438 
DR. A. E. H. TUTTON ON THE 
Table of Specific Refraction and Dispersion (Lorenz). 
Salt. 
n' 2 - 1 
Specific refraction, —--- = n. 
(n 2 + 2) a 
Specific dispersion. 
n G - n c . 
For ray C (Ha). 
For ray Hy near G. 
a. 
P- 
7- 
CL. 
P- 
7- 
CL. 
P- 
7- 
AmFe selenate 
KFe „ 
RbFe ,, 
CsFe ,, 
0-1384 
0-1192 
0-1069 
0-1009 
0-1398 
0-1209 
0-1080 
0-1017 
0-1420 
0-1241 
0-1102 
0-1027 
0-1422 
0-1224 
0-1097 
0-1036 
0-1437 
0-1241 
0-1109 
0-1043 
0-1459 
0-1274 
0-1132 
0-1054 
0-0038 
0-0032 
0-0028 
0-0027 
0-0039 
0-0032 
0-0029 
0-0026 
0-0039 
0-0033 
0-0030 
0-0027 
Table of Molecular Refraction and Dispersion (Lorenz). 
Salt. 
2_ | 
Molecular refraction, —- . — = m. 
n 2 + 2 cl 
Molecular dispersion. 
m G - m c . 
For ray C (Ha). 
For ray Hy near G. 
CL. 
' P- 
7- 
CL. 
P- 
7- 
CL. 
P- 
7- 
KFe selenate 
RbFe 
AmFe ,, 
CsFe ,, 
62-55 
65- 93 
66- 81 
71-74 
63-43 
66 ■ 65 
67-50 
72-29 
65-10 
68-00 
68-59 
72-99 
64-21 
67-66 
68" 68 
73-64 
65-13 
68-41 
69 • 38 
74-16 
66-85 
69- 83 
70- 46 
74-91 
1-66 
1-73 
1 - 87 
1-90 
1-70 
1-76 
1-88 
1-87 
1-75 
1-83 
1-87 
1-92 
Molecular Refraction (Gladstone and Dale). 
7 
CL. 
1 ^ M for ray C. 
a 
P- ' 
7- 
Mean molecular 
refraction for ray C. 
| (a + /3 + y). 
KFe selenate. 
106-54 
108-33 
111-74 
108-87 
RbFe „ . 
112-44 
113-89 
116-65 
114-33 
AmFe .. 
114-21 
115-62 
117-87 
115-90 
CsFe ,,. 
122-99 
124-11 
• 125-56 
124-22 
On comparing the results for the molecular refraction of the iron group of double 
selenates with the similar ones for the iron group of double sulphates, # in order to 
* ‘ Roy. Soc. Proc.,’ A, vol. 88, p. 382 (1913). 
