being first lighted with ordinary daylight, the lamps above mentioned should be brought in, and the daylight carefully excluded, when an astonishing metamorphosis will take place. The spectators will be hardly able to recognise each other; the furniture of the room, and every other object contained in it, will reflect but a single colour. The flowers will lose their brilliant tints, the paintings will appear as if they were drawn in Indian ink. The brightest purple, the purest lilac, the richest blue, the liveliest green, will be converted into a monotonous yellow. The same change will take place in the countenances of those present; a livid paleness will spread over their faces, whether young or old, and those who are naturally of an olive complexion will hardly appear changed at all. Every one will laugh at the appearance of his neighbour's face, without thinking that he is just as great a subject of laughter to them. If, in the midst of the amusement caused by this experiment, the light of day is admitted at one end of the room, the other end being still lighted with the salt-lamp, every one will appear to be half-illuminated with the livid colour which has caused so much surprise, the other portion of their figure and clothes being of the natural hue. One cheek, for instance, will appear animated with its usual brilliancy, while the other will be that of a corpse; one side of a lady's dress will be brilliant blue or green, as the case may be, the other a colour that it would puzzle an artist to give a name to. The experiment may be varied by admitting the white light through several small holes in the shutter of the room, every luminous spot painting the place where it falls in its natural colours, and the yellow spectators will become spotted with the most singular tints and hues. If a magic-lantern is used to throw on the walls of the room and the clothes of the company any luminous figures, such as those of flowers or animals, they
