ALTERNATION OF CROPS. 161 



Thus Mr. Vary's farm afforded him a nett annual profit 

 of about $13 OS per acre, over and above the amount 

 paid out for his family, and for farm-labor, &c., and Mr. 

 Harris's gave him a nett profit of about $17 16 per acre, 

 over and above his farm-expenses. 



A strong argument in favor of alternating crops may be 

 drawn from the alternations which are naturally going on 

 in forests, and in permanent meadows, and from the hab- 

 its of many plants, in sending abroad roots and stollens, 

 to establish a progeny in fresh, unexhausted soil. Thus, in 

 forest lands, the new growth seldom resembles altogether 

 that which has been felled. Hard wood frequently suc- 

 ceeds the pine and hemlock, while the pine and cedar, in 

 innumerable instances, succeed the primitive growth of 

 hard wood. The raspberry and the strawberry soon ex- 

 haust the soil of specific food, and Nature has endowed 

 these plants with the power of virtually changing their 

 location, by means of roots and stollens, and of annually 

 renewing their vigor from the resources of, to them, a 

 virgin soil. And even the delicate stoloniferous rose is 

 constantly changing its location in this way, and droops 

 and declines, in three or four years, if confined to a sin- 

 gle spot. With herbaceous plants which die and decay 

 where they grow, this disposition to change does not ex- 

 ist in so great a degree — because they annually return 

 again to the soil, and furnish the specific food for a new 

 generation of their species. So general is this law of 

 alternation, that it has become a well-settled opinion among 

 British farmers, that even our common biennial clover 

 should not be sown oftener than at intervals of six or eight 

 years upon the same field, its tendency, in common with 

 other plants, being to exhaust a specific property of the soil. 



We will close this essay with quoting, from Chaptal, 

 the principles which he lays down in regard to the alter- 

 nating system of husbandry, and the conclusion he draws 

 from them. His principles are — 



" 1. All plants exhaust the soil. 



''2. All plants do not exhaust the soil equally. 



" 3. Plants of different kinds do not exhaust the soil 

 in the same manner. 

 14* 



