same kind that you saw in a quarry at Low-wood Inn; and
it may be that both belonged to the same stratum or body of strata; for
the direction of the strata, as nearly as I could observe, was from S.W.
to N.E.; and this also is nearly the bearing of Low-wood from the place
where we now were. I send you a specimen, which you can compare with
those you brought from the lime quarry at Low-wood."

I have examined this specimen, and find it to be the common schistus
of that country, only containing many bivalve shells and fragments of
entrochi and madrapore bodies, and mixed with pyrites.

I have already observed that one single example of a shell, or of its
print, in a schistus, or in a stone stratified among those vertical or
erected masses, suffices to prove the origin of those bodies to have
been, what I had maintained them to be, water formed strata erected from
the bottom of the sea, like every other consolidated stratum of the
earth. But now, I think, I may affirm, that there is not, or rarely, any
considerable extent of country of that primary kind, in which some mark
of this origin will not be found, upon careful examination; and now I
will give my reason for this assertion. I have been examining the south
alpine country of Scotland, occasionally, for more than forty years
back, and I never could find any mark of an organised body in the
schistus of those mountains. It is true that I know of only one place
where limestone is found among the strata; this is upon Tweed-side near
the Crook. This quarry I had carefully examined long ago, but could find
no mark of any organised body in it. I suppose they now are working some
other of the vertical strata near those which I had examined; for, in
the summer 1792, I received a letter from Sir James Hall, which I shall
now transcribe. It is dated at Moffat, June 2. 1792.

"As I was riding yesterday between Noble-house and Crook, on the road to
this place, I fell in with a quarry of alpine limestone; it consists of
four or five strata, about three feet thick, one of them single, and the
rest contiguous; they all stand between the strata of slate and schist
that are at the place nearly vertical. In the neighbourhood, a slate
quarry is worked of a pure blue slate; several of the strata of slate
near the limestone are filled with fragments of limestone scattered
about like the fragments of schist in the sandstone in the neighbourhood
of the junction on our coast.[22]

[Note 22