MABERY. — THE COMPOSITION OF PETROLEUM. 573 



Combustion I. was made of the unpurified distillate dried over sodium ; 

 and combustion II., of the oil after treatment with fuming sulphuric 

 acid : — 



I. 0.1440 grm. of the oil gave 0.4500 grm. C0 2 and 0.1919 grm. 11,0. 

 II. 0.1608 grm. of the purified oil gave 0.5002 grm. C0 3 and 0.2198 grm. 

 H 2 0. 



Calculated for Found. 



C„H 32 . I. II. 



C 84.92 85.21 84.87 



H 15.08 14.80 15.20 



In determining the boiling point of pentadecane under atmospheric 

 pressure, it distilled almost completely at 256°-257°. 



A determination of the index of refraction gave 1.4413, from which 

 the molecular refraction was calculated : — 



Calculated for C 15 H 32 . Found. 



71.15 70.49 



Dichlorpentadecane, C 15 H 30 C1 2 . — With the small quantity of the hy- 

 drocarbon at hand, we did not succeed in limiting the action of chlorine 

 to the formation of the monochloride. Fractioned in vacuo under 13 mm. 

 the chlorinated product collected for the most part at 175°-180°. This 

 product gave as its specific gravity at 20°, 1.0045. A Carius determina- 

 tion for chlorine gave the following percentage : — 



0.1411 grm. of the oil gave 0.1462 grm. AgCl. 



Calculated for C^HjuCIj. Found. 



CI 25.28 25.63 



The molecular formula was established by a determination of its molec- 

 ular weight : — 



1.4308 grm. of the oil and 18.53 grms. benzol gave a depression of 1.336. 



Calculated for C 10 H 30 C1 2 . Found. 



281 283.2 



Hexadecane, C 16 H 34 . 



The heap that collected at 174°-175°, 50 mm., after the thirtieth 

 distillation gave as its specific gravity at 20°, 0.8000. After treatment 

 with concentrated sulphuric acid it gave 0.7964, and after treatment with 

 fuming sulphuric acid, 0.7911. It distilled almost completely at 275°— 



