128 THE SPIRIT OF THE SOIL 



The complexities of these substances do not con- 

 cern us. What has clearly to be borne in mind as 

 regards them is the simple means by which their 

 acid properties can be neutralized. This can be done 

 readily by means of Lime [Ca(OH) 2 ] or Ammonia 

 (NH 4 OH, orNH 3 ). Thus 



H H 



C-C^ H C C/ 



| X)H X O 



H OH H \ n H\ 







+ Ca<; = Ca + 



H Npfl H / "H/ 



I /OH | /> 



H C C/ H C C< 



i ^ i %0 



Acetic Acid. Lime. Calcium Acetate. Water. 



or 



H H 



I J S\ I ^ /H H \ 



H C C<; +H^ N _ _ H=H _ (> _ C ^ /H + \ Q 



I X OH j*/ i x o N:S: H/ 



H H 



rl 



Acetic Acid. Ammonia. Ammonium Acetate. Water. 



Four fundamental processes occur in the soil in 

 connection with the decomposition of organic matter. 

 Oxygen is added to or taken from the molecule, and 

 the elements of water are added to or taken from 

 the molecule. If some indication can be given to 

 the reader as to how these processes can occur, the 

 general scheme of soil chemistry will easily be 

 grasped. 



In the changes that carbohydrates undergo in 

 becoming peat the most striking feature is the way 

 in which the molecule is continually increasing the 





