“If the same consequences follow, which followed last June,” said Ezra Jennings—­“if you suffer once more as you suffered then, from sleepless nights, we shall have gained our first step.  We shall have put you back again into something assimilating to your nervous condition on the birthday night.  If we can next revive, or nearly revive, the domestic circumstances which surrounded you; and if we can occupy your mind again with the various questions concerning the Diamond which formerly agitated it, we shall have replaced you, as nearly as possible in the same position, physically and morally, in which the opium found you last year.  In that case we may fairly hope that a repetition of the dose will lead, in a greater or lesser degree, to a repetition of the result.  There is my proposal, expressed in a few hasty words.  You shall now see what reasons I have to justify me in making it.”

He turned to one of the books at his side, and opened it at a place marked by a small slip of paper.

“Don’t suppose that I am going to weary you with a lecture on physiology,” he said.  “I think myself bound to prove, in justice to both of us, that I am not asking you to try this experiment in deference to any theory of my own devising.  Admitted principles, and recognised authorities, justify me in the view that I take.  Give me five minutes of your attention; and I will undertake to show you that Science sanctions my proposal, fanciful as it may seem.  Here, in the first place, is the physiological principle on which I am acting, stated by no less a person than Dr. Carpenter.  Read it for yourself.”

He handed me the slip of paper which had marked the place in the book.  It contained a few lines of writing, as follows:—­

“There seems much ground for the belief, that every sensory impression which has once been recognised by the perceptive consciousness, is registered (so to speak) in the brain, and may be reproduced at some subsequent time, although there may be no consciousness of its existence in the mind during the whole intermediate period.”  “Is that plain, so far?” asked Ezra Jennings.

“Perfectly plain.”

He pushed the open book across the table to me, and pointed to a passage, marked by pencil lines.

“Now,” he said, “read that account of a case, which has—­as I believe—­a direct bearing on your own position, and on the experiment which I am tempting you to try.  Observe, Mr. Blake, before you begin, that I am now referring you to one of the greatest of English physiologists.  The book in your hand is Doctor Elliotson’s human physiology; and the case which the doctor cites rests on the well-known authority of Mr. Combe.”

The passage pointed out to me was expressed in these terms:—­

“Dr. Abel informed me,” says Mr. Combe, “of an Irish porter to a warehouse, who forgot, when sober, what he had done when drunk; but, being drunk, again recollected the transactions of his former state of intoxication.  On one occasion, being drunk, he had lost a parcel of some value, and in his sober moments could give no account of it.  Next time he was intoxicated, he recollected that he had left the parcel at a certain house, and there being no address on it, it had remained there safely, and was got on his calling for it.”