Chemical Nature of Wax. 219 



pursued was that used by Dumas with such success for the 

 conversion of alcohol into acetic acid ; of potatoe oil into vale- 

 rianic acid ; and for other similar transformations. He has 

 explained the reaction by giving to the cerine the formula 

 Cgg H 68 4 . On this hypothesis, the cerine, by conversion 

 into stearic acid, loses three equivalents of hydrogen and takes 

 up three equivalents of oxygen into its constitution, the reac- 

 tion being expressed by the equation 



C68H 68 4 + 3HO = C 68 H 68 7 +H 3 =|^ + H J> 



the cerine being considered the aldehyde of stearic acid. M. 

 Gerhardt has taken up and extended this idea. Proceeding 

 on the belief that the myricine and cerine are isomeric — 

 a belief, I may observe, not justified by experiment, although 

 almost universally adopted by chemists — he has stated that 

 the myricine, of which by far the larger portion of the wax 

 consists, corresponds to the metaldehyde of the same acid, and 

 in a paper which he entitles, " Faits pour servir a I'histoire 

 de la cire des abeilles*," has explained on this hypothesis the 

 origin of the products of the dry distillation of that substance. 

 The theory of M. Lewy agrees sufficiently well with his ana- 

 lyses of the substances in question and with the relations of 

 his formula?. I must however observe, that any person who 

 will take the trouble of reckoning out those analyses on which 

 the formula of stearic acid depends, according to the atomic 

 weight of carbon now almost universally adopted by chemists, 

 carbon 6, hydrogen 1, will see that this formula itself demands 

 a new inquiry before we can accept it. These results of M. 

 Lewy are in many ways at variance with my own experiments ; 

 but I confess that if the agreement of the analysis and of the 

 melting-point of the substance he obtained by oxidation of the 

 cerine with the analysis and the melting-point of stearic acid 

 were in truth a sufficient proof of the identity of the bodies, 

 this difference in our results would be to me very difficult to 

 explain. Wax certainly stands in a remarkable relation to 

 fat, but I do not believe that relation to be of the nature M. 

 Lewy has conjectured, and I cannot but think that, in his 

 desire to establish this relation, he has rested content with 

 insufficient proofs of his theory. Any person who has had a 

 little experience in these inquiries, must know how deceptive 

 this melting-point and analysis are as criteria of the purity or 

 identity of bodies. The separation of this class of substances 

 by crystallization is difficult, and often the composition per 

 cent, of two substances of entirely different chemical formulae 

 will agree within the unavoidable errors of the method of 

 * Annates de Chimie, vol. XV. p. 236. 

 Q2 



