In the year 1821, several chemists isolated from coffee a bitter principle, of peculiar properties, which was named caffein. In 1827, the same substance was found to occur in tea. Numerous analysis show that there are between one and two per cent of caffein in coffee, and between three and six percent in tea. Later investigations have shown that caffein belongs to the vegetable poisons, and that its poisonous action is very strong. Among the medical properties of caffein are the following, "in doses of three to five grains, it produces a peculiar wakefulness--after a dose of twelve grains, it produces intense physical restlessness and mental anxiety. Upon the muscles it acts as a powerful poison--it is used in medicines as a brain and heart stimulant."[A] Fatal cases of poisoning are also on record. [Footnote A: U. S. Dispensatory, 17th ed., pp. 278 and 279.] Caffein is not in any sense a food, but, as a stimulant, must be classed with tobacco, opium and other similar substances. Owing to its action on the heart and circulation, the body becomes heated, and in that sense a solution of caffein is a "hot drink." The use of tea and coffee in health is now generally condemned by the best informed persons in and out of the medical profession. Dr. W. Gilman Thompson says, "The continuance of the practice of drinking coffee to keep awake soon results in forming a coffee or tea habit, in which the individual becomes a slave to the beverage. * * * Muscular tremors are developed, with nervousness, anxiety, dread of impending evil, palpitation, heartburn, dyspepsia and insomnia. * * * It produces great irritability of the whole nervous system and one may even overexcite the mind."[A] While it is true that one cup of coffee or tea does not contain enough caffein to injure the system, yet the continual taking of these small doses results in a weakening of the whole system, that frequently leads to premature death. [Footnote A: Practical Dietetics, p. 199.] The U. S. Consular and Trade Report for January, 1906,[A] warns against the use of coffee in the following words, "The important connection between consumption of coffee and epilepsy which deserves to be known everywhere, serves as a warning to be extremely careful with coffee made of beans containing caffein, and at any rate, children should be deprived of it entirely, otherwise their health will be exposed to great danger." [Footnote A: Page 249.] Besides caffein, both tea and coffee contain an astringent known as tannic acid. In coffee this substance is present only in small quantity, but in tea from four to twelve per cent occurs. Tannic acid is the substance found in oak bark, and has the property of making animal tissues hard--that is, makes leather of them. The habitual tea drinker subjects the delicate lining of the stomach and intestines to the action of this powerful drug.