225 



Hydrocarbons separable by Sulphuric Acid and Nitric Acid. 



The proportion of hydrocarbons removeable from the various distil- 

 lates by means of concentrated sulphuric acid, nitric acid, or a mix- 

 ture of both acids, is in most cases small when compared with the 

 part not acted upon ; it increases generally, however, with the boiling- 

 point of the fluid, varying from less than one-tenth to nearly one-third 

 part of the original compound-hydrocarbon. The nitro-compounds 

 obtained by means of strong nitric acid are fluids at the lower end of 

 the series, whilst with hydrocarbons boiling above 200 C. (392 F.) 

 they are of a resinous consistence ; they frequently retain with obsti- 

 nacy a portion of the not-acted-upon hydrocarbons, and more espe- 

 cially if the experiment be conducted upon a small scale; nitro- 

 compounds are sometimes obtained which float upon water, in con- 

 sequence of this retention of the lighter hydrocarbons. 



In submitting the hydrocarbons to the action of the acids, we have 

 invariably selected fluids which from their boiling-points appeared to 

 be within certain limits homogeneous ; but notwithstanding every pos- 

 sible care in this selection, we have always obtained more than one 

 sulpho-acid and more than one nitro-compound, as the case might be, 

 and we have experienced very considerable difficulties in the separa- 

 tion of the mixed products. In the case of nitro-compounds, advan- 

 tage has sometimes been taken of their convertibility by a mixture 

 of sulphuric and nitric acids into di- and tri-nitro-compounds, which 

 admitted of fractional crystallization from various media. We have 

 been thus enabled to isolate the following compounds, the analysis and 

 properties of which place their existence beyond doubt, namely, 



Nitrobenzol, 

 Dinitrotoluol, 

 Trinitroxylol, 

 Sulphocumolate of barium ; 



and therefore it is evident that the Burmese naphtha products contain 

 the corresponding hydrocarbons, namely, 



Benzol C 12 H 6 



Toluol 14 H 8 



CH 



