y be Ve

Ne 401 reat halk, — It is hard

US Of

ASA(MANURE? 581

ed in any lime-ftone or marle, may be afcertained, by diffufing in water the re/- duum obtained by the analyfis(§ 13, p. 508*)—allowing it to fubfide a little, and gently pouring off the fluid parts from the coarfer fediment that fubfides to the bot- tom; for, as clay remains much longer fufpended in water than fand, it maybe thus feparated from the fand entirely;— when the water comes off clear, after having been left to fubfide a little, the re/r- duum may be evaporated to drynefs, and the lofs of weight it has fuftained by this opera- tion, denotes the quantity of clay.

This is rather a mechanical, than a che- mical procefs, which is called e/utriation.

§ 4.

It has been demonftrated above,§ 35, p. 484, that the quality of lime, confidered as acement, is greatly altered, by being mote or lefs perfectly calcined:—it’ may therefore be, on many occafions, of ufe to thofe who are concerned in building, to

* Obferve, it is unburnt lime-ftone, or marle enly, that

fhould be fubjected to this trial.

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