#TheophilusPresbyter describes how the #blood of a #redhaired young man is necessary to create #gold from #copper, in a mixture with the #ashes of a #basilisk•Theophilus Presbyter (fl. c. 1070–1125) is the pseudonymous author or compiler of a Latin text containing detailed descriptions of various #medievalarts, a text commonly known as the Schedula diversarum artium ("List of various arts") or De diversis artibus ("On various arts"), probably first compiled between 1100 and 1120.•Theophilus' Schedula allows detailed insights into the techniques used in the applied arts in the high Middle Ages. The work is divided into three books. The first covers the production and use of painting and drawing materials (painting techniques, paints, and ink), especially for illumination of texts and painting of walls. The second deals with the production of stained glass and techniques of glass painting, while the last deals with various techniques of goldsmithing and other metalwork. It also includes an introduction into the building of organs. Theophilus contains perhaps the earliest reference to oil paint. The work has been translated into English, French, Polish, Portuguese, Spanish, Hungarian, German, Italian, Japanese, Bulgarian, and Russian, mostly in the 19th and 20th centuries.