THE BUST AMONG THE COTTON. 151 



ceed, it must consume them in sufficient quantities. The at- 

 mosphere contains none of those contents, consequently the 

 whole amount of them must come from the soil in which the 

 plant roots. If, now, the cotton plant be cultivated for a 

 number of years in succession on a body of land, that land 

 must be entirely deprived of those ingredients, at least of that 

 part which is in solution. As soon as the quantity begins to 

 become insufficient, even only of one of those ingredients, the 

 cotton plant will no longer grow vigorously ; a stagnation of 

 its growth must take place until the insufficiency has been 

 supplied ; such a stagnation produces diseases of all kinds, and 

 among them the rust. 



A sovereign remedy against the rust is, therefore/ the intro- 

 duction of a system of agriculture in conformity with Nature, 

 and with the science which has been abstracted from a long 

 practice, and the investigation of the nature of plants and soils 

 by chemical analysis. 



If we observe Nature closely, we will find that if certain 

 vegetables, which have grown for a long time upon the same 

 soil, are removed from that soil, the same kind will not be re- 

 produced spontaneously, but quite different genera and species 

 will appear ; the simple reason is, because the soil has been 

 exhausted of such ingredients as that kind of vegetables require 

 for its growth ; but there are still other ingredients in it which 

 are suitable for other plants, of a different genus and species, 

 and such will appear spontaneously upon the soil, and grow 

 luxuriantly. Nature points, therefore, to a rotation of crops 

 in agriculture ; and if we obey Nature and observe such a ro- 

 tation if we supply, from time to time, those ingredients which 

 are most necessary for the growth of our crops, our lands will 

 never be exhausted ; on the contrary, they will improve, and 

 the vegetables which we cultivate will grow luxuriantly, with- 

 out a stagnation in their growth, they will remain free from 



