( :^61 ) 



A)i<iiil(ii- ]^(il/(es: Measured: Calc/iin/ed : 



0:o=:(lJlj:(lÏJ)=:- (i2°4r — 



0:0 = (IIJ) : (111) = 94 417, 94° 427/ 

 0:0 = (111) : (111) = 85 1,S7._, 85 177, 



A distinct eleavaue was not tbuiul. 

 The compound is isoniorplious widi die polassiuni-sall. 

 The crystals are o[)lic:dly nionaxial ; the character of the (U)id)ie 

 refraction is positive. They exihibit no circular polarisation. 

 Topic parameters : / : if : oj :=^ 6,3197 : 6,8197 : 4,8522. 



III. Rl HIDIUM-SALT : RhCOJJCl, . HCOMCl,. 



Tiie analysis gave: 20,(38 7o ^^^'^ : calculated: 2(),(i5 7„. 



Sp. or. at 18° C, 2,150; molecular volume = 191,21. 



The tirst crystallisation-e.xperiments showed at once, tiial we wei'e 

 dealing here with crystals of a quite ditferent habit. Further inves- 

 tigation proved indeed that the Rh-^aXi has a form (piite ditferent 

 from that of the two former ones. 



Colourless, vei-y thin, elongated-hexanguhir little plates which 

 often form on the surface of the li(püd, or deposit on the walls of 

 the vessel. 



The crystals ai'e shown in Fig. 3. 



Forms observed 



Rubidium-Salt. 

 Fig. 3. 



Monocïinic-]n'isiii(itie. 

 rï: A :c= 1,4649:1 : 3,1596 



,'?^ 86° 357/. 

 c=|001{, large, lustrous and strongly [»redomi 



