On Petition for Rehearing.
WOOLLEY, Circuit Judge.In disposing of the plaintiff’s petition for rehearing, we shall not enter upon a discussion of the metallurgy of the alloy of the patent and of the alleged high sulfur, low nickel-chromium infringing alloy. Such a discussion cannot easily be confined within reasonable bounds, and, if pursued, would serve no purpose other than to assure the unsuccessful litigant that the court understood the case and to show the grounds upon which it based its decision. We shall do no more than indicate in the briefest way the considerations which moved the court to its judgment.
The complainant again insistently maintains that the approximate similarity of performance of the two metals in point of strength and endurance, is proof that the two metals are identical. But proof of such similarity of performance loses much of its probative force in view of the conceded dissimilarity of chemical composition. As it is conceivable that two metals differently composed as to proportions of the same ingredients may be similar in performance yet be different in fact, the complainant asks us to give to its evidence of performance a value, greater, we think, than it is entitled to receive.
The case turns on the chemical composition o.f the two alloys, considered with reference, not to ingredients, but to proportions of ingredients. If their composition is different (aside from equivalents), the two alloys are different, though their performance be similar, and there is no infringement; for the invention of the patent is found in new proportions of old ingredients, and nowhere else. That is all the patent teaches; it leaves everything else to the skill of the founder.
The chemical composition of the defendant’s alloy is concededly different in proportions from that of the patent, and upon this difference the defendant chiefly relies to distinguish its alloy and to meet the charge of infringement.
Just here the complainant had the task of proving that two alloys, whose ingredients are the same but are in different proportions, are one and the sanie alloy; a task made particularly difficult by the fact that the proportions of one ingredient are not only different but are fundamentally antagonistic. This, as pointed out in the opinion, the complainant did not succeed in proving. This is the central question of the case to which all others are incidental or cumulative, and failing in this, we think the complainant failed to prove infringement.
The apparent mistake of the court in stating that the defendant *717made its metal in cupolas, and in deducing the conclusion that metal thus made could not be Adamite in view of the statement of the patent that Adamite cannot be produced (commercially) in cupolas, does not touch the main question of chemical composition of the two metals, and does not affect the complainant’s lack of proof that the two metals, differently composed, are the same. The question of infringement turns not upon tire appliance or the kind of furnace in which the alleged infringing product is made — for the patent claims teach nothing as to this — but upon the proportions of ingredients with which it is made. Of these, the proportion of sulfur is the critical proportion in this controversy.
In the alloy of the patent the clement of sulfur is present. It is not introduced into the alloy by the patent; it is put there by nature. It is dealt with by the patent because it is there; and being there, it is not treated as an clement having anything to do with the production of the alloy, and it is not used for any purpose. It is considered and treated as an impurity unavoidably present and certainly dangerous, and, for that reason the patent directs that it be reduced to a low minimum. The one thing the patent teaches about sulfur is that it must he gotten rid of, and that it must not be present above a proportion, which, by its own terms, the patent limits to .05.
In the defendant’s alloy, the defendant adds sulfur to what nature supplies. Sulfur is-there because it is put there. It is put there for a purpose, and for a purpose not recognized by the patent and in a proportion denounced by the patent. Because of our belief that the patent involves invention and is valid, and because of its manifest importance to the metallurgical art, we gave a full and a very serious consideration to the complainant’s theory of the defendant’s use of sulfur as a substitute for or an equivalent of any deficiency of the proportion of chromium in the alloy of the patent. But the theory failed in view of the undisputed fact that the defendant began the practice of using sulfur in its alloy in from double to treble the proportion taught by the patent long before the patent was applied for, and consistently pursued it to the bringing of this suit (Exhibit Book 192-225); and in view of the further fact, that while-the defendant used and varied its nickel-chrome content throughout the same period, as it had a right to do, its radical change in that content, complained of as a resort to the nickel-chrome proportions of the patent, was not a change of nickel and chromium in the relation taught by the patent.
As the defendant’s use of high sulfur had long been practiced together with the use of nickel and chromium in varying proportions (sometimes within the proportion of the patent subsequently granted), it was difficult to believe that the defendant’s continued use of sulfur in substantially the same high proportion, was an equivalent of or a substitute for a deficiency in the chromium proportion of the patent, resorted to by the defendant as an expedient or means by which to infringe the alloy of the patent. As this was the very centre of the issue of infringement, we think the complainant failed to prove that Phoenix. Metal is Adamite. "
*718As these are the principal considerations that moved the court to its judgment, we see no occasion for allowing the plaintiff to introduce additional evidence on collateral matters.
The petition for rehearing is denied.