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 7:
At Oxford in early Georgian days a profound calm—so far as study was concerned—appears to have prevailed. Little work was done, but much tobacco was smoked. In 1733 a satire was published, violently attacking the Fellows of various colleges. According to this satirist the occupation of the Magdalen Fellow was to
drink, look big,
Smoke much, think little, curse the freeborn Whig—

from which it may not unreasonably be surmised that the author was a Tory; and however little enthusiasm there may have been at Oxford in those days for learning and study, there was plenty of life in political animosities.

Another witness to the dons' love of tobacco is Thomas Warton. In his "Progress of Discontent," written in 1746, he plaintively sang:

Return, ye days when endless pleasure
I found in reading or in leisure!
When calm around the Common Room
I puff'd my daily pipe's perfume!
Rode for a stomach, and inspected,
At annual bottlings, corks selected:
And dined untax'd, untroubled, under
The portrait of our pious Founder!