IMPROVEMENTS IN EFFECTING THE PURIFICATION OF CAST IRON, MALLE- ABLE IRON, CAST STEEL AND MALLEABLE STEEL, AND OTHER METALS OR ALLOYS
Year: 1872

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN EFFECTING THE PURIFICATION OF CAST IRON, MALLE-
ABLE IRON, CAST STEEL AND MALLEABLE STEEL, AND OTHER METALS OR
ALLOYS." A communication from abroad by Jean Baptiste Lucien
Forquignon, of Nancy, Mining Engineer, and Leon Michel Ehrmann,
of Paris, in the Republic of France, Chimiste.
Sealed the 31st January 1873, and dated the 12th September 1872.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 12th September 1872.
•
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN EFFECTING The Purification of Cast Iron,
MALLEABLE IRON, CAST STEEL AND MALLEABLE STEEL, AND OTHER METALS OR
ALLOYS," a communication to me from abroad by Jean Baptiste Lucien
Forquignon, of Nancy, Mining Engineer, and Leon Michel Ehrmann, of
Paris, in the Republic of France, Chemiste, to be as follows:-
This Invention relates to improvements in the treatment of cast iron,
malleable iron, cast steel, malleable steel, and other metals or alloys, and

page_text: has for its chief object effecting the purification of such, or of inter-
mediate products by means of electric or of magneto-electric agency,
when such products are in a heated condition, and consists generally in
the application of electric currents to the treatment by a dry method of
metals, alloys, metallic ores, or accessory products brought to a suffi-
ciently elevated temperature for the purpose of modifying their physical
or chemical properties.
The employment of electricity in metallurgy has been the subject of
numerous investigations, but these enquiries have not hitherto given
results satisfactory in an economical point of view.
It is unnecessary here to enter into the extensive details of the mode
of operation and special treatment of each substance. I shall therefore
simply give a general description of the applications of which the new
method appears to be susceptible, and of the principal arrangements
which may be adopted for this purpose.
The changes which the electric influence is capable of producing on
the different bodies correspond to two distinct classes of phenomena :—
1st, physical modifications; 2nd, chemical modifications. These modi-
fications depend upon the nature of the currents employed, and they
may be produced either together or separately with the required
intensity.
I shall first take into consideration the physical modifications, or the
molecular changes produced by an electric current of a variable nature
in a fused metallic mass, or of such a mass brought to a temperature at
least approaching the fusing point. The liquid or nearly liquid condi-
tion is particularly favorable to the production of permanent molecular
groups, for the distinct characteristic of electric actions is to communicate
not merely to the molecules or integral particles but to the atoms them-
selves a suitable energy, which depends on the quantity of electricity,
and also on what might be called the electric capacity of the atoms. The
electric action continued during the cooling of the mass fixes and main-
tains the equilibrium previously obtained.
I give as an example the moulding and casting, say, of a piece of
ordnance in bronze, cast iron,.or-steel, or of a projectile, a roll of a rolling
mill, or of any other piece.
For the sake of simplicity I will assume that the piece is of cylin-
drical form, and either hollow or solid. To the two poles of the machine

page_text: are connected two electrodes, which are isolated from the mould when
the piece is in the form of a shell, making a projection in the interior of
the mould, so that at the moment when the metal is run into the mould
the said molten metal closes or completes the circuit. According to the
5 molecular texture that it is required to obtain I may then by employing,
for example, magneto-electric machines cause alternate currents to pass
into the casting, in order to render it homogeneous without the aid of
commutators, or, in lieu thereof, I may cause currents to pass there-
through, reestablished by commutators according to circumstances. The
current should be caused to pass in the lines of greatest resistance; thus,
for a column of cast iron the current would pass in a longitudinal.
direction; for rolls of rolling mills, grinding rollers, gearing, &c., the
current would be caused to pass in a direction perpendicular to the axis,
or by preference from the centre to the circumference; the pieces may
be readily laid hold of at each of their extremities by metallic pincers
connected to the poles in order to subject them to the action of the
rolling mill, drawing apparatus, or steam hammer; the same processes
may be applied to pieces which are reheated or annealed.
I shall now refer to the chemical modifications or changes which take
place by the application of electricity, aided by a variable degree of heat
(which may be raised to a fusing point if required) in a mixture or
combination of several simple bodies united by an affinity more or less
opposed to chemical reactions, and subjected to influences tending to
destroy or consolidate their union.
The most important branch of metallurgy being that of iron, it is to
this metal that I shall first apply the preceding considerations.
The bodies which are found in most cases in cast iron may be divided
into three groups, videlicet:-
1st. The electro-negative group (sulphur, phosphorus, arsenic).
2nd. The intermediate group (silicium, titanium, carbon).
3rdly. The electro-positive group (iron, manganese, vanadium, tung-
sten, molybden and more rarely aluminium, magnesium, calcium.
Now an electric current of suitable duration and intensity effects in
the midst of the metal which is in perfect fusion a separation of these.
elements into two perfectly distinct groups, each proceeding to a different
pole. I may therefore, by graduating the electric action, which operation
3rdly. The electro-positive group (iron, manganese, vanadium, tung-
sten, molybden and more rarely aluminium, magnesium, calcium.
Now an electric current of suitable duration and intensity effects in
the midst of the metal which is in perfect fusion a separation of these.
elements into two perfectly distinct groups, each proceeding to a different
pole. I may therefore, by graduating the electric action, which operation

page_text: may be performed with facility, obtain all the grades between the most
impure cast iron and soft wrought iron.
The electricity not only acts upon the free carbon, but it also performs
electrolytic actions on the combined carbon, consequently I am enabled'
to separate at one pole the sulphur, phosphorus, and arsenic, then the
silicium, titanium, and carbon; whilst at the other pole I concentrate
the two metallic elements (iron, manganese, &c.).
By various arrangements of the mode of operation, depending on the
position and nature of the electrodes, the intensity and duration of the
currents, and the simultaneous intervention of suitable mechanical or
chemical actions, I am enabled to retain in the cast iron either a portion
or the whole of the sulphur, phosphorus, silicium, carbon, &c., or to
eliminate them entirely by bringing them to the surface of the bath,
where by a powerful oxidation they are caused to disappear.
In treating the cast iron according to this Invention at the moment
when it leaves the blast furnace for the elimination of the electro-
negative bodies therein, the metal is run into sand moulds of, say, the
following size, videlicet, about 1 inch deep, 2 feet 6 inches wide, and
about 6 feet long. The two extremities of the sheet of metal are to be in
communication with the poles by iron rods, and the surface is exposed to
the open air. The elimination of noxious substances may be assisted by
agitating the molten mass near the positive pole with an iron rabble or
a wooden rod.
The cast iron may also be collected in basins lined with conducting
brasque. This brasque is to be in communication with one of the poles,
whilst the other pole dips into the upper layer of the bath. This
arrangement admits of the concentration of the electro-negative elements
or their elimination, according as the positive or the negative pole
occupies the lower part. The positive electrode may terminate in a rod
or stirrer with which to agitate the mass. This arrangement admits of
the surface of the metal being cooled from time to time by water, and
The cold water
removed in the form of sheets or discs of refined metal.
may be replaced by an air blast, which would have the advantage of
producing a surface agitation, and of rendering more active the oxidation
of the impurities.
In order to effect the concentration of the clectro-negative bodies the
cast iron is to be run into a vertical ingot, the positive pole being in com-

page_text: munication with the lower part, and the negative pole with the upper
part; the sulphur, phosphorus, silicium, and carbon are carried to the
lower part out of contact with the atmosphere, and are concentrated
around, the anode; the cast iron which is purified and enriched with
manganese, &c., is carried to the cathode fixed to the upper part.
.
The arrangements which I have indicated may be also applied to
reverberatory, puddling, muffle, and cupola furnaces. The furnace should
of course be provided with doors or tapping holes opposite to each other,
and placed near the electrodes.
In order to facilitate the manipulations the hearth may be slightly
raised towards the middle, so as to form a species of ridge sufficiently
low to be covered by the mass in fusion, forming the normal charge of
the furnace. As a greater precaution a trench or canal may be formed
in this ridge, so that the positive bath and the negative bath remain in.
electrical communication until the termination of the operation of
running the metal.
Similar arrangements may be employed in the
treatment of other metals, such as tin, lead, copper, &c. .
The same arrangements enable me to treat out of contact with the
atmosphere metals which are readily oxidizable, such as arsenic, anti-
mony, bismuth, &c.; and particularly zinc, which is the most important
of the whole; the enormous losses attending the existing modes of treat-
ment are thus prevented.
For example, they may be submitted to the simultaneous influence of
heat and electricity, either in close vessels or in crucibles covered with
brasque at their lower part, which should communicate with the suitable
pole, the opposite pole being in contact with the upper part of the
crucible.
I may here remark that the simple bodies are separated from each.
other so much the more readily as their electrical conditions are more
opposite, and therefore the small quantities of precious metals, which are
essentially electro-positive, contained in certain substances, such as grey,
copper ore or argentiferous gelena, mispickel, auriferous magnetic
pyrites, and all similar ores and analogous art products may, if desired,
be concentrated with the greatest facility. For this purpose it would
suffice to dissolve the ores to be treated in any fusible material which
would serve as a vehicle and as a conductor to the electricity, for

page_text: example, mercury, lead, zinc, copper sulphurets in fusion, and the like,
may be used for this purpose.
An analogous mode of treatment may be applied to the separation of
metals and metalloids from the scoria, slag, and other accessory products
of metallurgical operations in which they may be contained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 12th March 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
year
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of September, in the of
our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN EFFECTING THE PURIFICATION OF CAST IRON, MALLEABLE
IRON, CAST STEEL AND MALLEABLE STEEL, AND OTHER METALS OR ALLOYS,"
a communication to me from abroad by Jean Baptiste Lucien
Forquignon, of Nancy, Mining Engineer, and Leon Michel Ehrmann,
of Paris, in the Republic of France, Chemiste, upon the condition
(amongst others) that I, the said John Henry Johnson, my executors or
administrators, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :—
The said Invention relates to improvements in the treatment of cast
iron, malleable iron, cast steel, malleable steel, and other metals or
alloys, and has for its chief object effecting the purification of such by
means of magneto-electric agency when such products are in a heated
condition, and consists generally in the application of magneto-electric
currents to the treatment by a dry method of metals, alloys, and metallic
ores brought to a sufficiently elevated temperature for the purpose of
modifying their physical or chemical properties.
The employment of electricity in metallurgy has been the subject of
numerous investigations, but these enquiries have not hitherto given
results satisfactory in an economical point of view.. This is probably due
to the investigators having confined their efforts to the reduction of the
metals in the metallic condition of their saline solutions.
It was there-
fore absolutely necessary to resort to the use of solvents and reagents
both costly and cumbersome, large masses of liquids and apparatus both
uncertain and delicate in manipulation. The treatment of metals by
the dry method, which is so superior commercially to the humid systems,
appears to be above all others capable of borrowing from electricity its
remarkable powers, and its resources are so little known. In the
majority of metallurgical establishments the dry system is exclusively
employed; the humid system, on the contrary, is only employed in
certain special cases. It therefore became desirable to discover a process
which, without requiring any considerable or costly alterations in the
works, and without essentially changing the methods in use, would
provide a force both novel and capable of being applied with facility in
addition to the physical and chemical forces at present in operation, and
to combine in metallurgy the employment of igneous fusion with
magneto-electricity, which appears so much the more adapted to this
purpose, since it may become at will the auxiliary or the antagonist of
the chemical affinities, and as it may be managed with greater facility
than steam, and transmits its mechanical and chemical action more
readily than steam, and to greater distances. What moreover renders it
so valuable an agent in commercial operations is the facility with which
its action may be graduated in increasing its rapidity, and instantaneously

page_text: altering its direction and nature, and in fact the almost mathematical
precision of which its employment is susceptible. The same cannot be
said of the chemical, mechanical, or calorific actions, which it is fre-
quently impossible to modify at will.
The sources of electricity will not be wanting in its application to new
purposes. The machines on the system of Silmens, Van Maldron, Wilde,
Gramme, and Ladd have recently opened up to arts and manufactures
unexpected resources.
It is unnecessary here to enter into extensive details as to the mode. of
operation and special treatment of each substance, I shall therefore
simply give a general description of the applications of which the new
method appears to be susceptible, and of the principal arrangements
which may be adopted for this purpose.
:―
The changes which the electric influence is capable of producing on
the different bodies correspond to two distinct classes of phenomena
1st, physical modifications; 2nd, chemical modifications. These modi-
fications depend upon the nature of the currents employed, and they
may be produced either together or separately with the required
intensity.
I have not moreover considered the magnetic phenomena evolved in
the cast iron, wrought iron, or other metals brought to a temperature,
however elevated that temperature may be, even that of fusion, without
also taking into consideration whether this magnetic influence continues
or not after the cooling.
I shall only direct attention eventually to the modifications undergone
through affinity and cohesion under the influence of magneto-electricity,
in conjunction with heat.
1st. Physical Modification.-I shall first take into consideration the
mollecular changes produced by an electric current of a variable nature
in a fused metallic mass, or of such a mass brought to a temperature at
least approaching the fusing point. The liquid or nearly liquid condi-
tion is particularly favorable to the production of permanent mollecular
groups, for the distinct characteristic of electric actions is to communicate
not merely to the molecules or integral particles, but to the atoms them-
selves a suitable energy, which depends on the quantity of electricity,
and also on what might be called the electric capacity of the atoms. By
virtue of this energy which is imparted, new forces which are derived

page_text: their extremities by metallic pincers connected to the poles, in order to
subject them to the action of the rolling mill, drawing apparatus, or
steam hammer. The same processes may be applied to pieces which are
reheated or annealed.
2nd. Chemical Modifications.—I shall now refer to the changes which
take place by the application of magneto-electricity aided by a variable
degree of heat (which may be raised to a fusing point, if required) in a
mixture or combination of several simple bodies united by an affinity
more or less opposed to chemical reactions, and subjected to influences
tending to destroy or consolidate their union.
The most important branch of metallurgy being that of iron it is to
this metal that I shall first apply the preceding considerations. Cast
iron, which is a mixture of an enormous excess of metal with small
quantities of extraneous matters irregularly dispersed, is not readily
subjected to the ordinary chemical actions, and for that reason is fre-
quently unsuitable for certain important purposes, such as the manu-
facture of Bessemer steel.
The bodies which are found in most cases in cast iron may be divided
into three groups, videlicet:-
First. The electro-negative group (sulphur, phosphorous, arsenic).
Secondly. The intermediate group (silicium, titanium, carbon).
Thirdly. The clectro-positive group (iron, manganese, vanadium, tung-
sten, molybden, and more rarely aluminium, magnesium, calcium.
Now a magneto-electric current of suitable duration and intensity
effects in the midst of the metal which is in perfect fusion a separation
of these elements into two perfectly distinct groups, each proceeding to a
different pole. I may therefore by graduating the electric action, which
operation may be performed with facility, obtain all the grades between
the most impure cast iron and soft wrought iron.
There are different types of magneto-electric machines which with or
without commutators give currents alternate or broken, the intensity of
which may be varied by varying the speed of rotation. If induction
apparatus are employed they may be had of any power and size, in fact,
whatever may be the source of the electricity by adapting thereto a
circuit breaker I may obtain molecular vibrations of any order whatever.

page_text: The same considerations also apply to the physical modifications.
The electricity not only acts upon the free carbon, but it also performs
electrolytic actions on the combined carbon, consequently I am enabled
to separate at one pole the sulphur, phosphorous, and arsenic, then the
silicium, titanium, and carbon; whilst at the other pole I concentrate
the true metallic elements (iron, manganese, &c.)
The treatment of cast iron by this process does not require a consider-
able amount of time or electric currents of exceptionable intensity. In a
series of experiments made on a small scale, the cast iron (having been
purposely mixed with a relatively large quantity of phosphorus of iron)
a current of four small Bunsen's elements, acting for forty or fifty seconds
was sufficient to effect the separation in a very clean manner at one of
the poles of the phosphorus, sulphur, and silicium, the combined carbon
appeared already in a free state, and communicated to the cooled bottom
the characteristic aspect of the cast iron treated.
By various arrangements of the mode of operation depending on the
position and nature of the electrodes, the intensity and duration of the
currents, and the simultaneous intervention of suitable mechanical or
chemical actions, I am enabled to retain in the cast iron cither a portion
or the whole of the sulphur, phosphorus, silicium, carbon, &c., or to
eliminate them entirely, by bringing them to the surface of the bath,
where, by a powerful oxidation, they are caused to disappear.
I do not take into consideration here the nature or intensity of the
electric current. I shall note the special arrangements in certain cases
taken as examples, and simply mention certain operations, the details of
which will readily explain the mode of proceeding in more special
cases.
First. Treatment of the cast iron at the moment when it leaves the
blast furnace :-
a. Elimination of the Electro-negative Bodies.-The cast iron is run
into sand moulds of, say, the following size, videlicet, about one inch deep,
two feet six inches wide, and about six feet long. The two extremities
of the sheet of metal are to be in communication with the poles by iron.
rods, and the surface is exposed to the open air. The elimination of
noxious substances may be assisted by agitating the molten mass near
the positive pole with an iron rabble or a wooden rod.
..;

page_text: The cast iron may also be collected in basins lined with a conducting
brasque. This brasque is to be in communication with one of the poles,
whilst the other pole dips into the upper layer of the bath. This
arrangement admits of the concentration of the electro-negative elements
or their elimination, according as the positive or the negative pole
occupies the lower part. The positive electrode may terminate in a rod
or stirrer, with which to agitate the mass. This arrangement admits of
the surface of the metal being cooled from time to time by water, and
removed in the form of sheets or discs of refined metal. The cold water
may be replaced by an air blast, which would have the advantage of
producing a surface agitation, and of rendering more active the oxidation
of the impurities.
b. Concentration of the Electro-negative Bodies.-The cast iron is to be
run into a vertical ingot, the positive pole being in communication with
the lower part, and the negative pole with the upper part, the sulphur,
phosphorus, silicium, and carbon are carried to the lower part out of
contact with the atmosphere, and are concentrated around the anode.
The cast iron which is purified and enriched with manganese, &c., is
carried to the cathode fixed to the upper part. It is evident that in this
case, as in the electrolyte of liquids, substances may be taken for elec-
trodes which are capable of undergoing a chemical action on contact
with bodies which are brought thereto under the influence of the
current.
Second. The very simple arrangements which I have indicated may
be also applied to reverberatory, puddling, muffle, and cupola furnaces.
The furnace should of course be provided with doors or tapping holes
opposite to each other and placed near the electrodes.
In order to facilitate the manipulations the hearth may be slightly
raised towards the middle, so as to form a species of ridge sufficiently
low to be covered by the mass in fusion forming the normal charge of
the furnace. As a greater precaution a trench or canal may be formed
in this ridge, so that the positive bath and the negative bath remain in
electrical communication until the termination of the operation of
running the metal. Similar arrangements may be employed in the
treatment of other metals, such as tin, lead, copper, &c.
The same arrangements enable me to treat, out of contact with the
atmosphere,-metals which arc. readily oxidizable, such as arsenic, anti-

page_text: mony, bismuth, &c., and particularly zinc, which is the most important
of the whole; the enormous losses attending the existing modes. of
reatment are thus prevented; for example, they may be submitted to
the simultaneous influence of heat and electricity, either in close vessels
or in crucibles covered with brasque at their lower part, which should
communicate with the suitable pole, the opposite pole being in contact
with the upper part of the crucible.
mony, bismuth, &c., and particularly zinc, which is the most important
of the whole; the enormous losses attending the existing modes of
treatment are thus prevented; for example, they may be submitted to
the simultaneous influence of heat and electricity, either in close vessels
or in crucibles covered with brasque at their lower part, which should
communicate with the suitable pole, the opposite pole being in contact
with the upper part of the crucible.
The treatment of white cast iron of bad quality would give rise to the
following succession of phenomena.
First. Production of white cast iron free from sulphur, phosphorus,
and arsenic.
Second. Production of white cast iron with free silicium.
Third. Production of grey cast iron (the combined carbon passing into.
a free state).
Fourth. The production of steel iron more or less decarburated.
Fifth. Production of soft wrought iron, which is then subjected to.
suitable mechanical operations. These operations would be carried out
in a similar manner to that of refining on Bessemer's process; but they
would have the important advantage over this process of being regulated.
and performed with greater facility. It is evident moreover that by a
mixture of suitable cast irons, or the previous additions of useful sub-
stances (manganese, tungsten, chromium, &c.) in a free or combined
state, the cast iron may be enriched at will, and this addition will be
favorable to the elimination of the noxious elements.
Also, by subjecting mixtures of natural or artificial compounds suit-
ably chosen to electric decomposition, the liberation of the metals they
contain may be made available for the ready production at the polar
surface of new alloys. The above considerations will shew the importance
of this method, and the incontestable advantages which it offers with
regard to rapidity, regularity, and economy in hand labour. It is in fact.
the only method which by its precision admits of obtaining in every case:
products of a constant quality determined beforehand.
The importance of the chemical modifications undergone by the
electrified cast iron greatly outweighs the importance of the physical
modifications. The contrary would take place. as regards wrought iron.

page_text: and steel, the texture, elasticity, strength, and hardness of which would
vary certainly within wide limits with the disturbance or agitation which
is produced in the molecules.
It will be unnecessary to enter into long details on the magneto-
electric treatment by the dry system of all the other metals, metallic
ores and products of art hitherto known, as their separation and purifica-
tion will be analogous to the methods herein-before described.
I claim the priority and exclusive property of this magneto-electrical
treatment by the dry system. The arrangement and mode of operating
the apparatus would be the same as for cast iron, steel, and wrought iron.
I may. here remark that the simple bodies are separated from each
other so much the more readily, as their electrical conditions are more
opposite, and I therefore deduce from this that the small quantities of
precious metals which are essentially electro-positive contained in certain
substances, such as grey copper ore, or argentiferous galena, mispichel,
auriferous magnetic pyrites, and all similar ores and analogous art pro-
ducts may, if desired, be concentrated with the greatest facility.
For
this purpose it would suffice to dissolve the ores to be treated in any
fusible material, which would serve as a vehicle and as a conductor to
the electricity, such for example as mercury, lead, zino, and copper
sulphurets in fusion.
An analogous mode of treatment may be applied to the separation of
metals and metalloids from the scoriæ, slag, and other accessory products
of metallurgical operations in which they may be contained.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,-
First. The application and use of electric currents produced by
magneto-electric machines, and especially by the machine of Gramme
and d'Ivernois, for the treatment by the dry system of metals, alloys, or
metallic ores, either brought to a state of fusion or to an elevated
temperature, substantially as and for the purpose herein-before described.
Secondly. The accomplishing the molecular modification of cast,
annealed, or reheated articles of cast iron, bronze, or steel, by passing

page_text: through such articles electric currents produced by magneto-electric
machines, and especially by the machine of Gramme and d'Ivernois, such
currents being caused to act upon the article whilst it is in a state of
semi-fusion, substantially as herein-before described.
Thirdly. The treatment by the dry system of impure wrought iron and
steel for the purpose of commercially separating the metalloids therefrom,
by the employment of the arrangements herein set forth, so as to com-
bine the action of heat and magneto-electric currents, substantially as
herein-before described.
In witness whereof, I, the said John Henry Johnson, have to
this my Specification set my hand and seal, the Twelfth day of
March One thousand eight hundred and seventy-three.
J. HENRY JOHNSON. (L.S.)