principle so far embodied and connected with corporeal substances, as to be in a condition to act and to produce effects. in any art, trade, mystery, or manual occupation, becomes the practical manner of doing a particular thing. It is no longer a principle, but a process.1 Mr. Watt's invention was the discovery of a practical means of lessening the consumption of steam, by protecting the cylinder from the external air, and keeping it at a temperature not below that of steam itself. He thus brought a principle into practical application, by the invention of a process.

§ 73. In like manner, a patent for the application of the flame of gas, instead of the flame of oil, to remove the superfluous fibres of lace, was sustained.2 So, too, where the invention consisted in the use and application of lime and mine-rubbish in the smelting of iron, Lord Eldon said there might be a patent for a new combination of materials previously in use for the same purpose, or for a new method of applying such materials.3 But this distinction has been made still more prominent by two recent cases. In one, the patent was for the application of anthracite, combined with hot-air blast, in the smelting or manufacture of iron from iron stone, mine, or ore; and the patent was sustained. In the other, the invention was of a mode of welding iron tubes, without the use of a maundril, or any internal support; and this patent was also sustained.5

§74. These cases show that the term manufacture has been extended to include every object upon which art or skill

1 See the remarks of Eyre, C. J., ante.

2 Hall v. Jervis, Webs. Pat. Cas. 100.

3 Hill v. Thompson, 3 Mer. 626. Webs. Pat. Cas. 237. In Morgan v. Seaward, 2 Mees. & W. 544, Mr. Baron Parke said: "The word manu

facture, in the statute, must be construed one of two ways; it may mean the machine when completed, or the mode of constructing the machine.

4 Crane v. Price, Webs. Pat. Cas. 393, 408.

5 Russell v. Cowley, Webs. Pat. Cas. 459.

can be exercised, so as to afford products fabricated by the hand of man, or by the labor which he directs.1 In this sense it includes a process; so that a patent may, it is said, be taken for a process, method, or practical application of a principle, that will cover every means or apparatus by which that process or method can be carried on, or by which that principle can be applied, provided the patentee has not only discovered the principle, but has also invented some mode of carrying it into effect.2

§ 74 a. But it is necessary here to consider the broad question, what constitutes a patentable subject, before we attend to the classification of patentable subjects adopted by our statute.

§ 75. It is constantly to be borne in mind, in considering what may be the subject of a valid patent, that it cannot be a mere elementary principle, or intellectual discovery; but if a principle constitutes an important part of the discovery, it must be a principle put in practice and applied to some art.3 A science, therefore, or an elementary principle or discovery in science, cannot be the subject of a patent. So, too, there cannot be a patent for an effect, but it must be for the mode or means by which the effect is produced; or the practical mode of operating, by means of certain agencies or properties of matter, or laws of physics, so as to produce a given effect.

1 Webster's Law and Practice, Supplement, p. 8.

2 Forsyth v. Riviere, Webs. Pat. Cas. 97, note. Per Alderson, B., in Jupe v. Pratt, Ibid. 146, and in Nielson v. Hartford, Ibid. 342.

3 Earl v. Sawyer, 4 Mass. 1-6. "The very statement of what a principle is, proves it not to be a ground for a patent. It is the first ground and rule for arts and sciences, or, in other words, the elements and rudiments of them. A patent must be for some new production from those elements, and not for the elements themselves." Per Buller, J., in Boulton v. Bull, 2 H. Bl. 485.

4 Whittemore v. Cutter, 1 Gallis. 478, 480.

§ 76. The consequences of allowing a patent for an abstract art or a principle, instead of allowing it only for a principle as applied to the production of a particular thing, or a particular result in matter, are apparent, when it is considered that principles are the elements of science; and if a a patent could be taken for a newly discovered principle in science, it would cover every object to which that principle could be applied, and the whole field of the arts would thus at once be occupied by a few monopolists. If a patent for an art or method of combining different elements or principles in science were possible, without its being confined to a particular product or result by means of such an art or method, every product, substance, or manufacture, to the creation of which that art or method could be applied, would be included in it. Thus it has been happily pointed out by an eminent English judge that if a man could have a patent for the principle or abstract art of intermixing water with oil colors, no other man could have had a patent for any distinct manufacture produced on the same principle.2 The distinction is this if a discovery consists merely in detecting some new property of matter, or of the elements of nature, or the laws of physics, but no special and positive application is made of it to specific fabrications, it is a discovery in science, or ab

1 "Indeed it seems impossible to specify a principle, and its application to all cases, which furnishes an argument that it cannot be the subject of a a patent." Per Heath, J., in Boulton v. Bull, 2 H. Bl. 483.

2 The case of water tabbies, which has often been mentioned in Westminster Hall, may afford some illustration of this subject. That invention first owed its rise to the accident of a man's spitting on a floor cloth, which changed its color, from whence he reasoned on the effect of intermixing water with oils or colors, and found out how to make water tabbies and had his patent for water tabbies only. But if he could have had a patent for the principle of intermixing water with oil or colors, no man could have had a patent for any distinct manufacture produced on the same principle, yet as the floor cloth and the tabby are distinct substances, calculated for distinct purposes, and were unknown to the world before, a patent for one would be no objection to a patent for another." Per Buller, J., in Boulton v. Bull, 2 H. Bl. 487.

stract mechanics, and not patentable; but if the discoverer makes use of such a new property, or avails himself of scientific or mechanical principles, for the production of a new substance, instrument or machine, obtaining a result that is new, and of a vendible description, the particular mode of producing that particular thing may be the subject of a patent.1 This distinction has been previously noticed; but it is necessary here to examine the doctrine, and to ascertain to what objects the distinction has been applied, and what seem to be its necessary limits.

§ 77. We have already seen that the term "manufacture" being the only generic term used in the Statute of Monopolies to describe the subjects of lawful patents, it became necessary to enlarge it by construction much beyond its literal import. As soon as it was held that a patent could be taken

1 A striking illustration of this distinction occurred before Mr. Justice Story. The plaintiff's specification claimed "as new, to cut ice, of a uniform size, by means of an apparatus worked by any other power than human. The invention of this art, as well as the particular method of the application of the principle, are claimed by the subscriber." The learned judge said "it is plain, then, that here the patentee claims a title to the art of cutting ice by means of any power other than human power. Such a claim is surely unmaintainable in point of law. It is a claim for an art or principle in the abstract, and not for any particular method or machinery by which ice is to be cut. No man can have a right to cut ice by all means or methods, or by all or any sort of apparatus, although he is not the inventor of any or all of such means, methods, or apparatus." Wyeth v. Stone, 1 Story's R. 273, 285. But the court intimated that the claim for the particular method of the application of the principle would have been good, if a disclaimer had been filed in season as to that part of the claim which was clearly bad. Ibid.

See also Stone v. Sprague, 1 Story's R. 270, where in a patent for an improvement on looms, the invention claimed was the communication of motion from the reed to the yarn beam, in the connection of the one with the other, which is produced as follows, describing the mode, it was held, that the invention was limited to the specific machinery and mode of communicating the motion, &c., specifically described in the specification; otherwise it would be a claim for the abstract principle of communicating motion in all possible modes.

for the mode of producing an effect, as in Watt's case, for the mode of lessening the consumption of steam in a steamengine, the literal meaning of this term was widely departed from, and that was held to be a "manufacture" within the meaning of the statute, which in reality consisted in the new application of certain principles of physics, to effect the more economical use of a well-known machine. This, of necessity, opened the whole subject of principle and method, and led to the doctrine which we are now to state.

§ 78. Although a patent cannot be taken out for a new principle, yet, where it has been embodied, so as to be capable of being made active, it is, as we have seen, a proper subject of a patent; and if any other person puts that principle into use, in any other form, it is a question for a jury, whether that form be not substantially an adaptation of the principle, applied with the same view to answer the same end, and merely imitated in substance, whatever difference there may be in point of form. If the patentee has invented some mode of carrying the principle into effect, he is entitled, it is said, to protect himself from all other modes of carrying the same principle into effect. In point of fact, the patent in such cases is taken, not for the principle itself but for the mode of carrying into effect;2 so that when it is alleged that

1 In Jupe v. Pratt, Webs. Pat. Cas. 144, 146, Alderson, B., said, "The difficulty which will press on you, and to which your attention will be called, in the present case, is this: you can take out a patent for a principle coupled with the mode of carrying the principle into effect, provided you have not only discovered the principle, but invented some mode of carrying it into effect. But then you must start with having invented some mode of carrying the principle into effect; if you have done that, then you are entitled to protect yourself from all other modes of carrying the same principle into effect, that being treated by the jury as a piracy of your original invention. But then the difficulty that will press on you here is, that on the evidence, there does not appear to have been any mode of carrying the principle into effect at all invented by you."

2 See Hill v. Thompson, Webs. Pat. Cas. 227; 3 Meriv. 626.