tin. Lately this had been proved to be the case, and
I look forward to a great development of the tin mining industry in the
south-western portion of Westralia.

The tin "wash" in question may also contain gold, as the country rock of
the neighbourhood is such as gold is usually found in.[*]

[*] Since this book was in the printers' hands, the
discovery of payable gold has been reported from this
district. A detailed discussion of methods of prospecting
will be found in chapter ii. Of Le Neve Foster's "Ore and
Stone Mining," and Mr. S. Herbert Cox's "Handbook for
Prospectors."

CHAPTER IV

THE GENESIOLOGY OF GOLD--AURIFEROUS LODES

Up to a comparatively recent time it was considered heretical for any
one to advance the theory that gold had been deposited where found by
any other agency than that of fire. As late as 1860 Mr. Henry Rosales
convinced himself, and apparently the Victorian Government also,
that quartz veins with their enclosed metal had been ejected from
the interior of the earth in a molten state. His essay, which is very
ingenious and cleverly written, obtained a prize which the Government
had offered, but probably Mr. Rosales himself would not adduce the
same arguments in support of the volcanic or igneous theory to-day. His
phraseology is very technical; so much so that the ordinary inquirer
will find it somewhat difficult to follow his reasoning or understand
his arguments, which have apparently been founded only on the occurrence
of gold in some of the earlier discovered quartz lodes, and the
conclusions at which he arrived are not borne out by later experience.
He says:--"While, however, there are not apparent signs of mechanical
disturbances, during the long period that elapsed from the cooling
of the earth's surface to the deposition of the Silurian and Cambrian
systems, it is to be presumed that the internal igneous activity of the
earth's crust was in full force, so that on the inner side of it, in
obedience to the laws of specific gravity, chemical attraction, and
centrifugal force, a great segregation of silica in a molten state
took place. This molten silica continually accumulating, spreading,
and pressing against the horizontal Cambro-Silurian beds during a long
period at length forced its way through the superincumbent strata in all
directions; and it is abundantly evident, under the conditions of this
force and the resistance offered to its action,