MICROSCOPE IN MANUFACTURES 



uncomfortable fabric ; firmness and durability. 

 Animal fibres used in the manufacture are either 

 hairs or silk. 



The most important vegetable fibre is cotton, it 

 consists of the hairs from the seed coats of several 

 species of Gossypium, a plant closely related to our 

 common mallow. There are very many different 

 kinds of cotton and the qualities of the fibres of 

 these different cottons vary tremendously Each 

 hair is one cell and more or less spindle shaped, 

 that is to say, thicker towards the middle than at 

 the base. If we can obtain a little raw cotton we 

 should certainly examine it under the microscope; 

 this may best be done by laying one or two fibres 

 in a drop of water on a slide. Under the low 

 power, the first thing that will attract our atten- 

 tion is the fact that the fibres are twisted, cork- 

 screw fashion, though not regularly nor throughout 

 their whole length. This curious twisting makes 

 raw cotton easily recognised and it is, at the same 

 time, a very valuable peculiarity of these plant 

 hairs. The greater the number of twists and the 

 greater their regularity, the more valuable the cotton 

 becomes for weaving purposes. Under a higher 

 magnification, we recognise other characteristics of 

 the cotton fibre. Each fibre is somewhat flattened, 

 its edges are thick and, running up the centre, there 

 is a fairly broad lumen, as it is called. Cover- 

 ing the whole there is a skin which by the 

 way is often wanting in the fibres of cotton 

 fabric owing to the chemicals with which the 



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