(1) A foot that has never worn a shoe (from a photograph); (2) A foot so cramped and bent as to prevent firmness of step and gait.]

Our Shoes, an Important Factor in Health. Few more ingenious instruments of crippling and torture have ever been invented than fashionable tight shoes with high heels.

Kipling never said a shrewder or truer thing than when he made Mulvaney, the old Irish drill-sergeant, tell the new recruit, "Remimber, me son, a soljer on the marrch is no betther than his feet!" and this applies largely to the march of life as well.

Every shoe should be at least three-quarters of an inch longer, and from half to three-quarters of an inch wider, than the foot at rest, to allow proper expansion of these great "carriage-spring" arches. If children run free in the open air, either barefoot, or with light, loose, well-ventilated shoes, or sandals, they will have little trouble, not only with bunions, corns, "flat-foot," or lameness, but also with their backs, their gait, and their carriage. Easily half of our backaches, and inability to walk far or run fast in later life, to say nothing of over-fatness and dyspepsia, are caused by tight shoes.

SLEEP AND REST

Why We Need Rest. A most important element in a life of healthful exercise, study, and play is rest. Even when we are hard at work, we need frequent breathing spells and changes of occupation and amus.e.m.e.nt to keep one part of our muscles, or our brains, from poisoning itself.

But after a time, in even the strongest and toughest of us, there comes a period when no change of occupation, no mere sitting still, will rest us; we begin to feel drowsy and want to go to sleep. This means partly that the fatigue poisons, in spite of fresh air and change, have piled up faster than we can burn them, so that we need sleep to restore the body.

All day long we are making more carbon dioxid than the oxygen we breathe in can take care of; while we sleep, the situation is reversed--the oxygen is gaining on the carbon dioxid. This is why the air in our bedrooms ought to be kept especially pure and fresh.

But the need goes deeper than this: sleeping and waking are simply parts of the great rhythm in which all life beats--a period of work followed by a period of rest. Continuous, never-ceasing activity for any living thing quickly means death. While externally the body appears to be at rest, the processes of growth and upbuilding probably go on more rapidly when we are asleep than when we are awake. The benefits of exercise are made permanent and built into the body during the sleep that follows it.

The more rapidly young animals are growing, the more hours out of the twenty-four they spend in sleep. When you sleep, you are not stopping all the useful activities of your body and mind, you are simply giving some of the most useful and most important of them a chance to work. The only likeness between sleep and death is that in both the body is quiet and the eyes are closed. Really we are never more alive and growing than when asleep.

It is of the utmost importance that young children especially have all the sleep they need, and that is precisely all that they can be induced to take. The best rule for you, then, to follow, is to go to bed when you feel sleepy, and to get up when you wake rested. Every child under twelve should have at least ten hours of sleep, and every grown person eight, or better still, nine hours. Time spent in sound, refreshing sleep, is time well spent. If you cannot sleep well, it is a signal that something is wrong with your health, or your habits--a danger signal of great importance, which should be attended to at once. The best and only safe sleep-producer is exercise in the open air.

DISORDERS OF MUSCLES AND BONES

The Muscles and Bones Have Few Diseases. Considering how complex it is, and the never-ceasing strain upon it, this moving apparatus of ours, the nerve-bone-muscle-machine, is surprisingly free from disease. The muscles, though they form nearly half our bulk, have scarcely a single disease peculiar to them, or chiefly beginning in them, unless fatigue and its consequences might be so regarded. They may become weakened and wasted by either lack or excess of exercise, by under-feeding, or by loss of sleep; but most of their disturbances are due to poisons which have got into the blood pumped through them, or to paralysis or other injuries to the nerves that supply them.

The muscles of an arm, for instance, which has been lashed to a splint, or shut tightly in a cast for a long time, waste away and shrink until the arm becomes, as we say, "just skin and bone"; and the same thing will happen if the nerve supplying a muscle, or a limb, is cut or paralyzed.

The bones have more diseases than the muscles, but really comparatively few, considering their great number and size, and the constant strain to which they are subjected in supporting the body, and driving it forward and doing its work under the handling and leverage of the muscles. Most of their diseases are, like those of the muscles, the after-effects of general diseases, particularly the infections and fevers, which begin elsewhere in the body; and the best treatment of such bone diseases is the cure and removal of the disease that caused them.

[Ill.u.s.tration: CALLUS FORMED AROUND A FRACTURE

An aluminum splint holds the parts of the bone together.]

Repair of Broken Bones. If bones are broken by a fall, or blow, they display a remarkable power of repair. The "skin" covering them (periosteum) pours out a quant.i.ty of living lime-cement, or animal-mortar, around the two broken ends, which solders them together, much as a plumber will make a joint between the ends of two pipes. This repair substance is called _callus_. The most remarkable thing about the process is that, when it has held the two broken ends together long enough for them to "knit" firmly--that is, to connect their blood vessels and marrow cavities properly--this handful of lime-cement, which has piled up around the break, gradually melts away and disappears; so that, if the ends of the bone have been brought accurately together, you can hardly tell where the break was, except by a slight ridge or thickening.

TROUBLES OF THE NERVOUS SYSTEM

The Nervous System is not easily Damaged. The nervous system is subject to a good many more diseases than are either the muscles or the bones; but, considering how complex it is, it is not nearly so easily damaged or thrown out of balance as we usually imagine, and has astonishing powers of repair. Instead of being one of the first parts of the body to be attacked by a disease, such as an infection or a fever, it is one of the very last to feel the effects of disease, except in the sense that it often gives early that invaluable danger signal, pain.

Headache. Next after fatigue the most valuable danger signal given us by our nerves is that commonest of all pains, _headache_. Indeed, it is not too much to say that headache is the most useful pain in the world.

It has little to do with the condition of the brain, but occurs in the head chiefly because the nerves of the head and face are the most sensitive of all those in the body, and the first ones, therefore, to "cry out" when hurt.

Headache has been described as the cry of a poisoned or starved or over-worked nerve, and is simply nature's signal that something is going wrong. Toxins, or poisons, formed anywhere in the body, from any cause, get into the blood, are carried to the sensitive nerves of the head and face, and irritate them so that they ache. It is foolish to try to do anything to the head itself for the relief of headache, although cold cloths, or a hot-water bottle, may be soothing in mild cases. The thing to do is to clear the poison out of the blood, and the only way is to find what has caused it.

Nearly all the things that cause headache do so by poisoning the blood.

A very common cause of headache, for instance, is getting over-tired, especially if at the same time you do not get enough sleep; and, as you already know, tiredness, or fatigue, is a form of self-poisoning.

Another very common cause of headache is bad air--sitting or sleeping in hot, stuffy rooms with the windows shut tight. If you do this, not only are you not getting oxygen enough into your blood to burn up the waste poisons that your own cells are making all the time, but also you are breathing in the waste poisons from other people's lungs, and the germs that are always in bad air.

Another very common cause of headache is _eye-strain_. Whenever you find that, when you try to read, the letters begin to dance before your eyes, and your head soon begins to ache, it is a sign that you need to have your eyes examined and perhaps a pair of gla.s.ses fitted to enable you to see properly.

Constipation and disturbances of digestion also very often cause headache by poisoning the blood; and, as you know, the first sign of a bad cold, or the beginning of a fever, or other illness, will often be a bad headache.

In short, a headache always means that something is going wrong; and the thing to do is to set to work at once to see if you can find out what has caused it, and then to remove the cause. If you cannot find out the cause, then go to a doctor and ask him to tell you what it is, and what to do to get rid of it.

Above all things, don't swallow a dose of some kind of headache medicine, and go on with your work, or your bad habits of eating, or using your eyes; because, even though it may relieve the pain, it doesn't do anything whatever to remove the cause and leaves you just as badly off as you were before you took it. Besides, most of these headache medicines, which for a time will relieve the pain of a headache, are narcotics, or pain-deadeners; and in more than very moderate doses they are poisons, and often dangerous ones. Those in commonest use, known as the "coal tar" remedies, because the chemists make them out of coal tar,[27] are likely to have a weakening effect upon the heart; and, while not very dangerous in small doses, they are very bad things to get into the habit of using.

The Exaggerated Claims of Patent Medicines. The same thing must be said of the habit of dosing yourself every time you feel a pain or an ache, with some sort of medicine, whether obtained at some previous time from a doctor, or bought at a drug store. A large majority of the medicines that are most widely advertised to cure all sorts of pains and aches contain some form of narcotic--most commonly either alcohol or opium. The reason for this is that no one medicine can possibly be a cure for all sorts of diseases; and the only kind of medicine that will make almost every one who takes it feel a little bit better for the time being is a narcotic, because it has the power of deadening the nerves to pain or discomfort.

Careful a.n.a.lyses by boards of health and government chemists of a great number of advertised medicines have shown that three-fourths of the so-called tonics and "bitters" and "bracers" of all sorts contain alcohol--some of them in such large amounts as to be stronger and more intoxicating than whiskey. The same investigations have found that a large majority of the "colic cures," "pain relievers," nearly all the "soothing syrups" and "teething syrups," and most of the cough mixtures, cough cures, and consumption cures contain opium, often in quite dangerous amounts. The widely-advertised medicines and remedies guaranteed to cure all sorts of diseases in a very short time are almost certain to be one of two things: either out-and-out frauds, costing about four cents a bottle and selling for fifty cents or a dollar, or else dangerous poisons. All patent pain relievers are safe things to let entirely alone.

Another risk in taking medicines wholesale, especially those that are known as patent medicines, is that you never can be quite sure what you are taking, as their composition is usually kept a strict secret. It may happen to be something very good for your disease, it may be entirely useless, and it may be something very harmful. There is no one drug, or medicine, known to the medical profession, that will cure more than one or two diseases, or relieve more than four or five disturbed and uncomfortable conditions. As you not only do not know what you are taking, but are not always quite sure what is the matter with you, the chances of your getting the right remedy for your disease are not much more than one in a hundred. If it isn't the right thing, you are certainly wasting your money, and may be doing yourself a serious injury.

We should not pour drugs of which we know little into a body of which we know less. Doctors give scarcely a fourth as much medicine now as they did fifty years ago. The best cures are food, exercise, sleep, and fresh air.

The Effects of Disease. In the case of nearly all infectious diseases, the effects on the nervous system are among the last to appear, and may not occur until weeks, months, or even years after the main fever or attack of sickness. This is one of the reasons why, when they do occur, they are often hard to cure; the whole system has become saturated with the poisons before they reach the nerves at all. So it happens that the idea has grown up that nervous diseases are very hard to cure. When, however, we know that two-thirds of them are a late result of some of the preventable infectious diseases and fevers, we can realize that it is perfectly possible to prevent them, and that prevention is the best cure.

The poisons that attack the brain and nervous system may be formed in the body by disease germs or brought in from without, as are alcohol, tobacco, lead, or a.r.s.enic. Even such mild infections as measles, scarlet fever, and influenza may poison certain nerves supplying the muscles of an arm or a leg, causing temporary paralysis, or even permanent laming; or they may attack the nerve of sight or of hearing and produce blindness or deafness.

A great many of the cases of paralysis and insanity are caused by alcohol. Alcohol in excess may attack the nerves supplying the arms and legs, producing severe pain and partial paralysis. It may also, after long-continued use, affect the cells of the brain itself, producing the horrible condition known as delirium tremens--a form of acute insanity with distressing delusions, in which the patient imagines that he sees rats, snakes, and other reptiles and vermin crawling over him, or in his room. Even in those who never use it to such excess as this, or indeed in those who may never become intoxicated, the long-continued use of alcohol may produce a slow poisoning and general breaking-down of the whole nervous system, causing in time the hand to tremble, the eye to become bleared and dim, the gait weak and unsteady, the memory uncertain, and the judgment poor.

Are Nervous Diseases Increasing? The direct use of the brain and nervous system has much less to do with the production of its diseases or even its serious disturbances than is usually believed. Most of these, as we have seen, are due either to the poisons of disease or alcohol, or to the fatigue-poisons, or other poisons, produced in the stomach, the liver, the muscles, or other parts of the body. The worst results of brain-work are due to the extent to which it deprives us of proper exercise and fresh air. Good, vigorous mental activity,--hard brain work, in fact,--when you are in good condition, is, if not overdone, as healthful and almost as invigorating as physical exercise or hearty play. We often hear it said that the rush and hurry of our modern strenuous life is increasing the number of mental diseases and nervous breakdowns. But there is no evidence that the strain of civilization upon our brains and nervous systems is damaging them, or that either nervous diseases or insanity are more frequent now than they used to be one hundred or five hundred years ago. In fact, all the evidence that we have points in exactly the opposite direction; for, as we have seen, most of these brain and nerve diseases are due to infectious diseases, bad food, and bad living conditions generally, all of which the progress of modern civilization is rapidly lessening and preventing.

We are collecting our insane in modern hospitals and comfortable homes, instead of letting them wander in rags about the country, and this makes them live longer and seem more numerous. But the poorest and least highly civilized cla.s.ses and races have much more insanity among them than those who live under more favorable conditions.

FOOTNOTES:

[27] Some of these coal-tar remedies are _Acetanilid_, and _Antipyrin_, and _Phenacetin_.

CHAPTER XXII

EXERCISE AND GROWTH

Fatigue as a Danger Signal. The chief use of exercise in childhood, whether of body or mind, is to make us grow; but it can do this only by being kept within limits. Within these limits it will increase the vigor of the heart, expand the lungs, clear the brain, deepen sleep, and improve the appet.i.te. Beyond these limits it stunts the body, dulls the brain, overstrains the heart, and spoils the appet.i.te. How are we going to tell when these limits are being reached? Nature has provided a danger signal--fatigue, or "tiredness."

Fatigue is due, not to complete exhaustion, but to poisoning of the muscle, or nerve, by its own waste substances. If the fatigue is general, or "all over," it is from these waste substances piling up in the blood faster than the lungs, skin, and kidneys can get rid of them.

In other words, fatigue is a form of self-poisoning.

We can see how it is that exercise, which, up to the point of fatigue, is both healthful and improving, when carried on after we are tired, becomes just the opposite. Fatigue is nature's signal, "Enough for this time!" That is why all methods of training for building up strength and skill, both of mind and muscle, forbid exercising beyond well-marked fatigue. If you yourself stop at this point in exercising, you will find, the next time you try that particular exercise, that you can go a little further before fatigue is felt; the third time, a little further yet; and so, by degrees, you can build up both your body and brain to the fullest development of which they are capable.

In muscular training, a series of light, quick movements, none of which are fatiguing, repeated fifteen, twenty, or a hundred times, will do much more to build up muscle and increase strength, than three or four violent, heaving strains that tax all your strength. Real athletes and skilled trainers, for instance, use half-or three-quarter-pound dumb-bells and one-or two-pound Indian clubs, instead of the five-pound dumb-bells and ten-pound clubs with which would-be athletes delight to decorate their rooms. A thoroughbred race-horse is trained on the same principle: he is never allowed to gallop until tired, or to put out his full speed before he is well grown. In fact, the best methods of all forms of exercising and training always stop just short of fatigue.

Education and study ought to be planned on the same principle. Exercise of either our muscles or our minds after they have begun to poison themselves through fatigue never does them any good, even if it does not do them serious harm; and, where the exercise is for the sake of building us up and developing our powers, it is best to stop for a little while, or change the task, as soon as we begin to feel distinctly tired, and then to try it again when we are rested.

[Ill.u.s.tration: A TRAINED BODY