16 ADVERTISEMENT TO 



and to describe tlie same without any risk of" being 

 misunderstood. 



Sir H. Davy states the proportion of sand and im- 

 palpable earthy matter, to which the terms usually 

 adopted should be limited. The term sandy should 

 never be applied tu any soil that does not at least con- 

 tain seven-eighths of sand ; sandy soils, that effervesce 

 with acids, should be distinguished by the name of 

 calcareous sandy soil, to distinguish them from those 

 that are siliceous. The term clayey should not be 

 applied to any land, that contains less than one-sixth 

 of impalpable earthy matter, not considerably effer- 

 vescing with acids. The word loam should be li- 

 mited to soils containing at least one-third of impal- 

 pable earthy matter. A soil to be considered as 

 peaty, ought to contain at least one-half of vegetable 

 matter. These may be considered as the generic 

 characters of soils, and determined by a very simple 

 process, that of washing the impalpable earthy matter 

 of the soil from the sandy portion, and by drying 

 and ascertaining their respective weights, when the 

 application of an acid shows whether it belongs to 

 the calcareous [limey] or siliceous [flinty] kind of 

 soil. 



It may be observed here, that this test only shows 

 the constituents of the soil, not its value as fertile or 

 unfertile; as the same constituents may be either 

 rich or poor, according as they are managed. 



The author next gives his analization of twelve 

 different sorts of soils used in his experiments, with 

 observations, as follow : — 



] . Poor siliceous sandy soil. 2. Siliceous sandy soil^ 



