338 
The values of the refractive indices found for air by Kayser and 
Runge 1 ] are given in the second column of the following table. 
Of the values given in the third column more will be said below. 
Observed by K. and R. 
Calculated 
a) 
À = 2,36 
... v = 1,00032159 . . . 
.— 
b) 
2.55 
31550 . . . 
v — 1,00031610 
«) 
2,85 
30911 . . . 
30979 
d) 
2,86 
30845 . . . 
30961 
e) 
3,25 
30325 . . . 
30416 
f ) 
4,20 
29637 . . . 
29697 
9) 
4.43 
29521 . . . 
29590 
h) 
5,63 
29238 . . . 
— 
The following values of the constant A have been found (applying 
(3), § 15) 
from (a) and (h) . . . 
A = 3,15 
...(b) and (g) . . . 
3,18 
• • • (c) and (/) . . . 
3,14 
...(d) and (e) . . . 
3^02 
The close approximation to constancy exhibited by these results 
shows that, at least on the basis of Kayser and Runge’s experi¬ 
ments, it would be useless to endeavour to discern between the 
/^s of oxygen and of nitrogen. 
From (a) and (h) the value D = 5230 can be deduced; with 
this value for D and A = 3,15 the numbers given in the third co¬ 
lumn of the above table have been calculated. 
The following are the results obtained by Perreau and by Mascart. 
a) 2 
— 4,677 . . . 
Perreau 
v — 1,0002953 ... 
Mascart 
V) 
4,800 . . . 
2951 . . . 
v = 1,0002953 
e) 
5,085 . . . 
2942 . . . 
2944 
d) 
5,378 . . . 
2935 . . . 
2938 
e) 
5,896 . . . 
2926 . . . 
2927 
/) 
6,438 . . . 
2917 . . . 
— 
0 Annalen d. Phys. u. Chemie, Bd. 50., p. 313. 1893- 
