$2 ELEMENTS OF AGRICULTURE. __ 
the smallest number), the richness (organic lemains) is m 
excess, though in very variable proportions. In others 
there is an excess of mineralogical principles. In either 
case the cultivator is the loser ; for in the fust soils, most 
crops would lodge/* and on the second the vegetation 
would be thin and meager. 
6. We must not conclude that the nature of the soil and 
the proportion of its constituent elements alone influence 
its value. Without doubt, these causes contribute much ; 
but there are many other circumstances, such as the expo¬ 
sure and depth of the soil, and the nature of the sub-soil, 
that in a greater or less degree affect the value of land. 
Thus, a lot in which the soil is not more than four inches 
deep, is not near so valuable as one in which it is a foot 
deep, though the soil is precisely alike in each. The 
value of land may also be affected by the nature of the 
sub-soil, for if it be impervious to water, the plants may 
suffer from too much wet; if too porous, they may suffer 
in seasons of drought; and finally the sub-soil may contain 
mineral principles inimical to vegetation. 
7. It results from what we have just said, that the clas¬ 
sification of soils can not depend upon the relative propor¬ 
tions of the elements of which they are constituted, not¬ 
withstanding the contrary opinion, emitted by some emi¬ 
nent writers. It is only by the cultivation of a farm, by 
a close examination of its condition in all seasons, wet and 
dry, and by the consideration of other circumstances that 
we shall indicate hereafter, that we can form an estimate 
approximating its real value. 
* When the growth of grain is too highly stimulated by manure, or any 
other agent, the stems do not acquire sufficient consistence or strength Pi 
maintain an erect position ; they fall down, and this is called 'odging. 
