A copy of an entry in a banker's book shall not be received in evidence under this Act unless it be first proved that the book was at the time of the making of the entry one of the ordinary books of the bank, and that the entry was made in the usual and ordinary course of business, and that the book is in the custody or control of the bank.

Such proof may be given by a partner or officer of the bank, and may be given orally or by an affidavit sworn before any commissioner or person authorised to take affidavits.