140 PROFESSOR RUTHERFORD ON THE 
impossible to analyse the bile in all cases. We therefore discontinued the 
analyses, after observing that even when a hepatic stimulant renders the bile 
more watery, the increased velocity of secretion always more than compensates 
the diminution of the solids, and thus compels the liver to produce in a given 
time a larger amount of the biliary constituents proper. 
We were also at the pains to make in most cases post-mortem examinations of 
the small and sometimes of the large intestines and stomach, in order to com- 
pare the effect of the drug on the liver with its effect on the intestine. The 
results are valuable, because—1. They furnish for the first time a systematic 
account of the effects of well-known and also of many new drugs upon the intes- 
tinal mucous membrane ; 2. By separating the secretion of the liver from that 
of the intestinal glands, a more exact knowledge of the effects of substances on 
the latter is obtained, and a very important generalisation regarding the effect 
on the secretion of the bile, produced by stimulating the intestinal glands, has 
been arrived at, as will be shown in the sequel. It ought to be observed that 
some of the substances might perhaps stimulate the pancreas, and as the 
pancreatic duct was never tied, the fluid in the intestinal canal may have been 
a mixture of intestinal and pancreatic juices. But as the liver was the primary 
object of our investigations, it would have been altogether unjustifiable to have 
set up more irritation at the duodenum, by cutting down on the pancreatic duct 
and placing a cannula in it—always a difficult thing to do in the dog, and apt 
to involve a good deal of hemorrhage. Although by such a procedure, definite 
knowledge might have been arrived at with regard to what substances affect the 
pancreas, yet our results as regards the liver—a gland of greater importance—in 
the economy, might have been vitiated. Probably in most cases the fluid found 
in the intestine was chiefly intestinal juice, but for the reason mentioned no 
conclusive statement is permissible with regard to this point. 
The small doses of curara given to the animals were injected into the jugular 
vein, in order that their effect might be speedy ; but nearly all the drugs given 
for the purpose of affecting the liver or intestine were injected into the 
duodenum, because the animals being curarised could not swallow, and the 
penetration of the duodenal wall by the sharp nozzle of a small syringe was a 
much simpler operation than the introduction of a tube down the cesophagus into 
the stomach. Moreover, the stomach in a dog that has fasted for many hours 
usually contains a large quantity of mucus that must have retarded the 
absorption of the substance if given by the mouth. To avoid this delay was a 
matter of great importance, both on the animal’s account, and also because of 
the impossibility of continuing the experiment for more than a few hours. 
Moreover, it has been alleged that the action of a cholagogue may be due to 
a reflex excitement of the liver proceeding from the duodenal mucous membrane; 
therefore by always injecting the substances into the duodenum we ensured its 
