ORIGIN OF GOLD NUGGETS. 303 
Some alluvial gold which I obtained on the spot at Fairfield, 
New England, N.S.W. was examined; on removing the fine sand 
from this by washing, the gold under the microscope did not look 
waterworn but obscurely crystallised, a more or less complete 
.octohedral face being occasionally seen. The gold was obtained 
from a spot close to the reef, and had evidently not travelled 
many feet. 
The really good crystals of gold all appear to have formed in 
what are now cavities, usually left by the removal of iron pyrites, 
or else in very soft matrices like iron oxides, clay, calcite, and 
serpentine as already mentioned. 
ON THE ORIGIN OF GOLD NUGGETS. 
By A. LIVERSIDGE, M.A., F.B.S. 
Professor of Chemistry in the University of Sydney. 
[Read before the Royal Society of N. S. Wales, September 6, 1893. | 
From time to time various theories have been put forth to account 
for the existence of alluvial gold and nuggets, i.e., other than the 
dld and generally accepted one, viz., that such gold has been 
derived or set free from mineral veins and rocks by the ordinary 
processes of disintegration and denudation. 
The one first propounded by Mr. A. R. C. Selwyn, c.M.G., F.R.S., 
when Government Geologist to Victoria, has always interested 
me, and within the last two years I have been able to make some 
experiments bearing upon the matter, but before stating the 
xesults I will refer briefly to some of the theories above referred to. 
Simpson Davison advanced a theory (The Discovery and 
Geognosy of Gold Deposits in Australia, p. 132, London 1860)— 
“that alluvial or placer deposit gold has been distributed and 
