From Chapter 2:
The properly accomplished gallant not only professed to be curiously learned in pipes and tobacco, but his knowledge of prices and their fluctuations, of the apothecaries' and other shops where the herb was sold, and of the latest and most fashionable ways of inhaling and exhaling the smoke, was, like Mr. Weller's knowledge of London, "extensive and peculiar." It was knowledge of this kind that gained for a gallant reputation and respect by no means to be acquired by mere scholarship and learning.

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.