"True," said the spectre good-humouredly; "but you can't eject a ghost, you know. You may get a writ of _habeas corpus_, but the English law doesn't supply you with a writ of _habeas animam_. The infamous Jeffreys left me that at least. I am sure the enlightened nineteenth century wouldn't seek to deprive me of it." "Well," said Harry, relenting, "provided you don't interfere with the experiments, or make away with the tea and sugar, I'm sure I have no objection. But if you are anxious to prove to us the existence of ghosts, perhaps you will kindly allow us to make a few simple observations?" "With all the pleasure in death," answered the apparition courteously. "Such, in fact, is the very object for which I've assumed visibility." "In that case, Harry," I said, "the correct thing will be to get out some paper, and draw up a running report which we may both attest afterwards. A few simple notes on the chemical and physical properties of a spectre will be an interesting novelty for the Royal Society, and they ought all to be jotted down in black and white at once." This course having been unanimously determined upon as strictly regular, I laid a large folio of foolscap on the writing-table, and the apparition proceeded to put itself in an attitude for careful inspection. "The first point to decide," said I, "is obviously the physical properties of our visitor. Mr. Egerton, will you kindly allow us to feel your hand?" "You may _try_ to feel it if you like," said the phantom quietly, "but I doubt if you will succeed to any brilliant extent." As he spoke, he held out his arm. Harry and I endeavoured successively to grasp it: our fingers slipped through the faintly luminous object as though it were air or shadow. The phantom bowed forward his head; we attempted to touch it, but our hands once more passed unopposed across the whole face and shoulders, without finding any trace whatsoever of mechanical resistance. "Experience the first," said Harry; "the apparition has no tangible material substratum." I seized the pen and jotted down the words as he spoke them. This was really turning out a very full-blown specimen of the ordinary ghost! "The next question to settle," I said, "is that of gravity.--Harry, give me a hand out here with the weighing-machine.--Mr. Egerton, will you be good enough to step upon this board?" _Mirabile dictu!_ The board remained steady as ever. Not a tremor of the steelyard betrayed the weight of its shadowy occupant. "Experience the second," cried Harry, in his cool, scientific way: "the apparition has the specific gravity of atmospheric air." I jotted down this note also, and quietly prepared for the next observation.