MABERY AND HUDSON. — AMERICAN PETROLEUM. 113 



these weights are from G5 litres, the small amounts of the constituents 

 will be appreciated : — 



llo>^-116^ llG-"'-H7^ 1170-118° 118''-119^ 119M20^ 120''-121^ 12^-122° 



Grams 50 60 80 100 145 130 IGO 



122''-123^ 123"'-124'^ 124-^-125=' 125°-126=' 126°-127° 127°-128=' 128°-129° 



Grams 1-20 170 160 150 120 90 40 



If the distillation had been stopped at this point, since on account of the 

 diminished tension the true boiliug points should be at least one degree 

 higher than those given, it might be inferred that one of the principal 

 constituents was a hydrocarbon boiling at 126°-127^. 



No doubt this inference would be supported by the vapor density of 

 this product, but further distillation showed its fallacy. At the end of the 

 thirty-third distillation, 190 grams collected at 118°. 5-119°. 5, which 

 distilled between 119°. 5 and 120°, for the most part at 119°. 5, under 

 760 mm. with the mercury column wholly in the vapor. Its specific 

 gravity at 20° was found to be 0.7243. This liquid was assumed to 

 have the same composition as the octane whose identity was shown 

 by analysis and a vapor density determination.* 



The vapor density of this product was found to support the same 

 composition : — 



0.1287 gram of the oil gave 75 c.c. of vapor at 182°, and under a ten- 

 sion of 429 mm. 



Calculated for CjHu. Found. 



3.95 391 



The specific gravity of the crude distillate was found to be 0.7256. 

 The presence of this hydrocarbon is still further assured by the |)ro- 

 longed distillation. Our boiling point is practically the same as that 

 of Warren, although his product from Pennsylvania petroleum must 

 have been contaminated to some extent by hexahydroisoxylol, which 

 was not shown to be present in Pennsylvania oil until long after 

 the work of Warren was completed. Our boiling point was taken 

 in a portion of the Ohio oil which had been subjected to prolonged 

 treatment for the removal of hexahydroisoxylol. The specific gravity 

 of this distillate purified by fuming sulphuric acid with the aid of heat 

 was 0.7230. Another portion purified with a mixture of nitric and 

 sulphuric acids gave as its specific gravity 0.7190. In the oil with 



* Mabery, loc. cit. 



VOL. XXXII. — 8 



