IMPROVEMENTS IN GALVANIC BATTERIES."
Year: 1880

page_text: LETTERS PATENT to Robert Chapman Anderson, of Woodstock Road, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
GALVANIC BATTERIES."
PROVISIONAL SPECIFICATION left by the said Robert Chapman Anderson
at the Office of the Commissioners of Patents on the 20th October 1880.
ROBERT CHAPMAN ANDERSON, of Woodstock Road, in the County of Middlesex,
Gentleman. IMPROVEMENTS IN GALVANIC BATTERIES."
"
This Invention relates to improvements in galvanic batteries, the object of the
improvements being to provide a battery which shall be both powerful and constant
without necessitating the employment (as at present) of free mineral acid in the
negative solution, whereby I avoid the emission of acid vapours and also the
wasteful action of such acids on the zinc element of the battery, thus promoting
constancy and economy of action in the battery, besides making the entire arrange-
ment more cleanly and convenient than hitherto.
In carrying out my improvements I employ the usual elements, such as carbon
and zinc, separated from each other by a porous pot or division in any well known
manner; the zinc may be acted upon by any of the usual solutions, but preferably
a solution of chloride of magnesium, as described in the Specification of former
Letters Patent granted to me, Number 3436, dated the Twenty sixth day of August,
One thousand eight hundred and seventy nine. For the negative solution I employ
chromo-chloride of potassium, to which I add water in sufficient quantity to produce
a saturated solution.
One method of preparing this salt is to mix boiling hydro-chloric acid with a
saturated solution of bichromate of potash in the proportion of about three parts of
bichromate of potash to four parts of hydrochloric acid, avoiding if possible the
evolution of chlorine; the salt is then deposited in crystals on the solution
cooling.
I however prefer the following process:-
To about one and a half parts of bichromate of potash in crystals I preferably
atan, the solution thus formed is then heated to

page_text: boiling point, and while at this temperature two parts of ordinary spirits of salt of
commerce or muriatic acid are added, and the solution being again brought to
boiling point is evaporated to as great a density as it can conveniently be brought
to without chlorine being evolved, and being then cooled forms the above named
salt.
Should, however, chlorine be evolved during the operation the process should
be immediately stopped, as the resulting salt is not only of less energy when used
in batteries, but assumes a form less dense and compact by reason of the long and
slender needles into which the salt crystallizes.
Or I may employ a somewhat similar salt, but one which does not give such
good and lasting results, and which may be produced by treating bichromate of
potash with sulphuric acid in a manner similar to that herein before described when
using hydrochloric acid.

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 20th April 1881.
ROBERT CHAPMAN ANDERSON, of Woodstock Road, in the County of Middlesex,
› Gentleman. "IMPROVEMENTS IN GALVANIC BATTERIES."
This Invention relates to improvements in galvanic batteries, the object of the
improvements being to provide a battery which shall be both powerful and constant
without necessitating the employmont (as at present) of free mineral acid in the
negative solution, whereby the emission of acid vapours, and also the wasteful
action of such acids on the zinc element of the battery, are both considerably
modified, thus promoting constancy and economy of action in the battery,
besides making the entire arrangement more cleanly and convenient than
hitherto.
In carrying out my improvements I employ the usual elements, such as carbon
and zinc, separated from each other by a porous pot or division in any well known
manner; the zinc may be acted upon by any of the usual solutions, but preferably
a solution of chloride of magnesium, as described in the Specification of former
Letters Patent granted to me, Number 3436, dated the Twenty sixth day of August,
One thousand eight hundred and seventy nine. For the negative solution I employ
chromo-chloride of potassium, to which salt I add water in sufficient quantity to
produce a saturated solution.
One method of preparing this salt is to mix hot or boiling hydro chloric acid with
a hot or boiling saturated solution of bichromate of potash in the proportion of about
three parts by measure of bichromate of potash in crystals to about four parts by
measure of hydrochloric acid, avoiding if possible the evolution of chlorine; the
salt is then deposited in crystals on the solution cooling.
I however prefer the following process:―
To about one and a half parts by measure of bichromate of potash in crystals I
add a suitable quantity of water; the solution thus formed is then heated to
boiling point, and while at this temperature from two to three parts by measure of
ordinary spirits of salt of commerce or muriatic acid are added, and the solution
being again brought to boiling point is evaporated to the density at which it will
when cool form a firm and solid salt, and this density can easily be ascertained by
allowing a drop of the solution to fall on a cool surface, when if sufficiently dense
it will quickly form into the solid salt. The proportion of water added as above
mentioned should in all cases be such that the operation may be carried out without
chlorine being evolved.
Should however chlorine be evolved during the operation the process should be
immediately stopped, as the resulting salt is not only of less energy when used in
batteries, but assumes a form less dense and compact by reason of the long and
slender needles into which the salt crystallizes.
A somewhat similar salt, but one which does not give such good and lasting
results, may be produced by treating bichromate of potash with sulphuric acid in
a manner similar to that herein before described when using hydrochloric acid, but
I have found by experiment that such salt in solution when in batteries rapidly
loses its strength, even although the battery has not been worked.
Having thus described the nature of my said Invention, and the best means with
which I am acquainted for carrying the same into effect, what I claim and intend
to be protected by the herein in part recited Letters Patent is,―

page_text: The employment for the negative element of a galvanic battery of chromo chloride
of potassium, as and for the purposes herein before described.
In witness whereof, I, the said Robert Chapman Anderson, have hereto
set my hand and seal, this Nineteenth day of April, in the year of our Lord
One thousand eight hundred and eighty one.
Witness,
G. F. REDFERN,
4, South St.,
Finsbury,
London.
R. C. ANDERSON. (L.S.)