and the Physiology of Digestion”, 1838 was medical case-history of patient “Alex St. Martin” who was hit in the gut by buckshot from a shotgun. Doctor William Beaumont treated the patient’s wound that never fully healed, and left a “fistula” hole in the patient’s gut. Dr. Beaumont used this unusual opportunity to observe “Alex St. Martin’s digestive processes. Dr. Beaumont experiments were tying a piece of food to string and inserting it through the hole in Alex St. Martin’s gut. Every few hours, Dr. Beaumont would remove the food and observe how well it was digested. Doctor Beaumont also extracted “gastric juice” from patient Alex St. Martin for chemical analysis. Beaumont used “gastric juice” from St. Martin to “digest” bits of food in cups.
This led to the discovery “digestion” is primarily a chemical process; and, mechanical process of “peristalsis” wave-like movements serve only to push the contents of the canal along. William Beaumont, “Experiments and Observations on Gastric Juice and the Physiology of Digestion”, 1838 is among Harrison Horblit’s , “100 Book’s Famous in the History of Science, 1964.