BILIVEKDINE. 273 



tions, the quantity of cholesterine in any fluid or solid may 

 be determined with perfect accuracy ; and the estimate may 

 be made in so small a quantity as from fifteen to twenty 

 grains of blood. In analyzing the brain and bile, we found 

 it necessary to pass the first ethereal solution through animal 

 charcoal, to get rid of the coloring matter. In doing this, 

 the charcoal must be washed with fresh ether till the solu- 

 tion which passes through is brought up to the original 

 quantity. The other manipulations are the same as in ex- 

 aminations of the blood. In examining the meconium, we 

 found that the cholesterine which crystallized from the first 

 alcoholic extract was so pure that it was not necessary to 

 subject it to the action of an alkali. 



The proportion of cholesterine in the bile is not very 

 large. In the table, it is estimated at^from 1*60 to 2*66 

 parts per thousand. In a single examination of the hu- 

 man bile, we found the proportion 0'618 of a part per 

 thousand. 



The origin and destination of this principle involve, as 

 we believe, an office of the liver which has not hitherto been 

 recognized by physiologists ; and we will consider these ques- 

 tions specially, under the head of the excretory function of 

 the liver. 



Biliverdine. 



The coloring matter of the bile bears a certain resem- 

 blance to the coloring matter of the blood, and is supposed 

 to be formed from it in the liver. It gives to the bile its 

 peculiar tint, and has, as we have remarked, the property of 

 coloring the tissues with which it comes in contact. When- 

 ever the flow of bile is seriously obstructed, the coloring 

 matter is absorbed by the blood, and can be readily detected 

 in the serum, in the urine, and in the color of the skin and 

 conjunctiva. In the bile it is liquid, but it may be coagu- 

 lated and extracted by various processes. It does not exist 

 naturally in the form of pigmentary granulations. 

 18 



