1 6 Vines . — Tryptophane in Proteolysis. 
Neutral liquid', tap- water. 
2 bottles each contained 50 cc. of water : to the one (a) was added’ 
1 grm. of fibrin, to the other (b) 1 grm. of Witte-peptone. 
(a) putrescent odour on 3rd day, distinct tryptophane-reaction 
on the 8th day. 
( 5 ) putrescent odour and marked tryptophane-reaction on the 
2nd day. 
Whilst it is probable that the above results may not be of 
general application, since other proteids and other organisms 
might behave differently, yet they serve to illustrate the 
relation of putrefaction to the other experiments that I was 
carrying on under generally similar conditions. In the first 
place, the antiseptic influence of acid, even of such a weak 
acid as the citric, is clearly demonstrated. It is further shown 
that the putrefactive enzyme works actively, and about 
equally, in neutral and in alkaline liquids, and that it decom- 
poses Witte-peptone with much greater facility than it does 
fibrin. From the experiments with fibrin in neutral and 
alkaline liquids, it would appear that putrescence, as indicated 
by the odour, and the formation of tryptophane are not 
necessarily simultaneous, and that the former may precede 
the latter. It might have been anticipated from the constitu- 
tion of tryptophane, as determined by Hopkins and Cole ( 2 ), 
that the indol and skatol, to which the putrid odour is due, 
would be derivatives of tryptophane, and would only become 
perceptible when the presence of tryptophane could be detected. 
As this was not the case, it is probable that a portion only 
of the indol and skatol formed in putrefaction passes through 
the tryptophane stage. 
In one of the neutral putrefactive digestions of Witte- 
peptone, a chemical fact presented itself that seems to be 
worth special mention. After 48 hours, when it gave a 
strong tryptophane-reaction, the liquid had a marked greenish- 
blue colouration, turning bright yellow on adding a drop of 
acetic acid. The colouration was no doubt due to the forma- 
tion of some indol-derivative. 
