on the Proteolytic Action of Pepsin-hydrochloric Acid. 87 
Undigested Fibrin Relative 
HgClg. residue. digested. proteolytic action. 
0 0°3759 gram. 62°41 per cent. 100°0 
0-001 per cent. 04140 58°60 93°8 
0-005 0°4210 57°90 92:7 
0 0°1307 86°93 100°0 
0-1 04765 52°35 60°2 
0°5 0:9007 SR 11°4 
10 1:0495 ; 0 0 
M. Marle* has previously experimented with mercuric chloride 
and has likewise found that small quantities of the salt exercise a 
retarding action upon gastric digestion; that as the percentage of 
corrosive sublimate is increased, the retarding action is correspond- 
ingly increased, although this effect is diminished up to a certain point, 
by increasing the strength of the digestive mixture. Marle considers 
that this action of mercuric chloride does not depend upon decompo- 
sition of the ferment nor upon a contraction of the albuminous 
matter, but rather that the salt in an acid solution enters into a 
chemical combination with the proteid matter and the latter is thus 
rendered impervious to the digestive action of the ferment. 
In support of this view we offer the fact that fibrin introduced into 
an acid solution of pepsin in the presence of 1 per cent. of mercuric 
chloride, increases in weight; in the experiment given above to the 
extent of 49:5 milligrams. This would clearly indicate a combina- 
tion of the two. Moreover, that mercuric chloride does not act 
by destroying the ferment we have ample proof, as the following 
experiment shows : 
: A. B. G 
H,0 sol. glycerine pepsin _--- 5c.¢. Sec: biexe: 
UCI. (0:2: per cent.) 2-222 - 20 20 0 
EUG Ul npeyens be Ace Sere Meee ao 0 07025 gram. 07025 gram. 
155 (0), ie a Ra a hs 0 0 20 ¢ ¢: 
25 25 ¢. ©. 25 
Rercent, tieCl, 20es oo ses 0 0-1 01 
These three mixtures were warmed at 40° C. for 24 hours; then to 
A was added 0:025 gram HgCl, dissolved in 25 ¢. c. 0°2 per cent. 
HCl, to B 25 c.c. 0:2 per cent. HCl and to C 25 c.c. 0-4 per cent. 
HCl. The three solutions were now exactly alike; in 6, however, 
the ferment had been exposed to the action of 071 per cent. HgCl, in 
an acid solution for 24 hours, in C’ to the action of the same percent- 
age of the mercury salt in an aqueous solution, while A served as 
* Abstract in Jahresbericht fir Thierchemie, 1875, p. 168. 
