Sxey.—Deportment of Argentic Sulphide. B45 
required to produce mercurous films such as I have obtained. 
But in regard to the question how these deposits are induced upon 
mercury, I find that hydrochloric acid even readily attacks mercury when 
paired voltaically with platinum, and, as platinumsmust act thus because 
of the oxygen condensed (chemically) upon its surface; and further, as 
gold will certainly possess a similar though a feebler power of condensation 
for this gas, we must consider the possibility of a part of the mercurous 
deposits produced in all these experiments being indirectly due to the 
metals used in them for the negative element. In these reactions we may 
safely suppose a portion of the hydrochloric acid present is decomposed ; 
the oxygen condensed upon the negative element oxidizing its hydrogen, 
while its chlorine attacks the mercury. It is, in fact, a case where both 
poles conspire to give an effect not producible by either separately, and, as 
now known, it may throw a light upon the mode in which chemical action 
is so frequently facilitated, or even at times initiated by touching the 
positive metal with a metal negative to it in the liquid we may be operating 
with. It appears to me that this matter is well worth investigating, 
Arr. XLVUI.—Notes on the Electric and Chemical Deportment of Argentic 
Sulphide. By Witt1am Srey, Analyist to the Geological Survey of 
New Zealand. 
In a paper I have given* on the Conducting Power of Sulphides, it is stated 
that Argentic Sulphide is a good conductor of electricity for a sulphide. I 
find, however, since this table was compiled that the deportment of this 
substance into electric currents is a subject which has given rise to some 
controversy, and that the results as published leave a uniform impression 
upon chemists that Argentic Sulphide is not an electric conductor in the 
sense this is usually and properly taken—i.e., not a conductor as a metal 
is without decomposition. 
Thus Professor Faraday supposed it “ conducts electricity like a metal, 
without decomposition ; its conducting power, however, increasing with rise 
of temperature ;’’ while Hittorf is said to show “ that, when this compound 
is free from metallic silver, it conducts only in proportion as it is decom- 
' posed,”’ 
A knowledge of these conflicting opinions, and of the fact that their 
tendency is, as the matter now rests, one of antagonism to that of my own 
opinion on the subject just quoted, induced me to repeat the experiments 
“ Trans, N.Z, Inst.,” Vol, IV., Art. LI. 
Tl 
