Charles Daniel “Dan” Cornwell, 100, passed away on October 13, 2025, in Madison, WI. He was born on December 27, 1924.
According to his obituary, Charles Daniel (“Dan”) Cornwell was born in Williamsport, PA, on Dec. 27, 1924, son of John Gibson Cornwell, Jr., and Anna Moul Cornwell, the latter of Hanover, PA. He was educated in the Williamsport public schools, began college with a year at Dickinson Junior College, and then enrolled at Cornell University.
Dan’s family did not have the financial means to support his enrollment at Cornell, but because his father was an officer in the Navy V-12 College Training Program at Cornell, his father was considered to be a faculty member, and the children of faculty at Cornell got free tuition. When his father was transferred to a different university, he arranged for Dan to receive a Presidential Scholarship, which permitted Dan to continue at Cornell. Dan graduated with a BA, cum laude, in Chemistry.
He went on to earn a Ph.D. in Chemical Physics at Harvard, where he was a student of E. Bright Willson. Except for a letter, Dan never published his thesis, which established the hydrogen-bridged structure of diborane.
His enrollment at Cornell was interrupted by two years in the U.S. Navy, during which he was trained and then served as Electronics Technician H.
In 1950, Dan began a two-year post-doctoral appointment at the University of Iowa in Iowa City. There he met Blanch M. (“Pat”) Haskins, whom he married on Sept. 1, 1951.
They moved to Madison in 1952, when Dan joined the Chemistry faculty of the UW-Madison. His best-known research was a study of the iodine and chlorine resonances in the nuclear quadrupole resonance spectrum of crystalline alkali chloroiodides. This work clarified the nature of the bonding in compounds of this type. Linus Pauling had suggested two possible schemes: one with highly ionic bonds, and the other with the use of d-orbitals of iodine. Dan’s work showed clearly that the former scheme was the correct one.
Dr. Dan Cornwell retired at the end of the spring semester in 1995 and shortly thereafter was designated as an emeritus professor. He had served the UW—Madison Department of Chemistry for 43 years, being first appointed as an instructor in 1953 and rising through the ranks to professor in 1962. During his faculty career, Dan directed 24 doctoral students, 7 master’s students, and two undergraduates, publishing 21 papers on research in his labs. He taught undergraduate physical chemistry, general chemistry, and several graduate courses. The physical chemistry laboratory was a vital part of his teaching, and the excellence of this laboratory grew under his leadership and attention. Dan coauthored two editions of the laboratory text, Experimental Physical Chemistry. Dan participated broadly in the department. He chaired the Physical Chemistry Division for 15 years, leading the division as it grew and diversified. Dan supervised the Electronic Shop for 20 years, guiding its development as a first-rate facility in support of the department’s research program. He was chairman of the new building committee for 14 years. He contributed as a student advisor at both the graduate level and the undergraduate level through the L&S Faculty Advising Service and also served on the Appeals Committee for almost a decade.