Improvements in Photography and connected with the Operations of Developing and Fixing.
Year: 1899

page_text: Date of Application, 26th Aug.,
1899
Complete Specification Left, 27th Apr., 1900--Accepted, 2nd June, 1900
PROVISIONAL SPECIFICATION.
Improvements in Photography and connected with the Operations of
Developing and Fixing.
We, JOHN EDWARD THORNTON, of Rokeby, Oldfield Road, Altrincham, Cheshire,
Manufacturer, and CHARLES FREDERICK SEYMOUR ROTHWELL, of Worsley Mills,
Worsley Street, Hulme, Manchester, Lancashire, Chemist, do hereby declare the
nature of this invention to be as follows:-
The object of this invention is to dispense with bottles of chemical solutions for
developing and fixing photographic images, also with the usual dark room, and
to provide substitutes which shall be more convenient.
In carrying out our invention we make up the developer, or a combined developer
and fixer, in such a form that it accompanies each sensitive plate or film (herein-
after termed plate,) so that by the addition of the necessary quantity of water
sufficient active solution is formed for each plate separately at the time of develop-
ment.
We are aware that it has already been proposed to attach the developer to the
back of each plate, by incorporating it with a soluble cement or coating such as
gum, which would dissolve upon immersion of the plate in water and so form the
developing solution.
The operation of fixing the plate after development has, however, always been
accomplished by immersing it in a separate solution prepared in the usual liquid
form.
Under this invention we propose to incorporate the fixing medium with the
developer, so that when water is added the mixture effects the two functions of
developing and fixing the image. The effect of this combination is a great
improvement upon what has hitherto been done, because it not only dispenses
entirely with all chemical solutions in bottles (a great advantage to travellers),
but it also renders a dark room entirely unnecessary, as the plate can pass from
the camera after exposure direct into a trough or tank in which it is both developed
and fixed. By making this tank of red, yellow, or other non-actinic glass or
transparent celluloid. the progress of development and fixing can be easily seen
and the plate removed when desired. It is, however, not essential to watch the
progress, as by combining the fixing with the developing operation no serious
result will happen to the picture should the plate be left in the tank rather too
Jong.
By our invention it is possible to remove the plate from the tank in day-
light as soon as developed, whereas this was not possible hitherto because if the
plate was removed from the developing tank to a separate fixing tank in daylight,
the image became fogged by the light during transferrence from one tank to the
other, and all devices hitherto proposed in which the two tanks were enclosed from
daylight by some box or covering chamber other than a dark room were unsatis-
factory, and accidental mixing of the solutions frequently occurred and spoiled
the image.
After the plates have been developed and fixed outdoors or away from home,
we prefer to leave the necessary operations of washing to free the plate from

page_text: all traces of developer, until the operator returns home. In order to facilitate
this and prevent any injury to the plates in the meantime, we provide a grooved
box or equivalent device into which the wet plates can be placed without touching
each other. The box is closed by a lid or door, may afterwards be used as a
washing tank without removing the plates therefrom.
When the developer has been attached to the back of the plate hitherto it has
proved a complete failure, the chief reason for which being that the developing
preparation was liable to damage the face of the plate behind when used in
magazines and other cases where a number of plates were placed in a pack.
This objection is overcome by our invention because we seal and protect the
developer by one of the following or other convenient arrangements. (1) The
developer, (which term herein also includes the fixer) may be applied to the back
of the plate and then covered by a sheet of paper or a sheath. Or the developer
may likewise be attached to the sheath or the covering paper. Or if the plates are
enclosed in envelopes of paper or like material, the developer may be placed in
a small pocket or nick formed in the envelope itself.
To develop, the paper-covered plate may be immersed complete in the water,
which dissolves the developer and softens the paper permitting the latter to be
removed or thrown away.
We are aware that the idea of using a combined developing and fixing solution
is not new, and we make no claim to such a process. The point of our invention
is the incorporation of the developer and fixer in some dry form, attached to or
supplied with, each separate plate as already described, which dispenses with
bottles of chemical solutions, and which further allows development to be carried
on in daylight, and outdoors at the scene of operations if desired, all without a
dark room or cumbersome cases or devices containing separate solutions in separate
tanks.
We believe that our invention constitutes a considerable improvement or new
step in the art of photography, and that it will do much to simplify the present
troublesome operations. It will reduce the time occupied therein, and enable
the operator to ascertain the results of his exposures on the spot without waiting
till he return home, or carrying about cumbersome developing apparatus, and
further dispenses with all weighty measuring, and mixing of chemicals. As a
consequence it will increase public interest in the art and lead to a more extensive
practise of it.
The following may be taken as examples of suitable preparations. They may
be made up in the form of a strong solution, with sugar or dextrine, and then
applied in the form of a coating to the plates, papers, sheaths, or envelopes as
already described, using enough to give about the following proportions to each
plate, of quarter plate size.
DEVELOPER FOR ONE QUARTER PLATE.
Pyro 2 grains (or hydroquinone 3 grains) (or metol 2 grains and hydroquinone
2 grains)
Carbonate soda anhydrous 10 grains
Sulphite soda anhydrous 10 grains
Potassium bromide grain,
COMBINED DEVELOPER AND FIXER FOR ONE QUARTER PLATE.
15 grains anhydrous sulphite soda
9 grains powdered caustic soda
20 grains anhydrous hyposulphite soda grind together and add
9 grains kachin or pyrocatechine.
Dated this 25th day of August 1899.

page_text: Improvements in Photography and connected with the Operations of
Devoloping and Fixing.
We, JOHN EDWARD THORNTON, of Rokeby, Oldfield Road, Altrincham, Cheshire,
Manufacturer, and CHARLES FREDERICK SEYMOUR ROTHWELL, of Worsley Mills,
Worsley Street, Hulme, Manchester, Lancashire, Chemist, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement: -
This invention relates to photographic plates and films prepared for use in
photographic cameras for taking camera pictures.
The object of the invention is to dispense with bottles of chemical solutions for
developing and fixing photographic images, also with the usual dark room, and
to provide substitutes which shall be more convenient.
Hitherto in the developing and fixing of photographic negatives, after removal
from the camera, it has been the almost universal custom to prepare two chemical
solutions and immerse the plate or film first in one and then in the other, in a
dark room from which the actinic rays of light have been excluded.
We are aware however that it has already been proposed to apply to the back
of each plate or film the developer. by incorporating it with a cement or coating,
such as gum soluble in water, which upon the immersion of the plate or film in
water dissolves, forming the developing solution.
I
The operation of fixing after development has however hitherto been always
accomplished by immersing it in a separate solution carried in a liquid form.
When the developer has been attached to the back of the plate hitherto it has
proved a failure, the chief reason for which, being that the developing preparation
was liable to damage the face of the adjacent plate, when used in magazines
and other cases where a number of plates were placed in a pack, and also, the
developer deteriorated by contact with the air.
The invention consists in preparing each sensitive plate or film (hereinafter
called plate), with a developer or combined developer and fixer annlied thereto in
suitable dry form and protected by an air tight covering, so that by immersion
in the necessary quantity of water an active solution is formed at the time of
development, separately for each plate, sufficient for developing and fixing the
negative.
In carrying out the invention we incorporate the developer and the fixing
medium so that when dissolved in water a solution is prepared which effects the
double functions of developing and fixing the image. Although we prefer the
developing and fixing medium mixed or incorporated, and .then applied to the
plate, the developing medium only may be so applied.
Any suitable developing or developing and fixing mediums may be employed
which can be put up and packed with the plates in dry form. The following
may be taken as examples of suitable preparations, the proportions being enough
for each plate of quarter plate size.
DEVELOPER.
Pyro 2 grains (or hydroquinone 3 grains) (or metol 2 grains and hydroquinone

page_text: COMBINED DEVELOPER AND FIXER.
15 grains anhydrous sulphite soda
9 grains powdered caustic soda
20 grains anhydrous hyposulphite soda grind together and add
9 grains kachin or pyrocatechine
The developing and fixing medium is made up in the form of a strong solution
with sugar or dextrine, and then applied in one of the following ways.
(a) The plate is coated on the back with the solution and after the latter is
dry, over this is placed a sheet of air tight material such as paper, soluble gelatine,
or other material which will prevent the action of the air upon the developing
medium, and will prevent it coming into contact with adjacent plates, and which
will readily separate or dissolve on immersion in water.
-
(b) The prepared solution may be coated upon a paper backing sheath, or
envelope, which covers or protects the plate and which at the same time serves
as an air tight protection for the developing and fixing medium as applied to
rolls, the covering material may be attached to the back of the sensitive film, or
a loose paper backing may be wound up with the film and removed or discarded
when the film is cut up into plates.
The effect of the combination of the developing and fixing medium is a great
improvement upon what has hitherto been done, because it not only dispenses
entirely with all chemical solutions in bottles (a great advantage to travellers),
but it also renders a dark room entirely unnecessary, as the plate can pass from
the camera after exposure direct into a trough or tank in which it is both
developed and fixed. By making this tank of red. yellow, or other non-actinic
glass or transparent celluloid the progress of development and fixing can be easily
seen and the plate removed when desired. It is however not essential to watch
the progress, as by combining the fixing with the developing operation no serious
result will happen to the picture should the plate be left in the tank rather too
long.
By our invention it becomes possible to remove the plate from the tank in day-
light as soon as developed, whereas this was not possible hitherto because if the
plate was removed from the developing tank to a separate fixing tank in daylight,
the image became fogged by the light during transference from one tank to the
other, and all devices hitherto proposed in which the two tanks were enclosed from
daylight by some box or covering chamber other than a dark room were unsatis-
factory, as accidental mixing of the solutions frequently occurred and spoiled
the image.
After the plates have been developed and fixed outdoors or away from home
we prefer to leave the necessary operations of washing to free the plate from all
traces of chemicals until the operator returns home. In order to facilitate this
and prevent any injury to the plates in the meantime a grooved box or equivalent
device may be employed into which the wet plates can be placed without touching
each other. The box is closed by a lid or door, and may afterwards be used as a
washing tank without removing the plates therefrom.
This invention further overcomes the objection hitherto experienced when the
developer has been applied to the back of the plate, of damaging the sensitive
surface of an adjacent plate by reason of the developing or developing and fixing
medium being protected by an airtight cover.
To develop, the covered plate may be immersed complete in the water, which
dissolves the developer and softens the covering permitting the latter to be
removed or thrown away.
We are aware that the idea of using a combined developing and fixing solution
is not new, and we make no claim to such a process. The point of our invention
is the incorporation of the developer and fixer in some dry form attached to, or
supplied with, each separate plate as already described which dispenses with
bottles of chemical solutions, and which further allows development to be carried

page_text: on in daylight, and outdoors at the scene of operations if desired, all without a
dark room or cumbersome cases or devices containing separate solutions in separate
tanks.
We believe that our invention constitutes a considerable improvement or new
step in the art of photography, and that it will do much to simplify the present
troublesome operations. It will reduce the time occupied therein, and enable
the operator to ascertain the results of his exposures on the spot without waiting
till he returns home, or carrying cumbersome developing apparatus, and further
dispenses with all troublesome measuring and mixing of chemicals.
consequence it will increase public interest in the art and lead to a more extensive
practise of it.
As a
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. A photographic plate or film for use in a camera prepared with a developing
and fixing medium attached thereto substantially as described.
2. A photographic plate or film for use in a camera provided with a developing
or developing and fixing medium applied thereto in such quantity as to form a
solution sufficient for one plate or film and enclosed or covered by an air tight
covering which serves to protect the medium from the action of the air and to
protect adjacent plates from the action of such medium substantially as described.
3. Photographic plates or films for use in a camera prepared substantially as
described.
new
1
e
1000
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester,
Patent Agents.