Every peddler or itinerant trader, by sample or otherwise, shall apply for a license to the judge of the probate court of each county where he may desire to trade, which license shall be granted to him on the terms the judge of the probate court may impose. The judges of the probate courts are authorized to impose such license fee as they may deem advisable, which fee shall be used for county purposes. The license shall extend only to the limits of the county.