4 THE FARMER AND NATURE 



by evaporation, and the corn will suffer on that account. 

 This rapid evaporation through a crusted soil is due to a 

 physical force or principle (capillary attraction), about 

 which more will be learned in Chapter VII. To prevent 

 too rapid a loss of moisture the farmer cultivates, or breaks 



A PLEASANT FARMHOUSE. 

 Nature adds charm to the farmer's home. 



up, the crust, because this principle acts more slowly in a 

 loose soil. 



b. A sqed drops into the soil ; it seems lifeless. It 

 will remain apparently as lifeless as a pebble unless heat, 

 moisture, and air are applied to it. In the soil, in a good 

 season, it finds these three things, and it sprouts. Sprout- 

 ing is growth, and growth is a biological principle. 



c. A farmer spreads lime on the land ; the lime 

 "sweetens" the soil, and thus enables certain plants to 

 thrive better. This work of lime illustrates a chemical 

 principle. We shall explain these principles more in 

 detail in later chapters. 



