556 Transactions.—Chemistry. 
side, shows the more complex ones are of a distinct yellower shade of colour 
than the others. 
In the ease of silver iodide, however, the change which ensues when 
mercuric iodide combines with it is so striking, that it seems very remarkable 
this combination has not before been proved to be possible. The iodide of 
silver is, as you are aware, of a very pale yellow colour, and the effect of a 
solution of mercuric iodide upon it is to heighten its colour instantly toa 
very deep good yellow. As in the case of the detection of alkaloidal matter, 
however, by the mercuric iodide test, it is necessary to avoid excess of either 
potassie iodide or mercuric chloride in this reagent when we wish to 
prepare these double metallic iodides, a circumstance which may account 
for the fact that they have not hitherto been formed. 
Art. LXXXIV.—On the Composition of the Silver Ore of Richmond Hill By 
Wittram Srey, Analyst to the Geological Survey of New Zealand. 
[Read before the Wellington Philosophical Society, 24th February, 1877.3 
Tuis ore was discovered in the year 1875, by Mr. James Washbourne, and a 
sample of it (No. 1692) was forwarded to the Colonial Laboratory as an iron 
ore, with the request that its richness in this metal might be ascertained, but - 
upon being examined by me it proved to be more of a lead than an iron one, 
and besides, argentiferous to a remarkable extent, no less than 185 ounces 
of silver being present in it, as calculated upon the ton. This interesting 
fact was duly announced, and, in consequence, numerous other samples of 
ore from this locality were t itted here for assay, and the results of these, 
though varying greatly, (from 82 ozs. 15 dwts., to 596 ozs. per ton,) showed 
unmistakeably that silver exists in the Richmond Hill district in considerable 
quantity, and that by careful selections from the several lodes now opened, 
silver-mining should pay there, and pay well. The precise position of the 
lode, from which the first sample was taken, is, according to the prospectors 
of it, one mile above Richmond Hill, five miles more or less bearing S.S. W., 
crossing the Parapara River three miles south of Collingwood. The lode 
from which the specimen was taken, that yielded at the rate of 596 ozs. 
of silver per ton, is about seven inches thick, and the specimen itself 
weighed upwards of nine pounds, and upon this I have, in accordance with 
instructions, performed the complete quantitative analysis, which forms the 
leading subject of my paper; this ore, of all the specimens to this time 
received here from Richmond Hill, being supposed to best represent the 
mineralogieal character of the silver-bearing ore of the lodes there to this 
