after four years from the date of the patent be made to the Comptroller for its revocation either immediately or at a reasonable time after the application. If, however, the patentee can satisfy the Comptroller (or, on appeal from him, the Court) that he has done his best to comply with the directions of the Act, the patent will not be revoked.2

The invention for which a patent is asked must of course be novel "within this realm;" the applicant must declare that he is the true and first inventor or the assign of the inventor, and that the invention "is not in use by any other person to the best of his knowledge and belief." Then the invention must be such that it is a proper subject for the grant of a patent. It must be the invention of some manufacture or art. Abstract ideas cannot be patented, nor can mere scientific discoveries. The discoverer must also manufacture some thing by means of which the public can derive benefit from the discovery. "An invention is not the same thing as a discovery. A man who discovers that a known machine can produce effects which no one before him knew could be produced by it may make a great and useful discovery; but if he does no more, his discovery is not a patentable invention. He has added nothing but knowledge to what previously existed. A patentee must do something more: he must make some addition not only to knowledge, but to previously known inventions, and must so use his knowledge and ingenuity as to produce either a new and useful thing or result, or a new and useful method of producing an old thing or result." Lastly, the invention must be useful; it must be "for the public good." The patent cannot be supported unless the invention, when put into practice, is useful for the purpose indicated by the patentee. But a very small degree of utility will be sufficient."

In an action for the infringement of a patent the burden rests upon the plaintiff to prove two things:

1 S. 27.

2 See In re Bremer's Patent, [1909] 2 Ch. 217.

8 21 Jac. I. c. 3, s. 6; Brown v. Annandale (1842), 8 Cl. & F. 437. Per Lindley, L. J., in Lane For v. Kensington, &c., Lighting Co., [1892] 3 Ch. at pp. 428, 429.

Wilson v. Union Oil Mills (1892), 9 R. P. C. at p. 20.

• Welsbach v. New Incandescent Co., [1900] 1 Ch. 843.

(i.) that he is the original grantee, or the duly constituted assign of the original grantee, of letters patent;1 and

(ii.) that the defendant has infringed the right conferred by those letters patent.

(i.) The plaintiff must in the first place prove his patent. This he can do by putting in a printed or written copy or extract, certified by the Comptroller of Patents and sealed with the seal of the Patent Office. A patent may be granted to two or more co-owners jointly for an invention made by one or some of them,3 in which case each of them, in the absence of any special agreement, may use and work the patent for his own profit, and each therefore may maintain an action for its infringement. If the plaintiff be not the original patentee, he must formally prove the various assignments by which the patent right has been transferred from the original patentee to himself.

If the defendant has denied the novelty of the invention, it was formerly held that the plaintiff must, in the first instance, give some slight evidence of this by calling some one conversant with the trade to state that the invention was unknown before the letters patent were granted." But the modern practice is that the plaintiff establishes a primá facie case on this issue by proving his patent. He thus throws the burden of proof on the defendant, who must show, if he can, some prior use of the invention in this country, or some prior publication in this country of some intelligible description of the plaintiff's invention. The production of the letters patent is prima facie proof that they were rightly granted, and that all facts existed necessary to bring the case within section 6 of 21 Jac. I. c. 3.8

1 One of several co-owners of a patent may sue alone for an infringement of his right: Sheehan v. G. E. Ry. Co. (1880), 16 Ch. D. 59; and so may one of several co-owners of a trade mark: Dent v. Turpin (1861), 30 L. J. Ch. 495. 2 S. 79; and see s. 78.

3 S. 1.

Steers v. Rogers, [1892] 2 Ch. 13.

Sheehan v. G. E. Ry. Co. (1880), 16 Ch. D. 59; Van Gelder Co. v. Sowerby Bridge Society (1890), 44 Ch. D. 374.

Turner v. Winter (1787), 1 T. R. 602; but see Penn v. Jack (1866), L. R. 2 Eq. 314.

? See Harris v. Rothwell (1887), 35 Ch. D. at p. 427.

* Amory v. Brown (1869), L. R. 8 Eq. 663.

(ii.) The question of infringement is one of mixed fact and law, but often more a question of fact than of law. Any use of the article or invention which is the subject of the plaintiff's patent without his leave, any application of it for the defendant's own profit except by way of bona fide experiment, is an infringement.' The question is " whether the mode of working by the defendant is essentially or substantially different." A slight deviation from the process described in the specification made by the defendant for the purpose of evading the patent will not protect the defendant; for it is a fraud. If the defendant substitutes a well-known equivalent, chemical or mechanical, for any part of the invention, this is a mere colourable variation and therefore the goods which he sells are still an infringement. A patent for a combination of several things, old and new, is infringed by an imitation of that part which is new." But where the patent is for a new result coupled with an effectual process, the use of the use of any other process attaining the same result is an infringement.5 It is no infringement to sell the separate parts of a patented combination with the knowledge that they will be used by the purchaser to form the combination.6

4

It is an infringement to import from abroad articles there made by the patented process; but an agent who merely passes such goods through the custom house and obtains leave to store them in the importer's warehouse is not guilty of any infringement.8 Where articles infringing a patent are made abroad, the Court has no jurisdiction to restrain the foreign manufacturer, even though he made them with the intention of sending them to England; and he himself does not infringe the patent. Evidence that the defendant

1 Frearson v. Loe (1878), 9 Ch. D. 48, 66, 68.

2 Per cur. in Hill v. Thompson (1818), 8 Taunt. at p. 391.

3 Dudgeon v. Thomson (1877), 3 App. Cas. 34.

4 Sellers v. Dickinson (1850), 5 Exch. 312.

5 Badische, &c., Fabrik v. Levinstein (1883), 24 Ch. D. 156; affirmed (1887), 12 App. Cas. 710.

• See the extract of the judgment of Jessel, M. R., in Townsend v. Haworth (1875), cited in the note to Sykes v. Howarth (1879), 12 Ch. D. at p. 831. Von Heyden v. Neustadt (1880), 14 Ch. D. 230.

Nobel's Explosives Co. v. Jones (1882), 8 App. Cas. 5.

Badische, &c., Fabrik v. Basle Chemical Works, [1898] A. C. 200.

imported into England and sold here articles in imitation of the patented article is evidence of infringement, whether the defendant knew that they had been copied from the patented article or not.1

It will be open to the defendant to urge at the trial that he never infringed the plaintiff's letters patent. He may also contend that the patent is invalid on the following grounds :

(a) that the patent was obtained by fraud, e.g., by false suggestion or recital in the letters patent;

(b) that the inventor has not by his complete specification particularly described the nature of his invention, or that the provisional specification did not describe its true nature, or that the invention which it described is not the same as that described in the complete specification;

(c) that the said alleged invention is not new; 2

(d) that the said alleged invention is not the proper subjectmatter of letters patent; .3

(e) that the plaintiff is not the first and true inventor of the said alleged invention; or

(f) that the alleged invention is not useful.

He may also on the same grounds claim the revocation of the plaintiff's patent or counterclaim for damages on the ground that he holds a patent which the plaintiff has infringed.*

5

The procedure in an action for the infringement of a patent is minutely regulated by the Patents and Designs Act, 1907, and by Order LIII.A of the Rules of the Supreme Court made thereunder. The plaintiff usually claims damages as well as an injunction to restrain future infringement. If he succeeds, he may elect whether he will have a decree for an inquiry as to the damage which he has sustained and payment of the amount so assessed, or a decree for an account and payment of the profits made out of the infringement of his patent. He cannot, however, get both

1 Walton v. Lavater (1860), 29 L. J. C. P. 275.

See Rolls v. Isaacs (1881), 19 Ch. D. 268; Anglo-American, &c., Co. v. King, [1892] A. C. 367; Gillette Safety Razor Co. v. A. W. Gamage, Ltd. (1909), 25 Times L. R. 808.

8 Harwood v. G. N. Ry. Co. (1862), 2 B. & S. 222; Murray v. Clayton (1872), L R. 7 Ch. 570, 584.

4 S. 32.

The action cannot be brought in the county court: R. v. County Court Judge of Halifax, [1891] 2 Q. B. 269.

against the same defendant. If the defendant can show that he was not aware, and had not reasonable means of making himself aware, of the existence of the patent he will not be liable to pay damages for the infringement, although the patentee can obtain an injunction restraining him from any further infringement. But the plaintiff will not be entitled to an injunction if the Court is satisfied that no danger of future infringement exists. If, however, an infringement be threatened by the defendant, the Court will grant an injunction although no actual infringement has yet taken place.+

Besides obtaining an injunction to prevent the defendant from further infringing his patent, the plaintiff may, in the discretion of the Court, obtain an order that the infringing articles be destroyed or delivered up to him, or be otherwise so treated as to prevent future infringements. The mere fact that the defendant is in possession of articles which are an infringement of a patent, though it entitles the plaintiff to an injunction, does not entitle him to an order for their destruction or delivery up. The plaintiff may also in the same action sue for the recovery of royalties from any person alleged to be a licensee on making him a defendant.7

II. COPYRIGHT.

Every man, who wrote a book, poem or any other original composition, had at common law the exclusive right to multiply copies of it, so long as it remained unpublished; and this common law right is now recognised by statute. A statute of Anne gave to authors a further right, viz., the exclusive right of multiplying copies of their works for fourteen years after publication." The Copyright Act, 1842,10 extended the period of copyright to the author's natural life and seven years after his death, or forty-two years from the date of publication, whichever period was the longer. The period of copyright for any work, whether published or unpublished, has now been enlarged to the life of the author

De Vitre v. Betts (1873), L. R. 6 H. L. 319.

2 S. 33. Marking the article "patented," &c., is not sufficient notice, unless the year and number of the patent be also given : s. 33.

3 Proctor v. Bayley (1889), 42 Ch. D. 390.

Frearson v. Loe (1878), 9 Ch. D. 48.

Betts v. De Vitre (1864), 34 L. J. Ch. 289, 291; Tangye v. Scott (1865), 14 W. R. 386; Edison Bell Co. v. Smith (1894), 11 R. P. C. 389; Mabe v. Connor, [1909] 1 K. B. 515.

6 United Telephone Co. v. London and Globe Telephone Co. (1884), 26 Ch. D. 766, 7 Wilson v. Union Oil Mills Co. (1892), 9 R. P. C. 57.

1 & 2 Geo. V. c. 46, s. 31; but nothing in this section shall be construed as abrogating any right or jurisdiction to restrain a breach of trust or confidence," as to which see Perceval v. Phipps (1813), 2 Ves. & B. 19, 29; Gee v. Pritchard (1×18),

2 Swans, 402.

98 Anne, c. 19.

10 5 & 6 Vict. c. 45, s. 3.