Editing Dowsing (section)

===Postulated mechanisms===
Early attempts at an explanation of dowsing were based on the notion that the divining rod was physically affected by emanations from substances of interest. The following explanation is from [[William Pryce]]'s 1778 ''Mineralogia Cornubiensis'':

{{Blockquote|The corpuscles... that rise from the Minerals, entering the rod, determine it to bow down, in order to render it parallel to the vertical lines which the effluvia describe in their rise. In effect the Mineral particles seem to be emitted from the earth; now the Virgula [rod], being of a light porous wood, gives an easy passage to these particles, which are also very fine and subtle; the effluvia then driven forwards by those that follow them, and pressed at the same time by the atmosphere incumbent on them, are forced to enter the little interstices between the fibres of the wood, and by that effort they oblige it to incline, or dip down perpendicularly, to become parallel with the little columns which those vapours form in their rise.}}

A study towards the end of the 19th century concluded that the phenomenon was attributed to [[cryptesthesia]], where the practitioner makes unconscious observations of the terrain and involuntarily influences the movement of the rod.<ref name="ByO0k">{{cite journal|last1=Pass|first1=A.C.|last2=Tawney|first2=Edward. B.|title=The divining rod|journal=Proceedings|date=1876|volume=I|pages=60 et seq|publisher=[[Bristol Naturalists' Society]]}}</ref> Early investigations by members of the [[Society for Psychical Research]] endorsed this view.<ref name="inglis254">Inglis (1986), pp.254-5.</ref>

Committed [[Parapsychology|parapsychologist]] [[G. N. M. Tyrrell]] also believed that the action of the rod was caused by involuntary muscular movements and debunked the theory of external influences.<ref>Tyrrell, G. N. M. (1938). ''Science and Psychical Phenomena'', Methuen, London.</ref>

Dowsing over maps, prior to visiting the site, was also believed to work, hence some kind of [[clairvoyance]] was proposed. This was believed to act on the [[nervous system]], rather than on the muscles directly. These various mechanisms remain in contention among dowsers.<ref name="inglis254"/>