As the theoretical corrosion (potential-pH) diagram shows, palladium metal is thermodynamically stable at all pH's in the presence of aqueous solutions free from strong oxidizing, reducing, or com-plexing agents [1]. In practice, palladium is acted upon by water only at high temperatures [2] and it does not tarnish when exposed to moist air. Moreover, at ordinary temperatures this metal is not attacked by nonoxidizing acidic solutions.