From Chapter 2:
When Robert, Earl of Essex, and Henry, Earl of Southampton, were tried for high treason in Westminster Hall on February 19, 1600-1, the members of the House of Lords, who with the Judges formed the Court, if we may believe the French Ambassador of the time, behaved in a remarkable and unseemly manner. In a letter to Monsieur de Rohan, the Ambassador declared that while the Earls and the Counsel were pleading, their lordships guzzled and smoked; and that when they gave their votes condemning the two Earls, they were stupid with eating and "yvres de tabac"—drunk with smoking. This was probably quite untrue as a representation of what actually took place; but it would hardly have been written had smoking not been a common practice among noble lords.

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.