BENEFITS POROUS SOILS. — ORIGIN OF MOOR-LAND. 31*1 



of the subsoil which had previously prevented the roots from descend- 

 ing. 



C. It is a necessary preparation to the many other means of improve- 

 ment which may be applied to the land. 



You will now be able to perceive in what way it is possible that 

 even light and sandy soils, or such as lie on a sloping surface, may be 

 greatly benefitted by draining. Where no open outlet exists under a 

 loamy or sandy surface soil, any noxious matters that either sink from 

 above, or ooze up from beneath, will long remain in the subsoil, and 

 render it more or less unwholesome to valuable cultivated plants. But 

 let such an outlet be made by the establishment of drains, and that 

 which rises from beneath will be arrested, while that which descends 

 from above will escape. The rain-waters passing through will wash 

 the whole soil also as deep as the bottom of the drains, and the atmos- 

 pheric air will accompany or follow them. 



The same remarks apply to lands which p^sess so great a natural 

 inclination as to allow the surface water readily to flow away. Such a 

 sloping surface does not necessarily dry the subsoil, free it from noxious 

 substances, or permit the constant access of the air. Small feeders of 

 water occasionally make their way near to the surface, and linger long 

 in the subsoil before they make their escape. This is in itself an evil ; 

 but wben such springs are impregnated with iron the evil is greatly 

 augmented, and from such a cause alone a more or less perfect barren- 

 ness not unfrequently ensues. To bring such lands by degrees to a 

 sound and healthy state, a mere outlet beneath is often alone sufficient. 



It is to this lingering of unwholesome waters beneath, that the origin 

 of many of our moor-lands, especially on higher grounds, is in a great 

 measure to be attributed. A calcareous or a ferruginous spring sends up 

 its waters into the subsoil. The slow access of air from above, or it 

 may be the escape of air from water itself, causes a more or less ochrey 

 deposit,* which adheres to and gradually cements the stones or earthy 

 particles, among which the water is lodged. Thus a layer of solid 

 stone is gradually formed — the moor-land fan of many districts — which 

 neither allows the roots of plants to descend nor the surface water to es- 

 cape. Hopeless barrenness, therefore, slowly ensues. Coarse grasses, 

 mosses, and heath, grow and accumulate upon soils not originally in- 

 clined to nourish them, and by which a better herbage had previously 

 been long sustained. Of such lands many tracts have been reclaimed 

 by breaking up this moor-land pavement, but such an improvement, 

 unless preceded by a skilful drainage, can only be temporary. The 

 same natural process will again begin, and the same result will follow, 

 unless an outlet be provided for the waters from which the petrifying 

 deposit proceeds. 



It ought to be mentioned, however, that where a ready passage and 

 escape for the water is provided by an efficient drainage, and especially 

 in light and porous soils, the saline and other soluble substances they 



• If the wafer contain 8M//)^afe of iron, the air from above will impart to its iron an ad- 

 ditional quantity of oxygen, and cause a portion of it to fall in the slate of peroxide. If the 

 iron or lime be present in the state of fticarbonate, the escape of carbonic acid from the 

 water will cause a deposit of carbonate of iron or of lime. Any of these deposits will 

 cement the earthy or stony particles together. Iron, however, is sometimes held in solu- 

 tion by an orgaxiic acid (wentc), which becomes insoluble, and falls along with the iron 

 when the latter has absorbed more oxygen from the atmosphere. 



