(dissenting).
I am willing to agree with my associates in regarding the question of invention as one of fact until advised to the contrary by the Supreme Court. I would, however, like to point out that although the question is treated as one of fact in the majority opinion in Goodyear Tire & Rubber Co. v. Ray-O-Vac Co., 321 U.S. 275, 64 S.Ct. 593, 88 L.Ed. 721, decided in 1944, three of the dissenting Justices in that case indicated in a footnote appended to their opinion that on the authority of Mahn v. Harwood, 112 U.S. 354, 358, 5 S.Ct. 174, 6 S.Ct. 451, 28 L. Ed. 665, decided in 1884, and cases collected in United States Supreme Court Digest (West 1943), Patents, Vol. 11, «=>16-74, they viewed the question as one of law.
Furthermore, I agree with my associates’ analysis of Amory’s contribution. That is to say, seeing nothing new in the warp threads which he used, in the way those threads were woven with his filling,threads, in a filling thread consisting of a hard twisted core wrapped with slack twisted and undrafted artificial fibers, or in his napping process, I conclude that Amory’s contribution was the use as wrapping for his filling threads of a large proportion of relatively coarse artificial fibers a substantial portion of which were uniformly IV2" %" long, i.e., staple rayon, a known material, whereas the prior art had used for that purpose artificial fibers of short but random lengths and denier, i.e., garnetted rayon, another known material. Thus I conclude, as my associates do, that Amory’s contribution .consisted in the substitution of one known material for another in an old combination. My disagreement in this case stems from my inability under these circumstances to reconcile the finding of invention made below with the rule of law enunciated by the Supreme Court in 1850 in the case of Hotchkiss v. Greenwood, 11 How. 248, 13 L. Ed. 683, since in my view Amory’s substitution of materials did not produce a rayon blanket differing in kind or species from those which had preceded it, (Smith v. Goodyear Dental Vulcanite Co., 93 U.S. 486, 23 L.Ed. 952, decided in 1876, see also our opinion on rehearing in Grant Paper Box Co. v. Russell Box Co., 154 F.2d 729); but only produced a better rayon blanket than had previously been known.”
The rule established by the Hotchkiss and Smith cases, supra, which over the years since its enunciation has been many times applied, is that it does not amount to invention to substitute one known material for another in an old combination when the new product resulting differs from the old only in that it possesses desirable qualities or characteristics of the old in an accentuated form or to a greater degree, but that such substitution may amount to invention if the new product is an improvement over the old for the reason that it differs therefrom in kind or species having new uses, functions or properties. Thus in the Grant Paper Box Co. case supra, we were able to find invention because the patentee’s laminated paper not only differed in degree from the laminated papers of the prior art in that it was thinner and more highly moisture-vapor proof, but also differed from them in kind in that it could be flexed without cracking and could be written or printed upon, — qualities not possessed in any appre-*165dable degree by preceding papers of its type.
Hence at the threshold of cases of this sort a distinction must be drawn between differences in degree and differences in kind, and only when a difference falling in the latter category is found to exist does the question of invention arise. From this it follows that we do not come to the question of patentable invention in the case at bar until we are able to discover something in addition to a difference in degree between the Amory blanket and the rayon blankets of the prior art.
Obviously differences in degree cannot be distinguished from differences in kind with anything even remotely approaching mathematical nicety. For this reason the distinction is unsatisfactory in that each case must be decided on its own facts as it arises and in close cases like the present differences of opinion are normally to be expected. As I see it, the Amory blanket differs from the rayon blankets which preceded it only in that it is better in appearance, sheds less in laundering, and is not only warmer, but is also more evenly warm throughout, because it possesses a loftier and more homogeneous nap. Hence' I conclude that Amory’s substitution of materials produced a rayon blanket differing from earlier ones in degree of excellence only— that Amory’s substitution only accentuated desirable qualities possessed to less degree by the rayon blankets of the prior art — and thus that his patent is invalid under the rule of Hotchkiss v. Greenwood, supra.