IM- PROVEMENTS IN THE MANUFACTURE OF BLACK OR BROWN PIGMENTS TO BE USED IN THE MANUFACTURE OF PAINTS OR PRINTING INK, AND IN THE TREATMENT AND PREPARATION OF CERTAIN NATURAL PRODUCTS USED IN THE MANUFACTURE OF SUCH PIGMENTS
Year: 1868

page_text: LETTERS PATENT to Paul Rapsey Hodge, of No. 10, Adam Street,
Adelphi, in the Parish of St. Martin's in the Fields, in the County
of Middlesex, Civil Engineer, and William Hodge, of Fowey, in
the County of Cornwall, Mineralogist, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF BLACK OR BROWN PIGMENTS TO BE
USED IN THE MANUFACTURE OF PAINTS OR PRINTING INK, AND IN THE
TREATMENT AND PREPARATION OF CERTAIN NATURAL PRODUCTS USED IN
THE MANUFACTURE OF SUCH PIGMENTS."
Sealed the 16th February 1869, and dated the 18th August 1868.
PROVISIONAL SPECIFICATION left by the said Paul Rapsey Hodge
and William Hodge at the Office of the Commissioners of l'atents,
with their Petition, on the 18th August 1868.
We, PAUL RAPSEY HODGE, of No. 10, Adam Street, Adelphi, in the
5 Parish of St. Martin's in the Fields, in the County of Middlesex, Civil
Engineer, and WILLIAM HODGE, of Fowey, in the County of Cornwall,
Mineralogist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF BLACK OR BROWN PIGMENTS TO BE

page_text: USED IN THE MANUFACTURE OF PAINTS OR PRINTING INK, AND IN THE TREATMENT
AND PREPARATION OF CERTAIN NATUPAL PRODUCTS USED IN THE MANUFACTURE
OF SUCH PIGMENTS," to be as follows:-
Our improvements consists in the employment of certain natural
products in the manufacture of black, brown, or red pigments, to be used
in the compounding of paint or printing ink. Such natural materials to
be so treated and amalgamated in their proper equivalents to suit the end
intended.
We first take a yellow, brown, or red ochre, finely washed, and "slop"
the material in a large cast kettle of any desired size. In another vessel
of like kind we wash highly carbonised peat, so as to deprive it of fibre
and all earthy matter. When the peat "slop" is thrown into and mixed
with the ochre "slop" and so managed with a fire underneath, keeping
up at the same time motion in the "slop" not to allow the heavier
particles to precipitate from, the lighter, and so keep stirring them until
the slop" get to a consistancy that separation will be impossible. The
material is then dried perfectly free of aqueous matter, and is then placed
into a close retort (revolving or otherwise); it is kept free from air in
any way, as the admission of oxygen would prevent the material from
becoming black; the heat of the retort not to exceed a "low red." The
oxide of iron in the material without air becomes a carbide of iron and
allumina, or, in the absence of allumina a simple carbide of iron. We
also take the slopped" material composed of ochres or pure oxides, or
magnetic oxides, or susqua-oxides, or any earth containing iron in any
of the above forms, and slop them with ground lignite, anthracite, or
bitumenous coal, or soot prepared from coal smoke, or any other car-
bonacious material in combustion, and "slop" them together as before
described; then dry and retort them for say th of an hour at a low red
heat, when they are converted into a black pigment, dense in its character,
and of excellent colour.
Another method in preparing a black is in carbonising it wholly with
soot," which may be used in its crude state or prepared by revòlatolising
and when passing it through the flue to bring it into contact and
comingle the smoke with steam. The object being to deprive the soot of
its pyroligneous acid and ammonia, which the steam takes off and the
soot is thrown down free and pure, this used in combination with the
oxides (magnetic or otherwise), or in combination with any of the ochres

page_text: previously described, or combinations of proper portions of soot and
washed peat slopped and mixed in their proper equivalents, with any of
these metallic compounds retorted and kept free of air during the process
of retorting, will produce a black pigment adapted to every use and of
excellent colour. If we require to make brown or red we merely let in
air into the retort during the process, which takes up oxygen in any
proportion according to the colour required. Or we make any of the
oxides of iron by means of retorting the sulphate of iron, known in com-
merce under the name of copperas, and retort it with the carbonacious
materials such as soot, peat, any of the lignites, or coals, and retorting
them as before described.
Another combination of materials would be in the salts of iron,
sulphate of iron, China clay, or alluminous earth, and soot or peat (or
both in combination) when "slopped" or mixed dry, and retorting as
described, produces a black of much density and good in colour.
For colours used for finer purposes, and that which do not require so
much body, we use soot and sulphate of iron mixed and retort them;
the sulphuric acid is driven off from the salt of iron, the ammonia and
pyrolegneous acid is driven off from the soot, and a union takes place
giving the carbon of the soot an addition of the carbide of iron.
For blacks of greater density we use peat and soot as a carboniser in
combination with any of the ochres or oxides of iron as before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Paul Rapsey Hodge and William Hodge in the
Great Seal Patent Office on the 16th February 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, PAUL
RAPSEY HODGE, of Number 10, Adam Street, Adelphi, in the Parish
of Saint Martin's in the Fields, in the County of Middlesex, Civil
Engineer, and WILLIAM HODGE, of Fowey, in the County of Cornwall,
O Mineralogist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of August, in the year of
our Lord One thousand eight hundred and sixty-eight, in the
year of Her reign, did, for Herself, Her heirs and successors, give

page_text: and grant unto us, the said Paul Rapsey Hodge and William Hodge,
Her special licence that we, the said Paul Rapsey Hodge and
William Hodge, our executors, administrators, and assigns, or such
others as we, the said Paul Rapsey Hodge and William Hodge,
our 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 THE MANUFACTURE OF BLACK OR BROWN PIGMENTS TO BE
USED IN THE MANUFACTURE OF PAINTS OR PRINTING INK, AND IN THE TREATMENT
AND PREPARATION OF CERTAIN NATURAL PRODUCTS USED IN THE MANUFACTURE OF
SUCH PIGMENTS," upon the condition (amongst others) that we, the
said Paul Rapsey Hodge and William Hodgo, our executors or adminis-
trators, by an instrument in writing under our, 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 we, the said Paul Rapsey Hodge and William
Hodge, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
Our Invention consists in the employment of certain natural products
in the manufacture of black or brown pigments to be used in the com-
pounding of paints or printing ink, such natural materials to be so
treated and amalgamated in their proper equivalents to suit the purposes
intended.
Chapter 1.) We, for one of the forms of pigments, take a yellow,
brown, or red ochre, oxides, or protoxides, or peroxides, or susqua-
oxides of iron, or any of the alluminous earths wherein iron forms a
portion of the compound, whether it be a chromate, oxide, protoxide,
peroxide, susqua-oxide, carbonate, sulphite or sulphate of iron, and grind
them to an impalpable powder; they are then washed and "slopped
in a vessel of any size required for the quantity. In another vessel of
ike kind we wash and "slop" highly carbonised peat so as to deprive it

page_text: of fibre and earthy matter.
When both these "slops" above described
are complete they are mixed together in an iron vessel with a fire under-
neath, at the same time a motion is kept up in the "slopped" material to
prevent the heavier material separating from the lighter, and to ensure a
proper comingling of the two materials the fire and motion are kept up
until the aqueous matter is nearly evaporated when the " slopped "
materials get to a consistancy that separation is impossible. The
material so compounded is dried on a kiln or any other suitable place.
It is then placed into a close retort either of clay or iron and kept
perfectly free from air, as the admission of oxygen would prevent the
iron compound in the material from taking up the carbon. A fire is
placed under the retort for the space of an hour or more at a red heat,
when the whole material is converted into a black pigment.
Chapter 2.)-We also take a "slopped "material composed of ochres or
pure oxides, or magnetic oxides, peroxides, or susqua-oxides, or any earth
containing iron in any of the above forms, and "slop" them as before
described with ground lignite, anthracite, or bituminous coal or soot
prepared from coal smoke, or any of the carbonacious materials in combi-
nation, "slop" them together, and dry them as before described. When
dry and perfectly free of aqueous matter the material is placed into a
close retort as before described and heated to a red heat for a given time,
and converted in like manner into a black pigment, dense in its character
and of excellent colour.
Chapter 3.) Another method of preparing a black pigment of any of
the former compounds of iron is in carbonising it wholly with soot,
which may be used in its crude state or prepared by revolatalising soot
by heating it in a retort and passing it off again in the form of smoke
from the retort into a flue, where it is brought into contact and comingles
with a jet or jets of highly attenuated steam which will deprive the soot
of the amoniacal matter and pyroligneous acid it may contain, when
the soot condenses in the flue free and pure. This is used alone as a
pigment or is used in combination with any of the irons or compounds
containing iron in combination, and then "slopped" and retorted in the
ordinary way, as previously described.
Chapter 4.)-Or we take soot so prepared as before described and mix
and "slop" it with the "fatty" or carbonacious portion of peat, and
then "slop" the.compound with any of the materials before named con-
.

page_text: taining iron or with the pure oxides, peroxides, susqua-oxides, or
protoxides of iron, or any of the chromates of iron in the manner
previously described, then submit it (in a close retort as before described)
to the heat desired, when a very superior black pigment will be
produced.
Chapter 5.) Or we take sulphate of iron, known in commerce under
the name of copperas, and retort it in combination with any of the
carbonising materials before described, when an excellent black pigment
is the result; or we infuse carbonic acid gas into the retort during the
process of retorting and agitate the material in the retort with any of the
well-known methods either by revolving the retort itself or by revolving
an agitator internally so as to expose the iron compounds to the action of
the carbon.
Chapter 6.) -Or we make a very pure carbon of intense blackness which
can be used for printers' ink in copper-plate, lithographic, or surface
printing by the revolatalisation or sublimation of soot, and submit it to
the action of highly attenuated or superheated steam to drive off all other
matters it may contain, when the carbon or residue is fit for use.
Chapter 7.)-In making blacks for common purposes we use simple
yellow ochre, where the iron in the earth may be either in the form of a
chromate or an oxide or peroxide, and "slop" them in their proper
equivalents with the "fatty" portion of peat, then dry, and retort as
described in Chapters 2, 3, 4, 5, 6.
The methods herein described in the several chapters referred to for
the conversion of any of the compounds or products of iron a carbide
of iron (or if a brown colour) partial carbide of iron, being new, as far
as relates to the use of the material referred to in the process of car-
bonising. And also the methods herein referred to relative to the
cleansing of common soot and making it into a material fit for printing
ink or paint either by itself or in combination with any of the compounds
as fully set forth in the various chapters referred to.
Having now described the nature of the said Invention, and the
manner of performing the same, we would have it understood that we do
not confine ourselves to the precise manner of manipulating or com-
pounding these natural materials for the purposes set forth, as they may
be varied in the quantities to suit the ends intended; but what we claim

page_text: is, the use of such natural products in the manner and for the purposes
herein set forth and described.
In witness whereof, we, the said Paul Rapsey Hodge and William
Hodge, have hereunto set our hands and seals, this Tenth day
of February, in the year of our Lord One thousand eight hundred
and sixty-nine.
Witness,
THOS. W. WILLIAMS.
GEORGE POOLEY.
PAUL R. HODGE.
(L.S.)
WILLIAM HODGE. (L.S.)