eath this, the granite which had been simply disintegrated was again
solidified, and returned in all respects to its former condition. The
temperature, however, and with it the expansive force of the inferior
zone, was continually on the increase, the caloric of the interior of
the globe still endeavoring to put itself in equilibrio by passing off
towards the less-intensely heated crust.

"This continually increasing expansive force must at length have
overcome the resistance opposed by the tenacity and weight of the
overlying consolidated strata. It is reasonable to suppose that this
result took place contemporaneously, or nearly so, on many spots,
wherever accidental circumstances in the texture or composition of the
oceanic deposits led them to yield more readily; and in this manner
were produced those original fissures in the primeval crust of the earth
through some of which (fissures of elevation) were intruded portions of
interior crystalline zones in a solid or nearly solid state, together
with more or less of the intumescent granite, in the manner
above described; while others (fissures of eruption) gave rise to
extravasations of the heated crystalline matter, in the form of
lavas--that is, still further liquefied by the greater comparative
reduction of the pressure they endured."(3)

The Neptunists stoutly contended for the aqueous origin of volcanic as
of other mountains. But the facts were with Scrope, and as time went
on it came to be admitted that not merely volcanoes, but many "trap"
formations not taking the form of craters, had been made by the
obtrusion of molten rock through fissures in overlying strata. Such,
for example, to cite familiar illustrations, are Mount Holyoke, in
Massachusetts, and the well-known formation of the Palisades along the
Hudson.

But to admit the "Plutonic" origin of such widespread formations was
practically to abandon the Neptunian hypothesis. So gradually the
Huttonian explanation of the origin of granites and other "igneous"
rocks, whether massed or in veins, came to be accepted. Most geologists
then came to think of the earth as a molten mass, on which the crust
rests as a mere film. Some, indeed, with Lyell, preferred to believe
that the molten areas exist only as lakes in a solid crust, heated to
melting, perhaps, by electrical or chemical action, as Davy suggested.
More recently a popular theory attempts to reconcile geological facts
with the claim of the physicist