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plants and trees ; and such we well know is the appearance which 
is yielded by peat in certain periods of its formation. This mass, 
then, of decayed leaves and roots of plants, and of trees, as described 
by the ingenious observer, was undoubtedly a mass of long buried 
vegetable matter, part of a stratum of peat, passing through the bitu- 
minous fermentation ; and which had become covered with water. 
The opportunity of its separation had doubtless been given, by the 
superincumbent strata having been so reduced by the excavation 
which formed the lake, as not to leave a sufficient thickness and 
strength to resist the expansive powers of the gaseous matters ; and 
these, by their extrication, had separated the mass, which, from its 
lightness, floated on the water. 
That this bituminous fermentation was actually going on may be 
reasonably inferred, from the nature of the gas which was expelled ; 
its peculiar odour, and its imputed inflammability, strongly denoting 
the presence of hydrogen; the separation, and the subsequent 
fixation of which have been assumed as important steps in this 
process. Another circumstance yields very strong collateral evidence, 
that this operation had proceeded to a certain length. The specific 
gravity of all bituminous substances is, generally, less than that of 
the vegetable matter from which they have been formed ; this is most 
certainly the case, when wood has suffered this species of conversion. 
As this process has therefore gone on, the substance has become 
specifically lighter, and cavities have been formed by, and distended 
with, the detached hydrogen, which must have also increased the 
levity of the mass, and enabled it, even with the superincumbent 
earth, to make its ascent through the water. 
It may also be remarked, that the eruption of these gaseous 
matters in considerable quantities is sufficient to account for the 
agitation of the waters, and for the other phenomena which are 
described as appearing to have been produced by some powerful 
elevating force, applied beneath. 
