A NEW OR IMPROVED GALVANIC ELEMENT
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for A NEW OR
IMPROVED GALVANIC ELEMENT a communication to me from abroad by Wirth
and Company of Frankfurt-on-Main Patent Agents acting as the Attorneys of
Alfred Dun also of Frankfurt to be as follows:-
"
•
This new galvanic element is principally intended for electric lighting purposes,
but it can, however, be advantageously used where a constant How and cheap
working are wanted.
The element consists of two cells, and differs essentially from those now used in
this viz. that both the outer and inner cells contain the same solution as exciting
fluid but in different degrees of strength; that in the cell for the carbon electrode.
is made very strong whilst that in the cell for the positive electrode is weak.
It has been ascertained that by the difference in the degree of strength in one
and the same solution all those conditions are fulfilled which are necessary for a
very constant battery and which, up to the present, it was believed could only be
obtained by the use of two different solutions in the two cells. The weak solution
serves as a dissolving moment for the positive electrode, whilst the strong solution
in combination with the carbon acts as a depolariser.
There are fluids, which even in a concentrated condition have only a very weak
depolarising effect, as, for instance, sulphuric acid. Yet by the use of such liquids
it is possible to obtain the required depolarising effect by the use of a larger surface.
in the carbon electrode, so that its surface be increased exactly in the inverse pro-
portion to the depolarising capability of the fluid in the carbon cell, in order to:
obtain complete depolarisation and a greater constancy of the element. The great
advantage to be obtained by the use of a similar solution for both cells of the
element, is, that in the working of the element the resulting product is pure, not
being contaminated by the liquid from the other cell. This pure product can be
used either directly for various industrial purposes, or by simple reactions converted
into a useful marketable.product.
Whilst the exhausted exciting liquid in the batteries heretofore used has been
quite worthless, being only separable by costly, and unprofitable methods; from the
exhausted exciting liquid of the present element, which has not been contaminated

page_text: by any heterogeneous bodies, a product is obtainable either directly or by some
simple and cheap method, the market value of which in most cases covers the cost of
maintenance of the element.
A further economical advantage is that the exhausted contents of the carbon cells
can, after being diluted by the addition of water, be employed for filling the cell
of the positive electrode so that it is only necessary to supply fresh exciting liquid
to the carbon cells.
By the use of similar solutions in both cells of the element a more constant
current is obtained, as the two similar solutions cannot act on each other chemically,
behaving in this respect very indifferently towards each other.
In the new element there can be used advantageously as exciting liquid in the
first case, such solutions as have in a concentrated condition great depolarising
power which effect the whole depolarization chemically without necessitating the
mechanical expedient of increased carbon surface.
It is preferred to use iron as the positive electrode, and as exciting liquid nitro-.
muriatic acid (aqua regis) the mixture consisting of muriatic and nitric acids. The
nitro-muriatic acid, as explained above, serves for filling both cells; for the carbon
cells it is used strong or very slightly diluted but for the other cells very diluted
(about 1/20th or at the most 1/10th).
The element containing in one cell carbon and concentrated nitro-muriatic acid
and in the other cell iron and dilute nitro-muriatic acid, remains constant for at
least 20 hours when employed 'for electric incandescent lighting.
After this period a mixture is formed in the positive electrode cells which
apparently consists of perchloride and protochloride of iron and also contains
undecomposed liquids. By heating this mixture, after being removed from the cells
a marketable perchloride of iron is obtained. The solution in the carbon cells
weakened partly by diffusion and partly by the work of depolarisation serves again
when diluted, for the preparation of the positive electrode cells, the carbon cell
being filled with fresh concentrated solution. Nitric acid in the above proportions
and degrees of strength may be employed instead of nitro-muriatic acid. Nitrate
of iron is, in this case, formed, which is a useful commercial product.
When nitric acid is employed zinc can be used with advantage instead of iron as
positive electrode. From this is obtained nitrate of zinc, which, if not used as
such can be converted by ammonia or carbonates of the alkalies into oxide of zinc
or carbonate of zinc and the corresponding nitrates.
If, now, as exciting fluid a solution is used, which in its concentrated condition
possesses little or no depolarising effect (as for instance muriatic or sulphuric acid)
then mechanical must wholly or partly take the place of chemical depolarization in
the element. For this purpose the carbon electrode must have as large a surface
as possible. This is obtained in various ways, for instance by the use of a hollow
double walled carbon electrode, perforated for the free circulation of the fluid the
inner hollow space being filled more or less with fragments of coke or carbon.
In this case the difference in the degrees of strength of the liquid in the cells is
not of so much importance as in the previous cases where the strength of the
solution in the carbon cell forms a-necessary condition of the depolarization.
Instead of carbon an electrode of platinum or any other similar conductor can be
used.

page_text: "
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "A NEW OR
IMPROVED GALVANIC ELEMENT (a communication to me from abroad by Wirth
and Company of Frankfort-on-Main, Patent Agents, acting as the attorneys of
Alfred Dun, also of Frankfort) and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
This new galvanic element is principally intended for electric lighting purposes,
but. it can, however, be advantageously used where a constant flow and cheap
working are wanted.
The element consists of two cells and differs essentially from those now used in
this respect viz:-that both the outer and inner cells contain the same solution as
exciting fluid but in different degrees of strength; that in the cell for the carbon
electrode is made very strong, whilst that in the cell for the positive electrode is
weak.
It has been ascertained that by the difference in the degrees of strength in one
and the same solution, all those conditions are fulfilled which are necessary for a
very constant battery and which, up to the present, it was believed could only be
obtained by the use of two different solutions in the two cells. The weak solution
serves as a dissolving agent for the positive electrode, whilst the strong solution in
combination with the carbon acts as a depolariser.
There are fluids, which even in a concentrated condition have only a very weak
depolarising effect, as, for instance, sulphuric acid. Yet by the use of such liquids
it is possible to obtain the required depolarising effect by the use of a larger surface
in the carbon electrode, so that its surface be increased exactly in the inverse pro-
portion to the depolarising capability of the fluid in the carbon cell, in order to
obtain complete depolarisation and a greater constancy of the element. The great
advantage to be obtained by the use of a similar solution for both cells of the
element, is, that in the working of the element the resulting product is pure, not
being contaminated by the liquid from the other cell. This pure product can be
used either directly for various industrial purposes, or by simple reactions converted
into a useful marketable product.
Whilst the exhausted exciting liquid in the batteries heretofore used has been
quite worthless (being only separable by costly, and unprofitable methods) from the
exhausted exciting liquid of the present element, which has not been contaminated
by any heterogenoeus bodies, a product is obtainable either directly or by some
simple and cheap method, the market value of which in most cases covers the cost
of maintenance of the element.
A further economical advantage is that the exhausted contents of the carbon cells
can after being diluted by the addition of water, be employed for filling the cell of
the positive electrode so that it is only necessary to supply fresh exciting liquid tọ
the carbon calle

page_text: By the use of similar solutions in both cells of the element a more constant
current is obtained, as the two similar solutions cannot act on each other chemically,
behaving in this respect very indifferently towards each other.
On this account no local action which on the one hand would cause a counter
current and on the other hand would increase the resistance of the element-takes 5
place. The interchange between the charges of the two cells consists only in this,
that they continuedly tend to equalize their strength, which does not however give
rise to any counter current nor increase the resistance of the element.
In the new element there can be used advantageously as exciting liquid in the
first case, such solutions as have in a concentrated condition great depolarizing
power which effect the whole depolarization chemically without necessitating the
mechanical expedient of increased carbon surface.
It is preferred to use iron as the positive electrode, and as exciting liquid nitro-
muriatic acid (aqua regis) consisting of the mixture of muriatic and nitric acids.
The nitro-muriatic acid as explained above, serves for filling both cells; for the
carbon cells it is used strong or very slightly diluted but for the other cells very
diluted (about 1/20th or at the most 1/10th).
The element containing in one cell carbon and concentrated nitro-muriatic acid
and in the other cell iron and dilute nitro-muriatic acid, remains constant for at
least 20 hours when employed for electric incandescent lighting.
After this period a mixture is formed in the positive electrode cells which
apparently consists of perchloride and protochloride of iron and also contains
undecomposed liquids. By heating this mixture, after being removed from the cells
a marketable perchloride of iron is obtained. The solution in the carbon cells
weakened partly by diffusion and partly by the work of depolarisation serves again
when diluted, for the preparation of the positive electrode cells, the carbon cell
being filled with fresh concentrated solution. Nitric acid in the above proportions
and degrees of strength may be employed instead of nitro-muriatic acid. Nitrate
of iron is, in this case, formned, which is a useful commercial product.
When nitric acid is employed zinc can be used with advantage instead of iron as
positive electrode. From this is obtained nitrate of zinc, which, if not used as
such can be converted by ammonia or carbonates of the alkalies into oxide of zinc
or carbonate of zinc and the corresponding nitrates.
If, now, as exciting fluid a solution is used, which in its concentrated condition
possesses little or no depolarising effect (as for instance muriatic or sulphuric acid)
then mechanical, must wholly or partly take the place of chemical depolarization in
the element. For this purpose the carbon electrode must have as large a surface
as possible. This is obtained in various ways for instance by the use of a hollow
double walled carbon electrode, perforated for the free circulation of the fluid, the
inner hollow space being filled more or less with fragments of coke or carbon.
In this case the difference in the degrees of strength of the liquid in the cells is
not of so much importance as in the previous cases where the strength of the
solution in the carbon cell forms a necessary condition of the depolarization.
Instead of carbon an electrode of platinum or any other similar conductor can be
used.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is
1st A galvanic element consisting of two cells, the electrodes of which are carbon,
platinum, or the like, and of metals or of compounds of metals, and in which the same
exciting liquid is employed in both cells, but in solution having different degrees of
concentration.
2nd A galvanic element consisting of two cells of which the one cell contains
carbon and concentrated or but slightly diluted nitro-muriatic acid (aqua regis)
whilst the other contains iron and nitro-muriatic acid (aqua regis) which has been
diluted at a degree of 11 20 to 1: 10 (more or less).

page_text: 3rd In a galvanic element as claimed in the first claim, the entire, or partial
compensation of the different degrees of concentration of the solutions by a pro-
portional enlargement of the surface of the carbon electrode.
All substantially in the manner and for the purpose as described.