A CERTAIN IMPROVEMENT. OR CERTAIN IMPROVEMENTS- IN DYEING
Year: 1845

page_text: MURDOCH'S SPECIFICATION..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MURDOCH, of Staple Inn, in the County of Middlesex, Mechanical Draughts-
man and Patent Agent, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Tenth day of June, in the eighth year of Her reign, did,
for Herself, Her heirs. and. successors, give and grant unto me, the said
James Murdoch, my exors, .admors, Her especial licence, full power, sole
privilege and authority, that I, the said James Murdoch, my exors, admors,
and assigns, or such others as I, the said James Murdoch, my exors,
admiors,, or assigns, should at any time agree with, and no other, from
time to time and at 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, the Invention of "A CERTAIN
IMPROVEMENT. OR CERTAIN IMPROVEMENTS- IN DYEING," communicated to me by
a certain foreigner residing abroad; in which said Letters Patent is contained a
proviso, that I, the said James Murdoch, shall cause a particular description
of the nature of the said Invention, and-in what manner the same is to be per-
formed, to be inrolled in Her said Majesty's High Court of Chancery within
six calendar month 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 have ascer-
tained and set forth the nature of the said Invention, and the manner in
which it is to be carried into effect, in and by the following description thereof,
that is to say:

page_text: The Invention consists in the employment of certain materials as substitutes
for cream of tartar (bisulphate of potash), and for the compound of cream of
tartar and alum (sulphate of potash and alumine), which are ordinarily
employed as mordants in dyeing.
.
The substitute for cream of tartar is composed of muriate of soda (common
salt), or muriate of potash, combined with nitric acid, and in lieu of alum I
employ sulphate of alumine, which being added to the mixture of muriate of
soda (or of potash) and nitric acid, forms a mordant analogeous to that com-
posed of cream of tartar and potash. The proportions of the materials which
are recommended as preferable, and the manner of combining them, are as
follows:-To one hundred pounds of sea salt add three hundred pounds of
water, and when the salt is completely dissolved add to the solution twenty
pounds of nitric acid; and in the case of the mordant being required to le
analogous to that composed of cream of tartar and alum, one hundred poun:ls
of sulphate of alumine are to be gradually added to the mixture. The water
employed should be cold, and the mixture should be but slightly stirred,
especially whilst the sulphate of alumine is being added thereto, in order to
avoid as much as possible the disengagement of nitric and muriatic acid gas,
which would injure the quality of the mordant. The new mordant may be
used either in the dye bath or in the mordant bath, in the same manner and in
'the same proportions as cream of tartar or cream of tartar and alum. As a
measure of precaution (especially until the use of the mordant as become
familiar), it will be advisable to begin the first piece with cream of tartar or
cream and alum, according to the color of the dye bath, especially for blacks,
crimsons, and violets; indeed, for these colors I would recommend the addition
of one part of cream of tartar to three parts of the new mordant, to prevent
the colors changing, which might otherwise happen by accident.
Having thus described the nature of the Invention, and the manner in which
the same is to be carried into effect, I claim,-
First, the employment as a mordant in dyeing of a compound formed of
nitric acid and muriate of soda or muriate of potash.
Second, the employment of a mordant composed as in the first claim, with
the addition of sulphate of alumine.
In witness whereof, I, the said James Murdoch, have hereunto set my
hand and seal, this Tenth day of December, in the year of our Lord
One thousand eight hundred and forty-five.
JAMES (L.s.) MURDOCH.

page_text: AND BE IT REMEMBERED, that on the Tenth day of December, in the
year of our Lord 1845, the aforesaid .James Murdoch came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, 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..
Enrolled the Tenth day of December, in the year of our Lord One
thousand eight hundred and forty-five.