John James Rickard Macleod

Macleod was married Mary W. McWalter. The couple had no children.

During the 1930s, he suffered from acute arthritis that resulted into severe pain and limited movements. With passing time, his health declined further to a point in 1935 when he was admitted to a nursing home.

He breathed his last at his home in Aberdeen on March 16, 1935.

John James Rickard Macleod was born on September 6, 1876 in Clunie, Central Scotland to Robert Macleod and Jane McWalter Macleod. His father was a clergyman. Immediately following his birth, the Macleod family shifted base to Aberdeen, following his father’s transfer.

At Aberdeen, Macleod studied at Aberdeen Grammar School. Following his early education, he enrolled at the Marishchal College at the University of Aberdeen to study medicine. Brilliant in academics, he topped his class in first year.

In 1898, Macleod received his doctorate in medicine. Following his honorary doctorate degree, he received a travelling scholarship which led him to study physiological chemistry at the University of Leipzig, Germany, in 1899. Macleod published his first ever scientific paper in Germany.

Upon returning to Britain in 1900, Macleod started working as a demonstrator in physiology under Sir Leonard Hill at the London Hospital Medical School.

For a year, Macleod and Hill collaboratively studied caisson sickness, a kind of illness that mostly affected people working under high atmospheric pressure of the submerged caissons. The sickness was commonly found in deep-sea divers and underwater tunnel builders. Together the two studied different case history of the disease to determine its cause. They concluded that rapidly coming out from the water caused bubbling of nitrogen in blood and tissues which led to caisson sickness. In 1903, they published a series of articles on the same.

In 1902, Macleod was appointed as a lecturer in biochemistry at the London Hospital Medical School. The same year, he received his doctorate in public health from Cambridge University. He also received the McKinnon research studentship of the Royal Society of Medicine.

In 1903, Macleod moved to the United States. He took up the post of a lecturer in physiology at the Western Reserve University, in Cleveland Ohio. While at Western Reserve University, Macleod pursued his research in caisson sickness. However, he developed an interest in carbohydrate metabolism in relation to diabetes.

In 1903, he was elected as a member of the American Physiological Society. His role play in the organization steadily augmented making him an important member of the organization. By 1921, he was appointed to the chair of the President of the APS.

Macleod’s greatest contribution in his scientific career came in the 1920s decade when he discovered insulin, together with a Canadian physicist Frederic Banting and his student Charles Best. He was a pioneer in the field of carbohydrate metabolism and published a number of works in relation to the field, both before and after the discovery of insulin. Insulin proved to be crucial in the treatment of diabetes. It helped transform severe cases of diabetes into milder ones and also improved management of the condition by preventing diabetic coma and death.