delivered the opinion of the court.

The contract in writing, of October 11, 1902, signed by J. H. Todd, made between P. M. Gross and himself, was the sole expository of its own terms, and the parol evidence offered to show that Gross was to teach Todd a trade was erroneously admitted, since it altered the terms of that contract. Todd admitted, on the witness stand, that his defense was precisely the same against each of the three notes; that there was no difference-whatever, in any respect, between his defense to the first note of $50 and the two other notes for $100 each. The jury had measured the full value of his defense in the suit on the $50 note, and fixed that value at $45, rendering a judgment for the plaintiff in that suit for $5 only. On this state of case Davis v. Hart, 66 Miss. 642, 6 South. 318, settles the proposition that the first judgment for $5 on the $50 note was res judicata as to-the valué of the defense in its entirety, and that defense, consisting simply of failure of consideration, should not have been-allowed to be interposed in either of the other two suits, since the jury had measured how much the consideration had failed in the first suit, and fixed the amount of such failure at $45.

Reversed and remanded.