MANURES. 



carbonic acid formed will have a beneficial chemical 

 action in the soil, and will be directly presented to 

 the roots instead of escaping into the atmosphere ; 

 and if the soil be heavy, the decomposing matters 

 will tend to loosen it, and leave it more porous. As 

 a general rule, however, in ordinary farming, where 

 the amount of manure applied is only sufficient for 

 the supply of food to the crop, it is undoubtedly bet- 

 ter to have it previously decomposed, cooked as it 

 were, for the uses of the plants, as they can then 

 obtain the required amount of nutriment as fast as 

 needed. 



ABSORPTION OF MOISTURE. 



It is often convenient to know the relative power 

 of different manures to absorb moisture from the at- 

 mosphere, especially when we wish to manure lands 

 that suffer from drought. The following results are 

 given by C. "W. Johnson, in his essay on salt (pp. 8 

 and 19). In these experiments the animal manures 

 were employed without any admixture of straw. 



PARTS. 



1000 parts of horse-dung, dried in a tempera- 

 ture of 100, absorbed by expo- 

 sure for- three hours to air saturated 

 with moisture, of the temperature of 

 62 145 



1000 parts of cow-dung, under the same cir- 

 cumstances, absorbed 130 



1000 parts pig-dung 120 



1000 " sheep " . 81 



