a small model whose external dimensions are 160 x 100 x 90 millimeters.

"My invention," says the inventor, "is intended as an electric pile
capable of regeneration. The annexed Fig. 1 shows a vertical arrangement
of the apparatus, and Fig. 2 a horizontal one. In the latter, two
elements are represented superposed.

"My pile consists of a prism of retort carbon (a) covered on every side
with pure chloride of silver (b). The carbon thus prepared is immersed
in a solution of hydrate of potassium (KHO) or of hydrate of sodium
(NaHO), marking 1.30 to 1.45 by the Baume areometer, the solvent being
water.

"In the vicinity of the carbon is arranged the plate to be attacked--a
plate of zinc (c) of good quality. The surface of the electrodes, and
their distance apart, depends upon the effects that it is desired to
obtain, and is determined in accordance with the well known principles
of electro-kinetics.

"The chemical reactions that take place in this couple are multiple.
In contact with a sufficiently concentrated solution of hydrate of
potassium or sodium, the chloride of silver, especially if it has been
recently prepared, passes partially into the state of brown or black
oxide, so that the carbon becomes covered, after remaining sufficiently
long in the exciting liquid, with a mixture of chloride and oxide of
silver. When the circuit is closed, the chloride becomes reduced to a
spongy metallic state and adheres to the surface of the carbon. At the
same time the zinc passes, in the alkaline solution, into a state of
chloride and of soluble combination of zinc oxide and of alkali.