air blast; but that what he claims as his invention, is the application of anthracite or stone coal, and culm, combined with the using of hot-air blast in the smelting and manufacture of iron from iron stone, mine, or ore. And the question therefore becomes this— whether, admitting the using of the hot-air blast to have been known before in the manufacture of iron with bituminous coal, and the use of anthracite and stone coal to have been known before in the manufacture of iron with cold-blast; but that the combination of the two together (the hot-blast and the anthracite) were not known to be combined before in the manufacture of iron, whether such combination can be the subject of a patent? We are of opinion that if the result produced by such a combination, is either a new article, or a better article, or a cheaper article to the public, than that produced before by the old method, that such combination is an invention or manufacture intended by the statute, and may well become the subject of a patent. Such an assumed state of facts falls clearly within the principle exemplified by Abbot, Chief Justice, in the case of the King v. Wheeler, 2nd Barnewall and Adolphus, 349, where he is determining what is, or what is not, the subject of a patent: namely, it may perhaps extend to a new process, to be carried on by known instruments, or elements, acting upon known substances, and ultimately producing some other known substance, but producing it in a cheaper or more expeditious manner, or a better or more useful kind. And it falls also, within the doctrine laid down by Lord Eldon, in Hill v. Thompson, in 3rd Merivale, 629 namely, there may be a valid patent for a known combination of materials previously in use for the same purpose, or even for a new method of applying such materials; but the specification must clearly express that it is in respect of such new combination or application. There are numerous instances of patents which have been granted where the invention consisted in no more than in the use of things already known, and acting with them in a manner already known, and producing effects already known; but producing those effects so as to be more economically or beneficially enjoyed by the public. It will be sufficient to refer to a few instances, some of which patents have failed on other grounds, but none on the ground that the invention itself was not the subject of a patent. We may first instance Hall's patent for applying the flame of gas to singe off the superfluous fibres of lace, when a flame of oil had been used before for the same purpose; Derosne's patent, in which the invention consisted in filtering the syrup of sugar through a filter, to act with animal charcoal, and charcoal from bituminous schistus, where charcoal had been used before in the filtering of almost every other liquor, except the syrup of sugar; Hill's patent, in 3rd Merivale above refered to, for improvements in the smelting and working of iron; there the invention consisted only in the use and application of the slags or cinders, thrown off by the operation of smelting, which had been previously considered useless, for the production of good and serviceable metal, by the admixture of mine

rubbish. Again, Daniel's patent was taken out for improvements in dressing woollen cloth, where the invention consisted in immersing a roll of cloth, manufactured in the usual manner, in hot water. (See the King v. Daniel, in Mr. Godson's book on patents, 274.) The only question, therefore, that ought to be considered on the evidence, is—was the iron produced by the combination of the hotblast and the anthracite a better or a cheaper article than was produced from the combination of the hot-blast and the bituminous coal; and was the combination described in the specification new, as to the public use thereof, in England? And upon the first point, upon looking at the evidence in the cause, we think there is no doubt that the result of the combination of the hot-blast with the anthracite, on the yield of the furnaces, was more; the nature, property, and quality of the iron better; and the expense of making the iron less, than it was under the former process, by means of the combination of the hot-blast with the bituminous coal. It is to be observed, that no evidence was produced on the part of the defendants to meet that given by the plaintiff on these grounds, and that it was a necessary consequence, from the proof in the cause, that the substitution of the anthracite coal, in whole, or in part, instead of or in the place of, bituminous coal, from the substitution of that the manufacture of the iron should be obtained at less expense. It was objected, in the course of the argument, that the quality, or degree, of invention, was so small that it could not become the subject-matter of a patent; that a person who could procure a license to use the hot-air blast under Neilson's patent had a full right to apply that blast to coal of any nature whatevever, whether bituminous or stone coal. But we think if it were necessary to consider the labour, pains, expense, incurred by the plaintiff in bringing his discovery to perfection, that there is evidence in this cause that the expense was considerable, and the experiments numerous. But in point of law, the labour of thought, or experiments, and the expenditure of money, are not the essential grounds of consideration on which the question, whether the invention is or is not the subject-matter of a patent, ought to depend; for if the invention be new and useful to the public, it is not material whether it be the research of long experiments and profound research, or whether by some sudden and lucky thought or mere accidental discovery. The case of Monopolies, 11th Coke, states the law to be, that where a man, by his own charge or industry, or by his own wit or invention, brings a new trade into the realm, or any engine tending to the furtherance of a trade, that never was used before, and that was for the good of the realm, that the King may grant him the monopoly of a patent for a reasonable time. If the combination now under consideration be, as we think it is, a manufacture within the statute of James the First, there was abundant evidence in the cause that it had been the great object and desideratum, before the granting of the patent, to smelt iron stone by the means of anthracite coal, and that it had never been done before. There is no evidence on the part of the

defendants, to meet that which the plaintiff brought forward. These considerations, therefore, enable us to direct that the verdict ought to be entered for the plaintiff, on the third issue; that it was a new manufacture-new as to the public use and exercise thereof, within England and Wales. On the same ground, also, the second issue is disposed of in favour of the plaintiff. No evidence was produced on the part of the defendants, to show any inventor earlier than the plaintiff; nor does the fact that there was an earlier inventor appear from the cross-examination of the plaintiff's witnesses. As to the first issue-namely, whether the defendants had infringed the patent, we think it clearly appears on the evidence, that the defendants had used, either in part or in whole, the combination described in the specification of the plaintiff's patent; the plaiutiff's evidence goes fully to show certain infringements, and that is not met by any explanations on the part of the defendants. Indeed, the defendants' case did not appear to rest on this point at the trial, so much as on the important question raised by them, whether the improvement described in the specification was a manufacture within the statute of James. Upon the fourth issue, which raised no more than the usual inquiry-whether the nature of the invention was sufficiently described in the specification?-the usual evidence was given that persons of competent skill and experience could, by following the direction, produce the manufacture described, with success; and this evidence was entirely unopposed. Upon this issue, also, the verdict ought to be entered for the plaintiff. With respect, however, to the issue raised in the rejoinder, in the plaintiff's replication to the fifth plea, we are of opinion, that taking the whole evidence brought forward by the plaintiff, it is impossible to perceive any substantial or real distinction between the hot-air blast, and the machinery and apparatus described in Neilson's specification, from that described or referred to in the plaintiff's; or to say that the using by the plaintiff of the invention described in his specification, was any other than a using and imitating of the invention described in Neilson's specification. The plaintiff, indeed, worked by license under Neilson's patent, at the time of his discovery. On this fifth issue, therefore, we think the verdict should be entered for the defendants. Then arises the question whether the plaintiff is or is not entitled to the judgment, notwithstanding the verdict on the fifth issue, on which point the argument on the part of the defendants is, that the taking out a patent for an invention, which invention cannot be used or enjoyed by the public except by means of the former invention of another person, which former invention is itself the subject-matter of a patent still in force, is void by law. Undoubtedly, if the second patent claims, as part of the invention described in it, that which had been the subject-matter of a patent then in force, it would be void, on the double ground that it claimed that which was not new (which, indeed, would equally be the case if the former patent had expired), and also that it would be an infringement of, and inconsistent with, a former grant of the King, still in force; which

latter consideration, alone, would make a new grant void. But in this case, there is an express disclaimer of any part of the invention to the use of the hot-air blast which was covered by Neilson's patent, the specification describing that the application of the hot-air blast was well understood, and extensively applied, in many places where ordinary fuel is employed. The validity, therefore, of the plaintiff's patent cannot be impeached on either of the grounds above adverted to. Unless, therefore, the grantee of the new letters patent is bound by law to specify whether such former invention, which is excepted, was so excepted on the ground of its being generally known and used by the public, and on the ground that it was the subject of a patent that secured the use of it to a former patentee, the new patent will be good; but that distinction is as much in the knowledge of the public as the grantee of the patent. If, indeed the new patent had been taken out for improvement, or alterations, in an invention secured by a former patent, then, for obvious reasous, greater particularity would be necessary to distinguish the new from the old. But the present specification expressly says "I take the whole of the invention, already well known to the public, and I combine it with something else." Now, it is further argued, that in point of law no patent can be taken out which includes the subject-matter of a patent still remaining, or in force. No authority was cited to support this proposition; and the case which was before Lord Tenterden, and in which he held that where an action was brought for improvements in a former patent granted to another person, and still in force, that the plaintiff must produce the former patent and specification; that at least affords a strong inference that the second patent was good. Lewis v. Davis 3rd Carrington, and Payne and Harmer v. Payne, 11th East., are clear authorities on the same point; and upon reason and principle there appears to be no objection. The new patent, after the expiraation of the old one, will be free from every objection; and whilst the former exists, the new patent can be legally used by the public by procuring a license from Neilson, or by purchasing the apparatus from him or some of his agents; and the probability of the refusal of a license to any one applying for it is so extremely remote that it cannot enter into consideration as a ground of legal objection. On the whole, therefore, we think the verdict is to be entered for the plaintiff on all the issues except the fifth; that the verdict is to be entered for the defendants on the fifth issue-but that, notwithstanding such verdict, the judgment must be given for the plaintiff.

Mr. M. Smith :-My Lord, there are certain certificates which were to be given, in case the judgment was for the plaintiff.

The Lord Chief Justice :-You must apply to me for those; that is not a matter for the Court-that is a matter for myself.

A dangerous Property of Wood Ashes exposed, and some of their other Properties examined. By Dr. JOHN T. PLUMMER, of Richmond, Indiana.*

I HAVE recently devoted some time to a further examination into the properties of wood ashes, and especially into that property by which heat is conveyed from a small space on their surface deeply into the interior of the largest masses. I consider the subject of sufficient importance to claim the attention of the general as well as the scientific reader; for I cannot forbear thinking, that at least some of the mysterious conflagrations which are repeatedly occurring, are chargeable to this hitherto unsuspected cause.

Judging by the remarks of Prof. Hubbard, accompanying two cases of combustion in wood ashes, reported by him in a late number of this journal, it appears to be his opinion that the caloric in question was generated within and near the bottom of the heap, by a spontaneous but unknown process. I conceive that the following experiments render this opinion highly improbable, and they go to sustain the view taken by the present writer, so far as it respects the origin of the caloric, and perhaps measurably as it regards the means by which the heat is diffused throughout the ashes. They show that the heat-retaining power is not peculiar to ashes, but is common to various pulverulent substances; that this residue of combustion contains an appreciable quantity of charcoal in a state of minute division; and, as formerly stated, that it is unsafe to deposit hot ashes upon, perhaps, the largest heaps of cold ashes. I shall marshal these experiments under the head of―

Ignitibility of Wood Ashes.-1. A pint of sifted ashes was made into a conical heap four inches high, upon a folded newspaper, and a coal lighted at one corner only, was laid upon the summit and very slightly covered. In seventeen minutes the coal was examined and found to be wholly ignited. It was again covered, and in eleven minutes afterward that part of the paper on which the ashes rested became quite warm, and also the board beneath it. On sliding the paper nearly off the board, and gently bending it convexly upwards, I succeeded in producing a fissure, extending from the apex of the cone downward to a considerable depth. By this means I was enabled to see the interior of my diminutive volcano, and to discover that the ashes within were red hot, if not incandescent, as far down as the fissure extended. After this peep, I closed up the crater by sliding the paper back upon the board, and waited an hour from the beginning of the experiment. At the expiration of this period, the coal was not wholly consumed, and the ashes were still quite warm.

The coal used in the foregoing instance was of sugar-tree wood, and at the time it was placed upon the ashes, two other coals, one of

From "The American Journal of Science and Arts."