io8 



ELEMENTARY CHEMICAL MICROSCOPY 



FIG. 55. Microspectroscope. 



arrangement of the glass prisms, three low and two high, that the 

 deviation of the system will be the difference between the devia- 

 tions produced by the crown and flint prisms. The net result is 

 that for rays of medium wave length (yellow-green) the path of 

 the emerging rays lies substantially in the same line as that of the 



