Pinney, J.
The contention of the plaintiff that the evidence to sustain the defense was not admissible is, we think, founded upon a misapprehension of the nature of the transaction and the purpose for which the evidence was introduced. After the execution and delivery of the deed the plaintiff retained the entire consideration and held it upon the trust and agreement that he would apply it to the payment of existing incumbrances on the land, which the defendant was bound by his covenant to pay, and in the payment of which the plaintiff had a special interest. He assumed and undertook to do with the defendant’s money what the defendant was himself in duty bound to do. The *17plaintiff was not bound to take upon himself this trust or duty, but having undertaken it and entered upon its performance it was his doty, without other consideration, to use ordinary care and vigilance in that behalf, and for a failure to do so he would be liable for the damage ensuing. Jones v. Parish, 1 Pin. 494 He took credit in the subsequent settlement with the defendant for having paid off the incumbrance, when he had not in fact paid it, and he seeks by this action to charge the defendant with the consequences of his own misrepresentation and subsequent negligence. To allow him to do so would be to permit him to take advantage of his own wrongful conduct, and would operate as a surprise and fraud upon the defendant. According to the effect of the finding of the court, the plaintiff still holds the defendant’s money to the amount of the incumbrance complained of as a breach of the covenant in question, and he now contends that this incumbrance was not in fact paid off as he represented when he settled with the defendant and obtained credit for the amount upon the faith of his representation of payment. The defendant, relying upon the truth of this representation., gave the matter no further attention until it was too late to redeem the prem-' ises. The plaintiff cannot be allowed now to change his position. In getting in the title on the sheriff’s sale he has simply performed a duty he owed to the defendant. In equity, as between these parties, this incumbrance must be treated as having been paid, and the plaintiff is now estopped to claim to the contrary. This is the result of the plainest principles. The evidence in question did not contradict, vary, or change the effect of the deed or covenant. It did not show or tend to show that the incumbrance was not to be paid off by the defendant, but that it was to be paid out of his own money in the plaintiff’s hands for that purpose, and that, in consequence of the plaintiff’s representations *18that he had paid it and taking credit therefor in the settlement, and the defendant’s reliance thereon until after the time for redemption had expired, he is estopped from asserting that the title founded on the sheriff’s deed which he has bought in is a breach of the defendant’s covenants in his deed. In buying in this title to protect himself in the possession of the .farm, as to the defendant, he was at a late day performing the duty he had long owed to him. Manifestly, he cannot found a cause of action upon this fact. Besides, the evidence showed in what manner the consideration named in the deed was to be paid, and parol evidence was clearly competent for that purpose. Schillinger v. McCann, 6 Me. 364; Burbank v. Gould, 15 Me. 118; Dearborn v. Parks, 5 Me. 81, 17 Am. Dec. 206, and cases there cited; Altringer v. Capeheart, 68 Mo. 441; Drury v. Tremont Imp. Co. 13 Allen, 171; Hahn v. Doolittle, 18 Wis. 196.
The defendant’s covenant against incumbrances was broken by the existence of the incumbrances as soon as made, and turned in respect to them into mere rights of action. It was competent, not only for the parties to agree in what particular manner this covenant should be extinguished, but how and in what manner the cause of action which had incidentally accrued on it should be discharged. The case in this respect is in principle the same as Jones v. Keyes, 16 Wis. 562, where the defendant gave the plaintiff his note for the price of certain letter boxes, drawers, and post-office furniture, with a parol agreement that each should receive his proportionate share of the rent of the boxes, etc.-, during the quarter when the defendant took possession of the office, and that his share, when ascertained and received, should be indorsed on the note, and it was held competent to show by parol- such contemporaneous agreement as to the manner in which the note was to be *19paid. The evidence admitted in this case was clearly competent for similar reasons, and it showed the plaintiff had no right of action, as the circuit court rightly held.
By the Gourt.— The judgment of the circuit court is affirmed.