240 The American Geologist. ' Apru. i9 05 
of mollusks. Moreover, there would be ample time for the 
annual growth of vegetation which would prevent the wind 
from seriously modifying the deposit. The analogy be- 
tween such conditions and those which must have pre- 
vailed in the vicinity of Carrollton, situated on the margin 
of the loess east of the Yazoo delta, was very striking and 
suggestive. 
CHEMISTRY OF CALIFORNIA PETROLEUM.* 
Paul W. Prutzman. 
The chemistry of the petroleums produced in Cali- 
fornia is involved in considerable obscurity. Investiga- 
tions of this character are so difficult and tedious, and the 
rewards so doubtful, in a practical way, that very little re- 
search along these lines has been attempted, and it is prob- 
able that no single sample of Pacific coast petroleum has 
ever been resolved into its proximate constituents. But 
though detailed information is lacking, some facts of a 
general nature may be brought forward, and these points, 
scattering as they may be, will yet throw some light on 
the ultimate nature of the oils with which we have to deal. 
Hydrocarbons. — It is very evident, from a good many 
■considerations, that the hydrocarbons making up the body 
■of California petroleum are radically dilTerent from those 
of the oils of the eastern states. The low flash point and 
boiling point in relation to the specific gravity, the prac- 
tical or entire absence of solid parafBns, the presence of 
asphalt in most of our oils, and its ready formation on heat- 
ing oils from which it has been removed, or in which it was 
originally absent, the rapid fall in viscosity of the heavier 
oils with rising temperature, and the strong tendency of 
most of our oils to oxidation, all point to the probability 
that the composition of our oil is quite distinct from that 
of Eastern petroleum. 
The petroleum of the eastern states is known to consist 
almost entirely of paraffins in the lighter members, and of 
* From Bulletin No. 32, of the California State Mining Bureau, March 
1904. . ., . 
