onry, that run transversely, from side to side, still to fill up.
Along one of these ditch-like gaps, which serves to insulate the eastern
and highest portion of the Scuir from all its other portions, we find
fragments of a rude wall of uncemented stones, the remains of an
ancient hill-fort; which, with its natural rampart of rock on three of
its four sides, more than a hundred yards in sheer descent, and with its
deep ditch and rude wall on the fourth, must have formed one of the most
inaccessible in the kingdom. The masses of pitchstone a-top, though so
intensely black within, are weathered on the surface into almost a pure
white; and we found lying detached among them, fragments of common
amygdaloid and basalt, and minute slaty pieces of chalcedony that had
formed apparently in fissures of the trap. We would have scrutinized
more narrowly at the time had we expected to find anything more rare;
but I did not know until full four months after, that aught more rare
was to be found. Had we examined somewhat more carefully, we might
possibly have done what Mr. Woronzow Greig did on the Scuir about
eighteen years previous,--picked up on it a piece of _bona fide_ Scotch
pumice. This gentleman, well known through his exertions in statistical
science, and for his love of science in general, and whose tastes and
acquirements are not unworthy the son of Mrs. Somerville, has kindly
informed me by letter regarding his curious discovery. "I visited the
island of Eigg," he says, "in 1825 or 1826, for the purpose of shooting,
and remained in it several days; and as there was a great scarcity of
game, I amused myself in my wanderings by looking about for natural
curiosities. I knew little about Geology at the time, but, collecting
whatever struck my eye as uncommon, I picked up from the sides of the
Scuir, among various other things, a bit of fossil wood, and, nearly at
the summit of the eminence, a piece of pumice of a deep brownish-black
color, and very porous, the pores being large and round, and the
substance which divided them of a uniform thickness. This last specimen
I gave to Mr. Lyell, who said that it could not originally have belonged
to Eigg, though it might possibly have been washed there by the sea,--a
suggestion, however, with which its place on the top of the Scuir seems
ill to accord. I may add, that I have since procured a larger specimen
from the same place." This seems a curious fact, when we take into
account the i