The story of Apolinère Enameled not ony records an artist's possible influence on a scientist's discovery, it also marks, like the rest of Duchamp's life and work, a possible influence of science upon an artist. Duchamp said that he acquired the Sapolin sign for Apolinère Enameled and altered the letters. Despite vigorous research and detective work, no other copy of this sign has ever been found. The closest example, discovered by artist Sherrie Levine, was a Sapolin paint sign, with the same bed and similar lettering, but with only a plain black background (see Illustration 3).⁹ We can easily surmise why the bed was given its peculiar form by the paint company. Even though the bed is an "impossible figure," it was obviously rendered this way (without an interruption of the footboard's rungs by the back mattress rail) for greater ease in stamping out the metal form from a template. Duchamp's eye must have seized upon the resulting transition from manufacturing necessity to perceptual absurdity as a good example of how a dimensional representation or individual fixed perspective fails to embody truth in nature, forcing us to actively employ our minds to "see."

Duchamp, throughout his life, insisted that he hated "retinal art," preferring the "non-retinal beauty of grey matter" (Schwarz, 1969a, pp. 18-19). Given his insistence that the reafymades were "completely grey matter," Duchamp continued to be amazed that people stubbornly praised their beauty (as in the tradition of "retinal art")-in direct opposition to his pronouncements (see Hulton, 1993-June 21, 1967, Camfield p. 164¹⁰). In fairness, Duchamp never explained how the cerebral beauty of the "moves," "patterns" and "schematics" that he discerned in both chess and art actually related to his readymades (Schwarz, 1969a, pp. 68-69). He claimed that chess playing and art were unconscious processes, removed from the senses and, therefore, fourth dimensional.¹¹ Literal chess pieces or other objects were three-dimensional, and any schematic or plan that would map the movements of these three- and four-dimensional ideas or objects (visible or invisible) was two-dimensional. Creativity was a ninety-degree hinged rotation, moving from the four-dimensional unconscious idea to the three-dimensional pattern, with the two-dimensioanl schematic map capturing both and acting as an intermediary between the invisible and the visible-a means of bringing forth a discovery as well as memorializing the discovery in a form for others ("spectators") to see with their fourth-dimensional minds (Sanouillet & Peterson, 1973, p. 92).

Duchamp states that his readymades, like Apolinère Enameled, the urinal, bottle rack, snow shovel, etc., are "three-dimensional shadows" of his "fourth-dimensional" Large Glass mechanism (see Illustration 4 outlining the parts of the Glass) ( as cited in Cabanne, 1967, p. 40). The Large Glass (created between 1915-1923) and notes (mostly completed between 1911-1915)¹² were Duchamp's masterpiece, also entitled The Bride Stripped Bare By Her Bachelors, Even. Duchamp often repeated that to understand his project one had to put the Large Glass and the notes together: "the conjunction of the two things (Glass and Notes) entirely removes the retinal aspect that I don't like. It was very logical" (as cited in Cabanne, 1967, pp. 42-43).