io8 Vines . — The Proteases of Plants ( V s ). 
on boiling, distinct tryptophane-reaction, and good biuret-reaction. About 50 cc. of 
the H 2 0-extract were put into each of two bottles, to one of which o-i grm. of Witte- 
peptone was added, and two similar bottles of NaCl-extract were prepared ; both the 
bottles to which Witte-peptone had been added gave strong biuret-reaction; some 
HCN was added to all the bottles. After 48 hours’ digestion the reactions were : — 
Tryptophane. 
Boiling. 
Biuret. 
H 2 0-ext. without W.-peptone 
marked 
no ppt. 
indistinct 
ISaCl ,, ,, ,, 
less marked 
slight ppt. 
good 
H 2 0 „ with „ 
strong 
no „ 
distinct 
NaCl „ 
At close of experiment 4 days 
later — 
slight „ 
good. 
H 2 0-ext. without W.-peptone 
marked 
no 
none 
NaCl ,, „ ,, 
>> 
>5 15 
good 
H 2 0 „ with „ 
strong 
>5 55 
faint 
NaCl ,, ,, „ 
>> 
55 55 
good. 
The marked reduction in the intensity of the biuret-reaction in the 
bottle to which Witte-peptone had been added proves that the H 2 0-extract 
was able to peptolyze more proteid than it originally contained. Without 
this experimental addition of proteid the results of autolysis might have 
been attributed to the larger amount of proteid in solution in the NaCl- 
extracts as compared with the H 2 0-extracts ; but it is now made clear that 
the difference in the biuret-reactions of the two extracts is due to the 
difference in the relative amount or activity of the peptolyzing enzyme, and 
not in the relative amounts of proteid that they contain. Whilst NaCl- 
extracts, on the one hand, digest fibrin more actively on account of the 
larger amount of the protease that they contain, H 2 0-extracts, on the 
other, are more active peptolytically. Consequently these results bear upon 
the question that I have raised in several papers, the question as to the 
number and nature of the proteases occurring in plants : to this I return in 
the latter portion of this paper. 
Experiments with other oily seeds . 
I have devoted so much time to the investigation of the Hemp that it 
has not been possible to make more than a few cursory observations on other 
oily seeds, those of the Mustard (S inapis alba), the Hazel (Cory Ins av ell ana), 
the Castor-Oil plant (Ricimis communis ), and the Flax (Linum usitatis- 
simum). 
Sin apis alba. Experiments on autolysis made with aqueous mixtures 
or extracts (io°/ o ) of ungerminated seeds gave negative results, nor did 
they digest fibrin ; but a stronger extract, whether aqueous or of NaCl 2 °/ o 
solution, proved active. 
Experiment i. 15 grms. ground seed were extracted with 100 cc. H 2 0 , and the 
same weight with 100 cc. 2 % NaCl-solution ; the filtrates gave no tryptophane- 
