88 Chittenden and Allen—Influence of various Salts 
a control. 1 gram of fibrin was added to each of the mixtures, which 
were then placed at 40° C. for 2 hours. Band C digested the same 
amount of fibrin as A, consequently the mercuric chloride could have 
exerted no destructive action whatever on the ferment. 
Wassilieff,* in Hoppe-Seyler’s laboratory, found by comparative 
experiments that mercurous chloride (calomel) has no effect on the 
proteolytic action of pepsin. 
Mereuric bromide, Mercuric iodide and Mercurie cyanide. 
These three salts of mercury were experimented with, only so far 
as to compare the action of small quantities, with the action of like 
quantities of mercuric chloride. In using the bromide and iodide it 
was necessary, on account of their insolubility, to dissolve them with 
the aid of an equal weight of sodium chloride, consequently these 
two salts of mercury were doubtless present in the digestive mix- 
tures, in part at least, as double salts. Marle, however, found that 
the action of mercuric chloride with small quantities of sodium 
chloride was not different from that of mercuric chloride alone, and 
doubtless the same is true of the iodide and bromide of mercury. 
Following are the results we obtained: 
Mercury Undigested Fibrin Relative proteo- 
salt. residue. digested. lytic action. 
0 0°3590 gram. 64°10 per cent. 100°0 
HegBr. 
0-005 per cent. 0°3731 62°69 97°8 
0°025 073980 60°20 95°9 
Hel, 
0-005 03114 68:86 107-4. 
0°025 0°3904 60°96 95:1 
He(CN). 
0°005 i 0°3105 68°95 107°5 
0°025 0°3985 60°15 93°8 
0-100 0°3183 68°17 106°3 
From these it is evident that mercuric bromide is less vigorous in 
its hindering action than mercuric chloride ; the iodide still less so, 
while mercuric cyanide, in similar percentages, appears to cause an 
increase in proteolytic action. The iodide, likewise, in the smallest 
percentage experimented with, causes increased proteolytic action. 
None of these salts then, approach mercuric chloride in the intensity — 
of its hindering action on gastric digestion. 
* Ueber die Wirkung des Calomel auf Gihrungsprozesse und das Leben von Mikro- 
organismen. Zeitschrift f. Physiologische Chemie, vol. vi, 113. 
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