PRACTICAL AGRICULTURE. 31 



bencfical agency of the atmosphere during that period,) 

 we must, or ought, instead of tliat produce, — if the land 

 is to be restored to its original condition, — add to each 

 acre, every four years, 300 pounds of pearl ashes, or po- 

 tasii ; 440 of carbonate of soda ; 65 of common salt ; 

 240 uf quick lime ; 250 of sulphate of magnesia, that is, 

 Epsom salts ; 84 of alum ; and 260 bone dust ; making 

 1729 pounds of sohd saline matter. 



The fertility of a soil cannot remain long unimpaired, 

 unless we replace in it all those substances of which it 

 has been deprived. We could keep our fields in a con- 

 stant state of ferfiiity, by replacing, every year, as much 

 as we remove from them m the form of produce ; and, 

 be it remembered, that our cultivated corn plants, and 

 bulbous roots, are not like forest plants and trees : the 

 quantity of nutriment they require, and take up, to bring 

 them to perfection and perpetuate the race, is far more 

 than the unaided elements around them could supply. 

 "Wheat, for instance, as a natural production of the soil, 

 appears to have been a very small grass ; and the case 

 is still more remarkable with the apple and the plum. 

 The common crab seems to have been the parent of all 

 our apples. Potatoes and turnips, in their wild or nat- 

 ural state, are unfit for food ; and two fruits can scarce- 

 ly be conceived of more different in color, size, and appear- 

 ance, than the wild plum and the rich magnum bonum. 

 We have to contend, then, with two important differ- 

 ences : First, That wheat or turnips are not natural 

 productions; and, secoridly, That because they are not, 

 they drain or exhaust unassisted soil faster tlian the 

 wild plants of the forest ; nor will they thrive long, if 

 denied that assistance from artificial nutriment, which 

 nature cannot supply in suflficient quantity. 



It is evident, then, tliat an iucrease of fertility, and 

 consequent increase of crop, can only be expected when 

 we add more to the soil of the proper material, (and no 

 other,) than we take way. And soil will partially re- 

 gain itself by lying fallow : this is owing to atmospheric 

 action, and the conversion of the roots and stalks into 

 hunms. But though the quantity of decaying vegeta- 



