Volume 3 - Electric Scotland

120 PEAT.
is received at the side. In a similar manner may a
maritime inlet be converted into a fresh-water lake ; as
I have pointed out in preceding parts of these letters.
Under varying circumstances, that land may be a meadow
instead of a peat moss. Thus, among many other
modes, does nature contract the range of her aquatic
creation to extend that of her terrestrial one. Hence
also it is that beds of marl are so often found beneath
peat. These are the remains of the shell fish that once
inhabited the water; and thus, where they are found,
we may be sure that the peat bog was once the seat of a
lake. The same considerations may often lead to the
valuable discovery of marl where it was not suspected.
Wherever a flat peat moss is included in a basin and
gives passage to a river, it may be presumed that it was
formerly a lake ; and, on digging, marl beds will often
be found beneath it, or interstratified with the peat, and
occasionally with gravel. This is a valuable pieceofknow-
ledge to agriculturists, though it has been entirely over-
looked by the voluminous and endless writers who have
gone on to this day puzzling this very simple subject.
The formation of Maritime peat is analogous to that of
lake peat; and the effects are also analogous; the result
of the shoaling being, first a salt marsh, and lastly a
meadow. The foundation is often laid by the Zostera, some-
times by the common sea weeds ;
and the process is con-
tinued by the semi-maritime inhabitants of salt marshes,
till the land is finally raised beyond the reach of the sea,
so as to become a meadow. I know of no place where the
whole process through all its stages can be more easily
traced than in the Firth of Forth above Culross : it is also
visible in Loch Tarbet ; and, at some future day, Barra
and Vatersa will thus become united. In Holland, from
the peculiarity of its situation, the common submarine