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A mixture of marl and dung is still moreadvantageous *, because the dung supplies thecarbonaceous ingredient. But the marl mustbe used in the same quantity as if dung had notbeen applied, otherwise the operation must bemore frequently repeated. How the quantityof mail or other manure can be estimated, Ishall presently shew.

If marl cannot be had, a mixture of coarsesand and lime perfectly effete or extinguished,or chalk, will answer the same purpose, as itwill supply the defective ingredient, and openthe texture of the clay; so also sand alone, orchalk, or powdered limestone, may answer,though less advantageously. Lime alone ap-pears to me less proper, as it is apt to cake,and does not sufficiently open the soil.

Where these manures cannot be had, coalashes, chips of wood, burned clay, brick-dust,gravel, or even pebbles, are useful I; for all

* 4tli Young’s Eastern Torn-, 404.t 5 Bergman, 107; and Young’s Irish Tour, 249,129,136.

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