GOLDTHWAITE, J.
— 1. The first question arising from ■the exceptions taken at the trial, relates to the letters and entries *69shown to be written by the defendant. A, detailed examination of these is not necessary, because we consider all of them, to be prima facie admissible, from the conceded fact, that each was written by the defendant. If any portion-of this evidence was liable to exception, the attention, of the Circuit Court ought to have been called to the precise point which made its exclusion proper, because the adverse party might, in that event, have obviated the exception by other evidence, or could have withdrawn that which was illegal or irrelevant. A contrary course is more important to mislead an adversary, than to advance the ends of justice, and can receive no sanction from this Court. The point to be established before the jury was the defendants connexion as a partner with the firm of Lewis & Barry. The entries made in their books, as well as létters written in their names by him, tended directly to prove the issue. There is therefore no error in this particular.
2. The next exception is for excluding the letter, written by the witness, who admitted, on cross examination, that this letter contained a different representation of facts than that which he then deposed to. This letter the defendant wished to read to the jury, but the Circuit Court would not allow it to be read, because the witness stated its contents to the jury. The rule is, that the adverse party will not be permitted to impeach the credit of a witness, by showing that he has made other statements of the facts given in evidence by him, unless, the enquiry is first made of him whether he has made such statements. [The Queens case, 2 B. & B. 300 ; 3 Starkie on Ev. 1753.] The reasonableness of this rule is made obvious; a very improper impression of the credit due to a witness might be received, when it appeared that he had on different occasions given different versions of the same facts; and yet, the witness might be entirely credible and wholly free from blame, if allowed to explain the circumstances under which the different statements were made, or which caused them. It is, therefore, not permitted to impeach a witness for this cause, unless the opportunity is accorded to him, of giving his own explanation of the variant statements. Beyond this, however, the rule docs not extend ; it will not ex-*70elude the evidence of the variant statements, because the explanation is satisfactory to the Court, or because the variance is admitted in the same manner that it might be proved. These are circumstances to be weighed and determined by the jury, and it is impossible for them to determine whether the contents of a letter had been fully stated without having the letter in evidence before them. A Court might consider the witness as having admitted the same variant statement as contained in the letter ; the party might think otherwise. It is because the jury are the only proper judges of the effect and weight of these matters, that the letter should have been read. The letter might not, and probably would not, have influenced the decision of the jury, but it should have been admitted, and the reason given for its rejection cannot be sustained.
An exception, seems, from the bill of exceptions, to have been taken to the introduction of a letter to Lawrence, Keese & Co. of New York, but it either has not been sent up with the transcript, or its distinctive mark has been omitted. An examination of it cannot, therefore, be made.
3. The question arising out of the admission of the partner, Barry, as a witness is one of much intrinsic difficulty. On no subject are the decisions more numerous or variant than of the interest which will disqualify a witness ; to state the cases would be laborious, and to review them within the limits of an opinion, entirely impracticable. It may be remarked that there are decisions of the English Courts directly on this question, and which hold that a partner is a competent witness, if not a party to the suit, (Lockhard vs. Graham, 1 Strange 35; York vs. Blott., 5 M. & S. 71; Blockett vs. Weir, 3 B. & C. 385; Hall vs. Curzin et al., 9 B. & C. 646.) The reasons on which the competency of a partner is supposed to rest, are thus stated by Chief Justice Abbot, in the case of Blockett vs. Weir. “ It is the interest of the witness to defeat the plaintiff, for in the event of his recovery, the defendant would be entitled to contribution from the witness. In cases of trespass, witnesses, apparently open to a much stronger objection, are constantly admitted. In that action a recovery, against one of several co-trespassers, is a *71bar to an action against the others; and yet scarcely a circuit passes without an instance of a person who has committed a trespass, being called on to prove that he did it by the command of the defendant. In that case a verdict would operate as a discharge of the witness, there being no contribution in actions of tort ; here, on the contrary it brought a liability on him.” These reasons, it must be admitted, are not satisfactory. It is true that the defendant partner, in case of a recovery and payment, will have the right of contribution against the witness; and it is equally so, that the witness discharges himself from one half of an admitted responsibility, if the judgment, obtained by means of his evidence, is followed by successful execution. If a witness was to admit on his voir dire that he expected by I1Í9 evidence to cast on another, a portion of a burthen which he otherwise would have to bear alone, it barely admits a doubt that he would be incompetent, and we cannot shut out the fact, that in every ease of this description, this would be the result contemplated. On the other hand the case of co-trespassers is strikingly, if not precisely, analogous; — not because a recovery against one is a bar to an action against the other ; but because the satisfaction of tho judgment would be an extinguishment of the right of action against the witness. A Court of justice would not, probably, allow the satisfaction of a judgment against one co-trespasser against the wishes of a plaintiff who desired to proceed against others for the same trespass and therefore a satisfaction could not be made without his consent. The reason why this course would be allowed in the case of joint trespassers is-to enable the plaintiff to proceed until he has obtained a verdict satisfactory to himself, or until he has exhausted his remedies against all the co-trespassers. This, of course, could not be pursued as against partners, or rather there would be no use in such a course, as the recoveries must necessarily be the same against each partner. Whether this difference creates a distinction between the cases of partners and co-trespassers, or whether the latter forms an exception to the general rules of evidence, is not now necessary to be determined.
As the adjudications on this subject are not satisfactory, let the *72question be brought to the test of well established and admitted rules of evidence. A witness is incompetent when he is directly interested in the event of the suit, or when he can avail himself of the verdict so as to give it in evidence on any future occasion in support of his own interest. (Smith vs. Prayer, 7 Term 60; Bent. vs. Baker, 3 Ib. 27.) It is certain that a verdict obtained on the evidence of a partner could be of no avail to the witness in any suit by him, and it could be given in evidence against him in a suit for contribution ; the caséis, therefore, not within the latter clause of the rule. The meaning of the term direct interest, which is spoken of in the rule, requires some examination. A direct interest is one which is certain and not contingent or doubtful. (Rex. vs. Bray., Hard. 360; Bent. vs. Baker, Smith vs. Prayer, supra.) But is an interest contingent or doubtful which only requires the aid of an execution to enforce it ? If it were so there is a very small class of cases which could be considered as certain; perhaps none except those in which the witness had previously received the benefit. A witness who is to receive a portion of the thing recovered, and nothing, if a recovery is not had, is clearly incompetent j so likewise a distributee is incompetent to increase the distributable fund : yet in each of these cases the successful prosecution of the judgment by execution, or by a' voluntary payment is essential before the interest becomes certain ; until then it is doubtful whether it ever will be productive, and the interest is contingent on the collection. We do not see how a matter, which is dependent alone on the successful prosecution of an execution, to which the law ascribes great potency, can be considered as uncertain, or otherwise than direct, in the sense of the rule.
If then, the judgment which is obtained on the evidence of a partner will enure to his benefit when collected, by discharging him from the payment of a portion of a sum of which he otherwise might have been compelled to pay the whole ; it cannot be said that he has no interest in the suit, or that it is uncertain, doubtful, or contingent in the legal sense of these words. Whenever by operation of a judgment at law, without the act of the party, a debt or right of action will be extinguished or lessened* *73we must consider the extinguishment, whether in whole or in part, as the necessary result of the verdict, and a witness who is interested to produce such a result, is by the general rules of evidence incompetent without a release.
We have preferred to rest our decision of this question on the reasons given, rather than on authorities which might have been cited ; we cannot, however, injustice omit the case of Purviance vs. Dryden [3 S. & R. 402] in which the Supreme Court of Pennsylvania arrived at the same conclusion on a similar state of facts. [See also McVorough vs. Goods, 1 Dall. 62; 2 Ib. 50.]
Our conclusion is that the witness Barry was incompetent, and ought not to have been permitted to testify.
4. The exception to the decision of the Circuit Court, that this witness should be permitted, when he was asked if he had not made other statements than the one to which he then deposed, to enquire as to the particular time or transaction to which the question related, is free from error. We have before adverted to the decision of the English Judges in the Queen’s case. The rule then settled is most salutary, and its object is to prevent a witness from being discredited on account of a contradiction in statements made by him, which may be compatible with the strictest veracity. It is obvious that a mere general interrogatory to the witness, whether he had ever made statements different from that sworn to, would in most instances be nothing more than asking him to discredit himself; this, the law will not allow, and if the object of the defendant was to show that he had made other statements, the witness was entitled to know when or to whom they were made, in order that he might, if he could give a satisfactory explanation.
5. The presumption, arising from letters proved to be written by the defendant, would not be rebutted by showing letters written by other persons acting under his advice or at his request; this, in effect, would permit a defendant to make evidence in his own behalf. There was therefore no error in refusing to permit the letter written by the witness to Lawrence, Keese & Co. to be read for this purpose ; though as we have already shown it ought to have been read in another aspect of the case.
*746. Evidence of meddling in the affairs of the firm of Lewis & Barry, if given in general terms, would have been objectionable, because it would be impossible to ascertain what was meant by such an expression ; but the exception here is not to the generality of the evidence, but to its effect, as not conducing to prove the issue. It is too clear to require illustration that if one acts or meddles in the concerns of a firm as if he was interested therein, the specific acts are proper evidence to be left to the jury for them to determine the character in which such acts were performed,
It only remains to announce the result of our opinion, which is, that the judgment of the Circuit Court is reversed for the refusal to permit the defendant to read the letter and for allowing the witness Barry to testify. The cause is remanded for further proceedings.