This is the first book ever to focus exclusively on Marcel Duchamp's Pharmacie, the first rectified readymade in art history. The work has been largely neglected in the Duchamp literature, although it takes a key position in his radical artistic concept. Stefan Banz describes the emergence of the work, and compares the conceptual and optical differences between the three existing versions from the years 1914, 1937, and1945. In addition, he explores the significance of the term rectified readymade and discusses the philosophical dimension of this succinct, enigmatic, and cryptic work.