RECAPITULATION OF PROCESSES. 303 



a volatile oil : and, as in tobacco and wine, the 

 odoriferous principle of tea may be susceptible of 

 much variety by the management of this fermenta- 

 tion. It is, moreover, a fact, that black tea fur- 

 nishes a greater variety of flavours than green tea. 

 Strength or body seems to depend on the amount 

 and quality of the astringent principle, or tannin.* 



Now the difference of black and green tea, as 

 classes, having been traced to difference of mani- 

 pulation, it may be desirable here, in conclusion, 

 to recapitulate concisely the different processes to 

 which these teas are submitted. 



The leaves of black tea are exposed to the sun 

 and air on circular trays, and treated as hay, 

 during which an incipient saccharine fermentation 

 is supposed to take place in conjunction with a 

 volatile oil. Various modifications of flavour are 

 thus produced by the management of this fermenta- 

 tion ; a loss of tannin takes place by the con- 

 version of a part of the tannic acid into sugar. 



* In conclusion it may be asked : — 



1. If the distinctive character of black tea be the result of 

 fermentation, may not some new principle be found in the leaf, 

 analogous to nicotina in tobacco, which was not present pre- 

 viously to fermentation ? 



2. Whether the same or any other analogous principle be 

 found in green tea after desiccation, which was not previously 

 present ? 



3. What is the nature of the grey or blue colouring matter 

 of green tea resembling the bloom on some fruits, when pro- 

 duced naturally in the regular course of manipulation ? 



4. Does hay contain any product not found in grass ? 



