Martin David Kamen

27 AUGUST 1913 * 31 AUGUST 2002 IN FEBRUARY 1940, Martin Kamen, working together with a graduate student colleague named Sam Ruben at the Berkeley Radiation Laboratory, looked for and found a long-lived radioisotope of carbon. The discovery of this material, C-14, immediately revolutionized biochemistry with its potential for tracing the path of carbon metabolism in living organisms. Four years later, early in 1944, Martin Kamen, who was by this time working on the Manhattan Project, was dismissed from his Berkeley position as a security risk. A talented musician, he had been overheard talking to officials of the Russian consulate whom he had met through his concert playing. These two events were to dog Kamen for much of his life; the first because of the obvious importance of the science and the expectations for personal success that it implied, and the second because of its sinister tone and the opportunities it was to deny him. Indeed, Kamen was forced to spend a disproportionate amount of his time in the late 1940s and 1950s clearing his name from the scurrilous attacks of irresponsible journalists. That he ultimately triumphed speaks volumes about his nature. Martin Kamen was born in Toronto in 1913, the child of poor Russian immigrants. His parents had actually moved to Chicago a few years earlier, where his father had opened a photography studio, but his mother had gone back to Toronto, where relatives could help when Martin was born. When he was three months old, he and his mother returned to Chicago. It was realized early that Martin had a natural talent for music, and he was soon proclaimed a child prodigy, a title with which he was not at all comfortable. He certainly could have been a successful professional musician-he had settled on the viola-but a variety of circumstances propelled him in another direction. When he was a declared English major at the University of Chicago at the start of the Great Depression, his father suggested he take chemistry, a practical subject that he felt might offer the prospects of earning a living. In fact, Martin turned out to be good at the subject and stayed on at Chicago to earn a Ph.D. in physical chemistry. He had a scholarship, awarded in part, he said, for playing first viola in the university orchestra. He further supported himself as a jazz fiddler in various Chicago night spots. He wrote about many of these events in his absorbing autobiography Radiant Science, Dark Politics (1985), and in a reminiscence for the Annual Review of Biochemistry (1986). The importance of the discovery of C-14 cannot be overstated. It led directly to two Nobel Prizes, one to Melvin Calvin in 1961 for working out the path of carbon dioxide assimilation during photosynthesis, and another to Willard Libby in 1960 for developing a method for determining the age of carbon-containing artifacts from the past on the basis of how much C-14 they contained. Indeed, it was Kamen and Ruben and their colleagues who first undertook experiments to trace the path of carbon during photosynthesis. Their early experiments were with C-Il, a radioisotope with a half-life of only twenty-one minutes. This was too short an existence for their experiments to be fruitful, and it was soon realized that a long-lived isotope was essential. C-14 turned out to have a half-life of about 5,600 years, more than enough for biochemical experimentation and, as it developed, very appropriate for dating past archaeological and other events. During this period Kamen made a host of other discoveries that, were it not for the celebrity of the C-14 discovery on the one hand and political troubles on the other, would have insured his eminence on their own. These included the discovery that oxygen incorporated into sugars during photosynthesis does not come from carbon dioxide, as had been supposed, but originates instead from water molecules. Kamen also discovered that carbon dioxide assimilation can occur in the dark, the energy from light being introduced at a stage of the process different from that of carbon dioxide fixation. …

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