SOILS. 89 



SOILS. 



Having now completed my account of the various mineral substances usually employed in 

 Agriculture, I propose to annex to it a brief and general view of the soils of the State, chiefly 

 in reference to their chemical composition. 



The soil, as it is well known, is a mixture of various mineral substances, with small pro- 

 portions of animal and vegetable matters, usually in the process of decomposition. The mi- 

 neral parts of the soil are composed of the same substances which constitute the mountain 

 rocks and mineral masses which are found on the earth, and form its crust or covering. These 

 rocks are broken down by degrees, and are decomposed by the influence of air and moisture. 



Now all the rocks and other mineral masses which exist on the surface of the earth are 

 found to consist of a few bodies, the principal of which are the following, viz. silica, alumina, 

 lime, magnesia, oxide of iron, soda and potassa. 



The following classification of soils, which is sufficiently particular for my present purpose, 

 is that proposed in a recent standard work on agriculture.* 



1. Siliceous or Sandy Soils. In these, silica or sand predominates. This earth is very 

 widely diffused, being found in quartz, of course entering largely into the composition of gra- 

 nite, and also existing in various silicates, as serpentine, tremolite, diallage, hornblende, (fee. 



2. Aluminous Soils. These contain a large proportion of clay, the basis of which, alumina, 

 is, next to silica, the most generally diffused. Indeed, in combination with silica, it forms a 

 great proportion of all the rocks and mineral masses on the earth. 



3. Calcareous Soils. Those in which carbonate of lime predominates, and which are the 

 result of the breaking down of the different forms of carbonate of lime, or of the various lime- 

 stones which exist so abundantly in all parts of the world. 



4. Magnesian Soils. Those in which magnesia, in various states of combination, consti- 

 tutes an ingredient. 



5. Ferruginous Soils. Those soils in which the oxide of iron is contained in considerable 

 proportion. • 



Tlie soils of this State are as diversified as those of any other territory of equal extent. 

 . There are to be found here examples of all those varieties which have been described by stan- 

 dard authors on Agriculture. It is important to notice these, at least in a general way; as the 

 nature of the soil determines the kind and quantity of manure which may be employed in order 

 to increase its productiveness. 



* Elements of Practical Agriculture, cj-c. By David Low, Esq. F.R.S.E. Professor of Agriculture in tlie University of Edin- 

 Imrgh. — Tliis work was republished in the' Rural Library, by S. Fleet, in 1839, with alterations and additions adapted to the 

 climate and peculiarities of the tainted Slates. 



Part I. 12 . " 



