252 



r=\101l smaller than s -=z \201\ and a = \100\; / = i021| and 

 iü = \04:l\, both equally large and greater than 6 ^ |010| ;</ = |Ori|, 

 commonly absent, but if present, rather large; m=\liO\, absent 

 in almost every case, always small and receding into the background, 

 undoubtedly the crystals are isomorphous with those of the optic- 

 ally active cobalti-salts, w^hose expected bisphenoidical symmetry' did 

 not reveal itself in any distinct way either. The rather appreciable 

 divergence of the values a:lj of the salts, as well as the differences 

 in shape and combined forms in the two cases, may probably be con- 

 nected with the eventually existing slight difference in the content 

 of water of crystallisation, mentioned previously. 



w 



00a 



00, 



Fig. 7 (1). 



Laevogyrate 



Tri-ethylenediamiiie-Rhodium-Iodide. 



Fig. 7 (2). 

 Laevogyrate 

 Tri-ethylenediamine Rhodium-Iodide. 



Angles: 



c:t =(001): (021) 



c:o =(001): (121) 



f.w =(021): (041) 



w.b =(041): (010) 



c\r =(001): (101) 



r:s =(101):(201) 



s:a =(201): (100) = 



o:o =(12J):(121) = 



o: o = (121):(121) = 



a: o =(100): (121) 



b:o =(010): (121) = 



t\0 =(021): (121) 



w.o =(041): (121) = 



b:q =(010): (Oil) = 



O-."' =(121): (121) 



No distinct cleavability could be observed. 



The external aspect of the crystals is almost isometrical, with a 

 slight flattening parallel to jOOlj, and a distinct elongation parallel 

 to the direction of the direction of the «-axis. 



The optical axes are situated in |001| ; the a-axis is first bisectrix. 



