This biography reveals the little-known story of medically qualified research physiologist and biochemist, John Macleod (1876-1935). A child of a Free Kirk minister in rural Perthshire, Macleod was educated at the Grammar School and University in Aberdeen. Rapid career progress in Leipzig, Aberdeen and London culminated in his appointment as Professor of Physiology in Cleveland, Ohio aged only 27. He moved on to similar positions in Toronto then back in Aberdeen. In Cleveland he became an expert on carbohydrate physiology; in Toronto in 1922, he led the four-man team that discovered the world’s first clinically useful insulin. The following year, he was jointly awarded the Nobel Prize in Medicine or Physiology for this life-saving scientific breakthrough, together with colleague, Frederick Banting. The latter unfairly claimed that Macleod had stolen credit for the work.

In a 1982 book, The Discovery of Insulin, Canadian historian Michael Bliss gave a new, detailed interpretation of what had happened in Macleod’s department, concluding that history had underestimated Macleod’s magnificent contributions. Aberdeen-based diabetologist, Michael Williams, went on to produce this detailed account of Macleod’s life and work, originally published in 1993. This refreshed edition, J. J. R. Macleod: Co-discoverer of insulin, adds a description of several interventions over recent years to restore Macleod’s reputation as a scientist whose work contributed to saving hundreds of millions of lives.

About the Author: Dr Michael J Williams (1931-2022) was an Aberdonian educated at the same school and medical school as Macleod; he went on to a career in Aberdeen as a general physician specialising in diabetes.

About the Editor: Dr Kenneth C McHardy (1955-), another Aberdonian, also educated at the same school/medical school, succeeded the author as a diabetes specialist. He assisted with efforts to issue Williams’ original biography and oversaw this revision project from 2020.