De la baguette divinatoire, du pendule dit explorateur et des tables tournantes

Michel-Eugene Chevreul was a French chemist, and this 1854 work is his own classical scientific demonstration that the movement of a dowsing rod or a pendulum is produced by small unconscious muscular action on the part of the person holding it, not by any external force, and that the movement stops when the holder is prevented from seeing the result. Its authority comes from its historical priority and its experimental method, this is among the earliest controlled demonstrations of what is now called the ideomotor effect, still cited in modern discussion of dowsing and facilitated communication. Its limit is scope and language, it addresses the specific mechanism of pendulum and rod movement in 1854 Paris, not later psychological research on the same effect, and it is written in French, so an English-language claim drawn from it should note that it rests on translation.