Sulfuric acid the Hellenistic alchemical works of Zosimos of Panopolis, in the treatise "Phisica et Mystica", and the Leyden papyrus X. Medieval Islamic era alchemists, Jābir ibn Hayyān (c. 721 – c. 815 AD, also known as Geber), Razi (865 – 925 AD), and Jamal Din al-Watwat (d. 1318, wrote the book "Mabāhij al-fikar wa-manāhij al-'ibar"), included vitriol in their mineral classification lists. Ibn Sina focused on its medical uses and different varieties of vitriol. Sulfuric acid was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" (iron(II) sulfate) in an iron retort. There are
Oil paint Presbyter, a 12th-century German monk, recommended linseed oil but advocated against the use of olive oil due to its long drying time. Oil paint was mainly used as it is today in house decoration, as a tough waterproof cover for exposed woodwork, especially outdoors. In the 13th century, oil was used to detail tempera paintings. In the 14th century, Cennino Cennini described a painting technique utilizing tempera painting covered by light layers of oil. The slow-drying properties of organic oils were commonly known to early painters. However, the difficulty in acquiring and working the materials meant that they were rarely