M. De Gasparin on the Classification of Soils. 91 



Upon the whole, therefore, we establish the subordination of 

 the agricultiu'al characters which ought to be considered in soils, 

 in the following method : — 1*^, The appropriation of soil to 

 plants ; 2d, the tenacity of the ground ; and 3(/, the aptitude 

 of the soil to receive certain kinds of manures or improve- 

 ments. 



§ III. Primary Classification of Soils after their appropriation to 

 jmrticular cultures. 



The Cerealia are every where throughout Europe the basis 

 of rural operations. They succeed more or less in all the 

 soils which supply them with a firm support, and wliich at the 

 same time allow the air to penetrate to their roots ; ranging 

 from sandy soils which do not contain less than /(fy of sandy 

 or rocky materials, to stiff clays, provided that the soils do 

 not contain i%o of sea-salt, or any sulphate of iron. The 

 soils or pure mould are also excluded from this kind of cul- 

 tivation, from the defective cohesion of their elements, and 

 their frequent change of volume. Allowing for these excep- 

 tions, there ai'e three principal groups of soUs. 1*/, The sali- 

 ferous ; 2cl, the sandy, which contain even as much as fg of 

 sand or of rock ; and, 3rf, organic soils, which contain ^ of 

 mould. This division, it should be remarked, agrees not only 

 with the results of the mineralogical study of the soil, but also 

 with its tenacity ; and hence it is perfectly natural. 



There remains, moreover, a great number of soils in which 

 wheat thrives, when they contain, besides, a sufficient quan- 

 tity of organic matter ; but they are not all equally favourable. 

 For its successful cultivation, those which contain only silex 

 and clay must have lime added, a principle without which 

 they wUl scai'cely yield any return. As soon as this is sup- 

 pUed, their product immediately increases in a remarkable 

 manner, to the extent of a fourth, a third, and even a half. 

 The vegetation of the Cerealia, therefore, indicates a grouping 

 which sul)divides lands into soils containing carbonates (of lime 

 or of magnesia, the latter supplying the place of the former), 

 and into silico-argillaceous, or clayey soils, which do not con- 

 tain carbonate of lime or of magnesia. Hence the agricul- 

 tm'al principle is, in its turn, in agreement with the principle 



