Improvements in the Manufacture of Photographic Plates.
Year: 1894

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Photographic Plates.
I, OTTO MAGERSTEDT, of No. 183 Reichenbergerstrasse, Berlin, in the German
Empire, Merchant, do hereby declare the nature of this invention to be as follows:-
This invention relates to certain improvements in the production of photographic
plates, connected with the invention described in my previous Specification No. 5932
of 1893. In this Specification is described a treatment of plates by which the defects
of halation and solarisation are avoided, by placing a coloured layer between the
layer of haloid silver emulsion and the material carrying it.
For the production of the said layer, not only colouring matters such as are
mentioned in the Specification No. 5932-of-1893 above referred to, may be used,
but also coloured-substances, which are not all colouring matters properly speaking,
for instance, nitro or nitroso derivatives of amines, phenols, cresols, resorcine,
naphthols or their sulpho or carbo acids.
It has already been tried to avoid solarisation by bathing dry plates in a solution
of the ammonia salt of picric acid, but by this method the sensitiveness is so
impaired that plates thus prepared completely fail (see Eder, Jahresbuch für
Photographie 1894 page 378).
By applying only an intermediate layer, according to my invention such failure is
avoided.
The preparation of the plates with the substances mentioned above is similar to
that described in the Specification No. 5932 of 1893 above referred to.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in the Manufacture of Photographic Plates.
I, OTTO MAGERSTEDT, of No. 183 Reichenbergerstrasse, Berlin, in the German
Empire, Merchant, 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 certain improvements in the production of photographic
plates, connected with the invention described in my previous Specification No. 5932
of 1893. In this Specification is described a treatment of plates by which the
defects of halation and solarisation are avoided, by placing a coloured layer between
the layer of haloid silver emulsion and the material carrying it.
For the production of the said layer not only colouring matters such as are
mentioned in the Specification No. 5932 of 1893 above referred to, may be used,
but also coloured substances which are not all colouring matters properly speaking,
for instance nitro or nitroso derivatives of amines, phenols, cresols, resorcine,
naphthols or their sulpho or carbo acids.
It has already been tried to avoid solarisation by bathing dry plates in a solution
of the ammonia salt of picric acid, but by this method the sensitiveness is so

page_text: impaired that plates thus prepared completely fail (see Eder, Jahresbuch für
Photographie 1894 page 378).
By applying only an intermediate layer according to my invention such failure
is avoided.
The preparation of the plates with the substances mentioned above is similar to
that described in the Specification No. 5932 of 1893 above referred to.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture of photographic plates free from the defects of solarisation
and halation, by placing between the sensitising haloid silver emulsion and the
plate itself a layer coloured with nitro or nitroso products of the amines, phenoles,
cresols, resorcine, naphthols or their sulpho or carbo acids.
2. Photographic plates prepared in the manner above referred to.
Dated the Ath dox
Conue
LYUD
Unted the 14th dox
ABEL & IMRAY,
Agents for the Applicant.
ABEL & IMRAY,
Agents for the Applicant.