From Chapter 3:
Sometimes coltsfoot was mixed with tobacco. Ursula, the pig-woman and refreshment-booth keeper in Bartholomew Fair, in Ben Jonson's play of that name, says to her assistant: "Threepence a pipe-full I will have made, of all my whole half-pound of tobacco and a quarter of a pound of coltsfoot mixt with it too to eke it out."

From Chapter 8:
A famous crony of Parr's, the learned Porson, was another devotee of tobacco. In November 1789 Parr wrote to Dr. Burney: "The books may be consulted, and Porson shall do it, and he will do it. I know his price when he bargains with me; two bottles instead of one, six pipes instead of two, burgundy instead of claret, liberty to sit till five in the morning instead of sneaking into bed at one: these are his terms:" and these few lines, it may be added, give a graphic picture of Porson. According to Maltby, Porson once remarked that when smoking began to go out of fashion, learning began to go out of fashion also—which shows what nonsense a learned man could talk.