Leallyn Burr Clapp (1913-1988), professor of chemistry, was born in Paris, Illinois, on October 13, 1913. He graduated in 1935 from Eastern Illinois Teachers College, where he had majored in physics. He taught mathematics at Paris High School for three years while he saved money for graduate school at the University of Illinois where he earned a master’s degree in 1939 and a Ph.D. in 1941. Arriving at Brown in 1941 as instructor in chemistry, he taught year-round during the war for five years. He was promoted to assistant professor in 1945, associate professor in 1949, and professor in 1956. In 1947, at the urging of his department chairman, Paul Cross, Clapp was instrumental in revolutionizing the teaching of chemistry at Brown, when he began teaching organic chemistry to freshmen. In 1959 he became involved in an experiment called the Chemical Bond Approach, and was on leave in the fall of that year to work at Earlham College in Richmond, where he edited the first two editions of CBA, which was intended to revolutionize the teaching of chemistry in the secondary schools with a new approach which encouraged students to learn from their experiments in the laboratory and to think like chemists. He traveled to India, Pakistan, Nigeria, Chile, Korea, Mexico and Uruguay, teaching the CBA system, which he also presented to the numerous secondary school teachers who attended the summer institutes at Brown. Eventually the Chemical Bond Approach was displaced by a rival Chemistry Study Group. Clapp was awarded the Manufacturing Chemists Association College Chemistry Teacher Award in 1973 and the American Chemical Society Award in Chemical Education in 1976. The Department of Chemistry held a symposium in his name on the art of chemistry teaching in October 1982. Students evaluating one of Clapp’s courses concluded that his approach was “coherent, interesting, humorous, effective, enthusiastic” and also “sympathetic and sensitive.” He was constantly available to his students. He had office hours five days a week. He would come in on weekends for review sessions to help his students, and as one of them observed, “At the end of the session, he would thank us for coming, rather than the other way around.” He suffered a massive heart attack on November 28, 1988, and died while lecturing in Metcalf Auditorium.