Michael Heidelberger (April 29, 1888 – June 25, 1991) was an American immunologist, often regarded as the father of modern immunology. He and Oswald Avery showed that the polysaccharides of pneumococcus are antigens, enabling him to show that antibodies are proteins. He spent most his early career at Columbia University and comparable time in his later years on the faculty of New York University. In 1934 and 1936 he received the Guggenheim Fellowship. In 1967 he received the National Medal of Science, and then he earned the Lasker Award for basic medical research in 1953 and again in 1978. His papers are held at the National Library of Medicine in Bethesda, Maryland. Early life Heidelberger was born in 1888 in New York City to a Jewish couple, David and Fannie Campe Heidelberger, a traveling salesman and a homemaker respectively. An older brother had died shortly after birth; a younger brother, Charles, was born 21 months after Michael. His paternal grandfather, also named Michael, was a German Jew who had emigrated to the United States in the early 1840s. Heidelberger's father had only an elementary school education, and was on the road for six months out of the year selling window curtains. It fell to Heidelberger's mother to take charge of the household and of Michael's education. She had attended a private girls' school in Norfolk, Virginia, and after graduation had stayed with relatives in Germany for a year. Until Michael was twelve, she taught him and his younger brother at home. They attended classical concerts, had to speak German at the table, and were taught French by a nanny during outings to nearby Central Park. Later in life he came to appreciate his early training in languages that were central to scientific discourse during the first half of the twentieth century. Heidelberger decided at age eight that he wanted to be a chemist, for reasons he could never quite articulate or recall, but which he later judged no more than a "pigheaded idea". He experimented at home by mixing medicines and the very basic ingredients included in children's chemistry sets of the time, until he began his formal training in botany, zoology, physics, and chemistry at the Ethical Culture School, a private high school on New York's Upper West Side founded by the Ethical Culture Society, a Humanist religious movement of which his parents were members. He maintained a connection