Search for the Devil's or witch's marks formed an important part of the examination of suspected witches in the 17th century. These skin marks were insensitive to piercing by a needle and did not bleed. Ideas about them varied between countries. In England and America, the mark was regarded as an extra nipple where the witch's familiar suckled1, similar to the concept that vampires gain control of their victims' souls by sucking their blood. In Scotland, the mark signified a covenant between the witch and the Devil. Bell2 wrote, 'Tis but rational to think that the devil, aping God, should imprint a sacrament of his covenant . . .'. The beliefs of Scottish legal authorities were influenced by Disquisitionum Magicarum by Martin del Rio, a Jesuit priest. New witches were believed to be given the marks by the Devil either individually or at a sabbat.

Devil's marks are described by several educated Scotsmen of the period-Reverend John Bell, minister of Gladsmuir Reverend Robert Kirk, minister of Aberfoyle and two eminent lawyers, Sir John Lauder of Fountainhall and Sir George Mackenzie.