14 



PRACTICE 6 



Determination of the Variation in the Hygroscopic Capacity 

 of Soils. 



In this exercise each student will use air-dried soils provided for 

 the purpose. These are sand, loam, silt, clay and peat. 



Determine the percent of moisture lost when heated for 5 hours 

 at 100° C. This is the hygroscopic moisture. Express in percent of 

 water-free soil. Care must be taken to weigh out all samples at the 

 same time to avoid any change in the amount of moisture due to a 

 change in relative humidity. 



Explain differences between clay and sand. 



Between peat and sand. 



