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Sir Dyce Duckworth152asks: Why are some remarkably young for their age and others old? It cannot all be explained by anything in the individual life or habits. Perhaps it is in part because the ancestors lived a hard life. We want the degree of inherent vitality proper to each individual patient. This would be as important for prognosis in pneumonia as are the hæmic leucocytes. Arterial hardening may be local only, for example, radial. There are two kinds of arterial degeneration, namely, the brittle and the tough, the former more liable to cause hemorrhages and fatty degeneration.
Very important is the discovery that the rigidity of calcified arteries is greatly increased immediately after death. The lime is present before, as disclosed by the X-rays, but it is like wet or unset mortar and only sets after death under the influence of carbon dioxide and the rapidly diminishing alkalinity of the blood. The so-called air in the arteries after death is chiefly carbon dioxide and this explains why such arteries do not rupture so frequently as we might expect. Premature deathof parts of the body is constantly occurring, for example, baldness, teeth. One may be vulnerable to one and another to another type of injury or bacilli. Syphilis is mainly a conjoined trait or infection and greatly predisposes to tubercle. Indeed, a syphilitic patient may be regarded as a prematurely aged one in spite of a good constitution, because there is always the possibility of sequels or parasyphilis, general paralysis, etc.
Among the early mental signs of interstitial nephritis is an explosive temper. Fits of hilarity and weeping may alternate (first pointed out by Clifford Allbutt). The costal cartilages ossify generally before the sixth decade and this is often premature. A hobby may no longer avail to preserve mental activity, and “the golf ball to-day is not seldom one of the beneficent agencies for this purpose.” Cirrhosis of the liver is longer averted in the patrician than in the plebeian because the laborer becomes senile sooner than others owing to his life of strain in all weathers. In arthritis, the nodosity of joints, especially in the fingers, in the form ofHeberden’snodes, is thought by some an indication of longevity. They are often found in those who have few classical symptoms of gout and few reach eighty or ninety without these trophic changes. Dupuytren’s contractures and the camptodactylia of Landouzy, or incurved little finger, are among indications of a gouty habit and are not truly rheumatic lesions. Indolence of the bladder does not imply prostatic symptoms. Very common are widespread catarrhal disturbances, as for example, tussis senilis, with much flux of mucus, often rich in sodium chloride. Fits of sneezing, also of hiccough and even gaping, are frequent.
The main treatment for early senility is physiological righteousness (Sir A. Clark). We must especially know the degree of vigor, of vitality, and specific habit of body. We must pay attention to the degree of blood pressureand early indications of renal inadequacy, orthostatic albuminuria, the tendency to epistaxis, and maintain as our keynote moderation in all things. The best idea is that of universal service which would bring all the world together on a high plane. The author refers with a good deal of skepticism to Metchnikoff’s Bulgarian bacillus but mentions Saundby’s book with great praise.
Robert Saundby, M.D.,153has given us what is, to date, the best handbook, both for practitioners and for old people who are intelligently interested in conserving their life and strength, on the common infirmities and care of the aged, exclusive, for the most part, of nervous and psychic symptoms. He first describes normal old age, then its diseases in successive chapters—diathetic infections, and those of the circulatory, respiratory, digestive, and genito-urinal systems. Perhaps most practical are the dietaries he gives for different stages of old age and different diatheses. He commands a wide knowledge of Continental literature on the subjects he treats. He has a just sense of the dangers of stressing specifics from, for example, Pythagoras, who thought there was a special virtue for longevity in honey; Bacon, in sweating; Harvey, in avoiding acids; down to Blanchard, in sal volatile; blood drinking cures, olive oil, licorice, etc. He believes that Metchnikoff’s panacea and the undue stress laid by Lorand on thyroid therapy have not escaped the dangers of undue focalization. He allows a very wide latitude not only in regimen and exercise but food, condiments, and even stimulants, for the aged.
No one can read his account of the changes that take place in each part and organ of the body as they are successively described and the very different treatments that each needs as it goes wrong, without a sense ofthe fatality with which these vast cohorts of life-quelling symptoms advance and, in view of the many strategies the lethal processes make use of to undermine the fortress of life, without experiencing a profound sense of the hopelessness of watching out in so many directions and realizing that, as differentiation proceeds in the different organs, any regimen helpful to one would almost certainly be harmful to others.
Arnold Lorand, an Australian physician,154bases his work on the principle that man does not die but kills himself. He does not philosophize but tells us that while it is impossible to create a young man out of an old one, it is quite within the bounds of possibility to prolong our youthfulness by ten or twenty years. In other words, we need no longer grow old at forty or fifty. We may live on to the age of 90 or 100 years instead of dying at 60 or 70. Old age is just as amenable to treatment as chronic diseases. He has great faith in the present possibilities and still larger hopes for the future of serum therapy, for to him life is most of all connected with the glands. He discourses upon the hygiene of throat, lungs, heart, kidney, liver, stomach, bowels, reproductive organs, and the rest with a bewildering volume of details but good perspective, and the reader is again disheartened to find that the treatment prescribed for one organ is deleterious to another. Indeed, Lorand’s somewhat encyclopedic and undigested data, despite the common sense and practical spirit in which they are presented, bear, on the whole, less upon old age itself than upon general hygiene at all stages of life, so that his title is to that extent a misnomer.
He sums up his practical conclusions in the form of twelve commandments, which are, briefly, to keep in the open and take plenty of exercise; eat according torule; bathe and move the bowels daily; wear porous underclothes; early to bed and rise; sleep where it is dark and quiet; rest one day each week; avoid emotional strain; get married; be temperate in the use of alcohol, tobacco, tea, and coffee; and avoid over-eating and -heating.
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T. D. Crothers, M.D.,155thinks we have not sufficiently considered the abilities of old age from a medico-legal standpoint. He also thinks that if we do not live to be 100 something is wrong with us or our ancestors. We all carry a large reserve that many die without drawing upon, and this reserve is especially available in old age (he develops this point psychologically). Many old people with melancholia, hallucinations, and the characteristic physical defects of old age have, nevertheless, a higher kind of sanity to which their juniors do an injustice by the tests they propose. They are quite capable of making wills and otherwise deciding the large questions that come before them and often do so from a broader point of view than younger men. It is possible, then, to rise to a higher level, to a kind of graduate school of life, to use the unused, etc. Again, the varied experiences of long life give mobility of mood up and down what Adler calls the life line, so that the old have a larger assortment of viewpoints and even moods, to say nothing of greater ups and downs in horizon and standpoint generally.
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C. G. Stockton, M.D.,156suggests family records and pride to avoid mixing good stock with that which decays early. He recognizes the great contributions of the dentistand oculist, deplores the neglect of old age, and insists that the aged do respond to treatment very readily. He also deplores the attitude of many physicians who discourage resolute methods of curing defects and warding off evils because the patient is old. He stresses the value of emunctory procedures both within and without.
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Dr. W. G. Thompson157deplores the fact that physicians have given so little attention to old age and that the medical literature upon the subject is so meager. The very old have survived all corroborative evidence as to their age, their failing memories confuse tradition and fact, and they come very often to take pride in their age and so add to it. The author’s study is based on the census statistics of 1910, which record, from 90–94 years, 6,175 deaths; from 95–99, 1,427; 100 years and over, 372. The respiratory diseases as a group took first rank as the cause of death; organic heart disease, apoplexy, and Bright’s disease occurring in frequency in the order mentioned. Among diseases of the digestive system enteritis outranked all others.
As age advances and its activities and diversions become less and less, locomotion is reduced, along with acuteness of sight and hearing, and the pleasures of the table remain the only gratification of a monotonous existence. Very many accustom themselves to the habitual use of laxatives to counteract the effects of overeating, and often we have obstructions, especially of the rectum or colon, that may become fatal. This, however, is more often seen in those who eat too little and become perhaps atrophic and marasmic. These people become careless of matters of the toilet and obstructions often cause death. Apoplexy is relatively rareamong centenarians and carcinoma also declines as a cause of death after the ninetieth year. Indeed, the disease that does not develop until after the ninetieth year can scarcely be due to hereditary factors and the infrequency of cancer in the later stages of life emphasizes the constitutional resistance to extraneous influences that the majority of centenarians possess in a high degree. Acute and very quick or fatal pneumonia is not infrequent.
One very peculiar difficulty in treating old patients is their prejudice and obstinacy in matters of diet and hygiene; because they have lived so long they naturally think they know better than anyone else what is good for them and, with a certain irritability, resist interference. As a rule, they are relatively very susceptible to the action of drugs and two-thirds of the ordinary dosage for adults generally suffices. Very often the very aged suffer from the neglect of personal cleanliness. There are many diseases common from the sixth to the ninth decades of life that are very rare later, for example, tuberculosis. Suicide is very rare, the census of 1910 recording only one of a centenarian and nine among nonagenarians. The latter generally have a long-lived ancestry and many families are remarkable for this trait. But this is by no means essential. The aged often exhibit no predominant symptom of any one disease to which their death is attributable, and hence “senility” is so often given as the cause of death. Tranquillity, moderation, and regularity seem to be the chief factors in securing a long life and a peaceful death.
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M. L. Price, M.D.,158attacks Metchnikoff’s theory of old age by assuming that in addition to all toxins and inflammations there is always an old-age exhaustion ofa vital principle that he calls bioplasmine, that may, to be sure, be mainly caused by Metchnikoff’s agencies but is equally affected by effort, exposure, growth, and reproduction. He sagely predicts that the solution of the problem of old age, which he thinks is the central theme of all medicine in the sense in which he conceives it, because every disease brings senile phenomena to some part of the organism or to the whole of it, will be solved by biochemistry, although he admits that it may take many generations of investigation to achieve this final solution.
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George S. Keith, M.D.,159after a long life of practice, has grown suspicious of current methods. “I purge, I puke, I sweat ’em; and if they die I let ’em.” As to foods, he believes that the old should only eat when they are far hungrier than they usually are and leave off eating when they now habitually begin a meal. Appetite, which seems to give momentum to all the assimilative processes, is never utilized to its full extent. Sick animals often go off alone and succeed in recovering and he believes humans have the same instinct. He is, therefore, bitterly opposed to forced feeding, even for the insane, save under very exceptional conditions. The sick should generally be allowed to eat whatever they wish, perhaps in moderation, or to go entirely without food. Probably primitive man and all animals had to undergo occasional long fasts and this serves to tone up not only the nerves but the entire digestive system. Instinct is a far truer guide than doctors who interfere with it think. Once the fevered patient who reveled in dreams of cold was kept warm; now we know better.
This author has, thus, an almost implicit trust in the cravings and dislikes of the sick and would indulge themalmost to the limit, as the German hygienist, Sternberg, would do to a perhaps even greater degree. He is also a great believer in rubbing and massage. Hot water plays an important rôle, too, while he attaches very special value to licorice. Doctors are often too anxious to save patients from all pain, perhaps by the use of means that entail worse consequences. Pain has its place in nature and the doctor should also try to have the patient apply the cure of patience. Pain is nature’s cry for help, to which she often responds as she does not to other stimuli; and benign as is the rôle of anæsthesia, it should not blind us to the tonic effects pain often exercises. So sleeplessness may not be an unmixed evil in certain cases and sleep artificially induced is usually of poorer and less restorative quality. He has found fixating, spontaneous retinal phosphenes a good soporific method. He believes that very many diseases would cure themselves if the patient could be induced to simply rest and starve. Although he is not a homeopathist, he nevertheless believes that dosages of medicine are far too large. He insists that old and experienced physicians ought to, and that the best do, learn a great deal from experience in keeping themselves well, and that every physician should accumulate thus a store of knowledge based on self-observation, and may well, with profit, always be mildly experimenting upon himself. As age advances he would regulate diet and treatment largely to the avoidance of accumulation of uric acid in the system. He found great reinforcement for himself in making a breakfast of coffee only, etc.
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J. Madison Taylor160notes the paucity of literature on this subject that he found in trying to read up on it and thinks it warrants far more attention. The foundationsfor longevity are laid in the first few months of life and bottle-fed babies are shorter-lived and much less likely to reach old age. Those who spend their infancy and childhood, too, in large centers are less long-lived than those brought up in the country. A serene mental view and capacity for deliberate enjoyment of whatever betides he places first of all and advises self-education in serenity. The less we eat and the less variety, the longer we live, and on this the author lays great stress. We must put aside, as we advance, some articles of diet of which we are fond.
He believes dentists have greatly interfered with longevity because man was meant to be more or less toothless and thus to be reduced in old age to childish diet and fluids, while the dentists enable us to eat anything we ever did, which is against Nature. He speaks of fads and their dangers, for example, one old lady thought she prolonged her life by eating a great deal of salt. The indolence and indifference of age is a great difficulty. If one persists in trying to keep up indefinitely, the results are often amazing. Medical aid should be sought more constantly for lesser ills. Man is like an old horse—if he once gets thoroughly out of condition it is hard to bring him back. G. M. Gould has believed that unfit glasses have shortened the lives of many eminent men. But open air is asine qua nonalways.
Tessier gives a clinical picture of approaching death—(1) heart and blood vessels, (2) lungs, (3) kidneys, (4) digestive organs, (5) the brain. Most agree that the heart plays the chief rôle in ending life and many used to think that nearly all old-age diseases were from arterial hardening. But this was doubtless much exaggerated. Old age is a progressive diminution of all functional activities. All clinicians recognize diatheses or a tendency toward disease and we can detect themin their incipiency now far more than formerly. Age diathesis means a lessened coefficient of resistance, quick exhaustion, and weak repair. The author devotes great attention to obesity, which shortens life, and he advocates various exercises of the extensor muscles, deep breathing, and thinks much can be done to tone up and increase the activity of the heart.
He thinks the effects of the menopause have been rather overestimated. Exhaustion, especially induced by emotions, fatigue, anger, grief, and fear, weaken the protective powers of the mysterious agents of immunity. The mind is very liable to become fixed upon some ailment and hyper-conscious, particularly near the menopause, and this is due to failure of the organism to offer the same degree of resistance to toxins and to a general lessening of functional activity.
He thinks we can postpone old age by the following agencies. We should develop, not discourage, bodily exercise for without it there is a slow retrogressive change. The more nearly the diet is reduced to bread, milk and fruit, the longer the person will live and enjoy good health. Some can go for long intervals without feeding though more thrive on small quantities taken frequently. He condemns all purgatives and would regulate by salads, nuts, fruit, and thinks the best drink is buttermilk, which has salutary effects on both bowels and kidneys. Next comes koumyss. Fluids are best taken in abundance, but if the heart is weak they should be avoided before exercise, for this increases the cardiac strain. If the skin is dry, he advocates dry rubs rather than cold baths and olive oil occasionally, of which he says it is amazing how much the skin will absorb. He speaks emphatically of the dangers of chills and of the trend of all tissues to harden, stiffen, or lose their elasticity. Tissues about the neck are particularly prone to lose vigor. Regulated movements of the neck and uppertruncal muscles often improve hearing, vision, cerebration, and sleep, and the same is true of friction. Most digestive disturbances, even those of early middle life, are due to relaxation of the supporting tissues of the great organs in the abdomen. This dilation is found in at least 60 per cent of adults, and it produces a long train of alterations. The kidneys are supported mainly by their blood vessels, so that if they sag their circulation is impaired, and this kind of ptosis is very common. Hence faulty attitudes are very important for all visceral ptoses, while he finds much to commend in the use of abdominal corsets, even for fleshy men. Elasticity of the ribs should receive attention and the author prides himself on exercises that increase the elasticity of the basal tissues which sclerosis is prone to assail. The capacities of individuals for exercise in the open air can generally lessen the need of medical supervision. With old people, the extensors should receive more, and the flexors, less attention and there should be sufficient stretching, torsion, etc.
As to the senile heart, it is generally assumed that the old should do no more than they are inclined to do and perhaps even lead a vegetable existence. But he believes that disinclination to movement means and makes under-oxidization and causes decay and he is severe on what he calls senile laziness. The healthier and happier old people are, the more active they become. The life of a hothouse plant is bad. Humphry found in most old people he examined little or no change in the arterial system. Allbutt says there are many old people in whom there is no arteriosclerosis. One common phenomenon of old age is the loss of vascular tone and defective lymph circulation. The bones lose weight and size and the walls of the shaft grow thin from within, especially toward the end of the bones and most near the head of the femur. Trunecek of Prague emitted the thesisthat certain salts can be introduced into the blood current that aid in dissolving the calcium phosphate found in the structure of sclerosed arteries. So he injected hypodermically a strong solution of sodium phosphate and magnesium phosphate, which are normally found in the blood serum but only in minute quantities. Others have introduced this by both bowel and mouth. Anything that aids oxidation of tissues helps.
In another article161Taylor says almost nothing that is new although there is much that would be practical to aging people. The machinery has become a little worn and weaker in spots but the bare surfaces have been abraded to meet each other so that there is less friction and racking of the joints. The body cells are less irritable. Degenerative diseases are very insidious. They increase in the following order—liver, digestion, apoplexy, nerves, heart, kidneys. One’s enjoyment of food is greater perhaps than discriminative. Many reminders of age are overcome by warming up. Skin emanations may be offensive. Traits of a mature mind are poise, deliberation, economy and the largest output of judgment, like the Roman senators or seniors. Irritability is common. Youth wants to know; age wants to be.
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C. A. Ewald,162one of the most eminent of German professors of biology, gives us one of the most condensed statements on the subject of old age. He begins by contrasting the intense life of Berlin, where the lecture was given, with the fact that all paths lead to the door of death, which is nearest in war. The antique conception of death was youth with a reversed torch; the medieval, a skeletal mower taking pleasure in hiswork. The martyr’s love of death and even the passion for Nirvana are probably more or less pathological. If we assume 15,000 million people on the earth and a death rate of 30 million per year, we should have 81,192 deaths daily; 3,425, hourly; and 57 every minute. The baobab tree of Cape Verde shows a life of 5,000 years. Some have ascribed 500 to the swan. But nearly all data of great age are discredited. Even that of Parr (152), who married with potence at 120, and all the rest, are doubted. But the length of life is increasing. In Sweden, of every 100 children of five at the beginning of the last century, 27 reached 70; at the end of the century, 48 did so. In Bavaria the number increased from 25 to 40; in Germany, in the last twenty years, it increased from 30 to 39, so that we all have a better chance of living long than we would have had if we had been born a hundred years earlier. The average length of life in 1870 in Germany was 37 years and has now increased to 42½. In France and England it is 46 and in Norway and Sweden, 52. Cures of tuberculosis in the last twenty years have reduced the percentage of its victims from 31 to 17 per 10,000, and vaccination has reduced the death per million from smallpox to 5; while in Russia, where it is not compulsory, it is 520.A priori, death does not seem necessary and yet for even protozoa division often involves something like a very rudimentary corpse so that investigators like Götte, Hertwig, and Verworn accept the tenet of Weismann, with some slight reservation, if the corpse is to be taken as the criterion of death.
Bees and the stork and other birds of passage kill or neglect their old, while in ancient German myth old men often slew themselves for the good of the community. Certain species eat their young rather than die themselves and even this is for the interest of the species. A certain wasp lays its eggs in the female plantand its young, when covered with its pollen, fly to a male plant to fertilize it, although this means their death. Thus death is a normative factor of development and to this extent Weismann is correct. Life has three periods. In the first there is an excess of energy and growth; then comes middle age with an equilibrium, while in old age the relation of these energies is reversed, so that the first and third stages contradict each other. But everywhere life is dependent on nutrition and all death, in whatever form, is due to its lack. So we have a kind of biological circulation and a kilogram of body substance evolves a different sum of total energy in each of these periods of life. The author gives us an interesting cut of the contraction of the vertebrae and their padding, which often in the old means ankylosis in the lower part of the spinal column.
He dissents from the Conklin theory of the abatement of metabolism as a cause of old age because he thinks this activity has a wide range of play at all stages of life, monthly and even daily. Nor does he accept without modification theSchilddrüse(thyroid) theory, although admitting that the endocrine glands play a very important function. Nor does he accept Von Hansemann’s view of altruistic nutritive disturbance, namely, that single cell groups are more or less reciprocally dependent upon others for their activity so that they in a sense work for each other. The physiological (that is, without outer stimulation) collapse of groups of cells is especially connected with the generative cells and their departure reacts upon the nutrition of the whole body and in a sense weakens it (the atrophy of age). The loss of the generative cells is physiological because they, in departing from the body, represent the growth of a new organism. Hansemann gives countless examples but they affect only the fact and not the kind or method of growing old, which is a progressive process, and westill are unable to answer the question why the generative cells in the ordinary process of life are so soon destroyed or why so few of them are devoted to this purpose.
The author sees much truth in Minot’s differentiation or cytomorphosis of cells, according to which differentiation, which causes growth, is also the cause of death. Minot himself says that the biologist can no more grasp the essence of death than he can that of life. Science does not know the difference between these two despite the impulsions of our causal instinct. Horsley thinks the condition for a green old age is the conservation of a sound thyroid. With its activity is, of course, connected that of other glands.
He says it might be assumed in a period during which a whole generation dies that the whole mass of putrefaction would cause infection. But in a half-dozen German cities very carefully investigated along this line it was found that those who lived in or near cemeteries were as long-lived as others and even those who drink water that is fed by drainage from well appointed graveyards are not infected; on the contrary, in several places this water is purer than elsewhere. There is only one exhumation in Germany for criminal purposes out of 600,000 corpses, but poison that might be detected by exhumation cannot, of course, be traced after cremation.
Instead of the remorse, anxiety for friends, dread and pain, the author, who says he has seen “many, many hundreds of deaths,” never saw one that was not unconscious. There are often, perhaps even for days, physical signs of great suffering but this is never felt; and the author advocates special death rooms in hospitals because it is so hard for onlookers that it is inhuman to allow patients to die in a ward with only a screen in front of the bed. The review of life by drowning people is a myth. It is the duty of the doctor to mitigateclosing pains by morphia and other means, provided these do not shorten but rather tend, as they should, to somewhat prolong life. Even in death by fire and torture the last stages are painless.
The Kamerlengo strikes the Pope on the forehead three times with a silver hammer and calls his name and, if he does not answer, says, “The Pope is really dead.” This is because hearing is supposed to be the last sense to die. But often after death the muscles contract spontaneously, even enough to move the body and this has made survivors believe their friends were alive. The muscles respond to electrical stimuli for hours. The pupil of beheaded people contracts to light. In Charlotte Corday’s head the eyes opened. Dr. Rousseau saw a case in which the heart occasionally beat twenty-nine hours after decapitation. Generally death proceeds from the heart and its last beat marks the entrance of death. Respiration, too, or the last breath is often the mark of death because the carbon dioxide is not removed; hence we say life is in the blood. Everyone at times wonders not only when he will die but how. And it is hard to live so as to avoid pathological death.
A French nobleman, François de Civille, in the time of Karl IX, appended to his monument the inscription: “Thrice dead, thrice buried, and by the grace of God, thrice revived.” The riddle meant that he woke first from his mother’s body at birth and twice in war was thought dead and placed among the dead. But the absence of personal consciousness is very unreliable because after long periods of lethargy many have rather suddenly revived. There never was a doctor present at an exhumation of a living man. Being buried alive is really a ghost that has no justification in civilized lands. This has nothing to do, of course, with simulation. Karl V simulated death in order to enjoy the spectacle of his funeral, as Juliet allowed herself to beburied. By contraction of the muscles of the neck and deep respiration the heart can be checked and the physiologist, Weber, nearly lost his life thus. Dr. Gosch tells of a Colonel Townsend who in the presence of Prof. Cheyne stopped his heart and breathing, the latter tested by a mirror, for half an hour until they were all convinced he was dead. But then he gradually came to, though he died eight hours later.
Herter and Rovighi tested lactic acid and its effects on fermentation of the large intestine and found negative results, so that we do not have an arcanum against death or old age in this sense, although insufficient excretion of toxins has much to do with it.
In his illuminating articles Professor Raymond Pearl, after showing the novelty of natural death and how even somatic cells now seem possibly immortal if separated from the metazoan body and that heredity is a prime determinant of the length of the span of life, says we must know more of the vagaries of germ plasm before society should assume to control it, although such control sooner or later will be necessary. The death rates for the four diseases that public health and sanitary activities have been most successful in treating, namely, (1) tuberculosis of the lungs, (2) typhoid fever, (3) diphtheria and croup, (4) dysentery, have been materially reduced in the last nineteen years. But if we compare four other causes of death, (1) bronchitis, (2) paralysis, (3) purulent infection and septicemia, (4) softening of the brain, on which health and sanitation have had little effect, it is found that the rate of mortality from these troubles has declined just as much, and probably a little more, in the same period of time, although the numbers in the latter group are far less. “Hence the declining death rate in and of itself does not mark the successful result of human effort.”
Recognizing the fact that the essential cells in ourbody are inherently capable under proper conditions of living indefinitely, the problem that confronts us is whether environment or heredity has most to do in determining the actual length of life. Pearl163concludes that the death rate of the earliest period of life is selective, eliminating the weak and leaving the strong, and that inheritance is “one of the strongest elements, if not indeed the dominating factor, in determining the duration of life of human beings.”
The duration of life in animals also depends on the total amount of metabolic activity or work and it has been proven that rats, at least, live longer under conditions so controlled that their activity is lessened, so that the greater the total work done or total energy output, the shorter is the duration of life andvice versa, work accelerating the aging process somewhat as rise of temperature does. Pearl says: “The manner in which the environmental forces (of sublethal intensity of course) chiefly act in determining the duration of life appears to be chiefly by changing the rate of metabolism in the individual. Furthermore, one would suggest, on this view, that what heredity does in relation to duration of life is chiefly to determine within fairly narrow limits the total energy output which the individual exhibits in its lifetime.” The duration of life of an animal stands in inverse relation to the total amount of its metabolic activity or, put in other words, to the work in the sense of theoretical mechanics that it as a machine does during its life. Or, to put it in another way, if the total activity of a unit of time is increased by some means other than increased temperature, the same result appears as if the increased activity is caused by increased temperature. Pearl thinks that Steinach’s experiments on the sexual glands, whatever their results for rejuvenation, do notprove “any really significant lengthening of the life span.” Nor does he think that Robertson’s experiments with tethelin from the pituitary gland, whatever its effects upon growth, show that it materially increases the length of life to a degree that has much significance statistically, so that inheritance remains a prime determinant of longevity.
We are all born in one way but die in many. By international agreement a mortality code has been developed with fourteen general classes comprising 180 distinct units. Pearl would supplement this very unsatisfactory classification by the following: (1) circulatory system and blood-forming organs, (2) respiratory system, (3) primary and secondary sex organs, (4) kidney and related excretory organs, (5) skeletal and muscular system, (6) alimentary tract and associate organs concerned with metabolism, (7) nervous system and sense organs, (8) skin, (9) endocrinal system, (10) all other causes. This would show organological breakdown rather than pathological causation. The breakdown of the respiratory system is the chief cause of death, and next comes that of the alimentary tract; these together constitute half the deaths biologically classifiable. Next come troubles with the blood and circulation. We may conceive these as three successive defense lines, and it is against the first two of these that better health and hygiene have been chiefly directed, having been most successful with the respiratory system. Child-welfare, both pre- and post-natal, is by all odds the most hopeful direction of public-health activities. Pearl’s very important studies here confirm the conclusions others have reached, that early pubertal years show the lowest mortality rate, and he traces in detail for each age of life the mortality curves for each of the chief groups of disease.
Very interesting are his conclusions touching the embryological basis of mortality in which he attempts totrace the causes of death back to the three primitive tissue elements, concluding that about 57 per cent of biologically classifiable deaths result from the breakdown or failure to function of organs arising from the endoderm, 8 to 13 per cent from those that spring from the ectoderm, while the remaining 30 to 35 per cent are of mesodermic origin. The ectoderm has been most widely differentiated from its primitive condition, as best illustrated by the central nervous system, the endoderm least differentiated, while the mesoderm is intermediate in this respect. Now, degrees of differentiation imply adaptation to the environment and the endoderm, which is least differentiated, is least able to meet vicissitudes. “Evolutionally speaking, it is a very old-fashioned and out-of-date ancestral relic which causes man an infinity of troubles. Practically all public-health activities have been directed toward overcoming the difficulties which arise because man carries about this antediluvian sort of endoderm.” Prior to the age of sixty the breakdown of organs of endodermic origin causes most deaths; next come breakdowns with organs of mesodermic origin, and lastly those of ectodermic origin. The rate for all these germ layers is relatively high in infancy, dropping to a low point in early youth. In infancy the chief mortality is due to endodermic defect; from about the age of 12 on, to faults of ectodermic, and after about 22 to those of mesodermic origin. The death-rate curve rises at a practically constant rate to extreme old age. From about 60 to the end of life deaths from the breakdown of organs of mesodermic origin lead. The heart generally outwears the lungs and the brain outwears both because evolution is a purely mechanical process instead of being an intelligent one. “It is conceivable that an omnipotent person could have made a much better machine as a whole than the human body which evolution has produced. He would presumably have made an endodermwith as good resisting and wearing qualities as a mesoderm or ectoderm. Evolution by the haphazard process of trial and error which we call natural selection makes each part only just good enough to get by.” All this, the author believes, only strengthens the evidence that the most important part in longevity is played by innate constitutional biological factors.
This view so commonly held, that heredity is the chief factor in longevity is doubtless correct in general. But it is fatalistic and directly tends to lessen the confidence of hygienists and physicians in the efficacy of all their methods of prolonging life in the aged. There is, we think, good reason to believe that there is a great and now rapidly growing number of exceptions to this so-called law, cases in which by conformity to right rules of living, age has been increased many years beyond that which our forbears attained. Indeed, the very fact of the gradual prolongation of life shows that the hereditary predisposition to die at a certain age can be, to a great extent, overcome. The psychological effect of this dogma of the prepotence of heredity in determining the length of life is itself not only depressing but may readily become, as psychologists can best understand, a dangerous lethal agent with the old and cause those who have reached the span of years at which their forbears died to succumb to their troubles with less resistance. Indeed, it is one of the chief purposes of this volume to show that the old-age problem is not merely economic, philanthropic, social, or even medical, but also, when all is said and done, perhaps chiefly psychological and that the future welfare of the race depends upon the development of an old age due not chiefly to heredity but to better knowledge and control of the conditions of this state of life.
Senescence is, in no small degree, a state of mind aswell as a state of body, and the study of it as such has been so far strangely neglected but is now in order. Even doctors who have told us most about it have made few intensive investigations of its nature and there are very few gerontologists; while the alienists who have described the senile psyche have done so only in general terms that add but little to what is obvious to common experience and observation. None have sought to ascertain empirically from intelligent old people capable of telling how they think and feel about their stage in life, or to determine how far their attitude toward it was indigenous and how far it was really due to the acceptance of current traditions that have come down to us from a remote past and that no longer fit present conditions. How this old tradition still influences even physicians may best be shown by a few instances that have come under my own observation. A friend of 73 fell sick of pneumonia which soon involved both lungs. The excellent family doctor had him removed to a hospital where expert care could be added to his own. Soon all hope of his recovery was abandoned and for a week friends who called or telephoned were told that nothing more could be done and the end was certain and might be expected any time. “He is 73, you know,” the doctor said. To-day he is well and daily active in the very large concern he created. The father of an intimate friend at the age of 69 fell ill from a complication of disorders the family doctor diagnosed as old age and telegraphed his son to hasten home from a distant city if he would see him alive. Upon his arrival, on the morning of the 70th birthday, he found him half comatose and convinced that this day would be his last; but he was cheered up, diverted, partook of a stimulated eggnog, his first food for two days; and when he awoke just past midnight and realized that he had entered upon another decade,revived, made a slow but surprising recovery, and enjoyed not only a comfortable but a very active life for nine years. He could not, however, quite bring his mind to enter the ninth decennium. Strangely enough, my friend’s mother, whom I had also known all my life, two years later passed through almost the same experience. He was called to her deathbed, reaching her three days after all hope had been abandoned. But she recovered and was nearly as well as before, and lived seven years. A friend of mine retired from a college chair at 74 and was told that he was worn out, had several grave symptoms, and must drop work and go South. “You should be satisfied,” his physician told him, “with four years beyond the allotted three score and ten.” But he had unfinished tasks, believed them to be life-preservers, and now at 82 is still engaged upon them. A vigorous old lady of 87 has thrice been given up by her physician within the decade. Are doctors a little falsetto in their treatment of the aged?
Seventy is, on the whole, the most dangerous milestone and the morning of that birthday is probably the saddest of all that those who attain it have known or will ever know. It brings a new consciousness that now indeed we are old; and if we still carry on as before, we are at least under the suspicion of affecting a vigor that we really lack and are liable to lapse to an apologetic state of mind because we do not step aside and give our place to our juniors who often feel that they have a right to it, even though they try not to show or even confess it to themselves. If we make partial withdrawal we find insistencies, conscious and unconscious, in those who supersede us that we might as well make it complete and the sense of being superfluous and no longer needed is bitter. Complete retirement from all our life work, whatever it is, may make us feel that we are already dead so far asour further usefulness is concerned. Yet at no stage of life do we want more to be of service than when we are deprived of our most wonted opportunities to be so. We do not take with entire kindness and resignation to being set off as a class apart.