120 ACTION OF SALTS. 



beneficial. An explanation, which attributes the 

 action of sulphate of lime or plaster, to its power of 

 decomposing and fixing in soil, carbonate of ammo- 

 nia ought to show, 1st. the actual presence of that 

 salt in air ; 2d. that sulphate of ammonia is not de- 

 composed by the resulting carbonate of lime in the 

 cold ; 3d. that common salt, would in equivalent quan- 

 tity with plaster, produce equally good effects. It 

 never has, and therefore this explanation is not correct. 



Secondly, Muriates or chlorides, as they are 

 strictly called, as common salt, muriate of lime, bit- 

 tern, spent ley from soap-works. Common salt has 

 been found beneficial when applied at the rate of 30 

 bushels per acre; and at 14 bushels per acre, was 

 found to produce effect, next best to 53 bushels of 

 ashes per acre, but quick lime at 26 bushels per 

 acre on the same land, produced no good result. 



171. In all this action of salts, it is seen that the 

 presence of life seems almost essential. Whatever 

 the vital principle may be, it may be best represent- 

 ed as analogous to electricity and galvanism. In 

 this point of view, the salts present themselves in a 

 new relation. In a relation, in which alone, they 

 may be said to be stimulants or excitants. Plants 

 and soil act, it may be supposed, for illustration, by 

 forming galvanic batteries, or piles with each other. 



