A Treatise on Domestic Economy; For the Use of Young Ladies at Home and at School. Beecher Catharine Esther
from which the gastric juice is secreted by minute vessels in the coat of the stomach. This mixes with the food, and reduces it to a soft pulpy mass, called chyme. It then passes through the lower end of the stomach, into the intestines, which are folded up in the abdomen, and the upper portion, only, of which, is shown in the engraving, at A, A. The organ marked L, L, is the liver, which, as the blood passes through its many vessels, secretes a substance called bile, which accumulates in the gall-bladder, marked B. After the food passes out of the stomach, it receives from the liver a portion of bile, and from the pancreas the pancreatic juice. The pancreas does not appear in this drawing, being concealed behind the stomach. These two liquids separate the substance which has passed from the stomach, into two different portions. One is a light liquid, very much like cream in appearance, and called chyle, of which the blood is formed; the other is a more solid substance, which contains the refuse and useless matter, with a smaller portion of nourishment; and this, after being further separated from the nourishing matter which it contains, is thrown out of the body. There are multitudes of small vessels, called lacteals, which, as these two mixed substances pass through the long and winding folds of the intestines in the abdomen, absorb the chyle, and convey it to the thoracic duct, which runs up close by the spine, and carries the chyle, thus received, into a branch of the vena cava superior, at t, whence it is mingled with the blood going into the heart. In this engraving, the lacteals and thoracic duct are not shown; but their position is indicated by the dotted lines, marked X, Y; X, being the lacteals, and Y, the thoracic duct.
In the upper half of the engraving, H represents the heart; a, the commencement of the aorta; v c s, the termination of the vena cava superior. On each side of the heart, are the lungs; l l, being the left lobe, and r l, the right lobe. They are composed of a network of air-vessels, blood-vessels, and nerves. W, represents the trachea, or windpipe, through which, the air we breathe is conducted to the lungs. It branches out into myriads of minute vessels, which are thus filled with air every time we breathe. From the heart, run the pulmonary arteries, marked p a. These enter the lungs and spread out along-side of the branches of the air-vessels, so that every air-vessel has a small artery running side by side with it. When the two vena cavas empty the blood into the heart, the latter contracts, and sends this blood, through these pulmonary arteries, into the lungs.
As the air and blood meander, side by side, through the lungs, the superabundant carbon and hydrogen of the blood combine with the oxygen of the air, forming carbonic acid gas, and water, which are thrown out of the lungs at every expiration. This is the process by which the chyle is converted into arterial blood, and the venous blood purified of its excess of carbon and hydrogen. When the blood is thus prepared, in the lungs, for its duties, it is received by the small pulmonary veins, which gradually unite, and bring the blood back to the heart, through the large pulmonary veins, marked p v, p v.
On receiving this purified blood from the lungs, the heart contracts, and sends it out again, through the aorta, to all parts of the body. It then makes another circuit through every part, ministering to the wants of all, and is afterwards again brought back by the veins to receive the fresh chyle from the stomach, and to be purified by the lungs.
The throbbing of the heart is caused by its alternate expansion and contraction, as it receives and expels the blood. With one throb, the blood is sent from the right ventricle into the lungs, and from the left ventricle into the aorta.
Every time we inspire air, the process of purifying the blood is going on; and every time we expire the air, we throw out the redundant carbon and hydrogen, taken from a portion of the blood. If the waist is compressed by tight clothing, a portion of the lungs be compressed, so that the air-vessels cannot be filled. This prevents the perfect purification and preparation of the blood, so that a part returns back to the heart unfitted for its duties. This is a slow, but sure, method, by which the constitution of many a young lady is so undermined that she becomes an early victim to disease and to the decay of beauty and strength. The want of pure air is another cause, of the debility of the female constitution. When air has been rendered impure, by the breath of several persons, or by close confinement, it does not purify the blood properly. Sleeping in close chambers, and sitting in crowded and unventilated schoolrooms, are frequent causes of debility in the constitution of young persons.
OF THE SKIN
The skin is the covering of the body, and has very important functions to perform. It is more abundantly supplied with nerves and blood-vessels than any other part; and there is no spot of the skin where the point of the finest needle would not pierce a nerve and blood-vessel. Indeed, it may be considered as composed chiefly of an interlacing of minute nerves and blood-vessels, so that it is supposed there is more nervous matter in the skin, than in all the rest of the body united, and that the greater portion of the blood flows through the skin.
The whole animal system is in a state of continual change and renovation. Food is constantly taken into the stomach, only a portion of which is fitted for the supply of the blood. All the rest has to be thrown out of the system, by various organs designed for this purpose. These organs are,—the lungs, which throw off a portion of useless matter when the blood is purified; the kidneys, which secrete liquids that pass into the bladder, and are thrown out from the body by that organ; and the intestines, which carry off the useless and more solid parts of the food, after the lacteals have drawn off the chyle. In addition to these organs, the skin has a similar duty to perform; and as it has so much larger a supply of blood, it is the chief organ in relieving the body of the useless and noxious parts of the materials which are taken for food.
Various experiments show, that not less than a pound and four ounces of waste matter is thrown off by the skin every twenty-four hours. This is according to the lowest calculation. Most of those, who have made experiments to ascertain the quantity, represent it as much greater; and all agree, that the skin throws off more redundant matter from the body, than the whole of the other organs together. In the ordinary state of the skin, even when there is no apparent perspiration, it is constantly exhaling waste matter, in a form which is called insensible perspiration, because it cannot be perceived by the senses. A very cool mirror, brought suddenly near to the skin, will be covered, in that part, with a moisture, which is this effluvium thus made visible. When heat or exercise excites the skin, this perspiration is increased, so as to be apparent to the senses. This shows the reason why it is so important frequently to wash the entire surface of the body. If this be neglected, the pores of the skin are closed by the waste matter thrown from the body, and by small particles of the thin scarfskin, so that it cannot properly perform its duties. In this way, the other organs are made to work harder, in order to perform the labor the skin would otherwise accomplish, and thus the lungs and bowels are often essentially weakened.
Another office of the skin, is, to regulate the heat of the body. The action of the internal organs is constantly generating heat; and the faster the blood circulates, the greater is the heat evolved. The perspiration of the skin serves to reduce and regulate this heat. For, whenever any liquid changes to a vapor, it absorbs heat from whatever is nearest to it. The faster the blood flows, the more perspiration is evolved. This bedews the skin with a liquid, which the heat of the body turns to a vapor; and in this change, that heat is absorbed. When a fever takes place, this perspiration ceases, and the body is afflicted with heat. Insensible perspiration is most abundant during sleep, after eating, and when friction is applied to the skin. Perspiration is performed by the terminations of minute arteries in every part of the skin, which exude the perspiration from the blood.
The skin also performs another function. It is provided with a set of small vessels, called absorbents, which are exceedingly abundant and minute. When particular substances are brought in contact with the skin, these absorbents take up some portions and carry them into the blood. It is owing to this, that opium, applied on the skin, acts in a manner similar to its operation when taken into the stomach. The power of absorption is increased by friction; and this is the reason that liniments are employed, with much rubbing, to bruises and sprains. The substance applied is thus introduced into the injured part, through the absorbents. This shows another reason for frequent washing of the skin, and for the frequent changes of the garment next the skin. Otherwise portions of the noxious matter, thrown