I have formed a theory as to the _rationale_ of this influence, which I will offer as its probable explanation. We all know that sleep is a process designed by nature for the recuperation of the system after a certain period of activity. In other words, when the various functions have been more or less exercised for their daily allotted time—say seventeen hours—the respective organs need that profound rest which we know as sleep. Now, it is pretty well conceded by physiologists, that electricity stimulates the secretory as well as excretory organs; that it furthers endosmosis and exosmosis—by its electrolytic influence in a physical, by its influence on the nervous system in a catalytic manner, in short, and by virtue of these properties, that it greatly ENHANCES THE CHANGE OF MATTER and incites the various organs to so great an activity as to cause them to perform in a comparatively brief space of time—say an hour, the work of several hours. The natural sequence is obvious: _The want of rest—of sleep, is felt at a correspondingly earlier period._ I offer this as a probable explanation of the immediate or almost immediate disposition to sleep. As to the permanent improvement in sleep, where this has been below the normal standard, it must always be due to the removal of some morbid condition, and thus belongs among therapeutic results, rather than physiological effects. It is true that in many instances of _agrypnia_ we are unable to discover any pathological condition that would account for this symptom; but the probability is that here there is a sluggishness of some one or more of the functions, mental or physical, too obscurely manifested to be discovered by our present means of diagnosis, yet reached and rectified by a mode of electrization that traverses and permeates _every_ portion of the body. If this explanation of the hypnotic effect of the electric bath be not the true one, it is at least—so far as I know—the first attempt at accounting for a phenomenon that has been noticed as a result of even local applications of electricity by many observers, and about the pretty uniform occurrence of which there can be no doubt. With respect to the effect on the TEMPERATURE AND PULSE,