Jail., 1941 PREPARATION OF PHENYLARSENOXIDES 9 9 for microscopical examination (Fig. 1). Refractive indices (determined by the immersion method in organic oily liquids): n,= 1.674; ng= 1.733; ny=> 1.733; all t0. 002. n, and ng were most often obtained, In parallel polarized light (crossed nicols), the birefringence was strong. Many fragments did not extinguish sharply with crossed nicols.
