. procured from Caoutchouc by destructive Distillation. 323 



f I must, however, mention here a singular fact. Having 

 myself subjected caoutchouc to destructive distillation, I ob- 

 tained none of Mr. Enderby's oil; but on adding sulphuric 

 acid to the more volatile products, I got what I conceived to 

 be impure eupion. My failure in procuring the new oil I 

 ascribe to a difference in the temperature employed. 

 . Professor Liebig is inclined to the opinion that the other 

 substances described by Reichenbach are products of reaction, 

 and not educts. But I venture to remind him that creosote, 

 for example, may by detected in tar, by its smell and by its 

 antiseptic virtue ; that, according to Reichenbach, both eupion 

 and paraffins may be sufficiently purified, by rectification 

 alone, to exhibit their characteristic properties; and that pa- 

 raffine may be extracted from the petroleum of Rangoon, in a 

 state of absolute purity, without the employment of any more 

 active solvent than sulphuric ffither. 



M. Hess, in a note read in the Imperial Academy of Sci- 

 ences of St, Petersburg, on the lith of March* 1836, men- 

 tions some circumstances which are highly interesting in re- 

 ference to the present subject. After referring to the analogy 

 of the oil of petroleum with the eupion of Reichenbach, (an 

 analogy which I had demonstrated in a paper read to the 

 Royal Society of Edinburgh in December 1S34, and since 

 published in their Transactions,) he states that in following 

 Reichenbach's process for the preparation of eupion from oil 

 he obtained a liquid of sp. gr. 0'71, which by the action of 

 potash he obtained at last so light as 0'64?8, and boiling from 

 m" Fahr, to 110° Fahr. 



This liquid he found to have the composition of olefiant 

 gas ; it contained, he says, but very little eupion, which might 

 be separated by sulphuric acid. 



. Now my experiments above described render it extremely 

 probable that M. Hess's liquid is identical with that of Mr. 

 Enderby; and that the oil separated from it by sulphuric 

 acid is not eupion, but the second oil analysed by me. 



As M. Hess had previously shown that the pure oil of pe- 

 troleum had the same composition as olefiant gat, and was in 

 its properties, as 1 had also proved, very analogous to eupion, 

 he thinks it highly probable that the composition of eupion is 

 the same. 



He then proceeds to divide the very numerous compounds, 

 which agree in containing, like olefiant gas, about 85'7 per 

 Cent, of carbon, and 14'*3 per cent, of hydrogen, into two 

 series. The one, of wliich paraffine, eupion, and olefiant gas 



' Annahs dc Chimk, vol, Ixi. p. 331. 

 2 P2 



