DIGESTION

AND

INDIGESTION.

"But (except

Amid the mingling mass of fish and fowl,
And boiled and baked, you hesitate by which
You sunk oppressed, or whether not by all),
Taught by experience, soon you may discern
What pleases, what offends."

THE smallest particle of matter at variance with the springs of animal existence, cannot remain in the system without injury. It is to this cause that diseases in general may be traced. The human body is so constituted, that its powers of action and resistance act reciprocally: neither the one nor the other can permanently obtain the ascendancy, and the maintenance of the balance between them results in that happy state called health. All men, therefore, ought to have clear general notions on the subject of digestion. A minute knowledge of this important branch of the science of health is hardly attainable, by the general reader,

I

and would prove but of very little use were it attained. It is the office of food to supply the continual waste of the body. When received into the stomach, it is soon converted into a substance technically called chyme: solution is the name given to this part of the digestive process. When the chyme has attained a suitable consistency, it passes into the intestines, where the nutritious portion is separated, and, being formed into chyle, passes onward, till transformed into blood. A complete explanation of the mechanism of nutrition, however, cannot be given, because we cannot ascertain precisely how each organ operates upon the aliment with which it is brought in contact, nor in what manner the ultimate absorption of the nutriment is effected, so as to render it in fact an integral portion of the body. The sensation denominated hunger, is, in reality, the irritation caused by the gastric juice, a fluid exuding from the sides of the stomach, which experiments have proved to be the essential means of digestion.

When the stomach is empty, this fluid acts upon the nerves of that organ, and thus produces the sensation of hunger. Digestion is promoted by several other fluids provided for that provided for that purpose, as saliva, intestinal bile, and pancreatic. This important operation consists of two distinct processes, solution and assimilation. Solution, as I have

already stated, takes place in the stomach. Assimilation follows, and consists in the separation of the nutritious portions of the chyme, which in the form of chyle are taken up by the absorbent vessels and united with the blood. Thus we see that by assimilation the aliment is (if I may so say) animalized; on which account animal food has been held to be more digestible than vegetable, bearing as it does a closer analogy to our own nature. It is an error to suppose that the more we eat the sooner shall we be refreshed. Beyond certain limits, the result will be the very reverse; for, if the powers of digestion be overtasked, a sense of oppression, instead of refreshment, will take place; and, what is worse, some portion of the surplus food will probably remain unassimilated, in which case derangement will ensue, and the benevolent purposes of nature be frustrated. Many persons suppose that the ease of the stomach is adequately consulted by avoiding food of a coarse description, and such as in itself is acknowledged to be difficult of digestion. This is an egregious error. If the digestive organs require a diet expressly prepared for them, it is because we have perverted them. The hardy countryman digests all sorts of food, however condensed and solid, from many of which the stomach of the luxurious citizen recoils. What is the cause of so strange a difference? The cause is in the respec

tive habits of the individuals. The countryman takes plenty of active exercise, rises with the sun, retires early, breathes a pure air, and leads a life of undeviating regularity. The bon-vivant of the City is inactive, or at least substitutes passive for active exercise, lies till noon, goes to bed when the rustic is getting up, breathes a contaminated atmosphere, often aggravated by the application of artificial heat.

Spices and savoury stimulants are hindrances to digestion. The reason is, that they stimulate the bowels too much, causing the food to pass unassimilated through the alimentary canal at too rapid a rate to permit the absorbents to perform their proper office. Hence frequent interruptions of tranquil repose;

"Dreams are fed

From rising fumes of indigested food.”—DRYDEN.

Mastication helps digestion very materially. It was a saying with the ancients, that he who did not chew well was an enemy to his own life. The intimate connection between digestion and the process called sanguification, which means the conversion of the food into blood: the due regulation-nay, the perfect unison of the organs by which it is effected, should be an object of our closest attention. Medical authorities differ in

opinion as to the primary cause of digestion. Hippocrates and Empedocles held that it was

disciples inferred that Grew and Santarelli

putridity. Galen and his it was occasioned by heat. were of opinion that the spirits accruing from the nerves of the stomach, were the means of digestion. Pringle and Macbride agreed in concluding it to be a fermentative process. Cheselden attributed it to some unknown menstruum. Spallanzani and Reaumur proved that menstruum to be the gastric juice.

In whatever the digestive process may consist, it is clear that the aid of heat, moisture, and motion, is necessary to its accomplishment.

Enough, too, has been ascertained on the subject for the purposes of health. Diseases may for the most part be cured in their incipient stages, by the judicious application of aperients; for regularity in relieving the bowels lies at the very foundation of health and long life.