MANURES. 33 



now endeavoring to resuscitate those worn-out lands, which 

 ought never to have become impoverished. Of the same 

 character are most of the secondary bottoms on the Con- 

 necticut, the Scioto, the Miami, and other rivers. The first, 

 although under cultivation for more than two centuries, has 

 fully maintained its productiveness, the necessary result of its 

 minute subdivisions among intelligent farmers ; and the two 

 latter, if properly managed, are capable of perpetual fertility. 

 Although but a little more than half a century has elapsed 

 since these last have been subject to the white man, they 

 have, in too many instances, already been severely cropped. 

 The writer has seen fields, which he was assured have 

 yielded forty-seven large successive crops of corn, and ex- 

 clusively from their own resources. A more careful tillage, 

 however, is now becoming general. 



The lower alluvial bottoms that are frequently overflowed, 

 and thus receive large coatings of manures, which are fully 

 equivalent to the products taken off, are the only soils which 

 will permanently sustain heavy crops without the aid of 

 man. Such are the banks of the Nile and the Ganges, and 

 many of our own rivers, which by the overflowing of their 

 waters alone, have continued to yield large annual burthens ; 

 the two former, probably for more than 4,000 years; but 

 they are thus supported, at the expense of a natural drainage 

 of thousands of acres, which by this means, are proportion- 

 ally impoverished. Manures, then, in some form, must be 

 considered as absolutely essential to sustaining soils sub- 

 jected to tillage. 



In their broadest sense, manures embrace every material, 

 which if added to the soil, tends to its fertilization. They 

 are appropriately divided into organic and inorganic ; the 

 first embracing animal and vegetable substances, which have 

 an appreciable quantity of nitrogen ; the last, comprehending 

 only such as are purely mineral or earthy, and which in 

 general, contain no nitrogen. These characteristics are 

 sometimes partially blended, but they are sufficiently distinct 

 for general classification. 



Much pertinacity has been exhibited by some highly intel- 

 ligent minds, who should have entertained more liberal 

 views, as to the peculiar kinds of manures necessary to 

 support a satisfactory productiveness. We have seen that 

 Tull maintained, that the deepening and thorough pulveriza- 

 tion of the soil was alone sufficient to secure perpetual fer- 

 tility. But this crude notion, it is evident to the most super- 



