The pasilalinic-sympathetic compass, or “snail telegraph,” was an attempt to harness telepathic snails for long-distance communication. First tested in 1851 by a French occultist named Jacques Toussaint Benoit, the idea was later revived by the eccentric socialist Jules Allix during the Siege of Paris, when the city was desperate for outside communication channels.

http://www.cs.man.ac.uk/~toby/writing/Skeptic/pd26.html

http://en.wikipedia.org/wiki/Snail_telegraph