MABERY. — COMPOSITION OP PETROLEUM. 259 



The high specific gravity of this hydrocarbon corresponding to that of 

 heptanaphtene, the composition given by analysis and the molecular 

 weight, leave no doubt that this body is a heptamethylene, and that 

 heptane is not contained in California (Fresno County) petroleum. 



Benzol. 



The distillates in the vicinity of 80°, especially 79°-81°, gave the 

 characteristic odor of benzol. 20.5 grms. of these fractions shaken be- 

 low 60° with a mixture of nitric and sulphuric acids, gave a heavy nitro- 

 product ; after washing with water and distilling, the distillate weighed 

 13 grms., showing that 35.5 per cent of this oil was benzol. Some of the 

 same fractions treated with fuming nitric acid deposited needle-shaped 

 crystals that melted at 89°-90°, the melting point of dinitrobenzol. 



Toluol. 



After the twelfth distillation, 60 grms. collected at 109°-110° with 

 the penetrating odor of toluol. 30 grms. of this distillate was shaken 

 with a mixture of nitric and sulphuric acids, and the oil not nitrated 

 separated from the nitro-product by distillation. The distillate weighed 

 13 grms., showing that 54 per cent of the original distillate was toluol. 

 Upon agitating this product with fuming sulphuric acid and distilling, 

 1.6 per cent more was removed. The remaining oil was dried over 

 sodium for analysis. 



The unpurified distillate gave the following values on analysis : — 



0.1584 grm. of the oil gave 0.5090 grm. C0 2 and 0.1663 grm. H 2 0. 



The change in composition by treatment with acids was very 

 marked : — 



0.1725 grm. of the purified oil gave 0.5387 grm. C0 2 and 0.2282 grm. 

 H 2 0. 



Evidently the small quantity of oil remaining after the treatment with 

 acids was octonaphtene, that had not been completely separated by 

 distillation. 



