478 Wells — Alleged Variable Composition of 



seen by referring to Bayer's article, where the atomic 

 ratios are given. 



Bayer gives no less than 14 analyses of the cesinm 

 salt, the results of which vary widely, particularly in 

 the percentages of silver and gold, and in no instance do 

 they correspond to my formula for the compound. The 

 variations may be shown as follows : 





Calulated for 



Bayer's extreme 





Cs 2 AgAuCl 6 



results 



Cs, 



33.90 



34.1—35.7 



Ag, 



13.77 



3.9—10.9 



An, 



25.17 



27.6—32.2 



CI, 



27.16 



27.4—28.2 



The most reasonable explanation of Bayer's results 

 is that he analyzed mixtures, and it appears to be 

 absolutely certain that his products were such from his 

 statement 6 that the crystals of the cesium compound 

 showed different colors, varying from black, through 

 violet, to dark brown, since the salt, as prepared and 

 analyzed by me, was entirely and absolutely black, even 

 in the finest state of division. 



From the wide variations in the percentages of silver 

 it appears that Bayer's mixtures contained a constituent 

 that was free from that metal, and the double salt 

 Cs 5 Au 8 Cl 14 , recently described 7 by me, is the probable 

 impurity, as it is very slightly soluble in strong hydro- 

 chloric acid containing a rather large amount of cesium 

 chloride, so that it would be expected to be deposited 

 with the black triple salt under the conditions employed 

 by Bayer, where gold and cesium were in excess over the 

 silver required for the formation of the black compound, 

 and where strong hydrochloric acid was employed as the 

 solvent. 



The following calculations have been made to find how 

 well Bayer's results agree with the mixture that has 

 been mentioned, the proportions of the two salts being 

 based upon the percentage of silver : 



6 Loc. tit., p. 241. 



7 This Journal, 3, 414, 1922. 



