52 ORGANIC CONSTITUENTS OF SOIL. 



CHAPTER IV. 



OF THE ORGANIC CONSTITUENTS OF 

 SOIL. 



87. The mineral elements of soil, become part 

 of plants. Under the influence of the mysterious 

 principle of life, they no longer obey the chemical 

 laws, but are parts of a living structure. Life sus- 

 pends all chemical laws. It organizes inorganic 

 matter. To what laws obedient, to what purposes 

 subservient, are the elements of soil during the brief 

 moment, in which they are endowed with life, it is 

 not intended to inquire. Plants by their living pow- 

 er, select from the fifty-five elementary substances, 

 fourteen only ; of these, three are gaseous ; seven 

 belong to the class silicates, and four to the class 

 urets. (44.) 



88. Every plant does not contain the same ele- 

 ments, nor does every part of the same plant ; but 

 every part of the same plant, at the same age, prob- 

 ably contains the same elements, united in definite 

 proportions. Whenever plants die, their elements 



