IMPROVEMENTS IN THE EXTRACTION OF AMMONIA FROM FERMENTED AND OTHER LIQUIDS AND IN THE REGENERATION OF THE AGENTS USED IN SUCH EXTRACTION
Year: 1867

page_text: LETTERS PATENT to Alexander Melville Clark, of 58, Chancery Lane, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
EXTRACTION OF AMMONIA FROM FERMENTED AND OTHER LIQUIDS AND IN THE
REGENERATION OF THE AGENTS USED IN SUCH EXTRACTION."—A commu-
nication from abroad by Armand Coste and Louis Taupin de Rosnay,
Merchants, both of 29, Boulevart St. Martin, Paris.
Sealed the 12th June 1868, and dated the 14th December 1867.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents, with his Petition, on the
14th December 1867.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE.
MENTS IN THE EXTRACTION OF AMMONIA FROM FERMENTED AND OTHER LIQUIDS AND
IN THE REGENERATION OF THE AGENTS USED IN SUCH EXTRACTION," to be as
follows:-
This Invention consists in the preliminary precipitation of the ammonia
contained in fermented urines, sewage waters, waste waters of gasworks,
wool washing, and all ammoniacal liquids generally in the form of ammoniaco-
magnesian phosphates, and in the direct treatment of this salt by means of

page_text: lime, also in the revivification of the phosphoric acid and magnesia employed
in the precipitation of the ammonia. Ammoniaco-magnesian phosphate
possesses the property of being but slightly soluble in water, and by the direct
application of phosphoric acid and magnesia in any ammoniacal liquid such as
those above mentioned the phosphoric acid combines with tho ammonia in
the liquid and the magnesia and forms ammoniaco-magnesian phosphate, which
from its insolubility in water becomes precipitated in the form of sediment at
the bottom of the vessel. The same result may be obtained by employing tho
liquid acid phosphate of magnesia. The ammoniaco-magnesian phosphate
precipitated in the form of sediment at the bottom of the vessel is then
decanted and dried if desired; it is then treated with quicklime in retorts
ur hoilers in order to extract the ammonia, and if dry water is added to render
the mixture more complete; the residue, consisting of phosphates of lime and
magnesia mixed with foreign matters, may be usefully employed in agriculture.
This process of manufacturing ammonia by concentrating in a relatively very
small volume the whole of the ammonia contained in large quantities of water
possesses the following advantages as compared with those heretofore adopted :—
1st. A considerable economy is obtained in the fuel employed for heating
and vaporizing large quantities of water.
2ndly. The ammonia so obtained is rendered transportable, while the liquids
in which it is contained may be so-treated anywhere.
3rdly. The ammonia obtained will be deprived of the particular odour of the
liquid from which it is directly extracted.
The improved process above described requires no special apparatus, the
liquids being merely filtered in reservoirs when mixed with solid matters, the
precipitation of the ammoniaco-magnesian phosphato being effected in other
reservoirs, while the decantation of the mother waters after the precipitation
is effected in boilers or ordinary retorts, or in a Wooll's apparatus.
In order to separate the lime which has served to obtain the ammonia and
decompose the ammoniaco-magnesian phosphate and extract from the residue
the phosphoric acid and maguesia originally employed for the precipitation of
.the ammonia in the form of ammoniaco-magnesian phosphate I take hydro-
chloric acid at 22 degrees in proportion equal to five or six times the weight
of limo employed and pour it on the residue, adding tho necessity quantity of
water for ensuring its complete solution; I then stir the solution and pour in
the necessary quantity of sulphuric acid for saturating the lime employed,
allowing the insoluble sulphate of lime which forms to precipitato, which is
. afterwards carefully collected and all tho mother wators it contains expressed.
The mother waters are next distilled in a Woolf's apparatus in order to recover

page_text: the hydrochloric acid employed, and in the boiler the phosphate of magnesia
which originally served for the formation of the ammoniaco-magnesian
phosphate.
It should be observed that the hydrochlorate of ammonia thus produced is
pure and does not require refining, while by disposing side by side a distilling
apparatus for disengaging the ammonia and another for regenerating the
bydrochloric acid by their combination sublimated hydrochlorate may be
directly obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Melville Clark in the Great Seal Patent Office on
the 18th June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Alexander Melville Clark, Her special licence that I, tho
said Alexander Melville Clark, my executors, administrators, and assigns, or
such other's as I, the said Alexander Melville Clark, my executors, adminis-
trators, 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 Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN THE EXTRACTION OF AMMONIA FROM FERMENTED
AND OTHER LIQUIDS AND IN THE REGENERATION OF THE AGENTS USED IN SUCH
EXTRACTION," a. communication to me from abroad by Armand Coste and
Louis Taupin de Rosnay, Merchants; both of 29, Boulevart St. Martin,
Paris, upon the condition (amongst others) that I, the said Alexander
Melville Clark, 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.

page_text: NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement (that is to say):
This Invention consists in the preliminary precipitation of the ammonia
contained in fermented urines, sewage waters, waste waters of gasworks,
wool washing, and all aminoniacal liquids generally, by means of neutral
phosphate of magnesia in the form of ammoniaco-magnesian phosphates and
in the direct treatment of this salt by means of lime or magnesia, also in the
revivification of the phosphoric acid and magnesia employed in the precipi-
tation of the ammonia. Ammoniaco-magnesian phosphate possesses the
property of being but slightly soluble in water, and by the direct application
of phosphoric acid and magnesia in any ammoniacal liquid such as thoso
above mentioned the phosphoric acid combines with the ammonia in the
liquid and the magnesia and forms ammoniaco-magnesian phosphate, which
from its insolubility in water becomes precipitated in the form of sediment at
the bottom of the vessel. The ammoniaco-magnesian phosphate precipitated
in the form of sediment at the bottom of the vessel is decanted and dried if
desired; it is then treated with quicklime in retorts or boilers in order to
extract the ammonia, and if dry water is added to render the mixture more
complete; the residue, consisting of phosphates of lime and magnesia mixed
'with foreign matters, may be usefully employed in agriculture. This process
of manufacturing ammonia by concentrating in a relatively very small
volume the whole of the ammonia contained in large quantities of water
possesses the following advantages as compared with those heretofore
adopted:―
1st. A considerable economy is obtained in the fuel employed for heating
and vaporizing large quantities of water.
2ndly. The ammonia so obtained is readily transported, while the liquids in
which it is contained may be so treated anywhere.
3rdly. The ammonia so obtained will be deprived of the particular odour of
the liquid from which it is directly extracted.
The improved process above described requires no special apparatus, the
liquids being merely filtered in reservoirs when mixed with solid matters, the
precipitation of the ammoniaco-magnesian phosphate being effected in other
reservoirs, while the decantation of the mother waters after the precipitation
is effected in boilers or ordinary retorts, or in a Woolf's apparatus.
The following is the process I adopt for the revivification of the phosphoric
acid and magnesia employed for the precipitation of the ammonia in the form

page_text: of ammoniaco-magnesian phosphate:-In order to separate the lime which
has served to obtain the ammonia and decompose the ammoniaco-magnesian
phosphate and extract from the residue the phosphoric acid and magnesia
originally employed for the precipitation of the aminonia in the form of
ammoniaco-magnesian phosphate I take hydrochloric acid at 22 degrees in
proportion equal to five or six times the weight of the lime employed, and
pour it on the residue, adding the necessary quantity of water for ensuring its
complete solution; I then stir the solution and pour in the necessary quantity
of sulphuric acid for saturating the lime employed, allowing the insoluble
phosphate of lime which forms to precipitate, which is afterwards carefully
collected, and all the mother waters are next distilled in a Woolf's appa-
ratus in order to recover the hydrochloric acid employed, and in the boiler
the phosphate of magnesia which originally served for the formation of
ammoniaco-magnesian phosphate.
I will now proceed to describe, as forming part of the Invention, the process
of manufacturing ammonia by the aid of calcined magnesia and bydrochloric
acid. This process is base like the one first described, and of which it forms
a part, on the almost perfect insolubility of ammoniaco-magnesium phosphate
in water. By placing in an ammoniacal liquid the water to be purified (of
gasworks, for example) containing in solution carbonates and hydrosulphates
of ammonia, phosphoric acid, and magnesia, these two bodies will combine
with the ammonia of the ammoniacal salts it contains, the carbonic acid
and hydrosulphuric acid disengage, and ammoniaco-magnesian phosphate is
formed, which in consequence of its insolubility is precipitated at the bottom
of the vessel.
If the phosphoric acid and magnesia are in suitable proportions (one
chemical equivalent or anhydrous phosphoric acid Pho³ for two equivalents
of magnesia MgO) the whole of the ammonia will be precipitated and leave
no trace in the liquid, while the ammoniaco-magnesian phosphate may
be obtained by decantation; it may then be expressed if desired, dried either
in the open air or in a stove, ground to a fine powder, and placed in barrels
or bags like cement or plaster for use in manufactories of ammonia. The
above described reactions may be expressed by the following chemical
equation:-

page_text: proportions in order to form ammoniaco-magnesian phosphate. An excess of
phosphoric acid would give rise to a production of simple phosphate of ammonin,
which being a very soluble salt would remain in solution in the liquid and
become lost. Ammoniaco-magnesian phosphate may be produced directly in
gasworks and manufactories of coke, animal black, and others by passing the
gases through purifiers filled with phosphoric acid diluted in water containing
chloride of magnesium in solution. The rise in temperature produced by
the passage of the gases drives out the hydrochloric acid produced by the
decomposition of the salt, while the acid may also be extracted if desired. The
ammoniaco-magnesian phosphate being extracted the ammonia is then with-
drawn, after which the phosphoric acid and magnesia employed are rege-
nerated and form neutral or basic phosphate of magnesia and hydrochloric
acid, which process forms part of the present Invention, as follows:-Both
processes either with lime or magnesia give almost analogous results, the
choice being determined by the cost of the re-agents employed in the reaction
and the use to which the sulphate of lime obtained in the second case may bo
put. When employing magnesia calcined magnesia is added to the ammo-
niaco-magnesian phosphate and mixed with great care, after which the mixture
is placed in a distillatory apparatus, provided if possible with a mechanically
acting mixer for keeping the mixture in motion during the distillation; I
then add water as pure as possible, or prefer to introduce steam into the
apparatus obtained from a boiler close at hand for the purpose of beating the
In this manner the ammonia of the ammoniaco-magnesian phosphate
will be displaced by the magnesia and form tribasic phosphate of magnesia
(MgO) Pho, the ammonia after distillation being collected in a Woolf's
apparatus, or preferably in a concentrating apparatus similar to those in use
for alcohols, except it is desired to pass them into receivers containing acids
in order to obtain ammoniacal salts. The quantity of magnesia chemically
necessary for displacing the ammonia is from one equivalent of magnesia for
one equivalent of ammoniaco-magnesian phosphate, or 20 parts of MgO to
246 parts of (Az³HO (MgO) Pho 12HO). It is necessary in practice
to add an excess of magnesia at least double that given above, that is,
to use two equivalents of magnesia in order to cause the ammonia to disen-
gage more rapidly and more effectually. The reaction, supposing an excess
of one equivalent of magnesia be employed, is expressed by the following
equation:-Az³ (MgO) Pho' + 2MgO + Aq = (MgO)³ Pho³ + Mg0+
Azl+Aq. The residue remaining in the distillatory apparatus after the
ammonia has ceased to disengage contains the magnesin employed for sepa-
rating the ammonia, one-half in a fresh state MgO and the remainder, in
same.

page_text: the form of tribasic phosphate of maguesia (MgO)³ PhO. The phosphoric
acid and magnesin employed for precipitating the ammonia in the form of
ammoniaco-magnesian phosphate combines with the portion of magnesia
which has served for obtaining the ammonia; and forins with it tribasic phos-
phate of magnesia in the proportion of one equivalent of pure magnesia and
one equivalent of tribasic phosphate of magnesia mixed together. In this
condition the residue would not serve again for the precipitation of the
ammonia, and it is necessary Loth to separate the pure magnesia and withdraw
from the tribasic phosphate one equivalent of its base in order to reduce it to
the condition of neutral or bibasic phosphate. I take two equivalents of
hydrochloric acid CH diluted in a sufficient quantity of water, and place
them in a receptacle with the residue, where they are allowed to rest for several
hours and then frequently stirred, tho mother waters being obtained by
decantation. The deposit is then washed in order to separate any mother
waters it may contain and dried. The half of the hydrochloric acid equal to
one equivalent combines with the free magnesia MgO of the mixture, and
forms water and chloride of magnesium which remains in solution in the
mother waters. The other half of the acid (equal to one equivalent) com-
bines with one of the three equivalents of the base of basic phosphate, and
a's forms water and chloride of magnesium. In this manner I obtain on
the one hand from the precipitate phosphoric acid in the form of neutral
phosphate and the magnesia employed for fixing the ammonia, which may
serve again after being dried, and on the other band I obtain by evaporation
in the form of chloride of magnesium the magnesia employed for expelling
the ammonia from the double phosphate and hydrochloric acid. The reaction
is indicated by the following equation:-(MgO)³ Pho³+MgO+HCI+Aq=
(MgO) PLO +2MgCl+2HO+Aq. For every 224 pounds of ammo-
niaco-megnesian phosphate AzHI HO (MgO) Pho³ 12H10) furnished by
100 pounds (about) of neutral phosphate MgO HO Pho³, and from 120
to 130 gallons of water from gasworks, I employ about 40 pounds of puro
calcined magnesia (or it may be a little more, taking into consideration
the extraneous matters usually contained) and about 200 pounds of bydro:
chloric acid at 22 degrees diluted to 7 or 8 degrees, from which is extracted
about 80 pounds of white volatile alkali at 70 degrees Fahrenheit, 100 pounds
of neutral phosphate of magnesia, and 90 pounds of choride of magnesia of
anhydrous nature, without taking into account the inevitable waste, which
Lowever except in the case of the chloride of magnesium is but slight.
'
When employing lime for the extraction I simply substitute it for the
magnesia equivalent for equivalent and use the same apparatus. The ammonia

page_text: and the ammoniaco-magnesian phosphate is displacod by the lime, and distilled
while tribasic phosphates of lime and magnesia form in the apparatus, which
after the operation is terminated will be found mixed with the lime in excess.
The reaction is expressed by the following equation:-3 {AzE (MgO),
Pho+6CaO+Aq=(CaO) Pho+2 { (MgO) Pho³}+sCaO+3Azl
+Aq. The residue thus contains the lime employed for extracting the
ammonia obtained in the first operation, and also the phosphoric acid and
magnesia employed for the precipitation of the ammonia in the double
insoluble salt. These two agents, the phosphoric acid and the magnesia, are
separated in order to be again used in a similar manner, for which purpose I
place the residue in a vat consisting of one equivalent of tribasic phosphate of
lime, three equivalents of tribasic phosphate of lime in excess, two equivalents
of tribasic phosphate of magnesia, with nine equivalents of hydrochloric acid
HCI, diluted in sufficient water to permit of the whole being dissolved,
which is quickly effected by stirring the mixture with a wood spatula. The
liquor obtained becomes very limpid if the ammoniaco-magnesian phosphate
and the limo first employed are fice from impurities. One part of the lime
(two equivalents) and the excess added of three equivalents (in all five
equivalents) are decomposed and produce five equivalents of chloride of calcium
in a very soluble condition which dissolves. The remainder of the lime (one
equivalent) remains in combination with the phosphoric neid (one equivalent)
and forms acid phosphate of lime in a very soluble condition which dissolves.
One portion of magnesia (four equivalents) produces an equal number of
equivalents of chloride of magnesium in a soluble condition which dissolves,
and lastly the remainder of the magnesia (two equivalents) remains combined
with the rest of the phosphoric acid (two equivalents), forming two equivalents
of acid phosphate of magnesia in a soluble state which also dissolves. This
complex reaction is expressed by the following equation:-(CaO)³ Pho³+
s CaO+ ((MgO)³ Pho³} +9 Hel+Aq=5Ca Cl+4 Mg Cl+CaO Pы0'+
2MgO PEO'+Aq.
In the treatment of waters of gasworks the residue of the distillation of
ammonia always contains impurities and metallic salts which give the liquor a
more or less deep green tinge. In order to obtain the lime, the weight of
which is known, I pour into the liquor the necessary quantity of sulphuric
acid in a boiling state required for saturating it, and transform it into sulphate
of lime the proportions being six equivalents of acid SO HO to six equivalents
of lime. The acid need not be highly concentrated. I allow the liquor
containing the sulphuric acid to remain for twenty-four hours, stirring
frequently. I then collect the precipitate, wash it slightly, and place it in a

page_text: press in order to extract all the mother waters which are carefully preserved.
This precipitate consists of sulphate of line produced by the decomposition of
cbloride of calcium and acid phosphate of lime produced by the sulphuric acid.
The reaction is expressed by the following equation:-5 Ca Cl+4Mg Cl+
CuO Pho+2 MgO Pho³+6 SO+Aq=6 CaO SO3+3 Mg Cl+3 MgO
Pho³+6 HCI+Aq. The mother waters contuin on the one hand the hydro-
chloric acid employed for the dissolution of the residue of the distillation
of the ammonia partly combined with a portion of the magnesia, and on the
other hand they contain the phosphoric acid combined with the remaining
magnesia in the form of acid phosphate of magnesia. The phosphoric acid
is fixed while the hydrochloric acid is volatile and less active, and may thus
be separated by distillation. I place the mother waters in a distilling
apparatus and heat them, when the whole of the hydrochloric acid will be
distilled in consequence of the decomposition of the chloride of magnesium
and may be collected in a Woolf's apparatus or column to serve again; while
the acid phosphate of magnesia, in consequence of the expulsion of the
bydrochloric acid, fixes the magnesia of the chloride of magnesium and becomes
transformed into neutral phosphate which remains in the boiler. The re-
action is expressed as follows:-3 Mg Cl+3 MgO Pho³+6 HCI+Aq=
3 (MgO) Pho³+9 HCI+Aq. The phosphoric acid and magnesia employed
for fixing the ammonia and for forming ammoniaco-magnesian phosphate
are thus regenerated and may serve for the precipitation of a fresh quantity of
ammonia. For every 224 pounds of ammoniaco-magnesian phosphate Az³
HO (MgO) Phos (12 HO) furnished by one hundred pounds (about) of neutral
phosphate (MgO) HO PLO³, and from 120 to 130 gallons of water from gas-
works, I employ about 54 pounds of pure quicklime CaO, 300 pounds of
hydrochloric acid at 22 degrees, 95 pounds of sulphuric acid at 66 degrees (or
an equivalent quantity of acid at 50 degrees, about 170 pounds). From this
is extracted about 75 pounds of volatile white alkali at 70 degrees Fahrenheit,
100 pounds of neutral phosphate of magnesia, 160 pounds of sulphate of lime,
and 300 pounds of hydrochloric acid at 22 degrees, without reckoning the
waste which falls principally on the hydrochloric acid. The sulphate of lime
obtained on extracting the ammonia from the waters used in the purification
of gas has a greenish blue color of the nature of Prussian blue which might
be extracted. Whether one or other of the two processes above described be
employed one cubic yard of the water used for purifying gas requires about
190 pounds of neutral phosphate of magnesia (MgO) HO Pho³ for its
treatment, and furnishes on giving up its ammonia about 280 pounds of
ammoniaco-magnesian phosphate AzH³ HO (MgO)' PhO 12 IIO), which on

page_text: being treated by one of the foregoing processes produres about 180 pounds of
volatile alkali at 22 degrees.
Ammoniacal Salts.-The ammoniacal gas obtained by the two process's
before described is pure, and the volatile alkali white and not amber colored,
while the ammoniacal salts are obtained in a perfectly refined condition without
requiring to be further treated. The foregoing processes may be applied with
equal advantage both on a large and small scale; thus they may serve for
obtaining ammonia from all kinds of manufactories and especially from gas-
works. The gases escaping from coke ovens contain much ammonia which
is easily obtainable, and the same is tho case with the gases produced by the
combustion of bones in animal black manufactorios. The volatile alkali and
ammoniacal salts, instead of being manufactured specially or in the gasworks,
may by the aid of the processos herein described be produced economically
and of superior quality in the large manufactories of such chemical products
as sulphuric acid, hydrochloric acid, or soda, who would supply the phosphates
of magnesia they produce to gasworks, coke ovens, and others. These
latter would in this case only require to precipitate the ammonia from their
ammoniacal waters and desiccate the ammoniaco-magnesian phosphate and
supply them to the chemical manufactories, where after extracting tho
ammonia the neutral posphate of magnesin is regenerated.
Manufacture of Neutral Phosphate of Magnesin.-The neutral or bibasic
phosphate of magnesia (MgO) HO PO' does not fix the ammonia in a free
and pure condition but in a nascent state; thus it decomposes with sufficient
rapidity the ammoniacal salts carbonate and hydrosulphate of ammonia by
expelling the volatile acid, and combining equivalent for equivalent with the
ammonia thus separated in order to form ammoniaco-magnesian phosphate.
This reaction is expressed by the following equation:-Az HHS+(MgO)=
110 Pho+Aq=AzH³ HO (MgO) Pho+HS+Aq. On experimenting
with the water of gasworks, for example, it will be found that the ammoniaco-
magnesian phosphate precipitated will after its.combination have a volume
nearly double that of the neutral phosphate of magnesia; this property of the
neutral phosphato of magnesia may be usefully applied for extracting ammonia
in the form of ammoniaco-maguesiau phosphate from any liquid in which it
may be contained in the from of volatile salts in solution, such as the water
used for purifying gas, sewage waters, water used in wool washing, and others,
in order to extract tho volatile alkali by the processes herein-before described,
or for making manure for agricultural purposes.
The neutral phosphate of magnesia may be made in several ways, the
following process giving excellent,results:-Manufacturers of glue and gelatine

page_text: employ considerable quantities of bones in their manufacture, from which they
extract "osseine" by treating them with hydrochloric acid diluted in water
after having previously extracted the grease or fat from the bones. The
bones so treated contain about 30 per cent. of "osséine," 50 per cent. of
tribasic phosphate of lime (CaO³ Ph05), and 15 per cent. of carbonate of lime:
After being steeped for some days in dilute hydrochloric acid the "osseine"
becomes separated, and the acidulated mother waters contain in solution in
the form of chloride of calcium and acid phosphate of lime all the basic
phosphate of lime and carbonate of lime associated with the "ossćine " in the
bones. The acidulated waters produced by the treatment of 224 pounds of
bleached bones and the production of about 70 pounds of "osséine" thus
contain 112 pounds of basic phosphate of lime transformed in the manner
above described, or about 50 pounds of semi-anhydrous phosphoric acid Pho³.
Many manufacturers of glue at present either get rid of or but imperfectly
utilize these mother waters, although they may be usefully employed in the pre-
cipitation of phosphates of magnesia by proceeding in the following manner :-
I will first observe that in some glue manufactories lime is added to the
acidulated waters, which in combining with the acid phosphate of lime in
solution forms basic phosphate, and this being insoluble is precipitated and col-
lected for agricultural purposes. This phosphate possesses the advantage of being
produced in a finely subdivided condition; but it is nevertheless objectionable
to transform the soluble assimilable phosphate into an insoluble phosphate.
I saturate the lime which the mother waters contain in solution in the form of
chloride of calcium and acid phosphate of lime with boiling sulphuric acid
and allow it to rest, stirring from time to time, the whole of the lime being
precipitated in the form of sulphate of lime. I then separate the precipitate,
wash and express it in order to obtain the whole of the mother, waters which
now only contain the phosphoric acid of the bones and the hydrochloric acid
employed for obtaining the "osseine." I then add chloride of magnesium to
the mother waters, which substance may be obtained at a very low price, in
the proportion of two equivalents to one of phosphoric acid; the chloride theņ
decomposes and forms acid phosphate of magnesia, which by the expulsion of
the hydrochloric acid fixes one more equivalent of magnesia, and is trans-
formed into neutral phosphate of magnesia. I may add instead of magnesia
two equivalents of calcined magnesia, it being simply a question of expense;
I may also employ sulphate of magnesia instead of sulphuric acid, and
magnesia or chloride of magnesium. The excess of magnesia thus introduced
is afterwards extracted. by the aid of hydrochloric acid., The neutral phos;
phate of magnesia and the hydrochloric acid are both obtained by.distillation

page_text: in a Woolf's apparatus or concentrating column. It should be observed that
if chloride of magnesium is employed the regeneration of the hydrochloric acid
used for obtaining the "osseine" will be effected, and a fresh quantity of this
acid be produced by decomposing the chloride of magnesium with phosphoric
acid. For treating 224 pounds of bones already bleached there is required
224 pounds of bydrochloric acid at 22 degrees Beaumé, 140 lbs. of sulphuric
acid at 66 degrees (or 220 pounds of this acid at 50 degrees), 70 pounds of
chloride of magnesium pure, or 160 pounds of raw chloride of saltworks,
which contains 43 per cent. of pure chloride. I obtain as a result, 1st, 70
pounds of "osseine," worth about 48 shillings per 224 pounds; 2ndly, from
250 to 270 pounds of sulphate of lime in a very pure subdivided condition;
3rdly, 85 pounds of neutral phosphate of magnesia ((MgO) HO Pho³);
and, 4thly, about 360 pounds of hydrochloric acid at 22 degrees. The
"osseino" will find ready employment in glue and gelatine manufactories.
The sulphate of limo obtained by precipitation is useful in paper making and
for agricultural purposes. The hydrochloric acid which it is unnecessary to
highly concentrate will serve again for treating a fresh quantity of bones. The
neutral phosphate of magnesia may be employed either in the manufacturo of
manure or of ammonia by the processes herein-before described. Supposing
it to be sold at £1 per 224 pounds the manufacturer would realize a good
profit, and at this price the semi-anhydrous phosphoric acid would be supplied
at the extremely low price of 2d. per pound. 224 pounds of this neutral
phosphate dry (MgO) HO PLO³ will fix about 50 pounds of ammonia
(AzH HO) and 200 pounds of water by becoming transformed into ammo-
niaco-magnesian phosphate (AzHI HO (MgO) Pho³ 12110) to the amount of
475 pounds about. The 50 pounds of ammonia Az³ HO are furnished by about
250 gallons of ammoniacal water of gasworks, and putting the average price
of this water at 21d. per 22 gallous they would cost 28. 5d. The cost of 475
pounds of ammoniaco-magnesian phosphate would thus be about 24 shillings
(not including the cost of drying), and this salt might be supplied to agri-
culturists at a cost of from 16 to 20 shillings por 224 pounds, supposing it is
not desired to extract the ammonia.
This mode of manufacturing neutral phosphate of magnesia may be adopted,
1st, by manufacturers of glue, who in this caso could obtain the salt as also
sulphate of lime as a sub-product of their manufacture and regenerate
indefinitely the hydrochloric acid employed in the preparation of the "osséine;"
2ndly, it may be still more advantageously employed in large manufactories of
chemical products, who might add that of making "osséine," phosphate of
magnesia, ammoniaco-maguesian phosphate, and ammoniacal salts.

page_text: If the use of neutral phosphate of magnesia were to become general the
acidulated water resulting from the preparation of the "osséine" would be
insufficient, and in this case the neutral phosphates of lime finely pulverized
would be treated with hydrochloric acid.
Acid Phosphate of Magnesia.-This phosphate in certain cases presents
some particular advantages in the manufacture of manure. The manufacture
is effected in the same manner as for the neutral phosphate except that there
is added to the acidulated waters containing phosphoric acid and hydrochloric
acid one equivalent of chloride of magnesium or of calcined magnesia instead
of two.
Having described the nature of this Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,-
1st. The processes herein-before described of extracting ammonia from the
liquids in which they are contained in the form of volatile ammoniacal salts
(such as from the water used in purifying lighting gas or putrified urines) by
previously decomposing said salts by the aid of neutral phosphate of magnesia
and precipitating it in the form of insoluble ammoniaco-magnesian phosphate,
which latter salt is afterwards treated with lime or magnesia.
2ndly. I claim revivifying the neutral phosphate of magnesia as also the
magnesia employed in the extraction of the ammonia, all in the manner
berein-before described.
3rdly. I claim the processes of manufacturing neutral phosphate of
magnesia, as herein-before described.
In witness whereof; I, the said Alexander Melville Clark, have here-
unto set my hand and seal, this Thirteenth day of June, in the
year of our Lord One thousand eight hundred and sixty-eight.