Any person who, by himself or his servant or agent, sells any methylated spirits or surgical spirit in contravention of the provisions of this Act, or who, being disqualified from having his name entered in any local authority's list kept in pursuance of this Act, applies to have his name entered in any such list, or who obstructs any police officer in the exercise of any power conferred on him by section four of this Act, shall be guilty of an offence and liable on summary conviction to a fine not exceeding ten pounds or to imprisonment for a period not exceeding sixty days.