From Chapter 2:
smoking was soon as common in the country as in London. On Wednesday, April 16, 1621, in the course of a debate in the House of Commons, Sir William Stroud, who seems to have been a worthy disciple of that tobacco-hater, King James I, moved that he "would have tobacco banished wholly out of the kingdom, and that it may not be brought in from any part, nor used amongst us"; and Sir Grey Palmes said "that if tobacco be not banished, it will overthrow 100,000 men in England, for now it is so common that he hath seen ploughmen take it as they are at plough." Perhaps this terrible picture of a ploughman smoking as he followed his lonely furrow did not impress the House so much as Sir Grey evidently thought it would; at all events, tobacco was not banished.

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.