

PRINCIPLES 



OF 



PRACTICAL AGRICULTURE, 



L SOILS.* 



I. REMARKS ON THE DIFFERENT CLASSES AND CHARACTER OF 



SOILS. 



BY analyzing the substance which constitutes the coat *or 

 outer covering of the earth, denominated soil, it is found to 

 consist of a combination or mixture of several distinct and 

 separate descriptions of matter which chemists have denomi- 

 nated primitive earths, forming a stratum or layer, varying 

 from a few inches to several feet in depth. This stratum or 

 soil possesses no uniformity of colour, but is naturally some- 

 what dark, a circumstance arising from the admixture with it 

 of the decomposed stems, leaves, and other parts of plants 

 which have sprung up upon it, and in part often by the pre- 

 sence of animal substances, together with certain saline and 

 mineral ingredients. It is this outer coat or covering of the 

 earth in which plants are produced. 



It is this mixture of animal and vegetable substances with the 

 mineral matter of the upper stratum, which distinguishes it 

 from the mass of earth or rock lying beneath it, to which the 

 term SUB-SOIL is applied. The decomposed animal and vege- 

 table portion of the soil may be termed mould; and it is the 

 presence of mould accordingly which distinguishes the soil 

 from the sub-soil.* 



Soils may be distinguished according to their texture and 



* In this and the following section, we have, in part, adopted the arrange- 

 ment and some of the opinions of PROFESSOR Low, the fundamental principles 

 of the science being the same in every country. 



t Low on Agriculture. 

 2 



