Part I; and The Census Bulletin (104) on Mortality Statistics for 1908.

Part I; and The Census Bulletin (104) on Mortality Statistics for 1908. 24 INTRODUCTION Other evidences of the benefits resulting from the appli- cation of the principles of modern hygiene are the marked reduction in the sick- and death-rates due to infectious diseases, and the gradual increase in the average expecta- tion of life in those countries or places where systematic prophylactic and sanitary work is béing done. Thus, in the so-called “registration-area” of the United States the death-rate for diphtheria has dropped from 70.1 per 100,000 of population in 1890 to 14.5 in 1916; that of malarial fever, from 22.1 to 3; of typhoid fever, from 46.3 to 13.3; and of tuberculosis, from 245.4 to 141.6; while the general death-rate of the same ‘area”’ has fallen in the same period of, time from 19.6 to 14 per 1000 of population.! Likewise, the average duration of life, according to high authority, is rapidly increasing—e. g., the rate of increase in Europe “during the latter half of the nine- teenth century was about seventeen years per century, and in Germany, where medical and sanitary science has reached the highest development, about twenty-seven years per century.”” The only comparative statistics available in this country are for Massachusetts, where life is lengthening at the rate of about fourteen years per century? Who then shall say that the study and practice of hygiene and sanitation—of preventive medi- cine—is of no practical value? It will be well to note at this point the marked reflex influence that the adoption of an accurate or improved method for the registration of vital statistics has upon the sanitary status of any part of the population. Wher- ever a city or a State has adopted such a method there 1 It should be noted that the above rates are not strictly comparable, as the “registration area" has been materially changed and increased during the period in question. Thus, it represented 40.5 per cent. of the population and but 7.1 per cent. of the land area of the country in 1890, as against 70.2 per cent. of the population and 44 per cent. of the land area in 1916. 1 Report on National Vitality, Its Waste and Conservation: Irving Fisher, 1909. CONTINUOUS PROPHYLAXIS NECESSARY 25 has almost immediately followed an improvement in its morbidity- and mortality-rates, for which reason the conditions obtaining in the component parts of the total “registration-area” of the United States are undoubtedly better than in similar or comparable portions of the remainder of the country. The registration-area is con- sidered to be the combined areas or localities where, in census years, “the deaths obtained from registration sources constituted 90 or more per cent. of the total (registration plus additions from enumerators), and the additions from the census enumerators’ returns did not exceed 20 per cent. of the number reported by them”; and, in other than census years, where a similar accuracy of official registration of vital statistics obtains. Nevertheless, there is still much to be done. Tuber- culosis, which is said to cause from one-seventh to one- fourth of all the deaths in the civilized world, is a pre- ventable disease, and we now not only know its cause, but also have efficient means for cure in a large proportion of cases, as well as for its general prevention. So with a number of the other infectious diseases. Almost every day marks an increase in our knowledge of their etiology and the securing of immunity from them; and not only must physicians make use of this knowledge as they acquire it, and employ their utmost endeavors to secure the enactment and enforcement of sanitary laws and regulations, but they must also realize that a large part of their work lies in the enlightenment and education of the people in all matters pertaining to the public health." The plague that was the bane of Europe centuries ago 1 It is encouraging to find that, although over 10.5 per cent. of the whole number of deaths recorded in Philadelphia in 1916 were caused by con- sumption, a progressive and marked lowering of the death-rate from this disease in that city is taking place, and that, notwithstanding an increase in population of 76 per cent., the fatalities from this disease are but few more in number than they were over thirty years earlier. For example, the deaths from pulmonary tuberculosis in 1885 numbered 2821, and in 1886 were 2834, rates respectively of 297 and 292 per 100,000; while in 19 16 there were only 2916 deaths, or a rate of 170.6 per 100,000 living. 26 INTRODUCTION and that has been a scourge to Asia since, occasionally threatens us at our western gates and is rife in some of our newly acquired colonial possessions. The infectivity of pneumonia is not appreciated by the laity nor by many physicians. The death-rate (137.3) in the Registration area in 1916 due to all forms of this disease was almost as high as that for tuberculosis of the lungs (141.6) and was only exceeded by the latter and by that for acute endocarditis and other organic diseases of the heart (150.1). We must not forget that pneumonia, which can be so pestilent, is “more or less limited to centers, corresponding in the main to the most densely popu- lated area, with their allied conditions of squalor and poverty,”! and that it is our duty and for our own safety to improve the sanitary conditions and environments of such areas and centers. With our present knowledge of the value of vaccination, there have been far too many epidemics of smallpox within comparatively recent years. Carelessness in the application of protective measures has cost many lives and much money. There can be no safe cessation in prophylactic efforts. So, also, each and every one of the communicable maladies must be continually investigated and studied, and all positive information gained concerning them must in turn be imparted to the people who need protection against them. On the other hand, it is becoming more and more evident that any community may have good health, that is willing to pay for it, and that low sick- and death-rates largely depend upon an efficient administration of the functions of public health service. Order of Study.—In the preparation for a study like the one on which we are about to enter there is some ques- tion as to just what may be the most advantageous order and arrangement of the subjects to be treated. For in- 1 J. M. Anders, Journal of American Medical Association, May 9, 1903. ?The deaths from smallpox in the registration-area of the United States for the years 1900 to 1904, inclusive, numbered 5898, this repre- senting an average annual death-rate of 3.7 per 100,000 of population. DUTY OF PHYSICIANS 27 stance, it would be interesting to discuss our science in its relation, in turn, to the individual, the household, and the people in general—that is, personal, domestic, and public hygiene; and to show wherein the treatment of these sub- divisions is similar and wherein they differ. Such a three- fold consideration would be not only logical, but extremely instructive as well. _ _ However, since the bacteria and other microérganisms have been shown to have so important a part in many of the processes intimately connected with health and disease, it will doubtless be advisable to devote the next chapter to a brief review of the science of parasitology. This done, it seems to the writer that we shall, as beginners obtain a more comprehensive and thorough view of our subject if we pursue a method somewhat as follows: First, to discuss air, water, and food—three things essen- tial to life—in the varying conditions and circumstances under which they may affect the physical welfare, either for good or bad, of the individual or of the community. Then to take up, in such order as may seem best, the other themes, such as climatology, habitations, disinfec- tion and quarantine, disposal of sewage, clothing, exercise, school hygiene, etc., whose consideration, on account of their influence in the preservation of health and prevention of disease, is only a degree less important than those already mentioned. In this way, while the whole ground may not be covered, the importance of the various subdivisions may be estimated in their relationship to one another, and we shall be the better prepared to pursue the study as later opportunity may offer. It is doubtless in place just here to review briefly the reasons why it is the special duty of the physician to be able to recognize and correct insanitary conditions where- ever they may be found, and why he should make par- ticular and constant study of the science in all its branches and developments. Every true physician soon finds that the respect and affection of his patients and associates are worth far more 28 INTRODUCTION than mere mercenary gain, and that his highest aim should be to prevent disease rather than simply to cure it; and, though this may seem to militate against his personal in- terests, he is unworthy the name of physician if his object and purpose be solely or primarily to make money. How- ever, the observer quickly learns that in a community kept in good health and sanitary condition there will always be more or less need of a doctor’s services in spite of every effort to prevent sickness, and that such a community will pay more promptly and more liberally for such services than one in which sanitary precau- tions are neglected. Health means ability to work and to earn good wages; and a healthy community means more business, more money, and more comforts. More- over, as a rule, good wages insure prompt and willing payment of the doctor’s bills as well as of others. We may note here the close relations existing between sanitary science and social and political economy—a relationship which is very intimate, as we shall see from time to time in our work, for as, the physical condition of a people is bettered, it becomes more possible and more certain that they will likewise improve both mentally and morally. Again, though the science of hygiene and sanitation is comparatively a new one, public attention is being strongly directed toward it, not only because it vitally interests every one, but because new discoveries and new appli- cations of the laws pertaining to it are being constantly made, which are, in turn, swiftly given to the world by both the scientific and the popular press. This creates a demand for first-class investigators, teachers and workers, which demand is bound to increase in the near future and promises materially to exceed the supply. In fact, within a very few years not only the medical but also the academic and scientific schools of the country will doubtless be compelled by public opinion to establish in their faculties well-equipped and liberally endowed chairs of hygiene and sanitary science, and it will be from the ranks of the educated physicians of the country that these teachers NEED FOR TEACHERS AND SANITARIANS 29 and scientists must naturally come. It will not be long before the people in general realize that it is fully as important that the college student or graduate be instructed how to do his part in taking care of the health of himself, his future family and the community in which he is to reside, as that he shall be well taught in the abstract principles of theology or the classics of dead languages. So, also, considerably more time and attention than are now accorded to it should be given to hygiene in the work of the various normal schools for teachers. The graduates of these schools will have much of the physical as well as the mental welfare of thousands of young and growing children in their keeping, and it is unquestionably their duty to prevent or obviate the ills of school-life as far as lies in their power, and to inculcate and give instruc- tion in habits of living which will continually tend to preserve and improve the physical health of those under | their care. The large proportion of young men in this country ‘recently rejected as being unfit for military service because of physical deficiencies has awakened public interest to the importance of this subject as never before and methods and means are being sought whereby the tremendous loss in economic efficiency due to this cause may be prevented. There is also need for trained sanitarians in the service of the various states and the large municipalities, and there is now an actual demand for such men and women with no corresponding supply in view. Lastly, the time has come when a physician must neces- sarily have a knowledge of hygiene, preventive medicine, and sanitary science. Many states require as thorough examinations in this as in any other branch of medicine before granting the right to practise within their boun- daries. Even more so do the Army Medical, the Navy Medical and the Public Health Services of the Government, lay stress on this branch and the constant demand for an increased personnel in each of these as well as the experi- 30 INTRODUCTION ence gained by all three during the late world war, must emphasize the value and necessity of a thorough knowledge of hygiene, sanitation and preventive medicine on the part of those who may anticipate enrollment in any one of these branches of the public service. Moreover, the people generally, as has been intimated, are awakening to an interest in sanitary matters and the prevention of disease, and expect their physicians to be well versed on all pertaining subjects; if they find one lacking in knowledge or interest in this respect, they are apt to think, rightly or wrongly, that he will also be deficient in the other branches of medicine. Happily these causes all combine to place preventive ' on the same high plane with curative medicine, and the time has passed in which the chair of hygiene and pre- ventive medicine did not have a primary place in any thorough medical school. May the day soon come when it shall have at least equal importance in the curricula of all academic and normal colleges and schools! It is evident that the successful physician and practical student of hygiene must have a thorough knowledge of three things: (1) Health and its laws; how to obtain and preserve it. This of course, implies a knowledge of the human body and its functions, viz., of anatomy, physi- ology, and physiologic chemistry. 2. Disease and_ its causes and nature. He must also understand the dis- tinction between diseases due to causes external and those due to causes internal to the body; and that while some of these causes may be prevented or modified, others, with our present knowledge, may not be so readily overcome. 3. Therapeutic agents, both preventive and curative. He must be conversant with and know how to use those which he has at his disposal, including not only drugs, but also all substances and forces that he can make efficacious to his purpose. The workman must know his tools to be able to use them intelligently. Health is “that condition of the body and its organs necessary to the proper performance of their normal DEFINITION OF HEALTH AND DISEASE 31 functions”; and disease may be defined as “a condition of the body marked by inharmonious action of one or more of the various tissues or organs, owing to abnormal condition or structural change.” It is, accordingly, well to consider briefly the nature and causes of disease, that we may the better understand the influence upon its pre- vention or production of all those varying factors, phases, and conditions of our environment which we hope to study in our work. Disease is a pathological or abnormal physiological state, not a spiritual thing; a condition, not a theory. Conse- quently it is to be fought and, if possible, conquered with matter, natural forces, and physical means, though not necessarily with violence. In fact, when once we under- stand the minuteness and delicate structure of the ulti- mate cells and tissues affected, we realize that oftentimes the gentlest application of the forces and means employed may be the most helpful and efficient. But when one has seen the ravages caused by disease, as revealed in the pathological laboratory and at autopsies, not to speak of its manifestations in the living as seen in the sick- room and in hospitals, I am sure that he cannot logically, even for a moment, give credence to those who proclaim that it can be dissipated by the mere action of mind or of faith or by any other than rational and scientific meas- ures. Virchow gave a priceless boon to modern medicine in his theory of cellular pathology and in showing its superiority to the old humoral theories and a priori rea- soning. He wrote “whatever outside of a cell acts upon it (abnormally), works a mechanical or chemical change within it, which change is disorder or disease.” The sooner we realize that the laws of physics and chemistry govern cell life and action and, consequently, the func- tions and organs of the body, the more accurate will be the treatment and the more certain the prevention of disease. For convenience sake, diseases may be divided into two main classes, somewhat different in their origin, nature, 32 INTRODUCTION and character, although the line between the two is not always clearly marked. Diseases of the first class arise within the body, and may be called autogenetic. They are usually due to some alteration or disturbance of nu- trition and assimilation, such as irregular absorption of products of digestion; or of function, such as that of elimi- nation, to either of which, as well as to other similar causes, various auto-intoxications may be due. The sec- ond class comprises those which are due to causes from without, favored, it may be, by either internal or external predisposing conditions, but each malady of necessity depending upon the reception or inoculation of the spe- cial cause, which cause has the power of reproduction and development, of vitality and virulence. Such diseases are called contagious, infectious, specific, inoculable, or zymotic.' In the first class, with our present knowledge, we may place such maladies as gout, diabetes, neurasthenia, etc.; while into the second will obviously fall all that are now known to be due to living “germs” or organisms, such as cholera, typhoid fever, malaria, etc. However, we must not overlook the impulses often given to the causation of certain members of the second class by faulty conditions of nutrition or assimilation, as is especially exemplified in many cases of tuberculosis. The char- acter of the soil may influence the growth and product of a plant almost as much as the species itself, and so the difference in constitution and tissue of individuals may ‘In this connection the following quotation from Sedgwick is inter- esting: ‘Diseases may be regarded as due cither to defects in the con- stitution or construction of the vital mechanism, or else to external unfavorable influences acting upon it. From the point of view of origin or causation, all diseases may be divided into two classes, vis.: (I) Consti- tutional, or (II) Environmental. This classification, while open to iy objections, is of the highest value to the physiologist and the sanitarian, for it brings the former tace to face with intrinsic, structural, or organic defects in the mechanism, while the attention of the latter is concen- trated upon those abnormal external influences which act unfavorably upon the organism, and which he must seek, and may be able to re- move.” Principles of Sanitary Science and Public Health, 1902, p. 10. PROPHYLAXIS 33 materially determine the variations in symptoms and viru- lence so often manifested by an infectious malady. A third class or a subdivision of diseases might also be indicated, which would include those disturbances which are almost purely psychical and whose symptoms are largely notional and the result of perverted imagination or coérdination. But it is a question wh