Duchamp, "The box in a valise", and the readymades. "The box in a valise" is an opera of french artist Marcel Duchamp, of 1941. Actually the opera is in the museum Collezione Peggy Guggenheim di Venezia. This opera is an reproduction in miniature of main artworks of the artist. The artworks of Duchamp calls readymades. The word "readymade" mean something allready do. When an artist take an object and define it "artwork", this object became artwork. This artwork call readymade. Is an ironic logic to feel art, invented by Marcel Duchamp. Duchamp has been, in the world of art, a pioneer of dadaism, in the first years of 1900. But he was also one of the most important artist of 900.