The malformations are divided anatomically into those characterized, first, by excess formation, second, by deficient formation, third, by abnormal displacement of parts. They are due to intrinsic causes which are in the germ, and which may be due to some unusual conditions in either the male or female germ cell or an imperfect commingling of the germinal material, and to extrinsic causes which physically, as in the nature of a shock or chemically as by the action of a poison, may affect the embryo through the mother. Malformations are made more numerous in chickens by shaking the eggs before brooding. A number of malformations are produced by accidental conditions arising in the environment; for instance, the vascular cord connecting mother and child may become wound around parts constricting them or even cutting them off, and the membrane around the child may become adherent to certain parts and prevent the development of these. The extrinsic causes are more operative the more unfavorable is the environment of the mother. Malformations are more common in illegitimate children than in legitimate and more common in alcoholic mothers; there is an unfavorable environment of poverty in both cases, added to in the latter and usually in the former by the injurious action of the alcohol.

The more extensive malformations have no effect on heredity, because the subjects of them are incapable of procreation. The malformations which arise from the accidents of pregnancy and which are compatible with a perfectly normal germ are in the nature of acquired characteristics and are not inherited. Those malformations, however, which are due to qualities in the germinal material itself are inherited, and certain of them with remarkable persistence. There are instances in which the slight malformation consisting in an excess of fingers or toes has persisted through many generations. It may occasionally lapse in a generation to reappear later. In certain cases, notably in the bleeders, the inheritance is transmitted by the female alone, in other cases by the sexes equally, but there are no cases of transmission by the male line only. It is evident that when the same malformation affects both the male and the female line the hereditary influence is much stronger. A case has been related to me in which most of the inhabitants in a remote mountain valley in Virginia where there has been much intermarriage have one of the joints of the fingers missing. There is a very prevalent idea that in close intermarriage in families variations and malformations often unfortunate for the individual are more common. All experimental evidence obtained by interbreeding of animals shows that close interbreeding is not productive of variation, but that variations existing in the breed become accentuated. Variations either advantageous or disadvantageous for the race or individual may either of them become more prevalent by close intermarriage. It seems, however, to have been shown by the customs of the human race that very close intermarriage is disadvantageous.

Eugenics, which signifies an attempt at the betterment of the race by the avoidance of bad heredity, has within recent years attracted much attention and is of importance. Some of its advocates have become so enthusiastic as to believe that it will be possible to breed men as cattle and ultimately to produce a race ideally perfect. It is true that by careful selection and regulation of marriage certain variations, whether relating to coarse bodily form or to the less obvious changes denoted by function, can be perpetuated and strengthened. That the Semitic race excels in commerce is probably due to the fact that the variation of the brain which affected favorably the mental action conducive to this form of activity, was favorable for the race in the hostile environment in which it was usually placed and transmitted and strengthened by close intermarriage. It is impossible, however, to form a conception of what may be regarded as an ideal type of the human species. The type which might be ideal in a certain environment might not be ideal in another, and environment is probably of equal importance with the material. The eugenics movement has enormously stimulated research into heredity by the methods both of animal experimentation and observation, and study of heredity in man. As in all of the beginning sciences there is not the close inter-relation of observed facts and theory, but there is excess of theory and dearth of facts. Certain considerations, however, seem to be evident. It would seem to be evident that individuals should be healthy and enabled to maintain themselves in the environment in which they are placed, but the qualities which may enable an individual successfully to adapt himself to factory life, or life in the crowds and strong competition of the city, may not be, and probably are not, qualities which are good for the race in general or for his immediate descendants. At present our attempts to influence heredity should be limited to the heredity of disease only. We can certainly say that intermarriage between persons who have tuberculosis or in whose families the disease has prevailed is disadvantageous for the offspring; the same holds true for insanity and for nervous diseases of all sorts, for forms of criminality, for alcoholism, and for those diseases which are long enduring and transmitted by sexual contact such as syphilis and gonorrhoea. It is of importance that the facts bearing on the hereditary transmission of disease should become of general knowledge, in order that the dangers may be known and voluntarily avoided. No measures of preventive medicine are successful which are not supported by a public educated to appreciate their importance, and the same holds true of eugenics. How successful will be public measures leading to the prevention of offspring in the obviously unfit by sterilization of both males and females is uncertain. It is doubtful whether public sentiment at the present time will allow the measure to be thoroughly carried out. Some results in preventing unfit heredity may be attained by the greater extension of asylum life, but the additional burden of this upon the labor of the people would be difficult to bear. At best such measures would only be carried out in the lower class of society.



CHAPTER XI

CHRONIC DISEASES.—DISEASE OF THE HEART AS AN EXAMPLE.—THE STRUCTURE AND FUNCTION OF THE HEART.—THE ACTION OF THE VALVES.—THE PRODUCTION OF HEART DISEASE BY INFECTION.—THE CONDITIONS PRODUCED IN THE VALVES.—THE MANNER IN WHICH DISEASE OF THE VALVES INTERFERES WITH THEIR FUNCTION.—THE COMPENSATION OF INJURY BY INCREASED ACTION OF HEART.—THE ENLARGEMENT OF THE HEART.—THE RESULT OF IMPERFECT WORK OF THE HEART.—VENOUS CONGESTION.—DROPSY.—CHRONIC DISEASE OF THE NERVOUS SYSTEM.—INSANITY.—RELATION BETWEEN INSANITY AND CRIMINALITY.—ALCOHOLISM AND SYPHILIS FREQUENT CAUSES OF INSANITY.—THE DIRECT AND INDIRECT CAUSES OF NERVOUS DISEASES.—THE RELATION BETWEEN SOCIAL LIFE AND NERVOUS DISEASES.—FUNCTIONAL AND ORGANIC DISEASE.—NEURASTHENIA.

Chronic diseases are diseases of long duration and which do not tend to result in complete recovery; in certain cases a cause of disease persists in the body producing constant damage, or in the course of disease some organ or organs of the body are damaged beyond the capacity of repair, and the imperfect action of such damaged organs interferes with the harmonious inter-relation of organs and the general well-being of the body. The effect of damage in producing chronic disease may not appear at once, for the great power of adaptation of organs and the exercise of reserve force may for a time render the damage imperceptible; when, however, age or the supervention of further injury diminishes the power of adaptation the condition of disease becomes evident. Chronic disease may be caused by parasites when the relation between host and parasite is not in high degree inimical, as in tuberculosis, gonorrhoea, syphilis, most of the trypanosome diseases and the diseases produced by the higher parasites. In certain cases the chronic disease represents really a series of acute onsets; thus in the case of the parasites there may be periods of complete quiescence of infection but not recovery, the parasites remaining in the body and attacking when the defences of the body are in some way weakened. In such cases there may be temporary immunity produced by each excursion of the disease, but the immunity is not permanent nor is the parasite destroyed. There is a further connection between chronic disease and infection in that the damage to the organs, which is the great factor underlying chronic disease, is so often the result of an infection.

The infectious diseases are those of early life; chronic disease, on the other hand, is most common in the latter third of life. This is due to the fact that in consequence of the general wear of the body this becomes less resistant, less capable of adaptation, and organic injury, which in the younger individual would be in some way compensated for, becomes operative. The territory of chronic disease is so vast that not even a superficial review of the diseases coming under this category can be attempted in the limits of this book, and it will be best to give single examples only, for the same general principles apply to all. One of the best examples is given in chronic disease of the heart.

The heart is a hollow organ forming a part of the blood vascular system and serving to give motion to the blood within the vessels by the contraction of its strong muscular walls. It is essentially a pump, and, as in a pump, the direction which the fluid takes when forced out of its cavity by the contraction of the walls diminishing or closing the cavity space, is determined by valves. The contraction of the heart, which takes place seventy to eighty times in a minute, is automatic and is due to the essential quality of the muscle which composes it. The character, frequency and force of contraction, however, can be influenced by the nervous system and by the direct action of substances upon the heart muscle. The heart is divided by a longitudinal partition into a right and left cavity, and these cavities are divided by transverse septa, with openings in them controlled by valves, each into two chambers termed auricle and ventricle. The auricle and ventricle on each side are completely separated.

The circulation of the blood through the heart is as follows: The blood, which in the veins of the body is flowing towards the heart, passes by two channels, which respectively receive the blood from the upper and lower part of the body, into the right auricle. When this becomes distended it contracts, forcing the blood into the right ventricle; the ventricle then contracts and sends the blood into the arteries of the lungs, the passage of blood into the auricle being prevented by valves which close the opening between auricle and ventricle when the latter contracts upon its contents. When the ventricle empties by its contraction the wall relaxes and the back flow from the artery is prevented by crescentic-shaped valves placed where the artery joins the ventricle. A similar arrangement of valves is on the left side of the heart. The pressure given the blood by the contraction of the right ventricle sends it through the lungs; from these, after it has been oxygenated, it passes into the left auricle, then into the left ventricle and from this into the great artery of the body, the aorta, which gives off branches supplying the capillaries of all parts of the body. Both of the auricles and both of the ventricles contract at the same, time, the ventricular contraction following closely upon the contraction of the auricles. Contraction or systole is followed by a pause or diastole during which the blood flows from the veins into the auricles. The work which the right ventricle accomplishes is very much less than that of the left, and the right ventricle has a correspondingly thinner wall. The size of the heart is influenced by the size and the occupation of the individual being larger in the large individual than in the small, and larger in the active and vigorous than in the inactive. Generally speaking, the heart is about as large as the closed fist of its possessor.

Imperfections of the heart which interfere with its action may be the result of failure of development or disease. An imperfect heart which can, however, fully meet the limited demands made upon it in intra-uterine life, may be incapable of the work placed upon it in extra-uterine life. Children with imperfectly formed hearts may be otherwise perfect at birth, but they have a bluish color due to the imperfect supply of the blood with oxygen, and are known as blue babies. The condition becomes progressively worse due to the progressive demands made upon the heart, and death takes place after some days or months or years, the time depending upon the degree of the imperfection.

Much of the damage of the heart in later life is due to infection. The valves of the heart are a favorite place for attack by certain sorts of bacteria which get into the blood. This is due to the prominent position of the valves which brings them in contact with all the blood in the body, the large extent and unevenness of the surface and to the rubbing together and contact of their edges when closed. At the site of infection there is a slight destruction of tissue and on this the blood clots producing rough wart-like projections. The valves in some cases are to a greater or less extent destroyed, they may become greatly thickened and by the deposit of lime salts converted into hard, stony masses. Essentially two conditions are produced. In one the thickened, unyielding valves project across the openings they should guard, and thus by constricting the opening interfere with the passage of blood either through the heart or from it. In the other the valves are so damaged that they cannot properly close the orifices they guard, and on or after the contraction of the cavities there is back flow or regurgitation of the blood. If, for instance, the orifice of the heart into the aorta is narrowed, then the left ventricle can only accomplish its work of projecting into the aorta a given amount of blood in a given time by contracting with greater force and giving a greater rapidity to the stream passing through the narrow orifice. This the heart can do because, like all other organs of the body, it has a large reserve force which enables it, even suddenly, to meet demands double the usual, and like all other muscles of the body it becomes larger and stronger by increased work. The condition here is much simpler than when the same valve is incapable of perfect closure, or when both obstruction and imperfect closure, are combined as they not infrequently are. In such cases the ventricle must do more than in the first case. It must force through the orifice, which may be narrowed, the amount of blood which is necessary to keep up the pressure within the aorta and give to the circulation the necessary rapidity of flow, and also the amount which flows back into the heart through the imperfectly acting valve. This it can do by contracting with greater force upon a larger amount of blood, the cavity becoming enlarged to receive this. Not only may such damage to the valves be produced, but the muscular tissue of the heart may suffer from defective nutrition or from the effect of poisons, whether these are formed in the body as the effect of disease or introduced from without; or in consequence of disease in the lungs the flow of blood through them may be impeded, or disease elsewhere in the body, as in the kidneys may, by increasing the pressure of the blood within the arteries, throw more than the usual amount of work upon the heart.

The power of the heart in meeting these conditions, however various they are and however variously they act, seems little short of marvellous, and it goes on throwing three and one-third ounces of blood seventy or eighty times a minute into a tube against nine feet of water pressure, working often perfectly under conditions which would be fatal to a machine. As long as this goes on the injury is said to be compensated for; the increased work which the heart is able to accomplish by the exercise of its reserve force and by becoming larger and stronger enables it to cope with the adverse conditions. With increased demand for work there is a gradual diminution of the reserve force. An individual may be able to carry easily forty pounds up a hill and by exerting all his force may carry eighty pounds, but if he habitually carries the eighty pounds, even though the muscles become stronger by exercise the load cannot be again doubled. The dilatation of the heart which is so important in compensation is fraught with danger, because any weakening of the muscle increases the dilatation, until a point is reached when, owing to the dilatation of the orifices between auricles and ventricles, the valves become incompetent to close them.

When the heart is not able to accomplish its work, the effect of the condition becomes apparent by the accumulation of blood within the veins and a less active circulation. This affects the nutrition and the capacity for work of all the organs of the body, and the imperfect function of the organs may in a variety of ways make still greater demands upon an already overloaded heart. Other conditions supervene. The increased pressure within the veins and capillaries due to the impossibility of the blood in the usual amount passing through or from the heart increases the amount of fluid in the tissues. There is always an interchange between the blood within the vessels and the fluid outside of them; the passage of fluid from the vessels is facilitated by the increased pressure within them, just as pressure upon a filtering fluid increases the rapidity of filtration, and the increase of pressure within veins and capillaries impedes passage of tissue fluid into them. The fluid accumulates within the tissues leading to dropsy, or the accumulation may take place in some of the cavities of the body. The diminished flow of blood through the lungs prevents its proper oxygenation; this may also be interfered with by the accumulation of fluid within the air spaces of the lungs.

Every additional burden thrown upon the heart increases the evil. In women the additional burden of pregnancy may suffice to overcome a compensation which has been perfect, and the same may result from an acute attack of disease. Age, diminishing as it does the capacity for work in all organs, diminishes the compensation capacity of the heart, and a heart which at the age of forty acts perfectly may break down at the age of fifty. Compensation may be gained in other ways, as by reducing the demand made upon the heart by changing the mode of life, by leading an inactive rather than an active life, by avoiding excitement or any condition which entails work of the heart. Social conditions are of great importance; it makes a great difference whether the unfortunate possessor of such a heart be a stevedore whose capital lies in the strength of his muscles, or a more fortunately placed member of society for whom the stevedore works and whose occupation or lack of occupation does not interfere with the adjustment of his external relations to the condition of his heart.

Disease of the nervous system does not differ from disease elsewhere. The system is complex in structure and in function. It consists in nerves which are composed of very fine fibrils distributed in all parts of the body and serve the purpose of conduction, and a central body composed of the brain and spinal cord which is largely cellular in character; it receives impressions by means of the nerves and sends out impulses which produce or affect action in all parts. By means of the organs of special sense, the brain receives impressions from the outer world which it transforms into the concepts of consciousness. Many of the impressions which the central nervous system receives from nerves other than those of special sense and even many of the impressions from these and the impulses which it sends out do not affect consciousness. The memory faculty is seated in the brain and all parts of the brain are closely connected by means of small nerve fibres. The nervous system plays an important part in the internal regulation and coordination of all parts of the body, and it is by means of this that the general adjustment of man with his environment is effected.

Malformations of the brain, except very gross conditions which are incompatible with extra-uterine existence, are not very common. At birth those parts of the brain which are the seat of memory and what are understood as the higher faculties are very imperfectly developed. Variations in structure are extremely common, there are differences in different individuals in the nerves and in the number, size, form and arrangement of the nerve cells, and so complex is the structure that considerable variation can exist without detection. The tissue of the central nervous system has a considerable degree of resistance to the action of bacteria, but is, however, very susceptible to injury by means of poisons. Serious injury or destruction of tissue of the brain and spinal cord is never regenerated or repaired, but adjustment to such conditions may be effected by reciprocity of function, other cells taking up the functions of those which were destroyed.

Certain parts of the brain are associated with definite functions; thus, there are areas which influence or control speech and motion of parts as the arm or leg, and there are large areas known as the silent areas whose function we do not know. All activity of the central nervous system, however expressed, is due to cell activity and is associated with consumption of cell material which is renewed in periods of repose and sleep. Fig. 13 shows a nerve cell of a sparrow at the end of a day's activity and the same after the repose of a night.

Diseases of the nervous system have a special interest in that they so often interfere with man in his relations with his fellows. In diseases of other organs the disturbances set up concern the individual only. Thus, others need not be disturbed save by the demands made on their sympathies by an individual with a cold in the head or a cancer of the stomach. Disease of the nervous system is another affair, instead of those reactions and expressions of activity to which we are accustomed and to which society is adjusted, the reactions and activities are unusual and the individual in consequence does not fit into the social state and is said to be anti-social. There are all possible grades of this, from mere unpleasantness in the social relations with such an individual, to states in which he is dangerous to society and must be isolated from it. Insanity is an extreme case. There is no disease signified in the expression, but it is merely a legal term to designate those individuals whose actions are opposed to the social state and who are not responsible for them. In insanity there is falsity in impressions, in conceptions, in judgment, a defective power of will and an uncontrollable violence of emotion. The individual is prevented from thinking the thoughts or feeling the feelings and doing the duties of the social body in the community in which he lives. The insane are out of harmony with their social environment, but not necessarily in opposition to it.

There is no very sharp line between insanity and criminality. The criminal is in direct antagonism to the laws of social life. An insane person may cause the same injury to society as a criminal, but his actions are not voluntary, whereas the criminal is one who can control his actions, but does not. Mentally degenerated persons, however, can be both insane and criminal. Whatever the state of society, this reprobates the actions of one opposed to it; in a society in which it were usual to appropriate the possessions of others or to devour unpleasant or useless relatives, virtue and lack of appetite would be reprobated as unsocial.

The symptoms of insanity or the manner in which the defective action of the brain expresses itself and the various underlying pathological changes vary, and by combining these it has been possible to subdivide insanity into a number of distinct forms. There are both intrinsic and extrinsic causes of insanity. The intrinsic are the structural differences in the brain as compared with the normal or usual, whether these are due to imperfection in development or to defective heredity or to the injury of disease; the extrinsic causes are those which come from without and bring the intrinsic into activity. Syphilis is a frequent cause of insanity, and probably the only cause of the condition known as general paralysis of the insane, acting by means of the injury which it produces in the cortex of the brain. The abuse of alcohol is another fertile cause, but the changes produced in this are not so obvious as in the case of syphilis. Tumors of the brain are not infrequently a cause, and the same is true of infections, even those not located in the brain. How susceptible the brain is to the effects of the toxines of the infectious diseases is shown in the frequency of delirium in these diseases. There is an interesting relation between this and alcoholism. Alcohol abuse may produce injury, but not sufficient to manifest itself under ordinary conditions; when, however, the action of toxic substance is superadded to the effect of the alcohol the delirium of fever is more marked.

Probably of greater importance than the acquired pathological conditions of the brain in producing insanity is a congenital condition in which the nervous system is defective. The most fertile cause of insanity lies in the inheritance; by this it must not be understood that insane parents produce insane offsprings, but that conditions inherited from immediate or remote ancestors appear in a diminished resistance of the nervous system which is sooner or later expressed as insanity. Given such a defective nervous system, extrinsic conditions which would have no effect on another individual or would be felt in different ways may produce insanity. In these cases occupation plays a great role. The excitement and privations of war especially in the tropics and the ennui of camps leads to insanity in soldiers; occupations such as that of the baker in which there is loss of sleep and the mental strain of students can all act in the same way. A woman who gives no sign of nervous defect may become insane under the strain of pregnancy.

Although insanity is determined by the social relations of man, that part of the social organization which is termed Society, and which has been developed by the idle as a diverting game, is a fertile source of nervous disease and even of insanity, affecting particularly females. The strenuosity of the life, the nervous excitement alternating with ennui, the lack and improper times of sleep, the lack of rest and particularly of restful occupation, the not infrequent use of alcohol in injurious amounts, are all factors calculated to make a defect operative. The so-called "coming out" of young girls is an important element in the game, and their headlong plunge into such a life at a period under any conditions full of danger to the nervous system is especially to be reprobated. If we consider the influence of the game in other respects as conducing to lack of moral sense, to alcoholic abuse (for without the seeming stimulation, but which is really the blunting of impressions which alcohol brings, the game would not be possible), to discontent, to mental enfeeblement, it is all bad. Curiously enough the game is one which in all periods has been played by the idle, but its evil influence is greater now than before when it was the game of royalty chiefly, because there are now more people living from the work of others.

The unusual mental action of the insane not infrequently expresses itself by suicide. The analysis of three hundred deaths from suicide showed pathological changes in the brain in forty-three per cent, and when we think that mental disturbances are very often without recognizable anatomical changes after death, the percentage is very large. In another analysis of one hundred and twenty-four suicides forty-four of these were mentally affected to various degrees. Five of the men and seven women were epileptics, in ten of the families there was hysteria, twenty-four of the men and four of the women were chronic alcoholics.

It is extremely difficult at the present time to say whether insanity is increasing. Statistics in all lands giving the numbers committed to insane hospitals show on their face a great increase, but so many factors enter into these statistics that their value is uncertain. There is now an ever-increasing provision for the care of the insane. Owing to the recognition of insanity as a part of nervous disease and its separation from criminality there is no longer the same attempt to conceal it as was formerly the case, and hospitals for the insane are no longer associated with ideas of Bedlam. It is generally believed that modern conditions in the hurry and excitement of life, and the extreme social differences, the greater urban life, the greater extension of factory life, all tend to an increase in insanity, but there is no absolute proof that this is true. We know very little about insanity in the Middle Ages, but the conditions then were not conducive to a quiet life. There prevailed then as now excess and want, luxury and poverty, enjoyment and deprivations, balls and dinner parties and other features of the social game. There were factions in the cities, public executions, not infrequent sieges, scenes of horror, epidemics, famines, and all these combined with religious superstition and the often unjust and cruel laws should have been factors for insanity. There were actual epidemics of insanity affecting masses of the population, as shown in the children's crusade, the Jewish massacres and the dancing mania in the Rhine provinces. Where civilization seems to be the highest, statistics show the most insane, but this most probably depends upon better recognition of the condition and better provision for asylum care.

The so-called functional diseases have a close relation with diseases of the nervous system, for they chiefly concern the reactions of nerve tissue. Disease expressing itself in disturbance of function only, does not seem to fit in with the conceptions of disease which have been expressed, nor can we imagine a disturbance of function which does not depend upon a change of material. Living matter does not differ intrinsically from any other sort of matter; like other matter its reactions depend upon its composition structure[1] and the character of the action exerted upon it. By functional disease there is expressed merely that no anatomical or chemical change is discoverable in the material which gives the unusual reaction. The further our researches into the nature of disease extend, particularly the researches into the physiology and chemistry of disease, the smaller is the area of functional disease. In functional disease there may be either vague discomfort or actual pain under conditions when usually such would not be experienced, and on examination no condition is found which in the vast majority of cases would alone give rise to that impression on the nervous system which is interpreted as pain. In the production of the sensations of disease there can be change at any place along the line, in the sense organs, in the conducting paths or in the central organ. Thus there may be false visual impressions which may be due to changes in the retina or in the optic nerve or in the brain matter to which the nerve is distributed. It is perfectly possible that substances of an unusual character or an excess or deficiency of usual substances in the fluids around brain cells may so change them that such unusual reactions appear. There may be, of course, very marked individual susceptibility, which may be congenital or acquired. The perception of every stimulus involves activity of the nerve cells, and it is possible that the constant repetition of stimuli of an ordinary character may produce sufficient change to give rise to unusual reactions, and this particularly when there is lack of the restoration which repose and sleep bring. We know into what a condition one's nervous system may be thrown by the incessant noise attending the erection of a building in the vicinity of one's house or the pounding of a plumber working within the house, this being accentuated in the latter case by the thought of impending financial disaster. Even the confused and disagreeable sound due to the clatter of high-pitched women's voices at teas and receptions may, when frequently repeated, be productive of changes in the nerve cells sufficiently marked to give rise to the unusual reactions which are evidence of disease.

In the condition known as neurasthenia, which is often taken as a type of a functional disease, the basal and intrinsic cause is activity of the nervous system with the using up of material which is not compensated for by the renewal which comes in repose and sleep. Neurasthenia is one of the common conditions of our civilization, found among children and adults, the poor and rich, the idle and the factory worker; it is rife in the scholastic professions and among those who earn their living by brain work. It seems to be more common in the upper classes and particularly in the women, but this is because these are more subject to medical care and the condition is more in evidence. There are all sorts of symptoms attached to the condition, for the unusual mental action can be variously expressed. The cerebral form has been thus described by a well-known medical writer: "One of the most characteristic features of cerebral neurasthenia is a weary brain. The sensation is familiar enough to any fagged man, especially if he fall short of sleep. Impressions seem to go half into one's head and there sink into a woolly bed and die. Voices sound far off, the lines of a book run into one another and the meaning of them passes unperceived. Doors bang and windows rattle as they never did before; if a shoestring breaks, an imprecation is upon the lips. Business matters are in a conspiracy to go wrong. Letters are left unopened partly from want of will, partly from a senseless dread lest they contain bad news. At night the patient tosses on his bed possessed by all the cares which blacken with darkness. Headache is common, loss of memory is distressing, and in severe cases it is wider and deeper than mere inattention can explain. There is often the torture of acute hearing, or an inability to suppress attention; the hater of clocks and crowing cocks is a neurasthenic." The disease is especially common in the women players of the social game, and its unhappy victims too often seek relief from the nervous irritability which is a common early symptom in still greater nervous excitement. It is a sad commentary on our civilization that one of the means of treatment for these persons which has been found efficacious is to supply them with some restful household occupation such as knitting or plain sewing, and there are institutions which combine refuge from social activities, often called duties, with simple occupation.

FOOTNOTE: [1] By structure as used in this wide sense, there must be understood not merely the anatomical structure, which is revealed by the dissecting knife and microscope, but molecular structure, or the manner in which elements are arranged to form the molecule, as well.



CHAPTER XII

THE RAPID DEVELOPMENT OF MEDICINE IN THE LAST FIFTY YEARS.—THE INFLUENCE OF DARWIN.—PREVENTIVE MEDICINE.—THE DISSEMINATION OF MEDICAL KNOWLEDGE.—THE DEVELOPMENT OF CONDITIONS IN RECENT YEARS WHICH ACT AS FACTORS OF DISEASE.—FACTORY LIFE.—URBAN LIFE.—THE INCREASE OF COMMUNICATION BETWEEN PEOPLES.—THE INTRODUCTION OF PLANT PARASITES.—THE INCREASE IN ASYLUM LIFE.—INFANT MORTALITY.—WEALTH AND POVERTY AS FACTORS IN DISEASE.

Certain conditions have arisen in the past fifty years which have profoundly affected the thoughts, the beliefs and the activities of man. Within this period what is generally known as Darwinism, including under this evolution, has developed. Unlike theories which came from philosophical speculation only, the theory of evolution was one which could be subjected to observation and experiment. It freed man's mind from dogmas, it stimulated the imagination, it enlarged the territory in which it seemed possible to extend knowledge by the methods of science, and has resulted in an enormous increase of knowledge. This has been more striking in medical science than elsewhere, and in this of more far-reaching influence. Evolution coincided with another important development. History shows that all great periods of civilization have at their back sources of energy. In the civilizations of the past such sources of energy have come from the enslavement of conquered peoples or from commerce, or more direct forms of robbery, which have enabled a favored class to appropriate for its purposes the results of the work of others. While these sources have not been absent in the development of our civilization, the great source of energy has come from the rapid, and usually wasteful and reckless, utilization of the stored energy of the earth. The almost incredible advance in medical and other forms of scientific knowledge and the utilization of this knowledge is largely due to the greater forces which we have become possessed of.

Disease plays such a large part in the life of man and is so closely related to all of his activities that the changes in this period must have exerted an influence on disease. We have already seen that within the period we have obtained knowledge of the causes of disease and the conditions under which these causes became operative. The mystery which formerly enveloped disease is gone; disease is recognized as due to conditions which for the most part are within the control of man, and like gravity and chemical attraction it follows the operation of definite laws. There has been developed within the period what is known as preventive medicine, which aims rather at prevention than cure, and the resources of prevention are capable of much greater extension.

Have there been new conditions developed within the period, or an increase of existing conditions which can be regarded as disease factors and which counterbalance the results which have come from the knowledge of prevention and cure? There has been an increase of certain factors of immense importance in the extension of disease. These are:

1. The increase in industrialism, involving as this does an increase in factory life. In many ways this is a factor in disease. (a) By favoring the extension of infection, particularly in such diseases as tuberculosis. (b) The life indoors, and frequently with the combination of insufficient air and space, produces a condition of malnutrition and deficient general resistance. (c) The family life is interfered with by the mothers, whose primary duty is the care of home and children, working in factories, and the too frequent conversion of the house into a factory. (d) The influence of factory life is towards a loss of moral stamina rendering more easy of operation the conditions of alcoholism and general immorality. How great has been this increase in industrialism, fostered as it has been by conditions both natural and artificially created by unwise legislation, is shown in the figures from the last census. The number of factory operatives increased forty per cent between 1899 and 1909 and the total population of the country in the period between 1900 and 1910 increased twenty per cent. It is probable that the future will see an extension rather than a diminution of mass labor.

2. The increase in urban life is as conspicuous as the increase in industrialism. In 1880, twenty-nine and five-tenths per cent of the population was urban and seventy and five-tenths per cent was rural; in 1910, forty-six and three-tenths per cent was urban and fifty-three and seven-tenths was rural, the increase being most marked in cities of over five hundred thousand inhabitants. Of the total increase in population between 1900 and 1910, seven-tenths per cent was in the cities and three-tenths per cent in the country. City life in itself is not necessarily unhealthy and there are many advantages associated with it. The conditions which have chiefly fostered it are the immigration of people who are accustomed to community life, the increase in factory life and the increased number of people of wealth who seek the advantages which the city gives them. The city has always been the favored playground for the social game. The unhealthy conditions of city life are due to the crowding, the more uncertain means of livelihood, the greater influence of vice and alcoholism. Prostitution and the sexual diseases are almost the prerogatives of the cities.

3. All means of transportation have increased and communication between peoples has become more extended and more rapid. In the past isolation was one of the safeguards of the people against disease. With the increase and greater rapidity of communication there is a tendency not only to loss of individuality in nations as expressed in dress, customs, traditions and beliefs, but many diseases are no longer so strictly local as formerly—pellagra, for example. Only those diseases which are transmitted by insects which have a strictly local habitat remain endemic, although the region of endemic prevalence may become greatly extended, as is seen in the distribution of sleeping sickness. Diseases of plants and of animals have become disseminated. Any plants desirable for economic use or for beauty of foliage and flower become generally distributed, their parasites are removed from the regions where harmonious parasitic inter-relations have been established, and in new regions the parasites may not find the former restrictions to their growth. There have been many examples of this, such as the ravages of the brown-tail and gypsy moths which were introduced into New England and of the San Jose scale which was introduced into California. There have been many other examples of the almost incredible power of multiplication of an animal or plant when taken into a new environment, removed from conditions which held it in check, as the introduction of the mongoose into Jamaica, the rabbit into Australia, the thistle into New South Wales and the water-plant chara into England.

It is very difficult to say, but it seems as though there is an increasing unevenness in the distribution of wealth, an increase in the number of persons who live at the expense of the laboring class. Mass labor, effective though it be, makes it easier to divert the proceeds of labor from the laborers. The evidence of this is seen in the increase in number and the prosperity of those pursuits which purvey to luxury, as the automobile industry and the florists' trade and the greatly increased scope and activity of the social game. On the other hand, there is an increase in the number of people who are to a greater or less extent dependent upon extraneous aid, evinced among other ways by the increase in the asylum populations. Both these conditions, wealth and poverty, are important disease factors. Tuberculosis is now a disease of the proletariat chiefly. The measures both of prevention and cure can be and are carried out by the well-to-do, but the disease must remain where there are the conditions of the slums. Of all the conditions favoring infant mortality poverty comes first. In Erfurt, a small city of Germany, of one thousand infants born in each of the different classes, there died of the illegitimate children three hundren and fifty-two; of those of the laboring class, three hundred and five; of those in the medium station (official class largely), one hundred and seventy-three; of those in higher station, eighty-nine. The same relation of infant mortality to poverty becomes apparent when estimated in other ways. In Berlin, with an average infant mortality of one hundred and ninety-six per thousand, the deaths in the best districts of the city were fifty-two and in the poorer quarters four hundred and twenty. The effect of poverty is seen particularly in the bottle-fed infants; with natural nursing the child of poverty has almost as good a chance as the child of wealth. From reasons which are almost self-evident, the mortality in illegitimate infants is almost double that of the legitimate. The greater infant mortality in poverty is due to the more numerous children preventing individual care, the separation of the mother from the nursing child in consequence of the demand made upon her earning capacity, and the decline in breast nursing. Wealth is on the whole more advantageous from the narrow point of view of disease than is poverty, but if we regard its influence on the race its advantages are not so evident. Nothing can be worse for a race than that it should die out, and wealthy families have never reproduced themselves. Conditions always tending to destruction are a necessary part of the environment of poverty; wealth voluntarily creates these conditions, and chiefly by the pernicious influence of its amusements on the young.

A new and in many respects a nobler conception of medicine has been developed. Formerly medical practice was almost exclusively a personal service to the sick individual, and measures looking toward the general relief of disease and its prevention received scanty consideration. The idea of a wider service to the city, to the state, to the nation, to humanity rather than the personal service to the individual, is becoming dominant in medicine. This is seen in the establishment of laboratories by boards of health in cities and states in which knowledge obtained by exact investigations can be made of direct service to the people; in the medical inspection of schools and factories; in promulgating laws directed against conditions which affect health, in the extension of hospitals, and in divers other ways. The idea of public service and of returning to the people in an effective way some of the results of their labor also underlies the large donations which have been given for the creation of special laboratories and institutes in which, through research, greater knowledge of disease may be obtained and made available. The researches which have been made on the nutrition of man and the nutritive value of different foods are of great importance, and this knowledge has not yet begun to be applied as it should be.

There seems to be a balance maintained between the restriction of disease by prevention and the increased influence of social conditions which are in themselves factors of disease. Preventive medicine seems to have made possible, by restricting their harmful influence, the increase in industrialism, in urban life, and in the intercommunications of peoples. The most important aid in the future to the influence of preventive medicine must be the education of the people so that the conditions of disease, the intrinsic and the extrinsic causes and the manner in which these act, shall all become a part of general knowledge, and the sympathy of the people with health legislation and their active assistance in carrying out measures of prevention may be obtained. The effect of social conditions on disease must become more generally recognized.



GLOSSARY

ATROPHY—A condition of imperfect nutrition producing diminution in size and loss of function of parts.

BERTILLON—A French anthropologist who devised a system of measurements of the human body for purposes of identification.

BLOOD-PLASMA—The fluid of the blood.

CELL—The unit of living matter. Living things may be unicellular or composed of a multitude of cells which are interdependent. The general mass of material forming the cell is termed cytoplasm. In this there is a differentiated area termed nucleus which governs the multiplication of cells. In the nucleus is a material termed chromatin which bears the factors of heredity.

CHEMOTROPISM—The influence of chemical substances in directing the movement of organisms.

EXUDATE—The material which passes from the blood into an injured part and causes the swelling.

FIBRIN—The gelatinous material formed in the blood when it clots.

HAEMOGLOBIN—A substance which gives the red color to the blood; by means of its ready combination with the oxygen of the air in the lungs this necessary element is carried to all parts of the body.

INFLAMMATION—Literally a "burning"; the changes which take place in a part after injury.

LYMPH—The fluid which is contained in the lymphatic vessels—nodes. Circumscribed masses of cells connected with the lymphatic vessels.

OSMOSIS—The process of diffusion between fluids of different molecular pressures.

SPORE FORMATION—A mode of reproduction in lower forms of life by which resistant bodies, spores, are formed. These have many analogies with the seed of higher plants.

SYMBIOSIS—A mutual adaptation between parasite and host.

TRANSUDATION—The normal interchange of fluid between the blood and the tissue fluids. The material interchanged is the transudate.

TROPISM—The influence of forces which direct the movement of cells.

ULTRA-MICROSCOPE—A form of microscope which by means of oblique illumination renders visible objects so small as to be invisible with the ordinary microscope.

VIRUS—A substance either living or formed by living things which may cause disease.



INDEX

Amoeba, 13

Anthrax, 109

Antitoxin, 154

Bacteria, 116 adaptation in, 123 aerobic, 122 anaerobic, 122 artificial cultivation of, 119 distribution in nature, 121 growth and reproduction, 118 mode of action in disease, 144 size, 117 spore formation, 118 substances affecting growth of, 123 toxin production by, 144 variations in, 123

Blood, 35 circulation of, 33, 80 vessels, 32

Body, 22 defenses of, 146 organs of, 28 reserve force of, 50 surfaces of, 22

Brain, 31

Cerebro-spinal meningitis, 188

Chemotropism, 93

Cretinism, 37

Darwinism, 240

Death, 57 decomposition after, 51 rigor after, 60 signs of, 59

Disease, 1 action of poisons, 44 acute and chronic, 219 industrialism as factor in, 243 lesions of, 46 superstitions concerning, 10 urban life as factor in, 244 wealth and poverty as factors in, 246

Ductless glands, 37

Embryo, 77

Epilepsy, 209

Eugenics, 215

Foetus, 32 infection of, 200

Foot and Mouth Disease, 129

Glands, 22

Growth, 62

Heart, 33, 221 disease of, 223

Heliotropism, 93

Heredity, 197 influence of alcohol, 206 of insanity, 209 variations and imitations, 204

Hookworm disease, 179

Immunity, 148 theories of, 149 natural, 150

Infection, 135 from external surface, 136 from genito-urinary surface, 137 from lungs, 138 from mouth, 138 from stomach and intestines, 139 from wounds, 141 in children, 195 in wild animals, 191 latent, 166 mixed, 160 racial susceptibility to, 191 resistance to, 143 by air, 170 by insects, 171

Infectious diseases, 97 carriers of, 185 comparison with fermentation, 108 epidemics of, 98 endemic, epidemic and sporadic forms, 188 modes of transmission, 161

Inflammation, 80 acute and chronic, 95

Injury, 54-74

Insanity, 231 causes of, 232 question of increase, 235

Lesion, 17

Leucocytes, 36 migration of, 92

Living matter, 10

Malaria, 175 role of mosquito in transmitting, 178

Malformations, 211 heredity of, 215

Maternal impressions, 212

Nervous system, 228 disease of, 230 effect of social life on, 233

Neurasthenia, 238

Old age, 51 atrophy in, 51 blood vessels in, 54 causes of death in, 56 in animals and plants, 55 mental activity in, 53

Osmosis, 91

Opsonius, 153

Ovum, 201 fertilization of, 198 infection of, 199

Phagocytosis, 86

Plague, 182 transmission by animals, 183

Plasmodium Malariae, 175

Preventive medicine, 242

Protozoa, 124 distribution in nature, 125 mode of growth, 125 sexual differentiation, 125 spore formation, 125

Polyomyelitis, 190

Repair, 46 conditions influencing, 47

Scar, 49

Skin, 21

Sleeping sickness, 173

Smallpox, 187

Spontaneous generation, 106

Sunburn, 83

Syphilis, 193

Tetanus, 142

Thymus, 52

Thyroid, 37

Tonsils, 52

Toxins, 144

Tropisms, 93

Trypanosomes, 172

Tuberculosis, 163 infection by sputum, 169 modes of extension, 163

Tumors, 64 benign and malignant, 69 cells of, 66 color, size and shape, 65 growth of, 65 importance of, 77 origin of, 66 question of increase, 69 theories of cause, 71 treatment of, 77

Typhoid fever, 170

Ultra-microscopic organisms, 128

Virus, 128

Yellow fever, 178

THE END