248 JOURNAL OF SCIENCE. 
By Miller’s refining process with chlorine gas, by which since 
1869 to present date, over 720,000 oz. of silver—more than 20 tons 
—have been extracted in this Mint out of the gold imported, the 
present quantity of silver thus obtained being between 40 and 50 
thousand oz. per year, the gold is obtained of an average fineness 
of 99 6-10ths per cent., some being as high as gg 8-r1oths per cent. 
The occurrence of this almost pure gold at Mount Morgan sug- 
gested the experiment of submitting the same to a short chlorina- 
tion process whereby the small quantity of copper, &c., would be 
readily eliminated. The result of such chlorination carried out in 
an unglazed clay crucible was highly satistactory. I have here 
some of the gold which has been subjected toa series of most 
carefully-conducted assays, and compared with fine gold received 
from the chemist of the London Mint—Professor Chandler Roberts 
—with the result that it was tound to be absolutely fine, and since 
the process by which it became so is a very short and simple one, 
I was very glad of seeing it so successful. 3, Volatilisation of 
Gold.—On this subject a vast amount of notices have from time to 
time appeared in print, and the slight volatility of gold under cer- 
tain conditions is therefore nothing new. The erection ofa 
scaffolding round the mint chimney preparatory to its being repaired 
enabled me to get some of the stuft which was found outside the 
chimney on the very top coping-stone. This stuff, of which, how- 
ever, there was but little, was found to contain in 235 grains of 
sweep 3°424 grains of gold and 14'242 grains of silver, or about 
1°46 per cent. gold and 6:06 per cent silver. The gold could be 
seen under the microscope. The horizontal flues in front ot the 
melting furnaces, as well as the case of the chimney to the height ' 
of about 20 feet, are periodically swept, and gold and silver ex- 
tracted therefrom. Since the mint chimney is about 70 feet high, 
it shows how under certain conditions and strong draught some 
gold is carried to the top, and probably beyond. In conclusion, I 
would draw your attention to several interesting specimens of 
auriferous ores, and also a beautiful specimen of native silver from 
the Boorook mine, which I have brought here for your inspection.” 
2. ‘On the Oven Mounds of the Aborigines in Victoria,” by the 
Rev. P. Macpherson, M.A. 
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