12 DE. GLADSTONE ON THE EEEBACTION-EQUIVALENTS OF THE ELEMENTS 
Table III. — Ternary and other Compounds. 
Part 
of 
spectrum. 
Befractive 
index. 
Authority 
for 
index. 
Befraction- 
equivalent. 
A 
1-3615 
Gladstone 
20-857*' 
D 
1-3655 
21-084* 
H 
1-3769 
21-745* 
A 
1-3817 
33-89 
A 
1-4073 
56-29 
Bed 
1-4240 
DelfFs 
111-5 
B 
1 -362552 
Sauber 
25-57 
B 
1-3768 
30-94 
Bed 
1-381 
Jamin 
31-17 
A 
1-4065 
Gladstone and Dale 
54 01 
A 
1-3779 
45-86 
A 
1-3781 
84-38 
A 
1 3676 
65-95 
A 
1-4597 
Gladstone 
64-69 
A 
1-5229 
40-54 
A 
1-5162 
Gladstone and Dale 
54-48 
Bright 
1-541 
Brewster 
119-3 
,, 
1001159 
Dulong 
25 64 
A 
1-4400 
Gladstone and Dale 
35-25 
A 
1-5135 
52-13 
A 
1-5563 
69-62 
C 
1-44201 
Haagen 
34-84 
A 
1-4619 
Gladstone and Dale 
43-51 
A 
1-5430 
53-73 
A 
1-5809 
59-28 
A 
1-5554 
53-31 
C 
1-42132 
Ilaagen . . .") 
31-46 
B 
1-4138 
Sauber 
32-15 
C 
1-43856 
Ilaagen 
54-98 
c 
1-53389 
45-98 
Bed 
1-532 
Jamin 
45-82 
A 
1-5171 
Gladstone and Dale 
33-50 
C 
1-52434 
Ilaagen 
32-89 
c 
1-50812 
Jamin 
40-96 
Bed 
1-503 
4081 
A 
1-5026 
Gladstone and Dale 
40-78 
A 
1-4934 
48-99 
A 
1-4804 
63-62 
C 
1-48714 
Haagen 
65-46 
Bed 
1-461 
Jamin 
45-3 
A 
1-3996 
Gladstone 
61-76 
A 
1 4205 
21-90 
A 
1-4047 
16-46 
Bright 
1 625 
Brewster 
22-08 
A 
1-4810 
Gladstone and Dale 
43-79 
A 
1-6143 
Gladstone 
57-96 
A 
1-5177 
11 
42-08 
Bright 
1-758 
Brewster 
57-0 
1 6352 
Malus 
33-29 
1-6468 
33-90 
11 
1-346 
Brewster 
24-63 
11 
1-458 
Wollaston 
126-78 
1-961 
Brewster 
39-22 
„ 
2015 
„ 
41-42 
11 
1-475 

45-8+60 
" 
1-586 
11 
117-28+18 
Substance. 
Formula. 
Alcohol 
Methylated Acetone 
Butyrone 
Laurostearate of Ethyl 
Cyanide „ 
Nitrate „ 
Amyl 
Carbonic Ether 
Silicic 
Boracic „ 
Triethylarsine 
Mercuric Methyl 
„ Ethyl 
Cane-sugar 
Phosgene 
Chloroform 
Chlorobenzole 
Trichlorobenzole 
Bichloride of Ethylene 
„ Chlorethylene 
Bibromide ,, 
,, Bromethylene 
Bromoform 
Bromide of Ethyl 
,, Amyl 
Bibromide of Ethylene 
Iodide of Methyl 
Ethyl 
Propyl 
Amyl 
Chloral 
Phosphite of Ethyl 
Sulphuric Acid 
Nitric Acid 
Chloride of Ammonium 
Oxychloride of Phosphorus. . . . 
„ Vanadium .... 
,, Chromium 
Nitrate of Lead 
Sulphate of Barium (ord. ray) 
„ „ (ext. ray) 
Kryolite 
Alum 
Zircon, least .... 
„ greatest. 
Borax 
Ferrocvanide of Potassium . 
c 2 H 6 o 
c 4 h 8 o 
c 7 n u o 
c 10 h b (C 2 H 5 )0 
c./h 5 cn * 
c 2 h 5 no 3 
C 5 11,'j NO, TT" 
(C 2 H 5 ) 2 C0 3 .... 
(C„H 5 ) 4 Si O t .... 
(C 2 H 5 ) 3 B 2 0 3 .... 
As (C„ HA, 
Hg(CH 3 ) 2 
Hg(C 2 H 5 ) 2 
^ 12 ^- 22^11 
CO Cl, 
chci; 
C e H- Cl 
C e H 3 Cl 3 
C 2 H t Cl 2 
C 2 H 3 C1 3 
C 2 H 3 Cl Br, .... 
C* H 3 Br 3 “. 
ClIBr, 
C,H 5 Br 
c ; h’ Br"":::::: 
0 2 H 4 Br 2 
ch 3 i ::::::: 
c 2 h 5 i 
c,h 7 i ::::::::: 
c 5 h u i 
c 2 hci 3 o ::::::: 
3(C, Hj) P0 3 .... 
II, SO t 
HNO, 
Nil, Cl 
POCI, 
VOCl 3 
CrO,Cl 2 
Pb2(N0’ 3 ) 
Ba S0 4 
Na”AiF’:::::::::: 
KAl, 2S0 4 ,1 
12H 2 0 ) • 
Zr Si 0 4 
Na,B. l 0 7 ',l 
10H, O J 
K 1 Fe(CN) 6 , 1 
3H 2 0 J ■' 
Solutions. 
If the refraction-equivalent of a mixture or of a chemical compound be the sum of 
the refraction-equivalents of its constituents, the same may be expected to hold good in 
the case of a solution. This consideration led me to examine a large number of aqueous 
* These are the numbers employed in calculating the alcoholic solutions given in Appendix III. 
