41 
i the beautiful reds called ruby glass being due to the presence of it in small quan- , 
a titles. In photography it is also of great value, owing to the permanency of the 
i beautiful tones that can be obtained by replacing the silver in the original print 
'I with it, and a great variety of shades are produced, varying from black, blue, pink 
!j to brown. 
ITS OCCURRENCE. 
Gold, as was before said, is always found in nature in the metallic state, but 
mostly alloyed with small quantities of other metals. It was formerly supposed 
to be always associated with quartz, which was considered to be an indication of 
it, but this idea has exploded, as it has now been found with calcite, serpentine, 
diorite, and granite, and associated with the ores of lead, iron, antimony, copper, 
and tin. It is true,' certainly, that quartz commonly occurs with it, but the white 
quartz reefs which were first worked have not, as a rule, proved as rich as the 
more mineralised veins. Athough always found in the metallic state, it is highly 
probable that it also exists in nature as a sulphide, but as this salt is so unstable, 
it would be decomposed before this could be determined. Gold occurs in nature 
in two forms, namely alluvial gold and reef gold. In the former state it is found 
m the stream beds, where it has been derived directly from the reefs by the eroding 
action of the stream, the gold being left behind at the bottom of the gully, owing 
to its great specific gravity, whilst the lighter minerals have been washed away. 
Gold in the alluvial form is generally of a higher value than reef gold. This 
may be accounted for by the oxidization of the baser metals with which it is 
alloyed, as in the finely divided state this separation is easily effected. Even if a 
coin like a sovereign is taken and heated to redness, the surface will be tarnished 
either a reddish or blackish colour, owing to the thin coating of oxide of copper, 
and when this is removed the gold on the surface of the coin will be found to be 
chemically purer. 
Another strange thing about alluvial gold is that it is found in much larger 
masses in the alluvium than it has ever been found in a reef, often occurring as 
miggets of many pounds weight, whilst in the reef from which it was derived it is 
only met with in a finely divided state. This has given rise to the miner’s theory 
that gold grows, and can be accounted for by the fact that pockets or ledges 
become filled with fine gold, when by some very slow process, the action of which 
Wo do not yet know, the whole becomes one solid mass. That such an action takes 
place we know, for we always find alluvial gold taking its shape from the bottoms 
holes in which it has been accumulated, often appearing as if it had been poured 
mto the crevices in a molten state. This joining together of the small particles 
gold is probably due to the small amount of gold in solution, which is 
deposited on the surface of the grains until it eventually joins them together. 
Reef gold occurs in veins, lodes, or dykes, the term reef or vein being used to 
describe a lode where there is a predominance of an earthy mineral, lode where an 
°re or metallic mineral is in the larger proportion, and a dyke when it owes its 
°i’igin to plutonic action, the matrix being an igneous rock. These reefs and veins 
mostly occur in the older Palaeozoic formation, the rocks being generally clay, 
slate, sandstone, schist, &e. 
AURIFEROUS BELTS OF THIS COLONY. 
There are five auriferous belts in this colony, the first of which runs nearly 
North and South, about 200 to 250 miles from the coast, in the Southern portion 
°f the colony, and it is on this belt that Yilgarn and the Murchison goldfields are 
situated. The Ooolgardie belt, about 100 miles to the Eastward and parallel to 
the Yilgarn belt, extending from the Dundas Hills through Ooolgardie, Ularring, 
to the Eastward of the Murchison. On the Ashburton the belt runs North-West 
ari( l South-East, but is probably the extension of the Yilgarn belt, which ends at 
