1837] 



FARMERS' RKGISTER. 



277 



except from tlie quotations and references of this wri- 

 ter; and judging I'roin these, it would seem that th' y 

 have but very feebly maintained the opinions opposed 

 above, and which we have long believed to be both true 

 and highly important, to both the science and practice 

 of agriculture. This opinion, which we have brought 

 forward frequently in the Farmers' Register, and knew 

 not that it had yet been maintained by any other 

 j)erson, is, that the presence or absence, or vigor or 

 u-eahifss, of certain plants, furnishvery sure indications 

 of certain chemical ingredients or qualities being present 

 or absent in soils. It may be admitted that nearly all 

 plants may grow on soils of almost any chemical con- 

 stitution. Still, if there are but a few plants, which, 

 with a very great degree of certainty, will indicate 

 even a few of the many usual modifications and charac- 

 ters of soils, these facts, few as they may be, will be 

 highly useful, and the proper inferences from them 

 most valuable, though erroneous "inferences" may have 

 been drawn as to other such circumstances, and erro- 

 neous grounds for them stated. 



This writer, at the very time when condemning these 

 or similar views, furnishes new facts to sustain them. 

 He admits that the growth of heath always indicates a 

 peaty soil ; and though we have never seen a true peaty 

 soil, dry enough for tillage, (—and probably there is 

 not any, dry or wet, in Virginia, except the Dismal 

 Swamp — ) we are not the less certain that the heath, if 

 confined to peats, indicates also an acid soil, as correct- 

 ly as does sheep sorrel. Jf thus, as we maintain, a 

 very few, or even suppose only a single kind of plant, 

 points out this great class of acid soils — and shows, 

 that however these soils may differ in other respects, 

 they all agree in requiring calcareous manures to be 

 made profitable — then the value of that information is 

 as useful in practice, as if a thousand kinds of plants 

 served to give the same indications. But it is not only 

 that peaty and acid soils are pointed out so unerringly. 

 We incline to believe that the presence of calcareous 

 earth is clearly pointed out by some plants' growing 

 and thriving spontaneously — and it is certain that other 

 plants mark soil, if not absolutely calcareous, at least 

 neutral, or freed, by the admixture of a sufficiency of 

 lime, from the acid principle which prevails in, and de- 

 stroys the value of peat soils, and all the ridge, or other 

 naturally poor lands of lower Virginia, in their natural 

 state. Red clover may live, but cannot thrive on an 

 acid soil — and further, we believe that Ibme gypsum is 

 essential to its healthy existence, and that its vigorous 

 growth proves the presence of that earth in the soil, 

 as well as of enough lime in some other form to have 

 prevented the existence of free or hurtful acid. There 

 are plants which will grow only on a soil containing 

 enough salt to be hurtful to most other plants, and their 

 presence of course shows a very salt soil. 



But these ingredients of soils, which some plants so 

 unerringly point out, are such as act chemically. 

 Such as act mechanically, or at least principally so, do 

 not afford any such evidence of their presence, or quan- 

 tity. It is this distinction which the writer above does 

 not perceive, and for want of which his reasoning is 



confused, and does not reach the conclusion to which 

 his facts direct. 



All soils, unless absolutely barren, must contain 

 some small portion of each of the three principal 

 earths, viz: silex, (pure sand,) nluniina, (Hie jnire 

 matter of clay,) and lime, in some combination — 

 (though the usual form, carbonate of lime, is seldom to 

 be found in soils in this country, except in the western 

 prairie soils — ) and, therefore, all the three earths be- 

 ing present, either in large or small pro))ortions, in 

 every soil, of course, no plant can be supposed to in- 

 dicate 7)7-ecisp/(/ the presence or absence of either. The 

 abundance or scarcity of cither of these three earths is, 

 in most cases, indicated plainly enough by the plenty 

 or scarcity, the vigor or the feebleness, of many dif- 

 ferent kinds of plants, and especially in a state of na- 

 ture; but still, all such may live, and perhaps thrive, on 

 any of these soils. Further — so far as the earths 

 which compose soils act mechanically, the greatest abun- 

 dance or scarcity of either may not be proved by 

 the absence or presence, or feeble or vigorous growth, 

 of any particular plant — because the favorable or un- 

 favorable quality may be compensated for by some 

 other kind. Thus, every farmer knows that a clay 

 soil is the best for wheat, and that a great excess of si- 

 licioussand is so unfavorable to that crop, as generally 

 to forbid its being profitably raised. Nevertheless, 

 enough of calcareous and putrescent matters added to 

 very sandy soils, serve to produce very fine crops of 

 wheat. Of this, a. striking example was made by the 

 liming and vegetable manuring of the late Fielding 

 Lewis, on his very sandy land of Weyanoke, on James 

 River. For these several reasons, we can grant to the 

 writer so much as this — that the presence or even vigor 

 of particular plants will not unerringly point out whe- 

 ther either the silicious or the argilacious portion of a 

 soil is too great or too small — nor even whether the 

 calcareous part is small, or excessive. The sandy 

 (silicious) and argilaceous parts of soil act almost en- 

 tirely mechanically — and so does all the calcareous 

 earth, after enough has acted chemically to neutralize 

 or prevent the formation of the acid principles. There- 

 fore, the vegetable growth might not show any certain 

 difference between soils containing 5 per cent, and 50 

 per cent, of the pure matter of clay — or 50 and 90 per 

 cent, of that of sand — nor between 2 and 20 per cent, 

 of carbonate of lime — because all the quantities be- 

 tween these named extremes would act merely meohani- 

 cally. But yet there would be the most striking and 

 sure indications of the difference of composition be- 

 tween the soil containing even so little as one-thou- 

 santh part of carbonate of lime, and any other having 

 not enough lime to neutralize the acid of the .soil. In 

 this case, the action is not mechancal, but chemical — 

 and the smallest perceptible proportion of carbonate of 

 lime being present, shows that there is so much 

 superabundant, after its having performed all the che- 

 mical action necessar3^ In this manner, the soil con- 

 taining the smallest perceptible ingredient of carbonate 

 of lime, in a state of nature, would prevent the growth of 

 larch trees, (as stated above in the limestone soils of 



