THE SOIL AS AN ASSET 239 



variance with the established teachings, the 

 scientists who "stand pat" on the Liebig theory 

 say they do not. 



This brings us back to the question of what 

 becomes of the soluble salts in the commercial 

 fertilizers which we add to the soil in order, so 

 we are told, to increase the amount of "avail- 

 able" plant food. 



The experiment of adding these chemicals 

 to the soil and trying to extract them again 

 by distilled water seems to prove that we have 

 not affected the ratio of liberation in the least. 

 What has become of this plant food? In an 

 actual test, 4,000 parts of very soluble potash 

 was mixed with 1,000,000 parts of soil. Yet 

 distilled water extracted only 25 parts at a 

 time. It seemed impossible to raise the con- 

 centration of this solution no matter how long 

 the water was left in contact with the soil. 

 So with phosphoric acid. 



The soil grains absorbed the salt. 



The absorptive power of the soil is a 

 phenomenon that has been observed for many 

 years. As far back as 1859 (American Jour- 

 nal of Science and Arts), Johnson put it 

 thus: 



