: on the Proteolytic Action of Pepsin-hydrochloric Acid. 97 
ence of 3 per cent. of the salt caused a diminution in proteolytic action 
amounting, in the quantity of fibrin digested, to nearly 85 per cent. 
The only apparent explanation of this difference in the results [unless 
due to difference in the amount of ferment] is in the length of time 
the mixtures were warmed at 40° C.; in Wolberg’s 24 hours, in ours 
2 hours. This, if the true reason of the difference, would imply on the 
part of the ferment, ability to gradually overcome the influence of 
small amounts of the substance and thus eventually to digest an 
equal quantity of proteid matter. This, however, would in turn 
imply that the object sought for, viz: the influence of different quan- 
tities or percentages of a substance on the action of the ferment is 
lost sight of. The length of time best adapted to the experiment, is 
naturally that which will bring out most clearly and decisively all 
differences of action. 
Sodium tetraborate (Borax) and Boracic acid. 
Sternberg’s experiments* with both of these substances, have 
shown that, although possessed of no germicide value, they prevent 
the multiplication of bacterial organisms and are thus valuable anti- 
septics. 
Wolberg, in experiments made with artificial gastric juice, found 
that in a 24 hours digestion, 0°5 gram (0°5 per cent.) of borax caused 
a slight acceleration in proteolytic action (0°4 per cent.), while with 
1 per cent. of the salt, retardation occurred to the extent of 23°3 per 
cent., and in the presence of 4:0 per cent. almost complete stopping 
of proteolytic action. Our results, however, fail to show any stimu- 
lating action on the part of the borate, although retardation is very 
pronounced. 
Undigested Fibrin Relative proteo- 
Na2B407+10H20. residue, digested lytic action. 
0 0°3610 gram. 63°90 per cent. 100°0 
0°05 per cent. 0°3852 61°48 96°2 
0°20 04080 59°20 92°6 
0°65 0-7710 22°90 35°8 
1:0 0°9899 101 15 
Doubtless, the retarding action of this salt is due wholly to the 
liberation of boracie acid and the consequent neutralization of the 
hydrochloric acid of the gastric juice. Boracic acid itself, offers no 
obstacle to the proteolytic action of pepsin-hydrochloric acid; on the 
contrary it increases it, but pepsin-boracic acid has little digestive 
* Amer. Jour. Med. Sciences, April, 1883, p. 335. 
Trans. Conn. Acav., Vou. VII. 13 OcT., 1885. 
