262 



INDIUM AND THALLIUM IN 



The following are the crystallographical data : 



System : Rhombic bipyramidal. 



Axial constants : a : b: c :='9803 : 1 : 1*3951. 



Forms present : jlOOj, J120J, jlOlj, jOllj. 



S. G.=3-409 at 20. 



The results of the analyses are as follows : 



Rb. In. Br. H S 



23-10 16-67 56-18 3-25 



Calculated 24'29 16-64 56-32 2'61 



Rb 2 InBr 6 H 2 O 

 Fio. 13 



., H 2 O 

 Fio. 14 



Cs 2 InBr 6 H 2 



From solutions which contained CsBr and InBr 3 in the 

 proportion 2:1, crystals of this salt were very easily obtained 

 on evaporation. They are very insoluble, colourless, and 

 markedly lustrous. The crystals are small and well formed, 

 and give good reflections. No evidence of twinning was found. 

 The general habit of the crystals somewhat resembles that 

 described for Rb 2 InBr 6 H 2 (Fig. 14). There is a marked 



