WITH A VIEW TO HORTICULTURE. 9 



soil, the effects produced will be more immediate from the organic 

 matter which such soil contains ; but even when it is obtained from 

 the subsoil, the change in the condition of the soil to which the new 

 soil is applied will soon be rendered obvious ; though not so much so 

 the first year, as it will be in two or three years afterwards, when the 

 amalgamation of the two soils is more complete. Much of the effect 

 of adding one soil to another will depend on ttair intimate mixture ; 

 and this can be best effected by repeated trenchings or diggings in dry 

 ^-rather, when both soils are as nearly as possible in a state of dry 

 powder. This point is of great importance, particularly when the 

 soils mixed together contain a good deal of organic matter, because if 

 a very intimate mixture of both soils is not effected, they will, from the 

 difference in their specific gravities, in a few years separate into two 

 different strata. There is, indeed, a constant tendency to do this in all 

 soils under culture, and more especially in all such as have been 

 improved by admixture. This takes place in consequence of the 

 softening of the soil by rains, by which the particles are in a manner 

 held for a time in suspension, and the heaviest gradually take a lower 

 place than those which are lighter. Hence the necessity of digging or 

 trenching such soils frequently to the depth to which they have 

 originally been improved. This is required even in artificial soils laid 

 down in grass ; for supposing a clayey soil to have received a con- 

 siderable admixture of lime or chalk, and sand, with rotted stable- 

 dung, and the whole to have been incorporated in a state of fallow, and 

 afterwards sown with grass seeds, then in seven years the black mat- 

 ter or mould remaining from the dung will be found among the roots 

 of the grass at the surface, the sand in a stratum three or four inches 

 below the surface, and the lime at the bottom of the artificial soil. By 

 placing the same mixture in a flower-pot, and watering it frequently 

 during a year, the pot being plunged in the soil, the same result will 

 take place sooner, and be more conspicuous. If the pot be kept con- 

 stantly immersed in water to within an inch of the brim, the result will 

 take place in the course of a few days. These facts ought to be kept 

 constantly in mind by whoever would improve soils by admixture ; if 

 they are not, disappointment is very likely to ensue. When soils mixed 

 together are comparatively without organic matter, and when the par- 

 ticles of which they are composed are very small, the mixture becomes 

 more intimate; the particles of the one soil filling up the interstices 

 among the particles of the other, and the amalgamation as it may be 

 termed is then so complete that the earths will never afterwards sepa- 

 rate. In this way pure sands may be improved by the admixture of 

 pure clays, or by marls or chalks. The words pure and amalgamated 

 are here used, not in a chemical, but in a popular sense. 



Changing the inclination of the surface of soils is a mode of improve- 

 ment that may frequently be adopted on a small scale, by arranging a 

 steep slope into narrow terraces, and a broad slope into level plat- 

 forms. The former, mode has been practised from time immemorial 

 in the Land of Canaan, and in other countries of the East, and the 

 hitter is common in France and Italy, in order to admit of surface 



