IMPROVEMENTS IN THE MANUFACTURE OF 'PIGMENT' COMPOUND TO BE USED IN THE PREPARATION OF 'CARBON' TISSUE
Year: 1878

page_text: LETTERS PATENT to Oliver Sarony, of Scarborough, in the County of York,
and John Robert Johnson, of Red Lion Square, in the County of Middlesex,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF 'PIGMENT'
COMPOUND TO BE USED IN THE PREPARATION OF 'CARBON' TISSUE."
Scaled the 13th September 1878, and dated the 1st July 1878.
PROVISIONAL SPECIFICATION left by the said Oliver Sarony and John
Robert Johnson at the Office of the Commissioners of Patents on the 1st July
1878.
:
OLIVER SARONY, of Scarborough, in the County of York, and JOHN ROBERT
JOHNSON, of Red Lion Square, in the County of Middlesex. "IMPROVEMENTS IN
THE MANUFACTURE OF PIGMENT' COMPOUND TO BE USED IN THE PREPARATION
OF 'CARBON TISSUE."
It is well known that glue or gelatine is a substance which dissolves in hot
water and that the solution becoines set or chilled in the form of jelly as the
temperature descends, the point at which the solution sets or gelatinizes varying with
the strength or quality of the gelatine. The higher the temperature of gelatinization
the better the gelatine.
It is also well known that the jelly so set loses this quality if the solution be
heated for a long period, and loses this more rapidly by alternate heating and
cooling, the temperature at which the jelly resets becoming lower after each
remelting of the jelly.
It is well known also that gelatine is used for the preparation of pigment paper
or "tissue," as it has been called, for the purpose of photographic printing by the
process known as the carbon process. For this purpose the gelatine is redissolved
and mixed with sugar and with various pigments.
It is also notorious that the operation of preparing this paper is one of extreme
uncertainty, it being difficult to obtain two samples of pigment paper of the same

page_text: quality unless made simultaneously, the nature of the gelatine varying with the
longer or shorter duration of the heating, grinding, and stirring processes.
Now according to the present Invention we avoid this uncertainty and obtain a
piginent compound of definite composition by adding the sugar and colouring
matter to the gelatine while it is in the state of its first solution after being obtained
from the skins, bones, or other raw material, stirring well to incorporate the whole,
and after the colouring matter has been well stirred into the solution we pour it
into moulds and dry it in thin pieces in the ordinary way. When these are cut
up into extremely thin strips they have only to be dissolved by the photographer
and employed in the manufacture of tissue in the usual way.
]
SPECIFICATION in pursuance of the conditions of the Lotters Patent filed by
the said Oliver Sarony and John Robert Johnson in the Great Seal Patent
Office on the 1st January 1879.
OLIVER SARONY, of Scarborough, in the County of York, and JOHN ROBERT
JOHNSON, of Red Lion Square, in the County of Middlesex. "IMPROVEMENTS IN
THE MANUFACTURE OF PIGMENT' COMPOUND TO BE USED IN THE PREPARATION
OF CARBON' TISSUE."
'
It is well known that glue or gelatine is a substance which dissolves in hot water
and that the solution becomes set or chilled in the form of jelly as the temperature
descends, the point at which the solution sets or gelatinizes varying with the
strength or quality of the gelatine. The higher the temperature of gelatinization
the better the gelatine.
It is also well known that the jelly so set loses this quality if the solution be
heated for a long period, and loses this more rapidly by alternate heating and
cooling, the temperature at which the jelly resets becoming lower after each
remelting of the jelly, a soluble non-gelatizing compound being formed in the
process.
It is well known also that gelatine is used for the preparation of pigment paper
or "tissue," as it has been called, for the purpose of photographic printing by the
process known as the carbon process. For this purpose the gelatine is redissolved
and mixed with sugar, and the mixture is then heated, churned, and mixed with
various pigments.
It is also notorious that the operation of preparing this paper is one of extreme
uncertainty, it being difficult to obtain two samples of pigment paper of the same.
quality unless made simultaneously, the nature of the gelatine varying with the
longer or shorter duration of the heating, cooling, and stirring, or churning purposes.
Now according to the present Invention we avoid this uncertainty and obtain a
piginent compound of definite composition by adding the sugar and coloring
matter to the gelatine while it is in the state of its first solution after being
obtained from the skins, bones, or other raw material, stirring well to incorporate

page_text: the whole, and after the coloring matter has been well stirred into the solution.
we pour it upon plates or slabs and dry it in thin pieces in the ordinary way.
When these are cut up into extremely thin strips they have only to be dissolved
by the photographer and employed in the manufacture of tissue in the usual
way.
Having stated the nature of our Invention we will proceed to describe more
fully the mode in which we carry the same into practical oporation.
Having obtained a concentrated solution of golatine direct from the pan of the
maker and before the same has been "slabbed " and dried, we evaporate to-dryness
in a water bath a known quantity of the same in order to ascertain the per-centage
of solid gelatine contained in the concentrated solution which is duly noted.
the non-
Another weighed or measured portion is poured upon glass in a thin layer and
the film so obtained when solidified is well washed in cold water;
gelatinizing part of the compound soluble in cold water washes out of the film of
jelly, and when this has been done the film is liquefied and evaporated to dryness,
as before, to ascertain the per-centage of solid matter which it also contains after it
has been exhausted of its non-gelatinizing part by water. The solid matter found
will be less than in the former caso, and the difference of the two weights is that.
of the non-gelatinizing matter present in the original sample. Knowing now the
relative proportion of gelatinous matter soluble in cold water to that of the non-.
soluble matter or real gelatine, as it may be called, we add sugar to a known weight.
of the concentrated solution in such quantity that the soluble portion, plus the.
sugar, may be one half by weight of the insoluble or real gelatine. We thus obtain
a definite mixture which we use as the medium for the preparation of the pigment.
compound.
That the method of operating just described may be more easily understood we
will give an example as found in practice. Let us suppose that the evaporation
of 100 parts by weight of the concentrated solution yields on simple evaporation
20 per cent. of solid matter, and that the evaporation of 100 parts of solidified
gelatino after well washing yields only 18 parts.
L
The composition of the original bulk or mass is therefore,―
DL
According to our experience the relative proportions of soluble matters to insoluble
gelatine just given are the best for the pigment compound to be used for paper or
tissue for the double transfer process. When the compound is required for single
transfer paper, and when working in a hot and dry atmosphere, more sugar may
be required, but as sugar can be easily added to the compound and not withdrawn
therefroin we prefer the proportions given.
Having thus obtained what we call our standard jelly we add to such a portion
of it as represents or contains 25 pounds of real gelatine one pound of Indian ink
softened and diffused through at least one gallon of water in order to obtain an
intense black pigment compound. To another like portion of "standard jelly" we

page_text: add one pound of Indian ink and two pounds of the alizarine lake, described in the
Specification of Letters Patent granted to William Morgan-Brown, dated April 7,
1877, No. 1367. This must be ground with slab and muller, or in a suitable mill, to
an extremely fine state of division, using very thin solution of gelatine as the
medium or vehicle for the grinding process, as is well understood. We obtain
thus a purple tint closely imitating that 'produced by photographic printing by
the ordinary silver process.
We would observe that there may be considerable variations in the proportions
of colour to that of the gelatine. One-half or even one-third of the quantities
given will yield a pigment compound which will give pictures. The proportions
of pigment given are indeed somewhat extreme and will only be found suitable for
certain classes of subjects, but as density of pigment can be easily diminished by
the addition of a standard jelly, gelatine and sugar, but cannot be increased, we
prefer to make our compound as stated, but wo do not bind ourselves to these
quantities.
A great variety of colours may be produced by using the various pigments of
the artist, which, however, must be such as have no action upon the gelatinous
medium. Whatever colours be employed they must be brought to a state of
extreme division by grinding such as are insoluble upon a slab or in suitable mills,
using weak size as the medium or vehicle, as is well understood. We carefully mix
or diffuse them through the mass of "standard jelly".still in the liquid state,
adding at the same time one-thousandth part of carbolic acid, and we stir the whole
till a perfectly homogeneous mass has been obtained. The coloured compound is
then slabbed," dried, and cut up exactly as ordinary gelatine.
We also prepare for the purpose of diluting our pigment compounds and for the
use of those persons who may still prefer to add the colouring matter thereto, a
standard gelatine without colour and containing a definite proportion of sugar and
soluble matter to the real gelatine.
We have stated that we "slab," dry, and cut up our pigment compound made
as described exactly like ordinary gelatino, but it is obvious that such may be
used in the humid state as originally prepared, that is to say, solidified but not
desiccated.
Having thus described the nature of our said Invention and the node in which
we carry the same into effect, we would have it understood that what we claim is,
the improvements in the manufacture of "pigment "compound to be used in the
preparation of carbon tissue, substantially as herein described.
In witness whereof, I, the said John Robert Johnson, have hereunto set my
hand and scal, this First day of January, in the year of our Lord One
thousand eight hundred and seventy-nine.