96 ACTION OP SALTS. 



what the action of a salt will be ; and whether he 

 may apply one, or less than one per cent, of it, 

 without risking his crop. 



145. Such a general principle, can be deduced 

 from the known chemical action of the elements of 

 soil, aided by the living plants, upon each other. It 

 is this tenth principle of agricultural chemistry, the 



BASE OF ALL SALTS, ACTS EVER THE SAME IN AGRI- 

 CULTURE. Peculiarity of action depends on 



THE ACID OF THE SALT. 



146. Forget, reader, all other principles which 

 have been presented to you. Banish from your 

 mind, if you will, all that has been said, on the ori- 

 gin and nature of soil. Put it down, all, all to the 

 account of book farming. Let it be branded all as 

 theory, and that too as the worst of theories, theory 

 fruitless, a goodly blossom bearing no fruit, a Dead 

 Sea apple ; but do not condemn the principle now 

 enunciated. Let that stand alone, by itself, for it- 

 self. In all its length and breadth, it is the great 

 practical principle of agricultural chemistry. It 

 opens veins, rich in results, more precious than 

 mines of gold. 



147. The action of salts in agriculture, is to be 

 regarded in a twofold light. First, a large propor- 

 tion of salts is found in plants, composed of alkalies 



