SAND 



13 



When a soil containing large amounts of clay and silt 

 is treated with water, the silt settles slowly, while 

 the clay remains in suspension. The fine deposit in 

 ditches and drains, where the water moves slowly, is 

 mainly silt. 



7. Sand. There are three grades of sand. The 

 characteristics, as permeability and non-cohesion of 



Fig. i. Medium sand X 150. Fig. 2. Fine sand X 150- Fig- 3- 

 Very fine sand X 150- Fig. 4. Silt X 325. Fig. 5. Fine silt X 

 325. Fig. 6. Clay X 325. 



particles, are so well known that they do not require 

 discussion. A soil composed entirely of sand would 

 have little, if any, agricultural value. Sandy soils 

 usually contain from 5 to 15 per cent, of clay and 

 silt. The relative sizes of sand, silt, and clay are given 

 in the illustration. 



