Sulphate of Ammonia 



been opened. The sacks ought, also, to be the 

 original ones. Adulteration by means of kainite, 

 which, applied as a top dressing is corrosive, is 

 abominable, since it may cause the loss of a crop, 

 or at least seriously affect the results. 



The action of nitrate of soda is only felt during 

 one season, so that it must be renewed annually. 



Sulphate of Ammonia. 



Sulphate of ammonia, (NH3) 2H2SO4, is a combina- 

 tion of ammonia (HNg) and sulphuric acid (H2SO4). 

 The sulphate of ammonia of commerce is never pure, 

 but it ought not to contain more than 5 per cent, 

 of impurities. It should then contain 20*2 per cent, 

 nitrogen and 24*5 per cent, ammonia. The colour 

 varies according to the impurities it contains, some 

 of which may constitute dangerous poisons to plant 

 life. For example, very white sulphate of ammonia 

 may contain free sulphuric acid. This sulphate will 

 bum the hands and clothes of any one sowing it, 

 rust the manure spreader, and corrode the plants it 

 touches. Red or black sulphate often contains 

 sulphocyanure of ammonia, of which Voelker has 

 proved that less than 10 lbs. per acre is sufficient 

 to destroy the entire crop, and there are sulphates 

 which contain more than a cwt. Sulpho-cyanide 

 of ammonia can easily be recognised, however, 

 because in heating with lime it gives off a strong 

 smell of ammonia. 



Sulphate of ammonia is frequently adulterated 

 with sand or common salt, and sometimes with 

 sulphate of soda, but the fraud can be detected 

 by throwing some of the sulphate on to a white 



39 



