law: 74. Enhanced penalty after previous conviction.-
  If any person who has been convicted for an offence punishable under any of the foregoing provisions (other than sections 72B and 72C) is again convicted for an offence committed within two years of the previous conviction and involving a contravention of the same provision, he shall be punishable for each subsequent conviction with double the punishment to which he would have been liable for the first contravention of such provision.]