78 - A, LIVERSIDGE. 
A plate of copper was thickly coated with gold accor 
and etched but only a minute crystalline structure was obtained. 
A fillet of nominally pure silver presented a minutely crystalline 
structure, quite unlike the gold fillets. 
I had hoped to obtain and examine a specimen of “brittle” gold 
from the Sydney Mint, but none happened to be produced at the 
time, as its crystalline structure would be of interest and it might 
perhaps afford information which would be of use. 
For comparison an ingot of tin was etched by nitro-hydrochlori¢ 
acid, with the result shown in Plate 16; the ingot weighed about 
20 Ibs., only a small part of its surface is shown in the plate. 
The well known moiré-métallique structure became visible 
immediately on moistening with the acid; the etching was continued 
until about one-quarter inch in depth had been dissolved away, 
the outlines of the crystals apparently underwent no change, and 
the surface remained quite smooth, i.e., none of the crystals were 
dissolved away more quickly than the others, and no grooves were 
eaten out along their edges. The gold nuggets, ingots and fillets 
behaved quite differently, that is, grooves were eaten out at the 
junctions of the gold crystals, and some were sunken below the 
others so that the etched surfaces of the gold could be printed 
from, and the differences of level seen and felt, nothing of the kind 
happened with the tin ingot. 
I have much pleasure in acknowledging the very great assistance 
I have received from the Deputy Master and the officers of the 
Sydney Mint in specially preparing and slicing the heavy ingots 
of gold for me, and for their cordial codperation generally. 
Conciusion. 
A great deal requires to be done to complete this investigation, 
but as far as it goes it proves that gold nuggets do not show that 
they have been built up of concentric coatings round a nucleus, 
but that they possess a well marked internal crystalline structure 
and that they usually enclose foreign substances, also that a similar 
crystalline structure is shown by gold which has been fused ; I do 
