IMPROVEMENTS IN BLEACHING COTTON
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE:
ISIDOR DAVID, of Paris, in the Republic of France, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-eighth day of
February, One thousand eight hundred and forty-nine, in the twelfth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Pierre Isidor David, my exors, admors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Pierre Isidor
David, my exors, admors, and assigns, and such others as I, the said Pierre
Isidor David, my exors, admors, or assigns, should at any time agree with;
and no others, from time to time and at all times during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, and in the
Islands of Guernsey, Jersey, Alderney, Sark, and Man, and in all Her said
Majesty's Colonies and Plantations abroad, my Invention of "IMPROVEMENTS
IN BLEACHING COTTON;" in which said Letters Patent is contained a proviso
that I, the said Pierre Isidor David, should cause a particular description of
the nature of my said Invention, and in what manner the same is to be
performed, by an instrument in writing under my hand and seal, to be

page_text: inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Pierre Isidor David, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, reference being had
to the Drawings hereunto annexed, and to the figures and letters marked
thereon, that is to say :-
The Invention consists of improvements in bleaching cotton by means of
chlorine gas, as will be more particularly described. I will first proceed to
describe the apparatus by which I carry out my Invention!
DESCRIPTION OF THE DRAWINGS,
A is a retort with two tubes, placed upon a furnace in a sand bath. B, a leaden
pipe for the introduction of muriatic acid into the retort through the cock No. 7.
C, another leaden pipe for conducting the chlorine gas from the retort to the
vessel E. D, D, are leaden pipes for conducting the gas and connecting the
vessels E', E², E³, E, together. The pipe C' conducts the gas into the chamber F.
These vessels E, E, E, E, E, may be of glass, or other material resisting the
action of acids, and they serve for the purifying, washing, and drying of the
gas; that of E' is empty, and receives the impurities of the gas; those of E
and Es are half filled with water, and the fourth E' is half filled with sulphuric
acid sixty-six degrees. More vessels with water, and more with acid, may be
employed if desired; the liquids in these vessels are to be withdrawn when
they become too much charged. Z are tubes of glass. In each of the vessels,
F is a box of wood or other suitable material which will resist the action of
the gas. At the lower part of this chamber or box is a false bottom of lead
pierced with holes above the opening of the pipe of introduction c', on to
which the cotton to be bleached is placed so as to leave an empty space below to
facilitate the action of the gas. There is a small window of white glass placed
upon one side of the box, and another on the cover, through which may be
seen the progress and end of the operation of bleaching. G is a leaden pipe
with a cock 3 for conducting the air from the blowing, machine V into
the vase H, which is half filled with quick lime in lumps to absorb the
humidity of the air, from whence it passes through the cock 2 into the
chamber F. K is the framing of the machinery. L is a vase with two tubes
furnished with material proper for producing a vapor, as will be explained

page_text: in treating the manner of working. M, M, are pipes furnished with cocks
Nos. 4 and 5, through which the gas escapes so as to saturate the cotton after
bleaching and ventilating, and to renew the ventilation if desired. T is the
discharge pipe upon the box F, with cock No. 6 for the passage away of the
gas. Upon this pipe, between the box and the cock, is a small opening O,
kept closed hermetrically, and serving for expulsion of air in case of need
during the bleaching, when the pressure of the gas becomes too great,
which will be indicated by the elevation of the water in the tubes Z, or tubes
serving as manometres, which should show an elevation of about fifteen inches
when the gas is working at the proper pressure. This elevation becomes
greater according to the state of the cotton, whether yarn or cloth, that is to
say, as it is more or less compressed in the box. V is a blowing machine or
air pump or ventilator, which may be worked by hand or other power. X, pipe
branched upon
that of C, and furnished with a cock No. 8, communicating
with a chimney. The cocks are to be formed of materials to resist the action
of acids and of chlorine gas, may be of lead, with a fifth part of antimony, or
of other metal or composition. The part of the pipe C' between the vase of
sulphuric acid and the chamber or case F, I prefer to make of vulcanized
caoutchouc..
I will now describe the manner of carrying out the Invention. The box F
is to be filled with cotton, either in the raw state, or yarn or thread in a woven
state, and without other humidity than that which is natural to it. Whether
the box be wholly or partially filled it must be closed hermetically in order to
prevent the escape of gas. The vases or vessels E', E, E³, E, being perfectly
stopped, I introduce into the retort A placed upon the furnace (but first
rinsed) a quantity of peroxide of manganese in lumps, in weight four per cent.
of that of the cotton to be bleached, if this peroxide gives eighty per cent. of
pure matter, if not a quantity proportioned to its degree of purity, so as to
obtain its equivalent. The pipes B and C are then adjusted upon the retort,
as it is indicated in the accompanying Drawing, and fastened thereto. The
cocks Nos. 7 and 8 are then opened. Place upon the pipe B a funnel in
glass or in lead, through which I pour into the retort the acid, hydrochloric
(muriatic), of twenty-one to twenty-two degrees, French, in quantity three
times heavier than that of the peroxide of manganese, diminishing in proportion
as the manganese gives less than eighty per cent. of pure matter, and con-
formable always to the ordinary mode of manufacturing chlorine. Afterwards,
the cock No. 1 being opened, No. 8 is closed, afterwards No. 7; then the evo-
ution of the chlorine in the state of gas commencing the operation of bleaching.

page_text: After chlorine gas
has been evolved for about a quarter of an hour, in a cold
state, I commence gradually to warm the retort, in augmenting the caloric so as
to reach sixty or seventy degrees Centigrade, according to the activity which is
observed, so as to terminate the discharge in two hours, if the quantity of
ingredients is given for acting upon one chamber F at one time, and in about
four hours if the quantity of ingredients is intended to operate upon several
boxes successively. The water tubes Z ought to attain the required clevation
from the beginning of the flow of gas, and should be maintained during the
operation of bleaching in the box, except a slight falling towards the end,
otherwise there may be a prejudicial action by reason of the atmospheric
air. But if the pressure appears too strong, a light emission is made of air
from the box by means of the small opening O, which is made in the discharge
pipe. In the case where the excess of pressure arises from a too great activity
in the discharge of gas, it will be preferable, instead of an emission at O, to
open for a moment the cock No. 8, and diminish or suppress for several
minutes the action of the heat.
The bleaching can be observed in its progress by means of a small window
in a side of the box, and by means of that made in the cover the operator can
be sure that the gas has penetrated to the top, and that the bleaching is
finished, then the cock No. 1, and those 4 and 5, being closed, the discharge
cock No. 6 is to be opened. Then the cocks Nos. 2 and 3 opened, and
during half an hour the chlorine is to be driven from the box by means
of the blowing machine, which is worked gently in the first instance, and
afterwards with more activity. Afterwards I introduce into the vessel F,
through the vase L, by means of the air, volatile alkali or the vapor of
sulphuric ether, or any other matter suitable to destroy the effect of any
remaining chlorine and hydrochloric acid that may be in the cotton. The
ventilating process is then again proceeded with, with air only, to clean the
cotton as much as possible; it may then be withdrawn from the box.
To accomplish more quickly and entirely the discharge of all gaseous
matters, the cotton, bleached and cleaned, instead of being reventilated as before
described, it may be submitted to the action of the machine known as the
hydro extractor.
In witness whereof, I, the said Pierre Isidor David, have hereunto set
my hand and seal, this Twenty-eighth day of August, One thousand
eight hundred and forty-nine.
P. I. (Ls.) DAVID.

page_text: AND BE IT REMEMBERED, that on the Twenty-eighth day of August, in
the year of our Lord 1849, the aforesaid Pierre Isidor David came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.