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 8:
In the whole sixteen volumes of Walpole's correspondence, as so admirably edited by Mrs. Toynbee, there is scarcely a mention of tobacco; and the same may be said of other collections of letters of the same period—the Selwyn letters, the Delany correspondence, and so on. Neither Walpole nor any member of the world in which he lived would appear to have smoked. In Miss Burney's "Evelina," 1778, from the beginning to the end of the book there is no mention whatever of tobacco or of smoking. Apparently the vulgar Branghtons were not vulgar enough to smoke. Such use of tobacco was considered low, and was confined to the classes of society indicated in the preceding chapter. One of the characters in Macklin's "Love à la Mode," 1760, is described as "dull, dull as an alderman, after six pounds of turtle, four bottles of port, and twelve pipes of tobacco."