Thu Court,

held that it was the intention of Congress to permit the court in cases falling within the proviso, to exercise its discretion against receiving the testimony of the surviving party where *39the transaction would probably be denied by the deceased party if he were alive, and there are no extraneous circumstances throwing light on the subject.

But when the court can see that the transaction as stated by the surviving party is probable, and there are corroborating circumstances tending to support his version; in short, when it can see that justice demands that the surviving party should be sworn, the discretion of the court should be exercised so as to permit his testimony to be given.