20 SOILS. 



are enabled to comprehend in what manner that object may be 

 obtained. 



Silicious (sandy) and aluminous (clayey) earths, by their 

 texture, as before observed, serve to cure the defects of each 

 other. The open, loose, thirsty, and hot nature of sand, being 

 corrected by, and correcting in turn the close, adhesive and 

 wet properties of aluminous earth. This curative operation is 

 merely mechanical; it seems probable that calcareous earth, 

 when in large proportion, also aids the corrective power of 

 other earth. But earth is not the only substance contained in 

 soils.* 



Much is said of the analysis of soil, by which is understood 

 its decomposition, or the separating of its parts so as to exhibit 

 the different ingredients it contains and the proportions of 

 each. By the basis of any soil, we understand the primitive 

 earths which enter into its composition. See Appendix A. 



A substance that exists largely diffused in the mineral king- 

 dom, is oxide, or rather peroxide of iron. It is found exten- 

 sively in mountain rocks, and it exists accordingly, in more or 

 less quantity, in almost every soil. Its precise effects, how- 

 ever, on the productive power of soils, have not been well de- 

 termined; some soils, where it exists, being extremely barren, 

 while in some very fertile soils it exists in large quantity. 

 Soils which contain much of iron may be termed FERRU- 

 GINOUS. 



It is therefore all important that the farmer should acquire 

 sufficient knowledge to comprehend and understand the nature 

 and properties of his soil, and the various substances of which 

 it is composed in all or on all of which he is daily engaged. 

 His subsequent efforts to improve the soil, will no longer be 

 submitted to guess work, but will be regulated by a correct or 

 proper knowledge of the materials he may have to work with 

 how each may be best applied or acted upon with the greatest 

 advantage, and what effects will ensue from their different com- 

 binations. There is no need for the farmer to be a profound 

 chemist, though he would be a gainer by it. He should cer- 

 tainly understand enough to enable him to distinguish the cha- 

 racter of the great variety of soils, and the proportions of their 

 various combinations. 



Lord DUNDONALD, in a treatise published many years since, 

 says that the cultivator "should understand the properties and 

 effects, and superior affinities of alkalies and acids as well as 

 the names, properties, and compounded electrive attractions 

 attendant on the mixture of the different neutral salts, and their 

 effects on vegetation. They should be well acquainted with 



* See an interesting paper on this subject by JOSEPH CLOITD, Esq., in Far- 

 mers' Cabinet. 



