70 



Amildar VkIih-.i; 

 c:q =(001): (011) = 

 r:q = (101) : (01 1 ) = 

 ,j:b =(011): (01(1) = 

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

 s:r =(201): (101) = 

 r: c — (101):(0()1) = 

 a: 7» =(100): (110) = 

 m:p =(110): (120) = 

 p:h = (120): (OKI) = 

 h:o — (010) :(121) = 

 o:v =(121): (101) = 

 ;':oj = (101):(lll) = 

 co:.. =(111):(121) = 



Fig. U. 



Laevogyratory 



Tiiethyleuediamine- 



Cobalti-rliodanide. 



A distinct cleavage could not be found. 



The optical properties are the same as indicated in the previous 

 case. 



Ths specific gravity of the crvsials was p_yciioinetricall\' determined 



Ihc molecidar \oliime is: 276.37. 



to be 



25° 

 ,1 ,, =1.496: 



Topical parnnu^lers / : tf : o, = 6.J979 : 7.2968 : 6.1110. 



Of a plate parallel to jOOlj we obtained a Rrmtgenogram which 

 nolwilhstanding its imperfectness, in every case showed the presence 

 of at least one plane of symmetrv. 



.\7 I". liitci'iiiic Luko- Trü'/fii/lf'iii'(liiniiii/e-Co/iii!/i-jii'rrhloj-(iic 

 Formula : |Co (Aein),| (CU),),. 



The salt was prepared by double decomposition l)etween the racemic 

 bromide and silver-perchlorate. 



It is rather difficult to obtain well developed crystals of this 

 compound ; commoid}' thin, rectangular, tabular crystals are obtained 

 possessing round edges and giving considerably oscillating angular 

 values; or lliey are complicated intergrowths of e.\treraely thin plates 

 arranged in rosettes. Between crossed nicols such intergrowths will 

 in no situation show a complete extinction, but lamellar polarisation 

 and high iriterference-colours, in some cases also a mosaic-like strncture : 



Finally we succeeded in making the neces.sary measuremenls with 

 the rectangular, tabular crystals. 



