IMPROVEMENTS IN THE PREPARATION AND MANUFACTURE OF WARIOUS MATERIALS TO BE USED IN THE PROCESSES. OF DYEING, PRINTING, AND COLOURING
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WATSON, the younger, of Chapel Allerton, in the Parish of Leeds, in the
County of York, Manufacturing Chemist, 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 Fourth day of June, in the thirteenth year of Her reign,
did, for Herself, Her beirs and successors, give and grant unto me, the said
William Watson, Her especial license, full power, sole privilege and authority,
that I, the said William Watson, my exors, admors, and assigns, and such
others as I, the said William Watson, my exors, adñiors, 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 mentioned, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, my Invention of "IMPROVEMENTS IN THE PREPARATION AND
MANUFACTURE OF WARIOUS MATERIALS TO BE USED IN THE PROCESSES. OF DYEING,
PRINTING, AND COLOURING;" in which said Letters Patent is contained a proviso,
abliging me, the said William Watson, by an instrument in waiting under my
hand and seal, particularly to describe and ascertain the nature of my said
Invention, and in what manner the same is to be. performed, and to cause the
same to be enrolled in Her 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Watson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly
described and ascertained in and by the following description thereof, reference
being had to the Drawing hereunto annexed, and to the letters and figures
marked thereon (that is to say) :-
My improvements consist in the preparation and manufacture of various
solid compounds of indigo, or of preparations of indigo, with various alkalies
or alkaline earths (that is to say), potash, soda, ammonia, barytes, strontia,
lime, and magnesia, or with various salts of such alkalies or alkaline earths, so
that such products may be economically produced in a dry state, and rendered
more conveniently applicable for the dyeing, printing, and colouring of various
matters or fabrics; and I effect such improvements by adding to or mixing with
á solution or preparation of indigo, in concentrated sulphuric acid, one or more
of the above-mentioned alkalies or alkaline earths or salts, so that the com-
pound resulting from such mixture may be a solid product. I believe that
nearly all the salts of potash, soda, ammonia, barytes, strontia, lime, and
magnesia, which are capable of being decomposed by or forming compounds
with sulphuric acid, may be employed in the manufacture of such preparations
of indigo; but as the compounds resulting from the employment of some of
these materials would be too expensive or inconvenient for general use, I
prefer to use the chloride of sodium or common salt, the carbonate or sub-
carbonate of soda, of potash, or of magnesia, or the sulphate of potash, and the
process as well as the apparatus which I have found it convenient to use in the
preparation and manufacture of such compounds is herein-after particularly
described.
In the preparation of such mixtures and compounds of indigo and salts as
are herein mentioned, I have found it convenient to use an apparatus similar
to that shewn in the accompanying Drawing, which represents a vertical
section thereof. A, A, is a cylinder of cast iron, of the diameter of three feet,
or thereabouts, within which is fitted in any convenient and suitable manner.a
cylinder of copper B, B, so that the space between the cylinders A, A, and
B, B, shall be steam-tight, and connected by means of the pipe C with a boiler
supplying steam at the pressure of about twenty pounds per square inch; c is
a smaller pipe, for carrying away any condensed water. Within the internal
cylinder or vessel is placed an agitator D, D, having two or any convenient
number of arms or blades, the shaft of which works air-tight through a stuffing
box E, and passing through the top or cover of the cylinder, is by suitable
gearing made to revolve at the rate of about eighty revolutions per minute.

page_text: F is a small trap or door, covering a corresponding aperture in the cylinder cover,
made readily removeable for the purpose of introdicing solid matters therein,
and capable of being made air-tight by suitable luting; G is another trap or
door at the bottom of the cylinder, for the purpose of emptying the contents of
the inner cylinder or vessel; II is a pipe or tube for carrying away any gas
or vapour. which may arise during the process, and may, if required, be con-
nected with any suitable apparatus for condensing such gas or vapour, and
applying it to any useful purpose; I is a curved tube, for the purpose of
introducing the solution of indigo.
I make a solution of indigo in sulphuric acid by adding about six parts, by
weight, of concentrated sulphuric acid, the strongest being the best, to one part
of the indigo of commerce, thus making the solution which is commonly called
chymic. I shall, in this my Specification, refer to such solution of indigo of
commerce as solution No. 1; but when I wish to make a compound of
superior quality, for dyeing the best and brightest colours, in lieu of using the
indigo of commerce, I refine or purify the indigo, and I especially advise the
use of indigo which has been refined or purified by solution with protosulphate
of iron and lime, and afterwards precipitated and dried in the manner which is
now well known and understood, and which indigo is called refined indigo;
and I add about ten parts, by weight, of concentrated sulphuric acid to one
part of such refined indigo. I shall refer to the solution of refined indigo as
solution No. 2.
I will now describe the way in which I mix the solutions of indigo with the
alkalies or salts, and as this operation is very similar with all the compounds I
make use of, I will describe the process of mixing the solution of indigo with
common salt. The salt is, in the first instance, to be carefully pulverized, and
is then introduced by the trap or door into the mixing apparatus, herein-before
described, which is kept heated by the admission of steam between the inner
and outer cylinder; the trap or door is luted so as to be air-tight, the agitator
is then put into motion, and one of the solutions of indigo is poured slowly
through the tube I. Hydrochloric acid gas is evolved by the action of the
sulphuric acid on the salt, and is conveyed away by the pipe H while the
operation is continued, until the intended quantity of solution of indigo has
been added and the evolution of gas has nearly ceased, when the compound
will be found to be dry, and may then be allowed to fall through the trap or
door G into any receptacle placed below. I will here remark, that I prefer to
make the other mixtures or compounds hercin described in a similar manner;
but that I do not find the application of heat or of any special apparatus so
essential with regard to other salts as when chlorides are used; in fact, the

page_text: ingredients might be mixed in a mortar, or in any similar or convenient.
manner.
I do not find it essential to use any precise proportions of the solutions of
indigo and of the respective salts; I would merely remark, that only sufficient
of the salt must be used to produce a compound which is sensibly or apparently
dry, and in which the acid may be neutralized if the compound be required to
be neutral, or so that merely such a quantity of sulphuric acid may remain in
the compound in excess as may be found advisable when an acid compound
is required; and as the salts contained in some of the compounds, the results
of the processes herein described, combine with water as water of crystalliza-
tion, I find it advisable in some cases to add to the compound so much water
that the resulting compound may contain à due equivalent of water of
crystallization; for instance, when soda or magnesia, or the carbonates of soda
or magnesia, are employed for making such compounds as herein mentioned;
the ingredients are more readily combined and a compound formed which is
less liable to change by exposure to the air, if for every ten parts by weight of
solution of indigo about six parts of water be added to such compounds when
being mixed, and I prefer to add the water towards the completion of the
process of mixing; moreover, as some of the salts which are formed by
the combination of the alkalies or alkaline earths, herein named, with sulphuric
acid do not readily absorb water as water of crystallization, I think it advisable
to add a proportion of such a salt in an anhydrous condition as will absorb any
uncombined water which may exist in the compound; for instance, when
ammonia, barytes, or strontia are used for making these compounds, I add to
the compound a suitable quantity of the dry sulphate of soda, which salt
I recommend as the best and cheapest salt for this purpose; I would, however,
observe, that other salts in an anhydrous condition, such as dry sulphate of
magnesia or the calcined sulphate of alumina and potash, will answer the same
purpose, and therefore may under some circumstances be advantageously
employed; and I will also remark, that in various applications of the compounds
produced for the purposes of dyeing, printing, and colouring, such compounds
may be required to be acid, alkaline, or neutral; and in like manner, the pre-
parations made with the solution No. 1 are sufficient for many purposes, and
are cheaper than those made with the solution No. 2, whilst; for the production
of bright colours, a preparation is made with the solution No. 2, which is
superior to that made with the solution No. 1, and in like manner, various
alkalies or alkaline earths or salts of these may be found requisite or přeferable;
and I therefore do not confine myself to the use of any one salt or pure salt
in making such compounds, for I have found it desirable to add to some of the

page_text: fore-mentioned compounds another salt or alkali, for the purpose of more
adily neutralizing any excess of acid; for instance, I have found it advan-
geous after making the herein-before described compounds of either of the
lutions of indigo and common salt, to add such a quantity of carbonate of
da, of carbonate of potash, or of carbonate of magnesia, that the compound
all, on trial, be found neutral. And although, as I have before mentioned,
do not consider it essential- to use any precise: proportions of ingredients,
et that the nature of my Invention may be more clearly understood, I will
ate that I consider the proportions of the materials stated in the following
rmula to be such as may be most advantageously used, such proportions
ing estimated by weight; and I would here remark, that I estimate the
rbonate of potash of commerce to contain fifty per cent. of real potash,
e carbonate of soda of commerce to contain fifty per cent. of real soda,
ad the carbonate of magnesia of commerce to contain forty per cent. of real
agnesia :--
No. 1. One hundred parts of either of the herein-before mentioned solutions
of indigo and two hundred parts of common salt or chloride of sodium..
No. 2. One hundred parts of either of the solutions of indigo, two hundred
parts of common salt; and twenty parts of carbonate of magnesia; (and
I will here explain that the carbonate of magnesia is to be added. after
the solution and common salt have been well mixed, and is for the
purpose of neutralizing any free acid.).
No. 3. One hundred parts of either of the solutions of indigo and two-
hundred and thirty parts of sulphate of potash.
No. 4. One hundred parts of either of the solutions of indigo and ninety
parts of caustic potash for a neutral compound..
No. 5. One hundred parts of either of the solutions of indigo and forty-five
"
parts of caustic potash for an acid compound.
No. 6. One hundred parts of either of the solutions of indigo, sixty parts
of caustic soda, and sixty parts of water.
No. 7. One hundred parts of either of the solutions of indigo and thirty-six.
parts of caustic magnesia.
No. 8. One hundred parts of either of the solutions of indigo and: eighty-
.. six parts of the carbonate of potash of commerce for an acid compound.
No. 9. One Irundred parts of either. of the solutions of indigo and one-
hundred and seventy-five parts of the carbonate of potash of commerce
for a neutral compound.
No. 10. One hundred parts of either of the solutions of indigo, one hundred

page_text: and fifteen parts of carbonate of soda of commerce, and sixty parts, of
water.
No. 11.. One hundred parts of either of the solutions of indigo, eighty-two
parts of carbonate of magnesia of commerce, and sixty parts of water.
No.. 12. One hundred parts of either of the solutions of indigo, two hundred
parts of carbonate of baryta, or one hundred and fifty parts of carbonate of
strontia, or ninety parts of carbonate of ammonia, and after the solutions
of indigo have been mixed with such salts, respectively, fifty parts of dry
sulphate of soda; (and I will here remark that the sulphate of soda is
added for the purpose of absorbing any uncombined water.)
I am well aware that manufacturers of preparations of indigo have been
accustomed to precipitate indigo from a solution in sulphuric acid by the addi-
tion of, common salt or other salts, such solution of indigo in sulphuric acid
having been considerably diluted with water, (that is to say,) diluted with more
than five times the weight of the sulphuric acid, the resulting compounds of such
a process being in a state of paste; I therefore wish it to be well understood
that I. do not claim to manufacture, under. the herein-before recited Letters
Patent, any compound of indigo with the salts or substances herein mentioned,
by precipitating indigo from a. diluted solution in sulphuric acid; but what
I claim is,
Firstly, the adding or mixing a solution of indigo in sulphuric acid. to or
with common salt, in manner herein-before described.
Secondly, the adding or mixing a solution of indigo in sulphuric acid to or
with sulphate of potash.
Thirdly, the adding or mixing a solution of indigo in sulphuric acid to or
with caustic potash, caustic soda, or caustic magnesia.
Fourthly, the adding or mixing a solution of indigo in sulphuric acid to or
with the carbonate of potash, carbonate of soda, or carbonate of magnesia.
And, lastly, I claim the manufacture of solid compounds or preparations of
indigo by the admixture of any suitable alkali or alkaline earth, or the salt
of any alkali or alkaline earth, with a solution of indigo in sulphuric acid, so as
to form dry or solid compounds of the nature berein-before set forth.
In witness whereof, I, the said William Watson, the younger, have
hereunto set my hand and seal, the Fourth day of December, in
the year of our Lord One thousand eight hundred and fiſty.
WILLIAM (L.S.) WATSON, JR.

page_text: AND BE IT REMEMBERED, that on the Fourth day of December, in
the year of our Lord 1850, the aforesaid William Watson, the younger, 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.
Enrolled the Fourth day of December, in the year of our Lord One
thousand eight hundred and fifty.