THE SOIL 



21 



EXPERIMENTS 



1. Try for yourself the experiments with sand, clay, and humus 

 described on pages 16, 17, and 18. 



2. Get specimens of sandy and clay soil and loam. Compare them 

 as to color and weight, and as to size of particles. 



3. Make a rack, like the one in 

 the illustration, by boring holes in 

 one side of a box. Get three glass 

 tubes or straight lamp chimneys, tie 

 a cloth over the smaller end of each, 

 and put in one sand, in one clay, 

 and in one garden loam or wood 

 mold. Set them in the rack w r ith 

 the lower end of each over a glass 

 of water, as illustrated. Pour water 

 into them. Through which does it 

 percolate first ; which absorbs most 

 water before it begins to drip ; which 

 takes longest to become dry ? 



ILLUSTRATION OF EXPERIMENT 3 



For this and other experiments it is well to have an eight-ounce grad- 

 uated glass, such as druggists use, in which to measure water. 



4. Fill three tubes, as before, with the three kinds of soil. Set 

 them in the rack w r ith the lower end of each in a glass of water. In 

 which tube does water rise most rapidly, and in which does it rise to 

 the greatest height ? 



5. What is the character of the soils of your section ? Collect and 

 examine some specimens and write an account of them. 



Many interesting experiments with soils may be made by the use of 

 a set of soil sieves, which separate particles according to size. Sepa- 

 rate a soil and make the same tests with each of the classes. The 

 differences in power to absorb and retain water are due largely to the 

 differences in size of particles. 



