258 PROCEEDINGS OF THE AMERICAN ACADEMY. 



ulation to avoid loss in transferring to the combustion tube, and as will 

 ajapear later, the highest temperature that the hardest tube will stand is 

 necessary for complete combustion. Tliese results seem to indicate that 

 the oil was a mixture of hexane and hexamethylene. The slight change 

 in specific gravity after treatment with fuming sulphuric acid and potassic 

 hydrate shows that the benzol had been almost completely removed. 

 The fractions at 68° appear to be the last in California oil containing 

 members of the series C„H2„+2 . Since small quantities of distillates 

 collected in the vicinity of 60°, 38°, and in one specimen at 30°, it is 

 probable that the very light gasoline from California oil has the same 

 composition as that from Pennsylvania oil. 



The specific gravity of hexane, 0.6630 at 18°, and of hexamethylene, 

 0.690, also indicate that the fraction 68° -70° is a mixture of these two 

 hydrocarbons. 



HePTAMETHYLENE, C7H14. 



The distillate collected at 96° -98° amounted to fifty grams. Before 

 purification it gave as its specific gravity 0.7499, and after purification, 

 0.7413. Tlie specific gravity of heptane boiling at this point is 0.6440 

 (20°. 5). Beilstein and Kurbatoff gave 0.742 at 18° as the specific grav- 

 ity of heptanaphtene. A combustion gave the following percentages of 

 carbon and hvdrogen : — 



0.1413 grm. of the purified oil gave 0.4442 grm, CO2 and 0.1814 

 erm. HoO. 



»■ 



Found. 



C 85.70 80.74 



H 14.30 14;35 



A determination of the vapor density of the fraction 96°-98° by col- 

 lecting the vapor over mercury gave a value corresponding to the molec- 

 ular weight of heptamethylene. The determination was made by the 

 method of V. Meyer, in vacuo, essentially according to the modification 

 of Lunge and Neuberg : * — 



0.0494 grm. of the oil gave 22.9 c.c. under a tension of 373 mm. and 



at 24°. 



Calculated for CtH^^. Found. 



3.40 3.40 



* Ber. deutsch. Gesell., 1891, 729. 



