2. The Aromatic and Astringent drinks.
These include Tea, Coffee, Chicory, Chocolate, and Cocoa.
The following remarks on these drinks are taken from the work of Dr. Pereira.
“The peculiar flavor of tea depends upon the volatile oil, which has the taste and smell of tea. Alone, it acts as a narcotic, but when combined (as in tea) with tannin, it acts as a diuretic and diaphoretic (i. e. to promote the flow of urine and perspiration). Its astringency, proved by its chemical properties, depends upon the presence of tannin. Of this quality we may beneficially avail ourselves in some cases of poisoning, as by poisonous mushrooms, by opium, or laudanum.”
“The peculiar influence of tea, especially the green variety, over the nervous system, depends upon the vegetable oil referred to. The influence is analogous to that of foxglove; for both green tea and foxglove occasion watchfulness, and act as sedatives on the heart and bloodvessels. Strong green tea produces, on some constitutions, usually those popularly known as nervous, very severe effects. It gives rise to tremor, anxiety, sleeplessness, and most distressing feelings.”
“As a diluent and sedative, tea is well adapted to febrile and inflammatory disorders. To its sedative influence should be ascribed the relief of headache sometimes experienced.”
On this subject, Dr. Lee remarks, “Green tea undoubtedly possesses very active medicinal properties; for a very strong decoction of it, or the extract, speedily destroys life in the inferior animals, even when given in very small doses. The strongly marked effects of tea upon persons of a highly nervous temperament, in causing wakefulness, tremors, palpitations, and other distressing feelings, prove, also, that it is an agent of considerable power. It not unfrequently occasions vertigo, and sick headache, together with a sinking sensation at the pit of the stomach, shortly after eating. It is also opposed to active nutrition, and should, therefore, be used with great moderation by those who are thin in flesh. From its astringent properties it often is useful in a relaxed state of bowels.”
“We are satisfied that green tea does not, in any case, form a salubrious beverage to people in health, and should give place to milk, milk and water, black tea, milk and sugar, which, when taken tepid, form very agreeable and healthy drinks.”
Coffee. “The infusion, or decoction of coffee, forms a well known favorite beverage. Like tea, it diminishes the disposition to sleep, and hence it is often resorted to by those who desire nocturnal study. It may also be used to counteract the stupor induced by opium, alcoholic drinks, and other narcotics. In some constitutions it acts as a mild laxative, yet it is usually described as producing constipation. The immoderate use of coffee produces various nervous diseases, such as anxiety, tremor, disordered vision, palpitation, and feverishness.”
Chicory, or Succory. This is the roasted root of the Wild Endive, or Wild Succory. It is prepared like coffee, and some prefer its flavor to that of coffee.