Improvements relating to the Development of Photographic Pictures.
Year: 1893

page_text: Date of Application, 29th Dec., 1893
Complete Specification Left, 17th Sept., 1894--Accepted, 27th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements relating to the Development of Photographic
Pictures.
I, MOMME ANDRESEN, of 44 Melchiorstrasse, Berlin, Germany, Chemist, do
hereby declare the nature of this invention to be as follows:-
The invention relates to improvements in the development of photographic
pictures by means of naphthaline derivatives.
In the Specification No. 5207 of 1889 is described a process for developing
photographic images. At the date of that Patent certain substances belonging or
related to the groups of naphthaline derivatives referred to in the said Specification
were not known.
The present invention relates to the application for developing, of the following
substances which I have found useful developers.
1. a-amido-ẞ naphthol monosulpho acid (Journ. pr. Chem. N. F. B. 44 S 521 ff).
2. a-amido- naphtholdisulpho acid, prepared by the reaction of sulphurous acid
on the nitroso compound of the ẞ naphthol monosulpho acid, Schaeffer.
3. a-amido-ẞ, naphtholdisulpho acid prepared by the reaction of sulphurous acid
on the nitroso compound of the B-naphthol-3-monosulpho acid F.
4.a-amido-B-naphthol carbo-sulpho-acid prepared by the reaction of sulphurous
acid on the nitroso compound of the B-oxy-naphthoic acid (melting point 216°).
The process of developing with the above substances is analogous to that
described in the Specification above referred to.
Dated this 29th day of December 1893.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Development of Photographic
Pictures.
I, MOMME ANDRESEN, of 44 Melchoirstrasse, Berlin, Germany, 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:-
The invention relates to improvements in the development of photographic
pictures by means of naphthaline derivatives.
In the Specification No. 5207 of 1889 is described a process for developing
photographic images. At the date of that Patent certain substances, belonging or
related to the groups of naphthaline derivatives referred to in the said Specification,
were not known.
The present invention relates to the application for developing of the following
substances which I have found useful developers.
1. a-amido-ß naphthol-monosulpho acid, more correctly named a₁-amido-ẞ,
naphthol-a, monosulpho acid, (Journ. pr. Chem. N. F. B. 44 S 521 ff).
2. a-amido-naphthol disulpho acid more correctly named a,-amido-ẞ₁
naphthol-a, B disulpho acid, prepared by the reaction of sulphurous acid on the
nitroso compound of the ẞ naphthol mono sulpho acid, Schaeffer.

page_text: The acid is obtained in the shape of fine white crystalline needles, easily soluble.
in water, insoluble in alcohol, and sparingly soluble in concentrated hydrochloric
acid.
The alkali salts are very soluble in water, their solution turns brown after
exposure for some time in the open air.
The acid solution turns yellow on addition of ferrichloride.
3. amido-naphthol disulpho acid more correctly named amido-ẞ,
naphthol-a, B, disulpho acid, prepared by the reaction of sulphurous acid on the
nitroso compound of the Bi-naphthol-ẞ-monosulpho acid.
The acid crystallises in the shape of fine white needles, easily soluble in water,
insoluble in alcohol, and very sparingly soluble in acid solution. The alkali salts
are very soluble in water, and their solutions become yellow lirown in the open air.
The acid solution turns yellow on addition of ferrichloride.
4. amido--naphthol-carbo-sulpho acid more correctly named a-amido--
naphthol-3-carbo-a, sulpho acid, preparel by the reaction of sulphurous acid
on the nitroso compound of the ẞ-oxy-naphthoïc acid having melting point 2160.
This acid is obtained in the shape of white crystalline needles, sparingly soluble
in water, insoluble in alcohol. The alkali salts are soluble in water, and their
solutions become brown after exposure for some time in the open air,
The acid solution turns yellow on addition of ferrichloride.
The process of developing with any of the four substances mentioned is analogous
to that described in the Specification above referred to.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is :-
The herein described process for developing photographic pictures on coatings of
silver chloride, bromide or iodide or any mixtures thereof, by treating these
coatings in a developing bath containing any of the four substances hereinbefore
mentioned.
Dated this 17th day of September 1894.
ABEL & IMRAY,
Agents for the Applicant.