‘Dr. Oscar ‘Loew: 47 
and the access of air accelerates the blackening 
‘process. 
A case in which tannin is changed by partial 
oxidation for the sake of removing the 
astringent taste is observed in the curing of 
the fruit of certain varieties of persimmon 
(kaki) in Japan. By the curing process, 
which consists in keeping the fruits in alcohol 
vapour or in subjecting them to slow desicca- 
tion in the sun, the tannin is changed, in con- 
tact with an oxidizing enzyme and oxygen, to 
a brown, tasteless substance.' The fruit thus 
acquires an agreeable taste. 
Since a moderately brown colour is also pro- 
duced in white “nibs,” free of cacao red, it 
follows that the brown colouration is not due 
facture by fermentation, and we find that we do not 
know what is the cause of this process. If we rule the 
pure oxidation theory as out of court there then remain 
the enzyme theory and the micro-organism theory. The 
former as propounded by Dr. Mann—that fermentation 
is caused by a soluble ferment or enzyme which exists 
in the cells of the leaf, and which on being set free 
during rolling causes the oxidation of the tannin. The 
latter was advocated about two years ago by Dr. C. L. 
“Bernard, of Java, who claimed that fermentation is 
caused by soluble enzymes which do not exist in the 
cells of the leaf but in those of micro-organisms. Much 
the same uncertainty is attached to practically every 
branch of tea manufacture. It is surprising that a 
Scientific Department was not created many years ago. 
If such had been the case we should probably now be 
‘groping in the dark” to a,much less extent than we 
are.—H. H. S. ; 
1S, Sawamura. Ibid., 5 (1902-3), p. 237. 
