MABERY. — ON THE COMPOSITION OF PETROLEUM. 341 



well, Summerlaiid, Santa Barbara County, Cal., representing the heavy 

 oil that is taken from wells sunk below the Pacific Ocean. An exam- 

 ination of this petroleum seemed desirable, especially since it is the 

 lieaviest specimen, with one exception, that has been examined in this 

 laboratory. It represents the last member of a series beginning with 

 the light yellow Berea Grit oil from Southern Ohio, which was found l)y 

 O. C. Dunn and me* to be the lightest petroleum that had come to our 

 knowledge. 



This work was undertaken by ]\Ir. C. V. Zoul.f Tlie oil as it was 

 received had the consistency of heavy tar; it would scarcely How at 

 ordinary temperatures. 



Its specific gravity at 20° was found to be 0.9845. It contained 0.84 

 per cent sulphur and 1.25 per cent nitrogen. A combustion gave 8G.32 

 per cent carbon, and 11.70 per cent hydrogen, showing that the crude 

 oil is composed, at least to a large extent, of hydrocarbons poorer in 

 hydrogen than petroleum from most other sources. In attempting to as- 

 certain the composition of this petroleum, 2000 grams were fractioned 

 under a tension of 60 mm., collecting within 5°. The first distillate 

 came over at 200° atmospheric pressure, and only small amounts were 

 collected below 175°, 60 mm. The distillation was carried to 365°, with- 

 out attempting to collect closer than in 5° fractions, since the principal 

 object was to ascertain the form of the hydrocarbons, although, as will 

 appear, the fractions gave fairly close values for their molecular weights. 



The heavy character of the constituents of this petroleum is shown by 

 the specific gravity of several distillates after the fifth distillation. 



150 -'-ISo^ 305-^-310=' 325- -330= 2i0^-245^ 



0.8649 0.9641 0.9739 0.9778 



The residue at 365° from 2000 grams was 200 grams, which showed 

 that the greater portion of the oil distilled between 150° and 360°, or 

 within a range of about 200'. Only 85 grams came over below 150°, 

 60 mm. ; at higher temperatures the fractions collected in larger amounts 

 at certain points, and these distillates were selected to ascertain the 

 series of hydrocarbons : 



155"-160^ 175^-180'' 195°-200^ 2103-215=> 



Weights, 25 70 50 75 



223^-230^ 2o0=-255^ 310=-315=' 340°^34o' 



Weights, 75 50 80 45 



* Am. Chem. Journ., 18, 1 (1896). 



t Mr. Zoul selected this work as the subject of a tliesis for the degree of Bacfi- 

 elor of Science. 



