Sunday, September 15, 2013
He returned to the United States in 1905 to a faculty position at the Massachusetts Institute of Technology, where he was appointed assistant professor in 1907, associate professor in 1908, and full professor in 1911. In 1912 he left M.I.T. for the University of California at Berkeley where he was dean of chemistry and a professor of physical chemistry. His time in California was interrupted by First World War when Lewis served as a major in the gas service and chemical warfare service.
His first research interest was thermodynamics. He introduced the idea of activity, or the effective concentration of a chemical species in solution. Lewis is best remembered for his valence theory and the eponymous dot structures. Lewis pictured atoms as cubes with the electrons at the corners. We now know that atoms are spherical and their electrons are spread out in orbitals. Lewis also wrote papers on relativity and defined acids and bases as electron acceptors and electron donators respectively. Lewis was the first to produce deuterium oxide (heavy water) using Ernest Lawrence's cyclotron in 1933.
Honors won by Lewis include election in to the National Academy of Science in 1913. Because of his disagreements with Walther Nernst he was never awarded the Nobel Prize although he was nominated 30 times. He was awarded numerous honorary doctorates and membership in Royal Society, the Chemical Society of London and the Indian, Swedish, and Danish Academies of Science.
On March 23, 1946 Lewis died in a laboratory accident involving hydrogen cyanide which some believed was suicide.
Carey, Charles W.; "Lewis, Gilbert N." in American Scientists; Infobase Publishing; 2006
Hildebrand, Joel H.; "Gilbert Newton Lewis; 1875-1946"; National Academy Press; 1958
Gilbert N. Lewis Wikipedia Entry
Sunday, September 8, 2013
While working there she published with Dale and Wilhelm Feldberg a seminal paper in neuroscience describing how acetylcholine serves as neurotransmitter in the voluntary nervous system. Nerve impulses are sent electrically down nerves by changing the permeability of the cell membrane to sodium ions allowing them to rush in. Once the impulse reaches the end it releases acetylcholine into nervous/muscle junction. The actylcholine serves as a chemical messenger quickly diffusing across the interface and causing the muscle to contract. The next year she moved to Girton College, Cambridge, where she remained for four years. When World War II broke out she was scheduled to imprisoned as an enemy national but her colleagues came to her rescue, Dale phoning the Home Office demanding an interview with the Home Secretary. During the war she worked with John Gaddum at the College of the Pharmacological Society in London and in 1948 published another paper with Feldberg demonstrating the presence of acetylcholine using nerves in the brain. Vogt followed Gaddum to the University of Edinburgh, where she was first hired as a lecturer and then as a reader.
In 1952 she was elected to the Royal Society of London, a honor that had only been given to 8 women before her. Vogt's research now centered on amines and their use as a neurotransmitter. Later in her career her work centered on serotonin and its effects in the brain. This research lead to breakthroughs in pharmaceuticals that aids patients with depression.
Honors won by Vogt include a Roylal Medal from the Royal Society in 1981, honorary doctorates from the University of Edinburgh and Cambridge University and honorary membership in the American Academy of Arts and Sciences. She retired due to ill health at the age of 87 and moved to La Jolla, California to live with her sister.
She died on the day after 100th birthday, September 9, 2003.
Anon.; "Marthe Vogt"; The Telegraph; October 3, 2003
Bell, Chris; "Marthe Louise Vogt (1903-2003)"; pA2 Online; Vol.2 Issue 1; retrieved from: pa2online.org
Marthe Vogt Wikipedia Entry
Sunday, September 1, 2013
Folkers is best remembered for his determination of the structure of vitamin B-12, which is also called cobalamin. Vitamin B-12 is unique among the water soluble B vitamins in that it contains an atom of cobalt. Vitamin B-12 is used in DNA synthesis and regulation and also fatty acid synthesis. It is synthesized by bacteria and archea and must be ingested by higher organisms. In humans lack of vitamin B-12 causes pernicious anemia where red blood cells do not develop properly and lyse easily. With Fern Rathe and Edward Kaczka, Folkers isolated the antibiotic cathomycin in 1955.
Honors won by Folkers include the Perkin Medal in 1960 and the Priestly Medal in 1985. Folkers was elected to the National Academy of Science in 1948.
Folkers died on December 7, 1997.
Olson, Robert E.; "Karl August Folkers (1906-1997)"; Journal of Nutrition (2001)131:2227-2230
Shive, William; "Karl Augus Folkers September 1, 1906-December 7, 1997"; Biographical Memiors: National Academy Press
Karl August Folkers Wikipedia Entry