705 



observed ; only once a crystal of the laevogy rsitory antipode presented 

 the righthandeó trigonal bipyramid .r = {2241 1 [715] as an extremely 

 narrow truncation of the edge R : m. From this it may be concluded, 

 that in this case too, the substance manifests only a very weak 

 tendency to present hemihedral forms, uiu-egarded the enormous 

 optical activity, which these salts exiiibit in aqueous solution; and, 

 moreover, that also in the case of the complex oxalates, the same 

 morphological relation between the cobalti- and the vhodiuvi-saMs 

 appears to exist, as between the corresponding cobalti- and rliodium- 

 trie thy hnediainine nitrates ^), in so far, as the oppositely rotating 

 cobalti- and rhodium-ssiUs, which are separated from the less soluble 

 compounds with optically-active bases (strychnine) or acids {tartaric 

 acid), yet exhibit hemihedral forms of the same algebraic sign -. 



Dextrogyratory Potassium- Cobalti- Oxalate (-f- IH^O). 



Fig 6. 



At the same time it is evident that the cobalti- and rhodiwn-saUs 



1) F. M. Jaegee, Proceed. Kon. Akad. v. Wet. Amsterdam, 20. 258, 261 (1917). 



46 

 Proceedings Royal Acad. Amsterdam. Vol. XXI. 



