In cases of perjury, where the perjury is charged to have been committed in a court, it shall be sufficient to show that the oath was administered by any officer of the court authorized so to do, or that the defendant testified and gave his testimony as under oath, or if the question be in doubt as to what particular officer administered the oath, it may be shown that it was administered by any officer authorized so to do.
R.L.1910, § 5909.