delivered the opinion of the court. This is an action by the curator of a vacant estate, against the purchaser of property at a probate sale of the effects of the succession and his surety. The principal pleaded novation of the debt, and the surety a declinatory exception. The exception was sustained, and on the trial the principal offered the surety to prove, there had been a nova*266tion of the debt. He was objected to, and rejected by the court. Before us, it has been contended he was competent; because the novation, which he offered to establish, was that by which he made himself responsible as principal debtor.

Although the witness could not be said to have an interest in shewing he was principal debtor, and not surety, still we are of opinion, he was incompetent to testify in this case. For, if it were true, that he engaged to pay the debt of the principal, then it follows, that he was interested to defeat this action; because the principal, if condemned, would have a right to call on the witness for the debt, and the costs incurred by the failure of the latter to discharge the obligation.

The evidence in the cause, independent of the surety’s testimony, (which was put in the record to be used here, if this court should consider him competent,) does not establish a novation.

It is therefore ordered, adjudged and decreed, that the judgment of the district court be affirmed with costs.