EARLIEST OPINIONS OF SOILS. 419 



closing must agree with me in ascribing to this cause the natural 

 fertility of the most valuable [wood] land. 



"As to manuring, there are but few farmers who have not, like 

 me, experienced complete disappointment in endeavouring to im- 

 prove land so little favoured by nature. In the usual method of 

 summer manuring, by movable cow-pens, the most negligent far- 

 mers give the heaviest covering, by suffering 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 ma- 

 nures, 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 observations, it appears evident that calcareous 

 earth constitutes a part of every soil rich in its natural state, and 

 that whenever a soil is entirely or nearly deficient, it never can be- 

 come 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 watercourses 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 produced by calcareous earth in the 

 colour and texture of soil, and in a field of an hundred acres, all of 

 the same dark-coloured mellow soil, shells may be seen in only a 

 few detached spots, 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 con- 

 tinual 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 



