2Ö 
RESEARCHES ON THE MANUFACTURE 
2) Crude protein suffers, in both cases, a slight diminution 
principally owing to the mechanical loss of theine and other 
nitrogenous substances. 
3) Fibre shows a small loss owing to its destruction during 
the preparation. 
4) The loss of ethereal extract is somewhat remarkable owing 
to a conversion of a part of the tannin into a form insoluble 
in ether, as a consequence, nitrogen free-extract shows a remar¬ 
kable increase. The fact that the loss of ethereal extract in 
black tea is less than in the green, indicates the formation of 
organic acids 1 and other components soluble in ether during 
the fermentation of the leaves. 
5) Ash too suffers, in both cases, a slight loss, owing to the 
mechanical loss of the sap in which it is partly dissolved. 
6) A trifling loss of theine may also be attributed to the same 
source of loss rather than to its sublimation during firing. 
7) The destruction chiefly concerns tannin, of which disap¬ 
pear from 100 parts of dry matter applied 2,41% in green tea, 
and 8.23% in black. It is destroyed chiefly during the process 
of rolling and drying ; and in the case of black tea, fermenting 
is the most energetic agent for the destruction of tannin. It 
is, indeed, true that it is very prone to alterations, since I 
have found, that even during the mere drying of tea leaves 
in the sun, a slight, but appreciable quantity of tannin is dest¬ 
royed. 2 3 
8) Extractive matter shows a noticeable enhancement in 
the case of green tea, and a somewhat remarkable dimi¬ 
nution in that of black. According to the investigations 
of various authors 5 green tea generally contains more soluble 
substances than black. This is most probably owing to the 
conversion of large quantities of soluble tannin into insoluble 
1 I found a minute quantity of a volatile acid in black tea though I failed 
to identify its nature. 
2 From 100 parts of the tannin, 97,70 parts were found in the leaves dried 
in the sun. 
3 See König’s Nahrungsmittel. Vol. II. 2. edition, p. 618-619. 
