Chap. XIV. Of Change ofS pecies, 217 



nnfuitable to its Nature, retains the fuitable Particles 

 for its Augment, and the unfuitable lets pafs through 

 it. And in another Place he lays they are exhal'd 

 into the Atmofphere. 



And this will appear to be the true Cafe of Plants ; 

 and directly contradicts what he advances, in faying, 

 « That each Sort of Grain takes forth that peculiar 

 f Matter that is proper for its own Nourimment. 



* Firft, the Wheat draws off thofe Particles that fuit 



* the Body of that Plant, the reft lying all quiet and 



* undifturb'd the while. And when the Earth has 

 ' yielded up all them, thofe that are proper for Bar- 



* ley, a different Grain, femaii hind, till the 

 c fucceflive Crops of that Corn fetch c tern forth too; 

 « and fo the Oats and Peafe in their turn, till, in fine, 



* all is carried off.' 



In the former Paragraph he fays, each Plant lets 

 pafs through it the reft of the Particles that are noc 

 fuitable to its own Nature. In the latter Paragraph 

 he fays, That each leaves the unfuitable all behind for 

 another Sort; and fo on. 



Both cannot be true. 



If the latter were true, Change of Sorts would be 



as neceffary as it is commonly thought. But if the 



former be true, as I hope to prove it is, then there 



can be no Ufe of changing of Sorts in Refpect of 



' different Nourishment. 



If in this Series of Crops each Sort were fo juft 

 as to take only fuch Particles, as are peculiarly pro- 

 per to it, letting all the reft alone to the other Sorts 

 to which they belonged, as the Doctor imagines ; 

 then it would be equal to them all, which of the 

 Sorts were fown firft or laft : But let the Wheat be 

 fown after the Barley, Peafe, and Oats, inftead of 

 being fown before them, and then it would evi- 

 dently appear, by that ftarv'd Crop of Wheat, 

 either that fome or all of thofe other Grains had 

 violated this natural Probity, or elfe that Nature 



has 



