KUPKA FRANTISEK: (1871-1957) Czech Painter and graphic Artist. A pioneer of the abstract art movement. A very fine and interesting A.L.S., `Kupka´, a bold and large attractive signature, one page, 4to, n.p., 25th July 1948, to Monsieur Sides, in French. A very good content letter, Kupka referring to the evolution of painting and to his pioneering role and his predictions made many years ago, and includes a singular definition of abstract, stating `Seuls les évènements m´empêcherent de vous écrire en rentrant du vernissage des R.N. pour vous communiquer ma joie de voir le progres bien notable des exposants et de la repercussion dans le monde de la réforme de l´art plastique, réforme partie de Paris. Bien sur que pour moi particulièrement c´est comme une satisfaction immense d´être dans ma 77eme année, present à ce revirement quand mes - déja si lointaines expositions - je préchais les possibilités nouvelles en peinture une fois séparée de la morphologie de la nature autonome. Trop autonome´ (Translation: `Only events prevented me from writing to you on returning from the opening of the R.N. to communicate to you my joy at seeing the very notable progress of the exhibitors and the repercussion in the world of the reform of plastic art, a reform that started in Paris. Of course, particularly for me, it is like an immense satisfaction to be in my 77th year, present at this turnaround when my - already so distant exhibitions - I was preaching the new possibilities in painting once separated from the morphology of autonomous nature. Too autonomous´ Some small remnants of paper affixed to the verso as a result of former affixing, and a hole to the lower border of the letter because of the letter opening, but not affecting the text or signature. G Fredo Sides (1888-1952) founder of the 1946 first ''Salon des Réalités Nouvelles'' (''Exhibition of the New Realities'') promoting the Abstract art. The 1948 exhibition had 350 exhibitors from 17 different countries.