526 BOTANY or CROP PLANTS 



cotton or some other form of cellulose with nitric acid or 

 sulphuric acid. Military guncotton is a mixture of very 

 highly nitrated cellulose nitrates. Less highly nitrated 

 guncotton is soluble in alcohol and ether, and such soluble 

 guncotton is used in the manufacture of collodion, celluloid, 

 etc. Celluloid is made by subjecting a mixture of guncotton, 

 camphor, and other minor substances to great pressure. 

 Collodion is a solution of guncotton in ether and alcohol. 



Fig. 217. — Cotton-producing regions of the United States. (From 

 Essentials of Geography, Second Book. Copyright, 1916, by Albert Perry 

 Brigham and Charles T. McFarlane. American Book Company, Publishers.) 



Importance, and Production of Cotton.— Cotton' is the 

 most important fiber plant in the world. The clothing of a 

 great majority of people is cotton. The largest of manufac- 

 turing enterprises are concerned with the production of cotton 

 goods. Cotton is the most important article of world trade. 

 The world's crop in 1910 is estimated at 22,433,269 bales, as 

 'compared with 15,893,591 bales in 1900. In 1914, the United 



