192 THE CANADIAN NATURALIST. [June, 



For it is to be remeinbered that a soil may, by the excessive use of 

 lime, common salt, nitrates, and other solvent or disintejirant 

 manures, as also by diligent ploui;hing, scarifying, crushing, and 

 other processes of mechanical comminution, be made to yield its 

 reserves in accessible form, at an unduly accelerated rate. The 

 same result may ensue, if the volatile forms of plant-food, "uhich 

 nature supplies only in moderate annual proportion, be addc-d m 

 pr fusion to the soil, without due c ire to conjoin therewith pro- 

 portionate supplies of ash-constituents, or cinereal food. 



KuTATioN OF Crops often Exhaustive — Even the vaunt- 

 ed system of rotation — i. e., the growth of fodder-crops alternate- 

 ly with cereals, these latter receiving as manure the dung of the 

 cattle fed on the former — is but too oiten so carried on as to be 

 in truth a spoliatory operation ; a sort of artifice, serving only to 

 disguise and retard the period of jSnal exhaustion ; which so far 

 from averting, it does but make more profound. For tlie power- 

 ful, deeply-penetrating roots of the fodder-crops extract from ti.e 

 subsoil its ash-constituents; which, after passing through the 

 bodies of the cattle, are deposited in their dung on the surface, 

 thence to sink into the upper layers of the soil, and so to find their 

 way to the fibres of the young, slender-rooted cereal plants ; in 

 Wfiose grain they are finally exported fioni the farm. 



Lois-VVeedon System ; its Spoliatory Character. — 

 The so-called i.ois-Weedon system of cultivation is open to simi- 

 lar objection. This system, as is well known, consists in the grow- 

 ing, year after year, upon soil which is never manured, of corn- 

 planis thinly sown in rows, separated by wide intervals ; the in- 

 t^ rvafs being each year stirred and tallowed, to become the next 

 year's growing spaces; and so on in annual alternation This sys- 

 4iem of husbandry, which may be regarded as an extreme exem- 

 piihcation of Jettiro Tuil's doctrine, is stated to have elicited froin 

 the nelds in which it is pursued, a series of full grain -crops lor 

 many years in succession. This result is in the highe.-t degree 

 probable. And this apparent prosperity may be kept up tor a 

 eeries of years, longer or shorter for each soil, as this may happei 

 to have been originally more or less richly endowed by nature with 

 cinereal plant-food. But the end of this method alsoisexuaustion, 

 —inevitable foredoomed exhaustion, — exhaustion o. wnicu each 

 *' prosperous " crop is but an advancing stage, and whose rate the 

 .ciieuiist measures, with stern precision, in the auuuaily lessening 



