63 



A distinct eleavage could not he observed. 



On {OOlj diagonal extinction : the crystals are not perceptibly 

 dieliroitic. The plane of the optical axis is |010} ; the r-axis is first 

 bisectrix. The apparent optical angle is very small. 



The specific gravity of the ci'ystals at 25'^ C. was pycnonietrically 

 determined r/4 , =: 2.270 ; the molecular volume is thus: 562.10. 



Topical parameters : •/ : if) ; w = 6.2532 : 7.1877 : 12.5070. 



IX. De.rtrof/yrafor;/ Luteo-Triethylenediamine-Cobalti-iodide. 

 Formula : \Co{Aein),\ ,/, + 1 H,0. 



This compound \Nas prepared by the precipitation of' a solution 

 of the dextrogyratory bromide with a concentrated solution of 

 potassium-iodide; the precipitate was washed out and recrystallised 

 from warm water. Analysis showed, that the compound, just like 

 the racemic one, crystallizes with 1 molecule of water. 



Long, dark-red, in transmitted light, blood-red needles, with lustrous 

 faces. All faces of the prism-zone, with the exception of those of 

 the forms {lOOj and |010}, are vertically striated; the vertical zone 

 furthermore shows many vicinal forms, which make it often diffi- 

 cult, to find the exact angular values, (fig. 10). 



Rhoinhic-hipijramidal. 



a:b:c = 0,8276 : 1 : 0,7386. 



Oh.ierred Forms: ?n = {340!, '''^ largest of all prism-faces, giving 

 like all prismatic faces, multiple reflections and diffraction-images ; 

 A ^ {OlOj, and a i^ jlOOj. somewhat narrower, but giving sharp 

 reflections; /> = |120[ and .v^{3.16.0j, both narrower than a, with 

 .V in most cases again smaller than p; (^ =: {Oil}, well developed, 

 but with rather appicciably oscillating angular \alues; r = {102j, 



