in one of the boxes at his girdle, which he opened each time and carefully closed again. By-and-by he seemed to discover some substance which challenged his attention specially, for after a longer observation than usual, he took another instrument from his girdle and observed it more carefully and for a longer time. Then I could see that he called his neighbour, for he looked, and I almost thought that I could see his lips moving, and immediately the other looked up and came towards him. Then the first man handed his observing instrument to the second, who examined very carefully the substance on the little table. Some discussion seemed to follow, an animated conversation as I thought, with certainly a rapid pantomimic accompaniment. Then a very strange thing happened. As the first man stooped towards the table his mask fell off. My glass was so good that I saw it quite plainly come loose at one side, and I saw the man’s hand lifted up to catch it. But before he could reach it, it fell off as I have said. Then in a moment the man’s body became a mass of rapidly seething fluid, and the fluid became a dark cloud of smoke, which spread into the air and disappeared. Just so I had seen Signor Davelli’s body transformed and disappear the day before. The second man at once caught up the mask and stood apparently waiting. Presently a diffused vapour appeared. This became denser and denser, until it assumed the appearance of a seething fluid, as before. This quickly became consolidated and assumed the form of a body, the body of the man who had just disappeared. Then the other man, who was standing ready with the mask in his hand, fitted it again upon the first man, and both men proceeded to examine the substance before them, and to converse, as if nothing had happened to interrupt them. All this time (which, however, was a very short time, although the change was by no means instantaneous, as the like change seemed to be yesterday) the other men worked away without, as far as I could see, taking any notice whatever of what was going on. I exclaimed slightly and started, and this attracted Signor Davelli’s attention. He had been, I think, examining and preparing some instruments. “What do you see?” he said. I answered without taking my eyes from the glass. “A man over there disappeared and appeared again just as you did yesterday.” “Careless wretches!” he said, looking towards the place that I was observing. “I suppose,” I said, “that these substances which they are examining must be very deadly, for his mask fell off just before he disappeared, and I remember you said yesterday that what would kill us only drove you back into space.” “And you infer, I suppose, that if you had been in his place you would have dropped down dead.” “That is what I think,” said I.