2i8 Of Change of§ ? e. c i & s, Chap. XIV. 



has given to Vegetables no fuch Law of Meum and 

 *Tuum (g). 



If thefe Things were, as the Doctor affirms, why- 

 do Farmers lofe a Year's Rent, and be at the Charge 

 of fallowing and manuring their Land, after fo few 

 Crops ; fmce there are many more Sorts of Grain as 

 different from thefe and one another, as thofe are which 

 they ufually fow? 



They fti.ll find, that the firft Crops are beft ; and 

 the longer they continue fowing, the worft the laft 

 Crops will prove, be they of never fo different a Spe- 

 cies ; unlefs the Land were not in fo good Tilth for 

 the firft Crop as for the fubfequent •, or unlefs the laft 

 fown be of a more robuft Species. 



This Matter might be eafily clear'd, could we per- 

 fectly know the Nature of thofe fup'pofed unfuitable 

 (h) Particles ; but, in Truth, there is no more to 



be 



(g) A Charlock could not rob a Turnep, and ftarve it, more 

 than ieveral Turneps can do, unlefs the Charlock did take from 

 it the fame Particles which would nourifh a Turnep ; and unlefs 

 the Charlock did devour a greater Quantity of thai NourifhpsienC 

 than feveral Turneps could take. 



Flax, Oats, and Poppy, could not burn or wafte the Soil, and 

 make it lefs able to produce fucceeding Crops of different Spe- 

 cies, unlefs they did exhauil: the fame Particles which would have 

 nourifh'd Plants of different Species : For let the Quantity of 

 Particles thefe Burners take be never fo great, the following Crops 

 would not mifs them, or fuffer any Damage by the Want or Lofs 

 of them, were they not the fame Particles which would have 

 nourifhed thofe Crops, if the Burners had left them behind, 

 quiet and undifrurbed. Neither could Weeds be of any Prejudice 

 to Corn, if they did draw off thofe Particles only that fuit the 

 Bodies of Weeds, the reft lying all quiet and undifiurhed the while. 

 But conftant Experience fhews. that all Sorts of Weeds, more or 

 lefs, diminifh the Crop of Corn. 



[h) But we muft not conclude, that thefe Particles, which pafs 

 through a Plant (being a vaftly greater Quantity than thofe that 

 abide in it for its Augment), are all unfuitable, becaufe no one of 

 them happens to hit upon a fit Nidus : For fince the Life of Ani- 

 mals depends upon that of Plants, 'tis not unreafonable to 

 imagine, that Nature may have provided a confiderable Over- 

 plus 



