258 Wells — Complex Chlorides containing Gold. 



acid, agitating and draining. In one case (analysis VI) 

 where the crop had been deposited from a solution diluted 

 to an unusual extent with concentrated hydrochloric acid 

 no washing was done, for the sake of comparison. In all 

 cases the products were rapidly pressed between smooth 

 filter papers until the latter were no longer moistened by 

 the operation and then they were dried in the air. There 

 was practically no further loss in weight upon drying 

 at 100°. 



The crystals obtained were always very small, usually 

 not over 1 or 2 mm. in diameter. The larger ones were 

 very dark brownish-red in color, but evidently transpar- 

 ent, while the smaller ones were not so dark. Pollard has 

 called the color purplish-brown. The crystals are beauti- 

 ful and brilliant, and a description of their orthorhombic 

 form is given in Pollard's article. 



The salt is quickly decomposed by water, but it appears 

 to be stable in the presence of strong hydrochloric acid, as 

 was observed by Pollard. 



The following analyses of separate crops were made : 



NH 4 



Ag . 

 Au . 



Prepared by 

 hot evaporation 



I. 



7.02 a 

 14.31 



38.89 



II. 



14.19 



38.80 



CI .... 39.47 



Prepared by 

 cooling 



Calculated for 



III. IV. V. VI. (NH 4 ) 6 AgoAu 3 Cl 17 



7.09 a 7.13 



13.61 14.03 14.47 14.16 14.21 



39.67 38.84 38.54 38.62 38.96 



39.82 39.70 



99.69 100.19 



a Calculated from the excess of chlorine. 



100.00 



Pollard found 



NH 4 6.88 



Ag 15.58 



Au 37.99 



CI 39.44 



99.89 



Calculated for 



(NH 4 ) s Ag 3 Au 4 Cl 2 



6.97 



15.62 



38.06 



39.35 



100.00 



Pollard 's formula 

 differs from new one 



— 0.16 

 + 1.41 



— 0.90 



— 0.35 



The analyses in the present investigation were made by 

 decomposing the salt with a liberal amount of water by 

 the aid of heat, cooling, collecting the silver chloride in a 

 Gooch crucible and weighing it, precipitating the gold in 



