Cases of Voltaic Action. 429 
outer cylinder of the first jar with the inner one of the second, 
and so on; the porous tube was then filled with strong nitric 
acid, and the jar with solution of sulphuret of potassium. 
The arrangement is exactly similar to Daniell’s constant bat- 
tery, except that the metallic surfaces are entirely of platina. 
With an instrument of the above dimensions, I have ob- 
tained by means of a voltameter, 0°5th cubic inch of the mixed 
gases in a minute, and that action continues for some hours, 
with very little diminution. 
I find that the substances capable of producing a current 
in similar circumstances, are very numerous; for example, per- 
and protosalts of iron, tin, and manganese, an alkaline sul- 
phuret hyposulphite, hypophosphite or a hydracid on the one 
side, and chlorine or chromic or nitric acid on the other. 
The intensity of the effect is, however, very various in 
these different combinations; thus, with salts of iron it is very 
feeble; while with chlorine or nitric acid and an alkaline 
sulphuret, the intensity is such, that the induction of one pair 
of plates is sufficient to cause the decomposition of water. 
Each of the combinations, it will be observed, is formed of 
an oxidating and a deoxidating substance, and the change 
which takes place’is similar in all of them; the oxidating sub- 
stance is reduced and the deoxidating is oxidated. 
If we employ only one substance, for example—chlorine, 
the chlorous element of the water finding nothing with which 
it can unite, is evolved; but in that case the intensity of the 
action is very much reduced. 
The mode in which the experiments were performed was 
very simple. A small vessel of baked clay was cemented 
inside a wine glass; the respective liquids were then poured 
into this vessel and into the glass, till they stood at the same 
level ; in this way they were in free liquid contact, while their 
actual mixture proceeded with extreme slowness; metallic 
plates, which were in all cases of platina, were then plunged 
into the solutions; the plates had been carefully cleaned with 
nitric acid, then with potash, and washed with water. 
I now proceed to state the conclusions at which I have 
arrived, as regards the law which regulates the action in the 
ordinary voltaic battery, and in the arrangements above 
mentioned. 
This I find to be in strict agreement with that of ordinary 
mechanical forces, viz. that the action and reaction are equal 
and opposite. When a metal is reduced from its solution, 
the equal reaction seems to follow as a corollary to the law of 
definite electrolyzation, and in cases where no solid substance 
is deposited, the same law holds. 
