40 EXPERIMEN'I’S BY FARADAY LEADING TO IMPORTANT RESULTS. 
electrolyte through which the current passes 
undergoes decomposition. 
Currents of electricity produced by less 
than eight or ten series of voltaic elements 
can be reduced to that intensity at which 
water can conduct them without suffering de- 
composition, by causing them to pass through 
three or four vessels, in which water shall be 
successively interposed between platinum sur- 
faces. 
'This subject is worthy of prosecution, 
in order to enable us to arrange electrolytes 
in the order of their electrolytic intensities. In 
terminating this portion of his paper, the au- 
thor observes, in relation to intensity general- 
ly, that when a voltaic current is produced, 
having a certain intensity dependant upon the 
strength of the chemical affinities by which 
that current is excited, it can decompose a 
pai'ticular electrolyte without relation to the 
quantity of electricity passed, the descompo- 
sition of the electrolyte being pioduced, if the 
intensity is too high. If this be confirmed, 
then w'e may arrange matters so that the 
same quantity of electricity may pass in the 
same time into the same decomposing body, 
in the same state, and yet differ in intensity, 
decomposing in one case, and in the other 
not. 
III. VOLTAIC BATTERY.-From the 
principles laid down, it is evident that the 
quantity of electricity in the current cannot be 
increased by multiplying the quantity of 
metal oxidized ; a single pair of plates, 
throwing as much electricity into the form of 
a current, by the oxidation of 32’5 grs. of 
zinc as would be produced by increasing the 
quantity of oxidized metal a thousand times. 
For the action in each cell is not to increase 
the quantity set in motion in any one cell, but 
to assist in urging that quantity forward, and 
in this manner, the intensity, is increased with- 
out affecting the quantity ,heyon.d what is pro- 
portionate to the zinc oxidized in any single 
cell of the series. Ten pairs of amalgama- 
ted zinc and platinum plates, when acted upon 
by sulphuric acid, pioduced such a quantity 
of gas as to prove that just as much electrici- 
ty, and no more, had passed through the series 
often pairs ofplates, as had been transmitted 
through or would have been put in motion by 
any single pair, notwithstanding the consump- 
tion of ten times the quantity of zinc. All these 
facts tend to shew that the act of decomposi- 
tion opposes a certain obstruction to the pas- 
sage of the electric current, and that this op- 
posing force is overcome in proportion to the 
intensity of the decomposing current. When 
ordinary zinc is used in a voltaic pile, the 
waste of power is very great, for 3^ ounces of 
zinc, properly oxidized, can circulate a cur- 
rent capable of decomposing nearly an ounce of 
water, and of evolving 2400 cubic inches of 
hydrogen. This waste, however, is greater 
with common zinc than with the pure metal, 
for, when common zinc is acted upon by 
dilute sulphuric acid, portions of copper, lead, 
cadmium, are set free on its surface, and form 
small but active voltaic circles, which act ap- 
parently on the zinc surface, but, in reality, 
upon those accidental metals. This effect is 
removed by employing amalgamated zinc 
plates, which afford the full equivalent of 
electricity for the oxydation of a ceilain 
quantity of zinc, but are active only when 
the electrodes are connecterl. This im- 
provement in the voltaic battery is of great 
importance, for effects of decomposition can 
now be obtained with ten pairs of plates, 
which formerly required 500 or 1000 pairs of 
plates. Dr. Faraday conceives that in 
further improving the battery, plates of plati- 
num or silyermay very likely be used instead 
of copper, in order to avoid the occasional so- 
lution of the copper, and its precipitation on 
the zinc. 
IV. RESISTANCE OF ELECTRO- 
LYTES TO ELECTROLYTIC ACTION. 
—By interposing a platinum plate, and adding 
sulphuric acid to a pair of zinc and platinum 
plates, the current was completely stopped, 
by requiring it to decompose water, and evolve 
both its elements before it should pass. 'J he 
same effect almost was produced when two 
pairs of plates were used, and one interposed 
plate. But, in the case of three pairs of 
plates, a current was induced which passed an 
interposed platinum plate, but was stopped by 
two. The current originated by four pairs of 
plates was also obstructed by two interposed 
platinum plates. Five pairs of zinc and pla- 
tinum, with two interposed platinum plates, 
yielded a feeble current. Six voltaic plates, 
and four intervening platinum plates, induced 
a feeble current. The effects of retardation 
were altered when a variety was made in the 
nature of the liquid employed between the 
plates, niti ic acid appearing to increase the in- 
tensity of the current, muriatic acid transmit- 
ting a current more easily than pure sulphuric 
acid. Increasing the strength of the sulphuric 
acid caused no change in the effect. 
On varying the nature of the interposed 
plate, it was found that with one voltaic pair 
and one interposed zinc plate, as powerful a 
current was induced as if the interposed zinc 
plates was absent. With two amalgamated 
zinc plates there was still a powerful current, 
but some obstruction oocuied. On using 
three intermediate zinc plates, there was still 
further retardation, though a good current o/ 
electricity passed. Plates of copper seemed 
at first to occasion no obstruction, but after a 
few minutes the current almost entirely 
ceased. 
All these retarding effects exhibit most dis- 
tinctly the chemical relations and source of 
the current, and add to the evidence of the 
identity of the two. 
V- REMARKS ON THE VOLTAIC 
BAITERY. — The action of the battery is 
weakened by the formation during its activity 
of substances which may even tend to produce 
a countercurrent. In an experiment made by 
Faraday, the retardation of the current was 
obviously referable to the state of the film of 
fluid in contact with the zinc plate, the acid 
of the film being instantly neutralized by the 
oxide formed. 
A secoud cause of diminution in the force 
of the voltaic battery, is, that extraordinary 
state of the surfaces of the metals described by 
Ritter, which causes them to oppose the pas- 
sing current. 
The author directs, 1st. That w^eak and 
exhausted charges should never be used at the 
