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CHAPTER II.

TEXTILE FIBRES AND TISSUES MADE THEREFROM. THICKENINGS ANDPLASTIC MORDANTS.

"D EFORE proceeding with an examination of those substances which serveto impart colour to woven tissues, we will devote a portion of our spaceto the study of textile fibres. Any substance capable of yielding a certaincontinuous and uninterrupted length of filamentary matter may be calledtextile fibre, and the number of such substances is large, but the proportionsuitable for application to weaving purposes is limited, and only a few canbe employed alone in the fabrication of tissue. Fibres are divided accordingto their origin into three groups—I. Mineral; 2. Vegetable; and 3. Animal.Up to the present time the artificial production of fibres has not succeeded,and those most useful to man are products of the vital activity of plants andanimals.

Mineral Fibres.

The only mineral fibre we are acquainted with is asbestos or amianth, andalthough it cannot be dyed it may be interesting to refer briefly to it here.It is a polysilicate composed chiefly of lime, magnesia, and small quantitiesof alumina and iron. It is related to pyroxen ; the percentage composition ofthe Tarantaise variety is expressed as follows :—Silica, 58'2o; alumina, o - i4;protoxide of iron, 3-08; protoxide of manganese, o - 2i; magnesia, 22 - io;Lime, IS'55 ; water, 0-14. This variety is met with in very long, well-defined,glossy, and silky-looking filaments in that portion of the ancient Duchy ofSavoy called La Tarantaise ; the same variety also occurs in Corsica, where itwas used by the celebrated philosopher Dolomieu for packing the mineralscollected by him during his sojourn in that country.

Asbestos can be woven into tissues, especially if a flax fibre is worked up withit; its use is, however, very limited in the present day. The ancients whowere in the habit of burning their dead used a tissue made of asbestos inorder to collect the ashes of the dead bodies without admixture of the ash of thecombustible used during the process of burning. The name “ amianth,” whichsignifies “undefiled”—that is, pure and unchangeable in the fire—has beengiven to it in consequence of its being incombustible. Tissues made ofasbestos are at present practically used in Russia only. The fire brigade ofSt. Petersburg are provided with gloves and other portions of wearing apparelmade of this substance in Siberia ; it has also been used in the manufactureof paper in France and America.