Walker v. Cuthbert and Stanley, at this term, was an action for the recovery of the “further sum of five hundred dollars,” agreed to be paid by the writing which was adduced at the' trial, and we there say that the agreement required the aid of extrinsic proof to ascertain what facts existed when the agreement was made and without the aid of these facts, it is impossible to say, whether the services were to be, or had been rendered. “It is entirely evident, if an agreement of this sort is made with respect to a suit just commenced, the construction would be that the pro-misees should prosecute it to some final result; but when made with regard to a suit just determined, we think the only proper construction is. that the promise and agreement refers exclusively to services already rendered.” Further, the intention of the parties to be collected from the agreement is, that the plaintiffs shall be paid whenever the promisors receive the fund or property covered by the suit in which the services were rendered.” Again, “The agreement of the parties being rendered definite and certain by ascertaining that ‘professional services in said cause,’ were services already rendered, it is entirely clear the parties contemplated nothing more; as the condition on which the money was to be paid; and in this view the refual of the plaintiffs to attend to the case in the supreme court could not affect their right to recover the entire sum stipulated.”
The construction of the writing, and the conclusion deduced from it, in the case cited, we think furnish a guide for us in the case at bar. In respect to the first point, the circuit court properly refused to reject the evidence of the conversation which the defendant’s agent had with the plaintiffs, at the time they were retained as counsel. What was then said, tended to show what professional services were to be rendered by the plaintiffs as a consideration for the fee stipu*166lated. It is clearly competent to prove the consideration of a promissory note, by parol testimony, that it may be seen that it has failed, or is unsupported by any which the law recognizes as sufficient.
But the ruling of the court upon the second point cannot be sustained. When the objection was then made to exclude the evidence of a verbal agreement, the writing subsequently executed had been adduced; this was an agreement containing the last expression of the understanding of the parties, and merged all prior stipulations in regard to the subject matter. Not only “ the further sum of five hundred dollars.” but the note also, must be held to refer to the “ professional services in said cause,” for its consideration; although its payment is not to be postponed, until the money adjudged to. be paid in the case of Minter et al. v. Bowie shall have been collected. This is clearly indicated by the reference to, and adoption of the note by the writing.
What we have said is but a necessary sequence from the case cited, and the charge of the court in giving effect to the verbal agreement, as if the writing had never been executed, is a clear error. The judgment is therefore reversed, and the cause remanded.