2870. A statement made by a person who does not appear as a witness, concerning facts to which he could legally testify, is admissible as testimony on application and after notice is given to the adverse party, provided the court authorizes it.
The court shall, however, ascertain that it is impossible for the declarant to appear as a witness, or that it is unreasonable to require him to do so, and that the reliability of the statement is sufficiently guaranteed by the circumstances in which it is made.
The reliability of documents drawn up in the ordinary course of business of an enterprise, of documents entered in a register kept as required by law and of spontaneous and contemporaneous statements concerning the occurrence of facts is, in particular, presumed to be sufficiently guaranteed.