During the times when Puritans believed there were witches among them, tests such as the swimming test were given, according to History.com. Another test dealt with the idea that witches were unable to speak the holy scripture aloud. Looking for witch's marks was also common.
Swimming a witch involved tying up the accused and dropping her into the nearest and deepest body of water; if she floated, she was allegedly a witch. If she sank, she was innocent. Despite the ropes that were tied around the accused witches to pull them from the water if they did not float, some still drowned during the test.
It was said that those afflicted with witchcraft were unable to say religious scriptures, verses, psalms or even the Lord's name aloud, particularly without making mistakes. Many assumed any mistake was a sign of witchcraft, not taking into account the nerves of the accused or the possibility that the accused was illiterate.
Witch's marks were supposed to have been put on the accused person's body when she made a pact with the Devil. To test for this, the accused was stripped and publicly examined for the purpose of finding the Devil's mark or witch's teat, as they were called, despite the fact that they were often just blemishes, scars, birthmarks or sores. These marks were believed to be numb and did not produce pain.