Tennant announces iridium and osmium; Wollaston reveals palladium (June 1804)

Background. Smithson Tennant analyzed insoluble residues from platinum ores in 1803, concluding they contained new metals. French chemists observed similar residues but lacked sufficient material for further experiments. Tennant named osmium for its volatile oxide's smell. Wollaston noted palladium in his lab book in July 1802 and named it in August, offering it anonymously in Soho in April 1803.

Royal Society Announcement. The discovery of iridium and osmium was documented in a letter to the Royal Society on June 21, 1804. This formalized Tennant's findings from the previous year. The event highlights the collaborative yet competitive nature of early 19th-century chemistry, where discoveries were often contested or attributed anonymously before formal recognition.

Palladium Revelation. William Hyde Wollaston faced criticism from Richard Chenevix, who claimed palladium was an alloy. Chenevix received the Copley Medal in 1803. Wollaston published work on rhodium in 1804 mentioning palladium, but only disclosed his authorship of palladium in a publication in 1805, correcting the legacy claim of a June 1804 revelation.