https://www.historicacanada.ca/en/productions/educational-videos/canada-history-week/canada-history-week-2018-the-discovery-of-insulin
Canada History Week 2018: The Discovery of Insulin | Historica Canada
For many years scientists believed that some kind of internal secretion of the pancreas was the key to preventing diabetes and controlling normal metabolism.
the discovery of insulincanada historyweek