Charm for the Cramp.
Reading edition
Coleridge tells us of a couplet that it was common to repeat in his boyhood, to relieve the foot when asleep, or to cure the cramp in the leg. The sufferer pressed the sole of the foot hard on the floor, and said—
"The devil is tying a knot in my leg! Mark, Luke and John, unloose it, I beg!"