249 



and their physical properties are so wonderful, that their detailed 

 study will still reveal many surprises. 



Fig. 165 for example may give some impression of the enormous 

 rotatory power and rotatory dispersion of the triethylenediamine- 

 cobalti-salts, which may be compared with the dispersion-curve 



Fig. 165. 



Rotatory dispersion of some optically active Triethylenediamine-Cobalti-salts. 



of ordinary cane-sugar, represented by the almost straight line 

 beneath *). Often abnormal dispersion-phenomena are also observed 

 here, e. g. in the case of the corresponding triethylenediamine-deri- 

 vatives, of the complex trioxalates of cobalt, chromium, rhodium, 



1) F. M. Jaeger, Proceed. Kon. Akad. v. Wet. Amsterdam, Vol. 17, 1231, (1915); 

 Receuil des Trav. Chim. d. Pays-Bas, 38, 171, (1919). On other physical properties 

 of these complex salts, as magnetic susceptibility, absorption, etc., conf. e.g.: 

 the recent paper of E. Rosenbohm, Zeits. f. phys. chemie, 93, 692, (1919). 



