All subpoenas for witnesses from said court shall be returned by the Sheriff within six days after the same are issued by the clerk, or within six days after the day of the renewal of such subpoenas, unless the same are ordered to be returned immediately, in which case they shall be so returned, if practicable. P.L.L., 1860, §186 1888, §191 1915, §335 1927, §335 1930, §335 1938, §433 1949, §266 1969, §22-45 1898, ch. 123, §335