American Woman's Home: Or, Principles of Domestic Science. Гарриет Бичер-СтоуЧитать онлайн книгу.
is the chief element of brain and nerves; and calcium or lime is the hard portion of the bones. Iron is an important element of blood, and silicon supplies the hardest parts of the teeth, nails, and hair.
Water, which is composed of the two gases, oxygen and hydrogen, is the largest portion of the body, forming its fluids; there is four times as much of carbon as there is of nitrogen in the body; while there is only two per cent as much phosphorus as carbon. A man weighing one hundred and fifty-four pounds, who leads an active life, takes into his stomach daily from two to three pounds of solid food, and from five to six pounds of liquid. At the same time he takes into his lungs, daily, four or five thousand gallons of air. This amounts to three thousand pounds of nutriment received through stomach and lungs, and then expelled from the body, in one year; or about twenty times the man's own weight.
The change goes on in every minute point of the body, though in some parts much faster than in others; as set forth in the piquant and sprightly language of Dr. O. W. Holmes [Footnote: Atlantic Almanac, 1869, p. 40.], who, giving a vivid picture of the constant decay and renewal of the body, says:
"Every organized being always lives immersed in a strong solution of its own elements."
"Sometimes, as in the case of the air-plant, the solution contains all its elements; but in higher plants, and in animals generally, some of the principal ones only. Take our own bodies, and we find the atmosphere contains the oxygen and the nitrogen, of which we are so largely made up, as its chief constituents; the hydrogen, also, in its watery vapor; the carbon, in its carbonic acid. What our air-bath does not furnish us, we must take in the form of nourishment, supplied through the digestive organs. But the first food we take, after we have set up for ourselves, is air, and the last food we take is air also. We are all chameleons in our diet, as we are all salamanders in our habitats, inasmuch as we live always in the fire of our own smouldering combustion; a gentle but constant flame, fanned every day by the same forty hogsheads of air which furnish us not with our daily bread, which we can live more than a day without touching, but with our momentary, and oftener than momentary, aliment, without which we can not live five minutes."
"We are perishing and being born again at every instant. We do literally enter over and over again into the womb of that great mother, from whom we get our bones, and flesh, and blood, and marrow. 'I die daily' is true of all that live. If we cease to die, particle by particle, and to be born anew in the same proportion, the whole movement of life comes to an end, and swift, universal, irreparable decay resolves our frames into the parent elements."
"The products of the internal fire which consumes us over and over again every year, pass off mainly in smoke and steam from the lungs and the skin. The smoke is only invisible, because the combustion is so perfect. The steam is plain enough in our breaths on a frosty morning; and an over-driven horse will show us, on a larger scale, the cloud that is always arising from own bodies."
"Man walks, then, not only in a vain show, but wrapped in an uncelestial aureole of his own material exhalations. A great mist of gases and of vapor rises day and night from the whole realm of living nature. The water and the carbonic acid which animals exhale become the food of plants, whose leaves are at once lungs and mouths. The vegetable world reverses the breathing process of the animal creation, restoring the elements which that has combined and rendered effete for its own purposes, to their original condition. The salt-water ocean is a great aquarium. The air ocean in which we live is a 'Wardian case,' of larger dimensions."
It is found that the simple elements will not nourish the body in their natural state, but only when organized, either as vegetable or animal food; and, to the dismay of the Grahamite or vegetarian school, it is now established by chemists that animal and vegetable food contain the same elements, and in nearly the same proportions.
Thus, in animal food, carbon predominates in fats, while in vegetable food it shows itself in sugar, starch, and vegetable oils. Nitrogen is found in animal food in the albumen, fibrin, and caseine; while in vegetables it is in gluten, albumen, and caseine.
[Illustration: Fig. 55]
It is also a curious fact that, in all articles of food, the elements that nourish diverse parts of the body are divided into separable portions, and also that the proportions correspond in a great degree to the wants of the body. For example, a kernel of wheat contains all the articles demanded for every part of the body. Fig. 55 represents, upon an enlarged scale, the position and proportions of the chief elements required. The white central part is the largest in quantity, and is chiefly carbon in the form of starch, which supplies fat and fuel for the capillaries. The shaded outer portion is chiefly nitrogen, which nourishes the muscles, and the dark spot at the bottom is principally phosphorus, which nourishes the brain and nerves. And these elements are in due proportion to the demands of the body. A portion of the outer covering of a wheat-kernel holds lime, silica, and iron, which are needed by the body, and which are found in no other part of the grain. The woody fibre is not digested, but serves by its bulk and stimulating action to facilitate digestion. It is therefore evident that bread made of unbolted flour is more healthful than that made of superfine flour. The process of bolting removes all the woody fibre; the lime needed for the bones; the silica for hair, nails, and teeth; the iron for the blood; and most of the nitrogen and phosphorus needed for muscles, brain, and nerves.
Experiments on animals prove that fine flour alone, which is chiefly carbon, will not sustain life more than a month, while unbolted flour furnishes all that is needed for every part of the body. There are cases where persons can not use such coarse bread, on account of its irritating action on inflamed coats of the stomach. For such, a kind of wheaten grit is provided, containing all the kernel of the wheat, except the outside woody fibre.
When the body requires a given kind of diet, specially demanded by brain, lungs, or muscles, the appetite will crave food for it until the necessary amount of this article is secured. If, then, the food in which the needed aliment abounds is not supplied, other food will be taken in larger quantities than needed until that amount is gained. For all kinds of food have supplies for every want of the body, though in different proportions. Thus, for example, if the muscles are worked a great deal, food in which nitrogen abounds is required, and the appetite will continue until the requisite amount of nitrogen is secured. If, then, food is taken which has not the requisite quantity, the consequence is, that more is taken than the system can use, while the vital powers are needlessly taxed to throw off the excess.
These facts were ascertained by Liebig, a celebrated German chemist and physicist, who, assisted by his government, conducted experiments on a large scale in prisons, in armies, and in hospitals. Among other results, he states that those who use potatoes for their principal food eat them in very much larger quantities than their bodies would demand if they used also other food. The reason is, that the potato has a very large proportion of starch that supplies only fuel for the capillaries and very little nitrogen to feed the muscles. For this reason lean meat is needed with potatoes.
In comparing wheat and potatoes we find that in one hundred parts wheat there are fourteen parts nitrogen for muscle, and two parts phosphorus for brain and nerves. But in the potato there is only one part in one hundred for muscle, and nine tenths of one part of phosphorus for brain and nerves.
The articles containing most of the three articles needed generally in the body are as follows: for fat and heat-making—butter, lard, sugar, and molasses; for muscle-making—lean meat, cheese, peas, beans, and lean fishes; for brain and nerves—shell-fish, lean meats, peas, beans, and very active birds and fishes who live chiefly on food in which phosphorus abounds. In a meat diet, the fat supplies carbon for the capillaries and the lean furnishes nutriment for muscle, brain, and nerves. Green vegetables, fruits, and berries furnish the acid and water needed.
In grains used for food, the proportions of useful elements are varied; there is in some more of carbon and in others more of nitrogen and phosphorus. For example, in oats there is more of nitrogen for the muscles, and less carbon for the lungs, than can be found in wheat. In the corn of the North, where cold weather demands fuel for lungs and capillaries, there is much more carbon to supply it than is found in the Southern corn.
From these statements it may be seen that one of the chief mistakes in