From Chapter 2:
King James himself is an unwilling witness to the popularity of tobacco. He tells us that a man could not heartily welcome his friend without at once proposing a smoke. It had become, he says, a point of good-fellowship, and he that would refuse to take a pipe among his fellows was accounted "peevish and no good company." "Yea," he continues, with rising indignation, "the mistress cannot in a more mannerly kind entertain her servant than by giving him out of her fair hand a pipe of tobacco."

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."