m^pt^fiy prinqipj^s ^n the cpurse of the i^P^uiligideceiBpa^f 

 l(j^po^,, „X'ierefo(:^, ?t i3.^e*rer the; facts, that tfwo years' crop$. 

 cu; p|il,tiii;e, for market|Or r,empyal, would require one year's 

 grpvyth of some manuring crop to replace, and toimainitaiq 

 pfjdipinished, or, increasing the productive power of, the fi4ldx 

 ^he> ppprestji and also the cheapest, of :Such,|iUsin|wBg-iQirc^|- 

 ]^iii be .the, natural or " \folunteer" growth of weedsj. cq 

 |jiji,(^ Jeft cultivated, and not grazed; a:nd the Ixfet qf i*ll 

 :^^11 pe.furnished in the whole prodijictof a broadoast sown 

 Md] entire crop of your own most fertilising and valuably 

 ^pl^ peas. I . ) ,^r ■ v-ti:)(rjnulB -loil!" oJa-odl hylihs 

 •^^j" Thus, of each manuring crop, (as of all others), ore/ 

 the. fertilizing niatter thus given to the land, the cultivator 

 h^s contributed but five parts f to the land, or its previous 

 manuring, and the atpiosphere has 8tiippli0<i fifteen parts. 

 Jf, then, the cultivator, by still more increasing, his own 

 qontributions, will give ten parts of alimentary matter to 

 the land and crop, there will be added thereto from the atr 

 ij(josphei;e iu the same three-ifuld proportion, or thirty parts> 

 l^nd the whole new productive power will be equal to forty* 

 Ajid if the soil is fitted by it** natural constitution, or the 

 artificial change, induced by calcareous or other applications^ 

 to .fix and retain this double supply of organic mgAter,! the 

 land will not only be: made^ but will r6maia' of as muah 

 |^jq^a^P(d fertility, under the subsequent like course of re^ 

 eeiying; one yeari's protluot for manure for every two other 

 epops, removed. But, on the other hand, if more exhausting 

 /9plture had been allowed, instead of either inci^ased or 

 maintained production, orjf the crops take away more or- 

 ganic, matter than nature's thr^e-fold contributions ;will 

 replace, then a downward progress must begioj and wili 

 proceed, whether slowly or quickly, to extreme poverty , of 

 1^ land, its profitless cultivation, anyd final abandonmentj. 

 Jn this,, the njore usual case, the cultivator's contributions 

 ,0!f ,aliment (obtained from the soil), are reduced from itb* 

 fprmer value, designated as five, first to four, and next ^rtjr 



