It is usually difficult to arrive at any exact estimate of the time occupied by a dream; but it appears certain that in some instances the succession of images excited during sleep must be exceedingly rapid. Abercrombie, in his work on the “_Intellectual Powers and the Investigation of Truth_,” p. 275, has related several illustrative examples of this fact. In my own experience, one night, as I lay half asleep, I heard the watchman on his round, as usual, examining the fastenings of my front door. At once I began to dream that I was revisiting my father’s house, the home of my childhood. The family were at breakfast in the front parlor, while I walked through the back rooms, examining the doors and the windows, and found it impossible to close and to fasten them. I then took a bath, dressed myself, and walked out into a large garden behind the house. It was filled with tropical trees, of which some were young. The old ones, which I recognized after an absence of thirty years, astonished me by their surprising luxuriance. A lovely, trailing convolvulus, in full bloom, attracted my admiration. After walking for some time I came upon a plum tree which was very small when I left home, and had now reached a height not exceeding twelve feet. This slow growth excited considerable surprise on my part. Returning to the house, I passed the day with my parents, and, at night, undertook to shut up the house, but could not fasten any of the doors or windows. This caused me great uneasiness, for there was a large gypsy camp not far from the east end of the building. My anxiety was presently justified by a noise in the parlor. Hastening to the door, and looking into the room, I saw a large painting disappearing through a hole in the wall next to the encampment of thieves. I immediately cried out, to frighten away the robbers; and was awakened by my wife, shaking me, and asking what was the matter, just in time to hear the watchman walking down the front steps, after the completion of the investigation which had suggested my dream.