146 OILY OXIDES NOT SAPONIFIABLE. 



imperfectly examined. The most important of them are Mar- 

 garon, Ethal, and Cholesterin, of which an account will be given 

 in the following sections. 



SECTION I. OF MARGARON. 



This substance was discovered by M. Bussy in 1833.* He 

 obtained it by distilling a mixture of four parts of margaric acid 

 and one part of quicklime. A detailed account of it has been 

 given in the Chemistry of Vegetable Substances, (p. 120.) It 

 has been examined since with great accuracy by Messrs Redten- 

 bacher and Varrentrapp. M. Redtenbacher found that it con- 

 stituted one of the substances formed when stearic acid is sub- 

 jected to distillation.f Varrentrapp repeated the experiments of 

 Bussy, and purified the margaron first by digestion in potash, 

 and then by repeated solutions in ether and crystallizations.:]: 



It is a white, pearly, scaly, crystallized substance, melting ac- 

 cording to Redtenbacher, at 170.5, according to Varrentrapp 

 at 169, according to Bussy at 170. These slight differences pro- 

 bably are owing to errors in the thermometers used. 



Margaron was analyzed by Bussy, Redtenbacher, and Varren- 

 trapp. The result obtained was as follows : 



Bussy. Redtenbacher. Varreritrapp. Mean. 



Carbon, . 82-22 82-483 81-62 82-108 

 Hydrogen, 13-51 13-863 13-80 13-724 



Oxygen, . 4-27 3-653 4-58 4-168 



100-00 100-000 100-00 100-000 

 These results approach each other very closely. As margaron 

 neither combines with acids nor bases ; and as it cannot be dis- 

 tilled over without decomposition, we cannot ascertain its atomic 

 weight But, if from the formula for hydrous margaric acid we 

 subtract an atom of carbonic acid and an atom of water, the re- 

 mainder will agree with the preceding analysis of margaron. 

 Hydrated margaric acid is . C 34 H 34 O 4 

 Subtract 1 atom carbonic acid, C O 2 



And 1 atom water, . . HO 



Remain, C 33 H 33 O 



* Ann. de China, et de Phys. liii. 398. 

 f Annalen der Pharm. xxxv. 57. \ Ibid. p. 80. 



