In some cases, however, it produces a rush of blood to the head, and should be at once discarded. At the close of a full meal it hinders digestion, and at night produces wakefulness. In youth, when the vital powers are strong, and the functions of nature prompt in rallying from fatigue, it is not needed, and may be injurious in stimulating a sensitive organization.
Tea possesses an active principle called theine. When used moderately, its effects are similar to those of coffee, except that it exerts an astringent action. It contains tannin, which, if the tea is strong, coagulates the albumen of the food—tans it—and thus delays digestion. In excess, tea causes nervous tremor, disturbed sleep, palpitation of the heart, and indigestion. [Footnote: Tea and coffee should be made with, boiling water, but should not be boiled afterward. During the "steeping" process, so customary in this country, the volatile aroma is lost and a bitter principle extracted. In both England and China it is usual to infuse tea directly in the urn from which it is to be drawn. The tannin in tea is shown when a drop falls on a knife blade. The black spot is a tannate of iron—a compound of the acid in the tea and the metal.] (See p. 322.)
Chocolate contains much fat, and also nitrogenous matter resembling albumen. Its active principle, theobromine, [Footnote: It is said that Linnæus, the great botanist, was so fond of chocolate that he named the cocoa tree "Theobroma," the food of the gods.] has some of the properties of caffeine and theine.
THE COOKING OF FOOD breaks the little cells, and softens the fibers of which it is composed. In broiling or roasting meat, it should be exposed to a strong heat at once, in order to coagulate the albumen upon the outside, and thus prevent the escape of the nutritious juices. The cooking may then be finished at a lower temperature. The same principle applies to boiling meat. In making soups, on the contrary, the heat should be applied slowly, and should reach the boiling point for only a few moments at the close. This prevents the coagulation of the albumen. Frying is an unhealthful mode of cooking food, as thereby the fat becomes partially disorganized.
RAPID EATING produces many evil results. 1. There is not enough saliva mixed with the food; 2. The coarse pieces resist the action of the digestive fluids; 3. The food is washed down with drinks that dilute the gastric juice, and hinder its work; 4. We do not appreciate the quantity we eat until the stomach is overloaded; 5. Failing to get the taste of our food, we think it insipid, and hence use condiments that overstimulate the digestive organs. In these various ways the appetite becomes depraved, the stomach vexed, the system overworked, and the foundation of dyspepsia is laid. [Footnote: When one is compelled to eat in a hurry, as at a railway station, he would do well to confine himself principally to meat; and to dilute this concentrated food with fruit, crackers, etc., taken afterward more leisurely.] (See p. 324.)
THE QUANTITY AND QUALITY OF FOOD required vary with the age and habits of each individual. The diet of a child [Footnote: In youth, repair exceeds waste; hence the body grows rapidly, and the form is plump. In middle life, repair and waste equal each other, and growth ceases. In old age, waste exceeds repair; hence the powers are enfeebled and the skin lies in wrinkles on the shrunken form.] should be largely vegetable, and more abundant than that of an aged person. A sedentary occupation necessitates less food than an outdoor life. One accustomed to manual labor, on entering school, should practice self-denial until his system becomes fitted to the new order of things. He should not, however, fall into the opposite error. We read of great men who have lived on bread and water, and the conscientious student sometimes thinks that, to be great, he, too, must starve himself. [Footnote: As Dr. Holland well remarks, the dispensation of sawdust has passed away. If we desire a horse to win the race, we must give him plenty of oats.] On the contrary, many of the greatest workers are the greatest eaters. A powerful engine needs a corresponding furnace. Only, we should be careful not to use more fuel than is needed to run the machine. (See p. 325.)
The season should modify our diet. In winter, we need highly carbonaceous food, plenty of meat, fat, etc.; but in summer we should temper the heat in our corporeal stoves with fruits and vegetables.
The climate also has its necessities. The inhabitants of the frigid north have an almost insatiable longing for fat. [Footnote: Dr. Hayes, the arctic explorer, says, that the daily ration of the Esquimaux was from twelve to fifteen pounds of meat, one third being fat. On one occasion, he saw a man eat ten pounds of walrus flesh and blubber at a single meal. The low temperature had a remarkable effect on the members of his own party, and some of them were in the habit of drinking the contents of the oil kettle with evident relish. Other travelers narrate the most incredible stories of the voracity of the inhabitants of arctic regions. Saritcheff, a Russian admiral, tells of a man who in his presence ate, at a meal, a mess of twenty-eight pounds of boiled rice and butter, although he had already partaken of his breakfast. Captain Cochrane further adds, in narrating this statement, that he has himself seen three of the savages consume a reindeer at a sitting.] Thus, in 1812, when the Allies entered Paris, the Cossacks drank all the oil from the lamps, and left the streets in darkness. In tropical regions, a low, unstimulating diet of fruits forms the chief dependence. [Footnote: A natural appetite for a particular kind of food is an expression not only of desire, but of fitness. Thus the craving of childhood for sugar indicates a need of the system. It is questionable how far it is proper to force or persuade one to eat that which he disrelishes, or his stomach loathes. Life within is linked with life without. Each organ requires its peculiar nutriment, and there is often a peculiar influence demanded of which we can have no notice except by natural instinct. Yet, as we are creatures of habit and impulse, we need common sense and good judgment to correct the too often wayward promptings of an artificial craving.]
WHEN FOOD SHOULD BE TAKEN.—On taking food, the blood sets at once to the alimentary canal, and the energies are fixed upon the proper performance of this work. We should not, therefore, undertake hard study, labor, or exercise directly after a hearty meal. We should give the stomach at least half an hour. He who toils with brain or muscle, and thus centers the blood in any particular organ, before eating should allow time for the circulation to become equalized. There should be an interval of four to five hours between our regular meals, and there should be no lunching between times. With young children, where the vital processes are more rapid, less time may intervene. As a general rule, nothing should be eaten within two or three hours of retiring. (See p 336.)
HOW FOOD SHOULD BE TAKEN.—A good laugh is the best of sauces. The mealtime should be the happiest hour of the day. Care and grief are the bitter foes of digestion. A cheerful face and a light heart are friends to long life, and nowhere do they serve us better than at the table. God designed that we should enjoy eating, and that, having stopped before satiety was reached, we should have the satisfaction always attendant on a good work well done.