These Plants might, with much less Difficulty, have distinguish’d the mineral Matter from the vegetable Matter, than they could distinguish the different Particles of vegetable Matter from one another, and must have been very unwise to chuse out the Nitre (their Poison) from the Water and Earth, and to leave the vegetable Particles behind; none of which could be so improper to them as the Nitre. It may perhaps be objected, that such like pernicious Matter kills a Plant by only destroying its Roots, and by closing the Pores; which prevents the Nourishment from entering to maintain its Life; and that such Matter doth not itself enter to act as Poison upon the Sap, or upon the Vessels of the Body, or Leaves: But it plainly appears that it doth enter, and act as Poison; for when some of the Roots of a Mint, growing in Water, are put into salt Water, it kills the whole Plant, although the rest of the Roots remaining in the fresh Water were sufficient to maintain it, if the other Roots had been cut off at the Time they were removed into the Salt Water; and also all the Leaves, when dead, will be full of Salt. Or if the Juice of wild Garlick-seed be made use of instead of the salt Water, it will have the same Effect; and every one of the Mint-leaves will have a strong Taste of Garlick in it. Here then he says plainly, That each Plant receives the terrestrial Matter in gross, both suitable and unsuitable to its Nature, retains the suitable Particles for its Augment, and the unsuitable lets pass through it. And in another Place he says they are exhal’d into the Atmosphere. And this will appear to be the true Case of Plants; and directly contradicts what he advances, in saying, ‘That each Sort of Grain takes forth that peculiar Matter that is proper for its own Nourishment. First, the Wheat draws off those Particles that suit the Body of that Plant, _the rest lying all quiet and undisturb’d the while_. And when the Earth has yielded up all them, those that are proper for Barley, a different Grain, remain still behind, till the successive Crops of that Corn fetch them forth too; and so the Oats and Pease in their turn, till, in fine, all is carried off.’ In the former Paragraph he says, each Plant _lets pass through it_ the rest of the Particles that are not suitable to its own Nature. In the latter Paragraph he says, That each _leaves_ the unsuitable _all behind_ for another Sort; and so on. Both cannot be true. If the latter were true, Change of Sorts would be as necessary as it is commonly thought. But if the former be true, as I hope to prove it is, then there can be no Use of changing of Sorts in Respect of different Nourishment.