ACID. The harshness of the word underscores its negative properties, suggesting burning sensations or blistering skin. Yet paper, harmless and everyday useful, contains enough acid literally to burn itself up. This is the message of Slow Fires, a documentary film that aired on public television stations in the United States in 1987, and more recently of Turning to Dust, a Canadian film broadcast in March 1990 as part of a series called The Nature of Things. This was also the message delivered to the United States Congress on March 3, 1987, helping to pave the way for large increments of federal funding to begin to solve the problem. And this was the message I received when I stumbled onto the Smithsonian Institution Libraries' 1,800-volume collection of nineteenth-century world's fair publications. The yellowed, brittle text of President Ulysses S. Grant's Message to Congress about the 1876 Philadelphia Centennial Exposition bore no resemblance to the flexible, white paper that carried St6phen FlachetMony's fine line drawings of furniture, silver, and glass displayed at the 1834 Exposition des produits de l'industrie francaise in Paris. Because it contains high levels of acid, the paper used after 1850 in books, journals, newspapers, and other printed materials sitting in the stacks of research libraries, along with the manuscripts, records, and other documents housed in archives, is slowly drying out, turning brown, cracking, and crumbling. The process has been hastened by the effects of poor storage conditions and decades of environmental pollution, espe-