BILE. 



&c. at last unite into one large vein and ascend towards 

 the liver. Having entered this it divides into a multi- 

 tude of minute veins that are sent to every part of it, 

 and the extremities of which are said to communicate 

 with the extremities of the hepatic artery and veins. 

 What the object of this singular arrangement can be, is 

 not yet satisfactorily determined. By some it is thought 

 that the blood brought to the liver by the vena portae is 

 that from which the bile is secreted, and that the use of 

 the hepatic artery is only to nourish the organ. Others 

 believe that the hepatic artery furnishes not only the ma- 

 terials of its own nourishment, but those for the secretion 

 of bile, that the vena portae abounds with the products 

 of digestion which have been absorbed from the intestinal 

 canal, and are subjected to the action of theliver in order 

 that the useless portions may be separated from them and 

 the rest receive a higher degree of animalization. Neith- 

 er of these opinions is supported by direct proof, though 

 the latter is rendered quite plausible by numerous analo- 

 gies. 



The bile, as fast as it is formed, is transmitted drop 

 by drop by its proper duct into the intestinal canal. This 

 duct communicates with a small membranous sac, called 

 the gall-bladder, which contains a quantity of bile a lit- 

 tle changed in its properties, being of a greenish colour, 

 less watery, and more bitter and acrimonious. It is gen- 

 erally considered as a reservoir for the bile, when 

 digestion is not going on, and its presence consequently 

 not wanted. This view of its use however, is not uni- 

 versally received, but as the subject is yet very obscure, 

 it would be time unprofitably spent to detain you with 

 any farther speculations. Whatever may be its use, we 

 may be confident that it is not essential to the animal 

 economy, for in many quadrupeds, the deer for instance, 

 it is found wanting. 



Emily. Are physiologists any better acquainted with 

 the use of the bile, than they are with the manner in which 



