it has been rent again, and a newer melted
matter of the same character sent through the opening. Finally, in
the crust as thus arranged, there are, in many places, chinks
containing veins of metal. Thus, there is first a great inferior
mass, composed of crystalline rock, and probably resting
immediately on the fused and expanded matter of the interior: next,
layers or strata of aqueous origin; next, irregular masses of
melted inferior rock that have been sent up volcanically and
confusedly at various times amongst the aqueous rocks, breaking up
these into masses, and tossing them out of their original levels."

This, we believe, is a correct outline of the crust of the earth, so far
as it has been possible to observe it. It exhibits extraordinary signs
of commotion and vicissitude; the lowest rocks indicating a previous
condition of igneous fusion; those above them of aqueous solution. Fire
and water have thus been the chief tellurian anarchists, and the shaking
of continents and the constant shifting of level in sea and land still
continue to attest their restless energies. That igneous matter has,
during many periods, been protruded from below--that mountains have
risen in succession from the sea, and injected their molten substance
through cracks and fissures of superincumbent strata--are facts resting
on indubitable evidence. Many masses of granite became the solid bottom
of some portions of the sea before the secondary strata were laid
gradually upon them. The granite of Mont Blanc rose during a recent
tertiary period. "We can prove," says Professor SEDGWICK, "more than
mere shiftings of level, and that many portions of sea and land have
entirely changed their places. The rocks at the top of Snowdon are full
of petrified sea-shells; the same may be said of some high crests of the
Alps, Pyrenees, and Andes. We have proof demonstrative that many parts
of Scotland, and that all England, formed, during many ages, the solid
bottom of the sea. It may be true that the antagonist powers of nature
during the human period have reached a kind of balance. But during all
geological periods there have been such long intervals of repose, or of
such gradual movements, that we may trace the history of the earth in
the successive deposits formed in the waters of the sea." This is the
great business of geology.

Although at first sight the interior of the earth appears a confused
scene,