236 INDUSTRIAL APPLICATIONS OF PHASE MICROSCOPY 



Fig. VI. 7. Rayon fibers in cross section. A, brightfield. B, dark-contrast (A — ) 



phase. C, D, bright-contrast pha.se, 1000 X : E, F, fibers containing oil droplets for 



delusterification, llOOX. E, brightfield. F, bright-contrast phase. 



