182 FUNCTIONS OF NUTRITION. 



for some time without food the gall-bladder is usually distended with 

 bile, while in those killed immediately or soon after feeding it is com- 

 paratively empty. At the commencement of digestion it is excited to 

 contraction, causing a sudden flow of bile into the duodenum. After 

 that time the discharge remains nearly 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. 



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

 point were those of Bidder and Schmidt,* in 1852. They were per- 

 formed on dogs, cats, sheep, and rabbits, in the following manner : A 

 ligature was first placed on the common biliary duct, an opening then 

 made in the fundus of the gall-bladder, and the bile, discharged through 

 this opening, received in previou&ly weighed vessels, and its quantity 

 determined. The animal was then killed, weighed, and carefully exam- 

 ined, to make sure that the biliary duct had been securely tied, and that 

 no inflammatory alteration had taken place. The observations, which 

 were made at different periods after feeding, occupied in each animal 

 about two hours. The average quantity for twenty-four hours was 

 then calculated from a comparison of the above results ; the amount of 

 solid ingredients being ascertained in each instance by evaporating a 

 portion of the bile and weighing the dry residue. 



It was found that the daily quantity varied considerably in different 

 animals, being much greater in the herbivora than in the carnivora. 

 The results obtained were as follows : 



DAILY QUANTITY PER KILOGRAMME OF BODILY WEIGHT. 



Fresh bile. Dry residue. 



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

 " Jdog . . . 19.956 " 0.985 



" sheep . . . 25.372 " 1.340 " 



" rabbit . . . 136.556 " 2.464 " 



According to the later researches of Schiff,f these estimates are not 

 beyond the truth, since he obtained considerably larger quantities in 

 the dog, by a fistula of the gall-bladder, without tying the common 

 biliary duct. While the average quantity obtained in this animal by 

 Bidder and Schmidt was 0.832 gramme of fresh bile per hour for 

 every kilogramme of bodily weight, in the experiments of Schiff it 

 was 1.3 to 3.2 grammes per kilogramme per hour. 



Since in man the processes of digestion and nutrition resemble those 

 of the carnivora, rather than those of the herbivora, it is the former 

 which should be selected as a term of comparison for estimating the 

 daily quantity of bile. If we apply accordingly to the human subject 

 the results obtained by Bidder and Schmidt from the cat and dog, the 

 quantity of bile, for a man weighing 65 kilogrammes, would be a little 



* Verdauungssaefte und Stoffwechsel. Leipzig, 1852. 



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



