Walter Bradford Cannon

Walter Bradford Cannon, Physiologist, was born in Prairie du Chien, Wisconsin, on October 19, 1871. By the end of his high school career, because of his interest in the biological sciences, he decided to pursue a preparatory course for medical school. However, he was advised to study in the East. So, in 1892, with a cash capital of $180, he entered Harvard College. From then on, through four years of college and four years of Harvard Medical School in Boston, he paid his way with his own earnings.

Cannon started working in the lab during his first year. He volunteered to undertake a research project in addition to his first year medical studies: he suggested that he might find a way to utilize the x-ray as a means of studying the process of digestion in animals. Cannon devised an apparatus in which an animal could be placed above an aperture in a lead-shielded table, under which an x-ray tube was focused. Among his first experiments, Cannon watched the course of a button down a dog’s esophagus. His first report, “The Movements of the Stomach Studies by Means of the Rontgen Rays,” was published in the American Journal of Physiology in 1898.

During his last year in medical school, he was invited to conduct courses in comparative anatomy at Harvard College and Radcliffe College. In 1900 Cannon received his medical degree, joined the American Physiological Society, and became an instructor in the Department of Physiology at the Harvard Medical School. In 1902 Cannon became an assistant professor of physiology; in 1906, he became the chair of the department, a position which he held for thirty-six years, until his resignation in August, 1942.

Cannon's research became more involved at the beginning of the 20th century, particularly at the outset of World War I. He went to Europe with a Harvard medical unit whose duty it became to study, and to combat, shock. He concentrated on traumatic shock, writing in 1915 Bodily Changes in Pain, Hunger, Fear, and Rage. The “sympathico-adrenal system” orchestrates changes in blood supply, sugar availability, and the blood’s clotting capacity. In 1923 his Traumatic Shock postulated that traumatic shock was caused by blood being drained into the dilated capillary region, a phenomenon for which he coined the term exemia. The treatment of shock, he argued, should concentrate on reinstating normal circulation.

Following World War I, Dr. Cannon resumed both research and teaching. He was one the pioneers in study of the autonomic nervous system, isolating at terminals of nerves a chemical product, sympathin, and pointing out its role as mediator of impulses between nerve and muscle. His observations also convinced him that the living body always strives toward a harmonious equilibrium--a state which Dr. Cannon called “homeostatis” in his book, Wisdom of the Body.

Dr. Cannon’s interests were not limited by Harvard’s campus: he accepted exchange professorships, in Paris and in Peking. He was elected to the National Academy of Sciences in 1914. He also served as chairman of the Committee on Physiology of the National Research Council from its inception in 1916 until his death.

During the last years of his life, he suffered intensely from acute dermatitis suspected as having been caused by radiation. He died on October 1, 1945.

Sources: Notable American Unitarians, Am J Public Health