CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF SODA;
Year: 1845

page_text: BROWN'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
BROWN, of Glasgow, in Scotland, Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Charter
of Donation or Letters Patent under the Great Seal of Great Britain, bearing
date at Westminster, the Twentieth day of February, (Eighteen hundred and
forty-five,) in the eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said George Brown, my exors, admiors,
and assigns, Her especial permission, licence, and full power, sole privilege and
authority, that I, the said George Brown, my exors, admors, and assigns, by
myself or ourselves, or such other person as I or they should appoint or agree
with and no others, from time to time and at all times thereafter during the
term of years therein written; should and lawfully might make, use, exercise,
and vend, my Invention for "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF
SODA;" within England, and Wales, and the Town of Berwick-upon-Tweed,
and also in all Her said Majesty's Colonies and Plantations abroad, in such
manner as I, the said George Brown, my exors, adñiors, and assigns, or any
of us, should in my or our discretion seem meet, and that I and they should
have and enjoy all profits, benefits, and emoluments arising from the said
Invention from time to time during the term of fourteen years therein men-
tioned; in which said Letters Patent is contained a proviso, that I, the said
George Brown, within the space of six calendar months from the date of the
said Letters Patent, should particularly describe the nature of my said
Invention, and in what manner the same is to be performed, by a writing
under my hand and seal, and cause the same to be enrolled in Her said

page_text: Majesty's High Court of Chancery, in and to which Letters Patent, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, it is hereby
declared that the nature of my said Invention, and the manner in which the
same is to be performed, are fully described and ascertained in and by the
following description :-
My Improvement relates to a certain process whereby the sulphuret of
sodium produced in the manufacture of soda is oxydised and so transformed
into sulphate, sulphite, or hypo-sulphite of soda. The object and effect of my
improvement is to transform the sulphuret of sodium, which at present is
contained in soda, into sulphate, sulphite, or hypo-sulphite of soda, and so to
produce soda free from those qualities or that character whereby it is less fitted
than it otherwise would be for the purpose of soap making, bleaching, and
other like uses. The process whereby my improvement is effected consists in
fluxing the soda containing sulphuret of sodium with a sufficient quantity of
nitrate of soda, chlorate of soda, chlorite of soda, or other body possessing an
oxydizing power, but in most cases I prefer the nitrate of soda.
And in order that this process may be fully understood, I will proceed to
describe the ways that I usually adopt:-The liquor drawn from crude soda is
Loiled down in a pan or furnace until about four-fifths of the salt are precipitated.
In this state the whole mass (i.e. the remaining liquor, salt, &c.) is removed from
the furnace, and the wet pasty salt allowed to remain some time in a convenient
vessel to drain; by this means the greatest proportion of the liquor which
remained in the mass, and which is known to manufacturers by the name of
red liquor, will be separated from it. This red liquor which consists chiefly of
caustic soda and sulphuret of sodium with a certain proportion of neutral salts,
such as sulphate of soda and common salt, is brought into a metal pan and
evaporated to about the consistency of tar; the proper quantity of nitrate of
soda is then added and heat applied to expel the remaining water and flux the
mass. The application of the heat causes copious fumes of ammonia to be
exhaled and the mass froths and bubbles up, which serves as a guide to the
operator in adding the nitrate of soda. When there is no more ebullition on
the addition of a fresh portion of nitrate of soda he may be assured that the
proper quantity of nitrate of soda has been added, although it is better that
the whole of the nitrate of soda requisite should be added before all the water
is expelled. When the mass is brought to a quiet flux it is run out into
moulds, and it is in this state fit for the purposes of the consumer. Another
way by which I effect my improvement is to boil down the whole quantity of
crude.soda liquor, and during the boiling when the liquor is brought to about

page_text: the consistency of tar to add the nitrate of soda or other oxydizing body,
and the evaporation being completed, flux the soda containing the sulphuret of
sodium. In this way the same appearances serve as a guide to the operator in
adding the nitrate of soda or other oxidising body, but the ebullition and
frothing are not so marked and therefore more attention is required.
Be it well understood, that I do not confine myself to the particular ways
above described; but what I claim as my Invention is my improvement in
soda making by fluxing the soda containing sulphuret of sodium with bodies
possessing an oxydising power..
In witness whereof, I, the said George Brown, have hereunto set my
hand and seal, at Glasgow, the Eleventh day of August, One
thousand eight hundred and forty-five years.
Enrolled the Sixteenth day of August, in the year of our Lord One
thousand eight hundred and forty-five.