CHAPTER XV 



COTTON — COMPOSITION AND PRINCIPAL USES 



Of course, the great usefulness of cotton lies in the lint 

 or fiber. In fact, when one speaks of " cotton," he usually 

 refers to the fiber rather than to the plant as a whole. 

 There are other uses, however, that must be considered ; 

 and it is important to know the chemical composition of 

 the parts. 



241. The lint. — Cotton lint consists mostlj^ of woody 

 fiber (cellulose), which is formed chiefly from the carbon 

 dioxid of the air. A bale of cotton (500 pounds of lint) 

 contains only 1.7 pounds of nitrogen, half a pound of phos- 

 phoric acid, and 2. .3 pounds of potash. If these sub- 

 stances be rated at their prices in commercial fertilizers, 

 the plant -food removed in a bale of cotton would be worth 

 only about 42 cents. 



In selling only the lint the farmer removes from the soil 

 a smaller amount of fertility than in growing any other 

 American crop. When cotton lands decline in fertihty, 

 it is not because of the lint removed, but chiefly on account 

 of the failure to rotate crops and thus to replenish the 

 supply of vegetable matter. 



242. The seed. — The seed of cotton, unhke the lint, 

 is rich in nitrogen, phosphoric acid, and pota.sh. Hence 

 the sale of cotton seed removes large quantities of these 

 forms of plant-food. 



267 



