PHYSIOLOGICAL ACTIONS OF DRUGS ON THE SECRETION OF BILE. 145 
seeing that we have found that whenever a substance increases the biliary 
secretion, it augments the excretion of bile-solids by the liver, even although 
the bile be rendered more watery, we have thought that a statement of the 
amount of fluid bile secreted per kilogramme of body-weight will be sufficiently 
refined for the purpcse of this research. Because the question we set ourselves 
to answer was principally this, What substances have the power of exciting the 
secreting apparatus of the liver ?—a question which cannot be answered by the 
ordinary observations on man, for in his case it is impossible to determine whether 
an increased amount of biliary matter in the dejections be due—(1) To contrac- 
tion of the gall bladder and larger-bile ducts; (2) To the relief of some possible 
spasm of the larger bile ducts; or (8) To an increased secretion by the liver. 
A second question before us was the relative powers as hepatic stimulants 
of the various substances employed. Our answer to this can only be approxi- 
mative, for it would require a considerable number of experiments with any one 
substance to ascertain the most effective dose in the dog. This would entail 
an amount of suffering and of labour that seems altogether unwarranted by the 
result to be attained. We therefore believe that we do enough if we give a 
definite answer to the first of our questions, and an apprcximative answer to 
the second. The latter will be fairly well given by determining the amount of 
bile secreted per kilogramme of body-weight per hour. 
ACTION OF CROTON OIL. 
Rouric has placed croton oil at the head of his list of hepatic stimulants, 
with the statement that in doses from _ 
eighteen drops to a “teaspoonful” it ~ 
has an exciting effect on the biliary 
secretion even under the most un- : 
favourable circumstances (Op. vi. p. 
250)... This substance was therefore 
made the subject of our earliest ex- 
periments. 
Experiment 4. Dog weighing 7°3 
kilogrammes.—Considering the small 
size of this dog, the secretion of bile 
was unusually great. This probably 
resulted from digestion being incom- 
plete; for, although the animal was 
fed seventeen hours before the ex. Me f Seton of fie when dermis se 
periment, at death a quantity of 
elastic tissue, and a greyish fluid resembling chyme, were found in the stomach. 
VOL. XXIX. PART I, 2p 
