In early 1936, an 86 year old Ivan Pavlov lay dying of double pneumonia and asked a student to sit by the bed and record his final physiological sensations. This episode traces how the eldest of 10 children of a village Russian Orthodox priest in Ryazan ended up there. A severe fall from a wall at age seven kept him out of school until 11, and he later left a theological seminary after reading Dmitri Pisarev and Ivan Sechenov, who argued that all brain functions were reflexes. In St. Petersburg he and his wife Serafima lived in deep poverty, staying with friends, and their first son died in early childhood. Pavlov rejected acute vivisection experiments and invented the Pavlov pouch, an isolated section of stomach with its vagus nerve endings intact, which earned him the 1904 Nobel Prize for the physiology of digestion, not for conditioning.

Long term dogs in his lab began salivating at a technician’s footsteps, which Pavlov called psychic secretion and turned into the study of conditional reflexes. In 1994 A. Charles Catania’s review of the original Russian texts found metronomes, harmoniums, whistles, tuning forks, rotating disks and mild shocks, but no clear role for the famous bell. After the revolution H.G. Wells found Pavlov growing potatoes and carrots in his lab courtyard, Lenin granted him double rations and lavish funding, and Pavlov still wrote to Stalin and Molotov protesting persecution of intellectuals. His Nobel fame shielded him. Late in life he studied how stressed dogs shut down, mapping four nervous system types onto the temperaments of Hippocrates and Galen.

• How the Pavlov pouch collected pure gastric juice from healthy dogs that lived in his kennels for years
• Why Pavlov wanted precise stimuli like metronomes rather than a handbell whose volume and pitch vary
• His 1923 lecture saying he would not sacrifice a frog’s hind leg to the communist social experiment
• Transmarginal inhibition, the protective shutdown he triggered with flooding kennels and overwhelming noise
• His influence on John B. Watson, B.F. Skinner, systematic desensitization and Aldous Huxley’s Brave New World