The language of the statute in the passage above quoted, in which it describes the things for which a patent may be granted, is much the same as in the older statutes. And every word of it has passed repeatedly under adjudication.

The invention must be "new." But it is obviously impossible here, as indeed in most of the questions arising under our patent laws, to find precise and technical rules which always answer the question. Our notes will show the adjudication on this question. (g) 1 the invention by the patentee himself, more than two years before his application for a patent, if made only for the purpose of trial and experiment, will not avoid the patent. Wyeth v. Stone, 1 Story, 273; Ryan v. Goodwin, 8 Sumn. 618; Whitney v. Emmett, Bald. 809; Shaw v. Cooper, 7 Pet 320. See in re Newall v. Elliott, 4 C. B. (n. s.) 269. It is said that an invention may be abandoned even after it has been patented. Adams v. Edwards, 1 Fish. 1; Bell v. Daniels, id. 872.

(g) A machine is said to be new in the sense of the patent law when its principles or mode of operation are different from any previously known. And "by the principles of a machine," says Judge

1 A patent is prima facie evidence of novelty and utility as against an infringer. Lehnbeuter v. Holthaus,U. S. 94. Where an inventor presented, with no obligation of secrecy, a pair of corset-steels to a lady friend, who used them for eleven years, it was held (Miller, J., dissenting), that he could claim no patent, as there had been a public use of the article. Egbert v. Lippman, 104 U. S. 333.

It must not be merely the application of an old invention * or means or method of operation to a new use. (h)

Story, "is not meant the original elementary principles of motion which philosophy and science have discovered, but the modus operandi, the peculiar manner or device for producing any given effect. If the same effects are produced by two machines by the same mode of operation, the principles of each are the same. If the same effects are produced, but by combinations of machinery operating substantially in a different manner, the principles are different." Whittemore v. Cutter, 1 Gall. 478; Barrett v. Hall, 1 Mass. 470; Foote v. Silsby, 1 Blatchf. 469; Roberts v. Ward, 4 McLean, 696; Pitts v. Wemble, 2 Fish. 20; Latta v. Shawk, 1 Fish. 466. "What constitutes form, and what principle," says Washington, J.," is often a nice question to decide. The safest guide to accuracy in making the distinction is, to ascertain what is the result to be obtained by the discovery; and whatever is essential to that object, independent of the mere form and proportions of the thing used for the purpose, may generally, if not universally, be considered as the principle of the invention." Treadwell v. Bladen, 4 Wash. 706. A mere change in the form, proportions, or material of an existing machine, will not constitute a new invention, unless a new effect is thereby produced. Winans v. Denmead, 16 How. 811; Lowell v. Lewis, 1 Mass. 100. Many v. Jagger, 1 Blatchf. 806; Dixon v. Mover, 4 Wash. 71; Davis v. Palmer, 2 Brock. 810. Hotchkiss v. Greenwood, 11 How. 248. Nor does the substitution of a mechanical equivalent constitute an invention. See note (x), infra.

When, however, the invention consists in a new combination of parts in the same machine, or for a combination of machines to produce a certain effect, in either case it is immaterial whether the elements of the combination are new or old. Buck v. Hermance, 1 Blatchf. 404; Barrett v. Hall, 1 Mass. 474; Le Roy v. Tatham, 22 How. 132; Hovey v. Stevens, 1 Wood. & M. 302; Many v. Sizer, 1 Fish. 327; Potter p. Holland, 1 Fish. 327. But where an old machine is improved by the addition of new elements, a patent is valid only for the improvements, and the claim must not cover the whole machine. Whitney v. Emmett, Bald. 314; Evans v. Eaton, 7 Wheat. 480; Whittemore v. Cutter, 1 Gall. 480; Moody v. Fiske, 2 Mass. 118. So, in a patent for a composition of matter, it is not necessary that every ingredient, or even that any one ingredient, should have been unused before, for the purpose specified, provided the combination be substantially new. Ryan v. Goodwin, 3 Sumn. 514.

(h) Thus, in Losh v. Hague, 1 Webst. Pat. Cas. 205, it was held, that the application to railway carriages of a kind of wheel previously in use on common carriages, would not support a patent. So in Howe v. Abbott, 2 Story, 190, where the patentee claimed as his invention a process of curling palm-leaf for mattresses, etc., and it appeared that horsehair had long been prepared for the same purpose by the same process. Story, J., said: "The application of an old process to manufacture an article to which it had never before been applied, is not a patentable invention. There must be some new process, or some new machinery, used to produce the result If the old spinning machine to spin flax were now first applied to spin cotton, no man could hold a patent to spin cotton in that mode; much less the right to spin cotton in all modes, although he had invented none. As, therefore, Smith has invented no new process or machinery, but has only applied to palm-leaf the old process and the old machinery used to curl hair, it does not strike me that the patent is maintainable. He who produces an old result by a new mode or process, is entitled to a patent for that mode or process. But he cannot have a patent for a result merely without using some new mode or process to produce it." " In order to escape the objection of a double use," says Mr. Curtis, " it is necessary that the new occasion or purpose, to which the use of a known thing is applied, should not merely be analogous to the former occasions or purposes to which the same thing has been applied. When, therefore, the principle is well known, or the application consists in the use of a known thing to produce a particular effect, the question will arise, whether the effect is of itself entirely new, or whether the occasion only upon which the particular effect is produced is new. If the occasion only is new, then the use to which the thing is applied is simply analogous to what it had been before. But if the effect itself is new, then there are no known analogous uses of the same thing, and the process may constitute such an art as will be the subject of a patent." See also, Ames v. Howard, 1 Sumn. 487; Bean v. Smallwood. 2 Story, 411; Hotchkiss v.