These two white objects by the British artist Rachel Whiteread may seem very simple, but their meaning is significantly more complex and linked to the process by which they were made. Taking old mortuary tables, which have a sloping design that captures body fluids and channels them to a drain at one end, Whiteread made rubber molds of the negative spaces of the tabletops, cast them in bronze, and then used these casts to form the upper surface of her sculptures. Finally, she added sides to create large, tomb-like objects - and painted them a clean, shiny, antiseptic white. In recent years, Whiteread has cast the negative spaces of a library, a condemned house, a water tower on a New York rooftop, and other smaller spaces and objects. She's used industrial materials such as concrete, plaster, and resin; this is her first work in bronze. Her sculptures don't replicate the objects from which they're cast - indeed, it's sometimes difficult to tell what those objects were. But because her sculptures take their form from direct physical contact with the objects, they record their surfaces in detail. The resulting negative impressions strongly evoke their sources. They are like death masks - records of spaces and objects, now gone.