From Chapter 2:
Hentzner, the German traveller, who visited London in 1598, speaks of smoking being customary among the audience at plays, who were also supplied with "fruits, such as apples, pears and nuts, according to the season, carried about to be sold, as well as ale and wine." He was struck with the universal prevalence of the tobacco-habit. Not only at plays, but "everywhere else," he says, the "English are constantly smoking tobacco," and then he proceeds to describe how they did it: "They have pipes on purpose made of clay, into the further end of which they put the herb, so dry that it may be rubbed into powder; and putting fire to it, they draw the smoak into their mouths, which they puff out again through their nostrils, like funnels, along with it plenty of phlegm and defluxions from the head." This suggests that the unpleasant and quite unnecessary habit of spitting was common with these early smokers, a suggestion which is amply supported by other contemporary evidence.

From Chapter 8:
More than one writer of recent days has absurdly misrepresented Johnson as a smoker. The author of a book on tobacco published a few years ago wrote—"Dr. Johnson smoked like a furnace"—a grotesquely untrue statement—and "all his friends, Goldsmith, Reynolds, Garrick, were his companions in tobacco-worship." Reynolds, we know—

When they talk'd of their Raphaels, Corregios, and stuff,
He shifted his trumpet, and only took snuff.

Johnson and all his company took snuff, as every one in the fashionable world, and a great many others outside that charmed circle, did; but Johnson did not smoke, and I doubt whether any of the others did.