§ 821. Express License: Consideration Therefor: Royalties 822. Express License: How Forfeited . . 823. Express License: When Transferable 824. Implied Licenses: License to Use Implied in Favor of Purchaser 825. Implied License: License to Use not Implied from Sales unless the Invention Sold and the Invention Used are Identical . . . 625 826. Implied License: Right to Use Unlimited as to Time, Territory, 827. Implied License: License to Use does not Embrace the Right to Make, nor to Sell as Matter of Traffic. 828. Implied License: License to Use not Restricted by Unknown 829. Implied License: License to Use Implied in favor of Innocent Purchaser at Unlawful Sale, if Vendor afterwards Acquires an Interest in the Patented Invention . . 830. Implied License: License to Use Implied in favor of Purchaser at Unlawful Sale, if Vendor afterwards Compensates the Owner of the Patent for the Infringing Sale . . . 831. Implied License: License to Use Implied from Permission to TREATISE ON THE LAW OF PATENTS. BOOK III. OF LETTERS-PATENT. PRELIMINARY ANALYSIS. § 415. The Patent Privilege Created and Defined by the Grant of Letters-Patent. THAT act of the government by which it confers on an inventor the right to the exclusive public use of his invention is the grant of letters-patent. Prior to this act, whatever right he has in his discovery is vested in him only by the law of nature, and is limited to the free use of his invention by himself, subject to its equally free imitation or re-invention by others. But by the grant of letters-patent his right to use becomes an exclusive one. While his own privileges in reference to the discovery are not enlarged, the privileges which the law of nature confers on other persons are suspended, and pending the term of his patent the whole control over the invention resides in him alone. The issue of a patent is therefore, to all intents and purposes, the creation of a new right in favor of the inventor,-the right to exclude all other persons from the use of the invention, and bestows on him a true monopoly, whose character and extent, as well as duration, the government must specifically define. Of this exclusive privilege the letterspatent are at once the measure and the evidence. By them |