To those unfamiliar with the subject in its larger aspects, the possibilities seem almost beyond belief. As an example of the wonderful gains which can be secured by obeying the laws of hygiene may be cited the case of a young man who a few years ago was scarcely able to drag himself into the sun in Colorado, where he was endeavoring to rid himself of tuberculosis. He not only succeeded, but subsequently, by dint of following substantially all of the rules of hygiene here laid down, became an athlete and capable of running twenty-five miles for sheer love of sport and apparently without the overstrain experienced by “Marathon” runners. Kant and Humboldt are cases typical in different fields of achievement of many of the world’s most vital men who have actually made over their constitutions from weakness to strength. Cornaro says that it was the neglect of hygienic laws which made him all but a dead man at thirty-seven, and that the thoroughgoing reform of his habits which he then effected made him a centenarian. His rules, drawn up four hundred years ago and described in his interesting work “The Temperate Life,” are, so far as they are explained, almost identical with those given in this book. It is difficult to assign a limit to the good which can be accomplished by practising these rules and so minimizing the poisons which usually narrow and shorten our lives.
Immortal Animal Cells
So far as science can reveal, there seems to be no principle limiting life. There are many good and bad reasons why men die, but no underlying necessary reason why they must die. The brilliant Carrel has kept tissue cells of animals alive outside of the body for the past three years. These cells are multiplying and growing, apparently unchanged by time, to all appearances immortal so long as they are periodically washed of poison and nourished in a proper medium. If we could at intervals thoroughly wash man free of his poisons and nourish him, there seems to be no reason why he should not live indefinitely.
Section V—Hygiene and Civilization
In view of the vast extent of human misery from ill health, the question naturally arises, How does it happen that the world is burdened with so colossal a load? Is it no more than is biologically normal? Is it true that in other organisms, animals and plants, ill health is the rule rather than the exception? Are all races of men subject to the same heavy load?
Natural Adjustments Upset
These questions have not yet received sufficient attention. The answer seems to be that man is suffering from his own mistakes made unconsciously and in ignorance. He has upset the equilibrium which Nature had established among the various powers and activities of his body, and between himself and the outside world. Man has done mischief for his own body similar to what he has done for the natural resources on which he lives. In Professor Shaler’s epoch-making little book, “Man and the Earth,” he shows, for instance, that the little layer of soil on the surface of the earth from which plants and animals derive their nutriment was, before the advent of man, replenished quite as fast as it was washed away, but that after man had put his plow into it and had taken off the protective mat of vegetation, he unconsciously despoiled the accumulation of ages. “In a plowed field, an hour’s torrential rain may wash off to the sea more than would pass off in a thousand years in the slow process of erosion which the natural state of the earth permits.” He also shows that the constant croppings of the soil rob it of nitrogen, phosphorus, and other elements faster than Nature restores them. The problem of conservation is to reestablish the balance which has been lost through the depredations of man, for instance, to lessen soil-wash by terracing, and to restore to the soil the lost elements by supplying nitrates and phosphates and by other methods of scientific farming.
In the same way man has upset his pristine animal mode of living and needs to find scientific ways to restore the equilibrium. Most of the present-day problems of hygiene arise from introducing, uncompensated, the effects of certain devices of civilization. The inventions of civilization have done so much for man that he is apt to unduly glorify them and to overlook the injurious by-products. These by-products are often of prodigious significance to the race. The invention of houses introduced the problem of house hygiene; the invention of clothing, the problem of clothing hygiene; that of cooking, the problem of food hygiene; that of division of labor, the problem of industrial hygiene; and so on. To make these statements more concrete, we may consider some of them in more detail.
Houses Artificial
The invention of houses has made it possible for men to live in all climates, yet this indoor living is responsible for much disease. The houses give comfortable shelter and warmth and protect us from the elements and from wild animals. But the protection has been overdone. Like his cousin, the anthropoid ape, man is biologically an outdoor animal. His attempt at indoor living has worked him woe, but so gradually and subtly has it done so that only recently have we come to realize the fact. At first, dwellings were really outdoor affairs, caves, lean-tos, tents, huts with holes in the roof and the walls. These holes served to ventilate, though they were not intended for that purpose. The hole in the roof was to let out the smoke and the holes in the walls to let in the light. Gradually the roof-hole developed into a chimney with an open fireplace, which, in turn, gradually changed into a small flue for stoves whereupon it almost ceased to serve any ventilating function. The stove in turn has largely gone and is replaced in many cases by the hot-water or steam radiator, without any attempt at ventilation. The holes in the wall gave way, after the invention of glass, to windows which let in the light without letting in the air. Weather-strips, double windows, vestibule-doors, interior rooms, completed the process of depriving man of his outdoor air, shutting him into a cell in which he now lives—a sickened but complaisant prisoner—often twenty hours of the twenty-four. Tuberculosis, one of the worst scourges of mankind, is primarily a house disease. It is prevalent as indoor living is prevalent, and reaches its maximum in the tenement quarter of a great city.