MABERY. — ON THR COMPOSITION OF PETROLEUxM. 351 



The quantity of the solid hydrocarbon obtained was small, evidently 

 not suiricient to infliience the proportions of carbon and hydrogen in the 

 unfiltered distillate. While the amount obtained was not enough for 

 a determination of its molecular weight, its melting point and specific 

 gravity, the same as those of the hydrocarbon tetracosane separated 

 from paraffiiie distillate 272°-274°, indicate that it has the same com- 

 position. 



Tetracosane obtained by KrafFt,* by reduction of the ketone derived 

 from barium stearate and barium heptylate, melted at 51°. But the 

 specific gravity of KrafFt's hydrocarbon was somewhat lower than that of 

 the hydrocarbon from petroleum. 



The quantities of the distillates between 274° and 316° were too 

 small to permit of a separation of crystalline hydrocarbons in sufficient 

 amounts for identification of individual constituents. 



The pasty solid collected at ol6°-3I8°, 50 mm., yielded a solid hydro- 

 carbon by crystallization from alcohol and ether that melted at G6°. 

 The crude distillate gave as its specific gravity at 20°, 0.8212. A com- 

 bustion gave values required for the series CnHon.o. 



0.15G4 gram of the substance gave 0.4935 gram CO., and 0.1930 

 gram HoO. 



Calculated for Hentricontane, CjjHjj. Found. 



C 86.15 86.05 



H 13.85 13.80 



The purified solid gave as its specific gravity at 70°, 0.7997. 

 A combustion gave numbers for carbon and hydrogen required for the 

 series CnH.,n^.2. 



0.1499 gram of the substance gave 0.4698 gram CO., and 0.1969 

 gram H.2O. 



The formula of this hydrocarbon was further verified by its molecular 

 weight. 



0.3648 gram of this substance and 12.12 grams naphthaline gave a de- 

 pression of 0.471. 



Calculated for C31H1-4. Found. 



436 441 



* Ber. Deutsch. chem. Gesellscli., 15, 1718 (1882). 



