Frederick Banting realized that this procedure would destroy the trypsin-secreting cells but not the insulin. Once the trypsin-secreting cells had died, insulin could be extracted from the islets of Langerhans. Banting discussed this approach with J. J. R. Macleod, Professor of Physiology at the University of Toronto. Macleod provided experimental facilities and the assistance of one of his students, Charles Best. Banting and Best, with the assistance of biochemist James Collip, began the production of insulin by this means. As the experiments proceeded, the required quantities could no longer be obtained by performing surgery on living dogs. In November 1921, Banting hit
Frederick Banting eyesight. Banting successfully joined the army in 1915 and spent the summer training before returning to school. His class was fast-tracked to get more doctors into the war and so he graduated in December 1916 and reported for military duty the next day. He was wounded at the Battle of Cambrai in 1918. Despite his injuries, he helped other wounded men for sixteen hours, until another doctor told him to stop. He was awarded the Military Cross in 1919, for heroism. Banting returned to Canada after the war and went to Toronto to complete his surgical training. He studied orthopedic