Triple Chlorides Containing Silver and Gold. 477 



arrived at a variable composition for it, very far from the 

 correct one. 



E. Bayer 5 made a further and very satisfactory study 

 of Enrich 's microchemical tests, including the application 

 of cesium chloride for the purpose, and he attempted to 

 determine the composition of the two products containing 

 rubidium and cesium. After making six analyses of the 

 rubidium salt he came to the conclusion that it had the 

 formula Eb 6 Ag 2 Au 3 Cl 17 . This result is very interesting, 

 as this formula corresponds exactly to mine for Pollard's 

 ammonium compound, and, since the two things appear 

 to correspond closely in the color and form of their 

 crystals, it seems very probable that this formula is the 

 correct one. However, after obtaining astonishingly 

 variable results with the cesium salt, Bayer made two 

 more analyses of the rubidium compound, using products 

 only slightly freed from the liquid by suction on the filter 

 paper, and consequently contaminated to a greater extent 

 than usual with the mother-liquors which were rich in 

 rubidium chloride. He says that this was done because 

 it was only the proportion of silver to gold that he wished 

 to find. He thus obtained slightly varying results and 

 concluded that the rubidium salt also was a variable 

 compound. The following table gives his results, where 

 the last two analyses represent the more impure 

 products : 



Calculated for 

 Rb 6 Ag 2 Au 3 Cl 1T 



Kb, 26.66 







Bayer's Analyses 







27.3, 



27.5, 



26.6, 26.8, 26.9, 26.4, 



28.8, 



28.2 



Ag, 11.22 



12.2, 



12.0, 



11.0, 11.2, 11.1, 11.2. 



9.76, 



10.8 



Au, 30.77 



30.1, 



30.4, 



30.7, 30.5, 30.7, 30.9, 



31.1, 



30.7 



CI, 31.35 



31.6, 



31.7, 



31.2, 31.3, 31.5, 31.3, 



31.9, 



31.8 



From these results, considering the difficulty of purify- 

 ing such small crystals, and the nature of the last two 

 products, there can be no doubt that the compound has 

 a constant composition and that this is probably repre- 

 sented by the given formula. Moreover, the formula 

 Eb 3 (Ag 6 or Au 2 )Cl , which Bayer gives to the salt to 

 make it analogous to his results with the cesium com- 

 pound, agrees very poorly with the analyses, as can be 



5 Monatsh. f. Cliem., 41, 230, 1920. 



