374 



AGRICULTURE. 



stances are known of land producing a succession 

 of good crops for many years, without fallowing or 

 manuring. On the summit of Baden Hill, in an ex- 

 posed and elevated situation, I have seen a luxuri 

 ant crop of barley growing on land that had borne 

 a succession of 20 preceding crops without manu- 

 ring. 



Such are the views which have generally pre- 

 vailed of late oh the subject of soils, and the ef- 

 fects of a due admixture of the various ingredients 

 composing them. Some writers, however, main- 

 tain, that the best possible mixtures do not directly 

 give fertility, but that this depends on the salts or 

 soluble organic matter contained in them ; and that 

 a due proportion of sand, clay, and lime forming 

 the soil, favours vegetation, by allowing the air, 

 moisture, and lime rapidly to dissolve organic mat- 

 ter, and yield it readily to the roots of plants. This 

 decomposed organic matter is called geine by Eer- 

 zelius, humin by Sprengel and other chemists. It 

 is, however, unimportant in what manner a due 

 proportion of the above elements acts in producing 

 fertility, the fact itself being the chief point to which 

 we wish to call attention. 



We have stated that Professor Hitchcock has 

 discovered the singular fact, that not one in thirty 

 of the soils of Massachusetts contain any calcare- 

 ous matter. This accounts for the great benefit 

 generally produced by the application of lime to 

 her soils ; for analysis shows that lime forms one 

 of the constituent parts of vegetables. One of the 

 most important benefits ever conferred by geology 

 upon agriculture, is the late discovery of the im- 

 mense advantages resulting from the application 

 of the green sand marl of New-Jersey to sandy 

 soils. We cannot present this matter in a better 

 light than by quoting some passages from a late 



* Bake well's Geology, p. 390. 



