Conrad A. Elvehjem and Perry W. Wilson had done postdoctoral work at Cambridge University, and they had their graduate students busily investigating respiratory processes with manometric methods. They organized a very active seminar group and as a product published a book in 1939 entitled Respiratory Enzymes with Elvehjem and Wilson as editors. They also staged a successful symposium concerned with respiratory enzymes on the Wisconsin campus in 1941 and published the proceedings as a book. Phil Cohen contributed to both volumes. There was good interaction between the biochemistry and physiological chemistry departments, and a number of joint papers came from research collaboration between the two departments. Later members of the group published a book on manometric techniques that went through five editions.

After returning to Wisconsin from his postdoctoral period in England and at Yale, Cohen moved rapidly through the ranks. During 1941–43 he was research associate in physiological chemistry, 1943–45 assistant professor, 1945–47 associate professor, and in 1947 professor. In 1968 he was appointed Harold C. Bradley professor of physiological chemistry. Cohen succeeded Bradley as chairman of physiological chemistry. Bradley had held the chairmanship for many years and was well known locally not only for his university functions but also for his support of skiing before it was a widely accepted sport, and for the accomplishments of his seven sons on the ski slopes and elsewhere. Cohen filled the transition between chairmen seamlessly and continued as chair for twenty-seven years; obviously, he was well accepted by his colleagues. Along the way there were some turbulent years in the medical school, and Cohen aided in smoothing out the problems by accepting the post as acting dean of the medical school for two years. He also served on and chaired the University Committee, the most influential and