Palladium was discovered in 1802 by the English chemist William Hyde Wollaston, who separated it from crude platinum and, unusually, first offered it for sale anonymously before disclosing his method. He named it after the asteroid Pallas, which the astronomer Heinrich Olbers had discovered only months earlier. Palladium is a soft, silvery-white member of the platinum group, remarkable for absorbing large volumes of hydrogen, and central to catalytic converters and electronics. Palladium's appetite for hydrogen and its power to speed reactions make it vital to exhaust catalysts, to hydrogen purification and to electronic components, and it is also worked, like the other platinum metals, into fine jewellery and dental alloys.
Wollaston's method of announcing palladium was unusually theatrical: in 1803 he had the mineral dealer Jacob Forster quietly offer samples for sale in a London shop as new silver, without revealing his own involvement, prompting the Irish chemist Richard Chenevix to publicly denounce the substance as a fraudulent alloy of platinum and mercury. Only in 1805 did Wollaston step forward, read a paper to the Royal Society, and claim credit, vindicating the discovery and embarrassing Chenevix, a rare case in the history of the periodic table where a new element was first launched not through a scientific journal but through an anonymous shop-window sale.