140 MANURE. 



and ammonia, must be formed among the silicates 

 and roots of plants on which they are to act. 



202. Having determined the mode of expressing 

 the value of manures, and fixed the standard of value, 

 other manures containing salts and geine, may 

 now be compared with that, and their value deter- 

 mined, by detailing their constituents. 



203. Horse dung contains : 



Water, 71-20 



Hay, bile and slime, 27* 



Silica, *64 



Phosphate of lime, *08 



Carbonate of lime, *30 



Phosphate of magnesia and soda, *58 



Loss, *20 



100-00 



The food of the horse will of course affect these 

 results, and hence there is found a great discrepancy 

 in the amount of the elements, at different times. 



204. Expressing the value compared with cow 

 dung, we have — 



Geine, 27* 



Salts, -96 



Water, 71-20 



The geine then, is nearly double that in cow 



