How we cite our quotes: Collins doesn't use traditional chapters in The Moonstone, so the citations are a little trickier than in other Victorian novels. Citations follow this format: (Period.Narrative.Chapter.Paragraph).
Quote #4
The one effectual palliative in my case, is—opium. To that all-potent and all-merciful drug, I am indebted for a respite of many years from my sentence of death. But even the virtues of opium have their limit. (2.3.9.78)
Ezra Jennings takes opium to numb the pain caused by his illness. He's never specific about what his illness is, only that it's terminal, and he takes opium in order to live long enough to save money for the girl that he wanted to marry back before his reputation was ruined.
Quote #5
'Stop!' he said. 'You have suggested more to me than you suppose. Have you ever been accustomed to the use of opium?' (2.3.9.83)
Franklin Blake has been describing the disappearance of the Moonstone and his own apparent involvement in its disappearance. His description makes Ezra Jennings leap immediately to the idea that he might have taken it while under the influence of opium.
Quote #6
'This is a marked day in your life, and in mine,' he said, gravely. 'I am absolutely certain, Mr Blake, of one thing—I have got what Mr Candy wanted to say to you this morning, in the notes that I took at my patient's bedside. Wait! that is not all. I am firmly persuaded that I can prove you to have been unconscious of what you were about, when you entered the room and took the Diamond.' (2.3.9.92)
Ezra Jennings is so convinced that Franklin Blake might have taken the Diamond while under the influence of opium that he tells him that he can "prove" it.