suitable tension and intensity, there is deposited upon the anode a layer
of peroxide of lead varying in thickness with the intensity of the current,
and more or less rich in oxygen according to the intensity of the bath,
while the cathode is covered with a stratum of reduced lead. The liquid of
the bath supplies material for both deposits, while in galvanoplastic
operations the anode supplies it to the cathode. The principle of the
formation consists in introducing in an efficacious manner currents of a
great intensity, and thus abridging its duration.

Of two plates thus treated, the one becomes positive, and is covered with a
thick layer of peroxide of lead. On leaving the bath it undergoes various
preparations and several washings, and is then fit to be mounted along with
others to form an accumulator ready to be charged and to work. The second,
or negative, plate is covered with a thick sponge of lead. It is carefully
washed, preserved in water with exclusion of air, and submitted to a very
considerable pressure. After this operation it presents the appearance of
ordinary sheet lead, but though the physical porosity has disappeared, the
chemical porosity is intact, and this alone comes into play in
accumulators. When a negative plate is constructed in this manner, it is
ready to be combined with the positives to form an accumulator.

The inventor has sometimes put into the bath at the positive pole negative
plates prepared as just described. They become very easily peroxidized, but
they have the grave defect of requiring two preparations in place of one.
To secure an accumulator against any leakage from plate, the solderings and
the entire plates must be submerged in the liquid, so that nothing projects
up out of the acidulated water except two strong rods for making contact.
These rods are covered with an insulating varnish from their origin to
above the point where they issue from the liquid. The plates are of a
rectangular form (Fig. 1). They are sloped out at one corner, and as two