Alexander Dyce, A General Glossary to Shakespeare's Works

evil — “The,” MACBETH, iv. 3. 146. Perhaps it is unnecessary to notice that this means the scrofulous disease known by the name of the King's Evil, because the sovereigns of England were supposed to possess the power of curing it “without other medicine, save only by handling and prayer” (as Laneham says, quoted here by Reed); and probably many readers will recollect that Dr. Johnson, when a child, was carried by his mother to London to be“touched” by Queen Anne.