Nearly all the claims in this case, as well as the specifications, speak of the beer in what is called the krseusen stage. The specifications term “krseusen” young beer, and also use the words “krseusen stage,” the inference being that it refers to that condition or the beer when it is considered young. But, in the evidence of the plaintiff, one of the witnesses particularly describes what the krseusen stage is. He calls krseusen a fermenting sweet-beer wort during the first stage of the main fermentation,.in which a foam of a very dense, curly white appearance is formed on the surface, and it is so termed because the beer has the appearance of curling, as krseusen in German means “curls.” The krseusen stage, he declares, is the new fermentation which sets in after the “krseusen beer” has been added. Under the old method, when the beer was in this condition in shavings casks, and the bung was left open, the foam and some of the ingredients of the beer escaped through-the bung-liole. As claimed in the plaintiff’s patent, this was avoided by stopping up the bung-holes, and devising a method by which the carbonic acid gas formed in the fermentation was permitted to escape upon a certain pressure, which removed the danger, that otherwise would exist, of bursting the casks, or of injuring the beer when in fermentation, or while being clarified.
■ All the claims except the last, it is insisted by the plaintiff, are for a process, and that as to them the particular manner or instrumen-talities by which'the process is accomplished are immaterial;
It is well known that the term “process” is not used in the statute, but it has been uniformly held that there may be a patent for a process, because it is regarded as an art, which is a word used in the statute. But it must be confessed that it is often one of the most difficult questions to decide, in the practical application of claims made in a patent, what is a process which may be the subject of a patent. To illustrate and prove this, it is only necessary to refer to the case of Mitchell v. Tilghman, 19 Wall. 287, which was most elaborately argued and fully considered, and where a majority of the court held that although the manufacture of fat acids and glycerine from fatty or oily substances by the action of water at a high temperature and pressure was a process, yet that the patentee was limited to the particular method or means of applying highly-heated water under pressure, pointed out in the specifications, although the claim was on its face broader than that, and to the case of Tilghman v. Proctor, 102 U. S. 707, where the same patent was in question, and where the court held that it was a patent for a process, irrespective of the particular mode or form of apparatus for carrying it into effect. If, then, we now- consider this last case in connection with one of the first cases *729decided by the supreme court, (Corning v. Burden, 15 How, 252,) and some of the intervening cases where patents have been sustained for a process, we ought to be able to determine the rule established by that court as to what is a process for which a patent can issue.
In Corning v. Burden the court said that one might discover a new and useful improvement in the process of dyeing, tanning, etc., irrespective of any particular form of machine or mechanical device, and another might invent a labor-saving machine, by which the same process might be performed, and each might be entitled to his patent; that one by exposing India rubber to a certain degree of heat, in mixture or connection with certain metallic salts, might produce a valuable product and be entitled to a patent for his discovery as a process or improvement in the art, irrespective of mechanical devices. And another might invent a furnace or stove, or some apparatus by which the same process might be carried on with a saving of labor and of expense, and he would be entitled to a patent for his machine as an improvement in the art, and yet one could not have a patent for a machine, nor the other for a process. Each would be entitled to a patent for the method of producing certain results, but not for the result itself. And the court further stated that it was when the term “process” was used to represent the means of producing a result that it was patentable, and it would include all methods or means not effected by mechanism. This definition is intelligible. A part of it, but not the whole, is cited in Tilghman v. Proctor.
In Corning v. Burden the court held that Burden had not discovered any new process, but a new machine or combination of mechanism by which the result was produced.
In McClurg v. Kingsland, 1 How. 202, where the only change made In the method of casting iron rolls was by directing the metal into the mould, when in a liquid state, at a tangent, the patent was sustained, although there doeg not seem to have been much discussion directly upon the patentability of the claim. All that was done in that ease was simply to change the direction of the tube which carried the metal into othe mould, the old method being to convey it from the furnace to the mould in a horizontal or perpendicular direction.
In Mowry v. Whitney, 14 Wall. 620, and Tilghman v. Proctor, supra, the court sustained the claim in each as a patent for a process. In the latter case, the court says that the patent law is not confined to new machines and new compositions of matter, but extends to any new or useful art and manufacture, and that a manufacturing process is an art.
Goodyear’s patent was for a process; namely, vulcanizing India rubber. The apparatus for performing the process was not material, and was not patented, and the court then refers to Neilson’s English patent. ISfeilson’s patent was for the discovery, which he made, of applying a blast of hot air, instead of cold, to a smelting furnace, and for describing a method by which that was accomplished, that *730method not being material, and the court declares that Neilson’s patent was sustained as a process patent, and quotes the language of the court of exchequer, “that the plaintiff did not merely claim a principle, but a machine embodying a principle, añd a very valuable one;” and also the language of Lord Campbell, in the house of lords, that “the patent must be taken to extend to all machines, of whatever construction, whereby the air is heated intermediately between the blowing apparatus and the blast furnace;” and therefore it was unnecessary to compare one apparatus with another.
The court, in Tilghman v. Proctor, also quotes the language of Chief Justice Taney in O’Reilly v. Morse, 15 How. 112, where he says, in commenting on Neilson’s Case, 8 Mees. & W. 806,—
“That the manner in which air might be heated was immaterial. His.patent was supported because he (Neilson) had invented the mechanical apparatus by which the current of hot air could be thrown in. The interposition of a heated receptacle in any form was the novelty he invented.”
And, after quoting still further from the opinion of the Chief Justice in O’Reilly v. Morse, the court states:
“It seems to us that this clear and exact summary of the law affords the key to almost every case that can arise. ‘ Whoever discovers that a certain useful result will be produced in any ai-t by the use of certain means, is entitled to a patent for it, provided he specifies the means.’ It is very certain that the means need not be a machine or an apparatus; it may be, as the court says, a process. A machine is a thing. A process is an act, or a mode of acting. * * * The mixing of certain substances together, or the heating of a substance to a certain temperature, is a process. If the mode of doing it, or the apparatus in or by which it may be done, is sufficiently obvious to suggest itself to persons skilled in the particular art, it is enough in the patent to point out the process to be performed, without giving supererogatory directions as to the apparatus or method to be employed. ”
The majority of the court in O’Reilly v. Morse refused to sustain the eighth claim of Morse, because he disavowed the specific machinery or means mentioned, but claimed the use of the motive power of the electric current, however developed; and this was held to be a principle simply.
■ There has always been some difference of opinion as to the true grounds upon which this rejection of the eighth claim of Morse was placed, it being maintained by some that Morse was not entitled to have a patent including all applications of what he termed electromagnetism in the transmission of words, letters, and signs, but onlv his own particular application.
It has been uniformly held that a patent for a mere principle, or what is sometimes called a law of nature, cannot be sustained; but in all the cases referred to, from the Neilson to the Tilghman patent, the law or laws of nature discovered were utilized, and it is said that in giving this construction to principle and process, a patent for a process leaves the field open to future inventors; .whereas a patent for a principle or a law of nature would give a monoply to the person making that discovery. So that the rule established by the su*731preme court is said to be that the patent for a process will include every application of the principle that involves the use of the ptocess described and claimed by the patentee, and this does not include the particular machine or apparatus described by the patentee, but the modo of operation which is carried out by means of the apparatus. Walk. Pat. § 14.
In Neilson’s Case the defendant did not use the means employed by Neilson in throwing the hot air to the smelting furnace, for it was admitted he used a better device; but it was assumed that when once the idea existed in the mind of the superiority of a hot-air blast to a cold one, any person skilled in smelting could devise his own mode of introducing the hot air to the furnace. And see Cochrane v. Deener, 94 U. S. 780, and Rubber Co. v. Goodyear, 9 Wall. 796.
It is to be regretted that the difficulty inherent in the subject is so great that a more intelligible distinction has not been made, for it must be admitted that the application of the rule which has been established by the supreme court to other cases, as they hereafter arise, may cause embarrassment, for there must be a method by which the principle or law which has been discovered is applied; and, if that method is immaterial, then it is difficult to understand why it does not become substantially a patent for the discovery of the principle or the law of nature. Such seems to have been the opinion of Mr. Justice Nelson. See Foote v. Silsby, 1 Blatchf. 445, and 2 Blatchf. 260; and the case on appeal, 20 How. 378; Le Roy v. Tatham, 14 How. 156, and 22 How. 132.
If it be true that the defendants have used the mechanical devices of the plaintiff, the question is whether, within these cases and the rules which have been established upon the subject, the plaintiff is entitled under his patent to the claims which he has made and as set forth; namely, the process of preparing beer for the market by holding it under controllable pressure of carbonic acid gas when in the krseuson stage; the process of treating it, when in the kiTeusen stage, by holding it in a vessel under automatically controllable pressure of carbonic acid gas; the process of preparing and preserving beer for the market, holding it under controllable pressure of carbonic acid gas from the beginning of the kramsen stage until it is transferred tó kegs and bunged; to the method of preserving beer; to the process of treating it when in the second fermenting stage, and the process of treating it in the course of its manufacture; and to the process of clarifying and settling beer in a series of shavings casks and equalizing the rate of fermentation in all of them, whereby the beer is more rapidly and thoroughly clarified, irrespective of the mechanical means by which the specifications declare these various processes can be accomplished. That is to say, were Meller & Hof-mann the first persons to hold the beer, when in its krseusen stage, under controllable pressure of carbonic acid gas, and were the means by which that result was accomplished immaterial ?
*732There is not entire accord among the -witnesses as to what constitutes the krteusen stage, but we may assume that it was understood to be, when the beer was in that condition in the shavings casks that young beer was added, upon which fermentation was produced, and during which the process of clarification was going on, in addition to other results caused by the mode adopted to act upon the beer; because, as soon as the fermentation began by the introduction of the krseusen, the shavings operated upon the ingredients contained in the beer.
Where, in a process, there is a combination of different substances, and to that combination another substance or element is added, by which a new result is obtained, that is a process which we can easily understand; and if unknown before, and it is useful, the person devising it may be entitled to a patent. Where there is a result produced by machinery, which result may be brought abóut by a process, and which may consist of different steps caused by a combination of different parts of the machine, and another part is added, before unknown, and by which a useful result is produced, that we can understand. The difficulty is to comprehend a process which may consist partly of a combination of different substances operating chemically, and the combination of different parts of a machine operating mechanically.
If a process exists which consists of different steps created by machinery, and there is an improvement in that process caused by a new element added to or taken away from the machinery, then, the process existing and being known, the party who added or took away the part of the machinery might, if it were useful, be entitled to a patent, not for the process which formerly existed and was well known, but only for that which had been added to or taken from the mechanism.
To apply the principle to this case: the process of manufacturing beer was not, at the time this patent was issued, per se, patentable, for beer had long been manufactured; in the first place by the preliminary steps which are referred to in the specifications, and which have already been mentioned, and by adding to the beer the kraeusen while it was in shavings casks, and then permitting fermentation to proceed, then clarifying it so as to retain in the beer some of the carbonic acid gas, which of itself constituted an important ingredient in the beer, and then preparing it for the market, so that whatever was patentable in the process of manufacturing beer must consist of something new and useful being added to the process chemically or mechanically, and for whatever was new and useful the inventor might be entitled to a patent, whether it was connected with the chemistry or the mechanism of the process. It is very important to observe this distinction in discussing the patentability of a process.
It seems to be admitted in the various process cases decided in the supreme court, which have been referred to, and others which might *733be named, if the process consists of a chemical combination by ■which the particular result is produced, that does not prevent another inventor from making a mechanical combination which produces the same result. Otherwise, there vyould be a revolution in“what has always been understood to be a principle of the patent law, that a person could not patent a result, but only the means or acts by which the result was produced; and that certainly should be true as well of a chemical as a mechanical combination.
It will be borne in mind that the patentee in this case insists that the invention is not limited to the particular instrumentalities described, by which the beer is held under controllable pressure of carbonic acid gas when in the krasusen stage, because it is said that other means than a water column may be adopted for equalizing the pressure of the gas, without departing from the spirit of the invention, — as, for example, safety-valves, springs, and the like; and it is added that the apparatus is susceptible of many other variations without affecting the process itself. Now, a water column had been previously used to regulate the pressure of the carbonic acid gas, and valves and springs had often been used for the same purpose; and, indeed, some of the witnesses of the plaintiff seem to imply that the Wallace and Hicks devices, in use long before the plaintiff’s patent, were, in their application to the manufacture of beer, like those of the plaintiff. I am, therefore, not prepared to concede that Meller & Hofmann were the first to hold under controllable pressure of carbonic acid gas the beer when in the krseusen stage, for, as already stated, that had been done as well by a column of water as by springs and valves when the shavings casks were bunged and stopped; and the gas was permitted to escape when the pressure became so great as to raise the valve or force the spring. This is shown by the evidence of Mans and Sturm. It may be admitted that the mode adopted by the plaintiff is valuable, and that it has facilitated the manufacture of beer, both as to quality and as to time. But it seems to me that this has been caused by the more complete mechanical devices of the plaintiff, without really changing the principles upon which beer had been theretofore manufactured.
No new principle or scientific fact has been discovered, as was true in the process patents which have already been referred to. The most that can be claimed is, and, indeed, the chief merit ascribed to the patent by the plaintiff’s counsel is, that it applies the controllable pressure created by the carbonic acid gas, in a state of fermentation, at an earlier stage than was before known. But the essential parts of the apparatus used by the patentee were known before, and the same controllable pressure had been applied at various stages of the manufacture, and the application at one stage of the condition of the beer, instead of another, would seem not to involve anything more than a mere mechanical change, which, could be employed by any one skilled in the art.
*734If we assume that the invention of a process always authorizes a patent, irrespective of the means by which the result is produced, it would seem to be attended with very important and far-reaching consequences, and to involve substantially a monopoly of the principle, or of the discovery of a new scientific fact; and in this way we would impair, if not destroy, the effect given by the supreme court to the various rules which have been heretofore referred to as established by that court, one of which has always been held to be firmly fixed; namely, that a person should only have a patent for the means by which the result is produced, and not for the result itself.
It follows, therefore, from what has been said, that the claims of the plaintiff for a particular process, irrespective of the means by which that process has been reached, cannot be sustained; and that the effort made to enlarge the construction of the patent law so as to cover any means which may be used in the process of the manufacture of beer — namely, by the methods which have been heretofore substantially employed — cannot succeed, it being a process well known before. A person could only have a patent for that by which the process was improved or cheapened; and it cannot be successfully claimed, I think, that the defendants have used the various mechanical devices which are set forth in the specifications. It is not necessary to declare in this ease that those devices, taken in the aggregate, might not be the subject of a patent as mechanical devices.
The result is, the plaintiff’s case fails on both grounds on which it is put: First, as a patent for a process, as described and claimed; and, secondly, for an infringment of the mechanical devices of the patent.
The bill must be dismissed.