408 LIQUID PARTS OF ANIMALS. 



Bile, after being secreted in these lobules of the liver, is con- 

 veyed by the small ducts to larger and larger ducts, till they 

 at last unite in one duct called the duclus hepaticus. In many 

 animals there is a cavity placed on the liver called the gall-blad- 

 der, into which the bile makes its way from the hepatic duct, 

 when not wanted for digestion. The duct by which it enters is 

 called the ductus cisticus. It joins the hepatic duct before it en- 

 ters the duodenum, and both together form one common duct 

 called the ductus communis choledochus. 



From the large size of the liver and of the biliary ducts, the quan- 

 tity of bile thrown into the duodenum must be considerable ; 

 though it has not been in the power of physiologists to form any 

 accurate estimate of it. According to Leuret and Lessaigne,* 

 the bile secreted by the liver of the horse amounts to two ounces 

 in a quarter of an hour. This would make the enormous quan- 

 tity of twelve pounds a-day. But as the horse has no gall-blad- 

 der, it is probable that bile is only secreted, or at least given out 

 by the liver, when that organ is excited by the stimulus of chyme 

 in the small intestines. 



Great attention has always been paid to this secretion by me- 

 dical men. The ancients ascribed a number of diseases and even 

 affections of the mind to its agency. Various observations on it 

 were made by Boyle, Boerhaave, Varheyen, Ramsay, and Baglivi. 



The first attempt to examine it seems to have been made by 

 Neumann, f He describes the characters of ox -bile, and says, that 

 it is neither acid, nor alkaline, nor soapy. It is coagulated by 

 acids, and slightly precipitated by carbonate of potash. Ammo- 

 nia occasions no alteration. Rectified spirits scarcely make it 

 cloudy. He subjected it to distillation, and noticed some of the 

 products, viz. water, ammonia, and oil. The residue contained 

 a fixed alkali. 



Cadet in his analysis of bile, \ published in 1767, added some 

 new facts. Alcohol throws down a substance from bile, which 

 he considered as gelatin. He shewed that the alkali in bile is 

 soda. 



Van Bochoute, Professor at Louvain, wrote in 1778 a Latin 

 dissertation containing important observations respecting the na- 



* Recherches Physiologiques et Chimiques pour servir a Ihistoire de la diges- 

 tion, p. 83. 



j- I quote from Lewis's translation, p. 566. This translation was published 

 in 1759, and contains much original matter. 

 Mem. Paris, for 1767, p. 471. 



