Year: 1887

page_text: Date of Application, 2nd Feb., 1887
Complete Left, 2nd Nov,, 1887
Complete Accepted, 2nd Dec., 1887
Hereby ucciate one
My invention has for its object the production upon paper or other surfaces of
photographic pictures or images in platinum; it differs from the processes of
photo-chemical printing described in the Specifications of my former patents
viz. No. 2011 dated June 5th, 1873, No. 2800 dated July 12, 1878 and No. 1117
dated March 15, 1880, in which processes (as far as they relate to platinumn) the
paper or other surface was coated with a solution of a salt of platinum and
sometimes other salts and also with a solution of ferric oxalate. These solutions
were applied, either separately or mixed, to the paper, but in all cases the sensitive
After
coating of the, paper contained a salt of platinum and ferric oxalate.
exposure to light the prepared surfaces were treated with one
developing solutions described in the said.specifications.
or other of the
Hitherto no means have been known by which the salt of platinum could be
employed entirely in the developer instead of wholly or partly in the sensitive
coating of the paper, but I have now discovered that by the use of developers
containing salts of platinum and certain soluble phosphates (or other salts in which
the ferrous oxalate image produced by exposure to light is insoluble or nearly so),
with or without the addition of other salts (such as potassic oxalate, potassic tartrate,
ammonic citrate) which tend to increase the rapidity and vigour of the developement,
I can avoid the necessity of using salts of platinum in the sensitive coating of the
paper. I thereby diminish the cost of the process and avoid the necessity of heating
the developer
According to my present invention I use paper or other material with its surface
prepared and rendered sensitive for photographic purposes by the application of a
coating containing ferric oxalate with or without the addition of a salt of lead or of
mercury, and without any salt of platinum.
I first prepare the paper or other surface by the use of this coating as hereinafter
specified then expose it to light under or behind a negative and then develop the
picture by means of one of my improved solutions or other suitable developers.

page_text: For preparing or coating the paper or other material I prefer to employ for
ordinary purposes an aqueous solution of ferric oxalate containing in each fluid ounce
about sixty (60) grains of ferric oxalate (Fe, (C₂ O4)3) but may use less or more of
the latter according to the result desired to be obtained. I sometimes mix with or
dissolve in the ferric oxalate a salt of mercury or of lead, for instance I may dissolve
in one fluid ounce of the ferric oxalate solution, above described, one grain or more
of mercuric chloride. I find this mercuric salt very useful where a warm or sepia
tone is desired.
The paper thus coated, after being dried is ready for use. After its exposure to
light under or behind a negative I apply to it the developing solution.
I prepare an improved developing solution or developer as follows, that is to say, I
use various soluble phosphates. I prefer the monosodic or disodic, the mono-potassic
or dipotassic or the mono-ammonic or diammonic orthophosphates or mixtures or
combinations of these salts with one another and with or without the addition of other
salts such as potassic oxalate, ammonic citrate and others. In all cases I add to these
solutions or mixtures of "solutions a platinous salt I mix a solution of this salt with
the above mentioned solutions or I dissolve the platinous salt in them. The platinous
salts I prefer to make use of are the ammonic, potassic and sodic chloro-platinites the
ammonic potassic, and sodic bromo-platinites or mixtures of them and in some
cases I use a very small quantity of a platinic salt such as ammonic potassic or
sodic chloro-platinate. prepare this developing solution as follows, that is to say;
I dissolve in one fluid ounce of water one hundred (100) grains of di-potassic ortho-
phosphate forty (40) grains of potassic oxalate and ten (10) grains of potassic chloro
platinite or I may make it in another manner viz.: by dissolving in one fluid ounce of
water one hundred (100) grains of di-ammonic ortho-phosphate thirty-five (35) grains
of ammonic citrate and ten (10) grains of ammonic chloro platinite or I make similar
developing solutions with the salts previously mentioned I also make developers
containing only phosphates and salts of platinum that is to say; I may make a
developer by dissolving in one ounce of water about one hundred (100) grains of
mono-potassic or di-potassic ortho-phosphate or mixtures of these salts and ten (10)
grains of potassic chloro-platinite.
This solution may be applied to the paper or other surface by pouring it over the
same or by immersing the paper therein, or by floating the paper thereon. It may
be applied cold, warm, or hot as desired. A cold solution usually takes longer to
effect the development of the picture than a hot one. The strength of the solution
may be varied; usually the best results are obtained by strong solutions of the
phosphates and other salts, but the platinum salt need not usually be present in a
greater quantity than ten grains of the salt to one fluid ounce of the developer.
Dated this 2nd day of February 1887
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.

page_text: I, WILLIAM WILLIS, of Bromley, in the County of Kent, Manufacturer, 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
My invention has for its object the production, upon paper or other surfaces, of
photographic pictures or images in platinum, that is to say, pictures or images of
which the colouring matter or pigment is platinum. It differs from the processes of
photo-chemical printing described in the specifications of iny former patents, viz. :-
No. 2011 dated June 5th 1873, No. 2800 dated July 12th 1878, and No. 1117 dated
March 15th 1880, in which processes (as far as they relate to platinum) the paper or
other surface is coated with a solution of a salt of platinum and sometimes other salts
and also with a solution of ferric oxalate. These solutions are applied, either separately
or mixed, to the paper, and in all cases the sensitive coating of the paper contains
a salt of platinum and ferric oxalate. After exposure to light, the prepared
surfaces are treated with one or other of the developing solutions described in the
said Specifications.
Hitherto no means have been known by which the salt of platinum could be
employed entirely in the developer or developing solution, instead of wholly or partly
in the sensitive coating of the paper or other surface as above set forth.
I have,
however, now discovered a process by which I can accomplish this result. For this
purpose I apply to paper or other suitable material which has been rendered sensitive
by a coating of ferric oxalate and afterwards exposed to light, a developer containing
salts of platinum and certain soluble phosphates (or other salts, in which the ferrous
oxalate image produced by exposure to light is insoluble or nearly so), with or
without the addition of potassic oxalate, potassic tartrate, ammonic citrate or other
salts which tend to increase the rapidity and vigour of the development. By this
process I avoid the necessity of using salts of platinum in the sensitive coating of the
paper or other surface. I thereby greatly diminish the cost of the process and can
obtain good results without heating the developer.
Moreover I obtain a slower developing action so that it is possible to watch the
progress of development and to arrest it at any desired moment by washing the print
in a solution of acid.
According to my present invention I use paper, wood, woven fabric or other
material the surface of which I prepare and render sensitive for photographic
purposes by the application of a coating or coatings containing ferric oxalate with (or
without) the addition of a salt of lead or of mercury, or mixtures thereof, and without
any salt of platinum.
I first prepare the paper or other surface by the use of this coating as hereinafter

page_text: specified. I then expose it to light under or behind a negative and then develop the
picture by means of one of my improved developing solutions hereinafter specified, or
other suitable solution containing a salt of platinum.
For preparing or coating the paper or other material, I employ for ordinary
purposes an aqueous solution of ferric oxalate containing in each fluid ounce about
sixty (60) grains of ferric oxalate Fe, (C₂ O₁); but I may use less or more of the
latter according to the result desired to be obtained. I am of course aware that there
are other salts of iron sensitive to light, but the oxalate is the. best for my purpose.
I sometimes mix or dissolve in the ferric oxalate a salt of mercury or of lead or a
mixture of these salts: for instance, I dissolve in one fluid ounce of the ferric oxalate
solution above described, from one grain to three grains of mercuric chloride. Or I
apply solutions of a salt of lead or mercury or a mixture of these salts to the paper or
other surface either previously or subsequently to coating the same with ferric
oxalate. I find the mercuric salt very useful where a warm tone or effect somewhat
resembling that of sepia is desired.
I do not confine niyself to aqueous solutions of the above named salts.
The paper thus coated, after being dried, is ready for use. If two coatings are
applied to the paper or other surface; it should be dried between the application of
the first and second coatings. After its exposure to light under or behind a negative,
I apply to it the developing solution.
I prepare an improved developing solution or developer as follows, that is to say:
I use solutions of various soluble phosphates. I have been most successful with the
following, viz. the monosodic or disodic, the monopotassic or dipotassic or tho
mono-ammonic or diammonic orthophosphates, or mixtures or combinations of these
salts with one another, and with or without the addition of other salts such as
potassic oxalate, ammonic citrate and others. In all cases I add to these solutions or
mixtures of solutions a salt of platinum. I mix a solution of this salt with the above
named solutions or I dissolve the platinum salt in them. The platinous salts most
suitable for my purpose are the ammonic, potassic and sodic chloro-platinites, the
ammonic, potassic and sodic bromo-platinites or mixtures of them, and in some
cases I use a very small quantity of a platinic salt, such as ammonic, potassic or
sodic chloro-platinate.
I usually prepare this developing solution as follows, that is to say I dissolve in
one fluid ounce of water, one hundred (100) grains of di-potassic orthophosphate,
forty (40) grains of potassic oxalate and ten (10) grains of potassic chloro-platinite ;
or I may make it in another manner, viz: by dissolving in one fluid ounce of water,
one hundred (100) grains of diammonic orthophosphate, thirty five (35) grains of
ammonic citrate and ten (10) grains of ammonic chloro-platinite; or I make similar
developing solutions with the salts previously mentioned. I make also developers
containing only phosphates and salts of platinum, that is to say, I may make a
developer by dissolving in one ounce of water, about one hundred (100) grains of
miono-potassic or di-potassic orthophosphate or mixtures of these salts and ten (10)
grains of potassic chloro-platinite.
The developing solution is applied to the paper or other surface (after the same has
been exposed to light) by pouring it over the same, or by immersing the paper
therein, or by floating the paper thereon, or by means of a brush or otherwise. It is
applied cold, warm or hot as desired. A cold solution usually takes longer to effect
the development of the picture than a hot one. The strength of the solution may be
varied,; usually the best results are obtained by strong solutions of the phosphates
and other salts; the platinum salt will ordinarily be used in the proportion of from
five to ten grains of the salt to one fluid ounce of the developer.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I wish it understood that I
claim―
First. The process or method in which I sensitize the surface of paper or other
material by the means herein, specified then axpose the surface to light and then

page_text: develop the picture or image by the use of a solution containing a salt of platinum,
as above set forth.
Second. The production or development of photographic pictures or images in
platinum by the application of a salt of this metal to a surface which has been
previously rendered sensitive by the application of a ferric salt and exposed to
light.
Third. Paper or other material which has its surface prepared and rendered sensitive
for photographic purposes by the application of a ferric salt and a salt of mercury or
of lead or of both mercury and lead as above set forth.
Dated this 2nd day of November 1887.
W. WILLIS.
Haseltine, Lake & Co,,
45, Southampton Buildings, London,
Agents for the Applicant.