“I suppose, poor fellow, he is not in a fit state to be reasoned with?”

“On the contrary, like all men with a fixed delusion, he has plenty of intelligence to appeal to on every point, except the one point on which he is wrong.  I have argued with him vainly by the hour together.  He possesses, unfortunately, an acute nervous sensibility and a vivid imagination; and besides, he has, as I suspect, been superstitiously brought up as a child.  It would be probably useless to argue rationally with him on certain spiritual subjects, even if his mind was in perfect health.  He has a good deal of the mystic and the dreamer in his composition; and science and logic are but broken reeds to depend upon with men of that kind.”

“Does he merely listen to you when you reason with him, or does he attempt to answer?”

“He has only one form of answer, and that is, unfortunately, the most difficult of all to dispose of.  Whenever I try to convince him of his delusion, he invariably retorts by asking me for a rational explanation of what happened to him at the masked ball.  Now, neither you nor I, though we believe firmly that he has been the dupe of some infamous conspiracy, have been able as yet to penetrate thoroughly into this mystery of the Yellow Mask.  Our common sense tells us that he must be wrong in taking his view of it, and that we must be right in taking ours; but if we cannot give him actual, tangible proof of that—­if we can only theorize, when he asks us for an explanation—­it is but too plain, in his present condition, that every time we remonstrate with him on the subject we only fix him in his delusion more and more firmly.”

“It is not for want of perseverance on my part,” said D’Arbino, after a moment of silence, “that we are still left in the dark.  Ever since the extraordinary statement of the coachman who drove the woman home, I have been inquiring and investigating.  I have offered the reward of two hundred scudi for the discovery of her; I have myself examined the servants at the palace, the night-watchman at the Campo Santo, the police-books, the lists of keepers of hotels and lodging-houses, to hit on some trace of this woman; and I have failed in all directions.  If my poor friend’s perfect recovery does indeed depend on his delusion being combated by actual proof, I fear we have but little chance of restoring him.  So far as I am concerned, I confess myself at the end of my resources.”

“I hope we are not quite conquered yet,” returned the doctor.  “The proofs we want may turn up when we least expect them.  It is certainly a miserable case,” he continued, mechanically laying his fingers on the sleeping man’s pulse.  “There he lies, wanting nothing now but to recover the natural elasticity of his mind; and here we stand at his bedside, unable to relieve him of the weight that is pressing his faculties down.  I repeat it, Signor Andrea, nothing will rouse him from his delusion that he is the victim of a supernatural interposition but the production of some startling, practical proof of his error.  At present he is in the position of a man who has been imprisoned from his birth in a dark room, and who denies the existence of daylight.  If we cannot open the shutters and show him the sky outside, we shall never convert him to a knowledge of the truth.”