16 
and disappear, the soil working easier and with*much 
more economy. 
There is always moisture enough held in the soil 
by capillary attraction, for all the purposes of vegeta- 
tion, and which cannot be carried off by any number 
of drains. 
We have found by experiment that an ordinary soil 
will hold in suspension nearly half its bulk of water; 
which, in a soil three feet deep, would be equal to 
nearly six months’ rain-fall. Water thus held in 
suspension does not close the pores of the soil, but 
still allows free passage of air, since the solid parti- 
cles, in a friable soil, occupy much less space than 
the pores between them. 
Where the surface soil is porous and gives a ready 
passage to the water, while the subsoil is compact and 
impervious, then the roots of plants are compelled to 
seek their nourishment in the surface soil only. 
Air and warmth, as well as moisture, are indispen- 
sable to growth, and where stagnant water stops out 
the air and keeps the soil cold, there can be no vege- 
tation. It is only on the lowering of the water table 
or surface of stagnant water toa depth of three or 
four feet from the surface, that roots are free to ex- 
tend as deep as they may. Roots of wheat and of clover 
have been traced to the depth of four feet or more, 
on drained land; and in the streets of cities, roots of 
shade trees sometimes extend to a depth of eight feet, 
following the line of sewers. The action of the drains 
is immediately to withdraw the noxious water; and 
