ving thus stated the case of combustible or bituminous strata, I would
ask those naturalists, who adhere to the theory of infiltration and the
operation of water alone, how they are to conceive those strata formed
and consolidated. They must consider, that here are immense bodies of
those combustible strata, under hundreds, perhaps thousands, of fathoms
of sand-stone, iron-stone, argillaceous and calcareous strata. If they
are to suppose bituminous bodies collected at the bottom of the sea,
they must say from whence that bitumen had come; for, with regard to the
strata below those bituminous bodies, above them, and between them,
we see perfectly from whence had come the materials of which they are
formed. They cannot say that it is from a collection of earthy matter
which had been afterwards bituminized by infiltration; for, although
we find many of those earthy strata variously impregnated with the
bituminous and coaly matter, I have shown that the earthy and the
bituminous matter had subsided together; besides, there are many of
those coaly and bituminous strata in which there is no more than two or
three _per cent._ of earthy matter or ashes after burning; therefore
the strata must have been formed of bituminous matter, and not simply
impregnated with it.

To avoid this difficulty, we shall allow them to form their strata,
which certainly is the case in great part, by the collection of
vegetable bodies; then, I desire them to say, in what manner they are
to consolidate those bodies. If they shall allege that it is by simple
pressure, How shall we conceive the numerous veins of spar and pyrites,
which traverse those strata in all directions, to be formed in
those bodies consolidated by the compression of the superincumbent
masses?--Here is a manifest inconsistency, which proves that it could
not be. But, even were we to suppose all those difficulties to be over
come, there is still an impossibility in the way of that inconsiderate
theory, and this will appear more fully in the following chapter.

SECT. III.--The Mineralogical Operations of the Earth illustrated from
the Theory of Fossil Coal.

There is not perhaps a greater difference among the various qualities of
bodies than that which may be observed to subsist between the burning of
those two substances, that is, the inflammable bodies on the one hand,
and those that are combustible on the other. I have treated of that
distinction in Dissertations upon subject