Murexide was the last-discovered semi-synthetic dye. Strange and fantastic stories circulated about the origin of murexide: it was said that it was made from snake excrement. This is actually true; in 1818 William Prout obtained the dye from boa constrictor excrement. Twenty years later Justus Liebig and Friedrich Wöhler renamed the red-purple dye Murexide, an allusion to the murex mollusc which was the source of Tyrian purple in Antiquity. The name Murexide is connected to the scene from a myth in the Onomasticon of Julius Pollux, a second-century CE Graeco-Roman scholar and professor of rhetoric. The popularity of Murexide declined rapidly with the introduction of Perkin’s Mauveine; nevertheless, Murexide was a popular dye throughout Europe in the period 1853–1869.