English chemist and physicist who formulated a table of relative particle weights known as "chemical equivalents," similar to the table of Davy. In his studies of platinum, he isolated two new metals which he named palladium (after the newly-discovered asteroid Pallas) and rhodium (after the Greek word the rose color of some of its compounds). He was also one of the first to observe ultraviolet radiation, and in 1801 discovered dark lines in the solar spectrum (the first observation of spectral lines), later investigated by Fraunhofer.

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