LIME 1 1 5 



that was in it. This can be avoided by constantly adding 

 vegetable matter and necessary plant-food. 



Do not mix lime with barnyard manure or acid phos- 

 phate, nor add it to a manure pile or compost heap. It 

 rots these materials so rapidly that it drives off into the 

 air a part of the nitrogen or ammonia of the manure, 

 the loss of which is made known by the strong smell of 

 the escaping ammonia gas. A covering of soil over the 

 compost pile would absorb and hold the ammonia ; hence 

 lime in the soil would not do the harm it might when 

 mixed above the ground with manures or fertilizers. 



EXERCISE. If possible get a lump of builder's lime ; weigh it and 

 notice its size ; let water drip slowly on it. Again weigh it and notice 

 its size. What has happened? 



At this rate a barrel of quicklime weighing 165 pounds would make 

 how many pounds of slacked lime? 



NOTE TO THE TEACHER. It will be worth while to buy from a 

 wholesale druggist a 15 -cent bottle of blue litmus paper. Obtain in 

 addition a bottle of red litmus paper, which is turned blue by lime. 

 Have pupils test a number of soils with the blue litmus paper, afterwards 

 showing to the class the paper used and describing the kind of soil 

 found, acid, neutral, or alkaline. Test with blue and red litmus all 

 obtainable fertilizers, also salt, soda, various well-waters, etc. 



FIG. 71. WELL CULTIVATED AND POORLY TILLED SOILS. MUCH REDUCED IN SIZE 

 Lime aids in crumbling clods. 



