IMPROVEMENTS IN THE MANUFACTURE OF PAPER
Year: 1860

page_text: LETTERS PATENT to Theophilus Redwood, of 19, Montague Street,
Russell Square, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF PAPER."
Sealed the 11th December 1860, and dated the 12th June 1860.
PROVISIONAL SPECIFICATION left by the said Theophilus Redwood at
the Office of the Commissioners of Patents, with his Petition, on the
12th June 1860.
I, THEOPHILUS REDWOOD, of 19, Montague Street, Russell Square, in the
County of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF PAPER," to be as follows:-
This Invention consists in the use of sulphate and sulphite of barytes
mixed while in the recently precipitated and still moist state with rice or other
small grained starch, which mixture is to be added to the paper pulp in the
manufacture of paper, or to the size used for sizing paper.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Theophilus Redwood in the Great Seal Patent Office on the
12th December 1860.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Theophilus Redwood in the Great Seal Patent Office on the
12th December 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THEOPHILUS
5 REDWOOD, of 19, Montague Street, Russell Square, in the County of Mid-
dlesex. send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of June, in the year of our Lord One
thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Theophilus Redwood, Her special licence that I, the said Theophilus Red-
wood, my executors, administrators; and assigns, or such others as I, the said
Theophilus Redwood, 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 "IMPROVEMENTS IN
THE MANUFACTURE OF PAPER," upon the condition (amongst others) that I, the
said Theophilus Redwood, 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 Theophilus Redwood, do hereby declare
the nature of my said. Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement (that is to say) :-
My said Invention relates, firstly, to the use of sulphite of barytes in the
manufacture of paper. I produce the sulphite of barytes either by decom-
posing carbonate of barytes with a strong aqueous solution of sulphurous acid
or by adding sulphite of soda to chloride of barium in solution, but I prefer
the latter method. The sulphite of barytes, which is obtained as a white pre-
cipitate, is mixed with rice or other small-grained starch, and the mixture,
either in this state or after being dried, is added to paper pulp for the purpose
of preventing the injurious effects of chlorine or chlorine compounds in the
pulp, and in other ways improving the quality of the paper. I usually mix
one part of sulphite of barytes with about ten parts of starch, and this may be
added to the paper pulp in the proportion of one part of the mixture to about
ten parts of the fibre which is to enter into the composition of the paper,
estimating both in the dry state. These proportions, however, are not essential,
but are those I have found to be most suitable. The sulphite of barytes will
not only prevent the injurious effects of chlorine which may have been intro-
duced into the pulp in the process of bleaching, but will tend to protect the

page_text: paper, and also the writing ink which may be applied to it from destruction by
other oxidizing agents.
Secondly, my Invention relates to the use of sulphate of barytes, which is
mixed while in the recently precipitated and still moist state with some small-
grained starch, as in the preceding case. I produce the sulphate of barytes
by adding sulphuric acid or sulphate of soda to chloride of barium, and then
mix one part of the precipitate before drying it with about ten parts of starch,
estimating both in the dry state. This mixture may be added to paper pulp
in the same way and to the same extent as the mixture containing sulphite of
barytes already described; it improves the colour and texture of the paper,
and increases its strength. The sulphate and sulphite of barytes may be used
together, the two precipitates being mixed with starch, as already described,
before drying them.
Thirdly, my Invention relates to the use of sulphate and sulphite of barytes
mixed with starch, as already described in the sizing of paper. In applying
this part of my Invention, the mixture of sulphite of barytes, or sulphate of
barytes, or both, with starch is first mixed with boiling water in the proportion
of about one pound of the powder to two gallons of water, and one part of
this is added to about four parts of animal size, such as' is usually employed in
the sizing of paper. This mixture is used in the same way as animal size
alone is used.
In witness whereof, I, the said Theophilus Redwood, have hereunto
set my hand and seal, this Twelfth day of December, in the year of
our Lord One thousand eight hundred and sixty.
THEOPHILUS REDWOOD. (L.S.)