in the Velocity of Propagation of Light in Water, 347 

 Table IV. — Indices of Refraction of Water. 



R. 





 2 

 4 

 6 

 8 



10 

 12 

 14 

 16 

 18 

 20 

 22 

 24 

 28 

 28 

 30 

 32 

 34 

 36 

 38 

 40 

 42 

 44 

 46 

 48 

 50 

 52 

 54 

 56 

 58 

 60 

 62 

 64 

 66 

 68 

 70 

 72 

 74 

 76 

 78 

 80 



Lithium- 

 line. 



1-33154 



1-33153 



1-33149 



1-33143 



1-33134 



1-33123 



1-33110 



1-33094 



1-33075 



1-33055 



1-33033 



1-33008 



1-32981 



1-32951 



1-32919 



1-32886 



1-32851 



1-32816 



1-32776 



1-32733 



1-32690 



1-32646 



1-32600 



1-32553 



1-32505 



1-32456 



1-32405 



1-32353 



1-32300 



1-32247 



4-32194 



1-32139 



1-32084 



1-32029 



1-31974 



1-31919 



1-31804 



1-31809 



1-31755 



1-31701 



1-31647 



Differ- 

 ence. 



Sodium- 

 line. 



1 

 4 

 6 

 9 

 11 

 13 

 16 

 19 

 20 

 22 

 25 

 27 

 30 

 32 

 33 

 35 

 35 

 40 

 43 

 43 

 44 

 46 

 47 

 48 

 49 

 51 

 52 

 53 

 53 

 53 

 53 

 55 

 55 

 55 

 55 

 55 

 55 

 54 

 54 

 54 



1-33374 



1-33373 



1-33369 



1-33363 



1-33354 



1-33342 



1-33328 



1-33312 



1-33294 



1-33273 



1-33250 



1-33225 



1-33197 



1-33166 



1-33134 



1-33101 



1-33065 



1-33026 



1-32986 



1-32944 



1-32901 



1-32853 



1-32810 



1-32762 



1-32713 



1-32662 



1-32611 



1-32558 



1-32505 



1-32451 



1-32397 



1-32342 



1-32287 



1-32232 



1-32177 



1-32121 



1-32086 



1-32012 



1-31958 



1-31905 



1-31853 



Differ, 

 ence. 



1 

 4 

 6 

 9 

 12 

 14 

 16 

 18 

 21 

 23 

 25 

 28 

 31 

 32 

 33 

 36 

 39 

 40 

 42 

 43 

 45 

 46 

 48 

 49 

 51 

 51 

 53 

 53 

 54 

 54 

 55 

 55 

 55 

 55 

 56 

 55 

 54 

 54 

 53 

 52 



Thallium- 

 line. 



1-33568 



1-33567 



1-33563 



1-33556 



1-33547 



1-33535 



1-33522 



1-33505 



1-33485 



1-33463 



1-33439 



1-33412 



1-33383 



1-33352 



1-33319 



1-33284 



1-33246 



1-33207 



1-33167 



1-33125 



1-33081 



1-33036 



1-32990 



1-32942 



1-32891 



1-32841 



1-32791 



1-32740 



1-32687 



1-32634 



1-32581 



1-32528 



1-32476 



1-32424 



1-32372 



1-32322 



1-32270 



1-32220 



1-32171 



1-32127 



1-32083 



Differ- 

 ence. 



1 

 4 

 7 

 9 

 12 

 13 

 17 

 20 

 22 

 24 

 27 

 29 

 31 

 33 

 35 

 38 

 39 

 40 

 42 

 44 

 45 

 46 

 48 

 51 

 50 

 50 

 51 

 53 

 53 

 53 

 53 

 52 

 52 

 52 

 50 

 52 

 50 

 49 

 44 

 44 



We must here remember that the above Table contains the 

 indices of refraction out of water into air of 7° and about 335"' 

 pressure. The relative indices must therefore be reduced to re- 

 fraction into vacuum (freier Aether). According* to Biot-Arago's 

 law, the refractive power {brechende Kraft) of the air (that is, 

 the square of the refractive index diminished by unity) is pro- 

 portional to the density. Accordingly for air, 

 2 const, b millim. 



?h ~ (l+a0 760millims. 



