52 THE SHEEP AND WOOL INDUSTRY 



quality and of various lengths. This Extract wool is generally 

 used in low-priced or shoddy goods, though in a few cases 

 it is made into a good article. One of the most peculiar 

 things about caustic alkalies is that if you make a very strong 

 or concentrated solution from 80 to 100 Twaddle, the tem- 

 perature at 20 C., it will not dissolve wool at all, but 

 considerably strengthens the fibre and bleaches it. Wools 

 are mercerized in this manner that is, making them resemble 

 silky goods, and increasing the lustre of the fibres. The 

 concentrated caustic alkali solution has the power of closing 

 up all the scales, thus making the surface of the fibre smooth 

 like hair. This closing up of the scales would give the wool 

 the increased lustre, and also account for its greater tensile 

 strength. 



