8G 



combinations, and converts them into that state in 

 which alone they are available for plants. In 

 other words, the inorganic plant-food passes from 

 a chemically combined state to one of physical 

 combination with the porous soil. 



An analysis of a soil, therefore, which does not 

 show the number and quantity of its different consti- 

 tuents present in the available form of plant-food, 

 nor exhibits them separate from those which may 

 become available in course of years by appropriate 

 manures or the disintegrating influence of external 

 agencies, is entirely useless to the practical 

 agriculturist. 



To arrive at correct conclusions of the compara- 

 tive sterility or fertility of a soil, and of its suit- 

 ability for certain crops, as well as of the means to 

 effect permanent improvements, an analysis of a 

 soil, representing the average of the uppermost ten 

 inches, should exhibit the following particulars : 



(1) The percentage of stones and sand, as dis- 



tinct from clay and other impalpable matter. 



(2) The percentage of water it can absorb. 



(3) The percentage of water it will evaporate 



within a certain time when exposed to 

 the atmosphere. 



(4) The percentage of organic matter. 



(5) A chemical analysis of the mineral consti- 



tuents which are dissolved out of the soil 

 by digesting it for twenty-four .hours in 



