PHYSICAL AND LITERARY. 75 



not be fufficient to give it a good cover- 

 ing. 



Fifthly^ We know by experience, that 

 couch-grafs, thiilles, and many other 

 hardy weeds, root themfelves in the 

 ground much deeper than three inches. 

 Thefe are not to be eradicated but by 

 deep ploughing ; and deep ploughing, once 

 begun, mud be continued ; for the under 

 ftaple left deferted is .foon filled with 

 weeds, which will deflroy what is fown 

 above them. 



Tke reafons given by thofe who prac- 

 tice lliallow ploughing, weigh not much 

 with me. The jirjl is, That the furface- 

 foil, enriched with dung and roots of 

 plants, which is by far the bed, will, by 

 deep ploughing, be buried, and a foil 

 worfe in quality be brought to the fur- 

 face. This inconvenience, I grant, will 

 follow, the firfltime the ground is plough* 

 ed deep ; but then this is but a tempo- 

 rary inconvenience, and will foon vanifh, 

 to give place to a folid improvement. The 

 rich furface-foil will not fuffer by being 

 laid at the bottom. But the bottom-foil 



brought 



