be overcome, something far more powerful than medical reasoning on facts, or the warnings of experience founded on them, must be brought into active operation. Discipline must still further alter its direction :^in place of being active only to punish wrong, it ought and must be exerted further and further in the encouragement to good conduct."— Ranald Mar- tin, Tropical Climates, p. 263. THE EFFECTS OF MILITARY SERVICE. 291 army we ever had, and the most uniformly successful, we are told that the " sot and the drunkard were the objects of scorn." To make an army per- fectly brave, it must be made temperate and chaste. Good health and physical strength, by increasing self-confidence, in- crease courage ; and self-reliance is the consequence of feeling that, under all circumstances, we can face the dangers and difficulties that present themselves. Few wiser words were ever wi-itten than those by William Fergusson/ at the close of his long and eventful service. " Of the soldier's life within these barracks," writes Fergusson, "there is much to be said, and much to be amended. To take his guards, to cleanse his arms, and attend parade, seems to comprehend the sum total of his existence ; amusement, instruction beyond the drill, mihtary labor, and extension of exercises, would appear, until very recently, to be im- thought of ; as it is impossible that the above duties can fully occupy his time, the u'ksomeness of idleness, that most intolerable of all miseries, must soon overtake him, and he will be driven to the canteen or the gin- shop for relief. " Labor in every shape seems to have been strictly interdicted to the soldier, as water for his drink. All, or nearly all, must have been bred to some trade or other before they became soldiers ; Ibut there is work for them no longer. Labor (the labor of field-works and fortifications) strengthens the limbs and hardens the constitution, but that is never thought of in our mihtary life at home ; so thought not the ancient Romans, whose military highways still exist, and who never permitted their soldiers to grow ener- vated in idleness duiing peace. Better, surely, would it be that every one should work at his own craft, or be employed on the public works, in regu- lated wholesome labor, than thus to spend his time in sloth and drunken- ness. But his exercises, without even going beyond the barrack premises, may be made manifold — running, wi-estling, gymnastic games of every kind, swimming, leaping, pitching the bar, the sword exercise (that of the artillery), all that hardens the muscles and strengthens the hmbs, should be encouraged ; and when the weather forbids out-door pastimes, the healthy exercise of single-stick, in giving balance and power to the body, quickness to the eye, and vigor to the arm, may properly be taken as a substitute for the drill which, after the soldier has been perfected in his exercise, is al- ways felt to be a punishment. So is the unmeaning evening pai-ade and perpetual roll-calling. "Foot-racing too, the art of running, so little practised, and so su- premely useful, should be held amongst the qualities that constitute mili- tary excellence. It was so held at the Isthmian games of ancient Greece, and deserves a better place than has hitherto been assigned to it in the mihtary pastimes of modern Britain. In our school-books we are told that the youth of ancient Persia were taught to launch the javelin, to ride the war-horse, and to speak the truth. Let the young British warrior be taught to use his limbs, to fire ball-cartridge, to cook his provisions, and to drink water. The tuition may be less classical, but it will stand him in far better stead during every service, whether at home or abroad. "Regular bodily pleasurable exercise has been said to be worth a host of physicians for preserving military health ; and occujDation without dis- tress or fatigue is happiness. The philosopher can make no more of it ; and every idle hour is an hour of irksomeness, and every idle man ' Notes and Recollections of Professional Life, 1846, p. 49. 292 PRACTICAL HYGIENE. is, and must be, a vicious man, and to a certain extent an unhealthy one." In many of the foreign stations of the British army, excellent oppor- tunities exist for both occupying the men and developing their spiiit. All history teaches us that a hunting race is a martial one. The remarkable fighting qualities of the Enghsh, as drawn in Fi'oissart's " Chronicles," were owing to the fact that at that time they were " a nation of hunters," and trained from infancy to face dangers alone. In India there ai'e many places where men could not only be allowed to hunt, but where such permission would be the greatest boon to the inhabitants. The Enghsh ai'my has hitherto offered but few incentives to good con- duct, and scanty encotu-agement for the cultivation of martial qualities. Men must have rewards, and feel that earnest endeavor on then- part to become in all respects better soldiers is neither overlooked nor unre- warded. The new order of things introduced by Lord Cardwell seems likely to open up means of progress for men who can acquii-e knowledge and desei've advancement. The cviltivation of the martial qualities of the soldier is in reality a part of hygiene considered in its largest sense, biit this part of hygiene must be studied and cai-ried into eft'ect by the combatant oflScers. Let us trust it mav not be long before they seriously study and endeavor, by precept and example, to promote the formation of those habits of boldness and endurance, and that fertility in resources, which are as necessary as techni- cal knowledge to render an ai'my the formidable instiTiment it is capable of becoming. CHAPTER IV. FOREIGN SERVICE. Tee foreign seryice of the Britisli army is perforraed in every pai't of the world, and in almost eyery latitude, and probably more than tyro-thirds of each line soldier's seryice is passed abroad. The mere enumeration of the stations is a long task ; the description of them would demand a large volume. In this short chapter, to give a few general statements as to ehmate and geolog;^', and the past and present medical history of the sta- tions, only can be attempted ; such an outhne as may giye medical officers a sort of iDrief summary of what seems most important io be knoTsm. Detailed and excellent accounts of most of the foreign stations exist, either in the independent works of army sui'geons, such as those of IMar- shall, Hennen, Davy, and many others, or in reports di'awn up for Govern- ment, and pubhshed by them. In the early " Statistical Eeports of the Medi- cal Department of the Army,'' short topographical notices of the stations were inserted ; they are models of what such reports should be, and must have been dra^yn up by a master in the art of condensatiom In the "Annual Eeports" now pubhshed many excehent topographical descriptions "^ill be found ; and some of the Indian Governments have published complete descriptions of all their stations. In the "Bombay Transactions," the 'Madras Medical Journal, and the "Bengal Indian Annals" are very full ac- counts of almost every station that has been, or is, occupied by European troops in India. Finally, in the "Indian Sanitary Eepoi't" is much impor- tant information on the meteorologv' and topography of the present Indian stations. Young medical officers first entering on foreign service are strongly advised to study these accounts of the stations in the command where they are serving ; it will not only give them interest in their service, but will aid them in their search how loest to meet the chmatic or sanitary conditions which affect the health of the men under their char-79 (10 years). . 1880 3.72 8.33 7.76 12.(50 7.65 6.19 10.41 3.88 11.96 16.81 12.18 27.40 CrPBus. ' This station was first occupied in 1878. It is an island in the Levant, about 50 miles from the nearest maiidand, nnd 240 from Port Said at the entrance of the Suez Canal. Size, 90 miles by 40 ; area, about 4,000 square miles ; civil population, about 185,000 (in 1881). Our information about the climate is as yet imperfect, but it ajopears to resemble that of Malta, with greater rainfall. The stations at present occupied are Nicosia (592 feet above the sea), as headquarters ; Polymedia camp (400 feet), by the bulk of the troops, from October to May ; and Mount Troados (5,720 feet), from Maj' to Octo- ber. The average strength (1880) was 443 officers and men. The mean ' Dr. Notter analyzed, in 1872, fourteen of the tank waters of the different forts, and found the condition of the water to be satisfactory. FOREIGIS" SERVICE. 303 temperature at Polymedia during the cooler season (November to May in- clusive) is about 59° to 60°; of Mount Troados (May to September inclu- sive), about 64° Fahr. The rainfall appears to be considerable, for in seven months (November to May) in 1880, 31.81 inches fell, of which no less than 12.26 were recorded in December alone. The number of rainy days in the seven months was 58. The prevailing wind would appear to be N. W. On the first occupation in 1878 there was a great amount of sickness, chiefly from paroxysmal fever. This appeared to arise from the unsuitable sites selected for the temporary camps and the turning up of soil infil- trated with organic matter. During the five months (2J:th July to 31st December, 1878) there were, out of a strength of 894 non-commissioned officers and men, 3,931 admissions for disease and 36 deaths, or at the rates of 4,397 and 40.3 per 1,000 respectively. Expanding these to an annual rate, they amount to 10,094 admissions and 92 deaths per 1,000 of strength, an enormous amount. Eighty-four per cent, of the admissions and 61 per cent, of the deaths were due to fever, almost all jDaroxysmal (so- called remittent), only 14 admissions (actual number) and 2 deaths being due to enteric. In 1879 (strength 660) there was a great improvement — the ratios being 1,470 admissions and 21 deaths per 1,000, 35 per cent, of the admissions and 50 per cent, of the deaths being still due to paroxysmal fever. There were 3 deaths from dysentery, against 4 in 1878. In 1880 (strength 443) the total admissions were 1002.2 and the deaths only 2.26 per 1,000 strength. Paroxysmal fevers gave only 196.4 of admissions and no deaths. The only death in the command was from pulmonary extrava- sation, and occurred out of hospital. On the whole, we may consider the station healthy if proper precautions are taken : for, if we omit the ad- missions for injuries, the ratio for disease in 1880 was only 884.8 per 1,000 of strength, and of these 383. 7 were venereal or the sequelfe of venereal disease. The invaliding in 1880 amounted to 18.07 per 1,000, one-fourth of which was due to syphilis ; the number constantly sick was 53.27 per 1,000, of whom 4.45 were cases of injury and 28.69 venereal or its sequelfe ; and the average duration of each case of sickness was 19.45 days. The possibility of placing the troops in the hills at a considerable ele- vation (IVIount Troados, 5,720 feet) dimng the hottest months, will always be a great advantage to this station. SECTION n. WEST INDIES. The history of sanitary science affords many striking instances of the removal of disease to an extent almost incredible, but no instance is more wonderful than that of the West Indies. Formerly service in the West Indies was looked on as almost certain death. It is little over sixty years since the usual time for the disappearance of a regiment 1,000 strong was five years. Occasionally in a single year a regiment would lose 300 men, and there occurred from time to time epochs of such fatality that it was a common opinion that some wonderful morbid power, returning in cycles of years — some wave of poison — swept over the devoted islands, as sud- den, as unlooked-for, and as destructive, as the hurricanes which so sorely plague the ** Golden isles set in tlie silver sea." 30 i PRACTICAL HYGIENE. "Wliat gave countenance to this liypotbesis was, that sometimes for months, or even for a year together, there would be a period of health so great that a regiment would hardly lose a man. But another fact less noticed was not so consistent with the favoiite view. In the very worst years there were some stations where the sickness was trifling ; while, more wonderful still, in the worst stations, and in the worst years, there were instances of regiments remaining comparatively healthy, while their neighbors were Hterally decimated. And there occurred also instances of the soldiers d;\-ing by scores, while the health of the civil inhabitants in the immediate A-icinity remained, as usual. If anything more wei*e wanted to show the notion of an epidemic cycle to be a mere hypothesis, the recent medical history of the West Indies would prove it. At present this di-eaded service has almost lost its ter- rors. There still occur local attacks of yellow fever, which may cause a gi'eat mortality ; but for these local causes can be found ; and otherwise the stations in the "West Indies can now show a degree of salubrity almost equalling, in some cases surpassing, that of the home sei-vice. The causes of the production, and the reasons of the cessation, of this great mortality are found to be most simple. It is precisely the same lesson which we should grow weary of learning if it were not so vital to us. The simplest conditions were the destructive agents in the West Indies. The years of the cycles of disease were the j-ears of overcrowding, when military exigencies demanded that large garrisons should hold the islands. The sanitary conditions at all times were, without exception, in- famous. There was a great mortality from scorbutic dysentery, "which was al- most entii-ely owing to diet.' Up to within a compai'atively late date, the troops were fed on salt meat three, and sometimes five, days a week, and the supply of fresh vegetables was scanty. It required all the influence of Lord Howick, the then Secretary at War, to cause fresh meat to be issued, though it had been pointed out by successive races of medical officei-s that fresh meat was not only more wholesome, but was actually cheaper. The result of an improvement in the diet was manellous ; the scorbutic dysenteiy at once lessened, and the same amount of mortahty from this cause is now never seen. Another cause of dysentery was to be found in the water, which was impure from being drawn from calcareous strata, or was turbid and loaded with sediment. The substitution of rain-water has sufficed in some stations to remove the last traces of dysentery. If the food and water were bad, the air was not less so. Sir Alex- ander TuUoch has given a picture of a single ban-ack at Tobago, said to be the "best in the whole Windward and Leeward Command,"'' the figures of which tell their own tale. Barrack at Tobago in 1826. — Superficial space per man, 22^ feet ; breadth, 23 inches ; cubic space, 250 feet. The men slept in hammocks, touching each other. In these barracks, crowded as no ban-acks were even in the coldest climates, there was not a single ventilating oj)ening except the doors and windows ; the air was fetid in the highest degree. With this condition of atmosphere it is im- possible not to bring into connection the extraordinary amount of phthisis which prevailed in the soft and equable climate of the West Indies. There ' This is pointed out in the Statistical Beport (1838) on the West Indies, by Tulloch and Balfour ; and it is believed that the improvement in the diet was in a great meas- ure owing to these gentlemen. '■' Eeport, 1838. FOEEIGN SERVICE. 305 was more phthisis than in England, and far more than in Canada. The first great improvement was made in 1827, when, iron bedsteads being in- troduced, each 3 feet 3 inches wide, greater space was obHged to be given to each man. Every arrangement for removal of sewage was barbarous, and in every barrack sewage accumulated round the buildings and was exposed to heat and air. When yellow fever attacked a regiment, every stool and evacua- tion was thrown into the cesspools common to all the regiment ; and in this way the disease was propagated with gi'eat rapidity, and was locahzed in a most singular manner, so that a few hundred yards from a barrack, where men were dying by scores, there would be no case of fever. In spite of this, it was many years before the plan of at once evacuating a bar- rack where yellow fever prevailed was adopted. The barracks themselves were usually very badly constructed, and when in some cases the architects had raised the barracks on arches from the ground, in order to insure perflation of air below the buildings, the arches wer% blocked up or converted into store-rooms ; and the bari'acks, with spaces thus filled with stagnant air beneath them, were more unhealthy than if they had been planted on the ground. The locahties for barracks were often chosen without consideration, or for military reasons,' into which no consideration of health entered. Al- most all were on the plains, near the mercantile towns, where the soil was most malarious, and the climate hottest and most enervating. Malarious fevers were, therefore, common. To all these causes of disease were added the errors of the men them- selves. For the officers there existed, in the old slave times, the greatest temptation. A reckless and dangerous hospitality reigned everywhere ; the houses of the rich planters were open to all. A man was deemed churlish who did not welcome every comer with a full wine, or more often a brandy, cup. In a climate where healthy physical exertion was deemed impossible, or was at any rate distasteful, it was held to be indispensable to eat largely to maintain the strength. To take two breakfasts, each a substantial meal, was the usual custom ; a heavy late dinner, frequently followed by a sup- per, succeeded ; and to spur the reluctant appetite, glasses of bitters and spirits were taken before meals. The private soldiers obtained without difficulty abundance of cheap rum, which was often poisoned with lead. Drunkenness was almost uni- versal, and the deaths from delirium tremens were frequent and awfully sudden. The salt meat they were obhged to eat caused a raging thirst, which the rum-bottle in reality only aggravated. To us these numerous causes seem sufficient to account for everything, ' The history of the old St. James's Barracks in Trinidad is too remarkable to be passed over. It was determined to build a strong fort — a second Gibraltar — on the lower spurs of the hills overlooking the plain where the barracks now stand. When the works had been carried on for some time, it was discovered that they could not hold the troops. The barracks were then ordered to be placed on the plain, under cover of the guns of the fort. Before the fort was quite finished, it was fotmd to be so unhealthy that neither white nor black men could live there, and it was abandoned. The barrack, it is said, was not then commenced ; yet though the reason for placing it in that spot had gone, it was still built there, on a piece of ground near two marshes (Cocorite and the Great Western Marsh), below the general level of the plain, and ex- posed to the winds from the gullies of the neighboring hills. Yet this bad position, so fruitful of disease, was in reality less injurious than the bad local sanitary arrange- ments of the old St. James's Barrack itself. Vol. II. -20 306 PRACTICAL HYGIENE. but in former days an easier explanation was given. It was held to be the climate ; and the climate, as in other parts of the world besides the West Indies, became the convenient excuse for pleasurable follies and agreeable vices. In order to do away with the effects of this dreaded climate, some mysterious power of acclimatization was invoked. The European system required time to get accustomed, it was thought, to these climatic influ- ences, and in order to quicken the process various measures Avere pro- posed. At one time it was the custom to bleed the men on the voyage, so that their European blood might be removed, and the fresh blood which was made might be of the kind most germane to the West Indies. At other times an attack of fever (often brought on by reckless drinking and exposure) was considered the grand preservative, and the seasoning fever was looked for with anxiety. The first statistical report of the army swept away all these fancies, and showed conclusively that instead of prolonged residence jaroducing acclimatization and lessening disease, disease and mortality increased regularly with every year of residence. The progress of years has given us a different key to all these reftilts. It is now fully recognized that in the West Indies, as elsewhere, the same customs will insure the same results. Apart from malaria, we hold our health and life almost at will. The amount of sickness has immensely decreased ; occasionally in some stations which used to be very fatal (as at Trinidad) there has not been a single death in a year among. 200 men. Among the measures which have wrought such marvels in the West Indies have been — 1. A better supply of food ; good fresh meat is now issued, and vege- tables, of which there is an abundance everywhere. 2. Better water. 3. More room in barracks, though the amount of cubic space is still small. 4. Eemoval of some of the stations from the plains to the hills ; a meas- ure which has done great good, but which can explain only a portion of the improvement. The proper height to locate troops is by most army surgeons considered to be at some point above 2,500 feet. 5. Better sewage arrangements, and more attention generally to sani- tary conservancy. 6. A more regular and temperate life, both in eating and drinking, on the part both of officers and men. 7. The occupancy of the unhealthy places, when retained as stations, by black troops. 8. A better dress. It is only, however, within recent years that a more suitable dress has, at the instance of the late Sir J. B. Gibson, for- merly Director-General, A.M.D., been provided for the West Indian Isl- ands. The army stations in the West Indies are Jamaica, Barbadoes, Trinidad, St. Vincent ; the last three being included in the term " Windward and Leeward Command." British Guiana, on the mainland, is part of this command. There are small parties of artillery and some black troops in Hondm-as and the Bahamas. The period of service is now three or four years : formerly it was eleven or twelve, but this was altered after the first statistical report. Usually the Mediterranean regiments pass on to the West Indies, and subsequently to Canada. The total number of men serving in the West Indies is now very small. The proper time for arriving in the West Indies is in the beginning of FOREIGN SERVICE. 307 the cold season, viz., about the beginning of December, when the hurricanes and autumnal rains are usually over. Jamaica. Present strength of white garrison, 200 to 300 ; black troops, 500 to 600. Population of island estimated at 560,000. A range of lofty hills (Blue Mountains) divides Jamaica into two parts, connected by a few passes. The troops were formerly stationed chiefly in the south plains, at Kingston (30,000 inhabitants). Port Royal, Spanish Town, Up-Park Camp, Fort Augusta, etc. After the Maroon war in 1795 some troops were sta- tioned at Maroon Town (2,000 feet above the sea) on the north side, and at Montego Bay. Subsequently Stony Hill (1,380 feet above the sea), at the mouth of one of the passes, was occupied. Since 1842 some, and now nearly all the troops, are at Newcastle, in the hills, 4,000 feet above the sea, Avith detachments at Kingston and Port Eoyal. The other stations are now disused for white trooiDS. The sanitary condition at Newcastle was formerly not good ; the sewage arrangements are very imperfect ; it is now somewhat improved. Climate. — The climate is very different at the different stations. At Kingston (sea-level) — temperature, mean of year = 78° ; hottest month, July, mean= 81°. 71 ; coldest month, January, mean = 75°. 65 ; mean yearly fluctuations = 6°. 06. Undulations trifling. The climate is limited and equable. At Newcastle the mean annual temperature is about QQ>° ; hottest month, August = 67°. 75 ; coldest month, February = 61°. The diurnal range is considerable, but the annual fluctuation is trifling (about 6°). The mean of the year is therefore much lower than on the plains ; the ampli- tude of the yearly fluctuation about the same ; the diurnal change greater. Humiditif.— This is considerable in the plains — often from 80 to 90 per cent, of saturation =7 to 9 grains of vapor in a cubic foot. At Newcastle the mean yearly dew-point is about 60° ; the amount of vapor in a cubic foot of air is 5.77 ; the mean yearly relative humidity is 68 per cent, of saturation. Bain. — Amount on the plains = 50 to 60 inches, in spring and autumn, viz., April and May, and October and November. Showers in July and August. Wi7ids. — Tolerably regular land winds at night, and sea breezes in the hot and dry months during the heat of the day. The central chain of mountains turns the northeast trade wind, so that it reaches the south side diverted from its course ; from December to February the wind is often from the north, and brings rain and fogs ("wet northers"). The southwest wind in April and May is very moist. The hurricane months are fi'om the end of July to the beginning of November. The chmate in the plains is therefore hot, equable, and humid. Health of the Black Civil Population. Of the specific diseases, small-pox and the other exanthemata are com- mon. Spotted typhus is said to be unknown ; typhoid is said to be un- common, but is probably more common than is supposed. Influenza has prevailed- at times, and also the so-called dandy or polka (Dengue). Cholera has prevailed severely. Malarious fever is common over the whole of the south plains. Yellow fever is common, though less frequent and severe among the blacks than the whites. Dysentery is common, 308 PEACTICAL HYGIENE. though it has always been less frequent than among the troops. Organic heart disease is frequent. Liver diseases are uncommon. Spleen disease, in the foi-m of leucocythsemia, is common among the blacks (Smarda), Gout is said to be frec^uent, and scrofula and rickets to be infrequent. Syphilis is not common, but gonorrhoea is. Cancroid of the skin and ele- phantiasis of the Ai-abs (Pachydermia) ai-e common. Leprosy is also seen. Health of the Troops. Li the years 1790-93 the annual mortahty of the white troops varied in the diflferent stations from 111 (Montego Bay) to 15.7 per 1,000 of strength at Stony Hill (1,380 feet above sea-level). In the years 1794-97 the mortality was much greater ; the most unhealthy regiment in the plains lost 333 ; the most healthy, 45.4 per 1,000 of strength ; at the hill station of !Maroon Town (2,OoO feet) the mortality was, however, only 15.6 per 1,000. Li the years 1817-36 the mean mortality was 121.3 ; the mean of the four healthiest years gave 67, and of the four unhealthiest years 259 per 1,000. The causes of death in these twenty years were — Fevers 101.9 per 1,000 of strength. Lung diseases 7.5 " " Bowel complaints 5.1 " " Brain disease 2.6 " " Liver diseases 1 " " Other complaints 3.2 121.3 The admissions in these years were 1,812 per 1,000 of strength. In 1837-55 the follo'o-ing were the mean results : Mortality per 1,000 of strength — white troops, 60.8; black troops, 38.2. Admissions per 1,000 white troops, 1,371 ; black troops, 784. So that the mortality had declined one-half. In 1864 the mortahty- was much below the home standard. In 1867 it ran up neai'ly to the old amount, from the prevalence of yellow fever, which in that year prevailed again in Newcastle, and caused a gi-eater loss than it had done in 1860. The statistics of the white troops are — Loss of Strength per Annum. 1,000 per Loss of Service per 1,000 per Annum. Years. Total Deaths. Deaths from Disease. Invalids. Admis- sions. 1 Days in Mean Hospital in Daily Sick. ' each Sick j Man. 1861-70 (10 rears) 1871 Highest in 1867 20.36 13.51 71.09 13.51 69.80 5.88 27.6 30.4 45.91 930.8 1192.9 40.63 32.43 78.95 16.10 15.17 21.95 Lowest inl864 In 1875 the death rate was. 7.35 12.99 Since 1875 no separate return is furnished in the A.]VLD. Eeports. An increase in admissions and mortality occurred in 1865 and 1866, owing to the exposure of the troops in the time of the negro distm-bances, and their subsequent partial location on the plains. FOEEIGN SERVICE. 309 Before this period Jamaica contrasted favorably even with home service, and particularly so vv^ith India. A decrease of admissions in 1859-64 was chiefly owing to the compara- tively small number of cases of paroxysmal disease ; a decline consequent on the removal of most of the troops from the plains (in 1859 Newcastle gave 29.1 admissions, and Port Koyal, on the plain, 443.5 per 1,000 of strength, from malarious disease). la 1863 some white troops were sent to Up-Park Camp, and furnished a large number of malarious cases (547.6 admissions per 1,000 of strength), while at Newcastle they were only 48 per 1,000. The decrease in the mortality in the years 1859-64 was owing to lessened fever and dysentery. Among the black troops there is now greater sickness and mortality than among the whites ; the mortality in 1837-55 was 38.2 per 1,000 ; in 1859-65 it was 27.33 ; in 1866, 23.03 ; in 1875 it was only 14.67. There is among these troops a large mortality from paroxysmal fevers, phthisis, and diseases of the aUmentary canal ; and it is evident that their condition requires a close examination. The mortality of the white troops shows a marked increase vrith age. The following seem to be the most important points connected with the white troops which require notice. It is impossible to avoid paroxysmal fevers without placing all the troops in the hills, and it is very desirable Newcastle should be made the only station for white troops. The possibility of yellow fever occurring at an elevation of 4,000 feet was shown by the appearance of yellow fever at Newcastle in 1860 and 1867. In 1860 occurred the remarkable instances of contagion on board the ships Icarus and Imaum described by Dr. Bryson. Whether yellow fever was imported into Newcastle or not was a subject of discussion ; it certainly appears probable that it was carried there ; but the important point for us is that mere elevation is not a perfect security. There were, however, only a small number of cases. In 1867, when yellow fever again appeared at Newcastle, it was imported, apparently, from Kingston and Up-Park Camp. In the returns for a number of years, cases were returned as " continued fever ; " it had never been clearly made out whether or not these were cases of tj^Dhoid fever until 1873-4, when a sharp epidemic occurred at New- castle. Formerly there was a large number of cases of phthisis ; phthisis is now uncommon ; in 1817-36 lung diseases (almost entirely phthisis) caused 7.5 deaths per 1,000 of strength, or more than in England. In 1859-66 the ratio was only 1.42 per 1,000 of strength ; and in 1861, out of 636 men there was not a single death, though four men were sent home with con- sumption. In 1865 there was no death ; eight men were sent home. At Newcastle there occurred for some years an excess of affections of the alimentary canal, chiefly indigestion ; at present these have lessened, but it would he important to make out the cause. In 1860 there was not a single admission from dysentery at any station. In the worst times in Jamaica it was always remarked that there was rather a singular exemption from acute liver disease ; very few cases appear in the returns under hepatitis ; whether this is a matter of diagnosis, or whether there was reaUy an immunity compared with 'India or the Mauri- tius, is a question of great interest which cannot now be solved. At pres- ent, liver disease unconnected with drinking is uncommon. There is still too much drinking, and the medical officers have strongly advised the issue of beer instead of tht daily diam. 310 PRACTICAL HYGIENE. Venereal diseases have never prevailed much in Jamaica , they have caused, on an average, from 70 to 90 admissions per 1,000 of strength. In 1862 there were only 47 admissions per 1,000 of strength. On an average in 1859-65, enthetic diseases gave 118 admissions per 1,000. This is- owing to the connection usually formed between the black women and the soldiers, and to a lessened amount of promiscuous intercourse. The history of the years 1865-67 shows that the greatest care and the most judicious aiTangement of the men is necessary to guard against a recurrence of the old evils. The black troops gave a mortality of 24.6 per 1,000 (mean of ten years, 1861-70), especially from phthisis. Trinidad. Strength of garrison, 200 men. Civil population (in 1881), about 153,000. Geology. — Tertiaiy formation of miocene age ; central range of hills is an indurated formation of cretaceous age ; the northern littoral range con- sists of micaceous slates, sandstones, limestones, and shales. The highest hill is 3,012 feet ; the central hiU (Tamana) is 1,025 ; one-seventeenth of the island is swampy. Climate. — Temperature of the plains : Mean of year about 79'^. 3 ; coldest month, January = 78' ; hottest month, May = 81°. 5 ; next hottest, October = 80°.4. Mean annual fluctuation, 3°. 5. The climate is therefore very equable and Hmited. There are, however, cold winds from the hills blow- ing over small areas, Hijgromelrij. — Mean dew-point, 75^.1 ; mean relative humidity = 81 per cent, of saturation ; mean weight of vapor in a cubic foot = 9.4 grains ; most humid month is May, as far as the amount of vapor is concerned. Month Avith greatest relative humidity, August. Winds from east to northeast and southeast. "West winds rare, and oppressive. Fuiin on the plains, about 60 to 70 inches. Greatest rainfall in one day, 4.67 inches. Dry season, December to May. June and July showery. Heavy rain in August, September, and October. Sanitary Condition. — St. James's BaiTack is on a depression on an allu- vial soil three miles from Port of Spain, the capital ; it is one mile from the Cocorite, and three from the Great Eastern Swamp ; the drainage, for many years most defective, is now improved, as the main sewer is carried to the sea. On many occasions yellow fever has prevailed in this barrack, and nowhere else in the island ; the last occasion was in 1858-59, and then it was proposed by Dr. Jameson (the principal medical officer) to erect bar- racks on a spot 2,200 feet above sea-level. The capital, the Port of Spain (32,000 inhabitants), is buUt at the prin- cipal outfall of the island ; it is on a low and unhealthy plain. Formerly, it was so unhealthy as to be scarcely habitable, but after being well drained and paved by Sir Ralph Woodford, it has become much healthier. This was the result of great sanitaiy efforts in a very unpromising locality, and should be a lesson for all chmates. There is still, however, much malarious disease, dysentery, and at times yellow fever ; but this last disease has occasionally been very severe at St. James's Barracks, without a single case being seen in Port of Spain, The ascent of the malaria from the barrack plain is certainly more than 500, and probably as much as 1,000 feet. FOREIGN SERVICE. 311 Diseases of Troops. — The state of health, has been and is very similar to that of Jamaica, ^\ith, however, a large percentage in former years both of phthisis and diseases of the stomach and bowels, chietiy dysentery. In the years 1817-36, the average mortahty of the white troops was 106.3 per 1,000 of strength, and of these deaths there were — From fevers 61.6 Lung diseases 11.5 Diseases of stomach and bowels 17.9 Dropsies (probably partly maLarious, parily renal) 7.7 Brain diseases (especially from intemperance) , 4.7 Liver diseases 1.1 All other diseases 1.8 106.3 As in Jamaica, the statistics of the white troops of late yeai-s tell a very different story. In 1859 there was an outbreak of yellow fever, and the deaths from disease rose to 81.27 per 1,000. In the next seven years (ending 1866) the average number was 7.48 deaths from disease per 1,000. In two years (1860 and 1865) there were no deaths. Even in 1859, when the mortahty was so large, there were only 10 deaths from yellow fever among 190 men, while there were no less than 4 deaths fi'om delirium tremens. Among the diseases in the returns, the largest item is malarious fever ; there are also cases of " continued fever," as in Jamaica ; and this term, in fact, has never been absent from the reports. Is this typhoid fever ? In all probabihty it is, as unequivocal typhoid fever does occm- in Trinidad.^ A considerable number of cases of dyspepsia are admitted ; in 1860 there were 16 cases out of 221 men, or 72 per 1,000 of strength. In 1862 there were 103 per 1,000 admissions from " digestive " diseases. Venereal dis- eases have alwavs been low ; in 1860, 1861, 1862, and 1864, there were only 49.8, 44.4, 20.6, and 63.8 admissions per 1,000 of strength. Dysen- tery is now infrequent. In 1860, out of 221 men, and 1861, out of 225 men, there was not a single case. In 1864, out of 235 men, there was only 1 case. In 1865 there were no admissions from phthisis. Phthisis is much less common, yet in some years there is still too much of it. Separate statistics are no longer available fi'om the A.M.D. Reports. It is evident that if Dr. Jameson's suggestion is acted upon, and the troops are removed to the hills, malarious fever will disappear, and yellow fever can be prevented. In such a case, if the men w-ill abstain from drinking, this island, which formerly killed rather more than 1 man in every 10 yearly, will be one of the healthiest sjDots in the world. The black troops are now less healthy than the white, having in 1859-65 an annual mortality of nearly 20 per 1,000, of which 18 were from disease. Their condition requu-es looking into. Of late years a very small number of black troops have been stationed at Trinidad. The invaliding from Trinidad is combined in the Ai-my Eeports with that of the other islands of the Windward and Leeward Command. ^ Dr. Stone's paper in the Medical Times and Gazette, February, 1860. 312 PKACTICAL HYGIENE. Barbadoes. strength of garrison, 300 to 400 men. Civil population (in 1881), 172,000. Geology. — Limestone (coralline) ; sandstone (tertiary) ; beds of bitu- minous matter and coal (tertiary), clay in parts (especially in the hilly dis- trict called " Scotland "). An open country, well cultivated, no marshes except a small one at Grteme Hall, one mile to the east of St. Ann's Barracks. The country is divided into two parts : a mountainous district termed " Scotland," and a lower country consisting of a series of five gigantic ter- races, rising with some regularity one above the other. The highest hill is 1,100 feet. Climate of the Plain. — Temperature : Mean of year, 80° ; hottest month (October), 83° ; coldest month (January), 78° ; mean yearly fluctua- tion, 5°. Climate equable and limited. Relative humidity, 70 per cent. Wind. — N.E., trade, strongest in Februaiy to May; weak in September to November inclusive ; hurricane mouth, August. Rain. — About 56 to 58 inches, on an average, but varying a good deal in the autumn chiefly, though there is rain in all months, but much less. The dry season is from December to May. Water. — Formerly supplied from wells ; it was highly calcareous. At present good water is supphed by a water company. Rain-water is also collected in tanks. Sanitary Condition. — St. Ann's Barracks are placed above one and a half mile from Bridgetown, on the sea ; the locality and the construction of the barracks have been much comj^lained of, and a position in the hills advised.' Ai'rangemeuts for sewering and the water supply were both for- merly bad ; considerable impi'ovements have been made, and, since 1862, 30,000 gallons are supplied daily to St. Ann's Barracks. It is a limestone water, containing carbonate of lime, but no sulphate of lime, and is re- markably fi'ee fi'om organic matter. The total solids are 18.72 gi-ains per gallon. The troops are still too much crowded in barracks, the allowance being under 600 cubic feet. Since 1872 new latrines (Jennings' j^attern) have been provided and the old ones closed. Formerly vegetables were very deficient in Barbadoes, and even now there is some difficulty in procuring them. They are often imported from other islands. Diseases among Cicil Population. — Yellow fever has appeared frequently, although the island is not marshy. It is not so frequent as formerly ; it used to be expected every four years. Barbadoes and Trinidad contrast greatly in the freedom fi-om marshes of the one, and the . existence of marshes and malarious diseases in the other ; yet Barbadoes has had as much yellow fever as Trinidad. Dysentery was common formerly, partly from bad water ; influenza has been epidemic several times. Barbadoes leg, or Elephantiasis of the Arabs, is frequently seen. Lej^rosy, or Elephantiasis Graecorum, is also not very uncommon. Variola and Pertussis have from time to time been very bad. Hillary, in 1766, described a " slow nervous fever," under which term ' For an extremely good and concise account of Barbadoes, see Dr. Jameson's Report in the Army Medical Report for 18G1, p. 261. FOREIGN SERVICE. 313 our typhoid fever appears to have been indicated by most writers of that period. His description is not quite clear, but resembles typhoid fever more than any other. He also speaks of " diarrhoea febrilis." Can this have been typhoid ? Dracunculus was formerly very frequent, and Hillary attributes it to the drinking-water, and states that there were some ponds the water of which was known to " generate the worm if washed in or drank." Yaws used to be common. Colica pictonum was formerly frequent. Diseases of Troops. — Yellow fever has several times been very fatal. Scorbutic dysentery, arising from the wretched food, was formerly very frequent, and appears, from Sir Andrew Halliday's work to have been very bad even in his time (1823 to 1832). From 1817 to 1836 (20 years)— Average mortahty (white troops), 58.5 per 1,000 of strength. Greatest " " 204 " " (in 1817). Least " " 18 " " (in 1823). In 1817 there were 1,654 men on the island, and yellow fever broke out. In 1823 there were only 791. Of late years, as in all the other islands, the sickness and mortality has been comparatively trifling. In 1859-65 the total deaths were 6.98 per 1,000, and in 1866 they fell to 3.28 per 1,000, which is only one-third the mortality of home service. The highest mortality of late years was in 1862, viz., 16.77 ; the average num- ber of admissions is about 1,200. In 1864 there was an outbreak of a mild fever, termed "remittent;" the nature is unknown ; no case was fatal. The increased mortality of 1862 was owing to yellow fever. It ajDpeared first among the civil population in Bridgetown, and afterward attacked the troops in the (stone) barracks. As it continued to spread, the men were moved out and placed under canvas, with the best effects. A remarkable feature of this epidemic was that the officers suffered in attacks six-fold more than the men, and had a mortality more than twenty-fold. The women also suffered three-fold more than the men. Formerly the case would have been reversed. In 1861 there were only two eleaths out of 787 men, one from phthisis and one from apoplexy ; and in 1864 there were also only two deaths (diarrhoea and phthisis) among 930 men. Dysentery is now uncommon. The great improvement to be made at Barbadoes is decidedly a complete change of barracks. The persistent recurrence of yellow fever in these old barracks, with their imperfect arrangements, shows them to be the main cause of the appearance of the disease. The saving in the cost of a single epidemic would amply repay the outlay. As in the other islands, the black troops are now much more unhealthy than the white, and the sanitary condition of their barracks and then- food evidently require looking into. Phthisis and chronic dysentery are the chief diseases causing mortality. The average of 1859-64 gave 1,015 admissions and 20.46 deaths per 1,000 of strength. In 1865 there were 22.64 deaths per 1,000 of strength, or, excluding violent deaths, 20.49 ; of these phthisis caused 14.34, or no less than 70 per cent, of total deaths. No separate information is now available from the " Army Medical De- partment Reports." 314 PKACTICAL HYGIENE. St. Lucia. Strength of garrison = 100 men, now usually black troops. Civil popu- lation (in 1871), 36,610. St. Lucia is divided into two pai'ts : Basseterre, the lowest and most cultivated part, is very swampy ; Capisterre, hilly, with deep naiTow ravines, fvill of vegetation. The climate is similar to that of the other islands, but is more rainy and humid. Diseases of the Wliite Troops. — From 1817-36; average strength, 241; average deaths, 30 = 122.8 per 1,000 of strength. Of the 122.8 deaths, 63.1 were from fevers, 39.3 from bowel disease, and 12.5 from lung disease. Pigeon Island (a few miles from St. Lucia) was formerly so unhealthy that on one occasion 22 men out of 55 died of dysentery in one year, and of the whole 55 men not one escaped sickness. The cause is supposed to have been bad water. Now Pigeon Island is considered healthy. Although the mortality was formerly so great, St. Lucia has been very healthy for some years. In 1859, mean strength of white troops, 96 ; admissions, 113, and there was not a single death, although, if the mortality had been at the rate of the twenty years ending 1836, 12 men would have died. Better food, some improvement in barracks, and the use of rain- instead of well-water, have been the causes of this extraordinary change. Twenty two men were admitted with " continued fever," 18 with ophthal- mia, and only 2 with venereal. In 1860 there was no case of dysentery and only two of dian-hcea among 100 men in this island, where formerly there would have been not only many cases, but 4 deaths. One man died fi'om phthisis, or at the rate of 10 per 1,000. In 1861, out of 94 men, there was one death fi-om jaundice, or at the rate of 10.6 per 1,000. In 1862 there were 88 men on the island ; one man was drowned ; there was no death from disease. No case of jaundice was admitted. "In 1863 there were 55 men, and one death fi'om accident; there were 64 admissions, of which 15 were accidents. The total death rate among the white troops in the West Indian Com- mand was, in 1880, 8.68 per 1,000, of which 5.79 only were due to disease ; invalids sent home, 42.43 per 1,000, of whom 12.54 were finally discharged. British Guiana (252,000 inhabitants in 1881). No white troops are at present stationed at Demerara. This station in the West Indian Command is on the mainland, extend- ing from the equator (nearly) to 10° N., 200 to 300 miles, and inland to an uncertain distance. It is a flat alluvial soil of clay and sand, covered with vegetation. The water of Georgetown is not good ; it is drawn from a fi-esh-water lake and an artesian well ; the water from this well contains a good deal of iron. Trade- winds from N.E. an E. for nine months. In Jul}^, August, and September, S.E. and S. and laud- winds. This is the imhealthy season. Two wet seasons, January and June ; the last is the longest. Temperature of summer, 86° ; of winter, 82°. Bain, about 100 inches. Formerly there was an enormous mortahty among the troops from FOREIGN SERVICE. 315 yellow fever and scorbutic dysentery. The men used to have salt meat five times a week. The climate is most highly malarious, but this does not cause much mortahty. Yellow fever has prevailed here several times. On one occasion (1861) the troops were moved out and encamped at some distance from George- town ; they escaped (7 mild cases only), although they were on a swampy plain. In 1817-36 the average deaths were 74 per 1,000 of strength. In 1859, out of a mean strength of 143, there were 156 admissions = 1,091 per 1,000 of strength ; 2 deaths = 13.9 per 1,000 of strength. One death from apoplexy, one from drowning. The deaths from disease were only 6.9 per 1,000. "Of the 156 admissions, no less than 81 were from malarious disease, or at the rate of 519 per 1,000 of strength, or nearly one- half the total admissions. In 1860, 1861, and 1862, the admissions from malarious disease con- tinued high (673, 1,380, and 1,104 per 1,000 of strength), the mortality was very small, being only 6.6 per 1,000 in each year ; in fact, the single death in 1860 and in 1861 was in the one year from "acute hepatitis," and in the other from accident. In 1862, in spite of the immense malarious disease, there was no death. Subsequently to 1861 it appears that scattered cases of yellow fever occurred among the shipping and in the town every year ; in 1866 there was an outbreak among the white troops. In eight weeks 16 deaths oc- curred among 72 men, or 22 per cent.' Some important lessons are di'awn from the medical history of this sta- tion. It has been shown that even in a highly malarious country yellow fever may be evaded by change of ground, although the men are obliged to encamp on a swamp. Another remarkable point is the very small mor- tality attending the paroxysmal fevers. It would be very interesting to know the future history of such men, but it cannot be doubted that the lessened mortality since former years must be owing to better treat- ment. The extent of malarious disease shows how desirable it is to avoid send- ing white troops to Demerara. In French Guiana, Dr. Laure, besides malarious fevers, describes typhoid fever to have occurred for some short time after the arrival of French poUtical prisoners after the coujj d'etat of 1851. It then disap- peared. ' A full inquiry was made into this outbreak ; it was, as so frequently happens, localized, for the troops were suffering severely, while the health officer for the port (Dr. Scott) states in his evidence (Report of the Commissioners appointed to Inquire into the Outbreak of Yellow Fever at Demerara in 18(j6, p. 25) that the cases in town were "very few" at the time. The barracks were badly circumstanced in various ways, particularly in having removal of sewage on a trench system, into which the latrines opened, and which trenches were intended to be kept clean by flushing ; they were, however, in a veiy foul state, and were merely open cesspools ; and the evidence of Surgeon-Major Hutton (Report, p. 87) clearly points out that a thoroi^ghly good sys- tem of dry removal is the proper plan for this colony. Whether this and the other unsanitary conditions gave its local development to the yellow fever, was a matter of doubt in the colony ; but they are precisely the same conditions which have been so frequently seen in West Indian outbreaks - a foul soil, and, iu addition, open cess- pools exposed to the intense heat of a tropical sun, and to the influence of a moist atmosphere and a moist soil. On this occasion the troops were not removed from the barracks until too late. 316 PRACTICAL HYGIENE. Bahamas and Honduras. The black troops garrison both those places, and show a degree of mortahty nearly the same as in the other stations, the amount of phthisis being very great. In 1862, at the Bahamas, there were no less than 4 deaths from phthisis out of a strength of 439,- or at the rate of 9.1 per- 1,000 of strength ; there were also 3 deaths from pneumonia and 1 from l^leui'isy. In the years 1859-66 the average deaths from tubercular dis- eases per 1,000 men were 11.04 yearly, and from other diseases of the lungs, 5.86 ; out of 100 deaths, 60 were from diseases of the lungs. This is evidently a matter for careful inquiry. At Honduras, among the black troops, the deaths from tubercular cfisease, in 1859-66, were 4.04 per 1,007 of strength. SECTION m. BERMUDA. Usual strength of garrison, about 1,900 men. Civil population (in 1881), 13,948. Climate. — Hot, equable, and rather Umited. Temperature. — Mean of year, 74° ; hottest month (July), 83.5° ; coldest month (February), 64.5° ; amplitude of yearly fluctuation, 19°. Kelative humidity about 74 per cent. The sanitary condition was formerly very bad ; there were no sewers, and no efficient dry method of removal. Now matters are much improved, and in 1875 the health of the troops was reported excellent. Rain-water is used for drinking. Diseases of the Troops. Loss of Strength per 1,000 per annum. Loss of Service per 1,000 per annum. Years. Total Deaths. Deaths from Disease. Invaliding. Admissions. Mean Daily Sick. Days in Hospital to each Sick Man. 1817-36 1837-46 28.8 35.5 26.02 169.54 8.55 15.04 8.96 9.62 .... 168.83 5.70 8. 61 20.6 2'l.92 20.45 29.89 768 1080 764.3 716.5 637.1 696.0 39.54 35.39 32.62 40.15 .... 1861-70 (10 years) . . 1864 (highest ; yellow fever year) 1860 (lowest) 1865-74 (10 years) . . 1870-79 (10 years) . . 1880 15 18.27 18.69 21.11 This history of the West Indies may be applied to Bermuda, though, with the excei^tion of yellow fever years, it never showed the great mor- tality of the West Indies. There is no great amount of paroxysmal fevers ; in ten years (1837-46) there were only 29 admissions out of an aggregate strength of 11,224 men. In ten years (1870-79) there were only 15 ad- missions out of 18,974, or at the rate of 0.8 per 1,000. Yellow fever has prevailed seven times in this country — viz., in 1819, 1837, 1843, 1847, 1853, 1856, and 1864. FOEEIGN SEE VICE. 317 The history of the yellow fever in 1864 is given in detail by Dr. Barrow, ' The total mortality was 14 officers, 173 men, 5 women, and 4 children. The deaths to strength were, among the officers, 189, and among the men, 149 per 1,000. The officers' mortality was owing to a large number of deaths among the medical officers. The town of St. George's, in Bermuda, presents every local condition for the spread of yellow fever ; the town is quite unsewered ; badly sup- plied with water ; badly built. "Dandy fever," or break-bone (Dengue), has prevailed several times. " Continued fevers " (no doubt in part typhoid) have always prevailed more or less at Bermuda. In the ten years (1837-46.) they gave 1,004 ad- missions out of 11,-224 men, or 88 per 1,000 of strength, being much greater than at home. In ten years (1870-79) there were 884 admissions out of 18,974, or 47 per 1,000 ; in 1880 the ratio was 42.6. In 1859 there were only 11 cases of " continued fever " out of 1,074 men ; but in 1860 "continued fever" prevailed severely (209 cases in 1,052 men). It was of a mild type, and caused little mortahty. It was probably not typhoid, but its nature has not been definitely determined. It pre- vailed in September, October, and November. It is said that the drainage was defective at Hamilton. In 1866 there was decided typhoid fever, and a considerable mortality. In 1875 there were 5 admissions recorded and 1 death in 1,902 men. In 1880, 27 admissions and 6 deaths. Formerly tuberculous diseases caused a considerable mortality. In the years 1817-36, diseases of the lungs gave a mortality of no less than 8.7 per 1,000 of strength. In 1837-46, the lung diseases gave a yearly mor- tality of 8.3 per 1,000 of strength. Of late years the amount has decreased. The admissions and deaths respectively were 10.5 and 2.6 in the seven years (1859-65). In 1870 the deaths from phthisis were 1.57, and in 1871 no less than 5.19 per 1,000 of strength ; in 1875 they were 1.58. Diarrhoea and dysentery were also formerly very common, but of late' years there has been a great decrease. Diseases of the eyes are common. There has always been much intemperance, and a large number of deaths from delirium tremens. This was the case even in 1866 ; there were no less than 5 deaths out of a total of 28. Venereal diseases have averaged from 55 to 80 per 1,000 of strength. In considering the sanitary measures to be adopted at Bermuda, it would seem that drainage and ventilation are still most defective, and that means should be taken to check intemperance. If yellow fever occurs, the measures should be the same as in the West Indies. SECTION IV. NORTH AMERICAN STATIONS. Sub-Section I. — Canada.^ The usual garrison used to be from 3,000 in profound peace to 10,000 or 12,000 in disturbed times. In 1871 the troops were withdrawn from Canada and concentrated at Halifax. ' Army Medical Report, vol. v. , p. 290. ^ For an excellent account of the Canadian stations, see Sir W. Muir's Report in the Army Medical Report for 1862, p. 375. 318 PRACTICAL HYGIENE. Lower Canada. Chief Stations— 1. ^ue&ec (62,446 inhabitants). Temperature. — Mean of year, 41° ; hottest month (July), 71.3° ; coldest (January), 11°. Annual fluctuation, 60.3°. The undulations of temperature are enormous. In the winter, some- times, there is a range of 30, 40, and even more degrees in twenty-four hours, from the alternation of northerly and southerly winds. In one case the thermometer fell 70° in twelve hours. The mercury is sometimes frozen. The mean tempei'ature of the three summer months is 69° ; winter months, 12.8°. The climate is "extreme" and variable. Hain. — About 36 to 40 inches. The air is dry in the summer, and again in the depth of winter. Ban-acks. — Built on lower Silurian rocks. No ague is known, though the lower town is damp. Amount of cubic space small. Casemates in citadel very bad, damp, ill ventilated, ill lighted. 2. Montreal (140,862 inhabitants). Temperature. — Mean of year, 44.6° ; hottest month (July), 73.1° ; coldest (January), 14.5°. Annual fluctuation, 58.6°. The undulations are very gi'eat, though not so great as at Quebec. Mean of the three summer months, 70.8° ; of the three winter months, 17.2°. Rain. — 36 to 44 inches. Barracks. — Bad ; very much overcrowded. In Lower Canada are also many smaller stations. Upper Canada. Chief Stations — 1. Toronto (86,455 inhabitants). Temperature. — Mean of year, 44.3° ; hottest month (July), 66.8° ; cold- est (February), 23.1°. Difference, 43.7°. Great undulations. Rain. — 31.5 inches. The town stands on ground originally marshy. The new barracks are built on limestone rocks of Silurian age. Average cubic space only 350. Drainage bad. , Intermittent fevers among the civil population ; not very prevalent among the troops. 2. Kingston (14,093 inhabitants). Temperature. — Mean of year, 45.8°. Malarious. London, Hamilton, and several smaller stations — Fort George, Amherst- berg, etc. — were also occupied at one time. Diseases of the Civil Inhabitants. Formerly ague was prevalent in Upper Canada, especially in Kingston ; it is now much less. At Montreal ague used to be seen ; now is much less frequent. It prevails from May to October, and is worst in August. FOREIGlSr SERVICE. 319 If the summer isothermal of 65° be the northern limit of malaria, both Quebec and Montreal are within the limit ; yet the winter is too severe, and the period of hot weather too short, to cause much development of malaria. The climate is in both provinces very healthy, and has been so from the earliest records, though, when the country was first settled, there was much scurvy. T}'phoid is sometimes seen. Typhus has been often carried in emigrant ships, but has not spread, or at least has soon died out. Cholera has pre- vailed. Yellow fever dies out. ConsumjDtion is decidedly infrequent. Acute pulmonary diseases used to be considered the prevalent com- plaints, but it is doubtful whether they are much more common than else- where. Diseases of the Troops. 1,097 Tears 1817-36 (20 years). — Admissions per 1,000 of strength deaths, 16.1 (without violent deaths). Years 1837-46 (10 years). — -Yearly admissions per 1,000 of strength, 982; average daily sick per 1,000 of strength, 39.1; mortahty (violent deaths excluded), 13 ; mortahty with violent deaths, 17.42. The mortality was made up in part of — fever, 2.13 ; lung disease, 7.44; stomach and bowels disease, 1.11 ; brain disease, 1.28. Nearly two-thirds of the fevers are returned as " common continued," probably typhoid. Venereal admissions, 117 per 1,000. Erysipelas was epidemic at Quebec, Montreal, and Toronto in 1841 ; at Montreal in 1842, from bad sanitary conditions. The foUowing table shows the mean of the later years : — Loss of Strength, per 1,000. Loss of Service per 1,000. Years. By total Deaths. By Deaths from Disea.se. By In- validing. Admis- sions. Mean Daily Sick. Days in Hospital to each Sick man. 1861-70 (10 years) 1871 9.01 9.55 5.87 15.9 17.6 646.9 679.8 30.36 33.15 17.14 17.8 Influence of Age on Mortality. Years. Under 30. 20-24. 25-29. 30-34. 35-39. 40 and over. 1861-70 (10 years) . 3.47 6.01 9.80 11.13 17.66 20.23 These numbers show, what indeed is apparent in all the records, that Canada is a very healthy station. The amount of phthisis was always smaller than on home service, and regiments of the Guards proceeding from London to Canada had on two occasions a marked diminution in phthisical disease. In this respect, also, Canada contrasted formerly -vrith the West Indies, 320 PRACTICAL HYGIENE. but of late years the decline of phthisis in the AYest Indies has lessened the superiority of Canada. The comparatively small amoimt of phthisis was remarkable, as the troops were at times very much crowded in barracks. Latterly they had the home allowance of space (600 cubic feet). In the later years phthisis declined considerably with improved barrack accommodation. In the 20 years, 1817-36, the annual admissions were 6.5, and the deaths 4.22, per 1,000 of strength. In the years 1859-65 the admissions from the whole tubercular class were 8.3, and the deaths were 1.67, per 1,000 of strength.' It is curious to observe that this diminution was coincident with a similar change at home.'' The acute lung affections, pneumonia, and acute bronchitis, ap- pear formerly to have been rather more prevalent in Canada than they were in later years. The following table gives the mean and extremes for 8 years (1859-66) : — Per 1.000 of Strength. Admissions. Deaths. Pneumonia— Mean 12.24 0.8576 Highest 15.33 1.996 Lowest 7.91 0.411 Acute bronchitis— Mean 42.67 0.309 Highest 49.79 0.719 Lowest 28.48 0.092 Average of the mean of both 27.45 0.5833 If this table is compared with the similarly constructed table (at page 283), showing the prevalence of these diseases at home, it appears that both pneumonia and acute bronchitis were rather more fatal in Canada. Both together gave a mortality of .868 per 1,000 at home, and 1.166 per 1,000 in Canada. The admissions from pneumonia were also higher, but those from acute bronchitis were one-third less than at home, showing that the common catarrhal affections were less frequent in Canada. On the whole, however, the influence of the severe climate and the exposure on guard in Canada produced less effect than might have been anticipated. "Continued fevers" (probably enteric) almost yearly gave some mor- tality ; the mean being about .6 per 1,000 of strength. This was actually more than on home service, and dej^ended probably on the difficulties con- nected with drainage. A good dry system is the only plan which can be depended on in Canada. The great healthiness of Canada in part probably depends on the fact, that the extreme cold in winter lessens or pi'events decomposition of ani- mal matter and the giving off of efHuvia ; hence, in spite of bad drainage ' Still the lung complaints were higher than they ought to have been. Sir William Muir (Army Med. Eeport, vol. viii., p. 56), after detailing the measures taken by him to improve the barrack accommodation, says, "I cannot help thinking that the large number of men treated and invalided for chest disease, during the five years I hav« been on this command, bears a close relationship to this impure state of barrack air." 'In contrasting the consumptive invalidity at Gibraltar, Bermuda, and Canada, the Reporters of 1839 (Army Med. Report) remark, that the returns " afford another inter- esting proof how little the tendency to consumption is increased either by intensity of cold or sudden atmospherical vicissitudes." See also the remarks on Phthisis in India at a subsequent page. * FOEElGIf SERVICE. 321 and deficient water, there is no very great amount of fever. In the hot summer, the life is an open-air one. Even in winter the dry cold peiTaits a good deal of exercise to be taken. The amount of drunkenness and delirium tremens in Canada used to be great. In 1863 no less than 9 out of 96 deaths, or nearly one-tentk, were caused by delirium tremens. Violent deaths also are usually large, drowning giving the largest proportion The sickness and mortality of Nova Scotia and Newfoundland are al- most identical with Canada, and they are now included in the returns under the one head of "Dominion of Canada." Both stations have always been considered very healthy. There is some typhoid fever at Halifax, and at both places there was formerly much diinking, but that is now less. In British Columbia, where there is a small garrison of 100 to 150, the health is also extremelv good. SECTION V. APRICAN STATIONS. Sub-Sectiox L — St. Helena. Garrison, 200. In 1880 only 194. Civil population (in 1881), 5,059. Untd comparatively recently this small island was garrisoned by a local corps (St. Helena Regiment), which has now been disbanded. The island has always been healthy ; seated in the trade- winds, there is a tolerably constant breeze from southeast. The average mortality in the years 1859-66 was 9.75, or -without violent deaths, 7.85. In 1867 the mortality from disease was only 5.24 In 1875 almost the same, viz., 5.41. There is very httle malarious disease (about 50 to 60 admissions per 1,000 of strength), but there has frequently been a good many cases of *' continued fever," and dysentery and diarrhoea are usual diseases. For- merly there appears to have been much phthisis, but this is now much less, gi^^ing another instance of the decline of this disease, as in so many other stations. In the years 1837-46, the admissions from tubercular diseases aver- aged 21 per 1,000 per annum, and the deaths 5.45. In the years 1859-66 the admissions from tubercular diseases were 6.6 ; and the deaths 1.66 per 1,000. In 1867 there were no admissions. The health of the troops would have been even better if the causes of the continued fever and dysentery could have been discovered and removed, and if the amount of di-unken- ness had been less. The returns from St. Helena are now combined with those from the Cape of Good Hope. Sub-Section IL — West Coast of Africa.' The principal stations are Sierra Leone and Cape-Coast Castle. The station of Gambia has now been given up, and troops are no longer stationed regularly at Lagos (500 miles from Cape-Coast Castle, and occupied in 1861). In 1875 SieiTa Leone, Cape-Coast, and Accra were occupied, and Elmina for a short time, and since then the two first stations have been ' For a very good account of the topography of the Gold Coast, see Dr. R. Clarke's paper in the Transactions Epid. Society, vol. i. Vo:.. II.— ai 322 PRACTICAL HYGIENE. alone garrisoned. No white troops are employed, except during war-time, as in the Ashanti campaign of 1873. Sierra Leone. Strength of garrison, 300 to 500 black troops, with a few European officers and non-commissioned officers. Civil jDopulation (in 1872), 37,089. Hot season from May to the middle of November ; Harmattan wind in December ; soil, red sandstone and clay, veiy ferruginous. Thei-e are ex- tensive mangrove swamps to N. and S. Water very pure. The spring in the barrack square contains only 3 to 4 grains per gallon of solids. This station had formerly the reputation of the most unhealthy station of the army. Nor was this undeserved. From 1817 to 1837 (twenty years) there were yearly among the troops — Admissions 2,978 per 1,000 Deaths 483 At the same time, about 17 per cent, of the whole white population died annually. The chief diseases were malarious fevers, which caused much sickness, but no great mortahty ; and yellow fever, which caused an immense mor- tality. Dysentery, chiefly scorbutic, was also very fatal. The causes of this great mortality were simple enough. The station was looked upon as a place of punishment, and disorderly men, men sen- tenced for crimes, or whom it was wished to get rid of, were drafted to Sierra Leone. They were there very much overcrowded in barracks, which were placed in the lower part of the town. They were fed largely on salt meat ; and being for the most part men of desperate character, and without hope, they were highly intemperate, and led, in all ways, lives of the utmost disorder. They considered themselves, in fact, under sentence of death, and did their best to rapidly carry oiit the sentence. Eventually, all the white troops were removed, and the place has since been garrisoned by one of the West Indian regiments. Of late years, the total white population of Sierra Leone (civil and military) has not been more than from 100 to 200 persons. The great sickness and mortality being attributable, as in so many other eases, chiefly to local causes and individual faults, of late years Europeans have been comparatively healthy ; although from time to time fatal epi- demics of yellow fever occur. They are, however, less frequent and less fatal than formerly. The position of the barracks has been altered, and the food is much better. One measure which is supposed to have improved the health of the place, is allowing a species of grass (Bahama grass) to grow in the streets. The occupiers of the adjacent houses are obliged to keep it cut short, and in good order. During the four years, 1863-66, there died 8 white non-commissioned officers, in the whole command of the West Coast, out of an average strength of 25, or at an annual rate of 80 per 1,000 of strength. Three of 'the 8 deaths Avere from liver disease, two from delirium tremens, two fi'om fevers, and one from dysentery. In 1867 two sergeants died, out of 15 white men — one from apoplexy, one fi'om dQlirium tremens. Among the black troops serving in Sierra Leone and the Gold Coast, the returns of the ten years (1861-70) give 1,283 admissions and 22.49 deaths per 1,000. In 1871 the deaths were 15.63 per 1,000 from disease. FOREIGN SERVICE. 823 In ten years (1870-79) the admissions were 1640.5 and the deaths 25.07 per 1,000. 1873 was the year of the last Ashanti war. In 1880 the admis- sions were 1565.7 and the deaths 22.47, of which 20.86 were from disease. These numbers are for the whole West African command. Among the causes of death, tubercular diseases hold the first place, amounting to 7.05 per 1,000 of strength. In 1862 phthisis amounted to no less than 12.6 per 1,000 of strength, and constituted 43.7 per cent, of all deaths from disease. There were also 9.46 per 1,000 of strength deaths from pneumonia. In 1863 the deaths from phthisis were 9.3 per 1,000 of strength, and made up 36.3 per cent, of the total deaths. In 1867 the tubercular deaths per 1,000 of strength were 17.71 in Sierra Leone, 15.87 at the Gambia, and 12.58 at the Gold Coast and Lagos together. In 1880 the total rate for the com- mand was 11.23 per 1,000. It seems clear, indeed, that in all the stations of the West Indian corps (black troops), the amount of phthisis is great ; in fact, the state of health generally of these regiments requires looking into, as in the West Indies. In 1862 there were only five cases of intermittent, and eighteen of re- mittent fever among 317 negroes. In 1880 the number was 404 out of 623. In 1861 some of the troops from Sierra Leone and the Gambia were employed up the Gambia against the Mandingoes, and also against the chiefs of Quiat. In 1863 and 1864, and again in 1<'^73, Ashanti wars prevailed. All these wars added to the sickness and mortahty, so that these years are not fair examples of the influence of the climate. Gambia. No troops have been quartered here of late years, and it has been in contemplation to abandon the station. It is much more malarious than any of the others. The drinking water is bad ; all barrack and sewage arrangements are imperfect. Yellow fever from time to time is very destruc- tive. In 1859 two out of four European sergeants, and in 1860 three medical officers, died of yellow fever. Among the black troops in 1859-65, the admissions were 1169.8 and the deaths 29.97 per 1,000 of strength. As at Sierra Leone, phthisis and other diseases of the lungs caused a large mortality among the negroes. In 1861 phthisis gave five deaths out of a strength of 421, or at the rate of 11.6 per 1,000 strength ; and pneu- monia gave four deaths, and acute bronchitis three, or (together) at the rate of 16.24 per 1,000 of strength. Phthisis, pneumonia, and bronchitis gave nearly 60 per cent, of all deaths from disease. This was higher than in previous years ; but in 1862 phthisis gave 14.35 deaths per 1,000 of strength, and constituted 75 per cent, of the whole number of deaths. There was, however, no pneumonia or bronchitis in that year. In 1856 the tubercular class gave 9.53 deaths per 1,000. In 1863, however, there were no deaths from phthisis. Although the period of observation is short, it can hardly be doubted that here, as elsewhere in the stations occupied by the West Indian regiments, some causes influencing the lungs prejudi- cially are everywhere in action. It is probably to be found in bad ventila- tion of the barracks. Among the few white residents at the Gambia, diarrhoea, dysentery, and dyspepsia appear to be common. These, in part, arise from the bad water ; in part from dietetic errors (especially excess in quantity), and want of exercise and attention to ordinary hygienic rules. 324 PRACTICAL IIYGIEXE. Cape-Coast Castle {Gold Coast). Garrison, 300 to 400 (black troops). This station has always been considered the most healthy of the three principal places. It is not so malarious as even Sierra Leone, and much less so than the Gambia, and has been much less frequently attacked "svith yellow fever. Dysentery and dyspepsia are common diseases among the white residents. Among the black troops the prevalence of phthisis, pneumonia, and bronchitis is marked, though less so, perhaps, than at the other two stations. One peculiarity of the station was the prevalence of dracunculus. This was much less common at SieiTa Leone, and at the Gambia. It appears to have lessened considerably in later years, but there is no definite informa- tion now to be obtained from the A. M. D. Reports. Hygiene on the West Coast. There is no doubt that attention to hygienic rules will do much to les- sen the sickness and mortahty of this dreaded climate. In fact, here as elsewhere, men have been contented to lay their own misdeeds on the chmate. Malaria has, of course, to be met by the constant use of quinine diu'ing the whole period of service. The other rules are summed ujd in the following quotation from Dr. Eobeii; Clarke's paper,' and when we reflect that this extract expresses the opinion of a most competent judge on the etiect of cUmate, we must allow that, not only for the West Coast, but for the West Indies, and for India, Dr. Clarke's oj^inions on the exag- geration of the effect of the sun's rays and exposiu-e to night aii', and his statement of the necessity of exercise, are full of instruction : — " Good health may generally be enjoyed by judicious attention to a few simple rules. In the foremost rank should be put temperance, with regular and industrious habits. European residents on the Gold Coast are too often satisfied with wearing apparel suited to the climate, overlooking the fact that exercise in the open air is just as necessary to preserve health there as it is in Europe. Many of them likewise entertain an impression that the sun's rays are hurtful, whereas in nine cases of ten the mischief is done, not by the sun's rays, but by habits of personal economy. Feehng sadly the wearisome sameness of hfe on this part of the coast, recoui'se is too frequently had to stimulants, instead of resorting to inexhausting em- ployments, the only safe and effectual remedy against an evil fi-aught with such lamentable consequences. Eiu'opeans also bestow too little attention on ventilation, far more harm being done by close and imj)ure air during the night than is ever brought about by exposure to the night air. "Much of the suffering is occasioned by over-feeding." ^ ' Trans, of the Epidem. Soc, vol. i., pp. 123, 124. * Considerable interest in this part of the work was roused by the occurrence of the Ashanti war of 1873, for an admirable account of which see the Army Medical Reports, vol. XV., where Sir Anthony D. Home gives a full medical history of the operations carried on. The excellent hygienic arrangements enabled the arduous work of the ex- pedition to be accomplished with a comparatively small loss. But the few casualties in action, compared with the deaths by disease, show by contrast how much more deadly were the forces of nature than those of the enemy : 26 officers died, of whom only five were killed or died of wounds; 13 men were kiUed (white troops), while 40 died of disease ; of the West Indian troops (black) only 1 was killed, while 41 died of disease. For analysis of soil of Gold Coast, see Army Med. Reports, vol. xiv., p. 264 ; and for some account of the drinking-water, see paper by Dr. J. D. Fleming, in vols. xiv. and XV. foreig:jt service. 325 Sub- Section HI. — Cape op Good Hope. Garrison, about 3,000 men. The chief stations are Cape Town (about 45,000 inhabitants), Graham's Town, King William's Town, Port Elizabeth, Algoa Bay, and several small frontier stations. At Natal there is also a small force. The chmate is almost everywhere good ; the temperature is neither extreme nor very variable ; the movement of air is considerable. At Cape Town the mean annual temperature is 67°, with a mean annual ransfe of about 38°. Years. Total Deaths. Admissions. Mean dally Sick. Days in Hospital to each Sick Man. 1860-69 (10 years) 10.87 9.72 973 906 50.24 43.85 18.83 1870-77 (8 years) ' 17.88 The statistics of later years are complicated by the casualities of war, included killed and wounded in action and a great excess of fever. Ehm- inating these, we have the following ratios per 1,000 : — Total Admissions. 1870-77 (8 years of peace) ! 906 1878-80 (3 years of war) 900 Wounds and Injuries. 131 103 Admissions for Disease only 775 797 Continued Fever. 39 159 Paroxysmal Fever. 28 38 Admissions for Disease, excluding Fevers. 708 600 Deaths per 1,000 of Strength. Years. Total Wounds and Injuries and Killed in Action. Disease only. Continued Fever. Paroxysmal Fever. Deaths from Disease, excluding Fevers. 1870-77 (8 years) 1878-80 (3 years) 9.72 50.43 1.94 28.98 7.78 21.45 0.50 11.16 0.24 1.13 7.04 9.18 As regards the admissions, which in total number appear Httle if at all influenced by war, it is clear that the diminution which might have been expected in consequence of sanitary improvements was chiefly arrested by the great number of cases of continued fever, which occurred during the period of hostilities. In times of peace there is but little fever, and a small and decreasing mortality. Thus, in 1856-66, the death-rate was 1.25 per 1,000, in 1870-77 only 0.50,— while in 1878-80 it was no less than 11.16 ; in all these cases the deaths are almost invariably enteric. Parox^'smal fevers, arising in the station itself, are very uncommon, the worst year in the period 1870-77 being 1874, when these diseases appeared among troops ^ Including the detachment at St. Helena. 326 PRACTICAL HYGIENE. from the Mamitius, where it had undoubtedly been contracted. During the period of hostilities there -was an increase both in admissions and deaths from that cause. Although the net admissions (after eliminating wounds and injuries and fevers) are less in the later period (1878-80) than in the earher (1870-77), as shown in the preceding table, yet the death-rate is higher. This is almost entu-ely due to diseases of the digestive system, mostly dysentery and diarrhoea. These were more common formerly than they are now in ordinai-y years ; in many cases, especially in the small fi'ontier stations, they were clearly owing to bad water. Ophthalmia has prevailed rather largely, especiaDy in some years ; there is a good deal of dust in many parts of the colony, and it has been attributed to this ; the disease is probably the specific ophthalmia (gray granulations), and is propagated by contagion. "\\Tiether it had its origin in any catarrhal condition produced by the wind and dust, and then be- came contagious, is one of those moot points which cannot yet be an- swered. The Cape has always been noted for the numerous cases of muscular rheumatism. Articular rheumatism is not particularly common. There is also much cardiac disease. The prevalence of this afiection has been attrib- uted to the exposiu'e and rapid marches in hill districts during the Kaflfir wars. In 1863 there was, however, less rheumatism than usual. Taking the yeai's 1859-66 as expressing tolerably fau'ly the eflfect, per se, of the station, we find that the whole colony gave 18.3 admissions and 1.90 death per 1,000 of strenglh from diseases of the circulator}' organs. In 1869-77 the admissions were 13.5 and the deaths 1.47 ; in 1878-80 they were 20.3 and 1.25 respectively. Dr. Lawson ' has contributed a valuable paper on this subject. He finds the death-rate from diseases of the organs of circulation (mean of seven yeai's, 1859-65) at 1.91 per 1,000 of strength. This is higher than at any other foreign station, as 's^•ill be seen from the table copied by Dr. Lawson. Mortality from Diseases of the Circulatory Organs. Ratio per 1,000 Ratio per 1.0001 Ratio per 1,000 of Strength. of Strength. of Strength. Cape of Good Hope, 1.91 Bombay 0.80 Malta 0.53 New Zealand 1.18 Bengal 0.86 Gibraltar 0.70 Austraha 1.72 South China .... 1.16 ' Bei-muda 1.25 Mauritius 0.53 West Indies .... 1 02 Nova Scotia 0.84 St. Helena 0.31 Jamaica 0.85 Canada 1.19 Ceylon 1.11 Ionia 0.84 Home 0.93 Madras 1.12 , This table shows an extreme diversity, hardly to be reconciled with differences of climate or duties. In the years 1869-74 the death-rate was 1.68, and was exceeded by that of the Mauritius, 2.29, and that of Madras, 1.99. In 1875 the rate at the Cape was only 1.45, while Ceylon showed 3.87, BeiTQuda 2 63, and Madras 2.05 ; Mauritius returning no death. In the eight rears (1870-77) the rate at the Cape was 1.62 ; and in the years 1878-80 it was 1.25. Scui-vy foi-merh" prevailed much at the Cape, particularly in the Kaffir wars, and may have had something to do with the prevalence of dysentery. ' Army Medical Report, vol. v., p. 3B8. FOREIGN" SERVICE. 327 Venereal diseases have of late years been veiy common. The average admissions from "enthetic" diseases in 1859-66 were 248.5, and in 1867 they were 438.3 per 1,000 of strength in the whole colony. In Cape Town alone, wjiere facilities for promiscuous intercourse are greater, they were even more numerous. ' Much diminution has taken place in recent years. In the ten years, 1871-80, the ratio for syphihs, both primary and secon- dary, was only 102, and for gonorrhoea 80. The Cape has always been considered a kind of sanitarium for India. Its coolness and the rapid movement of the air, the brightness and clear- ness of the atmosphere, and the freedom from malaria, prc-bably cause its salubrity. It has been supposed that it might be well to send troops to the Ctfpe for two or .three years before sending them on to India. This plan has never been periectly tried ; but in the case of regiments sent on hui'riedly to India on emergency, it has been said that the men did not bear the Indian chmate well. Probably they were placed under unfavor- able conditions, and the question is still uncertain. As a convalescent place for troops who have been quartered in a mala- rious district it is excellent." SECTION VI. MAURITIUS. Grarrison, about 800 to 500 men. Civil population (in 1879), 359,988. Mauritius in the eastern has been often compared with Jamaica in the western seas. The geographical' position as respects the equator is not veiy dissimilar ; the mean annual temperature (80° Fahr.) is almost the same ; the fluctuations and undulations are more considerable, but still are not excessive ; the humidity of air is nearly the same, or perhaps a Httle less ; the rainfall (66 to 76 inches) is almost the same ; and the physical formation is really not very dissimilar. Yet, with all these points of simi- larity in climatic conditions, the diseases are very different. Malarious fever was formerly not nearly so frequent as in Jamaica, and true yellow fevei- is quite unknown ; Maui'itius, therefore, has never shown those epochs of great mortality which the West Indies have had. Hepatic diseases, on the other hand, which are so 'uncommon in the West Indies, are very common in the Mauritius. For example, in 1859 there were 47 cases of acute and chronic hepatitis in 1,254 men, while in Jamaica there was one case out of 807 men. In 1860 there were 31 admissions from acute hepatitis out of 1,886 men ; in Jamaica there was not a single case. In 1862 there were 12 cases of acute, 11 of chronic hepatitis, and 72 cases of hepatic congestion, out of 2,049 men ; in Jamaica, in the same year, there was only 1 case of acute hepatitis out of 702 men. This has al- ways been marked ; is it owing to an eiTor in diagnosis or to differences in diet ? It can scarcely be attributed to any difference in chmate. In 1868 the difference was less marked, but was stOl evident. In later years, how- ever, there has been considerable diminution : in 1872 there were only 4 cases of hepatitis, and in 1873 only 2. Since that year no detailed statis- tics have been published, but it is mentioned incidentally that there were 3 cases in 1880, out of a strength of 358. ^ Army Med. Depart. Report, vol. viii , p. 548. " See effect on th.e 59tli Regiment iu the Army Medical Report for 1859, p. 99. 328 PRACTICAL HYGIENE. In 1866-67 a very severe epidemic fever prevailed in the Mauritius, which offers many points of interest. As ah'eady noted, the Mauritius has till lately been considered to be comparatively free from malaria. All the older writers state this, and it is apparent from all the statistical retiu'ns. Deputy Inspector-General Dr. Francis Reid, in a report' in 1867, mentions that he had served ten years in the Mauritius, and had looked over the records of the troops for twenty-four j'ears. He found some records of intermittents, but he traced all these to foreign sources, viz., troops com- ing from India, China, or Ceylon, and presenting cases of relapses. For the first time, in the latter months of 1866 and the commencement of 1867, malarious fevers of undoubted local growth aj)j)eared on the western side of the island. The causes of this development were traced by Dr. Eeid, and also by Sui-geon -Major Small and Assistant Surgeon W. H. T. Power, in some very careful RejDorts.'' During some years a large amount of forest land had been cleared, and there had been much upturning of the soil ; coin- cidently the rainfall lessened, and the rivers became far less in volume. At the same time, there was a large increase of population ; a great defile- ment of the ground in the neighborhood of villages and towns, so that in various parts of the island there was a constant drainage down of filth of all kinds (vegetable and animal) into a loose soil of slight dej^th, resting on impermeable rock, which forms a great deal of the western seaboard. In 1866-67 there occurred an unusually hot season, and again a deficient rainfall. This seems to have brought into active operation the conditions which had been gradually increasing in intensity for some years. The development of the malaria was not so much on the regular marshy ground as on the loose contaminated soil ah-eady noticed. That the fever which in 1866-67 became so general was of malarious type, is proved by a large amount of evidence on the spot from both mihtary and civil practitioners, and from the fact that many soldiers re- turned to England and had at home relapses of decided paroxysmal fevers. Dr. Maclean also stated that he had seldom seen spleens so enlarged as among the invalids from this fever who arrived at Netley. But in some respects this fever presented characters difi'erent from common paroxysmal fevers. There was no very great mortality among the troops, but it was excessively fatal among the inhabitants of Poi-t Louis and many other towns and villages. It also lasted for many months, and was attended in many cases with symptoms not common in ordinary paroxysmal fevers, viz. , with yellowness of the skin and with decided re- lapses, closely resembHng in these respects the common relapsing fever. Mixed up with it also was decided t;)i3hoid fever. The question whether the great bulk of the epidemic was a jDurely paroxysmal or malarious fever, with an indej)endent subordinate outbreak of tv'phoid fever, or whether it was a composite affection like the " typho-malarial fever" of the Ameri- can war, ^ or was mixed up with the contagious "Indian jail fever "im- ported by CooUes, is not a matter very easy to decide. The officers best qualified to judge (Drs. Reid, Small, and Power) looked upon it as a ' Letter to the Director-General, February, 1867. ^ Animal Report on the District Prisons Hospitals (in 1867, Mauritius, 1868). On the Malarial Epidemic Fever of the Mauritius, Army Med. Depart. Report, vol. viii., p. 442. ^ As descrihed by Woodward, Camp Diseases of the United States Armies, by J. J. Woodward, M.D., Philadelphia, 1863, p. 77. FOEEIGN SERVICE. 329 purely malarious disease, and expressed themselves very strongly on this point. ' This much seems certain, that in various parts of the island the loose, porous, shallow soil had been gradually becoming more and more impure with vegetable matters, and in some cases with animal excreta ; that there had been a gradual diminution of the subsoil water, and that this reached its maximum in 1866, when the rains failed, and the hot season was pro- longed. There coincided, then, an unusual impurity of soil, lowered sub- soil water, consequent increased access of air, and heightened temperature. Under these conditions, a usually non-malarious soil gave rise to an epi- demic fever, which was characterized (chiefly, at any rate) by the symptoms referred to the action- of marsh miasmata, and was cm-able by quinine. The admissions for paroxysmal fevers alone were, in 1875, 585.5 per 1,000, and in 1869-75 (live years) 722.3 per 1,000 as a mean. In later years the type has been distinctly paroxysmal, the large majority of cases being re- turned as ague. The mean admissions per 1,000 for six years, 1875-80, were 970, with a maximum of 1,557 in 1879. Per 1,000 of Strength. Loss of Strength. Loss of Service. Years. Deaths (all Cau.ses). Deaths from Disease. Invaliding. Admissions. Mean Daily Sick. , Days in Hospital to each Sick Man. 1817-36 30.5 20.17 18.97 17.89 5.67 2."83 44.15 48.03 79.32 1,249.0 1,056.5 1,419.4 2,181.7 2,203.9 68.0 53.58 70.36 98.53 20.0 1861-70 (10 years) . . 1865-74 (10 years) . . 1875-80 (6 years) . . 1880 13.76 11.65 16.36 In the Mauritius, as in Jamaica, a " continued fever " is not uncom- mon ; this is now being returned in part as typhoid.^ It has occasionally been imported. There are fevers vaguely named "bilious remittent," "Bombay fever," " Coolie fever," etc. The last term denotes the communi- cable fever so common in the jaUs in the Bengal Px-esidency. It prevailed in the jails in the Mauritius in 1863 and^ 1864, among the Hindoos. The "Bombay fever" is probably typhoid. Dysentery and diarrhoea have largely prevailed, but are now becoming less frequent. In this respect Jamaica now contrasts very favorably with the Mauritius ; thus, in 1860, there were altogether 213 admissions per 1,000 of dysentery and diar- rhoea; and 6.8 deaths per 1,000 ; in Jamaica, in the same year, there was not a single admission from dysentery, and only 19 from diarrhoea, among 594 men, and no death. Cholera has prevailed five times — first in 1819 ; ' The two latter gentlemen say, op. cit. , p. 453 — "It was entirely of malarious origin, and in every form, we might say. perfectly curable by administration of qui- nine in large doses." These observers entirely deny that it had any contagious prop- erties. Dr. Reid had no doubt of the frequent occurrence of typhoid for many years. He mentioned an interesting fact, viz., that patients with true enteric fever were also aSected with the malarious epidemic fever ; this latter was, however, easily curable by quinine, but the typhoid fever, which was also present, was quite unaffected. 330 PRACTICAL HYGIENE. not afterward till 1854 ; then again in 1856, 1859, and 1861. (It appears to have been imported in all these cases.) Formerly there was a large mortality from lung diseases ; now, as in Jamaica, this entry is much less, not more than half that of former davs. The deaths from phthisis per 1,000 of strength were, in 1860, 0.521 fin 1861, 1.03 ; in 1862, 1.94 (but in this year 11 men were invalided for phthisis) ; and in 1863, 2 ; in 1875 no death was recorded. Venereal (enthetic) diseases formerly gave about 110 to 130 admissions per 1,000 of strength, but they are now greatly diminished. Ophthalmia prevails moderately ; to nothing like the same extent as at the Cape. In 1873 (the last year of detailed statistics) there were 8 admissions for diarrhoea and none for dysentery in Jamaica ; in Mauritius there were 29 for diarrhcea and 16 for dysentery and 2 deaths, out of a strength of 441. SECTION vn. CEYLON. 1 Garrison, 800 to 1,000 white troops ; and about 100 gun-lascars (black). Population, 2,758,166 (in 1881), including about 5,000 Europeans. The stations for the white troops are chiefly GaUe, Colombo, Kandy, and Trin- comalee, with a convalescent station at Newera ElHa (6,200 feet above sea- level). The black troops are more scattered, at Badulla, Pultan, Jaffna, etc. Geology. — A considerable part of the island is composed of granite, gneiss, and hornblende gTanite rocks ; these have become greatly weathered and decomposed, and form masses of a conglomex-ate called " cabook," ■which is clayey like the laterite of India, and is used for budding. The soil is derived from the debris of the granite ; is said to absorb and retain water eagerly. In some parts, as at Kandy, there is ciTstalline limestone. Climate. — This differs, of course, exceedingly at different elevations. At Colombo, sea-level, the climate is warm, equable, and limited. Mean annual temperature about 81°. Mean temperature — April, 82.70°; Januar}^ 78.19° ; amplitude of the yearly fluctuation = 4.51°. Api-il and May are the hottest months ; January and December the coldest. Amount of rain about 74 inches ; the greatest amount falls in May w^th the S.W. monsoon (about 13 to 14 inches) ; and again in October and November with the N.E. monsoon (about 10 to 12 inches) in each month. Eain, however, falls in every month, the, smallest amount being in February and March. The heaviest yearly fall ever noted was 120 inches. The relative humidity is about 80 per cent, of saturation. The S.W. monsoon blows from May to Sejotember, and the N.E. monsoon during the remainder of the year, being unsteady and rather diverted from its course (long-shore ■wind) in February and March. The mean horizontal movement during the year 1872 was 125 miles ; in 1870 it was 139 miles, or rather under 6 miles an hour. At Kandy (72 miles from Colombo, 1,676 feet above sea-level), the mean temperature is less, 3° to 5° ; the air is still absolutely humid, though relatively rather dry. At 9.30 a.m. the mean annual dew-point is 70.4°, and at 3.30 p.m. it is 71.54°. This corresponds to 8.11 and 8.42 grains in n cubit foot of air ; as the mean temperature at these times is 76.37 and 79.27, the mean annual relative humidity of the air at 9.30 a.m. ' For a full account, see Sir E. Tennant's Ceylon. FOREIGN SERVICE. 331 and 3.30 p.m. is 71 and 63 per cent, of saturation. The heat is oppressive, as Kandy Ues in a hollow, as in the bottom of a cup. At Newera EUia (48 miles from Kandy, 6,21U feet high) is a large table-land where, since 1828, some Europeans have been stationed ; the chmate is European, and at times wintry ; the thermometer has been as low as 29°, and white frosts may occur in the early morning in the coldest months. The mean annual temperature is about 59°.' In the dry season (January to May) the thermometer's daily range is excessive ; the thermometer may stand at 29° at daybreak, and at 8 a.m. reach 62° ; at mid-day it will mark 70° to 74°, and then fall to 50° at dark. In one day the range has been from 27° to 74° = 47°. The air is very dry, the difference between^ the dry and wet bulbs being sometimes 15°. As- suming the dry bulb to mark 70°, this will give a relative humidity of only 38 per cent, of saturation ; the barometer stands at about 24.25 inches. Although the diurnal range of temperature is thus so great, it is equable from day to day. Such a climate, with its bright sun and rarefied air, an almost constant breeze, and an immense evaporating force, seems to give us, at 'this period, the very beau ideal of a mountain climate. In the wet season (May or June to November) all these conditions are reversed. The mean thermometer of twenty-four hours is about 59° ; and the range is only from 56° at daybreak to 62° at mid-day ; during the height of the monsoon, thei*e are about 30 inches of rainfall, and some- times as much as 70 ; the air is often almost saturated. The mean of three years (1870-72) gives no less than 94^ inches.^ Two more striking climatic differences than between January and June can hardly be conceived, yet it is said Newera EUia is equally healthy in the wet as in the dry season ; the human frame seems to accommodate itself to these great vicissitudes without difficulty. The most unhealthy times are at the changes of the monsoons. Although there is some moist and even marshy ground near the sta- tion, ague is not common, though it is seen ; the temperature is too low in the dry season, and the fall of rain too gl'eat in the wet. Typhoid fever is seen, and may be combined with periodic fever. ^ It is said that dys- pepsia, hepatic affections, and neiwous affections are much benefited ; phthisis is so to some extent, but, it would appear, scarcely so much as European experience would have led us to expect ; rheumatism does not do well, nor, it is said, chronic dysentery ; but it would be very desirable to test this point, as well as that of the influence on phthisis, carefully. The so-called "hill diarrhoea" of India prevailed in 1865, though before this it is unknown. Dysentery has sometimes prevailed, and is caused in some cases by bad water (Massy), The son of Newera EUia is chiefly decomposed gneiss ; it is described by Dr. Massy as being as hygroscopic as a sponge ; the contents of cess- pools easily traverse it, and the removal of excreta demands great care. The neighboring Horton Hills are said to be even better than Newera EUia itself. Probably, in the whole of Hindustan, a better sanitary station does not exist. It is inferior, if it be inferior, only to the Neilgherries, and one or two of the best Himalayan stations. ' Many of these facts are from an excellent Report by Assistant-Surgeon R. A. Allan, as well as from Sir E. Tennant's book. '^ Since 1873 all meteorological information about Ceylon has been dropped out of the Army Medical Reports. ^ Massy, in Army Med. Reports, vol. viii. , p. 499. 332 PKACTICAL HYGIENE. Sickness and Mortalitif of Europeans per 1,000 of Strength. Years. Deaths. Admissions. Mean Daily Sick. Duration of Sickness. 1860-69 (10 years) 23.75 17.72 16.45 1,424.9 1,112.6 976.4 66.52 52.86 16.6 days. 1869-74 (6 years) 1875-80 (6 years) 20.00 " Influence of Age on Mortality. 1864-73 Under 20| 20 and years, under 35. 5.79 15.89 25 and | 30 and under 30. under 35. 28.81 26.50 35 and under 40. 50.25 40 and over. 173.91 Among the black troops, now reduced to about 100 altogether, in Ceylon (1860-69) the admissions averaged 1,011, and the deaths 15.17, per 1,000 of strength. In 1870 the total mortality was 9.44 (and in 1880, 11.63) per 1,000. The chief causes of admissions were paroxysmal fevers, and of deaths, cholera, dysentery, and paroxysmal fevers. " Continued fever " also figures among the returns, but was less common in the later years. The average number constantly sick was about 32, and the dura- tion of the cases 10 or 11 days. In Ceylon, therefore, the black troops were healthier than the white, contrasting in this remarkably with the West Indies. In conclusion, it may be said that much sanitary work still remains to be done in Ceylon before the state of the white troops can be considered satisfactory. * SECTION VIII. INDIA. About 50,000 Europeans are now (1880) quartered in India, and there is in addition a large native army. In this place the Europeans will be chiefly referred to, as it would require a large work to consider properly the health of the native troops. ^ The 50,000 Europeans are thus distributed : — About 31,000 are sei-ving in the Bengal Presidency, which includes Bengal proper, the Northwest Provinces, the Punjab, arid the Trans-Indus stations. About 10,000 are ' In 1876 the death-rate was only 7.43, but this was exceptional ; in 1880 it was 25, the great excess being due to dysentery in the Colombo garrison. ■^ The general principles of hygiene are of course to be applied in the case of the natives of Hindustan, and so far there is nothing unusual. In the chapter on Food, some of the articles of diet have been referred to ; the question of water and air is the same for all nations, and other hygienic rules of clothing or exercise can be easily ap- plied to them. But their health is much influenced by their customs, which are in many races peculiar. The only proper way of treating such a subject would be by a work on the hygiene of India generally, including the native army as a branch of the community. FOREIGN SERVICE. 333 serving in the Madras Presidency, which also garrisons some parts of the coast of Burmah, and sends detachments of native troops to the Straits of Malacca. About 9,000 are serving in the Bombay Presidency/ The troops consist of all arms. These men are serving in a country which includes nearly 28° of lat. and 33° of long., and in which the British possessions amount to 1,470,207 square miles, and the population to 253,000,000. Stretching from within 8"" of the equator to 13 "" beyond the line of the tropics, and embracing countries of every elevation, the climate of Hindustan presents almost every variety ; and the troops serving in it, and moving from place to place, are in turn exposed to remarkable differences of temperature, degrees of at- mospheric humidity, pressure of air, and kind and force of wind, etc. Watered by great rivers which have brought down from the high lands vast deposits in the course of ages, a considerable portion of the surface of the extensive plains is formed by alluvial deposit, which, under the heat of the sun, renders vast districts more or less malarious ; and there are cer- tain parts of the country where the development of malaria is probably as intense as in any part of the world. A population, in some places thickly clustered, in others greatly scattered, formed of many races and speaking many tongues, and with remarkably diverse customs, inhabits the country, and indirectly affects very greatly the health of the Europeans. Cantoned over this country, the soldiers are also subjected to the special influences of their barrack life, and to the peculiar habits which tropical service produces. We can divide the causes which act on the European force into four subsections — 1. The country and climate. 2. The diseases of the natives. 3. The special hygienic conditions under which the soldier is placed, 4. The service and the individual habits of the soldier. Sub-Section I. — The Country and Climate. The geological structure and the meteorological conditions are, of course, extremely various, and it is impossible to do more than glance at a few of the chief points. 1. Soil' — There is almost every variety of geological structure. In the northwest, the vast chain of the Himalayas is composed of high peaks of granite and gneiss ; while lower down is gneiss and slate, and then sand- stone and diluvial detritus. Stretching from Cape Comorin almost to Guzerat, come the great Western Ghauts, formed chiefly of granite, with volcanic rocks around ; and then, stretching from these, come the Vindhya and Satpoora Mountains, which are chiefly volcanic, and enclose the two great basins of the Taptee and Nerbudda rivers. Joining on to the Vind- hya, come the Aravalli Hills, stretching toward Delhi, and having at their highest point Mount Aboo, which is probably destined to become the great health resort of that part of India, ' For brevity, it is customary to speak of serving in Bengal, Bombay, or Madras, when speaking of the Presidency, so that these names are sometimes applied to the cities, sometimes to the presidencies ; but a little care will always distinguish which is meant. '^ See Carter's Summary of the Geology of India, in the Journal of the Bombay Asi atic Society's Transactions, 1853. 334 PRACTICAL HYGIENE. On the east side, the lower chain of the Eastern Ghauts slopes into the table-land of the Deccan ; and at the junction of the Eastern and Western Ghauts come the Neilgherry Hills, fi'om 8,000 to 9,000 feet above sea-level, and formed of granite, syenite, hornblende, and gneiss. But to enumer- ate all the Indian mountains would be impossible. Speaking in very general terms, the soil of many of the plains may be classed under four great headings. (a) Alluvial soil, brought down by the great rivers Ganges, Indus, Brahmapootra, rivers of Nerbudda, Guzerat, etc. It is supposed that about one-third of all Hindustan is composed of this alluvium, which is chiefly siliceous, with some alumina and iron. At points it is very stift' with clay — as in some parts of the Punjab, in Scinde, and in some portion of Lower Bengal. Underneath the alluvial soil lies, in many places, the so-called clayey laterite. Many of the stations in Bengal are j)laced on alluvial soil. This alluvial soil, especially when, not far from the surface, clayey lat- erite is found, is often malarious ; sometimes it is moist only a foot or two from the surface ; and, if not covered by vegetation, is extremely hot. As a rule, troops should not be located on it. Whatever be done to the spot itself — and much good may be done by efficient draining — the influ- ences of the surrounding country cannot be obviated. Europeans can never be entirely free from the influences of malaria. There is but one perfect remedy ; to lessen the force in the plains to the smallest number consistent with military conditions, and to place the rest of the men on the higher lands. Somewhat difiei'ent from the alluvial is the soil of certain districts, such as the vast Runn of Cutch, which have been the beds of inland seas, and now form immense level marshy tracks, which are extremely malarious. The Runn of Cutch contains 7,000 square miles of such country. (b) The so-called "regur," or "cotton soil," formed by disintegrated basalt and trap, stretches down from Bundelcund nearly to the south of the peninsula, and spreads over the table-land of Mysore, and is common in the Deccan. It is often, but not always, dark in color. It contains little vegetable organic matter (1.5 to 2.5 per cent.), and is chiefly made up of sand (70 to 80 per cent.), carbonate of lime (10 to 20 per cent), and a little alumina. It is very absorbent of water, and is generally thought unhealthy. It is not so malarious as the alluvium, but attacks of cholera have been supposed to be particularly frequent over this soil. (c) Red soil from disintegration of granite. This is sometimes loamy, at other times clayey, especially where felspar is abundant. The clay is often very stifi". (d) Calcareous and other soils scattered over the surface, or lying be- neath the alluvium or cotton soil. There are, in many parts of India, large masses of calcareous (carbonate of lime) conglomerate, which is called kunkur. It is much used in Bengal for pavements, footpaths, and roads generally. In Behar, and some other places, the soil contains large quantities of nitre, and many of the sand plains are largely impregnated with salts. 2. Temperature. — There is an immense variety of temperature. Toward the south, and on the sea-coast, the climate is often equable and uniform. The amphtudes of the annual and diurnal fluctuations are small, and in some places, especially those which lie somewhat out of the force of the southwest monsoon, the climate is perhaps the most equable in the world. At some stations on the southern coast, the temperature of the sun'g FOEEIGN SEEVICE. 335 zenitli is lower than at the declination, in consequence of the occurrence of clouds and rain, brought up by the southwest monsoon. In the interior, on the plateaux of low elevation, the temperature is greater, and the yearly and diui-nal fluctuations are more mai'ked. On the hill stations (6,000 to 8,000 feet above sea-level), the mean temperature is much less ; the fluctuations are sometimes great, sometimes inconsiderable. The influence of winds is very great on the temperature ; the sea winds lowering it, hot land winds raising it greatly. The temperature in the sun's rays ranges as high as 166° or 170°, but the mean sun rays' temperature is, with great differences in different places, between 130° and 160° at the hottest time of the year. The air temperature of a few of the principal stations is subjoined, merely to give an idea' of the amount of heat in different parts of the coun- try. ^ Those of the hill stations are given under the proper headings. Mean Temperature and Height, above Seor-level, of some of the larger Stations. , ^ J^ „ <0 Months. — > a 8J §1 4.^ I si § ^• 02 Mi . o o >> o > 1 o ■§ 00 ■s 1 of 5 03 i> aJi X3 5- |i ■SB ii S o ■3-2 o o o o o o o o Mean of year 82 70 73 54 74 52 82 76 76 69 80 74 78 72 74 January 72 February 75 60 55 78 73 76 75 75 March 83 88 68 77 65 75 80 84 79 79 80 ■ 83 79 83 78 April 81 May 89 86 88 87 82 86 85 78 June 87 85 89 87 91 91 88 85 77 77 83 81 81 77 75 July 73 August 85 86 88 85 75 81 76 72 September 85 83 84 84 76 80 77 74 October 84 76 73 82 75 82 79 74 November 78 61 64 79 73 79 76 72 December 73 55 56 76 71 76 73 70 Amplitude of yearly fluctuation 1 (difference between hottest V 19 35 39 12 13 12 13 11 The increase and the amplitude of the yearly fluctuation is thus seen as we pass to the north, and ascend above sea-level. In several places there are great undulations of temperature from hot land winds, or from sea or shore breezes, or from mountain currents, which give to the place local peculiarities of temperature. To get the same mean annual temperatui-e as in England, it would be necessary that 9,500 feet be ascended in places south of lat. 20° ; between ' These are taken from Mr. Glaisher's very excellent report in the Indian Sanitary Commission, which must be consulted for fuller details. Very full meteorological returns are now being given in the Reports of the Sanitary Commissioners for the three presidencies, and these will ultimately supersede Mr. Glaisher's tables. 336 PEACTICAL HYGIENE. lat. 20° and 26°, 9,000 feet ; between lat. 26° and 30°, 8,700 feet ; and north of lat. 80°, 8,500 feet. The mean monthly temperatures ■would, however, at such elevations, differ somewhat from those of England. Speaking generally, an elevation of 5,000 to 6,000 feet will give over the whole of India a mean annual tem- perature about 10° higher than that of England, and with a rather smaller range. j\Ii-. Glaisher has calculated that in the cold months the decrease of temperatui'e is 1.05° for each 300 feet of ascent, but increases from March to August to 4.5°, and then gradually declines. These results are not ac- cordant with the results of balloon ascents in this climate. Humidity, — The humidity of different parts of India varies extremely ; there ai'e chmates of extreme humidity — either fiat, hot plains, like Lower Scinde, where, without rain, the hot air is frequent!}^ almost saturated, and may contain 10 or 11 grains of vapor in a cubic foot ; or mountain ranges like Dodabetta, in Madras, 8,640 feet above sea-level, where during the rainy season the aii' is also almost saturated ; a copious rain, at certain times of the year, may make the air excessively moist, as on the Malabar coast, the coast of Tenasserim, or on the Khasyah Hills, where the south- west monsoon parts with its vapors in enormous c^uantities. On the other hand, on the elevated table-land of the interior, and on the hot i^lains of Northwest India, during the dry season, or in the places exposed to the land winds at any part, the air is excessively dry. In the Deccan the annual average of the relative humidity is only 55 per cent, of saturation (S^'kes). IVIr. Glaisher has given the humidity of many places. A few stations are here given : — Mean Humidity per cent. . i •6 so a c 5 g 1 3 1 g f g % c "1 a i ^ fa n n s P4 n 02 04 M n Mean maximum 81 79 85 94 84 73 76 84 79 80 84 " minimum 59 61 67 44 54 41 40 40 42 48 43 Yearly mean 68 73 73 69 67 55 56 54 53 62 64 The mean relative humidity at Greenwich is 82, varying from 89 in December and January to 76 in July. Calcutta, therefore, with a mean yearly humidity of 68 per cent, of satm-ation, is, as far as relative humidity {i.e., evaporating power) goes, less moist than England, and the evapo- rating power is also increased by the higher temperature. Rain. — The amount of rain and the period of fall varj^ exceedingly in the different places. It is chiefly regulated by the monsoons. When the southwest monsoon, loaded with vapor, first strikes on high land, as on the Westei'n Ghauts, on the Malabar coast, or on the mountains of Tenasserim, and especially on the mountains of the Khasyah Hills, at some points of which it meets with a still colder air, a deluge of rain falls ; as, for example, at Cannanore (Malabar), 121 inches ; Mahableshwur, 253 inches ; Moulmein (Tenasserim), 180 inches ; CherraiDoonjee (Khasyah Hills), 600 inches. On the other hand, even in places near the sea, if there is no high land, and the temperature is high, scarcely any rain falls ; rOEEIGN SEKVICE. 337 as in Aden, on the soutli coast of Arabia, or at Kota, in Scinde, wliere the amount is only 1.8 annually, or Kurrachee, where the yearly average is only 4.6 inches. Or in inland districts, the southwest monsoon, having lost most of its water as it passed over the hills, may be comparatively dry, as at Nusserabad, where only 15.8 inches fall per annum, or Peshawur, where there are 13. 7 inches annually. The yearly amount of rain in some of the principal stations is — Average. Calcutta 56.8 Madras 50 Bombay 72.7 Bengal Presidency — Dinapore 31.1 Berhampore 49.8 Benares 37.4 Ghazeepore 41.4 Azimghur. 40 Agra 27.9 Delhi 25.1 Meerut 18 Average Punjab 56.6 Madras Presidency — BeUary • 21.7 Bangalore 35 Trinchinopoly 30.6 Secunderabad 34.6 Bombay Presidency — Belgaum 51.5 Poonah 27.6 Neemuch 34.1 Kamptee 21.8 Winds. — The general winds of India are the northeast monsoon, which is, in fact, the great northeast trade-wind, and the southwest monsoon, a wind caused by the aspiration of the hot earth of the continent of Asia, when the sun is at its northern declination. During part of the year (May to August) the southwest monsoon forces back the trade-wind or throws it up, for at great altitudes the northeast monsoon blows through the whole year, and the southwest monsoon is below it. But, in addition, there are an immense number of local winds, which are caused by the effect of hills on the monsoons, or are cold currents from hills, or sea breezes, or shore winds caused by the contact of sea breezes and other winds, or by the first feeble action of the southwest monsoon before it has completely driven back the northeast trade. The southwest monsoon is in most of its course loaded with vajDor ; the northeast is, on the contrary, a colder and drier wind, except when at certain times of the year, in pass- ing over the Indian Ocean, it takes up some waier, and reaches the Coro- mandel coast and Ceylon as a moist and rain-carrying wind. The hot land-winds are caused by both the southwest monsoon, after it has parted with its moisture and got warmed by the hot central plains, and the northeast monsoon ; the temperature is very great, and the rela- tive humidity very small, the difference between the dry and the wet bulb being sometimes 15° to 25° Fahr. Fressure of the Air. — On this point little need be said. The barome- ter is very steady at most sea-coast stations, with regular diumal oscilla- tions, chiefly caused by alteration in humidity. An elevation of 5,000 feet lowers the barometer to nearly 26 inches. Electricity. — On this point few, if any, experiments have been made ; the air is extremely charged with electricity, especially in the dry sea- son, and the dust-storms are attended with marked disturbance of the electrometer. ' ' See Baddeley's Whirlwinds and Dust Storms of India (1860) for a very good ac- count of these singular storms. Vol. n.~22 338 PKACTICAL HYGIENE. Effects of Climate. — The estimation of the effects of such various climates is a task of great difficulty. Long-coutinuecl high temperature, alternations of great atmospheric dryness and moisture, rapidly moving and perhajDs dry and hot air, are common conditions at many stations ; at others, great heat during part of the year is followed by weather so cold that even in England it would be thought keen. When to these influ- ences the development of malaria is added, enough has been said to show that, a priori, we can feel certain that the natives of temperate climates wiU not support such a climate without influence on health, and the selec- tion of healthy spots for troops is a matter of the greatest moment as affects both health and comfort. This much being said, it must at the same time be asserted that, malaria excepted, the influences of climate are not the chief causes of sickness. The location of troops should be governed by two or three condi- tions — 1. Military necessities ; 2. Convenience ; 3. Conditions of health. The second of these conditions is, however, a mere question of administra- tion ; every place can be made convenient in these days of railway and easy locomotion. Military necessity and health are the only real consid- erations which should guide our choice. The \dtal military points must be held with the necessary forces, and then the whole of the remaining troops can be located on the most healthy spots. These spots cannot be in the plains. Let any one look at a geological map of India, and see the vast tract of alluvial soil which stretches from the loose soil of Calcutta, formed by the deposit of a tidal estuary, up past Cawnpore, Delhi, to the vast plains of the Punjab, Scinde, and Beloochis- tan. The whole of that space is more or less malarious, and will continue to be so until, in the course of centuries, it is brought into complete tillage, drained, and cultivated. Moreover, heat alone without malaria tells upon the European frame, lessens the amount of respiration and circula- tion, and lowers digestive power. In looking for healthy spots, where temperature is less tropical, and malarious exhalations less abundant, there are only two classes of localities which can be chosen — sea-side places and highlands. Sea-side Places. — The advantages of a locahty of this kind are the reduction in temperature caused by the expanse of water, the absence of excessive dryness of the air, and the frequent occurrence of breezes from the sea. All these advantages may be counteracted by the other features of the place ; by a damp alluvial soil, bad water, etc. It does not appear that many eligible places have yet been found, and as a substitute in Bengal, the Europeans from Calcutta sometimes live on board a steamer anchored oft' the Sandheads, thus literally carrying out a suggestion of Lind in the West Indies a century ago. In the Bay of Bengal, Waltair, in the northern division of Madras, is one of the best.' Cape Calimere (28 miles south of Nagapatam) also ap- pears to have many advantages (Macpherson). On the opposite coast, Cape Negrais, on the Burmese coast, was pointed out as long ago as 1825, by Sii* Ranald Martin, as a good marine sanitarium, and Amherst in Tenas- serim, and some of the islands down the coast toward Mergui, ai-e beauti- ful spots for such a purpose, being, howevei-, unfortunately, at a great distance fi'om the large mihtary stations, and not being well suppHed with food. On the Bombay side, at Sedashagur or Beitkul Bay, between Mangalore ' Evidence of Dr. Maclean in India Report, p. 139. FOREIGN SERVICE. 339 and Goa, a spur of tlie Western Ghauts projects into the sea for upward of a mile, and forms an admirable sea-coast sanitarium (Macpherson). All these sea-coast stations seem adapted for organic visceral affections and dysentery, but they are not so well calculated for permanent stations for healthy men. Probably they are rather sanitaria than stations. Highlands. — The location of troops on the hills or on elevated table- lands has long been considered by the best army medical officers as the most important sanitary measure which can be adopted. Not only does such a location improve greatly the vigor of the men, who on the hill stations preserve the healthy, ruddy hue of the Eurojaean, but it prevents many diseases. If properly selected, the vast class of malarious diseases disappears ; hver diseases are less common, and bowel complaints, in some stations at any rate, are neither so frequent nor so violent. Digestion and blood nutrition are greatly improved. Moreover, a proper degree of ex- ercise can be taken, and the best personal hygienic rules easily observed. Indian surgeons appear, however, to think the hill stations not adapted for cardiac and respiratory complaints ; it is possible that this objection is theoretical. The latest European experience is to the effect that phthisis is singularly benefited by even moderate, still more perhaps by great ele- vation ; that ansemia and faulty blood nutrition are cured by high positions with great rapidity, and that if the elevation be not too great (perhaps not over 3,000 feet) even chronic heart diseases are improved. In some of the hill stations of India bowel complaints were formerly so frequent as to give rise to the term "hill diarrhoea." The elevation was credited with an ef- fect which it never produced, for, not to speak of other parts of the world, there are stations in India itself (Darjeeling, for examj^le) as high as any other, where the so-called hill diarrhoea was unknown. At Newera Ellia, in Ceylon, too, if the simple condition of mountain elevation could have produced diarrhoea, it would have been present. The cause of the hill diarrhoea was certainly, in many stations, unwholesome drinking-water ; whether or not this was the case in all is uncertain. Some of the hill stations are said not to be adapted for rheumatic cases ; in other instances (as at Subathoo) rheumatism is much benefited. From reading the reports from these stations, it is more probable that damp barracks, and not the station, have been in some cases the cause of the rheumatism. But it must be noticed that the evidence given before the Indian Sani- tary Commission shows, on all or almost all hill stations, a most lamentable want of the commonest sanitary appliances. At great expense men are sent tip to the hills, where eveiything is, or was, left undone which could make that expense profitable. It appeared to be thought sufficient to as- cend 6,000 feet to abandon all the most obvious sanitary rules, without which no place can be healthy. Admitting, as a point now amply proved, that stations of elevation are the proper localities for all troops not detained in the plains by imperative mihtary reasons, the following questions are still not completely an- swered : — ■ 1. What amount of elevation is the best ? We have seen that to reduce the temperature to the EngHsh mean, 5,000 to 6,000 feet must on an aver- age be ascended. But then such an elevation brings with it certain incon- veniences, viz., in some stations much rain and even fog at certain times of the year, and cold winds. However unpleasant this may be, it yet seems clear, from the experience of Newera Ellia, in Ceylon, that damp and cold are not hurtful. But it must also be said that, with a proper selection, dry localities can be found at this elevation. 340 PRACTICAL HYGIENE. From 3,000 to 4,000 feet have been recommencled, especially to avoid the conditious just mentioned. Whether places of this height are equal in salubrity to the colder and liigher points is uncertain. Even at 6,000 feet there may be marsh land, though it is not very mala- rious. Malarious fever has been known during the rains at Kussowlie (6,400 feet), and Subathoo (4,000), and other Himalayan stations. Malaria may, however, drift up valleys to a great height,' but, apart from this, it seems likely that 5,000 feet, and probably 4,000, will perfectly secure fi'om malaria. Probably, indeed, a less height will be found effectual At no point do hot land-winds occiu", or at any rate endure, at above 4,000 feet. On the whole, it would appear probable that the best locahties are above 5,000 feet, but below 7,000. 2. What stations are the best — the tojjs of solitary hills, si:)urs of high mountains, or elevated table-lands ? Ranald Martin has called especial attention to the solitary hills, rising as they do sometimes from an ahnost level plain to 2,000 and 3,000 feet. Such mountain islands seem especially adapted for troops if there is suffi- cient space at the top. They are free from ravines conducting cold air from higher land, and are often less rainy than the spurs of loftier hills. The spurs of the Himalayas, however, present many eligible spots, and so do some table-lands. And perhaps, on the whole, if the elevation is sufficient, it is not a matter of much importance which of these formations is chosen ; other circumstances, viz., purity of water, space, ease of access, and supplies, etc., will generally decide. In choosing hill stations, the pomts discussed in the chapter on Soils should be carefully considered, and it is alwa^'s desirable to have a trial for a year or two before the station is permanently fixed. In all the presidencies of India elevated spots where troops can be can- toned exist in abundance.^ The follo-oing table, coj^ied from Dr. ^Macj^her- son's work, gives some of the principal hill stations. Fresh stations are, however, being constantly discovered, and it seems now certain that there is scarcely any important strategical point without an elevated site near it. Near Nynee Tal, in Kumaon, are Almorah (5,500 feet) apd Hawalbagh (4,000 feet), both well spoken of. Kunawai- (5,000 or 6,000 feet), in the val- ley of the Sutlej, has a delicious climate ; and Chini (about 100 miles from Simla) is a most desirable spot. Passing down from the northwest toward Calcutta, Dr. M'Clellan found elevated land within 100 miles of Allahabad ; and in the south there are the Travancore Mountains, with numerous good sites. If, then, the mass of the troops are cantoned on elevated places, the dis- advantages of climate are almost removed. The Indian Sanitary Commis- sioners recommended that one-third of the force shaU be in the hills, and ' It has drifted up even to the summits of the Neilgherries, 7,000 or 8,000 feet. — In- dian Sanitary Report, Mr. Elliott's Evidence, vol. i , p. 250. - See the evidence in the Indian Sanitary Report (vol. i.) of Sir R. Martin, Mr. El- liott, Dr. Maclean, Dr. Alexander Grant, Mr. Montgomery Martin, and others. Also most instructive reports by Mr. Macpherson, Indian Report, vol. ii., p. 622; and by Dr. Alexander Grant, Indian Annals. On the location of troops reference may also be made to the late Surgeon-General Dr. Beatson's very decided opinion on the necessity of placing on the hiUs all the men who can be spared from the military posts in the plains. No more valuable opinion could be given on such a point than that of an offi- cer who had the largest possible experience, and the best opportunities of forming a correct judgment. (See his Report in the Army Med. Report, vol. viii., p. 847.) Sir William Muir also urged this point, and the result is that gradually more and more troops are being located on the hills. rOKEIGN SERVICE. 341 © . t^ o o m O O 1— ( Jt^ c^ O ^ to iXi lO t- T— t J3 :cD CO t^ M O CM CO lO lO -^ O -^ • -«* O ^^ fM lO >0 • lO «0 CO in t- 05 (M CO 1— I CM lO CO "<* CO to CO to CO CM CO lO IQ CO CO CO • lO CO CO i-H I CO lO CO t^ CO O -* (M c^ »0 CO CO t>- CO CO t^ CO CO (M -<* O O CO CO t— i:^ -« CO 1^ o CO CO CO r^ ^oooocooo>cot--coinioo COI>>COCOt-COCOt~>-«OCOi^t^ CO o CO J:^ cOiO •QOOt^tMOicOiOOO cot- .coi^cot^t— cocoj>.t~ QO CO CO CO ^COi^COt-OOlOCOCOCO ' CO CO r— I ; CO t- i>. ;t^05C5i— ii— icooooo . X>- to CO 00 CO CO CO CO ; ^ • I— I lO CO : i:^ t- QO • cococot—cocococococo • I— I O CO . 1— OO CO 00 CO t>. lO lO lO O 1— I t- OO O 1— • CO CO CO CO CO CO OD O O CO 00 t^ • CO o 1— < c-1 CO CO - ICi CO CO CO »0 iH) CO ■^ i-H CO CO t^ o ^ -* C5 cs CO CO o CO 1 — 1 as CO 1— CO -^1 1^ cs CO CO CO o ■^ ^ no Oi CO CO CO CO i^ 05 ^ CO CO CO 1—1 t— 1 Ir- O t^ CO t^t^ CM CO t- n t- t^ t^ P M< 00 l>i Jt^ t~ t- fM b- Ci Jt— t^ t^ lO CO 1—1 CO t- CO O O lO TJi -^ CO ; (M CM p: rt o O o Darjt Lane B « 2 cs 2 a 2 2^ cS >5 S -i o fcc.y o M cS ri O '^ 'CJ a? c3 e c3 iS d PI -ti ?; d 5 g s^ ? -d Pi -« c3 d W;z;P02OWp:op4grts to do so. They did not succeed, and so marked and so general was the scor- butic taint in their army, that its combinations with enteric fever and ma- laria have been looked upon as new diseases. 372 PRACTICAL HYGIENE. If scurvy could be prevented, every other war disease oup;lit to be comparatively trifling. Inflammations from exjDosure, exhaustion from fatigue, and gastro-intestinal affections from improper food and atmos- pheiic vicissitudes, would stiU occur ; but the ravages of typhus, enteric fever, malaria, and dyse^itery ought to be trifling, and easily jDrevented. To prevent sciu'vy, then, is one of the most imj)ortant measures. If scurvy be absent, typhus fever is readily treated ; isolation and the fi-eest ventilation are certain to stoj) it. The only great danger would be in a besieged and crowded fortress. In such a place it may be beyond control, but early recognition and prompt isolation, as far as it can be done, and as free ventilation as possible, may perhaps stop it. It is in such cases that we should freely use the nitrous acid fumes and other dis- infectant vaj^ors. Enteric (typhoid) fever and contagious dysentery, in the same way, ought with certainty to be pi-evented in a camp. Recent experience, how- ever, in Affghanistan, South Africa, and Egypt has shown what ravages enteric fever can make, and how rapidly it is generated and spread among troops in campaign. This is certainly due to the neglect of proper hy- gienic measures. The first case even should make us take urgent meas- ures for the cleansing of latrines, or, better still, the closing of all the old and the opening of fresh ones. But the best plan of all is to shift the encamping ground, and we should remember the old Roman maxim, based doubtless on observation of typhoid fevers, that this must be done more often in the autumn. The exanthemata, measles, and scarlet fever sometimes spread largely through an army ; the only plan is to separate all cases, and send them one day's march on the flank of the army, if it can be done, not in the direction of the line of suj^plies. Plague probably, demands the same measures as typhus. The measures for cholera have been already sufficiently noted. The diseases of exposure can hardly be avoided, but may be lessened by warm clothes and waterpx'oof outer coverings. Flannel should be used next the skin all over the trunk and extremities, and is indispensable. One of the most important means to enable troops to stand inclemencies of weather, and indeed all fatigues, is hot food. Coffee and tea are the best, and hot spirits and water, though useful as an occasional measure, are much inferior, if indeed they do any good at all apart from the warmth. But the supply of hot food in war should be carefully attended to, especially in the case of breakfast, after which men will undergo without harm great exposure and fatigue. It is unnecessary to enter at greater length into the measures to pre- vent the diseases of war, for the proper plans have been all enumerated previously. We may conclude only that much can be done to prevent disease, but we must also remember that the course of campaigns some- times is too violent and overpowering for our efforts, and that wars, like revolutions, will never be made with rose-water. Recapitulation of the Duties of a Sanitary Officer during War. To go forward with the officers of the Quartermaster-General's depart- ment, to choose the camping ground ; arrange for surface drainage ; if necessarily in a malarious place, make use of all obstacles, as hills, trees, etc., to throw off the malaria from the tents ; place the tents with the openings from the malarious quarter. If possible, never take low hiUs WAV.. 373 (100 to 250 feet) above marshy j)lains. Arrange for the water supply, and for the seiTice of the men, animals, and Avashing. As soon as possilDle fix the sites for the latrines ; have them dug out, and make di-y paths to them. As soon as the tents are pitched visit the whole camp, and see that the external ventilation is not blocked in any "way, and that the tents are as far off each other as can be permitted. Assign their work to the scaven- gers, and mark out the places of deposit for refiise. It is of the greatest importance that all refuse should be immediately and completely de- stroyed by fire. The destruction of the stools of enteric, dysenteric, and choleraic patients by the same means would probably prove a most impor- tant jprecaution. The daily insiDection should include all these points, as well as the inspection of the food and cooking and of the slaughter-houses. If the camp be a large one, a certain portion should be selected ever)' day for the careful inspection of the individual tents, but it should be made in no certain order, that the men may not prepare specially for the inspection. A set of rules should be drawn up for the men, pointing out the neces- sity of ventilation, cleanhness of their persons, tents, and ground around them, and ordering the measures which are to be adopted. This will have to be promulgated by the general in command. In the daily work, a certain order and routine should be followed, so that nothing shall be overlooked. The sanitary officer of a large camp can never perform his duties with- out the most uni'emitting support from the medical officers attached to regiments, who are the sanitary officers of their respective coi-ps. Not only must they inspect theii* own regimental camps, but by an immediate report to the sanitary olficer of any disease which can possibly be traced to some camp impurity, they should render it possible for the commencing evil, of whatever kind, to be detected and checked. As early as possible every morning the number of men reported sick from each regiment should be made knoT\-n, and a calculation made of sick to strength, and then, if any regiment showed any excess of sick, the san- itary state of its cam]D should be specially and thoroughly investigated. Hospitals in War.^ "With an ai'my in the field, hospitals are of several kinds. 1. The principal General Hospital at the base of operations. 2. The intermediate Hospitals, di\-ided into — a. The Field Hospitals stationed at the base or on the line of com- munication. b. The Field Hospitals proper, which move with the corps, and include the dressing stations and regimental stations. The old regimental hospital is now definitely aboHshed, but medical and surgical assistance is j^rovided by a medical officer with one or two attendants, accompanied by bearers, with stretchers when required, as in ' Sir James M'Grigor, in tlie Peninsula, established divisional hospitals in front, and convalescent hospitals in the rear, where the men were received eji route to the d:pot. Although he does not describe his system fully in lais paper in the Medico- Chirurgical Transactions (vol. vi.), it is evident from his Autobiography that his con- stant practice was to send off the sick as soon as possible. This is shown by his narra- tive of the retreat from Burgos, when he saved Lord Wellington from the mortification of abandoning his sick and wounded to the enemy. Professor Longmore, in his most instructive work on Transport, has detailed at length the means of transport of the sick and wounded, and other important matters of the kind. oii niACTICAL IIYGIEXE. action in the field. The sick are treated in the field hospitals first, and then passed on to the intermediate hospitals in rear, which are again evac- uated, as occasion requires, bj transfer of patients to the principal general hospital at the base. This last will be in a convenient station on the frontier, or, in case of an insular nation Hke ourselves, on some sea-coast easily accessible. It is fi'om it that men will ultimately be invalided home if unfit for further service. For each army coi-ps (of nominally 36,000 men) 25 field hospitals are appointed — 12 to move with the coi-ps, and 13 to be stationed at the base and along the lines of commnnication ' — each is equipped for 200 sick, and may be divided into half hospitals for 100 each, if necessary. Slight cases would be treated in the field hospitals, but all cases likely to take any time should be sent to the rear of operations as soon as possible. Cases of fever (typhus and enteric) ought to be removed as soon as possi- ble far from the field force. It is of great importance that they should not be put near surgical cases, which ought to be kept sepai-ate, or mixed only with non-communicable diseases. This (the separation of fever fi-om surgical cases) was a Peninsular nile of Sir James M'Grigor, and should never be forgotten. Ophthalmic cases ought also to be isolated. The hospitals in rear may be at some distance, but connected either with a railway or by water carriage. It is of gi-eat importance to keep continually sending patients from the division and general hospitals wdth the army to the hospitals in rear. It is not only to keep the hospitals in front empty for emergencies, and to facilitate all movements of the army, but it has a great effect on the aiTay itself. A great hospital full of sick is a disheartening spectacle, and often damps the spirits of the bravest men. The whole army is higher in hope and spiirits when the sick are removed, as was shown remarkably by the Austrian experience of 1859. The sick themselves are greatly benefited by the removal ; the change of scene, of air, of ideas, has itself a man-ellous effect, and this is another great reason for constantly evacuating the sick from the hospitals in front. The men who are rejDorted for hospital in war must be dirided into several classes — 1. Slightly wounded should be treated in the field or intermediate hospitals, and then returned to duty. 2. Severely wounded at first in the field hospitals, then sent to the inter- mediate hospital, and then to the rear, as convalescence is alwaj's long. 3. SHght colds, diarrhcea, etc., treated in the field hospitals. 4. Severer colds, bronchitis, pleurisy, pneumonia, dysenter}^, etc., should be sent at once to the intermediate hospital, and then to the rear as soon as they can move with safety. 5. Typhus iever at once to the hosjDitals in rear, if possible without en- tering the field hospitals. 6. Enteric cases, also, should be sent to the rear, and, in fact, all severe cases. The field hospitals should be always almost empty, and ready for emergencies. These hospitals in rear may be even two or three days' journey off, if conveyance be by water, or one or two days if by rail. Sick and wounded men bear movement wonderfully well, with proper appliances, and are often indeed benefited.^ ' For full details of the new hospital organization in the field, see Professor Long- more's work, Gunshot Injuries (1877), sec. ix., chap. 1. - On this and other points of the like kind, see Keport on Hygiene, in the Army Medical Report for 1862, pp. 349, 350. WAE. 375 The proper position for the hospitals at the base of operations must be fixed by the commander of the forces at the commencement of the cam- paign, as he alone will know what point will be the base of supphes, and it is of importance to have these great hospitals near the large stores which are collected for the campaign. It seems now quite clear that these hospitals should not be the ordinary buildings of the country adapted as hospitals. Such a measure seldom suc- ceeds, and the mere adaptation is expensive, though pi'obably always im- perfect. ' Churches should never be taken, as they are not only cold, but often damp, and there are often exhalations from vaults. The French, Austrian, and American experience is in favor of having the hospitals in rear made of tents or wooden huts. The huts are perhaps the best, especially if the winter be cold. They were very largely used by the Federal Americans, who gave up entirely converting old buildings into hospitals. The best huts which were used in the Eussian war of 1854-56 were those erected at Renkioi from Mr. Brunei's design ; each held fifty men in four rows. This plan, however, is not so good a one as having only two rows of beds. Hammond ^ states that in the American war the best size has been found to be a ward for fifty men with two rows of beds ; length of ward, 175 feet ; width, 25 ; height, 14 feet ; superficial area per man, 87 feet ; cubic space per man, 1,200 feet. Ventilation was by the ridge, an opening 10 inches wide, running the whole length, and by openings be- low, which could be more or less closed by sliding doors. Some of the American hospitals held from 2,000 to 2,800 beds.^ It is probable, however, that smaller wards (for 25 men) would be better. An hospital constructed of such huts can be of any size, but there must be several kitchens and lau^jdries if it be very large. If space permit, how- ever, it seems desirable to have rather a collection of smaller hospitals of 500 beds each, separated by half a mile of distance, than one large hospital. The arrangement of the huts must be made according to the pi-inciples already laid down. Dr. Hammond writes thus of these hospitals : — " It will, perhaps, not be out of place again to insist on the great advan- tages of these temporary field hospitals over those located in permanent buildings in. towns. Nothing is better for the sick and wounded, winter and summer, than a tent or a ridge-ventilated hut. The experience gained during the present war establishes this point beyond the possibHity of a doubt. Cases of erysipelas or of hospital gangrene occurring in the old buildings, which were at one time unavoidably used as hospitals, but which are now almost displaced for the ridge-ventUated pavilions, immediately commenced to get well as soon as removed to the tents. But in one in- stance that has come to my knowledge has hospital gangrene originated in a wooden pavilion hospital, and in no instance, as far as I am aware, in a tent. Hospital gangi-ene has been exceedingly rare in all our hospitals, but two or three hundred cases occurring among the many wounded, amount- ing to over 100,000 of the loyal and rebel tfoops, which have been treated in them. Again, wounds heal more rapidly in them, for the reason that the ' Donald Monro says that, in 1769, the houses in Germany taken for the sick were improved by taking away the stoves and putting in open fire-places. In the Peninsula, the Duke of Wellington appeared to have a dread of fever attacking the army. Liis- combe tells us that the Duke asked the principal medical officer every day as to the appearance of fever. He also improved the hospitals by ordering open fire-places.' — Luscombe, p. 6. ^ On Hygiene, p. 355. ° See Report on Hygiene, in the Army Medical Eeport for 1862, p. 345 et seq., for a fuller description. 376 PRACTICAL HYGIENE. full benefit of the fresh air and the light are obtained. Even in fractui-es the beneficial effects are to be remarked." ' Baron Larrey, in his useful work,' describes the plans adopted by the French in the Italian war of 1859. At Constantinople, during the Crimean war, the French were apparently very well instaUed ; the best buildings in Constantinople were assigned to them, and they were an-anged with all the accuracy of organization which distinguishes the French. The results were not, however, favorable, especially in the spring of 185G, when typhus spread through many of the hospitals, and caused great mortality.' Taught by this experience, in the Italian war of 1859 the French distributed theu- sick in small hospitals whenever they could find a building, and in this way the extension of the specific diseases was entirely stopped. In the great Franco-Prussian war of 1870-71, the Germans made great use of temporary hospitals, and distributed their sick and wounded over almost the whole of Germany. The plans were very similar to those used in the Crimean and American wars. In some of the large cities, as at Ber- lin, immense hospitals, with railways and every apphance, were fitted up. The expeiience as regards hospital gangrene and erysipelas was favorable, but there were many cases of pyaemia in some of these hospitals. To sum up, the hygiene of field hospitals in war (the rules are derived fi'om our own Crimean experience, and that of the wars which have taken place since) is as follows : — The field, including the intermediate, hospitals to be made of tents ; the tents being well constructed, of good size, thor- oughly ventilated, the flaps being able to be raised so as almost, if desu-ed, to make the tent into an awning. The most convenient and best ai'e the hospital marquees of the new pattern, except for their considerable weight. The new double circular tents will now be used«in all probability : they are a great improvement on the old bell-tent, and lighter than the marquee. Each weighs 100 ft dry, and four patients are put in a tent. For opera- ting purposes, the central pole can be removed and a tripod support sub- stituted, so as to leave the centre free. The ground round the tents to be thoroughly drained, kept very clean, and replaced from time to time. The tent floor to be covered with clean, and, if possible, dried earth, or charcoal, and to be then covered mth a waterproof cloth, or boarded, if the camp be one of position. In either case the greatest care must be taken that the ground does not get soaked and filthy. Eveiy now and then (if possible every ten days or so) the tents should be shifted a httle. If it can be done, the sick should be raised off the ground. Iron bed- steads are cumbrous, but small ii-on pegs stuck in the ground might carry a sort of cot or hammock. The advantage of a plan of this kind is that by means of holes in the sacking wounded men can have the close-stool without much movement. For fever cases it permits a free movement of air under the patient. ' On Hygiene, p. 397. - Notice sur I'Hygiene des H.'pitaux Militaires, 1862. ^ Larrey mentions some striking instances of the effects of overcrowding. At Rami- Tchifflick,'the hospital was fixed for 900 by the surgeon in charge, who allowed no more ; it remained healthy. His successor increased the beds to 1,200 and then to 1,400. Typhus became most severe, and spared no one {ni injirmiers, ni sceurs, ni medemu). In the hospital at Pera there was the same mistake and the same results. Typhus caused 50 per cent, of the deaths. At the hospital of the Fcole Militaire no crowding was permitted, and typhus caused only 10 per cent, of the deaths. In the French am- bulances in the Crimea the same facts were noticed. Double and treble numbers were crowded into some, and they were ravaged by typhus ; others were not allowed to be crowded, and had little typhus. WAR. 377 The stationary general hospitals in rear slionld be of tents or wooden huts, but never of convei-ted buildings, or of hospitals used by other na- tions. Here, of course, iron bedsteads, and all the appurtenances of a regular hospital, are brought into play. ^\nienever practicable, the rear hospital should have water-closets and sewers. At Kenkioi, in Turkey, IVIr. Brunei supphed square wooden sew- ers about fifteen inches to the side ; they were tarred inside, and acted most admirably, without leakage, for fifteen months, till the end of the war. The water-closets (Jenuing's simple siphon), arranged with a small water-box below the cistern to economize water, never got out of order, and, in fact, the drainage of the hospital was Hterally perfect. Dr. Parkes had little doubt such weU-tarred wooden sewers would last two or thi'ee years. Thei-e is one danger about wooden hospitals, viz., that of fii-e. The huts should, therefore, on this gTound alone, be widely separated ; each hut should have, about ten feet from it, an iron box for refuse. Wooden boxes do not answer, as in the winter hve cinders get thi'own in, and there is danger of fire. These boxes should be emptied eveiy morning by the scavengers, and the contents burned as soon as possible. Water must be laid on into every ward. The arrangement of the buildings is a simple matter, but must partly be determined by the ground. Long open lines are the best. An hospi- tal of this kind, completely prepared in England, can be put up at a very rapid rate,' supposing there be no great amount of earth-work, and that the supply of water and of outlet for sewage be convenient. So that, if commenced at once at the beginning of a campaign, accommodation would soon be provided. Circumstances may of course render it necessary to take existing build- ings for hospital purposes, but it ought always to be remembered that it is running a very great risk, and nothing but rigid necessity ought to sanc- tion it. Laundry Establishment. This part of an hospital must be organized as early and as perfectly as possible. The different parts must be sent out from England, viz., boiler, drying-closet, washing-machines, and wringing-machines. The washing in war can never be properly done by the people among whom the war is car- ried on. Every appliance to save labor must be used, and after calcula- ting what amount of laundry work has to be done for a presumed number of sick, just twice the amount of apparatus should be sent out, partly to insure against breakage, partly to meet moments of gi*eat pressui-e. The drying-closet, especially, is a most important part of the laundry, as its heat can be used to disinfect. ' The hospital at Renkioi, in Turkey, in the Crimean vrar, was made of such large huts (50 men in each) that its rapidity of erection is no guide to others ; yet it was mar- vellously soon put up. The first beam was laid on May 24, 185.5 ; on July 12th it was reported ready for 800 sick, every ward having water laid on, baths and closets, and an iron kitchen and laundry being also ready ; on August 11th it was ready for 500, and on December 4th for 1,000 sick. In January, 1856, it was ready for 1,500 sick, and in a short time more 2,200 could have been received. The number of English artisans was only forty, but we had native workmen, and if we had had eighty English arti- sans it would have been ready for 1,000 sick in three months. Smaller huts could be put up in much less time if the ground requires no terracing. 378 PRACTICAL HYGIENE. Amount of Hospital Accommodation. This must not be less than for 25 per cent, of the force, with reserve tents in rear in case of need. Cemeteries in war must be as far removed as possible ; the graves dug deep, and peat charcoal thrown iu if it can be prociu-ed. Lime is gener- ally used instead, but is not quite so good. If charcoal cannot be got, Hme must be used. If the army is warring on the sea-coast, burial in the sea might be employed. But cremation would be best, and forms of ambula- tory furnaces have been proposed. Sanitary Duties connected unth a War Hosjntal. In addition to the usual sanitary duties of an hospital, there are one or two points which require particular attention in the field. The first of these is the possible conveyance of disease by the exceed- ingly dirty clothes, which may perhaps have been worn for weeks even without removal, in the hard times of war. Typhus, especiaUy, can be carried in this way. To provide for this, every hospital should have a tent or building for the reception of the clothes ; here they should be sorted, freely exposed to ah', and the dirty flannels or other filthy clothes picked out. Some of these are so bad that they should at once be burnt, and the principal medi- cal officer, at the beginning of a camj)aign, should have authority given him to do this, and to replace the articles from the public store. The articles which are not so bad should be cleansed. The cleansing is best done in the following way : — If the hospital have a laundry and dry- ing-closet, they should be put first in the drying-closet for an houi', and the heat carried to 220° Fahr. Then they should be transferred into the fumigation box ; this is simply a tin-hned box or large chest. The clothes are put in this, and sulphur placed above them is set on fire, care being taken not to burn the clothes ; or nitrous acid fumes should be used. After an hour's detention in the fumigating box, they should be removed to the soaking tubs. These are large tubs with pure water, put in a shed or tent outside the laundry. A little chloride of lime can be added to the water. They should soak here for twenty-foiu' hours, and then go into the laimdry and be washed as usual. This plan, and especiaUy the heating and fumigation, will also kill Hce, which often swarm in such numbers. Another point of importance is to bathe the men as soon as possible. The baths of a war hospital at the base of operations should be on a large scale, and the means for getting hot water equally large. The men's heads, if lousy, should be Avashed with a little weak carbohc acid, which kills the hce at once. The smell is not agreeable, but that is not of real consequence. In a war hospital, also, the use of charcoal in the wards, antiseptic dressings, the employment of disinfectants of all kinds, is more necessary than in a common hosj)ital. As a matter of diet, there should be a large use in the diet of antiscor- butic food, vegetables, etc., and antiscorbutic drinks should be in every ward, to be taken ad libitum — citric acid and sugar, cream of tartar, etc. The bread must be very good, and of the finest flour, for the dysenteric cases. WAE. 379 Siegei The sanitary duties during sieges are often difficult. "Water is often scarce, disposal of sevrage not easy, and the usual modes of disposal of the dead cannot, perhaps, be made use of. If sewage is not Tvashed a^vay, and if there is no convenient plan of removing it by hand, it must be burnt. Mixing it "m.th guxipowder may be adopted if there is no straw or other combustible material to put with it. If food threaten to run short, the medical officer should remember how easily Dr. Morgan's process of salting meat can be apphed, and in this way cattle or horses which are killed for want of forage, or are shot in action, can be preserved. For sieges, as vegetables ai-e sure to fall shori, a very ample supply of lemon-juice and of citric acid, citrates, and cream of tartao: should be laid in and distributed largely. One other point should be brought to the notice of the general in com- mand. In times of pressui'e, every man who can be dischai'ged from the hospital is sent to the front. This cannot always be avoided. But when there is less pressure, the men should go from the rear hospitals to a de- pot, and while there should still be considered under medical ti-eatment, so that they may not too soon be subjected to the hardships of war. They should, in fact, be subjected again to a sort of training, as if they were just entering on the war. If this is not done, a number of sickly or half-cured men get into the ranks, who may break down in a moment of emergency, and cause gi'eat difficulty to the general in command. Some officers think that a man should either be in hospital or at his full duty ; this seems a misapprehension both of the facts and of the best way of meeting them. To transfer a man just cured, fi'om the comforts of a hospital at once to the fi'ont, is to inin great danger. A depot, which should be a sort of convalescent hospital, though not under that term, is the proper place to thoroughly strengthen the man just recovered for the arduous work before him. APPENDIX A. STANDAED SOLUTIONS FOE VOLUMETEIC ANALYSIS. 1. For Clilorine. (a) Silver Nitrate Solution. 4788 grammes of silver nitrate in 1 litre of distilled water. 1 CC. of solution = 1.00 miDigramme of chlorine. " " =1.51 " of ammonium chloride. " " = 1.65 " of sodium chloride. " " = 2.10 milligrammes of potassium chloride. This solution may be standardized with a solution of pure sodium chloride, 1.648 to the litre, 1 CC. of which equals 1 mgm. of chlorine. (6) Potassium Monochromate Solution. — 50 gi-ammes of potassium mono- chromate are dissolved in one litre of distilled water. Solution of nitrate of silver is added until a permanent red precipitate is formed, which is allowed to settle. 2. Hardness. (a) Soap Solution. Dissolve some soft soap (pharmacopoeial) in diluted spirit, and graduate by means of this barytic solution. Nitrate of barium 0.26 gramme. Distilled water 1 litre. 2.2 CC.s (or 22 measuj-es) of standard soap solution produce a per- manent lather with 50 CC.s of the the above solution. 1 measure (= y\ CC.) of soap solution = 0.00025 gm. = 0.25 mgm. of calcium carbonate. Con-ection for lather = — 2 measures of soap. Short factors (when 50 CC.s of water are taken for experiment). For degi-ees of Clark's scale (1 : 70.000) = 0.35. " Metrical " (1 : 100,000) = 0.50. (6) A weaker solution, each measure (^-^ CC.) of which is equal to 0.07 mgm. of CaC03 is sometimes used. The correction for lather would be 7 measm-es of soap. The corrected number of measures, divided by 10. gives the hardness in Clark's scale directly, or multiplied b}' 0.14 the degrees on the metrical scale. APPENDIX. 381 3. Solutions required for the determination of Oxidizable Matter m Water. (a) Permanganate Solution. 0.395 of potassium permanganate in 1 litre of water. 100 CC.s are exactly decolorized by 100 CC.s of oxalic acid solution (c). (See No. 7.) 1 CC of permanganate solution used with acid yields 0. 10 milligramme of oxygen. 1 CC. of permanganate solution used with alkali yields 0,06 milligramme of oxygen. 1 CC. of permanganate solution exactly oxidizes 0.2875 mgm. nitrous acid (NO J. 1 CC. of permanganate solution exactly oxidizes 0.2125 mgm. hydro- gen sulphide (H„S). 1 CC. of permanganate solution exactly oxidizes 0.7000 mgm. iron (Fe). 0.9000 " ferrous oxide (FeO). (b) Potassium Iodide Solution. — A 10 per cent, solution of the pure potassium iodide, reciystallized from alcohol. (c) Dilute Sulphuric Acid. — One volume of pure sulphuric acid is mixed with tlu'ee volumes of distilled water, and permanganate solution dropped in until the whole retains a very faint pink tint, after warming to 80° F. for foiu- hours. (d) Sodium Hyposulphite. — One gramme of crystallized sodium hyposul- phite dissolved in 1 htre of water. (e) Starch Solution. — One gramme of starch to be intimately mixed with \ litre of distilled water, the whole boiled briskly for five minutes, filtered, and allowed to settle. 4 Solutions for determination of Free and Albuminoid Ammonia. (a) Ammonium Chloride Solution for JSesslerizing. 0.315 gTamme cf ammonium chloride in 1 litre of water. This is the strong solution. * Take 100 CC.s of this solution and dilute to 1 litre. This is the standard solution. 1 CC.= 0.01 milhgramme of ammonia (NHJ or 0.0082 mgm. of nitrogen. (&) Nessler's Solution. — Dissolve 35 grammes of potassium iodide in 100 CC.s' of distilled water. Dissolve 17 grammes of mercuric chloride in 300 CC.s of distilled water ; warm if necessarj', and allow to cool. Add the mercuric solution to the iodide solution until a perceptible permanent precipitate is produced. Then dilute with a 20 per cent, sodium hydrate solution (caustic soda) up to 1,000 CC.s (1 litre) : add mercuric chloride solution until a permanent precipitate again forms ; allow precipitate to settle, and then decant off the clear solution. (e) Sodium Carbonate (sometimes requu'ed for free ammonia, but not usually needed). — A 20 percent, solution of recently ignited pure sodium carbonate. 382 PRACTICAL HYGIENE. (d) Alkaline Potassium Permanganate Solution (for Albuminoid Ammonia), — Dissolve 200 grammes of potassium liydrate and 8 gi-ammes of pure potassium peiTuanganate in 1,100 CC.s of distilled water, and bod the solution rapidly till concentrated to 1,000 CC.s. (e) Distilled Water free from Ammonia. — The S. P. A. recommend boiUng ordinaiy distilled water with 1 per 1,000 of pure ignited sodium car- bonate. If the water is distilled with a little phosphoric acid (as recommended by Xotter), it comes over quite free. Test with a little Nessler's solution. 5. Be-agentsfor the determination of Nitric Acid in Nitrates. (a) Jletallic Aluminum. — As thin fod. (6) Solution of Sodium Hydrate. — Dissolve 100 grammes of solid sodium hydi'ate in 1 litre of distilled water. "\Mien cold, introduce a strip of about 100 square centimetres, say 15 square inches, of aluminum foil, previously heated to just short of redness, wi-apped round a glass rod ; when the aluminum is dissolved, boil the solution briskly in a porcelain basin until about one-third of its volume has evapo- rated ; allow it to cool, and make it up to its original volume with water free from ammonia. The solution must be tested by a blank exjDeriment to prove the absence of nitrates. (c) Cojyper Sulphate Solution. — Dissolve 30 gi-ammes of pure copper sul- phate in 1 litre of distilled water. (d) Metallic Zinc, pure. — As thin foil. This should be kept in a dry at- mosphere, so as to be preserved as far as possible from oxidation. To make the icet Copper Zinc copjple. — Put into a flask or bottle a piece of clean zinc foil, and cover it with the copjoer solution (c) : aUow the foil to remain until it is well covered with a firmly adheiing black deposit of copper. (If left too long the deposit may peel off in washing.) Pour off the solution (which may be kept for further use), and wash the conjoined metals with distilled water. The coj^ple is now ready for Use. About one square decimetre (=^ of a square inch) should be used for every 200 CC.s of a water containing 5 parts or under of nitric acid in 100,000, For waters richer in nitrates more will be required. (e) Standard Solution of Anunonium Chloride {see 4: {a)). ' (/) Nessler's Solution {see 4 (6)). 6. Re-agents for the determination of Nitrous Acid in Nitrites. (a) Solution of Jletapheni/lenediamine. — Dissolve 5 grammes of metapheny- lenediamine in 1 htre of distilled water, rendered acid with sul- phuric acid. Decolome, if necessary, with animal charcoal (6) Dilute Sulphuric Acid. — One volume of pure sulphuric acid to two volumes of distilled water. (c) Solution of Potassic Nitrite. — Dissolve 0.-406 gramme of pure silver nitrite in hot water, and decompose it with a slight excess of potas- sium chloride. After cooling, make the solution up to one litre, allow the chloride of silver to settle, and dilute each 100 CC.s of the clear supernatant Hquid again to one litre, 1 CC, of this diluted solution =: 0,01 of a milligramme of X0„. The nitrites may also be determined by the permanganate solution {see 3). APPENDIX. 883 7. For determination of Phosphoric Acid. One part of pure molybdic acid is dissolved in 4 parts of ammonia, sp. gr. 0.960. This solution, after filtration, is poured, with constant stirring, into 15 parts of nitric acid of 1.20 sp. gT. It should be kept in the dark, and carefully decanted from any precipitate that may form. 8. Sulphuric Acid Solution for Carbonates in Water. Take 4.9 grammes by weight of pure H.^SO^ and dilute to 1 litre. 1 CC. saturates 5 miUigrammes of calcium carbonate. 6.2 " of sodium 9. Alkaline Solution for Acidities. Take liquor sod^ or liquor potassse of pharmacopoeial strength, and dilute with 8 or 9 parts of distilled water. Graduate with oxalic acid solution {a). [See No. 7.) 1 CC. of standard alkaline solution = 6.3 mgm. oxalic acid. = 6 " glacial acetic acid. = 9 " lactic acid. = 7.5 " tartaric " = 6.4 " citric " 10. Oxalic Acid Solutions. Solution (a) — Take 6.3 grammes of crystallized oxalic acid, and dis- solve in one htre of water. 10 CC.s exactly neutralize 10 CC.s of standard alkaline solution. Solution (6) — Take 100 CC.s of solution (a) and add 180 CC.s of dis- tilled water ; or, dissolve 2.25 gTammes of crystallized oxalic acid in one litre of distilled water. This makes the solution for testing the alkalinity of lime or baryta water. 1 CC. exactly neutralizes 1 milligramme of lime (CaO.) 2.73 " of baryta BaO. Solution (c) — Take 100 CC.s of solution (a) and add 700 CC.s of dis- tilled water ; or, dissolve 0. 7875 gramme of crystaUized oxaUc acid in one litre of distilled water. This is the solution for graduating the permanganate. 100 CC.s exactly decolorize 100 CC.s of permanganate in presence of sulphuric acid. 11. Copper Solution (Fehling's) for Sugars. Take of pure copper sulphate 34.64 grammes. | 2){ssoZt;e < " distilled water 200 CC.s. [ Take also of tartrate of sodium and potassium, 173 grammes. ) nvgoQ/yg Solution of caustic soda (or caustic potash) . . 480 CC.s. .| Mix the two solutions slowly, and dilute with distilled water to one htre. 1 CC. is reduced by 5 milligrammes of either glucose or inverted sugar. 1 CC. " 6.67 " of lactin (or milk sugar). 12. Iodine Solution for Hxjdrogen Sulphide. Dissolve 6.35 grammes of iodine in 1 litre of distilled water by the aid of a little potassium iodide. 1 CC.= 0.85 milligramme of H^S. 384 PRACTICAL HYGIENE. If a litre of water be taken for examination, the short factor for cubic inches per gallon is 0.1G4. Starch is used as the indicator. 13. Solution of Iron for Colorimetric Test. Dissolve one gramme of pure iron wire in nitro-hydrochloric acid ; precipitate the feme oxide ■^-ith ammonia ; wash the precipitate ; dis- solve in a Httle hydrochloric acid, and dilute to 1 htre. 1 CC. = 1 milligramme of u'on. This is the strong solution. For use it is diluted 1 to 100, so that 1 CC. = 0.01 milligramme of metallic iron. ICC. = 0.027 " of iron phosphate. 14. Dilute Acid Solutions are generally 1 part of acid to 9 of distilled ■water. unless otherwise specified. 15. Qualitative Solutions, and, generally, solutions that ai-e not titrated or graduated, are saturated, unless otherwise specified. 16. Brucine Solution (for Nitric Acid). — 1 gramme of brucine to 1 htre of distilled water. 17. Solution of Potassium Iodide and Starch (for Nitrous Acid). Potassium iodide 1 gramme, starch 20 grammes, water 500 CC.s. Make the starch, filter when cold, and then add the potassium iodide. This mixture does not keep well, and must be made fresh from time to time ; or, the solutions 3 (6) and 3 (e) may be used instead. 18. Solution of Gold Chloride (for Oridizahle Matter in "Water). — One gramme of gold chloride dissolved in 1 litre of water. 19. Solution of Cochineal (for Acidities or Alkalinities). — Take 5 grammes of cochineal, bruised in a mortar, add 25 CC.s of S2:)irit of wine and 500 CC.s of distilled water ; filter. This solution is ajDt to become a Httle acid. 20. Phenol-Phthaleine Solution (for Acidities or Alkalinities). — Take 5 gi'ammes of the phenol-phthaleine, and dissolve, "nith the aid of 25 CC.s of spii'it of wine, in 500 CC.s of distilled water. 21. Use of Sikes' Hygrometer, for ascertaining the strength of spmts. A sample of the spirits to be tested is poiu-ed into a trial glass, and the temperature ascertained by means of a thermometer in the usual way. The hydrometer is taken, and one of the weights is attached to the stem below the ball ; it is then pressed down to the on the stem. If the right weight has been selected it will float up to one of the divisions on the stem. The number on the stem is then read off and added to the number on the iveight ; the sum is called the indication. The book of tables is then opened at the temperature fii-st found, and the indication looked for in one of the columns ; opposite it will be found the strength of the spirits over or under APPENDIX. 385 proof. If at the temperature 60° F. the indication is 58.8, then opposite this will be found zero, that is, the spuit is the exact strength of proof. If the indication is 50, then opposite that is 12.8, or the spirit is 12.8 over proof; if the indication is 70, then opposite is 18.9, or the spirit is 18.9 under proof. The meaning of these expressions is — (1) If the spirit be 12.8 over proof, then, in order to reduce it to pi-oof, 12.8 gallons of water must be added to 100 gallons of the spirit ; the resulting mixture will be proof ; (2) if the spirit be 18.9 under proof, this means that 100 gallons contain only as much alcohol as 89.1 {i.e., 100-18.9) of proof spirit; to raise it to proof it would have to be mixed with an equal quantity of spirit as much above proof as it is below it, so that '- — — '— = 100. The " Adulteration of Food and Drugs Amendment Act," 1879, allows brandy, whiskey, or rum to be 25 degrees under proof; equal to 42.6 per cent, of absolute alcohol, volume in volume, or 34.1 per cent, of weight in volume. This gives a sj)ecific gTavity of .947. Gin is allowed to be 35 degrees tmder proof, equal to 36.9 per cent, volume in volume, or 29.5 per cent, weight in volume of absolute alcohol. This gives a specific gi'avity of .956. Proof spirit contains 56.8 volume in volume, or 45.4 weight in vol- ume of absolute alcohol, sp. gr. .920. The presence of sugar or extractives renders the use of the hydi-ometer fallacious imless the spirit is distilled off. APPENDIX B. METEICAL WEIGHTS AND IVIEASTJEES. a. Length. 1 Metre = 39.37 English inches = 3.28 feet. 1 Decimetre = 3.94 " " = (4 inches nearly). 1 Centimetre = 0.39 " " = (y% inch nearly). 1 MiUimetre = 0.039 " " = (gV inch nearly). N.B. — The Latin prefix indicates division. The Greek " " multiphcation. 1 Kilometre — 1,000 metres = 1,094 yards = fth mile (nearly). 1 IVIile (EngUsh) i= 1,609 metres, or 1.609 kilometre. h. Area. 1 Square Metre = 10.76 sq. feet — 1,542 sq. inches. 1 Square Centimetre = 0.154 sq. inch = tj sq. inch (nearly). 1 Square Millimetre = 0.0015 " = e io " (nearly). 100 Square Metres = 1 are = 119.7 square yards. 100 Ares r= 1 hectare = 11967.0 " " = 2.47 acres. 100 Hectares = 1 square kilometre = 247 acres = 0.386 sq. mile. Vol. II.— 25 386 PRACTICAL HYGIENE. c. Capacity. 1 Decimetre cubed = 1 litre = 1,000 cubic centimetres = 61 cubic inches = 35.3 ounces = 0.22 gallon. 1 Cubic centimetre = 0.061 cubic inch. 1 Cubic inch = 16.4 cubic centimetres. 28.35 Cubic centimetres = 1.733 cubic inch = 1 ounce. 1,000,000 Cubic centimetres = 1,000 litres = 1 cubic metre = 1 stere = 35.3 cubic feet. d. Weight. 1 Cubic centimetre of distilled water at 4** C. (39.2° F.) weighs 1 gramme. 1 Gramme = 15.432 grains. 1 Decierramme = 1.543 grain (= 1^ gi-ain nearly). 0.154 " (= T7 gi'ain nearly). 0.015 " (= -^ grain nearly). 1,000 gi'ammes = 15,432 grains = 2.2 lb auozr. =35.3 Centigi-amme = ^Milligramme = Kilogramme = ounces. French livre and German ^wn^i = The German loth = 1 ib avoir. = 453.5 grammes. 1 ton avoir. = 1,018 kilogrammes. 500 grammes= 1.1 ft) = 17.6 ounces. 16|- " = ^ ounce nearly. APPENDIX C. THERMOMETEK SCALES. Centigrade _ Reaumur _ Fahrenheit — 32 5 ~ 4 ~ 9 Centigrade. Reaumur. Fahrenheit. Mercury freezes at -40°.0 -17.7 0.0 4.0 10.2 15.5 25.8 38.5 78.3 100.0 360.0 -32°. -14.2 0.0 3.2 8.2 12.4 20.6 30.0 62.7 80.0 288.0 -40.0 Zero of Fahrenheit 0.0 Water freezes at 32 Water at its maximum density at Mean temperatiu'e of London 39.2 50.4 Mean temperature for specific gravities, etc. Mean temperature of Calcutta 60.0 82.0 Mean tempei-ature of the human body . . . Alcohol boils at 98.4 173.0 Water boils at 212.0 Mercury boils at 680.0 APPENDIX. 387 APPENDIX D. BAEO^ilETEK SCALES. Standard pressure = 760 millimetres = 29.922 inclies. 30 inches = 762 29.5 " = 749 29 " = Idl 28.5 " = 724 28 " = 711 1 inch = 25.4 APPENDIX E. 1. Table showing the daily yield of Water from a Eooficith varying Eainfalls.^ Area of House, 10 by 20 feet, or 200 square feet. Mean fiainfalL Loss from Evaporation. Requisite capacity of Tank. Mean daily yield of Water. Mean d lily yield of Water in wettest year. Mean daily yield of Water in driest year. Inclies. Per cent. Cubic feet. Gallons. Gallons. Gallons, 20 25 100 4.3 6.7 3.2 25 20 135 5.7 7.5 3.9 30 20 145 6.8 9.4 45 35 20 155 7.9 11.0 5.0 40 15 165 9.7 13.1 7.2 45 15 170 10.9 14.2 8.6 For any other size of roof or amount of rainfall, the numbers will be proportional. 2. Tables showing the Distribution of Positive and Negative Errors, accord- ing to Number of Events. ■ (a) 1 Event. Chances. 1 positive 1 1 negative 1 Total 2 (&) 2 Events. Chances. 2 positive 1 1 positive, 1 negative 2 2 neo-ative 1 Total 1 From a paper by H. So^erby-Wallis, F.M.S., on Rainfall Collection, Transac- tions of the Sanitary Institute of Great Britain, vol. i., 1880 (Croydon Congress), p. 213. 388 PEACTICAL HYGIENE. (c) 3 Events. Chances. 3 positive 1 2 positive, 1 negative 3 1 positive, 2 negative 3 3 negative 1 Total 8 {d) 4 Events. Chances. 4 positive 1 3 positive, 1 negative 4 2 positive, 2 negative 6 1 positive, 3 negative 4 4 negative 1 Total 16 (e) 10 Events. Chances. 10 positive 1 9 positive, 1 negative 10 8 positive, 2 negative 45 7 positive, 3 negative 120 6 positive, 4 negative 210 5 positive, 5 negative 252 Carry forward 638 Brought forward .... 638 4 positive, 6 negative 210 3 jDositive, 7 negative 120 2 positive, 8 negative 45 1 positive, 9 negative . 10 10 negative 1 Total 1,024 In each case the number of chances correspond to the coefficients of a binomial whose exponent is the number of events. Thus, with 1 event we have {a + hy = a + h ; with 2 events we have {a + by — a" +2a6 + h\ and so on. AMERICAN APPENDIX TO PARKES' HYGIENE INTRODUCTION. The fundamental principles of hygiene underlying all measures aimed at the improvement of the health of mankind so carefully brought out in the preceding pages are, of course, apphcable to all countries, chmates, and habits of living ; but there is very much that is of a practical nature, apphcable to England and English ■n-ays which it would be impossible to follow in the United States, where existing conditions of chmate, govern- ment, density, and movement of j)opulation are so totally different. For this reason it has been thought best to supplement the theoretical part of the treatise bearing Dr. Parkes' name by a short sketch of American prac- tice in matters relating to pubhc health, and the progress that has been made in sanitary science -during the last few years. Although for many years a department for the study of subjects relat- ing to State medicine, and for the employment of such methods as would tend to improve the health of the nation, has had its place in the internal policy of England, it was not till the year 1869 that any measures looking to the same results were inaugurated in America. In that year Massachu- setts created a State board of health, and gi-aduaUy other States have fol- lowed her example till twenty-nine now have their departments of health. The creation of these boards of health has been the outcome of a grad- ually gTowing public recognition of the need for concerted action in the prevention of disease, a feeling that received great impetus during the epidemic of 1878. Much of this interest is, however, due to the fact that it can now be proved that a large proportion of the deaths that occur an- nually from contagious or infectious diseases might be prevented, and the average dui'ation of human life considerably lengthened thereby. As the education of the pubhc increased, so did the demand for accu- rate knowledge concerning the causes of disease and the methods for its prevention. Laws were enacted in several States creating boards of health, which should make these investigations, and the system was completed when, in 1879, Congress created the National Boai'd of Health, whose duty it should be to make investigations into the causes and means of prevention of contagious and infectious diseases, to initiate measures of national im- portance, and to be a centre of information for all matters relating to pub- lic health. So valuable has been the work of this Board, during its short career of four years, that something more than a passing notice seems to be merited. The following sketch of its history and work has been com- piled from notes furnished the writer by Dr. Stephen Smith, a member of the Board, to whom he feels himself greatly indebted : " The National Board of Health was the direct outcome of the great yellow fever epidemic of 1878," which, among other valuable lessons, taught 392 america:n^ appendix to parkes' hygiene. the people that " there are pestilences of a Bational character, which in their devastations, know no municipal or State limits, and that in their control and suppression the National Government should bear its proper share." So thoroughly were the peoj^le roused to the necessity of a department of health at the seat of the central government, that Congress, on assem- bling in December, at once appointed Committees on Ejjidemic Diseases in both Houses, which resulted in the passage, March 3, 1879, of an Act cre- ating a National Board of Health. The Board was composed of seven civilians aj^pointed by the President, who in addition detailed officers from the Marine Hospital Service, War Dejjartment, Navy Department, and Department of Justice, to act as ex-officio members. Owing to the nearness of the several Departments, the ex-officio members, forming, to- gether with two of the appointed members, the Executive Committee, could be summoned in a few moments to the rooms of the Board. " No emer- gency, however urgent, could, therefore, occur which it was not possible to meet properly and timely." The full committee was called whenever the exigencies of the case demanded it. The members of the Board were rep- resentative men in their several sections, and its executive committee brought to the daily discharge of duty the efficiency of a single hand and the wisdom of the combined experience of the four chief executive depart- ments of the Government. The operations of the Board, under the Act, were : 1, the collection of information, from health organizations and sanitarians, as to the best plan for a national public health organization ; 2, the collection of information regarding the sanitary condition of some of the principal cities and towns of the United States ; 3, the appointment of a commission to investigate yellow fever in the Island of Cuba ; 4, the collection and collation of the sanitary laws of the United States and of the several States ; 5, an investi- gation as to the best method of determining the amount and character of the organic matter in the air ; 6, an investigation into the efl'ects of disin- fectants ; 7, an investigation as to the composition and merits of patent disinfectants ; 8, an investigation regarding the prevalence of the adulter- ation in food and drugs ; 9, a preliminary inquiry with regard to the dis- eases of food-making animals ; 10, an examination of the flow of sewers in relation to their sizes and gradients ; 11, a sanitary survey of the eastern coast of New Jersey bordering on New York Harbor ; 12, a sanitary survey of the city of Memphis ; 13, an inquiry as to the hygiene of the mercantile marine ; 14, an investigation of the outbreak of diphtheria in Northern Vermont ; 15, an investigation as to the influence of various soils upon sanitation, especially with regard to drainage and methods of disposal of excreta. In June, 1879, the Board was given additional power by Act of Con- gress, enabling it to act efiectively in case of a reapjiearance of yellow fever. The Bulletin, published under this act, was recognized as " one of the most important sanitary periodicals in the world, as it contained, not only a complete summary of the progress of epidemic diseases in all countries, and of the state of the public health of every city of the United States and of the seaport towns of the world, but in it appeared all the investigations of the committees of experts appointed by the Board." In order to meet the ap2:)rehended reappearance of yellow fever, sets of rules and regulations were carefully prepared, one to be enforced on rail- roads, another at seaport quarantine, and the third for steamboat and river travel and traffic. Owing to the efficient way in which these regulations LNTRODUCTION. 393 were carried out " travel and traffic was but little imj)eded, where the year previously it was entirely suppressed by the shot-gun policy, or com- plete non-intercourse." /.Ithough the work of the National Board was en- larged so as to reach every threatened community in the Mississippi Valley and on the Gulf Coast, its operations were strictly limited to aiding local and State authorities in theii- struggle with the epidemic. The experience vdth this epidemic j>roved conclusively the value and necessity of a central health organization at Washington, and also that "when there is concert of action among the health authorities of the States and the National Board of Health, the most destructive and irrepressible pestilence known cannot make headway ; but may not only be controlled, but completely sup- pressed." To prevent the recurrence of the epidemic, preventive measures were adopted, one of the most important of which was the creation of insular refuge stations at points on the Atlantic and Gulf coasts, where aU infected vessels could be quickly cleaned and disinfected before they entered the harbors of seaport towns. They were designed to aid local quarantines which had not the means to provide all the apparatus necessary for the immediate cleaning of vessels. Of their value to the seajDort towns of the Gulf and Atlantic coasts, the health authorities of those sections bear the most positive testimony. The International Sanitary Conference, held in Washington early in 1881, was at the invitation of the National Board, and the propositions there agreed upon " will doubtless be the basis of international co-opera- tion to prevent the Si3read of epidemic diseases." In 1882 the Board organized and carried out, in co-operation with State and local Boards, a system of inspection of emigTants, with a view to the suppression of small-pox which was being introduced into the Western States by unvaccinated persons. Previously to the organization of this service, severe outbreaks of small-pox were of almost daily occin-rence in this section ; but when it was fully developed, they decreased in frequency and soon ceased to occur. The circumstances that led to a suspension of the work of the Board can best be given in Dr. Smith's own words. "Among the appropriations set apart annually by Congress for the use of the National Board of Health was $100,000, as a contingent epidemic fund. This fund was to be used at the discretion of the Board, and with the approval of the Secretary of the Treasury, in the aid of local health authorities, for the control and suppression of epidemics. Although yel- low fever appeared at one or two points in 1880 and 1881, yet the Board was able to meet the contingencies which occurred with its ordinary ap- propriations, and turned over to the Treasury, at the close of each year, the $100,000. In 1882 the $100,000 was, as usual, set apart by Congress, among the appropriations for the Board, as a contingent epidemic fund, but with the proviso that it was to be used at the discretion of the Presi- dent. The President transferred that discretion to the Secretary of the Treasury, who decided to confer upon the Marine Hospital Service (a branch of the Navy Department) power to perform all of the required sanitary work, and disburse therefor the epidemic fimds. In this man- ner, the functions of the National Board of Health were, without legisla- tive action, transferred to another branch of the service. In the following- year, 1883, the Secretary of the Treasury made the same disposition of the fund, and the Marine Hospital Service assumed the duties imposed. Meanwhile the general appropriations to the National Board were with- 394 AMERICAN APPENDIX TO PARKES HYGIENE. held, and on June 2, 1883, the Act of June 2, 1879, expu-ed. At the close, therefore, of the fourth year of its labors, the National Board of Health practically ceased operations. Of the vast service which it rendered to the country during its shoi-t, active existence, in the control and suppi-es- sion of epidemic diseases, the health authorities of the country, and the people of the Mississippi valley, bear gi-ateful testimony. Of the value of the great number and variety of investigations into the obscure origin, and the methods of prevention of pestilential diseases which it instituted, and, for the most part, earned to their final determination, scientific men in all parts of the civihzed world have expressed their appreciation. What- ever may be the future destiny of the present National Board of Health, it has accomphshed one important result, viz. : it has demonstrated the fact that there must be a permanent department of public health in the gen- eral government." Although the existing State Boards of Health, in their reports, show, in most instances, gi-atifying progress, theu' usefiilness is often seriously in- terfered with, first, by a lack of public recognition of the importance of their work, and a consequent unwillingness on the part of State and mu- nicipal authorities "to appropriate an3i;hing like the amount of funds needed to secure the canying out of measures necessary to secure the pub- He health ; " and second, by the appointment of members Avho have ex- ceedingly vague ideas in regard to their duties as health officers. In spite, however, of much that is discouraging, these boards are doing much to control disease as well as collecting data showing the physical conditions of the States in their relations to health and disease, such as that relating to natural and artificial drainage, water-supply, forests, rainfall, climate, etc. The relations between damj^ness of soil and consumption ha\ing been shown by Dr. Bowditch to be those of cause and efl:ect, and later by Dr. Buchanan, of London, the subject of subsoil drainage, and the consequent lowering of the level of the gTound-water, is being taken ujd more and moi*e. Without exception, where lands have been reclaimed by embank- ments, or marshes have been drained, malarial fevers have decreased, and the general health of the community has greatly improved. In ^Michigan the decrease in malarial fevers, consequent on di-ainage, is estimated at seventy-five per cent. Vital statistics — though receiving attention from most boards of health — registration is not yet sufficiently thorough to allow of any deductions being made from the returns. The laws are still defective in man}' States, and acciu-ate returns cannot be expected till proper and sufficient legisla- tion is secured. There is little uniformity in the method of publishing the statistics, and no system of registry of physicians and midwives, by which a registrar can know who are properly qualified. Many States seem un- willing to i3ass any laws whatever on the subject of registration. Dr. John S. Bilhngs, in a report to the National Board of Health, says: 'Of the twenty-three States which have had registration laws, only eight have pub- lished statistics which can be said to have any scientific value, and none of them have published results as complete as those attained under the Eng- lish Registration Acts. It v.-iti. be seen also that the supposed, and prob- ably in most cases the real, cause of failure of these registration acts in this country has been the want of sufficient compensation to the register- ing officers, and that the successive amendments to the registration acts that have been made in the States which have secured the best results, have consisted essentially in increasing the pay of the registrars." As an INTEODUCTION". 395 accurate record of the births, marriages, and deaths in any community is absolutely necessary before proper measures can be adopted aiming at the jDreventiou and stamping out of disease, the gradual education of the people to the need of sanitary measures will, no doubt, result in the en- actment of the necessary laws. The State Boards, acting as central bodies, have generally striven to organize Local Boards of Health in the various cities, towns, and villages oftheu' States, whose objects should be : "1st. The creating of channels of information to the people in a form which would most successfully reach the masses, by being placed in the hands of those who could appreciate and would use the information. 2d, The formation of organized bodies through which -the statistics in regard to pubhc health could be gathered from all parts of the State. 3d. To ascertain the existence of preventable causes of disease in therr communities and to destroy these causes." These local boards are increasing in number year by year, as fast as prejudice is removed and the opposition that is j)ersistently offered to them in many towns gives way before accumulated evidence of the -pve- ventable natiu'e of many diseases. In some of the States these boards have almost unhmited authority in their special province, and gi'eat care is therefore required in the appointment of their members, so that no poli- tical considerations or personal schemes shall in any way injure their efficiency. Active and aggressive sanitary journalism has influenced the lay press to devote much space to the consideration of subjects relating to the public health. The popular interest thus awakened has resulted in the forma- tion of sanitary associations which are doing good work in educating the public. The first of these associations formed in this country was the " Sanitaiy Protection Association" of Newport, E. I, which following the plan of a similar organization in Edinburgh, was in its turn followed by those of Lynn, Mass., and Orange, N. J., till at the jijresent time one hundi'ed and seventy communities have like associations. Theu' objects, being about the same in every case, may best be given by an extract from the rales of the Lynn Association. These state that the objects shall be, " 1st. To promote a general interest in sanitary science, and to dispense among the people a knowledge of the means of preventing disease. 2d. To secure the adojDtion by the city authorities of the most effectual methods of improving the sanitary conditions of the city. 3d. To provide its members, at moderate cost, with such skilled inspection as shall secure the proper sanitary condition of their own premises and those of other persons in whom they may be interested." Besides distributing vast numbers of sanitaiy tracts, and information relat- ing to pubhc health, the Newport Association, in 1880, offered prizes " to the jDcrson, not the owner of the house occupied, who shall put his or her premises in the most satisfactoiy condition, and keep them so " for a stated period, and " to the house-owner who shall d© the most in a given time, toward improving the sanitaiy condition of any occupied dwelling." Like anything aiming to improve the condition of mankind, these associa- tions encounter many obstacles. Strangely enough, one of the most formidable with which they have to contend is indifference and ignorance on the part of theii' members. The results, however, that have been attained are such as to make it extremely desirable that other towns and villages should adopt the same plan. This sketch would not be complete if mention was not made of the work of the American Public Health Association. Beginning with a very 396 AMERICAIT APPENDIX TO PAEKEs' HYGIENE. small membership in 1872, this Association has now growni to be one of the largest and most influential of our national societies. It was organized for the mutual benefit and co-operation of health officers and others who are thinkers and workers in the field of preventive medicine. Its consti- tution states that its objects " shall be the advancement of sanitary science and the promotion of organizations and measures for the practical applica- tion of public hygiene." It has done good work in the diffusion of knowl- edge, by providing an audience for those who have made researches into the causes of diseases and the best means of avoiding or preventing them, as well as in urging upon the authorities the importance of sanitary legisla- tion. Little interest was manifested in its meetings until the epidemic of 1878, when the public became suddenly aware of the imiooi'tance of its de- liberations and conclusions. Every subject that can possibly be suggested in the vast field of sanitary research receives careful attention, and the re- ports and papers that are presented at the meetings, together with the dis- cussions that follow, are printed annually, and form a series of volumes containing not only much that is valuable, but also, it is to be regretted, giving space to much that is worthless. Aiming at the same general work of educating the masses, several of the State Boards of Health have adojited the j^lau of holding sanitary con- ventions, or councils, in various towns throughout the State, at intei-wals diu'ing the year, where topics relating to State medicine are freely dis- cussed. In speaking of the conventions in that State, the Secretary of the Michigan Board of Health, in his report for 1882, says: "Their good effects are apparent in the after-results in the to^mis where such conven- tions are held. In most instances the citizens are aroiised to the necessity of establishing and maintaining an effective board of health ; more effi- cient measvu-es are taken for the suppression of outbreaks of contagious dis- eases ; a better understanding of the necessity for cleanhness, good sewer- age, and good ventilation prevails ; the relations between the peoj)le and the health authorities are more cordial, and a stronger support is given to the health officer in his effort to administer the public health laws." Measures for the control of contagious diseases have been introduced by most of the boards, with marked success in man}' instances. The cases, when found, are immediately isolated, and, if jDOSsible, placed in temj)o- rary hospital structures. ' As the result of its experience in deahng with this class of disease, the New York State Board of Health in 1882 distributed to local boards through the State a circular giving directions for procedure in cases of epidemics, with diagrams for the erection of temjioraiy hos- pitals. In the city of New York both small-pox and typhus fever are now considered to be under perfect control. The methods adopted in that city for deahng with these scourges is to isolate a case as soon as discovered, dis- infect the premises where it has been found and closely watch all susjDicious persons till the period of incubation has jDassed. Owing to these measures a threatened epidemic of tjrphus fever last spring was promptly brought under control. The su^bject of vaccination has received a great deal of attention of late, and scarcely a report from a board of health fails to devote space to it, showing that the prejudice that still exists against it in some minds is gradually being removed. It is still, however, a mooted question whether vaccination should be made compulsory or not. Some States, such as Illinois and New York, require public-school children to be vaccinated be- fore entrance, and certificates are given if the operation has been success- ful, without which a child cannot enter a school. Considerable success IlSrTEODTJCTION. 397 has attended the methods pursued in New York City. The Board of Health of that city employs a corps of inspectors, whose duty it is to -visit every tenement-house and public school twice during the year, examining each child, and offering free vaccination to every one in the tenements. From Octoi)er 1, 1874, when this work was begun, to July 1, 1883, there have^ been 130,598 primary, and 452,550 re -vaccinations, making a total of 583,- 148 operations performed by this corps. The records that are kept by the Department show that about ninety-five per cent, of the primary, and about sixty per cent, of the re-vaccinations are successful, and that jDrotection from small-pox is assured in every case. The great numbers of immi- grants that are constantly passing through the city make the mortality re- turns for the year much higher than they would otherwise be, as the cases of small-jDox are confined to this class of the population, the older inhabi- tants that have been successfully vaccinated experiencing comjjlete immu- nity from the disease. The j)ollution of rivers in this country has not yet received the atten- tion it deserves. Special i-eports have been made from time to time, but they, as a rule, cover only the case of the stream under litigation, when riparian or other rights are infringed, and have no bearing on the general subject. Food and di'ug adulteration ha*s received much attention, and four States have passed laws for its prevention. Nothing more, however, than a passing notice of the work in this direction is necessary, as the subject is treated at length in one of the articles that follow. Many of our older cities have sewerage systems that seem to have been the result of chance instead of prearranged and carefully studied method. Flat-bottomed sewers, covered watercourses, and badly constructed oval sewers, which have been aptl}'' described as " elongated cessjDools," are, in some instances, the only means for removing the sewage from the vicinity of dwellings. Cesspools are still in use in many cities, towns, and vil- lages, but are fast disappearing under the vigorous measures of boards of health. Too much cannot be said against then- use under any circum- stances. The almost depopulation of the city of Memphis, in 1878, is a ter- rible example of the loss of life that may be occasioned by their use. Much more attention is now, however, being paid to systematic sewerage ; new towns are employing competent engineers to prepare plans for its proper disposal, and old ones are seeking advice for the improvement of their ex- isting systems. There has been some controversy of late on the compara- tive merits of what are termed the " combined " and " sej^arate " sj^stems, the former providing for the removal of both sewage and rainfall through one set of pipes, and the latter requiring a separate system for each. No hard-and-fast rules can, however, be given for the emj)loyment of either system ; local considerations and future wants should, in all cases, deter- mine the use of either, or a combination of both. Within the past few years the problem of how to remove house waste in suburban districts has been solved by the employment of a system of sub- surface irrigation. The efficiency, simplicity, and comparative cheajDuess of this mode of sewage disposal makes it available for small plots of ground, and at the same time has none of the dangers of the old system of leaching cesspools. Although the condition of our pubhc schools is beginning to receive official attention, and the 'grosser sanitary evils remedied, there is yet com- paratively little interest taken in such matters by the public at large. Much has been done, and is being done ; but those who recognize the evils of 398 AMERICAN APPENDIX TO PARKEs' HYGIENE. imperfect heating and ligliting, uncomfortable seats, defective plumbing and ventilation, crowded rooms, climbing stairs, badly constructed and dii'ty closets, impure water, etc., are often sadly hampered in their efforts at reform by causes that are very well put by Mr. Warren E. Briggs, in a recent report of the Michigan State Board of Health, who classifies them as follows : 1, The stereotj'ped school-house is always before them (the advocates of a better system), and is usually taken as a model for the new building ; 2, Local prejudice against sanitary reform — the ancient inhabi- tant classes it mth all the modern crazes and new-fangled notions ; 3, Penu- rious and short-sighted economy in the appropriation of small sums for the construction of buildings ; 4, The difficulty of obtaining satisfactory data. This last class has, in a great measure, been removed by competi- tion for piizes offered by the editor of the Sanitary Engineer for the best plans for school buildings, which, by directing the attention of architects and others to the matter, has now made it possible to obtain plans for schools of varying size, admirable in construction and ingenious in arrangement. Municipal boards of health have not been behind, and in some instances have led, the State boards in theu- work of sanitary reform. The New York City Board was the first to organize, and being the pioneer in muni- cipal hygiene has borne the brunt of the battle against ignorance. Its methods have been closely watched, and many of its regulations adopted by other cities. Another competition, also originating with the Sajiifary Engineer, was opened in December, 1878, and a prize of $500 was offered " for the best foui" designs for a house for workingmen, in which might be secured a proper distribution of light and pure air, with an arrangement of rooms that would yield a rental sufficient to pay a fair interest on the investment." This competition attracted great attention, and so aroused the pubhc to the evils of the then tenement-house system that "an amendment to the Tene- ment-House Act was passed by the State Legislature, May, 1879, limiting the space to be occupied by any tenement-house to sixty-five per cent, of the lot it occupies, requiring all bedrooms to have windows, with direct Ught and air, and greatly adding to the j)owers of the Board of Health to remedy abuses in such buildings." A very important move was made in 1881, when the State legislature passed a law i-equiring the registration of all plumbers in New York and Brooklyn, and giving the municipal board of health the power to make such rules as it might think proper for the regulation of the j^lumbing and drainage in all buildings to be erected subsequent to the first day of October of that year. Plans must be submitted to the Board for ajoproval, and powers were given it to compel compliance with the rules and regula- tions by making the violation of them a misdemeanor. These rules _ embody the very best and latest practice in such matters, and their enforce- ment has already greatly improved the sanitary condition of the city. LiSiDectors are employed to examine periodically each building in course of erection, and to report any \'iolation of the plans submitted to and approved by the Board. From October 1, 1881, to October IG, 1883, plans for 4,489 buildings have been submitted. These figures will not, of course, agree with the records of the Building Department, as they represent only those houses that contain plumbing, and therefore come under the jurisdiction of the Board of Health. Of these 4,489 buildings 2,808 were tenement-houses, with accommodationfor 133,473 persons. The beneficial effects of the " plumbing law " cannot be accui-ately measured till the lapse of several years has made the collection of statistics possible ; INTEODUCTIOlSr. 399 but the providing of over a quarter of a million of people witli healthy homes has undoubtedly already improved the condition of the city, a result that will be more and more apparent, as the years pass, in the gradual lowering of its death-rate. Following the lead of New York, several other cities have adopted similar plumbing laws, the enforcement of which is, in every instance, accompanied with the like good results. In 1880 the Health Commissioners of Chicago were authorized to in- spect the factories of that city, and since that time great improvement has been made in their management and condition, by preventing injiu'ies to employes from moving machinery ; by the removal of injurious dust and vapors ; by providing- proper ventilation for workrooms, and means of escape in case of fire ; and by improving the condition of the plumbing and drainage. The above sketch will, it is hoped, give the reader some idea of the work that has been done, and is still being done, in this country in the department of preventive medicine. The success that has attended the labors of State and local boards of health and of volunteer associations, especially within the x^ast few years, shows a constantly increasing knowl- edge of sanitary matters among the people generally, which every physician and scientific man should strive to direct in proper channels by all the means in his power. There are, it is true, some few individuals who, by wild and unwarranted statements of the dangers to health from various causes, attempt to make capital by the excitement they create. These, however, together with those who still ridicule sanitary reform as a new- fangled notion, must surely give way before the honest and legitimate labor of trained scientists. It must be admitted that the hoiizon is stUl dark in most of the States ; but with the tremendous strides made by the nation in other directions, the time cannot be far distant when Sanitary Science shall be given its proper place throughout the length and breadth of the land. In conclusion, the editor wishes to express his obligations to those who have been associated with him in the preparation of this Supplement for the articles they have contributed, and on which articles the work is depen- dent for its value. F. N. 0. WATER. By EL^TTN WALLEE, PH.D., Chemist to the Health Department of New York City. Necessity for Water. — It is impossible to over-estimate the sanitary im- portance of water for the welfare and comfoi-t of man. For the preservsr tion of a proper degree of cleanUness of our persons, our clothes, our dwellings, or the articles with which we have to come in contact, it is indispensable. As regards our food, it must be remarked that about 73 per cent, of the human body consists of water, and the food proper to nouiish one should contain about 81.5 per cent, of water. ^Yhat is termed •' solid food " con- tains, roughly speaking, from 50 to 80 per cent, of water, and thus to make up the necessary amount of water, some must be drunk as water, or in some beverage of which water is the chief constituent. A healthy man weighing 11 stone (154 lb) requires every twenty-four hours about 5|- pints of water in some form or other. "When the amount of water in the system is diminished by about one per cent, of the whole, the sensation of thirst is felt, which we usually allay by imbibing the needful amount. ' In brief, water is a prime necessity for human beings, both externally for cleanliness, and internally as food. Sources of Water. — The water which we requii-e in our daily hfe and avocations, comes to us more or less directly from the clouds, as rain or snow. The rain water may be collected directly as it falls, or it may soak into the earth and flow forth again as springs, forming eventually ponds, streams, or rivers, or it may penetrate deeper and reqmre us to dig wells in which it may collect. Our sources of supply may therefore be classified as Kain water. Sur- face water (including sjOTUgs, ponds, streams, rivers), and Well w^aters. From none of these sources, however, can we obtain water which is chemically pure {i. e., nothing other than the compound of oxygen and hydrogen" known under that name), because water is the gi-eat solvent in nature and dissolves some of eveiy substance, gaseous or solid, with which it may come in contact. Many of these substances are beneficial, most of them are harmless, while some are not only hurtful, but may even be deadly. Term " Impurity." — In speaking of those substances dissolved by natm-al water many persons, no doubt following the lead of chemists, call them all •' impurities," which is correct in the sense that they are not water ; while sanitarians frequently use the term impurities to designate only those sub- > Church, Plain Words about Water. Pamplilet, London, 1877. WATER. 401 stances in natural waters "wliich are dangerous or inimical to health. Con- fusion often results from the use of the term impurity in these two different senses, and some bridge the difficulty by calling the hurtful impurities " contamination " or " pollution." Kinds of Impurity. — Using the term "impurity "in its widest sense, the different kinds of impurity which may be met with in water are Gase- ous, Mineral, and Organic (Vegetable and Animal). The mineral and organic impurities may be dissolved in the water, or partly dissolved and pai-tly suspended (still in solid form). The particles suspended may be in so finely divided a condition as to elude the eye, and the water appear clear and bright. Gases. — The gases constituting the air itseK — oxygen, nitrogen, and carbonic acid — as well as those resulting from electrical disturbances of the atmosphere, as ammonia and nitric acid, are all dissolved to some extent by water. Li addition, some springs and bodies of water may contain sul- phuretted hydrogen, either from the decomposition of the constituents of the rocks through which the water percolates, or the action of organic matter upon the sulphates in the water, or other gases may be present, re- sulting from conditions peculiar to the locality (the vicinity of volcanoes, etc.). Moreover, in the vicinity of towns and manufactories, the air may contain various gases resulting from the presence of numerous human beings, from the combustion of coal, or from numerous manufacturing operations, which impurities wiU be imparted to the water. Mineral Matters. — The mineral matters floating in the air are washed from it by the rain. After reaching the earth the rocks and soil with which water may come in contact, yield to it some of their mineral constituents. The salts almost invariably found in terrestrial water are carbonates, sul- phates, chlorides, silicates, and nitrates, of potassa, soda, lime, magnesia, iron, and alumina. Other elements may occur in some localities, and when the amount or the kinds are such as to impart to the water a medicinal value, we may have the so-called mineral springs. The waste waters from manufacturing operations, which find their way into our ponds and water courses, either du'ectly or indirectly by percolation, may also introduce mineral matters into water. Moreover, sewage contains considerable quan- tities of mineral matters which may reach our sources of supply by similar channels. Organic Matters. — The water draining from swamps, from fox'ests, or in short from any places not destitute of vegetation, always contains vegetable matters, more or less decomposed. Moreover, especially in the neighbor- hood of human habitations or industries, the water percolating through the soil usually contains organic matters of animal origin, which, on ac- count of their instability, are passing through the changes known as de- composition. Agents of Decomposition. — The purest atmosphere is full of particles of organic nature which are so small as to defy the powers of the microscope (Tyndall, "On Haze and Dust"); yet many of these particles are the germs or spores of organisms (presumably vegetable in their nature), which are the microscopical or ultra-microscopical agents of decomposition. Organic material from which the mysterious principle we call life has departed, is the congenial soil in which such organisms flourish and reproduce their kind, or such modifications of their kind, that the germs of some of them, when introduced into the human body by the air we breathe or the water we drink, produce disease. The germs from the development of organisms of this class in decom- VOL. II.— 26 402 AMERICAN APPENDIX TO PARKEs' HYGIENE. jDOsing vegetable matter, though not in all cases altogether innocuous, are much less inimical to human life than some of the agents of the decom- IDOsition of animal matters. Of the nature of these germs "we have very httle knowledge — so little, indeed, that doubts have been expressed as to their existence ; but the " germ theory of disease," though but a theory or hj-pothesis, seems to fit the obseiTed facts so completely that it has been very generally accepted. Drink ing-Waler and X'isease.— Disturbances of the digestive organs, manifesting themselves as dian-hoea or dysentery, are believed to have been frequently caused, sometimes by the mechanical action of finely suspended mineral matter, or of hme or magnesia salts in a drinking-water,' more frequently by the presence of considerable amounts of decomposing veg- etable matter. Malarial or remittent fever is also believed to result from this cause.* Typhoid fever and cholera are among the most serious forms of disease which have been in many cases traced to the use of water containing de- composing animal matters (sewage, etc. ), and in some cases it has been thought that certain outbreaks of yellow fever, tyj^hus, diphtheria, and tuberculosis were also attributable to this cause.'' Some investigators, chief among whom is Prof. Pettenkofer, refuse to accept this "drinking-water theory," as it is called, maintaining the so- called " telluric theory," according to which the character of the soil, to- gether with various conditions induced in it by meteorological changes, are the princij^al factors in producing these diseases. * The diseases mentioned have appeared, and have been spread in ways often only explicable by the theory that the imbibition of water, contamin- ated b}- decomposing organic matter (joerhaps infected by the discharges of a patient) have been the direct cause of the disease.^ It cannot, of course, be claimed that contaminated water is the only possible means of spreading these diseases, or that some persons may not have such powers of resistance as to drink the infected water ydih impunity ; some of the advocates of the " telluric theory " are willing to go so far as to admit that the drinking of contaminated water may create a 2Dredisposiiion to such diseases." ' Wolrfhiigel, Wasserversorgung, p. 77. Leipzig, 1882. ''Woods, Chemical Xews, vi. ,30/ ; Smart, National Board of Health Bulletin, i., 317. 3 Nichols, Water Supplj', p. 19. New York, 18»3. * As, regards Typhoid fever, vide Pettenkofer, Zeits. f. Biol., 1870, abstracted also in Report of State Board of Health for Massachusett.*. for January, 1871 (^d Report), p. 112 ; also for January, 1877 (8th Report), p. 117. As regards Cholera, vide Pettenkofer and Decaisne, Les Mondes, xliv. , p. 587, etc. * Cases of remittent fever from foul cistern water, "in the absence of prominent sources of malarial exhalation, to account for the presence of the disease," are men- tioned by Dr. Smart (loc. cit. ). Dr. Woods (loc. cit ) speaks of two ships sailing from Algiers for France at the same time. The one took swamp water, and the crew were afflicted with ague ; the other took upland water, and had no illness of the kind on bo.ird. Occurrences of tvphoid fever under similar conditions are reported by Dr. At- wood and Dr. Vinal. (State Board of Health for Massachusetts, 10th Report (1879), Supplement, pp. 270 and 272.) Several similar cases are quoted by Dr. Chandler (Lec- ture on Water, pp. 36-39. pamphlet, Albany, 1871). and in the 6tli Report of the English Rivers Pollution Commission (pp. 140-184). In some of these cases instances have been known of whole bodies of persons living or working in the infected district (workmen in a factory, etc. ) who did not drink the water and escaped the disease, while some in- dividuals, being quite at a distance, who did drink the water, were attacked (6th Re- port, Appendices, p. 497). The abandonment of the infected water has also prevented the spread of the disease (Millbank Prison, vide 6th Report, -p. 163.) ® J. V. Fodor, Boden und Wasser. Brunswick, 1882. WATER. 403 Sewage may, perhaps, generate Typhoid Fever, etc. — Many cases liave occurred in which typhoid fever at least, and perhaps cholera, have seemed to be generated in decomj)Osing sewage, though this question is at present regarded as an open one/ Sewage may not cause Disease. — It is, however, tmdoubtedly time that water contaminated with sewage may be dxnink without causing any spe- cific disease, but aside fi'om the sentiment of disgust which such a pro- ceeding inspires, it is evidently in the highest degi-ee dangerous. A good water for household purposes should have the following char- acters : The temperatui'e should be at least ten degrees lower than that of the atmosphere, but it should not be much below 45° Fahrenheit. It should be agreeable to the palate, having, perhaps, a slight pungency, from the presence of oxygen or carbonic acid. Characteristics of a Good Water. — Water containing some of the most dangerous forms of decomposing animal matters, may often be very pleas- ant to the taste ; hence it appears that the palate cannot be depended upon in judging of the safety of a drinking-water. It should be fi'ee from odor, even when warmed. Suspended matters should not be present. The sohds remaining on evaporation should not exceed 50 parts per 100,000 (about 30 grains per gallon). Less than two parts of organic mat- ter is regarded as admissible, but the quahty of the organic impurity is much more important than its quantity.^ The hardness should be smaU. The exti-eme limit for its equivalent, carbonate of hme, is set by some as high as 30 parts per 100,000 (about 17^ grains per gallon). The amount of chlorine in chlorides should be small, = 5 parts per 100,000 (3 gi-ains per gallon) is thehmit assigned by some. The amounts of ammonia and nitrates should be quite small, while nitrites should be entirely absent. The properties of the different forms of water available for domestic uses must here be considered. Kain Watee. Amount. — The mean annual rainfall for different portions of the United States may be thus briefly stated.^ Inclies. Northern States (East of the Eocky Mountains) 80 to 50 Southern States 50 to 70 Between the Eocky Mountains and the Pacific Coast Eange 10 to 20 San Francisco 20 to 25 ^ Dr. Jaccond, after critically examining the evidence regarding 105 cases of out- break of typhoid fever (Congres d'Hygiene, 1878, i., p. 377), concluded that in 45 of these cases the evidence was insufficient, in 36 there was evidence that it had been transmitted from patients by the dejecta and excreta, and in the remaining 24 excre- me..*itious matter unmixed with the excreta of persons suffering from the disease, seemed to have generated it de novo. Vide Braithwaite's Retrospect, Part Ixxiv. ; also Brit. Med. Jour., May 27, 1876. - "The Organic and volatile matter," or "loss on ignition," reported by chemists in analyses of water, does not necessarily represent organic matter entirely. (See p. 424.) 3 Taken from Map of Signal Service Papers, No. ix., Lieutenant Dun woody. 404 Proceeding along the Pacific Coast northward from San Francisco, the rainfall becomes heavier, amounting to between 70 and 80 inches at Van- couver Island. Li all cases, as one recedes from the coast the rainfall diminishes. For New England and the Middle States, in calculating for public water supplies, 40 inches is taken as the average.' One inch of rain would amount to nearly 101 (gross) tons per acre,^ or on a house roof of say 20 x 20 ft. area, one inch of rain wovild*be about 250 gallons. With a rainfall of 40 inches per annum this wovild amount to 10,000 gallons, or about 27 gallons per day. The average daily supply 2)er capita in most of our northern cities ranges from 20 to 127 gallons or more.^ Source of Impurities in Rain Water. — The impurities in rain water are derived from the atmosphere through which the rain falls, from the sur- face upon which it is received, the receptacles in which it may be stored, and from the emanations or infiltrations which may reach it when stored. Atmosphere. — Air contains on an average about 0.5 gramme of solid matter per 1,000 cubic metres,^ which is equivalent to a little over 0.2 grain per 1,000 cubic feet. The amount, however, is subject to very wide variations. It is stated ° that " a half-pint of rain water often condenses out of 3,373 cubic feet of air ; and thus in drinking a tumbler of such water, impurities which would only gain access to the lungs in about eight days are swallowed at once." The average composition of seventy-three differ- ent samples of rain water, collected twenty-five miles from London, on a specially prepared surface, etc., may be here quoted as representing approxi- mately the constitution of rain water faUing in an open country, by the time it reaches the earth." Parts per 100,000. Organic carbon 0.099 Organic nitrogen 0.022 Ammonia 0.050 Nitrogen as nitrates and nitrites 0.007 Chlorine 0.63 Hardness 0.62 Total soHds on evaporation 3.95 A set of examinations conducted under similar conditions in this coun- try, might possibly, on account of different climatic conditions, show a greater degree of j)urity in the rain water. The water, however, would not be pure. If zymotic diseases prevail in the neighborhood, it is quite probable that the germs of disease might be thus washed into the drinking-water. At any rate, in the neighborhood of collections of houses, or of manu- factories, or both, the impurities in the rain water from the air would no doubt be very much increased. Surfaces for Collection. — The surfaces upon which rain water is usu- ally collected are, almost without exception, the roofs of our houses. Whatever the material of the roof, the rain falling upon them after a period of fine weather, first washes from them more or less of the dust, excremen- ' J. T. Fanning, Water Supply, Engineering, pp. 46 and 98. New York, 1878. 2 A. H. Church, Plain Words about Water. London, 1877. ^Fanning, loc. cit., p. 39. ^Rernsen, Report of National Board of Health, p. 73, 1879. ^ (ith Report Rivers Poll. Comm., p. 30. «Loc. cit., pp. 27 to 29. WATEE. 405 tal or other, minute plants, spores, and germs, etc., which may have lodged upon them. Cases have also been known where ignorant or lazy servants have emptied slops from the upper windows of a house on projecting roofs below. To avoid the introduction into the cistern of such material as may be washed from roofs by the first portions of a rainfall, " cut offs " have been invented, some of them automatic, by which the first portions of the rain are run to waste, and only the purer after-faU is turned into the cistern. They appear, however, to be but httle used.' Material of Roof Surface. — 'The material of the roof surface has a con- siderable influence on the character and quality of the water. From painted roofs it takes up some of the constituents of the paint, from galvan- ized roo^s some of the zinc, and so on. From shingled or tiled roofs the rain may wash the small mosses and small plants which may have germinated upon them ; from shingled roofs may also be washed particles of the wood disintegrated by weathering, which are transferred to the cistern to decay there. The best material for a roof on which the rain water is to be col- lected is slate, which is sufiiciently smooth to afford comparatively little opportunity for the lodgment of dust, vegetable growths, etc. Cisterns: Wood. — The material of the cistern also requires considera- tion. Wood cisterns are very prone to decay, the inevitable alternate wet- ting and exposure to air to which the sides of the cistern are subjected by the fluctuations of the water-Hne being especially favorable to such decay, the result being the introduction of considerable quantities of dissolved and suspended matters into the water. Lead Linings. — Lead hnings are more readily attacked by rain water than by any other, and should never be used for cisterns. The solution of lead is aided by dissolved air, by nitrates and by chlorides in water, while it is obstructed, and often prevented by the presence of sulphates, phos- phates, and lime salts, ^ The presence of more than three volumes of car- bonic acid per 100 volumes of water, is also stated to prevent the action of water upon lead.^ Cistern water contains less of the protecting sub- stances, and more of those aiding the solution of lead than any other. Cement Linings. — Cement hnings, containing as they do more or less lime, are apt to render the water hard, and on that account are objection- able. They are also Hable to crack and allow of leakage from the cistern, or worse stiU, the leakage of sewage matters into the cistern. Slate Linings. — Slate linings are not open to the objections raised against the others, except that attention to the composition of the cement by means of which the slabs are joined is requisite. Lead oxides are often used in these cements, with the result of contaminating the water with lead.' Location of Cisterns. — If placed above ground, cisterns should be shel- tered from the sun, both in order to keep the water sufficiently cool to be palatable, and to retard or partially prevent any decompositions of ma- terial which may gain access to them. If below the surface, especial care has to be used to prevent the infiltration of various slops, etc., which may be thrown or fall upon the ground near the house. Contamination in this manner is very frequent with underground cisterns, either from the por- osity of the material with which it is lined, or the occurrence of cracks in ' Dr. Smart, loc. cit. ^W. S. Saunders, Cliem. News, xlv., p. 7. ^Eeport of English Commission of 1851. Graliam, Miller, and Hofman, quoted in 6tli Report, loc. cit. , p. 224. •* Phipson, Chem. News, xl., 1. 406 AMERICAN APPENDIX TO PARKES HYGIENE. the cistern. One of the samples of cistern water examined by the English Rivers Pollution Commission,' was found by them "to consist of sewage of even greater strength than average London sewage " fi-om this cause. Sewer-gas m Cisterns. — Another source of dangerous impmity in cistern water is sometimes the ai-rangement adopted of having the ovei-How pipe of the cistern in communication with the soil pipe of the house, by which the noxious gases from the house sewage gain access to the water and are ab- sorbed by it. Other Impurities. — Cisterns are often the resorts of the rats, mice, cock- roaches, and other small vermin about a house, and the excreta or dead bodies of such vermin are frequently fovmd in those receptacles. Their possible presence adds still another danger to the safety of the water. A few of the numerous analyses of stored rain water may be here quoted. A few of them have been selected as showing how impure a cistern water may become. Analyses of Cisteen Water. Results eocpressed in Parts per 100,000. -S Sd ^ .i o.S c a d Location. J o § 6 la c8 'iH IB Analyst. e < <^ w Podehole 5.28 12.00 0.00 0.130 .... 3.8 5.0 0.9 1.6 Eiv. Poll. Comm. Sheffield Barracks. (( i( a Greaselv . , 126.60 5.28 0.730 0.013 6.008 55.70 11.5 0.32 i( (( (( Boston, Mass W. E. Nichols. Newijort, E. I 7.50 0.0105 0.0275 '3.73 0.76 E. Waller. Omaha, Xeb 6.70 0.012 0.0136 4.03 trace (( Cincinnati, 2.68 0.004 0.123 0.55 C. H. Stuntz. (t (( 4.48 0.027 0.118 1.97 <( >( Wilmington, N. C. . 5.05 0.002 0.015 .... 0.70 C. W. Dabney. <( <( 6.90 0.016 0.008 0,52 << K Dr. Smart describes the cisterns so largely used in New Orleans in a report to the National Board of Health.^ They are usually constructed of cypress wood, the avei-age capacity being about 2,000 gallons. "Many are in imventilated enclosures, rank with the emanations of unclean privies. "The rain water shed from the house roof carries with it into the cis- tern the soot and condensed ammoniacal vapors of coal combustion, the in- finity of debris, organic and inorganic, which constitute the dust of a lai-ge city, together with more massive fragments, as of dead insects and decaying leaves, etc. After a few days these various matters settle, forming a soft, black pultaceous sediment, and leading the supernatant hquid comparatively clean and pure," etc. The average rate of accumulation of sediment is about one inch per annum. An analysis of the au'-dried mud from one of these cisterns showed — Per cent. Moisture 17.2 Organic and volatile 34.0 IMineral matter 48.8 ' Sixth Report, p. 29. Greasely cistern water in the tahle appended. » National Board of Health Bulletin, i., 317. WATER. 407 On account of the numerous sources of danger to the purity of stored rain water, most authorities unite in condemning it for general household purposes, though for laundry purposes alone it is usually the best water. In Holland, where rain water is collected among the sand dunes at some distance from the cities, and from those receptacles is conducted to the cen- tres of population, as Amsterdam, rain water is regarded as the best form of water obtainable. ' The conclusions of the Rivers Pollution Commission ^ regarding rain water ai^e as follows : " 1. Of the various kinds of water used for dietetic and domestic pur- poses, 7'ain ivater, when collected at a distance from towns upon specially cleansed surfaces, and -kept in clean receptacles, contains the smallest pro- portion of total sohd impmity ; but the organic contamination, even of such specially collected water, somewhat exceeds that of water from springs and wells. " 2. Eain water collected from the roofs of houses, and stored in under- gTound tanks, is much more impure ; it is often polluted to a dangerous extent by excrementitious matters, and is rarely of sufficient good quahty to be employed for dietetic pui'poses with safety." Snoiv. — Snow is quite as impure as rain, perhaps in many cases more so. Tissandier obtained the following results with snow after it had been melted : Solids per 100,000 parts. Falling in a court in Paris 21.2 Falling on towers of Notre Dame 3 1.8 Falling in the open country 10.4 About 60 per cent, of these soKds was mineral matter. Besides various mineral salts the snow also contained ammonium nitrate.' The amount of ammonia, and hence probably the amount of organic impurities in snow, has been found to vary with the temperature at which it falls, and the nature of the surface on which it falls. * Many hold the opinion that snow water is unwholesome. Dr. Chas. Brewer, U. S. A., speaks of the Western moimtaineers attributing to the use of snow water the origin of the so-called mountain fever. ^ Surface Water. — Springs. Spring water usually comes to the surface after having undergone a filtration through a mass of soil and rock, compared with which the filter beds used by water companies or corporations in purifying the water sup- phed to consumers are insignificant. The amount yielded by them is naturally more dependent upon the rainfall of the district than upon the nature of the geological formation. The quaUty is, however, dependent upon the geological character of the rocks through which the water has passed. All of the mineral constituents ' Congres d'Hygiene, 1878, ii., p. 100. 2 Sixth Report, p. 424. ^ Comptes Rendus, January, 1875. ■^Vogel, Akad. d. Wissenschaften Miinschen, part I., 1872. Boussingault found in freshly fallen snow 0.178 part of ammonia (per 100,000). After the same snow had lain on a garden soil for a day and a half, it contained 1.034 part (WolfEhugel, Was- serversorgung, p. 9). ^ Vid. Smart Buck's Hygiene, ii., pp. 129 to 134. 408 AMERICAN APPENDIX TO PAKKES HYGIENE. of those rocks are taken up by the water to some extent. In general terms, the older non-calcareous rocks — granite, sandstones, etc. — aftbrd the water freest from mineral matters, while calcareous formations usually give up the most mineral matter to the water. A water is considei'ed usable in respect to mineral matter if it does not contain over 30 grains of solids per gaUon (50 parts per 100,000), Calcar- eous strata also not only give up more mineral matters to water, but also, among other elements, the water takes up considerable quantities of hme and magnesia, Avliich cause the "hardness" so objectionable in water, especially for washing and cooking. Character of Water-bearing Strata. — The character of the material through which the water may percolate is of some importance. Rocks containing many fissiu'es often yield water of doubtful quahty. The water from gi-avelly deposits also is variable in quality, no doubt in both cases the result of imperfect filtration. Avoid External Contamination. — The above is apphcable to the water from springs where there is no opportunity for contamination by drainage fi'om heavily manured fields, or perhaps houses and barnyards. If, for instance, a spring issues near the base of a hill on which are located farm- houses with their accompanying outhouses, as well as cesspools, barn- yards, pigstyes, and the like, the probabilities of the contamination of such a spring are very great. In such cases, howevei', the dip of the strata by which the water is to some extent guided, might become a factor in de- termining the chances for or against the desirability of the water for do- mestic uses. The external configuration of the land is not' always a guide as to the j^robable lay of the strata beneath. Constanci/ of Flow. — Aside from the question of the probable ability of a spring to always meet the demand which may be made upon it, the con- stancy of flow in a spring is usually a valuable indication. Springs of vai'iable volume generally draw their supply fi-om a near and limited area, and the water from them is more likely to be contaminated than that from those yielding a more constant supply, and presumably drawing from a larger and more thoroughly filtered source. Composition of Spring Waters from Different Formations. Results given in Parts per 100,000. Formation. Granite and Gneiss Rocks Silurian Rocks Devonian Rocks and old ) Red Sandstone ) Yoredale and Millstone ) Grits and Coal Measures j Lias OoUtes Chalk Flu\'io-Marine, Drift, and ) Gravel ) 25.06 .2 « "a ? OfC 0.042 0.008 0.001 0.0510.0140.001 0.054 21.9l'0.050 36, 30. 29 410.073 33 0.043 840.Q44 61.32.0.086 0.0120.001 0.014 0.001 !^S 0.106 0.178 0.764 0.393 0.467 0.0190.001 0.011:0.0010.402 0.010 0.0010.382 0.019 0.0010.354 1.69 1.84 1.85 2.48 1.55 2.45 2.76 3.0 6.8 3.85 12.0 13.1 30.1 24.4 23.6 s a 15 22 22 7 35 30 37.6 10 TTATEE. 409 Contents. — Organic matter is usually present to some small extent, but if pollution by excrementitious matters is prevented or excluded, it is usually harmless. The preceding is a portion of the table giving the average composition of rmpoUuted waters examined by the Enghsh Eivers Pollution Commis- sion. ' Summary. — Spring water, when siu'face pollution is avoided, is re- garded as the best possible kind of water for general domestic uses. "When the water reaches its outlet through a very permeable stratum (gravel or fis- sured rocks), it may not be sufficiently filtered to have the desii-able quali- ties common to spiing waters as a class. In hmestone regions it may also be too hard for comfort or economy in the household. SUEFACE WaTEE. PoXDS A>1) STEEAilS. Amount — It is estimated that about half of the water descending upon the earth as rain, finds its way into the streams.' Impurities : Mineral. — The character and amoimt of the mineral impu- rities in ponds and streams, is to some extent dependent upon the charac- ter and amount of those constituents in the springs which supj^ly them, and upon the geological formation where they may be. The amount, how- ever, is usually smaller, partly because these sources receive some of their water du-ectly fi-om the rain that either falls dii-ectly upon their surfaces or runs into them during a rainfall, without passing through the ground, and partly because the plants gi'owing in them abstract some of the min- eral matters for theii' own sustenance and gi'owth. Organic. — On the other hand, the water in ponds and streams is ex- posed to influences tending to increase the amounts of organic matter. The plants growing in the water or along its margins afford some of this ; the dust and leaves borne by the vdnd contribute to it, and in the vicinity of human habitations and manufactories, the sewage and manufactui'ing re- fuse work their way into them, imperfectly filtered by the adjacent soil, or are turned into them directly without any such pai'tial filtration. "Watercoui'ses are the natural drains of a country, and hence the ap- pearance of such material in the streams and rivers is inevitable. Conse- quently the quality of the water of streams is better, as a rule, the neai'er we approach to the source. Suspended Impurities. — Besides dissolved impurities, sui'face waters naturally contain various matters in suspension, which vary in quantity and character with the weather, and in each individual case with the topogi-aphy- of the country, the chai'acter of the rocks and soil of the water shed, the presence of toT\-ns, manufactories, etc. As a sample of the same river at different times and different places, \di\\ regard to its contents in suspended matters, the following results of obseiwations on the Ehine may be of in- terest : 1 6tli Eeport, p. 131. ^ Fanning, loc. cit. , p. 77. 410 AMERICAN APPENDIX TO PARKES HYGIENE. Suspended Matter. ' (Parts per 100,000.) At Strasbui'g, July and August . , . At Bonn At Bonn At Bonn, after dry Aveather At Uerdingen, after sudden floods In Holland By Weight. By Volume. 2.00 ' 6.25 20.50 1.73 78.00 1000.00 A table of analyses of some of the river waters in the United States is here given. The increase of material of vai'ious kinds in some of these rivers, as we descend the stream, is noticeable. Rivers in the United States. (Eesults in parts per 100,000.) Mississippi Minneapolis, Minn. Mississippi St. Louis, Mo. Mississippi '^ . . . i St. Louis, Mo. Ohio j Cincinnati, O. Louisville, Ky. Evansville, 111. Indianapolis, Ind. Nashville, Tenn. Wilmington, N. C. Albany. N. Y. Poughkeepsie, N.Y, Poughkeepsie, N.Y. New York, N. Y. Philadelphia, Pa. FaUs, N. J. BeUeville, N. J. Ohio. Ohio White Cumberland. Cape Fear. .. Hudson Hudson Hudson s Croton Schuylkill... Passaic Passaic Date. Is 2 2 "2 « o 1877 Aug., '73 Aug., '73 "isso" 1880 1880 Sept., '76 Aug., '81 March, '72 Nov., '77 Nov., "77 '72 to '82 July. '81 July, '72 July, '72 240.1 45.04 4.2 2.1 '9.30 10.40 1.2 ■ 1.7 5.702 1.678 5.28 7.36 2.58 1.95 18.6 1. 244.3 1. 47.14 ., 14.2 11.7 0. 18.6 0, 28.0 0, 13.80,0. 5.6 10.5 0, 12.1 . 10.1 I. 7.380 12.01 7.86 9.31 I 0.003 0.002 0.011 0.048 [trace 0.012 0003 0.000 0.0035 'O.OOS 0.016 .sg 0.015 0.068 Analyst. ... 0.0109 0.0197 ... !0. 0109 0.0184 3 0.001 ,0.012 56 '0.002 ;0.012 4.32 0.040 0.040 470,0.049 ,0.085 11.47 8.22 7.86 6.00 3.21 8.6 S. F. Peck^am. D. V. Dean. D. V. Dean. C. H. Stuntz. T. C. Van Nuys. T. C. Van Nuys. T. C. Van Nuys. N. T. Lupton. W. R. Nichols. C. F. Chandler. W. K. Nichols. W. R. Nichols. E. Waller. n. Leffmann. H. Wurtz. H. Wurtz. Examinations of Water from Lakes and Ponds. (Results given in parts per 100,000.) Place. Analyst. Date. Org. and Vol. Mineral. Total Solids. Hard- ness. Lake Michigan Chicago, 111 Blaney . . 1859 1.81 9.63 11.44 Lake Erie Cleveland, O Cassels. . Feb., 1866 1.10 8.23 9.33 3.66 Lake Ontario Toronto, Can Croft ... Feb., 1878 0.77 11.73 13.50 .... Lower Chain Lakes. Halifax, N. S Lawson .Sept., 1878 3.83 3.49 7.32 Lake Massabesic. . Manchester, N. H . . Hayes. . . June, 1869 2.77 1.93 4.70 6.84 South Pond Plvmouth, Mass Nichols . June, 1877 1.40 1.60 3.00 VVatuppa Pond Fall River, Mass.. . Appleton 1870 1.43 1.67 3.10 6.34 Lake Konomoc .... New London, Conn. Nichols . Dec, 1879 1.20 1.60 2.80 Artificial Lake Norwich, Conn Silliman. Jan., 1873 1.16 2.0 3.16 6.93 Lake Ovvasco Auburn, N. Y Chandler 1876 1.20 15.80 17.00 8.7 Green Lake Syracuse, N. Y (^handler Jan., 1871 1.20 14.14 16.34 Reeds Lake Grand River, Mich . Kedzie . . , Aug. , 1 872 Much. 12.86 Blae Lakes San Francisco, Cal. Falkenau April, 1875 21.0 ' Vid. Nicliols, Water Supply, Table vii., p. 57. 2 Filtered. WATER. 411 The " places " mentioned are those for which the water was either pro- posed or used as a source of public supply. In a few cases the lake or pond is a considerable distance off, e.g., the "Blue Lakes, San Francisco, Cal.," are high up on the Sierra Nevada, 8,000 feet above the level of the city. Purification of Rivers by Floxo. — The question of the self-purification of rivers by their flow has been earnestly discussed, and cannot be regarded as settled at the present time. Such pTu-ification would take place by the oxidation of the dangerous organic material, by deposition of the suspended material, carrying with it some of the organic impurities, or by the agency of organisms in the water, as fish, water plants, or the more minute algce, some forms of which^ possibly feed upon or destroy the as yet unrecog- nized " somethings " which cause disease. Dilution of the water in its progress causes an apparent and perhaps a real purification. The results of series of exj)eriments made by the English Elvers Pollu- tion Commission ' would go to show that oxidation alone is insufficient to purify the water of a stream in which the water has been once fouled by sewage. Dr. Tidy ^ claims that the rapidity of oxidation depends on, a, the de- gree of dilution of the sewage ; h, the distance of the inin ; c, the rapidity of the current ; d, the temperature, and e, on certain natural or physical conditions : e.g., if the bed is rough, so that the water has a greater op- portunity for aeration, or there are numerous locks, weirs, etc., along it, which may produce the same effect, the j)urification is more rapidly effected than where the stream flows quietly along. By arranging the experiment in a different manner to that of' the Elvers Pollution Commission, he ob- tained results which he interpreted as indicating that the organic impuri- ties in a river would be materially reduced by oxidation in a flow of a few miles. He adduces statistics to show that the death-rate in towns sup- plied by river waters is less than in those supplied from deep wells, and also asserts that there is no case of water of a river, after receiving sewage, having caused an outbreak of disease after a flow of ten or twelve miles. ^ The subsidence of mineral matter, carrying with it some organic impuri- ties, and the influence of fish, etc., he regards as aids to such purification. The influence of water plants and organisms as agents of purification is also dwelt upon by others." Many of these authorities also mention that plants, etc., remove chlorides and other mineral constituents from the water. W. E. Nichols ^ suggests that " the apparent self -purification of rivers is largely due to dilution, and the fact that a river seems to have purified itself at a certain distance below a point where it was certainly polluted, is no guarantee that the water is fit for domestic use." In this connection it must not be forgotten that rivers usually receive large additions to their volume by subterranean infiltration, which is none the less real because out of sight. • Sixth Kept., pp. 134-140. ^ Journal of Lond. Chem. See, xsxvii., 268. 2 An outbreak of typhoid fever in a hospital using river water, where the disease was traced to a barracks tioenty-five miles up the stream, is quoted in Mass. State Board of Health Eeport, 1876, p. 284. < R. Warington, Chem. News, xli., 265 ; E. J. Mills, ib , xli., 260. The discussion between Drs. Frankland and Tidy on this subject may be found in Jour. Lond. Chem. Soc , xxxvii., 268 ; also Chemical News, xli., 245, and xlii., 113. ^ Water Supply, p. 69. New York, 1883. 412 AMERICAN APPENDIX TO PARKEs' HYGIENE. Dilution of a contaminated river may render it difficult or impossible to decide, by chemical analysis, that pollution exists, but we cannot rest satisfied that dangerous contamination does not exist in it on that accoimt. Summary. — In conclusion it must be said, -uith regard to ponds and streams as sources of water supply, that where contaminating influences of cultivated land, manufactures, and house drains, etc., are absent, they are good sources of supply, though perhaj)s at times charged with sus- pended matter, which should be removed by subsidence or filtration, or both. Ponds and lakes M'here the water is stagnant should be regarded as suspicious or dangerous, but where the water in them changes fre- quently they are safe. Rivers and streams are always better (as regards safety for health) nearer their sources. After having once received sewage they may perhaps be safe if they have flowed for some distance, but the use of water fx-om such streams is not advisable if any better supply can be obtained. Wells. Amount. — It is estimated that about one-fourth of the rainfall of a dis- trict penetrates into the ground, and may be obtained by shiking wells. ' As with springs, a variable supj^l}' shows a near source. Kinds of Wells. — The ordinary forms of open wells have been roughly classified into shallow and deep wells, according as they are less or more than about fifty feet in depth. We may have also diive wells, ^ made by driving a pointed ii'on tube down into the gx*ound to any desii-ed depth, and (what ai'e infrequently used for household supplies) artesian wells made by boring. Impurities : j\[ineral. — With regard to any or all of them it may be said that the mineral impurities are usually larger than in the case of pond and river waters, varying very much (as in the case of springs) with the geologi- cal formations which the water may have traversed ; usually the deeper the well the more mineral matter it contains. Organic. — Almost all of them contain some organic matter. The or- ganic matter of a dangerous character comes from sources at the surface, house drains, manufactures, etc., and if a well penetrates below the influ- ence of such impui-ities, and infiltration of such surface waters are ex- cluded, water of good (sanitary) quality may be obtained. There is a ^\-idespread belief that water becomes purified by filtration through the soil. This is true, but not to the extent generally supposed. The purifying power of the soil is much more limited than is usually imag- ined, and the amount of material to be destroyed, as well as the time nec- essary for its destruction, are factors in the question which are usually lost sight of. A soil becomes very rapidly saturated with material of a danger- ous character to have in o\u' drinking-water,^ and the unlimited purifying power with which it is generally credited is, in fact, very limited after all, unless opportunity is affoi'ded for the operation of what might be termed the regenerative forces of nature. Distance to lohich Contamination may reach. — Cases occur almost every day where householders wiU triumphantly state that theu- wells are a cer- ' Fanning, Water Supply, Engineering, p. 102. - Called in England •' Abyssinian Tveils," because used by the British army in the Abyssinian campaign. " For experiments on this point, vid. v. Fodor, Boden und Wasser. Brunswick, 1883. WATER. 413 tain number of feet (usually less than t-^enty) from any cesspool or drain, and that therefore they cannot conceive of any possible dan 9 P4 j • CO • o \ j r-( 1 a 9 A j G 3 ZG • •* d • rH a, to 2 a *. ; o • d • j • 1 tf ' O 02 ' " a, ei —5 tH •g o CO CO S J ^ ? CO (D 3 • • '^ CI CO » C5 o o ^ 1 3 1 > \ 1 CO CO CO CO CO iH rH ee . — — § • : '^ CO o CO • • ' i* ^1 i . . o o . , ^ • • o o d d • • -^ "S . . . . cC" .52 cs 2 ai O • • e o O O q e CO 2 tp CO ■ * (M C« CO U ^ O > ^ «=. «o (M CO o 00 E^ , P- ^ (M Gsi O d t^ S« S CO CO »— 1 o r® H '§ '^* CO • . V 'S (M '« ; o • * C 1—1 • . S -a ** iH ^ : o ; \ c o d * * • d o CO , , ^ CO , , 'o • • c T-H • • • g M GO 1 -S ^. 1^ ?S CO • • c q • • CO 1 p • * c d • * " d o iz; cq 1 O CO ■^ H _^ '<*< o 1— t r^ ^'^* • 'a '3 "^ t- o o o o o 1 6) ^ w ^' co* o o d a d 1 « 5? DO t^ tH CO 1 • CO o o .^ , PN *• e; CO* • 00 d o d o d ; a * CO co" .1 p: -S • a , s • • • • • g • • e3 • '^ Ol r^ 09 1 1 1 a C3 o» g -g •■§ d a § 1 o '2 O -£ 1 c3 O o a eg . -S H ^ ^ 1 < ® 6 o % CC O 'a .a 1=1 .a § o J5 • l-l o I 1 'o .a a O OD 05 (1) 1 C3 o tr. 1 3 o WATEE. 433 E:51FEKENCES AND NoTES TO PrEOEDING TaBLE. Wos. 1 and 2, Oermantoicn, Pa. — Prom the same well. Taken nine days apart, dur- ing the prevalence of the epidemic. The "total solids " recorded under No. 1, was from still another sample. A child living some distance from the place drank some of the water and sickened in consequence, otherwise the cases were among those living in the neighborhood and using the water. Well, ten feet from a brick sewer, which was somewhat choked at that point. — Chemical News, xliii., 188. No. 3, Fairhaven, Mass. — First case, September 30th; second case, October 3d; third case, October 6th ; fourth and fifth cases, October 7th ; sixth case, October 8th; seventh case, October 9th ; eighth, mild case, middle of October. The entire family. No others took the disease except the nurse and her mother who nursed her. Neither of them drank any cf the water. Well, one hundred feet from privy vault. Connection between the two proved by throwing salt into the privy vault and finding an increase iii the chlorides in the well a few days later. — "Massachusetts State Board of Health Report for 1879," Supp., p. 270. No. 4, Sciiuate, Mass. — Examination made about a month after the disease pre- vailed in the family and among neighbors who drank the water. None of the cases fatal. Only three other cases (a mile away) in the town previous to the outbreak at this spot. Well, thirty feet from privy. Water contained bacteria and infusoria. — " Massachusetts State Board of Health Report for 1879," Supp., p. 273. iVb. 5, Grouville, Island of Jei'sey. — Female Orphans' Home. House isolated. Well, sixty feet from an old cesspool used only for urine and soapsuds at the time of the out- break. Disease apparently generated de novo. No new cases occurred after the pump was removed. — Chemical Neics, xl., 97, No. 6, Eagley, near Bolton, England. — Brook received the excreta of operatives at a factory, among which one man had typhoid fever. Water said to have been used only to wash the milk cans. No one affected except those who drank the milk from this dairy. — " Massachusetts State Board of Health Report for 1877," p. 123. No. 7, NeiD York, Manhattan Island — Asyh/.m, — Well over one hundred feet deep. No ostensible cause for the appearance of the disease, except communication through the drinking-water. Sewage appeared to reach the well in about two hours from the time of deposition in the sewer. Connection between sewer and well proved by appli- cation of the " lithia test." No. 8, Broad St., St. James Parish, London, England, 1854. — The number of cases is unknown ; 609 deaths are believed to have resulted directly or indirectly from drinking the water of this well. Of two factories situated side by side, the workmen in one drank the water and were almost all attacked, while in the other, other water was drunk and the workmen escaped. An old lady, living entirely outside of the affected district, drank the water, as did also her niece living with her, and both died of the disease. No one else in their immediate neighborhood was attacked. The well was closed up at the time, but opened a year after the outbreak and pumped out, after which this sample was taken. — •' Sixth Report Rivers Pollution Commission," p. 497. No. 9, New Orleans, La. — Odor of the water, like swamp water. Cistern (wooden), old and rotten. — "Report on the Water Supply of New Orleans and Mobile. Dr. Chas. Smart. National Board of Health Bulletin," vol. 1., 317. No. 10, Mobile, Ala. — Case similar to the last. With regard to this, Dr. Smart notes particularly that the fever "prevailed in the absence of prominent sources of malarial exhalation to account for the presence of the disease." — " National Board of Health Bulletin," i., 317. No. 11, Rye Beach, Mass. — Digestive disturbance caused, "characterized by a sen- sation of giddiness and nausea, vomiting, diarrhoea, severe abdominal pain, all of which was accompanied by fever, loss of appetite, continued indigestion, and mental depression." Ice taken from a shallow pond choked with marsh mud and decomi^os- ing sawdust, and used in the hotel where all the cases occurred. — "Massachusetts State Board of Health Report for 1876," p. 467. Vol. II 28 434 AMERICAN APPENDIX TO PARKEs' HYGIENE. Testing Connection of Well and Cesspool, etc. — Wells in the neighborhood of houses are especially liable to contamination from the cesspool, drain or privy vault. The most convenient mode of testing whether any connection exists between the well and such possible sources of contamination, is by adding to the cesspool or privy vault some soluble compound, and testing for its presence in the well. Sometimes largtJ quantities of salt are thro^\•n in, and the weU water is then tested for an increase in the proportion of chlorides. ' This method may be affected by temporary or local conditions, and is, on that account, inferior to the more expensive method of throwing soluble lithium salts into the cesspool, sewer, etc., and testing the water afterward for the presence of Uthia. ExcejDt in the water of mineral springs, lithia is of rare occurrence ; moreover, very minute traces can be detected by the spectroscope, and though much of the hthia is probably absorbed by the soil, enough wiU usually work its way through if the sus- pected connection exists. Ice. A few words on the impurities in the ice so lavishly used in this country for cooling our beverages in hot weather. Cases of illness have occurred which have been traced to the use of ice in this way, though not very fre- quently. The commonly received impression that water in freezing not only rejects all impurities, but that any germs if frozen into it are neces- sarily killed, requires some correction. Water in freezing wiU enclose par- ticles of organic or other matter which may be suspended in it, and almost any microscopist can testify to the persistent vitality of many of the lower forms of organisms, even after being imprisoned for a long time in blocks of ice, perhaps benumbed and dormant until released, but living. The general rule that " a pond or river which is unfit as a water supply should not be used as a source of ice supply " '" is a good one, but often disre- garded. As regards the chemical analysis of ice, it should contain no perceptible suspended matter when melted, very little dissolved matter, or chlorine, and the albuminoid ammonia should not exceed 0.005 part per 100,000.' Conclusion. In discussing the question of water supply reference has necessarily been made to certain theories which are now engaging the attention of sanitarians, and which (inasmuch as they are theories or hj'potheses) have both strong supporters and A^gorous opponents. Such are : The germ theory of disease ; the " drinking-water theory ; " the purification of rivers by flow ; the generation of diseases de novo ; and finally the value of certain of the chemical tests applied to water. It must be remembered that these theories have been advanced after a careful study of numerous facts, and whether true or not as they are now stated, they cannot be regarded lightly. Future study of sanitary science may modify these views as at present held by their sujjporters, but it will be always desirable to keep on the safe side in selecting a location for our dwellings or deciding upon a water supply for our households, and we should not unnecessarily risk the health or lives of our families. ' Nichols, Water Supply, p. 133. * Ibid., p. 52. ^ itid.^ p. 54. THE CHAEACTEES AND DISTEIBUTION OF AMEEICAN SOILS. By N. L. BEITTON, PH.D. The soil is generally understood to be the upper, superficial portions of the accumulations of loosely consohdated materials, which in most regions form the surface of the earth. In this chapter it will be so considered. It is the part of the earth's crust which, directly or indirectly, sujDports vege- table and animal life, and is thus of immense importance to mankind. The thickness of this superficial material varies greatly in difierent locaHties ; in some we find very little, or, indeed, none at all, the rocks coming di- rectly to the surface ; but such are hmited in area and mostly confined to the slopes and summits of mountains ; nearly everywhere there is an ap- preciable quantity of soil, and the accumulations are occasionally over one hundred feet deep. To render what follows intelligible to all, it has been deemed advisable to preface this dissertation with some of the leading facts relating to the origin, structure, and constituents of soils in general Steuctuee and Composition. The soil is constituted of variously sized fragments of mineral and or- ganic matters, and its character depends on the relative abundance of the different constituents, the dimensions of the fragments, and their greater or lesser consoUdation. It is invariably permeated to some extent by water and air, and the quantity of these fluids depends on the permeability and the absorbing property of the soil, which vary greatly. The size of the component fragments is very variable, and ranges from microscopical par- ticles, which make up the greater part of the mass, to botdders of huge proportions. Mineralogically considered, it consists primarily of sand and clay ; these constituents occur either alone or intermingled with each other in various proportions ; they are often accompanied by pebbles, or even large stones of different kinds of rock, and generally by small amounts of other inorganic or organic matters. Most of the latter is derived from plants and is known as j)eat, humus, etc. Clay and sand are, however, the bases of all soils, and one of these minerals is always present. Oeigin of Soils. AU soils have been derived from previously existing rocks by processes of decay and disintegration acting through immensely long periods of time, and are still forming wherever rock masses are exposed to agents which produce and forward these changes. The materials resulting from 436 AMERICAlSr APPENDIX TO PARKEs' HYGIENE. tliese processes are found either in situ, where the rocks furnishing them ■were formerly situated, or at a distance fi'om the parent rocks, and this commonly manj^ miles. Among the most widely acting and important of the agents which pro- duce decay in rocks are the following : (a) Percolation by Water, and the consequent solution and removal of some ingredients. (b) Frost, which promotes disintegration by the formation of ice from the water contained in rocks, the exjDansion accompanying this phenome- non forcing fragments loose. (c) Oxidation of certain constituents, particularly the comj)ounds of iron in pyrites, hornblendes, etc. (d) Kaolination, by which the feldspars are reduced to clays. (e) Tlie Action of Vegetation, plants having the habit of forcing their rootlets into minute crevices, and by subsequent growth and chemical ac- tion disintegration ensues. (f) Erosion by Water or lee. — The destructive action of rain, cuiTents of water, ocean waves, etc., on rocks is continually in progress. Ice erosion, now confined to the polar regions and to a few elevated mountain chains where glaciers yet occur, was a most important agent of soil production at a former period of the earth's history. These agents of rock-destruction act independently or in conjunction ; there are also other less important ones contributing to produce the same results, which need not here be discussed. The most imj)ortant of the agents which tend to remove and distribute the disintegrated materials resulting from the above-enumerated forces, and to whose action many of our soils owe their origin, are : (a) Water. — The transporting j^ower of water is well knowTi. The pro- ducts of rock-decay become washed into streams, and the more commin- uted portions, the clays and finer sands, are carried by them into the rivers, and in part deposited along the valleys, forming the rich flood- plains which in many cases extend over hundreds of square miles of terri- tory on each side of the river proper. Deltas have a similar origin. The continued beating of waves against the coasts gradually promotes dis- integration, and much of the sand thus produced is ultimately driven upon the shore to form beaches. (b) Ice. — At jDresent the work of ice in this connection is insignificant. But during the period of past time kno^vn to geologists as the Glacial Epoch, it played a grand part in soil production. During this period a great ice-sheet, many hundreds of feet in thickness, advanced over North America from arctic and sub-arctic regions, extending southwardly to the coast of New England and Long Island, the Narrows of New York Harbor, and thence across the continent, its southern margin following aj^proxi- mately the fortieth parallel of north latitude to the IMissouri River ; thence bending northward it joined ■ndtli another sea of ice, which descended from the Eocky IMountains as far south as the thirty-sixth parallel. Local gla- ciers were also develoj^ed on the Sierra Nevada and along the Pacific coast. This ice-mantle covered all explored parts of North America north of the lines above described, and it has left undeniable proofs of its work on the rocks which it smoothed and striated, in the immense erratic boulders and in the soils which occur within the areas traversed. In its slow south- ward movement it carried an immense amount of debris, torn from the rocky strata over which it passed, and during the ensuing melting this burden was left scattei'ed over the areas occupied by the ice. The melt- CHAEACTEES AND DISTRIBUTION OF AMERICAN SOILS. 437 ing of these enormous ice-sheets was accompanied by a great flow of water, which fui'ther distributed the rocks, clay and sand, and effected a partial sorting of the materials, concentrating fragments of similar.' sizes and same specific gravity. Thus were formed the deposits of fine and coarse gravels, sands, and "boulder-clays" found within the glaciated ai'eas, and a lai-ge part of the soils of these portions of Xoi'th America were deposited in this manner. "Within the area of this " Glacial Drift " all varieties of soil ai'e found, as the manner of their production would lead us to expect, and radically differing kinds are found within a few feet of each other. The drift, or till, as it is sometimes, designated, varies in amount, however, in different districts ; in many localities it is only a sHght covering, and here the de- composition of underlying rock has originated much of the soil. (c) Air. — ^Ye may add atmos]Dheric cuiTents to these tAvo most impor- tant distributing agents. Then- action is appreciable only on very hght, readily movable soils, and is limited in extent and imporiance. Soils Consideeed wtth Eegaed to theie jMixeealogical Compositions. Any attemjDt at classifying our soils under this consideration must at best be but imperfect, as it is difficult to draw the hnes between the divi- sions which have to be adopted. A soil which is placed under one category in ceriain pai'ts of the country, is considered as belonging to another in other sections ; this difficulty is due to their relative abundance in the various districts. It has been thought desii-able, however, to present the following classes, as in some respects the divisions here made are simpler and more apparent than in describing them according to theu' origin, this being often somewhat obscui-e, although fi'om a strictly scientific standpoint the more satisfactory. The three most important and widely spread classes of soil as here limited are as follows : — Sandy Soils, Clayey Soils, and Loams. (a) Sandy Soils. — These are here regarded as consisting of seventy-five per cent, or more of C[uartz sand (silica). They are found throughout the countiy, and ai'e generally healthful and desirable for building sites, as they have a fi-ee and ready natural drainage, and are only to be avoided when low-lring and satui'ated with water or organic matter, or when im- mediately underlain by impervious strata, forming basins in which water is retained. Such a geological stmctiu'e causes permanent saturation of parts of the soil, and is often productive of malarial troubles. It is there- fore advisable to examine the underlying strata. (b) Clayey Soils. — Under this division we here include all soils consist- ing of seventy-five per cent, of clay (alumina silicates) or a higher percent- age. They are widely spread all over the country, and are wet, cold, impervious materials, and hence undesirable, unless the inclination of the strata is sufiicient to afford good surface drainage. Clays are generally to be regarded with suspicion. (c) Loamy Soils. — These vaiw greatly ia composition, being made up of variable amounts of clay and sand, either of these constituents reaching seventy-five per cent., as the class is here limited. Those approaching the extreme limits of this definition are known as Clayey Loams and Sandy Loams, Only the varieties consisting very largely of clay are to be avoided, and, generally speaking, all that has been said about sandy soils is appHca- 438 AMERICAN APPENDIX TO PARKEs' HYGIENE. ble to loams as "welL They are perhaps our most abundant soils, and are nearly eveiywhere common. To these three principal classes of soils the following, less abundant ones, may be added. (d) Stony or Gravelly Soils. — These are local in distribution. Theu' natuTJil drainage is excellent, and they often aftbrd veiy desii-able sites for habitations. (e) Calcareous Soils, are loams or sands somewhat impregnated with car- bonate of lime. The amount of this substance j^resent varies considerably, sometimes, but rarely reaching fifty per cent, and ranging downward to five per cent., under which percentage the soil is not noticeably calcareous. Thev occur only in limestone or marble regions, and are generally found ■whei-ever these rocks approach the sui*face, being the result of their dis- integi-ation. Calcareous soils are distinguished fi-om others by cam-ing "hard " waters, this character being due to the presence of carbonate of hme in solution. This is not necessarily an injurious featui-e, and these soils may be perfectly salubrious. (f) ATagne.iian Soils, result from the decay of sei-pentines, talcose or chlorite schists or other rocks principally composed of magnesian minerals ; thev are penneable, and not to be regarded as objectionable. Their only bad feature Hes in the large quantities of magnesian salts earned by the waters coming from them. These soils are only occasionally met with. (g) Highly Ferruginous Soils. — These overlie deposits of bog-iron ore, and are veiy local Their salubrity has been questioned, and malarial troubles ascribed to their proximity in certain foreign localities. "We have heard of no such experience in this country. (h) Soils of 3Iud or Peat. — These are confined to low gi'ounds and are essentially marsh soils ; they will be more fully discussed under that head- ing. They consist of loams or cLays, saturated -^-ith water and highly im- pregnated with decaying vegetable matter, the latter substance frequently making up one-half of the soil, or even more. True peat api^ears to be non-malarial, but all these wet, mucky soils are probably dangerous in other ways, and it is safer to avoid them. (i) Soils of Humus and Mold, result from abundant vegetable growth in comparatively diy situations, and are the natural soils of forests, where the accumulations are derived fi'om the leaves and twigs ot trees and shi'ubs ; and of jDraii-ies, where they form from grasses and other herbs. These soils are strictly superficial seldom extending more than a foot in depth, while peat may be fifty feet in thickness. Soils Considered with Regard to their Origin. Considered from this point of view, we may diride oui' soils into two quite weh-marked classes, viz. : — Transported Soils and Indigenous SoilSf A. — Transported Soils. We have already briefly alluded to this class in discussing the methods by which soil-foiining materials have been produced and the agencies whereby they have been distributed. These soils have been brought to their present positions from other places, and generally have little in com- mon with the underlying rocks. We will successively discuss the different varieties which fall under this heading. CHABACTERS JlND DISTRIBUTIOTST OF AMERICAN SOILS. 439 (a) Soils of Glacial Drift. — These consist of unassorted deposits of clay, sand, gravel and boulders brought from the north by the ice-sheets of th Glacial Epoch ; and are found throughout the areas traversed by them In some locaUties the deposits show^ signs of stratification, but generally this structure is absent. The surface of the country over which they are found is generally sufficiently diversified by the uneven thickness of the accumulations, and by in-egularities of the strata on which they rest, to af- ford free drainage in some direction, and unless excess of clay renders them impervious, desirable building sites, from a sanitary standpoint, can generally be selected. Unfortunately, however, this latter condition some- times occurs, and the. clay interferes seriously with drainage. This is es- pecially true in certain localities along the southern margin of this drift on the Atlantic sea-board, where the conformation of the surface of the "terminal moraine " is such that swamps and stagnant ponds are numer- ous, the non-porous soil retaining water in hollows often surrounded by much higher ground, although many feet above tide-level. Here relief is only obtained by extensive, and therefore expensive systems of artificial drainage, and must sooner or later be adopted in all thickly populated dis- tricts where such conditions prevail. From what has already been said of the boundaries of the Glacial Drift, its geographical distribution will be apparent. (b) Soils of St7^atified Drift, differ from the Glacial Drift soils in having a well-marked stratified structure, the clay, sand, and gravel composing them being arranged in successive layers, which are usually readily dis- tinguishable from one another. In many districts they occur with the other class of drift soils, and were deposited from the currents of water and the lakes which accompanied the melting of the glaciers ; they occur also in non-glaciated regions. When mostly composed of sand or gravel, these soils are perhaps the most salubrious of all, combining a perfect natu- ral drainage by percolation, with great capacity for retaining heat, and free- dom from organic matter. When principally composed of clay they are to be avoided. Perhaps the most notable of these soUs are those forming the so-caUed "YeUow Drift," from its predominating color. This is found in isolated patches along the southern coast of New England, over nearly the whole extent of Long Island except its extreme western parts, and thence extend- ing southwardly, composing nearly all the soils of Southern New Jersey, and of Delaware and Eastern Virginia ; it is traceable even to Florida, along the Atlantic sea-board. The salubrity of these districts has rendered them famous. Much of the territory is covered by pine forests, popularly known as the " pine barrens," and these are well known to be non-malarial ia a great many localities. This is undoubtedly largely due to the charac- ter of the " Yellow Drift " soil, composed almost exclusively of sand and gravel. These deposits have a greater antiquity than those of the Glacial Drift, and were deposited at a period when a large part of eastern North America was submerged. They are therefore also known as the " Pre- Glacial Drift." Most of our celebrated sea^side "Health Resorts" are situated on these soils, and this is probably the most potent cause of the salubrity of these places, which are found from Montauk Point south- ward. In speaking of sandy soils, we have alluded to the danger in those un- derlain by beds of clay. This is particularly applicable to these soils of stratified sand and gravel, and should be taken into account in the selec- tion of building sites. 440 AMERICAN APPENDIX TO PARKES' HYGIENE. (c) TJie Flood-plains of Bivers, Terraces, etc. — Rivera cany large quantities of solid matter, held in suspension by the water. When the rapidity of their flow becomes lessened by the expansion of the valley, or a decrease in the amount of slope, mvich of this fine silt, which is mostly clay, falls to the bottom and these valley-deposits are foiTaed. The flood- plains occupying ten-itory only sUghtly elevated above the level of the stream, form particulai-ly dangerous soils ; the impermeability of the clayey material, and the nearly level sm-face of the deposit, render the natural drainage very bad, and these soils, although rich and attractive to the farmer, are almost invariably malarial. River terraces are produced by the stream cutting through such deposits to gain a lower level, and we often find a number of these in crossing a valley, each marking a former level of the water. Being more elevated than the flood-plains they ai'e more desii'able, but the impervious nature of the deposit is still a bad feature. Lake terraces owe theii' origin to a similar cause, and are fonned of similar materials. They are particularly noticeable around the Great Lakes, and were deposited when the level of the water stood higher than at present. They contain more sand and gravel than river terraces, and are less objectionable, (d) 3Iarsh Soils consist of clay or sand, mixed with variable amounts of decaying organic matter, the result of vegetable growth, which often con- stitutes more than one-half of the mass, and this mixture is saturated with water. Hence these soils are partly composed of transported, and partly of indigenous material. Unless thoroughly drained, marsh lands are veiy dangerous, being almost always malarial, although there are some excep- tions to this statement. The growth of our large cities is, however, so raj)id, that extensive tracts of this character become unavoidably bccupied by habitations, and malarious sections of them can often be traced to this cause. Complete drainage at the outset is the only means of preventing this trouble. Unhappily, this precaution is too seldom observed. To be perfect and permanently valuable, the drain conduits should be placed low enough to rid not only the sm-face of water, but also the soil itself. Marshes are found to some extent in all sections of the country, but their greatest development is along the coasts of the Atlantic Ocean and the Gulf. The largest are the Dismal Swamp of Virginia, and the Ever- glades in Florida, Brackish swamps are popularly kno"wn as " salt meadows." ^Marsh soils which are composed for the gi'eater part of true perti, pro- duced by the abundant gi'owth and partial, slow decay of moisture-loring plants, particulaiiy the Sphagnum mosses, are aj^parently free from malarial ti'oubles. These "peat bogs" are often many feet in thickness. They are indigenous rather than transported soils, but from other relations are best here considered. The cause of this freedom from malaria is hitherto un- explained, though it may be produced by the antiseiDtic action of the or- ganic acids in the peat. Such deposits occur in limited areas in many parts of the United States, but with us never occupy the extent of tenitory covered by them in certain parts of the Old World, as Ii-eland, Central Germany, and Scandinaria in particular. In Great Britain they are kno^\Ti as "moors "or "heaths," and in America these are found only in Newfoundland, Labrador, etc. The marine alluvium forming oiu* salt meadows, composed of the de- caying remains of certain grasses and rushes, mixed with a small percen- tage of silt, also seems non-malarial when undistiu-bed, perhaps fi'om a CHABACTEES AND DISTRIBUTIOIS" OF AMERICAN SOILS. 441 similar cause to that above suggested. These " meadows " are found along the coasts, wherever land is occasionally flooded by salt water. (e) Alkaline Soils. — So much of the Far West is covered by alkaline plains that they here deserve notice. The soil is generally a light loam, some- times clayey or sandy, containing but a limited amount of organic matter, but saturated with sulphates, carbonates, or chlorides of soda, potash, mag- nesia, and lime. These salts render the waters which they carry intensely purgative, and almost useless for domestic or manufacturing purposes. Little is known regarding the salubrity of these soils, but the fact that good water must either be pumped from a very great depth or transported long distances, renders their occupation improbable except in favored localities. Another unfavorable feature is experienced in the clouds of alkali dust blown about by the winds. Geograj)hically, alkahne soils are mostly restricted in the United States to the Great Basin — the valley lying between the Rocky Mountains and the Sierra Nevada. They extend over portions of Idaho, "Utah, Wyoming, Nevada, Arizona, and New Mexico, and occupy regions formerly covered by extensive inland seas, which have now been mostly drained away by the cutting down of the river channels. The Great Salt Lake of Utah and other smaller bodies of alkaline water still remain. (f) The Sea-shore Sands. — These form important soils, as they are uni- formly healthful ; and although for many reasons they are seldom selected for permanent habitations, their salubrity is unquestionable. (g) Artificial Soils. — Under this heading we here include all deposits produced by artificially filling in low grounds. In laying out towns and villages, and the subsequent construction of streets and buildings, it gen- erally becomes expedient to bring the surface of the ground to a certain degree of uniformity by removing the tops of hills and filling up the de- pressions, which are often marshy. This practice becomes particularly necessary in large cities, where land is very valuable. The objects gen- erally sought by " filling in " are twofold : First, bringing the surface to a desirable grade ; second, depositing material on a swampy place to " dry it up," and thus escape the expense of properly draining it. The latter object is usually only apparently attained, and is always done with the very great risk of producing subsequent sickness. The great mortality in certain sections of our cities is often directly traceable to mistakes made in prepar- ing the soil for building, by this obnoxious practice, which cannot be too strongly condemned. The areas of former swamps, and the channels of former streams, now covered up, are apparent in the relative health of people residing on ground formerly occupied by them, and that of the inhabitants of districts originally dry. All such places should be thoroughly drained before grad- ing and building are begun, and the authorities should insist that these precautions be taken. If it were not for the decidedly objectionable character of the filling generally employed, such soil might be less dangerous ; but all kinds of waste matter and rubbish get mingled with the dirt, and a very unhealthy soil is the result. Besides this consideration, the mere filling up of a wet hollow does not efifect any real drying or drainage, but rather lessens the possibility of the stagnant waters disappearing by evaporation ; for the dirt becomes saturated with water, and this mixing with the organic portions produces a wet, nasty, almost invariably malaiial soil, with no chance of effective drainage. We do not protest against filling a naturally dry depression with a nat- 442 AMERICAN APPENDIX TO PARKEs' HYGIENE. urally healthy soil, and see no valid reason why it should be unhealthy. And even a soil charged ^\^.th organic matter may ultimately become salu- brious when used for this purpose, if deposited on a dry substratum, by oxidation and consequent removal of the orgaiiic matters contained ; but we do not recommend this practice. B. — Indigenous Soils. These result from the decomposition and disintegration of rocks in situ, and their amount is constantly increasing, for reasons and by agencies al- ready alluded to. The character of the rock from which they are derived determines their structure and composition, although their constituents are sometimes so much changed in the processes of decay, that chemically they may be essentially different from the original rock. Indigenous soils are greatest in amount in the non-glaciated parts of the country, where they form most of the superficial accumulations, but occur also to some extent, throughout all northern North America, wherever the Glacial Drift is thin or wanting. The presence of large quantities of Glacial Drift pre- vents or retards their formation. The most important of these soils may thus be classified : (a) Soils derived from Granite, Gneiss, Trap., PorpJiyry, and Feld spathic Bocks generally. — These are either stiff or loose clays, or loams, a true sand}' soil rarely being formed from such rocks, and they are not to be regarded as highly salubrious, although the inclination of the strata may often give sufficient slope to the surface of the deposits to provide good drainage. Soils produced from such rocks are found in patches along the eastern side of the Appalachian ^Mountain system (particularly from Western New Jersey, southward), in certain parts of the Rocky Mountain system and the Sierra Nevada, and elsewhere in the Far West. These feldspathic rocks ai'e always associated with hilly or mountainous districts. (b) Soils derived from Slates or Shales. — Clayey soils result also from the disintegration of these rocks, as they are mostly composed of this min- eral, and are dangerous, unless the strata are sufficiently tilted. Soils resulting fi-om this source are found abundantly along the southern and middle portions of the Appalachian Mountains, and in many pai'ts of the southern and central States and the Far West. (c) Soils derived from Sandstones. — The breaking down of this rock produces sandj' or loamy soils, clay never resulting from this source. These are very generally salubrious, unless rendered dangerous by local conditions of sewerage or improper disposal of refuse, which, it may be here remarked, will render the most desirable soil unhealthy. Such soils are so common south of the Glacial Drift, that no attempt at indicating their distribution need be made. (d) Soils derived from Limestones or Marbles. — Calcareous soils result from the decomposition of these rocks, and almost invariably accompany them. Even when the rocks are overspread by other deposits, the soils are usually somewhat impregnated with lime. Excepting the prevalent occurrence of hard waters, these soils are gen- erally desirable, their drainage being good. They ai'e widespread in dis- tribution. CLIMATOLOGY AND METEOROLOGY. BY J. G. EICHAEDSON, M.D., Professor of Hygiene in the University of Pennsylvania. Climatology. The problem of furnishiiig a proper definition of Climate, abandoned as hopeless by Dr. Parkes in the body of this work, is to a certain extent solved by Prof. Loomis, in his excellent treatise on Meteorology, by the following description of what it is, and depends upon. " By the climate of a coiintry we understand its condition relative to all those atmospheric phenomena which influence organized beings. Chmate depends upon the mean temperature of the year ; upon that of each month and each day ; upon the maximum and minimum temperatures ; upon the frequency and suddenness of the atmospheric changes ; upon the transparency of the atmosphere and the amount of solar radiation ; upon the moistui-e of the air and earth ; upon the prevalence of fogs and dew ; the amount of rain and snow ; the frequency of thunder-storms and hail ; the direction, force, and dryness of the winds, etc. All these particulars can only be deter- mined by long-continued and careful observations." The magnificent basis for a comprehensive system of American CHma- tology which is being rapidly laid, by the diligent observations in all parts of the country of our Signal Service Bureau, will doubtless afford us in the near future most important practical results ; but as yet the chief triumphs of this valuable department have been gained in the science of meteorology, under which head they wiU be considered more in detail. The study of chmate has been especially aided in America by the ob- servations tabulated in the admirable Isothermic maps (pp. 463, 464) for which we are so much indebted both to the Smithsonian Institution and to the United States Signal Ofiice. The subject appears therefore to require a more detailed exposition than that given in the body of this book. As Baron Humboldt in his " Cosmos " remarks, " If the surface of the earth consisted of one and the same homogeneous fluid mass, or of strata of rock having the same color, smoothness, density, and jDower of absorbing heat from the solar rays, and of radiating it in a similar manner thi'ough the atmosphere, the isothermal, isotheral, and isochimenal lines would all be parallel to the equator. In this hypothetical condition of the earth's surface the power of absorbing and emitting heat would everywhere be the same in the same latitudes." But as such is by no means the case, we find an infinite variety of tem- perature, humidity, and amount of rainfall existing at places upon the earth's surface at the same distance from the equator. Hence places having exactly the same latitude may possess widely different climates. 444 AMERICAN APPENDIX TO PARKES' HYGIENE. As observed by Surgeon General Hammond, " the climate of the United States is colder than that of European regions of the same latitude, but warmer than places similarly situated in Asia. Thus the fortieth parallel of north latitude passes through Philadelphia, and the forty-first runs a few miles north of Naples. The mean annual temperature of the former place is 54.57°, as determined from observations extending over six years (for twenty-four years ending 1876 the mean was 54.51''), while of the latter it was 62.06°, as deduced from observations continued through eighteen years. The fortieth parallel also passes through Pekin, but there the mean annual temperature is but about 52°." Dr. Hammond thinks that the theories which seek to explain these re- markable variations on the ground that different proportions of the soil are under cultivation in Europe and America, are insufficient, and that the probable causes exist in the facts that the prevailing winds of Europe come from the Atlantic ocean, and being loaded with moisture, give out their latent heat as the vapor they carry with them is condensed into rain, and that the Gulf Stream, rushing out of the Gulf of Mexico heated to over seventy degrees, sweeps along the northern coasts of Europe and mitigates their frigidity. Moreover, Europe extends north to about the seventy-first degree only, and is then bounded by an open ocean ; whereas tlie conti- nent of America extends to the eightieth degree of north latitude, and is enclosed by a sea of ice. " From this region cold winds proceed, untem- pered by passing over any intervening water, and reduce the temperature of the whole of North America." Thus, for instance, the Isotherm, or Iso- thermic hne of 51°, upon which occurs the same mean annual temperature of 51°, enters our Pacific coast high up near Vancouver Island, on the border of British America, crosses the continent in an irregular diagonal toward the Mississippi Eiver near St. Louis, passes almost through New York, curves upward again toward the Arctic cii'cle in the Atlantic, in con- sequence of the Gulf Stream, descends in Great Britain so as to pass nearly through London, traverses Russia near Odessa, China near Pekin, and Japan near Kanagawa. As a general result of the investigations upon which isothermal charts are founded, we find that in the northern hemisphere, the west side of the continent is the warmer, and the eastern colder, although to this general- ization a few exceptions are met with. Even in the island groups of the northern half of our globe, this rule generally holds good, the tempera- ture of those upon the eastern coast being cold, whilst those upon the western coast are relatively warmer. In the southern hemisphere the case is reversed, the eastern side of the continents being warmer than the western, so that the Isotherms which pass over South America and Africa, curve downward upon the map, that is away from the equator, in crossing these continents, in consequence of a mean annual temperature of 70°, for example, being found nearer the south fi'igid zone, upon the eastern than upon the western coast. The appended Isothermic maps, copied by the kind permission of the Office from "Professional Papers of the Signal Service, No. 2," show at a glance the mean monthly temperature for January (winter), and for July (summer), during the ten years preceding 1881, for different portions of the United States. They constitute some of the most important contributions to practical Hygiene yet furnished from the Signal Service Bureau, and being thor- oughly accurate and rehable, will no doubt frequently aid our readers in judiciously directing invalids, especially phthisical patients, for whom they CLIMATOLOGY AND METEOEOLOGY. 445 are anxious to secure the potent remedial effects of removal to a more suitable climate. In the United States the hottest portion is the southern end of Florida, and next to this rank Southern Texas, and Southwestern Arizona. The mean annual temperature of the whole country is not far from 53° F. The areas of territory having a mean annual temperature above 55°, comprise the entire cotton region, those above 70° the sugar and rice regions, and between 50° and 60° is included most of the tobacco region. As may be seen by consulting the accompanying Isothermic maps (pp. 463, 464), the cotton-growing sections lie between the Isotherms for July (the hottest month), of 75° and 85°, the winter limit of the cotton region being that of the Isotherm of 35° for January nearly. The regions ranging between 75° and 85°, average July temperature, appear to include all those portions which are liable to epidemics of yeUow fever. The coldest regions are found in the noi-thern part of New England, Northern Michigan, Wisconsin, and Minnesota, and the high mountain re- gion of the Cordilleras. On the whole Atlantic coast from Penobscot Bay to the mouth of the Eio Grande, and the whole coast of the great lakes, besides a considerable portion of the Pacific coast, the highest observed temperatures range from 95° to 100°. The Atlantic plain stretching from the eastern base of the Appalachian system of mountains to the neighborhood of the coast, and nearly all of the Mississippi VaUey, range in their highest summer tem- perature between 100° and 105°. This difference is, of course, due to the absence of any cooling influence from the Atlantic sea breezes. The highest maximum temperature is reported from Southwestern Ari- zona, and from Southwestern California, where the thermometer is said to have registered 135° in the shade. The average maximum on the Pacific coast is lower than on the Atlantic coast, ranging between 90° and 100°, but at some distance inland in the great valley of California the elevated temperatures mentioned are met with. The distribution of population in accordance with mean annual tem- perature, throughout the wide domain of our Union, is a question of much interest, and valuable light has been thrown upon it by recent bulletins from the Census office. According to these Government statistics, it appears that ninety-eight per cent, of the total population of the United States reside in regions the mean annual temperatures of which range between 40° and 70° F. ; eighty- two per cent, dwell in sections which have a mean annual temperature of 60° or under ; sixty-nine per cent, in regions where the temperature is at or below an average of 55° ; and thu-ty-eight per cent, inhabit portions of the country the highest mean annual temperature of which is 50°. From the same source we also learn that ninety-seven per cent, of our fellow- countrymen are exposed to summer heats which have a range of 20° only, lying between the mean temperatures for July of 65° and 85° F. This leaves a scattering fringe of population of only three per cent, outside of these Hmits, who suffer a more intense average heat or cold. The brief but interesting statements of Professor Parkes in the text of this work, under the section treating of the effect of lessened pressure of the air as a climatic factor, and especially in its relations to Phthisis, may be appropriately supplemented here by some account of our own health resorts, which have been especially studied by American physicians in reference to that most fatal disease upon most of death registers of the Northern States — pulmonary consumption. 446 AMERICAN APPENDIX TO PARKEs' HYGIENE. Among the most valuable of the inland resorts, so useful as refuges from the rigors of a northern winter in New England and the Middle States, must be mentioned Aiken, S. C. Aiken is built on the water shed between the Savannah and Edisto Rivers, and possesses the great recommendation of a Ught porous soil from which the numerous rains readily drain off. It is situated near the iso- therm of 48° mean winter (January) temperature, and therefore enjoys great advantages over New York and Philadelphia, which he, it may be remembered, near the isotherm of 30° for the same month. The town possesses several excellent hotels and boarding-houses, good markets, agreeable society, and visitors can enjoy many pleasant walks and di'ives over the neighboring country. It is 120 miles from Charleston and 67 miles from Augusta, Ga., with both of which it is connected by rail. Phthisical patients who seek the benefits of cHmate at Aiken can, therefore, best reach their destination by taking passage by steamer from noi-thern ports to Charleston, unless symptoms of active pidmonary congestion or actual haemoptysis render a sea-voyage unsafe. No signal service reports from Aiken are available, but those from At- lanta, seventeen miles distant, give a mean (coiTccted) barometric pressure for 1880 of 30.063 inches, with variations during twelve months, from a minimum in March, 1881, of 29.425 to a maximum in November, 1880, of 30.603 inches. The average temperature for 1880 was 62.1° F., the ex- tremes being 94° in July and 1° in December. In November, 1880, the mean temperature was 47.7° ; in December, 42.4° ; in January, 1881, 40.1° ; in February, 46°; in March, 48.7°, and in April, 59.1°. The rainfall at Aiken is rather high, averaging about 55 inches, and that for Atlanta being, in 1880, 62.7 inches, of which 8.21 fell in November and 5.7 in December, and in January, February, and March, the monthly precipitation was 8.35, 10.41, and 10.98 inches, respectively. The relative humidity of Atlanta in 1880 averaged 66.7. The prevaihng winds at Aiken are from the S.W., and are fairly warm and dry, although they alternate occasionally with N.E. and E. winds, which are very trying to the invalid. Phthisical patients are said to improve at Aiken for a month or six weeks veiy satisfactorily, and then become subject to disappointing re- lapses. Hence it is a good locahty to direct a patient to if he has con- tracted suspicious bronchitis, or has developed slight symptoms of pul- monary deposit during February, in a more northern latitude. March can be agreeably spent at Aiken by such invalids, but they are apt to find the heat oj^pressive by the middle of April, and it then becomes preferable to move slowly northward. A physician of large personal experience has given his oiiinion, that sojourning in Aiken through December and part of January, and then going back to it in March on the way homeward, after a toiu' through Florida during the latter half of January and the whole of February, is a programme which suits most consumptives better than a continuous residence for the winter in either one or the other of these places. An important consideration to invalid tourists is that malarial dis- eases are nearly or quite unknown among the inhabitants of Aiken. In regard to the climate of Florida, it is probable the northern part of the State has little advantage over Aiken and Savannah, although great numbers of consumptive patients visit and spend some time in Jackson- ville, being attracted by its superior accommodations and ease of access. Indeed, many remain at this point who would perhaps be improved by a nearer appi'oach to the equator, where, as for example at Enterprise, the balmy aii- and bright sunshine (which contribute to give the peninsula its CLIMATOLOGY AND METEOEOLOGT. 447 name of " the Land of Flowers " ) are Tery important and valuable to the invalid. The mean height of the barometer, for 1880, at Jacksonville was 30.108 inches. The mean temperature for the same year was 70. 1'', with exti'emes diu'ing twelve months ranging from 99^ in June, 1881, to 19^ in December, 1880. The mean temperature for November, 1880, was 61.2° ; for Decem- ber, 52.2^ ; for January, 1881, 52.7° ; February, 57.9° ; March, 59.5° ; the mean relative humidity was 71.8, and the rainfall for 1880 amounted to 65.51 inches, of which 16.25 inches fell in the month of September. The various resorts upon the St. John's River in Florida, in the neigh- borhood of and southward of Entei^Drise, possess the advantages of an equable climate, moist warmth," abundant opportunity for outdoor life, and a good sup2:)ly of small game and fresh fruits. The chief drawbacks are the de- ficiency of milk and of good fresh meat, and the presence of insects, rep- tiles, and malaria. To obtain the greatest benefit from the chmate one must absolutely live in the open ah', from an hour after sunrise to half an hour before sunset. The climate of Key West, on the southern extremity of Florida, is said to be the warmest and most equable on the eastern coast of the United States. Even in January the south winds are frequently oppressive and debilitating. From five to ten " northers " occur every winter, and though they are disagi'eeable on account of the riolent wind, they do not often reduce the temperatui'e below 40°. Dr. D. G. Brinton (" Florida and the South ") says in regard to Key West, though the proximity of the Gulf Stream renders the air very moist, mists and fogs are extremely rare, owing to the ecjuability of the temperatiu-e ; and though the hygrometer shows that the air is constantly loaded with moisture, this same equability allows the moon and stars to sliine with a rare and glorious brilliancy, such as we see elsewhere on dry and elevated plateaux. Another effect of the Gulf Stream may also be noted. Every evening, shortly after sunset, a cloud bank rises along the southern horizon in massive irregailar fleeces, dark below and silver gilt above by the rays of the departing sun. This is the bank of clouds over the Gulf Stream, whose vast cuiTent of heated water is rushing silently along some twelve miles distant. The mean height of the barometer at Key West for 1880 was 30.076, the mean temperature for the same year was 78.7°, with extremes dui'ing twelve months ranging from 97° in July, 1880, to 56° in March, 1881. The mean temperature for Novem- ber, 1880, was 78.5° ; for December, 70.1° ; for January, 1881, 72.2° ; for Februaiy, 70.9° ; March, 70.6°, and for April, 75.0° ; the mean relative humidity for 1880 was 73.4, and the rainfall for the same year only 33.41 inches, of which but 0.71 inch was precipitated in December. Although much injiuy to the health is often experienced by the invalid from the malarious affections contracted in the interior of the State, the sea-coast of Florida is said to be entirely exempt from these dangerous maladies, at least dui-ing the late autumn and winter months. The humid atmosphere, which while it tends to ease cough in some instances, does appear in others to promote the softening of tubercular deposit, and the frequently crowded condition of the hotels and boarding-houses, which often compels patients affected with incipient phthisis, to hear and see the sufi'erings of others in the advanced stages of their own disease, are the chief di'awbacks to the incontestable benefits which this charming climate affords in many instances. The climate of the West Indies is mild and balmy, and cases of phthisis often improve for a few weeks after their arrival in Havana, Barbadoes, 448 AMERICAN APPENDIX TO PAKKES' HYGIENE. etc., as well ■ as in the Bermudas and tlie Bahama Islands. Under these circumstances patients gain rapidly in weight, often, it is said, at the rate of three or four pounds a week. But after a month or two this temporary improvement is apt to be followed by a period of depression, especially if the debilitating heats of early spring happen to come on, and if the home- sick sufferer should incur a bronchial attack, as often is the case during his voyage back to Charleston or Savannah, all, and it may be more than all, the advantages previously gained are soon sacrificed. The climate of Texas has of late years been growing in favor as a rem- edy for consumption, although in the State itself a well-founded popular, as well as medical opinion, demands that the phthisical patient should spend the whole year and not a jDart of it only, in that region, if he hopes for arrest of his disease. The atmosi^here of the Texan table-lands has the great advantage over tliat of Florida, of being dry instead of moist, at the same time that it is sufficiently warm, and therefore allows likewise abun- dant outdoor exercise, and promotes freedom from catarrhal attacks. Great dryness of the air appears to have a directly curative influence over some cases of pulmonic phthisis, and really to arrest or prevent the soften- ing of tuberciilar deposit. Prof. H. C. Wood, in a recent article on this subject, states that Santa Fe, which is the capital of the Territory of New Mexico, has probably the most attractive climate of the whole arid belt which stretches over hun- dreds of miles through New Mexico and Texas. It is situated on an ele- vated jilateau about seven thousand feet above the sea-level, and this moderate elevation, which is not in most instances sufficient to affect the consumptive seriously, is enough to give immunity from the excessive heat. This elevated temperature in the whole of the Texan Rio Grande region is terribly severe, and rendered the United States Post at Presidio so intoler- able that it had to be abandoned. Dr. Wood informs us that the com- manding officer reported the thermometer as standing frequently at mid- night during the month of June, at 110^^ Fahr. in the coolest of the dwellings in Presidio. From such intense heat tlie climate of Santa Fe affords an invalid visitor therefore most welcome relief. The mean height (corrected to sea) of the barometer at Santa Fc for 1880 was 29.809 inches, the mean temperature for the same year 45.4°, with extremes during twelve months ranging from 11° below zero in November, 1880, to 92° in June, 1881 ; the mean temperature for November, 1880, was 29.6° ; for December, 29.4°; for January, 1881, 23.7° ; for February, 33.6° ; for March, 86.7'^, and for April, 51.2°. The mean relative humidity for 1880 was 45.9, and the total rainfall for 1880 only 9.89 inches, of which but 0.94 inch was precipitated in November and December of that year. In regard to the climate of Minnesota, which although less in vogue than formerly, perhaps, is still visited by many of the less debilitated phthisical patients, we find by the Signal office reports that the mean height of the barometer at St. Paul for 1880 was 29.926 inches, the mean tem- perature for the same year 44.1° with a range during twelve months from — 27° in December to 98° in August of 1880. The mean temperature for November, 1880, was 22.2° ; for December, 13.9° ; for January, 1881, 7.7° ; for February, 17.1° ; for March, 30.3° ; and for April, 43.1°. the mean rela- tive humidity for 1880 was 69, and the amount of rainfall in the same year 29.76 inches, which was precipitated as rain on eighty-two days, and as snow on fifty days during the year. Dr. Staples, of Minnesota, claims that owing to the geographical position of his State, the altitude and general physical condition of the surface of the country, the nature of the soil, the CLIMATOLOGY AISTD METEOROLOGY. 449 temperature and comparative dryness of the atmosphere, the character of the sun's Hght, the freedom from all forms of paludal poison, and to other causes, the climate of Minnesota is stimulating and favorable in its effect upon diseases of the lungs and air-passages, which are dependent upon and characterized by debility, imperfect digestion and assimilation, and the tubercular or strumous diathesis. Also, that the beneficial effects of the climate are largely due to influences exerted directly or indirectly upon the functions of nutrition. And lastly, that acute lobar pneumonia is not to any great extent prevalent in Minnesota, although chronic forms of pneumonic inflammation do occur, and that the cases of phthisis originat- ing in the State have been generally of pneumonic origin, but that this does not conflict with the fact that phthisis contracted elsewhere, and under different climatic conditions, may be benefited by influences exist- ing in Minnesota. Dr. Staples considers this final conclusion verified, espe- cially by observing the large number of the present inhabitants of the State, now in good health, who came from other localities as invalids, suffering from evident phthisis pulmonalis, either caseous or tuberculous ; he closes with the usual caution against expecting that merely temporary residence is likely to result in permanent benefit to the consumptive. The pure dry atmosphere of Colorado, the surpassing beauty of its nat- ural scenery, and its great comparative accessibility, by way of the Pacific railroads, have contributed to develop this part of the eastern slope of the Kocky Mountains into a grand sanitarium for consumptives. The mean altitude of the barometer at Denver, Col., for 1880, corrected for its 5,294 feet above the level of the sea, was 29.980 inches ; the mean annual temperature was 47.4°, with a range during twelve months from 95° in July, 1880, to —20°, in February, 1881; the monthly average for Novem- ber, 1880, was 22°, and for December, 29.9° ; the mean relative humidity was 48.4°, and the amount of rainfall 9.58 inches, precipitated as rain on thirty-eight days, and as snow on thirty-nine days during the year. Dr. Dennison, of Colorado, who has written extensively upon this subject, con- tends that since lessened barometric pressure, corresponding to 24 or 25 inches, has been shown to form an important factor in successful climatic treatment of phthisis, the resort to a well-chosen elevated climate should constitute part of a physician's advice to every consumptive who can follow it, and for whom the elevation is not specially contra-indicated. Dr. Den- nison claims that the "favorable or positive influence of high altitudes upon the progress of consumption is best shown in the commencement of chronic inflammatory and hemoirhagic cases, and generally in fibrous phthisis in young and middle aged subjects, with little constitutional dis- turbance. The unfavorable or negative influence of high altitudes upon the progress of consumption is mainly seen in proportion as the disease approaches or is complicated with the following conditions, which are in- tensified by an irritable, nei-vous state, and lack of desirable will-power, aided by the stimulus and hope of youth ; i.e., First, cardiac disease, if associated with increased labor and abnormal activity of the heart. Second, the stage of softening in acute cases and with extensive deposit. Third, chronic third stage cases with from one-third to one-half the lung surface involved in diseased changes, if the thermometrical and other usual signs of consti- tutional disturbance are present in a marked degree." It is true that in classifying, according to the two rules of Dr. Denni- son just quoted, any particular patient in one or the other group, we have decided almost as much respecting the prognosis of the case, as in regard to the propriety of sending it to Denver, but as indicating with certainty Vol. IL— 39 450 AMERICAN APPENDIX TO PAEKEs' HYGIENE. those consumptives wlio should no/ venture into an elevated region, these sug- gestions have, we think, a definite value to the medical profession at large. The most injurious efifect of a rarefied atmosphere upon a phthisical patient is the promotion of hemorrhage (perhaps a fatal haemoptysis), and this is so decided at the elevation of Denver, that it is common to recog- nize a new-comer, or "tendei-foot," by the spots of blood upon his hand- kerchief. This danger is so indisputable, that Dr. Dennison further ad- vises that in serious cases, approach to the region of high altitude should be gradual, or even at the snail's pace of an emigi-ant wagon, for example. The ascent should, moreover, be guided by observations carefully made upon the degree of disturbance which circulation and respiration undergo, in any particular patient, at lesser elevations. Such caution should be especiaUy practised by those in whom hemorrhage or acute symptoms ex- ist or are easily excited. Another disadvantage of the climate of Colorado, is the severity of its winters, which deprives very delicate patients of much of that continuous out-door life, constituting so large a factor in the cure of curable con- sumption. The chmate of Cahfomia has attracted much attention during the last twenty-five years as a resort for phthisical patients, one of its great rec- ommendations being that it is singularly equable, the country around San Fi-ancisco, and especially on the elevated table-lands high up on its sur- rounding hill-sides, being seldom touched by frost. On these bits of table- land whilst the au- below may be foggy and chilly, as is very common at some seasons, the invahd may enjoy a brilliant sunshine, and a crisp, dry, invigorating air which invites to plenty of active out-door exercise. The days in these uplands are praised as being neither too hot nor too cold, and yet the night always brings enough coolness to render sleeping under blankets agreeable. The mean altitude of the barometer in San Francisco for 1880 was 30.051 inches, the mean temperatiu'e for the same 3'ear, Si. 2°, with a range, during twelve months, between a maximum of 79"^ in September, 1880, and a minimum of iO" in March, 1881. The mean temperatvire of the month of November, 1880, was 53.9° ; of December 53° ; of January, 1881, 53.7°; of Febmary, 54.9°; of March, 53.8°; and of April, 57.1°. The mean relative humidity for 1880 was 75.6, and the amount of rainfall 30.07 inches, which was all precipitated as rain on seventy days in that year. The southern portions of California are also very highly praised as health resorts for consumptives, on account of their suj^erb climate. Thus, for example. Dr. Adams of Oakland, Cal., who went to the coast about the year 18G3 an invalid, and has been fully restored to health, declares that while Monterey, Santa Cruz, Santa Bai'bara, San Diego, and Los Angeles are the most desirable of the many Pacific coast resorts, he considers, for a locality combining all requisites, Monterey stands at the head of the list. "It is delightfully situated at the southeasterly extremity of Monterey Bay, about one hundred and twenty-five miles south of San Francisco, and connected with it by the Southern Pacific Eailroad, which passes through some of the most fertile and beautiful valleys of the State. Here there is security from both cold winds and excessive mid-day heat. Contrary to the generally received opinion, that we have an almost continuous rainfall in the winter, this season is more hke the Eastern [Atlantic coast ?] spring weather in May and June ; and diuing the rainy season or winter months, we have more sunny days than any other portion of the United States." Dr. Adams asserts that for the multitude of people in the Eastern and Mid- CLIMATOLOaY AND METEOROLOGY. 451 die States, who are suffering from bronchial difficulties, incipient consump- tions, hereditary or acquired, or from the nervous exhaustion of mental overwork and various other causes, and who therefore dread a long, cold, and changeable winter, the climate and health resorts of California are supe- rior to most, and second to none in the world. He urges most emphati- caily, however, the eminently wise counsel that persons with organic dis- ease of the lungs in an advanced stage, should alivays remain at home where they can have the loving attention of family and friends. The south- ern California Channel islands are strongly recommended as health resorts by Dr. J. P. Widney, who asserts that their peculiar merit is that while lying within the line of a semi-tropical climate, they are entirely exempt from the scourges of yellow fever, bilious remittent, and ague ; and their comjjaratively small size, and distance from the main land save them from strong sea-breezes and coast-fogs, and secure for them a remarkably equa- ble temperature. The mean altitude of the barometer at Los Angeles, Cal., for the year 1880 was 30.007 inches, the mean temperature for the same year 58 4°, with a range during twelve months from a minimum of 35° in November, 1880, to a maximum of 94° in April, 1881. The average temperature of November, 1880, was 55.5° ; of December, 55.3° ; of January, 1881, 51.7°; of February, 57.9° ; of March, 55.8° ; and of April, 61.4°. The mean relative humidity for 1880 was 69.7, and the amount of rainfall 18.65 inches, all of which was precipitated in the form of rain on a total of fifty- one days during the j^ear. These remarks upon climate as a remedial agent, especially in pulmon- ary complaints, would be incomplete without a few suggestions in regard to practically utihzing such items of information in the management of phthisis. With respect to temperature, a uniform cold chmate, such as that of Minnesota or Colorado, is the best for some cases ; and, on the other hand, for others a change to a warm chmate has appeared to accomphsh all that could be desked. In deciding this branch of the question Professor A. Flint very judiciously advises that the feelings and choice of the patient should have considerable weight. If, for example, we find on inquiry that the invalid when in health habitually experienced more vigor and enjoy- ment in summer than in winter, removal to a warm climate would probably be best suited to his case, but if the reverse is true, a cold climate is to be preferred. Moreover the condition as regards feebleness has an important bearing upon the problem. If the patient is so feeble as not to be able to live out of doors in cold weather, or if the reaction from the impression of cold be slow and imperfect, a warm climate is more suitable. Dr. Brinton wisely suggests, in addition, that cold climates such as Minnesota, Labrador, or the Canadian highlands, are better adapted to patients who are not or- dinarily subject to catarrhs, irritation of the pharynx, coughs, pneumonia, and pleurisy ; are not plethoric ; are free from rheumatic, neuralgic, and gouty pains, which become worse as winter approaches ; whose throats are angemic rather than congested ; whose livers are torpid ; and who are op- pressed and enervated by heat. The danger of hemorrhage in cold and especially elevated regions has already been referred to. In some doubtful cases invaluable aid may be derived from an examination of the sputum microscopically, after liquefying by boiUng with caustic soda solution ac- cording to Dr. Fenwick's method. ' ' See my paper on Pulmonary Elastic Tissue in the Early Diagnosis of Phthisis : Transactions New York State Medical Society, 1872. 452 AMEEICAN APPENDIX TO PARKEs' HYGIENE. Ozone and Rainfall. Dr. Parkes has declared in the text that, in spite of the difficulties attending them, observations on ozone should be continued. Since he wrote this his advice has been followed both here and abroad, and some of the American contributions toward unravelling the mystery which sm- rounds the influence of the curious substance ozone upon human health are here epitomized for the benefit of our readers. A recent writer in the Science Weekly reports that the results of his ob- servations confirm those of Houzeau ; namely, that a wave of ozonization foUoivs the storm-wave (as that of neuralgic influence, see page 454, ac- companies it on the side), but lagging from twelve to forty-eight hours be- hind it, and appreciably corresponding, in intensity and duration, to the force and continuance of the air-Avave which precedes that of ozone. This gentleman made use of ozonized test-papers, prepared from starch and iodide of calcium, and while admitting the force of objections to the complete accuracy of his method contends that the comparative coloration of such papers is a valuable guide to the relative condition of the atmos- phere in regard to ozone. The coloration obtained was certainly in great measure due to ozone, and its increase or decrease was probably caused in the same proportion by this agent. It is acknowledged that the con- temporaneous influence of nitrogen oxides may have deepened the tints, but it could scarcely have nevitralized them, and insomu.ch as the j^apers were kej)t moist any error from the var3ing humidity of the air was in great measure cancelled. Duplicate observations were made at ten feet, and at forty feet from the surface of the earth, and the average of these, although nearly always the two sets of results proved identical, was re- corded as the color mark of the hours they were exposed. In regard to the practical minutiae bearing upon the application of this test, it was noticed that at the periods of strongest ozonization the paj^ers were changed tluroughout, while at other times they were marked at spots and near the edges, showing an unequal sensitiveness to the reagent. In supple- mentary trials to determine the eftect of the wind it was found that those papers exjDOsed to a strong current of air were sometimes one-third deeper in tint than the jDrotected ones, and reached their maximum much quicker. These contrasts were of course much lessened with a diminished velocity of the wmd. Dr. A. W. Nicholson, one of the most recent investigators of the re- lation of ozone to health, furnishes an imj)oi*tant paper uj)on the subject to the "Michigan Health Board Report for 1881." Dr. Nicholson takes issue with Pettenkofer, who asserts that the hj^gienic value of ozone does not seem to be very great, since it can never be detected in our dweUiugs, where we sjsend the greater part of our lives, and are better than if ex- posed in the open aii*. He attributes the failure of Pettenkofer and others to detect ozone in the air of inhabited apartments to the decolorizing action of carbonic acid, or carbonic oxide, from our fires, interfering with the action of Schonbein's test. After admitting the difficulties surrounding accurate determination. Dr. Nicholson suggests that when using Schon- bein's test, in order to obtain the best results of an observation, where it is necessary to guard against excess of moisture, the exposure of a wet and a dry shp of the prepared paper at the same time appears to be the proper method to adopt. Also it is well to suspend these slips at points where the condensation of moistm-e would be least apt to occur. To render the CLi:\rATOLOCTY AXD METEOROLOGY. 453 paper more sensitive so as to occupy a shorter period of time in making an observation Avould also be a great desideratum. It is ■well known that increased velocity of the wind may bring more ozone to a given point than if that rapidity were less. To detei-mine the quantity of ozone hkely to af- fect the health of an individual subjected to the influence of rapid currents of air, it is desii'able to expose the test-paper to the same atmospheric cur- rent. And yet the loss of liberated iodine, to which the darkening of the paper was due, by evaporation, as an eiJect of just such a current, suggests that perhaps the deepest coloration of the slips of test-paper may be ob- tained, not when the amount of ozone is the greatest, but when the test- paper is best protected from too great velocity of wind, especially when there is an excess of nioistui-e in the atmosphere. Dr. Nicholson found ozone more abundant in a pine forest than in the open country during the summer, but less abundant in the winter ; less abundant in coal-pits and over swamps than in the open country ; and less abundant generally in the night than by day. The results of these inves- tigations in regard to the air of pine woods are in accord with the state- ments of Schreiber, of Vienna, who informs us that the turpentine exhaled from pine forests possesses, to a greater degree than all other bodies, the property of converting the oxygen of the air into ozone, and by this fact it has been sought to explain why a continued residence among the bal- salmic odors of the pines has long been credited with a favorable influ- ence in cases of phthisis. Dr. Day, of Geelong, Austraha, in an able pa2:)er pubhshed some years since, also sustained similar views in regard to the activity and value of turpentine as an ozonizer. The cai'eful and svste- matic observations now being carried on under the auspices of Dr. H. B. Baker, the energetic Secretary of the Michigan State Board of Health, give promise of some very important additions to our knowledge of the relations between ozone and health during the next few years. Ozone is stated by Dr. John Mulvany, in a paper contributed to the " Michigan Health Board Report for 1880," to have a marked influence upon the human procreative functions. Dr. Mulvany declai-es that in a xery .extended series of obseiwations, carried on in all parts of the habitable globe, he has repeatedly found the births few where ozone is scanty, and numerous where it is abrmdant. The most positive evidence in support of this theory he obtained in Trincomalee in Ceylon. The village is low, but httle above the sea-level, open to the sea on the N. E., and with the jungle on the S. W. Fi'om May to September the S. W. monsoon blows over the island, and in passing thi'ough the jungle is robbed of its ozone. From October to Apiil the X. E. monsoon blows over the bay of Bengal, and anives at the village laden with ozone. During April the winds veer from N. E. to S. W., and the ozone is in fair proportion. Such peculiar conditions afforded a very suitable opportunity for observing the effect of ozone on the chances of fecundation among the Ceylonese villagers, and on overhauling the baptismal register kept by the Eoman Cathohc jDriests, Dr. Mulvany found that during the S. "W. monsoon, a period extending from May to September, with a relative proportion of ozone expressed by two and one-haK degrees on SchiJnbein's scale, the conceptions were only fifty-seven per cent, of the number occurring in the period from October to April, when the amount of ozone was represented by eight degrees, or more than three times as much. The average annual rainfall upon the surface of the United States, ex- clusive of Alaska, is approximately 29 inches, that for the spring and sum- mer months is about 17 inches, and the entu-e range for these months is 454 AMERICAN APPENDIX TO PARKEs' HYGIENE. from to 38 inches nearly. According to some curious investigations repoi'ted in Census Bulletin No. 174, published June 3, 1881, the average rainfall with relation to population — that is, giving weight to each area of the countiy in proportion to the density of its popu.lation — was in 1870 43.5 inches ; in 1880 this had decreased to 42.9 inches owing to the move- ment of population toward the arid regions of the far West. More than seven-tenths of the people of the United States are settled in regions where the average annual rainfall is between 35 and 50 inches ; nine- tenths of the inhabitants reside in areas of country where the rainfall averages between 30 and 60 inches ; and ninety-five per cent, of the popu- lation is found in sections where the average rainfall dui'ing the spring and summer months ranges between 15 and 30 inches. Electricity. A very important American contribution to our knowledge respecting the probable relations of electricity to disease, especially to neviralgic attacks, has been made by T>i\ S. Weir Mitchell, of PhiladeliDhia, who in an ai'ticle in the American Journal of the Medical Sciences for April, 1877, de- scribed the remarkable case of Capt. Catlin, U. S. A., and gave the results of his observations upon the connection between states of the weather and his pain. Dr. Mitchell concludes that there seems to be every reason to believe that the popular view which relates some fits of pain to storms has a distinct foundation, having stood the test in this single case of a long and patient scientific study. He could not determine which of the sepa- rate factors of storms (lessened pressure, rising temperature, greater hu- midity, or winds) caused the neuralgia, or whether some yet unknown agency, perhaps electricity or magnetism, was productive of the evil. The study, however, led at that time to the still more novel and valuable con- clusion, that every stoi-m as it sweeps across the continent (see Meteor- ology, page 461) consists of a vast rain area, at the centx-e of which is a moving space of greatest barometric depression, known as the storm- _ centre, along which the storm moves like a bead on a thread. "The rain usually precedes this by 550 to 600 miles, but before and around the rain lies a belt which may be called the neuralgic margin of the storm, and which precedes the rain about 150 miles. This fact is very deceptive, because the sufferer may be upon the far edge of the storm-basin of baro- metric depression, and see nothing of the rain, yet have the pain due to the storm. It is somewhat interesting to figure to one's self thus — a mov- ing area of rain gix'dled by a neuralgic belt 150 miles wide, within which, as it sweeps along in advance of the storm, prevail in the hurt and maimed limbs of men, and in tender nerves and rheumatic joints, renewed torments called into existence by the stir and perturbation of the ele- ments." In a further report upon this interesting subject, made to the Philadelphia College of Phy.sicians June 6, 1883, Dr. Mitchell and Capt. Catlin state that it is firmly believed that neixralgia accompanies periods of intense auroi'al displays, but owing to their rare occvuTence it cannot be said that proof is conclusive. Yet the connection of the two seems too frequent for mere coincidence. In the remarkable case which has formed the chief subject of Dr. Mitchell's investigations there occurred, after an intense magnetic storm without ordinary weather disturbances, on Novem- ber 17, 1882, at two in the aftei'noon, "intense stabbing neui-algic pains, which continued with great force until 5 a.m. on the 18th, and intermitting CLIMATOLOGY AND METEOROLOGY. 455 and less strong fits of torment were felt imtil the evening of that day. This intense neuralgia of the 17th seems connected with the magnetic storm of the 17th, for there was no storm of barometric depression charted by the Signal Bureau within neuralgic range for that date," In order to determine the average distance of the storm-centre at the beginning of attacks of pain in this interesting case, special observations were made on sixty well-defined storms occurring in ten consecutive months, and these showed a sphere of influence of from 200 to 1,200 miles, and an average of 680 miles. Storms coming from the Pacific coast were felt the farthest off, in fact soon after they began to descend the eastern slope of the Kocky Mountains. Those which moved along the coast from the Gulf of Mexico were associated with a neuralgia not quite so in- tense nor so quickly perceived. If neuralgia begin with a low or rising- barometer, the ridge of depression is narrow and invariably broken down within seventy-two hours, and more frequently within twenty-four or thirty-six hours ; and during this rise coincident with the pain, the differ- ence between the wet- and dry-bulb thermometers, instead of increasing, as is usual with this barometrical condition, sometimes actually dimin- ishes, or increases for a few hours only, and then diminishes, showing in- creasing humidity. When pain occurs with this instrumental condition the coming storm depression will carry on its eastern side clouds and increas- ing moisture and sometimes rain or snow, clear over the summit of the advancing high area pressure (high pressure area ?) in front of it, holding an unusually high degree of relative humidity in the air, on the high east- ern slope of the high barometer area. These are the conditions under which attacks of pain come on with the rising barometer. Its usual condi- tion is with a falling, but it may be a high barometer, rising temperature, and increasing relative humidity. Should the pain be on during a day of intermitting rain, the pain as- sumes an additional activity just before the increasing shower, and con- tinues twenty or forty minutes ; this will sometimes happen four or five times in twelve hours. Each little increment of pain seems to bear about the same relation to the showers as the main attack bears to the storm. The protection of human life and health from the injurious action of electricity on the grand scale upon which nature displays it in thunder- storms is obviously a part of Preventive medicine, and it seems proper, therefore, to add a few words respecting it in this place. Such reference is the more appropriate here since French sanitarians devote considerable attention to the subject, and even in their elementary books for the secondary schools (into all of which the study of hygiene has been intro- duced by law, according to the decree of May 6, 1872) the ancient riiles of our venerated Dr. Franklin are still reverently mentioned. And indeed such honors appear by no means ill-deserved when we consider that the kite-string in Franklin's memorable experiment in a field (as it was then) near Philadelphia has become the progenitor, not only of the multitude of lightning-rods which protect dwellings in every part of the civilized world, but also of the marvellous network of telegraph wires and of ocean cables which during the last half-century have so vastly modified the social and mercantile life of mankind. The electricity of the atmosphere is the result of physical causes, such as the movement and pressure of the air, friction against the earth, dif- ferences of temperature, and chemical reactions. It is asserted by some that our planet is charged with negative, and celestial space with positive electricity, but at any rate there is httle doubt that lightning is only an 456 AMERICAN APPENDIX TO PARKEs' nYGIENE. enormous electric spark, passing from one cloud to another, or from a cloud to the earth, and temiDorarily restoring the disturbed equilibrium of electrical tension. The effects of a thunderbolt are very variable. Sometimes when a per- son is directly in the course of the discharged electricity death takes place instantly and without anj^ apparent wound. In other cases, where indi- viduals happen to be situated at what might be called the side of the bolt, they may nevertheless experience more or less serious injuries, occasionally fatal in their character. Lightning not infrequently produces burns which may be quite extensive, or it may leave its victim suffering from hemi- plegia, paraplegia, paralysis of a single limb, or from amaui'osis, these af- fections being in such instances generally incurable, It sometimes hap- pens that a thunderbolt will tear and bui-n the clothing of an individual and overturn surrounding objects without doing him any personal harm, or ■with this disturbance of circumjacent bodies, he may be struck with sjTicope, fatal or only momentary. The remarkable escapes from serious injury which people who are struck by lightning occasionally enjoy are probably due to the great obstruction offered to the passage of the elec- trical current by the human skin in a dry condition, this resistance being calculated by Poore, the great English electrician, to be four times gi'eater than that offered by the entire length of the Atlantic cable. Death, when it occui-s from lightning stroke, may be owing to some ill- understood disturbance of the brain, to syncope, to asphyxia, or to the effect of the burns and wounds. Post-mortem examination discloses no characteristic lesions, although congestion of the heart, lungs, and brain are usually found, and the blood is ajDt to be uncoagulated. The great means of protecting houses and their inhabitants from the evil effects of a stroke of lightning is of com'se a well-constructed light- ning-rod. "When properly arranged a rod generally seciu'es persons or things situated within a circle the diameter of which is four times the height of the point of the rod, above the plane in which such objects are placed. The lightning-rod should be at least three-quarters of an inch thick, insulated by broad glass supports, Avell pointed at its upper end with platinum or gold, and ought to have its lower extremity embedded in moist earth to the depth of six or eight feet. It is found that large groups of men or animals seem to attract the lightning, and this is explained on the theory that the elimination of warm moisture from the lungs and skin of so many individuals produces an as- cending column of vapor which is liable to conduct the flash of electricity downward to the earth. Hay and grain stacks, manure heaps, etc., proba- bly have the same effect, and proximity to them should similarly be avoided during thunder-storms. Prof. Becquerel, from whose excellent " Traite d'Hygiene " much of the above has been condensed, gives Dr. Franklin's five rules for avoiding be- ing struck by hghtning, as follows : " 1. Always avoid the neighborhood of chimneys, because the soot which lines them is, like metals, a good con- ductor of electricity. 2. It is well, for the same reason, to keep at a dis- ttmce from metallic objects generally, and to lay aside gold or silver chains, ornaments, coins, etc., during a thunder-storm, 3. Never place yoiu'self under a lamp, a bronze, or other ornament of metal, a tree, or any high ob- ject whatsoever (when you have reason to fear a lightning stroke). 4. It is well to put between one's self and the earth a non-conducting substance, such as a thick plate of glass, for example. 5. The less the indi\idual touches the walls and the floor of a house the less he Ls exposed to being CLIMATOLOGY AND METEOEOLOGY. 457 struck by lightning. Hence the safest preservative means would be to oc- cupy during thunder-storms a hammock suspended by silken cords in the middle of a large apartment." This last suggestion would of course chiefly benefit timid hysterical females, to some of whom, however, it would fully repay all the trouble involved in putting it into practice by relieving that agonizing fear of being struck by lightning, which we may assure them is totally needless when they adopt such a sure precaution against the dangers of atmospheric electricity. Meteorology. From the time the great Dr. Johnson uttered his famous sarcasm upon observers of the weather, to wit : " A certain set of men pass their lives in observing the chaoges of the weather, and die at a good old age with the conviction that the weather is changeable," little has been accomplished in rendering us more truly weather-wise, until the splendid results attained by our own Signal Service Bureau gave a new impetus to the study of meteorology. In fact, the raison d'etre for an attempt to supj)lement the infor- mation furnished by Prof. Parkes' exhaustive work in the department of meteorology must chiefly be based upon the wonderful development that science has attained through the labors of our Signal Service. And in this respect few can dispute that not only the hygienists of America, but also those of the Old World, are under great obligations to our National Government, which, taking timely advantage of oi^portunities never before presented in the history of mankind, has. utilized them with marvellous success. These opportunities consist, of course, in the circumstances, first, that in our American Union there is a larger portion of the earth's surface in- habited by civilized man, now under the same jurisdiction, and controlled by one central authority, than in any antecedent epoch ; and, second, that by the most extended system of telegraphic communication ever organized, it has been possible, during the last decade, for the first time in the history of the world, to obtain instantaneous and simultaneous weather reports from an area of the earth's sui'face occupying the whole breadth of our continent, stretching from the thirtieth almost to the fiftieth parallel of latitude, and comprising more than three milhons of square miles. Over this vast section of country signal stations have been established, Trader the direction of the Weather Bureau, at least wherever j)racticable, and to such an extent as the yearly appropriation would permit. At these stations three observations are taken daily, at the same moment, the hours selected being 7 a.m., 3 p.m., and 11 p.m., Washington time. By this plan the changes fi'om hour to hour and day to day, as well as the effects which are produced by these alterations, are noted, and after being forwarded to the central office are reproduced in a permanent form upon the daily weather map which is transmitted as far as practicable over the country. Hence these daily maps may justly be entitled " the geography of our atmosphere." Without examining them we can no more secure an accu- rate conception of the general state of the weather than we could gain a correct idea of the real arrangement of seas, continents, and islands, as represented ujDon geographical maps, by walking a few miles along the coast or cKmbing over a range of mountains. The benefits from a sanitary point of view to physicians, and indeed to 458 AMERICAN APPENDIX TO PARKEs' HYGIENE. the community at large, of being enabled to accurately forecast the weather twenty-four or forty-eight hours in advance, are so gi-eat and so constantly serviceable that the suggestions we submit below are woiihy of minute attention and extensive trial. These clues will probably furnish more or less valuable (but of course not infaUible) daily giudes as to what sanitary precautions in regard to clothing should be instituted against heat, cold, or wet ; what days or what hours convalescents (especially children) may venture out into the open air; when is the best time for invalids to be subjected to any necessary re- moval, and at what peiiods neui'algic and rheumatic patients must exer- cise additional care in reference to exjDosui'e to atmospherical ^•icissitudes. Obviousl}' such items of information have — to the medical profession in an especial manner — a highly practical and sometimes an almost incalculable value. Any one by consulting the daily "Indications," or "Probabilities," in the pubhc prints can provide against the weather correctly on about three hundred days in each year, but by combining with the results of the Sig- nal Service investigations local observations upon barometers, winds, clouds, etc., it is possible to advance still further toward absolute jDre- cision, and eliminate nearly all the remaining errors in forecasting the weather, blunders which, if not thus corrected for individual localities, ai*e as mortifying as they are injurious to health. The general prognostications will doubtless become more and more reliable, with each added year of experience and skill, in drawing correct deductions fi-om the observed facts of Xatui'e, but on account of the apj^ar- ent impossibility, or at least, so far as Ave can now see, the iusui^erable dif- ficulty, of maintaining signal stations far out in the ocean off the Atlantic and Pacific coasts, there will probably long remain a belt of seaboai'd counti-y on each shore of our continent to the weather prognosis for which the word " probabihties " can only be api^Hed. This comparatively novel apj^hcation of the work of the Signal Service Office to the daily needs of j)ractical hygiene is assoredly one of the most, if not the most, substantial and valuable aids meteorology has ever contrib- uted to sanitaiy science, and we therefore make no apology to our readers for the foUowing explanation as to these investigations and their interest- ing results. From the majority of the 296 stations at which observations are taken thi'ee reports are transmitted daily, cousisting of the corrected barometer reading, record of temperature, dew-point, dii-ection of the wind in miles per hour since last telegraphic observation, upper clouds, lower clouds, and the reading of the maximum thermometer, the whole being sent in in the regular cipher words. The instruments fui-nished by the Service are directed to be read in the following order : first, bai'ometer ; second, exposed thermometer ; third, wet-bulb thermometer; fourth, anemometer; fifth, amenoscope ; sixth, rain-gauge. In all cases the maximum and minimum thermometers are to be read after the exposed thermometer. After the instruments have been read the character of the clouds and the state of the weather are to be noted. Each observer is ordered to note daily, at the exact moment of sunset, and for a time not to exceed thuiy minutes aftei-wai-d. the character of the westei'n sky and of the sunset, classif%ing and reporting them as " fair- weather sunsets," " doubtful sunsets," and " foul-weather sunsets." These tenns are used in theu- ordinary signification, but the obsei-vers of the CLIMATOLOGY AND METEOROLOGY. 459 Signal Office are fui'ther instructed : " It will be frequently noticed at the time of sunset tliat the western sky, while exhibiting generally the char- acteristics of a faii'-weather sunset, is tinged more or less and in different places with the colors yellow or gi-een. It is important that these colors should be carefully noted. In some instances the sunset will be found a decidedly yellow sunset, that being the predominant color of the western sky. The color green is rarely the predominant color, but portions of the western sky will sometimes markedly exhibit it.*' Records are to be kept at each office showing the non-verification or verification of these sunset predictions on the succeeding day. The instruments supphed to each first-class station of the Signal Ser- vice are : two mercurial barometers, two exposed thermometers, two wet- bulb thermometers, two maximum thermometers, two minimum thermom- eters, two anemometers and one self-registering attachment, one large and one small wind-vane, a rain-gauge and a clock. The instructions for suspending and reading the barometer are similar to those given in the body of this work, but the following suggestions are well worthy of reproduction here : "In moving a barometer even across a room it should be screwed up and carried with the cistern uppermost. For travelling it is provided with a wooden case. On steamboats or rail- roads it should be hung up in a stateroom or car, and the lower end firmly strapped to the side of the room or car, to prevent jarring. In wheeled vehicles (other than railway cars) (?) it should be carried by hand, supported by a strap over the shoulder, or held upright between the legs ; but it must not be allowed to rest on the floor of the carriage, as a sudden jolt might break the tube. If carried on horseback it should be strapped over the shoulders of the rider, where it is not likely to be in- jured, unless the animal (quadruped) is subject to a sudden change of gait. When I'equired for use it must be taken from its case, gently inverted, hung up, and unscrewed. While it has the cistern uppermost the tube is full — is one solid mass of metal and glass— and not easily injured ; but when hung up (in position) a sudden jolt might send a bubble of air into the vacuum at the upper end of the tube, and the instrument become use- less until repaired. Obsei'\'ers must never sidng the barometer or endeavor to force the mercury against the top of the tube without first screwing up the large adjusting screw at the base of the cistern. If the cistern should become du'ty it can be cleaned safely and without changing the zero of the instrument," for which directions are given. (See "Instructions to Ob- servers of the Signal Service," 1881, p. 18.) In regard to the exposed thermometer, it is ordered that it shall be hung in the regular instrument shelter, in such a way that it shall always be in the shade, and at least one foot from the wall of any building. " The readings must be made at all times, but especially in winter, through the panes of glass without raising the sash, when the shelter is built out from a window. When the shelter is built upon the roof great care must be exercised in making the readings, in order to prevent the instrument from being affected by the heat of the body or of the lantern at night. The ob- servation must be made as rapidly as is consistent with accuracy." It is required that the correctness of the zero-mark on the scale of every ther- mometer be tested by immersion in melting ice for half an hour, four times annually. Many points of detail in the manipulation of the maxima and minima thermometers given in the " Signal Service Instructions " are of interest to private observers, but want of space forbids their quotation. 460 AMERICAN APPENDIX TO PAEKES HYGIENE. The folio wiug in regard to the comparatively new branch of systematic observation of water temperatures is worthy of mention. The apparatus for this purpose consists of a small thermometer inclosed in a cylindrical metallic case. A portion of the case is hinged so as to be swung open when it is desired to read the thermometer. A valve at the bottom of the case admits the water as it sinks to the bottom of the river or lake, and falling into place when the case is drawn up prevents the water from escaping. "At stations provided with this thermometer one obsei'vation will be made, at 2 P.M. (Washington time) daily, of the exposed thermometer and the tem- peratui'e of the water at the surface and bottom of the lake, bay, or river upon which the station is located. The observer will select some conve- nient point on the shore (a wharf or pier when practicable) where a suffi- cient depth of water exists to give a positive difference between the surface and bottom temperatures, and will provide himself with enough strong cord to reach the bottom at the place selected. . . . Li making the observations the observer will first note the temperature of the air as shown by the exposed-air thermometer in the shelter ; then that of the surface-water by immersing the thermometer in the upper stratum of water, allowing it to remain long enough therein for the mercuiy to ac- quix'e the temperatui'e of the water ; and then lowering the c^dinder slowly to the bottom, will allow it to rest there long enough to fiU, after which it will be drawn quickly to the surface and the temperature shown by the thermometer carefidly noted." Since the temperatui'e of large bodies of water has an important effect upon that of the adjacent country, we may expect valuable contributions to both climatology and meteorology from this well-devised series of expe- riments. Observations on the humidity of the air are made with the wet- and dry- bulb thermometer, for computations from which extended and elaborate tables for a great variety of latitudes, elevations, and pressures are fur- nished in the "Instructions." The velocity of the wind is measured by the aid of an anemometer spe- cially manufactui'ed for the United States Signal Office. This instrument indicates tenths of a mile, and registers up to 990 miles. At some of the moi'e important stations an elaborate " electric self-recording anemometer attachment " is furnished. At such stations it is ordered that the hourly velocity of the wind be deduced "from the record of the fifteen minutes (multiplied by four) immediately preceding the time of observation. Li case the cups are moving at the moment of observation, and the anemom- eter has not closed the circuit during the said fifteen minutes but during the preceding horn-, the number of miles will be taken from the whole hour preceding." The method of measuring the rainfall adopted by the Signal Service Bureau differs from Dr. Parkes' plan, and as it enables an observer to se- cure greater accuracy we transcribe it in detail : " The rain-gauge must be placed wherever practicable, with the top of the funnel-shaped collector twelve inches above the surface of the ground, firmly fixed in a vertical position and protected from interference. It must be examined at the time of mak- ing each of the three telegraphic observations, the amount of water, includ- ing fog or dew, it contains carefully measui-ed by means of the graduated rod sent with each gauge, and then emptied and returned to its proper position. When a situation at the level of the ground, with a sufficiently clear exposui-e, cannot be found, the gauge will be j^laced on the top of the instrument room, or roof of the building occupied by the observer, CLIMATOLOGY AISTD METEOEOLOGT. 461 who will measure the height above the ground and report it to the Signal Office. The measuring' rod is graduated in inches and tenths of inches, and the proportion between the cylinder and funnel is as one to ten, so that ten inches upon the rod correspond -with one inch of actual rainfall, one inch to one-tenth of rain, etc." Snow is directed to be melted and reported as rain, the fact of its being melted snow being carefully noted. When from any cause the snow cannot be melted its depth wiU be meas- ured, and ten inches of snow reported as one inch of rainfall, the fact of its being so approximated being also noted. In regard to the appearance of the sky, observers are instructed to re- port the weather as dear when the sky is three-tenths, or less than three- tenths, covered with clouds ; fair when the sky is from four-tenths to seven-tenths (inclusive) covered ; and cloudy when the sky is more than seven-tenths covered. The ingenious system of forwarding detailed reports at a minimum expense to the Government by using cipher words (such as "hub," which means " a thunder-storm with light rain, wind blowing from the north," or "rage," which indicates "rainfall since last report has been nineteen one-hundredths of an inch") is no doubt more or less famihar to our readers. Besides the causes ordinarily enumerated as producing the atmospheric vicissitudes upon our globe and referred to in the body of this work, such as the motion of the earth upon its axis and the obliquity of that axis to the plane of the ecliptic, we have another fact, the importance of which has only been recognized within the last fev/ years, and that is the move- ment of areas of low barometer across the surface of the earth, the conse- quences of depressions or furrows in the surface of our atmosphere. These areas of low barometer have a general tendency to move over us from west to east. As a rule, therefore, when the area of low barometer is west of us we may expect a storm, and although this storm may pass by us, either nearer to or further from the North Pole than the spot we occupy, without causing our neighborhood an}' great disturbance, it is almost certain to cross our meridian at some point. After that transition has been effected the winds, following as they do the course of such a depression in our atmosphere, will blow over us in an easterly direction, varying to the northeast or to the southeast, perhaps, according as the storm-centre hap- pens to be travelling above or below our parallel of latitude. The clouds will of course be blown along from the west by the winds which are hurry- ing across toward the area of low barometer, which has now progressed to the eastward of our station, and after a few hours or a day, depending upon the magnitude of the cloud accumulation, we will see the blue sky again, and know that this particular storm is over. Although we usually find that it takes three or four days for another area of low barometer to reach our indi-^idual locality, we must remember that there is no absolute certainty about the distance between these centres of storms. Another low-barometer area may advance upon us in one or two days, or, on the other hand, the one next following may progress so slowly, or may be diverted from its track in such a way that it may not come to us for five or six days, and when it does arrive, attack us from another and totally different dii'ection. The path of an area of low barometer across the country has been rather fancifully yet aptly compared to the track of an immense water- cart, the centre of which is of course the line of most violent storm. The average rate of such a storm-centre is, according to Prof. Loomis, 26 miles 462 AMERICAN APPENDIX TO PARKEs' HYGIENE. per hour, the mean velocity in summer being 21 miles and in winter 30 miles, but the rapidity with Avhich it moves is very variable, and may attain to 50 miles an hoiu- or 1,200 miles in the twenty-foui\ Winds, as a general nolo, tend toward the area of low barometer as a centre, but ranges of mountains, valleys, extensive forests, and so forth, often produce local variations in the dii-ection of these converging cun-ents of air. In violent storms the winds tend to circulate about the storm- centre also in a direction contrai-y to the motion of the hands of a watch. From this it will be at once perceived that when an area of low barometer happens to be crossing om- continent at its uj)per part, the winds felt in places along its centre will be in a general way from the south, and vice versa. That is to say, if at any time an area of low barometer is passing through New York and New England, the winds in Philadelj^hia will be toward it, and for twelve hours, perhaps, from the southeast, then for an- other twelve hours nearly south, afterwai'd veering round still further until a southwest or finally a westerly wind brings us clear weather. On the other hand, if a similar storm-centre is travelling through Virginia and Maryland, the winds in Philadelphia will be northerly, and generally cooler. The apparent exceptions to the rule of north winds being cooler and south winds warmer are obviously due to large volumes of warm air or of cold air, respectively, having previously been blown to the north or south of a particular position. Although the general direction of movement of the areas of low barom- eter seems to be aroiind the earth, in the direction of our planet's motion — that is, toward the apparently rising sun — their course may sometimes vary very widely from this, and, as shown by the maps, they may occasionally travel almost due north for three or four days, during which time they traverse a distance perhaps of 1,000 or 1,500 miles before they resume their normal easterly tendency. Since, therefore, the storm-centre is in the neighborhood of the area of low barometer, there is seldom or never a true northeast storm, much as we hear people talk about "northeasters." A northeast wind with rain in any particular locality results usually from an area of low barometer trav- elling eastwardly a few hundred miles south of that position. By making use of the daily predictions, or still better of the daily weather maps where they are accessible, as general guides, and correcting these for individual localities by a study of the local w4nds, clouds, and sunsets, and especially by obsendng a mercurial or aneroid barometer, noting its fall as an indication of the approach of an oncoming area of low barometer toward the exact spot on which we live, and also especially ob- serving when and how rapidly it rises as a token that the low area (which is the storm-centre) has passed by us, it is, I believe, possible to attain an accuracy in predicting the weather which appears to unscientific persons almost miraculous, and secures for us as practical Hygienists immense ad- Tantages, both to our own health and to that of our patients. YEXTILATIOX AXD WARMING. By D. F. LIXCOLX, M.D. The subjects of ventilation and heating have to be studied, in America, from a point of view somewhat differing from that taken in England. As re- gards the requii'ements of cubic space and supply of fresh ail', there is and can be no diiference. But in certain respects, for example as regards the standard of temperature to be 'maintained, "we find ourselves unable to adopt Enghsh rules, and the English would be equally unwilling to accejDt ours. The severity of our seasons, too, has f orcecl us to make use of steam and stoves to a much greater extent than is usual in England, while the old-fashioned method of warming by the fireplace has fallen too much into disuse among us. Hot-air FniXACES. "When the inmates of a private house seek comfort, their first thought of improvement is in the direction of increased warmth. The halls are to be made as wami as the rooms ; the sleeping-rooms are to made comfori- able for occupancy by day ; and to effect this purpose, a furnace in the ceilar is the most feasible means, if the house be of moderate size. A house of more than three large rooms on the ground floor, however, with one or two stories of rooms above, cannot be properly heated by one fur- nace (Philbrick). However powerful the appai-atus, it is unsafe to tiy to conduct heated air more than six feet ia a horizontal dii-ection fi'om the fur- nace. Neither should we attempt to conduct a hot-air flue against the direction of the prevailing wind, in exjjosed situations. If a windwai-d room cannot be wanned, because the fui'nace air refuses to enter it, the remedy is to open a chimney flue in the room ; it may be necessaiy to light a fire to increase the draught of the chimney. Aii' cannot be forced into a tightly closed room : a failure to warm such a room is remedied by opening a discharge for the air from it. Flues supplying different rooms sometimes "draw against each other," as chimneys will; this is hkely to occur when the supply from below is not sufiScient for all, either becaiise the air-box, or inlet of fi-esh air to the furnace, is too small, or because after it has been closed in a high wind some one has neglected to open it. A most eccentric effect is sometimes produced when a ciuTent of hot air passes out of the orifice for supplpng fresh air to the fui-nace, while the air is sucked downward fi'om the rooms. The best way to heat a house at moderate expense seems to be by a combination of hot-air furnace in the cellar, and oj^en fii'eplaces in the rooms. The false fireplaces, with dummy mantels, which take the place of the true in cheap houses, violate not only the principles of taste, but the laws of ventilation. An open fireplace in a closed room is very useful, not YoL. II.— 30 466 AMERICAN AFPENPIX TO PARKEs' HYGIENE. merely as a means of warmth, nor even as combining warmth and ventila- tion ; it helps greatly in giving equality of temperatm-e, by drawing the furnace air down to its owTi level. This it does, even when there is no fire actually burning in it. Fresh air, in coming into a furnace, must not be brought through underground ducts, as a rule, unless we can be sure of the purity of the soil. It is necessary to choose a point for the intake somewhat above the level of the ground. In city houses, one may sometimes see alternate half- bricks removed checker- wise from the walls of the outer vestibule, outside of the door, which is a safe place for taking air. A grating, to protect from vermin ; a slide, to regulate amount ; and sometimes a sifter of cloth, to keep out dust, are necessary. To obviate the inconveniences arising from wind-pressure, it is well to arrange inlets on opposite sides of the house. For large buildings, reservoirs may be planned, in which the pressure may be kept equal by valves at inlets. These remarks apply to inlets for other apparatus than furnaces. It is well to use a larger size than is considered absolutely necessary. There is economy in running at moderate rates. A reserve of power for the coldest weather should be on hand. The general fault of hot-air fur- naces is that they deliver the air too hot ; and this must be obviated by making them much larger, so that they shall not have to be raised to a red heat, and may at the same time furnish a larger volume of aii*. Much is said of the desirability of substituting \vi-ought for cast iron. The former possesses the advantages of superior tightness at joints, but is said to wear out sooner. The passage of gases through joints is certainly undesirable. Furnaces built of soapstone are said to be very tight ; they occupy a great deal of space, but are praised for the qviality of their air. Automatic dampers or regulators of the lower air-draught are appli- cable to furnaces for heating air, water, or steam. Dampers in the smoke- flues are undesmable ; the joints should be so good that opening and shut- ting of the lower door is sufficient. ' Contamination of air by the escape of carbonic oxide has been said to be a source of esj^ecial danger in the case of cast-iron stoves and fiu-naces (Deville et Troost). Eecent experiments by Professor Ira Remsen (1881) seem to show that these views should be modified. " The hypothesis is per- haps justifiable that carbonic oxide is present in the air of rooms heated by cast-iron stoves and hot-air furnaces, but not that it is present in quantities as great as 0.04 per cent. ; and it remains to be shown whether such minute quantities of the gas, if present, can act injuriously on the health of those who breathe it." In short, Eemsen was unable to detect the smallest quantity appreciable by the Vogel-Hempel process in air which had been passed over white-hot cast-ii'on stoves. HOT-WATEK A>fD OTHER APPABATUS. Hot-water apparatus is more costly than a simple furnace, and takes room. It is comparatively little used here. It is highly praised by Dr. Billings, as applied to the heating of the Barnes Hospital, near Washing- ton. The defect which he notices at that hospital is an inabihty to raise or lower the temperature quickly, which ought to be remedied by some simple plan for partially deflecting the incoming air (Figs. lOG, 107). The same arrangement ought to be applied to steam heaters, although some have been successful in arranging mtdtiple coils, which can be shut off in sections for the pvu-pose of lowering temperature. VENTILATIO:X AXD WARMING-. 467 -i ^ The advantage possessed by both hot-water and steam over hot-aii- fui- naces consists in the power of transferring heat to any desu-ed point. Both ought to be combined with aiTangements for ventilation, as, for example, in the sketch of a window-radiator (Fig. 104). The extent to which heating by steam is carried is illustrated by the State Lunatic Asylum at Indianapolis, which has a total volume of rooms — 2,574,084 cubic feet, warmed by 34,100 square feet of radiating surface (two-thii'ds indirect). Steam is successfully supjDlied by comjDanies in New York to private houses through street mains, like gas. Technical improvements in the art of steam-fitting have been made in great num- bers by American mechanics. Steam heat, like furnace heat, is apt to be exces- sive in mild weather. Shutting off steam is not always adapted to the circumstances. If a large building is to be wai'med by the- aid of propulsion, the method may be suggested which is believed to have been first proposed by Major-General M. C. Meigs, U, S. A., for the United States Capitol at Washington, in 1856. He placed a large auxiliary warming coil at the entrance of the main supply-flue that leads fi-om the fire into the building. By shutting o£f parts of this coil and by the use of by-passages and regulating shutters or dampers, the air entering the main supply-flue to the building can at all times be warmed to a uniform temjoerature of, say, 50^ F. Air at this temperatiu'e can be safely conducted to special coil-boxes in any j)art of a building, where it receives any desii'ed addition of heat, and enters the rooms at from 50^ to 120° F., as may be needed. This arrangement is eco- nomical of steam-pipe. Fig. 104.— Inlet for Fresh Air under Window. (Gonge. ) VE>'TnLATi>'G Stoves akd Geates. The princijole of supplying fresh warmed air by fireplaces and stoves in the room has been applied in several ways in the United States. The "Galton " stove seems not to be manufactured here ; its place is taken by ^ the Fh'eplace Heater, and the Fire on the Hearth, the Dimmick Heater, and the Jackson Fireplace. A series of experiments by J. P. Putnam ' gave the following resvilts as regards the percentage of heat rendered available for wanning a room. By an ordinary fireplace, six per cent, of total heat generated ; Fireplace Heater, thirteen per cent, with wood, twenty j)er cent, with coal ; Dimmick Heater, eighteen per cent, with wood, twenty-five per cent, with coal ; Jackson Fireplace, wood, twenty-seven per cent. An improved aiTange- ment of flues would add five j)er cent, to these figures. The Fire on the Hearth is mentioned by Youmans as supplying, with a small-sized stove, over ten thousand cubic feet of air at 160" F. in an hour, the outside temperature being 46° ; it is a movable cast-iron stove, wliile the others are set in the chimney. It is to be hoped that the " ventilating fireplaces " will be lai'gely intro- duced into the better class of houses. Fig. 105.— Stove Trith Fresh- air Supply. ' The Open Fireplace in all Ages, by J. P. Putnam. J. R. Osgood & Co., 1881. 468 AMERICAN APPENDIX TO PARKEs' HYGIENE. The principle of inti'oducing fresh air can be applied in a cheap and effective way by running a fine from under the stove to and thi'ough the house-Avall, as represented in Fig. 105, where the stove is seen surrounded by a cylinder of sheet-iron set on the floor. The amount of fresh aii' thus introduced is abundant for domestic jDuriDOses, and not insignificant (though greatly inadequate) in the case of schools. This principle is adopted in the Belgian school stove exhibited at Philadelphia, 1876. It wiU not suc- ceed if the room is tight, without an outlet ; for the ordinary stove dis- charges by its flue barely as much ah' as is required for combustion. Temperature and Moisture. The American " fondness for over-heated rooms " has often been re- marked. No doubt a part of this fondness is merely a bad habit, and is both the cause and the index of delicacy of physicjue. But something must also, in aU probability, be ascribed to the climate, which is of a troj)i- cal nature for sevend months in the year. Those accustomed to a daily heat of 70° to 100° in summer, may jDerhaps become less capable of resist- ing cold in winter. It is also a fact that most parts of our country possess a drier atmosphei'e than that of England, and Western Europe, and that moisture acts as a protective against the loss of bodily heat ; hence, an American room in winter, with a dry hot air (70° F.), may appear to its oc- cupants no warmer than an English room with a moister air at 65° F., or even at a lower point. The change which has occui'red in the habits of Europeans and their descendants in America, has been made the subject of much remark. It is within the knowledge of the writer, however, that families have been brought up in perfect health, and adult famiUes are now living, in temperatui-es much lower than those usually thought needful. A friend of the writer's keeps his house at 60° F., has his children taught in a little private school at his own house, and in summer carries them away to a cool seaside resort ; but few can carry out such a plan. The aged prefer 80° F. The mildness of the Enghsh climate permits the use of open grates, which with us are necessarily rej)laced by the more powerful apparatus, stoves and furnaces and steam-heaters. Hence we lose the effect of lumi- nous heat, which is probably greater in its sensible action than a (measured) equal heat, without Hght, as furnished by stoves. Fui-thermore, the Eng- lish ojoen fire is a ventilating agent, sufficient for household purposes ; while the closed stove in common use among us, economical as it is of heat, gives very little ventilation. Doubtless the discomfort felt in close rooms thus heated is partly due to a mere want of ventilation. Another source of discomfort is the escape of gas (sulphurous fumes) through leaks in ap- paratus ; and another, the mere over-heating of air, by contact wdth very hot iron, which seems to affect its sensible qualities in a disagreeable way. Heaters — whether furnaces, stoves, or coils of steam or hot water — ought to yield air of a moderate temperature, ranging from 90° to 120° F., accord- ing to the weather. They are commonly made too small, and have to be " run " too fast ; this is especially true of stoves and furnaces. Low-pressure steam (it is said) usually gives heated air at from 90° to 110° F. ; hot-air furnaces, above 140° F. ; hot-water coils, any temperature desired. Such are the common statements ; but an ordinary hot-air furnace in the writer's house is now giving air at 124" F., and another in a neighbor's house at 94° F., the outer air being at 34° F. As regards the supplying of mois^ture by artificial evaporation, much YEXTILATIOX AXD WAE:inXG. 4.69 may be said on iDoth sides. Some persons seem to require a moist air. A fine jet of ^vater thi'ovm into heated air gives a pleasant quality ; it cools it, also. On the other hand, much of the complaint of •'•' diied-up " air can he remedied by ventilation, as ah'eady stated ; and in. hospitals, ^vhere a hberal supply is afforded, a very low proportion of moistui'e is compatible vdih a very pleasant eftect upon the senses, and good hygienic results. The requirement of seventy per cent, of satui-ation is inapplicable to this chmate. In illustration of the difference between the American and the English standards of temperatui-e and humidity may be cited the obseiwations (1) of Sui'geon D. L. Huntington, at the Barnes Hospital, Washington, and (2) those of Dr. Cowles, at the Boston City Hospital — places presenting very considerable differences in chmate. 1. Fii'st week in December, 1877. — Avei-age external temperature, 38-^° ; average temperature of wards, half way to ceiling, fi'om 71^ to 76' F. ; aver- age relative humidity of house, fi'om 44 to 59 ; of outer air, 74. 2. Week ending December 10, 1878. — Average external temperatui-e, 32' F. ; humidity, 76 ; average temperatui-e of air at head of beds in new ward, 68f ^ F. ; average relative humidity of ward, 29:^. These data represent the degi-ee of diyness which is not simply tolerated in our hospitals, but is habitual, and is consistent with a " peculiar feeling of freshness and purity perceived by those who enter the room." The uncomfortable sensations felt in some warm, dry rooms are ascribed by the late Eobert Briggs to absence of moistui-e ; but Billings and Cowles agree that they are caused by an insufficient supply of fresh air. The diyness is unavoidable unless water is evaporated in large amounts ; and is much more marked in really cold weather, for instance, when the ther- mometer ranges from —20^ to -r20" F. With these statements compai'e some in the present work. For exam- ple, the agreement for ventilating the Laiiboisiere Hospital stated the tem- perature required as 15' C, or 59" F. ; and the memorandum issued by the Medical Department of the Pri%y Council in 1872, for the government of hosijitals in towns, suggests "warming in "uinter to 60" F." (p. 358). As a provisional stand ai'd of humidity, De Chaumont's 73 per cent, is recom- mended (p. 153). The advanced thought of this countiy upon the subject of ventilation will coincide, doubtless, in the statement that '"'the amount of supply for audience halls occupied for sessions not exceeding two or thi-ee hours' duration should in no case be less than 30 cubic feet of aii' per minute through the regular flues of supply, and in legislative buildings the apjDar- atus should be such that at least 45 cubic feet of air per person per minute can be fuimished, Avith a possibihty of increasing it to 60 feet per minute when desired " ( Billings j, Special BrrLDiyos, etc. One of the most satisfactoiy small hospitals, in point of heating and ventilation, is the Barnes Hospital at the Old Soldiers' Home, near Wash- ington. This con tarns four wards, in two stories ; each ward has twelve beds, and an allowance of 1,500 cubic feet per bed. The wards are heated by coils of hot water, j)laced in air-chambers in the basement at the walls. The flow of water to each coil can be regulated by a cock ; but it rec[uires an hour for a coil to cool down, and an arrangement for more speedy change is to be desired. (See Figs. 105 and 106. ) The fresh-air flues are of 470 AMERICAN APPENDIX TO PAIIKES HYGIENE. terra-cotta pipe built into the walls. The foul-air flues are Hned with tin, and are cleaueLl daily ; there are two for each ward, one above the ceiling and one below the floor, at the middle ; each has five inlets ; and the patients being under military discipline tlie inlets are not defiled as they would be likely to be in a civil hospital. These ducts lead to an aspirator chimney, heated b}' the boiler flues and kitch- en flues, or by a special tire when the boiler is not in operation in moderate weather. The mean velocity of the uj^ward current of air is 180 feet per minute ; with good fires in the gi-ates at the base the highest recorded veloci- ty was 700 feet. A fan is used to force cool air thi'ough the heating flues in moderate weather, when it is unsafe to open windows. In an experiment, all the outlets to a certain ward having been closed for thirty-five min- utes, the air was found to contain 11.23 per 10,000 of CO, which was reduced to 3.75 by ten minutes' use of the fan. Examj^les of a t^^De of construction which oiigiuated in the exigencies of militaiy service ai'e found in the new detached wards of the Boston hospitals. The " WaiTen " ward (Mas- sachusetts General Hospital) consists of a single rooin 41 feet square, 16 feet high at the walls, and 22^ feet in the middle. A stack of brick flues occupies the centre ; each face of the stack has an oj)en grate with fire. Further ventilatiou is insured by twelve openings in the floor, around the stack, at a distance of 5 feet, and leading to it by sub-floor ducts. There is also a large roof- ventilator, and the upper segment of each window can be tilted inward when desired. The supply of fresh air enters by foui' inlets in the floor, half-way between the stack and the corners of the room, having a combined section of 8 square feet. At a velocity of 5 feet, the supply (for twenty beds) would equal 2 feet per second and patient — say, 7,200 cubic feet per hour and patient. This air is wai'med by steam in a base- ment. The " Bigelow " pa\'ilion (same hosi^ital) is a long stinacture of brick, with double Avails of brick, j^ainted to exclude dampness. A hall, 8 feet wide and 24 feet high, runs lengthwise through the middle. There are six- teen rooms for patients, with one bed each, besides accessory rooms. Each room has its fireplace, with additional means for extracting air at top and bottom, so as to change the air once in ten minutes. Fresh air enters near the ceiling, having been warmed, something in the Galton method, by contact with the flue of the fireplace. These wards are one story in height, are not in contact with any other wards, and can be isolated when desii-ed. The latest development of this type is found in the new (unfinished) Johns Hopkins Hospital, in Balti- more, where each ward is practically a separiite small hospital, and it is impossible to pass from one ward to another, or from the corridor which connects the basements, A^ithout going into the open air. Ventilation is effected by asjDiration, by a separate chimney for each ward. There is a single duct down the middle of the ward, under the floor, with one branch to each bed, opening under the foot of the beds. Another duct is placed Fio. 106. — Apparatus for rapidly changing Temperature of incoming Air. (Johns Hopkins Hospital.) A. Inlet: valve in p isition to arlmit a little un- warraed air. /f. Slide-valve. 2>, Valve. E, Register, air entering ward. VENTILATIOlSr AND WAKMING. 471 Fig. 107.— Massachusetts General Hospital. A, House-wall. B, Valve- openinEr through wall. C, Valve for regulating heat, in position to give the greate.'-t heat. D, Handles for work- ing B and C, placed close to register in ward. above the ceiling, communicating with the ward by five openings. The former will be used for winter ventilation, the latter in summer. The ducts are of galvanized iron, or lined with that material to prevent leak- age. Each ward will have a small propelling fan, designed to force air through the heaters and flush the ward two or three times a day. The heaters are placed in the basement of each ward, along the outer walls ; they consist of steam-coils. The diagram (Tig. 107) shows that the supply of fresh air is taken from out-doors ; but the air of the basement (which is used for no other purj)ose) can in cold weather be drawn upon. The " base- ment" is not a "ceUar," being wholly above gTound. The Boston City Hospital (375 beds), fin- ished in 1864, on the pavilion plan, was at first supplied with air forced through underground brick ducts, exposed to pollution. The system for the original pavilions has since been entire- ly changed ; propulsion is abandoned, and local steam-coils are placed in air-chambers under the points to be supj)lied. The beneficial effect upon the health of surgical cases was shown by the fact that the rate of deaths from com- pound fractures fell from forty-one to twenty per cent. ; after amputations, from forty-four to thirteen per cent. Certain observations made in the new one-story wards have already been mentioned. These wards are. 94 x 2,6^ feet in the clear, and with curved roofs averaging 18 feet 5 inches in height. Each has twenty-eight beds, giving 88|- square feet of floor-space, and 1,629 cubic feet of air-space to each bed. Air is introduced as in the Johns Hopkins wards, and is re- moved through ridgepole ventilators without traction. A general uniform upward movement is observed, with little tendency to areas of stagnation. Analysis gave the following results: mean carbonic acid, 0.0505 per cent. ; that of outside air, 0.0325 ; air-supply per head per hour, 3,333 cubic feet; respiratory impurity, 0.018 per cent. The accompanying diagram (Fig. 108) gives the curve of the central axis of the hot air currents entering the room from opposite sides. It passes through points of greatest velocity, ascertained by measurements by ane- mometer, taken at intervals of a foot in perpendiculars erected on the points A, B, C, D, D, C, B, A, the latter being three feet apart. The draw- ing is to scale, and shows that the horizontal impulse is nearly expended at D, about seven feet from the floor and nine feet in fi'om the walls. Above the height of twelve feet the general upward movement becomes sluggish, to be much quickened near the point of exit E. It is thought that the air might leave the room more quickly, with less risk of readmixture, if the ceiling were lowered to the height of at most fourteen feet. The New York Hospital has four stories. There is, one window to each bed. The foul air flues are contained in the external piers, which are lined with hollow brick to prevent the escape of heat. The openings for discharging air from the wards are, partly near the ceiling, j)artly near- the floor, and one under the middle of each bed. Hot air is conveyed by cast- iron tubes running through the middle of these flues, fitted so as to be air- tight ; but this collocation of foul and fresh air tubes seems questionable. 472 AMERICAN APPENDIX TO PARKES HYGIENE. There is the peculiarity of two fans — one for propulsion and one for ex- haust. The average air-supply is stated at 2,400 cub. ft. per bed and hour. The hall of the House of Representatives, at Washington, is supplied with air taken from a distant high tower, and passing through a tunnel. Forced in by fan-power, it enters through apertures ha\dng a total sectional area of 300 square feet on the floor and 125 in the galleries, and passes out through the ceiling. A fan was fomierly so placed as to accelerate the exit, but the result was to create a partial vacuum in the hall, with a strong ten- FlG. 108.— City Hospital, Boston. Floor of Ward, 26 feet across. (Scale, 8 feet to the inch.) dency of the air in the corridors to enter through the doors, bringing dis- agreeable odors. This fan is now employed in aspirating from the cor- ridors, with satisfactory results. An analysis made after three and a half hours of session, 550 persons being present, showed a proportion of 7.G7 parts of CO, per 10,000. The Madison Square Theatre, in New York City, is one of the best ven- tilated buildings of its class. The air is taken in at a tower above the roof ; it is sifted thi-ough a conical bag of cheese-cloth, forty feet long, sus- pended in the tower ; it is heated by steam in winter, and cooled in sum- mer by passing over ice, four tons being required for each evening. One fan, at the foot of the tower, forces the air in ; another, on the roof, ex- hausts it. The doors and windows are kept closed. Heating, cooling, and distributing take place in the cellar. The air is introduced by pipes, run- ning under the risers ; an opening in the riser, at each seat, discharges a forward current, with a velocity of two and a half feet per second. Other jets enter at the front of the footlights, and below the balconies. The exits are chiefly under the balconies, so that there is a general movement away from the stage. It is thought that the acoustic effect is improved by this circumstance. The footlights are ventilated into a horizontal duct, in which the gas-pipe is laid, thus heating the gas before it is burned. The great dome light, and the other gas-lights, are enclosed in glass, and ven- VENTILATION AND WAKMING. 473 tilated upward. The supply is a, 500 cubic feet per hour and head ; the theatre seats 650 persous. The New York State Reformatory at Elmira contains 500 cells. A block of cells resembles a huge one-story shed, through the middle of which runs a pile of boxes, two deep and three high. The boxes repre- sent cells. The free space near the outside walls is sujDplied with warm air from below ; this freely enters at the grated doors of cells ; the foul air passes out by two orifices in the rear wall of each cell, one of which is so arranged as to ventilate the niche for the night-pail. The foul air ducts are 4x4 inches, and terminate in heated chambers and asj)irating chimneys in the roof. The inta,ke of fresh air is in a tower, and a fan is used to force the current. One of the best ventilated churches in the United States is said to be the Presb}i;erian Chui-ch in Fifth Avenue, New York (Dr. Hall's), which has a capacity of seating 2,000. The intake is by a tower 100 feet high, and the supply is from 10,000 to 15,000 cubic feet per minute, depending on the speed of the fan. At the lower rate of speed, and with a congrega- tion of 1,400, the result, after a service of an hour and a half, was a pro- portion of 12|- parts carbonic acid per 10,000, The fan, however, is con- tinued in operation during the interval of morning and afternoon service, thus thoroughly flushing out the room. The entire basement story forms an air-chamber, from which the warmed air passes through openings in the risers of the stationary foot-benches of each pew, the supply to each pew being under the control of its occupants. The air-supply is warmed, first, by 4,410 feet of steam-pipe in the duct, just after passing the fan ; second, by 9,000 feet of pipe fixed to the ceiling of the basement. The latter pipe aids greatly in warming the floor. A plan of combined heating and ventilation has become popular in the Lake States and Canada, under the name of the Ruttan system. The proprietors profess to produce remarkable heating effects by means of large tubular casi^iron fumaq^s, which are said to weigh, in general, four times as much as " ordinary'' stoves " (their largest weighing 5 tons). Owing to their size, they are able to warm large amounts of au- to a point not above 90° F. The foul air is extracted by openings in the base-boards, close to the floor, and thence passes under the floor to an exhaust-shaft heated by an iron smoke-flue. It is said that the air is changed once in half an hour or less. The principle of induction of au'-currents is apphed in Gouge's ventila- tor. This consists of a small metal tube, heated by a gas-jet, with an open end near the floor ; at a sudden enlargement, near the ceiling, a second opening is made, into which au- is drawn by the inductive force of a current already estabhshed. If the tube passes through another stoiy, other open- ings and enlargements are made. The principle of induction is the same that is used in the water-blasts, for ventilating mines. Where funds are scanty, a very cheap and fit plan is to run plain straight tin pipes from some point near the floor to a point above the roof, capping them to prevent rain and wind from entering. . There must be no bends, and no exposure to cold until the roof is passed. While the house is warmed, the current in such pipes is constant. "Aspiration from above" is used in many schools and institutions. Pipes are run upward from the rooms to one large tin-lined box in the garret, which is heated by steam, and discharges through the roof. The plan is adapted to old buildings without flues, pro^ided the pipes run straight. For dormitories, it may serve a very excellent pvurpose. 474 The small space allowed in raili-oad cars makes it extremely hard to ven- tilate them. An ordinary passenger car gives about 33 cubic feet -per man ; a smoking-cai' 50 feet. Nichols' results of analyses of ah' were correspond- ingly imfavorable, viz. : For smoking-cars, from 12.7 to 36.9 of CO^ per 10,000 ; average 22.8. For jDassenger cars, lowest 17.4, highest 36.7, average 23.2. Some cars are furnished with valve-boards at the ends, on which a no- tice is painted to show their use. lu othei*s, the windows are aiTanged so that they can be raised only a couj^le of inches — in the hope of protecting passengers against indiscriminate ventilation. In others, a positive venti- lation is secured by valves in the monitor roof, which are regulated by the conductor with a stick. The elevated railroads in New York wann their cars by steam pipes under the seats ; each car is connected by rubber tubes with its neighbors, and the whole system is constantly supplied with dry steam fi'om the en- gine, the condensed water being blown through to the rear of the train and there discharged by a vent. This does not secure ventilation. A supply of fresh warmed air can be furnished by making use of the motion of the car to force air over the heater. The heater is inclosed in a fresh-air box at one end of the cai', from which the heated air is led in wooden pipes to any part where the supply is wanted. The supply neces- sai'ily ceases when the car stops ; but usually the need for ventilation also ceases at the same time. A combination of hot- water pipes cu'culating around the base, and no- pressure, open steam-pipes at a high level, distributes the heat effectively. The pi'oblem of cooling the air of a sick-room in connection with venti- lation was illustrated during the illness of the late President Gai'lield. An outside temperatiu-e of from 80"" to 100^ F. was to be exj)ected. It was computed that from thi-ee to foiu- tons of ice daily (?) would be required in order, by its melting, to cool the necessary- amount of air {twelve thousand cubic feet per hour). Air was forced by an engina thi'ough an ice-box of the capacity of six tons ; on leaving this the air traversed another appa- ratus consisting of a box 6^ feet long and 27 inches square, provided with a large number of cotton screens, kept constantly wet by the water which dripped from the ice ; thence it was taken to the President's room by a tin tube. To prevent the noise of the engine reaching the room, a tube of canvas was aftei-ward substituted, when the sound entirely ceased. A l-l-inch blower being foimd insufficient, one of 36 inches was substituted. The temperature of the enteiing au* was found to be 55.1°, while that of the oj)en air was 84.6''. The process, however expensive, was satisfactory in accomplishiug the object desired. In the Fifth Avenue Presb}i:erian Chvu'ch of New York City the au' is cooled in the inlet shaft by spray from a perforated pipe. ^Yhen the tem- perature of the water was 69^, the air passing through the spray was cooled fi'om 77" to 73' ; by the use of ice the temperature has been lowered as much as six degrees. General M. C. Meigs has experimented with window-sashes containing double thickness of glass, for the pui-pose of checking the loss of heat by radiation and otherArise. A thermometer placed between the panes indi- cates a temperatui'e veiy nearly half-way between that outside and that within the room. EEMOVAL OF HOUSE-WASTE. By EDWAED S. PHTLBEICK, M.A. S.O.E., Boston, Mass. The Need of Pkoiipt Removal. The opinion of all intelligent persons is unanimous upon this question. Nevertheless the practice of most communities is very far behind the theory. It needs no argument to convince us that it is not proper or con- ducive to health to allow fecal matter or organic waste in any form to ac- cumulate, either in the interior of our dwelHngs, or in their immediate vicinity. Nature has given us a sense which is disgusted by siTch practices, and it requires no high degree of refinement to condemn them from the tribunal of good taste alone, without recoui'se to hygienic laws or local statistics. It seems strange that, with such unanimity of opinion, no better devices should be used by the majority of our people than the old-fashioned privy with its vault, or the more modern water-closet with its cesspool. The former is often located within the house-walls, or under a roof connected with the house, while the latter is rarely far from the dwelling, even when the house-lot is large enough to allow it to be so. This firmly rooted custom probably originated in the popular belief in certain supposed powers of the soil for purification and disinfection. But this belief is founded on a fallacy which we think it quite time to expose. Soil is capable of such action only to a verj^ hmited extent, depending mostly for its efficiency upon the oxygen in the air which it holds in its pores, or upon the plant roots which may find their way into it. When once the soil has become saturated with filth around a vault or cessjDOol, its purifying power ceases and can never be resumed, unless air or the roots of plants can penetrate the mass. It is evident that these agents have a very hmited access to the soil around a large majority of the cesspools and vaults now in use. In cities or towns, very little if any such absorption by roots, or thorough decomposition by air in the pores of the soil, can be possible The inevitable result, then, is an accumulation of a dangerous, putre- scent mass, which would not be tolerated if it happened to be within the reach of our senses. It is certainly not the part of intelligence or wisdom to ignore these facts simply because they do not constantly offend the eye or the olfactory nerves. The evil influences arising from such accumulations are manifold. Wherever the water supply is drawn from wells or springs near the house, the drinking-water is liable to become infected with the germs of conta- gion. This may happen though the well is on higher ground than the cesspool or vault. For the suj)ply of water is drawn fi-om the bottom of the well, which is generally twenty feet or more in depth, and often below 476 AMERICAN APPENDIX TO the bottom of the cesspool itself. No matter how clear and cool the water may appear, it may coutaiu more seeds of contagion than the puddle in the street, which is open to the sun and au-. In the " Report of the State Board of Health, Lunacy, and Charity of the State of Massachusetts for 1880," an instance of well-poisoning is re- lated as follows : " If the risk is not in aU cases gi-eat fi'om the contamination of wells by vavdts, etc., 3-et it is often unsuspected, so far as any taste, smell, or appear- ance of the water is concerned, and maybe attended with the most serious results, a striking illustration of which is fm-nished by Dr. George Atwood, of Fairhaven, as ha^ing occiu'red in his experience. "In the latter part of August, jMi-. was ill with what seemed to be dysentery, but not so as to prevent his keeping about. On September 7th, he felt quite ill and sent for Dr. Atwood, who pronounced the disease typhoid fever. In the meantime his dejections had been passed fi-eely in" the privy vault, which was one hundred feet distant from the well (nearly twenty feet deep) and separated from it by a dry gravel and loam. After this date there were two heavy rains, presumably washing the fluid and soluble por- tion of the excrement from the vault, through the soil into the well, by a channel ah-eady formed or by soakage into the gi-ound water. The water in the well was very low at the time, and could be aU pumped out in a few minutes. " September 30th, the wife became ill with tA-^^hoid fever. " October 3d, a daughter became ill with typhoid fever. "October 6th, another daughter became ill with t^-j^hoid fever. " October 7th, two sons became ill with typhoid fever. " October 8th, another daughter became ill AAith tA-;[Dhoid fever. " October 12th, another daughter became ill with typhoid fever. " The youngest boy had the disease in a mild form, beginning about the middle of October. "An examination of the well-water by Prof. Nichols, October 17th, showed that it contained in parts per 100.000. Ammonia 0.001 Albuminoid ammonia 0.013 Total solids 20.030 Chlorine 3.300 "In order to ascertain whether there was a du-ect communication be- tween the vault and well, a bushel of coarse salt v\-as jDut in the vault October 24th, and a bushel of fine salt October 31st, and the subsequent chemical examination gave the following result : "Amount of chlorine in parts per 100.000. Dates. Dates. October 26th 3.9 October 29th 3.9 November 2d 4.0 November oth 4.4 November 8th 3.5 November 13th 3.4 November 17th 3.4 November 20th, rain 3.3 November 23d' 3.1 November 26th 3.1 November 30th 3.0 December 3d = 2.9 while before putting in the salt, the chlorine was, as stated above, only 3.3. "It seems clear that the effect of the salt was directly felt in the well, ' Water low in well. ^ Water low. EEMOVAL OF HOUSE-WASTE. 477 and that there was abundant opportunity for the dejections of a man ill with typhoid fever to pass into the water which his family were in "the habit of di'inking. No other cases of typhoid fever were known to ha;ic^ occurred in the vicinity during the summer." Other cases of a similar nature and with similar results are cited in the same report. It may be argued, however, that wells are fast being abandoned in our towns and villages, and that wherever circumstances admit, water is intro- duced by street mains for public use. No one will question the advantages of a public water-supply, when a proper and rehable source is found ; but it must not be supposed that Such an improvement renders the privy vault and cesspool harmless or even tolerable. The people may get pure water to drink, but other and new sources of trouble arise as follows : As soon as water flows freely from faucets, and the labor of pumping is avoided, the consumption of water for domestic purposes is found to in- crease at least fivefold. Indeed, the leakage from imperfect and cheap fixtures is often enough to raise the amount to ten or even twenty times the quantity formerly raised by hand pumping. The quantity of filth discharged from the house may not be increased, but the volume of sewage which is thus sent into the cesspool is soon visibly in excess of its powers of absorption. Sometimes the cesspool over- flows upon the surface, making a nasty place in the grass overgrown with rank herbage. Sometimes it soaks through the ground along the outside of the house- drain which brings it and makes an entrance through the joints of the ceUar-walL The writer recently saw a case where sewage had thus soaked in under a pile of coal, out of which the foul stuff slowly worked its way about the cellar floor. It often rises in the cesspool above the mouth of the inlet-pipe, stop- ping the usual circulation of air through the drain. This is almost always followed by the forcing of foul gas through the traps in the basement story. The undue pressure finds new leaks in the drain, and works untold mischief where least seen and least thought of. Even when the workmanship is perfect, a result but rarely found, the result is far from desirable. The owner constructs new cesspools one below the other, till every available place is exhausted, and the pollution reaches his neighbor's lot without aflbrding relief. The absorbent powers of the soil soon become overtaxed and the accumulation continues, crowd- ing into every crack till all the soil in the vicinity of the house is a mass of corruption. The more water the family use, the worse is the nuisance. The apparatus for cleaning vaults and cesspools is repeatedly called upon, and the neighbors all become disgusted with the operation, while the cost of these frequent emptyings becomes onerous. The soil about the house thus becomes pestiferous. Emanations are constantly going on during the summer which are certainly depressing to the vigor, if not actually poisonous. Now what is the remedy for this ? A candid investigation of the case can lead to but one reply, viz. : That the development of a system of pub- lic sewerage must progress pari passu with that of a public water-supply. The administration of any town or city that ignores this maxim is surely planting the seeds of future pestilence, while seeming to promote the wel- fare of its people. The demand for a supply of water is naturally more easily appreciated by the masses than the need of sewers. But it is quite 47S AMERICAN APPENDIX TO PARKEs' HYGIENE, time for those men who have at heart the jDermauent welfare of the com- mmiity in which they Hve, to look beyond the clamor of the people and carefully to weigh all the probable consequences before taking a step which may lead in the wrong direction. It may perhajDS be urged that the system of removal of filth by icater car- riage is not a necessai*y result of the introduction of a public water-supply. There are many towns where a system of dry removal of house offal has been attended with a degree of success. This system has many advocates in England, where it has had the widest development, and is doubtless worthy of some attention. Its friends urge in its favor the forcible argument that agriculture demands all the w^aste products of our towns, and that these substances should be carried to the farms, where they are needed, without first diluting them with a bulk of water which renders their transport and utilization too costly. The Chmese are sometimes quoted as an example of a frugal people, who do not aUow such things to be wasted ; they pick up in the streets the droppings of all animals before allowing them time to become an offence. The cheapness of labor in China undoubtedly ena- bles them to do many things there with better economical results than the same methods would produce with us, but the facts do not prove that the real sanitary results in Chinese cities are better than in our own. Tiie same system is pursued — or at least has been till very recently — in many of the old towns of Southei'n Europe. No one can walk about the narrow streets in Naples, Palermo, or even some parts of Rome, without great risk of defil- ing the boots with human ordure. In Madrid, we are told that not even a privy existed in 1760,' "It was customary to throw the ordure out of the windows at night, and it was removed by scavengers the next day. An ordinance having been issued by the King that every householder should build a privy, the people violently oj)posed it as an arbitraiy proceeding, and the physicians remonstrated against it, alleging that the filth absorbed the unwholesome particles of the air, which otherwise would be taken into the human body His Majesty, however, persisted, but many of the citi- zens, in order to keep their food wholesome, erected privies close to their kitchen fireplaces." All this may justly be called lack of system, when compared with the methods piu'sued in the modern towns of Manchester and Rochdale, in England, where the system of " dry removal " has had as great a degree of success, perhaps, as anywhere. But even there the results are far from satisfactory. Such a system can only be made tolerable by the enforce- ment of a rigid discipline in its administration, and is, therefore, better adapted to prisons, barracks, hospitals, etc., than to communities gov- erned by civil law. It may possibly be satisfactory in a small community or a somewhat scattered population, but its success depends upon great thoroughness in the daily attendance — a thing which it is difficult if not impossible to attain in large towns, especially when governed, as with us in America, by officers annually elected by the people. In short, its ad- ministration, if properly conducted, partakes largely of the character of what is known as paternal government, and is in no degree automatic. The apparatus, moreover, is cumbrous and often offensive, as well as the processes involved — such as the carting through the streets, etc. No sys- tem of dry removal provides for the waste waters of the laundry, scullery, etc., which, in large towns, are quite as important items and quite as likely ' Dr. Edward Barcome in his History of Epidemics, as quoted by Baldwin Latliam in Sanitary Engineering, p. 31. REMOVAL OF HOUSE-WASTE. 479 to make trouble as the alvine discliarges. In view of these considerations it is not surprising that the system of removal of filth by water carriage should be ah'eady largely accejoted by our people. Its popularity is in- deed so great, that scarce any other method is known or considered in the hundreds of new towns which are constantly springing up all over the West. In fact, the use of the water-closet is not confined at all to towns or houses provided with a public water-supply. It has become a matter of course in the country house as well as in the village or city. It is, therefore, to be taken for granted now that every good house must be provided with this convenience. It has become rather a necessity than a luxury among all who can afford its moderate cost. Accordingly, the cesspool, among all suburban districts as well as in many villages and towns, has taken the place of the old privy vaiilt. So far as the closet goes, if properly devised and ventilated, properly located and constructed, it is a long step in advance of the privy. But the gain is not a great one if the ordinary leeching cesspool is the receptacle of the discharges. The only proper disposal of the flow from water-closets, among all communities that can afford it, is a well-devised system of sewerage de- livering the flow either on the land or into the sea, but not into any small rivers or watercourses whatever. This, of course, is applicable to large towns and cities, not to a scattered population, the needs of which it is proposed to consider later. The development of a proper system of sewers is entirely a local ques- tion, and should be studied and perfected by experts in every locality where it arises. Yet some general rules have been established by the experience of the first twenty years which it would be best to conform to m all cases. Ultimate Disposal of the Sewage. First, as to the ultimate disposal of the sewage. This subject has been so thoroughly probed and discussed that we can avail ourselves of the inves- tigations of some of the most intelligent men of our day. " In Berlin a scientific commission was appointed in 1862, and made exhaustive experi- ments, continued through many years. They proved by scientific analysis and by induction, what had long before been learned in England by prac- tical experience.' " I. That with cesspools and privies, the soil and well-water become dangerously polluted. "11. That sewers need not pollute the soil. "in. That streams become so foul when used as receptacles for sewage, that measures must be taken for their purification. " IV. That the only practicable means of purifying sewage is by irriga- tion." "They have, therefore, adopted a sewerage system which is to be com- pleted in 1883, and which provides for the purification of the sewage by ii'rigation." In 1876 a committee was appointed by the Local Government Board of England to inquire into the several methods of treating sewage. This Committee arrived at the following conclusions, which are quoted from their report : ' Seventh Annual Report of State Board of Healtli for Massachusetts, 1876, p. 310. 480 AMERICAN APPENDIX TO PARKEs' HYGIENE. "1. That the scavenging, sewering, and cleansing of toi^'ns are necessarj- for comfort and health, and that in all cases these observations involve questions of how to remove the refuse of towns in the safest manner, and at the least expense to the rate-payer. '* 2. That the retention, for any lengthened period, of refuse and excreta in privy cess-pits, or in cesspools, or in stables, cow sheds, slaughter houses, or other places in the midst of towns, must be utterly condemned ; and that none of the so-called dry earth or pail systems, or improved privies, can be approved, other than as palliations for cess-pit middens, because the excreta is liable to be a nuisance during the period of its retention and a cause of nuisance in its removal ; and moreover, when removed, leaves the crude sewage, unless otherwise dealt with by filtration through land, to pol- lute any watercourse or river into which such sewage ma}' flow. We have no desire to condemn the dry earth or pail system for detached houses, or for public institu- tions in the country, or for villages, provided the system adopted is carefully carried out. "3. That the sewering of towns and the draining of houses must be considered a prime necessity, under all conditions and circumstances, so that the subsoil water may be lowered in wet districts, and may be preserved from pollution, and that waste water may be removed from houses without delay, and that the surfaces and channels of streets, yards, and courts may be preserved clean. " 4. That most rivers and streams are polluted by a discharge into them of crude sewage, which practice is highly objectionable. " 5. That so far as we have been able to ascertain, none of the existing modes of treating town sewage, by deposition and by chemicals in tanks, appear to effect much change beyond the separation of the solids and the clarification of the liquids. That the treatment of the sewage in this manner, however, effects a considerable improve- ment, and when carried to its greatest perfection, may in some places be accepted. " 6. That so far as our examinations extend, none of the manufactured manures made by manipulating towns' refuse, with or without chemicals, pay the contingent costs of such modes of treatment ; neither has an^' mode of dealing separately with excreta, so as to defray the cost of collection and preparation by a sale of the manure, been brought under our notice. " 7. That town sewage can best and most cheaply be disposed of and purified b}' the process of land irrigation for agricultural purposes, where local conditions are favorable to its application. But that the chemical value of sewage is greatly reduced to the farmer by the fact that it must be disposed of day by day throughout the entire year, and that its volume is generally greatest when it is of the least value to the land. " 8. That land irrigation is not practicable in all cases, and therefore, other modes of dealing with sewage must be allowed. '' 9. That towns situated on the sea-coast, or on tidal estuaries, may be allowed to turn sewage into the sea or estuary, below the line of low water, provided no nuisance is caused ; and that such mode of getting rid of sewage may be allowed and justified on the score of economy." Signed by Robert Rawlinsox, Clare Lowell Read. The Combination of Sewage j^u) Scrface Water. After providing for the ultimate disposal of the sewage, among the many questions to be decided in planning a system of sewei-age for any given place is this. How large a poi'tion, if any, of the surface-water drainage is to be admitted into the sewers ? It has been customary in most cases to provide sewers for the removal of all the sui-plus rain-water which would collect in the streets, together with the house drainage. Of late, however, several small towns, both in England and this country', have provided sewers for the house drainage alone, or admit a very small quantity of the surface- water, the larger part of which is either left to flow off on the surface or by special conduits leading to natui'al watercotu'ses. This last has often been called the sejMrate system of sewerage. It has the follo^'ing advantages, which operate with most force, however, in small toicns, viz., economy in consti'uction, and freedom from deposit when in use. The sa-^dng in cost will be apparent when we consider that in the combined system the size of sewers must be adapted to caxrj the heaviest REMOVAL OF HOUSE-WASTE. 4S1 rainfall, which in our climate often brings into the sewers connected there- with a volume of water some twenty to thirty times as great as that of the sewage alone. It is sometimes found, as at the city of Memphis, Tennessee, where the separate system is used, that a six-inch pipe is sufficient to col- lect the sewage for a continuous length of over haK a mile of street, lined with houses ; while if the rain-T^ater were to be provided for, a conduit of many times that capacity, with a con-esponding cost, would be required. The second advantage refeiTcd to, that of freedom from deposit, arises from the frequency of the maximum flow in small pipes, which causes such sewers to be seJf-cleandng to a greater degree than in larger ones. The small sewers are4ikely to be half filled by the daily flow, during at least a part of the day, while the large ones, proportioned for carrying rain-water, may be so filled only at rare intervals, during heavy rains, and for a great part of the time they carry only a driblet, say five or six per cent, of their whole capacity. The small pipe can be flrished daily by a moderate expenditure of water, and should be so flushed, while the large sewer would require a larger quantity of water to properly flush it than most towns could conveniently supply. It therefore would seldom get flushed except by heavy rains, which occur at long intervals, between which serious deposits may sometimes occur. Another and a very important reason for keeping the sewage separate from rain-water exists in aU those localities where the sewage must be artificially treated in any way, either by chemicals or otherwise ; also where it must be pumped to bring it to the desired place for ultimate disposal, or where it is used for irrigation of crops. It is evident that it would be a great drawback upon any system for handling the sewage, if the plant for this purpose must be adapted to a maximum flow that occurred only at long intervals and for short periods, after heavy rains, leaving a large portion of this plant idle for three-fourths or nine-tenths of the time. If sewage is disposed of by irrigation, which, as we have seen above, is recommended as the most satisfactory method of purifying it, the only way to recover any part of the cost of the process is to apply it to growing crops. If a considerable part of the rain-water is mixed with the sewage, this great difficulty arises, viz.: The whole flow must be disposed of daily, and no crops can thrive if subjected to flooding in periods of rain, while but scantily watered in times of drouth. In short, the farmer could not raise a crop with profit who was obliged to take ten times as much water as his crops need after a rain, even if supplied tolerably well in the drouth. The objections to the separate system are as follows. It will be seen that they apply with considerable force in large towns, or those of dense population, and as many towns now small and scattered may hope to be- come large and dense, as experience has shown they often do in our country, it behooves such towns to be cautious about committing them- selves to a system which may bring much trouble eventually, and prove in the end to be more costly rather than less. It is found that wherever the streets are paved and the traffic is large, the flow of water from their surfaces after a rain, and more especially after the melting of winter snows, is as foul as the flow in the house drains, and therefore as unfit to be conducted into running streams or ponds as any form of sewage. In fact, the street wash of Boston or New York, when the snow is melting in April, is so foul that no proper disposition can be made, of it separately from the sewage, and therefore no plan for so separating if could be reasonable, expedient, or productive of good results. Vol. II. -31 482 AMERICAN APPENDIX TO PARKEs' HYGIENE. If two sets of conduits are required, one for the flow of sewage and another for siu-face water, no certain saving in first cost would result. In fact, a combined system would often cost less than the two. Moreover, two sets of conduits under our streets would lead to much trouble in arranging the details, such as the proper levels, and which pipe should pass over the other where intersecting at street corners. Trouble has also arisen whei-e such a double system existed, in the service pipes of one s^'stem being interfered with by the main of the other system in trying to construct such sei'vices on proj^er slopes between the houses and the mains. Mis- takes are hkel}^ to occur, also, in making the private connections to the mains, by entering the wTong main, which class of mistakes are difficult to avoid in such a complication, where the administrative officers and fore- men in charge of the work are subject to change in their personnel. Large sewers are now constructed so as to be more self-cleansing than formerly, by contracting their section at the bottom, so that the stream flows over an invert in the large sewer of a similar shape to the lower half of a small pipe. Fig. 109, which is copied from Baldwin Latham's work, shows the im- provements made in this respect. Fig. 109. Old Form of Oval Sewer. New Form of Oval Sewer. Since it is not proper to discharge crude sewage into small streams, aU towns that are remote from the sea or very large livers should provide for the purification of their sewage, to prevent it from becoming a nuisance. The system of disposal of sewage by inigation of the sdil has been referred to above, as the most efficient, most economical, and least harmful of the processes hitherto tried for its pmification, at all places where a suitable ojiportuuity can be found, within a reasonable distance, for its development. Its application has hitherto been limited in this country to a verj' few cases, and even in these the experiment has been on a small scale, e. g., the hospitals for the insane at Worcester and at Dan vers, Mass., and at Augusta, Me. This method can never be pursued with any prospect of economic results as to the crops produced on the sewage farms, unless the collection of the sewage should be made without much or any rain-water. The exclusion of the surface water becomes more imperative in America than in England for the reason that American towns which have a pubhc water-supply consume a much larger quantity of ■water per capita than European ones, by means of which the sewage is more largely diluted, and therefore of less value as a manure per ton. The distribution of water in most of our towns is not only liberal but lav- ish, being aggravated by a reckless waste which the municipal authorities EEMOVAL OF HOUSE-WASTE. 4S; have hitherto taken no efficient steps to check in most cases. The enor- mous expenditure for fixed plant in water-works which has taken place in cities like New York, Philadelphia, and Boston, with the actual quantities of water now distributed, would, if properly husbanded, supply hberaUy fully twice the present j^opulation in these cities. No large city of this class can ever dispose of their sewage upon the land with a hope to pro- duce crops by irrigation, tiU some way shall be provided for checking this prodigal waste of water and thus rendering the sewage less dilute in its character. The sewage farm at Barking, on the Thames, has a small por- tion of the sewage of London to dispose of, and its profits have been reduced to a microscopic amount, if not a negative quantity, by this super- abundance of watei'. Yet the quantity of water distributed per capita of population in London is far less than that enjoyed and M-asted by the large American cities. The following table is made up from " Croes' Statistical Tables," giving figaires for 1880, for eleven prominent American towns, while those for London are taken from official reports quoted at London for the same year, in Engineering (vol. xxx., p. 195). Consumption of Water in 1880, in various American Cities, compared with London. Citj. Population. Gallons daily. Daily consump- tion per capita. New York 1,206,299 847,170 566,663 503,185 362,839 350,518 313,190 255,139 233,959 156,389 159,871 4,388,000 95,000,000 67,647,782 34,616,831 66,163,942 38,214,700 27,500,000 25,000,000 19,524,847 13,824,000 16,021,624 26,525,991 150,398,107 78 Philadelphia, Pa 80 Brooklyn, N. Y 61 Chicago, HI 131 Boston, Mass 105 St. Louis, Mo 78 Baltimore, Md 79 Cincinnati, 76 San Francisco, Cal 59 Pittsburgh, Pa 102 Washington, D. C 166 London, England' 34 But it is the opinion of all sanitarians, that for all inland towns having no opportunity to discharge their sewage into the sea or some large river in a way which would create no nuisance, the purification of their sewage becomes imperative. For this purpose irrigation is the only rational method of treatment, and should be adopted, even if the crops produced are not a source of profit. If the notion of profit is abandoned as unattain- able, the process may be much simphfied by allotting more sewage to the ' The consumption in London is doubtless reported here in imperial gallons of 288 cubic inches, while the American cities reckon by wine gallons of 238 inches only. - This would require an addition of 25 per cent, to the figures given for London to make the comparison fair ; but on the other hand the consumption in London is re- ported for the month of July only, which is doubtless larger than the average for the year, perhaps by an equivalent ratio. Moreover, the report of the London official gives only the population actually served with water in their houses, which we sup- pose to be a smaller ratio of the whole population than is the fact in American cities. 484 AMERICAN APPENDIX TO PARKES' HYGIENE. area treated than the crops could be expected to profitably use, and re- moving the water by uuder-drains after it has filtered through the soil. Such a process cannot be kept up continuously with success. There must be intermission by means of two or more fields for alternate treatment, giving each field such period of rest as will enable the water with which it is gorged to soak down and admit the air to the pores of the soil. It is this ver}- air in the pores that does the work of chemical purification by means of its oxygen, which process is moi'e important and more ejSicient for the purification of the effluent water than the straining or mechanical filtration. This process is iDerfectly applicable to villages and small towns, and re- quires less expenditure for its maintenance than is generally supj)osed. It. is not entirely automatic, however, and needs frequent attention in divert- ing the flow from one plot to another, as often as the soil becomes sat- urated. Such attention, however, would not be an onerous tax upon a village of a thousand inhabitants or more. Irrigation below the Surface. For all small villages or collections of houses, as well as for single houses in the country where the land is not entirely flat, a distribution of the sewage can be made, about a foot below the surface, by porous tiles, which has been tried both in England and this country with success ; and the process is nearly automatic when the apparatus is properly prej)ared, requiring attention only at loug intervals. The requisites for this system are as follows : First. — Land adapted to grass, nearly level or gently sloping, at the rate of one-fourth of an acre for a single family, or an acre for a combin- ation of eight to ten families, if provided with a constant water-supply under jDressure. If the water-supply is limited to what may be pumped by hand, one-half of the above area will be ample. Second. — -The highest part of the land devoted to the piirpose should be at least five feet below tlie level of the toj) of the drain where it leaves the house. Third. — The soil should be thoroughly under- drained, if not resting on a di-y and porous subsoil by nature. Under-drains are often needed in clayey or retentive soils, and should be laid at least four or five feet below the surface, at intervals of about twelve feet, with a free outfaU. Fourth. — The land should be graded, unless toleral^ly smooth before, hand, so as to avoid sudden inequalities. A surface that is adapted to smooth mowing by hand is good enough for the purpose. Fifth. — The soil must be entirely free from roots of ti'ees and shrubs. These would choke the pipes in a few weeks. The cost of the work will vary with the local conditions. It can be laid out by any intelligent mechanic, with an ordinary spirit level and straight- edge twenty feet long, though if on a large scale, requiring an acre of land or more to be treated, an engineer's level would be a convenience. If house drainage is conducted du-ectly into porous tiles laid under the surface, the fluid jDarts will escape at eveiy joint, while the sohd matter is apt to cling to the interior and gradually fill them, till they become practically useless, unless taken up and cleaned. In order to avoid this result it is advisable to provide a tank or tight cesspool whei-e all the sewage is arrested for a while, duiing which time EEMOVAL OF HOUSE-WASTE. 485 COwygg or C^ncygfaa . StpH ON Tank. Verticai- Seictiom* ° Ain Hoj-g OUTV^- |-(oLE AT A Capped amp Covej^ep \»/\th 5A.Ne Plan , ,AIH HOLE AND VENT PlPC TO Bt EXTENDED .TO A, PnoptH Place SeictiohBC, BOTTOM OF OUTLET ^,J-^<^Jlower end pr SIPHON Bottom of basin UNDEFl SFHON Fig. 110. 486 AMERICAN APPENDIX TO PARKEs' HYGIENE. the solid matters become macerated and finely divided by fermentation, before entering the distributing pipes. Moreover, if such a tank be allowed to overflow constantly into tlie porous pipes by a dribbling dis- charge, they would become choked after a while even then. In order to keep them free, the flow must be intermittent and take j)lace with such a rush as to till the whole system of distributing pipes at once, and brush away shght obstructions which may have been left by former dis- charges. There are two methods of obtaining this result : First, by providing a stop-gate in the outlet-pipe where it leaves the tank, to be opened by hand when the tank is full and. closed again when empty. Second, by pi'oviding a siphon or float to discharge the tank automatically whenever filled. Of course the latter method is far more satisfactory, if made rehable, but it is somewhat more costly, and the siphon, as heretofore constructed, is not always reliable, i.e., the apparatus for setting the siphon in action does not always work as expected. Field's siphon has generally been used for this pui'pose, and works well with pure water ; but if used with sewage on a small scale, it is Hable to miss, unless the cup into which it discharges is occasionally brushed out. When used on a large scale, as for a combination of several houses, this difficulty disappears. Several other devices have been used for starting a siphon. Li one a tumbler tank is placed in the upper part of the flush tank, which upsets when filled, tui'ning on brass trunnions, and righting itself at once when empty. A tumbler tank of two gallons capacity will start a sij)hon of two inches diameter, if the lower or discharging end dips in water as soon as the flow through it begins. It is ' important that it should not so dip when no ivater is flowing through it, for in that case the flush tank would never be filled again after once discharging ; but it can be so arranged that a very shght flow would seal the discharging end. The device patented by IVIr. Field was to accomplish this result. The tumbler tank accomplishes the result well enough when filled with pure water, but if used for sewage, the solid matters are apt to adhere more or less to its sides and thereby destroy its poise, on which its cer- tainty of action depends. Other devices have sought to accomplish the same end by a float ac- tuating a valve in the bottom of the flush tank, or by a bucket in a side chamber which can be filled by the overflow of the tank, and thereby be- comes heavy enough to open the valve, while a small leak in the bottom allows the valve to raise it again after the tank is empty. All of these contrivances are subject to failure from wear of moving parts except Field's siphon, which it is hoped may be perfected still further. Fig. 110 shows the two tanks and the Field siphon as modified by the writer, the changes being at least a partial remedy for the imper- fections complained of. If the siphon were to be applied as the outlet of the same tank which receives the sewage for maceration, etc., it would often become choked by solid matter. It is therefore best to provide a second tank between this and the siphon. The first is called the " settling basin " and the latter the "flush tank" on Fig. 110, for the last is alternately filled and emptied, while the first remains always full. Siphons are often constructed inside of the flush tank, but it is better to make them accessible at all times by placing them outside, as here shown. EEMOVAL OF HOUSE- WASTE. 487 A Fig. 111. — A, Section across Branch. Section lengthwise of Branch. A t"wo-incli siphon is as large as can be surely set in action by tlie drainage of a single house. The surest method of starting such a siphon would undoubtedly be to provide a copper float in the tank with an ordinary brass cock, such as is used on water-supjDly pipes for the automatic filling of house tanks ; but the float must be adjusted so that the cock should be opened instead of closed, when the sewage rises to the over- flow hne of the siphon. Supply this cock with jDure water under pressure from some outside soiu'ce by a small jDipe, and let the dis- charge be dehvered by a tight connection through the arch of the siphon, in such a way that it would fall free of the sides of the tube into the cup or basin where the siphon is made to discharge. A very small stream of water, thus ap- pHed, would start the siphon with certainty, and with scarce a moment's delay, if its discharging end is so placed as to be sealed with water by a shght flow. The outlet pipe for this aj)j)aratus should be four or five inch stoneware pipe for a two-inch siphon. If over one hundred feet in lengih, and on an inclination less than two in one hundred, the larger size may be prefei^able. The distributing pipes should be cylindi-ical and two inches bore. The quantity needed "v\t.U vary with the porosity of the soil and the size of the flush tank. The tank here shown contains STy'L cubic feet when filled. The j)ipe should be of sufficient length to contain about one-half this amount, say 19 cubic feet. Since the sectional area of a two-inch pipe is 3.14 square inches, it will requii'e about 46 linear feet of the pipe to contain one cubic foot. They should then be about 46 times 19, or 874 feet in length. If the soil is ex- tremely porous, a smaller quantity would doubtless answer the purpose, since a larger proportion of the water would soak away while the siphon is discharging the tank. These distributing pipes should be laid with a perfectly uniform slope of not over six or eight inches in one hundi'ed feet. Even less than this will often answer. If the slojDe exceeds this amount, the water may bui'st up at the lower end and make a nuisance. They should not be covered over ■«-ith Trough; eight or ten inches below the surface of the ground. In order to combine these two conditions, the ground must be somewhat smoothly graded, and the lines for the pipes must be laid out to conform to the con- tour of the surface, i.e., the trenching must follow hnes which have a sui'- face slope limited as above stated. The trenches may be at intervals of Fig. 112.— Per- spective VieTV of Un- glazed 2-inch Tiles and Covers. 488 AMERICAN APPENDIX TO PARKES HYGIENE. five or six feet, dividing tlie field in a gridiron fasliion. The tiles must be laid one-fourth of an inch open at joints. The branches where the two-inch pipes leave the main should be so made as to allow no fluid to be retained in the main, but lead fi'om its bottom, as shown in Fig. 111. The branches can be made rights and lefts to suit the places where used, and can be either of the Y or J form. Ordinary piiDe-branches are in- tended for combining two streams into one, but these are for dividing one stream into two. They should, therefore, be formed as shown in the draw- ings, having no socket on the small hole, which is to abut against the first piece of two-inch tiles. These porous tiles have sometimes been laid upon boards bedded in the trench, to seciu-e a more uniform gradient and pre- vent dislocation of joints; but the decay of the boards soon allows the pipe to become displaced by settlement, and it is better to place ten-a cotta troughs under the pipe, breaking joints therewith. Similar pieces, about four inches long, are placed over the joints as covers (see Fig. 112). It is often objected to this system that the pipes would become filled with ice in Northern winters unless buried deeper than eight inches. But experience has shown that such is not the fact near Boston. If buried deeper, the roots of gi-ass and the air do not get so good access to the sew- age, which is therefore likely to accumulate — a result which we wish by aU means to avoid. When laid near the surface no such accumulation occurs, and the fi'equent flow of warm water from the house prevents the gi'ound from freezing under and around the pipes, if covered with sod. In places where a sufficient slope exists, the sewage of single houses may be distributed on the surface with advantage. The above cut shows such a method, which has been in use for several summers at a house used only as a summer resort, and has been attended with comi^lete success. There is an overflow pipe fi-om the cesspool, which is perfectly tight, indicating when it is full. The gate in the outlet-pipe is then opened and the whole contents distributed on the kitchen garden in ten minutes*. If an opportunity is selected when the wind is blowing from the house to the garden, no offensive odors are perceived, and the growing crops soon absorb the fluid, much to their advantage (see Fig. 113). Disconnecting House Dratks from Sewers. The complete separation of the air-space in our house drains from that in the public sewers is now insisted on by most European municipal authorities where regulations are enforced on such subjects. This separa- tion is even more important in cases where a cesspool is used in place of a sewer, for the gases of the cesspool are much the more foul, and no EEMOVAL OF HOUSE-WASTE. 489 amount of ventilation will prevent their becoming so. The cesspool is but a retort where such gases are constantly evolved from the decompo- sition of the fluids and sohds retained in them. The devices for attaining this separation which are apphed in England are not so well adapted to the climate of New England, Here the severity of the winters requires the separating trap to be placed several feet under the ground, and as it should be kept accessible, a man-hole or well is gen- V//////////Z Fig. 114. — Main Trap and Air-hole for House Drain. eraUy constructed over it in brick-work, with a perforated iron cover at the top, as ^own in the annexed cut (Fig. 114). If this is used in a snowy climate, a bent pipe should be extended fi-om the interior of the chamber to a point a few feet above the surface, where it may be protected by a wire-basket. Little or no offence is hkely to arise from such an opening. The Ventilation of House Drains. This subject has attracted much attention of late, and deserves careful consideration. The hability of the interior surfaces of house drains to be- come foul by the accumulation of solid matter, or from the formation of a slimy coating of organic matter on their interior walls, is well known, and the high temperature of the di'ains as compared with that existing in the sewers conduces to a more rapid decomposition of such matter than in the sewers themselves. A constant change or current of air thi'ough every part of the di-ain, is therefore essential to avoid the concentration of such gases. If such concentration occui', the risk of harm is multipHed, by the weU-known law of diffusion of gases, by which they penetrate very smaU cracks, and through imperfection of workmanship or inefficiency of the water seal in the traps, might enter and mix with the air of the house. "When houses are artificially heated this tendency is increased by the diminished density of the air within the house, causing a shght inwai-d pressure through all such fissui-es. Our best municipal codes now require the house di-ains to extend up through the roof over every separate " stack " or vertical hne of soil pipe, of a size not less than four inches. This size is found necessaiy in order to avoid accumulation of frost by condensation at the top, and other rea- sons. In order to provide a draft through these pipes, the fresh air should be freely admitted to the drain at its lower end, next to the trap by which it is separated from the outside drain and sewer. Such an oj)ening as referred to in connection with Fig. 11-4, can be made 490 AMERICAN APPENDIX TO PARKEs' HYGIENE. to terminate an}T\'laere above ground, and within a few feet of the siu-face, without risk of offence, for the draft is ahnost always inward. It is custo- mary to terminate them by a pipe extending some three feet above ground against the j-ard fence, with some protection at the orifice, to prevent stones, etc., from being thrown in by childi'en. The need of a draft thi'ough every part of the house drain is not the only reason for their being open to the aii' at the top. It is impossible to retain the water seal in the best forms of traps — the most simple ones— un- less the atmospheric pressure is freely admitted just below the water seal. The jiartial vacuum that follows a charge of water as it descends a verti- cal hue of pipe is such that, without a free admission of air below every trap, the pressure on the house side of the Fig. 115.— Veuted s-Traps. trap would force the water through them and leave them unsealed. It therefore becomes necessary to apply branch vents to each separate tube (see Fig. 115). This is particularly needed in connection with waste pipes smaller than four inches in diameter*. In order to ascertain the amount of risk incurred by lack of air in the outlets of traps, the writer was employed by the National Board of Health, in the summer of 1882, in connection with E. W. Bowditch, Esq., to make a series of experiments with apparatus constructed for the purpose. The folio ^^-ing• is an abstract of the rejjort upon these experiments, pubhshed in August, 1882, in columns of the New York Sanitary Engineer : " A typical stack of four-inch, and another of two-inch waste pijjes were erected in a vertical position, extending fifty-seven and a half feet above the basement floor, ■s\ith branches in the basement and on the floors above, and having the upper ends open to the aii* eight and one-fourth feet above the upper floor. " The vertical pipes extended down to a point two feet above the base- ment floor, from which they turned to a slope, falUng this two feet in a horizontal distance of thirty-two feet. " The two-inch waste joined the four-inch pipe at a branch on this slope five and a half feet from the lower end of the vertical portion. A foui'- inch running trap was attached to the lower end of the slope, having a foui'-inch air-hole close above it, to represent the foot ventilation. At a point on the slope six feet below the lower end of the vertical reach, a branch was inserted with a four-inch traj) in it, marked (n) on the plate, to represent an inlet for a basement water-closet, or for any other desired fix- ture at that level. The relative position of these branches and flows is shown on the accompanying plate (Fig. 116). "Traps may lose thefr water seal hj siphon action, i.e.,\yj lack of afr- pressure, either when water is poured through them, or when poiu'ed through the main waste pipe into which they discharge from fixtures at a higher level. These two processes are, therefore, examined separately, as desci'ibed below. " Since it is now generally admitted that the upper ends of all soil or waste pipes should be wide-open to the aii', all experiments were tried under this condition, except where otherwise noted for sjDecial purposes thei'e explained. " "We will first consider the loss of the water seal in traps caused by water flowiut? thi-oui^h them from the fixtiires attached thereto. WAVES Tank- i~i n Fig. 116. Xdbu^Tj^a^f, ^ (jiArK Jrtya, WWV^ ' tkW_-'a [ &a»8Wk^W;ji ! W T ia^ ^ mMn~.\\\^ii^A/ iM^y''S'A)i.M/,7^!^^ jK^-^'.i^-/r,,/A& Quantities poured in expressed in depths of ' water in the pail. 3 inches. 2 (( If inch. u H 1 a. 4 i 1 4 1 4 492 AMERICAN APPENDIX TO PARKEs' HYGIENE. "A. Experiments with a Two-inch Waste-pipe, open at the Top. (1) "A conical hopper was placed at the upper floor, over the two-inch S-trap at (e), having Ig inch depth of seal, and having a branch of two inches calibre twenty-one inches long, with a descent of one foot, before joining the Y-branch on the main at D. " This trap was found to lose its seal completely every time a two-gallon pail was emptied into the hopper, unless pains were taken to pour the last part of the water slowly, by which the seal might with cai-e be restored. (2) " Smaller quantities of water were then poured in quickly, as is often done in practice, with the following results : Loss of water in trap. 1|- inch , seal lost. If " " 2^ inches " 21 a (t 5 2 " •-' 1| inch If " " n '' " 1 " seal kept. 1^ " seal barely kept. (3) " In order to test the effect of a strainer in retaining the water by checking the flow, two cross-bars were then inserted, just above the trap water, to represent a bar-strainer. Water, to the amount of one and a fourth inch in depth in the bottom of the pail, was then poured into the hopper, but the trap still lost its seal, the water in it being lowered one and three-fourths inch. (4) " To test the effect of a vent pipe on this combination, a hole was cut at the crown of the trap, and one end of a lead pipe of one-inch calibre and twenty-eight and a lialf feet in length was coupled to it. The pij)e lay in a coil on the floor with the other end wide open. Nine full pails of water were then emptied into the hopper, the loss of water in the trap, on measurement, being found to be as follows, after each pailful, \iz. : 1^ inch, ^ inch, ^ inch, ^ inch, f inch. If inch. If inch, ^ inch, nothing. The seal was lost twice. "The manner in which the water was poured influenced the result materially. Less water was lost if it hit on one side of the hopjDcr and whirled about during its downward flow, than if it was jjoured in directly toward the centre, without such spiral motion. (5) " The vent hole was then enlarged, and a coil of pipe of 1^ inch calibre was coupled on to it, having a length of fifty feet. Ten pailfuls were then quickly poured into the hopper in succession, finding the loss of water in the trap after each as follows, the strainer remaining at the bottom of the hopper : 1 inch five times, |- inch twice, ^ inch once, ^ inch twice. So that there was always at least f inch of water seal remaining. A shorter vent pipe of same size, or a larger one of same length, would of course produce better results by lessening the friction encountered. (G) "Closing the vent hole, an ordinary wash-bowl was then placed over the same trajp, having an outlet of 1^ inch diameter, with a bar- REMOVAL OF HOUSE- WASTE. 493 strainer. It -was filled several times and discharged -without losing any water that could be detected from the trap. Such traps often do lose their water, however, in practice, when discharging into smaller wastes, under circumstances otherwise similar, except as to the cleanness of the in- terior of the pipes. " B. Experiments with a Four-inch Waste or Soil-pipe, open at the Top. (1) " A conical hopper was placed on the third floor, on the four-inch S-trap, at (b), having a water-seal of 1^ inch, with a branch twenty-two inches long between the trap and the Y-branch on the main, "Five pailfuls in succession were poured into the hopper, with loss of water as stated below, viz. : f inch, 3^ inches, 2 J inches, f inch, 2f inches. The seal was thus lost three times out of the five. Smaller quantities of water were then poured in, with the following results, viz. : Quantities of water in bottom of a t„^„ „f ^ +;, :„*„„„*„ two-gallon paU. ^°®' °^ "^'^P*^ ^'^ ^'^'^P ^^^«*- HaK full. 2 inches seal lost. 3|- inches deep. If inch. 3| " " 2 inches seal lost. 5 " " . 3f " Q (I it OJL " " (2) " A vent pipe, 1^ inch diameter, and one foot long, was then in- serted in the upper side of the pipe, six inches below the crown of the trap, and ten pails discharged in succession, with the result of losing the seal completely three times, and having but -^ inch seal two other times, while the remaining five trials lowered the water respectively f inch, 1-^ inch, I" inch. If inch, and 1:^ inch. (3) "The size of the vent was then increased to two inches. Six suc- cessive pailfuls were emptied, lowering the trap water as follows, viz.: 1 inch, 1:^ inch, J inch, If inch, If inch, 2^ inches, the last losing the seal. (4) "The vent pipe was then increased to three inches in diameter, stiU one foot long. Ten successive pailfuls were emptied, with losses of trap water as follows, viz. : If inch, 1^ inch, 1^ inch, 1 inch, ^ inch, f inch, ^ inch, 1^ inch, 1^ inch, 1^ inch. The seal being lost once, (5) " This vent hole was then sealed up, restoring the original form of the pipe as far as possible, and another vent pipe of 1^ inch diameter and one foot length was inserted on the highest part, or crown of the trap. Nine successive pails were emptied, with loss of water in the trap as follows, viz. : 1^ inch, 2f inches, 2 inches, 1 inch, 2^ inches, f inch, ^ inch, 1^ inch, 1^ inch. The seal was thus lost three times out of nine. (6) " The vent pipe, still one foot long, was enlarged to two inches, with an elbow two inches long, at its upper end. Ten pailfuls in succes- sion were emptied with the following losses in the trap, viz. : l^^g inch, 1^- inch, 1^ inch, 2^ inches, 1^ inch, 1| inch, ^ inch, 1^ inch, :^ inch, 2|- inches. The seal was here twice lost, and came very near it twice more, (7) " The vent pipe, one foot long, was then increased to three inches diameter. Ten pails were emptied, with loss of water as follows, viz, : ^ inch, f inch, ^ inch, f inch, 1^ inch, 1 inch, f inch, ^ inch, f inch, 1^ inch. The seal was not lost now, though coming within f inch of it. "In all these three last experiments, where the vent was in the crown 494 of the trap, the water was seen to dash wp into the vent pipe, and spill over the top of it, even when a foot long and three inches diameter. When it receded, a portion of this water dropped back into the trap, and just sufficed to keep its seal when the vent was thi'ee inches in diameter, but not when smaller. The loss of water was plainly attributable to the momentum of the stream when passing through the traj), quite as much as to the air draft. This was proved by varying the direction in which the water was poured into the hopper. The above records are all the results of pouring it in at the side of the hopper opposite the trap, so that the velocity of the water acquired in its fall from the pail through the hopper was not impaired by such an abrupt change of direction, when striking the bottom of the trap, as it would be if the pail were applied either directly over the trap, or half-way between this and the former position. Moreover, there was no strainer at the base of the hoj^per, to break the momentum, the hopper being of the form formerly much iised for Avater-closets. (8) "In order to eliminate, in some degree, the effect of this momentum, the same experiments were tried with another form of hoj^per, suitable for a water-closet, and having its trap above the floor, such as is marked ' Water-closet No. 1 ' on the plate. The distance through which the water had to fall from the edge of the hopper to the bottom of the trap was thus reduced by ten inches. The trap had a seal of two inches, and was first tried with no vent in it. It discharged directly into a patent Y- branch with expansion at toj), devised for the purpose of preventing siph- oning. Nine pailfuls were emptied with a lowering of the trap water as follows, viz. : 1 inch, -k inch, If inch, 2 inches, ^ inch, nothing, 2^ inches, 1^ inch, 2:^ inches, losing the seal three times in the nine. Another trial, under similar conditions, showed a loss of the seal three times in five. (9) "A vent pipe, one foot long, and one and a half inch diameter, was then applied at the crown of the trap. Ten pailfuls were emptied to favor a loss of water by momentum, but no appreciable loss of water occurred. " In order to eliminate from the last two experiments the possible effect of the offset in the main pipe directly under the connection of this branch, the same experiment was tried on the floor below, at ' Water- closet No. 2,' with essentially similar results, indicating that the offset did not modify the case percejDtibly. (10) " The effect of excessive lengths of vent pipe was experimented on with the result that, under conditions which indicated perfect security, with a pipe one foot long and one and a half inch diameter, on a four- inch trap, a coil of pipe fifty feet long coTipled to the vent rendered it inefficient once in eight trials, the trap having two inches seal being siphoned in this case, and lost one inch of water three other times out of the eight. "In another case where a short vent of one inch diameter seemed to be quite efficient, a coil of one-inch 25ipe with a length of twenty-eight and a half feet being coupled to it, rendered the vent of apparently little use, for the trap lost its seal at every trial. (11) "In order to test the effect of a partial closing of the top of the soil pipe, a piece of pasteboard was laid over it, having a hole of only two inches diameter. Such a stricture is often produced above the roofs of buildings in cold climates by the formation of ice through condensation of the vapor of water which rises with the air through the soil pipes. It was found that it was much more difficult to retain the water in the traps in all cases under this condition, except where special vents were applied EEMOVAL OF HOUSE- WASTE. 495 to the traps themselves. In sucli cases the strictui-e aloove described, at the top of the soil pipe, seemed to produce no appreciable effect. "We -will next consider the loss of water in traps by the flow past them fi'om above through the main into which they discharge. " C. Experiments ivith a Two-inch Waste-pi];>e, open at the Top. (1) "A trap of one and a half inch calibre of S-form, having four and one-fourth inches depth of seal, and having strips of glass inserted in its sides where the lead w^is removed, was apphed at the branch marked Gr on the plate. The plug connecting with the two-inch waste was then drawn from the bath-tub on the floor above and the water allowed to run a few seconds. The water in the trap was found to have fallen 4^ inches. The next trial destroyed the water seal with a flow of ten seconds. A third trial produced the same result in four seconds. "Five pailfuls of water were then poui'ed in succession into the hopper at (e) on the third floor, with this result : The seal was twice entirely lost, and for three times the water was lowered 4^ inches, leaving only i inch seal. (2) " This deep trap was then removed and an S-trap of same calibre applied in its place, vdih glass strips in its sides and a vent-hole one inch in diameter on its crown. Five pailfuls in succession were poured into the hopper above with no percejotible loss of water in this trap. Its water was agitated less than -J inch. (3) " The vent-hole was then half covered, and the experiment repeated ^\ith scarce a perceptible loss of water. (4) "The vent-hole being Avide oiDen, the bath plug was withdrawn for twenty seconds. The water in the trap oscillated about ^ inch, but was not lowered perceptibly. (o) "This trap was removed and a Cudell trap substituted, such as is shown at S on the plate, with no air- vent in it. The bath plug above was raised for ten seconds, and the trap was found to have lost all its water. The plug was raised again twice for six seconds each time, and the trap twice again comjDletely lost its water seal. Three pailfuls of water were emptied at the hopper in succession, and the trap lost its water seal each time. (6) "This trap was removed and a Bower's trap substituted without special air vent, such as is shown at T on the plate. The plug was drawn from the bath above for fifteen seconds, and the trajD was found to have lost 1-^ inch of water, leaving about yV inch water seal. A second and a third trial of the same flow without refilling the trap, left less than Jg- inch of seal. Air was now readily sucked up through the trap by the mouth, in spite of its ball, which was new and clean. On filling the trap again and pouring a jDailful into the hopper above, f inch seal was left. Two pails more, without first filling the trap, left about :^ inch seal. The hop- per was then filled by a pailful of water and discharged by lifting a plun- ger, and -^ inch seal was left. (7) " This trap was replaced by an Adee trap, such as is shown at Q on the plate, having 1^ inch seal. The flow from the bath above destroyed the seal in ten seconds for three trials in succession. Three successive pailfuls of water emptied at the hopper above left from -^-^ to -^ inch seal after each. 496 AMEKICAN APPENDIX TO PARKES' HYGIENE. " D. Experiments icith a Four-inch Waste or Soil-pipe, open at the Top. (1) " The foiir-inch trap at (g) on tlie plate, having two inches depth of seal, was observed. The vent-hole in the trap was at first closed. The discharge of a pailful of water at the hopper above lowered the trap water y^ inch. The simultaneous discharge of the hopper and water- closet above lowered the trap water 2y\ inches, destroying the seal. The discharge of the hopper while the bath waste was flowing, lowered the trap water 2Jg- inches and broke the seal. The discharge of the water closet above, six times in succession, lowered the trap water respectively |-J inch, 1^ inch, \ mch, 1\ inch, | inch. It]- inch. The discharge of the water- closet, and hopper, and bath together, six times in succession, lowered the trap water from 2 f^^ inches to 2^ inches, destroying the seal every time. (2) "The vent-hole, 1.^ inch diameter, in this trap Avas then opened, the water-closet, hoppei", and bath were then discharged simultaneously ten times in succession, with the loss of only ^ inch of water from the trap in any ins';ance. (3) " This same experiment was twice repeated with the top of the soil-pipe closed, showing a loss of only f inch of water from the trap in any case. (4) " The water in the large trap at (J) on the plate, was obser\-ed with discharges of water from above, similar to those noted in the last three ex- periments, and ^^ith results so essentially similar that they are hardly worth reciting in detail. (5) "An 8-trap of 1^ inch cahbre and 1|- inch depth of seal was at- tached to the branch marked J on the plate, on the second floor, with no vent in the trap. Water was discharged ten times in succession from the bath and water-closet above, for periods of from five to eight seconds each. The trap was unsealed four times and lost from f inch to 1^ inch of water at the other six trials. (6) "The same experiment was repeated with an opening in the crown of the trap 1^^ inch diameter, with loss of water in the traj) as follows : \ inch, few di'ops, ^ inch, ^ inch twice, few drops twice, ^-g twice, few drops. (7) " A Bower's trap was attached at the same place, with no au'-vent in it. The water-closet above was discharged while the bath waste was running ten limes successively. The trap lost its water seal four times and lost at the other six trials from \ inch to 1:^^ inch of water, (8) "A Cudell trap was then substituted at the same branch marked J. The water-closet was discharged above while the bath waste was flowing ten times in succession. Nine times the water was all taken out of the trap and once there was about ^ inch left. (9) " A round trap, having 24- inches seal, as shoAMi at E, was then sub- stituted at this branch J. The discharge of Water-closet No. 1 lowered its water ^ inch. The discharge of the same closet and the hoj^per together lowered it f inch. Further trials of this trap showed that the discharge of the largest volumes of water jDossible at once from the three fixtures above could not unseal it, for though quantities of air were drawn through it, as seen through the glass in its sides, there was so much space for the air to pass by the water that the seal always remained efficient. It would be instructive to try such a trap after it had been encumbered with grease and other rubbish, as is often the case, and where this space for aii" to pass by the water might pei'haps not be found. EEMOTAL OF HOUSE-WASTE. 497 " Before deducing any rules for practice from these experiments, it must he remembered that they were made with new, clean, enamelled pipes, whUe those in ordinaiy use are always more or less encumbered with scales and tubercles of rust, and with the gTease and shmy coating deposited by the sewage. Even in vertical j)ipes such collections often reduce the diani- eter ^ of an inch, thereby reducing the sectional area of a four-inch pipe about 124 per cent, and of a two-inch j^ipe about 23 per cent. ; while in sloping waste pipes, like those under wash-trays and bath-tubs, the accu- muliition of sohd matter from the sewage often amounts to a permanent occupation of one-half or thi-ee-foiuths of the whole section. '■It needs but a ca'sual reference to the above experiments to prove what is generally known and admitted ah-eady, that the difficulty of retainin"- water in traps increases as the size of the waste pipe decreases, so that we must expect, -nith pipes that have been used for any considerable period, much more tendency in the traps to lose theii' seal by unecjual air pressure than in the cases recorded above under conditions which are otherwise similar. Two causes combine to produce this result, viz. : The smaller pipe is filled by a less volume of water, which acts like a piston as it i^asses downward, while the ah- that follows from the vents above finds in the smaller pipes less room to flow in and a consecjuent increase of friction, which, by impairing its velocity, leaves the unequal pressui-e which we complain of. '•Moreover, there are various conditions afi"ecting the stability of water in traps which may not have been foreseen and covered in these experi- ments. The various results actually arising when repeating the same experiment under conditions apparently identical show how unsafe it is to make general deductions from a small number of trials. " These variations may be accounted for in pari by the various jDaths taken by the water when jDoui-ed at different times fi'om one vessel to another, and when running down a vertical pipe. There is always a tendency to follow a spii'al course. "When such a twist is given to the water at the start, in the hopper, it generally checks the velocity so as to prevent the unsealing of the trap attached to it. "When occuiTing in the vertical pipe, as it passes by the connections of other branches, it makes a great dilierence whether the path of the spkal happens to hit exactly across the opening of such a branch, or happens to pass on the other side of the main. "It would rec|uire much more time and labor than we have spent upon the subject to exhaust any considerable part of such possible variations which are hkely to occur in daily practice. The relative size and position of the difterent branches, the cjuantities of water passing through them, and the endless number of combinations of flow from different fixtures which occui' daily in any large house or hotel ; all tend to vary the result to a degree which should induce a piiident man to allow a large margin on the side of safety. The risks are known to be considerable in case of ex- IDOsui'e of untrapped di-ains in dwellings. It should also be remembered in this connection that we live in a climate where artificial heating of houses, varm chimneys, and the careful closing of wall and window cracks, combine to produce a decided pressure of au' from without the house inward, act- ing thi'ough all our house-di-ains, through several successive months every yeai', and that we know of no method as yet so satisfactory for resisting this pressui-e as the use of the water-sealed trap. We are aware that a large number of ingenious devices ha's-e been introduced to supplement the water-seal by mechanical valves with moving cups, balls, and flaps, but we Vol II,— 33 498 AMERICAN APPENDIX TO PARKEs' HYGIENE. have never seen one of these devices which could be rehed upon to shut out air after the apparatus had been used and defiled for a few months by a flow of ordinary house-drainage, whether from laundry, kitchen, or lavatoiy. Conclusions and Recommendations. " When hoppers are used for the emptying of slops, having a trap below the flow, it is difficult to preserve the seal in the ordinary form of S-trap even by a vent-pipe attached thereto. The momentum of the falling water helps to do the mischief. An abrupt change of direction may impair this momentum. But since it is manifestly useless to try to control the direc- tion in which the water is emptied into the hopper, we should endeavor to check it by the form of the apparatus. . . . " When a short hopper is used for emptying slops, with a trap above the floor, though the momentum of the falling water is considerably reduced by the diminished distance through which the water falls from the pail to the trap, there is still no security for keeping the water in the trap, unless supplied by a special air-vent. This should be at least one and a half inch in diameter, if more than a few feet in length, and even larger if passing to other floors above. " Other forms of tx-aps which, like the one referred to in the Experiment D (9), might save and retain their water by means of a lateral expansion of their basins, are objectionable, owing to the amount of filth which they re- tain, subject to decomposition. The ordinary S trap alone, with ample au'-vent, is therefore recommended for use under water-closets, and also for all other fixtures where its proper ventilation can be secured within reasonable limits of expense. " The above precautions are of more importance and should be observed with greater care when waste-pipes are used of smaller size than four inches to carry the flow for more than one or two feet in distance. " The difficulties arising' in such conditions are illustrated by the Ex- periments A and C above noted. " Whenever branch inlets are connected to a line of waste or soil pipe that is vertical or approaching that direction, above which branches other fixtures are used for discharging water into the same main, there is great risk of losing the water from the traps of such branches whenever the up- per fixtures are used, " No form of trap without special air-vent has come to our notice which is not likely to lose its water-seal under such circumstances, even when the top of the soil or waste pipe is open, except those which, like the round trap, are objectionable for retaining filth. This form of trap shown at R on the plate is largely used about Boston. They Avould be safe if always tight, but have a joint for cleaning purposes which is often leaky. Experts differ according to their individual experiences as to their liability to be- come choked with filth in their upper part. ' " The best and most simple remedy for the siphoning of traps in most cases is undoubtedly to be found in the introduction of air at the normal pressvire at the crown of the trap. The reason for jDreferring the crown to any other j)lace can be found in the above record, see Experiment B (2) ( 3) (4) (5) (6) (7). ' The writer has used a modification of this form of trap with a round bottom, as shown on the cut Fig. 117, which is less likely to retain filth than those with a fiat base. EEMOVAL OF HOUSE-WASTE. 499 Fig. 117. " No definite rules can be given for the size and length of vent-pipes. Yet it may be said that it is not safe to trust to a vent-pipe of less size than that of the trap it is to serve until we get above two inches in diameter, ex- cept they be of only a few feet in length be- fore they join those of a larger size. The greater efficacy of a vent applied directly at the trap, as compared with the air-sup- ply through the top of the main soil-pipe, is shown by Experiments B (11) and D (2) and (3). " There is still another risk arising from change of air pressure in drains, besides that of siphoning traps. The lat- ter is the result of lack of pressure, while an excess of pressure is also to be avoid- ed. The following experiment illustrates this point : It is applicable to all house- drains having an exterior main trap, or discharging into a cesspool at a point below the water-line by a dijDiDing inlet pipe, as is often done for the sake of checking the back flow of gas from the cesspool. The trap at the lower end of the system, at the point marked V on the plate, was filled with water, and the air inlet just above it was capped. The trap at (n) on the basement floor was then filled with water, and a pailful emptied at the hopper on the third floor, connecting to the four-inch main. The air was so compressed ahead of the falling water that it was forcibly blown out at the trap (n), carrying with it a good deal of water, showing how foul air from a drain can thus be ejected into the apartments of a house in considerable volumes. The fixture connected to such a trap may generally be able to collect and re- store to the trap enough of the water expelled to save its seal, and thus no apparent defect would be found, unless the blowing out of the foul air through the trap happened to attract attention. " On removing the cap from the air-hole near V, and repeating the ex- periment, no apparent disturbance followed in the trap (n). " Another experiment was tried to illustrate the retarding effect of fric- tion and the consequent change of pressure in small waste-pipes, viz. : An ordinary S trap of 1^ inch seal, and 1^ inch calibre was attached in the base- ment to the branch marked U of the two inch waste pipe. This represents a combination frequently occurring in the waste-pipes of pantry sinks. This trap was filled with water, and a pailful emptied into the two-inch waste on the third floor above. The air was forcibly blowTi out of the trap at U by the compression of air ahead of the descending charge, even when the four-inch air-hole near V was open in the main below. This result was plainly due to the friction caused by the air rushing through the abrupt bend at the connection marked Z. It shows the risk incurred by branch- ing small waste pipes into one another when used on several floors, and the impropriety of using a quarter bend and T branch at Z, instead of a Y branch. " Though condemned by English authorities, it is doubtless a safer way to connect the waste-pipes of baths, bowls, etc., used on upper floors, directly to the large soil-pipe by Y-branches, as near as practicable to the fixtures drained, than to erect long lines of smaller-sized wastes separately for such purposes. Certainly the larger the pipe, the less is the risk of any abnormal air-pressure occurring by its use so long as the wastes are not likely to become encumbered seriously by accretion of solid matter. 500 AMERICAN APPENDIX TO PARKES HYGIENE. " The l)ro^ision of separate wastes for baths, etc., all the way to the base- ment is eousidered important in England, probably because of a dislike to make inlets in the soil-pipe used for water-closets. But the risks arising from the use of a small-sized waste through such distances are thus proved to be considerable, and should not be ignored ; while those ai-ising from the common use of a four or five inch pipe for water-closet and general refuse water on sevei-al floors may have been overrated in England." Grease Interceptors. Wherever kitchen and pantiy sink drains which are used for the dis- charge of water from the washing of table dishes cannot be provided with a xery rapid fall, the congealing of the gi'ease is hkely to form a deposit on the inside of the di'aiu which often obstructs it entirely. The use of a larger pipe does not remedy the difficulty, for the quantity is often sufficient to till a drain eighteen inches in diameter in a few months. The only efficient remedy is to apply an intercepting tank, as near the sink as possible, so as to avoid the filling of the drain with grease between these re- ceptacles and the sink. The best material of which to coustmct the tank is Portland cement, mixed with clean sharp sand, and moulded in forms as for large sewer pipes. They are now constnicted for the pm'pose in Boston, with a bowl-shaped bot- tom inside and flat bottom outside, moulded in one or two pieces, to accommodate the desired depth below the surface, and fitted with an iron flange and cover. The outlet jDipe is made of a four-inch soil-pipe T bi^anch, which admits of being cleaned out from above. The gTease then congeals and floats on the surface, and can be removed when convenient. This aiTangement is shown in Fig. 118. The outlet for water being immersed several inches below the surface, the water is allowed to flow ofl", while the grease accumulates on the toji of the standing water. Fig. 118.— a. House-wall. B, Ventilation Pipe. C, Inlet. D, Outlet. IiiPORT.^NCE OF Simplicity. One of the most frequent faults to be found in the planning of the plumbing and drainage of American houses is in the multiplication of fix- tures for the convenience of the inmates, scattered without consideration and without sufficient reason all about the house. It is difficult to render such aiTangements safe without a large outlay in safeguards, and even then an unnecessary risk is incuiTed by lack of simplicity. It is impoi-tant to REMOVAL OF HOUSE-WASTE. 501 limit these conveniences to the immediate vicinity of the soil-jDipe, and to avoid all drain or waste pipes passing in a nearly horizontal du-ection. A common error is illustrated by the annexed cut (Fig. 119), where a wash- bowl waste is connected with a water-closet trap, several feet distant, by a Fig. 119. pipe under the floor, difficult of access, and so nearly horizontal as to in- sure its being soon fiUed by a deposit of slimy filth, thi'ough which the water finds its way slowly and with difficulty. Such an arrangement can never be satisfactory. The bowl should be placed close to the closet, and should drain into the soil-pij)e by a separate branch below the water-closet trap, hav- ing a special trap under the bowl itself. One of the most comphcated and objectionable pieces of apparatus is the old-fashioned and largely used "pan" water-closet, w^hich is now, however, being generally superseded by various better patterns. Nearly all the new de- vices are better that the pan closet, which is by all means to be avoided. Among the best forms for general use are the simple hoppers with traps above the floor. This position for the trap brings the water it contains in plain sight, and reduces to a minimum the surface hkely to be soiled above the trap-water. Moreover, it diminishes the chance of loss of the trap-water by mo- mentum, an important item. Where to be used by servants, children, or arti- sans, the water-supply should be made automatic, and metered by a waste-sav- ing apj)aratus, as illustrated on the an- nexed cut (see Fig. 120). The weight of the person on the seat is thus made to hft the valve in the bottom of the tani, which should be placed directly over Fig. 120. -Tank with Automatic supply. the closet, and thereby fill the service-box beneath. T^Tien the weight is removed from the seat this valve closes and the lower one opens, dis- 502 AMERICAN APPENDIX TO PARKES HYGIENE. cliarging an ample and definite quantity of water with a sudden dasli, which expels all the contents of the trap below. The ordinary method of flushing hopper closets by a faucet is a miserable makeshift. Even if the faucet is left open for half the time, with the consequent waste of several hundreds of gallons of water per hour, the object sought is not gained, for such a driblet does not properly flush the trap or the drain below. It is a per- fectly useless waste, and leaves undisturbed the filth which may have col- lected in the trap or in the drain below it. FOOD ADULTEEATION. , By E. G. love, Ph.D. Legislation. The first movement toward securing comprehensive legislation against the adulteration of foods and drugs in this country was made in 1879. A com- petition for the best essay on the subject of food and drug adulteration, with drafts of suitable bills for its prevention, was instituted by the Sanitary Engineer, under the direction of the National Board of Trade. Prizes amounting to $1,000 were offered for the best essays, which sum was placed at the disposal of the Board by Mr. F. B. Thurber, one of its mem- bers. The committee of award being also required by the terms of the competition to frame laws suitable for State and National enactment, was selected as representing the different interests involved. The Committee was composed as follows : Dr. John S. Billings, Surgeon United States Army ; Professor C. F. Chandler, President Board of Health, New York ; Ex-Chancellor B. Williamson, Elizabeth, N. J. ; A. H. Hardy, Esq., Bos- ton ; John A. Gano, Esq., Cincinnati. In October, 1880, several essays, with drafts of laws were sent in, and on the 29th of that month the committee made its repoi't to the Board of Trade. In none of the essays submitted was there any evidence to show that dangerous adulterations existed to any extent in this country. This fact was corroborated by several extensive examinations of food products made about that time, and proved most conclusively to the minds of the Committee that there was no foundation whatever for the statements so frequently made by ignorant persons that our food supply was dangerously adulterated. This same conclusion had been already reached by many persons who had made special study of the subject. The publication of wild and fanciful stories as to poisonous substances found in articles of food, while it may give a certain notoriety to the writer of such fiction, can result only in needlessly alarming the public and in detriment to many commercial interests, and it should be most emphatically condemned. If the substances generally used as adulterants are not positively dan- gerous to health, then the question of food adulteration should be con- sidered, as stated in the Committee's report, more from the commercial than from the sanitary standpoint. The Committee also expressed the opinion that there was more danger to life and health in this country from adul- terated drugs than there Avas from adulterated food, and that any legislation which aimed to correct the one must also deal with the other. This sugges- tion was very pertinent at that time, inasmuch as a bill had been previously introduced in Congress, which was entirely unsuitable and inadequate for the purpose, and which, moreover, referred only to articles of food. If the adulteration of food is considered simply as a commercial matter, the execution of laws enacted for its prevention would naturally devolve 5 04 AMERICAK APPENDIX TO PAEKEs' HYGIENE. upon a commercial rather than vij)on a sanitary organization. Such is the case in Canada, where the enforcement of the Adulteration Act is placed upon the Department of Inland Eeveuue. Inasmuch, however, as the in- dividual States in this country have no similar department, and as the projDosed legislation should include drugs as well as food, it was thought expedient by the committee to entrust the execution of the laws for this object to the State Boards of Health ; and where such boards do not exist it was suggested that they be created by independent legislation. " The questions involved are in a high degree technical and require special training in those charged with admin istenng the law ; " but it was the ojiinion of the committee that the existence of such health authorities might be taken for granted. While the competition did not result in furnishing the draft of an act which met the views of the committee, many suggestions were obtained, and the committee subsequently presented to the Board of Trade di'afts of National and State acts. These drafts, together with the committee's re- port, were approved by the Board of Trade on December 15, ISSO, and resolutions were adopted directing the President and Secretary of the Board to transmit to the United States Senate and House of Representatives copies of the report of the coinmittee and of the draft of a national act, requesting in behalf of the Board the passage of the same. Copies of the report and drafts of acts were also sent to the State Boards of Trade with the request that they use their influence to secure the desired legislation. The bill introduced in Congi'ess was subsequently modified by excluding all reference to inter-State traffic, and by the sub- stitution of the " Secretary of the Treasury' " for the " National Board of Health." In this form it was reported by the Committee on Commerce of the House of Eepreseutatives, but up to the j)resent time it has not be- come a law. In 1881, three States— New Jersey, New York, and IMichigan — passed laws to prevent the adulteration of food and drugs. New Jersey. — In New Jersey the law was approved March 25th, and went into effect thirty days later. The bill, as passed, w-as the same as that recommended by the National Board of Trade for State enactment ; and its pi'oy^sions correspond in general with those contained in the bill introduced in Congress. The enforcement of the law was placed in the hands of the State Board of Health, and soon after its passage the board •appointed eight persons as a " Council of Analysts and Chemists." Circu- lars were sent to the local boards of health, and to physicians and others, asking for any information in their possession of cases of poisoning or in- jury to health hy the use of improperly prepared or adulterated foods anc? dnigs. A series of examinations was commenced by the anal^'sts, the re- sults of which were subsequently published.' The Legislatiu-e whicK passed the law rendered its enforcement practically inoperative by the appropriation of only $500 for carrying out its provisions. Early in 1883 the law was amended in several important particulars. One section of the amended act, referring to the disposal of penalties, reads : "In case of any suit not otherwise provided for, the penalty shall be paid to the person bringing the suit." This is an un^dse pi-ovision, as it encourages prosecu- tions for violations of the law, with no other object than the j)ocketing of the penalty by private indi^-iduals. The report of the Board of Trade committee, ah'eady referred to, distinctly says that " under no cu'cum- ' Fifth Annual Report of tlie Board of Health of New Jers'^y, 1881. FOOD ADULTERATIOiSr. 505 stances should fees or moieties to informers be allowed." Another section gives power to any officer of any local board of health to inspect any article of food or diiigs, whether offered for sale, " or whether in transit or other- wise." xls local boards of health are liable to have officers who are in no way Cjuahfied for snch inspections, and who might make them for the sole jDui'pose of obtaining the tine imposed, in case of conviction, it is \erx clear that this section gives too much power to individuals ; and it is altogether likely that sooner or later cases will arise under this section which will bring disrepute upon the law and great annoyance to commercial interests. The amendment is to be commended in one particular, in that it allows the Boai'd of Health to expend §1,000 annually in carrying out the pro- visions of the act. It has been stated by one of its officers that it is not the intention of the Board of Health "to chase every commercial fraud," but "to look after adulterations harmful to health." If this be true, the commercial interests, which were largely considered by those who drafted the original law, will receive little protection in New Jersey ; and the consumers and honest tradesmen, in whose interest the law was presumably enacted, must look elsewhere for that protection fi'om commercial frauds which they had every reason to expect would be furnished by the State Board of Health. The first case brought to trial under the New Jersey law was in May last, in which a person was convicted of selling skimmed milk. So far as we know, this is the only case u]d to the present time. New York. — The legislation against food and drug adulteration in New York commenced by the introduction of a bill in the Legislatiu'e during the winter of 1880-81. The bill was passed and became law on June 2, 1881 ; but it did not go into effect until ninet}' days later. The bill ' was that recommended by the Board of Trade, and jDlaced the enforcement of the act upon the State Board of Health. The sum of §10,000 was ap23ro- priated for caiTying out its provisions. It is a fact worthy of note here that the passage of this law was largely due to the support and co-op)eration of the leading food and di'ug manu- factui'ers and dealers. The first step taken by the Board was the aj^pointment of eight exj^erts, including chemists and pharmacists, who were asked to make examinations of the foods and drugs sold in the State, for the pui-pose of ascertaining to what extent adulteration existed, and also to determine the natui-e of the adulterants employed. The supeiwision of this work was placed in the hands of the Sanitary Committee of the Board. To each analyst was assigned a group of foods or drugs for examination, it being the opinion of the committee that more could be accomplished in such j)reliminary work in this way than by giving to each one all the samples from a certain locality. The samples were collected by two inspectors. The reports ' of these examinations fully corroborated the existing evi- dence, that most of the adulterations of food were such as to affect the pocket more than the health. Unwholesome adulterants were foimd, but none which were really poisonous. On the completion of this preliminaiy work, the Board dirided the State into three districts, and appointed four public analysts and one inspector, to each of whom a fixed salary was paid in lieu of all fees. ^ A copy of this act will be found at the end of this article. ^ See Second Annual Eeport State Board of Health of Xew York, 1882. Abstracts of the same, The San. Eng., vol. v., March, 1882. 506 The actual work of the Board in the enforcement of the adulteration law commenced in the summer of 1882. The report of the Sanitary Com- mittee for 1882 shows that up to the close of the year 286 samples of foods and dinigs had been submitted to the public analyists for exanjination, of which 19-1 had been reported upon. Of 119 samples of food, 50 were found adulterated ; while of 75 samples of drugs, 32 were adulterated. During December, 1882, prosecutions were commenced in twenty-four cases for violations of the law. These included seventeen cases for selling cream of tartar adulterated with terra alba, starch, etc., to the extent of from thirty- seven per cent, to ninety-five per cent. ; two cases of coffee adulterated with chicory and burnt peas ; four cases of mustard adulterated with from forty per cent, to seventy-one per cent, of floui* ; and one of precipitated sulphur, containing thu'ty per cent, of sulphate of lime. One of the cream of tartar and one of the mustai-d cases were made test cases and convic- tions secured in l^oth instances. The defendants in the other mustard cases and in the coffee cases pleaded guilty and paid the penalty. The cream of tartar case was appealed, and the decision reserved, prin- cipally on the ground that criminal intent had not been proved. The Board of Health did not carry this case to a higher court, and the other cream of tartar cases were never brought to trial. The action of the Board, however, resulted in calling public attention to the fact that adulteration existed, and also in very materially improving the quahty of certain articles of food, as was shown by subsequent examinations. As another result, the Board of Health held a conference with the manufac- turers, for the jDurpose of ascertaining their views relative to the sale of mixtures, such as mustard and flour, coffee and chicoiy, etc. It was the opinion of the manufacturers present at this conference that the com- ponents of a mixture, as well as the percentage of the princii)al or charac- teristic constituent, should be printed upon the label ; but not the per- centage of each constituent present. The Board subsequently passed resolutions permitting the sale of mixtures of mustard and coffee, which resolutions received the Governor's aj^proval in March, 1883, and so be- came law.' The action of the Board of Health in instituting proceedings against the retail grocer instead of the wholesale dealer or manufacturer was somewhat criticised, as being of the nature of persecution, and on the further ground that the grocer, having purchased his merchandise in good faith, sujjposed it was unadulterated. This, of course, is a very important matter in the enforcement of any food adulteration law. Legal proceed- ings should be brought against the manufacturer, if possible, but failing in this, against the wholesale merchant, or lastly against the retail dealer, who may or may not know the exact nature of the goods he sells. The manufactiu^er is the most responsible, and should first be brought to ac- count ; but this does not free the retailer from responsibility or exempt him from prosecution in case he violates the law. It is often impossible to reach the manufacturer except through the retail dealer, and while the Board of Health would gladly prosecute the former, such a course is, as a rule, impossible, from the fact that the retailer is unwilling to testify against the manufactui'er. To purchase an article in very small quantities from the manufactiirer or wholesale merchant, if possible at all, would arouse suspicion, and doubtless result in the purchaser getting the genu- ine and not the adulterated article. The Board can hardly be expected ' A copy of these resolutions will be found at the end of this article. FOOD ADrLTERATIOlSr. 507 to buy a barrel of flour or a firkin of butter in order to get a few ounces for analysis. The prosecution of the retailer, therefore, is in the majority of cases, the only practicable plan for those charged with the enforcement of the law, unless the retailer himself will become a witness for the prosecution. The public have a right to assume that the merchant who offers goods for sale knows the nature of the goods he sells. It is a part of his busi- ness. Some allowance must, of course, be made in the case of articles which require chemical examination to reveal their nature ; but most grocers would be very indignant if told that they could not tell whether mustard was one-half- flour, or pepper two-thirds sawdust. Many will assert that they can distinguish genuine butter from oleomargarine by the taste, and yet, if prosecuted for selling the latter for the former, would say, or allow it to be said for them, that they did not know it was oleo- margarine. The retail grocer can always protect himself by purchasing his stock of reputable dealers, or secure himself against pecuniary loss by demanding a written guarantee as to the quality of the goods he buys, and thus avoid all probability of prosecution. As to proving criminal intent it is absolutely impossible to do so in very many cases which might arise in the enforcement of an adulteration law, notwithstanding that the prosecution might be morally certain that the dealer knew just what he was selling. Judges Cockburn and Blackburn have both decided, in adulteration cases brought before the Court of Queen's Bench, that it was not necessary to prove criminal intent in such prosecur tions, and that the gTocer is supposed to know what he sells. These remarks relative to the enforcement of the Food Adulteration Act in the State of New York will apply, to a greater or less extent, in States where existing or future legislation may render similar prosecutions essen- tial. The operation of the law in New York State has demonstrated that its enforcement should be placed in the hands of one person, to whom the Board of Health should give sufficient power to enable him to act promptly in an emergency. Moreover, this work involves a certain knowledge of technical and analytical chemistry for its intelligent and energetic per- formance. The director of the work should be qualified to say what kind of an analysis is necessary, and be able to judge of the value of an analy- sis with a view to prosecution ; and he should also be so thoroughly imbued with the importance of the work, that he will perform the duties imposed with promptness and energy. Anything short of this will result in the ac- complishment of little practical good in the suppression of adulteration. It is also important that counsel specially qualified for the work be employed to conduct prosecutions. The funds appi'opriated by the last Legislature for enforcing the Adul- teration Act were withheld in consequence of the Governor's veto. This partly accounts for the apparent inactivity of the Board of Health in carry- ing out the provisions of the law at the present time. The enforcement of the food law may be said to have passed the experi- mental stage in New York State, and with energy, discretion, and the needed funds it can be, and should be felt in the suppression of adulteration. Michigan. — In June, 1881, Michigan passed a law to prevent the adul- teration of food, drink, and medicine. The act differs entii'ely from that passed in New York State, and recommended by the Board of Trade. The first defect noticeable in the law is that no one in particular is entrusted 508 AMERICAN APPENDIX TO PAKKEs' HYGIENE. with its enforcement. It is made the cTuty of the prosecuting attorneys of the State to appear for the people, but no one is likely to commence pro- ceedings for violations of the law, unless it be some injured or aggi^ieved individual. Moreover the law does not contain any detinition of adiiltera- tion, and provides for no standards of puiity. It is evidently aimed more especially at glucose and oleomargarine, as these are the only substances mentioned in the act. The law should be so comprehensive as to avoid all necessity for the mention of any particular articles of food. The statutes of veiw many States contain laws which were directed against some one article of consumption, but which, for want of some pro- vision for their enforcement, have long been so much dead matter. We have heard of no cases being brought under this act, and doubt whether Michigan will ever be any better off for its passage. JIassachui