ill giving
and reflecting light, and performing their movements as of old. Some
imagined that the strata, so rich in organic remains, instead of being
due to secondary agents, had been so created in the beginning of things
by the fiat of the Almighty. Others, as we have seen, ascribed the
imbedded fossil bodies to some plastic power which resided in the earth
in the early ages of the world. In what manner were these dogmas at
length exploded? The fossil relics were carefully compared with their
living analogues, and all doubts as to their organic origin were
eventually dispelled. So, also, in regard to the nature of the
containing beds of mud, sand, and limestone: those parts of the bottom
of the sea were examined where shells are now becoming annually entombed
in new deposits. Donati explored the bed of the Adriatic, and found the
closest resemblance between the strata there forming, and those which
constituted hills above a thousand feet high in various parts of the
Italian peninsula. He ascertained by dredging that living testacea were
there grouped together in precisely the same manner as were their fossil
analogues in the inland strata; and while some of the recent shells of
the Adriatic were becoming incrusted with calcareous rock, he observed
that others had been newly buried in sand and clay, precisely as fossil
shells occur in the Subapennine hills. This discovery of the identity of
modern and ancient submarine operations was not made without the aid of
artificial instruments, which, like the telescope, brought phenomena
into view not otherwise within the sphere of human observation.

In like manner, the volcanic rocks of the Vicentin had been studied in
the beginning of the last century; but no geologist suspected, before
the time of Arduino, that these were composed of ancient submarine
lavas. During many years of controversy, the popular opinion inclined to
a belief that basalt and rocks of the same class had been precipitated
from a chaotic fluid, or an ocean which rose at successive periods over
the continents, charged with the component elements of the rocks in
question. Few will now dispute that it would have been difficult to
invent a theory more distant from the truth; yet we must cease to wonder
that it gained so many proselytes, when we remember that its claims to
probability arose partly from the very circumstance of its confirming
the assumed want of analogy between geological causes and those now i