air ts 
Chittenden and Cummins—Influence of Bile. 135 
influence of the bile acids in their free condition on ferment action, 
since in the passage of the ferments through the intestinal canal 
there are times, doubtless, when the reaction of the mass is more or 
less alkaline, especially in the small intestines, for some distance be- 
yond the opening of the bile and pancreatic ducts. In either case it 
is an interesting point to ascertain whether the bile salts have an 
action at all analogous in kind or extent to that of the free acids. 
Many observations* are recorded concerning the duodenal precip- 
itate formed in the duodenum by the action of bile on the acid-re- 
acting chyme. The precipitate itself has generally been supposed 
to consist of a mixture of syntonin, peptone and bile acids, but recent 
experiments of Maly and Emicht with pure bile acids tend to show 
that only the non-peptonised albuminous bodies are precipitated, viz: 
coayulable albumin and syntonin, and these only by taurocholic acid, 
while peptone and “ propeptone” remain in solution. This fact lends 
favor to the view advanced by Hammarsten, that the object of the 
precipitation of albuminous matter on the walls of the intestines 
is to prevent its too rapid passage through the intestinal canal, thus 
giving ample opportunity for the action of the pancreatic juice. 
The addition of taurocholic acid to a solution of peptone, Maly 
and Emich find, is followed by the formation of a distinct opal- 
escence or fine dust-like precipitate, slowly changing to fine droplets. 
This precipitate, however, which is doubtless the same as observed 
by Hammarsten and Briicke on the addition of bile to portions of a 
digestive mixture, does not contain according to Maly and Emich, 
any peptone, but consists of taurocholic acid, possibly in a modified 
form. 
Both of these precipitations, however, would tend to mechanically 
throw down, to a greater or less extent, any ferment present, and 
thus diminish ferment action; but, as Maly points out, the main 
reason for a diminished action, in the case of pepsin, is to be sought 
for, not in a precipitation of the ferment, but in the formation of a 
compound of albumin with the bile acid, not digestible by pep- 
sin-hydrochloric acid. But since this precipitation, as a normal reac- 
tion in the animal body, must take place in the intestinal canal, it is 
equally important to ascertain the extent of its digestibility in pan- 
creatic juice, or, in other words, to ascertain the exact influence of 
bile and its several constituents on the proteolytic action of trypsin 
* See Maly in Hermann’s Handbuch der Physiologie, vol. v, p. 180. 
+ Monatshefte fiir Chemie, vol. iv, p. 89. 
