7*he Conchjion. 365 



any how cultivated in a different manner from 

 each other ; this would inform them alfo, 

 whether they fowed their Corn too thick or 

 too thin, by comparing the branchings and 

 extent of each root, with the fpace of ground 

 allotted it to grow in. 



And fince we find fo great a quantity of 

 air infpired and mixt with the fap, and 

 wrought into the fubftance of Vegetables, 

 the advantage of ploughing and fallowing 

 ground feems to arife not only from the 

 killing the weeds, and making it more mel- 

 low, for the (hooting of the roots of Corn ; 

 but it is thereby alfo the better expofed to 

 have the fertilizing, fulphureous, aereal, and 

 acid particles of the air mixt with ir, which 

 make land fruitful, as is evident from the 

 fertility which the fword or furface of land 

 acquires, by being long expofed to the air, 

 without any culture or manure whatever. 



We have ken many proofs of the great 

 quantities of liquor imbibed and perfpired 

 by plants, and the very fenfible influence 

 which different flates of the air had on their 

 more or lefs free perfpiration : A main in- 

 tention therefore to be attended to in the 

 culture of them, is to take due care, that 

 they be fown or planted in proper feafons 



and 



