84 PEIN'CIPLES OF GARDENING. [CH. II. 



evident, that to insure these desiderata in any soil, at 

 all seasons, is impossible ; and it is as manifest that 

 a soil that would do so in one climate would fail in 

 another, if the mean annual temperature of them 

 should differ, as vrell as the amount in inches of rain 

 ■which fall duiing the same period. Since, in the 

 western parts of England, more than t^\•ice as much 

 rain occurs as in the most eastern counties, or in the 

 proportion of 42 to 19, a soil in the east of England, 

 for any given crop, may be richer and more tenacious 

 than the soil required for it on the westeiTi coast. 



Alumina, or clay, imparts tenacity to a soil when 

 applied ; silica, or sand, diminishes that power ; 

 whilst chalk and lime have an intermediate effect. 

 They render heavy soils more friable, light soils 

 more retentive. These simple facts ai'e impoi*tant : 

 two neighbouring gardens, by an interchange of soils, 

 being often rendered fertile, which, before, were in 

 the extremes of tenacity and porosity. 



From these statements it is evident, that no uni- 

 versal standard, or recipe, can be given for the 

 fonnation of a fertile soil, but a soil, the constituents 

 of which approach in their proportions to those of 

 the follo-\ring, cannot be unproductive in any cli- 

 mate. It is a rich alluvial soil, which Mr. Sinclair, 

 in his invaluable '' Hortus Gramineus Woburnensis,'' 

 gives as being the most fertile for the grasses : 



" Fine sand, 115; aluminous stones, 70; carbonate 



