255 



The colourless crystals always exhibit a distinctly hemimorphic 

 shape; the polar axis is the a-axis. The substance possesses a strong- 

 tendency to crystallisation, but the various individuals are in general 

 smaller than those of the corresponding cobaIü-sa.\t. 



The external aspect is in most cases rather isometrical, but 

 occasionally a slight elongation parallel to the direction of then-axis 

 could be stated. 



No distinct cleavage was observed. 



On jlOOj the optical extinction is parallel and perpendicular to 

 the c-axis. The plane of the optical axes is |010|. 



§ 12. Laevogyratory Tri-ethylenediamine-rhodium-?sitrate. 



\Rho{Eine\\yNO,\. 



This compound was prepared tVom the laevogyrate iodide by 

 means of silver-nitrate. It crystallises in beautiful, triangularly-shaped 

 plates, or, in most cases, in crystals of the form reproduced in fig. 9. 



The various individuals are distorted in most capricious ways, a 

 fact which to no slight degree opposes their investigation. 



Rhorabic-bisphenoidical. 

 a:b:c = 0,8642 : 1 : 0,6049. 



Forms observed: a = jlOOj and (7 = |111{, almost equally large; 

 r=r{101j, commonly present with only two faces; m:^\\.l% 



