CERTAIN IMPROVEMENTS IN THE MA- NUFACTURING OR PRODUCING SODA AND OTHER ARTICLES OBTAINED BY OR FROM THE DECOMPOSITION OF COMMON SALT OR CHLORIDE OF SODIUM
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANTOINE
BLANC, of Paris, in the Kingdom of France, Merchant, now residing at
Sablionere's Hotel, Leicester Square, in the County of Middlesex, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twelfth day of February, in the third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Antoine Blanc and THÉOPHILE GERVAIS BAZILLE, of Rouen, in the Kingdom
of France, Merchant, Her especial licence, full power, sole privilege and
authority, that we, the said Antoine Blanc and Théophile Gervais Bazille,
our executors, administrators, and assigns, and such others as we, the said
Antoine Blanc and Théophile Gervais Bazille, our executors, administrators,
or assigns, should at any time agree with, and no others, from time to time and
at all times during the term of years therein mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, an Invention of "CERTAIN IMPROVEMENTS IN THE MA-
NUFACTURING OR PRODUCING SODA AND OTHER ARTICLES OBTAINED BY OR FROM THE
DECOMPOSITION OF COMMON SALT OR CHLORIDE OF SODIUM," being a communication
from a Foreigner residing abroad; in which said Letters Patent is contained

page_text: a proviso obliging us, the said Antoine Blanc and Théophile Gervais Bazille,
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 the
said Invention, and in what manner the same is to be performed, and to cause
the same to be inrolled in Her Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part recited
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, I, the said
Antoine Blanc, on behalf of myself and of the said Theophile Gervais Bazille,
do hereby declare that the nature of the said Invention, and the manner in
which the same is to be performed, are particularly described and ascertained
in and by the following description thereof, that is to say:-
Our process consists in decomposing sea salt by silica and water under the
influence of a strong heat. The action of silica on sea salt under the influence
of water and heat is a fact which has been long known in chemical science,
but hitherto no application has been made of it upon the great scale in the
arts for the manufacture of soda. When in the laboratory an intimate mixture
is made of sea salt and sand, and when that mixture is exposed to the action
of a cherry-red heat in a large porcelain tube, a decomposition of the mass
takes place when the vapour of water is made to pass over it, and there results
a neutral silicate of soda insoluble in water, while hydrochloric or muriatic
acid is disengaged, and may be received or condensed in water. This fundi-
mental fact has been several times verified, and the process never fails when
performed with care. The vapour of water in decomposing transforms the
mass into a proportion more or less considerable of silicate of soda at the
extremity of the porcelain tube, to which a tube of glass may be adapted,
destined to conduct the acid gas into a vessel full of distilled water. After
some hours of ignition the liquor becomes strongly acid, and this liquid muriatic
acid is not coloured in the least yellow, as the acid of commerce usually is by
the presence of iron. The mass withdrawn from the tube is to be lixiviated
to carry off all the undecomposed sea salt, and the remainder is to be mixed
with a little carbonate of soda. This mixture being fused in a crucible forms
a vitrified mass consisting of a sub-silicate of soda soluble in water. This
sub-salt is to be dissolved in water, and to be transformed as follows into
carbonate of soda and gelatinous silica. This is effected by passing a stream
of carbonic acid gas through the solution, whereby white flakes of silica are
deposited, and there remains in solution only carbonate of soda, which may be
evaporated and calcined and disposed of as dry soda or soda ash, or formed

page_text: into crystals. Upon the great scale the transformation of sea salt into neutral
silicate of soda may be conveniently performed as follows:-The calcination of
sea salt and siliceous sand may be made in cast-ironi cylinders placed in fur-
naces so that the flame may pass round them and raise them to a cherty-red
heat. The arrangement of these cylinders may be the same as those of gas
retorts. The axis of each cylinder is occupied by a large tube of the same
length as the cylinder, which tube is pierced with a multitude of holes. This
tube is inserted at one end of each cylinder; into the other end of cach
cylinder a large porcelain, stoneware, or glass tube is adapted, through which
the muriatic gas is allowed to pass off. Each cylinder is to be filled loosely by
very moderate pressure with an intimate mixture of sea salt and sand, and
when the mass has arrived at a cherry-red heat the steam of water is made to
pass from a steam boiler into the perforated tube which traverses the cylinder.
For the due success of the operation the workman charged with its manage.
ment should allow the steam to pass very slowly into the tube and very
equably. If too much steam be introduced into the tube the iron cylinder
might be forcibly expanded and loose its shape. In fact the steam should
not be admitted so quickly as to lower the temperature of the mixture
beneath a cherry-red heat; when this is attended to the water is decom-
posed in the apparatus, and the transformation of sea salt and sand into
neutral silicate of soda goes on without risk and in a complete manner.
The proportions of the materials to be employed to obtain a good decomposition
are, sea salt two hundred and eighty parts, sand two hundred parts. Chemical
theory indicates that two hundred and fifty parts of sea salt require for their
transformation into neutral silicate of soda under the influence of water one
hundred and ninety-eight parts of pure silica or silicic acid; but as a certain
quantity of the sea salt is volatilized before acting upon the sand, it is proper
to employ a somewhat larger proportion of salt. The proportions stated
above are such as practice has shewn to be suitable. As this acid has a
certain value in commerce, and as in certain localities large quantities are
employed, especially for the manufacture of chlorine, it is frequently important
to collect this gas instead of allowing it to pass off by the chimney. The tube
adapted to the cylinder for the disengagement of the acid gas should be very
large, especially at its orifice, for otherwise it might be choked up by volati-
lized sea salt. The tube that carries of the gas is to enter first of all into a
large empty chamber, into which the volatilized salt may be condensed an:1
deposited. This chamber is to communicate with a large cistern of wood or
stone, having its bottom covered with water. By this arrangement, and by
employing sufficiently large vessels, we may collect the acid gas with little or

page_text: no pressure, while the apparatus of Woulfe, usually employed in the preparation
of muriatic acid, requires a series of twenty or thirty bottles and considerable
pressure. Before proceeding to the transformation of the neutral silicate into
sub-silicate, the mass is to be lixiviated as above stated, in order to extract
the undecomposed portion of sea salt. The neutral silicate of soda obtained
in this first operation being insoluble, it must be rendered a soluable sub-salt
by combining it with an additional proportion of soda. Sixty parts of carbo-
nate of soda must be employed to convert one hundred parts of neutral silicate
into sub-silicate of soda. There is, however, no inconvenience in employing.
a little excess of carbonate, as this salt is not liable to be decomposed by heat,
and remains always in the solution. The apparatus destined to calcine this
mixture is either an ordinary reverberatory furnace or a large Hessian crucible:
At a cherry-red heat the vitrification takes place, and the matter in this state
is soluble in hot water. The insoluble silicate, however, may be employed in
the manufacture of glass, with suitable additions of lime and alumina. The
vitrified sub-silicate of soda ought to be pulverized and thrown into hot water
to effect its solution. This solution may be made in large wooden or stone
reservoirs. The process which we have found most advantageous and have
adopted for obtaining carbonic acid consists in extracting it from limestone
by calcination in continuously acting lime kilns. To the lime kiln a dome
top is adapted, furnished with a tube that passes into the vessels or vessel
containing the solution of sub-silicate. The sub-silicate of. soda is decomposed
in this operation, carbonate of soda being formed, which remains in solution,
and gelatinous silica being deposited. The operation is finished whenever the
carbonic acid ceases to be absorbed by the solution. This silicic acid may be
obtained as a white jelly when the carbonic acid is free from smoke, in
which state it is well adapted for the manufacture of fine glass... Care must be
taken not to employ too great a number of vessels in effecting the transforma-
tion of sub-silicate of soda into carbonate, because in that case the pressure
would be too considerable, and would obstruct the flow of air through the
lime kiln, and the proper calcination of the lime. With this view we prefer
employing a single vessel of very large capacity, and we find the operation
goes on perfectly well and the draught of the furnace goes on sufficiently
well to maintain uninterrupted combustion to the end of the process.
In witness whereof, I, the said Antoine Blanc, have hereunto set my
hand and seal, this Twelfth day of August, in the year of our Lord
One thousand eight hundred and forty.
A. BLANC. (L.S.)

page_text: AND BE IT REMEMBERED, that on the same Twelfth day of August,
in the year above mentioned, the aforesaid Antoine Blanc came before our
Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained, in form above written
(the same having been translated to him by Alexis Simonin, his interpreter,
the said interpreter having declared duly to interpret the same). And also the
Specification aforesaid was stamped according to the tenor of the Statute in
that case made and provided.
Inrolled the same Twelfth day of August, in the year above written.