IMPROVEMENTS IN THE MANUFACTURE OF TARTARIC AND CITRIC ACIDS, AND TARTRATE OF POTASH AND SODA."
Year: 1856

page_text: LETTERS PATENT to Edmund Alfred Pontifex, of the firm of Pontifex
and Wood, of Shoe Lane, in the City of London, Chemical Manufac-
turers, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
TARTARIC AND CITRIC ACIDS, AND TARTRATE OF POTASH AND SODA."
PROVISIONAL SPECIFICATION left by the said Edmund Alfred Pontifex
at the Office of the Commissioners of Patents, with his Petition, on the
12th March 1856.
I, EDMUND ALFRED PONTIFEX, of the firm of Pontifex and Wood, of Shoe
Lane, in the City of London, Chemical Manufacturers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF TAR-
TARIC AND CITRIC ACIDS, AND TARTRATE OF POTASH AND SODA," to be as follows:-
I first separate or filter the liquors, from which tartaric and citric acids and
tartrate of potash and soda are formed, from the sulphate of lime and other
impurities, by pressure through textile fabrics, or by other suitable means, and
then I evaporate in vacuo. After the crystals have been formed, I again melt and
evaporate in vacuo, if required, until the crystals are sufficiently pure. The
apparatus which I employ to carry my Invention into effect is as follows:--A
lead or other vessel in which the liquors are to be evaporated or melted is
placed within another vessel, which is exhausted, whereby the pressure of the

page_text: atmosphere is relieved both from the inside and outside of the contained vessel,
and thus the most convenient material (lead) may be used to contain the
liquors; or the lead may be dressed down upon the outer vessel with some
pigment or cement between the surfaces so as to expel the air, and the joints
so arranged that no air can enter between them; or glass, earthenware, or
enamelled iron or other material, not affected by acids, may be used as the
evaporating vessel, without the addition of another vessel to sustain the pressure.
I employ peculiarly constructed overflow receivers and external condensers.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edmund Alfred Pontifex in the Great Seal Patent Office on
the 12th September 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
ALFRED PONTIFEX, of the firm of Pontifex and Wood,, of Shoe Lane, in the.
City of London, Chemical Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of March, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edmund Alfred Pontefex, Her special licence that I, the said Edmund
Alfred Pontifex, my executors, administrators, and assigns, or such others
as I, the said Edmund Alfred Pontifex, 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 Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF TARTARIC AND CITRIC ACIDS, AND TARTRATE
OF POTASH AND SODA," upon the condition (amongst others) that I, the said
Edmund Alfred Pontifex, 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 Edmund Alfred Pontifex, 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

page_text: following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say :-
My Invention consists in the following process of and apparatus for
manufacturing tartaric and citric acids, and tartrate of potash and soda :-
I first separate or filter the liquors from which tartaric and citric acids and
tartrate of potash and soda are obtained from so much of the sulphate of lime
or baryta, &c. as is not in solution, and from other impurities, by pressure
through textile fabrics, or by other suitable means, and then I evaporate in
vacuo nearly to concentration, and then if necessary let the concentrated
liquors deposit any sulphate of lime or baryta, or other matters that may have
previously been held in solution, by the weak acid liquor, and afterwards I
complete the concentration to the point of crystallization. After the crystals
have been formed, I again melt, and after having decolorized the liquor in the
usual way, evaporate in vacuo and crystallize, repeating the operation, if
required, until the crystals are sufficiently pure. The melting in the various
re-crystallizations I also prefer to conduct in the vacuum pan. The apparatus
which I employ to carry my Invention into effect is as follows:-A lead or
other vessel in which the liquors are to be evaporated or melted is placed
within another vessel which is exhausted, whereby the pressure of the atmo-
sphere is relieved both from the inside and outside of the contained vessel, and
thus the most convenient material (lead) may be used to contain the liquors ;
or the lead may be dressed down upon the outer vessel with some pigment or
cement between the surfaces so as to expel the air, and the joints so arranged
that no air can enter between them; or glass, earthenware, or enamelled iron
or other material not affected by acids may be used as the evaporating vessel
without the addition of another vessel to sustain the pressure. I employ
peculiarly constructed overflow receivers and external condensers. The over-
flow vessel contains at the bottom a quantity of chalk, milk of lime, or other
alkaline or carbonated solution, through which the vapour from the vacuum
pan is conducted by means of a pipe terminating in a rose. Above the surface
of. the milk of lime, or other alkaline or carbonated solution, a priming plate,
perforated for the escape of the steam, is fixed in the overflow vessel, to prevent
the solution being carried away by the rush of steam through it. The over-
flow vessel is furnished with suitable cocks and pipes for the supply of fresh or
discharge of the spent solution. The object of employing the solution here is
to collect the acetic, butyric, sulphurous and other acids, that would otherwise
pass over and injure the apparatus. The overflow vessel would also collect
The
any tartaric acid that accidentally might boil over from the vacuum pan.
steam may be condensed by the ordinary injection condenser, but I prefer to

page_text: üsė "Edmund Pontifex's patent condenser," not only on account of its economy
in air pump power and quantity of condensing water required, but because by
means of it the whole of the products of evaporation can the more conveniently
be collected, and the escape or loss of tartaric acid be detected.
In order to prevent leakage in the valves and cocks attached to the vacuum
pan; caused by the action of the acid on the metal of which such valves and
cocks are composed, I use a description of valve or cock the body of which I
make of cast-iron or other suitable metal and line it with lead. I make the
valve face and disc gland of india-rubber, and secure the spindle from the
action of the acid by a covering of lead.
In the Drawing hereunto annexed I have represented a sectional elevation
of an apparatus constructed as herein-before described. A is the vacuum
pan, which is formed of a cast-iron case B and a lining of lead C; D, is
a man-hole; E, a leaden worm for the steam; G, a valve for the admission of
steam to the worm E; and H, a valve for discharging the contents of the
vacuum. pan. This valve H is composed of a spindle L, carrying the leaden
piece K, which is covered with india-rubber I. J is an india-rubber disc or
diaphragm M, a nut and washer; and N, a screw spindle, which is fitted
with a handle, by which the valve is worked; O is a pipe leading from the
valve H; P, P, are pipes for exhausting the space between the cast-iron
case B and the lead lining C; Q, Q, is the passage to the overflow receiver,
which contains the chalk or milk of lime or other carbonated or alkaline
solution at the bottom, through which the vapour from the vacuum pan is
conducted by the pipe Q, which terminates in the rose R; R' is a supply
cock and pipe; R2 and R³ are draw-off cocks; S is the perforated priming
plate; and S¹ and Ss are glass gauges. T, the upper portion of the overflow
vessel, which may be called a safety vessel, and is connected by a passage U,
with a second safety vessel V; W is a valve for cutting off communication
between the pan, &c. and the condenser; and X is a pipe which leads to the
condenser and air pump. Although I have only described the valve or
cock Has fitted to the vacuum pan for emptying the contents thereof, I find
it applicable in a modified form to the entire apparatus where valves or
cocks are employed, and where the acid comes in contact with them. As
herein-before described, I sometimes form my vacuum pan of metal or
other suitable material, glazed, enamelled, or coated on the interior thereof
with some material or composition not liable to be acted upon by the materials
I employ. In such case I dispense with the inner vessel or lining of lead.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim,-

page_text: First, the evaporating, in vacuo, of the liquors from which tartaric and citric
acids and tartrate of potash and soda are obtained, in pans or vessels con-
structed, fitted, and operating in the manner herein-before described.
Second, the general arrangement and combination of apparatus, herein-
before described, for the manufacture of tartaric and citric acids and tartrate
of potash and soda, consisting of a vacuum pan and fittings, a safety or over-
flow vessel, with priming plate or overflow vessels, condenser, and air pump.
Third, the constructing of vacuum pans, for the purposes of my Invention,
with a lining or inner vessel of lead, and the exhausting of the air from between
the vessel and the lining; also the employment, for the purposes of my
Invention, of vacuum pans (and of safety or overflow vessels) enamelled or
glazed on the inner surfaces thereof.
And, fourth, the constructing of valves or cocks, to be employed in the
manufacture of tartaric and citric acids, in the manner herein-before described,
and represented in the Drawings annexed.
In witness whereof, I, the said Edmund Alfred Pontifex, have hereunto
set my hand and seal, this Eleventh day of September, One thousand
eight hundred and fifty-six.
EDMUND A. PONTIFEX. (L.S.)

page_text: 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 Edmund Alfred Pontifex, 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 thereof, reference being had to the Drawings hereunto
annexed, that is to say:-
My Invention consists in the following process of and apparatus for manu-
facturing tartaric and citric acids and tartrate of potash and soda.
I first separate or filter the liquors from which tartaric and citric acids and
tartrate of potash and soda are obtained from so much of the sulphate of
limė or baryta, &c., as is not in solution and from other impurites by pressure
through textile fabrics or by other suitable means, and then I evaporate in
vacuo nearly to concentration, and then, if necessary, let the concentrated
liquors deposit any sulphate of lime or baryta, or other matters that may
have previously been held in solution by the weak acid liquor, and afterwards
I complete the concentration to the point of crystallization. After the crystals
have been formed, I again melt, and after having decolorized the liquor in the
usual way, evaporate in vacuo and crystallize, repeating the operation, if
required, until the crystals are sufficiently pure. The melting in the various
re-crystallizations I also prefer to conduct in the vacuum pan.
The apparatus which I employ to carry my Invention into effect is as
follows: A lead or other vessel in which the liquors are to be evaporated or
melted is placed within another vessel, which is exhausted, whereby the
pressure of the atmosphere is relieved both from the inside and outside of the
contained vessel, and thus the most convenient material (lead) may be used to.
contain the liquors; or, the lead may be dressed down upon the outer vessel
with some pigment or cemerit:between the surfaces, so as to expel the air, and
the joints so arranged that no air can enter between them; [or glass;
earthenware, or enamelled iron, or other material not affected by acids may-be-used
as the evaporating-vessel-without the addition of another vessel to sustain the
pressure.] I employ peculiarly constructed overflow receivers and external
condensers. The overflow. vessel contains at the bottom a quantity of chalk,
milk of lime, or other alkaline or carbonated solution, through which the
vapor from the vacuum pan is conducted by means of a pipe terminating in
a rose. Above the surface of the milk of lime. or other alkaline or carbonated
solution a priming plate perforated for the escape of the steam is fixed in the

page_text: overflow vessel, to prevent the solution being carried away by the rush of
steam through it. The overflow vessel is furnished with suitable cocks and
pipes for the supply of fresh, or discharge of the spent, solution. The object
of employing the solution here is to collect the acetic, butyric, sulphurous,
and other acids that would otherwise pass over and injure the apparatus; the
overflow vessel would also collect any tartaric acid that accidentally might
boil over from the vacuum pan. The steam may be condensed by the ordinary
injection condenser, but I prefer to use "Edmund Pontifex's 'patent condenser,"
not only on account of its economy in air-pump power and quantity of con-
densing water required, but because by means of it the whole of the products
of evaporation can the more conveniently be collected and the escape or loss
of tartaric acid be detected.
In order to prevent leakage in the valves and cocks attached to the vacuum
pan caused by the action of the acid on the metal of which such valves and
cocks are composed, I use a description of valve or cock the body of which I
make of cast iron or other suitable metal, and line it with lead. I make the
valve face and disc gland of india-rubber, and secure the spindle from the
action of the acid by a covering of lead.
In the Drawing hereunto annexed I have represented a sectional elevation
of an apparatus constructed as herein-before described. A is the vacuum pan,
which is formed of a cast-iron case B, and a lining of lead C; D is a man-
hole; E, a leaden worm for the steam; G, a valve for the admission of steam
to the worm E; and H, a valve for discharging the contents of the vacuum
pan. This valve H is composed of a spindle L, carrying the leaden piece K,
which is covered with india-rubber I, J is an india-rubber disc or diaphragm;
M, a nut and washer; and N, a screw spindle, which is fitted with a handle,
by which the valve is worked; O is a pipe leading from the valve H; P, P,
are pipes for exhausting the space between the cast-iron case B and the lead
lining C; Q, Q, is the passage to the overflow receiver, which contains the
chalk or milk of lime, or other carbonated or alkaline solution at the bottom,
through which the vapour from the vacuum pan is conducted by the pipe Q,
which terminates in the rose R; R' is a supply cock and pipe; R2 and R³ are
draw-off cocks; S is the perforated priming plate; and S1 and S2 are glass
gauges; T, the upper portion of the overflow vessel, which may be called a safety
vessel, and is connected by a passage U with a second safety vessel V ; W is a
valve for cutting off communication between the pan, &c., and the condenser;
and X is a pipe which leads to the condenser and air pump.
Although I have only described the valve or cock H as fitted to the vacuum
pan for emptying the contents thereof, I find it applicable in a modified form

page_text: to the entire apparatus where valves or cocks are employed, and where the
àcid comes in contact with them.
[s-herein-before-described, I-sometimes form my vacuum-pan of metal or other
suitable-material, glazed, enamelled; or coated on the interior thereof with some
material-or-composition not liable to-be-acted upon-by-the-materials-I-employ.In
such-ease--dispense-with-the-inner vessel or lining of lead.]
And having now described the nature of the said Invention; and in what
inanner the same is to be performed, I declare that I claiin,
First, the evaporating in vacuo of the liquors from which tartaric and citric
acids and tartrate of potash and soda are obtained in páns or vessels constructel;
fitted, and operating in the manner herein-before described.
Second, the general arrangement and combination of apparatus herein-
before described for the manufacture of tartaric and-citric acids, and tartrate
of potash and soda, consisting of a vacuum pan and fittings, a safety or
overflow vessel, with priming plate or overflow vessels, condenser and air
pump.
Third, the constructing of vacuum pans for the purposes of my Invention;
with a lining or inner vessel of lead, and the exhausting of the air from
between the vessel and the lining; also the employment for the purposes of iny
Invention of vacuum pans (and of safety-or-overflow-vessels)-enamelled-or-glazed
on-the-inner-surfaces thereof.
And, fourth, the constructing of valves or cocks to be employed in the
manufacture of tartaric and citric acids, in the manner herein-before-described
and represented in the Drawings annexed.
In witness whereof, I, the said Edmund Alfred Pontifex; have hereunto
set my hand and seal, this Thirty-first day of May, One thousand eight
hundred and fifty-nine:
EDMUND A. PONTIFEX. (L.S.)