The Chevreul Pendulum Test. Used in hypnosis to show the client the power of the mind and concentration.
Chevreul was curious about "the exploring pendulum" used to analyze chemical compounds, a method employed by his colleagues at the time.
Chevreul did what none of his predecessors had thought of doing. He conducted the equivalent of what we would call a double-blind trial. He blindfolded himself and then he had an assistant place or remove the glass plate between the pendulum and a bowl of mercury without his knowledge. Under these conditions, nothing happened. Chevreul concluded,
"So long as I believed the movement possible, it took place;
but after discovering the cause I could not reproduce it."
His experiments with the pendulum show how easy it is "to mistake illusions for realities, whenever we are confronted by phenomena in which the human sense-organs are involved under conditions imperfectly analyzed."
His research on the "magic pendulum", Dowsing rods and table-turning is revolutionary. In his paper "De la baguette"(1864), Chevreul explains how human muscular reactions, totally involuntary and subconscious, are responsible for seemingly magical movements. In the end Chevreul discovered that once a person holding divining rods/magic pendulum became aware of the brain's reaction, the movements stopped and could not be willingly reproduced.
In 1853 Michael Faraday, while studying table tipping, concluded:
that honest, intelligent people can unconsciously engage in muscular activity that is consistent with their expectations
The ideomotor effect is a psychological phenomenon wherein a subject makes motions unconsciously. The term was first used in a scientific paper discussing the means through which the Ouija board produced its results, by William Benjamin Carpenter in 1852, whence the alternative term Carpenter effect. In the paper, Carpenter explained his theory that muscular movement can be independent of conscious desires or emotions.
Carpenter, in 1852, wanted to show that a variety of currently popular phenomena had conventional scientific explanations rather than the widely believed supernatural ones. The phenomena he tackled included dowsing ("water witching"), the magic pendulum, certain aspects of mesmerism, spiritualists' "table turning," and Reichenbach's "Odylic force." [Scientists have abandoned concepts such as Odic force. In western popular culture, the name is used similarly to qi or prana in reference to spiritual energies or vital force associated with living things.]
Pendulum charts: Fantasy masquerading as science?
On August 31st, 1886 Michel Eugene Chevreul celebrated his 100th birthday.
He managed to celebrate two more.
 Finding water underground.
• A 1948 study tested 58 dowsers' ability to detect water. None of them were more reliable than chance.
• A 1979 review examined many controlled studies of dowsing for water, and found that none of them showed better than chance results.
• In a study in Munich 1987–1988, 500 dowsers were initially tested for their "skill" and the experimenters selected the best 43 among them for further tests. Of the 43 pre-selected and extensively tested candidates at least 37 showed no dowsing ability. The results from the remaining 6 were said to be better than chance.
• During a 2004 study in Germany, the three-day test of some 30 dowsers showed results which were no better than chance