To describe faithfully the nature of this profound alteration in his character and temperament is not easy, but Dr. Laidlaw summed it up to himself in three words: _Loss of Hope_. The splendid mental powers remained indeed undimmed, but the incentive to use them--to use them for the help of others--had gone. The character still held to its fine and unselfish habits of years, but the far goal to which they had been the leading strings had faded away. The desire for knowledge--knowledge for its own sake--had died, and the passionate hope which hitherto had animated with tireless energy the heart and brain of this splendidly equipped intellect had suffered total eclipse. The central fires had gone out. Nothing was worth doing, thinking, working for. There _was_ nothing to work for any longer!
The professor's first step was to recall as many of his books as possible; his second to close his laboratory and stop all research. He gave no explanation, he invited no questions. His whole personality crumbled away, so to speak, till his daily life became a mere mechanical process of clothing the body, feeding the body, keeping it in good health so as to avoid physical discomfort, and, above all, doing nothing that could interfere with sleep. The professor did everything he could to lengthen the hours of sleep, and therefore of forgetfulness.
It was all clear enough to Dr. Laidlaw. A weaker man, he knew, would have sought to lose himself in one form or another of sensual indulgence--sleeping-draughts, drink, the first pleasures that came to hand. Self-destruction would have been the method of a little bolder type; and deliberate evil-doing, poisoning with his awful knowledge all he could, the means of still another kind of man. Mark Ebor was none of these. He held himself under fine control, facing silently and without complaint the terrible facts he honestly believed himself to have been unfortunate enough to discover. Even to his intimate friend and assistant, Dr. Laidlaw, he vouchsafed no word of true explanation or lament. He went straight forward to the end, knowing well that the end was not very far away.
And death came very quietly one day to him, as he was sitting in the arm-chair of the study, directly facing the doors of the laboratory--the doors that no longer opened. Dr. Laidlaw, by happy chance, was with him at the time, and just able to reach his side in response to the sudden painful efforts for breath; just in time, too, to catch the murmured words that fell from the pallid lips like a message from the other side of the grave.