IMPROVEMENTS IN OBTAINING AND APPLY. ING ELECTRIC CURRENTS AND IN THE APPARATUS EMPLOYED THEREIN, PART OR PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE REPINING CERTAIN METALS, AND THE PRODUCTION OF METALLIC SOLUTIONS AND OF CERTAIN ACIDS
Year: 1852

page_text: PETRIE, of Woolwich, in the County of Kent, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Thirteenth day of No-
vember, One thousand eight hundred and fifty-two, in the sixteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Petrie, my exors, adñiors, and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said William Petrie, my
exors, adñiors, and assigns, or such others as I, the said William l'etric,
my exors, adors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, and in the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, and in all Her Majesty's Colonies and
Plantations abroad, my Invention of "IMPROVEMENTS IN OBTAINING AND APPLY.
ING ELECTRIC CURRENTS AND IN THE APPARATUS EMPLOYED THEREIN, PART OR PARTS
OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE REPINING CERTAIN METALS, AND
THE PRODUCTION OF METALLIC SOLUTIONS AND OF CERTAIN ACIDS;" in which said
Letters Patent is contained a proviso that I, the said William Petric, shall
cause a particular description of the nature of my said Invention, and in what

page_text: manner the same is to be performed, by an instrument in writing under my
hand and scal, to be enrolled in Her Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Petrie, do hereby declare the nature of my said Invention, and
in what manner the same is to be performed, to be fully ascertained and set
forth in and by the following description thereof, reference being had to the
Drawings hereunto annexed (that is to say):-
First, I use for several purposes, which will be herein-after mentioned,
what I term improved solution cells. The cell is for containing liquid, of
which it forms a solution, while it receives and transmits it, and is a vessel
preferred of a rectangular plan, if shallow, or cylindric, if deep, and may be
made of such material as glass or stoneware, Wedgwood ware, or platinum,
according to the nature of the process for which it is used. At the middle of
one of its broadest sides it has a lip A, Figures 1 & 2, which overhangs so
as to drop any overflowing liquid clear into another solution cell or receptacle,
placed with his edge suitably beneath the lip; a diaphragm or descending
tube B, fixed in the cell from the lip downwards, shuts off the passage of the
liquid in the cell to the lip, except at the bottom, where the diaphragm is
open. Any required loose matter C, such as sand, crystals of sulphate of
copper, or granulated alloy of gold and silver, according to circumstances, is
placed in the cell, and spread with a level surface, just so high that it shall be
covered with the liquid when the liquid overflows at the lip. The bottom of
the cell slopes towards the opening of the passage formed by the diaphragm
up to the lip, and loose half cylinders like drain tiles D, with the under
edges uneven, are placed on the bottom, so as to secure open passages for the
liquid from the further parts of the bottom to the opening of the diaphragm.
At the side opposite to the lip the inflowing liquid drops in, and thereunder,
but upon the top of the loose material, is placed a piece of flat material E, as
plate glass, to break the fall of liquid, and spread it out over the surface. I
modify these arrangements according to the purposes for which the cells are
used, that is to say, where the loose matter is in large grains or very porous,
as granulated metal, and the solution increases much in gravity as it passes
through, and where the cells are deep in proportion to their width and breadth,
the above-named arrangements for distributing and collecting the liquidatthe
upper and lower parts of the cells may be modified or dispensed with; and in
cases where the loose matter is coarse, or has to be removed from time to

page_text: time, as is the case with alloy of gold and silver, I use a sufficiently finely
perforated hottom F (Figure 5,) supported above the bottom of the cell, in
lieu of other drainage apparatus. And also in the above cases, but especially
in cases where the loose matter is entirely soluble, or nearly so, in the liquid
used, I use cells of the aforesaid description, but compound, that is, of the
shape of a box, trough, or cylinder, divided vertically by partitions either
across the cell or concentrically, with the liquid to enter at the centre, a
passage being left for the liquid to pass under every alternate partition and
over every intermediate partition, the powder or broken matter being dropped
in beween the partitions. By this arrangement, a liquid, as water, may be
converted into a strong solution of sulphate of copper, for instance, as it is
required to be drawn off without keeping a bulk of the solution in stock,
and without preparation or loss of time; I also case the cells with non-con-
ducting material to keep the heat in when the process of solution is of a
nature to be improved by it, as in dissolving metal by nitric acid. I prefer to
effect this by placing them in a case of wood or of earthenware, or of the latter,
or metal packed with charcoal or cinders, and a cover of similar materials;
where I use the terms series of solution cells, I mean several of them placed
side by side, each successively a little below the previous one, in such manner
that the liquid dropped into the highest shall flow through them all in suc-
cession.
I do not confine myself to the details above described, but I define the
essential nature of the improved solution cell to consist, (A) in a vessel con-
taining loose matter, and having liquid passing through it, and having some
change wrought in it thereby, and in the vessel being so constructed and
worked that the liquid having its level above the loose matter, so as to spread
freely to all parts of the surface, shall pass down every vertical line of the
loose matter from top to bottom with as nearly equal freedom or equal amount
of motion as may be, and shall flow off at a higher level than the lowest point
to which it descends in the loose matter; and (B) in a cell of the same
mature, but compound, that is, so divided by partitions that the liquid shall
pass alternately upwards and downwards once or oftener before flowing out;
and (C) in enclosing these cells with materials to preserve the elevation tem-
perature within them so far as the nature of the process in any case renders
this desirable. Further, I employ one of the said improved solution cells, or
a series of them, charged with such material as fine silicious sand, or calcined
pulverized flint, and I slowly transmit through them such turbid or discolored
acids or solutions, for the purposes of this Invention, as sulphuric acid con-
taining carbonaceous matter, to improve the liquid thereby.

page_text: Second, I obtain a saline solution for supplying galvanic apparatus where
it is stationary, and space is not an object, by the following use of the afore-
mentioned improved solution cells. I also employ these means in obtaining
nitric acid for the same purpose, and for general purposes; that is to say, I
cause water to drop slowly through a series of the said improved solution cells
of large size, according to convenience, but of shallow form, freely exposed to
the air, but protected from hot sunshine and from too much rain, and they are
nearly filled with such material as very fine silicious sand. I impregnate the
water partially with such an alkaline base, as potash, asmay be desired to form
the nitric salt by passing part of the stream of water through a solution cell
filled with the said base before the stream passes into the aforesaid solution
cells. At the depth of a few inches in the said sand, in all, except the lowest
two or three cells, and omitting alternate cells, or set of cells in the series, I
put a layer of offal from shambles, chopped fine and mixed with some of the
sand. Liquid flows off from the end of the series charged with a nitric salt,
which may be made to yield nitric acid in a separate state by the well-known
processes. The inflow of water should be regulated according to the size and
number of the cells, so as to cause the greatest produce of the saline solution
of sufficient strength to use or to be economically concentrated for use. I do
not confine myself to the details above described, nor to the employment of
an alkaline base in conducting the process, nor to the use of matter which is
nitrogenous; but I define the essential nature of the improved process to
consist in the use of the said solution cells charged with matter in a divided
form, such as will yield an acid by the process as decomposable nitrogenous
matter placed amongst finely divided solid matter, as sand, and with aqueous
liquid passing continually through the series of cells, or with liquid of the
same nature as the said matter, or containing matter of that nature, such as
sulphurous acid in solution, without adding to the sand the matter in a solid
form.
Third, I form solutions as (1) of acidulated muriate of ammonia, or (2)
sulphate of copper, or (3) nitrate of silver, by placing the matters, such as
muriate of ammonia, or sulphate of copper, coarsely pulverized, or the
granulated alloy of gold and silver used by refiners of gold, in one or in a
series of the said improved solution cells of a deep form and transmitting the
required liquid, as acidulated water, in the first and second case, or strong nitric
acid in the third case, in a continuous flow, as fast as it may be needed for use.
The solution may thence be made to flow into the highest cell of a gradient
battery, herein-after to be described, or solution cells, so used, may be placed at
an intermediate point in a gradient series of battery cells, so as to receive the

page_text: partially exhausted liquor from one battery cell and transmit it renovated into
another cell.
Fourth, I work a series of solution cells on the "differential system," where
it is desirable, as for instance, where part of the constituent materials of the
matter placed in the solution cells, whether the matter be placed there in large
pieces or in powder, is soluble by the action of the liquid used (with or without
other means, such as heat), and part less readily soluble, as in the case of
sulphate of copper and earthy matters mechanically mixed, and to be acted on
by water, or, as in the case of concreted carbon from gas retorts containing
iron or other matters soluble in the appropriate acids, and which it may be
desirable to extract before using the carbon as an element in a galvanic cell,
or for making an electrode for applying electricity to produce the electriclight,
for instance, or as in the cases of such metals alloyed! with such others in such
proportions and acted on by such acids as will leave the former and dissolve
the latter. Of this last class of cases I give an example in the course of the
following explanation of working the solution cells on the said differential
system-
I take a series of about six solution cells, Fig. 3, o a deep form, and which
may be made of thin Wedgwood ware or platinum, strengthened externally
with copper in a manner well known. I place them in a frame, H, I, Figs. 3
& 4, in a gradient series, so that the liquid supplied to the highest cell shall
drop into the next highest, and so on through the set. I take an alloy of one
part of gold which is to be refined with three parts of silver; I granulate the
alloy by pouring it into water as is practised by refiners; I place this granulated
alloy in the solution cells, and keep strong nitric acid, previously heated,
dropping from a tap in a reservoir into the uppermost cell. And the differen-
tial arrangement consists in adding at intervals a cell charged with fresh alloy
to the lower end of the series, and removing the uppermost cell G of the series,
and pushing the whole series thus constituted bodily upwards, so that each cell
shall occupy the position of the one which was previously next above it in the
series. For effecting this motion I fix two rails, H, I, and I place upon them
a series of beds or cradles K, consisting of cells or open square cases, in which
the solution cells A, &c., cau stand upright, while the cradles slide up the
incline, resting upon projections or wings I, attached in a sloping direction to
their sides to fit parallel to the face of the incline. The cradles are made to
press fairly against one another, so that when the lowest is pushed up the
incline that cradle propels those above it without upsetting them; there are
holes in the face of the incline at its lower part, in which to place a pin M to
keep the cradles from slipping down. To push the series upwards an empty

page_text: cradle N, with a slot in its front and bottom to admit the lever, or instead of
Na thick plate of metal is placed on the face of the incline, but below the
series of cradles with cells, and is forced gently upwards along the incline by
any suitable power, as a crow bar O, or a screw jack, when the apparatus is
large. The space between the rails II, I, under the cradles, may be enclosed
as a fluc, into which hot air may be made to pass if required to warm the cells.
When this mode of working is made continuous, the gold removed in the
uppermost cells successively has been acted on more thoroughly, and the
nitrate of silver flowing from the other end of the series has less acid left in it
than I believe could be accomplished in any other manner in the same time
and by one operation; and further, the ordinary use of weak acid to commence
the operation, lest the chemical action should pulverize the gold, is not necessary
in this process.
The same process, but with greater application of heat, and using oil of
vitriol, and dropping water at the same time into the cells at some point in the
series in lieu of nitric acid, may be applied to dissolve the silver, copper, and
many other metals, from the gold alloy, made up in the usual manner for being
acted on by vitriol.
Fifth, the gold resulting from the aforesaid process may be well washed by
placing the cells in a new series as they are taken from the aforesaid series, and
working the gold upwards in the new series by a similarly differential process,
using water to pass down through the series; by this means the gold is most
thoroughly washed, and yet the resulting nitrate of silver is not greatly diluted
thereby.
Sixth, I use improved kinds of syphons for moving the liquids used in the
varions processes of this Invention, especially for hot acids, from the carboys
or reservoirs in which the liquids are stored, or to or from or between the
vessels for heating or evaporating the liquids used or produced in working
this Invention, or to or from or between the individual cells or battery cells,
instead of other means of transmitting the liquids, such as overflow by lips.
I make the syphon (Figures 5 & 6) out of a piece of tube, with its
two legs P, Q, of equal length; one side R of the plane in which the
legs lie I call the front of the syphon, and the other side S, the back;
I bend the ends of the legs upwards in front at right angles to the lines,
joining homologous parts of the legs; the length of each bent part, T, U,
is about of the extreme height of each leg, and forms an angle of about
60° with them. It is desirable that the arc of these bends should be
as short as is consistent with the required facility of manufacture and
the free flow of the liquid. At the middle or highest part of the syphon
}

page_text: is an air chamber. The ends of the bent parts T and U are bent again
slightly downwards (as shewn at V, Figure 5), with the periphery of the
orifices cut in a plane parallel to the plane of the bent parts T and U. This
is to cause the last portions of liquid to be drained by the syphon when it is
inclined frontwards so far as to make the bent parts T lie flat on the bottom of
the vessel to be emptied. At the middle or highest part of the syphon is an
air chamber W, extending upwards in the plane of the legs, and not broader
from back to front that the general tube of the syphon, but extended to about
double that size laterally; the legs slope upwards from the curves or
shoulders p, q, to the air chamber, so that even if the syphon should be set a
little inclined to one side no air may lodge in the tube, but will rise into the
air chamber. From the junction of the air chamber with the tube a handle x
projects frontwards; its lower side is parallel to the bent parts and U of the
legs. The handle may be feather-edged for stiffness and lightness. To charge
the syphon it is held by the end of the handle with its back downwards and
horizontal,except that the air chamber should be..ather lower than the rest; in
this position it is lowered bodily into a vessel containing the liquid for which
it is to be used, and when thus lowered, so that the liquid enters freely at
either of the legs it will fill with the liquid,and should then be raised, keeping
the two orifices of the legs pretty nearly on the same level, while it is placed in
the position in which it is to be used, without raising the air chamber higher
than necessary above the orifices of the legs, until the leg for receiving the
liquid is well iminersed.
I do not confine myself to the details above described, but I define the
essential nature of the improvements to consist in a hand syphon having (A)
the ends of its legs bent so as to retain its charge while carried about and
placed across the side of a vessel so as to draw off its liquid; (13), a handle
projecting from the syphon, so that it can be held without wetting the hand
while the syphon is being immersed in a body of liquid in such a position
as to charge it; (C), an air chamber, as flat as the breadth of the tube of the
syphon, and fixed at the highest point of the syphon when it stands in action;
(1), a curve downwards at the extreme ends of the legs, so that the syphon
may be made to draw off the liquid to a less depth than the diameter of its
tube. This kind of syphon being used in any of the various processes of this
Invention.
Seventh, Inse a sort of hydraulic air pump to draw the charge into such
syphons as are fixtures or not readily moveable. The arrangement is as
follows: The ends of the syphon A, B, Figure 7, hang down into the tanks
C, D, and dip into liquid, in each enough to trap them; the syphon slopes up

page_text: from every part to one point, where the upper side of the tube has a very small
tube D projecting from it, and ascending to a certain height and descending
again through the top of an air-tight barrel E, and terminating in an open
orifice Fat the lowest part of the barrel,through the bottom of which is fixed
another small pipe G, which extends upwards in the barrel, so that its open
orifice stands so high that the liquid left below it in the barrel will be sufficient
safety to trap the end F of upper pipe 1) after a column of the liquid (which
we will assume to be water) shall have been drawn up into it as high as the
hydrostatic suction of the liquor in the syphon will draw it, when the inside
of the barrel is exposed to the atmospheric pressure, and the height to which
the upper pipe D ascends should be greater than the water can in any cir-
cumstances be drawn by the aforesaid suction,even when aided by the pressure
of water in the barrel up to its brim, and as far as the upper pipe D ascends
above the top of the barrel, so far does the lower pipe G descend below the
bottom of it, and terminates in a small hole; the sides of the barrel form a
cup K, K, by extending above the top, in which there is a large hole H, and
also a tube I, rising as nearly as high as the sides above the top of the barrel
and terminating in a small hole J. To charge the syphon its ends are first
trapped with liquid, then the barrel and the cups K, K, above it are filled with
water (poured through H), the hole at the bottom of the lower pipe G being
so small that there is time to plug up the large hole H, and to put the finger
on the small hole J before the water has descended to the bottoin of the cup;
the hydraulic suction of the column of water in the lower pipe G then draws
air from the syphon through the upper pipe D into the barrel, while the water
drains out of it, after which the finger and plug may be removed (from J and
H). If the syphon is not then fully charged, the operation is repeated until
it is.
The upper pipe D may be in separate parts just above its junction with the
syphon, and may be joined by a bit of vulcanized caoutchouc tube, in cases
where the liquid or heat in the syphon will not injure that material, or in
almost any case a similar junction may be effected at the highest point of the
upper pipe D.
If the upper pipe D is so large in its bore that the air drawn back out of
it by the suction of the liquor in the syphon is sufficient to form a bubble in
the syphon and impede its action, there should be anair chamber in the upper
pipe D where it joins the syphon.
These syphons described under the 6th and 7th heads may be made of any
suitable materials, such as lead for sulphuric acid, or glass, porcelain, or
platinum for nitric acid and for most other liquids.

page_text: Eighth, I use an improved galvanic battery, namely,-In the bottom of
a shallow square trough A, Figs: 8, 9, 10, & 11, preferred a stoneware
or Wedgwood ware, with a flat bottom fixed level, I lay a sheet of plate
glass, roughened and rubbed with plumbago over the upper surface, in
the way known, to make it a conducting surface, to be covered by electric
precipitation or coated with silver by known processes, so that nitrate of
silver will not injure it; or as an alternative, I use the bottom of the
trough itself instead of the glass plate. Across the trough at intervals I
place troughs of porous ware B, so formed as to rest across the sides of
the first or outer trough A, and yet for their bodies to extend beneath
the liquid containing nitrate of silver from the herein-before described solu-
tion cells, which liquid fills the outer trough; zine bars or sheets C,
properly amalgamated, are placed edgeways in the porous troughs, and
supported by pegs of wood passing through holes in it, and resting on the
sides of the porous troughs, or each zinc rests in the porous trough, and is
steadied on edge by the screw clamps D and wire E, which connects them
electrically with a clamp F, which is set fast on the side of the outer trough
of the same zink, or with another outer trough, according as the electric
circuit is desired; this said clamp F being electrically connected by varnished
platinum wire with the conducting bottom of its trough. Each of the porous
troughs have a lip at one end, which drops the liquid clear of the outer side
of the outer trough; the outer trough also has a lip which drops its liquid,
similarly. The body of the porous cell under the liquid in the outer trough is
made deepest at the end next the lip, and at this deepest part a diaphragm G
divides the porous trough crossways very nearly to the bottom of the cell. Or
I obtain the same effect by a descending tube connected with the lip.
The porous trough is glazed or varnished inside and out with wax, for
instance, so as to resist the solutions used at every part not covered by liquid
when it is in work, and at the end beyond the diaphragm under the liquid,
and at any other parts through which it is not desired that the electric current
should pass; this prevents unnecessary percolation below and efflorescence
above.
A number of these outer troughs, not less than six being preferred, so fitted
with
up
porous troughs, are placed in a gradient series, so that when liquid is
supplied to the highest outer trough, it will flow over the lips into the next
lower outer trough at the opposite sido to that on which its lip is, and so on
through the series, and when liquid is supplied to each of the porous troughs of
the highest outer trough, it will flow similarly into the several porous troughs
which are in the next lower outer trough, and so on through the series.

page_text: I drop nitrate of silver, obtained from the gold refining process already
described (under head 4th) into the highest outer trough, and dilute sulphuric
acid, preferred specific gravity 11 (or 1-125 when copper is being precipitated
instead of silver in the outer trough) into the porous troughs.
The electric circuit is so made as to pass through the troughs in series,
but the lower troughs in the series having more exhausted liquor should bo
worked slower, and, therefore, I connect two or more of such together, to
form the series. The purest silver will be deposited in the highest cells, and
where it ramifies it should be broken down from time to time to make it
spread as equally as possible over the bottom precipitating surface. The zinc
plates may be made thicker at those parts which wear quickest, or as the
lower edge of them wears away the plate is to be sunk lower into the trough
until it is lissolved as far as practicable.
Where I use the term trough form, or shallow form, I mean a form in which
the depth is less than one-third of the length, but I prefer it to be much less.
The term is used in distinction to the various forms generally employed under
the name of "cells," in which the greatest extension is generally in the
direction of the depth.
In cases where the solution in the outer trough is, such as sulphate of copper,
not of a nature to act on the metal it precipitates, a sheet of that metal may
be laid in the bottom of the trough instead of the glass sheet, or even when
the solution does act on the under side of the precipitated metal, as with
nitrate of silver, a sheet of it may be likewise used flat upon a level bottom,
but first carefully coated with bees-wax and turpentine, for instance, except
where it is to receive precipitation, and cemented to the outer trough all
around the edges, so that if any of the liquid should penetrate beneath it,
that portion of liquid will tend to remain there, to the exclusion of fresh
liquid, as soon as it becomes dense by saturation with the metallic plate.
In cases where a quicker action is desired I put slips of sheet metal similar
to that precipitated edge downwards into the outer trough between the porous
troughs and parallel to them, the slips of sheet metal being bent zig-zag
sufficiently to make them stand upright on the bottom. They are not so high
as quite to reach to the surface of the liquid. The general shape and pro-
portions which I think suitable for the battery are shewn in the Drawings
referred to; where desirable, such as for obtaining an extended porous surface
between the positive and negative elements, and for facility of manufacture,
I modify the aforesaid arrangements as follows:-The outer vessel is a shallow
circular pan, and if it be desired to keep it warm over a flue or in a sand bath
it may have a bottom smooth outside, of equable thickness, and very slightly

page_text: convex, of Wedgwood ware or stoneware; it has a lip for dropping the overflow
clear into another vessel. The porous vessel within it is of a similar shape but
smaller, and having a rim externally which rests on supporting bars laid across
the outer vessel and cut away so as to embrace a portion of the circumference
of the porous vessel. A bit of vulcanized caoutchouc tube passing through the
side of the porous vessel, as will be described under head 9th, and lying in the
lip of the outer vessel, extends so far as to drop its liquid into the porous vessel
of a simlar set of elements placed gradiently under it, and it has a bottom in it,
as will be herein-after described (R, Figure 12). The inner end of the tubo
extends to the centre or lowest part of the porous vessel, and its orifice is cut
aslant, so as to draw off the lowest stratum of liquid. A strip of sheet zink is
bent into a hoop a little smaller than the porous vessel in diameter, and is placed
therein, its ends not quite meeting, so as to leave an opening for the flexible
tube to pass through.
Ninth, instead of transmitting the liquid to or from a vessel or cell of a
battery by overflow through lips or by other known means, I often prefer to
make the communication by a bit of solid vulcanized caoutchouc tube drawn
through a smooth-sided hole, preferred circular, and of such size as to make a
tight fit in the trough or vessel; for instance, instead of having separate
supplies of liquid to each of the porous troughs, in one of the afore-mentioned
outer troughs I have the porous troughs made without lips for overflow, and
calling those ends of the troughs which are separated by the diaphragm the
outflow ends, and calling the opposite ends the inflow ends, I place the
porous troughs K, L, M, N, Fig. 12, in the outer trough H, as before, with
their similar ends alternately at opposite sides of the outer trough, and the
outflow end O of each one is connected below the level of the liquid in them
with the inflow end P of the adjacent trough, and the tube from the outflow
end of the last porous trough H in the outer trough may either lic in the
lip Q, and so pass to the inflow end of the first porous trough of the next outer
trough I, or the said tube may so communicate with a tight fit through holes
in the sides of the outer troughs H, I, themselves. Also these outer troughs may
be connected in a similar manner to transmit their own liquid by holes just at
te level of their intended overflow. The diaphragms may be dispensed with
by connecting the porous troughs with the tube at the lowest part of the
outflow end of the trough or by making the end of the tube to extend inside
to the lowest part. The caoutchouc tube which passes through the lip of the
final outer trough into a receiving vessel is passed through a tight-fitting hole
in a button R, which is slid nearly up to the lip of the outer trough; this
arrests the drops of liquid from the lip. When I use compound troughs or

page_text: cells of any kind of battery or electric apparatus, that is, cells divided by a
partition, through which it is desirable that liquid should pass but not.
electricity, beyond a limited or a minimum amount, 1 effect the object by:
drawing a bit of the said tube, of a size to fit tightly, through a hole in the
partition, the liquid passes through the tube but the electric current where of
low intensity is impeded in proportion to the smallness of the boro and the
length of the tube.
Tenth, where the liquid from which the precipitate is to be obtained is weak
or contains other elements which are liable to be partially acted on by the
electrolytic power, but which are not wanted so to be, such as nitric acid, or
small quantities ofother metals, I diminish this effect by using a very extended
precipitating surface with slow action, or by agitating the liquid, which I prefer
to do by small glass tubes, each being drawn to a point with a small hole in
its end immersed deep in the liquid in the battery cell, the other end of the
tube being connected flexibly by a bit of vulcanized caoutchouc tube with a
pipe which supplies a strong draught of air sufficient to inject the air forcibly
under the liquid. This aeration of the liquid also has the advantage of
reoxidizing any nitrous gas in solution which may be generated by the working
of the battery. Otherwise I use a shallow circular pan for the outer vessel of
the battery, and I fit up within it near the bottom a circular disc of the same
metal that is to be precipitated, the disc being fitted to a spindle turning on a
pivot in the vessel and working in a hole in a frame above, and kept revolving.
in alternate directions, the disc being thus so mounted as to revolve horizontally
and concentrically with the vessel. Two porous troughs with zinks in them
are placed one on each side of the spindle and across the vessel, partially in
its liquid, as herein-before described under head 8th, the liquids both of the
trough and vessel being constantly changed by any of the arrangeinents for
the purpose herein-before described. A gradient series of such galvanic
arrangements may be used to work the partially exhausted liquids from one
of the before-mentioned forms of battery. In all cases were not otherwise
expressed the battery elements described are to be electrically connected in
ways well understood by electricians to secure the proper electric action..
Eleventh, in using galvanic precipitation, as already described, for the
process of gold refining, or for precipitating from solutions containing nitrate
of silver, refined silver is obtained in the higher troughs of the battery, and the
resulting uitric liquor from the lowest trough, being partially deprived of its
silver, is used again in lieu of fresh nitric acid to dissolve more alloy, asalready
described, and when it has become too much charged with baser metals it is
passed through a spare battery like that through which it had already passed,

page_text: and therein it is made to deposit most of its metals in more or less purity;
this metallic deposit is then dissolved again in another portion of the said most
impure and used nitric solution, and the silver is obtained from this by ordinary
precipitation with metallic copper. The solution of metallic copper obtained
by this last operation or by the usual processes of refining by parting, whether
the process be conducted with sulphoric or with nitric acid, I work through a
similar battery to that and its modifications already described, so as to obtain
fine metallic copper, and in some cases other metals precipitated as the silver
was, and a solution of nitric or sulphuric acid from the outflow of the end:
of the series, and which may be concentrated by evaporation in the ordinary
modes.
Twelfth, for some batteries, such as those in which a cylinder of carbon
(A, Figure 13,) is used in a porous cell B, with a hollow cylinder of zink C,
externally, and concentric in the outer cell D, the central carbon is of
octagonal section from its lower end up to within a short distance of the top.
of the porous cell, thence it exten Is some way above the porous cell, circular
in section and much smaller in diameter, so that there is a broad shoulder
E, F,around it, the outward slope of which is upwards in the line of the radius
of the carbon, but the shoulder stands downwards around the carbon from the
side E at which the liquid is to overflow from the cell, so that liquid poured
upon the carbon would be carried partially round the shoulder and down on
the opposite side F. There is an annular cover G (perferred of cast glass).
I define annular to mean like a trough, with its length so bent circularly that its
two sides form the outer and inner circumference; this annular cover fits around
the circular part of the carbon, and rests within the top of the porous cell, the
bore of which is enlarged just at the top, so that the cover rests on a narrow
ledge H, where the large bore ends and the smaller bore begins. The liquid
in the porous cell overflows through a lip I, which is just so high that the
surface of the liquid is preserved above the under side of the annular cover G,
so as to "rap" it, and yes the liquid can flow from beneath the cover into the
lip, whence it falls on to the cover of the next porous cell B2 in the series.
The covers have each a rim (K) around their upper and outer edges, so that
the liquid dropped on them flows between the cover and the carbon. Thereis
a hole in the top of the cover, into which a conical end of a tube (of glass) fits,
and through which the gaseous matter evolved passes into a gas collector,
herein-after to be described. The connection with the carbon element is also
improved. It consists of a band L (Figure 14) of copper, fitting in a nearly
complete circle round the circular part of the carbon, and its ends N, M, short
and bent outwards; parallel through these passes a screw O, as close as may

page_text: be to the circle of the band I,and having a hemispherical or convex shoulder;
the tail of the screw enters a nut P, also hemispherical or convex towards the
band, and made in one piece with or soldered to a thinner band Q of copper,
which has a similar nut similarly attached at another part of it, with a similar
screw to clamp the zink element, by passing through a slit T, (Figure 13,) in
a metal strap U, connected therewith. This connection is protected from
injury by being smeared with a greasy composition, such as that which has been
used for the valve of the atmospheric railway, which neither melts by heat
nor hardens too much by cold, within such moderate limits as may occur in
working the battery. At the bottom of the outer cell D there is a hole V,
through which a short bit of vulcanized caoutchouc tube is tightly drawn; it
is also made thicker at its inner end to ensure its not slipping out, and in its
other end is fixed a bit of tight fitting glass tube, which is curved at its upper
end and hooks on the upper edge of the next cell in the gradient series, so as
to discharge its liquid therein, or else the tube may hook over the edge of a
trough, or be connected with its side by a bit of elastic tube; this trough
being supported parallel to the row of gradient cells, and so high as to prevent
liquid running from the cells into it,except when it is lowered for the purpose
of emptying them thereby. When this trough is used, the outer cells are made
with lips to overflow from one to another and are made catotenic, that is to say,
having their lower ends extending deeper than the zink and porous cell, which
are supported by a diaphragm, so broad as to fit across the interior of the outer
cell, and so high as to support the zink and porous cell. But in the case
shewn in Figure 13 these are only just supported above the hole V by al
a little
roller Y, of glass or wood, lying across the interior of the outer cell, and
having a contraction in its middle to let the liquid pass. When the said
trough arrangementcatotenic cells are used, they are not continuously supplied
with liquid, but it is filled by overflow from the highest cell, and is drawn off
when the lower or catotenic part has become filled with exhausted liquid,
which may be shewn by hollow glass balls made of such specific gravity as to
just float therein at various degrees of exhaustion in the liquid, the outer cells
being in that case made of glass. And in cases where the cells are not
gradient, but on a level, a small circular vessel may be substituted for the said
trough, the tubes being elastically connected with it as aforesaid at or near
its bottom, and then the lowering and tilting of this vessel will discharge the
liquid in all the cells, and they are simultaneously charged afresh by raising it
and pouring the fresh liquid into it.
Thirteenth, this last arrangement may be modified as follows for drawing
off from and supplying battery cells such liquids as become heavier as they.

page_text: become exhausted, especially where the cell is situated within another cell :-
A flexible syphon of plain vulcanized caoutchouc tube is fixed with one end at
the bottom of the cell (which is preferred to be catotenic) and the other end
dipping downoutside and turned up and fixed through the bottom of a move-
able vessel The syphon is charged and kept clear of gas, and ready to act
by using it alternately as a conduit to supply liquid poured into the vessel,
when raised above the level of the highest part of the arch of the syphon, and
as a syphon to draw off the exhausted liquid when the vessel is lowered to
such level as that to which it is desired to reduce the cell. A number of these
flexible tubes may be united in the bottom of one moveable vessel from a
number of battery cells on the same level. Those parts of the syphon which
are not needed to be flexible may be of rigid tube, as glass. The above modi-
fication of a syphon, described as head 13th, and which I call the syphono-
conduit arrangements, avoids the great objections commonly pertaining to
syphons used in batteries.
Fourteenth, for some batteries, such as those which are composed of a
series of cells formed by vertical cross partitions built into a horizontal trough,
and which work with two liquids, I provide means for changing the exhausted
liquids by forming the sides A, B, of the trough sloping inwards from near the
top of the sides down to the bottom (Fig. 15), with holes or channels D, E,
at the upper part of the slopes leading on one side from every cell containing
one sort of liquid, as dilute sulphuric acid, and on the other side from every
cell containing the other sort of liquid, as sulphate of copper; these holes
communicate with a channel F, G, either open or closed as a pipe on each
side, (the best form and proportions are shewa in Figure 15.) so that to charge
the trough it is placed on a horizontal table, and slightly inclined to one side
A, and one of the liquids is then poured into the channel of that side until
the liquid fills the cells so far as to cover the bottom of the channel, this
ensures an equal fulness in each cell; the trough is then similarly slightly
inclined to the opposite side B, and the other liquid similarly poured into that
chaunel G. To uncharge the trough it is blocked up slightly at one end, so
as to incline downwards towards the other end at which the said channels each
terminate in a lip, under which vessels are placed to catch the liquids which
are made to flow out thereat by inclining the trough first, so far to one side A
that the liquid in the cells which communicate with the channel G on the
opposite side of the trough shall rise nearly to the top part H of that side,
while a portion of the liquid in the other cell flows out at their own channel F.
The trough is then inclined to a yet greater angle on the opposite side B, but

page_text: not so far as to allow the remaining liquid in the cells which have been
partially emptied to overflow the top I of this side. A corresponding outflow
then takes place on this side, and the trough is thus inclined from side to side
cach time at a greater angle until it be emptied. Two or three inclinations
to each side will be sufficient if it be well proportioned. Solid conducting
arms K of biass are fixed to the external sides of the trough, which is pre-
ferred to be of wood, enclosing the trough itself, which is preferred to be of
Wedgwood ware, cemented into the wooden case. To these arms the plates,
for instance, the zink z, of one cell, and the copper or coppers of the next cell,
are attached with a nut and screw L; this is done in such manner and order,
as well as the cementing of the flat porous and non-porous partitions, and all
the other arrangements which are not new both in this and all other batteries
described herein, as is well known to electricians, to secure the proper and
desiredaction of the battery for a current either for quantitative or for energetic
results. I use projecting knobs on the acting surfaces of the metal plates to
prevent too close contact with the adjoining partitions of the battery; for
instance, I use rivets of gutta percha, or of sealing wax, or simple drops of
the same. The negative plates do not extend to the surface of their liquid,
except such parts of them as are varnished. I consider this form of battery
to be specially adapted to a proper application of electricity for medical
purposes, for which purpose I prefer to use two or three troughs containing
twenty pairs each, placed as compactly as possibly, and of the size shown in
the Drawing, and furnished with connecting clamps at the side to include in
the circuit any desired number of the plates, and using the sulphuricacid very
dilute, and both the liquids rather warm. Its action is quite different to the
ordinary coil apparatus; or to Pulvermacher's hydro-electric chain, and I
believe it to be generally far more efficacious. For medical purposes I also
use a new electrode pad to conduct the electricity to and from the body; it
consists of a piece of porous elastic material, such as spongio-piline, sewn to a
plate of perforated non-oxidizable metal, as platinum, which is connected with
the galvanic wires, and covered with a perforated non-conducting and water-
proof material, as gutta percha, extending around its sides. This is soaked in
the desired liquid, as water, and the moist porous surface applied to the skin
in the usual manner.
Fifteenth, there is a known and published form of battery in which a num-
ber of cells A, Figure 16, are made by vertical transverse divisions in one
trough of wood or porcelain, &c., or by independent cells, cylindric or other-
wise, placed in a trough, and cemented to or connected with its bottom or

page_text: sides, but generally its bottom, and the communication for liquid between
these cells A is effected by holes B, bored through the trough, and closed
channels or pipes C, made from the hole of one cell to the hole of another
in the substance, or upon the outside of the bottom or sides of the trough.
Now the improvement I make on such kinds of battery trough is to make
all such holes and channels with open ends, Figure 17, merely stoppered with
corks or plugs, for instance, and with similar open but stoppered ends at
every elbow in such passages; for instance, I continue the bore of the holes
(B) not only into, but straight through such passages, and if any other part of
the trough or framework lies in a line with such passages, I bore through it,
if the arrangement of the parts can be made to admit of this without affecting
the working of the battery, the object being to be able to clear out all such
holes and channels by removing the plugs at their external ends, and passing
a rod through them. And whereas most of these external channels in the
said batteries have been made in the bottom of the trough, and in a line with
one another, I prefer to make them in the side of the trough, Figure 17, and
the holes through the sides into the cells I bore in such positions as shall
make the external channels C connecting them to lie aslant to the side of the
battery, so that they can be looked through or cleaned out without the impe-
diment of one channel standing in the line of the bore of another. The
liquid being continuously introduced at the front cell in the trough, and
flowing out at the last, and the holes being so placed alternately at the surface
and at the bottom of the liquid in each cell as shall lead the liquid from
surface to bottom, or from bottom to surface, as it flows from cell to cell,
according as it becomes specifically heavier or lighter by the working of the.
battery; and for the latter class of liquids I adopt as an alternative plan the
making the communications between their cells by forming surface channels E,
Figure 18; that is, open channels in the thickness of the top edge of the
sides of the outer case, the channels being as it were dug so deep as to receive
and transmit the liquid before the cells become filled too full. The Figure 18
shows porous cells F,made of porous plates,cemented by couples between the
solid plates, which are represented by thicker lines.
Sixteenth, another improvement in obtaining electric currents consists in an
improved kind of magneto-electric machine or apparatus, for obtaining electric
currents by permanent magnets and mechanical motion. In a stand or frame
of wood two compound U-shaped permanent steel magnets A, N, A, S,
B, N, B, S, Figure 19, in the usual manner, with the usual means of adjust-
ment in such cases; one of these, A, N, A, S, is fixed flat on the board or
foundation of the frame, and the other, B, N, B, S, parallel to it, and so far

page_text: above it that the four poles stand in the corners of a perfect square, Figure 20.
At about four inches distant in front of these poles is a second similar set of
tivo compound magnets C, N, C, S, and D, N, D, S, (the latter of the two is
hid beneath the former in the view from above). Through the centres of the
squares formed by the poles, and parallel to the axes of the magnets, a strong
brass spindle E passes, and is supported on centre points at each end. Upon
this, and just between the two sets of magnetic poles, is tightly fixed a soft
iron cylinder F, with its axis coincident with that of the spindle, and having
each end branching into a fork G, H, and I, J, which are just so wide apart
as to come opposite the two poles, occupying a diagonal in each square, and
the cylinder Fis just so long that its forks, as nearly as may be, touch each
set of poles.
Around this forked iron cylinder is fixed a hollow reel or cylinder of brass,
with its axis coincident with that of the iron, and this hollow reel, which is
made so large that the iron cylinder can revolve in it without touching it,
there are set screws to adjust its position and to hold it steady, according to
the well known arrangements used in these kind of philosophical apparatus.
Around this reel is wound a quantity of insulated copper wire L, as closely
as may be, and its ends form the electrodes whence the current may be
obtained. To do this the iron cylinder is put into rapid rotation by means of
a drum K, fixed tight on the spindle, and driven by a strap passing over a
large wheel, in the manner usual in such cases. The proportions which I
prefer for this apparatus are represented in the Drawing. The poles of the
magnets are placed in such an order that each fork of the iron cylinder shall
have both its ends magnetized similarly in whatever position it be,and so that
the opposite forks shall always be magnetized contrarily the one to the other
and the cylinder will have its magnetism reversed four times in each revo
lution.
Another form in which I use magneto-electric machines is as follows:-O
a suitable stand I have a strong horizontal rod of brass turning in steady
bearings; into a groove along one side is sunk a small rod of soft iron,and
secured by undercutting the brass, or by the brass being cast to it. At short
intervals along the bar there are projecting rings made on it, and where the
iron passes them it extends outwards, so as to form part of them. Between
these rings is wound insulated copper wire closely around the brass rod, and
the ends of each coil of wire are connected with those of the next coil by holes
slanting through the diameter of the rod. The final ends terminate, one in
metallic connection with the rod, the other in a metallic ring insulated, bu
fixed on the rod,and thence the electric current can be conducted in the wel

page_text: known ways as required. Compound U-shaped permanent steel magnets are
fixed with their poles as close as may be to the rings of the rod without
touching it, so that each ring shall be between two different poles, fixed dia-
metrically opposite, the poles being in parallel lines on each side of the
revolving rod, and being alternately what are termed north and south. To
produce the current the rod is driven round in its bearings at a great velocity
by a large wheel with a strap passing over a barrel fixed on the rod. The rod
is steadied along its length by bearings fixed to the framework, and touching
the rings of the rod above and below, and as far around them as the poles of
the magnets will permit.
To either of these kinds of magneto-electric machines commutators may be
attached in ways well known, to make the electric current to move con-
tinuously in one direction where this is desirable, instead of having the reci-
procating current; and the insulated wire in either case may be either wound
around the revolving iron within it, so as to revolve with it, or it may be
wound around a hollow cylinder fixed concentric with the axis of revolution
of the iron within.
In the last-nained form of apparatus magnetic poles may be applied at four
points equidistant around the circumference of the rod, with the poles alter-
nating, instead of at two, and then there should be two rods of iron let into
the brass rod, one being on each side, so that there will be a double magnetic
action within the coils, and the magnetism will be reversed four times in each
revolution.
Seventeenth, for purposes herein-after to be described I use what I term a
draught cell; that is, a porous mass, or a collection of fragments of loose
material, through which the gaseous matter is made to pass, and generally
with liquid percolating through the mass at the same time, for the purpose of
effecting changes in the state of the gaseous and liquid matter used. This
species of apparatus is not new, nor is its application to effect changes in the
gases or liquids resulting from the working of galvanic batteries new ; but I
use it in an improved form and in improved modes of working, as follows:-
The draught cell, Figure 21, into which the gaseous matters are passed, is
composed of short cylinders like drain pipes, preferred of stoneware, but where
the heat is considerable I prefer other materials; Wedgwood ware of thin sub-
stance or well-glazed iron may be used. They are placed upright, the lower
end of one fitting into the upper end of another, and their lower edges Z are
slightly contracted and bevilled downwards, so as to shoot any liquid that may
drip down them clear of the sides of the next lower pipe. They are clothed
with brickwork B, where there is much heat, and are supported in any of the

page_text: usual modes, as around or within a large shaft, or between piers of brickwork
with beams orledges of brickwork under the enlarged upper ends of the cylin-
ders; into this draught cell is placed a quantity of grains of silicious sand, and
I prefer to place at or near the bottom of the cell a stratum of broken
pieces of coke; the grains of the said sand are of a rounded form and of
uniform size, as nearly as may be obtained, that is to say, it is sufficient
for practical purposes if the majority of its grains range between a largest
size, double the smallest thereof, but there is no positive limit, only the
greater advantage is gained as uniformity of size is obtained; the larger
sizes may be separated by sifting the sand through a perforated screen, and
the smaller sizes may either be screened out likewise or may be separated by
-water in apparatus, such as is used for washing gold dust from the earthy
matter in which it is formed. The positive size I define to be just so coarse
that when placed dry in its draught cell case, and air is drawn through it with
about the same pressure or power of suction as will be practically used when
it is in work, the quantity of air passing shall be double that which passes in
thesame circumstances, except that the liquor which is to be generally used in
descending through it at the rate at which it will do when in regular work.
This definition of size is to be understood to be that which is sufficiently nearly
the absolute best size, which, however, would vary, but only in some unim-
portant degree, according to the absolute amount of draught used, and the
nature of the liquid used, and other less important circumstances. It is to be
understood that the advantage in using the draught cell will be greater,
according as the grains are more nearly of the said best size. To avoid certain
difficulties and inconveniences in the usual modes of supporting the loose
matter C in the draught cell, and in letting a draught into it at its lower end
or at its middle parts, I support it on a truncated cone or mass (O, Figure 21)
of the said matter, which, however, may advantageously be made rather
coarser towards its outside; the draught can enter through the sides of the
cone into the middle part of the mass and pass upwards, or instead of the
sloping sides of the mass it may be retained by a prolongation of the sides of
the draught cell with holes (Q, Figures 23 and 24) in it slanting upwards from
the interior of the cell, and such a diameter proportioned to the effective
thickness of the side of the cell in which they are made, that the loose matter
'shall not drop out thereat, or they may be larger and with bits of pipe
attached, or with inverted troughs thrust through the holes transversely into
the draught cell (as shewn in the said Figures). The bottom of the cylinder
or case of the draught cell consists of a pan, preferred of stoneware, having a
small hole at its lower part protected from choking with the loose matter by a

page_text: cover of the same material perforated with fine holes or finely notched around
its lower edge. From this hole the liquid is carried by a trough of the samo
material into a suitable receiving vessel. Water is dropped in at the top of
the mass aud dispersed equally over its surface from a cistern D kept con-
stantly supplied by a tap, the bottom of the cistern being formed of a flat
horizontal plate or plates E, of very coarse porous pottery ware, its basis being
such as Wedgwood material, cross grooved at its under side like a wafer
stamp, but on a much larger scale. I define this improvement to consist in
inaking the under side of this porous bottom to have a number of prominences
made in the substance of the material, and each prominence sufficiently small
to admit a sufficient number to distribute the liquid with the requisite unifor-
mity, and yet not so small that the liquid might be drawn over by the syphon-
like action of the capillary attraction of the surface from one prominence to a
neighbouring one, which may happen to projecta little lower. The thickness
of the plate and the porosity of the ware are to be so adjusted that the
water shall drip through at the required rate when there is a few inches depth
of water over it, and so that the plate (E) shall not be less in its thickness
above the prominences than their own depth; or the water may be equally
dispersed by flushing it down intermittently and making it spread thereby; for
this purpose there is placed over the loose matter C a hydraulic racker F,
Figure 22, which is a horizontal trough having a longitudinal vertical division
G down its middle, and balanced upon its axis or spindle II, coincident with
the lower edge of the said division; the cross section of the trough is such
(as represented in the Figure), that when water fron the funnel or cistern d
(vertically over the axis of the trough), partially fills one side of it, then it
overbalances and suddenly throws that portion of water out by the longitudinal
orifice I, and the other side begins to fill. The water falls thence for a short
space, so as to splash and disperse, and to aid to this, a grating (K, Figure 22),
preferred of glass, stoneware, or glazed iron, is placed just above the loose
matter C of the draught cell. The rocker has a bar or bars N crossing
beneath it to prevent its rocking too far over on either side. The rocker and
other parts may be made of well-glazed iron or of Wedgwood ware; the bars
under the rockers should not be too hard, but made of wood, or else coated
with caoutchouc where the heat is not great. At the lower part of the column
of the draught cell the gaseous matter to be operated on or to operate with
is admitted by a circular flue or hollow case P fitting air-tight around the
opening (at (), or the openings (at Q), already mentioned, in fact the case l'
is by preference formed by an enlarged portion of the cylinder next below it
forming the sides of the draught cell, this enlargement or case having an

page_text: annular cover around the draught cell fastened air-tight over the case, in which
also there is a large circular aperture (Ror S or U, Figures 21 and 23), into
which a pipe is fitted through which the gaseous matter is drawn. At the
top of the draught cell the loose matter C does not fill the case by about two
feet the supply of liquid falls from the cistern (D) or d) before mentioned,
which is so adapted to the top of the draught cell as to close it air-tight, and
in the side of the draught cell, between this and the loose matter, there is an
aperture V, into which a pipe fits air-tight and leads to any means of producing
a continuous suction or inward draught of air from the top of the draught cell,
whereby the gaseous matter is drawn through the loose matter. This plan
has many important practical advantages over the plan of passing the gaseous
matter through the cell by pressure from the lower part. The said inward
draught may be produced by a variety of means, which may be chosen
according to the height of the cell, and the consequent power of draught
required, and according to the facilities of the locality, and various other cir-
cumstances, one of these means is by a known apparatus, whereby a draught
is produced by the falling of broken water or spray down a vertical shaft.
Eighteenth, the draught cell is fitted with a pipe, formed by preference of
lengths of stoneware tube, luted together, leading to an apparatus which I call
the collector; it is a pipe preferred of stoneware, and having a series of water
lute cups made on its upper surface; these cups are covered in the usual
manner, but the covers form the end of tubes (preferred of glass) which lead
severally to the vessels from which the nitrous gases are evolved, and by the
side of which the water lute pipe is placed, such as the solution cells herein-
before described, and to which the tubes are connected by their other ends
fitting by means of similar water lutes, or else by merely a close fit, into holes
in covers placed on the cells, and having sides fitting freely within the solution
cells, and extending downwards beneath the surface of the liquid therein, so
that the gas is confined in the cover, and the top of the cover extends beyond
the sides, so that it overlaps the rim of the solution cell and rests thereon.
Or similar covers may be used for any other vessels, or for battery cells
evolving gases to be drawn into the draught cell by means of the collector, or
the tubes from the collector are led to the covers herein-before described, for
the battery under head 12th; but in cases where the collector is applied to a
gradient series of vessels of any sort, I prefer to fix the collector aslant, so as
to be parallel to the gradient series, in which case I make the water tubes so
inclined to the axis of the pipe of the collector that they shall not be inclined
to the horizon; I also take small trapped pipe at the lowest part of the pipe
of the collector, so arranged that any liquid which may come into it may run

page_text: off thereby and not enter the junction with the other pipes connected with it,
and I have one of the water lute cups only partially covered as with a bit of
sheet glass, whereby I regulate the admission of external air when desired.
gases
Nineteenth, now I connect this collector with the sources of nitrogenous
gases as aforesaid, such as can be condensed by the joint action of oxygenous
gas and water, being connected by its main pipe with the lowest but one
aperture S of the aforesaid draught cell (Figure 23), and the suction of air
from the vent V above being established, and water being supplied to the top
just as fast as to effect the complete condensation of the nitrous gas, or faster
if a weaker form of nitric acid be desired, which flows out from below into
the receiving vessel. The action is as follows:-The nitrous gas, mixed ornot
with some atmospheric air, is drawn in at the middle aperture S, which may
be about twenty feet from the top of the draught cell, here it meets a slight
draught of atmospheric air from the lower aperture R; these become
intimately mixed and agitated by being drawn upwards through the loose
matte: C, and are absorbed by the enormous surface of aqueous liquid covering
the grains of loose matter, the liquid is presented to the gas in the most
favorable state for absorbing, being agitated and intermixed by falling over the
loose matter; moreover the surface action of the solid matter itself also con-
tributes to the effect which is that of oxidizing the nitrogenous gases; the liquid
which has passed from the top of the cell to near the middle orifice, thus
becomes strongly charged with nitric acid, and is but slightly disposed to take
and oxidize more; nitrogenous gas is made to take it more readily by meeting
with it in its densest condition fresh from its source, while on the other band
the last portions of nitrogenous gases which remain in the air before it leaves
the loose matter, and which gases would not readily be absorbed by liquid
charged even but slightly therewith, meet with the water in its freshest state.
By this orderly arrangement of the process, which arrangement I call the
differential system, far less if any gas is lost at the vent, and yet a far stronger
solution is obtained from below than could be done by other modes of arranging
an apparatus of the same condensing power, such as returning the liquor from
the bottom into the cistern again at top, and so making it pass frequently
through the cell, or by making the gaseous matter pass down in the same
direction as the liquid, or by making the gaseous matter pass alternately up
and down through a number of such vertical columns or draught cells in
succession. This differential system is applicable to many processes in the
arts under a vast variety of forms of apparatus, and with a vast variety of
materials to be operated on, such as solid matter containing extractivo
matters, or such as gases or heat, as in Sterling's patent air engine, but

page_text: this system appears to me not to have been hitherto generally understood or
appreciated; arrangements for developing it in the case of draught cells for
various purposes may have been occasionally made as it were accidentally, that
is, for convenience in other respects, but without that particular object in
view, and judging from the usual modes of working such apparatus the
benefit of the differential system therefore does not appear to have been
intentially entertained and published. I define the differential principle to be
that whereby two opposite charges, mutually dependent, are continuously or
alternately carried on and effected thoroughly between any matters, as solids,
liquids, gases, or.heat, in a line of continuous reciprocating motion, or of
simultaneousand contrary motions of any two such matters made to come from
opposite ends of the line and pass over or through one another from point to
point, so that the total changes to the extreme differences of condition at
the opposite ends shall be effected by an insensible variation in the character.
or degree of the change at cachi successive point in each direction, while the
circumstances of each point (or section of the line of motion) remain constant
both in respect of the character and degree of the changes taking place at it,
and the composition or temperature or constitution generally of any matter, if
any, which is fixed at each point, and of the solids, liquids, or gases as they
pass it. Charges are thus effected by the differential system thoroughly
instead of partially in each respect, or thoroughly in one respect only, as is the
case in effecting such changes by ordinary modes of bringing matters together
to act on oneanother, as by promiscuous mixing or shaking up the liquid and
the gas together, or by passing them in the same direction, or more than once
in opposite directions, through the draught cell. Now to proceed with the
changes effected in the aqueous liquid, which has fallen as low as the middle
aperture S, and is charged with nitric acid and a strong solution of such
nitrogenous compounds as nitrous gas, it falls lower towards the bottom R,
which is about eight feet below; and in the passage of the liquid the fresh
atmospheric air from below, acting on it among the loose matter, com-
pletes the oxidation of the nitrous gas, and the liquid runs out below as a
solution of nitric acid, as strong and as free from nitrous fumes as may
bc. In all cases in which I admit gases at two different levels into
draught cells I use a register to one or both, so as to modify as required
the relative proportions in which the gases enter. The different horizontal
sections of the draught cell may be constructed as separate draught cells,
placed not immediately under one another, but with the liquid and gases
conveyed from one to the other so as to effect the same order of action. Or
these different sections may be placed on the same level side by side, and the
.

page_text: liquid passing from the bottom of the first may be raised and passed into the
top of the second, and so on forwards, while the gases coming from the top of
the last may be led into the bottom of one before the last, and so on back.
wards; this is more complicated, but nevertheless each of these modifications
Iregard as essentially the same as the first-mentioned arrangement, that is, the
process is conducted differentially; but it is quite otherwise if the gases are
made to pass alternately up and down the cells in the last-named arrangement,
or if the liquid at the tops of each of them is not progressively stronger
through the series from the first cell or vent of the gases to the last or entrance
of them; the same may be said when any other liquids or gases are used in a
draught cell; the liquid supplied to the cistern at top may be the exhausted
nitric acid solution from a galvanic battery or other sources.
Twentieth, the differential mode of using a draught cell is also valuable for
other purposes than that already nained. I use it for preparing a liquor of
I sulphuric acid for batteries where they are stationary, and the saine apparatus
may be used for obtaining sulphuric acid of various strengths for other pur-
poses; thus I pass the sulphurous fumes from an ordinary sulphur furnace,
or other source, at about the temperature of boiling vitriol, into the middle
aperture S of the draught cell (Figure 21) already mentioned; and air, which
I prefer to have previously dried by drawing it amongst bits of quick-lime, or
by other known methods, is drawn in at the lower aperture R, which, in this
case, I prefer to have about six feet below the other aperture S. Steam comes
out along with the exhausted gases at the vent V, which I prefer to have about
sixty feet above the entrance of the hot gases, and strong acid flows ready
cooled from below. The drip of aqueous liquor from the top is to be regulated
so as to cool and aid the condensing power of the upper part of the draught
cell as much as possible without being so abundant as to overcome the eva-
porative power of the heat of the gases so far as to weaken the resulting acid
more than is required. The register or damper at the middle aperture affords
the means of regulating the supply of the gases in this as in every other case,
so that just so much may pass as the cell is capable of condensing. A small
quantity of nitric acid or nitrous gas may be used in the aqueous liquor above
to effect the combination more rapidly; in this I prefer to have the drauglit
cell above twenty feet high, above the entrance of the sulphurous gases. The
draught cell may be modified (Figure 23) for the purpose of obtaining the
advantages of conducting the chief part of the condensing process with cooler
gases, , that is, at considerably less than the boiling heat. For this purpose the
furnace gases are admitted at the orifice S, Figure 9, as before; but after they
haveascended sufficiently to evaporate the water from the descending acid, they
D

page_text: are led out of the draught cell by an aperture T, just below which the loose
matter terminates, and leaves a vacant space in the case of the cell, and just
above which there is placed a horizontal division Y to support the superiu-
cumbent loose matter, but to let the acid pass straight down; this acid is made
to fall equally over the aforesaid lower surface of loose matter (below T) by
any of the herein-before described means of diffusing the liquid at the top
surface of the draught cell; the furnace gases on passing out at the aforesaid
aperture Tare cooled, for instance, by the well-known contrivance of a worm
of lead or stoneware, or Wedgwood ware, the worm being so arranged as
regards its level that any acid condensed in it may flow along with the uncon-
densed gases through an inlet U into the upper part of the draught cell, just
above the division Y, thence they pass upwards, and are condensed as in the
previous case (Figure 21). In some cases, especially when the furnace
gases contain nitrous gas, it is desirable to use other air to concentrate
the acid; in this case cold air is drawn in at the lowest orifice (R,
Figure 23), as before; hot air (about 600° Fahr.) is drawn in at the next
orifice S, and on passing out at the next orifice T, charged with sulphuric
fumes and nitrous gas, it is turned into the furnace or into the pipe con-
veying the gases from the furnace, and all these gases combined and suitably
cooled, as before said, are led into the draught cell (at U) just above the
division (Y), whence they proceed as before. When nitrous gases are used,
the upper part of the draught cell may be much shorter than where they are
not used; 1 prefer 20 feet for the height. In all cases in which I use draught
cells I make their diameter according to the amount of work they have to do;
I prefer them to be from 4 inches to 30 inches.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim, -
First, tho employment of the improved solution cells, as herein-before
defined, in the process of making nitric acid, metallic solutions, or solutions
for supplying galvanic batteries.
Second, the particular mode of using the improved solution cells, con-
taining acid, as herein-before defined, for use in batteries, and for obtaining
nitric or sulphuric acid, and saline metallic solutions of an alkaline oxide of a
metal.
Third, the adaptation of solution cells to the continuously receiving the
out-flowing liquor from a battery cell, and to transmitting itin an altered'state
into another battery cell, as herein-before described.
Fourth, the employment, for the purposes of my Invention, of a series of
solution cells arranged and worked on the differential system, herein-before

page_text: described, and charged with solid matter, (consisting of a compound, part of
which is soluble by the liquid used, and part insoluble, or less readily soluble,)
so as to obtain a strong solution of the soluble part, and to obtain the insoluble
part as free from the soluble part as may be.
Fifth, the adaptation of solution cells, worked on the said differential
system herein-before explained, with suitable liquid, such as water, to wash or
remove any adhering liquid or soluble matter from luimps, pieces, or powder of
insoluble matter, for the purposes of my Invention,
Sixth, the employment of a hand syphon for the purposes of my
Invention, the syphon having the combination of the improvements herein-
before defined under the heads A and B, or A, B, and C, or A, B, and D, or 1
A, B, C, and D).
Seventh, the employment ofasyphon, having an apparatus attached, whereby
air may be drawn from it by the power of the descent of liquid (such as water)
made to pass through the apparatus; the said liquid not mixing with the liquid
drawn through the tube of the syphon itself, as herein-before described.
Eighth, (A), the combined use of the trough or shallow form, as herein-
before defined, for cells or vessels of a battery for galvanic apparatus, in which
two liquids are used, with provision for continuous supply and discharge
through a series of the vessels of that form. I also claim the production of
the efflux of the liquidat the furthest part from the influx, in galvanic vessels
used in the above combined arrangement. (B), the combination of the
trough or shallow form for the cells or vessels of a battery, with the arrange-
ment of more than one of such porous vessels in a single outer vessel. (C),
the cementing of a flat metal sheet in a horizontal bottom of a galvanic vessel
of the trough form aforesaid, in the manner herein-before described, to receive
precipitates where the liquid would act on the back of the said sheet. (D),
the employment of a durable glaze or varnish covering the non-immersed
parts of porous vessels used in galvanic arrangements. I also claim the
employment of the same over such iminersed parts as are not much needed to
transmit the electric current. (E), the gradient battery, that is, supplying
the liquid or liquids to a number of separate single or compound galvanic
vessels, by placing them in a series, each successively a little lower than the
other, so that the liquid supplied to the highest shall overflow into the next
lower one, and so on successively through the series, by means of a lip or
spout. (F), the use, in connection with the overflow lip or orifice, of a
descending tube or diaphragm open at the lower end, within such galvanic
vessel ascontains liquid which becomes specifically heavier while thegalvanic
action proceeds, so that the heaviest portion of the liquid shall flow away:

page_text: Nith, the employment of elastic tube drawn through a smooth-sided
hole without angles, and so small as to make a water-tight fit in the side (or
bottom) of a galvanic vessel in cases where a water-tight connection for a
flow of liquid is required, or where such water-tight connection exists inde-
pendently, but it is desired to impede "electrical" communication through
the orifice.
Tenth, the continuous agitation, or auration and agitation of the liquid
in galvanic batteries while they are in action, by the means herein-before
described.
Eleventh, the precipitating of silver, copper, aud such other metals as are
obtained in solution in the refining of gold and silver by electric deposition.
Twelfth, (A), the annular cover, as herein-before defined, to receive and
transmit througha tube the gases evolved from liquid in a battery cell, the cover
being trapped by the liquid, and having a part of the apparatus, as a carbon
element or a porous cell, passing through its hollow centre. (B), the combi-
nation of the said annular cover with a rim round its outer or inner edge, as
herein before described, on the negative element of a battery, to carry the fresh
liquid to one side of the cell, and with an overflow by a lip at the opposite side
of the cell. (C), the use of a connecting strap, having the following parts in
combination, which are herein-before described:-A circular band tightened
by a screw, having a convex shoulder and screwing into a convex nut, forming
one piece with the strap, which is distinct from the circular band, and has a
similar nut and screw at another part of it to connect it with the opposite
element. (I do not claim any of these parts separately.) (1), the use of
elastic tube drawn tightly into a hole in the bottom of a galvanic cell, and
connected with an inelastic tube, whereby the liquid will overflow into another
cell when at its proper level within its cell, or else whereby the liquid is
simultaneously drawn off from or supplied to a number of cells having similar
tubes so connected as to move up and down together. (E), the use in
batteries of the combination of more than one of the herein-before described
cells of the catotenic form, with the last-named mode of simultaneously drawing
off or supplying the liquid, or with the arrangement claimed next after this.
Thirteenth, the use of a flexible syphon, so fitted up as to ac at pleasure
alternately as a conduit to supply and a syphon to empty battery cases without
an aperture below the liquid in them.
Fourteenth, (A), the formation of the sides of a galvanic trough divided
transversely into cells of a particular form; that is, the upper part of the sides
being so inclined less outwards or more inwards than the lower part thereof,
and having channels so for.nel outside of the said upper part of the sides, and

page_text: communicating with the cells, as herein-before explained, that the battery may
be charged and uncharged, as herein-before described. (B), the electrode
pads, constructed as herein-before described, to apply the electric current to
organic matter.
Fifteenth, I claim in cases, as herein-before described, where the liquid
enters and leaves the cells by holes in the bottom or sides of a battery trough,
in which the cells are fixed, the employment of channels which connect these
holes, as herein-before described, in a direction slanting to the trough itself,
and having external holes merely plugged up, so that every part of the channel
can be cleaned as aforesaid. I also clain for transferring particular kind of
liquid, the use of the surface channels herein-before described.
Sixteenth, (A), Iclaim in magneto-electric machines the employment of the
insulated coils of the wire, in which the current is induced concentric with
the axis of motion; also, the use of the two soveral arrangements herein-
before described, including the combination of the said position of the
magnetic poles with the form of the iron in the first-described arrangement,
or its position and counterpoise with reference to the axis of revolution in the
second, and with its position and motion with relation to the magnets in either
case, by which arrangements parts of the revolving iron, or of the wire in
cases where that revolves, are closer to the axis of revolution, and arranged
more symmetrically around the axis than has been the case with arrangements
hitherto publicly used. And the use of a fixed or stationary coil of insulated
wire, in which the current is induced by the motion of the iron, while the per-
manent magnets are fixed or stationary.
Seventeenth, I claim for any of the purposes of this Invention the construc-
tion and use of a draught cell having the following improvements, combined or
otherwise, in so far as is herein-after stated:-(A), the forming the case or
inner lining of the draught cell of pipes, placed and shaped as herein-before
described. (B), the employment, for the loose matter within the cell, of pieces
of matter, solid or porous, according to certain rules, namely, solid material,
such as flint or quartz, in cases where the desired action is accomplished by the
exposure of an extensive surface of the liquid to the gaseous matter, and
where at the same time but little is required of the peculiar action of the solid
surface to effect the oxolation or combination of the fluid matters used; and
on the other hand, using porous materials, as pumice-stone or porous coke,
where there is needed little or no exposure of a surface of the liquid to the
gaseous matter, (for instance, where the liquid has already absorbed sufficient
oxygen from the air or gaseous matter, without chemically combining it,) but
where, co isequently, the desired action consists mainly or entirely of the

page_text: fore-mentioned peculiar combining action of the solid surface, and using à
mirture of the solid and porous material in proportion as these two actions are
needed. (C), the employment of grains or particles of sand or other loose
matter herein-before described, of a uniform size, as described. I also claim
their employment of a particular size, as herein-before described. (D), the
supporting the under part of the column of the said loose matters without bars
or perforated support, so as to admit the gaseous matter, as herein-before
described. (E), the employment of a cistern with a porous bottom, as herein-
before defined, for diffusing liquid equally over the loose matter in the draught
cell. (F), the employment of an hydraulic rocker for the same purpose. By
an hydraulic rocker I do not confine my meaning to the details herein-before
specified; but I mean an apparatus essentially of that kind; that is to say, a
receptacle into which the liquid is caused to pass, and which is so fashioned,
balanced, and arranged, that it shall have a reciprocating motion, and cause
intermittent flushes of liquid to fall from it. (G), the working of draught
cells on the differential system, as herein-before explained. (H), the employ-
mentof an intermediate entrance for gases into draught cells, above the lowest
entrance for gases, so as to obtain a second action in the same cell; also, the
modification for effecting the same purpose by using two separate draught
cells in combination, that is, passing the liquid from the bottom of one
into the top of another, through which a different gas or vapour is drawn.
I claim the above-named improvements, those marked A, B, C, D, E, F, and
H separately, and I claim B, C, and G in combination together.
Eighteenth, the employment of an apparatus, herein-before described under
the name of a collector, either to convey a gas or gases or vapour from any
series of vessels or orifices into a draught cell to condense it or them, or to
remove the gas from the cells of any battery to any other locality, to be either
used, condensed; or got rid of, or to remove the gas from the herein-before
described differential solution cells, to be either used, condensed, or got rid of.
Ninteenth, (A), the employment of draught cells worked on the differential
system, herein-before described, for the purpose of obtaining nitric acid from
nitrogenous gases from any source. (B), the employment of draught cells in
the process of refining gold or silver.
Twentieth, (A), the employment of draught cells to convert gascous com-
pounds of sulphur, as sulphurous acid gas, into sulphuric acid without the aid
of nitrous compounds or other substances acting similarly, and without the
combination of the usual chambers to aid the process. (13), the employment
of draught cells with aqueous liquor containing a small quantity of nitric acid,
or the nitrogenous.compounds, or nitrous or hyponitrous acid, or binoxide of

page_text: nitrogen, in combination with loose matter in the draught cell, composed of
grains of a particular size, as herein-before defined.
In witness whereof, 1, the said Willam Petric, have hereunto set my
hand and seal, this Thirteenth day of May, One thousand eight
hundred and fifty-three.
AND BE
REMEMBERED that on the Thirteenth day of May, in
the year of our Lord 1853, the aforesaid William Petric came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Thirteenth day of May, in the year of our Lord One
thousand eight bundred and fifty-three