IMPROVEMENTS IN PHOTOGRAPHY APPLICABLE TO PHOTOGRAP
Year: 1881

page_text: LETTERS PATENT to Leon Warnerke, of Champion Hill, in the County of
Surrey, for an Invention of "IMPROVEMENTS IN
PHOTOGRAPHY."
23
AND APPLICABLE TO
PROVISIONAL SPECIFICATION left by the said Leon Warnerke at the Office
of the Commissioners of Patents on the 1st April 1881.
LEON WARNERKE, of Champion Hill, in the County of Surrey.
IN AND APPLICABLE TO PHOTOGRAPHY."
"IMPROVEMENTS
My Invention is based on the property possessed by colloidal substances, such as
gelatine, dextrine, albumen, gum, or such like in combination with silver-compounds,
to become insoluble or in part insoluble in those parts which receive deposit of
silver or silver compound through developement on the parts affected by light.
In carrying out my Invention I adopt mainly the following mode of pro-
cedure :-
Sensitive colloidal film or films produced on paper or any other suitable medium
by means of emulsion or by bath process, is exposed to light either in the camera
or otherwise developed in the manner generally adopted, fixed or not fixed. This
film with developed image is next put in contact with suitably prepared glass,
transfer paper, or any other surface, and plunged in warm water or other liquid
through the action of which all the colloidal parts remaining soluble will be
dissolved, while the image consisting of insoluble parts only remains attached to
the glass, or the su face on which it was thus developed.
This process can be applied,―
(1.) To the production of negatives, offering great advantages over existing
modes of obtaining them in one respect, that they can be intensified by many
known methods without staining the film. They are reversed, but by using
transfer paper this can be obviated.
(2.) The production of positives, and for reproductions of negatives, or for
enlarged negatives.

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(3.) For productions of relief images, such as are used for Woodbury process,
photo-réliefs, photo engravings, phototypes, and such like processes known under
the general name of photo mechanical printing processes.
(4.) For ordinary printing. In this case any coloring matter being admixed to
the emulsion or colloidal bodies will improve the tone of the image.
(5.) For photo-ceramic pictures.
(6.) For photography-on-canvas and wood.
(7.) For phototype or colotype processes.
The special point or feature of my Invention principally consists in removing by
solution of the part of colloidal body in which silver is not precipitated by the
agency combined of light and developer, and by applying solvent on the side of the
film opposite to the surface on which the light has acted.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Leon Warnerke in the Great Seal Patent Office on the 1st October
1881.
C
LEON WARNERKE, of Champion Hill, in the County of Surrey. IMPROVEMENTS
IN AND APPLICABLE TO PHOTOGRAPHY."
My Invention is based on the property possessed by colloidal substances, such as
gelatine, dextrine, or such like, in combination with silver compound to become
insoluble or in part insoluble in those parts which receive deposit of silver cr
silver compounds through the action of developer on the parts affected by light.
In carrying out my Invention I adopt substantially the following mode of
procedure-Sensitive colloidal film or films is produced on paper or any other
suitable medium by means of emulsion, or by bath process. Among many systems
that can be employed for the formation of the film mentioned before, the following
can be adapted -For the preparation of the sensitive emulsion, two solutions are
prepared (in the dark); (1) pure soluble gelatine, 10 grm.; ammonia bromide,
35 grm.; water, 180 grm.; (2) silver nitrate, 50 gr.n.; water, 180 grm. Both
solutions being raised to the temperature of 35° to 40° C. are carefully, slowly, and
with constant stirring mixed together. The mixture is boiled 10 to 45 minutes,
and after cooling to 30°, fresh gelatine (50 grm.) is added, and naturally or
artificially further cooled, until all the mass forms a stiff jelly. This is next
washed in cold water to eliminate all soluble salts redissolved and filtered. To
prepare the film, good plain smooth paper is chosen, and as preliminary preparation,
it is advisable to coat it with solution of plain gelatine, or submit it to the
preparation usually adopted for enamelling only, using larger proportion of gelatine
in the enamelling paste. Such prepared paper must be covered with coating of
sensitive emulsion, which can be done either by floating the prepared side of the
paper on the sensitive emulsion warmed to the temperature of 35° by hand, or by
mechanical appliances, or by bending the edges of the paper to form a tray; the
emulsion is poured in the so formed tray, and evenly distributed by rocking it.
After the first coating is dry, a second coating (if necessary) is made in similar
manner. Sheets of paper prepared as above, which I term sensitive tissue, can be
preserved in dark and dry atmosphere indefinitely. Other colloidals may be used
instead of or in connection with gelatine in the emulsion. The luminous image is
projected on the sensitive tissue either in the camera or otherwise, and after
suitable exposure, the tissue is immersed in developing liquid, for which two
solutions are necessary; (1) pyrogalol, 15 parts; citric acid, 4; glycerine, 12;
alcohol, 25; (2) ammonium bromide, 1; liquid ammonia (880 s. g.) 10; glycerine,
15; water, 15; 10 drops of each No. 1 and No. 2 are added to 30 cen. cube of
water to form the developer. The tissue is left in it until the image is fully
developed. It is afterwards washed with water, fixed with hyposulphite of soda
(or not fixed) and dried. The sensitive tissue with developed image on it is now
put in contact with plain or suitably prepared glass, paper, or other surface
(according to the destination of the image), and plunged into warm water or other
liquid, though the action of parts not affected by light and developer will be
dissolved, while the image consisting of insoluble parts only remains attached to
the surface on which it was devoloped. In the above described manipulations,
care must be taken to avoid any influence that can produce general insolubility of
the film, such as the use of gelatine, soluble only with difficulty, action of acids in
the formation of emulsion or in drying, addition of alum, etc. This process can be
applied; (1) to the production of negatives, transparent positives, reproduced and
enlarged negatives. The advantages secured are absence of blurring, freedom from

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solarization, greater range of exposure, possibility of intensification with silver and
pyrogalol or iron, without risk of staining the film. Naturally the image obtained
is reversed compared with the ordinary process, but by using transfer paper or by
removing the film by means of collodion or gelatine in sheets or in solution this
inconvenience is avoided. (2.) For production of photographic image same size
or enlarged on paper, canvas, or any other surface, the mode of proceeding is the
following The paper is preferably rendered impervious with insoluble gelatine or
varnish. The sensitive tissue with developed image is put under water in contact
with any of the above mentioned surfaces, and developed in warm water. For
many purposes the image so obtained is quite suitable, but if desired, it can be
obtained in any color; for this purpose the coloring media insoluble, and having
no action on any of the component parts of emulsion or developer is added to the
emulsion, and in the resulting image this colouring substance will give the hue of
the color. (3.) For the production of relief clichées, such as used for "Woodbury
process, photoreliefs, or photoengravings. For all such purposes, the sensitive
tissue must be prepared so as to give sufficient relief necessary for above mentioned
processes, and this is attained by increasing the thickness of the emulsion film,
which is thereby less opaque. For the intaglio cliché, artificial grain is produced
by the addition of suitable inert powder of varying coarseness, such as emery,
glass, or sand to the emulsion. (4) For photoceramic, vitrified color. in this case
is added to the emulsion, which itself is made of the nature, producing only a
phantom image. (5.) For the phototype process, the image produced as above on
the glass is covered with thick coating of plain gelatine; when dry and peeled off
it will be found that the surface which was next to the glass, if treated as usually
in phototype process, inked with suitablo roller and ink, will give the impression
in printer's ink. (6.) For obtaining photographic transparent images in color,
The image developed on plain glass, if treated with soluble coloring media direct,
or by double decomposition, will assume respective color forming the image,
suitable for magic lantern or other ornamentation.
Having now particularly described and ascertained the nature of my Invention,
and in what manner the same is to be performed, I claim the Invention of
<<
"Improvements in and Applicable to Photography," substantially as herein
before described, in which the special point or feature principally consists in
removing by solution the parts of colloidal body in which silver is not precipitated
by the agency combined of light and developer, and by applying solvents to the
side of the film opposite to the surface on which the light has acted.
In witness whereof, I, the said Leon Warnerke, have hereunto set my hand
and seal this Twenty fourth day of September, in the year of our Lord One
thousand eight hundred and eighty one.