From Chapter 3:
It is pretty clear that not a few of the druggists who sold tobacco were great rascals. Ben Jonson has let us into some of their secrets of adulteration—the treatment of the leaf with oil and the lees of sack, the increase of its weight by other artificial additions to its moisture, washing it in muscadel and grains, keeping it in greased leather and oiled rags buried in gravel under ground, and by like devices. Other writers speak of black spice, galanga, aqua vitæ, Spanish wine, aniseeds and other things as being used for purposes of adulteration.

From Chapter 6:
Sir Roger de Coverley, as a typical country squire, was naturally a smoker. He presented his friend the Spectator, the silent gentleman, with a tobacco-stopper made by Will Wimble, telling him that Will had been busy all the early part of the winter in turning great quantities of them, and had made a present of one to every gentleman in the county who had good principles and smoked. When Sir Roger was driving in a hackney-coach he called upon the coachman to stop, and when the man came to the window asked him if he smoked. While Sir Roger's companion was wondering "what this would end in," the knight bid his Jehu to "stop by the way at any good Tobacconist's, and take in a Roll of their best Virginia." And when he visited Squire's near Gray's Inn Gate, his first act was to call for a clean pipe, a paper of tobacco, a dish of coffee, a newspaper and a wax candle; and all the boys in the coffee-room ran to serve him. The wax candle was of course a convenience in matchless days for pipe-lighting. The "paper of tobacco" was the equivalent of what is now vulgarly called a "screw" of tobacco.