RICHARDS AND MERIGOLD. — BROMIDES AND SULPHOCYANATES. 137 



dissolving the resulting cupriammonium bromide by the addition of a 

 little acetic acid. The addition to this mixture of a saturated solution of 

 amnionic sulphocyanate caused the precipitation of a blue basic compound, 

 which was dissolved by addition of ammonic hydrate. Soon deep blue 

 crystals separated out from the solution. These were washed with alcohol 

 and ether, and dried by pressing between filter paper. The washing with 

 alcohol and ether must not be prolonged, otherwise the crystals lose their 

 brilliant appearance and become covered with a coating of whitish basic 

 salt. Prepared in this way, the compound occurs in very brilliant, deep 

 blue crystals. On exposure to the air the crystals lose ammonia readily, 

 and at the same time lose their brilliant lustre and become light blue in 

 color. The salt is decomposed by water and by dilute acids; it is soluble 

 in boiling concentrated hydrochloric acid, in cold strong nitric acid, and 

 in ammonic hydroxide. 



Analyses of Cu(NH3)4(SCN)2. 



I. 0.2540 gram of substance gave, on electrolysis, 0.0641 gram of 

 copper. 

 II. 0.2064 gram of substance, distilled with caustic potash, required 

 33.71 cubic centimeters of a decinormal acid solution for neutrali- 

 zation. 

 in. 0.3454 gram of substance, distilled with caustic potash, required 

 55.20 cubic centimeters of a decinormal acid solution for neutrali- 

 zation. 

 IV. 0.1839 gram of substance required 14.71 cubic centimeters of a 

 decinormal argentic nitrate solution to precipitate the sulpho- 

 cyanic acid. 

 Y. 0.3555 gram of substance required 28.38 cubic centimeters of deci- 

 normal argentic nitrate solution for precipitation of sulphocyanic 

 acid. 



