QUANTITY OF BILE. 255 



is but one conclusion to be drawn from them ; and that is, 

 that bile may be secreted from either venous or arterial 

 blood. This view is not inconsistent with what we know 

 of the general process of secretion and its applications to 

 the production of bile. Regarding the bile as in part an 

 excrementitious fluid, its effete element cholesterine is 

 contained both in the blood of the portal vein and in the he- 

 patic artery. Its recrementitious principles glycocholates, 

 taurocholates, etc. we suppose are produced de novo in 

 the liver, out of materials furnished by the blood. The 

 exact nature of the production of elements of secretion by 

 glandular cells we do not understand ; but there is no good 

 reason to suppose that the principles necessary for the for- 

 mation of bile may not be furnished by the blood of the 

 portal vein, as well as by the hepatic artery. 



The view most nearly in accordance with all the facts 

 bearing on the question is, that bile is produced in the liver 

 from the blood distributed in its substance by the portal 

 vein and the hepatic artery, and not from either of these 

 vessels exclusively ; and that the bile may continue to be se- 

 creted, if either one of these vessels be obliterated, provided 

 the supply of blood be sufficient. 



Quantity of JSile.^-The estimates of the daily quantity 

 of bile in the human subject must be merely approximative ; 

 and our only ideas on this point are derived from experi- 

 ments upon the inferior animals. The most complete and 

 reliable observations on this subject are those of Bidder and 

 Schmidt, and were made upon animals with a fistula into the 

 gall-bladder, the ductus conimunis having been tied. 1 These 

 observers found great variations in the daily quantity in dif- 

 ferent classes of animals, the quantity in the carnivora being 

 the smallest. Applying their results to the human subject, 

 assuming that the amount is about equal to the quantity 

 secreted by the carnivora, the daily secretion in a man 



1 BIDDER UND SCHMIDT, Die Verdauungssafte, Leipzig, 1852, S. 209. 



