IMPROVEMENTS IN VOLTAIC BATTERIES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Robert Larchin at the Office of the
Commissioners of Patents on the 5th February 1883. Communicated to him
from Abroad by Leo Hartmann of St Petersburgh in the Empire of Russia
ROBERT LARCHIN of N° 4. Finsbury Circus in the County of Middlesex
"IMPROVEMENTS IN VOLTAIC BATTERIES [Communicated to him from Abroad
by Leo Hartmann of St Petersburgh in the Empire of Russia]
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This invention relates to the construction of voltaic batteries and the preparation
and application of their elements in such a manner as to render the electrical
production very uniform over long periods of time. For this purpose, zinc is
employed as the positive element, and silver as the negative element, the silver
being arranged in a manner which will presently be described, and a solution of
caustic potash or soda is employed as the exciting liquid. The zinc occupies the
middle of each cell and may be surrounded by a porous partition, the silver being
at the sides, not in one plate or mass, but in a subdivided form so as to present in
comparatively small space a large amount of surface with numerous interstices for
escape of the hydrogen. Thus in front of the walls of the cell is fixed a network
which may be of metal or of vegetable fibre coated with frosted silver, and between
this network and the cell wall, are placed a number of fragments of carbon which,
as well as the cell wall are also coated with frosted silver. The cell wall and net-
work, if metallic or of material partially conductive of electricity, and the carbon
fragments can be coated with the silver electrolytically. The vegetable fibre is
coated in the following manner. It is first immersed in a solution of gallic acid
then in a solution of-nitrate of silver. After being dried it is again immersed in a
solution containing grape sugar, tartaric acid and lime, and finally in a solution of
ammoniauret of silver. It is preferred to fix in the lower part of the cell a funnel
having a small mouth opening down to a space below the cell where the oxide of
zinc collects, the funnel forming nearly a complete separation between this oxide
and the elements above, and so reducing greatly the tendency to cross action by
polarisation. It is also preferred to cover the cell with glass to prevent as far as
possible access of carbonic acid to the exciting alkali, leaving however a small
passage for issue of the hydrogen generated. A number of cells may be grouped
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page_text: together in one box, these cells being insulated from one another if they are made
of metal. The cells may however be made of wood by dividing by partitions a
wooden box, all the wood employed being waterproofed by soaking it in paraffin
or other waterproofing material. Each cell is connected by a tube of glass or
other non-conducting material to an external supply reservoir, turning the ends of
the tubes all up to one level in the reservoir which when required is supplied with
distilled water. The lower parts of the cells below the funnels may-all-in like
manner be connected with a discharge reservoir from which the liquid containing
oxide of zinc nay, from time to time, be discharged. Each cell may however be
discharged separately by opening a passage at its bottom. When tubes are
employed as above described for communicating with the separate cells either for
supply or for discharge or for both, these tubes may conveniently be accommodated
in grooves in the partitions of the box,