30 Dr. Kane on the Compounds of Ammonia. 



which are related to one another, through the replacement of hydrogen by copper; 

 the acid had been in the crystals more immediately united with that which repre- 

 sents oxide of ammonium, but on the application of heat, the previous affinities were 

 subverted, and, the acid remaining in union with the group of more permanent 

 constitution, the elements of the ammonia and water are set free, the formula of 

 the green powder being 



(NH3.CM0) . SO3. 



Graham had already pointed out, that when ammoniacal gas is passed over 

 sulphate of copper at a high temperature, but half an equivalent is absorbed, and 

 hence he hazarded the idea, that the resulting compound might be analogous to an 

 ordinary double sulphate, as 



CUO . SO3 -\- (NH3 . CUO) SO3 



corresponding to 



CMO . SO3 -j- (NH3 . ho) . SO3. 



This body can likewise be obtained when the action of the heat on the ammo- 

 niacal sulphate of copper is kept below 400° F. ; there are given off three-fourths 

 of the ammonia with the water, and there remains 2(503. cmo)-1-nh3. 



It is well known that the sulphate of copper in the cold absorbs two and a 

 half equivalents of ammonia, and the resulting body warmed loses two, corrobo- 

 rating fully the view originally struck out by Graham, and to which my results 

 lend considerable support. 



If the apple-green powder be exposed to the action of damp air it gradually 

 becomes blue, from the absorption of water, but the process is very slow ; if, on 

 the other hand, the powder be moistened with a small quantity of water, much 

 heat is evolved, and a full blue colour produced ; if there be any water in excess 

 it may be removed by cautious evaporation at a temperature below 100° F., but 

 a large excess produces complete decomposition. To ascertain the quantity of 

 water which in such case combines with the green powder, 2.820 grammes were 

 very slightly moistened, and the excess of water removed by a temperature of 

 80°. The dry blue powder remaining weighed 3.605, or the green powder had 

 taken 27.8 water per cent., corresponding to three equivalents, and hence the 

 formula NH3 . cmo -\- sOj becomes probably (nHj. ho.) SO3 -f- (cuo + 2ho). 



By the results of the action of a large quantity of water on this green powder 



