118 Chittenden and Cummins—Influence of various Substances 
The effects of these two salts on the proteolytic action of the fer 
ment are very similar, with the exception that potassium chlorate 
appears to be a little more energetic in action than the nitrate. 
Weiss* has stated that a very small quantity of potassium nitrate 
added to a pancreas infusion, causes slight increase in the proteolytic — 
activity of the ferment. This, however, is not observable in our ex-— 
periment with 0°05 per cent., although retardation is very slight. 
Potassium chloride. 
This salt, unlike sodium chloride, appears to cause retardation of 
proteolytic action, and is without any accelerating influence what- 
ever. The extent of its retardation, however, is not so great as in — 
the case of sodium chloride. Following are the results obtained. 
Undigested Fibrin Relative proteo- 
KCl. residue. digested. lytic action. 
0 0°3662 gram. 63°38 per cent. 100-0 
0°05 per cent. 0°3740 62°60 98°7 
0°5 0°3672 63°27 99°8 
2°0 0°4331 56°69 89°4 
5°0 0°4723 52°77 83°2 
Sodium chloride. 
With this salt many previous experiments have been tried; Heid- 
enhain,+ after noting the accelerating action of sodium carbonate, 
tried the influence of sodium chloride and found that it increased | 
the proteolytic power of the ferment. . Pfeiffer, however, states — 
that he found sodium chloride to exert a retarding influence on the 
proteolytic action of the pancreatic ferment. Pfeiffer[ moreover 
states that he found sodium carbonate to exert its accelerating action 
only when present in 0°5 per cent., not in 0°24 per cent. as found by 
Heidenhain. Recent results§ obtained by us in another connection, 
however, fully substantiate Heidenhain’s statements on this point. 
Lastly, Lindberger|| has found that sodium chloride, which in a neu- 
tral or alkaline solution of trypsin accelerates its proteolytic action, 
causes in an acid solution (0°018 per cent. HCl, presumably as acid- 
proteid) marked retardation of ferment action, without, however, — 
* Loe. cit. 
} Beitrage zur Kenntniss des Pancreas, Pfliiger’s Archiv, vol. x, p. 578, 
t Loe. cit. 
§ Chittenden and Cummins, Amer, Chem. Jour., vol. vii, p. 46-47. Also Trans. 
Conn. Acad., vol. vii. 
|| Jahresbericht fiir Thierchemie, 1883, p. 281. 
