t72 On certain Products of Decomposition of the Fixed Oils. 



These results approximate to a formula similar to that of 

 the mercury compound ; viz. — 



(C8H8S2+PtCg + (C8H8S, + PtS). 



100-00 5757*7 



The analogy which those substances bear to allyle is exceed- 

 ingly interesting, as showing the possibility of forming, by 

 artificial processes, substances similar in constitution to so 

 remarkable a compound, which is not a product of decompo- 

 sition, but exists ready-formed in a variety of different vege- 

 tables, where it must obviously be produced under circum- 

 stances very different from the artificial substance ; for allyle 

 cannot exist at all at a high temperature, and is entirely de- 

 composed at, or even below, its point of ebullition. Unfor- 

 tunately, however, the examination of this substance is much 

 complicated by the necessity of examining its compounds in 

 place of itself. Had it been possible to separate it directly 

 from the crude oil, the determination of its constitution and 

 that of its compounds would have presented comparatively 

 little difficulty, and been arrived at with much less labour than 

 that expended upon the imperfect details I have been able to 

 accumulate. Another point worthy of observation, is the total 

 alteration of the products of decomposition of oleic acid pro- 

 duced by the presence of sulphur ; no sebacic acid, and, in 

 fact, none of its ordinary products being evolved, although all 

 the substances produced contain carbon and hydrogen in the 

 proportion of equal atoms, just as they exist among the ordi- 

 nary products, — a circumstance which, taking into considera- 

 tion the abundant evolution of sulphuretted hydrogen, we 

 certainly should not have anticipated. 



The oil which remains after the separation of the mercury 

 compound, likewise contains sulphur as one of its constituents ; 

 but I have not yet had time to commence the investigation of 

 this part of the subject. The discussion of it, as well as va- 

 rious other points connected with the compounds already de- 

 scribed, I hope to make the subject of a future communica- 

 tion. 



