unds a
pith that has been replaced by a stony mould. The fragile ligneous
cylinder would certainly have been broken during such transportation.

The carbonized specimens were never fluid or pasty, since there are some
that have left their impressions with the finest details in the schists
and sandstones, but none of the latter that has left its traces upon the
coal. The surface of the isolated specimens is well defined, and their
separation from the gangue (which has never been penetrated) is of the
easiest character.

The facts just pointed out are entirely contrary to the theory of the
formation of coal by way of eruption of bitumen.

(2) The place occupied by peats, lignites, and bituminous and anthracite
coal in sedimentary grounds, and the organic structure that we find less
and less distinct in measure as we pass from one of these combustibles to
one more ancient, have given rise to the theory mentioned above, viz.,
that vegetable matter having, under the prolonged action of heat and
moisture, experienced a greater and greater alteration, passed
successively through the different states whose composition is indicated
in the following table:

H. C. O. N. Coke. Ashes. Density.
Peat 5.63 57.03 29.67 2.09 ---- 5.58 ----
Lignite 5.59 70.49 17.2 1.73 49.1 4.99 1.2
Bitumin. coal 5.14 87.45 4 1.63 68 1.78 1.29
Anthracite 3.3 92.5 2.53 ---- 89.5 1.58 1.3

Aside from the fact that anthracite is not met with solely in the lower
coal measures, but is found in the middle and upper ones, and that
bituminous coal itself is met with quite abundantly in the secondary
formations, and even in tertiary ones, it seems to result from recent
observations that if vegetable matter, when once converted into lignites,
coal, etc., be preserved against the action of air and mineral waters by
sufficient thick and impermeable strata of earth, preserves the chemical
composition that it possessed before burial. The coal measures of
Commentry, as well as certain others, such as those of Bezenet, Swansea,
etc., contain quite a large quantity of coal gravel in sandstone or
argillaceous rocks. These fragments sometimes exhibit a fracture analogous
to that of ordinary coal, with sharp angles that show that they have not
been rolled; and the sandstone has taken their exact details, which are
found in hollow form in the gangue. In other cases thes