ACCOUNT OF THE ENGLISH 148 COLONY. [ 1799*
the granite are mixed with it in various proportions. Some parts
are a mere mafs o f thefe broken pieces cemented together by the calcareous
matter ; whilft others are an almoft perfed chalk, and are
capable o f being burnt into excellent lime. Broken fea (hells and
other exuviae of marine animals are apparent throughout the whole
mafs.
Upon the beach at the foot o f this chalky rock, was found a very
confiderable quantity o f the black metallic particles which appear
in the granite as black Ihining fpecks, and are in all probability
grains of tin.
To find this fmall bed o f the remains o f fhell animals, o f which
ch a lk is formed wherever found, in fuch an unexpected fituation,
excited fome furprife; and Mr. Bafs endeavoured to inveftigate the
caufe of this depofit, by examining the form o f the neighbouring
parts of the ifland.
The refult o f his inquiries and conjectures amounted to th is:
that as traces o f the fea, and of the effects o f running waters, were
plainly difcernible in many parts of the illand, and more particularly
in the vicinity of this depofit o f chalk and granite, it feemed
highly probable that it had been formed by two ftreams o f the
tide, which, when the ifland was yet beneath the furface o f the
fea, having fwept round a large lump o f rocks, then met and formed
an eddy, where every fubftance would fall to the bottom. The
lump of rocks is now a rocky knowl, which runs tapering from
the oppofite fide o f the ifland toward the chalk.. On each fide o f it
is-a gap, through which the two ftreams appear to have palled.
The vegetation on the ifland feems brown and ftarved. It con-
fifts of a few Hunted trees ; feveral patches o f brulh, clofe fet and
almoft impenetrable; large tufts o f four and wiry grafs, and abundance
of low faltilh plants, chiefly o f the creeping kind.
A fmall fpot upon the eaft end o f the illand prefented a phenomenon
which feemed not eafily explicable by any known laws of
that clals o f natural hiftory to which it alone was referable.
Amid ft
J a n u a r y . ] OF NEW SOUTH WALES. 14 9
Amidft a patch of naked fand, upon one o f the higheft parts of
the ifland, at not lei's than 100 feet above the level o f the fea,
within the limits, of a few hundred yards fquare, were lying Mattered
about a number o f Ihort broken branches of old dead trees, of
from one to three inches in diameter, and feemingly of a kind fimi-
lar to the large brulh wood. Amid thefe broken branches were
feen (licking up feveral white Honey Humps, of fizes ranging between
the above diameters, and in height from a foot to a foot and a half.
Their peculiar form, together with a number o f prongs of their
own quality, projecting in different diredions from around their
bafe, and entering the ground in the manner of roots, prefented
themfelves to the mind o f an obferver, with a ftriking, refemblance
to the Humps and roots o f fmall trees. Thefe were extremely
brittle, the flighteft blow with a Hick, or with each other, being
fufficient to break them Ihort o ff; and when taken into the hand,
many o f them broke to pieces with their own weight.
On being broken tranfverfely, it was immediately leen that the
internal part was divided into interior or central, exterior or cortical.
The exterior part, which in different fpecimens occupied various
proportions o f the whole, refembled a fine white and foft
grit-ftone; but acids being applied, (hewed it to be combined with
a confiderable portion of calcareous matter. The interior, or central
part was always circular, but feldom found o f the fame diameter,
or of the fame compofition, on any two Humps. In fome,
the calcareous and fandy matter had taken fuch entire poffelfion,
that every fragment of the wood was completely obliterated; but
yet a faint central ring remained. In others was a center of chalk,
beautifully white,, that crumbled between the fingers to the fineft
powder ; fome confifted o f chalk and brown earth, in various quantities,
and fome others had detained a few frail portions of their
woody fibres,, the (paces, between which were filled, up with chalky
earth.
It