From Chapter 2:
Queen Elizabeth's Secretary of State, Sir Robert Cecil, would appear to have been a smoker. In a letter addressed to him, John Watts, an alderman of London, wrote: "According to your request, I have sent the greatest part of my store of tobaca by the bearer, wishing that the same may be to your good liking. But this tobaca I have had this six months, which was such as my son brought home, but since that time I have had none. At this period there is none that is good to be had for money. Wishing you to make store thereof, for I do not know where to have the like, I have sent you of two sorts. Mincing Lane, 12 Dec. 1600."

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."