Fig. 10.
Pleochroism of cellulose observed in a polarizing light microscope without an analyser after treatment with chloroiodide of zinc. (A) A cable anchored in a diaphragm illuminated with linearly polarized light with an azimuth of polarization perpendicular to the long axis of the cable. (B) The same cable illuminated with linearly polarized light parallel to the long axis of the cable.