Columbia ^nibers;itsK^crra*u 
 intijeCUpofi^etogorfe ^^ 
 
 College of S^fipikmm ant ^utgeoncf 
 
 <@iben bp 
 
 iHigjf <^us{£fie ClUsJon 
 m memorp of 
 
 r. €tntsit Miliiam ^u^al 
 
 1918 
 
A. C. ABBOTT, M.D. 
 
Digitized by tine Internet Archive 
 
 in 2010 with funding from 
 
 Open Knowledge Commons 
 
 http://www.archive.org/details/hygieneoftransmiOOabbo 
 
THE HYGIENE 
 
 OF 
 
 Transmissible Diseases: 
 
 Their Causation, Modes of Dissemination, 
 and Methods of Prevention, 
 
 BY 
 
 A. C. ABBOTT, M. D., 
 
 Professor of Hygiene and Bacteriology, and Director of the Laboratory 
 of Hygiene, University of Pennsylvania. 
 
 ILLUSTRATED. 
 
 PHILADELPHIA: 
 W. B. SAUNDERS, 
 
 925 Walnut Street. 
 1899. 
 
COPVRIGHT, iSgg, 
 By W. B. SAUNDERS. 
 
 CLECTROTVPED BY PRESS OF 
 
 WE9TC0TT a. THOMSON. PHILA. W. B. SAUNDERS. PHILA 
 
PREFACE. 
 
 The contents of this book are essentially the subject-mat- 
 ter of a portion of my lectures on General Hygiene at the 
 University of Pennsylvania. 
 
 It is not the purpose of this work to present the subject 
 of Hygiene in the comprehensive sense ordinarily implied by 
 the word, but rather to deal directly with but a section, cer- 
 tainly not the least important, of the subject — viz., that em- 
 bracing a knowledge of the preventable specific diseases. 
 Incidentally, as occasion may require, there are discussed 
 those numerous and various factors that have not only a 
 direct bearing upon the incidence and suppression of such 
 diseases, but that are of general sanitary importance as 
 well. 
 
 In the preparation of this work only the most trust- 
 worthy authors have been consulted, and only those pre- 
 cepts embodied that are now generally accepted by sani- 
 tarians as sound. 
 
 It will be manifest to the reader that a great deal is still 
 wanting to complete our knowledge upon many important 
 phases of the subject, and no effort has been made to dis- 
 guise this fact. 
 
 The frequency with which requests are received for infor- 
 mation concerning the detailed management of transmissible 
 diseases is in part the reason for the publication of this book. 
 
 I trust the work may serve a useful purpose. 
 
 A. C. A. 
 
CONTENTS 
 
 PAGE 
 
 Introduction 17 
 
 Causation of Disease , 25 
 
 Predisposing Causes 26 
 
 Age 27 
 
 Sex 29 
 
 Race 31 
 
 Occupation 37 
 
 Density of Population 41 
 
 Heredity 45 
 
 Season 47 
 
 Exciting Causes 50 
 
 Chemical Causes 52 
 
 Physical and Mechanical Causes 53 
 
 Animal Parasites 53 
 
 Bacteria . . . 54 
 
 The Causation, Modes of Dissemination, and Prevention of 
 
 Special Diseases 63 
 
 Typhoid Fever 63 
 
 Asiatic Cholera 89 
 
 Amoebic Dysentery 97 
 
 Tuberculosis 100 
 
 Acute Croupous Pneumonia , 107 
 
 Diphtheria Ill 
 
 Epidemic Cerebrospinal Fever 118 
 
 Influenza 124 
 
 Bubonic Plague 126 
 
 Suppurative and Septic Infections 133 
 
 Venereal Diseases 140 
 
 Leprosy 14S 
 
 Tetanus (Lock-jaw) 155 
 
 Anthrax 160 
 
 Glanders 166 
 
 Actinomycosis ■ 17^ 
 
 Madura Foot 174 
 
 Small-pox • 176 
 
 Varicella (Chicken-pox) 180 
 
 Measles 181 
 
 15 
 
1 6 CONTENTS. 
 
 PAGE 
 
 Scarlet Fever 1 82 
 
 Whooping Cough 186 
 
 Mumps 188 
 
 Malarial Fever 189 
 
 Yellow Fever 202 
 
 Dengue 208 
 
 Typhus Fever 211 
 
 Relapsing Fever 214 
 
 Rabies (Hydrophobia) . 216 
 
 Diseases due to Animal Parasites 223 
 
 Prophylaxis in General against Infectious Diseases: 
 
 Vital Processes : 
 
 Immunity ; Vaccination and Protective Inoculation ; Antitoxic 
 
 Condition 241 
 
 Chemical and Physical Prophylactic Measures 259 
 
 Disinfection and Disinfectants 259 
 
 Special Chemical Disinfection 277 
 
 Privy Vaults, Evacuations, etc 277 
 
 Water-closets, Urinals, and Sinks 278 
 
 Stables and Cellars 279 
 
 Wells and Cisterns 280 
 
 Disinfection of the Hands 281 
 
 Disinfection through Physical Processes 282 
 
 Disinfection by Heat 282 
 
 Steam 283 
 
 Desiccation 288 
 
 Sunlight 288 
 
 Electricity .' 289 
 
 Mechanical Agitation . 290 
 
 Important Precautions in the Management of Communicable 
 
 Diseases 291 
 
 Isolation 291 
 
 The Sick-room . 292 
 
 Clothing 294 
 
 Excreta 295 
 
 Room Disinfection 296 
 
 Care of the IJody after Death 298 
 
 Quarantine 299 
 
 INL-EX ♦ 305 
 
The Hygiene 
 
 OF 
 
 Transmissible Diseases. 
 
 INTRODUCTION. 
 
 Hygiene is the science that deals with the laws of health, 
 in the broadest sense. 
 
 Practical hygiene, or sanitary science, is the art of pre- 
 serving health (or of preventing disease), and includes a con- 
 sideration of the methods that are employed in investigating 
 the manifold phases of the subject. 
 
 It is obvious that the fundamental points to be considered 
 in the study of hygiene are those bearing upon the conditions 
 under which we live. Hygiene is not so much a study of 
 man as a study of man's surroundings, with the view of 
 determining in how far these are conducive or detrimental 
 to his well-being. 
 
 Among the earliest medical and ecclesiastical writings are 
 encountered laws for the sanitary guidance of man. It is due 
 largely to the inculcation of these precepts, handed down 
 from generation to generation, that we follow particular 
 modes of living and still instinctively avoid certain condi- 
 tions then thought to be harmful. Probably the most 
 familiar of the early writings on the subject are the laws of 
 Moses for the guidance of his people. Since practically 
 nothing was then known as to the direct causation of disease, 
 these laws were of necessity empirical, though the measures 
 recommended for preventing the spread of contagion, for 
 cleanliness, for the killing of animals for food, for the isola- 
 tion of infectious maladies, and for the renovation of dwell- 
 2 17 
 
1 8 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 ings inhabited by contagious diseases are alone sufficient to 
 warrant the belief that they were formulated from close 
 observation and trustworthy experience. 
 
 The older writings on hygiene, and in fact many of those 
 of comparatively modern date, were in the main speculative, 
 representing the dictates of instinct and intuition. They 
 were, nevertheless, of undoubted benefit to those Avho heeded 
 them and, in so far at least as the Jews are concerned, were 
 unquestionably instruments in repeatedly shielding them from 
 the rax-ages of pestilence. 
 
 That the importance of personal and municipal hygiene 
 was fully appreciated by the earlier civilizations generally, 
 there is abundant evidence. The question of public health 
 was one of vital importance, and their desire and ability to 
 carry their precepts into practice have been abundantly dis- 
 covered through the researches of the archeologist. In 
 many instances their devices for baths, water-supplies, dis- 
 posal of sewage, and for light and air left little to be desired. 
 
 With the progress of time, the growth of communities, and 
 the demands of modern life, it became evident that the earlier 
 sanitar}^ codes must be recast to meet the requirements of 
 newer conditions. The older regulations were based, as has 
 been said, in many important particulars, upon speculation 
 and erroneous conceptions ; though it must be admitted that 
 they erred more frequently on the right than on the wrong 
 side. 
 
 About the middle of the present century it was realized by 
 tho.se who have done most to place hygiene on a sound basis 
 that, through the application of methods of precision to the 
 study of man and his surroundings, much light could be 
 thrown upon many phases of the problem that had hitherto 
 been but imperfectly understood. In consequence, through 
 the utilization of chemical, physical, histological, stati.stical, 
 and bacteriological methods, the empirical hygiene of the 
 past has in part given place to the more exact hygiene of 
 to-day. In the light shed by such trustworthy methods of 
 analysis we are in a favorable position to interpret and appre- 
 ciate the me^uiing, the value, and the wisdom of many of the 
 
INTRODUCTION. 1 9 
 
 laws and customs that were in vogue in earlier times for the 
 regulation of health and disease. 
 
 The foundation of modern hygiene is laid in the scientific 
 investigations of von Pettenkofer on ventilation and heating, 
 on the relation of soil-moisture to health, on the physical 
 properties of clothing ; and in those of himself, associated 
 with Voit, on the chemistry of respiration and general nutri- 
 tion, and the chemico-physiological values of food-stuffs in 
 the process of alimentation ; and in the brilliant, epoch- 
 making researches of Koch upon the etiological relation of 
 micro-organisms to disease. With the impulse given to the 
 work by the intelligent deductions of these pioneers in modern 
 hygiene there was a development in our knowledge along all 
 the manifold ramifications of the subject, and to-day the field 
 of hygiene has assumed such vast proportions that only a 
 rare intellect can master in detail its numerous phases. 
 Indeed the subject is already divided into its specialties, and 
 complete works on hygiene are no longer attempted by single 
 individuals, but are rather edited as systems of monographs, 
 each contributed by individuals who devote their time exclu- 
 sively to the study of this or that particular branch of the 
 subject, and who, therefore, have the special knowledge neces- 
 saiy to clear and complete enunciation. Not only has the 
 development of knowledge upon hygiene alone been veiy 
 conspicuous but, through special investigations of hygienic 
 significance, its influence has been widespread, and much 
 light has been thrown upon topics of general medical 
 interest. 
 
 It is manifestly inadmissible longer to connect the teaching 
 of hygiene with that of any other branch of medicine. It 
 has become a science of itself, and as such should be in the 
 hands of those who have undergone the special discipline nec- 
 essary to appreciate fully the nature and importance of the 
 problems involved. The time is past for the student to 
 receive adequate instruction in this work from the " Pro- 
 fessor of Obstetrics and Hygiene," of " Dermatology and 
 Hygiene," of " Materia Medica and Hygiene." as has been 
 the case for so long a time in many institutions of learning. 
 
20 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 The times demand that the teacher of this department of 
 work be one who has been systematically trained in its 
 various departments, not of necessity to the extent of being 
 master of each, but certainly as master of some, and in gen- 
 eral to a degree that will enable him to comprehend and 
 elucidate fully the problems that present. 
 
 W'h}' should a physician trained to cure the sick equip 
 himself with a knowledge that he is to employ in preventing 
 sickness ? Why should a physician practise preventive med- 
 icine and follow the precepts of hygienic teaching ? are ques- 
 tions that are occasionally asked. One might as readily ask, 
 why does one experience the impulse to rescue from danger 
 a stranger, in whom he has no direct interest ? Laying aside 
 the question concerning his functions as a physician, there is 
 every moral reason why he as a man should use his best 
 endeavors to lessen suffering and save life, in so far as it lies 
 in his power to do so, and this too regardless of whether it is 
 to be of direct profit to him or not. 
 
 In the second place, there are material reasons for a phy- 
 sician's having a fairly accurate knowledge of the advances in 
 preventive medicine. His patients demand it. With the uni- 
 versal progress in general education the public is no longer 
 satisfied that a physician enter the house, prescribe his medi- 
 cines, and depart ; they desire more : they wish to know the 
 nature, the origin, and the cause of the sickness, the most 
 like!)' channel or channels through which the disease was 
 contracted, and the most reliable means of preventing its 
 recurrence or spread. If the doctor cannot promptly supply 
 reasonable answers to these cjuestions, he need not be sur- 
 prised if his employment be given to someone else who can. 
 
 In the third place, for his own enlightenment and personal 
 welfare the physician should be f^miiliar with sanitary laws, 
 especially tho.se concerning the causation and spread of dis- 
 ease and the means of prevention. He should be familiar 
 with the modes of infection, the methods of disinfection, the 
 means for the isolation of the sick, and the general rules of 
 prophylaxis in the management of contagious diseases. He 
 should be familiar with the channels through wiiich he him- 
 
IN7 'R OD UCTION. 2 1 
 
 self may become infected, or the means by which he may 
 serve as a carrier of infection and the proper precautions for 
 preventing such accidents. As an educated physician he 
 should know, and as a conscientious physician he should 
 practise these precepts for the good, not only of his own 
 patients, but of the community of which he forms a part. The 
 medicine of the period tends more and more in the direction 
 of prevention, and if the physician proposes to keep himself 
 abreast of the times it is imperative that he be in touch with 
 the advances along these lines. While ignoring the subject a 
 new medicine grows up about him, and he is suddenly aware 
 of his presence in an atmosphere unfamiliar and wholly 
 uncongenial — an atmosphere that he does not appreciate, and 
 with which he experiences no intelligent sympathy. 
 
 From time to time the teachings of hygiene are assailed by 
 hostile attacks, and proof is demanded that the practice of 
 sanitary precepts has resulted in the betterment of the condi- 
 tions under which mankind lives, in the prevention of disease, 
 or in the saving of life. While it cannot truthfully be said 
 that every so-called sanitary precaution is beneficial or neces- 
 sary, or that every article in the sanitary code is based on 
 that which is proved to be sound, we can nevertheless combat 
 adverse criticism with an array of evidence that should con- 
 vince the most sceptical as to the importance, yea, the pro- 
 found necessity, of an intelligent sanitary control of the con- 
 ditions under which we live. For instance, to cite a few of 
 the triumphs of hygiene : Until the beginning of the present 
 century the average mortality from small-pox in Prussia was 
 3 per looo of population. In times of epidemics this ratio 
 was commonly very much increased. Since the introduction 
 of compulsory vaccination the mortality from this disease has 
 fallen to its present figure of 0.03 per 1000 of population, 
 and, as Fliigge states, cases of small-pox are now looked 
 upon in many provinces of Prussia as medical curiosities. 
 
 During the seventeenth and eighteenth centuries the 
 annual death-rate from this disease in London ranged from 2 
 to 4 per 1000 of population ; with the introduction of general 
 vaccination it had fallen for the interval between 1883 and 
 
22 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 1892 to 0.073 per 1000. Schulz states that by the calcula- 
 tions of the Imperial Health Bureau at Berlin, based upon 
 the statistics of mortality for small-pox for the periods 
 between 1845 ^'''d 1869, and 1875 and 1885, at least 74,000 
 lives have been saved through vaccination in Prussia alone. 
 
 Reductions in the mortality from this disease analogous to 
 those just cited have occurred in all countries where vaccina- 
 tion has become general. 
 
 During the seventeenth and eighteenth centuries a very 
 large proportion of sickness and death in the navies and in 
 the merchant service was due to scurvy, and no inconsider- 
 able number in public institutions, hospitals, jails, reform- 
 atories, workhouses, etc., were from the same cause. By 
 virtue of proper attention to diet, cleanliness, and habitation, 
 scur\y has practically disappeared from among civilized 
 peoples. 
 
 Typhus fever, also so frequent in former times among the 
 inmates of overcrowded hospitals and other public institutions, 
 has, under modern sanitary conditions, become a rarity. 
 
 By attention to the drainage of soils and the introduction 
 of pure water for domestic purposes, it has been demon- 
 strated that cholera and typhoid fever can be almost elimi- 
 nated. No more striking instance of this can be cited than 
 the remarkable reduction in the typhoid death-rate in the city 
 of Munich. In 1856 the mortality from typhoid in Munich 
 was 2.91 per lOOO of population. At that time the soil of 
 the city was honeycombed with cesspools, and a large part 
 of the water-supply of the city was obtained from wells and 
 pumps sunk in this soil. Between 1856 and 1887 the condi- 
 tion of the city underwent, at several conspicuous periods, a 
 radical .sanitary reform. The cesspools were filled, and the 
 introduction of new ones was prohibited. An elaborate system 
 of .sewers was introduced, pumps and wells were abandoned, 
 and a pure water-supply was brought from a source beyond 
 suspicion of pollution. As a result of all this, the mortality 
 from typhoid fever fell, and in 1887 it had reached the very 
 low ratio of o.i per lOOO c>f poj)ulation, a reduction of about 
 96.6 per cent, in the deaths from this di.sease alone. 
 
INTRODUCTION. 23 
 
 Within less than one year after the adoption of approved 
 methods for the purification of the water-supply of Lawrence, 
 Mass., the death-rate from typhoid fever was reduced nearly 
 59 per cent., and in Chicago the deaths from this disease were 
 diminished approximately 60 per cent, within a year after the 
 domestic water-supply was obtained from a non-polluted 
 source. 
 
 As a result of the proper drainage of soils, a diminution in 
 the frequency of pulmonary, intestinal, and malarial troubles 
 has everywhere been observed. 
 
 These few illustrations, not to mention the advantages that 
 have accrued from increased attention to personal hygiene, 
 to diet and raiment, to the laws of disinfection, isolation, and 
 quarantine, should serve as convincing proof that the efforts 
 of the hygienist have not been in vain ; that they have not 
 only been of enormous benefit to mankind, but that with the 
 increased store of knowledge that is constantly accumulating, 
 they are still further capable of such benefits. Already count- 
 less lives have been saved ; we are told that the longevity of 
 the human race has been increased, and in eveiy way the con- 
 ditions under which man lives are better than they were a {ey^i 
 years back. 
 
 In citing, as illustrations, the advances that have been made 
 along the Hnes of hygiene and the good that has been de- 
 rived from them, it is not our desire to leave the impression 
 that the millennium has arrived ; that our stock of knowledge 
 on the subject is complete or satisfactory in all details ; or 
 indeed even that the knowledge we possess is utilized to the 
 extent that its importance demands. When we realize that 
 the majority of all deaths is still from preventible causes, most 
 of which are already quite familiar to us, it is manifest that 
 this must be in a large measure due to an indifference on our 
 part to put into practice even that knov/ledge which we 
 already possess for their prevention. The great majority of 
 deaths result from infection, from insufficient attention to diet, 
 and from want of care with regard to the temperature of the 
 body — that is to say, they are the direct outcome of our sur- 
 rounding circumstances. We consider it quite within the 
 
24 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 bounds of moderation and discretion to declare that, by the 
 indefatigable practice of the sanitary precepts now known to 
 be sound with regard to the prophylaxis and management of 
 the commoner infectious diseases, to the hygiene of infancy, 
 to diet and clothing, the death-rate from preventible causes 
 could be conspicuously reduced, and this, too, without the 
 addition of a single new fact to the knowledge that we already 
 possess. 
 
SECTION I. 
 THE CAUSATION OF DISEASE. 
 
 As has been stated, the object of hygiene is to prevent dis- 
 ease. It is therefore necessary to an understanding of the 
 means employed in securing this end that we possess a clear 
 comprehension of the factors concerned in the causation and 
 dissemination of disease. 
 
 The causative factors in disease are manifold ; they differ in 
 nature the one from the other, and are of varying degrees of 
 importance in their relation to morbid conditions. 
 
 In considering this phase of our studies it is well to bear 
 in mind from the beginning that beyond traumatisms and 
 direct poisons there is probably no single, absolute cause of 
 disease, but that the abnormal state we call disease represents 
 the termination of a chain of circumstances the various links 
 of which, while having more or less of a direct bearing upon 
 the others, are of different degrees of importance to the proc- 
 ess. Thus, by way of illustration, we say that tuberculosis is 
 caused by a specific micro-organism, and no one doubts this ; 
 but at the same time there is no one who believes for an in- 
 stant that, if to a number of individuals in sound health this 
 micro-organism gains access, tuberculosis will with certainty 
 result in all cases. There are other factors that come into 
 play and must be taken into consideration. On the one hand, 
 there are circumstances that modify the disease-producing 
 powers of the micro-organism, so that at one time it may be 
 comparatively feeble as regards this property, while at another 
 it is infective to the fullest extent. On the other hand, there 
 are modifying influences constantly at work upon the indi- 
 vidual, some of them placing him in a condition to survive 
 exposure to the most virulent forms of infection, while others 
 
 25 
 
26 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 SO modify the normal vital resistance with which nature has 
 provided him that he readily falls a prey to what would other- 
 wise be a comparatively insignificant foe. In other words, 
 certain influences to which man is exposed during the course 
 of his existence predispose him to disease in general, while 
 others are concerned in directly exciting certain definite groups 
 of symptoms and pathological manifestations, which are usu- 
 ally classed as specific diseases. In considering the causation 
 of definite or specific diseases it is impossible to ignore those 
 surrounding conditions that predispose to them. Reverting 
 to our illustration, the exciting or direct cause of tuberculosis, 
 with all its varied expressions, is Bacillus tJiberciilosis, while 
 the predisposing or indirect causes may be numerous — as 
 age, race, occupation, unsanitary surroundings, and heredity. 
 
 In their relation to specific disease-processes in general, the 
 causative factors are therefore usually classed as Exciting or 
 Direct and Predisposing or Indirect. 
 
 Predisposing Causes of Disease. — By this term is 
 meant those conditions with which man is surrounded that 
 have a tendency to so reduce his normal vital powers that he 
 is no longer capable of resisting the inroads of the direct, 
 exciting cau.ses of disease. The term " vital " or " animal 
 resistance " was at one time vaguely employed in explanation 
 of the efforts of the tissues to evade infection. In the light 
 shed by modern investigation upon the means of defence 
 possessed by the animal organism for the resistance of dis- 
 ea.se, vital resistance signifies a group of animal functions, 
 some of which are capable of ready demonstration, that is 
 pos.sessed by every living being in health, and through the 
 exercise of which the body is enabled to withstand, within 
 limits, the influence of detrimental agencies. 
 
 We now know that the circulating fluids, certain wandering 
 cells, and certain fixed cells of the animal economy are 
 directly antagonistic to many of those particulate causes of 
 disea.se known as micro-organisms ; that through the exercise 
 of these vital functions invading bacteria arc often destroyed 
 before sufficient time has elapsed for them to multiply and 
 evolve their products which are instrumental in disturbance 
 
THE CAUSATION OF DISEASE. 27 
 
 of function and destruction of tissues. We have reason for 
 believing, moreover, that within these same fluids and cells 
 lies also the power of neutralizing to a certain extent the 
 poisonous products of bacteria which themselves may not be 
 destroyed by the body. 
 
 The highest expression of this vital phenomenon is natu- 
 rally found in the healthy being. Agencies that tend to re- 
 duce the general health, such as exposure, fatigue, malnu- 
 trition, debauch, etc., tend likewise to diminish the vital 
 resistance, and in this manner render the individual more 
 susceptible to disease. 
 
 Age. — As a factor in predisposing to disease, the influence 
 of age cannot be ignored. To certain maladies the young 
 are more prone than the old, while to others the reverse is 
 the case. The greatest number of deaths, and hence the 
 greatest amount of sickness, occurs among the very young 
 and the very old — /. e., before the age of five and after the 
 age of sixty-five to seventy years, indicating that at these 
 periods the vital processes are at the one time but imperfectly 
 developed, while at the other they are declining in efficiency. 
 There are certain diseases common to all ages, though their 
 pathological manifestations may vary according to the age of 
 the subject affected. For example, tuberculosis is seen in the 
 infant, the adult, and the aged ; but in childhood its expres- 
 sions are most frequent in the lymphatic, the osseous, and the 
 serous tissues, while in maturity and old age the lungs are 
 usually involved when tuberculosis is anywhere present in the 
 body (Louis's law). 
 
 In general, it may be said that during infancy and child- 
 hood the diseases most frequently encountered are those con- 
 nected with the development of anatomical structures and the 
 establishment of physiological functions. To this may be 
 added those dependent upon congenital defects and upon 
 special hereditary tendencies, those consequent upon the 
 neglect of careless and inexperienced mothers, those result- 
 ing from undue exertion, as of occupation, during and after 
 pregnancy, those that occur in consequence of improper food 
 and clothing, and lack of cleanliness and pure air. Certain 
 
28 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 of the acute exanthemata, as measles, scarlatina, rotheln, 
 varicella, etc., are much more frequent in childhood and 
 early youth than later ; while others, as erysipelas, variola, 
 and typhus fever, may appear at any period of life. Typhoid 
 fever is most frequent in youth and early adult life. Its 
 greatest frequency is seen between the ages of fifteen and 
 twenty-five years. After forty-five years it is comparatively 
 rare. 
 
 The frequency of the acute exanthemata in childhood is 
 probably accountable for their comparative infrequency in 
 adult life, for we have reason to believe that a single non- 
 fatal attack of either or all of these maladies in childhood 
 affords a more or less permanent protection — immunity — to 
 that child from subsequent attacks of the same disease at a 
 later period of its life. 
 
 Adult life is not conspicuously more prone to one than to 
 another group of diseases. At this period man's physio- 
 logical processes are developed and in active operation, and 
 his freedom from or affliction with disease will depend very 
 largely upon the conditions under which he lives. If circum- 
 -Stances permit him to lead a rational life, giving due attention 
 to exercise, diet, clothing, cleanliness, and hygienic surround- 
 ings, there is no reason why he should not be comparatively 
 safe from disease. If, on the other hand, his life is passed 
 under conditions of extreme poverty, overcrowding, intem- 
 perance, exposure to excesses of heat, cold, or moisture, foul 
 air, bad food, impure water, uncleanliness, and exposure to 
 contagion, there are equally good reasons for expecting him 
 to fall a ready prey to disease, for these are the underlying- 
 causes of the vast majorit)' of sickness and death among all 
 ages in great cities. 
 
 The diseases incidental to old age, a period difficult to 
 define accurately because of the variation in the time of its 
 onset in different individuals, are those that depend upon the 
 gradual loss of power on the part of the organs to perform 
 their normal physiological functions, with the consequent dis- 
 turbance of nutrition and the multiform abnormal manifesta- 
 tions that this defect entails. In short, the diseases of age 
 
THE CAUSATION OF DISEASE. 29 
 
 are mainly degenerative in their nature, and simply indicate 
 irregularities that are incidental to the progressive wearing 
 out of the machineiy of life. Among the commoner may be 
 mentioned those affecting the heart and arteries, those of the 
 renal and hepatic systems, catarrhal conditions of the mucous 
 membranes, diseases consequent upon intemperance, rheu- 
 matic and gouty affections, cancers, and tumors. 
 
 Sex. — With regard to certain diseases that depend upon 
 the existence of particular anatomical structures, it is obvious 
 that sex is an important predisposing factor, particularly in 
 connection with those maladies that affect the organs by 
 which the sexes are differentiated. 
 
 The influence of sex does not, however, cease here. With 
 regard to other diseases, and indeed to disease in general, it 
 has a manifestly important bearing. For some reason or 
 reasons, for there are probably many to explain it, the gen- 
 eral death-rate among females is uniformly lower than that 
 among males, and statisticians, as a rule, assign to women a 
 greater expectation of life than to men. On reflection we 
 might be prepared for this, for by the nature of things males 
 are brought, during the course of their daily life, into closer 
 contact with a greater variety of surrounding conditions that 
 may influence their health than are women. Man's exposure 
 to accident is also much greater. 
 
 With regard to certain diseases, the influence of sex is very 
 apparent, and in some cases this influence varies conspicu- 
 ously according to age. In some instances the influence of 
 sex does not appear until the advent or after the age of 
 puberty. Before this period the sexes are less markedly 
 differentiated in their relation to disease. By way of illustra- 
 tion : — This influence of age and sex upon mortality is very 
 strikingly brought out in connection with cancer, anemia, and 
 typhoid fever. For the six years ending with May 31,1 890, 
 according to the last (eleventh) United States Census, there 
 occurred in New York City among the white population 48 
 deaths from cancer in individuals under fifteen years of age ; 
 of these 24 were in males and 24 in females ; for the ages 
 between fifteen and forty years there were 782 deaths from 
 
30 
 
 JIYGIENE OF TRANSMISSIBLE DISEASES. 
 
 the same cause ; of these 222 were in males and 560 in 
 females ; while for all over forty years of age the number of 
 deaths from cancer was 3952, of which 1299 occurred in 
 males and 2653 in females. 
 
 Anemia resulted fatally in 49 individuals under fifteen 
 years of age ; of these 22 were males and 27 females ; it 
 caused the death of 64 persons between the ages of fifteen 
 and forty years ; of these 1 8 were males and 46 females ; 
 while for the ages over forty years there were 56 deaths, of 
 which 19 were males and 37 females. 
 
 The deaths from typhoid fever among those under fifteen 
 years of age were 290, of which 152 were males and 138 
 were females ; among the deaths of those between fifteen and 
 forty years of age from the same cause, there were 828 males 
 and 526 females, while the deaths of those over forty years 
 were found to be 213 males and 148 females. In the case of 
 cancer it is clear that advancing years and female sex offer 
 conditions favorable to its development. In the case of 
 anemia there seems to be no preference for the sexes before 
 puberty. After that time until the period of old age females 
 are much more liable than males. With typhoid fever we 
 find the greatest number of deaths during the period of 
 youth and early adult life, but the greater number of deaths 
 is among males ' (see Table I.). 
 
 Taulk I. — Deaths among the ivhite population of New YorJz City 
 from Anemia, Typhoid Fever, and Cancer dui'ing the six 
 years ending May ji, i8go, with distinction of age and sex. 
 
 
 Anemia. 
 
 Typhoi 
 
 d Fever. 
 
 Cancer. 
 
 Males. 
 
 Females. 
 
 Males. 
 
 152 
 828 
 213 
 
 1193 
 
 Females. 
 
 Males. 
 
 Females. 
 
 Under 15 yeans . . 
 
 From 15 to 40 years . 
 
 Over 40 years . . . 
 
 Totals .... 
 
 22 
 18 
 
 59 
 
 27 
 46 
 
 37 
 no 
 
 138 
 526 
 148 
 
 24 
 
 222 
 
 1299 
 
 24 
 
 560 
 
 2653 
 
 3237 
 
 812 
 
 1545 
 
 ' The numerical method here employed may not be acceptable in the 
 light of accurate statistical methods. The figures represent only the absolute 
 numbers and not the relation of such numbers to a fixed standard of compar- 
 ison. They are, however, quite ne;ir enough to accuracy to serve as a fair 
 illustration. 
 
THE CAUSATION OF DISEASE. 3 1 
 
 According to the same document, males afford a greater 
 number of deaths than females from typhoid fever, venereal 
 diseases, alcoholism, lead- and other forms of poisoning, 
 hydrocephalus, tetanus, and trismus nascentium, convulsions, 
 diseases of the brain and cord, angina pectoris, aneurysm, 
 laiyngitis, diseases of the liver, urinary calculus and renal dis- 
 eases, diseases of the bladder and genito-urinary tract, dis- 
 eases of the bones, of the spleen, and accidents. Females 
 succumb more frequently than males to malaria, cancer, 
 anemia, dropsy, ascites, diseases of the stomach, peritonitis, 
 and, of course, to diseases of the female reproductive organs, 
 and to those incidental to pregnancy and childbirth. In 
 some instances the reason for these differences is manifest ; in 
 others it is in obscurity. 
 
 Race. — It is a well-known fact that the predispositions of 
 the different races of mankind to particular forms of disease 
 are not uniform. Some exhibit a pecuHar susceptibility to 
 certain maladies, while others possess a comparative degree 
 of immunity from them. 
 
 In some instances this is explainable through the pro- 
 longed exposure of races to particular diseases, resulting in 
 their acquisition of a greater degree of tolerance to them 
 than is seen to be possessed by other races, or other portions 
 of the same race, that have not been similarly exposed. 
 
 It is difficult to obtain trustworthy data that are of general 
 application in deciding the influence of race upon disease, 
 because of the many determining factors that come into play. 
 Nevertheless, through vital statistical studies of groups of 
 people of different races living under various conditions, we 
 have obtained data of more or less importance that are indic- 
 ative of the relative frequency of different diseases among 
 them. Whether the results obtained by this method are 
 entirely trustworthy or not it is difficult as yet to decide ; the 
 differences, as said, may depend upon so many surrounding 
 circumstances — the social conditions, with all that these entail, 
 under which the different peoples were living at the time of 
 the observation being perhaps the most important. 
 
 With regard to the influence of race on disease in general, 
 
32 HYGIENE OE TKAXSMISSIBLE DISEASES. 
 
 there is more or less disagreement of opinion, thoui^ii in 
 several special instances there is striking evidence in favor of 
 such a relation. There is a general consensus of opinion 
 that the negro is less susceptible to yellow fever and malaria 
 than the white man, and the white man less susceptible to 
 pulmonary troubles and cholera than the black man ; that 
 the German oftener falls a prey to cancer than his Celtic 
 cousin ; and that the Jew escapes more frequently from dis- 
 eases of a tuberculous nature and from epidemic diseases 
 than does any other race of mankind. But when we attempt 
 to carry the investigation further confusing factors, varying in 
 the degree of their importance, are encountered, and the 
 results obtained cannot be considered as entirely reliable for 
 purposes of generalization. It is probable that there is no 
 disease to which mankind is liable from which any race of 
 man possesses absolute natural (/. c, congenital) immunity. 
 
 For the study of race-influence upon the frequency of and 
 mortality from special diseases among different peoples, living 
 under approximately similar conditions and equal degrees of 
 exposure to disease, the United States with their large popu- 
 lation, con.sisting of representatives of almost every nation, 
 the diversity of their geological and climatic conditions, and 
 especially, as in the great cities, the more or less intimate ad- 
 mixture of the different races, offer an unusual opportunity. 
 
 Important light is shed upon this matter through the Cen- 
 sus and Vital Statistics of our people, taken ever>' ten years. 
 In the compilation of these reports it is cu.stomary to compare 
 the death-rates, or actual deaths (fair indices of .sickness) from 
 different causes among the foreign population, with the deaths 
 among the native white and colored population, and while 
 the deductions drawn from this method are of undoubted 
 value in illu.strating the relative susceptibilities of these vari- 
 ous peoples to different di.seases, it mu.st be remembered that 
 the comparisons are made between peoples of very different 
 social conditions, and that they are not therefore as trust- 
 worthy as they would be were the inequality in this respect 
 less ; though they undoubtedly indicate the frequency of dis- 
 ea.se under the existing circumstances. 
 
THE CAUSATION OF DISEASE. 
 
 33 
 
 The census of 1 890 for the city of New York shows the 
 lowest death-rate from all causes to have been among the 
 Russians and Poles, the majority of whom in this countiy are 
 of the Semitic race, while the highest general death-rate was 
 among the Italians. The fallacy and inconstancy of the re- 
 sults obtained by this method are best illustrated by the 
 results of statistics compiled along the same lines and at the 
 same time in Boston and Philadelphia. In Boston the high- 
 est death-rate from all causes and at all ages was among the 
 Irish, and the lowest among the French ; while in Philadel- 
 phia the native whites experienced the greatest loss from 
 death and the Bohemians the least. The high (relatively 
 speaking) death-rate among the native white population of 
 Philadelphia is probably due to the relatively larger number 
 of married and marriageable native Americans in that city, 
 and consequently a larger number of young children than are 
 found in any of the other groups (Billings). 
 
 Table II. — Comparing the death-i'ates per 1000 of white and 
 negro populations for the six years eliding with May ji, i8go 
 {Eleventh United States Census) : 
 
 White. Colored. 
 
 Boston 
 
 - • • 23.71 
 
 31.92 
 
 New York 
 
 . . . 29.86 
 
 , 33-27 
 
 Brooklyn . 
 
 . . 25.90 
 
 30.54 
 
 Philadelphia 
 
 . . . 22.69 
 
 31-25 
 
 Baltimore 
 
 . . . 21.98 
 
 35-99 
 
 District of Columbia . . . 
 
 • • • 1975 
 
 37.00 
 
 A conspicuously constant racial influence upon suscepti- 
 bility to disease is observed in comparisons between the death- 
 rates among the white and negro populations. In eighteen 
 southern and four northern cities the eleventh census shows 
 that the general death-rate for all ages was in each case 
 greater among the colored than among the white natives 
 (see Table II.). It is not unlikely, however, that this is 
 due to social condition as much as, if not more than, to 
 racial peculiarity. 
 
 As has been stated, the negro is less susceptible to yellow 
 fever than the white man, though this not always the case. 
 3 
 
34 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 Instances are recorded in which the mortality of negroes from 
 this disease, during times of epidemics, was as great as among 
 the white. The comparative immunity of the negro is prob- 
 ably accjuired, as it has been observed that negroes who are 
 born and raised in countries and localities where the disease 
 is unknown are practically as susceptible as whites when ex- 
 posed to the infection. It may or may not be due to acquired 
 tolerance, or " acclimatization," as it is sometimes called, that 
 a similarly relatively low degree of susceptibility of the negro 
 to malaria is observed; of 614 cases of malaria, seen in Bal- 
 timore, and described and analyzed by Thayer and Hewetson, 
 585 occurred in whites, while only 29 were in colored per- 
 sons. On the other hand, " there is a general consensus of 
 opinion that the negro is especially liable to Asiatic cholera " 
 (Hirsch). According to Walther (quoted from Hirsch), the 
 mortality from cholera in Guadeloupe during the epidemic of 
 1865 was divided among the following peoples in the follow- 
 ing percentages : Chinese, 2.7 per cent. ; Hindoos, 3.26 per 
 cent.; whites, 4.31 per cent.; mulattos, 6.32 per cent., and 
 negroes, 9.44 per cent. During the epidemic of 1866 in this 
 countiy the mortality from cholera among the white troops 
 (U. S. army) was ']'] , and that among the colored 1 35 per lOOO 
 (Hirsch). By the vital statistics of New York city, census 
 of 1890, consumption, pneumonia, heart disease, puerperal 
 diseases, and diseases of the urinaiy apparatus were found to 
 be more fatal among the negro than the native white popula- 
 tion ; while scarlet fever, diphtheria, croup, diarrheal diseases, 
 measles, whooping cough, diseases of the liver, and diseases 
 of the nervous system were more fatal to the native white 
 than the colored race. 
 
 The table given on page 35 (Table III.) presents these 
 relations numerically. 
 
 In numerous instances the Chinese have shown a con.spicu- 
 ous immunity from cholera. 
 
 One of the most striking examples of specific racial im- 
 munity from disease is, as stated, that observed among the 
 Jews. While they are attacked by the general run of dis- 
 eases as often as, and sometimes more often than, Christians, 
 
THE CAUSATION OF DISEASE. 
 
 35 
 
 yet they are very much less frequently the subjects of tuber- 
 cular and acute epidemic diseases than any other race of 
 mankind. 
 
 Table III. — Proportion of deaths from different diseases per 
 100,000 of mean popiclation in the city of New York for the 
 six years ending May ji, i8go, with distinction of color and 
 nativity : 
 
 Scarlet fever 
 
 Diphtheria 
 
 Croup 
 
 Diarrheal diseases 
 
 Consumption 
 
 Pneumonia 
 
 Measles 
 
 Whooping-cough 
 
 Cancer and tumor 
 
 Heart disease and dropsy . . 
 Childbirth and puerperal diseases 
 
 Diseases of the liver 
 
 Diseases of the nervous system . 
 Diseases of the urinary organs . 
 
 White 
 (native). 
 
 79-58 
 
 179.46 
 
 78.76 
 
 383-24 
 
 238.48 
 
 280.15 
 
 58.34 
 
 54-24 
 
 54.92 
 
 130.00 
 
 16.87 
 
 24.05 
 
 308. 64 
 
 147.76 
 
 White 
 (foreign). 
 
 9.89 
 17-58 
 
 8.59 
 90.25 
 
 483-83 
 
 265.27 
 
 6.56 
 
 1.69 
 
 102.61 
 
 194-95 
 38.01 
 
 53-79 
 197.06 
 253-86 
 
 Colored. 
 
 II. II 
 
 31-94 
 13-19 
 
 243.72 
 
 774.21 
 
 324-27 
 
 15.28 
 
 39-58 
 
 45-13 
 
 188.17 
 
 23.61 
 
 12.50 
 
 240.25 
 
 242.33 
 
 Richardson states that " the mortality from cholera among 
 them is so small that the very fact of its occurrence has been 
 disputed From epidemics the Jews have often es- 
 caped, as if they possessed a charmed life," In " The Vital 
 Statistics of the Jews of the United States," compiled by Dr. 
 Bilhngs in 1890, it is seen that, as compared with the popula- 
 tion of the entire United States, and with that of the State of 
 Massachusetts, the Jews " suffered a relatively greater loss 
 than their neighbors by deaths from diphtheria, diarrheal dis- 
 eases, diseases of the nervous system (and especially from 
 diseases of the spinal cord), from diseases of the circulator}^ 
 system, urinary system, bones and joints, and of the skin ; 
 while their mortality has been relatively less from tubercu- 
 lar diseases, including scrofula, tabes, and hydrocephalus, than 
 the other people with whom they are compared." 
 
 The following table (Table IV.), abridged from this report, 
 shows the relative difference, as regards consumption, scrof- 
 ula, and hydrocephalus, numerically : 
 
36 JIYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 Taule 1\'. — Giving the male Jew is Ji deatJi-rate from Consump- 
 tion, Serofula, and Hydrocephalus per 1000 total deaths from 
 known causes, as compared with the rates similarly calculated 
 for the entire population of the United States in 1880 and for 
 that of Massachusetts in 1888 : 
 
 Diseases. 
 
 Jews. 
 
 All United States, 
 1880. 
 
 All Massachusetts, 
 1888. 
 
 Consumption . . . 
 
 • 36-57 
 
 108.79 
 
 129.22 
 
 Scrofula and tabes . 
 
 . 1.04 
 
 6.74 
 
 30.60 
 
 Hytlrocephalus . . 
 
 • i-^l 
 
 6-43 
 
 11.74 
 
 This conspicuous immunity of the Jewish race from disease 
 has attracted the attention of statisticians in several countries 
 of the world, with the result of demonstrating this peculiarity 
 to be pretty uniform. Quoting from the researches of de Neuf- 
 ville, at Frankfort : " The average duration of the life of the 
 Jew is forty-eight years and nine months, and of the Christian 
 thirty-six years and eleven months ; . . . half the Jews born 
 reach the age of fifty-three years and one month, whilst half 
 the Christians born attain the age of thirty-six years only. 
 A quarter of the Jewish population is found living beyond 
 seventy-one years, but a quarter of the Christian population 
 is found living beyond fifty-nine years and ten months only." ^ 
 As an explanation of this vital advantage on the side of the 
 Jews, Richardson .states " the causes are simply summed up 
 in the term ' soberness of life.' The Jew drinks less than his 
 ' even Christian ' ; he takes, as a rule, better food ; he marries 
 earlier ; he rears the children he has brought into the world 
 with greater personal care ; he tends the aged more thought- 
 fully ; he takes better care of his poor, and he takes better 
 care of himself" To this might perhaps be added, he has 
 inherited traces of tlie respect shown by his ancestors for the 
 laws of Moses for the hygienic guidance of the children of 
 Israel. 
 
 It woukl be vain to contend tliat the observations made 
 under this lieading and the statistics presented justify dog- 
 
 ' fie Xeufville : Lebensdauer und Todesursachen zwci und y.vvanzig ver- 
 schiedener Stande und (Jewerbe, nebst vergleichender Statistik der christlichen 
 und israelitisclien Hevolkerung Frankforts, 1855. Lauerlander's Verlag, I'raii/;- 
 forl, a. m. (Tables XIX., XX., XXI., pp. 115-116). 
 
THE CAUSATION OF DISEASE. 37 
 
 matic generalizations. They are simply important indica- 
 tions that are liable to modifications according to surrounding 
 circumstances. 
 
 Occupation. — It is generally recognized that certain kinds 
 of occupation predispose to disease, and that there is a par- 
 ticular tendency on the part of those that follow them to 
 special groups of maladies. In fact, it may be said that there 
 exists more or less of a parallelism between the increase in 
 industries and the increase of disease and death. With 
 regard to the majority of occupations, disease is due less to 
 the character of the work done than to the conditions under 
 which it is performed, for moderate work of almost any kind, 
 when done under favorable conditions, must be considered as 
 in every way advantageous to the physical, moral, and mental 
 well-being of the worker. 
 
 The conditions of occupation that most frequently predis- 
 pose to ill-health are the generally poor hygienic surround- 
 ings, such as overcrowding in poorly ventilated, improperly 
 heated, damp, and uncleanly offices and workshops ; the 
 inhalation of dust-laden atmosphere ; exposure to extremes 
 of weather, as heat, cold, and excessive moisture ; and the 
 consumption of food that is neither in quality, quantity, nor 
 mode of preparation adequate to repair the tissue-loss conse- 
 quent upon muscular and mental exertion. To this may 
 be added the evil effects of working in cramped or con- 
 strained attitudes, particularly such as interfere with the 
 normal action of the heart and lungs ; of unusually pro- 
 longed mental exertion ; and of those occupations affording 
 constant temptation to the too frequent use of alcoholic 
 stimulants (see Table V., page 38). 
 
 The result of these influences manifests itself in the form 
 of either local or general reduction of vitality. In some cases 
 there occurs a general undermining of the health of the indi- 
 vidual ; in others the effect is more or less local, and is con- 
 fined to those tissues directly under the influence of the hurt- 
 ful conditions, converting them into points of least resistance 
 that serve as portals of infection. 
 
 A large proportion of industrial occupations predispose to 
 
38 HYCIEXE OF TRAXSMISSIBLE DISEASES. 
 
 diseases of the lungs, through the inhalation of finely divided 
 particles of matter in the form of dust. This tends in general 
 to pulmonary tuberculosis and to other pulmonary troubles, 
 principally chronic bronchitis, emphysema, bronchiectasis, and 
 interstitial pneumonia. 
 
 Table V. — Co)iiparativc mortality of liquoi' dealers with that of 
 men generally ( Ogle) : 
 
 Men 25 to 65 Years of Age. 
 
 Diseases. , ' ■ 
 
 Liquor Trade. AH Males. 
 
 Alcoholism 55 10 
 
 Liver diseases 240 39 
 
 Gout 13 3 
 
 Diseases of the nervous system . . . 200 1 19 
 
 Suicide 26 14 
 
 Diseases of the urinary system .... 83 41 
 
 Diseases of the circulatory system . . 140 120 
 
 Other causes 764 654 
 
 - All causes 1521 1000 
 
 According to Ogle,^ the effect of dust-inhalation appears to 
 differ with the physical character of the dust inhaled. That 
 from ordinary soft wood (as inhaled by carpenters) seems to 
 be relatively harmless, while that from hard woods (as inhaled 
 by cabinet-makers) is much more irritating. The dusts that 
 seem to be the most dangerous to the tissues of the respira- 
 tory apparatus are those encountered in the various textile 
 works, mineral du.sts, and the dusts of metals. Cutlers, file- 
 workers, stone-cutters, and cotton-wool workers show a 
 marked tendency to pulmonary tuberculosis. A singular 
 exception is seen in the coal-miners ; while constantly inhaling 
 a dust-laden atmosphere, usually to such a degree as to result 
 in the production of a distinct pathological condition of the 
 lungs (anthracosLs), the mortality from pulmonaiy consump- 
 tion among miners is, according to Ogle, comparatively low. 
 
 Aside from its irritating influence dust may and often does 
 serve as a direct carrier of infection. This is conspicuously 
 the case when numbers of individuals are constantly together 
 in unkept rooms. With regard to tuberculosis, the inhalation 
 of dust contaminated with the dried sputum from consump- 
 
 ' Trans. Seventh Congress of 1 Ivi^icnc and Dcniop-apliv, London, 1891. 
 
THE CAUSATION OF DISEASE. 39 
 
 tives is probably one of the most common channels for the 
 dissemination of the disease ; the greater frequency of the 
 pulmonary manifestation of this malady may be cited in sup- 
 port of this opinion. Disease-producing agents other than 
 that concerned in the causation of tuberculosis, notably the 
 pyogenic bacteria, have been found in the dust of localities 
 occupied by individuals suffering from suppurative troubles. 
 
 In the paper presented by Dr. Ogle, quoted above, attention 
 was called to the fact that " there are some occupations of so 
 deadly a character that life-insurance companies will have 
 nothing to say to them, refusing to insure the life of a man 
 engaged in them on any terms whatsoever ; while, on the 
 other hand, there are professions, or at any rate there is one 
 profession, in which the chances of longevity are so high that 
 an insurance company which is lucky enough to number a 
 considerable proportion of those engaged among its clients, 
 advertises the fact to show the general public upon what a 
 safe basis its business is founded." Dr. Ogle presents, in 
 illustration of the influence of employment on mortality, the 
 following table (see Table VI.), compiled from a very large 
 number of observations made upon men between the ages of 
 twenty-five and sixty-five years. It must be said, with regard 
 to such results, that they cannot be accepted as universally 
 correct indications of the influence of occupation on mortality 
 and disease, for many individuals in all callings are constitu- 
 tionally tainted, or probably predisposed by inheritance to 
 particular diseases, before they select their life calling ; and 
 also that the death or disease among individuals following a 
 given trade at the time of the census may be in no way 
 dependent upon the influence of that calling, but rather upon 
 some one followed by them at an antecedent period. 
 
 Among the various industrial pursuits there are some that 
 expose the workmen to influences, in addition to those gen- 
 erally predisposing, that are directly concerned in the causa- 
 tion of disease-conditions. Such occupations involve the 
 manipulation of various chemical poisons, such for instance 
 as phosphorus by match-workers ; arsenic, by makers of cer- 
 tain pigments ; poisonous anilins, by those engaged in their 
 
40 
 
 JIYGIENE OF TRAiXSMISSIBLE DISEASES. 
 
 Table \"I. — Coinparaiivc mortality of moi, tivcuty-Jivc to sixty- 
 fivc xcars of age, in different occupations, 1881 to 188 j ( Ogie) : 
 
 Comparative 
 mortulily. 
 
 Occupation. 
 Clergymen, priests, and min- 
 isters 100 
 
 Lawyers 152 
 
 Medical men 202 
 
 tiardeners 108 
 
 Farmers II4 
 
 Agricultural laborers . . . 126 
 Fishermen 143 
 
 Commercial clerks . . . .179 
 Commercial travellers . . . 171 
 Innkeepers, liquor dealers . 274 
 
 Inn, hotel service 396 
 
 Brewers 245 
 
 Butchers 211 
 
 Bakers 172 
 
 Corn millers 172 
 
 Grocers 139 
 
 Drapers 159 
 
 Shopkeepers generally . . . 158 
 
 Tailors 189 
 
 .Shoemakers 166 
 
 Hatters 192 
 
 Printers 193 
 
 I>()()kbinders 2IO 
 
 Occupation. \ ... 
 
 ■^ mortality. 
 
 Builders, masons, bricklayers 174 
 Carpenters, joiners .... 147 
 Cabinet-makers, upholsterers 173 
 Plumbers, painters, glaziers 216 
 
 Blacksmiths 175 
 
 Engine, machine, and boiler 
 
 makers 155 
 
 Silk manufacture 152 
 
 Wool, worsted manufacture . 186 
 Cotton manufacture . . . .196 
 
 Cutlers, scissor makers . . . 229 
 
 Gunsmiths 186 
 
 File makers 300 
 
 Paper makers 129 
 
 Glass workers 214 
 
 Earthenware makers . . . .314 
 
 Coal miners 160 
 
 Cornish miners 331 
 
 Stone, slate quarries .... 202 
 
 Cab, omnibus service . . . 267 
 Railway, road laborers . . . 185 
 CosteiTnongers, hawkers, and 
 
 street sellers 338 
 
 mantifacturc ; lead, by file-makers, painters, and plumbers; 
 mercury, by hatters- and gilders. Brass-founders and those 
 who work in copper and zinc are subject to a peculiar form 
 of ague — "brass-founders' ague." The continuous inhalation 
 of irritating and irrespirable gases likewise results in diseased 
 conditions of the air-passages — the direct results of such con- 
 ditions — and likewise in constitutional poisoning. Among 
 these agents may be mentioned the vapors of iodine and 
 bromine, besides chlorine, ammonia, arsenuretted and phos- 
 phoretted hydrogen, nitrous and sulphurous acids, and carbon 
 monoxide and dioxide. 
 
THE CAUSATION OF DISEASE. 
 
 41 
 
 Density of Population — Crowding. — ^It is a matter of 
 common observation that sickness and death are most fre- 
 quent in those communities where large numbers of people 
 are crowded together in comparatively close quarters under 
 the conditions of poverty that such an existence entails. 
 
 The accentuation of death-rate resulting from the condi- 
 tions concomitant with excessive density of population, while 
 manifest for all ages, is conspicuously evident among the 
 very young of such a community. The following table serves 
 to illustrate this strikingly (Table VII.). 
 
 Table VII. — Showiug relation between death-rafe per 1000 and 
 density of population in seven groups of districts in England 
 and Wales {exclusive of London ^) .• 
 
 Persons to i sq. 1 
 mile . , . . ) 
 
 166 
 
 186 
 
 379 
 
 1718 
 
 4499 
 
 12,357 
 
 65,823 
 
 Mean death-rate | 
 at all ages . . ) 
 
 16.75 
 
 19.16 
 
 21.88 
 
 24.90 
 
 28.08 
 
 32-49 
 
 38.62 
 
 Mean death-rate (^ 
 under 5 years / 
 
 37.80 
 
 47-53 
 
 63.06 
 
 82.10 
 
 95-04 
 
 III. 90 
 
 139-52 
 
 Mean ' birth-rate | 
 
 
 
 
 
 
 
 
 per 1000 of \ 
 
 30.2 
 
 32.2 
 
 35-8 
 
 38.7 
 
 40.2 
 
 37-3 
 
 37-6 
 
 living . . . . j 
 
 
 
 
 
 
 
 
 In a paper presented by Dr. J. B. Russell to the Philosoph- 
 ical Society of Glasgow in 1888^ there appear the results of 
 studies made with the view of determining in how far an 
 excessive density in population affected the death-rate of that 
 city and to what extent such crowding was answerable for 
 the prevalence of diseases of a special character. The author 
 demonstrates that the death-rate in Glasgow is greatest in 
 those districts in which the greatest number of individuals are 
 domiciled in the smallest cubic space, and that there is a 
 gradual decrease in the death-rate as the ratio between living- 
 space and number of inhabitants becomes greater (Table VIIL). 
 
 ' Consult 35th Report of the Registrar General of England (1875) ; Sup- 
 plement, pp. clviii, clix. 
 
 ^ On the "Ticketed Houses" of Glasgow, with an Interrogation of the 
 Facts for Guidance toward the Amelioration of the Lives of Occupants. By J. 
 B. Russell, B. A., M. D., LL.D., Proc. Phil. Soc, 1888-89, vol. xx., pp. i 
 to 24 inclu. 
 
42 
 
 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 Table VIII. — The folloiving table, eompilcd by Dr. Russell, 
 sho7vs tJie distribution of population and deaths in houses of 
 various sizes : 
 
 Size of House. 
 
 Pupuhition. Deaths. 
 
 One room 134,728 
 
 Two rooms 243,691 
 
 Three 
 
 Four " .... 
 
 Five rooms and upward 
 
 Institutions 
 
 Un traced 
 
 Whole city . . . 
 
 86,956 
 
 32,742 
 
 38,647 
 
 6,531 
 
 543,295 
 
 3,636 
 6,325 
 
 1,747 
 581 
 434 
 427 
 289 
 
 13,439 
 
 Percentage of 
 
 Population. 
 
 Deaths. 
 
 24.7 
 
 27.0 
 
 44-7 
 
 47.0 
 
 16.0 
 
 13.0 
 
 6.1 
 
 4-3 
 
 7-1 
 
 3-3 
 
 1.4 
 
 3-2 
 
 
 2.2 
 
 1 00.0 
 
 1 00.0 
 
 As to the character of diseases most prevalent among the 
 occupants of these several classes of domiciles, the same 
 author found that zymotic, nervous, and nutritive diseases of 
 children, accidents and syphilis in children, pulmonary and 
 miscellaneous diseases occurred in the relative degrees of 
 frequency indicated by the following table and chart (Table 
 IX., Chart i). 
 
 Table IX. — Showing death-rates per 100,000 from cef'tain classes 
 of diseases in various size houses {Russell^ : 
 
 One and Three and 
 
 two room four room 
 
 houses. houses. 
 
 Zymotic di.seases 478 
 
 Acute diseases of the lungs (including "| p 
 
 consumption) ) " -^ 
 
 Nervous diseases and diseases of nutri- ^ o 
 
 tion in children / ^ 
 
 Accidents and syphilis in children . . . i 32 
 
 Miscellaneous unclassified diseases . . . j 799 
 
 All causes 2774 
 
 It would be a mistake, however, to consider that the 
 parallelism between the various densities of population and 
 increase of death-rate observed in Glasgow forms a basis for 
 an infallible generalization that would be applicable to the 
 entire population of all countries ; for in a census of 28 large 
 towns in England and in Wales (ending Januaiy i, 1897) it 
 was impossible to detect such constancy between density of 
 
THE CAUSATION OF DISEASE. 
 
 43 
 
 population and death-rate, though the communities studied 
 were embraced between the extremes represented by Hud- 
 dersfield, with a population of 90,034, a density of 8.6 persons 
 per acre, a birth-rate of 27.7, and a death-rate of from 19.6 to 
 23.0 per 1000, and Liverpool, with a population of 592,991, a 
 density of 113.8 persons per acre, a birth-rate of 31.2, and a 
 death-rate of from 23.7 to 25.2 per 1000. 
 
 Chart i. — Showing incidence of certain classes of diseases among 
 occupants of various size houses {^Russell ). 
 
 a b c 
 
 a. One and two room nouses ; b, three and four room houses ; c, five rooms 
 and upward; (i) zymotic diseases; (2) nervous and other diseases special to 
 children; (3) accidents and syphihs in children; (4) diseases of the lungs; {5) 
 miscellaneous diseases. 
 
 Similarly in the United States ^ we find the density of 
 population, as expressed by persons per acre, to bear no con- 
 stant relation to the death-rates in 50 large cities in this 
 country, from which the statistics were compiled. The data 
 
 1 See Eleventh Census of the United States, volume on Social Statistics of 
 Cities. Diagram 3, pp. 8 to 12. 
 
44 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 referred to were embraced between the extremes represented 
 by New York cit}', with 58 persons per acre and a death-rate 
 of 28.63 per 1000 of population, and Fall River, Mass., with 4 
 persons per acre and a death-rate of 24.84 per looo of popu- 
 lation. Though a diminution in the number of persons per 
 acre from New York city through the list to Fall River, 
 Mass., was constant, still the death-rates observed in the cities 
 of the table that fall between these extremes were most irreg- 
 ular, 6 being practically equivalent to that of New York city, 
 and 34 being less than that of Fall River, Mass. 
 
 It must be said, however, that the data obtained from the 
 "]% cities, including 2'^ in England and 50 in this country, do 
 not of necessity vitiate the results of Dr. Russell's studies, for 
 " the statement of the average density of the population of a 
 city by no means indicates the amount of overcrowding which 
 may exist in certain parts of it " (Billings). 
 
 It does not seem improbable that had investigations been 
 conducted in any or all of these 78 cities along identically the 
 same lines as those employed by Dr. Russell, results corre- 
 sponding with those obtained by him could have been secured 
 for people living in sections of these cities under conditions 
 of overcrowding such as were observed and studied in 
 Glasgow. 
 
 The most important factors in favor of an increasing death- 
 rate, under conditions of high aggregation of people, are the 
 generally unhygienic conditions under which the population 
 exists, including filth, bad air, poor and insufficient food, in- 
 adequate clothing, deficient shelter, increased opportunities for 
 direct infection, and the manifold, though potent, influences 
 that are concomitant with poverty. The dissemination of 
 infection is in inverse ratio to the distance between individuals 
 congregated together in a habitation ; the greater the distance 
 the less, the less the distance the greater the liability for in- 
 fection to spread. 
 
 " The more crowded a community, the greater, speaking 
 generally, is the amount of abject want, of filth, of crime, of 
 drunkenness, and of other excesses, the more keen the com- 
 petition and the more feverish and exhausting the conditions 
 
THE CAUSATION OF DISEASE. 45 
 
 of life. Moreover, and perhaps more than all, it is in these 
 crowded communities that almost all the most dangerous 
 and unhealthy industries are carried on. It is not so much 
 the aggregation itself, as it is these other factors which are 
 associated with aggregation, that produce the high mortality 
 of our great towns, or other thickly populated areas " (Ogle). 
 
 Heredity — In predisposing to disease heredity manifests 
 its influence more through the transmission of a peculiar 
 habit of body than by the transmission of disease itself In 
 the modern sense, inherited predisposition to disease implies 
 a congenital condition that is pecuHar to the idioplasm of the 
 individuals of certain families, a condition that inclines them 
 to this or that particular form of malady. For instance, in 
 some families we observe a peculiar tendency to nervous dis- 
 eases, as to epilepsy, or insanity ; in others to cancers and 
 tumors ; in others to scrofula, tabes, and other tubercular 
 manifestations. The rheumatic and gouty diatheses and 
 syphilis belong also to this category. Again, families are 
 encountered that are endowed with a marked predisposition 
 to acute diseases, while in others there is an equally marked 
 resistance to them. In short, the inheritance of a tendency 
 to or immunity from disease is due fundamentally to the same 
 processes through which peculiarities of a physical, moral, or 
 mental nature are transmitted. 
 
 The question concerning the direct transmission of disease 
 from parents to offspring is oiic over which there has been a 
 great deal of controversy. With regard to certain diseases, such 
 as syphilis and some of the acute infections, there can be no 
 doubt that such a transmission occurs ; but in connection 
 with tuberculosis there is .still more or less disagreement of 
 opinion. The weight of evidence contra-indicates the prob- 
 ability of tuberculosis being often directly inherited, and while 
 it is impossible to deny the intra-uterine existence of the dis- 
 ease, yet hereditary tuberculosis must be looked upon as a 
 rarity. The part played by heredity in the dissemination of 
 this disease is more often observed in the transmission of a 
 generally enfeebled constitution, with a special predisposition 
 to this particular form of infection. It is manifest that through 
 
46 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 the intimacy existintj between tubercular patients, particularly 
 mothers, and their offspring that are congenitally endowed 
 with this predisposition, there are abundant opportunities for 
 accidental infection. Fagge calls attention to the frequent 
 impossibility of distinguishing between hereditary and acci- 
 dentally-acquired tuberculosis. On the other hand, Baum- 
 garten favors the opinion that tuberculosis is frequently in- 
 herited, and that the virus lies dormant (is held in check) 
 until after the period of active, infantile tissue-development, 
 when it exhibits its pathogenic properties. 
 
 It is appropriate at this place to refer to the relative insus- 
 ceptibility to disease that is occasionally observed, and to 
 repeat that this peculiarity, like predisposition to disease, is a 
 property that is inherent to the germ-plasm of the individuals 
 and their progenitors thus endowed. It is not probable that 
 the comparative immunity from, or the increased resistance 
 to, a disease that is conferred upon an individual by a single 
 non-fatal attack of that disease is transmitted to his offspring, 
 any more than are the numerous other quickly acquired traits 
 or characteristics. At least we have no evidence in favor of 
 such a view. Important light has been shed upon this phase 
 of our subject by the brilliant researches of Ehrlich and cer- 
 tain of his followers in these interesting investigations. Ehrlich 
 has shown that acquired immunity from poisons that are in 
 many respects analogous to those concerned in the morbid 
 phenomena of infectious diseases is not transmissible from 
 parents to offspring, in the way that physical and mental pe- 
 culiarities are handed down ; in fact, they are not inherited at 
 all, but that for a temporary period during nursing the immune 
 mother conveys to the suckling, through the milk, a substance 
 that serves to protect the offspring from the disease from 
 which the mother is immune. This protection is not perma- 
 nent, but ceases with, or a veiy short time after, the cessation 
 of nursing. Moreover, this protection is maternal, the father 
 taking no part in it — a state of affairs contrary to what we 
 know to be the case with regard to the inheritance of physical, 
 mental, and moral characteri.stics. 
 
 It is more than probable that the observation of Krhlich, 
 
THE CAUSATION OF DISEASE. 
 
 47 
 
 made upon animals (mice), may have an important bearing 
 upon the phenomenon in human beings. 
 
 Season. — The fact that certain groups of diseases are most 
 prevalent at definite seasons of the year indicates a predis- 
 posing relation between the characteristics of those seasons 
 and such diseases. 
 
 Chart 2. — Showing the monthly fluctuations in the death-rates from 
 diseases of the respiratory system in Nezv York City and in Balti- 
 rnore. 
 
 
 Months 
 
 
 NEW YORK CITY 
 
 BALTIMORE 
 
 30 20 10 
 
 10 20 30 
 
 
 
 
 
 
 
 1 
 
 Jviiie 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 July 
 
 
 
 
 
 
 
 
 
 
 
 
 ' 
 
 
 m^i ^^vigvist 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 fl 
 
 SepteiTtilDer 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Octolaer 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 USTovem.'ber 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 DecemlDer 
 
 
 ■ 
 
 
 
 
 
 
 
 
 [^■1 
 
 Jaiiuary- 
 
 ■■ 
 
 
 
 
 
 
 
 
 
 J 
 
 IT'elaru.a.ry 
 
 
 
 
 
 
 
 
 
 
 1 
 
 Vi^B 
 
 IN^TarcK 
 
 1 
 
 
 
 
 
 
 
 
 
 1 
 
 
 A.pril 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 May 
 
 
 n 
 
 
 
 
 
 
 
 It is a matter of common observation that catarrhal dis- 
 eases and, in general, those of the respiratory system are 
 more frequent during the months of low temperature and 
 excessive moisture than at other times in the year (see Chart 
 2). Whether this is due to atmospheric conditions alone, or 
 to those in conjunction with the evil effects of crowding 
 together in badly ventilated rooms, kept closed for purposes 
 of warmth, it is difficult to say ; but it would appear more 
 reasonable to consider both influences together as the predis- 
 posing conditions. 
 
 During the heated months the diseases that are most prev- 
 
48 
 
 HYGIENE OE T/^.-lXSMISS/BLE DISEASES. 
 
 •^ 
 
 
 U 
 DC 
 O 
 
 < 
 
 CQ 
 
 o 
 in 
 
 o 
 
 ■t 
 
 o 
 « 
 
 o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 •^ 
 
 
 
 
 
 
 
 
 
 
 
 '^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 OJ 
 
 Jl 
 
 
 
 
 
 
 
 
 
 
 t 
 
 o ^^^^^H 
 
 
 
 
 
 
 
 
 
 
 ■^ 
 
 ■ 
 
 
 
 
 
 
 
 
 •S4 
 
 
 
 
 
 
 ^ 
 
 
 ■ 
 
 C 
 
 o 
 
 2 
 
 I 
 h 
 
 
 <1 
 
 
 
 
 ■p 
 
 
 a; 
 
 
 
 H 
 
 b 
 
 
 
 H 
 
 •H 
 U 
 ft 
 
 K) 
 
 '-^ 
 
 
 >- 
 
 o 
 
 "^ 
 
 oc 
 o 
 
 >- 
 
 z 
 
 ^^^^^^^^^^^^^H 
 
 ■ 
 
 
 
 
 ■ 
 
 
 ■ 
 
 -g 
 
 
 
 
 
 
 
 
 
 
 ■=1. 
 
 o 
 
 O 
 
 ro 
 
 O 
 t 
 
 O 
 
 in 
 
 1 
 
 ■ 
 
 
 
 
 
 
 
 
 
 ■C' 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 J 
 
 
 
 
 
 
 
 
 
 
 
 <; 
 
 
 
 
 
 
 
 
 
 
 
 -/j 
 
 
 
 
 
 
 
 
 
 
 
 S 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 — 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f^^ 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 ■jL 
 
 
 
 
 
 
 
 
 
 
 
 
 
 '— ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
THE CAUSATION OF DISEASE. 
 
 49 
 
 alent are those connected with the digestive system. This is 
 especially the case with young children, and particularly those 
 whose food consists of materials that readily undergo fer- 
 mentation under the favorable conditions of temperature 
 afforded by the season. 
 
 In Chart 3 is shown the relative monthly fluctuation in the 
 death-rate from diarrheal diseases in the cities of New York 
 and Baltimore for the six years ending May 31, 1890, and it 
 will be seen that by far the greater proportion of deaths occur 
 in the period of excessive heat — viz., July. 
 
 The periods of greatest vegetable activity, with the subse- 
 quent period of decline, are those in which malarial diseases 
 appear most conspicuously. 
 
 Chart 4. — Showing by viotiths the seasonal variation in the occurrence 
 of malarial fever (arranged from statistics of Thayer and Hewetsori). 
 
 The foregoing diagram (Chart 4), arranged from the statis- 
 tics of Thayer and Hewetson upon malaria in Baltimore, 
 gives an accurate idea of the seasonal distribution of the cases 
 of this disease : 
 
 For reasons that cannot be satisfactorily explained, typhoid 
 fever is a disease of early autumn. While occurring to some 
 4 
 
50 
 
 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 extent throughout the year, the period of greatest disease- 
 and death-rates is usually during the months of August, 
 September, and October (see Chart 5).^ 
 
 Chart 5. — Showing by iiiotiihs the seasonal variation in the occur- 
 rejice of typhoid fever {arranged from statistics of Osier). 
 
 The acute exanthemata are much more prevalent from the 
 late autumn to the early spring than at other times in the 
 year (see Chart 6). Aside from seasonal influence per se, it 
 must be borne in mind that these are the periods in which the 
 opportunities for infection are greatest — i. c, they comprise 
 the months during which children of school age are at school, 
 and in more or less intimate contact with one another. 
 
 For the six years ending May 31, 1890, the highest average 
 death-rate for all ages in New York, Brooklyn, Boston, and 
 Philadelphia occurred in the month of July, and for children 
 under five years of age very much the higliest death-rate was 
 in this month. It is because of this striking increase in infant 
 mortality during the hot weather that the death-rates of all 
 our large cities are uniformly high in July and August. 
 
 ' Compiled from Osier's "General Analysis and Summary of 229 Cases 
 of Typhoid Fever," folins Hopkins Hospital Reports, vol. iv.. No. I. 
 
THE CAUSATION OF DISEASE. 
 
 51 
 
 With regard to seasonal influence, we find that the dis- 
 eases which are conspicuously prevalent during the colder 
 months are those that are most common in countries of 
 high latitude — i. e., having the greatest amount of cold and 
 wet weather ; while those common to our months of high 
 temperature are closely allied to those most frequent in 
 tropical climates. 
 
 Chart 6. — Showing by months the average relative proportions of 
 deaths from diphtheria and scarlatina in Philadelphia, for the six 
 years ending May ji, i8go. Rates are per 1000 deaths from all 
 causes. 
 
 
 Months 
 
 
 Diphtheria 
 
 Scarlatina 
 
 30 20 10 
 
 10 20 30 
 
 
 
 
 
 
 
 
 
 •J-u.xie ^^H 
 
 ■1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Jul;^ ^^H 
 
 r 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 ^uj^ust ^^1 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 Septemlaer ^| 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 October ^^| 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 jS"oveml3er ^^H 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 DeceiiiTaer m 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 Jaiiu.arj'- ^^^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 February ^^H 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 IVCarcli ^1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 A.pril ^^9 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 IVEa^^ HI 
 
 
 
 
 
 
 
 The Bxciting Causes of Disease. — Employing the 
 word disease in its broad sense, as comprising all departures 
 from normal physiological function and all defects of anatom- 
 ical structure, we recognize a group of chemical, physical, 
 and vital agents that may be more or less directly concerned 
 in its causation. 
 
 The term " direct " or " exciting," as applied to the causes 
 of disease, is limited to those chemical, physical, and mechan- 
 ical agencies that are capable of inducing abnormal conditions 
 of the organism without the intervention of any other modi- 
 fying factors ; and while this term is similarly applied to the 
 
52 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 vital agents that are instrumental in inducing definite patho- 
 logical conditions and clinical manifestations, it must be borne 
 in mind that without the intervention of predisposing condi- 
 tions it is improbable that the vital causes of disease are of 
 themselves capable, at any and all times, of performing their 
 characteristic pathogenic functions. 
 
 For the manifestation of their particular pathogenic powers 
 the vital agents require that the organism upon which they 
 are to act is either by nature susceptible to their influence, or 
 is rendered so through the action of the many detrimental 
 agencies that serve to diminish resistance and predispose to 
 disease. 
 
 The vital factors, while classed as the direct causes of dis- 
 eases, cannot therefore be considered as standing, independent 
 and alone, in causal relation to the processes ; and while they 
 are, in the strict sense of the word, the direct and only excit- 
 ing causes of certain specific phenomena, they still require 
 special conditions of the body that are favorable to their 
 activity and development. These conditions usually depend 
 for their existence upon one or more of the influences already 
 referred to as predisposing. 
 
 Chemical Causes. — The direct chemical causes of disease 
 may be divided into those having their origin outside the body 
 (ectogenous), and those that are created within the body 
 (endogenous) as a result of malnutrition, malfermentation, 
 and other defects of metabolism and physiological function. 
 Those originating without the body comprise the numerous 
 organic and inorganic substances of an irritating or poisonous 
 nature that possess the property of causing abnormal local 
 and con.stitutional conditions in those exposed to their influ- 
 ence. The commonest of them are the various hurtful sub- 
 stances used in certain trades, as, for example, phosphorus, 
 ar.senic, chromic, and oxalic acids, mercury and its salts, and 
 certain of the irritating coal-tar products. To this category 
 belong certain drugs, such as opium, chloral, cocain, alcohol, 
 etc., which are frequently indulged in because of their agree- 
 able effects. The poisons of particular plants, as of rhus 
 toxicodendron, or atropa belladonna^ of hyoscyani7is niger, of 
 
THE CAUSATION OF DISEASE. 53 
 
 riciiiiis, of croion tiglmin, and many others, possess likewise 
 the power of directly inducing abnormal local and general 
 conditions. To this list must be added the poisons of venom- 
 ous reptiles. 
 
 Those originating within the body (endogenous) comprise 
 a group of compounds of whose nature we are as yet but ill- 
 informed. They represent, most Kkely, intermediate products 
 in the processes of nutrition which, through physiological de- 
 fects, are not completely elaborated, and which in this state 
 and under the existing condition of physiological enfeeble- 
 ment are endowed with poisonous peculiarities ; also, the ordi- 
 nary end-products of tissue-activity that have accumulated 
 within the system as a result of structural lesions of the 
 secretory and excretory organs ; and equally as important 
 as either of the preceding, the toxic products of malfer- 
 mentations often in operation within the alimentary tract. 
 
 Physical and Mechanical Causes. — The most frequent 
 direct physical causes of disease are excessive heat, cold, and 
 moisture, while the mechanical causes are both predisposing 
 and, in the case of accident, exciting. 
 
 Vital Causes. — By the term vital causes of diseases are 
 meant those living animal and vegetable parasites which, 
 having gained access to the body, produce, as a result of 
 their development under favorable circumstances, tissue- 
 lesions that terminate in disturbance of important vital 
 functions, and frequently in local or complete death of the 
 host in which they are developing. 
 
 The disturbances that result from the invasion of the body 
 by animal parasites vary with the character, mode of nutri- 
 tion, life cycle, and location of the invading organism. In the 
 one case they may manifest themselves through symptoms 
 that point more particularly to the circulating blood, in 
 another by more or less grave disturbances of nutrition. 
 Again, nervous irritability, at times extreme, will be observed. 
 In special instances marked and persistent diarrhea results ; 
 while with other forms of animal parasites the results of their 
 presence appear to be due mainly to the mechanical irritation 
 
54 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 caused by their lodgement in the internal viscera and in the 
 organs of the special senses. 
 
 Thus, for instance, we observe the nutritive disturbances, 
 the emaciation and the nervous accompaniments of the in- 
 vasion of the body by the teniae ; the anemia, often extreme, 
 that results from the activity of the host of blood-sucking 
 strongylidai which attach themselves to the mucous mem- 
 brane of the upper part of the small intestine in the disease 
 ankylostomiasis ; the alarming symptoms that are associated 
 with the occasional obstruction of the larger lymphatic chan- 
 nels by filaria sanguinis honiinis or its embryos ; the suppu- 
 ration and ulceration consequent upon the lodgement of the 
 guinea-worm in the subcutaneous tissues ; and the disturbance 
 of function that occurs from the presence of cysticerci in the 
 central nervous system and organs of special sense. 
 
 As we shall learn later, the niodiis operandi of disease-pro- 
 duction by animal parasites differs veiy materially from that 
 of the vegetable micro-organism. 
 
 Bacteria. — For the human being, and many lower animals, 
 the most important of the vegetable parasites that are directly 
 concerned in the production of disease are the bacteria. 
 
 Bacteria are the unicellular micro-organisms that mul- 
 tiply by the simple process of transverse division. They are 
 concerned in a great many phenomena other than that of 
 disease-production. The majority of them are benefactors 
 rather than enemies to mankind. They are nature's scaven- 
 gers, being the underlying cause of all processes of disin- 
 tegration and decomposition through which dead organic 
 matter is converted into simpler compounds suitable for the 
 nutrition of more highly organized vegetables. It is largely 
 through the activities of bacteria that the equilibrium of the 
 chemical composition of the atmosphere is maintained, for 
 the amount of carbonic acid thrown into the atmosphere as a 
 result of animal respiration alone is insufficient to meet the 
 demands of the growing chlorophyl plants. The deficit is 
 made up through the activities of bacteria in converting 
 dead organic matter into this gas as one of the end- 
 products of tlie process of decomposition. It is to the 
 
THE CAUSATION OF DISEASE. 55 
 
 activities of bacteria that commerce is indebted for important 
 products — viz., for certain of the organic acids, and for prac- 
 tically its entire supply of saltpetre. In agriculture their role 
 is no less important. They are the instruments through 
 which are perfected the processes in operation in nature's - 
 great laboratory — the upper layers of the soil — which are 
 destined to supply the food for growing crops. Through 
 their association the leguminous plants are enabled to obtain 
 a portion of their supply of nitrogen from the gaseous 
 nitrogen of the air — a phenomenon which was until com- 
 paratively recently supposed to be impossible, the nitrogen 
 of the atmosphere having always been considered to be of 
 no biological significance. 
 
 Since the discovery of bacteria by Leeuwenhoek in 1668- 
 1675, our knowledge of these parasites has continuously 
 developed until we are now pretty familiar with the majority 
 of their important peculiarities. 
 
 In addition to the functions of bacteria, mentioned above, 
 there remains to be considered their role in the production of 
 disease. Diseases that depend for their existence upon the 
 presence of bacteria in the tissues are known as infections 
 diseases, and the process by which they are caused is known 
 as infection. As here employed, the term infection refers 
 more especially " to the morbific agents causing disease, and 
 implies nothing as to the mode of transmission of these 
 agents." A contagious disease is one transmissible from 
 individual to individual by immediate or direct contact. Con- 
 tagious diseases, like infectious diseases, are dependent upon 
 the activities of vital pathogenic agents in the tissues, though 
 in the case of the majority of the commonest contagious 
 maladies, like small-pox, measles, scarlatina, and rotheln, the 
 nature of these agents is unknown. Miasmatic diseases result 
 from the invasion of infectious agents from without, which 
 cannot always be traced either directly or indirectly to some 
 other case of the same disease. Malaria may be regarded as 
 a typical miasmatic disease. 
 
 It is evident that the term infectious, as referring to the 
 
56 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 causation of disease, is broader than the term contagious, 
 Avhich relates only to the manner of transmission. 
 
 As the term is ordinarily understood mfectioiis diseases, as 
 distinct from the contagious, are disseminated indirectly — /. e., 
 in a roundabout way, by means of the water, the soil, or the 
 food to which the mcfrbific agents from a case of infectious 
 disease have gained access ; while the contagious diseases 
 spread, as stated, by direct contact from a sick to a healthy 
 individual. The miasmatic diseases follow the rule given for 
 infectious diseases in general, though they are not always 
 dependent upon pre-existing cases of the disease. It is mani- 
 fest from what has been said, that all contagious diseases are 
 infectious, but that many of the infectious diseases are not 
 contagious. 
 
 Typhoid fever, cholera, and the common suppurations are 
 examples of non-contagious, infectious diseases. 
 
 Erysipelas, pneumonia, tuberculosis, glanders, and diph- 
 theria, though not usually contagious, may become so under 
 favorable conditions. Small-pox, measles, scarlatina, rotheln, 
 mumps, and varicella are infectious diseases that are notably 
 contagious. 
 
 " Whether or not an infectious disease is contagious in the 
 ordinary sense depends upon the nature of the infectious 
 agent, and especially upon the manner of its elimination from 
 and reception by the body " (Welch). 
 
 The proof necessaiy to demon.strate a causal relation 
 between a given bacterial species and a disease is embodied 
 in the postulates formulated by Koch, to the effect : 
 
 1. That the micro-organism under consideration shall 
 always be found in the diseased tissues in such numbers, and 
 in such relations to these tissues, that they can reasonably be 
 assigned an etiological relation to the process. 
 
 2. That the micro-organism shall be isolated from the 
 disea.scd tissue in pure cultures. 
 
 3. That the pure cultures of the micro-organism shall be 
 capable, when inoculated into susceptible animals, of repro- 
 ducing pathological lesions identical with those from which it 
 was originally isolated. 
 
THE CAUSATION OF DISEASE. 5/ 
 
 4. That the micro-organism shall be found in the lesions 
 produced by inoculation 
 
 It has been suggested that to these requirements be added : 
 " That the organism be not found in other pathological con- 
 ditions ; " and " that it is not one of the harmless commensal 
 species that are found in the intestine or on the skin." The 
 inadvisability of introducing the latter two requirements is 
 at once apparent, as we know that several pathogenic species, 
 particularly those concerned in the causation of suppurative 
 processes, and many of those grouped as septicemic bacteria, 
 are at times concerned in the production of pathological 
 lesions that differ very materially the one from the other. 
 For instance, streptococcus pyogenes may under one set 
 of conditions cause erysipelas, under another phlegmonous 
 inflammation ; micrococcus lanceolatiis is known to be the 
 cause of acute lobar pneumonia, of acute endo- and peri- 
 carditis, of peritonitis, of cerebrospinal meningitis, of suppura- 
 tions of the middle ear, and of circumscribed abscess-forma- 
 tion. The members of the group of hemorrhagic septicemia 
 bacteria, while usually instrumental in producing an acute 
 general infection, may under special circumstances cause a 
 condition that is conspicuous for its local manifestations, and 
 the extent of general infection may be very insignificant. 
 
 With regard to the so-called " harmless commensal " 
 species, we know that under various circumstances they may 
 exhibit pathogenic properties. A conspicuous illustration is 
 found in the common bacillus of the colon {bacillus coli 
 connnunis) — an organism present in the colon of all human 
 beings and of many lower animals. Under ordinary circum- 
 stances these organisms exist as harmless saprophytes, but 
 under conditions that bring about lesions of the intestinal 
 mucous membrane, or those causing general reduction of 
 vital resistance, this organism may exhibit disease-producing 
 properties. 
 
 In the mouth-cavity of a very large proportion of normal 
 human beings micrococcus lanceolatus (pneumococcus) is 
 found. This organism, like the one just mention&d, may 
 prove to be of no danger to the host in which it is living, or 
 
58 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 it may, through the aid of predisposing factors, become the 
 cause of a variety of pathological conditions. 
 
 In the skin of many individuals the pyogenic cocci may be 
 demonstrated. These too may continue to exist as innocent 
 saprophytes, or they may, under favorable conditions, exhibit 
 their disease-producing powers. 
 
 We see that a given species may, with varying conditions, 
 cause lesions of a dissimilar kind ; and we also see that the 
 so-called " innocent, commensal " species may at times take 
 on pathogenic properties. 
 
 With regard to the postulates of Koch, it is manifest that 
 their fulfilment is possible only in a limited number of cases. 
 
 Some of the most important diseases that are known clin- 
 ically to be of an infectious nature have thus far eluded all 
 efforts to discover their causative factors. In others micro- 
 organisms may be constantly found, and these micro-organ- 
 isms may be exclusively found in these diseases, though no 
 success has followed the efforts to isolate and cultivate them. 
 In still other groups definite bacterial species may be found, 
 isolated and cultivated, and yet the reproduction of the dis- 
 ease by inoculation into lower animals has either been impos- 
 sible, or only in part satisfactory, owing to the difficulty of 
 faithfully reproducing in animals used for inoculation the 
 clinical symptoms and pathological lesions, by which the dis- 
 eases from which the bacteria were isolated are characterized 
 in man. 
 
 There are many important diseases to which mankind is 
 liable that do not occur spontaneously and cannot be pro- 
 duced in animals that are used for purposes of experimentation. 
 There is no evidence that animals ever suffer spontaneously 
 from such diseases as typhoid fever, Asiatic cholera, leprosy, 
 syphilis, malaria, yellow fever, small-pox, measles, etc., and 
 it is seen to be in the main impossible, even in those animals 
 that are in general most susceptible to infection, to produce 
 by inoculation clinical and pathological manifestations that are 
 a correct reproduction of those that characterize these dis- 
 eases in human beings. 
 
 For the group of septicemias that occur in animals, such 
 
THE CAUSATION OF DISEASE. 59 
 
 as chicken cholera, rabbit septicemia, anthrax, and mouse 
 septicemia ; for certain suppurative processes ; for diphtheria, 
 for glanders, for gonorrhea, and for tuberculosis, the proof is 
 conclusive, and all the requirements have been met ; but for 
 cholera, typhoid fever, malaria, and leprosy, and for amoebic 
 dysentery, and certain other protozoal diseases, the postulates 
 of Koch have only in part been fulfilled. It should be said, 
 with regard to Asiatic cholera and typhoid fever, that by par- 
 ticular methods of experimentation pathological conditions 
 somewhat analogous to those seen in man have been pro- 
 duced, but in general the results thus obtained are not fairly 
 comparable, either etiologically, pathologically, or clinically, 
 with those observed in human beings affected with these mal- 
 adies. In one or two instances cholera has occurred in 
 human beings who have purposely or accidentally swallowed 
 cultures of the cholera spirillum. 
 
 There are a number of infectious diseases, including those 
 dependent upon the presence of protozoa in the tissues, in 
 which only the first of the requisite proofs has been estab- 
 lished. In these diseases there are constantly and exclusively 
 present micro-organisms that are capable of microscopical de- 
 monstration, but of which none have been isolated in culture, 
 and the diseases have not been satisfactorily reproduced in 
 animals. The most important of the group are malaria, 
 amoebic dysentery, relapsing fever, leprosy, and, possibly, 
 syphilis. The majority of the commonest infectious diseases 
 have eluded all efforts to discover their specific causative 
 agent. Of these may be mentioned yellow fever, measles, 
 scarlet fever, small-pox, varicella, mumps, dengue, and ty- 
 phus fever. 
 
 As regards their life-processes, bacteria lead either a 
 saprophytic or a parasitic existence. A " saprophyte " is 
 one that grows upon dead organic matter — that is, it devel- 
 ops without a living host ; while a " parasite " is one that de- 
 pends for its existence upon the conditions offered by either 
 a living animal or plant, in or on which it develops. There 
 are species that live with — /. e., that are commensal with — 
 both animals and plants. They are saprophytic in that they 
 
6o HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 do not live at the expense of their host and have no deleteri- 
 ous action ; in fact, they are frequently of importance to their 
 host by aiding in the performance of normal physiological 
 functions, through their symbiotic association. 
 
 Both saprophytes and parasites have their obligate and 
 \\\€\\ facultative varieties. In this sense the term " obligate " 
 as applied to a saprophyte implies that it can live only on 
 dead matter ; when applied to a parasite, that it can develop 
 only within a living host. The designation " facultative " as 
 applied to a parasite or a saprophyte implies that these organ- 
 isms possess the power of leading either a parasitic or sapro- 
 phytic form of existence, according to circumstances. 
 
 The parasitic bacteria that are concerned in the production 
 of those diseases in which all the postulates of Koch have 
 been fulfilled 2S& facultative saprophytes, as it is possible to 
 cultivate them outside a living host on dead organic nutritive 
 media. Had they been obligate parasites this would have 
 been impossible, and it may be due to their obligate nature 
 that certain, presumably present, species of bacteria elude our 
 efforts to cultivate them. 
 
 This power of adaptability to surrounding conditions which 
 is common to the facultative saprophytes ; the fact that after 
 prolonged existence under saprophytic conditions many of 
 them experience modifications in those pathogenic functions 
 that characterize their parasitic life ; the fact that by a variety 
 of artificial procedures modifications of other important bio- 
 logical functions may be induced, have served as a basis for 
 occasional discussion relating to the fixity of what are usu- 
 ally considered type-characteristics, and the advisability of 
 con.sidering the different specific varieties of bacteria as definite 
 and distinct species. 
 
 As generally employed by biologists, the term " species " 
 implies " an individual which differs, or collectively, those 
 individuals which differ specifically from all the other mem- 
 bers of the genus, and which do not differ from one another 
 in size, shape, color, and so on, beyond the limits of individual 
 variability, as tho.se animals and plants which stand in the 
 direct relation of parent and offspring, and perpetuate certain 
 
THE CAUSATION OF DISEASE. 6 1 
 
 inherent characteristics intact or with that little modification 
 which is due to conditions of environment." 
 
 In the sense of this definition the individual peculiarities of 
 the recognized pathogenic bacteria are of sufficient constancy 
 to justify the opinion that they represent functions of definite 
 species. 
 
 Nevertheless, variations both of form and function are 
 known to occur under the influence of a variety of condi- 
 tions. Variations in function are, as a rule, much more 
 lasting and more frequently encountered than are variations 
 in form. 
 
 The majority of the variations that one observes are the 
 result of injurious conditions concomitant with growth under 
 artificial circumstances, such, for example, as prolonged sapro- 
 phytic existence of facultative saprophytes ; growth under 
 unsuitable conditions of nutrition ; the influence of dele- 
 terious agents, as oxygen, light, heat, and hurtful chem- 
 icals ; association with antagonistic species ; the influence 
 of the products of growth of other bacteria ; and the harm- 
 ful influence of certain animal fluids and tissues. 
 
 The variations in form most commonly seen are tempo- 
 rary, are the result of unfavorable conditions of life and, 
 as a rule, disappear under the influence of normal environ- 
 ment. The commonest of such morphological changes are 
 those indicative of degenerative processes in the bodies of 
 the bacteria themselves, resulting in the occurrence of the 
 so-called " involution forms." 
 
 It is possible by prolonged heating and by the application 
 of particular chemicals to deprive certain bacteria of their 
 power to form spores. By special methods of cultivation 
 short bacilli have been induced to grow as longer threads. 
 The color characteristics of certain chromogenic species have 
 been modified, and under varying conditions of nutrition fluct- 
 uations in the function of fermentation are observed. By 
 artificial processes, as prolonged heating to 42° C, and by 
 the action of certain chemicals in a dilute form, bacilhis 
 anthracis may be in part or wholly robbed of its pathogenic 
 properties. On the other hand, exaltation in virulence is 
 
62 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 often seen to follow the repeated passage of attenuated 
 varieties of bacteria through susceptible animals. The same 
 result sometimes follows the mixing of attenuated varieties 
 with other species of bacteria and with certain chemical 
 agents. 
 
 As a general rule, the structurally modified species revert 
 to their normal morphology when placed under favorable 
 conditions. This is true also for certain functional modifica- 
 tions, though those that appear slowly after the continued 
 action of modifying influences — such, for instance, as pro- 
 longed heating — are apt to be lasting and, in some cases, 
 hereditary. 
 
 That modifications of important characteristics appear 
 naturally there can be no doubt. The most conspicuous 
 example of this is the loss of virulence experienced by 
 many pathogenic species when expelled from the diseased 
 body and forced to compete for existence with the host of 
 normally saprophytic forms under the adverse circumstances 
 offered by the soil, water, and other places in which they find 
 themselves. Striking examples of this are seen in the ba- 
 cillus of typhoid fever, the colon bacillus, the spirillum of 
 Asiatic cholera, the streptococcus of eiysipelas, viicrococciis 
 lanceolatus (pneumococcus) and the group of organisms con- 
 cerned in septic infections. 
 
 Notwithstanding all this there has not as yet been pre- 
 sented any trustworthy evidence to the effect that by any of 
 the known natural phenomena or artificial processes one 
 definite bacterial species, as recognized by the available 
 methods of study, may be changed into another, such, for 
 instance, as the anthrax into the subtilis bacillus or the colon 
 bacillus into that causing typhoid fever, though intermediate 
 varieties suggesting probable graduations in certain peculiari- 
 ties may frequently be encountered. 
 
SECTION II. 
 THE TRANSMISSIBLE DISEASES. 
 
 This section comprises brief sketches of the commoner 
 transmissible diseases, with a summary of points that are of 
 importance to the hygienist, such as the causation, modes of 
 dissemination, portals of infection, prophylaxis against, and 
 the geographical distribution of such diseases. 
 
 In this summary no attempt is made to treat of the various 
 infectious diseases in full. The object is to emphasize that 
 knowledge which is essential to a rational prophylaxis against 
 their spread — such, for instance, as that relating to the agents 
 concerned in "their causation; when and where such agents 
 are to be sought for ; the manner in which they are expelled 
 from the diseased and received by the healthy body ; the 
 steps to be taken to prevent the dissemination of the morbific 
 factors ; the geographical distribution and the racial suscepti- 
 bilities to and immunity from such diseases. 
 
 TYPHOID FEVER. 
 
 Cause. — The bulk of the evidence points to bacillus typho- 
 sus of Eberth and Gaffky as the specific cause of this disease. 
 
 Bacillus typhosus is a short, actively motile, flagellated, 
 non-spore-forming, non-Hquefying rod with rounded ends 
 (Fig. i). It does not possess the property of fermenting 
 glucose or lactose, nor of producing indol as a product of its 
 growth in the ordinaiy nutrient media. It does not coagu- 
 late milk. It is destroyed in ten minutes by a temperature 
 of 60° C. It is not destroyed by freezing. When inoculated 
 
64 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 into animals the results are irregular. Most frequently this 
 has no effect. Occasionally evidences of intoxication rather 
 than genuine infection are obtained. Exceptionally, a speci- 
 men will be obtained of so high a degree of virulence that it 
 possesses the property of infecting. By none of the ordinary 
 methods of inoculation are conditions produced in animals 
 
 Fig. I. — Bacillus typhosus: /, stained by ordinary methods; //, flagella stained 
 by Loffler's method. 
 
 that are in any way, either clinically or pathologically, com- 
 parable to those found in the human being suffering from 
 typhoid fever. By a few investigators lesions of the intestine 
 .similar to those seen in the human being are claimed to have 
 been produced by special methods of inoculation in particular 
 .species of animals. As intimated, these results are by no 
 means common. 
 
 Mode of Dissemination. — Since the specific micro- 
 organism causing the disease is contained in the discharges 
 from the bowels of typhoid patients, and is apparently at 
 times present in the urine also, it is manifest that all sub- 
 stances with which these matters come in contact may be- 
 come specifically contaminated and be capable of conveying 
 the disease. 
 
 Typhoid fever is disseminated in a variety of ways, but 
 most frequently through the water, the soil, and through 
 
TYPHOID FEVER. 
 
 65 
 
 _ 
 
 JO 
 
 M 
 
 ^ 
 
 Oi 
 
 OS 
 
 ^ 
 
 CO 
 
 CD 
 
 
 
 - 
 
 !i 
 
 Ci 
 
 h^ 
 
 01 
 
 Ci 
 
 -1 
 
 ^ 
 
 to 
 
 No. of Deaths 1 
 per 10,0001 
 
 
 1^ 
 15 
 
 
 ^^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Jlmiicli 
 
 
 
 S" 
 in 
 
 
 
 
 Q. 
 
 $ 
 
 i> 
 
 Q. 
 
 CD 
 
 Z! 
 
 a> 
 S_ 
 
 CD 
 
 tn 
 
 c: 
 -a 
 -0 
 
 
 ' CD 
 
 
 b< 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Danhic 
 
 
 It? 
 
 
 ■>f^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Ffaiikfort 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 liiesliiu 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Hamburg 
 
 
 
 
 CO 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Berlin 
 
 
 1 
 
 
 05 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Brussels 
 
 
 
 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 London 
 
 
 
 CO 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 28 larjre 
 Kng. Cities 
 
 
 
 CO 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 New York 
 
 
 1 
 
 
 
 b» 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Brooklyn 
 
 ■81 
 
 
 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Vienna 
 
 
 
 
 
 
 
 
 05 
 
 ■«5 
 
 
 
 
 
 
 
 ) 
 
 
 
 
 
 Phila., 18S5.1890 
 
 
 
 ^* 
 
 ^ 
 
 
 ^* 
 
 
 ^^ 
 
 3a 
 
 r7 T 
 
 Va 
 
 
 
 
 
 
 
 
 
 <35 
 
 
 1 
 
 
 
 * 
 
 
 
 
 
 Wasliing;ton,1885-90 
 
 
 
 ^* 
 
 ^ 
 
 
 ^5 
 
 ^ 
 
 1 
 
 
 p 
 
 
 
 
 
 
 
 
 
 Paris 
 
 
 
 CO 
 $. 
 
 
 
 e: 
 
 ct> 
 
 $ 
 
 ct> 
 v> 
 
 
 ct> 
 ■^ 
 
 i" 
 
 -a 
 
 fD 
 
 cd' 
 
 
 '<' 
 </> 
 
 CO 
 
 $ 
 
 fD 
 
 
 ■ 
 
 I 
 
 
 
 
 
 
 
 Marseilles 
 
 
 Cn 
 
 
 
 
 
 
 
 
 Turin 
 
 
 ;-» 
 
 
 
 
 
 
 
 
 
 
 \aples 
 
 1881.1884 
 
 
 CO 
 
 
 
 
 
 Palermo 
 
 1881-1884 
 
 
 Catania 
 
 
 JO 
 C,1 
 
 
 r^ 
 
 ar, 
 
 ,« 
 
 81. 
 
 ;55 
 
 2 
 
 281 Cities 
 in Italy 
 
 
 to 
 to 
 
 
 
 
 
 
 
 
 5t,Petevsburg 
 1883.1881 
 
 
 H 
 
 ■ 
 
 L 
 
 P 
 
 ■ 
 
 or 
 
 to 
 
 
 
 Rifra 
 
 1881-1882 
 
 
 
 
 to 
 
 
 
 
 
 
 
 Budapest 
 1877-1881 
 
 
 
 to 
 
 bo 
 
 
 
 
 
 
 
 20 German 
 Cities 1878.82 
 
 
 K^-o 
 
 fe? 
 
 ^« 
 
 pphjfram 
 
 1 
 
 cis 
 
 rcr 
 
 IS( 
 
 ihc 
 
 -ue 
 
 yrom 
 
 d 
 
 New Orleans 
 
 
 
 QO 
 
 
 - 
 
 4b, 
 
 inda 
 
 %t 
 
 Wc 
 
 fer 
 
 -SU 
 
 PP 
 
 ly 
 
 
 
 Baltimore 
 
 
 ■ 1 
 
 CO 
 
 
 
 
 
 
 
 
 
 
 Cincinnati 
 
 ^„ 
 
 M 
 
 CO 
 
 If- 
 
 CI C5 
 
 ^1 00 
 
 CO 
 
 1— 
 
 rt 
 
 Ci 
 
 ;;2 
 
 S 
 
 - 
 
 -t 
 
 s 
 
 s 
 
 No. of Deaths 1 
 perl 0,000 1 
 
 ^ 
 
 S" 
 
 ^ 
 
 
 o 
 
 1 o 
 
 Oo O 
 
 rt-' "^ Si 
 
 sT '^ 
 
 
 Charts 7 and 8 are from "The Influence of Sewerage and Water-Supply 
 on the Death-Rate in Cities," by Erwin F. Smith, Supplement to the Annual 
 Report of the Michigan State Board of Health, 1885. 
 
 5 
 
66 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 green \'egetables, salads, etc., that are eaten raw and that 
 have been fertilized with human manure. It is not infre- 
 quentl}' disseminated by milk which has become infected 
 as a result of the use in the dairy of water polluted with 
 typhoid evacuations. Attention has recently been directed 
 to raw oysters as a possible disseminator of this disease. 
 The outbreak of typhoid fever at Wesleyan College, to 
 which Conn directed attention/ is believed by him to have 
 been caused by the use of oysters that had been "fattened" 
 in waters polluted with typhoid evacuations ; an outbreak 
 of the disease in England is believed by Broadbent^ to be 
 due to the same cause ; and numerous experiments point to 
 the possibility of the disease being conveyed in this way.^ 
 The refuse of food that has been used by typhoid patients 
 should be looked upon with suspicion, and should under no 
 conditions be eaten by others in attendance. 
 
 There is no evidence that the disease is disseminated 
 through the air. Milk and other foods may be infected by 
 insects that have been in contact with fresh typhoid stools, 
 and thus become means for conveyance of the infection. 
 
 Portals of Infection. — The disease is not contagious. 
 It is not spread by breathing the same atmosphere with a 
 typhoid patient. 
 
 Infection occurs by way of the alimentary tract — i. c. it 
 results from actually swallowing materials that have come 
 directly or indirectly from the bowels of individuals affected 
 with the disease. We have no evidence that it occurs in 
 any other way. 
 
 Prophylaxis. — It is now generally recognized that the 
 most potent factors in diminishing the widespread occurrence 
 of this disease in communities are an unpolluted general 
 water-supply and a reliable system of sewage disposal (see 
 Charts 7 and 8). The conspicuous decline in the mortality 
 from typhoid fever that has followed the adoption of such 
 
 ' Med. Record, Dec. 15, 1894. ^ j^,.j[ j^j^^i^ Jour., Jan. 12, 1895. 
 
 * See Supplement to Report of Medical Officer of Local Gov. Board, 1894- 
 95; also Brit. Med. Jour., 1896, report by G. E. Cartwright Wood; also 
 Science, Nov. 27, 1898. 
 
TYPHOID FEVER. 
 
 67 
 
 
 !'■; i 1 M n l-M ! ! M 1 1 1 
 
 ■■■■ 7859 
 
 2 
 c= 
 z 
 
 
 3: 
 
 PPiWiJBPWPWJ 
 
 ; 1 7860 
 1 7865 
 
 ■BnauKEIIiTL. 
 
 \a66 
 1873 
 
 iTrf^-nimi 
 
 
 
 1874 
 1881 
 
 
 ■r^T: n 
 
 
 
 
 '''%72 
 
 > 
 
 z 
 -1 
 
 N 
 -0- 
 
 
 
 
 
 1873 
 1884 
 
 
 1 1 -B 
 
 
 
 1863 
 7875 
 
 00 
 
 =a 
 m 
 cr> 
 
 I— 
 
 i 1 
 
 1^ 
 
 
 
 
 
 
 7876 
 7880 
 
 ! ' .1 
 
 L 
 
 
 
 
 
 
 7887 
 1884 
 
 
 T 
 
 
 
 
 1851 
 1866 
 
 33 
 
 3> 
 
 :k 
 
 -n 
 
 
 
 
 1 I- 1 
 
 ■1 
 
 IS 
 
 D 
 
 
 
 
 ""l876 
 
 ^»nii 
 
 
 
 
 
 
 1877 
 1884 
 
 u pj" 
 
 ai 
 
 f 
 
 
 
 1854 
 1872 
 
 CO 
 
 m 
 =0 
 
 
 
 
 1873 
 1877 
 
 : 1 i 
 
 ■ p 1 
 
 
 
 1878 
 1884 
 
 : 1 
 1 
 
 
 1866 
 1873 
 
 < 
 m 
 
 z 
 z 
 
 
 ^\ 
 
 ■^ 
 
 
 
 
 
 
 1874 
 1879 
 
 
 
 
 
 
 
 1880 
 1884 
 
 
 h 
 
 
 1865 
 1869 
 
 30 
 
 c: 
 
 CO 
 
 a> 
 ro 
 
 r- 
 
 
 
 
 1870 
 1874 
 
 
 '' '9IHH 
 
 
 
 7875 
 1884 
 
 — - 
 
 i-i:.i i-.-i i 
 
 11-^ 
 
 
 1838 
 1858 
 
 s 
 
 Z 
 
 a 
 
 
 z 
 
 , i 
 
 ■.■^rTni 
 
 a 
 
 
 1859 
 1865 
 
 
 ■| 
 
 N 
 
 
 
 1866 
 1884 
 
 I^HIHi^^^l<= 
 
 
 
 1850 
 1870_ 
 
 p> 
 -0 
 
 ! ■ : 
 
 - -! 1 
 
 
 
 
 
 
 .- 
 
 1871 
 1880 
 
 
 
 
 
 
 
 
 1881 
 1884 
 
 ■■'1: : ; 1 
 
 
 
 1850 
 1871 
 
 m 
 
 z 
 
 CD 
 
 3> 
 Z 
 
 
 i 
 
 1- 
 
 w- 
 
 
 
 
 
 1872 
 1875 
 
 
 1 
 
 
 
 
 
 
 
 1876 
 1883 
 
 ^ i i 
 
 i3 
 
 
 
 
 
 
 
 1847 
 1859 
 
 Z 
 
 —1 
 -< 
 
 1 1 -l-i 
 
 in 
 
 
 
 
 
 
 1860 
 1869 
 
 \ \ 
 
 S 
 
 
 
 
 
 
 
 "'%84 
 
 \ n i ; i ^i j r.i. i i 1 1 i'" 
 
 IS '"1849 
 
 05 
 
 CO 
 
 —1 
 
 - z 
 
 . i i ' 
 
 1-1 
 
 p 
 
 
 
 
 1850 
 1859 
 
 1 - - 1 " 
 
 i; 
 
 
 
 
 
 1860 
 1869 
 
 
 ni^ 
 
 
 
 
 
 1870 
 1884 
 
 ! M ■- 
 
 
 
 
 
 
 
 
 
 1843 
 1862 
 
 =0 
 
 - 
 
 
 
 z 
 
 i 
 
 Bs 
 
 
 
 
 
 
 
 
 
 1863 
 1879 
 
 y^ 
 
 
 
 
 
 
 
 
 
 1880 
 1884 
 
 3| 00 
 
 -p' 
 
 CJ 
 
 a- 
 
 
 cc 
 
 CO 
 
 — 
 
 rso CO 4^ cji cT) -^ 
 
 00 CO — Ppr W.OOO 1 
 
 ^ 
 
 ^ 
 
 S- 
 
 
 
 
 
 
 
 
 
 
 
 ?3 
 
 
 ft 
 
 ft 
 
 
 1^ 
 
 
 
 -^ 
 
 ^ 
 
 
 
 
 
 :h 
 
 5" 
 
 ■^ 
 
 ■^ 
 
 "^ 
 
 ^ 
 
 ^ 
 
 ft 
 
68 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 measures in man}' of the larger cities, particularly in Europe 
 and Great Britain, and in a few in this country, can leave 
 little room for doubt as to the correctness of this view (see 
 Chart 8). 
 
 In districts where the water-supplies are obtained from 
 shallow wells there is probably no more active cause of the 
 spread of this disease than pollution of the soil by cesspools 
 and privies. In such localities the soil is often saturated with 
 the contents of privies into which not only normal intestinal 
 contents find their way, but also the evacuations of individ- 
 uals suffering from this malady. It is therefore plain that 
 the most important domestic prophylactic measures consist 
 in the disinfection of the bowel-discharges from all suspicious 
 cases of intestinal trouble, and the subsequent disposal of such 
 discharges by some method that will remove them quickly 
 and completely from the neighborhood of human habitations. 
 This latter is to be accomplished in cities only by means of 
 an efficient sewage system. In the country, where sewers do 
 not exist, reliance must be placed in the disinfection of the 
 stools (see chapter on Disinfection) and their final disposal 
 upon the soil. 
 
 The domestic prophylactic measures consist, again, in care- 
 ful disinfection of all intestinal contents before they are finally 
 disposed of This point cannot be too strenuously urged ; as 
 the stools of typhoid patients are the only known source of 
 the disease, and as they are easily rendered inert, a great deal 
 may be done in reducing the frequency of the disease by faith- 
 ful attention to this point. 
 
 All body- and bed-clothing of the patient that has become 
 soiled by intestinal discharges is to be removed at once and 
 placed directly into a covered vessel, preferably one contain- 
 ing a cold solution of carbolic acid in water, the strength 
 being 3 per cent. The towels, napkins and, in fact, all 
 wash-goods when taken from the patient are to be similarly 
 treated. They should remain in this solution for about two 
 hours, when they may be laundered in the usual way. 
 
 If it is desirable to subject linen or muslin articles that are 
 stained by blood or fecal matters to the disinfecting action of 
 
TYPHOID FEVER. 69 
 
 either steam or boiling water, the stains should first be re- 
 moved. This is easily accomplished by soaking them for 
 about two or three hours in a cold 3 per cent, solution of car- 
 bolic acid and finally rinsing them thoroughly in a fresh por- 
 tion of the same solution. This removes all stains. The 
 articles may then be subjected to further processes of disin- 
 fection, if desired, by either boiling or steaming in a steam 
 disinfector. Unless the stains are first removed, the action 
 of moist heat renders them permanent, and they cannot be 
 subsequently removed by any of the ordinary processes of 
 laundering. 
 
 The eating utensils, of which the patient should be sup- 
 plied with a set for his exclusive use, are to be scalded thor- 
 oughly with boiling water after each meal. The refuse of 
 meals is to be at once scalded or burned. 
 
 After attending the patient the nurse should carefully rinse 
 her hands in a i : lOOO solution of corrosive sublimate, after 
 which they should be thoroughly washed in warm water and 
 soap, and scrubbed with a nail-brush. 
 
 All valueless articles used about the patient, as the toilet 
 paper, or rags used in wiping or bathing the nates, should be 
 burned as soon as used. 
 
 In times of epidemic or in localities in which the disease is 
 more than usually prevalent, all water and milk should be 
 heated to from 60° to 70° C. for at least fifteen minutes before 
 being drunk. It should be cooled, not by the addition of ice, 
 but by placing it in the ice-chest in a vessel that has been 
 previously scalded. 
 
 In localities where human manure is used as a fertilizer, all 
 green vegetables used as salads should be regarded with sus- 
 picion. Since the organism causing the disease is easily de- 
 stroyed by heat, there is no more useful aid to prophylaxis 
 than the use of boiling water. 
 
 Geographical Distribution, Season, Sex, Age, etc. 
 — The disease occurs in all countries, perhaps more fre- 
 quently in temperate than in countries presenting the ex- 
 tremes of atmospheric heat and cold. It is a disease of late 
 summer and early autumn, the greatest number of casefe usu- 
 
70 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 ally occurring between the latter part of July and the early 
 part of October, though a few cases may be, and often are, 
 irregularly scattered throughout the year. 
 
 Men are somewhat more frequently affected than women. 
 It is a disease of youth and early adult life, being compara- 
 tively infrequent before the age of fifteen and after forty-five 
 years. 
 
 Though endemic in all countries, it is not unusual to en- 
 counter local epidemics, and the most frequent cause of such 
 epidemics is the domestic use of polluted water, though in- 
 fected milk has on various occasions been shown to be the 
 disseminating factor. 
 
 It may serve a useful purpose to present the details of 
 several of the classic, water-borne outbreaks, in order to 
 illustrate the lines along which evidence pointing to their 
 causation has been accumulated. 
 
 Epidemics of Typhoid Fever. — The Lausen Epi= 
 demic. — Conspicuous among them may be mentioned the 
 oft-cited outbreak of typhoid fever in Lausen in Switzerland. 
 This village, prior to the outbreak to which reference is made, 
 had never been visited by an epidemic of typhoid fever, and 
 for years there had not been known a single sporadic case of 
 the disease. In 1872 typhoid fever appeared in the village, 
 and before its disappearance about 17 per cent, of the inhabi- 
 tants had been attacked. 
 
 Lausen is situated in the province of Basle just north of 
 the mountain ridge Stockhalden (Fig. 2), which separates it 
 from the Fiirlerthal. In a solitary farm-house in this valley 
 lived a peasant, who was attacked with typhoid fever on June 
 10, after having been away on a visit. Between June 10 and 
 Augu.st a girl and the farmer's wife and son, all inmates of 
 the same house, were attacked with the same disease. On 
 Augu.st 7 the disease appeared in Lausen and almost simul- 
 taneously 10 individuals were stricken down ; during the 
 ne.xt ten days 57 persons were affected ; by the end of the 
 fourth week the epidemic numbered 100 cases, and at its 
 close in October 130 of the 780 residents of the town had 
 suffered from the disease. In addition to this, 14 children, 
 
TYPHOID FEVER. 
 
 71 
 
 Fig. 2. — Plan of Lausen and vicinity. 
 
72 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 who had been spending their holidays in the town, developed 
 the disease after their return to school. 
 
 The cases were pretty evenly distributed throughout the 
 village, with the exception of six houses. These six houses 
 had their own private wells from which their domestic water- 
 supply was drawn. This fact directed suspicion to the source 
 from which the town drew its water-supply. This supply 
 came from a spring at the foot of the north side of the Stock- 
 halden ridge which separated Lausen from the farm-house to 
 which reference has been made. Observations upon a brook 
 in the Fiirlerthal, near which the peasant lived, and of the 
 water-supply of Lausen gave rise to the suspicion — ulti- 
 mately proved to be correct — that there might be a direct 
 communication between the two. It had been noted that, 
 ten years previously, a hole had spontaneously formed 
 in the soil, a little below the farm-house, and that whenever 
 the meadows below this hole were inundated by water from 
 the Furler the volume of the spring supplying Lausen be- 
 came rapidly augmented. 
 
 The Furler was in direct communication with the closets 
 and dung-heaps of the affected house. The intestinal evacu- 
 ations from the inmates were thrown into it, and their soiled 
 clothing was washed in it, and it was with the waters of this 
 brook that the meadows had been inundated from the middle 
 to the end of July. The epidemic began at Lausen about 
 three weeks after this inundation. To fix further the connec- 
 tion between the polluted water of the Fiirler and the spring 
 at Lausen, Dr. Hagler, who investigated the case, made an 
 experiment which demonstrated that the epidemic in Lausen 
 was the outcome of the use of water polluted by the dejecta 
 from the patients in the Fiirlerthal, on the other side of the 
 mountain ridge. The hole near the farm-house in the Fiir- 
 lerthal was opened, and the brook led into it ; after three 
 hours the volume of water given out by the spring at 
 Lausen was doubled ; about i8 hundred-weight of common 
 salt was now poured into the hole, and in a very short time 
 the water at Lausen gave the characteristic chemical reaction 
 of this salt, the amount of which gradually increased until 
 
TYPHOID FEVER. ■ 73 
 
 analysis showed the amount of salt present to be about 
 threefold of what it was at the beginning. 
 
 The experiment cleared away all doubt as to the means by 
 which the disease reached Lausen, and the channel through 
 which it was disseminated. 
 
 The Wittemburg Epidemic. — Still another example of the 
 dissemination of typhoid fever through drinking water, which 
 is of interest not only for this alone, but is especially instruct- 
 ive as an illustration that this disease can arise only from the 
 use of waters that are contaminated with the specific causa- 
 tive age?it of typhoid fever, and that the use of water not so 
 contaminated, but equally foul in so far as other pollutions 
 are concerned, does not result in the appearance of this 
 disease. 
 
 The case in point is recorded by Gaff ky ^ and is as follows : 
 
 In June, 1882, there appeared among the privates of the 
 3rd Brandenburg Infantry regiment located at Wittemburg, 
 an epidemic of typhoid fever which, by virtue of its sudden 
 appearance and dissemination (Chart 9) and its limitation to 
 one battalion of this regiment, offered a favorable prospect for 
 the discovery of the causes underlying its existence. 
 
 The three companies of this battalion, in which the disease 
 broke out, numbered 386 men, 226 of whom were quartered 
 in the arsenal, while the remaining 160 were quartered in 
 private houses in the town. 
 
 Of the 160 men quartered in 17 private houses in the 
 town, 24 suffered from typhoid fever, while not a single case 
 occurred among the other inmates of these houses. Indeed, 
 during the course of the epidemic not a single case was 
 reported among the citizens of the town. From this it 
 seemed probable that the cases of typhoid fever that had 
 occurred among the soldiers quartered both in the barracks 
 and in the town had been infected from the same source. 
 After careful inspection of all other possible channels through 
 which the men could have become infected, the water-supply 
 was finally subjected to investigation. 
 
 ^ Gaffky : Mittheilungen aus dem Kais. Gesundheitsanite, 1884, Bd. ii., 
 S. 410. 
 
74 
 
 HVGIEXE OF TRANSMISSIBLE DISEASES. 
 
 
 0} 
 Qt) 
 QD 
 H 
 
 M 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 
 :; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 CJ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■i 
 
 
 -- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 k^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -vl 
 
 'O 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■Jm 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■1 
 
 c~ 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ~ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 hLb 
 
 V 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 immk 
 
 ^ 
 
 
 § 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■!■ 
 
 
 1? 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 •<; 
 
 % 
 
 
 — 
 
 
 
 
 
 
 
 
 
 — 
 
 — 
 
 
 
 
 — 
 
 
 — 
 
 — 
 
 
 
 — 
 
 — 
 
 
 ^" 
 
 ^ 
 o 
 
 
 
 — 
 
 
 
 
 
 
 
 — 
 
 — 
 
 — 
 
 — 
 
 
 
 
 
 
 — 
 
 — 
 
 
 
 — 
 
 — 
 
 
 . 
 
 ^ 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^™ 
 
 55 
 
 1" 
 
 
 — 
 
 
 
 
 
 
 
 — 
 
 — 
 
 - 
 
 — 
 
 
 — 
 
 - 
 
 
 ii 
 
 5 
 
 
 
 ^ 
 
 " 
 
 
 Ui5 
 
 
 1" 
 
 
 — 
 
 
 
 
 — 
 
 
 
 - 
 
 I 
 
 I 
 
 z 
 
 
 
 z 
 
 I 
 
 - 
 
 i 
 
 
 
 i 
 
 i 
 
 
 ^ 
 
 ^ 
 
 — 
 
 
 — 
 
 
 
 
 
 
 — 
 
 
 
 — 
 
 — 
 
 — 
 
 
 
 — 
 
 
 — 
 
 — 
 
 
 — 
 
 — 
 
 f 
 
 — 
 
 ^ 
 
 ii 
 
 ^ 
 
 2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 M 
 
 .p. 
 
 C; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■■ 
 
 ■■ 
 
 's!) 
 
 ft 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 1 
 
 ;; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■■ 
 
 ■■ 
 
 ON 
 
 :; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■i 
 
 's 
 
 i; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 u 
 
 :; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 
 5 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 •' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 U in 
 \ "^ I 
 
 01 
 
 CO 
 CM 
 
 
 ?j 
 
 o 
 
 2 
 
 m 
 
 N 
 
 2 
 
 m 
 
 5 
 
 to 
 
 N 
 
 - 
 
 o 
 
 0) 
 
 CO 
 
 t~ 
 
 o 
 
 lO 
 
 •f 
 
 to 
 
 « 
 
 - 
 
 O 
 
 
 Z 
 
 
 _ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Jj 
 
 
 
TYPHOID FEVER. 75 
 
 The water used by the troops was supplied by two wells, 
 one situated in the yard of the barracks near a privy, the 
 other just outside the barracks yard in the neighboring 
 Burgomeisterstrasse. Upon chemical analysis and careful 
 inspection, both wells revealed considerable contamination, 
 though because of the more agreeable taste of the water in 
 the well outside the barracks yard, in a neighboring street, 
 this was more commonly used for drinking purposes by both 
 soldiers and citizens than was the water of the well within the 
 barracks yard. 
 
 Investigation showed that some time prior to the outbreak, 
 typhoid dejecta had been thrown into the barracks privy, 
 which is situated about 50 feet north of the well in the yard, 
 and upon examining the walls of this privy, which were 
 cemented and had hitherto been supposed to be proof against 
 breakage, two cracks of appreciable size were found, through 
 which the contents had leaked. 
 
 The strata between this privy and the well were for the 
 most part of coarse sand and gravel, and it is therefore 
 probable that the contents of the privy had oozed through 
 the loose soil into the well. This was facilitated probably by 
 three factors : 
 
 (i) The lowness of the water in the well ; (2) the increased 
 amount of water which was drawn from the well at that 
 season of the year, amounting practically to an aspiration 
 upon the water in the surrounding soil ; (3) the direction of 
 the current of ground water, which was found to be from the 
 privy toward the well. 
 
 In Fig. 3 will be seen the relation between the privy and 
 the barracks well, while in Fig. 4 Avill be seen the relation 
 between the barracks and the houses of the town, particularly 
 those houses in which soldiers affected with typhoid fever 
 lodged, and those houses in which cases of the disease had 
 existed in 1881, the year preceding. From the general con- 
 ditions it was evident that suspicion pointed more strongly to 
 the water of the well in the yard of the barracks than to that 
 of the well in the neighboring Burgomeisterstrasse, for the 
 latter, though evidently polluted, was less likely to be specif- 
 
76 
 
 HYGIENE OF TRAXSMISSIBLE DISEASES. 
 
 Fig. 3. — -Plan of barracks at Wittemburg, showing the relation between buildings 
 
 and well. 
 
TYPHOID FEVER. 
 
 77 
 
78 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 ically polluted, for, as stated, there were no cases of typhoid 
 fever among the citizens using water from this well ; and as 
 it was more agreeable in taste than the water from the bar- 
 racks well it was customaiy for the officers, among whom 
 likewise no cases of typhoid fever occurred, to use this water, 
 though in general it is very probable that the officers drank 
 much less water than did the privates. 
 
 The water from the well in the yard of the barracks, 
 though of a very poor character, was nevertheless occasion- 
 ally used for drinking purposes by the men. 
 
 It was akvays used for washing dishes, clothing, and par- 
 ticularly for rinsing beer-mugs and canteens, none of which 
 are ever dried after washing, but only allowed to drain. 
 
 Though subjected to a most careful bacteriological analysis 
 by Gaffky himself, no typhoid bacilli were detected, a result 
 that might have been expected a priori, for by the time the 
 analyses were made (at about the end of the epidemic) the 
 organisms which had been present at the time of the pollu- 
 tion, through which the battalion became infected, had dis- 
 appeared. The pollution was not continuous, and in all prob- 
 ability had lasted for but a few days, when it did occur. 
 
 This negative evidence, however, by no means weakens the 
 ground taken by Gaffky in believing this well to have been 
 the source of infection. 
 
 The Epidemic at Plymouth, Pa., in 1885. — In the spring 
 of 1885 the mining town of Plymouth, Pa., of about 8000 to 
 9000 inhabitants, was visited by an outbreak of typhoid fever 
 of explosive violence. The sudden appearance of the epi- 
 demic, its rapid spread, and the ultimate demonstration of the 
 underlying cause, make it one of the most instructive of the 
 many cases of this kind that have been recorded. From 60 
 to 100 new cases occurred daily, and on one particular day 
 200 fresh cases were reported. At least looo of the 9000 
 inhabitants were stricken down with the disease. 
 
 The circumstances surrounding this outbreak were of such 
 a character as to point directly to the drinking water as the 
 channel of infection. 
 
 The facts tliat were elicited upon inspection of the town 
 
TYP/IOW FEVER. 
 
 79 
 
 Fig. 5. — Chart of Plymouth, Pa., showing sources of its water, and the dis- 
 tribution of the polluted supply (line in red). 
 
TYPHOID FEVER. 8 1 
 
 and its surroundings were as follows : Conspicuous among 
 the data recorded was the fact that while the disease was gen- 
 erally distributed through the town, it occurred, practically, 
 only in those houses that received tJieir water-supply from one 
 special source — /. e. the general water-supply of the town that 
 is obtained from a series of reservoirs situated along the 
 course of a rapidly-flowing mountain stream that skirts the 
 southwest margin of the borough. From these reservoirs it 
 is distributed in pipes in the usual way. It was also noticed 
 that in those houses receiving their water from other supplies 
 or those having private wells, either no cases of the disease 
 occurred or where they did occur it was only among the 
 members of the family who drank of the general supply 
 while away from their homes, during the business hours of 
 the day. During the course of the epidemic it was not 
 uncommon for the disease to appear in almost every house 
 on one side of a street supplied with water from the reser- 
 voirs, while in those on the opposite side having private wells 
 not a case appeared. 
 
 In short, the disease appeared only in those persons who 
 drank of the hydrant water from the reservoirs along the 
 course of the stream mentioned. 
 
 Upon further investigation it was discovered that between 
 the third and fourth reservoirs and about forty feet from the 
 banks of the stream (Fig. 5) was located a solitary house in 
 which there had been, some weeks prior to the outbreak, a 
 case of typhoid fever. The facts that were elicited were 
 these : One of the occupants of this house, a man, had visited 
 Philadelphia on December 25, 1884, and while there had con- 
 tracted the disease. He returned to his home in Januaiy 
 and was ill with typhoid fever for many weeks. During the 
 course of his illness, according to the statements of the 
 nurses and attendants, the dejecta that were passed during 
 the night were thrown upon the snow within a few feet of the 
 stream supplying the town with drinking water, while the 
 daily evacuations were emptied into a privy the contents of 
 which lay upon the surface of the ground. From March 21 
 to March 23 the temperature of the atmosphere became suf- 
 
82 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 ficiently elevated to melt the snow that up to this time had 
 been frozen hard, and during the early days of April there 
 were frequent warm showers. In consequence of these 
 atmospheric conditions the entire mass of dejecta that had 
 been passed by the patient during the course of his illness 
 was washed directly into the stream supplying the reservoirs 
 from which the town obtained the largest part of its water. 
 
 The amount of pollution was therefore exceptionally great, 
 and the disease-producing elements must have been dissem- 
 inated by means of the water very shortly afterward ; at all 
 events, the evidence that was obtained shows that the first 
 cases of the epidemic appeared within from two to three 
 weeks — the period of incubation of typhoid fever — after the 
 polluted water had been distributed through the town. 
 
 The accompanying is a chart of Plymouth, with sources 
 of its water, and the distribution of the polluted supply 
 marked — — (page 79). 
 
 The Outbreak in Philadelphia During the Winter of 
 1897-98. — The city of Philadelphia receives its water-supply 
 in large part direct from the Schuylkill river, a more or less 
 grossly-polluted stream that traverses a thickly-populated 
 .section of Pennsylvania, and finally unites with the Delaware 
 river to the south of the city. 
 
 During December, 1897, January, and a part of February, 
 1898, the weekly returns of the Health Officer of the city 
 revealed the fact that typhoid fever had suddenly appeared 
 in Philadelphia to such an extent as to be fairly regarded as 
 epidemic ; the number of cases reported between November 
 27, 1897, and March i, 1898, having been 1927 as compared 
 with 628 cases for the same period of 1896-97 and as against 
 a weekly average of 40 cases for the eight weeks preceding 
 December, 1897. In short, during the period- of greatest 
 prevalence the number of cases reported weekly was some- 
 what over three times as great as under usual conditions. 
 
 Upon locating these cases the increase was found to be 
 general throughout the city, but the niajorit)' of the cases 
 (about 65 per cent.) (occurred within a siiarply-circumscribed 
 area in the northern .section of thie city that embraces princi- 
 
TYPHOID FEVER. 
 
 Map of Philadelphia, with ward boundaries. 
 
84 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 pally the 15th, 20th, 28th, 29th, 32nd, 27th, and 38th wards 
 (see shaded area on Map, page 83), having a population 
 rouglil)- representing only about one-fifth of the entire popu- 
 lation (census 1890). 
 
 As soon as this state of affairs became evident a careful 
 inspection, including chemical and bacteriological analysis of 
 the milk and water-supplies of this section especially, was or- 
 dered by the Board of Health. The results of careful studies 
 upon the problem by laboratory methods shed no important 
 light upon the origin and mode of dissemination of the disease. 
 
 It was clear to those engaged upon the investigation ^ that 
 the cause of the outbreak must have been operative at some 
 period antecedent to the epidemic outbreak of the disease ; 
 that infection of a large number of persons must have 
 occurred simultaneously and probably through the same 
 channel ; and that, taking four to six days as the time neces- 
 sary to recognize the disease and notify the Board of Health, 
 and seven to ten days as the period of incubation of typhoid 
 fever, infection must have occurred during the week ending 
 November 20, 1897. 
 
 On referring to the events of this week it was found that 
 on the afternoon of November 16 there was suddenly de- 
 posited into the Schuylkill river, as a result of the overflow of 
 the large intercepting sewer that carries the sewage of a great 
 portion of northern Philadelphia, a large volume of raw 
 sewage. The point at which this occurred was located on 
 the same side of the river and but a short distance up stream 
 (a few hundred feet) from the intake of the pumping station 
 that supplies water to the Queen Lane Reservoir. At the 
 time of the accident and for about two hours afterward, the 
 pumps were engaged in filling this reservoir, and a very large 
 portion of the grossly-polluted water must have been pumped 
 directly into it. The pumps at the stations located further 
 down the stream were stopped a few hours after the accident 
 " because the water was discovered to have a peculiarly bad 
 
 ^ In this conneclion I wish to credit Dr. II. \\. Pease, at the time assistant 
 in the Municipal Laboratory, with all that is due him for valuable services 
 rendered. 
 
'rvrJlOID FEVER. 
 
 85 
 
 Chart 10. — Sho-wing incidence of typhoid fever in Philadelphia. 
 Black bars, for the entire city ; red bars, for wards in Queeii Lane 
 district. 
 
 
 CM 05 S 
 
 = 03 CO 
 ^ tN Cr) CO w 
 
 r^ 
 
 Csj Csj -^ 
 
 - 
 
 2 
 
 m 10 CM ^ 
 CM^coT~,CMcor^2 
 
 01 CO ^ "^ S 'o 
 
 cylci 
 Cvj CO 
 
 C 
 
 ^ a 5 
 
 5 5 Q 
 
 Q 
 
 Q 
 
 Q-5-?-?-5-§'"u; 
 
 
 a a 
 
 50 
 40 
 30 
 20 
 10 
 300 
 90 
 SO 
 70 
 60 
 50 
 40 
 30 
 20 
 
 10 
 100 
 
 90 
 80 
 70 
 60 
 50 
 40 
 30 
 20 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ?^ 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 .cT 
 
 
 
 
 
 
 
 
 CO 
 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 c 
 
 
 
 
 
 
 
 
 !- 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 
 
 
 vx. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 '^ 
 
 
 
 
 
 
 
 
 u 
 
 
 
 
 
 
 
 
 ■::j 
 
 
 
 [_ ll 
 
 
 
 
 
 ■^ 
 
 
 
 
 
 
 
 
 -3 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 111- 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 J.:4 
 
 F 
 
 ii 
 
 L 1 1 
 
 
 
 jIjI 
 
 1 
 
 
 
 1 1 
 
 II 11 1 j 1 iiiiii 
 
86 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 taste," so that all the reservoirs below the point of pollution 
 were more or less contaminated, though that at Queen Lane, 
 because of the proximity of its intake, was, as subsequent 
 events demonstrated, most affected. 
 
 Upon inquiry as to the distribution of the water from the 
 Queen Lane Reservoir, it was ascertained, through the cour- 
 tesy of Mr. J. C. Trautwine, Jr., Chief of the Bureau of 
 Water, that the area supplied with water from this reservoir 
 was embraced within the limits of the wards in which the 
 largest proportion of cases of typhoid fever occurred. 
 
 The connection, therefore, between the typhoid cases in 
 these wards and the character of water supplied to them 
 was, in the judgment of those engaged in the investigation, 
 reasonably established ; even though repeated bacteriological 
 examination of the water had failed to demonstrate the pres- 
 ence of typhoid bacilli in it. 
 
 It is not necessary to discuss here the increase of typhoid 
 fever in other sections of the city ; it suffices to say that cir- 
 cumstantial evidence connects it also with the polluted water- 
 supply. By reference to Chart lo the progressive incidence 
 of the cases, and the relation between those in the most 
 affected district and those in the city generally, will be seen 
 graphically represented.^ 
 
 Chart lo shows the typhoid morbidity in Philadelphia in 
 the winter of 1897-98. The period represented embraces 
 two months prior to the discharge of raw sewage into the 
 river, and three months after the epidemic had reached its 
 maximum. (Compiled from official reports of the Health 
 Officer.) Black bars represent the number of cases weekly 
 for the entire city. Red bars represent the number of cases 
 occurring at the same time in the district supplied by the 
 Queen Lane Reservoir into which the greatest amount of 
 sewage was pumped. The population of this district was 
 about one-fifth of the entire city. 
 
 To emphasize further the important relation between the 
 
 * For details, see Annual Report of Ihc Department of Public Safety of 
 Philadelphia, 1898; section referring to the Division of Bacteriology, etc., 
 of the Hureau of IIe;iUh. 
 
TYPHOID FEVER. 
 
 87 
 
 Chart ii. — Showing death-rates fj-oni typhoid fevet' iii iSg^f. in 66 
 cities. Grouped according to the quality of their drinkitig water. 
 
 jo 10 20 30 40 50 60 70 80 90 100 
 
 
 1 
 
 
 
 P-L 
 
 re 
 
 _M^,,UtJ;^_ 
 
 Sd-'-^— ' 
 
 
 
 
 
 
 Munich 
 Vienna 
 
 
 
 
 
 
 
 wu 
 
 1 HJ 
 
 M 1 
 
 op 
 
 1 II 
 
 ^^ 
 
 
 
 
 
 
 4. (J ,- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Hague 
 Berlin 
 Rotterdam 
 Breslau 
 Hamburg 
 ; Zurich 
 Amsterdam 
 London 
 Edinburgh 
 Warsaw 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Li 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Pr- 
 
 priu F:i*"' 
 
 
 -W 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 "H 
 
 eriy 
 
 
 
 
 
 
 O.J -^ 
 
 
 B 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 Frankfort 
 Copenhagen 
 Dresden 
 ~_ Brussels 
 Venice 
 Dayton 
 Paris 
 
 
 
 
 Hi- 
 
 „ 
 
 , ,1 
 
 
 . _ 
 
 
 1 , 
 
 
 c. 
 
 ■ 
 
 
 \A/ 
 
 . II 
 
 
 
 
 
 
 bru^,.u,-vva.^,^, 
 
 L^'^.^-Vt^'i'''^^"- 
 
 
 
 
 
 
 
 D 
 
 rlvpn !\A/^llo r^ 
 
 ,1.1 1.1 
 
 
 
 "1-^7 - 
 
 
 
 
 
 II <-iio, y^j 
 
 
 
 
 
 1 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 1 
 
 
 
 ^■^■H 
 
 
 
 
 1 
 
 
 
 
 
 
 
 1 
 
 
 «■!■ 
 
 1 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (■ 
 
 Brooklyn 
 New York 
 Manchester 
 Boston 
 NewHa«en 
 '_ Glasgow 
 Cambridge 
 Sydney 
 Worcester 
 
 HHB 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H>BB 
 
 
 3u 
 
 rfa 
 
 
 
 
 ;+u 
 
 1 
 
 
 .. 1.., 
 
 
 -j;„ 
 
 _, 
 
 
 BBS != 
 
 
 1 1 
 
 Lcg^ MMpV^UM^,.^ 
 
 
 bS 
 
 Pocoi- 
 
 voirsf-Wat 
 
 
 
 23.1 ^ 
 
 
 ■ 
 
 
 \\^o^i 
 
 
 U L 
 
 01- 
 
 ^^u 
 
 
 
 HB 
 
 1 
 
 
 airlst- 
 
 PoMiltic 
 
 
 
 
 
 
 
 
 
 l^£ 
 
 
 
 
 
 
 
 1 
 
 
 
 1 
 
 1 1 
 
 
 
 
 
 WI^P^ 1 Kl 
 
 
 ,-,1 
 
 -R 
 
 versr 
 
 or 
 
 d;' '^ 'L 
 
 ,l.-.l 
 
 
 f 
 
 Montreal 
 Quebec 
 Trenton 
 Omaha 
 Toledo 
 New Orleans 
 ~ St. Louis 
 Paterson 
 Minneapolis 
 
 
 1 rr'-|"' 
 
 
 1 
 
 
 
 ■ D^i ,,*: 
 
 
 -may- 
 
 Wq 
 
 „ 1 J:jL J_i i 1. 
 
 
 ■■iS Mr'i-"|"-|"" 
 
 
 
 IBSBBBHv'3.n i sh e d 
 
 ,. 1 
 
 „J J_ 1 i_J.. ir V: 1 „ 
 
 283 - 
 
 
 
 BBB iBHi^ll~ ~ 1^ > ' uti riTSe d im e n tati n—etc 
 
 
 
 . 
 
 
 ■■n mmmmm 
 
 
 
 
 
 
 
 
 t 
 
 
 
 1^ 
 
 
 
 
 
 
 
 
 
 Hamilton 
 Toronto 
 
 ] Milwaukee 
 
 " Detroit 
 Cleveland 
 Chicago 
 Buffalo 
 
 
 
 
 1 1 
 
 _ 1 _i 
 
 
 e-onles 
 
 
 
 
 
 SBB Bi= 
 
 
 b 
 
 
 
 
 Ebb B 
 
 1 
 
 
 
 
 ,,ul:_i^J_ b_- 
 
 lutio 
 
 
 
 
 
 "30.3 \ 
 
 1 
 
 
 - 
 
 
 jeyi LU ru 
 
 
 
 
 
 
 l^l^HH HI^BI 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tri 
 
 plane 
 
 
 usei 9 
 
 
 
 
 
 j 
 
 
 
 Tearr 
 
 S-; 
 
 ,nc 
 
 -S 
 
 mall-Lra 
 
 1 
 
 <ej 
 
 
 Rome 
 Denver 
 
 San Francisco 
 Wilmington 
 Syracuse 
 \ Reading 
 Providence 
 Hartford 
 Philadelphia 
 Atlanta 
 
 IBBBBBBBBU'^'^^' 
 BBBBBBBBBBrim 
 
 -Lrimited-Watersh'eds- 
 
 1 1 ,1 J 1 1 LJ J 
 ore-or-H ess -In habited: — 
 
 -4270-4- 
 
 bbBS^m^^«'^"'^''P'^'?^^''N^^^)^^"H"^°p"'°"s 
 
 
 
 
 )wri-to[be-Pol|uted-vfith 
 Sewae^ and othef 
 
 JnfectipusJMatter 
 
 — ^where fibstracted — 
 
 — 
 
 -60t8-^- 
 
 Grand Rapids 
 
 Cincinnati 
 ] Albany 
 
 Troy 
 
 Jersey City 
 ; Pittsburgh 
 
 Lowell 
 
 Camden 
 
 Louisville 
 
 Washington 
 
 Alexandria 
 
 Cairo 
 
 
 — — ^for-user 
 
 
 — 
 
 — 
 
 
 [mmmBB— ^^^^^— ^p 
 
 
 
 
 
 
 
 
 
 
 
 
 [^■■fciMM^M^I^M^HS^" 
 
 
 
 
 
 
 B 
 
 Reproduced with the permission of the author and of the Association of 
 Civil Engineers of Cornell University. 
 
8S 
 
 JIYGJEXE OF TKAXSMISSIBLE DISEASES. 
 
 •■^ 
 
 v> 
 
 ^ 
 
 ■= 
 
 ■S^ 
 
 :- 
 
 •<^ 
 
 ^ 
 
 V 
 
 ■<i 
 
 C) 
 
 >^ 
 
 'O 
 
 
 
 <i 
 
 8 
 
 ;^ 
 
 s 
 
 
 
 ^ 
 
 < 
 
 
 
 8° oooooo 
 ,-c"a3t^ioin^co 
 
 N 2 
 
 
 ooa 
 
 
 
 
 
 
 
 
 
 i 
 1 
 1 . 
 
 
 GGSI 
 
 
 
 
 
 
 
 
 
 icn 
 
 |C3 
 < 
 
 
 SGST 
 
 
 
 
 
 
 
 
 
 "aver 
 
 ■ 
 
 10 
 
 IG8Z 
 
 
 
 
 
 
 
 
 
 1 ^_ 
 1 
 
 t^ 
 
 9GST 
 
 
 
 
 
 
 
 
 
 !■ 
 
 1 
 
 10 
 
 9G8I 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 tGST 
 
 
 
 
 
 
 
 
 
 Ik 
 1 
 
 - 
 
 SGSI 
 
 
 
 
 (g£ 
 
 BtAV 
 
 ■^H 
 
 ^SIN^ 
 
 MM 
 
 ^^ 
 
 CO 
 
 ^GST 
 
 
 
 
 
 
 
 
 1 
 
 1 
 
 CO 
 
 
 
 1 
 
 TGST 
 
 
 
 
 
 
 
 
 1 
 1 
 
 ^^^^^^ 
 
 
 OGSl 
 
 
 
 
 
 
 
 1 
 
 li 
 
 ^^^ 
 
 1 
 
 <N 
 
 GS8T 
 
 
 
 
 
 
 
 
 1 
 
 CO 
 
 §^■1 
 
 im^mi^H 
 
 
 1 
 
 88ST 
 
 
 
 
 
 
 
 |l 
 
 1 
 
 
 ■ 
 
 ■■■■ 
 
 H^HHi ^^1 
 
 
 
 
 u 
 
 1 
 
 18ST 
 
 
 
 ^_ 
 
 i 1 
 
 
 ^^ 
 
 ^^^^^H 
 
 CO 
 CO 
 
 ^^ 
 
 
 — 
 
 ^^ 
 
 ^^ 
 
 ^^^^"^K 
 
 988T 
 
 
 
 
 1 
 
 ^^ 
 
 
 ^J__ 
 
 ^^^^^H 
 
 h- 
 
 1 
 
 
 
 
 ^^" 
 
 ^^^^^^^^B 
 
 988T 
 
 
 
 
 
 
 
 1 
 
 
 1 
 
 ^f 
 
 ■■ 
 
 HBI^IIH 
 
 
 
 1 
 
 t88T 
 
 
 
 
 
 
 
 
 0> 
 
 
 1 
 
 (0 
 
 §■ 
 
 ^^■B 
 
 
 1 
 
 SS8T 
 
 
 
 
 
 
 
 
 Mi 
 C3 
 < 
 
 
 1 
 
 lO 
 
 C^i 
 
 ^ 
 
 ^■B 
 
 
 
 Z88T 
 
 
 
 
 
 
 
 
 LI 
 > . 
 
 < 
 
 ^ 
 
 ^^^^ 
 
 CI 
 
 188T 
 
 
 
 
 
 
 
 
 
 ^^^^^M 
 
 o 
 CO 
 
 1 
 
 
 
 
 
 
 
 
 
 
 1 1 
 
 <N 
 
 0881 
 
 IHHIHHH 
 
 
 
 ! 
 
 ^^^^^^^^ 
 
 
 o o o o c 
 
 O 0) (D r^ It 
 
 c o o c 
 in "t CO c 
 
 5 O 
 
 
ASIATIC CHOLERA. 89 
 
 health of communities, particularly as regards typhoid fever, 
 and the character of water supplied to them, the accompany- 
 ing chart (Chart 11) is taken from the instructive studies of 
 Mr. James H. Fuertes. The figures at the right hand side 
 represent the averages of the annual mortalities in each group 
 of cities. There is no further comment needed. 
 
 Chart 12 illustrates the influence of artificial methods of 
 purification of a polluted water-supply upon the health of the 
 community using it. For the twelve years prior to the appli- 
 cation of filtration to the water-supply of Hamburg, Ger- 
 many, the average annual death-rate from typhoid fever was 
 39.7 per 100,000 of population ; for the six years since 
 filtration was established the average death-rate from the 
 disease has been 9 per 100,000; and for the year 1898 it 
 was 5 per 100,000. In less than one year after the water- 
 supply of Hamburg was filtered, this city stepped from a 
 place in the lowest to one in the second group of Mr. 
 Fuertes' classification.^ 
 
 ASIATIC CHOLERA. 
 
 Cause. — The disease results from the invasion of the body 
 by the micro-organism discovered by Koch and known as 
 spirilliuii cliolercB Asiaticce. 
 
 The spirillum, or " comma bacillus," of Asiatic cholera is, 
 as its name implies, a curved or spiral organism, occurring 
 most frequently as short, comma-shaped rods. It is motile, 
 non-spore -forming, liquefies gelatin, produces indol, and 
 does not cause fermentation of glucose or lactose. At times 
 it coagulates milk, while again it does not. It is destroyed by 
 an exposure of five minutes to 65° C. It is not destroyed by 
 freezing. According to different authorities it is destroyed by 
 drying in from three to four hours. When in a moist condi- 
 
 ^ I wish to express my obligation to Mr. F. Andreas Meyer, Chief Engineer 
 of the city of Hamburg, for his courtesy in supplying me with the data from 
 which Chart 12 was compiled. 
 
90 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 tion it retains its vitality often for months, though it is prob- 
 able that it becomes weakened in virulence after this time. 
 
 Its morphological and cultural peculiarities are not suf- 
 ficient to lead to its absolute identification by these means 
 alone, as there is a group of other special organisms that are 
 in many of these respects almost identical with it. During 
 
 Fig. 6. — Spirillum of Asiatic Cholera : /, stained by ordinary method : //, stained 
 to show flagella. 
 
 the prevalence of Asiatic cholera — i. e. when the disease is 
 epidemic — the finding of spiral or comma-shaped organisms 
 on microscopical examination of the intestinal discharges of 
 people with diarrhea is sufficient to justify the opinion that 
 the case is suspicious and should be considered as cholera 
 until decided to be otherwise. 
 
 The most important diagnostic tests for this organism are 
 its failure to infect pigeons when a small portion of a solid 
 culture of it is introduced into the pectoral muscle, and the 
 test with the serum of animals immunized against cholera, as 
 devi-sed by Pfeiffer. In this latter procedure genuine cholera 
 spirilla when brought in contact with the serum of animals 
 highly immunized (artificially) from Asiatic cholera lose their 
 motility, and gradually accumulate together in small masses. 
 (The reaction is analogous to that known as Widal's reaction 
 for typhoid fever.) Spiral organisms that are not etiologi- 
 
ASIATIC CHOLERA. 9 1 
 
 cally related to cholera when subjected to this test experience 
 no change in their normal behavior/ 
 
 After neutralizing the acid reaction of the gastric juice and 
 arresting intestinal peristalsis with opium, Koch succeeded in 
 producing in guinea-pigs to which large doses of cultures of 
 this organism were given per os a condition of the intestinal 
 canal that was pathologically analogous to that seen in cholera 
 in man. 
 
 By the ordinary methods of inoculation no effect is pro- 
 duced, as a rule. By injection into the peritoneal cavity of 
 guinea-pigs the result is either that suggestive of depression 
 due to acute intoxication, when small doses are employed, or, 
 when large doses are used, these symptoms may be followed 
 by death with peritonitis and evidences of general infection, 
 though the latter is not usually conspicuous. 
 
 Geographical Distribution, Season, Race, etc. — 
 The disease is endemic in India, where it has been known for 
 centuries. Epidemics have occurred in practically all coun- 
 tries, in each instance their origin being readily traceable 
 either directly or indirectly to the delta of the Ganges, the 
 home of the disease. Between its first appearance in this 
 country in 1832 and its last in 1873 there have been eight 
 outbreaks of varying degrees of severity, those of 1832, 
 1853-54, and 1873 being the most severe. In all instances 
 the origins of these epidemics were directly traceable to 
 imported cases of the disease. Since 1873, though the dis- 
 ease has frequently appeared elsewhere, there have been no 
 outbreaks of cholera in the United States. 
 
 Epidemics of the disease are much more apt to occur in 
 the warm than the cold months, and have been known to 
 disappear with the advent of cold weather, though this is not 
 always the case. It is more frequent in places of low than in 
 those of high altitude. 
 
 According to Hirsch, the negro is more susceptible to the 
 disease than others of the human race, while the Chinese have 
 often shown a relative insusceptibility to it. 
 
 ^ Pfeiffer : Zeitschrift filr Hygiene tind Infektionskrankheiteii, Bd. xviii., 
 S. I ; ibid., Bd. XX., S. 198. 
 
92 HYCIEXE OF TRANSMISSIBLE DISEASES. 
 
 Mode of Dissemination. — Cholera is one of the non- 
 co)itacrious, infectious diseases. It is not disseminated through 
 the air. The specific causative element is contained in the 
 e\-acuations from the bowels of cholera patients, and prob- 
 ably only in the evacuations, though it is sometimes said to 
 be present in the vomited matters. 
 
 The disease is disseminated principally through the water 
 and through food that has become contaminated with the 
 evacuations of cholera patients. 
 
 With regard to the epidemic occurrence of cholera, modern 
 opinion is at one in regarding specifically polluted water as 
 one of the most important factors in its dissemination. In 
 the voluminous literature on the subject numerous instances 
 are recorded in which not only was all doubt as to the part 
 played by water in spreading the disease removed by circum- 
 stantial evidence, but in a number of cases the actual, specific, 
 etiological factor in the malady was discovered by bacteriolog- 
 ical methods. No more striking and instructive illustration in 
 this connection could be cited than the cholera epidemic of 
 Hamburg and Altona, in Germany, in the autumn and winter 
 of 1892 and 1893. These two cities merge into one another 
 without any definite line of demarcation. They are under 
 distinct forms of government. Hamburg, being one of the 
 old free cities, retains special privileges, while Altona is under 
 the Prussian government. The population of Hamburg is 
 about 640,400, while that of Altona is about 148,615. Both 
 cities take their water-supply from the river Elbe. At the time 
 of the epidemic, Hamburg distributed this water to the citizens 
 just as it was pumped from the river, while Altona passed it 
 through sand filters before allowing it to enter the city mains. 
 The number of cases of cholera in Hamburg during the epi- 
 demic was 16,957 with 8606 deaths, while in Altona the cases 
 from the same disease, during the same time, numbered only 
 516 with 316 deaths: in other words, the number of cases 
 of this disease in the city receiving Jtnfiltcrcd water was 
 about 264.8 to every 10,000 of the population, while in the 
 city receiving filtered water there were about 34.6 cases to 
 every 1 0,000 of pf)pulation ; and of tliis number, it must be 
 
ASIA riC CHOLERA. 
 
 93 
 
 CHOLERA 
 
 Fig. 7. — The black dots show the location and number of the cholera cases in 
 both Hamburg (to the right of the broken dividing line) and Altona (to the left 
 of that line). 
 
94 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 remembered, many drank the water of Hamburg during the 
 time of their occupation in that city, for Hamburg affords 
 employment for many residents of AUona. Since this epi- 
 demic of 1892 one has no difficulty in determining the 
 boundary line between Hamburg and Altona. One has but 
 to represent graphically on a map of the two cities the loca- 
 tions of the cholera cases (Fig. 7) when the ramifications of 
 the mains carrying Hamburg's impure water stand out in 
 marked contrast to those of the Altona system carrying 
 filtered water. Since this epidemic Hamburg has instituted 
 a most elaborate and satisfactory system of filtration, and 
 though there has been no opportunity to test this system 
 against cholera, its efficiency has been demonstrated in 
 another way. Prior to the installation of this method of 
 purifying water the death-rate from typhoid fever in Ham- 
 burg was high, ranging from 23 to 34 per 100,000 of popu- 
 lation ; the first year after the filters were put in operation the 
 typhoid mortality dropped to 1 8 and the second year to 6 per 
 100,000 of population (Fuertes). 
 
 The disease may be transmitted by flies and other insects 
 that, having come in contact with the stools of these patients, 
 convey the germs of the disease to foods, such as milk, 
 cooked meats, fruits, etc. Experience has taught that it is 
 carried from places in which it is endemic or epidemic, along 
 the lines of travel and by means of surface water-courses. 
 
 All objects, articles of body- and bed-clothing, etc., that 
 are soiled by the dejecta of cholera patients are capable of 
 conveying the disease. 
 
 The general concomitants of poverty, such as overcrowd- 
 ing, filth, bad food, insufficient clothing and shelter, intem- 
 perance, and exhausting labor, especially favor its dissemina- 
 tion. 
 
 Portals of Infection. — The only natural mode of infec- 
 tion with which we are acquainted is by way of the alimentary 
 tract. It is needless at this place to enumerate the various 
 ways in which this may occur. It will suffice to say that, as in 
 the case of typhoid fever, one must actually swallow the spe- 
 cific micro-or^ranism that has been derived from the bowels of 
 
ASIATIC CHOLERA. 95 
 
 a patient sick of cholera. It is appropriate to state here that 
 in experiments on animals with a view of reproducing the 
 disease through the administration of the specific organism 
 by the mouth, the acidity of the gastric juice, by destroying 
 the organisms, has served as an effectual barrier against their 
 growth and passage into the intestines in a living condition. 
 To what extent similar protection is afforded to healthy 
 human beings it is impossible to indicate, but certainly, in the 
 light of experiment, we may look upon all conditions that 
 tend to neutralize or diminish the acidity of the gastric juice 
 as predisposing to infection. 
 
 Prophylaxis. — In view of the fact that in practically 
 every instance of an outbreak of this disease, in countries in 
 which it is not endemic, its origin has been traced to immi- 
 grants from localities where the disease is present, it is mani- 
 fest that a careful system of quarantine should be established 
 at the earliest moment after conditions become threatening. 
 Such a- system should embrace not only a suspension of the 
 maritime intercourse, but should be uninterruptedly continued 
 along the inland borders as well. 
 
 In addition to this, what has been said for typhoid fever, 
 with regard to the cooking of all foods ; disinfection of all 
 excreta ; disinfection by steam, hot water, or chemical means 
 of all soiled linen, underclothing, and bed-clothing ; destruc- 
 tion of all refuse from meals ; and the scalding of all eating 
 utensils that should be iiscd exclusively by the patient, applies 
 equally to Asiatic cholera. 
 
 In times when the disease threatens, neither water nor 
 milk should be used that has not been previously heated to 
 at least 70° C. for not less than fifteen minutes. All foods 
 and drinks should be carefully protected from the access of 
 flies and other insects, since some of these may have been in 
 contact with the evacuations of cholera patients and thus 
 serve as carriers of the specific agent that causes the disease. 
 
 When the disease prevails, all persons suffering from diar- 
 rhea, no matter how insignificant it may appear, should be 
 regarded as suspicious and should be subjected to the same 
 vigilant supervision as applies to genuine cholera patients ; 
 
96 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 for many of these cases, though mild, are nevertheless chol- 
 era, and are capable of disseminating cholera. Because of 
 their comparatively innocent nature these mild cases often 
 escape the attention that their importance demands ; for the 
 same reason they are more dangerous than the outspoken 
 cases which attract attention from the onset owing to the 
 severity of their course. Unless it be borne in mind that the 
 mild cases, some of them not even confined to the house, are 
 a grave menace to those with whom they are associated, 
 and are treated as such, we can but look to them as fruitful 
 sources for the dissemination of the disease. 
 
 Convalescents from cholera should be kept isolated, and 
 the evacuations from the bowels should be thoroughly disin- 
 fected until bacteriological examination demonstrates that the 
 specific micro-organism causing the disease has disappeared 
 from the evacuations. These individuals should be permitted 
 to mingle with others only after a disinfecting bath, and after 
 having been supplied with clean clothing previously disin- 
 fected by steam or boiling water. 
 
 Care of the Dead. — After death a firm pledget of cotton, 
 soaked in either 5 per cent, carbolic-acid or i : 1000 corrosive- 
 sublimate solution and then wrung out, should be placed in 
 the anus ; the body should be wrapped in a sheet wrung out 
 in either of these solutions, and it should be either buried or 
 cremated. 
 
 The question concerning the disposal of the dead is one 
 upon which some discussion has arisen, and as it is of no small 
 importance, it might be of interest to see what experiment 
 has taught us in this connection. In his experiments upon 
 the destiny of pathogenic bacteria in the dead body, von Es- 
 march was unable to detect later than five days after death 
 living cholera-spirilla in the body of a guinea-pig that had 
 died of the experimental form of the disease ; and as a result 
 of experiments performed in the Imperial Health Bureau at 
 Berlin, it was found that the bodies of guinea-pigs that had 
 died of cholera, induced by Koch's method of inoculation, 
 contained no living cholera-spirilla when exhumed after hav- 
 ing been buried for nineteen days in wooden boxes, or for 
 
AMCEBIC DYSENTERY. 97 
 
 twelve days in zinc boxes. In a few that had been buried 
 in moist earth, without having been encased in boxes, the 
 results of examinations for cholera-spirilla were likewise 
 negative. 
 
 There does not seem, therefore, to be any objection to the 
 burial of the bodies, providing the interment does not take 
 place in a locality where a spring or water-course could be 
 directly contaminated ; indeed, on the contrary, this method 
 of disposing of infected materials generally is second to 
 cremation only in its requiring a longer time for the accom- 
 plishment of the same end. 
 
 AMOEBIC DYSENTERY, 
 
 ( Tropical Dysentery. ) 
 
 Cause. — Because of its constant presence in the anatomi- 
 cal lesions and in the stools of persons suffering from this 
 disease ; and because of the results of inoculation experi- 
 ments performed by Kartulis, amoeba dysenterice (also known 
 as amoeba call) is now generally held to be the cause of the 
 so-called " tropical dysentery." As its name, " amoeba," im- 
 plies, it is a unicellular, contractile, protoplasmic organism 
 (Fig. 8). It has an enveloping ectosarc of clear material and 
 an endosarc of granular protoplasm. It possesses a homo- 
 geneous, refractive nucleus, and usually several vacuoles are 
 to be seen in its protoplasmic body. In size it ranges from 
 0.012 to 0.035 mm. in diameter. Kartulis has succeeded in 
 cultivating it in hay infusions and has produced dysentery in 
 cats by the injection of these cultures into the rectum.^ 
 
 It may be remarked that in examining the stools of dys- 
 enteric patients for amoebae there are certain points which, if 
 observed, will facilitate their detection. The amoebae are not 
 uniformly present in all parts of the stools. They are most 
 
 1 Kartulis: Centralbl. fur Bakteriologie tmd Parasitenkunde, 1891, Bd. ix., 
 
 s 365. 
 
 7 
 
98 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 numerous in the small, grayish-yellow pus collections that 
 are seen to float in the brownish fluid of the stools. They 
 are less frequent in the viscid, blood-stained mucus. They 
 are rare in the large greenish or yellowish-brown shreddy 
 masses of detritus, and when found here may often be 
 motionless (Lafleur). 
 
 Amoebic dysentery is therefore to be considered as an 
 infectious disease, the morbific causative agent of which is of 
 
 Fig. 8. — .Amoeba, dysenteriae (after Councilman and Lafleur). 
 
 the family of protozoa. It is not contagious in the sense in 
 which contagion is ordinarily understood. 
 
 Geographical Distribution. — It occurs both endemic- 
 ally and epidemically everywhere in tropical and subtropical 
 countries, and cases have been encountered in practically 
 all European countries and in many parts of the United 
 States. 
 
 Mode of Dissemination. — The amcebai causing the 
 disease are passed from the bowels of dysenteric patients in 
 larger or smaller numbers, according to the severity of the 
 attack. When abscess of the liver is secondary to the intes- 
 tinal lesions, this may perforate the diaphragm, open into the 
 lung, and the amoeba may then be found in the expectora- 
 tion. 
 
 We have no knowledge of the life-histor)- of this organism 
 
AMCEB/C DYSENTERY. 99 
 
 outside the body, and it is therefore impossible to speak 
 definitely as to the means through which it may be carried 
 from diseased to healthy persons ; but if it possesses the pecu- 
 liarities common to other amoebae it is quite probable that it 
 finds conditions in both the soil, especially marshy soils, and 
 in water that favor its existence and development. It is not 
 unlikely then that water and soil, when polluted with the 
 discharge of dysenteric patients, support the life of the 
 organism and may serve as potent factors in spreading the 
 disease. 
 
 There are grounds for the suspicion that amoebae capable 
 of causing this disease are more or less constantly present in 
 the marsh waters of many tropical places, though they have 
 not been detected by the common methods for isolating such 
 organisms. 
 
 Portals of Infection. — The commonest recognized por- 
 tal of infection is through the mouth — i. e. as a result of the 
 use of water or uncooked foods in or on which the organism 
 is located. The experiments of Kartulis leave no doubt that 
 infection can occur through the rectum, though this is prob- 
 ably a very rare mode in human beings. 
 
 Prophylaxis. — The stools of dysenteric patients should 
 be carefully disinfected before being finally disposed of. 
 
 When the disease prevails, uncooked vegetables should 
 not be eaten, and only water that has been boiled should be 
 drunk. 
 
 What has been said under this head with regard to typhoid 
 fever and Asiatic cholera applies with equal force here. 
 
lOO HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 TUBERCULOSIS, 
 
 Definition and Cause. — Tuberculosis is an infectious 
 disease characterized by the formation of nodular bodies — 
 tubercles — from which it takes its name, and resulting from 
 the presence in the tissues of a specific micro-organism, 
 bacillus tuberculosis, discovered by Koch in 1881-82. 
 
 Opinions are somewhat at variance concerning the trans- 
 missibility of tuberculosis, particularly the pulmonary form ; 
 but the bulk of the evidence favors the opinion that the dis- 
 ease may be, and often has been, contracted through continu- 
 ous respiration of the air of apartments occupied by tuber- 
 culous individuals. Not that the consumptive throws off 
 with the breath, in the course of ordinary respiration, the 
 specific bacillus of the disease, for this is not the case ; but 
 rather that by inattention to the proper prophylactic meas- 
 ures the sputum of such patients, always rich in living tuber- 
 cle bacilli, is expectorated upon the floor, into napkins, or in 
 other undesirable places, becomes dried, ground into dust, 
 and in this form is inhaled by those in attendance upon the 
 patient. When infection or transmission occurs, it is prob- 
 ably to be explained in this manner. 
 
 The bacillus of tuberculosis is a slender, rod-shaped organ- 
 ism usually presenting the appearance of being somewhat 
 beaded. It is believed to form spores, it is motionless, it cannot 
 be readily cultivated on the ordinary nutrient media, though 
 it can be induced to lead a saprophytic form of existence on 
 sterilized blood-serum, on nutrient agar-agar, and in bouillon 
 to which glycerin has been added, and sometimes on potato. 
 It develops under these conditions only at the temperature 
 of the body. It is destroyed by the temperature of boiling 
 water in a few minutes, and by lower temperatures also, but 
 after a longer time — viz., in four hours by 55° C, in fifteen 
 minutes by 65° C, in five minutes by 80° C. It is not de- 
 stroyed by either diying or freezing. In the dry state it is 
 much more resistant to heat than in the moist. It is recog- 
 nized b)- its microchemica! reaction with particular dyes. 
 
TUBERCULOSIS. lOI 
 
 This reaction is characterized by the tenacity with which the 
 tubercle bacillus retains the staining, even when subjected to 
 the action of comparatively strong decolorizing solutions. 
 The same reaction is common to several other organisms — 
 viz., the bacillus of leprosy, bacillus of syphilis, and the 
 
 Fig. 9. — Stained sputum containing bacillus tuberculosis. The delicate beaded 
 rods in the figure are bacillus tuberculosis. 
 
 smegma bacillus. (For details of the method of staining and 
 the differential tests for these organisms, the reader is referred 
 to works on Bacteriology.) 
 Geographical Distribution, Race, Sex, etc. — The 
 
 disease occurs in all countries, among all peoples, and at all 
 ages. It is more frequent in overcrowded than in sparsely- 
 settled localities, and somewhat more common in low than 
 in high altitudes. 
 
 The American Indians and the negro races exhibit a marked 
 susceptibility to the disease, as do also the offspring from the 
 commingling of the white and colored races. It is seen in 
 many of the domestic animals, notably bovines. It is toler- 
 ably common in pigs, rare in sheep, dogs, and cats. Many 
 of the wild animals in which tuberculosis does not occur 
 while they are in the native state develop the disease after 
 confinement. It is of the greatest sanitary importance to 
 note the fact that, amonsf the domestic animals in which the 
 
102 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 disease occurs, bovines, especially milch cows, are most often 
 affected. 
 
 Mode of Dissemination. — As has been already stated, 
 the part played by heredity in disseminating the disease is 
 most conspicuously exhibited in the perpetuation of a par- 
 ticular condition of vitality that renders the individual en- 
 dowed with it peculiarly susceptible to this form of infection. 
 
 The frequency of tuberculosis in the young of tuberculous 
 parents cannot always be referred to the congenital existence 
 of the disease ; in fact, authorities are pretty well at one in 
 the opinion that this is rarely the case. It is more probably 
 due to direct infection from parent to child through their very 
 intimate association. It cannot be denied, however, that 
 intra-uterine tuberculosis of the fetus is occasionally en- 
 countered. 
 
 Every tuberculous individual is a source from which the 
 disease may be further disseminated. This is conspicuously 
 true with regard to those afflicted with the pulmonary mani- 
 festations. As said above, the sputum of consumptives con- 
 tains the specific causative micro-organism — bacilhis tuber- 
 culosis — in enormous numbers. When such sputum is 
 allowed to dry and become ground into dust, and is inhaled 
 as such by those in the vicinity, we see, most probably, 
 the commonest mode of dissemination of consumption. 
 The greater frequency of the pulmonary over other forms of 
 the disease speaks in support of this view. 
 
 The secretions from those manifestations of the disease 
 usually classed as " surgical tuberculosis " also contain the 
 bacilli or their spores, and are capable of causing tubercu- 
 losis. With tuberculosis of the genito-urinary tract the 
 bacilli are found in the urine, while from intestinal tubercu- 
 losis they are thrown off with the discliarges from the bowels. 
 From skin-tuberculosis — lupus — they escape with the secre- 
 tions and with the i^articles of exfoliated epidermis. 
 
 An important factor in the dissemination of tuberculosis is 
 its occurrence in certain domestic animals, especially those 
 used as ibod. Though there is still a controversy with 
 regard to the danger of infection from the use of flesh and 
 
TUBERCCLOS/S. IO3 
 
 milk of tuberculous animals, it should be borne in mind that 
 bacilhts tuberculosis has been found in both, and so long as 
 this is the case these substances must be considered as pos- 
 sible disseminating factors, if not rendered harmless by thor- 
 ough cooking. 
 
 In addition, there are a multitude of ways in which dis- 
 semination may occur when consumptives are closely and 
 continuously associated with healthy individuals, as in the 
 case of man and wife, of parent and child, of patient and 
 nurse, etc. Without detailing every possible mode of dis- 
 semination under such circumstances, it will suffice to say 
 that the most frequent are perhaps infection through the 
 introduction into the mouth of the specific causative organ- 
 ism, by the hands that have been soiled with sputum or 
 secretions from the patient, by kissing and caressing, by 
 using the same eating utensils and drinking from the vessels 
 used by the patient, and by sleeping in the same bed with 
 the diseased person. 
 
 Portals of Infection. — The commonest portals of infec- 
 tion in man are the lungs, the alimentaiy tract, and wounds 
 of the skin. The disease may be produced experimentally 
 in susceptible animals by subcutaneous inoculation,, by inter- 
 peritoneal inoculation, by direct injection into the vascular 
 circulation, by the feeding of tuberculous materials, by the 
 introduction of the bacilli into the air-passages, and by inocu- 
 lation into the anterior chamber of the eye. 
 
 Contrary to the general rule for pathogenic bacteria, ba- 
 cillus tuberculosis apparently has the property of forming 
 spores, or of passing into a resistant condition analogous to 
 that of the spore-stage, within the living body. When thrown 
 off from the diseased body these resistant forms of the bacil- 
 lus survive the unfavorable conditions that they encounter, 
 such as drying, low temperature, scarcity or lack of nutritive 
 material, etc., and retain the power of producing tuberculosis, 
 when conditions favorable to the exhibition of this function 
 again present. The investigations of Cornet demonstrate 
 that bacillus tJibcrculosis in full possession of its pathogenic 
 powers may often be found in the dust of rooms occu- 
 
I04 nVG/EXE OF TRANSMISSIBLE DISEASES. 
 
 pied by tuberculous individuals. Some of the details of 
 these in\^estigations are most instructive : In 1 47 samples of 
 dust collected from general hospital wards, from asylums, 
 from prisons, from private apartments of consumptives, from 
 surgical wards of hospit?ls, and from other localities occa- 
 sionally visited by consumptives, bacillus tuberculosis was 
 demonstrated (by inoculation into guinea-pigs) to be present 
 59 times — viz. : 
 
 In 38 dust samples from seven hospitals it was found 20 times 
 
 "II " " three asylums " " 3 " 
 
 "5 " " two prisons " " o " 
 "62 " " private apartments 
 
 of consumptives " " 34 " 
 
 "3 " " surgical wards " " O " 
 
 " 28 " " other localities " " 2 " 
 
 From this it is clear that the inhalation of dust contaminated 
 with this organism, by individuals naturally susceptible or 
 vitally predisposed to this variety of infection, must be a 
 comparatively frequent channel through which the disease is 
 contracted. 
 
 It is not my intention to open here the familiar controversy 
 as to whether flesh and milk of bovines affected with the 
 lymphatic or pulmonary form of the disease contain the 
 bacillus of tuberculosis or not, but rather to call attention to 
 the point that through the careless handling of such flesh 
 and milk by butchers who slaughter tuberculous cattle, and 
 by dairymen who obtain the milk from diseased cattle, both 
 meat and milk may become accidentally infected, and if used 
 in the uncooked .state may serve as sources of infection. 
 
 Tuberculosis as a result of direct inoculation — i.e. through 
 wounds of the skin — is less important to man than are the 
 preceding modes of infection. When it does occur, the 
 process is usually localized to the site of infection. Tliere 
 is reason to believe, however, that general tuberculosis 
 may follow this mode of infection, though such a result is 
 rare. 
 
 The localized tubercular nodule resultinir from infection of 
 
TUBER Ci L OS IS. I O 5 
 
 wounds of the skin, familiarly known as " post-mortem " 
 tubercle, is encountered most frequently in those whose 
 duties bring them in intimate contact with the morbid tissues 
 of deceased tuberculous individuals and animals, as pathol- 
 ogists, butchers, workers in raw hides, etc. 
 
 Prophylaxis. — The most important prophylactic meas- 
 ure is thorough disinfection of the sputum and other dis- 
 charges from persons suffering from the various manifesta- 
 tions of the disease. Cornet states that for the ten years 
 ending with 1897 the death-rate from consumption in Ger- 
 many was 21.5 per 10,000 against 3 1.4 for a corresponding 
 previous period. He believes the result due to more general 
 efforts at the suppression of indiscriminate spitting and more 
 care in preventing tuberculous sputum from becoming dried 
 and disseminated through the air as dust. 
 
 The patient should be impressed with the fact that he is a 
 possible source of infection, and that it is quite within his 
 power to control the spread of the disease from himself by 
 attention to a few simple details that will in no way interfere 
 with his comfort. 
 
 If he be suffering from pulmonary consumption, the 
 sputum should be spat into covered vessels containing a dis- 
 infectant fluid, or into a vessel containing plain water, which 
 is subsequently to be boiled. Cheap paper sputum-cups 
 that can be burned after use are now to be had of all drug- 
 gists. The cups to receive the sputum, other than those of 
 paper that are to be burned, should be of china or enamelled 
 ware, and should be thoroughly scalded with boiling water 
 at least twice daily. When the patient is away from his 
 apartments and cannot use the sputum-cup, he should be 
 provided with cheap handkerchiefs or napkins, into which 
 he should expectorate, which should be burned after using. 
 A very good form of handkerchief for this purpose is the 
 paper " Japanese handkerchief" 
 
 Bed-clothing or night-clothing soiled with tuberculous 
 sputum should be at once removed and scalded. The con- 
 sumptive should be provided with his own eating utensils, 
 napkins, etc., and these should be used by him alone, and 
 
106 HYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 should be scalded immediately after use. The refuse from 
 his meals should also be scalded ; never used by others. 
 
 The living- and the bed-room of the patient should be kept 
 scrupulously clean, and should be frequently aired. Under 
 no circumstances should spitting about the room be per- 
 mitted. " Dusting " should not be practised, but when 
 necessary all objects should be wiped with a cloth moistened 
 in I : looo corrosive-sublimate or 3 per cent, carbolic-acid 
 solution. The importance of this precaution is conspicuously 
 illustrated in Cornet's investigations, cited above, by the 
 marked difference between the dusts from medical wards of 
 hospitals, where there is more or less of laxity concerning 
 the importance of cleanliness as a factor in asepsis, and 
 the dusts from surgical wards, where this point is kept con- 
 stantly in mind. Kissing, caressing, shaking hands, and 
 other modes of intimate association should not be indulged in 
 by the consumptive. The hands should be thoroughly washed 
 after manipulating tuberculous patients. 
 
 By thorough cooking tuberculous meat and milk are ren- 
 dered free from danger. The slaughter of animals for public 
 consumption should be under authorized inspection and con- 
 trol, and the entire carcasses of animals found to be tubercu- 
 lous should be discarded and burned or buried. Similarly, 
 dairy herds should be periodically inspected by qualified 
 veterinarians, and the sale, of milk from all suspicious ani- 
 mals should be prohibited. Tuberculous individuals should 
 not be engaged about dairies. In recommending that the 
 marriage of consumptives should be discouraged, the writer 
 appreciates the almost total impracticability of the sugges- 
 tion ; but it is nevertheless the duty of the physician to dis- 
 courage such unions whenever the opportunity presents for 
 him to do so. 
 
ACUTE CROUPOUS PNEUMONIA. IO7 
 
 ACUTE CROUPOUS PNEUMONIA. 
 
 ^Lohar Pneumonia.) 
 
 Definition, Cause, etc. — An acute, specific inflammation 
 of the lungs due, in the vast majority of cases, to the pres- 
 ence in the diseased area of viicrococciis lanccolatiis (pneu- 
 mococcus). In a very small proportion of instances pneu- 
 monia, with all its anatomical and clinical characteristics* 
 has been observed to follow the invasion of other species 
 of bacteria — viz., streptococcus pyogenes, pneumobacillus of 
 Friedlander, and streptococci and stapJiylococci pyogenes to- 
 gether. In this disease the part played by a predisposing 
 cause appears to be eminently essential to infection. While 
 manifestly infectious, there is some room to doubt that the 
 disease is contagious in the strict sense of the word, though 
 numerous local outbreaks (house-epidemics, prison-epidemics, 
 barrack-epidemics, etc.) have been recorded. 
 
 Micrococcus Imiceolatus, also known as diplococcns pneii- 
 inoni(B, pneumococcus of Frankel, streptococcus lanceolatus 
 Pasteuri, Micrococcus pncianonicB crouposcB, diplococcus lan- 
 ceolatus capsulatus, micrococcus of sputum-septicemia, and 
 meningococcus, is, as its name implies, a lancet-shaped mi- 
 crococcus, usually found in pairs, though occasionally in 
 short chains. When in pairs the broad ends of the lancet- 
 shaped cells are in juxtaposition. When examined directly 
 from the diseased lung, as in the rusty sputum of patients, it 
 is found, by appropriate methods of staining, to be enveloped 
 by a delicate capsule (Fig. 10), though under artificial cultiva- 
 tion the capsule is rarely observed. 
 
 Micrococcus lanceolatus is not conspicuous for its sapro- 
 phytic tendencies ; it is difficult to cultivate, and at times 
 loses its vitality, after three or four generations, under arti- 
 ficial circumstances. Under these conditions it often becomes 
 rapidly diminished in virulence, though this is not always the 
 case. It is constantly present in the mouth-cavity of from 15 
 to 20 per cent, of healthy individuals ; by some it is thought 
 to be present in the mouth of every one at one time or an- 
 other, and it is found in the sputum of practically all persons 
 
108 JIYGIEXE OF TKAXSMISSIBLE DISEASES. 
 
 suffering from croupous pneumonia. It is demonstrated to 
 be the cause of a number of other pathological conditions — 
 viz., meningitis, acute ulcerative endocarditis, pericarditis, 
 otitis media, acute circumscribed abscess, and pleuritis. It 
 is an organism of very low resisting powers, and is readily 
 
 Fig. io. — Micrococcus lanceolatus (pneumococcus) in blood. 
 
 destroyed by either thermal or chemical methods of disin- 
 fection. 
 
 It does not grow at a temperature lower than 25° C, nor 
 above 42° C. The temperature most favorable to its growth 
 is that of the body — viz., about 37° C. Its thermal death- 
 point is 52° C. in ten minutes (Sternberg). 
 
 It is very pathogenic for white mice and rabbits, less so for 
 guinea-pigs. Subcutaneous inoculation of these animals with 
 this organism does not result in the production of pneumonia, 
 but instead, the animals succumb to a rapidly-fatal form of 
 septicemia. Pneumonia may, however, be produced in a fair 
 proportion of cases by the injection of either cultures of this 
 organism, or the juices from a pneumonic lung directly into 
 the lung-substance through the wall of the thora.x. 
 
 Geographical Distribution, Age, Sex, etc. — Pneu- 
 monia does not appear to be more frequent in one country 
 than in another. It occurs in both hot and cold climates. 
 It is most frecjuent in tliis latitude during January, Februaiy, 
 
ACUTE CROUPOUS PNEUMONIA. 109 
 
 and March. It attacks all ages — men more frequently than 
 women, and the aged more often than the young. 
 
 Modes of Dissemination. — Though, as stated, micro- 
 coccus lanccolatus usually loses its pathogenic properties 
 in a short time after having been cultivated under arti- 
 ficial circumstances, it is nevertheless observed to retain its 
 virulence for a comparatively long time in sputum, blood, 
 and other pathological exudates. Even when dried under 
 these conditions, it has been found to be virulent for as long- 
 as fifty-five days. It is not unlikely, therefore, that dried 
 pneumonic sputum may, when ground into dust, serve as a 
 means for the dissemination of pneumonia, just as dried 
 tubercular sputum is believed to be an important factor in 
 spreading tuberculosis. 
 
 When a number of cases occur simultaneously or in rapid 
 succession in isolated localities, the outbreak beginning with 
 almost explosive violence, as is sometimes the case, it is 
 reasonable to assume a common depressing influence that 
 predisposes numbers of persons to infection from some 
 common source ; these individuals then in turn serve as 
 sources for the further spread of the disease. As the pneu- 
 monic patient is the source from which the most highly 
 pathogenic varieties of the causative organisms are obtained, 
 it is clear that an individual predisposed by one debilitating 
 influence or another, when intimately associated with the 
 patient, would present conditions eminently favorable to 
 direct infection. The fact that the disease is not commonly 
 regarded as transmissible explains the indifference on the 
 part of many to precautions against infection, and it is 
 probably through such laxity that the disease is at times 
 contracted. 
 
 Furthermore, predisposing influences may so reduce the 
 normal resistance of the individual as to favor auto-infection 
 from his own mouth or nose-cavity by micrococcus lancc- 
 olatus that had hitherto existed there as a harmless com- 
 mensal species. Pneumonia is especially apt to follow upon 
 exposure to sudden and extreme variations in temperature, 
 upon exposure to excess of cold and moisture, and upon 
 
no HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 the debilitating effects of exhaustion, alcohoHsm, traumatism, 
 and diseases of other kinds. 
 
 Portals of Infection. — Our knowledge of the subject 
 does not permit of a definite statement as to the relative 
 frequency of infection from extraneous sources and auto- 
 infection from the mouth, or from other primaiy foci of dis- 
 ease in the body. Nevertheless, there is eveiy reason to 
 believe that, whatever the source of infection may be, the 
 disease results, in the vast majority of cases, from the 
 deposition of the morbific agent in the tissues of the lungs, 
 from either the mouth or nasal cavities, directly or by way of 
 the lymphatic or vascular circulation. 
 
 While much less frequent, it is still probable that pneu- 
 monia sometimes arises as a phenomenon secondary to a 
 primary site of pneumococcus infection in the body, the 
 causative agents being carried from the diseased area to the 
 lungs by the circulating fluids or wandering cells. 
 
 Prophylaxis. — The most important prophylactic meas- 
 ures are those directed to the maintenance of the general 
 tone of the body — /'. e. those that tend to support the normal 
 vital resistance of the tissues ; for, as stated above, this par- 
 ticular variety of infection is conspicuously favored by all 
 those predisposing causes of disease that tend to depress the 
 general vitality. 
 
 Careful attention should be paid to the hygiene of the 
 person, including regular meals of nutritious food, protection 
 by proper clothing from the influence of sudden and extreme 
 changes of temperature and of excessive cold and moisture, 
 rational e.xercise in the fresh air, and frequent bathing. The 
 excessive use of alcohol is generally regarded as a conspic- 
 uous factor in predisposing to pneumonia. 
 
 Those who are in attendance on pneumonia patients should 
 remember that the .sputum of such patients contains the living 
 morbific agents, and that it retains its power of infecting even 
 after being dried. The sputum should therefore be received 
 in covered cups containing fluid ; these should be scalded 
 with boiling water three or four times daily. Should the 
 hands become soiled with the s^jutum they should at once 
 
DIPHTHERIA. I 1 1 
 
 be washed with soap and water, and should always be thor- 
 oughly washed before meals. Attendants should refrain from 
 unnecessary, intimate contact with the patient. Eating-uten- 
 sils, refuse of food, soiled clothing, etc., should be scalded as 
 soon as removed from the ward or sick-room. 
 
 The sick-room should be kept thoroughly clean, should 
 be well aired without draughts, and should be properly lighted. 
 
 Attendants, often exhausted by their prolonged duties 
 with the patient, should observe carefully the directions 
 given above, and should bear in mind that they especially, 
 owing to the frequency of their lowered physical condition 
 and to their constant association with the patient, offer con- 
 ditions most favorable to infection. They should be particu- 
 larly attentive to their personal hygiene, and should endeavor 
 to spend a part of each day in the open air. 
 
 DIPHTHERIA. 
 
 Cause. — Diphtheria results from the pathogenic activity 
 of bacillus diphtlierice , discovered microscopically by Klebs, 
 and subsequently isolated in pure culture and proved by 
 Loffler to stand in causal relation to the disease. This 
 organism is therefore also known as the Klebs-Loffler bacillus 
 of diphtheria. 
 
 Diphtheria is an infectious disease which is also generally 
 regarded as contagious. 
 
 Bacillus diphtheri(Z is a non-motile, non-liquefying, non- 
 spore -bearing rod that is conspicuous for the irregularity of 
 its morphology. It may be recognized in microscopical 
 preparations, from either diseased area or from cultures, by 
 the following peculiarities : It occurs as irregularly stained 
 rods with one or both ends swollen ; as rods broken at 
 intervals into short, sharply-defined segments of either a 
 round or an oval shape ; as longer rods markedly clubbed 
 
112 HYGIEXE OF TR.U\SMISSIBLR DISEASES. 
 
 at one or both ends, and as short oval or lozenge-shaped 
 bt)dies. In some preparations one or another of these forms 
 will predominate ; in others they may all be observed together. 
 As a rule, they stain irregularly. Occasionally they take on 
 the dye with a moderate degree of regularity. Often sharply 
 defined, ver)' deeply .stained round or oval points will be seen 
 in the individual cells. It stains with the ordinary basic 
 anilin dyes. It grows readily on most of the ordinary 
 nutrient culture-media, especially those of a feebly alkaline 
 reaction that can be kept at the body-temperature. It is not 
 
 Fk;. ii.-^Showing three morphological variations of bacillus diphtherise : /, 
 as seen on glycerin agar-agar ; //, as ordinarily seen on neutral or slightly 
 alkaline Loffler's blood-serum mixture ; ///, as seen on slightly acid blood-serum 
 mixture. 
 
 readily destroyed by drying, and under these circumstances 
 has been known to retain its vitality for from ten to fourteen 
 weeks. It is readily destroyed by both thermal and chemical 
 means. Its thermal death-point is 58° C. in ten minutes. It 
 is destroyed in cultures by the direct action of sunlight in 
 from thirty to forty-five minutes. It is highly pathogenic for 
 guinea-pigs and kittens ; much less so for other animals used 
 for experiment. By subcutaneous inoculation in guinea-pigs 
 there is produced a local condition that is in many ways 
 analogous histologically to that seen locally in the throat of 
 human beings. 1^)\' introduction into the trachea of kittens a 
 
DIPHTHERIA. I 1 3 
 
 pseudomembranous exudate may be produced that is in all 
 respects similar to that occurring in man. 
 
 In human diphtheria, and in the experimental form, the 
 specific micro-organism is usually found only at the local site 
 of disease. By special methods they may often be detected 
 at more remote parts of the body, but in only very small 
 numbers. When present in the internal organs they do not, 
 apparently, play any part in the general process. The dis- 
 ease does not result, therefore, from the general invasion of 
 the body by the causative micro-organism, but from the dis- 
 semination of soluble poisons elaborated by it at the local 
 site of disease to which its activities are confined. It is to 
 the action of these poisons that the constitutional symptoms, 
 the secondary or concomitant manifestations, and the remote 
 degenerative processes of organs, commonly seen in diph- 
 theria, are due. 
 
 Geographical Distribution, Season, Age, etc. — The 
 disease has been known since the time of Galen. It has 
 been observed in practically all countries. It received its 
 name and was first definitely described and identified as a 
 distinct affection by Bretonneau, of Tours, in 1826, though 
 in 1 77 1 a pamphlet, entitled An Inquiry into the Nature, 
 Cause, and Cure of the Angina Siiffocation, etc., was pub- 
 lished by Samuel Bard, of New York, in which was given a 
 description of the cHnical and anatomical manifestations of 
 diphtheria that was quite comparable in its wealth of essential 
 details to that subsequently given by Bretonneau. 
 
 The disease is more common in cold and temperate than 
 in hot climates. It prevails much more extensively during 
 the autumn and early winter than at other seasons. It is 
 endemic in cities ; it frequently appears in an unusually 
 severe epidemic form in country districts. It occurs at all 
 ages, but the greatest number of cases fall between the third 
 and fifteenth years of life. 
 
 Modes of Dissemination. — Though contagious, it is 
 nevertheless probable that the disease is rarely contracted by 
 simply breathing the air of rooms occupied by diphtheritic 
 patients, for the reason that the specific micro-organism is 
 
 8 
 
114 I/YGlEiVE OF TRANSMISSIBLE DISEASES. 
 
 not contained in the breath of the patient, and is not elimi- 
 nated in this way in the course of ordinary quiet respiration. 
 It is, however, dislodged during coughing, sneezing, gagging, 
 etc., along with minute particles of false membrane from the 
 fauces. Nurses and physicians are especially liable to have 
 bits of membrane coughed into their faces during the usual 
 manipulations about the throat of the patient. It is accidents 
 of this kind that make the duties of attendants on diphtheria 
 patients particularly dangerous, and it is among such attend- 
 ants that instances of direct infection occurring in this way 
 are frequently observed. It is also to be noted that the 
 bacillus of diphtheria is not readily destroyed by drying, and 
 that when dislodged from the throat in bits of false mem- 
 brane it may retain its vitality for a long time. When such 
 particles of dried membrane are disintegrated, dissemination 
 may occur through the breathing of air laden with this infec- 
 tive dust. Similarly, napkins, clothes, towels, handkerchiefs, 
 bed- and night-clothing, on which saliva from the patient has 
 been allowed to dry, may serve in this way to spread infec- 
 tion. Wright and Emerson detected living diphtheria bacilli 
 in the hair and on the shoes of nurses, and in a broom in the 
 diphtheria ward of the Boston City Hospital. 
 
 Through inattention to the hands, soiled while manipulat- 
 ing the patient, the disease may readily be disseminated. In 
 short, all modes of immediate contact with the diseased per- 
 son offer opportunities for infection. There is a pretty wide- 
 spread belief that domestic animals are instrumental in spread- 
 ing the disease. This opinion is based on the fact that cer- 
 tain animals, notably calves, cats, and chickens, suffer from a 
 pseudomembranous inflammation of the mucous membrane 
 of the upper air-passages that has been taken to be diph- 
 theria. This view is usually erroneous. Those affections 
 common to animals, that simulate diphtheria in man, are eti- 
 ologically totally distinct from human diphtheria, and genu- 
 ine diphtlieria cannot be contracted from animals affected 
 with those diseases. It must be said, however, that cats are 
 reported to have suffered from diphtheria contracted from 
 human beings. 
 
DIPHTHERIA. 1 1 5 
 
 A number of epidemic outbreaks of the disease have been 
 traced to the milk-supply of those affected. This has given 
 rise to the supposition that one or more of the cattle from 
 which the milk was obtained were diphtheritic. There is no 
 trustworthy evidence that cattle ever suffer spontaneously 
 from a disease capable of transmitting diphtheria to man. 
 When " milk-epidemics " of diphtheria do occur, they are 
 probably in all cases due to contamination of the milk with 
 the genuine diphtheritic virus from human sources — /. e. 
 from the family of the dairyman, or from some of the others 
 through whose hands it passes before reaching the con- 
 sumers. 
 
 There is no evidence to support the opinion that the dis- 
 ease is disseminated by the water. Neither is there any evi- 
 dence, though opinion in abundance, that the disease is spread 
 by the air of drains and sewers. Where, through defective 
 plumbing, there is a direct passage for the infective materials 
 thrown into closets and sinks, through leaks in the soil-pipes, 
 it is manifest that the disease may be spread by such mate- 
 rials finding their way into other parts of the building and not 
 into the sewers, as intended. Barring such a condition as 
 this, it is difficult to conceive the way in which the air from 
 sewers may play a part in disseminating diphtheria, or in 
 fact any other variety of infection. All statistics show us 
 that those constantly engaged about sewers, and on sewage 
 farms, are not more liable to infective diseases than are those 
 following other occupations. The air of sewers is poorer in 
 micro-organisms of all kinds than is that of the overlying 
 streets ; the chemical composition of the air of sewers is not 
 such as to warrant the opinion that it is irritating and when 
 breathed predisposes the respiratory mucous membranes to 
 infection by its irritating qualities ; moreover, when leaking 
 into a room it becomes so diluted by the air in the room as 
 hardly, if appreciably, to alter the chemical composition of 
 that air. 
 
 Portals of Infection. — For faucial diphtheria the por- 
 tals of infection are the nose or mouth. Diphtheritic inflam- 
 mations, etiologically identical with diphtheria, are occasion- 
 
Il6 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 ally observed in other localities — viz., on other exposed 
 mucous surfaces, as conjunctiva, vagina, etc., and upon 
 wounds of the skin that have become infected with the spe- 
 cific diphtheria virus. During the course of the disease in 
 the fauces, auto-infection of wounds on exposed surfaces of 
 the body is not rare. 
 
 Infection of the nasal mucous membrane often results in a 
 more or less chronic process, known as membranous or 
 fibrinous rhinitis, though the acute manifestation of the dis- 
 ease is likewise observed in this locality. 
 
 Prophylaxis. — The most modern, and certainly the most 
 important, prophylactic measure is that through which a con- 
 dition of immunity from the disease is afforded by the sub- 
 cutaneous injection of the blood-serum from an animal that 
 has been artificially rendered highly immune from the poison 
 of diphtheria. As the immunity thus induced is not perma- 
 nent, lasting for but a few weeks at most, this procedure is 
 only employed when healthy persons are directly exposed to 
 the disease, especially as in the case of the well children of a 
 family in which the disease is present. 
 
 As the site of infection is the local area of diphtheritic 
 inflammation, it is plain that all objects in any way contam- 
 inated with matters from this area are infective, and should be 
 scalded as soon as removed from the patient. These patients 
 should be provided with separate eating utensils, which should 
 be scalded after each meal. The refuse from meals should 
 be scalded with boiling water. Soiled bed- and body-clothing 
 should be scalded before the secretions are permitted to dry 
 upon them ; or, where this is not practicable, the soiled areas 
 should be moistened with 3 per cent, carbolic-acid or i : lOOO 
 corrosive-sublimate solution. 
 
 Nurses and physicians should guard against infection by 
 thoroughly washing and disinfecting the hands immediately 
 after manipulating the patient. While spraying or otherwise 
 attending to or examining the throat, a cotton mask, moistened 
 with either of the above-named solutions, should be worn ; 
 this to guard again.st infection that might otherwise result 
 
DIPHTHERIA. I I / 
 
 from bits of membrane being coughed into the mouth, nose, 
 or face. 
 
 These patients, where possible, should occupy a room in 
 an unfrequented part of the house, and should be isolated, in 
 the full sense of the word, as completely as possible ; that is 
 to say, only those in immediate attendance should have access 
 to the room, and all articles that have been about the patient 
 should be scalded or otherwise disinfected before they leave 
 the sick-chamber. 
 
 From the standpoint of prophylaxis it is important to note 
 that the diphtheria bacilli do not, as a rule, disappear from the 
 throat with the disappearance of the false membrane, but 
 often persist far into the period of convalescence. In the 
 experience of the Laboratory of the Board of Health of Phil- 
 adelphia it is found that the average period of persistency of 
 diphtheria bacilli in the throats of convalescents from this dis- 
 ease is twenty-nine days, reckoned from the date of establish- 
 ment of the diagnosis by the primary bacteriological exami- 
 nation. In one case they were present after one hundred and 
 twelve days, while in a very few cases they disappeared as 
 early as the seventh day after their first detection. 
 
 Because of the persistence of the infective agent in the 
 throat of these patients, convalescents from diphtheria are 
 now regarded as dangerous sources of infection until they 
 are shown to be otherwise by bacteriological examination of 
 the throat — /. e. until such examinations demonstrate the 
 disappearance of the bacilli. 
 
 Note. — Processes of disinfection are given in the Section devoted to that 
 subject. 
 
Il8 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 EPIDEMIC CEREBROSPINAL MENINGITIS (CERE- 
 BROSPINAL FEVER; SPOTTED FEVER )» 
 
 Definition, Cause, etc. — An acute infectious disease, 
 the clinical manifestations of which are referable to a sero- 
 purulent inflammation of the meninges of the brain and 
 spinal cord. 
 
 Though sporadic cases are occasionally encountered, the 
 tendency of the disease is to appear simultaneously among a 
 number of the individuals of a community. 
 
 The cause of the disease is now generally regarded as the 
 micrococcus described by Weichselbaum in 1887 under the 
 name of diplococciis intracelhdaris meningitidis. As its 
 name implies, this organism is found usually in pairs, the 
 surfaces in juxtaposition being flattened, and usually located 
 within the bodies of the pus-cells of the exudate in veiy much 
 the same way that the gonococcus is located in the pus-cells 
 of gonorrhea (see Fig. 16). It can readily be detected in the 
 cerebrospinal exudates in genuine cases of this disease by 
 microscopical examinations of cover-slip preparations. Its 
 detection in this way in the spinal exudate obtained by lum- 
 bar puncture during the early stages of the disease places the 
 diagnosis beyond doubt. 
 
 This organism can be cultivated, but with difficulty. The 
 media most favorable to its cultivation are the solidified blood- 
 serum mixture of Loffler and nutrient agar-agar, though 
 occasionally it will not develop on either, even though it 
 may have been easily detected in the exudate on microscopi- 
 cal examination. It grows only at body-temperature. It is 
 decolorized when treated by the method of Gram. It stains 
 with the ordinaiy anilin dyes. Councilman, Mallory, and 
 Wright found that cultures of it lost their vitality in eight 
 da)'s ; that ^\•hen dried it died in from twenty-four to seventy- 
 two hours, according to circumstances ; that it was killed in 
 from four to seven hours by exposure to mixtures of formal- 
 dchyd gas and air in proportions of from i : 7500 to i : 
 225,000; and that a solution of i : 800 carbolic acid prevents 
 growth. 
 
EPIDEMIC CEREBROSPINAL MENINGITIS. II9 
 
 The results of the injection of either the exudate or of cult- 
 ures from it into animals in the ordinary ways are uncertain. 
 Heubner, and Councilman, Mallory, and Wright succeeded 
 in producing the typical pathological lesions of the disease by 
 direct injections into the subarachnoidal space of the goat. 
 Heubner's animal died in thirty-six hours, while that of the 
 Boston investigators lived for only seventeen or eighteen 
 hours ; both of which experiences testify to the very great 
 virulence of the materials employed by them. 
 
 It must be borne in mind that epidemic cerebrospinal men- 
 ingitis should not be confused with the other forms of menin- 
 gitis from which it is etiologically distinct. Sporadic cases of 
 cerebrospinal meningitis are from time to time encountered, 
 the etiological factors of which are not the same in all in- 
 stances. Typical cerebrospinal meningitis may be caused 
 by streptococcus pyogenes, by micrococcits lanceolatiis (pneu- 
 mococcus), and by bacillus tuberculosis, though tubercular 
 meningitis has certain anatomical points of distinction that 
 readily aid in its identification. These types of meningeal 
 infection, unlike epideviic cerebrospinal meningitis, show no 
 tendency to occur in the form of widespread outbreaks, but, 
 as stated, are encountered only as sporadic cases. 
 
 History, Distribution, etc. — The first authentic ac- 
 count of this disease as it is to-day recognized is that 
 given by Vieusseaux of the epidemic in Geneva in 1805 ; 
 though there can be no doubt that the disease had appeared 
 elsewhere prior to that date. Since then epidemics of vary- 
 ing degree have been described in almost every part of the 
 civilized world. The year after the description of the disease 
 by Vieusseaux, Danielson and Mann first called attention to 
 its occurrence in this country. After its primary appearance 
 in Massachusetts in 1806 it continued throughout New Eng- 
 land in various localities for the subsequent ten years. In his 
 elaborate article Hirsch distributes the epidemic occurrence 
 of this disease through four periods, namely 1805- 1830; 
 1837-1850; 1854-1875; 1876 to date. In the first period 
 it appeared in isolated epidemics in Europe and to a much 
 greater extent in the United States ; in the second period 
 
I20 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 widespread epidemics occurred in France, Italy, Algeria, 
 the United States, and Denmark ; during the third period it 
 included Europe, Asia, Africa, South America, and the 
 United States ; while in the last period it has been especially- 
 marked in German)', Italy, and the United States. In com- 
 menting further upon this disease Hirsch expresses the opin- 
 ion that it is becoming more and more circumscribed in its 
 occurrence and that it can hardly be longer regarded as an 
 endemic disease of the people. 
 
 A singular feature of the disease is its comparativ^e lack of 
 extension by continuity. Its appearance in a community is 
 usually characterized more by its simultaneous occurrence 
 in a number of individuals, not necessarily closely associated, 
 than b)- its gradual extension from one person to another. It 
 is also common for the disease to manifest itself in widely 
 scattered localities; thus, for instance, in 1857 it appeared 
 simultaneously in North Carolina and in western New York. 
 It is manifest that the peculiar distribution and occurrence of 
 the epidemics in no wise tend to simplify the study of all the 
 factors concerned in their causation, dissemination, etc. 
 
 Its outbreak at some time and place may comprise but a 
 few scattered cases, while at another place, but simulta- 
 neously, large numbers may be affected. At one period it 
 may be coniparatively mild, at another alarmingly severe. 
 It may reappear as a widespread epidemic of a very virulent 
 type in localities in which it had appeared previously in only 
 an insignificant way. It may appear in several occupants of 
 the same house, or in persons who have temporarily resided 
 in the same house with one sick of the disease, giving rise to 
 the opinion that it is transmitted by contagion. On the other 
 hand, single cases often occur in a family, the members of 
 which are intimately associated with one another, and all 
 others may escape. It has appeared in a house, disappeared 
 for a time, and reappeared. 
 
 Age, Social Condition, Season, Mortality, etc. — 
 Epidemic cerebrospinal meningitis is a disease of cliildhood 
 and earl)- adult life. It is rare before one year, and gradually 
 diminishes in frequency after thirty years of age. Though 
 
EPIDEMIC CEREBROSPINAL MENINGITIS. 121 
 
 the concomitants of poverty usually seem to predispose to 
 the disease, there is abundant evidence to demonstrate that 
 these conditions are not essential to its causation. In the 
 recent epidemic in Boston, for instance, the cases, with the 
 exception of a limited area along the water-front, were pretty 
 evenly distributed throughout both the poorer and better 
 parts of the city. 
 
 It is a disease of late winter and early spring. It has been 
 known to disappear with the onset of warm weather ; it has 
 been known to make its appearance in warm weather. Pro- 
 longed rain is thought by some to favor it. Excessive cold 
 is thought by others to favor it. Available evidence does not 
 justify the opinion that atmospheric conditions per se have 
 or have not anything to do with its advent. 
 
 The mortality varies according to the severity of the epi- 
 demic from 25 to 70 per cent, of all affected. In the Boston 
 outbreak of 1896- 1897, 68.5 per cent, of the iii cases seen 
 in three hospitals proved fatal. Rollet, in presenting the 
 statistics on this point for all epidemics in France up to the 
 year 1884, records seven in which the mortality was less 
 than 50 per cent, and nine in which it was above 50 per 
 cent. ; in the former group the lowest mortality was 28 per 
 cent, in the latter the highest was 75 per cent. 
 
 Hirsch states that the disease is more common among 
 negroes than whites, but he is inclined to regard this as due 
 less to racial peculiarity than to social conditions. 
 
 It is a disease of subtropical and temperate climates, and 
 is, according to Hirsch, unknown in the tropics and rare in 
 colder regions. 
 
 Portals of Infection, Modes of Dissemination, etc. 
 — When we remember that the essential lesion of the dis- 
 ease is enclosed within bony cavities and that it is usually 
 confined to the tissues in these cavities, it is evidently 
 difficult to offer any satisfactory opinion as to the channels 
 through which primary infection took place, or those through 
 which the specific micro-organism may be eliminated from 
 the diseased person, both points being requisite to an accu- 
 
122 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 rate undcrstandinij of the phases of the subject under con- 
 sideration. 
 
 There can be no doubt that infection occurs from without ; 
 that the infective matters are carried to the meninges through 
 either blood or lymphatic channels or both ; but whether it 
 enters the body through the alimentary or respiratory tracts 
 or through superficial wounds it is not possible to say. 
 
 In severe epidemics fatal results occur so quickly after the 
 onset of the disease that in many cases there is no involve- 
 ment of other organs than those within the cranium and 
 spinal canal, and the specific micro-organism is confined to 
 these localities. It is hardly conceivable, therefore, that these 
 cases serve as sources from which attendants or other indi- 
 viduals in association with the sick may contract the disease. 
 In a certain proportion of cases there is secondary involve- 
 ment of other organs that communicate more freely with the 
 surface of the body — /. c. secondary pneumonia, middle-ear 
 inflammations, and involvement of special organs and of mu- 
 cous and serous surfaces may be encountered. If the dis- 
 ease is really transmissible from person to person, it is prob- 
 ably this group of cases that is most favorable to it. It 
 must be said, however, that the bulk of evidence does not 
 lead to the opinion that epidemic cerebrospinal meningitis is 
 a directly contagious disease, or that it is often carried from 
 the sick to the well by fomites. The history of numerous 
 outbreaks leads more to the opinion that the cases are in- 
 fected from some common source, and that they are predis- 
 posed to such infection by some unusual local condition. 
 This opinion is supported by the peculiarity of the epidemic 
 outbreak of this disease as noted above — namely, that it 
 shows no special tendency to progress along continuous lines 
 or through contiguous localities. It may appear suddenly in 
 a locality, and as suddenly disappear to reappear almost at 
 once in some remote district. It has been known to appear 
 in two regiments in camp, while a third, located between the 
 infected regiments, escaped. Love states that at New Orleans 
 in 1847, the disease attacked one regiment which was quar- 
 tered in poor barracks on damp soil, and supplied with poor 
 
EPIDEMIC CEREBROSPINAL MENINGITIS. 1 23 
 
 clothing, while an adjacent regiment, more favorably housed 
 and clothed, escaped entirely. The history of the disease is 
 characterized throughout by irregularities in the manner of 
 its occurrence and the conditions under which it has made its 
 appearance. At times it has prevailed in rural districts, the 
 cities remaining comparatively free, while again the reverse 
 has been the case. 
 
 Prophylaxis. — From what has been said, it is manifestly 
 impossible to outline a rational scheme of prophylaxis against 
 this disease. We lack what underlies all such systems — 
 namely, precise knowledge of the manner of infection and the 
 channels of dissemination of this malady. 
 
 Since it is improbable that the disease is transmissible from 
 person to person, rigid isolation of the sick is not generally 
 regarded as imperative. In the protracted cases, especially 
 those with secondary involvements, the discharges and ex- 
 creta should be disinfected as soon as passed. The dead 
 should be disposed of by burial or cremation as soon after 
 death as decency and circumstances will permit. 
 
 Since the evidence leads us to regard the occurrence of the 
 disease as favored frequently by local predisposing conditions, 
 such as bad hygienic environment in general, too much care 
 cannot be given to the sanitation of the house, personal 
 hygiene, and those measures that prevent infection by way of 
 food and drink. ^ 
 
 1 Read Hirsch : Pathologische Geoi^raphie, Bd. iii., S. 379 ; Councilman, 
 Mallory, and Wright : Epidemic Cerebrospinal Meningitis and its Relation to 
 other Forms of Mejiingitis ; a Report of the State Board of Health, Mass., 
 1898 ; Stille : System of Medicine, vol. i., 1885. 
 
124 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 INFLUENZA. 
 
 Cause. — Influenza is an infectious catarrhal process in 
 ^\-hich the causative micro-organism, probably bacillus infiii- 
 cnzce, is localized in the respiratory tract. The accompany- 
 ing constitutional manifestations are apparently of toxic 
 origin, resulting from the absorption by the blood of toxins 
 produced by the growing bacilli in bronchial mucous mem- 
 branes. The bacillus of influenza is a very small, non-motile, 
 non-spore-bearing, non-liquefying rod that is constantly to be 
 found in the sputum of individuals suffering from influenza. 
 It stains less readily with the ordinary basic anilin dyes than 
 
 Fig. 12. — Bacillus influenzae in sputum. 
 
 do other bacteria. It does not stain by Gram's method. It 
 may be isolated in pure culture from the sputum of influenza 
 patients. It cannot be readily cultivated on the ordinary 
 nutrient media. It grows only at body-temperature and upon 
 the surface of media over which has been distributed either 
 blood or blood-coloring matter. The coloring matter of the 
 blood appears to afford substances especially adapted to the 
 nutrition of this organism. Its colonies appear as very 
 minute, discrete, colorless points of growth that have some- 
 what the appearance of small drops of dew. 
 
INFLUENZA. 12$ 
 
 It is extremely sensitive to drying, withstanding the process 
 at 20° C. for but little over twenty-four hours. 
 
 The results of inoculation of animals with cultures of this 
 organism indicate that under these circumstances its path- 
 ogenesis depends more upon toxic than upon actively infec- 
 tive properties. 
 
 Occurrence, Distribution, etc. — Influenza appears 
 usually in an epidemic form, having its origin in some one 
 locality or another and travelling with great rapidity, often as 
 a true pandemic, over the major part of the inhabited earth's 
 surface. 
 
 According to Hirsch, the first trustworthy literary records 
 of the disease date from the early part of the twelfth century. 
 Between 1 173 and 1874 it made its appearance on eighty-six 
 different occasions. Its first recorded occurrence in the 
 United States was in Massachusetts in the summer of 1627; 
 since that time it has visited this country with varying 
 degrees of severity twenty-two times. The last pandemic, 
 that of 1 889-1 890, appears to have originated in Central 
 Asia and to have spread thence to Russia, Germany, France, 
 England, and finally to North America. Its occurrence 
 does not seem to be influenced by climate, season, geological 
 or geographical conditions. The ideas regarding the peri- 
 odicity of its visitations, and that relating to the fixity of the 
 direction of its spread from east to west, receive no support 
 from Hirsch's analysis of the various epidemics. Neither 
 race, sex, nor age appears to serve as an important predis- 
 posing factor. 
 
 Dissemination. — It is impossible to say what the condi- 
 tions are that favor its development and spread. Its dissemi- 
 nation over large areas is often so rapid as hardly to admit 
 of the explanation that it is carried from place to place by 
 travellers or through merchandise. The fact that the organ- 
 ism which is believed to be its cause is quickly destroyed by 
 drying contraindicates in a measure the opinion that the 
 virus is transported from one locality to another by winds. 
 Undoubtedly the spread of the disease is, in part at least, 
 accomplished through infected travellers. Our knowledge is 
 
126 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 not sufificient to allow of the statement that it is directly 
 transmissible from individual to individual, but a great deal 
 of circumstantial evidence points to this as being the case. 
 
 Mode of Infection. — On this point also our information 
 is but meagre, and it can only be said that in all likelihood 
 infection occurs through the respiratory tract. 
 
 Prophylaxis should consist in careful attention to the 
 hygiene of the person, the avoidance of all influences that 
 tend to lower the general tone of the tissues and, in so far as 
 is possible, non-communication with individuals already 
 affected with the disease. The invasion of the malady is 
 usually so subtle that prophylactic measures are of but little 
 avail. 
 
 The handkerchiefs, napkins, eating utensils, and the sputum 
 of influenza patients should be scalded before they are taken 
 from the sick-room. 
 
 When we remember how great a number of cases in any 
 epidemic of this disease are not confined to the house, it is 
 manifest that elaborate prophylactic measures can be opera-" 
 tive against only a part of those sick. The walking cases 
 cannot be brought under control ; these may be and prob- 
 ably are the most important disseminators of the infective 
 materials. 
 
 BUBONIC PLAGUR 
 
 Definition, Cause, etc. — An acute, specific, contagious (?) 
 disease that is characterized by inflammation, and in many 
 cases by suppuration of the lymphatic glands, especially 
 those of the inguinal, axillary, cervical, and submaxillar)' 
 regions. It is attended with great mortality. According to 
 Ycrsin, the death-rate among hospital cases during the late 
 epidemic in China was about 95 per cent. The investigations 
 of Yersin and of Kitasato point to a specific micro-organism 
 as the exciting cause, while all writers are at one in the 
 
BUBONIC PLAGUE. 12/ 
 
 opinion that the most predisposing causes are the common 
 concomitants of extreme poverty — namely, overcrowding, 
 filth, bad air, poor food, and intemperance. 
 
 The organism discovered by Yersin and by Kitasato in 
 cases of the disease examined by them during the epidemic 
 at Hong Kong in 1894, is described as a short, oval, cap- 
 sulated, actively motile, non-spore-bearing, polar-staining 
 
 Fig. 13. — Pus from bubo in bubonic plague ; showing the specific micro- 
 organism. 
 
 bacillus. It is present in large numbers in the suppurating 
 glands, and in smaller numbers in the blood. 
 
 It stains with the ordinary anilin dyes, taking up the color 
 more intensely at its ends than at its middle portion. It is 
 decolorized by Gram's method of staining. 
 
 It grows luxuriantly, without liquefaction, on solidified 
 blood-serum, as a yellowish-gray deposit. It may also be 
 isolated on agar-agar, especially when glycerin has been 
 added. It does not cause uniform clouding of the bouillon, 
 but grows in shred-like clumps that adhere to the sides or 
 sink to the bottom of the tube. The temperature most favor- 
 able to its growth is between 36° and 39° C. 
 
 It is destroyed in four days by drying at the ordinary tem- 
 perature of the room. Direct sunlight kills it in from three 
 to four hours. It is killed in a few minutes by steam at 
 
128 nVGIEXE OF TRANSMISSIBLE DISEASES. 
 
 ioo° C, and in half an hour by 8o° C. It is destroyed by an 
 exposure of two hours to carboHc acid, in 0.5 per cent, soki- 
 tion, and to milk of lime in i per cent, solution. 
 
 Rabbits, guinea-pigs, rats, mice, and sheep are susceptible 
 to subcutaneous inoculation with the plague bacillus. Pigeons 
 are immune. The lesions found at autopsy in animals dead 
 after inoculation, either with cultures of this organism or with 
 pus from a suppurating gland, while not apparently identical 
 with those seen in the human cadaver, do nevertheless pre- 
 sent certain features that may be considered as in part a 
 reproduction of the disease — namely, the marked involve- 
 ment of the lymphatic apparatus. The organism is found in 
 the internal organs of animals dead from inoculation. 
 
 Distribution, Race, Season. — Our knowledge of this 
 historic pestilence dates from about the end of the first cen- 
 tury of the Christian era. Its home was for centuries sup- 
 posed to be Northern Africa. During, and for a period after, 
 the Middle Ages, it was more or less frequently prevalent in 
 epidemic form in Asia Minor, China, India, Egypt, Arabia, 
 Northern Africa, Italy, France, Germany, and throughout 
 other parts of Europe. It appeared in Europe for the first 
 time during the reign of Justinian in the sixth century of the 
 present era. Beginning in Egypt in 542 A. D., it passed 
 during the next year to Constantinople and thence, during 
 the remaining half of the sixth century, it spread over pretty 
 much the whole of the Roman world. Ten thousand people 
 are said to have died of it in a single day in Constantinople. 
 Omitting the numerous outbreaks that occurred in the mean- 
 time, we encounter the historic visitation of the fourteenth 
 century — the " Black Death " — which, according to Haecker, 
 proved fatal to about 25,000,000 people — a quarter of the 
 entire population of Europe. During its prevalence at Oxford 
 in 1352, two-thirds of the academic j)opulation are said to 
 have succumbed. 
 
 There is a controversy among writers as to whether the 
 " Black Death " was an uncomplicated epidemic of bubonic 
 plague or not. It appears that a part of the mortality may 
 have been due to malignant typhus fever, a part to the so- 
 
BUBONIC PLAGUE. 1 29 
 
 called plague of India, and a part to true bubonic plague. 
 The unsanitary and social conditions of the people at that" 
 time were equally predisposing to either one of these pes- 
 tilences. 
 
 During the " Great Plague of London " (1664-65) the total 
 mortality for one year was 68,596 out of an estimated popu- 
 lation of 460,000, of whom two-thirds are supposed to have 
 fled to escape the contagion. The mortality rose during this 
 epidemic from 43 in May to 590 in June, 6137 in July, 17,036 
 in August, and 31,159 in September, after which there was a 
 decline. There was an epidemic of " spotted fever " at the 
 same time in London. 
 
 Though Northern Africa is considered the home of the 
 plague, it is interesting to note that the disease has now ex- 
 tended into the southern part of that continent. It has never 
 been known to cross the plains of India. It has never visited 
 America. 
 
 The mortality from bubonic plague varies in different epi- 
 demics from 53 to 95 per cent. 
 
 Race appears to have less predisposing influence than does 
 social condition. It is a disease preeminently of the poor 
 and destitute, its existence and spread being favored by the 
 manifold unhealthy conditions under which this class of 
 society exists. 
 
 During the recent epidemic at Hong Kong, China, the 
 deaths were distributed according: to sex and aee as follows : 
 
 Men 62.40 per cent. 
 
 Women 19.23 " 
 
 Boys 8.92 " 
 
 Girls 9.45 " 
 
 Telluric conditions seem to have but little influence upon 
 the existence of plague, as it has occurred in alluvial deltas, 
 along calcareous ridges, and on granitic mountains. Nor is 
 it apparently controlled by altitude, for epidemics have oc- 
 curred both along the low-lying borders of rivers, as along 
 the Nile, the Euphrates, the Volga, and the Thames, and in 
 9 
 
130 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 the mountains of India and Kurdestan, at elevations of from 
 5000 to 7000 feet above the sea. 
 
 The disease seldom occurs in the tropics. Season has ap- 
 parently no definite effect upon it. It has been seen to 
 appear and to diminish and disappear during both hot and 
 cold weather. 
 
 Dissemination and Modes of Infection. — Plague has 
 arisen so uniformly in unclean places that filth is generally 
 regarded as the most potent factor in favor of its origin and 
 spread. Almost without exception, plague-centers have been 
 characterized by a soil polluted with decomposing animal 
 matters, and by overcrowding of destitute, dirty, and poorly- 
 nourished people. An interesting and important fact that 
 points to the soil as the location of the plague-virus is the 
 observation that usually during, and often preceding, the ap- 
 pearance of the disease among human beings there is an epi- 
 demic of plague among rats, mice, and swine, particularly 
 rats and mice. 
 
 During the recent epidemic in Hong Kong the locality 
 most affected by the disease had a Chinese population equiv- 
 alent to 21,618 souls per acre of house-area. The mean 
 size of the main room of a house in this neighborhood was 
 26 by 14 feet by 10 feet high ; such a room served as living- 
 space for from 16 to 25 people. The personal habits of the 
 occupants are described as filthy beyond belief, cleanliness or 
 anything akin to it being apparently an unknown art. 
 
 Opinion is divided as to whether the contagion of plague 
 is disseminated through the air. It may be spread by means 
 of infected clothing and other objects that have been in use 
 by the patient. It does not seem to be carried from place to 
 place by means of merchandise. It is most often dissem- 
 inated from places in which it is either endemic or epidemic 
 to other localities, through human intercourse. It is improb- 
 able that the disease is spread to any great extent through 
 the use of infected water or food. 
 
 As a result of his investigations at Hong Kong, Aoyoma 
 expresses the opinion that in the great majority of cases, if 
 not in all, dissemination of the plague occurs through the in- 
 
BUBONIC PLAGUE. I3I 
 
 fection of skin-wounds, and much less frequently than has 
 been supposed by way of the respiratory and alimentary 
 tracts. He points out that during the epidemic physicians 
 and nurses who were in attendance upon infected individuals 
 and who spent much of their time in places where the sick 
 were lodged, rarely became affected ; and, further, of 300 
 Enghsh soldiers who volunteered to clean and disinfect the 
 pest-houses, only 10 contracted the disease. 
 
 This opinion, with the character of the evidence in support 
 of it, coincides with that of a number of observers who have 
 studied the course of the disease in other localities. Aoyoma 
 does not regard it as probable that an actual pest atmosphere 
 exists, an opinion at variance with that of a number of other 
 writers who insist that prolonged breathing of the air about 
 a plague patient is one of the certain ways of contracting the 
 disease ; at the same time they admit that the casual entrance 
 into a room occupied by such patients does not often result 
 in infection. 
 
 Prophylaxis. — The most important safeguards against 
 the generation and spread of plague are personal cleanliness, 
 the removal of organic* waste from about the dwellings, good 
 drainage of the soil, and the prevention of overcrowding. 
 
 When the disease first makes its appearance in a house, 
 the sick should be at once removed to a hospital and there 
 isolated. The healthy members of the household should be 
 quarantined and kept under observation for from ten days to 
 two weeks. In the meantime the house should be thor- 
 oughly cleaned and disinfected. The ceiling, walls, floor, 
 and all other surfaces should be scrubbed with a 3 per cent, 
 carbolic-acid or a i : 1000 corrosive-sublimate solution. The 
 furniture of the sick should be scrubbed with a 3 per cent, 
 solution of carboHc acid in warm water, and body- and bed- 
 clothing should be steamed for one hour at 100° C. ; all 
 articles of little value that have been about the patient should 
 be burned. With regard to the precautions to be taken 
 while in attendance upon the sick, it should be borne in mind 
 that the discharges from suppurating buboes, and possibly 
 the discharges from the bowels or the stomach, are infective. 
 
132 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 All objects, therefore, that have been soiled with such mat- 
 ters should be boiled or steamed at ioo° C. before beino- re- 
 moved from the sick-room. 
 
 Since infection most often occurs through abrasions of the 
 skin, care should be taken that infective materials do not 
 come in contact with wounds, scratches, etc., of the hands. 
 The hands should be carefully disinfected after the necessary- 
 manipulations of the patient. The great frequency with which 
 the deep glands of the groin were the first to become in- 
 flamed, during the late epidemic in Hong Kong, is explained 
 by the fact that the Chinese of the poorer classes wear no 
 shoes, and the virus gained entrance to the lymphatics, pass- 
 ing directly to these glands through small wounds of the skin 
 of the feet. In this epidemic (as in others) the soil was mani- 
 festly infected. 
 
 Those who die of the disease should be wrapped in a 
 sheet soaked in a i : lOOO corrosive-sublimate or 5 per cent, 
 carbolic-acid solution, and either buried or cremated at once. 
 
 Those who recover should be kept in quarantine under 
 medical observation for at least a month. Kitasato has 
 found the bacillus of plague in the blood of a patient as 
 long as three weeks after the beginning of convalescence. 
 
 Incoming ships from plague-infected ports should be sub- 
 ject to quarantine for a time sufficient to permit of thorough 
 medical inspection. If found to be infected, the sick should 
 be removed to hospital and the healthy members of the 
 crew isolated. The ships should then be thoroughly disin- 
 fected. In short, they should be treated the same as an 
 infected house (see above). 
 
 There is some question as to the propriety of preventing 
 the free migration of uninfected people from a place in which 
 plague prevails to localities that are free from it. Such emi- 
 gration enables many to escape the pestilence, and the danger 
 of their introducing the disease into their new abode may be 
 eliminated by a quarantine of sufficient time (from seven to 
 ten days) to demonstrate that none of them are already 
 afflicted with plague. If, after such detention, careful med- 
 ical inspection, and thorough disinfection of their clothing and 
 
SUPPURATIVE AND SEPTIC INFECTIONS. I 33 
 
 other belongings no cases of the disease are found, these 
 individuals may with reasonable safety be permitted to mingle 
 with the general public. 
 
 SUPPUFLA.TIVE AND SEPTIC INFECTIONS. 
 
 Under this head may properly be included the ordinary 
 suppurative troubles resulting from infection by the com- 
 mon pyogenic cocci — such, for example, as boils, abscesses, 
 phlegmons, etc. ; those conspicuous for their migratory ten- 
 dency, and which are usually due to a particular species of 
 pyogenic cocci, notably erysipelas, lymphangitis, etc. ; and 
 those general infections that partake of the nature of septi- 
 cemia and pyemia, and which may or may not be referable to 
 the common pyogenic cocci. 
 
 The treatment of these conditions together is thought 
 advisable, not because of etiological or clinical relationship, 
 but rather because of their common characteristics when 
 viewed from the standpoint of prevention. 
 
 The acute, circumscribed, inflammatory processes most 
 frequently result from the activities of the ordinary pus-pro- 
 ducing cocci, the most common of which is stapliylococcus 
 pyogenes aureus (Fig. 14). 
 
 This organism is a micrococcus that develops in the form 
 of irregular clusters. Its designation " aureus " signifies that 
 its growth is characterized by a golden or orange color. It 
 liquefies gelatin, coagulates milk, and on both nutrient agar- 
 agar and potato grows as a yellow or orange-colored deposit. 
 It grows at ordinary room-temperature, but better at the 
 temperature of the body. It is tenacious of life, and with- 
 stands drying for months. In old cultures it has been known 
 to retain its virulence for as long as a year. It is destroyed 
 in ten minutes by a temperature of 62° C. It does not form 
 spores, though it is usually regarded as one of the resistant 
 
134 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 cocci, for the reason that it does not readily succumb to those 
 influences that prove detrimental to most of the non-spore- 
 bearing pathogenic bacteria. In addition there are other 
 varieties of staphylococci that are associated with circum- 
 scribed inflammatory conditions. They are markedly less 
 pathogenic than the organism just mentioned. They are 
 designated by names indicative of the color of their colonies, 
 
 Fig. 14.— Pus showing presence of staphylococcus pyogenes aureus. 
 
 as seen under artificial cultivation — viz., staphylococcus pyo- 
 genes citrcns, lemon-yellow colonies ; staphylococcus pyogenes 
 albus, white colonies ; staphylococcus cpidcrniidis albus, a sta- 
 phylococcus frequently present in the epidermis and grow- 
 ing with white colonies. 
 
 By particular methods of inoculation suppurative lesions 
 similar to those observed in man may be produced in animals 
 through the employment of cultures of staphylococcus pyo- 
 genes aureus. In man this organism is the cause of a 
 variety of inflammatory conditions, notably boils, abscesses, 
 phlegmons, osteomyelitis, meningitis, acute ulcerative endo- 
 carditis, peritonitis, pleuritis, synovitis, etc. In fact, there is 
 hardly an inflammatory condition in which it has not at one 
 time or anotiier played the etiological role. 
 
 Those inflammations having a migatory or spreading ten- 
 dency, though also sometimes due to the organism just men- 
 
SUPPURATIVE AND SEPTIC INFECTIONS. I 35 
 
 tioned, are more commonly characterized by the presence of 
 another of the group of pyogenic bacteria — namely, strep- 
 tococcus pyogenes (Fig. 15), identical in all probability with 
 streptococcus erysipelatis. 
 
 This organism is characterized by its growth in chains — 
 i. e., it divides transversely in one direction of space, the 
 daughter-cells having the tendency to adhere together like 
 strands of beads. It does not grow luxuriantly under arti- 
 
 FlG. 15. — Pus from erysipelas, showing presence of streptococcus pyogenes. 
 
 ficial cultivation, its colonies ordinarily being hardly more 
 than very small points. Its growth is not accompanied by 
 the production of color. It does not liquefy gelatin, and in 
 transparent fluid media does not cause diffuse clouding, but 
 grows rather in thread-like clumps that cling to the sides and 
 sink to the bottom of the tube. It grows at ordinary room- 
 temperature and at that of the body. It is not readily destroyed 
 by drying, and has been detected on several occasions in the 
 dust and in the air of hospital wards that have been occupied 
 by patients suffering from infections in which it was present. 
 It is killed in ten minutes by from 52° to 54° C. (Sternberg), 
 It is conspicuous for the variability of its virulence. Cultures 
 are rarely encountered, even in those fresh from diseased tis- 
 sues, that exhibit marked disease-producing properties in 
 animals. At times it is capable, on inoculation, of causing 
 
136 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 general infection, while again the result may be a local ab- 
 scess or an erysipelatous inflammation about the site of 
 infection. The writer has encountered a culture of this 
 organism that produced, when injected into the circulation 
 of rabbits, diffuse miliary abscess-formations in the muscles, 
 similar histologically to those caused under the same circum- 
 stances by stapJiylococais aureus ; while, on the other hand, 
 when rubbed into a wound of the ear of another rabbit a 
 severe erj'sipelas resulted. The two conditions were not 
 observed coincidently in the same animal. 
 
 In general, this organism seems to be much more patho- 
 genic for man than for animals. It has been detected in a 
 number of pathological lesions in man, among which may be 
 mentioned erysipelas, spreading phlegmons, ulcerative endo- 
 carditis, puerperal peritonitis, the anginas of scarlatina and of 
 measles, pleuritis, pericarditis, pneumonia, and mixed with 
 the diphtheria bacillus in the diphtheritic false membrane. 
 
 The general infections that partake of the nature of septi- 
 cemia and pyemia, while usually due to the ordinary pyogenic 
 bacteria, are not always to be referred to this cause. There 
 is now a general consensus of opinion that under peculiar 
 predisposing influences a number of different organisms, not 
 usually regarded as pyogenic, may find conditions favorable 
 to their invasion of the body and to their development within 
 the circulating fluids and in the tissues. The wider applica- 
 tion of bacteriological methods to the study of septic infec- 
 tions has brought out the important and interesting fact that 
 the lesions found are not specifically related to definite bacte- 
 rial species, but may, under circumstances not entirely clear, 
 result from the activities of a variety of different species. 
 
 The predisposing causes which favor infection by any of 
 the foregoing pyogenic species of bacteria are those which 
 generally tend to depress vitality, viz. : chronic alcoholism, 
 anemia, I^right's disease, diabetes, and severe burns. 
 
 Recently delivered women are especially prone to erysip- 
 elas and septic infections. 
 
 Modes of Dissemination. — The causative micro-organ- 
 isms arc ])rcscnt in greater or smaller numbers in the dis- 
 
SUPPURATIVE AND SEPTIC INFECTIONS. 1 37 
 
 charges from all acute inflammatory processes. The pus 
 from old foci of suppuration is sometimes found to be free 
 from living bacteria, though the remains of dead micro- 
 organisms may often be detected microscopically. Under 
 these circumstances the causative organisms have died in the 
 products of their own pathogenic activities. 
 
 In the majority of cases the organisms found in the dis- 
 charges from acute processes are living and capable of light- 
 ing up inflammatory conditions when they gain access to 
 wounds. When dried they may be disseminated through 
 the air as dust, and may excite suppuration in abraded sur- 
 faces on which they may fall, though this is not now 
 regarded with the same degree of apprehension by surgeons 
 as it formerly was. The modern view concerning the modes 
 of transmission of these conditions is that in the vast majority 
 of cases the disease results from direct contact — that is, 
 through the use of unclean and infected hands and instru- 
 ments at the time of operation, and through the dressing of 
 healthy wounds with unsterilized materials. In the case of 
 erysipelas it is possible that the infection may be dissemi- 
 nated from the patient during the period of desquamation, 
 the specific micro-organism being conveyed by means of the 
 minute particles of exfoliated epidermis. All surgical accesso- 
 ries are capable of carrying infection, when not rendered free 
 from infective matters by thorough cleansing and disinfec- 
 tion before being employed on fresh wound-surfaces. 
 
 Probably the most common mode of dissemination for 
 surgical infections is through the operator, his assistants, and 
 nurses, because of inattention to their own personal condi- 
 tion. Individuals whose duties bring them frequently in 
 contact with matters that are more or less infective may 
 themselves be the agents for carrying such infections, unless 
 rigorous attention be given to the most thorough personal 
 cleanliness and to careful disinfection of the hands before 
 manipulating non-infected cases. 
 
 Both the local and general types of surgical infection may 
 and often do follow apparently insignificant wounds with 
 infected objects. So slight an injur)% for instance, as the 
 
138 HYGIEXE OF TKANSMISSIBLE DISEASES. 
 
 scratch of an infected pin, or the prick of an autopsy-scalpel, 
 or of an instrument used during the examination of such 
 virulent matters as the exudate of a septic peritonitis, have 
 resulted in a serious and sometimes fatal general infection. 
 
 Portals of Infection. — Open wounds, superficial abra- 
 sions, and excoriations of mucous surfaces are the com- 
 mon portals of infection. Wounds in which there has been 
 much insult to the integrity of the tissues, and much inter- 
 ference with local nutrition (circulation), are particularly 
 liable to suppurative complications. The results of wound- 
 infections are not necessarily limited to the primary site of 
 invasion. Through the dissemination of infective particles 
 from the point of their entry by way of the blood or lymph- 
 channels, infection may become general, or may occur sec- 
 ondarily as an isolated focus in some one or another of the 
 more remote internal viscera. 
 
 It does not follow that every wound which has been 
 exposed to infection necessarily becomes infected. In many 
 cases the weapons of defence provided by nature (vital 
 tissue-resistance) prove to be of sufficient vigor to overcome 
 the invading organisms, in which event primary healing 
 without infection, or with infection to but an inconsiderable 
 degree, occurs ; on the other hand, infection occurs when 
 the weapons of offence possessed by the invading bacteria 
 are potent to paralyze the usual vital activities of the tissues. 
 The process of infection must always be viewed as a contest 
 between pathogenic bacteria on the one side, with the toxic 
 products of their growths as weapons of offence, and the 
 tissues on the other, resisting with whatever degree of 
 natural vital energy the circulating fluids and cellular ele- 
 ments may be endowed. All agencies, therefore, that in any 
 way tend to depress this natural vital energy of the tissues, 
 either through their local or their constitutional mode of 
 action, deprive them of their only mode of defence and ren- 
 der them liable to infection. 
 
 Prophylaxis. — The prophylactic measures that arc of 
 most avail in preventing wound-infection are cleanliness and 
 protection of the injured tissues from infection from v/ithout 
 
SUPPURATIVE AND SEPTIC INFECTIONS. 1 39 
 
 during the process of repair. These procedures find their 
 field of greatest usefulness in hospitals and dispensaries, 
 where numbers of individuals suffering from injuries and 
 from various surgical infections are congregated together. 
 
 Without discussing the details of antiseptic technic as 
 practised by surgeons, it will suffice here simply to indicate 
 the cardinal points to be kept in mind in the prevention of 
 the diseases included in this category. 
 
 The hands should always be thoroughly washed and dis- 
 infected, after examining an infected wound, before proceed- 
 ing to manipulate other wounds either infected or fresh. The 
 instruments employed should have been thoroughly cleaned 
 by washing and wiping, and then disinfected — as good a 
 method of disinfection as any other is to boil them for ten 
 minutes in a 2 per cent, sodium-carbonate solution. During 
 the operation or at the dressing the alkaline solution should 
 be rinsed from the instruments with sterilized distilled water 
 before they are used about the tissues. All ligatures (not 
 those of animal tissue, such as catgut), sutures, and bandages 
 should be sterilized by steam before using. They should not 
 be removed from the sterilizer until needed. 
 
 Bandages and dressings that are removed from the wound 
 should not be permitted to remain about the room. If, for 
 reasons of economy, they are to be used again, they should 
 be disinfected and finally washed, dried, ironed, rolled, and 
 sterilized by steam. If not to be used again, they should be 
 burned. 
 
 It is not generally advisable to employ chemical disin- 
 fectants and antiseptics about wounds for the purpose of 
 prophylaxis, for the reason that they usually defeat the very 
 object for which they are employed, by converting the tissues 
 into a nidus favorable to the growth of micro-organisms. By 
 the action of such substances the vitality of the tissues is 
 often destroyed through the induction of necrotic changes, 
 and they are in this way deprived of the means with which 
 nature has endowed them for resisting infection. 
 
140 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 VENEREAL DISEASES, 
 
 ( GoJiofvhea and Syphilis. ) 
 
 Gonorrhea. — A specific inflammation of the mucous 
 membrane of the urethra in the male, and of the urethra, 
 cervix uteri, and glands of Bartholini in the female. It is 
 caused by a micrococcus discovered by Neisser, and com- 
 monly known as the " gonococcus of Neisser," or as micro- 
 coccus gonorrJicece. This organism is recognized microscop- 
 ically in gonorrheal pus by its tendency to occur in pairs 
 (diplococci) ; by its relation to the pus-cells — /. c, by being 
 located within the protoplasmic bodies of these cells (Fig. i6) ; 
 
 Fig. i6.— Pus of gonorrhea, showing presence of gonococci in the bodies of 
 several pus-cells. 
 
 and by its peculiar staining reactions — namely, its failure to 
 retain the stain when treated by the process of Gram, while 
 it stains readily when exposed to any of the ordinary basic 
 anilin dyes. Its failure to stain by the Gram method is one 
 of the most important differential reactions. It can be culti- 
 vated, but not on the ordinary nutrient media employed in 
 bacteriological work. (For the methods of cultivation see 
 recent works on Bacteriology.) 
 
 When kept at body-temperature artificial cultures of this 
 
VENEREAL DISEASES. 14I 
 
 organism have been observed to retain their vitahty for as 
 long as a month ; whereas at ordinary room-temperature they 
 die in about forty-eight hours. 
 
 It is destroyed in a {<t\\ hours by drying. It is non-patho- 
 genic for animals. Both gonorrhea and conjunctivitis have 
 been produced in man through the use of pure cultures of 
 this organism. 
 
 Syphilis. — A chronic infectious disease characterized by 
 manifold pathological lesions, of which the chancre, the 
 mucous patch, and the gumma are the most destructive. 
 
 Though numerous claims have been made for the dis- 
 covery of micro-organisms that stand in causal relation to 
 the disease, its etiology is still unknown. Of these claims, 
 the one that has received the greatest consideration is that of 
 Lustgarten. He described as the cause of syphilis an organ- 
 ism that he had discovered microscopically in the primary 
 sore, in the secretions of syphilitic ulcers, and in other syph- 
 ilitic lesions. This organism is a bacillus possessing many 
 of the characteristics of bacillus tuber ado sis, and evidently 
 belonging to the group of which the tubercle bacillus is the 
 most important member. In many respects it is identical 
 with a bacillus, morphologically like it, that is commonly 
 present in the smegma from about the prepuce and labia. It 
 likewise has peculiarities that are common to the bacillus of 
 leprosy. The four organisms mentioned — viz., bacillus 
 tuberculosis, bacilhis smegniatis, bacillus lepr<^, and bacillus 
 syphilidis — are distinguished microscopically from one another 
 by particular processes. (For the differential method see 
 works on Bacteriology.) 
 
 The so-called " syphilis bacillus " has not been isolated in 
 culture, nor has the disease been reproduced in animals by 
 inoculation with secretions from syphilitic ulcers, or with bits 
 of syphilitic tissue. Lustgarten's claim rests simply upon the 
 finding of this organism in syphilitic lesions by microscopical 
 methods. Though certain other observers have confirmed 
 Lustgarten's observations, a great many more have failed to 
 detect the organism after careful search through the most 
 promising materials. There is therefore considerable room 
 
142 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 for doubt as to the causal relation of this organism to 
 syphilis. 
 
 Dissemination, Modes of Infection, etc. — In the vast 
 majority of cases, both gonorrhea and syphilis are dissemi- 
 nated through actual contact with the secretions of diseased 
 tissues during sexual intercourse. The introduction of gon- 
 orrheal pus into the eye results in a serious variety of puru- 
 lent ophthalmia — viz., gonorrheal conjunctivitis, and a condi- 
 tion (ophthalmia neonatorum) not rarely seen in the new-born 
 of women affected with gonorrhea, may, and often does, 
 result in loss of sight unless promptly and judiciously 
 brought under medical treatment. It is not unlikely that 
 gonorrheal ophthalmia may be contracted through the use 
 of towels that have been employed by persons suffering from 
 gonorrheal urethritis. Syphilis may be disseminated, in addi- 
 tion to the usual way, through kissing and through the use 
 of drinking and eating utensils that have been used by per- 
 sons suffering from syphilitic lesions of the buccal mucous 
 membrane. It may be contracted by the wet-nurse who 
 suckles a syphilitic child, or may be given in a variety of 
 ways by a syphilitic nurse to a healthy baby that is placed in 
 her care. 
 
 It is occasionally contracted by physicians in the perform- 
 ance of professional duties, through the infection of wounds 
 in the hands with syphilitic secretions. 
 
 Attention of dentists has been called to the possibility of 
 their disseminating this disease from persons suffering from 
 lesions of the oral cavity, unless proper precautions be taken. 
 Bulkley has called attention not only to a case of syphilitic 
 infection transmitted in this way, but also to one in which the 
 operator himself contracted the disease through infection of a 
 wound of the finger. 
 
 In short, abraded surfaces when brought in immediate con- 
 tact with the blood or secretions from primaiy or secondary 
 lesions, in any way whatsovcr, are practically certain to be- 
 come infected. Syphilis may be transmitted by heredity. 
 
 It may be inherited from the father, the mother being 
 healthy, or frmii a s\-phi!itic mother. A most interesting 
 
VENEREAL DISEASES. 1 43 
 
 phenomenon is that embodied in Colles's Law — viz., " a child 
 born of a mother who is without obvious venereal symp- 
 toms, and which, without being exposed to any infection 
 subsequent to its birth, shows this disease when a few weeks 
 old — this child will infect the most healthy nurse, whether 
 she suckle it or merely handle and dress it ; and yet the child 
 is never known to infect its own mother, even though she 
 suckle it while it has venereal ulcers of the lips and tongue." 
 Hereditary transmission of the disease is most apt to occur 
 when conception takes place during the primary stages of 
 the disease. Syphilis in a parent may have apparently dis- 
 appeared under treatment, and yet offspring born subse- 
 quently may manifest inherited evidences of the disease. 
 
 The mortality among children born of syphilitic parents 
 is high. Kryhus ' states that in the Hospital St. Louis 24 
 per cent, of syphilitic women abort, and in the Hospital Lour- 
 cine 38 per cent, are liable to this accident. Of children born 
 of syphilitic fathers 48 per cent, die, while 78 per cent, suc- 
 cumb when both parents are affected with the disease. The 
 infantile mortality decreases with increase of chronicity of the 
 disease in the parents. Fournier states that in many hos- 
 pitals of Paris the mortality among infants born of syphilitic 
 parents reaches 84 to 86 per cent. 
 
 Prophylaxis. — That the vast majority of venereal dis- 
 eases originate through impure and irregular sexual inter- 
 course is a statement over which there can be little contro- 
 versy. 
 
 It is not my purpose to discuss here the moral aspect of 
 prostitution ; neither are we to be understood as endorsing 
 the evil by stating that it has existed as long as peoples have 
 existed, and from the present outlook there is little likelihood 
 of its disappearance. In view of the moral, social, and 
 physical ravages that follow in the wake of venereal diseases, 
 it behooves us to employ every measure that is within our 
 power to combat these maladies and lessen their frequency. 
 
 The trustworthy personal measure against venereal dis- 
 eases, as contracted in the usual way, is celibacy, and it is 
 
 ^ These de Paris, 1890. 
 
144 IIYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 the dut)' of the physician to teach this doctrine, even though 
 he may feel that its adoption is in many cases a matter of 
 grave doubt ; not because continence is an impossible condi- 
 tion, but rather because for many men it involves a kind of 
 personal discipline that they are loath to undertake. Sexual 
 desire is often one of the manifestations of stored-up energy 
 resulting from idleness and intemperance. The greatest aids 
 to a continent life are hard work, athletic exercise, temper- 
 ance in food and drink, and the avoidance of temptation. For 
 many men celibacy for an indefinite period is apparently im- 
 possible. Such men should be advised to marry, even though 
 personal sacrifices in certain directions must be made by so 
 doing. 
 
 That a large proportion of unmarried men prefer to satisfy 
 their sexual cravings by recourse to the usual method, rather 
 than endeavor to repress them, is a fact that cannot be ig- 
 nored ; and while the recommendation of personal preventive 
 measures to meet the exigencies of such cases may appear 
 as favoring immorality, it must be remembered th'at the task 
 now in hand is the prevention of disease, and not the en- 
 forcement of moral precepts. Under such circumstances 
 something may be done to prevent contagion by scrupulous 
 cleanliness and careful local disinfection after intercourse ; 
 but it must also be borne in mind that none of these meas- 
 ures affords certain protection. In a number of European 
 towns, especially in France, the use of disinfectant lotions by 
 prostitutes is rigorously enforced, with the result of consider- 
 ably reducing the frequency of venereal diseases. 
 
 The prophylactic measures of greatest efficiency are ad- 
 ministrative. The question of prostitution is a matter for the 
 State to consider in its relation to the public health. A per- 
 son afflicted with a venereal disease is a menace to the public 
 health, and is just as much a subject for State control as 
 would be a case of small-pox or of any other communicable 
 malady. In the majority of European countries laws have 
 been enacted that aim to limit the dissemination of these dis- 
 eases, and in the main their effect has been most salutary. 
 These laws provide for the registration, usually at a bureau 
 
VENEREAL DISEASES. 1 45 
 
 of the department of police, of all women who subsist by 
 prostitution ; for (in some places) their segregation in brothels 
 or in particular parts of the town ; and for their regular and 
 frequent examination by competent physicians who are de- 
 tailed for the purpose. In addition, the law should provide 
 for the treatment, without cost to the individual, of all vene- 
 real cases in hospitals properly equipped for the purpose. 
 
 In France, Germany, Denmark, and England (prior to the 
 repeal of the Contagious Diseases Act in the last-named 
 country in 1884) the relative frequency of venereal diseases 
 has markedly diminished as the methods of municipal con- 
 trol of prostitution have gained in efficiency. Nevertheless, 
 the enactment of these laws, operating manifestly for the 
 public good, has given rise to no end of controversy, and 
 has in some places (particularly in England) met with vig- 
 orous opposition from those who, fully aware of the existence 
 of an evil that cannot be eradicated, consider it as immoral 
 to sanction the only feasible plan for diminishing its baneful 
 influence upon the physical well-being of the community. 
 Where such laws have been enacted and enforced, their 
 result, more particularly upon the number of syphilitic 
 infections, has been most marked. This was conspicuously 
 noticeable at those army-posts in England that were under 
 the Contagious Diseases Act prior to its repeal in 1884. 
 
 An element that disturbs the still more successful opera- 
 tion of the law is everywhere recognized in clandestine pros- 
 titution that always obtains among women of a certain class. 
 It is usually impossible to bring all such women under the 
 operation of the law, though the experience of a number of 
 places shows that many of this class, realizing the material 
 advantages to be derived from skilful medical control and 
 attention, have voluntarily presented themselves for registra- 
 tion. Moreover, there is reason to believe that the frequent 
 and dignified medical inspection has in general an educational 
 influence upon public women. They realize that they are 
 under restraint ; they take better care of themselves, for they 
 are sent to hospital if found diseased, and their trade is neces- 
 sarily thereby interrupted ; and, while perhaps no better off 
 10 
 
146 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 moral 1)-, the}' are less frequently guilty of breaches of public 
 decency. At least, the experience of a number of places has 
 led to this opinion. 
 
 The experience of those communities in which laws for the 
 regulation of prostitution have been enacted has brought out 
 two important facts — viz., that the unlicensed, uncontrolled 
 public woman is the great source of dissemination of venereal 
 infection, and that by the enforcement of carefully constructed 
 municipal laws the amount of venereal disease may be mate- 
 rially diminished. 
 
 The results of medical examination of prostitutes in those 
 places in which registration is in force clearly illustrate the 
 dangerous nature of those women who are not regularly within 
 the operation of the law ; for instance, Commengue states 
 that of 913,291 registered medical examinations of prostitutes 
 in Paris between the years 1878 and 1887 syphilis was found 
 to be present per looo examinations 3.12 times in registered 
 prostitutes living privately, 2.70 times in registered prostitutes 
 in brothels, 23.96 times in work-girls, and 166 times in pros- 
 titutes not under control. Essentially the same proportions 
 held for gonorrhea, except in the case of work-girls, when it 
 was found to be 144.6 for lOOO of all examinations. In 
 Lyons Giraud found that from 1.34 per cent, to 1.61 per cent, 
 of registered women were diseased, while 33.11 per cent, of 
 those not under control were suffering from venereal troubles. 
 In Denmark (1889) venereal diseases were present in 4.27 
 per cent, of registered women under control ; in 1 7.64 per 
 cent, of non-registered women who voluntarily presented 
 themselves for examination ; and in 39.49 per cent, of clan- 
 destine prostitutes not under control and not regularly 
 examined. Illustrative of the influence of these laws: 
 when the registration laws were passed in Rostock in 1881, 
 the number of cases of syphilis that applied for medical 
 advice in that year was 240; during the six succeeding 
 years, under the influence of the law, the number of cases 
 was 269 in 1882, 164 in 1883, 1 13 in 1884, 92 in 1885, 92 in 
 1886, and 70 in 1887.^ While the Contagious Di.seases Act 
 
 * Hygienische Topographic von Rostock, 1889. 
 
VENEREAL DISEASES. I47 
 
 was in operation in England (1864- 1883), the amount of 
 syphilis was markedly diminished. Since the repeal of the 
 Act in 1884 venereal diseases in the army have reverted in 
 extent and severity to what they were before the Act was 
 passed. According to Balfour the admissions to army hos- 
 pitals in 1864 (the year before the enactment of the law) for 
 primary chancre were 108.6 per 1000. In 1872 the admis- 
 sions at the uncontrolled stations were still higher — viz., 123.2 
 per 1000 — while in the same year the admissions at the army 
 stations that were nnder the control of the Act were only 
 53.3 per 1000. 
 
 Parke states that the number of admissions to the hospitals 
 of all military stations under the Act (comprising a total of 
 30,765 men) from 1867-72 for primary venereal sore was 
 62.8 per 1000, while the admissions from these same stations 
 just after the repeal of the Act were no per 1000 in 1883 
 and 138 per 1000 in 1884. " So that things are rapidly fall- 
 ing back into their old evil conditions." Such statistics as the 
 foregoing require no comment. They tell their own story. 
 
 As has already been said, to many it may appear improper 
 to advocate a method by which the community acknowledges 
 and openly licenses a practice that is plainly a breach of 
 public morals. But the evil exists ; it is likely to exist ; and 
 nothing is gained — on the contrary much is lost — by calmly 
 closing the eyes to it. The evils of prostitution are more 
 far-reaching and are a greater menace to the public health, 
 morals, and happiness than a superficial examination would 
 indicate. It is our duty as physicians and as citizens to cir- 
 cumvent this evil, and we can do this only by seriously rec- 
 ognizing it, not by ignoring it. 
 
 As Osier aptly puts it : " If the offender bore the cross 
 alone, I would say forbear; but the physician behind the 
 scenes knows that in countless instances syphilis has wrought 
 havoc among innocent mothers and helpless infants, often 
 entailing lifelong suffering. It is for them he advocates 
 protective measures." 
 
148 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 LEPROSY. 
 
 Definition, Cause, etc. — A chronic, endemic, infectious 
 disease caused by a specinc micro-organism, bacillus Icprce, 
 which possesses certain peculiarities in common with bacillus 
 tuberculosis. 
 
 The disease occurs in three forms, viz. : 
 
 1. The tubercular leprosy, in which nodular eruptions 
 occur on the skin of the face, limbs, breasts, scrotum and 
 penis, and also on the mucous membranes. 
 
 2. The non-tuberculated or so-called " anesthetic leprosy," 
 in which the peripheral sensory nerves are at first involved. 
 This is followed after a time by a peculiar, flat, dry, scaly 
 eruption on the back, shoulders, posterior surfaces of the 
 arms, about the nails, and at times along the course of the 
 nerves. In the earliest stages the affected areas are hyper- 
 esthetic ; during the eruptive stage they become anesthetic. 
 
 3. Mixed tubercular leprosy — /'. c, a combination of the 
 two forms just mentioned. This is the least common mani- 
 festation of the disease. 
 
 The non-tubercular or anesthetic variety is that most 
 frequent in the Tropics. 
 
 Bacillus IcprcF, now generally believed to be the cause of 
 the disease, was discovered in the pathological lesions of 
 leprosy by Hansen and by Neisser between 1879 and 1881. 
 
 Morphologically, it is so like bacillus tuberculosis as to be 
 practically identical with it, though some authors consider it 
 to be shorter, a distinction that alone counts for but little. 
 It is said to be differentiated from bacillus tuberculosis by 
 special staining reactions. Though several authors (Bordoni- 
 Ufreduzzi, Ducrey, and Campana) claim to have cultivated 
 this organism, it is doubtful if it has ever been grown artifici- 
 ally. In fact, such a number of efforts to culti\'ate it from 
 skin-lesions by trustworthy' investigators ha\c resulted in 
 failure, that the general impression now is that the majority 
 of the bacilli seen in the tissues are dead. At all e\'ents, one 
 of their most frequent microscopical peculiarities is a con- 
 spicuous degree of apparent degeneration. 
 
LEPROSY. 
 
 149 
 
 On microscopical examination with low magnifying powers 
 of sections of leprous tissue stained by any of the methods 
 used for staining tubercle bacilli in tissues, the leprosy bacil- 
 lus is detected usually in enormous numbers. It will be 
 seen scattered through the tissue as smaller and larger 
 clumps of individual bacilH (Fig. 17). On examining these 
 clumps under a high magnifying power, they will usually be 
 
 Fig. 17. — Schematic representation of section through a lepra nodule : left 
 side of picture gives appearance under low magnifying power ; right side, the 
 appearance when highly magnified. In the latter the large lepra cells are 
 diagrammatically indicated. 
 
 found to represent single granulation-cells that are packed 
 with the bacilli — the so-called " lepra-cells " — of which a 
 large part of the new growth is composed. The bacilli are 
 irregularly stained, often irregular in outline, beaded and 
 broken, and, as said, usually present the appearance of 
 degeneration. The bacilli are also present in the secretions 
 that may exude or be squeezed from the leprous nodule in 
 situ. They have been found in the circulating blood, but 
 only in very small numbers. Sticker found them in the nasal 
 discharges from 128 out of 153 cases examined by him. In 
 only 23 of these 153 cases did he find them in the sputum. 
 They may be detected microscopically by the ordinary 
 methods used for the detection of tubercle bacilli in sputum 
 or in pathological secretions. 
 
150 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 The disease has never been reproduced in animals by 
 inoculation with fresh leprosy tissues or secretions. The 
 efforts to reproduce the disease in man by inoculation with 
 fresh leprosy tissue have been hardly more successful. 
 
 During the past fifty years an astonishingly large number 
 of individuals have permitted themselves to be inoculated 
 with the pathological products of the disease without leprosy 
 resulting in but a single instance, and there is doubt as to 
 this individual's freedom from the disease at the time of his 
 inoculation. In his resume of the literature on this subject 
 Walters ^ cites at least 73 authenticated inoculations of 
 human subjects. Some of these were in good health, others 
 suffering from other maladies, and others already leprous, 
 the inoculations in the last instance having been made on 
 non-affected parts of the body. In not a single case did 
 leprosy result. 
 
 The much-quoted case of Arnig, in which leprosy appeared 
 in a man sixteen months after he had inoculated him, loses 
 much of its value as a demonstration that leprosy may be 
 induced in this way, by a closer study of the conditions 
 under which the test was made. The subject, a Hawaiian 
 convict, had a family history of leprosy, several relatives 
 having died of the disease. Arnig himself does not consider 
 the results of his inoculation as a demonstration free from 
 objection. 
 
 Geographical Distribution, Race, etc. — Leprosy is 
 endemic in Japan ; on the coast of China ; throughout India 
 and the Indian archipelago ; in isolated districts along the 
 coast of Africa, especially that of western, northern, and 
 northeastern Africa, though it is also found in Cape Colony ; 
 along the southern shores of the Black Sea ; throughout the 
 Greek archipelago ; along the western coast of Norway ; in 
 Iceland ; in certain parts of New Brunswick and Nova 
 Scotia ; in Mexico ; among the Chinese in southern Cali- 
 fornia ; in Louisiana ; in the West Indies, especially Cuba ; 
 in Brazil, and in the Argentine Republic and the neighboring 
 districts. 
 
 1 Ccnti-nlhL fitr Bdklcriologic iDid Parasilciikundc, 1893, W\. xiii., S. 469. 
 
LEPROSY. 151 
 
 The character of the disease varies somewhat according to 
 location — viz., in the temperate and colder climates tubercu- 
 lar leprosy is the predominating form, while in the tropics the 
 anesthetic variety is more common. While occurring at all 
 ages and among all classes of people, it is seen oftenest among 
 the poor and destitute. According to Hirsch, the disease is 
 usually encountered in countries of heterogeneous popula- 
 tions, negroes and those of mixed blood being much more 
 frequently affected than are Europeans. In certain localities 
 in the Orient, where the disease is endemic, the Arabs and 
 pure-blooded East Indians have shown a peculiar insuscepti- 
 bility to it. 
 
 In the colder climates, as in Norway and Iceland, the 
 purity of the race has no apparent influence upon the fre- 
 quency of the disease. 
 
 Hirsch calls attention to the peculiar differences that are 
 seen in the reaction of the Jewish race to leprosy in different 
 parts of the world. In Jamaica, St. Vincent, and Surinam, 
 the frequency of the disease among the Jews is second only 
 to that seen in the negroes ; while in Syria, Damascus, Jeru- 
 salem, Bombay, and other places they are but rarely affected. 
 
 Dissemination, Modes of Infection, etc. — While no 
 doubt exists as to the infectious nature of leprosy, there is 
 little agreement of opinion as to its mode of dissemination. 
 
 The disease shows no special tendency to spread beyond 
 the boundaries within which it is endemic, and healthy indi- 
 viduals are known to have spent long years of intimate asso- 
 ciation with lepers without contracting the disease. 
 
 Many of those who have investigated the subject are of 
 the opinion that leprosy is rarely, if ever, transmitted from 
 the diseased to the headthy person by direct contact, while 
 other observers claim this to be its most frequent mode of 
 transmission. 
 
 The mass of evidence compiled by Hirsch in opposition to 
 its transmission by contact is very strongly in favor of the 
 view that this must be a very unusual mode of dissemination, 
 if it occurs at all. 
 
 Some believe that, as in the case of syphilis, one may often 
 
152 HYGrENE OE TRAXSMISSIBLE DISEASES. 
 
 be in intimate association with the diseased persons for long 
 periods without becoming infected, but finally in some inex- 
 plicable way the disease is contracted. It has been suggested 
 that, like syphilis, there may be periods when leprosy is emi- 
 nently communicable, while in other stages this peculiarity 
 is diminished or lost. There is a pretty general agreement of 
 opinion that the anesthetic is much less readily communica- 
 ble than is the tubercular variety of leprosy. 
 
 The disease starts with no primary sore or point of in- 
 vasion that can be accurately determined. Its usual mode of 
 onset as multiple foci leads to the opinion that through some 
 unknown channel a number of areas in the skin must have 
 served simultaneously as points of deposit for the morbific 
 causative agent. Whether such infection is from without, or 
 starts from some primary focus, the nasal mucous membrane 
 for instance, as is believed by Sticker, cannot be positively 
 affirmed. Nor can it be definitely stated that leprosy is con- 
 tracted by way of the lungs or alimentar}-' tract, though some 
 observers believe this possible. The negative results that 
 have followed inoculations in human beings lead to the opin- 
 ion that it cannot be transmitted by inoculation ; though 
 Hansen is of the opinion that it is often contracted through 
 abrasions of the skin, through the wearing of clothing that 
 has been worn by lepers, and through the intimate association 
 between the sick and the well, that is often observed among 
 the ignorant and destitute. 
 
 The increase of leprosy in late years in the Sandwich 
 Islands is held by some to be the result of direct transmis- 
 .sion, occurring very often through sexual intercourse. 
 
 At the first Leprosy Congress held in Berlin in Octoh)cr, 
 1897, various speakers on the subject expressed the belief 
 that the disease could be contracted by way of the mucous 
 membrane of the nostrils, and the skin about the face ; 
 through wounds of the skin ; that it could be disseminated 
 from the infected individuals through saliva and mucus from 
 the mouth and nose ; that it could be transmitted by the 
 handling of infected clothing ; that it could be carried by in- 
 
LEPROSY. 
 
 153 
 
 sects ; and that it could be conveyed through the milk of the 
 nursing mother to her child. 
 
 The perpetuation of the disease is believed, by those who 
 oppose the idea of its transmission by direct contact, to be 
 due to heredity. On this point, too, there is divergence of 
 opinion, though no one denies that inheritance is one of the 
 zvays through which it is disseminated. Hirsch, as a result 
 of his investigations, believes inheritance to be the only dem- 
 onstrated mode of transmission for leprosy, and in this opin- 
 ion a number, though by no means all, of the most compe- 
 tent authorities concur. 
 
 The opinion has been advanced that certain articles of food, 
 notably fresh, salted, and rotten fish (Jonathan Hutchinson), 
 pork, and decomposed rice, are especially predisposing to the 
 disease. Investigation readily demonstrates the fallacy of 
 this view. In several of the areas of distribution fish, in one 
 form or another, is the staple article of food for the entire 
 population, and yet leprosy does not spread beyond the con- 
 fines of the isolated districts in which it is endemic. 
 
 It has also been erroneously claimed that certain atmos- 
 pheric conditions favor the existence of the disease. No 
 connection can be established between leprosy and climate or 
 season. While frequent along the coasts, its general area of 
 distribution disproves a necessary dependence upon littoral 
 'conditions. 
 
 Prophylaxis. — It is manifest that without a clearer un- 
 derstanding of the mode of dissemination and the portals of 
 infection of a disease, any measures that may be recom- 
 mended for the prevention of its spread are of necessity un- 
 satisfactory and incomplete. From what has been said as to 
 the disagreement of opinion concerning the communicability 
 of leprosy, we are prepared for irregularities in the methods 
 employed in its management. In some places no attention 
 is paid to the disease at all ; the lepers mingle with the gen- 
 eral population and enjoy the same liberty as do the unaf- 
 fected citizens. In other places efforts are employed to sepa- 
 rate them from the people at large by systems of segrega- 
 tion, as in colonies, or upon farms, or in asylums. The Eng- 
 
154 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 lish Leprosy Commission considers compulsory segregation 
 as unnecessary, while the unanimous opinion of the First In- 
 ternational Scientific Leprosy Conference (Berlin, October, 
 1897) was : " That segregation is the best means of prevent- 
 ing the spread of leprosy, and that for all countries in which 
 the disease exists (endemically) it is further recommended 
 that compulsory notification, medical supervision, and isola- 
 tion of individual cases be enforced." 
 
 Notwithstanding the fact that obligatory segregation or 
 isolation has never been practised in Norway, the disease has, 
 through intelligent management, been markedly diminished. 
 His observations in Norway lead Hansen to the opinion that 
 the spread of leprosy may be very much checked by scrupu- 
 lous cleanliness, both personal and domestic, on the part of 
 the patient ; by the observation of this the patient can in 
 large measure isolate himself in his own home. 
 
 Where destitute lepers are present in number, it becomes 
 the duty of the State to provide for their care in properly 
 equipped isolation hospitals or asylums, or in carefully regu- 
 lated colonies. According to the demands of the case, isola- 
 tion under these circumstances may be partial or absolute. 
 
 At the Berlin Conference attention was also attracted to 
 the importance of regarding the diseased tissue as a source 
 of infection to others, and with this in view it was recom- 
 mended that the dissemination of infective materials from 
 these tissues be prevented by the use of antiseptic ointments, 
 bandages, and dressings. 
 
 If in countries where the disease is endemic, the public be 
 educated to the full appreciation of its dangers, as Hansen 
 has taken great pains to do in Norway, isolation and segre- 
 gation may be forced upon the lepers without legal aid^that 
 is to say, by refusing to employ them, by refusing to assist 
 them, by denying their admission to public buildings, convey- 
 ances, etc. — they are finally driven for self-preservation to 
 separate themselves from the general public. 
 
 Lepers should, if possible, be induced to live apart from 
 the healthy population, preferably colonized in some agricul- 
 tural district. Such colonics should be provided with hos- 
 
TETANUS. 155 
 
 pitals or lazarettos properly equipped for the management 
 and study of such cases as require medical aid. Where seg- 
 regation of lepers has been insisted upon, the number of cases 
 in the locality has almost uniformly decreased. 
 
 As in the vast majority of cases the disease is apparently 
 transmitted by heredity, the marriage of lepers should always 
 be discouraged, and, if possible, be prevented. 
 
 They should be prohibited from following such occupa- 
 tions as that of barber, laundryman, provisioner, etc., that 
 bring them in more or less immediate contact with healthy 
 persons. 
 
 TETANUS. 
 
 {^Lock-jaiv.^ 
 
 Definition, Cause, etc. — An acute infectious disease 
 .caused by a specific micro-organism — bacillus tetani — and 
 characterized by frequent and long-continued spasm of the 
 voluntary muscles. 
 
 The causative agent — bacillus tetani — was discovered by 
 Nicolaier in 1 884, through the introduction of garden earth 
 beneath the skin of mice. He demonstrated that the pus or 
 other exudate found at the site of operation in the tetanic 
 mice was capable of inducing the disease in other animals 
 into which it might be introduced. The bacillus of tetanus 
 was not isolated in pure culture until later (1889), when 
 Kitasato separated it by special anaerobic methods from the 
 other forms with which it is usually associated, and proved 
 its causal relation to the disease, by the inoculation of sus- 
 ceptible animals with the pure cultures. 
 
 The bacillus of tetanus has been detected in the soil of 
 many localities. It is pretty generally distributed in the 
 upper layers of the earth, though in some places it is much 
 more numerous than in others. It can usually be demon- 
 strated in the soil of gardens that are fertilized with animal 
 manure. These facts explain the occasional onset of tetanus 
 
156 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 after wounds into which earth has gained access, such for 
 instance as punctured or lacerated wounds of the feet and 
 hands by old rusty nails, wooden splinters ; crushed wounds 
 from the wheels of wagons, carts, etc. 
 
 It is a motile, spore-forming, anaerobic bacillus that pos- 
 sesses the morphological peculiarity, when in the spore-stage, 
 the only condition by which it is recognizable microscopically, 
 of presenting the appearance of a small pin — /. c, the oval, 
 glistening, unstained spore occupies one end of the rod, and 
 serves as the head, while the slender stained body of the 
 bacillus forms the rest of the pin-shaped structure (Fig. 18). 
 
 Fig. 18. — Bacillus tetani from artificial culture. 
 
 The spores of bacillus tetani are very tenacious of life. 
 They are not destroyed by drying, even by absolute drying 
 in the dessicator, for months. They are killed in five min- 
 utes by steam at 100° C, but they resist moist heat at 80° 
 C. for one hour. They are not destroyed by immersion in 5 
 per cent, carbolic acid for ten hours, though they are killed 
 in fifteen hours by this treatment. 
 
 The vegetative form of the organism as studied in pure 
 culture is found to be by no means so resistant to detrimental 
 agencies as are the spores. 
 
 As it is an obligate anaerobe (not growing in the presence 
 
TETANUS. 157 
 
 of free oxygen), it requires special methods for its isolation 
 and cultivation. (See works on Bacteriology.) 
 
 After the subcutaneous inoculation of mice, rabbits, and 
 guinea-pigs with pure cultures, with particles of earth, with 
 secretions from a wound, or with bits of tissue containing 
 this organism, typical tetanus supervenes in from twenty-four 
 to thirty-six hours, and usually ends fatally in from two to 
 three days. As a rule, the spasms begin in the muscles 
 nearest the site of inoculation. In animals suffering from 
 experimentally induced tetanus the slightest tap on the cage 
 or the least disturbance of the body usually suffices to bring 
 on the characteristic muscular contractions. At autopsy one 
 may find either an area of suppuration or very slight, often 
 hardly distinguishable, inflammatory reaction at the point of 
 operation. The suppuration is not the result of pathogenic 
 activities of the tetanus bacilli, but rather of other, pyogenic 
 organisms, that the earth contained. In many cases the 
 bacilli may be detected microscopically and isolated by cul- 
 ture methods from the tissues at the site of inoculation, but 
 almost as often they are missed. 
 
 From the experimental standpoint, this disease is of much 
 historic interest, since it was while investigating tetanus that 
 Behring and Kitasato made the observation from which have 
 been elaborated the principles underlying the employment of 
 the serum of artificially immunized animals for the cure of 
 disease. 
 
 Geographical Distribution, Season, Race.— In both 
 the eastern and western hemispheres tetanus is much more 
 frequent in tropical than in the temperate and colder climates ; 
 though it often occurs in subtropical localities, as, for instance, 
 in the southern part of the United States, where, according 
 to all accounts, it is at times a very formidable disease. 
 Among the inhabitants of certain of the Antilles islands, in 
 Guiana, Brazil, and Peru, tetanus now and again occurs with 
 such violence as almost to assume an epidemic character. 
 
 The race that conspicuously suffers from tetanus is the 
 negro. Whether this is due to a particular vulnerability of the 
 black man to this variety of infection or not it is difficult to 
 
158 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 say ; but certainly his preference for hot climates, his social 
 condition, his careless personal habits, his insufficient cloth- 
 ing, and his constant exposure to the character of injuries 
 that are known to be most often followed by tetanus, are im- 
 portant factors in favoring the frequent occurrence of the dis- 
 ease among this people. The disease is more common in 
 spring and summer than at other seasons of the year. Its 
 onset, according to many writers, seems to be especially fav- 
 ored by sudden and extreme fluctuations in the weather, as 
 by cold nights following upon hot days, by the sudden occur- 
 rence of cold rains after a hot spell, and by cold, moist winds 
 during the summer months. 
 
 Indeed, practically all writers on this disease, prior to the 
 discovery of its bacterial origin, regarded atmospheric influ- 
 ences as the most important etiological factor. Nowadays 
 'little weight is given to this supposed predisposing influence 
 of meteorological and climatic conditions. Special telluric 
 conditions do not appear essential to the existence of the spe- 
 cific virus. 
 
 The majority of domestic animals are susceptible to tetanus, 
 and instances are recorded in which the disease was appar- 
 ently endemic in particular stables. The occurrence of tet- 
 anus among grooms and others in close association with 
 horses and cattle is probably due to infection of insignificant 
 wounds with soil containing the tetanus bacillus, and not to 
 their association, per se, with animals, as has been suggested 
 b)' some who believe in the animal origin of the tetanus 
 virus. 
 
 Dissemination, Mode of Infection. — Though an in- 
 fectious disease, tetanus is not communicable from person to 
 person, save by direct inoculation. The disease is contracted 
 through infection of wounds with matters containing bacillus 
 tctani or its spores. The commonest of such wounds are 
 those occurring about the soles of the feet and the palms of 
 the hands, though the disease may result, and has resulted, 
 from the infection of wounds in other parts of the body. 
 Frequently the wound is so trivial at the time of its reception 
 as not to attract attention, and no notice is paid to it until the 
 
TETANUS. 159 
 
 remote effect — general tetanus — has set in. Often no history 
 of injury in cases of tetanus can be obtained, either upon ex- 
 amination of the body or by questions put to the patient ; 
 these cases are generally classed as " idiopathic tetanus," 
 though it is difficult to conceive that the disease can orig- 
 inate without an antecedent trauma that has served as the 
 portal of entry for the specific micro-organism ; or that it can 
 be perfectly simulated, and prove fatal, by some other malady 
 etiologically distinct. 
 
 Among the negroes in the tropics and in the southern 
 States tetanus in new-born infants (tetanus or trismus neon- 
 atorum, as it is called) often occurs with alarming frequency. 
 It is practically always due to direct infection of the navel 
 through want of cleanliness and general carelessness in man- 
 agement. In the southern States the deaths from this cause 
 among negro infants have been reckoned at from 3 to 4 per 
 cent, of the total mortality from all causes. At times in 
 Jamaica 20 to 25 per cent, of all negro infants born die of 
 trismus neonatorum. 
 
 Prophylaxis. — The prophylactic measures against tetanus 
 include those generally employed against wound-infection. In 
 addition there should be proper covering for the feet, for 
 the disease more often results from injury to the bare or im- 
 perfectly shod and dirty feet by nails, splinters of wood, and 
 the like, than from any other cause. Similar injuries to the 
 hands often result in tetanus. In short, all punctured or lac- 
 erated wounds of the extremities, into which particles of earth 
 are likely to have entered, should be regarded as possible 
 sites of this particular infection. They should be carefully 
 cleansed and otherwise cared for, no matter how insignificant 
 and trivial they may appear at the time of their reception. 
 The discharges and dressings from the wounds of tetanus 
 patients contain the specific infective organism, and they 
 should be considered as dangerous. Dressings should be 
 burned. 
 
l6o HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 ANTHRAX, 
 
 Definition, Cause, etc. — An acute specific disease, due 
 to infection by dacilhis antJiracis. 
 
 As a disease of animals, especially of herbivora, it is prob- 
 able that anthrax has been known since very early times. It 
 is one of the most widely distributed pests, both geographi- 
 cally and zoologically, of which we possess any knowledge. 
 A trustworthy and complete conception of its cause, pathol- 
 ogy, modes of perpetuation, dissemination, and infection, 
 however, has been rendered possible only through the appli- 
 cation of precise methods of modern investigation. The evo- 
 lution of our real knowledge of anthrax began with the dis- 
 cover),^ of rod-shaped bodies in the blood of animals dead of 
 the disease by Pollender in 1855, and the demonstration that 
 these bodies stand in causal relation to the malady by Davaine 
 in 1863. 
 
 Man, as well as practically all domestic animals, is suscep- 
 tible to anthrax. The bacillus of anthrax is a large, rod- 
 shaped organism, with square ends that may readily be 
 detected microscopically, by the ordinary methods of stain- 
 ing, in the blood and internal organs of animals dead of the 
 disease, and often in the lesions and secretions from the site 
 of infection in man. In the blood of animals it is seen as 
 single rods or as from 2 to 4 individual rods joined together 
 (Fig. 19) ; it rarely occurs as longer threads, under these cir- 
 cumstances. Though readily forming spores under the con- 
 ditions of artificial cultivation, spores are not found during 
 life in the body of the infected animal. Bacillus aiithracis is 
 not motile. 
 
 It can easily be isolated by the usual culture methods, as 
 it grows readily and lu.xuriantly on all nutrient media in 
 ordinary u.se for bacteriological purpo.ses. 
 
 Neither its morphology nor its appearance in cultures is 
 alone sufficient for its identification, since in each of the.se 
 respects it is closely simulated by one or two saprophytic 
 forms of bacteria that are commonly present in the sDil. It 
 can be recognized with certainty by its effects upon animals. 
 
ANTHRAX. l6l 
 
 White mice, common house-mice, guinea-pigs, and rabbits are 
 markedly susceptible to infection by it, and usually the least 
 particle of a typical culture of bacillus anth^acis, when de- 
 posited beneath the skin of any of these animals, suffices to 
 induce a septicemia that ends fatally in from eighteen to 
 thirty-six hours. The autopsy reveals a wide-spread area 
 of edema about the site of inoculation (this is most common 
 in rabbits) and the general distribution of bacilli throughout 
 
 Fig. 19. — Bacillus anthracis in blood. 
 
 this area, as well as their presence in the blood and internal 
 viscera. 
 
 Bacillus antliracis is markedly tenacious of life, particularly 
 when in the spore stage — a state into which it enters as soon 
 as conditions arise that are not conducive to its normal mul- 
 tiplication as vegetative cells. The spores of this organism 
 may be dried for years at ordinary temperatures — i. c, 
 between 12° C. and 40° C. — without losing either vitality of 
 virulence. They withstand such detrimental influences as 
 heat, cold, the antagonism of other bacteria, etc., to a remark- 
 able degree. They germinate, other conditions being favor- 
 able, at from 12° C. to 38° C. They resist the temperature 
 of streaming steam (100° C), at times, for as long as twelve 
 minutes (v. Esmarch), though, as a rule, this temperature is 
 destructive to them in from two to four minutes. Dried 
 11 
 
1 62 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 spores are more resistant to heat than are those in a moist 
 condition. They are not destroyed by corrosive sublimate in 
 I : lOOO solution in less than twenty-four hours, and they 
 have been shown to resist the action of 5 per cent, carbolic 
 acid for as long as thirty-seven days. The vegetative forms 
 of this organism, when no spores are present, are killed in 
 ten minutes by 54° C. 
 
 From what has been said it is manifest that articles con- 
 taminated by spore-containing matters from about animals or 
 man infected with anthrax, need to be most carefully manipu- 
 lated in order to eliminate completely the possibility of their 
 further disseminating the disease. Herbivora, omnivora, and 
 certain carnivora are susceptible to anthrax, the degree of 
 susceptibility being greatest in herbivora and least in car- 
 nivora. White rats are but slightly, if at all, susceptible ; 
 many birds and, particularly, all cold-blooded animals are 
 insusceptible. 
 
 As occurring in animals, anthrax is a septicemia — /. c, the 
 blood is the principal field of multiplication of the organisms. 
 Animals infected with anthrax frequently suffer from hemor- 
 rhages from the bowels ; the blood thus lost contains the 
 bacilli in greater or smaller numbers. 
 
 As discharged from the body the specific organism is not 
 in the spore-stage, but it readily enters this stage under the 
 conditions of the soil that are unfavorable to its further vege- 
 tation. In this manner the soil over which such cattle are 
 grazing becomes infected and serves as a means of perpetuat- 
 ing the disease among the herd and of disseminating it to 
 other cattle that may subsequently be pastured on the same 
 land. Infection commonly occurs through tiny scratches 
 and wounds of the lips, tongue, and cheeks, received by the 
 cattle while grazing over the infected focus. It is likely that 
 the disease is sometimes carried by insects, such as flies, lice, 
 ticks, etc. 
 
 Anthrax in Man. — Anthrax is a comparatively rare dis- 
 ease in man ; and man is apparently less susceptible to it 
 than are most of the domestic animals. 
 
 It never occurs spontaneous!}-, but is always the result of 
 
ANTHRAX. 163 
 
 direct infection. It is most frequent in grooms, tanners, 
 shepherds, butchers, herdsmen in general, cattle-dealers, and 
 in those whose occupation brings them in close contact with 
 raw animal-products. 
 
 In man the disease occurs as " external anthrax," due to 
 the infection of surface-wounds by the specific morbific agent, 
 and as " internal anthrax," due to the swallowing or inspira- 
 tion of dust contaminated with the spores of the organism. 
 
 In external anthrax (malignant pustule) resulting from 
 infected wounds, usually of the face, neck, hands, or forearms, 
 the disease may run its course as a localized carbuncle that 
 heals slowly, without constitutional symptoms, and sometimes 
 with but slight pain. Or, as is more often the case, the local 
 lesion becomes surrounded by a progressive zone of edema, 
 the lymphatics become involved, and symptoms indicative of 
 general infection make themselves manifest. Secondary 
 lesions of the stomach and intestines may occasion bloody 
 vomiting or diarrhea ; those of the brain are evidenced by 
 cerebral disturbance. A rapid extension of the edema from 
 a local lesion of the face or neck to the larynx or thoracic 
 cavity results in distressing dyspepsia, and at times proves 
 fatal. Death may ensue from collapse, due to general infec- 
 tion, or from either of the secondary manifestations men- 
 tioned above. By both microscopical and culture methods 
 the specific bacillus may usually be detected at the site of 
 infection, and in the organs in those cases that prove fatal. 
 In cases that recover, the bacilli are often missed, or if found 
 microscopically they present the appearance of degeneration. 
 Very frequently it is impossible to cultivate them from the 
 local lesion in such cases, unless the effort be made very 
 early in the onset of the disease ; and then mixed cultures 
 — i. e., cultures of anthrax bacilli together with pyogenic 
 bacteria and ordinary saprophytic varieties — are usually 
 obtained. 
 
 A rarer manifestation of the disease is that known as ina- 
 lignant anthrax edema. In this form there is no primary 
 papule or vesicles ; there is extensive edema of the eyelids, 
 face, neck, hands, or arm. The edema may be wide-spread 
 
164 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 and result in gangrene of the affected parts. It may follow 
 the constitutional symptoms. These cases are frequently 
 fatal. 
 
 Internal anthrax assumes two forms — viz., the intestinal, 
 known as " mycosis intestinalis," and that which manifests 
 itself more especially through pulmonary symptoms (" wool- 
 sorter's disease "). The former occurs through the ingestion 
 of meat or milk from diseased animals, and through the swal- 
 lowing of infected dust; while the latter is seen among 
 workers in infected hair, hides, and wools, resulting most 
 likely from the inhalation of dust containing anthrax spores. 
 The wools that are especially looked upon with suspicion, 
 from this standpoint, are those imported from Russia and 
 South America. 
 
 Prophylaxis. — The most trustworthy modes of extermi- 
 nating the disease are cremation and burial of the carcasses 
 
 o 
 
 as soon as possible after death. The preferable method is the 
 latter, as the body can be buried whole, and there is thus less 
 liability of further pollution of the soil with blood and other 
 fluids from the tissues ; while for cremation or disinfection by 
 heat or chemicals the animal usually needs to be cut into 
 pieces of convenient size to be handled, a process that results 
 in the spreading about of the infective agents through the 
 blood and fluids that escape during manipulation. The body 
 should be buried nnatt, not less than six feet below the sur- 
 face. After this procedure the vegetative forms of the bacilli 
 in the blood and tissues are quickly destroyed through the 
 antagonistic influences that accompany decomposition of the 
 carcass in the ground. They do not enter the spore-stage, for 
 the reason that under the conditions of burial they are with- 
 out the free access to oxygen that is all-essential to the proc- 
 ess of spore-formation. 
 
 Of greater importance in preventing the occurrence of an- 
 thrax among herds is the method of preventive vaccination. 
 Though all authorities are not agreed as to the practical 
 benefits of this method, the results reported by certain reli- 
 able investigators are sufficient to warrant its being given a 
 fair trial. Thus, for instance, Chamberlain reports as a re- 
 
ANTHRAX. 165 
 
 suit of experience with the method of preventive vaccination 
 in France, for the twelve years ending with 1893, that the 
 mortality from anthrax among 3,296,000 vaccinated sheep 
 was 0.96 per cent., whereas prior to the introduction of vac- 
 cination it had been 10 per cent. During the same period 
 438,000 head of horned cattle (bovines) were vaccinated and 
 0.34 per cent, died of anthrax, the previous mortality from 
 this disease among these animals having been 5 per cent. 
 Favorable results have likewise been obtained in Hungary and 
 in Russia. 
 
 The method has been practised on a smaller scale with 
 satisfaction at the Agricultural Experiment Station at New- 
 ark, Del., in the neighboring counties of which anthrax has 
 been mildly endemic for the past two or three years. The 
 disease has never prevailed in this country to any great ex- 
 tent ; it is, in fact, considered to be rare here. It is very com- 
 mon in South America, France, Russia, and Hungary. The 
 method of preventive vaccination aims to induce a mild form 
 of the disease by inoculating the animals with attenuated cul- 
 tures of anthrax bacilli. Animals that have recovered from 
 this mild form of anthrax are for a time, sufficiently long for 
 all practical purposes, immune from the disease. 
 
 If upon slaughtering an animal it is found to have had an- 
 thrax, all spilled blood and all soiled articles should be at 
 once disinfected. Over the blood that is spilled milk of lime 
 (fluid whitewash) or 5 per cent, solution of chlorid of lime 
 should be spread. Instruments should be boiled and the 
 hands disinfected in 3 per cent, carbolic acid and washed thor- 
 oughly with soap and water. 
 
 The flesh of anthrax animals should never be used as food, 
 even in the earliest stages of the disease. It should be buried 
 or burned, or destroyed by quick-lime. 
 
 All hair and wool should be disinfected by steam. If this 
 be impracticable it should be sorted moist, preferably moist- 
 ened with a mild disinfectant. The ceiling, walls, and floors 
 of sorting rooms should be frequently washed with strong 
 carbolic-acid solution ; the walls should be whitewashed from 
 time to time. These rooms should be well ventilated, and 
 
l66 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 when the wools cannot be sorted in a moist state, this should 
 be done under hoods provided with specially strong outward 
 draughts for carrying off the dust. 
 
 Workmen should be impressed with the importance of per- 
 sonal cleanliness, daily bathing, the frequent dusting and 
 washing of their clothing, and particularly the careful wash- 
 ing of the hands before partaking of food. The local secre- 
 tions from malignant pustule, and the sputum and stools of 
 persons suffering from internal anthrax are infectious, and 
 should be disinfected. All bandages should be burned, and 
 all instruments disinfected. 
 
 GLANDERS. 
 
 Definition, Cause, etc. — An infectious disease of horses, 
 mules, and asses, communicable to man, and caused by a spe- 
 cific micro-organism — viz., bacillus mallei. 
 
 The disease occurs in all countries and at all seasons. It 
 attracts more attention in France, Belgium, Holland, Austria, 
 Russia, and Germany than elsewhere. In both men and 
 horses it is remarkable for its fatality. 
 
 The disease is known as glanders when the principal seat 
 of its activity is the mucous membrane of the nostrils, and as 
 farcy when it is confined to the subcutaneous lymphatics, 
 though both expressions may occur simultaneously. Gland- 
 ers is characterized by the occurrence of small gray nodules 
 (infectious granulomata) upon the mucous membrane of the 
 upper air-passages, particularly of the nose. These coalesce 
 and ulcerate, and there results a profuse mucopurulent dis- 
 charge from the nostrils. Farcy is characterized by the 
 formation of etiologically similar granulomata under the 
 skin, along the course of the lymphatics, and in the lymphatic 
 glands. These proceed, as a rule, to abscess-formation and 
 suppuration. 
 
 Both glanders and farcy occur in man ; the former from 
 
GLANDERS. 1 6/ 
 
 the deposition of the specific causative agent upon the mu- 
 cous membrane of the nares, the latter from its introduction 
 into wounds of the skin. 
 
 In man glanders may assume either the acute or chronic 
 form. Acute glanders is fatal, as a rule, in from one to two 
 weeks ; chronic glanders may exist for months without of 
 necessity proving fatal. 
 
 In acute farcy in man the lymphatics are conspicuously in- 
 volved, presenting along their course the cloudy nodular 
 swellings known as " farcy buds." The local site of infection 
 is acutely inflamed, presenting the characters of an acute 
 phlegmon. The mortality from acute farcy is high. Death 
 results in from two to three weeks. 
 
 Chronic farcy in man is characterized by local abscesses in 
 the extremities. There is little lymphatic involvement. 
 These abscesses break down and ulcerate. The disease often 
 lasts for months, during which time there is frequent recur- 
 rence of the local suppurations. It is not necessarily fatal, 
 unless acute glanders is engrafted upon it or pyemia super- 
 venes. 
 
 The cause of the disease, bacillus mallei, as it is called, was 
 discovered by Loffler and Schiitz in 1882. It is a short, 
 straight or slightly bent, pointed, irregularly staining, non- 
 motile, non-spore-producing rod (Fig. 20) that is found in the 
 secretions, in the pus, and in the characteristic granulomata 
 of animals and man affected with the disease. It can be iso- 
 lated in culture on the ordinary nutrient media, though gela- 
 tin is less adapted to this purpose than are the other media 
 that can be kept at a higher temperature. Its growth is not 
 especially characteristic, though on potato its development is 
 simulated by but few, if any, other organisms. Here it grows 
 as a moist, brownish, amber- or honey-colored layer that grad- 
 ually assumes a deeper color as development proceeds. 
 
 It is destroyed in five minutes by a temperature of 55° C. ; 
 in five minutes by 5 per cent, carbolic acid and in two min- 
 utes by I : 1000 corrosive sublimate. It is killed in a few 
 days by drying. It has been known to resist putrefaction 
 for a long time. Boiling water instantly kills them — a prac- 
 
l68 HYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 tical point of value to be remembered in cleaning up the 
 stalls of animals or the beds of men affected with the disease. 
 Horses, 'asses, mules, lions, tigers, field-mice, guinea-pigs, and 
 cats are susceptible to glanders. Rabbits are but slightly 
 susceptible, and dogs and sheep less so. White mice, com- 
 mon gray mice, bovines, hogs, and rats are insusceptible. 
 Man, as said, is susceptible to this variety of infection. 
 
 Beyond the appearance of the characteristic granulomata 
 in the spleen, field-mice dead after subcutaneous inoculation 
 with this organism present none of the lesions characteristic 
 of the disease in the horse. The spleen is enlarged, and often 
 
 Fig. 20. — Bacillus mallei from artificial culture. 
 
 quite covered with tiny gray nodules having something the 
 appearance of miliary tubercles. The pathological lesions 
 and clinical course of the disease after subcutaneous inocula- 
 tion of guinea-pigs are much more typical. The animal lives 
 for from six to ten weeks, during which time the joints of the 
 extremities become infiltrated, swollen, and stiff; the testicles 
 become very much distended, often suppurating and break- 
 ing til rough the skin ; and there is the characteristic muco- 
 purulent discharge from the nostrils, secondary to ulceration 
 of the nasal mucous membrane. The lungs, kidneys, liver, 
 and spleen, especiall}' the last, usually contain the minute. 
 
GLANDERS. 1 69 
 
 gray nodules — the glanders granulomata. The bacillus of 
 glanders may be recovered from all the lesions. 
 
 The most trustworthy diagnostic test for glanders is that 
 recommended by Strauss. It consists in the introduction of 
 a bit of the suspected culture or tissue into the peritoneum 
 of a male guinea-pig. If the material used be from a case of 
 glanders the animal's testicles begin to swell in about thirty 
 hours, the skin over them becomes red and shining, and 
 desquamation occurs ; evidence of incipient suppuration is 
 manifest, and there results a purulent orchitis that ultimately 
 breaks through the skin. 
 
 The modern method used by most progressive veterinarians 
 for the diagnosis of incipient glanders in horses is by the use 
 of mallein. Mallein is the filtered product of growth of the 
 glanders bacillus in fluid media. When injected into animals 
 affected with the disease, even in so early a stage as to defy 
 recognition by other methods of inspection, there results a 
 striking constitutional reaction that is signalized by sudden 
 but temporary rise of temperature ; whereas a similar injec- 
 tion is sustained by healthy animals, or those not affected 
 with glanders, without such a result. 
 
 Modes of Dissemination, Portals of Infection. — 
 Glanders is commonly disseminated among animals through 
 direct contact between the healthy and diseased, the source 
 of infection being in most instances the discharges from the 
 muzzle. It may be carried by flies, hce, ticks, and similar 
 insects. Farcy may result from the extension of the disease 
 from its primary site in the nose, along the lymphatics ; or it 
 may result primarily from infection of wounds of the hide. 
 
 In man the disease is the result of direct infection, glanders 
 resulting from the deposition of infective matters upon the 
 mucous membrane of the upper air-passages, and farcy from 
 the infection of wounds of the skin. 
 
 In the ordinary sense of the word, the disease is not con- 
 tagious, though it is not improbable that the air about the 
 glanderous horse that is snorting or coughing contains the 
 virus, and may cause the isease if inspired. 
 
 In man the disease is most frequently encountered in 
 
IJO HYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 grooms, horse-dealers, and others coming in close association 
 with horses, mules, and asses. 
 
 Prophylaxis. — In neighborhoods that are free from the 
 disease, all imported horses, mules, and donkeys should be 
 quarantined until carefully inspected by a competent veterin- 
 ary surgeon. All animals suffering from the disease should 
 be killed. They should never be permitted to mingle in any 
 way with healthy animals, or even kept in close proximity 
 to them, after the diagnosis is established. Attendants who 
 have been in charge of the diseased animals should not be 
 permitted to handle the healthy ones until after thorough 
 cleansing and disinfection of their clothing and hands. 
 
 Attendants should look with suspicion upon all horses 
 having a discharge from the nose or corded nodules under 
 the skin. They should guard carefully against infecting abra- 
 sions of the hands, however slight they may seem, with dis- 
 charges from diseased horses. 
 
 Bandages, dressings, and instruments that have been used 
 about animals or man affected with glanders are capable of 
 carrying the infection, unless rendered harmless by thorough 
 disinfection. 
 
 The stalls from which glanderous animals have been re- 
 moved should be thoroughly cleansed with boiling water ; 
 the scrapings and sweepings should be scalded and burned. 
 The droppings from such animals should be scalded or 
 burned. The refuse of fodder should be scalded or burned. 
 
 The harness, particularly the bit, should be either thor- 
 oughly scalded, or soaked in 5 per cent, carbolic acid for a 
 few hours, after which it should be scrubbed with soap and 
 hot water, and dried before being used on a healthy animal. 
 
 The carcasses of dead animals should be deeply buried or 
 burned. 
 
ACTINOMYCOSIS. 171 
 
 ACTINOMYCOSIS. 
 
 Definition, Cause, etc. — A chronic infectious disease of 
 cattle and man that results from the development within the 
 tissues of the actinoinyces or ray fungus. 
 
 Pathologically, the disease is characterized by the develop- 
 ment in the tissues in which the fungus is growing — most 
 frequently those of the tongue or lower jaw — of granuloma- 
 tous masses that in some particulars suggest the tuberculous, 
 in others the osteosarcomatous processes. In the more 
 rapidly growing of these tumors suppuration, resulting in 
 cavities and fistulous formations, may occur. 
 
 If the pus from a case of actinomycosis be spread upon a 
 glass slide or allowed to flow down the inside of a test-tube, 
 it will be seen by transmitted light to contain numerous small, 
 white, yellowish, yellowish-green, or brownish points, easily 
 discoverable to the naked eye and having somewhat the 
 appearance of fine grains of sulphur or sand. If these be 
 picked out, gently squeezed between a slide and cover-slip, 
 and examined with a moderate power of the microscope, they 
 will be found to consist of a felt-Hke mycelium of a roughly 
 rosette shape. At the center the mass is coarsely granular 
 and presents numerous oval and spherical spore- or coccus- 
 like structures. About this center is a tolerably broad, 
 irregular zone of straight, curved, and branched pear- or 
 club-shaped radii. 
 
 From man these fungous tufts give the sensation, when 
 squeezed under the cover-slip, of small particles of tallow or 
 fatty tissue ; whereas from animals they feel gritty, due to the 
 deposition of lime-salts. 
 
 Staining is employed only for the detection of certain 
 minute structural details that are not necessary for diagnosis. 
 In unstained preparations the appearance of the tufts is char- 
 acteristic. If the structure be obscured by a deposit of cal- 
 careous matter, this may readily be dissolved away with 
 dilute acetic acid, without injury to the structure of the 
 fungfus. 
 
172 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 It can be cultiv-ated on practically all the ordinary nutrient 
 media, especially glycerin agar-agar, coagulated blood-serum, 
 and sterilized moistened bread-crumbs. In cultures the branch- 
 ing mycelia and the round or oval coccus- or spore-like bodies 
 are formed, but the club-shaped bodies seen in the pus are 
 less common, though they do occasionally present under 
 these circumstances. 
 
 Notwithstanding the fact that several trustworthy investi- 
 gators have reported positive results from the inoculation of 
 animals with this fungus, Bostrom, who has contributed so 
 liberally to our knowledge of the subject, still doubts that 
 the disease has ever been really reproduced in that way. He 
 claims that the tumefactions observed in the cases reported 
 as successful were not due to a multiplication of the fungus, 
 but \vere simply non-progressive points of proliferated tissue, 
 by which the fungous masses used for inoculation have been 
 encapsulated. The proof of its transmissibility by inocula- 
 tion is as yet incomplete. The actinomyces fungus is a 
 streptothrix. 
 
 Actinomycosis occurs in bovines, horses, and hogs. Its 
 most common seat of development is the tongue and adjacent 
 tissues of the jaws, particularly the lower jaw. It may occur 
 in the lips, cheeks, palate, pharynx, nose, larynx, trachea, 
 lungs, skin, and subcutaneous tissues. 
 
 From the frequency of its occurrence in the tongue and 
 jaws, and from the induration, tumefaction, and stiffening 
 that it occasions it is popularly spoken of as " lump-jaw," or 
 " lumpy jaw," and " wooden tongue." It attacks cattle of all 
 ages, and is usually considered to be incurable. 
 
 In man actinomycosis is a rare disea.se. When occurring 
 it is most frequently seen as a disea.se of the lower jaw. The 
 tumor rarely begins in the bone itself, but usually at its 
 periphery, manifesting itself as a lum]) in the submaxillary, 
 submental, or pretracheal region. Metastases from the pri- 
 mary growth are not uncommon. The disease may occur in 
 the lungs, from inhalation of the fungus, resulting in pneu- 
 monic patches, suppuration, hemorrhage, and cavity-forma- 
 tion. The sputum of such cases contains the fungus. Clin- 
 
A C TINOM YCOSIS. 1 7 3 
 
 ically, and in certain anatomical features, these cases are very 
 suggestive of chronic pulmonary tuberculosis. 
 
 Invasion of the intestinal tract may also occur in man. In 
 this expression of the disease small nodules of about the size 
 of a pea are seen in the mucous membrane and submucous 
 tissues of the gut. These soften, ulcerate, and either heal or, 
 
 Fig. 21. — Actinomyces fungus (" ray fungus") ; left, as seen in tissues under low 
 magnifying power ; right, a fungus mass examined fresh under higher mag- 
 nifying power. 
 
 as is more commonly the case, perforate into the peritoneum, 
 bladder, or through the abdominal wall. 
 
 Dissemination, Portals of Infection. — There is no 
 positive evidence that the disease is transmitted from animal 
 to animal, or from animal to man, or vice versa. It seems 
 probable that both man and animals receive the virus from 
 the same external source. 
 
 The belief is that the fungus is a parasite upon certain 
 cereals, and that it gains access to the animal through 
 wounds of the buccal mucous membranes, through abrasions 
 of the skin, or by way of carious teeth. Barley is the grain 
 that is viewed with most suspicion. Infection occurs most 
 frequently, in all probability, during feeding, though some 
 believe it to occur occasionally through inspired dust and 
 through water containing the fungus or its spores. 
 
174 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 Prophylaxis. — Since the disease is not readily trans- 
 mitted from animal to animal, or animal to man, by either 
 ordinar}' contact or by inoculation ; and since nothing is 
 positively known of the fungus outside the animal body 
 (except in artificial culture), it is manifest that our knowledge 
 is too limited to permit of the formation of trustworthy and 
 rational prophylactic rules. 
 
 It is, of course, safer to regard subjects of the disease 
 as dangerous and to isolate them, therefore ; it is advisable 
 to burn, scald, or otherwise disinfect articles polluted with 
 the discharges from such animals or persons. 
 
 MADURA FOOT. 
 
 {Fungus Disease of India; Mycetoma.) 
 
 Because of the existence of certain points of resemblance 
 between actinomycosis and Madura foot, it is proper to sum- 
 marize the essential features of the latter disease at this 
 place. 
 
 Mycetoma, Madura foot, or fungus disease of India, as the 
 disease is called, is a chronic affection occurring in the foot, 
 and occasionally in the hand, that is found endemically in 
 many parts of India. It is not supposed to originate outside 
 of India, though cases of the disease have been observed in 
 Italy, Morocco, America, and elsewhere. In many instances 
 these were imported. 
 
 It is characterized by local tumefactions of the foot or 
 hand. It is usually found in the foot, and does not pass be- 
 yond the metatarsal articulation, though occasionally it is 
 seen to include the leg and even reach as high up as the 
 thigh. Anatomically this tumor in many respects sug- 
 gests that resulting from the invasion of the tissues by the 
 actinomyces fungus, though there is sufficient evidence to 
 ju.stify the opinion that the two diseases are etiologically 
 distinct. 
 
MADURA FOOT. 175 
 
 It originates in the toes or in the loose cellular tissues 
 about the dorsum of the foot. It gradually involves the 
 deeper structures, reaching quite to and affecting the bones. 
 Numerous sinuses, which discharge a stinking watery pus, 
 lead from the surface to the deeper structures. The affected 
 part is very much enlarged, hard, tense, and painful. It never 
 attacks both feet simultaneously. It is not communicable 
 from person to person, and is not apparently auto-infective. 
 
 The hand is very much less frequently attacked than the 
 foot. The agricultural classes are much more liable to it 
 than are other classes of the community. When fatal, death 
 results from marasmus. If the affected member be ampu- 
 tated sufficiently early, health is generally regained. 
 
 Ktiology. — Two expressions of the disease occur — 
 namely, the " white " and the " black " mycetoma. In both 
 infections the tumors are characterized by the presence of 
 numerous, minute granules about the size of a pin-head. In 
 the white mycetoma these granules are white or yellowish in 
 color ; in the black mycetoma they are dark-brown or at 
 times quite black in color. By microscopical and bacterio- 
 logical methods these granules are found to consist of fun- 
 goid masses. The white mycetoma has been closely studied 
 by Bristowe, Carter, Kanthack, Boyce and Surveyor, Adami, 
 and others, and there is a general agreement of opinion that 
 it is in many respects very like the actinomyces fungus. The 
 fungus isolated by Vincent from white mycetoma is described 
 by him as a mycetial streptothrix that grows readily at body- 
 temperature on nutrient media containing sugar and glycerin. 
 It develops especially well in vegetable infusions. It is not 
 pathogenic in animals. 
 
 From the black mycetoma a fungus has been isolated by 
 Bristowe, Hogg, Bassini, Kanthack, Boyce and Surveyor, 
 Wright, and others, whose morphology, color, and cultural 
 peculiarities distinguish it at once from that isolated from the 
 white form of the disease. It is, therefore, likely that there 
 are concerned in the production of this malady two distinct 
 fungi.^ The inoculation of animals with the fungus obtained 
 
 ^ An excellent description of the black mycetoma, as well as a review of 
 
176 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 from the black mycetoma was, as in the case of that from 
 the white mycetoma, negative in results. The two varieties 
 of fungi do not appear together in the same case. 
 
 The disease is believed to occur in man through the access 
 of the causative agents to wounds of the feet or hands. 
 
 It is very much more common among the Hindoos than 
 among the Europeans or Indo-Europeans. Not a single 
 case of the disease among Europeans or Indo-Europeans has 
 been observed in India during the past forty years (Hirsch). 
 It is most common between the ages of twenty and twenty- 
 five years. It is extremely rare in the very young and in 
 the very old. It is more common in males than in females. 
 
 SMALL-POX* 
 
 Definition, Cause, etc. — An acute, infectious, highly 
 contagious disease that is characterized by an eruption upon 
 the skin and exposed mucous surfaces. The eruption passes 
 through the papular, vesicular, and pustular stages in turn, 
 and finally heals under a scab. The disease is especially 
 communicable during the convalescent period, when des- 
 quamation is actively in progress. 
 
 Though several micro-organisms, both of bacterial and 
 protozoal nature, have been detected in the pathological 
 lesions of small-pox, none of them have been proven to 
 stand in causal relation to the disease. The cause of small- 
 pox is as yet undiscovered. 
 
 Historical. — According to the exhaustive researches of 
 Hirsch, the origin of the disease cannot definitely be made 
 out, though the earliest records of it are found in India and 
 Central Asia. The first medical literary contribution on 
 small-pox is that of Rogers in the tenth centuiy. Incon- 
 
 the literature on the subject, is given by Wriglit in the Joitnial of Experi- 
 mental Medicine, 1898, vol. iii., p. 421. The illustrations in this article are 
 of special merit. 
 
SMALL-POX. 177 
 
 testable records of the disease in Europe date from the elev- 
 enth and twelfth centuries. It was introduced into North 
 America by the Spaniards in the sixteenth century. 
 
 Small-pox has appeared among practically all peoples on 
 the globe, and still appears with varying degrees of severity, 
 more especially in localities where vaccination is not system- 
 atically practised. It attacks all ages, and is particularly 
 fatal during the early years of life. Osier states that 86 per 
 cent, of all deaths observed by him during the severe epi- 
 demic in Montreal in 1885 occurred in children under ten 
 years old. Males and females are affected with practically 
 equal frequency. Negro and other colored races seem to be 
 more susceptible than are whites. 
 
 Excessive fatality has been observed to follow the first ex- 
 posure of aboriginal races to this disease, such, for instance, 
 as that seen among the early settlers, American Indians, and 
 Mexicans after the importation of small-pox into this country 
 by the Spaniards in the sixteenth century. It is much more 
 prevalent during the cold than during the warm months of 
 the year in temperate climates. 
 
 Dissemination. — In the majority of cases the disease 
 appears to be directly transmitted from the sick to the well 
 through the air. Persons unprotected by vaccination appar- 
 ently contract the disease by simply breathing the air of the 
 room in which the patient is confined. There is no evidence 
 that the disease is transmitted by food or through wounds ; 
 neither is there any evidence to the contrary. Persons who 
 have been in contact with small-pox patients, all articles used 
 about the patient, such as body- and bed-clothing, eating- 
 utensils, carpets, furniture, letters, etc., and vehicles in which 
 the sick may have been transported, are capable of conveying 
 the contagion. 
 
 The period of highest infectivity is believed to be during 
 the stage of desquamation, when the morbific agent, of what- 
 soever nature it may be, is disseminated throughout the air 
 with the fine particles of epidermis that the patient sheds. 
 The disease is probably contagious sooner than this, but just 
 how soon is not definitely determined. 
 12 
 
1/8 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 Prophylaxis. — For the prevention and eradication of 
 small-pox s}'stematic (compulsory if need be) vaccination so 
 overshadows in importance all other means as to make it the 
 prophylactic measure /rt:r excellence against this pest. The 
 isolation of the patient, the disinfection or destruction by 
 burning of all clothing and other objects that have been in 
 contact with him, the disinfection of his room, the anointing 
 of his body with antiseptic oils during the dangerous stage 
 of desquamation, etc., are precautions never to be ignored in 
 efforts to pre\'ent the spread of the disease ; but they are as 
 naught in efficiency as compared with the successful vaccina- 
 tion of all those with whom the small-pox patient or con- 
 valescent is likely to be in association (see and compare 
 accompanying charts of Prussia and Austria, Charts 13 
 and 14. 
 
 To meet the demands of large centers of civilization in 
 which sporadic cases and mild outbreaks of small-pox are 
 from time to time occurring, there should be hospitals or 
 lazarettos especially equipped for the management of acute, 
 infectious diseases. These should be provided with proper 
 facilities for isolating the cases, for disinfecting the clothing, 
 and for frequent cleansing and disinfecting of the entire walls, 
 ceilings, floors, and furniture of the wards or separate rooms. 
 The personnel of such hospitals should comprise competent 
 physicians, well versed in the laws of preventive medicine, 
 and an adequate corps of nurses specially trained in the 
 management of infectious diseases, all of whom should have 
 been successfully vaccinated. Sporadic cases of small-pox 
 should be sent to such hospitals at the earliest possible mo- 
 ment after the diagnosis is established. Hospitals for this 
 purpose should be provided with special observation wards 
 in which doubtful cases may be placed until the true nature 
 of the disca.se is definitely made manifest. 
 
 For the welfare of the comnumity at large, too much 
 stress cannot be laid upon the importance of prom])t notifica- 
 tion of the existence of contagious di.sease. It is only 
 through tlie full co-operation of physicians in these matters 
 
SMALL-POX. 
 
 1 79 
 
 Chart 13. — Progress of small-pox in Prussia before and after the en- 
 forceme7it of general vaccination. Death-rate per 100,000 of popu- 
 lation, 1 8 46- 1 886. 
 
 
 10 
 03 
 
 ■* 
 
 
 r- 
 
 a' 
 
 ■ill 
 
 CO 
 
 
 (0 
 
 10 
 
 CO 
 
 t^oooc 
 
 IDlDino 
 
 [)«D(OiO(l 
 
 3(0(D!D(£ 
 CO 
 
 o>o c 
 
 =0- £ 
 
 
 CO 
 
 'J- 
 
 10 
 
 (D 
 
 oc 
 
 1^ 
 
 CD 
 
 0) 
 
 
 
 CO 
 
 1 
 
 a 
 
 OD 
 
 
 COCO 
 
 12 
 
 
 100 
 
 00 
 
 80 
 70 
 
 eo 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 100 
 
 00 
 
 so 
 
 70 
 GO 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 a 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 
 ^1 
 
 !e 
 
 rage - 
 
 i^.4S 
 
 
 
 
 
 
 
 
 
 A 
 
 vet 
 
 a 
 
 /< 
 
 i.si 
 
 
 
 
 
 
 
 
 
 
 
 "^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 :=5 
 
 
 
 
 
 
 
 
 
 
 
 
 
 40 
 so 
 so 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 ^ 
 
 
 
 t 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 30 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 a 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I 
 
 fll 
 
 
 
 
 
 ■ ' 1 
 
 — -- 
 
 -- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 : 
 
 1 
 
 1 
 
 ^ 
 
 
 
 
 1 
 
 1 
 
 ■ 
 
 I 
 
 
 
 1 
 
 1 
 
 1 
 
 
 
 
 
 
 ; 
 
 J.<—^. t^'= -. -^ -^V- c-.V. -■-.- -. T^h -y. :- -^ =, -, -^. -^ ud ct -s 
 
 § 
 
 
 
 Chart 14. — Progress of small-pox in Austria. No compulsory vacci- 
 nation tip to 1884. Death-rate per 100,000 of population. 
 
 100 
 90 
 so 
 70 
 eo 
 so 
 40 
 
 30 
 20 
 
 10 
 
 CO 
 
 
 ooc 
 
 no 
 
 f ID 
 
 ID 
 00 
 
 CM 
 ID 
 
 CO 
 ID 
 
 IDU 
 
 5(D 
 
 >1D 
 
 CO 
 
 ID 
 
 n 
 
 CD 
 ID 
 
 0, 
 
 ID 
 
 olJJ.!. 
 
 CD <C> (O tD(D 
 
 |C0 1 
 
 ID 
 
 CD 
 
 WIS} 
 
 CO 
 
 CD 
 CO 
 
 s 
 
 
 
 00 
 
 CM 
 
 CO Tt locor^ 
 CO 
 
 JO'.roiOIr: CN CO •+ ID 
 ■^r^cD°o|oojCDoaoo 
 
 CD 
 OD 
 00 
 
 100 
 
 00 
 
 so 
 
 70 
 
 eo 
 
 so 
 
 40 
 
 30 
 SO 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 [ A- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 n 1 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 H 
 
 1 ( i^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 ' Ih 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 jtlt'Tr 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 II 
 
 — 
 
 
 
 
 
 -. 
 
 
 - ■ T t T T 
 
 :::;:f 
 
 ~ 
 
 - 
 
 
 
 1 
 
 f 
 
 
 1 
 
 - 
 
 t 
 
 
 
 
 
 "■' 
 
 
 
 q 
 
 Ji|SlS|— ttS|c'jpp:y,Sj«|'N|Seiira'^|S;^S|':5S|^^ 
 
 S 
 
 Ci 
 
 i i|fp, 
 
 -=,.oSt«;,c5j2s|0 
 
 L 
 
 
 Charts 13 and 14 are after Schulz : Impfung, Impfgeschdft und Impftechnik, 
 
 Berlin, 1891. 
 
l8o HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 that the municipal health authorities are enabled to perform 
 the functions of their office properly. 
 
 VARICELLA 
 
 ( Chicken-pox. ) 
 
 Definition, Cause, etc. — An acute, specific, febrile, dis- 
 order that is characterized by a peculiar vesicular eruption 
 upon the skin. The cause is not known. It is rarely severe, 
 and is one of the common diseases of childhood ; it is espe- 
 cially seen in children under five years of age, though it may 
 occur in older persons. 
 
 It prevails in the autumnal months. It is seen both as 
 isolated cases and as epidemic outbreaks. It is not appar- 
 ently related etiologically to small-pox, and an attack of 
 chicken-pox in no way protects against small-pox, and vice 
 versa. Instances are recorded in which both diseases have 
 occurred in the same individual within a short time of each 
 other. 
 
 It is markedly contagious, but the channels through which 
 it is especially transmitted are not definitely determined. 
 The contagion appears to be air-borne, and also seems to be 
 capable of being carried by fomites. 
 
 Prophylaxis. — The disease is contagious from its onset 
 to its finish. The prophylactic measures that are adopted, 
 when adopted at all, consi-st in the isolation of the patient, 
 though, as a rule, the disease is regarded as so benign, and 
 as a disease through which children are of necessity liable to 
 pass, that few strict measures are adopted for the prevention 
 of its spread. 
 
 The complications, or rather the unusual manifestations, 
 of varicella are subjects more for works upon clinical medi- 
 cine than for sketches of this character. 
 
MEASLES. 151 
 
 MEASLES. 
 
 Definition, Cause, etc. — An acute febrile disorder char- 
 acterized by the occurrence of coiyza and an eruption upon 
 the skin of small red papules that ultimately coalesce into 
 irregularly round or crescentic blotches. 
 
 Measles is one of the most, if not the most, contagious of 
 the acute exanthemata. Its cause has not yet been deter- 
 mined. • 
 
 It is a disease of the first five years of childhood, though 
 it is also occasionally observed in adults. The rarity of 
 measles in adults is probably to be explained through the 
 fact that practically all children pass through the disease, and 
 one attack usually protects against subsequent infection, 
 though this is not always the case, as instances are recorded 
 in which more than one occurrence of the disease has been 
 observed in the same individual. It is endemic in all civilized 
 countries and occasionally breaks out in epidemic form. It 
 is a disease of late autumn and early spring. 
 
 It is directly communicable from the sick to the well ; the 
 secretions from the catarrhal surfaces and the exfoliated epi- 
 dermis are. capable of infection, and the disease may be car- 
 ried by fomites and by persons. 
 
 As in the case of varicella, vigorous efforts are rarely made 
 to prevent the spread of measles. It is so eminently conta- 
 gious that the usual efforts are considered of but little avail. 
 The patient should be isolated, and only the nurse and physi- 
 cian should have access to the sick-room. The napkins, 
 towels, dishes, bed- and body-clothing should be disinfected 
 before they are permitted to be taken from the room. After 
 recovery the room should be thoroughly disinfected and 
 cleaned, and well aired. 
 
 Rubeola {Rdtheln or Germajt measles) partakes of certain 
 of the characteristics of both measles and scarlatina, though 
 immunity to it is not conferred by an attack of either of these 
 diseases. Its cause is not known. It is considered a dis- 
 tinct, specific, febrile disorder. It is characterized by an 
 eruption. It is communicable by direct contact between the 
 
1 82 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 sick and the well. It is less contagious than measles. It is 
 more common in youth than in childhood. It often occurs 
 in epidemic form. 
 
 In other respects, what has been said for measles applies 
 also to rubeola, except perhaps that its spread is more readily 
 controlled than is that of measles. 
 
 SCARLET FEVER. 
 
 Definition, Cause, etc. — An acute, specific fever char- 
 acterized by the occurrence of erythematous rash upon the 
 skin, and accompanied by angina of varying degrees of 
 severity. Its cause is not known. The various bacteria and 
 protozoa that have been described as occurring in these cases 
 have not been proved to stand in causal relation to them. 
 
 Because of the constant presence of streptococci in the 
 angina that is associated with scarlatina, and because of the 
 occasional detection of this organism in the internal viscera 
 as well, it is held by some that the streptococcus found stands 
 in causal relation to the malady. This opinion is not, how- 
 ever, generally accepted, principally for the reasons that the 
 streptococci discovered do not differ from the ordinary pyo- 
 genic streptococcus, and that the disease is in all respects dif- 
 ferent from the usual results of infection by this organism. It 
 has been suggested that the clinical manifestations of the dis- 
 ease as well as the anatomical lesions, except those in the 
 throat, are the result of absorption of toxins produced by 
 the streptococci located in the diseased tonsils, and that the 
 disease is not necessarily a result of general sy.stemic infec- 
 tion ; this view also is not generally accepted. In the pres- 
 ent .state of our knowledge it can only be said that the ex- 
 citing cause of scarlet fever is as yet unknown, and that up 
 to date there have not been any suggestions upon this point 
 that have met with general acceptance. 
 
 It is contagious, though less so than measles. It occurs 
 
SCARLET FEVER. 
 
 83 
 
 both sporadically and as epidemic outbreaks. It is most com- 
 mon during the first ten years of life, though it is also seen 
 in adults. It is not very common in children under one year 
 The accompanying table (Table X.) (from Goodall 
 
 of age. 
 
 Table X. — Scar/atina at the Hospitals of the Metropolitan Asy- 
 lum'' s Board, London. Arranged according to ages (^Good- 
 all and Washbourn^^ : 
 
 
 Cases 
 admitted. 
 
 Deaths. 
 
 Fatality 
 per cent. 
 
 Under 5 years 
 
 5 to 10 " 
 10 to 15 " 
 15 to 20 " 
 20 to 25 " 
 25 to 30 " 
 30 to 35 " 
 35 to 40 " 
 40 years and u 
 
 pw 
 
 ar 
 
 d 
 
 
 
 
 
 
 23,072 
 
 33,647 
 
 14,399 
 
 5,319 
 
 2,509 
 
 1,215 
 
 665 
 
 281 
 
 243 
 
 4052 
 
 1789 
 
 345 
 
 139 
 
 65 
 
 38 
 
 31 
 
 16 
 
 15 
 
 17.6 
 
 5-3 
 2.4 
 2.6 
 
 2.6 
 31 
 
 4-7 
 5-7 
 6.2 
 
 Total . 
 
 
 
 
 81,350 
 
 6490 
 
 8.0 
 
 and Washbourn) strikingly illustrates these points. It is a 
 disease of autumn and winter (see diagram in Section I., un- 
 der the heading of Predisposing Influence of Season). It is 
 known among all peoples in all countries. 
 
 In mild outbreaks the fatality varies from 4.2 to 10 per 
 cent, while in severe epidemics it often reaches 15 and 20 per 
 cent, of those affected. 
 
 Dissetnination. — Scarlet fever is probably contagious at 
 all periods, but it appears to be especially so during the 
 stage of desquamation. The morbific agent, whatever it may 
 be, is very tenacious of life and pathogenic powers, and may 
 cling to clothing, furniture, and the like for very long periods, 
 retaining its power to reproduce the disease under favorable 
 circumstances. 
 
 Physicians, nurses and attendants, members of the family, 
 and fomites may carry the disease. Contagion may also occur 
 directly through the air of the sick-room, and this is perhaps 
 the commonest mode of transmission, especially when the air 
 is laden with the fine dust-like particles of epidermis shed by 
 
 ^ Infectiozis Diseases, by Goodall and Washbourn, Philadelphia, 1896. 
 
184 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 the patient during the stage of desquamation. In the earliest 
 stages — /. c, before the development of the eruption — it seems 
 to be less contagious than later. There is no evidence that 
 the disease is conveyed by water. There are a number of 
 instances in which it has been carried and more or less widely 
 disseminated by infected milk. By some writers the milk of 
 cows affected with streptococcus inflammation of the udder 
 is believed to be capable of causing the disease in human 
 beings who use it. 
 
 The angina of scarlet fever, when uncomplicated by dipn- 
 theria, is caused by the ordinary streptococcus pyogenes ; at 
 least this pathogenic species is so constantly present in the 
 condition, and in such numbers and often unassociated with 
 other disease-producing bacteria, that this opinion is reason- 
 ably justifiable. 
 
 Diphtheria may be engrafted upon scarlatina, in which 
 event bacilhis dipJitJicrice is found in the fauces, usually asso- 
 ciated with streptococci. 
 
 The angina of uncomplicated scarlatina is not, therefore, 
 etiologically identical with the pseudomembranous inflamma- 
 tion of the fauces that characterizes true diphtheria, though 
 both clinically and anatomically it may present a number of 
 features in common with it. 
 
 Prophylaxis. — The patient should be isolated in a room 
 as scantily and simply furnished as circumstances will permit. 
 The accompanying diagram illustrates what has been done 
 in Michigan by enforced isolation of cases of both scarlatina 
 and diphtheria (Chart 15). 
 
 Because of the ease with which the disease may be car- 
 ried, only the physician, nurse, or immediate attendant should 
 have access to the room ; and because of the tenacity to life 
 possessed by the scarlatina virus, great care should be given 
 to the disinfection (by boiling water, carbolic-acid solution or 
 chlorid-of-lime solution) of all articles before they are per- 
 mitted to leave the room. 
 
 The entire surface of the body of the patient should be 
 kept anointed with an antiseptic oil or ointment to prevent 
 the escape of particles of epidermis into the air. The.se pre- 
 
SCARLET FEVER. 
 
 185 
 
 Chart 15. — Showing influence of isolation and disinfection upon scar- 
 latina and diphtheria in Alichigan during the eight years i88j to 
 1894. 
 
 SCARLATINA 
 
 DIPHTHERIA 
 
 
 
 eglected 
 in 738 
 utbreaks 
 Average 
 
 Enforced ? 
 in 412 
 Outbreaks 
 Averajte 
 
 eglected 
 
 in 467 
 
 utbreaks 
 
 Average 
 
 Enforced 
 
 in 310 
 
 Outbreaks 
 
 Average 
 
 
 Ca 
 
 ses Deaths 
 
 Cases 
 
 Deaths C 
 
 ises Deaths 
 
 Cases 
 
 Deaths 
 
 
 
 
 
 
 
 
 
 
 14 
 
 
 
 
 
 
 
 14 
 
 U3-_ 
 _12._ 
 _U__ 
 _L0._ 
 
 _8__ 
 
 _6__ 
 _5__ 
 
 _3-- 
 
 _2_. 
 1 
 
 13 
 
 
 1. 
 
 >.04 
 
 
 
 13 
 
 
 
 
 
 
 
 1?! 
 
 
 
 
 
 
 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 9 
 
 
 
 
 
 
 
 8 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 fi 
 
 
 
 
 
 
 
 5 
 
 
 
 
 
 
 
 ■t 
 
 
 
 
 2.78— 
 
 
 
 J 
 
 
 
 
 
 2.09 
 
 
 
 ■ 
 
 
 
 ■ 
 
 
 1 
 
 
 1 IP^I 
 
 II II 1 
 
 
 
 From Report cf the Michigan State Board of Health, 1897. 
 
1 86 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 cautions should be observ^ed until desquamation is complete. 
 After removal of the patient the room should be carefully 
 disinfected with formaldehyde gas and the bedding subse- 
 quenth' subjected to steam sterilization, or the entire wall- 
 surfaces, including ceiling and floor, all furniture, mantles, 
 etc., should be thoroughly wiped with a cloth or sponge 
 soaked in a 3 per cent, carbolic-acid or i : 1000 corrosive- 
 sublimate solution ; the carpets, hangings (if such are 
 present), the bed-clothing, mattress, etc., should be disin- 
 fected by steam. These should be enveloped in sheets 
 soaked in either of the above solutions before being taken 
 from the room to the disinfecting station. 
 
 The bedstead and room should then be scrubbed with 
 soap and water, the windows opened, the door locked, and 
 the room thoroughly aired for several days. 
 
 WHOOPING COUGH. 
 
 ( Pertussis. ) 
 
 Definition, Cause, etc. — A contagious disease charac- 
 terized by a peculiar spasmodic cough that ends with a 
 " whoop " (inspiratory) from which the disea.se gets its desig- 
 nation. 
 
 The investigations that have been made upon whooping 
 cough with the hope of discovering its cause have been dis- 
 cordant in their results. Protozoa, diplococci, and bacilli 
 have from time to time been found microscopically and been 
 isolated by bacteriological methods from cases of this disease 
 by different observers. It is impossible to state definitely 
 which, if any, of the.se several micro-organisms plays the 
 etiological role in the di.sease ; for by the employment of 
 none of them has it been possible to reproduce the disea.se, as 
 it is seen in man, in lower animals. The most recent, and 
 in many ways the most satisfactory, of these .studies is that 
 
WHOOPING COUGH. 1 87 
 
 of Koplic/ who detected in 13 out of a series of 16 cases a 
 bacillus, which he thinks may reasonably be regarded as 
 playing an important part in the causation of the disease. In 
 the uncomplicated cases this bacillus was often the only 
 organism present. It was readily isolated in pure culture 
 through the employment of coagulated hydrocele fluid under 
 anaerobic conditions. Inoculations of animals with this 
 micro-organism resulted usually in local or general suppura- 
 tive infections, and in no instances did he succeed in getting 
 a condition that in any way suggested the disease as it 
 occurred in man. 
 
 Koplic considers it as reasonably certain that the organism 
 found by him is identical with that found and described by 
 Afanassjew in 1887. 
 
 " Probably the lungs are the seat of invasion, and the 
 catarrhal stage represents the period of growth of the micro- 
 organism, the paroxysmal attacks being caused by the 
 absorbed toxins, and being comparable to the convulsions of 
 tetanus " (Goodall and Washbourn). It is seen both sporad- 
 ically and as outbreaks of varying extent. 
 
 It is a disease of childhood, though no age is exempt from 
 it. It is more frequent, and also more serious, in cold than 
 in warm climates. According to the statistics of Hirsch, the 
 season of the year seems to be of little influence upon the 
 prevalence, though it is usually considered, in this latitude, to 
 be a disease of winter and spring. 
 
 The fatality of this disease varies considerably in different 
 epidemics, and depends largely upon the secondary compli- 
 cations. It is much more fatal in negroes than in white chil- 
 dren, and in females than in males. It is a serious malady, 
 and in England ranks next to diarrhea as the cause of mor- 
 tality among young children, though the last United States 
 census shows it to be hardly so fatal in this country. A 
 single attack protects against recurrence of the disease in the 
 majority of cases. 
 
 The disease is disseminated directly from the sick to the 
 well individual through the breath and through matters ex- 
 
 ^ CenU-albl. fur Bakteriologie und Parasitenkuttde, 1897, Bd. xxii., S. 222. 
 
1 88 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 truded while coughing, though there is reason to beHeve that 
 its x'irus ma)' be harbored about rooms, in clothing, and upon 
 furniture. It is contagious from the onset until the " whoop " 
 has disappeared. 
 
 Prophylaxis. — The serious nature of whooping cough, 
 especially when occurring in very young and feeble children, 
 calls for more attention to the prevention of its spread than 
 it ordinarily gets. 
 
 The patient should be carefully isolated for as long as the 
 paroxysmal cough exists, for during this entire period they 
 are capable of disseminating the disease. It is hardly neces- 
 sar}^, therefore, to state that children with whooping cough 
 should never be permitted to attend school. All handker- 
 chiefs, towels, napkins, eating-utensils, etc., used by the pa- 
 tient should be disinfected before being taken from the apart- 
 ment in which the patient is isolated. The room in which 
 the patient has been isolated should be properly disinfected 
 after it has been vacated ; during its occupancy all horizontal 
 surfaces should be wiped from time to time with a cloth 
 moistened in a 3 per cent, carbolic-acid solution. When the 
 weather permits, the patient should have the freest possible 
 access to fresh air, sunlight, and moderate outdoor exercise. 
 
 MUMPS. 
 
 Definition, Cause, etc. — An acute, specific infection 
 characterized by swelling of the parotid and other salivary 
 glands. Its cause is not as yet known. Both bacilli and 
 micrococci hav^e been discovered in the swollen glands, but 
 they are not shown to stand in causal relation to the disease. 
 
 It is endemic in all countries. It frequently occurs as local 
 epidemics. It is most prevalent in autumn and spring. It 
 occurs between the ages of five and fifteen years, less com- 
 monly in older persons, and rarely in children under one 
 
MALARIAL FEVER. 1 89 
 
 year. It is somewhat more common in boys than in girls. 
 It is markedly contagious and spreads by direct contact. The 
 breath and secretions from the mouth seem capable of caus- 
 ing infection. It is not conspicuously disseminated through 
 the agency of persons or by fomites. 
 
 Its period of incubation is reckoned as from fourteen to 
 twenty-five days. The patient is considered infectious, especi- 
 ally infectious, during the period of active inflammation of the 
 salivary glands. 
 
 These patients should be isolated for at least three weeks 
 from the onset of the disease. 
 
 MALARIAL FEVER. 
 
 Definition, Cause, etc. — The term malarial fever is 
 used generically to indicate a group of febrile disorders that re- 
 sult from the invasion of the body by a specific micro-organism 
 — VIZ., Plasmodium malaricE — discovered by Laveran in 1880. 
 Malarial fevers are therefore infectious, though they are not 
 contagious. 
 
 These fevers may be divided clinically into two primary 
 groups — viz., the intermittent and the remittent or continued 
 fevers, though etiologically they are all dependent upon the 
 same or closely allied parasites. 
 
 The intermittent malarial fevers are characterized by the 
 periodic occurrence or paroxysms, consisting of chills, fever, 
 and sweating, in the order named, and by the disappearance 
 of symptoms during the interval between the paroxysms. 
 According to the length, in days, of the interval between 
 paroxysms, the commoner manifestations of the intermittent 
 fevers are designated as quotidian — /. t\, those occurring every 
 day ; tertian, occurring ever>' other day ; quartan, occurring 
 after an interval of two days. 
 
 In the remittent or continued types of the fever the char- 
 acteristic, periodic occurrence is often lost. The fever may 
 
190 
 
 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 be continuously above normal, and there may be regular or 
 irregular remissions. 
 
 Pernicious malarial fever is a rare manifestation of the dis- 
 ease in this latitude. It represents a condition in which the 
 body is more or less suddenly overwhelmed by the malarial 
 poison. It is often fatal. Three clinical forms of pernicious 
 malarial fever are recognizable — viz., the comatose, in which 
 the symptoms are principally cerebral ; the hemorrhagic, 
 characterized by hemorrhage from the mucous membranes 
 and from the kidneys ; and the algid form, in which the most 
 conspicuous symptom is extreme prostration, with little or 
 no tendency to rise in temperature. The true nature of 
 these symptoms is frequently difficult of recognition by the 
 
 g)@@@(g)@(g) 
 @@®©@@ 
 
 ^^ /« /r /^ 
 
 ®@@®@@(g) 
 
 /^ J^ J^ J^ '^ ^^ 
 
 22 ^J 
 
 Fig. 22. — Diagrammatic representation of the succession of shapes assumed 
 by an actively amoeboid intracorpuscular plasmodium during the course of five 
 minutes (author's observations). 
 
 ordinary clinical procedures. This difficulty is, however, 
 easily cleared away by microscopical examination of the 
 blood for the causative parasite. 
 
 The Plasmodium of malaria is an animal parasite belonging 
 to the protozoa — /. c, it con.sists of simple, undifferentiated 
 protoplasm. Because of its presence in the blood it is often 
 referred to as " hematozoon." In tlie blood of persons suffer- 
 ing from the .same type and in the blood of those suffering 
 
MALARIAL FEVER. I9I 
 
 from different types of malarial fever, a number of different 
 forms or developmental phases of the parasite may be 
 observed. 
 
 It is hardly appropriate in a sketch of this character to 
 describe in detail all the various forms that are assumed by 
 the Plasmodium of malaria, or to enter into a full description 
 of the developmental steps through which it passes in the 
 several forms of fever in which its life history has been care- 
 fully studied. It will suffice, for purposes of illustration, to 
 follow here the development of the parasite in one of the 
 typical clinical manifestations of intermittent fever, and to 
 refer the reader to special monographs for full details of the 
 subject.^ The commonest of the intermittent fevers encoun- 
 tered in this vicinity is the tertian type — i. c, that in which the 
 paroxysms occur on each alternate day. 
 
 If one examine the fresh unstained blood of a patient suf- 
 fering from tertian intermittent fever, during the latter part of 
 or shortly after the paroxysm, one will observe that many of 
 the red blood-corpuscles contain within them small, round, 
 pale bodies that occupy from about a sixth to a fifth of the 
 corpuscle in which they are located (i in Fig. 23). They 
 are actively amoeboid and, as a result, the pseudopedia that 
 they are constantly throwing out, cause them to assume a 
 variety of shapes that follow upon one another in quick 
 succession (see 2, 3, 4, 5, Fig. 23). As time passes on, these 
 small bodies increase in size ; gradually reddish-brown pig- 
 ment-granules begin to appear within them. These are at 
 first very minute. They vary in shape, and are in active, 
 oscillating motion. The organism gradually increases in 
 size, and the pigment becomes more manifest. The cor- 
 puscle in which the organism is located becomes paler, and, 
 when compared with its normal neighbors, is seen to have 
 appreciably increased in size. With further growth of the 
 
 ' The most complete and satisfactory treatment of this subject that it has 
 been my good fortune to encounter is contained in " The Malarial Fevers of 
 Baltimore, etc.," by Thayer and Yiewetson, Johns Hopkins Hospital Reports, 
 1895, vol. V. See also — Lectures on the Malarial Fevers — by Wm. Sidney 
 Thayer, M. D., published by Appleton & Co., N. Y., 1897. 
 
192 
 
 HYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 organism its amoeboid movement becomes less apparent. 
 The amount of pigment increases ; it continues its active 
 dancing motion, and is now seen to be irregularly arranged 
 around the periphery of the organism (6 in Fig. 23). Before 
 the end of forty-eight hours the organism has usually com- 
 pletely filled its enveloping red blood-corpuscle. The pig- 
 ment is very much increased in amount, and surrounding 
 the organism is a thin rim, the remains of the invaded cor- 
 puscle. Sometimes all indication of red corpuscle disappears. 
 When this stage is reached, the hitherto actively oscillating 
 pigment becomes motionless, or nearly so, and tends to col- 
 lect near the center either as a single black or as a mass of 
 
 Fig. 23. — Some of the principal forms assumed by the plasmodium of tertian 
 fever in the course of its cycle of development (after Thayer and Hewetson). 
 
 dark, almost black granules. The substance of the organism 
 now becomes finely granular and somewhat more refractive. 
 Indistinct radial striations make their appearance at the 
 periphery of the body ; these grow more and more distinct, 
 till finally the central pigment-mass is surrounded by from 
 12 to 20 or more pear-shaped segments that give to the 
 whole a rosette-like appearance (7, 8, 9, 10 in Fig. 23). Each 
 segment presents a small refractive central spot. A little 
 later the central pigment-clump is seen to be surrounded by 
 a group of completely separated, round, hyaline bodies simi- 
 lar in all respects to those seen in the corpuscles at the 
 beginning of the observation (11 in Fig. 23) — i. c, during the 
 latter part of, or shortly after, the preceding paroxysm ; at 
 
MALARIAL FEVER. 1 93 
 
 this time also one begins to notice the appearance of similar, 
 small, hyaline bodies in some of the red corpuscles. " We 
 have thus a very suggestive chain of evidence in favor of the 
 view that this is a reproductive process ; that these hyaline 
 segments resulting from the division of the organism are 
 identical with the fresh hyaline forms that appear in the red 
 cells." ^ It is highly probable that these segments represent 
 a brood of young parasites which, in time, invade a fresh set 
 of corpuscles and undergo the cycle of development and 
 reproduction described for their progenitors. The final de- 
 velopmental phase of the parasite — viz., segmentation — is 
 always coincident with or a little antecedent to the occurrence 
 of a characteristic paroxysm. 
 
 Based upon these observations Golgi formulated the fol- 
 lowing laws : " Each febrile paroxysm is closely connected 
 with the cycle of development of a generation of parasites : 
 the beginning of each paroxysm corresponds to the matura- 
 tion of a generation of parasites : the severity of the paroxysm 
 is, in general, proportional to the number of the parasites 
 which are found in the blood." 
 
 Opinion as to the actual cause of the characteristic parox- 
 ysm is divided. Golgi believes it to be due to the invasion 
 of the red blood-corpuscles by the brood of young parasites 
 that have resulted from the segmentation of the mature or- 
 ganism, while Antolisei considers the chill to be due to the 
 actual segmentation of the fully-grown plasmodia, rather than 
 to the invasion of the corpuscles. Baccelli suggests the toxic 
 origin of the paroxysm, and advances the idea (now accept- 
 able to the majority of investigators) that the phenomenon 
 results from the influence upon the vasomotor centers of a 
 poison, either liberated at the time of segmentation by the 
 parasite or occurring as a product from the red blood-corpus- 
 cles that have been destroyed. 
 
 In addition to the small and large amceboid and pigmented 
 forms that are regularly observed in the developmental cycle 
 of the parasite, in tertian, quartan, and aestivo-autumnal fevers, 
 other forms are encountered. The most conspicuous of these 
 
 1 The above description is condensed from Thayer and Hewetson, loc. cit. 
 13 
 
194 
 
 HYGIENE OF TJ^ANSMISSIBLE DISEASES. 
 
 are the flagellated varieties and the " crescents " (Fig. 24). 
 The former are seen in one or all varieties of intermittent 
 fever, usually at or about the period of the paroxysm ; and 
 in the aestivo-autumnal fever Thayer and Hewetson frequently 
 detected them in the blood-specimens long after all febrile 
 symptoms had disappeared. They are easily recognized, 
 consisting of a pale, pigmented body often as large as, some- 
 times larger (according to circumstances) than a red corpus- 
 cle, which is provided with one or more slender, thread-like 
 flagella that lash about in a very active manner. One or 
 
 Fig. 24. — Crescentic and flagellated forms of Plasmodium malariae : i, flagel- 
 lated form of tertian fever; 2, flagellated form of quartan fever; 3, crescents, and 
 4, flagellated form of gestivo-autumnal fever (after Thayer and Hewetson). 
 
 more flagella may become detached and lead an independent 
 existence. The pigment-granules contained within the body 
 are in active dancing motion, and an amoeboid movement of 
 the body can usually be made out. For reasons too numer- 
 ous to discuss here, the flagellated forms are regarded by 
 many to be degenerative forms of the parasite, while, on the 
 other hand, others consider them to represent the organism 
 in its highest stage of development. 
 
 In his paper " On the Hematozoon Infection of Birds," ' 
 MacCallum describes an observation of fundamental impor- 
 tance that he has made upon the developing parasites in the 
 blood of crows. He has ob.served that in a particular stage 
 
 ^ Jour, vf Experimental Medicine, 1898, vol. ill., p. 117. 
 
MALARIAL FEVER. 1 95 
 
 of development two forms of the organism may be simulta- 
 neously encountered : — one a motionless pigmented, the other 
 a hyaline, actively motile, flagellated body. After a time the 
 flagella become detached from the latter and one of them may 
 readily be seen to penetrate the motionless granular form, 
 while the remaining flagella from the same parent organism 
 disappear. He regards this as a sexual phenomenon and 
 suggests the probability of the flagellated malarial parasite 
 of man having a similar significance. 
 
 The " crescents," as their name implies, are crescentic in 
 shape. They are somewhat refractive bodies that are usually 
 marked about the center with an irregular clump or ring of 
 pigment-granules. They may lie free, or have attached to 
 them what appears to be the remains of a red blood-cor- 
 puscle. They are encountered only in the protracted forms 
 of malarial poisoning — /. e., after the second week in the 
 aestivo-autumnal fever, in the malarial remittent fevers, and 
 in the cachectic victims of chronic malaria. Their significance 
 is not definitely understood. 
 
 In the present state of our knowledge it is difficult to 
 decide whether all the various forms of the parasite, as seen 
 in the blood in the different expressions of malarial infection, 
 represent developmental stages of one and the same poly- 
 morphic organism, or whether some of them are phases of 
 one and others of another variety, or of other varieties, of the 
 closely-allied species of protozoa that are all capable of in- 
 ducing symptoms characteristic of malarial fever. Certain 
 it is, however, that among the most competent students of 
 these fevers there is practically an agreement of opinion that 
 at least three distinct varieties of the parasite are concerned 
 in producing the three commonest manifestations of malarial 
 infection — viz., the tertian, the quartan, and the aestivo- 
 autumnal fevers — and that during the course of these fevers 
 it is possible to detect a pretty regular series of develop- 
 mental phases through which each of the varieties of the 
 parasite passes, beginning with the small, simple, intra- 
 corpuscular body, and ending with one mode of segmenta- 
 tion (reproduction) or another. The parasite has not been 
 
196 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 observed outside the body, and we have not as yet sufficient 
 data on wliich to base a positive statement as to all the portals 
 through which it gains entrance to the body. 
 
 Geographical Distribution. — The malarial fevers have 
 a very wide distribution. They vary markedly in the degree 
 of their intensity in different localities. 
 
 It may in general be said that the most severe manifesta- 
 tions are seen in tropical countries ; and that as we pass from 
 these regions of greatest malignancy into the temperate zones, 
 the centers of endemicity become less frequent and the char- 
 acter of the disease less virulent. 
 
 The disease is seen in its greatest severity upon the west 
 coast of Africa ; in Algeria ; along the coasts of India, China, 
 and Persia ; in Chili, Peru, and Brazil ; on the eastern coasts 
 of Central America and Mexico ; and along the shores of 
 the southern United States that border upon the Gulf of 
 Mexico. 
 
 The principal malarial regions of Europe are southern 
 Russia in the region of the Caspian Sea ; southern Germany 
 along the lower Rhine and Danube ; the west coast and a 
 large part of northern Italy ; southeastern France, especially 
 in the valleys of the Loire and Rhone ; and the southwest 
 coast of Portugal. 
 
 In isolated areas the disease is seen in northern, north- 
 western, and western Europe, though to a much less extent 
 than in the other localities named. It is rare in England, 
 prevailing to only a limited degree near the east coast. 
 
 In this countiy the disease is much more frequent, and its 
 manifestations are much more severe in parts of the southern 
 and southwestern States than elsewhere. In the Middle 
 States there are a number of endemic centers, while as we 
 pass into the northern and New England States these 
 become much reduced in number. In the northwestern 
 States and in northwestern Canada the disease is almost 
 unknown. In late years both the frequency and the severity 
 of malaria in this latitude have undergone a veiy great modi- 
 fication, and many localities in which the disea.se was formerly 
 endemic have become practically free from it. 
 
MALARIAL FEVER. I97 
 
 The remittent and pernicious forms of malaria are most 
 frequently encountered in tropical and subtropical regions. 
 The intermittent fevers, especially the quotidian and the 
 quartan, while also common in the warmer localities, are 
 widespread in their distribution, being frequently encoun- 
 tered in temperate latitudes. The commonest, and at the 
 same time the least malignant, form of malarial fever that 
 ordinarily prevails in the higher latitudes, is the tertian 
 remittent fever. 
 
 Conditions that Influence the Development of the 
 Malarial Virus. — The designations " paludism," " paludial," 
 and " marsh fever," by which malarial fever is variously 
 known, indicate the close relation that it is believed to have 
 to marshy and swampy localities. 
 
 Notwithstanding the fact that malaria is known to occur in 
 localities that are not marshy, and on the other hand to be 
 often absent from those that are low-lying and swampy, it 
 must be admitted that it is much more frequent and severe in 
 partly inundated, badly drained lands than in localities of 
 higher altitude, where the drainage of the soil is more com- 
 plete. 
 
 A certain amount of water in the soil appears to be an es- 
 sential for the development of the malarial virus. 
 
 Marshes that are alternately flooded and imperfectly 
 drained of water offer conditions that are most favorable to 
 the occurrence of malaria. A malarious marsh if completely 
 and permanently flooded may become innocuous ; but it will 
 usually resume its dangerous character if the water-level is 
 permitted to fall sufficiently low to expose its earthy surface. 
 
 Many marshes that are periodically flooded by salt water 
 are the breeding-grounds of the most malignant forms of ma- 
 larial poisons, while others, even when located in the tropics, 
 are free from such danger. 
 
 It is a notorious fact that malarious swamps may be, and 
 often have been, robbed of their noxious qualities by proper 
 drainage. Where adequate arrangements for drainage have 
 not been provided, malaria has been known to follow upon 
 the artificial irrigation of arid lands. 
 
198 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 The soil conditions that are regarded as especially favora- 
 ble to the development of malaria are excess of moisture and 
 of decaying vegetable matters, such as obtain in low-lying, 
 marshy places, in the broad alluvial deltas of great rivers, and 
 along the valleys of smaller steams, particularly where these 
 are located in the warmer latitudes. 
 
 " By far the largest proportion of cases of malarial fevers 
 originates, not from exposure to the air of marshes, but from 
 the malaria given off from damp bottom lands, from the del- 
 tas of rivers subject to annual overflow, from the margins of 
 streams when these are exposed during the dry season, and 
 especially from alluvial plains under cultivation. This natur- 
 ally results from the necessary exposure in these situations, 
 and from the fact that malarious marshes are avoided as far 
 as possible " (Sternberg). 
 
 The geological condition, pci' sc, of a soil does not appear 
 to play an important part in the production of the virus, nor 
 does its locality seem in all instances to be an essential factor, 
 for the disease has been observed in elevated mountainous 
 districts and in low-lying sandy plains. 
 
 Throughout the malarious zones it has generally been ob- 
 served that the breaking up of virgin lands has, as a rule, re- 
 sulted in the appearance of malaria in the immediate vicinity, 
 and that often by prolonged cultivation of such soils the dis- 
 ease ultimately becomes less frequent and severe, and may 
 finally disappear altogether from the neighborhood. 
 
 While the above-mentioned conditions of the soil are in the 
 main those usually regarded as most favorable to the exist- 
 ence of malaria, .still they are not infallible indications. In fact, 
 one cannot certainly predict from physical conditions alone 
 whether this or that locality is healthy or not as regards 
 malarial fever. On this point Osier expres.ses the opinion 
 that the only safe guide is the existence of the disease among 
 people residing in the immediate vicinity. 
 
 The influence of rainfall depends upon circumstances. If 
 by an excess of rainfall the low-lying malarious lands be- 
 come completely flooded, the disease may, in consequence, be 
 temporarily arrested. An impervious surface-soil that does 
 
MALARIAL FEVER. I99 
 
 not readily become saturated, but rather favors the rapid 
 shedding of rain-water, is not regarded as favorable to the de- 
 velopment of the disease. A permeable, shallow surface-soil 
 overlying an impervious stratum may favor the growth of the 
 virus under the conditions of very moderate rainfall. 
 
 As a rule, diy, porous, sandy or gravelly soils are less fre- 
 quently favorable to malaria than those that more readily re- 
 tain moisture and are constantly partly saturated with water. 
 
 Influence of Season. — In this latitude malaria appears 
 most conspicuously in spring and autumn, and least of all in 
 winter — /. c, it occurs in those seasons that are characterized 
 on one hand by beginning growth of vegetation, and on the 
 other by its death and decay. 
 
 A moderately high temperature appears to be an essential 
 factor to the development of the malarial virus. In both 
 tropical and temperate regions the fever is more prevalent 
 after prolonged hot spells. According to Wood and to 
 Drake, malaria is rarely developed at a temperature lower 
 than 60° F. 
 
 As a rule, it becomes less frequent and less malignant as 
 we recede from the thermal conditions that obtain in the 
 tropics to those of higher latitudes. 
 
 Influence of Air=currents. — There is a widespread convic- 
 tion that the malarious virus may be carried by winds. In 
 malarious regions near the coast the land-breezes, especially 
 if they traverse neighboring marshes, are poisonous, while the 
 sea-breezes are not. Many localities that may be otherwise 
 highly suspicious, but which are continuously wind-swept, are 
 often free from the disease. This is especially true for many 
 of the tropical islands of the Gulf of Mexico and the Pacific 
 Ocean. 
 
 Under ordinary circumstances, the virus of malaria is not 
 believed to ascend very high above the ground. In malarious 
 districts it is a common observation that the dwellers in high 
 places, in the upper stories of houses, etc., may escape the 
 disease, while those on the ground-floor contract it. 
 
 When regularly seen in places of high altitude it is not 
 usually due to its ascent with currents of air from the low 
 
2CK) HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 lands, but rather to its development under local conditions 
 that may exist at the high level. There is, however, evidence 
 to indicate the possibility of its being wafted to high altitudes 
 by ver}' strong winds blowing along narrow, insalubrious val- 
 leys and up mountain sides. 
 
 Modes and Portals of Infection. — Since the malarial 
 parasite has not been observed outside the body, it is impos- 
 sible to speak with certainty as to all the modes of its entiy 
 into the system. 
 
 The ideas hitherto held with regard to this point are that 
 infection may occur through the alimentary and respiratory 
 tracts, and through small wounds of the skin, such, for 
 instance, as those resulting from the bites of insects, espe- 
 cially mosquitoes. Though these views are based upon what 
 are believed to be pretty trustworthy observations, still, in 
 the light of experiment, they appear to be of very different 
 degrees of importance. As a result of modern investigations 
 it seems probable that, of the three portals mentioned, skin- 
 wounds made by insects are the most frequent and the 
 alimentar}^ tract the least frequent channels through which 
 the organism gains access to the blood. 
 
 The investigations of a number of the Italian observers 
 (Celli, Marino, Zeri, Grassi, and Feletti) demonstrate that it 
 is practically impossible to cause malarial infection by way 
 of the alimentary tract. In these experiments healthy per- 
 sons were permitted to drink of water from malarious 
 marshes ; enemata of similar waters were given to other 
 persons ; and, in the experiments of Grassi and Feletti, 
 healthy persons were allowed to drink of blood from malarial 
 patients, but in no instance did malaria result. We feel 
 justified, therefore, in concluding that either this is a very 
 unusual mode of infection, or that some important factor 
 that is present in the course of natural infection was inad- 
 vertently omitted from the experiments. 
 
 There is a ver}' general impression that infection can occur 
 through the respiratory tract, though as yet we have no 
 proof of it, and the results of experiment leave the question 
 still in a very unsatisfactory state. 
 
MALARIAL FEVER. 20I 
 
 With regard to infection through wounds of the skin, 
 Bignami ' holds the opinion that this is the most frequent 
 channel throug-h which the disease is contracted, and he 
 advances very strong arguments in support of the view that 
 infection is usually due to the bites of mosquitoes, much in 
 the same way that the Texas fever of cattle originates with 
 and is disseminated by the bites of infected ticks. Among 
 many forcible arguments in support of his hypothesis, Big- 
 nami states that in the highly malarious regions of Italy 
 the precautions taken by the natives against malarial fever 
 are always equally effective against mosquitoes. These indi- 
 viduals in some localities sleep in houses elevated upon 
 stakes or piles to a distance of 12 to 15 feet above the 
 ground. They avoid going out at night. They are careful 
 not to sleep in the open air at any time day or night. They 
 close their windows with badly fitting shutters, which impede 
 the ingress of insects but not of air. They take great care 
 of their mosquito curtain, making it of very close net, under 
 which they sleep, thoroughly shut in, notwithstanding the 
 great heat. Bignami ascribes the limited vertical ascent of 
 the malarial virus in the air to the fact that mosquitoes as a 
 rule do not fly very high above the ground. In view of the 
 fact that the only method by which genuine malaria has been 
 produced experimentally in man is that of inoculation with 
 the blood of malarial patients, and that this has repeatedly 
 been done, the opinion advanced by Bignami acquires con- 
 siderable importance. In a discussion of this subject Laveran 
 also expresses the belief that the disease is much more often 
 contracted through the bites of insects, particularly mosqui- 
 toes, than in any other way.^ 
 
 The whole question, however, of mode of infection in 
 malaria is as yet in a somewhat unsatisfactory state. 
 
 Prophylaxis. — From the foregoing the measures of pre- 
 vention may readily be summarized as follows : 
 
 Efficient drainage of damp soils. 
 
 ^ " Hypothesis as to the Life History of the Malarial Parasite outside the 
 Human Body," Lancet, Nov. 14 and 21, 1896. 
 
 ^ "Comment prend — on le paludisme," Revue d'' Hygiene, 1896, p. 1049. 
 
202 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 Place of residence as high above and as far removed from 
 low-lying districts as circumstances will permit. 
 
 Avoid sleeping in the open air in malarious districts during 
 either the day or night. 
 
 Adequate protection against the bites of insects, especially 
 of mosquitoes. 
 
 Though experimental evidence contra-indicates its neces- 
 sit}', both food and water should be cooked in malarious 
 regions. 
 
 While in malarious regions it is a valuable precaution to 
 take from 4 to 5 grains of quinine daily on rising in the 
 morning. 
 
 Note i. — From a series of experiments, the results of whicli have been 
 recently published i^Centralbl. fiir Baktei-iologie, 1897, Bd. xxi., S. 49), Celli 
 and Santeri draw the conclusion that the period of incubation of malarial in- 
 fection may be very much prolonged through the injection into the individual 
 of the blood-serum from certain animals that are naturally immune from ma- 
 laria. This observation, while of scientific interest, can hardly be regarded 
 as of very great practical importance, since we already possess, in quinine, a 
 body that, in both its therapeutic and prophylactic employment, is known to 
 be a specific, in the full sense of the word, against malaria. 
 
 Note 2. — It is my pleasant duty to acknowledge the assistance that I have 
 received, in the preparation of this sketch, from the exhaustive monograph of 
 Thayer and Hewetson, already referred to. 
 
 YELLOW FEVER. 
 
 Definition. — An acute, specific, febrile disease of tropical 
 and subtropical climates that is characterized by jaundice, 
 hemorrhages from the mucous membranes, vomiting of dark 
 or black, grumous matters (the so-called " black vomit ") and 
 albuminuria. It occurs endemically in certain districts of the 
 tropics, and at times spreads epidemically over regions be- 
 yond the zone of endemicity. Though its cause is not known, 
 it is obviously an infectious disease. It is not regarded as con- 
 tagious — /. c, directly transmissible from the sick to the well. 
 
YELLOW FEVER. 
 
 203 
 
 Btiology. — Notwithstanding the fact that a good deal has 
 been said and written during the past two years on the etiol- 
 ogy of this disease, there are still good grounds for believing 
 that the exciting cause of yellow fever has not yet been dis- 
 covered. 
 
 The contributions upon the subject that have received the 
 most serious consideration are those of Sternberg and of 
 Sanarelli. 
 
 In 1888 Sternberg called attention to the micro-organism, 
 designated by him as " bacillus X" that he had found in 
 about 50 per cent, of fresh yellow-fever cadavers examined 
 by him. He did not certainly regard it as the cause of the 
 disease, though, because of its pathogenic properties and its 
 presence in only yellow fever, he thought it might possibly be, 
 in some way or other, concerned in its etiology. 
 
 In 1897 Sanarelli described a bacillus, designated by him 
 z.^ '^ bacillus ictC7'oides',' that he had discovered in about 58 
 per cent, of yellow-fever cadavers examined by him at Monte 
 Video. From its presence in only yellow-fever cadavers, its 
 pathogenesis, and the peculiarity of the lesions produced in 
 animals inoculated with it, he feels justified in regarding it as 
 the specific exciting cause of yellow fever. He claims to 
 have rendered animals immune from the disease by the use 
 of his cultures of this bacillus, and he further states that the 
 serum obtained from such immune animals has the property 
 of protecting individuals into whom it may be injected from 
 yellow fever. A comparison of the descriptions of these two 
 organisms leaves little doubt that they are closely related, 
 though not identical ; that they can reasonably be embraced 
 within the colon group of bacilli ; and that the results of 
 inoculations of animals with them do not, in the majority of 
 cases, materially differ from those obtained occasionally 
 through the injection of the colon bacillus or some one of 
 its varieties.^ As a result of these facts, the opinion expressed 
 
 ^ Reed and Carroll {^Medical News, April 29, 1899) have subjected '-'■ ba- 
 cillus X" and ^'■bacillus ideroides'''' to exhaustive study, and as a result reach 
 the following important conclusion : " We venture to express the opinion that 
 bacillus icteroides (Sanarelli) is a variety of the hog-cholera bacillus, and that 
 
204 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 by Sanarelli as to its standing in causal relation to yellow 
 fever has not met with general acceptance on the part of 
 bacteriologists. 
 
 It has been suggested, or rather predicted, that if the 
 cause of this disease is ever discovered it will be found to be a 
 haematozoon, zoologically allied to the malarial parasite of 
 man, but on this point there is as yet no evidence whatever. 
 
 Geographical Distribution. — According to Hirsch, the 
 geographical limits between which it is possible for yellow 
 fever to occur are represented in the western hemisphere by 
 the latitudes 34° 54' south (Monte Video) and 44° 39' north 
 (Halifax) ; and in the eastern hemisphere by 8° 45' south 
 (Ascension) and 51° 37' north (Swansea). Within these 
 boundaries there are localities from which the disease is never 
 absent ; others in which it is more or less frequently present, 
 and others in which it only occasionally occurs as a result of 
 accidental importation. 
 
 The three principal districts in which yellow fever is really 
 endemic are the West Indies, the Mexican part of the Gulf 
 coast, and the Guinea coast at Sierra Leone. The latitude of 
 these localities is regarded by Guiteras as comprising the 
 " focal zone " of yellow fever, while the coast of tropical At- 
 lantic, both in America and in Africa, he designates as the 
 " perifocal " zone, or the regions of periodic epidemics. 
 
 Epidemics of this disease were at one time frequent in this 
 country, especially during the last and the early part of the 
 present century. In late years they have undergone a con- 
 spicuous decline in frequency. The last extensive epidemic 
 of yellow fever in the United States occurred in Louisiana, 
 Mississippi, and Alabama in 1878. Severe epidemics occurred 
 in this city (Philadelphia) in 1693, 1762, 1793, and 1802. In 
 the epidemic of 1793, the most serious outbreak of the dis- 
 ease tliat has ever occurred in a city of the Middle States, the 
 mortality for the four months of its continuance was about 10 
 per cent, of the entire population of the cit}'. 
 
 it .should Vje considered only as a secondary invader in yellow fever. We find 
 that bacillus X (.Sternberg) presents marked differences from the foregoing 
 microorganisms. ..." 
 
YELLOIV FEVER. 205 
 
 Race Susceptibility and Immunity. — Absolute im- 
 munity from yellow fever is not possessed by any peoples as 
 a natural, racial characteristic. 
 
 Relatively speaking, those peoples, be they Europeans, 
 Africans, or Creoles, who are permanent residents in the 
 endemic zones of the disease, exhibit less susceptibility than 
 do newly arrived strangers from the colder, more northern or 
 southern latitudes. 
 
 According to Townsend (quoted from Hirsch) " the mor- 
 tality of vomito ^ to the new-comer from the cooler latitudes 
 may be said to be in an exact ratio to the distance from the 
 Equator of his place of nativity and residence." 
 
 Barton presents the following instructive statistics upon 
 the comparative mortality among strangers and natives in 
 the epidemic at New Orleans in 1853. This illustrates very 
 well the statement made by Townsend. 
 
 Of each 1000 deaths from yellow fever that occurred 
 among various races exposed to it, there were of — 
 
 Native Creoles ... 3-58 
 
 Strangers from West Indies, Mexico, and South America . . 6. 14 
 
 " " Southern United States 13-22 
 
 " " Spain and Italy 22.06 
 
 " " Middle United States 30.69 
 
 " " New York and New England 32-83 
 
 " " Western United States 44-23 
 
 " " France 48- 13 
 
 " " British America 50-24 
 
 " " Great Britain 52- 19 
 
 " " Germany 132.01 
 
 " " Scandinavia 163.26 
 
 " " Austria and Switzerland 220.08 
 
 " " The Netherlands 328.94 
 
 It is sometimes said that the Creole and the African are 
 naturally immune from yellow fever. This is not true. At 
 birth neither of these peoples is insusceptible, and Guiteras 
 states that " the foci of endemicity of yellow fever are essen- 
 tially maintained by the Creole infant population." 
 
 Since a single, non-fatal attack of yellow fever affords 
 
 ^ A synonym for yellow fever. 
 
206 JIYGIENE OF TRAXSMISSIBLE DISEASES. 
 
 more or less complete protection from subsequent attacks, 
 it is plain that by prolonged residence in the zones of en- 
 demicit}- and constant exposure to infection a certain propor- 
 tion of the population, including all races, acquires such 
 resistance, by having passed safely through this fever. It 
 is interesting to note that the so-called " acclimatization " to 
 this disease that many natives possess is more or less com- 
 pletely lost after removal to cooler latitudes, and that such 
 indix'iduals on their return to the zone of endemic yellow 
 fever often exhibit a degree of susceptibility equal to that of 
 total strangers to the district. 
 
 Seasonal and Geographical Influences. — Yellow 
 fever is most common in low lands along the coast, and 
 along great rivers in hot climates. It rarely or never occurs 
 at high altitudes. When it breaks out in cities, they are usu- 
 ally low-lying, badly-drained, and in an unsanitaiy condition 
 generally. It usually appears first in the poor and over- 
 crowded districts. It is a disease of summer, though it 
 may persist for a time after the advent of cool weather. 
 It is promptly checked by frost, though this does not per- 
 manently eradicate the poison, for the disease may reappear 
 with the advent of warm weather again. It has been observed 
 that on infected ships the disease will sometimes disappear as 
 they sail to cooler, northern latitudes, and will reappear with 
 return to the warmer climate. 
 
 Dissemination. — The tropical districts from which yellow 
 fever is never absent — i. e., the focal zone — manifestly offer 
 certain climatic and telluric conditions that are directly favor- 
 able to the development and perpetuation of the yellow-fever 
 virus. Whether this virus is located in the soil or in the 
 water of these localities, or whether it is disseminated by 
 the water, the air, or by insects, it is impossible to say, since 
 nothing vvliatever is known as to its nature or habitat. 
 
 There is an abundance of evidence to show that yellow 
 fever is often conveyed from place to place along lines of 
 traffic, both by sea and land. Ships and their cargoes are 
 regarded as frequent means of conveying the disea.se. The 
 poison is known to have clung persistently to the hulls of 
 
YELLOW FEVER. 20/ 
 
 particular ships. Old wooden ships are looked upon with 
 much greater suspicion than are the more modern ones built 
 of iron, though the latter are by no means proof against the 
 invasion of the poison. From time to time an outbreak of 
 the disease in a locality is coincident with the arrival and un- 
 loading of a ship from an infected port, notwithstanding the 
 fact that she may have had no cases of yellow fever among 
 the crew or passengers during the voyage. The disease is 
 undoubtedly conveyed by articles of merchandise, mail mat- 
 ters, clothing, and other objects that have been in localities 
 where yellow fever is epidemic. Such fomites that have been 
 in the immediate vicinity of these patients are considered 
 especially dangerous. 
 
 Though opinion is opposed to its direct transmission from 
 the sick to the well (contagion), still there are good grounds 
 for the belief that patients and convalescents have been the 
 agencies by which the disease has been carried frOm epidemic 
 or endemic centers into other localities that offered conditions 
 favorable to its development. It appears likely that the mode 
 of dissemination is analogous to that of cholera and typhoid 
 fever, and is in no wise similar to the direct transmission 
 observed in small-pox, measles, and other highly contagious 
 maladies. 
 
 Experience has shown that persons in attendance on the 
 sick are not especially liable to contract the disease, and 
 yellow-fever patients have often been brought into the wards 
 of general hospitals among susceptible patients, without the 
 disease having been disseminated. 
 
 Prophylaxis. — The most important measure against the 
 introduction of yellow fever into a locality is good general 
 sanitation, including clean and well-drained streets, proper 
 disposal of garbage and excreta, prevention of overcrowding, 
 an abundant supply of pure water for domestic purposes, 
 and a competent system of quarantine. 
 
 With the occurrence of the disease all cases should be iso- 
 lated. Their discharges, including those from the bladder, 
 bowels, and vomited matters, also all the soiled body- and 
 bed-clothing, should be carefully disinfected. The sick cham- 
 
208 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 ber should be clean and well aired. In case of death the 
 body should be wrapped in a sheet soaked in a reliable dis- 
 infectant, placed in a close coffin, and buried or cremated at 
 once. If buried, it should be in a place from which there 
 would be no danger of the pollution of neighboring water- 
 supplies. 
 
 Under the headings " Disinfection of Apartments " and 
 " Disinfection of Ships " will be found the steps necessary to 
 render quarters occupied by those patients free from danger. 
 
 DENGUE, 
 
 Definition. — A specific, epidemic, febrile disease of trop- 
 ical and subtropical countries, that is characterized by sud- 
 denness of onset, severe pains in the muscles and articula- 
 tions, the appearance of an initial and terminal rash, and by a 
 tendency to terminate favorably in from three to four days. 
 
 It is also variously known as " breakbone fever," " dandy 
 fever," "three days' fever," etc. It is certainly infectious, 
 though no micro-organism has as yet been proved to stand 
 in causal relation to it. 
 
 Its outbreak is favored by high temperature and by geo- 
 graphical location more than by any other known factors. 
 It is most apt to occur, even in the tropics, during the 
 warmest months. In higher latitudes, that are still within its 
 epidemic zone, the greatest number of outbreaks have occur- 
 red during summer and early autumn. It rarely develops 
 at a temperature below 64° F. (Hirsch), and its progress is, 
 as a rule, suddenly checked by the onset of cold weather and 
 the occurrence of frost. 
 
 It is a disease of low-lying localities along the coast, espe- 
 cially of overcrowded, unsanitary towns and cities. It rarely 
 extends into the country, and only veiy exceptionally has it 
 been observed at high altitudes. 
 
DENGUE. 209 
 
 Neither physical conditions of the soil, nor such meteor- 
 ological influences as atmospheric moisture, rain, and wind, 
 have any apparent influence upon the course and occurrence 
 of the disease so long as the temperature remains favorable. 
 
 Neither race, age, sex, nor social condition is regarded as 
 a conspicuous factor in either predisposing to or protecting 
 from dengue. 
 
 The march of the disease through a community is often so 
 rapid that from 60 to 75 per cent, of all the inhabitants will 
 be affected within a few days of its primary appearance. 
 
 By certain authors dengue is said to simulate yellow fever 
 in some respects. By others it is regarded as predisposing 
 to subsequent infection by yellow fever, cholera, typhoid, or 
 malaria. By some a single attack is thought to afford pro- 
 tection, by others this is denied. 
 
 In marked contrast to the severity of the symptoms of 
 this disease stands the rarity with which it proves fatal. It 
 is apparently dangerous for only the very young and those 
 of the aged who are already affected with grave organic 
 lesions. Many epidemics pass away with no deaths at all, 
 and even in the severest the number of deaths has " not yet 
 reached as high as 0.5 per cent, of those affected " (Scheube). 
 It is said to occur among animals (horses, cows, dogs, and 
 cats). 
 
 Dengue has been recognized as a distinct disease since 
 1824, though descriptions of an identical affection occurring 
 in Egypt, Spain, Java, and India v/ere given in the latter part 
 of the eighteenth century. During the present century it 
 has appeared on a number of occasions in India, Africa, the 
 West Indies, and southern United States. The first recog- 
 nized epidemic in this country occurred in Savannah, Ga., in 
 the fall of 1826. During the two following years it spread 
 throughout the southern States, the West Indies, and the 
 northern coast of South America. Between 1848 and 1850 
 and in 1854, widespread epidemics occurred along the Mis- 
 sissippi valley and in the southern Atlantic seaboard States. 
 The last epidemic occurred in 1873 in Alabama, Mississippi, 
 and Louisiana. The " bilious remitting fever " described by 
 
 14 
 
2IO HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 Rush in 1780, as occurring in Philadelphia, is regarded by 
 Hirsch as dengue fever. The zone of epidemicity of this dis- 
 ease is embraced between lat. 32° 47' north (Charleston, 
 S. C.) and 23° 23' south (St. Paulo, Brazil) (Hirsch). 
 
 Dissemination. — It is questionable if dengue is con- 
 tagious. At first sight, its rapid spread throughout a com- 
 munity may be attributed to a very high degree of con- 
 tagiousness. On further inquiry, however, this seems to be 
 erroneous. Like influenza, with which it is held by some to 
 be closely allied, by others to be identical, it has been 
 observed to spring up suddenly at various points in the same 
 locality among persons who have had no communication 
 with one another. Its rapid spread is therefore regarded as 
 due more to the simultaneous infection of large numbers of 
 individuals from a common focus or source, rather than from 
 the transmission of the morbific material from person to per- 
 son. Again like influenza, it is believed to be carried from 
 place to place along lines of travel by land and sea. After 
 the subsidence of an epidemic it occasionally happens that, 
 in places of suitable temperature, dengue remains endemic 
 for a time. 
 
 Prophylaxis. — As a rule, special preventive measures 
 against dengue have not been practised, probably because 
 of the comparative rarity with which the disease proves fatal ; 
 and indeed, until we possess some knowledge of its exciting 
 cause and of its mode of dissemination, it will be difficult to 
 institute a rational system of prophylaxis. The fact of its 
 sudden and simultaneous occurrence among groups of indi- 
 viduals in the same locality, who have in no known way 
 been exposed to contagion, and of the coincidence of epi- 
 demics in different places, illustrates the insidious nature of 
 its dissemination and the, for the time being, ubiquity of the 
 poison. Isolation of the sick, with disinfection of excreta, 
 clothing, and apartments, might be practised, but it is doubt- 
 ful if this would prove of any marked influence in checking 
 the march of the epidemic. 
 
TYPHUS FEVER. 211 
 
 TYPHUS FEVER. 
 
 Definition. — A specific, contagious fever characterized by 
 a maculated rash, extreme depression of the vital powers, 
 nervous derangements, and a tendency for non-fatal cases to 
 terminate by crisis in about two weeks. 
 
 It is also variously known as " spotted fever," " jail fever," 
 " camp fever," " ship fever," and " hospital fever." Its spe- 
 cific exciting cause is not known, though doubtless such a 
 factor exists. It is universally admitted that the most impor- 
 tant influences that predispose to its epidemic occurrence are 
 widespread destitution and misery, with their usual concom- 
 itants — viz., overcrowding, filth, poor and insufficient food, 
 intemperance, and inadequate clothing and shelter. 
 
 In former years epidemics of typhus fever occurred with 
 comparative frequency, both in Europe and in this country ; 
 but latterly — /. c, during the past twenty-five years — by 
 reason of the sanitary improvement that conditions of life 
 have everywhere undergone, its visitations have become fewer 
 until it has practically disappeared, as a dreaded pest, from 
 among civilized peoples. 
 
 Distribution. — The occurrence of typhus fever is not 
 markedly influenced by geographical location, though it is 
 usually regarded as more likely to occur in temperate and 
 cold than in the warmer climates, possibly because of the con- 
 ditions favorable to open-air life that the latter afford. 
 
 Its epidemic outbreak is, as a rule, referable to the pre- 
 disposing influence of the social condition of the people 
 among whom it occurs. The history of the disease, during 
 the time when it was more frequent than it is to-day, points 
 directly, as stated above, to widespread destitution and mis- 
 ery, with all that they entail, as the important factors in de- 
 termining the development of an epidemic. Up to about the 
 middle of the present century it had occurred epidemically in 
 many parts of both the eastern and western hemispheres. 
 
 Australia, New Zealand, Japan, a large part of Africa, and 
 parts of southern Europe have been comparatively free from 
 the disease. According to Hirsch, endemic centers have be- 
 
212 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 come established in only a few countries, notably in Ireland, 
 Russia, and Italy, and even here they are of but limited ex- 
 tent. Telluric and seasonal influences do not appear to be 
 of much, if any, importance in deciding an epidemic out- 
 break. 
 
 In 1883 a small epidemic of typhus fever occurred in the 
 Philadelphia Hospital, and in 1881 to 1882 over 700 cases 
 were admitted to the Riverside Hospital in New York. 
 Other than these, there have been no outbreaks of any 
 moment in this country since those that occurred between 
 1867 and 1870. 
 
 Dissemination. — Typhus fever is highly contagious, in 
 the strict sense of the word, and there is probably no disease 
 that has been more frequently contracted from patients by 
 physicians and nurses. The specific virus, of whatever nature 
 it may be, appears to be distinctly transmissible from the sick 
 to the well through the surrounding air. Whether it is usually 
 received by way of the air-passages, or through the alimen- 
 tary tract, or whether infection may occur through wounds, 
 cannot be stated, as nothing is known of the causative agent. 
 
 The poison may be harbored by and carried from place to 
 place in fomites. As stated, the activities of the specific 
 virus are favored by unsanitary conditions, and if cases of the 
 disease be introduced into overcrowded, filthy, and generally 
 unhygienic localities, there is every likelihood of an epidemic 
 outbreak of the fever. By some writers it is believed to be 
 carried from the sick to the well by insects. 
 
 The disease is less common among the very young and 
 the aged than during the periods of youth and early maturity. 
 Its occurrence is not influenced by sex. 
 
 Prophylaxis. — It is manifest that the most important 
 prophylactic measures against this fever are those that aim to 
 prevent its introduction from without, and those that are de- 
 signed to eliminate ail local conditions favorable to its devel- 
 opment. 
 
 The former comprise the functions of such properly con- 
 stituted .sy.stems of quarantine as should exi.st at all populous 
 .seaports ; the latter represent the duties of legally author- 
 
TYPHUS FEVER. 
 
 213 
 
 ized boards of health. The scope of the work should em- 
 brace the strict sanitary supervision of overcrowded localities, 
 such as exist in all the poorer districts of great centers of 
 population, and should be especially directed to the general 
 hygiene of places designed for both permanent and tempor- 
 ary residence by people of such localities — as, for instance, 
 tenement-houses, work-shops and work-houses, jails, reform- 
 atories, almshouses, and hospitals. Especial attention should 
 be given to the cleanliness, the ventilation, the condition of 
 crowding, the water-supply, and the sewage of these places. 
 Careful watch should be kept for the occurrence of suspicious 
 cases, and these should be isolated in properly equipped hos- 
 pitals as soon as detected. 
 
 The influence of fresh air upon the virulence and vitality 
 of the virus of this disease is apparently of very great im- 
 portance, and many of those who have observed the epidemic 
 outbreak of typhus fever in hospitals have been struck by the 
 rapidity of its disappearance when the patients were removed 
 from the wards and placed in tents in the open. Isolation in 
 freely ventilated apartments, and careful disinfection of bed- 
 and body-clothing and excreta are always called for. Isola- 
 tion should be rigidly enforced, because of the highly con- 
 tagious nature of the disease ; and for the same reason the 
 physician and attendants should spend no more time than is 
 necessaiy in the immediate proximity of the patient. 
 
 The sick chamber, as well as all furniture and other arti- 
 cles contained in it, should be disinfected and thoroughly 
 aired after the removal of the patient. 
 
214 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 RELAPSING FEVER. 
 
 Definition. — " Relapsing," " Famine," or " Seven Days' 
 Fever," is an infectious disease that results from the presence 
 in the blood of a specific micro-organism discovered by Ober- 
 meier and now generally known as spiroclueta Obcnncin. 
 
 The disease is characterized by acute febrile paroxysms 
 that last from six to seven days. These are followed by an 
 intermission of the same length of time, when the acute 
 symptoms reappear. It is from the occurrence of these re- 
 lapses that the fever takes its name. 
 
 The organism causing the disease is a spiral-shaped thread 
 that may be seen moving about among the corpuscles in 
 blood drawn during the paroxysms (Fig. 25). They disap- 
 
 FlG. 25. — Showing spirochseta of Obermeier in blood of relapsing fever patient. 
 
 pear from the blood until the crisis of the fever, and are but 
 very rarely to be detected during the period of intermission. 
 In dried blood preparations the spirochaeta may be stained 
 by the usual methods. It is decolorized by Gram's method. 
 It varies in length, being sometimes hardly longer than the 
 diameter of a red corpuscle, while at other times it is many 
 times this length. Nothing is known of its life hi.story. It 
 has never been reared artificially. 
 
 By inoculation with blood from these patients the disease 
 
RELAPSING FEVER. 21$ 
 
 has been induced in men and in monkeys, though in the lat- 
 ter only the primary acute fever occurs and there is no ten- 
 dency to recur. The organism has been kept alive outside 
 the human body for about a week, by keeping on ice leeches 
 that have been allowed to fill themselves with blood from 
 these patients. 
 
 The conditions that favor the development of typhus fever 
 — viz., squalor, filth, destitution, etc. — likewise favor the de- 
 velopment of relapsing fever, and the two diseases have been 
 observed together in the same locality. 
 
 Distribution. — Quoting Hirsch, the first trustworthy 
 account that we have of this disease on European soil is 
 given by Rutty in 1 770 in his chronological history of the 
 prevailing diseases of Dublin. In this publication he directs 
 attention to an epidemic of this fever that occurred in Dub- 
 lin in 1739. The fever has been more prevalent in Ireland, 
 Scotland, Russia, parts of Germany, northern Africa, and 
 India than elsewhere. It had not appeared in Australia up 
 to 1875. It was first observed in this country, in Philadel- 
 phia, in 1844. It has not appeared in the United States in 
 epidemic form since 1869, when it prevailed extensively in 
 New York and Philadelphia. 
 
 It is not apparently influenced by age, sex, season, or tel- 
 luric conditions, though it is said to have occurred more fre- 
 quently in the temperate and cold than in warm climates. 
 
 Dissemination. — It is said to be contagious, though less 
 so than is typhus fever. Latterly, attention has been directed 
 to the possibility of its being spread from the sick to the well 
 by the bites of insects — a reasonable opinion in view of the 
 fact that the disease may be induced through the inoculation 
 of healthy persons with blood from those suffering from the 
 fever. 
 
 The causative agent is said to be transmissible by fomites. 
 
 Prophylaxis. — Since the social conditions that favor the 
 development of typhus likewise favor the development of 
 relapsing fever, the prophylactic measures recommended for 
 the former serve equally well for the latter disease. 
 
2l6 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 RABIES. 
 
 ( Lyssa ; Hydrophobia. ) 
 
 Definition, Cause, etc. — A specific infectious disease 
 communicable from animals to animals and to man, com- 
 monly by a bite. 
 
 When occurring in animals it is known as rabies or lyssa ; 
 when in man, as hydrophobia, not because of the actual fear 
 of water, as the name signifies, but rather because of the 
 dread felt by the patient of the severe spasm of the muscles 
 of deglutition that is experienced in efforts to swallow water. 
 
 In the rabid animal the virus of the disease is contained in 
 the saliva, and it is through wounds made with the teeth, or 
 wounds to which saliva from such animals gains access, that 
 rabies is transmitted. 
 
 Numerous efforts have been made to detect the etiological 
 factor of rabies, but as yet no trustworthy results have been 
 reached. Nevertheless, it has been demonstrated that a 
 poison is present in the tissues of animals suffering from or 
 dead of the disease — especially in the tissues of the central 
 nervous system — that is capable of setting up the disease in 
 other animals into which may be inoculated. Though the 
 actual cause of rabies has not been detected, still, the behavior 
 of the tissues that are particularly rich in the poison corre- 
 sponds in so many ways with that of tissues containing a 
 living virus as to leave little doubt that the disease originates 
 with the invasion of a specific micro-organism, or the intro- 
 duction of a poison resulting from the development of such 
 an organism. Thus, for instance, the poisonous properties 
 of the medulla are destroyed in a few minutes by exposure to 
 50° C, by subjection to various disinfectants, by prolonged 
 action of sunlight, and by drying, all of which reactions, as 
 we know, are common to tissues containing living micro- 
 organisms. 
 
 The animals most frequent!}' affected are dogs, wolves, 
 cats, jackals, and skunks, though the di.sease is transmissible 
 to horses, bovines, swine, sheep, deer, etc. When once well 
 established, the di.sease is almost invariably fatal. The dog 
 
RABIES. 
 
 217 
 
 is the chief sufferer from rabies, and is the principal, if not the 
 sole, means of its propagation (see Table XI.). 
 
 Table XI. — Compiled by Fleining, giving the number of cases of 
 rabies, and the species of animal in wliicli they occurred, in 
 England during the four years ending with i8go .•' 
 
 Kind of Animal. 
 
 Dogs . . . 
 
 Cattle . . 
 
 Sheep . . 
 
 Swine , , 
 
 Horses . . 
 
 Deer . . . 
 Total 
 
 IS37. 
 
 1888. 
 
 1S89. 
 
 1890. 
 
 129 
 
 217 
 
 160 
 
 312 
 
 II 
 
 2 
 
 9 
 
 2 
 
 5 
 
 7 
 
 II 
 
 
 3 
 
 
 4 
 
 I 
 
 4 
 
 5 
 
 4 
 
 2 
 
 257 
 
 2 
 
 
 
 497 
 
 176 
 
 340 
 
 134 
 
 Rabies is communicable to man, as stated, by the bite of a 
 rabid animal. Bites received upon exposed surfaces, as upon 
 the head, face, and hands, are usually more serious and more 
 <:ertain to be followed by hydrophobia than are those upon 
 the clothed portions of the body, owing, doubtless, in the 
 latter case, to the virus being wiped from the teeth in their 
 passage through the clothing. 
 
 The period of incubation of hydrophobia ordinarily varies 
 from about six weeks to two months, according to circum- 
 stances. In some cases it is shorter — as short as two weeks ; 
 in others it may be delayed for a year or more after the 
 reception of the bite. The bite of the rabid wolf and cat is 
 more certain to be followed by hydrophobia than is that of 
 the dog. 
 
 The fatality among individuals bitten by dogs proven to 
 Jiave rabies is in general 15 per cent., while for those cases in 
 which the bites were received upon exposed surfaces the 
 figure rises to from 60 to 80 per cent. No country is exempt 
 from rabies except, perhaps, Australia and New Zealand 
 (Fleming), and it is excluded from those places only through 
 a careful quarantine of all dogs coming into the country. 
 
 It is more prevalent in some countries than in others, 
 
 ^ See Fleming: "The Propagation and Prevention of Rabies," Trans. 
 .Seventh Internat. Cong. Hygiene and Demography, 1891, vol. iii., p. 16. 
 
2l8 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 owing in part to the stringency of dog laws in localities 
 where it is rare, and the laxity or absence of such laws from 
 those places in which it is more common. 
 
 Rabies is especially prevalent in Russia, Belgium, Austria^ 
 France, and England. It is rare in Germany and Switzer- 
 land, because of the regulations governing dogs, and for 
 some reason or another it is not very common in this coun- 
 try. The cases seen in Germany have, in the majority of 
 instances, been in the provinces along the Russian border. 
 
 Since the dog is the most frequent sufferer from this dis- 
 ease, and the commonest source from which hydrophobia is 
 contracted by human beings, it is manifestly important that 
 it should be recognized in its earliest stages. 
 
 Symptoms. — A dog bitten by another that is mad may 
 show signs of rabies within a few days — ten to fifteen — or, as 
 in latent rabies, evidence of the disease may not appear for 
 months. The symptoms of rabies in the dog warrant the 
 division into " furious " or " excitable," and " paralytic " or 
 " dumb " rabies, though sharp lines of distinction cannot 
 always be drawn. After the earliest signs of madness, that 
 usually manifest themselves by quietness, sullenness, dis- 
 inclination for company, alterations in the general psychical 
 nature, perverted appetite, and conspicuous alteration in 
 voice, the animal may become markedly excited or furious^ 
 or paralysis may set in. If the former, he will often trot 
 about over large tracts of country, with head and tail de- 
 pressed, tongue hanging from the jaws, and snapping ^ at all 
 objects that come in his way. It is in this stage that the dog 
 is most dangerous to other animals. 
 
 From loss of food and sleep and excessive nervous excite- 
 ment the animal rapidly becomes emaciated and haggard. 
 Death usually results in a convulsion, of which the dog may 
 have many toward the later stages of the disease. 
 
 If the disease assumes the paralytic form, there is usually 
 no period of excitement ; but after the preliminary symptoms 
 evidences of paralysis, beginning with the muscles about the 
 
 'Responsible authors do not regard the "snapping" as deliberate, but 
 rather as reflex. 
 
RABIES. 219 
 
 face and jaws — especially of the lower jaw — are observed. 
 Paralysis is progressive until the death of the animal. 
 
 While the clinical aspects of these manifestations of rabies 
 are totally dissimilar, they are still regarded as etiologically 
 identical, and do not therefore constitute distinct diseases. 
 
 The mode of diagnosing rabies that is now regarded as the 
 most trustworthy is only possible after the death of the ani- 
 mal, but even then it is manifestly often of the utmost impor- 
 tance to know definitely the nature of the malady, in the 
 event of the dog's having bitten persons or other animals. 
 
 This method of diagnosis consists in the introduction of a 
 small portion of the medulla from the mad dog beneath the 
 dura mater of a rabbit. After a period of incubation of from 
 twelve to eighteen days, the rabbit evinces beginning paraU 
 ysis ; this is progressive until death. The form of rabies 
 thus transmitted to the rabbit is always paralytic, though 
 the same material may be capable of inducing either the 
 furious or the paralytic -A^ariety in dogs inoculated in a simi- 
 lar manner. By the repeated transference of bits of medulla 
 from one rabbit to another, by this mode of inoculation, the 
 disease may be propagated at will. 
 
 Prophylaxis. — The statistics on this disease from differ- 
 ent countries, without exception, demonstrate that adequate 
 laws concerning the keeping of dogs, when properly enforced, 
 constitute the most potent factor for its suppression. Such 
 regulations should provide for : 
 
 The immediate destruction of all dogs known or believed 
 to be suffering from rabies, and the secure isolation and care- 
 ful observation of all animals that may have been bitten by 
 such dogs. 
 
 The seizure and destruction of all vagrant dogs. 
 
 The imposition of a tax upon the owners of dogs, and 
 the punishment by fine of all persons detected in evading 
 this tax. 
 
 During the prevalence of rabies, and for a time afterward 
 equivalent to the longest period of latency, all dogs should be 
 muzzled. The non-observance of this provision on the part 
 of the owners to be punishable with fine. 
 
220 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 There are numerous instances in which the adoption of 
 such regulations has caused, within a short time, the almost 
 total disappearance of rabies from neighborhoods in which it 
 prevailed. Thus, for instance, there were 107 mad dogs 
 killed in Berlin during an outbreak of the disease in 1852; 
 on July 2, 1853, a decree was issued to the effect that all 
 dogs should be muzzled, and all not so secured should be 
 killed ; in the year following this decree there was only one 
 dog destroyed as rabid. It was subsequently found necessary 
 to extend this decree to the whole of Prussia, as the muzzling 
 and destruction of dogs in Berlin alone were not sufficient to 
 eradicate the disease totally. 
 
 Within eighteen months after the adoption of the muzzling 
 law in Vienna rabies was totally suppressed. In the Grand 
 Duchy of Baden the numbers of cases of rabies that occurred 
 annually, from 1871 to 1875 inclusive, were 18, 37, 50, and 
 43. In 1876 the muzzle was applied, with the following 
 results : in 1876 there were 28 cases ; in 1877, 3 ; in 1878, 4; 
 in 1879, 2; in 1880, 2; in 1881, 2; in 1882, 3; in 1883, 2; 
 in 1884, 2. 
 
 In Prussia preventive measures have reduced the deaths 
 from hydrophobia in human beings from a yearly average of 
 166 cases for the- ten years ending with 1879, to a yearly 
 average of 4.5 cases for the decade ending with 1886. 
 
 The foregoing statistics, taken from Fleming's paper, re- 
 ferred to above, while representing only a portion of the 
 material presented by him in support of his argument for 
 the suppression of rabies, are still sufficient for our purpose 
 to demonstrate what may be accomplished by intelligent and 
 conscientious attention to this important subject. 
 
 Preventive Inoculation. — The principles involved in 
 the practice of preventive inoculations against rabies and 
 hydrophobia are essentially those on which all other modes 
 of preventive inoculation are based ; that is to say, they con- 
 template the establishment in the animal under treatment of 
 a tolerance to the virus of the particular disease from which 
 it is being protected. Tliis is usually accomplished by the 
 repeated inoculation of doses of the virus that are so small, 
 
RABIES. 221 
 
 or of virus so attenuated in potency, as not to imperil the life 
 of the animal, beginning usually with very minute doses and 
 gradually increasing them until the animal can finally with- 
 stand, without injury, what would otherwise be a fatal dose 
 of the fully virulent virus. When this point is reached, the 
 animal is protected. In the majority of instances the protec- 
 tion thus afforded is believed to be due to specific systemic 
 reactions, following upon each injection, by which the tissues 
 acquire a tolerance to the poisonous properties of the mate- 
 rials used. In this particular instance, as indeed in all 
 others, the essential starting-point is a virus of fixed and 
 known toxicity. 
 
 The virus obtained from the medulla of a dog dead from 
 the ordinary rabies of the street (" rage des rues "), when 
 inoculated into a rabbit, has a period of incubation of from 
 fifteen to twenty days, rarely or never less than eleven days. 
 By passing such virus from rabbit to rabbit through a long 
 series, the incubation period becomes gradually shortened 
 until it finally reaches a fixed point of from six to seven days 
 (" virus fixe "). As a rule, this is the strongest and most 
 stable virus that can be obtained. 
 
 If the medulla from a rabbit that has died after inoculation 
 with this fixed virus be preserved in a dry atmosphere, its 
 toxicity gradually becomes lessened as the drying proceeds, 
 and totally disappears in about two weeks if the drying has 
 been at a temperature of from 23° to 25° C. With the me- 
 dulla so treated the period of incubation, as determined by 
 the inoculation of rabbits, becomes longer as the virus be- 
 comes attenuated in the degree of its potency. In Pasteur's 
 protective inoculation, the treatment is begun with the subcu- 
 taneous injection of emulsions of spinal cords or medullae 
 that have been thus dried until almost robbed of their toxic 
 properties ; this is followed by similar injections of emulsions 
 from more and more toxic tissues, until finally the animal is 
 prepared for an injection with the strongest — i. e., " fixed 
 virus ; " when this stage is reached, protection is assumed to 
 be completed. 
 
 For the successful employment of this method it is essen- 
 
222 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 tial that it be begun at the earliest possible moment after the 
 reception of the virus — i. c, after the bite of the rabid ani- 
 mal. The greater the delay the less likely is the treatment to 
 be effectual. 
 
 The influence of this mode of treatment upon the mortal- 
 ity from hydrophobia among human beings bitten by rabid 
 animals is so striking as to efface all question as to its efficacy. 
 As stated above, a fair average mortality for all cases of bites 
 from mad animals is 1 5 per cent., while the mortality among 
 those bitten upon the head, face, neck, and hands, ranges 
 from 60 to 80 per cent. The following table, compiled by 
 Pottevin, illustrates the striking reductions in these death- 
 rates that have been accomplished through this mode of treat- 
 ment in the Institute Pasteur at Paris. 
 
 Table showing the results of the Pasteiirian preventive inoculation 
 against hydrophobia in human beings, for the twelve year's 
 endi?ig with iSgj :^ 
 
 Years. Persons treated. Deaths. Mortality 
 
 (per cent.). 
 
 1886 2671 25 0.94 
 
 1887 1770 14 0.79 
 
 1888 1622 9 0.55 
 
 1889 1830 7 0.38 
 
 1890 1540 5 0.32 
 
 1891 1559 4 025 
 
 1892 1790 4 0.22 
 
 1893 1648 6 0.36 
 
 1894 1387 7 0.50 
 
 1895 1520 5 0.33 
 
 1896 1308 4 0.30 
 
 1897 1521 6 0.39 
 
 'See Les Vaccinations Antirabiqiics a f Inslitiit Pasteur en iSgj, par 
 Henri PcHtevin ; Amtales de I' Institut Pasteur, 1898, tome xii., p. 301. 
 
DISEASES DUE TO ANIMAL PARASITES. 223 
 
 DISEASES DUE TO HIGHLY-DEVELOPED ANIMAL 
 PARASITES. 
 
 It is manifestly inadvisable to attempt in a book of this 
 character the detailed treatment of so large a subject. The 
 following must, therefore, be regarded as a mere sketch of 
 the more frequent and important conditions observed in man 
 as a result of the invasion of the body by the commoner ani- 
 mal parasites. 
 
 As has been already intimated in the first section, the dis- 
 turbance of physiological function and the morbid conditions 
 that arise from the presence of entozoa in the body are in the 
 main due to their character, mode of development, their local 
 irritation, to the demands that they make upon the blood and 
 tissues for nutrition, and to their obstructive action when lo- 
 cated in important viscera and organs of special sense. With 
 the exception of the blood-sucking ankylostonia dtiodenale, 
 those that occupy the alimentary tract cause only disturbances 
 of the digestive processes and reflex nervous phenomena, and 
 are not accompanied by definite or serious structural lesions. 
 Those located within the tissues cause irritation which may 
 in time be followed by more or less of inflammatory reaction. 
 Certain of these, by developing to an unusual size (echino- 
 coccus cyst), may seriously obstruct the functional activity of 
 the organ in which they are located ; while those occupying 
 a position in such important vital parts as the central nervous 
 system, the organs of special sense, and the circulatory ap- 
 paratus, may result in the gravest disturbances, and even in 
 death. 
 
 Diseases of this class, and especially those in which the 
 parasite resides within the alimentary tract or internal viscera, 
 are most frequently contracted through the swallowing of 
 either the mature parasite or its eggs, or its larval forms. 
 
 As a rule, the commonest worms of man enter the body as 
 larvae with the flesh of animals in which the first stages of 
 development of the worm have taken place ; or in some in- 
 stances they may be derived directly from domestic animals 
 whose flesh is not used as food, but with which the individual 
 
224 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 may have been in intimate association ; or in other cases they 
 may be traced to the eggs of parasitic worms that are con- 
 tained in polluted drinking water. 
 
 The Nematoda. — These worms are so called because 
 of their filiform or thread-like shape. The commonest spe- 
 cies are : 
 
 Ascaris Lumbricoides {Round WoriJi). — It is in general 
 similar in appearance to the ordinary earth-worm. The fe- 
 males measure about 30 cm. (12 inches), and the males about 
 1 5 cm. (6 inches) in length. It locates in the small intestine 
 of man, and, as development proceeds, a large number of 
 eggs are passed. The eggs are brownish in color, as seen in 
 the stools, and are of a barrel shape. The eggs are carried 
 by water, and it is through the drinking of water polluted with 
 them that the individual often becomes infected. The worm 
 is also seen in swine, and for this reason water polluted with 
 hog excrement should be viewed with suspicion. 
 
 Oxyuris Vermicularis {Thread Worni). — This worm in- 
 vades the cecum and upper colon. The female, which is 
 about 12 mm. in length, deposits eggs in very large numbers. 
 Within these eggs spermatozoa-like embryos may often be 
 detected. When swallowed, the envelope of the embryo is 
 digested by the gastric juice and the larvae liberated. They 
 pass through the early developmental stage in the upper in- 
 testine and reach maturity in from twenty -five to thirty days. 
 Raw vegetables or insufficiently cooked vegetables are said 
 to be the most frequent source of infection. The larvae are 
 destroyed by long immersion in water. 
 
 Trichocephalus dispar {ivliip-zuonri) is the commonest 
 intestinal parasite of man in tropical latitudes. It retains its 
 vitality in water and in moist soil. The embryos in the Qgg 
 are very tenacious of life. When the o.^^ is swallowed, the 
 larva is liberated in the alimentary canal, attaches itself to 
 the wall of the intestine by its lash-like extremity, and pro- 
 ceeds to develop slowly, reaching maturity after about ten or 
 twelve months. 
 
 Ankylostoma duodenale is a minute worm, which by its 
 presence in the upper portion of the small intestine causes 
 
DISEASES DUE TO ANIMAL PARASITES. 22$ 
 
 the disease called ankylostomiasis, or Egyptian chlorosis^ 
 The parasite becomes attached, often in enormous numbers, 
 to the villi of the duodenal mucous membrane. Through 
 the continuous draught that it makes upon the circulating 
 blood there results the condition of anemia by which the dis- 
 ease is characterized clinically, and from which it takes its 
 popular name. The parasite is apparently widely distributed, 
 as the disease has been observed in Egypt, India, Italy, 
 Africa, Peru, and Australia. An analogous disease, known 
 as " miners' cachexia," " miners' chlorosis," " tunnel disease," 
 has been observed among Italian workmen in the St. Goth- 
 ard tunnel. It has also been known among Italian brick- 
 makers and in those who have worked upon the irrigation 
 fields. The disease is said to have been known for some 
 years among the coal miners of Belgium and the brick- 
 makers of Cologne as " brick-makers' anemia." The devel- 
 opment of this parasite seems to be favored by wet, marshy 
 soil. In appearance the parasite is whitish or brownish in 
 color, and in shape it is cylindrical, with more or less pointed 
 ends. It measures from 6 to i8 mm. long and about i mm. 
 in thickness. The male has a bell-like expansion at its 
 posterior extremity. It attaches itself, as said, to the mucous 
 membrane of the duodenum and upper jejunum, by means 
 of a set of tooth-like hooks with which the mouth is pro- 
 vided. The eggs of this parasite are ejected with the feces, 
 and probably undergo further development when favorable 
 conditions, such as soil-moisture, high temperature, and free 
 access to air, exist. 
 
 Infection probably occurs through the drinking of water 
 from marshy soils on which the eggs are deposited with the 
 feces of individuals in whom the entozoon is present, or in 
 some one or another of the manifold ways that are open to 
 men working in and upon such infected areas. It is almost 
 exclusively seen in persons whose occupations bring them in 
 contact with earth, as the various synonyms of the disease 
 imply. 
 
 It is obvious that the precautions to be taken to prevent 
 infection and dissemination are to drink only boiled or fil- 
 ls 
 
226 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 tered water, pay particular attention to personal cleanliness, 
 especially of the hands, and to disinfect carefully the stools 
 from all individuals in whom the parasite is present. 
 
 Rhabdonema Intestinale. — Frequently associated with 
 ank)-lostoma duodenale is the nematode rliabdoncma intes- 
 tinale, the parasite that is concerned in the causation of the 
 so-called " diarrhea of Cochin China." 
 
 The lodgement of the female worm, which is about 2 mm. 
 long and hardly thicker than a hair, in the intestinal tract is 
 quickly followed by a brood of embryos that are hatched 
 from eggs in the canal. The embryos bear some resem- 
 blance to those of ankylostoma, but differ from them in 
 being hatched while in the human host. 
 
 The presence of this parasite in large numbers is account- 
 able for a persistent diarrhea so often observed in Cochin 
 China, Brazil, West Indies, Egypt, Ceylon, Italy, and other 
 tropical countries. 
 
 In marked cases of the disease the daily extrusion of the 
 worms, which accumulate in all parts of the intestinal canal, 
 is said to reach enormous numbers, having been estimated at 
 100,000. 
 
 The disease is contracted in the same way as is anky- 
 lostomiasis, and the precautions that are recommended to be 
 taken against the one serve equally well against invasion by 
 the other parasite. 
 
 Dracunculus medinensis (^filarici medinensis, or Guinea- 
 worm) productive of the condition known as draeontiasis. 
 
 This is a nematode which in the mature form may meas- 
 ure from 60 to 80 centimeters (24-30 inches) in length 
 and from 0.8 to 2 mm. (0.03-0.08 inch) in thickness. It 
 enters the body, most probably by the mouth, as an 
 embryo or larva contained in the body of the fresh-water 
 flea, Cyclops. On reaching the stomach the enveloping 
 -Structures are digested and the embiyo liberated. Rapid 
 development now begins, and on reaching sexual ma- 
 turity the adult worms proceed to reproduce. After im- 
 pregnation the female wanders from the alimentary tract 
 toward the subcutaneous tissues, where she remains for a 
 
DISEASES DUE TO ANLMAL PARASITES. 22/ 
 
 time until she finally breaks through the skin, causing a 
 point of ulceration or abscess-formation. The male worm 
 disappears after having performed his function of fecunda- 
 tion. On being discharged from the body, either by the 
 breaking of an abscess or through the open surface of an 
 ulcer that results from her presence in the subcutaneous tis- 
 sues, the female worm is literally packed with living embryos. 
 These find their way into water and, as stated, find in the 
 Cyclops an intermediate host favorable to their perpetua- 
 tion. 
 
 The disease dracontiasis, or, as it is commonly called, 
 Guinea-worm disease, and the parasite causing it, have been 
 known for a very long time. Historians tell us that there 
 are rehable records of it dating as far back as 150 b. c. 
 Indeed, the reference made in the fourth book of Moses 
 (Numbers, Chap, xxi, verse 6) to " the fieiy serpents " with 
 which the children of Israel were affected during their forty 
 years' wandering in the wilderness has been interpreted as 
 relating to this parasite. 
 
 The Guinea-worm is encountered in many parts of the 
 Orient ; on the west coast of Africa ; in southern America, 
 particularly Guiana, Brazil, and certain of the islands of the 
 Spanish-American group. Occasionally dracontiasis is seen 
 in this country, but it is usually imported, though a case is 
 reported by van Harlingen in a man who had never lived 
 outside of Philadelphia. 
 
 It is interesting to note that in the majority of cases of this 
 disease the parasite is detected, as a rule, in a locality as far 
 removed as possible from the point of entrance into the body. 
 Thus, for example, of 712 reported cases of the disease that 
 have been compiled by Hirsch, the parasite broke through 
 the skin of the foot or lower part of the leg in 641 cases. 
 
 From what has been said it is obvious that the measures 
 to be taken against contracting and disseminating the disease 
 are to drink only boiled water when in neighborhoods where 
 the parasite is indigenous, and to burn the worm and dress- 
 ings from the ulcer or abscess as soon as removed. 
 
 Filaria Sanguinis Hominis {Filariasis). — Under this head 
 
228 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 reference is made to a nematode encountered in the tropics — 
 especially in Brazil, Central America, Egypt, India, and 
 China — that invades the human body and is associated with 
 chyluria, hematochyluria, and elephantiasis. 
 
 The life history of this parasite, for much of our knowledge 
 of which we are indebted to the studies of Patrick Manson, 
 of Brisbane, is, like the filaria medinensis and other filariae, 
 not completed in a single host. 
 
 The embryonic filarise probably gain access to the body 
 through the drinking of stagnant or polluted water in which 
 they have been deposited by the mosquito, now regarded as 
 the intermediate host. 
 
 Upon entry into the alimentary canal the young filariae 
 bore through the mucous membrane and take up their abode 
 in the deeper lymphatics. When mature, the female worm, 
 which is, according to Manson, about 3 inches long and 
 about YTo irich in thickness, is seen to be packed with em- 
 bryos in all stages of development. These wander from the 
 parent into the circulating blood and appear as tiny, actively 
 moving, almost homogeneous worms that are readily detected 
 by their lashing movement when a drop of blood containing 
 
 Fir;. 26. — Filaria sanguinis hominis nocturna. Magnified about 200 diameters, 
 showing relative size to the corpuscles of the blood 
 
 them is examined under the microscope (see Fig. 26). They 
 are about 37--^,^ inch in diameter and from -^-^ to -^ inch in 
 length.' At this point their development in man cea.ses, and 
 
 ' See illustrated paper by Henry : Trans. Assoc, .liii. Phys., 1896, vol. xi., 
 page 96. 
 
DISEASES DUE TO ANIMAL PARASITES. 229 
 
 can only progress further by the intervention of another ani- 
 mal that serves as an intermediate host. This, Manson be- 
 lieves, is the mosquito, which in sucking the blood from an 
 infected person takes up the embryo filarise, to deposit them 
 subsequently in water, from which the cycle here outlined 
 may be repeated. One of the most interesting features of 
 this nematode is the periodicity of its excursions from the 
 parent, or from the deeper lymphatics into the more super- 
 ficial blood-channels, and owing to variations in this respect 
 three different filariae sanguinis hominis are recognized — viz., 
 f. s. h. noctiima — /. e., those that are to be found in the super- 
 ficial blood-vessels only during the sleeping hours at night ; 
 f. s. h. dhirna — /. c, those found in the circulating blood only 
 during the day ; and / s. Ji. perstans — /. c, those that persist 
 in the circulating blood throughout the twenty-four hours. 
 
 The interesting experiment of Mackenzie demonstrated 
 that with at least one of these varieties — namely, /. s. h. 
 nocturiia — its habits vary with the habits of the individual 
 in whom it is present. That is to say, they can be made to 
 appear during the day and disappear during the night, by 
 having the patient sleep during the day and remain awake 
 during the night hours, just the reverse of their habits under 
 normal conditions of waking and sleeping. 
 
 This parasite, as stated, is indigenous to several localities 
 in the tropics. A sufficient number of cases have been 
 reported in the United States, however, to justify the opin- 
 ion that it must be regarded as a parasite that occasionally 
 makes its appearance in the southern and middle States of 
 this country, even in individuals who have not resided out of 
 these localities. 
 
 The clinical phenomena observed in individuals infected 
 with this parasite are chyluria, hematochyluria, and ele- 
 phantiasis, especially of the scrotum. From time to time 
 persons are encountered who are serving as hosts for this 
 parasite, who are apparently in health and who evince no 
 external evidence whatever of its presence, beyond the pass- 
 age of chylous urine. 
 
 The chylous and hematochylous urine and the lymph- 
 
2:;0 
 
 IIYGIEXE OF TRANSMISSIBLE DISEASES. 
 
 scrotum are apparently the result of obstruction of lym- 
 phatic vessels either by the adult worm or by numbers of 
 the embryos. 
 
 Trichina Spiralis (^Trichinosis). — Within the muscles of 
 animals infected with this parasite are to be seen tiny, opaque 
 oval crystals measuring from 0.3-0.4 mm. (0.01-0.015 inch) 
 in length and 0.12-0. 15 mm. (0.005-0.006 inch) in breadth, 
 
 Fig. 27. — Trichina spiralis in muscle (under low magnifying power). 
 
 in which are spirally coiled, very small worms that can only 
 be detected with the microscope (Figs. 27 and 28). 
 
 These bodies represent the embryonic stage of trichina 
 spiralis. When swallowed the enveloping cyst is digested 
 
 Fig. 28. — Trichina spiralis in muscle: a, in the early stages; b, capsule calcified 
 (after Leuckart). 
 
 and the embryo liberated. It at once begins to develop and 
 reaches sexual maturity in the intestinal canal after from five to 
 .six days. It is then white, of about the thickness of a hair and 
 approximately 3 mm. (o. 1 2 inch) in length. The male worm, 
 which is the shorter of the two, measures from 1.5 to 2 mm. 
 (0.06-0.08 inch) in length. 
 
 With sexual maturity the female worm begins to procreate 
 
DISEASES DUE TO ANIMAL PARASITES. 23 1 
 
 her species, giving off from 1000 to 1500 embryos as a brood, 
 which at once begin to pass through the intestinal walls into 
 the general musculature by way of the lymphatic channels. 
 They penetrate the primitive muscular fibers, light up a lim- 
 ited inflammatory reaction, and become encysted. The cyst- 
 wall or capsule gradually thickens and finally, in from six 
 weeks to two months, becomes calcified (see Fig. 28, E). In 
 this condition they appear as opaque, whitish, lens-shaped 
 bodies lying among the muscle-fibers. 
 
 In the encapsulated condition the embryo may lie dormant 
 in the muscles for a long time, " as long as twenty-five years 
 after their entrance into the system." 
 
 It is of importance to remember that of the domestic ani- 
 mals whose flesh is used for food, the hog is the one by far 
 the most frequently affected with this parasite, though it has 
 occasionally been observed in the calf and sheep (see Fig. 29). 
 
 F:it 
 
 Man 
 
 Ho 
 Fig. 29. — Life cycle and intermediate hosts of trichina spiralis (after Bollinger). 
 
 While the presence of trichin?e in the muscles of hogs 
 causes apparently little inconvenience to the animal, their 
 dissemination through the body of man in the disease trichi- 
 nosis is followed by marked constitutional disturbances and 
 not infrequently by death. 
 
 During the period in which the worm is confined to the 
 intestinal canal the symptoms observed in man may be prac- 
 tically null in some cases. In others loss of appetite, diar- 
 rhea, and vomiting may occur. With the emigration of the 
 embryos from the intestine to the muscles there appear fever, 
 
232 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 depression, severe pain, and edema in and about groups of 
 affected muscles. Involvement of the diaphragm, intercostal 
 muscles, and those of the larynx causes distressing dyspnea 
 that may prove fatal. 
 
 This parasite is observed in the flesh of hogs, cats, rats ; 
 less frequently in calves, sheep, dogs, mice, foxes, porcupines, 
 and hedgehogs. Guinea-pigs and rabbits may be infected by 
 feeding them with trichinous flesh. 
 
 They are readily detected, when present, in thin bits of 
 muscle, by the use of a magnifying power of from 40 to 60 
 diameters. The muscles and tissues that contain them in 
 greatest numbers are the tongue, laryngeal muscles, muscles 
 of the jaw and loin, intercostals, and the lungs. It is espe- 
 cially at the tendinous insertion of these muscles that they 
 congregate in greatest numbers. The search for them is 
 greatly facilitated by cutting very thin strips from the sus- 
 pected muscles, placing them between two heavy glass slides, 
 which are to be pressed together firmly and examined with a 
 power of 40 to 60 diameters. Calcified trichinae may be ren- 
 dered transparent by treatment with dilute acetic or hydro- 
 chloric acid. 
 
 Tric'iinae are destroyed by heat (above 65° C.) in a few 
 minutes, by drying in a short time, and by pickling in about 
 two months. They are not killed by the ordinary process 
 of smoking meat, and not certainly by as low a temperature 
 as 20° to 25° C. 
 
 Infection occurs, therefore, commonly through the inges- 
 tion of raw meat or meat that has not been subjected to a 
 sufficiently high temperature for a time necessary to kill the 
 parasite. 
 
 The ratio between trichinous and healthy hogs slaugh- 
 tered at the Berlin abattoir, between the years 1885 and 1895, 
 was .seen to vary annually from 0.22 per looo to 0.88 per 
 1000. During the past few years there has been a gradual 
 diminution in the number of cases. Up to 1884 the statistics 
 compiled by Salmon for trichinae among hogs showed the 
 disease to be present in a little over 2 per cent, of American 
 swine, though official observations made since that date show 
 
DISEASES DUE TO ANIMAL PARASITES. 233 
 
 the disease to be growing less common. Of 1000 hogs ex- 
 amined by Osier and Clements in Montreal, in 1883, the 
 disease was present in 0.4 per cent. 
 
 Cestodes {TcsnicE). — Another group of parasites, the ces- 
 todes or tape-worms, announce their presence in the body by 
 mild constitutional symptoms, such as nervous irritability, 
 indigestion, etc., but more especially by the appearance in 
 the stools of the affected individual of segments of the adult 
 worm. 
 
 There are several varieties of cestodes, the most important 
 of which are tcBuia soluivi, or pork tape-worm ; tcenia sagi- 
 naia, or bovine tape-worm ; and bothriocephalus latits, a tape- 
 worm, rare in this country, that has been observed in particu- 
 lar species of fresh-water fish, especially the pike. As a 
 rule, tape-worms are not dangerous to their host ; they are 
 readily eliminated by treatment, and easily guarded against 
 by simple prophylaxis. 
 
 The tape-worms may be regarded as colonies of zooids, 
 the individuals of which are strung together in single file, 
 which gives to them the appearance of a bit of tape. The 
 head is simply one of the group of zooids that is provided 
 with either suckers or booklets, which enable it to make fast 
 to some portion of the intestine, and thus support from this 
 fixed point the entire organism. The zooids or proglottides 
 — /. e., the segments of a tape-worm — are so constructed that 
 they may each be regarded as a sexually complete organism. 
 
 A fully developed tape-worm ordinarily consists of about 
 1000 proglottides, which are computed to give birth annu- 
 ally to approximately 1 20,000,000 eggs, only a very small 
 proportion of which, fortunately, come to maturity. 
 
 Man becomes infected with these parasites by swallowing 
 the ova from ripe segments of the w^orm. The results of 
 swallowing the ova may be either the development of a sexu- 
 ally mature worm in the intestine, or the permeation of the 
 muscles and viscera by the larva — cysticcrci — that remain as 
 such because of their incapacity to advance to sexual matur- 
 ity in these localities. In the former case there is little 
 danger, while in the latter the conditions produced may or 
 
234 
 
 HYGIENE OE TRANSMISSIBLE DISEASES. 
 
 may not be serious, depending upon whether the cysticerci 
 are deposited in important vital organs or not. 
 
 The commonest tape-worms that are found in the intestine 
 are the pork tape-worm, the beef tape-worm, and the botluno- 
 cepliahis lahis, especially the former two ; while the visceral 
 manifestations of these parasites are usually due to the per- 
 meation of the tissues and organs by the larva of tcenia 
 solium — /. c, by the cysticcrciis celluloses and the larva of 
 tcenia ecliinococciis. 
 
 Taenia Solium {Pork Tape-zvorni). — This parasite is less 
 common in America than in Europe. It occurs in man as a 
 result of eating raw or imperfectly cooked pork, or food con- 
 taminated with the ova from the mature worm. 
 
 The mature tcBuia soliinn measures about three or four 
 meters in length, and consists of about 800 proglottides, only 
 
 Fk;. 30. — Tnenia solium (after Leuckart). 
 
 about the terminal eighth of which are sexually mature. Its 
 head is small, about the size of a pin-head, and is provided 
 with four sucking-disks and a circlet of from twenty-five to 
 twenty-eight sharp hooklets, by which it attaches itself to the 
 wall of the intestine {V'\g. 30). 
 
DISEASES DUE TO ANIMAL PARASITES: 235 
 
 The eggs of this worm are expelled with the dejecta of 
 the affected person. They are nearly round, and are encased 
 in a firm shell covered with minute rods. On being extruded 
 the eggs develop no further, unless, as is most frequently the 
 case, they are taken up by either man or the hog. In the 
 latter event the embryo passes into the voluntaiy muscles of 
 the animal, and becomes metamorphosed into the bladder- 
 worm, or cysticcrciis cclliiloscB (Fig. 31), there to remain until 
 
 Fig. 31. — Cysticerci cellulosse : i, 2, 3, developmental forms ; 4, in muscle (after 
 
 Leuckart). 
 
 it ultimately dies or until it passes into the stomach of man 
 with the flesh of the animal that is eaten as food. On reach- 
 ing the stomach of man it develops into a mature tape-worm 
 identical to that from which its life cycle was begun (Fig. 32). 
 Pork affected with cysticerci is commonly known as 
 " measled " or " measly." 
 
 It occasionally happens that, instead of the development 
 of an intestinal worm after the swallowing of flesh containing 
 cysticerci celhilosce, the embryos pass into the muscles or vis- 
 cera of man. In this event he, equally with the hog, is play- 
 
236 
 
 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 :Man 
 
 Hog 
 
 ("Cyst. -CeU.) 
 Fig. 32. — Life cycle and intermediate hosts of taenia solium (after Bollinger). 
 
 ing the part of intermediate host. Under these circumstances 
 the larvae do not come to maturity, but remain in the muscles 
 
 Fig. 33. — Head of t;enia saginata. A, neck retracted; Ji, neck extended 
 (after Leuckart). 
 
 and organs, there to cause little or no inconvenience ; or, when 
 very numerous, to give ri.se to more or less grave symptoms, 
 according to their locality. 
 
DISEASES DUE TO ANIMAL PARASITES. 
 
 237 
 
 Occasionally this accident occurs in persons already sup- 
 porting a mature worm, the segments of which are passed 
 into the stomach during attacks of vomiting, there to liberate 
 embryos that penetrate into the muscles and viscera. 
 
 Taenia Saginata or Mediocanellata {Beef Tape-worm). — 
 This is the largest tape-worm encountered in man, being often 
 as much as 20 to 25 feet long and consisting of from 1000 to 
 1500 segments. The mature segments measure from 17 to 
 20 mm. (0.7-0.8 inch) in length, and from 5 to 7 mm. (0.2- 
 
 FlG. 34. — Cysticerci bovis. A, in muscle ; B, developmental form ; head 
 everted (Leuckart). 
 
 0.3 inch) in breadth. The head is relatively larger than 
 that of tcBuia solium; it is provided with four strong, 
 prominent suckers, but has no booklets (Fig. 33). Sexual 
 maturity begins with about the 600th proglottide. Each 
 mature segment is sexually complete — /. e., is provided with 
 both male and female generative organs. Development is 
 so rapid that it is said that as many as 10 fully mature pro- 
 glottides containing ova in large numbers may be ejected 
 daily. The ova have not the power of further develop- 
 ment when thrown off from the body, unless they are taken 
 into the stomach of the ox ; then the embryos pass into the 
 
238 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 voluntaiy muscles, to remain as bladder-worms or cysticerci 
 bozds (Fig. 34). Beef so infected is referred to as " measled." 
 It is upon the eating of such uncooked " measled beef " that 
 the larx-ai of tceiiia sagiiiata are introduced into the alimentary 
 tract of man, there to develop into the mature worm above 
 described (Fig. 35). The worm in beginning its growth at- 
 taches itself high up on the wall of the small Intestine. 
 
 Fig. 35. — Life cycle of taenia saginata (after Bollinger). 
 
 About two to three months intervene between the time of 
 ingestion of the larvae of this worm and the appearance of 
 proglottides in the dejecta. 
 
 Tcenia saginata is commoner in this country than is tcBiiia 
 solium, probably owing to the greater care that is given to 
 the cooking of pork. 
 
 Bothriocephalus latus, a large, long cestode found more 
 commonly in those whose diet is composed of fresh fish. It 
 is said to be common in the Baltic provinces and in parts of 
 Switzerland. In its larval form it is often encountered in the 
 abdominal cavity of the pike, its intermediate host, into which 
 the embryos are believed to have penetrated from without. 
 
 The adult worm is long, measuring from 8 to 9 meters ; is 
 thin at its edges, with a central longitudinal ridge ; and may 
 be composed of as many as 3000 to 3500 segments. Its head, 
 about 2 mm. (0.08 inch) long, is more or less conical ; is with- 
 out hooklets ; and is marked on either side by a longitudinally 
 grooved sucker (Fig. 36 B). The embiyo is ciliated, is pro- 
 
DISEASES DUE TO ANIMAL PARASITES. 239 
 
 Fig. 36. — A, Tasnia echinococcus , B, head of bothriocephalus latus (after 
 Leuckart). 
 
 vided with booklets, and is able to support itself in water for 
 more than a week. 
 
 Feeding experiments upon man, cats, and dogs with the 
 
 Man 
 
 Fish 
 (Young, 
 sexually 
 undifferentiated 
 Bothr.) 
 
 Unknown 
 Host 
 (Plerocercus) 
 
 Fig. 37. — Life cycle and intermediate hosts of bothriocephalus latus (after 
 Bollinger). 
 
 larvse of this parasite have resulted in the appearance of the 
 adult worm in the intestine (Fig. 37). 
 
 Taenia Echinococcus {Echinococcus Honiinis). — Occasion- 
 
240 
 
 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 ally man serves as the intermediate host in the life cycle of 
 this organism. The mature worm infests the dog, wolf, and 
 jackal. It is very small, measuring but about 5 mm. (0.2 
 inch) in length, and is composed of only 3 or 4 segments, the 
 last and largest of which alone exhibits all the characteristics 
 of sexual maturity. Its head is very small, is armed with a 
 double-row of from 30 to 50 heavy hooklets, and is provided 
 with four suckers (Fig. 36, A). 
 
 The narrow neck merges into the first, imperfectly devel- 
 oped, segment. The second segment is more markedly 
 differentiated, while the third, mature, segment is seen to 
 contain numerous eggs in which may be detected the six- 
 
 (Ta'n. Sol.) 
 
 Fig. 38. — Life cycle and intermediate hosts of taenia echinococcus (after Bollinger). 
 
 hooked embryos. For the further development of the 
 embryos after the escape of the eggs from the body it is 
 necessary that they enter the body of some other animal — • 
 the hog, the ox, or man. Here it penetrates to the viscera, 
 commonly the liver, and enters the larval or cysticercus 
 stage commonly known as hydatid or echinococcus cysts. 
 Unlike the other cysticerci mentioned, these have the power 
 while in this larval stage of increasing both in size and num- 
 ber. The scolices seen within the cysts, and they are often 
 numerous, are each the germ from which a mature worm 
 can develop when favorable circumstances present — i. c\, 
 when they gain access to the stomach of the dog (Fig. 38). 
 The commonest and practically the only source from which 
 echinococcus cysts are contracted in man is the dog. 
 
SECTION III. 
 
 PROPHYLAXIS IN GENERAL AGAINST INFEC- 
 TIOUS DISEASES, 
 
 INCLUDING VITAL, CHEMICAL, AND PHYSICAL PROCESSES, THE 
 MANAGEMENT OF CONTAGIOUS DISEASES, AND QUARANTINE. 
 
 VITAL PROCESSES. 
 
 Comprising' a consideration of Immunity, Natural and Acquired ; the 
 Practice of Vaccination and Protective Inoculation ; and the Evo- 
 lution of our Knowledge of the Antitoxic Condition. 
 
 The living animal body is provided by nature with the 
 means of combating more or less successfully the inroads of 
 infective agencies. Experiment has demonstrated that there 
 resides within the tissues and fluids of the healthy body the 
 property of destroying disease-producing micro-organisms in 
 large or smaller numbers. This function is especially notice- 
 able in the serum of the circulating blood, though it may 
 also be detected in other fluids and in the juices from the 
 normal organs. In vigorous health it is most manifest, while 
 the effects of malnutrition, fatigue, debauch, disease, and, in 
 short, all influences that materially disturb the equilibrium 
 of physiological function, are to diminish or destroy it totally. 
 On the other hand, experiment has also shown that by par- 
 ticular methods special weapons of defence for use against 
 specific invaders may be supplied to individuals from whom 
 they are normally absent, or be accentuated in their efficiency 
 in others in whom they are present to only a limited extent. 
 The practical procedures by which this is accomplished are 
 simple, though their modus operandi is as yet far from fully 
 understood. They comprise those operations that are con- 
 cerned in the artificial induction of vital resistance to particu- 
 
 16 241 
 
242 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 lar forms of disease, such as vaccination, protective inocula- 
 tion, and the other methods of affording immunity that are 
 herein to be mentioned. 
 
 In the famihar observation that a single non-fatal attack 
 of certain diseases often endows the individual with immunity 
 from subsequent inroads of the same malady, we have the 
 starting point for all that has been done in the important 
 field of preventive inoculation. 
 
 This is not by any means an observation of recent date. 
 Early in the eighteenth century it was the custom in certain 
 parts of the Orient to induce small-pox purposely by the 
 inoculation of healthy individuals with the matters from 
 small-pox patients. The idea was that if such an inoculation 
 was made from a mild case of the disease, only a mild attack 
 occurred in the person inoculated, and that with recovery he 
 was henceforth proof against the disease. 
 
 Prior to the introduction of vaccination by Jenner, and for 
 a short period afterward, the practice of inoculation was in 
 vogue in England, having been introduced into that country 
 by Lady Montague, who had become familiar with its em- 
 ployment in India. Though unquestionably lives were saved 
 by it, still, as Jenner himself testifies, much suffering was 
 entailed, many lives were sacrificed, and the disease was 
 often disseminated in a violent form as a result of the inocu- 
 lation. 
 
 The first scientific advocacy of a method which imitates 
 nature in affording immunity to an infectious disease, and 
 the benefits of which were not only practically certain, but 
 were obtained without jeopardy to life, was that of Jenner in 
 1798 in favor of vaccination against small-pox. Before the 
 time of Jenner's preventive vaccinations against this disease 
 it had been observed that after recovery from a harmless 
 attack of an affection known as cow-pox, the individuals so 
 affected were henceforth in most cases insusceptible to the 
 ravages of small-pox. 
 
 For a period of more than half a century after Jenner's 
 discoveries nothing was done to aj)i)lythe principles involved 
 in small-pox vaccination to the prevention of other diseases, 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 243 
 
 largely, perhaps, because nothing was known as to their 
 cause, and none of them possessed such peculiar relations 
 as had been noted between small-pox and cow-pox. 
 
 With the discoveries made about the middle of this century 
 that certain infectious diseases depended upon a tangible 
 cause, and the numerous additions to knowledge that rapidly 
 accumulated subsequently, the question of vital protection 
 again assumed a prominent place in the minds of scientific 
 workers. 
 
 The fact that single attacks of the diseases, acquired either 
 naturally or induced artificially, often protect the individual 
 against a subsequent attack, naturally suggested the query 
 respecting the cause of the phenomenon. Though this 
 problem is still under discussion and is still far from com- 
 pletely solved, yet the manifold investigations of recent years 
 upon the various phases of this many-sided subject have 
 been most fruitful. By exact experimental methods many 
 hitherto obscure points have been elucidated ; and though 
 much remains to be done, we can, nevertheless, speak with 
 a fair degree of confidence upon many of the important 
 features of the subject. 
 
 In the early studies in this field the ideas that were 
 advanced in explanation of immunity and susceptibility 
 belonged largely to the realm of the hypothetical. They 
 were without foundation in truth and when tried in the bal- 
 ance of experimental test were found to be sadly wanting. 
 From the time of Jenner's demonstration, in 1798, to the 
 effect that it was possible to protect human beings against 
 small-pox by vaccination with the lymph obtained from the 
 cow-pox vesicle — a phenomenon of the intimate nature of 
 which we know little more now than he did then — up to 
 1880, nothing was contributed to our knowledge of the sub- 
 ject. In 1880, in the course of his studies upon the cholera 
 of chickens, Pasteur^ showed, for the first time, that by arti- 
 ficial means it was possible so to modify the virulence of the 
 bacteria causing this disease that they would no longer pro- 
 duce fatal results, but, instead, only temporary local dis- 
 
 ^ Coftiptes rendus, Acad, des Sci., 1880, tome xci., p. 673. 
 
244 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 turbances, and that in these cases the chickens that had 
 recovered from such a modified attack were not now sus- 
 ceptible to the inroads of the highly virulent bacteria that 
 cause the fatal form of the infection. 
 
 In view of the fact that about the same date (1878-81) 
 Pasteur, Koch, Toussaint, and others had proved the rod- 
 shaped organisms discovered by Pollender (1855) and by 
 Davaine (1863) in the blood of animals dead of anthrax to 
 be the etiological factors concerned in this disease, it is not 
 surprising to find the observations of Pasteur utilized in a 
 scheme for the production of a vaccine against this much 
 dreaded disease, and as a result of numerous trials by differ- 
 ent experimenters, it was ultimately demonstrated that by 
 the employment of various agencies, thermal and chemical, 
 drying and prolonged cultivation under particular artificial 
 conditions, it was possible to do to the virulent anthrax 
 bacillus just what Pasteur had done to the bacillus of chicken 
 cholera — namely, to so attenuate its virulence that it no 
 longer killed susceptible animals, but caused instead only 
 temporary disturbances from which the animals recovered. 
 With recovery they were usually found to be no longer 
 susceptible to the more severe, commonly fatal, form of the 
 infection. We can justly say that it was in the course of 
 these studies on anthrax that the foundation stones were laid 
 for our knowledge of protective vaccination with attenuated 
 living virus. 
 
 Living vaccines capable of protecting animals more or less 
 completely against fatal infections have from time to time 
 been prepared by subjecting the virulent organisms that 
 cause the disease to a variety of detrimental agencies — 
 namely, by exposing them to the unfavorable conditions 
 that are active in the body of an insusceptible animal ; by 
 cultivating them under artificial circumstances in nutritive 
 media containing various hurtful chemical agents in such 
 strength as not to kill, but rather to interfere only with the 
 full development of their normal physiological functions ; 
 by cultivating them in normal nutritive media, but at a tem- 
 perature somewhat higher than that which is compatible with 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 245 
 
 vigorous growth ; by subjecting them for a short time to a 
 temperature that would prove fatal if its action were long 
 continued ; by drying ; by exposure to direct sunlight, to 
 electricity, to high pressure, and in short, by any of the 
 manifold deleterious influences that may be so regulated as 
 to retard development without actually destroying the organ- 
 ism. 
 
 Living vaccines, prepared by some one or other of the 
 foregoing procedures, have been employed experimentally 
 and in practice with varying degrees of success for the pur- 
 pose of protecting animals, and in two instances man, against 
 a number of infectious diseases, notably anthrax, sympto- 
 matic anthrax, swine erysipelas, pleuropneumonia, diphtheria, 
 glanders, pneumococcus infection, Asiatic cholera, and rabies 
 (the last two in man also). In no instance has their use been 
 as general or the results as satisfactory as in the case of 
 anthrax. 
 
 Of fundamental importance to our understanding of the 
 processes of immunity is the fact that the constitutional 
 symptoms and pathological lesions of disease are the results 
 of the toxic activities of metabolic products of the bacteria 
 concerned in the production of disease, and that immunity, as 
 well as disease, is established by these substances, not alone 
 when elaborated within the tissues of the animal to which the 
 bacteria have gained access, but also when they are produced 
 under artificial conditions of cultivation and purposely intro- 
 duced into susceptible animals. 
 
 An advance of great importance was made in our knowl- 
 edge of immunity through the application of this fact by 
 Salmon and Smith.^ They demonstrated that a certain sort 
 of immunity to particular forms of infection might be con- 
 ferred upon animals by injecting into them the filtered, germ- 
 free products of growth of certain bacteria to the pathogenic 
 influences of which the species of animal under treatment was 
 highly susceptible. 
 
 '^ Proc. Biolog. Soc, Washington, D. C. , 1886, vol. iii. ; Centralbl. filr 
 Bakt. zind Parasitenkunde, 1887, Bd. ii. ; Trans. IX. Internat. Med. Con- 
 gress, Washington 1887. 
 
246 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 This demonstration of the possibility of inducing immunity 
 through purely chemical, or biologico-chemical, means shed 
 an entirely new light on the subject. As a result of numer- 
 ous investigations suggested by this discovery, immunity is 
 to-day held by a number of those who have had most to do 
 with the elaboration of our knowledge of it as a purely 
 chemical phenomenon, a phenomenon that involves not the 
 micro-organisms themselves that are concerned in the pro- 
 duction of disease, but rather the agencies through which they 
 produce it — namely, their poisons. 
 
 It was subsequently demonstrated that if the poisonous 
 products of growth of certain pathogenic bacteria be intro- 
 duced into the body of a susceptible animal in non-fatal doses, 
 or in a condition of diminished toxicity, that the effect of such 
 treatment is exhibited by a more or less pronounced consti- 
 tutional reaction on the part of the animal. After recovery 
 from this temporary disturbance, the animal is often found to 
 be not only insusceptible to infection by the bacteria by which 
 the poison was manufactured, but the serum of its blood in 
 certain cases has undergone a demonstrable change : It has 
 acquired the property of neutralizing the fully virulent pois- 
 ons, though its property of destroying the bacteria them- 
 selves may not in all cases have been conspicuously altered. 
 In other words, in the process of acquiring immunity the 
 chemical composition of the blood is modified ; it is enriched 
 by the addition to it, through changes in the body, of a sub- 
 stance that is antidotal to the poisonous products of the patho- 
 genic bacteria against which the animal is immunized, with- 
 out its relation to the bacteria themselves having been in all 
 cases materially changed. 
 
 In this connection it is important to note that it is possible 
 by the repeated injections of non-fatal but gradually increas- 
 ing doses of toxins into susceptible animals to increase finally 
 the antitoxic value of the blood of that animal to a degree 
 far in excess of that ever seen to exist in immunity acquired 
 through an ordinary attack of disease, or the immunity that 
 is induced simply as a prevention against bacterial invasion. 
 It is in this way that antitoxic serums are obtained that are 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 247 
 
 of sufficient strength — that is, contain sufficient amount of 
 the antidote, to be of service in the treatment of disease 
 already in progress, a condition necessitating the neutraliza- 
 tion of large amounts of poison circulating in the body as 
 speedily as possible with the greatest amount of antidote 
 concentrated in the smallest bulk of the curative agent. 
 
 In the course of earlier investigations upon the subject, 
 Buchner ^ offered the suggestion that the immunity conferred 
 by a single attack of disease exists by reason of certain " re- 
 active changes'' that occur in the tissues during the disease, 
 and that with the establishment of this alteration the animal 
 acquires insusceptibility to further attacks of the same malady. 
 Though much has been done on the subject since this hy- 
 pothesis was advanced, we are to-day but little nearer the 
 actual solution of the problem than that which is embodied 
 in this view. 
 
 The opinion now generally held is that the tissues acquire, 
 during the constitutional reaction coincident with the primary 
 attack of the disease, the property of generating the anti- 
 dotal substance, though it is also believed, especially by Buch- 
 ner, that the antidotal or antitoxic body is in some cases the 
 poisonous products themselves of the bacteria so modified 
 through the reaction of the tissues that they now possess pro- 
 tective, neutralizing, or antitoxic peculiarities. On these points, 
 however, there are diverse opinions, and it is as yet impossi- 
 ble to speak with certainty. 
 
 The observation that the serum of the blood of a suscep- 
 tible animal could be rendered antidotal to certain bacterial 
 poisons by the gradual introduction into the animal of the 
 poisons until a condition of tolerance was reached, together 
 with the discovery that a certain group of highly pathogenic 
 bacteria produce their effects almost, if not entirely, through 
 poisons that they produce within the system, while they 
 themselves are localized to some particular point within or 
 upon the body, suggested a line of experiments having for 
 their object the practical application of these observations to 
 
 ^ " Eine neue Theorie iiber Erzielung von Immunitat gegen Infektions- 
 krankheiten," Muenchen, 1883. 
 
248 hygiEaXE of transmissible diseases. 
 
 the treatment of disease resulting from the activities of what 
 may be termed the truly toxic pathogenic bacteria. It was 
 in the course of these investigations that Behring and Kita- 
 sato ' made the important discovery that the serum of the 
 blood of animals rendered tolerant to certain bacterial toxins 
 not only afforded protection to these animals against the 
 poisonous effects of these substances through antidotal prop- 
 erties, but that by the transference of serum from this immu- 
 nized animal to another susceptible animal, that immunity 
 was at once conferred upon the animal into which such serum 
 had been injected. The original observation was made in the 
 course of studies upon tetanus. 
 
 It was not long, however, before the principles upon 
 which this observation rested were applied to the study of 
 other forms of toxic infection, with the result of placing in 
 our hands, through the labors of Behring and his associates, 
 an agent whose favorable influence upon the course of the 
 diphtheritic infection is so pronounced as to justify the 
 opinion that with the introduction of the antitoxic serum 
 to the treatment of diphtheria, an epoch was marked in 
 the history of medicine. 
 
 By some the method of inducing and transferring immu- 
 nity, as elaborated by Behring and his colleagues, is considered 
 as only the induction of a condition of tolerance to chemical 
 poisons — i. e., the rendering of an animal poison-proof (Gift- 
 fest), and not as a protection to bacterial infection. There is 
 evidence, however, to indicate that this view is erroneous, 
 and that the method is applicable in certain cases of true 
 infection that are not characterized by marked toxic fea- 
 tures.^ 
 
 In the present state of our knowledge it is impossible to 
 say to what extent acquired immunity in human beings is 
 due to the presence of antitoxic substances in the circulating 
 fluids, or to indicate in how far the observations that have 
 been made upon tetanus and diphtheria are applicable to 
 
 * Deutsche mcd. Wach., 1890, Bd. xvi., S. 1113. 
 
 ^ Consult Kitt : Centi-albl. fur Bakl. und Parasitenkundc, 1893, S. 869 ; 
 Lorenz : Ibid., 1893, S. 357, and 1894, S. 278. 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 249 
 
 other infections ; certainly, in so far as the truly toxic infec- 
 tions are concerned, one is constrained to feel sanguine as to 
 the ultimate outcome of the further application of the prin- 
 ciples on which the antitoxic method of treatment is based. 
 As a precautionary measure, however, it may not be amiss to 
 emphasize the impropriety of generalizing from these single 
 instances. We must bear in mind that the conclusions 
 reached with regard to tetanus in animals, and diphtheria in 
 man, are the results of observations having an incontestable 
 experimental basis, without which any pseudoscientific struct- 
 ure that we may rear through analogical reasoning will, 
 sooner or later, totter and fall without a moment's warning. 
 The wider application of these principles to the treatment of 
 disease is only to succeed through the establishment of a firm 
 basis of experimental proof for each separate and distinct 
 affection. From this it is clear to those who are familiar with 
 laboratory methods that there are many obstacles to be over- 
 come, some of them in our present position, almost insur- 
 mountable. The impossibility of faithfully reproducing in 
 animals that we use for experiment some of the most impor- 
 tant diseases to which human beings are liable, may serve as 
 an example of one of the gravest of these difficulties. 
 
 From what has preceded, we observe that we must dis- 
 tinguish between three principal methods of inducing immu- 
 nity — namely, by the activities of living bacteria in the tis- 
 sues — i. e., by living vaccines ; through the introduction into 
 the body of the germ-free, poisonous products of bacteria ; 
 and through the introduction into susceptible animals of the 
 serum of the blood (and other secretions) from another ani- 
 mal already immunized. 
 
 By either the first or second of these procedures the con- 
 dition of immunity is established only after the lapse of the 
 time necessary for the elaboration of the immunizing sub- 
 stances within the tissues ; whereas, by the last method these 
 substances that have already been prepared in the immunized 
 animal from which the serum is obtained are transferred di- 
 rectly, and the animal receiving them is at once protected ; 
 
250 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 as Ehrlich ^ conceives it, one simply transfers the protecting 
 agent from one animal to another. 
 
 There is a further distinction as regards the results of these 
 methods of procedure. The immunity that is induced through 
 vaccination with attenuated living virus, or conferred by the 
 gradual introduction of toxins to the point of tolerance, simu- 
 lates more closely in the degree of its permanence the immu- 
 nity usually conferred by a non-fatal attack of infection con- 
 tracted in the ordinary walks of life than does that produced 
 by the injection of the serum of immunized animals. 
 
 Ehrlich^ proposes to designate the more or less permanent 
 immunity frequently conferred by an attack of an infectious 
 disea:se as " active immunity," while for the immunity that is 
 established through the direct transference of the immunizing 
 agent from the blood of one animal to the tissues of another 
 he employs the name " passive immunity." This designation 
 is not acceptable to all writers on the subject, the objection 
 being that there is not as yet sufficient proof that the induc- 
 tion of " passive immunity "is as simple a matter as Ehrlich 
 conceives it to be. There is some evidence in support of the 
 idea that the real immunizing agent may not be contained in 
 the immunizing serum, but that this serum is only instru- 
 mental in inducing the peculiar tissue-reaction that results in 
 the formation of the actual protecting body. 
 
 Another point in connection with this subject, on which 
 there has been considerable controversy, is that concerning 
 the specificity of the relation between the immunity-inducing 
 toxins and the antitoxic substances elaborated in the body as 
 a protection against them. By the majority of investigators 
 there is believed to be a specific antagonism between the 
 poisons produced by a given infectious micro-organism and 
 the protective agent that is present in the body of the animal 
 artificially immunized against this particular micro-organism. 
 Objections have been raised to accepting this as a law, on the 
 grounds that the serum of artificially immunized animals is 
 
 ' Ehrlich : Deutsche vied. IVoch., 1898, Nos. 32-44 ; Zeil. f. Ilyg. und 
 
 Infcktionskrankhciten, 1S92, Bd. xii., S. 183; and Hiibener : Ibid., 
 
 1894, Bd. xviii., S. 51. * Loc. cit. 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 25 I 
 
 sometimes seen to possess protective properties, to a limited 
 extent, against forms of infection or intoxication other than 
 that against which the animal has been protected. In this 
 connection, it must be remembered that the nonnal serum of 
 man, of horses, and occasionally of other animals, has also at 
 times been observed to possess similar ''general" antitoxic 
 peculiarities. It may be that the observations on which are 
 based the objections to the idea of a specific relation between 
 particular toxins and their antitoxins can be explained through 
 this normally present, universal, so to speak, antidote. 
 
 In a number of experiments, antitoxic properties of the 
 serum against specific bacterial poisons have been induced 
 through the induction of tolerance to the poisons of bacteria 
 of a different species. This condition appears, however, to be 
 little more than an accentuation of the normally present pro- 
 tective agent already referred to. It has never been possible 
 to bring about in this manner as high or as permanent a de- 
 gree of immunity against a particular disease as that which 
 can be obtained by the use of the specific micro-organism 
 causing the disease, or the products of its growth. 
 
 Of fundamental importance in their bearing upon this sub- 
 ject are the remarkable observations of Pfeiffer.^ He showed 
 that it was easily possible to confer upon guinea-pigs a con- 
 dition of immunity to Asiatic cholera by the repeated injec- 
 tions into them of sterilized cultures of the organism causing 
 the disease. If upon the establishment of immunity he now 
 injected into the peritoneal cavity of these animals an amount 
 of the living culture that would otherwise certainly prove 
 fatal, not only had this no effect, but within a few minutes, 
 almost instantly, there was an -actual disintegration of the 
 organisms injected that could readily be followed with the 
 microscope. He demonstrated, further, that this relation be- 
 tween the immune animal and the organisms against which it 
 was protected was a specific one, and that no such disintegra- 
 tion occurred when other bacteria were injected. If, with the 
 cholera spirillum other bacteria were injected, only the chol- 
 
 ^ Zeit. f. Hyg. unci Infektionskrankheiten, Bd. xviii., S. I ; Ibid., Bd. xx., 
 S. iq8. 
 
252 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 era spirillum was thus broken up. He showed, in addition, 
 that while the serum of the blood of the immune animal was 
 capable of conferring immunity from Asiatic cholera upon other 
 animals not immune, it had no disintegrating effect upon the 
 cholera spirillum when in contact with it in the test-tube, but 
 if he injected into the peritoneal cavity of a non-immunized 
 guinea-pig the fatal dose of hving cholera spirillum, and fol- 
 lowed this immediately by an intraperitoneal injection of the 
 serum from an immune animal, at once the disintegration of 
 the bacteria within the peritoneal cavity was to be detected. 
 
 It will be seen that these investigations are of importance, 
 not alone as regards the question of specificity, but also as 
 regards the nature and origin of the protecting body, for we 
 have here a serum from an immune animal capable of con- 
 ferring immunity — capable, when injected into the susceptible 
 animal, of endowing it with the peculiar germicidal function 
 noted in the immune animal from which the serum originated, 
 but still, totally incapable of this remarkable bactericidal activ- 
 ity when tested outside the animal body. Manifestly, the real 
 protective agent is generated by the tissues as a result of the 
 specific irritation of a something contained in the serum. 
 
 Applying this principle in part to certain other infectious 
 diseases, it has been shown that the serum from cases of 
 typhoid fever when brought in contact with pure cultures of 
 the typhoid bacillus outside the body has the property of 
 arresting its motility and causing the individual cells to 
 arrange themselves in clumps, a condition never seen in 
 normal cultures of this organism and a condition that is 
 seen only when typhoid bacilli and typhoid serum are in 
 contact. It docs not occur when other organisms are used, 
 nor, so far as experience goes, does it result from the use of 
 other serums with this organism. 
 
 We mu.st remember, however, that our knowledge on this 
 subject does not as yet admit of the laying down of hard 
 and fast laws, and it is not unlikely that much of what we 
 consider as sound to-day may to-morrow prove to be untrust- 
 worthy. We are in many respects hardly more than on the 
 threshold of this many-sided subject. 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 253 
 
 Equal in interest and importance to any of the other prob- 
 lems relating to the question of acquired immunity, is that 
 concerning its transmissibility from parent to offspring. Can 
 the condition of acquired immunity from particular infections 
 and intoxications be inherited ? 
 
 While there have arisen from time to time examples that 
 serve to indicate the possibility of this question being an- 
 swered in the affirmative, we are indebted to Ehrlich ^ for the 
 experimental demonstration of the accuracy of these indica- 
 tions. In the course of a series of studies upon the vegetable 
 toxalbumins, abrin, ricin, and robin, especially as regards 
 their intoxicating effects upon animals, and the methods of 
 inducing immunity from them, he demonstrated the possibility 
 of easily inducing in white mice, normally markedly suscep- 
 tible to these poisons, a condition of resistance that enabled 
 them to Avithstand large multiples of the otherwise fatal dose. 
 He likewise conclusively demonstrated that females on whom 
 such immunity had been conferred transmitted, through the 
 milk, to their nursing young, an antitoxic substance that 
 induced in them a condition of body through which they, 
 too, were enabled to resist the otherwise fatal dose of the 
 particular poison against which the mother was immunized. 
 This transmission of immunity appears to be entirely a ma- 
 ternal function, the father, in Ehrlich's experiments, playing no 
 part in the process. 
 
 From the preceding considerations of the subject we see 
 that a condition of immunity from certain forms of infection 
 may be more or less easily acquired, and that, when once 
 acquired, it may be in some cases conferred upon the young 
 during the nursing period, through the milk of the mother. 
 But there is no positive proof that such conferrence occurs 
 during intra-uterine life. 
 
 In the light of these established facts, one might be tempted 
 to consider the natural immunity possessed by certain in- 
 dividuals and species from particular forms of disease as, 
 after all, an acquired trait — acquired not as a result of the 
 purposeful inoculation of progenitors with modified virus or 
 
 ^ Loc. cit. 
 
254 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 attenuated toxins, but rather acquired through the processes 
 of survival and hereditary transmission. For instance, one 
 might argue that when a given number of individuals become 
 affected with the same form of infection, those that survive 
 are manifestly not only less susceptible to its inroads than 
 were those that succumbed, but, as we have seen, the decree 
 of this insusceptibility is further increased by the attack of 
 the disease through which they have safely passed. These 
 survivors, it might be claimed, transmit to their offspring not 
 only certain mental and structural characteristics, but physio- 
 logical peculiarities as well, among which may be a condition 
 of insusceptibility to this particular form of infection that has 
 been accentuated at the nursing period through the protect- 
 ing influences of the milk of an immune mother. Still, in 
 support of this view one might continue : the constant pres- 
 ence in a community of a certain form of disease is ultimately 
 accompanied by a diminution of its virulence and a lower 
 degree of fatality from it than is seen to follow its first or only 
 occasional appearance, and that continuous exposure, there- 
 fore, of large numbers of individuals to particular diseases 
 may result, through the natural phenomena of survival and 
 inheritance, in developing a race endowed with nahiral iiisus- 
 ccptibility to this malady. 
 
 Plausible and attractive as this view may appear on super- 
 ficial examination, there are objections to its adoption. 
 
 In the strict sense of the word, and in the light of present 
 knowledge, we must regard natural immunity as a trait that 
 has been transmitted, and is further transmissible, through 
 generations by parents in whom it is blastogenic. It is con- 
 genital, therefore, and inherent to the integral protoplasm of 
 the individual or species endowed with it. There is no evi- 
 dence of its having been acquired through any of the chan- 
 nels that apply to the acquisition of immunity. Its trans- 
 mission, like other physiological peculiarities, is probably as 
 much under the paternal as the maternal influence, and is 
 lasting ; whereas, the transmission of acquired immunity is a 
 function only of the mother and, so far as we know, is of but 
 temporary du ration. 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 255 
 
 There can be no doubt that the constant exposure of a 
 race of individuals to a disease ultimately results in a diminu- 
 tion of susceptibility of many of the individuals to this dis- 
 ease. It appears to be more logical to consider this condi- 
 tion of " acclimatization," as it is popularly called, from two 
 standpoints — namely, with regard to the individual, and with 
 regard to the race. Where it concerns an individual it is 
 either natural, in the sense of the word " natural " as here 
 used — i. c, an idioplasmic characteristic, or is acqinred, as a 
 result of an attack of the disease through which the indi- 
 vidual has safely passed ; where it concerns a race it appears 
 to be much more likely that it has evolved as a result of the 
 survival and multiplication of those individuals of the race 
 who were by nature — /. c, congenital — either completely or 
 partly insusceptible, their susceptible fellows having gradually 
 been exterminated. 
 
 It may be safely said that probably no human race is, as a 
 whole, immune from any disease of man. Nevertheless, in 
 every race there may be encountered individuals who are 
 more or less immune to this or that disease ; and with regard 
 to the relation of certain races to particular diseases the pro- 
 portion of such individuals may be conspicuously high. 
 
 Still further in favor of the idioplasmic origin of this 
 peculiarity of natural imniiinity, and in opposition to its 
 acquisition by exposure to disease, is the fact that even 
 among these races which, through constant exposure to 
 particular diseases, have become " acclimated," the newly 
 born do not from birth partake, as a rule, of the peculiarity, 
 and usually become insusceptible only after having had the 
 disease. A striking illustration of this is offered by the 
 Creole populations in yellow-fever districts. While not 
 totally immuned from the disease, the Creoles are, as a race, 
 much less susceptible than their white brothers, and yet, on 
 the authority of Guiteras, " the foci of endemicity of yellow 
 fever are essentially maintained by the Creole infant popula- 
 tion." Manifestly, the relative insusceptibility of the Creole 
 to this disease is not a race characteristic, but is rather one 
 that the individual acquires for himself only with recovery 
 
256 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 from the disease. The increase of tissue-resistance acquired 
 in this way cannot be regarded as natural immunity in the 
 sense in which the term is now generally understood. 
 
 To admit that the condition of natural immunity repre- 
 sents, after all, the inheritance of an induced peculiarity, is to 
 admit in general the possibility of the hereditary transmission 
 of acquired traits, " an assumption that has often been made, 
 but never yet proved." ^ 
 
 Natural immunity must as yet be considered as a vital 
 property, inherent to the idioplasm, the intimate nature and 
 workings of which cannot be explained. It distinguishes the 
 individual endowed with it only by its protective influences 
 during exposure to particular forms of disease. It is not 
 explainable through any demonstrable excess of protective 
 characteristics of the body-fluids or tissues, contrary to what 
 may usually be done in the case of artificially immunized 
 animals, for, as stated above, the fluids of the body of the 
 naturally immune animal may be neither more nor less 
 germicidal or antitoxic than are similar fluids from animals 
 that are naturally susceptible. 
 
 Manifestly, the prevention and treatment of disease along 
 the lines suggested by the investigations here cited in many 
 respects closely simulate some of the methods of nature. It 
 is from this standpoint that we believe the further elaboration 
 and wider application of the principles involved in the proc- 
 esses of preventive inoculation and serum therapeutics are 
 destined to be of inestimable service in the advancement of 
 the preventive and curative medicine of the future. 
 
 Already as a result of these labors, animals have been 
 rendered more or less insusceptible to a number of different 
 infections and intoxications — for instance, to chicken cholera, 
 anthrax, erysipelas, symptomatic anthrax, malignant edema, 
 hog cholera, typhoid fever, hemorrhagic septicemia, vibrionic 
 septicemia, Asiatic cholera, diphtheria, tetanus, pneumococcus 
 infection, pyocyaneus infection, proteus infection, infection or 
 
 ' Weismann, "Essays on Heredity and Kindred Biological Problems;" 
 "Essay on Retrogressive Development in Nature," vol. ii., p. 14. Edited by 
 Poulton and Shipley, Oxford, Clarendon Press, 1892. 
 
PROPHYLAXIS AGAINST INFECTIOUS DISEASES. 2$"/ 
 
 intoxication by bacillus coll coininiinis, and infections by 
 pyogenic cocci. 
 
 Not only has the possibility of conferring immunity to these 
 infections been demonstrated, but in the case of certain of 
 them the serum of the blood of the immunized animals has 
 been found to possess properties that can be utilized in the 
 treatment of these infections or intoxications after they are 
 already in progress in other animals. Thus, for example, the 
 treatment of diphtheria by the antitoxin method comes under 
 this head. In the case of erysipelas, the experiments of 
 Marmorek ^ and others indicate similar possibilities. Marmorek 
 found in the blood of rabbits immunized from infection by 
 the streptococcus of erysipelas, a substance that he states 
 possesses curative powers over the disease when it is already 
 in progress in non-immunized animals. Pfeiffer and Kolle ^ 
 have detected in the blood of animals rendered tolerant to 
 the typhoid toxin a substance that is germicidal to the typhoid 
 bacillus, and Beumer and Peiper^ find a non-germicidal, but 
 rather an antitoxic substance in the blood of animals artifici- 
 ally immunized from the typhoid poison. Beumer and Peiper 
 state that this serum possesses not only immunizing powers, 
 but that the poisonous effects of the typhoid toxins can be 
 neutralized by the subsequent injection of the antitoxic serum. 
 They believe, therefore, that the serum possesses curative 
 virtues. Yersin, Borel, and Calmette,* in their studies upon 
 bubonic plague, obtained from the blood of animals rendered 
 immune from this infection an actively antitoxic serum that 
 they hope to utilize ultimately in the treatment of the disease. 
 The studies on vaccinia lead to the belief that there exists in 
 the blood of the vaccinated animal a substance possessing 
 certain antagonistic relations to the active principle of vac- 
 cine lymph,^ whatever that may be. In this case, as with 
 
 ^ La semaine vied., 1895, ^'^o- '7 ! Annales de P Inst. Pasteur, 1895, tome 
 ix. ; consult also Roger : Ibid. 
 
 ^ Deutsche med. JVock., 1894, No. 48. 
 
 ' Zeit. f.- klin. Med., Bd. xxviii., Hefte 3 and 4. 
 
 * Annales de V Inst. Pasteur, 1895, No. 7. 
 
 ^ For literature on this subject consult Sternberg and Reed : Trans. Assoc, 
 of Avier. Phys., 1895, vol. x., p. 57. 
 17 
 
258 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 scarlatina, both experiments and results are unsatisfactory, 
 because of the important unknown factors that come into 
 play. From recent investigations it seems probable that the 
 treatment of tetanus by means of antitoxic serum, as is 
 shown to be possible in animals, will, before a very great 
 while, be successfully extended to the disease in men. The 
 treatment of Asiatic cholera by the antitoxin method is ap- 
 parently destined to be an outcome of the very near future, 
 and finally, the experiments bearing upon the treatment of 
 tuberculosis by means of antitoxic substances is predicted by 
 Behring to be soon successfully demonstrated. Behring and 
 Knorr ^ already claim to have detected in the blood of ani- 
 mals rendered tolerant to the poisonous influences of tuber- 
 culin (the toxin produced by bacillus tuber adosis), a body, 
 antituberculin, that possesses the property of robbing tuber- 
 culin of its poisonous peculiarities. 
 
 When we contemplate this array of practical results and 
 bear in mind that they are the outgrowth of experiments 
 made with a definite purpose, each step of which was directed 
 toward a particular object, and that through these experi- 
 ments susceptible animals — and, in a few instances, man — 
 have been, and may at will be, rendered more or less immune 
 from a number of diseases of bacterial origin, there is justifica- 
 tion for the statement " that the probfems relating to immu- 
 nity and infection have been, in part at least, removed from 
 the realm of pure hypothesis and placed in a position favor- 
 able to exact experimental solution " (Welch). 
 
 ' Behring : Address delivered before the 67th meeting of Naturalists, at 
 Lubeck — Deutsche 7ned. IVocA., 1895, No. 38. 
 
ChEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 259 
 
 CHEMICAL AND PHYSICAL PROPHYLACTIC 
 MEASURES. 
 
 We have already learned that there is thrown off from the 
 body in the course of transmissible diseases substances which, 
 if not destroyed, possess the power, under favorable circum- 
 stances, of disseminating these maladies. In some instances 
 such infective agents are contained in the secretions from the 
 mouth, throat, and nose, as in diphtheria and whooping 
 cough ; in others they are present in the matters spat up 
 from the lungs, as in pulmonary tuberculosis, influenza, and 
 pneumonia ; again, they are present in the vomited matters 
 and evacuations from the bowels, as in cholera, typhoid fever, 
 and tropical dysentery ; while in still other cases they are 
 discharged through lesions of the skin consequent upon sub- 
 cutaneous suppurations, or from the surface of the skin itself, 
 as during the desquamation period of the acute exanthemata. 
 
 We have also learned that the majority and the most im- 
 portant of the factors directly concerned in the causation of 
 specific communicable diseases are living micro-organisms — 
 bacteria — and that as they are expelled from the infected in- 
 dividual they are often associated with other bacterial species 
 that are concerned in disease-production — /. e., with the inno- 
 cent varieties usually present in the mouth, the intestines, and 
 the skin. 
 
 In many instances these infective micro-organisms find con- 
 ditions outside the body that are not at once detrimental to 
 their vitality and pathogenic activity ; indeed, under particu- 
 lar enviroment they are capable of increase and multiplica- 
 tion and of becoming the source from which the disease may 
 be disseminated through large groups of susceptible individu- 
 als. With the view of preventing such accidents disinfection 
 and isolation are practised. 
 
 Disinfection. — Strictly speaking, the term disinfection 
 signifies the destruction of infective agents, but by the 
 methods of disinfection commonly in use, there is no dis- 
 crimination made between the various species of bacteria, 
 and all living micro-organisms, innocent as well as infective, 
 
26o JIYGIENE OF TRANSMISSIBLE DISEASES. 
 
 fall victim to the germicidal activity of approved disin- 
 fectants. 
 
 The terms disinfectant and germicide have, therefore, be- 
 come synonymous by usage, and in this sense a disinfected 
 mass is one in which all living micro-organisms have been 
 killed. 
 
 It seems proper at this place to define the precise meaning 
 of several terms that are used in connection with the various 
 methods that are employed against the development of bac- 
 teria and for the suppression of their malodorous metabolic 
 products. Such definitions become necessary because of the 
 frequent misunderstanding of the meanings of the terms and 
 of the principles involved, and because of the confusion that 
 arises from their indiscriminate and inaccurate use. Briefly 
 then, a disinfectant or germicide (the terms as stated are, by 
 usage, synonymous) may be defined as a substance that kills 
 bacteria and their spores ; an antiseptic is a substance that is 
 antagonistic to the growth of bacteria without of necessity 
 killing them ; while a deodorizer may be either a disinfectant 
 or an antiseptic, or neither, but simply a substance having the 
 power of destroying or masking odor, without regard to either 
 destruction of the micro-organisms that cause it or the arrest 
 of their development. 
 
 In the practice of disinfection there should be maintained 
 a tolerably fixed relation between the amount of a given dis- 
 infectant used and the mass of matter to be disinfected — /. e., 
 the number of bacteria to be killed. If this ratio be not 
 observed there is either an excess of disinfectant or there is 
 a scarcity ; in the latter event disinfection is incomplete. 
 
 The majority of disinfectants have the property of prevent- 
 ing the development of bacteria, even when employed in 
 solutions very much weaker than would be necessary for 
 disinfection ; that is, in these smaller quantities they exhibit 
 antiseptic functions. Many antiseptics have no disinfectant 
 or germicidal properties whatever. This is true of many of 
 the weaker vegetable acids, of a number of aromatic bodies, 
 of sugar, and of sodium chloride. 
 
 When added to un decomposed matters both disinfectants 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 26 1 
 
 and antiseptics prevent decomposition and putrefaction, and, 
 consequently, the evolution of bad odors, but when decom- 
 position is well advanced there are few, if any, of the trust- 
 worthy disinfectants that have the property of completely 
 destroying bad odors. Many compounds are used for this 
 purpose, but, as a rule, their employment amounts to little 
 more than the substitution of one odor for another. 
 
 There are a great many substances that are possessed of 
 germicidal properties, though the list of those worthy of 
 confidence, and hence of those in common use, is compara- 
 tively small. 
 
 For convenience of description the modes of disinfection 
 here described will be classified as chemical and physical. 
 
 Chemical Disinfection. — By chemical disinfection we un- 
 derstand the destruction of the vitality of living micro-organ- 
 isms, through the- use of chemical compounds. In its prac- 
 tical application the disinfectant is mixed with or applied to 
 the mass or article to be disinfected, in such proportions and 
 after such a manner as experiment has dictated to be most 
 favorable to the accomplishment of the desired result. 
 
 In many cases it is not possible to explain the inodiis oper- 
 andi of disinfection, any more than to say that the micro- 
 organisms are poisoned by the disinfectant, though in partic- 
 ular instances this is accomplished by a union between the 
 disinfectant and the protoplasm of the bacteria ; in others 
 there seems to be a coagulation of the albuminoid constit- 
 uents of the bacteria, while in others disinfection succeeds 
 through the disintegrating influence that the disinfectant has 
 upon the bacteria. 
 
 The essentials of a useful and trustworthy chemical disin- 
 fectant are : 
 
 1. It shall be a germicide — /. c, it shall possess the property 
 of destroying bacteria and their spores. 
 
 2. It should be so constituted that its germicidal properties 
 are not destroyed by the extraneous matters in which the 
 infective micro-organisms that are to be killed are located. 
 
 3. With ordinary care it should not be dangerous (directly 
 poisonous) to those who are to use it. 
 
262 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 4. It should, if possible, be without disagreeable odor ; it 
 should be cheap in price, easy to manipulate, and for particular 
 purposes should not cause permanent stains or be destructive 
 to the skin, to fabrics, or to other articles on which it is to be 
 employed. 
 
 The entire list of chemical preparations that possess more 
 or less germicidal properties is too long to introduce in a 
 book of this size. It will suffice to mention only those that 
 may be regarded as of the greatest general usefulness. 
 
 Sulphur Dioxide ; SulpJiurojis-acid Gas, SOj. — Until within 
 a very short time there was probably no gaseous disinfectant 
 that was more commonly used, or which enjoyed a greater 
 degree of confidence than did the fumes arising from the 
 combustion of sulphur. Its principal employment has been 
 for the fumigation of apartments, wards of hospitals, ship- 
 cabins and -holds, etc. 
 
 Modern investigations have, however, shown that the use- 
 fulness of this gas for the purpose of disinfection is compara- 
 tively limited. In the dry state it possesses little penetration, 
 does not destroy spores, and is uncertain in its action even 
 upon non-spore-forming organisms. The amount of it that 
 is at all reliable should not be less than 4 per cent, by volume 
 of the air-capacity of the room, and this should be maintained 
 for from twelve to twenty-four hours — a condition very dif- 
 ficult to meet when we remember the practical impossibility 
 of so sealing all cracks, pores, and openings of a room as to 
 prevent diffusion. 
 
 Its efficiency is markedly increased when the objects to be 
 disinfected are moist, a condition that may in part be met by 
 spraying with water or by generating steam at the same time 
 that the gas is being evolved. Upon moist objects its ger- 
 micidal powers are comparatively marked for those micro- 
 organisms that do not form spores, but even here the materials 
 to be disinfected must be freely exposed to its action. 
 
 In the practical use of this gas as a disinfectant the follow- 
 ing precautions are to be observed, otherwise its employment 
 is useless : 
 
 All visible cracks, crevices, and openings of the room to be 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 263 
 
 disinfected should be carefully closed with strips of adhesive 
 paper or with putty. To obviate accidents from fire, while 
 the sulphur is burning, a tub half filled with water should be 
 placed in the center of the room ; two bricks are to be stood 
 on end in it, and on the top of these is to rest the pan in which 
 the sulphur is to be burned. Into the pan is to be placed 
 sulphur in the proportion of 3 pounds to each lOOO cu. ft. of 
 air-space in the room. The objects in the room are then to 
 be moistened either by spraying with a hand-atomizer con- 
 taining water, or else by condensed steam generated from 
 boiling water. Finally, a little alcohol is poured over the 
 sulphur in the pan, lighted, and the door of the room closed 
 and kept closed for twenty-four hours. At the end of this 
 time doors and windows are thrown open and the room thor- 
 oughly aired. The danger from fire may be eliminated by 
 using compressed sulphur dioxide instead of the gas obtained 
 by burning sulphur. The gas may be obtained from the 
 dealers in a liquefied state (liquefied by pressure) in metal 
 cylinders provided with valves for its liberation. These 
 cylinders may either be placed in the room and the gas 
 slowly liberated, or they may be placed in an adjoining 
 hallway or room and the required amount of gas conveyed 
 into the infected room by a tube passed through the key- 
 hole of the door. After the room has been kept closed 
 for the necessary time, the usual cleansing operations may 
 be begun. All objects, such as pillows, mattresses, bundles, 
 clothing in closets, chests, etc., should be disinfected by 
 steam. 
 
 Chlorine and bromine possess marked disinfecting prop- 
 erties. Like sulphurous-acid gas, however, they exhibit 
 their highest germicidal peculiarities only upon moistened 
 objects. They are not in general practical use, for the reason 
 that they are more or less destructive to fabrics, tissues, etc., 
 but more especially because of their very irritating and some- 
 times dangerous action upon the respiratory apparatus of 
 those who are using them. In the gaseous condition they 
 are not to be recommended for general use. 
 
 Formaldehyde, Formie Aldehyde, Formalin, etc. — Formal- 
 
264 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 dehyde, the vapor resulting from the slow (incomplete) com- 
 bustion of methyl alcohol under access of air, is the aldehyde 
 of formic acid ; or, in other words, it is an alcohol of the 
 marsh-gas (methane) series from which hydrogen has been 
 extracted by oxidation. The position of formaldehyde in the 
 series of products that result from the oxidation of marsh 
 gas is as follows : 
 
 Marsh Gas, Methane. Methyl Alcohol. Formaldehyde. Formic Acid. 
 CH,. CHp. CH.p. Cn.f).,. 
 
 When formaldehyde gas is dissolved in water to about 
 the point of saturation, we have the proprietary solution 
 known commercially as formalin. Formalin represents 
 a solution of formaldehyde gas in water of the strength 
 of from 35 to 40 per cent, by weight. For practical purposes 
 of disinfection this body is employed both in its pure gaseous 
 state as formaldehyde, and in its watery solution as formalin. 
 
 Fig. 39. — Lamp for jjent-rating fornialdchydc from methyl alcohol. 
 
 The active gas as used for purposes of disinfection is obtained 
 in several ways — viz., by the slow combustion of methyl alco- 
 hol in lamps especially constructed for the purpose (sec Fig. 
 39); by liberating it from its watery solution under the influ- 
 ence of high temperature, in especially constructed autoclaves 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 265 
 
 and generators (Figs. 40-42) ; and by decomposing its solid 
 • polymerized form in open vessels through the action of heat 
 (Fig. 41). The various forms of apparatus on the market for 
 the purpose are fully described in the circulars issued by 
 their several makers. 
 
 Since the discovery that formaldehyde vapor possesses 
 very marked germicidal properties it has been subjected to 
 
 Fig. 40. — Autoclaves for generating formaldehyde (i) from formalin and (2) 
 from formochloral : A, chamber for reception of the fluid ; both chambers are 
 hermetically sealed when apparatus is in operation ; B, lamp for supplying heat ; 
 C, tube for conducting gas from generator into the room to be disinfected. 
 
 most careful study in this connection, by a number of com- 
 petent investigators ; and though the results have been in 
 some respects discordant they agree in certain essential points 
 — viz., that formaldehyde obtained by either of the several 
 processes in common use is a gaseous disinfectant of high 
 
266 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 order for the surfaces of rooms and for contained objects 
 
 Fig. 41. — Apparatus for generating formaldehyde from tablets of polymerized 
 formaldehyde : i, small form ; 2, for larger quantities ; A in each figure indicates 
 the cup in which the tablets are placed. 
 
 when the latter are freely exposed to its action ; that it quickly 
 
 Fk;. 42. — Modified Novy-Waite formaldehyde generator : A, retort for con- 
 taining formalin ; B, lamp for supplying heat ; C, tube for conducting gas from 
 retort into room to be disinfected. 
 
 destroys not only the Icss-rcsistant, non-sporc-formin^ patho- 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 26/ 
 
 genie bacteria, but the more highly-resistant spore-formers 
 and their spores as well ; that to accomplish this end there 
 must be a definite relation between the gas used and the space 
 to be disinfected ; and that the space shall be so closed that 
 this relation may be maintained for a definite length of time. 
 
 Its powers of penetration cannot be relied upon, and when 
 used in rooms, hospital wards, etc., all articles, such as mat- 
 tresses, pillows, clothing in chests, closets, trunks, etc., had 
 better be subsequently subjected to disinfection by streaming 
 steam. 
 
 The methods thus far tested for the generation of this gas 
 that have shown themselves to be least trustworthy are those 
 in which methyl alcohol is slowly burned in lamps. As a 
 rule, the lamps have been too small and their continuous 
 combustion too uncertain ; moreover, even with the best of 
 them the actual amount of formaldehyde produced has been 
 but a comparatively small proportion of the amount that is 
 theoretically possible. It is not improbable that these defects 
 may be overcome in some of the devices subsequently to be 
 introduced. 
 
 The methods that have found most favor are those in which 
 the nascent gas is liberated from its watery solution and from 
 its solid polymerized products. In the former case this is 
 accomplished through the employment of autoclaves in which 
 the solution, either formalin or formochloral (a mixture of 
 formalin, practically free of methyl alcohol, and calcium chlo- 
 ride) is placed, and is brought to a high temperature under 
 pressure. When it is sufficiently heated, the gas is liberated 
 by the opening of a valve and is conveyed through a tube 
 into the apartment to be disinfected ; or in other forms of 
 apparatus a temperature sufficiently high to dissociate the gas 
 is obtained by passing its watery solution through a highly- 
 heated metal coil, which in turn is connected with a tube for 
 the delivery of the gas into the apartment for disinfection. 
 
 By the latter process — /. c, the decomposition of its soHd 
 form — tablets of compressed, polymerized formaldehyde are 
 simply heated in a properly constructed vessel over a free 
 flame. By the high temperature to which they are thus sub- 
 
268 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 jected the polymerized body is decomposed into its constitu- 
 ent molecules, and formaldehyde is set free as such. 
 
 Since no two apartments present identically the same con- 
 ditions, it is manifestly impossible to lay down fixed laws 
 for the use of formaldehyde as a practical disinfectant for 
 dwellings, and doubtless it is this circumstance that is in 
 part, at least, answerable for the discrepancy in the results 
 of its use by different investigators. It may be said, 
 however, that for general practice the following proced- 
 ures are necessary : Because of the diffusibility of the gas 
 at ordinary dwelling-room temperature all cracks and crev- 
 ices through which it could escape from the room are to be 
 closed, either through the use of adhesive paper or by plug- 
 ging with rags or raw cotton. If either the lamp, generating 
 the gas from methyl alcohol, or the apparatus that liberates 
 it from solid tablets of polymerized formaldehyde are to be 
 used, they are placed in the center of the room and ignited ; 
 if the former, at least i quart of methyl alcohol is to be 
 burned for every lOOO cu. ft. of room to be disinfected; if 
 the latter, from 50 to 75 tablets are to be decomposed for the 
 same cubic air-space. The room is to be kept closed for ten 
 to twelve hours, after which it should be thoroughly aired. 
 By either of these procedures it is necessary to leave a lighted 
 lamp unattended in a closed room for a comparatively long 
 time, so that it is advisable to take precautions against fire ; 
 such, for instance, as standing the apparatus upon a large 
 sheet of tin or in a large tin pan. 
 
 If either of the forms of apparatus used to generate the gas 
 from its watery solution be employed, this is set in operation 
 in the hallway or in an adjoining room, and the gas is passed 
 from the generator into the room by means of a tube passed 
 through the key-hole, the room in this case, as in the other, 
 having been made as nearly air-tight as possible. In this 
 process a safe rule is to evaporate the gas from one pound 
 of formalin or formochloral for every 1000 to 1200 cu. ft. of 
 space to be disinfected, and to keep the room closed for five 
 or six hours after the gas has been generated. At the end 
 of this time the room should be thoroughly aired. 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 269 
 
 In our personal experience we have obtained the most 
 satisfactory results through the use of formalin to which 10 
 per cent, of glycerin has been added, as recommended by 
 Schlossmann ; and through the employment of a generator ' 
 after the plan of that devised by Novy and Waite — viz., a 
 simple copper retort into which the formalin-glycerin mixture 
 is placed and from which the gas is disengaged by heat and 
 conveyed through a tube into the room to be disinfected 
 (Fig. 42). In these tests we found that 80 per cent, of all 
 exposed infected objects in a room could be disinfected when 
 500 c.c. of the formalin-glycerin mixture per 1000 cu. ft. of 
 air-space was completely evaporated and the room kept 
 closed for three or four hours. 
 
 After disinfection the disagreeable and irritating odor of 
 formaldehyde may be removed by sprinkling the room with 
 ammonia water, or by placing in the room several open pans 
 containing ammonia. 
 
 The gas is not poisonous, though very irritating. It has 
 little or no destructive action upon objects in the room and, 
 as stated, is highly to be recommended as a superficial disin- 
 fectant, though its penetrating action is uncertain. 
 
 In addition to its disinfecting properties formaldehyde is a 
 marked deodorizer, combining to form odorless compounds 
 with such bodies as sulphuretted hydrogen, ammonia, mer- 
 captan, and other offensive products of decomposition. For 
 the disinfection and deodorization of closets, vaults, safes, etc., 
 in which such malodorous and, at times, infected objects, as 
 bank-notes, public documents, and papers are stored, it has 
 proved to be of very great service. 
 
 Carbolic acid is employed as a disinfectant, in the form of 
 watery solutions of from 3 to 5 per cent, strength by weight. 
 
 It is unreliable for the disinfection of spores, but occupies 
 a high place in the list of disinfectants to be used against the 
 non-spore -forming infective bacteria. In 5 per cent, solution 
 it is a useful disinfectant for sputum, vomited matters, and 
 fecal evacuations ; and in 2 per cent, solution may be safely 
 
 ^ The apparatus mentioned is made by Messrs. Chas. Lentz & Sons, Phila. ; 
 a similar apparatus is also made by Messrs. Parke, Davis, & Co. 
 
2/0 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 employed as a wash for wooden surfaces, furniture, floors, 
 etc. 
 
 In its crj^'stalline form and in its stronger solutions it is 
 possessed of poisonous properties, and sliould always be so 
 labelled, to avoid accidents. It is also in these forms, espe- 
 cially the crystalHne, an active escharotic, and should not 
 therefore be handled with the fingers. 
 
 In order to obtain its germicidal action its solution must 
 be thoroughly mixed with the matters to be disinfected, so 
 that it comes in intimate contact with them. 
 
 It is valueless as an air-disinfectant, and neither spraying 
 the room nor the placing about of open vessels containing 
 carbolic acid has any appreciable effect beyond the genera- 
 tion of its odor throughout the premises. 
 
 A I per cent, solution of the pure acid, when allowed to 
 act under the most favorable circumstances (/. e., in labo- 
 ratory experiments), is destructive to the pathogenic cocci, 
 the bacillus of typhoid fever, the spirillum of Asiatic cholera, 
 and numerous other non-spore -forming pathogenic bacteria. 
 In practice, however, stronger solutions should be employed, 
 rarely weaker than 2 per cent., for the reason that the con- 
 ditions under which it is to act are always much less favor- 
 able than are those under which the laboratory tests are made. 
 
 A convenient method for using carbolic-acid solutions is 
 to dissolve about six ounces of the pure carbolic acid in a 
 gallon of hot water, which is approximately a 5 per cent, 
 solution — that is, a saturated solution. From this dilutions 
 may be made, and it is advisable not to use dilutions weaker 
 than from 2 to 2^ per cent. 
 
 Carbol-sidphuric acid represents a mixture of equal parts 
 of crude carbolic acid and concentrated sulphuric acid. The 
 mixture is made by slowly adding to the carbolic acid, which 
 is contained in a vessel that stands in water for the purpose 
 of checking the development of heat, an equal volume of 
 concentrated sulphuric acid. 
 
 From this mixture solutions of from 2 to 3 per cent, can 
 be made in water. This is not an actual solution, but is 
 rather an emulsion. 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 2/ 1 
 
 Sulphuric acid not only renders the insoluble crude car- 
 bolic acid more soluble, but increases its germicidal proper- 
 ties as well. The preparation is used only for the disinfec- 
 tion of sinks, cesspools, urinals, gutters, privy-vaults, etc. It 
 should not be allowed to remain for any considerable length 
 of time in contact with metal, brass fixtures, etc. Its disin- 
 fectant value is about equal to that of the pure acid, but the 
 cost of the preparation is only one-third to one-half that of 
 the pure acid. 
 
 Carbol-soap solution is prepared as follows : dissolve 3 
 parts of soft soap in 100 parts of warm water. When the 
 solution is complete add, slowly stirring as it is added, 5 
 parts of the commercial (not the pure) carbolic acid. This 
 forms a permanent solution having about the same disin- 
 fectant value as a solution of the pure acid, and is useful for 
 the disinfection of bed- and body-clothing before they are 
 sent to the laundry. The articles should be thoroughly 
 immersed in it and allowed to remain for two or three hours. 
 It may also be used for general scrubbing purposes. Since 
 it has some bleaching properties, it is best to restrict its use 
 to the disinfection of white goods. 
 
 The cresols — meta-, para-, and ortho-cresol — obtained by 
 distillation from coal-tar and from crude carbolic acid, have 
 been shown to possess high germicidal properties. Their 
 activity is increased by the addition of an equal bulk of sul- 
 phuric acid. A 4 per cent, solution of these acid mixtures 
 was found by Frankel to destroy spores of bacillus anthracis 
 as follows : Meta-cresol, in eight hours ; para-cresol, in ten 
 hours ; and ortho-cresol, in twenty hours. For coarse dis- 
 infection Frankel recommends a 5 per cent, solution of a mix- 
 ture of equal parts of the raw cresols and cone, sulphuric 
 acid. This is destructive to spores in five to six hours, while 
 a 3 per cent, solution is germicidal for non-spore-forming bac- 
 teria, in a few minutes. It may be used for the same pur- 
 poses as carbolic acid. 
 
 Tricresol is a refined mixture of the three cresols men- 
 tioned above, in about the following proportions : Meta- 
 cresol, 40 per cent. ; para-cresol, 25 per cent; ortho-cresol, 
 
272 HYGIENE OF TRAKSMISSFBLE DISEASES. 
 
 33 per cent. It is soluble in water in from 2.2 to 2.5 per 
 cent. It possesses about three times the germicidal value of 
 carbolic acid, and is, therefore, particularly useful for disin- 
 fection in connection with surgical and obstetrical work, 
 especially since its activity is but little diminished by the 
 presence of albuminous matters. 
 
 Like carbolic acid, the cresols are poisonous. 
 
 Solutions of tricresol, in water, of from 0.5 to i.oper cent, 
 strength, are germicidal for sporeless bacteria in a few min- 
 utes and in a few seconds respectively. 
 
 Creolin is a coal-tar product possessing relatively high dis- 
 infectant properties. It is a thick fluid resembling, in a way, 
 crude carbolic acid. It is nearly insoluble in water, so that 
 dilutions of it are really emulsions, and require, therefore, to 
 be thoroughly agitated each time they are used. The ger- 
 micidal activities are interfered with by the presence of albu- 
 minous matters in the mass to be disinfected. In practice it 
 is used as a 2 to 5 per cent, emulsion in water, and should be 
 thoroughly mixed with the matters to be disinfected. It is 
 especially useful for the disinfection of urinals, drains, gut- 
 ters, kennels, stables, etc. 
 
 Bichloride of Mercwy. — Notwithstanding the conspicuous 
 germicidal properties of this salt, there are objections to its 
 use in general practice. It is an active poison ; it has a cor- 
 roding action upon all metals with which it comes in contact ; 
 its germicidal activities are very much diminished by the 
 presence of albuminous matters in the mass to be disinfected, 
 and its solutions are unstable unless protected from light and 
 air. 
 
 Since it is an active poison whose solution is colorless, it is 
 always wise to add to the solution some inert coloring mat- 
 ter — fuchsin, for instance — that may serve to distinguish it 
 and thus aid in avoiding accidents. 
 
 It is employed for general disinfecting purposes in solutions 
 of from I : lOOO to 1 : 5000 strength. In these proportions 
 it is useful for the scrubbing of woodwork, floors, pavements, 
 gutters, etc., and for wiping down walls that are not injured 
 by it. It is also of service as a preparatory disinfectant for 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 273 
 
 infected clothing before they are sent to the laundry, though 
 the stains of blood and feces are rendered almost indelible by 
 long soaking in this solution. The clothing should be im- 
 mersed in the solution for two hours. 
 
 If sublimate solutions are to be employed for the disinfec- 
 tion of feces, sputum, and other matters containing albumin, 
 certain precautions must be taken — viz., the mass must be 
 mixed in either an earthenware or wooden vessel, as corro- 
 sive sublimate both destroys and becomes itself destroyed 
 when in contact with metal. To prevent its precipitation by 
 albumin, and hence loss of germicidal powers, the solution 
 should always contain a certain amount of sodium chloride. 
 
 A useful formula for this purpose is to add to a i : 2000 
 corrosive-sublimate solution common salt in the proportion 
 of from 0.5 to I per cent. — in other words, to a gallon of the 
 sublimate solution four teaspoonfuls of salt. The solution 
 must be made in a glass or wooden vessel. 
 
 Silver nitrate is, according to all experiments, as active a 
 germicide as corrosive sublimate, and has the advantage, ac- 
 cording to Behring, over the mercury salt of being much more 
 trustworthy for use with substances containing albumin. 
 
 In I : 1200 solution it destroys anthrax spores in seventy 
 hours, while the organisms of cholera, typhoid fever, glan- 
 ders, and diphtheria are killed in two hours by solutions of 
 I : 2500. 
 
 Chloride of Lime. — There are few more useful disinfectants 
 than a good preparation of chloride of lime, and by good 
 preparation is meant one in which the proportion of available 
 chlorine does not fall below 25 to 30 per cent. 
 
 A solution in water of such a preparation in the strength 
 of 0.5 to I per cent, by weight has been shown to disinfect 
 typhoid and cholera stools completely in ten minutes, while 
 a I per cent, solution destroys bacilhis antJiracis, in laboratory 
 experiments, in two hours. In order for it to manifest its 
 germicidal properties it is necessary that the solution should 
 be brought in intimate contact with the objects to be disin- 
 fected. The common practice of placing about open dishes 
 containing small amounts of chloride of lime has little more 
 
 18 
 
274 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 effect than to create a disagreeable odor. The preparation is 
 cheap, is not poisonous, and is efficient ; but it must be re- 
 membered that it easily undergoes decomposition, and should 
 be made up fresh when it is needed for use, and should be 
 made from freshly-prepared salts. Its efficiency depends upon 
 the amount of chlorine contained in it in the form of hypo- 
 chlorites. 
 
 The disagreeable odor of chloride may be eliminated by 
 hanging about cloths soaked in strong soda solution after dis- 
 infection is complete. 
 
 Labarraque's solution, the official liqiior sodce clilorinatcgy 
 depends for its disinfecting properties, like chloride of lime, 
 upon the chlorine present as hypochlorite. It should contain 
 at least 3 per cent, of available chlorine. 
 
 For use it is diluted with five times its bulk of water, 
 which gives a solution of 0.5 per cent, of chlorine. It may 
 be used for the same purposes as the chloride-of-lime solution. 
 It is a more attractive preparation, but also more expensive, 
 than the Hme salt. 
 
 Milk of Lime. — This preparation is little more than fluid 
 " whitewash." It is made by slaking i quart of finely 
 divided, freshly burned lime in i quart of water, after which 
 3 quarts of water are added and the mass thoroughly stirred. 
 
 The active mixture consists of lime dissolved and sus- 
 pended in water. It should always be freshly prepared and 
 thoroughly stirred, before being applied to the affected mass. 
 
 It is principally used for the disinfection of feces, privies, 
 gutters, etc., and when so employed should be mixed with 
 the mass to be disinfected until the whole reacts, distinctly 
 alkaline, as determined by the use of litmus paper. For the 
 disinfection of cholera and typhoid stools a good rule is to 
 mix thoroughly with them an equal volume of milk of lime 
 and allow it to stand covered for one hour, after which it may 
 be diluted with hot water and poured slowly into the water- 
 closet, the flush of the closet being allowed to run at the same 
 time. It should not be thrown into the water-closet without 
 dilution, for the reason that the thick mass, especially the lime, 
 may accumulate and obstruct the pipes. 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 2"/$ 
 
 Used as " whitewash," it is an important disinfectant for 
 the walls of hospitals, barracks, cellars, and other apartments 
 where contagious disease or infective or putrefactive matters 
 may have been. 
 
 Soda Solutions. — Experiment has shown that a solution of 
 common washing soda, especially when heated, possesses very 
 marked germicidal activities. In addition to this it is one of 
 the most useful cleansing agents. For scrubbing and general 
 cleaning purposes the solution recommended is i part of 
 soda in 25 parts of boiling water — i. e., 4 per cent, by weight. 
 Applied hot, this not only removes dirt, but disinfects as well. 
 
 For use as a disinfectant for bed- and body-clothes, instru- 
 ments, eating-utensils, etc., it is employed in a 2 per cent, 
 solution at boiling temperature. An ordinary wash-boiler is 
 a convenient apparatus in which to carry out the process. 
 
 Caustic Soda: Caustic Potassa. — Solutions of either of 
 these salts in the strength of 0.5 to i per cent, are destruc- 
 tive in two hours to such pathogenic bacteria as bac. dipli- 
 therics, bac. typhi abdominalis, and the glanders bacillus. 
 Spore-bearing materials require stronger solutions, the spores 
 of anthrax being killed by a 4 per cent, solution in forty-five 
 minutes. 
 
 Caustic ammonia has no effect upon spores, but is germicidal 
 in two hours for practically all non-spore-bearing pathogenic 
 bacteria in solutions of from 0.3 to 0.6 per cent, of the official 
 solution in water. 
 
 Acids. — Many infective micro-organisms are extremely sen- 
 sitive to unusual variations in the reaction of the medium in 
 which they are located. The majority of acids, especially the 
 mineral acids, serve, therefore, a useful purpose when used as 
 disinfectants, though their employment is limited because of 
 their effect upon metal objects, with which they may come 
 in contact. 
 
 Hydrochloric acid in the strength of 5 : 1000 solution 
 readily destroys non-spore-forming pathogenic bacteria in 
 two hours, though in even four times this strength — /. e., 
 2 per cent. — it requires as long as ten days to kill the spores 
 of anthrax. 
 
2/6 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 SidpJmric acid, in from 2 to 15 per cent, solution, re- 
 quires from fifty-three hours to eight days to destroy spores ; 
 while in 5 : lOOO it is fatal to practically all non-spore -forming 
 bacteria having pathogenic properties, in two hours. 
 
 Pcnna)iga]iatc of potash has little or no disinfecting powers 
 when used in its ordinary watery solution. It is employed in 
 this condition more as a deodorizer. The strength of the 
 solution is about 4 ounces of the salt to the gallon of water. 
 When used in its strong alkaline or acid solution a low degree 
 of disinfective activity may be exhibited, but it is never to be 
 relied upon. 
 
 Stdpliate of iron is used as a disinfectant and deodorizer for 
 privy-vaults, cesspools, fecal matters, etc. 
 
 For this purpose 4 pounds of the salt dissolved in a gallon 
 and a half of water are to be used for every cubic yard of the 
 vault to be treated. 
 
 As a germicide it is not so trustworthy as are the other 
 preparations recommended for this purpose, and though fre- 
 quently used its benefits are more as an antiseptic and deodor- 
 izer than as an actual germicide. 
 
 Garden Earth. — Well-dried and sifted garden loam has 
 marked deodorizing powers over fecal matters. 
 
 If mixed with a very small quantity of pulverized lime, so 
 that the latter is present in from 4 to 6 per cent, by weight, 
 it is said to have a certain degree of disinfective action, and 
 this mixture is recommended by some authors, but unfortu- 
 nately the lime, by its germicidal action upon the bacteria in 
 the earth, may defeat the very object for which the earth is 
 used — /. f., the destruction, by nitrificatioji, of the organic 
 constituents of the feces, and by this the prevention of putre- 
 factive odors. 
 
 Garden loam cannot be regarded as a trustworthy disin- 
 fectant, and if the evacuations require disinfection, some other 
 safer process should be employed. It is only a deodorizer 
 and disintegrator. 
 
 For deodorization enough dried earth must be used to 
 cover the feces completely. Moisture interferes with the 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 2// 
 
 process of deodorization in direct proportion to the amount 
 present. 
 
 Chalk, gravel, or sand is not suitable for this purpose. 
 
 The figures given above for the strengths of solutions of 
 the various disinfectants recommended are those obtained by 
 laboratory tests under the most favorable conditions. 
 
 They teach that in the practical use of disinfectants it does 
 not answer to sprinkle about the premises or over the mass 
 to be disinfected a little, more or less, of the disinfectant to 
 be used, but that a definite quantity must be employed for a 
 minimum length of time before the best results can be ex- 
 pected. Thus, for instance, it has been said above that a 
 3 per cent, solution of carbolic acid, a o. i per cent, solution 
 of corrosive subUmate, and a i per cent, solution of chloride 
 of lime are useful disinfectants, but this does not mean that 
 the addition of such substances at random to the infected 
 matters always results in successful disinfection. It means 
 rather that the agents must be in intimate contact with the 
 materials to be disinfected, in proportions not less than those 
 expressed by the figures given. Thus, if it were desirable to 
 disinfect a mass of feces of about a liter capacity with chlo- 
 ride of lime in the strength of i per cent, solution it would 
 be necessary to mix thoroughly with it either lo grams of the 
 salt in substance, or, what would be better, a liter of a watery 
 solution of the salt in the strength of 2 per cent., so that in 
 the resulting mixture chloride of lime would be present in 
 not less than half this amount — i. e., the desired i per cent. 
 So it is with the other disinfectants mentioned. 
 
 Special Chemical Disinfection. — Privy Vaults, Evac= 
 uations, etc. — In the first place, privy vaults, or any other 
 contrivance for the accumulation of excrementitious matters, 
 should not be tolerated in thickly-populated communities. 
 Unfortunately, however, they are occasionally encountered and 
 therefore require care. By the frequent removal of the con- 
 tents of cesspools and the continuous employment of disin- 
 fecting materials we not only prevent the offensive odors con- 
 sequent upon putrefaction, but check the development or 
 
2/8 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 destroy outright the germs of disease that may gain access 
 to them. It is often recommended to use deodorants in this 
 connection, under ordinary circumstances, and to employ dis- 
 infectants only when the privy is known to contain infective 
 matters, such as cholera or typhoid stools. Since it is just as 
 simple and as cheap and always safer to employ disinfectants 
 as a routine practice, we prefer to recommend this procedure. 
 By their frequent use the development of all germ life is 
 checked, and therefore putrefaction with its bad odors is also 
 prevented. 
 
 The cheapest and probably the most practical disinfectant 
 for the contents of privy vaults is milk of lime, made after 
 directions given above. This should be mixed with the mass 
 to be disinfected in the proportion of about 2 per cent, of the 
 contents of the vault, or it should be added and be thoroughly 
 mixed until the entire mass reacts distinctly alkaHne to litmus 
 paper. Another rule is to add to the cesspool about 2 liters 
 (quarts) of milk of Hme daily for each individual using the 
 privy. By beginning with an empty and clean privy vault 
 and adding the lime mixture daily, not only is the odor pre- 
 vented, but the mass is continuously disinfected. 
 
 Sulphate of iron is highly recommended for the suppres- 
 sion of offensive odors from such receptacles. 
 
 The liberal sprinkling of chloride of lime in powder over 
 the mass in a cesspool, not only serves to disinfect but to 
 check putrefactive odors as well. 
 
 It is always advisable, however, where cesspools must be 
 used, to disinfect thoroughly all infected matters, such as ty- 
 phoid, dysenteric, and cholera stools, before they are emptied 
 into the vault, as disinfection is much more certainly and 
 easily accomplished with such small volumes of matter than 
 it would be after the entire mass in the vault had become 
 infected. 
 
 Water-closets, Urinals, and Sinks. — The continuous 
 treatment of water-closets, urinals, and sinks is called for 
 more to suppress bad odors than to destroy infective matters. 
 As a routine practice cleanliness, in this respect, is above all 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 279 
 
 other modes of procedure, and in private houses is usually 
 all that is required. 
 
 In public places, however, it is to be recommended that 
 the ordinary modes of mechanical cleaning, often only imper- 
 fectly performed, should be supplemented by steps to pre- 
 vent putrefaction and consequent bad odors. For this pur- 
 pose the 3 per cent, carbolic-acid, or the i per cent, chloride- 
 of-lime solution will be found useful. The closet-pans and 
 the urinals should be thoroughly brushed once a day with 
 the disinfectant. 
 
 The odor that is almost constant in and about public 
 urinals is, as a rule, due to neglect of the ordinary laws 
 of cleanliness. It arises from the decomposition of urine 
 that has not been passed into the proper receptacle. It may 
 be obviated by constant scrubbing, by the free sprinkling of 
 the premises with either of the solutions named, or may be 
 masked by placing lumps of camphor or of carbolized soap 
 in the urinals. 
 
 Where infective matters have gained access to water-closets 
 or sinks, these receptacles should be thoroughly scrubbed 
 with 5 per cent, carbolic-acid, or 2 per cent, chloride-of-lime 
 solution. Sufficient of the solution should be passed into 
 them to fill the trap completely, and there should always be 
 a residue of from a pint to a quart of the solution in the body 
 of the fixture. This should be repeated after each time the 
 closet is used for infected discharges. As stated above, how- 
 ever, infected evacuations should always be disinfected before 
 they are thrown into the closets. 
 
 Stables and Cellars. — When suspected of being infected 
 the walls, floors, ceilings, and all objects upon which sus- 
 picion rests should be thoroughly saturated, without other- 
 wise disturbing them, with either the 5 per cent, carbol-sul- 
 phuric acid solution, or 5 per cent, creolin solution, or 2 per 
 cent, chloride-of-lime solution, and kept wet with it over 
 night. The premises should then be thoroughly cleaned 
 with a boiling 4 per cent, solution of common washing soda. 
 
 In the case of cellars and the less elaborate stables, the 
 walls and ceilings should be whitewashed. 
 
28o HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 The harness worn by diseased animals, especially bits, 
 should be first disinfected with one of the solutions named 
 above, then thoroughly washed with hot soda solution, and 
 finally rinsed with warm water and dried. 
 
 The disinfection should always precede the cleansing, other- 
 wise infective matters in a living state may be disseminated 
 from the infected focus during the ordinary steps of the 
 cleansing process. 
 
 Disinfection of Wells and Cisterns. — It is not necessary 
 to emphasize the fact that where possible all suspicious drink- 
 ing waters should be abandoned, and that water for domestic 
 uses should be beyond suspicion of pollution ; but circum- 
 stances may arise through which a well, the only readily 
 available source of supply for an isolated family, settlement, 
 or company of soldiers, may become temporarily infected and 
 seriously inconvenience the users of the water, unless some 
 safe remedy is at hand. To meet the requirements of such 
 cases efforts have been made to determine in how far it is 
 possible to disinfect wells, with the result of demonstrating 
 that this is a practicable procedure, providing the pollution 
 has been but to a slight extent and is not continuous. Of 
 course, a well fed by polluted ground water, or a well into 
 which infective matters are continuously and unavoidably 
 passing from the surface, cannot be rendered safe by any 
 process of disinfection, and should be abandoned. 
 
 The methods that are recommended for the disinfection of 
 wells that have been only temporarily polluted, as by the 
 accidental deposition into them of infective matters from 
 above, or by the washing into them of such matters as a 
 result of excessive rains, are as follows : 
 
 If the water be raised to the surface by a pump, remove 
 the latter and pour down the pipe a mixture of equal parts of 
 raw carbolic acid and sulphuric acid until it is present in the 
 proportion of about 5 per cent, of the contents of the well. 
 The water should be thoroughly stirred so as to complete 
 the mixing of the acids with it, and the walls of the well 
 should be scrubbed with brooms dipped in the water. The 
 inside of the delivering pipe should be thoroughly cleaned by 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 28 I 
 
 mechanically scrubbing it with a long-handled brush wet with 
 the acid solution. After standing for twenty-four hours the 
 contents should be pumped out, the slime from the bottom 
 thoroughly removed, the well allowed to refill ; this water is 
 again pumped out, and this must be repeated until all traces 
 of the acid have disappeared. Another plan consists in the 
 use of lime. Here the delivery pipe, if a pump is used, is to 
 be scrubbed on its inside with strong carbolic-acid solution ; 
 there is then to be thrown into the well about 40 to 50 pounds 
 of freshly burned lime ; after the Hme dissolves, the walls of 
 the well are to be thoroughly scrubbed with its solution. The 
 contents are then pumped out, or otherwise removed ; the 
 slime from the bottom is baled out completely, and lime in the 
 same proportion is again added and allowed to slake and 
 dissolve as the well refills. The whole is, after twenty-four 
 hours, to be thoroughly stirred and again removed. The 
 well is again allowed to refill and is re-emptied, and this 
 is continued until the pumped water is practically free from 
 lime. 
 
 With tube wells only the inside of the tube needs atten- 
 tion. This should be thoroughly brushed with the carbol- 
 sulphuric-acid mixture, and water pumped through it until 
 the acid (phenol) reaction disappears. 
 
 Cisterns should be treated as wells. 
 
 These procedures are not ideal from a sanitary standpoint, 
 but circumstances may arise when they would be far better 
 than no precautions at all. 
 
 For drinking purposes alone all water that is of necessity 
 derived from suspicious sources should be boiled before 
 being used, and no process of chemical disinfection can in 
 any way compare with this method from the standpoint of 
 safety and practical utility. 
 
 Disinfection of the Hands. — Of the numerous methods 
 recommended only two will be given as thoroughly trust- 
 worthy — viz., that of Fiirbringer and that of Welch, as 
 developed at the Johns Hopkins Hospital. 
 
 Furbringer'' s method : 
 
 I. Remove all dirt from under and around the nails. 
 
282 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 2. Brush nails and skin of hands thoroughly with soap 
 and hot water. 
 
 3. Immerse in alcohol, 95 per cent, for not less than a 
 minute, and before this evaporates. 
 
 4. Plunge the hands in i : 500 corrosive-sublimate or 3 
 per cent, carbolic-acid solution, and thoroughly wash them 
 for at least a minute, after which the hands may be rinsed in 
 warm water and dried. 
 
 WclcJCs method : 
 
 1. The hands and nails are to be thoroughly cleansed with 
 hot water and soap. The water is to be as hot as can be 
 borne, and the brush used is to have been sterilized by 
 steam. This preliminary brushing to occupy from three to 
 five minutes. 
 
 2. The hands are then rinsed in clean warm water. 
 
 3. They are then immersed for one or two minutes in a 
 warm, saturated solution of permanganate of potash. While 
 in this solution they are rubbed thoroughly with a sterilized 
 swab of absorbent cotton. 
 
 4. They are then placed in a warm, saturated solution of 
 oxalic acid and kept there until completely decolorized. 
 
 5. They are then thoroughly washed in clear sterilized 
 water or salt solution. 
 
 6. Finally, they are immersed for two minutes in i : 500 
 corrosive-sublimate solution, rinsed in water, and dried. 
 
 Disinfection through Physical Processes. — Under 
 this head are embraced methods for the destruction of infec- 
 tive agents by the use of such physical influences as are 
 antagonistic to their vitality, as for example, heat, cold, elec- 
 tricity, light, and pressure. 
 
 Disinfection by Heat. — Heat in one form or another is 
 the most trustworthy germicide that we possess. It is em- 
 ployed according to circumstances as ordinary fire, free 
 flames, and as dry heat, the articles to be disinfected being 
 protected in a properly-constructed oven; as boiling water; 
 as streaming or live .steam ; and as steam under pressure. 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 283 
 
 Fire. — The free flames are resorted to only when it is 
 desirable to consume valueless articles completely which 
 would hardly pay for the trouble of disinfecting by the 
 usual processes, such, for example, as old straw mattresses, 
 worn-out clothing, useless furniture or bed-clothing, etc. 
 
 Dry Heat. — The process of disinfection by dry heat in 
 ovens constructed for the purpose was formerly much more 
 in vogue than it is at present. It has been practically aban- 
 doned for the reasons that dry heat has but little penetrating 
 power as compared with steam ; that it requires a longer 
 time for disinfection than is necessary for steam ; and that 
 the high temperature and prolonged exposure are together 
 detrimental to many articles that are disinfected by this 
 method. 
 
 Complete disinfection by dry heat cannot always be antici- 
 pated, even when a temperature of 130° to 140° C. has been 
 maintained for as long as three hours, conditions that are 
 manifestly destructive to many articles that might be sub- 
 jected to the process. 
 
 It is only to be recommended when no other means are at 
 hand. 
 
 Boiling. — Boiling water destroys all pathogenic bacteria 
 and their spores in five minutes. Its disinfecting action is 
 further increased by the addition of i to 2 per cent, of soda. 
 This is an especially handy method for domestic disinfection 
 of clothing, eating-utensils, etc. A wash-boiler is simply 
 filled with water or soda solution, which is brought to the 
 boiling point, and the articles are immersed in it and boiled 
 for five or ten minutes. For the disinfection of surgical 
 instruments the boiling soda solution has found very general 
 favor. 
 
 Streaming or Live Steam. — For disinfection by this method 
 special forms of apparatus are manufactured. They are sold 
 under the name of " steam sterilizers " and " steam disin- 
 fectors." The simplest construction for domestic purposes 
 is the ordinary potato steamer that is used in the kitchen, 
 the articles to be disinfected being placed in the upper com- 
 partment, the water in the lower, the cover placed in position 
 
284 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 and the apparatus placed over the fire and the water kept 
 boiling from ten to fifteen minutes. Several refinements of 
 this apparatus are now to be had, the one that has found 
 most favor being that sold as " Arnold's Steam Sterilizer." 
 For more extensive use more elaborate and varying designs 
 of these steamers are employed. They are usually of such 
 size and strength as to accommodate a mattress, or a bundle 
 
 Fig. 43. — Portable steam disinfector, equipped with chamber of sufficient 
 size to accommodate bed-clothing, mattresses, etc., and a boiler for generating 
 
 steam. 
 
 of clothing, etc. (in Fig. 43 is depicted a very serviceable 
 portable form of steam disinfector). The principle involved 
 is the same in all of them, the point aimed at being to keep 
 the articles fully exposed to the penetrating action of live 
 steam for the time necessary to disinfect them. 
 
 For complete disinfection with streaming steam twenty-five 
 minutes is necessary with loosely placed articles, while an 
 hour is not too long when the articles are closely packed in 
 the apparatus. In both instances the time of disinfection is 
 to be reckoned from the time at which steam begins to stream 
 freely from the apparatus. 
 
 Steam Jtiidcr Pressure. — Disinfection by this process is ac- 
 complished by subjecting tlie infected articles to steam that is 
 confined in a closed chamber. As it is under additional 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 285 
 
 pressure because of its confinement, it is at a correspondingly 
 higher temperature. By this method the disinfection of lar- 
 ger, bulkier objects, such as bales of rags, packages of mer- 
 chandise, bundles of clothing, etc., is more certainly and 
 quickly accomplished, because of the higher temperature and 
 excess of pressure under which the steam is kept. For dis- 
 infection, on the large scale, as at hospitals, lazarettos, quar- 
 antine stations, etc., this form of apparatus has almost taken 
 the place of that in which streaming or live steam is used 
 
 Fig. 44. — The " Kny-Sprague " disinfecting chamber, equipped with cars for 
 loading the chamber with articles to be disinfected. 
 
 (Fig. 44). In the simplest form of this apparatus the articles 
 are placed in the chamber, the door closed and clamped, and 
 the steam turned on until the required temperature and press- 
 ure are reached ; this is then maintained for the time neces- 
 sary to disinfection. To meet important requirements certain 
 modifications have been made in the construction of these 
 chambers, the most important being those that aim to dis- 
 place all air from the chamber and from the meshes and pores 
 of the articles to be disinfected, by beginning the process with 
 the exhaustion of the air from the chamber, then turning in 
 the steam, again exhausting- and again turning in the steam, 
 and continuing this until all the air has been removed and 
 only steam is in contact with the object. This is manifestly 
 
286 HYGIENE OF TRANSMISSIBLE DISEASES 
 
 advantageous, otherwise portions of the chamber would con- 
 tain heated air and, as we saw above (see Dry Heat), hot air 
 has not the germicidal powers of steam. Another modifica- 
 tion aims to assist in the drying of the objects after disinfec- 
 tion, but this does not seem to be necessary, as they dry very 
 quickly if freely opened. 
 
 The pressure commonly employed in this form of disin- 
 fection varies between -^ and i atmosphere, and often more, 
 and for ordinary articles thirty minutes under from ^ to i 
 atmosphere suffice for disinfection in a properly constructed 
 apparatus. For very dense objects, such as closely pressed 
 bales of rags, dry goods, etc., an hour to an hour and a quar- 
 ter is necessary ; but by using higher pressure this time may 
 be shortened. This form of disinfector is a massive, perma- 
 nent fixture, usually constructed of iron and encased in a 
 non-conducting medium. The steam-supply is obtained from 
 a boiler either especially connected with the disinfector or 
 from one close by that is used for other purposes and which 
 may, as occasion requires, be called upon for the necessary 
 amount of steam for disinfection (Fig. 44). 
 
 A point of great importance in connection with the man- 
 agement of disinfecting apparatus, especially the large cham- 
 bers, is the precaution that should be taken to prevent the 
 reinfection of the disinfected articles by those who manipulate 
 the disinfector. 
 
 With disinfection on the small scale — /. c, domestic dis- 
 infection — the person who has handled the infected objects 
 should thoroughly disinfect his hands and arms and don a 
 sterilized apron while the apparatus is in operation, so that 
 in removing the articles after the process is complete there 
 will be no danger of his reinfecting them. 
 
 In the case of the large disinfecting plants it is customaiy 
 to have them erected in a building especially designed for 
 their accommodation. This should be constructed with a 
 central partition at right angles to the long axis of the room. 
 The disinfector should be built in this partition so that its 
 ends project into the apartments on either side of the parti- 
 tion. Running along the long axis of the building and 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 287 
 
 through the disinfectors are tracks on which run light cars or 
 trucks, on which the articles to be treated are hung or packed. 
 The car, constructed of iron netting, is of such size that it fits 
 easily into the disinfecting chamber. There are two crews of 
 attendants : the one to handle only the infected articles — /. e., 
 to load them upon the carriage, pass them into the chamber 
 and clamp the door ; the other, to handle oitly the disinfected 
 articles — i. e., to remove them from the apparatus after disin- 
 fection, and properly distribute them. 
 
 While on duty these crews do not come in contact with 
 one another. It is customary also to distinguish the two sets 
 of operators by uniforms of different colors, and under no 
 circumstances are the men or objects from the infected side 
 of the building allowed to mingle with those on the disin- 
 fected side. The only channel of communication is the 
 steam-chamber in the wall ; and it is advisable to have the 
 doors of the apparatus so arranged that both are not open 
 at the same time and can only be simultaneously opened by 
 special means. By simple mechanical contrivances it is easily 
 possible to accomplish this and thus shut off the only means 
 of direct communication between the infected and disinfected 
 sides of the apparatus. The goods to be disinfected should 
 be brought to the station, and those that have been disin- 
 fected are taken from the station in closed wagons that are 
 distinguished from each other by colors corresponding to the 
 uniforms of the crews of operators. 
 
 The uniforms of the attendants should be disinfected at the 
 end of each day, and the walls, floors, etc., of the room for 
 reception of infected articles should be cleansed each 
 day with a disinfecting solution. The room for reception 
 of disinfected articles should be provided with closets, etc., 
 and all should be kept scrupulously clean. For their own 
 protection, as well as that of those about them, the opera- 
 tors who manipulate the infected articles should be provided 
 with conveniences for bathing and personal disinfection. 
 
 In addition to heat the physical influences that are detri- 
 mental and destructive to the vitality of infective bacteria are 
 desiccation, sunlight, electricity, and vigorous agitation ; though 
 
288 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 these are not, as a rule, deliberately used for the disinfection 
 of dangerous materials. 
 
 Desiccation. — All living micro-organisms are sooner or 
 later attenuated in their pathogenic activities, and finally 
 killed, by drying. With the non-spore-forming species, and 
 particularly certain of those possessed of disease-producing 
 powers, this effect is occasionally conspicuously manifest. 
 With the spores of spore -forming bacteria, on the contrary, 
 drying requires a much longer time to attenuate and still 
 longer to kill them, the spores of certain forms retaining 
 their vitality in some cases for many years when dried 
 (anthrax). Fortunately, however, only a small proportion 
 of the known disease-producing bacteria form spores, so that 
 desiccation, even such as occurs with the ordinary environ- 
 ment of pathogenic bacteria when outside the body, is of 
 importance in arresting their development, and ultimately in 
 destroying their vitality. Thus, for instance, in laboratory 
 experiments it has been demonstrated that the spirillum of 
 Asiatic cholera when dried dies in from three hours to two 
 days, according to the degree of desiccation ; the bacilli of 
 typhoid lever, of tuberculosis, and of diphtheria resist drying 
 for a longer time, but gradually lose their vitality, and after 
 from a few weeks to months die. 
 
 The influence of drying in checking the multiplication of 
 bacteria — for none of them develop in the dry state — and of 
 gradually destroying them, is of manifest importance in the 
 spontaneous elimination of infective diseases. 
 
 Sunlight. — A large proportion of the sporeless pathogenic 
 bacteria are killed by the direct rays of the sun. In labora- 
 tory experiments this effect is very striking, many species being 
 destroyed in the presence of sunlight and air in so short a 
 time as from one to two hours. Diffuse daylight is also detri- 
 mental to pathogenic micro-organisms, though its action is less 
 energetic than is that of direct sunlight. These experiments 
 have shown that the bacillus of typhoid fever is destroyed in 
 from one and a half to two hours by direct sunlight, and in 
 five hours (l)uchncr) by diffuse daylight. Bacilhts dipJitJicricB 
 is destroyed by from one-half to one hour's exposure to the 
 
CHEMICAL AND PHYSICAL PROPHYLACTIC MEASURES. 289 
 
 direct rays of the sun ; and Koch states that the tubercle 
 bacillus is killed by sunlight in from a few minutes to several 
 hours, according to the thickness of the mass exposed, and 
 by diffuse daylight in from five to seven days. Similarly, 
 many other pathogenic and non-pathogenic species, such as 
 the pneumococcus, the pyogenic cocci, the anthrax bacillus, 
 the cholera spirillum, and others are seen to succumb to this 
 influence. 
 
 In the light of these laboratory demonstrations Esmarch 
 has endeavored to determine in how far the direct rays of the 
 sun may be employed for practical disinfection. For the tests 
 he purposely infected such articles as furniture-covers, pil- 
 lows and pillow-cases, furs, etc., and exposed them to the 
 direct rays of the sun for varying lengths of time and under 
 various conditions. As the result of these experiments he 
 does not regard direct sunlight as worthy of confidence for 
 the complete disinfection of such articles as he employed in 
 the test. Its disinfecting activity was observed oi^ly upon 
 surfaces that were freely exposed to it, and even here there 
 were irregularities in the results. The time required for its 
 best results was, moreover, so long as to make the method 
 impracticable for routine purposes. 
 
 Nevertheless, there is every reason to believe that the con- 
 tinuous daily action of the sun's rays, together with desicca- 
 tion, is an important factor in arresting the growth and 
 activities of pathogenic bacteria when they are expelled 
 from the animal body. 
 
 By laboratory experiments it has been shown that the germi- 
 cidal properties of the sun's rays were most conspicuously 
 present at the blue end of the spectrum, while the red end 
 had little or no detrimental influence upon bacterial life. 
 
 Electricity. — The germicidal value of the electrical cur- 
 rent is made evident in several ways — viz., through elec- 
 trolytic decomposition of certain chemical compounds with 
 which the bacteria may be associated, by which detrimental 
 substances are set free ; by the local elevation of temperature 
 at the positive pole ; and by the direct action of the electric 
 current upon the bacteria themselves. 
 
 19 
 
290 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 The results depend upon the strength of current and time 
 of its application. It has been successfully employed in the 
 purification of sewage and of polluted waters. 
 
 Mechanical Agitation. — The results obtained by a number 
 of investigators have demonstrated that the life-processes of 
 of several species of bacteria are markedly interfered with by 
 excessive and long-continued shaking. 
 
 In some instances the bacteria exposed to continuous 
 vibration were killed. The ordinary motion, such as bac- 
 teria experience in a current of quietly-flowing water, has 
 apparently no such effect. Melzer demonstrated that bac. 
 mcgatJicriiim when exposed for four days to continuous 
 vibration was killed, and microscopic examination showed 
 them to be actually disintegrated. Hanson has found that 
 for a particular water-bacillus slight motion was favorable, 
 whereas excessive shaking- was fatal. 
 
PRECAUTIONS IN COMMUNICABLE DISEASES. 29 1 
 
 ADDITIONAL PRECAUTIONS OF IMPORTANCE 
 IN THE MANAGEMENT OF COMMUNICABLE 
 DISEASES. 
 
 ISOLATION, THE SICK-ROOM, CLOTHING, EXCRETA, UTENSILS, 
 ATTENDANTS, ETC. 
 
 Isolation. — In the modern sense the term " isolation," as 
 applied to contagious diseases, comprehends not only the 
 separation of the infected individual from those that are not 
 infected, by placing him in a separate room or building, but 
 the complete obstruction of all the manifold channels through 
 which he may come in indirect communication with those 
 who surround him. It would be manifestly absurd to place 
 a patient in an " isolation ward " of a hospital or in a special 
 room of a private dwelling and keep him there, unless 
 care were taken that all articles with which he comes in 
 immediate contact, and which may carry the infection, were 
 also prevented from being generally used throughout the 
 building. 
 
 Formerly, when the air was regarded as the principal dis- 
 seminator of infective matters, elaborate preparations were 
 made to cut off all aerial communication between the in- 
 fected and the well, and isolation pavilions, wards, etc., were 
 so constructed as never to communicate directly with other 
 buildings in which non-contagious diseases were located ; 
 this was often the only, or at least the most conspicuous, 
 step that was taken toward the isolation of the patient. 
 While it is always proper to confine infectious and con- 
 tagious patients in separate rooms in private houses and in 
 special wards or pavilions in hospital cases, for the reason 
 that their management is thereby very much simplified, it is 
 important that we should fully understand this to be only a 
 relatively small part of the elaborate precautions now recog- 
 nized as constituting a complete and trustworthy system of 
 isolation. Modern investigation has shown us that the foun- 
 dation-work of a successful system of isolation comprises : 
 (i) Knowledge of the mode and channels through which 
 
292 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 infective matters are expelled from the body during the 
 course of special groups of infectious and contagious dis- 
 eases ; (2) the careful employment of that knowledge in the 
 application of approved means to the destruction of such 
 matters as soon as they are expelled. 
 
 Thus, for instance, during the desquamative stage of the 
 acute exanthemata — the period at which the danger from 
 contagion is believed to be greatest — it is always advisable to 
 prevent the dissemination of the morbific agents from the skin 
 in the form of epidermal dust, by anointing the entire body 
 with harmless antiseptic or disinfecting ointments. These 
 cause the epidermal scales, presumably the carriers of the 
 infection, to adhere to the patient, to whom they can do no 
 harm, and from whom they may be washed with disinfecting 
 solutions ; but it would be manifestly absurd to subject to 
 this treatment a cholera or typhoid patient, from whom the 
 infective particles escape only from the bowels, kidneys, or 
 with vomited matters. 
 
 Isolation means ino7'e than simply confining the patient to a 
 separate room or building. It comprises in addition to this 
 the employment of a separate attendant who comes in con- 
 tact with only the patient or patients for whom he or she is 
 employed to care ; the disinfection of all infective matters as 
 soon as they are passed from the patient and before they leave 
 the .sick-room ; the disinfection of all bed- and body-clothing 
 as soon as they are removed from the patient and before they 
 leave his apartment ; the provision of separate eating-utensils, 
 handkerchiefs, towels, napkins, clinical thermometers, tongue- 
 depressor, and other instrumental accessories ; the frequent 
 cleansing with disinfecting solutions of the sick-room and its 
 furniture ; the frequent general bathing of the nurse ; and 
 especially the careful disinfection of the hands after each 
 manipulation of the patient. These steps will now be treated 
 of in more or less detail. 
 
 The Sick-room. — The room should be light, of a com- 
 fortable temperature, and easily aired. Draughts should be 
 avoided. 
 
 The furniture should be of the simplest kind, and neither 
 
PRECAUTIONS IN COMMUNICABLE DISEASES. 293 
 
 carpet nor hangings should be permitted unless, in the case 
 of the latter, they be of cotton material that may readily be 
 disinfected. 
 
 The room should be provided with a small gas stove and 
 a wash-boiler of about 4 gallons capacity, or with a steam 
 sterilizer, and all small infected articles, such as napkins, 
 towels, handkerchiefs, etc., should be immersed in boiling 
 water or soda solution, or steamed, when they become soiled 
 and before being laundered. 
 
 The patient should be provided with his own eating-uten- 
 sils, which are to be boiled in soda solution after he has used 
 them. The refuse of his meals should be thrown into a cov- 
 ered receptacle containing milk of lime, or i per cent, chlo- 
 ride-of-lime solution, which should be renewed each day. 
 
 The furniture, the floor, and all horizontal surfaces, such as 
 sills, mantlepieces, etc., should be frequently — at least once 
 in two days — wiped with cloths moistened with a 3 per cent, 
 solution of carbolic acid or a i per cent, chloride-of-lime 
 solution. 
 
 The knobs of the doors should be similarly cleansed every 
 day. 
 
 These patients should be provided with separate clinical 
 thermometer, tongue-depressor, and whatever other instru- 
 ments may be frequently required in their treatment. When 
 not in use these articles should be kept in some one or an- 
 other of the disinfectant solutions after having been cleansed 
 in such solutions. They should be rinsed off in warm water 
 before being used again. 
 
 When soiled by evacuations, secretions, or excretions, the 
 body- and bed-clothing of the patient should be removed with 
 as little agitation and commotion as possible, and at once im- 
 mersed in a solution of • 
 
 Carbolic acid, 3 parts ;. 
 
 Common soft soap, 2 " 
 
 Cold water, ■ 100 " 
 
 contained in a covered vessel that is brought to the bedside. 
 This prevents the dissemination of the morbific agents that 
 
294 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 might occur if the infected clothing were carried loosely- 
 through the house or through the wards of the hospital. As 
 soon as the objects are thoroughly saturated with the solu- 
 tion, the cover is replaced, and they are allowed to soak for 
 two hours, when they may be rinsed out in clean water and 
 subjected to the ordinary processes of the laundry, begin- 
 ning preferably with boiling. 
 
 The reason for the immersion in the cold carbolic-soap 
 solution is that this not only destroys all non-spore-bearing 
 bacteria, but in the cold state dissolves out all blood and fecal 
 stains which would be rendered indelible if the soiled articles 
 were exposed at once to steam or boiling water. 
 
 Chloride of lime in 0.5 per cent, cold-water solution may 
 be substituted for the above mixture, but as it has some 
 bleaching effect had better be used only on white clothing. 
 In the writer's experiments corrosive sublimate in 1 : lOOO 
 solution has almost as great an influence in rendering blood 
 and fecal stains indelible as does hot water at from 176° F, 
 to the boiling point.^ 
 
 Clothing. — The outer clothing of the attendants should 
 always be protected by a cotton slip or coat that reaches 
 from the neck to the floor. This coat or slip should always 
 be worn when the attendant is on duty. At the end of the 
 day it should be immersed in either of the solutions named 
 above, after which it may be boiled or steamed and laun- 
 dered. All other infected clothing should be packed in 
 tightly-closing canvas bags and conveyed to the regular 
 disinfecting station to be disinfected by steam. 
 
 Where such stations are not accessible, one may have 
 recourse to the vapors of formaldehyde. The clothing 
 should be hung loosely in a closet ; a lamp for decomposing 
 paraformaldehyde tablets should be procured, and tablets 
 should be decomposed in the proportion of 75 per 1000 cu. 
 ft. of space in the closet. The door must be closed during 
 the process and should be kept closed for twenty-four hours 
 afterward. This is not as certain as steam, and is slightly 
 
 ' See 7 rails. Internat. Congress of Charities, Correction, and PkilantJiyopy\ 
 Chicago, June 12 to 18, 1893. 
 
PRECAUTIONS IN COMMUNICABLE DISEASES. 295 
 
 dangerous because of the fire, but is to be recommended for 
 domestic use when steam is not available. Infected articles 
 may also be sprayed with a 4 per cent, formalin solution, 
 though this is less trustworthy than where the nascent gas is 
 used. 
 
 The attendant should also be provided with loosely-fitting 
 carpet overshoes that should be repeatedly disinfected by 
 steam. 
 
 Whenever the attendant has occasion to leave the ward or 
 room, both the slip and overshoes should be left in the room 
 at a point close to the door of exit, so that they are in easy 
 reach when he returns. 
 
 The attendant should bathe as frequently as once a day, 
 and his hands, face, beard and hair should be frequently 
 rinsed in a i : 5000 solution of bichloride of mercury, or a i 
 per cent, solution of carbolic, or a i per cent, solution of 
 chloride of lime. 
 
 A solution that is suitable for sponging the entire body, 
 both of patient and attendant, is one consisting of i part 
 Labarraque's solution to 19 of water. 
 
 Disinfection of Stools and Sputum. — The stools of 
 all patients suffering from infective intestinal disorders, such 
 as typhoid fever, cholera, dysentery, intestinal tuberculosis, 
 etc., should be disinfected as soon as they are passed ; and 
 this should constitute a part of the routine duty of the nurse 
 in attendance. Since it is a simple process, there is no 
 excuse for its not being regularly and faithfully carried out. 
 It is the most important step in preventing the spread of 
 these maladies, for they are disseminated wholly and alone 
 through the living infective matters that are passed from the 
 bowels and kidneys of individuals suffering from them. 
 
 If each evacuation, including the urine, from every case of 
 typhoid fever, for instance, were disinfected as soon as passed 
 from the patient, it is safe to say that this disease would soon 
 disappear in large measure from among us. 
 
 Methods. — Mix with each evacuation double its volume of 
 freshly-prepared milk of lime, or double its volume of i per 
 cent, chloride-of-lime solution, or double its volume of 5 per 
 
296 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 cent, carbolic-acid solution ; or pour upon the evacuation 
 three times its volume of boilbig water or boiling 2 per cent, 
 soda solution. In either case cover the vessel and allow it 
 to stand in a safe place for from one to two hours before it is 
 emptied into the closet. 
 
 What is said in regard to intestinal evacuations applies 
 equally well to urine, vomited matters, pus, etc. 
 
 Sputum. — Sputum from tuberculosis, influenza, and pneu- 
 monia patients should be received in covered vessels contain- 
 ing either a 5 per cent, carbolic-acid solution, 2 per cent, 
 tricresol solution, or a i per cent, chloride-of-lime solution. 
 Or they may be spat into covered receptacles containing 
 moist sawdust which, with their contents, are afterward dis- 
 infected (at the end of each day) in a steam sterilizer and the 
 contents finally burned. Or it may be received in cheap, 
 pasteboard receptacles that with their contents may be 
 burned at the end of each day. 
 
 Room Disinfection. — There is as yet no single proced- 
 ure by which every article in an ordinarily furnished infected 
 room may be simultaneously and certainly disinfected. 
 
 It is always advisable therefore, where circumstances per- 
 mit, to have but little unnecessary furniture, hangings, car- 
 pets, etc., in rooms occupied by the sick. For rendering 
 rooms that have been occupied by persons suffering from 
 contagious diseases free from danger, the most trustworthy 
 plan consists in a combination of the best features of several 
 methods that have been from time to time proposed. 
 
 The steps to be taken are briefly as follows : After the 
 room has been vacated by the patient, all conspicuous cracks 
 and crevices should be sealed, the door should be closed and 
 locked, and the room kept closed for at least twenty-four 
 hours. At the end of this time formaldehyde gas should be 
 either generated in the room by the decomposition by heat 
 of from 50 to 75 tablets of polymerized formaldehyde to each 
 1000 cu. ft. of air-space, or formaldehyde gas generated from 
 its watery solution by an approved apparatus may be passed 
 into the room from without. The amount of gas employed 
 should be that given off fron^. at least i pound of formalin or 
 
PRECAUTIONS IN COMMUNICABLE DISEASES. 297 
 
 formochloral for each lOOO to 1200 cu. ft. of air-space (see 
 Formaldehyde). 
 
 After this the room should be kept closed for at least six 
 hours. This accomplishes the necessary disinfection of all 
 surfaces. 
 
 The room may then be entered and all bed-clothing, pil- 
 lows, mattresses, other clothing in closets, chests, trunks, 
 etc., should be put into canvas bags, brought for the purpose 
 by the operators, and sent at once to a disinfecting station, 
 where they are subjected to the action of steam. This com- 
 pletes the disinfection of those articles that were only super- 
 ficially acted upon by the formaldehyde gas. 
 
 In the meantime the ceiling and walls are to be wiped down 
 with cloths wrung out in 3 per cent, carbolic-acid, i : 2000 
 corrosive-sublimate, or 0.5 per cent, chloride-of-lime solution ; 
 and finally, all furniture and all horizontal surfaces, such as 
 window-sills, cornices, etc., are to be similarly wiped off, after 
 which the floor is to be scrubbed with hot soda solution of 
 about 4 per cent, strength. 
 
 In the case of hangings, valuable curtains, tapestries, car- 
 pets, etc., that might be injured by steam disinfection, it is 
 best to remove them after the action of the formaldehyde and 
 have them thoroughly beaten or shaken on some distant 
 open lot, after which they should be freely exposed to direct 
 sunlight. 
 
 The object of each of these steps is : 
 
 The keeping of the room closed for a day after its vacation 
 permits all dust to settle. 
 
 The generation of formaldehyde gas in the room disinfects 
 the dust and all exposed surfaces, so that there is danger 
 neither to the operators themselves nor of their conveying 
 infective matters. 
 
 The wiping of walls, furniture, and surfaces, and the scrub- 
 bing of the floors with disinfecting solutions insures the de- 
 struction of infective matters that may have escaped the action 
 of the formaldehyde gas. 
 
 The steaming of pillows, mattresses, bed-clothing, etc., in- 
 sures the destruction of infective matters that may have soaked 
 
298 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 into their deeper layers and escaped the action of the formal- 
 dehyde gas. 
 
 In some places sulphur dioxide gas is employed in place 
 of formaldehyde and is often the only step taken for disinfec- 
 tion, but it is doubtful if the results are ever as satisfactory or 
 as complete as when formaldehyde is properly used. 
 
 Again, the walls and surfaces are sometimes rubbed over 
 with gluten bread, to which all dust and infective particles 
 adhere, after which the bread is burned. This has no ad- 
 vantage over the cloths rung out in reliable disinfectant so- 
 lutions. 
 
 When a room has been disinfected and cleaned by the proc- 
 ess outlined above, it should be thoroughly aired for a few 
 days before it is occupied. 
 
 On closing the room preparatoiy to its disinfection, the 
 nurse or attendant whose duties it has been to seal up all 
 cracks and crevices, before leaving should doff her over-slip 
 and overshoes and leave them in the room to be disinfected 
 with the other articles. 
 
 (See personal experience in room disinfection with formal- 
 dehyde under " Formaldehyde.") 
 
 Care of the Body after Death. — It is ordinarily ad- 
 visable that the cadavers of patients who have died of the 
 most dangerous communicable diseases be at once enveloped 
 in a sheet saturated with either 5 per cent, carbolic-acid, 4 
 per cent, chloride-of-lime, or i : 1000 solution of corrosive 
 sublimate, and placed at once in the coffin in which each is 
 to be buried. 
 
 These cadavers should be buried as soon as decency per- 
 mits. The law should, and usually does, forbid public funer- 
 als in these cases. 
 
 With the less dangerous infectious diseases, however, such 
 stringent measures are not observed. The body after death 
 may be washed in either of the strong disinfecting solutions 
 mentioned, though because of their odor the carbolic-acid 
 and chloridc-of-lime solutions usually give way to the subli- 
 mate solution. 
 
 The rectum in those cases of intestinal infection should be 
 
QUARANTINE. 299 
 
 tightly plugged with cotton soaked in the sublimate or car- 
 bolic solution, and as soon as practicable the body should be 
 placed in the coffin in which it is to be buried. 
 
 It is not advisable, even in the milder infective cases, to ex- 
 pose the remains in open caskets. The body should be 
 buried or cremated ; the results of the two processes of final 
 disposal differing, as a rule, only in the time required for their 
 accomplishment. If buried, the place selected should be so 
 located as not to endanger neighboring drinking-water sup- 
 plies. 
 
 QUARANTINE. 
 
 Quarantine may be defined as the segregation or isolation 
 of such persons and objects as may be a menace to the health 
 of the surrounding community, though the common usage 
 of the term refers more to the enforced detention at ports of 
 entry of persons, personal effects, and articles of merchan- 
 dise coming by land or sea from localities in which danger- 
 ous epidemic diseases are in existence, to localities that are 
 free from them. 
 
 Its object is to prevent the importation and dissemination 
 of infectious maladies. 
 
 In its original meaning it implied the detention for forty 
 days, this being regarded as the period necessary for the 
 " self-consumption " of the morbific agents of acute epidemic 
 diseases. In its modern usage, however, the word refers 
 more to the process than to the time of its enforcement, the 
 latter feature having been modified to meet the exigencies of 
 particular cases ; that is to say, there is no longer a fixed 
 period of detention for all cases, but the length of this period 
 varies according to the period of incubation of the particular 
 disease against the importation of which the precaution is 
 being taken. 
 
 In England there is a tendency to eliminate entirely the 
 
300 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 enforced detention, the authorities preferring to rely more 
 upon the prompt notification of outbreaks of contagious dis- 
 ease and upon measures that aim to place their ports of 
 entry in such sanitary condition that epidemic diseases can- 
 not gain a foothold, than upon the systems of quarantine as 
 usually enforced. 
 
 Because of the serious embarrassment to commercial inter- 
 course that the older methods of quarantine entailed, and 
 because of the demonstrated inadequacy to close all chan- 
 nels of intercourse completely by such methods, numerous 
 congresses of experts have convened for the purpose of 
 formulating a more expeditious and trustworthy system for 
 the management of suspicious and dangerous matters arriv- 
 ing from infected districts. Though no uniform plan has 
 been adopted as a result of these debates, still it is evident 
 that the tendency, briefly stated, is to depart very widely 
 from the practices of former years and to rely more upon 
 the prompt enforcement of active, trustworthy, sanitary meas- 
 ures than upon the uncertain element of detention. 
 
 Briefly summarized, such measures comprise : 
 
 Strict sanitary supervision of all ports of entry ; the board- 
 ing and inspection of all vessels arriving from foreign ports, 
 and in special cases of all vessels, from domestic as well as 
 foreign ports. This latter is enforced when epidemic diseases 
 existing in one part of a country are liable to be conveyed to 
 another by means of maritime commerce. 
 
 The disinfection, fumigation, and cleansing of all ships found 
 upon inspection to be possible causes of infection. 
 
 The removal from the ships to the hospital of the station 
 of all passengers and crew found to be infected ; also the 
 removal to pavilions of observation of all other individuals 
 from the ship and their detention for a period of time neces- 
 sary to determine whether they are themselves infected or not. 
 
 The registration of all incoming persons, including the 
 statement as to whence they come and whither they are 
 going, and the compulsoiy notification of the authorities of 
 any form of contagious disease that may appear among such 
 persons cither cii route to or after reaching their destination. 
 
QUARANTINE. 3OI 
 
 The careful disinfection of the clothing and other personal 
 effects of the passengers and crews from infected ships. 
 
 The removal and disinfection of the cargo or ballast from 
 suspected ships or from ships coming from infected ports and 
 believed to be infected. 
 
 The reg-ular notification of the chief of the national or 
 state quarantine service, by the quarantine officer in charge, 
 of all pertaining to the ship under consideration, with a full 
 description of the steps taken to render her free from danger. 
 
 The giving of free pratique to the ship, as soon as circum- 
 stances will permit, after she has been subjected to the meth- 
 ods of cleansing and disinfection deemed proper by the quar- 
 antine authorities. 
 
 To carry out this work properly it is necessary that the 
 quarantine station be under the management of a staff of 
 trained officers who are fully impressed with the importance 
 of their work. 
 
 They should have, at their disposal a corps of assistants 
 who have been thoroughly instructed in the duties that they 
 are to perform. 
 
 The station should be located at a place of safe anchorage, 
 convenient to the channel of traffic, but sufficiently removed 
 from populous centers and from the line of travel to prevent 
 its being a source of danger to the surrounding community 
 and to non-infected vessels and to their crews. 
 
 The station should be provided with the necessary boats, 
 launches, or tugs for boarding in all weathers. 
 
 It should be provided with a steam-disinfecting plant of 
 approved pattern for the disinfection of articles of clothing 
 and of merchandise that may be brought on shore ; with 
 tanks for holding disinfecting solutions that are to be used on 
 shore ; with facilities for the bathing and personal disinfection 
 of all suspected passengers and crews from infected vessels ; 
 with a detention-pavilion for the observation of persons from 
 infected ships who are themselves at the time of quarantine 
 not actually sick of the disease against which the ship is being 
 quarantined ; with properly equipped hospitals or pavilions 
 for the treatment of all cases of contagious disease. 
 
302 HYGIENE OF TRANSMISSIBLE DISEASES. 
 
 The general sanitary condition of the station as regards 
 water-supply, food-supply, and drainage, heating and venti- 
 lation of barracks, etc., should be of the best. 
 
 All officers and assistants should have been vaccinated 
 against small-pox, and for stations having frequently to do 
 with yellow fever, it is advisable to select the staff from among 
 individuals who have already had the disease. 
 
 There should be a rigid isolation of the hospital and deten- 
 tion-pavilions and their nurses and attendants from other build- 
 ings and persons of the station. 
 
 For the expeditious disinfection of ships' holds and cabins 
 the station should be provided with a steam-vessel fully 
 equipped with provisions for generating the fumigating gases 
 in large quantities, for the liberation of hot water or steam 
 under pressure, and with pumps for the forcible ejection of 
 of disinfectants to be used in cleansing and disinfecting the 
 ship. 
 
 There should be a crematory for the disposal by fire of all 
 useless articles that may harbor infection. 
 
 In addition to maritime quarantine, to which the above 
 particularly refers, we hear of other kinds of quarantine, 
 though they differ from one another only in their application 
 to different channels through which infection may be imported 
 or spread, the object throughout being the same. Thus, for 
 example, we hear of " railroad quarantine," meaning the 
 sanitary supervision of persons and articles of merchandise 
 arriving by rail from infected localities. In its mode of ap- 
 plication it is essentially the same as maritime quarantine ; 
 of " house quarantine," meaning the prevention of inhabitants 
 of infected houses from mingling with the general public, as 
 well as the prevention of outside persons from visiting such 
 houses unless duly authorized ; of the " sanitary cordon," 
 sometimes known popularly as " shot-gun " quarantine, 
 meaning a system of isolation, sometimes unauthorized, that 
 is conducted by surrounding infected districts with a cordon 
 of armed patrols who are instructed to prevent, by force if 
 necessary, all communication between the suspicious focus 
 and the surrounding countiy. 
 
QUARANTINE. 3O3 
 
 In addition, we hear of systems of quarantine against cer- 
 tain specific diseases, as " yellow-fever quarantine," " cholera 
 quarantine," " diphtheria quarantine," indicating at once the 
 particular measures that are in force to check the spread of 
 this or that disease. 
 
 While maritime quarantine is of necessity an elaborate 
 process, as carried out at our great ports of entry, it is far 
 more easy to conduct it consistently and with advantage to 
 the public health than is inland quarantine. In the latter 
 event the channels of intercourse are so numerous that their 
 complete obstruction is a matter of practical impossibility. 
 It is here that the importance of an adequate system of noti- 
 fication of contagious diseases is seen, for it is only by this 
 means that outbreaks within our borders, originating through 
 importation, can be early recognized, and receive the sanitary 
 supervision that their gravity demands. 
 
 Quarantine was originally established to guard against the 
 spread of the plague, but as time went on it was employed 
 against additional contagious diseases, one after another, un- 
 til at the present time it may be practised against practically 
 all communicable diseases, though cholera, typhus fever, yel- 
 low fever, small-pox, and leprosy are the maladies against 
 which it is conspicuously employed. It is, however, the 
 opinion of those versed in the subject that all immigrants 
 suffering from such diseases as the acute exanthemata, dys- 
 entery, glanders, beriberi, epidemic influenza, and in fact all 
 communicable diseases, should be detained for a time neces- 
 sary to place them beyond the point of danger to those with 
 whom they may come in contact. 
 
 Note. — For details relating to the practice of quarantine in the United 
 States, see the excellent publications of the Marine Hospital Service, notably : 
 
 "Quarantine Laws and Regulations of the United States," Treasury De- 
 partment, Document No. 1677, Marine Hospital Service. 
 
 " A Precis of Quarantine Practice at National Quarantine Stations," pre- 
 pared by Passed Assist. Surgeon H. D. Geddings : Reports of U. S. Marine 
 Hospital Service, 1896, pp. 479-523. 
 
INDEX. 
 
 Acclimatization, 255 
 Acids as disinfectants, 275 
 Acquired immunity, 241 
 
 transmissibility of, from parent to 
 child, 253 
 Actinomyces, 171 
 Actinomycosis, 17 1 
 cause of, 171 
 dissemination of, 173 
 portal of infection in, 173 
 prophylaxis against, 174 
 Active immunity, 250 
 Acute croupous pneumonia, 107. See 
 
 also Pneumonia. 
 Age as a predisposing cause of disease, 
 
 27 
 Amoeba dysenterise, 97 
 Amoebic dysentery, 97 
 cause of, 97 
 distribution of, 98 
 mode of dissemination in, 98 
 portal of infection in, 99 
 prophylaxis against, 99 
 Anesthetic leprosy, 148 
 Animal parasites as a cause of disease, 
 
 53 
 diseases due to, 223 
 Animal resistance, 26 
 Ankylostomiasis, 225 
 Anthrax, 160 
 bacillus of, 160 
 cause of, 160 
 external, 163 
 in man, 162 
 internal, 164 
 prophylaxis against, 164 
 Antiseptic, 260 
 
 Antitoxic condition, 245, et seq. 
 20 
 
 Apartments, disinfection of, 208 
 Ascaris lumbricoides, 224 
 Asiatic cholera, 89 
 
 bacillus of, 89 
 
 care of dead after, 96 
 
 cause of, 89 
 
 distribution, season, race, etc., 91 
 
 mode of dissemination in, 92 
 
 portals of infection in, 94 
 
 prophylaxis against, 95 
 Attendants, clothing of, 294 
 Autoclaves for generating formalde- 
 hyde, 265 
 
 Bacillus anthracis, 160 
 
 diphtherise, ixi 
 
 icteroides, 203 
 
 influenzae, 124 
 
 leprae, 148 
 
 mallei, 166 
 
 of Asiatic cholera, 89 
 
 of bubonic plague, 127 
 
 of glanders, 166 
 
 of syphilis, I41 
 
 of typhoid fever, 63 
 
 of whooping cough, 187 
 
 of yellow fever, 203 
 
 tetani, 155 
 
 tuberculosis, 100 
 
 typhosus, 63 
 
 X, 203 
 Bacteria as causes of disease, 54 
 
 effect of desiccation on, 288 
 of electricity on, 289 
 of mechanical agitation on, 290 
 of sunlight on, 288 
 Beef tape-worm, 237 
 Bichloride of mercury, 272 
 
 305 
 
3o6 
 
 INDEX. 
 
 Black death, 128 
 
 vomit, 202 
 Body, care of, after death, 298 
 Boiling, disinfection by, 283 
 Bothriocephalus latus, 238 
 Breakbone fever, 208. See Dengue. 
 Brick-makers' anemia, 225 
 Bromine, 263 
 Bubonic plague, 126 
 
 cause of, 126 
 
 dissemination and modes of infec- 
 tion in, 130 
 
 distribution, race, season, etc., 128 
 
 prophylaxis against, 131 
 
 Cadaver, care of, after death, 298 
 Camp fever, 211 
 Carbolic acid, 269 
 Carbol-soap solution, 27 1 
 Carbol-sulphuric acid, 270 
 Care of body after death, 298 
 Causation of disease, 25 
 Causes of disease, chemical, 52 
 exciting, 51 
 mechanical, 53 
 physical,. 53 
 predisposing, 26 
 vital, 53 
 Caustic ammonia, 275 
 potassa, 275 
 soda, 275 
 Cellars, disinfection of, 279 
 Cerebrospinal fever, 118 
 meningitis, epidemic, 118 
 
 age, season, mortality, etc., 120 
 cause of, 1 18 
 distribution of, 119 
 history of, 119 
 
 modes of dissemination in, 121 
 portal of infection in, I2I 
 prophylaxis against, 123 
 Cestodes, 233 
 
 Chemical causes of disease, 52 
 disinfection, 259, 261 
 special, 277 
 Chicken-pox, 180. See also Varicella. 
 Chloride of lime, 273 
 
 Chlorine, 263 
 
 Chlorosis, Egyptian, 225 
 
 Cholera, Asiatic, 89 
 
 care of dead after, 96 
 
 cause of, 89 
 
 distribution, season, race, etc., 91 
 
 mode of dissemination in, 92 
 
 portals of infection in, 94 
 
 prophylaxis against, 95 
 
 Cisterns, disinfection of, 280 
 
 Clothing of attendants, 294 
 
 Comma bacillus, 89 
 
 Contagious diseases defined, 55 
 
 Cordon, sanitary, 302 
 
 Creolin, 272 
 
 Cresols, 271 
 
 Crowding as a predisposing cause of 
 disease, 41 
 
 Cysticercus cellulosEe, 235 
 
 Dandy fever, 208. See Dengue. 
 Death, care of body after, 298 
 Death-rate, relation of, to density of 
 population, 41 
 
 of whites and negroes compared, 33 
 Dengue, 208 
 
 dissemination of, 210 
 
 prophylaxis against, 2IO 
 Density of population and death-rate, 
 
 41 
 as a predisposing cause of disease, 
 
 41 
 
 Deodorizer, 260 
 
 Desiccation, effect on bacteria, 288 
 
 Diarrheal diseases, monthly fluctua- 
 tions in death-rates from, 48 
 
 Diphtheria, iii 
 bacillus of, III 
 cause of, 1 1 1 
 
 distribution, season, age, etc., 113 
 modes of dissemination in, 113 
 monthly variation in death-rate from, 
 
 portals of infection in, 1 15 
 prophylaxis against, 1 16 
 Diplococcus intracellularis meningiti- 
 dis, 118 
 
INDEX. 
 
 307 
 
 Direct causes of disease, 51 
 Disease, causation of, 24 
 
 exciting causes of, 51 
 
 predisposing causes of, 26 
 Disinfectants, 260 
 
 bichloride of mercury, 272 
 
 bromine, 263 
 
 carbolic acid, 269 
 
 carbol-soap solution, 271 
 
 carbol-sulphuric acid, 270 
 
 caustic ammonia, 275 
 
 caustic potassa, 275 
 
 caustic soda, 275 
 
 chloride of lime, 273 
 
 chlorine, 263 
 
 creolin, 272 
 
 cresols, 271 
 
 formaldehyde, 263 
 
 formalin, 264 
 
 hydrochloric acids, 275 
 
 milk of lime, 274 
 
 permanganate of potash, 276 
 
 silver nitrate, 273 
 
 soda solutions, 275 
 
 sulphate of iron, 276 
 
 sulphur dioxide, 262 
 
 sulphuric acid, 276 
 
 tricresol, 271 
 Disinfection, 259 
 
 by boiling, 283 
 
 by dry heat, 283 
 
 by fire, 282 
 
 by heat, 282 
 
 by physical processes, 282 
 
 by steam, 283 
 
 chemical, 261 
 
 of apartments, 208 
 
 of cellars, 279 
 
 of cisterns, 280 
 
 of evacuations, 277 
 
 of hands, 281 
 
 of privy vaults, 277 
 
 of rooms, 296 
 
 of ships, 301 
 
 of sinks, 278 
 
 of sputum, 296 
 
 of stables, 279 
 
 Disinfection of stools, 295 
 
 of urinals, 278 
 
 of water-closets, 278 
 
 of wells, 280 
 
 special chemical, 277 
 Dracontiasis, 226 
 Dracunculus medinensis, 226 
 Drying, effect of, on bacteria, 288 
 Dust-inhalation, effect of, 38 
 Dysentery, amoebic, 97. See also 
 Atncebic Dysentery. 
 
 tropical, 97 
 
 Earth as a deodorizer, 276 
 Echinococcus hominis, 238 
 Ectogenous causes of disease, 52 
 Egyptian chlorosis, 225 
 Electricity, effect of, on bacteria, 289 
 Endogenous causes of disease, 52 
 Epidemic cerebrospinal meningitis, 
 
 118 
 Evacuations, disinfection of, 277 
 Exciting causes of disease, 51 
 
 chemical, 52 
 
 mechanical, 53 
 
 physical, 53 
 
 vital, 53 
 
 Facultative parasite, 60 
 
 saprophyte, 60 
 Famine fever, 214 
 Farcy, 166 
 
 Fever, malarial, 189. See also Mala- 
 rial Fever. 
 relapsing, 214. See Relapsing 
 
 Fever. 
 scarlet, 182. See also Scarlet Fever. 
 typhoid, 63. See also Typhoid 
 
 Fever. 
 typhus, 211. See Typhus Fever. 
 yellow, 202. See also Yellow Fever. 
 Filaria medinensis, 226 
 sanguinis hominis, 227 
 diurna, 229 
 nocturna, 229 
 perstans, 229 
 Filariasis, 227 
 
3o8 
 
 INDEX. 
 
 Filtration of water in Hamburg, effect 
 on cholera, 92 
 effect on typhoid fever, 88 
 Fire, disinfection by, 282 
 Focal zone of yellow fever, 204 
 Formaldehyde, 263 
 Formalin, 263 
 Formic aldehyde, 263 
 Fungus disease of India, 174. See also 
 
 Aladura Foot. 
 P'urbringer's method of disinfecting 
 hands, 281 
 
 Garden earth as a deodorizer, 276 
 German measles, 181 
 Glanders, 166 
 
 bacillus of, 166 
 
 cause of, 166 
 
 modes of dissemination, 169 
 
 portals of infection, 169 
 
 prophylaxis against, 170 
 Gonococcus, 140 
 Gonorrhoea, 140 
 
 dissemination of, 142 
 
 modes of infection in, 142 
 
 prophylaxis against, 143 
 Great Plague of London, 129 
 Guinea-worm, 226 
 
 Hamburg, cholera in, 92 
 
 typhoid fever in, before and after 
 filtration, 88 
 Hands, disinfection of, 281 
 Heat, disinfection by^ 282 
 Heredity as a predisposing cause of 
 
 disease, 45 
 Hospital fever, 211 
 Houses of various sizes, death-rate in, 
 
 42,43 
 Hydrochloric acid, 275 
 Hydrophobia, 216. See also Rabies. 
 Hygiene, definition of, 17 
 
 Immunity, 241 
 active, 250 
 acquired, 24 1 
 natural, 253 
 
 Immunity, passive, 250 
 
 transmissibility of, from parent to 
 offspring, 253 
 Infections, suppurative and septic, 
 
 133 
 
 Infectious diseases, defined, 55 
 
 general prophylaxis against, 241 
 Influenza, 124 
 
 bacillus of, 124 
 
 cause of, 124 
 
 dissemination of, 125 
 
 mode of infection in, 126 
 
 occurrence, distribution, etc., 1 25 
 
 prophylaxis against, 126 
 Inoculation, protective, 242 
 Intermittent malarial fever, 189 
 Isolation, 291 
 
 Jail fever, 211 
 
 Jews, mortality among, 35, 36 
 
 Kny-Sprague disinfector, 285 
 Koch's postulates, 56 
 
 Labarraque's solution, 274 
 Lausen epidemic of typhoid fever, 70 
 Lepra-cells, 149 
 Leprosy, 148 
 
 bacillus of, 148 
 
 cause of, 148 
 
 dissemination of, 151 
 
 geographical distribution, race, etc., 
 150 
 
 modes of infection in, 151 
 
 prophylaxis against, 153 
 Liquor dealers, comparative mortality 
 
 of, 38 
 Liquor sodte chlorinatse, 274 
 Lobar pneumonia, 107. See also 
 
 Pnetivionia, acute croupous. 
 Lock-jaw, 155. See also Tetanus. 
 Louis's law, 27 
 Lumpy jaw, 172 
 Lyssa, 216. See also Rabies. 
 
 Madura foot, 174 
 etiology of, 175 
 
INDEX. 
 
 309 
 
 Malarial fever, 189 
 cause of, 189 
 chart of monthly variation in 
 
 death-rate from, 49 
 conditions influencing develop- 
 ment of, 197 
 geographical distribution of, 196 
 influence of air-currents on, 199 
 of rainfall on, 198 
 of season on, 199 
 intermittent, 189 
 marsh land and, 197 
 modes of infection in, 200 
 prophylaxis against, 201 
 remittent, 189 
 Malignant anthrax edema, 163 
 
 pustule, 163 
 Measles, 181 
 cause of, 181 
 German, 181 
 Mechanical agitation, effect of, on bac- 
 teria, 290 
 causes of disease, 53 
 Metacresol, 271 
 
 Miasmatic diseases, defined, 55 
 Micrococcus gonorrhoeae, 140 
 
 lanceolatus, 107 
 Milk-epidemics of diphtheria, 115 
 Milk of lime, 274 
 Miners' cachexia or chlorosis, 225 
 Mumps, 188 
 Mycetoma, 174. See also Madura 
 
 Foot. 
 Mycosis intestinalis, 164 
 Natural immunity, 253 
 
 Negroes, death-rate among, 33 
 Nematoda, 224 
 
 Novy-Waite formaldehyde generator, 
 266 
 
 Obligate parasite, 60 
 
 saprophyte, 60 
 Occupation as a predisposing cause of 
 
 disease, 37 
 Occupations, comparative mortality in 
 
 different, 40 
 
 Orthocresol, 271 
 Oxyuris vermicularis, 224 
 
 Paracresol, 271 
 
 Parasite, definition of, 59 
 
 Parasites, animal, as a cause of disease, 
 
 53 
 diseases due to, 223 
 facultative, 60 
 obligate, 60 
 Passive immunity, 250 
 Perifocal zone of yellow fever, 204 
 Permanganate of potash, 276 
 Pertussis, 186. See also Whooping 
 
 cough. 
 Philadelphia, typhoid epidemic at, 82 
 Physical cause of disease, 53 
 Plague, bubonic, 126 
 bacillus of, 127 
 
 dissemination and modes of in- 
 fection, 130 
 distribution, race, season, 128 
 prophylaxis against, 131 
 Plasmodium malariae, 189 
 crescentic forms of, 195 
 flagellated varieties of, 194 
 Plymouth, Pa., epidemic of typhoid 
 
 fever at, 78 
 Pneumococcus, 107 
 Pneumonia, acute croupous, 107 
 cause of, 107 
 
 distribution, age, sex, etc., 108 
 modes of dissemination of, 109 
 portal of infection in, 1 10 
 prophylaxis against, 1 10 
 Population, density of, 41 
 Pork tape-worm, 234 
 Predisposing causes of disease, 26, 31, 
 
 37 
 
 age, 27 
 
 density of population, 4I 
 
 heredity, 45 
 
 season, 47 
 
 sex, 29 
 Privy vaults, disinfection of, 277 
 Prophylactic measures, chemical and 
 
 physical, 259 
 
lO 
 
 INDEX. 
 
 Prophylaxis, general, against infectious 
 
 diseases, 241 
 Protective inoculation, 242 
 
 Quarantine, 299 
 Quartan fever, 1 89 
 
 Rabies, 216 
 cause of, 216 
 
 preventive inoculation against, 220 
 prophylaxis against, 219 
 symptoms of, 218 
 Race as a predisposing cause of dis- 
 ease, 31 
 Railroad quarantine, 302 
 Relapsing fever, 214 
 
 dissemination of, 215 
 distribution of, 215 
 prophylaxis against, 215 
 Remittent malarial fever, 189 
 Respiratory diseases, monthly fluctua- 
 tions in death-rate from, 47 
 Rhabdonema intestinale, 226 
 Room disinfection, 296 
 Rotheln, 181 
 Round worm, 224 
 Rubeola, 181 
 
 Sanitary cordon, 302 
 Saprophyte, definition of, 59 
 Saprophytes, facultative, 60 
 
 obligate, 60 
 Scarlatina, monthly variations in death- 
 rate from, 51 
 Season as a predisposing cause of dis- 
 ease, 47 
 Seven days' fever, 214 
 Sex as a predisposing cause of disease, 
 
 29 
 Scarlatina, monthly variations in death- 
 rate from, 51 
 Scarlet fever, 182 
 cause of, 182 
 dissemination of, 183 
 prophylaxis against, 184 
 Ship fever, 211 
 Ships, disinfection of, 301 
 
 Shot-gun quarantine, 302 
 Sick-room, precautions in, 292 
 Silver nitrate, 273 
 Sinks, disinfection of, 278 
 Small-pox, 176 
 
 cause of, 176 
 
 dissemination of, 177 
 
 historical sketch of, 176 
 
 prophylaxis against, 178 
 Soda solutions, 275 
 Species, definition of, 60 
 Spirillum cholerae Asiaticse, 89 
 Spirochseta Obermeieri, 214 
 Spotted fever, 118. See Cerebrospinal 
 Meningitis, epide?7iic ; also 2 1 1 . 
 Sputum, disinfection of, 296 
 
 in tuberculosis, 105 
 Stables, disinfection of, 279 
 Staphylococcus epidermidis albus, 134 
 
 pyogenes albus, 134 
 aureus, 132 
 citreus, 134 
 Steam, disinfection by, 283 
 
 -sterilizers, 283 
 Stools, disinfection of, 295 
 Streptococcus pyogenes, 135 
 Sulphate of iron, 276 
 Sulphur dioxide, 262 
 Sulphuric acid, 276 
 Sulphurous-acid gas, 262 
 Sunlight, effect of, on bacteria, 288 
 Suppurative and septic infections, 133 
 modes of dissemination, 136 
 portal of infection, 138 
 prophylaxis against, 138 
 Syphilis, 141 
 
 bacillus of, 141 
 
 dissemination of, 142 
 
 modes of infection in, I42 
 
 prophylaxis against, 143 
 
 T/ENIA echinococcus, 239 
 
 medio-canellata, 237 
 
 saginata, 237 
 
 solium, 234 
 Taenise, 233 
 Tape-worm, 233 
 
INDEX. 
 
 311 
 
 Tape-worm, beef, 237 
 
 pork, 234 
 Tertian fever, 189 
 Tetanus, 155 
 bacillus of, 155 
 cause of, 155 
 dissemination of, 158 
 distribution, season, race, 157 
 modes of infection in, 158 
 prophylaxis against, 159 
 Thread worm, 224 
 
 Three days' fever, 208. See Dengue. 
 Trichina spiralis, 230 
 Trichirosis, 230 
 Trichocephalus dispar, 224 
 Tricresol, 271 
 Tropical dysentery, 97. See also 
 
 Amcebic Dysentery. 
 Tuberculosis, 100 
 bacillus of, 100 
 cause of, 100 
 definition of, 100 
 distribution, race, sex, etc., loi 
 mode of disserflination, 102 
 portal of infection in, 103 
 prophylaxis against, 105 
 Tunnel disease, 225 
 Typhoid fever, 63 
 bacillus of, 63 
 cause of, 63 
 distribution, 69 
 epidemic at Philadelphia, 1897- 
 
 98, 82 
 epidemic of, 70 
 
 at Plymouth, Pa., 78 
 Lausen epidemic, 70 
 mode of dissemination, 64 
 monthly variation in death-rate 
 
 from, 50 
 portal of infection, 66 
 prophylaxis against, 66 
 Wittemburg epidemic of, 73 
 
 Typhus fever, 21 1 
 
 dissemination of, 212 
 distribution of, 21 1 
 prophylaxis against, 212 
 
 Urinals, disinfection of, 278 
 
 Vaccination, 242 
 Varicella, 180 
 cause, 180 
 
 prophylaxis against, 180 
 Venereal diseases, 140 
 dissemination, 142 
 modes of infection in, 142 
 prophylaxis against, 143 
 Vital causes of disease, 53 
 processes of immunity, 241 
 resistance, 26 
 
 Water-closets, disinfection of, 278 
 Welch's method of disinfecting the 
 
 hands, 282 
 Wells, disinfection of, 280 
 Whip-worm,^ 224 
 Whooping cough, 186 
 
 bacillus of, 187 
 
 cause, 186 
 
 prophylaxis against, 188 
 Wittemburg epidemic of typhoid fever 
 
 73 
 Wooden tongue, 172 
 
 Yellow fever, 202 
 
 bacillus of, 203 
 
 dissemination of, 206 
 
 etiology of, 203 
 
 geographical distribution of, 204 
 
 prophylaxis against, 207 
 
 race susceptibility to and immunity 
 from, 205 
 
 seasonal and geographical influ- 
 ences in, 206 
 
CATALOGUE 
 
 OF THE 
 
 MEDICAL PUBLICATIONS 
 
 OF 
 
 W. B. SAUNDERS, 
 
 No. 925 WALNUT STREET, PHILADELPHIA. 
 
 Arranged Alphabetically and Classified under Subjects* 
 
 THE books advertised in this Catalogue as being sold by subsciiption are usually to be 
 obtained from travelling solicitors, but they will be sent direct from the office of pub- 
 lication (charges of shipment prepaid) upon receipt of the prices given.. All the other 
 books advertised are commonly for sale by booksellers in all parts of the United States; but 
 books will be sent to any address, carriage prepaid, on receipt of the published price. 
 
 Money may be sent at the risk of the publisher in either of the following ways : A post- 
 office money order, an express money order, a bank check, and in a registered letter. Money 
 sent in any other way is at the risk of the sender. 
 
 See pages 30, 3J, for a List of Contents classified according to subjects. 
 
 LATEST PUBLICATIONS. 
 
 International Text-Book of Sttrgfery. See page 32. 
 
 American Text-Book of Surgfery — Third (Revised) Edition. See page 5. 
 
 American Text-Book of Dis* of Eye, Ear, Nose, and Throat. Page 3. 
 
 American Text-Book of Genito-Urinary and Skin Diseases. Page 4. 
 
 Heisler^s Embryologfy. See page 32. 
 
 Nancrede^s Principles of Surgery. See page 32. 
 
 Jackson's Diseases of the Eye. See page 32. 
 
 Kyle on the Nose and Throat. See page J5. 
 
 Pryo/s Pelvic Inflammations. See pages J9 and 32. 
 
 Abbott's Hygiene of Transmissible Diseases. See page 32. 
 
 Anders' Practice of Medicine — Third (Revised) Edition. See page 6. 
 
 Vierordt's Medical Diagfnosis — Fourth (Revised) Edition. See page 29. 
 
 Church and Peterson's Nervous and Mental Diseases. See page 8. 
 
 Da Costa's Surgery— Revised and Enlarged Edition. See page JO. 
 
 Saunders' Medical Hand-Atlases. See page 2. 
 
 Griffith on the Baby — Revised Edition. See page 12. 
 
 Butler's Materia Medica and Therapeutics — Third (Revised) Ed. Page 8. 
 
 De Schweinitz's Diseases of the Eye^-Third (Revised) Ed. See page JO. 
 
 Vecki's Sexual Impotence. See page 28. 
 
 Stoney's Materia Medica for Nurses. See page 28. 
 
 McFarland's Pathogenic Bacteria — Revised Edition. See page 17. 
 
 American Pocket Medical Dictionary — Second (Revised) Ed. Page JO. 
 
 Stengel's Text-Book of Pathology. Second Edition. See page 26. 
 
 Hirst's Text-Book of Obstetrics. See page J3. 
 
SAUNDERS^ MEDICAL HAND-ATLASES, 
 
 The series of books included under this title consists of authorized translations into 
 English of the world-famous Lehmann Medicinische Handatlanten, which for sci- 
 entifc accuracy, pictorial beauty, compactness, and cheapness surpass any similar 
 volumes ever published. Each volume contains from 50 to 100 colored plates, executed 
 by the most skilful German lithographers, besides numerous illustrations in the text. There 
 is a full and appropriate description of each plate, and each book contains a condensed 
 but adequate outline of the subject to which it is devoted. 
 
 One of the most valuable features of these atlases is that they offer a ready and satis- 
 factory substitute for clinical observation. To those unable to attend important clinics 
 these books will be absolutely indispensable. 
 
 In planning this series ot books arrangements were made with representative publishers 
 in the chief medical centers of the world for the publication of translations of the atlases 
 into nine different languages, the lithographic plates for ail these editions being made in Ger- 
 many, where work of this kind has been brought to the greatest perfection. The expense of 
 making the plates being shared by the various publishers, the cost to each one was materially 
 reduced. Thus by reason of their universal translation and reproduction, the publish- 
 ers have been enabled to secure for these atlases the best artistic and professional 
 talent, to produce them in the most elegant style, and yet to offer them at a price 
 heretofore unapproached in cheapness. The success of the undertaking is demon- 
 strated by the fact that the volumes have already appeared in nine different languages 
 — German, English, French, Italian, Russian, Spanish, Danish, Swedish, and Hungarian, 
 
 In view of the striking success of these works, Mr. Saunders has contracted with the 
 publisher of the original German edition for one hundred thousand copies of the atlases. 
 In' consideration of this enormous undertaking, the publisher has been enabled to prepare 
 and furnish special additional colored plates, making the series even handsomer and more 
 complete than was originally intended. 
 
 As an indication of the practical value of the atlases and of the favor with which they 
 have been received, it should be noted that the Medical Department of the U. S. Army 
 has adopted the "Atlas of Operative Surgery " as its standard, and has ordered the book in 
 large quantities for distribution to the various regiments and army posts. 
 
 The same careful and competent editorial supervision has been secured in the 
 English edition as in the originals, the translations being edited by the leading American 
 specialists in the different subjects. 
 
 NOW READY. 
 
 Atlas of Internal Medicine and Clinical Diagnosis. By Dr. Chr. Jakob, of Erlangen. Edited 
 by Augustus A. Eshnek, M.D., Professor of Clinical Medicine in the Philadelphia Polyclinic; At- 
 tendinR Physician to the Philadelphia Hospital. 68 colored plates, and 64 illustrations in the text. 
 Cloth, $3.00 net. 
 
 Atlas of Legal Medicine. By Dr. E. R. von Hofmann, of Vienna. Edited by Frederick Peter- 
 son, M.D., Clinical Professor of Mental Diseases, Woman's Medical College, New York; Chief 
 of Clinic, Nervous Dept., College of Physicians and Surgeons, New York. With 120 colored fig- 
 ures on 56 plates, and 193 beautiful half-tone illustrations. Cloth, J3.50 net. 
 
 Atlas of Diseases of the Larynx. By Dr. L. GriJnwald, of Munich. Edited by Charles P. 
 Grayson, M.D., Lecturer on Laryngology and Rliinology in the University of Pennsylvania; 
 Physician-in-Cliarge, Throat and Nose Department, Hospital of the University of Pennsylvania. 
 With 107 colored figures on 44 plates, and 25 text-illustrations. Cloth, $2.50 net. 
 
 Atlas of Operative Surgery. By Dr. O. Zuckkrkandl, of Vienna. Edited by J. Chalmers 
 
 DaCo-STA, M.D., Clinical Professor of Surgeiy, Jellei.son Medical College, Philadelphia; Surgeon 
 to the Philadelphia Hospital. With 24 colored plates, and 217 text illustrations. Cloth, $3.00 net. 
 
 Atlas of Syphilis and tne Venereal Diseases. By Prof. Dr. Franz Mracek, of Vienna. Edited 
 by L. Bolton Bangs, M. D., Professor of Genito-Urinary Surgery, University and Bellevue Hospi- 
 tal Medical College, New York. With 71 colored plates, 16 black-and-white illustrations, and 122 
 pages of text. Cloth, ;$j. 50 net. 
 
 Atlas of External Diseases of the Eye. By Dk. O. Haab, of Zurich. Edited by G. E. 
 UK SciiwEiNiTZ, IVL IJ., Professor of Ophthalmology, Jefferson Medical College, Philadelphia. 
 With 76 colored illusuatioiis on 40 plates, and 228 pages of text. Cloth, $3.00 net. 
 
 Atlas of Skin Diseases. 15y Pkof. Dk. Franz Mrackk, of Vienna. F.diied by Henry W. Stelwagon, 
 M. v., Clinical Professor of Dermatology, Jefferson Medical College, Philadelphia. 63 colored plates, 
 39 beautiful half-tjiie illustrations, and 200 pages of text. Cloth, $i.5o net. 
 
 IN PREPARATION. 
 
 Atlas of Pathological Histology. Atlas of Operative Gynecology. 
 
 Atlas of Orthopedic Surgery. Atlas of Psychiatry. 
 
 Atlas of General Surgery. Atlas of Diseases of the Ear. 
 
THE AMERICAN TEXT-BOOK SERIES. 
 
 AN AMERICAN TEXT=BOOK OF APPLIED THERAPEUTICS. 
 
 By 43 Distinguished Practitioners and Teachers. Edited by James C. 
 Wilson, M.D., Professor of the Practice of Medicine and of Clinical 
 Medicine in the Jefferson Medical College, Philadelphia. One hand- 
 some imperial octavo volume of 1326 pages. Illustrated. Cloth, 
 ^7.00 net; Sheep or Half Morocco, ^8.00 net. Sold by Subscription. 
 
 " As a work either for study or reference it will be of great value to the practitioner, as 
 it is virtually an exposition of such clinical therapeutics as experience has taught to be ol 
 the most value. Taking it all in all, no recent publication on therapeutics can be compared 
 with this one in practical value to the working physician." — Chicago Clinical Review. 
 
 " The whole field of medicine has been well covered. The work is thoroughly prac- 
 tical, and while it is intended for practitioners and students, it is a better book for the general 
 practitioner than for the student. The young practitioner especially will find it extremely 
 suggestive and helpful." — The Indian Lancet. 
 
 AN AMERICAN TEXT=BOOK OF THE DISEASES OF CHILDREN. 
 Second Edition, Revised. 
 
 By 65 Eminent Contributors. Edited by Louis Starr, M. D., Con- 
 sulting Pediatrist to the Maternity Hospital, etc. ; assisted by Thomp- 
 son S. Westcott, M. D., Attending Physician to the Dispensary 
 for Diseases of Children, Hospital of the University of Pennsyl- 
 vania. In one handsome imperial octavo volume of 1244 pages, 
 profusely illustrated. Cloth, $7.00 net; Sheep or Half Morocco, 
 ^8.00 net. Sold by Subscriptiott. 
 
 " This is far and away the best text-book on children's diseases ever published in the 
 English language, and is certainly the one which is best adapted to American readers. 
 We congratulate the editor upon the result of his work, and heartily commend it to the 
 attention of every student and practitioner." — American Journal of the Medical Sciences. 
 
 AN AMERICAN TEXT=BOOK OF DISEASES OF THE EYE, EAR, 
 NOSE, AND THROAT. 
 
 By 58 Prominent Specialists. Edited by G. E. de Schweinitz, M.D., 
 Professor of Ophthalmology in the Jefferson Medical College, Phila- 
 delphia ; and B. Alexander Randall, M.D., Professor of Diseases 
 of the Ear in the University of Pennsylvania. Imperial octavo, 1251 
 pages; 766 illustrations, 59 of them in colors. Cloth, $7.00 net; Sheep 
 or Half Morocco, ^8.00 net. Sold by Subscription. 
 
 likwtrated Catalogue of the ** American Text-Books*' sent free upon applicatioiu 
 
4 Medical Pahlications of W. B. Saunders. 
 
 AN AMERICAN TEXT=BOOK OF GENITO=URINARY AND SKIN 
 DISEASES. 
 
 By 47 Eminent Specialists and Teachers. Edited by L. Boltok 
 Bangs, M. D., Professor of Genito- Urinary Surgery, University and 
 Bellevue Hospital Medical College, New York ; and W. A. Hard- 
 AWAY, M. D., Professor of Diseases of the Skin, Missouri Medical 
 College. Imperial octavo volume of 1229 pages, with 300 engravings 
 and 20 full-page colored plates. Cloth, $7.00 net; Sheep or Half 
 Morocco, $8.00 net. So/d by Subscription. 
 "This volume is one of the best yet issued of the puhhsher's series of ' American Text- 
 Books.' The list of contributors represents an extraordinary array of talent and extended 
 experience. The book will easily take the place in comprehensiveness and value of the 
 half dozen or more costly works on these subjects which have heretofore been necessary to 
 a well-equipped library." — New York Polyclinic. 
 
 AN AMERICAN TEXT=BOOK OF GYNECOLOGY, MEDICAL AND 
 SURGICAL. Second Edition, Revised. 
 
 By 10 of the Leading Gynecologists of America. Edited by J- M. 
 Baldy, M. D., Professor of Gynecology in the Philadelphia Polyclinic, 
 etc. Handsome imperial octavo volume of 718 pages, with 341 illus- 
 trations in the text, and 38 colored and half-tone plates. Cloth, $6.00 
 net; Sheep or Half Morocco, $7.00 net. Sold by Subscription. 
 
 " It is practical from beginning to end. Its descriptions of conditions, its recommen- 
 dations for treatment, and above all the necessary technique of different operations, are 
 clearly and admirably presented. . . . It is well up to the most advanced views of the 
 day, and embodies all the essential points of advanced American gynecology. It is destined 
 to make and hold a place in gynecological literature which will be peculiarly its own." — 
 Medical Record, New York. 
 
 AN AMERICAN TEXT=BOOK OF LEGAL MEDICINE AND TOXI- 
 COLOGY. 
 
 Edited by Frederick Peterson, M.D., Clinical Professor of Mental 
 Diseases in the Woman's Medical College, New York; Chief of Clinic, 
 Nervous Department, College of Physicians and Surgeons, New York ; 
 and Walter S. Haines, M.D., Professor of Chemistry, Pharmacy, 
 and Toxicology in Rush Medical College, Chicago. In Preparation. 
 
 AN AMERICAN TEXT=BOOK OF OBSTETRICS. 
 
 By 15 Eminent American Obstetricians. Edited by Richard C. Nor- 
 Ris, M.D.; Art Editor, Robert L. Dickinson, M.D. One handsome 
 imperial octavo volume of 1014 pages, with nearly 900 beautiful colored 
 and half-tone illustrations. Cloth, $7.00 net; Sheep or Half Morocco, 
 ^8.00 net. Sold by Subscription. 
 
 " Permit me to say that your American Text-Book of Obstetrics is the most magnificent 
 medical work that I have ever seen. I congratulate you and thank you for this superb work, 
 which alone is sufficient to place you first in the ranks of medical publishers." — Alexander 
 J. C. .Skenp:, Professor of Gynecology in the Long Island College Hospital, Brooklyn, N. Y. 
 
 " This is the most sumptuously illustrated work on midwifery that has yet appeared. In 
 the number, the excellence, and the beauty of production of the illustrations it far surpasses 
 every other book upon the subject. This feature alone makes it a work which no medical 
 library should omit to purchase." — British Medical Journal. 
 
 " yVs an authority, as a book of reference, as a ' working book ' for the student or prac- 
 titioner, we commend it because we believe there is no better." — American Journal of the 
 Medical Sciences. 
 
 Illustrated Catalogue of the "American Text-Books " sent free upon application. 
 
Medical Publications of W, B, Saunders. 5 
 
 AN AMERICAN TEXT=BOOK OF PATHOLOGY. 
 
 Edited by John Guiteras, M.D., Professor of General Pathology and 
 of Morbid Anatomy in the University of Pennsylvania ; and David 
 RiESMAN, M.D. , Demonstrator of Pathological Histology in the 
 University of Pennsylvania. In Preparation. 
 
 AN AMERICAN TEXT=BOOK OF PHYSIOLOGY. 
 
 By I o of the Leading Physiologists of America. Edited by William 
 H. Howell, Ph.D., M.D., Professor of Physiology in the Johns Hop- 
 kins University, Baltimore, Md. One handsome imperial octavo 
 volume of 1052 pages. Illustrated. Cloth, ^6.00 net; Sheep or Half 
 Morocco, ^7.00 net. Sold by Subscription. 
 
 " We can commend it most heartily, not only to all students of physiology, but to every 
 physician and pathologist, as a valuable and comprehensive work of reference, written by 
 men who are of eminent authority in their own special subjects." — London Lancet. 
 
 " To the practitioner of medicine and to the advanced student this volume constitutes, 
 we believe, the best exposition of the present status of the science of physiology in the 
 English language." — American Jou7'nal of the Medical Sciences. 
 
 AN AMERICAN TEXT=BOOK OF SURGERY. Third Edition. 
 
 By II Eminent Professors of Surgery. Edited by William W. Keen, 
 M.D., LL.D., and J. William White, M.D., Ph.D. Handsome im- 
 perial octavo volume of 1230 pages, with 496 wood-cuts in the text, 
 and 37 colored and half-tone plates. Thoroughly revised and enlarged, 
 with a section devoted to " The Use of the Rontgen Rays in Surgery." 
 Cloth, ^7.00 net; Sheep or Half Morocco, $8.00 net. 
 
 *' Personally, I should not mind it being called THE Text-Book (instead of A Text- 
 Book) , for I know of no single volume which contains so readable and complete an account 
 of the science and art of Surgery as this does." — Edmund Owen, F.R.C.S., Member of 
 the Board of Examiners of the Royal College of Surgeons, England. 
 
 " If this text-book is a fair reflex of the present position of American surgery, we must 
 admit it is of a very high order of merit, and that English surgeons will have to look very 
 carefully to their laurels if they are to preserve a position in the van of surgical practice." — 
 London Lancet. 
 
 AN AMERICAN TEXT=BOOK OF THE THEORY AND PRACTICE 
 OF MEDICINE. 
 
 By 12 Distinguished American Practitioners. Edited by William 
 Pepper, M.D., LL.D., Professor of the Theory and Practice of Medi- 
 cine and of Clinical Medicine in the University of Pennsylvania. Two 
 handsome imperial octavo volumes of about 1000 pages each. Illus- 
 trated. Prices per volume : Cloth, ^5.00 net ; Sheep or Half Morocco, 
 ^6.00 net. Sold by Subscription. 
 
 •' I am quite sure it will commend itself both to practitioners and students of medicine, 
 and become one of our most popular text-books." — Alfred Loomis, M.D., LL.D,, Pro- 
 fessor of Pathology and Practice of Medicine, University of the City of New York. 
 
 " We reviewed the first volume of this work, and said : ' It is undoubtedly one of the 
 best text-books on the practice of medicine which we possess. ' A consideration of the 
 second and last volume leads us to modify that verdict and to say that the completed work 
 is in our opinion the best of its kind it has ever been our fortune to see." — New York Medical 
 Journal. 
 
 . Illustrated Catalogue of the ** American Text-Books*' sent free upon application. 
 
6 Medical Publications of W. B. Saunders. 
 
 AN AMERICAN YEAR-BOOK OF MEDICINE AND SURGERY. 
 
 A Yearly Digest of Scientific Progress and Authoritative Opinion in all 
 branches of Medicine and Surgery, drawn from journals, monographs, 
 and text-books of the leading American and Foreign authors and 
 investigators. Collected and arranged, with critical editorial com- 
 ments, by eminent American specialists and teachers, under the general 
 editorial charge of George M. Gould, M.D. One handsome imperial 
 octavo volume of about 1200 pages. Uniform in style, size, and 
 general make-up with the "American Text-Book" Series. Cloth, 
 ^6.50 net ; Half Morocco, ^7.50 net. So/d by Subscription. 
 
 " It is difficult to know which to admire most — the research and industry of the distin- 
 guished band of experts whom Dr. Gould has enlisted in the service of the Year-Book, or the 
 wealth and abundance of the contributions to every department of science that have been 
 deemed worthy of analysis. . . . It is much more than a mere compilation of abstracts, 
 for, as each section is entrusted to experienced and able contributors, the reader has the 
 advantage of certain critical commentaries and expositions . . . proceeding from writers 
 fully qualified to perform these tasks. . . . It is emphatically a boolc which should find 
 a place in every medical library, and is in several respects more useful than the famous 
 ' Jahrbiicher ' of Germany." — London Lancet. 
 
 THE AMERICAN POCKET MEDICAL DICTIONARY. 
 
 [See Dorland'''S Pocket Dictionary, page 10.] 
 
 ANDERS' PRACTICE OF MEDICINE. Third Revised Edition. 
 A Text-Boole of the Practice of Medicine. By James M. Anders, 
 M.D., Ph.D., LL.D., Professor of the Practice of Medicine and of 
 Clinical Medicine, Medico-Chirurgical College, Philadelphia. In one 
 handsome octavo volume of 1292 pages, fully illustrated. Cloth, 
 ^5.50 net; Sheep or Half Morocco, ^6.50 net. 
 
 " It is an excellent book, — concise, comprehensive, thorough, and up to date. It is a 
 credit to you ; but, more than that, it is a credit to the profession of Philadelphia — to us." 
 James C. Wilson, Professor of the Practice of Medicine and Clinical Medicine, Jefferson 
 Medical College, Philadelphia. 
 
 ASHTON'S OBSTETRICS. Fourth Edition, Revised. 
 
 Essentials of Obstetrics. By W. Easterly Ashton, M.D., Pro. 
 fessor of Gynecology in the Medico-Chirurgical College, Philadelphia. 
 Crown octavo, 252 pages; 75 illustrations. Cloth, ^i. 00; interleaved 
 for notes, ^1.25. 
 
 [See Saunders' Question- Cotnpends, page 21.] 
 
 " Embodies the whole subject in a nut-shell. We cordially recommend it to our read- 
 ers." — Chicago Medical Times. 
 
 BALL'S BACTERIOLOGY. Third Edition, Revised. 
 
 Essentials of Bacteriology ; a Concise and Systematic Introduction 
 to the Study of Micro-organisms. By M. V. Ball, M.D., Bacteriol- 
 ogist to St. Agnes' Hospital,' Philadelphia, etc. Crown octavo, 218 
 pages; 82 illustrations, some in colors, and 5 plates. Cloth, jgi.oo; 
 interleaved for notes, $1.25. 
 
 [See Samiders' Question- Comfends, page 21.] 
 
 " The student or practitioner can readily obtain a knowledge of the subject from a perusal 
 of this book. The illustrations are clear and satisfactory." — Medical Record, New York. 
 
Medical Publications of W. B. Saunders. 7 
 
 BASTIN'S BOTANY. 
 
 Laboratory Exercises in Botany. By Edson S. Bastin, M.A., 
 late Professor of Materia Medica and Botany, Philadelphia College of 
 Pharmacy. Octavo volume of 536 pages, with 87 plates. Cloth, $2.50. 
 
 " It is unquestionably the best text-book on the subject that has yet appeared. The 
 work is eminently a practical one. We regard the issuance of this book as an important 
 event in the history of pharmaceutical teaching in this country, and predict for it an unquali- 
 fied success." — Alumni Jieport to the Philadelphia College of Pharjnacy. 
 
 ' ' There is no work like it in the pharmaceutical or botanical literature of this country, 
 and we predict for it a wide circulation." — Americati Jotimal of Pharmacy, 
 
 BECK'S SURGICAL ASEPSIS. 
 
 A Manual of Surgical Asepsis. By Carl Beck, M.D., Surgeon to 
 S,t. Mark's Hospital and the New York German Poliklinik, etc. 306 
 pages; 65 text-illustrations, and 12 full-page plates. Cloth, ^1.25 net. 
 
 "An excellent exposition of the 'very latest' in the treatment of wounds as practised 
 by leading German and American surgeons." — Birminghatn (Eng.) Medical Review. 
 
 " This little volume can be recommended to any who are desirous of learning the details 
 of asepsis in surgery, for it will serve as a trustworthy guide." — London Lancet. 
 
 BOISLINIERE'S OBSTETRIC ACCIDENTS, EMERGENCIES, AND 
 OPERATIONS. 
 Obstetric Accidents, Emergencies, and Operations. By L. Ch. 
 
 BoisLiNiERE, M.D., late Emeritus Professor of Obstetrics, St. Louis 
 Medical College. 381 pages, handsomely illustrated. Cloth, ;^2.oo net. 
 
 " It is clearly and concisely written, and is evidently the work of a teacher and practi- 
 tioner of large experience." — B^'itish Medical fotirnal. 
 
 " A manual so useful to the student or the general practitioner has not been brought to 
 our notice in a long time. The field embraced in the title is covered in a terse, interesting 
 way." — Yale Medical Journal. 
 
 BROCKWAY'S MEDICAL PHYSICS. Second Edition, Revised. 
 Essentials of Medical Physics. By Fred J. Brockway, M.D., 
 Assistant Demonstrator of Anatomy in the College of Physicians and 
 Surgeons, New York. Crown octavo, 330 pages ; 155 fine illustrations. 
 Cloth, $1.00 net; interleaved for notes, ^1.25 net. 
 
 [See Saunders^ Qtcestion-Compends, page 21.] 
 
 " The student who is well versed in these pages will certainly prove qualified to com« 
 prebend with ease and pleasure the great majority of questions involving physical principles 
 likely to be met with in his medical studies." — American Practitioner and News. 
 
 "We know of no manual that affords the medical student a better or more concise 
 exposition of physics, and the book may be commended as a most satisfactory presentation 
 of those essentials that are requisite in a course in medicine." — Neiv York Medical Jou7-nal, 
 
 " It contains all that one need know on the subject, is well written, and is copiously 
 illustrated." — Medical Record, New York. 
 
 BURR ON NERVOUS DISEASES. 
 
 A Manual of Nervous Diseases. By Charles W. Burr, M.D., 
 Clinical Professor of Nervous Diseases, Medico-Chirurgical College, 
 Philadelphia ; Pathologist to the Orthopedic Hospital and Infirmary 
 for Nervous Diseases; Visiting Physician to St. Joseph's Hospital, etc. 
 In PreparatAon. 
 
8 Medical Publications of W. B. Saunders. 
 
 BUTLER'S MATERIA MEDICA, THERAPEUTICS, AND PHAR- 
 MACOLOGY. Third Edition, Revised. 
 A Text=Book of Materia Medica, Therapeutics, and Pharma- 
 cology. By George F. Butler, Ph.G., M.D., Professor of Materia 
 Medica and of Clinical Medicine in the College of Physicians and 
 Surgeons, Chicago ; Professor of Materia Medica and Therapeutics, 
 Northwestern University, Woman's Medical School, etc. Octavo, 874 
 pages, illustrated. Cloth, ^4.00 net; Sheep, ^5.00 net. 
 
 " Taken as a whole, the book may fairly be considered as one of the most satisfactory 
 of any single-volume works on materia medica in the market,"— yozirnal of tAe American 
 Medical Association. 
 
 CERNA ON THE NEWER REMEDIES. Second Edition, Revised. 
 Notes on the Newer Remedies, their Therapeutic Applications 
 and Modes of Administration. By David Cerna, M.D., Ph.D., 
 formerly Demonstrator of and Lecturer on Experimental Therapeutics 
 in the University of Pennsylvania ; Demonstrator of Physiology in the 
 Medical Department of the University of Texas. Rewritten and 
 greatly enlarged. Post-octavo, 253 pages. Cloth, ^1.25. 
 
 " The appearance of this new edition of Dr. Cerna's very valuable work shows that it 
 is properly appreciated. The book ought to be in the possession of every practising physi- 
 cian." — ISferu York Aledical Journal. 
 
 CHAPIN ON INSANITY. 
 
 A Compendium of Insanity. By John B. Chapin, M.D., LL.D., 
 
 Physician-in-Chief, Pennsylvania Hospital for the Insane ; late; Physi- 
 cian-Superintendent of the Willard State Hospital, New York ; Hon- 
 orary Member of the Medico-Psychological Society of Great Britain, 
 of the Society of Mental Medicine of Belgium. i2mo, 234 pages, 
 illustrated. Cloth, ^1.25 net. 
 
 " The practical parts of Dr. Chapin's book are what constitute its distinctive merit. We 
 desire especially to call attention to the fact that on the subject of therapeutics of insanity 
 the work is exceedingly valuable. It is not a made book, but a genuine condensed thesis, 
 which has all the value of ripe opinion and all the charm of a vigorous and natural style." — 
 Philadelphia Aledical Jou7-nal. 
 
 CHAPMAN'S MEDICAL JURISPRUDENCE AND TOXICOLOGY. 
 Second Edition, Revised. 
 Medical Jurisprudence and Toxicology. By Henry C. Chapman, 
 M.D., Professor of Institutes of Medicine and Medical Jurisprudence 
 in the Jefferson Medical College of Philadelphia. 254 pages, with 55 
 illustrations and 3 full-page plates in colors. Cloth, ^1.50 net. 
 
 "The best book of its class for the undergraduate that we know of." — N'ezv York 
 Medical Times. 
 
 CHURCH AND PETERSON'S NERVOUS AND MENTAL DISEASES. 
 Nervous and Mental Diseases. By Archibald Church, M. D., 
 Professor of Mental Di.seases and Medical Jurisprudence in the North- 
 western University Medical School, Chicago ; and Frederick Peter- 
 .son, M. D., Clinical Professor of Mental Diseases, Woman's Medical 
 College, N. Y.; Chief of Clinic, Nervous Dept., College of Physi- 
 cians and Surgeons, N. Y. Handsome octavo volume of 843 pages, 
 profusely illustrated. Cloth, $5.00 net; Half Morocco, $6.00 net. 
 
Medical Publications of W. B. Saunders. 9 
 
 CLARKSON'S HISTOLOGY. 
 
 A Text=Book of Histology, Descriptive and Practical. By 
 
 Arthur Clarkson, M.B., CM. Edin., formerly Demonstrator oif 
 Physiology in the Owen's College, Manchester; late Demonstrator of 
 Physiology in Yorkshire College, Leeds. Large octavo, 554 pages; 
 22 engravings in the text, and 174 beautifully colored original illustra- 
 tions. Cloth, strongly bound, ^4.00 net. 
 
 " The work must be considered a valuable addition to the list of available text- books, 
 and is to be highly recommended." — New York Medical Journal. 
 
 ' ' This is one of the best works for students we have ever noticed. We predict that the 
 book will attain a well-deserved popularity among our students." — Chicago Medical Recorder. 
 
 CLIMATOLOGY. 
 
 Transactions of the Eighth Annual Meeting of the American 
 Climatological Association, held in Washington, September 22-25, 
 1891. Forming a handsome octavo volume of 276 pages, uniform with 
 remainder of series. (A limited quantity only.) Cloth, ^1.50. 
 
 COHEN AND ESHNER'S DIAGNOSIS. 
 
 Essentials of Diagnosis. By Solomon Solis-Cohen, M.D., Pro- 
 fessor of Clinical Medicine and Applied Therapeutics in the Philadel- 
 phia Polyclinic ; and Augustus A. Eshner, M.D., Professor of Clinical 
 Medicine in the Philadelphia Polyclinic. Post-octavo, 382 pages; 55 
 illustrations. Cloth, ^1.50 net. 
 
 [See Saunders'' Question- Compends, page 21.] 
 
 " We can heartily commend the book to all those who contemplate purchasing a 'com- 
 pend.' It is modern and complete, and will give more satisfaction than many other works 
 which are perhaps too prolix as well as behind the times." — Medical Review, St. Louis. 
 
 CORWIN'S PHYSICAL DIAGNOSIS. Third Edition, Revised. 
 
 Essentials of Physical Diagnosis of the Thorax. By Arthur 
 M. Corwin, A.M., M.D., Demonstrator of Physical Diagnosis in Rush 
 Medical College, Chicago ; Attending Physician to Central Free Dis- 
 pensary, Department of Rhinology, Laryngology, and Diseases of the 
 Chest, Chicago. 219 pages, illustrated. Cloth, flexible covers, ^1.25 net. 
 
 "It is excellent. The student who shall use it as his guide to the careful study of 
 physical exploration upon normal and abnormal subjects can scarcely fail to acquire a good 
 working knowledge of the subject." — Philadelphia Polyclinic. 
 
 "A most excellent little work. It brightens the memory of the differential diagnostic 
 signs, and it arranges orderly and in sequence the various objective phenomena to logical 
 solution of a careful diagnosis." — Jotirnal of Nervous and Mental Diseases. 
 
 CRAGIN'S GYNECOLOGY. Fourth Edition, Revised. 
 
 Essentials of Gynaecology. By Edwin B. Cragin, M. D., Lecturer 
 in Obstetrics, College of Physicians and Surgeons, New York. Crown 
 octavo, 200 pages; 62 illustrations. Cloth, $1.00 ; interleaved for notes, 
 
 [See Saunders' Question- Compends, page 21.] 
 
 " A handy volume, and a distinct improvement on students' compends in general. No 
 author who was not himself a practical gynecologist could have consulted the student's needs 
 so thoroughly as Dr. Cragin has done." — Medical Record, New York. 
 
10 Medical Publications of W. B. Saunders. 
 
 CROOKSHANK'S BACTERIOLOGY. Fourth Edition, Revised. 
 
 A Text=Book of Bacteriology. By Edgar M. Crookshank, M.B., 
 Professor of Comparative Pathology and Bacteriology, King's College, 
 London. Octavo volume of 700 pages, with 273 engravings and 22 
 original colored plates. Cloth, $6.50 net; Half Morocco, ^7.50 net. 
 
 " To the student who wishes to obtain a good resume of what has been done in bacteri- 
 ology, or who wishes an accurate account of the various methods of research, the book may 
 be recommended with confidence that he will find there what he requires." — Lo7idon Lancet. 
 
 Da COSTA'S SURGERY. Second Ed., Revised and Greatly Enlarged. 
 Modern Surgery, General and Operative. By John Chalmers 
 DaCosta, M.D., Clinical Professor of Surgery, Jefferson Medical 
 College, Philadelphia ; Surgeon to the Philadelphia Hospital, etc. 
 Handsome octavo volume of 900 pages, profusely illustrated. Cloth, 
 ^4.00 net; Half Morocco, 1^5.00 net. 
 
 "We know of no small work on surgery in the English language which so well fulfils 
 the requirements of the modern student." — Medico-Chirurgical Journal, Bristol, England. 
 
 DE SCHWEINITZ ON DISEASES OF THE EYE. Third Edition, 
 Revised. 
 Diseases of the Eye. A Handbook of Ophthalmic Practice. 
 
 By G. E. DE ScHWEiNiTZ, M.D., Professor of Ophthalmology in the 
 Jefferson Medical College, Philadelphia, etc. Handsome royal octavo 
 volume of 696 pages, with 256 fine illustrations and 2 chromo-litho- 
 graphic plates. Cloth, ^4.00 net ; Sheep or Half Morocco, ^5.00 net. 
 
 " A clearly written, comprehensive manual. One which we can commend to students 
 as a reliable text-book, written with an evident knowledge of the wants of those entering 
 upon the study of this special branch of medical science." — British Medical Journal. 
 
 " A work that will meet the requirements not only of the specialist, but of the general 
 practitioner in a rare degree. I am satisfied that unusual success awaits it." — WiLLlAM 
 Pepper, M.D., Projessor of the Theory atid Practice of Medicine and Clinical Medicine, 
 University of Pennsylvania. 
 
 DORLAND'S DICTIONARY. Second Edition, Revised. 
 
 The American Pocket Medical Dictionary. Containing the Pro- 
 nunciation and Definition of all the principal words and phrases, and a 
 large number of useful tables. Edited by W. A. Newman Borland, 
 M. D., Assistant Demonstrator of Obstetrics, University of Pennsylvania; 
 Fellow of the American Academy of Medicine. 518 pages ; handsomely 
 bound in full leather, limp, with gilt edges and patent index. Price, 
 ^i.oo net; with thumb index, $1.25 net. 
 
 DORLAND'S OBSTETRICS. 
 
 A Manual of Obstetrics. By W. A. Newman Dorland, M.D., 
 Assistant Demonstrator of Obstetrics, University of Pennsylvania; 
 Instructor in Gynecology in the Philadelphia Polyclinic. 760 pages; 
 163 illustrations in the text, and 6 full-page plates. Cloth, $2.50 net. 
 
 " By far the best book on this subject that has ever come to our notice." — American 
 Medical Review. 
 
 " It has rarely lieen our duty to review a book which has given us more pleasure in its 
 perusal and more satisfaction in its criticism. It is a veritable encyclopedia of knowledge, 
 a gold mine of practical, concise thoughts." — American Medico-Surgical Bulletin. 
 
Medical Publications of W. B. Saunders. 11 
 
 FROTHINQHAM'S GUIDE FOR THE BACTERIOLOGIST. 
 
 Laboratory Guide for the Bacteriologist. By Langdon Froth- 
 INGHAM, M.D.V., Assistant in Bacteriology and Veterinary Science, 
 Sheffield Scientific School, Yale University. Illustrated. Cloth, 75 cts. 
 
 " It is a convenient and useful little work, and will more than repay the outlay neces- 
 sary for its purchase in the saving of time which would otherwise be consumed in looking 
 up the various points of technique so clearly and concisely laid down in its pages." — Ameri- 
 can Medico- Surgical Bulletin. 
 
 GARRIGUES' DISEASES OF WOMEN. Second Edition, Revised. 
 Diseases of Women. By Henry J. Garrigues, A.M., M.D., Pro- 
 fessor of Gynecology in the New York School of Clinical Medicine ; 
 Gynecologist to St. Mark's Hospital and to the German Dispensary, 
 New York City, etc. Handsome octavo volume of 728 pages, illus- 
 trated by 335 engravings and colored plates. Cloth, $4.00 net; 
 Sheep or Half Morocco, $5.00 net. 
 
 " One of the best text-books for students and practitioners which has been published in 
 the English language ; it is condensed, clear, and comprehensive. The profound learning 
 and great clinical experience of the distinguished author find expression in this book in a 
 most attractive and instructive form. Young practitioners to whom experienced consultants 
 may not be available will find in this book invaluable counsel and help." — Thad. A. 
 Reamy, M.D., LL.D., Professor of Clinical Gynecology, Medical College of Ohio. 
 
 QLEASON'S DISEASES OF THE EAR. Second Edition, Revised. 
 Essentials of Diseases of the Ear. By E. B. Gleason, S.B., 
 M.D., Clinical Professor of Otology, Medico-Chirurgical College, 
 Philadelphia ; Surgeon-in-Charge of the Nose, Throat, and Ear Depart- 
 ment of the Northern Dispensary, Philadelphia. 208 pages, with 
 1 14 illustrations. Cloth, ^i. 00; interleaved for notes, 1 1.25. 
 [See Saunders' Question- Compends, page 21.] 
 
 " It is just the book to put into the hands of a student, and cannot fail to give him a 
 useful introduction to ear-affections ; while the style of question and answer which is adopted 
 throughout the book is, we believe, the best method of impressing facts permanently on the 
 mind. " — Liverpool Medico- Chirurgical fournal. 
 
 GOULD AND PYLE'S CURIOSITIES OF MEDICINE. 
 
 Anomalies and Curiosities of Medicine. By George M. Gould, 
 M.D., and Walter L. Pyle, M.D. An encyclopedic collection of 
 rare and extraordinary cases and of the most striking instances of 
 abnormality in all branches of Medicine and Surgery, derived from an 
 exhaustive research of medical literature from its origin to the present 
 day, abstracted, classified, annotated, and indexed. Handsome im- 
 perial octavo volume of 968 pages, with 295 engravings in the text, 
 and 12 full-page plates. Cloth, $6.00 net; Half Morocco, ^7.00 net. 
 Sold by Subscription. 
 
 " One of the most valuable contributions ever made to medical literature. It is, so far 
 as we know, absolutely unique, and every page is as fascinating as a novel. Not alone for 
 the medical profession has this volume value: it will serve as a book of reference for all who 
 are interested in general scientific, sociologic, or medico-legal topics." — Brooklyn Medical 
 Jou7'nal. 
 
 "This is certainly a most remarkable and interesting volume. It stands alone among 
 medical literature, an anomaly on anomalies, in that there is nothing like it elsewhere in 
 medical literature. It is a book full of revelations from its first to its last page, and cannot 
 but interest and sometimes almost horrify its readers." — American Medico- Surgical Bulletin. 
 
12 Medical Publications of W. B. Saunders. 
 
 GRAFSTROM'S MECHANO=THERAPY. 
 
 A Text=Book of Mechano=Therapy (^Massage and Medical Qym= 
 nasties). By Axel V. Grafstrom, B. Sc, M. D., late Lieutenant in 
 the Royal Swedish Army ; late House Physician City Hospital, Black- 
 well's Island, New York. i2mo, 139 pages, illustrated. Cloth, ^i. 00 net. 
 
 GRIFFITH ON THE BABY. Second Edition, Revised. 
 
 The Care of the Baby. By J. P. Crozer Griffith, M.D., Clini- 
 cal Professor of Diseases of Children, University of Pennsylvania; 
 Physician to the Children's Hospital, Philadelphia, etc. 121110, 404 
 pages, with 67 illustrations in the text, and 5 plates. Cloth, ^1.50. 
 
 " The best book for the use of the young mother with which we are acquainted. . . . 
 There are very few general practitioners who could not read the book through with advan- 
 tage. ' ' — Archives of Pediatrics. 
 
 "The whole book is characterized by rare good sense, and is evidently written by a 
 master hand. It can be read with benefit not only by mothers but by medical students and 
 by any practitioners who have not had large opportunities for observing children." — Ameri- 
 can Jonr?ial of Obstetrics. 
 
 GRIFFITH'S WEIGHT CHART. 
 
 Infant's Weight Chart. Designed by J. P. Crozer Griffith, M.D., 
 Clinical Professor of Diseases of Children in the University of Penn- 
 sylvania, etc. 25 charts in each pad. Per pad, 50 cents net. 
 
 A convenient blank for keeping a record of the child's weight during the first two years 
 of life. Printed on each chait is a curve representing the average weight of a healthy infant, 
 so that any deviation from the normal can readily be detected. 
 
 GROSS, SAMUEL D., AUTOBIOGRAPHY OF. 
 
 Autobiography of Samuel D. Gross, M.D., Emeritus Professor of 
 Surgery in the Jefferson Medical College, Philadelphia, with Remi- 
 niscences of His Times and Contemporaries. Edited by his Sons, 
 Samuel W. Gross, M.D., LL.D., late Professor of Principles of Sur- 
 gery and of Clinical Surgery in the Jefferson Medical College, and 
 A. Haller Gross, A.M., of the Philadelphia Bar. Preceded by a 
 Memoir of Dr. Gross, by the late Austin Flint, M.D., LL.D. In 
 two handsome volumes, each containing over 400 pages, demy octavo, 
 extra cloth, gilt tops, with fine Frontispiece engraved on steel. Price 
 per volume, $2.50 net. 
 
 '• Dr. Gross was perhaps the most eminent exponent of medical science that America 
 has yet produced. His Autobiography, related as it is with a fulness and completeness 
 seldom to be found in such works, is an interesting and valuable book. He comments on 
 many things, especially, of course, on medical men and medical practice, in a very interest- 
 ing way." — The Spectator, London, England. 
 
 HAMPTON'S NURSING. Second Edition, Revised and Enlarged. 
 Nursing: Its Principles and Practice. By Isabel Adams Hamp- 
 ton, Graduate of the New York Training School for Nurses attached 
 to Bellevue Hospital ; late Superintendent of Nurses and Principal of 
 the Training School for Nurses, Johns Hopkins Hospital, Baltimore, 
 Md. 12 mo, 512 pages, illustrated. Cloth, $2.00 net. 
 
 " Seldom have we perused a book upon the subject that has given us so mucli jileasure 
 as the one before us. We would strongly urge upon the members of our own profession the 
 need of a book like (his, for it will enable each of us to become a training school in him- 
 self." — Ontario Medical Journal. 
 
Medical Publications of W, B. Saunders. 13 
 
 HARE'S PHYSIOLOGY. Fourth Edition, Revised. 
 
 Essentials of Piiysiology. By H. A. Hare, M.D., Professor of 
 Therapeutics and Materia Medica in the Jefferson Medical College of 
 Philadelphia. Crown octavo, 239 pages. Cloth, ^i.oo net; inter- 
 leaved for notes, I1.25 net. 
 
 [See Saunders^ Question- Compends, page 21.] 
 
 "The best condensation of physiological knowledge we have yet seen." — Medical 
 Record, New York. 
 
 HART'S DIET IN SICKNESS AND IN HEALTH. 
 
 Diet in Sickness and in Health. By Mrs. Ernest Hart, formerly 
 Student of the Faculty of Medicine of Paris and of the London School 
 of Medicine for Women ; with an Introduction by Sir Henry 
 Thompson, F.R.C.S., M.D., London. 220 pages. Cloth, ^1.50. 
 
 " We recommend it cordially to the attention of all practitioners ; both to them and to 
 their patients it may be of the greatest service." — New York Medical Journal. 
 
 HAYNES' ANATOMY. 
 
 A Manual of Anatomy. By Irving S. Haynes, M.D., Adjunct 
 Professor of Anatomy and Demonstrator of Anatomy, Medical Depart- 
 ment of the New York University, etc. 680 pages, illustrated with 42 
 diagrams in the text, and 134 full-page half-tone illustrations from 
 original photographs of the author's dissections. Cloth, ^2.50 net. 
 
 " This book is the work of a practical instructor — one who knows by experience the 
 requirements of the average student, and is able to meet these requirements in a very satis- 
 factory way. The book is one that can be commended." — Medical Record, New York. 
 
 HEISLER'S EMBRYOLOGY. 
 
 A Text=Book of Embryology. By John C. Heisler, M.D., Pro- 
 fessor of Anatomy in the Medico- Chirurgical College, Philadelphia. Oc- 
 tavo volume of 405 pages, handsomely illustrated. Cloth, ^2.50 net. 
 
 HIRST'S OBSTETRICS. 
 
 A Text=Book of Obstetrics. By Barton Cooke Hirst, M. D., 
 Professor of Obstetrics in the University of Pennsylvania. Handsome 
 octavo volume of 848 pages, with 618 illustrations, and 7 colored 
 plates. Cloth, ^5.00 net; Sheep or Half Morocco, ^6.00 net. 
 
 " The illustrations are numerous and are works of art, many of them appearing for the 
 first time. The arrangerhent of the subject-matter, the foot-notes, and index are beyond 
 criticism. As a true model of what a modern text-book on obstetrics should be, we feel 
 justified in affirming that Dr. Hirst's book is without a rival." — New York Medical Record. 
 
 HYDE AND MONTGOMERY ON SYPHILIS AND THE VENEREAL 
 DISEASES. 
 Syphilis and the Venereal Diseases. By James Nevins Hyde, 
 M.D., Professor of Skin and Venereal Diseases, and Frank H. Mont- 
 gomery, M.D., Lecturer on Dermatology and Genito-Urinary Diseases 
 in Rush Medical College, Chicago, 111. 618 pages, profusely illustrated. 
 Cloth, $2.50 net. 
 
 " We can commend this manual to the student as a help to him in his study of venereal 
 diseases. ' ' — Liverpool Medico- Chirurgical Journal. 
 
 "The best student's manual which has appeared on the subject." — St. Louis Medical 
 and Surgical Journal. 
 
14 Medical Publications of W. B. Saunders. 
 
 JACKSON AND GLEASON'S DISEASES OF THE EYE, NOSE, AND 
 THROAT. Second Edition, Revised. 
 Essentials of Refraction and Diseases of the Eye. By Edward 
 Jackson, A.M., M.D., Professor of Diseases of the Eye in the Phila- 
 delphia Polyclinic and College for Graduates in Medicine ; and — 
 Essentials of Diseases of the Nose and Throat. By E. Bald- 
 win Gleason, M.D., Surgeon-in-Charge of the Nose, Throat, and 
 Ear Department of the Northern Dispensary of Philadelphia. Two 
 volumes in one. Crown octavo, 290 pages; 124 illustrations. Cloth, 
 1 1. 00; interleaved for notes, ^1.25. 
 
 [See Saunders' Question- Cojnpends, page 21.] 
 
 " Of great value to the beginner in these branches. The authors are both capable men, 
 and know what a student most needs." — Medical Record, New York. 
 
 KEATINQ'S DICTIONARY. Second Edition, Revised. 
 
 A New Pronouncing Dictionary of Medicine, with Phonetic 
 Pronunciation, Accentuation, Etymology, etc. By John M. 
 Keating, M.D., LL.D., Fellow of the College of Physicians of Phila- 
 delphia ; Vice-President of the American Paediatric Society ; Editor 
 "Cyclopaedia of the Diseases of Children," etc.; and Henry 
 Hamilton, Author of "A New Translation of Virgil's yEneid into 
 English Rhyme," etc.; with the collaboration of J. Chalmers Da- 
 Costa, M.D., and Frederick A. Packard, M.D. With an Appendix 
 containing Tables of Bacilli, Micrococci, Leucomaines, Ptomaines; 
 Drugs and Materials used in Antiseptic Surgery ; Poisons and their 
 Antidotes ; Weights and Measures ; Thermometric Scales ; New 
 Official and Unofficial Drugs, etc. One volume of over 800 pages. 
 Prices, with Denisori's Patent Ready-Reference Index: Cloth, ^5.00 
 net; Sheep or Half Morocco, ^6.00 net; Half Russia, ^6.50 net. 
 Without Patent Index: Cloth, ^4.00 net; Sheep or Half Morocco, 
 $5.00 net. 
 
 " I am much pleased with Keating's Dictionary, and shall take pleasure in recommend- 
 ing it to my classes." — Henry M. Lyman, M.D., Professor of the Principles and Practice 
 of Medicine, Rusk Medical College, Chicago, III. 
 
 " I am convinced that it will be a very valuable adjunct to my study-table, convenient 
 in size and sufficiently full for ordinary use." — C. A. Lindsley, M.D., Professor of the 
 Theory and Practice of Aledicine, Medical Dept. Yale University. 
 
 KEATINQ'S LIFE INSURANCE. 
 
 How to Examine for Life Insurance. By John M. Keating, 
 M. D., Fellow of the College of Physicians of Philadelphia; Vice- 
 President of the American Paediatric Society; Ex- President of the 
 Association of Life Insurance Medical Directors. Royal octavo, 211 
 pages ; with two large half-tone illustrations, and a plate prepared by 
 Dr. McClellan from special dissections ; also, numerous other illustra- 
 tions. Cloth, $2.00 net. 
 
 " This is by far the most useful book which has yet appeared on insurance examination, 
 a subject of growing interest and importance. Not the least valuable portion of the volume 
 is Part II., which consists of instructions issued to their examining physicians by twenty-four 
 representative companies of this country. If for these alone, the book should be at the right 
 hand of every physician interested in this special branch of medical science." — The Medical 
 News. 
 
Medical Pablications of W. B. Saunders. 15 
 
 KEEN ON THE SURGERY OF TYPHOID FEVER. 
 
 The Surgical Complications and Sequels of Typhoid Fever. 
 
 By Wm. W. Keen, M.D., LL.D., Professor of the Principles of Sur- 
 gery and of Clinical Surgery, Jefferson Medical College, Philadelphia; 
 Corresponding Member of the Societe de Chirurgie, Paris ; Honorary 
 Member of the Societe Beige de Chirurgie, etc. Octavo volume of 
 386 pages, illustrated. Cloth, $3.00 net. 
 
 " This is probably the first and only work in the English language that gives the reader 
 a clear view of what typhoid fever really is, and what it does and can do to the human 
 organism. This book should be in the possession of every medical man in America." — 
 American Medico-Surgical Bulletin. 
 
 KEEN'S OPERATION BLANK. Second Edition, Revised Form. 
 An Operation Blank, with Lists of Instruments, etc. Required 
 in Various Operations. Prepared by W. W. Keen, M.D., LL.D., 
 Professor of the Principles of Surgery in Jefferson Medical College, 
 Philadelphia. Price per pad, containing blanks for fifty operations, 
 50 cents net. 
 
 KYLE ON THE NOSE AND THROAT. 
 
 Diseases of the Nose and Throat. By D. Braden Kyle, M.D., 
 Clinical Professor of Laryngology and Rhinology, Jefferson Medical 
 College, Philadelphia ; Consulting Laryngologist, Rhinologist, and 
 Otologist, St. Agnes' Hospital. Handsome octavo volume of about 
 630 pages, with over 150 illustrations and 6 lithographic plates. Price, 
 Cloth; ^4.00 net ; Half Morocco, ^5.00 net. 
 
 LAINE'S TEMPERATURE CHART. 
 
 Temperature Chart. Prepared by D. T. Laine, M.D. Size 8 x 13;^ 
 inches. A conveniently arranged Chart for recording Temperature, 
 with columns for daily amounts of Urinary and Fecal Excretions, 
 Food, Remarks, etc. On the back of each chart is given in full the 
 method of Brand in the treatment of Typhoid Fever. Price, per pad 
 of 25 charts, 50 cents net. 
 
 " To the busy practitioner this chart will be found of great value in fever cases, and 
 especially for cases of typhoid." — Indian Lancet, Calcutta. 
 
 LOCKWOOD'S practice of MEDICINE. 
 
 A Manual of the Practice of Medicine. By George Roe Lock- 
 wood, M.D., Professor of Practice in the Woman's Medical College 
 of the New York Infirmary, etc. 935 pages, with 75 illustrations in 
 the text, and 22 full-page plates. Cloth, ^2.50 net. 
 
 " Gives in a most concise manner the points essential to treatment usually enumerated 
 in the most elaborate works." — Massachusetts Medical Journal. 
 
 LONG'S SYLLABUS OF GYNECOLOGY. 
 
 A Syllabus of Gynecology, arranged in Conformity with " An 
 American Text=Book of Gynecology." By J. W. Long, M.D., 
 Professor of Diseases of Women and Children, Medical College of 
 Virginia, etc. Cloth, interleaved, $1.00 net. 
 
 " The book is certainly an admirable resume of what every gynecological student and 
 practitioner should know, and will prove of value not only to those who have the ' American 
 Text-Book of Gynecology,' but to others as well." — Brooklyn Medical Journal, 
 
16 Medical Publications of W. B. Saunders. 
 
 MACDONALD'S SURGICAL DIAGNOSIS \ND TREATMENT. 
 
 Surgical Diagnosis and Treatment. By J. W. Macdonald, M.D. 
 Edin., F.R. C.S., Edin., Professor of the Practice of Surgery and of 
 Clinical Surgery in Hamline University ; Visiting Surgeon to St. 
 Barnabas' Hospital, Minneapolis, etc. Handsome octavo volume of 
 800 pages, profusely illustrated. Cloth, $5.00 net; Half Morocco, 
 |6.oo net. 
 
 " A thorough and complete work on surgical diagnosis and treatment, free from pad- 
 ding, full of valuable material, and in accord with the surgical teaching of the day." — T/te 
 Medical News, New York. 
 
 " The work is brimful of just the kind of -jractical information that is useful alike to 
 students and practitioners. It is a pleasure to commend the bock because of its intrinsic 
 value to the medical practitioner." — Cincimiafi Laticet- Clinic 
 
 MALLORY AND WRIGHT'S PATHOLOGICAL TECHNIQUE. 
 
 Pathological Technique. A Practical Manual for Laboratory Work 
 in Pathology, Bacteriology, and JMorbid Anatomy, with chapters on 
 Post-Mortem Technique and the Performance of Autopsies. By Frank 
 B. ]SLa.llory, A.]\L, M.D., Assistant Professor of Patholof}^ Harvarn 
 University Medical School, Boston; and James H. Wright, A.M., 
 M.D., Instructor in Pathology, Harvard University jSIedical School, 
 Boston. Octavo volume of 396 pages, handsomely illustrated. Cloth, 
 $2.50 net. 
 
 " I have been looking forward to the publication of this book, and I am glad to say that 
 I find it to be a most useful laboratory and post-mortem guide, full of practical information, 
 and well up to date." — William H. Welch, Professor of Pathology, Johns Hopkins Uni- 
 versity, Baltimore, Md. 
 
 MARTIN'S MINOR SURGERY, BANDAGING, AND VENEREAL 
 
 DISEASES. Second Edition, Revised. 
 Essentials of Minor Surgery, Bandaging, and Venereal 
 Diseases. By Edward Martin, A.M., M.D., Clinical Professor of 
 Genito-Urinary Diseases, University of Pennsylvania, etc. Crown 
 octavo, 166 pages, with 78 illustrations. Cloth, $1.00; interleaved for 
 notes, §1.25. 
 
 [See Saunders' Question- Compends, page 21.] 
 
 "A very practical and systematic study of the subjects, and shows the author's famil- 
 iarity with the needs of students." — Therapeutic Gazette. 
 
 MARTIN'S SURGERY. Sixth Edition, Revised. 
 
 Essentials of Surgery. Containing also Venereal Diseases, Surgi- 
 cal Landmarks, Minor and Operative Surgery, and a complete de- 
 scription, with illustrations, of the Handkerchief and Roller Bandages. 
 By Edward Martin, A.M., M.D., Clinical Professor of Genito- 
 Urinary Diseases, University of Pennsylvania, etc. Crown octavo, 338 
 pages, illustrated. With an Appendix containing full directions for the 
 preparation of the materials used in Antiseptic Surgery, etc. Cloth, 
 $1.00; interleaved for notes, $1.25. 
 
 [See Saunders' Question- Compends, page 21.] 
 
 " Contains all necessary essentials of modem surgery in a comparatively small space. 
 Its style is interesting, and its illustrations are admirable." — Medical and Surgical Reporter. 
 
Medical Publications of W. B. Saunders. 17 
 
 McFARLAND'S PATHOGENIC BACTERIA. Second Edition, Re= 
 vised and Greatly Enlarged. 
 Text=Book upon the Pathogenic Bacteria. By Joseph McFar- 
 LAND, M. D., Professor of Pathology and Bacteriology in the Medico- 
 Chirurgical College of Philadelphia, etc. Octavo volume of 497 pages, 
 finely illustrated. Cloth, $2.50 net. 
 
 " Dr. McFarland has treated the subject in a systematic manner, and has succeeded in 
 presenting in a concise and readable form the essentials of bacteriology up to date. Alto- 
 gether, the book is a satisfactory one, and I shall take pleasure in recommending it to the 
 students of Trinity College." — H. B. Anderson, M.D. , Professor of Pathology and Bac- 
 teriology, Trinity Medical College, Toronto. 
 
 MEIGS ON FEEDING IN INFANCY. 
 
 Feeding in Early Infancy. By Arthur V. Meigs, M.D. Bound 
 in limp cloth, flush edges, 25 cents net. 
 
 "This pamphlet is worth many times over its price to the physician. The author's 
 experimenis and conclusions are original, and have been the means of doing much good." — 
 Medical Bulletin. 
 
 MOORE'S ORTHOPEDIC SURGERY. 
 
 A Manual of Orthopedic Surgery. By James E. Moore, M.D., 
 Professor of Orthopedics and Adjunct Professor of Clinical Surgery, 
 University of Minnesota, College of Medicine and Surgery. Octavo 
 volume of 356 pages, handsomely illustrated. Cloth, ^2.50 net. 
 
 " A most attractive work. The illustrations and the care with which the book is adapted 
 to the wants of the general practitioner and the student are worthy of great praise." — Chicago 
 Medical Recorder. 
 
 "A very demonstrative work, every illustration of which conveys a lesson. The work is 
 a most excellent and commendable one, which we can certainly endorse with pleasure." — 
 St. Louis Medical and Surgical Journal. 
 
 MORRIS'S MATERIA MEDICA AND THERAPEUTICS. Fifth 
 Edition, Revised. 
 Essentials of Materia Medica, Therapeutics, and Prescription= 
 Writing. By Henry Morris, M.D., late Demonstrator of Thera- 
 peutics, Jefferson Medical College, Philadelphia ; Fellow of the College 
 of Physicians, Philadelphia, etc. Crown octavo, 288 pages. Cloth, 
 ^i.oo; interleaved for notes, $1.25. 
 
 [See Saunders^ Question- Cojnpends , page 21.] 
 
 " This work, already excellent in the old edition, has been largely improved by revi- 
 sion. " — American Practitioner and News. 
 
 MORRIS, WOLFF, AND POWELL'S PRACTICE OF MEDICINE. 
 Third Edition, Revised. 
 Essentials of the Practice of Medicine. By Henry Morris, M.D., 
 late Demonstrator of Therapeutics, Jefferson Medical College, Phila- 
 delphia ; with an Appendix on the Clinical and Microscopic Examina- 
 tion of Urine, by Lawrence Wolff, M.D. , Demonstrator of Chemistry, 
 Jefferson Medical College, Philadelphia. Enlarged by some 300 essen- 
 tial formulae collected and arranged by William M. Powell, M.D. 
 Post-octavo, 488 pages. Cloth, ^2.00. 
 
 [See Saunders^ Question- Compends, page 21.] 
 
 " The teaching is sound, the presentation graphic ; matter full as can be desired, and 
 style attractive." — A?nerican Practitioner and News. 
 
18 Medical Publications of W. B. Saunders. 
 
 MORTEN'S NURSE'S DICTIONARY. 
 
 Nurse's Dictionary of Medical Terms and Nursing Treat- 
 ment. Containing Definitions of the Principal Medical and Nursing 
 Terms and Abbreviations ; of the Instruments, Drugs, Diseases, Acci- 
 dents, Treatments, Operations, Foods, Appliances, etc. encountered 
 in the ward or in the sick-room. By Honnor Morten, author of 
 " How to Become a Nurse," etc. i6mo, 140 pages. Cloth, ^i.oo. 
 
 " A handy, compact little volume, containing a large amount of general information, all 
 of which is arranged in dictionary or encyclopedic form, thus facilitating quick reference. 
 It is certainly of value to those for whose use it is published." — Chicago Clinical Review. 
 
 NANCREDE'S ANATOMY. Sixth Edition, Thoroughly Revised. 
 Essentials of Anatomy, including the Anatomy of the Viscera. 
 By Charles B. Nancrede, M.D., LL.D., Professor of Surgery and 
 of Clinical Surgery in the University of Michigan, Ann Arbor. Crown 
 octavo, 420 pages; 151 illustrations. Based upon Gj'ay's Anatomy. 
 Cloth, $1.00 net; interleaved for notes, $1.25 net. 
 
 [See Smitiders' Question- Compends, page 21.] 
 
 " For self-quizzing and keeping fresh in mind the knowledge of anatomy gained at 
 school, it would not be easy to speak of it in terms too favorable." — American Practitioner. 
 
 NANCREDE'S ANATOMY AND DISSECTION. Fourth Edition. 
 Essentials of Anatomy and Manual of Practical Dissection. 
 
 By Charles B. Nancrede, M.D., LL.D., Professor of Surgery and of 
 Clinical Surgery, University of Michigan, Ann Arbor, Post-octavo ; 
 500 pages, with full-page lithographic plates in colors, and nearly 200 
 illustrations. Extra Cloth (or Oilcloth for dissection-room), $2.00 net. 
 
 " It may in many respects be considered an epitome of Gray's popular work on general 
 anatomy, at tlie same time having some distinguishing characteristics of its own to commend 
 it. The plates are of more than ordinary excellence, and are of especial value to students 
 in their work in the dissecting room." — Journal of the American ]\Iedical Association. 
 
 NORRIS'S SYLLABUS OF OBSTETRICS. Third Edition, Revised. 
 Syllabus of Obstetrical Lectures in the Medical Department 
 of the University of Pennsylvania. By Richard C. Norris, 
 A.M., M.D., Detnonstrator of Obstetrics, University of Pennsylvania. 
 Crown octavo, 222 pages. Cloth, interleaved for notes, $2.00 net. 
 
 "This work is so far superior to others on the same subject that we take pleasure in 
 calling attention briefly to its excellent features. It covers the subject thoroughly, and will 
 prove invaluable both to the student and the practitioner." — Medical Record, New York. 
 
 PENROSE'S DISEASES OF WOMEN. Second Edition, Revised. 
 A Text=Book of Diseases of Women. By Charles B. Penrose, 
 M.D., Ph.D., Professor of Gynecology in the University of Pennsyl- 
 vania; Surgeon to the Gynecean Hospital, Philadelphia. Octavo 
 volume of 529 pages, handsomely illustrated. Cloth, $3.50 net. 
 
 *< I shall value very highly the copy of Penrose's ' Di.seases of Women' received. 
 I have already recommended it to my class as THE BEST book."— Howard A. Kelly, 
 Professor of Gynecology and Obstetrics, Johns Hopkins University, Baltimore, Md. 
 
 " The book is to be commended without reserve, not only to the student but to the 
 general practitioner who wishes to have the latest and best modes of treatment explained 
 with absolute clearness." — Therapeutic Gazette. 
 
Medical Publications of W. B. Saunders. 19 
 
 POWELL'S DISEASES OF CHILDREN. Second Edition. 
 
 Essentials of Diseases of Children. By William M. Powell, 
 M.D., Attending Physician to the Mercer House for Invalid Women 
 at Atlantic City, N. J. ; late Physician to the Clinic for the Diseases of 
 Children in the Hospital of the University of Pennsylvania. Crown 
 octavo, 222 pages. Cloth, ^i.oo; interleaved for notes, ^1.25. 
 
 [See Saunders' Question- Compends, page 21.] 
 
 " Contains the gist of all the best works in the department to which it relates." — 
 American Practitioner and Netvs. 
 
 PRINQLE'S SKIN DISEASES AND SYPHILITIC AFFECTIONS. 
 Pictorial Atlas of Skin Diseases and Syphilitic Affections 
 (American Edition). Translation from the French. Edited by 
 J. J. Pringle, M.B., F.R.C.P., Assistant Physician to the Middlesex 
 Hospital, London. Photo-lithochromes from the famous models in 
 the Museum of the Saint-Louis Hospital, Paris, with explanatory wood- 
 cuts and text. In 12 Parts. Price per Part, $3.00. Complete in 
 one volume, Half Morocco binding, ^40.00 net. 
 
 "I strongly recommend this Atlas. The plates are exceedingly well executed, and 
 will be of great value to all studying dermatology." — Stephen Mackenzie, M.D. 
 
 "The introduction of explanatory wood-cuts in the text is a novel and most important 
 feature which greatly furthers the easier understanding of the excellent plates, than which 
 nothing, we venture to say, has been seen better in point of correctness, beauty, and general 
 merit." — New York Medical Jourtial. 
 
 PRYOR— PELVIC INFLAMMATIONS. 
 
 The Treatment of Pelvic Inflammations through the Vagina. 
 
 By W. R. Pryor, M.D., Professor of Gynecology in New York Poly- 
 clinic. i2mo, 248 pages, handsomely illustrated. Cloth, ^2.00 net. 
 
 "This subject, which has recently been so thoroughly canvassed in high gynecological 
 circles, is made available in this volume to the general practitioner and student. Nothing is 
 too minute for mention and nothing is taken for granted ; consequently the book is of the utmost 
 value. The illustrations and the technique are beyond criticism." — Chicago Medical Recorder. 
 
 PYE'S BANDAGING. 
 
 Elementary Bandaging and Surgical Dressing. With Direc- 
 tions concerning the Immediate Treatment of Cases of Emergency. 
 For the use of Dressers and Nurses. By Walter Pye, F.R.C.S., late 
 Surgeon to St. Mary's Hospital, London. Small 121110, with over 80 
 illustrations. Cloth, flexible covers, 75 cents net. 
 
 "The directions are clear and the illustrations are good." — London Lancet. 
 " The author writes well, the diagrams are clear, and the book itself is small and port- 
 able, although the paper and type are good." — British Medical Journal. 
 
 RAYMOND'S PHYSIOLOGY. 
 
 A Manual of Physiology. By Joseph H. Raymond, A.M., M.D., 
 Professor of Physiology and Hygiene and Lecturer on Gynecology in 
 the Long Island College Hospital ; Director of Physiology in the 
 Hoagland Laboratory, etc. 382 pages, with 102 illustrations in the 
 text, and 4 full -page colored plates. Cloth, $1.25 net. 
 
 " Extremely well gotten up, and the illustrations have been selected with care. The 
 text is fully abreast with modern physiology." — British Medical Journal. 
 
Saunders' 
 Question 
 compends 
 
 Arranged in Question and 
 Answer Form. 
 
 npHE MOST COMPLETE AND BEST 
 ILLUSTRATED SERIES OF 
 
 COMPENDS EVER ISSUED. 
 
 Now the Standard Authorities in Medical Literature .... 
 
 with Students and Practitioners in every City of the United States and Canada. 
 
 O-- 
 
 OVER 175,000 COPIES SOLD. ^ 
 
 •<<3 
 
 THE REASON WHY. 
 
 They are the advance guard of "Student's Helps" — that DO help. They are the 
 leaders in their special line, well and authoritatively written by able men, who, as teachers in 
 the large colleges, know exactly what is wanted by a student preparing for his examinations. 
 The'judgment exercised in the selection of authors is fully demonstrated by their professional 
 standing. Chosen from the ranks of Demonstrators, Quiz-masters, and Assistants, most of 
 them have become Professors and Lecturers in their respective colleges. 
 
 Each book is of convenient size (5x7 inches), containing on an average 250 pages, 
 profusely illustrated, and elegantly printed in clear, readable type, on fine paper. 
 
 The entire series, numbering twenty-three volumes, has been kept thoroughly revised 
 and enlarged when necessary, many of the books being in their fifth and sixth editions. 
 
 TO SUM UP. 
 
 Although there are numerous other Quizzes, Manuals, Aids, etc. in the market, none of 
 them approach the "Blue Series of Question Compends;" and the claim is made for the 
 following points of excellence : 
 
 1. Professional distinction and reputation of i^uthors. 
 
 2. Conciseness, clearness, and soundness of treatment. 
 
 3. Quality of illustrations, paper, printing, and binding. 
 
 Any cf these Compends will be mailed on receipt of price (see next page for List). 
 
oaunders^ Question-Compend Series^ 
 
 Price, Cloth, $J.OO per copy, except when otherwise noted. 
 
 "Where the work of preparing students' manuals is to end we cannot say, but the 
 Saunders Series, in our opinion, bears off the palm at present."— iWw York Medical Record. 
 
 1. ESSENTIALS OF PHYSIOLOGY. By H. A. Hare, M.D. Fourth edition, 
 
 revised and enlarged. (^I.oo net. ) 
 
 2. ESSENTIALS OF SURGERY. By Edward Martin, M.D. Sixth edition, 
 
 revised, with an Appendix on Antiseptic Surgery. 
 
 3. ESSENTIALS OF ANATOMY. By Charles B. Nancrede, M.D. Sixth 
 
 edition, thoroughly revised and enlarged, (^i.oo net.) 
 
 4. ESSENTIALS OF MEDICAL CHEMISTRY, ORGANIC AND INORGANIC. 
 
 By Lawrence Wolff, M.D. Fifth edition, revised, (^i.oo net.) 
 
 5. ESSENTIALS OF OBSTETRICS. By W. Easterly Ashton, M.D. Fourth 
 
 edition, revised and enlarged. 
 
 6. ESSENTIALS OF PATHOLOGY AND MORBID ANATOMY. By C. E. 
 
 Armand Semple, M.D. 
 
 7. ESSENTIALS OF MATERIA MEDICA, THERAPEUTICS, AND PRE- 
 
 SCRIPTION=WRITING. By Henry Morris, M.D. Fifth edition, revised. 
 
 8. 9. ESSENTIALS OF PRACTICE OF MEDICINE. By Henry Morris, 
 
 M.D. An Appendix on Urine Examination. By Lawrence Wolff, M.D. 
 Third edition, enlarged by some 300 Essential Formulae, selected from eminent 
 authorities, by Wm. M. Powell, M.D. (Double number, ^2.00.) 
 
 10. ESSENTIALS OF QYN/ECOLOQY. By Edwin B. Cragin, M.D. Fourth 
 edition, revised. 
 
 1 \ . ESSENTIALS OF DISEASES OF THE SKIN. By Henry W. Stelwagon, 
 M.D. Fourth edition, revised and enlarged, (^i.oo net.) 
 
 12. ESSENTIALS OF MINOR SURGERY, BANDAGiNG, AND VENEREAL 
 
 DISEASES. By Edward Martin, M.D. Second ed. , revised and enlarged. 
 
 13. ESSENTIALS OF LEGAL MEDICINE, TOXICOLOGY, AND HYGIENE. 
 
 By C. E. Armand Semple, M.D. 
 
 14. ESSENTIALS OF DISEASES OF THE EYE, NOSE, AND THROAT. 
 
 By Edward Jackson, M.D., and E. B. Gleason, M.D. Second ed., revised. 
 
 15. ESSENTIALS OF DISEASES OF CHILDREN. By William M. Powell, 
 
 M.D. Second edition. 
 
 16. ESSENTIALS OF EXAMINATION OF URINE. By Lawrence Wolff, 
 
 M.D. Colored " Vogel Scale." (75 cents.) 
 
 17. ESSENTIALS OF DIAGNOSIS. By S. Solis Cohen, M.D., and A. A. Eshner, 
 
 M.D. (|i.5onet.) 
 
 18. ESSENTIALS OF PRACTICE OF PHARMACY. By Lucius E. Sayre. 
 
 Second edition, revised and enlarged. 
 
 20. ESSENTIALS OF BACTERIOLOGY. By M. V. Ball, M.D. Third edition, 
 
 revised. 
 
 21. ESSENTIALS OF NERVOUS DISEASES AND INSANITY. By John C. 
 
 Shaw-, M.D. Third edition, revised. 
 
 22. ESSENTIALS OF MEDICAL PHYSICS. By Fred J. Brockway, M.D. 
 
 Second edition, revised. ($1.00 net.) 
 
 23. ESSENTIALS OF MEDICAL ELECTRICITY. By David D. Stewart, M.D., 
 
 and Edward S. Lawrance, M.D. 
 
 24. ESSENTIALS OF DISEASES OF THE EAR. By E. B. Gleason, M.D. 
 
 Second edition, revised and greatly enlarged. 
 
 Pamphlet containing specimen pages, etc. sent free upon application* 
 
Saunders* re... 
 
 tor jtudents 
 
 New Series and 
 
 of Manuals Practitioners. 
 
 ' I 'HAT there exists a need for thoroughly reliable hand-books on the leading branches 
 of Medicine and Surgery is a fact amply demonstrated by the favor with -which 
 the SAUNDERS NE'W SERIES OF MANUALS have been received by medical 
 students and practitioners and by the Medical Press. These manuals are not merely 
 condensations from present literature, but are ably written by well-known authors 
 and practitioners, most of them being teachers in representative American colleges. 
 Each volume is concisely and authoritatively w^ritten and exhaustive in detail, without 
 being encumbered w^ith the introduction of "cases," which so largely expand the 
 ordinary text-book. These manuals will therefore form an admirable collection of 
 advanced lectures, useful alike to the medical student and the practitioner: to the 
 latter, too busy to search through page after page of elaborate treatises for what he 
 wants to know^, they w^ill prove of inestimable value ; to the former they will afford 
 safe guides to the essential points of study. 
 
 The SAUNDERS NEW SERIES OF MANUALS are conceded to be superior 
 to any similar books now^ on the market. No other manuals afford so much infor- 
 mation in such a concise and available form. A liberal expenditure has enabled the 
 publisher to render the mechanical portion of the w^ork worthy of the high literary 
 standard attained by these books. 
 
 Any of these Manuals w^ill be mailed on receipt of price (see next page for List). 
 
Saunders^ New Series of Manuals* 
 
 VOLUMES PUBLISHED. 
 
 PHYSIOLOGY. By Joseph Howard Raymond, A.M., M.D., Professor of Physiology 
 and Hygiene and Lecturer on Gynecology in the Long Island College Hospital ; 
 Director of Physiology in the Hoagland Laboratory, etc. Illustrated. Cloth, $1.25 net. 
 
 SURGERY, General and Operative. By John Chalmers DaCosta, M.D., Clini- 
 cal Professor of Surgery, Jefi'erson Medical College, Philadelphia; Surgeon to the 
 Philadelphia Hospital, etc. Second edition, thoroughly revised and greatly enlarged. 
 Octavo, 911 pages, profusely illustrated. Cloth, $4.00 net ; Half Morocco, $5.00 net. 
 
 DOSE=BOOK AND MANUAL OF PRESCRIPTION=WRITING. By E. Q. 
 
 Thornton, M.D., Demonstrator of Therapeutics, Jefferson Medical College, Phila- 
 delphia. Illustrated. Cloth, ^1.25 net. 
 
 SURGICAL ASEPSIS. By Carl Beck, M.D., Surgeon to St. Mark's Hospital and 
 to the New York German Poliklinik, etc. Illustrated. Cloth, ^1.25 net. 
 
 MEDICAL JURISPRUDENCE. By Henry C. Chapman, M.D. Professor of Insti- 
 tutes of Medicine and Medical Jurisprudence in the Jefferson Medical College of Phila- 
 delphia. Illustrated. Cloth, ^1.50 net. 
 
 SYPHILIS AND THE VENEREAL DISEASES. By James Nevins Hyde, M.D., 
 Professor of Skin and Venereal Diseases, and Frank H. Montgomery, M.D., 
 Lecturer on Dermatology and Genito-Urinary Diseases in Rush Medical College, 
 Chicago. Profusely illustrated. Cloth, ^2.50 net. 
 
 PRACTICE OF MEDICINE. By George Roe Lockwood, M.D., Professor of 
 Practice in the Woman's Medical College of the New York Infirmary ; Instructor in 
 Physical Diagnosis in the Medical Department of Columbia College, etc. Illustrated. 
 Cloth, ^2.50 net. 
 
 MANUAL OF ANATOMY. By Irving S. Haynes, M.D., Adjunct Professor of 
 Anatomy and Demonstrator of Anatomy, Medical Department of the New York 
 University, etc. Beautifully illustrated. Cloth, ^2.50 net. 
 
 MANUAL OF OBSTETRICS. By W. A. Newman Dorland, M.D., Assistant 
 Demonstrator of Obstetrics, University of Pennsylvania ; Chief of Gynecological Dis- 
 pensary, Pennsylvania Hospital, etc. Profusely illustrated. Cloth, ^2.50 net. 
 
 DISEASES OF WOMEN. By J. Bland Sutton, F. R. C. S., Assistant Surgeon to 
 Middlesex Hospital and Surgeon to Chelsea Hospital, London; and Arthur E. 
 Giles, M. D., B. Sc. Lond., F.R.C.S. Edin., Assistant Surgeon to Chelsea Hospital, 
 London. Handsomely illustrated. Cloth, ^2.50 net. 
 
 VOLUMES IN PREPARATION. 
 
 NERVOUS DISEASES. By Charles W. Burr, M.D., Clinical Professor of Nervous 
 Diseases, Medico- Chirurgical College, Philadelphia ; Pathologist to the Orthopaedic 
 Hospital and Infirmary for Nervous Diseases ; Visiting Physician to the St. Joseph 
 Hospital, etc. 
 
 *** There will be published in the same series, at short intervals, carefully-prepared works 
 on various subjects by prominent specialists. 
 
 Pamphlet containiiig specimen pages^ etc. sent free upon application. 
 
24 Medical Publications of W, B. Saunders. 
 
 SAUNDBY'S RENAL AND URINARY DISEASES. 
 
 Lectures on Renal and Urinary Diseases. By Robert Saundby, 
 M.D. Edin., Fellow of the Royal College of Physicians, London, and 
 of the Royal Medico-Chirurgical Society ; Physician to the General 
 Hospital ; Consulting Physician to the Eye Hospital and to the Hos- 
 pital for Diseases of Women; Professor of Medicine in Mason College, 
 Birmingham, etc. Octavo volume of 434 pages, with numerous illus- 
 trations and 4 colored plates. Cloth, $2.50 net. 
 
 " The volume makes a favorable impression at once. The style is clear and succinct. 
 "We cannot find any part of the subject in which the views expressed are not carefully thought 
 out and fortified by evidence drawn from the most recent sources. The book may be cordially 
 recommended." — British Medical Journal. 
 
 5AUNDERS' MEDICAL HAND=ATLASES. 
 
 This series of books consists of authorized translations into English of 
 the world-famous Lehmann Medicinische Handatlanten. Each 
 
 volume contains from 50 to 100 colored lithographic plates, besides 
 numerous illustrations in the text. There is a full description of each 
 plate, and each book contains a condensed but adequate outline of the 
 subject to which it is devoted. For full description of this series, with 
 list of volumes and prices, see page 2. 
 
 " Lehmann Medicinische Handatlanten belong to that class of books that are too good 
 to be appropriated by any one nation." — jfournal of Eye, Ear, and Throat Diseases. 
 
 " The appearance of these works marks a new era in illustrated English medical 
 works." — The Canadian Practitioner. 
 
 SAUNDERS' POCKET MEDICAL FORMULARY. Fifth Edition, 
 Revised. 
 
 By William M. Powell, M.D., Attending Physician to the Mercer 
 House for Ihvalid Women at Atlantic City, N. J. Containing 1800 
 formulae selected from the best-known authorities. With an Appen- 
 dix containing Posological Table, Formulae and Doses for Hypo- 
 dermic Medication, Poisons and their Antidotes, Diameters of the 
 Female Pelvis and Fcetal Head, Obstetrical Table, Diet List for Various 
 Diseases, Materials and Drugs used in Antiseptic Surgery, Treatment 
 of Asphyxia from Drowning, Surgical Remembrancer, Tables of 
 Incompatibles, Eruptive Fevers, Weights and Measures, etc. Hand- 
 somely bound in flexible morocco, with side index, wallet, and flap. 
 $1.75 net. 
 
 "This little book, that can be conveniently carried in the pocket, contains an immense 
 amount of material. It is very useful, and, as the name of the author of each prescription 
 is given, is unusually reliable." — Medical Record, New York. 
 
 SAYRE'S PHARMACY. Second Edition, Revised. 
 
 Essentials of the Practice of Pharmacy, By Lucius E. Sayre, 
 M.D., Professor of Pharmacy and Materia Medica in the University of 
 Kansas. Crown octavo, 200 pages. Cloth, ^i.oo; interleaved for 
 notes, $1.25. 
 
 [See Saufiders^ Question- Compends, page 21.] 
 
 "The topics are treated in a simple, practical manner, and the work forms a very useful 
 student's manual." — Boston Medical and Surgical Journal. 
 
Medical Publications of W. B. Saunders. 25 
 
 SEMPLE'S LEGAL MEDICINE, TOXICOLOGY, AND HYGIENE. 
 Essentials of Legal Medicine, Toxicology, and Hygiene. By 
 
 C. E. Armand Semple, B. A., M. B. Cantab., M. R. C. P. Lend., 
 Physician to the Northeastern Hospital for Children, Hackney, etc. 
 Crown octavo, 2 12 pages; 130 illustrations. Cloth, ^i. 00; interleaved 
 for notes, ^1.25. 
 
 [See Saunde7's Question- Coiiipends, page 21.] 
 
 " No general practitioner or student can afford to be without this valuable work. The 
 subjects are dealt with by a masterly hand." — London Hospital Gazette. 
 
 SEMPLE'S PATHOLOGY AND MORBID ANATOMY. 
 
 Essentials of Pathology and Morbid Anatomy. By C. E. 
 
 Armand Semple, B.A., M.B. Cantab., M.R.C.P. Lond., Physician to 
 the Northeastern Hospital for Children, Hackney, etc. Crown octavo, 
 174 pages; illustrated. Cloth, $1.00; interleaved for notes, ^1.25. 
 [See Saunders' Question- Compends, page 21.] 
 
 " Should take its place among the standard volumes on the bookshelf of both student 
 and practitioner." — London Hospital Gazette. 
 
 SENN'S GENITO=URINARY TUBERCULOSIS. 
 
 Tuberculosis of the Genito=Urinary Organs, Male and Female. 
 
 By Nicholas Senn, M.D., Ph.D., LL.D., Professor of the Practice of 
 Surgery and of Clinical Surgery, Rush Medical College, Chicago. 
 Handsome octavo volume of 320 pages, illustrated. Cloth, ^3.00 net. 
 
 " An important book upon an important subject, and written by a man of mature judg- 
 ment and wide experience. The author has given us an instructive book upon one of the 
 most important subjects of the day." — Clinical Reporter. 
 
 " A work which adds another to the many obligations the profession owes the talented 
 author." — Chicago Medical Recorder. 
 
 SENN'S SYLLABUS OF SURGERY. 
 
 A Syllabus of Lectures on the Practice of Surgery, arranged 
 in conformity with " An American Text=Book of Surgery." By 
 
 Nicholas Senn, M.D., Ph.D., Professor of the Practice of Surgery and 
 of Clinical Surgery in Rush Medical College, Chicago. Cloth, ^2.00. 
 
 " This syllabus will be found of service by the teacher as well as the student, the work 
 being superbly done. There is no praise too high for it. No surgeon should be without 
 it." — Nezv York Medical Times. 
 
 SENN'S TUMORS. 
 
 Pathology and Surgical Treatment of Tumors. By N. Senn, 
 
 M.D., Ph.D., LL.D., Professor of Surgery and of Clinical Surgery, 
 Rush Medical College ; Professor of Surgery, Chicago Polyclinic ; 
 Attending Surgeon to Presbyterian Hospital ; Surgeon-in-Chief, St. 
 Joseph's Hospital, Chicago. Octavo volume of 710 pages, with 515 
 engravings, including full-page colored plates. New and Revised Edi- 
 tion in Preparation. 
 
 " The most exhaustive of any recent book in Ergnsh on this subject. It is well illus- 
 trated, and will doubtless remain as the principal monograph on the subject in our language 
 for some years. The book is handsomely illustrated and printed, and the author has given a 
 notable and lasting contribution to surgery." — Journal of the Ame7-ican Medical Association. 
 
26 Medical Publications of W. B. Saunders. 
 
 SHAW'S NERVOUS DISEASES AND INSANITY. Third Edition, 
 Revised. 
 Essentials of Nervous Diseases and Insanity. By John C. 
 Shaw, M.D., Clinical Professor of Diseases of the Mind and Nervous 
 System, Long Island College Hospital Medical School ; Consulting 
 Neurologist to St. Catherine's Hospital and to the Long Island College 
 Hospital. Crown octavo, i86 pages; 48 original illustrations. Cloth, 
 ^i.oo ; interleaved for notes, ^1.25. 
 
 [See Saunders'' Question- Compends, page 21.] 
 
 "Clearly and intelligently written." — Bosto7i Medical attd Surgical Jownal. 
 
 "There is a mass of valuable material crowded into this small compass." — American- 
 Medico- Sta-gical Bulletin. 
 
 STARR'S DIETS FOR INFANTS AND CHILDREN. 
 
 Diets for Infants and Children in Health and in Disease. By 
 
 Louis Starr, M.D., Editor of "An American Text-Book of the 
 Diseases of Children." 230 blanks (pocket-book size), perforated 
 and neatly bound in flexible morocco. ^1.25 net. 
 
 The first series of blanks are prepared for the first seven months of infant life ; each 
 blank indicates the ingredients, but not the quantities, of the food, the latter directions being 
 left for the physician. After the seventh month, modifications being less necessary, the diet 
 lists are printed in full. Formulae for the preparation of diluents and foods are appended. 
 
 STELW AGON'S DISEASES OF THE SKIN. Fourth Ed., Revised. 
 
 Essentials of Diseases of the Skin. By Henry W. Stelwagon, 
 M.D., Clinical Professor of Dermatology in the Jefferson Medical 
 College, Philadelphia ; Dermatologist to the Philadelphia Hospital ; 
 Physician to the Skin Department of the Howard Hospital, etc. 
 Crown octavo, 276 pages; 88 illustrations. Cloth, ^i. 00 net; inter- 
 leaved for notes, $1.25 net. 
 
 [See Saunde7's' Question-Compends, page 21.] 
 
 " The best student's manual on skin diseases we have yet seen." — Times and Register^ 
 
 STENGEL'S PATHOLOGY. Second Edition. 
 
 A Text=Book of Pathology. By Alfred Stengel, M.D., Professor 
 of Clinical Medicine in the University of Pennsylvania; Physician to 
 the Philadelphia Hospital ; Physician to the Children's Hospital, etc. 
 Handsome octavo volume of 848 pages, with nearly 400 illustrations, 
 many of them in colors. Cloth, $4.00 net; Half Morocco, $5.00 
 net. 
 
 STEVENS' MATERIA MEDICA AND THERAPEUTICS. Second 
 Edition, Revised. 
 A Manual of Materia Medica and Therapeutics. By A. A. 
 
 Stevens, A.M., M.D., Lecturer on Terminology and Instructor in 
 Physical Diagnosis in the University of Pennsylvania; Professor of 
 Pathology in the Woman's Medical College of Pennsylvania. Post- 
 octavo, 445 pages. Flexible leather, $2.25. 
 ««The author has faithfully iiresented modern therapeutics in a comprehensive work, 
 and, while intended particularly for the use of students, it will be found a reliable guide and 
 sufficiently comprehensive for the physician in practice." — University Medical Magazitte. 
 
Medical Publications of W. B. Saunders. 27 
 
 STEVENS' PRACTICE OF MEDICINE. Fifth Edition, Revised. 
 A Manual of the Practice of Medicine. By A. A. Stevens, A. M., 
 
 M. D., Lecturer on Terminology and Instructor in Physical Diagnosis 
 in the University of Pennsylvania; Professor of Pathology in the 
 Woman's Medical College of Pennsylvania. Specially intended for 
 students preparing for graduation and hospital examinations. Post- 
 octavo, 519 pages ; illustrated. Flexible leather, ^2.00 net. 
 
 " The frequency with which new editions of this manual are demanded bespeaks its 
 popularity. It is an excellent condensation of the essentials of medical practice for the 
 student, and maybe found also an excellent reminder for the busy physician." — Btiffalo 
 Medical Journal. 
 
 STEWART'S PHYSIOLOGY. Third Edition, Revised. 
 
 A Manual of Physiology, with Practical Exercises. For 
 Students and Practitioners. By G. N. Stewart, M.A., M.D., 
 D.Sc, lately Examiner in Physiology, University of Aberdeen, and 
 of the New Museums, Cambridge University ; Professor of Physiology 
 in the Western Reserve University, Cleveland, Ohio. Octavo volume 
 of 848 pages; 300 illustrations in the text, and 5 colored plates. 
 Cloth, $3.75 net. 
 
 " It will ma,ke its way by sheer force of merit, and amply deserves to do so. It is one 
 of the very best English text-books on the subject." — London Lancet. 
 
 "Of the many text-books of physiology published, we do not know of one that so 
 nearly comes up to the ideal as does Prof. Stewart's volume." — British Medical Journal. 
 
 STEWART AND LAWRANCE'S MEDICAL ELECTRICITY. 
 
 Essentials of Medical Electricity. By D. D. Stewart, M.D., 
 Demonstrator of Diseases of the Nervous System and Chief of the 
 Neurological Clinic in the Jefferson Medical College ; and E. S. 
 Lawrance, M.D., Chief of the Electrical Clinic and Assistant Demon- 
 strator of Diseases of the Nervous System in the Jefferson Medical 
 College, etc. Crown octavo, 158 pages; 65 illustrations. Cloth, 
 ^ 1 . 00 ; interleaved for notes, ^1.25. 
 
 [See Saundei's' Question- Conipends, page 21.] 
 
 •' Throughout the whole brief space at their command the authors show a discriminating 
 knowledge of their subject." — Medical News. 
 
 STONEY'S NURSING. Second Edition, Revised. 
 
 Practical Points in Nursing. For Nurses in Private Practice, 
 
 By Emily A. M. Stoney, Graduate of the Training-School for Nurses, 
 Lawrence, Mass.; late Superintendent of the Training-School for 
 Nurses, Carney Hospital, South Boston, Mass. 456 pages, illustrated 
 with 73 engravings in the text, and 8 colored and half-tone plates. 
 Cloth, $1.75 net. 
 
 " There are few books intended for non-professional readers which can be so cordially 
 endorsed by a medical journal as can this one." — Therapeutic Gazette. 
 
 " This is a well-written, eminently practical volume, which covers the entire range of 
 private nursing as distinguished from hospital nursing, and instructs the nurse how best to 
 meet the various emergencies which may arise, and how to prepare everything ordinarily 
 needed in the illness of her patient." — American Journal of Obstetrics and Diseases of 
 Women and Children. 
 
 " It is a work that the physician can place in the hands of his private nurses with the 
 assurance of benefit." — Ohio Medical Journal. 
 
28 Medical Publications of W. B. Saunders. 
 
 STONEY'S MATERIA MEDICA FOR NURSES. 
 
 Materia Medica for Nurses. By Emily A. M. Stoney, Graduate of 
 the Training-School for Nurses, Lawrence, Mass. ; late Superintendent 
 of the Training-School for Nurses, Carney Hospital, South Boston, Mass. 
 Handsome octavo volume of 306 pages. Cloth, ^1.50 net. 
 
 The present book differs from other similar works in several features, all of which are 
 intended to render it more practical and generally useful. The general plan of the contents 
 follows the lines laid down in training-schools for nurses, but the book contains much use- 
 ful matter not usually included in works of this character, such as Poison-emergencies, 
 Ready Dose-list, Weights and Measures, etc., as well as a Glossary, defining all the terms 
 used in Materia Medica, and describing all the latest drugs and remedies, which have been 
 generally neglected by other books of the kind. 
 
 SUTTON AND GILES' DISEASES OF WOMEN. 
 
 Diseases of Women. By J. Bland Sutton, F.R.C.S., Assistant 
 Surgeon to Middlesex Hospital, and Surgeon to Chelsea Hospital, 
 London; and Arthur E. Giles, M.D., B.Sc. Lond., F.R.C.S. Edin., 
 Assistant Surgeon to Chelsea Hospital, London. 436 pages, hand- 
 somely illustrated. Cloth, ^2.50 net. 
 "The text has been carefully prepared. Nothing essential has been omitted, and its 
 
 teachings are those recommended by the leading authorities of the Asy."— Journal of the 
 
 Americati Medical Association. 
 
 THOMAS'S DIET LISTS AND SICK=ROOM DIETARY. 
 
 Diet Lists and Sick=Room Dietary. By Jerome B. Thomas, 
 M.D., Visiting Physician to the Home for Friendless Women and 
 Children and to the Newsboys' Home; Assistant Visiting Physician 
 to the Kings County Hospital. Cloth, $1.50. Send for sample sheet. 
 
 THORNTON'S DOSE=BOOK AND PRESCRIPTION=WRITING. 
 
 Dose=Book and Manual of Prescription=Writing. By E. Q. 
 
 Thornton, M.D., Demonstrator of Therapeutics, Jefferson Medical 
 College, Philadelphia. 334 pages, illustrated. Cloth, $1.25 net. 
 
 " Full of practical suggestions; will take its place in the front rank of works of this 
 sort." — Medical Record, New York. 
 
 VAN VALZAH AND NISBET'S DISEASES OF THE STOMACH. 
 Diseases of the Stomach. By William W. Van Valzah, M.D., 
 Professor of General Medicine and Diseases of the Digestive System 
 and the Blood, New York Polyclinic; and J. Douglas Nisbet, M.D., 
 Adjunct Professor of General Medicine and Diseases of the Digestive 
 System and the Blood, New York Polyclinic. Octavo volume of 674 
 pages, illustrated. Cloth, ^3.50 net. 
 
 " Its chief claim lies in its clearness and general adaptability to the practical needs of 
 the general prnctitioner or sturient. In these relations it is probaljly the best of the recent 
 special works on diseases of the stomach." — Chicago Clinical Review. 
 
 VECKI'S SEXUAL IMPOTENCE. 
 
 The Pathology and Treatment of Sexual Impotence. By Victor 
 G. Veckj, M D. From the second German edition, revised and en- 
 larged. Demi-octavo, about 300 pages. Cloth, ^2.00 net. 
 
 The subject of impotence has seldom been treated in this country in the truly scientific 
 spirit that it deserves. Dr. Vecki's work has long been favorably known, and tlie German 
 book has received the highest consideration. This edition is more than a mere translation, 
 for, although based on the German edition, it has been entirely rewritten in English. 
 
Medical Publications of W. B. Saunders. 29 
 
 VIERORDT'S MEDICAL DIAGNOSIS. Fourth Edition, Revised. 
 Medical Diagnosis. By Dr. Oswald Vierordt, Professor of Medi- 
 cine at the University of Heidelberg. Translated, with additions, 
 from the fifth enlarged German edition, with the author's permission, 
 by Francis H. Stuart, A. M., M. D. Handsome royal octavo volume 
 of 603 pages; 194 fine wood-cuts in text, many of them in colors. 
 Cloth, ^4.00 net; Sheep or Half Morocco, ^5-oo net. 
 
 " A treasury of practical information which will be found of daily use to every busy 
 practitioner who will consult it." — C. A. Lindsley, M.D., Professor of the Theory and 
 Practice of Medicine, Yale University . 
 
 " Rarely is a book published with which a reviewer can find so little fault as with the 
 volume before us. Each particular item in the consideration of an organ or apparatus, which 
 is necessary to determine a diagnosis of any disease of that organ, is mentioned ; nothing 
 seems forgotten. The chapters on diseases of the circulatory and digestive apparatus and 
 nervous system are especially full and valuable. The reviewer would repeat that the book is 
 one of the best — probably the best — which has fallen into his hands." — University Medical 
 Magazine. 
 
 WARREN'S SURGICAL PATHOLOGY AND THERAPEUTICS. 
 
 Surgical Pathology and Therapeutics. By John Collins Warren, 
 M.D., LL.D., Professor of Surgery, Medical Department Harvard 
 University; Surgeon to the Massachusetts General Hospital, etc. 
 Handsome octavo volume of 832 pages; 136 relief and lithographic 
 illustrations, 33 of which are printed in colors, and all of which were 
 drawn by William J. Kaula from original specimens. Revised and 
 Enlarged Edition in Preparation. 
 
 "There is the work of Dr. Warren, which I think is the most creditable book on 
 Surgical Pathology, and the most beautiful medical illustration of the bookmaker's art, that 
 has ever been issued from the American press." — Dr. Roswell Park, in the Harvard 
 Graduate Magazine. 
 
 " The handsomest specimen of bookmaking that has ever been issued from the American 
 medical press." — American Journal of the Medical Sciences. 
 
 " A most striking and very excellent feature of this book is its illustrations. Without 
 exception, from the point of accuracy and artistic merit, they are the best ever seen in a work 
 of this kind. Many of those representing microscopic pictures are so perfect in their coloring 
 and detail as almost to give the beholder the impression that he is looking down the barrel 
 of a microscope at a well-mounted section." — Annals of Surgery. 
 
 WOLFF ON EXAMINATION OF URINE. 
 
 Essentials of Examination of Urine. By Lawrence Wolff, M.D., 
 Demonstrator of Chemistry, Jefferson Medical College, Philadelphia, 
 etc. Colored (Vogel) urine scale and numerous illustrations. Crown 
 octavo. Cloth, 75 cents. 
 
 [See Saunders' Question- Compends , page 21.] 
 " A very good work of its kind — very well suited to its purpose." — Titnes and Register. 
 
 WOLFF'S MEDICAL CHEMISTRY. Fifth Edition, Revised. 
 
 Essentials of Medical Chemistry, Organic and Inorganic. 
 
 Containing also Questions on Medical Physics, Chemical Physiology, 
 Analytical Processes, Urinalysis, and Toxicology. By Lawrence 
 Wolff, M.D., Demonstrator of Chemistry, Jefferson Medical College, 
 Philadelphia, etc. Crown octavo, 222 pages. Cloth, ^i.oo net; inter- 
 leaved for notes, ^1.25 net. 
 
 [See Saunders' Question- Comf ends, page 21.] 
 
 "The scope of this work is certainly equal to that of the best course of lectures on 
 Medical Chemistry." — Pharmaceutical Era. 
 
CLASSIFIED LIST 
 
 Medical Publications 
 
 W. B. SAUNDERS, 
 
 925 "Walnut Street, Philadelphia. 
 
 ANATOMY, EMBRYOLOGY, 
 HISTOLOGY. 
 
 Clarkson — A Text-Book of Histology, 9 
 Haynes — A Manual of Anatomy, ... 13 
 Heisler — A Text-Book of Embryology, I3 
 Nancrede — Essentials of Anatomy, . . 18 
 Nancrede — Essentials 'of Anatomy and 
 
 Manual of Practical Dissection, . . . 18 
 Sample — Essentials of Pathology and 
 
 Morbid Anatomy, 25 
 
 BACTERIOLOGY. 
 
 Ball — Essentials of Bacteriology, ... 6 
 Crookshank — A Text- Book of Bacteri- 
 ology, 10 
 
 Frothingham— Laboratory Guide, . . II 
 Mallory and Wright — Pathological 
 
 Technique, 16 
 
 McFarland — Pathogenic Bacteria, . . 17 
 
 CHARTS, DIET-LISTS, ETC. 
 
 Griffith— Infant's Weight Chart, ... 12 
 
 Hart — Diet in Sickness and in Health, . 13 
 
 Keen — Operation Blanlc, 15 
 
 Laine — Temperature Chart 15 
 
 Meigs — Feeding in Early Infancy, . . 17 
 
 Starr — Diets for Infants and Children, . 26 
 Thomas — Diet-Lists and Sick-Room 
 
 Dietary, 28 
 
 CHEMISTRY AND PHYSICS. 
 
 Brockway — Essentials of Medical Phys- 
 ics, 7 
 
 Wolff — Essentials of Medical Chemistry, 29 
 
 CHILDREN. 
 
 An American Text-Book of Diseases 
 
 of Children, . . 3 
 
 Griffith — Care of the Baby, 12 
 
 Griffith — Infant's Weight Chart, ... 12 
 
 Meigs — Feeding in Early Infancy, . . 17 
 
 Powell — Essentials of Dis. of Children, 19 
 
 Starr — Diets for Infants and Children, . 26 
 
 DIAGNOSIS. 
 
 Cohen and Eshner— Essentials of Di- 
 agnosis, 9 
 
 Corwin — Physical Diagnosis, .... 9 
 
 Macdonald — Surgical Diagnosis and 
 Treatment, 16 
 
 Vierordt — Medical Diagnosis, .... 29 
 
 DICTIONARIES. 
 
 Borland — Pocket I)ictionary, .... ID 
 
 Keating— I'ronouncing Dictionary, . . 14 
 
 Morten — Nurse's Dictionary, .... 18 
 
 EYE, EAR, NOSE, AND THROAT. 
 
 An American Text- Book of Diseases 
 
 of the Eye, Ear, Nose, and Throat, . 3 
 De Schweinitz — Diseases of the Eye, . 10 
 Gleason — Essentials of Dis. of the Ear, 1 1 
 Jackson — Manual of Diseases of Eye, . 32 
 Jackson and Gleason — Essentials of 
 
 Diseases of the Eye, Nose, and Throat, I4 
 Kyle — Diseases of the Nose and Throat, 15 
 
 QENITO=URINARY. 
 
 An American Text-Book of Genito- 
 urinary and Skin Diseases, 4 
 
 Hyde and Montgomery — Syphilis and 
 the Venereal Diseases, ... . . . I3 
 
 Martin — Essentials of Minor Surgery, 
 
 Bandaging, and Venereal Diseases, . 16 
 Saundby — Renal and Urinary Diseases, 24 
 Senn — Genito-Urinary Tuberculosis, . 25 
 Vecki — Sexual Impotence, 28 
 
 GYNECOLOGY. 
 
 American Text-Book of Gynecology, 4 
 Cragin — Essentials of Gynecology, . . 9 
 Garrigues — Diseases of Women, ... 11 
 Long — Syllabus of Gynecology, ... 15 
 Penrose — Diseases of Women, .... 18 
 Pryor — Pelvic Inflammations, .... 32 
 Sutton and Giles— Diseases of Women, 28 
 
 MATERIA MEDICA, PHARMACOL- 
 OGY, AND THERAPEUTICS. 
 
 An American Text-Book of Applied 
 
 Therapeutics, 3 
 
 Butler — Text-Book of Materia Medica, 
 
 Therapeutics and Pharmacology, ... 8 
 Cerna — Notes on the Newer Remedies, 8 
 Griffin — Materia Med. and Therapeutics, 12 
 Morris — Essentials of Materia Medica 
 
 and Therapeutics, 17 
 
 Saunders' Pocket Medical Formulary, 24 
 Sayre — Essentials of Pharmacy, ... 24 
 Stevens — Essentials of Materia Medica 
 
 and Therapeutics, 26 
 
 Stoney — Materia Medica for Nurses, . . 28 
 Thornton — Dose-Book and Manual of 
 
 Prescription-Writing, 28 
 
 MEDICAL JURISPRUDENCE AND 
 TOXICOLOGY. 
 
 Chapman — Medical Jurisprudence and 
 Toxicology, ... .... 8 
 
 Semple — Essentials of Legal Medicine, 
 Toxicology, and Hygiene, 25 
 
Medical Publications of W. B. Saunders. 
 
 31 
 
 NERVOUS AND MENTAL 
 DISEASES, ETC. 
 
 Burr — Nervous Diseases, 7 
 
 Chapin — Compendium of Insanity, . . 8 
 Church and Peterson — Nervous and 
 
 Mental Diseases, 8 
 
 Shaw — Essentials of Nervous Diseases 
 
 and Insanity, 26 
 
 NURSING. 
 
 An American Text-Book of Nursing, 29 
 
 Griffith — The Care of the Baby, ... 12 
 
 Hampton — Nursing, 12 
 
 Hart — Diet in Sickness and in Health, 13 
 
 Meigs — Feeding in Early Infancy, . . 17 
 
 Morten — Nurse's Dictionary, .... 18 
 
 Stoney— Materia Medica for Nurses, . . 28 
 
 Stoney — Practical Points in Nursing, . 27 
 
 OBSTETRICS. 
 
 An Am erican Text- Book of Obstetrics, 4 
 
 Ashton — Essentials of Obstetrics, ... 6 
 
 Boisliniere — Obstetric Accidents, ... 7 
 
 Dorland — Manual of Obstetrics, . . . lo 
 
 Hirst — Text-Book of Obstetrics, ... 13 
 Norris — Syllabus of Obstetrics, . , . . .18 
 
 PATHOLOGY. 
 
 An American Text-Book of Pathology, 5 
 Mallory and ^A^^ight — Pathological 
 
 Technique, 1 6 
 
 Semple — Essentials of Pathology and 
 
 Morbid Anatomy, 25 
 
 Senn — Pathology and Surgical Treat- 
 ment of Tumors, 25 
 
 Stengel — Text- Book of Pathology, . . 26 
 Warren — Surgical Pathology and Thera- 
 peutics, 29 
 
 PHYSIOLOGY. 
 
 An American Text-Book of Physi- 
 ology, . ■ . 5 
 
 Hare — Essentials of Physiology, ... 13 
 
 Raymond — Manual of Physiology, . . 19 
 
 Stewart — Manual of Physiology, ... 27 
 
 PRACTICE OF MEDICINE. 
 
 An American Text-Book of the The- 
 ory and Practice of Medicine, .... 5 
 
 An American Year-Book of Medicine 
 and Surgery, 6 
 
 Anders — Text-Book of the Practice of 
 Medicine, 6 
 
 Lockwood — Manual of the Practice of 
 Medicine, 15 
 
 Morris — Essentials of the Practice of 
 Medicine, 1 7 
 
 Stevens — Manual of the Practice of 
 Medicine, 27 
 
 SKIN AND VENEREAL. 
 
 An American Text-Book of Genito- 
 urinary and Skin Diseases, 3 
 
 Hyde and Montgomery — Syphilis and 
 the Venereal Diseases, 1 3 
 
 Martin — Essentials of Minor Surgery, 
 Bandaging, and Venereal Diseases, . 16 
 
 Pringle — Pictorial Atlas of Skin Dis- 
 eases and Syphilitic Affections, ... 19 
 
 Stelwagon — Essentials of Diseases of 
 the Skin, 26 
 
 SURGERY. 
 
 An American Text-Book of Surgery, 5 
 An American Year-Book of Medicine 
 and Surgery 6 
 
 Beck — Manual of Surgical Asepsis, . . 7 
 DaCosta — Manual of Surgery, .... 10 
 International Text-Book of Surgery, . 32 
 
 Keen — Operation Blank, 15 
 
 Keen — The Surgical Complications and 
 
 Sequels of Typhoid Fever, 15 
 
 Macdonald — Surgical Diagnosis and 
 
 Treatment, 16 
 
 Martin — Essentials of Minor Surgery, 
 
 Bandaging, and Venereal Diseases, . 16 
 Martin — Essentials of Surgery, .... 16 
 
 Moore — Orthopedic Surgery, 17 
 
 Nancrede — Principles of Surgery, . . 32 
 Pye — Bandaging and Surgical Dressing, 19 
 Rowland and Hedley— Archives of 
 
 the Roentgen Ray, 19 
 
 Senn — Genito-Urinary Tuberculosis, . 25 
 
 Senn— Syllabus of Surgery, 25 
 
 Senn — Pathology and Surgical Treat- 
 ment of Tumors, . 25 
 
 Warren — Surgical Pathology and Ther- 
 apeutics, 29 
 
 URINE AND URINARY DISEASES. 
 
 Saundby — Renal and Urinary Diseases, 24 
 Wolff— Essentials of Examination of 
 Urine, 29 
 
 MISCELLANEOUS. 
 
 Abbott — Hygiene of Transmissible Dis- 
 eases, 32 
 
 Bastin — Laboratory Exercises in Bot- 
 any, 7 
 
 Gould and Pyle — Anomalies and Curi- 
 osities of Medicine, 11 
 
 Grafstrom^ — Massage, ....... 12 
 
 Keating — How to Examine loi° Life 
 
 Insurance, » - . « 14 
 
 Rowland and Hedley — Archives of 
 
 the Roentgen Ray, I9 
 
 Saunders' Medical Hand-Atlases, . . 2 
 Saunders' New Series of Manuals, 22, 23 
 Saunders' Pocket Medical Formulary, . 24 
 Saunders' Question-Compends, . . 20, 21 
 Senn — Pathology and Surgical Treat- 
 ment of Tumors, -25 
 
 Stewart and Lawrance — Essentials of 
 
 Medical Electricity, 27 
 
 Thornton — Dose-Book and Manual of 
 
 Prescription-Writing, . 28 
 
 Van Valzah and Nisbet^Diseases of 
 the Stomach, 28 
 
JUST ISSUED, 
 
 THE INTERNATIONAL TEXT=BOOK OF SURGERY. In two volumes. 
 
 By Americaii and British authors. Edited by J. Collins Warren, M. D., LL.D., 
 Professor of Surgery, Harvard Medical School, Boston ; Surgeon to the Massachusetts 
 General Hospital ; and A. Pearce Gould, M. S., F. R. C. S., Eng., Lecturer on 
 Practical Surgery and Teacher of Operative Surgery, Middlesex Hospital Medical 
 School; Surgeon to the Middlesex Hospital, London, England. Vol. L— General 
 Surgery. — Handsome octavo volume of 947 pages, vi^ith 458 beautiful illustrations in 
 the text and 9 lithographic plates. Vol. H. — Special or Regional Surgery — is now in 
 press, and will be ready Jan. i, 1900. Prices per volume: Cloth, ^5.00 net; Half 
 Morocco, $6.00 net. 
 
 KYLE ON THE NOSE AND THROAT. 
 
 Diseases of the Nose and Throat. By D. Braden Kyle, M. D., Clinical Pro- 
 fessor of Laryngology and Rhinology, Jefferson Medical College, Philadelphia; Con- 
 sulting Laryngologist, Rhinologist, and Otologist, St. Agnes' Hospital. Octavo volume 
 of 646 pages, with over 150 illustrations and 6 lithographic plates. Prices : Cloth, $4.00 
 net; Half Morocco, ^5.00 net. 
 
 PRYOR-PELVIC INFLAMMATIONS. 
 
 The Treatment of Pelvic Inflammations through the Vagina. By W. R. 
 
 Pryor, M. D., Professor of Gynecology in the New York Polyclinic. i2mo volume 
 of 248 pages, handsomely illustrated. Cloth, ^2.00 net. 
 
 ABBOTT ON TRANSMISSIBLE DISEASES. 
 
 The Hygiene of Transmissible Diseases : their Causation, Modes of 
 Dissemination, and Methods of Prevention. By A. C. Abbott, M. D., Pro- 
 fessor of Hygiene in the University of Pennsylvania ; Director of the Laboratory of 
 Hygiene. Octavo volume of 311 pages, containing a number of charts and maps, and 
 numerous illustrations. Cloth, ^2.00 net. 
 
 HEISLER'S EMBRYOLOGY. 
 
 A Text=Book of Embryology. By John C. Heisler, M.D., Professor of 
 Anatomy in the Medico-Chirurgical College, Philadelphia. Octavo volume of 405 
 pages, with 190 illustrations, 26 in colors. Cloth, ^2.50 net. 
 
 JACKSON— DISEASES OF THE EYE. 
 
 A Manual of Diseases of the Eye. By Edward Jackson, A. M., M. D., some- 
 lime Professor of Diseases of the Eye in the Philadelphia Polyclinic and College for 
 Graduates in Medicine. l2mo volume of over 535 pages, with 178 beautiful illustra- 
 tions, mostly from drawings by the author. 
 
 NANCREDE -PRINCIPLES OF SURGERY. 
 
 Lectures on the Principles of Surgery. By Chas. B. Nancredk, M.D., LL.D., 
 
 Professor of Surgery and of Clinical Surgery, University of Michigan, Ann Arbor. 
 Octavo volume of 398 pages, illustrated. Cloth, ^2.50 net. 
 
 IN PREPARATION FOR EARLY PUBLICATION. 
 
 OQDEN— URINARY ANALYSIS. 
 
 A Manual of Urinary Analysis, hy J. Bkrcen Ogden, M. D., Assistant in 
 Chemistry, Harvard University Medical School. 
 
 STONEY— SURGICAL TECHNIQUE FOR NURSES. 
 
 Surgical Technique for Nurses. liy Emily A. M. Stonky, Graduate of Training 
 School for Nurses, Lawrence, Mass. ; late Superintendent of Training School for Nurses, 
 Carney Hospital, South Boston, Mass.