there be any invention at all. 5. Anything impugning the title of the invention: and, 6. The specification. The formal accuracy of the patent and specification are not often really in question.

In framing the pleas, not guilty denies the breach in the declaration. The other pleas are to the title. Non concessit (Bedells v. Massey, 8 Jur. 808; Bunnett v. Smith, 13 M. & W. 552) denies the existence in complete form of the letters patent. The title is referred to by a plea of false suggestion in obtaining the patent (Morgan v. Seaward, 2 M. & W. 544); the letters patent reciting the petitioner's allegations. The inventorship and novelty are required by the statute of James, and mentioned in the letters patent: (Stead v. Anderson, 4 C. B. 806; Househill Co. v. Neilson, Webs. 689.)

Utility is denied by a plea of no manufacture: (see the statute of James), or of no utility, referring to the petition recited in the patent: (Bedell v. Massey, 2 Dowl. & L. 322; Morgan v. Seaward, supra; Jupe v. Pratt, Webs. 151.) The specification derives from the patent grant not from any law (Bentley v. Goldthorpe, 9 Jur. 470) as to setting it out, if not already so done: (Muntz v. Foster, 1 Dowl. & L. 741.) A plea of no specification enrolled, standing by itself, denies both the substantial and formal sufficiency. If it follow a plea of no sufficient specification, it will be referred to the enrolment only: (Leaf v. Topham, 2 Dowl. & L. 863.) As to invalidity under the terms of the patent, by transfer to more than twelve persons, see McAlpin v. Mangnall (3 C. B. 496; 15 L.J. 298, C. P.) As to a plea of informal execution of a disclaimer, see R. v. Mill, &c. (1 Pract. Rep. 695.) The substantial defects of it will lie in its extending the right.

Pleas are not allowed to the whole invention and the undisclaimed remainder (Clark v. Kenrick, 1 Dowl. & L. 392), but they are allowed to a part of the invention and the whole (Bentley v. Keighly, 1 Dowl. & L. 944.) In the Electric Telegraph case (20 L. J. 123, C. B.) pleas

were entered to each head of claim. The invention being single, any part that fails is a failure as to the whole.

As to estoppels, see Oldham v. Langmead (cit. 3 T. R. 439); Bowman v. Taylor (2 A. & E. 278); and Baird v. Neilson (8 Cl. & Fin. 726.) In Betts v. Betts (Vice Chancellor Knight Bruce, 1851), it was doubted whether the right could be tried without a plea of not guilty, and an admission of the facts was ordered, instead of omitting the plea. The verdict for the defendant on the title does not affect the issue on the infringement, the patent being unrepealed, though it would affect the damages if asked for: (Neilson v. Harford, Webs. 311; Sealy v. Brown, 14 L. J. 169; 9 Jur. 537.)

Drawings are not admissible in the pleas (Betts v. Walker, 14 Jur. 647), and precision is requisite in citing the title (Stead v. Carey, 1 C. B. 496.) The notice of objections is peculiar to Patent Law (5 & 6 Will. 4, c. 83, s. 5); it is not applied to Scotland, where particulars are otherwise afforded (The Househill Co. v. Neilson, Webs. P. C. 552, 711, 714); the section was enacted in inadvertence to the special pleas already given by the new rules, and is open to similar abuses; thus, in one case ninety-six objections were talked of. They are loosely worded, usually more numerous than the pleas (Neilson v. Harford, Webs. P. C. 370), multiplying them rather by varying the phrase than by substantial division, and are usually described as an echo of them; and the vague terms of the act have led to contradictory cases on them, so that authors say each case stands on its own merits: (Jones v. Berger, Webs. 544.) The broadest rule laid down was (Bulnois v. Mackenzie, 4 Bing. 127; Losh v. Hagen, 7 Dow. 495; Webs. 202) that they must be deemed to require somewhat more specialty than the pleas, but this cannot be relied on; the pleas may be definite enough (Russell v. Ledsam, 11 M. & W. 647; Neilson v. Harford, Webs. P. C. 364), and they are not to argue the case: (Heath v. Unwin, Webs. 552.) As to amendment by the judge, see R. v.

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Walton (2 Q. B. 969); Betts v. Walker (14 Jur 647); they must certainly be within the pleas, and cannot be objected to at the trial: (Neilson, supra.) They are not on the record, but like particulars (Betts v. Walker, 14 Jur. 647), and to be read at the opening of the case and do not give a reply. If omitted to be delivered (see Losh v. Hagen, 7 Dow. 495) as to pleading de novo.

As to the matters for objection: not guilty need not be, but is usually included; nor the existence of a patent, or anything apparent on the face of it. Fraud, in obtaining a patent, must be specially stated (Russell v. Ledsam); the cases seem to show that if a part of the invention be alluded to, what part must be specified; but the objecting to the whole invention is usually sufficient (Neilson v. Harford, supra) on the point of novelty, the names of previous inventors or patentees, or of books describing the invention have sometimes been required (Galloway v. Bleadon, 2 Chit. Arch. P. 1031, Webs. 522; Jones v. Berger, 5 M. & G. 208; Edwards v. Da Costa, Repert. Patents, 680.) The trial is usually by special jury, and the assizes in a manufacturing district may be preferred, or a particular judge who, having been Attorney-General, may be more familiar with patents. The burden of proof is rather on the plaintiff; i. e., in an action for infringement the patentee; in scire facias, his assailant.

A jury leans, in modern times, to favour a patent, especially when the utility of the invention is conspicuous, and even the objection of want of utility comes ungracefully from a man who has used the invention, while it is usually obvious that the patentee was practically the introducer, even if some obscure remote instance had preceded, which is raked up by a man who in fact would, but for the patent, have continued in unacquaintance with it. The history of the invention is interesting, and exhibits the merit of the inventor; and scientific questions relieve the length of trial, but patents are by law granted for manufactures, and they are apt to lead away from the

manufacturing question. The extent of the manufacture often is mentioned at the outset, when the individual article (a button, &c.) would seem trivial, and the defects of former articles and the efforts made by prior inventors to remove them illustrate the merit of the plan by which they were ultimately overcome. Counsel read the specification which is the text of their argument.

The trial is not unfrequently protracted and difficult; patent law lies in but few elementary principles, and is not much a matter of technical law; but the combination of the leading principles afford a variety of combinations, and these, unless closely watched, shift or pass into one another; thus, by extending the principle, you endanger the novelty; if you narrow the principle the infringement escapes. Some pains must be spent sometimes to get at the merits of a mechanical point; the then Mr. Copley spent, it is said, ten days in getting up the action and adjustment of some lace machinery. A passage in Newall v. Webster, (26 Lond. Jour. C. S., printed case) illustrates the attention required on such points. It was material to see whether one strand of a piece of wire rope was twisted in itself as well as round the central core; the judge (whose scientific reputation stands high) suggested that certain visible appearances were a demonstration of the twist, and the argument proceeded in some measure on this assumption, but the fallacy of the test, however, was afterwards recognised and stated on motion in Banco. The Lord Chief Baron at once admitted it, and added, "considering the very great skill and mechanical and scientific talent and ingenuity you had about you, I really wonder that so simple a matter (the moment you mentioned it) was not pointed out; I was certainly taking all the pains I could."

The importance of drawings, specimens, and working models (explained by competent witnesses) is evident: the experiment too may be performed, and the merit of the result judged of; thus, in Edwards v. Da Costa (Repert. Arts, No. 680), potatoes were cooked and handed round

for tasting: (Lord Abinger, it is said, refused a musician in a copyright case leave to play a tune on his violin.) The judge explains the drawings of the specification to the jury, who take them and the models, &c., into their private room to deliberate on.

As to witnesses, the patentee who knows the origin, &c., of the invention was hitherto usually incompetent from interest; a licensee is not excluded (Derosne v. Fairrie, 1 Moo. & Rob. 457), though his credit may be affected according to circumstances; he may in some cases be a gainer by setting the patent aside; a party not directly interested may as an assignor be under covenants to support the right.

The trade are more or less openly in opposition to the patentee; other patentees will sympathize with him, unless their rival inventions clash.

Mercantile men form another class, who speak to the utility of the article, and the extent of the demand; and official persons, when there has been use by the navy, ordnance, &c. Workmen and others give evidence on practical points. But there is a class requiring special notice, known as scientific witnesses. They have indeed been repeatedly complained of by the judges, nor is the reason obscure; they deal in words and principles, rather than on facts. In fact, while nominally witnesses, they are really advocates; and their superior cognizance of that "matter" in which the case is "immersed," gives them a serious amount of influence, while they gradually and insensibly acquire an art of preparing experiments, and giving evidence to support or destroy an invention. This applies, for instance, to the intelligibility of the specification, which must materially depend on the precise temper in which it is set about; a man willing to be puzzled or misled by it would probably succeed. But their aid is indispensable; and perhaps the consciousness of their efficiency, especially because known to be enlisted on one side of the argument (and perhaps in the