PHYSIOLOGICAL ACTIONS OF DRUGS ON THE SECRETION OF BILE. 143 
these irregularities in the curve were due, not to variation in secretion, but to 
irregularity of outflow, owing to a variation in the facility with which the bile 
could enter the cannula. It was in time ascertained, however, that an 
irregular curve generally ensued when there was much difficulty in inserting 
the cannula into the duct, and the latter had to be a good deal pulled about ; 
in consequence of which the liver probably suffered somewhat from nervous 
irritation. 
Composition of Bile in a Fasting Dog. 
Analyses were made of the bile secreted by the third dog during the first, 
fourth, and last hours of the experiment. 
The following are the results :-— 
TaBie I.—Composition of Bile secreted by a Dog paralysed by Curara after 
Jasting nineteen hours. 
Bile secreted during 
Experiment 3. : = 
First Hour. Fourth Hour. Last Hour. 
Water, ; : 5 ; 89°53 89°58 89:55 
Bile-acids, pigments, cholesterin, fats, 8°73 8°68 8°71 
Mucus, ' } : 0-71 0:72 0°72 
Ash, 1°08 1:02 1:02 
Total, 100-00 100-00 100:00 
It therefore appears that in the progress of the experiment the composition 
of the bile remained almost precisely the same. It should be mentioned that 
in taking the bile secreted near the beginning of such experiments for analysis, 
we were always careful to eliminate that which had been expressed from the 
gall-bladder into the cannula. 
Secretion of Bile per Kilogramme of Body-weight in a Fasting Dog. 
The absolute quantity of bile secreted by different individuals varies with the 
size of the animal; therefore, in order to ascertain the amount of work that is 
really done by the liver in any case, it is necessary to know the quantity of 
bile secreted per kilogramme of body-weight in a unit of time. In all these 
experiments, therefore, the animals were weighed, so that the secretion of bile 
per kilogramme of body-weight might be determined. 
