CONTENTS XV11 



381. Neon wave lengths 349 



382. Standard solar wave lengths. International Angstroms 350 



383. Provisional ultra-violet and infra-red solar wave lengths 353 



384. Reduction of wave-length measures to standard conditions .... 354 



385. Spectra of the elements 355 



Indices of Refraction 



Index of refraction of glass: « x — «d and n G ' — n D 356 



" , effect of composition on 356 



Derivation of partial dispersions of glass from n F — n c 357 



Index of refraction of glasses (American) 358 



Dispersion of glasses of Table 389 358 



Index of refraction of glasses made by Schott and Gen, Jena . . . 359 



iiv, Dispersion and density of Jena glasses 359 



Change of indices for i° C [for some Jena glasses] 359 



Index of refraction: Rock salt in air 360 



" " " Change of, for 1° C [for rock salt] .... 360 



" " " Silvite (potassium chloride) in air ... . 360 



" " " Fluorite in air 361 



" " " Change of, for i° C [for fluorite] .... 361 



" " " Iceland spar (CaCO s ) in air 361 



" " Nitroso-dimethyl-aniline 361 



" " " Quartz (SiO a ), 18 C 362 



Various alums 362 



Selected monorefringent or isotropic minerals. 363 

 Miscellaneous monorefringent or isotropic 



solids 364 



Index of refraction : Selected uniaxial minerals : (a) Positive . . 365 



(b) Negative . 365 



Miscellaneous uniaxial crystals 366 



Selected biaxial minerals: (a) Positive . . 367 



(b) Negative . 368 



Miscellaneous biaxial crystals 370 



Liquefied gases, oils, fats, waxes 370 



Liquids relative to air 371 



Relative to air for solutions of salts and acids. 372 



Gases and vapors 373 



Air (15 C,j6 cm) ; corrections for reducing 



wave lengths and frequencies in air to vacuo 374 



Media for determinations of refractive indices with the microscope : 



Liquids with ;z D (0.589^) = 1.74 to 1.87 375 



Media for determinations of refractive indices with the microscope : 



Resinlike substances, w D (0.589ft) = 1.68 to 2.10 375 



