BY HERMAN N.EISEN

WHEN I FIRST MET Michael Heidelberger he was a professor in the Department of Medicine of Columbia University’s medical school, the College of Physicians and Surgeons. He seemed as old as Methusalah, though only 57 as I later realized. It was in 1944, and he seemed ancient not just because I was then so young, in my mid-twenties, a resident and instructor in the medical school’s Pathology Department, but rather, I think, because of his appearance and demeanor. Slender and short, his hair was snow white, his skin a remarkable almond-like color, and he moved and spoke slowly and deliberately, as though in complete sentences.

If scientists are classified according to Isaiah Berlin’s well-known taxonomic scheme for scholars into foxes with diverse accomplishments and hedgehogs having one great accomplishment, Heidelberger seemed the quintessential hedgehog. Though he was highly productive for much of his long life—he lived to be 103—nearly all of his many important contributions stemmed from a steadfast and innovative pursuit of his discovery, with Oswald Avery, that powerful antigens of the highly pathogenic pneumococcus are polysaccharides. This discovery ultimately enabled him and a small group of colleagues to show decisively that antibodies