MANURES. 29 



CHAPTER IT. 



MANURES. 



While soils are permitted to remain in their natural state, 

 or if denuded of their original foliage and used only for pasture, 

 little or no change is perceptible either in their character or 

 productive powers. A slight change is however gradually 

 wrought in their texture and capacity for production, which is 

 fully revealed in the lapse of centuries. The elevated moun- 

 tain's side, and the steep declivities of hills, support a vege- 

 tation of more or less luxuriance ; and a portion of this, 

 together with the broken twigs, and even the wasting matter 

 of fallen trees, are carried down by the rains and become a 

 rich addition to the lower soils on which they ultimately rest. 

 Besides the vegetable matter thus annually removed from one 

 spot and accumulated upon another, many of the fertilizing 

 salts, which the action of the roots, or exposure to the atmo- 

 sphere has rendered soluble, and the fine particles of earth 

 which the alternations of heat and frost, of rain and drought 

 have reduced to dust, are also washed out of the higher soils 

 and deposited on the plains and vallies below. Such, doubt- 

 less, was once the condition of those secondary bottom-lands, 

 which for ages probably, received the rich deposits from 

 other soils, but whose present situations, elevated beyond 

 even the extraordinary rise of the rivers whose course is near, 

 show some radical alteration of their respective levels, by 

 which the latter no longer contributes to their fertilization. 



These soils being well stored with the food of plants, and fre- 

 quently to a great depth, will bear large successive crops for 

 a long period ; and they have, in many instances, been treat- 

 ed by their first occupants as if they were inexhaustible. Of 

 this description were the James river and other alluvial lands 

 in Virginia, some of which were continued in uninterrupted 

 crops of corn and tobacco for more than a century without the 

 addition of manures. But they have long since become ex- 

 hausted, and the more careful planters are now endeavoring 

 to resuscitate those worn-out lands, which ought never to 



