The principle to be applied in this case is a familiar one, and the points are well settled by the authorities.
It is apparent that B. P. Paige, the witness, is as competent to testify as his father, Jeremiah Paige, would have been had *471be been living. The witness had an interest in a part of certain land flowed, of which his father was the sole owner. He had likewise an interest in the damages to be recovered in the suit instituted by his father against the defendants. He may, therefore, be considered as occupying a position similar to that of Jonathan Clifford ; and the question then is, whether persons standing in such a relation to the subject matter of the controversy have an interest sufficient to exclude them from testifying.
The decisions, in cases similar to this, seem to settle the point that these witnesses were interested in the question merely, and not in the result of the suit. In Doe vs. Clarke, 3 Bingh. N. C. 429, a witness, who claimed as heir of R, was offered, to defeat the plaintiff, who also claimed as heir of B, and was held competent. In case, for flowing the plaintiff’s land by the defendant’s dam, the owners of mills below, though benefitted by the dam, were held to be competent witnesses for the defendant. China vs. Southwick, 2 Fairf. 341. A person who is connected with the plaintiff in the same transaction out of which the action arose, and who has actually commenced an action against the same defendant for the same injury, is, notwithstanding, a competent witness for the defendant. Bliss vs. Thompson, 4 Mass. 488. In axi action against a certificated conveyancer, for negligence in managing the purchase of an annuity for the plaintiff', a joint purchaser is a competent witness for the plaintiff. Rothery vs. Howard, 2 Stark. Rep. 68. In an action by a mariner against the owner of a vessel, for wages, another seaman, who served on board the same vessel, is a competent witness for the plaintiff, although he may have a common interest with the plaintiff as to the point in controversy. Hoyt vs. Wildfire, 3 Johns. 518. Upon the trial of a complaint against the owner of part of a mill-dam, for flowing land, the owner of another part of the same dam in severalty is a competent witness for the respondent. Clement vs. Durgin, 5 Greenl. 9.
*472These decisions were founded on a principle applicable to the case before us, that the witnesses were interested in the question, and not in the event of the suit. It is argued, however, that Clifford and Paige stand in the same relation to the plaintiff which those persons occupy who are called to prove a customary right, by the existence of which they would be benefited, and that they therefore have an interest in the record as an instrument of evidence.
Now the defence in this case is, that the defendants have a right to flow the plaintiff’s land by means of a pond created by a dam attached to the mill upon an ancient mill site. If they have a right to flow the land of the plaintiff, they have also a right to flow the lands of Clifford and of Paige. These persons are interested that the defendants should not prove the existence of such a right, and their testimony tended to prove that the right did not exist. If they stand in a position analogous to that of a commoner, or of a person who will be benefited by the existence of a customary right, the record will be evidence for or against, them. In such cases a record establishing the custom, is evidence of the existence of the custom in a suit between other parties. Duke of Somerset vs. France, 1 Strange 654. If the issue be on a right of common which depends on a custom pervading the whole manor, the evidence of a commoner is not admissible ; because, as it depends on a custom, the record in that action would be evidence in a subsequent action, brought by that very witness to try the same right. But the same reason does not hold where common is claimed by prescription in right of a particular estate, because it does not follow if A has a prescriptive right of common belonging to his estate, that B, who has another estate in the same manor, must have the same right; neither would the judgment for A be evidence for B. Buller, J., Walton v. Shelley, 1 T. R. 302, 303 ; Lufkin vs. Haskell, 3 Pick. 356; Anscomb vs. Shore, 1 Taunt. 261; Jacobson vs. Fountain, 2 Johns. 170; Gould vs. James, 6 Cowen 369. If a right be common to any *473manor, district, hundred, parish or county, as a local right, it will be holden to be a custom. If it be attached to a particular estate, and be exercised only by those who have the ownership of such estate, it will be a prescription, either personal in its character, or a prescription in a que estate. Perley vs. Langley, 7 N. H. Rep. 235. But no other right is assumed to exist here than that of flowing the land of these persons by means of a dam and pond attached to the mill site. It bears no resemblance to a right of. common, or any customary right belonging to the inhabitants of a particular place, nor are the witnesses commoners, or interested to defeat any customary right. It is a prescription in a que estate, and the interest of those persons whose lands are flowed is an interest in the question only, which does not render them incompetent witnesses.
The argument of the defendants for the rejection of the witness Parker rests on another ground. He conveyed land by deed of warranty, and at the same time told the grantee that the defendants had no right to flow the land. Some damage had then been done by the water to the trees on the premises. It is said that Parker would be liable in case to the plaintiff upon this statement, if the plaintiff should not recover in this suit, and was consequently interested that the verdict should be for the plaintiff.
Upon this point it is not necessary to hold that in no case where land is conveyed with covenants of warranty will an action lie against the grantor, upon an independent representation made at the time of the contract. If a fraudulent statement be made, the party will undoubtedly be liable therefor in an action, although he may have made covenants on the same subject, for the fraud will not be merged in the covenants. If such had been proved in this case, a different question would be presented from that now raised by the evidence. But in this case Parker stated to the plaintiff that the defendants had no right to flow the land. He then made covenants to the same effect, which covenants are released. *474No oral representation, in the absence of fraud, previous to a sale by a contract which is afterwards reduced to writing, is a warranty, for it is merged in the written contract. It would be a very unsafe rule, that a contract should rest partly in writing and partly in parol. The writing is the sole evidence of the agreement; and any verbal statements made at the time are incompetent to add to or to vary it. Mumford vs. McPherson, 1 Johns. 414; Wilson vs. March, 1 Johns. 503; Pickering vs. Dowson, 4 Taunt. 779; Sherwood vs. Marwick, 5 Greenl. 295; Osgood vs. Davis, 18 Maine Rep.
The opinion of the court is that there should be
Judgment on the verdict.