While the subject I intend to discuss in particular is the inhibitory rôle of magnesium salts in its relation to the production of intestinal peristalsis, my chief object is to set forth certain general views I hold now, and have held for many years, on the subject of inhibition in general and the rôle which it plays in the mechanism of all sorts of movements in the animal organism. I shall begin the discussion of the relation of magnesium salts to peristalsis by calling attention to two sets of facts which seem to contradict each other.
It is a well-known and well-established fact that magnesium sulphate, or Epsom salts, is one of the most efficient purgatives. There have been many discussions as to the cause of the action of saline purgatives. According to one view, which has undergone many variations in its details, the cause of the purgation