W. SKEY.— Formation of Gold Nuggets in Drift. 377 
The modification therefore which I propose is the use of acetate of copper 
in place of the iodide, this salt, as also free acetic acid and alkaline acetates, 
dissolving the cupreous iodide to only a very slight extent. 
For practical use this salt might be prepared from common sulphate of 
- copper by adding thereto acetate of soda in quantity sufficient to allow of the 
whole of the sulphuric acid of the copper salt being interchanged for acetic 
acid, but for the more complete removal of iodine I should recommend the 
use of the acetate of copper alone. 
I will only state further that the pure acetate of copper (acidified with 
acetic acid if necessary) is so delicate a test for iodine, if in the form of a soluble 
iodide, that it may very effectively and conveniently be used for this purpose 
in place of the expensive salt, chloride of palladium ; indeed, by this process 
I have readily detected iodine in certain waters from the east coast of this 
(North) Island. 
Art. LV.—On the Formation of Gold Nuggets in Drift. By W. SKEY, 
Analyst to the Geological Survey of New Zealand. 
[Read before the Wellington Philosophical Society, 23rd October, 1872.] 
THE manner in which those gold nuggets have been formed which are found 
in our drift or fluviatile deposits has long been a subject of profound interest. 
Our Victorian friends in particular have been greatly exercised with this 
matter, no doubt from having it so frequently and forcibly presented to them, 
by the almost regular announcement from time to time of the discovery of 
nuggets so large as to be entitled to description in the annals of their gold 
fields, and to names to identify them by. 
From the circumstance of their attention being thus given to this subject 
many valuable observations have been recorded by them and published in the 
periodicals or other works emanating from their colony. 
The first theory broached to account for the presence of these nuggets in 
drifts was that they had been broken off some rich reef and transported by 
water bodily to the positions in which they are now found by us. At first sight 
this appears very plausible, but there are several considerations which, when 
allowed to have their due weight, rather tend to shake our belief in its 
competency to explain the case. These considerations have been discussed 
pretty freely in the works alluded to so I need not detail them here, but will 
only state that, briefly put, the chief of them are as follows :—The large size 
of many of these nuggets as compared with any of the masses of gold yet found 
in our reefs; their position in the drifts, lying sometimes as they do in the 
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