(dissenting). I agree that if the patent is valid infringement is certain. My trouble is with the validity of the patent. I have not been able to discover invention in the method disclosed by its claims in view of so much of the prior art as we are permitted to look at and consider. Of course, had Pauling been first to conceive a rectifying column and had he been first to use it as a means to separate an admixture of sulphuric acid and nitric acid and in one operation produce the latter in concentrated form, his would have been a great invention. But Pauling did not do that or anything close to it. What he did was to go to the highly developed art of fractional distillation and select old and well-known means and methods and add one questionably new element. , Of these, the main means he appropriated was a rectifying column with its accompanying method, which was described with admirable simplicity by Lord Moulton in British Liquid Air Company, Ltd., v. British Oxygen Company, Ltd., British Court of Appeals, 25 R. P. C. 606, to be “a, well-known device in continuous distillation, and consists essentially in a column so filled either with baffle plates or broken stone or small spheres that vapour or liquid passing along it must pursue very devious paths, passing preferably through narrow crevices. If we imagine fluid passing down such a column and vapour passing up it simultaneously, it is evident that they will, in so doing, be brought into the most intimate contact. Suppose now, for example, that the descending stream is a mixture of water and a more volatile liquid, such as alcohol, and the ascending stream is steam, the hotter vapour will be continually parting with its heat to the minute streams of water that it meets and partially evaporating them, itself becoming thereby partially condensed. The alcohol, by reason of its greater volatility, will have the preference in these innumerable partial evaporations, and will pass on with the remaining steam, so that the vapour, as it proceeds upwards, will get richer and richer in alcohol, while the fluid, as it proceeds downwards, will consist more and more completely of water. It gains heat, but loses alcohol. In this way, a continuous process of separation can be carried on, and when it is in regular working the proportion of alcohol at any specific level in the eolumn will be constant, and will gradually increase as you go up the eolumn, from a very low percentage at the bottom to the full strength of the distillate obtainable at the top, while the temperature follows the contrary law and gradually rises as you pass down the column.”
As pointed out by Lord Moulton in the cited ease, brought to our attention in Air Reduction Co. v. Carbo-Oxygen Co., 17 F.(2d) 138, recently argued in this court, precisely the same thing takes place in Linde’s rectifying eolumn where (in another art) relatively warm oxygen vapors ascending the column meet a descending stream of excessively cold *102liquid air with its nitrogen and oxygen combined and an infinitude of small partial evaporations takes place, in all of which nitrogen, the more volatile element, has the preference and on being separated from oxygen rises as a gas and is piped off, and oxygen, the less volatile element, separates and condenses and falls as a liquid to the bottom of the column and is there recovered for industrial uses.
Pauling knew or, is charged with knowledge of such practices; the two I have given are but illustrations of many in different though related arts. Nor was Pauling’first to treat an admixture of nitric acid and sulphuric acid ánd separate one. from the other in a rectifying column because the particular art to which he directed his claimed invention contained such a column long known as a denitrating tower, employed to separate these two acids when mixed in a waste product in the manufacture of guncotton and nitroglycerin, to recover them and use them again in the manufacture of explosives. The denitrating tower was the old rectifying column depending for its operation on differences in evaporation and condensation of the elements to be separated from the mixture and had the old countercurrent of vapor in the form of steam passing upwardly through broken stones or spheres or marbles to meet the descending flow of mixed nitric acid and sulphuric acid. The nitric acid, being more volatile, was taken up by the steam and the vapors carried off at the top, while sulphuric acid descended to the bottom and was recovered there. But these denitrating towers with the upward countercurrent of steam were, in America, relatively short, being from 8 to 12 feet in height. Pauling claimed (in his United States patent, applied for 1910 and granted 1912 and in his German patent, applied for 1910 and granted 1913) that by increasing their height, and thereby increasing the length.of the counter-current of the vaporous heating medium, higher concentration of nitric acid can be obtained. He was right in this because Sohlman had done it before him (Norwegian and Swedish patents granted Sohlman and Wilson in 1908; and United States patent applied for 1909 and granted 1911).
Sohlman was first to discover and disclose that high concentration can be effected by a lengthened countercurrent. He raised the denitrating tower from between 8 and 12 feet to more than 16- feet and correspondingly lengthened the countercurrent of vapor. He claimed in his patents and proved in practice that by this greater length of current higher concentration of nitrie acid can be obtained— higher, indeed, than Pauling ever obtained. But, being a chemist in the Nobel explosive plants situate in different parts of Europe and being engaged in developing nitrogen fixation from the air as a source of nitrogen and thereby having available highly heated air in quantities so large that air of this character was a by-product of nitrogen fixation plants', he resorted to highly heated air as the vaporous heating medium and employed it in two ways. One, with which we are not presently concerned, was the heating of the denitrating eol- ' umn from the outside. The other, with which we are concerned, was the heating of the denitrating column by a countercurrent of highly heated air on the inside and for the latter he applied for and was granted European and American patents about two years before Pauling. It was after all these long established and highly developed practices in the general fractioning art and in the particular denitrating art that Pauling entered the field. What did he do? He passed from Sohlman’s heated air as a vapor or heating medium to an admixture of heated air and steam and to steam alone as heating media, more available in ordinary plants, and employed a lengthened path in a tower higher than the old denitrating tower; yet a tower no higher and with a path no longer than Sohlman had already claimed and disclosed to the world. Therefore it seems to me that, with our eyes closed by the statute (R. S. § 4923 [Comp. St. § 9469]) to prior foreign practices of separating nitric acid from surphurie acid and, in one operation, concentrating the former in high denitrating towers with long steam countercurrents, the question of the validity of Pauling’s patent turns on the answer to one or, perhaps, to all of these questions: Did Pauling make an invention in taking the one-quarter step from Sohlman’s long countercurrent of heated air as a vaporous heating medium to an equally long countercurrent of mixed heated air and steam as a vaporous heating medium; or in taking the one-half step from Sohlman’s long countercurrent of heated air to an equally long countercurrent of dry steam; or in taking the three-quarter step from Sohlman’s long countercurrent of heated air to an equally long countercurrent of steam, preferably superheated? I think he did not.
Eor this reason I would hold the patent invalid. I am therefore constrained to dissent from the judgment of the court.