Sometimes it is found in an irregular mass or mountain, as Mr Cronstedt
has properly observed; but he has also said, that this is not the case
in general. His words are: "It is oftener found in form of veins in
mountains of another kind, running commonly in a serpentine manner,
contrary or across to the direction of the rock itself."
The origin of this form, in which the trap or whin-stone appears, is
most evident to inspection, when we consider that this solid body had
been in a fluid state, and introduced, in that state, among strata,
which preserved their proper form. The strata appear to have been
broken, and the two correspondent parts of those strata are separated to
admit the flowing mass of whin-stone.
A fine example of this kind may be seen upon the south side of the
Earn, on the road to Crief. It is twenty-four yards wide, stands
perpendicular, and appears many feet above the surface of the ground. It
runs from that eastward, and would seem to be the same with that which
crosses the river Tay, in forming Campsy-lin above Stanley, as a lesser
one of the same kind does below it.
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