IMPROVEMENTS IN THE MANU- PACTURE OF CARBONATE OF SODA
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HARRISON
GREY DYAR, late of Cavendish Square, but now of No. 286, Regent Street,
Gentleman, and JOHN HEMMING, of Edward Street, Cavendish Square,
Gentleman, both in the County of Middlesex, send greeting.
WHEREAS we did by our petition represent unto Her most Excellent
Majesty Queen Victoria, that we had invented "IMPROVEMENTS IN THE MANU-
PACTURE OF CARBONATE OF SODA," that we were the first and true Inventors
thereof, and that the same had never been practised by any other person or
persons whatsoever to our knowledge or belief, and did thereby pray that Her
said Majesty would be graciously pleased to grant unto us, our exors, admors,
and assigns, Her Royal Letters Patent under the Great Seal of Great Britain,
for the sole use, benefit, and advantage of our said Invention within England,
Wales, and the Town of Berwick-upon-Tweed, for the term of fourteen years,
pursuant to the Statute in that case made and provided; and Her said most
Excellent Majesty Queen Victoria being willing to give encouragement to all
arts and inventions - which might be for the public good, was graciously
pleased to condescend to our request, and by Her Letters Patent under the
Great Seal of Great Britain, bearing date at Westminster, the Thirtieth day
of June, in the second year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto us, the. said Harrison Grey Dyar and John Hemming,
our exors, amors, and assigns, Her especial licence, full power, sole privilege
and authority, that we, the said Harrison Grey Dyar and John Hemming, our

page_text: exors, adññors, and assigns, and every of us, by ourselves, or by our deputy or
deputies, servants or agents, or such others as we, the said Harrison Grey Dyar
and John Hemming, our exors, adiñors, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend our said Invention within that part of Her United Kingdom of
Great Britain and Ireland called England, Her Dominion of Wales, and
Town of Berwick-upon-Tweed, in such manner as to us, the said Harrison
Grey Dyar and John Hemming, our exors adiñors, and assigns, or any of us,
should in our directions seem meet, and that we, the said Harrison Grey Dyar
and John Hemming, our exors, adiñors, and assigns, should and lawfully
might have and enjoy the whole profit, benefit, commodity, and advantage
from time to time coming, growing, accruing, and arising by reason of our
said Invention, for and during and unto the full end and term of fourteen
years from the date of these Presents next and immediately ensuing, and fully
to be complete and ended, according to the Statute in such case made and
provided; in which said Letters Patent there is contained a proviso, obliging
us, the said Harrison Grey Dyar and John Hemming, by an instrument in
writing under our hands and seals, or under the hand and seal of one of us,
particularly to describe and ascertain the nature of our said Invention, and
in what manner the same is to be performed, and to cause the same instru-
ment to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said Letters
Patent, as in and by the same, reference being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
Harrison Grey Dyar and John Hemming, do hereby declare that the nature
of our said Invention, and the manner in which the same is to be performed,
are described and ascertained in manner following (that is to say) :-
The nature of our Invention consists in the use of carbonate of ammonia
(that is, the sequi-carbonate or bicarbonate) in the manufacture of carbonate
of soda, by applying it to decomposed common salt, and also in afterwards
restoring or recovering the ammonia which has been so used, or the greater
part thereof, in such a way as to allow of its being used again to convert other
portions of common salt into carbonate of soda, thus repeatedly producing
successive portions of carbonate of soda from the same portion of ammonia.
To render the description of our process more intelligible, we divide it into
two parts; the first part being the description of our method of using the
sesqui-carbonate or bicarbonate of ammonia in the manufacture of carbonate

page_text: of soda; the second part being 'the description of our method of restoring
or recovering the ammonia, or the greater part thereof, in such a way as to be
again employed in converting other portions of common salt into carbonate
of soda.
As to the first part. -The carbonate of ammonia of commerce is what
chemists calls the sesqui-carbonate, and in describing our process we shall
use the term carbonate of ammonia as denoting the sesqui-carbonate; the
bicarbonate is not generally met with, but is to be preferred when it can be
obtained, and accordingly in reproducing the ammonia, we recommend the
process to be carried on in such manner as to produce as much of the
bicarbonate as possible. We take nearly equal quantities, by weight, of
common salt, otherwise called chloride of sodium, or muriate of soda, and of
carbonate of ammonia; we dissolve the common salt in as much water as is
barely sufficient to dissolve it, so as to constitute a fully saturated solution,
and when so dissolved we add to it the carbonate of ammonia in the solid
form, but bruised or pounded to a state of fine powder. We prefer that the.
common salt should be the substance dissolved, and to add to it the said
carbonate of ammonia in a pulverized state, but the result may be obtained by
dissolving the ammonia and adding the common salt in a state of powder, but
according to our experience this is not quite so well. We mix these well toge-
ther, and suffer them to remain thus mixed from ten to twenty hours, stirring.
or agitating them from time to time to prevent the solid parts from settling
before the chemical action is sufficiently complete. We then drain or filter the
perfectly as is con-
liquid from the solid matter, and in order to separate as
venient all the liquid from the solid matter, we press the substance in an
ordinary hydraulic or screw press, or submit it to considerable pressure by any
other convenient mode. The solid matter thus obtained is chiefly a carbonate
of soda, containing however more carbonic acid than is found in soda ash or
crystals of carbonate of soda of commerce: To remove this excess of carbonic
acid, and to recover any ammonia contained in the carbonate of soda, we next
place the solid matter so obtained as aforesaid in a retort or other convenient.
vessel, and heat it from about six hundred degrees to eight hundred degrees
of Fahrenheit until all the liquid and volatile matter contained in it is drawn off
by that heat. The substance left in the retort is the carbonate of soda. We
pass the matter thus volatilized into a cool chamber or refrigerating apparatus,.
an example of which is furnished by the lead balloons used in the condensation
of carbonate of ammonia in the usual manner, wherein the carbonate of
ammonia becomes condensed; but any convenient mode of condensing ammonia
may be adopted.

page_text: As to the second part.—The liquid separated from the solid matter (that i
to say) from the solid carbonate of soda, by the pressure in the operation
described in the first part of this Specification, or by filtration, contains in
solution muriate and carbonate of ammonia, common salt, and probably also
a small portion of the carbonate of soda formed. In order, therefore, to
separate the carbonate of ammonia therefrom, we place it in a distilling vessel
and distil over the water and the carbonate of ammonia, and receive the
product into a cask or proper vessel, which we keep filled with carbonic acid,
obtained from any economic source, in order to prevent loss of ammonia.
Or, instead of distilling over, as above described, the water and the carbonate
of ammonia, we add to the liquid a solution of muriate of lime or chloride of
calcium, which is one of the results of our process, until a precipitate, which
is chiefly carbonate of lime, ceases to fall. We separate this precipitated
carbonate of lime by filtration or other means from the liquid, which is then
chiefly a solution of muriate of ammonia and common salt. We evaporate
this by heat to a sufficient consistency to enable us to separate the common
salt (in cases where it is desirable to do so on account of the value of
common salt, which being less soluble in hot or boiling water than muriate
of ammonia, crystallizes first, and may be separated by well-known means
When the common salt is removed from the liquor (if desirable, or without
that process, if not though worth while,) we evaporate by gentle heat the
muriate of ammonia to dryness, and mix it intimately with a sufficient
quantity of powdered chalk, and heat the mixture in an iron retort or other
proper vessel until the carbonate of ammonia formed by this operation is
sublimed and separated in the usual way. We receive this carbonate of
ammonia in a chamber or vessel formed of lead or other suitable material,
where it becomes condensed, and we make a communication by means of a
pipe between this chamber or vessel and another chamber or chambers. Into
one or more of these chambers we cause the carbonic acid and other volatile
matters to pass, which were expelled by heat from the carbonate of soda, s
formed as before described in the first part of this Specification. We receive
the carbonic acid into one or more of these chambers for the purpose of
preventing loss of ammonia by converting free ammonia into carbonate of
ammonia or bicarbonate of ammonia, and if the carbonic acid from the soda
is not sufficient for this end we pass more into them, which we obtain from 3
coal, coke, charcoal, or any other economic source, as well as a sufficient
quantity of water or vapor of water to condense and save the ammonia. Or,
in order effectually to prevent the loss of ammonia, we pass into the last of
the vessels or chambers we employ to receive and condence the carbonate of

page_text: ammonia a sufficient quantity of muriatic acid gas, obtained by adding
sulphuric acid to common salt, or from any other economic source.
The
muriatic acid gas, combining readily with free ammonia or the carbonate of
ammonia in vapour, forms muriate of ammonia, and thus precipitates in the
chamber, by which operation we avoid any loss of ammonia that might
otherwise ensue. The muriate of ammonia thus obtained we treat in the
same manner as the muriate of ammonia separated from the liquids before
described, so that this muriate of ammonia may be converted into carbonate
of ammonia or bicarbonate. The carbonate of ammonia obtained, or repro-
duced, or recovered from distilling the muriate of ammonia with chalk, as
herein-before described, as well as that obtained by the distillation of the
liquid, as also herein-before described, or by any of the other modes herein-
before described, we employ over again to convert other portions of common
salt into carbonate of soda, according to the plan detailed in the first part of
this Specification. The common salt separated from the muriate of ammonia,
as before described, we again employ with other portions of common salt in
subsequent operations. The residue found in the retorts after the sublimation
of the carbonate of ammonia is chiefly muriate of lime or chloride of calcium,
which may be used as before mentioned.
In all the operations we have described for the manufacture of carbonate
of soda we employ vessels or apparatus of such construction as to expose the
carbonate of ammonia employed as little as possible to the air, so that loss
of ammonia may be prevented. We do not claim as our Invention any
particular form of vessels or apparatus in which our operations are conducted,
nor any of the chemical substances above mentioned, merely as such; but we
claim as our Invention or improvements the use of carbonate or bicarbonate
of ammonia in converting common salt into a carbonate of soda as herein-
before described; and as this mode would be too expensive to be profitable if
we could not recover the ammonia used for this purpose, so as to make it
available for repeated operations, we claim, in combination with the former
part, the process, as herein-before described, for recovering the ammonia which
would otherwise be wasted.
In witness whereof, I, the said Harrison Grey Dyar, have hereunto set
my hand and seal, this Twenty-ninth day of December, One thousand
eight hundred and thirty-eight.
:
HARRISON GREY (L.s.) DYAR.

page_text: AND BE IT REMEMBERED, that on the Twenty-ninth day of December,
in the year of our Lord 1838, the aforesaid Harrison Grey Dyar came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that
purpose.
Inrolled the Twenty-ninth day of December. in the year of our Lord