From Chapter 3:
The number of shops where tobacco was sold in the early days of its triumph seems to have been extraordinary. Barnaby Rich, one of the most prolific parents of pamphlets in an age of prolific writers, wrote a satire on "The Honestie of this Age," which was printed in 1614. In this production Rich declares that every fellow who came into an ale-house and called for his pot, must have his pipe also, for tobacco was then a commodity as much sold in every tavern, inn and ale-house as wine, ale, or beer. He goes on to say that apothecaries' shops, grocers' shops, and chandlers' shops were (almost) never without company who from morning to night were still taking tobacco; and what a number there are besides, he adds, "that doe keepe houses, set open shoppes, that have no other trade to live by but by the selling of tobacco." Rich says he had been told that a list had been recently made of all the houses that traded in tobacco in and near about London, and that if a man might believe what was confidently reported, there were found to be upwards of 7000 houses that lived by that trade; but he could not say whether the apothecaries', grocers' and chandlers' shops, where tobacco was also sold, were included in that number. He proceeds to calculate what the annual expenditure on smoke must be. The number of 7000 seems very large and is perhaps exaggerated. Round numbers are apt to be over rather than under the mark.

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."