A state court has no power to enjoin proceedings in a court of the United States; especially in a suit at law for damages for the infringement of a patent, so expressly, if not exclusively, confided by law to the federal courts. If it had such power, it would be no ground for equitable interference, when the defences relied upon in equity are equally available at law, that parties, who were not at the time of trial examinable as witnesses, have since been made so, in the state courts, by statute. A circuit court of the United States has, irrespective of the citizenship of the parties, power to entertain a bill for discovery in aid of the defences to a suit for the infringement of a patent, as ancillary to such suit, if not by the express authority of the 17th section of the act of congress, passed July 4, 1836, entitled "An act to promote the useful arts, c."
AMES, C.J.
We have not the power, if we had the inclination, to enjoin proceedings in the courts of the United States; ( Mc Kim v. Voorhies, 7 Cranch, 279; 2 Story's Eq. Jurisp. § 900, and cases cited;) and should hardly think of commencing so novel an enterprise in a case for the infringement of a patent, which is expressly, if not exclusively, confided by law to those courts. 5 U.S. Statutes at Large, 124; 2 Kent's Com. 368, and cases cited. Nor does this bill by its allegations furnish us with the least excuse for such interference beyond our proper limits. It discloses no defence to the claim for damages in the suit at law, which was not equally available in that suit, as it would be in a court of equity, whether the defence be by way of license, or of estoppel, or because the machines of the defendants were constructed before the plaintiff's application for a patent. The suggestion in the bill, that when this case was tried in the circuit court of the United States for this district, parties were not allowed, as now in our state courts, to be called, or to offer themselves as witnesses, affords not the slightest ground for our interference. It would not, upon a bill for a new trial, had the trial at law been in our own courts; ( Briggs v. Smith and another, 5 R.I. Rep. 213;) and certainly cannot excuse us for trespassing upon the settled jurisdiction of the courts of the United States. The plaintiffs are mistaken in supposing, that if they had applied in time, they might not have been assisted by the circuit court in their defences, by way of discovery. Irrespective of the citizenship of the parties, the court would have entertained, at the suit of either, a bill of discovery, as ancillary to the suit at law, under the authority of Dunn v. Clark, 8 Peters, 1; if indeed it would not have been empowered to do so by the express authority of the 14th section of the act of Congress, passed July 4, 1836, and entitled, "An act to promote the useful arts," c. 5 U.S. Statutes at Large, 124.
In any view of this bill, whether we look at what it asks us to do, or the grounds which it lays for our action, it must be dismissed with costs.