In 1800, Wollaston made a partnership with Smithson Tennant for developing and improving the technology of platinum refining. These scientists worked for over 15 years in the treatment of South American ores. The first step of the purification process was the addition of aqua regia to the imported mineral. The precipitate compound was then removed and the resulting solution was initially thrown away. However, Wollaston studied this solution leading to the discovery of palladium, in 1803, and of rhodium, in 1804. Wollaston added mercury cyanide to the solution and got an yellowish precipitate. After several purification processes he washed the residue and obtained a white metal. This new element was named palladium in honor of the newly discovered asteroid Pallas.