From Chapter 2:
A curious scene took place at Oxford in 1605 when King James visited the University. Two subjects were debated by learned dons before his Majesty, and one of them, at his own suggestion, was, "Whether the frequent use of tobacco is good for healthy men?" Among those who spoke were Doctors Ailworth, Gwyn, Gifford and Cheynell. The discussion, needless to say, being conducted in the presence of the author of the "Counterblaste to Tobacco," was not favourable to the herb. The King summed up in a speech which hopelessly begged the question while it contained plenty of strong denunciation. After his Majesty had spoken, one learned doctor, Cheynell, who is described by the recorder, Isaac Wake, the Public Orator of the University, as second to none of the doctors, had the courage to rise and, with a pipe held forth in his hand, to speak both wittily and eloquently in favour of tobacco from the medicinal point of view, praising it to the skies, says Wake, as of virtue beyond all other remedial agents. His wit pleased both the King and the whole assembly, whom it moved to laughter; but when he had finished, his Majesty made a lengthy rejoinder in which he said some curious things. He objected to the medicinal use of tobacco, and quite agreed with previous speakers that such a use must have arisen among Barbarians and Indians, who he went on to say had as much knowledge of medicine as they had of civilized customs. If, he argued, there were men whose bodies were benefited by tobacco-smoke, this did not so much redound to the credit of tobacco, as it did reflect upon the depraved condition of such men, that their bodies should have sunk to the level of those of Barbarians so as to be affected by remedies such as were effective on the bodies of Barbarians and Indians! His Majesty kindly suggested that doctors who believed in tobacco as a remedial agent should take themselves and their medicine of pollution off to join the Indians.

From Chapter Chapter 8:
Cowper then goes on to attack tobacco in lines which show how unpopular smoking at that date was with ladies, and which have since often been quoted by anti-tobacconists with grateful appreciation:

Pernicious weed! whose scent the fair annoys,
Unfriendly to society's chief joys,
Thy worst effect is banishing for hours
The sex whose presence civilizes ours;
Thou art indeed the drug a gardener wants,
To poison vermin that infest his plants,
But are we so to wit and beauty blind,
As to despise the glory of our kind,
And show the softest minds and fairest forms
As little mercy as the grubs and worms?

Notwithstanding this "satiric wipe," it is not likely that Cowper would have had much sympathy with John Wesley, who, in his detestation of what had been his father's solace at Epworth, forbade his preachers either to smoke or to take snuff.