BY JOSEPH LAUTERER, M.D. 85 



Brisbane gardens. I found 65 per cent, of water in the fresh tea- 

 leaves. The dried leaves contain a much higher amount of 

 caffein than the dry coffee beans. From 100 grammes of dried 

 tea leaves, grown in Brisbane, I obtained 3"8 grammes of pure 

 caffein. The fresh leaves contained — water 65, tannic acid 3*5, 

 caffein 1-3, other matter 30-0. For a good cup of tea about a 

 drachm, or between 4 and 5 grammes of Chinese tea is wanted, 

 and the cup contains then just 3 grains of caffein, like the coffee 

 made from 2^ drachms of coffee beans. More than three cups 

 of such strong tea during the day might produce bad effects on 

 the heart and on the nervous system. 



Besides the caffein there were small quantities of another 

 alkaloid (isomeric with theobromine), found by Kossel in the 

 tea-leaves. [Theophyllin.) 



For the production of tea, fresh leaves of about six months' 

 growth are wanted, and therefore pruning is a prominent feature 

 in tea manufacturing. Fresh dried leaves have scarcely any 

 aroma. It must be developed by fermentation, and this involves 

 one of the drawbacks in the production. The leaves are first 

 withered for some hours in the open air, to take their stiffness 

 away and to prepare them for rolling. When they are soft 

 enough, they are rolled together by the hands of the workers, a 

 process not always connected with too much cleanliness. As 

 the moisture in the rolls cannot get away, fermentation sets in, 

 by which the aroma is produced ; w hereas the caffein does not 

 undergo any change. After some hours the rolls are broken up 

 and dried quickly and the tea is ready for packing. 



Dry tea leaves contain 10 per cent, of a special tannin. 

 According to Allen, it is thought by some authorities to be 

 identical with gallotannic acid, and by others to consist of 

 quercitannic acid. My researches show that it comes near to 

 both, but that it cannot be identified with any of them. From 

 gallotannic acid it differs by yielding a red phlobaphene 

 if boiled with dilute hydrochloric acid, and by the brown preci- 

 pitate with lead salts. From quercitannic acid it is separated 

 in giving only pyrogallol by dry distillation. Its reactions are 

 as follows : — Ferric salts, blue (purple with ammonia) ; alkalies 

 and cyanide of potassium, pink ; copper acetate, brown ; lead 

 salts, brown precipitate ; ammon. molybdate in nitric acid, 



