( 798 ) 



Triclino-pinacoidal . 



a : b : c =1 1,3991 : 1 ; 1,6135 



A= 94° 12' « = 109^16' 



^ = 123^10' ^1=117° 36' 



C= 70" 4V; y= 62° 52' 



Fig. 5. 

 Tri-p-Jodo-Triphenylcarbinol + 1 Benzene. 



Forms observed : c= |001| and <t = jlOlj, equally strongly developed; 

 r =r |H)1|, broader than a and c and very lustrous; /> = jOlOj, well 

 developed; o ^ jlirj and m == |riO|, about equally large and giving 

 a good reflexion. 



The habit is elongated towards the 6-axis. The ratio 5 : c is prac- 

 tically twice that of the Tri-p-Jodotriphenolcarhinol itself. 

 a:c = (100) : (001) =* 56^50' - 



c:r=:(00J):(T01)=:*72 6 — 



c:b^ (001) : (OTO) =* 94 12 — 



a:6=(100):(OrO)=*70 4V, — 



c:o = (001) : (ill) =* 80 22 

 m. : = CrfO) : (111) == 39 22 39 .23^', 



7/i:c=(Il"0):(00J)=: 60 2 59.45 



No distinct cleavage. 



On |lT)l| the extinction amounts to about 32\/,° in regard to the 

 ^>axis. Sp. Gz. 2,079 at 17^; Equiv. Vol. = 344,39. 

 Topic axes : / : v^ : a> = 8,4070 : 6,0090 : 9,6950. 



Groningeriy March 1908. 



