at the Patent Office for leave to amend his specification by way of disclaimer." It has already been noticed that where leave to apply has been granted and the amendment allowed, without a term being imposed that the amendment shall not be retrospective, then the specification must be tested by the provisions of sect. 20, and the amendment will only be retrospective in its action if it can be clearly shown that the original claim was framed in good faith and with reasonable knowledge.. CHAPTER XII. THE DEVOLUTION OF A PATENT. We have seen that a "patentee" is "the person for the time being entitled to the benefit of a patent." This includes the first inventor and any person or persons in whom the patent may have become vested by operation of law or by assigment. The property of a patent passes, by operation of law, when the patentee dies or becomes a bankrupt. Upon the death of a patentee his interest in the property passes to his executors or administrators as the case may be in the like manner to the rest of his personal estate. Any step which in the Act is required to be taken by the patentee, may be taken by the executor or administrator, and sect. 34 of the Act provides that-" (1) If a person, possessed of an invention, dies without making application for a patent for the invention, application may be made by, and a patent for the invention granted to, his legal representative." This undoubtedly, seeing the terms of the grant itself, will mean his legal personal representative (a). Some letters patent of the Crown (not for inventions) have a limitation to heirs or heirs male, such, for instance, as patents of nobility. If the patentee becomes bankrupt the property in the patent will pass to his receiver, trustee or assignee in bankruptcy (b). It is doubtful whether the doctrine of apparent possession can be said to affect a patent right. The Lord Chancellor, in 1812, seems to have thought that it did (c). This, however, can hardly be quoted as an authority. The persons in whom the patent (a) See Re Edmund's Patent, Griff. P. C. 281. (b) Hesse v. Stevenson, 3 B & P. 565; see also Bloxam v. Elsee, 9 D. & R. 215; McAlpine v. Mangnall, 15 (c) See Ex parte Granger, Godson on Patents, 2nd ed. p. 225. vests, by reason of bankruptcy, are placed in all respects in the position of the original patentee, and may sue in respect of infringements (d). The second method of devolution is by assignment inter vivos. This may be done either by absolute assignment of the whole of the patent, or by absolute assignment of the patent right for a limited area, or by assignment by way of mortgage, or by the grant of licences. The right of the original inventor to assign the exclusive right which has been granted to him is recognised in the patent itself, which is granted to the said A. B., his executors, administrators or assigns. Without these words of limitation the property in the patent right would be merely personal, attaching to the person of the first inventor and becoming extinguished by his his death. By sect. 36 of the Act, "a patentee may assign his patent for any place in or part of the United Kingdom or Isle of Man, as effectually as if the patent were originally granted to extend to that place or part only." The patent itself being a deed the assignment must also be by deed (e); but a parol agreement to assign will operate as an equitable assignment of the patent (ƒ), and specific performance of such an agreement will be enforced (g). Assignment may be made to any person, or to any two or more persons as tenants in common, or to a body corporate. Executors may assign a patent after the grant, but prior to registration of the probate (h). The assignment of a patent with no express warranty incorporated in the contract, like the assignment of an ascertained chattel, carries with it no implied warranty of its quality (i), and the question to be decided in each case is: "Did the defendants buy a good and indefeasible patent right, or was the contract (d) Bloxam v. Elsee, supra. (e) Co. Lit. 9 b, 172 a; Stewart v. Casey, 9 P. O. R. 9, 13. (f) Stewart v. Casey, 9 P. O. R. 9. (g) Lewin v. Brown, 14 W. R. 640. (h) Ellwood v. Christy, 10 Jur., T. N. S. 1079. (i) Hall v. Conder, 26 L. J., C. P. 138, 142; Smith v. Neale, 26 L. J., C. P. 143, 148; see also 56 & 57 Vict. c. 71, sect. 14, ss. 1. N merely to place the defendants in the same situation as the plaintiff was in, with reference to the alleged patent?” (k). Where the plaintiff purports to assign the exclusive right of selling certain things for the manufacture of which a patent had been obtained, there is in such case an implied warranty that the patent is a valid one, since otherwise it would be impossible to assign such exclusive right (7). Upon assignment of a patent without a warranty the assignee may not, in an action upon the contract of assignment, set up the invalidity of the patent as a defence; the cases and considerations which arise upon this point will be left to be dealt with in the succeeding chapter under the head of "Estoppel." In Re Railway and Electric Appliances Co. (m), the patentees inade an absolute assignment of their patent to the company on the terms that the company should pay to them a royalty upon every article "which should be manufactured or sold by the company" under the patent "while subsisting," and also a share of the profits; through inadvertence the renewal fee at the end of five years from the date of the patent was not paid by the assignors, and it was held by Kay, J., that there was no term in the contract, express or implied, whereby the assignees could be held liable on account of the lapse of the patent and consequent loss of royalties to the assignors. An assignee of a distinct part of a patent is entitled to sue for an infringement of that part without joining the persons who are interested in the remaining part or parts (n). Where an assignee of a patent covenants with the assignor for himself and his assigns that he will work the patent and pay certain royalties thereon to the assignor, a subsequent assignee with notice takes the patent subject to those covenants (o); so too an assignee can maintain a suit against subsequent licensees of the assignor with notice of the assignment, to restrain them from using the patent (p). (k) Per Cresswell, J., in Hall v. Conder, 26 L. J., C. P. 143. (1) Chanter v. Leese, 5 M. & W. 698; Hall v. Conder, 26 L. J., C. P. 143. (m) L. R., 38 Ch. D. 597. (n) Dunnicliff v. Mallett, 7 C. B., N. S. 209; 29 L. J., C. P. 70. (0) Werderman v. Société Générale D'Electricité, L. R., 19 Ch. D. 246. ) Hassall v Wright ht, L. R., 10 Eq. An agreement by the vendor of a patent to assign to the purchaser, all patent rights that he may subsequently acquire of a like nature to the patent then sold, is not contrary to public policy and will be upheld (g); so too a covenant by a licensee for the residue of a term of 14 years, of patented improvements in machinery for slubbing fibrous substances, not to make or vend any slubbing frames whatever without the invention applied to them, was held not to be void as a covenant in restraint of trade, and although the licensee subsequently discovered that the patent was useless and no one could be induced to purchase frames to which it was applied, the Court held that this was no answer to the action (r). Where a grant of letters patent has been made to two or more persons, or has been assigned by the original patentee to two or more persons, each of the co-grantees or co-assignees, has the right to put the invention into practice without incurring the liability to account to his co-owners for the profits which he may make. In Steers v. Rogers, Lord Herschell, in delivering the judgment of the House of Lords, said (s): "Letters patent do not give the patentee any right to use the invention; they do not confer a right to manufacture according to his invention. That is a right which he would have equally effectually if there were no letters patent at all; only in that case all the world would equally have the right. What the letters patent confer is the right to exclude others from manufacturing in a particular way. and using a particular invention. When that is borne in mind it appears to me impossible to hold, under these circumstances, that where there are several patentees, either of them, if he uses the patent, can be called upon by the others to pay to them a portion of the profits which he makes by that manufacture, because they are all of them entitled, or perhaps any of them entitled, to prevent the rest of the world from using it" (t). The rights of co-owners inter se are summed up by Lindley, (q) Printing & Numerical Registering Co. v. Sampson, L. R., 19 Eq. 462; 44 L. J., Ch. 705; 32 L. T. 354; 23 W. R. 463. (r) Jones v. Lees, 26 L. J., Ex. 9; 1 H. & N. 189; 2 Jur., N. S. 645. (t) See also Mathers v. Green, L. R., 1 Ch. 29. |