50 



the natural blue color of the soil itself is seen below, while near the 

 surface it is rusted yellow by tlie decay of certain minerals M'hich 

 contain iron. 



Few materials on the earth are more important than the soil ; it 

 acts as the intermediary between man and the earth. The rocks 

 liave some substance locked up in them which annuals need ; by 

 decay, or by grinding up, the rocks crumble so that plants may 

 send roots into tliem and extract the substances ueeded by animals. 

 Gifted with this wonderful power the plants grow and furnish foods 

 to animals, some of them the very plant-foods from the rocks ; and 

 so the animals of the land, and man himself, obtain a large part of 

 their food from the rocks. It is then worth the while to stop for a 

 moment and think and study about this, one of the most marvelous 

 of the many wonderful adjustments of nature, but so common that 

 most people live and die without even giving it more than a passing 

 thought. 



PART II: WHAT IT DOES. 



BY L. A. CLINTON. 



The more one studies the soil the more certainly it will be found 

 that tlie earth has locked up in her bosom many secrets, and that 

 these secrets will not be given up for the mere asking. As mys- 

 terious as the soil may appear at different times, it always is governed 

 by certain laws. These principles once understood, the soil becomes 

 an open book from which one may read quickly and accurately. 



Uses of the Soil. 



The soil has certain offices to perform for which it is admirably 

 fitted. The most important of these offices are : 



1. To hold plants in place. 



2. To serve as a source of plant-food. 



3. To act as a reservoir for moisture. 



4. As a storehouse for applied plant-food or fertilizer. 

 Some soils are capable of performing all these offices, while others 



are fitted for only a j)art of them. Thus a soil whicli may be pure 

 sand and almost entirely deficient in the essential elements of plant- 



442 



