20 FERTILIZERS. 



heaps of barn dung which were kept for a year. In one of 

 these, to which had been added 0.5 per cent of carbonate 

 of lime, there was a loss of 9.78 per cent of the nitrogen. 

 Where 1 per cent of plaster had been mixed with a heap, 

 there was a loss of but 0.34 per cent ; where 1 per cent 

 of sulphate of magnesia had been mixed, the heap was en- 

 riched with 5.06 per cent of nitrogen ; while 1 per cent of 

 kainite added 7.97 per cent, which must have come from 

 the air. For such reason as this, kainite becomes very val- 

 uable to sprinkle in stables, or mix in manure heaps to 

 both fix and absorb ammonia. That word, " fix," ammonia 

 will bear a bit of defining ; and I will stop right here and 

 define it, because it will be likely to be used again before 

 we get through with our treatise. Ammonia in animal 

 manure, especially the liquids, is more or less in the form 

 of carbonate of ammonia. In this form it is volatile, and, 

 escaping into the air, is lost. It is this that makes us sneeze 

 when working over manure heaps. When in the form of 

 a sulphate (i.e., sulphate of ammonia), though it can be dis- 

 solved in water, yet it is not volatile. Now, sulphuric acid 

 likes ammonia better than it likes magnesia, while carbonic 

 acid likes magnesia better than it does ammonia : therefore, 

 when sulphate of magnesia and carbonate of ammonia are 

 brought near each other, there is a mutual divorce and a 

 remarriage all around ; and, the new unions being more 

 stable if not sedate, we have the non-volatile sulphate of 

 ammonia and the carbonate of magnesia. 



There remains yet another hearty good word to speak 

 for kainite. Says Professor Dabney, " Lime promotes the 

 action of kainite to a very marked degree ; kainite is, by 

 itself, frequently a proper application to swamp-lands and 

 new lands, being also a powerful digestive agent." The 

 action of kainite may be either a direct one, supplying pot- 

 ash where potash is needed, or an indirect one, through the 



