A portion of this waste land, however, after having been pastured in this wretched manner for six or seven years together, may be ploughed up, when it will yield, perhaps, a poor crop or two of bad oats, or of some other coarse grain; and then, being entirely exhausted, it must be rested and pastured again as before, and another portion ploughed up, to be in the same manner exhausted and rested again in its turn.