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 5:
The belief in the prophylactic power of tobacco was, however, very generally held. When Mr. Samuel Pepys on June 7, 1665, for the first time saw several houses marked with the ominous red cross, and the words "Lord, have mercy upon us" chalked upon the doors, he felt so ill at ease that he was obliged to buy some roll tobacco to smell and chew. There is nothing to show that Pepys even smoked, which considering his proficiency in the arts of good-fellowship, is perhaps a little surprising. Defoe, in his fictitious but graphic "Journal of the Plague Year in London," says that the sexton of one of the London parishes, who personally handled a large number of the victims, never had the distemper at all, but lived about twenty years after it, and was sexton of the parish to the time of his death. This man, according to Defoe, "never used any preservative against the infection other than holding garlic and rue in his mouth, and smoking tobacco."