From Chapter 4:
Gardiner evidently follows this account, for his version of the story is: "Newcastle strolled towards his coach to solace himself with a pipe. Before he had time to take a whiff, the battle had begun." The incident was made the subject of a picture by Ernest Crofts, A.R.A., which was exhibited at the Royal Academy in 1888. It shows the Duke leaning out of his carriage window, with his pipe in his hand.

From Chapter 7:
In Townley's well-known two-act farce "High Life Below Stairs," 1759, the servants take their masters' and mistresses' titles and ape their ways. The menservants—the Dukes and Sir Harrys—offer one another snuff. "Taste this snuff, Sir Harry," says the "Duke." "'Tis good rappee," replies "Sir Harry." "Right Strasburgh, I assure you, and of my own importing," says the knowing ducal valet. "The city people adulterate it so confoundedly," he continues, "that I always import my own snuff;" and in similar vein he goes on in imitation of his master, the genuine Duke. These servants copy the talk and style (with a difference) of their employers; but smoking is never mentioned. The real Dukes and Sir Harrys took snuff with a grace, but they did not do anything so low as to smoke, and their menservants faithfully aped their preferences and their aversions.