Colorado Revised Statutes Title 13. Courts and Court Procedure § 13-25-113. Lost deed--bond--note--affidavit

When, in the progress of any suit in any court in this state, either party thereto relies for its maintenance or defense, in whole or in part, on any deed, bond, note, draft, bill of exchange, letter, or any other writing alleged to have been executed, signed, or written by the adverse party, and to have been lost or destroyed, the party so relying on the same as evidence in his behalf in the trial of the cause shall not be permitted to give evidence of the contents thereof by a competent witness until said party or his agent or attorney first makes an oath to the loss or destruction thereof, and to the substance of the same.