6?0 SILVER. 



in 100 parts, of 4 1 .99 bromine and 58.01 silver. It is insolu- 

 ble in water, and falls as a precipitate which is at first white, 

 but becomes of a pale yellow on collecting. When fused and 

 cooled, it gives a mass of a pure and intense yellow. It is soluble 

 in ammonia and has most of the properties of chloride of 

 silver. 



Iodide of silver, Ag I, 2931.1 or 234.87. This salt consists 

 in 100 parts, of 53.89 iodine and 46.11 silver. It is insoluble 

 in water, like the chloride, but is distinguished from that salt 

 by its colour, which is pale yellow, by the difficulty with which 

 it is dissolved in ammonia, and by being blackened more 

 slowly by the action of light. According to Martini, 2500 parts 

 of ammonia, of density 0.960, are required to dissolve one part 

 of iodide of silver. It is soluble to a large extent, at the boil- 

 ing temperature in concentrated solutions of the alkaline and 

 earthy iodides, and forms with them double salts. 



^Cyanide of silver, AgCy, 1681.5 or 134.74. This salt 

 contains, in 100 parts, 19.62 cyanogen and 80.38 silver. It 

 falls as a white powder when hydrocyanic acid is added to a 

 solution of nitrate of silver. It is distinguished from chloride 

 of silver by dissolving in concentrated nitric and sulphuric acids, 

 when heated. It is readily decomposed by hydrochloric acid, 

 and yields hydrocyanic acid, 100 parts of cyanide of silver giving 

 20.36 parts of hydrocyanic acid. It is decomposed by a red 

 heat, and when well dried, gives nothing but cyanogen gas and 

 silver. Cyanide of silver is dissolved by cyanide of potassium, 

 and other soluble cyanides. The double cyanide of potassium 

 and silver crystallizes in octohedrons, K Cy + AgCy. 



Carbonate of silver, Ag O, CO 2 , is a white insoluble powder. 



Sulphate of silver, Ag O, SO 3 , 1952.8 or 156.48. It is ob- 

 tained by dissolving silver with heat in concentrated sulphuric 

 acid, or by precipitating a solution of nitrate of silver with 

 sulphate of potash. It is soluble in 88 times its weight of 

 boiling water, and crystallizes on cooling in the form of anhy- 

 drous sulphate of soda. This salt is highly soluble in ammo- 

 nia, and gives, by evaporation, an ammoniacal sulphate of silver 

 in fine transparent crystals, which are persistent in air ; Ag O, 

 SO 3 42NH 3 . Chromate and seleniate of silver form analogous 

 compounds with ammonia, which are all isomorphous. The bi- 

 chromate of silver is also isomorphous with bichromate of soda. 



Hyposulphate of silver, Ag O, S 2 O 5 , is soluble in water, and 



