the head of this river. The Roebourne belt strikes East and West along the 
North-West coast from the Nicol River to the DcGrey River, disappearing 
beneath the sandv table-land to the Eastward. Tho Kimberley belt strikes in 
a North-East and South-West direction, and is very probably the extension of 
the Roebourne belt, re-appearing on the North-Easterly side of the sandy table¬ 
land. These belts carry gold for a great length; the reefs, as a rule, are of 
great size, very rich, and wherever they have been tested they have proved to be 
good. A large quantity of stone has been crushed from the different lields, which 
has averaged loz. to the ton of stone, whilst alluvial patches of great value 
are still being worked. Gold also occurs associated with pyrites along the 
Darling Range, at Kendinup, Bindoon, the Wongan Hills, and the Eastern 
districts; it has also been found in stone at Yuin and in the alluvial form at 
Peterwangy, at the head of the Irwin. Gold mining here is in its infancy, not 
yet being ten years old; but as during this time it has made great progress, 
especially during the last year or two, there is every prospect that this colony, 
before long, will be one of the chief gold-producing countries of the world. 
Silver. 
Symbol , Ay (Argentum ) ; atomic weight , 107'9S ; specific gravity , 10'5. 
Silver has been known and used from the earliest times as currency and for 
jewellery. In colour, when seen in a mass, it is of a lovely silver white, and may 
be distinguished readily by an expert from other metals or alloys. Very thin 
leaves of it, viewed by bright transmitted light, appear to be blue. 
The lustre of it is brilliant, and it will take nearly as high a polish as steel. 
Its hardness is 2*5, but this is increased by hammering or rolling, but can be 
again softened by heating and gradually cooling, called annealing. 
Silver in the metallic state may be distinguished from the other white 
minerals by not giving off fumes before the blowpipe, and by its solubility in 
nitric acid, from which solution it is precipitated by common salt in a white pre¬ 
cipitate, which blackens on exposure to the air. 
It is distinguished from platinum as it fuses, and from lead as it will not 
mark paper; it does not crackle when put between the teeth, like tin, and is more 
malleable than most of the other common white metals. 
It can be beaten out into leaves fohro an inch in thickness, and a grain of 
it may be drawn into a wire 400ft. in length. This wire is very tenacious; when of 
a thickness of T \y of an inch it will support a weight of 2401bs. It melts at a 
temperature of 1800° E., and may be volatilised by the voltaic arc or by the oxyhy¬ 
drogen blowpipe, when it appears as a bluish vapour. It is the best known con¬ 
ductor of heat and electricity. 
Silver has no affinity for oxygen at ordinary temperature, but when in the 
molten state it absorbs 22 times its own bulk, which is again disengaged on 
cooling, the mass suddenly becoming incandescent, called flashing. 
The black tarnish observed on silver in towns is due to the presence of small 
quantities of sulphuretted hydrogen in the air, which the silver decomposes, form¬ 
ing a sulphide on its surface. 
Silver is too soft to stand much wear, therefore it is generally alloyed with 
copper, the British standard coinage containing 7 ‘5 per cent, of the latter metal. It 
occurs in nature in the metallic or native state, alloyed with gold and copper, also 
in combination with sulphur, silenium, tellurium, arsenic, antimony, chlorine, 
bromine, and iodine; many varieties of copper, lead, manganese, and iron ores 
contain notable quantities of it, and it has also been detected in sea water, but 
has never been found as an oxide, carbonate, sulphate, or phosphate. 
