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:
There is ample evidence, apart from Johnson's dictum, that in the latter part of the eighteenth century smoking had "gone out." In Mrs. Climenson's "Passages from the Diaries of Mrs. Lybbe Powys," we hear of a bundle of papers at Hardwick House, near Whitchurch, Oxon, which bears the unvarnished title "Dick's Debts." This Dick was a Captain Richard Powys who had a commission in the Guards, and died at the early age of twenty-six in the year 1768. This list of debts, it appears, gives "the most complete catalogue of the expenses of a dandy of the Court of George II, consisting chiefly of swords, buckles, lace, Valenciennes and point d'Espagne, gold and amber-headed canes, tavern bills and chair hire." But in all the ample detail of Captain Powys's list of extravagances there is nothing directly or indirectly relating to smoking. The beaux of the time did not smoke.