Demulso Corporation v. Tretolite Co.

McDERMOTT, Circuit Judge.

This appeal brings on for review an order refusing appellant leave to intervene in an infringement suit brought by appellee, the Tretolite Company, against the Darby Petroleum Corporation, .for a claimed infringement of nine claims of Letters Patent number 1,467,831 owned by the Tretolite Company. The various claims cover a “process for treating petroleum emulsions” and claim the steps of subjecting the emulsion to the action of “a modified fatty acid” to break the emulsion into strata of oil and salt water, heating the mass, allowing it to stand until the oil rises…