Review of Essays on Calcareous Manures. 141 



which they require of this principle, for their frame work, and for 

 their intimate constitution. It would then be a better definition than 

 that above, to say that to improve the soil, is to give to it the princi- 

 ples which it requires, and does not contain." — Puvis, 



* * * * * * ^ ^ ■» * 



" In the neighborhood of great cities, alimentary manures being 

 furnished on good terms, may well vivify the soil, but animal ma- 

 nures cannot suffice but in a few situations and of small extent, and in 

 every country where tillage is highly prosperous, improving manures 

 are in use. The department of the North (France,) Belgium, and 

 England owe to them in a great measure their prosperity. The de- 

 partment of the north (which is, of all Europe, the country where 

 agriculture is best practised and the most productive,) spends every 

 year upon two thirds of its soil a million of francs in lime, marl, ashes 

 of peat and bituminous coal, and it is principally to these agents, and 

 not to the quality of the soil, that the superiority of its production is 

 owing. The best of its soil makes part of the same basin, is of the 

 same formation and same quality as a great part of Artois and Picardy, 

 of which the products are scarcely equal to half the rate of the North. 

 Neither is it the quantity of meadow land which causes its superior- 

 ity ; that makes the fifth part of its extent, and Lille, the best Arron- 

 dissement, has scarcely a twentieth of its surface in meadow, Avesne 

 the worst of all, has one third. Nor can any great additional value 

 be attributed to the artificial meadows, since they are not met with ex- 

 cept in the twenty sixth part of the whole space. Neither can this 

 honor be due to the suppression of naked fallows, since in this coun- 

 try of pattern husbandry, they yet take up one sixth of the ploughed 

 land, every year. Finally the Flemings have but one head of large 

 cattle to every two hectares, a proportion exceeded in a great part 

 of France. Their great products are due to their excellent economy 

 in the use of manures, to the assiduous labour of the farmers, to cour- 

 ses of crops well arranged, but above all, we think, to the improvers 

 of the soil, which they join to their alimentary manures. Two thirds 

 of their land receive these regularly : and it is to the reciprocal action 

 of these agents of melioration that appears to be due the uninterrupted 

 succession of fecundity, which astonishes all those who are not accus- 

 tomed continually to see the products of this region." — Puvis. 



The agriculture of adjacent parts of Belgium is even more instruc- 

 tive as an example. Those parts of that rich country which are 

 now most remarkable for fertility, as for instance the Pays de Waes, 



