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
revolutionized. Thus, without taking into account the infinitude of
modifications which these changes would produce upon the flora and
fauna, both of land and sea, the reader will perceive the immense
heterogeneity of the results wrought out by one force, when that force
expends itself upon a previously complicated area; and he will 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 on the 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 heterogeneity. There is every
reason to believe that at an extreme heat the elements cannot combine.
Even under such heat as can be artificially produced, some very strong
affinities yield, as, for instance, that of oxygen for hydrogen; and the
great majority of chemical compounds are decomposed at much lower
temperatures. But without insisting on the highly probable inference,
that when the Earth was in its first state of incandescence there were
no chemical combinations at all, it will suffice for our purpose to
point to the unquestionable fact that the compounds which can exist at
the highest temperatures, and which must, therefore, have been the first
that were formed as the Earth cooled, are those of the simplest
constitutions. The protoxides--including under that head the alkalies,
earths, &c.--are, as a class, the most stable compounds we know: most of
them resisting decomposition by any heat we can generate. These are
combinations of the simplest order--are but one degree less homogeneous
than the elements themselves. More heterogeneous, less stable, and
therefore later in the Earth's history, are the deutoxides, tritoxides,
peroxides, &c.; in which two, three, four, or more atoms of oxygen are
united with one atom of metal or other element. Higher than these in
heterogeneity are the hydrates; in which an oxide of hydrogen, united
with an oxide of some other element, forms a substance whose atoms
severally contain at least four ultimat