180 Vines. — The Proteases of Plants (///). 
ascertained that NaCl-extracts digest fibrin more actively than watery 
extracts. 
200 grms. of green Malt (n days’ germination) were ground to pulp in the 
machine, and were extracted for 3 hours with 500 cc. of 2 % NaCl-solution, and then 
left on the filter in a cold room for several hours. The filtered liquid was distinctly 
acid, and gave a distinct tryptophane-reaction. To 200 cc. of the liquid 4 grms. of 
Witte-peptone were added, as also toluol to about 1 %. 40 cc. of the extract were 
placed in each of 6 bottles: bottle No. 1 contained extract with toluol only; bottles 
Nos. 2-6, extract with Witte-peptone and toluol ; into each bottle was put 0*3 grm. 
fibrin. No further additions were made to Nos. 1 and 2 : to No. 3, Na 2 C 0 3 was 
added to 1 % (alkaline reaction); to No. 4, Na 2 C 0 3 to 2 % ; to No. 5 , HC 1 to o-i % ; 
to No. 6, HC 1 to o-2 %. 
After 24 hours in the incubator at 45°C., a temperature selected in accordance 
with Weis’s observations, the results were : — • 
1. 
2. 
3 * 
4 - 
5 - 
6. 
fibrin <j 
\ nearly ) 
1 2:one I 
unaltered 
unaltered 
unaltered -j 
\ nearly ) 
1 gone j 
unaltered 
tryptophane marked 
and after 48 hours :— 
very strong 
marked 
marked 
v. 0 J 
strong 
very strong 
fibrin 
gone 
gone 
unaltered 
unaltered 
gone 
unaltered 
tryptophane 
marked 
— 
very strong 
very strong 
— 
— 
Conclusion', fibrin- digestion inhibited by alkalinity, and by 0*2 % HC 1 : peptolysis 
active within the same range of reaction, though it must be remembered that the 
extract gave a distinct tryptophane-reaction to begin with. 
I observed that the reaction of the Na 2 C 0 3 2°/ o bottle in this ex- 
periment changed from alkaline to acid, as commonly occurs in vegetable 
extracts, and consequently makes it difficult to neutralize them or to make 
them alkaline permanently. In order, therefore, to confirm and extend 
the result as to the effect of alkalinity upon the peptolytic activity of 
Malt-extract, I made this further experiment, using a weaker extract and 
larger percentages of Na 2 C 0 3 . 
50 grms. of Malt ground to pulp were extracted with 250 cc. of 2 % NaCl- 
solution, and filtered, the whole process occupying about 6 hours : the acid filtrate 
gave a distinct tryptophane-reaction: to the 160 cc. of filtrate obtained, 3 grms. of 
Witte-peptone were added, and HCN to 0-2 % : 40 cc. were put into each of 
4 bottles, as follows: — No. 1, left at natural acidity; to No. 2, Na 2 C 0 3 to 2 % was 
added ; to No. 3, Na 2 C 0 3 to 3 % ; to No. 4, Na 2 C 0 3 to 4 % ; the contents of all the 
bottles (except No. 1) were more or less strongly alkaline. After 24 hours’ digestion 
at 40° C. the reactions of Nos. 2, 3, and 4 were still alkaline : the tryptophane-reactions 
were : — 
1. 
2. 
3 - 
4. 
strong 
distinct 
distinct 
marked 
