proceeds to accumulate a head for the next day. And in this manner the potential continues to rise till it has reached so high a point that a tap from some sensational stimulus suffices to start action once more, and we wake. Doubtless we should eventually wake of our own motion if we lay in a sensational vacuum. Practically this event rarely happens, because sensations of some sort or other are always knocking at our mind's door. But a less and less obstreperous one suffices to call us as time wears on. A knock that would have passed unnoticed in the middle of the night easily rouses us in the morning. Once started, the machinery is not long in getting into full swing.
At least this is what happens in the perfectly balanced mind, that character so comfortable to himself, and so disappointing to his more enthusiastic fellows. In ideal equipoise the whole mental energy, potential or actual, ceases approximately together, and starts again together. All of us, however, have probably been abnormal enough at times to have dreamed dreams. Now dreams are interesting things; interesting not only for what they show us, but far more inter-
