The thread has to do with Va. Gov. Tim Kaine pardoning a woman convicted of being a witch in 1706 (she got jail time, wasn't killed)
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=102x2381793happyyslug posted the following.
Recent research on "dunking" disproved a lot of old wives tales about the practice. For example if you were "received" by the water (i.e. did not float) you were brought up in plenty of time to prevent any drowning.
Second, the nature of the test was prejudice for you being "received by the water", i.e. when rolled into the position in the test you would naturally sink except once in a while someone would take in to much air into their lungs and float. The tyeing up of the person restricted someone's ability to breath thus kept the air in their lungs down so they sank. A case from the Middle ages shows this, a Bishop was accused on some crime and agreed to undergo trial by Dunking. He tested the dunking systems for THREE DAYS BEFORE THE ACTUAL DUNKING. Each time he had been "Received by the Water", he thus was convinced the same would happen on the trail day. On the day of the actual trial, he floated and soon admitted his guilt (It is believe he became nervous on the actual day and took in to much air).
Given Dunking high rate of NOT being a Witch (Estimated at 90%, which is one of the reason its had been rejected at Salem 20 years before) why was it so popular for so long? The best answer it was a way TO SHUT UP ACCUSERS by showing by a "test" that someone was a "Witch" OR whatever Witchcraft she had done God had forgiven her for (Mostly in non-witchcraft cases where Guilt was well know but the guilty had been by "test" found to be non-guilty). Thus such test were a way for the leaders of an town to shut up accusers of "witches" by showing someone was Clearly not a witch. 90% chance of being "Received" can be added by adding whatever iron needed to make the person to be "received".
Thus, in my opinion, Grace Sherwood was dunked to try to show she was NOT a Witch and for some reason Grace Sherwood floated (Style of Clothing may had held water, Grace Sherwood may NOT have been tied tight enough thus permitting her to breath in deeply, or someone forgot to add the horse shoes to make sure she was "received by the water" etc). Anyway Grace Sherwood was "convicted" but no one wanted her to hang for her "offense" thus Grace Sherwood ended up spending some time in jail (In a time period where you had to pay for your jail upkeep but also could make it as comfortable as you wanted it to be, including carpeting, food catered and brought in etc). The fact that Grace Sherwood later received her property back implies no one really considered her a threat to the community (This is the day of forfeiture upon a felony Conviction). About the same time period (1715) Massachusetts had one of the last cases of Petite Treason. A wife conspired to kill her husband and tried for "Petite Treason" for Common law Treason was NOT a felony, but Treason, a separate class of crime. If she had been convicted of Murder (A felony) all of her property would go to the King for one year and then her mease Lord forever. In treason cases a Traitor's property went to the King FOREVER. In Massachusetts, the "Mease Lord", was the Colonial Assembly, while the Governor, appointed by the King was the King. Thus the Governor wanted a Petite Treason conviction for he wanted her assets, a murder conviction would give it to the Assembly instead.
I bring this up for Misdemeanor required imprisonment for LESS than a year and forfeiture of one's property for a year (at the end of the year the property went back to the miscreant). Thus Grace Sherwood's conviction implies it was a Misdemeanor, for Grace Sherwood received her property back, something that did NOT happen in Felonies or Treason cases.
Something was going on politically, I suspect at the township level. Someone with connections were blaming Grace Sherwood and rather then tell that person to shut up, the local politicians tried to shut him or her up with the Dunking Test. When that failed everyone was shocked, Grace Sherwood was NOT suppose to Float, but Grace Sherwood did and thus "Convicted" of witchcraft. Grace Sherwood probably paid off the damages do to the "Witchcraft" and released after making restitution (And thus Grace Sherwood was entailed to her property back upon her sentence). Speculation on my part but that is the law and history of the time period, a period long gone, through it survives in some ways (such as forfeitures) to this day.