Had the vendee unconditionally accepted the conveyance containing, as it did, a covenant of general warranty, he would have elected to rely on it exclusively, and could not have used this known and contingent defect, whether real or supposed, as a pretext to withhold the purchase-money. Did the special covenant which he exacted, give him a particular right to do so? The vendor, Gray, bound himself “to obtain, deliver up, or cancel, said agreement with Doctor Bailsman, as soon as practicable;” and the vendee bound himself, “ upon the performance of this condition by the said Gray, to make and deliver him his certain promissory note for 2500 dollars, dated May 15, 1835, and payable eighteen months after date;” from which it is attemptéd to be inferred, that the parol contract of sale was merged in the covenant; that is to say, that the vendor consented, in the event that the paper should turn out to have been previously destroyed or lost, to forfeit his land and the price of it together. If that pretension be disclaimed, then it must be conceded that the construction insisted on, is an' unsound one; for it would produce just that effect. On the covenant he could never have an action at all, for the performance of his own covenant, since found to be.impracticable, would be a condition precedent to it; and thus his inability to produce a defeasible agreement, subsequently annulled and reduced to the value of waste paper, would have the effect of depriving him of his estate. Even were such a consequence inevitable at law, equity would not suffer it to be enforced; for there is a numerous class of cases in which contracts, based on a supposed state of things which had no existence in fact, have been relieved against, on the ground of mistake. But there was no such merger. The covenant was a special one operating, hot on the contract-of purchase, but on a thing collateral to it—the terms of the security to be given for the purchase-money—■ and if the vendor think proper to waive the benefit of the security, why may he not do so without being held to performance of his covenant, as a condition precedent to an action not founded on the instrument? If the vendee think himself prejudiced by want of such performance, let him bring an action on it; but let him not detain the whole purchase-money for what would be a ground to recover, at most, but nominal damages. The judge, therefore, was right in directing that the plaintiff might recover on the evidence, and under the present form of action.

Judgment affirmed.