Two new compounds have been found in museum samples of mauveine, the distinctive purple dye that serendipitously launched the synthetic dye industry 150 years ago (Chem. Commun., DOI: 10.1039/b618926a). In 1856, British chemist William Henry Perkin accidentally invented mauveine while working on a synthesis of the antimalarial drug quinine. The 18-year-old undergraduate subsequently abandoned his studies to commercialize the dye. Perkin was unable to establish the composition of mauveine, but he knew it consisted of more than one aniline-based compound. In 1994, researchers identified two mauveine isomers by NMR spectroscopy. A team led by JoÁo S. Seixas de Melo of the University of Coimbra, in Portugal, now reports using high-performance liquid chromatography to identify two additional mauveine compounds (one shown). The four mauveine compounds now known differ from one another in the number of methyl groups (two, three, or four) and their locations. The team confirmed its findings by using Perkin's original mauveine recipe to synthesize and characterize a new sample.