MABRRY. CONSTITUENTS OF PETROLEUM. 131 



Auother portion of the crude distillate was agitated with a mixture of 

 nitric and sulphuric acids. An oily nitro product separated above the 

 acids, which became partially crystalline on standing. It was doubtless 

 a nitro derivative of cymol ; boiling point of metacymol 174°-176°, of 

 paracyraol 17l°-172°. 



The quantity of the nitro product was small, and the proportion of 

 cyniol was still further shown to be very small by treatment with fuming 

 sulphuric acid. 185 grams of the distillates 167°-170^, after the eighteenth 

 distillation, first by agitation in the cold, and then by warming to 125°, 

 gave a loss in weight of only 15 grams, or about 8 per cent of the weight 

 taken. A barium salt was formed of the sulphonic acid, but it appeared 

 as a thick gummy mass, so uninviting that nothing further was done with 

 it. The purification with fuming sulphuric acid was intended more espe- 

 cially to show whether the boiling point of the distillates would be mate- 

 rially affected. But the only difference observed was that they came 

 together more readily and completely within one degree, 169°-170° under 

 730 mm., and at 173°-174°, chiefly at 174°, under a tension of 760 mm., 

 with the mercury column all in the vapor. It is interesting to observe 

 how slightly the boiling point was affected by the removal of the contam- 

 inating bodies. Evidently, the principal influence of the latter was in 

 preventing the hydrocarbon from collecting closely at its true boiling 

 point. 



The remaining oil was boiled with sodium as lon^ as the metal was 

 atifected, and until it remained unchanged on standing with the oil. Even 

 after this treatment was repeated several times, the percentage of carbon 

 was somewhat too high and hydrogen too low : — 



0.1503 gram of the oil gave 0.4664 gram COo, and 0.2050 gram H2O. 



After this purification the specific gravity obtained was 0.7475. For 

 still further certainty as to the purity and composition of this distillate 

 another portion was warmed during several hours with fuming sulphuric 

 acid and shaken thoroughly. After washing and standing over sodium, 

 it was analyzed : — 



0.1754 gram of the oil gave 0.5431 gram CO.,, and 0.2442 gram HoO. 



