French Physicist, René-Antoine Ferchault de Réaumur was curious about what happens to food when it goes down the digestive tract. To find out, he fed a crow with chunks of meat in a closed punctured metal capsule. Since the bird excreted an empty capsule, Réaumur then knew that the food in the digestive tract is not mechanically processed, but dissolved by a certain substance. Italian Jesuit priest, Lazzaro Spallanzani took the research further and discovered gastric juice.
