concurring.
In agreeing with the result reached here it might be appropriate and of some possible service to the Patent Office and patent bar for me to say, as the judge designated by the court to write the opinion in the Borcherdt case, that there was no desire or intention there to create a new doctrine. In so complex and technical a field as patents, it is extremely difficult to dispose of appeals with the degree of rhetorical preciseness possible in other fields of law without, at least to some degree, indulging in dictum.. If the language in the Borcherdt decision was capable of the interpretation placed on it by the Patent Office, and I do not say that it was not, it is regretted. However, that decision, although factually different, was intended to be based on the principles of the precedents cited therein. There was no intention to hold that a disclosure by an applicant that two or more materials were equivalent for his purposes would necessarily justify the rejection of a claim limited to one of such materials merely on the basis of a showing that another of them was known in the prior art.