“A battalion of French soldiers, during the toils and dangers of a campaign, were marching on a certain point on a most oppressive day, and at double the usual speed; their strength was eight hundred men, all hardy, seasoned, and courageous; careless of danger, despising the devil, and little occupied with the thoughts of ghosts and phantasmagoria. On the night of the occurrence in question, the battalion was forced to occupy a narrow and low building at Tropœa, barely calculated to accommodate three hundred persons. Nevertheless, they slept; but, at midnight, one and all were roused by frightful screams issuing from all quarters of the house; and to the eyes of the astonished and affrighted soldiers appeared the vision of a huge dog, which bounded in through the window, and rushed with extraordinary heaviness and speed over the breasts of the spectators. The soldiers quitted the building in terror. Next night, by the solicitations of the surgeon and _chef-de-bataillon_, who accompanied them, they again resumed their previous quarters. ‘We saw,’ says the narrator, ‘that they _slept_. We watched the arrival of the hour of the preceding panic, and midnight had scarcely struck when the veteran soldiers, for the second time, started to their feet. Again they had heard the supernatural voices, again the visionary hound had bestrode them to suffocation. The _chef-de-bataillon_ and myself heard or saw nothing of these events.’” The superstitious thought this spectre to be the devil; but the heat and _carbonic acid gas_ were, I believe, enough for the excitement of the phantasm and the feeling. There can scarcely be imagined a more terrific feeling than this sense of extreme danger, or difficulty, this intense impediment, without a power to avert it. The constant labour of Sisyphus, with his rolling-down stone, and the punishment of Tantalus, would yield in severity to the agony of night-mare, but for its _transient_ existence. It seems to me, that this want of balance between will and power influences human nature so much, that life itself may be termed one long and painful _incubus_. The actions we perform seldom reach the perfection which the will desires. Hence arises that constant dissatisfaction, which even the close approach to perfection of some of the most accomplished professors of art and science cannot avert.