In 1850 Jacques-Toussaint Benoît claimed to be able to send messages via telepathically linked snails. He could not.
I don’t have a lot of time for scams in general, but I have to admit that this particular example from 1850 Paris is impressive in its audacity. The minor occultist Jacques-Toussaint Benoît had been sponging free room and board while he worked on a plan to invent instant communication across the globe. It involved telepathic snails.
When his benefactor got impatient, Benoît actually put together a prototype and invited journalists to bear witness. Here’s the basic concept: when snails had sex they developed a psychic link – which Benoît imagined as something like an invisible attenuated fluid strand spooling out from one snail to the other – and that link acted as a kind of telegraph cable, allowing instant communication between the two.
This important discovery out of the way, all that Benoît had to do was find a way to exploit it. He paired up 48 snails in 24 separate couplings, divided the partners up into two matching sets, and glued them all on a wooden board next to alphabet symbols. (Why not 26 snails? In French, the letters W and K are typically only used for words loaned from other languages, so I assume that he skipped those two.) Supposedly, if you pressed one snail on a board then the corresponding snail on the other board would stick its tentacles out sympathetically. So on one board you have people carefully pushing on snails, and on the other people keeping an eye out for any tentacular movement that would indicate which letter had been pushed.
The demonstration did not go well. Benoît bounced back and forth between the two boards a lot to “make sure they were doing it right,” and the message still ended up as a garbled and misspelled mess. The inventor claimed that he had a compatriot in the States with whom he frequently communicated, and promised a proper demonstration to follow. Instead he skipped out on everyone and was not heard from again.