670 PHARMACEUTICAL BOTANY 
require brighter light than the lower; the oil immersion full 
opening. 
5. Place the slide on the stage in a horizontal position with 
the object over the middle of the opening through which light is 
thrown from the mirror. 
Fic, 499.—Binocular microscope. This is a compound microscope with a bin- 
ocular body designed to relieve eyestrain for those doing microscopical research 
work or otherwise engaged for prolonged periods with the microscope. Note the 
parallel position of the eyepiece tubes which are adjustable for interpupillary 
distance by means of a compound slide, with the distance indicated on a numbered 
millimeter scale for future guidance. One tube has a spiral adjustment for correct- 
ing any difference in vision existing between the two eyes. The instrument shown 
is that designated CAE of the Bausch and Lomb Optical Co. 
6. With the lower power in position quite close to the 
object, move the coarse adjustment upward until either the 
object or small solid particles on the slide appear distinctly, 
