EXCRETORY FUNCTION OF THE LIVER. 287 



arterial blood, examining it as it went into the brain by the 

 carotid, analyzing the substance of the brain, then analyzing 

 the blood as it came out of the brain by the internal jugular, 

 examining the blood as it went into the liver by the hepatic 

 artery and portal vein, examining the secretion of the liver, 

 then the blood as it came out of the liver by the hepatic 

 vein, examining also the blood of the vena cava in the abdo- 

 men. The analyses of the blood from the carotid, internal 

 jugular, and vena cava have already been referred to in 

 treating of the origin of the cholesterine. It will be remem- 

 bered that there was a large quantity of this substance in 

 the internal jugular, and but a small quantity in the carotid, 

 showing that it was formed in the brain. "We now give the 

 conclusion of these observations, which bears upon the sepa- 

 ration of the cholesterine from the blood : 



Experiment I. Specimens of blood were taken from the 

 hepatic artery, portal vein, and hepatic vein, and a small 

 quantity of bile from the gall-bladder. These specimens 

 were treated in the manner already indicated ; i. e., evapo- 

 rated and pulverized, extracted with ether, the ether evapo- 

 rated, and the residue extracted with boiling alcohol, this 

 evaporated, a solution of caustic potash added, and the 

 specimen then subjected to a microscopical examination. 



Microscopical examination of the extract from the portal 

 vein showed quite a number of crystals of cholesterine. 

 These were observed after the fluid had nearly evaporated. 



Microscopical examination of the extract from the he- 

 patic artery, made after the fluid had nearly evaporated, 

 showed a considerable amount of cholesterine ; more than 

 was observed in the preceding specimen. There were also 

 observed a few crystals of stercorine. 



The first examination of the extract from the hepatic 

 vein, which was made just before the potash was added, 

 showed a number of fatty masses, with some crystals of ster- 

 corine. The solution of potash was then added, and two 

 days after, another careful examination was made, discov- 



