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 5:
When excavations were in progress early in 1901, preparatory to the construction of Kingsway and Aldwych, they included the removal of bodies from the burying-grounds of St. Clement Danes and St. Mary-le-Strand; and among the bones were found a couple of the curious tobacco-pipes called "plague-pipes," because they are supposed to have been used as a protection against infection by those whose office it was to bury the dead. These pipes have been dug up from time to time in numbers so large that one antiquary, Mr. H. Syer Cuming, has ventured to infer that "almost every person who ventured from home invoked the protection of tobacco."