1892 Drinks of the world

DRINKS.

246

Of which Home Consumpt. ...

183,000,00a

185,250,000

187,940,000

Export

35,200,000

39,500,000

36,107,000

...

...

There are three active substances in tea, which we should do well to notice : Volatile Oil, Theine, and Tannin. The volatile oil can be distilled by ordinary process, and it contains the aroma and flavour of tea in per- Its action on the human body is not thoroughly known, with the exception that it is injurious in a greater or less degree. The Chinese are well aware of the fact, and will rarely use tea until it is a year old, thus allowing some of it to evaporate, and it is prob- ably owing to this oil that tea-tasters (who taste as much by smell as by palate) are subject to attacks of headache and giddiness. Theine is the principle which gives to tea its power of lessening the waste of the tissues in the human body, and, when separated from the decoction, it forms an alkaloid having no smell, a slightly bitter taste, and is composed of colourless crystals. It is also an active agent in Mate or Paraguay tea, In coffee (when it is called caffeine, although identical In substance), in Guarana, which is used as coffee in Brazil, and in the Kola Nut of Africa. The third product, tannin, gives roughness of flavour to the tea, and is particularly developed by allowing the Infusion to stand a long time. It is harmless ; at least, its combination In tea has never been found to be hurtful; Its presence Is at once shown by dropping some tea on the clean blade of a fection.