ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
381 
In the polarizing apparatus of large field of view, both nicols can be 
easily rotated, while the under one is attached to a side arm, so that the 
conversion from polarized to ordinary light can be rapidly effected. 
The instrument is also provided with centering apparatus for the 
objective, Bertrand’s condenser, and mirror, plane and concave, which is 
adjustable in height and on both sides. 
Reichert Hand-Microscope. — This model, represented in half its 
natural size in fig. 40, is intended for lecture and school work, &c. The 
focal adjustment is effected by sliding in a socket. The stage^projects 
Fig 40. 
to one side, where it is provided with a frame under which there can be 
clamped a piece of paper, on which the structures observed in the 
Microscope can be drawn. 
C3) Illuminating and other Apparatus. 
Reichert’s Illuminating Apparatus. — This apparatus, represented 
in figs. 41 and 42 as arranged for all modifications of direct and oblique 
light, consists of: — (1) A condensing system of great intensity with 
aperture of 1*20 or 1 -40 ; (2) a diaphragm-holder with iris-diaphragm, 
