420 M. BECQUEREL ON CHEMICAL DECOMPOSITION AND. 
pair, the particles of the solution, at the instant when they are set in 
motion by the chemical action, being then in their nascent state, are 
most disposed to obey the action of the current produced by the pair. 
We have already cited examples in confirmation of this fact, but we 
shall have occasion hereafter to notice a still greater number of them. 
Of the Formation of Metallic Oxides by Voltaic Action. 
Gold.—It was long supposed that gold was converted into a purple 
oxide by means of electric discharges ; but it appears that this state is 
only the effect of the extreme division of its parts, as it cannot be admitted 
that it is oxidized at the temperature at which its oxide is commonly 
reduced. It tends to confirm this conjecture, that when gold is preci- 
pitated from a very weak solution, we likewise obtain a purple powder 
by means of bodies which reduce its oxide. 
Iridium.—By exposing iridium to the discharge of a very powerful 
electric battery, Children succeeded in reducing this metal to a white 
globule, which was very brilliant and yet porous; but he never could 
oxidize it. 
Silver.—This metal when in contact with the air cannot be oxidized 
at any temperature; but it is found capable of oxidation when exposed 
in very thin leaves to the action of a very powerful battery. 
It may be obtained also in the state of hyper-oxide, a compound for 
the discovery of which we are indebted to Ritter. It deposits itself on 
the positive conductor of a pile, when that is discharged through a 
weak solution of silver, in long crystalline needles crossed by three or 
four lines possessing a metallic brilliancy. With a slow action it is ob- 
tained in very regular and well-defined tetrahedrons. When subjected 
to the action of hydrochloric acid, this compound gives out oxygen, and 
is transformed into chloride of silver; under the action of ammonia it is 
decomposed and gives out azote, and when mixed with phosphorus it 
detonates under the hammer. It decrepitates by heat, is decomposed, 
and produces pure silver. 
Mercury.—When a very powerful electric pile is discharged through 
a very small globule of mercury, the globule is driven in all directions, 
becomes oxidized, and produces red sparks. 
- Palladium is not oxided at the positive pole of the pile. 
Antimony.—When a piece of antimony is employed as a positive con- 
ductor in order to decompose water, gray flakes are detached from its 
surface; these, under the action of hydrochloric acid, are transformed 
into antimony which remains, and into oxide of antimony which is dis- 
solved. The flakes appear to be a suboxide. 
- Zine and the oxidable metals are easily oxidized under voltaic influ- 
