CERTAIN IMPROVEMENTS IN THE METHOD OF BLEACHING
Year: 1856

page_text: LETTERS PATENT to Pierre Isidor David, of Paris, in the Empire of
France, Machinist, for the Invention of "CERTAIN IMPROVEMENTS IN THE
METHOD OF BLEACHING."
Sealed the 12th August 1856, and dated the 13th February 1856.
PROVISIONAL SPECIFICATION left by the said Pierre Isidor David at
the Office of the Commissioners of Patents, with his Petition, on the
18th February 1856.
I, PIERRE ISIDOR DAVID, of Paris, in the Empire of France, Machinist, do
hereby declare the nature of my said Invention for CERTAIN IMPROVEMENTS IN
THE METHOD OF BLEACHING, to be as follows:-
My improvements in the method of bleaching are applicable to the bleaching
of cotton, either in the raw state, or more particularly when manufactured into
yarn or thread, and either in the cop or hank. The bleaching is effected by
means of chloroform in the state of gas as follows:-
1st, place the cotton in a closed wooden box, to which admit steam at a
pressure of four atmospheres, obtained from a boiler into which crystallized
soda shall have been admitted from time to time, after which remove it and.
let it stand to cool.
2nd, mix the following materials in an earthen vessel in about these pro-
portions: 3 lbs. of ordinary bleaching powder, 3 lbs. of slacked lime, lb. of
spirit (alcohol) of great strength, and 9 lbs. of water.
3rd, after mixing, add hydrochloric acid in about the proportion of 1 lb. to
the above-named quantities; chloroform in a gaseous state will be evolved.
4th, place the cotton after steaming and cooling in a wooden box lined with
lead, into which introduce the gas through an india-rubber tube till the cotton

page_text: is sufficiently bleached, then introduce hydrogen gas to expel the chloroform;
this having been done, again introduce chloroform gas obtained in the
following manner-Place bleaching powder, slaked lime, alcohol, and water,
mixed in the above proportions, in a zinc retort or vessel, heat them to 50° or
60° Reaumur (145° & 167° Fah,) and admit the gas disengaged thereby to
the cotton. To give the cotton a blueish colour, after the second admission of
chloroform gas admit into the lead-lined box.a current of. oxygen gas, which
may be obtained from water or manganese, and submitted before entering the
box to the action of an electric current by means of an electric battery.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Pierre Isidor David in the Great Seal Patent Office on the
13th August 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
ISIDOR DAVID, of Paris, in the Empire of France, Machinist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of February, in the year of our
Lord One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Pierre Isidor David, Her especial license that I, the said Pierre Isidor
David, my executors, administrators, and assigns, or such others as I; the said
Pierre Isidor David, 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 "CERTAIN IMPROVEMENTS
IN THE METHOD OF BLEACHING," upon the condition (amongst others) that I, 'the
said Pierre Isidor David, by an instrument in writing under my hand and seal,
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
immédiately after the date of the said Letters' Patent.
NOW KNOW YE, that I, the said Pierre Isidor David, 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 following
statement (that' is to say):
My improvements in the method of bleaching are applicable to the bleaching

page_text: of cotton, either in the raw state, or more particularly when manufactured into
yarn or thread, and either in the cop or bank. The bleaching is effected by
means of chloroform in the state of gas as follows:-
First, place the cotton in a closed wooden box, to which admit steam at a
pressure of four atmospheres, obtained from a boiler into which crystallized soda
shall have been admitted from time to time, after which remove it and let it
stand to cool.
Secondly, mix the following materials in an earthen vessel in about these
proportions: three pounds of ordinary bleaching powder, three pounds of
slacked lime, a quarter of a pound of spirit (alcohol) of great strength, and nine
pounds of water.
Thirdly, after mixing, add hydrochloric acid in about the proportion of one
pound to the above-named quantities; chloroform in a gaseous state will be
evolved.
Fourthly, place the cotton after steaming and cooling in a wooden box
lined with lead, into which introduce the gas through an india-rubber tube
till the cotton is sufficiently bleached, then introduce hydrogen gas to expel
the chloroform; this having been done, again introduce chloroform gas
obtained in the following manner:-Place bleaching powder, slacked lime,
alcohol, and water mixed in the above proportions, in a zinc retort or vessel,
heat them to 50° or 60° Reaumur (145° & 167° Fahrenheit), and admit the
gas disengaged thereby to the cotton. To give the cotton a blueish color,
after the second admission of chloroform gas admit into the lead-lined box a
current of oxygen gas, which may be obtained from water or manganese, and
submitted before entering the box to the action of an electric current by means
of an electric battery.
In witness whereof, I, the said Pierre Isidor David, have hereunto set my
hand and seal, the Ninth day of August, in the year of our Lord
One thousand eight hundred and fifty-six.
)
Witness,
PIERRE ISIDOR DAVID. (L.S.)
BLONDEAU,
Rue d'Angoulème, du Temple, No. 16,
à Paris.