INTRODUCTORY. 3 



such as the various species of Agave or Aloe, Phormium tenax or JS r ew 

 Zealand Hemp, Agave heteracantha, the Mexican fibre largely used 

 for brush -making, and the Musa text His or Manila hemp, a cordage 

 fibre plant. 



III. Fruit Fibres. These are mostly obtained from the large, thick, 

 and leathery covering or pericarp of the cocoanut. The bast and coir 

 fibres of commerce, so much used for matting and for brush making 

 of the coarser kinds, are obtained from the pericarp covering. The 

 well-known Loopha of the shops is also a fruit ; it belongs to the 

 cucumber family, and its use as a kind of flesh brush is well known, but 

 latterly it has also been used in the textile industries. 



IV. Mineral Fibres are chiefly represented by Asbestos. 



VEGETABLE FIBRES. 



Physical and Chemical Properties. The principal vegetable fibres 

 are plumose and 'bast.' Both are used for spinning and for weaving, 

 and their prices fluctuate in accordance with the quality and quantity of 

 the annual crops. The plumose fibres are composed of cellulose. Each 

 fibre is a unicellular hair or trichome. Cellulose is one of the three 

 principal constituents of the vegetable cell. It forms the outer mem- 

 brane of the cell wall. It is a somewhat inert carbohydrate, the chemical 

 composition of which is expressed by the formula CgHjQOg. The cotton 

 hairs are nearly pure cellulose ; they originate in, and are attached to, 

 the testa of the seed, the so-called fibre being a local elongated out- 

 growth of the cell wall. The young fibre is hardly a tube, but becomes 

 tubular when ripe, in which are found the protoplasm and cell sap. 

 The apex is solid. During growth the cell wall increases in thickness 

 by the deposition of new cellulose material from the protoplasm ; the 

 latter is the vital element, and when it is withdrawn an important change 

 takes place, the free end of the fibre twists up and assumes a spiral 

 or convolute structure when fully ripe. The essential quality of most 

 cottons is strength, which depends on the amount of spirality in the 

 fibres and serves as a clue to the value and the classification of raw 

 cottons generally. When cotton fibres are treated with Schweitzer's 

 solution (an aminoniacal solution of oxide of copper), some important 

 structural characters may be discerned. The late Mr. John Butter worth, 

 F.R.M.S., of Shaw, Manchester, made some researches on cotton fibres 

 magnified 1600 diameters and treated with the reagent. Mr. Butterworth 

 noticed spiral threads apparently crossing and tightly bound round the 

 fibre at irregular distances, also spiral threads passing from one stricture 



