268 The Fermentation of Cacao 
occurring during fermentation may be con- 
sidered as being the brown colouration and 
the reduction of the bitter taste of the nibs. 
I am pleased to find that Loew, in explain- 
ing this change, arrived in the main at the 
same, conclusions that I did in my investiga- 
tions undertaken a year later. There is one 
point in which Loew’s results differ from mine. 
According to him the oxidase is insoluble, 
whilst I have regarded it as soluble. In my 
experiments I used an extract of fresh beans, 
which were crushed under water so as to 
delay oxidation. The filtrate was never clear, 
and it is therefore possible that the substance 
causing the cloudiness contained the oxidase. 
In order to clear up the divergence the follow- 
ing experiment was made. Fifteen beans. 
were broken up in an atmosphere containing 
carbonic acid and then covered with boiled 
water. This was then filtered in a similar 
atmosphere. The filtrate was at first cloudy, 
but soon ran off clear. The clear, reddisl- 
violet solution gave a marked oxidase reaction. 
Brought into contact with oxygen containing 
air it soon turned brown and became clouded, 
owing to precipitation of tannins. This brown 
solution showed a very much weaker reaction 
with oxidase reagents. If a few drops were 
allowed to fall on blotting-paper and a solution 
was added of, say, for instance, tetramethyl- 
paraphenylen-diamin-hydrochloride, the most 
marked blue reaction occurred in the centre, 
