22 LIFE ON THE FARM. 



moisture is drawn upward just as the oil is drawn 

 by a lamp wick. 



Another important fact should be mentioned 

 regarding the capillary movement of water in soil. 

 Water is the greatest of solvents, that is, it dis- 

 solves more substances than any other. So, when 

 water sinks into the earth, it dissolves out many of 

 the ingredients of the soil, especially the plant 

 foods, and these would be permanently lost were 

 there no such power as surface tension to bring it 

 back again in reach of the roots of plants. Every 

 one knows, of course, that warm water has greater 

 dissolving power than cold water; so, when the 

 chilly winter rain fills the earth with stores of 

 water, it does not carry down much dissolved 

 material with it; but when summer comes, with its 

 plants, and its thirsty, warm air to cause evapora- 

 tion, that same water is drawn back to the surface, 

 dissolving as it comes nutritious substances from the 

 deeper soil and leaving them at the place most 

 needed. Then, too, the warm, summer rains 

 which dissolve so many rich substances of the 

 top soil, find it laced and interlaced with the roots of 

 growing plants to catch it before it can get away. 



The soil, in its natural state, such as that of a 

 forest, sees to it that all these forces are equally 

 balanced, and tha't'there is little waste; but, in the 

 cultivated state, the conditions are so changed that 

 the soil soon becomes poor if great care and wis- 

 dom are not exercised. 



