SOME USEFUL PLANTS AND PLANT PRODUCTS 315 



greater part of the starch thus prepared is from potatoes and 

 com ; but it is also obtained from other cereals (especially 

 rice), from beans, and from the arrowroot plant. Tapioca 

 is the starch extracted from the roots of the cassava, and sago 

 is the starch obtained from the pith of certain palms. Dex- 

 trin, a gum-like substance, is made by treating starch with 

 hot dilute acids. It is used for giving a smooth finish to 

 paper, for stiffening cotton cloth, in making mucilage, and 

 for other purposes. 



334. Sugar-producing Plants. — By far the greater part 

 of the sugar in the market is obtained from the stalk of the 



Fig. 173. — Harvesting sugar cane in Louisiana. 



sugar cane and from the root of the beet. The sugar from 

 both sources is alike, and in either case it is called cane sugar. 

 The juice of the beet or sugar cane is pressed out and evapo- 

 rated ; the sugar which then appears in the form of crystals 

 is separated from the remaining liquid (the molasses), and 

 after being refined and recrystallized is sold in the form of 

 granulated sugar, pulverized sugar, or loaf sugar. Sugar is 

 also made on a comparatively small scale from the juice of 

 some palm trees, from that of the sorghum (although this is 



