152 ON THE FOOD OF PLANTS. 



year, it was planted with potatoes without ma- 

 nure, and the crop averaged fourteen tons per 

 acre. The seventh year, it was sown again with 

 wheat, without manure, and it produced up- 

 wards of tliirty-two bushels per acre. 



And to show the beneficial eifects of top- 

 dressing, I shall also state that about this time, I 

 took possession of a field of pasture land of about 

 twenty acres, a strong yellow or foxy clay ; it 

 lay on the side of a hill, and was very wet and 

 poachy, particularly during winter ; had been ge- 

 nerally cut for hay, although it seldom produced 

 more than three-fourths of a load per acre, and 

 this not until the end of July. I drained it by 

 cutting a ditch at the upper side, deep enough 

 to get below the stratum of clay, which in some 

 places was upwards of five feet, turning the 

 water down the sides, and gave it a top dress- 

 ing of scavenger's manure, the cleaning of the 

 town streets ; and the year after, it produced me 

 a load and a half per acre, in the middle of 

 June; and a second crop, of three-fourths of a 

 load, the beginning of September ; and this it 

 continued to do, varying a little, more or less, 

 according only as the seasons were wet or dry. 



And to shew the effect of dung buried deep ; 

 the following instance maybe sufficiently strong. 

 I had noticed a field at Wickham in Kent, 



