22 
RESEARCHES ON THE MANUFACTURE 
Thus, we see that the fermentation went on first quickly, 
afterwards more slowly, and arrived at the maximum after 
hours. I have observed that the career of the fermentation 
and the alteration of the colour proceed simultaneously. At 
first, the leaves were, of course, quite green, but they became 
more and more brownish, and after 2^ hours the whole mass 
was completely brown, when the temperature attained the 
maximum. Judging from the appearance of the leaves, the 
proper degree of the fermentation was already attained after 
70 minutes, hence in practice the fermentation is interrupted, 
when it has run about midway. 
Sunning. For this purpose, the properly fermented leaves 
are thinly spread upon a straw mat or tanned thick paper and 
exposed to the sun. This operation is said to interrupt the 
career of fermentation. In reality, however, a slow fermenta¬ 
tion still takes place inasmuch as the greenish colour of the 
leaves becomes gradually blackish. During this operation, 
the leaves are collected and re-spread frequently, so that they 
shall be uniformly affected by the sun. This operation is 
considered as sufficient, when all the leaves assume an uniform 
blackish tint. The duration of sunning is, of course, depen¬ 
dent upon the thermal intensity of the sun and the nature of 
the leaves. After the process, the leaves are generally once 
more rolled. With bright sunshine, an hour, or even less, is 
sufficient. In rainy or cloudy weather a furnace answers the 
purpose. 
Firing. This is the operation to which the sunned leaves 
are subjected. The furnace most commonly employed, con¬ 
sists of a cylindrical bamboo basket open at both ends and 
narrow in the middle, somewhat in the form of a lady’s corset. 
It is about 2.2 shaku in height and 2 shaku in diameter. The 
narrow part of the basket is lined with a piece of a bamboo 
stick which acts as a supporter for a round bamboo tray upon 
which the leaves to be fired are spread. In commencing the 
operation, the leaves are thinly spread upon the tray just 
mentioned, which is then put into the cylindrical basket, and 
