b4 ELEMENTS OF AGRIC b'LTURE. 
uxyde of iron; and oxyde of manganese. These last two 
are the only mineral parts that give color to the soil. 
11. If the whole of the soil was formed of one of these 
elements, it would be completely barren ; it could only be 
rendered fit for cultivation by mixing with it a sufficient 
quantity of earth. 
12. Soils that contain much silex are called light, or 
sandy ; those, on the contrary, that contain much clay, # 
are called strong, stiff, or clayey. 
13. A clayey is .much more compact and tenacious than 
a sandy soil. It is almost always very difficult to work ; 
whereas a light soil is easily worked, at all times. 
14. The different soils, then, may be divided into three 
classes, as regards their tenacity, or the difficulty of work¬ 
ing them, and their fitness for one vegetable rather than 
another: 1. Silicious, or light land. 2. Loamy land, or 
that which is brought to a medium consistence, either by 
amendments, by manures, or even by cultivation. 3. Stiff, 
or clayey lands. There are, however, several other divis¬ 
ions admitted, depending upon the nature and quantity 
of the constituent elements of the soil. Thus those are 
called calcareous soils, which contain carbonate of lime; 
peaty soils are those which contain peat; ferruginous or 
ocherous soils, those which contain iron or ochre; and 
finally those are called alluvions, that are formed by the 
deposites of streams and rivers, — and these are usually the 
best for cultivation. 
15. If it is useful to be thoroughly acquainted with the 
properties of the constituent elements of a soil, it is less 
with a view to appreciate the value of the land, than 
to ascertain what ameliorators! should be employed in its 
improvement. 
* Clay is a combination of alumine and silex. 
t We designate as ameliorators those substances which, placed in the soil, 
*hange its nature, by rendering it more friable, or more compact. Thus, 
