In 1937 he went into retirement, but during World War II returned to the University of Lille to replace former colleagues who were part of the war effort.
في 1937 تقاعد , ولكن خلال الحرب العالمية الثانية عاد إلى جامعة ليل ليحل الزملاء الذين شاركوا في الحرب.