CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF PRUSSIAN BLUE, PRUSSIATE OF POTASH, AND PRUSSIATE OF SODA
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SWINDELLS, of Manchester, in the County of Lancaster, Manufacturing
Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Seal of Great Britain, bearing date at West-
minster, the Sixteenth day of April One thousand eight hundred and thirty-
nine, in the second year of the reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Swindells, Her especial
licence, full power, sole privilege, and authority that I, the said John
Swindells, my executors, administrators, and assigns, and such others as I.
the said John Swindells, my executors, administrators, and assigns, should at
any time agree with, and no other, from time to time and at all times during
the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, and Wales, and the Town of Berwick-upon-
Tweed, my Invention of "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF
PRUSSIAN BLUE, PRUSSIATE OF POTASH, AND PRUSSIATE OF SODA;" in which said
Letters Patent is contained a proviso that I, the said John Swindells, shall
cause a particular description of the nature of my said Invention, and in
what manner the same is to be performed, to be enrolled 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.

page_text: NOW KNOW YE, that in compliance with the said. proviso, I, the said
John Swindells, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, is particularly described and
ascertained in and by the following explanation thereof, that is to say :-
My Invention of an improved method of manufacturing prussiate of potash,
prussiate of soda, and Prussian blue, consists in producing the same during
the process of manufacturing carbonate of potash, carbonate of soda, and
British alkali, commonly called soda ash. The common method pursued in
manufacturing these articles is by forming a mixture of the sulphate of potash
or sulphate of soda, lime, or carbonate of lime and small coal, or any other
carbonaceous matter, and subjecting them to heat in reverberatory furnace,
and thereby decomposing the sulphates, and producing carbonate of potash or
sóda, and likewise a quantity of of sulphuret of potassium or sodium,
according to the article operated upon. In my process I dispense with lime
or carbonate of lime, and use along with the various sulphates a quantity of
ground coal of the best caking description, and also a quantity of iron filings
or borings, in manner following, namely:-I take any quantity of the sulphate
of potash or sulphate of soda, and fuse them in a reverberatory. furnace, such
as commonly used in the manufacture of alkalies, and then I add by degrees
a mixture of small caking coal and iron filings (in the proportion of one part
of iron filings to eight of coal, until I have added to the fused sulphate one
half their weight of coal, or more if the sulphates require it, taking care to
stir the materials well during the addition of the coal and iron filings,
and also for ten or fifteen minutes after the whole of the coal is added, when
the material will be ready to remove from the furnace and allowed to cool. I
also produce the same results by mixing in the first instance the coal and iron
filings with the various sulphates, and then fusing them in the furnace in the
usual way, or the iron filings may be omitted in the process, but I prefer the
addition thereof. The materials after being cooled I take and dissolve in water,
and when the solution has subsided, I evaporate the same until it has obtained a
specific gravity of 1.320 at a boiling heat, then I transfer it into coolers, when
the prussate of potash or prussiate of soda chrystallizes in the course of four
or five days; the solution now will consist of carbonate of potash or soda, and
sulphuret of potassium or sodium, which sulphuret may be removed by the
usual methods employed for that purpose. The chrystals of prussiate of potash
or prussiate of soda will require to be redissolved and rechrystallized, when
they will be ready for use or sale, or they may be manufactured into Prussian
blue in the usual way.
Having now fully described my Invention, and in what manner the same is

page_text: to be performed, I desire it to be understood, that I claim as my Invention
the production of prussiate of potash, prussiate of soda, and Prussian blue
therefrom, by these methods of decomposing the sulphates of potash and sul-
phate of soda, by caking coal and iron filings in the manufacture of potash and
soda from these substances, thereby producing both articles by one operation.
In witness whereof, I, the said John Swindells, have hereunto set my
hand and seal, the Eleventh day of October, One thousand eight
AND BE IT REMEMBERED, that on the Eleventh day of October, in the
third year of the reign of Her Majesty Queen Victoria, the said John Swindells
came before our said Lady the Queen in Her Chancery, and acknowledged the
instrument aforesaid, and all and every thing therein contained and specified,
in form above written. And also the instrument aforesaid was stamped
according to the tenor of the Statute made in the fifty-fifth year of the reign
of His late Majesty King George the Third.