Morehead's Magnetic Plaster

Morehead's Magnetic Plaster was a body plaster that was produced by D.C. Morehead as a pain relief remedy in mid-to-late 19th century, promoted as affecting healing magnetism.

Composition
Oleson's "Secret nostrums and systems of medicine" (1890) reports the formula as being "tar and extract of belladonna, each in equal parts", though the claim is prefaced as being hearsay.