OF BLACK TEA. 289 



solution of the distinctive character and qualities 

 of black tea may be found. I employ the phrase- 

 ology of Liebig that the coincidence may appear 

 the more striking ; and also that the opinion now 

 given may derive countenance from his authority. 

 Newly gathered leaves exposed to sun and air soon 

 begin to suffer change ; and all organic substances 

 during this state of change absorb oxygen from the 

 atmosphere. " The green resinous principle of the 

 leaf disappears," and in leaves containing tannin, as 

 tea leaves, " red or brown colouring matters are 

 formed ; the tannic acid disappears, and is replaced 

 by sugar." Thus is the loss of tannin in black tea 

 accounted for ; and the red colouring matter of the 

 leaf, as well as the red infusion, explained.* 



* It is satisfactory to state, that the presence of sugar in the 

 teas of commerce was proved by analysis, obligingly undertaken 

 by Mr. Warington at my request, in the early part of the year 

 1846. It was found both in black and green tea in large quan- 

 tities, but not a trace of starch in either. My expectation was, 

 that the tannic acid might be found converted into starch in 

 green tea, and into sugar in black. In this expectation I was 

 disappointed ; and now I must leave all further research in the 

 hands of the chemist. Could the quantity of sugar be accu- 

 rately measured, it might lead to further and more certain 

 results ; but it appears that the power of accurately measuring 

 minute quantities of saccharine matter in vegetable substances 

 is still a desideratum in chemistry. It may be surmised, how- 

 ever, that a larger quantity is elaborated in black tea than in 

 green ; and that the excess is carried off by fermentation of the 

 saccharine juices, during the manipulation of the leaves pre- 

 viously to roasting ; and in some cases, as in the Hong Moey 

 teas, also during the manipulation after roasting and rolling while 



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