Definition of narcotic expanded to include coca derivatives, coca leaf, opium derivatives and Indian hemp under excise law. Amendment broadens terminology by substituting 'narcotic drug or narcotic' for earlier phrasing and inserts detailed definitions for coca derivative (crude cocaine, ecgonine, cocaine and salts/derivatives), coca leaf (specified species and mixtures), derivative of opium (medicinal opium, prepared opium, morphine and salts/derivatives), and an expanded definition of Indian hemp; it confirms that 'narcotic drug' includes these categories and may be extended by Central Government notification, and directs amendment of the Act's Schedule as set out in the Sixth Schedule.