Jean Metzinger see the cubist works in Room 7 and 8. While Pablo Picasso and Georges Braque are generally acknowledged as the founders of the twentieth-century movement that became known as Cubism, it was Jean Metzinger, together with Albert Gleizes, that created the first major treatise on the new art-form, "Du "Cubisme"", in preparation for the Salon de la Section d'Or held in October 1912. "Du "Cubisme"", published the same year by Eugène Figuière in Paris, represented the first theoretical interpretation, elucidation and justification of Cubism, and was endorsed by both Picasso and Braque. "Du "Cubisme"", which preceded Apollinaire's well known essays,
Czech Cubism secessionist designers such as Otto Wagner and Jan Kotěra. Architects such as Josef Chochol and Pavel Janák devised spiritualist philosophies of design and a dynamic ideal of planar form derived from cubist art. As Cubism spread across the European continent in the early 20th century, its greatest impact can be seen today in the Czech Republic. Pyramid and crystal forms were one of the signature principles seen in Czech Cubism which was incorporated in architecture, furniture, and applied arts. The Museum of Decorative Arts in Prague (UPM) uses the House of the Black Madonna as a permanent exhibition space for