140 Chittenden and Cummins—Influence of Bile 
ence of 2 per cent. of bile. Wittich* and also Hofmann have noticed 
the occasional diastatic action of bile, Wittich even extracting the 
ferment from human bile by his glycerine method. Gianuzzi and 
Bufalinit have shown that the action varies considerably in bile 
from different animals and individuals, and without any apparent 
dependence upon the nature of the food. Ewaldt{ states that the 
diastatic capacity of bile appears to be slight in all cases, and is not 
found in bile which has stood for some time. We have found, how- 
ever, in bile from several animals considerable diastatic power; thus 
in one sample of fresh sheep’s bile, 25 c.c. (25 per cent.) converted 
24°33 per cent. of starch into $ugar in 30 minutes at 40° C. We have 
likewise found great variation in diastatic power, varying, expressed 
in the percentage of starch converted into sugar under the conditions 
described, from 4 to 24 in the case of herbivorous animals. We 
have also noticed in bile from sheep and oxen the presence of a 
small amount of sugar, or at least a substance capable of reducing 
Fehling’s solution. In one instance the amount was not inconsider- 
able; 25 grams of ox bile yielding, by Allihn’s method, 0:040 gram 
metallic copper, equal to 0°0209 gram dextrose or 0:08 per cent. 
Naunyn, we believe, has already claimed the presence of sugar in 
bile. 
While we know then that bile acids and bile salts by them- 
selves retard very decidedly the amylolytic action of ptyalin, it 
would appear that the retarding influence of the latter may be, in 
part at least, counteracted by other substances naturally present in 
the bile. 
2.—Influence on the Proteolytic Action of Pepsin. 
It has iong been known that bile has a retarding action on pepsin 
digestion, and Maly and Emich have recently shown the percentages 
of bile acids necessary to bring the action of pepsin to a standstill. 
We have, however, in addition, experimented with bile itself, and as 
in the case of the amylolytic ferment, have endeavored to study the 
influence of the bile acids quantitatively. The method employed for 
measuring proteolytic action is one frequently used in this labora- 
tory, and which has invariably given satisfactory results. The only 
feature which calls for description is the preparation of the proteid 
matter to be digested. The material consists of carefully selected 
* Jahresbericht fiir Thierchemie, 1872, p. 243. 
+ Jahresbericht fiir Thierchemie, 1876, p. 197. 
+ Lectures on digestion, Amer. ed., p. 77. 
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