in all possible ways, to assure himself that no error can arise from
its employment. He places in the course of one and the same current
a series of cells with electrodes of different sizes, some of them
plates of platinum, others merely platinum wires, and collects the
gas liberated on each distinct pair of electrodes. He finds the
quantity of gas to be the same for all. Thus he concludes that when
the same quantity of electricity is caused to pass through a series
of cells containing acidulated water, the electro-chemical action is
independent of the size of the electrodes.[3] He next proves that
variations in intensity do not interfere with this equality of
action. Whether his battery is charged with strong acid or with
weak; whether it consists of five pairs or of fifty pairs; in short,
whatever be its source, when the same current is sent through his
series of cells the same amount of decomposition takes place in all.
He next assures himself that the strength or weakness of his dilute
acid does not interfere with this law. Sending the same current
through a series of cells containing mixtures of sulphuric acid and
water of different strengths, he finds, however the proportion of
acid to water might vary, the same amount of gas to be collected in
all the cells. A crowd of facts of this character forced upon
Faraday's mind the conclusion that the amount of electro-chemical
decomposition depends, not upon the size of the electrodes, not upon
the intensity of the current, not upon the strength of the solution,
but solely upon the quantity of electricity which passes through the
cell. The quantity of electricity he concludes is proportional to
the amount of chemical action. On this law Faraday based the
construction of his celebrated Voltameter, or Measure of Voltaic
electricity.

But before he can apply this measure he must clear his ground of