256 EXCRETION. 



weighing one hundred and forty pounds would be about two 

 and a half pounds. 1 



Variations in the Flow of the Bile. We have already 

 considered, in another section, the variations in the flow of 

 bile, and their relation to the process of intestinal digestion. 8 

 It is sufficient in this connection to repeat that the discharge 

 from a biliary fistula in a dog increases immediately after 

 eating ; that it is at its maximum from the second to the 

 eighth hour, during which time it does not vary to any great 

 extent ; after the eighth hour it begins to diminish, and from 

 the twelfth hour to the time of feeding, it is at its minimum. 

 Prof. Dalton made observations on the flow of bile from a 

 fistula into the duodenum, which would represent the physi- 

 ological discharge of bile into the intestine more nearly 

 than observations with a biliary fistula. He found that 

 by far the largest quantity passes into the intestines im- 

 mediately after feeding and within the first hour. 3 These 

 results agree in all essential particulars with previous obser- 

 vations on this subject which have been very numerous 

 and they show that while the bile is discharged much more 

 abundantly during intestinal digestion than during the in- 

 tervals of digestion, its production and discharge are con- 

 stant. This, we shall see in the next chapter, is a strong 

 argument in favor of the view that the liver has an excre- 

 mentitious function. 



The bile is stored up in the gall-bladder to a consider- 

 able extent during the intervals of digestion. If an animal 

 be killed at this time, the gall-bladder is always distended ; 



1 This is the estimate adopted by Dalton (Treatise on Human Physiology, 

 Philadelphia, 1867, p. 172). In our own experiments, made on a dog with a 

 biliary fistula, the object was not so much to ascertain the entire quantity of 

 bile in the twenty-four hours as to note the variations in its flow. The estimate 

 was made in a dog that had become somewhat enfeebled, and is undoubtedly 

 too low. (See vol. ii., Digestion, p. 375.) 



2 See vol. ii., Digestion, p. 375. 



3 DALTON, op. cit., p. 176. 



