278 



CALCAREOUS MANURES— APPENDIX. 



minous, or argillaceous earth, and decomposed vegetable matter — and this 

 is precisely the composition of every specimen of prairie soil which I have 

 examined, and which was not highly calcareous. Examples of some such soils 

 are presented in the foregoing list. The soils contained very little silicious 

 earth, and that little so tine as only to be made sensible to trial between the 

 teeth. The ordinary mode of separating silicious from aluminous earth, by 

 agitation in water, was quite inefiectual tor the purpose. Though no car- 

 honate 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 fer- 

 tile and absorbent soils. This, added to the quantity of finely divided vege- 

 table mould, and to the fine clay composing nearly the whole earthy portion, 

 forms a soil that holds water like a sponge, and must be peculiarly favora- 

 ble to the growth of grass.f This alone will suffice to account for prairies 

 being formed on such soils — e.ven if soils so destitute of silicious parts are 

 not (as I think to be very probable, but do not know them to be) as unfavo- 

 rable to the growth of trees as are dry calcareous soils. 



Practical application of tlie foregoing vievJs,for the improvement and better 

 cultivation of prairie lands. 



The calcareous prairie soils, as well as' all those not calcareous, are in 

 general remarkably deficient in sand, and v/ould be far more valuable but for 

 this deficiency. This excess of aluminous earth (or pure clay) and not the 

 calcareous matter, causes the remarkable and troublesome adhesiveness of 

 these soils. Is it also not likely that to this defect of constitution is owing 

 the great prevalence on pi:airie soils of tiie rust in cotton ? It cannot be 

 caused by the calcareous earth, as two of the specimens which were sent 

 by Dr. Withers from land peculiarly subject to produce that disease, con- 

 tained no carbonate of lime. But whether 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 other v/ise so valuable. This 

 might be done by the process of paring and burning the surface, as is often 

 done in England, when a new or sod-covered 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 redundant 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, burn- 

 ing 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 ihe surface of the soil, prairie lands might also be made more 

 healthy. It is true that they are now considered generally healthy — the cal- 

 careous prairies especially. But though there may be lime enough, in most 

 cases, to hold in combination the immense quantity of vegetable matter, still 

 the latter must be greatly in excess in many cases ; and when so, must be 

 rapidly decomposing, after being ploughed, and evolve effluvia injurious 



* Essay on Cal. Man. p. 44. 



t Mould [lerreau] 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.— £e)-2ditts— quoted in Essay on Cal. Man. p. 169, 



