“You think of me too highly,” returned the other; “though I prefer cases, as you know, in which the spirit is disturbed first, the body afterwards.”

“I understand, yes.  Well, I have experienced a curious disturbance in—­not in my physical region primarily.  I mean my nerves are all right, and my body is all right.  I have no delusions exactly, but my spirit is tortured by a calamitous fear which first came upon me in a strange manner.”

John Silence leaned forward a moment and took the speaker’s hand and held it in his own for a few brief seconds, closing his eyes as he did so.  He was not feeling his pulse, or doing any of the things that doctors ordinarily do; he was merely absorbing into himself the main note of the man’s mental condition, so as to get completely his own point of view, and thus be able to treat his case with true sympathy.  A very close observer might perhaps have noticed that a slight tremor ran through his frame after he had held the hand for a few seconds.

“Tell me quite frankly, Mr. Pender,” he said soothingly, releasing the hand, and with deep attention in his manner, “tell me all the steps that led to the beginning of this invasion.  I mean tell me what the particular drug was, and why you took it, and how it affected you—­”

“Then you know it began with a drug!” cried the author, with undisguised astonishment.

“I only know from what I observe in you, and in its effect upon myself.  You are in a surprising psychical condition.  Certain portions of your atmosphere are vibrating at a far greater rate than others.  This is the effect of a drug, but of no ordinary drug.  Allow me to finish, please.  If the higher rate of vibration spreads all over, you will become, of course, permanently cognisant of a much larger world than the one you know normally.  If, on the other hand, the rapid portion sinks back to the usual rate, you will lose these occasional increased perceptions you now have.”

“You amaze me!” exclaimed the author; “for your words exactly describe what I have been feeling—­”

“I mention this only in passing, and to give you confidence before you approach the account of your real affliction,” continued the doctor.  “All perception, as you know, is the result of vibrations; and clairvoyance simply means becoming sensitive to an increased scale of vibrations.  The awakening of the inner senses we hear so much about means no more than that.  Your partial clairvoyance is easily explained.  The only thing that puzzles me is how you managed to procure the drug, for it is not easy to get in pure form, and no adulterated tincture could have given you the terrific impetus I see you have acquired.  But, please proceed now and tell me your story in your own way.”

“This Cannabis indica,” the author went on, “came into my possession last autumn while my wife was away.  I need not explain how I got it, for that has no importance; but it was the genuine fluid extract, and I could not resist the temptation to make an experiment.  One of its effects, as you know, is to induce torrential laughter—­”