Chittenden and Cummins— Action of the Pancreatic Ferment. 109 
The solution of trypsin was prepared according to Kiihne’s* 
method from dried ox pancreas freed from fat; 40 grams dry pan- 
creas in 500 ¢. ¢. 0°1 per cent. salicylic acid, neutralized and diluted to 
2 litres.t In each digestion experiment, 25 ¢. c. of this neutral trypsin 
solution were used, to which was added 25 c. c. of water containing 
the substance to be experimented with, or in the control 25 ¢. ¢. of 
water alone, making the volume of the digestive mixture in each case 
50 c.c. In testing the proteolytic action of the different solutions, 1 
gram of pure dry, pulverized fibrin, described in the preceding 
article, was added and the mixtures warmed at 40° C. for six hours, 
after which the undigested fibrin was filtered on weighed filters, 
washed thoroughly and dried at 100-110° C. until of constant weight. 
In this work as in the study of the salivary ptyalin and pepsin, it 
has been the effort mainly to ascertain the relative action of small 
quantities of the various salts, rather than the percentages necessary 
to completely stop the action of the ferment, this to our mind being 
much the more important. 
Mercurie chloride. 
With small percentages of this salt, the following results were 
obtained : 
Undigested Fibrin Relative proteo- 
HgCly. residue. digested. lytic action. 
0 0'4495 gram. 55°05 per cent. 100°0 
0:002 per cent. 0°4465 55°35 100°5 
07003 0-44.05 55°95 101°6 
0°005 0°4562 54°38 98°7 
0°025 05076 49°24 89°4 
0-100 0°7753 22°47 40°8 
As seen from the table, 0-1 per cent. mercuric chloride diminishes 
the proteolytic action of the ferment more than one-half. Its action 
in this percentage is more energetic than on pepsin, although the 
smaller quantities are proportionally far less active; in one case 
(0003 per cent.) even causing acceleration. 
Wassilieff { has studied the influence of mercurous chloride on pan- 
creatic digestion and finds that calomel does not affect the action 
of the proteolytic ferment, while it does prevent the formation of 
putrefaction products, viz: indol, phenol, ete. 
* Untersuchungen aus der physiolog. Inst. d. Universitat Heidelberg, vol. i, p. 222. 
+ The solution was kept from putrefaction by the use of a little 20 per cent. 
alcoholic solution of thymol; enough of which remained dissolved in the fluid to pre- 
vent putrefaction also during the six hours digestion at 40° C. 
} Zeitschrift fir physiol. Chemie, vol. vi, p. 112. 
