CHAP. XII. 



OF THE ATOMIC WEIGHTS OF GOLD, PLA- 

 TINUM, PALLADIUM, RHODIUM, AND IRI- 

 DIUM. 



THESE five metals possess many peculiar charac- 

 ters. Their oxides are easily reduced to the me- 

 tallic state by exposure to a red heat ; they have 

 little tendency to combine with acids and form 

 salts : the consequence is, that we know very 

 few saline compounds into which these oxides 

 enter, with the exception of certain triple com- 

 pounds, by means of which chiefly I have been 

 enabled to determine the atomic weights of these 

 metals, I trust with tolerable precision. 



SECT. I. 



OF THE ATOMIC WEIGHT OF GOLD. 



IT has been long known to all the world, that 

 gold dissolves with facility in aqua regia ; that 

 the solution has a yellow colour, an astringent 

 and very acrid taste ; and that when sufficiently 

 concentrated, it forms beautiful prismatic crys- 



Ee4 



