one in which he claimed those parts which have been before known, his patent was void.65

Sec. XI.-IMPROVEMENT.

The act of Congress of July 4, 1836, c. 357, s. 6. following that of Feb. 21, 1793, c. 55, s. 1, provides that "any person having discovered or invented any new and useful improvement on any art, machine, manufacture or composition of matter," may apply for a patent. The French, Belgian, Austrian, and Spanish laws, are similar in this respect. They merely adopt the construction which had before been put upon the statute of monopolies by the English courts. Lord Coke mentions an early case against this construction. He says, "If the substance was in esse before, and a new addition thereunto, though that addition made the former more profitable, yet it is not a new manufacture in law; and so it was resolved in the Exchequer Chamber, Pasch. 15 Eliz. in Bircot's case, for a privilege concerning the preparing and melting, &c. of lead ore; for there it was said, that that was to put

65 Stanley v. Hewitt, Cir. C. of U. S. Eastern Dist. of N. Y. 1835. Journal of the Franklin Institute, v. 17, p. 165. No. for March, 1836.

but a new button to an old coat; and it is much easier to add than to invent. And there it was also resolved, that if the new manufacture be substantially invented according to law, yet no old manufacture in use before can be prohibited." But the doctrine of Bircot's case was early abandoned. Mr. Justice Buller says that, "In Morris v. Branson, tried at the sittings after Easter term, 1776, the patent was for making eyelet-holes or net-work in silk, thread, cotton or worsted; and the defendant objected that it was not a new invention, it being only an addition to the stocking-frame. Lord Mansfield said, "after one of the former trials on this patent, I received a very sensible letter from one of the gentlemen who was upon the jury, on the subject whether, on principles of public policy, there could be a patent for an addition only. I paid great attention to it, and mentioned it to all the judges. If the general point in law, viz. that there can be no patent for an addition, be with the defendant, that is open upon the record, and he may move in arrest of judgment. But that objection would go to repeal almost every patent that was ever granted." There was a verdict for the plaintiff, with 5007. damages, and no motion was made in arrest of

663 Inst. 184.

judgment. Though his Lordship did not mention what were the opinions of the judges, or give any direct opinion himself, yet we may safely collect that he thought on great consideration, the patent was good, and the defendant's counsel, though they had made the objection at the trial, did not afterwards persist in it.67

Mr. Justice Grose makes a similar remark upon the same case. He says, "A doubt is entertained whether there can be a patent for an addition to an old manufacture. This doubt rests altogether upon Bircot's case, 3 Inst. 184; and if that were to be considered as law at this day, it would set aside many patents for very ingenious inventions, in cases where the additions to manufactures before existing, are much more valuable than the original manufactures themselves. If indeed a patent could not be granted for an addition, it would be depriving the public of one of the best benefits of the statute of James. Lord Coke's opinion seems to have been formed without due consideration, and modern experience shows that it is not well founded. And so Mr. Justice Eyre says Bircot's case is not law."9

67 2 H. Bl. 489.

68 8 T. R. 104.

68

69 Boulton v. Bull, 2 H. Bl. 491.

69

The cases on Watt's patent brought this question directly before the courts, for his invention was professedly an improvement on the steam-engine. In one of those cases which came before the Exchequer Chamber in 1795, Mr. Justice Buller said, "that a patent for an addition or improvement may be maintained, is a point which has never been directly decided; and Bircot's case, 3 Inst. 184, is an express authority against it, which case was decided in the Exchequer Chamber. What were the particular facts of that case we are not informed, and there seems to me to be more quaintness than solidity in the reason assigned, which is, that it was to put but a new button to an old coat, and it is much easier to add than to invent. If the button were new, I do not feel the weight of the objection, that the coat, on which the button was to be put, was old. But in truth arts and sciences at that period were at so low an ebb, in comparison with that point to which they have been since advanced, and the effect and utility of improvements so little known, that I do not think that case ought to preclude the question. In later times whenever the point has arisen, the inclination of the court has been in favor of the patent for the improvement, and the parties have acquiesced, where the objection

might have been brought directly before the court.""""

The preceding cases have been cited rather to show the course of the jurisprudence on this subject, and the grounds on which an addition or improvement was held to be patentable under the English statute of monopolies, than for the purpose of establishing the point that it is so, of which there can be no doubt, since, as we have seen, the act of Congress expressly recognises the right to such a patent.

In regard to improvements, two material questions arise: 1. Whether a thing is new, or the improvement merely of what was known before; and 2. Where the alleged invention is described to be an improvement merely, whether it is a substantial material improvement, or only a change in form.

On the first of these questions Mr. Justice Story says, "it is difficult to define the exact cases, when the whole machine may be deemed a new invention, and when only an improvement of an old machine; the cases often approach very near to each other. In the present improved state of machinery, it is almost impracticable not to employ the same elements of motion, and in some particulars, the same manner

70 2 H. Bl. 489.