The common law recognizes but one description of interest, that shall exclude a person from testifying ; that is an interest in the event of the suit. Merely an interest in the question, as it is called, —his having, or being likely to have, a suit, which may turn upon the same point, is not, in legal estimation, an interest, it Is a bias, affecting his credit, but not his competency. So is the law understood, by the courts at Westminster. Precedents to the contrary, which misled them for a time, as they have the courts in this State, have been found, on examination, to be departures from the law. It was never, indeed, admitted, in principle,... that bias, without interest, went to the competency cf-.-a *271■witness ; nor could it be, without rendering the rule oí admission too uncertain for practice, and too limited for the investigation of truth. The error, that crept into practice, was* that of mistaking, in certain cases, bias for interest.
In this case, the witness offered was neither to gain, nor lose, by the event of the suit. The verdict, which his testimony might have affected, could never have been given in evidence for, or against him. He ought, therefore, to have been sworn, notwithstanding his supposed bias, and his credit left to the jury, with such observations, as the Court might think proper to make, to assist them in estimating it correctly.