CHAPTER IV.

EVIDENCE.

§ 356. THE evidence, appropriate to the different stages of a patent cause, may be divided into (1) the evidence of title, and (2) the evidence upon the point of infringement. Evidence of title relates to the letters-patent, and the plaintiff's interest therein, the novelty and utility of the invention, and the sufficiency of the specification. Evidence of the infringe- ment relates to the identity of the thing made, used, or practised by the defendant, with the invention of the patentee.

§ 357. I. As to the plaintiff's title. With regard to the letters-patent, the Statute of 1836, § 4, 5, makes a copy, under the seal of the Patent Office and the signature of the commissioner, competent evidence that a patent has been granted by the government, for the invention described in the specification annexed. If the patent, produced in evidence, refers to the description in a former patent, it is necessary to produce and read that former patent, in order to show what the invention is, if it is not made entirely clear and intelligible, by the patent on which the action is brought.1

§ 358. The letters-patent being thus proved to have issued, they are prima facie evidence that the patentee was the first inventor of the thing patented.2 The reason, upon which

1 Lewis v. Davis, 3 C. & P. 502.

2 Alden v. Dewey, 1 Story's R. 336; Woodworth v. Sherman, 3 Story's R. 172; Stearns v. Barrett, 1 Mason, 153. It is also held, in England, that the patent is primâ facie evidence, on the part of the person claiming the right that he is so entitled. Minter v. Wells, Webs. Pat. Cas. 129.

this is held, is, that our statute requires the patentee to make oath, that he is the first and true inventor of the thing; and, when the patent has issued, supported by this oath, the burden of proof is cast upon the party who would object, to show that the grant has been improperly obtained by the patentee; because the law presumes, in the first instance, that the patent has been granted upon the proofs which the statute requires to be laid before the officers of the government, and that those proofs were satisfactory.1

1 In the Philadelphia and Trenton Railroad Co. v. Stimpson, 14 Peters, 485, Mr. Justice Story, delivering the opinion of the Supreme Court of the United States, said: "Now, the objection is, that the present patent does not contain any recitals that the prerequisites, thus stated in the act, have been complied with, namely, that the error, in the former patent, has arisen by inadvertency, accident, or mistake, and without any fraudulent or deceptive intention; and that, without such recitals, as it is the case of a special authority, the patent is a mere nullity and inoperative. We are of opinion that the objection cannot, in point of law, be maintained. The patent was issued under the great seal of the United States, and is signed by the President, and countersigned by the Secretary of State. It is a presumption of law, that all public officers, and especially such high functionaries, perform their proper official duties, until the contrary is proved. And where, as in the present case, an act is to be done, a patent granted, upon evidence and proofs to be laid before a public officer, upon which he is to decide, the fact that he has done the act, or granted the patent, is primâ facie evidence that the proofs have been regularly made, and were satisfactory. No other tribunal is at liberty to reëxamine or controvert the sufficiency of such proofs, if laid before him, when the law has made such officer the proper judge of their sufficiency and competency. It is not, then, necessary for the patent to contain any recitals, that the prerequisites to the grant of it have been duly complied with, for the law makes the presumption; and if, indeed, it were otherwise, the recitals would not help the case, without the auxiliary proof that these prerequisites had been, de facto, complied with. This has been the uniform construction, as far as we know, in all our courts of justice, upon matters of this sort. Patents for lands, equally with patents for inventions, have been deemed primâ facie evidence that they were regularly granted, whenever they have been produced under the great seal of the government, without any recitals or proofs that the prerequisites, under which they have been issued, have been duly observed. In cases of patents, the courts of the United States have gone one step further, and, as the

§ 359. When the patentee wishes to strengthen this evidence, either in the opening of his case, or to rebut any evidence offered by the defendant, which may have tended to show that he was not the first inventor, he can only call persons who were in the way of hearing of the invention, if it had existed before, to testify that they have not heard of it. The proposition which the plaintiff has to establish, is, strictly, a negative; he is to prove that the invention did not exist before; and, therefore, as has been said, he must proceed by exhausting the affirmative instances of it, by calling those persons who might have known of it, if it had existed before, but who never have heard of it; and the more those persons, from their acquaintance with the particular trade or manufacture, were in the way of hearing of or meeting with it, the stronger the evidence will be.1

§ 360. Although this evidence is only general and negative, it is not, on that account, without weight. To illustrate its force, as well as its proper office, we may suppose a case, where the defendant had succeeded in showing, that some prior inventor had made experiments in the same line as the patentee, and that this evidence goes so far as to show, that that person had probably accomplished the same result as the patentee; but the point is still left in doubt, whether he had actually reached and perfected the invention for which the plaintiff has obtained a patent. The rule of law, in such cases, is, that, if the prior efforts of some preceding inventor rested in experiment alone, his experiments, however near they may have been carried to the complete production of the thing, will not prevent a subsequent more successful inventor, who has produced the perfect result at which both

patentee is required to make oath that he is the true inventor, before he can obtain a patent, the patent has been deemed primâ facie evidence that he has made the invention."

1 Cornish v. Keene, Webs. Pat. Cas. 503; Galloway v. Bleaden, Ibid.

526.

may have aimed, from obtaining a valid patent. The question for the jury will therefore be, in such cases, whether the efforts of the prior inventor rested in experiment alone, without coming to the point of completion, both in the theory and the actual application of the invention. Upon this question, the fact, that the invention was never heard of until it was known to have proceeded from the present patentee, is of great weight. If it had been heard of among those persons who make it the business of their lives to know what is going on in the particular trade or art which it concerns, or to know what inventions, in all arts or trades, are, from time to time, produced, prior to the time when it was made by the patentee, the presumption would be very strong that the person, who is proved to have made near experiments towards it, had actually accomplished the perfect result. Still, the evidence would not be conclusive, because the report, that such an invention had been made, might have arisen from what had been done in the way of experiment alone. But it would be very strong presumptive evidence that the experiments had terminated successfully, if persons, who were in the way of hearing of such inventions, should testify that they had heard of such an invention having been announced, although they had not seen it. On the other hand, if such persons had not heard of such an invention, the evidence would not show conclusively that the prior experiments rested in experiment alone, but it would have a very strong tendency to establish this conclusion, because there is an irresistible tendency in inventions to

1 If such persons had seen the thing, no further inquiry would be necessary, for the proof would be positive, that the thing existed before. But the evidence we are here considering, relates merely to the fact of such persons having or not heard of the invention, which fact, if shown in the affirmative, of course must be aided by proof of its having been made by somebody, and would not, alone, be conclusive proof of its actual previous existence.

become known, as to their results, if not as to their processes, whenever the results are accomplished.1

§ 361. There is one other species of evidence, applicable to the issue of novelty, when the question is as to the time when the patentee had completed his invention. It may be necessary for the plaintiff to rebut evidence, offered by the defendant, as to the invention and use of the same thing by other persons, before the date of his patent, and hence it may be important to show the precise time when the invention was completed by the patentee. For this purpose, the patentee may give in evidence his own declarations, as part of the res gesta, describing the nature and objects of the invention, to an extent which has been defined by the Supreme Court of the United States.2

1 The case of Galloway v. Bleaden, Webs. Pat. Cas. 521, 525, presents a state of facts similar to that which we have supposed in the text. Two witnesses, conversant with subjects of the description of the patented invention, and who devoted themselves to the knowledge of the inventions made from week to week, testified that they had not before heard of such a discovery, previous to the issuing of the plaintiff's patent. The Court said, this was enough to call on the other side, to show affirmatively that the invention was not new, and that it was for the jury to say whether the evidence, as to what had been done by the antecedent experiments or efforts of others, in the way in which it ought to be understood, had brought their minds to that conclusion.

2 "In many cases of inventions, it is hardly possible, in any other manner, to ascertain the precise time, and exact origin, of the particular invention. The invention itself is an intellectual process, or operation; and, like all other expressions of thought, can, in many cases, scarcely be made known except by speech. The invention may be consummated and perfect, and may be susceptible of complete description in words, a month, or even a year, before it can be embodied in any visible form, machine, or composition of matter. It might take a year to construct a steamboat, after the inventor had completely mastered all the details of his invention, and had fully explained them to all the various artisans whom he might employ to construct the different parts of the machinery. And yet, from those very details and explanations, another ingenious mechanic might be able to construct the whole apparatus, and assume to himself the priority of the invention. The conversations and