The board of county commissioners of each county of the state, when the interests of the county require it, may employ an attorney, but the person appointed shall be a member of the bar of the supreme court of this state and at least twenty-five years of age. The board may also, when the business of the county requires it, appoint a county collector, whose duty it is to collect license moneys and other special dues of said county; such collector shall receive such compensation as may be allowed by the board of county commissioners.