If he had only known at that moment that forty years earlier Professor Linklight had used almost the same words about Young's theory of undulations, and had since used them about every new discovery from that day to the one on which he then saw him, he might have attached less importance than he actually did to this supposed final proof of his own insanity. As Arthur entered his lodgings he hung his hat up on the stand in the passage. There was a little strip of mirror in the middle of the stand, and glancing at it casually he saw once more that awful face--his own--distorted and almost diabolical, which he had learnt so soon to hate instinctively as if it were a felon's and a murderer's. He rushed away wildly into his little sitting-room, and flung his manuscript on the table, almost without observing that his friend Freeling, the rising physiologist, was quietly seated on the sofa opposite. "What's this, Arthur?" Freeling asked, taking it up carelessly and glancing at the title. "You don't mean to say that you've finally written out that splendid idea of yours about the interrelations of energy?" "Yes, I have, Harry: I have, and I wish to heaven I hadn't, for it's all mad and silly and foolish and meaningless!" "If it is, then I'm mad too, my dear fellow, for I think it's the most convincing thing in physics I ever listened to. Let me have the manuscript to look over, and see how you've worked out those beautiful calculations about the square root of Pi, will you?" "Take the thing, for heaven's sake, and leave me, Harry, for if I'm not left alone I shall break down and cry before you." And as he spoke he buried his head in his arm and sobbed like a woman. Dr. Freeling knew Arthur was in love, and was aware that people sometimes act very unaccountably under such circumstances; so he did the wisest thing to be done then and there: he grasped his friend's arm gently with his hand, spoke never a word, and, taking up his hat and the manuscript, walked quietly out into the passage. Then he told the landlady to make Mr. Greatrex a strong cup of tea, with a dash of brandy in it, and turned away, leaving Arthur to solitude and his own reflections.