434* Prof. Kane on White Precipitate, 



limit at which the decomposition stops. In these cases, how- 

 ever, the powder product is not so bright in colour as that 

 produced by the action of mere water. It does not appear to be 

 quite so pure, but in its properties it manifests complete identity. 

 Nevertheless, in order to leave no room for doubt upon the 

 matter, I decomposed corrosive sublimate by a great excess 

 of ammonia, added a strong solution of potash, and boiled 

 for a considerable time. The yellowish white powder pro- 

 duced, was separated by the filter and washed until the li- 

 quors ceased to affect turmeric paper: dried carefully. It 

 weighed from 100 of sublimate, 85 grains. When heated it 

 gave out water, ammonia, and azote, and calomel with me- 

 tallic mercury sublimed. When suddenly heated, it puffed 

 up, more so than the pure yellow powders, which was pro- 

 bably the reason of its having been confounded with the am- 

 moniuret which possesses a very slight detonating property. 



To analyse it, 66*83 grains were dissolved in muriatic acid, 

 and having been diluted were decomposed by a current of 

 sulphuretted hydrogen gas. The black sulphuret was collected 

 on a weighed filter, and having been carefully dried, weighed 

 67*70 grains, consisting of 



Mercury 58*42 



Sulphur 9*28. 



The liquor evaporated, gave sal-ammoniac 6*58 grains, 

 consisting of 



Chlorine 4*35 



Hydrogen *12 



Ammonia 2*11. 



There were thus obtained from 66*83 of this powder, 



Mercury 58*42" 



Chlorine 4*35 



Ammonia 2*11 



Oxygen and loss ... T95 

 But the yellow powder by water, should have given from 

 the formula : 



(2 Ch + Hg) + 2 Hg + (2NH 2 + Hg) 

 Mercury ...... 57*30" 



Chlorine 5*00 



Amidogene 2*28 



Oxygen 2*25 



This result proves the identity of the effect in the two cases 

 of the action of water and of an alkali. 



Rose and Grouvelle have already shown that when dry 

 ammonia is passed over melted sublimate, an atom of the 

 former is absorbed by one of the latter, and a white mass 



^66*83. 



^66*83. 



