98 Dr. Kane on the Compounds of Ammonia. 



after that time, the continuance of the heat occasions the loss of more ammonia, 

 but no more water is disengaged. Unless the heat be very accurately managed, 

 sulphite of ammonia is apt to make its appearance before the last portions of the 

 ammonia have been expelled ; with care, however, a sulphate of zinc almost com- 

 pletely soluble in water may be obtained. 



To determine more closely what occurs in the case just noticed, 4.238 

 grammes of the powder formed by the efflorescence, at 100°, of the crystals were 

 heated until the sulphate of zinc remained pure behind ; it weighed 2.800, or 

 66.07 per cent. 



4.385 of the same powder were heated until it had fused, and the escape of 

 water had ceased, great care being taken to seize the precise time, and to avoid 

 the application of any unnecessary heat ; the residual mass weighed 3.470, or 

 79.13 per cent. 



XT 66.07 80.50 J ., „. ^c^A , r. 



3393 ~ 4Ym' ~ + ^' 'I" P' ^"^ + ^^* 



The proportion of ammonia being a little less than two atoms. 

 Again, the second experiment gives 



" ■ > zr 79.13 of residual fused mass; 



and 



Ammonia 13.06 



66.07 80.50 1 80.50 z«o so, 



= , or nearly — •* 



13.06 15.91 17.14 NH3 



The effloresced powder was therefore 



zno SO3 + 2NH3 + HO, 



corresponding to the crystallized ammonia-sulphate of copper, and by heat it loses 

 NH3 . HO, and there is formed 



S03.ZnONH3, 



being precisely the same as in the copper series. This effloresced powder put 

 into water dissolves almost without residue, provided the water be free from 

 carbonic acid. 



The reasoning which I employed concerning the rational formulas of the 



