HOW WE ROB THE SOIL. 
95 
or tiles underground, in such a way that the water 
can enter the channels formed by them and thus be 
carried off. 
9. Sometimes, in wet seasons, the earth is drawn 
up into small hills, in which the plants are grown. 
In this way we not only increase the depth of soil 
for them; we also keep it from becoming soaked. 
It is far better, however, to drain the soil thoroughly. 
On the steep hillsides, so common in Jamaica, 
drainage does much good by making room for fresh 
supplies of rain-water to pass into the land. When 
the water rushes over the surface instead of entering 
it, much of the fine, useful soil is often washed 
down. 
HOW WE ROB THE SOIL. 
1. In places where the land is not cultivated, as 
in a forest, trees and plants die and decay on the 
spot where they lived. On decaying, they give to 
the soil even more than they drew from it, because 
most of their substance was built of the carbon 
their leaves took from the carbonic acid of the air. 
From the subsoil, too, their roots brought up plant- 
food which also went towards the growth of the 
plant. 
2. In this way the surface soil is improved, and 
the remains of the vegetation that grew upon it 
enrich its store of plant-food. 
