
OF THE FIXED OILS IN CONTACT WITH SULPHUR. 378 
obviously be produced under circumstances very different from the artificial sub- 
stance; for allyl cannot exist at all at a high temperature, and is entirely decom- 
posed at, or even below, its point of ebullition. Unfortunately, however, the ex- 
amination 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 produced 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 ordinary products,—a circumstance 
which, taking into consideration the abundant evolution of sulphuretted hydro- 
gen, we certainly should not have anticipated. 
The oil which remains after the separation of the mercury compound, like- 
wise 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 various other points connected with the compounds -already described, I 
hope to make the subject of a future communication. 
