86 The Relation of the Physical Nature of the Soil, &c. [Feb., 



of ctemistry, will take up this important topic for a liberal discussion 

 in the pages of Tlie Ciucinnatus. 



Fertility of the soil may depend as much on the peculiar form and 

 relation in which the mineral constituents are found in it, as 

 on their presence or absence. Many facts can be presented in proof 

 of this assertion. A soil of the most genial composition may be ut- 

 terly useless, and unfit for cultivation, as long as it retains such 

 quantities of water as to exclude all action of the atmosphere from 

 its interior. Let this soil be drained, and its coherent parts be loos- 

 ened and broken up, and a new state of things will ensue. The air 

 now penetrates into the interior to act upon the salts contained in 

 it, its temperature will be elevated, and bountiful crops will testify 

 what a mighty influence the physical nature of the soil commands 

 over its fertility. In other soils, however, the necessity of minerals 

 to insure fertility is strikingly demonstrated. Such soils often pre- 

 sent the most favorable physical properties; yet a lack of necessary 

 mineral constituents renders them unfit for cultivation. A free and 

 liberal action of the atmosphere upon the soil is undoubtedly not 

 less important and necessary to a successful course of vegetable econ- 

 omy, than the action of the mineral upon the plant. 



A certain degree of porosity is indispensable to every soil, to fit 

 it for successful cultivation. The atmosphere readily takes posses- 

 sion of the vacant spaces which exist between the atoms of the soil. 

 Constant supplies of carbonic acid, ammonia and watery vapors are 

 thus brought to the sei'vice and disposition of the plant ; and those 

 chemical transactions are made possible, which are necessary to pre- 

 pare the mineral constituents to the direct use of the plant. Poros- 

 ity is also indispensable, for another not less important reason. 

 A porous and loose soil receives and maintains a much higher de- 

 gree of temperature, becoming thereby more genial to the germina- 

 tion of the seed, and the development of the plant. Strikingly is the 

 influence of the air upon the soil exhibited on many spots where 

 the farmer's tools have never stirred the ground. What a luxuriant 

 growth does that spot present whose soil is loose and open to atmos- 

 pheric action ; and how scantily and meagerly is mother earth cov- 

 ered in such places, where the surface soil is baked to a hard and 

 impenetrable crust. In our so-called warm and cold soils, this dif- 

 ference is plainly illustrated; the one is loose and porous, the other 

 compact and tenacious. To secure this important action of the at- 

 mosphere, to the benefit of the plant, the farmer unceasingly toils j 



