‎Methodus datae figurae, rectis lineis & curva Geometrica terminate, aut Quadraturam, aut impossibilitatem ejusdem Quadraturae determinandi. (+) Nova Methodus determinandi Maxima & Minima.‎

‎Leipzig, Grosse & Gleditsch, 1683. 4to. Without wrappers. In: ""Acta Eruditorum Anno MDCLXXXIII"", No.III + X (March and October issues). Pp. 81-128 + pp. 417-464 a. 2 engraved plates. (Entire issues offered). Tschirnhaus's papers: pp. 122-124 + pp. 433-437. Some browning as usual.‎

‎First appearance of Tschirnhaus's two papers in which he used infinitisimal methods which were very close to Leibniz's method and where he tried to lay down criteria for rational quadratures in the case of conic, cubic and quadratic curves, papers that led Leibniz to publish his first paper on the differential calculus, the ""Nova Methoda"" in the Acta for 1684 in order to secure his priority over Tschirnhaus concerning the calculus. Leibniz discovered, when he read Tschirnhaus' papers, that Tschirnhaus had here published results showing similarity with Leibniz's invention of the calculus as he had confided to Tschirnhaus earlier, during their Parisian stay, and this without references to Leibniz.The second issue contains an original paper by LEIBNIZ: ""Meditatio Juridico-Mathematica de Interusurio simplice"". Pp. 425-32.‎