the invention has been patented in this country on an application of prior date; (3) that the complete specification comprises an invention other than that described in the provisional specification, and that the former invention forms the subject of a pending application made by the opponent. If notice of opposition be given at the Patent Office, the comptroller gives notice thereof to the applicant; and after the expiration of the two months, and after hearing the applicant and his opponent or opponents, the comptroller decides on the case, with an appeal to the Law Officer. On such appeal, the Law Officer hears the parties, and (with or without the assistance of an expert) determines whether the patent shall be granted or not (a). If, however, there is no opposition to the grant, or if the opposition thereto is decided in favour of the applicant and against his opponent or opponents, then the comptroller causes a patent to be sealed with the seal of the Patent Office (y)--a simplification of the former practice, under which a warrant for the purpose was first passed by the Commissioners of Patents, and the Lord Chancellor thereupon caused letters-patent for the invention to be sealed with the Great Seal of the United Kingdom. The grant is then recorded in the register of patents at the Patent Office.

So

The object of the complete specification is, of course, to put the public in full possession of the inventor's secret ; that any person may be in a condition to avail himself of it, when the period of exclusive privilege has expired. To prevent this object from being defeated by an evasive or careless description, the specification is construed with great strictness by the courts. And in describing the nature of the invention, the specification whether provisional or complete, must commence with the title of the patent; and, in the case of a complete specification, must end with a distinct statement of the invention claimed (÷).

(x) Patents Act, 1883, s. 11. (y) Ibid. s. 12.

(z) Ibid. s. 5, sub-s. (5) ; Siddell v. Vickers (1890), 15 App. Cas. 496.

The office of the complete specification being to set forth, with more particularity, the subject indicated in the provisional specification or in the patent itself, if one thing he claimed by the patent and another by the specification, the grant is void (a). It is also an objection to the specification, if it covers too much, that is, includes, in its claim of new invention, anything which in fact has been already known and practised. And therefore if the entire article for which the patent is being taken out comprises some matter of this description, in connection with others. that are new, the claim ought to be made in such form as to apply to the latter only; or if the combination of several known things happens to be the only novelty, it is to the combination only that the claim should be directed (b). And as regards the description of the manner of production, the general rule is, that the specification should enable persons of ordinary skill to make the patent article, by simply following the directions given, without resorting to contrivances of their own (c). In framing the specification, no circumstance may be safely passed over which is advantageous, whether absolutely essential or not, in the conduct of the process; and if several methods are stated, the specification will be defective and the patent void, if any of them be found to fail in effecting the promised result (d).

By the letters-patent (which are in general not to be granted after the expiration of fifteen months from the date of the application) there is granted to the applicant the exclusive right of making, using, exercising, and vending (e) his invention within the United Kingdom and the Isle of Man, for the full term of fourteen years, subject to the patentee making the prescribed payments (ƒ).

(a) Nuttall v. Hargreaves, [1892] 1 Ch. 23.

(b) Pneumatic Tyre Co. v. Caswell (1897), 13 R. P. C. 164.

(c) Miller v. Searle & Co. (1893), 10 R. P. C. 106.

(d) Siddell v. Vickers, ubi sup. (e) Patents Act, 1883, s. 12; Patents Act, 1885, s. 3.

(f) See Saccharin Corporation v. Reitmeyer, [1900] 2 Ch. 659.

And such patent right holds good against the Crown (g), at least quodam modo; that is to say, the Crown may still use the patent, but paying therefor what shall be agreed, or (failing agreement) what the Treasury shall appoint (h).

Assignment of patents and licences.--A patent right is assignable either absolutely or by way of mortgage (i) ; and the assignment may be of part even of the patent, or may be for some specific place or country only (k). But in every case, the assignment, to pass the legal interest, must be in writing under hand and seal, though an equitable assignment is effectual without a deed (1). It is also competent to the patentee, without an entire alienation of his interests, to grant licences to any one or more persons to manufacture, use, or sell the subject-matter of the patent; and for the due working of the invention, he may (by an order of the Judicial Committee of the Privy Council made on a reference to it by the Board of Trade of a petition presented by "any person interested”) even be compelled to grant such licences (m). Every assignment, and also every licence, must be registered at the Patent Office in the register of patents (n). For the better conduct of patent business, and with a view also to the public benefit, and to the due publication of the invention, a Patent Journal, reports of patent cases, and indexes of specifications, etc., have been provided at the Patent Office (0); and patent agents must now be registered, if they would describe themselves as such (p).

Extension of letters-patent.-Formerly in favour of a patentee who had not reaped the full benefit of his invention, the legislature frequently interfered, by passing a private Act of Parliament, to secure him the continuance

(g) Patents Act, 1883, ss. 27, 44 ; Feather V. The Queen (1865), 6 B. & S. 257.

(h) Nobel's Explosives v. Anderson (1896), 12 R. P. C. 164.

(i) Steers v. Rogers, [1893] A. C. 232.

(k) Patents Act, 1883, s. 36. (1) Re Casey's Patents, [1892] 1 Ch. 104.

(m) Patents Act, 1902, s. 3. (n) Ibid. s. 23.

(0) Ibid. s. 40.

(p) Patents Act, 1888, s. 1.

of the privilege for a further term of years, in addition to that first limited by the letters-patent. A less costly mode of relief in such cases is now in use; for the grantee may, under such circumstances, apply by petition to the Crown for a prolongation of the existing term, his intention. to do so being first duly advertised (q), and the petition being actually presented six calendar months, at least, before the expiration of the original term. If, upon

consideration of the nature and merits of the invention in relation to the public, of the profits made by the patentee as such, and of the whole matter, and after hearing any party who may choose to enter a "caveat," the Judicial Committee of the Privy Council reports in favour of the application (r), the Crown is empowered either to grant to such patentee, or to his assignee, or to both conjointly, as the case may be, an extension of the term of the patent for a period not exceeding seven years, or (in exceptional cases) fourteen years, to commence after the expiration of the first patent (s); or to order the grant of a new patent for the term therein mentioned, and containing any restrictions, conditions, and provisions that the Judicial Committee may think fit. But, of course, the petition may also be refused altogether (†).

Remedies for infringement.-If a patent right be infringed, the inventor has his remedy by action to recover damages for the injuries sustained (u). In such action he must deliver (with his statement of claim) a document called "particulars of the breaches." He may also in such action obtain an injunction restraining the wrongdoer from the further use of the invention, and compelling him to account for the profits which he may have already

(q) Patents Act, 1883, s. 25; Re Henderson's Patent, [1901] A. C. 616.

(r) Ibid. s. 25, sub-s. (5); Lockwood's Case, [1894] A. C. 347.

(s) Ibid.; Re Hopkinson's Patent, [1897] A. C. 249.

(t) Parson's Patent, [1898] A. C. 673; Re Henderson's Patent, [1901] A. C. 616; Re Peach's Patent, [1902] A. C. 414.

(u) Patents Act, 1883, s. 29; De Vitre v. Betts (1873), L. R. 6 H. L. 319; British Motor Syndi cate v. Taylor, [1901] 1 Ch. 122.

derived therefrom (a); but the penalty of £50 in addition, which was provided by the 5 & 6 Will. IV. c. 83, s. 7, when any person, without licence, used the name, stamp, or mark of any patentee, has been abolished. The defendant in any such action may, of course, defend it, either on the ground that no infringement has taken place, or on the ground that the patent is invalid. In the latter event he must, with his statement of defence, deliver "particulars of his objections" to the patent (y); and the invalidity of the patent may be established by showing, that the article was not a fit subject for a patent, or else that the patentee was not the first inventor, or that the specification was insufficient.

Revocation of patents.-Nor is this the only method of defeating claims founded on an alleged patent right; for, whether there were any complaint of infringement or not, it used to be competent to the Crown (or to any subject of the realm in the name of the Crown, by leave of the Attorney-General) to institute a proceeding called a scire facias for the formal impeachment of the patent; and by the effect of this (if found open to any of the objections above enumerated, or to any other sufficient exception in point of law), the patent would have been cancelled (2). But this species of relief is now obtainable on petition to the court for revocation of the patent, the petition being presented either by the Attorney-General, or by any one authorised by him, or by any aggrieved person (a). The Act requires that the petitioner shall deliver to the inventor particulars of the objections to the patent upon which he intends to rely at the hearing of the petition.

(x) Patents Act, 1883, s. 30; Proctor v. Bayley (1889), 42 Ch. D. 390.

(y) Ibid. s. 29; Crompton v. Anglo-American Brush Co. (1887), 35 Ch. D. 283.

(z) Smith

V. Upton (1844),

6 Man. & G. 251.

(a) Patents Act, 1883, s. 26; In re Avery's Patent (1887), 36 Ch. D. 307.