434 



Wells and Campbell — Double Chlorides, etc. 



Calculated for 

 Found. Cs 2 ZnCl 4 . 



Caesium 55*97 56*09 56'26 



Zinc ._ 13-49 13-87 13*72 



Chlorine 29*89 29*97 30*02 



Calculated for 

 Found. Cs 2 ZnBr 4 . 



Caesium _.. 40*68 4<>-86 



Zinc 9*53 9*72 9*98 



Bromine 49*30 49\17 49-16 



Calculated for 

 y Found. Cs s ZnI 4 . 



Caesium 31*49 31*55 3170 



Zinc 761 7-82 7*75 



Iodine 60*43 60*55 



Ccesium-Magnesium Chloride and Bromide, CsMgCl % . §Hfi 

 and CsMgBi\. 6U\0. — These salts form colorless, rectangular 

 plates or flat prisms which are often striated. A thorough 

 search gave no indications of salts of other types. The chlo- 

 ride is formed under a wide range of conditions, the bromide 

 under a much narrower range while no double iodide at all 

 could be prepared. 



The following analyses were made of separate products : 



Calculated for 

 Found. CsMgClg . 6H 2 0. 



Cs 37*14 35*66 35"77 



Mg 6-80 6-83 6-53 



CI 29-84 30-13 29-70 29'55 28 65 



H fl O 30*93 29 05 



Calculated for 

 Found. CsMgBr 3 . 6H 2 0. 



Cs _.. 27-23 27-67 26*32 



Mg 4*96 4*50 5-07 4*81 



Br 48-93 48*65 47'51 



H 2 18-32 22-33 21 "37 



It should be mentioned that Dr. H. L. Wheeler of this 

 laboratory has attempted to prepare a double chloride of 

 caesium and beryllium. He found that the simple salts 

 crystallized side by side from sufficiently concentrated solu- 

 tions, and there were no indications of the existence of any 

 double salt, even at rather low temperatures. It is therefore 

 evident that beryllium follows the rule, already indicated, that 

 in this family of bivalent elements, Be, Mg, Zn, Cd, Hg, the 

 tendency to form double halogen salts increases with their 

 atomic weights. 



Sheffield Scientific School. 

 New Haven, Conn., August, 1893. 



