A THEORY OF THE DISPERSION OF LIGHT 
19 
Quartz. Rudberg. 
The edge of the prism parallel to the axis of the Rhom- 
bohedron. Extraordinary Ray. 
Ray. 
Observed value 
of p. 
G> 
Ratio ( 4^-Y 
Calculated value 
of | u. 
= const, xflll) 
Vsine^' 
o / // 
B 
1-5499 
10 33 0 
1-0056 
1-5497 
C 
1-5508 
114 0 
1-00635 
1-5508 
D 
1-5533 
12 19 30 
1-008 
1-5533 
E 
1-5563 
13 46 50 
1-0097 
1-5560 
F 
1-5589 
14 56 50 
1-0114 
1-5585 
G 
1-5636 
16 53 15 
1-0147 
1-5636 
H 
1-5677 
18 18 30 
1-0173 
1-5677 
const. = 1-541 
Ordinary Ray. 
B 
1-5409 
10 20 0 
1-0054 
1-5409 
C 
1-5418 
10 50 30 
1-006 
1-5418 
D 
1-5442 
12 4 20 
1-0075 
1-5442 
E 
1-5471 
13 30 0 
1-0093 
1-5469 
F 
1-5496 
14 38 15 
1-0109 
1-5493 
G 
1-5542 
16 32 45 
1-0141 
1-5541 
H 
1-5582 
17 56 0 
1-0166 
1-5582 
const. = 1-5326 
Aragonite. Rudberg. 
Ray in the direction of the axes of elasticity. 
First Axis. 
B 
1-5275 
9 40 0 
1-0047 
1.5275 
C 
1-5282 
10 8 27 
1-0051 
1-5282 
D 
1-5301 
11 17 34< 
1-0065 
1-5303 
E 
1-5326 
12 37 40 
1-0081 
1-5328 
F 
1-5348 
13 41 25 
1-0095 
1-5348 
G 
1-5388 
15 28 33 
1-0123 
1-5390 
H 
1-5423 
16 46 36 
1-0144 
1-5424 
const. = 1-5204 
Second Axis. 
B 
1-6763 
12 50 0 
1-0084 
1-6763 
C 
1-6778 
13 27 53 
1-0092 
1-6776 
D 
1-6816 
14 59 35 
1-0115 
1-6815 
E 
1-6863 
16 45 56 
1-0144 
1-6863 
F 
1-6905 
18 10 42 
1-0168 
1-6903 
G 
1-6984 
20 32 55 
1-0217 
1-6984 
H 
1-7051 
22 16 27 
1-0257 
1-7050 
const. = 1-6623 
Third Axis. 
B 
1-6806 
13 0 0 
1-0086 
1-6805 
C 
1-6820 
13 38 20 
1-0095 
1-6820 
D 
1-6859 
15 11 17 
1-0118 
1-6858 
E 
1-6908 
16 59 0 
1-0148 
1-6908 
F 
1-6951 
18 24 45 
1-0175 
1-6952 
G 
1-7032 
20 48 52 
1-0223 
1-7033 
H 
1-7101 
22 33 50 
1-0263 
1-7101 
const. = 1-6662 
D 2 
