216 THE BILE. 



a short distance beyond E to F. It is, therefore, always limited on the 

 right by the line F, but extends farther toward E and D, according to 

 the degree of concentration of the liquid. Its edsres are not very well 

 defined, but are more distinct when the band is narrow than when it is 

 wide. Beyond the band, the refrangible portion of the spectrum is 

 quite dim. 



Mode of Secretion of the Bile. It is a matter of importance, in 

 regard to the bile, as well as the other intestinal fluids, to ascertain 

 whether it be a constant secretion, like the urine and perspiration, or 

 whether it be intermittent, like the gastric juice, and discharged only 

 during the digestive process. Bidder and Schmidt have investigated 

 this point in the following manner : They operated by tying the common 

 bile-duct, and then opening the fundus of the gall-bladder, so as to pro- 

 duce a biliary fistula, by which the whole of the bile was drawn off. 

 By doing this operation, and collecting and weighing the fluid discharged 

 at different periods, they came to the conclusion that the flow of bile 

 begins to increase within two and a half hours after the introduction of 

 food into the stomach, but that it does not reach its maximum of activity 

 till the end of twelve or fifteen hours. Other observers, however, have 

 obtained different results. Arnold, 1 for example, found the quantity to 

 be largest soon after meals, decreasing again after the fourth hour. 

 Kolliker and Miiller, 3 again found it largest between the sixth and 

 eighth hours. It appears, accordingly, that the bile is not an intermittent 

 but a constant secretion ; and that the quantity produced varies with 

 the condition of the digestive process, being, according to the majority 

 of observers, most abundant some time after the digestion and absorp- 

 tion of food have commenced in the intestinal canal. 



Discharge of Bile into the Intestinal Canal. As, in those animals 

 which have been the subject of experiment, the liver is provided with a 

 gall-bladder, in which the secretion may be partially accumulated after 

 its production, and from which it may find its way at regular or irregular 

 intervals into the alimentary canal, it becomes important to ascertain 

 by other means at what time and in what quantity it is really discharged 

 into the intestine. In order to determine this point, we have performed 

 the following series of experiments on dogs. The animals were kept 

 confined, and killed at various periods after feeding, sometimes by the 

 inoculation of woorara, sometimes by hydroc} r anic acid, but most fre- 

 quently by section of the medulla oblongata. The contents of the 

 intestine were then collected and examined. In all instances, the bile 

 was also taken from the gall-bladder and treated in the same way, for 

 purposes of comparison. The intestinal contents always presented some 

 peculiarities of appearance when treated with alcohol and ether, owing 

 probably to the presence of other substances than the bile ; but they 

 always gave evidence of the presence of biliary matters as well. The 



1 Cited in the American Journal of the Medical Sciences, April, 1856. 

 8 Ibid., April, 1857. 



