Hortus Sanitatis (Latin for ‘The Garden of Health’) is the first printed encyclopaedia of natural history, featuring sections devoted to plants, animals, birds, fish and stones. This hand-coloured woodcut illustration prefaces the section entitled De Lapidibus (‘On stones’), and it shows a Potions class. The Potions master is wearing an ermine-lined green cloak, clutching a stick in his left hand, with his assistant holding open a book of recipes. It is questionable how much attention the students are paying! Shown here: ff. Ee ii v–Ee iii r