io6 
Vines . — The Proteases of Plants (V). 
within 48 hours; in No. 2 within 120 hours; in No. 1 digestion was not complete 
in 120 hours. 
It is clear that the presence of the added NaCl in No. 2 promoted 
digestive activity, the salt apparently playing the part of an ‘activator’. 
But since digestion was still more rapid in the NaCl-extract, it may be 
concluded that a considerable proportion of the greater activity of NaCl- 
extracts of seeds, as compared with H 2 0 -extracts. is to be attributed to the 
presence of a larger proportion of fibrin-digesting protease in the former 
than in the latter, enough to justify the inference that the fibrin-digesting 
protease is more soluble in NaCl-solutions than in distilled water. 
The four experiments described suffice to prove that the ungerminated 
seed of the Hemp contains proteases which are capable (1) of digesting 
fibrin, and (2) of digesting the reserve-proteids of the seed (autolysis), as 
shown by the diminution of the precipitate on boiling, and by the develop- 
ment of the tryptophane- reaction. As might be expected, it was found in 
many experiments that Witte-peptone, when added to the liquids, was 
readily peptolyzed, as indicated by a more or less strong tryptophane- 
reaction. It should be mentioned that the extracts sometimes gave 
a tryptophane-reaction to begin with ; a io°/ o H 2 0 -extract gave at most 
a faint reaction, whereas the reaction of 2o°/ o H 2 0 -extract or of a io°/ o 
NaCl-extract was distinct. 
I did not devote much attention to the investigation of the effect of 
increasing the acid reaction by the addition of acid, or of diminishing the 
acidity, or of an alkaline reaction, by adding alkali, a matter that I have 
laid stress upon in previous papers. One such experiment is, perhaps, 
worth recording. 
Experiment 5. 50 grms. of crushed seed were extracted with 350 cc. distilled 
water: about 250 cc. of filtrate were obtained; this liquid gave a dense precipitate 
on boiling, faint tryptophane-reaction, and distinct biuret-reaction. Six bottles, each 
containing 40 cc. were prepared as follows: — No. 1, extract alone; No. 2, added 
Na 2 C 0 3 to 1-25%; No. 3, added HC 1 to 0-05%; Nos. 4, 5, and 6 were exactly as 
Nos. 1, 2, and 3, except that 0-2 grm. of fibrin was added to each ; HCN was added 
to all to o-i%; Nos. 2 and 5 were distinctly alkaline. After 24 hours’ digestion, the 
tryptophane-reactions were, Nos. 1 and 4, marked ; Nos. 2 and 5, faint; Nos. 3 and 6, 
strong ; the fibrin in No. 4 was visibly attacked, in No 5 it was swollen and gelatinous, 
in No. 6 it was quite broken up. 
After 48 hours’ digestion, the fibrin had almost disappeared in No. 6, and was 
broken up in Nos. 4 and 5. The reactions of Nos. 1, 2, and 3 was as follows : — 
Tryptophane. 
No. 1, marked 
„ 2, very faint 
„ 3, marked 
Boiling . 
Biuret. 
slight ppt. 
scarcely any 
scarcely perceptible 
distinct 
none. 
