IMPROVEMENTS IN MAKING THE OYANIDES AND TERRO-CYANIDES OF POTASSIUM AND SODIUM
Year: 1845

page_text: LAMING'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
LAMING, of Mark Lane, in the City of London, Merchant, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Eighteenth day of November, in the ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto the
me,
said James Laming, Her especial license, full power, sole privilege and
authority, that I, the said James Laming, my executors, administrators,
and assigns, and such others as I, the said James Laming, my executors
administrators, 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 mentioned
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, and in all Her Majesty's
Colonies and Plantations abroad, and in the Islands of Jersey, Guernsey,
Alderney, Sark, and Man, an Invention of "IMPROVEMENTS IN MAKING THE
OYANIDES AND TERRO-CYANIDES OF POTASSIUM AND SODIUM," being a communi-
cation from abroad; in which said Letters Patent is contained a proviso
obliging me, the said James Laming, by an instrument in writing under
my hand and seal, particularly to describe and ascertain the nature of the
said Invention, and in what manner the same is to be performed, and to cause
the same to be enrolled in Her Majesty's High Court of 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Laming, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof (that is to say):
Before describing the improvements for the Invention of which this Patent
has been granted, and as communicated to me from abroad, I will, for their
better elucidation; detail the chemical facts or principles upon which they
are founded. These are as follows:-
First, when animal matter which contains nitrogen as well as hydrogen and
carbon is exposed to a high temperature not exceeding low red, an equivalent
of nitrogen combines with three equivalents of hydrogen to form an equivalent
of ammonia, and the carbon is separated.
Second, when ammonia is exposed to carbonata full red heat, an equivalent
of ammonia exchanges two of its equivalents of hydrogen for two equivalents
.of carbon, and thus becomes prussic or hydrocyanic acid.
Third, if free potassium or sodium be also present, the equivalent of
ammonia parts with all its three equivalents of hydrogen, and the nitrogen
which remains takes in their place two equivalents of carbon to form cyanogen,
and one equivalent of potassium or sodium, as the case may be, to form a
oyanide of the metallic base.
Fourth, when animal matter is exposed to heat, its temperature becomes
gradually elevated to low redness before it assumes that higher temperature
indicated by a full red colour; therefore whenever animal is subjected to what
is called destructive distillation, the formation of ammonia must take pre-
cedence in point of time to that either of prussic acid or of the cyanides.
Fifth, when the oxide of potassium or of sodium, or the carbonate of either
of those oxides, is intimately mixed with carbon and exposed to a heat
approaching to whiteness, its metallic base is set free from the oxygen with
which it was previously combined and rises in vapour. If ammonia come
into contact with the mixture of carbon and alkali, or of carbon and alkaline
carbonate, the separation of the metallic base from its oxygen takes place at
a lower temperature under such circumstances, a full red heat being sufficient.
In the case of the carbonates, the metallic bases, potassium and sodium, are
liberated from the carbonic acid also whenever they separate from their oxygen.
Sixth, cyanide of potassium or cyanide of sodium, by exchanging an equiva
lent of every three equivalents of its base for an equivalent of iron, is converted
into the corresponding ferro-cyanide, or what is called in commerce prussiate
of potash or prussiate of soda, and this change may be effected by causing
the cyanides of the respective metals dissolved in water to come into contac

page_text: with iron, or oxide of iron, in a state of division. The ordinary way or com-
bining potassium or sodium with cyanogen,preparatory to making the prussiate
of potash or prussiate of soda for commerce is, to expose in iron pots an
impure carbonate of one of those alkalies and animal matter to a red heat,
and to trust for the necessary contact of the nitrogen and carbon of the animal
matter with the metallic element to the thorough incorporation of the ingre-
dients of the pasty mass by stirring. While the temperature of the animal
matter is approaching redness, ammonia is constantly being generated, and as
it is volatile it escapes and is lost, and this continues until the heat becomes
great enough to convert the nitrogen and carbon of the animal matter into
cyanogen, and to fix that cyanogen by combining it with the metallic base of
the alkali. Another source of loss is the difficulty of causing the different
elements which are to combine to find each other out in the pasty mass, for
before each can be brought into contact with the other by mechanical agitation,
their temperature becomes elevated,and great part of the resulting nitrogenous
gases which are volatile have time to escape. There is a third evil attending
the ordinary process, namely, the proportion of carbon in animal matter, com-
pared to its nitrogen, is greater than that in the alkaline cyanides. The greater
part of this carbon, from its fixed nature, remains to solidify the mass from
which the nitrogen so freely escapes, so that it becomes necessary to suspend
the addition of the animal matter on account of the mass being too solid for
the chemical action to go on before enough of nitrogen had been combined
to convert much of the alkali into prussiate. Two Patents have been granted
for methods invented for preventing the losses sustained in the ordinary way
of making the prussiates of potash and soda. By one of those methods the
ammonia which is liberated from a heated mixture of alkali and animal
matter is conducted first over the surface of fused alkali, thesaid alkali having
no admixture of carbon, and afterwards into a vessel containing a solution of
alkali. The other of these methods directs that the ammonia which results
from animal matter exposed to heat be made to pass upwards and downwards
through a series of vertical pipes, arranged on the principle of inverted
syphons, heated to redness, and charged with a mixture of charcoal, potash,
and iron, reduced to small fragments. With regard to the former of these
methods, it is well known to chemists that fused alkali has no power of
decomposing ammonia into cyanogen, unless carbon be present; and with
regard to the latter method, it is obvious that as the materials, if brought into
a state of fluidity or pastiness, must of necessity choak the passage of the
pipes, the method demands that the mixture in the inverted syphons be kept
from losing its solid or granular state; and the continuance of that state is

page_text: secured by the large proportion of infusible charcoal compared to the fusible
potash which the Patentee prescribes as fulfilling his intentions in a satisfactory
manner. Now, by this Invention, I make use of charcoal or other form of
carbon in powder, mixed with one of the alkalies or its carbonate, or other
salt, capable, under the circumstances, of surrendering its metallic base to
cyanogen; and I maintain this mixture constantly in a fused state, so as to be
fluid, or at least in a pasty condition, which I find to be highly favorable to
the chemical reaction which converts the metallic base of the alkali or its salt
into a cyanide, and which takes place rapidly under such circumstances when
I introduce to the fused mixture a current of ammonia gas, either pure or
mixed with any other element or elements which do not prevent the desired
result. The metallic base of potash orsoda, or of their compounds respectively,
as the case may be, is liberated by the agency of the heated carbon, assisted
by the affinity of the metallic base for the cyanogen, which is at the same
time formed by the combination of heated carbon with the nitrogen of the
ammonia. Cyanide of the metallic base is thus produced, and this product is
constantly augmented in quantity (the current of ammonia being continued)
until great part of the alkali or other compound of its base has become con-
verted into cyanide. I have found when an alkaline carbonate is used, that
powdered charcoal, to the amount of more than thirty per cent. of its weight,
may be added without destroying the fluidity of the mixture when the
temperature is raised to a full red.
When the potash or soda is in a caustic
state, a larger proportion of charcoal may be added; or, what is more advan-
tageous, the mixture will remain fluid although the heat be raised not so
high. I prefer passing the ammonia gas through the mixture of carbon and
fused alkali, or other compound of its metallic base; but sometimes I
pass it
over its surface. In both cases it is better to have more than one vessel
charged with the heated materials, so connected together by pipes that the
nitrogen of the ammonia which escapes the chemical reaction in the first
vessel shall not pass through the whole series without combining. The
apparatus thus acts on the principle of a series of Woolfe's bottles; and in this
Invention all the vessels are made. red hot, except the last, into which I put
water, or some liquid convenient for arresting the vapours of alkaline metal,
which might otherwise be lost. The first product, as in the common process
for making prussiate, is a cyanide of the alkaline metal present, which may be
dissolved out from the mass technically called "metal" by boiling the latter
in alcohol of about 0-896 specific gravity, from which, filtered hot, it spon
taneously separates in great part on cooling. To obtain the ferro-cyanide the
"metal" is to be treated in the usual way, namely, the soluble parts dissolved

page_text: n water, then treated with iron, the solution evaporated, and when sufficiently
concentrated and clear. set aside to crystallize, and the rough product after-
wards purified by recrystallization.
I do not claim the Invention of any process for dissolving out or obtaining
either cyanide or ferro-cyanide from the compound termed "metal," nor do
I claim the Invention of any particular form or construction of apparatus
wherewith my process or processes may be carried on, but it will be useful to
One of these
describe some arrangements which I have found to answer.
consists of three iron air-tight covered pots, communicating with one another
in the manner of ordinary Woolfe's bottles; (that is to say,) the induction pipe
of the first pot reaches to near its bottom, its eduction pipe reaches to near
the bottom of the second pot to form its induction pipe, the eduction pipe of the
second pot terminates in like manner in the third pot, while the eduction pipe.
of the latter plunges beneath the surface of some water or other liquid con_
venient for oxidizing and arresting vapours of alkaline metal. Each of the
covered pots has a man-hole in its cover, by means of which it may be charged
and discharged, and a door by which it may be perfectly closed. Each covered
pot is so set in a furnace as to be heated to a temperature great enough to
keep its contents in a state of constant fusion; its charge, when fused, should
about half fill it. By the use of this apparatus the ammonia which is forced
into the first pot, by reason of its own elasticity under the pressure attending
its assumption of the gaseous state, passes through the fluid mixture of fused
alkali and carbon in that pot, being there decomposed into nitrogen or cyanogen,
and as cyanogen combining with and saturating the alkaline metal present;
after which the ammonia or its nitrogen, or uncombined caynogen which
results from its action on the carbon still remaining in that pot, passes into
the second pot to convert the alkaline metal there present into a cyanide; in the
like manner, the ammonia or its nitrogen, or the resulting cyanogen, may arrive
in the third pot; then is the time for stopping the operation, in order that the
two first pots may be emptied and recharged. Owing to the volatility of the
alkaline metals at high temperatures, the pipes of communication between the
pots are apt to become obstructed; for this reason I have them made straight
and joined together at right angles in such a manner that by removing a screw
plug from the end of each rectilinear piece, I am enabled to clear the passage
through it by passing into it a short rod of iron. In order that this process
need not be often repeated, the diameter of the pipes should be as great as
convenience admits of.
I will now describe a modification of the preceding apparatus which
is useful in cases where it is desirable to do without the pressure necessary

page_text: to overcome the resistance opposed to the current of ammonia by the
fluid mass into which the eduction pipes of the preceding apparatus are
immersed. In this modification all the induction pipes stop short at the covers
of the pots, except that of the open pot, which may be allowed, without much
inconvenience, to dip below the surface of the water or other liquid intended
to arrest the metallic vapours. The ammonia gas, in this case urged forward
by an inconsiderable amount of pressure, comes into contact with the surfaces
of the fused ingredients in the several pots in succession until it is either
decomposed and its nitrogen absorbed, as in the preceding case, or escapes by
the last eduction pipe of the series, to prevent which either the number of
pots may be increased, or, what is better, each of the three should be furnished
with agitators moved by machinery or labour. When the latter arrangement is
adopted each pot should be furnished with a lofty conical cover, containing at
its apex a stuffing box, in which the axis of the agitator turns, and which is kept
sufficiently cool by a stream of water running through a small cistern which
embraces the stuffing box. With this apparatus the fused ingredients may be
either in a fluid, semi-fluid, or pasty condition. These descriptions of appa-
ratus will suffice to shew how this Invention may be put into practice; and it
is hardly necessary to add, that apparatus in great diversity may be devised to
carry out the same intentions more or less efficiently.
I claim as the invention, for which this Patent has been granted, the making
of the cyanides and ferro-cyanides of potassium and sodium, or, as they are
called in commerce, prussiates of potash and soda, in any suitable apparatus,
by passing ammonia (either pure, or mixed with such other gases as do not
prevent the desired result,). over the surface or through the mass (according as
the induction pipes may dip or not below the surface) of potash or soda, or
other compound of potassium or sodium capable, under the circumstances, of
setting free its metallic base in a state of fusion by heat, and mixed with
charcoal or other form of carbon in powder, and in such proportion as to be
adequate to effect, without destroying by its bulk, the fluid, semi-fluid, or pasty
condition of the resulting mass.
And I further claim, for the process or processes of this Invention, the sole
use of ammonia, or mixture or combination of ammonia with other gases
or vapours, whatever be the source from which it is obtained, provided always
that in such mixture or compound there be no substance present capable
by its nature of preventing the desired result. For example, I claim the
application to this Invention of ammonia, or carbonate of ammonia, obtained
from gas water, from urine, from the liquor condensed in the distillation
of bones or other animal matter, or from one or other of the salts of ammonia,

page_text: or a solution of ammonia, and also the ammonia, or carbonate of ammonia,
which is obtained directly mixed with other gases in the carbonization of bones
and other animal matters, and in the chemical treatment of guano. Whatever
be the source from whence the ammonia is obtained, it is desirable it should be
made as free from the vapour of water as possible before it is introduced to the
fused materials. For this purpose the substances from which it is to be
eliminated may be dried, or else the ammonia may be passed in an elastic state,
in contact with some substance known to chemists to be convenient for dessi-
cating that gas. Instead of obtaining the ammonia by a separate process, or
from a distinct vessel, I sometimes cause it to be given off from animal
matter contained in the vessel or vessels in which the cyanide is formed.
For this purpose it is better to use the potash or the soda in a caustic
state, causing it, while in that condition, to dissolve the animal matter. The
following is the mode of proceeding-A caustic solution of alkali in water or
other convenient liquid is first made boiling hot, and to it, while boiling, as
much animal matter is added as it will readily dissolve. The solution is next
When a
evaporated to dryness, and the mass preserved in that state for use.
portion of this mass is put into each of the heated vessels, except the last of
such a series as I have described, and the last heated vessel be charged with
carbon mixed with some convenient compound of an alkaline metal, as before
stated, then the ammonia which escapes from any one of the vessels in the
series will have to pass through one or more subsequent vessels, and thus tend
to suffer decomposition, the resulting nitrogen being converted into cyanogen,
and then being absorbed. This enables me to use the cheaper kinds.of
animal matter, such as the undried flesh and viscera of carrion, and old
woollen flock and rags, which, by reason either of humidity or too great volume,
cannot conveniently be mixed in their natural state with red-hot alkali. I
claim, therefore, this modification of the process as part of the Invention for
which this Patent has been granted. Or sometimes I put the mass resulting
from the dessication of the solution of animal matter in caustic alkali into red-
hot open pots. In this case much ammonia is lost, but the improvement
which is introduced by replacing the ordinary mechanical admixture by an
intimate chemical combination, affords me a greater product in prussiate than
can be obtained from an equal quantity of animal matter treated in the
ordinary way.
In witness whereof, I, the said James Laming, have hereunto set my
hand and seal, this Sixteenth day of May, in the year of our Lord
One thousand eight hundred and forty-six.
JAMES (L.s.) LAMING.

page_text: AND BE IT REMEMBERED, that on the same Sixteenth day of May, in
the year above mentioned, the aforesaid James Laming came before our Lady
the Queen in Her Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained, in form above written. And also
the Specification aforesaid was stamped according to the tenor of the Statute
in that case made and provided.
Inrolled the Eighteenth day of May, in the year above written.