MONOCLINIC DOUBLE SELENATES OF THE NICKEL GROUP. 
231 
Table of Specific Refraction and Dispersion (Lorenz). 
Specific refraction, —k—d- 
- 7 = n. 
-j- /<) a 
Specific dispersion. 
I'G - HO 
Salt. 
For ray C (Ha). 
For ray Hy near G. 
cc. 
P- 
.7* 
' 
CC. 
P- 
7- 
a. 
P- 
7- 
AmNi selenate 
0-1366 
0-1385 
0-1404 
0-1404 
0-1422 
0-1442 
0*0038 
0-0037 
0-0038 
KNi 
0-1178 
0-1195 
0-1225 
0-1210 
0-1227 
0-1258 
0-0032 
0-0032 
0-0033 
RbNi 
0-1059 
0-1074 
0-1091 
0-1088 
0-1104 
0-1121 
0-0029 
0-0030 
0-0030 
CsNi 
0-1002 
0-1010 
0-1016 
0-1028 
0-1037 
0-1043 
0-0026 
0-0027 
0-0027 
Table of Molecular Refraction and Dispersion (Lorenz). 
* 
n i _ i 
Molecular refraction, —- . 
rfi + 2 
M 
~l = W ' 
Molecular dispersion. 
Salt. 
UlQ — Illc- 
For ray C (Ha). 
For ray Hy near G. 
CC. 
P- 
7- 
CL. 
P- 
7- 
CC. 
p. 
7- 
KNi selenate 
62-14 
63-04 
64-60 
63-82 
64-75 
66-37 
1-68 
1-71 
1-77 
RbNi „ 
65 -59 
66-57 
67-61 
67-39 
68-38 
69-47 
1-80 
1-81 
1-86 
AmNi ,, 
66-37 
67-27 
68-19 
68-18 
69-08 
70-03 
1-81 
1-81 
1-84 
CsNi ,, 
71-49 
72-09 
72-52 
73-37 
73-98 
74-44 
1-88 
1-89 
1-92 
Molecular Refraction (Gladstone and Dale). 
Salt. 
CC. 
h—d M for ray C 
cl 
p- 
7- 
Mean molecular 
refraction for ray C. 
7 (u + /3 + y). 
KNi selenate. 
106-10 
107-96 
111-10 
108-39 
RbNi „. 
112-08 
114-07 
116-20 
114-12 
AmNi ,,. 
113-70 
115-56 
117-45 
115-57 
CsNi ,,. 
122-90 
124-14 
125-03 
124-02 
The whole of the specific and molecular optical constants of rubidium nickel selenate 
are intermediate between those of potassium nickel selenate and caesium nickel selenate. 
VOL. CCXVII.-A. 
K 
