Mechanical

and

in other words, that you not only have no right to steal the whole, but you have no right to steal any part of another man's invention. And the question, in every case, is a question of fact—is it really and substantially a part of the invention?” (d).

Perhaps patents for combinations are more equivalents. numerous, and the attempts to evade them more

chemical

frequent, than any other description of patent taken out. The means of evasion usually employed are the snbstitution of what are termed mechanical or chemical equivalents in the place of a part or parts of the combination (e). Referring to one kind of evasion-that of colourable imitation-Lord Cairns, in the case of Dudgeon v. Thomson (f), says as follows: "That which is protected is that which is specified, and that which is held to be an infringement must be an infringement of that which is specified. But Colourable I agree that it will not be the less an infringement because it has been coloured or disguised by additions or subtractions, which additions or subtractions may exist and yet the thing pro

imitation.

(d) L. R. 8 Eq. 358; Affirmed on Appeal, 5 App. Cas. 36. (e) Stevens v. Keating (Chemical Equivalent), 2 Webs. P. R. 181; Russell v. Cowley (Mechanical Equivalent), 1 Webs. P. C. 463; Heath v. Unwin (Chemical Equivalent), 5 H. L. C. 505, 543; Muntz v. Foster (Chemical Equivalent), 2 Webs. P. C. 96; Hills v. The Liverpool Gas Company (Chemical Equivalent), 9 Jur. (N. S.) 140; Patent Type Founding Company v. Rich, Johns 381; Parks v. Stevens, L. R. 8 Eq. 258. (f) 3 App. Cas. p. 43.

tected by the specification be taken notwithstanding." "When the result is old, but the means new, the Court will look jealously at the claims of inventors seeking to limit the rights of the public at large for effecting that which has been commonly known to all the world long before" (g).

(C)-CONSIDERATION.

The subject-matter of the invention must be(1) NOVEL.

(2) USEFUL.

(3) ADEQUATELY DESCRIBED.

Novelty.

c. 3, s. 6.

The words of the statute of James, on which the 21 James I. decisions as to novelty are based, are: "All letters patent and grants of privilege of the sole working or making of any manner of new manufactures within this realm which others, at the time of making such letters patent and grants, shall not use" (h).

(9) Judgment of Lord Hatherley in Curtis v. Platt, 3 Ch. D. 135.

(h) See Introduction, p. xxi.; s. 46, p. 93. In the case of Rolls v. Isaacs it was held that the fact that an invention has been used in a British colony before the date of letters patent granted in respect of the invention for the United Kingdom does not invalidate the patent, 45 L. T. (N. S.) 704; Brown v. Annandale (distinguished), 8 Cl. & Fin. 437.

Prior user.

Sale.

Although the statute expressly mentions the word others, yet the decisions extend the fatal consequences of prior user to the inventor himself, on the ground that if the invention is already known the patentee has no further consideration to give the public. If the articles are sold (i), or even offered for sale by the patentee or others (j), this will constitute a prior user. Also the open use of the invention (k), though for private purposes (1), unless for the purpose of experiment, is a When prior prior user (m). If, however, the inventor does not to inventor. allow the public to use his invention, or himself use it in public, he may manufacture before the date of his patent without invalidating the same, provided such user does not result in profit to

Experiment.

user allowed

(i) Wood v. Zimmer, 1 Webs. P. R. 44; Losh v. Hague, 1 Webs. P. R. 205.

() Mullins v. Hart, 3 C. & K. 297; Oxley v. Holden, 8 C. B. (N. S.) 666.

(k) Betts v. Neilson, L. R. 3 Ch. 429; Heath v. Smith, 3 E. & B. 270.

(1) Stead v. Williams, 2 Webs. P. R. 130; Stead v. Andrews, 2 Webs. P. R. 149.

(m) Galloway v. Bleaden, 1 Webs. P. R. 529; Cornish v. Keene, 1 Webs. P. R. 501; Jones v. Pearce, 1 Webs. P. R. 122 ; Carpenter v. Smith, 1 Webs. P. R. 534; Hills v. Gas Light & Coke Company, 5 H. & N. 312.

If profit is made by the inventor during what are found to be merely experiments, this will not invalidate the patent; but good cause must be shown, such as the necessity of testing a marine cable by actually laying one. Newall v. Elliot, 4 C. B. (N. S.) 269.

himself till after the date of the patent (n). In these days of competition it would be advisable, in the public interest, to extend this doctrine, as is done in America. There are many inventions the value of which cannot be estimated till after some months' work on a manufacturing scale, and in such cases the inventor should be allowed to support letters patent obtained after such user for a limited period, provided that during that period none other than himself or his servants used the invention. Many inventors, through caution in thus testing their inventions, lose their reward; and if in this respect their position were altered, the public would be benefited by getting a more perfect description of the invention, and the entry of worthless patents on the register would be avoided. In this view there is nothing inconsistent with the statute of James. The manufacture is new, and others cannot rightly be said to use it, except where the patent is for an article which has been sold to or used by the public. This exception would not be very material in this case, for the necessity for a provision of this kind is most felt in connection with processes and combinations (o). A

(n) Morgan v. Seaward, 1 W. P. R. 194; Bentley v. Flemming, 1 C. & K. 587; re Adamson's patent, 6 De G. M. & G. 420. Newall v. Elliot shows when profit may be made during experiment, 4 C. B. (N. S.) 269. Bramah v. Hardcastle, 1 Webs. P. R. 44 note.

(0) In discussing this question Mr. Justice Erle said: “If

d

Secret manufac

ture.

Prior publi-
cation.
In books.

secret manufacture and sale by others would not vitiate letters patent, why then should the secret use of the invention by a first and true inventor? Baron Parke answers this question by showing that if this were allowed the patentee would obtain a monopoly for more than fourteen years (p). This undesirable result might be prevented by deducting from the term of letters patent the limited period allowed for secret use, in testing an invention commercially.

Prior publication, in printed books (g) or in specifications (), for the same reasons as prior

one party only had used the process, and had brought out the article for profit, and kept the method entirely secret, I am not prepared to say that then the patent would have been invalid." Heath v. Smith, 2 E. & B. 256. Contra, see judgments of Buller (J.), in Boulton v. Bull, 2 H. B. 463–470, and Dallas (J.), in Hill v. Thompson, 1 Webs. P. C. 244.

(p) Morgan v. Seaward, 2 M. & W. 544.

(q) Rex v. Arkwright, 1 Webs. P. R. 72; Morgan v. Seaward, 1 Webs. P. R. 140; Cornish v. Keene, 1 Webs. P. R. 507; Walton v. Potter, 1 Webs. P. R. 593; The Household Company v. Neilson, 1 Webs. P. R. 718 note; Lang v. Gisborne, 31 Beav. 133. Copies in the German language sent to the Patent Office and the library of the Institute of Civil Engineers, United Telephone Company v. Cox-Walker, 21 Ch. D. 720. Secus (when issue of book not sufficient for publication); Stead v. Williams, 2 Webs. P. R. 136; Stead v. Anderson, 2 Webs. P. R. 149; Book not entered in catalogue, Plimpton v. Spiller, 6 Ch. D. 425; Heurteloup's Patent, 1 Webs. P. R. 553. In fragments of books and annuals, Heyden v. Neustadt, 28 W. R. 496.

(r) As a general rule, Huddart v. Grimshaw, 1 Webs. P. R.