UN THE ACTION OF MERCURY ON THE BILIARY SECRETION. 223 
urged that, although we have proved this regarding dogs, it does not follow 
that on man these drugs will have the same action. It must be admitted 
that some animals are altogether insensible to remedies which produce power- 
ful effects on others, that different doses are often requisite to occasion similar 
results, and that there may be peculiarities so very decided as to render it 
impossible to infer what will be the action of a remedy on one animal from its 
influence upon another. But have we any reason to conclude that in the pre- 
sent instance there exists such difference in the action of mercury as to prevent 
any inference being drawn from the dog regarding man? All the facts with 
which we are acquainted show that it is legitimate to infer that the action of 
mercury ought to be regarded as similar in voth cases. We have demon- 
strated that, as regards its action upon the salivary glands, mouth, intestine, 
appetite, and general nutrition, the influence of mercury is the same. We there- 
fore infer that itis in the highest degree probable that its action on the hepatic 
secretion will also be the same. The only difference that there seems to be be- 
tween the dog and man, as regards the action of mercury, consists in the fact 
that in the dog larger doses are generally required to produce the same effects 
as those observed inman. But even here it may be argued that more marked 
results are required to satisfy the observer, and hence the greater dose neces- 
sary. These circumstances, therefore, cannot be held as affecting the conclu- 
sion at which we have arrived. 
We have not deemed it worth our while to experiment upon any other 
animal, for we are unable to see how such experiments could materially 
strengthen our position. Even though we had shown that mercury when 
given to a rabbit, cat, pig, donkey, or horse diminishes the biliary secretion, 
it might still be said that this does not apply to man. But there are several 
special reasonswhich render experiments on these animals either impracticable 
or less reliable than those on the dog. Bidder and Schmidt failed to establish 
biliary fistulee in cats, we therefore thought it not worth our while to spend 
money and time in making the attempt. Horses and donkeys are too un- 
wieldy for the purpose and have no gall-bladders, a peculiarity which would 
in all probability render it impossible to establish biliary fistulein them. In 
pigs. the hepatic secretion differs from that of man, inasmuch as it contains 
hyocholic acid, and according to Strecker no sulphur. It might, therefore, not 
unfairly be objected to any inferences from experiments on pigs that, inasmuch 
as the porcine differs from the human hepatic secretion, it could not be held as 
altogether probable that mercury would influence both in the same way. 
‘Everything seems to show that the animals used by the Committee are those 
best suited for the observations they have made. In addition to the thera- 
peutical facts previously mentioned, which after all are the most important, 
there are these, that the qualitative composition of canine is the same as that 
of human bile, and that the dog, like man, can be fed on a flesh, vegetable, 
or mixed diet. In this respect they are stiperior to most others, even to the 
Quadrumana, which though in conformation most resembling man are vege- 
table feeders. So far, therefore, as direct experiment and exact observations 
‘are capable of determining the influence of mercury upon the biliary secretion, 
‘the Committee have no doubt that the dog is superior to the animals above 
“mentioned. 
But it may be supposed that mercurials possess some specific power of ex- 
citing the biliary secretion by acting on the orifice of the common bile-duct, 
and so stimulating the secretion through the nerves which connect it with the 
liver, just as pyrethrum or vinegar stimulates the salivary glands when they aie 
applied to the orifices of the salivary ducts. It might also be objected that, 
