Calvin, October 26, 1961. Melvin Ellis Calvin (April 8, 1911 - January 8, 1997) was an American chemist. He joined the faculty at the University of California, Berkeley in 1937 and was promoted to Professor of Chemistry in 1947. Using the carbon-14 isotope as a tracer, Calvin, Andrew Benson and James Bassham mapped the complete route that carbon travels through a plant during photosynthesis, starting from its absorption as atmospheric carbon dioxide to its conversion into carbohydrates and other organic compounds. In doing so, they showed that sunlight acts on the chlorophyll in a plant to fuel the manufacturing of organic compounds, rather than on carbon dioxide as was previously believed. Calvin was the sole recipient of the 1961 Nobel Prize for Chemistry for what is sometimes known as the Calvin-Benson-Bassham Cycle. He was also the founder and Director of the Laboratory of Chemical Biodynamics and simultaneously Associate Director of Berkeley Radiation Laboratory, where he conducted much of his research until his retirement in 1980. He died in 1997 at the age of 85.