never used by the inventor, and which were introduc

ed merely to mislead the public.18

The concealment in the specification of what is necessary to a knowledge of the machine, is fatal to patent, no less than the introduction of facts intended to mislead.19

the

Sec. VI.-THE SPECIFICATION MUST BE FULL, CLEAR,

AND EXACT.

The specification must not only be true, it must also be full instead of being partial; clear, in distinction from its being obscure and ambiguous, and exact, in distinction from its being vague, loose, and indefinite. These requisites are, however, laid down by judges, in some instances, with too great strictness and severity. In some of the English cases, a jealousy of patent rights as an infringement of the rights of the com→ munity by the common law, has formerly led the judges to a very strict construction against patentees. Thus in the case on Turner's patent, Mr. Justice

18 The King v. Arkwright, Dav. Pat. Cas. 129, 139, 140. See also infra, Sec. 8; Hill v. Thompson, 2 J. B. Moore, 448; Liardet v. Johnson, Bull. N. P. 76; 1 T. R. 608; Turner v. Winter, 1 T. R. 602.

19 Gray & Osgood v. James and others, 1 Pet. C. C. R. 196; Wood v. Zimmer, Holt's N. P. C. 58.

Ashhurst says, as every patent is calculated to give a monopoly to the patentee, it is so far against the principles of law, and would be a reason against it, were it not for the advantages which the public derive from the communication of the invention after the expiration of the time for which the patent is granted. It is, therefore, incumbent on the patentee to give a specification of the invention in the clearest and most unequivocal terms, of which the subject is capable. And if it appear that there is any unnecessary ambiguity affectedly introduced into the specification, or any thing which tends to mislead the public, in that case the patent is void."20

The doctrine on this subject is stated with less severity in a more recent case, in which it is said that every patent being a monopoly, that is, an infringement of public right, and having for its object, to give the public warning of the precise extent of the privilege conferred on the patentee, the court is bound to require that such warning should be clear, and accurately describe what the inventor claims as his own. If the instrument contain any ambiguity on a material point, that is a ground on which it may be avoided altogether."

20 Turner v. Winter, 1 T. R. 602.

21 Campion v. Benyon, 3 Brod. & Bingh. 5.

Mr. Justice Story says, upon this subject, that "it ought to appear with reasonable certainty, what the patentee claims, and that it should not be left to minute references and conjectures from what was previously known.'

1122

In another case the same judge remarks, that a general statement that the patented machine is in all material respects, (without stating what these are) an improvement on an old machine, is no specification at all.23

24

Mr. Justice Washington also considered an ambiguous, unintelligible specification, as in effect, no specification at all. And Mr. Justice Story, speaking of a specification of an improvement in a machine, says, "If the terms be so obscure or doubtful, that the court cannot say what is the particular improvement which the patentee claims, and to what it is limited, the patent is void for ambiguity."25

In a more recent case, the same judge lays down the law on the subject very distinctly, in giving his

22 Lowell v. Lewis, 1 Mason's R. 189.

23 Barrett v. Hall, 1 Mason, 489.

24 Kneass v. Schuylkill Bank, C. C. U. S. Penn. Oct. 1820, Coxe's Dig. 532

25 Barrett v. Hall, 1 Mason's R. 476; and see M'Farlane v. Price, 1 Stark. R. 199.

opinion upon the specification, in the case of Ames's patent for an improvement on a machine for papermaking. He says, "Let us see what is the invention as claimed by the inventor in this case. I agree that if he has left it wholy ambiguous and uncertain, so loosely defined, and so inaccurately expressed, that the court cannot, upon a fair interpretation of the words, and without resorting to mere vague conjecture of intention, gather what it is, then the patent is void for this defect. But if the court can clearly see what is the nature and extent of the claim, by a reasonable use of the means of interpretation of the language used, then the patentee is entitled to the benefit of it, however imperfectly and inartificially he may have expressed himself. And for this purpose, we are not to single out particular phrases standing alone, but to take the whole in connexion."'26

The case in which the above remarks were made, is an illustration of the doctrine laid down by the judge. In the specification, the patentee, after describing the machinery and apparatus for making paper, to which his patent related, proceeded, "I do not claim the felting, vats, rollers, presses, wirecloth, or any separate parts of the above described machinery or ap

26 Ames v. Howard, 1 Sumner's Rep. 485.

paratus, as my invention.

What I claim as new and

The

as my invention, is, the construction and use of the peculiar kind of cylinder above described, and the several parts thereof in combination for the purpose aforesaid." The cylinder had been described particularly, together with the construction and operation of the machinery and apparatus generally. question was, whether, under this specification, the patentee had claimed and patented the cylinder and the several parts thereof, in combination with each other. Upon this construction, the court remarked that it would be mere tautology, for if the patentee claimed the cylinder, this was a claim of the several parts thereof in combination, and, vice versa, if he claimed the several parts in combination with each other, this was nothing more nor less than claiming the cylinder. This construction was to be avoided if any other could be put, not inconsistent with the specification generally, that would give significance to the words. The court was accordingly of opinion "that the patent was for the construction and use of the peculiar kind of cylinder, and the several parts thereof in combination with the other parts of the machinery, for the purpose of making paper." To make this specification clear, it was necessary to insert, after combination, the words, "with the other machinery," and