This juice was found, upon experiment, to be endowed, not only with the antiseptic power of preserving the contents of the stomach from putrefaction, but with the property of being a most powerful solvent. Pieces of the toughest meats and bone have been enclosed in perforated metallic tubes, and thrust down the stomach of carnivorous birds, and in the space of about twenty-four hours the meats were found to be diminished, or, in other words, digested to three-fourths of their bulk, while the bones had totally disappeared. Dr. Stevens had recourse to a similar experiment on the human stomach, by means of a perforated ivory ball, and with the same result. The gastric juice of the dog dissolves ivory; and that of a hen has dissolved an onyx, and diminished a golden coin. Not long since, upon examining the stomach and intestines of a man who died in a public-house, he was found to have been a _polyphagous_ animal, since several clasp-knives that he had swallowed were discovered with their blades blunted and their handles consumed. Since these experiments, however, Dr. Montegre of Paris, who was gifted with the faculty of discharging the contents of his stomach at will, has fully proved that this gastric juice, when not in an acid state, is subject to putrefaction when submitted to external animal heat; that this corruption did not occur when an acid prevailed, and saliva intermixed with vinegar was equally free from a similar decomposition. He moreover asserts, that he had recourse to numerous experiments to digest food artificially in this supposed solvent, but without obtaining results similar to those advanced by Spallanzani; and, finally, he found little or no difference between the gastric juice and saliva. This acid, which generally exists in the gastric juice, has been ascertained by Dr. Prout to be the muriatic, both free and in combination with alkalis: while Tiedemann and Gmelin maintain that, in its natural state, no acid is to be met with; but that, when food is commingled, an acid which they consider the acetic acid is produced in considerable quantity.[17]