On the refraction and dispersion of sulphur dioxide and hydrogen sulphide, and their relation to those of their constituents

The refractive index of sulphur dioxide for a single wave-length has been measured several times, and in a recent paper it was shown that nearly all the values, when corrected for density, approximated toμ –1=0·000661 for sodium light. The dispersion has only been measured once, by Ketteler, who found the numbers given in the second column below— When corrected for density, these become the numbers given in the third column.