24 hours, the meat which had been withdrawn from the stomach after digestion had commenced, were, with the exception of a piece of meat that had not been masticated, converted into a thickish pulpy mass of a reddish-brown colour: the meat in the warm gastric juice was also digested, though less perfectly, while that in the cold gastric juice was scarcely more acted on than the meat in the water, which was merely macerated. Dr. Beaumont now exposed these two phials containing the meat in cold gastric juice, and meat in water, to the heat of the water bath for 24 hours, and the gastric juice, which when cold had no power on the meat, now digested it; while the meat in the water underwent no change, except that towards the end of the experiment, putrefaction had commenced. The antiseptic properties of the gastric juice were fully demonstrated in several other experiments. Various philosophers, in idle disquisitions, have endeavoured by the most absurd hypotheses to determine what is the natural food of man, and to show that he is not created omnivorous. The comparison between our species and animals confutes these vain theories. The masticatory and digestive organization of man assigns to him an intermediate rank between carnivorous and herbivorous creatures. The teeth may be said by their figure and construction to bear a relation with our natural food. The teeth of flesh-eating animals rise in sharp prominences to seize and lacerate their prey, and those of the lower jaw shut within those of the superior one. The herbivorous animals are not armed with these formidable weapons, but have broad flat surfaces with intermixed plates of enamel, that they should wear less rapidly in the constant labour of grinding and triturating. In the carnivorous, the jaws can only move backward and forward; in the herbivorous their motion is lateral, as observed in the cow when chewing her cud. Beasts of prey tear and swallow their food in masses, while in others it undergoes a careful communition before it is transmitted to the stomach. The teeth of man only resemble those of carnivorous animals by their enamel being confined to their external surface, while in the freedom of the motion of the jaws from side to side they partake of the conformation of the herbivorous. The teeth and jaws of man are in all respects more similar to those of monkeys than any other animals; only in some of the simiae the canine teeth are much longer and stronger, and denote a carnivorous propensity.