THE 



AMERICAN JOURNAL OF SCIENCE 



[FIFTH SERIES.] 



Art. XXIX.— #G>me Complex Chlorides containing Gold; 

 by H. L. Wells. 



II. Cesium Triple Salts. 



[Contribution from the Sheffield Chemical Laboratory of Yale University.] 



Iii a preceding article 1 a re-investigation of Pollard's 

 ammonium-silver-auric chloride was described, and the 

 formula (NH 4 ) 6 Ag 2 Au 3 Cl 17 was ascribed to it. Upon 

 extending the investigation to the employment of cesium 

 chloride in the place of the ammonium salt a triple com- 

 pound, not corresponding to the ammonium salt, but with, 

 a simpler formula, Cs 2 AgAuCl 6 , has been obtained, while 

 several other triple salts apparently isomorphous with 

 this and forming an analogous series with it have been 

 prepared. 



The formulas of these five new triple chlorides, with 

 their colors, are as follows : 



Cs 4 Ag 2 Au /// 2 Cl 12 . Very black opaque, powder black. 

 Cs 4 ZnAu'" 2 Cl 12 . Yellow,* transparent, powder pale yellow. 

 Cs 4 HgAu /// 2 Cl 12 . Orange, transparent, powder yellow.. 

 Cs 4 CuAu / " 2 Cl 12 . Crystals black, powder pale brown. 

 Cs 4 Au / 2 Au'" 2 Cl 12 . Very black, opaque, powder black. 



a Sometimes red. 



The simplest formulas for the silver and aurous salts 

 have been doubled in order to make them correspond to 

 the others, for it has been found that the silver and zinc 

 salts evidently crystallize isomorphously, since the crys- 

 tals of their mixtures are uniformly black in color, even 

 when they contain a large proportion of the yellow zinc 

 compound, and there is similar isomorphism with the mer- 

 curic and aurous salts. This series of salts, therefore, 



1 This Journal, April number, 1922. 



Am. Jour. Sci. — Fifth Series, Vol. Ill, No. 17.— May, 1922. 

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