Here's what I found......
FAQ: Witch Pieces
There is an old superstition that a bent coin afforded protection against witches. The idea of a bent coin is in an old Mother Goose rhyme about a Crooked man who had a crooked six pence.
It has been noticed that many Oak and Pine tree shillings were wavy and it was assumed they had been bent to protect against witches and later had been straightened out thus leaving a wavy appearance. It has recently been discovered (see the Oak Tree introduction at:
http://www.coins.nd.edu/ColCoin/Col....intro.html) that the reason for the bending is that the coins were made on a roller press. The blank coin planchet was put between two rollers that impressed the image on the coin (kind of like early washer machines would squeeze water out of clothes by putting the wet clothes through two rollers). When the coin came out of the two rollers they were not perfectly straight but rather slightly bent. So the bending is due to the coining process not because of the old superstition. It should be remembered the Witch hysteria was not until the 1690's (twenty years after the coin minting ceased) and most people now think this superstition had nothing to do with the wavy appearance of the coins.
As to tooth marks, some people did in fact bite a coin to test if it was real silver or a counterfeit. Counterfeits would often be made of lead and so were softer. A deep tooth impression would let one know the coin was counterfeit. However this was a rare event but some examples with teeth marks do exist.
Edited by Mike
10/20/2005 10:38 pm