REVERSED AND NON-REVERSED SPECTRA. 



103 



TABLE 27. Refraction of glass and of mercury-potassic iodide solutions. New trough. 

 Glass walls, 2 = 0.283 cm. thick, each; solution, = 0.563 cm. thick; K=2B/\*. 

 Figure 68 is an exhibit of the more important of these results. 



* Circles. 



