lected to seize, would expose himself to an action for damages, unless some statute of the United States should contain a clear exception. No such express exception can be found; and it is inferred to exist only by supposing that the officer would, by the sale, make himself a wrongdoer, within the clause of the statute above recited. But within the very words of that clause, it would be no offence to seize the machine in execution. The whole offence must consist in a sale. It would therefore follow, that the officer might lawfully seize; and if so, it would be somewhat strange, if he could not proceed to do those acts which alone, by law, could make his seizure effectual. In the present case, we think that a sale of a patented machine, within the prohibitions of the same clause, must be a sale, not of the materials of a machine, either separate or combined, but of a complete machine, with the right, express or implied, of using the same in the manner secured by the patent. It must be a tortious sale, not for the purpose merely of depriving the owner of the materials, but of the use and benefit of his patent." "There is no pretence, in the case before us, that the officer had either sold or guaranteed a right to use the machine in the manner pointed out in the patent right. He sold the materials as such, to be applied by the purchaser as he should by law have a right to apply them. The purchaser must, there fore, act at his own peril, but in no respect can the officer be responsible for his conduct."""" CHAPTER XVII. Infringement. Sec. 1. Definition in the Law. Devising. 2. Making. 3. Using. 4. Selling. 5. Identity of Thing Used or Sold, and that Patented. Difference in Form and Proportions merely. Infringement of a Combinationof a Part. Sec. I.-DEFINITION IN THE LAW. DEVISING. THOUGH HOUGH an inventor, having a right to take out a patent, may assign such patent before taking it out, so that the assignment may operate on the patent when taken out, yet he has not such a property as can be the subject of an infringement.' The fifth section of the act of 1793, which section 17 Sawin v. Guild, 1 Gallison, 495. was repealed in 1800, described it to be an infringement to "make, devise, and use, or sell" the thing invented. There was some ambiguity in this description, which was cleared up in the fourth section of the act of 1800, in which it was provided that, “where any person, without the consent of the patentee, his or her executors, &c. first obtained in writing, should make, devise, use or sell the thing whereof the exclusive right was secured to the patentee by patent, such person so offending should forfeit," &c. The act of 1836, by which all the preceding acts have been repealed, gives no description of what shall be an infringement, otherwise than by providing for damages in case of "making, using or selling the thing patented, nor is any such description necessary, since the patent itself, in the form prescribed by that act, in terms grants to the applicant, "for a term not exceeding fourteen years, the full and exclusive right and liberty of making, using, and vending to others to be used, the invention or discovery.' The form of the patent, under the former law, granted to the patentee the exclusive right of "making, constructing, using and vending to others to be used." The change made by the law of 1836 is in dropping the word constructing, which was immaterial, since its meaning is comprehended in making. And so the omission of the word devising, which was used in the act of 1793, in describing an infringement, is unquestionably an improvement, on account of its ambiguity; and because the only practical meaning that could be given it is comprehended in the word making. Sec. II.-MAKING. It has been held by Mr. Justice Story, that the making of a patented machine for use or sale, though it were, in fact, neither used nor sold, is an infringement, for which, however, only nominal damages can be recovered, but that the making merely for experiment or philosophical purposes is not an infringement.' Sec. III.-USING. A use of the patented article is a direct and unquestionable infringement. We are here speaking of the use of the thing itself, which is the subject of the patent, not that of its products. A patent is, as has been explained in its place, an exclusive right to the practice or use of a certain art, process, contrivance or principle, combined with, and embodied in, material substances. The art, contrivance or design, * Whittemore v. Cutter, 1 Gall. R. 429. considered abstractly, is not itself patentable, or an infringement of a patent. It is only in its production, in combination with materials, that it is either patentable itself, or a violation of a patent right. In a patented instrument or piece of machinery, the subject of the patent exists, and is visible and tangible, and admits of being possessed and delivered distinctly, and independently of its products. But when a composition of matter is the thing patented, the subject of the patent is identified with its products,or rather a specimen of the product, or the only vendible thing which it is the object of the invention to supply, is, at the same time, a specimen of the invention itself. Whereas, in the case of an instrument or machine, one object of the invention is to produce the instrument or machine itself, another to produce its products. The inventor of a loom may propose a profit on the sale of it, as well as on the sale of its products. So, again, a steam engine, like a loom, is invented to be used as an instrument until it is worn out; and, in this respect, both differ from a patent medicine or many chemical compositions, which are consumed and destroyed at once in the use. Now, considering the use of the thing patented to be an infringement of the patent right, is there any difference in this respect between these different kinds of articles? Is it equally an infringement to use a patented medicine, which is destroyed in the use, or a |