2J^0 CALCAREOUS MANURES-APPENDIX. 



bonate of lime* — and therefore the land must have been brought to the 

 prairie state slowly and with difficulty, under the long continued operation 

 of annually repeated fires — and their intermission for a few years was 

 enough to enable the soil to again throw up a new growth of young trees. 

 These appearances were so well known in Rockbridge, that some very in- 

 telligent persons, born and reared in that county, have thence inferred that 

 the wood cover of our country was every where comparatively recent, 

 and that at some former and not very remote time, every part of this con- 

 tinent had been without trees; which is an example of very erroneous rea- 

 soning from particular to general facts. 



Of soils rendered barren by excess of calcareous mutter -and the fertility 

 produced on them by irrigation. 



The " bald prairies" of Alabama present the only known cases in the 

 United States of bodies of land so highly calcareous as to be thereby 

 lessened in productiveness. This effect will increase as exhausting culti- 

 vation shall lessen the vegetable ingredients of the soil ; and probably 

 (under a continuation of such tillage) the barren spots will extend widely 

 into what now form their fertile margins - The quantity of vegetable matter 

 accumulated in the highly calcareous prairie soils is now so great, that a 

 very long course of exhausting tillage will be borne before sterility can be 

 produced. Nevertheless, however remote may be that result, its occur- 

 rence is not the less sure, if exhausting tillage is pursued. Similar to our 

 rich prairies probably was the original state of the now poor chalk downs 

 of England, the almost barren plains of "Lousy" Champagne in France— 

 and some of the still more hopeless deserts of Asia and Africa. The fur- 

 nishing or retaining of a sufficiency of vegetable matter would cure this 

 kind of barrenness, and more easily will prevent its extension beyond its 

 present limits, in our own new country. In other countries, water alone, 

 used for irrigation, has had the effect of making highly fertile, and keeping 

 it so, land so calcareous that it would otherwise have been altogether bar- 

 ren. Many facts of this kind may be gathered from the writings of travel- 

 lers; but their notices are very slight, and merely incidental, as unfortu- 

 nately, none who have viewed and described these lands, possessed any 

 agricultural knowledge. Some of these passages will be quoted. In some 

 far remote future time, perhaps the overflowing wells of southern Alabama, 

 may be used to irrigate the excessively calcareous soils, and to retain or 

 restore their fertility. 



Denon, in his Travels in Egypt, (Am. Ed. vol. ii., p. 4,) when at Siut, or 

 Lycopolis, 2^ degrees south of Cairo, speaks thus of the Lybian range of 

 mountains. "I found this, as I had supposed, a ruin of nature, formed of 

 horizontal and regular strata of calcareous stones more or less crumbling, 

 and of different shades of whiteness, divided at intervals with large ma- 

 millated and concentric flints, which appear to be the nuclei, or as it were, 

 the bones of this vast chain, and seem to keep it together, and prevent its 

 total destruction. This decomposition is daily happening by the impression 

 of the salt air, which penetrates every part of the calcareous surface, de- 

 composes it, and makes it, as it were, dissolve down in streams of sand, 

 which are at first collected in heaps at the foot of the rock, and are then car- 

 ried away by the winds, and encroaching gradually on the cultivated plains 

 and the villages, change them into barrenness and desolation." The Lybian 

 chain of mountains which runs nearly parallel with the .MIe, there ap- 



' Essay on Calcareous Manures, p. 31. 



