518 



TABLE 533.— INDEX OF REFRACTION OF QUARTZ (SiO a ), 15°C 181 « 



1811 Sosman, Robt. B., The properties of silica, p. 591, Chemical Catalog Co., NewYork, 1927. 



TABLE 534.— INDEX OF REFRACTION OF ROCK SALT IN AIR 



SMITHSONIAN PHYSICAL TABLES 



