From Chapter 1:
In this "Report" Hariot says of the tobacco plant: "There is an herbe which is sowed a part by itselfe and is called by the inhabitants Vppówoc: In the West Indies it hath divers names, according to the severall places and countries where it groweth and is used: The Spaniardes generally call it Tobacco. The leaves thereof being dried and brought into powder: they use to take the fume or smoke thereof by sucking it through pipes made of claie into their stomacke and heade: from whence it purgeth superfluous fleame and other grosse humors, openeth all the pores and passages of the body: by which meanes the use thereof, not only preserveth the body from obstructions: but if also any be, so that they have not beane of too long continuance, in short time breaketh them: wherby their bodies are notably preserved in health, and know not many greevous diseases wherewithall wee in England are oftentimes afflicted."

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."