226 H. L. Wells — Ccssium- Mercuric Halides. 



lizations from water of all the double chlorides. This form 

 can be recrystallized from water indefinitely. 



The compound is practically insoluble in absolute alcohol, 

 but it dissolves in alcohol diluted with about one-third of its 

 volume of water, and it is remarkable that the cubic form is 

 deposited from such a solution on cooling. 



The cubes often form peculiar aggregates, apparently of a 

 pyramidal shape. The orthorhombic crystals are very brilliant 

 and highly modified, usually forming groups of spear-shaped 

 individuals joined end to end. 



Three samples were analyzed ; A, cubes simply dried on 

 paper ; B, cubes from alcohol ; 0, orthorhombic 'crystals, air- 

 dry. 



Calculated for 

 -CsHgCl 3 



' 30-26 

 45-51 

 24-23 



o-oo 







Found. 







A 



B 



G 



Caesium 



.. 30-29 



30-26 



29-92 



Mercury 



.. 44-80 







45-63 



Chlorine - . 



.. 28-40 



- . . . 



24-03 



Water 



1.42 











99-91 99-58 100-00 



Since the orthorhombic form of this compound is not de- 

 composed by water its solubility could be determined. This 

 was done by analyzing the mother-liquor from a third recrys- 

 tallization at about 17°. Of this solution, 100 parts contained 

 0*4255 parts of caesium, corresponding to 1-406 parts of 

 GsHgCl 8 . 



CsHg 2 Cl b was made by dissolving 24 g. of CsHgCl 3 and 16 g. 

 of HgCJ 2 (a little more than one molecule of the latter) in 

 about 150 c. c. of hot water and cooling. A large crop of 

 needles was obtained which were undoubtedly homogeneous. 



Analysis Calculated for 



gave. CsHg 2 Cl 6 . 



Caesium 18-13 18*72 



Mercurv 56-32 5630 



Chlorine - 24-68 24-98 



99-13 10000 



The salt is not very readily decomposed by water, but by 

 repeated recrystallization the orthorhombic form of CsHgCl 3 

 is obtained. 



CsHg^Cl^ was prepared by making a nearly saturated solu- 

 tion of 12-5 g. of HgCsCl s and 38-5 g. of HgCl 2 (about one 

 molecule of CsCl to six of HgCl„) in boiling water and cool- 

 ing. The compound was obtained in prisms, so well formed 



