In. PROVEMENTS IN THE MANUFACTURE OF SUGAR
Year: 1871

page_text: LETTERS PATENT to James Paterson, of the Middle Temple, in the
County of Middlesex, Barrister-at-Law, for the Invention of "In.
PROVEMENTS IN THE MANUFACTURE OF SUGAR.”—A communication from
abroad by George Alexander Drummond, of Montreal, Canada.
PROVISIONAL SPECIFICATION left by the said James Paterson at the
Office of the Commissioners of Patents, with his Petition, on the
22nd August 1871.
I, JAMES PATERSON, of the Middle Temple, in the County of Mid-
5 dlesex, Barrister-at-Law, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SUGAR," com.
municated to me from abroad by George Alexander Drummond, of
Montreal, Canada, to be as follows :—
The object of the Invention is to facilitate the removal of iron and
0 other metals from the sugar during manufacture.
For this purpose
is employed according to this Invention mono-sulphide of one of the

page_text: alkaline earths, such as calcium, strontium, or barium in conjunction
with sulphate of magnesia. To the solution of sugar or the syrup is
added milk of lime, in quantity such as to make it slightly alkaline,
then there is added the prepared sulphide of barium, calcium, or
strontium either in powder, or by preference dissolved in water, and
the whole is thoroughly stirred at the temperature of, say, between
100° to 150° Fahrenheit. If the solution now gives a dark color to
paper moistened with acetate of lead the quantity of sulphide is
sufficient, if not more must be added. A quantity of sulphate of
magnesia in. solution is then added, at the rate of one and a half
pounds for every pound of sulphide of barium, or for every one half
pound of sulphide of calcium. The whole is thoroughly incorporated
and heated; a small quantity of blood or albumen facilitates subsequent
filtration. The whole is then passed through a filter, and is then ready
for the subsequent processes of refining. By this means iron or other 1
prejudicial metals are removed, together with any excess of lime, and
all the baryta, if this be used, is separated as a very insoluble sulphate.
The foregoing process may be varied, and the ordinary apparatus of
sugar refining is usually quite sufficient to carry it out effectually.
SPECIFICATION in pursuance of the conditions of the Letters Patent, a
filed by the said James Paterson in the Great Seal Patent Office
on the 21st February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
PATERSON, of the Middle Temple, in the County of Middlesex, Barrister-
at-Law, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of August, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Paterson, Her special licence
that I, the said James Paterson, my executors, dministrators, and
assigns, or such others as I, the said James Paterson, 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

page_text: 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 SUGAR," communicated to me from abroad by
George Alexander Drummond, of Montreal, Canada, upon the condition
(amongst others) that I, the .said James Paterson, 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 James Paterson, do hereby declare
the nature of the 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, that is to say :-
The object of the Invention is to facilitate the removal of iron and
other metals from the sugar during manufacture. For this purpose is
employed according to the Invention mono-sulphide of one of the
alkaline earths, such as calcium, strontium, or barium in conjunction
with sulphate of magnesia. To the solution of sugar or the syrup is
added milk of lime in quantity such as to make it slightly alkaline,
then there is added the prepared sulphide of barium, calcium, or
strontium, either in powder, or by preference dissolved in water, and
the whole is thoroughly stirred at the temperature of, say, between
100° to 150° Fahrenheit. If the solution now gives a dark color to
paper moistened with acetate of lead the quantity of sulphide is
sufficient, if not more must be added. A quantity of sulphate of
magnesia in solution is then added, at the rate of one and a half
pounds for every pound of sulphide of barium, or for every one half
pound of sulphide of calcium. The whole is thoroughly incorporated
and heated; a small quantity of blood or albumen facilitates subsequent
filtration. The whole is then passed through a filter, and is then ready
for the subsequent processes of refining. The amount of sulphide to
be used will depend upon the impurity of the sugar or syrup, but will
not exceed in most cases two or three pounds of sulphide of barium,
or about one half that quantity of sulphide of calcium to the ton of
sugar. By these means the iron or other metals held in solution as
oxides in the syrup are converted by the sulphide of the alkaline earth

page_text: into sulphides which are insoluble. The subsequent addition of sulphate
of magnesia converts any excess of the alkaline sulphuret into a very
unstable sulphide of magnesium, while the baryta if used is separated
as a wholly insoluble sulphate, which with the sulphide of iron and
other impurities is separated by filtration.
The foregoing process may be varied, and the ordinary apparatus of
sugar refining is usually quite sufficient to carry it out effectually.
E
Having thus described the Invention, as communicated to me, I
would have it understood that what I claim is, the use and application
of a mono-sulphide of barium, strontium, or calcium in conjunction]
with sulphate of magnesia for the purification of sugar, substantially as
above set forth.
In witness whereof, I, the said James Paterson, have hereunto set
my hand and seal, this Twentieth day of February, in the year
of our Lord One thousand eight hundred and seventy-two.
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