Riches, Piver & Co. v. Nitrate Agencies Co.

DAVIS, Circuit Judge.

This is an appeal from a decree of the District Court holding invalid United States letters patent No. 1,237,815, issued to George R. Riches and William C. Piver, on August 21, 1917. The patent relates to a process for the manufacture of calcium arsenate, a widely used insecticide, free from “soluble arsenic” or *861“acid salt.” The defenses were invalidity and noninfringement. The District Judge found the patent invalid, but did not pass upon the question of infringement.

The problem in its manufacture is, in the first place, to produee a substance which will kill insects…