Improved Process for Intensifying Photographic Silver Prints.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improved Process for Intensifying Photographic Silver Prints.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent,
do hereby declare the nature of this invention (as communicated to me from
abroad by Actien Gesellschaft für Anilin-Fabrikation, of Berlin, in the Empire
of Germany, Chemical Manufacturers), and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
It has been already shewn that the solutions of certain double salts of mer-
curic thiocyanate and the thiocyanates of the alkalies, alkaline earths or of
ammonia can be used for intensifying photographic silver prints.
My correspondents have now found that instead of the said double salts with
alkali thiocyanates there can also be used for the same purpose double salts
of mercuric thiocyanate with alkali chlorides, or mixtures of the double salts
above mentioned and those obtained with alkali chlorides. These double salts
or the mixtures thereof are applied in exactly the same manner as the double
salts with alkali thiocyanates previously described.
The invention is illustrated by the following examples.
1. 10 parts of mercuric thiocyanate and 10 parts of sodium chloride are dis-
solved in 50 parts of water.
For use as intensifier one part of this stock solution is diluted with 10 parts
of water.
2. 10 parts of the double salt of mercuric thiocyanate and potassium thiocyanate
and 6 parts of sodium chloride are dissolved in 50 parts of water.
For use as intensifier one part of this stock solution is diluted with 10 parts
of water.
The proportions indicated for the constituents in the above examples are not
exactly those calculated for the formation of the double salts from equimolecular
proportions of mercuric thiocyanate and the chlorides or thiocyanate of alkalies,
since an excess of the alkali salt has been found suitable as the mixtures so
obtained are more easily soluble in water and more stable in aqueous solution
than are the pure double salts.
111 07th day of May 1899
ABEL & IMRAY,
Agents for the Applicant.
Improved Process for Intensifying Photographic Silver Prints.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent,
Price S1

page_text: do hereby declare the nature of this invention (as communicated to me from
abroad by Actien Gesellschaft für Anilin-Fabrikation, of Berlin, in the Empire
of Germany, Chemical Manufacturers), and in what manner to same is to be
performed, to be particularly described and ascertained in and by the following
statement;-
―:
It has been already shewn that the solutions of certain double salts of mer-
curic thiocyanate and the thiocyanates of the alkalies, alkaline earths or of
ammonia can be used for intensifying photographic silver prints.
My correspondents have now found that instead of the said double salts with
alkali thiocyanates there can also be used for the same purpose double salts
of mercuric thiocyanate with alkali chlorides, or mixtures of the double salts
above mentioned and those obtained with alkali chlorides. These double salts
or the mixtures thereof are applied in exactly the same manner as the double
salts with alkali thiocyanates previously described..
The invention is illustrated by the following examples.
1. 10 parts of mercuric thiocyanate and 10 parts of sodium chloride are dis-
solved in 50 parts of water.
For use as intensifier one part of this stock solution is diluted with. 10 parts
of water.
2. 10 parts of the double salt of mercuric thiocyanate and potassium thiocyanate
and 6 parts of sodium chloride are dissolved in 50 parts of water.
For use as intensifier one part of this stock solution is diluted with 10 parts
of water.
The proportions indicated for the constituents in the above examples are not
exactly those calculated for the formation of the double salts from equimolecular
proportions of mercuric thiocyanate and the chlorides or thiocyanate of alkalies,
since an excess of the alkali salt has been found suitable as the mixtures so
obtained are more easily soluble in water and more stable in aqueous solution
than are the pure double salts.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
The herein described improved process for intensifying photographic silver-
prints by subjecting them to the action of a solution containing.
1. A double salt of mercuric thiocyanate with a chloride of an alkali, an alkaline
earth or ammonia, or
2. A mixture of the double salts obtained from mercuric thiocyanate with a
chloride and with a thiocyanate of an alkali, an alkaline earth or ammonia, in
both cases with an excess of the alkali salts employed.
Dated this 2nd day of February 1900
ABEL & IMRAY,
Agents for the Applicant.