IMPROVE- MENTS IN THE DECOMPOSITION OF SALINE AND OTHER SUBSTANCES, AND IN SEPARATING THEIR COMPONENT PARTS, OR SOME OF THEM, PROM EACH OTHER; ALSO IN THE FORMING OF CERTAIN COMPOUNDS OR COMBINATIONS OF SUBSTANCES; AND ALSO IN THE SEPA- RATING OF METALS FROM EACH OTHER, AND IN FREEING THEM FROM IMPURITIES
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WATT, of Kennington, in the County of Surrey, Chemist, 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 Twenty-fifth day of
September, One thousand eight hundred and fifty-one, in the fifteenth year
of Her reign, did, for Herself, Her heirs and successors, give and grant 'unto
me, the said Charles Watt, my exors, adññiors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Charles Watt,
my exors, admiors, and assigns, or such others as I, the said Charles Watt,
my exors, adñiors, 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, my Invention of "IMPROVE-
MENTS IN THE DECOMPOSITION OF SALINE AND OTHER SUBSTANCES, AND IN SEPARATING
THEIR COMPONENT PARTS, OR SOME OF THEM, PROM EACH OTHER; ALSO IN THE FORMING
OF CERTAIN COMPOUNDS OR COMBINATIONS OF SUBSTANCES; AND ALSO IN THE SEPA-
RATING OF METALS FROM EACH OTHER, AND IN FREEING THEM FROM IMPURITIES;" in
which said Letters Patent is contained a proviso, that I, the said Charles
Watt, shall cause a particular description of the nature of my said Invention,
and in what manner the same is to be performed, by an instrument in writing
under my hand and seal, to be enrolled in Her Majesty's High Court of
•

page_text: Chancery within six calendar months next and immediately after the date
of the said in part recited 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
Charles Watt, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
This Invention consists, firstly, of improvements in decomposing of saline
and other substances, an in separating their component parts, or some of
them, from each other.
Nextly, of improvements in forming of certain compounds or combinations
of substances.
And, lastly, of improvements in the separation of metals from each other,
and in freeing them from impurities.
I employ the decomposing power of electricity, by means of what are
usually termed currents of electricity, in carrying out my Invention, and I
wish it to be distinctly understood that such currents may be produced in
any manner which may be found most economical and convenient.
It may be as well, previously to describing this Invention in detail, to prevent
useless repetition, to render the descriptions more simple and as free as possible
from technicalities, to state that electricians term binary compounds electro-
lytes. Thus, chloride of soda (common salt) is an electrolyte, being composed
of an anion with a cathion, the place at which the anion is eliminated being
denominated the anode, and the place at which the oathion is eliminated being
denominated the cathode. At the anode, chlorine, oxygen, and the acids are
eliminated, and at the cathode hydrogen and the metals are eliminated. Thus,
in the decomposition by a current or currents of electricity of chloride of
sodium dissolved in water, chlorine is evolved at the anode, and sodium at the
cathode; but, as sodium cannot exist under such circumstances, immediately
after its elimination it. decomposes part of the water in contact with it,
hydrogen being evolved, and the soda (scientifically termed hydrated oxide of
sodium) formed by the oxydation of the sodium being dissolved in the residue
of the water.
The first part of my Invention consists of decomposing, by the
agency of
electricity, saline or other substances in solution, placed in a vessel, divided
into two or more parts or compartments, by a partition or partitions composed
of porous material. One of the component parts of a saline substance to be.

page_text: decomposed is eliminated in one cell or compartment of the divided vessel,
and the other of the elements is eliminated in the other compartiment or com-
partments; the porous partition or partitions having the effect of keeping the
eliminated substances separate from each other during the continuance of the
process, and until the products can be removed from the vessel. . And for the
purpose of facilitating the decomposition, I heat the contents of the vessel in
any convenient manner. The electrical intensity required for this part of the
Invention will be equal at least to what would be supplied. by six cells of
Daniell's constant battery. For the purpose of performing this part of my In-
vention, I prefer to use vessels, such as shewn in Figures 1 and 3 of the said
Drawings hereunto annexed. One of these vessels is furnished with a single
porous partition separating it into two compartments; Figure 1 being a vertical
transverse section of the vessel; and Figure 2, a side or end view of it. I make
this vessel of wood, stoneware, or any other fit and convenient material; and
(when necessary) I line it with some material which will preserve it from the
effects of any chemical action to which it may be exposed. B and C are cells
with taps b for drawing off contents; c, funnel stop-cocks for filling the vessel;
D, porous diaphragm dividing the cells B and C; E, electrodes, with their
binding screws e, for attachment to the source of the electric current or
currents; F, F, moveable heads for collecting and conveying the gases
generated; G, thermometer; H, guage containing hydrometer. The other
of the vessels which I have mentioned I make of similar material, and it is
furnished with two porous partitions, separating the interior of the vessel into
three compartments; Figure 3 being a transverse vertical section of the
vessel; and as the external appearance of this vessel is the same, or nearly the
sanie, as shewn in Figure 2, I think it unnecessary to give a side or end view
of it. The several parts of this vessel, shewn in Figure 3, which are similar
to those shewn in Figure 1, are marked with the same letters of reference,
the chief difference being that the vessel shewn in Figure 3 has two com-
partments B and B; in each of which one of the component parts of a salt
in solution is to be eliminated, instead of one, as shewn in Figure 1. When
either of these vessels is used I fill each of its compartments with a strong
solution of the salt to be decomposed. Contact is now made between the
sources of the electric current or currents and the proper attachments of the
vessel, so as to complete the electric circuit, and bring the current of elec-
tricity into action. When the decomposition of the saline substance com-
mences, which will be known by the evolution of gas from the electrodes,
steam is turned on so as to enter the jacket A, A, and cause the con-

page_text: tents of the vessel to attain a temperature of not less than one hundred
and twenty degrees Fahrenheit. The progress of the decomposition has a
tendency to produce inequalities or differences between the specific gra-
vities of the solutions in the different compartments of the vessel, and for
the purpose of diminishing endosmodic action as much as possible, whereby,.
in some of the cases, the eliminated substances might slowly recombine, I add
from time to time fresh portions of salt, of the same kind as that being
decomposed, to that compartment of the vessel in which the solution has the
least specific gravity, and it is also advantageous occasionally to add fresh
portions of saline matter to both or all the compartments, so as to maintain
the original degree of saturation of the solution. It will also be as well, in
the case of decomposition of the chlorides of potassium and sodium, occa-;
sionally to test the evolved chlorine, to ascertain whether or not it is free from
oxygen, as the presence of any of the latter gas is proof that a portion of the
electric power is being exerted upon the alkali produced, instead of upon the
saline substance; but I may add, that this will not be the case while there
exists in the solution any large amount of undecomposed chloride. If during
the operation it is wished to prepare carbonates of the alkalies, I transmit
into that compartment or compartments of the vessel which contains the
eliminated alkali, a current of carbonic acid gas, obtained in any convenient
manner, and in due proportion to the decomposing action which is taking place,.
and in proportion as it is wished to prepare a proto-carbonate, sesqui-carbonate,
or bi-carbonate of the alkali. When the operation of decomposing salts of
potassa and soda is considered complete, that is, when the greater part of the
saline matter employed is deconiposed, I break the connection between the
apparatus supplying the electric current or currents and the decomposition
vessel, and draw off the alkaline solution (whether carbonated or not) from
the compartment which contained it; I then proceed to treat this product
according to the nature of the alkali which it contains, and according as
it may be carbonated or not, so as to obtain the alkali or carbonated alkali in
the desired form or state. The processes which may be used for this purpose
are well known, and will readily suggest themselves to those acquainted with
these manufactures, and forming no part of my Invention it is unnecessary
to describe them. If the saline matters operated upon as above are the
chlorides of potassium or sodium, the chlorine eliminated being driven off,
the solution left in the other compartment may be drawn off and mixed
with the solution with which it is intended to refill the vessel for the
next operation. But if the saline solution be a nitrate or sulphate of an

page_text: alkali, the other compartment of the vessel will contain a quantity of the
acid which has been eliminated during the process, and this acid will be
found mixed with part of the undecomposed salt remaining in the solu-
tion. If this acid be nitric acid it may be separated by distillation in a
stoneware retort, but when it is sulphuric acid, previously to the distilla-
tion it is to be evaporated so as to become concentrated, and then to be
allowed to stand for a day or two to deposit as much of the saline matter as
possible, the acid may then be removed by distillation. When the object or
chief object of the decomposition is to obtain the alkaline base of a salt, I
sometimes facilitate the operation, and reduce the intensity of the electrical
currents required for that purpose, by employing in that compartment of the
vessel in which the chlorine or acid would be evolved, a pole or electrode made
of zinc, iron, or other metal which will combine with the chlorine or acid as it
is eliminated during the process. The metallic salts thus obtained may be
separated from the solution by any of the known means applicable for that
purpose, or the metallic oxides may be produced from them, or they may be
used for the production from them of the pure metals in the manner which will
be described hereafter. When the salt to be operated upon in manner before
described is nitrate of soda, and I find (as is frequently the case with the
commercial article) that it contains much chloride of sodium, I first purify it
by crystallization. In the decomposition of this salt I employ a zinc pole or
electrode, and I thus obtain the alkali in one compartment and nitrate of
zinc in the other; now, in this as well in the operation before described, I
sometimes transmit a current of carbonic acid into the compartment containing
the alkali. The nitrate of zinc thus obtained may have the nitrate of soda left
undecomposed in it separated by crystallization, or it may be decomposed by
lime or its carbonate, and the resulting nitrate of lime prepared in a fit state
for commerce; or the nitrate of lime may be 'decomposed with sulphate or
carbonate of potassa, by which nitrate of potassa will be formed. Instead of
using lime as before mentioned, baryta, ströntia, magnesia, ammonia, or their
carbonates, may be employed, either for the preparation of the nitrates of those
bases, or for the subsequent production of nitrate of potassa. When by this
Invention it is wished only to prepare chlorine gas, I operate upón hydrochloric
acid, or upon a mixture of chloride of potassium and diluted sulphuric acid
(containing not less than one-tenth of real acid), and it will be found that
electricity of so bigh a degree of intensity will not be required for this operation
as when both the constituents of a saline substance are to be eliminated in a
separate state. The chlorine thus obtained may be conveyed away and collected

page_text: for use. During the action above described hydrogen will be evolved in one
of the compartments, and may be conveyed away in any convenient manner.
and used as a source of heat or for other useful purposes: When I operate
upon a nitrate or sulphate, and do not employ an oxidizable pole or electrode,
oxygen gas will be evolved in the other compartment with, the acid, and the
oxygen may be conveyed away and collected in any suitable. manner, and it
may be used for the preparation of carbonic acid to be employed as herein-
before described...
The second part of.my Invention consists of a mode of preparing or obtain-
ing the metals of the alkalies and alkaline earths by the united action of
electricity and heat. For performing this part of my Invention by the united
action of electricity and heat, I employ a vessel of the form shewn in Figure 5,
which is made of iron, or other suitable material capable of bearing à full red
heat. In this Figure, A is the vessel which should be at least half an inch
thick, and if made of iron, previously to its being used should be coated over
its exterior with clay or other substance to preserve it from the action of the
fire; B, moveable head for the collection of the metals;. C, electrodes, with
their attachments e; D, flanges to support the vessel upon the furnace. The
covered compartment F, being that in which it is intended to eliminate
the metals, is supplied with a carbon electrode, and the uncovered compart-
ment is supplied with a gold electrode; but I wish it to be understood that I
do not restrict myself to the particular form of apparatus, or to the material to
be used for electrodes. The vessel is filled with.dry saline matter, so that when
it is in a state of fusion it shall reach the 'dotted line; the partition keeps the
eliminated substances from reacting upon each other, and also excludes: the air
from the compartment in which the metal is eliminated, the access of which
would cause the metals to be oxidized. The vessel is placed in a furnace where
it can be subjected to the action of a full red heat, and when the saline matter
is in a state of fusion, contact is made between the decomposing vessel and
the apparatus supplying the electric current or currents, the intensity of which
should at least be equal to that which would be supplied by ten cells of Daniell's
battery arranged for intensity, but of course this depends upon the nature of
the salt which is being decomposed. The fused salt is maintained at that
temperature which will ensure the instantaneous volatilization of the metal, as
it is eliminated, and a proper receiver (such a one as is.usually employed for
the preparation of such metals will answer) is connected air-tight with the
narrow tube projecting from the head. The metal is received and preserved
in any convenient fluid hydrocarbon. The salts which I usually employ

page_text: are the chlorides, iodides, or bromides of the metals of the alkalies or
alkaline earths. When a bromide or iodide is being operated upon, I attach
to the compartment of the decomposing vessel in which the bromine or iodine
is eliminated a means of collecting these elements, so that they may not be
wasted.
The third part of my Invention consists of a made of converting chlorides of
potassium and sodium, and of the metals of the alkaline earths, into hypo-
chlorites and chlorates by means of a succession of decompositions in the solu
tion of the salt operated upon, when induced by the agency of electricity.
The mode in which I produce this effect is as follows:-A warm solution,
and nearly saturated, of the chloride of potassium or other chloride to be
operated upon is prepared and placed in a vessel furnished with two electrodes;
and in Figure 4 I have shewn a vessel furnished with a pair of electrodes, and
constructed in such a manner as to be convenient for carrying this part of my
Invention into effect. In this Figure, B is the interior of the vessel, which is
furnished with a steam jacket A with connection to boiler a and waste steam
tap.d; G, thermometer; E, E, electrodes placed over each other, the lower one
being intended for the elimination of the chlorine, and the upper one for the
elimination of the alkali; c, e, attachments of the electrodes. I have found it
advantageous to add to the solution of the chloride a portion of free alkali or
alkaline earth equal to about a tenth of the quantity of the saline matter to
be decomposed.. The connection is now to be completed between the apparatus
which supplies the electric current or currents and the vessel, and if the object
be the formation of a chlorate, I maintain the action until from one-half to
two-thirds of the original saline matter shall be converted into a chlorate.
¡
The agency of the electricity first decomposes the chloride, the chlorine being
climinated at one of the electrodes, and the alkaline or earthy metallic base
at the other electrode. The metal thus set free from its combination with
chilorine, combines with oxygen, and so becomes converted into an oxide; the
oxygen being obtained from the water of the solution, a portion of which is
therefore decomposed, and hydrogen gas evolved; and this gas may be allowed
to pass away, or, if desired, collected in another vessel. The liberated
chlorine will, when it is set free, combine with a portion of alkali or alkaline
earth in the solution, and a bypochlorite will be formed. The hypochlorite
thus formed will, by, the continued action of heat, be resolved, partly into a
chlorate of the alkali or earth, and partly into a chloride of the metallic
base, and the chloride will again be subjected. to decomposition, and a
ypochlorite formed, in like manner as herein-before described; and this

page_text: action or succession of decompositions and changes will go on until I
stop the process, which I prefer to do when from one-half to two-thirds
of the salinc niatter has been converted or formed into the required
chlorate. The quantity of chlorate thus obtained, or the greater portion of it,
being then separated by crystallization from the solution, the undecomposed
saline matter remaining in solution may, with an additional portion of the
same kind of saline matter, be subjected to the same process for the con-
version of a portion of it into a chlorate of the alkali or carth, as already
described. If I desire to produce a hypochlorite of the alkali or carth, I
merely keep the vessel warm, (say from about one hundred degrees to one
hundred and twenty degrees of Fahrenheit's thermometer, without applying
the higher température, which it is well known is requisite to produce a
chlorate from a hypochlorite; and I continue the process until as much of the
saline matter has been converted into a hypochlorite as may be required for
the purpose to which the solution is to be applied. This mode of forming a
hypochlorite of the alkalies and alkaline earth's may be used for preparing a
bath for the purpose of bleaching various kinds of goods; and the bath may
be strengthened from time to time by the action of the electric current or
currents.
The fourth part of my Invention consists of a mode of separating metals
from each other by the agency of a current or currents of electricity; and by
means of vessels divided into two or more compartments separated from each
other by porous partitions, such metals being at the same time freed from
impurities: First, the separation of alloys of gold, silver, and copper, or of gold
and silver only. If the gold alloy contains less than three-fourths of silver or
of silver and copper, I add, according to circumstances, silver, copper, zinc,
lead; or any other metals which may be easily oxidized and suitable. As there
is a large quantity of silver in the market which contains small but variable
quantities of gold and copper, I adopt the usual method of melting a suitable
quantity of this with the alloy which it is desired to purify, and the resulting
compound is cast into suitable plates or bars of any convenient thickness.
Sometimes the silver contains sufficient gold to render it worth while to refine
without the addition of
A solution of a salt of silver (I prefer the
nitrate) is now prepared and placed in a vessel; such as shewn in Figure 3,
each of the compartments being filled. Sometimes for the diaphragms or
porous partitions I substitute a cell, as shewn in Figure 6; or I employ a
vessel to which heat can be supplied, either with partitions or diaphragms of
porous matérial, or a cell, as shewn in Figure 6, without heads, funnels, or
any more.

page_text: guages, which may be of any convenient shape. The alloy in bars or plates
is placed in the inner compartment and attached to one of the conductors of
the current or currents of electricity, and into the outer compartment or com-
partments is placed a thin plate or plates of silver connected with the other
conductor of the current or currents of electricity to receive the deposited
metal. The proper connections are now made between the binding screws
and the source of the electric current or currents, and the action allowed to
continue until the bars or plates are nearly dissolved. During this operation
silver from the.solution is deposited upon the receiving plate or plates, and the
silver or copper (if any) of the bars or plates pass first into the solution, and.
then the silver is subsequently deposited upon the receiving plate or plates..
If desired, the receiving plates may be taken out from time to time, and the
deposited silver removed to be washed and melted in the ordinary manner.
In this process only the silver and other metals oxidizable under these circum-
stances will pass into the solution; the gold will become detached and remain
in the compartment containing the bars or plates which it is the object to
purify, and when it has been collected, treated with a little nitric acid to
remove any particles of silver that may adhere to or be commixed with it,"
will be ready to be melted in the usual way. In time, if the alloy operated
upon contained much copper, the solution will become so contaminated with
this metal that the silver must be separated from it and a fresh solution em-
ployed. When silver is not to be obtained, or, for other reasons, it is not
desired to employ it, the gold may be alloyed with any easily oxidizable metal,
and the product cast into bars or plates, and placed in a solution composed of.
any suitable quantity of hydrochloric or sulphuric acid, or chloride of the
metals of the alkalies or alkaline earths, and placed in the vessel, as before
described, and contact being made with the source of the electric current or
currents, the action is allowed to continue until the greater portion of the
metal is dissolved. During this operation neither the gold nor the silver
passes into the solution, but being disintegrated, both remains in the compart-
ment which was occupied by the bars or plates. The pulverulent mixture of
gold and silver is now washed, treated with a little nitric acid to remove the
small quantity of silver, which will now be easily separable. by this means.
When copper is used, and .dilute hydrochloric or sulphuric acid, chloride
of copper or
sulphate of the oxide of.copper will be formed, and these salts may
e crystallized for the market, or a solution of the chloride of copper, or
of the sulphate or nitrate of the oxide of copper may be substituted for those
cids, and by placing a receiving plate in the proper compartment, I thus.

page_text: reproduce the metallic copper to be used in preparing fresh portions of the
alloy, or send it into the market as pure copper. I should here observe, that
the intensity of the electric current or currents required for the operations
described in this division of this Specification is much lower than is required
for the former operations, being of no higher degree of intensity than is obtain-
able from one of Daniell's cells of what is termed the constant battery.
It may be as well to state here, that sometimes in carrying out the various
processes described throughout this Specification; I employ a current or currents
of electricity of a higher degree of intensity than is required for one decom-
posing vessel, and I then place two or more vessels properly connected in the
same circuit, so as to enable me to carry on two or more similar or dissimilar
processes at one and the same time with only one source of the electric current
or currents. The purification of other metals, such as iron, copper, nickel, and
cobalt, may be affected by the employment of solutions of these metals; and
the solution of the impure metals being affected in one compartment of the
decomposition vessel, and deposition of one of the metals by the agency of the
electric current or currents in the other compartment upon a plate of metal or
carbon electrode placed for the reception of such metal. Thus, for the purifi-
cation of iron, I prepare a solution of the protosulphate of iron, or of the
protochloride of iron; this solution is placed in the vessel, and in one of the
compartments I place the impure iron in bars or pigs, and in the other
compartment a receiving plate. The apparatus supplying the electric current
or currents is now attached, and contact maintained until the whole or the
greater portion of the iron is dissolved in the one compartment and precipi-
tated in the other compartiment, at which period the receiving plate is taken
out, the iron removed from its surface, and the plate being returned to the
vessel and a fresh supply of iron to be purified being placed in the other
compartment, the action is continued as before. During this operation I
have always found the rapidity of the action accelerated by the application
of heat to the solution from time to time, and the addition of a small
quantity of dilute sulphuric or hydrochloric acid. The precipitated iron
should be thoroughly washed, and sometimes I have found it advantageous to
wash it once in very dilute hydrochloric or sulphuric acid, when it will be
found to be very pure and fit to be worked up in any way that may be desired.
Iron thus prepared is remarkably free from carbon, sulphur, phosphorous, and
other impurities.
The electrodes which I usually employ in carrying out this Invention are
prepared as follows:-I obtain some lamp black or tar, if the latter, care

page_text: should be taken that it has not been contaminated by earthy matters, and
coke it, and then reduce it to a very fine powder. This coke or lamp
black is intimately mixed with sugar or some such article employing enough
only to bind the mass. I use a mould made by boring a hole in a solid
piece of iron and then cutting it in half, holding the two halves together
by iron rings. The mixture is placed in this mould, and the contents subjected
to powerful hammering. The mould with its contents is now placed in an
oven, which is gradually heated, until finally the whole becomes red hot, the
mould is then withdrawn, allowed to cool, and being opened the piece of carbon
is taken out. This piece of carbon is now placed while warm into a strong
solution of sugar, or some of the original tar made hot will do, and subjected
to the action of an air pump whilst still in the fluid; it is then to be placed
in a crucible and covered with powdered charcoal or coke, and heated red hot;
this operation is to be repeated until the piece of carbon has attained the
required density, when it is finally subjected to the most intense heat than can
be commanded for several days, when it will be fit for use as electrodes.
Having now described the nature of my said Invention, and the manner
in which the same is to be performed, I declare that I claim as of my
Invention,-
Firstly, the mode of decomposing, by the agency of electricity, saline or
other substances in solution, by means of a vessel divided into two or more
compartments separated from each other by partitions of porous materials,
as herein before described.
'
Secondly, the mode of preparing or obtaining the metals of the alkalies
and alkaline earths by the action of electricity and heat, as herein-before
described.
Thirdly, the mode or modes of converting chlorides of potassium and
sodium, and of the metallic base of the alkaline earths, into hypochlorites and
chlorates of the alkalies and alkaline earths, as herein-before described.
And, fourthly, the separation of metals from each other by the agency of
electricity, and by means of vessels divided into compartments separated from
each other by porous partitions, and at the same time freeing such metals from
impurities as herein-before described.
In witness whereof, I, the said Charles Watt, have hereunto set my
hand and seal, this Twenty-fourth day of March, One thousand eight
hundred and fifty-two.
CHARLES (L.S.) WATT.

page_text: AND BE IT REMEMBERED, that on the Twenty-fourth day of March,
in the year of our Lord 1852; the aforesaid Charles Watt came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, 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 Twenty-fourth day of March, in the year of oui Lord One
thousand eight hundred and fifty-two.