300 FLAVOUR MODIFIED 



leaves, resembling the bloom on some fruits, is due 

 to a rapid process of drying, in consequence of a 

 free admission of light and air to every part of the 

 leaves while yet moist, and exposed to the action 

 of a moderate temperature. 



If the aroma of tea be not inherent in the plant, 

 but generated during the process of manipulation, 

 then that change which is effected in black tea by 

 spontaneous heating, as in hay or tobacco, may in 

 green tea, like the aroma of coffee, be elaborated by 

 artificial heat by a process analogous to fermenta- 

 tion, as surmised by Von Essenbeck. 



Hitherto, in tracing the causes of difference be- 

 tween black and green tea, I have endeavoured to 

 direct my investigations mainly to colour. Flavour 

 obviously depends on those general laws which 

 govern the odorous principle of all vegetable pro- 

 ductions. Some are the product of the plant itself; 

 others are generated by various processes of mani- 

 pulation. Thus, on what rests the characteristic 

 difference of flavour between black and green tea, 

 with all the modifications and varieties peculiar to 

 each class, we may not, in our present state of in- 

 formation, be able satisfactorily to explain. Nor 

 can anything short of a local examination of the 

 tree in the several districts wherein it is grown, 

 together with a chemical analysis of the leaf, in its 

 fresh as well as its manipulated state, be deemed 

 sufficient to satisfy any scientific research on that 

 subject. It has been demonstrated, however, that 



