AND AGRICULTURE. 



65 



Pig. 20. 



farm-yard manure ; they contain a large quantity 

 of ammonia. 



These manures should not come into imme- 

 diate contact with the seed, but should be well 

 mixed with a suitable quantity of earth. 



Quick-lime should never be mixed with guano. 

 or other manures containing ammonia ; because 

 the lime sets the ammonia free, and allows it to 

 escape into the atmosphere. ' 



You may easily 

 be satisfied of this 

 fact. Take a little 

 slaked lime, and mix 

 it with a small quan- 

 tity of guano, or the 

 excrement of pig- 

 eons, etc., in a tea-' 



mi 

 cup. Ihe ammonia 



will be at once recognized by its peculiar smell ; 

 and you may see it by holding over the cup a 



Questions. What does the excrement of birds contain 

 in large quantity ? Should they be applied directly to the 

 seed ? Why should not lime be mixed with manures con- 

 taining ammonia ? How can you prove that manures lose 

 their ammonia if mixed with lime ? 



6* 



