251 



attributed to the form ?^ = |112|, so that the value of h:c in the 

 former case is analogous to b -. 1c' in the present. 



Rhombic-bipyramidal. 

 a :/;:c=r 0,8541 :1 : 0.8632. 



Forms observed: o = |111|, predo- i^^ 

 minant and very lustrous ; c := 9s 

 |001|, also well-developed and giving- 

 splendid reflexes; w = \221\, very 

 narrow, but exactly measurable ; 

 g = 10411, s 

 often absent 



No distinct cleavage was found. 



When considered as a rhombic, but pseudo-tetragonal crystal, c 

 becomes jlOOj, and a-.b-.c — 1,0106 : 1 : 1,1708. 



§ 9. Laf,vogyrate Tr[-ëthylenediamine-rhodium-iodide. 



\Rlio{Aeine\\ 1, + V, H,0 0). 



Small, colourless and only feebly reflecting crystals, which are 

 however well measurable and possess constant angular values. 

 Occasionally very lustrous, nicely shaped and regularly developed 

 little crystals were met with. 



Rhombic ; perhaps bisphenoidicah although the geometrical appear- 

 ance is completely holohedral. 



a:b:c = 0,8064 : 1 : 0,7380. 



Forms observed: c = jOOlj, well-developed and lustrous ; ö = |121|, 

 and (o = |121|, almost equally large, and only very rarely to some- 

 what broader than o. This different size of o and to is the only 

 indication of the substance eventually being bisphenoidicah Further : 



17* 



