From "Fair Mary of Wallington" at

http://levigilant.com/Bulfinch_Mythology/bulfinch.englishatheist.org/arthur/ballads/Popular-Ballads.htm

"In the Scottish ballad, a ‘scope’ is put in Mary’s mouth when the operation takes place. In the Breton ballad it is a silver spoon or a silver ball. ‘Scope,’ or ‘scobs’ as it appears in Herd, means a gag, and was apparently used to prevent her from crying out. But the silver spoon and ball in the Breton ballad would appear to have been used for Marguerite to bite on in her anguish, just as sailors chewed bullets while being flogged."