66 THE SOIL. 



By piii'siiiiig the proper course, it is easy to lear^ 

 all that is necessary to form a good foundation for a 

 thorough acquaintance with the subject. If this 

 foundation is laid thoroughly, the learner Avill regard 

 plants and soils as old acquaintances, with whose 

 formation and properties he is as familiar as with the 

 construction of a building or a simple machine. A 

 simple spear of grass will become an object of inter- 

 est, forming itself into a perfect plant, with fall de- 

 velopment of roots, stems, leaves, and seeds, by pro- 

 cesses with which he feels acquainted. The soil will 

 cease to be mere dirt ; it will be viewed as a com- 

 pound substance, M-hose composition is a matter of 

 interest, and whose care may become a source of in- 

 tellectual pleasure. The commencement of study 

 in any science must necessarily be wearisome to the 

 untrained mind, but its more advanced stages amply 

 repay the trouble of early exertions. 



CHAPTER 11. 



USES or ATMOSPHERIC MATTER. 



It will be recollected that, in addition to its mineral 

 portions, the soil contains atmospheric or organic mat- 

 ter in varied quantities. It may be fertile witli but 

 one and a half per cent, of atmospheric matter, and 

 some peaty soils contain more than fifty per cent, or 

 n:ore than one-half of the whole. 



