142 
ELEMENTARY CHEMICAL MICROSCOPY 
The simplest of these consists of either metal or glass hemi¬ 
spheres of such a size as to fit into the opening of the stage or into 
the opening of a plate laid upon the stage; the upper part of the 
hemisphere is usually a truncated cone. Having a lower hemi¬ 
spherical surface the apparatus may be tipped in any direction 
and at any angle up to approximately 45 degrees. 
The Glass Hemisphere, as employed simply for the purpose 
of facilitating the examination of irregular objects, is shown in 
Fig. 72; a band around the hemisphere gg is rough ground so as 
I 
Fig. 72. Large Glass Hemisphere. An Accessory -which greatly Facilitates the 
Study of Irregular Objects, 
to prevent slipping when the device is tipped. The object 0 laid 
upon the upper or flat surface can be so tipped as to permit the 
different surfaces to be studied without difficulty. 
In certain classes of microscopes as, for example, Dennstedt’s 
“ Universal ” microscope,^ the stage itself consists of a huge 
hemisphere, thus permitting the orientation of irregular objects 
in all directions. This microscope was designed to meet the 
requirements of forensic investigations where large objects of 
irregular outline are the rule. 
The application of the hemisphere is also found in several 
‘ Dennstedt, Die Chemie in der Rechtspflege, p. 285, Leipzig, 1910. 
