Ax IMPROVED PROCESS FOR DYEING WOOL
Year: 1868

page_text: LETTERS PATENT to Jules Maistre, of Villeneuvette, Departement
de l'Herault, France, Manufacturer, for the Invention of "Ax
IMPROVED PROCESS FOR DYEING WOOL."
Sealed the 28th October 1868, and dated the 2nd May 1868.
PROVISIONAL SPECIFICATION left by the said Jules Maistre at the
Office of the Commissioners of Patents, with his Petition, on the
2nd May 1868.
"
I, JULES MAISTRE, of Villeneuvette, Departement de l'Herault,
France, Manufacturer, do hereby declare the nature of the said Invention
for "AN IMPROVED PROCESS FOR DYEING WOOL," to be as follows:-
My Invention has for its object a process for dyeing wool in large
quantities in any shade of blue by indigo without the use of dyers' woad
vats with potass.
The wool in its greasy state is divided into pieces either by hand or
by mechanical appliances. The indigo is placed to digest with pure
or slightly acidulated water (water acidulated with acetic acid, for
example), some hours afterwards the indigo is crushed until it is

page_text: reduced to a very fine paste; carbonate of soda or any other soluble
alkali, preferably carbonate of potass, is dissolved in water and the
solution serves to diffuse and hold in suspension the indigo previously
reduced to paste. When the mass is well mixed it is warmed by means
of a naked fire or a bain marie (water bath), or by an external steam
coil or jacket, and when the temperature has reached 95 to 120 degrees
Fahrenheit the wool in its greasy state as prepared above is thrown into
or drawn through the solution, care being taken to well mix the whole.
After some hours the liquor is run out from the vessel, which may be
of wood, stone, cement, metal, or other suitable material, and when the
liquid has run off the wool is removed by any manual or mechanical
means. It is then passed between two heavy cylinders to well squeeze
it, or it is submitted to the action of a hydro-extractor or a press. When
a press is used the liquid is run off from the vessel, or in order to shorten
the operation the wool may be pressed in the vessel itself. When the
wool is sufficiently freed from liquid it is removed and spread upon the
ground in order to expose it to the air and facilitate the oxydation of
the indigo which has begun to pass to the soluble state. After some
minutes the solution is returned to the vessel, and after it has been well
stirred the wool is again thrown into it. Twelve hours afterwards the
operation is recommenced in the same manner, and it is repeated two or
three times daily until the wool has attained the desired shade. There
only remains now to wash the wool by the ordinary processes. If the
vessels are placed in a cold chamber it will be necessary to heat the
solution each time it has been removed from the vessel, but this will
be needless if the operations take place in an apartment heated to from
about 95 to 112 degrees Fahrenheit. The proportions of carbonate of
potas, soda, or other alkali, as well as of the indigo, vary according
to the condition of the wool and the depth of blue color desired.
The following proportions have been found to answer well, but I do
not limit myself thereto, viz. :-For about 2 cwt. of greasy wool, yielding
about 22 per cent., I employ about 4½ lbs. of indigo, 8½ lbs. of carbonate
of potass, 60 gallons of water, and 3 quarts of vinegar; with these pro-
portions the digestion of the indigo in acidulated water and the bath
of carbonate of potass are prepared. This process not requiring the use
of lime is more healthy for the dyers. It does not dye the straw or
other vegetable substances mixed with the wool so much as the ordinary
process, so that the scouring which has formerly been necessary to render

page_text: these substances visible may be dispensed with. Another advantage is
that the residuum remaining from the wool may be utilized for agri-
culture. The fermentation which has taken place has destroyed the
fatty matter and put the potass at liberty, so that it may be added at
once to water used for irrigating fields.
The same process of dyeing in blue wool in the greasy state can also
be advantageously effected by substituting for the indigo a color
obtained from aniline or from any other product derived from the
distillation of coal. The wool thus dyed does not lose its color by
washing or fulling.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Jules Maistre in the Great Seal Patent Office on
the 31st October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JULES
MAISTRE, of Villeneuvette, Departement de l'Herault, France, Mani -
facturer, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of May, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Jules Maistre, Her special licence
that I, the said Jules Maistre, my executors, administrators, and assigns,
or such others as I, the said Jules Maistre, my executors, adminis-
trators, 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 PROCESS: FOR.
DYEING WOOL," upon the condition (amongst others) that I, the said Jules:
Maistre, 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.

page_text: NOW KNOW YE, that I, the said Jules Maistre, 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 thereof, that is to say :-
My Invention has for its object a process for dyeing wool in large
quantities any shade of blue by vegetable indigo or mineral indigo
arising from the distillation of tars without the use of dyers' woad vats
with potass.
The wool in its greasy state, that is to say, containing the "suint" or
potash compound excreted from the skin with the sweat, is divided into
pieces either by hand or by mechanical appliances. The indigo is placed
to digest with pure or slightly acidulated water (water acidulated with
acetic acid, for example), some hours afterwards the indigo is crushed
until it is reduced to a very fine paste. Carbonate of soda or any other
soluble alkali, preferably carbonate of potass, is dissolved in water, and
the solution serves to diffuse and hold in suspension the indigo previously
reduced to paste as above stated. When the mass is well mixed it is
heated by means of a naked fire or a bain marie (water bath), or by an
external steam coil or jacket, and when the temperature has reached 95
to 120 degrees Fahrenheit the wool in its greasy state or state of suint,
as prepared above, is thrown into or drawn through the solution, care
being taken to well mix the whole. After some hours the liquor is run
out from the vessel, which may be of wood, stone, cement, metal, or
other suitable material, and when the liquor has run off the wool is
removed by any manual or mechanical means. It is then passed between
two heavy cylinders to well squeeze it, or it is submitted to the action of
a hydro-extractor or a press. When a press is used the liquor is run off
from the vessel, or in order to shorten the operation the wool may be
pressed in the vessel itself. When the wool is sufficiently freed from
liquor it is removed and spread upon the ground in order to expose it to
the air and facilitate the oxydation of the indigo, which has begun to
pass to the soluble state. After some minutes the solution is returned
to the vessel, and after it has been well stirred the wool is again thrown
into it. Twelve hours afterwards the operation is recommenced in the
same manner, and it is repeated two or three times daily until the wool
has attained the desired shade. There only remains now to wash the
wool by the ordinary processes. If the vessels are placed in a cold
chamber it will be necessary to heat the solution each time it has been

page_text: removed from the vessel, but this will be unnecessary if the operations
take place in an apartment heated to from about 95 to 112 degrees
Fahrenheit. The proportions of carbonate of potass, soda, or other alkali,
as well as of the indigo vary according to the condition of the wool and
the depth of blue color desired.
a
The following proportions have been found to answer well, but I do
not limit myself thereto, viz. :-For about 2 cwt. of greasy wool, or wool
in the state of suint, yielding about 22 per cent., I employ about 4 lbs.
of indigo, 8 lbs. of carbonate of potass, 60 gallons of water, and 3
quarts of vinegar; with these proportions the digestion of the indigo in
acidulated water and the bath of carbonate of potass are prepared.
This process not requiring the use of lime is more healthy for the dyers.
The mode of working above explained may be slightly modified
without altering the characteristic features of the process. The chief
difference of this second mode is the use of several quarts of urine,
which is employed concurrently with a little lime. The indigo boiled
with carbonate of soda or of potass having been thrown into a copper or
vessel containing a bath of very concentrated suint or greasy matter, I
stir or agitate to bring to the surface the substances which tend to
become deposited, and I heat the bath to a temperature of from 105° to
120°. It is into this vessel that I pour a mixture of carbonate of soda
or of potass, of quicklime in powder and urine, which are first mixed in
suitable proportions in a kettle. Having afterwards skimmed and stirred
the bath in the copper I place in it the wool in the greasy state or state
of suint, and I pursue the dyeing treatment under nearly the same
conditions as before described. However woad may be added to the
bath to facilitate the operation and economize the indigo. The fermen-
tation provoked by the woad combined with that of the suint facilitates
the dissolution and the fixing of the coloring matter. When dyeing of
wool in the greasy state has proceeded several days, and the bath is
much charged wool which has previously been washed may be dyed.
Whichever of the two modes above described is employed the color
obtained by this process is fine and brilliant without altering the nature
of the wool employed. It does not dye the straw or other vegetable
substances mixed with the wool so much as the ordinary process, so that
the scouring which has formerly been necessary to render these sub-
stances visible may be dispensed with. Another advantage of the present
process is that the residuum or "suint" remaining from the wool may be

page_text: utilized for agriculture. The fermentation which has taken place has
destroyed the fatty matter and put the potass at liberty, so that it may
be added at once to water used for irrigating fields.
The same process applies not only to vegetable and mineral indigo, but
also to woad and other vegetable or mineral matters which will give a
blue colour.
And having now described the nature of the said Invention, and in
what manner the same is to be performed, I declare that I claim dyeing
wool in the greasy state or state of suint, substantially by the means and
in the manner herein-before described.
In witness whereof, I, the said Jules Maistre, have hereunto set
my hand and seal, this Tenth day of October, One thousand eight
hundred and sixty-eight.
Witness,
CH. ARMENGAUD,
Civil Engineer,
Boulev. de Strasbourg, 23,
à Paris.
JULES MAISTRE. (L.S.)