40 CALCAREOUS MANURES-THEORY. 



much larger part of all this region— and far more strange is it that the same 

 deficiency should extend to such rich soils as some that will be here cited. 

 The following specimens, taken from well known and very fertile soils, 

 were found to contain no calcareous earth. Many trials of other rich soils 

 have yielded like results— and, indeed, I have never found calcareous earth 

 in any soil below the falls of the rivers, in which, or near which, some par- 

 ticles of shells were not visible. 



1. Soil from Eppes' Island, which lies in James-river, near City Point; 

 light and friable (but not silicious) brown loam, rich and durable. The sur- 

 face is not many feet above the highest tides, and, like most of the best river 

 lands, this tract seems to have been formed by alluvion many ages ago, but 

 which may be termed recent, when compared to the general formation of 

 the tide-water district. 



2. Black silicious loam from the celebrated lands on Back-river, near 

 Hampton. 



3. Soil from rich land on Pocogon-river, York county. 



4. Black clay vegetable soil, from a fresh-water tide marsh on James- 

 river— formed by recent alluvion. 



5. Alluvial soil of first-rate fertility above the falls of James-river— dark 

 brown clay loam, from the valuable and extensive body of bottom land 

 belonging to General J. H. Cocke, of Fluvanna. 



The most remarkable facts of the absence of calcareous earth are to be 

 found in the limestone soils, between the Blue Ridge and Alleghany moun- 

 tains. Of these, I will report all that I have examined; and none contained 

 any calcareous earth, unless when the contrary will be stated. 



Before the first of these trials was made, I supposed (as probably most 

 other persons do) that lime-stone soil was necessarily calcareous, and in a 

 high degree. It is difficult to get rid of this impression entirely— and it 

 may seem a contradiction in terms to say that a limestone soil is not calca- 

 reous. This I cannot avoid. I must take the term lime-stone soil as custom 

 has already fixed it. But it should not be extended to any soils except 

 those which are so near to lime-stone rock, as in some measure to be there- 

 by affected in their qualities and value. 



1 to 6. Lime-stone soils selected in the neighborhood of Lexington, Vir- 

 ginia, by Professor Graham, with the view of enabling me to investigate 

 this subject. All the specimens were from first-rate soils, except one, which 

 was from land of inferior value. One of the specimens, Mr. Graham's de- 

 scription stated to be " taken from a piece of land so rocky [with lime-stone] 

 as to be unfit for cultivation, at least with the plough. I could scarcely 

 select a specim.en which I would expect to be more strongly impregnated 

 with calcareous earth." This specimen, by two separate trials, yielded 

 only one grain of calcareous earth, from one thousand of soil. The other 

 five soils contained none. The same result was obtained from 



7. A specimen of alluvial land on North-river, near Lexington. 



8. Brown loam from the Sweet Spring valley, remarkable for its extra- 

 ordinary productiveness and durability. It is of alluvial formation, and be- 

 fore it was drained, must have been often covered and saturated by the 

 Sweet Spring and other mineral waters, which hold lime in solution. The 

 surrounding high land is of lime-stone soil. Of this specimen, taken from 

 about two hundred yards below the Sweet Spring, from land long culti- 

 vated every year, three hundred and sixty grains yielded not a particle of 

 calcareous earth. It contained an unusually large proportion of oxide of 

 iron, though my imperfect means enabled me to separate and collect only 

 eight grains, the process evidently wasting several more. 



About a mile lower down, drains were then making (in 1826) to reclain* 



