Gilbert N. Lewis


Gilbert N. Lewis : biography

October 23, 1875 – March 23, 1946

In 1926, he coined the term "photon" for the smallest unit of radiant energy (light). Actually, the outcome of his letter

to Nature was not what he had intended. In the letter, he proposed a photon being a structural element, not energy. He insisted on the need for a new variable, the number of photons. Although his theory differed from the quantum theory of light introduced by Albert Einstein in 1905, his name was adopted for what Einstein had called a light quantum (Lichtquant in German). 

Later years

Over the course of his career, Lewis published on many other subjects besides those mentioned in this entry, ranging from the nature of light quanta to the economics of price stabilization. In the last years of his life, Lewis and graduate student Michael Kasha, his last research associate, established that phosphorescence of organic molecules involves emission of light from one electron in an excited triplet state (a state in which two electrons have their spin vectors oriented in the same direction, but in different orbitals) and measured the paramagnetism of this triplet state. Phosphorescence and the Triplet State

In 1946, a graduate student found Lewis’s lifeless body under a laboratory workbench at Berkeley. Lewis had been working on an experiment with liquid hydrogen cyanide, and deadly fumes from a broken line had leaked into the laboratory. The coroner ruled that the cause of death was coronary artery disease, but some believe that it may have been a suicide. Berkeley Emeritus Professor William Jolly, who reported the various views on Lewis’s death in his 1987 history of UC Berkeley’s College of Chemistry, From Retorts to Lasers, wrote that a higher-up in the department believed that Lewis had committed suicide.

If Lewis’s death was indeed a suicide, a possible explanation was depression brought on by a lunch with Irving Langmuir. Langmuir and Lewis had a long rivalry, dating back to Langmuir’s extensions of Lewis’s theory of the chemical bond. Langmuir had been awarded the 1932 Nobel Prize in chemistry for his work on surface chemistry, while Lewis had not received the Prize despite having been nominated 35 times. On the day of Lewis’s death, Langmuir and Lewis had met for lunch at Berkeley, a meeting that Michael Kasha recalled only years later.Coffey (2008): 310-15. Associates reported that Lewis came back from lunch in a dark mood, played a morose game of bridge with some colleagues, then went back to work in his lab. An hour later, he was found dead. Langmuir’s papers at the Library of Congress confirm that he had been on the Berkeley campus that day to receive an honorary degree.

Personal life

On June 21, 1912, he married Mary Hinckley Sheldon, daughter of a Harvard professor of Romance languages. They had two sons, both of whom became chemistry professors, and a daughter.