insane “root—The,” MACBETH, i. 3. 84. The root which causes insanity. Perhaps hemlock; or more probably henbane, as would appear from the following passage, cited by Douce: “Henbane . . . is called Insana, mad, for the use thereof is perillous; for if it be eate or dronke, it breedeth madnesse, or slow lykenesse of sleepe. Therefore this hearb is called commonly Mirilidium, for it taketh away wit and reason.” Batman Uppon Bartholome de propriet. rerum, lib. xvii. ch. 87.