Founded 175 years ago, the National Library of Medicine is the world's largest medical library, with more than 17 million items dating from the 11th century to the present in its holdings. Today it is home to a rich worldwide heritage of objects, from the rarest early medical books to delightful 20th-century ephemera, artifacts, and documentary and animated films. Despite more than a century and a half of classification and cataloging, buried in the...