24 Of Pasture of Plants. Chap. Ill, 



And 'tis certain, that the Earth is not diverted or 

 robb'd of this Pabulum^ by any other Means, than 

 by actual Fire, or the Roots of Plants. 



For, when no Vegetables are iuffer'd to grow in a 

 Soil, it will always grow richer. Plow it, harrow 

 it, as often as you pleafe, expofe it to the Sun in 

 ITorfe-Paths all the Summer, and to the Froft of 

 the Winter-, let it be cover'd by Water at the Bottom 

 of Ponds, or Ditches ; or if you grind dry Earth to 

 Powder, the longer 'tis kept expofed, or treated by 

 thefe or any other Method poffible (except actual 

 Burning by Fire) i inftead of lofing, it will gain the 

 more Fertility. 



Thefe Particles, which are the Pabulum of Plants, 

 are fo very minute (a) and light, as not to be fingly 

 attracted to the Earth, if feparated from thofe Parts 

 to which they adhere (£J, or with which they are in 

 Contact (like Dull to a Looking-Glals, turn it up- 

 wards, or downwards, it will remain affixt to it), as 

 thefe Particles do to thofe Parts, until from thence 

 remov'd by fome Agent. 



(a) As to the Finenefs of the Pabulum of Plant?, 'tis not un- 

 likely, that Roots may infume no groffer Particles, than thofe on 

 ■\yhich the Colours of Bodies depend ; but to difcover the greatest 

 of thofe Corpufcles, S\r Ifaae Neivton think, it will require a Mi- 

 crofcope, that with fufficient Diitinctnefs can reprefent Objects 

 Five or Six hundred times bigger, than at a Foot Diitance they 

 appear to the naked Eye. 



My Microfcope indeed is but a very ordinary one, and when I 

 view with it the Liquor newly imbibed by a fibrous Root of a 

 Mint, it feeras more limpid than the cleareil common Water, nq- 

 t ing at all appearing in it. 



\b) Either Roots muft infume the Earth, that is their Pabulum, 

 as they find it in whole Pieces, having intire Superficies of thejr 

 own, or die fuch Particles as have not intire Superficies of their 

 o.vn, but want fome Part of it, which adheres to, or is Part of 

 the Superficies of larger Particles, before they are feparated by 

 Koots. The former they cannot infume (unlefs contained in 

 "Water) ; becauie they would fly away at the firft Pores that were 

 open : Ergo they muft inlumc the latter. 



