PLANTS GET FOOD MATERIAL FROM THE SOIL 7 



contains so much lime that every few weeks we have to chip 

 off the scale of lime on the inside of the teakettle. 



Well-water may also contain other substances in solution. 

 Suppose you try an experiment to show this by fastening 

 sprouted kernels of wheat on thin slices of floating cork in 

 such manner that the roots will hang over the edges of the 

 cork down into the water. Put some of the seedlings thus 

 arranged into a tumbler of clean rain-water and others into 

 a tumbler of clean well-water and watch their development. 



A study of the chemical composition of plants reveals 

 the fact that the greater part of the dry matter of the 

 plant is derived from the air. But before it can utilize 

 the elements from the air, the plant must be able to take 

 up certain mineral substances from the soil. 



In ten pounds of mature corn plant there will be found 

 approximately eight pounds of water and two pounds of 

 dry material, of which two ounces have been taken up 

 from the soil, the remainder coming from the air. 



