From Chapter 3:
Trickery of another kind is revealed in a scene in Chapman's play "A Humorous Day's Mirth," 1599. A customer at an ordinary says: "Hark you, my host, have you a pipe of good tobacco?" "The best in the town," says mine host, after the manner of his class. "Boy, dry a leaf." Quietly the boy tells him, "There's none in the house, sir," to which the worthy host replies sotto voce, "Dry a dock leaf." But the diner's potations must have been powerful if they had left him unable to distinguish between the taste of tobacco and that of dried dock-leaf.

From Chapter 8:
Cowper's aversion from tobacco could not have been very strong, for he encouraged his friend to smoke in the famous Summer House at Olney, which was the poet's outdoor study. Bull smoked Orinoco tobacco, which he carried in one of the tobacco-boxes, which in those days were much more commonly used than pouches, and this box on one occasion he accidentally left behind him at Olney. Cowper returned it to him with the well-known rhymed epistle dated June 22, 1782, and beginning:

If reading verse be your delight,
'Tis mine as much, or more, to write;
But what we would, so weak is man,
Lies oft remote from what we can.