OILY OXIDES NOT SAPONIFIABLE. 



Ambrein, like cholesterin, is incapable of being converted 

 into soap, showing clearly that it does not possess acid properties. 

 Pelletier subjected ambrein to an ultimate analysis by means 

 of oxide of copper, and obtained, 



Carbon, . 83-37 



Hydrogen, . 13-32 

 Oxygen, . 3-31 



100-00 



As we do not know any substance with which ambrein com- 

 bines in definite proportions, we cannot determine its atomic 

 weight. This puts it out of our power to state the number of 

 atoms which enter into its composition. But the smallest num- 

 ber of atoms which correspond with the preceding analysis is the 

 following : 



33 atoms carbon, = 24-75 or per cent. 83-20 



32 atoms hydrogen, = 4. ... 13-44 



1 atom oxygen, = 1* ... 3-36 



29-75 100-00 



This would make the atomic weight 29*75. It is obvious, from 

 the quantity of oxygen, that the number of atoms cannot be 

 fewer than here stated ; but, for any thing that appears, they 

 may be double or triple that quantity. 



SECTION VI. OF CHOLESTERIN. 



This substance was noticed by Gren in 1789, as constitut- 

 ing the greatest part of a gall-stone which he subjected to a 

 chemical analysis.* He gave it the name of a waxy-looking sub- 

 stance. Chevreul afterwards examined its properties more in 

 detail, and stated that he had discovered it as one of the consti- 

 tuents of oils. He made its distinctive characters known in a 

 paper which was read to the French Institute in the year 1814. 

 The same subject was again taken up by him in his Recherches 

 Chimiques sur les Corps Gras, published in 1823,f In that work, 

 Chevreul assures us, that cholesterin was first obtained by Poul- 

 letier de la Salle by treating gall-stones with boiling alcohol. I 

 find this statement verified by Macquer, who, in the second edi- 



* Beytr. z. d. Chem. Annalen, iv. 19. f Sur les Corps Gras, p. 155. 



