352 PROCEEDINGS OF THE AMERICAN ACADEMY. 



From the ketone palmiton, C31HC2O, Krafft * prepared Hentricontane, 

 CaiHsi, M. P. G8°.l, which differs but slightly from that of the hydro- 

 carbon separated from petroleum, 66°. 



Since the soliil hydrocarbon formed such a small proportion of the 

 original distillate that it did not affect materially the composition of the 

 latter, this solid evidently could not be compared with the hydrocarbon 

 separated from the corresponding distillate from paraffine nor that from 

 crude Pennsylvania petroleum, for the predominating constituents should 

 materially affect the boiling points of all the minor solid constituents. 

 This is shown to be true by the high molecular weights and high melting 

 points of the hydrocarbons separated from Coreopolis distillates so far as 

 they could be determined. The distillate collected at 328°-330^, 50 mm., 

 after filtration from the solid, gave as its specific gravity at 70°, 0.8235. 

 After crystallization from ether and alcohol, the white crystalline solid 

 gave as its specific gravity at 70°, 0.7982. The proportions of carbon 

 and hydrogen given by combustion supported the formula of the series 

 CnH2n+2- The original distillate gave as its specific gravity 0.8217. A 

 combustion gave the following percentages of carbon and hydrogen. 



0.1586 gram of the substance gave 0.4995 gram COo and 0.1925 

 gram HoO. 



Calculated for CooU^b. Found. 



C 86.14 85.86 



H 13.86 13.57 



The solid purified from ether and alcohol gave proportions of carbon 

 and hydrogen corresponding to the series C„Ho„+2. 



0.1549 gram of the solid gave 0.4842 gram COo and 0.2075 gram HoO. 



Calculated for C;,JI,;c- Found. 



C 85.33 85.25 



H 14.67 14.98 



The melting point of the crystalline hydrocarbon was found to be 

 67°-68°. Its molecular weight at the boiling point of benzol and also 

 at the freezing point of naphthaline indicated the next higher homologue, 

 C^^.^Hcc, dotricontane, but the small quantity of substance available for 

 this determination was not sufficient to yield satisfactory results. 



The specific gravity of the unpurified distillate 342°-344°, 50 mm., 

 was 0.8288 ; after separation of the solid by freezing and purification 



* Ber. Deutsch. chem. Gesellsch., 15, 1714. 



