MABERY. — THE COMPOSITION OF PETROLEUM. 577 



phuric acid; and combustion III., after treatment with fuming sulphuric 

 acid. 



I. 0.1423 grm. of the oil gave 0.4435 grm. C0 2 and 0.1915 grm. H,0. 



II. 0.1513 grm. of the oil gave 0.4702 grm. C0 2 and 0.2054 grm. H 2 0. 



III. 0.1524 grm. of the oil gave 0.4727 grm. C0 2 and 0.2064 grm. H 2 0. 



It is evident from the slight change in specific gravity after purifica- 

 tion, and the percentages of carbon and hydrogen, that the original 

 distillate consisted to a large extent of octodecane. 



Monochloroctodecane, C 18 H 37 C1. — The product obtained by the action 

 of chlorine on octodecane, collected in greater part at 185°-190°, under 

 15 mm., and this fraction gave as its specific gravity at 20°, 0.9041. 

 The percentage of chlorine corresponded to the monochloride : — 



0.1482 grm. of the oil gave 0.0782 grm. AgCl. 



Calculated for C 18 H 37 C1. Found. 



CI 12.35 13.05 



The results given above were obtained with the hydrocarbon that was 

 liquid at ordinary temperatures. When it was found that crystals sepa- 

 rated from this distillate at 3°, and that it became pasty at 0°, it was 

 cooled to —10°, when it became so thick it filtered only slowly. The 

 solid after filtering was melted and again cooled and filtered, after which 

 it was perfectly white. It was then crystallized from ether and alcohol, 

 after which it melted at 20°. It was estimated that twenty per cent of 

 the original oil separated as the solid hydrocarbon on cooling. It was 

 difficult to separate the solid completely on account of the great solvent 

 action of the oil. 



The filtered and pressed solid melted at 20°, and after crystallization 

 from ether and alcohol and from gasoline, the melting point could not be 

 raised. Kraff t * gave 28° as the melting point of octodecane, which he 

 obtained from stearic acid; but his octodecane boiled at 2 14°. 5 under 

 50 mm. pressure. The specific gravity of the solid hydrocarbon was 



* Ber. deutsch. chera. Gesellsch., XV. 1703 (1882). 

 vol. xxxvu. — 37 



