From Chapter 2:
A curious feature of tobacco-manners among fashionable smokers of the period was the practice of passing a pipe from one to another, after the fashion of the "loving cup." There is a scene in "Greene's Tu Quoque," 1614, laid in a fashionable ordinary, where the London gallants meet as usual, and one says to a companion who is smoking: "Please you to impart your smoke?" "Very willingly, sir," says the smoker. Number two takes a whiff or two and courteously says: "In good faith, a pipe of excellent vapour!" The owner of the pipe then explains that it is "the best the house yields," whereupon the other immediately depreciates it, saying affectedly: "Had you it in the house? I thought it had been your own: 'tis not so good now as I took it for!" Another writer of this time speaks of one pipe of tobacco sufficing "three or four men at once."

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.