If any person, appointed or elected as an officer or employee of the city, shall undertake any venture, or make any contract, for his own benefit, under such authority, or be in any manner concerned or interested in making such contracts, or in the profits thereof, either privately or openly, singly or jointly with another, he shall be guilty of a misdemeanor; provided, such undertaking or contracting may be authorized by the City Council.
('70 Code, § 2-18)