Lazzaro Spallanzani. Engraving of an experiment on digestion carried out by the Italian biologist Lazzaro Spallanzani (1729-99). Spallanzani fed birds with food in perforated containers which had a long piece of string attached. The perforated chambers were recovered after some time by pulling on the string. From his results, Spallanzani concluded that a major part of digestion is the solvent action of fluids in the stomach. Spallanzani named these fluids gastric juice. Spallanzani later repeated the same experiment on himself and helped to overturn the widely-believed theory of Galen (129-199) that digestion was a form of cooking using the heat of the stomach.