,
let us, for the fuller elucidation of this truth in relation to the
inorganic world, consider what would be the consequences of some
extensive cosmical revolution--say the subsidence of Central America.

The immediate results of the disturbance would themselves be
sufficiently complex. Besides the numberless dislocations of strata, the
ejections of igneous matter, the propagation of earthquake vibrations
thousands of miles around, the loud explosions, and the escape of gases;
there would be the rush of the Atlantic and Pacific Oceans to supply the
vacant space, the subsequent recoil of enormous waves, which would
traverse both these oceans and produce myriads of changes along their
shores, the corresponding atmospheric waves complicated by the currents
surrounding each volcanic vent, and the electrical discharges with which
such disturbances are accompanied. But these temporary effects would be
insignificant compared with the permanent ones. The complex currents of
the Atlantic and Pacific would be altered in direction and amount. The
distribution of heat achieved by these ocean currents would be different
from what it is. The arrangement of the isothermal lines, not even on
the neighbouring continents, but even throughout Europe, would be
changed. The tides would flow differently from what they do now. There
would be more or less modification of the winds in their periods,
strengths, directions, qualities. Rain would fall scarcely anywhere at
the same times and in the same quantities as at present. In short, the
meteorological conditions thousands of miles off, on all sides, would be
more or less revolutionised.

Thus, without taking into account the infinitude of modifications which
these changes of climate would produce upon the flora and fauna, both of
land and sea, the reader will see the immense heterogeneity of the
results wrought out by one force, when that force expends itself upon a
previously complicated area; and he will readily draw the corollary that
from the beginning the complication has advanced at an increasing rate.

Before going on to show how organic progress also depends upon the
universal law that every force produces more than one change, we have
to notice the manifestation of this law in yet another species of
inorganic progress--namely, chemical. The same general causes that have
wrought out the heterogeneity of the Earth, physically considered, have
simultaneously wrought out its chemical