246 JOURNAL OF SCIENCE. 
quarter of the usual cost. They are very reticent as to the amount 
of stone they are putting through and the yield obtained ; but we 
understand about too tons are being crushed at No. 1 battery, and 
130 at No. 2, weekly. The return is said to be not less than 50z. 
to the ton.” While, however, especially from a geological point of 
view, the occurrence of this gold is highly interesting, the character 
of the gold obtained is not less so. Lock, in his work on gold, pub- 
lished 1882, says:—‘* No gold has yet been found in nature 
unalloyed with silver,” yet this gold trom the Mount Morgan mine, 
of which since February last already over 10,000 oz. have been 
received as retorted gold at the Sydney Mint, is found to be free 
from silver—a minute trace excepted. I have brought some of 
this retorted gold rolled out very thin, to show its toughness. It 
assays gg and 7-10ths per cent. of gold ; the rest is copper, with a 
trace of iron. Gold assaying 99 and 7-1oths per cent. is worth £4 
4s. 3d. per oz. Gold from the same mine received at the Mint 
assayed as high as gg and 8-1oths percent. Itis, as far as I know, 
the richest native gold hitherto tound. The richest gold next to 
this comes, I believe, from Maryborough, Victoria, which assays 
gg and 3-1oths per cent.; while that from its namesake in Queens- 
land contains only 85 per cent. gold. F. B. Miller, in his paper on 
‘“‘Gold-refining by Chlorine Gas,” read before this society in 1869. 
alludes to the curious fact that as a. rule the gold contains more 
silver as we go northwards, giving the average fineness of Victoria 
gold as 96 per cent., New South Wales 93 per cent , and Queens- 
land 87 per cent. He says, however, ‘“‘ these are averages only. 
It is not to be supposed that there is a regular and consecutive 
diminution in fineness with every degree of latitude we go north. 
There are exceptional localities in the north of this colony, as at 
Rocky River, where the gold is over 96 per cent. To these ex- 
ceptions we must now add the gold from Mount Morgan. Having 
now shortly described the remarkable occurrence and purity of 
this Mount Morgan gold, a not less interesting, though less satis- 
factory fact is this—that only about half the gold is extracted by 
the ordinary quartz-crushing and amalgamating machinery. The 
Capricormian says :—‘‘ The tailings which are being stored are said 
to contain as much gold as is saved, and, as they will be subjected 
to treatment at a future date, the result will be highly advantageous 
to the owners.” Haviug the small quartz-crushing machinery 
erected at the Sydney Mint under my charge, I have had 
an opportunity of testing this fact. In November last we 
received, through Mr. Hall, of Sydney, 458lb. of this fer- 
ruginous quartz, part of it consisting of picked stone. It 
was carefully crushed and amalgamated in the Chilian 
mill, with 240lb. of mercury. Thus 7 44-100 oz. of gold, assaying 
991.5 were extracted. Another lot, weighing 174lb., was similarly 
treated, and 12 12-100 oz. of gold extracted, assaying 998-2. Thus 
lot 1 gave gold at the rate of 39 32-100 oz. standard per ton of 
quartz.; while lot 2 gave gold at the rate of 169 86-100 oz. standard 
per ton of quartz. In lot 1 gold at the rate of 460z. 2dwt. 12gr. 
per ton was left in the tailings ; while in lot 2 the tailings assayed 
640Z. 5dwt. 18grs. of gold per ton. Both lots of tailings were now 
mixed and passed for two hours inthe Chilian mill with 24olb, clean 
retorted mercury—only 1 66-100 oz, of gold, assaying ‘981 were, 
however, obtained by this treatment. The tailings were dried and 
