Haunted thoughts of the careful experimentalist: psychical research and the troubles of experimental physics.

This paper analyses the relationship between the 'elusive' science of psychical research and experimental physics in the period approximately, 1870-1930. Most studies of the relationship between psychical research and the established sciences have examined the ways in which psychical researchers used theories in the established sciences to give greater plausibility to their interpretations of such puzzling phenomena as telepathy, telekinesis and ectoplasm. A smaller literature has examined the use of laboratory instruments to produce scientific evidence for these phenomena. This paper argues that the cultures of experiment in the established science of physics could matter to psychical research in a different way: it suggests that experience of capricious effects, recalcitrant instruments and other problems of the physical laboratory made British physicists especially sympathetic towards the difficulties of the spiritualistic séance and other sites of psychical enquiry. In the wake of widely-reported claims that the mediums they had investigated had been exposed as frauds, these scientific practitioners were eventually persuaded by the merits of an older argument that human psychic subjects could not be treated like laboratory hardware. However, well into the twentieth century, they maintained that experimental physics had important lessons for psychical researchers.