The first alchemist whose name we know is said to have been Mary the Jewess (c. 200 A.D.). Early sources claim that Mary (or Maria) devised a number of improvements to alchemical equipment and tools as well as novel techniques in chemistry. Her best known advances were in heating and distillation processes. The laboratory water-bath, known eponymously (especially in France) as the bain-marie, is said to have been invented or at least improved by her. Essentially a double-boiler, it was (and is) used in chemistry for processes that require gentle heating. The tribikos (a modified distillation apparatus) and the kerotakis (a more intricate apparatus used especially for sublimations) are two other advancements in the process of distillation that are credited to her. Although we have no writing from Mary herself, she is known from the early-fourth-century writings of Zosimos of Panopolis.