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, there is no 

 opportunity to compare the specific heats, although the sudden drop 

 from the last member examined of the series C n H 2n+2 , C 16 H 34 , specific 

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

 solid hydrocarbon C 16 H 32 had been removed by cooling and filtration, 

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

 tion appears in the longer curve in the table. 



Comparing the last member of the series C n H 2n from California oil 

 C 15 H 30 , specific heat .4708, with the hydrocarbon C 16 H 82 , specific heat 

 .4746, it appears that the series C n H. 2a 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 C n H 2n _ 2 , and the series C n H 2n _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. 



