The objection to the witness Jackson went upon the assumption that a verdict for the plaintiffs would be evidence in favor of the witness, on a bill filed by him for an infringement of the patent in the counties in which he was interested, and would afford competent proof of the fact that its validity had been established by a suit at law, and, also, that the defendant’s stove was an infringement, all which would lay the foundation for an injunction against the defendant, restraining him, and all persons claiming under him, from making or vending the article.
On examination, we are satisfied that this view of the question is not well founded. As a general rule, a party cannot be a witness in his own cause, nor will he be permitted to avail himself, by indirect means, of evidence which would be rejected as incompetent if offered directly. The inference, therefore, that would seem to follow, upon the admission of the witness in this particular case, is, that the verdict could not be evidence in his favor, as it would be virtually permitting a party to testify in his own cause. The argument assumes that the verdict would be evidence, which is against the general principle. Reject the verdict, and there is no objection to the competency of the witness. The question is, which shall be excluded, the verdict or the witness. We think the former.
In cases of criminal prosecutions for a cheat, perjury, &c., the party aggrieved is a competent witness for the prosecution. Some early cases may indeed be found in which he was excluded as interested, on the ground that the conviction might be used by him, in a proceeding in equity for relief against the fraud; but it is now fully settled otherwise, the record of conviction being held inadmissible in the civil procedings, in all those cases where the party has been used as a witness on behalf of the prosecution. King v. Boston, 4 East, 572; Bartlett v. Pickersgill, Id. 577, note b; Peake, Ev. 45, 46, 153, 154; 1 Phil. Ev. (4th Am. Ed.) 50, 120; Rex v. Hulme, 7 Car. & P. 8; Maybee v. Avery, 18 Johns. 352.
The verdict in this case, even if in favor of the plaintiffs, could, under no circumstances, be evidence for the witness on a trial at law or in equity, for the purpose of establishing his title to the patent, in other words, on a trial upon the merits, as it is a proceeding inter alios. It is admissible only on a motion for a provisional injunction to stay the defendant from infringing pending the litigation, as affording strong evidence of the validity of the patent, and of the title of the plaintiff; not for the purpose of influencing the final result, but of preserving the rights of the parties in the meantime. In this preliminary proceeding the parties are not tied down to the strict rules of evidence, the object being to enable the court to exercise a sound discretion in granting or refusing the injunction. Hence the depositions of the parties are frequently read on the motion; also the record of any previous trial on the same patent. And, in this view, and for this purpose, it may well be that it is allowable, even though the party had himself been used as a,witness. But when thus allowed as evidence, it is apparent that it is not used in the sense of the rule of law which would exclude a party as an interested witness on the ground that the record of the verdict would be evidence in his favor. It is evidence only in cases where his own deposition would be competent, cases in which the application is to the sound discretion of the court.
For these reasons we are satisfied that th» witness Jackson was improperly rejected, and that a new trial must be granted.