CHAPTER I. 

 GEOLOGY OF SOIL. 



1. Agricultural Chemistry aims to explain all 

 the actions of earth, air, and water, upon plants. It 

 refers to all their chemical relations, to the geology, 

 mineralogy and chemistry of soil. 



2. Agricultural geology explains the relations 

 which soil bears to plants, and the manner in which 

 that affects vegetation. 



3. Agricultural geology confines itself to facts. 

 It digs into the earth, observes what composes that ; 

 how its components act upon plants. Conversant 

 only with facts, or logical deductions from these, it 

 leaves to geology proper, the vast mass of observa- 

 tions, supported by the highest modern science, 

 which teaches the origin, mode of formation, original 

 condition, and successive changes which our globe 

 has undergone. 



4. The terms, primitive and secondary, used by 



geologists, are almost parts of common language ; 



yet, need to be explained to the farmer. 

 1* 



