Dissenting opinion.

is, "that the specification filed does not contain the whole truth relative to his discovery, or that it contains more than is necessary to produce the described effect, which concealment or addition must fully appear to have been made for the purpose of deceiving the public.” If judgment is rendered for the defendant on this ground, the patent is to be declared void. This section applies as well to patents for an improvement on an existing machine as for an invention entirely new, and was intended to protect the patent in either case against an avoidance for an imperfect and innocent specification of the invention patented. If, therefore, the defect which is alleged really exist in the specification of the patented improvement, the court is not authorized, on its mere inspection, to declare it imperfect, and the patent on that account void. Both questions are clearly questions of fact, and are so treated by the legislature. The party has a right to insist with the jury, not only that his specification is perfect, but that, if it be otherwise, no deception was intended on the public; and on either ground they may find a verdict in his favor. So if, on the allegation that the thing secured by patent was not originally discovered by the patentee, a verdict passes against the plaintiff, he loses his patent. In like manner, in this case, if it had appeared that the "improved hopper-boy," which was the thing secured by patent, had not been originally discovered by Mr. Evans, and a verdict had passed against him on that ground, there would have been an end of his patent. From the tenth section, also, an argument may be drawn against the right of a court to declare a patent void, on mere inspection, for redundancy or deficiency in a specification. This section provides a mode of proceeding before the District Court, where there may be reason to believe a patent was obtained surreptitiously, or upon false suggestions; and if, on such proceeding, it shall appear that the patentee was not the true inventor, judgment shall be rendered by such court for a repeal of the patent. This is the only case in which a power is conferred on a court to vacate a patent without the intervention of a jury. If a proceeding of this kind had been instituted before the proper tribunal against Mr. Evans, the court would have examined witnesses, and have formed its opinion on their testimony; and it is not clear that even in this case a jury might not have been called in. This section has been taken notice of, to show that it could never have been the intention of the legislature that a patent should be avoided, on any account whatever, on the opinion of the court alone, without some examination other than that of the specification, whatever might be its excess or poverty of description. If it had been intended to vest so important a power in the court, it

Syllabus.

would not have been left to mere implication, but would have been conferred in terms admitting of no doubt. My opinion, therefore, on this part of the charge is, that the court erred in taking upon itself to pronounce the patent void, even if the specification had been defective or imperfect in not particularly describing what the improvements of the patentee were, this being a power expressly delegated to a jury, who, under all the circumstances of the case, are to decide both questions of fact; that is, whether the specification be deficient or superfluous, and the intention with which it was made so. I repeat once more, that whatever may have been the decisions in England, which are not admitted to be contrary to the view which has here been taken of the subject, they are not of authority, and are upon an act so very different in its structure from our own as to afford little or no useful information upon the subject. One great and important difference in the two laws is, that the statute of James I. has not prescribed a mode in which a patent for a vicious specification is to be set aside. The patent is granted on condition that a specification be enrolled.

I give no opinion on the questions which arise from the admission of certain witnesses who were supposed to be disqualified on the score of being interested; for if the patent for the hopper-boy be void for a defect in its specification, and that question is not to be referred to the jury, and such I understand to be the opinion of four of the judges, it is very unimportant whether any error was committed in this respect by the court before which the cause was tried, as a verdict must ever be rendered against the representatives of the patentee on this ground, whatever may be the state of the evidence. Mr. Justice JOHNSON and Mr. Justice DUVALL also dissented. JUDGMENT AFFIRMED WITH COSTS.

EVANS V. HETTICH.

(7 Wheaton, 453.)

1. It is no objection to the competency of a witness in a patent cause that he is sued in another action for an infringement of the same patent.

2. The sixth section of the Patent Act of 1793, ch. 156, which requires a notice of the special matter to be given in evidence by the defendant under the general issue, does not include all the matters of defense which the defendant may be legally entitled to make. And where the witness was asked whether the machine used by the defendant was like the model exhibited in court of the plaintiff's patented machine: Held, That no notice was necessary to authorize the inquiry.

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Statement of the case.

3. Where a deposition has once been read in evidence without opposition, it cannot be afterwards objected to as being irregularly taken.

4. It is no objection to the competency or credibility of a witness, that he is subject to fits of derangement, if he is sane at the time of giving his testimony.

ERROR to the Circuit Court of Pennsylvania.

This was an action for the infringement of the same patent as in the preceding case of Evans v. Eaton, and was argued by the same counsel. The points involved will be found to be fully discussed in the argument of that case, to which the learned reader is referred. The following is the charge delivered to the jury in the court below, which it is thought necessary here to insert.

After stating the evidence on both sides, Mr. Justice WASHINGTON proceeded as follows:

The facts intended to be proved by the evidence given in this cause may be arranged under the following heads: (1.) Such as respect the value of the plaintiff's hopper-boy. (2.) The time of its discovery. (3.) The kind of machine used by the defendant. (4.) The time of its discovery and use.

1st. As to the first, the court has no observations to make, except that if you should find a verdict for the plaintiff, you will give the actual damages which the plaintiff has sustained by reason of the defendant's use of his invention, which the court will treble.

2d. The evidence applicable to this head, if believed by the jury, proves that, in 1783, Oliver Evans commenced his investigation of the subject of an improvement in the manufacture of flour; and in the summer of the same year he declared that he had accomplished it. In 1784, he made a model of his hopper-boy, which had no cords, weight, or pulley; and consequently the lower arm was, for the sake of the experiment, turned by the hand. In 1785, it was in operation in a mill, in as perfect a state as it now is.

3d. If the witness who was called to prove the kind of machine used by the defendant is believed by the jury, it consists of an upright square shaft, with a cog that turns it, and which is moved by the water-power of the mill. This shaft is inserted into a square mortise, in an arm or board somewhat resembling an S, with strips of wood fixed on its under side, and so arranged as to turn the meal below it, cool, dry, and conduct it to the bolting-chest. This arm slips, with ease, up and down the shaft, and must be raised by hand, and kept suspended until the meal is put under it. It has no upper arm, pulley, weight, or leading lines; and the strips below the arm are like the rake, as it is called, in the plaintiff's hopper-boy. This

Statement of the case.

machine has acquired the name of the S, or the Stauffer hopperboy.

4th. The witnesses examined to prove the originality and use of the defendant's hopper-boy, if believed by the jury, date it as early as about the year 1765; and its erection and actual use in mills, in 1775 and 1778; and progressively to later periods. Objections have been made, on both sides, to the credit of some of the witnesses who have been examined, not on the ground of want of veracity or of character, but of interest, short of that which can affect their competency. These objections have been pressed so far beyond their just limits as to require from the court an explanation of their real value. Where the evidence of witnesses opposed by other witnesses is relied upon, by either side, to prove a particular fact, the jury must necessarily weigh their credit, in order to satisfy their own minds on which side the truth is most likely to be; and, in making this inquiry, every circumstance which can affect the veracity of the witnesses, whether it concerns their moral character, or whether it arises from some interest which they may have in the question, or from feelings favorable to one or the other of the parties, should be taken into the calculation. But if the fact in controversy may exist without a violation of probability, and the proof is by witnesses exclusively on that side, there is nothing to put into the opposite scale against which to weigh the credit of those witnesses; and if the objection to their credit be worth anything, it must be to the full extent of rejecting their testimony altogether, or else it is worth nothing. The jury cannot compromise the matter, or halt between two opinions, they must decide that the fact is so, or is not so; and if the latter be cause of objection to the credit of the witnesses, it would amount to the confounding of the questions of competency and credibility; for the effect would be the same, whether the court refused to permit the witnesses to testify on the ground of incompetency, or the jury should reject their testimony, when given, on that of want of credibility. I have thought it proper to submit these general observations to the consideration of the jury.

We come now to the question of law which arises out of these facts, which is: What are the things in which the plaintiff alleges, and has proved, he has an exclusive property, which he asserts the defendant has used, and which the defendant denies?

The first claim is for an improved hopper-boy, which the plaintiff insists is granted by his patent, which has received the sanction of the Supreme Court, and which the defendant acknowledges. This being, then, conceded ground, the court will proceed to examine it;

Statement of the case.

and the inquiry will be, whether the plaintiff is entitled to a verdict for an infringement of his patent for his improved hopper-boy. The objection relied upon by the defendant is, that the plaintiff has not set forth in his specification what are the improvements of which he claims to be the inventor so that a person skilled in the art might comprehend distinctly in what they consist. This objection, in point of fact, is fully supported. Neither the specification nor any other document connected with the patent states, or even alludes to, any specific improvement in the hopper-boy. Taking this as true, how stands the law? The third section of the Patent Law declares that "before an inventor can receive a patent he shall deliver a written description of his invention, in such full, clear, and exact terms as to distinguish the same from all other things before known, and to enable a person skilled in the art, &c., of which it is a branch, &c., to make and use the same."

What, then, is the plaintiff's invention, as asserted by his counsel, conceded by the defendant, and sanctioned by the Supreme Court in the case of Evans v. Euton? The answer is, an improvement of the hopper-boy, or an improved hopper-boy, which that court has decided to be substantially the same. If this be so, then the above section of the law has declared that he must specify this improvement in full, clear, and exact terms. If he has not done so, he has no valid patent on which he can recover.

The English decisions correspond with the injunctions of our law. Boulton v. Bull, Bovill v. Moore, M'Farlane v. Price, Harmer v. Playne. See 3 Wheat. Rep., App. 21, ante. The American decisions, so far as we have any reports of them, maintain the same doctrine. Mr. Justice STORY, in the case of Lowell v. Lewis, lays it down "that if the patent be for an improvement in an existing machine, the patentee must, in his specification, distinguish the new from the old, and confine his patent to such parts only as are new; for if both are mixed together, and a patent taken for the whole, it is void." What is the reason for all this?

In the first place, it is to enable the public to enjoy the full benefit of the discovery, when the patentee's monopoly is expired, by having it so described on record that any person skilled in the art of which the invention is a branch may be able to construct it. The next reason is, to put every citizen upon his guard, that he may not, through ignorance, violate the law by infringing the rights of the patentee, and subjecting himself to the consequences of litigation. The inventor of the original machine, if he has obtained a patent for it, and all persons claiming under him, may lawfully enjoy all the