THE SOIL, HOW MADE, AND FROM WHAT . 27 



at once, then successively the finer grades and silts 

 which can be seen lying one above another, while the 

 clay still remains afloat in the turbid (roily) water; 

 and the last of it may not settle for days, weeks, or 

 months, unless settled by lime or salt. 



Or, prepare the soil in the same way, pour it into a large 

 tumbler or glass jar, stir it up with water, and allow it to 

 settle. After half an hour pour off the turbid clay water, 

 stir the earth up again, let it settle, and pour off again, and ' 

 so on until the water remains nearly clear. The sand and 

 silt can then be stirred up again and the water poured off 

 after four, two, one, half, and a quarter minute, pouring the 

 water with the sediments into a separate tumbler each time. 

 The different grades can then be seen each by itself. 



Or, if you have pipe water under pressure, connect the 

 faucet with a small pipe or glass tube and let a stream of 

 water run into the sediment in the tumbler at different rates, 

 catching the overflow in soup plates, in which the different 

 grades of sand and silt can be best seen. Black specks of 

 humus are seen in the finer grades, and sometimes the clay 

 is quite dark with it. 



If you have a piece of rubber tubing about six feet long, 

 you can use it to siphon water from a bucket. By placing a 

 step ladder on the table and raising the bucket from one 

 step to another you can get different rates of flow. 



Clay is peculiar. Dry clay touched by the tongue 

 clings to it. When wet clay is touched by the finger, 

 it clings to it in a lump. When dry clay is wetted, it 

 swells, and when dried after wetting and -working, it 



