334 



FARMERS' REGISTER. 



[No. 6. 



ineffectual for the purpose. Though no carbonate 

 of lime was present, it is certain that the soils 

 were neutral* — that is, that they contained in 

 some other combination enough lime to make let- 

 tile and absorbent soils. This, added to the quan- 

 tity of finely divided vegetable mould, and to the 

 fine clay forming nearly the whole earthy portion, 

 forms a soil that holds water like a sponge, and 

 must be peculiarly favorable to the growth of 

 grass.f This alone will suffice to accounUbr prai- 

 ries being formed on such soils — even if soils so 

 destitute of silicious parts are not (as I think to be 

 very probable, but do not know to be) as unfavor- 

 able to the growth of trees as are dry calcareous 

 soils. 



Practical application of the foregoing views, for 

 the improvement and better cultivation of prairie 

 lands. 



The calcareous prairie soils as well as all those 

 not calcareous, arc in general remarkably deficient 

 in sand, and would be far more valuable but lor 

 this deficiency. This excess of aluminous earth 

 (or pure clay) and not the calcareous matter, 

 causes the remarkable and troublesome adhesive- 

 ness of these soils. Is it also not likely that to this 

 defect of constitution is owing the great preva- 

 lence on prairie soils of the rust in cotton? It can- 

 not be caused by ihe calcareous earth, as two of 

 the specimens which were sent by Dr. Withers 

 from land peculiarly subject to produce that dis- 

 ease, contained no carbonate of lime. But wheth- 

 er or not the rust is one of the evil effects of a 

 great deficiency of sand, there are enough others, 

 to make it very desirable to remedy this defect in 

 soils otherwise so valuable. This might be done, 

 by the process of paring and burning the soil, as 

 is often done in England, when a new or sod-co- 

 vered field is brought from pasture into tillage. 

 The first preparing of prairie soil for tillage, by 

 the plough, is very laborious, and perhaps it. 

 would not be much more troublesome to pare and 

 burn the sod. This would be the most perfect 

 preparation for tillage; and the unrotted and re- 

 dundant vegetable matter would be converted from 

 a nuisance to a benefit; and the fine clay burnt to 

 brick-like particles, would form an artificial coarse 

 sand, serving to open and cure the previous close 

 texture of the soil. If the turf had already been 

 conquered by tillage, burning clay in kilns, as was 

 practised, for manure, in Europe, and by some in 

 the Atlantic states, would serve the same purpose 

 of providing a durable earthy ingredient acting 

 mechanically like coarse sand. By paring and 

 burning the surface of the soil, prairie lands might 

 also be made more healthy. It is true that they 

 are now considered generally healthy — the calca- 

 reous prairies especially. But though there may 

 be lime enough in most cases, to hold in combina- 



*Essay on Cal. Man. p. 22, 2nd Ed. 



| Mould [terreau] can absorb double its weight of 

 water without appearing moist; and after being dried, 

 it draws from the atmosphere in less than twenty-four 

 hours, a quantity of water, which may vary according 

 to the humidity of the atmosphere, from 80 to 100 per 

 cent, of its weight. — Berzelius — quoted in Essay on 

 Cal. Man. p. 81, 2nd Ed. 



tion the immense quantity of vegetable matter, 

 -till the latter must be greatly in excess in many 

 cases; and when so, must be rapidly decomposing, 

 after being ploughed, and evolve effluvia injurious 

 to health. If the prairie lands could by a miracle 

 be suddenly and completely deprived of all their 

 lime, the decomposition and waste in the air of 

 their putrescent matter would make them as sickly 

 as the western coast of Africa. 



Exceptions and apparent contradictions explained. 



Supposing these general causes to operate in the 

 formation of prairie lands, the least reflection will 

 show that their power and effects will be often 

 greatly modified by other circumstances. It is 

 well known that in prairie regions, the borders of 

 rivers and small streams are generally clothed 

 with trees. They are protected from the fires in 

 some measure by the dampness of the earth, and 

 because low bottoms are more sheltered from 

 winds. The river also is a secure barrier against 

 the flames, and therefore always guards one of its 

 banks, at least. Even the close neighborhood of 

 those exempted places, would diminish the vio- 

 lence of the flames: and spots abundantly calca- 

 reous, and lying high, might thus retain their wood 

 growth. It would require that the flames should 

 pass over a considerable space, and with a full sup- 

 ply of dry fuel, to acquire the requisite force and 

 rapidity for producing destruction. Thcrelbre the 

 vicinity of the wooded banks of a river would not 

 probably be changed from woodland to prairie, 

 by any fires driven by winds from the river. To 

 produce this effect, the winds which prevail in 

 dry seasons must drive the flames towards the ri- 

 vers, and downward between their forks. The 

 existing state of things on the borders of the Mis- 

 sissippi and Missouri (as I have been told) accords 

 well with this position. The north-west, winds 

 are generally dry, and blow with great violence; 

 and whenever their direction is between the forks 

 of streams and down their course, the prairie ex- 

 tends nearly or quite to the water's edge. But 

 streams running from the opposite slope of the 

 great valley, oppose the course and obstruct, the 

 effects of these fires — and the easterly winds 

 which would bear on them in like manner as to 

 direction, are generally accompanied by rain. 

 Therefore in the last situation, calcareous soils 

 may retain their growth of trees, and in the for- 

 mer, soils well constituted to nourish and support 

 them, may be brought to the state of poor prairie 

 land. 



If these general views are well founded, the 

 manner in which prairies are formed can no longer 

 be mistaken; and though a highly calcareous soil 

 is deemed the most general and the most import- 

 ant means, the theory serves as satisfactorily to ex- 

 plain the existence of prairies on various other sit- 

 uations, though the soil be not calcareous. 



Ancient prairie lands in the limestone region of 

 Virginia. 



In the foregoing observations I have limited the 

 total absence of prairies in the Atlantic states to 

 the eastern slope from the mountains to the sea, 

 and to all poor land even among the mountains. 

 In the rich limestone lands of Rockbridge county, 

 and perhaps on similar soils elsewhere, there cer- 

 tainly were prairies at an early period. When 



