Sxey.—Electro-motive Order of Certain Metals, 337 
iron of which their receiving part is made, as also the ball, is very negative 
to gold under the circumstances stated. 
The loss of gold in this way will be also greater the more free cyanide 
of potassium there is present, proportional to the stuff ; when the quantity 
is small the loss is perhaps not serious. 
Whatever it is, however, I think it may be avoided, at least in a greater 
part by allowing the waste liquor from the blankettings to run in a thin 
stream over copper plates, . 
Art. XLIV.—On the Absorption of Antimony and Arsenic from a Solution of 
their Oxides in Hydrochloric Acid by Charcoal. By* Wiutam Sxey, 
Analyst to the Geological Survey of New Zealand. 
(Read before the Wellington Philosophical Society, January 29, 1876.} 
Some time back I showed* that charcoal, when freshly made or ignited, 
absorbs, from their aqueous or acid solutions, several substances not before 
known as being affected in this manner, and I proposed to apply this 
reaction to the purification of certain of our chemical re-agents from sub- 
stances difficult or tedious to remove by the processes now in use for this 
purpose, 
Since then I have made further investigations in this direction, and 
find that antimony and arsenic can be so largely removed from solutions of 
their oxides or chlorides in moderately strong hydrochloric acid (with a 
little tartaric acid in the case of antimony) by fresh charcoal, that neither 
of them can be detected therein by Reinsch’s test, although before such 
process was applied both were abundantly evidenced to the test named. 
hus commercial sulphuric and hydrochloric acids diluted with a little 
water can be purified from either of these substances by agitating them 
intermittingly for a short time with fresh charcoal, and then filtering off; 
application of heat to the mixture expedites this result. 
The charcoal used does not appear to give up any portion of either the 
antimony or arsenic when digested with an aqueous solution of potash, 
hence I consider it very probable that it would absorb either of these metals 
from alkaline solutions also. Such charcoal, however, when placed in 
voltaic contact with pure zine in hydrochloric acid, evolves antimoniuretted 
or arseniuretted hydrogen (as the case may be) very perceptibly, and it can 
be wholly divested of either of these substance, when treated in this manner. 
In connection with this evolution of such hydrides from charcoal under 
the circumstances just stated, I will observe here that sulphur, when 
* “ Chemical News,” March 27, 1868, 
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