364 A. LIVERSIDGE. 
No. 12. Richmond River.—Placed on back of fourth pile, 
middle row from southern end of High Level wharf, Coraki, 
Fixed 4th November, 1893, in brackish water. 
No. 12a. Macleay River.—Placed on middle pile of outside tier 
and on back of pile from front of Central Kempsey wharf. Fixed 
21st November, 1893, in brackish water. The new metal gave— 
Silver. Gold. 
1000 grains gave 11 oz. 14 dwt. 5 grs. 23-5 grs. per ton. 
Only three of the experimental plates have been removed and 
assayed, viz., No. 1 Ballina, No. la Moruya, and No. 7 Coraki, 
after an exposure of twenty-three months ; the others will be left 
on fora longer period. In all three cases there was a loss in 
silver and an increase in the amount of gold. 
It is unfortunate that the presence of the platinum in the 
otherwise pure sulphuric acid was not detected earlier, as T have 
not the time now to repeat the determinations of gold which had 
to be rejected on that account ; but even without them there are 
perhaps sufficient assays to settle the question. , 
The average amounts of gold and silver obtained are :— 
Silver. Gold. 
‘ oz. dwt. grs. oz. dwt. grs. 
12 specimens new muntz metal 9 4 7:6 0 0 23 per ton 
~ » old 9 413 19 0 0 1627, 
Average decrease ... £1 es 00 68 4 
It is not quite satisfactory to have to compare the assays of old 
Specimens of metal with those of new ones, but the old specimens 
of muntz metal are not likely to have originally contained less 
gold and silver than the new, in fact they probably contained — 
very much more, so that the difference is all the more striking 
The assays of the metals from the “ Topsy,” the second lot from 
the Circular Quay and from Newcastle are omitted from the above : 
because some of them were made with the sulphuric acid after- 
wards found to contain platinum. 
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gee VB Pent S MAS Ree SEA Seen Sey A a ele ac a en a i See ee eae 
