Improvements relating to the Preparation of Photographic Sensitized Surfaces.
Year: 1899

page_text: Date of Application, 10th Mar., 1899
Complete Specification Left. 11th Dec.. 1899-Accepted. 27th Jan. 1900
PROVISIONAL SPECIFICATION.
Improvements relating to the Preparation of Photographic Sensitized
Surfaces.
I, LOUIS HANRIAU, of 10, Gaillon, Paris, in the Republic of France, Photo-
grapher, do hereby declare the nature of this invention to be as follows:-
This invention relates to the preparation of paper or other photographic sur-
faces by means of platinum or other metals.
My process consists in producing upon suitable surfaces, such as paper, wood,
silk and so forth, photographic images by means of a double salt of platinum,
gold, palladium, irridium and other metals, by adding thereto a solution of
ferrous sodium oxalate.
I prepare the following solutions, for platinum for example.
Solution A Ferrous sodium oxalate to saturation for an ordinary temper-
ature of 15 to 20 degrees.
Solution B: Protochloride of platinum to saturation.
For the other metals I replace the protochloride of platinum by a proto-
chloride of one of the other metals enumerated above.
In order to prepare my paper, I take equal parts of solutions A and B and I
coat the paper or other support with a uniform layer of the mixture by means
of a brush which is kept scrupulously clean. The paper or other medium is
afterwards dried and is then ready for use.
This paper is exposed to the light beneath the negative the image of which
it is desired to reproduce, in the ordinary manner. When the image has made
its appearance I take the paper or other medium from beneath the negative
and pass it directly through various baths consisting of water and hydrochloric
acid at 1%, the print being then thoroughly washed in water for one hour.
It is then only necessary to dry the print and mount it upon a card or other
suitable support.
It will of course be understood that I may vary, within certain limits, the
proportions of the chemical substances employed for carrying out the process
above described, according to the results which it is desired to obtain.
The great advantage of the paper, the manufacture of which has been de-
scribed, over all other photographic papers, is that it requires neither develop-
ment nor toning: it is printed to its exact value and the appearance of the image
may be readily watched, care being taken, in order to preserve all the brilliancy
of the paper, to change and examine it only in a very subdued light, preferably
yellow. As regards duration, its life is equal to that of the support itself.
Dated this 10th day of March 1899
HASELTINE, LAKE & Co..
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: Improvements relating to the Preparation of Photographic Sensitized
Surfaces.
I, LOUIS HANRIAU, of 10, Rue Gaillon, Paris, in the Republic of France,
Photographer, do hereby declare the nature of this invention and in what man-
ner the same is to be performed, to be particularly described and ascertained
in and by the following statement:
"
This invention relates to the preparation of paper or other photographic sur-
faces by means of platinum or other metals, and consists in producing upon
suitable surfaces, such as paper, wood, silk and the like, photographic images
by means of a double salt of platinum, gold, palladium, irridium and other
metals, by adding thereto a solution of ferrous sodium oxalate.
In carrying my invention into effect I prepare (for platinum prints for ex-
ample) the following solutions.
1: A saturated solution of ferrous sodium oxalate for an ordinary temper-
ature of 15 to 20 degrees.
2: A saturated solution of protochloride of platinum.
For other metals I replace the protochloride of platinum by a protochloride
of one of the other metals enumerated above.
In order to prepare my paper or other photographic surfaces, I take equal
parts of solutions 1 and 2 and coat the paper or other support with a uniform
layer of the mixture, by means of a brush which must be kept scrupulously
clean. The prepared paper or other medium is afterwards dried and is then
ready for use.
When producing prints by this process, the prepared paper is exposed to the
light beneath the negative in the usual way. When the image has made its
appearance the paper or other medium is removed from beneath the negative
and passed directly through various baths consisting of water containing 1%
of hydrochloric acid, the print being then thoroughly washed in water for one
hour.
It is then only necessary to dry the print and mount it upon a card or other
suitable support.
It will of course be understood that I may vary, within certain limits, the pro-
portions of the chemical substances employed for carrying out the process above
described, according to the results which it is desired to obtain.
The great advantages of the paper, manufactured in accordance with my in-
vention over all other photographic papers, is, that it requires neither develop-
ment nor toning; it is printed to its exact density, and the appearance of the
image may be readily watched, care being taken however, in order to preserve
all the brilliancy of the paper, to change and examine it only in a very subdued
light, preferably yellow. As regards duration, its life is equal to that of the
support itself.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, declare that what
I claim is:
-
1. The process above described for obtaining photographic prints by means
of the double salts of platinum, or of one of the metals specified above, mixed
with ferrous sodium oxalate, these prints or positives being obtained by direct..
printing without developing or toning.

page_text: 2. As a new product, the paper or other substance for photographic purposes
prepared with platinum or other suitable metal substantially as herein before
described.
Dated this 11th day of December 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.