corrosion; because it is light and elastic, and because of its strength. This follows from the mere choice of aluminum, which resists corrosion, is light, elastic, and strong.

So the question is whether patentable subject-matter is presented in a bicycle-frame, as an article of manufacture, when cast of aluminum alloy in one piece, when other articles had before been cast of aluminum alloy in one piece and the same article had been cast in one piece in malleable iron.

Many cases have been considered in courts wherein the question of patentability turned upon the substitution of one material for another. In all of them the doctrine that the mere substitution of one material for another does not confer patentability is recognized, and the applicants do not question it. Something more must be found in the facts of a given case, and always the question is, how much more and what its nature? It is with a view of apprehending this additional something, and not because the general doctrine respecting the substitution of materials is in doubt, that the cases that have come before the courts are now examined. I will first refer to those cited by the applicants.

In the well-known case of Smith v. Dental Vulcanite Co., (C. D., 1877, 171; 11 O. G., 246; 93 U. S., 486,) the specification fully sets out the process by which the article was made, and the claim as stated is:

The plate of hard rubber or vul canite, or its equivalent, for holding artificial teeth, or teeth and gums, substantially as described.

The Court hold that the claim is not to a product alone separated from the process by which it is created, and say that—

the process detailed is thereby made as much a part of the invention as are the materials of which the product is composed, (p. 493.)

The process was new, and the patent therefore issued not merely for an article, but for an article made by a new and defined process. And in the later case of Goodyear Dental Vulcanite Co. v. Davis, (C. D., 1881, 131; 19 O. G., 543; 102 U. S., 222,) the Court held that the process was as much a part of the invention as the material of which it was composed and that the plate made of celluloid prepared by a different process, which could not be employed in the preparation of rubber, did not constitute an infringement of the patent.

Moreover, the invention was not for the mere plate, but for the teeth, gums, and plate constituting one piece only, the whole having inherent qualities superior to those of the analogous article theretofore made. In both these particulars the case before me differs from the article embraced in the Cummings patent. Here the process is not alleged to be new, and, whether new or old, is not incorporated into the claim for the article, nor is the article in any manner a combination of elements in the least comparable to teeth, gums, and plate in one piece.

In Hicks v. Kelsey (5 O. G., 94; 18 Wall., 670) the invention consisted in making the ordinary wooden wagon-reach in two parts and in

splicing said parts with metallic plates or castings, with such a curve in the metallic part as to allow the front wheels to pass under them. The patentee disclaims either the wooden or metallic continuous curved reach per se, and states that he was aware that such reaches had been used. In that case it was argued by counsel that it was not a mere substitution of a particular material for other material previously used in the same way, but in the production of a certain article by a certain described mechanical process, which, viewed as a whole, was new. It was claimed that the new material in the curve, with the new method of attachment at each end to the two wooden parts, with the new construction of the reach as a whole, with the new operation in consequence of the change, with the increased utility and beneficial results, made their article a patentable invention. There was no opposing counsel. The Court said:

The use of one material instead of another in constructing a known machine is, in most cases, so obviously a matter of mere mechanical judgment, and not of invention, that it cannot be called an invention, unless some new and useful result, an increase of efficiency, or a decided saving in the operation, is clearly attained. Some evidence was given to show that the wagon-reach of the plaintiff is a better reach, requiring less repair, and having greater solidity than the wooden reach. But it is not sufficient to bring the case out of the category of more or less excellence of construction. The machine is the same.

In Crane v. Price, it is true, the use of anthracite instead of bituminous coal with the hot-blast in smelting iron ore was held to be a good invention, inasmuch as it produced a better article of iron at a less expense. But that was a process of manufacture, and in such processes a different article replacing another article in the combination often produces different results. The latter case is more analogous to the cases of compositions of matter than it is to those of machinery; and in compositions of matter a different ingredient changes the identity of the compound, whereas an iron bar in place of a wooden one, and subserving the same purpose, does not change the identity of a machine.

Kneas v. Schuylkill Bank, (4 Wash., 9,) decided in 1820, which these applicants claim to be a case involving the substitution of materials, upon examination does not appear to be so. The claim was for a method of preventing counterfeiting by printing bank notes on both sides, either with letter-press or copper plate, or on one side with one and on the other side with the other. The defendants were claimed to have infringed this patent, and in their behalf it was urged that it did not print the backs of its bills with copper plate, but with steel plate. The evidence tended to show that the words "copper-plate printing" had come to be used to designate any kind of printing from plate, whether copper or steel or other, and whether the words had such meaning was the question which the learned judge left to the jury. The verdict was for the complainant, who recovered three cents damages. The charge of the court clearly indicated that no evidence had been furnished of what the complainant's actual losses were. The case therefore goes to show, taking the law and facts together, that printing bills on both sides with steel plate to prevent counterfeiting was the same method, in a patentable

sense, as printing them on both sides with copper plate or copper plate and letter-press, and that the former acts constituted an infringement of the rights of the owners of the patent. That case throws little light on this.

Many v. Sizer (1 Fish., 17) was an action upon a patent for a carwheel composed of double-curved plates, one convex outward and the other convex inward, of cast-iron, in one piece, integral with the hub and rim. The patent, however, was in terms for a mode of constructing, and the question was not distinctly raised whether it were invention to construct car-wheels in the mode specified in the patent or whether the car-wheel so constructed were, as an article of manufacture, patentable; but the case turned rather upon the question of infringement. This case was decided in 1849, and at that time the courts had not sua sponte dismissed any suit brought to restrain the infringement of Letters Patent where the device for which they were granted was not patentable, and such defense was not set up, a course now established in Brown v. Piper, (C. D., 1876, 464; 10 O. G., 417; 91 U. S., 37,) and afterward taken in Slawson v. Grand Street Railway Co., (C. D., 1883, 318; 24 O. G., 99; 107 U. S., 649.)

The case of the Celluloid Manufacturing Company v. Comstock & Cheney Company (C. D., 1886, 403; 36 O. G., 1356; 26 Fed. Rep., 360, 1886) is relied on, as to which counsel in that case rightly said that the invention did not consist in the simple substitution of celluloid for ivory. But the same patent was also before the Circuit Court for the District of Massachusetts, in the case of the Celluloid Manufacturing Company v. Tower, (26 Fed. Rep., 451,) in which Carpenter, Judge, held the patent invalid. It appears that the latter case was taken by appeal to the Supreme Court of the United States, but was dismissed January 30, 1890, (136 U. S., 633,) for want of compliance with Rule 10. It should be stated, however, that the case before Judge Shipman was thought to rest upon different facts from the Massachusetts case. But obviously the whole litigation upon this Pratt patent cannot be regarded as favorable to the contention of the plaintiff in those cases, much less in this.

It is true that patents have been granted which seem to imply that the mere substitution of one material for another may result in a patentable article. In 1869 a patent was granted to Bond for a billiardtable the bed of which was composed of cement instead of glass or slate. In the same year a patent was granted to Deering for a railwayfastening of old form, but made of steel or other elastic metal. In 1871 a patent was granted to Phillips for a pavement consisting of a stone and gravel foundation, round wooden blocks, and sand filling, on the ground that they had never been used together before. And in the same year a patent was granted to Love for crocheted silk head-dresses for infants, on the ground that silk was softer and more comfortable than worsted, of which the article had theretofore been made. In 1876 a patent was granted to Pittman for a seamless boat or vessel formed

of celluloid. In 1878 a patent was granted to Hyatt for a comb made of celluloid. In 1881 a patent was granted to Lefferts and Carpenter for a head or other part of a doll made wholly or in part of celluloid; and so of a stay for corsets, a bottle-stopper, a collar, and for other articles.

But, on the other hand, in 1872 (ex parte Chatillon, C. D., 1872, 161; 20.G., 115) the substitution of malleable cast-iron for the ordinary sheetmetal material in the manufacture of shovels was held not to constitute invention. So in ex parte Chamblant (C. D., 1873, 119; 4 O. G., 106) it was held that spools having been previously made from paper it was not patentable to make bobbins from that material in the same form in which bobbins have been made from metal. And in later cases it has been held with almost unbroken uniformity that the claimed advantages of using one material for another did not involve invention. Thus, by Mr. Commissioner Hall in ex parte Krell, (C. D., 1888, 139; 44 O. G., 1505,) the substitution of Canadian fir for Swiss fir in sounding-boards for musical instruments was held not to confer patentability. To the same effect is Mr. Commissioner Mitchell in ex parte Odenheimer, (C.D., 1889, 240; 49 O. G. 1693,) involving the substitution of cotton for jute in the manufacture of bagging.

In 1884 the patent to Phillips came before the Supreme Court of the the United States, (Phillips v. Detroit, 111 U. S., 604,) and was declared invalid on the ground that bringing together three old and well-known elements-the wooden blocks, the foundation, the filling-did not involve invention. And in Brown v. District of Columbia (C. D., 1889, 398; 47 O. G., 398; 130 U. S., 87) the Supreme Court said of the Cowing patent of April 5, 1870, No. 101,590, for a new mode of constructing wooden pavements for streets, in which the claim was

a wood pavement composed of blocks, each side having a single plane surface, and one or more of the sides being inclined, and the blocks being so laid on their larger ends as to form wedge-shaped grooves, or spaces to receive concrete or other suitable filling, substantially as set forth

that there was nothing more than the substitution of one material for another without involving a new mode of construction or developing anything substantially new in the resulting pavement. The patent was held invalid.

Another case in the Circuit Court for the Northern District of OhioThe Sandusky Seat Company et al. v. Comstock et al., not reported except in C. D., 1878, 182; 13 O. G., 230, and 13 Brodix's A. and E. Patent Cases, 222, seems at first glance to give some support to the applicant's contention here. The action was for infringement of Reissue Patent No. 4,780 to Comstock and others, assignees of Simon P. Graham, for improvement in carriage bodies and seats. Among the claims were: 1. A carriage-body of which the sides and back are made of one entire piece of sheet metal, for the purposes specified.

2. A carriage-body made of sheet metal, formed in parts or sections, substantially as and for the purposes specified.

Upon the trial in the circuit court the learned judge was in doubt whether the invention was not in substance only the substitution of one material for another-iron for wood—and whether there was not want of patentability, but said that those defenses were not set up in the answer, as they should have been. In view of Smith v. Goodyear the Court inclined to think that the objection ought to be overruled and the respondents left to raise the question in the Supreme Court by appeal, and the patent was not declared invalid. Whether the question of the substitution of one material for another was in reality passed upon by the Supreme Court does not appear, for no opinion was rendered in the case, and it may also be noted that the decree was affirmed by a divided court.

After an examination of all the reported cases where the substitution of one material for another was relied on to confer patentability upon an article it appears that no article on account of the substance of which it is made can support a patent unless the new use of the substance is based upon some newly discovered property or quality in the substance. The use of gutta-percha as a coating for electric conductors was accordingly sustained by Judge Blatchford in Colgate v. Western Union Telegraph Company, (C. D., 1878, 440; 14 O. G., 943; 15 Blatchf., 365,) on the ground that Simpson was the first to discover that guttapercha was a perfect insulator, anticipating Faraday's publication of the same discovery by some months, and although wire had been covered before with rubber and other substances for other purposes than electrical insulation. Thus, too, carbon filaments in electric lamps in substitution for platinum wire was adjudged a valid basis for the Edison patent No. 223,898—in Edison Electric Light Company v. United States Electric Company, (C. D., 1892, 606; 61 O. G., 564; 52 Fed. Rep., 300,) although pencils of carbon, as well as platinum wire, had before that been used in lamps for obtaining subdivision of the electric light.

The abstract principle involved was known, at least it had been stated by Edison himself in his French patent of May 28, 1879. The ratio of the resistance of the burner to the resistance of the circuit and the relation of the resistance of the burner to its radiating-surface were known, and it was recognized that an electric incandescent lamp must have a burner of small cross-section and small radiating-surface. Platinum wire had been used for a burner; but because it fused at a temperature only slightly higher than that at which it became incandescent its use for the purposes of a lamp was impracticable. Carbon rods had been used; but oxidation soon destroyed them in any vacua then obtainable, and when the attempt was made to substitute an inert gas-such as nitrogen-for the air in a lamp-bulb the carbon rods were disintegrated by air washing. So no burner had stability to a degree exceeding mere experimental uses prior to the Edison invention and no material had been discovered for a burner in incandescent lamps which could sustain itself in the conditions which could then be provided.