But little drink should be taken, while eating, as it dilutes the gastric juice which is apportioned to each quantity of food as it enters the stomach. It is better to take drink after the meal is past.
Extremes of heat or cold are injurious to the process of digestion. Taking hot food or drink, habitually, tends to debilitate all the organs thus needlessly excited. In using cold substances, it is found that a certain degree of warmth in the stomach is indispensable to their digestion; so that, when the gastric juice is cooled below this temperature, it ceases to act. Indulging in large quantities of cold drinks, or eating ice-creams, after a meal, tends to reduce the temperature of the stomach, and thus to stop digestion. This shows the folly of those refreshments, in convivial meetings, where the guests are tempted to load the stomach with a variety, such as would require the stomach of a stout farmer to digest, and then to wind up with ice-creams, thus destroying whatever ability might otherwise have existed, to digest the heavy load. The fittest temperature for drinks, if taken when the food is in the digesting process, is blood heat. Cool drinks, and even ice, can be safely taken at other times, if not in excessive quantity. When the thirst is excessive, or the body weakened by fatigue, or when in a state of perspiration, cold drinks are injurious. When the body is perspiring freely, taking a large quantity of cold drink has often produced instant death.
Fluids taken into the stomach are not subject to the slow process of digestion, but are immediately absorbed and carried into the blood. This is the reason why drink, more speedily than food, restores from exhaustion. The minute vessels of the stomach inhale or absorb its fluids, which are carried into the blood, just as the minute extremities of the arteries open upon the inner surface of the stomach, and there exude the gastric juice from the blood.
When food is chiefly liquid, (soup, for example,) the fluid part is rapidly absorbed. The solid parts remain, to be acted on by the gastric juice. In the case of St. Martin,[F] in fifty minutes after taking soup, the fluids were absorbed, and the remainder was even thicker than is usual after eating solid food. This is the reason why soups are deemed bad for weak stomachs; as this residuum is more difficult of digestion than ordinary food. In recovering from sickness, beef-tea and broths are good, because the system then demands fluids to supply its loss of blood.
Highly-concentrated food, having much nourishment in a small bulk, is not favorable to digestion, because it cannot be properly acted on by the muscular contractions of the stomach, and is not so minutely divided, as to enable the gastric juice to act properly. This is the reason, why a certain bulk of food is needful to good digestion; and why those people, who live on whale oil, and other highly-nourishing food, in cold climates, mix vegetables and even sawdust with it, to make it more acceptable and digestible. So, in civilized lands, bread, potatoes, and vegetables, are mixed with more highly-concentrated nourishment. This explains why coarse bread, of unbolted wheat, so often proves beneficial. Where, from inactive habits, or other causes, the bowels become constipated and sluggish, this kind of food proves the appropriate remedy. One fact on this subject is worthy of notice. Under the administration of William Pitt, for two years or more, there was such a scarcity of wheat, that, to make it hold out longer, Parliament passed a law, that the army should have all their bread made of unbolted flour. The result was, that the health of the soldiers improved so much, as to be a subject of surprise to themselves, the officers, and the physicians. These last came out publicly, and declared, that the soldiers never before were so robust and healthy; and that disease had nearly disappeared from the army. The civic physicians joined and pronounced it the healthiest bread; and, for a time, schools, families, and public institutions, used it almost exclusively. Even the nobility, convinced by these facts, adopted it for their common diet; and the fashion continued a long time after the scarcity ceased, until more luxurious habits resumed their sway. For this reason, also, soups, gellies, and arrow-root, should have bread or crackers mixed with them. We thus see why children should not have cakes and candies allowed them between meals. These are highly-concentrated nourishments, and should be eaten with more bulky and less nourishing substances. The most indigestible of all kinds of food, are fatty and oily substances; especially if heated. It is on this account, that pie-crust, and articles boiled and fried in fat or butter, are deemed not so healthful as other food.
The following, then, may be put down as the causes of a debilitated constitution, from the misuse of food. Eating too much, eating too often, eating too fast, eating food and condiments that are too stimulating, eating food that is too warm or too cold, eating food that is highly-concentrated, without a proper admixture of less nourishing matter, and eating food that is difficult of digestion.
FOOTNOTE:
[F] The individual here referred to,—Alexis St. Martin,—was a young Canadian, of eighteen years of age, of a good constitution, and robust health, who, in 1822, was accidentally wounded by the discharge of a musket, which carried away a part of the ribs, lacerated one of the lobes of the lungs, and perforated the stomach, making a large aperture, which never closed; and which enabled Dr. Beaumont, (a surgeon of the American army, stationed at Michilimackinac, under whose care the patient was placed,) to witness all the processes of digestion and other functions of the body, for several years. The published account of the experiments made by Dr. B., is highly interesting and instructive.