e similar chemical depositions have
taken place in the past, and may still be in progress; indeed, there is
sound scientific reason to suppose that in certain localities this is
even now the case, and that in this way much of our so-called alluvial
gold has been formed, that is, by the deposition on metallic bases of
the gold held in solution.

We will, however, take, to begin with, the generally accepted theory as
to the occurrence of alluvial gold. First, let it be said, that certain
alluvial gold is unquestionably derived from the denudation of quartz
lodes. Such is the gold dust found in many Asiatic and African rivers,
in the great placer mines of California, as also the gold dust gained
from the beach sand on the west coast of New Zealand, or in the enormous
alluvial drifts of the Shoalhaven Valley, New South Wales. Of the
first, many fabulous tales are told to account for its being found in
particular spots each summer after the winter floods, and miraculous
agency was asserted, while the early beachcombers of the Hokitika
district found an equally ridiculous derivation for their gold, which
was always more plentiful after heavy weather. They imagined that the
breakers were disintegrating some abnormally rich auriferous reefs out
at sea, and that the resultant gold was washed up on the beach.

The facts are simply, with regard to the rivers, that the winter floods
break down the drifts in the banks and agitate the auriferous detritus,
thus acting as natural sluices, and cause the metal to accumulate
in favourable spots; whilst on the New Zealand coast the heavy seas
breaking on the shingly beach, carry off the lighter particles, leaving
behind the gold, which is so much heavier. These beaches are composed,
as also are the "terraces" behind, of enormous glacial and fluvial
deposits, all containing more or less gold, and extend inland to the
foot of the mountains.

It is almost certain that the usually fine gold got by hydraulicing in
Californian canyons, in the gullies of the New Zealand Alps, and the
great New South Wales drifts, is largely the result of the attrition of
the boulders and gravel of moraines, which has thus freed, to a certain
extent, the auriferous particles. But when we find large nuggety masses
of high carat gold in the beds of dead rivers, another origin has to be
sought.

As previously stated, there is fair reason to assume that at least
three salts of gold have existed, and, possibly, may