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water, impregnated with the different earths,and coal must have passed. In fact, Mr. Til-let's conclusion is contradicted by universal ex-perience.

2 °' In his 28th experiment, in which pow-dered limestone only was employed, the cornsown prospered exceedingly during the threeyears. To the cause mentioned, in treating ofthe 26th, I must add, that the limestone heused was that of St. Leu, which contains clay,and consequently silex and argill; it is so porousas to admit from 3-19thsto l-5th of its weightof water, as Mr. Brisson has shewn; and thusis easily decomposed. The coarse powder towhich it was reduced answered the same pur-pose as coarse silex; and the finer mightnourish the plants.

3°" In his 30th experiment he employed merepotter’s clay; the grain grew tolerably well thefirst year, but perished the second; on thethird it flourished most. It is hard to drawany specific conclusion from this experiment,for it is plain that if the texture were not muchlooser than that of clay, the corn could not growat all, as was the case in his 6th and 8th ex-F 2