The Creation of God by Jacob Hartmann (color ebook reader TXT) 📖
- Author: Jacob Hartmann
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The vegetables contain from 75 to 90 per cent of water. Starch and sugars are derived from such as potatoes, turnips, carrots, beets, etc., etc.
The fruits are largely composed of water, sugars, and acids.
All these classes of food contain only three elements.—Starch:
In their composition we have fifteen molecules of water presented carrying eighteen atoms of carbon. Sugar:
In this case again we have eleven molecules of water carrying twelve atoms of carbon. This is the chemical composition of starch and sugar food.
2. Fats are also composed of three elements only—carbon, hydrogen, and oxygen. Take the fat of mutton or pork:
All other animal oils and fats are composed of these three elements only.
3. Albuminous substances—meats, beef, mutton, veal, pork, birds, and fish, of all descriptions.
4. Besides these, mineral salts, already mentioned.
5. And lastly, water—of which by far the greatest quantity is consumed.
The quantity of food ought to be in amount sufficient to replace the waste products of the body. An amount should be taken into the system equal in kind and quantity to the material expended.
Since we know the amount of carbon, hydrogen, nitrogen, oxygen, and the salts that are excreted by the kidneys, skin, and lungs, we may easily calculate the amount of various kinds of food needed to replace them. The outcome being known, the income can be regulated accordingly.
The expenditure or waste, we have seen, in daily loss amounts in carbon to about 4,500 grains, and in nitrogen to 300 grains; besides a certain quantity of water, etc. We therefore require starchy substances, meat and fat, water, etc., to replace the quantity lost. Bread, for example, contains 30 per cent of carbon and 1 per cent of nitrogen. If bread alone, therefore, were taken as food, a man would require in order to obtain the requisite nitrogen 30,000 grains, containing of carbon, 9,000 grains; of nitrogen, 300 grains—an excess of carbon above the amount required of 4,500 grains. But a combination of bread and meat would supply much more economically what was necessary:
So that ¾ pounds meat and 2 pounds of bread, or its equivalent, would supply the needful carbon and nitrogen with but little waste.
From all these facts it will be plain that a mixed diet is the best and most economical for man; and the result of experience entirely coincides with what might have been anticipated on theoretical grounds only.
The quality and quantity of foods to be taken depends largely upon their digestibility.
The quantity of food necessary for a healthy man taking free exercise in the open air is as follows:
The quantity and quality of food taken into the system every twenty-four hours, should depend upon the amount and kind of labor done, whether muscular or nervous, whether sitting or not, inactive or active, whether indoors or out of doors; upon the kind of atmosphere we breathe; upon season and climate, etc.; also upon the opportunities we have of throwing off the surplus carbon and nitrogen that the system has been overcrowded with.
These conditions determine the proper variations of the income, since that has to be regulated and corrected by the outcome, and amounts after all to just so much carbon, hydrogen, oxygen, nitrogen, sulphur, phosphorus, saline matter, and water as are contained in the proteids, fats, carbohydrates, salts, and water.
It matters little how food is prepared. The main feature is that the supply is equal to the loss, of good and wholesome quality. Whether the food is manipulated by an artistic $10,000 cook or by a plain, clean housewife, the result is the same. Whether the special sense of taste, the gustatory nerve, has or has not undergone a high course of training and education, the fact remains that all that can be supplied is the necessary material that has been expended by the work and labor done by the muscular and nervous tissues.
The subjoined results, selected from Boussingault, exhibit in a tabular form the relative quantity of organic and inorganic constituents in several kinds of herbage compared in several cases with the root or grain. The water was previously driven off by thorough drying:
Subjoined is a table from the same work of the percentage of mineral substances taken up from the soil by various plants:
The expenditures of the human body, or the waste products which arise from the activity of the master tissues, are thrown off by the excretory tissues, as the lungs, the skin, the kidneys, and the terminal part of the intestines.
The lungs are hollow organs, and we may consider them as really two bags containing air, each of which communicates by a separate orifice with a common air tube, through the upper part of which, the larynx, they freely communicate with the external atmosphere. The orifice of the larynx is guarded by muscles, and can be opened or closed at will.
Each lung is partially subdivided into separate portions called lobes. The right lung has three lobes, and the left lung has two. Each of these lobes, again, is composed of a large number of minute parts, called lobules. Each pulmonary lobule may be considered a lung in miniature, consisting as it does of a branch of a bronchial tube, air-cells, blood-vessels, nerves, and lymphatics, with a sparing amount of areolar tissue.
The terminal portion of each lobule is composed of a group of pouches or air-cells, which communicate with the intercellular air passages. These cells are of various forms, according to the mutual pressure to which they are subject. Their cell walls are nearly in contact, and they vary from 1⁄50 to 1⁄90 of an inch in diameter.
Outside the cells a network of pulmonary capillaries is spread out so densely that the interspaces or meshes are even narrower than the vessels, which are on an average 1⁄3000 of an inch in diameter.
Between the atmospheric air in the cells and the blood in the vessels nothing intervenes but the thin membrane of the cells and the capillaries, and the delicate epithelium lining the former. And the exposure of the blood to the air is the more complete because the folds of membrane between contiguous cells, and often the spaces between the walls of the same, contain only a single layer of capillaries, both sides of which are thus at once exposed to the air.
The enlargement of the capacity of the chest in inspiration is a muscular act; the muscles concerned in producing the effect being chiefly the diaphragm, the external intercostal muscles, etc.
From the enlargement produced in inspiration, the chest and lungs return in ordinary tranquil expiration by their elasticity; the force employed by the inspiratory muscles in distending the chest and overcoming the elastic resistance of the lungs and chest wall being returned as an expiratory effort when the muscles are relaxed.
The acts of expansion and of contraction of the chest take up, under ordinary circumstances, a nearly equal time, and can scarcely be said to be separated from each other by an intervening pause. The quantity of air that is changed in the lungs in each act of ordinary tranquil breathing is variable, but probably 30 to 35 cubic inches are a fair average in the case of healthy young and middle-aged men. The total quantity of air which passes into and out of the lungs of an adult, at rest, in 24 hours, has been estimated to be about 686,000 cubic inches. This quantity is largely increased by exertion; and it has been computed that the average amount for a hard-working laborer in the same time is 1,568,390.
Breathing air is the quantity of air which is habitually and almost uniformly changed in each act of breathing.
Complemental air is the quantity of air over and above this which a man can draw into the lungs in the deepest inspiration.
After ordinary expiration, such as that which expels the breathing air, a certain quantity of air remains in the lungs which may be expelled by a forcible and deeper expiration; this is termed reserve air. But even after the most violent expiratory effort, the lungs are not completely emptied; a certain quantity of air remains
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