to, or a sufficient defence when given in evidence on the general issue, on an action brought for the infringement of a patent right.'

9927

The ground of a similar interpretation is taken away in the law of 1836, since it contains no provision for declaring the patent void in such an action. The question then comes up under that law, what is the construction and effect of the 15th section? One thing is plain, that it does not preclude all other defences than those enumerated, for it does not provide for the case of an obscure specification from which it is not practicable to say what was patented, and yet the defence must be admissible in such a case, first, because the plaintiff cannot recover for violating a privilege which is not intelligibly described, and so cannot be known; and second, be- . cause the sixth section of the same act requires that the patentee shall give a description in full, clear and exact terms, and the court cannot disregard this provision. The notion might be suggested that the commissioner is to decide conclusively on the sufficiency of the specification in this respect, and his making out the patent is a certificate of his decision. But this construction is by no means admissible or practicable, for neither the court or jury can say that a privilege is infringed, of which no intelligible description is given.

27 Grant v. Raymond, 6 Peters's S. C. R. 218.

It is another defence not enumerated, that the plaintiff is not assignee; or that his assignment is not recorded.

But what proves conclusively that all the admissible defences are not enumerated in this section of the law of 1836, is, that the defence that the defendant never made, used or sold the thing patented, is not enumerated.

If, then, the section does not preclude all other than the enumerated defences, what is its construction? We shall find an answer to this inquiry in the decisions on the sixth section of the act of 1793, the languaage of which, in respect to the particular question under consideration was similar, viz. the defendant" shall be permitted" to give in evidence on the general issue such and such grounds of defence, of which notice had been given to the plaintiff. On that section Mr. Chief Justice Marshall, giving the opinion of the court, said, "The 6th section of the act appears to be drawn on the idea that the defendant would not be at liberty to contest the validity of the patent on the general issue. It therefore intends to relieve the defendant from the difficulties of pleading, when it allows him to give in evidence matter which does affect the patent. But the notice is directed for the security of the plaintiff, and to protect him against that surprise to which he might be exposed, from an unfair use of this privilege. The notice is substituted for a special

plea; it is further to be observed, that it is a substitute to which the defendant is not obliged to resort. The notice is to be given only when it is intended to offer the special matter in evidence on the general issue. The defendant is not obliged to pursue this course. He He may still plead specially, and then the plea is the only notice which the plaintiff can claim."'28

"The

So in a later case the same court says, defendant is permitted to proceed according to the sixth section, but is not prohibited from proceeding in the usual manner, so far as respects his defence; except that special matter may not be given in evidence on the general issue unaccompanied by the notice which the sixth section requires."29

The effect of the fifteenth section of the act of 1836, then, is, that in making the defences enumerated therein, the defendant must either plead specially or plead the general issue and give the notice required.

28 Evans v. Eaton, 3 Wheaton, 454; and see Evans v. Kremer, 1 Pet. C. C. R. 215, and 3 Wheat. 803, n.

29 Grant v. Raymond, 6 Pet. S. C. R. 746.

CHAPTER XX. '

Evidence in an Action for an Infringement.

Sec. 1. On the part of the Plaintiff. 2. On the part of the Defendant. 3. Admissibility of Witnesses.

Sec. I.-ON THE PART OF THE PLAINTIFF.

WHERE the defendant pleads the usual plea of the general issue, the first evidence produced by the plaintiff, in an action for an infringement, is the patent and specification, and the assignment of the patent, if it be assigned. Certified copies of these from the patent office are made evidence.' In England the enrollment of the specification in due time must also be proved.2

Where the patent was for an improvement on a machine previously patented, Lord Tenterden ruled that the specifications of both inventions must be given in evidence. He said he would not say "what are improvements on a given thing without knowing what the thing was before." But this must cer

1 Stat. of 1836, s. 4.

2 Watson v. Pears, 2 Camp. R 294. 3 Lewis v. Davis, 3 C. and P. 502.

tainly depend upon the manner in which the specification of the improvement is drawn up. If it refer to the former specification, so as, in fact, to include and incorporate it in itself, in the same manner as American patents include the specifications, then such former specification should doubtless be produced; but if the specification is sufficiently intelligible in itself, without recurring to the former one, there would not be the reason given by Lord Tenterden for requiring the production of the former specification.

Where an exemplification-that is, a certified copy under seal—of a patent is admissible, the statutes of 3d and 4th Ed. 6, c. 4, and 13 Eliz. c. 6, provide that an exemplification of only the part which is material, shall be necessary. But a mere extract is not admissible where it might operate as a surprise upon the opposite party, or deprive him of any benefit he might derive in case the whole were produced.4

The drawings, being a part of the specification, are produced in evidence with it.

In one case Mr. Justice Washington let unintelligible specifications and drawings-that is, those which he himself professed not to understand-go to the jury, that they might decide upon them for themselves.5

* Attorney General v. Taylor, Prac. in Chan. 59; See Godson on Pat. 178.

Gray & Osgood v. James & others, 1 Pet. C. C. R. 376.