Cottonwood is used to a small extent and yields a pulp by the soda process of the same general nature as poplar.
Esparto (Stipa tenacissima and Lygeuin Spartum). Granzinem.
This plant grows wild in Spain and northern Africa. It is gathered, baled and shipped, chiefly to England, where large quantities are used. The fibers of the fibrovascular bundles constitute the paper-making material. The fiber is tough and is particularly suitable for the manufacture of book papers, yielding a soft paper of good quality. The fibers are 1.5 to 2 mm. long and .0125 to .022 mm. in diameter. The yield of paper is about 45 per cent. It has been used for centuries in southern Spain and northern Africa for the manufacture of baskets, matting and similar wares. The leaf, which grows three to five feet long, is used and is stripped annually from the plant by hand. This can be done only in dry weather. The plant must grow ten to fifteen years before the leaf is suitable for paper-making. Its cultivation has not been suc cessful. [See Fiber plants.] Flax (Linum usitatissimum). Linaecce. Figs. 405 407.
The bast fiber from the inner bark of the straw is employed in the form of scutching refuse, spin ning waste, threads, and new and old rags. The fibers have a length of 25 to 30 mm. and an aver age diameter of .02 mm. The yield of paper from rags is about 75 per cent. Flax fiber is the most suitable material for the preparation of high-class papers, such as are used for court and other rec ords, which are to be handled a great deal and preserved for many years. [See Flax.] Ground wood.
In addition to the use of wood pulp prepared by chemical treatment, paper is also made from wood pulp prepared by grinding against a stone under a stream of water, such pulp being known as " ground wood" or " mechanical wood." The paper thus prepared has only a temporary value, as the fibers are very short, much shorter than from the same wood chemically treated ; and, as the color ing matter and ligneous matter are still in the pulp, the paper darkens and deteriorates rapidly. Spruce is most largely used for grinding. Small quantities of hemlock, pine, balsam and poplar are also used. Ground wood is used chiefly in making
newspaper, which consists of about 80 per cent ground wood and 20 per cent sulfite. It is also used alone or in mixture with other materials in making board, cards and cheap wrapping paper.
Hemlock (Tsuga Canadensis). Coniferce. Fig. 454.
This wood yields a somewhat coarser pulp of the same general character as spruce, but is reduced with more difficulty. Hemlock is native from the St. Lawrence river to Wisconsin on the west, south to Delaware and Maryland, and in the moun tains to Alabama. It is now employed largely in Wisconsin, Michigan, Pennsylvania, New York, Ohio and West Virginia for making sulfite pulp, which is used for the same class of paper as spruce is. The fibers have a length of 1 to 4 mm. and a diameter of .021 to .063 mm.
Hemp (Cannabis sativa). Urticacece. Figs. 566-568.
The bast fiber from the inner bark of the hemp plant is used in the form of scutching refuse, spin ning waste, threads, cuttings, rope ends and canvas. As the fiber has great strength, it is used largely in combination with rags for bank note and ledger paper. Unbleached, it is used for wrapping paper and for cable insulation. Hemp is cultivated in Russia, Italy, France, China, Japan, and in the United States. The fibers are about 22 mm. long and .022 mm. in diameter. The yield of paper is about 68 per cent. [See Hemp.] Jute (Corchorus capsularis and Corchorus olitorius). Tiliaccm. Figs. 392, 393.
The fiber of jute is thin-walled, highly lignified, and contains much coloring matter. It is obtained from the inner bark and is used in the form of threads, butts, bagging and spinning waste. It is used chiefly where strength is of more importance than appearance, as in wrapping papers and heavy envelopes ; it is seldom used in white papers. Jute is cultivated commercially in India, Burmah, Japan, China and Formosa and has been introduced into the United States. The fibers are 2 mm. long and .022 mm. in diameter. The yield of paper is 50 per cent. [See Fiber plants.] Manila hemp (Hasa textilis). Musacem. Fig. 398.