18 Combinations of Ammonia with Chlorides. [1818. 



to the coating. It is probable that a solution of silver of this 

 kind might be applied in some cases in the arts, to the pur- 

 poses of ornament and utility. 



Combinations of Ammonia with Chlorides *. 

 IT has been already shown, particularly by Sir H. Davy, 

 that several of the binary compounds of chlorine, as those of 

 phosphorus, tin, &c., exert a strong affinity for ammonia, con- 

 densing it when in the gaseous state, and neutralizing its 

 alkaline properties. The combinations which will here be 

 offered to notice are of a different kind, and if they deserve 

 any attention, it will be in consequence of the weakness of the 

 power which is exerted in their formation, and the slight 

 change of properties induced on the substances by union- 

 It has been frequently observed by chemists, that if well- 

 fused chloride of lime be placed in ammoniacal gas, there 

 is a rapid absorption of the gas, and the chloride becomes 

 covered with a white powder. If ammonia be repeatedly 

 added until the absorption ceases, the mass of chloride swells, 

 cracks, splits in all directions, and at last forms a white pul- 

 verulent substance. 



Exposed to the atmosphere, it deliquesces, but not so 

 rapidly as chloride of lime. Thrown into water it dissolves, 

 forming a strong alkaline solution. Heated, it gives off am- 

 monia, and the chloride remains unchanged. Placed in chlo- 

 rine it inflames spontaneously, and burns with a pale yellow 

 flame. 



The fused chlorides of barium and strontium suffer a very 

 slight change in ammoniacal gas in many days ; after more 

 than a fortnight, the chloride of strontium, weighing about 30 

 grains, had absorbed only a cubical inch of gas, and a slight 

 efflorescent appearance was seen on the broken edge. 



A piece of fused chloride of silver, weighing about 30 

 grains, placed in ammoniacal gas, gradually absorbed more 

 than 40 cubical inches. The action took place over the 

 whole surface of the mass, but most speedily at the fractured 

 edges. The chloride swelled considerably, and crumbled into 

 powder. The substance formed was at first white, but it 



* Quarterly Journal of Science, v. 74. 



