CHAPTER VIII. 



ANALYSIS OF SOILS. 



THE agriculturist may, by long experience and close obser- 

 vation of the character and productions of his lands, become 

 acquainted with their general character and fertility, and 

 also what plants are best adapted to them. But it is desirable 

 that a more accurate knowledge of the elementary constitution 

 and the relative proportions of those elements which constitute 

 the food of plants, should be attained. 



The only direct and certain means of arriving at this result 

 is chemical analysis. Without this process, it could only be 

 known by a trial of various crops upon different soils, whether 

 they were adapted to them or not: and, in order to determine 

 the value of soils in this way, several crops and much labor 

 might be lost in unsuccessful experiments. 



Analysis of plants shows with absolute certainty what sub- 

 stances they have drawn from the soil and atmosphere for 

 food; these substances vary in different plants, both in their 

 nature and proportions: the same is also true in relation to 

 the elementary composition of soils. No two plants and no 

 two soils have precisely the same chemical composition. The 

 absence of a single element in a soil may render it totally bar- 

 ren for a particular crop, while it may produce some others in 

 great abundance. 



A chemical difference in two soils, which might appear 



