DIGESTIVE SYSTEM, 2(5 1 



admit of the introduction of the little finger; and is about three 

 inches in length. It pierces the coats of the duodenum, six 

 inches distant from the stomach, in conjunction with the pan- 

 creatic duct, but opening by an orifice distinct from the one of 

 that duct : the terminations of both, however, are guarded by the 

 same circular flap, one composed of doublings of the inner and 

 muscular coats of the gut, which performs a valvular function 

 in preventing the intrusion of alimentary matters into these 

 tubes. 



The nerves of the liver, neither large nor numerous (for it does 

 not appear to possess much sensibility either in health or disease), 

 come principally from the sympathetic; it receives also a few 

 filaments from the par vagum. Its lymphatic vessels, on the 

 other hand, are extremely plentiful and are readily demonstrated : 

 we have nothing more to do than to insert a small injecting pipe 

 under its peritoneal capsule, and allow quicksilver to diffuse itself, 

 and we shall instantly fill very many of them, making a beautiful, 

 vascular, arborescent display upon the surface. 



Structure. — The hepatic artery having entered the substance 

 of the organ, disperses its ramifications through every part; and 

 they terminate not only in open nutrient points, but in vessels 

 of communication with all the others: at least, if fine injection 

 be thrown in, it will not only pass into the hepatic veins, but 

 also find its way into the branches of the vena portae, and those 

 of the hepatic duct as well. In fact, the researches of anatomy 

 appear to prove, that there is free intercommunication between 

 all these different sets of vessels ; for if either of the others are 

 injected (except the hepatic veins which have valves), the same 

 result is aflbrded. If a piece be torn or broken off the liver, we 

 shall perceive, on close inspection of the lacerated surface, nu- 

 merous little granulary eminences, to which anatomists have 

 given the name of aci/i?: these small bodies, which adhere to- 

 gether by means of a fine cellular web, are composed of the 

 ramifications of some or all of the vessels that have been men- 

 tioned ; but what their intimate structure is, or how or in what 

 manner they are constituted, remains yet to be explained. Again, 

 if we nicely examine the surface of a clean cut into its substance, 

 we shall perceive numerous minute pores, from which a yellowish 

 fluid may be expressed : these are the pori biliarii, the radicles 

 of the hepatic duct, which run in company with the arterial and 

 venous ramifications, repeatedly unite and re-unite, until, at 

 length, they all end in a single tube — the liepatic duct. 



BILE is a sort of soapy viscid fluid. Its viscidity it derives 

 from gelatine, which a solution of tannin or alcohol will precipi- 

 tate. By the agency of the latter, the gelatinous matter may be 



