A IMPROVED MODE OF CONVERTING VEGETABLE FIBROUS SUBSTANCES INTO PULP
Year: 1861

page_text: LETTERS PATENT to John Watt, of No. 2, Westmoreland Place, Cam-
berwell, in the County of Surrey, Chemist, for the Invention of "A
IMPROVED MODE OF CONVERTING VEGETABLE FIBROUS SUBSTANCES INTO PULP."
Sealed the 3rd December 1861, and dated the 12th June 1861.
PROVISIONAL SPECIFICATION left by the said John Watt at the Office
of the Commissioners of Patents with his Petition, on the 12th June
1861.
I, JOHN WATT, of No. 2, Westmoreland Place, Camberwell, in the County
of Surrey, Chemist, do hereby declare the nature of the said Invention for
"AN IMPROVED MODE OF CONVERTING VEGETABLE FIBROUS SUBSTANCES INTO PULP,"
to be as follows:-
This Invention relates to a peculiar mode or process for converting vegetable
fibrous substances into pulp. To effect this object, the vegetable fibrous sub-
stance to be employed is placed in a boiler or other suitable vessel, which
boiler or vessel is then to be nearly filled with water, proto-carbonate of soda,
or bi-carbonate of soda, or proto-carbonate of potassa, or bi-carbonate of potassa
or soda ash is to be added to the contents of the boiler or vessel in a quantity
sufficient to form a saturated solution at the boiling temperature. The
contents of the boiler or vessel are then to be heated to boiling, and kept
boiling until the solution becomes so concentrated that crystallization or
solidification of the carbonate or salt employed will take place on the cooling

page_text: of the liquid contents of the boiler or vessel. During the boiling, evaporation
or loss of water will take place; the loss thereby sustained is to be com-
pensated for by an occasional supply of water equal to the loss sustained by
evaporation. When the fibrous substance has been sufficiently boiled, the
solution or liquid is run off from the boiler or vessel containing it into a vessel
ready for its reception. The fibrous substance remaining in the boiler or
vessel is then to be thoroughly washed in the water in any convenient manner,
in order to free it from alkali and other impurities. The fibrous substance is
then to be immersed in or covered with a solution of chloride of lime or soda,
and the whole may be then heated by means of steam pipes, or other suitable
apparatus. By these means the fibrous substance employed will become con-
verted into and form pulp.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Watt in the Great Seal Patent Office on the 11th
December 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WATT, of No. 2, Westmoreland Place, Camberwell, in the County of Surrey,
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victorin, by Her Letters
Patent, bearing date the Twelfth day of June, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for erself, Her heirs and successors, give and grant unto
me, the said John Watt, Her special licence that I, the said John Watt,
my executors, administrators, and assigns, or such others as I, the said
John Watt, 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 IMPROVED MODE OF
CONVERTING VEGETABLE FIBROUS SUBSTANCES INTO PULP," upon the condition
(amongst others) that I, the said John Watt, 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 Inven-
tion, 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.

page_text: NOW KNOW YE, that I, the said John. Watt, do hereby declare
the nature of my 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 relates to a peculiar mode or process for converting
vegetable fibrous substances into pulp, and consists in subjecting the vegetable
fibrous substance to the action of proto-carbonate of soda, or bi-carbonate
of soda, or proto-carbonate of potassa, or bi-carbonate of potassá, or soda
ash in solution in water, and heating the whole to the boiling point, and
boiling the same until the fibrous substance has been so acted upon that on
being washed and treated with an aqueous solution of chloride of lime or
chloride of soda it is converted into pulp.
And in order that the said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the method by which I
prefer to proceed.
The vegetable fibrous substance to be employed is placed in an open boiler
or other suitable vessel with a sufficient quantity of water to cover the
vegetable fibrous substance. Proto-carbonate of soda, or bi-carbonate of soda,
or proto-carbonate of potassa, or bi-carbonate of potassa, or soda ash, is then to
be added to the contents of the boiler or vessel in a quantity sufficient to form
a saturated or nearly saturated solution at the boiling point. The contents of
the boiler or vessel are then to be heated to boiling point, and the boiling is
to be continued until the solution becomes so concentrated by evaporation
that crystallization or solidification of the carbonate employed will take place
on the cooling of the liquid contents of the boiler or vessel, which condition of
such contents may be ascertained by taking out during the process a small
quantity thereof, and allowing it to cool, when if sufficiently concentrated,
crystals of the carbonate employed will be deposited; in some cases, and
especially when the vegetable fibrous substance has a hard silicious coating,
the boiling may be continued until the carbonate enters into aqueous fusion.
When either of these conditions is attained, it will be found that considerable
evaporation of the water has taken place, and a consequent diminution or loss
in quantity thereof has been occasioned. This diminution or loss is to be then
compensated for by a supply of water to the contents of the boiler or vessel
equal to the less in quantity occasioned by evaporation. And similar additions
of water are to be repeated, and the boiling continued, and similar evaporations
allowed to take place, until the condition of the fibrous substance is such that
when taken out of the boiler and washed, and then steeped in a solution of.
chloride of lime or chloride of soda, it becomes converted into pulp, and

page_text: bleached; this condition of the fibrous substance will be readily ascertained by
taking a small portion of it from time to time during the process, and treating
it in the manner described. When the fibrous substance has been sufficiently
boiled it may be removed from the solution, and placed in any suitable vessel,
or the solution may be run off from the boiler or vessel containing it. The
fibrous substance is then to be washed with water in any convenient manner,
in order to free it from any alkali and other matters remaining about it. The
washing should be continued until the water employed runs off colorless. The
fibrous substance is then taken from the boiler or vessel containing it, and placed
in a bleaching cistern or other suitable apparatus, and immersed in a strong
aqueous solution of chloride of lime or chloride of soda. The cistern or other
suitable apparatus, and the contents thereof, may then be gently and slightly
heated by means of steam pipes or other suitable apparatus.
1:
In witness whereof, I, the said John Watt, have hereunto set my hand
and seal, this Eleventh day of December, One thousand eight hundred
and sixty-one