FACTITIOUS COLOURING. 243 



for the same purpose ; and it obviously may be 

 surmised, that the freer admission of light and air 

 may work very considerable chemical effects, alto- 

 gether sufficient to account for the different results 

 in these two processes. 



So far as the characteristic colour of green tea is 

 concerned, the mode of producing it has here been 

 explained and established. If factitious means are 

 now generally or almost universally adopted to 

 imitate or to increase the effect of the natural 

 colour, it may be considered as a great and novel 

 abuse, and ought to be discouraged by brokers and 

 dealers. It is injurious to flavour. Whether the 

 Chinese do employ colouring matter or not for the 

 teas they use themselves, there can be no doubt 

 that the bulk of the Hyson teas of the present clay, and, 

 indeed, all descriptions of green tea, are now glazed 

 to a degree that would have insured their rejection 

 by the agents of the East India Company during the 

 existence of their charter. Mr. Waring ton, che- 

 mical operator of Apothecaries' Hall, published an 

 interesting paper in the " Memoirs of the Chemical 

 Society" read February 1844, proving by chemical 

 examination and analysis the fact, that the Chinese 

 green teas are artificially coloured with ferrocyanide 

 of iron or prussian blue, and sulphate of lime or 

 gypsum — the greater part with the two combined, 

 some few with sulphate of lime only, and some 

 with a yellow or orange-coloured vegetable sub- 



R 2 



