IMPROVEMENTS IN GALVANIC BATTERIES
Year: 1879

page_text: LETTERS PATENT
to Robert Chapman, Anderson, of Woodgreen, in the
County of Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS
IN GALVANIC BATTERIES."
Sealed the 18th November 1879; and dated the 26th August 1879.
PROVISIONAL SPECIFICATION left by the said Robert Chapman Anderson
at the Office of the Commissioners of Patents on the 26th August 1879.
ROBERT CHAPMAN ANDERSON, of Woodgreen, in the County of Middlesex, Civil
Engineer. "IMPROVEMENTS IN GALVANIC BATTERIES."
This Invention relates to improvements in galvanic batteries, the object of the
improvements being to equalize the action and maintain the power and constancy
of such batteries, and at the same time to avoid the production of the noxious and
deleterious fumes or emanations usually emitted from certain batteries, more par-
ticularly those generally employed in producing the electric light.
In carrying out my improvements I employ the ordinary positive and negative
elements, such as zinc and carbon, the former of which may be acted upon by any
suitable acid, say, for example, sulphuric or muriatic acid or a salt of an acid. But
for the latter or negative element I employ oxalic acid in combination with a.
solution of bichromate of potash to which I add a suitable acid or a salt of an acid,
the proportions naturally varying according to the strength of the battery required.
It will be understood that these positive and negative solutions may be employed
either mixed together as a one fluid battery, or separately, by means of a porous
pot dividing them as a two fluid battery.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Chapman Anderson in the Great Seal Patent Office on
the 26th February 1880.
ROBERT CHAPMAN ANDERSON, of Wood Green, in the County of Middlesex,
Civil Engineer. "IMPROVEMENTS IN GALVANIC BATTERIES."
This Invention relates to improvements in galvanic batteries, the object of the
improvements being to equalize, the action and maintain the power and constancy
of such batteries, and at the same time to avoid the production of the noxious
and deleterious fumes or emanations usually emitted from certain batteries, more
particularly those generally employed in producing the electric light.
In carrying out my improvements I employ the ordinary positive and negative
elements, such as zinc and carbon, the former of which may be acted upon by any
suitable acid, say, for example, sulphuric or muriatic acid or a salt of an acid. But
for the latter or negative element I employ oxalic acid in combination with a
solution of bichromate of potash to which I add a suitable acid or a salt of an acid,
the proportion naturally varying according to the strength of the battery required.
It will be understood that these positive and negative solutions may be employed
either mixed together as a one fluid battery or separately, by means of a porous
pot dividing them as a two fluid battery.
I will now proceed to more particularly describe the best means with which I
am acquainted for carrying out my Invention, reference being had to the accom-
panying Drawing, which represents a sectional elevation of a battery cell according
to my Invention.
In a two fluid battery I employ, as herein before described, the ordinary zinc and
carbon elements z, c, which are separated by a porous pot A or other device, one of
the fluids being placed in the porous pot A or other device, and the other fluid in
a jar B on the bottom of which the porous pot A rests.
I use preferably a saturated solution either of sulphate of magnesia or of muriate
of magnesia as the exciting agent for the zinc or positive element, and oxalate of
chromium and potash in combination with free bichromate of potash and muriatic
acid, or a muriate or a chloride for the carbon or negative element.
Oxalate of chromium and potash may be formed by neutralizing a solution of
bichromate of potash with oxalic acid until effervescence ceases, or by mixing, a
solution of bichromate of potash with an oxalate, whereby either with or without
the assistance of acid for dissolving the said oxalate, oxalate of chromium alone or
a compound oxalate containing chromium is formed by the superior affinity of
oxalic acid for chromium 'over almost any other base or salt.
The negative portion of the cell may be charged in various ways, as for example,
by placing in the muriatic acid oxalic acid or an oxalate, and adding bichromate
of potash, whereby oxalate. of chromium is more or less quickly formed in the
cell, or oxalic acid may be formed in the solution itself in any convenient manner,
as for example, by the introduction of nitric acid with any organic substance, such
as sugar or starch, and as oxalic acid is formed it will combine with the chromium
and form the desired oxalate.
Another but more indirect method is to charge the cell containing the zinc with
a saturated solution either of oxalic acid or of an oxalate, the negative solution at

page_text: starting being quite free of oxalic acid or oxalate, the two solutions will then meet
in the porous walls of the inner cell, and oxalate of chromium will gradually form
and permeate the negative solution.
But the mode which I have found it advantageous to adopt in practice is to add
oxalic acid to a saturated solution of bichromate of potash (with free crystals of
bichromate of potash in addition) until the whole is completely neutralized, where-
upon considerable concentration will take place, and the oxalate of chromium and
potash will be precipitated as a purple salt of the consistency and granular appear-
ance of damp sand; a sufficient quantity of this salt is then placed in the bottom of
the carbon cell, together with about an equal quantity of crystals of bichromate of
potash, and a suitable acid (preferably muriatic acid) more or less diluted is then
added. I usually employ in the negative solution equal quantities of acid and
water, whereby the emanations of chlorine which a large proportion of acid would
be sure to produce are almost entirely avoided, but when I use a greater proportion
of acid or pure acid itself, then I allay and prevent the emanation of fumes of
chlorine by spreading a thin layer of flour of sulphur on the surface of the
solution.
Instead of dropping the crystals (or other agents) loosely into the cell containing
the negative solution as has hitherto been generally the practice, I have found it
convenient in some cases to enclose the crystals of bichromate of potash (or other
agent) in an adjustable glass tube C open at the top, and having a bottom D of
perforated platinum or of platinum wire gauze (or the tube itself may be perforated
either at the bottom or sides, or both), and I immerse such tube in the negative
solution to a greater or less depth, the greater the depth of immersion of the tube
the stronger the power of the battery, as more crystals are then exposed to the
action of the solution. In this way by adjusting the depth to which. I immerse
the tube the strength of the battery may be regulated, and by giving a funnel
shape to the upper end of the tube 1 increase its capacity, and can thereby store
sufficient bichromate (or other agent) to automatically feed the solution to
exhaustion.
For a one fluid battery I make use of the hereinbefore described solution
surrounding the negative element as a solution common to both zinc and carbon,
by this means doing away with the porous pot and the separate exciting acid for
the zinc element, whereby the action of the battery although of much shorter
duration than in the hereinbefore described two fluid battery will be rendered
much more intense and the internal resistance of the cell will be less.
It will be understood that the two fluid form of battery is that which I employ
where great constancy combined with a certain degree of power extending over a
considerable period of time is required, as for example, for telegraph work, the
ringing of electric bells, and (where used in a sufficient number of cells) for the
driving of electro-motors and the production of the electric light.
On the other hand the one fluid form of battery may be used with advantage
for purposes where a short, steady, and powerful action is required.
Having thus described the nature of my said Invention and the best means with
which I am acquainted for carrying the same into effect, I wish it to be under-
stood that I do not confine myself to the precise details herein laid down as the
same may be varied without departing from the principle of my Invention, but
what I claim is,―
Firstly. The employment in galvanic batteries of oxalic acid in presence of a
solution of bichromate of potash, or a solution of oxide of chromium, or of chromic
acid, or of a soluble base or salt containing oxide of chromium or chromic acid, as
bereinbefore described.
Secondly. The employment of a solution of oxalic acid or of a salt containing
oxalic acid, or of a salt of magnesia as an exciting agent for the zinc or positive
element, where the solution surrounding the carbon or negative element contains
oxide of chromium or chromic acid, either alone or in combination with a base or
salt, as for example, bichromate of potash, as hereinbefore described.

page_text: Thirdly. The employment of flour of sulphur for allaying and preventing the
emanations of chlorine in galvanic batteries, as herein before described.
In witness whereof, I, the said Robert Chapman Anderson, have hereto set
my hand and seal, this Twenty fifth day of February, in the year of our
Lord One thousand eight hundred and eighty.
Witness,
G. F. REDFERN,.
Patent Agent,
4, South Street,
Finsbury.
R. C. ANDERSON. (L.S.)