From the NLM Technical Bulletin:

Michael Heidelberger (1888-1991) was one of the fathers of modern immunology and the founder of immunochemistry, the branch of biochemistry that examines the mammalian immune system on a molecular level. His seminal discovery with Oswald T. Avery in 1923 that powerful antigens of pneumococcus bacteria are polysaccharides opened up an expansive new area in the study of microorganisms, and laid a path for a new understanding of infectious diseases, their treatment, and their prevention. The National Library of Medicine® (NLM) is the repository for the Michael Heidelberger Papers, which range from 1901 to 1990. The collection contains correspondence, published scientific articles, laboratory notebooks, diaries, photographs, and examples of Heidelberger's original musical compositions.

As part of its Profiles in Science project, NLM is digitizing and making available over the World Wide Web a selection of the Michael Heidelberger Papers, for use by educators and researchers. This Web site provides access to the portions of the Michael Heidelberger Papers that are now publicly available. Individuals interested in conducting research in the Michael Heidelberger Papers are invited to contact NLM.