TABLES 193-194. 

 INDEX OF REFRACTION. 



TABLE 193. Index of Refraction of Quartz (810 2 ). 



i8 7 



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. Genfeve, 1884, 1888, and Comptes Rendus, 1885). 



t R stands for the different bases given in the first column. 



For other alums see reference on Laudolt-Bornstem-Roth Tabellen. 



SMITHSONIAN TABLFS. 



