OF DENISON UNIVERSITY. 
127 
represents the polarizing microscope prepared by Bausch and Lomb, 
Rochester, N. Y. , while figure i. of plate XI gives a diagram of the 
optical parts, etc., of the Fuess-Rosenbusch stand in use in Germany. 
The rotating stage is centered and graduated to record the angular 
position of the slide. The polarizer (rr) is placed below the stage 
and consists of a Nicols’ prism set in a. rotating cylinder. Above it is 
