ON DRAINING. 81 



and supply the loss. In this way tlie deep ricli loams to 

 wliicli I have before adverted as so rare and so coveted, are 

 maintained in a nearly constant condition of moisture, suit- 

 able to tlie necessities of plants. It may and does, tlioug'li 

 rarely, lia])pen, that even such soils, during- long-continued 

 droughts, sufter, — that is, become too dry ; but the attentive 

 observer will notice a very beautiful and powerful provision 

 of nature to prevent excessive dryness. During- the nig-ht, 

 evaporation from the surface of soil commonly ceases, to 

 commence ag-aiu when the rays of the sun imping-e upou 

 it ; but capillary action is constant, and of equal intensity, 

 both by nig'ht and by day ; so that we have, on the averag-e, 

 twelve hours per diem of the sun's influence to produce 

 evaporation, and twenty -four hours of capillary action to 

 supply the loss from below, and maintain a tolerably uni- 

 form hyg-rometric or moist condition of the active soil. It 

 is, I believe, consistent with the universal opinion, that 

 drained lands do not burn nor suiFer from droug-ht so soon, 

 or so much, as those soils which are wet at all periods of 

 the year except during- the hottest months. This pheno- 

 menon is explained by the fact of a retentive soil swollen 

 by water contracting- so much, by the loss of its water, that 

 it is almost inaccessible to air, from which to obtain mois- 

 ture. After drainag-e, the mechanical texture of such soils 

 becomes g-radually chang-ed; pulverization takes place in 

 the subsoil in a manner precisely similar to the chang-e we 

 see produced in fresh turned-up soil well exposed to the 

 atmosphere ; such chang-e of texture in the mass belovv^ is 

 doubtless slower than in the superficial soil, but it is equally 

 certain to occur. 



Perhaps no more striking- illustration of the g-reat im- 

 portance of securing- free ing-ress to air, and free eg-ress to 

 water, in the mass of the soil, can be given than that which is 

 derived from the fact, that by allowing land to rest without 

 cropping it — in short, by fallowing it — fertility is renewed, 

 and this effect is ])roduced solely by supplies furnished from 

 the inexhaustible magazine of the atmosphere. The atmo- 

 sphere is our cheapest, it is a boundless storehouse of manure : 

 then why not let it freely and deeply into our soil ? The 

 earnestness with which I appeal to the landed proprietary of 

 Britain to drain more deeply, and abandon the ofttimes 

 abortive, and at all times incomplete, system of shallow 

 drains, is derived from the indications of experience ; and to 

 those well informed of the superior economy and efficiency 



a 



