In the 1860s, Henri Robin’s theatre on the then-infamous Boulevard du Temple in Paris presented magic shows featuring ghostly visions from the beyond, and it also held one of the city’s allegedly most complete cabinets of physics. On Robin’s stage, the supernatural, the magical, and the scientific merged with one another to form a unique performance. Every evening at eight o’clock, the showman, or physicist as he preferred to call himself, entertained his audience with an act in which ghosts of the dead interacted with the living through a play of mirrors and optical illusions. This incredible performance was then followed by demonstrations of mechanical and electrical effects or shows on geology, archaeology, and various sorts of natural phenomena. Robin had a name for this type of entertainment: he called it scientific theatre. His establishment was not the only one in the capital at the time proposing magic shows that combined tricks and illusions with scientific learning. Since the 1840s, the renowned Theâtre-Robert-Houdin had featured shows of recreational physics and white magic where the public could witness a young boy levitating, spirits of the dead seemingly communicating with the audience, and basic physical experiments and chemical wonders, all in a single night. Some of the most accomplished magicians of the period had performed on its stage. Often calling themselves professors of amusing physics or professors of abstract sciences, these nineteenth-century conjurers continually shaped and reshaped the meanings of science and magic, stretching their boundaries to the needs of their presentations. By the second half of the nineteenth century, scientific learning and technological developments were being moulded and incorporated into the world of conjuring where they were given an aura of mystery and wonder for the amusement of the crowd. At the hands of the magicians, the popularization of science was entering the magic shows. Ambiguous boundaries between science and magic were not a novelty of the nineteenth-century magic shows. In his work on Parisian fairs a century earlier, the historian Robert Isherwood has argued that there was no clear distinction between science and magic in the popular mentality of the eighteenth century; that the crowds were equally fascinated by mechanical wizardry, magic lanterns, electrical healing, funambulism, fireworks, aerostatics, and phantasmagoria without much thought for what was white or black magic, technological developments, or tricks. Isherwood has successfully depicted the world of the eighteenth-century fairs and popular entertainment in all that it held of the mysterious and the marvellous for the public. Here, I suggest that this sense of wonder did not disappear in the following decades; that,