118 PelJfS^i' m ^^^d- 



nor even when hot, unless the temperature be sufficiently high, 

 and then the chloride decomposes, exactly as if no extraneous 

 acid had been present. 



The acids do not act on the chloride of gold, nor cause any 

 other decomposition than that due to the water they contain, 

 b^t with that water they act on the chloride, transforming it into 

 a chloride and metallic gold. 



On the Action of Acids on the Oxide of Gold. 



The oxide of gold used by M. Pelletier, is the per -oxide of 

 Berzelius, or the oxide of gold of those chemists who admit but 

 of one only. M. Pelletier found that the acids in general were 

 not capable of uniting to this oxide, and of forming saline com- 

 binations ; that the concentrated nitric, sulphuric, and acetic 

 acids easily dissolved the oxide when heated, but that the greater 

 part of it precipitated on cooling or dilution with water ; and 

 that the quantity remaining in solution was very small, and 

 incapable in any case of forming an auriferous saline compound. 

 The muriatic acid only possesses the property of energetically 

 dissolving the oxide, forming with it an incrystallizable chloride. 

 The hydriodic acid has an analogous action. M. Pelletier con- 

 cludes frona the experiments described in his paper, that there 

 are no salts of gold. 



Action of Salts on the Chloride of Gold. 



If the acids were susceptible of uniting to the oxide of gold, 

 observes M, Pelletier, to form true saline combinations, the 

 most favourable circumstances for their production would be in 

 the action of double affinities. Nevertheless M. Pelletier could 

 not, by this means, obtain any salts of gold. On pouring solu- 

 tions of sulphate of soda, phosphate of soda, <!^c., into solution 

 of the chloride of gold, nothing but mixtures were obtained. 



The soluble salts of silver as the nitrate and sulphate, acted 

 differently. When poured into a solution of the chloride of 

 gold, a yellow brown precipitate was obtained, and the fluid 

 became colourless: containing only nitric or sulphuric acid. 

 An analogous precipitate is produced by the muriate of plati- 



