Tables 193-194. 

 INDEX OF REFRACTION. 



TABLE 193. — Index of Refraction of Quartz (SIO2). 



187 



Except Rubens' values, — means from various authorities. 

 TABLE 194. — Indices of Refraction for various Alums.* 



* According to the experiments of Soret (Arch. d. Sc. Phys. Nat. Geneve, i8 



t /? stands for the different bases given in the first column. 



For otlier alums see reference on Landolt-Bbrnstein-Roth Tabellen. 



SlWITHSONrAN Tabues. 



I and Comptes Rendus, 1885). 



