The only question raised in the present case relates to the competency of William C. Leonard, as a witness, in behalf of the tenant.

Leonard was the grantor of the premises in controversy, and conveyed the same to the tenant by a deed containing the covenant of warranty. ‘ Such a covenant, of course, makes the witness directly interested in the event of the suit, unless the interest has been in some way removed. This the tenant insists has been done by his giving Leonard a release from all the covenants contained in his deed to the tenant, which release has been duly acknowledged and recorded in the registry of deeds ; and it is said, that such release, with the further fact that the tenant has never made any conveyance of the land, or any part thereof, presents a case of a valid and effectual release to Leonard from all future liability, upon his covenant of warranty.

It seems that every thing has been done that could be done to discharge the witness from his liability, upon the covenant; and if such release does not render the witness competent, it is for the reason, that his interest is such a legal interest as cannot be reached by a release. And it is supposed by the demandant to be of that character, by reason of its being a covenant running with the land, and passing to each successive grantee of the estate.

No question can arise as to the nature of this covenant. *507nor any doubt exist as to its being one of that class of covenants that run with the land, which may be enforced by an assignee in his own name. But all this may be true, and yet the inquiry returns, whether this covenant cannot be discharged by the party to whom it was made, while he holds in his own right the entire interest conveyed, and in the same state in which it was when conveyed. As such grantee, the party to whom the covenant was made might release to his warrantor all the estate conveyed, and thus discharge the covenant of warranty. He might convey any portion of the land, or create a lien or charge upon it, or burden it with a servitude by way of easement; and having the entire estate liable thus to be incumbered by him, and being the lawful owner of all the covenants connected with the grant to him, it would seem to follow, that he might by a proper instrument, duly executed and recorded, effectually release any covenants in the deed from his grantor.

The objection, however, is, as before stated, that the covenant of warranty is a covenant running with the land, which passes to each subsequent grantee, in whom the right vests accordingly t.o enforce such covenant against the warrantor. This is doubtless true, when the land is conveyed to q third person; such covenant remaining in full force and no event having interposed to defeat or discharge it, or to release the warrantor from any future liability thereon. But, certainly, such covenant does not always pass to each subsequent grantee. Suppose the case of an eviction of the first grantee by a paramount title, and a payment thereupon by the warrantor of damages to his grantee, to the full amount of the damages caused by his warranty : I take it as conceded, that this payment would discharge the liability of the warrantor. And yet the grantee may afterwards, in form, convey the premises to some third person ; but such grantee would not succeed to any right to enforce the covenant of warranty made by the original grantor; and this not because the covenant of warranty is not a covenant running with the land, but for the reason, that in the particular case supposed the covenant was discharged while in the hands of the first *508grantee, and therefore could not pass to his assignee. All that the second grantee takes is the right to all covenants running with the land, that have not been legally discharged, or become mere choses in action, in the name and right of some previous grantee.

But it ’s urged that there has been no legal discharge of this covenant of warranty in the present ease. It is difficult to perceive how more could have been done to give effect to this discharge of the covenant. The release is in apt words, duly executed by the party, and acknowledged and placed upon the records of the registry of deeds, with appropriate references from the same to the original deed. It is, however, insisted, that the registry of this release is of no effect, as it is not an instrument which is properly the subject of record in the books of the register of deeds. This presents a point of more difficulty. Treating the release as a mere release of an ordinary kind, or writing obligatory, it would not be a proper subject for record in the registry of deeds. But as a release of a covenant running with land, and attached to a deed already the subject of record, there are peculiar reasons why such' a release might be held to be so closely connected with the conveyance of real estate, as to become a proper subject for record in the registry of deeds. If the release materially affects the title and interest in real estate, or any incidents therewith connected, then such instrument, thus qualifying or releasing an interest in the estate or in any covenants connected therewith, that might be the subject of sale and transfer, as incident to a conveyance of the land, would, by being duly recorded, give as effectual notice to a subsequent purchaser, as a release or quitclaim of some portion of the land, or of some undivided interest in the estate, or a grant of an easement in the same, of all which latter instruments the record would be effectual notice to a subsequent purchaser. These considerations will have their proper weight, whenever a case arises upon such covenant of warranty, by an action instituted in favor of a ourchaser, taking a conveyance after his grantor has executed such release, and after the release is recorded. It *509will in such case become necessary to decide the question, whether such release duly executed and recorded in the registry of deeds will effectually discharge the grantor from the covenant of warranty, as respects an assignee of the land taking the same subsequently. The present case does not require us to express any opinion upon that question.

The objection to the competency of Leonard as a witness is taken by the demandant. It assumes, as the ground of objection, that Leonard has a pecuniary interest in procuring a verdict in favor of Snell, the tenant. The sole inquiry then is, has Leonard any such interest ? Will he in any way be benefited by a verdict in favor of the tenant ? Now, it is quite obvious that upon the facts before us, Leonard had no such interest, but on the contrary, would be more effectually secured from all possibility of pecuniary responsibility by a verdict in favor of the demandant; Leonard holding this release from the tenant, a judgment in favor of Field, the demandant, would render the release entirely effectual to the witness. Suppose a recovery in the present action by Field, the effect of such recovery would be, that Field would acquire the title and the possession of the demanded premises by a judgment of this court, being the highest evidence of title. Such recovery and judgment in favor of Field ousts Snell, and thereby the course of warranty by Leonard to Snell is at once broken. The breach of this covenant has taken place, while Snell held the covenant, and he alone can recover damages for such breach. But all claim for such damages has been released by his release of the covenant to Leonard; and thus in the case supposed Leonard has the full benefit of his release. Indeed, it renders it wholly effectual. The covenant of warranty attached to Leonard’s deed to Snell, after such breach, would not run with the land so as to pass to any subsequent grantee of the same. Nor could Snell, in such case, make any subsequent valid conveyance of the premises, if the verdict and judgment were in favor of Field. He would be disseized, and so could make no conveyance of the land, or transfer the covenant of warrant) or other covenants running with the land.

*510It is quite obvious, therefore, that the witness, holding a release from Snell, discharging him from all liability upon his covenant in the deed to Snell, had no interest in obtaining a verdict in favor of Snell; for a recovery by Field would make his release from Snell entirely effectual in discharge of all future liability on his warranty, whatever might have been the rule of law, as to the general effect of a release of this covenant by. a party holding a deed with covenant of warranty. Upon this ground, it is quite clear, that the witness was not interested adversely to the demandant, and the exception taken to his competency is untenable. As authorities sustaining these views, see Cunningham v. Knight, 1 Barb. 399, 405; Clark v. Johnson, 5 Day, 373; Ford v. Wadsworth, 19 Wend. 334. Judgment on the verdict.