25€ Mr. B. C. Broclie 07i Myricine. 



first analysed this substance*, concluded from its melting- 

 point, analysis, and general appearance, that it was identical 

 with paraffine, a hydrocarbon then recently discovered by 

 Reichenbach in the products of the dry distillation of wood. 

 The wax hydrocarbon has therefore borne the name of pa- 

 raffine. 



This substance was supposed, from the analyses of Ettling 

 and J. Gay-Lussac, to be isomeric with olefiant gas. 



Recently, however, this has been contested by Lewy, who 

 analysed paraffine from various sources, and showed it, as he 

 conceived, to contain a larger amount of hydrogen than had 

 been previously supposed. In truth the average of his analyses 

 gave,— 



Carbon .... 85*03 

 Hydrogen . . . 14;'87 



99-90 



numbers inconsistent with the old idea. The question how- 

 ever is, whether M. Lewy experimented with a pure chemical 

 substance, for which there is no guarantee. 



My own experiments confirm the analyses of Ettling, and 

 the constitution originally assigned to the substance, to which 

 theoretical considerations also lead. But I cannot see any 

 reason to believe the wax hydrocarbon to be identical with 

 the paraffine of Reichenbach. This name of paraffine has 

 been applied indiscriminately to the whole class of solid hy- 

 drocarbons, which have, or have nearly the formula C,„H^, 

 the identity of which has been taken for granted, in the abs- 

 ence of any true knowledge as to the chemical nature of the 

 substances from the decomposition of which by heat they are 

 produced. The different melting-points however of these 

 substances point out to us at once a distinction between them. 

 The paraffine of M. Lewy melted at 46°'8. A specimen of 

 the paraffine of wood given to me by Professor Liebig, and 

 which that gentleman received from Reichenbach, its disco- 

 verer, melted at 43°-5 C. ; Ettling's paraffine at 57° to 58" C. 

 I confess it is difficult for me to conceive what substance in a 

 state approaching to purity Lewy analysed from the wax 

 having the melting-point he has given, since nothing is easier 

 than to raise the melting-point of the paraffine from the wax 

 to 56° C, although beyond this any change is effected with 

 difficulty. 



Cerine alone gives on distillation hardly a trace of this hy- 

 drocarbon, while it forms a principal product of the distillation 

 of myricine. The palmitic acid is separated by saponification! 



* Liebig's Annalen, \o\. ii. p. 259. 



