298 A. LIVERSIDGE. 
potassium cyanide a yellow metallic button of Au, As,, sp. gr.16°2,. 
is obtained. 
The above references were made after I had completed the: 
experiments given in this paper, and they are quoted merely as. 
of historical interest. 
Asa result of the foregoing experiments and observations I 
conclude that the peculiar form of the moss gold is due to the 
formation of a fusible compound with arsenic, which behaves in. 
much the same way as fused bituminous coal—to which I referred: 
in my first paper (Jour. Roy. Soc. N.S.W., Vol. x., 1876, p. 125) as. 
follows :—‘‘ The general appearance of these peculiar cauliflower- 
like excrescences of gold would at first sight tend to give one the: 
impression that they had been formed in somewhat the same way 
as the blebs and excrescences often observed on coke, which are: 
so familiar to us in a fire made of the so-called bituminous coal,. 
1.e., caking coal, in which we constantly see portions of the coal! 
fuse and swell up into fantastic blebs and bladders until the 
imprisoned gas breaks through the outer thin skin and inflames: 
with a brilliant light. After the more combustible portions have 
been volatilized and consumed a hard clinkery and more or less. 
cauliflower-like excrescence is left.” In the cavities of such cinder’ 
we may often see spicules and acicular threads of coke. 
In that paper I came to the conclusion that the moss like forms: 
of gold could not be due to fusion, because the experiments were: 
conducted at temperatures far below the fusing point of gold or 
mispickel, but my later investigations show that the moss gold. 
is due to the fusion of the very fusible gold arsenide and to the: 
escape of arsenic from it, blowing it up into excrescences, spicules: 
and spiral threads, and that the crystallised appearance in places 
is due to the ready crystallization of the alloy on solidification. | 
In the auriferous mispickel the gold appears to be in the free J 
condition, but to be converted into gold arsenide during the roast- 
ing, and it is from this gold arsenide that the moss gold is produced. 
