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SECTION II.

OF MANURES.

Manure denotes any substance or operationby which a soil is improved. To improve asoil is to render it capable of producing com,legumens, and the most useful grasses.

The substances principally used as manures,are chalk, lime, clay, sand, marl, gypsum, ashes,stable-dung, mucks, farm-yard dung, poundedbones, sea-weeds, sweepings of ditches, oldditches. Other manures or top-dressings, asthey are employed chiefly to promote thegrowth of vegetables, and not merely with aview of improving the soil, I omit.

The operations used to improve soils, arefallows, draining, paring and burning.

Of chalk, clays, and sand, we have alreadytreated.

Lime is a substance whose external charactersand mode of production are well known. Itdiffers from chalk and powdered limestonechiefly by the absence of fixed air, which isexpelled from these during their calcination.