On June 6, 1822, an employee of the American Fur Company on Mackinac Island, named Alexis St. Martin, was accidentally shot in the stomach by a discharge of a shotgun loaded with a buck shot from close range that injured his ribs and his stomach. Dr. Beaumont treated his wound, but expected St. Martin to die from his injuries.  Despite this dire prediction, St. Martin survived – but with a hole in his stomach that never fully healed. Unable to continue work for the American Fur Company, he was hired as a handyman by Dr. Beaumont.

By August 1825, Beaumont had been relocated to Fort Niagara in New York, and Alexis St. Martin had come with him. Beaumont recognized that he had in St. Martin the unique opportunity to observe digestive processes. Dr. Beaumont began to perform experiments on digestion using the stomach of St. Martin. Most of the experiments were conducted by tying a piece of food to a string and inserting it through the hole into St. Martin’s stomach. Every few hours, Beaumont would remove the food and observe how well it had been digested. Beaumont also extracted a sample of gastric acid from St. Martin’s stomach for analysis. In September, Alexis St. Martin left Dr. Beaumont and moved to Canada, leaving Beaumont to concentrate on his duties as an army surgeon. Beaumont also used samples of stomach acid taken out of St. Martin to “digest” bits of food in cups. This led to the important discovery that the stomach acid, and not solely the mashing, pounding and squeezing of the stomach, digests the food into nutrients the stomach can use; in other words, digestion was primarily a chemical process and not a mechanical one.

During 1826 and 1827, Dr. Beaumont was stationed at Fort Howard in Green Bay, Wisconsin. In 1828 he was transferred to St. Louis, Missouri. While en route to St. Louis, Alexis St. Martin was ordered to stop at Fort Crawford in Prairie du Chien, Wisconsin, to serve as Dr. Beaumont’s handyman again. In early 1831, Dr. Beaumont conducted another set of experiments on St. Martin’s stomach, ranging from the simple observation of normal digestion to the effects that temperature, exercise and even emotions have on the digestive process.

Beaumont published the account of his experiments in 1833, as Experiments and Observations on the Gastric Juice, and the Physiology of Digestion. He and St. Martin parted ways, with Beaumont eventually going to St. Louis, Missouri, and St. Martin to his home in Quebec province, Canada. Off and on for the next twenty years, Beaumont tried to get St. Martin to move to St. Louis, but the move never occurred.

The Michigan Historical Marker next to the American Fur store reads:

On June 6, 1822, Alexis St. Martin (1804 ~ 1889), a French Canadian voyageur, was accidentally shot in the American Fur Company store located on this site.. Dr. William Beaumont (1786 ~ 1853), The Fort Mackinac post surgeon nursed St. Martin back to health. St. Martin’s wound healed, leaving a permanent opening into his stomach. Through this opening Beaumont compared the digestibility of foods, recorded the temperature of the stomach under different conditions, and extracted and analyzed gastric juices. Beaumont conducted the first of 250 experiments with St. Martin in 1825 in the Officers’ Stone Quarters at Fort Mackinac. Eight years later he published a groundbreaking book on his discovery of the digestive process.