A DISCOURSE

and composts whatsoever q . But to return to dust again. By the toil wehave mentioned, it is found that soil may be so strangely altered from itsformer nature as to render the harsh and most uncivil clay obsequious tothe husbandman and to bring forth roots and plants, which otherwise re-quire the lightest and hollowest moulds.

In other cases and affections, the earth may be likewise fertilized, asfrom without, so from within, by more recondite and central causes andagitations, which if in excefs, may be allayed with some feminine or othermixture; since oftentimes qualities too intense rather poison dry and cho-leric grounds, than conduce to their advantage, as we shall come to show;and that which makes a cold and moist ground fertile, will destroy thecontrary, as we see in the too free applications of salt; and therefore itrequires no ordinary dexterity to be able to direct where and what reme-dies are to be administered, since we find it the same in vegetable produc-tions as in the animal, where complexions should be suited ; for want ofwhich care, through avarice and other sordid circumstances, noble fa-milies themselves are many times rendered childlefs, which might elsehave multiplied and been perpetuated. To illustrate this by our presentsubject; we find, that a thin sifting, or sprinkling of ashes, has enrichedall the higher pastures, when, where strewed too thick, the ground be-came totally barren. Sometimes, again, defect of sufficient depth may because of sterility; and so it frequently happens, that the proper remedyof some hungry and shallow surface, is to superinduce and lay more earthupon it, and to find out the medium, by diligent trials of some degreesof depths in the same soil; but solitary, single, or over hasty experi-ments, before the earth be prepared by some of our fore-mentioned efsays,may prove discouraging and insufficient, as my Lord Bacon has oft ad-veptifed us.

i From accurate experiments made by Dr. Stephen Hales and others, it is certain thatthe leaves of plants draw from the air a considerable portion of aqueous fluid, in which alarge share of nutriment is minutely difsolved. This nutriment is certainly produced byputrid steams, generated upon the surface of the earth, which flying upwards, becomeblended and incorporated with the atmosphere. Showers of rain bring down these par-ticles again to the earth, and probably they are delivered to the mouths of the vegetablecreation in a more elaborated state, in consequence of their solution in the atmosphericvapours.