`You will understand directly why I speak with that reservation. Let us go on. You are not aware of ever having taken opium. At this time, last year, you were suffering from nervous irritation, and you slept wretchedly at night. On the night of the birthday, however, there was an exception to the rule -- you slept soundly. Am I right, so far?'

`Quite right!'

`Can you assign any cause for the nervous suffering, and your want of sleep?'

`I can assign no cause. Old Betteredge made a guess at the cause, I remember. But that is hardly worth mentioning.'

`Pardon me. Anything is worth mentioning in such a case as this. Betteredge attributed your sleeplessness to something. To what?'

`To my leaving off smoking.'

`Had you been an habitual smoker?'

`Yes.'

`Did you leave off the habit suddenly?'

`Yes.'

`Betteredge was perfectly right, Mr. Blake. When smoking is a habit a man must have no common constitution who can leave it off suddenly without some temporary damage to his nervous system. Your sleepless nights are accounted for, to my mind. My next question refers to Mr. Candy. Do you remember having entered into anything like a dispute with him -- at the birthday dinner, or afterwards -- on the subject of his profession?'

The question instantly awakened one of my dormant remembrances in connection with the birthday festival. The foolish wrangle which took place, on that occasion, between Mr. Candy and myself, will be found described at much greater length than it deserves in the tenth chapter of Betteredge's Narrative. The details there presented of the dispute -- so little had I thought of it afterwards -- entirely failed to recur to my memory. All that I could now recall, and all that I could tell Ezra Jennings, was that I had attacked the art of medicine at the dinner-table with sufficient rashness and sufficient pertinacity to put even Mr. Candy out of temper for the moment. I also remembered that Lady Verinder had interfered to stop the dispute, and that the little doctor and I had `made it up again,' as the children say, and had become as good friends as ever, before we shook hands that night.

`There is one thing more,' said Ezra Jennings, `which it is very important I should know. Had you any reason for feeling any special anxiety about the Diamond, at this time last year?'

`I had the strongest reasons for feeling anxiety about the Diamond. I knew it to be the object of a conspiracy; and I was warned to take measures for Miss Verinder's protection, as the possessor of the stone.'

`Was the safety of the Diamond the subject of conversation between you and any other person immediately before you retired to rest on the birthday night?'

`It was the subject of a conversation between Lady Verinder and her daughter --'

`Which took place in your hearing?'

`Yes.'