Crystallized Nitrate of Silver absorbs Ammoniacal gas rapidly, with production of heat sufficient to fuse the resulting compound, which is white, and consists of 100 parts of the Nitrate + 29·5 of Ammonia. The compound however which Photographers employ under the name of Ammonio-Nitrate of Silver may be viewed more simply as a solution of the Oxide of Silver in Ammonia, without reference to the Nitrate of Ammonia necessarily produced in the reaction.
Very strong Ammonia, in acting upon Oxide of Silver, converts it into a black powder, termed Fulminating Silver, which possesses the most dangerous explosive properties. Its composition is uncertain. In preparing Ammonio-Nitrate of Silver by the common process, the Oxide first precipitated occasionally leaves a little black powder behind, on re-solution; this does not appear however, according to the observations of the Author, to be Fulminating Silver.
In sensitizing salted paper by the Ammonio-Nitrate of Silver, free Ammonia is necessarily formed. Thus—
| Chloride of Ammonium | + | Oxide of Silver in Ammonia | |
| = | Chloride of Silver | + | Ammonia + Water. |
SILVER, OXIDE OF.
Symbol, AgO. Atomic weight, 116.
This compound has already been described in Part I., [page 17].
Symbol, AgCl. Atomic weight, 144.
The preparation and properties of Chloride of Silver are given in Part I. [page 14].