A Handbook of Health, Woods Hutchinson [black authors fiction .TXT] 📗

How and Why our Breathing Varies. When you run or wrestle, you breathe faster in order to draw more air into the lungs. At the same time, your heart beats faster in order to drive a larger amount of blood through the lungs. If you run too far, or wrestle too hard, your heart and your lungs both go faster and faster, until finally they reach a point when they cannot go any quicker, and the poisonous waste substances are formed in your muscles faster than they can possibly be burned up, even by the quickest breathing and the hardest pumping of your heart. Then you begin to get "out of breath"; and if you were compelled—in order to save your life, for instance—to keep on running, or fighting, you would at last be suffocated by your own waste and dirt, and fall exhausted, or unconscious.

On the other hand, by carefully training your muscles and your heart and your lungs by exercises of various sorts in the open air, beginning with easy ones and going on to harder and longer ones, you can "improve your wind," so that your heart will be able to pump more blood through the lungs per minute, and your lungs will be able to expand themselves more fully and more rapidly without fatigue.

If you can recall having had a fever of any sort, even a slight one, such as comes with a sore throat or a bad cold, you may remember that you breathed faster and that your heart beat faster, and yet you were not doing any work with your muscles. The cause, however, is the same; namely, the amount of waste that is being produced in the body—in this case, by the poisons (toxins) of the germs that cause the fever. The more waste that is formed in the body, the more effort the heart and lungs will make to try to get rid of it.

The Ribs. How does the air get in and out of the lung tubes? Evidently you do not and cannot swallow it as you would food or drink; and as it will not run down of its own accord when you simply open your mouth, nature has had to devise a special bit of machinery for the purpose of sucking it in and pressing it out again. This she has done in a rather ingenious manner by causing certain of the muscle-rings in the wall of the chest to turn first into gristle, or cartilage, and then later into bone, making what are known as the ribs; these run round the chest much as hoops do round a barrel, or as the whalebone rings did in the old-fashioned hoop skirt. When the muscles of the chest pull these ribs up, the chest is made larger,—like a bellows when you lift the handle,—air is sucked in, and we "breathe in" as we say; when the muscles let go, the ribs sink, the chest flattens and becomes smaller, the air is driven out, and we "breathe out."

Free Air is Pure. As air, in the form of wind, actually sweeps all outdoors, day and night, it clearly is likely to pick up a good many different kinds of dust and dirt, which may not be wholesome when breathed into our lungs. Fortunately, nature's great outdoor system of purifying the air is almost perfect, so that it is only when we build houses and shut in air from the great outdoor circulation, that "dirt" that is really dangerous begins to get into it. Caged air is the only air that is dangerous. Free-moving air is always perfectly safe to breathe any hour of the day or night, or any season of the year.

Shut-in and Stagnant Air is Foul. This restless air-gas cannot be stored outside of the body, any better than it can be inside. For one thing, it is too bulky; and for another, it begins to become impure in various ways, as soon as it is shut up. It is the most unmanageable food that we "eat," for we can neither cook it nor wash it like solid food, nor filter it nor boil it like water, except on a very limited scale. We can do nothing to it except to foul it, which we do with every breath that we breathe, every fire that we make, every factory that we build. Our only chance of safety, our only hope of life, is to connect every room and every corner of those little brick and mortar boxes, those caged sections of out-of-doors, that we call houses, with nature's great system of air supply, "All Outdoors." Fortunately, the only thing needed to make the connection is to open a window—no need to send for a plumber or put in a meter, and there is no charge for the supply after connections have been made.

The Enormous Amount of Air. Air outdoors is everywhere, for practical purposes, absolutely pure, just as water is when it comes down from the clouds. And like water, its only dangerous impurities are what we put there ourselves. The purity of outdoor air is due mainly to the fact that there is such an enormous amount of it, not only the miles and miles of it that stretch away on every side of us, but nearly thirty miles of it straight up above our heads; its purity is also due to the fact that, like water, it is always in motion. When heated by the sun, it expands; and, in doing so, it rises because it is less dense and therefore lighter. As soon as the pressure of the air above is lessened, air rushes in below from all the cooler regions around. This rushing of air we call a wind. If the low pressure lies to the north of us, the air rushes northward over us to fill it, and we say the wind is from the south; if the air is flowing to the south of us, we say the wind is from the north.

How Air is Purified. In these winds certain small amounts of dust, or dirt, or leaf mould are whirled up into the air, but these are promptly washed down again whenever it rains; and the same is true of the smoke impurities in the air of our great cities. Air is also constantly being purified by the heat and light of the sunbeams, burned clean in streaks by the jagged bolt of the lightning in summer, and frozen sweet and pure by the frosts every winter. So that air in the open, or connected with the open, and free to move as it will, is always pure and wholesome. But to be sure of this, it must be "eaten alive"—that is, in motion. Stagnant air is always dead and, like all dead things, has begun to decay.

The Carbon Dioxid in the Air. Air, as you will remember (p. 132), is a mixture of oxygen and nitrogen, and its value in the body is that it gives off part of its oxygen to combine with the body wastes and burn them to carbon dioxid. Oddly enough, even pure outdoor air contains tiny traces of carbon dioxid; but the amount is so very small as to be of no practical importance, in spite of the fact that every kind of animal that lives and moves upon the earth is pouring it out from his lungs every second. The rapidity with which it disappears is due in part to the rapidity with which it rises and spreads, or is blown, in every direction; and in part to the wonderful arrangement by which, while animals throw off this poisonous gas as waste, plants eagerly suck it in through the pores in their leaves and eat it, turning it into the carbohydrates, starch and sugar, which, in turn, become valuable foods for the animals. So perfect is this system of escape, or blowing away, of carbon dioxid, combined with its being eaten up by plants, that even the air over our great cities and manufacturing towns contains only the merest trifle more of carbon dioxid than that over the open country. Its other smoke-impurities, dirts and dusts, escape, or are blown away so rapidly that they are seldom thick enough to be injurious to health, except in the narrowest and darkest streets; so that it is always safe to open your windows wide for air, wherever you may live. The principal danger from smoke is that it cuts off the sunlight.

The Necessity for Ventilation—Impurities of Indoor Air. The worst impurities in air are those that come from our own breaths and our own bodies; and, unexpectedly enough, carbon dioxid is not one of them. In spite of hundreds of experiments, we do not yet know exactly what these impurities are, though they are doubtless given off from our lungs, our skins, our mouths, and teeth, especially if the latter are not kept clean and sweet, but left dirty and decaying.

We do know, however, to a certainty that air shut up in a room, or house, with