Rotations and Changes of Crops defended. 255 



table manure, has not always occurred. For, (although 

 time has brought forward wiser convictions,) it has not 

 been singular, in our new countries, to remv)ve barns 

 and stables, from sites deemed to be incumbered by 

 dung-heaps ! 



Of constant and long successions of Indian corn 

 crops, in sundry places, and particularly on rich bot- 

 toms ; especially on those subject to overflows, which 

 bring along with them, and deposit, accessions of new 

 soil ; I have heard accounts, the most favourable to 

 the idea of perpetuating the same species of crop. 

 Probably the culture of this plant, never occupying 

 exactly the same place in the hills of succeeding years, 

 keeps down weeds, in greater or less degrees, and en- 

 ables it to thrive the longer, like grain sown accord- 

 ing to TuWs drill husbandry, on the same field. — Pe- 

 culiarly on rich bottoms ; which are commonly abun- 

 dantly fertile. These may furnish more of the speci- 

 fc pabulum, than soils of common texture afford ; if 

 there be any well founded evidence of this doctrine ; 

 for I vouch theories with hesitation. — But I have no 

 more idea of thus establishing a general principle, or 

 shaking one well fixed ; than I have of determining 

 the duration of human life, by the longevity, or strength 

 of constitution, of some men : much less would I 

 adopt as a rule, the instances of some, who live long, 

 under the practice of inveterately bad habits. General 

 results, and common calculations, are not impugned 

 by such examples. 



It is safer and better, to follow methods generally 

 approved ; than to suffer ourselves to be carried away 

 from them ; because, in some instances, contrary prac- 



