Professor David Todd at Pomona College was testing the dehydration of 2-methylcyclohexanol or 4-methylcyclohexanol  and unexpectedly interrupted the alkene distillation midway to have lunch with his secretary, Evelyn Jacoby. After lunch, he continued his distillation but kept the early products separate from the completed ones.  The analysis showed two different alkene ratios.  The reaction products and pathways to the products seem to have changed over time.  Dr. Todd called this phenomenon the “Evelyn effect.”