i 
: 
on Amylolytic and Proteolytic Action. 148 
of the ferment; doubtless, due in part to the percentage of free 
hydrochloric acid being diminished by decomposition of the tauro- 
cholate. 
Taurocholic Weight of Fibrin 
acid. undigested residue. digested. 
0 per cent. 0°2059 gram. 79°41 per cent. 
01 06198 38°02 
0°2 0°6426 36°74 
0°5 0°6475 35°25 
Maly and Emich found that 0-2 per cent. taurocholic acid entirely 
stopped the action of pepsin; in our experiments, however, ferment 
action was still manifest even in the presence of 0°5 per cent. of the 
acid. Whether this difference in result is due to difference in the 
acid used, or to difference in method, we cannot say. Glycocholic 
acid we found to be entirely without influence on the action of pepsin, 
as did also Maly and Emich. 
3.—The Proteolytic Action of Trypsin in Neutral, Alkuline and 
Acid Solutions, 
The trypsin solution was prepared according to Kiihne’s method,* 
from dried pancreas freed from fat; the solution after neutralization 
always contained some sodium salicylate, sufficient to prevent putre- 
faction during short digestive periods. According to Kiihne,} tryp- 
sin acts quite energetically, both in neutral and in salicylic acid solu- 
tions, but most energetically when the pancreatic solution contains 
0°3 per cent. sodium carbonate. According to Heidenhain,} the action 
of definite percentages of sodium carbonate varies with the amount of 
ferment. 
We have tried quantitative experiments as a preliminary to study- 
ing the influence of bile, with the following results ;§ the mixtures 
were warmed at 40° C. for 3 hours and 40 minutes, and contained 
2 per cent. of fibrin. 
Reaction of Weight of Fibrin 
the fluid. undigested residue. digested. 
neutral 0°2312 gram. 76.88 per cent. 
0°1 per cent. NasCO; 0°1570 84°30 
02 0°0925 90°75 
0°3 00772 92°28 
0°4 0°0426 95°74. 
0°5 0°1038 89°62 
0'1 pr. ct. salicylic acid 0°5651 43:49 
* Untersuchungen aus der physiolog. Inst, d. Universitat Heidelberg, vol. i, p. 222. 
+ Ibid, p. 223. 
{ Pfliiger’s Archiv, vol. x, p. 576. 
§ The pancreatic juice was prepared from 20 grams dry pancreas, and finally diluted 
to 1000 c.c. 50 ¢. c. were used in each digestion with 1 gram of pure fibrin, 
