Louis Brandeis

“ For the method of so retarding evaporation the Barber Company acquired the process patent sued on, and seeks to use it to secure a limited monopoly in the business of producing and selling the bituminous material for practicing and carrying out the patented method. The company does not itself engage in road building, or compete with road contractors. It does not seek to make road builders pay a royalty for employing the patented method. ”

“ It does not grant to road builders a written license to use the process. [2] But it adopts a method of doing the business which is the practical equivalent of granting a written license with a condition that the patented method may be practiced only with emulsion purchased from it. For any road builder can buy emulsion from it for that purpose, and whenever such a sale is made, the law implies authority to practice the invention. On the other hand the Barber Company sues as contributory infringer a competing manufacturer of this unpatented material who sells it to a road builder for such use. ”

“ They supply merely one of the several materials entering into the combination; and on that commodity they have not been granted a monopoly. Their attempt to secure one cannot be sanctioned.' 283 U.S. 27, at pages 34, 35, 51 S.Ct. ”