EXCRETORY FUXCTIOX OF THE LIVEB. 291 



with much less difficulty than that it is formed in the nervous 

 system. In fact, its presence in the bile, and the necessity 

 of its constant removal from the blood, consequent on its 

 constant formation and absorption by this fluid, are almost 

 sufficient in themselves to warrant the conclusion that it is 

 removed by the liver. This, however, is put beyond a doubt 

 by the preceding analyses of the blood going to and. coming 

 from this organ. 



In treating of the composition of the feeces, we have con- 

 sidered so fully the changes which the cholesterine of the bile 

 undergoes in its passage down the intestinal canal, that it 

 is not necessary to refer to this portion of the subject again. 1 

 We have made but one examination of the quantity of ster- 

 corine contained in the daily fecal evacuation, and assuming 

 that the amount of cholesterine excreted by the liver in 

 twenty-four hours is equal to the amount of stercorine found 

 in the evacuations, the quantity is about ten and a half 

 grains. This corresponds with the estimates of the daily 

 quantity of cholesterine excreted, calculated from its propor- 

 tion in the bile and the estimated daily amount of bile pro- 

 duced by the liver. 



To complete the chain of the evidence leading to the 

 conclusion that cholesterine is an excrementrtious principle, 

 formed in certain of the tissues and eliminated by the liver, 

 it is only necessary to show that it is liable to accumulate in 

 the blood when the eliminating function of the liver is in- 

 terrupted. It will be remembered that it was only after ex- 

 tirpation of the kidneys, followed by accumulation of urea 

 in the blood, that Prevost and Dumas were able to demon- 

 strate the preexistence of this principle in the circulating 

 fluid, and indicate the mechanism of its separation from the 

 blood by the kidneys. This mode of study has been applied 

 to certain of the elements of the bile, though without suc- 

 cess; for Muller, Kunde, Lehmann, and Moleschott, who 

 have extirpated the livers from frogs, looked in the blood 



1 See vol. ii., Digestion, p. 399, et seq. 



