2. When there are conflicting claims.

30. It is enacted¹ by the 8th section of the act of July 4, 1836, that whenever an application shall be made for a patent, which, in the opinion of the commissioner², would interfore with any other patent for which an application may be pending³, or with any unexpired patent which shall have been granted, it shall be the duty of the commissioner to give notice thereof to such appli-cants or patentees; as the case maybe; and if either shall be dissatisfied with the decision of the commissioner on the question of priority, right or invention, on a hearing thereof, he may appeal from such decision, on the like terms and conditions as are provided in the preceding section of this act and like proceedings⁵, shall be had, to determine which, or whether either of the applicants⁷ is entitled to receive a patent as prayed for.

31. And by the 16th section of the same act, that whenever there shall be two interfering⁸ patents, or whenever a patent on application shall have been refused on an adverse⁹ decision of a board of examiners, on the ground that the patent applied¹⁰ for would interfere¹¹ with an unexpired patent previously¹² granted, any person interested in any such patent, either by assignment or otherwise, in the one case, and any such applicant⁶ in the other, may have remedy by bill in equity¹³; and the court having cognizance thereof, on notice to adverse parties and other due proceedings had, may adjudge and declare either the patents void in whole or in part, or inoperative and invalid¹⁴ in any particular part or portion of the United States, according to the interest which the parties in such suit may possess in the patent or the inventions patented, and may also adjudge that such applicant is entitled, according to the principles and provisions of this act, to have and receive a patent for his invention, as specified¹⁵ in his claim, or for any part thereof, as the fact of priority of right or invention shall in any such case be made to appear. And such adjudication, if it be in favor of the right of such applicant, shall authorize¹⁶ the Commissioner to issue such patent, on his filing a copy of the adjudication, and otherwise complying with the requisitions of this act. Provided, however, that no such judgment¹⁷ or adjudication shall affect the rights of any persons except the parties to the action and those deriving¹⁸ title from or under them subsequent to the rendition of such judgment. And the commissioner is vested by the 12th section of the act of March 3, 1839, with powers to make such rules and regulations in respect to the taking of evidence to be used in contested cases before him, as may be just and reasonable.

32. The act of March 3, 1839, section 10, provides, that the provisions of the sixteenth section of the before recited act shall extend to all cases where the patents are refused for any reason whatever, either by the commissioner of patents or by the chief justice of the district of Columbia, upon appeals from the decision of said commissioner, as well as where the same shall have been refused on account of, or by reason of interference with a previously existing patent; and in all cases where there is ne opposing party, a copy of the bill shall be served upon the commissioner of patents, when the whole of the expenses of the proceeding⁴ shall be paid by the applicant, whether the final decision shall be in his favor or otherwise.