50 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Hydric sulphide escaped in small quautities during the distillation, 

 but below 2(30° the decomposition was slight, and the distillates were 

 colorless. Above this point the products were somewhat colored, 

 with the disagreeable odor of decomposition. It is probal)le that 

 cracking begins near this temperature, affecting the unsaturated hydro- 

 carbons if they are present, and perhaps other series as well as the 

 sulphur compounds. Certain constituents of the Canada oil seemed 

 to be more unstable than those of Ohio petroleum. The tendency 

 toward polymerization of unsaturated hydrocarbons separated from dis- 

 tillates corresponding to burning oil has been observed by me.* An oil 

 that had been distilled many times in vacuo and allowed to stand two 

 years, when again heated suddenly polymerised into a higher product 

 that could not be distilled at any temperature on account of complete 

 decomposition. The conversion of Canadian petroleum into asphalt, 

 upon long standing exposed to the weather, is well known. Large 

 masses of this material may be seen in a pitchy form in the vicinity of 

 Oil Springs. 



Determinations of carbon and hydrogen were made in the coke from 

 Petrolia oil, in one sample from the crude oil, and in another from a 

 tar distillate with the followino: results : — 



A specimen of " surface " oil was collected at Oil Springs for exam- 

 ination. It was very thick, with the consistency of ordinary molasses. 

 A determination of its specific gravity at 20° gave 0.9059. It con- 

 tained 0.05 per cent of nitrogen, and 0.95 per cent of sulphur. The 

 weight of bromine absorbed was equivalent to 25.46 per cent. This 

 oil is evidently an intermediary product in the formation of the deposits 

 of pitch resembling asphalt, which have long been known at Oil 

 Springs, The pitch is evidently formed by evaporation from the oil of 

 the more volatile constituents, and its formation is doubtless due, in 

 part at least, to polymerization of lower constituents of less stability. 

 A combustion of this pitch gave 64.86 per cent of carbon and 8.13 

 per cent of hydrogen. In a determination of nitrogen 0.40 per cent 

 was obtained, and the percentage of sulphur was found to be 0.65, 

 The pitch contained 10.13 per cent of ash, and a qualitative examina- 

 tion showed that it was composed chiefly of calcic oxide, with smaller 



* Amer. Chem. Journ., 1894, p. 92. 



