The Alchemist Discovering Phosphorus is a painting by Joseph Wright of Derby originally completed in 1771 then reworked in 1795. The full title of the painting is The Alchymist, in Search of the Philosopher's Stone, Discovers Phosphorus, and prays for the successful Conclusion of his operation, as was the custom of the Ancient Chymical Astrologers. It has been suggested that The Alchymist refers to the discovery of phosphorus by the Hamburg alchemist Hennig Brand in 1669. This story was often printed in popular chemical books in Wright's lifetime, and was widely known. Joseph Wright of Derby, 1771 — painted at 37. Canvas and oil paint. 127 × 101.6 cm. In the Derby Museum and Art Gallery. Wiki link