185 



Now the oxide of zinc from the sulphate heing redissolvetl 

 by potash, there must be formed the similar compound 



k.o.so 3 + ZWO.KO. 



This cannot be obtained crystallized, for if the liquor be 

 evaporated there is deposited ko.so 3 , and zwo.ko remains dis- 

 solved ; from this, by exposure to the air, there are gradually 

 deposited small crystals, which Dr. Kane considers as being 



ko.co 2 + zn o.co 2 + 2 ho. 

 but by heat there is carbonic acid given off, and a powder 

 insoluble in water is produced, the composition of which, 

 from Dr. Kane's examination, appears to be 



ko.co 2 + zjio.co-2 + 2 z«o. 

 It will be recollected, that the bicarbonate of potash is 



ko.co 2 + ho.co 2 . 

 By treating the ammonia sulphate No. 3 or 5 by water, 

 there is obtained a basic sulphate, having the formula 



ZMO.SO3 + 6 z«o + 12 HO. 

 which, dried and exposed to the air, slakes, and gives 



ZWO.SO3 + 6 zrao + 3 ho. 

 This new salt has some remarkable relations to those already 

 known. 



There are two ammonia chlorides of zinc. 

 No. 1, in pearly scales of a talcy lustre, consists of 

 zncl + 2 nh 3 +ho, 



and, when heated, gives off nh 3 .ho. leaving nh 3 .zw cl. a white 

 powder. 



No. 2 is in fine quadrangular prisms, brilliant lustre, con- 

 sisting of 2 zn cl + 2 nii 3 + ho. or, as Dr. Kane considers, 

 zn.cl + (nh 3 .hc£) + nh 3 .z«o. which losing nh 3 .ho leaves 

 ZHc/4-NH 3 .z»d. a white mass, fusible, congealing into a 

 mass like gum, and volatilizable. This gummy mass is like- 

 wise obtained by heating nh 3 z« cl. 



