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CHAPTER XII. 



THE STRUCTURE AND USES OF WOOL. 



Wool is almost identical in its structure with hair, the 

 only difference being that wool is curly and very fine, in 

 contrast to hair, which is straight and coarse. 



The peculiarity of the structure of wool, that causes it to 

 " felt/' is, first, its extreme curliriess, and secondly, its scales. 

 Hair grows from the true skin, passing through the outer or 

 false skin. The one is called the derma, the other is called 

 the epidermis. The hair follicle or germ is situated in the 

 former, and is propagated by germs, which being formed by 

 the follicle, the preceding ones are pushed out as the new 

 ones are formed. These germs are in the shape of scales. 

 If it were possible to make a stack of very minute fish 

 scales, one upon another, with the center of each one capped 

 and the fifth outer circle turned up, this tall stack would 

 represent a hair. Looking at a hair from one side with a 

 powerful microscope, it looks like a saw, or if the entire hair 

 is seen it looks like a long cylinder covered with shingles. 

 Take two hairs and place them together, with the ends re- 

 versed, and these scale points will hang. Rub a hair be- 

 tween the fingers and it will travel towards the upper end. 

 This is ^caused by the points of these scales hanging to the 

 fingers, and thus it is pushed along. It is this quality that 

 makes wool felt; but it would still not felt well unless it 

 was curved. Therefore wool, which as before remarked is 

 curved hair, has minute waves in it. These are caused by 

 a regular thickening of the cortical part of the fibre, and 

 this thickening occurs alternately on one side or the other. 

 The value of the wool depends upon this curly character, as 

 the felting property is produced by it. There is great dif- 

 ference in the fineness of wool. The common coarse wools 



