E. B. Andrews on Petroleum in its Geological Relations. 41 
of Ohio which I have undertaken, and from which I hope 
o derive important results relative to the origin of bitumen, 
aes animal and vegetable, the depth under water or beneath 
sediments at which the process of ering wren pare ae 
the diffusion of the bitumen in certain sedim and no 
others,—I think I have already found fasts en cag to siti 
that the bitumen now disseminated through pte shales, &c., 
must once have been in a condition of fluidity somewhat akin 
to that of petroleum. 
Mr. Hunt, p. 522, speaks of the oil-producing corals of Bertie 
as being “surroun nded y solid crystalline encrinal limestone 
which is free from oil,” and of the “light-colored limestones 
b 
well or excavation. we not ask lish if the sur- 
soundings of this petroleum had Saisie been different, that 
is, had there been proper sediments with suitable submergen ce 
and pressure, would not the petroleum have been absorbed and 
helped to constitute bituminous strata? But can we follow this 
ea Ae the nature of its porate from ab- 
, and that subsequently more or less of this peti bins 
ascended from its places of birth to accum alate in such r - 
If such were the origin and history of all our petroleum it would 
be reasonable to suppose that much of it would still be found 
tn situ, i. e., where it meshes but instead of this, all the oil I 
ave ever seen, except very insignificant quantities in isolated 
cavities in fossiliferous limestones, has “Aiea strayed far from 
its place of origin. It is seldom, indeed, that we nd any oil 
in juxtaposition with bituminous strata of : any rena: It is more 
often found in fissures in sand-rocks, rocks in which no oil could 
ever have been generated, for whatever organic matter they 
not fab impossible that the oil could have originated in these 
sand-rocks, or in the arenaceous shales which underlie them in 
western Pennsylvania, but is most probable that the oil ascended 
from the still lower rocks in the form of vapor which condensed 
in the superior cavities. In other words, the oil which, accord- 
‘ing to the theory, was formed far below in the original bitumin- 
process of 
ization of tein sui matter, must have undergone a 
nies 
ve dactaeaiad Series, Vou. XLII, No. 124.—Juny, 1866. 
6 ” 
