48 



PROCEEDINGS OP THE AMERICAN ACADEMY. 



those from oils of other fields. It is evident that the high specific grav- 

 ity of the Canadian and Ohio crude oils depends upon constituents 

 that do not distil below 350°. In this respect these oils differ essen- 

 tially from the Russian oil, in which all the distillates show a high 

 specific gravity. The distillates below 150° from Canadian oil are 

 somewhat lighter than the corresponding products from Ohio crude 

 oil. In considering later the properties of the vacuum distillates it 

 will be seen that these proportions are very materially changed by 

 distillation in vacuo. 



In the percentages of the lower fractions it will be seen that the 

 Canadian oil resembles more nearly that from the Caucasus, but the 



