Of executors and administrators. The tenth section of the act of 1836 provides that, where an inventor dies before obtain ing a patent, his executor or administrator may apply for and obtain such patent, hold ing it in trust for the heirs at law or devisees, accordingly as the inventor died intestate or testate. Nothing is said as to its being appropriated to the payment of debts ; but, having once gone into the hands of the ex ecutors or administrators, it would perhaps becorue assets, and be used like other personal property. In England, a patent will pass as assets to assignees in bankruptcy. 3 Boa. & P. 565 The right to make a surrender and receive a re-issue of a patent also vests by law in the executor or administrator. See Act of 1836, 0 13, The law further provides that the executor or a,dministrator may make the oath necespary tx; obtain the patent,—differing in this re.peot from the case of an assignment, where, although the patent issues to the iis ' signee, the inventor must make the oath.
26. The liability of a patent to be levied upon fbr debt. The better opinion is that letters patent cannot be levied upon and sold by a common-law execution. The grant of privilege to the patentee would, from its incorporeal nature, seem to be incapable of manual seizure and of sale. Even if such a sale were made, there does not appear to be any provision in the acts of congress which contemplates the recording of a sheriff's deed; and without a valid record the patentee might nevertheless make a subsequent transfer to a bona fide purchaser without notice, which would be valid.
But this peculiar species of property may, perhaps, be subjected to tbe payment of debts through the instrumentality of a bill in equity. The chancellor can act upon the person. He can direct the patent to be sold, and by attachment can compel the patentee to execute a conveyance to the purchaser. The assignment thus executed will be re covered, and the transfer will thus become complete.
These seem to be the views deducible from the decisions in 1 Gall. C. C. 458; 14 How. 528 ; 17 id. 448.
27. How far a patent is retroactive. By the earlier law on this subject in the United States, a patent, when granted, operated re troactively : so that a machine covered by the terms of the patent, though constructed previously to the date of that instrument, could not be used after the issuing of the patent without subjecting the party so using it to an action for infringement. Of course the use of the machine previous to the date of the patent was not unlawful.
The seventh section of the act of 1839 provides " that every person or corporation who has or shall have purchased or con structed any newly-invented machine, manu facture, or composition of matter prior to the application by the inventor or discoverer for a patent shall be held to possess the right to use, and vend to others to be used, the specific machine, manufacture, or coinposition of mat ter so made or purchased, without liability therefor to the inventor or any other person interested in such invention."
At present, therefore, property rightfully acquired in a specific machine cannot be affected by a patent subsequently applied for by the patentee. It has been held, how ever, that, under, the general grant contained in the constitution, congress has power to pass a special act which shall operate retro spectively so as to give a patent for an invention already in public use. 3 Wheat, 454 ; 2 Stor. C. C. 164; 3 Surma. C. C. 535. The infringement must be subsequent to the date of the patent ; but on the question of novelty the patent will be considered as re lating back to the original discovery. 4 Wash. C. C. 68, 703.
2S. Of foreign inventors. An alien who has resIded one year in ths United States, and who has taken an oath of.his intention to become a citizen, stands, so far as the pat ent laws are concerned, in the same position as a native-born citizen ; but other foreigners have not in all, respects the same rights and advan togas.
There is still a discrimination in the rate of fees to be paid by the inhabitants of those countries which discriminate against our citizens. See Act of 1861, 2 10. Nor are aliens permitted to file a caveat or to arpply for a patent for a design. In these latter respects the disability may have been unin tentional, but it is nevertheless real. Thera is els° another marked difference made by law between a domestic and a foreign pat entee. The former is under no legal obli gation to bring his invention into nse. He may not only fail to use it himself, but may utterly refuse to allow it to be used by an.y one else upon any terms whatever. In this way he may prevent the .publie from enjoying any benefit from the invention for the vvhole term of fourteen years, without in any respect affecting the rights conferred by his patent. • But if the foreign patentee fails and neglects for the space of eighteen months from the date of his patent to put and con tinue his invention on sale to the public on reasonable terms, his patent is rendered wholly invalid. Act of 1836, 2 15. An American assignee of an alien inventor is not, however, within the provisions of the act ; and even the alien patentee is not bound to prove that he hawked the invention to obtain a market for it ; but it rests on those who seek to defeat the patent to prove that the patentee neglected or refused to sell the patented invention for reasonable prices when application was made to him to purchase. 2 Blatehf. C. C. 49.