From Chapter 1:
It may further be added that though the use of tobacco was known and practised on the continent of Europe for some time before smoking became common in England—it was taken to Spain from Mexico by a physician about 1560, and Jean Nicot about the same time sent tobacco seeds to France—yet such use was exclusively for medicinal purposes. The smoking of tobacco in England seems from the first to have been much more a matter of pleasure than of hygiene.

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.