Sxuy.—Solubility of Alkali in Ether. 539 
obtained by dipping reddened litmus paper into it, and which is more 
intense than can be occasioned by any minute trace of alkaline acetate 
possibly present in the ether, resulting from an inter-reaction of the potash 
upon it, 
The alkalies and their inferior carbonates, therefore, not being insoluble 
in ether, and alkaloidal carbonates being, as I find, freely soluble therein, 
- I would recommend in special cases, for isolating and obtaining pure 
alkaloids by Stras’s process the use of bi-carbonate of soda, or, better still, 
an earthy carbonate, in place of caustic alkali, as now employed in aid of 
this. 
I may perhaps be permitted to state further in reference to the solvent 
property of anhydrous ether, that I find many salts are soluble to a notable 
extent in it, which are insoluble or nearly so in that which is hydrous; for 
instance, the chlorides of calcium, nickel, zinc, cadmium, and platinum, 
also the sulpho-cyanides of nickel, copper, and zinc. The addition of a 
small quantity of water to any of these etherial solutions generally renders 
them very turbid, as the salt they contain is thereby precipitated as a 
hydrate. By the use of anhydrous ether, and by conducting the necessary 
evaporations in dried air, it is in fact possible to form many saline com- 
pounds hardly, if at all, producible otherwise. In this way I have prepared 
double sulpho-cyanides of nickel and even of copper with certain alkaloids, 
using chloride of calcium to dehydrate the saline solutions requisite for this, 
Art. XLVI.—On the Oxidation of Gold, and supposed Oxidation of Mercury 
by Oxygen in presence of Water. By Wiiu1am Sxey, Analyst to the 
Geological Survey of New Zealand. 
[Read before the Wellington Philosophical Society, 12th February, 1876.] 
Tus paper states the results of the investigation I promised at our last 
meeting relative to the oxidation or otherwise of gold, under circumstances 
which have not been hitherto supposed favourable for such oxidation. They 
show, and I think pretty clearly, that this metal is oxidized superficially 
under them, as seems demonstrated by the following facts which I give as 
expressing the general results of the very numerous and often repeated ex- 
periments which I have made :— 
1. That gold immersed for a few hours in spring water, or in water 
charged with any neutral salt, refuses for a long time to amalga- 
mate when next immersed in mercury. 
2. That it is also passed to this condition by contact for about eighteen 
hours with distilled water, from which ammonia and other 
nitrogen compounds have been removed. 
