This is an appeal from a finding of invalidity of a process patent for pretreating French fried potatoes so they will fry to a substantially even color. The facts and an extensive discussion are found in the opinion of the district court, 236 F. Supp. 601. Without deciding whether the evidence justified a conclusion that the patent claims in suit are invalid because wholly inoperative, we think the evidence supports the court’s holding that they are invalid under 35 U.S.C. § 112 because of the extent of experimentation required of one skilled in the art in order to ascertain their “teaching.”

Affirmed.