AGRICULTURE WITH CHEMISTRY. 45 



PARTICULAR EFFECTS RESULTING "FROM THE APPLJi 

 CATION OF LIME AND CHALK TO GROUND. 



Lime is known to have a tendency to sink below the 

 upper surface, and to form itself into a regular stratum 

 between the fertile and the unfertile mould. After 

 breaking up pasture ground that formerly had been 

 limed on the sward, it is frequently observed in thiy 

 situation : — this has been generally ascribed to its spe- 

 cific gravity, and to its acting in a mechanical manner. 

 In gravelly, or sandy soils, there can be no doubt but 

 that the diffusibility and smallnessof the particles of lime 

 will induce it mechanically to sink through the larger 

 particles of the sand or gravel, and to remain at rest oni 

 the more compa(5l stratum which may resist its passage. • 



When lands of this description have been limed, and 

 kept constantly under annual crops, the greater mechani- 

 cal process of the plough will operate against the lesser- 

 one of subsidence, and keep the lime diffused through 

 the soil: but in clayey or loamy soils, which are equally 



diffusihle 



