544 PROCEEDINGS OF THE AMERICAN ACADEMY. 



The following values were obtained for the specific heats of these 



hydrocarbons : 



B. p. Sp. Heat. 



From data obtained with the paraffine hydrocarbons, tliere is no 

 opportunity to compare the specific heats, although the sudden drop 

 from the last member examined of the series CnH2n_|_2' Ci6H34, specific 

 heat .4957, to the first member of the last series above in which the 

 solid hydrocarbon C16H32 had been removed by cooling and filtration, 

 specific heat .4723, shows a marked diflference in structure. This rela- 

 tion appears in the longer curve in the table. 



Comparing the last member of the series CnHo^ from California oil 

 C15H00, specific heat .4708, with the hydrocarbon CicHso, specific heat 

 .4746, it appears that the series ChHoq from Pennsylvania petroleum is 

 a continuation of the same series from California petroleum. Unfortu- 

 nately the higher members of the series from California petroleum were 

 not available for comparison. But results already obtained as to the com- 

 position, specific gravity, refractive index, &c., are in accord with the 

 specific heats. The specific heat was also determined in several hydro- 

 carbons of the series CnHon^o^ ^^^^ the series C„H2n_4, which had been 

 separated from Texas petroleum with the following results : 



The latter results cannot be accepted as reliable, for the quantities of 

 the hydrocarbons were very small, and the oils began to crystallize at 0° . 

 There is no doubt that the specific heats of these hydrocarbons are smaller 

 than those of the preceding series. 



