MABERY. — COMPOSITION OF PETROLEUM. 263 



doubtless consisted, for the most part at least, of ethyl toluol, boiling 

 point 161°-162°, but no further attempts were made to identify it. 



The specific gravity of the residual oil was 0.7841, practically the 

 same as the specific gravity of dekanaphtene, 0.783, separated by 

 IMarkownikoff and Oglobine from Baku petroleum. Its odor is pre- 

 cisely similar to that of the corresponding hydrocarbon which one of us 

 (Mabery) has separated from crude Baku oil. 



Analysis of the unpurified distillate gave the following values : — 



I. 0.14G2 grm. of the oil gave 0.4724 grm. CO., and 0.1524 grm. HjO. 

 II. 0.1496 grm. of the oil gave 0.4844 grm. CO2 and 0.1564 grm. HoO. 



Found. 



C 88.10 88.28 



H 11.57 11.61 



After treatment with the acid the composition was materially changed ; 

 the results correspond closely to the composition of dekanaphtene : — 



0.1481 grm. of the oil gave 4646 grm. CO2 and 0.1932 grm. HoO. 



Calculated for CioHjo- Found. 



C 85.70 85.55 



H 14.30 14.50 



A determination of the molecular weight gave a value required for 

 dekanaphtene. 



0.8850 grm. of the oil and 24.22 grms. benzol gave, by the Beckman 

 method, at the freezing point, a depression of 1°.28. 



Calculated for CiqHjo. Found. 



140 140 



After the twenty-fourth distillation, 50 grms. collected at 169°-170°, 

 which gave as its specific gravity without purification, 0.8358. After 

 thorough agitation with fuming sulphuric acid and washing, the specific 

 gravity was reduced to 0.7749, but the larger portion of the oil was 

 removed by the acid, indicating that the fraction consisted for the most 

 of a benzol homologue. The small (juantity remaining after the treat- 

 ment was doubtless dekanaphtene, since its specific gravity was nearly 

 the same. 



The presence of a naphtene in Russian oil, boiling at 182°, led us 

 to believe that the same body should be found in California oil. But 



