The opinion
Gaekett, P. J.,
specially concurring.
As indicated by my concurrence in the dissenting opinion of Judge Bland in the case of Avery v. Chase, 26 C. C. P. A. (Patents) 823, 836, 101 F. (2d) 205, I am in general agreement with his views respecting the so-called doctrine of estoppel in patent proceedings, and the views which he here expresses upon that subject are in harmony *900 with those there expressed by him, and I again concur in such views.
While I do not regard the discussion of estoppel as being essential to the decision, I realize the case was presented to us in a manner which led the majority to think otherwise, and I make no criticism of their action in that respect. I concur in the conclusion reached upon the merits.