IMPROVEMENTS IN THE MANUFACTURE OF BLACK FOR PAINTING OR PRINTING, WHICH IS ALSO APPLICABLE TO DISCOLORING SUGAR,
Year: 1874

page_text: LETTERS: PATENT to David Clovis Knab, Chemist, of Saint Denis, in
the Department of the Seine, in the Republic of France, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF BLACK FOR
PAINTING OR PRINTING, WHICH IS ALSO APPLICABLE TO DISCOLORING SUGAR,
99
PROVISIONAL SPECIFICATION left by the said David Clovis Knab
at the Office of the Commissioners of Patents, with his Petition, on
the 23rd December 1874.
I, DAVID CLOVIS KNAB, Chemist, of Saint Denis, in the Department
5 of the Seine, in the Republic of France, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF BLACK
FOR PAINTING OR PRINTING, WHICH IS ALSO APPLICABLE TO DISCOLORING SUGAR,
AND FOR USE AS A DISINFECTANT":
The
Caustic lime perfectly crushed and sifted is intimately mixed with gas
tar or other body giving carbon by distillation in closed vessels.
proportions are from 30 to 50 parts of tar to 100 parts of lime.

page_text: As dry caustic lime is difficult to crush it is slacked with the least
possible quantity of water, so as to obtain a well pulverized powder,
which is thoroughly mixed hot with the tar. The intimate mixture
thus formed is placed in a gas retort or in earthenware or iron pots, and
heated to red heat until gas ceases to be given off, the pots are then
withdrawn and allowed to cool, and the cold matter extracted from the
pots is emptied on to a brick floor, and taking up the moisture of the air
falls in powder as pure caustic lime.
•
During carbonisation in the black pots the gases which ignite on
removing the closed pots produce an immense smoke, which being
collected by this means two blacks are obtained, one analogous to bone
black, the other similar to the black of ordinary smoke. The black thus
produced is a rough or raw black suitable for employment like powdered
bone black, such for instance, as blacking and common black colours.
And by treating this rough black with muriatic acid or any other lime
solving acid the lime is completely removed and perfectly pure and
beautiful black is the result.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Clovis Knab in the Great Seal Patent
Office on the 10th June 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
CLOVIS KNAB, Chemist, of Saint Denis, in the Department of the Seine,
in the Republic of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of December, in
the year of our Lord One thousand eight hundred and seventy-four, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said David Clovis Knab,
Her special licence, that 1, the said David Clovis Knab, my
executors, administrators, and assigns, or such others as 1. the said
David Clovis Knab, 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

page_text: The raw or rough black is not solely applicable as a colour. This
combination of caustic lime with the pure black (which does not remove
any quality of the lime) is precious in the manufacture of sugar. In
effect the sugar of lime is produced, as usual, and the presence in
intimate mixture of the black in the primitive form prevents the
colouring of the juices.
The raw or rough black is not solely applicable as a colour. This
combination of caustic lime with the pure black (which does not remove
any quality of the lime) is precious in the manufacture of sugar. In
effect the sugar of lime is produced, as usual, and the presence in
intimate mixture of the black in the primitive form prevents the
colouring of the juices.
For gas tar, may be substituted blood, molasses, gelatine, or other
body giving carbon by distillation in closed vessels, and even by coal
powdered very fine with caustic lime.
During carbonisation in the black pots, the gases which ignite on
removing the closed pots produce an immense smoke, which can be
collected; in this manner two blacks are obtained, one analogous to
bone black, the other similar to the black of ordinary smoke; whilst
by distilling in retorts lighting gas is obtained.
The dry caustic lime is difficult to crush; instead of using it in this
condition I employ other means; I slack the lime with the least possible
quantity of water so as to have a well pulverized powder, which I
intimately mix hot with the tar. In this case the water combined with
the lime, decomposing during calcination a part of the tar in producing
carbonic oxyd, more tar should be used, say about 60 to 100 parts.
Finally, instead of lime, carbonate of lime, which by heat is trans-
formed into lime and definitely produces the same results may be used,
but in this case again more tar is required, since during the whole
liberation of the carbonic acid of the carbonate this carbonic acid
absorbs charcoal to transform itself into carbonic oxyd.
In all cases the solution of the lime of the raw black by the muriatic
acid always produces a pure and beautiful black.
It is understood that I reserve the use of any other base, magnesia
for instance, producing the same effect as the lime, only making use of
this for economy.
My Invention rests in the employment of lime, soluble in muriatic
or other acids, calcined with tar or other carbonaceous matters, for
producing a raw or rough black which can be directly employed in the
ordinary usages of bone blacks, and in the production of discoloured

page_text: unequalled black.
In witness whereof, I, the said David Clovis Knab, have hereunto
set my hand and seal, this Twenty-ninth day of May, in the
year of our Lord One thousand eight hundred and seventy-
.five.
DAVID CLOVIS KNAB. (L.s.)