caput mortuum or perfect coaly state. The change from a bituminous
to a coaly substance can only take place in proportion as the
distillation of the volatile parts is permitted. Now this distillation
must be permitted, if any passage can be procured from the inflammable
body submitted to the operation of subterraneous heat; and, one stratum
of coal may find vent for the passage of those vapours, through some
crevice which is not open to another. In this way, doubtless, some of
those bodies have been inspissated or reduced to a fixed coal, while
others, at a little distance, have retained most of their volatile
parts.

We cannot doubt of this distilling operation in the mineral regions,
when we consider that in most places of the earth we find the evident
effects of such distillation of oily substances in the naphta and
petroleum that are constantly emitted along with water in certain
springs. These oily substances are no other than such as may be
procured, in a similar manner, from the fusible or inflammable coal
strata; we have therefore every proof of this mineral operation that the
nature of things admit of. We have also sufficient evidence that those
fusible and inflammable coals, which have not been distilled to a caput
mortuum, had been subjected to the operation of subterraneous heat,
because we find those fusible coals subject to be injected with pyrites,
as well as the more perfect coal.

If we now consider those various appearances of mineral bodies which
are thus explained by the theory of mineral fire, or exertion of
subterraneous heat, appearances which it is impossible to reconcile by
any supposition of aqueous solution, or that unintelligible language
of mineral infiltration which has of late prevailed, we shall be fully
satisfied, that there is a uniform system in nature of providing a power
in the mineral regions, for consolidating the loose materials deposited
at the bottom of the sea, and for erecting those masses of mineralized
substances into the place of land; we shall thus be led to admire the
wisdom of nature, providing for the continuation of this living world,
and employing those very means by which, in a more partial view of
things, this beautiful structure of an inhabited earth seems to be
necessarily going into destruction.

END OF VOLUME FIRST.

***END OF THE PROJECT GUTENBERG EBOOK THEORY OF THE EARTH, VOLUME 1 (OF
4)***

******* This file should be named 12861.txt or 12861.