Salmasius, Claudius. De modo usurarum liber. 28 Bl., 891 pp., 46 Bl. Title in red and black. 14.5 x 9.5 cm. Parchment d. C. Leiden, Elzevier, 1639. Willems 488. Kress 545. Goldsmith 697. – First edition of the main work of the French universal scholar Claudius Salmasius (1588-1653) on the law of interest and usury. Salmasius defends in this writing the taking of interest as compensation for the lender. The shift has "almost exclusively determined the direction and content of interest rate theory for more than 100 years and even in today's doctrine there are still some aftereffects of Salmasic teaching" (Sauer & Auvermann catalogue 5, Economy and Society, No. 1283). – A little flaky, frontal joint placed behind the title.