From Chapter 1:
"'It requires no effort of the fancy to picture these three men [Shakespeare, Bacon and Raleigh] as lounging in a window of Durham House, puffing the new Indian weed from silver bowls, discussing the highest themes in poetry and science, while gazing on the flower-beds and the river, the darting barges of dame and cavalier, and the distant pavilions of Paris garden and the Globe.'" This is a pure "effort of the fancy" so far as Bacon and Shakespeare are concerned. Shakespeare's absolute silence about tobacco forbids us to assume that he smoked; but of Raleigh the picture may be true enough. The house had, as Aubrey tells us, "a little turret that looked into and over the Thames, and had the prospect which is as pleasant perhaps as any in the world"; and it would be strange indeed if the owner of the noble house did not often smoke a contemplative pipe in the window of that pleasant turret.

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.