Recent studies in nineteenth-century spiritualism have illuminated the social practice of the occult in various cultural contexts. Richard Noakes in his latest study on telegraphy and the occult in Victorian England, for instance, shows how the world of spiritualism and the world of technology were welded together by Victorian engineering schemes and money. 2 This paper looks at another culture of occult practice which has often been neglected by historians of science: the role of spiritism in the making of German (...) experimental psychology. Based on a debate focusing on the German astrophysicist Karl Friedrich Zöllner and the American medium Henry Slade, I will show how spiritistic experiments were situated in the emerging contexts of scientific practice, laboratories and disciplines. 3 This study will also take a close look at the perception of spiritistic mediums as instruments by experimenters such as Zöllner. 4Things were in control and then they were not and then they were.Sally Bushell, Under the Breadfruit Tree. (shrink)