29 
(^different Species ^ Glass. 
TT n ¥ (i^ + 4^ 4- DE) 
“ sin i 4* ’ 
and for the ray F, 
T 7 ^ sin ^ ^ 4 4" I^F 4- EF) 
JC 'll — —————— r _— — — — , 
sin ^ 4 
The following Table contains the indices of refraction for the 
different coloured rays in each refracting substance. 
Refracting 
Media. 
B n 
C n 
D n 
E n 
F n 
Ga 
Ha 
Flint glass, 
No. 13. 
1.627749 
1.629681 
1.635036 
1.642024 
1.648260 
1.660285 
1.671062 ^ 
Crown glass. 
No. 9. 
1.525832 
1.526849 
1.52958? 
1.533005 
1.536052 
1.541657 
1.546566 
Water, 
1.330935 
1.331712 
1.333577 
1.335851 
1.337818 
1.341293 
1.344177 
Water, - 
1.330977 
1.331709 
1.333577 
1.335849 
1.337788 
1.341261 
1.344162 
Kali, - 
1.399629 
1.400515 
1.402805 
1.405632 
1.408082 
1.412579 
1.416368 
Oil of Tur- 
pentine, 
1.470496 
1.471530 
1.474434 
1.478353 
1.481736 
1.488198 
1.493874 
Flint glass. 
No. 3. 
1.602042 
1.603800 
1.608494 
1.614532 
1.620042 
1.630772 
1.640373 
Flint glass. 
No. 30, 
1.623570 
1.625477 
1.630585 
1.637356 
1.643466 
1.655406 
1.666072 
Grown glass,. 
No. 30. 
1.524312 
1.525299 
1.527982 
1.531372 
1.534337 
1.539908 
1.544684 
Crown glass, 
M. 
1.554774 
1.555933 
1.559075 
1.563150 
1.566741 
1.573535 
1.579470 
Flint glass. 
No. 23. 
Prism of 60°, 
1.626596 
1.628469 
1.633667 
1.640495 
1.646756 
1.658848 
1.669686 
Flint glass, 
No. 23. 
Prismof45°, 
1.626564 
1.628451 
1.633666 
1.640544 
1.646780 
1.658849 
1.669680 
The following Table contains the ratios of the different dis- 
persive powers of the differently coloured rays, in several com- 
binations of the refracting substances, according to the results 
in the preceding Table, 
' ^ 
'i 
