James Hutton (1726-1797)

70

                      HISTORY of the SOCIETY.

ced in the northern part of the island, have their sides covered
with primitive schistus of various kinds, to which, on the sea-
shore, succeed secondary strata of grit, limestone, and even coal.
Here, therefore, Dr HUTTON had another opportunity of exa-
mining the junction of the granite and schistus, and found
abundance of the veins of the former penetrating into the latter
In three different places he met with this phenomenon; in the
torrents that descend from the south side of Goatfield; in Glen-
rosa, on the west, and in the little river Sannax, on the north-
east, of that mountain. From the first of these he brought a
specimen of some hundred weight, consisting of a block of
schistus, which includes a large vein of granite.

AT the northern extremity of the island he had likewise a
view of the secondary strata lying upon the primary, with their
planes at right angles to one another. In the great quantity,
also, of pudding-stone, containing rounded quartzy gravel, uni-
ted by an arenaceous cement; in the multitude of whinstone
dikes, which abound in this island; and in the veins of pitch-
stone, a fossil which he had not before met with in its native
place; he found other interesting subjects of observation; so
that he returned from this tour highly gratified, and used often
to say that he had no where found his expectations so much ex-
ceeded, as in the grand and instructive appearances with which
nature has adorned this little island.

MR JOHN CLERK, the son of his friend Mr CLERK of Elden,
accompanied him in this excursion, and made several drawings,
which, together with a description of the island drawn up after-
wards by Dr HUTTON, still remain in manuscript.

THE least complete the observations at Arran was that
of the junction of the primitive with the secondary strata,
which is but indistinctly seen in that island, and only at
one place. Indeed, the contact of these two kinds of rock,
though it forms a line circumscribing the bases of all primitive
countries,