The stomach is the most important organ of digestion. It has three coats; that which has most to do with digestion is the mucous coat, which lines it; this coat is supposed to furnish, by its glands, what is called gastric juice, which is the principal agent of digestion. The stomach is abundantly supplied with nerves, and holds a very powerful sway over the whole nervous system—so that, when the stomach is under the influence of disease, either acute or chronic, the whole system is immediately in a state of suffering. To secure, then, a healthy organization, the stomach must be kept in health.
THE LIVER.
This organ is also essential to digestion; it furnishes the bile; it is the largest gland in the body, and its office seems to be to gather from and carry out of the system substances which, if retained, might prove hurtful. When the liver is inactive, we have what is called the jaundice; the liver failing to take up from the system that substance which forms the bile. When this is the case, a yellow substance is found diffused throughout the whole body, and it exhibits a yellow tinge. The bile, when properly secreted and discharged, meets the contents of the stomach as discharged into that part of the bowels nearest the stomach, and is there supposed to assist in the process of separating the nutritious part of the contents from the refuse, which is to pass off by the bowels; but its more important office is, doubtless, to rid the passage of the refuse, or the fæces, by evacuation. The bile seems to be nature’s appropriate stimulus to the bowels, without which costiveness, and other irregularities, are likely to ensue.
THE BOWELS.
The bowels contain the absorbent vessels, which take up the nutritious part of the food and carry it into the circulation of the blood, for the support of the system; they also convey the refuse part of the food out of the body.
MASTICATION.
Mastication, or chewing, is the first step in the process of digestion. When food is taken, it should be thoroughly masticated, before it is suffered to pass into the stomach, or it is unprepared for the action of the gastric juice. Besides this, the action of chewing causes the food to be mixed with the saliva, which is an important item in the preparation of it for the action of the stomach and its juice. The food should be taken with sufficient moderation, to give time for the process of mastication, and the discharge of saliva from the glands of the mouth. Eating fast, or even talking while chewing, besides its incongruity with politeness and good breeding, is directly at war with thorough mastication.
Many persons seem to think, that hurrying their meals to save time is economy; their business drives them, and they drive their time of meals into the smallest possible compass. This is miserable economy; for, when they hurry down their food, half chewed and half moistened with saliva, it deranges the process of digestion throughout, and, as a consequence, the food not only sits bad on the stomach, and in time causes dyspepsia, but fails to accomplish the sole object of taking it—the nourishment of the body. In order to derive nourishment from food, it must be well digested; hence it must be well masticated. When, therefore, we hurry our eating, we hasten our steps on the wrong road; time curtailed in eating, is worse than hiring money at three per cent. a month. If we cannot spare time to eat, we had better not eat at all; this idea cannot be too deeply impressed upon the minds of all. Thousands, by this kind of careless and reckless eating, have, found themselves the victims of dyspepsia, and all its attendant train of evils; the digestive organs may bear the abuse awhile, without giving many signs of trouble, but the penalty of that broken law must sooner or later come; and it may come in the form of a broken constitution.
CHYMIFICATION.
Chymification, or the transformation of food into chyme, is the most important step in the process of digestion. The food, after mastication, passes into the stomach; here it is formed into a homogenous mass, partly fluid and partly solid, which is called chyme. What is the exact philosophy of this process, has been a matter of some discussion, into which it is not necessary now to enter; nor is it yet satisfactorily settled, so as to admit of any definite instructions being given. The theory which is now generally received, respecting the manner in which the stomach acts upon food, is, that the gastric juice possesses a solvent power, by which the food becomes reduced to a uniform mass; the solvent power of the gastric juice is very great in a healthy, vigorous stomach, but varies in strength according to the energy of that organ. The solvent power of the gastric juice is evidently controlled by the vital principle of life; while the gastric juice of a healthy stomach acts vigorously upon the hardest kinds of food; yet sometimes, when it comes in contact with anything possessed of the principles of life, its power is stayed—worms, while living, are not affected by it, but when destroyed, are often digested. The gastric juice also possesses the property of coagulating liquid albuminous substances; the stomach of the calf is used for this purpose, by the dairy-woman, in making cheese; and when the infant throws up its milk, because the stomach is too full, that milk will be more or less curdled—and instead of considering this curdling an indication of disease, it should be accounted a symptom of a good, healthy stomach.