126 



MICRO-SPECTROSCOPE AND POLAR/SCOPE. [CH. VI. 



Fig. 117. 



Fig. 118. 



Fig. 119. 



Fig. 117 (1). Section of the tube and stage of the microscope with the spectral 

 ocular or micro spectroscope in position. 



Amici Prism (g 167). — The direct vision prism of Amici in which the central 

 shaded prism of flint glass gives the dispersion or separation into colors, while the 

 end prisms of crown glass cause the rays to emerge approximately parallel with 

 the axis of the microscope. A single ray is represented as entering the prism and 

 this is divided into three groups {Red, Yellow, Blue), which emerge from the 



