440 SUMMARY OF CUERENT RESEARCHES RELATING TO 



Reiehert's Polarization Microscope. — This (fig. 55) is an inex- 

 pensive form of stand by C. Eeicliert, the chief peculiarity of which 

 is that the wheel of diaphragms with five apertures rotates at the end 

 of a horizontal arm, which, as with the condenser in the preceding 

 form, swings on a pivot away from the stage, as shown in the figure. 

 The diaphragm-plate is raised above the arm on a vertical axis, so 

 that the tube attached to the largest aperture to hold the polarizer 



Fig. 55. 



may not prevent the complete i t tion of the plate.* A notched pro- 

 jection on the arm falls against a second spindle beneath the stage 

 when the apertures of the diaphragm-plate are central. The tube 

 which holds the polarizer has a rotating fitting, and carries the 

 polarizer with it. 



The analyser fits over the eye-piece without any attachment, which 

 would seem to be undesirable, even though the Microscope can only 

 be used in an upright position. 



* When the polarizer is in place the plate cannot rotate completely, but no 

 rotation is then required. 



