ditional confirmation to the conclusion that the process of the patentee contemplates high heat and rapid manipulation is also found in the other parts of the specification. Evidently the inventor is of the opinion that the operator must be exposed to imminent danger unless the vessel is one of very great strength, as he states that he deems it prudent to test the strength of the apparatus by a pressure of ten thousand pounds to the square inch before taking it into use. Such a test he deems prudent, before using the vessel, but he expresses the opinion that 383*] the working *pressure necessary in using the degree of heat required will not be found to exceed two thousand pounds to the square inch, which admission of itself is sufficient to maintain the conclusion that high heat is the agent which the inventor in his process employs to decompose the substances subjected to the patented process. Certain substances, such as palm-oil, the inventor represents, may be decomposed and converted into fat acid and glycerine under his process when the temperature is at or below the melting point of bismuth, but he states that the heat in decomposing such a substance may be raised considerably above the melting point of lead without any apparent injury, and he adds that the decomposing action of the water becomes more powerful as the heat is increased. Considered as a whole, these several consider ations show to a demonstration, in the judg ment of the court, that the invention described in the specification and embodied and claimed in the patent is the use of great heat in the manner described to decompose the described substances when properly prepared, by being pulverized or broken into small particles and mixed with water, and cause the elements of the decomposed substances to unite with the particles of the heated water by which the mixture is converted into fat acids and solution of glycerine. Manifestly great heat, applied in the method described, is the principal agent, but water is an essential ingredient, as without it the product of decomposition would be destroyed in the operation. Evidence that the inventor contemplates that the change in the substance shall be accomplished in a brief space of time abounds in the specification. Ten minutes is the maximum time suggested that the high température should be maintained while the mixture is flowing through the heated tubes before it passes into the refrigerator, but the patentee also states that it is important for the quickness and perfection of the decomposition that the oil and water should continue, during the passage of the emulsion through the heating tubes, in the same state of intimate mixture as they were when the mixture was driven into the heated 384*] coil, and to that "end the inventor states that he prefers to place the series of heating tubes in a vertical position, so that if any partial separation takes place while the liquid passes up one tube, the change may be corrected as the liquid passes down the next. Suitable means are pointed out to indicate to the operator the state of the heat in the tubes, and for that purpose the inventor suggests the making of certain indicators or gauges showing the melting point of certain metals and other substances of different and known degrees of fusibility, and he gives the series which he has used, which consist of tin, melting at 440° Fah.; bismuth, 510° Fah.; lead, 610° or 612° Fah.; nitrate of potash, 660° Fah.; and he describes the mode in which such gauges may be constructed. Palm oil will be decomposed by heat at 510° Fah., and the inventor mentions that as the lowest gauge for the treatment of any known fatty or oily substance to be subjected to the patented process under consideration. Ordinary fats, such as beef tallow, or the tallow of sheep, require the heat to be raised to 612° Fah., which is the melting point of lead. Mention is made in the series set forth in the specification of the melting point of tin, which is 440° Fah., but the mention of that chemical fact was doubtless made as a guide to the operator in carrying up the heat to the point necessary to decompose the respective substances, such as palm-oil or the ordinary tallows, all of which require the heat to be raised to a point higher than the melting point of tin. No different conclusion can be reached, a there is nothing in the record which gives any countenance to the theory that the meltingpoint of tin 450° Fah., was given as a gauge of heat which,. under the process of the patentee, would decompose any known fatty or oily substance in such a manner as would enable the operator to manufacture the product described in the patent. Substances are mentioned in the specification which, under the described process, would require the heat to be raised to the melting point of bismuth and to the melting point of *lead, but the specification does not [*385 make mention of any substance of the kind which can be decomposed as required at the melting point of tin, nor does it mention any one which for the same purpose would require the heat to be raised to the melting point of the nitrate of potash. Probably the former was mentioned for the guidance of the operator, as before explained, and it may be that the latter was given for a corresponding purpose as the maximum limit for the operator in raising the heat to decompose such fatty and oily substances as the ordinary beef tallow or the tallow of sheep, which require the heat to be raised to the melting point of lead in order to produce a good result under the patented process. Two other requirements of the specification support the theory that high heat is the principal agent of the patented process, and that the vessel to be used for heating the mixture must be kept closed during the process of decomposition, and be one of sufficient strength to sustain, without bursting, an internal pressure of at least two thousand pounds to the square inch. One is that the exit valve is required to be so loaded that when the heating tubes are at the desired working temperature the valve will not be opened by the internal pressure produced by the application of the heat to the mixture, so that when the pump is not in motion none of the mixture will escape at the other end of the apparatus; and the other requirement is that "No steam or air shall be allowed to accumulate in the tubes, and that the tubes shall be kept entirely full of the mixture." Argument to show that the vessel used for heating the mixture must be kept closed is unnecessary, as the terms of the specification ex pressly require it, and the patentee to that end directs that if practicable the ends of the tubes should be welded, and if not, that they be connected by certain described joints to accomplish the same purpose, evidently regarding a compliance with the requirement that "the vessel must be closed" as an indispensable condition. Half or one third of the mixture to be subjected to the patented process is water, and the 386*] condition set forth in the specification is imperative that the vessel used for heating the mixture must be closed, that the requisite amount of pressure may be applied to prevent the water from being converted into steam; and it is also an express condition that no steam or air should be allowed to accumulate in the tubes, for reasons which will be obvious to any who will carefully examine the described method of producing the described result. Means of a mechanical character are prescribed in the specification for intermingling the fat and the water into what is called an emulsion, which is the mixture to be subjected to the patented process; but the difference between such an intermingling of one substance with another, which may be accomplished by a stirrer or by the churning process, and the actual union produced by chemical affinity between two or more substances, is as wide as one thing well can be from another. Such an intermingling of fat with water does not work any chemical change in either substance, as it creates at best but a temporary affinity. Consequently the water, if the mixture is left for a sufficient length of time undisturbed by the stirrer or piston, will separate from the particles of fat and settle at the bottom. Widely different results flow from chemical affinity, as such an affinity will produce a new and distinct substance, uniting, it may be, the constituents or properties in whole or in part of substances as different as fat and water. glycerine, but it is clear that heat alone will not produce either of those fat acids or the solution of glycerine, as the three acids and the glycerine are chemically combined in the original substance with the oxide of glyceryl as an acidifying base. Temperatures such as described will decompose the fat, but unless some chemical agent, such as water, lime, soda or potash, is present to take the place of the oxide of glyceryl to acidify the oleine, the margarine and the stearine, or to oxidize the said several constituents and to convert the same into oxide of oleine, margarine and stearine, neither of the fat acids required, to wit: oleate, margarate, or stearate, can be obtained from the decomposition of fats by heat, as the oxide of glyceryl, which was their base in the original substance, is separated by the act of decomposition; nor is it possible, unless water or its equivalent be present when decomposition takes place, to obtain solution of glycerine, for reasons equally conclusive though somewhat dissimilar in the chemical sense, as the presence of water or its equivalent is required in the latter case to hydrate the glyceryl and convert the same into the solution of glycerine. Without the presence of water or its equivalent constituents, neither the fat acids mentioned nor solution of glycerine will be obtained *by heat, but with it the three fat [388 acids mentioned and solution of glycerine will be produced if the operator complies with all the other conditions prescribed in the specification. Silliman, Chem., 25th ed., p. 441. Viewed in the light of these suggestions. as the question should be, it is quite clear that the two conditions last named, to wit: that the heating vessel must be kept entirely full of the mixture and that no steam or air must be allowed to accumulate in the vessel employed to impart the heat, are material and indispensable conditions of the patented method of producing fat acids and solution of glycerine from the described substances, as without a compliance with those requirements there might not and probably would not be present when decompo Fats consist of several constituents closely united in indefinite proportions, of which oleine, margarine and stearine are the only ones usually recognized and defined by chemists; the form-sition takes place any equivalent of a base to er constituting the oily and the two latter the solid principle of the united substance. 1 Regnault, Chem., sec. 1592. take the place, of the oxide of glyceryl and to unite with the oleine, margarine and stearine to convert the same into the three fat acids known as oleate, margarate and stearate. These three constituents in the fat, to wit: oleine, margarine and stearine,' are combined with the oxide of glyceryl as a base, and when decomposition is effected under the influence of heat, some chemical agent, such as water or its equivalent, must be present, which can take the place of the oxide of glyceryl to change the three constituents of fat just named into the oxides of oleine, of margarine and of stearine. 3 Miller, Chem., p. 370, sec. 1141, 2 Ure, Chem. Dic., 5th ed., 379. These constituents or elements are held together by chemical affinity, the consistency of the united substance depending upon the respective proportions of the constituent parts. High heat will overcome the affinity by which the constituents are united and decompose the 387*] substance. Different kinds of fat, however, require different degrees of heat to effect the decomposition of the united substance, varying in intensity from 510° Fah., the melting point of bismuth, to 610° or 612° Fah., the melting point of lead, which are the very temperatures mentioned as required in the specification of the complainant's patent. But it should be remarked in this connection that the decomposition of such a substance by heat alone will not produce fat acids or solution of glyce-verted that, in all methods heretofore practiced, rine. Turner, Chem., by Johnston (8th ed.), p. 456. Free fat acids and solution of glycerine are what the patentee promises as the result of a proper application of the patented process. Those acids, it is conceded, are oleate, margarate, and stearate, which, it is claimed, the process will produce, together with the solution of Some chemical agent must also be present to take the place of the constituent which was combined with the glyceryl to produce the solution of glycerine, as represented in the specification; and it does not appear to be contro water or its equivalent has always been present for such purpose, and it is manifest that the requirement that water or its equivalent shall be present to accomplish that purpose, in the specification, is an indispensable condition, as the new substance would otherwise be destroyed by the operation, which requirement cannot be fulfilled unless the vessel is kent 389*] *entirely full of the mixture, as other- | Agawam Co. v. Jordan, 7 Wall., 597, 19 L. ed.. wise steam and air will accumulate and fill the vacuum. Water must be present in the mixture to furnish the requisite constituent to unite with the oleine, margarine and stearine and to oxidize the same, else it will be impossible to obtain the described fat acids; and the presence of water in the mixture when the decomposition takes place is also equally indispensable to furnish the requisite constituent to take the place of the oxide evolved by the operation from the glyceryl and to unite with the other constituents of the same to produce solution of glycerine, which the specification alleges is one of the results to be obtained from the decomposition in the method therein described. Unless water or its equivalent be present to furnish such constituent to take the place of the oxide evolved from the glyceryl, the same heat that separates the glyceryl from the other constituents of the fat in the mixture will convert the same into acroleine, which is an offensive substance destitute of any useful quality; or, in other words, the glyceryl will be converted into a substance which is neither new nor useful, and of course the process to obtain it would not be the proper subject of a patent. 2 Watts, Chem. Dict., 894; Attfield, Chem., 394; Silliman, Chem., 25th ed., p. 44, sec. 763. Nothing provided in the patent or suggested by the patentee will secure the presence of water when decomposition takes place, unless the vessel be closed and be kept entirely full of the mixture, as otherwise the water will be converted into steam, and steam and air will accumulate in the heating vessel. No means are described or suggested to add water to the mixture after the mixture is forced into the heating vessel, and it is plain that nothing of the kind can be successfully accomplished without some material change in the apparatus. 180. Sufficient has already been remarked to show what the alleged invention is, as construed and defined by the court. Having ascertained that matter, the next inquiry is, whether the complainant is the original and first inventor of the improvement. 1. Persons seeking redress for the unlawful use of patented inventions must allege and prove that they are the original and first inventors of the same, and that the party defendant is guilty of the alleged infringement. In the first place, the burden to establish both of those allegations is upon the party instituting the suit, but the rule, as before explained, is that where the complainant or plaintiff introduces the patent in evidence, if it is in due form, it affords a prima facie presumption of its correctness, which, in the absence of [*391 opposing proof, will entitle the complaining party to relief. Availing himself of that rule, the complainant introduced his patent in evidence; which is sufficient to show that he is the original and first inventor of his improvement, as construed and defined by the court, unless sufficient evidence to overcome that presumption and to establish the contrary allegation of the answer is exhibited in the record. Seymour v. Osborne, 11 Wall., 538, 20 L. ed. 37. Whether tested by the language of the claim or by that of the patent, or by the language embodied in the two introductory sentences of the specification, it is equally clear that the patentee, at the time the patent was granted, did not pretend that he was the original and first inventor or discoverer of the scientific truth that high heat or water heated to a high temperature would decompose such fatty and oily substances as those mentioned in the specification of his patent, and the evidence in the record shows that such a pretense, if it had been made, could not have been supported for a moment. Beyond all doubt the conditions mentioned appertain to the described method patented by the complainant for producing fat acids and so- Opposed to that proposition it is suggested lution of glycerine from fatty and oily substan- that the patentee claims "the manufacturing ces of animal and vegetable origin, which con- of fat acids and glycerine from fatty substances 390*] tain *glyceryl as their base, but it is by the action of water at a high temperature equally clear that the patentee does not claim and pressure," which must be admitted, subject the described apparatus as any part of his into the universal qualification that the legal convention, and that he is not the original and first inventor or discoverer of the scientific truth that such fats as beef tallow and palm-oil may be decomposed by heat or by heat and water combined nor of the scientific truth that fat acids of commercial value may be obtained from such substances as tallow and palm-oil by means of heat or by heat and water. struction of every such claim, is that the patentee means to limit the same to his described method or process; or, if it be a machine, to his described means of obtaining or of accomplishing the described result. Usually the claim contains the words "as described or substantially as described," or words of like import, which are everywhere understood as referring back to the descriptive parts of the specification. Words of such import, if not expressed in the claim, must be implied, else the patent in many cases would be invalid as covering a mere function, principle, or result, which is obviously forbidden by the patent law, as it would close the door to all subsequent improvements. mour v. Osborne, supra; Curt. Pat., sec. 242. Sey Power to issue letters patent is conferred upon the Commissioner of Patents, and inasmuch as such grants are executed by public authority and in pursuance of an Act of Congress, the rule is that the patent, when introduced in evidence by the complaining party in a suit for infringement, affords a prima facie presumption that the patentee is the original and first inventor of what is therein described and claimed *Doubtless, an invention may be good [*392 as his invention. Application for a patent is though the subject of it consists in the discovrequired to be made to the commissioner ap- ery of some principle of science or property of pointed under authority of law and, inasmuch matter, never before known or used, by which as that officer is empowered to decide upon the some new and useful result is obtained, and merits of the application, his decision in grant- such an invention or discovery may be the subing the patent is presumed to be correct.ject of a valid patent without including in the claim any new arrangement of machinery to accomplish the object, provided the inventor describes, as required in the patent law, the method, process or means of applying the invention to practical use and of obtaining the described new and useful result. Househill Co. v. Neilson, 1 Web. Pat. Cas., 683; Curt. Pat., 4th ed., 279; Foote v. Silsby, 2 Blatchf., 260. Limited, as explained by reference back to the descriptive parts of the specification, the claim may well be regarded as in due form, but it is quite clear that it would be invalid if it is not so limited, as it has always been held that a patent embraces nothing more than the improvement described and claimed as new, and that any one who afterwards discovers a method of accomplishing the same object, substantially and essentially differing from the one described, has a right to use it and to vend it to others to be used. O'Reilly v. Morse, 15 How., 119; Curt, Pat., 4th ed., sec. 163. Apply that rule and it is clear that the invention must be limited to the described method of producing free fat acids and solution of glycerine from the fatty and oily substances therein mentioned, as the patent states that the patentee alleges that he has invented a new and useful improvement in processes for purifying such fatty and oily substances, and the opening sentence of the specification describes the invention as a new and improved mode of treating fatty and oily substances, and the patentee, in describing his invention, states that it consists of a process for producing free fat acids and solution of glycerine from such fatty and oily substances as are therein particularly described, and there is not a word, either in the specification or claim of the patent, to warrant the conclusion that the patentee or the Commissioner of Patents, at the time the patent was granted, regarding the patentee as the original 393*] and first inventor or discoverer of the scientific truth that such fatty and oily substances may be decomposed by high heat or water heated to a high temperature. | ture than that which should prove to be requisite to accomplish the described result. Suppose that could be admitted, still it is not probable that the admission would much vary the case if the apparatus employed should not be changed, and all the conditions for applying the process should remain in full force, as rapid manipulation is an express condition in applying the process of decomposition, which, it is believed, cannot be accomplished in the time allowed unless the high temperature is maintained. Support to the theory that the gauges given admit of a wider variation than is here supposed, is attempted to be drawn from the sentence in the specification which immediately *follows the statement that the decom- [*394 position of the water becomes more powerful as the heat is increased. Fatty matters, such as palm-oil, says the patentee, may be changed into fat acids and glycerine at or below the melting point of bismuth, but he states in the same connection that the heat in such a case has been carried considerably above the melting point of lead without any apparent injury; and he adds that the decomposing action of water becomes more powerful as the heat is increased. Then follows the sentence which is invoked as supporting the theory that the gauges of heat given in the specification, to wit: the melting point of bismuth and the melting point of lead, are subject to indefinite variation. By starting the apparatus at a low heat, says the patentee, and gradually increasing it, the temperature giving products most suitable to the intended application of the fatty substance employed, can easily be determined. Evidently the sentence should be examined in the light of the context, and when so examined it is quite clear that the patentee never intended to employ the language in any such sense as that which the complainant ascribes to it, as he was speaking of palm-oil, which is decomposed at the melting point of bismuth, and had just remarked that the heat, in applying the process to that substance, had been carried considerably above the melting point of lead without any apparent injury. Unquestionably, the method or process embodied in the patent includes high heat and rapid manipulation, but the patentee is not the original and first inventor of the scientific Water, said the patentee, becomes more powtruth that heat or water at high temperature erful to decompose such substances as the heat will decompose such fatty and oily substances is increased; and then adds, as a precaution to as those mentioned in the specification. Dif- the operator, not to carry it too high above the ferent gauges of heat to be employed in apply-gauges given. You can easily determine what ing his process are certainly given in the speci- is best in any given case by starting the appafication, as before explained, but it is a great ratus at a low heat and gradually increasing it mistake to suppose that the gauge for decompos- to the gauge given or above, as may appear to ing such fats as beef tallow or the tallow of be best from the particular substance subjected sheep admits of any variation except what is to the process and the quality of the product authorized by the word "about," or that the obtained by the operation. Not an intimation gauge given for decomposing palm-oil may be is given in the sentence that any less heat will varied from the melting point of bismuth, ex- accomplish the purpose than that indicated by cept so far as the authority to diminish the the gauges mentioned in the specification. On temperature may be inferred from the words the contrary, the language employed, if it "at or below," which words, when properly con- *warrants any substantial variation [*395 strued, mean substantially the same thing as from the prescribed gauges, justifies the inthe word "about," when the latter is used to ference that the heat may be increased above qualify the temperature designated as the melt- the temperatures mentioned rather than dimining point of lead. ished. Attempt is made in argument to show that High temperature and pressure are among the the respective gauges given in the specification leading characteristics of the invention, as apto specify the required degree of heat are sub- pears from the claim and every part of the specject to a much wider variation, and that the ification. Doubtful expressions may be subpatentee did not intend to require that the mixt-ject to construction, but where the language ure should be exposed to any higher tempera- employed is clear and unambiguous it must speak its own construction in the specification | of a patent as well as in any other grant issued by public authority. Intention in every case, it may be admitted, is the primary rule of construction, but language invoked to support a particular theory must be such as is fit, when it is compared with the whole instrument, to express the imputed intention, else the theory in question cannot be supported, as courts of jus tice cannot legislate nor can they add to a grant or contract any stipulation or condition which it does not contain. Consequently, the theory of the complainant, that the sentence under consideration warrants the conclusion that the claim of the patent includes low as well as high heat, must be overruled. Green v. Wood, 7 Q. B., 178; Pott. Dwarris, 199, 200. Additional observations respecting the apparatus employed by the patentee are unnecessary, as he expressly states that he does not intend to claim it as any part of his invention. Enough has already been remarked also to show what is the nature and scope of the invention, and to point out what the question is which is involved in the first issue presented in the pleadings. Construed and defined as explained, the first issue respecting the patent must be found for the complainant, as the proofs in the record bearing upon the question of novelty are not sufficient to overcome the prima facie presumption that the patentee is the original and first inventor of what is described in the patent as his invention. R. Co. v. Stimpson, 14 Pet., 458, Curt. Pat., 4th ed., sec. 472. 2. Grant all that, still it is insisted by the 396*] respondent that "the result described in the specification and claim of the patent cannot be accomplished so as to be practically useful by the method and apparatus described in the specification. Whoever discovers that a certain useful result will be produced in any art, machine, manufacture or composition of matter by the use of certain means is entitled to a patent for his invention, provided he specifies the means he uses in a manner so full and exact that anyone skilled in the science to which it appertains can, by using the means he specifies, without any addition to or subtraction from the described means, produce precisely the result he describes. Such description must be correct, as it is settled law that the patent is void if the described result cannot be obtained by the described means. O'Reilly v. Morse, supra; Curt. Pat., 189. Nor does it make any difference whether the effect is produced by mechanical principles or by chemical agency or by the application of discoveries in natural science, as in either case the requirement of the Act of Congress is imperative that the patentee must describe the method, process or means he employs in full, clear and exact terms, and the end which the invention accomplishes. Inventions, in order that they may be the proper subjects of letters patent, must be new and useful. Utility in most cases is a question of fact, as it usually depends upon the evidence resulting from actual experiment. There are two modes, says Mr. Curtis, in which the utility of an invention may be impeached, the second of which is where it appears that it is not capable of being used to effect the object pro posed, which is the question presented in the second defense set up by the respondent. Curt. Pat., 4th ed., sec. 449. Cases arise, also, even where the means described will accomplish the described result, when it cannot be held that the invention is useful if it appears that the operator, in using the described means, is constantly exposed to imminent danger, either from the explosive tendency of the substance to be used or [*397 from the liability of the vessel to burst which is required to be employed as a means of accomplishing the patented result. Where the patentee finds it necessary to employ any such dangerous means to accomplish the described end it cannot be held that his invention is useful, within the meaning of the patent law, even though it appears that the operator, when no such disaster happens, may be able to work out the described result by the described means, as it is quite clear that Congress, in making provision to secure to inventors the exclusive right to their discoveries, never intended to promote any such as were in their nature constantly dangerous to the operator in employing the described means to accomplish the described result. Curt. Pat., 4th ed., secs. 106, 449. one Apply these rules and it follows that neither an invention which will not enable the operator to accomplish the described result, nor which constantly exposes the operator to the loss of his life or to great bodily harm, can be regarded as useful within the meaning of the patent law. Patents were granted to the supposed inventor by the proper public authorities in England, France and Belgium, as well as by the proper public authorities in the United States, but the respondent insists that the described result cannot be obtained by the means and in the mode of operation described in the specification, and that the invention has never been reduced to practice by the use of those means or in that mode of operation, either in the United States or in any one of the foreign countries where the same has been patented. Both branches of the proposition are controverted by the complainant and many depositions and other proofs upon the subject were introduced at the hearing. Witnesses were examined by the complainant to prove the affirmative of the issue, but none of them appear to sustain his views in that behalf unless the scope of the invention is extended beyond the means and mode of operation described in the specification as construed and defined by the court. Proofs *of the kind, if they ex- [*398 ist, could casily have been procured, as both the complainant and his brother, who acted as his agent in efforts to introduce the invention in the United States, were examined as witnesses in the case. Licenses were given by the complainant in some instances, and he called Charles T. Jones, one of his licensees, to prove the affirmative of the issue under consideration. It appears by his deposition that he became a member of a certain firm in 1849, and that the firm were engaged in the manufacture of candles; that they first used the process of saponification with about fourteen per cent. of lime in an open vessel; that they decomposed the lime soap thus obtained by sulphuric acid, using for that purpose two and a half pounds of sulphuric acid to |