a peat-moss near Lochbroom, in
Ross-shire, where, in less than half a century after the fall of the
trees, the inhabitants dug peat.[1008] Dr. Walker mentions a similar
change, when, in the year 1756, the whole wood of Drumlaurig in
Dumfries-shire was overset by the wind. Such events explain the
occurrence, both in Britain and on the Continent, of mosses where the
trees are all broken within two or three feet of the original surface,
and where their trunks all lie in the same direction.[1009]

It may however be suggested in these cases, that the soil had become
exhausted for trees, and that, on the principle of that natural rotation
which prevails in the vegetable world, one set of plants died out and
another succeeded. It is certainly a remarkable fact that in the Danish
islands, and in Jutland and Holstein, fir wood of various species,
especially Scotch fir, is found at the bottom of the peat-mosses,
although it is well ascertained that for the last five centuries no
Coniferae have grown wild in these countries; the coniferous trees which
now flourish there having been all planted towards the close of the last
century.

Nothing is more common than the occurrence of buried trees at the bottom
of the Irish peat-mosses, as also in most of those of England, France,
and Holland; and they have been so often observed with parts of their
trunks standing erect, and with their roots fixed to the subsoil, that
no doubt can be entertained of their having generally grown on the spot.
They consist, for the most part, of the fir, the oak, and the birch:
where the subsoil is clay, the remains of oak are the most abundant;
where sand is the substratum, fir prevails. In the marsh of Curragh, in
the Isle of Man, vast trees are discovered standing firm on their
roots, though at the depth of eighteen or twenty feet below the surface.
Some naturalists have desired to refer the imbedding of timber in
peat-mosses to aqueous transportation, since rivers are well known to
float wood into lakes; but the facts above mentioned show that, in
numerous instances, such an hypothesis is inadmissible. It has,
moreover, been observed, that in Scotland, as also in many parts of the
Continent, the largest trees are found in those peat-mosses which lie in
the least elevated regions, and that the trees are proportionally
smaller in those which lie at higher levels; from which fact De Luc and
Walker have both inferred that the trees grew on the spot, for th