at vegetable substance which
forms combustible turf, called peat. Now, this moss water leaves, upon
evaporation, a bituminous substance, which very much resembles fossil
coal. Therefore, in order to employ this vegetable infusion, delivered
into the ocean for the purpose of forming bituminous strata at its
bottom, it is only required to make this bituminous matter separate and
subside.

If now we consider the immense quantity of inflammable vegetable
substance, dissolved in water, that is carried into the sea by all the
rivers of the earth, and the indefinite space of time during which those
rivers have been pouring in that oily matter into the sea; and if we
consider, that the continual action of the sun and atmosphere upon this
oily substance tends, by inspissation, to make it more and more dense or
bituminous, we cannot hesitate in supposing a continual separation
of this bituminous matter or inspissated oil from the water, and
a precipitation of it to the bottom of the sea. This argument is
corroborated by considering, that, if it were otherwise, the water of
the sea must have, during the immense time that rivers are proved
to have run, be strongly impregnated with that oily or bituminous
substance; but this does not appear; therefore we are to conclude, that
there must be the means of separating that substance from the water in
which it had been dissolved.

If there is thus, from the continual perishing of animal and vegetable
bodies upon the surface of this earth and in the sea, a certain supply
of oily or bituminous matter given to the ocean, then, however small a
portion of this shall be supposed the whole oily or inflammable matter
produced upon the surface of the earth, or however long time it may
require for thus producing a stratum or considerable body of coal,
we must still see in this a source of the materials proper for the
production of that species of strata in the bottom of the sea.

We have now considered the proper materials of which pure fossil coal
is chiefly formed; we have at present to consider what should be the
appearances of such a substance as this collected at the bottom of the
sea, and condensed or consolidated by compression and by heat. We should
thus have a body of a most uniform structure, black, breaking with a
polished surface, and more or less fusible in the fire, or burning with
more or less smoke and flame, in proportion as it should be distilled
or inspissated, less or more, b