If the motion be supported by affidavits and the cause be newly discovered evidence, the affidavits of any witness or witnesses, showing what their testimony will be, shall be produced or good reasons shown for their nonproduction.
[ 1891 c 59 § 2; Code 1881 § 282; 1877 p 57 § 286; 1869 p 68 § 284; 1854 p 170 § 219; RRS § 403.]