spate 
: 
ES j * 
as is always the case with neutral solutions of ferric salts, but on 
acidulating with chlorohydric acid, it cleared up and the gold 
had disappeared. Another fragment also dissolved, and so on. 
The action is accompanied by the production of protochlorid of 
iron, as is easily shown by a solution of ferrideyanid. On fil- 
tration, dilution, and treatment with sulphohydric acid, the pre- 
Lo age obtained in the liquid had quite a dark brown color, and 
when washed, dried and burned on platinum foil, left a residue 
easily proved to be spongy gold by burnishing in an agate 
; A solution of pure ferric ulphate was also proved to dissolve 
a little gold, though less readily than the sesquichlorid, and to 
be reduced to ferrous sulphate. Even at the ordinary tempera- 
* Lieb. and Kopp’s Jahresb., 1853, p- 654. 
+ “Diese Reaction ist ungemein empfindlich.” Fresenius’s Anleitung zur qualita- 
tiven chemischen Analyse, Braunschweig, 1856, p. 175. 
