PHYSIOLOGICAL ACTIONS OF DRUGS ON THE SECRETION OF BILE. 137 
and that a similar effect, though to a less extent, was produced by colocynth, 
jalap, aloes, rhubarb and senna, and sulphate of magnesia—the potency of 
_ these agents as stimulants of the liver being in the order mentioned. He found, 
moreover, that castor oil had little effect, and that calomel, while it seldom 
recalled the biliary secretion after it had ceased, nevertheless somewhat aug- 
| mented it when it was taking place slowly. 
| Rourie’s statement with regard to calomel does not much differ from that 
_ made by Hucues BENNETT’s committee, but nevertheless he did find that certain 
| purgative agents, when given to fasting animals with temporary biliary fistule, 
_ increased the biliary secretion, while the committee found that in non-fasting 
animals with permanent fistule, purgative action, induced by podophyllin, 
calomel, &c., diminished the amount of bile secreted in the twenty-four hours. 
| It appeared to me that this important subject could not be allowed to 
remain in a position so unsatisfactory. I therefore entered on the following 
| research, but ere I had proceeded very far I found its labours so excessive, that 
| I was glad to avail myself of the very valuable assistance of my pupils, 
| Monsieur W. Vienat, and latterly of Dr Wii1am Dopps, in performing the 
| experiments. 
METHOD OF EXPERIMENT. 
All the experiments recorded in the following pages were performed on 
| dogs. The dog was selected—1. Because the size of its common bile duct 
| renders it possible to introduce a cannula with an orifice sufficiently large to 
| prevent its being blocked up by particles of inspissated mucus from the gall- 
| bladder. 2. For the reason that its digestion resembles that of man, inasmuch 
| as its stomach becomes empty when the process is completed. It is very 
| different in the case of a rabbit, whose stomach is never empty. 3. As Rénric 
| had performed his experiments on dogs, it was necessary that we should com- 
| pare our results with his. The selection of the dog has proved fortunate, for 
| the results of our experiments are in complete harmony with every perfectly 
_ ascertained fact regarding the actions of medicinal agents on the human liver, 
and prove that the liver of this animal is affected in the same sense—although 
it may not be to the same degree—by substances that act on the human liver. 
| All the experiments having been performed on animals of the same species 
| placed as nearly as possible under similar conditions, the results are fairly 
| comparable ; although it must be borne in mind that just as no two members 
| of the human species can even in their normal condition be regarded as equally 
susceptible to the influence of any medicinal agent, neither can any two mem- 
bers of the canine species be held to possess identical susceptibilities. All the 
animals had a full meal of lean meat at three or four o’clock in the afternoon, 
VOL, XXIX. PART I. 2N 
