IMPROVEMENTS IN THE MANUFACTURE OR PREPARATION OF PAINTS, PIGMENTS, AND COLOURS
Year: 1862

page_text: LETTERS PATENT to Robert Hicks, of Kensington Park Terrace, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OR PREPARATION OF PAINTS, PIGMENTS, AND COLOURS."
Sealed the 2nd December 1862, and dated the 14th June 1862.
PROVISIONAL SPECIFICATION left by the said Robert Hicks at the Office
of the Commissioners of Patents, with his Petition, on the 14th
June 1862.
I, ROBERT HICKS, of Kensington Park Terrace, in the County of Middlesex,
Gentleman, do hereby declare the nature of- the said Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OR PREPARATION OF PAINTS, PIGMENTS, AND COLOURS,'
to be as follows:-
My Invention of improvements in the manufacture or preparation of paints,
pigments, and colours consists in the employment of the debris of slate works
and quarries as a base for the manufacture of paints, pigments, and colours.
In carrying out my Invention I take the broken or pulverized slate, whicn is
at present nearly if not quite useless, and reduce it to a very fine powder.
The powder may be mixed with oil or water, with the addition of any suitable
colouring matters, such as ochre, lampblack, oxide of iron, or other substance,
whereby the pigment may be brought to the desired shade of colour. For
some colours the slate debris is to be calcined or roasted so as to peroxydize it,
whereby its colour will be considerably altered. The, roasted or calcined slate

page_text: may be ground up and mixed as before with oil or water, with the addition
of other ingredients. to alter, modify, or vary the shade, the slate forming the
base of the pigment.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Hicks in the Great Seal Patent Office on the
13th December 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
HICKS, of Kensington Park Terrace, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of June, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year. of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me,, the said Robert Hicks, Her special license that I, the said Robert
Hicks, my executors, administrators, and assigns, or such others as I; the
said Robert Hicks, 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
THE MANUFACTURE OR PREPARATION OF PAINTS OR PIGMENTS AND COLOURS,"
upon
the condition (amongst others) that 1, the said Robert Hicks, by an
instrument in writing under my hand and seal; 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 Robert Hicks, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the follow-
ing statement (that is to say) -
My Invention of "Improvements in the Manufacture or. Preparation of
Paints or Pigments and Colours" has for its object the useful employment of
the debris or detritus obtained in slate quarries or slate works, in combination
with any one of the known carbons or charcoals, such as lamp black, ivory black,
and such like matters, or of any of the substances containing sufficient carbon.

page_text: -
These ingredients or schists or schistose substances, with the addition sometinies
of oxide of iron or hematite iron ore are intimately mixed together and subjected
to the action of heat, whereby their chemical.constitution becomes modified,
so that when subsequently pulverized they may be advantageously employed
as a paint, pigment, or colour. When using slate which contains from ten. to
fifteen per cent. of oxide of iron, I do not find it necessary for the. purposes..of
my Invention to add any hematite iron ore, or oxide of iron, but when using
slate or any of the various clays or schists that do not contain sufficient oxide of
iron in themselves, I mix the slate, clay, schist, or schistose, substances in a
pulverized state with the carbonaceous materials, and I add thereto! from five
to ten per cent of pulverized hematite, or other iron ore, the quantity of oxide
of iron to be added to the slate or schistose substances employed varying of
course with the ferruginous quality of the schistose substances: The whole
of the ingredients are intimately incorporated together and then submitted;to
the action of heat in the manner hereafter 'described. I prefer however to:use
for the purposes of my Invention slate or schistose substances which, are found
to contain sufficient iron in themselves; such substances when well pulverized
may be mixed with the carbonaceous matters without the addition of the
hematite or other iron ores and then submitted to the subsequent process.
In carrying out my Invention when using slate I-reduce the slate, to a fine
powder and mix. it with the carbonaceous matters and with the proper per
centage of iron ore when required and also reduced to a fine powder. These
ingredients when thoroughly incorporated are put into a covered retort or
crucible, from which the atmosphere is excluded, leaving however a small
aperture in the upper part of the retort or crucible for the escape of the
vapours or gases that may be given off. The time required to heat the
mixture must depend upon the quantity operated upon, the size of the retort,
and the energy of the fire. The object to be attained is to cause the carbon
to act upon and partially deoxydize the oxide of iron and thereby reduce the
ingredients to a black mass. When the retort or crucible is removed from
the fire and the contents have become cold, the cover may be removed and
the calcined mixture may be pulverized, and black paint will be thereby
produced. It should be observed that the colour of the mixture would be
injured if it were removed from the retort or crucible while hot. The process
above explained is that adopted or employed for making black paint when
manufacturing lighter colours. I put the slate clay, slate schist, or schistose
substances reduced to powder into an open vessel or crucible, which is placed in
a furnace and kept therein until the carbon contained in these substances is
burned away and the iron therein is peroxydized. The colour produced is

page_text: a fawn or salmon colour, which may be varied in shade by an admixture of
different coloured materials, such as ochres of different colours, hematite iron,
and other suitable substances.
For some purposes I simply pulverize the slate and after reducing it to
an impalpable powder I mix it with oil or water; this mixture makes a grey
paint or a delicate grey colour. In other instances I mix the- pulverized slate
with different coloured ochres or other matters suitable for producing a variety
of tints, afterwards using oil or water as before mentioned in manufacturing
the paints or colours. The black powder produced by the process already
described may be employed as the body colour used in the manufacture of
black lead, for which purpose it is mixed with plumbago.
Having now described my Invention of "Improvements in the Manufacture
or Preparation of Paints or Pigments and Colours," and having explained the
manner of carrying the same into effect, I claim as the Invention secured to
me by Letters Patent as. aforesaid, the mode or modes herein set forth of
preparing slate, clay slate, schist, or schistose substances for the manufacture
of paints, pigments, or colours.
In witness whereof, I, the said Robert Hicks, have hereunto set my hand
and seal, the Thirteenth day of December, in the year of our Lord
One thousand eight hundred and sixty-two.
101
ROBERT HICKS. (L.S.)