280 INDUvSTRIAL PLANTS 



aration requires more labor, it is more costly and hence 

 more a fiber of luxury. The flax plant (Fig. 217) flourishes 

 throughout the temperate zones, and was cultivated in the 

 Old World even during prehistoric times. To-day the world's 

 supply of flax comes chiefly from northern Europe. 



The bast of a flax plant forms the main strengthening 

 element of its stem, running near the surface where, plainly, 

 the strain is greatest. These fibers consist of nearly solid 

 cylinders of almost pure cellulose. The essentials of the 

 process by which pure flax is obtained are, first rotting or 

 "retting" the stems and then, after drying them, breaking 

 the weakened parts into fragments, and finally beating and 

 combing these away from the bast. After further combing 

 to separate the longest and best fibers, and then bleaching, 

 they are ready to be manufactured into the finest linen fab- 

 rics as well as such strong materials as canvas and duck, and 

 the foundation of carpets and oil-cloth. The strongest thread 

 and twine, and the finest lace are also made from flax, while 

 from linen rags are made the best papers for writing and 

 artist's use. From this paper, by treatment with sulphuric 

 acid, a "vegetable parchment" is made which full}' takes the 

 place of the parchment formerly manufactured from the 

 skin of sheep. 



Jute is obtained from two closely related species (Fig. 218). 

 Though cultivated from very early times in India the fiber 

 has assumed commercial importance only within the nine- 

 teenth century. The bast is extracted from the stem in some- 

 what the same way as flax. In luster and fineness it rivals 

 flax, but as it contains less cellulose it is inferior in strength 

 and enduring qualities. Its most important use is for coffee- 

 sacks, cotton-bagging, burlap, webbing, and similar coarse 

 fabrics. It is coming rapidly into use, however, for finer 

 fabrics, imitating linen and silk, and as a substitute or adul- 

 terant of hemp it is used extensively in cordage; l^ut it is 

 ill-suited for this purpose on account of its rapid deteriora- 

 tion. 



Hemp (Fig. 171) is coarser than flax but longer and stronger. 

 It is thus especially well adapted for twine, rope, and heavy 

 cordage, and likewise for sail-cloth, bagging, and similar 



