THE BILE. 219 



feeding, it is comparatively collapsed and empty. This evacuation of 

 the gall-bladder, excited by the ingestion of food, causes a sudden flow 

 of bile into the duodenum. After that time, its discharge remains pretty 

 constant ; not varying much, in a dog of sixteen and a half kilogrammes' 

 weight, from 256 milligrammes of the biliary salts every fifteen minutes, 

 or a little over one gramme per hour. In a man of ordinary size (65 

 kilogrammes), if the quantity of bile were increased in proportion, this 

 would amount to 8.667 grammes of solid biliary matter per hour dis- 

 charged into the intestine during the greater part of the digestive process. 



Daily Quantity of the Bile. The first experiments of value upon this 

 point were those of Bidder and Schmidt, published in 1852. 1 They were 

 performed upon dogs, cats, sheep, and rabbits, in the following manner : 

 The abdomen was opened, and a ligature placed upon the common 

 biliary duct, so as to prevent the bile finding its way into the intestine. 

 An opening was then made in the fundus of the gall-bladder, by which 

 the bile was discharged externally. The bile, so discharged, was received 

 into previously weighed vessels, and its quantity accurately determined. 

 Each observation usually occupied about two hours, during which period 

 the temporary fluctuations occasionally observable in the quantity of 

 bile discharged were mutually corrected, so far as the entire result was 

 concerned. The animal was then killed, weighed, and carefully ex- 

 amined, in order to make sure that the biliary duct had been securely 

 tied, and that no inflammatory alteration had taken place in the ab- 

 dominal organs. The observations were made at different periods after 

 the last meal, so as to determine the influence exerted by the digestive 

 process upon the rapidity of the secretion. The average quantity of 

 bile for twenty-four hours was then calculated from a comparison of the 

 above results ; and the quantity of its solid ingredients was also ascer- 

 tained in each instance by evaporating a portion of the bile in the water 

 bath, and weighing the dry residue. 



Bidder and Schmidt found in this way that the daily quantity of bile 

 varied considerably in different species of animals. It was much greater 

 in the herbivorous animals used for experiment than in the carnivora. 

 The results obtained by these observers were as follows : 



For every kilogramme of the entire bodily weight of the animal, there 

 is secreted, in twenty-four hours, 



Fresh bile. Dry residue. 



In the cat . . . 14.537 grammes. 0.816 grammes. 

 " dog . . . 19.956 " 0.985 



" sheep . . . 25.372 " 1.340 



" rabbit . . . 136.556 " 2.464 



According to the later researches of Schiff, 2 these estimates are cer- 

 tainly not beyond the truth, since he obtained considerably larger 

 quantities in the dog, by simply establishing an open fistula of the gall- 



Verdauungssaefte und Stoffwechsel. Leipzig, 1852. 



Archiv fur die Gesammte Physiologie. Bonn, 1870, Band iii. p. 598. 



