The county of Madison is bounded as follows: Commencing at the southeast corner of township twenty-one, north, of range one, west; thence north to the northeast corner of township twenty-four, north, of range one, west; thence west to the northwest corner of township twenty-four, north, of range four, west; thence south to the southwest corner of township twenty-one, north, of range four, west; thence east to the place of beginning.