Improvements in the Production of Halogen Compounds of Silver.
Year: 1897

page_text: Date of Application, 10th Nov., 1897
PROVISIONAL SPECIFICATION.
Improvements in the Production of Halogen Compounds of Silver.
A communication from CHEMISCHE FABRIK VON HEYDEN GESELLSCHAFT MIT
BESCHRANKTER HAFTUNG, of Radebeul, near Dresden, Saxony, German
German Empire, Manufacturers.
I. JOHN CLAYTON MEWBURN, of the Firm of J. C. Mewburn and Ellis, of 55
and 56, Chancery Lane, in the County of London, Chartered Patent Agents, do
hereby declare the nature of this invention to be as follows:-
The hitherto known silver halide salts AgCl, AgBr, AgI, are as is well known
insoluble in water. My foreign correspondents have accordingly endeavoured
to produce soluble silver halide salts and after considerable experiment they
have succeeded in the endeavour by acting with halogens upon the so-called
colloidal silver, which as is known was first prepared by Carey Lea.
"
Silver chloride, bromide and iodide may be obtained in aqueous solution by
treating the dark solution of colloidal silver with chlorine bromine or iodine
until decoloration takes place. The halogens may be employed in solid, fluid
or gaseous state or preferably in solution. Water, alcohol or other suitable
indifferent liquid may be employed as the solvent. The solutions of silver halide
salts thus produced range in color from white to bright yellow and when
sufficiently dilute are transparent and opalescent. If small proportions of mineral
acids were added to the salt solutions the silver halides would be precipitated
in the ordinary insoluble form from these solutions. If precipitation were
effected by means of sodium acetate the precipitates would partly contain
colloidal silver halides. The separation of the soluble silver halides is how-
ever preferably effected in solid yet soluble form by addition of gelatine and
66
33
ammonium citrate.
The new silver halide salts are particularly suitable for photographic purposes
and may also be employed for other technical purposes and as medicaments.
Dated this 10th day of November 1897.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.
Improvements in the Production of Halogen Compounds of Silver.
A communication from abroad by CHEMISCHE FABRIK VON HEYDEN GESELL-
SCHAFT MIT BESCHRAENKTER HAFTUNG, of Radebeul, near Dresden, Saxony,
German Empire, Manufacturers.
I, JOHN CLAYTON MEWBURN, of the Firm of J. C. Mewburn & Ellis, of 55
and 56, Chancery Lane, in the County of London, Chartered Patent Agents, do

page_text: 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 follow-
ing statement:-
The hitherto known silver haloid salts AgCl, AgBr, Agl, are as is known
insoluble in water. My foreign correspondents have accordingly endeavoured
to produce soluble silver haloid salts, and after considerable experiments they
have succeeded in this endeavour by acting with halogens upon the so-called
colloidal " silver, which as is known was first prepared by Carey Lea.
Silver chloride, bromide and iodide may be obtained in aqueous solution by
treating the dark solution of colloidal silver with chlorine, bromine or iodine
until decoloration takes place. The halogens may be employed in solid, fluid
or gaseous state, or preferably in solution. Instead of water other suitable in-
different liquids may be employed as the solvent. The solutions of silver haloid
salts thus produced range in color from white to bright yellow, and when
sufficiently dilute, are transparent and opalescent. If small proportions of
mineral acids and salt solutions were added to the solutions of silver haloid salts,
the silver haloids would be precipitated in the ordinary insoluble form from
these solutions. If precipitation were effected by means of sodium acetate the
precipitates would partly contain "colloidal silver" haloids. The separation
of the soluble silver haloids is however, when separation is desired, preferably
effected in solid yet soluble form by addition of gelatine and ammonium citrate.
I will proceed to give an example of the manner in which the invention may
be carried into effect, but I premise that this example may be varied within wide
limits:-
Example. Chlorine solution of 06 per cent. strength is gradually added to
10 litres 0'5 per cent, dark aqueous solution of colloidal silver until decoloration
takes place. The operation is carried out in the cold, light being excluded.
The new silver haloid salts are particularly suitable for photographic pur-
poses, and may also be employed for other technical purposes and as medicaments.
Having now particularly described and ascertained the nature of the said
invention as communicated to me, and in what manner the same is to be per-
formed, I declare that what I claim is;-
1. The method of producing soluble haloid salts of silver which consists in
causing a halogen to react with colloidal silver.
2. As new products, the soluble haloid salts of colloidal silver, such as are
produced in the manner hereinbefore described.
Dated this 8th day of August 1898.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.