66 Dr. Kane on the C<ympounds of Ammonia. 



of zinc, weighing 2.023, corresponding to 54.66 per cent. Its composition, 

 therefore, is : 



Sulphate of zinc = 54.66 

 Volatile matter = 45.34 

 and 



54.66 80. 50 = zno.soa 



45li4 - 66.77 = 34.28 NH3 + 32.49 



Consequently the water is — — = 3.61 equivalents, and as the salt is efflores- 



cent, the true number is probably four. 



When these crystals have been left in the open air for some time they lose 

 altogether their transparency, but retain their form, assuming the milky lustre of 

 the crystals of nitrate of lead. When these milky crystals are heated they melt, 

 and are decomposed with precisely the same phenomena as the transparent ones, 

 leaving a sulphate of zinc redissolving completely in water. 



3.030 of these crystals, so treated, gave 1.818 of sulphate of zinc, or 60 per 

 cent. ; hence, 



as ^ = -— and 53.66 - 34.28 = 19.38. 

 40 53.66 



The quantity of water had evidently been reduced to one-half by efflorescence, 

 no ammonia having been lost, as was ascertained by experiment. 



In the decomposition of this salt by heat, the ammonia and water go off 

 together to the end, and this is easily seen, as the material lost is exactly 

 2(nh3. ho). 



By the first application of the heat it was mentioned that the salt fused after 

 it had lost a certain proportion of gas and water ; this fused mass, on cooling, 

 solidifies into a mass like gum, which may be again melted, and the remaining 

 ammonia and water expelled, as above described. In order to ascertain whether 

 the fusion of the mass occurred at any definite point In the process of decompo- 

 sition, a quantity of the effloresced salt was heated until completely fused, the 

 lamp was then removed, and the weight of the residual gummy-looking material 

 determined, — it amounted to 80.29 per cent. ; and hence it results that the 

 quantity of volatile matter lost had been exactly half of the entire amount, thus. 



