From Chapter 1:
It may further be added that though the use of tobacco was known and practised on the continent of Europe for some time before smoking became common in England—it was taken to Spain from Mexico by a physician about 1560, and Jean Nicot about the same time sent tobacco seeds to France—yet such use was exclusively for medicinal purposes. The smoking of tobacco in England seems from the first to have been much more a matter of pleasure than of hygiene.

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."