In this point of view the term has a most extensive signification, including narcotics, anaesthetics, antispasmodics, blood-letting, Quinine, Arsenic, and other remedies of a greatly diversified character; in fact, it applies to all medicines which relieve pain, from whatever cause it may arise. The term, however, is generally restricted to those medicines which act upon the brain and nervous system, producing torpor and sleep. Those most commonly employed internally are, Opium, Belladonna, Conium, and Henbane, to which may be added Hydrocyanic Acid. Many substances externally applied are unequivocally anodyne; e.g., hot water, either pure, or containing Poppy capsules. Ice, externally applied, also relieves pain, and is, consequently speaking, an anodyne. The diseases in which anodynes are indicated are all those characterised by the presence of pain. The term has too general an application for practical purposes.