MABERY AND GOLDSTEIN. — SPECIFIC HEATS OF HYDROCARBONS. 543 



The constant, therefore, for the homologous series of hydrocarbons 



C„H„2+2, is 2.23. 



A similar curve drawn for the specific heats of the methylene hydro- 

 carbons, so far as they were determined, show also a regular variation. 



The constant K, for the methylene hydrocarbons calculated from the 

 determinations, shows a somewhat higher mean value than that of the 

 paraffiue hydrocarbons : 



The values for the specific heats of both hexane and hexamethylene 

 are higher than should be expected from the results on the other members 

 of the series. These hydrocarbons were well purified, except it seems 

 probable that the distillates contained certain proportions of both. 



Determinations were also made of the specific heats of a series of 

 hydrocarbons separated from the high boiling portions of Pennsylvania 

 petroleum. This series is under examination to establish its composition 

 and relations to series, separated from heavy petroleums from other 

 fields. These hydrocarbons were cooled to — 10°, and filtered to remove 

 so far as possible the solid hydrocarbons with which they are associated 

 in Pennsylvania petroleum. They have been shown to be members of 

 the series CnHan- A more detailed description of these bodies will be 

 presented in a subsequent paper, which is now in preparation. 



