and provided, for other Justices of the Peace in this ; the Mayor shall have plenary power and original jurisdiction in all cases arising under the laws and ordinances of the corporation, and to issue such process as may be necessary to carry into execution or effect such laws and ordinances; Provided, that an appeal may be had from any decision, or judgment, of said Mayor or Aldermen, to the Municipal Court, which court shall be composed of the Mayor, as Chief-Justice, and the Aldermen, as Associate-Justices, and from the final decision, and judgment, of the Municipal Court, to the Circuit Court, in the same manner as that of a Justice of the Peace in like cases: Provided, also, that the parties litigant shall have a right to a trial by a Jury of twelve men, in all cases, before the Municipal Court.