Fibres, thin threads of various origin, vegetable, animal, or mineral. Fibrous substances are mainly employed for four classes of purposes - for weaving into fabrics or textiles, as they are termed, for cordage, for paper-making, and for brooms and brushes. Asbestos (q.v.) is the only natural fibrous mineral substance of any economic importance.
Fine metallic wires, though sometimes woven, are not usually considered as fibres commercially.
Fibres of animal origin are few in number but of great economic importance. Silk (q.v.), the cocoon of various species of silkworm, and wool (q.v.), the fleece of the sheep, are the most important; but mohair (q.v.), Cashmere wool, and other forms of goat's-hair and alpaca (q.v.) are also extensively employed as textiles; horse-hair is both woven and used for stuffing; and the hair of the grey squirrel, the badger, the bear, the skunk, and the cow's ears are used for "camel-hair brushes," shaving brushes, and gilder's brushes, as are hog's bristles for harder kinds of brushes. These animal fibres, being all albuminoid, burn with the smell familiar in burning feathers; but wool and hair contain sulphur, which silk does not. They all dissolve if boiled in a ten per cent. solution of soda, which vegetable fibres do not. Vegetable fibres are structurally of three classes, unicellular hairs on seeds, bast-fibres of Dicotyledons and fibro-vascular bundles of Monocotyledons. Cotton (q.v.) is the only member of the first class important as a textile, various so-called silk-cottons and vegetable-silks being used only for stuffing cushions, etc. The members of this class being unaltered and nnthickened cellulose (q.v.) have less strength than the lignified members of the other two classes. Of the second class the most important are flax (q.v.), hemp (q.v.), jute (q.v.), and China-grass, rhea or ramie (Boekmeria) as textiles; sunn-hemp (Crotalaria) for cordage; the baobab (q.v.) for paper; and lime-tree and Cuba bast (q.v.) for mats and gardeners' purposes. Alfa (q.v.) or esparto grass, though a monocotyledon, is used whole, like flax, but is exclusively a paper material, not being, as are many other fibres, employed first as a textile and then worked up into paper from rags. Wood fibre, derived from aspen and other poplars, alder, spruce, and pine, which is now employed in increasingly large quantities as a paper material, though dicotyledonous, can hardly be classed here, since the whole tree, even leaves as well as wood and bark, and not the bast only, is used. Of the third class the chief are the New Zealand flax (q.v.) from the leaves of Phormium tenax; Manila hemp (q.v.) from those of Musa textilis; Sisal hemp and pita, from those of species of Agave (q.v.); pineapple fibre, from those of the pine-apple (Ananas sativus); coir (q.v.), from the fruit of the cocoanut palm; and the "ramenta" at the base of the leaves of the Kitul, Piassaba, and Gomuti palms, which, under the name of "vegetable bristles," are now largely used for brooms, brushes, cables, etc. Brush-grass, or chien-dent, the wiry rhizomes of the South European grass Chrysopoyon Gryllus, and broom-corn or brush, the dried fruit-stalks of the various species of Sorghum (q.v.) grown for their grain in the United States, especially by the Shaker communities, are also important as material for brooms. Besides these, many other fibres are employed locally for these purposes, for stuffing cushions, for cordage, or even for native textile manufactures. Though the inexhaustible wood supply of the world may provide for the paper manufacture, or for all but the very best, constant search is made for new fibres that in length, strength, fineness, elasticity, and colourlessness are suitable for woven fabrics in the first place, and subsequently to make rags valuable for the best paper.