a 
40 MABERY—THE COMPOSITION OF PETROLEUM.  [April3, 
all petroleum contains nitrogen and sulphur, although the propor- 
tion of nitrogen in Pennsylvania and Ohio crude oils is much 
smaller than that in California oil, and that the percentage of 
sulphur is much smaller in the Pennsylvania sandstone oils—only a 
trace as compared with the larger amounts in Trenton limestone, 
Corniferous limestone, in California and Texas oils. With this 
definition the distinction drawn, at least in commercial circles, 
between paraffine and asphaltic oils disappears, for Pennsylvania 
crude oil contains the asphaltic hydrocarbons, although I cannot 
assert that California oil contains paraffine. I have crystalline 
hydrocarbons separated from California oil, but their identity is 
not yet fully established. The refiner is more definite in his classi- 
fication; he knows from experience that the best yield of gaso- 
line is from Pennsylvania oil, and none from California oil. He 
is fully aware that it is useless to expect to obtain a respectable 
yield of burning oil from California or Texas petroleum, and that 
he cannot hope to obtain paraffine from those heavy oils. But 
his very heavy lubricating oils and heavy pitches and asphalts he 
knows can come only from the heavier petroleums. 
With reference to a nomenclature of the petroleum series and 
hydrocarbons, no system can safely be adopted until the structure of 
these bodies is better understood. The aromatic hydrocarbons 
benzol and its homologues are present in all petroleum so far as 
examined, but in widely variable proportions. Pennsylvania crude 
oil contains the lower members in small amounts, but not the higher 
homologues. It is true that anthracene and its congeners have 
been described as separated from petroleum residues, but it is prob- 
able that such bodies are not present in the original oil; they are 
doubtless formed by decomposition during distillation. California 
petroleum contains much larger proportions of the aromatic hydro- 
carbons, especially of the xylols and others with higher boiling 
points. In one of our distillates from California crude oil so much : 
naphthaline was present that the distillate became solid on slight 
cooling. This distillate came over at about 215°. The only other 
instance in which naphthaline has been found in petroleum was 
its separation by Warren and Storer from Rangoon petroleum. 
The terminology of the series C,H.,4. has been well defined, 
and the names adopted by Kraft for the members with high boiling 
points, liquids and solids, which he separated from shale distillates 
are applicable to the corresponding bodies in Pennsylvania crude 
