CAPILLARY ATTRACTION. 



69 



TABLE C. 



Kinds of Soil. 



Silicious sand, 



Calcareous sand, .... 



Gj'psum, 



Light clay, 



Stiffish clay, 



Sti-ong clay, 



Pure clay, 



Chalk}' soil, in fine powder, 



Garden earth, 



Humus, 



In 12 hours. In 24 hours. In 48 hours. In 72 hours 



grains. 

 0. 



0.154 



0.077 



1.617 



1.925 



2.310 



2.849 



2.002 



2.695 



6.160 



grains. 

 0. 



0.231 



0.077 



2.002 



2.310 



2.772 



3.234 



2.387 



3.465 



7.469 



grains. 

 0. 



0.231 



077 



2.156 



2.618 



3.080 



3.696 



2.695 



3.850 



8.470 



grains. 

 0. 



0.231 



0.077 



2.156 



2.695 



3.157 



3.773 



2.695 



4.004 



9.240 



Capillarij attraction. This consists of the sucking 

 up of the moisture from the subsoil to the surface 

 of the earth. It takes place in different degrees in 

 all soils. In some it is not sufficient to sustain 

 vegetation when the surface becomes dried by the 

 heat of the sun, and therefore the crops suffer from 

 drought. In others it is in excess, and constantly 

 keeps the soil cold and wet, which it is the object 

 of draining to prevent. Capillary attraction, to a 

 certain extent, is of great importance to the growth 

 of vegetation, as the moisture which arises generally 

 contains valuable saline properties, which are left 

 in the soil when the moisture escapes by evapora- 

 tion. 



State of division^ cohesion, and adhesion. In very 

 stiff lands, the labor of the cultivator is principally 

 expended in producing that friability which is ne- 



