63 



PRACTICE 30 



The last two weeks of the semester will be devoted to the estima- 

 tion of the constituents of a larger number of soils. It is quite im- 

 portant that one should be able to estimate approximately the amount 

 of gravel, sand, silt, clay and organic matter in soils and it is the ob- 

 ject of this exercise to enable the student to do this. Each one will be 

 given a sample of soil to be studied according to the outline below. 

 The work is to be done rapidly and the graduated cylinder may be used 

 as an aid in estimating the amount of each constituent. 



In using the graduated cylinder, place 10 cc. of soil in it and almost 

 fill with water. Shake thoroughly and allow it to stand for one-half 

 minute or longer. Note the amount of sand in cubic centimeters. 

 Soil No. 

 Dry 

 Color 

 Odor 



Pulverulent, crumbly, cloddy. 

 Moist 

 Color 

 Odor 



Floury, mealy or gritty 

 Friable or plastic 

 Composition 

 Organic matter (estimated) in percent 

 Gravel (estimated) in percent 

 Sand (estimated) in percent 

 Silt and clay (estimated) in percent 

 Name of soil. 



