crops of corn, tares, and on young turnips; and being an active manure, it never fails in producing very beneficial effects. Being applied in March and April, it seldom comes under the valuer's notice, as one crop consumes the value of all such transient manures as do not produce the effect by being mixed in the soil. When applied to protect young turnips from the fly, it is supposed to act at the same time as a manure for the turnips; and in that case one fourth of its substance is thought to be left in the soil, if the turnips have been eaten on the ground by sheep; but when drawn, no valuation is allowed.

ON MARL.

Marl is a kind of soft fossil earth, used as a manure on sandy, gravelly, and light soils, in countries where it can be procured. It is chiefly composed of clay and carbonate of lime, and is valuable according to the

calcareous and oily qualities it contains. The solubility, and the property of effervescence with acids, denote the quality of marl; and it is found of various colours, blue, grey, red, and yellow,-of which the first and last are most valuable. About 40 cubic yards are generally allowed for manuring an acre, which will support a rotation of four crops, and grass a few years longer. The quality of the marl, and the customary course of cropping, determine the length of these terms.

No valuation is allowed for marl got on the farm where it is used, -the out-going tenant being paid for expenses only; but where it is brought from another property, the price of the material and the usual expenses are allowed as for dung or any other

manure.

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ON BURNT EARTH OR CLAY.

This substance is sometimes used as a manure, and is obtained by burning clay

found on the farm, and is valued according to the labour and expenses that have been incurred. Full tillage is allowed when applied on fallow or turnips, and valued before producing a crop; and half tillage after one corn crop; and after two crops, the valuation ceases.

Burnt earth and burnt clay differ much: the former contains vegetable matter; and the advantage of burning the latter is very questionable, unless lime and vegetable matter be burnt with it. Some writers reckon it a topical remedy; and when burnt alone, that dung or some other manure, containing vegetable matter, should be applied at the same time. In fixing the value, the quality of the constitutional ingredients, and the mode in which the incineration has been performed, must be borne in mind: if the material be found on the farm, the cost of labour and fuel is only allowed; but if brought from other property, the cost of material and of carriage is added.

ON BONES AND BONE DUST.

Bones consist chiefly of phosphate of lime, and decomposible animal matter, and are used as a manure on fallows, grass lands, and for turnips, but are found not suitable for clays. A valuation of six years is allowed for them when laid on pasture, and four years on grass successively mown; and in some places, ten years for pasture, and six years on mown grass; and four corn crops, or six years, on arable lands. In other places a longer period is allowed. After one white crop has been taken, two thirds of the prime cost and expenses are allowed; after two white crops, one third is awarded; and after three years, the valuation ceases.

On the supposition that bone dust must be sooner expended than the crushed bones themselves, it has been thought reasonable to allow one tillage more for the latter than for the former; and the dust is accordingly subject to the same valuation as dung, and

determined by the four years' course of

cropping.

ON COMPOSTS.

Composts are mixtures gathered together in order to form a manure, and are generally composed of earths, clays, sand, and vegetables, with a suitable mixture of lime: if intended for grass lands, the heaps should be frequently turned, and well broken and pulverised, that the particles may soon get mixed and incorporated with the lime in the heap, and afterwards with the sward: the application, when properly performed, is attended with much success, and enriches the herbage much more than if the ingredients had been applied singly in the original state.

In making valuation of composts, it is necessary to ascertain where the materials have been procured: if brought from a distance, the cost of material and of carriage is allowed, and also of mixing and spreading;