46 



THE MICROSCOPIST. 



Lieberkuhn, or Silver Cup. This is a most useful instru- 

 ment for viewing opaque objects. It is attached to the object- 

 glass in the manner represented by Fig. 16, where a is the 

 lower end of the body of the microscope, b the object-glass, 



Fig. 16. 



to which the Lieberkuhn, c, is attached. The rays of light 

 reflected from the mirror, are brought into a focus upon an 

 object, (7, mounted in the usual way upon glass, or held in 

 the forceps, /. When the object is transparent, or is too small to 

 fill up the entire field of view, the dark well or stop, e, is used. 

 This is generally fixed into the centre of the stage, a little 

 below the upper surface. Sometimes, instead of a Lieberkuhn, 

 a side-reflector is used, and from the greater obliquity of its 

 reflection, is of great advantage in exhibiting delicate struc- 

 tures. 



It has hitherto been considered impracticable to use very 

 high powers with opaque objects, but the Athenaeum informs 

 us that " at one of Lord Rosse's recent scientific soirees, Mr. 

 Brooke showed his new method of viewing opaque objects 

 under the highest powers of the microscope (the |th and yjth 



