The tannin found in tea does not differ from that found in oak and other barks which the tanners use to convert the raw hides of animals into leather. It is a powerful astringent, which accounts for some of the peculiar physical evils to which confirmed tea drinkers are subject.
Theine does not differ essentially from Cocaine (see p. 223). They both produce exaltation of the nervous system and increased powers of physical endurance. The brain is largely influenced in its functions, and long periods of wakefulness are induced. Continued use of strong infusions of either coca or tea result in great disturbance of nervous centers and functional offices, and either will produce fatal results by persistent use of inordinate quantities.
A cup of tea as served at tea tables contains usually only a trace of the alkaloidal principle, but infinitesimal quantities are capable of exerting baneful effects upon some tea drinkers….Poisons act in a variety of ways, some slowly, and without producing pain; others act violently, and with speedy, fatal results. Inasmuch as we do not observe a very large number of clearly proved cases of acute poisoning by tea, we must conclude that it is characteristically a slow poison, and also that its influence is unlike in different individuals….Four or six cups of tea, however, taken during each twenty-four hours, will in time produce tea poisoning, and greater or less evil effects.
Tea is well enough, when its use is kept under absolute, intelligent control; but if it becomes master in any case, then it must be promptly abandoned, for danger attends the intemperate tea drinker every hour of his life. Those advanced in life crave its stimulating effects, and it is well for them to use it in moderation; but the young should abstain from it entirely.—Abridged from "Tea Poisoning," by DR. NICHOLS, in Popular Science News, December, 1887.
CAUSES AND EFFECTS OF INDIGESTION (p. l72).—When a light breakfast is eaten, a solid meal is requisite in the middle of the day. If the digestive organs are left too long unemployed, they secrete an excess of mucus, which greatly interferes with their normal functions. One meal has a direct influence on the next; and a poor breakfast leaves the stomach over-active for dinner. This is the secret of much excess in eating. The point to bear in mind is that not to eat a sufficiency at one meal makes you too hungry for the next; and that when you are too hungry, you are apt to overload the stomach, and to give the gastric juices more to do than they have the power to perform.
To eat too often, and to eat irregularly, are other sources of indigestion. People who dine at uncertain hours, and eat one meal too quickly on the last, must expect the stomach to retaliate in the long run. A very fruitful cause of dyspepsia is imperfect mastication. We remember one old gentleman who used always to warn young people on this point by saying: "Remember you have no teeth in your stomach." Nervous people nearly always eat fast, and as nearly always are the victims of nervous irritability, produced by dyspepsia….To sit much in a stooping posture interferes with the stomach's action. Well-marked dyspepsia has been traced to sitting immediately after dinner in a low armchair, so that the body was curved forward, and the stomach compressed….
The skin, core, and kernels of fruit should be avoided. Some people are not able to digest raw apples; and dyspepsia has been sometimes greatly aggravated by eating pears. The latter fruit, in its ripest state, contains an abundance of gritty material, which, as it can not be separated in the mouth, on being swallowed irritates the mucous membrane….
Of food itself, bear in mind that hot meat is more digestible than cold; the flesh of full-grown animals than that of young ones; that land birds are more digestible than waterfowl; wild animals than domestic ones; and that in game, newly killed birds are easier of digestion than those which have been kept a long time.—Hints to Dyspeptics, Chambers's Journal.
HOW FOOD DEVELOPS ENERGY (p. 173).—It may appear strange that the small amount of food we eat should suffice to carry our large and bulky bodies through all the varied movement of the day. But this difficulty disappears at once, when we recollect how large an amount of dormant energy can be laid by in a very small piece of matter. A lump of coal no bigger than one's fist, if judiciously employed, will suffice to keep a small toy engine at work for a considerable time. Now, our food is matter containing large amounts of dormant energy, and our bodies are engines so constructed as to utilize all the energy to the best advantage. A single gramme of beef fat if completely burned (that is, if every atom unites with oxygen), is capable of developing more than 9,000 heat units; and each heat unit, if employed to perform mechanical work, is capable of lifting a weight of one gramme to a height of 424 meters; or, what comes to the same thing, 424 grammes to a height of one meter. Accordingly, the energy contained in one gramme of beef, and the oxygen with which it unites, would be sufficient to raise the little bit of fat itself to a height of 3,816 kilometers, or almost as high as the distance from London to New York.— GRANT ALLEN in "Why do we Eat our Dinner?"
Danger of Too High Pressure.—A prudent fire engineer, when his water hose is old and weak, would not try to force as much water as he could into it. No; to prevent a rupture he would work it at a low pressure. But men seldom think of carrying out the same simple mechanical principle when there is reason to believe that the vessels of the brain are getting weak and brittle. They eat and drink just as much as they feel inclined to, and sometimes a little more. With a good digestion, nearly all they consume is converted into blood, to the yet further distention of vessels already over-distended. This high-pressure style of living produces high-pressure results. Its effects were painfully illustrated by the death of Charles Dickens. The brain work he performed was immense; he lived generously, taking his wine as he did his meat, with a liberal hand. He disregarded the signs of structural decay, forcing his reluctant brain to do what it had once done with spontaneous ease, until all at once, under a greater tension than ordinary, a weak vessel gave way, flooding the brain with blood.—J. R. BLACK, M.D., in "Apoplexy," Popular Science Monthly, April, 1875.