ANALYSIS OP COTTON AND ITS SOIL. 205 



successful, because used on rational principles, and as a causo 

 to produce an effect, having a direct connection with and de- 

 pendent on it. 



The cotton plant, like every other plant, requires for its 

 perfection certain climate influences, proper cultivation, and a 

 soil of proper physical texture, containing substances which 

 do not and cannot exist in the atmosphere. All plants derive 

 one part of their nourishment from the air, and another part, 

 their mineral constituents, or ash, from the soil. Lime, mag- 

 nesia, potash and soda, with various combinations of chloride, 

 phosphoric and sulphuric acid, are necessary absolutely neces- 

 sary to the growth of the cotton plant. Without these no 

 cotton plant has ever existed, and they cannot be obtained 

 from the atmosphere, (with the exception of chloride and soda 

 under particular circumstances,) and therefore they must 

 either exist in the soil, or be supplied by the application of 

 manure, or this plant will not grow. Manures, therefore, are 

 nothing but substances necessary to the growth of a plant, 

 which are deficient in the soil. If any soil contained all the 

 substances which a plant required, in proper form for its use, 

 there could be no manure for this soil, because there would be 

 no deficiency to supply, and the plant grown on it would reach 

 a degree of perfection limited only by the influence of its cul- 

 tivation, and the climate. If on a soil containing all of these 

 substances no manure would act, then on a soil deficient in 

 any one of them, a manure would act only by supplying that 

 deficiency, and should contain nothing but the substance de- 

 ficient. All others would be useless. 



To manure any soil, then, as ^ matter of course, its de- 

 ficiencies should be ascertained, and the manure made with 

 reference to those deficiencies. These deficiencies can be 

 ascertained in two ways ; the one by a long-continued course 

 of practical experiments,; the other by chemical analysis of 



