572 Vines . — The Proteolytic Enzyme of Nepenthes. 
the add in minute quantity arrests the action of, and even 
kills, Yeasts and Bacteria, it has little or no effect upon 
the action of enzymes unless present in large proportion. I 
accordingly arranged the following experiment : — 
Oct. 27, 1897. 5 c.cm. of pitcher-liquid were placed in each of two 
tubes A and B. To A were added 5 c.cm. of 2°/ o HCN solution, 
and one drop of strong HC 1 : to B were added 5 c.cm. of a o*5°/ 0 
solution of HC 1 , and to each 0-05 grm. of fibrin. The tubes were 
placed in the incubator (37 0 C.) at n a.m. : at 12.30 p.m. the fibrin 
had completely disappeared in both tubes. 
This experiment appears to me to absolutely exclude 
the hypothesis of bacterial action, and to establish beyond 
doubt the fact that the pitcher-liquid of Nepenthes contains 
a proteolytic enzyme. 
However, I felt it advisable to secure my position by 
experiments on the other side ; by experiments of such 
a kind that whilst the conditions were favourable to bacterial 
action, they should be fatal to the action of an enzyme, and 
that, under these conditions, no solution of fibrin should take 
place. It is known that whilst alkalies are destructive of 
enzymes, they are not nearly so fatal to organized ferments. 
My experiments were then directed to determine the effect of 
treatment with alkalies upon the digestive activity of the 
pitcher-liquid. The general plan of the experiments was 
to treat some of the liquid for a time, at a temperature 
of 35°-4o°C., with alkalies in various strengths ; and then, 
after neutralizing the liquid, to test its digestive activity in the 
usual way. Without going into further detail, I may briefly 
state that the alkalies which I used were sodium carbonate 
(Na 2 Co 3 ) and sodium hydrate (Na HO), and that I find the 
activity of the liquid to be destroyed by treatment with 
T/ o Na HO for one hour, and by treatment with 5°/ 0 Na 2 CO s 
for three hours. I hope to determine these limits more 
definitely in the future. I may incidentally mention that 
the addition of these alkalies produced, in every case, a pre- 
cipitate in the pitcher-liquid ; but I have not yet been able 
to ascertain the nature of this precipitate. 
