French dermatology was born at the Saint-Louis Hospital, created by Henri IV to accommodate plague sufferers. But the doctors face a real headache: how to teach students to recognize such or such skin disease? Doctor Lailler had the idea of ​​reproducing skin diseases using wax casts giving a relief representation of all skin conditions. He will meet a certain Jules Baretta, (1833-1923) a young manufacturer of fruit in wax for the windows of confectioners, installed in a stall in the passage Jouffroy. Instead of molding pears and bananas, Baretta will start molding yeast infections and pustules. He made his first molding in 1867. Today, with its 4807 waxes, the Baretta collection is the largest collection in the world of dermatological waxes!