266 INDIUM AND THALLIUM IN 



The analyses gave the following results : 



K. 



8-46 

 Calculated 9-03 



Tl. Br. H,0 



31-74 55-05 4-75 



(diff.) 



31-42 55-30 4-16. 



COMPARISON OF DATA 



Full crystallographical details have been given in the 

 foregoing section for the members of two distinct series of 

 isomorphous salts (1) the ditetragonal bipyramidal series, 

 consisting of the following salts : K 3 T1C1 6 2H 2 0, (NH 4 ) 3 T1C1 6 

 2H 2 0, K 3 InCl 6 2H 2 O, Rb 3 TlBr 6 2H 2 0, to which may be 

 added K 3 InBr 6 2H 2 O, for which incomplete details are given ; 

 (2) the rhombic bipyramidal series, consisting of : Rb 2 TlCl 5 

 H 2 0, Cs 2 TlCl 6 H 2 O, (NH 4 ) 2 Ina 6 H 2 O, Rb 2 InCl 6 H 2 0, Cs 2 InCl 5 

 H 2 O, Rb 2 InBr 5 H 2 O, Cs 2 InBr 5 H 2 O, to which may be added 

 (NH 4 ) 2 InBr 5 H 2 0, for which incomplete details were obtained. 

 On referring to the literature it would appear that only one 

 other salt has been described which shows any marked 

 similarity in its crystallography to the members of the first 

 series, i.e., K 3 SbCl 3 Br 3 1H 2 0. This salt was obtained by 

 Atkinson and described by Solly (19), who gave the following 

 details : 



Class : Tetragonal bipyramidal. 



Crystal constants : a : c=l : '7629. 



Forms : jlllj, with occasionally small faces of jOOlj. 

 Although the estimated water value differs by half a 

 molecule from that given for the isomorphous series, and the 



