damages to the other party for what he had lost." The common law, with more policy and justice, to guard against fraud, gave the entire property, without any account, to him whose property was originally invaded, and its distinct character destroyed. If A. will wilfully intermix his corn or hay with that of B., or casts his gold into another's crucible, so that it becomes impossible to distinguish what belonged to A. from what belonged to B., the whole belongs to B. But this rule is carried no farther than necessity requires; and if the goods can be easily distinguished and separated, as articles of furniture for instance, then no change of property takes place. So, if the corn or flour mixed together were of equal value, then the injured party takes his given quantity, and not the whole. This is Lord Eldon's construction of the cases in the old law. But if the articles were of different value or quantity, and the original value not to be distinguished, the party injured takes the whole. It is for the party guilty of the fraud to distinguish his own property satisfactorily, or lose it. No court of justice is bound to make the discrimination for him.J

III. Of original acquisition, by intellectual labour.

Another instance of property acquired by one's own act and power, is that of literary property, consisting of maps, charts, writings, and books; and of mechanical inventions, consisting of useful machines or discoveries, produced by the joint result of intellectual and manua! labour. As long as these are kept within the possession of the author, he has the same right to the exclusive enjoyment of them, as of any other species of personal property; for they have proprie

a Inst. 2. 1. 26 and 28.

b Popham, 38. pl. 2.

c Pop. ub. sup. Ward v. Eyre, 2 Bulst. 323,

d Colwill v. Reeves, 2 Campbell's N. P. 575.

e 15 Vesey, 442.

f 2 Johns. Ch Rep. 108. Hart v. Ten Eyck. Sir William Scott, in the case of The Odin, 1 Rob. Rep. 208.

tary marks, and are a distinguishable subject of property. But when they are circulated abroad, and published with the author's consent, they become common property, and subject to the free use of the community. It has been found necessary, however, for the promotion of the useful arts, and the encouragement of learning, that ingenious men should be stimulated to the most active exertion of the powers of genius, in the production of works useful to the country, and instructive to mankind, by the hope of profit, as well as by the love of fame, or a sense of duty. It is just that they should enjoy the pecuniary profits resulting from mental as well as bodily labour. We have, accordingly, in imitation of the English jurisprudence, secured by law to authors and inventors, for a limited time, the right to the exclusive use and profit of their productions and discoveries. The jurisdiction of this subject is vested in the government of the United States, by that part of the constitution, which declares," that Congress shall have power "to promote the progress of science and useful arts, by securing, for limited times, to authors and inventors, the exclusive right to their respective writings and discoveries." This power was very properly confided to Congress, for the states could not separately make effectual provision for the case.

(1.) As to patent rights for inventions.

Any person being a citizen of the United States, and any alien, who, at the time of his application, shall have resided for two years within the United States, and who hath invented any new and useful art, machine, manufacture, or composition of matter, or any new and useful improvement on the same, not known or used before the application, may apply to the secretary of state, for a pátent, for the exclusive right of making, constructing, using, and vending, for fourteen years, his invention or discovery. The applicant must make oath, or affirmation,

a Art. 1. sect. 8.

that he believes he is a true inventor or discoverer of the art, machine, or improvement, and he must give a written description of his invention, and of the manner of using, or process of compounding the same, in full, clear, exact, and intelligible terms, and accompany it with drawings, and references, and specimens, and models, according to the nature of the case, and cause the same to be attested and filed in the secretary's office. In the case of the application for a patent, by a resident alien, he must make oath, that the invention, art, or discovery, has not, to his knowledge or belief, been known or used in this or in any other country. The legal representatives and devisees of a person entitled to a patent, and who dies before it is obtained, may procure it, on complying with the general requisitions of the law. Any person who shall have discovered an improvement in the principle of any machine, or in the process of any composition of matter, may obtain a patent for such improvement; but he cannot thereby make, use, or vend the original discovery, nor can the first inventor use his improvement. Simply changing the form, or the proportions of any machine or composition of matter, in any degree, is declared not to be a discovery. If the specification does not contain the whole truth relative to the discovery, or contains more than was requisite to produce the described effect, and the concealment or addition was made for the purpose of deception; or if the thing secured by the patent was not originally discovered by the patentee, or had been in use, or described in some public work, anterior to the supposed discovery, or the patent was surreptitiously obtained for the discovery of another person ;-in either of those cases, the patent cannot be supported, and may be declared void.a

These are the principal statute provisions on the subject,

a Acts of Congress, 21st Feb. 1793, ch. 11th, and 17th April, 1800, Ch. 25.

and, under their protection, upwards of four thousand patents have been sued out, and upwards of two thousand ingenious models in the mechanic arts, and relating to every subject connected with domestic and rural economy, manufactures and commerce, have been deposited in the office of the Secretary of State at Washington. In an age distinguished for an active and ardent spirit of improvement in the arts of agriculture and manufactures, and in the machinery of every kind applied to their use, the doctrine of patent rights has attracted much discussion, and become a subject of deep interest, both here and in Europe."

The courts of the United States have exclusive jurisdiction over these rights; and it has been adjudged by them, that the first inventor, who has reduced his invention first howto practice, and put it to some real and beneficial use, ever limited in extent, is entitled to a priority of the patent right, and a subsequent inventor cannot sustain his claim, although he be an original inventor, and has obtained the first patent. The law, in such case, cannot give the whole patent right to each inventor, even if each be equally entitled to the merit of being an original and independent inventor; and it, therefore adopts the maxim, qui prior est in tempore, potior est in jure. If the patentee be not the first inventor he is not entitled to a patent, even thongh he had no knowledge of the previous use, or previous description of the invention, for the law presumes he may have known

a Patents are no doubt procured in many cases for frivolous and useless alterations in articles, implements, and machines in common use, under the name of improvements; and the abuses arising from the facility in suing out patents, and provoking litigation, were painted in glowing colours by the district judge at New-York, in Thompson v. Haight; (U. S. Law Journal, vol. i. 563.) and yet the collection of models and machines in the patent office relating to every possible subject, constitutes a singularly curious museum of the arts, and one strongly illustrative of the inventive and enterprising genius of our countrymen.

it. If the first inventor has suffered his invention to go into general use, without taking out a patent, the better opinion, and the weight of authority, is, that he cannot af terwards resume the invention, and hold a patent. It would be unreasonable and injurious, for a person to be permitted to lie by for years, and suffer his invention or improvement to go into use, and expensive undertakings to be assumed, and machinery constructed for the application of that invention, and then sue out a patent, and ar rest all such proceedings. The just inference from such delay is, that he has made an abandonment, or present of his discovery, to the public; and the only limitation to this conclusion is in the case, when it shall be made satisfactorily to appear, as a matter of fact, that the delay was merely with the intention to improve the invention by experiments and practice, before applying for a patent. It has been a point of sume discussion and difficulty, to determine to what extent an invention must be useful to render it the subject of a patent. This will, as a matter of fact, depend upon the circumstances of each case. It must be to a certain degree beneficial to the community, and not injurious, or frivolous, or insignificant.c

The act of Congress has described, in substance, the requisite parts of a valid specification of the discovery ; and yet the defects of the specification is one great source of a vexatious and perplexing litigation in our own, as well as in the English courts. In the present improved state of the arts, it is often a question of intrinsic difficulty, especially in cases of the invention of minute additions to com

a Woodcock v. Parker, 1 Gallis. 438. Bedford v. Hunt, Mason, 302. Evans v. Eaton, 3 Wheaton, 454.

b Whittemore v. Cutter, 1 Gallis. 478. Thompson v. Haight, U. S. L. Journal, vol. i. 563. Morris v. Huntington, 1 Paine, 343. Contra, Goodyear v. Mathews, 1 Paine, 300.

c Lowell v. Lewis, 1 Mason, 182. Langdon v. De Groot, 1 Paine, 203.