PAVLOV, Ivan Petrovich (1849?1936). Three Snapshot Photographs of Ivan P. Pavlov and His Experiments with Dogs. Circa 1921/23. Original black and white photographs (largest 4 ? x 6 ??) depicting Pavlov later in life (presumably in his early seventies) conducting several experiments such as a manometer reading outside of door to dog room, a view of the laboratory as the famous Pavlovian (or classical) conditioning experiment is being conducted with a dog subject in full harness awaiting his meal as his saliva is collected, and a smaller snapshot view (4 ? x 3 ??) of Pavlov speaking with unidentified colleagues. Fine examples of photographs rarely seen on the market. In 1904, Pavlov received the Nobel prize in Physiology of Medicine for his work on the psychological phenomenon of conditioned reflex where he discovered a correlation between digestion and salvation in dogs.