tions of improvements in munitions of war, and of any patent obtained for the same, and to prevent the disclosure of such inventions.

The effect of the forty-fifth section is that patents issued or applied for before the commencement of the Act will not have the benefit of the provision binding the Crown, nor will they come under the liability imposed by the clauses relating to compulsory licences. But in all other respects, including the amount and time of payment of fees and the proceedings for amendments, prolongations, and revocations, the new Act will extend to patents granted before the commencement of the Act, or on applications then pending, except that if the patent is three years old the 100l. duty cannot be paid by instalments.

By the thirty-fifth section of the new Act a patent granted to the true and first inventor is not to be invalidated by an application in fraud of him, or by provisional protection obtained thereon, or by any use or publication of the invention, subsequent to that fraudulent application during the period of provisional pro

tection.

The 113th section of the Patent Act of 1883 repeals all the statutes described in the third schedule of the Act, but goes on to enact that the repeal shall not affect the past operation of any of those statutes. Now, the twenty-fifth section of the Patent Act of 1852 declares that any British patent which bears date after a foreign patent for the same invention (being a foreign invention) shall be void at the expiration of such foreign patent. Consequently, any British patent granted before the commencement of the new Act, and standing in this relation to a foreign patent, will be void by the operation of these two clauses, in case the foreign patent shall have expired before the commencement of the new Act. That is to say, since the earlier Act has

already rendered the British patent void, that 'past operation' of the Act will not be affected by its repeal by the Act of 1883. But if the twenty-fifth section of the earlier Act at the time of its repeal has not had any invalidating operation on a patent, then the British patent will not be touched, and the clause in question will have no effect. As regards patents which have been obtained on applications pending at the commencement of the new Act, it is presumed that the third subsection of the forty-fifth section of that Act will effectually protect them from the operation of the twenty-fifth section of the Act of 1852.

It has been held by Baron Huddleston in the case of Nordenfeldt v. Gardner (R. P. C. vol. i. p. 10) that an order to invalidate a British patent on the ground of the invention being a foreign invention for which a Belgian patent had been obtained prior to the date of the British patent and had lapsed, the foreign patent must have been not merely applied for, but actually obtained before the British patent, and this, although the foreign patent when granted actually bore a date earlier than that of the British patent.

When a patent is granted to two or more persons, each may use the invention without being liable to account to the other (Mathers v. Green, 1 Law Rep. Ch. Ap. 29, before Lord Cranworth, C.). See, however, the earlier case of Hancock v. Bewley (Johns. 601), as to the rights of parties where letters patent are vested in trustees for two or more persons as tenants in common.

In case of the death of the patentee intestate before the expiration of the patent, his interest under it passes to his personal representatives, and not to his heir.

CHAPTER X.

AMENDMENTS OF SPECIFICATIONS.

IT has been shown in Chapter III., that where a material part of an alleged invention is not new or not useful, the patent is altogether invalid; and that if a patentee claims by his specification more than he is entitled to, the patent is likewise void (see Chapter VII.). The fatal effect of an inconsistency between the title and the specification (Chapter V.), or between the provisional and the complete specification, has also been pointed out (Chapter VII.). To remedy a law which in many cases bore unjustly upon patentees, the Act of 5 and 6 Wm. IV. c. 83, empowered a patentee to take steps for altering his specification by disclaimer. That Act, however, as well as other Acts relating to disclaimers, were repealed by the Patent Act of 1883, which substituted the following provisions for those of previous statutes. By the eighteenth section it is enacted that

(1) An applicant or a patentee may from time to time, by request in writing left at the Patent Office, seek leave to amend his specification, including drawings forming part thereof, by way of disclaimer, correction, or explanation, stating the nature of such amendment, and his reasons for the same.

(2) The request and the nature of such proposed amendment shall be advertised in the prescribed manner, and at any time within one month from its

first advertisement any person may give notice at the Patent Office of opposition to the amendment.

(3) Where such notice is given the Comptroller shall give notice of the opposition to the person making the request, and shall hear and decide the case subject to an appeal to the law officer.

(4) The law officer shall, if required, hear the person making the request and the person so giving notice, and being in the opinion of the law officer entitled to be heard in opposition to the request, and shall determine whether and subject to what conditions, if any, the amendment ought to be allowed.

(5) Where no notice of opposition is given, or the person so giving notice does not appear, the Comptroller shall determine whether and subject to what conditions, if any, the amendment ought to be allowed.

(6) When leave to amend is refused by the Comptroller, the person making the request may appeal from his decision to the law officer.

(7) The law officer shall, if required, hear the person making the request and the Comptroller, and may make an order determining whether and subject to what conditions, if any, the amendment ought to be allowed.

(8) No amendment shall be allowed that would make the specification, as amended, claim an invention substantially larger than or substantially different from the invention claimed by the specification as it stood before amendment.

(9) Leave to amend shall be conclusive as to the right of the party to make the amendment allowed, except in case of fraud; and the amendment shall in all courts and for all purposes be deemed to form part of the specification.

(10) The foregoing provisions of this section do not. apply when and so long as any action for infringement

or other legal proceeding in relation to a patent is pending.

The procedure on applications for amendments is regulated by Rules 48-56 of the Patents Rules 1883 and by the Law Officers Rules which will be found in the Appendix. The law officers have now power to examine witnesses on oath (sect. 38).

By the nineteenth section it is enacted that in an action for infringement of a patent, and in a proceeding for revocation of a patent, the Court or a judge may at any time order that the patentee shall, subject to such terms as to costs and otherwise as the Court or a judge may impose, be at liberty to apply at the Patent Office for leave to amend his specification by way of disclaimer, and may direct that in the meantime the trial or hearing of the action shall be postponed. The Court of Appeal in Singer v. Stassen (1 R. P. C. 122), held that liberty to apply for disclaimer during action should be given upon the terms that the costs of the amendment should be the defendants', and that the specification, as amended, should not be receivable in evidence in the action; and in Codd v. Bratby (1 R. P. C. 209), Mr. Justice Chitty held that leave to amend should be given upon the terms that the specification when amended should not be given in evidence at the trial, and that no evidence of infringement should be given prior to the date of filing the amended specification.

The twenty-first section directs that every amendment of a specification shall be advertised. This will be done by the Comptroller under Rule 56.

There is no appeal from the order of the law officer when he grants or refuses leave to amend on the appeal to him from the decision of the Comptroller.

It had become a common but not invariable practice under the old law for the law officers, on applica