221 
Vines .— The Proteases of Plants ( VII). 
Witte-peptone: a solution, in fact, containing only peptase. With this 
object in view, the following experiment was made :— 
Experiment 7. 1 grm. of Taka-diastase was mixed with 100 c.c. of 50 % alcohol 
and immediately filtered: the residue on the filter was then treated with 60 c.c. 50% 
alcohol, and when that had filtered off, with 50 c.c. more of the same alcohol. The 
residue w r as then treated with 80 c.c. distilled water. 40 c.c. of the watery filtrate were 
put into each of 2 bottles: to the one was added 0-2 grm. fibrin, to the other 0*2 grm. 
Witte-peptone : the liquid containing Witte-peptone gave no tryptophane-reaction. 
After 24 hours in the incubator, the fibrin had disappeared in the one bottle, and 
the contents of the other gave no tryptophane-reaction ; 24 hours later, the contents 
of the latter bottle gave a trace of tryptophane-reaction, which did not increase during 
48 hours. 
I succeeded, therefore, in the attempt to remove the ereptase, and 
to obtain from the residue a solution which contained only peptase. This 
result, together with that of Experiment 6, proves that Taka-diastase con¬ 
tains two distinct proteases, a peptase and an ereptase. 
Summary. 
The foregoing experiments lead to the following conclusions : — 
1. Malt-diastase (whether maltine or absolute) and Taka-diastase both 
contain proteases which digest fibrin and produce tryptophane from 
albumoses and peptones whether produced by digestion or added as Witte- 
peptone. 
2. It is possible to extract from both of these substances, by means 
of alcohol of various strengths, a protease which digests Witte-peptone 
but has no action on fibrin: this protease is therefore ereptase. 
3. On washing out all the ereptase from Taka-diastase, the residue 
yields, on extraction with water, a solution which digests fibrin but has 
no action on Witte-peptone : this solution therefore contains peptase. Such 
a solution has not yet been obtained from Malt-diastase. 
4. Since both Taka-diastase and Malt-diastase digest fibrin more 
rapidly in acid than in alkaline medium ; and since the enzymes are 
excreted, in the case of Taka-diastase by the Aspergillus Oryzae into 
the organic matter upon which it is cultivated, in the case of Malt by the 
Barley-embryo into the endosperm ; it would seem natural to refer the 
peptase to the group of proteases which, in my last paper on this sub¬ 
ject (2 ; 1909), I termed Ectopeptase. 
' But in the course of some quite recent and still incomplete experiments 
I have found that solutions of the peptase of Taka-diastase, freed from 
ereptase (and doubtless from other substances as well) by the alcohol 
method (see Experiment 7, above), digest fibrin more actively when the 
