CHOLESTERES'E. 271 



without decomposition. The determination of the fusing 

 point is one of the means of distinguishing it from seroline, 1 

 which fuses at 90 8'. 



Without considering in detail the processes which have 

 been employed by other observers for the extraction of cho- 

 lesterine from the blood, bile, and various tissues of the body, 

 we will simply describe the method which has been found 

 most convenient in the various analyses we have made for 

 this substance. In analyses of gall-stones, the process is very 

 simple ; all that is necessary being to pulverize the mass, 

 extract it with boiling alcohol, and filter the solution while 

 hot, the cholesterine being deposited on cooling. If the crys- 

 tals be colored, they may be redissolved, and filtered through 

 animal charcoal. This is the process employed by Poulletier 

 de la Salle, Fourcroy, and Chevreul. It is only when this 

 substance is mixed with fatty matters, that its isolation is a 

 matter of any difficulty. In extracting cholesterine from 

 the blood, we have operated on both the serum and clot, and 

 in this way have been able to demonstrate it in greater quan- 

 tities in this fluid than have been observed by others, who 

 have employed only the serum. The following is the pro- 

 cess for quantitative analysis, which was determined upon 

 after a number of experiments : 



The blood, bile, or brain, as the case may be, is first care- 

 fully weighed, then evaporated to dryness over a water-bath, 

 and pulverized in an agate mortar. The powder is then 

 treated with ether, in the proportion of about a fluidounce 

 for every hundred grains of the original weight, for from 

 twelve to twenty-four hours, agitating the mixture occasion- 

 ally. The ether is then separated by filtration, throwing a 

 little fresh ether on the filter so as to wash through every 

 trace of the fat, and the solution set aside to evaporate. If 

 the fluid, especially the blood, have been carefully dried and 

 pulverized, when the ether is added, it divides it into a very 

 fine powder and penetrates every part. After the ether has 



1 LEHMANN, loc. cit. 



