IMPROVEMENTS IN DYEING AND PRINTING SILK, WOOL, AND OTHER ANIMAL FIBRES
Year: 1853

page_text: LETTERS PATENT to François Francillon, of Puteaux, in the
Empire of France, for the Invention of "IMPROVEMENTS IN
DYEING AND PRINTING SILK, WOOL, AND OTHER ANIMAL FIBRES."
Sealed the 29th July 1853, and dated the 28th May 1853.
PROVISIONAL SPECIFICATION left by the said François Francillon
at the Office of the Commissioners of Patents, with his Petition,
on the 28th May 1853.
I, FRANÇOIS FRANCILLON, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN DYEING AND PRINTING SILK, WOOL, AND
OTHER ANIMAL FIBRES," to be as follows:-
This Invention relates to a method of fixing upon silk, wool, and
other animal fibres, such as hair, feathers, skins, &c., the
green oxide of
chrome, called by French chymists sesqui-oxide of chrome, or the
chromic oxide of Berzelius. This oxide may either be applied and
fixed alone, or in order to produce various shades and colours the

page_text: oxide may be employed in combination with various substances, such
as certain acids or oxides, or with coloring or astringent matters.
This process is based either upon the oxidation of chromous oxide,
which may be effected upon the substances either in the fibrous state
or after having been manufactured into the fabrics to be dyed or
printed, or it may be effected by the reduction of chromic acid and
its conversion into chromic oxide.
The Invention which is desired to be protected is the fixing by
chemical means chromic oxide upon silk, wool, and other animal
products.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said François Francillon in the Great Seal Patent
Oflice, on the 26th November 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
FRANÇOIS FRANCILLON, of Puteaux, in the Empire of France, send
grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of May, in the
year of our Lord One thousand eight hundred and fifty-three, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said François Francillon, Her special
licence that I, the said François Francillon, my executors, administra-
tors, and assigns, or such others as I, the said François Francillon, 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 "IM-
PROVEMENTS IN DYEING AND PRINTING SILK, WOOL, AND OTHER ANIMAL
FIBRES," upon the condition (amongst others) that I, the said François
Francillon, 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

page_text: be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters. Patent.
NOW KNOW YE, that I, the said François Francillon, 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 Invention of improvements in dyeing and printing silk, wool,
and other animal fibres relates to a method of fixing upon silk, wool,
and other animal fibres, such as hair, feathers, or skins, the given oxide
of chrome, called by French chymists sesqui-oxide of chrome, or the
chromic oxide of Berzelius. This oxide may either be applied and fixed
alone, or in order to produce various shades and colors the oxide may
also be employed in combination with various substances, such as cer-
tain acids or oxides, or with coloring or astringent matters.
This object of the Invention may be effected cither by the oxidation
of chromous oxide, which may be effected upon the substances either
in the fibrous state or after having been manufactured into the fabrics
to be dyed or printed, or the same effect may be produced by the
reduction of chromic acid and its conversion into chromic oxide.
.
The fixing operation is carried on in the following manner :-A cold
saturated solution of bichromate of potash. is laid evenly either upon the
whole fabric or upon any part which it is desired to have colored, dyed,
or stained; and I would here observe, that there are some kinds of
fibres which are better impregnated with impure chromic acid, or even
with bichromate of the chloride (salt of peligot), than with a perfectly
pure salt. This operation is performed at the ordinary temperature, or
at a temperature of thirty degrees, forty degrees, or fifty degrees of the
centigrade thermometer, or even a higher temperature may be em-
ployed, according to the nature of the fibre to be operated upon.
The fibre thus impregnated with chromate or chromic acid is left in
repose for some hours protected from the solar rays; the operation of
reducing the chromic acid is then proceeded with, in order to deprive
the acid of a moiety of its oxygen and convert it into chromic oxide.
. It is well known that many agents are capable of effecting the
reduction of chromic acid, either in a free state or in the form of

page_text: chromate, and of converting it into green oxide. Amongst these may
be particularly mentioned chloride of tin, the hydro-acids, phosphorous
acid, several oxy-acids of sulphur, either free or in the form of a salt,
but more especially sulphurous acid. This latter has been preferred,
inasmuch as, besides presenting the advantage of economy, it possesses
furthermore that of only requiring for its action the apparatus and
processes employed for bleaching woollen and silken fabrics by means
of sulphur.
When the fibres or fabrics to be dyed have been impregnated with
chromic acid they are to be exposed in a damp state to the action of
sulphurous acid, either in a gaseous form or in solution. The sulphu-
rous acid instantly effects the reduction of the chromic acid, and the
fibres pass from a brownish yellow color to either a greyish green or a
decided green, according to whether the chromate has been employed
alone or with the addition of arsenious or arsenic acid. The fabric or
material now only requires to be washed, and the color is fixed.
The tint obtained by means of the red chromate is upon wool a
grey green, and a sca green upon silk, but much less intense; by
adding to the chromate arsenical preparations a great variety of shades
of green may be produced.
As the chromic acid acts as a mordant as energetically as alumina
and oxide of iron, yarns or fabrics upon which the chromic acid has
been previously fixed may be dyed in baths of madder, cochineal, and
other matters, and by this means several fancy shades may be pro-
duced; but in the same manner as when mordants of alumina and
iron are employed together in order to produce complex shades, so
the chromic oxide, mixed with the preceding mordants, serves to pro-
duce still more varying tints, which cannot easily be imitated by other
processes.
The coloring or astringent matter may, when they allow of it, be
deposited and fixed at the same time as the chromate, and the sulphu-
rous acid be allowed to act afterwards.
In conclusion, I desire it to be understood, that I claim the applica-
tion to the dyeing and printing of fibres, yarns, threads, silken and
woollen fabrics, and other animal fibres or tissues (such as hair, feathers,

page_text: or skins), of the color produced by the fixing thereon of the
fixing thereon of the green oxide
of chrome (the sesqui-oxide of chrome of the French chymists and the
chromic oxide of Berzelius.) This oxide I either apply and fix alone,
or in order to produce various tints I combine it (either at the time
of applying it to the material or afterwards) either with certain acids,
such as phosphoric, phosphorous, arsenic, or arsenious acid, or with
certain oxides, such as those of iron, lead, copper, or other metal, or
with coloring matters which require the assistance of an oxide in
order to combine with the fibre, and which find in the chromic oxide a
mordant, and, lastly, with that no less numerous class of astringent
matters by means of which so many fast colors are produced. I do
not, therefore, intend to confine myself to the process above described;
but what I consider to be new, and desire to claim as of iny Inven-
tion in the above-described process, is, dyeing and printing animal
fibres, such as wool, silk, hair, feathers, or skins, by means of chromic
acid or its combinations, which may be reduced and converted into a
chromic oxide, and fixed by any convenient chemical means, as above
described.
In witness whereof, I, the said François Francillon, have here-
unto set my hand and seal, this Eighteenth day of November,
in the year of our Lord One thousand eight hundred and fifty-
three.
Witness,
5
FRANÇOIS FRANCILLON. (L.S.)
JOHN SAMUEL BERENS.