220 Vines. — The Proteases of Plants ( VII ). 
distinct tryptophane-reaction ; the reaction given by Nos. 2 and 3 had increased in 
intensity. 
In the meantime the residue of the diastase on the filter had been again 
extracted with 80 c.c. of 25% alcohol. 20 c.c. of this filtrate were diluted with an 
equal volume of water and were put into a bottle with 0*2 grm. Witte-peptone; the 
remaining 60 c.c. were evaporated (at 37 0 C.) to 40 c.c., and then water was added to 
80 c.c., half of it being put into each of 2 bottles, to one of which (No. 1) 01 grm. 
fibrin was added, to the other (No. 2) 0-2 grm. of Witte-peptone. 
After 24 hours in the incubator, the diluted alcoholic extract gave a distinct 
tryptophane-reaction ; the fibrin in No. 1 was mostly digested; and the contents of 
No. 2 gave a marked tryptophane-reaction. 24 hours later, the tryptophane-reaction 
of the diluted alcoholic extract was still distinct; the fibrin had entirely disappeared 
in No. 1, and the liquid gave faint tryptophane-reaction; No. 2 gave a distinct 
reaction. 
The residue on the filter, which had been already twice extracted with alcohol, 
was further extracted with 80 c.c. of water : it did not entirely dissolve. 40 c.c. of the 
watery extract were put into each of 2 bottles : to No. 1 was added o-i grm. fibrin; 
to No. 2, 0-2 grm. Witte-peptone. After 24 hours in the incubator, the fibrin in 
No. 1 had almost disappeared; the contents of No. 2 gave a distinct tryptophane- 
reaction. 24 hours later, the fibrin had completely disappeared in No. 1, and the 
liquid gave a faint tryptophane-reaction; the tryptophane-reaction of No. 2 had 
become rather stronger. 
This experiment shows that it is possible, by means of rapid extraction 
with 50 % alcohol, to obtain a liquid which has well-marked peptolytic 
action but digests fibrin very slowly: that it is possible, in fact, to obtain 
a solution containing ereptase almost alone. This result was confirmed by 
other experiments in which the conditions were somewhat different. In 
one case the diastase was treated with 50 % alcohol for 48 hours before 
filtration : the resulting liquid, prepared by evaporation as in the experi¬ 
ment just described, digested Witte-peptone, as shown by a faint trypto¬ 
phane-reaction in 24 hours which increased daily in intensity at natural 
acidity, whereas it failed to digest fibrin at all, even though the experiment 
was prolonged for six days. A similar result was obtained when stronger 
alcohol (63 %) was used for extraction. In both these cases the action upon 
Witte-peptone was much retarded, in consequence of the treatment of the 
substance with alcohol. 
Since it was thus possible to prepare an alcoholic extract of ereptase, 
and since, as the last-mentioned experiment shows, the residue of Taka- 
diastase (unlike Malt-diastase) yielded extracts, made -either with more 
dilute alcohol or with water, which rapidly digested fibrin and had but 
little action upon Witte-peptone, there was ground for the assumption that 
the whole of the ereptase might be extracted from a small quantity of 
Taka-diastase, leaving behind a residue which, on extraction with water, 
would yield a solution which would digest fibrin but would not act upon 
