Where, in the exercise of the police power, a license is issued, the license is not a contract but only a permission to enjoy the privilege for the time specified, on the terms stated; and it may be abrogated. (Civil Code 1895, § 15; Civil Code 1910, § 15; Code 1933, § 20-117.) History of Code section. — This Code section is derived from the decisions in Brown v. State, 82 Ga. 224, 7 S.E. 915 (1888), and Sprayberry v. City of Atlanta, 87 Ga. 120, 13 S.E. 197 (1891).