EXAMINATION OF TEXTILE FIBRES. 83 
solution of hydrate of copper in ammonia, the cellulose 
dissolves and swells up the cuticula into bubbles between 
the twists of the fibre, while at the twists the cuticula con- 
tracts, giving the characteristic beaded appearance shown 
in Fig. 31, e. 
Much of the cotton in textile goods has been subjected 
Fic. 32.—Tur Corron-ribre. (After Hassack.) 200 diameters. * 
to the process of mercerization, or immersion of the cloth 
in a stretched condition in strong caustic soda solution. 
Cloth thus treated is stronger, takes dyes better, and has a 
closer, firmer texture and a fine glossy appearance. Under 
the microscope the individual fibres appear as crinkly, 
irregular cylinders instead of flat ribbons and the central 
~ canal is much shrunken. Sometimes the fibres are so 
