"It appears that the basis rock of the earth, as it may be called,
is of hard texture, and crystalline in its constitution. Of this
rock, granite may be said to be the type, though it runs into many
varieties. Over this, except in the comparatively few places where
it projects above the general level in mountains, other rocks are
disposed in sheets or strata, with the appearance of having been
deposited originally from water. But these last rocks have nowhere
been allowed to rest in their original arrangement. Uneasy
movements from below have broken them up in great inclined masses,
while in many cases there has been projected through the rents
rocky matter more or less resembling the great inferior crystalline
mass. This rocky matter must have been in a state of fusion from
heat at the time of its projection, for it is often found to have
run into and filled up lateral chinks in these rents. There are
even instances where 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