It was about this time that I began to lose my temper. It was after three o'clock when we got to that point, and I was getting very tired, and, strange as it may appear, curiously doubtful about my own existence. I had for some time been coming to the conclusion that he did not quite believe in my reality; and after he had dismissed my account of the black races as being untrustworthy, he said, half to himself, that quite probably I was nothing more than an hallucination, a thought projection of his own mind. And after that I got more and more annoyed--partly, I think, because I had a kind of haunting fear that what he had said might be true. When you have been talking to a spirit for over three hours in the middle of the night, you are liable to doubt anything. But it was foolish of me to try and prove to him that I had a real objective existence, because obviously it wasn't possible. I tried to touch him, and my hand went through him as if he were nothing more than a patch of mist. Then I got right out of bed and moved various articles about the room, but, as he said, that proved nothing, for if he had an hallucination about me, he might equally well have one about the things I appeared to move. And then we drifted into a futile argument as to what I looked like. It began as a sort of test, to try if my own conception of myself tallied with his; and it didn't--not in the very least. In fact, the description he gave of me would have done very well for the typical goblin of fairy-tale, which, as I told him, was precisely how _I_ saw _him_. He laughed at that, and told me that, as a matter of fact, he had no shape at all, and that my conception of him proved his description of me was the correct one, because I had visualised myself. He said that he would appear to me in any shape that I happened to be thinking of, and naturally I should be thinking of my own. And I could not disprove a thing he said; and when I looked at myself in the cheval glass, I was not at all sure that I did not look like the traditional goblin. Well, I assure you that I felt just then as if the one possible way left to demonstrate my sanity, my very existence, was to lose my temper; and I did it very thoroughly. I raved up and down the room, knocked the furniture about, chucked my boots through him, and called him a damned elemental. And although it had no more effect upon him than if I had been in another world--as I suppose in a sense I actually was--that outbreak did help to restore my sanity. Perhaps you may have noticed that if a man is worsted in an argument he invariably loses his temper? It is the only means he has left to convince himself that he is right. Well, my temper did that for me on this occasion. I could not prove my existence to that confounded spirit by any logic or demonstration, but I could prove it to myself by getting angry. And I did.