THEINE. The properties of tea depend chiefly on the presence of tannin, of a volatile oil, and of a principle called theine (C8H5N20g), which has been found to be identical with caffeine, and is a salifiable base. It may be obtained in white silky needles ; has a mild, bitter taste ; is soluble in hot, but sparingly so in cold water and alcohol. It has astringent and moderately excitant properties, chiefly affecting the nervous system, producing some degree of exhilaration, and of refreshmeut after fatigue. Its effects are well seen in the wakefulness produced. But it is thought by some writers to act as a sedative on the heart and blood-vessels ; or, as Dr. 13illing explains it, tea and coffee are sedatives, and relieve the stnpor produced by stimulants or the drowsiness of fatigue, or other plethora, only by counteracting the plethoric state of the brain, induced by the continued stimulation of action, — thus merely restoring the brain to its normal state. .Liebig
(Anim. Chem. p. 179) has suggested that theine, as an ingredient of diet, may be useful in contri buting to the formation of taurine, a compound peculiar to bile. Besides being useful as a diluent, it may often be prescribed as an agreeable and refreshing beverage ; in some cases, especially when made strong, acting as an excitant, and at other times producing sedative and calming effects. Tea is very extensively cultivated in Kangra valley and Kullu, in Assam, and on the Neilgherries. Coffee leaves are infused in the same manner as the tea leaf, and the beverage coffee-tea is said to be in common use in Sumatra. The coffee decoc tion or new tea are valuable in opium-poisoning.