CALCAREOUS MANURES— APPENDIX. 247 



is sufficiently proved by poor wood-land. This has had the benefit of inclos- 

 ing for perhaps thousands of years, and is yet miserably poor. It may 

 be said that leaves are not to be compared in value to grass or weeds ; but 

 sui"ely leaves ought to improve as much in a thousand years, as grass or 

 weeds in twenty. Besides, it is well known, that leaves taken from this 

 very land, and applied elsewhere, have produced much benefit ; and the 

 advocates of inclosing must agree with me in ascribing to this cause the 

 natural fertility of the most valuable land. 



" As to manuring, there are but fe\Y farmers who have not, like me, expe- 

 rienced complete disappointment in endeavoring to improve land so little 

 favored by nature. In the usual method of summer manuring, by movable 

 cow-pens, the most negligent farmers give the heaviest covering, by suffer- 

 ing their pens to remain stationary sometimes six or eight weeks. . I have 

 known the surface in this manner to be covered an inch thick with the 

 richest of manures, and yet, after going through the same course of crops 

 and grazing with the adjoining unmanured land for six years, it could not be 

 distinguished." ******* * * * 



"If any one principle should be always found in one kind of soil, and as 

 invariably absent in the other, we might reasonably infer that that was the 

 cause of fertility or barrenness. Judging from my very limited observa- 

 tions, it appears evident that calcareous eari(/t constitutes a part of every 

 soil rich in its natural state, and that whenever a soil is entirely or nearly 

 deficient, it never can become rich of itself, and if made so by heavy doses 

 of dung, will soon relapse into its former sterility. 



" Let us observe how facts coincide with this opinion. The lower part 

 of Virginia is generally poor ; narrow stripes along the rivers and smaller 

 water courses are nearly all the high lands that are valuable, and in this 

 class, exclusively, shells are seen so frequently, and in such abundance, that 

 it seems highly probable that they are universally present, but so finely 

 divided as not to be visible. When we know the change jiroduced by cal- 

 careous earth in the color and texture of soil, and in a field of an hundred 

 acres, all of the same dark-colored mellow soil, shells may be seen in only 

 a ^ew detached spots, yet we cannot but attribute the same effects to the 

 same cause, and allow calcareous matter to be present in every part. 



"The durable fertility of land which contains shells in abundance is so 

 wonderful, that I should not dare to describe it, were not the facts supported 

 by the best authority. The calcareous matter for ages has been collecting 

 and fixing in the soil such an immense supply of vegetable matter, that near 

 two centuries of almost continual exhaustion have not materially injured 

 its value. I have seen fields on York, James, and Nansemond rivers, now 

 extremely productive, which are said to have been under cultivation for 

 thirty and forty years, without any aid worthy mentioning, from rest or 

 manure. 



" The same cause operates on low lands, formed by alluvion, and situated 

 on streams accustomed to overflow. Such land is, with very few exceptions, 

 of the first quality ; and it is made so by the calcareous matter which the 

 currents must necessarily convey from the strata of marl through which 

 they pass ; and which being intimately mixed with sand, clay, and vegeta- 

 ble matter, is sufficient to form the finest and deepest soil. All the rich low 

 grounds which I have had an opportunity of observing, have marl on some 

 of the streams which fall into them, and I have not heard o{ any on those 

 few which are poor. Not a solitary instance of shells being found in poor 

 land of any description has come to my knowledge. 



" If these premises are correct, no other conclusion can be drawn from 

 them but that a proportion of calcareous earth gives to soil a capacity for 



