He had not the heart to call at the Aburys' that afternoon, though he had promised to do so; and he tortured himself with the thought that Hetty would think him neglectful. He could not call again while the present suspense lasted; and if his worst fears were confirmed he could never call again, except once, to take leave of Hetty for ever. For, deeply as Arthur Greatrex loved her, he loved her too well ever to dream of marrying her if the possible shadow of madness was to cloud her future life with its perpetual presence. Better she should bear the shock, even if it killed her at once, than that both should live in ceaseless apprehension of that horrible possibility, and should become the parents of children upon whom that hereditary curse might rest for a lifetime, reflecting itself back with the added sting of conscientious remorse on the father who had brought them into the world against his own clear judgment of right and justice.

Next morning Arthur went round once more to Professor Linklight's. The professor had promised to read through the paper immediately, and give his opinion of its chances for presentation to the Royal Society. He was sitting at his breakfast-table, in his flowered dressing-gown and slippers, when Arthur called upon him, and, with a cup of coffee in one hand, was actually skimming the last few pages through his critical eyeglass as his visitor entered.

"Good-morning, Mr. Greatrex!" he said, with one of his most gracious smiles, indicative of the warm welcome attended by acknowledged wisdom towards rising talent. "You see I have been reading your friend's paper, as I promised. Well, my dear sir, not to put too fine a point upon it, it won't hold water. In fact, it's a mere rigmarole. Excuse my asking you, Greatrex, but have you any idea, my dear fellow, whether your friend is inclined to be a little cracky?"

Arthur swallowed a groan with the greatest difficulty, and answered in as unconcerned a tone as possible, "Well, to tell you the truth, Mr. Linklight, some doubts have been cast upon his perfect sanity."

"Ah, I should have thought so," the professor went on in his airiest manner; "I should have thought so. The fact is, this paper is fitter for the Transactions of the Colney Hatch Academy than for those of the Royal Society. It has a delusive outer appearance of physical thinking, but there's no real meaning in it of any sort. It's gassy, unsubstantial, purely imaginative." And the professor waved his hand in the air to indicate its utter gaseousness. "If you were to ask my own opinion about it, I should say it's the sort of thing that might be produced by a young man of some mathematical training with a very superficial knowledge of modern physics, just as he was on the point of lapsing into complete insanity. It's the maddest bit of writing that has ever yet fallen under my critical notice."

"Your opinion is of course conclusive," Arthur answered with unfeigned humility, his eyes almost bursting with the tears he would not let come to the surface. "It will be a great disappointment to my friend, but I have no doubt he will accept your verdict."

"Not a bit of it, my dear sir," the professor put in quickly. "Not a bit of it. These crazy fellows always stick to their own opinions, and think you a perfect fool for disagreeing with them. Mark my words, Mr. Greatrex, your friend will still go on believing, in spite of everything, that his roundabout reasoning upon that preposterous square-root-of-Pi theorem is sound mathematics."

And Arthur, looking within, felt with a glow of horror that the theorem in question seemed to him at that moment more obviously true and certain in all its deductions than it had ever done before since the first day that he conceived it. How very mad he must be after all.

He thanked Professor Linklight as well as he was able for his kindness in looking over the paper, and groped his way blindly through the passage to the front door and out into the square. Thence he staggered home wearily, convinced that it was all over between him and Hetty, and that he must make up his mind forthwith to his horrible destiny.

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.