337 
of Edinburgh, Session 1876 - 77 . 
25. Mercuric chloride is a powerful hepatic stimulant. Its 
stimulant effect on the intestinal glands is feeble. 
26. Calomel is a powerful stimulant of the intestinal glands, 
but does not increase the secretion of bile. 
27. Ammonium chloride has no stimulating effect on the liver of 
the dog. 
28. Castor oil stimulates the intestinal glands, hut not the liver. 
29. Gamboge stimulates the intestinal glands, but not the liver. 
The foregoing results, although adding greatly to our know- 
ledge, are in complete harmony with observations on man in every 
case, save those of calomel and ammonium chloride ; but the 
want of harmony is probably more apparent than real, for there is 
no evidence that in man these substances really do excite the 
hepatic cells. They may possibly occasion merely expulsion of 
bile already secreted, or may act on the liver in other ways. The 
general conclusions of the research are as follows 
1. That, as the liver of the dog is affected by medicinal agents 
in the same sense as the human liver, this animal is suitable for 
observations that cannot be made on man. 
2. The attention of medical men is hereby directed to a number 
of valuable cholagogues, such as euonymin, sanguinarin, iridin, 
ipecacuan, sodium phosphate, sodium sulphate, &c., hitherto but 
little or not at all employed as such, owing to the absence of 
positive information regarding their actions. 
3. As regards the whole question of hepatic pharmacology, 
definite is hereby substituted for indefinite knowledge ; for it is not 
only shown what substances really do act as cholagogues, but it is 
proved that they all, excepting calomel and ammonium chloride, 
really do stimulate the liver to secrete more bile. 
4. It is shown that, as such substances as magnesium sulphate, 
gamboge, and castor oil do not increase the secretion of bile, 
although they irritate the mucous membrane of the duodenum and 
the remainder of the intestine, the action of stimulants on the 
secreting apparatus of the liver is probably not reflex from the 
intestinal mucous membrane, but a direct action either upon the 
hepatic cells or upon their nerves. 
5. It is shown that when a purgative substance is not a chola- 
gogue it diminishes the biliary secretion. The importance of a 
knowledge of this fact is indicated. 
