Tables 341-342. 



INDEX OF REFRACTION. 



TABLE 341 (Continued) . — Selected Uniaxial Minerals. 



285 



TABLE 342. — Miscellaneous Uniaxial Crystals. 



Crystal. 



Ammonium arseniate NH4H2ASO4 



BenzU (C6HsCO)2 



Corundum, M2O3, sapphire, ruby. 

 Ice at — 8°C 



Ivory 



Potassium arseniate KH2Ast04 . . , 



Sodium arseniate Na3As04.i2H20 , 



' nitrate NaNOs 



" phosphate Na3P04.i2H20 

 Nickel sulphate NiS04.6H20 



Strychnine sulphate 



Spectrum 

 line. 



Index of refraction. 



Ordinary 

 ray. 



t.5766 



1.6588 



t.769 



[.308 



[-297 



tS39 



1.5762 



1.5674 



t.5632 



t.457 



t.s86 



[.447 



[.5173 



[.5109 



[.5078 



t.614 



Extraordinary 



ray. 



[.5217 



[.6784 



[. 760 



[.313 



[.304 



t.541 



1.5252 



[•5179 



[.5146 



[.466 



[.336 



[.453 



[ . 4930 



[.4873 



1 . 4844 



[.599 



Authority. 



T. and C* 

 Mean 

 Osann 

 Meyer 



Kohlrausch 

 T. and C. 



Mean 

 T. and C. 

 Martin 



Smithsonian Tables- 



* Topsoe and Christiansen. 



