1233 
places round the central metal-atom, is well illustrated by the fact 
that not only do most of these salts possess a high crystallographic 
symmetry (vid. p.574 of the mentioned paper), but also, that in the 
case of the optically active components of the triethylenediamine- 
salts studied here, a rhombic or tetragonal symmetry is everywhere 
found, with a mean parameter-ratio oscillating between 0,82 and 
0,86. 
It is however evident at the same time, that the influence of the 
cation is undoubtedly varied by the presence of different anions : 
Br’, J’, NO’, CLO,’ and CNS’ in the solutions; and in particular 
it becomes evident, that the influence of halogen-, or halogen-con- 
taining anions, will differ appreciably from that of the ions NO,’ 
and CNS’. This difference manifests itself very plainly in the greater 
values of [mm] for the same wave-lengths, with salts of the first 
group, in comparison with those of the second group. 
This can most evidently be seen for those wave-lengths, for which 
the measurements can be made most accurately : 
ae yeti pial aes Differences Idem, for the rhodanides Differences 
AD sen) for the bromides, | rid: aat: | 
iodides and perchlorates: | L | & 
| | | 
6265 380° | 273° 
| 84 | 109 
6100 464 | 382 | 
106 100 
5910 570 | | 482 
| } 189 138 
5160 159 620 
242 | 211 
5595 1001 | 831 
The question, in how far this different influence is possibly linked 
directly with a not yet complete electrolytic dissociation in the 
solutions, could perhaps be answered by the determination of [7 | 
for infinite great dilutions; however, because of the embarrassing 
absorption in the coloured solutions, the measurements are not suffi- 
ciently accurate to elucidate this matter quite finally. 
§ 7. Whilé now by the foregoing investigations the positive and 
negative optical activity of these complex salts appears to occur 
beyond all doubt, if must now be our task to investigate the 
correctness of the second part of Pasteur’s conclusion also: in how 
far the results of the crystallographical research is able to demon- 
