HOW SOILS ARE MADE AND MIXED 3 



EXERCISE 1 



Object. — To see how layers of soil are made by the 

 action of water. 



Procedure. — Bring half a cupful of soil from any field 

 at home or from any place near the school. Put half of 

 it in a pint jar or in a wide-mouthed bottle and the re- 

 mainder in another. Then fill each a Uttle over half full 

 of water. Shake well and allow them to stand until the 

 close of school to-day. Then shake again and set them 

 aside until class period to-morrow. This is done in order 

 to break apart all the small lumps. Number the jars 

 one and two. 



Does the soil seem to have settled in distinct layers? 

 Which sized particles settled first? Have you not seen 

 the soil along the bank of a stream in layers like this? 



Now shake jar number two vigorously again and allow 

 the contents to settle one minute. Pour off the water 

 into a third empty jar, leaving in the bottom of the second 

 the soil that has settled. Allow the third jar to stand one 

 hour, and pour off the water into a fourth jar, leaving the 

 soil that settled in the third jar. Allow the fourth jar to 

 stand until class time to-morrow. 



The soil that settled in one minute is the sand ; that, in 

 one hour is called silt; that, in twenty-four hours, the 

 clay. 



Do you find that the layers of soil in jar number one 

 look like the soils in jars two, three and four? 



Dip a little of the soil out of jars two, three and four 

 with a small wooden paddle and examine each carefully 

 with a hand lens and by rubbing between the thumb and 

 fingers. Which one is pasty? Which is made up of 

 coarse particles? Would you hke to have a field of pure 

 clay? Why not? Would you like to have one of pure 



