ened in a case where, as here, the prior art relied upon to invalidate the patent was considered and rejected by the patent office.”
We think that no good purpose could be served in an attempt on our part to analyze and dissect the voluminous exhibits relied upon as prior art. They consist of many patents, none of which were ever reduced to practice so far as we are aware, as well as numerous articles and publications prepared by the patentees and other high-ranking members of the dental profession. An analysis of such art is in a field for experts, not laymen. The District Court heard the explanatory testimony of experts and found that the patents were not anticipated by the prior art. We find no reason to disagree; certainly we cannot say that such a finding is clearly erroneous. In this connection, defendants contend that all the prior art was not cited in the prosecution of the applications which culminated in the granting of the patents in suit. Four publications are included in this category, an article by Grove and Grove, two articles by Stephan and one by Dr. Kesel. A study of these articles reveals nothing which reflects upon the validity of the patents; in fact, we suspect they were not cited by the Examiner because of immateriality.
In addition to the presumption attaching to the grant and the findings of the District Court, there are other criteria which support patentable invention. As already noted, none of the prior art was reduced to commercial practice and this in spite of the long-felt want for a dentifrice which would aid in the elimination of tooth decay. The statement of this Court in Ric-Wil Co. v. E. B. Kaiser Co., 179 F.2d 401, 404, appears to be appropriate:
“The prior art upon which defendant now lavishes its praise was apparently permitted to lie dormant until the exigency, created by a suit for infringement, required its resurrection.”
It is true, as defendants point out, that prior art, even though not reduced to practice, may be utilized to anticipate. Even so, however, we think its use for that purpose under existing circumstances is greatly impaired. Also as noted, defendants concede the utility of the product manufactured in accordance with the teachings of the Kesel and Wach patents. Not only were their teachings reduced to practice, but the product enjoyed great commercial success. Some thirty dentifrice manufacturers have been licensed under these patents, including such leaders in the industry as Colgate, Ipana, Pepsodent, Kolynos, Walgreen and Amurol. Another significant factor relative to the prior art is the derogatory appraisement which Dr. Hen-schel made of it during the course of the proceedings which resulted in the issuance of his patent.
In our view, the most serious question arises from defendants’ contention that defendants’ alleged infringing products were on the market long before Kesel’s disclosure in the Patent Office upon which his claims were allowed. If this contention is sound, it means, of course, that Henschel was entitled to priority over Kesel, which would result in the invalidation of the latter’s claims. As already shown, both the Wach and Henschel patents issued February 20, 1951, while the Kesel patent did not issue until December 16, 1952. The important date on the question of priority, however, is that of disclosure, not that of issuance.
Both Kesel and Wach stem from an original application, Serial No. 721,156, filed January 9, 1947, in the names of Kesel, Wach, O’Donnell and Kirch (referred to as the parent application). Some claims called only for dibasic, others for urea plus dibasic. The Patent Office held that there were claims to more than one species and required the applicants to make an election. As a result, Kesel claimed to be the inventor of the dibasic ammonium phosphate dentifrice, and Wach, the inventor of the combination of such dibasic and urea.