in anatomy, natural history, &c. a term used in the same sense with fibre, for those fine threads whereof the flesh, nerves, skin, plants, roots, &c. are composed. See Fibre.

Vegetable Filaments form a substance of great use in the arts and manufactures; furnishing thread, cloth, cordage, &c.

For these purposes the filamentous parts of the Can- nabis and Linum, or hemp and flax, are employed a- mong us*. But different vegetables have been em- ployed in different countries for the same uses. Putre- faction destroys the pulpy or fleathy matter, and leaves the tough filaments entire: By curiously putrefying the leaf of a plant in water, we obtain the fine flexible fibres, which constituted the basis of the ribs and mi- nute veins, and which now form as it were a skeleton of the leaf. Alkaline lixivia, in some degree, produce similar effects to putrefaction.

The Sieur de Flacourt, in his history of Madagascar, relates, that different kinds of cloth are prepared

*See Hemp and Flax; also Cotton. Filaments. in that island from the filaments of the bark of certain trees boiled in strong lye; that some of these cloths are very fine, and approach to the softness of silk, but in durability come short of cotton; that others are coarser and stronger, and last thrice as long as cotton; and that of these the sails and cordage of his vessel were made. See also the article Bark.

The same author informs us, that the stalks of nettles are used for the like purposes in his own country, France. And Sir Hans Sloane relates, in one of his letters to Mr Ray, that he has been informed by several, that mullin and callico, and most of the Indian linens, are made of nettles.

In some of the Swedish provinces, a strong kind of cloth is said to be prepared from hop-stalks: and in the transactions of the Swedish academy for the year 1750, there is an account of an experiment made in consequence of that report. Of the stalks, gathered in autumn, about as many were taken, as equalled in bulk a quantity of flax that would have produced a pound after preparation. The stalks were put into water, and kept covered therewith during the winter. In March they were taken out, dried in a stove, and dressed as flax. The prepared filaments weighed nearly a pound, and proved fine, soft, and white: They were spun and woven into six ells of fine strong cloth. The author, Mr Shifler, observes, that hop-stalks take much longer time to rot than flax; and that, if not fully rotted, the woody part will not separate, and the cloth will neither prove white nor fine.

Hemp, flax, and all other vegetable filaments, and thread or cloth prepared from them, differ remarkably from wool, hair, silk, and other animal productions, not only in the principles into which they are resoluble by fire, but likewise in some of their more interesting properties, particularly in their disposition to imbibe colouring matters; fumery liquors, which give a beautiful and durable dye to those of the animal, giving no stain at all to those of the vegetable kingdom.

A solution of copper in aquafortis, which had been changed blue by an addition of volatile spirit, on being mixed with a little solution of tin, became turbid and greenish. Pieces of white silk and flannel boiled, without any previous preparation, in this mixture, received a bright deep yellow dye; whilst pieces of linen, prepared and unprepared, came out as colourless as they were put in.

Fishing-nets are usually boiled with oak-bark or other like astringents, which render them more lasting. Those made of flax receive from this decoction a brownish colour, which, by the repeated alternations of water and air, is in a little time discharged, whilst the fine glossy brown, communicated by the same means to flaxen nets, permanently refills both the air and water, and stands as long as the animal filaments themselves. In like manner the stain of ink, or the black dye from solutions of iron, mixed with vegetable astringents, proves durable in silk and woollen; but from linen, the astringent matter is extracted by washing, and only the yellow iron-mould remains.

The red decoction of cochineal, which, heightened with a little solution of tin, gives the fiery scarlet dye to wool or silk that have been previously impregnated with solution of tartar, makes no impression upon linen or cotton prepared in the same manner. Mr du Fay informs us in the Memoirs of the French Academy for the year 1737, that having prepared a mixed cloth whose warp was of wool and the woof of cotton, and thoroughly blended the two together by fulling, he still found the cotton to reflect the action of the scarlet liquor, and the wool to receive the same colour from it as wool by itself, the stuff coming out all over marbled fiery and white.

Many other instances of this kind are known too well to the calico-printer; whose grand desideratum it is, to find means of making linen receive the same colours that wool does. The physical cause of the difference is wholly unknown; and indeed, of the theory of dyes in general, we know as yet extremely little. (See Dyeing.) Are animal filaments tubular, and the colouring atoms received within them? Are vegetable filaments solid, and the colour deposited on the surface? Or does not their different susceptibility of colour depend rather on the different intrinsic properties of the two? There are many instances of a like diversity, even in the metallic kingdom, where a mechanical difference in texture can scarcely be presumed to be the cause: Thus silver receives a deep stain from sulphurous or putrid vapours, or the yolk of a boiled egg, which have no effect upon tin.

Filaments, among botanists. See Botany, p. 434, col. I.