fusion, they assume a new and more crystalline form, no longer
exhibiting that stratified disposition and those curious impressions and
fantastic markings, by which they were previously characterized. This
process cannot have been carried on for an indefinite time, for in that
case all the stratified rocks would long ere this have been fused and
crystallized. It is therefore probable that the whole planet once
consisted of these mysterious and curiously bedded formations at a time
when the volcanic fire had not yet been brought into activity. Since
that period there seems to have been a gradual development of heat; and
this augmentation we may expect to continue till the whole globe shall
be in a state of fluidity and incandescence."

Such might be the system of the Gnome at the very time that the
followers of Leibnitz, reasoning on what they saw on the outer surface,
might be teaching the opposite doctrine of gradual refrigeration, and
averring that the earth had begun its career as a fiery comet, and might
be destined hereafter to become a frozen mass. The tenets of the schools
of the nether and of the upper world would be directly opposed to each
other, for both would partake of the prejudices inevitably resulting
from the continual contemplation of one class of phenomena to the
exclusion of another. Man observes the annual decomposition of
crystalline and igneous rocks, and may sometimes see their conversion
into stratified deposits; but he cannot witness the reconversion of the
sedimentary into the crystalline by subterranean fire. He is in the
habit of regarding all the sedimentary rocks as more recent than the
unstratified, for the same reason that we may suppose him to fall into
the opposite error if he saw the origin of the igneous class only.

It was not an impossible contingency, that astronomers might have been
placed at some period in a situation much resembling that in which the
geologist seems to stand at present. If the Italians, for example, in
the early part of the twelfth century, had discovered at Amalfi, instead
of the pandects of Justinian, some ancient manuscripts filled with
astronomical observations relating to a period of three thousand years,
and made by some ancient geometers who possessed optical instruments as
perfect as any in modern Europe, they would probably, on consulting
these memorials, have come to a conclusion that there had been a great
revolution in the solar and sidereal systems