Second, under the statutory framework applicable to Papo, his sentences were not governed by a single subsection. Section 841(a) makes it illegal to possess “a controlled substance.” Section 841(b)(1)(A) specifies the maximum sentence to be imposed “[i]n the case of a controlled substance in Schedule I or II which is a narcotic drug.” Section 812(c) lists the proscribed narcotics separately in various schedules and subsections. Heroin is listed in Schedule I(b)(10), and cocaine is listed in Schedule 11(a)(4). Subsections 841(a), (b)(1)(A), which incorporate by reference the list of controlled substances in Section 812, are the equivalent of an enumeration in separate subsections of each substance listed in Section 812. Cf. United States v. Pope, 561 F.2d 663, 669 (6th Cir.1977) (<HOLDING>). Finally, the congressional intent to impose
holding that possession of listed chemical with intent to manufacture controlled substance is controlled substance offense holding that simultaneous possession of heroin a schedule i controlled substance and methadone a schedule ii substance are separate offenses under 21 usc  841a1 holding that quantity of the controlled substance does not have to be measurable to support a conviction for possession of such controlled substance particularly when the immeasurable amount of the substance is found on an implement used to consume the substance holding that possession of a controlled substance is a crime only if the defendant knowingly possesses the substance and has knowledge of the nature of that substance holding that mens rea required for possession of a controlled substance is knowledge that defendant possessed a controlled substance