IMPROVEMENTS IN PURIFYING GAS, IN OBTAINING MATERIALS USEFUL FOR THAT PURPOSE, AND IN WORKING UP INTO USEFUL PRODUCTS CERTAIN AMMONIACAL AND PHOSPHATIC SUBSTANCES OBTAINABLE AS RESIDUES IN THE PURIFYING OF GAS
Year: 1857

page_text: LETTERS PATENT to Richard Laming, of Haywards Heath, Cuckfield; in
the County of Sussex, for the Invention of "IMPROVEMENTS IN PURIFYING
GAS, IN OBTAINING MATERIALS USEFUL FOR THAT PURPOSE, AND IN WORKING
UP INTO USEFUL PRODUCTS CERTAIN AMMONIACAL AND PHOSPHATIC SUBSTANCES
OBTAINABLE AS RESIDUES IN THE PURIFYING OF GAS."
ealed the 21st July, 1857, and dated the 3rd February 1857.
PROVISIONAL SPECIFICATION left by the said Richard Laming at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
February 1857.
I, RICHARD LAMING, of Haywards Heath, Cuckfield, in the County of
Sussex, do, hereby declare the nature of the said Invention for "IMPROVEMENTS
IN PURIFYING GAS, IN OBTAINING MATERIALS USEFUL FOR THAT PURPOSE
AND IN WORKING UP INTO USEFUL PRODUCTS CERTAIN AMMONIACAL AND PHOSPHATIC
SUBSTANCES OBTAINABLE AS RESIDUES IN THE PURIFYING OF GAS," to be as
follows:-
One of the residues to be obtained in the purification of gas contains phos-
phate of ammonia. I decompose phosphate of ammonia by heat, and thus
obtain the base of the salt, and then I afterwards separate the base of its acid
in the usual way. Another of the objects of this Invention is to make the
obtaining of ammonia from gas directly subservient to the production of
peroxide of iron, which is applicable for the thorough purification of gas from
sulphuretted hydrogen by means either of the revivifying or the catalytic
[Price Sd.]

page_text: processes, both first invented and introduced by me, the former in September
1848 and February 1849, and the latter in 1852. I secure this object by com-
bining two operations, first, the washing of impure gas with a solution of a salt
of iron, to produce a fixed salt of ammonia in solution, and also a magma
containing precipitated sulphuret of iron, and, secondly, the peroxidation of
the magma so obiained by exposing it to air after having dried it sufficiently
to make it pervious, or mixed it with porous materials. I thus produce the
new and useful result of making the extraction of ammonia from gas by means
of a salt of iron sufficiently economical to be undertaken for the sake of its
products, which has not heretofore been the case, as the whole expense of the
salt of iron has had to be set against the ammoniacal compound formed with
its acid constituent the magma having been thrown away as useless. When
this part of the invention is used, it is advantageous to perfect the purification
of the gas from sulphuretted hydrogen by peroxide of iron, as it may thus be
done almost without cost, and ultimately to pass the gas through lime to deprive
it of carbonic acid, and to afford a spent material in suitable condition and
quantity to serve as luting for the retort lids. Another object of this Invention
is to make the ammonia of the gas combine more extensively with its carbonic
acid, and then to extract the two impurities together in a state of concentrated
solution. For this purpose I purify the gas from its sulphuretted hydrogen
by means of oxide of iron, previously to the removal of its ammonia instead of
subsequently, or at the same time as hitherto practiced; the oxide by holding
back sulphuretted hydrogen sets ammonia free to combine with and render
very soluble nearly double its weight of carbonic acid; the gas, being then
washed with a small quantity of water, gives up the combined impurities in
the form of a concentrated solution, chiefly of sesquicarbonate of ammonia.
By the old processes of gas purification, the purifying, capabilities of most of
the ammonia naturally in the gas, when it enters what are called the purifiers,
are either altogether lost (as when the gas is washed with dilute mineral acid),
or inefficiently expended in extracting either carbonic acid, not exceeding in
quantity a single equivalent, or else sulphuretted hydrogen, which admits of
being economically removed by oxide of iron. By the new process, one of
two impurities in the gas is made instrumental in removing to a much larger
extent than heretofore, and without cost, the other of them, and after so doing,
to present itself in a valuable and marketable form; while the remaining
impurity, namely, the sulphuretted hydrogen is cheaply removed by revivifiable
oxide of iron. Thus the present addition to my former inventions extends
economy to all parts of the purifying process. If there be more carbonic acid
in the gas than twice the weight of its ammonia, and the whole is to be

page_text: removed, I adopt one of two alternatives, either to use lime for extracting the
last traces of carbonic acid, and to employ the spent lime for luting, or to
increase by any available means the quantity of ammonia in the gas. I prefer
to do this by passing vapour of hydrosulphate of ammonia into the gas before
it arrives in the oxide purifiers, or by passing the same vapour through other
vessels charged with oxide of iron, by which it may be made caustic before
mixing with the gas. Hydrosulphate of ammonia may be readily obtained in
any gas works by means of an easy process which I have devised for that pur-
pose, and made public. The combined carbonic acid and ammonia may be
washed out of the gas after it leaves the oxide of iron purifiers in any manner
calculated to avoid the use of large quantities of water. A series of ordinary
scrubbers or washing vessels will answer the purpose, but I prefer to use a
single scrubber with diaphragms, for which I obtained a Patent, dated
February 20, 1856, or (in works, not furnished with an "exhauster," an
improved scrubber, the chief peculiarity of which is, that it combines the advan-
tages of an intermitting supply of water with those of a cullender, distributing
water by means of holes loosely plugged with nails or rivets; it may be divided
into several chambers, each furnished with a cullender, as above said. If there
be, in any case, inadequate apparatus for washing out from the gas the whole
of the volatile salts of ammonia which are consequent upon the action of the
oxide on its impurities, without using for that purpose an unprofitably large
quantity of water, I then cause the gas, on its leaving the last washing vessel,
to pass through solution of sulphate or other salt of iron, as already explained
with respect to the object of this Invention first described; when an intermit-
ting supply of washing liquid is required, I prefer to use the following means:---
I cause the liquid to flow in a regulated stream into a tank elevated above,
and properly connected by a large exit pipe with the top of the scrubber until
the tank becomes full; a pipe conveys the overflow into a bucket suspended to
one of the arms of a lever rocking on an axis placed below its centre of gravity
and supported by the edge of the tank, the other arm of the lever being
attached by a wire with a valve in the end of the pipe communicating with the
scrubber. The weights of the moveable parts are so adjusted, that when the
bucket is empty, the valve rests on its seat, but rises before the bucket
becomes filled. The filling of the bucket raises the valve, and thus makes an
open communication for the contents of the tank to enter the scrubber, which
communication is made more or less enduring by a small cock left more or less
open in the bottom of the bucket, through which its charge of liquid more or
less rapidly escapes, and thus allows the valve to raise the weight opposed to
it, and to regain its closed position.

page_text: Another principal object of this Invention is to enable gas manufacturers,
even in populous neighbourhoods, to work up gas liquors and washings with
all due regard to legislative enactments into a compound, which serves at once
as a ready source of sulphate or other salt of ammonia, and also of an oxide
useful for purifying gas. I accomplish this purpose by distilling the gas
liquors or washings into a solution of salt of iron until the latter be quite
decomposed, and then I evaporate the resulting product to dryness for con-
venient transport to other localities, or on the spot I separate and prepare
the oxide of iron and the ammoniacal salt by oxidation, decantation, and
evaporation.
In the purification of gas under this Invention, the oxide of. iron may be
used either catalytically, as described in the Specification of my Patent of
August 12, 1852, that is to say, by mixing with the gas before. its puri-
fication from sulphuretted hydrogen a volume of oxygen gas (either pure of
contaminated with any other substance that may be considered not- inadmis-
sible,) equal to the volume of sulphuretted hydrogen to be removed; in which
case the oxide purifier will need to be opened very seldom, or the oxide may
be used chemically with alternate revivification, in which case the revivification.
should always he commenced by forcing atmospheric air through the spent
oxide, the gaseous products being received into a solution of mineral acid, or
of sulphate or other salt, of iron in order to form the ammoniacal salt and pre-
cipitate already spoken of, and which may be treated as before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Laming in the Great Seal Patent Office on the 3rd
August 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, RICHARD
LAMING, of Haywards Heath, Cuckfield, in the County of Sussex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of February, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Richard Laming, Her special licence that I, the said Richard
Laming, my executors, administrators, and assigns, or such other's as I, the
said Richard Laming, my executors, administrators, and assigns, should at.
any time agree with, and no others, from time to time and at all times

page_text: 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 "Iм-
PROVEMENTS IN PURIFYING GAS, IN OBTAINING MATERIALS USEFUL FOR THAT PUR-
POSE, AND IN WORKING UP INTO USEFUL PRODUCTS CERTAIN AMMONIACAL AND
PHOSPHATIC SUBSTANCES OBTAINABLE AS RESIDUES IN THE PURIFYING OF GAS," upon
the condition (amongst others) that I, the said Richard Laming, 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.
NOW KNOW YE, that I, the said Richard Laming, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
When bone or other form of phosphate of lime is first acted upon by sul-
phuric acid, and then its phosphoric acid combined with ammonia, either
during the purification of gas or by other chemical means, phosphate of
ammonia is one of the results.
Part of this Invention consists in applying that phosphate of ammonia,
without separation from the earthy material in which it is formed, to the
manufacture of phosphorous; for which purpose I grind it with about half its
weight of charcoal or other efficacious form of carbon, and having dried the
mixture I submit it in earthen retorts to a temperature gradually raised to
bright redness. At first some ammonia, unless wholly driven off during the
drying, accompanied by other gases, comes from the retorts, and may be fixed
by a bath of sulphuric acid or other.known means. Before the phosphorous
begins to come over, I seal the ends of the eduction pipes by water, and
conduct the distillation and subsequent stages of manufacture in the ordinary
manner.
:
When gas is purified from ammonia by washing it with a solution of sul-
phate of iron, I combine the following means for obtaining from the residue
of the process both sulphate of ammonia and a material containing hydrated
peroxide of iron-When the sulphate of iron in the solution has been com-
pletely decomposed by the impurities of the gas, I let the residue flow into a
tank to settle, and having drawn off as much of the supernatent clear solution
as is obtainable after as many hours rest as can conveniently be allowed, I
well mix the thicker portion, which remains with two or three times its bulk

page_text: of water, and immediately run it into a large shallow sand filter, the sand
being covered with coarse sacking, and lying on similar sacking supported by
a layer of pebbles. I evaporate in any convenient manner the liquor which
runs from the filter, as well as that drawn from the precipitating vessel, in
order to obtain the sulphate of ammonia which they contain. A precipitate
will be left upon the filter, which is for the most part sulphuret of iron; I
incorporate it with as much ground unslaked lime, or magnesia, or both, as
will serve to absorb the remaining water, and thus make it more pervious to
the atmosphere, taking care not to let the mixture become either lumpy or
very hot. Sometimes instead of the substances above-named, I well mix with
the precipitate, first, about three times its bulk of dry sawdust, and then about
half its volume of dry slaked lime or magnesia, or both, or of dry powdered
carbonate of lime, carbonate of magnesia, or both, and when the mass has
thus been made more pervious to air, I leave it to oxidize.
When gas is purified in dry lime purifiers by materials containing hydrated
peroxide of iron, destined to be changed many times into sulphuret of iron
by abstracting its sulphuretted hydrogen, and to undergo alternate peroxida-
tion or revivification by mere exposure to the air (as first practised by me
and made known by my French brevet, specified in February, One thousand
eight hundred and forty-nine), it has been usual to remove from the gas its
hydrosulphate of ammonia, either as a preliminary measure or simultaneously
with the use of the oxide.
By the present Invention the opposite plan is adopted of introducing into
gas, about to be purified from sulphuretted hydrogen by iron in any state
which enables it to abstract that impurity and to undergo revivification
alternately, an additional quantity of hydrosulphate of ammonia. One of the
principal impurities to be removed from gas is carbonic acid, and it is well
known that all peroxides of iron are perfectly incompetent to remove it; it is
also true, that if the carbonic acid in gas could be combined with even less
than a full equivalent of ammonia it would be thereby entirely changed from
a very insoluble gas into a very soluble salt, and thus be easily removable by
a small quantity of water. Now, by mixing hydrosulphate of ammonia with
the impure gas, and introducing both together into the iron material, the
ammoniacal salt becomes decomposed, its sulphuretted hydrogen is fixed, and
its ammonia is set free to combine with and render soluble the carbonic acid.
Hydrosulphate of ammonia for this purpose may be obtained from any
known source, as for example, by exposing 10 a heat gradually raised to
redness, in retorts communicating with the induction pipe of the purifiers, a
mixture of carbonate of ammonia and sulphuret of sodium in about equivalent

page_text: proportions; or the gas on its way to the oxide purifiers may be washed with a
solution so strong of hydrosulphate of ammonia as to surrender it to the pass-
ing gas, instead of dissolving it out from the gas, as is the case when
ordinary gas liquor, which is comparatively weak in hydrosulphate, is used in
washers or scrubbers, for the purpose of being strengthened. The quantity of
hydrosulphate needed will of course vary with the kinds of coal or material
from which the gas is made, but the rule is to make it so large that the gas
on leaving the purifiers shall contain no carbonic acid that cannot be washed
out of it as a soluble salt by a little water, and if an excess be introduced it
will cause no inconvenience. The last traces of ammonia or ammoniacal salt'
may be washed out from the gas in any known manner. but I prefer in all
cases to use for that purpose the diaphragm scrubber, for which I obtained a
Patent, dated the Twentieth day of February, One thousand eight hundred
and fifty-six, or rather that improvement on it, which is hercin-after described,
and by means of which ammonia may be economized. Instead of water
washing, other known means for removing the combined ammonia and car-
bonic acid may be substituted with more or less effect, as for example, washing
the gas with solutions of sulphate of iron, but I prefer to use plain water.
This addition to the revivified oxide of iron process of purification is equally
applicable, whether the oxide material be used catalytically, as described in
the Specification of my Patent, dated the Twelfth day of August,
One thousand eight hundred and fifty-two, by introducing into the gas before
its purification a quantity of oxygen gas (either pure or mixed, as in atmo-
spheric air, if its nitrogen be not objected to for the injury it does to the
illuminating power). equal to the volume of sulphuretted hydrogen to be
removed from it; or in the strictly chemical manner which I introduced
originally.
The power which revivifiable peroxide of iron has of absorbing rich hydro-
carbons has been urged against its adoption for the purification of gas. It
has suggested a modification of the foregoing process, by which I obtain the
ammonia in a free state without requiring the gas to be brought into contact
with the oxide. It consists in acting on solutions of hydrosulphate of ammonia
by hydrated or revivified peroxide of iron, or any suitable preparation or mix-
ture thereof, uncombined with an acid sufficient for fixing the bulk of the
ammonia. The use of free ammonia for purifying gas by rendering its sul-
phuretted hydrogen and carbonic acid removeable by solution in a little water
is not new, having been made public by the Specification of a Patent lately
abandoned, and therefore it is not claimed as part of this Invention. By
my process the oxide becomes changed into sulphuret of iron, which by.

page_text: exposure, as prescribed in the Specification of my Patent bearing date the
Fourth day of November, One thousand eight hundred and forty-seven, is
changed by the air into an effective peroxide. The following are some of
the ways in which I put this part of my Invention into operation:-I receive
vapour of hydrosulphate of ammonia, obtained from any convenient source..
into, the upper part of a covered tank almost wholly occupied with any
revivifiable peroxide of iron, made porous by a suitable admixture of sawdust
or other material spread upon sieves covered with coarse sacking, to prevent
its being washed through them. I distribute over the surface of the oxide
material, by any means used for spreading liquids in gas purifiers, as much
water as will carry down the hydrosulphate of ammonia into the porous
material, which by absorbing the sulphuretted hydrogen changes the solution
into one of free or caustic ammonia, which I then draw off by a cock placed
near the bottom of the vessel; or I otherwise condense the vapour of the
hydrosulphate of ammonia, so as to obtain it dissolved in water, and then
either distribute the solution over the surface of the material, as above said,
or after shutting the cock at the bottom of the vessel fill it up with the
ammoniacal solution, which I run off again by opening the cock after it has
for a few minutes stood on the material. Another way of practicing this
part of the Invention is to agitate a solution of hydrosulphate of ammonia with
hydrated or revivified peroxide of iron, or any preparation or mixture of iron
capable of abstracting from the solution its sulphuretted hydrogen without
fixing the bulk of its ammonia, and to leave the mixture at rest until the solu-
tion of free ammonia can be run off, and the solid precipitate be exposed to
the air to oxidize. Whatever be the means used to bring the solution of
hydrosulphate of ammonia and the metallic reagent into chemical action, if
the latter be rich in effective iron and the former only ordinarily strong as
much of the solution may be thus treated as will fill the tank over and over
again, before the energy of the metallic reagent will be exhausted. I prefer
to oxidize the sulphuret of iron produced in this process by forcing atmo-
spheric air through vessels containing the drained but still wet porous
material, blowing the gaseous products of the operation into diluted sulphuric
acid to arrest ammonia, and either conducting the residue which is not so
fixed into the hot flues of the works, or allowing it to mix freely with the air,
as it is quite or nearly devoid of odour.
And I also apply my Invention in part to the oxidation, or as I have
caused it to be popularly called revivification, of peroxide of iron after con-
version into sulphuret of iron by contact with impure gas for its purification.
Attempts have been made with more or less success to revivify spent oxide

page_text: material in the purifying vessels, through which the gas has been, passed for its
purification, but the practice is apt to cause a dangerous elevation in tem-
perature. I avoid this evil by first filling up the gas purifiers which contain
the spent material, or otherwise drenching it with water or other aqueous
liquor, and by then forcing the current of air through it after it has become
only so free, from water as draining will make it. The oxide material to
be thus treated should be prevented from passing through the sieves of the
purifiers by coarse sacking or other suitable substance, placed upon them
before they are charged. It is not indispensibly necessary that the ammo-
niacal solutions used in this part of the Invention for producing free ammonia
should contain only hydrosulphate; they may consist partly of ammoniacal
carbonate, the ordinary gas liquor or washings answering the purpose in a
very satisfactory manner, and offering the additional advantage of being
generally ready at hand. The said liquors treated in the manner prescribed
for solutions of hydrosulphate, notwithstanding the carbonic acid they contain,
absorb with avidity both sulphuretted hydrogen and carbonic acid, like the
solutions of free or caustic ammonia; and by reason. first, of there being no
sulphur left in them to give existence to the soluble sulphuret of calcium,
and, secondly, of the insoluble nature of carbonate of lime, they admit of
very easy conversion into entire solutions of free ammonia by treatment with
lime. When gas washings are so abundantly produced as to contain but little
ammonia to make them valuable, they will by this treatment with oxide be
made so innocuous as to be admissible into the common sewers.
When ammonia or any of its soluble combinations is to be removed from
gas by any fluid mestruum in which it is soluble, I use for the purpose a
modification of my double diaphragm scrubber, which may be thus con-
structed: Take a cylinder about three inches long, and of as many feet in
diameter as may be requisite, closed at one of its ends by a disc perforated
all over with holes, about one-eighth of an inch in diameter or somewhat
larger, and about three-quarters of an inch apart, each of which may be par-
tially plugged by a small nail. Place the short cylinder with its perforated
end downward within the case of a cylindrical common scrubber, so much
larger in diameter than itself that a horizontal flanch a few inches wide,
turned outward from the top edge of the short cylinder, and fixed air-tight
to a ring of angle iron on the inner surface of the cylindrical case, shall so
divide the scrubber into two chambers that no gas shall be able to pass from
one to the other without passing through the holes in the perforated disc.
Take a second short cylinder, closed at one end by an unperforated disc, and
of a diameter intermediate between that of the former short cylinder and the

page_text: case of the scrubber which contains it, and so fix it with its disc horizontally
below the former one that if it were full of water the small perforations in
the upper disc would be immersed in the water about an inch. Fix a short
overflow pipe, about two or three inches diameter, water-tight into some part of
the unperforated disc, its upper orifice projecting upwards loosely through and
to the distance of about half an inch above the upper perforated disc, and its
lower end descending to be sealed by plunging into a cup of water supported
some inches below the unperforated disc. Sufficient space must be left
between all contiguous parts of the two short cylinders and their discs for the
gas, which is to be scrubbed in them freely, to enter and pass between them,
in order to ascend by the perforations of the upper disc. These holes must
be in sufficient number for its free passage, and the dises in which they are
made as horizontal as possible; instead of one there may be any greater
number of these double diaphragms fitted to the scrubber, in which case only
alternate overflow pipes should be perpendicular to one another, in order that
all their seal cups may be sunk or let in water-tight to the unperforated disc
next below them respectively. In vessels of large size I prefer to have the
double diaphragms as much as eighteen or twenty-four inches apart, with man-
holes in the unperforated discs, or in the case of the scrubber for entering
between them, and to make each perforated disc of moveable pieces, narrow
enough to pass in and out by the man-holes, aud confined to their places by
the superincumbent pressure of square iron bars laid upon their edges. The
action of the scrubber is as follows:-With respect to each of the double
diaphragms it may contain, the liquid to be used is made to enter between
the two discs of the diaphragms to ascend through the perforations of the
upper disc, and to overflow and fall down by the trapped wire prepared for
that purpose; meanwhile the gas presented below the double diaphragm is
constrained first to descend between the two short cylinders driving the liquid
before it, then to occupy more or less of the space between the two horizontal
discs, and finally to pass up through the perforations of the upper disc to
become distributed through the liquid lying above it.
By this arrangement any given portion of liquid may be kept at its work
so long as it continues to do it effectually, because it can only quit the double
diaphragm as fresh liquid arrives to cause it to overflow, and when several
double diaphragms work in the same scrubber the result is particularly excel-
lent, for in that case the gas comes successively into contact with fresh
portions of liquid, each portion less exhausted of energy than that which
preceded it, while the acting liquid, as it becomes more and more inert by
its downward progress, is successively brought into contact with gas, more

page_text: easily acted upon because more impure. The impure gas should be deprived
of tar by passing through dry coke before it arrives at the double diaphragms.
But to make provision against inattention in that respect, I fix one end of a
pipe curved at right angles flush into the bottom of each seal cup, the other
end of the pipe projecting through the case of the scrubber, and being stopped
outside by a plug; the withdrawal of that plug, aided by steam admitted to
the body of the scrubber, will speedily clear the seal cup and diaphragm of
any tarry matter that may at any time have accumulated, so that there will
be seldom or never occasion to enter the scrubber by the man-holes for
cleaning it.
The improved double diaphragm scrubber may be constructed in a variety of
ways and forms, the gas being sometimes made to enter between the two parts of
each diaphragm at its centre instead of at its perimeter; but whatever be the
detail adopted for putting the principle into operation (the materials of which
the apparatus is constructed being always suited to the nature of the reagents
to be used in it), it may be applied with advantage to many purposes, such as
the washing of gas with water or diluted acid, the strengthening of gas
liquor or weak ammoniacal washings otherwise obtained, or the more im-
portant purpose of combining ammonia washing and water washing in a single
operation.
When the apparatus is to be used for that twofold purpose, I prefer to
have it constructed with six or eight double diaphragms, as thereby not only
may the gas have the full advantage of the ammonia washing, but also the
ammonia may be wholly recovered for the market, increased in quantity and
strength by a considerable addition acquired from the gas. For this purpose
the diaphragms should be worked in two sets, the lower set being used with
the ammoniacal water, and the upper set with plain water, the entry of both
liquids being regulated by stop-cocks delivering to the top diaphragms of the
sets respectively, and the water entering with just speed enough to wash back
the soluble compounds of ammonia, so that they shall not even contaminate
the water on the uppermost diaphragm. This water being relatively small in
quantity mixes with the ammoniacal liquor used on the lower diaphragms,
and passes out with it in the ordinary way at the lower part of the apparatus.
Instead of being fed with a continuous stream of liquid I sometimes flush
any particular scrubber or set of diaphragms by an intermitting supply poured
occasionally and suddenly from an elevated cistern into the space between the
two parts of its upper diaphragm. There are many known contrivances for
causing the elevated cistern to discharge itself repeatedly after any desired
interval, either of which may be adopted; but I prefer the following:-On

page_text: knife edges on the side of a cistern of convenient size, standing on the top of
the scrubber, and receiving a constant supply of the washing liquid, I place a
scale beam so curved upwards at its ends that the points of support are much
below the centre of gravity. To the outer arm of the beam I suspend a bucket,
so situated that the cistern when full overflows into it by a spout arranged for
that purpose, and I connect the inner arm of the beam by a wire to a large
valve in the bottom of the cistern, commanding a pipe of corresponding size
leading through the outer case to the space within the upper double diaphragm,
either of the scrubber or of the particular set in which the liquid is to be used.
The position of the beam must be so adjusted that the rising of the valve shall
in effect considerably shorten the arm from which it is suspended, while it
lengthens the other arm, and that the rising of the bucket shall in effect con-
siderably shorten its particular arm of the beam, while it lengthens the inner
arm, the effect of which is that the movement of the beam cannot be commenced
without being promptly completed. The weights of the moveable parts must
be so adjusted that the bucket shall descend before it is quite full, and ascend
before it is quite empty; and there must be a provision for emptying it when
down, which I effect by a stop-cock in its bottom, left so far open as to let the
fluid out from it less rapidly than it enters, or by a valve which is opened on
the descent of the bucket by the resistance of a support placed beneath it.
I distil the volatile products of gas liquor or ammoniacal washings from any
suitable distillatory apparatus into a close iron vessel half filled with a cold
saturated solution of sulphate of iron. I prefer to use one of the known con-
tinuous processes of distillation, and to cause steam to pass with the other
volatile products into the metallic bath, which it cleanses of foul odours, which
I carry off by an eduction pipe fitted to the cover of the vessel, and leading
to red hot flues, in which they are effectually destroyed. I know when the
solution of sulphate of iron is decomposed by its ceasing to absorb ammonia,
and at that time 1 let out the contents of the close vessel, mix them with
several volumes of cold water, run the whole upon a filter. (such as is herein-
before described answers the purpose, with or without previous settling and
decanting), evaporate the clear liquor in any ordinary manner for the pro-
duction of sulphate of ammonia, and oxidize the solid residue mixed with saw-
dust, or other porous material, or with the materials already mentioned
with respect to the similar residue obtained by purifying gas with solution of
sulphate of iron; or instead of making at first two separate products I place
the whole decomposed solution of sulphate of iron in a flat iron basin on the
tops of retorts beds or flues in gas works, where without boiling it can become
sufficiently solid for convenient removal to other localities, in which the

page_text: operations for separating it into two products may be more conveniently
carried on.
Having thus described the nature of my Invention, and the manner of
putting it into practice, I claim,-
Distilling phosphorus from carthy compounds or mixtures containing phos-
phate of ammonia and carbonaceous matter.
The combination of means described for obtaining simultaneously from the
residue of the purification of gas by solution of sulphate of iron two products,
namely, sulphate of ammonia and hydrated peroxide of iron, in a state of
admixture with lime, magnesia, carbonate of lime, or carbonate of magnesia,
or any two or more of them.
Obiaining ammonia, and simultaneously combining it with the carbonic acid
of impure gas, by introducing hydrosulphate of ammonia into the gas prior to
or simultaneously with its entrance into dry purifiers. charged with materials
containing iron in any state, which enables it to abstract the sulphuretted
hydrogen, and to undergo atmospheric revivification alternately, with the sub-
sequent removal from the gas of its ammonia and combined carbonic acid; but
I do not claim the washing or scrubbing of impure gas with ordinary gas
liquors, as practised for the purpose of making them more rich in ammoniacal
compounds, even though the gas be afterwards passed through a material
containing hydrated or revivifiable peroxide of iron.
Converting solutions, containing in large or small quantities an ammoniacal
hydrosulphate, mixed or not with ammoniacal carbonate, into solutions either
wholly or in part of free or caustic ammonia, by the agency of such oxides or
preparations or mixtures containing chemically divided iron, as will abstract
the sulphuretted hydrogen without saturating or fixing the bulk of the
ammonia; also admitting water or watery solutions to drench what are known
in gas works as porous mixtures of hydrated or revivifiable peroxide of iron
while in the purifying vessels, preparatory to forcing through those vessels a
current of air for the revivification of the purifying material which they
contain.
The purification of gas from ammonia or ammoniacal compounds by washing
it in a scrubber divided by one or more double diaphragms, each so constructed
that its lower part is a basin to sustain the acting liquid, into which the upper
and perforated part of the double diaphragm is immersed for distributing the
liquid and the gas.
Receiving the volatile products distilled from gas liquor or ammoniacal
washings into a close vessel containing sulphate of iron in solution, together
with either the subsequent separation and evaporation of the resulting liquor
1

page_text: into sulphate of ammonia, and the mixture and peroxidation of the iron pre-
cipitate, or the evaporation by gentle heat of the mixed products of the
distillation, as herein-before described.
In witness whereof, I, the said Richard Laming, have hereunto set my
hand and seal, the Thirty-first day of July, in the year of our Lord
One thousand eight hundred and fifty-seven.
RICHARD LAMING. (L.S.)