The Express.
London, England, 1852-07-03 00:00:00

LECTURES OX GOLD.

The second lecture of the course of six on "Gold"
now in progre'a at the Muecum of Practical Geology, in
Jermyn-street, was delivered last night. The lecturer was
Mr. &beard Forbes, VACS. The subject " Our Know-
=of Australian Rocks as derived from their organic re-
." There was an audience of about five hundred
persons—theee, as on the hut occasion, being Oh fly young
en and intending emigrants to the Awdealien gold
region. The lecture was of an elementary cburaetcr, and
eonsisted in a general statement of the leading facts of
geology, and a detailed description of the maps,
Sections, and specimens, illustrative of the physical geology
ef.Australia, displayed in the room. The latter part
etas lecture only touched what the lectures tailed the
"e. onomieol question"—i.e., the question in which the
dituce was interested. This conclusion, however, was
practically intcreeting. As a rule, Mr. Forbes observed,
gold drift was only found in the neighbourhood of palseciaoic
rock., of rocks affected by the presence of igneous rocks of
a later date, and of tertiaries of the newest class comparable
with those tertiaries in which were found the remains of
extinct elephanta in Britain and of Kangaroos in Australia.
As a gas erai rule it would be a waste of time to scorch for
gold in any other demriptions of rocks ; and therefore the
gold searcher did not completely know his trade who was
not a geologist and who could not dyterinine the character
of the rocks by the fossils found in it. Expi rienee
in regard to Australia might affect the rule he had laid
down; but it was thus the matter stood at present. There
was a similar general rule as to coal; and the wealth of
Australia in coal was clearly very great, the present belief
being that coal was to be found in a district thereof 1,200
miles in length. It appeared that as a geueral rule applic-
able to all parts of the world coal was only found
in the neighbourhood of carboniferous rocks. Great
deposits of coal were found iu connexion with the
carboniferous epoch; and the presence of carbonife-
rous strata shown by the presence of carboniferous plants
would always guide -accurately the searchers fur coal.
Geology would also guide the agriculturist. As a rule in
Australia the " Sydney sandstone" was to be avoided by
the agriculturist. Tertiary sandstones were altogether to
be avoided, unless they were in the immediate neighbour-
hood of palasozoic rock., or what was better in the neigh-
bourhuod of igneous rocks. There was a certain set of
fossils of a well known character, and which could easily
be athertained, the presence of which, invariably in Aus-
tralia, were found to indicate a good soil. There was one
other point to which attention should be direct( d. la those
parts of the gold where gold-drift was found, diamonds were
also usually found, and this might prove to he the case in
Australia. Ile thought et rtainly that this would be so.
But everything that glittered was not to be taken as a dia-
mond. In California the experienced miner had worked in
the expectation of sometimes meeting with diamonds in the
gold districts, and diamonds had been found. But what
was not a diamond had often been mistaken for one ; and
as an iostance of which a man from the diggings had returned
with what he believed to be a large diamond, and for which
he had refused 2501., but which turned out to be only a
gne quartz crystal. The diamond was a very different thing.
Ito believed it to be of fossil origin, not improba-
bly derived from a vegetable substance ; and its
appearance was unmistakeable to the initiated from
all crystals. The Irish or Bristol diamond, or quarts crys-
tal, was known by its shape—a six-sided prism, capped Ity
a six-aided pyramid. The diamond was known by the
four-sided pyramid set against another four-sided pyramid.
In bringing his remarks to a close, the lecturer eloquently
advocated a cultivation of the knowledge on which be had
been dwelling fur other than mere utilitarian reasons.
Many of those about to proceed to Australia would nu doubt,
in the vicissitudes and necessities of Australian life, be de-
prived of society and of books, and be consigned for long
periods to absolute solitude, and therefore in Australia,
even more than in other countries, would a familiarity with
the " Books of Nature" be a compensation and a blessing.