Thanks to all who provided directions to major collections of the work of Duchamp. Our search located an object very much like the one we are studying -- a book cover decorated with velvet and a single foam breast. In each case, the foam has oxidized severely, causing it to become yellow and embrittled. We are determining the composition of the foam so we have a better idea of why it has degraded, and how the remainder of it can best be preserved. Having a comparative object will help. Thanks again. James Martin Director of Analytical Services Williamstown Art Conservation Center