20 Combinations of Ammonia with Chlorides. [1818. 



limate is converted into calomel in consequence of the action 

 of the ammonia at high temperatures. Heated with potash, 

 the ammonia is driven off, the chlorine is removed from the 

 mercury, and red oxide results. 



Some crystals of calomel were introduced into ammoniacal 

 gas ; they immediately blackened on the surface, and gas was 

 absorbed. The action appeared to be exactly similar to that 

 exerted when calomel is thrown into solution of ammonia. A 

 black substance is produced, which though repeatedly washed 

 in distilled water, gives off ammonia by heat, and calomel with 

 a little mercury sublimes. 



A piece of fused chloride of lead exerted but little action in 

 a fortnight ; a small quantity of gas was absorbed, and a very 

 superficial combination had been formed. 



Chloride of bismuth absorbed a small quantity of ammoniacal 

 gas, which was again given out by heat ; there was no remark- 

 able change in appearance. 



A small piece of chloride of nickel being placed in ammo- 

 niacal gas, absorbed it, and in twenty-four hours was converted 

 into a bulky powder of a pale rose tint. The ammonia was 

 separated by exposure to air, to water, or to heat. 



Chloride of copper fused was powerfully acted upon by 

 ammonia. It immediately burst open upon being placed in 

 the gas, and absorbing great quantities fell into a blue powder. 

 The compound placed in water was decomposed, and an am- 

 moniacal solution of copper produced. Heated, it fused, 

 boiled, the ammonia flew off, and the chloride remained. 



The protochloride of iron introduced immediately after 

 fusion into ammoniacal gas, exerted an instantaneous action ; 

 great quantities of gas were absorbed, and a very light ad- 

 hesive white powder was formed. Exposed to the air, it im- 

 mediately changed colour, became yellow, brown, then green, 

 and ultimately black : this effect resulted from the presence of 

 water in the atmosphere, and the separation of oxide by the 

 ammonia; and the substance offers a test, if one should be 

 wanted, for the presence of aqueous vapour. A portion of it 

 thrown up into a small receiver of common air over mercury, 

 immediately changed colour, and became brown. When the 

 powder was heated out of the contact of air it gave off am- 

 monia, and the chloride remained. 



