1232 
the passage of light between the wave-lengths 6600 A.U. and 4920 
A.U. The numbers for the two components were almost the same within 
the limits of experimental errors. The foregoing data are those 
obtained with the laevogyratory salt: (see p. 1231) 
For the sake of comparison the mean values of the molar rota- 
tions of the different salts are once more reviewed in the following 
table: 
Molar Rotation > 10—! 
Wave-length| el IEN EEN = 
in A. U. | 
| Bromides lodides = Nitrates Perchlorates, Rhodanides 
— | ! 
6750 a faethe | = = 
6000 Sides Aiba we ed? jage-7 |. Hersen fyi = 
6425 | 290 274 211 327 179° 
6265 | B75. il 357 2105 401 | 267 
6100 478 | 470 shied © 444 | 401 
5910 599 | 509 | Ae 515. 4 491 
5760 190 | EE 624 | 743 616 
5595 | 34 OTN ER SEP ae 810 | 999 781 
5420 | 1399 | 1435 ho AAS bp 1207 1330 
5260 | 1903 1843 | 1555 1804 wy 
BOBS.) 14) BTR, 2185 = {eat ORs a = 
4920 | 2705: «| — — | — | 2 
From this table, and from fig. 2, one can see immediately, that 
in the first place the enormous magnitude of the dispersion and the 
mean shape of the dispersion-curves manifest themselves in all cases 
in a quite analogous way; the predominant influence of the complex 
cation being thus placed beyond doubt. This predominant influence 
of the. spacial configuration of the complex ion in compounds of this 
kind, was, as L have previously had an opportunity (Zeits. f. Kryst. 
39, 575 (1904)) of showing, to a certainty brought to the fore by 
the fact that all these complex cobalti-salts reveal close crystallo- 
uomical family-relations: The probability for the assumption of an 
octahedral or pseudo-octahedral arrangement of the six coordination- 
