IMPROVEMENTS IN TREATING ORES TO OBTAIN A NEW METALLIC SUBSTANCE AND ITS SALTS, AND IN THE APPLICATION OF SUCH MATTERS, AND ALSO CERTAIN PRODUCTS OF TUNGSTEN TN DYEING PRINTING, AND PAINTING
Year: 1859

page_text: LETTERS PATENT to Frederick William Emerson, of 110, Fenchurch
Street, in the City of London, for the Invention of "IMPROVEMENTS IN
TREATING ORES TO OBTAIN A NEW METALLIC SUBSTANCE AND ITS SALTS, AND IN
THE APPLICATION OF SUCH MATTERS, AND ALSO CERTAIN PRODUCTS OF TUNGSTEN
TN DYEING PRINTING, AND PAINTING."
Sealed the 27th October 1859, and dated the 2nd May 1859.
PROVISIONAL SPECIFICATION left by the said Frederick William
Emerson at the Office of the Commissioners of Patents, with his
Petition, on the 2nd May 1859.
I, FREDERICK WILLIAM EMERSON, of 110, Fenchurch Street, in the City of
London, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN TREATING ORES TO OBTAIN A NEW METALLIC SUBSTANCE AND ITS SALTS, AND IN
THE APPLICATION OF SUCH MATTERS. AND ALSO CERTAIN PRODUCTS OF TUNGSTEN
IN DYEING, PRINTING, AND PAINTING," to be as follows:-
My Invention consists, firstly, in the separation of a metallic substance,
which I believe to be entirely new,and which I propose to call chrolithineum,
from the so called ores of tungsten, such as wolfram, tungstate of lime, tungstic
oxide, and others; and the manufacture and application of its various salts to
useful purposes in the arts, such as dyeing textile fabrics, painting in
porcelain, and the production of paints and pigments.

page_text: Secondly, in the manufacture and application of the so called blue oxide of
tungsten as a dyeing substance for textile fabrics, and as a paint or pigment.
Thirdly,the production of paratungstate of alkali, meta tungstate of alkali,
isotungstate of alkali, and polytungstate of alkali, which may be used in the
preparation of paints and pigments, and for dyeing textile fabrics and other
useful purposes,and the combination of paratungstic, metatungstic, isotungstic
and polytungstic acids, with any suitable metallic oxide or mixtures of metallic
oxides as a base, such as the oxides of lead, zinc, barytes, lime, and others to
forms paints and pigments. Firstly, I take the ore of tungsten to be treated,
and mix it with any caustic alkali or alkaline salt, or caustic alkaline earth,
or alkaline earthy salt, or any mixtures of the same, such as will decompose
the ore to be treated, and put the mixture into any convenient retort of iron or
fire-clay set in a furnace, and submit the same to heat, and conduct the
resulting vapours into any convenient condensingchamberorvessel; theproduce
so obtained (which I call the salts or oxides of chrolithineum, as the case may
be, in some cases are at once fit for various uses in the arts, as dyeing textile
fabrics, preparation of paints and pigments. In other cases they require to
be first purified by re-crystallisation; or, sometimes,it may be more convenient
as well as economical to obtain the salt of chrolithineum in one form, and
afterwards to convert it into another desired form or combination by any of
the means well known to chemists. The solid matter left in the retort after
the before-mentioned vapors have been driven off may then be used in the
preparation of the various oxides and salts of tungsten.
To produce the chrolithineum in its metallic form, I take the oxide or salt,
produced as aforesaid, or by any other means, and mix the same with charcoal
coal, or coke dust, or oil, or tar, or any other carbonaceous or reducing matter,
and submit the same to a strong heat in a covered crucible placed in an air
blast, reverbatory, or other convenient form of reducing furnace; orIput the salt
or oxide before mentioned into a retort furnace,either with or without mixing
with it any of the before-mentioned reducing matters, and pass over it while
at a strong heat a stream of hydrogen or carburetted hydrogen or common
coal gas; or in some cases it may be found more convenient to reduce it by
means of sodium or potassium.
To produce the blue oxide of tungsten I take a soluble alkaline salt of
tungsten, and having placed it either in a hot or cold solution, metallic
tin, zinc, or other similar reducing or deoxidizing metallic agent, I add
by degrees muriatic, sulphuric, acetic, or other suitable acid. until it
ceases to give any further precipitate. In dealing with quantities it will
generally be necessary to allow the action to continue for some hours,

page_text: until any precipitated tungstic acid is entirely converted into the blue oxide.
When the desired depth of color is attained, the blue oxide may be separated
by subsidence and decantation, or by filtration, and should be quickly and
thoroughlydried,and the supernatant liquorevaporated to the crystallisingpoint
to recover the salt of the deoxidizing metal used, if it be commercially valuable.
When it is designed to apply the blue oxide of tungsten to any use requiring
any considerable stability and permanency, if it has been produced in the
manner just described, I prefer afterwards to pass it through the same process
as hereafter described for the conversion of tungstic acid into the blue oxide,
and which process, as a general rule, I prefer both for economy and stability
of color. It is as follows:--I take tungstic acid, or any other acid oxide of
tungsten, by whatever means produced, and place the same in any convenient
retort of iron, fire-clay, or other refractory material, which may be fitted up
internally with perforated shelves to receive the tungstic acid, or the retort
may be made to rotate on its axis, or a system of stirrers may be used, or any
ether means that will present a continually fresh surface to the reaction taking
place in the retort. The cover or door of the retort being well luted on; I
raise the furnace to a low red heat, and continue to pass over or through the
tungstic acid a stream of hydrogen, carburetted hydrogen, or common coal
gas, or carbonic oxide, until the tungstic acid is thoroughly converted into the
blue oxide, which may be ascertained by drawing a sample through a small
trap hole in the retort. I then allow the furnace to get quite or nearly quite
cold before drawing the charge, otherwise it should be withdrawn very expe_
ditiously into any convenient air-tight receiver, as it is very apt to degenerate
in color if exposed to atmospheric influences in a heated state.
To prepare paratungstate of alkali, I thoroughly mix the ore of tungston
to be treated with its equivalent of caustic or carbonated alkali,or alkaline salt,
that will decompose the ore of tungsten, or mixtures of the same, and put the
same into a retort, or reverbatory, or other convenient form of furnace, and
continue it at a bright red heat, until the ore of tungsten is decomposed, or
nearly so, and the combination of the tungestic acid and the alkali effected. If
sulphate of alkali is used, I mix with it sufficient coal, coke, or charcoal dust,
or other carbonaceous material, to effect the decomposition of the sulphate,
and during the melting of the mixture allow an access of atmospheric air. I
then withdraw the charge from the furnace, and dissolve out with either hot
or cold water the soluble tangstate of alkali; and to the clear solution, by pre-
ference kept in a boiling state, 1 add very cautiously by degrees tangstic acid
(by whatever means obtained by preference tangstic acid recently precipitated
from tungstate of alkali by hydrochloric acid, until the solution ceases to give

page_text: a precipitate on the addition of a little dilute nitric acid, which will be the
indication of its conversion into paratungstate of alkali; it may then be used
in the preparation of paints and pigments, or as a mordant in dying textile
fabrics, or otherwise, or may be first evaporated and crystallized; or Iproduce
tungstate of soda by boiling the ore of tungsten with its equivolent of any
caustic alkali, and afterwards convert it into paratungstate of alkali by the
addition of recently precipitated tungstic acid, as already described.
To prepare
the metatungstate of alkali, I boil for several hours a solution
of paratungstate of alkali, obtained as before described, or any other means,
which, when cool, I filter or decant off the clear solution, and evaporate.it
to a syrupy consistency, and then set aside to crystallise in any convenient
vessel. The metatungstate of alkali so produced, or by any other means,
may then be used in the preparation of paints and pigments, or as a mordant
in dying textile fabrics.
To prepare the isotungstate of alkali, I boil the metutungstate of alkali
obtained as last described, or by any other means, with an excess of caustic
alkali, and evaporate it to dryness, and heat it at a low red heat in any con-
venient furnace, and afterwards dissolve out the isotungstate of alkali with
either hot or cold water, and evaporate it to the crystallizing point, and set it
aside in any covenient vessel to crystallize. It is then ready to be used in the
preparation of paints and pigments, or as a mordant in dyeing textile fabrics.
To prepare the polytungstate of alkali, I take tungstic acid, obtained by
the action of a strong mineral acid, or a mixture of sulphuric acid and salt,
on finely powdered wolfram, and digest the tungstic acid so obtained in a
solution of caustic alkali, which, when saturated, I evaporate very slowly,
separating first paratungstate of alkali, and afterwards isotungstate of alkali;
the mother liquor; I then evaporate till it assumes a brownish color; in this
state I leave it in a state of quietude for some time, until it separates into
two distinct layers or strata, one of which is brown and syrupy; to this I
add boiling hydrochloric acid, which throws down polytungstic acid, which
I separate by filtration or decantation, and afterwards digest in caustic alkali,
and evaporate the solution to the crystallizing point, and set it aside in any
convenient vessel to crystallize. It is then ready to be used in the prepar-
ation of paints and pigments as a dyer's mordaunt, or other useful purposes.
I will now describe some of the useful purposes to which the foregoing
products from the ores of tungsten may be applied in the art of dyeing various
colors in textile fabrics and in the production of paints and pigments. The
infinite variety of combinations of which they are capable, with other metallic
oxides and vegetable and animal tinctorial substances, for the productions of

page_text: paints and pigments of various shades and colors, and in dyeing textile fabrics,
is so great, that a few examples will suffice to give the key by which the
practical chemist and dyer will be enabled to operate.
To produce paints and pigments from the before-described so-called salts of
chrolithineum, I take the solution of the said salt, either alone or mixed with
the salt of any other metallic oxide that will not cause a precipitate, and add
to it the salt of any other metallic substance that will cause a precipitate
with or without the addition of any vegetable or animal tinctorial matter, as
madder, cochineal, or others; in this manner an almost infinite variety of
changes may be made, so as to produce variety of colors and shades. For an
example, I take a solution of a salt of chrolithineum, and pour into it a
solution of bichromate of potash; the precipitate, which is a brilliant and
very permanent yellow, after being well washed and dried, is ready to be
ground in oil, turpentine, varnish, or other suitable vehicle, and used as a
paint or pigment, or for painting in porcelain, &c. In dyeing the same into
any textile fabric, I boil the substance to be operated upon, either in the
skein or in the piece, in a solution of the salt of chrolitbineum, and after
drying it immerse it in a hot or cold solution, or boil it in a solution of
bichromate of potash, and after thoroughly wincing it, and carrying it through
the other aperations well known to dyers, it gives a very fine permanent
yellow, or previously to wincing, it may be boiled in a solution of madder,
which will produce it of a brilliant orange color.
I have already stated the manner in which the blue oxide of tungsten may
be produced, and for use as a paint or pigment it only requires to be mixed
or ground in oil, turpentine, varnish, or other suitable vehicle to be ready
for use.
To dye the blue oxide of tungsten into textile fabrics, I take the
substance to be dyed, either in the skein or in the piece, and boil it in an
alkaline salt of tungsten, and after drying immerse it in dilute muriatic,
sulphuric, acetic, or other suitable acid, in which is placed metallic zinc,
tin, or other deoxodizing metallic agent, and continue the operation, either
with or without heat, until the desired depth of color is obtained, and the
blue oxide thoroughly combined with the fibre of the substance acted on.
It may then be winced and carried through the other operations well
known to practical dyers.
To produce paints and pigments from the before-described paratungstate,
metatungstate, isotungstate, cr polytungstate of alkali, I take the clearsolution
of any of those salts, produced as before described, or by any other means, and
add it to the clear solution of a salt of a metallic or earthy oxide, as acetate
or nitrate or chloride of lead, zinc, barytes, or lime, or mixtures of the same.

page_text: The precipitate, after being thoroughly washed and dried, is ready to be
ground in oil, turpentine, varnish, or other suitable vehicle, and used as a
paint or pigment.
In using the paratungstate, metatungstate, isotungstate, or polytungstate
of alkali for the dyeing of textile fabrics, I take a solution of the salt to be
used, and boil in it the substance to be operated upon, and afterwards in
any solution or decoction of an animal or vegetable tinctorial substance, as
cochineal, madder, lac dye, logwood, or Persian berries, or it may previously
have been boiled in acetate of alumina, red liquor, or the salt of any metallic
oxide. It may then be winced and carried through the other operations
well known to the practical dyer.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick William Emerson in the Great Seal Patent Office
on the 1st November 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
WILLIAM EMERSON, of 110, Fenchurch Street, in the City of London, 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 fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Frederick William Emerson, Herspecial licence that I, the said Frederick
William Emerson, my executors, administrators, and assigns, or such others as
I, the said Frederick William Emerson, 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 "IMPROVEMENTS IN TREATING ORES TO OBTAIN A NEW METALLIC
SUBSTANCE AND ITS SALTS, AND IN THE APPLICATION OF SUCH MATTERS, AND ALSO
CERTAIN PRODUCTS OF TUNGSTEN IN DYEING, PRINTING, AND PAINTING," upon the
condition (amongst others) that I, the said Frederick William Emerson, 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

page_text: within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Frederick William Emerson, 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:-
I now proceed to state the methods to be used for carrying my Invention
into effect. It consists, firstly, in the separation of a metallic substance, which
I believe to be entirely new, and which I propose to call chrolithineum, from
the so-called ores of tungsten, such as wolfram, tungstate of lime, tungstic
oxide, and others, and the manufacture and application of its various salts
to useful purposes in the arts, such as dyeing textile fabrics, painting on
porcelain, and the production of paints and pigments.
Secondly, in the manufacture and application of the so-called blue
oxide of tungsten as a dyeing substance for textile fabrics and as a paint
or pigment.
Thirdly, the production of paratungstate of alkali, metatungstate of alkali,
isotungstate of alkali, and polytungstate of alkali, which may be used in the
preparation of paints and pigments, and for dyeing textile fabrics and other
usefulpurposes,and the combination of paratungstic, metatungstic, isotungstic,
and polytungsticacids with any suitable metallic oxide, or mixtures of metallic
oxides as a base, such as the oxides of lead, zinc, barytes, lime, and others, to
form paints and pigments. Firstly, I take a fair sample from the bulk of the ore
of tungsten to be operated upon,and make several trial assays with the same kind
of alkaline salt or salts to be used for the bulk in order to determine the pro-
portions that will give the best yield of the oxide or salts of chrilothineum,and
then mix the bulk of ore in the proportions determined by the trialassays with
any caustic alkali, or alkaline salt, or caustic alkaline earth, or alkaline earthy
salt,or any mixtures of the same, such as will decompose the ore to be treated,
and put the mixture into any convenient retort of iron or fire-clay set in a
furnace, and submit the same to heat, and conduct the resulting vapours into
any convenient condensing chamber or vessel; the product so obtained (which
I call the salts or oxides of chrolithineum, as the case may be) in some cases
are at once fit for various uses in the arts, as dyeing textile fabrics, preparation
of paints and pigments. In other cases they require to be first purified by. re-
crystallization, or sometimes it may be more convenient as well as economical
to obtain the salt of chrolithineum in one form, and afterwards to convert it
into another desired form or combination by any of the means well known to
chemists. The solid matter left in the retort after the before-mentioned

page_text: vapours have been driven on may then be used in the preparation of the
various oxides and salts of tungsten.
To produce the chrolithineum in its metallic form, I take the oxide or salt
produced as aforesaid, or by any other means, and mix the same with charcoal,
coal, or coke dust or oil, or tar, or any other carbonaceous or reducing matter,
and submit the same to a strong heat in a covered crucible placed in an
air blast, reverberatory, or other convenient form of reducing furnace; or I
put the salt or oxide before mentioned into a retort furnace, either with or
without mixing with it any of the before-mentioned reducing matters,and pass
over it while at a strong heat a stream of hydrogen, or carburetted hydrogen
or common coal gas, or in some cases it may be found more convenient to
reduce it by means of sodium or potassium..
To produce the blue oxide of tungsten, I take a soluble alkaline salt of
tungsten, and having placed in it (either in a hot or cold solution) metallic
tin, zinc, or other similar reducing or deoxidizing metallic agent, I add by
degrees a muriatic, sulphuric, acetic, or other suitable acid until it cease to
give any further precipitate. In dealing with quantities, it will generally
be necessary to allow the action to continue for some hours until any precipi-
tated tungstic acid is entirely converted into the blue oxide. When the
desired depth of color is attained, the blue oxide may be separated by sub-
sidence and decantation, or by filtration, and should be quickly and thoroughly
dried, and the supernatant liquor evaporated to the crystallizing point to
recover the salt of the deoxidizing metal used if it be commercially valuable.
When it is designed to apply the blue oxide of tungsten to any use requiring
any considerable stability and permanency, if it has been produced in the
manner just described, I prefer afterwards to pass it through the same process
as hereafter described for the conversion of tungstic acid into the blue oxide,
and which process,as a general rule, I prefer both for economy and stability of
colour. It is as follows:-I take tungstic acid, or any other acid oxide of
tungsten, by whatever means produced, and place the same in any convenient
retort of iron, fire-clay, or other refractory material, which may be fitted up
internally with perforated shelves to receive the tungstic acid, or the retort
may be made to rotate on its axis, or a system of stirrers may be used, or any
other means that will presenta continually fresh surface to the reaction taking
place in the retort. The cover or door of the retort being well luted on, I
raise the furnace to a low red heat, and continue to pass over or through the
tungsticacid a stream of hydrogen, carburetted hydrogen, or common coal gas,
or carbonic oxide, until the tungstic acid is thoroughly converted into the blue
oxide, which may be ascertained by drawing a sample through a small part

page_text: hole in the retort. I then allow the furnace to get quite or nearly quite
cold before drawing the charge, otherwise it should be withdrawn very'
expeditiously into any convenient air-tight receiver, as it is very apt to
degenerate in color if exposed to atmospheric influences in a heated state.
To prepare paratungstate of alkali, I thoroughly mix the ore of tungten to
be treated with its equivalent of caustic or carbonated alkali, or alkaline salt,
that will decompose the ore of tungsten or mixtures of the same, and put the
same into a retort, or reverberatory, or other convenient form of furnace, and
continue it at a bright red heat until the ore of tungsten is decomposed or
nearly so, and the combination of the tungstic acid and the alkali effected.
If sulphate of alkali is used, I mix with it sufficient coal, coke, or charcoal
dust, or other carbonaceous material, to effect the decomposition of the
sulphate, and during the melting of the mixture allow an access of atmo-
spheric air. I then withdraw the charge from the furnace, and dissolve out
with either hot or cold water the soluble tungstate of alkali, and to the clear
solution (by preference kept in a boiling state) I add very cautiously by
degrees tungstic acid (by whatever means obtained), by preference tungstic acid
recently precipitated from tungstate of alkali by hydrochloric acid, until the
solution ceases to give a precipitate on the addition of a little dilute nitric acid,
which will be the indication of its conversion into paratungstate of alkali; it
nay then be used in the preparation of paints and pigments, or as a mordant
in dyeing textile fabrics or otherwise, or may be first. evaporated and crystal-
lized; or, I produce tungstate of soda by boiling the ore of tungsten with its
equivalent of any caustic alkali, and afterwards convert it into paratungstate of
alkali by theaddition of recently precipitated tungstic acid, as already described.
To prepare the metatungstate of alkali, I boil for several hours a solution
of paratungstate of alkali, obtained as before described, or any other means,
which, when cool, I filter or decant off the clear solution, and evaporate it
to syrupy consistency, and then set aside to crystallize in any convenient
vessel. The metatungstate of alkali so produced, or by any other means,
may then be used in the preparation of paints and pigments, or as a
mordant in dyeing textile fabrics.
To prepare the isotungstate of alkali, I boil the metatungstate of alkali,
obtained as last described, or by any other means, with an excess of caustic
alkali, and evaporate it to dryness, and heat it at a low red heat in any con-
venient furnace, and afterwards dissolve out the isotungstate of alkali with
either hot or cold water, and evaporate it to the crystallizing point, and set it
aside in any convenient vessel to crystallize. It is then ready to be used in
the preparation of paints and pigments, or as a mordantin dyeing textile fabrics.

page_text: To prepare the polytungstate of alkali, I take tungstic acid, obtained by the
action of a strong mineral acid, or a mixture of sulphuric acid and salt, on
finely powdered wolfram, and digest the tungstic acid so obtained in a solution
of caustic alkali, which, when saturated, I evaporate very slowly, separating
first, paratungstate of alkali, and afterwards isotungstate of alkali, the mother
liquor; I then evaporate till it assumes a brownish color; in this state I leave
it in a state of quietude for some time, until it separates into two distinct layers
or strata, one of which is brown and syrupy; to this I add boiling hydro-
chloric acid, which throws down polytungstic acid, which I separate by filtration
or decantation, and afterwards digest in caustic alkali, and evaporate the
solution to the crystallizing point, and set it aside in any convenient vessel
to crystallize. It is then ready to be used in the preparation of paints and
pigments, as a dyer's mordant, or other useful purposes.
I will now describe some of the useful purposes to which the foregoing
products from the ores of tungsten may be applied in the art of dyeing various
colors in textile fabrics and in the production of paints and pigments. The
infinite variety of combinations of which they are capable with other metallic
oxides and vegetable and animal tinctorial substances, for the productions
of paints and pigments of various shades and colors, and in dyeing textile
fabrics, is so great, that a few examples will suffice to give the key by
which the practical chemist and dyer will be enabled to operate.
To produce paints and pigments from the before described so-called salts of
chrolithineum, I take the solution of the said salt either alone or mixed with
the salt of any other metallic oxide that will not cause a precipitate, and add
to it the salt of any other metallic substance that will cause a precipitate, with
or without the addition ofany vegetable or animaltinctorial matter, as madder,
cochineal, or others, in this manner an almost infinite variety of changes may
be made so as produce variety of colors and shades. For an example, I
take a solution of a salt of chrolithineum, and pour into it a solution of bichro-
mate of potash; the precipitate, which is a brilliant and very permanent yellow,
after being well washed and dried, is ready to be ground in oil, turpentine,
varnish, or other suitable vehicle, and used as a paint or pigment, or for
painting in porcelain, &c. In dyeing the same into any textile fabric, I boil
the substance to be operated upon either in the skein or in the piece, in a
solution of the salt of chrolithineum, and after drying it immerse it in a hot
or cold solution, or boil it in a solution of bichromate of potash, and after
thoroughly rinsing and carrying it through the other operations well known to
dyers, it gives a very fine permanent yellow, or previously to rinsing it may be
boiled in a solution of madder, which will produce it of a brilliant orange colour.

page_text: I have already stated the manner in which the blue oxide of tungsten
may be produced; and for use as a paint or pigment it only requires to be
mixed or ground in oil, turpentine, varnish, or other suitable vehicle to be
ready for use. To dye the blue oxide of tungsten into textile fabrics, I take
the substance to be dyed either in the skein or in the piece, and boil it in an
alkaline salt of tungsten, and after drying immerse it in dilute muriatic, sul-
phuric,acetic, or other suitable acid, in which is placed metallic zinc,tin,or other
deoxidizing metallic agent, and continue the operation either with or without
heat until the desired depth of color is obtained, and the blue oxide thoroughly
combined with the fibre of the substance acted on. It may then be rinsed
and carried through the other operations well known to practical dyers.
To produce paints and pigments from the before-described paratungstate,
metatungstate, isotungstate, or polytungstate of alkali, I take the clear solu-
tion of any of those salts produced as before described, or by any other
means, and add it to the clear solution of a salt of a metallic or earthy
oxide, as acetate or nitrate, or chloride of lead, zinc, barytes, or lime, or
mixtures of the same. The precipitate, after being thoroughly washed and
dried, is ready to be ground in oil, turpentine, varnish, or other suitable
vehicle, and used as a paint or pigment.
In using paratungstate, metatungstate, isotungstate, or polytungstate of
alkali for the dyeing of textile fabrics, I take a solution of the salt to be used,
and boil in it the substance to be operate upon, and afterwards in any solu-
tion or decoction of an animal or vegetable tinctorial substance, as cochineal,
madder, lac dye, logwood, or Persian berries, or it may previously have
been boiled in acetate of alumina, red liquor, or the salt of any metallic
oxide. It may then be rinsed and carried through the other operations
well known to the practical dyer.
In witness whereof, I, the said Frederick William Emerson, have
hereunto set my hand and seal, this Twenty-seventh day of October,
in the year of our Lord Oue thousand eight hundred and fifty-nine.
F. W. EMERSON. (L.S.)