Nelson Leonard
1916 – 2006

Faculty Associate in Chemistry Nelson J. Leonard died of cancer at his home in Pasadena on Monday, October 9, barely a month after his 90th birthday. Although Leonard did not join Caltech until 1992, at the ripe old age of 76, “he played a very important role in the life of the division,” says David Tirrell, the McCollum–Corcoran Professor and professor of chemistry and chemical engineering, and division chair. “He mentored many younger faculty members, participated in all our divisional decisions, and was an active member of the Freshman Admissions Committeee for many years.”

Leonard was born on September 1, 1916, in Newark, New Jersey, and earned a BS from Lehigh University in 1937, a BSc as a Rhodes scholar at Oxford University in 1940, and a PhD from Columbia University in 1942. He moved to the University of Illinois at Urbana-Champaign as a postdoc and remained there until he retired in 1986.

A synthetic organic chemist with an interest in biochemistry and plant physiology, Leonard helped develop a method for mass-producing the antimalarial drug chloroquine in time for it to be used in the Pacific Theater during World War II.

With his longtime collaborator Folke Skoog (BS ’32, PhD ’36), a plant physiologist at the University of Wisconsin, Leonard did groundbreaking work on the substances that initiate plant growth and flowering. He also developed a host of the indispensible fluorescent “markers” used to trace DNA, RNA, and other biochemicals within cells. He published more than 400 papers and held eight patents.

At the same time, Leonard was a critically acclaimed singer, soloing with the Chicago, Cleveland, and St. Louis symphony orchestras. After joining Caltech, he served on the board of the Pasadena Symphony.

Leonard is survived by his second wife, Peggy Phelps, whom he married in 1992; daughter Marcia, of Maplewood, NJ; sons Kenneth, of Agoura Hills, CA; James, of Olympia, WA; and David, of Seattle, WA; and seven grandchildren. His first wife, the former Louise Vermey, died in 1987.

A memorial service is planned for November 13 at All Saints Episcopal Church in Pasadena; memorial donations may be made to the Nelson J. Leonard Fund at the Pasadena Symphony. —DS