THE MANUFACTURE AND APPLICATION TO FIBRES AND FABRICS, OF A NEW BLUE COLOUR AND COMPOUNDS OF THE SAME WITH OTHER COLOURS
Year: 1860

page_text: LETTERS PATENT to Charles Cowper, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, for the
Invention of "THE MANUFACTURE AND APPLICATION TO FIBRES AND FABRICS,
OF A NEW BLUE COLOUR AND COMPOUNDS OF THE SAME WITH OTHER COLOURS."
-A communication from abroad by Cyprien Mario Tessió du Motay,
residing at Paris in France.
Sealed the 17th July 1860, and dated the 16th May 1860.
PROVISIONAL SPECIFICATION left by the said Charles Cowper at the
Office of the Commissioners of Patents, with his Petition, on the 16th
May 1860.
I, CHARLES COWPER, of No. 20, Southampton Buildings, Chancery Lane,
in the County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "THE MANUFACTURE AND APPLICATION TO FIBRES AND
FABRICS OF A NEW BLUE COLOUR AND COMPOUNDS OF THE SAME WITH OTHER
COLOURS," to be as follows:-
Soluble prussian blue and carmine of indigo when mixed together in
equivalent or other suitable proportions dissolve each other, combine and
form a new blue of definite composition, which has the characteristic property
of producing upon animal or vegetable fibres or fabrics, either alone or with
the aid of mordants, a clear colour, which does not vary in artificial or solar
-light and has not hitherto been known or used. In the reaction. of the
carmine. of indigo on the soluble prussian blue, the violet blue of the
.indigo being compensated or corrected by the greenish blue of the cyanide of

page_text: iron produces a free clear blue, which appears the same or nearly so by
natural light or by artificial light, and fibres or tissues, dyed in a bath of this
cyano-indigotic blue, may, by the addition of yellow and other tinctorial
substances, be dyed green and olive, and various other tints containing blue,
and will appear of their proper colours, both by solar and artificial light. To
prepare the new blue, a certain quantity of prussiate of potash or ferrocyanide
of potassium is dissolved in water, and a suitable quantity of persulphate of
iron, which has been previously boiled with sulphuric acid and dissolved in
water, is added. A precipitate of prussian blue insoluble in the excess of the
precipitant is thus obtained. This blue is thrown on a filter and allowed
to drain until it is in a pasty state and it is then soluble in pure water. Other
persalts of iron may be used instead of the persulphate. To this prussian bluo
an equivalent proportion of carmine of indigo is added and the mixture well
stirred and incorporated. The two blues combine and produce the new blue
above mentioned, which is applicable either alone or in conjunction with
yellows and other colours for dyeing and printing animal or vegetable fibres,
fabrics, and tissues...
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Cowper in the Great Seal Patent Office on the
5th November 1860.
TO ALL TO. WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWPER, of No. 20, Southampton Buildings, Chancory Lane, in the County of
Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of May, in the year of our
'Lord One thousand eight hundred and sixty, in the twenty-third-year of: Hor
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Cowper, Her special licence that I, the said Charles Cowper, my
executors, administrators, and assigns, or such others as I, the said Charles
Cowper, 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 "THE MANUFACTURE AND APPLICA-
TION TO FIBRES AND FABRICS OF A NEW BLUE COLOUR AND COMPOUNDS OF THE SAME
WITH OTHER COLOURS," communicated to me from abroad by Cyprien Marie

page_text: Tessié du Motay, residing at Paris, in France, upon the condition (amongst
others) that I, the said Charles Cowper, 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.
:
: NOW KNOW YE, that I, the said Charles Cowper, do hereby declare the
nature of the 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:-
>
a new
Soluble prussian blue and carmine of indigo, when mixed in the proportion
of their chemical equivalents, dissolve each other, and combine to form
blue of definite composition. This blue, the chemical composition of which
constitutes a new discovery, has the characteristic property of producing upon
fibres and fabrics of animal or vegetable origin, either alone or with the aid of
mordants, a clear colour, which does not vary in artificial or solar light and
has not been known or used before the date of the aforesaid Letters Patent.
The carmine of indigo is prepared by dissolving indigo in sulphuric acid,
whereby sulph-indigotic acid is produced. This double acid combines with
alkalies forming sulph-indigotates, which are used in dyeing under the name
of carmine of indigo. The sulph-indigotic acid saturated with an alkaline
base, so as to form a neutral sulph-indigotate of soda or potash, is the carmine
of indigo, which is to be mixed with the soluble prussian blue. In the
reaction of the carmine of indigo upon the soluble prussian blue, the violet
blue of the indigo is compensated or corrected by the greenish blue of the
prussian blue, and thus produces a pure or neutral blue, which appears the same
or very nearly the same by solar as by artificial light. Moreover, fibres and
fabrics may be dyed in a bath of this blue, and by the addition of yellow dyes,
various tints of green may be obtained, which have also the property of
appearing the same by solar as by artificial light..
The following is the process of preparing the new blue.-Five pounds
weight of prussiate of potash are dissolved in fifteen pounds weight of water, and
to this solution is added two and a quarter pounds of persulphate of iron, which
has been previously boiled with one and three quarter pounds of oil of vitriol or
sulphuric acid of commerce and dissolved in eight pounds of water. A pre-
cipitate of prussian blue insoluble in excess of the precipitant is thus produced.
This precipitate is placed on a filter and the solution allowed to 'drain away
from it until it becomes of a pasty consistence, and it is then soluble in purc

page_text: ¡water.
Other persalts of iron in equivalent proportions may be employed
instead of the persulphate. A quantity of the carmine of indigo is well mixed
.with this soluble prussian blue in the proportion of one chemical equivalent of
cach. The two blues combine to form the new blue herein-before mentioned.
This blue may bo used with other colours to produce olive and various other
compounds of blue, and it may, if required, be used with an excess of the
soluble prussian blue, or of the carmine of indigo, so as to vary the tint. This
'new blue being dissolved or mixed with water forms a bath for dyeing, and it
may be employed with gum water or other thickener for printing on fabrics or
yarns. This new blue does not require any special mordants for its appli-
cation. It is more soluble in distilled water than in water containing lime,
and in water heated to from one hundred and four degrees to one hundred and
'twenty-two degrees of Fahrenheit's thermometer than in cold water. It is
precipitated in water at a temperature above one hundred and seventy-six
degrees of Fahrenheit's thermometer. To prevent or retard this precipitation
it is advantageous to employ a solution of oxalic acid or still better of an
alkaline oxalate: For this purpose one or two pounds of oxalic acid, or three
or four pounds of an alkaline oxalate aro dissolved in one hundred pounds of
-water, and from about ten to fifteen pounds of the new blue are added. For
dyeing silk, the temperature of the bath or mixture should be between seventy
'seven and ninety-five degrees of Fahrenheit's thermometer. For dyeing wool,
the temperature should be between one hundred and forty and one hundred
and seventy-six degrees of Fahrenheit's thermometer, but it ought not to ex-
'ceed this last temperature.
.
Having now described the nature of the said Invention, and in what
*manner the same is to be performed I wish it to be understood that what I
claim is,―
•
"
The manufacture and application of the aforesaid compound or new blue to
-dyeing and printing animal and vegetable fibres and fabrics either alone or in
combination with other colours.
:
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Fifth day of November, in the year of our
Lord One thousand eight hundred and sixty.
CHARLES COWPER. (L.S.)