as would have
been the case had it been really waterworn, but that it presented the
same appearance, though infinitely finer in grain, as the surface of a
piece of metal fresh from the electrical plating-bath.

Mr. Daintree, of the Victorian Geological Survey, many years ago
discovered accidentally that gold chloride would deposit its metal on
a metallic base in the presence of any organic substance. Mr. Daintree
found that a piece of undissolved gold in a bottle containing chloride
of gold in solution had, owing to a portion of the cork having fallen
into the liquid, grown or accretionised so much that it could not be
extracted through the neck. This lead Mr. Charles Wilkinson, who
has contributed much to our scientific knowledge of metallurgy, to
experiment further in the same direction. He says: "Using the most
convenient salt of gold, the terchloride, and employing wood as the
decomposing agent, in order to imitate as closely as possible the
organic matter supposed to decompose the solution circulating through
the drifts, I first immersed a piece of cubic iron pyrites taken from
the coal formation of Cape Otway, far distant from any of our gold
rocks, and therefore less likely to contain gold than other pyrites. The
specimen (No. 1) was kept in dilute solution for about three weeks, and
is completely covered with a bright film of gold. I afterwards filed off
the gold from one side of a cube crystal to show the pyrites itself and
the thickness of the surrounding coating, which is thicker than ordinary
notepaper. If the conditions had continued favourable for a very
lengthened period, this specimen would doubtless have formed the nucleus
of a large nugget. Iron, copper, and arsenical pyrites, antimony,
galena, molybdenite, zinc blende, and wolfram were treated in the above
manner with similar results. In the above experiments a small chip of
wood was employed as the decomposing agent. In one instance I used a
piece of leather. All through the wood and leather gold was disseminated
in fine particles, and when cut through the characteristic metallic
lustre was brightly reflected. The first six of these sulphides were
also operated upon simply in the solution without organic matter; but
they remained unaltered."

Wilkinson found that when the solution of gold chloride was as strong
as, say, four grains to the ounce of water, that the pyrites or other
base began to decompose, and the iron sulphide changed to yellow oxide