ON FALLOWING. 183 



husbandry that is known to produce fertility in 

 the soil, acts in unison with them ; indeed, under- 

 draining proves, comparatively, that agricultural 

 plants do better without water, than when immer- 

 sed in stagnant water ; and irrigation shews, that 

 when rapidly changing, a plant can scarcely have 

 too much water. Digging and ploughing, and 

 hoeing, stirring, and turning up the soil j not only 

 loosens the texture, and thereby admits a more 

 perfect percolation of water; but spongy vegeta- 

 ble matter, that, whilst under the earth, retains 

 water in a state of stagnation, is brought upon 

 the surface; the unwholesome moisture evapor- 

 ated, and the substance reduced to a state more 

 absorbent, but less retentive. 



When the earth is in a proper state, or the 

 soil and subsoil properly constituted, and under 

 proper circumstances ; a constant circulation or 

 motion of the water up and down among the 

 roots of vegetables, is going on ; — thus, when rain 

 falls in sufficient quantity; by its gravity, it per- 

 colates and sinks through the soil. And again, 

 as soon as the surface of the earth is sufficiently 

 rarefied to pass off what it retains in vapour, the 

 motion is reversed, and by the capillary attraction 

 of the soil the water is again raised, and brought 

 to the surface, and in its passage upwards again 

 comes in contact with the roots of vegetables; and 



N h 



