I7 6 A TREATISE ON THE CONNECTION OF 



over-shadowing the ground. Were an experiment on 

 some rich infield land made, by preventing it from being 

 cropped or eaten down by cattle for a certain number 

 of years, a thickness of some inches of turf or peat would 

 he superinduced ; and the land would not again be fitted 

 for .the production of grain, or sweet pasture grasses, 

 without paring and burning, or the application of lime 

 or saline substances, to act upon, or dissolve part of the 

 accumulated vegetable matter. Hence it is that ground 

 should contain only a certain proportion of vegetable 

 anatter to constitute it rich and fertile mould. 



A considerable extent of ground, of this description, 

 .(formerly under a high state of cultivation) 'has been ob- 

 served in some of the southern Counties of Scotland, the 

 cultivation of which ground had probably been dis- 

 continued from -the frequent wars between the two 

 nations. 



By fallowing, and the. application of lime, such a soil 

 may be made fit for. the production of grain. By deep 

 ploughing, .part . of the ,under-stratum, containing less 

 vegetable matter,. may be brought up and mixed with 



the 



