304 PROCEEDINGS OP THE AMERICAN ACADEMY. 



refraction was 1.4516, and its molecular refraction, 50.78; required for 

 C11H20, 50.63. 



The specific gravity of the fraction 216° was 0.8327, and the molecu- 

 lar weight, 172; required for C12H24, 168. Its index of refraction was 

 1.4599, and its molecular refraction, 55.22; required for C12H04, 55.23. 



The specific gravity of these distillates from Ilirei oil is somewhat 

 higher than was found in the corresponding distillates from Amaze oil, 

 and the differences inci'ease with increasing molecular weights. It was 

 at first thought that this was due to incomplete removal of benzol hydro- 

 carbons, but still further treatment with fuming sulphuric acid failed to 

 diminish these values. It is probable that the oil contains hydrocarbons 

 with more than one methylene ring. 



The results of this examination show that Japanese petroleum is com- 

 posed for the greater part of hydrocarbons of the series C^Ho,,, — the 

 methylene hydrocarbons. Probably the very heavy oils contain hydro- 

 carbons with two or more methylene rings, of the series C„H2„_2 or 

 C,jH2„_4. Some of the oils contain solid paraffiiie hydrocarbons, others 

 do not. The proportion of benzol derivatives in the oils examined is 

 relatively much smaller than in California petroleum. The proportion 

 of nitrogen compounds and of sulphur compounds is quite variable. In 

 some of the oils the percentages were nearly as large as any found in 

 California petroleum, in others the amounts were much smaller. 



