sometimes
inclining to red; and is full of small, black specks. Quartz seems to
have a more than usual share in its composition, and we occasionally
found crystals of that substance upon the shores. The black specks were
thought to be grains of tin, and to have communicated a deleterious
quality to the water used by the shipwrecked people. The exceptions to
the general prevalence of granite were few: they consisted of some black,
and some grey slate, in thin _strata_, placed nearly perpendicular to the
horizon; but even here, the granite had pervaded the fissures of the
_strata_; and, in two instances, a substance which, from its appearance,
I supposed to be a toad stone, had insinuated itself.

Some of the trees on Preservation Island had partly undergone a peculiar
transformation. The largest of them were not thicker than a man's leg,
and the whole were decayed; but whilst the upper branches continued to be
of wood, the roots at the surface, and the trunks up to a certain height,
were of a stony substance resembling chalk. On breaking these chalky
trunks, which was easily done, rings of the brown wood sometimes appeared
in them, as if imperfectly converted; but in the greater number, nothing
more than circular traces remained. The situation in which these trees
were principally found, is a sandy valley near the middle of the island,
which was likewise remarkable for the quantity of bones of birds and
small quadrupeds, with which it was strewed. The petrefactions were
afterwards more particularly examined by Mr. Bass, who adopted the
opinion that they had been caused by water.

Upon Cape-Barren Island the hills rise to a considerable height, that of
the peak, which does not much exceed some others, being near twelve
hundred feet; but on the smaller islands there is no elevation of
importance. The upper parts of all are generally crowned with huge lumps
of granite; and upon many of these, particularly on Rum Island, is a
smaller, unconnected, round lump, which rests in a hollow at the top, as
a cup in its saucer; and I observed with a glass, that there was a stone
of this kind at the summit of the peak of Cape Barren. The lower parts of
the islands are commonly sandy; and, in several places under the hills,
swamps and pools are formed. The water in these is generally tinged red;
and in one, situate between Passage and Cone Points, it had so much the
appearance of blood, that I went to taste it; but, except being a littl