EXERCISE A-6. TO STUDY THE INDIVIDUAL SOIL 



PARTICLES. 



Equipment: Two tumblers; tablespoon; three large 

 lieakers or quart cans; samples of sand and clay soils. 



Method: (a) Put a tablespoonful of sand in one tumbler 

 and the same quantity of clay in the other. Fill each with 

 water and after thorough shaking, allow the soils to settle. 

 Which settles the more rapidly? 



When a swift ty flowing stream carrying material in sus- 

 pension is checked, which particles are first deposited? 

 Find an example of the sorting power of flowing water in 

 your neighborhood. 



(b) A day or two before the class is to meet put three 

 or four tablespoonfuls of sandy loam soil in a beaker or 

 can and nearly fill the vessel with water. Shake at inter- 

 vals for one day and finally after thorough shaking allow 

 to settle one hour and pour off into another beaker (or 

 can) the muddy water down to within one inch of the 

 bottom. Allow to stand for one minute, again pour off 

 the muddy water and evaporate each separation to dry- 

 ness on a stove. When dry, examine the material in 

 each can; the last residue is sand, the second is silt, and 

 the first separation is clay. Moisten a little of each and 

 rub between the thumb and finger. Which ones are sticky 



and which fall apart easily? 



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