To discover what influence would be exerted on food masticated, swallowed, and mixed with the gastric juice in the usual way, and then withdrawn from the stomach, Dr Beaumont gave St Martin an ordinary dinner of _boiled salted beef, bread, potatoes, and turnips_, with a gill of pure water for drink; and twenty minutes afterwards drew off through the opening about a gill of the contents of the stomach into an open mouthed vial. In this short space of time digestion had already commenced, thus negativing the common notion that an hour elapses before it begins. The vial was now placed in a water-bath, at a temperature of 100°, and continued there for five hours. Examined at the end of that time, the whole contents were found to be dissolved. On then extracting an equal quantity of chyme from the stomach, and comparing it with the solution in the vial, little difference was observable between them, except that the process had been somewhat more rapid in than out of the stomach. But this experiment is remarkable in another point of view, as shewing that _in the short space of twenty minutes enough of gastric juice had been secreted for the entire completion of digestion_. With a view to verify these results, and also to discover the comparative digestibility of different kinds of aliment, Dr Beaumont gave St Martin for dinner eight ounces of _recently-salted lean beef_, four ounces of _potatoes_, some _bread_, and four ounces of boiled _turnips_. After fifteen minutes he withdrew a portion of the contents of the stomach, and found that some of the meat had already been slightly digested. In a second portion, withdrawn at the end of forty-five minutes, fragments of the beef and bread were perceptible, and in a still more advanced state of digestion; the meat was in small shreds, soft and pulpy, and the fluid containing it had become more opaque and gruel-like in appearance. When two hours had elapsed, a third quantity was taken out, at which time nearly all the meat had become chymified and changed into a reddish-brown fluid; but _small pieces of vegetable matter now presented themselves for the first time, but in a state of digestion so much less advanced_ than the meat, that their peculiar structure was still distinctly visible. Some of the second and third portions, put into a vial and treated in the usual way, advanced to complete digestion, as in the other experiment, except that the process was slower, and that a few vegetable fibres remained to the last undissolved; thus confirming the general opinion that vegetables are more difficult of digestion than animal substances.