I860.] 



THE SOUTHE 



RN PLANTER. 



475 



hence the great importance of underdrain- 

 ing. 



Chemists employ sulphuric acid in their 

 experiments for absorbing moisture. Lime 

 and caustic potash are also used. Soils pos- 

 sess the absorbent power in an eminent de- 

 greC; and it is by that inherent quality that 

 plants are enabled to resist extreme droughts. 

 The power of absorption depends greatly 

 upon division, color, &c. A dark soil ab- 

 sorbs heat more readily than a light-colored 

 one ; it also radiates heat quicker. When 

 the sun sets, the >;arth begins to radiate; 

 in proportion as it cools, will be the amount 

 of dew deposited. When a gas passes to a 

 liquid state, caloric is evolved ; such is also 

 the effect when a liquid passes to a solid. 

 The reverse occurs when a solid becomes 

 liquid, or a liquid a gas. By the conden- 

 sation of vapor, or the formatien of dew, 

 heat is evolved ; by the absorption of dew, 

 a further degree of sensible heat is pro- 

 duced. This process prevents a too sudden 

 change of temperature in the surface of the 

 earth, and which otherwise would have been 

 sensibly affected by the too great radiation 

 of heat. This equalization is brought about 

 in a manner to excite our admiration. Evap- 

 oration is far more rapid in a dry, than in a 

 moist atmosphere, and more rapid in a cur- 

 rent of air than when it is still or stagnant. 

 Dry, porous, and thoroughly pulverized soils 

 radiate heat from a vastly greater number of 

 points than wet and compact soils, and re- 

 ceive more abundant depositions of dew. 

 Sands are powerful absorbents, and some 

 countries depend almost wholly upon this 

 for the support of vegetation. The sandy 

 plains of Chili seldom receive any rain ; yet, 

 in consequence of their excessive radiation 

 of heat and the heavy dews at night, they 

 maintain a high fertility. If a soil be suf- 

 ficiently permeable to the air, condensation 

 may take place below during the day, at the 

 same time that the surface may be giving off 

 both heat and moisture, which is due to the 

 relative degree of heat between the two. 



To the farmer and the gardner, the soil is 

 that portion of the earth's surface or crust 

 which supports vegetation, or that is suscep- 

 tible of cultivation, and is rich or poor ac- 

 cordingly as it is well or illy adapted to pro- 

 duction. Soils are formed from the decom- 

 position and disintegration of rocks, and 

 are either from those immediately underly- 

 ing, or may have been brought from a dis- 

 tance by causes still acting, or that have 



ceased to operate. h« * >i« 



* * * The soil has a varied 



composition, according to locality and cir- 

 cumstance. The decomposition or disinte- 

 gration of an argillaceous rock would natu- 

 rally give rise to a soil in which aluminous 

 properties would preponderate. If the soil 

 originated from a silicious rock, then it 

 w^ould be sandy; if from limestone, we should 

 expect it to be calcareous. These and other 

 substances, variously intermixed with or- 

 ganic matters in different states and stages 

 of decomposition, form soils. They owe 

 their properties to the distinctive minerals 

 from which. they are derived. 



These inorganic constituents do not exist 

 in the atmosphere, and are supplied by the 

 earth, as they do not grow; and having been 

 created once and forever, it follows that, if 

 removed, they must be replaced. It does 

 not matter how removed, whether in the 

 form of grass, grain, milk, flesh, or bone, if 

 taken away they are gone, so far as the far- 

 mer is concerned. This principle lies at the 

 foundation of all successful agriculture, and 

 is the fundamental axiom for which Liebig 

 and others have so long, so laboriously and 

 ably contended. 



It would be as ridiculous for the miner to 

 suppose that his exhausted placer would 

 yield as much gold by re-working, as for 

 the farmer to think that his exhausted lands 

 would be recuperated without the addition 

 of the substances extracted from it. 



All the constituents of soil are compounds : 

 they are oxydes of some metallic base, the 

 organic portions are animal and vegetable 

 substances in a decomposing state, complex 

 and passing by degrees to simple forms. 

 Soils, then, in complexion and composition 

 vary. Two soils originating from the same 

 rock may differ widely, in consequence of 

 mechanical condition, subsoil, situation, cli- 

 mate, and cultivation. But as rocks are the 

 same in all parts of the world, so must they 

 give rise to a similarity of soil. In one hun- 

 dred and forty-six soils analyzed by the geo- 

 logical surveyor of Massachusetts, taken 

 troni every variety of rock formation, the 

 most remarkable uniformity was presented. 

 These, again, as compared with forty-eight 

 soils from Germany, Holland, Belgium, Hun- 

 gary, and Bohemia, offer the same striking 

 uniforminty, differing but slightly from 

 American soils. (Dana's Muck Manual.) 

 These facts would appear to show that there 

 is not only a great similarity, but that their 



