EXAMINATION OF TEXTILE FIBRES. 8i 



above. The leathery covering of the cocoanut suppHes 

 a fibre used for matting, etc. Asbestos illustrates the 

 possibility of using a mineral substance for textile pur- 

 poses. Finally, various artificial fibres are made from 

 metals and from cellulose derivatives. 



In the identifiLca,tion of textile fibres the microscope is 

 of prime importance. Animal fibres in general may be 

 distinguished from those of vegetable origin by the 

 fact that both wool and silk are soluble in 5% caustic 

 soda, while the vegetable fibres, made up of cellulose, 

 are not thus affected. Various color reactions are also 

 of value. For the determination of individual fibres, 

 however, the microscope is most satisfactory, since even 

 of the closely related bast-fibres each has its characteris- 

 tic appearance. Furthermore, the quality of different 

 samples of the same kind of fibre is evidenced by the 

 size, twisting, and external structure of the filaments. 

 The effect of chemical reagents and the tensile strength 

 of individual fibres under various conditions is studied 

 with the aid of the microscope in modem textile labora- 

 tories. 



2. The Cotton-fibre. — The cotton-fibre is the vege- 

 table hair borne on the seed of plants of the genus Gos- 

 sypium, serving Hke the down of the thistle for the distri- 

 bution of the seeds by wind. These plants belong to 

 the Mallow family; some are herbaceous and others 

 grow to be bushes twenty feet in height. As the seed- 

 capsule opens a rich white boll bursts out, made up of 

 the cottonseed with the fibres at its free end. 



The cotton-plant grows well between 45° north and 



