CRYSTALLOGRAPHICAL RELATIONSHIP 259 



The crystallographical data are as follows : 



System : Rhombic bipyramidal. 



Axial constants : a : b : c='9725 : 1 : 1-4065. 



Forms present : |100j, |101|, |120j, JOllj. 

 Twinning on |110j. 

 S. G.=3-037 at 20. 



The analyses of the carefully dried powder gave the follow- 

 ing results : 



Rb. In. 01. H 2 



35-01 23-92 35-32 1'46 

 Calculated 35-52 23-86 36-87 2-75. 



The values for chlorine and for water are both low. The 

 water of crystallisation is held firmly in this salt, and is 

 probably not entirely driven off even at 200. For some 

 reason not fully understood, the method of analysis adopted 

 for this series of isomorphous salts gave consistently low 

 results for the halogen. 



Cs 2 InCl 5 H 2 O 



The crystals of this salt, which were obtained on allowing 

 a solution which contained CsCl and Ind s in the proportion 

 2 : 1 to evaporate at laboratory temperatures, were very 

 simple in type. They represented a combination of the two 

 forms (101| and JOllj, usually equally developed (Fig. 11), 

 so that the crystals appeared cubic, developed on jlllj. 



