Palladium, one of the rare metals, was first separated from native Platinum by Wollaston in 1803, and Was named after the planet Pallas, which had been discovered just before that time by Olbers. Hering, who made the first provings in 1850, says: “If we classify the Sulphides according to their solubility in dilute acids, Pallad. must be placed with Argentum, Rhodium, Ruthenium, and Osmium, and Platina remains with the less soluble Mercury, Aurum, and Iridium. Platinum and Palladium, both proved in dust form, showed such similarity in their effects that the question arose whether corresponding differences might be found.
The chief characteristic of Pallad. in the mental sphere is “Love of approbation,” which lays its victim an easy prey to slights real or imaginary, and easily gives place to a state of “wounded pride and fancied neglect”; irritability which often finds vent in violent expressions. Such a patient is > in society, and