THE SOIL i; 



A knowledge of their properties will enable us to understand more 

 clearly the characteristics, or natural traits, of soils. 



Sand. Here is a piece of quartz. If you pulverize, or powder 

 it, you will have sand. But the rock is so hard that you would find 

 this difficult to do ; so we will fill a gill measure 

 with sand, which is rock that has been worn 

 down by natural processes. You observe that 

 the sand is heavy, and that it consists of little 

 hard grains. If you try to press it into shape, the 

 dry grains fall apart. Mix it with some water, 

 noticing how much it will absorb, or hold. You 

 can press the wet sand into shape, but it dries 

 quickly and then falls apart again if you han- 

 dle it. Now put the sand into a glass half full A PlECE OF QUARTZ 

 of water, and stir it. The particles separate readily, but when 

 you stop stirring they sink quickly to the bottom of the glass. 

 Soon the water will be clear again. The dry sand does not stick 

 to your fingers, and you can easily rub off the wet particles. 



Clay. Now take a piece of potter's clay. It is so much 

 softer than quartz that we can, without difficulty, grind it to 

 powder. Let us fill a gill measure with this powder, and exam- 

 ine and test it as we did the sand.* We find that it is light in 

 weight. Instead of feeling hard, it is soft to the touch; that 

 is because the particles composing it are very small. If you 

 squeeze it in your hand, it takes the imprint of your fingers. 

 Mix it with water. You find that it absorbs much more than 

 did the sand, and that you can mold it into any shape you 

 wish. It does not dissolve readily in water, and when it does 

 dissolve, it settles very slowly, leaving the water discolored a long 

 time. You find that the wet clay is sticky, and even the dry 

 clay adheres to your fingers and soils them. 



