346 PROCEEDINGS OP THE AMERICAN ACADEMY. 



The higher distillates were not examined, since the results described 

 above are sufficient to establish the composition of the main body of the 

 crude oil. The difficulties in obtaining hydrocarl)ons at these high tem- 

 peratures at all well fractioned, and analytical values to decide their 

 composition, are very great. Itis evident that the series of hydrocarbons 

 which compose Santa Barbara petroleum explain the peculiar nature of 

 this oil, which is unlike any other petroleum that has been examined in 

 this laboratory. The most volatile distillates are composed of the series 

 C„H2n_2> 3.nd the proportions of hydrogen gradually fall off through the 

 series C„H2„_4 and CnH2„_,>^. This change in series is accompanied with 

 a corresponding increase in specific gravity. These viscous hydrocarbons 

 evidently approach the constituents of the asphaltic oils and natural tars. 

 It is easy to see how petroleum is converted by slow evaporation in 

 nature into the great beds of tars and asphalts, and it affords the most 

 probable explanation of their formation. 



The hydrocarbons described in this paper, with their boiling points 

 and specific gravity, are brought together in the following table : 



Hydrocarbons separated from Santa Barbara (Cal.) Petroleum. . 



Symbol. Boiling Point. Specific Gravity at 20°. 



Hydrocarbon C13H24 150°-155°, 60 mm. 0.8G21 



CieHso 1750-180°, " 0.8808 



« CivHso 190°-195°, " 0.8919 



" C18H3., 210°-215°, " 0.8996 



« C.2iUn 250°-25o°, " 0.9299 



" C.27H48 310°-315°, " O.njol 



" CgyHjo 3i0°-345°, " 0.9778 



IV. SEPARATION OF SOLID PARxVFFINE HYDROCARBONS FROM 

 PETROLEUM WITHOUT EVAPORATION. 



By Cuakles F. Mabert and Otto J. Sieplein. 



By the method of distillation, which is the only means for the separa- 

 ration of the petroleum hydrocarbons, it is not possible to determine 

 whether the solid paraffine hydrocarbons are contained in the crude oil 

 or whether they may not be formed by decomposition. 



As a direct proof that the solid hydrocarbons are actually contained 

 in petroleum we have separated them without distillation. Three kilos 

 of an average specimen of Pennsylvania crude petroleum was allowed to 

 stand in a shallow pan exposed to a current of air in a strong flue draft 



