(Berlin, Uppsala & Stockholm, Paris, Almqvist & Wiksell, 1897). 4to. No wrappers as extracted from "Acta Mathematica. Hrsg. von G. Mittag-Leffler.", Bd. 21, pp. 83-97.
First edition. In this paper Poincaré arrives at a new theorem about canonical transformation, and in his later "Methodes Nouvelles", he proved this theorem using a variiational principle of mechanics, known today as the Hamilton principle.
Order-nr.: 39134