Our space permits us to touch on it only very lightly. It begins with the time back in the middle of the eighteenth century when a couple of Italian investigators fed sponges inside perforated metal capsules to birds and animals and after recovering and squeezing the sponges demonstrated that the juice which had been soaked up would dissolve meat. The scene then shifts from Italy in the middle of the eighteenth century to our own country at the close of the first quarter of the nineteenth, when a French-Canadian lad, by the name of Alexis St. Martin, was brought in to the frontier army post on Mackinac Island with a gaping gunshot wound in his side. The victim of this accident recovered, but meanwhile a permanent opening into his stomach was left. The army doctor on duty at that post, William Beaumont by name, perceiving the unique opportunity for the study of digestion that was in his hands, employed the young man in his family and for many years studied the digestive process as it went on in his stomach. Next we turn to Russia, where an eminent physiologist, who was still living at last reports, demonstrated by making artificially an opening into the stomach of animals, similar to the one which was made by accident in the case of St. Martin, that the secretion of gastric juice is under the control of the nervous system and, furthermore, that it is under the control of that part of the nervous system which we have already learned regulates the functioning of smooth muscles and glands. Our present knowledge of the nervous system would lead us to expect nothing else, but at the time when these discoveries were made much less was known than now about how the glands, as well as the smooth muscles, are controlled. This Russian investigator showed that it is not necessary for food to enter the stomach in order for gastric juice to be secreted. The enjoyment that accompanies the taking of food into the mouth and so getting its taste and flavor is sufficient to arouse nervous disturbances which excite the gastric glands to activity. On the other hand, unfavorable emotions such as anger, fright, or worry, prevent the discharge of these nervous disturbances and so the glands remain inactive. Hand in hand with this, as we saw in Chapter XII, there will be a complete absence of muscular activity in the stomach; not only does the food fail to be churned, but gastric juice fails to be poured out. No digestion goes on in the stomach nor is the food passed on into the small intestine to be digested there. We can expect nothing else than that indigestion will come on. It appears that in human beings, with their high nervous organization, simple weariness may suffice to hinder the outpouring of the nervous disturbances upon which gastric secretion depends, so that one may not be worried at mealtime, but may be simply overtired and still fail of digesting the food. Fortunately we have means of avoiding