Knorr described the time in Würzburg as most untroubled and most productive period of his life. Reactions of ethyl acetoacetate with numerous other compounds were the main focus of his work there. After the death of Johann Georg Anton Geuther in 1889, the University of Jena was searching for a new full professor and Ernst Haeckel was sent to Würzburg to evaluate whether Knorr was qualified for the position.[1]