14 BOARD OF AGRICULTURE. 



lence, — that which exercises most influence in the mixture, is the 

 nitrogenous matter. For leguminous plants, the agent Avhose suppres- 

 sion causes most damage is potassa, which plays the principal part in 

 the mixture. For turnips and other roots the dominant element is 

 phosphate of lime. 



" By employing these four well-known agents, M. Ville's system may 

 well replace the old system of cultivation. With him, the rule that 

 manure must be produced upon its own domain is not absolute. Dur- 

 ing four succeeding years, M. Ville has cultivated, at the Vincennes 

 farm, wheat upon wheat, pease upon pease, and beet-root upon beet-root ; 

 and he entertains no doubt that he could continue to do so for an indefi- 

 nite period, the only condition necessary to be fulfilled being — to 

 return to the soil, in sufficient proportion, the four fundamental elements 

 above named. 



" Suppose we wished to cultivate wheat indefinitely. We should at 

 first have recourse to the complete manure, and afterwards administer 

 only the dominant element, or nitrogenous matter, until a decrease in 

 the successive crops showed that this culture had absorbed all the 

 phosphate of lime and potassa. As soon as a diminution in the crops 

 manifests itself, we must return to tbe complete manure, and proceed as 

 before. 



" Suppose that, instead of an exclusive culture, it be desired to intro- 

 duce an alternate culture in a given field. We commence with the 

 agent that has most influence on the plant with which we start. If 

 that be a leguminous plant, we at first administer only potassa. For 

 wheat, we should add nitrogenous matters. If we conclude with tur- 

 nips, Ave have recourse to phosphate of lime ; but when we return to 

 the point from which we started, all four elements must be employed. 



" As may be seen, this system differs radically from that hitherto 

 adopted. It has not for its basis 'a complex manure administered to the 

 soil by wholesale, in which we endeavor to turn all its constituents to 

 account by a succession of different crops. In M. Ville's system, he 

 supplie-! to the soil only the four governing agents of production, Avhich 

 are added gradually, one after another, and in such manner as to supply 

 each kind of crop with the agent that assures the maximum yield." 



The translator does not speak of, nor does the text relate to, 

 the other essentials of farming in regard to drainage, quality of 

 soil, and the necessity of fermenting manures, as a sort of yeast, 

 to induce in the earth that fermentation which quickens vege- 

 tation so much. It will not supplant other manures ; it comes 

 in aid of them, and supplies the want of them, when they are 

 not present. All farmers are well aware that certain soils 



