roper manner of judging with regard
to a theory of the earth, how far it is conform to the general system of
nature, which has for object a world.

If it should be admitted, that this earth had been formed by the
collection of materials deposited within the sea, there will then appear
to be certain things which ought to be explained by a theory, before
that theory be received as belonging to this earth. These are as
follows:

_First_, We ought to show how it came about that this whole earth, or by
far the greatest part in all the quarters of the globe, had been formed
of transported materials collected together in the sea. It must be here
remembered, that the highest of our mountainous countries are equally
formed of those travelled materials as are the lowest of our plains; we
are not therefore to have recourse to any thing that we see at present
for the origin of those materials which actually compose the earth;
and we must show from whence had come those travelled materials,
manufactured by water, which were employed in composing the highest
places of our land.

_Secondly_, We must explain how those loose and incoherent materials had
been consolidated, as we find they are at present. We are not here to
allow ourselves the liberty, which naturalists have assumed without
the least foundation, of explaining every thing of this sort by
_infiltration_, a term in this case expressing nothing but our
ignorance.

_Thirdly_, The strata are not always equally consolidated. We often find
contiguous strata in very different states with respect to solidity; and
sometimes the most solid masses are found involved in the most
porous substance. Some explanation surely would be expected for this
appearance, which is of a nature so conclusive as ought to attract the
attention of a theorist.

_Fourthly_, It is not sufficient to show how the earth in general had
been consolidated; we must also explain, how it comes to pass that the
consolidated bodies are always broken and intersected by veins and
fissures. In this case, the reason commonly given, that the earth
exposed to the atmosphere had shrunk like moist clay, or contracted
by the operation of drying, can only show that such naturalists have
thought but little upon the subject. The effect in no shape or degree
corresponds to that cause; and veins and fissures, in the solid bodies,
are no less frequent under the level of the sea, than on the summits of
our mountains.

_Fifth