CONTRIBUTORY INFRINGEMENT OF PATENT RIGHTS. UNDER the statute of the United States which enacts that the patentee for a new and useful invention shall have the ex- clusive right to make, use, and vend his invention or discovery (Rev. Stat. U. S., sec. 4884), cases without number have been disposed of by the Federal courts. Sitting in equity, the courts in terms enjoin the infringer of patent rights from " directly or indirectly" making, using, selling, etc., the subject-matter exclu- sively controlled by virtue of the patent grant; and, generally speaking, no argument need be wasted in support of the proposi- tion that no man may do indirectly that which he may not do directly. But under conditions growing out of one well-established rule of patent law there have appeared several instances where, at first glance, it seemed that persons charged with individual in- fringement of patent rights might escape the legal consequences of their acts. The patent grant rests upon, and is the expression of, a contract between the inventor of new and useful improvements in the arts, on the one hand, and the public, on the other ; whereby, in con- sideration of the disclosure to the established agent of the public — the Commissioner of Patents — of a full and accurate descrip- tion of the newly invented improvement, a monopoly of manufac- ture, sale, and use of the invention is granted to the inventor for a term of years, with a remainder, as it were, in fee to the public.^ For this reason it becomes indispensable to the public to have a distinct recital in the grant, of the nature and limitations of the subject-matter which is thus secured to the patentee. There- fore, the statutes require the applicant for patent to set forth as part of his patent grant the exact metes and bounds of the substance he claims to be his invention and for which he is entitled to the monopoly.^ This statement is the patent claim- Usually the claim is for a new combination of correlated parts, as • Grant v. Raymond, 6 Pet. 218. 2 Revised Statutes of the U. S., sec.
