The highly interesting and successful attempts to treat diabetes with pancreas extracts deserve a historical review. Some of these experiments were performed long before the isolation and use of insulin by the Canadians Banting, Best, Macleod and Collip in 1921--22. Successful isolation of insulin, known as acomatol and pancreatin, was first carried out before the Canadian research-workers published their results. Particular credit goes above all to Paulesco, Reuter and Zuelzer.