S^unior IKlaturalist /Ibontbl^ 



Published by the Collese oi Agriculture of Cornell 

 University, from October to May, and entered at 

 Ithaca as second=-cIas5 matter. L. H. Bailey, Director 



ALICE Q. McCLOSKEY, Editor 



New Series. Vol. 2 ITHACA, N. Y., JANUARY, 1906. 



No. 4 



OF WHAT THE SOIL IS COMPOSED, AND THE KINDS OF 



SOIL 



O. H, FippiN 



The soil is made of small particles of rock and of decayed plants. 

 In most soils nearly all these particles are bits of rock of all sizes. Stones 

 and pebbles may be found, but most of the particles are so small that they 

 cannot be seen with naked eye. A hundred of the finest particles in a row 

 would only equal the thickness of this paper. These finest particles are 

 called clay. Those particles a little larger are called silt, and a handful of 

 them would feel soft and velvety. The fine particles that can be seen 

 with the eye alone are sand. Some of these sand particles are very fine 



and can just be seen, 

 while others are as 

 larqe as the head of 

 a pin. Sand feels 

 gritty and makes a 

 dull harsh noise when 

 rubbed together. 



A lump of soil may 

 contain all these dif- 

 ferent sized particles. 

 It may look as if it is 

 composed of a lot of 

 little grains, but these 

 are the fine particles 

 that stick together. 

 Stones and gravel are 

 a real part of the soil when they occur in it. 



When these difi'erent sized particles are mixed in different amounts, 

 they form different kinds of soil. If most of them are very fine, the soil 

 is a clay and when wet has a slippery, greasy feeling. If the soil contains 

 mostly sand particles, it is a sand or sandy loam. It may consist of the 

 coarse or the fine grade of sand, or all of these, as is usually the case. 



369 

 24 



Fig. I. — Experimenting with soils. 



