Year: 1888

page_text: n
We, CARL LÜTCKE, Chemist, of 38-39 Dorotheenstrasse, Berlin and PAUL GEORGE,
Author, of 81 Ritter strasse Berlin Empire of Germany do hereby declare the nature of
our said Invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The object of this Invention is,
-
1. To construct or arrange a Galvanic element or battery with two fluids in which.
a porous receiver and the electrodes are arranged in such a manner that the diffused,
depolarizing, disturbing fluid can fall into a free space below the active electrode
surface and the porous cell in the fluid of the element without being able to mingle.
with the fluid of the element in a way that would produce disturbance.
2. The adaptation of an overflow pipe to the porous vessel by which the fluid
accumulated through endosmose on the negative electrode falls within the full element
into a lower space.
3. The application of a second, smaller negative electrode to the element or battery
as a secondary terminal in the lower space before mentioned for the purpose of
decomposing the disturbing sulphate of copper diffused towards the lower space.
It is well known that the "Meidinger" Battery is distinguished by the duration of
its uniform action, as also by being very convenient. It has however, the defect
of only giving weak currents with disproportionate dimensions. The reason of this
lies less in the selection of the exciting fluids than in the unfavorable arrangement of
the etectrodes which are, moreover, small. To remedy this defect we while retaining
the outer positive zinc electrode, arrange the negative copper electrode in such a
manner that we leave a lower space R quite free (Figures 1, 2 and 3 in the accom-
panying drawings) which otherwise served to receive it and we suspend the copper
electrode K opposite the zinc electrode Z and in such a manner that the negative
electrode which in this case has a larger surface than in the old system stands in a
porous cell A hanging from the cover and filled with a solution of sulphate of copper
and crystals and which porous cell may have a cylindrical shape as in Figure 1 or a
conical form as in Figures 2 and 3, its height being so calculated that it will not reach
down into the lower space R.

page_text: This porous cell A then serves instead of the well known glass globe or funnel for
receiving the depolarizing solution of copper and crystals.
By the alteration, the following advantages are obtained;
1. By substituting a porous receiver A for the glass funnel it becomes possible to
arrange an efficient negative electrode within it and the electric resistance of the
element is 5 to 10 times less.
2. By introducing this porous receiver containing the sulphate of copper in the
upper part the impurities of the zinc are prevented from coming in contact with
the porous cell since they find room in the clear space R.
3. By leaving the lower space. free, any of the copper solution, which may ho
diffused through the porous walls of the vessel A falls towards R owing to its greater
specific gravity within the outer exciting fluid where it is mostly decomposed by
coming in contact with the zinc deposit and thus the formation of large quantities of
impurities on the zinc electrodes is prevented.
Under certain circumstances we however, introduce into the space R another
smaller negative copper electrode E as a secondary terminal, which can be connected
at pleasure for a shorter or a longer time with the large copper electrode K by means
of an insulated wire d, in order also, if required, to consume by electric means the
sulphate precipitated towards R. This contrivance serves two purposes, if, for
instance, the small lower electrode E is connected with the zinc of the next element
to form a battery, this arrangement is available for weak currents" (Telegraphy,
Therapeutics &c.).
If however the large electrode K in the porous vessel A is connected, instead of the
small one, with the next element, then the battery is adapted for all purposes where
currents of greater intensity and constancy are required.
If the battery has been working for a long time and the volume of the fluid in the
porous vessel has, in consequence, increased on the negative copper electrode, a portion
can be emptied out, or a waste pipe is introduced into the porous vessel and serves
to conduct the superfluous copper solution into the space R or to the bottom, where it
can be decomposed at pleasure by the small secondary terminal or can be allowed to
run off with the concentrated salt solution in the outer vessel through the tube T.
In order to renew the element after working, the tube T serves, as already said, to
let off the fluid, a similar one is used at the same time for introducing fresh fluid sub-
sequently and can also be applied to the porous vessel A.
If conical cells A are used as in Figures 2 and 3, it is peculiar that the sulphate solution
does not penetrate laterally to such an extent into the outer fluid but owing to the
adhesion to the porous walls of the vessel, chiefly only at the lower point so that it
cannot come into disturbing contact with the zinc electrodes.
For the further improvement of the arrangement of the element a contrivance
has been introduced, the object of which is to prevent in a suitable manner while
the element is in activity, any impure particles detached from the outer zinc electrode
from settling on the porous cell containing the negative copper electrode. Of course
the cell might thus become easily coppered and would be destroyed if it took place to
a great extent. In order to prevent this there is introduced between the cell A and
the outer zinc Z a very permeable partition B suitably made of some stuff of loose
texture as shown by the dotted lines in Figures 1 and 2. If any particles of zinc
impurities are suspended in the outer zinc fluid and do not fall to the bottom, they
cannot however reach the porous cell but are retained by the permeable partition
between the cell and the zinc. Nevertheless there is sufficient space between the
zinc electrodė and the partition so that the real zinc deposit can reach unhindered the
space R.
The porous partition B can be so chosen that the inner resistance of the element is
only slightly increased. If, after long use, a more or less considerable quantity of
impurity has settled on the partition, the latter need only be simply taken out,
rinsed and reinserted. Thus the porous electrode-cell is completely preserved and can
be used for a long time.
If with this element the circular arrangement is adopted, the partition B, serving

page_text: to intercept the impurities presents a cylinder open at top and bottom which is
arranged like the inner porous cell, so that any diffused, depolarizing fluid as also the
zinc deposit, falls freely into the space R without being able to accumulate between
the porous cell and the zinc electrode.
If a flat or square arrangement of the element is adopted, the above mentioned
slime-catcher is constructed by stretching a piece of suitable stuff on a rectangular
frame, which is then inserted between the zinc Z and the porous vessel A.
A suitable material for the slime-catcher is afforded by coarse woollen or half-
woollen or hempen tissues, gauze, muslin, &c. and even fine platinised wire gauze,
where a slightly greater expense is of no object.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. A galvanic element or battery with two fluids, in which a porous receiver (A)
and the electrodes (K, Z) are arranged in such a manner that the diffused,
depolarizing, disturbing fluid can fall into a free space R below the active electrode
surface and the porous cell in the fluid of the element, without being able to
mingle with the fluid of the element in a way that would produce disturbance sub-
stantially as herein before described.
2. The adaptation of an overflow pipe r, to the porous vessel A named in Claim 1,
by which the fluid accumulated through endosemose on the negative electrode falls
into the lower space R, as set forth.
3. The application of a second, smaller, negative electrode E to the element,
claim 1, as a secondary terminal in the lower space R for the purpose of decomposing
the disturbing sulphate of copper diffused towards R.
Dated this 23rd day of June 1000.
H GARDNER,
166, Fleet Street, London,
Agent for the said C. Lutcke and P. George.