MABERY. — COMPOSITION OP PETROLEUM. 279 



Heptamethylene, C 7 H u . 



Tlie fraction 96°-98° gave as its specific gravity at 20°, 0.7479, and 

 after purification with fuming sulphuric acid, 0.7436. A combustion of 

 the purified oil gave the following results : — 



0.1530 grm. of the oil gave 0.4801 grm. C0 2 and 0.1974 grm. H 2 0. 



These values leave no doubt that this constituent was heptamethylene. 



OCTONAPHTENE, C 8 H 16 . 



A determination of the specific gravity of the fraction 11 8° -120° at 

 20° gave 0.7628, and after agitation with fuming acid and sodic 

 hydrate, 0.7569. Determinations of carbon and hydrogen were made 

 both before and after purification. 



I. 0.1644 grm. of the unpurified oil gave 0.5196 grm. C0 2 and 

 0.1975 H 2 0. 

 II. 0.1470 grm. of the purified oil gave 0.4600 grm. C0 2 and 0.1976 

 grm. H 2 0. 



Although all these oils were dried over sodium, the hydrogen in 

 analysis II. is somewhat too high, probably on account of a trace of 

 moisture. 



No further examination of the higher fractions of this oil below 160° 

 was made, except of the portions collected at 135°— 140°, to show that 

 large proportions of the xylols were contained as in the other specimens 

 examined. 



Dekanaphtene, C 10 H 20 . 



The specific gravity of the fraction 158°-160° was found to be 

 0.7848, and after agitation with the fuming acid, 0.7751. The propor- 

 tions of carbon and hydrogen were determined by analysis : — 



