f the river, which
is above the place of the pudding-stone and vertical strata. Neither are
these last discoverable below the town of Jedburgh, at least so far as
I have seen; and the line of division, or plane of junction of the
vertical and horizontal strata, appears to decline more than the bed of
the river.

But it may be asked, how the horizontal strata above, among which are
many very strong beds, have been consolidated. The answer to this
question is plain. Those strata have been indurated or consolidated
in no other manner than the general strata of the earth; these being
actually the common strata of the globe; while the vertical or schistus
strata are the ordinary strata still farther manufactured, (if we may be
allowed the expression) in the vicissitude of things, and by the mineral
operations of the globe. That those operations have been performed by
subterraneous heat has been already proved; but I would now mention some
particular appearances which are common or general to those strata, and
which can only be explained upon that principle.

The red marly earth is prevalent among those strata; and it is with this
red ferruginous substance that many of the sand-stone strata are tinged.
It is plain that there had been an uniform, deposits of that sand and
tinging earth; and that, however different matter might be successively
deposited, yet that each individual stratum should be nearly of the same
colour or appearance, so far as it had been formed uniformly of the same
subsiding matter. But, in the most uniform strata of red sand-stone,
the fracture of the stone presents us with circular spots of a white or
bluish colour; those little spheres are in all respects the same with
the rest of the stone, they only want the tinging matter; and now it may
be inquired how this has come about.

To say that sphericles of white sand should have been formed by
subsiding along with the red sand and earth which composed the uniform
stratum whether of sand-stone or marl, (for it happens equally in both,)
is plainly impossible, according to our notion of that operation in
which there is nothing mysterious. Those foliated strata, which are of
the most uniform nature, must have been gradually accumulated from the
subsiding sand and earth; and the white or colourless places must have
had their colour destroyed in the subsequent cementing operations. It
is often apparent, that the discharging operation had proceeded from a
cent