1903.] MABERY—THE COMPOSITION OF PETROLEUM. 43 
As I shall presently explain, Ohio crude oil contains a much 
smaller proportion of the series C,H,, 4., and it cannot be expected 
to yield burning oil of as good quality as Pennsylvania crude oil. 
Canadian burning oil should be still poorer in quality, which is 
easily seen by the consumer who will pay a high duty on United 
States oil rather than use his own product. 
PENNSYLVANIA PETROLEUM. 
As mentioned above, Pennsylvania crude oil contains minute 
amounts of sulphur and nitrogen compounds, and a small propor- 
tion of benzol derivatives ; but the great bulk of the oil is com- 
posed of the series C,H,, 42, beginning with the butanes and end- 
ing with solid hydrocarbons of such high molecular weights that 
they cannot be determined by any method now known. We have 
reached the hydrocarbon C,,H,., and it is the last one of the series 
whose molecular weight could be determined. It is quite proba- 
ble that there are as many as eight or even more of the hydro- 
carbons with greater molecular weight. 
It has been an open question with practical oil men, and per- 
haps is still with some, as to whether solid paraffine is contained in 
crude petroleum or whether it is formed in the process of distilla- 
tion. In the ordinary process of refining crude oil, a very consid- 
erable proportion of the hydrocarbons is lost in the last stages of 
the destructive distillation which ends with a large mass of coke. 
On comparing the thin liquid crude oil with products obtained 
from it in refining, it would be natural for the superficial observer 
to reason, from the appearance of coke at the end of the distillation 
and other heavy products, that solid paraffine should be formed in 
a similar way by decomposition of the light liquid crude oil. 
But careful consideration of the nature and origin of petroleum 
precludes the possibility of its formation by distillation. It is true 
that paraffine was first obtained by Reichenbach by the distillation 
of vegetable and animal organic matter, and there is no question 
that it has been formed ina similar manner by natural processes. 
But petroleum must be regarded as a final product of decomposi- 
tion, and while the series may be changed from one to another to a 
limited extent, decomposition of the constituents leads to the 
formation of simpler products until finally carbon is reached. 
Therefore, instead of paraffine as a result of decomposition of other 
