Rhodium synonyms

In the following year he discovered rhodium; and at about the same time Smithson Tennant added two more to the list - iridium and osmium; the former was so named from the changing tints of its oxides (ipcs, rainbow), and the latter from the odour of its oxide (ovµA, smell).

Platinum itself he discovered how to work on a practical scale, and he is said to have made a fortune from the secret, which, however, he disclosed in a posthumous paper (1829); and he was the first to detect the metals palladium (1804)(1804) and rhodium (1805) in crude platinum.

But having failed, he allowed the paper, and also a second by Chevenix of the same tenor in 1805, to be read without avowing that it was he himself who had originally detected the metal, although he had an excellent opportunity of stating the fact in 1804 when he discussed the substance in the paper which announced the discovery of rhodium.

Aqua Regia, a mixture of nitric and hydrochloric acids, converts all metals (even gold, the "king of metals," whence the name) into chlorides, except only rhodium, iridium and ruthenium, which, when pure, are not attacked.