Manufacture of a New Solid Silver Compound which is not Precipitated by Albumen or Salt.
Year: 1894

page_text: Date of Application, 16th Nov., 1894
Complete Specification Left, 15th Aug., 1895-Accepted, 21st Sept., 1895
[Communicated from abroad by THE FARBWERKE, vormals MEISTER LUCIUS
AND BRUNING, of Hoechst a/Main, Germany, Chemical Manufacturers.]
Manufacture of a New Solid Silver Compound which is not
Precipitated by Albumen or Salt.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention to be as follows:-
For certain practical purposes it is of value to possess silver solutions, which
although not containing free alkali, are not precipitated by albumen nor by salt.
This invention consists in the manufacture of such a silver compound from
casein as follows:
3 kilos. sodium salt of casein containing no free alkali are mixed with
300 grammes nitrate of silver and the mixture is dissolved in water by the aid
of heat.
If this solution be precipitated with alcohol or cautiously evaporated in vacuo
after drying the precipitate produced by alcohol, or after powdering the residue
of the evaporation in vacuo, a white substance is obtained which is soluble in
water with reaction neutral to litmus.
This substance differs from a mixture of the solid sodium salt of casein and
silver nitrate inasmuch as that on treatment with sulphuretted hydrogen and
subsequent addition of ammonia it gives no precipitate of silver sulphide but
forms a clear brown solution.
In preparing the new silver compound any other soluble salt of silver may be
employed instead of silver nitrate.
Instead of the sodium salt of caseïn a mixture of casein with one of the alkali
compounds in which it is soluble may be employed. Thus, for instance, a mixture
of 1 gramme silver nitrate and 10 grammes casein sodium phosphate (3 grammes
casein, 26 cubic centimetres of a normal solution of disodic phosphate) dissolves
in 200 cubic centimetres of water forming a solution which exhibits the above
characteristic properties in regard to albumen and salt.
Dated this 16th day of November 1894.
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of a New Solid Silver Compound which is not
Precipitated by Albumen or Salt.
1, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane in the
County of London, Chartered Patent Agent 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 :—
For certain practical purposes it is of value to possess silver solutions, which
although not containing free alkali, are not precipitated by albumen or by salt.
D

page_text: This invention consists in the manufacture of such a silver compound from caseïn
as follows: 3 kilos. sodium salt of caseïn containing no free alkali are mixed with
300 grammes nitrate of silver and the mixture is dissolved in water by the aid
of heat.
If this solution be precipitated with alcohol or cautiously evaporated in vacuo
after drying the precipitate produced by alcohol, or after powdering the residue of
the evaporation in vacuo, a white substance is obtained which is soluble in water
with reaction neutral to litmus.
This substance differs from a mixture of the solid sodium salt of casein and
silver nitrate inasmuch as that on treatment with sulphuretted hydrogen and
subsequent addition of ammonia it gives no precipitate of silver sulphide but forms
a clear brown solution.
In preparing the new silver compound any other soluble salt of silver may be
employed instead of silver nitrate.
Instead of the sodium salt of caseïn a mixture of caseïn with one of the alkali
compounds in which it is soluble may be employed. Thus, for instance, a mixture
of 1 gramme silver nitrate and 10 grammes casein sodium phosphate (3 grammes
cascin, 2.6 cubic centimetres of a normal solution of disodic phosphate) dissolves
in 200 cubic centimetres of water forming a solution which exhibits the above
characteristic properties in regard to albumen and salt.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :
1. The herein described manufacture of a solid compound of silver which in
aqueous solution gives no precipitate with albumen or salt, by mixing solutions
of silver salts with neutral solutions of caseïn alkali compounds and precipitating
the solutions thus obtained with alcohol or evaporating them in vacuo.
2. The solid compound of silver produced as above set forth.
Dated this 15th dow of Amund 1005
ABEL & IMRAY,
Agents for the Applicant.