3 6a 



Tables 401 and 402 

 INDEX OF REFRACTION 



TABLE 401.— Index of Refraction of Quartz (Si0 2 ), 18°C 



Except Rubens' values, — means from various authorities 



* According to the experiments of Soret (Arch. d. Sc. Phys. Nat. Geneve, 18S4, 1888, and Comptes Rendus, 1885). 



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



For other alums »ee reference on Laiidolt-h56rustem-Roth Tabellen. 



Smithsonian Tables 



