288 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



Calculated for solid 



70° 

 80° 



Distillate, 50mm. 300°-301°. C 27 H 56 . 

 Per cent of solvent, 77.64 

 " " " solid, 20.36 



70° 

 80° 



gr. of mixture. 



0.7719 

 0.7623 



Sp. gr. of solid. 



0.7757 

 0.7655 



Angle for mixture. 



49° 55' 

 50° 29' 4" 



Calculated for solid : 



Molecular Refraction. 



n. 



1.4292 

 1.4257 



Theoretical. 



Having at hand a series of solid hydrocarbons separated from com- 

 mercial paraffine, that correspond in composition to the solid hydrocar- 

 bons from crude Pennsylvania petroleum, determinations of the indices 

 of refraction of these bodies were made for the purpose of comparison. 

 The formulas of the paraffine hydrocarbons are given as they have been 

 determined, although the results have not been published. 



Distillate, 50mm. 260° -262°. C 23 H 18 . 

 Per cent of solvent, 79.84. 

 " " " solid, 20.16. 



