IMPROVEMENTS IN PREPARING COMPOUNDS OF CYANOGEN, AND PRINCIPALLY OF PRUSSIATES BY MEANS OF SULPHURETTED CARBAMIDS OR AMIDS WHICH SUPPLY SULPHURETS OP CARBON BY THEIR DECOMPOSITION
Year: 1860

page_text: in the Empire of France, Chemist, for the Invention of "IMPROVEMENTS
IN PREPARING COMPOUNDS OF CYANOGEN, AND PRINCIPALLY OF PRUSSIATES BY
MEANS OF SULPHURETTED CARBAMIDS OR AMIDS WHICH SUPPLY SULPHURETS OP
CARBON BY THEIR DECOMPOSITION."
Sealed the 11th January 1861. and dated the 26th July 1860.
PROVISIONAL SPECIFICATION left by the said Amedee Gelis, at the
Office of the Commissioners of Patents, with his Petition, on the 26th
July 1860.
с
I, AMEDEE GELIS, of 29 Boulevart St. Martin, Paris, in the Empire of
France, Chemist, do hereby declare the nature of the said Invention for
IMPROVEMENTS IN PREPARING COMPOUNDS OF CYANOGEN, AND PRINCIPALLY OF
PRUSSIATES BY MEANS OF SULPHURETTED CARBAMIDS OR AMIDS WHICH SUPPLY SUL-
PHURETS OF CARBON BY THEIR DECOMPOSITION," to be as follows-
I comprise, under the common denomination of sulpho-carbonate, ammo-
niacal or metallic sulpho-carbonates and sulpho-cyanides, which bodies only
differ from each other by the proportions of hydro-sulphuric acid they
contain.
Sulpho-carbonate, C*S*H*N*.
Sulpho-carbomate, C'SH'N-2SH = C*S*H*N⁹.
Sulpho-cyanide. C'S'H'N-4SH - C²S*H*N2.
Azote, which to this day has entered into the composition of prussiate of
potash and the different cyanic compounds made use of in trade, is derived
from two sources, viz., atmospheric air and animal residues, such as wool,

page_text: leather, hair, horns. and others. Thus two methods have been employed, one
which was called the English process, from its being the only one realized in
England, consists in causing masses of air to pass through piles of charcoal
impregnated with potash, and highly heated. This process requires a con-
siderable expense in fuel, and for this reason was never adopted in trade in
France, though of French origin. The second process, which supplies the
French market exclusively with cyanides and prussiates, consists in infinitely
varying the proportions of the matters made use of, and in the manner of
working or decomposing the animal substances above mentioned by means of
carbonates, sulphates, or sulphides of potash and soda raised to a high tem-
perature with or without the addition of lime or of feruginous compounds.
My improved process, for which I apply for Letters Patent, is based upon
a system of reaction. quite different to the above. I do not derive azote either
from air or animal matters. but from a manufactured compound, viz., ammonia,
which I fix by means of sulphuret of carbon; and I prepare with these two
products, suitably combined for the uses of trade, sulphuretted amides, or I
derive such sulphuretted amides ready formed from certain residues uncm-
ployed heretofore; and, finally, I transform such amides into sulpho-cyanides
of potassium and of sodium, which sulpho-cyanides being afterwards modified
by an appropriate metal such as iron, zinc, copper, lead, and others, are con-
verted either into prussiates of potash or soda, of cyanides of potassium or
sodium.
I first prepare sulpho-carbonate of ammonia (the latter in excess) through
the direct action of monosulphide of ammonia. with an excess of base, and in a
concentrated solution of sulphuret of carbon. This preparation, which appears
simple at first, however, presents some difliculties, sulphuret of carbon and the
concentrated solution of sulphide of ammonia being two liquids of different
densities which require a continuous agitation in order to mix them together,
which is not an easy matter to effect. This difficulty of contact would be an
obstacle to the combination, and would require too much time for the process
to become practicable did I not apply a means by which this first part of the
operation is much simplified. This consists in adding to the mixture of the
liquids fatty bodies in small quantities. any oil, for instance, thrown in in the
proportion of one to two per cent. of the weight of sulphuret of carbon. This
small amount of oil, on meeting an excess or surplus of ammonia, is saponified,
and thus becomes an emulgent by which the mixture is converted into an
opaque gelatinous mass. in which the two reactive substances are equally dis-
tributed. In these conditions the reaction is very quick, and the combination
is effected in a few hours, which is ascertained by the mixture becoming

page_text: limped a homogeneous transparent liquid is obtained of a most beautiful
somewhat reddish yellow hue. As to the additional soap or fatty body, it
remains floating on the surface, & may be easily decanted and made use of for
subsequent operations. I effect the above combination in a sheet iron cylinder,
provided at its lower part with a stop cock, which serves for elutriation when
the operation is finished. This cylinder is suspended at its centre on two
double supports, which permit of a rocking motion being imparted thereto; it
is fed with the liquids to be mixed through a socket at its proper part.
Sulpho-carbonate being thus prepared, other transmutations may then take
place. Now, I have ascertained that it suffices to raise the foregoing com-
bination to 90° or 100° centigrade in order to transform it successively into
sulpho-carbonate and sulpho-cyanide of ammonium. In the meantime that
the said compounds are produced, a considerable amount of sulphuretted
hydrogen or of sulph-hydrate of sulphide of ammonia will be evolved, the latter
compound being produced every time that sulphide of ammonia has been made
use of in excess, which must be a sine qua non, and which can be done as will
be explained hereafter, without prejudicing in any way the economy of the
process. The decomposition is easily effected both on a large & small scale
whether the heating is direct, or by means of a water bath or a current of
steam or superheated steam be injected into the liquid. I thus obtain on the
one hand in the boiler a colorless liquid containing only sulpho-cyanide of
ammonia, the treatment of which I will explain hereafter, and hydro-sulphuric
acid on the other hand. or rather sulphydrate of sulphide of ammonia dis-
tilled and received in the form of vapour in sheet-iron boxes with compart-
ments containing ammonia, thus, at the end of the operation, is produced more
sulphide of ammonia, or exactly the very salt that was employed at the
starting point. The solution of this salt is mixed with a fresh quantity of
sulphuret of carbon in the rocking cylinder, and the operation carried on again
as before will yield a fresh supply of cyanide of ammonia, and so forth inde-
finitely.
Here it is necessary to observe that the amount of ammonia is at the end
of the operation more considerable than that which was employed at the
beginning. hence, notwithstanding the various losses which cannot be pre-
vented, an abundant supply of this salt may be obtained, and the sulphuret of
carbon can always be treated by a more considerable amount of sulphide of
aminonia than that theoretically indicated, which surplus will render reaction
much easier, yet there may be a moment when in consequence of the accumu-
lation of that salt it will be possible to get rid of it, and I will, when treating
of residues, state what may be done therewith.

page_text: I will also presently refer to the colorless solutions left in the boiler, and
which contain sulpho-cyanide of ammonium.
First, the ammoniacal salt therein contained must be transformed into salt.
of potash or soda for they could not be easily evaporated without being par-
tially destroyed, such transformation may be obtained directly or by means of
calcareous salt, which has the advantage of allowing of the use of sulphates
which are still cheaper than carbonates. First, I ascertain by a mixture of a
small quantity the amount of sulpho-cyanide contained, then taking as a base
the whole volume which is known, I mix them in the boiler with a solu-
tion containing an equivalent quantity of mono-sulphide of potassium, or
sodium, required for effecting the transformation. This being done, I close
the boiler, and heat it again as before, a new decomposition is now produced,
the base of sulpho-cyanide is charged, and a fresh amount of sulphide of am-
monia or carbonate of ammonia is evolved, being condensed in the sheet-iron
bases & added to the quantity of sulphide already obtained, the operation
is complete when pure steam alone is scen to distil; the apparatus is then
uncovered, and the liquids decanted into a basin provided at its lower part
with an iron worm, heated by steam, and the solution is evaporated. This
evaporation is easily effected, and presents no particular feature so long as
the liquids have not reached a certain degree of concentration, and the tem-
perature does not exceed 100° centigrade for when evaporation commences at
a somewhat higher temperature, the sulpho-cyanide will show some symptoms
of decomposition. Evaporation is completed when a drop of the liquid poured
over a cold body will instantly form a crystalline bubble and being left at rest
in this state will yield fine crystals, which are easily dried. To take from
those crystals the sulphur which they contain, and to transform them into
simple cyanides, I mix together 100 parts of dried crystals & 60 parts of cast-
iron, or preferably, of wrought-iron cuttings; I place this mixture by small por-
tions into a cast-iron crucible, previously heated to redness.
The mass
directly melts and is afterwards concreted, and sulphate of iron & cyanide of
potassium or sodium are produced in proportion to the amount of sulphur
cyanide used, such reaction is readily effected, and is ascertained to be complete
when the matter in the crucible being diluted by a little water gives a solution
which has no longer a blood red heat imparted to it by the iron salts. If
it is intended to prepare simple cyanide the product of the solution is treated,
after the complete cooling by cold water, the filtered solution is then evaporated
till by cooling it becomes crystallized, or it is evaporated till dry, and the
product obtained is dissolved. If a prussiate is to be obtained, the solution
of the melted mass is treated by spathic iron in the usual manner, or it is

page_text: simply left to digest on the residue of sulphide of iron; when the liquor is
sufficiently saturated with iron it will suffice to have it evaporated at 25° of
the salt meter, when cold, beautiful crystals will be formed thercon quite
similar to those now obtained. I deem it useless to describe these two opera-
tions more minutely which present no particular features, and which are
perfectly well known, and the same remark may be made as regards the other
compounds. The new method of forming alkaline cyanides by means of
sulpho-cyanides or like bodies being the chief of my Invention, I do not claim
such other preparations of cyanogen which are not obtained with cyanides
treated by means of my improved process, which, however complicated it may
appear theoretically, is indeed limited to a few simple operations which are the
following:-
1st, preparing ammoniacal sulpho-carbonate under cheap conditions.
2ndly, transforming quickly sulpho-carbonate into sulpho-carbamate of
ammonia and sulpho-cyanide.
3rdly, transforming such sulpho-cyanide of ammoniac into sulpho-cyanide of
potassium or sodium.
4thly, transforming alkaline sulpho-cyanide into cyanide of a similar base..
Alkaline sulpho-cyanide has been hitherto produced accidentally in common
manufacture, and chiefly as a consequence of the impurity of the rough matters
which were made use of, its presence being looked upon by manufacturers as
a grave inconvenience, & as the principal cause of the deterioration of the
apparatus, and therefore their constant endeavours tended to prevent its
formation; but by my system it becomes, on the contrary, the base of the
operations. I do not confine myself to the whole of the reactions above
described, but I also claim each of them particularly, for none to this day have
been applied to the special purpose, nor to any purpose in the same conditions
I have realized for them; consequently I claim the exclusive right of pre-
paring prussiates by means of sulpho-cyanides or equivalent bodies, whatever
may be the source they are derived from, and whatever the manner in which
ammonia is brought in relation with the sulpho-carbonated body in order to
produce them, for I intend to make use of not only artificial sulpho-cyanides
of my preparation, but also of such as exist accidentally in certain residues
hitherto unemployed; and although I intend to make use of such residues
whenever I can get them, yet I consider them as merely an auxiliary supply,
which may frequently fail me, 1st, because they might be one day or other
utilized for some new applications; 2ndly, because the amount of such residues.
is insufficient to supply an important branch of manufacture. The residues
upon which I have made numerous experiments are supplied by gasworks;

page_text: they are liquids rich in calcareous salts and sulpho-cyanides which have been
neglected to this day, or have been thrown away together with the waste
waters, to the great detriment of health. Sulpho-cyanides of gas are found
either in ammoniacal water, the direct product of the distillation of coal, or in
liquors resulting from the washing of refining matters, viz., oxide of iron and
manganese, and calcareous or metallic chlorides & sulphates, the latter source
being the most abundant. Sulpho-cyanide is formed in the uncrystallizable
mother waters of chloride and ammoniacal sulphate, which mother waters are
of variable natures, and may contain sulpho-cyanide in several states, viz.,
with a base of ammonia, lime, iron, or manganese. Whatever may be the
nature of the base, the following is the manner in which I treat them:-The
mother waters are evaporated in a boiler till when cold they become crys-
tallized; they are left in this state to deposite in vessels of small size the most
part of the chloride and ammoniacal sulphate which they may still retain.
After this first treatment the liquids are poured into a distilling apparatus
with a solution of lime somewhat in excess; the whole ammonia left in the
mother water is afterwards separated in the form of caustic, and serves for the
manufacture of artificial sulpho-cyanides. The liquid in the boiler contains after
this treatment by lime sulpho-cyanide of calcium and chloride of calcium in
variable quantities. There now only remains to transform calcareous salts into
salts of potash or soda. I have found by experience that such transformation
is most easily effected by means of potash, or caustic or carbonated soda, or
rather the sulphates of those alkaline bases are poured into the liquid heated
from 80° to 90° centigrade. In all these cases it is necessary to operate in a
heated state, the calcareous precipitate being more aggregated under these
conditions will be readily separated from the liquid which is submitted to a first
crystallization: the alkaline chloride and sulphate are separated first; then,
by way of concentration, the crystals of sulpho-cyanide are obtained, which
are treated by the above described process in order to be transformed into
cyanides or prussiates, thus the process which is the object of my present
application for Letters Patent supplies residues. the amount of which is too
considerable to be neglected. The residues are, 1st, sulphydrate of ammonia;
and, 2ndly, sulphide of iron. The use of those substances is very advantageous
and it would prove greatly beneficial to annex to a manufactory of cyanide &
prussiate a manufactory of hyposulphite of soda and alkaline sulphides. With
sulphide of iron I produce sulphuric acid, which, combined with sulphide of
sodium. produces hyposulphite of soda.
With sulphydrate of sulphide of ammonium I produce either alkaline
sulphides or a salt of ammonia, and also sulphur, by utilizing the well known

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Amedee Gelis in the Great Seal Patent Office on the 24th
January 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, AMEDEE
GELIS, of 29, Boulevart St. Martin, Paris. in the Empire of France. Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of July, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Amedee Gelis, Her special licence that I, the said Amedee Gelis, my exe-
cutors, administrators, and assigns, or such others as I, the said Amedee
Gelis, my executors, administrators, and 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
"IMPROVEMENTS
Man, an Invention for
Channel Islands, and Isle of
PREPARING COMPOUNDS OF CYANOGEN AND PRINCIPALLY OF PRUSSIATES BY MEANS OF
SULPHURETTED CARBAMIDES OR AMIDES, WHICH SUPPLY SULPHURETS OF CARBON BY
THEIR DECOMPOSITION," upon the condition (amongst others) that I, the said
Amedee Gelis, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, 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.
IN
NOW KNOW YE, that I, the said Amedee Gelis, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
My Invention relates to improvements in preparing compounds of cyanogen,
and principally of prussiates by means of sulphuretted carbamids or amids
which supply sulphurets of carbon by their decomposition.
I comprise under the above denomination sulpho-carbonates, amunoniacal

page_text: or metallic sulpho-carbamates, and sulpho-cyanides, which bodies only amer
from each other by the proportions of hydro-sulphuric acid they contain,-
Sulpho-carbonate, C'Sellar.
Sulpho-carbamate, C'S'H'ar-2HS = C'S'll'ar.
Sulpho-cyanide, C2S11'ar-411S = C*S*H*ar*.
The azote, heretofore entering into the composition of prussiate of potash, and
the different cyanic compounds made use of in trade, has been derived from
two sources, viz., atmospheric air and animal residues, such as wool, leather,
hair, horns, and others. One method which is employed, and called the
English process, from its having been alone realized in England, consists in
causing quantities of air to pass through piles of charcoal impregnated with
potash & highly treated. This process requires a considerable expense of fuel,
and for this reason was never adopted commercially in France, although of
French origin. The second process, which supplies the French market
exclusively with cyanides and prussiates, consists in varying infinitely the
proportions of matters made use of, and in the manner of working or decom-
posing the animal substances above mentioned, by means of carbonates
sulphates, or sulphides of potash and soda raised to a high temperature, with
or without the addition of lime or of ferruginous compounds.
My improved process, for which I apply for Letters Patent, is based upon
a system of reaction quite different to the above. I do not derive azote either
from air or animal matters, but from a manufactured compound, viz., ammonia.
1 fix this ammonia by means of sulphuret of carbon, and I prepare with these
two products suitably combined, sulphuretted amids, or I derive such sulphu-
retted amids from certain residues heretofore unemployed, and, finally, I
transform such amids into sulphuretted amids of potassium and of sodium,
which sulpho-cyanides, being afterwards modified by an appropriate metal.
such as iron, zinc, copper, lead, and others, are converted either into prussiates
of potash or soda, or cyanides of potassium or sodium.
I first prepare sulpho-carbonate of ammonia (the latter in excess) by the direct
action of a mixture of mono-sulphuret of ammonium, & of caustic ammonia,
in a concentrated solution with sulphuret of carbon. This preparation, which
appears simple at first, presents, however, some difficulties, inasmuch as
sulphuret of carbon and the concentrated solution of sulphuret of ammonium,
being two liquids of different densities, and which will not combine except
after a continuous agitation in order to mix them together, which, for com-
mercial purposes, is not an easy matter to effect. This difficulty of contact is
an obstacle to the combination, and would require too much time for practical
purposes, to obviate which I apply means by which this first part of the

page_text: operation is much simplified. This consists in adding to the mixture of the
liquids fatty bodies in small quantities. any oil for instance, added in the
proportion of one to three per cent. of the weight of sulphuret of carbon.
This small amount of oil, on meeting an excess or surplus of ammonia, is
saponified, and thus becomes an emulgent by which the mixture is converted
into an opaque gelatinous mass, in which the two reactive substances are
equally distributed. In these conditions the reaction is very rapid, and the
combination is effected in a few hours, which is ascertained by the mixture
becoming limpid, & a homogeneous transparent liquid is obtained, of a most
beautiful, somewhat reddish. yellow color.
The soap or fatty body remains
floating on the surface, and may be easily decanted and made use of for sub-
sequent operations. I have found that the employinent of oil to effect the
reaction will answer perfectly. but the part assigned to this substance is purely
mechanical, it may be replaced by refined oil, by certain heavy oils produced
in the distillation of organic matters, such as wood schists, bitumen, wood,
and other substances by means of wood spirit and alcohol; these bodies act
either as emulgents or solvents of the principal products. The question of
economy in the application will form a guide in the particular use of one or
other of these substances.
The
I effect the above combination of sulphuret of ammonia and sulphuret of
carbon in a sheet-iron cylinder, provided at its lower part with a stop cock
which serves for decanting the liquid when the operation is finished.
cylinder is suspended at its centre on two double supports, which permit of a
rocking motion being imparted thereto. It is fed with the liquids to be mixed
through a socket at its lower part. The sulpho-carbonate being thus prepared
Now I have ascertained that it
other transmutations may then take place.
suffices to raise the foregoing combination to ninety or one hundred degrees
centigrade, in order to convert it into sulpho-carbamate, and ultimately into
In the meantime that the said
sulpho-cyanide with a base of ammonium.
compounds are produced a considerable amount of sulphydrate of sulphuret of
ammonium, & also mono-sulphuret of ammonium is disengaged by reason of
The
the large excess of ammonium employed to facilitate the reaction.
decomposition of the ammoniacal sulpho-carbonate above described is easily
effected, both on a large and small scale, whether the heating is direct or by
means of a water bath, or a current of steam, or superheated steam be injected
into the liquid. I thus obtain, on the one hand, in the boiler a colorless, or but
slightly colored liquid, containing only sulpho-cyanide of ammonium, the
treatment of which I will explain herein-after, and sulpho-hydrate of sulphuret
of ammonium, & monosulphuret on the other hand, which is distilled and

page_text: received in the form of vapour in sheet-iron boxes with compartments con-
taining ammonia; thus at the end of the operation is produced mono-sulphuret
with an excess of ammonium, or exactly the very salt that was employed at
the starting point. The solution is mixed as previously with a fresh quantity of
sulphuret of carbon in the rocking cylinder, and the operation being carried on
again as before will yield a fresh supply of sulpho-cyanide of ammonium, and so
forth indefinitely.
It is here necessary to observe that the amount of sulphurct of ammonium
obtained at the end of the operation is more considerable than that which was
employed at the beginning, hence, notwithstanding the various losses which
cannot be prevented, an abundant supply of this salt may be obtained, and the
sulphuret of carbon can always be treated by a more considerable amount of
sulphuret of ammonium than that theoretically indicated, which surplus will
render the reaction much easier without increasing the cost of the process, and
in consequence of the accumulation of this salt, I will. when treating of residues,
state what may be done therewith; I will also presently refer to the colorless
solutions left in the alembic boiler, and which contain sulpho-cyanide of am-
monium; first, the ammoniacal salt therein contained is transformed into salt
of potash or soda, otherwise they could not easily be evaporated without being
partly destroyed, such transformation may be obtained directly, or the ammo-
niacal salt may be converted, first into calcareous salt, which has the advantage
of allowing of the use of sulphates, which saits are cheaper than carbonates or
sulphurets. First, I ascertain by a mixture of a small quantity, the amount of
sulpho-cyanide contained, then taking as a base the whole known volume, I
mix it in the boiler with a solution containing an equivalent quantity of mono-
sulphuret of potassium or sodium, or of carbonate of potash, or of soda, required
for effecting the transformation. This being done, I close the boiler and heat
it again as before; a double decomposition is now produced, the base of
sulpho-cyanide is changed, and a fresh amount of mono-sulphuret of ammonia
is evolved; which becomes condensed in the sheet-iron boxes, and superadded
to the quantity of this salt already obtained; the operation is complete when
steam alone is seen to distil. The apparatus is then uncovered or the liquids
decanted into a basin provided at its lower part with an agitator, in which the
concentration is completed; this concentration is easily effected, and presents
no particular feature so long as the liquids have not reached a certain degree
of concentration, and the temperature does not exceed one hundred degrees, for
when evaporation commences at a somewhat higher temperature, and while
the liquids are still aqueous, the sulpho-cyanide will show some symptoms of
decomposition. Evaporation is completed when a drop of the liquid poured

page_text: over a cold body will instantly form a crystalline bubble, and being left to rest
in this state it will yield fine crystals which are easily dried. To deprive these
crystals of the sulphur, which consists of sulpho-cyanide of potassium they con-
tain, & to transform them into simple cyanides, I mix together one hundred
parts of dried crystals and sixty parts of cast iron, or preferably of wrought-
iron cuttings.
I place this mixture by small portions in a cast-iron crucible previously
heated to redness. The mass directly melts, and is afterwards formed into
sulphuret of iron, and cyanide of potassium or sodium, according to the amount
of sulpho-cyanide employed. Iron cuttings and filings may be substituted with
advantage for the iron, which are reduced by hydrogen in a crucible and
muffle of iron or cast iron, with a very flat dome. Under these conditions I am
enabled to prepare in the same space of time much larger quantities of material
at a lower temperature than before. which will obvinte the deteriorations well
known in the ordinary preparation of sulpho-cyanides. Such reaction is readily
effected, and is ascertained to be complete when the matter in the crucible
being diluted by the little water gives a solution which has no longer a blood
red color imparted to it by the salts of iron. If it is intended to prepare simple
cyanide the product of the solution is treated after complete cooling by cold
water, the filtered solution is then evaporated, till by cooling it becomes crys-
tallized, or it is evaporated till dry, & the product obtained is melted in a
crucible. If a prussiate is to be obtained, the solution of the melted mass is
treated by spathic iron in the usual manner, or it is simply left to digest on
the residue of sulphuret of iron; when the liquor is sufficiently saturated with
iron, it will suffice to have it evaporated at twenty-five degrees of the salt meter
which, when cooled, will form beautiful crystals, similar to those now obtained.
In the preparation of simple cyanides, it happens sometimes that the particular
state of mixture resulting from the fusion of sulpho-cyanide with iron, especially
if reduced iron is made use of, which does not permit of withdrawing with the
water the alkaline cyanide of sulphuret of iron with which it is mixed, the
transformation to prussiate being instantaneous; I then make use of the dis-
solving action of liquids other than water, such as alcohol, for example, wood
spirit, certain volatile products of commerce produced by the action of heat on
various organic matters, in fact, of hydrates and volatile bydrurets of carbon,
serving as a vehicle for the alkaline cyanides, the separation of this vehicle
being afterwards effected in the ordinary way.
It is unnecessary to describe these two operations more minutely, which
present no particular features from the time of the formation of the cyanide,

page_text: and the same remark may be made as regards the other compounds of
cyanogen.
The new method of forming alkaline cyanides by means of sulpho-cyanides
or like bodies being the chief object of my Invention, I do not claim such
other preparations of cyanogen which are obtained with cyanides treated by
means of my improved process, which, however, complicated it may appear,
theoretically, is indeed, limited to a few simple operations, which are the
following: First, preparing ammoniacal sulpho-carbonate under cheap con-
ditions. Secondly, transforming quickly sulpho-carbonate into ammoniacal
sulpho-cyanide. Thirdly, transforming such ammoniacal sulpho-cyanide into
sulpho-cyanide of potassium or sodium. Fourthly, transforming alkaline
sulpho-cyanide into cyanide of a similar base.
Alkaline sulpho-cyanides have been hitherto only produced accidentally in
the manufacture of prussiates, and chiefly as a consequence of the impurity of
the rough matters which were made use of, their presence being looked upon
by manufacturers as a grave inconvenience, and as the principal cause of the
deterioration of the apparatus. and, therefore, their constant endeavours
tended to prevent its formation; but by my system it becomes, on the contrary,
the base of the operations. I do not confine myself to the whole of the
reactions above described, but I also claim each of them particularly, for none
to this day have been applied to the special purpose, nor to any purpose in the
same conditions I have realized for them. Consequently, I claim the exclusive
right of preparing prussiates by means of sulpho-cyanides or equivalent bodies
whatever may be the source they are derived from, and whatever the manner
in which ammonia or azote is brought in relation with the charcoal and
sulphur in order to its production, for I make use not only of artificial sulpho-
cyanides, either prepared or existing accidentally, in certain residues hitherto
unemployed, and although intend to make use of such residues, yet 1
consider them as merely an auxiliary supply, which sometimes fails me.
Because the amount of such residues is insufficient to supply an important
branch of manufacture. The residues, upon which I have made numerous
experiments, are supplied by gasworks, they are liquids rich in calcareous salts
and sulpho-cyanides, which have been neglected to this day, or have been
thrown away with the waste waters to the great detriment of health. Sulpho-
cyanides of gas are found either in ammoniacal water, the direct product of
the distillation of coal, or in liquids resulting from the washing or refining
matters. viz., oxides of iron and manganese, calcareous or metallic chlorides,
and sulphates. The latter source being the most abundant, sulpho-cyanide is

page_text: formed in the uncrystallized mother water from which sulphate and ammoniacal
chloride has been obtained, which mother waters are of variable natures, and
may contain sulpho-cyanides in several states, with a base of ammonia, lime,
iron, or manganese. Whatever may be the nature of the base, the following
is the manner in which I treat them:-The mother waters are evaporated in
a boiler till cooled, when they become crystallized; they are left in this state
to deposit in vessels of small size a small quantity of the chloride or sulphate
with a base of ammonia which they may still retain. After this first treatment
the liquids are poured into a distilling apparatus with a solution of milk of
lime somewhat in excess, the whole ammonia left in the mother waters is
afterwards separated in a caustic form, and serves for the manufacture of
artificial sulpho-cyanides. The liquid in the boiler contains after this treatment
by lime sulpho-cyanide of calcium and chloride of calcium in variable quantities.
There now only remains to transform calcareous salts into salts of potash or
soda.
The chloride of ammonium being first separated by crystallization to
diminish the quantity and prevent the mixture of too large a quantity of potash
in the operation which follows. I have found by experience that such trans-
formation is most easily effected by means of potash or caustic, or carbonated
soda. or rather the sulphates of those alkaline bases are poured into the liquid
heated from eighty to ninety degrees. In all these cases it is necessary to
operate in a heated state. the calcareous precipitate being more aggregated
under these conditions, will be readily separable from the liquid, which is
submitted after filtration and evaporation to a first crystallization. The
alkaline chlorides and sulphates are separated first, and the crystals of sulpho-
cyanide are then obtained by concentration, which are treated by the above
described process in order to be transformed into cyanides or prussiates.
Thus the process which is the object of my application for the present
Letters Patent, supplies residues, the amount of which is too considerable to
be left unutilized. In my improved process sulphur does not form part of the
final product of the above-described operations, it being only the vehicle for
the carbon and azote in the action of sulphuret of carbon on the sulphur of
ammonium; the half of the sulphur is converted into sulpho-cyanide, the
second half uniting with the hydrogen of ammonium is eliminated in the form
of sulphydrate of ammonia; one part of this sulphydrate of ammonia forms
part of the excess remaining to be utilized; on the other hand. the treatment
of sulpho-cyanide by iron-produces sulphuret of iron. These residues, are first,
sulphydrate of ammonia; secondly, protosulphuret of iron. The use of those
substances is very advantageous, and it would prove greatly beneficial to annex

page_text: to a manufactory of cyanide and prussiate a manufactory of hyposulphide of
soda and alkaline sulphurets.
Preparation of hyposulphite of soda with the residues of the manufacture of
prussiates. In this preparation two residues are employed; with sulphuret of
ammonia I produce sulphuret of sodium, with sulphuret of iron I produce sul-
phurous acid, which, combined with the sulphide of sodium, furnish hypo-
sulphide of soda and sulphur in the proportions as follows:-
2Sna+CSOS + SO2, naO.
The following is the manner of operating: I transform the sulphuret of
ammonia into sulphuret of sodium by distilling it with caustic soda or car-
bonate of soda; I thus obtain ammonia or carbonate of ammonia which enter
into the manufacture of cyanides and sulphuret of. sodium in solution; I
evaporate this solution until it forms into a mass by cooling; I divide this
cooled mass into blocks, which I superpose on a column of wood of about four
yards in height; this column is placed by means of two cross bars on a leaden
vessel, and communicates by cast-iron pipes with a furnace, in which I produce
sulphurous acid by roasting the residues of sulphuret of iron. To facilitate this
roasting. I take care to prepare the blocks with sulphuret. The hyposulphite
first forms in the column, and flows into the vessel as the blocks of sulphuret
contain a sufficient quantity of water to keep the hyposulphite in solution.
After the manufacture of hyposulphite, colcothar alone remains as residue,
which may be utilized or not. according to circumstances. It may also be
employed in the preparation of reduced iron, necessary for the desulphuration
of sulphocyanide.
Preparation of sulphurets with the same residues. In certain cases the
sulphydrate of sulphuret of ammonia may be directly utilized. such as in the
preparation of aniline, which every day becomes more extensive. Hence a large
quantity of sulphur from the residues of sulphuret of ammonia may be applied
in the form of sulphydrate of soda, or at times, sulphur.
I will now in conclusion describe a method of employing my residues, based
on a totally different principle to those herein-before described for the produc-
tion of sulphur and caustic ammonia. It is well known in chemistry that
hydrated peroxide of iron has the property of giving up with the alkaline
sulphurets and specially sulphur of ammonia, the alkali of the salts employed.
and a black sulphuret of iron, which, after Berzelius, corresponds with peroxide
fe S³+aq.
It is also known that this hydrated sulphuret, when exposed to
the open air absorbs the oxygen, the sulphur being displaced, and the primitive
oxide of iron regenerated. It is this reaction, indicated by Berzelius, which I

page_text: have profited by. Without describing the apparatus, the form of which has
no influence on the action, I will only mention that the operation is effected
by pouring the sulphydrate in the cylinder. having a cock at its lower part,
and filled with hydrated peroxide of iron, deposited in layers. This oxide, to
permit of the easy passage of the liquid, may be subdivided by an inert matter.
such as an oxide mixed with sulphur resulting from former operations, sawdust.
or other bodies, provided they have no influence on the products. After its
passage over the oxide, the liquid which runs from it consists of caustic am-
monia. The ammonia which impregnates the matters in the cylinder is
removed by means of water, and the sulphur is exposed in the open air, or it
is caused to traverse a strong current of air. The oxidation will be actively
produced by elevating the temperature when the desulphuration is complete..
which is ascertained by the water changing from a black to a red color. The
operation may be again repeated in the cylinder by using the oxide reproduced:
There will always happen a time when a large quantity of sulphur mixed with
oxide of iron renders the latter inactive, which mixture may then be utilized
either for the preparation of sulphurous acid by roasting, or for the direct
extraction of the sulphur by heat and liquefaction, or which is better, extract-
ing by employing the sulphuret of carbon, is a solvent, in a closed apparatus
arranged for the purpose, and separating the products by distillation.
In witness whereof, I, the said Amedee Gelis, have hereunto set my
hand and seal, this Fifteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-one.
A. GELIS. (L.S.)