IMPROVEMENTS IN BLEACHING FIBROUS SUBSTANCES
Year: 1864

page_text: LETTERS PATENT to Harold Potter, of the City of Manchester, Com-
mission Agent, for the Invention of "IMPROVEMENTS IN BLEACHING FIBROUS
SUBSTANCES."
Sealed the 16th December 1864, and dated the 13th September 1864.
PROVISIONAL SPECIFICATION left by the said Harold Potter at the
Office of the Commissioners of Patents, with his Petition, on the 13th
September 1864.
I, HAROLD POTTER, of the City of Manchester, Commission Agent, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN BLEACHING
FIBROUS SUBSTANCES," to be as follows:-
My Invention is particularly applicable in bleaching jute and the waste of
flax, but it may be employed in bleaching other fibrous substances.
The fibrous substance to be bleached is first bowked in the ordinary
manner, it is then washed with water and then subjected to the action of a
solution of sulphuric or other suitable acid; it is then again washed and
afterwards treated with an alkali. The fibrous substance with the alkali is
then submitted to the action of chlorine gas, after which it is again bowked
and washed; it is then placed in a pan in which a vacuum is formed, and a
solution of chlorine liquor is admitted and passed through the fibrous sub-
stance. The operations of forming a vacuum and passing the solution of
chlorine liquor are repeated as often as may be required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Harold Potter in the Great Seal Patent Office on the
9th March 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HAROLD
POTTER, of the City of Manchester, Commission Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of September, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
mo, the said Harold Potter, Her special license that I, the said Harold
Potter, my executors, administrators, and assigns, or such others as I,
the said Harold Potter, 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 BLEACHING FIBROUS SUBSTANCES," upon
the condition (amongst others) tlint I, the said Harold Potter, 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 Oflice within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Harold Potter, 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:
My Invention is particularly applicable in bleaching juto and the outer
bark or waste of flax, commonly called "shove" or "shew," and it consists in
certain improvements upon the Invention for which Letters Patent were
granted to me on the Twenty-fifth day of August, One thousand eight hundred
and sixty-four, Number 2097.
The shove or other fibrous substance to be blenched is first bowked or
boiled in an alkaline solution in the manner well known to bleachers; it is
then washed with water, and then subjected to the action of a solution of
sulphuric or other suitable acid of the strength of one or two degrees of
Twaddle's hydrometer; it is then again washed with water to remove the

page_text: acid, and afterwards it is steeped in an alkaline solution of the strength of
about one or two degrees of Twaddle's hydrometer, in which it remains for
about one hour. The "shove" or other fibrous substance with the alkali is
then hung on to rails placed horizontally in a closed chamber and submitted
for about ten or twelve hours to the action of chlorine gas, which may be
generated by pouring sulphuric acid on a mixture of manganese and common
salt placed in a leaden still and heated by a steam casing, or the chlorine gas
may be produced in any other convenient manner.
The various processes above described are similar to those mentioned and
referred to in the Specification of the Patent granted to me on the Twenty-
fifth day of August, One thousand eight hundred and sixty-four, Number
2097, after which the fibrous substance is removed from the closed chamber
and again bowked or boiled in an alkaline solution and then washed; the
fibrous substance is then placed in a covered pan, in which a partial vacuum
is formed to prepare the fibrous substance for being impregnated with a
solution of chlorine liquor of about five degrees of Twaddle's hydrometer,
which is admitted into the covered pan and passed through the fibrous sub-
stance. The operations of forming a partial vacuum and admitting a solution
of chlorine liquor are repeated as often as may be found requisite to remove
the impurities from and to bleach the fibrous substance. The chlorine liquor
may then be washed out to complete the operation.
I wish to observe that the strengths of the solutions named and the time
required for the various processes may be considerably varied, according to
the nature of the fibrous substances to be bleached.
In witness whereof, I, the said Harold Potter, havo hereunto set my
hand and seal, this Sixth day of March, One thousand eight hundred
and sixty-five.