AN IMPROVEMENT IN THE MANUFACTURE OF PAPER
Year: 1857

page_text: LETTERS PATENT to David Baker, of the Gisbro' Alum Works,. York-
shire, for the Invention of "AN IMPROVEMENT IN THE MANUFACTURE OF
PAPER."
Sealed the 6th March 1857, and dated the 5th January 1857.
PROVISIONAL SPECIFICATION left by the said David Baker at the Office
of the Commissioners of Patents, with his Petition, on the 5th January
1857.
I, DAVID BAKER, of the Gisbro' Alum Works, Yorkshire, do hereby
declare the nature of the Invention for "AN IMPROVEMENT IN THE MANUFACTURE
OF PAPER," to be as follows:-
This Invention consists in the application of sulphate of magnesia, with or
without other ingredients in the manufacture of paper.
Hitherto it has been the practice to introduce a solution of alum into the
pulp used for the manufacture of paper. My improvement consists in the
application of sulphate of magnesia, either as manufactured from carbonate of
magnesia or magnesian limestone and sulphuric acid, or, as it can be obtained
from the alum liquors of the Yorkshire Alum Works.
The sulphate of magnesia is. introduced into the pulp either alone or com-
bined with one or all of the following substances, viz. -sulphate of alumina,
aluminous clay, sulphuric acid, and muriatic acid, as a substitute for or addi-,
tion to alumina in its various forms, or the alum of commerce now used in the
manufacture of paper.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Baker in the Great Seal Patent Office on the 2nd July
1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
BAKER, of the Gisbro' Alum Works, Yorkshire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of January, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said David
Baker, Her special licence that I, the said David Baker, my executors,
administrators, and assigns, or such others as I, the said David Baker, 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 vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "AN IMPROVEMENT IN THE MANUFACTURE OF PAPER," upon
the condition (amongst others) that I, the said David Baker, 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 David Baker, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
This Invention consists in the application of sulphate of magnesia, with or
without other ingredients in the manufacture of paper.
Hitherto it has been the practice to introduce a solution of alum into the
pulp used for the manufacture of paper. My improvement consists in the
application of sulphate of magnesia, either as manufactured from carbonate of
magnesia or magnesian limestone, and sulphuric acid, or, as it can be obtained
from the alum liquors of the Yorkshire Alum Works.
The sulphate of magnesia is introduced into the pulp either alone or com-
bined with one or all of the following substances, viz. :-sulphate of alumina,
aluminous clay, sulphuric acid, and muriatic acid, as a substitute for or
addition to alumina in its various forms, or the alum of commerce now used
in the manufacture of paper.

page_text: Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same. In place of employing
a solution of alum in the pulp, as heretofore, when making paper, a solution
of sulphate of magnesia is used; the paper making in other respects is carried
on in the usual manner, or in place of using sulphate of magnesia alone,
sulphate of alumina may be used therewith, or aluminous clay, in which case,
I prefer to employ five parts by weight of sulphate of magnesia and fifteen
parts of sulphate of alumina, and in some cases a portion of aluminous clay,
but other proportions may be used, and sulphuric and muriatic acids may also
be employed; in which case, I prefer to use such acid or acids in the propor-
tion of six pounds of the acid of commerce to 100 lbs. of the sulphates of
alumina and magnesia, and of aluminous clay, but the proportions may be
varied.
In witness whereof, I, the said David Baker, have hereunto set my hand
and seal, this First day of July, in the year of our Lord One thousand
eight hundred and fifty-seven.
Witness,
WM WEATHERILL,
of Guisbro', Yorkshire, Solicitor.
DAVID BAKER. (L.S.)