tinct, and should infringements upon his patent oblige him to resort to a court of justice, he will in doing so, have the legal and moral benefit of a prima facie presumption of the validity of the right he seeks to vindicate.

Inventors have at times erroneously supposed that the grant of a patent after the examination as to novelty and utility is conclusive upon those questions, and that a patent is a guarantee of the novelty and utility of the invention claimed therein. This, of course, is a mistake. An application for a patent is an ex parte proceeding, of which the public at large know nothing. That this should be so, is essential for the protection of the interests of inventors, If before the grant of a patent, the particulars of any claim of invention should be allowed to become matter of public notoriety, very mischievous consequences would be likely to follow.

There are never wanting unscrupulous and narrow-minded men, who if allowed the opportunity would exercise all means in their power to impede and harass inventors and hinder them from attaining their rights. To publish applications for patents would be to invite conspiracy and factious opposition of all kinds from interested parties, with results injurious not only to inventors, but to the peace and morals of society.

It is requisite, therefore, to provide that no claim of invention

shall be published prior to the grant of a patent till then the only parties cognizant of the claim are, as a rule, the applicant and his attorney, if he have one, and the Patent Office.

But it is an inviolable maxim that the rights of individuals cannot be bound by proceedings to which the individuals affected were not a party.

Hence the members of the public at large cannot be bound by those proceedings in the Patent Office relative to applications for patents, of which the law does not permit them to know, or to become parties therein. Any member of the public, therefore, is at liberty to show by proper proof, if he can, in legal proceedings upon a patent, that the invention claimed therein was not new or original with the patentee; that it is not useful, or that for other reason the patent should not have been granted, or is invalid.

The patent is prima facie evidence in any suit, for the patentee, this far that the officials authorized by law have after due examination granted the patent, as for a new and useful invention, which the patentee has sworn that he believes to be his own, and which, in the opinion of these officials, he has clearly and sufficiently set forth and claimed in his specification.

But it may very well be that the patentee was mistaken in his belief that the invention was original with himself, or that he may have taken

a false oath, and it may also be that members of the public whose rights the patent may affect, can by facts and proof which were not before the Patent Office, show that such was the case, or that the invention is not useful, or that it is not so clearly and sufficiently described as to enable those skilled in the art to which the invention appertains, or with which it is most nearly connected, to make use of it, from the information which the specification conveys. Any of these defences as well as others which it is not to our purpose here to speak of, since they are fitter subjects for a legal than for a practical treatiseany member of the public is at liberty to make in a suit which a patentee may bring against him for infringement of the patent. The burden is upon him, however, to establish any of such defences by clear and unmistakable proof, in order to overcome the weight of the primâ facie presumption which the existence of a patent raises in favor of the holder.

Mere technical defences against patents are not favored, but the courts will always so construe specifications and claims that if possible the patent may stand.

While, therefore, a patent is not to be taken as in any sense a guarantee of the patentee's rights, but on the contrary, any member of the public sued for alleged infringement of a patent is at full liberty to show, if he can, that the patent should

not have been granted, and that therefore, the grant of it conferred no lawful right upon the patentee, the latter may be sure that he will not have to contend against hostile judicial criticism which would give a favorable ear to those technical pleas to which dishonest defendants will be likely to resort.

But though the tendency of our courts is to deal in a liberal spirit with the rights of patentees, this liberality of course cannot extend so far as to give effect to patents palpably deficient in respect to any of the legal requirements. Litigation not unfrequently has the effect of showing the patentee that his patent is defective in some material particular; and that, therefore, his right under it is not such as a court of justice can maintain and enforce. If this defect lie in total lack of novelty or utility in the invention claimed, it is of course beyond remedy. But it may be that the defect consists in the lack of one of these requisites in some part only of the thing claimed, or merely in the mode in which the invention is described or claimed. In its liberal dealings with the rights of patentees, whose patents are thus only partially or technically defective, our law is distinguished from that of any other country.

Under the English law, in a suit for infringement of a patent, proof that the patent includes more than was new and original with the patentee, is altogether fatal to the suit.

Our statutes, however, provide (section 60) that if, through inadvertence, accident, or mistake, and without any wilful default, or intent to defraud, or mislead the public, a patentee shall have claimed in his specification to be the original and first inventor or discoverer of any material or substantial part of the thing patented, of which he was not so, he or his legal representative may yet maintain suit at law or in equity for the infringement of any part thereof which was bona fide his own, provided it shall be a material and substantial part of the thing patented, and be definitely distinguishable from the parts claimed without right, notwithstanding the specification may embrace more than that of which the patentee was the original or first inventor or dis

coverer.

It will be noted that a patent which is too broad cannot under this section be partially effective, unless upon the face of the patent as it stands the old and the new matter be clearly distinguishable and separable, and the new matter be a material and substantial part of the thing patented. If the old and new matter are not thus definitely distinguishable, the patent as it stands is altogether bad, and no suit can be maintained upon it; but such a state of affairs is not fatal to the inventor's right: he may remedy the error in a mode which we shall allude to hereafter.

The provision in favor of pat

entees in the section we have quoted is very properly coupled with the condition that in such case no costs shall be recovered in the suit, unless the proper disclaimer has been entered at the Patent Office before the commencement of the suit; nor shall the patentee be entitled to the benefit of the section if he shall have unreasonably neglected or delayed to enter said disclaimer.

4,

This proviso is to protect the public against the carelessness or bad faith of patentees, who might wittingly mislead and deceive the public by continuing to claim that which they themselves were aware they had no right to claim.

It is the right of the public that no patent should purport to grant to the patentee more than he is fairly entitled to. The true extent of his right should distinctly appear on the face of his patent, that the public may be informed of it.

When, therefore, a patentee shall have discovered that his claims include more than that of which he was actual first inventor, he acts in bad faith towards the public, from whom he holds his patent, if he delays to rectify the error, and reduce his claim to its legitimate extent; and much more does he act in bad faith if, with such knowledge, he attempts to enforce submission to his unjust claim by proceedings in the courts.

When, therefore, a patentee discovers that his patent covers more than that of which he was the ac

tual first inventor, and finds that the old matter is definitely distinguishable and separable from the new, he is morally bound to avail himself without delay of the section of the law which permits him to remedy such an error by filing in the Patent Office what is termed a

Disclaimer.

This is a statement in writing, signed by the party disclaiming, attested by one or more witnesses, and recorded in the Patent Office, making disclaimer of such parts of the thing patented as the party in interest shall not choose to claim or hold by virtue of the patent. The right to file a disclaimer is not confined to the patentee, but his heirs or his assigns, whether of the whole or of a sectional interest in the patent, have the like right. Of course, when the assignee of a sectional interest makes such a disclaimer, his interest only is affected by it.

But it is not every patent which is too broad that can be thus cured. The remedy of disclaimer is of course applicable only to cases where the patent specifies and claims divisible features of invention. The part retained and the part disclaimed must be clearly separable and distinguishable, and the part to be retained must be a material and substantial part of the thing originally patented. When, therefore, the patent is not thus divisible, when the original claim is not of such character as to allow of a correction of the patentee's

error by cutting out some clearly separable part, the removal of which will yet leave in the patent a material and substantial patentable subject of claim, the remedy of disclaimer cannot be resorted to.

Now there are very many patents inadvertently made too broad, in which the character of the invention, or of the description or claim, would prevent any such rectification of the patent by mere excision. In such case the patentees would be without remedy, and would find themselves deprived of all right without default of their own, a state of affairs by which very many really meritorious and useful inventors would be irreparably injured.

To obviate such mischief the law has provided the remedy of

Reissue.

This provision is one which has no parallel in any other patent law, and is one of those really beneficent measures which have tended to make our law so effective, because so just and liberal.

Section 53 of the act provides, that "whenever any patent is inoperative or invalid, by reason of a defective or insufficient specification, or by reason of the patentee claiming as his own invention or discovery more than he had a right to claim as new, if the error has arisen by inadvertence, accident, or mistake, and without any fraudulent or deceptive intention, the Commissioner shall, on the surrender of such patent, and the payment of the

duty required by law, cause a new patent for the same invention, and in accordance with the corrected specifications, to be issued to the patentee, or in the case of his death, or assignment of the whole, or any undivided part of the original patent to his executors, administrators, or assigns, for the unexpired part of the term of the original patent, the surrender of which shall take effect upon the issue of the amended patent."

For patents which are too broad the remedy of reissue is applicable, when the defect is such as to render the original patent altogether inoperative or invalid, because the character of the invention, or of the description and claim is such that there is no material or substantial part of the thing patented, which being truly and justly the patentee's own, is clearly separable and distinguishable in the patent as it stands from that which is not the patentee's own. In other words, the remedy of reissue is applicable when that of disclaimer is not.

A patent which being too broad may yet be remedied by disclaimer, is not in its original condition altogether inoperative and invalid, but, as we have seen, is by the terms of the law valid, for all that which being a material and substantial part of the thing patented is truly and justly the patentee's own.

Upon such a patent, and for the infringement of such material and substantial part thereof as is bonâ

fide the patentee's own, he is allowed to maintain a suit, because such part is definitely distinguishable and divisible in the patent as it stands from the parts claimed without right, which latter may, therefore, be removed from the patent by simple excision.

But a patent which being too broad must be remedied by surrender and reissue, is inoperative and invalid, and no suit can be maintained upon it, because the old and new matter cannot be separated in the description and claim as they stand; no distinct part can be taken away and still leave a material and substantial part of the thing patented, definitely distinguishable from the parts claimed without right. Division therefore being impossible, and since the patent as it stands, not being so divisible is wholly invalid, the only remedy is reconstruction of the description and claim, and this can be effected by way of surrender and reissue.

But it is not only as a remedy for patents, which, being too broad, cannot be cured by disclaimer, that reissue is available. It is, in fact, a sort of universal medicine-a cure for all the ills that specifications and claims are heir to. The section we have quoted makes the remedy of reissue available whenever, through innocent inadvertence, accident, or mistake, a defective or insufficient specification renders the patent inoperative or invalid.

The importance of this is appar