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ing too loose and porous for holding the roots of plants, or waterto support them, by overliming, which does not appear to havebeen occasioned by the causticity of the lime. Fields in Stor-mont and Strathmore have lost all cohesion, and bear no grass,by the excessive use of shell marl, which is always in a car-bonate state. * Carbonate of lime, • after remaining in a dampsituation, like decayed plaster, crumbles into dust, and not onlyrefuses to cohere, but lies very loose 1 and open. What the na-ture of this chemical change is, does not appear to have been ex-amined ; but the fact is certain. It is this trait in the characterof lime which causes the faulty porosity in the soil. As it is ve-ry generally admitted that lime yields scarce any direct food toplants, but only adapts the soil and its contents for their nourish-ment,—as moderate quantities have been tound to answer thispurpose,—and very large quantities or too frequent repetitions, insome instances, to defeat it, it is surely most prudent to keepwithin moderate bounds, till longer experience have establisheda more certain standard for soils of different qualities.
With regard to the second question, some insist that landshould have a large dose of lime at once; that smaller quantitiesgiven at different times produce no effect, and are altogetherthrown away. Others argue, that the main use of lime being asan ingredient to improve the construction of the soil, it can on-ly serve that purpose by being intimately mixed with the otheringredients, and that this mixing can be best effectuated by re-peated applications. The argument on both sides rests uponthe supposition of lime being an unconsumable substance; andthe diversities of soil are not taken into consideration. Butthough lime carbonated be insoluble in water, it forms, as hasbeen said, with some acids, soluble salts, and may also com-bine with the carbon and hydrogen of putrefying bodies. Suchof these soluble compounds as are not carried up into the or-gans of growing plants, must be washed away in rains; and thusthe proportion of calcareous matter be continually diminishing.Besides, the insoluble salts of lime, though they remain in thesoil, may not be so useful ingredients as the carbonate, sinceall salts have qualities different from those of the substances ofwhich they are compounded. The calcareous matter must there-fore be always diminishing, by the abstraction both of solubleand insoluble salts ; but experience has not yet established anyrule to judge at what rate this consumption proceeds, or whenit may be requisite to restore what has been wasted. As to thediversities of soil, the mixture of iime tends to separate the par-ticles of strong clays for a time; but these particles have such atendency to coalesce as often as they are soaked with water, thatrepeated applications of lime to separate them anew, may often